JP2006071197A - Heat pump device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump device capable of reducing flow noise caused by a constitution of a bypass circuit allowing a part of gas refrigerant of high temperature/high pressure discharged from a compressor to diverge in a defrosting operation or the like with a simple constitution and a structure preferable in view point of space saving and weight saving. <P>SOLUTION: In this heat pump device having the compressor 2 for compressing refrigerant, a four-way valve 3 connected with a discharge side of the compressor 2, and switching the flow of refrigerant in cooling and heating, an outdoor heat exchanger 4 to which the refrigerant is supplied from the compressor 2 through the four-way valve 3 in cooling, an indoor heat exchanger 5 to which the refrigerant is supplied form the compressor 2 through the four-way valve 3 in heating, an outdoor expansion valve 6 mounted between the outdoor heat exchanger 4 and the indoor heat exchanger 5, and a high-pressure refrigerant bypass circuit 20 for allowing a part of the refrigerant discharged from the compressor 2 to diverge and merge with the refrigerant in piping 14 between the outdoor heat exchanger 4 and the outdoor expansion valve 6, a pressure loss part 30 (mesh filter 31) is mounted on the high-pressure refrigerant bypass circuit 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat pump device that circulates refrigerant by a compressor driven by a drive source such as an engine or a motor, and performs cooling and heating.

Conventionally, in a heat pump device for circulating and cooling a refrigerant by a compressor driven by a drive source such as an engine or a motor to perform air conditioning such as a building or a large capacity space, for defrost operation, etc. Some have a bypass circuit for branching a part of the high-temperature and high-pressure gas refrigerant discharged from the compressor and introducing it into the outdoor heat exchanger. In other words, the bypass circuit is provided with opening / closing means such as a solenoid valve, and at the time of defrost operation, the opening / closing means is opened to branch a part of the high-temperature and high-pressure gas refrigerant discharged from the compressor to the bypass circuit. Then, the branched refrigerant is combined with the refrigerant flowing into the outdoor heat exchanger to raise the temperature and pressure of the refrigerant, and the frost adhering to the outdoor heat exchanger is melted and removed by continuing the heating operation ( For example, see Patent Document 1.) Such a bypass circuit is also used to prevent excessive refrigerant supply to an outdoor heat exchanger or an indoor heat exchanger that may cause malfunction of the heat pump device. That is, when reducing the refrigerant discharge amount from the compressor to prevent excessive refrigerant supply to the outdoor heat exchanger or the indoor heat exchanger, the engine as the drive source of the compressor is operated at a low speed. Therefore, a part of the refrigerant discharged from the compressor is branched by a bypass circuit to adjust the amount of refrigerant supplied to the indoor heat exchanger and the outdoor heat exchanger.
JP-A-8-121915

  However, in the bypass circuit as described above, a gas refrigerant having a high pressure and a high flow velocity flows, so that an air flow sound that is a high-frequency sound generated when a gas having a high flow velocity passes through a thin pipe is generated. Such airflow noise may be annoying for some users, so it is desired to be reduced. Therefore, as a measure for reducing such airflow noise, a silencer having an expansion chamber is interposed in a bypass circuit to mute by the expansion ratio, and such a silencer is effective in absorbing high-frequency components. A method of providing a sound-absorbing material that can be considered. However, when these methods are adopted, the structure becomes complicated and the manufacturing cost increases. In addition, in order to obtain a sufficient airflow noise reduction effect by the silencer, the tube diameter may increase, and the configuration is such that each device / device is housed in a single package and space is limited. The heat pump apparatus is not preferable from the viewpoint of space saving and weight reduction.

  Therefore, the problem to be solved by the present invention is a simple structure and a high-temperature / high-pressure gas refrigerant discharged from the compressor at the time of defrost operation or the like by a preferable structure from the viewpoint of space saving and weight reduction. The object is to provide a heat pump device capable of reducing airflow noise caused by a bypass circuit configuration for partially branching.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, in claim 1, a compressor that obtains power from a drive source and compresses the refrigerant, a four-way valve that is connected to the discharge side of the compressor and switches the flow of the refrigerant during cooling and heating, and during cooling An outdoor heat exchanger to which refrigerant is supplied from the compressor via the four-way valve, an indoor heat exchanger to which refrigerant is supplied from the compressor via the four-way valve during heating, the outdoor heat exchanger, and An outdoor expansion valve disposed between the indoor heat exchangers and a high pressure that branches a part of refrigerant discharged from the compressor and joins the refrigerant in the pipe between the outdoor heat exchanger and the outdoor expansion valve. In the heat pump device having a refrigerant bypass circuit, a pressure loss portion is provided in the high-pressure refrigerant bypass circuit.

  According to a second aspect of the present invention, in the heat pump device according to the first aspect, the pressure loss part is provided downstream of a throttle part provided in the high-pressure refrigerant bypass circuit.

  According to a third aspect of the present invention, in the heat pump device according to the first or second aspect, the pressure loss portion is constituted by a mesh filter.

  As effects of the present invention, the following effects can be obtained.

  In claim 1, the pressure loss in the high-pressure refrigerant bypass circuit increases, a part of the energy of the high-temperature / high-pressure gas refrigerant is lost, and the flow rate of the gas refrigerant passing through the high-pressure refrigerant bypass circuit can be reduced. The pressure difference between the refrigerant from the high-pressure refrigerant bypass circuit and the refrigerant in the pipe between the outdoor heat exchanger and the outdoor expansion valve can be alleviated, and airflow noise generated in the high-pressure refrigerant bypass circuit can be reduced.

  According to the second aspect of the present invention, it is possible to increase the pressure loss with respect to the gas refrigerant whose flow velocity is increased at the throttle portion, and it is possible to reduce the airflow noise generated in the bypass circuit having the throttle portion.

  According to the third aspect of the present invention, air flow noise generated in the high-pressure refrigerant bypass circuit can be reduced with a simple structure and a structure preferable from the viewpoint of space saving and weight reduction.

Next, embodiments of the invention will be described with reference to the drawings.
FIG. 1 is a refrigerant circuit diagram of a heat pump device according to the present invention, FIG. 2 is a partial sectional view showing a mesh filter constituting a pressure loss part, and FIG. 3 is a perspective view showing an interposed state of the mesh filter.

First, the refrigerant circuit configuration in the heat pump apparatus according to the present invention will be described with reference to FIG. The refrigerant circuit configuration shown by the refrigerant circuit diagram of FIG. 1 is an example of the refrigerant circuit configuration of the heat pump device according to the present invention, and is not limited to this configuration.
A heat pump device according to the present invention includes a compressor 2 that obtains power from an engine 1 as a drive source and compresses refrigerant, and a four-way valve that is connected to the discharge side of the compressor 2 and switches the refrigerant flow during cooling and heating. 3, an outdoor heat exchanger 4 to which refrigerant is supplied from the compressor 2 through the four-way valve 3 during cooling, and an indoor heat exchanger 5 to which refrigerant is supplied from the compressor 2 through the four-way valve 3 during heating The outdoor expansion valve 6 disposed between the outdoor heat exchanger 4 and the indoor heat exchanger 5 is used, and a refrigerant cycle constituted by these is used. On the discharge side of the compressor 2, a part of the refrigerant discharged from the compressor 2 is branched to join the refrigerant in the pipe between the outdoor heat exchanger 4 and the outdoor expansion valve 6 ( (Hereinafter referred to as “bypass circuit”) 20 is configured.

  An accumulator 7 for separating the liquid refrigerant is connected to the suction side of the compressor 2, and the compressor 2 sucks and compresses the gas refrigerant from which the liquid refrigerant has been separated by this accumulator 7,・ Discharge high-pressure gas refrigerant. On the other hand, an oil separator 8 for separating the refrigeration oil contained in the high-temperature and high-pressure gas refrigerant and returning it to the suction side of the compressor 2 is connected to the discharge side of the compressor 2. The refrigerant outlet side of the oil separator 8 is connected to the four-way valve 3 through a pipe 9. That is, the gas refrigerant discharged from the compressor 2 flows into the four-way valve 3 through the oil separator 8 and is guided in a predetermined direction by the four-way valve 3. Further, since the gas refrigerant sucked into the compressor 2 is also guided by the four-way valve 3, the refrigerant suction side of the compressor 2 and the four-way valve 3 are connected by a path 10 constituting a suction line. The path 10 is provided with a waste heat recovery unit 11.

  The four-way valve 3 is connected to one end side of the indoor heat exchanger 5, and a liquid receiver 12 for gas-liquid separation of the refrigerant is connected to the other end side of the indoor heat exchanger 5. . Similarly, the outdoor heat exchanger 4 is connected to the four-way valve 3, and the outdoor expansion valve 6 is provided in a path 13 connecting the outdoor heat exchanger 4 and the indoor heat exchanger 5. ing.

  A bypass pipe 21 constituting the bypass circuit 20 branches off from a pipe 9 connecting the oil separator 8 and the four-way valve 3 on the discharge side of the compressor 2. The bypass pipe 21 is connected to a pipe 14 that connects the outdoor heat exchanger 4 and the outdoor expansion valve 6 in the path 13, and the refrigerant from the bypass circuit 20 is connected to the refrigerant in the pipe 14 at the junction 15. It is configured to merge. That is, the bypass circuit 20 connects the pipe 9 on the discharge side of the compressor 2 and the pipe 14 between the outdoor heat exchanger 4 and the outdoor expansion valve 6 by a bypass pipe 21, and supplies one of the refrigerant discharged from the compressor 2. A portion is branched and merged with the refrigerant in the pipe 14.

The operation at the time of cooling and heating in such a refrigerant circuit configuration will be described.
During the cooling operation, the high-temperature and high-pressure gas refrigerant that is compressed and discharged by the compressor 2 is sent to the outdoor heat exchanger 4 through the four-way valve 3, and the outdoor heat exchanger 4 uses the outdoor fan 17. It is condensed by dissipating heat to the blown outside air, and this condensation heat is dissipated into the outdoor air. Here, the high-temperature and high-pressure supersaturated gas refrigerant changes from gas to liquid. The liquefied refrigerant is rapidly reduced in pressure by the indoor expansion valve 16 and is easily evaporated, and is led to the indoor heat exchanger 5. The indoor heat exchanger 5 serves as an evaporator, and the refrigerant removes heat of evaporation from the indoor air and changes from liquid to gas, and cools the indoor air. The vaporized refrigerant passes through the path 10 via the four-way valve 3, passes through the accumulator 7, is sucked and compressed by the compressor 2, and then discharged again.

  On the other hand, during the heating operation, the high-temperature and high-pressure gas refrigerant compressed and discharged by the compressor 2 is sent to the indoor heat exchanger 5 through the four-way valve 3, and the indoor heat exchanger 5 It is condensed by releasing heat to the indoor air blown by 18, and this condensation heat is released into the indoor air and warms the indoor air. Here, the refrigerant changes from gas to liquid. The liquefied refrigerant is rapidly reduced in pressure by the outdoor expansion valve 6 and easily evaporated, and is led to the outdoor heat exchanger 4. This outdoor heat exchanger 4 becomes an evaporator, and the refrigerant takes heat of evaporation from the outdoor air, and a part of the refrigerant changes from liquid to gas. Further, the refrigerant evaporated through the outdoor heat exchanger 4 is completely evaporated by taking heat from the cooling water (hot water) of the engine 1 through the four-way valve 3 in the waste heat recovery unit 11 of the path 10. The vaporized refrigerant passes through the accumulator 7 and is sucked and compressed by the compressor 2 and then discharged again.

  When the outdoor air temperature is low and the heating operation is continued, frost may adhere to the outdoor heat exchanger 4. The adhesion of frost to the outdoor heat exchanger 4 extremely reduces the amount of heat absorbed from the outdoor air, resulting in a decrease in heating efficiency. Therefore, when a certain amount or more of frost adheres to the outdoor heat exchanger 4, a defrost operation is performed in which the outdoor heat exchanger 4 is defrosted and the evaporation performance of the outdoor heat exchanger 4 is restored. That is, the bypass circuit 20 is provided with an electromagnetic valve 22, and during the defrost operation, the electromagnetic valve 22 is opened, and a part of the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 is in the pipe 9. It branches to the bypass circuit 20 and joins at the junction 15 through the bypass pipe 21. As a result, during the heating operation, the high-temperature and high-pressure gas refrigerant joins the liquid refrigerant that has become low-temperature and low-pressure by the outdoor expansion valve 6, and the refrigerant introduced into the outdoor heat exchanger 4 is heated and pressurized. The frost attached to the fins of the heat exchanger 4 is melted and defrosted.

  The bypass circuit 20 is used to prevent excessive refrigerant supply to the outdoor heat exchanger 4 and the indoor heat exchanger 5 that may cause malfunction of the heat pump device, in addition to the above-described defrost operation. Is also used. That is, when the refrigerant supplied to the outdoor heat exchanger 4 or the indoor heat exchanger 5 exceeds a certain amount, the electromagnetic valve 22 is opened or the opening degree is adjusted, and a part of the refrigerant discharged from the compressor 2 Is branched from the bypass circuit 20 and the amount of refrigerant supplied to the outdoor heat exchanger 4 and the indoor heat exchanger 5 is adjusted.

  As described above, in the bypass circuit 20 through which the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 passes, the flow velocity of the refrigerant increases and the above-described airflow noise is generated. Therefore, in order to reduce the airflow noise resulting from this bypass circuit configuration, the bypass circuit 20 is provided with a pressure loss portion 30 for increasing the pressure loss (hereinafter referred to as “pressure loss”) in the bypass pipe 21.

  Thus, by providing the pressure loss part 30 in the bypass circuit 20, the pressure loss in the bypass circuit 20 is increased, and a part of the energy of the high-temperature / high-pressure gas refrigerant is lost (consumed) and passes through the bypass circuit 20. Since the flow rate of the refrigerant can be reduced, the pressure difference between the refrigerant from the bypass circuit 20 and the refrigerant in the pipe 14 at the junction 15 can be reduced, and the air flow noise generated in the bypass circuit 20 can be reduced. Can do.

  Specifically, the pressure loss part 30 includes a mesh filter 31 as shown in FIG. The mesh filter 31 has a main body having an enlarged portion 32a having a pipe diameter substantially the same as or slightly larger than the bypass pipe 21 constituting the bypass circuit 20, and reduced diameter portions 32b and 32b formed at both ends of the enlarged portion 32a. 32, a mesh-shaped screen 33 provided in the enlarged diameter portion 32 a of the main body 32, and a screen holder 34 for holding the screen 33.

  The screen 33 is formed in a bowl shape, and is disposed in the enlarged diameter portion 32 a so that the gas refrigerant flows into the bowl shape and passes through the screen 33. That is, the opening portion of the screen 33 formed in a bowl shape is formed substantially the same as the refrigerant passage area of the enlarged diameter portion 32a, and almost all of the gas refrigerant passing through the enlarged diameter portion 32a passes through the screen 33. It has become. The screen 33 is provided in the main body 32 while being held by a substantially cylindrical screen holder 34. In other words, the opening of the bowl-shaped screen 33 is fixed to the substantially cylindrical screen holder 34 so that the screen 33 is pre-assembled to the screen holder 34, and the assembled screen 33 and screen holder 34 are the main body. It is press-fitted into 32 and fixed by spot welding or the like. Further, the enlarged diameter portion 32a of the main body 32 is formed with one or a plurality of dimples 35 projecting inward on the inner peripheral surface thereof, and the dimple 35 is downstream of the screen holder 34 with respect to the flow of the refrigerant. It is provided so that it may be located in the side. That is, the dimple 35 prevents the screen 33 and the screen holder 34 from being displaced in the enlarged diameter portion 32 a and the screen 33 from coming out of the screen holder 34 due to the flow of high-pressure and high-speed gas refrigerant.

  The mesh filter 31 having such a configuration is interposed in the bypass pipe 21 by inserting and connecting the bypass pipe 21 constituting the bypass circuit 20 in the reduced diameter portions 32b and 32b at both ends of the main body 32. Provided in the bypass circuit 20. Here, stoppers 36 and 36 for restricting insertion of the bypass pipe 21 are formed on the reduced diameter portions 32b and 32b of the main body 32 over substantially the entire circumference of the inner peripheral surface. By providing the mesh filter 31 in this manner, the pressure loss when the high-temperature and high-pressure gas refrigerant passes through the bypass circuit 20 is increased by the mesh filter 31, so that the flow rate of the gas refrigerant is reduced and the junction 15 The pressure difference between the refrigerant from the bypass circuit 20 and the refrigerant in the pipe 14 is alleviated, and the generation of airflow noise in the bypass circuit 20 is reduced. The configuration of the mesh filter 31 and the method of connecting the mesh filter 31 in the bypass circuit 20 are not limited to the present embodiment, and a mesh-shaped screen 33 is provided in the refrigerant passage in the bypass circuit 20 so that the mesh filter is used. Any configuration that can increase the pressure loss in the bypass circuit 20 may be used.

  As described above, the pressure loss portion 30 provided in the bypass circuit 20 is configured by the mesh filter 31, so that the air flow generated in the bypass circuit 20 has a simple configuration and is preferable in terms of space saving and weight reduction. Sound can be reduced. That is, as a method of increasing the pressure loss in the bypass circuit 20, it is conceivable to change the shape of the bypass pipe 21 by making the shape of the bypass pipe 21 spiral or bellows. The manufacturing man-hours and cost of these are increased, and the space occupied by the bypass pipe 21 is increased, which is not preferable from the viewpoint of space saving and weight reduction. By using the mesh filter 31 in this respect, the above-described effects can be obtained. be able to.

  As a specific example of providing the mesh filter 31 in the bypass circuit 20, as shown in FIG. 3, two mesh filters 31 are arranged in series in the bypass pipe 21 constituting the bypass circuit 20. It is preferable to wear. It was verified from actual measurement results that a higher airflow noise reduction effect can be obtained by providing the mesh filter 31 and configuring the pressure loss part 30 in the bypass circuit 20 in this manner. That is, by arranging a plurality of mesh filters 31 in series, high-temperature and high-pressure gas refrigerant passes through the screen 33 at a plurality of locations to increase the pressure loss, and the alternately arranged enlarged diameter portions 32a and reduced diameters. Since the silencing effect due to the expansion ratio can also be obtained by the portion 32b, it is considered that the more silencing effect can be obtained as more mesh filters 31 are arranged in the bypass pipe 21.

  By the way, in the bypass circuit 20 in the heat pump apparatus as described above, there is a configuration having a throttle portion 23 such as a capillary tube in order to adjust or reduce the flow rate of the gas refrigerant passing through the bypass pipe 21. . In this case, the gas refrigerant passing through the throttle portion 23 has a higher flow velocity, which may facilitate the generation of airflow noise in the bypass circuit 20. For this reason, when the bypass circuit 20 has the throttle part 23, it is preferable to provide the pressure loss part 30, ie, the mesh filter 31, as described above on the downstream side of the throttle part 23.

  Thus, by providing the pressure loss part 30 downstream of the throttle part 23 provided in the bypass circuit 20, it is possible to increase the pressure loss with respect to the gas refrigerant whose flow velocity is increased in the throttle part 23. The airflow noise generated in the bypass circuit 20 can be reduced.

The refrigerant circuit figure of the heat pump apparatus which concerns on this invention. The partial cross section figure which shows the mesh filter which forms the pressure loss part. The perspective view which shows the interposition state of a mesh filter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Compressor 3 Four-way valve 4 Outdoor heat exchanger 5 Indoor heat exchanger 6 Outdoor expansion valve 14 Piping 20 High-pressure refrigerant bypass circuit 23 Restriction part 31 Mesh filter 33 Screen

Claims (3)

A compressor that obtains power from the drive source and compresses the refrigerant;
A four-way valve connected to the discharge side of the compressor and switching the flow of refrigerant during cooling and heating;
An outdoor heat exchanger in which refrigerant is supplied from the compressor via the four-way valve during cooling;
An indoor heat exchanger in which refrigerant is supplied from the compressor via the four-way valve during heating;
An outdoor expansion valve disposed between the outdoor heat exchanger and the indoor heat exchanger;
A high-pressure refrigerant bypass circuit that branches a part of refrigerant discharged from the compressor and merges with refrigerant in a pipe between the outdoor heat exchanger and the outdoor expansion valve,
A heat pump device comprising a pressure loss part in the high-pressure refrigerant bypass circuit.   The heat pump device according to claim 1, wherein the pressure loss portion is provided downstream of a throttle portion provided in the high-pressure refrigerant bypass circuit.   The heat pump apparatus according to claim 1 or 2, wherein the pressure loss part is configured by a mesh filter.

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