[go: up one dir, main page]

WO2018198345A1 - Exhaust gas purification device - Google Patents

Exhaust gas purification device Download PDF

Info

Publication number
WO2018198345A1
WO2018198345A1 PCT/JP2017/017027 JP2017017027W WO2018198345A1 WO 2018198345 A1 WO2018198345 A1 WO 2018198345A1 JP 2017017027 W JP2017017027 W JP 2017017027W WO 2018198345 A1 WO2018198345 A1 WO 2018198345A1
Authority
WO
WIPO (PCT)
Prior art keywords
exhaust gas
downstream
upstream
flow path
diffusion portion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2017/017027
Other languages
French (fr)
Japanese (ja)
Inventor
勇人 相澤
知秀 高屋
佑 江原
智美 浦濱
森　仁志
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tokyo Roki Co Ltd
Original Assignee
Tokyo Roki Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tokyo Roki Co Ltd filed Critical Tokyo Roki Co Ltd
Priority to PCT/JP2017/017027 priority Critical patent/WO2018198345A1/en
Priority to JP2019515046A priority patent/JP6771099B2/en
Publication of WO2018198345A1 publication Critical patent/WO2018198345A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/24—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
    • F01N3/28—Construction of catalytic reactors
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Definitions

  • the exhaust gas purified by passing through the SCRs 31 and 32 and the NH 3 slip 33 is air formed between the inner wall of the casing 4 and the first and second flow passages 2 and 3 including the communication part 5. It flows out of the casing 4 (that is, the exhaust emission control device 1) through the layer X (arrow L10 shown by the broken line in FIGS. 1 and 2).

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

In this exhaust gas purification device 1, a first flow passage, which communicates with an exhaust gas flow inlet GI and has a DOC and a DPF, and a second flow passage 3, which has SCRs 31,32, are disposed in a folded-back manner via a communication part 5, the communication part comprising: an upstream-side diffusion part 52 in which a dosing part 51 is disposed on the upstream side; a downstream-side diffusion part 54 in which the second flow passage 3 is disposed on the downstream side; and a connection part 53 which establishes communication between the upstream-side diffusion part 52 and the downstream-side diffusion part 54. Due to this configuration, elongation of the overall device can be prevented while ensuring the distance between the dosing part 51 and the SCR 31, sufficient mixing of the exhaust gas with a reducing agent can be achieved, and the exhaust gas purification efficiency can be improved.

Description

排気浄化装置Exhaust purification device

　本発明は排気浄化装置に関し、特にディーゼルエンジンから排出される排気ガスを浄化する排気浄化装置に好適なものである。 The present invention relates to an exhaust purification device, and is particularly suitable for an exhaust purification device that purifies exhaust gas discharged from a diesel engine.

　内燃機関（例えば、ディーゼルエンジン）から排出された排気ガスには、有害物質である粒子状物質（ＰＭ）及び窒素酸化物（ＮＯｘ）が含まれている。そのため、内燃機関から排出された排気ガスを浄化して、当該排気ガスからＰＭ及びＮＯｘを除去または低減しておくことが要請されている。このような要請を実現するために、各種の開発が行われており、近年では、ＤＰＦシステムと尿素ＳＣＲシステムとを組み合わせた排気浄化装置も開発され、実用化されるに至っている。このような排気浄化装置では、ＤＰＦシステムと尿素ＳＣＲシステムとの間に還元剤供給部が設けられている（例えば、特許文献１，２参照）。 Exhaust gas discharged from an internal combustion engine (for example, a diesel engine) contains particulate matter (PM) and nitrogen oxides (NOx), which are harmful substances. Therefore, it is required to purify the exhaust gas discharged from the internal combustion engine and remove or reduce PM and NOx from the exhaust gas. Various developments have been made in order to realize such a demand, and in recent years, an exhaust gas purification apparatus combining a DPF system and a urea SCR system has been developed and put into practical use. In such an exhaust purification device, a reducing agent supply unit is provided between the DPF system and the urea SCR system (see, for example, Patent Documents 1 and 2).

　ここで、ＤＰＦシステムは、排気ガスからＰＭを除去または低減するための装置であり、内燃機関（ディーゼルエンジン）から排出される排気ガス中のＮＯｘを酸化するための酸化触媒（ＤＯＣ：Diesel Oxidation Catalyst）及び、排気ガス中のＰＭを捕集し、燃焼（酸化）除去するためのパティキュレートフィルタ(ＤＰＦ：Diesel Particulate Filter)を備えたものである。また、尿素ＳＣＲシステムは、ＮＯｘとアンモニアとの選択還元反応を利用して、排気ガスからＮＯｘを除去または低減するための装置であり、ＮＯｘを還元剤と接触させて還元除去するための選択還元触媒（ＳＣＲ：Selective Catalytic Reduction）及びアンモニアスリップ触媒を備えたものである。 Here, the DPF system is a device for removing or reducing PM from exhaust gas, and an oxidation catalyst (DOC: Diesel Oxidation Catalyst for oxidizing NOx in exhaust gas discharged from an internal combustion engine (diesel engine). ) And a particulate filter (DPF: Diesel Particulate Filter) for collecting and burning (oxidizing) PM in the exhaust gas. The urea SCR system is a device for removing or reducing NOx from exhaust gas using a selective reduction reaction between NOx and ammonia, and selective reduction for reducing and removing NOx in contact with a reducing agent. A catalyst (SCR: Selective Catalytic Reduction) and an ammonia slip catalyst are provided.

特表２００２－５０２９２７号公報Japanese translation of PCT publication No. 2002-502927 ＥＰ０７５８７１３Ａ１号公報EP0758713A1 publication

　ところで、特許文献１，２に係る排気浄化装置にあっては、還元剤供給部とＳＣＲとの距離が長いほど、還元剤（例えば、尿素、アンモニア等）と排気ガスとの混合が促進して、排気ガスの浄化効率が向上することとなる。従って、かかる装置にあっては、両者の距離を長くしておくことが望ましい。 By the way, in the exhaust gas purification apparatus according to Patent Documents 1 and 2, the longer the distance between the reducing agent supply unit and the SCR, the more the mixing of the reducing agent (for example, urea, ammonia, etc.) and the exhaust gas is promoted. As a result, the exhaust gas purification efficiency is improved. Therefore, in such a device, it is desirable to increase the distance between the two.

　しかしながら、従来の装置の如く、ＤＯＣ，ＤＰＦ，ＳＣＲ及びアンモニアスリップ触媒が直列に収納されたままの状態で、還元剤供給部とＳＣＲとの距離を長くした場合には、装置全体が長尺化してしまう。そして、このように装置全体が長尺化してしまうと、車輌への搭載が困難になる等の問題が生じることとなる。 However, when the distance between the reducing agent supply unit and the SCR is increased with the DOC, DPF, SCR and ammonia slip catalyst being accommodated in series as in the conventional apparatus, the entire apparatus becomes longer. End up. If the entire apparatus becomes long in this way, problems such as difficulty in mounting on the vehicle arise.

　そこで、本発明は、このような事情に鑑みてなされたものであり、還元剤供給部と選択還元触媒との距離を確保しつつ装置全体の長尺化を防止でき、還元剤と排気ガスとを十分に混合させ、排気ガスの浄化効率を向上することが可能な排気浄化装置を提供することを目的とする。 Therefore, the present invention has been made in view of such circumstances, and can prevent the entire apparatus from being elongated while ensuring the distance between the reducing agent supply unit and the selective reduction catalyst. It is an object of the present invention to provide an exhaust purification device capable of sufficiently mixing the gas and improving the exhaust gas purification efficiency.

　上記課題を解決するために、本発明に係る排気浄化装置は、
　内燃機関から排出された排気ガスを浄化する排気浄化装置であって、
　前記排気ガスの流入口と連通する第一流通路と、
　前記第一流通路と連通する第二流通路と、
　これら第一及び第二流通路を収容し、任意の位置に前記排気ガスの排出口が設けられるケーシングと、を備え、
　前記第一流通路は、
　前記排気ガス中の窒素酸化物を酸化するための酸化触媒と、
　前記酸化触媒の下流側に配置され、前記排気ガス中の微粒子成分を捕集して除去するためのパティキュレートフィルタと、を有し、
　前記第二流通路は、
　前記窒素酸化物を尿素成分またはアンモニア成分から選ばれる還元剤と接触させて還元除去するための選択還元触媒を有し、
　前記第一流通路と前記第二流通路とが、連通部を介して接続されており、
　前記連通部は、
　上流側に前記還元剤を供給するための還元剤噴霧部が配置される上流側拡散部と、
　下流側に前記第二流通路が配置される下流側拡散部と、
　前記上流側拡散部及び前記下流側拡散部を連通する接続部と、を備え、
　前記上流側拡散部に対し、前記下流側拡散部が、前記接続部を介して折り返された形状で配置されることを特徴とする。 In order to solve the above problems, an exhaust emission control device according to the present invention includes:
An exhaust purification device for purifying exhaust gas discharged from an internal combustion engine,
A first flow path communicating with the exhaust gas inlet;
A second flow path communicating with the first flow path;
A casing in which the first and second flow passages are accommodated and the exhaust gas discharge port is provided at an arbitrary position;
The first flow path is
An oxidation catalyst for oxidizing nitrogen oxides in the exhaust gas;
A particulate filter disposed on the downstream side of the oxidation catalyst for collecting and removing particulate components in the exhaust gas,
The second flow path is
A selective reduction catalyst for reducing and removing the nitrogen oxide by contacting with a reducing agent selected from a urea component or an ammonia component;
The first flow path and the second flow path are connected via a communication part,
The communication part is
An upstream diffusion part in which a reducing agent spraying part for supplying the reducing agent to the upstream side is disposed;
A downstream diffusion portion in which the second flow passage is disposed on the downstream side;
A connecting portion communicating the upstream diffusion portion and the downstream diffusion portion, and
The downstream diffusion portion is arranged in a shape folded through the connection portion with respect to the upstream diffusion portion.

　このとき、本発明に係る排気浄化装置において、前記上流側拡散部の断面積は、前記下流側拡散部の断面積よりも大きく形成されていることが望ましい。 At this time, in the exhaust emission control device according to the present invention, it is preferable that a cross-sectional area of the upstream diffusion portion is larger than a cross-sectional area of the downstream diffusion portion.

　本発明によれば、還元剤供給部と選択還元触媒との距離を確保しつつ装置全体の長尺化を防止でき、還元剤と排気ガスとを十分に混合させ、排気ガスの浄化効率を向上することが可能な排気浄化装置を提供できる。 According to the present invention, it is possible to prevent the entire apparatus from being lengthened while ensuring the distance between the reducing agent supply unit and the selective reduction catalyst, and to sufficiently mix the reducing agent and the exhaust gas, thereby improving the exhaust gas purification efficiency. It is possible to provide an exhaust emission control device that can be used.

本実施形態に係る排気浄化装置を部分的に透視して示す概略斜視図である。1 is a schematic perspective view showing an exhaust gas purification apparatus according to the present embodiment partially through. 図１の排気浄化装置における排気ガスの流れの説明に供する断面図である。It is sectional drawing with which it uses for description of the flow of the exhaust gas in the exhaust gas purification apparatus of FIG. 図１の排気浄化装置を示す平面図である。It is a top view which shows the exhaust gas purification apparatus of FIG. 図１の排気浄化装置を示す下面図である。It is a bottom view which shows the exhaust gas purification apparatus of FIG. 図３の排気浄化装置を紙面右方向から見て示す側面図である。FIG. 4 is a side view showing the exhaust emission control device of FIG. 3 as viewed from the right side of the drawing. 図３の排気浄化装置を紙面左方向から見て示す側面図である。FIG. 4 is a side view showing the exhaust purification device of FIG. 3 as viewed from the left side of the drawing. 図１の排気浄化装置を示す正面図である。It is a front view which shows the exhaust gas purification apparatus of FIG. 図６の排気浄化装置におけるＡ－Ａ矢視の断面を示す断面図である。FIG. 7 is a cross-sectional view showing a cross section taken along line AA in the exhaust emission control device of FIG. 6. 図６の排気浄化装置におけるＢ－Ｂ矢視の断面を示す断面図である。FIG. 7 is a cross-sectional view showing a cross section taken along line BB in the exhaust emission control device of FIG. 6. 図５の排気浄化装置におけるＣ－Ｃ矢視の断面を示す断面図である。FIG. 6 is a cross-sectional view showing a cross section taken along the line CC in the exhaust emission control device of FIG. 5. 図６の排気浄化装置におけるＤ－Ｄ矢視の断面を示す断面図である。FIG. 7 is a cross-sectional view showing a cross section taken along the arrow DD in the exhaust emission control device of FIG. 6. 図６の排気浄化装置におけるＥ－Ｅ矢視の断面を示す断面図である。FIG. 7 is a cross-sectional view showing a cross section taken along the line EE in the exhaust emission control device of FIG. 6. 還元剤噴霧後の排気ガスの流速分布を示し、（ａ）は従来構造での排気ガスの流速分布を示し、（ｂ）は本実施形態での排気ガスの流速分布を示す図である。FIG. 6 shows the exhaust gas flow velocity distribution after spraying the reducing agent, (a) shows the exhaust gas flow velocity distribution in the conventional structure, and (b) shows the exhaust gas flow velocity distribution in the present embodiment. 還元剤の濃度分布を示し、（ａ）は上流側と下流側の拡散流通路が同一径の場合における還元剤の濃度分布を示し、（ｂ）は上流側の拡散流通路の方が下流側の拡散流通路より径が大きい場合における還元剤の濃度分布を示す図である。The concentration distribution of the reducing agent is shown, (a) shows the concentration distribution of the reducing agent when the upstream and downstream diffusion flow passages have the same diameter, and (b) shows the upstream diffusion flow passage on the downstream side. It is a figure which shows the density | concentration distribution of a reducing agent in case a diameter is larger than this diffusion flow path. 噴霧した還元剤の流通路壁面への付着状態を平面側から見て示し、（ａ）は従来構造での付着状態を示し、（ｂ）は本実施形態での付着状態を示す図である。The adhesion state of the sprayed reducing agent on the flow passage wall surface is shown from the plane side, (a) shows the adhesion state in the conventional structure, and (b) shows the adhesion state in the present embodiment. 噴霧した還元剤の流通路壁面への付着状態を側面側から見て示し、（ａ）は従来構造での付着状態を示し、（ｂ）は本実施形態での付着状態を示す図である。The adhesion state of the sprayed reducing agent on the flow passage wall surface is shown as viewed from the side, (a) shows the attachment state in the conventional structure, and (b) shows the attachment state in the present embodiment.

　以下、図面を参照しながら本発明に係る排気浄化装置の実施形態について説明する。但し、以下に述べる実施形態には、本発明を実施するために技術的に好ましい種々の限定が付されているが、本発明の範囲を以下の実施形態および図示例に限定するものではない。 Hereinafter, embodiments of an exhaust emission control device according to the present invention will be described with reference to the drawings. However, the embodiments described below are provided with various technically preferable limitations for carrying out the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

＜排気浄化装置の構成＞
　図１～図１２に示すように、本実施形態の排気浄化装置１は、不図示の内燃機関（この場合、ディーゼルエンジン）から排出された排気ガスの流入口ＧＩと連通する第一流通路２と、第一流通路２と連通する第二流通路３と、これら第一及び第二流通路２，３を収容する略箱型のケーシング４と、を備えている。なお、本実施形態の場合、第一及び第二流通路２，３は、それぞれ円筒形状をなしているが、本発明はこれに限ることはない。また、ケーシング４における排気ガスの排出口ＧＯは、搭載する車両等に応じて任意の位置に設けることができる。 <Configuration of exhaust purification device>
As shown in FIGS. 1 to 12, the exhaust emission control device 1 of the present embodiment includes a first flow passage 2 that communicates with an inflow port GI of exhaust gas discharged from an internal combustion engine (in this case, a diesel engine) (not shown). , A second flow passage 3 communicating with the first flow passage 2, and a substantially box-shaped casing 4 accommodating the first and second flow passages 2, 3. In the present embodiment, the first and second flow passages 2 and 3 each have a cylindrical shape, but the present invention is not limited to this. Further, the exhaust gas outlet GO in the casing 4 can be provided at an arbitrary position according to the vehicle to be mounted.

　図１，図２に示すように、第一流通路２には、排気ガス中の窒素酸化物（ＮＯｘ）を酸化するための酸化触媒（ＤＯＣ）２１と、ＤＯＣ２１の下流側に配置され、排気ガス中の微粒子成分（ＰＭ）を捕集して除去するためのパティキュレートフィルタ（ＤＰＦ）２２と、が設置されている。第一流通路２におけるＤＯＣ２１の上流側には、後述する上流側導入部２０が配設されている。上流側導入部２０は、流入口ＧＩから流入する排気ガスをＤＯＣ２１の直径方向に拡散させるためのものである。 As shown in FIGS. 1 and 2, the first flow passage 2 is disposed on the downstream side of the DOC 21 and an oxidation catalyst (DOC) 21 for oxidizing nitrogen oxide (NOx) in the exhaust gas. A particulate filter (DPF) 22 for collecting and removing the particulate component (PM) therein is installed. On the upstream side of the DOC 21 in the first flow passage 2, an upstream introduction portion 20 described later is disposed. The upstream introduction part 20 is for diffusing exhaust gas flowing in from the inlet GI in the diameter direction of the DOC 21.

　図１，図２，図８に示すように、第二流通路３には、窒素酸化物（ＮＯｘ）を尿素成分またはアンモニア成分から選ばれる還元剤と接触させて還元除去するための選択還元触媒（ＳＣＲ）３１，３２が設置されている。なお、本実施形態では、ＳＣＲ３１，３２を二段構成で設ける場合について述べるが、本発明はこれに限らない。また、下流側のＳＣＲ３２の更に下流側には、ＳＣＲ３２から排出される還元剤を酸化するための新たな酸化触媒であるＮＨ3スリップ３３が配置されていることが好ましい。これにより、ＳＣＲ３１，３２において排気ガスと反応しきれずに排出される（スリップする）還元剤を確実に酸化させ、スリップ現象を未然に防止できる。但し、本発明において、ＮＨ3スリップ３３は必須ではなく、ＮＨ3スリップ３３を省略してもよい。 As shown in FIGS. 1, 2, and 8, the second flow passage 3 has a selective reduction catalyst for reducing and removing nitrogen oxides (NOx) by contacting with a reducing agent selected from a urea component or an ammonia component. (SCR) 31 and 32 are installed. In the present embodiment, the case where the SCRs 31 and 32 are provided in a two-stage configuration will be described, but the present invention is not limited to this. Further, it is preferable that an NH 3 slip 33 as a new oxidation catalyst for oxidizing the reducing agent discharged from the SCR 32 is disposed further downstream of the downstream SCR 32. As a result, the reducing agent discharged (slips) without being completely reacted with the exhaust gas in the SCRs 31 and 32 can be reliably oxidized, and the slip phenomenon can be prevented. However, in the present invention, the NH 3 slip 33 is not essential, and the NH 3 slip 33 may be omitted.

　図１に示すように、第一流通路２と第二流通路３は、それらの断面がケーシング４の側壁断面における対角方向に並ぶように、互いに平行に配置されている。より具体的には、当該側壁断面の相互に対向する略角部にそれぞれ配置されている。また、第一流通路２と第二流通路３は、還元剤を供給するための還元剤噴霧部であるドージング５１が設けられた連通部５を介して接続されている。 As shown in FIG. 1, the first flow passage 2 and the second flow passage 3 are arranged in parallel to each other so that their cross sections are aligned in a diagonal direction in the side wall cross section of the casing 4. More specifically, they are arranged at substantially corners facing each other in the side wall cross section. Moreover, the 1st flow path 2 and the 2nd flow path 3 are connected via the communication part 5 provided with the dosing 51 which is a reducing agent spray part for supplying a reducing agent.

　図１，図２，図８に示すように、連通部５は、全体として略Ｕ字状の形状をなし、第一流通路２のＤＰＦ２２と連通するドージング５１と、このドージング５１と連通する上流側拡散部５２と、上流側拡散部５２の下流側に接続されて流通路を１８０°折り返す接続部５３と、接続部５３に接続され、上流側拡散部５２と略平行な下流側拡散部５４と、下流側拡散部５４と第二流通路３のＳＣＲ３１とを連通する下流側導入部５５と、を備えている。また、ＤＰＦ２２の下流側端部の外周には、排気ガスをドージング５１へと排出するための開口部２２ａが設けられている。 As shown in FIGS. 1, 2, and 8, the communication portion 5 has a substantially U-shape as a whole, a dosing 51 that communicates with the DPF 22 of the first flow passage 2, and an upstream side that communicates with the dosing 51. A diffusion part 52; a connection part 53 connected to the downstream side of the upstream diffusion part 52 and turning back the flow path by 180 °; a downstream diffusion part 54 connected to the connection part 53 and substantially parallel to the upstream diffusion part 52; The downstream side diffusion portion 54 and the downstream side introduction portion 55 that communicates with the SCR 31 of the second flow passage 3 are provided. An opening 22 a for exhaust gas exhaust to the dosing 51 is provided on the outer periphery of the downstream end of the DPF 22.

　このように、本実施形態では、第一流通路２と第二流通路３とが連通部５によって略Ｓ字状に接続されている。これにより、図１３（ａ）に示す従来の排気浄化装置の場合と比較して、図１３（ｂ）に示すように、第一流通路２と第二流通路３とを、並べて配置した場合においても、排気浄化装置１の全長を大きくすることなく、ドージング５１とＳＣＲ３１との間の流通路の長さを稼ぐことができる。換言すれば、ドージング５１とＳＣＲ３１との距離を確保しつつ、装置全体の長尺化を防止できる。よって、従来の排気浄化装置の場合に比して、連通部５における排気ガスの流速を速めることができ、ドージング５１において噴霧された還元剤と排気ガスとを十分に混合させ、排気ガスの浄化効率を向上できる。 Thus, in the present embodiment, the first flow passage 2 and the second flow passage 3 are connected in a substantially S shape by the communication portion 5. Thereby, in comparison with the case of the conventional exhaust purification device shown in FIG. 13A, as shown in FIG. 13B, the first flow passage 2 and the second flow passage 3 are arranged side by side. However, the length of the flow path between the dosing 51 and the SCR 31 can be increased without increasing the overall length of the exhaust gas purification device 1. In other words, the overall length of the apparatus can be prevented while securing the distance between the dosing 51 and the SCR 31. Therefore, the exhaust gas flow rate in the communication portion 5 can be increased as compared with the case of the conventional exhaust purification device, and the reducing agent sprayed in the dosing 51 and the exhaust gas are sufficiently mixed to purify the exhaust gas. Efficiency can be improved.

　第一流通路２の導入部２０は、図９，図１０に示すように、第一流通路２に対して側方から排気ガスを流入するパイプ状の流入口ＧＩと、ＤＯＣ２１の排気ガス流入側端面を覆う張出部２０ｂと、を有している。また、導入部２０は、流入口ＧＩから張出部２０ｂにおけるＤＯＣ２１側の接続端部２０ａに向けて、当該ＤＯＣ２１の外周における直径近傍の位置まで広がった形状をなしている。さらに、張出部２０ｂは、ＤＯＣ２１と対向する部位が、ＤＯＣ２１側とは反対側（つまり、ケーシング４の外方側）に向けて膨らんだ形状をなしている。なお、ケーシング４の張出部２０ｂと対応する部位は、当該張出部２０ｂを覆うように外方へと膨らんだ形状をなしている。また、導入部２０は、内部にＤＯＣ２１の外径に沿った（この場合、円筒状の）邪魔板２０１が設けられている。この邪魔板２０１は、その流入口ＧＩ側に面した一面が、パンチング孔２０１ａを多数穿設されたパンチングメタルとして構成されている。これにより、第一流通路２に対して側方に配置された流入口ＧＩから流入した排気ガスを、邪魔板２０１のパンチング孔２０１ａを通過する経路（図１０の矢印Ｌ１ａ）と、邪魔板２０１を乗り越える経路（図１０の矢印Ｌ１ｂ）とに流通させることで、ＤＯＣ２１の直径方向に均一に拡散させることができる。 As shown in FIGS. 9 and 10, the introduction portion 20 of the first flow passage 2 includes a pipe-like inlet GI through which exhaust gas flows into the first flow passage 2 from the side, and an exhaust gas inflow side end surface of the DOC 21. And an overhanging portion 20b covering the. The introduction part 20 has a shape that extends from the inflow port GI to the connection end part 20a on the DOC 21 side in the overhang part 20b to a position near the diameter on the outer periphery of the DOC 21. Furthermore, the projecting portion 20b has a shape in which a portion facing the DOC 21 swells toward the side opposite to the DOC 21 side (that is, the outer side of the casing 4). In addition, the site | part corresponding to the overhang | projection part 20b of the casing 4 has comprised the shape bulging outward so that the said overhang | projection part 20b may be covered. Further, the introduction unit 20 is provided with a baffle plate 201 (in this case, cylindrical) along the outer diameter of the DOC 21. The baffle plate 201 is configured as a punching metal having one surface facing the inlet GI side having a number of punching holes 201a. As a result, the exhaust gas flowing in from the inlet GI disposed on the side of the first flow passage 2 passes through the punching hole 201a of the baffle plate 201 (arrow L1a in FIG. 10) and the baffle plate 201. By distributing it over the route (arrow L1b in FIG. 10), it can be uniformly diffused in the diameter direction of the DOC 21.

　このような構成の排気浄化装置１において、ケーシング４の内壁と、連通部５を含む第一及び第二流通路２，３との間には空間が形成されており、この空間がＤＯＣ２１，ＤＰＦ２２，ＳＣＲ２１，３２等の触媒を断熱（保温）するための空気層Ｘとして機能するようになっている。そして、本実施形態では、第二流通路３から排出される排気ガスが空気層Ｘを流通しつつ、排出口ＧＯから排出されるようになっている。 In the exhaust emission control device 1 having such a configuration, a space is formed between the inner wall of the casing 4 and the first and second flow passages 2 and 3 including the communication portion 5, and this space is formed by the DOC 21 and the DPF 22. , SCR21, 32, etc., function as an air layer X for heat insulation (heat insulation). In the present embodiment, the exhaust gas discharged from the second flow passage 3 is discharged from the discharge port GO while flowing through the air layer X.

　ここで、本実施形態の排気浄化装置１の場合、上流側拡散部５２の断面積は、下流側拡散部５４の断面積よりも大きく形成されていることが望ましい。具体的に、本実施形態の場合、上流側拡散部５２の断面積、すなわち、上流側拡散部５２の径をφ１３０とし、下流側拡散部５４の断面積、すなわち、下流側拡散部５４の径をφ１２０とした。図１４（ａ）に示すように、上流側及び下流側拡散部５２，５４が同一径（共にφ１２０）の場合（以下、これを前者と称す）における下流側拡散部５４の還元剤（ＮＨ3）の濃度分布と比較し、図１４（ｂ）に示すように、上流側拡散部５２の径（φ１３０）が下流側拡散部５４の径（φ１２０）より大きい場合（以下、これを後者と称す）における下流側拡散部５４の還元剤（ＮＨ3）の濃度分布の方が濃く、より混合していることがわかる。 Here, in the exhaust purification device 1 of the present embodiment, it is desirable that the cross-sectional area of the upstream diffusion portion 52 is formed larger than the cross-sectional area of the downstream diffusion portion 54. Specifically, in the case of this embodiment, the cross-sectional area of the upstream diffusion portion 52, that is, the diameter of the upstream diffusion portion 52 is φ130, and the cross-sectional area of the downstream diffusion portion 54, that is, the diameter of the downstream diffusion portion 54. Was set to φ120. As shown in FIG. 14A, the reducing agent (NH 3 ) of the downstream diffusion section 54 when the upstream and downstream diffusion sections 52 and 54 have the same diameter (both are φ120) (hereinafter referred to as the former). 14), the diameter (φ130) of the upstream diffusion portion 52 is larger than the diameter (φ120) of the downstream diffusion portion 54 (hereinafter, this will be referred to as the latter). It can be seen that the concentration distribution of the reducing agent (NH 3 ) in the downstream diffusion section 54 in FIG.

　これは、図１５及び図１６に示すように、前者の場合には、ドージング５１から噴霧された還元剤の一部が上流側拡散部５２の内壁面に付着している（図１５（ａ）及び図１６（ａ）参照）のに対し、後者の場合には、そのような上流側拡散部５２の内壁面への付着は見られない（図１５（ｂ）及び図１６（ｂ）参照）。つまり、後者の場合、上流側拡散部５２における排気ガスの流速を遅くすることで、その内壁面への付着を回避でき、局所的な（還元剤の）液膜の偏りを分散化し、排気ガスに対して還元剤をより効果的に混合させることができるためであることがわかった。 As shown in FIGS. 15 and 16, in the former case, part of the reducing agent sprayed from the dosing 51 is attached to the inner wall surface of the upstream diffusion portion 52 (FIG. 15A). 16 (a) and FIG. 16 (a)), in the latter case, such adhesion to the inner wall surface of the upstream diffusion portion 52 is not seen (see FIG. 15 (b) and FIG. 16 (b)). . That is, in the latter case, by slowing the flow rate of the exhaust gas in the upstream diffusion section 52, it is possible to avoid adhesion to the inner wall surface, disperse local (reducing agent) liquid film bias, and exhaust gas. It was found that this is because the reducing agent can be mixed more effectively.

＜排気ガスと尿素水の流れ＞
　次に、排気浄化装置１の内部における排気ガスと還元剤（例えば、尿素水）の流れについて説明する。
　ディーゼルエンジンから排出された排気ガスは、流入口ＧＩから排気浄化装置１の内部に流入し（図１の矢印Ｌ１）、第一流通路２に配置されたＤＯＣ２１及びＤＰＦ２２を通過する（図１０の矢印Ｌ２，Ｌ３）。排気ガス中に含まれていたＮＯｘは、ＤＯＣ２１で酸化されてＮＯ2となる。また、排気ガス中に含まれていたＰＭは、ＤＰＦ２２で捕集されて排気ガスから除去される。そして、ＤＯＣ２１及びＤＰＦ２２を通過した排気ガスに対し、ドージング５１から尿素水が噴射供給される。このドージング５１から噴射供給された尿素水は、略Ｕ字状に折り返された連通部５の上流側拡散部５２，接続部５３，下流側拡散部５４において、下方の開口部２２ａを介して上流側拡散部５２へ流入されるＤＰＦ２２通過後の排気ガス流（図８，図１０の矢印Ｌ３）によって、連通部５の内壁面に沿った旋回流を形成しながら流れる（図２，図８の矢印Ｌ４）。つまり、ＤＯＣ２１及びＤＰＦ２２を通過した排気ガスは、連通部５付近を通過する際に、旋回流を形成した尿素水と攪拌混合される。その際、尿素水と攪拌混合された排気ガスは、接続部５３付近で旋回しながら強制的に流れ方向を変えられ下流側拡散部５４において均一に分散された状態となる。 <Flow of exhaust gas and urea water>
Next, the flow of exhaust gas and reducing agent (for example, urea water) in the exhaust purification apparatus 1 will be described.
Exhaust gas discharged from the diesel engine flows into the exhaust purification device 1 from the inlet GI (arrow L1 in FIG. 1), and passes through the DOC 21 and DPF 22 arranged in the first flow passage 2 (arrow in FIG. 10). L2, L3). NOx contained in the exhaust gas is oxidized by the DOC 21 to become NO 2 . Further, PM contained in the exhaust gas is collected by the DPF 22 and removed from the exhaust gas. Then, urea water is injected and supplied from the dosing 51 to the exhaust gas that has passed through the DOC 21 and the DPF 22. The urea water injected and supplied from the dosing 51 is upstream through the lower opening 22a in the upstream diffusion portion 52, the connection portion 53, and the downstream diffusion portion 54 of the communication portion 5 folded back in a substantially U shape. The exhaust gas flow after passing through the DPF 22 (arrow L3 in FIGS. 8 and 10) flowing into the side diffusion portion 52 flows while forming a swirl flow along the inner wall surface of the communication portion 5 (FIGS. 2 and 8). Arrow L4). That is, the exhaust gas that has passed through the DOC 21 and the DPF 22 is stirred and mixed with the urea water that has formed a swirling flow when passing through the vicinity of the communicating portion 5. At that time, the exhaust gas stirred and mixed with the urea water is forced to change its flow direction while swirling in the vicinity of the connection portion 53 and is uniformly dispersed in the downstream diffusion portion 54.

　そして、この排気ガスは、下流側導入部５５の壁面で堰き止められた後、旋回しながら第二流通路３のＳＣＲ３１に流入し（図２，図８の矢印Ｌ５，Ｌ６）、均一に分散された状態でＳＣＲ３２及びＮＨ3スリップ３３を通過する（図２，図８の矢印Ｌ７）。なお、排気ガス中に含まれていたＮＯｘ（ＮＯ2を含む）は、ＳＣＲ３１，３２で還元浄化されてＮ2となる。また、ＳＣＲ３１，３２で消費されずに排気ガス中に残存する尿素水及びＮＨ3は、ＮＨ3スリップ３３で吸着されて排気ガスから除去され、若しくはＮＨ3スリップ３３で酸化浄化されてＮ2となる。そして、ＳＣＲ３１，３２及びＮＨ3スリップ３３を通過して浄化された排気ガスは、ケーシング４の内壁と、連通部５を含む第一及び第二流通路２，３との間に形成された空気層Ｘを介して（図１，図２の破線で示す矢印Ｌ１０）、ケーシング４（すなわち、排気浄化装置１）の外部に流出する。 The exhaust gas is blocked by the wall surface of the downstream introduction portion 55, and then flows into the SCR 31 of the second flow passage 3 while turning (arrows L5 and L6 in FIGS. 2 and 8), and is uniformly dispersed. In this state, it passes through the SCR 32 and the NH 3 slip 33 (arrow L7 in FIGS. 2 and 8). Note that NOx (including NO 2 ) contained in the exhaust gas is reduced and purified by the SCRs 31 and 32 to become N 2 . In addition, urea water and NH 3 remaining in the exhaust gas without being consumed by the SCRs 31 and 32 are adsorbed by the NH 3 slip 33 and removed from the exhaust gas, or oxidized and purified by the NH 3 slip 33 to form N 2 . Become. The exhaust gas purified by passing through the SCRs 31 and 32 and the NH 3 slip 33 is air formed between the inner wall of the casing 4 and the first and second flow passages 2 and 3 including the communication part 5. It flows out of the casing 4 (that is, the exhaust emission control device 1) through the layer X (arrow L10 shown by the broken line in FIGS. 1 and 2).

　以上の通り、本実施形態にあっては、排気ガスの流入口ＧＩと連通し、ＤＯＣ２１とＤＰＦ２２とを有する第一流通路２と、ＳＣＲ３１，３２を有する第二流通路３とが、上流側にドージング５１が配置される上流側拡散部５２と、下流側に第二流通路３が配置される下流側拡散部５４と、これら拡散部５２，５４を連通する接続部５３と、を備えた連通部５を介して折り返された形状で配置される。このため、ドージング５１とＳＣＲ３１との距離を確保しつつ装置全体の長尺化を防止でき、還元剤と排気ガスとを十分に混合させ、排気ガスの浄化効率を向上することができる。 As described above, in the present embodiment, the first flow passage 2 having the DOC 21 and the DPF 22 and the second flow passage 3 having the SCRs 31 and 32 communicated with the exhaust gas inlet GI are disposed upstream. Communication provided with an upstream diffusion part 52 in which the dosing 51 is arranged, a downstream diffusion part 54 in which the second flow passage 3 is arranged on the downstream side, and a connection part 53 that connects these diffusion parts 52 and 54. It arrange | positions in the shape turned up via the part 5. FIG. For this reason, it is possible to prevent the entire apparatus from being lengthened while securing the distance between the dosing 51 and the SCR 31, and to sufficiently mix the reducing agent and the exhaust gas, thereby improving the exhaust gas purification efficiency.

　このとき、上流側拡散部５２の断面積を、下流側拡散部５４の断面積よりも大きく形成することにより、上流側拡散部５２における排気ガスの流速を遅くすることで、上流側拡散部５２の内壁面に対する還元剤の付着を回避でき、局所的な（還元剤の）液膜の偏りを分散化し、排気ガスに対して還元剤をより効果的に混合させることができる。 At this time, by forming the cross-sectional area of the upstream diffusion portion 52 to be larger than the cross-sectional area of the downstream diffusion portion 54, the flow rate of the exhaust gas in the upstream diffusion portion 52 is reduced, so that the upstream diffusion portion 52. It is possible to avoid the attachment of the reducing agent to the inner wall surface, to disperse the local (reducing agent) liquid film, and to mix the reducing agent more effectively with the exhaust gas.

　１…排気浄化装置
　２…第一流通路
　２０…上流側導入部
　２０ａ…接続端部
　２０ｂ…張出部
　２０１…邪魔板
　２０１ａ…パンチング孔
　２１…ＤＯＣ（酸化触媒）
　２２…ＤＰＦ（燃焼フィルタ）
　３…第二流通路
　３１，３２…ＳＣＲ（選択還元触媒）
　３３…ＮＨ3スリップ（新たな酸化触媒）
　４…ケーシング
　４ａ…挿通孔
　５…連通部
　５１…ドージング
　５２…上流側拡散部
　５３…接続部
　５４…下流側拡散部
　５５…下流側導入部
　ＧＩ…排気ガスの流入口
　ＧＯ…排気ガスの排出口 DESCRIPTION OF SYMBOLS 1 ... Exhaust gas purification apparatus 2 ... 1st flow path 20 ... Upstream side introduction part 20a ... Connection end part 20b ... Overhang part 201 ... Baffle plate 201a ... Punching hole 21 ... DOC (oxidation catalyst)
22 ... DPF (combustion filter)
3. Second flow path 31, 32 ... SCR (selective reduction catalyst)
33 ... NH 3 slip (new oxidation catalyst)
DESCRIPTION OF SYMBOLS 4 ... Casing 4a ... Insertion hole 5 ... Communication part 51 ... Dosing 52 ... Upstream side diffusion part 53 ... Connection part 54 ... Downstream side diffusion part 55 ... Downstream side introduction part GI ... Exhaust gas inflow port GO ... Exhaust gas discharge port

Claims (2)

　内燃機関から排出された排気ガスを浄化する排気浄化装置であって、
　前記排気ガスの流入口と連通する第一流通路と、
　前記第一流通路と連通する第二流通路と、
　これら第一及び第二流通路を収容し、任意の位置に前記排気ガスの排出口が設けられるケーシングと、を備え、
　前記第一流通路は、
　前記排気ガス中の窒素酸化物を酸化するための酸化触媒と、
　前記酸化触媒の下流側に配置され、前記排気ガス中の微粒子成分を捕集して除去するためのパティキュレートフィルタと、を有し、
　前記第二流通路は、
　前記窒素酸化物を尿素成分またはアンモニア成分から選ばれる還元剤と接触させて還元除去するための選択還元触媒を有し、
　前記第一流通路と前記第二流通路とが、連通部を介して接続されており、
　前記連通部は、
　上流側に前記還元剤を供給するための還元剤噴霧部が配置される上流側拡散部と、
　下流側に前記第二流通路が配置される下流側拡散部と、
　前記上流側拡散部及び前記下流側拡散部を連通する接続部と、を備え、
　前記上流側拡散部に対し、前記下流側拡散部が、前記接続部を介して折り返された形状で配置される
　ことを特徴とする排気浄化装置。 An exhaust purification device for purifying exhaust gas discharged from an internal combustion engine,
A first flow path communicating with the exhaust gas inlet;
A second flow path communicating with the first flow path;
A casing in which the first and second flow passages are accommodated and the exhaust gas discharge port is provided at an arbitrary position;
The first flow path is
An oxidation catalyst for oxidizing nitrogen oxides in the exhaust gas;
A particulate filter disposed on the downstream side of the oxidation catalyst for collecting and removing particulate components in the exhaust gas,
The second flow path is
A selective reduction catalyst for reducing and removing the nitrogen oxide by contacting with a reducing agent selected from a urea component or an ammonia component;
The first flow path and the second flow path are connected via a communication part,
The communication part is
An upstream diffusion part in which a reducing agent spraying part for supplying the reducing agent to the upstream side is disposed;
A downstream diffusion portion in which the second flow passage is disposed on the downstream side;
A connecting portion communicating the upstream diffusion portion and the downstream diffusion portion, and
The exhaust gas purification apparatus, wherein the downstream diffusion portion is arranged in a shape folded through the connection portion with respect to the upstream diffusion portion. 　前記前記上流側拡散部の断面積は、前記下流側拡散部の断面積よりも大きく形成されている
　ことを特徴とする請求項１に記載の排気浄化装置。 2. The exhaust emission control device according to claim 1, wherein a cross-sectional area of the upstream diffusion portion is formed larger than a cross-sectional area of the downstream diffusion portion.
PCT/JP2017/017027 2017-04-28 2017-04-28 Exhaust gas purification device Ceased WO2018198345A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/JP2017/017027 WO2018198345A1 (en) 2017-04-28 2017-04-28 Exhaust gas purification device
JP2019515046A JP6771099B2 (en) 2017-04-28 2017-04-28 Exhaust purification device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2017/017027 WO2018198345A1 (en) 2017-04-28 2017-04-28 Exhaust gas purification device

Publications (1)

Publication Number Publication Date
WO2018198345A1 true WO2018198345A1 (en) 2018-11-01

Family

ID=63918150

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2017/017027 Ceased WO2018198345A1 (en) 2017-04-28 2017-04-28 Exhaust gas purification device

Country Status (2)

Country Link
JP (1) JP6771099B2 (en)
WO (1) WO2018198345A1 (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100242450A1 (en) * 2009-03-26 2010-09-30 Marcus Werni Exhaust gas-treating device
JP2015068341A (en) * 2013-09-27 2015-04-13 エーバーシュペッヒャー・エグゾースト・テクノロジー・ゲーエムベーハー・ウント・コンパニー・カーゲー Exhaust gas treatment device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100242450A1 (en) * 2009-03-26 2010-09-30 Marcus Werni Exhaust gas-treating device
JP2015068341A (en) * 2013-09-27 2015-04-13 エーバーシュペッヒャー・エグゾースト・テクノロジー・ゲーエムベーハー・ウント・コンパニー・カーゲー Exhaust gas treatment device

Also Published As

Publication number Publication date
JP6771099B2 (en) 2020-10-21
JPWO2018198345A1 (en) 2020-01-16

Similar Documents

Publication Publication Date Title
US11110406B2 (en) Dosing and mixing arrangement for use in exhaust aftertreatment
US9062589B2 (en) Reductant aqueous solution mixing device and exhaust aftertreatment device provided with the same
US8991160B2 (en) Reductant aqueous solution mixing device and exhaust aftertreatment device provided with the same
US9458750B2 (en) Integrated exhaust treatment device having compact configuration
EP3279440B1 (en) Exhaust purification unit
JP2013142368A (en) Exhaust emission control device
JPWO2008111254A1 (en) Exhaust gas purification device for internal combustion engine
JP2012122469A (en) Dosing module for exhaust gas aftertreatment system of vehicle
US10030560B2 (en) Exhaust purification device
US8443595B2 (en) Additive-agent diffusion plate in exhaust passage, structure of additive-agent diffusion plate, and exhaust system including additive-agent diffusion plate
JP2009250218A (en) Urea injection device
JP2007198316A (en) Device and method for controlling exhaust gas of internal combustion engine
JP5057944B2 (en) Exhaust aftertreatment device
JP2016188579A (en) Exhaust emission control unit
JP6756629B2 (en) Exhaust gas purification device
WO2014192183A1 (en) Exhaust gas purification device
JP6636907B2 (en) Exhaust gas purification device
JP2017214884A (en) Exhaust emission control system
JP2016205188A (en) Exhaust purification unit
CN106894870B (en) Engine exhaust aftertreatment device
JP2015209799A (en) Internal combustion engine exhaust emission control system
JP6771099B2 (en) Exhaust purification device
US10603641B2 (en) Diesel exhaust fluid mixing body using variable cross-section switchback arrangement
JP6745401B2 (en) Exhaust purification device
WO2018082381A1 (en) Box-type exhaust aftertreatment device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17907386

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2019515046

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 17907386

Country of ref document: EP

Kind code of ref document: A1