JP2008170118A - Heat pump type equipment - Google Patents

Abstract

The present invention proposes various modes for reducing the temperature of lubricating oil returning to a compressor, and provides a heat pump type equipment such as a hot water heater and a heater having high reliability and efficiency.
An oil separator (2) disposed between a compressor (1) constituting a refrigerant circuit and a high pressure side heat exchanger (3) for separating lubricating oil contained in refrigerant gas discharged from the compressor (1). The lubricating oil separated by the oil separator 2 is connected to the oil return circuit 10 for returning to the compressor 1 and the high pressure side heat exchanger 3, and heat exchange with the refrigerant passing through the high pressure side heat exchanger 3 is used. A heated fluid pipe 7 through which the fluid to be supplied flows, and a heat exchanger 8 for lubricating oil that exchanges heat between the lubricating oil passing through the oil return circuit 10 and the heated fluid flowing through the heated fluid pipe 7. Equipped with.
[Selection] Figure 1

Description

  The present invention relates to a heat pump type equipment such as a water heater and a heater.

  Refrigerant gas discharged from the compressor by providing an oil separator at the discharge port of the compressor with respect to the air conditioner in which the compressor, the high pressure side heat exchanger, the expansion device, and the low pressure side heat exchanger are sequentially connected by refrigerant piping There is one that separates the lubricating oil contained therein and returns it to the suction side of the compressor (for example, Patent Document 1).

Japanese Patent No. 292002

In the conventional air conditioner as described above, the oil separated by the oil separator and returned to the suction side of the compressor is high-temperature oil close to the discharge gas temperature. When high-temperature oil is sucked into the compressor, the suction gas expands due to overheating, so that there is a problem that the refrigerant circulation amount is reduced and efficiency is deteriorated.
In addition, the compressor motor is insufficiently cooled due to overheating of the suction gas, and the reliability is impaired.

In addition, some heat exchangers with the outside air are provided in the oil return path to the suction side to cool the oil return, but in that case there will be no malfunction due to overheating, but the discharged oil has Since heat energy is released to the outside air, energy loss occurs.
In addition, when a refrigerant circuit is configured without an oil separator, the lubricating oil discharged together with the refrigerant from the compressor stays in the high-pressure side heat exchanger and the low-pressure side heat exchanger, reducing the heat exchange efficiency. Or the amount of lubricating oil inside the compressor is reduced and reliability is impaired.

  The present invention has been made to solve the above-described problems, and proposes various modes for lowering the temperature of the lubricating oil that returns to the compressor, and has a highly reliable and efficient water heater and heating system. It aims at providing heat pump type equipment such as a machine.

The present invention is a heat pump type equipment having a refrigerant circuit in which a compressor, a high-pressure side heat exchanger, an expansion device, and a low-pressure side heat exchanger are sequentially connected via a refrigerant pipe, and the compression of the refrigerant circuit An oil separator that is disposed between a compressor and the high-pressure side heat exchanger and separates the lubricating oil contained in the refrigerant gas discharged from the compressor; and the lubricating oil separated by the oil separator For the lubricating oil that exchanges heat between the oil returning circuit that returns oil to the compressor and the lubricating oil that is provided in the middle of the oil returning circuit and that passes through the oil returning circuit and the fluid to be heated for use. And a heat exchanger.
For example, it is connected to the high-pressure side heat exchanger and includes a heated fluid pipe through which the heated fluid that exchanges heat with the refrigerant passing through the high-pressure side heat exchanger. Heat exchange is performed between the lubricating oil passing through the oil return circuit and the heated fluid passing through the heated fluid piping.
Further, the fluid to be heated is a refrigerant between the expansion device and the low-pressure side heat exchanger among the refrigerants flowing through the refrigerant circuit, and the heat exchanger for lubricating oil passes through the oil return circuit. It arrange | positions so that heat exchange may be performed between lubricating oil and the refrigerant | coolant which exists between the said expansion device and the said low voltage | pressure side heat exchanger.
Alternatively, the heat exchanger for lubricating oil is arranged so as to exchange heat between the lubricating oil passing through the oil return circuit and the air as the fluid to be heated sent to the room.

The heat pump type equipment according to the present invention is provided in the oil return circuit for returning the lubricating oil separated by the oil separator to the compressor, and the lubricating oil provided in the middle of the oil return circuit and used through the oil return circuit. Since the lubricating oil heat exchanger for exchanging heat with the heated fluid to be supplied is provided, the lubricating oil returns to the compressor after being cooled. Therefore, the compressor intake gas is not overheated and expanded, and a reduction in heat exchange efficiency and a reduction in reliability due to overheating can be prevented.
Further, since the lubricating oil separated by the oil separator heats the fluid to be heated (water or air) to be used, it is useful for effective use of the lubricating oil.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram showing the overall configuration of a heat pump facility device according to Embodiment 1 of the present invention. As shown in FIG. 1, this heat pump type equipment includes a compressor 1, an oil separator (oil separator) 2, a high pressure side heat exchanger 3, an expansion device (expansion valve etc.) 4, and a low pressure side heat exchanger 5. And a refrigerant circuit sequentially connected through the refrigerant pipe 6. The high pressure side heat exchanger 2 is connected to a heated fluid pipe 7 through which heated fluid (water, air, etc.) that is used after being exchanged with the refrigerant in the refrigerant circuit flows. A heat exchanger 8 for lubricating oil that heats the fluid to be heated is disposed in the middle of the fluid to be heated 7 (here, in the middle of the input side to the high-pressure side heat exchanger 3).

  Further, the lubricating oil separated by the oil separator 2 is passed through the lubricating oil heat exchanger 8 and is exchanged with the fluid to be heated by the lubricating oil heat exchanger 8, and then returned to the suction pipe 1 </ b> A of the compressor 1. An oil return circuit 10 is provided. A capillary tube 11 as a throttle mechanism is provided between the lubricating oil heat exchanger 8 of the oil return circuit 10 and the compressor 1.

Next, operation | movement of the heat pump type equipment of Embodiment 1 is demonstrated. The high-temperature refrigerant compressed by the compressor 1 is separated from the lubricating oil by the oil separator 2 and then enters the high-pressure side heat exchanger 3. In the high pressure side heat exchanger 3, the refrigerant is cooled by exchanging heat with the heated fluid supplied from the heated fluid pipe 7, and then enters the low pressure side heat exchanger (evaporator) 5 through the expansion device 4. . In the low pressure side heat exchanger 5, the refrigerant exchanges heat with air, is gasified, and returns to the compressor 1. Due to this action, the heated fluid flowing through the heated fluid pipe 7 is heated, so that this heat pump type equipment can be used as a water heater or a heating device.
The lubricating oil separated by the oil separator 2 is cooled by exchanging heat with the fluid to be heated by the lubricating oil heat exchanger 8 and then returned to the compressor 1 through the oil return circuit 10. For this reason, the intake gas of the compressor 1 is not overheated and can be prevented from being reduced in efficiency and reliability due to overheating.
Moreover, since the lubricating oil separated by the oil separator 2 is used for heat exchange with the fluid to be heated to heat it, it is excellent in energy efficiency without wasting heat.

As the oil separator (oil separator) 2 used in the apparatus of FIG. 1, a mesh is provided inside the container, and the oil separator contained in the refrigerant gas is separated, or the refrigerant flow is swirled inside the container, A so-called centrifugal type that separates oil by the centrifugal force can be used.
Further, as the throttle mechanism 11, a so-called capillary tube having a function of controlling the amount of oil returned from the oil separator 2 to the compressor, an electronic expansion valve, or the like can be used. The electronic expansion valve has an advantage that the throttle opening degree can be set according to the changing amount of oil discharged depending on the operating conditions.
The lubricating oil heat exchanger 8 is a so-called plate heat exchanger, double pipe heat exchanger, or a type in which heat is exchanged by closely connecting a pipe through which a fluid to be heated flows and a pipe through which oil flows. Etc. are available.

Embodiment 2. FIG.
FIG. 2 is a block diagram showing the overall configuration of the heat pump facility equipment according to Embodiment 2 of the present invention. As shown in FIG. 2, this heat pump type equipment includes a compressor 1, an oil separator (oil separator) 2, a high-pressure side heat exchanger 3, an expansion device (such as an expansion valve) 4, and a low-pressure side heat exchanger 5. And a refrigerant circuit sequentially connected through the refrigerant pipe 6. The high pressure side heat exchanger 2 has a heated fluid pipe (in the second embodiment, simply a fluid pipe) through which a heated fluid (simply referred to as a fluid in the second embodiment) that exchanges heat with the refrigerant in the refrigerant circuit flows. 7) is connected. A lubricating oil heat exchanger 8 is disposed between the expansion device 4 of the refrigerant circuit and the low pressure side heat exchanger 5. Further, the lubricating oil separated by the oil separator 2 is passed through the lubricating oil heat exchanger 8, and the lubricating oil heat exchanger 8 exchanges heat with the refrigerant passing therethrough before returning to the suction pipe 1 A of the compressor 1. An oil return circuit 10 for oiling is provided. A capillary tube 11 is provided between the lubricating oil heat exchanger 8 of the oil return circuit 10 and the compressor 1.

Next, operation | movement of the heat pump type equipment of Embodiment 2 is demonstrated. The high-temperature refrigerant compressed by the compressor 1 is separated from the lubricating oil by the oil separator 2 and then enters the high-pressure side heat exchanger 3. In the high-pressure side heat exchanger 3, the refrigerant exchanges heat with the fluid supplied from the fluid pipe 7 and is cooled, and then enters the low-pressure side heat exchanger (evaporator) 5 through the expansion device 4. In the low pressure side heat exchanger 5, the refrigerant exchanges heat with air, is gasified, and returns to the compressor 1. Due to this action, the fluid flowing through the fluid piping 7 is heated, so that the heat pump type equipment can be used as a water heater or a heating device.
The lubricating oil separated by the oil separator 2 is cooled by exchanging heat with the refrigerant cooled by the expansion device 4 and the heat exchanger 8 for lubricating oil, and then passed through the oil return circuit 10 and then the compressor 1. Return to. For this reason, the intake gas of the compressor 1 is not overheated and can be prevented from being reduced in efficiency and reliability due to overheating.

  In FIG. 2, in the high-pressure side heat exchanger 3, heat is exchanged between the refrigerant and the fluid flowing through the fluid pipe 7. However, the refrigerant pipe 7 is connected to the high-pressure side heat exchanger 3 without connecting the fluid pipe 7. It is good also as a structure which heat-exchanges between the surrounding air. In that case, the high-pressure side heat exchanger 3 can be used as an indoor unit of an air conditioner, for example.

Embodiment 3 FIG.
In the first and second embodiments described above, the lubricating oil is returned to the suction pipe 1A of the compressor 1. Here, the compressor 1 is a scroll compressor, and the oil separator 2 separates the lubricating oil. The case where the lubricating oil is directly returned to the compression mechanism of the scroll compressor will be described. First, the scroll compressor used in the third embodiment will be briefly described.

FIG. 3 is a cross-sectional view showing an example of a compression mechanism portion of the scroll compressor 20. In FIG. 3, 21 is a sealed container, 22 is a frame formed in the sealed container 21, 23 is a fixed scroll fixed on the frame 2, and 24 is combined with a motor fixed scroll 23 and revolved by a drive shaft. An orbiting scroll 25 is a plurality of compression chambers formed between the laps of the scrolls 23 and 24.
Reference numeral 26 denotes a suction port formed on the wall surface of the sealed container 21 at a position facing the gas suction portion of the compression chamber 25. Reference numeral 27 denotes a fixed scroll 23 which is formed in the sealed container 21 from the innermost peripheral compression chamber 25. Reference numeral 28 denotes an oil injection port that communicates with the compression chamber 25. The high-pressure gas discharged into the sealed container 21 is sent out of the sealed container 21 from a discharge pipe (not shown).

FIG. 4 is a block diagram showing the overall configuration of a heat pump facility device according to Embodiment 3 of the present invention using the scroll compressor 20 as a compressor. As can be seen from FIG. 4, the difference between the third embodiment and the first embodiment is that the oil return circuit 10 is connected not to the suction pipe 1A of the compressor 1 but to the oil injection port 28 of the scroll compressor 20. It is a point. Other configurations may be basically the same as those in the first embodiment.
According to the configuration of the third embodiment, since the cooled lubricating oil is directly injected into the compression chamber 25 of the scroll compressor 20 via the oil return circuit 10, the sealing performance of the compression chamber 25 is improved and the compression efficiency is increased. Can be up.

Further, as shown in FIG. 5, the oil return circuit 10 is branched into two, one of which is connected to the suction port 26 of the scroll compressor 20 and the other is connected to the oil injection port 28 of the scroll compressor 20. Alternatively, a part or all of the oil from the oil return circuit 10 may be returned to each port using a flow rate adjusting valve or the like. Each branched oil return circuit 10 is provided with capillary tubes 11 and 12.
If the amount of lubricating oil supplied to the compression chamber 25 is too small, a minute gap in the compression chamber 25 cannot be sealed with oil, and internal leakage increases and efficiency decreases. On the other hand, if too much lubricating oil is supplied to the compression chamber 25, there may be a problem that the oil is compressed to cause abnormal pressure increase. However, in the embodiment shown in FIG. 5, the oil return circuit 10 is branched into two and returned to the compressor 1, so that the amount of lubricating oil flowing into the compression chamber 25 can be adjusted, and the above-described problems occur. Appropriate settings that do not occur are possible.

  The idea of the third embodiment shown in FIGS. 4 and 5 can be applied not only to the first embodiment but also to the second embodiment and further to a fourth embodiment to be described later.

Embodiment 4 FIG.
FIG. 6 is a block diagram showing the overall configuration of the heat pump facility equipment according to Embodiment 4 of the present invention. As shown in FIG. 6, this heat pump type equipment includes a compressor 1, an oil separator (oil separator) 2, a high-pressure side heat exchanger 3, a throttling device (such as an expansion valve) 4, and a low-pressure side heat exchanger 5. And a refrigerant circuit sequentially connected through the refrigerant pipe 6. Also here, there is provided an oil return circuit 10 for returning the lubricating oil separated by the oil separator 2 to the compressor 1. And the heat exchanger 8 for lubricating oil arrange | positioned so that heat exchange may be performed between the lubricating oil which passes the oil return circuit 10, and the air which is sent indoors and uses for heating is high pressure side heat exchanger 3 is arranged in series. Further, the lubricating oil heat exchanger 8 and the high pressure side heat exchanger 3 are respectively provided with corresponding blower fans 14.

Next, the operation of the heat pump type equipment of the fourth embodiment will be described. The high-temperature refrigerant compressed by the compressor 1 is separated from the lubricating oil by the oil separator 2 and then enters the high-pressure side heat exchanger 3. In the high-pressure side heat exchanger 3, the refrigerant exchanges heat with the air sent into the room via the blower fan 14, and then enters the low-pressure side heat exchanger (evaporator) 5 through the expansion device 4. In the low pressure side heat exchanger 5, the refrigerant exchanges heat with air, is gasified, and returns to the compressor 1. Due to this action, the heated air that has been heat-exchanged with the refrigerant in the high-pressure side heat exchanger 3 is supplied to the room as warm air for heating.
In addition, also in the heat exchanger 8 for lubricating oil, the high-temperature lubricating oil flowing therethrough is cooled by the compressor 1 after exchanging heat with air sent to the room via the blower fan 14. By this action, the heated air that has been heat-exchanged with the lubricating oil in the lubricating oil heat exchanger 8 is supplied to the room as warm air for heating.
Thus, the heat pump type equipment of the fourth embodiment can be used as an extremely efficient heater.
On the other hand, the lubricating oil separated by the oil separator 2 is cooled by heat exchange with the heated air in the lubricating oil heat exchanger 8, and then returns to the compressor 1 through the oil return circuit 10. For this reason, the intake gas of the compressor 1 is not overheated and can be prevented from being reduced in efficiency and reliability due to overheating.

  In each embodiment, the high-pressure side heat exchanger 3 and the lubricating oil heat exchanger 8 are configured separately, but may be configured integrally as necessary.

The block diagram of the heat pump type equipment which concerns on Embodiment 1 of this invention. The block diagram of the heat pump type equipment which concerns on Embodiment 2 of this invention. Sectional drawing which shows an example of the compression mechanism part of a scroll compressor. The block diagram of the heat pump type equipment which concerns on Embodiment 3 of this invention. The block diagram of the heat pump type equipment which changed a part of FIG. The block diagram of the heat pump type equipment which concerns on Embodiment 4 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Compressor, 1A Intake pipe, 2 Oil separator, 3 High pressure side heat exchanger, 4 Throttle device, 5 Low pressure side heat exchanger, 6 Refrigerant piping, 7 Heated fluid piping, 8 Lubricating oil heat exchanger, 10 Oil return circuit, 11, 12 Capillary tube, 14 Blower fan, 20 Scroll compressor, 21 Airtight container, 22 Frame, 23 Fixed scroll, 24 Swing scroll, 25 Compression chamber, 26 Suction port, 27 Discharge port, 28 Oil injection port.

Claims (6)

A heat pump type equipment having a refrigerant circuit in which a compressor, a high-pressure side heat exchanger, an expansion device, and a low-pressure side heat exchanger are sequentially connected via a refrigerant pipe,
An oil separator that is disposed between the compressor of the refrigerant circuit and the high-pressure side heat exchanger, and separates lubricating oil contained in the refrigerant gas discharged from the compressor;
An oil return circuit for returning the lubricating oil separated by the oil separator to the compressor;
A heat exchanger for lubricating oil that is provided in the middle of the oil return circuit and performs heat exchange between the lubricating oil passing through the oil return circuit and the fluid to be heated to be used;
A heat pump type facility device characterized by comprising: A heated fluid pipe connected to the high pressure side heat exchanger and through which the heated fluid exchanged with the refrigerant passing through the high pressure side heat exchanger flows;
The heat exchanger for lubricating oil is arranged so as to exchange heat between the lubricating oil passing through the oil return circuit and the heated fluid passing through the heated fluid piping. Item 2. The heat pump type equipment according to Item 1. The fluid to be heated is a refrigerant between the expansion device and the low-pressure side heat exchanger among the refrigerant flowing through the refrigerant circuit,
The lubricating oil heat exchanger is arranged to exchange heat between the lubricating oil passing through the oil return circuit and a refrigerant between the expansion device and the low pressure side heat exchanger. The heat pump type equipment according to claim 1.   The heat pump type equipment according to claim 3, further comprising a fluid pipe connected to the high-pressure side heat exchanger and through which a fluid that exchanges heat with a refrigerant passing through the high-pressure side heat exchanger flows.   The heat exchanger for lubricating oil is arranged so as to exchange heat between the lubricating oil passing through the oil return circuit and air as the heated fluid sent to the room. Item 2. The heat pump type equipment according to Item 1.   The compressor is a scroll compressor, and a part or all of the oil from the oil return circuit is returned to the oil injection port provided in the compression mechanism of the scroll compressor. The heat pump type equipment according to any one of claims 1 to 5.

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