JP4110661B2 - Refrigeration air conditioner - Google Patents

Description

【００５７】
例えば、表１の合計運転容量が３ＨＰのとき、圧縮機１ａでは短周期の時間配分として６ＨＰの最大容量運転を２．５秒、２ＨＰの最小容量運転を７．５秒とすると、短周期の平均容量は、（６×２．５＋２×７．５）／１０＝３となり、圧縮機１ｂは停止しているので、合計の運転容量として３ＨＰが得られる。また、合計運転容量が９ＨＰのとき、圧縮機１ａでは短周期の時間配分として６ＨＰの最大容量運転を７．５秒、２ＨＰの最小容量運転を２．５秒とすると、短周期の平均容量は、（６×７．５＋２×２．５）／１０＝５となり、圧縮機１ｂ（４ＨＰの運転容量）は運転しているので、合計の運転容量として９ＨＰが得られる。このように、最大容量運転と最小容量運転の短周期の時間配分を変化させて短周期での平均容量を変化させ、圧縮機１ａ、１ｂの運転容量の合計を連続的に任意に変化させることができる。ここで、短周期で所定の時間配分で段階的に容量を変化させる運転を、時間制御運転と称する。
【００５８】
なお表１での高圧側電磁弁１０ａと低圧側電磁弁１０ｂの運転では図４に示すように、必ずどちらか一方が開、どちらか一方が閉となるように開閉を制御する。図５は圧縮機１ａ、１ｂの運転容量の変化を示し、必要運転容量［ＨＰ］に対する圧縮機運転容量［ＨＰ］を示すグラフであり、表１によって実現される圧縮機の合計運転容量の変化を図示したものである。表１のような圧縮機の容量で運転することで、本実施の形態では複数の圧縮機１ａ、１ｂの全体運転容量を２ＨＰ〜１０ＨＰまで連続的に運転容量を変化させることができる。
【００５９】
この場合の運転容量の短周期での変動幅を見ると、運転容量が６ＨＰ〜１０ＨＰでは、圧縮機１ａが最大容量で運転している場合には圧縮機１ａ、１ｂ合計で１０ＨＰの容量で運転し、圧縮機１ａが最小容量で運転している場合には圧縮機１ａ、１ｂ合計で６ＨＰの容量で運転することになる。即ち運転容量は短周期に１０ＨＰと６ＨＰで変動する。
従って２ＨＰ〜１０ＨＰまで連続的な運転容量を実現する空調装置であっても、従来技術にあるように圧縮機１台で運転する場合には運転容量は短周期に１０ＨＰと２ＨＰで変動するのに対し、本実施の形態では運転容量の変動幅を小さくできる。
運転容量の変動幅を小さくできると、冷凍サイクル上に発生する圧力脈動は小さくなり、熱交換器での熱交換量の変動幅、熱交換器に空気熱交換器を用いた場合の吹出空気温度の変動幅など、冷凍空調装置における冷凍能力や空調能力の変動を小さくでき、冷凍空調装置運転の際の快適性を確保できる。
【００６０】
また運転容量が２ＨＰ〜６ＨＰでは、運転容量は短周期に２ＨＰと６ＨＰで変動する。この場合も従来技術にあるように圧縮機１台で運転する場合には運転容量は短時間に１０ＨＰと２ＨＰで変動するのに対し、本実施の形態では運転容量の変動幅を小さくできる。
この場合も運転容量の変動幅を小さくでき、冷凍サイクル上に発生する圧力脈動幅、熱交換器での熱交換量の変動幅、熱交換器に空気熱交換器を用いた場合の吹出空気温度の変動幅を小さくでき、冷凍空調装置における冷凍能力や空調能力の変動を小さくできるので、冷凍空調装置運転の際の快適性を確保できる。
【００６１】
以上のように、本実施の形態では、段階的な容量で運転可能な圧縮機１ａと一定容量で運転する圧縮機１ｂとを備え、インバータを用いずに運転することで、インバータを用いることによる高調波の悪影響がなく、且つ、圧縮機１ａの運転容量を短周期で切り換えて連続的な運転容量を実現するときの容量変動幅を小さくして、これにより生じる圧力変動などの冷凍サイクル上の変動幅を抑制できる。このため、吹出空気温度の変動など冷凍能力や空調能力の変動を小さくでき、運転の際の快適性を確保できる冷凍空調装置を得ることができる。
【００６２】
なお表１では運転容量の切り換えの周期を１０秒間隔（最大容量の運転時間と最小容量の運転時間を合わせた時間）で行っているが、この周期は、圧力変動幅や、熱交換器に空気熱交換器を用いた場合の吹出空気温度の変動幅などによって決められる。例えば冷凍空調装置運転の際の快適性を確保するために熱交換器に空気熱交換器を用いた場合の吹出空気温度の変動幅を１℃程度に押さえようとすると、冷凍サイクルの圧力変動幅は高圧で２ｋｇｆ／ｃｍ² 、低圧で１ｋｇｆ／ｃｍ² 程度以下に設定する必要がある。この圧力変動幅に押さえるための運転容量の切り換え間隔は、その短周期内の段階的な運転容量変動幅、即ち最大容量と最小容量の差によって変化するが、一般的な冷凍サイクルでは概ね数秒から数１０秒間隔に設定される。
【００６３】
また上記では、圧縮機１ａとして、最大容量と最小容量の２段階の容量で運転可能な圧縮機としたが、２段階に限るものではなく、もっと多くの段階の容量で運転可能な圧縮機を用いれば、運転パターンが多くなって運転制御は煩雑になるが、短周期の時間配分で切り換える運転容量の差は小さくでき、冷凍サイクルの圧力変動をさらに小さくでき冷凍空調装置運転の際の快適性は高まる。図２、図３に示したスクロール圧縮機で、２以上の複数段階の運転容量を得るには、例えば最小容量を実現するバイパス穴２３ａよりも外側の圧縮室２２に低圧配管と連通する他のバイパス穴を設け、この穴を閉塞、開放することによって圧縮室２２の冷媒ガスの量を変化させれば実現できる。
【００６４】
また上記では、段階的な容量で運転可能な圧縮機１台と一定容量の圧縮機１台の組み合わせとして説明したが、段階的な容量で運転可能な圧縮機１台と一定容量の圧縮機を複数台組み合わせた場合、段階的な容量で運転可能な圧縮機複数台と一定容量の圧縮機を１台組み合わせた場合、段階的な容量で運転可能な圧縮機複数台と一定容量の圧縮機を複数台組み合わせた場合、いずれの場合においても同様の効果を得ることができる。
また、冷凍サイクルの圧力変動を小さくできるという効果から言えば、段階的な容量で運転可能な圧縮機の容量段階数を多く備えたほうが、少ない容量段階数よりも短周期で切り換える容量差を小さくできるため、効果的である。また、圧縮機の台数が多いほうが、台数が少ないよりも短周期で切り換える容量差を小さくできるため、効果的である。
【００６５】
実施の形態２．
以下、本発明の実施の形態２による冷凍空調装置として例えば室内の空調を行う装置について説明する。図６は本実施の形態による冷凍空調装置の構成を示す冷媒回路図である。図において、１ｃは段階的な容量で運転可能な圧縮機で、例えばバイパス容量制御手段を設けたスクロール圧縮機、１０ｃ、１０ｄはスクロール圧縮機１ｃの運転容量を制御するための制御弁で、１０ｃは例えば吐出配管２ｂからの配管１１ｂに設けられた高圧側電磁弁、１０ｄは例えば吸入配管３ｂからの配管１２ｂに設けられた低圧側電磁弁である。電磁弁１０ｃ、１０ｄからの配管１３ｂ、１４ｂは結合されて、スクロール圧縮機１ｃの容量制御用配管１５ｂを介してスクロール圧縮機１ｃに接続されている。
また本実施の形態での冷凍空調装置の最大運転容量は１０ＨＰであり、圧縮機１ａは最大容量６ＨＰと最小容量４ＨＰの段階的な容量切り換えが可能な圧縮機、圧縮機１ｃは最大容量４ＨＰと最小容量２ＨＰの段階的な容量切り換えが可能な圧縮機である。即ち、段階的な容量で運転可能な圧縮機を２台設け、最大容量６ＨＰの圧縮機１ａと最大容量４ＨＰの圧縮機１ｃとで、最大容量１０ＨＰの冷凍空調装置を構成している。
なお、図６の他の要素、並びに冷媒の流れ、および図６における圧縮機の容量の切り換え方法は実施の形態１と同じであるので説明を省略する。
【００６６】
本実施の形態では実施の形態１と同様の方法で、圧縮機の必要運転容量は、冷凍空調装置の運転状態、外気温度、室内空気温度、室内空気温度の目標値、室内熱交換器８ａ、８ｂの運転容量などによって決定される。そして、決定された圧縮機の必要運転容量に応じて、圧縮機１ａ、１ｃの高圧側電磁弁１０ａ、１０ｃと低圧側電磁弁１０ｂ、１０ｄの短周期での開閉、および圧縮機１ａ、１ｃの運転、停止を組み合わせて容量制御を実施する。表２は、合計運転容量２ＨＰ〜１０ＨＰを得るときの圧縮機１ａの高圧側電磁弁１０ａと低圧側電磁弁１０ｂの開閉、運転、停止、および圧縮機１ｃの高圧側電磁弁１０ｃと低圧側電磁弁１０ｄの開閉、運転、停止を示している。この圧縮機１ａ、１ｃのそれぞれの容量制御でも、実施の形態１と同様、例えば１０秒を１周期とし、高圧側電磁弁１０ａ、１０ｃを開（低圧側電磁弁１０ｂ、１０ｄを閉）とした時の最大容量運転（６ＨＰ、４ＨＰ）と低圧側電磁弁１０ｂ、１０ｄを開（高圧側電磁弁１０ａ、１０ｃを閉）とした時の最小容量運転（４ＨＰ、２ＨＰ）の２段階で１０秒という短周期の時間配分を振り分けている。この時間配分を変化させて短周期での平均容量を変化させることにより、圧縮機１ａ、１ｃの運転容量の合計を連続的に任意に変化させることができる。
【００６７】
【表２】

【００６８】
なお表２での高圧側電磁弁１０ａ、１０ｃと低圧側電磁弁１０ｂ、１０ｄの運転では図４に示すように、必ずどちらか一方が開、どちらか一方が閉となるように開閉を制御する。図７は、圧縮機１ａ、１ｃの運転容量の変化を示し、必要運転容量［ＨＰ］に対する圧縮機運転容量［ＨＰ］を示すグラフであり、表２によって実現される圧縮機の合計運転容量の変化を図示したものである。
【００６９】
この場合の運転容量の短時間での変動幅を見ると、運転容量が８ＨＰ〜１０ＨＰでは、圧縮機１ａが最大容量で運転している場合には圧縮機１ａ、１ｃ合計で１０ＨＰの容量で運転し、圧縮機１ａが最小容量で運転している場合には圧縮機１ａ、１ｃ合計で８ＨＰの容量で運転することになる。即ち運転容量は短周期に１０ＨＰと８ＨＰで変動する。
他の運転容量においても、運転容量が６ＨＰ〜８ＨＰの場合は、運転容量は短時間に８ＨＰと６ＨＰで変動、運転容量が４ＨＰ〜６ＨＰの場合は、運転容量は短時間に４ＨＰと６ＨＰで変動、運転容量が２ＨＰ〜４ＨＰの場合は、運転容量は短時間に２ＨＰと４ＨＰで変動する。
従って、複数の圧縮機１ａ、１ｃの全体として運転容量を２ＨＰ〜１０ＨＰまで連続的に実現でき、この実現する際、インバータを使用せず、且つ、従来技術にあるように圧縮機１台で運転する場合には運転容量は短周期に１０ＨＰと２ＨＰで変動するのに対し、運転容量の変動幅を小さくできる。また実施の形態１に比べても運転容量の変動幅の小さい運転を行うことができる。
【００７０】
以上のように、本実施の形態では、２台の段階的な容量で運転可能な圧縮機１ａ、１ｃを備え、インバータを用いずに運転することで、インバータを用いることによる高調波の悪影響がなく、且つ、圧縮機１ａ、１ｃの運転容量を短周期で切り換えて連続的な運転容量を実現するときの容量変動幅を小さくして、これにより生じる圧力変動などの冷凍サイクル上の変動幅を抑制できる。このため、吹出空気温度の変動など冷凍能力や空調能力の変動を小さくでき、運転の際の快適性を確保できる冷凍空調装置を得ることができる。
【００７１】
ここで、段階的な容量で運転可能な２台の圧縮機１ａ、１ｃによって２ＨＰ〜１０ＨＰで連続的に運転容量を変化させる組み合わせは、表２および図７に示した方法だけではない。表２での制御では、図７からもわかるように運転容量が６ＨＰ〜１０ＨＰの範囲において、８ＨＰ〜１０ＨＰでは圧縮機１ａの方の時間制御運転を行い、６ＨＰ〜８ＨＰでは圧縮機１ｃの方の時間制御運転を行っているが、図８に示すように、８ＨＰ〜１０ＨＰの範囲では圧縮機１ｃの方の時間制御運転を行い、６ＨＰ〜８ＨＰの範囲で圧縮機１ａの方の時間制御運転を行ってもよい。
【００７２】
また、図９に示すように、６ＨＰ〜１０ＨＰの範囲で圧縮機１ａ、１ｃともに時間制御運転を行っていくという容量制御方法を行ってもよい。このときの圧縮機１ａ、１ｃの容量制御の様子を表３に示す。複数の段階的な容量で運転可能な圧縮機を複数備えている場合、各圧縮機において、短周期の間ずっとその段階のうちの最小容量で運転することを避けて制御している。このため、運転容量が、圧縮機１ａ、１ｂの小さい方の容量の合計（６ＨＰ）よりも大きく、大きい方の容量の合計（１０ＨＰ）よりも小さい場合には、２台の圧縮機１ａ、１ｃで共に時間制御運転を行っている。また合計運転容量が４ＨＰでは、圧縮機１ａで最小容量で運転するか、圧縮機１ｂで最大容量で運転するかの２通りがあるが、圧縮機１ａでの最小容量運転を避け、圧縮機１ｂでの最大容量運転を行う。
【００７３】
【表３】

【００７４】
バイパス容量制御手段を設けた圧縮機では、最小容量運転を行う際にはバイパスの影響により、最大容量運転を行う場合に比べ圧縮機の吐出温度が上昇する。従って、図７、図８に示したように、運転容量８ＨＰのときのように１台の圧縮機１ａで最小容量運転、別の１台の圧縮機１ｃでは最大容量運転となった場合、最小容量運転の圧縮機１ａの吐出温度が最大容量運転の圧縮機１ｃに比べて上昇する。この場合圧縮機の運転保護として吐出温度を検知し、吐出温度がある温度以上に上昇した場合圧縮機を停止させる制御を行った場合、最小容量運転の圧縮機１ａの吐出温度のみが保護によって停止する状況が発生し、安定した運転を実施できない。
そこで、図９および表３に示すように６ＨＰ〜１０ＨＰからの範囲で圧縮機１ａ、１ｂともに時間制御運転を行い、両圧縮機の吐出温度を同程度の温度にすることで、圧縮機の運転保護を吐出温度を検知して実行した場合、運転保護を必要とするような運転状況となった場合には、両圧縮機を同時に停止でき、そうでない場合は両圧縮機の運転を継続して行えるので、安定した運転を実施できる。
ただし、ある圧縮機を複数の段階のうちの最小容量で運転しなければ運転容量値が得られない場合、例えば表３の合計運転容量が２ＨＰのような場合には、この限りではない。
【００７５】
このように、段階的な容量で運転可能な圧縮機を複数備えた冷凍空調装置の場合、複数の圧縮機全体の運転容量を段階的な容量で運転可能な圧縮機に分担して運転する際、圧縮機に分担する運転容量が、その圧縮機の段階的な容量のうちの最小容量と一致するのを避けて分担することで、運転する圧縮機の吐出温度を同等にできるので、特定の圧縮機の吐出温度が上昇するのを防止できる。
なお、運転容量０ＨＰは、段階的な容量で運転可能な圧縮機１ａの運転容量段階としては可能であるが、０ＨＰのときには運転しないので吐出温度の上昇は生じないため、前記のような問題は起こらない。このため、ここでいう最小容量とは見なさない。即ち、この最小容量とは、０ＨＰより大きい段階的な容量のうちで最小の容量のことである。
また段階的な容量で運転可能な圧縮機の最小容量をなるべく避けるように運転するのに限らず、ある運転容量を実現するとき、複数の圧縮機にその運転容量を分担させる組み合わせが複数存在するとき、それらの組み合わせの中で運転する圧縮機の吐出温度にばらつきの少なくできる組み合わせを選ぶとよい。圧縮機のそれぞれの容量段階の最小容量の合計値よりも大きく、最大容量の合計値よりも小さい運転容量で運転を行う場合には、複数の圧縮機を時間制御運転させるようにすると、特定の圧縮機から吐出される冷媒の温度が上昇するのを防止でき、安定した運転を行うことができる。
【００７６】
また、図１０、図１１は、本実施の形態に係わる各圧縮機の運転容量の時間変化を示す説明図で、横方向に時間、縦方向に圧縮機運転容量を示している。図９のような運転容量制御を行った場合の時間制御運転で、図１０に示すように、圧縮機１ａ、１ｃの大きい容量での運転と小さい容量での運転を同じタイミングで運転すると、運転容量は短周期に（圧縮機１ａの大きい容量＋圧縮機１ｃの大きい容量＝１０ＨＰ）と（圧縮機１ａの小さい容量＋圧縮機１ｃの小さい容量＝６ＨＰ）とで変動する。これに対し、図１１に示すように圧縮機１ａ、１ｃの大きい容量での運転と小さい容量での運転を反対のタイミング（逆位相）で運転すると、運転容量の短周期での変動は、（圧縮機１ａの大きい容量＋圧縮機１ｃの小さい容量＝８ＨＰ）と（圧縮機１ａの小さい容量＋圧縮機１ｃの大きい容量＝８ＨＰ）となり、全体としてほとんど容量の変動のない状況で運転可能である。従って、圧縮機１ａ、１ｃともに容量制御を行って時間制御運転をする場合には、できるだけ圧縮機１ａ、１ｃの大きい容量と小さい容量での運転が反対のタイミング（逆位相）で運転する時間を長くするように運転することで、圧縮機１ａ、１ｃの運転容量合計値の変動幅を小さくすることができ、冷凍空調装置運転の際の快適性を確保できる。
【００７７】
上記では２台の圧縮機で時間制御運転を行う場合であり、段階的な容量の運転を反対のタイミングで行っているが、３台以上で時間制御運転を行う場合には、互いに反対のタイミングで段階的な容量の運転とすることは困難となる。この場合には、短周期内における各圧縮機の運転容量の合計の時間的な変動が小さくなるように、各圧縮機の短周期容量運転の変化を組み合わせるとよい。例えば、短周期内で圧縮機Ａが４ＨＰと２ＨＰ、圧縮機Ｂが４ＨＰと２ＨＰ、圧縮機Ｃが３ＨＰと２ＨＰの容量変化運転を行っている場合、時間配分の一方では圧縮機Ａで４ＨＰ、圧縮機Ｂで２ＨＰ、圧縮機Ｃで３ＨＰの容量で運転を行うと運転容量の合計は９ＨＰとなり、時間配分の他方では圧縮機Ａで２ＨＰ、圧縮機Ｂで４ＨＰ、圧縮機Ｃで２ＨＰの容量で運転を行うと運転容量の合計は８ＨＰとなり、短周期での容量変動は９ＨＰ−８ＨＰ＝１ＨＰと小さく押さえるように運転できる。もちろん各圧縮機で時間配分が異なっており、２台の時と同様、このタイミングで運転する時間がなるべく長くなるように運転すれば容量の変動をできるだけ小さくすることができる。
【００７８】
もちろん、上記の具体例のように短周期内における各圧縮機の運転容量の合計の時間的な変動を最小にすると、圧力変動が小さくなるので好ましいが、最小にすることに限るものではなく、各圧縮機の運転容量の合計の時間的な変動がすこしでも小さくなるように組み合せるとよい。
即ち、複数の圧縮機をそれぞれ時間制御運転する場合に、各圧縮機の運転容量の合計の短周期内での時間的な変動が一番大きい組み合わせは、その短周期内で全圧縮機が大きい方の容量で運転を行い、全圧縮機が同時に小さい方の容量に切り換えたときである。このとき短周期での容量の変化は大きい方の容量の合計と小さい方の容量の合計の差となる。そこで、本実施の形態では、各圧縮機の運転容量の合計の短周期内での時間的な変動が、その短周期に運転する各圧縮機の大きい方の運転容量の合計と小さい方の運転容量の合計との差よりも小さくなるように、各圧縮機の短周期の時間配分とその各時間の運転容量を組み合せて運転する。このように運転すれば、運転容量の時間的な変動幅がある程度小さくなるので、時間制御運転による圧力変動を抑制し、冷凍空調装置運転の際の快適性を確保できる。
【００７９】
また、本実施の形態のように段階的な容量で運転可能な圧縮機１ａ、１ｃを２台備えている場合には、短周期のうちで、一方の圧縮機がその段階の大きい方の容量の運転を行なう時間の少なくとも一部の時間に、他方の圧縮機がその段階の小さい方の容量の運転を行なうと共に、他方の圧縮機がその段階の大きい方の容量の運転を行なう時間の少なくとも一部の時間に、一方の圧縮機がその段階の小さい方の容量の運転を行なうように運転すると、２台の圧縮機１ａ、１ｃ共に大きい容量で運転するという状態が、短周期内で長時間重なるよりは、圧力変動を小さくできる。
【００８０】
この短周期の時間配分の様子を図１２に示す。図１０では、圧縮機１ａ、１ｃの大きい容量での運転と小さい容量での運転を同じタイミングで運転しているが、図１２では、このタイミングを時間方向にずらしている。このため、運転容量を見ると、短周期のうちのＴ１では、一方の圧縮機１ａが大きい方の容量（６ＨＰ）の運転を行なう時間の少なくとも一部の時間に、他方の圧縮機１ｃが小さい方の容量（２ＨＰ）の運転を行なっている。これと共に短周期のうちのＴ２では、他方の圧縮機１ｃが大きい方の容量（４ＨＰ）の運転を行なう時間の少なくとも一部の時間に、一方の圧縮機１ａが小さい方の容量（４ＨＰ）の運転を行なう。これにより、運転容量の変動は、８ＨＰ−１０ＨＰ−８ＨＰ−６ＨＰとなる。このように運転すれば、図１０のような運転に比べ、運転容量の時間的な変動幅がある程度小さくなるので、時間制御運転による圧力変動を抑制し、冷凍空調装置運転の際の快適性を確保できる。
【００８１】
また、本実施の形態では基本的には段階的な容量で運転可能な圧縮機を２台備えた構成の場合として説明したが、段階的な容量で運転可能な圧縮機を３台以上用いた場合においても同様の効果を得ることができる。
冷凍サイクルの圧力変動を小さくできるという効果から言えば、段階的な容量で運転可能な圧縮機の容量段階数を多く備えたほうが、少ない容量段階数よりも短周期で切り換える容量差を小さくできるため、効果的である。また、圧縮機の台数が多いほうが、台数が少ないよりも短周期で切り換える容量差を小さくできるため、効果的である。
【００８２】
なお、実施の形態１、実施の形態２では、圧縮機１ａ、１ｃをバイパス容量制御手段を設けたスクロール圧縮機として説明したが、圧縮機１ａ、１ｃとして従来技術において説明したようなロータリー圧縮機を用いても同様の効果を得ることができる。
また、モータのポールチェンジによって圧縮機の回転数を短周期で段階的に変化させてもよい。また、圧縮機１ａ、１ｃとしてレシプロ圧縮機を用い、運転する気筒の数を短周期で段階的に変化させても、上記各実施の形態と同様の効果を得ることができる。
【００８３】
参考の形態３．
以下、本発明の実施の形態３による冷凍空調装置として例えば室内の空調を行う装置について説明する。図１３は本参考の形態による冷凍空調装置の構成を示す冷媒回路図である。図において、１６は冷凍サイクルの高圧側に設けられた冷媒容器であり、１７は冷凍サイクルの低圧側に設けられた冷媒容器である。なお、図１３の他の要素、並びに冷媒の流れ、および図１３における圧縮機の容量の切り換え方法は実施の形態１と同様である。
【００８４】
本参考の形態においても段階的な容量で運転可能な圧縮機１ａを少なくとも１台備えている。さらに参考の形態１と同様、一定容量の圧縮機１ｂを少なくとも１台備え、短周期の時間配分を振り分けた各時間で圧縮機１ａを異なる段階の容量で運転する時間制御運転を行なっている。そして、短周期の時間配分を変化させることで、その平均容量を変化させ、複数の圧縮機１ａ、１ｂ全体として運転容量を任意に連続的に変化させることができる。この様に容量制御を行なうことで、高調波によって他の機器に悪影響を及ぼすインバータを用いずに、圧縮機１ａ、１ｂを連続的な容量で運転できる。
この圧縮機１ａの時間制御運転で、冷凍サイクル上に発生する圧力脈動幅、熱交換器での熱交換量の変動幅、熱交換器に空気熱交換器を用いた場合の吹出空気温度の変動などは、圧縮機１ａでの段階的な運転容量の切り換えに伴って生じるもので、圧縮機１ａに吸入または吐出される冷媒流量の変動が原因で発生する。
【００８５】
ここで、変動発生の状況をまず高圧側に注目してみる。冷凍サイクルの高圧側を１つの容器と見なして、圧縮機１ａ、１ｂから吐出された冷媒が高圧側の容器に流入すると考える。圧縮機１ａの運転容量が増加し、圧縮機１ａから吐出される冷媒流量が増加したときには、高圧側の容器に流入する冷媒流量が増加する。このとき高圧側の容器内に存在する冷媒量が増加するため、容器内の冷媒の密度も増加し、容器内の圧力は上昇する。逆に圧縮機１ａの運転容量が減少し、圧縮機１ａから吐出される冷媒流量が減少したときには、高圧側の容器に流入する冷媒流量が減少する。このとき高圧側の容器内に存在する冷媒量が減少するため、容器内の冷媒の密度も減少し、容器内の圧力は低下する。
【００８６】
低圧側の変動発生の状況も同様に捉えることができ、冷凍サイクルの低圧側を１つの容器と見なして、圧縮機１ａ、１ｂに吸入される冷媒が低圧側の容器から流出したと考える。圧縮機１ａの運転容量が増加し、圧縮機１ａに吸入される冷媒流量が増加したときには、低圧側の容器から流出する冷媒流量が増加する。このとき低圧側の容器内に存在する冷媒量が減少するため、容器内の冷媒の密度も減少し、容器内の圧力も低下する。逆に圧縮機１ａの運転容量が減少し、圧縮機１ａに吸入される冷媒流量が減少したときには、低圧側の容器から流出する冷媒流量が減少する。このとき低圧側の容器内に存在する冷媒量が増加するため、容器内の冷媒の密度も増加し、容器内の圧力は上昇する。
【００８７】
このように圧力の変動は、容器内の冷媒量の変動が容器内の冷媒の密度の変動を引き起こすことで発生する。そこで容器内の冷媒の密度は容器内の冷媒量／容器の容積で表せることに着目すると、容器内の冷媒量の変動があっても、容器の容積が大きければ、容器内の冷媒の密度の変動幅を小さくできることがわかる。
本参考の形態では上記のような現象に基づき、冷凍サイクルの高圧側の冷媒容器１６、または低圧側の冷媒容器１７、または両方を設けることで、冷凍サイクルの高圧側の容積を第１の所定容積以上とし、または低圧側の容積を第２の所定容積以上とする。
【００８８】
次に、高圧側容器１６と低圧側容器１７の容積について説明する。高圧側または低圧側の容器の容積［Ｌ］、時間制御運転での運転容量変動幅［ＨＰ］、冷凍サイクル上に発生する圧力変動幅［ｋｇ／ｃｍ² ］、時間制御運転での短周期の長さ［ｓｅｃ］の４つのパラメータにはそれぞれ互いに関係があり、例えば冷凍空調装置の設計時に低圧側または高圧側の容器の容積を決定する際には、他の３つのパラメータの値が決まれば、その容積を決定できる。ただし、高圧側の容器を構成する機器は、圧縮機吐出配管２ａ、２ｂ−高圧側容器１６−四方弁４−凝縮器（冷房運転では室外熱交換器５であり、暖房運転では室内熱交換器８ａ、８ｂ）−膨張弁７ａ、７ｂの各機器およびこれらを接続する配管である。一方低圧側の容器を構成する機器は、膨張弁７ａ、７ｂ−蒸発器（冷房運転では室内熱交換器８ａ、８ｂであり、暖房運転では室外熱交換器５）−四方弁４−低圧側容器１７−圧縮機吸入配管３ａ、３ｂの各機器およびこれらを接続する配管である。実施の形態１でも述べたが、時間制御運転での短周期の長さ［ｓｅｃ］は、圧力変動幅、熱交換器に空気熱交換器を用いた場合の吹出空気温度の変動幅などによって決められる。例えば冷凍空調装置運転の際の快適性を確保するために熱交換器に空気熱交換器を用いた場合の吹出空気温度の変動幅を１℃程度に押さえようとすると、冷凍サイクルの圧力変動幅は高圧で２ｋｇｆ／ｃｍ² 、低圧で１ｋｇｆ／ｃｍ² 程度以下に設定する必要がある。この圧力変動幅に押さえるための短周期の長さ［ｓｅｃ］は、時間制御運転での運転容量変動幅［ＨＰ］によって変化するが、一般的な冷凍サイクルでは概ね数秒から数１０秒間隔に設定される。また、時間制御運転での運転容量変動幅［ＨＰ］は、最小容量を０．３ＨＰ以上、最大容量を最小容量の２〜３倍程度とし、変動可能幅（最大容量−最小容量）の１／１０〜１倍に設定する。
また、冷凍空調装置を構成するのに最低限必要な各機器と配管の容積は予め計算または推定でき、高圧側容器１６または低圧側容器１７の容積は、上記４つのパラメータのうち他の３つのパラメータを決定することにより決定される低圧側または高圧側の容器の容積から最低限必要な各機器と配管の容積を差し引いた容積以上とすればよい。
なお、ここでは、４つのパラメータのうち容積以外の他のパラメータを決定することにより容積を決定する方法について述べたが、これに限るものではなく、４つのパラメータのうち少なくとも３つのパラメータの値を決定すれば、残りの１つを決定することができ、冷凍空調装置の設計時などに用いれば、快適性の高い装置を得るのに有効である。
【００８９】
実際に高圧側容器１６と低圧側容器１７の容積を決定する手順について説明する。図１４は、横軸に時間制御運転での短周期の長さである運転容量制御間隔を示し、縦軸に｛高圧側を構成する機器および配管の容積（Ｌ）｝／運転容量変動幅［ＨＰ］を示すグラフ、図１５は、横軸に時間制御運転での短周期の長さである運転容量制御間隔を示し、縦軸に｛低圧側を構成する機器および配管の容積（Ｌ）｝／運転容量変動幅［ＨＰ］を示すグラフである。そしてグラフ上の曲線は、図１４ではそれぞれ冷凍サイクルの圧力変動幅が１ｋｇ／ｃｍ² 、２ｋｇ／ｃｍ² 、３ｋｇ／ｃｍ² を表し、図１５ではそれぞれ冷凍サイクルの圧力変動幅が０．５ｋｇ／ｃｍ² 、１ｋｇ／ｃｍ² 、２ｋｇ／ｃｍ² を表している。
【００９０】
図１４、図１５の関係は、シュミレーションによって得られたものである。この関係に基づいて、運転容量制御間隔と圧力変動幅を一定値以下にするために必要な低圧側または高圧側の容器の容積を求める方法について説明する。
前述のように冷凍空調装置運転の際の快適性を確保するため、熱交換器に空気熱交換器を用いたときの吹出空気温度の変動幅を１℃程度に押さえようとすると、冷凍サイクルの圧力変動幅は高圧で２ｋｇｆ／ｃｍ² 、低圧で１ｋｇｆ／ｃｍ² 程度以下に設定する必要がある。
【００９１】
そこで高圧の圧力変動幅を２ｋｇｆ／ｃｍ² に押さえる場合には、運転容量制御間隔を１０秒で運転すると図１４より、高圧側容積［Ｌ］／運転容量変動幅［ＨＰ］＝４となるため、圧縮機の運転容量の変動幅を２ＨＰとすると、必要となる高圧側容積は８Ｌとなる。この値が第１の所定容積である。従って高圧側の容積は８Ｌ以上になるように、高圧側を構成する各機器および配管の容積を考慮して高圧側容器１６の容量を設定する。
同様に、低圧の圧力変動幅を１ｋｇｆ／ｃｍ² 程度に押さえる場合には、運転容量制御間隔を１０秒で運転すると図１５より、低圧側容積［Ｌ］／運転容量変動幅［ＨＰ］＝１２．５となるため、圧縮機の運転容量の変動幅を２ＨＰとすると、必要となる低圧側容積は２５Ｌとなる。この値が第２の所定容積である。従って低圧側の容積は２５Ｌ以上になるように、低圧側を構成する各機器および配管の容積を考慮して低圧側容器１７の容量を設定する。
【００９２】
このように第１の所定容積または第２の所定容積を、圧縮機の運転により冷凍サイクルに発生する高圧側または低圧側の圧力変動幅の許容値と、短周期の長さと、短周期での圧縮機の運転容量変動幅とに基いて決定したことにより、高圧側または低圧側の容積を、運転条件や機器の構成や装置使用の際の快適性を満足するように設定できる。また、高圧側または低圧側に容器１６、１７を設けることで、圧縮機の運転容量の変動が生じても冷媒の密度の変動を小さくして、圧縮機の運転容量の変動に伴う圧力変動などの冷凍サイクル上の変動幅を抑制し、吹出空気温度の変動など冷凍能力、空調能力の変動を小さくし、冷凍空調装置運転の際の快適性を確保できるという効果がある。
【００９３】
なお、図１３では高圧側容器１６を圧縮機吐出側、低圧側容器１７を圧縮機吸入側に設けているが、設置場所はこれに限るものでなく、高圧側容器１６では圧縮機１ａ、１ｂの吐出口から膨張弁７によって減圧されるまでの冷凍サイクルの高圧部分、また低圧側容器１７では膨張弁７によって減圧されてから圧縮機１ａ、１ｂに吸入されるまでの部分のどの部分に設置しても同様の効果を得ることができる。
【００９４】
また、ここでは、高圧側と低圧側の両方の容積を所定値以上になるように構成したが、少なくともどちらか一方の容積を所定値以上になるように構成すれば、程度の差はあるが効果を奏する。
【００９５】
また、圧力変動を抑制するためには容器１６、１７を設けるという構成だけでなく、高圧側または低圧側それぞれの容積を増加させてもよい。例えば、室外機と室内機を接続する延長配管の配管径を大きくしてもよいし、配管長を長くしてもよいし、圧縮機１ａ、１ｂや室外熱交換器５を接続する配管の配管径を大きくしてもよいし、配管長を長くしてもよい。また室内熱交換器８ａ、８ｂや室外熱交換器５に用いられる伝熱管の径を大きくしたり、伝熱管の長さを長くしてもよい。いずれの構成においても、高圧側または低圧側それぞれの容積を増加させることができる。
【００９６】
以上のように、本参考の形態でも、インバータを用いずに運転することで、インバータを用いることによる高調波の悪影響がない。
さらに、段階的な容量で運転可能な圧縮機１ａとは別に圧縮機１ｂを備えており、時間制御運転での容量変動幅を小さくできる。さらに冷凍サイクルの高圧側と低圧側の少なくともどちらか一方の内容積の総量を、冷凍サイクルの圧力変動幅を小さくするような所定値以上とすることにより、段階的な容量で運転可能な圧縮機１ａにおいて、時間制御運転を行ったときの容量変動によって冷凍サイクル上に発生する圧力脈動幅、熱交換器での熱交換量の変動幅、熱交換器に空気熱交換器を用いた場合の吹出空気温度の変動幅などを小さくできる。このため、冷凍空調装置における冷凍能力または空調能力の変動を小さくでき、運転の際の快適性を確保できる冷凍空調装置を得ることができる。
【００９７】
参考の形態４．
以下、本発明の参考の形態４による冷凍空調装置として例えば室内の空調を行う装置について説明する。本参考の形態でも参考の形態３と同様、冷凍サイクルの高圧側と低圧側の少なくともどちらかに容器を設け、高圧側または低圧側の容積を増大させる。これにより、段階的な容量で運転可能な圧縮機を時間制御運転することによって冷凍サイクル上に発生する圧力脈動幅、熱交換器での熱交換量の変動幅、熱交換器に空気熱交換器を用いた場合の吹出空気温度の変動幅などを小さくして、冷凍空調装置における冷凍能力または空調能力の変動を小さくするものである。さらに本実施の形態では、高圧側または低圧側の容積を増加して圧力の変動を抑制することに加えて、高圧側容器または低圧側容器として冷凍サイクルを構成するうえで有効である他の機能も兼ね備えた容器を設けたものである。
【００９８】
図１６は本参考の形態による冷凍空調装置の構成を示す冷媒回路図である。図において、１７は低圧側容器、１８はオイルセパレータ、１９はオイルセパレータ１８で分離された油を圧縮機吸入側に戻す油戻し回路である。なお、図１６の他の構成、並びに冷媒の流れ、および図１６における圧縮機の容量の切り換え方法は実施の形態１と同様である。
【００９９】
圧縮機１ａ、１ｂ内には通常内部に各部材の動作を円滑に行なわせるために潤滑油が充填されている。この油の一部はガス冷媒と共に圧縮機１ａ、１ｂから排出し、冷媒と共に冷凍サイクルを循環する。ところが循環中にこの油が液管６やガス管９に貯まり込むと、圧縮機１ａ、１ｂに戻らずに圧縮機１ａ、１ｂ内の油量が減少する。圧縮機１ａ、１ｂ内の各部材の動作を潤滑に行わせる油が減少すると、圧縮機１ａ、１ｂの動作が円滑に行われなくなる。
本参考の形態では、圧縮機１ａ、１ｂの吐出側配管にオイルセパレータ１８を設け、このオイルセパレータ１８によって、圧縮機１ａ、１ｂからガス冷媒と共に吐出された油を分離し、油戻し回路１９を介して圧縮機１ａ、１ｂの吸入側に戻すことで、圧縮機１ａ、１ｂが破損するという状況を避けることができる。
さらにオイルセパレータ１８の分だけ高圧側の容積を増大させることで、段階的な容量で運転可能な圧縮機１ａの時間制御運転における圧力変動の抑制を可能としている。
【０１００】
このようにオイルセパレータ１８によって高圧側の容積を増加させるという機能と圧縮機１ａ、１ｂから排出される油を戻す機能とを兼ねている。このため、圧縮機１ａの時間制御運転による圧力の変動幅を抑制でき、冷凍空調装置運転の際の快適性を確保できると共に、圧縮機１ａ、１ｂを運転する際の信頼性を向上させることができる。通常、オイルセパレータ１８の容積は３Ｌ程度あり、冷凍サイクルを構成する高圧側の各機器および配管が５Ｌ程度とすると、図１４によれば、運転容量変動幅を２ＨＰ、運転容量制御間隔（短周期の長さ）を１０秒とすると、圧力変動幅を２ｋｇ／ｃｍ² 程度にすることができる。
このように、オイルセパレータ１８を圧縮機１ａ、１ｂの吐出側に設けることにより、冷凍空調装置運転の際の快適性を確保でき、かつ圧縮機を運転する際の信頼性を向上させることができる。
【０１０１】
また、図１７のように室外熱交換器５出口に液レシーバ３０を設けてもよい。室外熱交換器５は冷凍空調装置が冷房運転をしているとき、凝縮器として動作する。この凝縮器の出口に液レシーバ３０を設けることで、冷凍空調装置中の冷媒量を調整し、最適な冷凍サイクルの運転をよる最適な状態にする。さらに冷凍サイクル中の余剰な冷媒保持できるので、冷凍サイクル中に余剰冷媒があっても圧縮機１ａ、１ｂに液が戻る運転とはならず、液圧縮による圧縮機の破損を回避することができる。さらに、液レシーバ３０を設けることで、冷房運転においては高圧側の容積を増加して、段階的な容量で運転可能な圧縮機１ａが時間制御運転を行うことによって発生する圧力の変動幅を抑制する。
このように、液レシーバ３０を凝縮器として動作する熱交換器の出口に設けることにより、冷凍空調装置運転の際の快適性を確保でき、かつ圧縮機を運転する際の信頼性を向上させることができる。
なお、図のように液レシーバ３０を接続すると、暖房運転に切り換えたときには、低圧側の容積を増加する作用がある。
【０１０２】
また、図１８のように圧縮機１ａ、１ｂの吸入側にアキュムレータ３１を設けてもよい。アキュムレータ３１を設けることで、冷凍空調装置中の起動運転の際に圧縮機吸入側に流れてくる液冷媒をアキュムレータ３１に保持することで起動時に圧縮機１ａ、１ｂに液が戻る運転とはならず、液圧縮による圧縮機１ａ、１ｂの破損を回避して信頼性を向上することができる。さらに、アキュムレータ３１を設けることで、冷凍サイクルの低圧側の容積を増加することができ、圧縮機１ａが時間制御運転を行うことによって発生する圧力の変動幅を抑制でき、冷凍空調装置運転の際の快適性を確保することができ、
このように、アキュムレータ３１を冷凍サイクルの低圧側である圧縮機１ａ、１ｂの吸入側に設けることにより、冷凍空調装置運転の際の快適性を確保でき、かつ圧縮機を運転する際の信頼性を向上させることができる。
【０１０３】
なお、図１６、１６、１７では各冷凍空調装置が、オイルセパレータ１８、液レシーバ３０、アキュムレータ３１を有する構成としたが、これらすべてを有する構成でもよく、またいずれか２つを有する構成でもよい。また、オイルセパレータ１８、液レシーバ３０、アキュムレータ３１を有する構成でも容積が足りない場合には、図１５で示したように容積を増加するだけの機能を有するとして高圧側に冷媒容器１６または低圧側に冷媒容器１７を別に設けてもよい。
【０１０４】
参考の形態５．
以下、本発明の参考の形態５による冷凍空調装置として例えば室内の空調を行う装置について説明する。図１９は本参考の形態による冷凍空調装置の構成を示す冷媒回路図である。図において、３２は圧縮機の吐出側に設けられた流動抵抗を付加する抵抗素子で、例えば冷媒配管の一部の径を他の部分の径よりも細くして、冷媒の流れに対する抵抗素子を構成している。３３は圧縮機の吸入側に設けられた流動抵抗を付加する抵抗素子で、例えば抵抗素子３２と同様、冷媒配管の一部の径を他の部分の径よりも細くして、冷媒の流れに対する抵抗素子を構成している。なお、図１９の他の構成、並びに冷媒の流れ、および図１９における圧縮機の容量の切り換え方法は実施の形態１と同様である。
【０１０５】
前に述べたように、段階的な容量で運転可能な圧縮機１ａにおいて、時間制御運転を行う際に冷凍サイクル上に発生する圧力脈動は、圧縮機１ａに吸入および吐出される冷媒流量が短周期で変動することで、高圧側に流入する冷媒流量および低圧側から流出する冷媒流量が短時間で変動し、それに伴い高圧側および低圧側に存在する冷媒量を変動し、冷媒の密度の変動を引き起こすことで発生する。従って高圧側に流入する冷媒流量および低圧側から流出する冷媒流量の変動を抑制することができれば、冷凍サイクル上に発生する圧力脈動を抑制することができる。
【０１０６】
そこで本参考の形態では、圧縮機１ａの吐出側および吸入側に抵抗素子３２および抵抗素子３３を設ける。ここで、例えば圧縮機１ａの吐出側に設けた抵抗素子３２の作用について説明する。圧縮機１ａで時間制御運転を行なっており、運転容量が小さい段階の容量から大きい段階の容量に切り換わったときには、圧縮機１ａから吐出される冷媒流量は増加し、その増加分は抵抗素子３２の圧縮機側の圧力上昇に作用し、その後に抵抗素子３２を通過して冷媒流量の増加に寄与することになる。このため抵抗素子３２を設けないときに比べ、高圧側の冷媒量の増加を抑制することができる。
また、圧縮機１ａの時間制御運転で、運転容量が大きい段階の容量から小さい段階の容量に切り換わったときには、圧縮機１ａから吐出される冷媒流量は減少し、その結果、抵抗素子３２の圧縮機側に圧力減少が起こり、その圧力減少が起こる分だけの冷媒量が抵抗素子３２を通過する。このため抵抗素子３２を設けないときに比べ、高圧側の冷媒量の減少を抑制することができる。この動作は低圧側の抵抗素子３３に関しても同様である。
【０１０７】
このように冷媒流路に抵抗素子３２、３３を設けると、圧縮機１ａの運転容量の変化により圧縮機１ａに吸入および吐出される冷媒流量が変動をしても、抵抗素子３２、３３を冷媒が通過するときの流動抵抗によって、冷媒流量の変動分は抵抗素子３２、３３を通過しにくくなる。このため、高圧側に流入する冷媒流量および低圧側から流出する冷媒流量の変動を、圧縮機１ａで発生する冷媒流量の変動よりも小さくすることができる。
従って、冷凍サイクル上に発生する圧力脈動を抑制することができ、熱交換器での熱交換量の変動幅、熱交換器に空気熱交換器を用いた場合の吹出空気温度の変動幅などを小さくでき、冷凍空調装置における冷凍能力または空調能力の変動を小さくできるので、冷凍空調装置運転の際の快適性を確保できる。
【０１０８】
なお、図１９の構成では高圧側と低圧側にそれぞれ抵抗素子３２、３３を設けており、好ましくはどちらにも設けると効果が大きいが、どちらか一方でもある程度の効果を奏する。
また、流動抵抗を付加する抵抗素子は、キャピラリーのように冷媒配管内に絞り部を設けるなど、その配管を流れる冷媒に流動抵抗を付加する構成なら何でもよい。
【０１０９】
また、圧縮機の吐出側に設けた抵抗素子３２については、圧縮機１ａ、１ｂから四方弁４への方向の流れを通過させ、逆方向の流れを阻止する逆止弁としてもよい。このように高圧側の冷媒の流れに流動抵抗を付加する抵抗素子３２を逆止弁とすることで、冷凍サイクル上に発生する圧力脈動を抑制する効果に加え、冷凍空調装置の停止中に室外熱交換器５または室内熱交換器８ａ、８ｂから四方弁４を介して、圧縮機１ａ、１ｂの吐出側から圧縮機１ａ、１ｂに流入しようとする液冷媒の流れ込みを防ぐことができる。停止中に液冷媒の圧縮機１ａ、１ｂへの流れ込みを放置しておくと、冷凍空調装置を起動しようとしたときに、圧縮機１ａ、１ｂ内に液冷媒が流れ込んでいることにより、液圧縮を生じる恐れがあり、圧縮機１ａ、１ｂの破損をまねく可能性がある。これに対し、逆止弁３２を設けることで、冷凍空調装置を停止していても圧縮機１ａ、１ｂに液が流れ込むのを防止でき、液圧縮による圧縮機破損を防ぐことができ、より信頼性の高い運転が可能となる。
【０１１０】
なお、図２０に示すように、圧縮機１ａ、１ｂの吐出配管２ａ、２ｂのそれぞれに抵抗素子として逆止弁３２ａ、３２ｂを設けても、同様の効果を得ることができる。
【０１１１】
参考の形態６．
以下、本発明の参考の形態６による冷凍空調装置として例えば室内の空調を行う装置について説明する。図２１は、本参考の形態による冷凍空調装置の構成を示す冷媒回路図である。図において、３４はバイパス回路で、例えば圧縮機の吐出側と圧縮機の吸入側を接続する回路であり、３５はバイパス回路３４を流れる冷媒流量をコントロールする制御弁である。なお、図２１の他の構成、並びに冷媒の流れ、および図２１における圧縮機の容量の切り換え方法は実施の形態１と同様である。
【０１１２】
前に述べたように、段階的な容量で運転可能な圧縮機１ａにおいて、時間制御運転を行う際に冷凍サイクル上に発生する圧力脈動は、圧縮機１ａに吸入および吐出される冷媒流量が短周期で変動することで、高圧側に流入する冷媒流量および低圧側から流出する冷媒流量が短時間で変動し、それに伴い高圧側および低圧側に存在する冷媒量を変動し、冷媒の密度の変動を引き起こすことで発生する。従って高圧側に流入する冷媒流量および低圧側から流出する冷媒流量の変動を抑制することができれば、冷凍サイクル上に発生する圧力脈動を抑制することができる。
【０１１３】
そこで本参考の形態では、圧縮機１ａにおいて、時間制御運転を行う際には制御弁３５を開き、圧縮機１ａ、１ｂの吐出側から吸入側に冷媒が流れるようにする。圧縮機１ａが停止または短周期に一定容量運転を行なっている時には制御弁３５は閉じる。
圧縮機１ａで時間制御運転を行なっており、運転容量が小さい段階の容量から大きい段階の容量に切り換わったときには、圧縮機１ａに吸入および吐出される冷媒流量は増加し、高圧側に存在する冷媒量は増加し高圧は上昇すると共に、低圧側から流出する冷媒流量も増加し、低圧は低下する。従って、高圧と低圧の圧力差は増加する。圧力差が増加すると、バイパス回路３４を流れる冷媒流量は増加する。バイパス回路３４を流れる冷媒流量が増加するということは、高圧側から流出する冷媒流量、低圧側に流入する冷媒流量がともに増加するということになるので、バイパス回路３４に冷媒を流さないときに比べ、高圧側に存在する冷媒量の増加、および低圧側に存在する冷媒量の減少を抑制することができる。このように高圧側および低圧側に存在する冷媒量の変動を抑制できるので、冷凍サイクル上に発生する圧力脈動を抑制することが可能となる。
【０１１４】
また圧縮機１ａの時間制御運転で、運転容量が大きい段階の容量から小さい段階の容量に切り換わったときには、圧縮機１ａに吸入および吐出される冷媒流量は減少し、高圧側に存在する冷媒量は減少し高圧は低下するとともに、低圧側から流出する冷媒流量も減少し、低圧は上昇する。従って、高圧と低圧の圧力差は減少する。圧力差が減少すると、バイパス回路３４を流れる冷媒流量は減少する。バイパス回路３４を流れる冷媒流量が減少するということは、高圧側から流出する冷媒流量および低圧側に流入する冷媒流量がともに減少するということになるので、バイパス回路３４に冷媒を流さないときに比べ、高圧側に存在する冷媒量の減少、および低圧側に存在する冷媒量の増加を抑制することができる。このように高圧側および低圧側に存在する冷媒量の変動を抑制できるので、冷凍サイクル上に発生する圧力脈動を抑制することが可能となる。
【０１１５】
以上のように、本参考の形態では、バイパス回路３４と制御弁３５を設け、圧縮機１ａで時間制御運転を行っているときに冷凍サイクルの高圧側と低圧側を接続するので、時間制御運転中に生じる圧力変動によって自動的にその冷媒量の変動を小さくするような適量の冷媒がバイパス回路３４を流通し、時間制御運転により冷凍サイクル上に発生する圧力脈動幅、熱交換器での熱交換量の変動幅、熱交換器に空気熱交換器を用いた場合の吹出空気温度の変動幅などが小さくなる。このため、冷凍空調装置における冷凍能力または空調能力の変動を小さくでき、冷凍空調装置運転の際の快適性を確保できる。
【０１１６】
なお、制御弁３５を設けずに常にバイパス回路３４で高圧側と低圧側とを接続しておいてもよい。この時にはバイパス回路３４は、冷凍サイクルを構成する主配管の冷媒の流れに対して、１／１００〜１０／１００程度の冷媒が流れるように構成するのが望ましい。
もちろん、圧縮機の吐出側と吸入側を接続するバイパス回路３４に冷媒を流すということは、圧縮機の流量の一部を冷凍空調装置の冷房能力あるいは暖房能力に用いないことになるので、冷凍サイクルの運転効率を低下させる。従って、制御弁３５によって圧縮機１ａで時間制御運転を行っている以外のときには、このバイパス回路３４を閉止することで、冷凍サイクルの運転効率の低下を防止できる。
【０１１７】
また、このようにバイパス回路３４を圧縮機の吐出側と吸入側とを接続する回路とすることで、冷凍空調装置の負荷が増大したときや、凝縮器となる熱交換器の異常により、高圧が過上昇した場合には、制御弁３５を開としてバイパス回路３４に冷媒を流し、高圧の過上昇を抑制することもできる。バイパス回路３４によって高圧の冷媒を低圧側にバイパスすることで、高圧の過上昇に起因する圧縮機の破損を防止することができ、冷凍サイクル上に発生する圧力脈動を抑制することに加えて、冷凍空調装置の運転における信頼性を高めることができる。
【０１１８】
また、このバイパス回路３４を図１６にあるように、オイルセパレータ１８で分離した油を圧縮機吸入側に返す油戻し回路１９と兼用させてもよい。オイルセパレータ１８とすることにより、上記効果に加えて、圧縮機１ａ、１ｂの吐出側からガス冷媒と共に流出する圧縮機内の潤滑油を圧縮機に戻すことができ、潤滑油の不足による圧縮機の動作不良や破損を防止することができ、冷凍空調装置の信頼性を高めることができる。
【０１１９】
また、高圧側と低圧側を接続するバイパス回路３４を、圧縮機の吐出側と吸入側を接続するバイパス回路３４に限るものではなく、他の構成にしてもよい。
図２２は本参考の形態による冷凍空調装置の他の構成を示す冷媒回路図である。この構成では、バイパス回路３４の一端を室外熱交換器５と膨張弁７ａ、７ｂの間の液管６に接続し、バイパス回路３４の他端を圧縮機の吸入配管３ａ、３ｂとを接続している。このように構成することで、冷房運転時には、室外熱交換器５は凝縮器として動作している。従って、高圧側となる室外熱交換器５出口と低圧側となる圧縮機吸入側とを接続することになるので、圧縮機の吐出側と吸入側を接続した場合と同様に、冷凍サイクル上に発生する圧力脈動を抑制することが可能となる。
またこのように接続すると、冷房運転時には室外熱交換器５で凝縮された液冷媒を圧縮機１ａ、１ｂに戻すことができる。例えば運転中に圧縮機１ａ、１ｂの吐出温度が上昇した場合には、制御弁３５を開として液冷媒を圧縮機１ａ、１ｂに戻すことで、吐出温度の上昇を抑制することができ、圧縮機運転の信頼性を高めることが可能となる。
図２２、図２３における制御弁３５は、バイパス回路３４を開閉する開閉機能を有するものであればよい。
【０１２０】
また、図２３は本参考の形態による冷凍空調装置のさらに他の構成を示す冷媒回路図である。図において、３６はバイパスされた液冷媒と高圧の液冷媒とを熱交換する熱交換部で、例えば高低圧熱交換器である。この構成の制御弁３５は減圧機能を有するものである。
冷房運転時にバイパス回路３４を流れる液冷媒は、制御弁３５によって減圧されて低圧低温の二相冷媒となる。この二相冷媒と液管６を流れる高圧高温の液冷媒を高低圧熱交換器３６で熱交換することで、低圧の二相冷媒は蒸発ガス化される。従って、バイパス回路３４によって冷凍サイクル上に発生する圧力脈動を抑制することに加え、バイパスされる液冷媒の蒸発潜熱を回収することができ、冷房運転時に液冷媒をバイパスすることによる冷房能力の低下を低減することができる。
さらに、冷房運転中に室外熱交換器５から室内熱交換器８ａ、８ｂを流れる冷媒流量を冷房能力の低下なく減らすことができるため、ガス管９で生じる圧力損失を減らすことが可能となり、より高効率で冷凍空調装置を運転することが可能となる。
【０１２１】
参考の形態７．
以下、本発明の参考の形態７による冷凍空調装置として例えば室内の空調を行う装置について説明する。図２４は、本参考の形態による冷凍空調装置の構成を示す冷媒回路図である。本参考の形態では図に示すように、オイルセパレータ１８で分離された油の油戻し回路１９を高圧側電磁弁１０ａに接続し、オイルセパレータ１８で分離された油を高圧側電磁弁１０ａに供給する。そしてこれが開となったときに高圧側電磁弁１０ａを通過して低圧側電磁弁１０ｂに供給される。供給された油は低圧側電磁弁１０ｂに流入し、その後これが開となったときに低圧側電磁弁１０ｂを通過し、圧縮機吸入側に戻される。なお、図２４の他の構成、並びに冷媒の流れ、および図２４における圧縮機の容量の切り換え方法は実施の形態１と同様である。
【０１２２】
本参考の形態のように、圧縮機１ａの運転容量の切り換えを２つの制御弁である高圧側電磁弁１０ａ、低圧側電磁弁１０ｂの開閉で行う場合、各電磁弁の開閉回数は多くなる。例えば、圧縮機１ａを最大容量で運転する時間と最小容量で運転する時間を１セットで考え、最大容量で運転する時間と最小容量で運転する時間を合計した短周期の長さを１０秒、圧縮機１ａの運転時間を２万５千時間とした場合、電磁弁１０ａ、１０ｂそれぞれの開閉回数は９００万となり、一般の電磁弁における耐用開閉回数の数十万回というレベルよりはかなり多い耐用開閉回数が必要となる。
【０１２３】
図２５は本参考の形態に係わる電磁弁１０ａ、１０ｂの構造を示す断面図である。図において、３７は可動弁、３８は弁座、３９はプランジャー、４０はコイル、４１は弁入口側流路、４２は弁出口側流路である。電磁弁１０ａ、１０ｂの動作は以下のようになる。
弁を開く場合には、コイル４０に電流を流し、電磁力によって可動弁３７からプランジャー３９への磁力を発生させることで可動弁３７をプランジャー３９に吸引させる。プランジャー３９が図における上方に移動すると、可動弁３７と弁座３８の間に空隙が生じ、弁入口側流路４１と弁出口側流路４２が通じ、弁が開いた状態となる。
弁を閉じる場合には、コイル４０に電流が流れないようにする。すると可動弁３７からプランジャー３９への磁力がなくなり可動弁３７をプランジャー３９に吸引させる力がなくなる。このためプランジャー３９が図における下方に移動する一方で、流れる冷媒の圧力は弁出口側４２より弁入口側４１の方が高いので冷媒の圧力差によって、可動弁３７は弁座３８に押しつけられる。こうすることで可動弁３７と弁座３８の間の空隙がなくなり、弁入口側流路４１と弁出口側流路４２の間は閉止される。
【０１２４】
従って、電磁弁１０ａ、１０ｂを開閉するたびに、プランジャー３９と可動弁３７、および可動弁３７と弁座３８が衝突するため、電磁弁１０ａ、１０ｂの開閉回数を増加させるとプランジャー３９、可動弁３７、弁座３８などの摩耗が進む。特に、摩耗によって可動弁３７と弁座３８の間に隙間ができて完全閉止できなくなる恐れがある。そこで本参考の形態では可動弁３７や弁座３８の摩耗を防ぎ、所定の耐用開閉回数を確保するために、オイルセパレータ１８で分離された油を電磁弁１０ａ、１０ｂに供給するように構成している。電磁弁１０ａ、１０ｂに油を供給することで、可動弁３７と弁座３８との接触部、プランジャー３９と可動弁３７との接触部、可動弁３７と容器内面との摺動部などに油膜が形成される。この油膜が電磁弁１０ａ、１０ｂの開閉によって接触する部分、例えば可動弁３７と弁座３８との接触部での衝突における衝撃を緩和する衝撃緩和手段となり、可動弁３７や弁座３８などの接触部の摩耗を防止できる。
【０１２５】
なお、この油膜は少量の油で形成可能であり、圧縮機１ａ、１ｂからの油の持ち出し量が多いと、電磁弁１０ａ、１０ｂに供給される油量が多くなり過ぎてしまう場合も生じる。電磁弁１０ａ、１０ｂに供給される油量が多過ぎて電磁弁１０ａ、１０ｂ内が油で充満すると、冷媒に比べて油の粘性が大きいため、電磁弁１０ａ、１０ｂ内の油の量が多くなるにつれて電磁弁１０ａ、１０ｂの開閉により多くの電磁力が必要となる。従って冷媒を用いた場合に電磁弁１０ａ、１０ｂを開閉できるように設計していると、弁内に油が充満したときは電磁力不足で電磁弁１０ａ、１０ｂが十分に開閉できず、これに起因して圧縮機の容量制御を実施できなくなる場合も生じる。従って電磁弁１０ａ、１０ｂに油を供給する際、その電磁弁１０ａ、１０ｂに最適な量の油を供給する必要がある。
【０１２６】
そこで、本参考の形態では電磁弁１０ａ、１０ｂに油を供給する際の油の状態に対してさまざまな構成を提供している。
まず、図２４に示した構成では、圧縮機から冷媒ガスと共に流出した油をオイルセパレータ１８で分離し、冷媒の混ざっていない油を電磁弁１０ａ、１０ｂに供給している。この場合電磁弁１０ａ、１０ｂに供給される油量は比較的多い。
【０１２７】
また、図２６に示した構成では、圧縮機１ａ、１ｂとオイルセパレータ１８の間の圧縮機吐出側と高圧側電磁弁１０ａを接続することで、電磁弁１０ａ、１０ｂにオイルセパレータ１８通過前の冷媒ガスを供給する。この場合電磁弁１０ａ、１０ｂに供給される油量は、オイルセパレータ１８の油戻し回路１９を電磁弁１０ａに接続する構成、即ち図２４に示した構成のものよりも少なくなる。これは、オイルセパレータ１８を通過前の冷媒ガスを供給することで、電磁弁１０ａ、１０ｂには油と共に冷媒ガスが供給され、分離後の油を供給するよりも油量は少なくなる。
【０１２８】
また、図２７に示した構成では、オイルセパレータ１８と四方弁４の間の圧縮機吐出側と高圧側電磁弁１０ａを接続することで、電磁弁１０ａ、１０ｂにオイルセパレータ１８通過後の冷媒ガスを供給する。この場合にはオイルセパレータ１８で冷媒ガスに含まれる油が除かれるので、電磁弁１０ａ、１０ｂに供給される油量は、オイルセパレータ１８通過前の冷媒ガスを供給する構成、即ち図２６に示した構成のものよりも少なくなる。ただし、オイルセパレータ１８では冷媒ガスに含まれる油を完全に除去できないので、オイルセパレータ１８通過後の冷媒ガスを供給しても少量の油量は供給可能である。どの程度の油量が供給されるかは、オイルセパレータ１８の性能にも大きく左右される。
【０１２９】
図２４、図２６、図２７のように、電磁弁１０ａ、１０ｂに供給する油量は増減可能であるので、圧縮機１ａ、１ｂからの油の流出状態や、油や冷媒の性質、オイルセパレータの性能などに応じてその構成を選べばよい。
例えば圧縮機１ａ、１ｂから持ち出される油量が多過ぎる場合、図２４のようにオイルセパレータ１８の油戻し回路１９を電磁弁１０ａに接続すると、電磁弁１０ａ、１０ｂ内に油が充満してしまう可能性がある。このときには、図２６のようにオイルセパレータ１８通過前の冷媒ガスを供給する。また、図２６のようにオイルセパレータ１８通過前の冷媒ガスを供給しても、電磁弁１０ａ、１０ｂ内に油が充満してしまうときには、図２７のようにオイルセパレータ１８通過後の冷媒ガスを供給すればよい。
【０１３０】
逆に例えば圧縮機１ａ、１ｂから持ち出される油量が少ない場合、図２７のように電磁弁１０ａにオイルセパレータ１８通過後の冷媒ガスを供給すると、可動弁３７と弁座３８の表面などの接触部に衝撃緩和作用のための油膜を形成できない可能性がある。このときには、図２６のように電磁弁１０ａにオイルセパレータ１８通過前の冷媒ガスを供給する。また、図２６のようにオイルセパレータ１８通過前の冷媒ガスを供給しても、可動弁３７と弁座３８の表面に油膜を形成できないときには、図２４のようにオイルセパレータ１８の油戻し回路１９を電磁弁１０ａに接続して分離後の油を供給すればよい。
【０１３１】
以上のように、本参考の形態では、図２４、図２６、図２７の構成によって、圧縮機１ａ、１ｂから冷媒ガスと共に流出した油を電磁弁１０ａ、１０ｂに供給してから圧縮機１ａ、１ｂに戻す構成とした。このため、電磁弁１０ａ、１０ｂの開閉による接触部、例えば可動弁３７、弁座３８の表面に油膜を生じさせて衝撃を緩和することにより、その接触部の摩耗を防止し、弁の閉止性能を確保する。
さらに、図２４、図２６、図２７の構成のうちで、圧縮機１ａ、１ｂからの油の流出量や、油の性質による接触部の油膜のでき具合などに基づいて、その冷凍空調装置に最適な構成を選択することで、電磁弁１０ａ、１０ｂに油を適量供給でき、電磁弁内に油を充満させず、確実に弁の開閉動作を行うことができ、弁駆動の際の信頼性を確保することが可能となる。
【０１３２】
参考の形態８．
以下、本発明の参考の形態８による冷凍空調装置として例えば室内の空調を行う装置について説明する。本参考の形態は、圧縮機１ａの時間制御運転を行う際の制御弁である電磁弁１０ａ、１０ｂを冷却する冷却手段を備え、膨張弁１０ａ、１０ｂの温度上昇による各部材の劣化を防止しようとするものである。
図２８は、本参考の形態による冷凍空調装置の構成を示す冷媒回路図である。図において、７ｃは膨張弁であり、４３は高圧液冷媒を電磁弁１０ａに供給する配管である。なお、図２８の他の構成は実施の形態１と同様である。実施の形態１〜実施の形態７では、冷媒ガスの流れる配管と高圧側電磁弁１０ａを接続する構成だったが、図２８の構成では冷媒液の流れる配管と高圧側電磁弁１０ａとを接続する構成としている。この高圧液冷媒を電磁弁１０ａ、１０ｂに供給することにより、電磁弁１０ａ、１０ｂの開閉による運転容量の制御動作に支障をきたさず、かつ電磁弁１０ａ、１０ｂを冷却し、さらには電磁弁１０ａ、１０ｂに冷媒と共に流れている油を供給する。
【０１３３】
本参考の形態は、膨張弁７ｃを冷房運転時に凝縮器として動作する室外熱交換器５の出口側に設け、その膨張弁７ｃと膨張弁７ａ、７ｂとの間の液管６と高圧側電磁弁１０ａとを配管４３で接続する。ここで室外熱交換器５と膨張弁７ａ、７ｂとの間に膨張弁７ｃを設けたことにより、冷房運転と暖房運転のどちらの運転においても、圧縮機１ａの時間制御運転を行う際の制御弁である電磁弁１０ａ、１０ｂに高圧液冷媒を供給できるようにしている。
冷房運転では膨張弁７ｃを全開として減圧しないようにすることで、室外熱交換器５で凝縮された高圧液冷媒の一部を電磁弁１０ａ、１０ｂに供給する。電磁弁１０ａ、１０ｂに供給されなかった冷媒は、膨張弁７ａ、７ｂで減圧され、室内熱交換器８ａ、８ｂに流入する。冷房運転でのその他の冷媒の流れおよび圧縮機の容量の切り換え方法は実施の形態１と同様である。
一方暖房運転では膨張弁７ａ、７ｂを全開として減圧しないようにすることで、室内熱交換器８ａ、８ｂで凝縮された高圧液冷媒を電磁弁１０ａ、１０ｂに供給する配管４３の接続地点まで冷媒を流す。そして一部は配管４３へ流れて電磁弁１０ａ、１０ｂに供給される。配管４３へ流れなかった高圧液冷媒は、膨張弁７ｃで減圧された後、室外熱交換器５に流入する。暖房運転のその他の冷媒の流れおよび圧縮機の容量の切り換え方法は実施の形態１と同様である。
【０１３４】
本参考の形態でも、圧縮機１ａの時間制御運転での運転容量の切り換えを高圧側電磁弁１０ａ、低圧側電磁弁１０ｂの開閉で行っており、前述のように各電磁弁１０ａ、１０ｂの開閉回数が多くなる。運転容量を切り換える際には、電磁弁１０ａ、１０ｂのコイル４０に間断なく電流が流れるため、コイル４０の発熱量が多くなり、電磁弁１０ａ、１０ｂそのものの温度が上昇する。電磁弁１０ａ、１０ｂの温度が上昇すると、電磁弁１０ａ、１０ｂの材質に劣化を起こしやすくなり、電磁弁１０ａ、１０ｂの動作不良を引き起こしやすくなる。従って電磁弁１０ａ、１０ｂの駆動の信頼性を確保するには、電磁弁１０ａ、１０ｂの冷却が必要となる。本参考の形態では、この冷却熱源として、高圧液冷媒を用いる。なお電磁弁１０ａ、１０ｂの動作としては、圧縮機１ａの容量を切り換えるため、電磁弁１０ａを開（電磁弁１０ｂを閉）としたときに容量制御用配管１５ａに高圧がかかり、電磁弁１０ｂを開（電磁弁１０ａを閉）としたときに容量制御用配管１５ａに低圧がかかればよい。図２８の構成では、冷房運転および暖房運転のどちらにおいても、高圧側電磁弁１０ａを開として配管４３から高圧液冷媒を供給できるので、容量制御用配管１５には高圧がかけられるため圧縮機１ａの運転容量の制御性については問題は生じない。
【０１３５】
ここで、冷凍サイクルで凝縮後の高圧液冷媒を電磁弁１０ａ、１０ｂに供給することで、電磁弁１０ａ、１０ｂを冷却する冷却手段の作用も兼ねている。即ち、配管４３から供給された高圧液冷媒は、高圧側電磁弁１０ａに流入してこれを冷却する。電磁弁１０ａ、１０ｂは短周期で交互に開閉制御されており、この開のタイミングで高圧側電磁弁１０ａから低圧側電磁弁１０ｂに流入してこれを冷却する。
高圧液冷媒の温度は、冷凍サイクルの凝縮温度程度であり、５０℃程度である。電磁弁１０ａ、１０ｂの材質の劣化は電磁弁の温度が１２０℃まで冷却できれば、防止できるように設計されており、５０℃程度の高圧液冷媒を電磁弁１０ａ、１０ｂに供給することで、電磁弁１０ａ、１０ｂを十分に冷却できる。
【０１３６】
このように本参考の形態では、高圧液冷媒を電磁弁１０ａ、１０ｂに供給してこれらを冷却することで、温度上昇による電磁弁１０ａ、１０ｂの材質の劣化を防止し、電磁弁１０ａ、１０ｂの寿命を長くでき、開閉動作における信頼性を高めることができる。
【０１３７】
図２９は本参考の形態８による冷凍空調装置の他の構成を示す説明図であり、図２９（ａ）は室外機を正面から見た時の構成を示し、図２９（ｂ）は室外機を側面から見た時の構成を示す。この構成では、電磁弁１０ａ、１０ｂを冷却する冷却手段として、冷凍空調装置の周囲の外気によって冷却する構成としたものである。
【０１３８】
室外機４４は、圧縮機１ａ、１ｂ、四方弁４、空気を熱源とする室外熱交換器５などを搭載したものであり、図２９では、室外機４４の上３／４程度の部分に室外熱交換器５が配置されている。図２９（ｂ）の矢印のように、前面、背面から吸い込まれた空気が室外熱交換器５において熱交換した後、上部に空気が排出される構造となっている。また室外機４４の下１／４部分は機械室４５となっており、圧縮機１ａや電磁弁１０ａ、１０ｂが配置されている。ここで室外機４４の風の流れを図２９（ｂ）に示すように一部機械室４５を通過させることにより、機械室４５内に配置されている電磁弁１０ａ、１０ｂを外気で冷却することが可能となる。外気の温度は高くても４０℃程度であるので、電磁弁の温度を１２０℃以下に冷却することが可能となる。
【０１３９】
このように空気によっても電磁弁１０ａ、１０ｂを十分に冷却でき、電磁弁１０ａ、１０ｂの温度上昇による各部材の材質の劣化を防止し、電磁弁１０ａ、１０ｂの駆動の際の信頼性を高めることができる。
【０１４０】
参考の形態９．
以下、本発明の参考の形態９による冷凍空調装置に係わる制御弁について説明する。図３０は、本参考の形態による制御弁の構成を示す断面図である。図において、４６ａ、４６ｂは減速手段で、例えばバネである。他の構成は図２５と同様である。
段階的な容量で運転可能な圧縮機１ａの時間制御運転の際の切り換えを行う制御弁は、前述のように多くの耐用開閉回数を要求される。この制御弁は、可動弁３７の移動によって流路を開閉する構成であり、流路を閉とした時の可動弁３７と弁座３８、流路を開とした時のプランジャー３９と可動弁３７などの接触部における強度を考えると、これらの接触部の材質には、石や金属を使うことが望ましい。ただし、接触部のそれぞれの材質として石や金属を用いると、従来技術の課題で述べたように可動弁３７と弁座３８などが衝突したときに衝突音が発生する。特に圧縮機１ａの時間制御運転を行う場合には、電磁弁１０ａ、１０ｂの開閉回数が数秒〜数十秒に一回あるので、数秒〜数十秒に一回、衝突音が発生する。従って衝突音が大きいと騒音として室外機４４に間断なく音が発生することになり、周囲の環境に対して問題となる。このため、電磁弁１０ａ、１０ｂに対しては信頼性を高めると共に、発生する駆動音の低減が必要となる。
【０１４１】
本実施の形態では、衝撃緩和手段として、電磁弁１０ａ、１０ｂを閉とする際に接触する部分、例えば可動弁３７と弁座３８が互いに接触する部分の材質として、樹脂の一つであるテフロンを用いる。テフロンは石や金属に比べ柔らかく、ある程度の衝撃に対して強度もあるので、可動弁３７と弁座３８との衝突の際の衝撃力を吸収し、石や金属を使うときに比べ衝突音を低減することが可能となる。
また同様に、電磁弁１０ａ、１０ｂを開とする際に接触する部分、例えば可動弁３７がプランジャー３９に吸引され、可動弁３７がプランジャー３９に衝突するときの衝突音の低減も必要となる。そこで可動弁３７とプランジャー３９が互いに接触する部分にもそれぞれ例えばテフロンを用い、衝突音を低減させる。
【０１４２】
また他の衝撃緩和手段として、可動弁の移動速度を減速して制御弁の開閉による衝撃を緩和することもできる。図３０に示すように、可動弁３７の上部と下部に弾性体であるバネ４６ａ、４６ｂを配置する。バネ４６ａの一端は弁座３８に接続され他端は可動弁３７に接続されている。このバネ４６ａにより、流路を閉とした時可動弁３７が下方に移動して弁座３８に当たる速度を低減できるので、可動弁３７と弁座３８の衝突をやわらげることができる。このため、可動弁３７と弁座３８の摩耗を抑制でき電磁弁１０ａ、１０ｂの開閉動作の信頼性を高めるとともに、衝突音の発生を低減することが可能となる。
また上部に配置されたバネ４６ｂの一端はプランジャー３９に接続され他端は可動弁３７に接続されている。このバネ４６ｂにより、流路を開とした時可動弁３７が上方に移動してプランジャー３９に当たる速度を低減できるので、衝突するときには、上部に配置されたバネ４６により、衝突の速度を低減できるので、可動弁３７とプランジャー３９の衝突をやわらげる。このため、可動弁３７とプランジャー３９の摩耗を抑制でき電磁弁１０ａ、１０ｂの開閉動作の信頼性を高めるとともに、衝突音の発生を低減することが可能となる。
なお、バネ４６ａ、４６ｂの固定側に接続している端部は、上記構成に限るものではなく、制御弁内の固定側のどこに接続してもよい。
【０１４３】
参考の形態１０．
以下、本参考の実施の形態１０による冷凍空調装置として例えば室内の空調を行う装置について説明する。図３１は、本参考の形態による冷凍空調装置の構成を示す冷媒回路図である。図において、４７ａは冷凍サイクルの高圧を測定する圧力測定手段でここでは圧力センサ、４７ｂは冷凍サイクルの低圧を測定する圧力測定手段でここでは圧力センサ、４８ａ、４８ｂは室内熱交換器８ａ、８ｂの冷房運転での出口温度を測定する温度測定手段でここでは温度センサ、４８ｃ、４８ｄは室内熱交換器８ａ、８ｂの暖房運転での出口温度を測定する温度測定手段でここでは温度センサである。なお、図３１の他の構成、並びに冷媒の流れ、および図３１における圧縮機の容量の切り換え方法は実施の形態１と同様である。
【０１４４】
本参考の形態では、運転中に冷凍サイクルの運転情報として、高圧、低圧、室内熱交換器８ａ、８ｂの出口温度などを圧力センサ４７ａ、４７ｂ、温度センサ４８ａ、４８ｂ、４８ｃ、４８ｄによって測定する。そしてこの測定された運転情報に基づいて、制御手段（図示せず）によって圧縮機１ａ、１ｂの運転容量制御、および膨張弁７ａ、７ｂの開度の制御を行う。制御手段での圧縮機１ａ、１ｂの運転容量制御は実施の形態１に示した方法と同様の方法であり、圧縮機１ａでは短周期の時間配分を振り分けた各時間で圧縮機１ａを異なる段階の容量で運転し、その時間配分を変化させて短周期での平均容量を変化させ、これに圧縮機１ｂの運転、停止を組み合わせて全体として連続的に運転容量を変化させる。また膨張弁７ａ、７ｂの開度は、冷房運転時には低圧（圧力センサ４７ｂで測定）、および冷房運転での室内熱交換器８ａ、８ｂの出口温度（温度センサ４８ａ、４８ｂで測定）に基づいて室内熱交換器出口での過熱度を求め、過熱度が予め設定された目標値となるように制御を行う。また暖房運転時には高圧（圧力センサ４７ａで測定）、および暖房運転での室内熱交換器８ａ、８ｂの出口温度（温度センサ４８ｃ、４８ｄで測定）をもとに室内熱交換器出口での過冷却度を求め、過冷却度が予め設定された目標値となるように制御を行う。
【０１４５】
本参考の形態での課題は、測定した運転情報がばらつき易いという点である。即ち、段階的な容量で運転可能な圧縮機１ａにおいて、時間制御運転を行って段階的に容量を短周期で切り換える場合には、測定される圧力や温度の情報が変動するため、変動した情報を基に制御を行うと安定した制御を行えないことになる。図３２は、運転情報、例えば圧力の測定方法を示す説明図であり、横軸に時間を示し、縦軸に圧縮機の運転容量とそれに伴う圧力を示す。圧縮機１ａが例えば最大容量と最小容量の２段階を短周期で切り換える時間制御運転を行っているとき、圧縮機運転容量が最小容量から最大容量に変化すると、高圧は高く、低圧は低くなり、逆に圧縮機運転容量が最大容量から最小容量に変化すると、高圧は低く、低圧は高く変化する。
【０１４６】
そこで本参考の形態では図３２に点線で示した時間のタイミングで圧力や温度の測定を行っている。例えば圧縮機１ａの運転容量が切り換わる時間、即ち短周期の時間よりも短い一定の時間間隔で圧力や温度を所定期間測定し、その期間に測定された複数の測定値の平均値を求め、その平均値をもとに運転制御を行う。得られた運転情報の平均値には、圧縮機１ａの時間制御運転で生じる変動による影響が無くなりまた無視できるほど低減され、この運転情報に基づいて安定した運転制御を行うことができる。ここで、測定する所定期間は短周期の長さ以上とする。
【０１４７】
また、上記のようにして測定した複数の運転情報の平均値を求めて運転制御を実施する以外にも、所定期間の間に測定された複数の測定値のうちの最大値をもとにして制御を行ってもよいし、また所定期間の間に測定された複数の測定値のうちの最小値をもとにして制御を行ってもよい。また複数の測定値を大から小あるいは小から大の順番に並べ順位付けし、ある一定順位の測定値をもとに制御を行ってもよい。いずれの場合においても、短周期以上の期間に測定した複数の運転情報に基づいて制御することで、圧力や温度などの運転情報の変動を無くして測定することができ、安定した運転制御を行うことができる。
【０１４８】
次に、本参考の形態による冷凍空調装置に係わる運転情報の別の測定方法について説明する。図３３に点線で示した時間のタイミングで圧力や温度の測定を行う。即ち、圧縮機１ａの運転容量が最小容量から最大容量に段階的に切り換わる時間と最大容量から最小容量に段階的に切り換わる時間のおおよそ中間のタイミングで圧力や温度の測定を行うようにしてもよい。このようなタイミングで計測することで、圧力や温度の情報を、変動の影響なく測定することができる。また短周期内の中間のタイミングで測定すると、圧力変動が生じていても変動した圧力のほぼ平均値となる値の測定を行えるので、冷凍サイクルの平均した状況を捉えることが可能となる。
【０１４９】
また、測定を行うタイミングは圧縮機の運転容量が最小容量から最大容量に切り換わる時間と最大容量から最小容量に切り換わる時間のおおよそ中間に限るものでもなく、圧縮機の運転容量が最小容量から最大容量に切り換わる時間と最大容量から最小容量に切り換わる時間の間のある定められたタイミングで行ってもよい。
また圧縮機の運転容量が最大容量から最小容量に切り換わる時間と最小容量から最大容量に切り換わる時間の間のある定められたタイミングで測定を行っても、同様に運転情報を変動を無くして測定することができる。即ち、短周期内の所定の時間に計測すれば、変動の影響ない運転情報が得られ、この情報に基づいて運転制御することにより、安定した制御を行うことができる。この短周期内の所定時間は、予め実験などにより、安定して測定ができることを確認して設定すればよい。
また、常に短周期の範囲の所定の時間に計測しなくても、変動の特徴、例えば短周期の時間とその範囲で計測値が変動する変動幅を予め実験などにより把握しておくことで、測定値を補正できれば、短周期の範囲で常に所定時間に計測しなくてもよく、計測タイミングに制限はなくなる。
【０１５０】
また、参考の形態３〜参考の形態１０において、段階的な容量で運転可能な圧縮機１ａの他に一定容量の圧縮機１ｂを有する冷凍空調装置について説明したが、この一定容量の圧縮機１ｂを有する構成でなくてもよく、また、一定容量の圧縮機１ｂを複数有するものでもよく、また、実施の形態１のように他に段階的な容量で運転可能な圧縮機を複数有する構成でも、各実施の形態や参考の形態と同様の効果を奏する。冷凍空調装置が、少なくとも段階的な容量で運転可能な圧縮機を１台有する構成にしてもよい。特に圧縮機を複数設けることで、運転パターンをさまざまに組み合わせることができるので、運転容量の組み合わせ範囲が広がる。また、段階的な容量で運転可能な圧縮機を複数設けることで、容量変動幅を小さくでき、さらに効果的である。
【０１５１】
また、実施の形態１〜参考の形態１０では、室内熱交換器２台の組み合わせの場合として説明したが、室内熱交換器の台数としては１台であっても３台以上であっても同様の効果を得ることができる。
【０１５２】
また、実施の形態１〜参考の形態１０による冷凍空調装置に使用する冷媒においても、現在冷凍空調装置に多く用いられているＲ２２だけでなく、Ｒ１３４ａ、Ｒ３２などのＨＦＣ系冷媒、ＨＦＣ系冷媒の混合冷媒であるＲ４０７Ｃ、Ｒ４１０Ａ、Ｒ４０４Ａ、またアンモニア、プロパンやブタンなどの自然冷媒、およびこれらの冷媒の混合冷媒を用いても同様の効果を得ることができる。
【０１５３】
【発明の効果】
本発明の冷凍空調装置によれば、段階的な容量で運転可能な圧縮機を少なくとも１台と、前記圧縮機とは別に段階的な容量で運転可能な圧縮機または一定の容量で運転する圧縮機を少なくとも１台備え、前記段階的な容量で運転可能な圧縮機を、短周期の時間配分を振り分けた各時間で異なる段階の容量で運転し、前記時間配分を変化させて前記短周期での平均容量を変化させ、複数の前記圧縮機の全体運転容量を連続的に可変とすることにより、インバータを用いることによる高調波の悪影響がなく、圧縮機の運転容量の変動を小さくしてこれに伴う圧力変動などの冷凍サイクル上の変動幅を抑制し、吹出し空気温度の変動など冷凍能力、空調能力の変動を小さくし、冷凍空調装置運転の際の快適性を確保できるという効果がある。
【０１５４】
本発明の冷凍空調装置によれば、複数の圧縮機全体の運転容量を、少なくとも２台の段階的な容量で運転可能な圧縮機に分担して運転する場合、前記段階的な容量で運転可能な圧縮機に分担する運転容量が、その圧縮機の段階的容量の内のそれぞれ最小容量と一致するのを避けて分担することにより、圧縮機の運転容量の変動に伴う圧力変動などの冷凍サイクル上の変動幅を抑制し、吹出し空気温度の変動など冷凍能力、空調能力の変動を小さくし、運転圧縮機の吐出温度を同等に出来安定して運転できるという効果がある。
【０１５５】
本発明の冷凍空調装置によれば、少なくとも２台の段階的な容量で運転可能な圧縮機をそれぞれ、短周期の時間配分を振り分けた各時間で異なる段階の容量で運転する場合、前記各圧縮機の運転容量の合計の前記短周期内での時間的な変動が、その短周期に運転する前記各圧縮機の大きい方の運転容量の合計と小さい方の運転容量の合計との差よりも小さくなるように、前記各圧縮機の短周期の時間配分とその各時間の運転容量を組み合わせて運転することにより、圧縮機の運転容量の変動を小さくしてこれに伴う圧力変動などの冷凍サイクル上の変動幅を抑制し、吹出し空気温度の変動など冷凍能力、空調能力の変動を小さくし、冷凍空調装置運転の際の快適性を確保できるという効果がある。
【０１５６】
本発明の冷凍空調装置は、段階的な容量で運転可能な圧縮機を２台備え、短周期の内で、一方の圧縮機がその段階の大きいほうの容量の運転を行う時間の少なくとも一部の時間に、他方の圧縮機がその段階の小さい方の容量の運転を行うと共に、他方の圧縮機がその段階の大きいほうの容量の運転を行う時間の少なくとも一部の時間に、一方の圧縮機がその段階の小さい方の容量の運転を行うようにしたことにより、圧縮機の運転容量の変動を小さくしてこれに伴う圧力変動などの冷凍サイクル上の変動幅を抑制し、吹出し空気温度の変動など冷凍能力、空調能力の変動を小さくし、冷凍空調装置運転の際の快適性を確保できるという効果がある。
【図面の簡単な説明】
【図１】 本発明の実施の形態１による冷凍空調装置の構成を示す冷媒回路図である。
【図２】 実施の形態１に係わるスクロール圧縮機の圧縮室を示す断面図である。
【図３】 実施の形態１に係わるスクロール圧縮機の圧縮室を示す平面図である。
【図４】 実施の形態１に係わる電磁弁の時間的な開閉制御の様子を示す説明図である。
【図５】 実施の形態１に係わり、各圧縮機の運転容量の変化を示し、必要運転容量［ＨＰ］に対する圧縮機運転容量［ＨＰ］を示すグラフである。
【図６】 本発明の実施の形態２による冷凍空調装置の構成を示す冷媒回路図である。
【図７】 実施の形態２に係わり、各圧縮機の運転容量の変化の一例を示し、必要運転容量［ＨＰ］に対する圧縮機運転容量［ＨＰ］を示すグラフである。
【図８】 実施の形態２に係わり、各圧縮機の運転容量の変化の他の例を示し、必要運転容量［ＨＰ］に対する圧縮機運転容量［ＨＰ］を示すグラフである。
【図９】 実施の形態２に係わり、各圧縮機の運転容量の変化のさらに他の例を示し、必要運転容量［ＨＰ］に対する圧縮機運転容量［ＨＰ］を示すグラフである。
【図１０】 実施の形態２に係わる各圧縮機の運転容量の時間変化を示す説明図である。
【図１１】 実施の形態２に係わる各圧縮機の運転容量の時間変化を示す説明図である。
【図１２】 実施の形態２に係わる各圧縮機の運転容量の時間変化を示す説明図である。
【図１３】 本発明の参考の形態３による冷凍空調装置の構成を示す冷媒回路図である。
【図１４】 参考の形態３に係わり、運転容量制御間隔に対する｛高圧側を構成する機器および配管の容積（Ｌ）｝／運転容量変動幅［ＨＰ］を示すグラフである。
【図１５】 参考の形態３に係わり、運転容量制御間隔に対する｛低圧側を構成する機器および配管の容積（Ｌ）｝／運転容量変動幅［ＨＰ］を示すグラフである。
【図１６】 本発明の参考の形態４による冷凍空調装置の構成を示す冷媒回路図である。
【図１７】 参考の形態４による冷凍空調装置の他の構成を示す冷媒回路図である。
【図１８】 参考の形態４による冷凍空調装置のさらに他の構成を示す冷媒回路図である。
【図１９】 本発明の参考の形態５による冷凍空調装置の構成を示す冷媒回路図である。
【図２０】 参考の形態５による冷凍空調装置の他の構成を示す冷媒回路図である。
【図２１】 本発明の参考の形態６による冷凍空調装置の構成を示す冷媒回路図である。
【図２２】 参考の形態６による冷凍空調装置の他の構成を示す冷媒回路図である。
【図２３】 参考の形態６による冷凍空調装置のさらに他の構成を示す冷媒回路図である。
【図２４】 本発明の参考の形態７による冷凍空調装置の構成を示す冷媒回路図である。
【図２５】 参考の形態７に係わる制御弁の構造を示す断面図である。
【図２６】 参考の形態７による冷凍空調装置の他の構成を示す冷媒回路図である。
【図２７】 参考の形態７による冷凍空調装置のさらに他の構成を示す冷媒回路図である。
【図２８】 本発明の参考の形態８による冷凍空調装置の構成を示す冷媒回路図である。
【図２９】 参考の形態８による冷凍空調装置の他の構成を示す説明図であり、図２９（ａ）は室外機を正面から見た時の構成を示し、図２９（ｂ）は室外機を側面から見た時の構成を示す。
【図３０】 本発明の参考の形態９による冷凍空調装置に係わる制御弁を示す断面図である。
【図３１】 本発明の参考の形態１０による冷凍空調装置の構成を示す冷媒回路図である。
【図３２】 参考の形態１０に係わる冷凍空調装置の運転情報の測定方法を示す説明図である。
【図３３】 参考の形態１０に係わる冷凍空調装置の運転情報の他の測定方法を示す説明図である。
【図３４】 従来の空気調和機を示す冷媒回路図である。
【図３５】 従来の空気調和機に係り、時間的な電磁弁の開閉制御の様子を示す説明図である。
【符号の説明】
１ａ、１ｃ 段階的な容量で運転可能な圧縮機、１ｂ 一定容量の圧縮機、２ａ、２ｂ 吐出配管、３ａ、３ｂ 吸入配管、４ 冷媒流路切り換え手段、５ 第1熱交換器、６ 液管、７ 絞り手段、８ａ、８ｂ 第２熱交換器、９ ガス管、１０ａ、１０ｂ 制御弁、１６高圧側の冷媒容器、１７ 低圧側の冷媒容器、１８ オイルセパレータ、１９ 油戻し回路、３０ 液レシーバ、３１ アキュムレータ、３２、３３ 抵抗素子、３４ バイパス回路、３５ 制御弁、３６ 熱交換部、３７ 可動弁、３８ 弁座、３９ プランジャー、４０ コイル、４１ 弁入口側流路、４２ 弁出口側流路、４３ 冷却手段、４４ 室外機、４５ 機械室、４６ａ、４６ｂ 減速手段、４７ａ、４７ｂ 圧力測定手段、４８ａ、４８ｂ、４８ｃ、４８ｄ 温度測定手段。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refrigerating and air-conditioning apparatus using a compressor that is operated at a stepwise operating capacity and that switches the capacity step at a short cycle to realize a continuous operating capacity.
[0002]
[Prior art]
In conventional refrigeration and air-conditioning systems, inverters are used that continuously adjust the compressor rotation speed and continuously adjust the compressor operating capacity by changing the power supply frequency according to the load. This inverter achieves high-efficiency operation by appropriately controlling the operating capacity of the compressor. However, in recent years, it has become a problem that harmonics generated by using the inverter are on the power source and adversely affect other devices. As a countermeasure against harmonics in the case of using an inverter, it can be implemented by using an active filter that prevents the harmonics from coming out of the refrigeration air conditioner, but the cost is increased by the amount of the active filter.
[0003]
Therefore, several methods have been proposed in which the operation capacity of the compressor is continuously adjusted by mechanical control without using an inverter.
FIG. 34 is a refrigerant circuit diagram showing an air conditioner provided with a rotary compressor disclosed in, for example, Japanese Patent Laid-Open No. 62-126289. In the figure, reference numeral 51 denotes a compressor portion of the rotary compressor. The compressor unit 51 includes a roller 53 that is eccentrically rotatable in a cylinder 52 that is sandwiched between a main bearing and a sub-bearing (both not shown).
A blade 54 is provided in the cylinder 52, and a suction port 55 and a discharge port 56 are disposed on both sides of the blade 54. Between the intake port 55 and the discharge port 56 of the compressor unit 51, the indoor heat exchanger 8, the expansion valve 7, and the outdoor heat exchanger 5 are connected via the four-way valve 4, and a heat pump type air conditioner is installed. It is composed. In addition, 57 shows the refrigerant | coolant piping for connecting each refrigeration cycle component apparatus.
[0004]
On the other hand, the cylinder 52 of the compressor unit 51 is provided with a relief port 58 at a position facing the suction port 55 and the discharge port 56.
The relief port 58 is provided with a valve 59 for introducing the pressure switched by the high pressure side solenoid valve 10a and the low pressure side solenoid valve 10b from the pressure introduction pipe 60. Reference numeral 61 denotes a spring that applies a biasing force to the valve 59 on the open side.
[0005]
When the high pressure side solenoid valve 10a is opened and the low pressure side solenoid valve 10b is closed, the valve 59 is pushed down by the discharge pressure to close the relief port 58. When the relief port 58 is closed, the refrigerant in the middle of compression is not bypassed via the relief port 58, so the compressor unit 51 operates at the maximum capacity.
Conversely, when the high pressure side solenoid valve 10a is closed and the low pressure side solenoid valve 10b is opened, the valve 59 is pushed up by the spring 58 to open the relief port 58. When the relief port 58 is opened, gas refrigerant in the middle of compression is bypassed to the low pressure side via the relief port 58, so that the operating capacity in the compressor unit 51 is reduced and the operation with the minimum capacity is performed.
The opening and closing of the solenoid valves 10a and 10b is controlled by a control circuit (not shown), and the maximum capacity operation and the minimum capacity operation are switched in a short time by a control routine as shown in FIG. The intermediate capacity is variable in multiple stages.
[0006]
For example, when the control is performed as shown in FIG. 35, the operation is performed at the maximum capacity for 3 seconds and is operated at the minimum capacity for 2 seconds. Therefore, the average operation capacity for 5 seconds is (maximum capacity × 3 + minimum capacity × 2) / 5 By changing the length of the open / close time of the high-pressure side solenoid valve 10a and the low-pressure side solenoid valve 10b, operation at an intermediate capacity between the maximum capacity and the minimum capacity is continuously realized.
According to this method, by adjusting the operation time of the maximum capacity operation and the minimum capacity operation, it is possible to operate continuously with an intermediate capacity between the maximum capacity and the minimum capacity, and the operation capacity control equivalent to that of the inverter becomes possible. . In addition, since the inverter is not used in the operation capacity control of the compressor, an electric loss does not occur in the inverter portion, and a more efficient operation is possible.
[0007]
[Problems to be solved by the invention]
In the conventional refrigerating and air-conditioning apparatus as described above, since the operating capacity of the compressor that operates at a stepped capacity is largely switched between the maximum capacity and the minimum capacity, fluctuations in the refrigeration cycle such as pressure fluctuations occur. The maximum operating capacity and the minimum operating capacity required as a compressor are set based on the refrigerating and air-conditioning capacity of the refrigeration air-conditioning apparatus. For example, refrigeration with a maximum operating capacity of 10 horsepower (hereinafter referred to as HP) using conventional techniques is performed. In the case where the air conditioner is configured so that the capacity control can be continuously realized up to the operating capacity of 2HP, the compressor needs to have a maximum operating capacity of 10 HP and a minimum operating capacity of 2 HP. In this case, when an intermediate capacity between the maximum capacity and the minimum capacity is realized, the operation of switching the operation of the maximum operation capacity 10 HP and the minimum capacity 2 HP in a short time is performed. And a large pressure pulsation occurs on the refrigeration cycle. Refrigeration and air-conditioning equipment, such as the amount of heat exchange in the heat exchanger fluctuates greatly in a short time of several seconds as the pressure fluctuates, and when the air heat exchanger is used as the heat exchanger, the fluctuation of the blown air temperature increases. The refrigeration capacity and air-conditioning capacity in the factory greatly fluctuated in a short time, so there was a problem that the comfort was impaired.
[0008]
Further, in order to switch the operating capacity of the compressor in a short time, the number of times of switching between the high-pressure side solenoid valve 10a and the low-pressure side solenoid valve 10b is increased, and a large collision force is exerted on the contact portion in the solenoid valve during opening and closing. As a result, there is a problem that the reliability of driving the solenoid valve is lowered, for example, the life of the solenoid valve is shortened.
Further, in this case, since the electromagnetic valves 10a and 10b are driven in a short time, there is a problem that a driving sound generated when the electromagnetic valve is driven to open and close is frequently generated and noise is generated.
[0009]
In addition, because pressure fluctuations occur on the refrigeration cycle, when the operation control of the refrigeration cycle is performed by feedback control, the control is performed based on the changed operation information, so that stable control cannot be performed. was there.
[0010]
The present invention was made to solve the conventional problems as described above, and in a refrigeration air conditioner equipped with a compressor that can be operated with a stepped capacity, there is no adverse effect of harmonics by using an inverter, Suppressing the fluctuation range on the refrigeration cycle such as pressure fluctuation that occurs when switching the operating capacity of this compressor in a short cycle to realize continuous operating capacity, and fluctuations in refrigeration capacity and air conditioning capacity such as fluctuations in blown air temperature It is an object of the present invention to obtain a refrigeration air-conditioning apparatus that can ensure comfort during driving by reducing the size.
[0011]
Further, in the compressor that realizes a continuous operation capacity by switching the operation capacity of a compressor that can be operated with a stepwise capacity in a short cycle, when the operation capacity is switched by the control valve, the control valve is frequently used. The purpose is to obtain a refrigeration air conditioner that realizes a low-noise and long-life control valve and improves reliability by alleviating the impact of open / close drive and reducing drive noise and collision force is there.
[0012]
Another object of the present invention is to obtain a refrigeration air conditioner capable of performing stable operation control by performing control corresponding to the changed operation information.
[0013]
[Means for Solving the Problems]
The refrigerating and air-conditioning apparatus according to the present invention includes at least one compressor that can be operated at a stepped capacity, a compressor that can be operated at a stepped capacity separately from the compressor, or a compressor that operates at a constant capacity. At least one compressor, which can be operated at the stepwise capacity, is operated at a different stage capacity at each time allocated to the short-period time distribution, and the average over the short period is changed by changing the time distribution. The total operating capacity of the plurality of compressors is continuously variable by changing the capacity.
[0014]
The refrigerating and air-conditioning apparatus according to the present invention, when the operating capacity of a plurality of compressors is shared and operated by at least two compressors that can be operated with a stepped capacity, the compression that can be operated with the stepped capacity. The operating capacity shared by the machine is shared while avoiding the coincidence with the minimum capacity among the staged capacities of the compressor.
[0015]
The refrigerating and air-conditioning apparatus according to the present invention is configured so that at least two compressors that can be operated with stepped capacities are operated with capacities at different stages at each time allocated to a short-cycle time distribution. The temporal variation of the total operating capacity within the short cycle is smaller than the difference between the larger total operating capacity and the smaller total operating capacity of the compressors operating in the short cycle. As described above, the operation is performed by combining the short-cycle time distribution of the compressors and the operation capacity of each time.
[0016]
The refrigerating and air-conditioning apparatus according to the present invention includes two compressors that can be operated at a stepped capacity, and at least a part of the time during which one compressor operates at a larger capacity in that stage within a short period. At one time, the other compressor operates at the smaller capacity of the stage and at least part of the time at which the other compressor operates the larger capacity of the stage. The machine is designed to operate at the smaller capacity at that stage.
[0042]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Hereinafter, for example, an indoor air conditioning apparatus will be described as the refrigeration air conditioning apparatus according to Embodiment 1 of the present invention. FIG. 1 is a refrigerant circuit diagram showing a configuration of a refrigerating and air-conditioning apparatus according to the present embodiment. In the figure, 1a is a compressor that can be operated at a stepped capacity, for example, a scroll compressor provided with a bypass capacity control means, 1b is a compressor with a constant capacity, 2a and 2b are discharge pipes, and 3a and 3b are suction pipes. 4 is a refrigerant flow switching means for cooling operation and heating operation, for example, a four-way valve, 5 is a first heat exchanger, for example, an outdoor heat exchanger, 6 is a liquid pipe, 7a, 7b are throttle means, for example, an expansion valve, Reference numerals 8a and 8b are second heat exchangers, for example, indoor heat exchangers, and 9 is a gas pipe. These devices and piping are connected to circulate the refrigerant to constitute a refrigeration cycle.
[0043]
Reference numerals 10a and 10b are control valves for controlling the operating capacity of the scroll compressor 1a. Reference numeral 10a is a high-pressure side solenoid valve provided in the pipe 11a from the discharge pipe 2a, for example. 10b is a pipe 12a from the suction pipe 3a. It is a low-pressure side solenoid valve provided in. The pipes 13a and 14a from the solenoid valves 10a and 10b are joined and connected to the scroll compressor 1a via the capacity control pipe 15a of the scroll compressor 1a.
The maximum operating capacity of the refrigerating and air-conditioning apparatus in this embodiment is 10 HP, the compressor 1a is a compressor capable of stepwise capacity switching between the maximum capacity 6HP and the minimum capacity 2HP, and the compressor 1b is a constant capacity of 4HP. It is a compressor that operates at That is, two compressors are provided, and the compressor 1a having the maximum capacity 6HP and the compressor 1b having the maximum capacity 4HP constitute a refrigeration air conditioner having the maximum capacity 10HP. Here, for example, a cooling capacity of about 2.8 kW can be supplied with an operating capacity of 1 HP.
[0044]
Next, the flow of the refrigerant in the refrigeration cycle of the present embodiment will be described.
In the cooling operation, the flow path is set so that the four-way valve 4 flows in the direction of the solid line in FIG. The high-temperature and high-pressure gas refrigerant discharged from the compressors 1a and 1b is condensed and liquefied by the outdoor heat exchanger 5 through the discharge pipes 2a and 2b and the four-way valve 4, and then decompressed by the expansion valves 7a and 7b through the liquid pipe 6. As a result, it becomes a low-pressure two-phase refrigerant and flows into the indoor heat exchangers 8a and 8b. Furthermore, the low-pressure two-phase refrigerant cools the room by removing heat from the indoor side while evaporating and gasifying the indoor heat exchangers 8a and 8b. Thereafter, the refrigerant flows through the gas pipe 9, the four-way valve 4, and the suction pipes 3a and 3b and is sucked into the compressors 1a and 1b.
On the other hand, in the heating operation, the flow path is set so that the four-way valve 4 flows in the direction of the broken line in FIG. The high-temperature and high-pressure gas refrigerant discharged from the compressors 1a and 1b flows into the indoor heat exchangers 8a and 8b through the discharge pipes 2a and 2b, the four-way valve 4 and the gas pipe 9, and is condensed and liquefied. Heat is supplied to heat the room. Thereafter, the pressure is reduced by the expansion valves 7a and 7b to form a low-pressure two-phase refrigerant, which is evaporated and gasified by the outdoor heat exchanger 5 through the liquid pipe 6, and then circulated through the four-way valve 4 and the suction pipes 3a and 3b. Inhaled into the machine 1a, 1b.
[0045]
Next, the capacity control operation of the compressor 1a will be described. Here, the compressor 1a is a scroll compressor that can be operated in two stages of a maximum capacity (6HP) and a minimum capacity (2HP). When the compressor 1a is operated at the maximum capacity, the high-pressure side solenoid valve 10a is opened, The side solenoid valve 10b is closed. As a result, the capacity control pipe 15 communicates with the discharge pipe 2a and enters a high pressure state. Conversely, when the compressor 1a is operated at the minimum capacity, the high pressure side solenoid valve 10a is closed and the low pressure side solenoid valve 10b is opened. As a result, the capacity control pipe 15 communicates with the suction pipe 3a and enters a low pressure state.
[0046]
The operation of the scroll compressor at this time will be described with reference to FIGS. 2 is a cross-sectional view showing a compression chamber of the scroll compressor 1a, and FIG. 3 is a plan view as seen from a cross-section AA in FIG. In the figure, reference numeral 20 denotes a fixed scroll, which is provided with a spiral 20b on the lower surface of a base plate portion 20a, and an ejection port 20c is opened. Reference numeral 21 denotes an orbiting scroll. A spiral chamber 21b is combined on the upper surface of the base plate portion 21a to form a compression chamber 22. A rocking shaft 21c formed below the base plate of the rocking scroll is connected to a bearing portion eccentric to a rotating shaft (not shown) connected to an electric motor (not shown), and an anti-rotation member (not shown). Thus, a so-called oscillating motion that revolves while preventing rotation is performed. Therefore, the compression chamber 22 is formed by the fixed-side spiral 20b and the swing-side spiral 21b. As the low-pressure gas refrigerant flows from the outer side of the compression chamber 22, that is, from the outer periphery of the spirals 20b and 21b, and is conveyed to the center side, the volume is reduced and the pressure is increased, and the temperature increases from the discharge port 20c to the discharge pipe 27. It is sent out as a high-pressure gas refrigerant.
[0047]
The following mechanism is provided in the base plate part 20a of the fixed scroll 20 as a capacity control means. A pair of bypass holes 23a are provided in the compression chamber 22 from the outside of the spiral so as to be symmetrical with respect to the central portion, and communicate with a large-diameter valve seat hole 23b provided above.
An annular slit 23c concentric with the hole is provided in the bypass hole 23a, and a discharge port 23d communicating from the annular slit 23c to the outer low pressure portion is opened. A control valve 24 is in contact with the valve seat at the bottom of the valve seat hole 23b and closes the bypass hole 23a, and is given an upward pressing force by a compression spring 25 inserted into the annular slit 23c. Reference numeral 26 denotes a valve seat plug attached to the upper part of the valve seat hole 23b. The communication hole 26a is opened, and the pressure pipe 23 connected to the capacity control pipe 15a is coupled thereto.
[0048]
When high-pressure refrigerant is added to the pressure pipe 23 from the capacity control pipe 15a through the discharge pipe 2a and the low-pressure refrigerant from the suction pipe 3a is cut off, the control valve 24 is pressed downward to close the bypass hole 23a, The refrigerant gas in the compression chamber 22 is compressed without being bypassed and sent out from the discharge port 20c, and the compressor 1a operates at the maximum capacity.
[0049]
Next, when low-pressure refrigerant is added from the capacity control pipe 15a to the pressure pipe 23 through the suction pipe 3a and the high-pressure refrigerant from the discharge pipe 2a is cut off, the control valve 22 is controlled by the pressure in the compression chamber 22 and the compression spring 25. 24 is pushed up to contact the valve seat plug 26 and close the communication hole 26a. As a result, the bypass hole 23a and the discharge hole 23d communicate with each other, a part of the refrigerant gas in the compression chamber 22 is discharged to the low-pressure portion in the compressor, and the amount of refrigerant sent out from the discharge port 20c is reduced, whereby the compressor 1a. Operates with minimum capacity.
[0050]
In this way, in the compressor 1a that can be operated with the two-stage capacity of the maximum capacity and the minimum capacity, when the operation is performed with the capacity between the two stages, the maximum capacity operation and the minimum capacity operation are switched with a short period time distribution. Realize with. Furthermore, the total capacity of the compressors 1a and 1b can be continuously changed by changing the short-cycle time distribution of the maximum capacity operation and the minimum capacity operation to change the average capacity in the short period.
[0051]
Hereinafter, a method for controlling the operating capacity of the compressors 1a and 1b will be described. The total required operating capacity of the compressors 1a and 1b is determined by the operating state of the refrigeration air conditioner, the outside air temperature, the indoor air temperature, the target value of the indoor air temperature, the operating capacity of the indoor heat exchangers 8a and 8b, and the like.
For example, when determining the required operation capacity of the compressors 1a and 1b according to the operation state of the refrigeration air conditioner, the operation capacity is determined as follows. During the cooling operation, the low-pressure side pressure of the refrigeration cycle, for example, the pressure on the compressor suction side, is measured, and the low-pressure measurement value is compared with a predetermined low-pressure target value. As a result of this comparison, if the measured value is higher than the target value, the operating capacity is made larger than the current compressor operating capacity. Conversely, if the measured value is lower than the target value, the operating capacity is made higher than the current compressor operating capacity. Make it smaller. During heating operation, the high-pressure side pressure of the refrigeration cycle, for example, the pressure on the discharge side of the compressor is measured, and the high-pressure measurement value is compared with a predetermined high-pressure target value. The operating capacity is made smaller than the current compressor operating capacity, and conversely if the measured value is lower than the target value, the operating capacity is made larger than the current compressor operating capacity.
[0052]
When the required operating capacity of the compressors 1a and 1b is determined from the indoor air temperature and the indoor air temperature target value set by the refrigerating and air-conditioning system user using a remote controller or the like, the operating capacity is determined as follows. During the cooling operation, the indoor air temperature is measured, and the measured value is compared with the indoor air temperature target value. As a result of this comparison, if the measured value is higher than the target value, the operating capacity is made larger than the current compressor operating capacity. Conversely, if the measured value is lower than the target value, the operating capacity is made higher than the current compressor operating capacity. Make it smaller. Similarly, the indoor air temperature is measured during heating operation, and this measured value is compared with the indoor air temperature target value. If the measured value is higher than the target value, the operating capacity is made smaller than the current compressor operating capacity. On the contrary, if the measured value is lower than the target value, the operating capacity is made larger than the current compressor operating capacity.
[0053]
When the required operating capacity of the compressor is determined from the operating capacity of the indoor heat exchangers 8a and 8b, if the operating capacity of the indoor heat exchangers 8a and 8b is large, the load required for the refrigeration air conditioner is large. Therefore, the operating capacity of the compressor is increased. Conversely, if the operating capacity of the indoor heat exchangers 8a and 8b is small, the load required for the refrigeration air conditioner is reduced, so the operating capacity of the compressor is reduced.
[0054]
Also, the outside air temperature affects the load on the refrigeration air conditioner, and if the outside air temperature is low, the cooling load decreases and the heating load increases. During the heating operation, the required operating capacity of the compressor is adjusted by largely adjusting the operating capacity of the compressor.
[0055]
According to the required operating capacity of the compressor determined as described above, the high-pressure side solenoid valve 10a and the low-pressure side solenoid valve 10b of the compressor 1a are opened and closed in a short cycle, and the constant capacity compressor 1b is operated and stopped. The capacity control is implemented by combining the above. Table 1 shows the opening and closing of the high-pressure side solenoid valve 10a and the low-pressure side solenoid valve 10b of the compressor 1a and the operation and stoppage of the constant capacity compressor 1b when obtaining a total operating capacity of 2HP to 10HP. In the capacity control of the compressor 1a, for example, 10 seconds is one cycle, the maximum capacity operation (6HP) when the high pressure solenoid valve 10a is opened (low pressure solenoid valve 10b is closed), and the low pressure solenoid valve 10b is opened (high pressure). The time distribution with a short cycle of 10 seconds is distributed in two stages of the minimum capacity operation (2HP) when the solenoid valve 10a is closed.
[0056]
[Table 1]

[0057]
For example, when the total operating capacity in Table 1 is 3 HP, if the maximum capacity operation of 6 HP is 2.5 seconds and the minimum capacity operation of 2 HP is 7.5 seconds in the compressor 1 a as a short period time distribution, The average capacity is (6 × 2.5 + 2 × 7.5) / 10 = 3, and since the compressor 1b is stopped, 3HP is obtained as the total operating capacity. Further, when the total operating capacity is 9 HP, if the maximum capacity operation of 6 HP is 7.5 seconds and the minimum capacity operation of 2 HP is 2.5 seconds in the compressor 1a as a short period time distribution, the average capacity of the short period is Since (6 × 7.5 + 2 × 2.5) / 10 = 5 and the compressor 1b (4HP operating capacity) is operating, 9HP is obtained as the total operating capacity. In this way, the average capacity in the short cycle is changed by changing the short time distribution of the maximum capacity operation and the minimum capacity operation, and the total of the operation capacities of the compressors 1a and 1b is continuously and arbitrarily changed. Can do. Here, an operation in which the capacity is changed stepwise with a predetermined time distribution in a short cycle is referred to as a time control operation.
[0058]
In the operation of the high-pressure side solenoid valve 10a and the low-pressure side solenoid valve 10b in Table 1, as shown in FIG. 4, the opening / closing is controlled so that either one is always open and one is closed. FIG. 5 is a graph showing changes in the operating capacities of the compressors 1a and 1b, showing the compressor operating capacity [HP] with respect to the required operating capacity [HP], and the change in the total operating capacity of the compressor realized by Table 1 Is illustrated. By operating with the compressor capacity as shown in Table 1, in this embodiment, the overall operating capacity of the plurality of compressors 1a, 1b can be continuously changed from 2HP to 10HP.
[0059]
Looking at the fluctuation range of the operating capacity in a short cycle in this case, when the operating capacity is 6 HP to 10 HP, when the compressor 1 a is operating at the maximum capacity, the compressor 1 a and 1 b are operated at a total capacity of 10 HP. However, when the compressor 1a is operating at the minimum capacity, the compressor 1a and 1b are operated at a total capacity of 6HP. In other words, the operating capacity varies between 10 HP and 6 HP in a short period.
Therefore, even in an air conditioner that realizes a continuous operating capacity from 2 HP to 10 HP, when operating with one compressor as in the prior art, the operating capacity varies between 10 HP and 2 HP in a short cycle. In contrast, in the present embodiment, the fluctuation range of the operating capacity can be reduced.
If the fluctuation range of the operating capacity can be reduced, the pressure pulsation generated on the refrigeration cycle will be reduced, the fluctuation range of the heat exchange amount in the heat exchanger, and the air temperature when the air heat exchanger is used as the heat exchanger Variations in the refrigeration capacity and air conditioning capacity of the refrigeration air conditioner, such as the fluctuation range, can be reduced, and comfort during operation of the refrigeration air conditioner can be secured.
[0060]
When the operating capacity is 2HP to 6HP, the operating capacity varies between 2HP and 6HP in a short period. In this case as well, when operating with a single compressor as in the prior art, the operating capacity fluctuates between 10 HP and 2 HP in a short time, whereas in this embodiment, the operating capacity fluctuation range can be reduced.
In this case as well, the fluctuation range of the operating capacity can be reduced, the pressure pulsation width generated on the refrigeration cycle, the fluctuation range of the heat exchange amount in the heat exchanger, and the air temperature when the air heat exchanger is used as the heat exchanger The fluctuation range of the refrigeration air conditioner can be reduced, and the fluctuations in the refrigeration capacity and the air conditioning capacity of the refrigeration air conditioner can be reduced.
[0061]
As described above, in the present embodiment, the compressor 1a that can be operated at a stepped capacity and the compressor 1b that is operated at a constant capacity are provided, and the inverter is used by operating without using the inverter. There is no adverse effect of harmonics, and the capacity fluctuation range when switching the operation capacity of the compressor 1a in a short cycle to realize a continuous operation capacity is reduced, and the pressure fluctuations and the like caused by this change on the refrigeration cycle The fluctuation range can be suppressed. For this reason, it is possible to obtain a refrigerating and air-conditioning apparatus that can reduce fluctuations in refrigeration capacity and air-conditioning capacity such as fluctuations in blown air temperature and can ensure comfort during operation.
[0062]
In Table 1, the operating capacity switching cycle is performed at 10-second intervals (the total operating time of the maximum capacity and the operating time of the minimum capacity). This period is applied to the pressure fluctuation range and the heat exchanger. It is determined by the fluctuation range of the blown air temperature when an air heat exchanger is used. For example, if an air heat exchanger is used as the heat exchanger in order to ensure comfort during operation of the refrigeration air conditioner, the pressure fluctuation range of the refrigeration cycle when the fluctuation range of the blown air temperature is suppressed to about 1 ° C. Is 2kgf / cm at high pressure ² 1kgf / cm at low pressure ² It is necessary to set it below the degree. The operating capacity switching interval to keep this pressure fluctuation range changes depending on the stepwise operating capacity fluctuation width within the short cycle, that is, the difference between the maximum capacity and the minimum capacity, but in general refrigeration cycles, it takes about several seconds. It is set at intervals of several tens of seconds.
[0063]
In the above description, the compressor 1a is a compressor that can be operated with a maximum capacity and a minimum capacity of two stages. However, the compressor is not limited to two stages, and a compressor that can be operated with more stages of capacity. If it is used, the operation pattern becomes more complicated and the operation control becomes complicated, but the difference in the operation capacity to be switched by the short period time distribution can be reduced, the pressure fluctuation of the refrigeration cycle can be further reduced, and the comfort when operating the refrigeration air conditioner Will rise. In order to obtain two or more stages of operation capacity in the scroll compressor shown in FIG. 2 and FIG. 3, for example, another compression chamber 22 communicating with the low-pressure pipe is connected to the compression chamber 22 outside the bypass hole 23a realizing the minimum capacity. This can be realized by providing a bypass hole and changing the amount of refrigerant gas in the compression chamber 22 by closing and opening the hole.
[0064]
In the above description, a combination of one compressor capable of operating at a stepped capacity and one compressor having a constant capacity has been described. However, a compressor capable of operating at a stepped capacity and a compressor having a constant capacity are provided. When multiple units are combined, multiple compressors that can be operated with stepwise capacity and one compressor with a fixed capacity are combined. When a plurality of units are combined, the same effect can be obtained in any case.
In addition, in terms of the effect of reducing the pressure fluctuation of the refrigeration cycle, the capacity difference to be switched in a short cycle is smaller when the compressor has a larger number of capacity stages that can be operated with a stepped capacity. Because it can, it is effective. In addition, a larger number of compressors is more effective because the difference in capacity to be switched in a short cycle can be made smaller than a smaller number of compressors.
[0065]
Embodiment 2. FIG.
Hereinafter, for example, an indoor air conditioning apparatus will be described as a refrigeration air conditioning apparatus according to Embodiment 2 of the present invention. FIG. 6 is a refrigerant circuit diagram showing the configuration of the refrigerating and air-conditioning apparatus according to this embodiment. In the figure, 1c is a compressor that can be operated at a stepped capacity, for example, a scroll compressor provided with a bypass capacity control means, 10c and 10d are control valves for controlling the operating capacity of the scroll compressor 1c, and 10c Is a high pressure side solenoid valve provided on the pipe 11b from the discharge pipe 2b, for example, and 10d is a low pressure side solenoid valve provided on the pipe 12b from the suction pipe 3b, for example. The pipes 13b and 14b from the solenoid valves 10c and 10d are joined and connected to the scroll compressor 1c via the capacity control pipe 15b of the scroll compressor 1c.
The maximum operating capacity of the refrigerating and air-conditioning apparatus in this embodiment is 10 HP, the compressor 1a is a compressor capable of stepwise capacity switching between the maximum capacity 6HP and the minimum capacity 4HP, and the compressor 1c has a maximum capacity 4HP. This is a compressor capable of stepwise capacity switching with a minimum capacity of 2 HP. That is, two compressors that can be operated at a stepwise capacity are provided, and the compressor 1a with the maximum capacity 6HP and the compressor 1c with the maximum capacity 4HP constitute a refrigeration air conditioner with a maximum capacity 10HP.
The other elements in FIG. 6, the refrigerant flow, and the method for switching the compressor capacity in FIG. 6 are the same as those in the first embodiment, and thus the description thereof is omitted.
[0066]
In the present embodiment, the required operating capacity of the compressor is the same as that of the first embodiment, and the operating state of the refrigeration air conditioner, the outside air temperature, the indoor air temperature, the target value of the indoor air temperature, the indoor heat exchanger 8a, It is determined by the operating capacity of 8b. And according to the determined required operating capacity of the compressor, the high-pressure side solenoid valves 10a, 10c and the low-pressure side solenoid valves 10b, 10d of the compressors 1a, 1c are opened and closed in a short cycle, and the compressors 1a, 1c Capacity control is performed by combining operation and stop. Table 2 shows the opening and closing, operation, and stop of the high-pressure side solenoid valve 10a and the low-pressure side solenoid valve 10b of the compressor 1a when obtaining the total operating capacity 2HP to 10HP, and the high-pressure side solenoid valve 10c and the low-pressure side solenoid of the compressor 1c. The opening / closing, operation, and stop of the valve 10d are shown. In the capacity control of each of the compressors 1a and 1c, similarly to the first embodiment, for example, 10 seconds is set as one cycle, and the high-pressure side solenoid valves 10a and 10c are opened (low-pressure side solenoid valves 10b and 10d are closed). The maximum capacity operation (6HP, 4HP) at the time and the minimum capacity operation (4HP, 2HP) when the low pressure side solenoid valves 10b, 10d are opened (the high pressure side solenoid valves 10a, 10c are closed) are 10 seconds. Distributes short-period time allocation. By changing the time distribution to change the average capacity in a short cycle, the total operating capacity of the compressors 1a and 1c can be continuously and arbitrarily changed.
[0067]
[Table 2]

[0068]
In the operation of the high pressure side solenoid valves 10a and 10c and the low pressure side solenoid valves 10b and 10d in Table 2, as shown in FIG. 4, the opening and closing is controlled so that either one is always open and one is closed. . FIG. 7 is a graph showing changes in the operating capacities of the compressors 1a and 1c, showing the compressor operating capacity [HP] with respect to the required operating capacity [HP]. The total operating capacity of the compressor realized by Table 2 is shown in FIG. The change is illustrated.
[0069]
Looking at the fluctuation range of the operating capacity in a short time in this case, when the operating capacity is 8 HP to 10 HP, when the compressor 1 a is operating at the maximum capacity, the compressor 1 a and 1 c are operated at a capacity of 10 HP in total. However, when the compressor 1a is operating at the minimum capacity, the compressor 1a and 1c are operated at a total capacity of 8 HP. That is, the operating capacity fluctuates between 10 HP and 8 HP in a short period.
For other operating capacities, when the operating capacities are 6HP to 8HP, the operating capacities vary between 8HP and 6HP in a short time, and when the operating capacities are 4HP to 6HP, the operating capacities vary between 4HP and 6HP in a short time. When the operating capacity is 2HP to 4HP, the operating capacity varies between 2HP and 4HP in a short time.
Accordingly, the operation capacity of the plurality of compressors 1a and 1c as a whole can be continuously realized from 2HP to 10HP, and when this is realized, an inverter is not used and the operation is performed with one compressor as in the prior art. In this case, the operating capacity fluctuates between 10 HP and 2 HP in a short period, whereas the operating capacity fluctuation range can be reduced. Compared to the first embodiment, an operation with a small fluctuation range of the operation capacity can be performed.
[0070]
As described above, in the present embodiment, the compressors 1a and 1c that can be operated with two stepped capacities are provided, and the operation without using the inverter has an adverse effect of harmonics caused by using the inverter. In addition, the capacity fluctuation width when the operation capacity of the compressors 1a and 1c is switched in a short cycle to realize a continuous operation capacity is reduced, and the fluctuation width on the refrigeration cycle such as pressure fluctuation caused thereby is reduced. Can be suppressed. For this reason, it is possible to obtain a refrigerating and air-conditioning apparatus that can reduce fluctuations in refrigeration capacity and air-conditioning capacity such as fluctuations in blown air temperature and can ensure comfort during operation.
[0071]
Here, the combination shown in Table 2 and FIG. 7 is not the only combination in which the operating capacity is continuously changed between 2 HP and 10 HP by the two compressors 1 a and 1 c that can be operated with stepwise capacity. In the control in Table 2, as can be seen from FIG. 7, in the range of the operating capacity of 6HP to 10HP, the time control operation of the compressor 1a is performed at 8HP to 10HP, and the compressor 1c is operated at 6HP to 8HP. Although the time control operation is performed, as shown in FIG. 8, the time control operation of the compressor 1c is performed in the range of 8HP to 10HP, and the time control operation of the compressor 1a is performed in the range of 6HP to 8HP. You may go.
[0072]
Moreover, as shown in FIG. 9, you may perform the capacity | capacitance control method of performing time control driving | operation with compressor 1a, 1c in the range of 6HP-10HP. Table 3 shows the capacity control of the compressors 1a and 1c at this time. When a plurality of compressors that can be operated at a plurality of stepped capacities are provided, each compressor is controlled so as to avoid operating at the minimum capacity of that stage throughout a short period. For this reason, when the operating capacity is larger than the sum (6HP) of the smaller capacities of the compressors 1a and 1b and smaller than the sum (10HP) of the larger capacities, the two compressors 1a and 1c In both cases, time-controlled operation is performed. When the total operating capacity is 4 HP, there are two ways of operating at the minimum capacity with the compressor 1a and operating at the maximum capacity with the compressor 1b, but avoiding the minimum capacity operation with the compressor 1a, the compressor 1b Perform maximum capacity operation at.
[0073]
[Table 3]

[0074]
In the compressor provided with the bypass capacity control means, when performing the minimum capacity operation, the discharge temperature of the compressor rises due to the influence of the bypass as compared with the case of performing the maximum capacity operation. Therefore, as shown in FIG. 7 and FIG. 8, the minimum capacity operation is performed with one compressor 1a and the maximum capacity operation is performed with another compressor 1c as in the case of the operating capacity 8HP. The discharge temperature of the capacity-operated compressor 1a rises as compared to the maximum capacity-operated compressor 1c. In this case, the discharge temperature is detected as protection for the compressor, and when the discharge temperature rises above a certain temperature, control is performed to stop the compressor, and only the discharge temperature of the compressor 1a with the minimum capacity operation is stopped by protection. Stable operation occurs and stable operation cannot be performed.
Therefore, as shown in FIG. 9 and Table 3, the compressors 1a and 1b are time-controlled in the range from 6HP to 10HP, and the discharge temperatures of both compressors are set to the same temperature, thereby operating the compressor. If protection is performed by detecting the discharge temperature, both compressors can be stopped at the same time if an operation situation that requires operation protection occurs, otherwise operation of both compressors can be continued. Since it can be performed, stable operation can be performed.
However, this is not the case when an operating capacity value cannot be obtained unless a certain compressor is operated at the minimum capacity among a plurality of stages, for example, when the total operating capacity in Table 3 is 2HP.
[0075]
In this way, in the case of a refrigeration air conditioner equipped with a plurality of compressors that can be operated with a stepped capacity, when the operation capacity of the plurality of compressors is shared by the compressors that can be operated with a stepped capacity. Since the operating capacity shared by the compressor is shared by avoiding the coincidence with the minimum capacity among the staged capacities of the compressor, the discharge temperature of the operating compressor can be made equal. It is possible to prevent the discharge temperature of the compressor from rising.
The operating capacity 0HP is possible as the operating capacity stage of the compressor 1a that can be operated with a stepped capacity, but since it does not operate at 0HP, the discharge temperature does not increase, so the above-mentioned problems are Does not happen. For this reason, it is not regarded as the minimum capacity here. That is, the minimum capacity is the minimum capacity among the stepped capacities larger than 0HP.
Moreover, not only the operation that avoids the minimum capacity of a compressor that can be operated with a stepwise capacity is to be avoided as much as possible, but there are a plurality of combinations in which a plurality of compressors share the operation capacity when realizing a certain operation capacity. In some cases, it is preferable to select a combination that can reduce variation in the discharge temperature of the compressor that operates. When operating with an operating capacity that is greater than the sum of the minimum capacities of each compressor capacity stage and less than the sum of the maximum capacities, it is possible to operate multiple compressors in a time-controlled manner. An increase in the temperature of the refrigerant discharged from the compressor can be prevented, and a stable operation can be performed.
[0076]
FIGS. 10 and 11 are explanatory diagrams showing temporal changes in the operating capacity of each compressor according to the present embodiment, where time is shown in the horizontal direction and compressor operating capacity is shown in the vertical direction. In the time control operation when the operation capacity control as shown in FIG. 9 is performed, as shown in FIG. 10, the operation with the large capacity and the operation with the small capacity of the compressors 1a and 1c are performed at the same timing. The capacity fluctuates in a short period (large capacity of the compressor 1a + large capacity of the compressor 1c = 10 HP) and (small capacity of the compressor 1a + small capacity of the compressor 1c = 6 HP). On the other hand, as shown in FIG. 11, when the compressor 1a, 1c is operated at a large capacity and the small capacity is operated at the opposite timing (reverse phase), the fluctuation of the operating capacity in a short cycle is ( The compressor 1a has a large capacity + a small capacity of the compressor 1c = 8HP) and (a small capacity of the compressor 1a + a large capacity of the compressor 1c = 8HP). . Therefore, when performing time control operation by controlling the capacity of both the compressors 1a and 1c, the time for operating the compressors 1a and 1c at the opposite timing (reverse phase) of operation with the large capacity and the small capacity of the compressors 1a and 1c as much as possible. By operating so as to be longer, the fluctuation range of the total operation capacity of the compressors 1a and 1c can be reduced, and comfort during operation of the refrigeration air conditioner can be ensured.
[0077]
In the above, time control operation is performed with two compressors, and stepwise capacity operation is performed at opposite timings. However, when time control operation is performed with three or more units, timings opposite to each other are performed. Therefore, it becomes difficult to operate with a stepped capacity. In this case, it is preferable to combine the changes in the short cycle capacity operation of each compressor so that the total temporal fluctuation of the operation capacity of each compressor in the short cycle becomes small. For example, when the compressor A is performing capacity change operation of 4HP and 2HP, the compressor B is 4HP and 2HP, and the compressor C is 3HP and 2HP within a short cycle, the compressor A is 4HP, When the compressor B is operated at a capacity of 2 HP and the compressor C is operated at a capacity of 3 HP, the total operation capacity is 9 HP. On the other side of the time distribution, the capacity of the compressor A is 2 HP, the compressor B is 4 HP, the capacity of the compressor C is 2 HP. When the operation is performed, the total operation capacity is 8 HP, and the capacity fluctuation in a short cycle can be operated so as to be suppressed as small as 9 HP−8 HP = 1 HP. Of course, the time distribution is different for each compressor, and the capacity fluctuation can be minimized as long as the operation time is as long as possible at this timing as in the case of two units.
[0078]
Of course, it is preferable to minimize the total temporal fluctuation of the operating capacity of each compressor within a short period as in the above specific example, because the pressure fluctuation is small, but it is not limited to minimizing, It is good to combine so that the temporal variation of the total operating capacity of each compressor is slightly reduced.
That is, when each of the plurality of compressors is operated in time control, the combination having the largest temporal variation within the short cycle of the total operation capacity of each compressor is large for all the compressors within the short cycle. This is when operation is performed with the smaller capacity and all compressors are switched to the smaller capacity at the same time. At this time, the change in capacity in a short cycle is the difference between the sum of the larger capacity and the sum of the smaller capacity. Therefore, in the present embodiment, the temporal fluctuation within the short cycle of the total operation capacity of each compressor is the sum of the larger operation capacity and the smaller operation of each compressor operating in the short cycle. The compressor is operated in combination with the short-cycle time allocation of each compressor and the operating capacity at each time so as to be smaller than the difference from the total capacity. By operating in this way, the temporal fluctuation range of the operating capacity is reduced to some extent, so that the pressure fluctuation due to the time-controlled operation can be suppressed and the comfort during the operation of the refrigeration air conditioner can be ensured.
[0079]
Further, in the case where two compressors 1a and 1c that can be operated at a stepwise capacity as in the present embodiment are provided, one compressor has a larger capacity at that stage in a short cycle. At least a portion of the time during which the other compressor operates at the lower capacity of the stage and at least the time during which the other compressor operates at the larger capacity of the stage. When one compressor is operated so as to operate with the smaller capacity of the stage at some time, the state in which both of the two compressors 1a and 1c are operated with a large capacity is long in a short cycle. The pressure fluctuation can be made smaller than the time overlap.
[0080]
FIG. 12 shows the state of the short period time distribution. In FIG. 10, the operation with a large capacity and the operation with a small capacity of the compressors 1a and 1c are performed at the same timing, but in FIG. 12, this timing is shifted in the time direction. For this reason, when looking at the operating capacity, at T1 in the short cycle, the other compressor 1c is small during at least a part of the time during which the one compressor 1a operates the larger capacity (6HP). The capacity (2HP) is operated. At the same time, at T2 in the short cycle, at least a part of the time during which the other compressor 1c operates the larger capacity (4HP), one compressor 1a has the smaller capacity (4HP). Do the driving. Thereby, the fluctuation | variation of an operating capacity will be 8HP-10HP-8HP-6HP. If operated in this way, the temporal fluctuation range of the operating capacity is reduced to some extent as compared with the operation as shown in FIG. 10, so that pressure fluctuation due to the time control operation is suppressed, and the comfort during the operation of the refrigeration air conditioner is improved. It can be secured.
[0081]
Further, in the present embodiment, the description has basically been given of the case where the configuration includes two compressors that can be operated at a stepped capacity, but three or more compressors that can be operated at a stepped capacity are used. In some cases, similar effects can be obtained.
Speaking from the effect of reducing pressure fluctuations in the refrigeration cycle, it is possible to reduce the capacity difference to be switched in a short cycle by providing a larger number of compressor capacity stages that can be operated with stepped capacity than with a smaller number of capacity stages. Is effective. In addition, a larger number of compressors is more effective because the difference in capacity to be switched in a short cycle can be made smaller than a smaller number of compressors.
[0082]
In the first and second embodiments, the compressors 1a and 1c are described as scroll compressors provided with bypass capacity control means. However, the rotary compressors described in the prior art as the compressors 1a and 1c are described. The same effect can be obtained even if is used.
Moreover, you may change the rotation speed of a compressor in steps with a short cycle by the pole change of a motor. Further, even when a reciprocating compressor is used as the compressors 1a and 1c and the number of cylinders to be operated is changed stepwise in a short cycle, the same effects as those of the above embodiments can be obtained.
[0083]
Reference form 3.
Hereinafter, for example, a room air conditioning apparatus will be described as a refrigeration air conditioning apparatus according to Embodiment 3 of the present invention. Figure 13 shows a book reference It is a refrigerant circuit figure which shows the structure of the refrigerating and air-conditioning apparatus by the form. In the figure, 16 is a refrigerant container provided on the high-pressure side of the refrigeration cycle, and 17 is a refrigerant container provided on the low-pressure side of the refrigeration cycle. The other elements in FIG. 13, the refrigerant flow, and the compressor capacity switching method in FIG. 13 are the same as those in the first embodiment.
[0084]
Book reference In this embodiment, at least one compressor 1a that can be operated with a stepped capacity is provided. further reference As in the first embodiment, at least one compressor 1b having a constant capacity is provided, and a time control operation is performed in which the compressor 1a is operated at different stages of capacity at each time allocated to a short-cycle time distribution. And the average capacity | capacitance can be changed by changing the time distribution of a short period, and the operating capacity can be changed arbitrarily continuously as the whole several compressor 1a, 1b. By performing capacity control in this way, the compressors 1a and 1b can be operated at a continuous capacity without using an inverter that adversely affects other devices due to harmonics.
In this time-controlled operation of the compressor 1a, the pressure pulsation width generated on the refrigeration cycle, the fluctuation range of the heat exchange amount in the heat exchanger, and the fluctuation of the blown air temperature when the air heat exchanger is used as the heat exchanger And the like are caused by the stepwise switching of the operation capacity in the compressor 1a, and are caused by a change in the flow rate of the refrigerant sucked or discharged into the compressor 1a.
[0085]
Here, let us first focus on the high-pressure side in terms of fluctuations. Considering the high-pressure side of the refrigeration cycle as one container, the refrigerant discharged from the compressors 1a and 1b is considered to flow into the high-pressure side container. When the operating capacity of the compressor 1a increases and the refrigerant flow rate discharged from the compressor 1a increases, the refrigerant flow rate flowing into the high-pressure side container increases. At this time, since the amount of refrigerant present in the high-pressure side container increases, the density of the refrigerant in the container also increases and the pressure in the container rises. Conversely, when the operating capacity of the compressor 1a decreases and the flow rate of refrigerant discharged from the compressor 1a decreases, the flow rate of refrigerant flowing into the high-pressure side container decreases. At this time, since the amount of refrigerant existing in the high-pressure side container decreases, the density of the refrigerant in the container also decreases, and the pressure in the container decreases.
[0086]
The situation of the occurrence of fluctuations on the low pressure side can be grasped in the same manner, and the low pressure side of the refrigeration cycle is regarded as one container, and the refrigerant sucked into the compressors 1a and 1b is considered to have flowed out of the low pressure side container. When the operating capacity of the compressor 1a increases and the flow rate of refrigerant sucked into the compressor 1a increases, the flow rate of refrigerant flowing out of the low-pressure side container increases. At this time, since the amount of refrigerant existing in the low-pressure side container decreases, the density of the refrigerant in the container also decreases, and the pressure in the container also decreases. Conversely, when the operating capacity of the compressor 1a decreases and the flow rate of refrigerant sucked into the compressor 1a decreases, the flow rate of refrigerant flowing out of the low pressure side container decreases. At this time, since the amount of refrigerant present in the low-pressure side container increases, the density of the refrigerant in the container also increases, and the pressure in the container increases.
[0087]
In this way, the pressure fluctuation is caused by the fluctuation of the refrigerant amount in the container causing the fluctuation of the density of the refrigerant in the container. Therefore, focusing on the fact that the density of the refrigerant in the container can be expressed by the amount of refrigerant in the container / the volume of the container, even if the amount of refrigerant in the container varies, if the volume of the container is large, the density of the refrigerant in the container It can be seen that the fluctuation range can be reduced.
Book reference In the embodiment, based on the above-described phenomenon, the high-pressure side refrigerant container 16 or the low-pressure side refrigerant container 17 or both are provided, so that the volume on the high-pressure side of the refrigeration cycle is equal to or greater than the first predetermined volume. Or, the volume on the low pressure side is set to be equal to or larger than the second predetermined volume.
[0088]
Next, the volumes of the high pressure side container 16 and the low pressure side container 17 will be described. High-pressure side or low-pressure side container volume [L], operation capacity fluctuation width in time control operation [HP], pressure fluctuation width generated on refrigeration cycle [kg / cm ² ], The four parameters of the short cycle length [sec] in the time control operation are related to each other. For example, when determining the volume of the low-pressure side or high-pressure side container when designing the refrigeration air conditioner, If the values of the other three parameters are determined, the volume can be determined. However, the equipment constituting the high-pressure side container is the compressor discharge pipes 2a, 2b-high-pressure side container 16-four-way valve 4-condenser (the outdoor heat exchanger 5 in the cooling operation, and the indoor heat exchanger in the heating operation. 8a, 8b) -Each device of the expansion valves 7a, 7b and piping connecting them. On the other hand, the equipment constituting the low-pressure side container is the expansion valves 7a, 7b-evaporator (the indoor heat exchangers 8a, 8b in the cooling operation and the outdoor heat exchanger 5 in the heating operation) -four-way valve 4-low pressure side container 17-Compressor suction pipes 3a and 3b, and pipes connecting them. As described in the first embodiment, the length [sec] of the short cycle in the time control operation is determined by the pressure fluctuation range, the fluctuation range of the blown air temperature when the air heat exchanger is used as the heat exchanger, and the like. It is done. For example, if an air heat exchanger is used as the heat exchanger in order to ensure comfort during operation of the refrigeration air conditioner, the pressure fluctuation range of the refrigeration cycle when the fluctuation range of the blown air temperature is suppressed to about 1 ° C. Is 2kgf / cm at high pressure ² 1kgf / cm at low pressure ² It is necessary to set it below the degree. The length [sec] of the short cycle for suppressing the pressure fluctuation range varies depending on the operation capacity fluctuation width [HP] in the time control operation, but is set to an interval of several seconds to several tens of seconds in a general refrigeration cycle. Is done. In addition, the operating capacity fluctuation range [HP] in the time-controlled operation is set such that the minimum capacity is 0.3 HP or more, the maximum capacity is about 2 to 3 times the minimum capacity, and 1 / of the variable width (maximum capacity-minimum capacity). Set 10 to 1 times.
In addition, the volume of each equipment and piping necessary for constituting the refrigeration air conditioner can be calculated or estimated in advance, and the volume of the high-pressure side container 16 or the low-pressure side container 17 is determined by the other three parameters among the above four parameters. What is necessary is just to set it as the volume which deducted the volume of each minimum required apparatus and piping from the volume of the container of the low voltage | pressure side or the high voltage | pressure side determined by determining a parameter.
Here, the method of determining the volume by determining parameters other than the volume among the four parameters has been described. However, the present invention is not limited to this, and values of at least three parameters of the four parameters are set. If it is determined, the remaining one can be determined. If it is used when designing a refrigerating and air-conditioning apparatus, it is effective to obtain a highly comfortable apparatus.
[0089]
A procedure for actually determining the volumes of the high-pressure side container 16 and the low-pressure side container 17 will be described. In FIG. 14, the horizontal axis indicates the operation capacity control interval which is the length of the short cycle in the time control operation, and the vertical axis indicates {the volume of the equipment constituting the high-pressure side and the pipe capacity (L)} / the operation capacity fluctuation range [ HP], FIG. 15 shows the operation capacity control interval, which is the length of the short cycle in the time control operation, on the horizontal axis, and {the volume of the equipment and pipes constituting the low pressure side (L)} on the vertical axis. / It is a graph which shows the operating capacity fluctuation range [HP]. And the curve on the graph shows that the pressure fluctuation width of the refrigeration cycle is 1 kg / cm in FIG. ² 2kg / cm ² 3kg / cm ² In FIG. 15, the pressure fluctuation width of the refrigeration cycle is 0.5 kg / cm, respectively. ² 1kg / cm ² 2kg / cm ² Represents.
[0090]
The relationship between FIG. 14 and FIG. 15 is obtained by simulation. Based on this relationship, a method for obtaining the volume of the low-pressure side or high-pressure side container necessary for setting the operating capacity control interval and the pressure fluctuation range to a certain value or less will be described.
As described above, in order to ensure comfort during operation of the refrigerating and air-conditioning apparatus, if the fluctuation range of the blown air temperature when the air heat exchanger is used as the heat exchanger is suppressed to about 1 ° C., Pressure fluctuation range is 2kgf / cm at high pressure ² 1kgf / cm at low pressure ² It is necessary to set it below the degree.
[0091]
Therefore, the pressure fluctuation width of the high pressure is 2 kgf / cm. ² When the operating capacity control interval is 10 seconds, the high-pressure side volume [L] / operating capacity fluctuation range [HP] = 4 from FIG. 14, so that the operating capacity fluctuation range of the compressor is 2 HP. Then, the required high-pressure side volume is 8L. This value is the first predetermined volume. Therefore, the capacity of the high-pressure side container 16 is set in consideration of the volume of each device and the pipe constituting the high-pressure side so that the volume on the high-pressure side is 8L or more.
Similarly, the pressure fluctuation width of the low pressure is 1 kgf / cm. ² If the operating capacity control interval is 10 seconds, the low-pressure side volume [L] / operating capacity fluctuation range [HP] = 12.5 as shown in FIG. If the width is 2HP, the required low pressure side volume is 25L. This value is the second predetermined volume. Therefore, the capacity of the low-pressure side container 17 is set in consideration of the volume of each device and piping constituting the low-pressure side so that the volume on the low-pressure side becomes 25L or more.
[0092]
As described above, the first predetermined volume or the second predetermined volume is set to the allowable value of the pressure fluctuation range on the high pressure side or the low pressure side generated in the refrigeration cycle by the operation of the compressor, the length of the short cycle, and the short cycle. By determining based on the operating capacity fluctuation range of the compressor, the volume on the high-pressure side or the low-pressure side can be set so as to satisfy the operating conditions, the configuration of the equipment, and the comfort when using the apparatus. Further, by providing the containers 16 and 17 on the high-pressure side or the low-pressure side, even if the operation capacity of the compressor changes, the change in the density of the refrigerant can be reduced, and the pressure change accompanying the change in the operation capacity of the compressor. This reduces the fluctuation range on the refrigeration cycle, reduces fluctuations in the refrigeration capacity and air conditioning capacity, such as fluctuations in the blown air temperature, and has an effect of ensuring comfort during operation of the refrigeration air conditioner.
[0093]
In FIG. 13, the high-pressure side container 16 is provided on the compressor discharge side and the low-pressure side container 17 is provided on the compressor suction side. However, the installation location is not limited to this, and the high-pressure side container 16 includes the compressors 1a and 1b. The high pressure portion of the refrigeration cycle from the discharge port of the compressor until the pressure is reduced by the expansion valve 7, and the portion of the low pressure side container 17 from the pressure reduced by the expansion valve 7 to the suction to the compressors 1 a and 1 b However, the same effect can be obtained.
[0094]
Further, here, the volume on both the high-pressure side and the low-pressure side is configured to be equal to or greater than a predetermined value. However, if at least one volume is configured to be equal to or greater than the predetermined value, there is a difference in degree. There is an effect.
[0095]
Further, in order to suppress pressure fluctuation, not only the configuration in which the containers 16 and 17 are provided, but the respective volumes on the high-pressure side or the low-pressure side may be increased. For example, the pipe diameter of the extension pipe connecting the outdoor unit and the indoor unit may be increased, the pipe length may be increased, or the pipe of the pipe connecting the compressors 1a, 1b and the outdoor heat exchanger 5 The diameter may be increased or the pipe length may be increased. Moreover, you may enlarge the diameter of the heat exchanger tube used for indoor heat exchanger 8a, 8b or the outdoor heat exchanger 5, or may lengthen the length of a heat exchanger tube. In any configuration, the volume of each of the high pressure side and the low pressure side can be increased.
[0096]
As above, the book reference Even in this form, by operating without using an inverter, there is no adverse effect of harmonics caused by using the inverter.
Furthermore, the compressor 1b is provided separately from the compressor 1a that can be operated at a stepwise capacity, and the capacity fluctuation range in the time control operation can be reduced. Furthermore, by setting the total amount of the internal volume of at least one of the high-pressure side and the low-pressure side of the refrigeration cycle to a predetermined value or more so as to reduce the pressure fluctuation range of the refrigeration cycle, the compressor can be operated with a stepwise capacity. In 1a, the pressure pulsation width generated on the refrigeration cycle due to the capacity fluctuation when the time control operation is performed, the fluctuation width of the heat exchange amount in the heat exchanger, the blowout when the air heat exchanger is used as the heat exchanger The fluctuation range of the air temperature can be reduced. For this reason, the fluctuation | variation of the refrigerating capacity or air-conditioning capacity in a refrigerating air conditioning apparatus can be made small, and the refrigerating air conditioning apparatus which can ensure the comfort at the time of driving | operation can be obtained.
[0097]
reference Form 4.
Hereinafter, the present invention reference As an example of the refrigeration air-conditioning apparatus according to the fourth embodiment, an apparatus that performs indoor air conditioning will be described. Book reference Even in the form of reference As in the third embodiment, a container is provided on at least one of the high pressure side and the low pressure side of the refrigeration cycle to increase the volume on the high pressure side or the low pressure side. As a result, the pressure pulsation generated on the refrigeration cycle by time-controlled operation of a compressor that can be operated in a stepwise capacity, the fluctuation range of the heat exchange amount in the heat exchanger, the air heat exchanger in the heat exchanger The fluctuation range of the blown-out air temperature when using is reduced, and the fluctuation of the refrigeration capacity or the air conditioning capacity in the refrigeration air conditioner is reduced. Further, in the present embodiment, in addition to suppressing the pressure fluctuation by increasing the volume on the high-pressure side or the low-pressure side, other functions that are effective in configuring the refrigeration cycle as the high-pressure side container or the low-pressure side container Also provided with a container that also has.
[0098]
Figure 16 shows a book reference It is a refrigerant circuit figure which shows the structure of the refrigerating and air-conditioning apparatus by the form. In the figure, 17 is a low-pressure side container, 18 is an oil separator, and 19 is an oil return circuit for returning the oil separated by the oil separator 18 to the compressor suction side. In addition, the other structure of FIG. 16, the flow of a refrigerant | coolant, and the switching method of the capacity | capacitance of the compressor in FIG. 16 are the same as that of Embodiment 1. FIG.
[0099]
The compressors 1a and 1b are usually filled with lubricating oil in order to smoothly operate each member. Part of this oil is discharged from the compressors 1a and 1b together with the gas refrigerant, and circulates in the refrigeration cycle together with the refrigerant. However, if this oil is stored in the liquid pipe 6 and the gas pipe 9 during circulation, the amount of oil in the compressors 1a and 1b decreases without returning to the compressors 1a and 1b. When the amount of oil that lubricates the operations of the members in the compressors 1a and 1b is reduced, the operations of the compressors 1a and 1b are not smoothly performed.
Book reference In this embodiment, an oil separator 18 is provided in the discharge side pipes of the compressors 1a and 1b, and oil discharged from the compressors 1a and 1b together with the gas refrigerant is separated by the oil separator 18 and then passed through an oil return circuit 19. By returning to the suction side of the compressors 1a and 1b, a situation where the compressors 1a and 1b are damaged can be avoided.
Furthermore, by increasing the volume on the high pressure side by the amount of the oil separator 18, it is possible to suppress pressure fluctuations in the time control operation of the compressor 1a that can be operated with a stepped capacity.
[0100]
Thus, the function of increasing the volume on the high pressure side by the oil separator 18 and the function of returning the oil discharged from the compressors 1a and 1b are combined. For this reason, the fluctuation range of the pressure by the time-controlled operation of the compressor 1a can be suppressed, the comfort during the operation of the refrigeration air conditioner can be ensured, and the reliability when the compressors 1a and 1b are operated can be improved. it can. Normally, if the volume of the oil separator 18 is about 3L, and each high-pressure side equipment and piping constituting the refrigeration cycle are about 5L, the operating capacity fluctuation range is 2HP, the operating capacity control interval (short cycle) according to FIG. ) Is 10 seconds, the pressure fluctuation range is 2 kg / cm. ² Can be about.
Thus, by providing the oil separator 18 on the discharge side of the compressors 1a and 1b, it is possible to ensure comfort during operation of the refrigeration air conditioner and improve reliability during operation of the compressor. .
[0101]
Moreover, you may provide the liquid receiver 30 in the outdoor heat exchanger 5 exit like FIG. The outdoor heat exchanger 5 operates as a condenser when the refrigeration air conditioner is performing a cooling operation. By providing the liquid receiver 30 at the outlet of the condenser, the amount of refrigerant in the refrigeration air-conditioning apparatus is adjusted, and the optimum state of operation of the optimum refrigeration cycle is achieved. Furthermore, since the excess refrigerant can be retained in the refrigeration cycle, even if there is an excess refrigerant in the refrigeration cycle, the operation of returning the liquid to the compressors 1a and 1b is not performed, and damage to the compressor due to liquid compression can be avoided. . Further, by providing the liquid receiver 30, the volume on the high pressure side is increased in the cooling operation, and the fluctuation range of the pressure generated by the time-controlled operation of the compressor 1a that can be operated with a stepped capacity is suppressed. To do.
Thus, by providing the liquid receiver 30 at the outlet of the heat exchanger that operates as a condenser, it is possible to ensure comfort during operation of the refrigeration air conditioner and improve reliability during operation of the compressor. Can do.
When the liquid receiver 30 is connected as shown in the figure, there is an effect of increasing the volume on the low pressure side when switching to the heating operation.
[0102]
Further, as shown in FIG. 18, an accumulator 31 may be provided on the suction side of the compressors 1a and 1b. By providing the accumulator 31, the liquid refrigerant flowing to the compressor suction side during the start-up operation in the refrigerating and air-conditioning apparatus is held in the accumulator 31, so that the liquid returns to the compressors 1a and 1b at the start-up. Therefore, it is possible to improve reliability by avoiding breakage of the compressors 1a and 1b due to liquid compression. Furthermore, by providing the accumulator 31, the volume on the low pressure side of the refrigeration cycle can be increased, the fluctuation range of pressure generated by the compressor 1a performing time control operation can be suppressed, and the refrigeration air conditioner can be operated. Can ensure the comfort of
Thus, by providing the accumulator 31 on the suction side of the compressors 1a and 1b, which is the low-pressure side of the refrigeration cycle, it is possible to ensure comfort during operation of the refrigeration air conditioner and reliability during operation of the compressor. Can be improved.
[0103]
16, 16, and 17, each refrigeration and air-conditioning apparatus has an oil separator 18, a liquid receiver 30, and an accumulator 31. However, the refrigeration and air-conditioning apparatus may have all of these, or may have any two. . Further, if the configuration including the oil separator 18, the liquid receiver 30, and the accumulator 31 is insufficient, the refrigerant container 16 or the low-pressure side is provided on the high-pressure side as having a function of increasing the volume as shown in FIG. Alternatively, the refrigerant container 17 may be provided separately.
[0104]
reference Form 5.
Hereinafter, the present invention reference As an example of the refrigeration air-conditioning apparatus according to the fifth embodiment, an apparatus that performs indoor air conditioning will be described. 19 is a book reference It is a refrigerant circuit figure which shows the structure of the refrigerating and air-conditioning apparatus by the form. In the figure, 32 is a resistance element for adding a flow resistance provided on the discharge side of the compressor. For example, the diameter of a part of the refrigerant pipe is made smaller than the diameter of the other part to provide a resistance element against the flow of the refrigerant. It is composed. Reference numeral 33 denotes a resistance element for adding a flow resistance provided on the suction side of the compressor. For example, like the resistance element 32, the diameter of a part of the refrigerant pipe is made smaller than the diameter of the other part to A resistive element is configured. The other configuration in FIG. 19, the refrigerant flow, and the method for switching the compressor capacity in FIG. 19 are the same as those in the first embodiment.
[0105]
As described above, in the compressor 1a that can be operated at a stepped capacity, the pressure pulsation generated on the refrigeration cycle when performing time-controlled operation causes the refrigerant flow rate sucked and discharged to the compressor 1a to be short. By changing the cycle, the flow rate of refrigerant flowing into the high pressure side and the flow rate of refrigerant flowing out from the low pressure side fluctuate in a short time, and the amount of refrigerant existing on the high pressure side and low pressure side fluctuates accordingly. It is caused by causing. Therefore, if fluctuations in the refrigerant flow rate flowing into the high pressure side and the refrigerant flow rate flowing out from the low pressure side can be suppressed, pressure pulsation generated on the refrigeration cycle can be suppressed.
[0106]
Book reference In this embodiment, the resistance element 32 and the resistance element 33 are provided on the discharge side and the suction side of the compressor 1a. Here, for example, the operation of the resistance element 32 provided on the discharge side of the compressor 1a will be described. When the compressor 1a performs time-controlled operation and the operating capacity is switched from a small capacity to a large capacity, the flow rate of refrigerant discharged from the compressor 1a increases, and the increase is the resistance element 32. This increases the pressure on the compressor side and then passes through the resistance element 32 and contributes to an increase in the refrigerant flow rate. For this reason, compared with the case where the resistance element 32 is not provided, an increase in the refrigerant amount on the high pressure side can be suppressed.
Further, when the operation capacity of the compressor 1a is switched from the large capacity to the small capacity in the time control operation, the refrigerant flow rate discharged from the compressor 1a is decreased, and as a result, the compression of the resistance element 32 is performed. A pressure decrease occurs on the machine side, and an amount of refrigerant corresponding to the pressure decrease passes through the resistance element 32. For this reason, a decrease in the amount of refrigerant on the high-pressure side can be suppressed compared to when the resistance element 32 is not provided. This operation is the same for the resistance element 33 on the low voltage side.
[0107]
When the resistance elements 32 and 33 are provided in the refrigerant flow path as described above, the resistance elements 32 and 33 can be used as refrigerant even if the refrigerant flow rate sucked into and discharged from the compressor 1a varies due to the change in the operation capacity of the compressor 1a. Due to the flow resistance at the time of passage of the refrigerant, the fluctuation amount of the refrigerant flow hardly passes through the resistance elements 32 and 33. For this reason, the fluctuation | variation of the refrigerant | coolant flow volume which flows in into a high voltage | pressure side and the refrigerant | coolant flow volume which flows out out of a low voltage | pressure side can be made smaller than the fluctuation | variation of the refrigerant | coolant flow volume generate | occur | produced with the compressor 1a.
Therefore, the pressure pulsation generated on the refrigeration cycle can be suppressed, and the fluctuation range of the heat exchange amount in the heat exchanger, the fluctuation range of the blown air temperature when the air heat exchanger is used as the heat exchanger, etc. Since the refrigeration capacity of the refrigeration air conditioner can be reduced and fluctuations in the refrigeration capacity or air conditioning capacity can be reduced, it is possible to ensure comfort during operation of the refrigeration air conditioner.
[0108]
In the configuration of FIG. 19, resistance elements 32 and 33 are provided on the high voltage side and the low voltage side, respectively. Preferably, the resistance elements 32 and 33 are provided on either side, but the effect is large in either one.
Further, the resistance element that adds flow resistance may be any configuration that adds flow resistance to the refrigerant flowing through the piping, such as a capillary, by providing a throttle in the refrigerant piping.
[0109]
Further, the resistance element 32 provided on the discharge side of the compressor may be a check valve that allows a flow in the direction from the compressors 1a and 1b to the four-way valve 4 to pass therethrough and prevents a reverse flow. In this way, the resistance element 32 that adds flow resistance to the refrigerant flow on the high-pressure side serves as a check valve, and in addition to the effect of suppressing pressure pulsation generated on the refrigeration cycle, Through the four-way valve 4 from the heat exchanger 5 or the indoor heat exchangers 8a and 8b, it is possible to prevent the liquid refrigerant from flowing into the compressors 1a and 1b from the discharge side of the compressors 1a and 1b. If the flow of the liquid refrigerant to the compressors 1a and 1b is allowed to stand during the stop, the liquid refrigerant flows into the compressors 1a and 1b when the refrigeration air conditioner is started. May cause damage to the compressors 1a and 1b. On the other hand, by providing the check valve 32, the liquid can be prevented from flowing into the compressors 1a and 1b even when the refrigeration air conditioner is stopped, and the compressor can be prevented from being damaged by the liquid compression. High-performance driving is possible.
[0110]
In addition, as shown in FIG. 20, even if the check valves 32a and 32b are provided as resistance elements in the discharge pipes 2a and 2b of the compressors 1a and 1b, the same effect can be obtained.
[0111]
reference Form 6.
Hereinafter, the present invention reference As an example of the refrigeration air-conditioning apparatus according to the sixth embodiment, an apparatus that performs indoor air conditioning will be described. Figure 21 shows the book reference It is a refrigerant circuit figure which shows the structure of the refrigerating and air-conditioning apparatus by the form. In the figure, 34 is a bypass circuit, for example, a circuit for connecting the discharge side of the compressor and the suction side of the compressor, and 35 is a control valve for controlling the flow rate of the refrigerant flowing through the bypass circuit 34. The other configuration in FIG. 21, the refrigerant flow, and the method for switching the compressor capacity in FIG. 21 are the same as those in the first embodiment.
[0112]
As described above, in the compressor 1a that can be operated at a stepped capacity, the pressure pulsation generated on the refrigeration cycle when performing time-controlled operation causes the refrigerant flow rate sucked and discharged to the compressor 1a to be short. By changing the cycle, the flow rate of refrigerant flowing into the high pressure side and the flow rate of refrigerant flowing out from the low pressure side fluctuate in a short time, and the amount of refrigerant existing on the high pressure side and low pressure side fluctuates accordingly. It is caused by causing. Therefore, if fluctuations in the refrigerant flow rate flowing into the high pressure side and the refrigerant flow rate flowing out from the low pressure side can be suppressed, pressure pulsation generated on the refrigeration cycle can be suppressed.
[0113]
Book reference In the embodiment, when the time-controlled operation is performed in the compressor 1a, the control valve 35 is opened so that the refrigerant flows from the discharge side to the suction side of the compressors 1a and 1b. The control valve 35 is closed when the compressor 1a stops or operates at a constant capacity in a short cycle.
When a time-controlled operation is performed by the compressor 1a and the operating capacity is switched from a small capacity to a large capacity, the refrigerant flow rate sucked into and discharged from the compressor 1a increases and exists on the high pressure side. As the amount of refrigerant increases and the high pressure rises, the flow rate of refrigerant flowing out from the low pressure side also increases, and the low pressure decreases. Therefore, the pressure difference between the high pressure and the low pressure increases. When the pressure difference increases, the flow rate of the refrigerant flowing through the bypass circuit 34 increases. An increase in the flow rate of refrigerant flowing through the bypass circuit 34 means that both the flow rate of refrigerant flowing out from the high-pressure side and the flow rate of refrigerant flowing into the low-pressure side both increase, compared to when no refrigerant flows through the bypass circuit 34. It is possible to suppress an increase in the amount of refrigerant existing on the high pressure side and a decrease in the amount of refrigerant existing on the low pressure side. As described above, fluctuations in the refrigerant amount existing on the high-pressure side and the low-pressure side can be suppressed, so that pressure pulsation generated on the refrigeration cycle can be suppressed.
[0114]
When the compressor 1a is operated in a time-controlled manner and the operating capacity is switched from a large capacity to a small capacity, the refrigerant flow rate sucked into and discharged from the compressor 1a decreases, and the amount of refrigerant existing on the high pressure side Decreases, the high pressure decreases, the refrigerant flow rate flowing out from the low pressure side also decreases, and the low pressure increases. Accordingly, the pressure difference between the high pressure and the low pressure is reduced. When the pressure difference decreases, the refrigerant flow rate flowing through the bypass circuit 34 decreases. The fact that the flow rate of the refrigerant flowing through the bypass circuit 34 decreases means that the flow rate of refrigerant flowing out from the high pressure side and the flow rate of refrigerant flowing into the low pressure side both decrease, so that compared to when no refrigerant flows through the bypass circuit 34. It is possible to suppress a decrease in the amount of refrigerant existing on the high pressure side and an increase in the amount of refrigerant existing on the low pressure side. As described above, fluctuations in the refrigerant amount existing on the high-pressure side and the low-pressure side can be suppressed, so that pressure pulsation generated on the refrigeration cycle can be suppressed.
[0115]
As above, the book reference In this embodiment, the bypass circuit 34 and the control valve 35 are provided, and the high-pressure side and the low-pressure side of the refrigeration cycle are connected when the compressor 1a is performing the time control operation. Thus, an appropriate amount of refrigerant that reduces the fluctuation of the refrigerant amount flows through the bypass circuit 34, the pressure pulsation width generated on the refrigeration cycle by the time control operation, the fluctuation range of the heat exchange amount in the heat exchanger, the heat When the air heat exchanger is used as the exchanger, the fluctuation range of the blown air temperature is reduced. For this reason, the fluctuation | variation of the refrigerating capacity or air-conditioning capacity in a refrigerating air conditioner can be made small, and the comfort at the time of a refrigerating air conditioner driving | operation can be ensured.
[0116]
The high pressure side and the low pressure side may always be connected by the bypass circuit 34 without providing the control valve 35. At this time, it is desirable that the bypass circuit 34 is configured so that a refrigerant of about 1/100 to 10/100 flows with respect to the flow of the refrigerant in the main pipe constituting the refrigeration cycle.
Of course, flowing the refrigerant through the bypass circuit 34 connecting the discharge side and the suction side of the compressor does not use a part of the flow rate of the compressor for the cooling capacity or heating capacity of the refrigeration air conditioner. Reduce the operating efficiency of the cycle. Therefore, when the control valve 35 does not perform the time control operation with the compressor 1a, the operation efficiency of the refrigeration cycle can be prevented from being lowered by closing the bypass circuit 34.
[0117]
Further, by using the bypass circuit 34 as a circuit for connecting the discharge side and the suction side of the compressor in this way, when the load on the refrigeration air conditioner increases or due to an abnormality in the heat exchanger serving as a condenser, the high pressure is increased. When the pressure rises excessively, the control valve 35 is opened and the refrigerant is allowed to flow through the bypass circuit 34, so that the high pressure rise can be suppressed. By bypassing the high-pressure refrigerant to the low-pressure side by the bypass circuit 34, it is possible to prevent the compressor from being damaged due to an excessive increase in the high pressure, and in addition to suppressing the pressure pulsation generated on the refrigeration cycle, Reliability in the operation of the refrigeration air conditioner can be improved.
[0118]
Further, as shown in FIG. 16, the bypass circuit 34 may be used also as an oil return circuit 19 that returns the oil separated by the oil separator 18 to the compressor suction side. By using the oil separator 18, in addition to the above effects, the lubricating oil in the compressor flowing out together with the gas refrigerant from the discharge side of the compressors 1a and 1b can be returned to the compressor. Operation failure and damage can be prevented, and the reliability of the refrigeration air conditioner can be improved.
[0119]
Further, the bypass circuit 34 that connects the high-pressure side and the low-pressure side is not limited to the bypass circuit 34 that connects the discharge side and the suction side of the compressor, and may have other configurations.
Figure 22 shows the book reference It is a refrigerant circuit figure which shows the other structure of the refrigerating air conditioning apparatus by the form. In this configuration, one end of the bypass circuit 34 is connected to the liquid pipe 6 between the outdoor heat exchanger 5 and the expansion valves 7a and 7b, and the other end of the bypass circuit 34 is connected to the suction pipes 3a and 3b of the compressor. ing. With this configuration, the outdoor heat exchanger 5 operates as a condenser during the cooling operation. Accordingly, the outlet of the outdoor heat exchanger 5 on the high pressure side and the compressor suction side on the low pressure side are connected, so that the discharge side and the suction side of the compressor are connected on the refrigeration cycle. It is possible to suppress the generated pressure pulsation.
Moreover, if it connects in this way, the liquid refrigerant condensed with the outdoor heat exchanger 5 at the time of air_conditionaing | cooling operation can be returned to compressor 1a, 1b. For example, when the discharge temperature of the compressors 1a and 1b rises during operation, the control valve 35 is opened and the liquid refrigerant is returned to the compressors 1a and 1b. It becomes possible to improve the reliability of machine operation.
The control valve 35 in FIGS. 22 and 23 may have any opening / closing function for opening / closing the bypass circuit 34.
[0120]
In addition, FIG. reference It is a refrigerant circuit figure which shows the further another structure of the refrigerating and air-conditioning apparatus by the form. In the figure, reference numeral 36 denotes a heat exchanging section for exchanging heat between the bypassed liquid refrigerant and the high-pressure liquid refrigerant, for example, a high-low pressure heat exchanger. The control valve 35 having this configuration has a pressure reducing function.
The liquid refrigerant flowing through the bypass circuit 34 during the cooling operation is decompressed by the control valve 35 and becomes a low-pressure and low-temperature two-phase refrigerant. By exchanging heat between the two-phase refrigerant and the high-pressure and high-temperature liquid refrigerant flowing through the liquid pipe 6 by the high-low pressure heat exchanger 36, the low-pressure two-phase refrigerant is evaporated and gasified. Accordingly, in addition to suppressing the pressure pulsation generated on the refrigeration cycle by the bypass circuit 34, the latent heat of vaporization of the liquid refrigerant to be bypassed can be recovered, and the cooling capacity is reduced by bypassing the liquid refrigerant during the cooling operation. Can be reduced.
Furthermore, since the flow rate of the refrigerant flowing from the outdoor heat exchanger 5 to the indoor heat exchangers 8a and 8b during the cooling operation can be reduced without lowering the cooling capacity, the pressure loss generated in the gas pipe 9 can be reduced. It is possible to operate the refrigeration air conditioner with high efficiency.
[0121]
reference Form 7.
Hereinafter, the present invention reference An apparatus for performing indoor air conditioning will be described as a refrigeration air conditioner according to Embodiment 7. Figure 24 shows the book reference It is a refrigerant circuit figure which shows the structure of the refrigerating and air-conditioning apparatus by the form. Book reference In this embodiment, as shown in the figure, the oil return circuit 19 for oil separated by the oil separator 18 is connected to the high pressure side solenoid valve 10a, and the oil separated by the oil separator 18 is supplied to the high pressure side solenoid valve 10a. When this is opened, it passes through the high pressure side solenoid valve 10a and is supplied to the low pressure side solenoid valve 10b. The supplied oil flows into the low-pressure side electromagnetic valve 10b, and then passes through the low-pressure side electromagnetic valve 10b when it is opened, and is returned to the compressor suction side. 24, the refrigerant flow, and the method for switching the compressor capacity in FIG. 24 are the same as those in the first embodiment.
[0122]
Book reference In the case of switching the operation capacity of the compressor 1a by opening and closing the high-pressure side solenoid valve 10a and the low-pressure side solenoid valve 10b, which are two control valves, the number of times each solenoid valve is opened and closed increases. For example, considering the time for operating the compressor 1a at the maximum capacity and the time for operating at the minimum capacity as one set, the length of the short cycle that combines the time to operate at the maximum capacity and the time at the minimum capacity is 10 seconds, When the operation time of the compressor 1a is 25,000 hours, the number of opening and closing of the solenoid valves 10a and 10b is 9 million, which is much higher than the level of hundreds of thousands of durable opening and closing times of a general solenoid valve. Opening and closing times are required.
[0123]
Figure 25 shows a book reference It is sectional drawing which shows the structure of the solenoid valves 10a and 10b concerning the form. In the figure, 37 is a movable valve, 38 is a valve seat, 39 is a plunger, 40 is a coil, 41 is a valve inlet side flow path, and 42 is a valve outlet side flow path. The operation of the solenoid valves 10a and 10b is as follows.
When the valve is opened, a current is passed through the coil 40 to generate a magnetic force from the movable valve 37 to the plunger 39 by electromagnetic force, thereby attracting the movable valve 37 to the plunger 39. When the plunger 39 moves upward in the figure, a gap is generated between the movable valve 37 and the valve seat 38, the valve inlet side flow path 41 and the valve outlet side flow path 42 are communicated, and the valve is opened.
When the valve is closed, no current flows through the coil 40. Then, the magnetic force from the movable valve 37 to the plunger 39 is lost, and the force for attracting the movable valve 37 to the plunger 39 is lost. For this reason, while the plunger 39 moves downward in the figure, the pressure of the flowing refrigerant is higher on the valve inlet side 41 than on the valve outlet side 42, so that the movable valve 37 is pressed against the valve seat 38 by the pressure difference of the refrigerant. . By doing so, there is no gap between the movable valve 37 and the valve seat 38, and the valve inlet side channel 41 and the valve outlet side channel 42 are closed.
[0124]
Therefore, every time the solenoid valves 10a and 10b are opened and closed, the plunger 39 and the movable valve 37, and the movable valve 37 and the valve seat 38 collide. Therefore, if the number of times of opening and closing the solenoid valves 10a and 10b is increased, the plunger 39, Wear of the movable valve 37, the valve seat 38, etc. advances. In particular, there is a possibility that a gap may be formed between the movable valve 37 and the valve seat 38 due to wear and cannot be completely closed. Book reference In this configuration, the oil separated by the oil separator 18 is supplied to the electromagnetic valves 10a and 10b in order to prevent wear of the movable valve 37 and the valve seat 38 and to secure a predetermined durable opening / closing frequency. By supplying oil to the solenoid valves 10a and 10b, the contact portion between the movable valve 37 and the valve seat 38, the contact portion between the plunger 39 and the movable valve 37, the sliding portion between the movable valve 37 and the inner surface of the container, and the like. An oil film is formed. The oil film serves as an impact mitigating means for mitigating an impact in a collision at a contact portion of the electromagnetic valves 10a and 10b, for example, a contact portion between the movable valve 37 and the valve seat 38, and the movable valve 37 and the valve seat 38 are in contact with each other. Wear of parts can be prevented.
[0125]
The oil film can be formed with a small amount of oil, and if the amount of oil taken out from the compressors 1a and 1b is large, the amount of oil supplied to the solenoid valves 10a and 10b may be excessively increased. If the amount of oil supplied to the solenoid valves 10a and 10b is too large and the solenoid valves 10a and 10b are filled with oil, the viscosity of the oil is larger than that of the refrigerant, so that the amount of oil in the solenoid valves 10a and 10b is large. As a result, more electromagnetic force is required to open and close the electromagnetic valves 10a and 10b. Therefore, if the solenoid valves 10a and 10b are designed to be opened and closed when a refrigerant is used, when the valve is filled with oil, the solenoid valves 10a and 10b cannot be opened and closed sufficiently due to insufficient electromagnetic force. As a result, the capacity control of the compressor may not be performed. Therefore, when supplying oil to the solenoid valves 10a and 10b, it is necessary to supply an optimum amount of oil to the solenoid valves 10a and 10b.
[0126]
So book reference In this embodiment, various configurations are provided for the state of oil when oil is supplied to the solenoid valves 10a and 10b.
First, in the configuration shown in FIG. 24, oil that has flowed out of the compressor together with the refrigerant gas is separated by the oil separator 18, and oil that is not mixed with refrigerant is supplied to the electromagnetic valves 10a and 10b. In this case, the amount of oil supplied to the solenoid valves 10a and 10b is relatively large.
[0127]
In the configuration shown in FIG. 26, the compressor discharge side and the high pressure side solenoid valve 10a between the compressors 1a and 1b and the oil separator 18 are connected, so that the solenoid valves 10a and 10b can be connected to the solenoid valve 18 before passing through the oil separator 18. Supply refrigerant gas. In this case, the amount of oil supplied to the electromagnetic valves 10a and 10b is smaller than that of the configuration in which the oil return circuit 19 of the oil separator 18 is connected to the electromagnetic valve 10a, that is, the configuration shown in FIG. This is because refrigerant gas before passing through the oil separator 18 is supplied to the solenoid valves 10a and 10b together with oil, and the amount of oil is smaller than that of supplying oil after separation.
[0128]
In the configuration shown in FIG. 27, the refrigerant discharge gas after passing through the oil separator 18 is connected to the solenoid valves 10a and 10b by connecting the compressor discharge side between the oil separator 18 and the four-way valve 4 and the high-pressure side solenoid valve 10a. Supply. In this case, since the oil contained in the refrigerant gas is removed by the oil separator 18, the amount of oil supplied to the solenoid valves 10a and 10b is shown in FIG. 26 in which the refrigerant gas before passing through the oil separator 18 is supplied. Less than that of the other configuration. However, since the oil contained in the refrigerant gas cannot be completely removed by the oil separator 18, a small amount of oil can be supplied even if the refrigerant gas after passing through the oil separator 18 is supplied. The amount of oil supplied depends greatly on the performance of the oil separator 18.
[0129]
As shown in FIGS. 24, 26, and 27, the amount of oil supplied to the solenoid valves 10a and 10b can be increased or decreased, so that the state of oil flowing out from the compressors 1a and 1b, the nature of the oil or refrigerant, the oil separator The configuration can be selected according to the performance of the system.
For example, when the amount of oil taken out from the compressors 1a and 1b is excessive, if the oil return circuit 19 of the oil separator 18 is connected to the solenoid valve 10a as shown in FIG. 24, the solenoid valves 10a and 10b are filled with oil. there is a possibility. At this time, the refrigerant gas before passing through the oil separator 18 is supplied as shown in FIG. In addition, even if the refrigerant gas before passing through the oil separator 18 is supplied as shown in FIG. 26, if the solenoid valves 10a and 10b are filled with oil, the refrigerant gas after passing through the oil separator 18 as shown in FIG. What is necessary is just to supply.
[0130]
On the other hand, for example, when the amount of oil taken out from the compressors 1a and 1b is small, when the refrigerant gas after passing through the oil separator 18 is supplied to the electromagnetic valve 10a as shown in FIG. 27, the contact between the movable valve 37 and the surface of the valve seat 38, etc. There is a possibility that an oil film for impact relaxation action cannot be formed on the part. At this time, the refrigerant gas before passing through the oil separator 18 is supplied to the electromagnetic valve 10a as shown in FIG. If the oil film cannot be formed on the surfaces of the movable valve 37 and the valve seat 38 even if the refrigerant gas before passing through the oil separator 18 is supplied as shown in FIG. 26, the oil return circuit 19 of the oil separator 18 as shown in FIG. May be connected to the electromagnetic valve 10a to supply the separated oil.
[0131]
As above, the book reference 24, 26, and 27, the oil that flows out from the compressors 1a and 1b together with the refrigerant gas is supplied to the electromagnetic valves 10a and 10b and then returned to the compressors 1a and 1b. For this reason, the contact portions by opening and closing the electromagnetic valves 10a and 10b, for example, the movable valve 37 and the valve seat 38 are formed with an oil film to reduce the impact, thereby preventing the contact portions from being worn and the valve closing performance. Secure.
Further, in the configurations of FIGS. 24, 26, and 27, the refrigerating and air-conditioning apparatus is based on the amount of oil flowing out from the compressors 1a and 1b, the degree of oil film in the contact portion depending on the nature of the oil, and the like. By selecting the optimum configuration, an appropriate amount of oil can be supplied to the solenoid valves 10a and 10b, and the solenoid valve can be reliably opened and closed without filling the solenoid valve. Can be secured.
[0132]
reference Form 8.
Hereinafter, the present invention reference An apparatus for performing indoor air conditioning, for example, as a refrigeration air conditioner according to Embodiment 8 will be described. Book reference Is provided with cooling means for cooling the electromagnetic valves 10a and 10b, which are control valves when performing the time-controlled operation of the compressor 1a, and attempts to prevent the deterioration of each member due to the temperature rise of the expansion valves 10a and 10b. Is.
Figure 28 shows the book reference It is a refrigerant circuit figure which shows the structure of the refrigerating and air-conditioning apparatus by the form. In the figure, 7c is an expansion valve, and 43 is a pipe for supplying high-pressure liquid refrigerant to the electromagnetic valve 10a. Other configurations in FIG. 28 are the same as those in the first embodiment. In Embodiments 1 to 7, the refrigerant gas flow pipe and the high pressure side solenoid valve 10a are connected. However, in the configuration of FIG. 28, the refrigerant liquid pipe and the high pressure side solenoid valve 10a are connected. It is configured. By supplying this high-pressure liquid refrigerant to the solenoid valves 10a and 10b, the solenoid valves 10a and 10b are not affected by the opening and closing of the solenoid valves 10a and 10b, and the solenoid valves 10a and 10b are cooled. 10b is supplied with oil flowing together with the refrigerant.
[0133]
Book reference In this embodiment, the expansion valve 7c is provided on the outlet side of the outdoor heat exchanger 5 that operates as a condenser during the cooling operation, and the liquid pipe 6 and the high-pressure side electromagnetic valve 10a between the expansion valve 7c and the expansion valves 7a and 7b. Are connected by a pipe 43. Here, by providing the expansion valve 7c between the outdoor heat exchanger 5 and the expansion valves 7a and 7b, the control when the time-controlled operation of the compressor 1a is performed in both the cooling operation and the heating operation. The high-pressure liquid refrigerant can be supplied to the solenoid valves 10a and 10b, which are valves.
In the cooling operation, the expansion valve 7c is fully opened and the pressure is not reduced, so that a part of the high-pressure liquid refrigerant condensed in the outdoor heat exchanger 5 is supplied to the electromagnetic valves 10a and 10b. The refrigerant not supplied to the electromagnetic valves 10a and 10b is decompressed by the expansion valves 7a and 7b and flows into the indoor heat exchangers 8a and 8b. Other refrigerant flows and compressor capacity switching methods in the cooling operation are the same as those in the first embodiment.
On the other hand, in the heating operation, the expansion valves 7a and 7b are fully opened so that the pressure is not reduced, so that the high-pressure liquid refrigerant condensed in the indoor heat exchangers 8a and 8b reaches the connection point of the pipe 43 that supplies the electromagnetic valves 10a and 10b. Shed. And a part flows into the piping 43 and is supplied to electromagnetic valve 10a, 10b. The high-pressure liquid refrigerant that has not flowed into the pipe 43 is decompressed by the expansion valve 7 c and then flows into the outdoor heat exchanger 5. Other refrigerant flow and compressor capacity switching methods in the heating operation are the same as those in the first embodiment.
[0134]
Book reference In this embodiment, the operating capacity is switched in the time-controlled operation of the compressor 1a by opening and closing the high-pressure side solenoid valve 10a and the low-pressure side solenoid valve 10b. As described above, the number of times the solenoid valves 10a and 10b are opened and closed. Become more. When the operating capacity is switched, a current flows through the coils 40 of the solenoid valves 10a and 10b without interruption, so that the amount of heat generated by the coils 40 increases and the temperature of the solenoid valves 10a and 10b itself increases. When the temperature of the solenoid valves 10a and 10b rises, the materials of the solenoid valves 10a and 10b are likely to be deteriorated, and the malfunction of the solenoid valves 10a and 10b is likely to be caused. Therefore, in order to ensure the reliability of driving of the solenoid valves 10a and 10b, it is necessary to cool the solenoid valves 10a and 10b. Book reference In this embodiment, a high-pressure liquid refrigerant is used as the cooling heat source. The operation of the solenoid valves 10a and 10b is to switch the capacity of the compressor 1a. Therefore, when the solenoid valve 10a is opened (the solenoid valve 10b is closed), a high pressure is applied to the capacity control pipe 15a. What is necessary is just to apply a low pressure to the capacity control pipe 15a when it is opened (the solenoid valve 10a is closed). In the configuration of FIG. 28, in both the cooling operation and the heating operation, the high-pressure side electromagnetic valve 10a can be opened and the high-pressure liquid refrigerant can be supplied from the pipe 43. Therefore, high pressure is applied to the capacity control pipe 15, so the compressor 1a There is no problem with the controllability of the operating capacity.
[0135]
Here, by supplying the high-pressure liquid refrigerant condensed in the refrigeration cycle to the electromagnetic valves 10a and 10b, it also serves as a cooling means for cooling the electromagnetic valves 10a and 10b. That is, the high-pressure liquid refrigerant supplied from the pipe 43 flows into the high-pressure side electromagnetic valve 10a and cools it. The solenoid valves 10a and 10b are alternately controlled to open and close in a short cycle. At the opening timing, the solenoid valves 10a and 10b flow from the high pressure side solenoid valve 10a to the low pressure side solenoid valve 10b and cool it.
The temperature of the high-pressure liquid refrigerant is about the condensation temperature of the refrigeration cycle, and is about 50 ° C. The deterioration of the material of the solenoid valves 10a and 10b is designed to be prevented if the temperature of the solenoid valve can be cooled to 120 ° C. By supplying a high-pressure liquid refrigerant of about 50 ° C to the solenoid valves 10a and 10b, The valves 10a and 10b can be sufficiently cooled.
[0136]
Book like this reference In this embodiment, by supplying high-pressure liquid refrigerant to the solenoid valves 10a and 10b and cooling them, deterioration of the materials of the solenoid valves 10a and 10b due to temperature rise can be prevented, and the life of the solenoid valves 10a and 10b can be extended. The reliability in the opening / closing operation can be improved.
[0137]
Figure 29 shows a book reference It is explanatory drawing which shows the other structure of the refrigerating air-conditioning apparatus by the form 8 of FIG. 29, (a) showed the structure when the outdoor unit was seen from the front, and (b) looked at the outdoor unit from the side. The structure of the hour is shown. In this configuration, the cooling means for cooling the electromagnetic valves 10a and 10b is configured to be cooled by outside air around the refrigeration air conditioner.
[0138]
The outdoor unit 44 is equipped with the compressors 1a and 1b, the four-way valve 4, the outdoor heat exchanger 5 using air as a heat source, and the like. In FIG. A heat exchanger 5 is arranged. As indicated by the arrows in FIG. 29B, the air sucked from the front and back surfaces is subjected to heat exchange in the outdoor heat exchanger 5, and then the air is discharged to the upper part. The lower 1/4 portion of the outdoor unit 44 is a machine room 45, and the compressor 1a and the electromagnetic valves 10a and 10b are arranged. Here, the flow of the wind of the outdoor unit 44 is partially passed through the machine room 45 as shown in FIG. 29B to cool the electromagnetic valves 10a and 10b arranged in the machine room 45 with the outside air. Is possible. Since the temperature of the outside air is at most about 40 ° C., the temperature of the solenoid valve can be cooled to 120 ° C. or less.
[0139]
Thus, the electromagnetic valves 10a and 10b can be sufficiently cooled even by air, the deterioration of the material of each member due to the temperature rise of the electromagnetic valves 10a and 10b is prevented, and the reliability when driving the electromagnetic valves 10a and 10b is improved. be able to.
[0140]
reference Form 9.
Hereinafter, the present invention reference A control valve related to the refrigerating and air-conditioning apparatus according to Embodiment 9 will be described. Figure 30 shows the book reference It is sectional drawing which shows the structure of the control valve by this form. In the figure, 46a and 46b are speed reducing means, for example, springs. Other configurations are the same as those in FIG.
As described above, the control valve that performs switching in the time-controlled operation of the compressor 1a that can be operated with a stepped capacity is required to have a large number of usable opening and closing times. This control valve is configured to open and close the flow path by movement of the movable valve 37, the movable valve 37 and the valve seat 38 when the flow path is closed, and the plunger 39 and the movable valve when the flow path is opened. Considering the strength of contact portions such as 37, it is desirable to use stone or metal as the material of these contact portions. However, when stone or metal is used as the material of each contact portion, a collision sound is generated when the movable valve 37 and the valve seat 38 collide as described in the problem of the prior art. Particularly, when the time-controlled operation of the compressor 1a is performed, since the electromagnetic valves 10a and 10b are opened and closed once every several seconds to several tens of seconds, a collision sound is generated once every several seconds to several tens of seconds. Therefore, if the collision sound is large, noise is generated without interruption in the outdoor unit 44, which becomes a problem for the surrounding environment. For this reason, it is necessary to improve the reliability of the electromagnetic valves 10a and 10b and reduce the generated driving noise.
[0141]
In the present embodiment, as an impact mitigation means, a part that comes into contact when the electromagnetic valves 10a and 10b are closed, for example, a part of the part where the movable valve 37 and the valve seat 38 are in contact with each other, is made of Teflon which is one of resins. Is used. Teflon is softer than stone and metal and strong against a certain level of impact, so it absorbs the impact force when the movable valve 37 and the valve seat 38 collide with each other. It becomes possible to reduce.
Similarly, it is necessary to reduce the collision sound when the electromagnetic valve 10a, 10b is opened, for example, the movable valve 37 is attracted by the plunger 39 and the movable valve 37 collides with the plunger 39. Become. Therefore, for example, Teflon is also used for the portions where the movable valve 37 and the plunger 39 are in contact with each other to reduce the collision noise.
[0142]
As another impact mitigation means, the moving speed of the movable valve can be reduced to mitigate the impact caused by opening and closing the control valve. As shown in FIG. 30, springs 46 a and 46 b that are elastic bodies are disposed on the upper and lower portions of the movable valve 37. One end of the spring 46 a is connected to the valve seat 38 and the other end is connected to the movable valve 37. The spring 46a can reduce the speed at which the movable valve 37 moves downward and hits the valve seat 38 when the flow path is closed, so that the collision between the movable valve 37 and the valve seat 38 can be reduced. For this reason, wear of the movable valve 37 and the valve seat 38 can be suppressed, and the reliability of the opening / closing operation of the electromagnetic valves 10a and 10b can be improved, and the occurrence of collision noise can be reduced.
Further, one end of the spring 46 b disposed on the upper side is connected to the plunger 39 and the other end is connected to the movable valve 37. The spring 46b can reduce the speed at which the movable valve 37 moves upward and hits the plunger 39 when the flow path is opened. Therefore, in the event of a collision, the speed of the collision can be reduced by the spring 46 disposed at the top. Therefore, the collision between the movable valve 37 and the plunger 39 is eased. For this reason, wear of the movable valve 37 and the plunger 39 can be suppressed, and the reliability of the opening / closing operation of the electromagnetic valves 10a and 10b can be improved, and the occurrence of collision noise can be reduced.
Note that the end connected to the fixed side of the springs 46a and 46b is not limited to the above configuration, and may be connected anywhere on the fixed side in the control valve.
[0143]
reference Form 10.
The book reference As an example of the refrigeration air-conditioning apparatus according to the tenth embodiment, an apparatus that performs indoor air conditioning will be described. Figure 31 shows the book reference It is a refrigerant circuit figure which shows the structure of the refrigerating and air-conditioning apparatus by the form. In the figure, 47a is a pressure measuring means for measuring the high pressure of the refrigeration cycle, here a pressure sensor, 47b is a pressure measuring means for measuring the low pressure of the refrigeration cycle, here a pressure sensor, 48a and 48b are indoor heat exchangers 8a and 8b. The temperature measuring means for measuring the outlet temperature in the cooling operation of the air conditioner is here a temperature sensor, and 48c and 48d are the temperature measuring means for measuring the outlet temperature in the heating operation of the indoor heat exchangers 8a and 8b, and here are the temperature sensors. . In addition, the other structure of FIG. 31, the flow of a refrigerant | coolant, and the switching method of the capacity | capacitance of the compressor in FIG. 31 are the same as that of Embodiment 1. FIG.
[0144]
Book reference In this mode, as the operation information of the refrigeration cycle during operation, the high pressure, low pressure, the outlet temperature of the indoor heat exchangers 8a, 8b, and the like are measured by the pressure sensors 47a, 47b and the temperature sensors 48a, 48b, 48c, 48d. Based on the measured operation information, the control means (not shown) controls the operation capacity of the compressors 1a and 1b and the opening degree of the expansion valves 7a and 7b. The operation capacity control of the compressors 1a and 1b by the control means is the same as the method shown in the first embodiment. In the compressor 1a, the compressor 1a is set at different stages at each time allocated to the short-period time distribution. The average capacity in a short cycle is changed by changing the time distribution, and the operation capacity is continuously changed as a whole by combining the operation and stop of the compressor 1b. The opening degree of the expansion valves 7a and 7b is based on the low pressure (measured by the pressure sensor 47b) during the cooling operation and the outlet temperature of the indoor heat exchangers 8a and 8b (measured by the temperature sensors 48a and 48b) during the cooling operation. The degree of superheat at the outlet of the indoor heat exchanger is obtained, and control is performed so that the degree of superheat becomes a preset target value. In addition, during heating operation, high pressure (measured by the pressure sensor 47a) and supercooling at the outlet of the indoor heat exchanger based on the outlet temperature of the indoor heat exchangers 8a and 8b during heating operation (measured by the temperature sensors 48c and 48d). The degree of supercooling is calculated, and control is performed so that the degree of supercooling becomes a preset target value.
[0145]
Book reference The problem with this form is that the measured driving information tends to vary. That is, in the compressor 1a that can be operated with a stepped capacity, when the time control operation is performed and the capacity is switched stepwise in a short cycle, information on the pressure and temperature to be measured fluctuates. If control is performed based on this, stable control cannot be performed. FIG. 32 is an explanatory diagram showing a method for measuring operating information, for example, pressure, where the horizontal axis indicates time, and the vertical axis indicates the operating capacity of the compressor and the accompanying pressure. For example, when the compressor 1a is performing a time control operation in which the two stages of the maximum capacity and the minimum capacity are switched in a short cycle, when the compressor operation capacity changes from the minimum capacity to the maximum capacity, the high pressure is high and the low pressure is low. Conversely, when the compressor operating capacity changes from the maximum capacity to the minimum capacity, the high pressure is low and the low pressure is high.
[0146]
Book reference In this embodiment, the pressure and temperature are measured at the timing indicated by the dotted line in FIG. For example, the pressure and temperature are measured for a predetermined period of time at which the operating capacity of the compressor 1a is switched, i.e., at a fixed time interval shorter than the short cycle time, and an average value of a plurality of measured values measured during the period is obtained. Operation control is performed based on the average value. The average value of the obtained operation information is not affected by fluctuations caused by the time-controlled operation of the compressor 1a and can be ignored, so that stable operation control can be performed based on this operation information. Here, the predetermined period to be measured is not less than the length of the short cycle.
[0147]
In addition to obtaining the average value of a plurality of driving information measured as described above and carrying out the driving control, based on the maximum value among the plurality of measuring values measured during a predetermined period. Control may be performed, or control may be performed based on a minimum value among a plurality of measured values measured during a predetermined period. In addition, a plurality of measurement values may be arranged in order from large to small or from small to large, and control may be performed based on measurement values in a certain order. In any case, by controlling based on a plurality of operation information measured in a period of a short period or longer, it is possible to measure without fluctuation of operation information such as pressure and temperature, and to perform stable operation control. be able to.
[0148]
Then book reference Another method of measuring the operation information related to the refrigeration air conditioner according to the embodiment will be described. The pressure and temperature are measured at the timing indicated by the dotted lines in FIG. That is, the pressure and temperature are measured at approximately the intermediate timing between the time when the operating capacity of the compressor 1a is gradually switched from the minimum capacity to the maximum capacity and the time when the operating capacity is gradually switched from the maximum capacity to the minimum capacity. Also good. By measuring at such timing, information on pressure and temperature can be measured without the influence of fluctuation. In addition, when the measurement is performed at an intermediate timing within a short cycle, a value that is almost an average value of the fluctuating pressure can be measured even if the pressure fluctuates, so that it is possible to grasp the averaged state of the refrigeration cycle.
[0149]
In addition, the timing for measurement is not limited to approximately the middle of the time when the compressor operating capacity switches from the minimum capacity to the maximum capacity and the time when the compressor operates from the maximum capacity to the minimum capacity. It may be performed at a predetermined timing between the time for switching to the maximum capacity and the time for switching from the maximum capacity to the minimum capacity.
Even if the measurement is performed at a certain timing between the time when the operating capacity of the compressor is switched from the maximum capacity to the minimum capacity and the time when the capacity is switched from the minimum capacity to the maximum capacity, the operating information is similarly changed. Can be measured. That is, if measurement is performed at a predetermined time within a short period, operation information that is not affected by fluctuations can be obtained, and stable control can be performed by performing operation control based on this information. The predetermined time within the short cycle may be set in advance by confirming that it can be stably measured by experiments or the like.
In addition, even if it is not always measured at a predetermined time in the short cycle range, by grasping the characteristics of the fluctuation, for example, the fluctuation range in which the measured value fluctuates in the short cycle time and the range in advance by an experiment, If the measurement value can be corrected, it is not always necessary to measure at a predetermined time within a short period, and the measurement timing is not limited.
[0150]
Also, reference Form 3 of reference In Embodiment 10, the refrigeration and air-conditioning apparatus having the constant capacity compressor 1b in addition to the compressor 1a that can be operated in a stepwise capacity has been described. However, the configuration may not be such that the constant capacity compressor 1b is included. In addition, a configuration having a plurality of compressors 1b having a fixed capacity may be used, and a configuration having a plurality of compressors that can be operated at a stepped capacity as in the first embodiment is also used in each embodiment. Or reference form Has the same effect as. The refrigeration air conditioner may have one compressor that can be operated with at least a stepped capacity. In particular, by providing a plurality of compressors, the operation patterns can be combined in various ways, so that the combination range of operation capacities is expanded. Further, by providing a plurality of compressors that can be operated with a stepped capacity, the capacity fluctuation range can be reduced, which is more effective.
[0151]
In addition, Embodiments 1 to reference In Embodiment 10, the case of combining two indoor heat exchangers has been described, but the same effect can be obtained regardless of whether the number of indoor heat exchangers is one or three or more.
[0152]
In addition, Embodiments 1 to reference Also in the refrigerant used in the refrigeration air conditioner according to the tenth embodiment, not only R22 that is currently widely used in refrigeration air conditioners, but also R407C, R410A, which are HFC refrigerants such as R134a and R32, and mixed refrigerants of HFC refrigerants, Similar effects can be obtained by using R404A, natural refrigerants such as ammonia, propane and butane, and mixed refrigerants of these refrigerants.
[0153]
【The invention's effect】
According to the refrigerating and air-conditioning apparatus of the present invention, at least one compressor that can be operated at a stepped capacity, a compressor that can be operated at a stepped capacity separately from the compressor, or a compressor that operates at a constant capacity. A compressor capable of operating at a stepped capacity and operating at a different stage capacity for each time allocated to the short cycle time distribution, and changing the time distribution at the short cycle. By changing the average capacity of the compressor and making the overall operating capacity of the plurality of compressors continuously variable, there is no adverse effect of harmonics due to the use of the inverter, and fluctuations in the operating capacity of the compressor are reduced. Therefore, the fluctuation range on the refrigeration cycle, such as pressure fluctuation, is suppressed, the fluctuations in the refrigeration capacity and the air conditioning capacity such as the fluctuations in the blown air temperature are reduced, and the comfort of operating the refrigeration air conditioner can be ensured.
[0154]
According to the refrigerating and air-conditioning apparatus of the present invention, when the operation capacity of the plurality of compressors is shared by the compressors that can be operated with at least two stepped capacities, the compressor can be operated with the stepped capacities. Refrigeration cycle such as pressure fluctuations due to fluctuations in compressor operating capacity by sharing the operating capacity of the compressor with the minimum capacity of each stepped capacity of the compressor. The above fluctuation range is suppressed, fluctuations in the refrigerating capacity and air-conditioning capacity such as fluctuations in the blown air temperature are reduced, and the discharge temperature of the operating compressor can be made equal and stable operation can be achieved.
[0155]
According to the refrigerating and air-conditioning apparatus of the present invention, when each of the compressors that can be operated with at least two stepped capacities is operated with a different stage capacity at each time to which a short period of time distribution is allocated, The temporal variation of the total operating capacity of the machine within the short cycle is greater than the difference between the larger total operating capacity and the smaller total operating capacity of the compressors operating in the short period. The refrigeration cycle such as the pressure fluctuation accompanying the fluctuation of the operating capacity of the compressor is reduced by operating the combination of the short cycle time distribution of each compressor and the operating capacity of each hour so as to reduce the fluctuation of the operating capacity of the compressor. The above fluctuation range is suppressed, and fluctuations in the refrigeration capacity and the air conditioning capacity such as fluctuations in the blown air temperature are reduced, so that it is possible to ensure comfort when operating the refrigeration air conditioner.
[0156]
The refrigerating and air-conditioning apparatus according to the present invention includes two compressors that can be operated at a stepped capacity, and at least a part of the time during which one compressor operates at a larger capacity in that stage within a short period. At one time, the other compressor operates at the smaller capacity of the stage and at least part of the time at which the other compressor operates the larger capacity of the stage. Since the compressor is operated at the smaller capacity of the stage, the fluctuation of the compressor's operating capacity is reduced, and the fluctuation range on the refrigeration cycle such as the pressure fluctuation is suppressed. The effect of reducing the fluctuation of the refrigeration capacity and the air conditioning capacity, such as the fluctuation of the temperature, and ensuring the comfort during the operation of the refrigeration air conditioner.
[Brief description of the drawings]
FIG. 1 is a refrigerant circuit diagram showing a configuration of a refrigeration air conditioner according to Embodiment 1 of the present invention.
FIG. 2 is a sectional view showing a compression chamber of the scroll compressor according to the first embodiment.
3 is a plan view showing a compression chamber of the scroll compressor according to Embodiment 1. FIG.
FIG. 4 is an explanatory diagram showing a state of temporal opening / closing control of the solenoid valve according to the first embodiment.
FIG. 5 is a graph relating to the first embodiment, showing changes in the operating capacity of each compressor and showing the compressor operating capacity [HP] relative to the required operating capacity [HP].
FIG. 6 is a refrigerant circuit diagram showing a configuration of a refrigerating and air-conditioning apparatus according to Embodiment 2 of the present invention.
FIG. 7 is a graph relating to the second embodiment, showing an example of changes in the operating capacity of each compressor, and showing the compressor operating capacity [HP] with respect to the required operating capacity [HP].
FIG. 8 is a graph relating to the second embodiment, showing another example of changes in the operating capacity of each compressor, and showing the compressor operating capacity [HP] relative to the required operating capacity [HP].
FIG. 9 is a graph relating to the second embodiment, showing still another example of changes in the operating capacity of each compressor, and showing the compressor operating capacity [HP] relative to the required operating capacity [HP].
FIG. 10 is an explanatory diagram showing a change over time in the operating capacity of each compressor according to the second embodiment.
FIG. 11 is an explanatory diagram showing a change over time in the operating capacity of each compressor according to the second embodiment.
FIG. 12 is an explanatory diagram showing a change over time in the operating capacity of each compressor according to the second embodiment.
FIG. 13 shows the present invention. reference It is a refrigerant circuit figure which shows the structure of the freezing air conditioner by the form 3.
FIG. 14 reference 10 is a graph showing {volume of equipment and pipes constituting the high-pressure side (L)} / operation capacity fluctuation range [HP] with respect to the operation capacity control interval.
FIG. 15 reference 10 is a graph showing {volume of equipment and piping constituting low pressure side (L)} / operation capacity fluctuation range [HP] with respect to the operation capacity control interval.
FIG. 16 shows the present invention. reference It is a refrigerant circuit figure which shows the structure of the freezing air conditioner by the form 4.
FIG. 17 reference It is a refrigerant circuit figure which shows the other structure of the refrigerating air conditioner by the form 4.
FIG. 18 reference It is a refrigerant circuit figure which shows the further another structure of the refrigerating air conditioner by the form 4.
FIG. 19 shows the present invention. reference It is a refrigerant circuit figure which shows the structure of the refrigerating air conditioner by the form 5.
FIG. 20 reference It is a refrigerant circuit figure which shows the other structure of the refrigerating air conditioning apparatus by the form 5.
FIG. 21 shows the present invention. reference It is a refrigerant circuit figure which shows the structure of the refrigerating air conditioning apparatus by the form 6.
FIG. 22 reference It is a refrigerant circuit figure which shows the other structure of the refrigerating air conditioning apparatus by the form 6.
FIG. 23 reference It is a refrigerant circuit figure which shows the further another structure of the freezing air conditioner by the form 6.
FIG. 24 shows the present invention. reference It is a refrigerant circuit figure which shows the structure of the refrigerating air conditioner by the form 7 of.
FIG. 25 reference It is sectional drawing which shows the structure of the control valve concerning the form 7.
FIG. 26 reference It is a refrigerant circuit figure which shows the other structure of the refrigerating air conditioner by the form 7.
FIG. 27 reference It is a refrigerant circuit figure which shows the further another structure of the freezing air conditioner by the form 7.
FIG. 28 shows the present invention. reference It is a refrigerant circuit figure which shows the structure of the refrigerating air conditioner by the form 8.
FIG. 29 reference It is explanatory drawing which shows the other structure of the refrigerating air-conditioning apparatus by the form 8 of FIG. 29, (a) showed the structure when the outdoor unit was seen from the front, and (b) looked at the outdoor unit from the side. The structure of the hour is shown.
FIG. 30 shows the present invention. reference It is sectional drawing which shows the control valve concerning the refrigerating air conditioner by the form 9 of.
FIG. 31 of the present invention reference It is a refrigerant circuit figure which shows the structure of the refrigerating air conditioner by the form 10.
FIG. 32 reference It is explanatory drawing which shows the measuring method of the operating information of the refrigerating air conditioner concerning the form 10.
FIG. 33 reference It is explanatory drawing which shows the other measuring method of the operating information of the refrigerating air conditioner concerning the form 10.
FIG. 34 is a refrigerant circuit diagram showing a conventional air conditioner.
FIG. 35 is an explanatory diagram showing a state of temporal solenoid valve opening / closing control in a conventional air conditioner.
[Explanation of symbols]
1a, 1c Compressor capable of operating in stepwise capacity, 1b Compressor of constant capacity, 2a, 2b Discharge pipe, 3a, 3b Suction pipe, 4 Refrigerant flow path switching means, 5 First heat exchanger, 6 Liquid pipe 7, throttle means, 8a, 8b second heat exchanger, 9 gas pipe, 10a, 10b control valve, 16 high pressure side refrigerant container, 17 low pressure side refrigerant container, 18 oil separator, 19 oil return circuit, 30 liquid receiver , 31 Accumulator, 32, 33 Resistance element, 34 Bypass circuit, 35 Control valve, 36 Heat exchange part, 37 Movable valve, 38 Valve seat, 39 Plunger, 40 Coil, 41 Valve inlet side flow path, 42 Valve outlet side flow Road, 43 Cooling means, 44 Outdoor unit, 45 Machine room, 46a, 46b Deceleration means, 47a, 47b Pressure measuring means, 48a, 48b, 48c, 48d Temperature measuring means.

Claims (3)

At least one compressor that can be operated at a stepped capacity, and at least one compressor that can be operated at a stepped capacity or a compressor that operates at a constant capacity separately from the compressor, A compressor that can be operated with a small capacity is operated with a capacity of a different stage at each time to which a short period of time distribution is allocated, and the average capacity in the short period is changed by changing the time distribution, and a plurality of the above A refrigerating and air-conditioning apparatus that continuously varies the overall operating capacity of a compressor, and operates by sharing the operating capacity of a plurality of compressors with a compressor that can be operated with at least two stepped capacities In this case, the refrigeration and air-conditioning apparatus is characterized in that the operating capacity shared by the compressor capable of operating at the stepped capacity is shared while avoiding the coincidence with the minimum capacity among the stepped capacities of the compressor. . At least one compressor that can be operated at a stepped capacity, and at least one compressor that can be operated at a stepped capacity or a compressor that operates at a constant capacity separately from the compressor, Compressors that can be operated with a large capacity are operated at different stages of capacity at each time to which a short period of time distribution is allocated, and the average capacity in the short period is changed by changing the time distribution, and a plurality of the above A refrigerating and air-conditioning system that continuously varies the overall operating capacity of the compressor, each of the compressors that can be operated with at least two stepped capacities, each having a different time distribution with a short period of time distribution. When operating at the capacity of the compressor, the temporal variation of the total operating capacity of the compressors within the short cycle is smaller and the sum of the larger operating capacities of the compressors operating at the short cycle. Than the difference between the total operating capacity of So that fence, refrigerating and air-conditioning apparatus characterized by operating a combination of operating capacity of the time allocation of the short period of the compressors and their respective time. In Claim 2, two compressors that can be operated at a stepped capacity are provided, and within a short period, at least a part of the time during which one compressor operates at a larger capacity at that stage. At least part of the time during which the other compressor operates at the smaller capacity of the stage and the other compressor operates at the larger capacity of the stage. refrigeration air conditioning system, characterized in that to perform the operation of the smaller capacity of steps.

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