JP2022147311A - Refrigerant circuit and vehicular heat pump device - Google Patents

Abstract

To provide a refrigerant circuit enabling efficient use of heat by generating a heating medium directly exchanging heat with a refrigerant in an intended temperature zone.SOLUTION: A refrigerant circuit includes: a compressor compressing a refrigerant; and a refrigerant circulation flow passage for condensing, expanding and evaporating the refrigerant discharged from the compressor and then returning the refrigerant to the compressor. The refrigerant circuit also includes: a first refrigerant heating medium heat exchange part for exchanging heat between the refrigerant and a heating medium; a decompression part for decompressing the refrigerant; a second refrigerant heating medium heat exchange part for exchanging heat between the refrigerant and the heating medium; and a third refrigerant heating medium heat exchange part for exchanging heat between the refrigerant and the heating medium. The refrigerant circuit further includes bypass refrigerant piping capable of selectively bypassing any of the first refrigerant heating medium heat exchange part, the second refrigerant heating medium heat exchange part and the third refrigerant heating medium heat exchange part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a refrigerant circuit and a vehicle heat pump device.

Some refrigerant circuits function as heat pumps by compressing, condensing, expanding, and evaporating circulating refrigerant. It is used as a heat source in thermal management of a vehicle equipped with an engine. In particular, refrigerant circuits for vehicle air conditioning use the heat absorption and heat dissipation of refrigerants to perform cooling, heating, dehumidification, defrosting, and anti-fogging functions. machine.

Conventionally, as a refrigerant circuit for vehicle air conditioning, a first refrigerant circuit and a second refrigerant circuit are formed. It is known that the constant pressure valve and the compressor circulate in order, and in the second refrigerant circulation circuit, the refrigerant circulates in the order of the compressor, the condenser, the second expansion valve, and the cooling water side evaporator (Patent Document 1 below. reference).

In this prior art, the condenser in the refrigerant circuit is a high-pressure side heat exchanger that exchanges heat between the high-pressure side refrigerant discharged from the compressor and the heat medium in the high-temperature heat medium circuit. A low-pressure side heat exchanger that exchanges heat between the refrigerant flowing out of the first expansion valve and the air blown into the vehicle interior by the vehicle interior air conditioner. Also, the cooling water side evaporator in the refrigerant circuit is a low-pressure side heat exchanger that exchanges heat between the refrigerant flowing out of the second expansion valve and the heat medium of the cold/heat medium circuit (so-called chiller). Here, the second expansion valve is a switching valve (a so-called chiller valve) for switching between flowing the refrigerant only through the first refrigerant circulation circuit and flowing the refrigerant through the first refrigerant circulation circuit and the second refrigerant circulation circuit.

JP 2020-104841 A

In the conventional refrigerant circuit described above, a high-temperature heat medium is generated by a high-pressure side heat exchanger using a condenser, and a cold heat medium is generated by a low-pressure side heat exchanger using a cooling water-side evaporator. A heat medium in a desired temperature range is obtained by exchanging heat between the hot heat medium and the low temperature heat medium. In such a conventional technique, heat loss occurs due to heat exchange between heat mediums, and heat medium in a desired temperature range cannot be efficiently generated. When considering the refrigerant circuit as a heat source in heat management, it is desirable to generate a heat medium that directly exchanges heat with the refrigerant in various temperature ranges depending on the application. There was a problem that I could not use it.

In addition, since the conventional refrigerant circuit is based on the premise that the refrigerant flows through the air-side evaporator installed in the vehicle interior air conditioner, it is necessary to lay complicated piping for the refrigerant flow path, including the interior of the vehicle. , there is a problem that the maintenance of the refrigerant piping is inevitably complicated.

The present invention has been proposed to address these problems, and enables efficient heat utilization by generating a heat medium that directly exchanges heat from a refrigerant in a desired temperature range. It is an object of the present invention to provide a refrigerant circuit, to provide a refrigerant circuit that facilitates maintenance of refrigerant pipes, and the like.

In order to solve such problems, the present invention has the following configurations.
In a refrigerant circuit comprising a compressor that compresses a refrigerant and a refrigerant circulation passage that condenses, expands, and evaporates the refrigerant discharged from the compressor and returns it to the compressor, the refrigerant and the heat medium are heat-exchanged. 1 refrigerant heat medium heat exchange part, a decompression part for decompressing the refrigerant, a second refrigerant heat medium heat exchange part for heat exchange between the refrigerant and the heat medium, and a third refrigerant heat medium for heat exchange between the refrigerant and the heat medium a bypass refrigerant pipe capable of selectively bypassing any one of the first refrigerant heat medium heat exchange unit, the second refrigerant heat medium heat exchange unit, and the third refrigerant heat medium heat exchange unit; Refrigerant circuit characterized by having provided.

According to the refrigerant circuit of the present invention having such features, one of the first refrigerant heat medium heat exchange section, the second refrigerant heat medium heat exchange section, and the third refrigerant heat medium heat exchange section is selected by the bypass refrigerant pipe. By constructing the refrigerant circuit with the heat exchanging portion, it is possible to generate a heat medium that directly exchanges heat from the refrigerant in various temperature ranges, thereby obtaining a refrigerant circuit capable of efficient heat utilization.

Further, by connecting the heat medium circuit to the first refrigerant heat medium heat exchange section, the second refrigerant heat medium heat exchange section, and the third refrigerant heat medium heat exchange section, the refrigerant circuit itself can be compactly unitized. can be done. Accordingly, it is possible to provide a refrigerant circuit in which maintenance of refrigerant pipes is easy.

1 is an explanatory diagram showing a refrigerant circuit according to an embodiment of the invention; FIG. Explanatory drawing which showed the operation example of the refrigerant circuit which does not flow a refrigerant|coolant to bypass refrigerant|coolant piping. Explanatory drawing which showed the operation example of the refrigerant circuit which makes a refrigerant|coolant flow through 1st bypass piping. Explanatory drawing which showed the operation example of the refrigerant circuit which makes a refrigerant|coolant flow through 2nd bypass piping. Explanatory drawing which showed the operation example of the refrigerant|coolant circuit which makes a refrigerant|coolant flow through 1st bypass piping and 2nd bypass piping. Mollier diagrams for each operation example in the refrigerant circuit shown in FIG. 2 ((A) is operation mode A, (B) is operation mode B, (C) is operation mode C, and (D) is operation mode D). 3, 4 and 5 (E) is the operation mode E shown in FIG. 3, (F) is the operation mode F shown in FIG. 4, and (G) is the operation mode shown in FIG. The illustrated operating mode G). BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing a system configuration of a vehicle heat pump device using a refrigerant circuit according to an embodiment of the present invention and a utilization example 1 (warming up and heating); BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing a system configuration of a vehicle heat pump device using a refrigerant circuit according to an embodiment of the present invention and a utilization example 2 (heat storage and heating); 1 is an explanatory diagram showing a system configuration of a vehicle heat pump device using a refrigerant circuit according to an embodiment of the present invention and a utilization example 3 (heating using heat storage); FIG. 1 is an explanatory diagram showing a system configuration of a vehicle heat pump device using a refrigerant circuit according to an embodiment of the present invention and a utilization example 4 (heating using heat storage); FIG.

Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same reference numerals in different figures denote portions having the same function, and duplication of description in each figure will be omitted as appropriate. In this specification, the term “refrigerant” refers to a circulating medium in a refrigerant circuit that undergoes state changes in a heat pump (compression, condensation, expansion, evaporation), and the term “heat medium” refers to heat exchange without such state changes. It is a medium (including water and air) that absorbs and radiates heat by

As shown in FIG. 1, the refrigerant circuit 1 according to the embodiment of the present invention includes a compressor 10 that compresses refrigerant, and a refrigerant circuit that condenses, expands, and evaporates the refrigerant discharged from the compressor 10 and returns it to the compressor 10. and a flow path 2 .

The refrigerant circulation flow path 2 includes a first refrigerant heat medium heat exchange section 11 , a pressure reducing section 14 , a second refrigerant heat medium heat exchange section 12 , and a third refrigerant heat medium heat exchange section 13 . Here, the first refrigerant heat medium heat exchange unit 11, the second refrigerant heat medium heat exchange unit 12, and the third refrigerant heat medium heat exchange unit 13 are arranged in the refrigerant circuit 1 when heat exchange with the heat medium is not performed. functions as a refrigerant channel through which the refrigerant passes, and functions as a condenser or evaporator that constitutes a heat pump when heat is exchanged with a heat medium.

In the illustrated example, the refrigerant circulation flow path 2 includes a refrigerant pipe 20 having one end connected to the outlet of the compressor 10 and the other end connected to the inlet of the first refrigerant heat medium heat exchange section 11, and the first refrigerant heat medium. A refrigerant pipe 21, one end of which is connected to the outlet of the heat exchange unit 11 and the other end of which is connected to the inlet of the second refrigerant heat medium heat exchange unit 12, and one end of which is connected to the outlet of the second refrigerant heat medium heat exchange unit 12. A refrigerant pipe 22 whose other end is connected to the inlet of the third refrigerant heat medium heat exchange unit 13, and whose one end is connected to the outlet of the third refrigerant heat medium heat exchange unit and whose other end is connected to the inlet of the compressor 10. Refrigerant piping 23 is provided.

The pressure reducing unit 14 reduces the pressure of the high-pressure refrigerant compressed by the compressor 10 to a predetermined pressure. A first pressure reducing section 14A is provided in the refrigerant pipe 21 between the It is

The refrigerant circuit 1 has a bypass refrigerant pipe 3 in a refrigerant circulation flow path 2 . The bypass refrigerant pipe 3 is provided so as to selectively bypass any one of the first refrigerant heat medium heat exchange section 11 , the second refrigerant heat medium heat exchange section 12 , and the third refrigerant heat medium heat exchange section 13 . The selection of the bypass refrigerant pipe 3 here includes the case where the bypass refrigerant pipe 3 is not used as a refrigerant flow path. A refrigerant circuit 1 is configured in which the refrigerant flows through the exchange portion 12 and the third refrigerant heat medium heat exchange portion 13 .

When the bypass refrigerant pipe 3 is used as a refrigerant flow path, the first refrigerant heat medium heat exchange unit 11 and the second refrigerant heat medium heat exchange unit 12 bypass the third refrigerant heat medium heat exchange unit 13. the refrigerant circuit 1 through which the refrigerant flows, the refrigerant circuit 1 through which the refrigerant bypasses the first refrigerant heat medium heat exchange unit 11 and flows through the second refrigerant heat medium heat exchange unit 12 and the third refrigerant heat medium heat exchange unit 13, the second Refrigerant circuits 1 are configured in which the refrigerant flows through the first refrigerant heat medium heat exchange unit 11 and the third refrigerant heat medium heat exchange unit 13 while bypassing the refrigerant heat medium heat exchange unit 12 . The bypass refrigerant pipe 3 itself selected here is not provided with a heat exchange portion.

In the illustrated example, the bypass refrigerant pipe 3 includes a first bypass pipe 31 that can bypass the second refrigerant heat medium heat exchange unit 12 and a second bypass pipe 32 that can bypass the third refrigerant heat medium heat exchange unit 13. I have.

The first bypass pipe 31 has a branch portion 31A provided in the refrigerant pipe 21, a junction portion 31B provided in the refrigerant pipe 22, and the branch portion 31A is provided upstream of the first pressure reducing portion 14A. 31B is provided on the upstream side of the second pressure reducing section 14B.

The second bypass pipe 32 has a branch portion 32A provided in the refrigerant pipe 22 and a junction portion 32B provided in the refrigerant pipe 23. The branch portion 32A is provided upstream of the junction portion 31B of the first bypass pipe 31. It is Thereby, the confluence portion 31B of the first bypass pipe 31 is provided between the branch portion 32A of the second bypass pipe 32 and the third refrigerant heat medium heat exchange portion 13 .

In addition, the branching portion 32A of the second bypass pipe 32 is provided upstream from the confluence portion 31B of the second pressure reducing portion 14B and the first bypass pipe 31, and the branching portion 32A of the second bypass pipe 32 and the first bypass pipe 31 A backflow preventing means (for example, a check valve) 15 is provided between the merging portion 31B.

Such a refrigerant circuit 1 can be used, for example, as a heat source for a vehicle heat management system. A heat medium having a predetermined temperature range can be generated from each of the heat medium heat exchange section 12 and the third refrigerant heat medium heat exchange section 13 .

In addition, in the refrigerant circuit 1, the refrigerant circulation flow path 2 including the bypass refrigerant pipe 3 can be housed in the unit U indicated by the dashed line in the drawing. 23 and the bypass refrigerant pipe 3 can be easily maintained. Furthermore, when the refrigerant circulation flow path 2 and the bypass refrigerant pipe 3 are housed in the unit U outside the vehicle, it is possible to construct a vehicle heat management system in which the refrigerant does not enter the vehicle.

An operation example of the refrigerant circuit 1 will be described below. Selection of the bypass refrigerant pipe 3 is performed by opening and closing bypass selection valves 31V and 32V. In the refrigerant circuit 1, the control unit C controls the opening and closing of the bypass selection valves 31V and 32V, the pressure reducing unit 14 (the first pressure reducing unit 14A and the second pressure reducing unit 14B), and the compressor 10. Operation mode can be switched.

FIGS. 2 to 5 show an example of operation in the refrigerant circuit 1, showing the flow of refrigerant by selection of the bypass refrigerant pipe 3. FIG. In FIGS. 2 to 5, thick lines indicate pipes through which the coolant flows, and thick line arrows indicate the direction of flow of the coolant.

The operation example shown in FIG. 2 is an operation example in which both the bypass selection valves 31V and 32V are closed to prevent the refrigerant from flowing through the first bypass pipe 31 and the second bypass pipe 32. In this case, the refrigerant in the refrigerant circuit 1 exits the compressor 10, the first refrigerant heat medium heat exchange section 11, the first pressure reducing section 14A, the second refrigerant heat medium heat exchange section 12, the second pressure reducing section 14B, the third refrigerant heat medium heat exchange section 13 while sequentially passing through the refrigerant circulation flow path 2 and returns to the compressor 10 .

In the operation example shown in FIG. 2, four operation modes (operation modes A to D) shown in the Mollier diagram of FIG. 6 can be executed by the control of the first pressure reducing section 14A and the second pressure reducing section 14B.

Operation mode A shown in FIG. 6A is an example in which the first pressure reducing section 14A is fully opened, and pressure reduction is performed only by the second pressure reducing section 14B. The refrigerant in this operation mode A is compressed by the compressor 10, radiates heat to the heat medium in the first refrigerant heat medium heat exchange section 11 and the second refrigerant heat medium heat exchange section 12, and is decompressed in the second pressure reducing section 14B. , absorbs heat from the heat medium in the third refrigerant heat medium heat exchange section 13 . At this time, the first refrigerant heat medium heat exchange unit 11 and the second refrigerant heat medium heat exchange unit 12 function as condensers, and the third refrigerant heat medium heat exchange unit 13 functions as an evaporator. Here, the heat medium circuit heat-exchanged in the first refrigerant heat medium heat exchange unit 11 and the heat medium circuit heat-exchanged in the second refrigerant heat medium heat exchange unit 12 may be independent circuits. Alternatively, they may be circuits connected to each other.

In this operation mode A, the two heat medium circuits connected to the first refrigerant heat medium heat exchange section 11 and the second refrigerant heat medium heat exchange section 12, respectively, are supplied with a high-temperature refrigerant obtained by directly exchanging heat with a high-pressure refrigerant. can flow, and a low-temperature heat medium obtained by directly exchanging heat with a low-pressure refrigerant can flow in one heat medium circuit connected to the third refrigerant heat medium heat exchange unit 13. .

In the operation mode B shown in FIG. 6B, the pressure is reduced in two stages by the first pressure reducing unit 14A and the second pressure reducing unit 14B, and the first refrigerant heat medium heat exchange unit 11 and the second refrigerant heat medium heat The exchanging part 12 performs heat dissipation in two steps. The refrigerant in this operation mode B is compressed by the compressor 10, performs the first stage of heat dissipation to one heat medium in the first refrigerant heat medium heat exchange section 11, and undergoes the first stage of pressure reduction in the first pressure reducing section 14A. is performed, heat is released to another heat medium in the second stage in the second refrigerant heat medium heat exchange section 12, the pressure is reduced in the second stage in the second pressure reducing section 14B, and the third refrigerant heat medium heat exchange section 13 absorbs heat from another heat medium at At this time, the first refrigerant heat medium heat exchange unit 11 and the second refrigerant heat medium heat exchange unit 12 function as condensers, and the third refrigerant heat medium heat exchange unit 13 functions as an evaporator.

In this operation mode B, one heat medium circuit connected to the first refrigerant heat medium heat exchange unit 11 can flow a high-temperature heat medium obtained by directly exchanging heat with a high-pressure refrigerant. Another heat medium circuit connected to the two-refrigerant heat medium heat exchange section 12 contains a heat medium heated to a relatively lower temperature than the high-temperature heat medium obtained by direct heat exchange with the medium-pressure refrigerant. A low-temperature heat medium obtained by directly exchanging heat with the low-pressure refrigerant can be flowed to another heat medium circuit connected to the third refrigerant heat medium heat exchange unit 13 .

That is, according to this operation mode B, by direct heat exchange with the refrigerant, high-temperature heat medium having different temperature ranges can be generated and flowed through separate heat medium circuits. The adjustment of the temperature zone at this time is adjusted by the degree of pressure reduction of the first pressure reducing section 14A.

In the operation mode C shown in FIG. 6C, the pressure is reduced in two steps by the first pressure reducing unit 14A and the second pressure reducing unit 14B, and the second refrigerant heat medium heat exchange unit 12 and the third refrigerant heat medium heat Exothermic absorption is performed in two stages in the exchanging part 13 . The refrigerant in this operation mode C is compressed by the compressor 10, radiates heat to one heat medium in the first refrigerant heat medium heat exchange section 11, is decompressed in the first stage in the first decompression section 14A, and is decompressed in the second stage. The refrigerant heat medium heat exchange unit 12 absorbs heat from another heat medium in the first stage, the second pressure reduction unit 14B performs the second stage pressure reduction, and the third refrigerant heat medium heat exchange unit 13 absorbs other heat. A second stage endotherm is carried out from the medium. At this time, the first refrigerant heat medium heat exchange section 11 functions as a condenser, and the second refrigerant heat medium heat exchange section 12 and the third refrigerant heat medium heat exchange section 13 function as evaporators.

In this operation mode C, one heat medium circuit connected to the first refrigerant heat medium heat exchange unit 11 can flow a high-temperature heat medium obtained by directly exchanging heat with a high-pressure refrigerant. In the heat medium circuit connected to the second refrigerant heat medium heat exchange unit 12 and the heat medium circuit connected to the third refrigerant heat medium heat exchange unit 13, low temperatures in different temperature zones obtained by direct heat exchange with the refrigerant A heat medium can be flowed respectively.

Operation mode D shown in FIG. 6D is an example in which the second pressure reducing section 14B is fully opened, and pressure reduction is performed only by the first pressure reducing section 14A. The refrigerant in this operation mode D is compressed by the compressor 10, radiates heat to the heat medium in the first refrigerant heat medium heat exchange section 11, is decompressed in the first pressure reducing section 14A, and is depressurized in the second refrigerant heat medium heat exchange section 12. and the third refrigerant heat medium heat exchange unit 13 absorb heat from the heat medium. At this time, the first refrigerant heat medium heat exchange section 11 functions as a condenser, and the second refrigerant heat medium heat exchange section 12 and the third refrigerant heat medium heat exchange section 13 function as evaporators. Here, the heat medium circuit heat-exchanged in the second refrigerant heat medium heat exchange unit 12 and the heat medium circuit heat-exchanged in the third refrigerant heat medium heat exchange unit 13 may be independent circuits. Alternatively, they may be circuits connected to each other.

In this operation mode D, the high-temperature heat medium obtained by directly exchanging heat with the high-pressure refrigerant can flow through the heat medium circuit connected to the first refrigerant heat medium heat exchange unit 11, and the second refrigerant heat A low-temperature heat medium obtained by directly exchanging heat with a low-pressure refrigerant can flow through the two heat medium circuits connected to the medium heat exchange unit 12 and the third refrigerant heat medium heat exchange unit 13, respectively.

In the operation example shown in FIG. 3 , the bypass selection valve 31V is opened and the bypass selection valve 32V is closed to form a refrigerant circulation flow path that bypasses the second refrigerant heat medium heat exchange section 12 . In this case, the refrigerant in the refrigerant circuit 1 exits the compressor 10, the first refrigerant heat medium heat exchange portion 11, the branch portion 31A, the first bypass pipe 31, the junction portion 31B, the second pressure reducing portion 14B, the third refrigerant It returns to the compressor 10 through the heat-medium heat exchange part 13 one by one.

The operation example shown in FIG. 3 can execute operation mode E shown in the Mollier diagram of FIG. Heat is radiated to the heat medium in the first refrigerant heat medium heat exchange section 11, pressure is reduced in the second pressure reducing section 14B, and heat is absorbed from the heat medium in the third refrigerant heat medium heat exchange section 13 functioning as an evaporator.

In the operation example shown in FIG. 4, the bypass selection valve 32V is opened, the bypass selection valve 31V is closed, and a refrigerant circulation flow path bypassing the third refrigerant heat medium heat exchange section 13 is formed. The refrigerant in the refrigerant circuit 1 in this case exits the compressor 10 and passes through the first refrigerant heat medium heat exchange section 11, the first pressure reducing section 14A, the second refrigerant heat medium heat exchange section 12, the branch section 32A, and the second bypass. It returns to the compressor 10 sequentially via the pipe 32 and the junction 32B.

The operation example shown in FIG. 4 can execute operation mode F shown in the Mollier diagram of FIG. Heat is radiated to the heat medium in the first refrigerant heat medium heat exchange section 11, pressure is reduced in the first pressure reducing section 14A, and heat is absorbed from the heat medium in the second refrigerant heat medium heat exchange section 12 functioning as an evaporator.

The heat absorption amount of the third refrigerant heat medium heat exchange section 13 in the operation mode E is controlled by the opening degree of the second pressure reducing section 14B, and the heat absorption amount of the second refrigerant heat medium heat exchange section 12 in the operation mode F is It is controlled by the degree of opening of the first pressure reducing section 14A.

In the operation example shown in FIG. 5, both the bypass selection valves 31V and 32V are opened to form two refrigerant circulation flow paths. In this case, the refrigerant in the refrigerant circuit 1 exits the compressor 10 in the refrigerant circulation flow path of the first system, and flows through the first refrigerant heat medium heat exchange portion 11, the branch portion 31A, the first bypass pipe 31, and the confluence portion 31B. , the second pressure reducing unit 14B, and the third refrigerant heat medium heat exchange unit 13, and then return to the compressor 10. In the refrigerant circulation flow path of the second system, the first refrigerant heat medium heat It returns to the compressor 10 via the exchanging part 11, the first pressure reducing part 14A, the second refrigerant heat medium heat exchanging part 12, the branching part 32A, the second bypass pipe 32, and the joining part 32B in order.

In the refrigerant circuit 1, the branch portion 31A of the first bypass pipe 31 is divided into the first refrigerant heat medium heat exchange portion 11 and the second refrigerant heat medium heat exchange portion so that the two refrigerant circulation flow paths described above are formed. 12 and on the upstream side of the first pressure reducing section 14A, and a confluence section 31B of the first bypass pipe 31 is provided between the second refrigerant heat medium heat exchange section 12 and the third refrigerant heat medium heat exchange section 13. It is provided on the downstream side of the branch portion 32A of the second bypass pipe 32 and on the upstream side of the second pressure reducing portion 14B. A backflow preventing means 15 is provided in the refrigerant pipe between the branch portion 32A of the second bypass pipe 32 and the junction portion 31B of the first bypass pipe 31 .

The operation example shown in FIG. 5 can execute an operation mode G shown in the Mollier diagram of FIG. A cycle is formed, and two second refrigerant heat medium heat exchange sections 12 and a third refrigerant heat medium heat exchange section 13 for heat absorption are connected in parallel to one first refrigerant heat medium heat exchange section 11 for heat dissipation. It is

According to this, the required amount of heat absorption can be obtained from the heat medium circuit via the second refrigerant heat medium heat exchange section 12 and the third refrigerant heat medium heat exchange section 13, respectively. At this time, the heat medium circuit that exchanges heat with the second refrigerant heat medium heat exchange section 12 and the heat medium circuit that exchanges heat with the third refrigerant heat medium heat exchange section 13 may be independent circuits or may be connected to each other. circuit may be used.

In this operation mode G, the heat absorption amount of the second refrigerant heat medium heat exchange section 12 can be controlled by the opening degree of the first pressure reducing section 14A, and the heat absorption amount of the third refrigerant heat medium heat exchange section 13 is the second Since it can be controlled by the opening degree of the decompression part 14B, independent control is possible. As a result, in this operation mode G, the heat medium circuit connected to the second refrigerant heat medium heat exchange unit 12 and the heat medium circuit connected to the third refrigerant heat medium heat exchange unit 13 have different temperature zones. can be generated.

Here, the operation mode D in which the second refrigerant heat medium heat exchange section 12 and the third refrigerant heat medium heat exchange section 13 functioning as heat absorbers are connected in series and the operation mode G in which they are connected in parallel will be compared. For example, in an operating condition in which the amount of heat dissipation required for the first refrigerant heat medium heat exchange unit 11 is large and the flow rate of the refrigerant circuit 1 is large, the two heat exchange units on the heat absorption side (second refrigerant heat medium heat exchange unit 12 and the third refrigerant heat medium heat exchange unit 13) are connected in series, the pressure loss in the two heat exchange units increases, but the operation mode in which the two heat exchange units on the heat absorption side are connected in parallel Since G can disperse the flow rate of the refrigerant flowing into each heat exchange section, the pressure loss can be kept low in the two heat exchange sections on the heat absorption side. Therefore, when the refrigerant flow rate of the refrigerant circuit 1 is increased by controlling the compressor 10, by selecting the operation mode G, the refrigerant circuit 1 can be operated with reduced pressure loss.

8 to 11 show system configurations and application examples of a vehicle heat pump device using the refrigerant circuit 1 described above. Again, the thick lines in the refrigerant circuit 1 indicate pipes through which the refrigerant flows, and the thick arrows indicate the direction of flow of the refrigerant. Double lines in the heat medium circuit indicate piping through which the heat medium flows, and double line arrows indicate the direction of flow of the heat medium.

The illustrated system configuration of the vehicle heat pump device uses the refrigerant circuit 1 housed in the unit U as a heat source, and includes the indoor heat exchanger 41 of the indoor air conditioner 40 and the electrical equipment installed in the electrical equipment storage section 50 ( It performs heat management for the battery 51, power control unit 52, inverter 53, motor 54), and an outdoor heat exchanger 60 installed in an engine room or the like.

In the illustrated system, the heat medium circuit 4 is connected to the first refrigerant heat medium heat exchange section 11 in the refrigerant circuit 1, the heat medium circuit 5 is connected to the second refrigerant heat medium heat exchange section 12, and the third refrigerant heat medium A heat medium circuit 6 is connected to the heat exchange portion 13 . In terms of system configuration, a heat medium circuit is provided in which the heat medium heat-exchanged in at least one of the first refrigerant heat medium heat exchange section 11, the second refrigerant heat medium heat exchange section 12, and the third refrigerant heat exchange section 13 circulates. Also, a plurality of heat medium circuits are provided in which the heat medium heat-exchanged in each of the first refrigerant heat medium heat exchange section 11, the second refrigerant heat medium heat exchange section 12, and the third refrigerant heat exchange section 13 circulates.

The heat medium circuit 4 is a circulation flow path through which the heat medium is circulated via the first refrigerant heat medium heat exchange section 11 and the indoor heat exchanger 41 by the circulation pump 4A. The heat medium circuit 5 is provided in the second refrigerant heat medium heat exchange section 12 and each electrical device (battery 51, power control unit 52, inverter 53, motor 54) of the electrical device housing portion 50 by the circulation pump 5A. It is a circulation flow path for circulating the heat medium through the part. In addition, the heat medium circuit 5 is provided with a three-way valve 5B, so that it is possible to switch between a circulation flow path that passes through the heat exchange part of the battery 51 alone and a circulation flow path that sequentially passes through the heat exchange parts of all the electrical equipment. ing. The heat medium circuit 6 is a circulation flow path through which the heat medium is circulated via the third refrigerant heat medium heat exchange section 13 and the outdoor heat exchanger 60 by the circulation pump 6A.

In the application example 1 shown in FIG. 8, such a vehicle heat pump device operates the refrigerant circuit 1 in the above-described operation mode B on the assumption that the vehicle is started in a low-temperature outside air environment (eg, −5° C.). Thus, the warm-up of the battery 51 by the heat medium circuit 5 and the room heating by the heat medium circuit 4 are simultaneously performed.

At this time, the refrigerant circuit 1 causes the first refrigerant heat medium heat exchange unit 11 to function as a high-pressure condenser by reducing the pressure in the first decompression unit 14A and the second decompression unit 14B in stages, and heats the second refrigerant. The medium heat exchange section 12 is made to function as a medium-pressure condenser, and the temperature range of the heat medium circulating in the heat medium circuit 4 and the temperature range of the heat medium circulating in the heat medium circuit 5 are set to different temperature ranges. In this application example 1, when the vehicle is started in a low-temperature outside air environment, the heat medium circuit 4 can heat the room at a heating outlet temperature of about 60°C. The battery 51 can be warmed up at a temperature of 10°C or less.

Next, in a utilization example 2 shown in FIG. 9, assuming that the vehicle is running after starting, the refrigerant circuit 1 is operated in the operation mode E described above, and heat is stored in the heat medium in the heat medium circuit 5 and the heat is stored in the heat medium circuit 4. At the same time, the room is heated by

At this time, in the refrigerant circuit 1, the second refrigerant heat medium heat exchange section 12 is bypassed by the first bypass pipe 31, the first refrigerant heat medium heat exchange section 11 functions as a condenser, and the third refrigerant heat medium heat exchange is performed. Part 13 functions as an evaporator. The second refrigerant heat medium heat exchange section 12 does not function as a heat exchange section, and serves as a simple heat medium flow path in the heat medium circuit 5 .

In this application example 2, the heat medium circuit 5 is formed with a circulation flow path that sequentially passes through all the electrical equipment by switching the three-way valve 5B. The heat generated by 54 is stored in the heat medium of the heat medium circuit 5, and the heat medium of the temperature required for heating (for example, the heating blowing temperature of 50 ° C.) is supplied by the heat medium circuit 4 as in the first application example. The air is sent to the indoor heat exchanger 41 to heat the room.

Next, in utilization example 3 shown in FIG. 10, switching to heat storage utilization is performed when a predetermined amount of stored heat is accumulated while the vehicle is running. At this time, the refrigerant circuit 1 is operated in the operation mode F described above, and the heat stored in the heat medium of the heat medium circuit 5 is absorbed by the second refrigerant heat medium heat exchange section 12 functioning as an evaporator, and condensed. Heat is radiated to the heat medium circuit 4 during room heating in the first refrigerant heat medium heat exchange section 11 functioning as a vessel.

In this utilization example 3, the third refrigerant heat medium heat exchange unit 13 connected to the outdoor heat exchanger 60 is detoured by the second bypass pipe 32 and separated from the refrigerant circuit 1 . As a result, wasteful heat radiation through the third refrigerant heat medium heat exchange portion 13 is suppressed, and the heat stored in the heat medium circuit 5 can be effectively used to heat the room.

Utilization example 4 shown in FIG. 11 assumes a situation where the heat storage amount decreases and the temperature of the battery 51 approaches the lower limit when the heat storage utilization of utilization example 3 is continued, and heat storage utilization and outside air heat absorption are performed together. ing. At this time, the refrigerant circuit 1 is operated in the operation mode G described above, and the second refrigerant heat medium heat exchange section 12 and the third refrigerant heat medium heat exchange section 13 are connected in parallel to the first refrigerant heat medium heat exchange section 11. Of these, the second refrigerant heat medium heat exchange section 12 absorbs heat stored in the heat medium circuit 5 , and the third refrigerant heat medium heat exchange section 13 absorbs outside air heat recovered by the outdoor heat exchanger 60 .

This utilization example 4 can be executed by switching when the heat storage amount decreases in utilization example 3 as described above, but it can also be applied when switching from utilization example 2 to utilization example 3. That is, when a certain amount of stored heat accumulates between the heat storage and heating in Application Example 2, the application is switched to Application Example 4, and the stored heat is used while absorbing heat from the outside air. Then, at the stage when the stored heat is sufficiently accumulated, the heat storage utilization of utilization example 3 is performed. After that, when the amount of stored heat decreases, the system is switched again to Utilization Example 4, and both the external air heat absorption and the stored heat utilization are performed.

According to the refrigerant circuit 1 and the vehicle heat pump device using the refrigerant circuit 1 according to the embodiment of the present invention described above, the first refrigerant heat medium heat exchange portion 11, the second refrigerant heat medium heat exchange portion 12, and the third refrigerant heat medium heat exchange portion Refrigerant circuits 1 with different operation modes can be configured depending on the heat exchange section selected by the bypass refrigerant pipe 3 among the heat exchange sections 13 . As a result, a heat medium that directly exchanges heat from the refrigerant can be generated in various temperature ranges, and the refrigerant circuit 1 can provide a heat source capable of efficient heat utilization.

More specifically, the refrigerant circuit 1 according to the embodiment of the present invention includes a first bypass pipe 31 and a second bypass pipe (two bypass refrigerant pipes) as the bypass refrigerant pipes 3 . As a result, when heat is exchanged in all of the first refrigerant heat medium heat exchange unit 11, the second refrigerant heat medium heat exchange unit 12, and the third refrigerant heat medium heat exchange unit 13, the amount of heat released or absorbed becomes too large, and the heat is When the medium is excessively heated or cooled, bypassing part of the heat exchange section keeps the amount of heat released and absorbed in the appropriate range, and efficiently prevents the medium from being excessively heated or cooled. You can drive safely.

In addition, by providing two bypass refrigerant pipes, the connection relationship among the first refrigerant heat medium heat exchange section 11, the second refrigerant heat medium heat exchange section 12, and the third refrigerant heat medium heat exchange section 13 of the refrigerant circuit 1 can be connected in series. You can switch between connection and parallel connection. As a result, when connected in series, the heat medium in a plurality of temperature zones is generated by controlling the opening degrees of the two decompression units 14 (the first decompression unit 14A and the second decompression unit 14B), and when connected in parallel, the heat transfer medium is in a parallel relationship. It is possible to generate heat medium in the same temperature zone or different temperature zones in the heat exchange part, and various variations can be provided to the refrigerant flow path. This allows the refrigerant circuit to be operated in operating modes suitable for different situations.

In addition, the refrigerant circuit 1 connects the heat medium circuit to each of the first refrigerant heat medium heat exchange unit 11, the second refrigerant heat medium heat exchange unit 12, and the third refrigerant heat medium heat exchange unit 13, so that the refrigerant It can be used as a heat source for a heat management system in a state where the flow path is restricted within the unit U. As a result, the refrigerant circuit 1 can be compactly unitized, and the refrigerant pipes within the unit U can be easily maintained.

Although the embodiments of the present invention have been described in detail above, the specific configuration is not limited to these embodiments, and the present invention may be modified without departing from the gist of the present invention. Included in the invention. In addition, each of the above-described embodiments can be combined by utilizing each other's techniques unless there is a particular contradiction or problem in the purpose, configuration, or the like.

1: refrigerant circuit, 2: refrigerant circulation channel, 3: bypass refrigerant pipe,
4, 5, 6: heat medium circuit, 4A, 5A, 6A: circulation pump, 5B: three-way valve,
10: compressor, 11: first refrigerant heat medium heat exchange unit,
12: second refrigerant heat medium heat exchange unit, 13: third refrigerant heat medium heat exchange unit,
14: decompression section, 14A: first decompression section, 14B: second decompression section,
15: backflow prevention means, 20 to 23: refrigerant pipes,
31: first bypass pipe, 32: second bypass pipe,
31A, 32A: branching portion, 31B, 32B: merging portion,
31V, 32V: Bypass selection valve,
40: indoor air conditioner, 41: indoor heat exchanger,
50: electrical equipment housing, 51: battery,
52: power control unit, 53: inverter, 54: motor,
60: outdoor heat exchanger,
U: unit, C: control unit

Claims (9)

A refrigerant circuit comprising a compressor that compresses a refrigerant and a refrigerant circulation passage that condenses, expands, and evaporates the refrigerant discharged from the compressor and returns the refrigerant to the compressor,
a first refrigerant heat medium heat exchange unit that exchanges heat between the refrigerant and the heat medium;
a decompression unit that decompresses the refrigerant;
a second refrigerant heat medium heat exchange unit that exchanges heat between the refrigerant and the heat medium;
A third refrigerant heat medium heat exchange unit that exchanges heat between the refrigerant and the heat medium,
A bypass refrigerant pipe capable of selectively bypassing any one of the first refrigerant heat medium heat exchange section, the second refrigerant heat medium heat exchange section, and the third refrigerant heat medium heat exchange section is provided. refrigerant circuit. The bypass refrigerant pipe is
a first bypass pipe capable of bypassing the second refrigerant heat medium heat exchange section provided downstream of the first refrigerant heat medium heat exchange section;
2. The refrigerant circuit according to claim 1, further comprising a second bypass pipe capable of bypassing a third refrigerant heat medium heat exchange section provided downstream of the second refrigerant heat medium heat exchange section. 3. The refrigerant circuit according to claim 2, wherein the confluence portion of the first bypass pipe is provided between the branch portion of the second bypass pipe and the third refrigerant heat medium heat exchange portion. The decompression unit is
a first pressure reducing section provided between the first refrigerant heat medium heat exchange section and the second refrigerant heat medium heat exchange section;
a second pressure reducing section provided between the second refrigerant heat medium heat exchange section and the third refrigerant heat medium heat exchange section,
4. The branching portion of the first bypass pipe is provided upstream of the first pressure reducing portion, and the confluence portion of the first bypass pipe is provided upstream of the second pressure reducing portion. refrigerant circuit. 5. The refrigerant circuit according to claim 4, wherein the branching portion of the second bypass pipe is provided upstream from a confluence portion of the second pressure reducing portion and the first bypass pipe. 6. The refrigerant circuit according to claim 5, wherein backflow prevention means is provided between the branch portion of the second bypass pipe and the confluence portion of the first bypass pipe. A heat medium circuit is provided in which a heat medium heat-exchanged in at least one of the first refrigerant heat medium heat exchange section, the second refrigerant heat medium heat exchange section, and the third refrigerant heat exchange section circulates. The refrigerant circuit according to any one of claims 1 to 6. It is characterized by comprising a plurality of heat medium circuits in which the heat medium heat-exchanged in each of the first refrigerant heat medium heat exchange section, the second refrigerant heat medium heat exchange section, and the third refrigerant heat exchange section circulates. The refrigerant circuit according to any one of claims 1-7. A vehicle heat pump device comprising the refrigerant circuit according to any one of claims 1 to 8.

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