Thermal management system

Abstract

The present application provides a kind of heat management system, which can stabilize the operation of hot gas heating and reduce the number of components.A kind of heat management system (1), comprising refrigerant circuit (10), it has compressor (11), high temperature side heat exchanger (12), the first low temperature side heat exchanger (14) of cooling heat medium, the second low temperature side heat exchanger (16) being arranged in parallel with the first low temperature side heat exchanger (14) and cooling heat medium, and the decompression device (13a) being arranged on the upstream side path of the first low temperature side heat exchanger (14), wherein the refrigerant circuit (10) includes the refrigerant flow path (10b) as bypass path, it bypasses high temperature side heat exchanger (12), converges to the downstream side of bifurcation (a2) of refrigerant flow path (10j) and refrigerant flow path (10h) and the upstream side path of decompression device (13a), wherein the refrigerant flow path (10j) is the path of refrigerant flow to the first low temperature side heat exchanger (14), and the refrigerant flow path (10h) is the path of refrigerant flow to the second low temperature side heat exchanger (16).

Description

Technical Field

[0001] This invention relates to a thermal management system. Background Technology

[0002] Techniques for improving heating performance in air conditioning systems are known. For example, Patent Document 1 discloses a refrigerant circuit that improves heating performance by allowing the high-temperature gas discharged from the compressor to bypass an external heat exchanger.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2023 / 037897 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] The purpose of this invention is to provide a thermal management system that enables stable operation of hot gas heating and reduces the number of components.

[0008] Technical means for solving technical problems

[0009] According to one aspect of the present invention, a thermal management system includes a refrigerant circuit having a compressor, a condenser for heating a heat medium, a first evaporator for cooling the heat medium, a second evaporator configured in parallel with the first evaporator and for cooling the heat medium, and a pressure reducing device disposed upstream of the first evaporator. The refrigerant circuit includes a bypass path that bypasses the condenser and converges to a path downstream of the bifurcation between the first and second evaporators and located upstream of the pressure reducing device.

[0010] Invention Effects

[0011] According to the present invention, a thermal management system is provided that can stabilize the operation of hot gas heating and reduce the number of components. Attached Figure Description

[0012] Figure 1 This is a circuit diagram illustrating an example of the structure of the refrigerant circuits included in a thermal management system. Detailed Implementation

[0013] [System Architecture]

[0014] <System Overview>

[0015] Figure 1This is an explanatory diagram showing a general outline of the structure of the thermal management system 1 according to this embodiment. The thermal management system 1 is mounted on a vehicle. The vehicle is preferably a vehicle equipped with a driving battery. The vehicle may be, for example, a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or a fuel cell electric vehicle (FCEV).

[0016] The thermal management system 1 includes a refrigerant circuit 10 configured to circulate refrigerant. The refrigerant may be, for example, hydrofluoroolefins, but is not limited thereto. Furthermore, the thermal management system 1 also includes a heat medium circuit (not shown) for circulating a heat medium, such as a coolant, and a control device (not shown) for controlling the operation of the refrigerant circuit 10 and the heat medium circuit.

[0017] <Refrigerant Circuit>

[0018] The refrigerant circuit 10 is configured to circulate the refrigerant and function as a heat pump that repeatedly compresses, condenses, expands, and evaporates.

[0019] The refrigerant circuit 10 includes a compressor 11, a high-temperature side heat exchanger 12 as a condenser, pressure reducing devices 13a and 13b, a first low-temperature side heat exchanger 14 as a first evaporator, and a second low-temperature side heat exchanger 16 as a second evaporator.

[0020] Compressor 11 compresses the gaseous refrigerant to a high temperature and pressure before discharging it.

[0021] The high-temperature side heat exchanger 12 includes a refrigerant passage 12a and a heat medium passage 12b. The refrigerant passage 12a is through which refrigerant circulating in the refrigerant circuit 10 passes, and the heat medium passage 12b is through which heat medium, for example, is pumped out by a circulating pump P20 located in the heat medium circuit and passes through a heater core in the heat medium circuit. The high-temperature side heat exchanger 12 condenses and dissipates heat from the gaseous refrigerant compressed by the compressor 11, thereby heating the heat medium passing through the heater core. This enables heating of the vehicle interior.

[0022] Pressure reducing devices 13a and 13b are, for example, expansion valves that expand the liquid refrigerant to a low pressure.

[0023] The first low-temperature side heat exchanger 14 includes a refrigerant passage 14a through which refrigerant circulating in the refrigerant circuit 10 passes; and a heat medium passage 14b through which heat medium, for example, is pumped out by a circulation pump P40 provided in the heat medium circuit and passes through a battery temperature regulating unit for regulating the battery temperature. The first low-temperature side heat exchanger 14 cools the heat medium passing through the battery temperature regulating unit by absorbing heat through the evaporation of a low-temperature, low-pressure liquid refrigerant. This enables battery temperature regulation.

[0024] The second low-temperature heat exchanger 16 is configured in parallel with the first low-temperature heat exchanger 14. The second low-temperature heat exchanger 16 includes a refrigerant passage 16a through which refrigerant circulating in the refrigerant circuit 10 passes; and a heat medium passage 16b through which heat medium, for example, is pressurized by a circulating pump P30 located in the heat medium circuit, and through which heat medium passing through the cooler core passes. The second low-temperature heat exchanger 16 causes the low-temperature, low-pressure liquid refrigerant to evaporate and absorb heat, thereby cooling the heat medium passing through the cooler core. This enables cooling of the vehicle interior.

[0025] The various elements of the refrigerant circuit 10 are connected through refrigerant flow paths 10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h, 10i, and 10j.

[0026] That is, the discharge side of the compressor 11 is connected to the inlet of the refrigerant passage 14a of the first low-temperature heat exchanger 14 via the refrigerant flow path 10a, the branch section a1, the refrigerant flow path 10b, the manifold section b1, and the downstream refrigerant flow path 10c. A two-way valve 17, serving as a flow path opening and closing valve, is provided in the path of the refrigerant flow path 10b. A pressure reducing device 13a is provided in the path of the refrigerant flow path 10c. That is, the pressure reducing device 13a is provided upstream of the first low-temperature heat exchanger 14. The outlet of the refrigerant passage 14a of the first low-temperature heat exchanger 14 is connected to the suction side of the compressor 11 via the refrigerant flow path 10d, the manifold section b2, and the downstream refrigerant flow path 10e. A liquid receiver 15 is provided in the path of the refrigerant flow path 10e.

[0027] Furthermore, the discharge side of compressor 11 is connected to the inlet of refrigerant passage 12a of high-temperature heat exchanger 12 via refrigerant flow path 10a, branch a1, and downstream refrigerant flow path 10f connected thereto. The outlet of refrigerant passage 12a of high-temperature heat exchanger 12 is connected to the inlet of refrigerant passage 16a of second low-temperature heat exchanger 16 via refrigerant flow path 10g, branch a2, and downstream refrigerant flow path 10h connected thereto. A pressure reducing device 13b is provided along the path of refrigerant flow path 10h. That is, pressure reducing device 13b is provided upstream of second low-temperature heat exchanger 16. The outlet of refrigerant passage 16a of second low-temperature heat exchanger 16 is connected to the suction side of compressor 11 via refrigerant flow path 10i, confluence b2, and downstream refrigerant flow path 10e connected thereto.

[0028] Furthermore, the outlet of the refrigerant passage 12a of the high-temperature side heat exchanger 12 is connected to the inlet of the refrigerant passage 14a of the first low-temperature side heat exchanger 14 via the refrigerant flow path 10g, the branch a2, the refrigerant flow path 10j, the confluence section b1, and the downstream refrigerant flow path 10c. A check valve 18 is provided on the path of the refrigerant flow path 10j to prevent refrigerant from flowing to the branch a2 side. That is, the check valve 18 is located downstream of the branch a2 and upstream of the confluence section b1 of the refrigerant flow path 10g.

[0029] As described above, by constructing refrigerant flow paths, refrigerant flow path 10b functions as a bypass path that bypasses the high-temperature side heat exchanger 12 and flows downstream of the bifurcation a2 of refrigerant flow path 10j and refrigerant flow path 10h and is located upstream of the pressure reducing device 13a. Refrigerant flow path 10j supplies refrigerant to the first low-temperature side heat exchanger 14, and refrigerant flow path 10h supplies refrigerant to the second low-temperature side heat exchanger 16.

[0030] [System Actions]

[0031] Next, the specific operation of the refrigerant circuit 10 included in the thermal management system 1 of this embodiment will be explained.

[0032] <Execution of Hot Gas Heating Operation>

[0033] Figure 1 This indicates the state of refrigerant circuit 10 when hot gas heating is performed at extremely low external gas temperatures (e.g., -20°C to -30°C).

[0034] When operating the hot gas heating system, open pressure reducing devices 13a and 13b and open two-way valve 17.

[0035] Therefore, the refrigerant discharged from the compressor 11 flows into refrigerant flow paths 10a and 10f, and passes through the refrigerant passage 12a of the high-temperature side heat exchanger 12. On the other hand, the heat medium in the heat medium circuit passes through the heater core and then through the heat medium passage 12b. Then, the heat medium that has absorbed heat in the high-temperature side heat exchanger 12 flows to the heater core, thereby heating the interior of the vehicle.

[0036] The refrigerant, after passing through the refrigerant passage 12a of the high-temperature side heat exchanger 12, flows into the refrigerant flow paths 10g and 10h. As a result, the refrigerant, which has been reduced to a low temperature and low pressure by the pressure reducing device 13b, passes through the refrigerant passage 16a of the second low-temperature side heat exchanger 16. During hot gas heating operation, the heat medium passing through the heat medium passage 16b of the second low-temperature side heat exchanger 16 does not circulate. Therefore, the refrigerant passing through the refrigerant passage 16a of the second low-temperature side heat exchanger 16 does not dissipate heat and flows into the refrigerant flow paths 10i and 10e, and into the suction side of the compressor 11. Thus, during hot gas heating operation, a circulation path is formed through the refrigerant flow paths 10a, 10f, 10g, 10h, 10i, and 10e, causing the refrigerant discharged from the compressor 11 to circulate through the high-temperature side heat exchanger 12.

[0037] Furthermore, the refrigerant discharged from the compressor 11 flows into refrigerant flow paths 10a, 10b, and 10c. As a result, the refrigerant, which has been reduced to a medium temperature and low pressure by the pressure reducing device 13a, passes through the refrigerant passage 14a of the first low-temperature side heat exchanger 14. During hot gas heating operation, the heat medium passing through the heat medium passage 14b of the first low-temperature side heat exchanger 14 does not circulate. Therefore, the refrigerant passing through the heat medium passage 14b of the first low-temperature side heat exchanger 14 does not dissipate heat and flows into refrigerant flow paths 10d and 10e, and into the suction side of the compressor 11. Thus, during hot gas heating operation, a circulation path is formed through the refrigerant flow paths 10a, 10b, 10c, 10d, and 10e, allowing the refrigerant discharged from the compressor 11 to bypass the high-temperature side heat exchanger 12.

[0038] The refrigerant flowing in the bypass path, compared to the refrigerant passing through the high-temperature side heat exchanger 12, returns to the suction side of the compressor 11 at a higher temperature because it does not actively exchange heat. Therefore, during hot gas heating operation, the temperature of the refrigerant drawn into the compressor 11 increases, thereby raising the temperature of the refrigerant discharged from the compressor 11 and thus improving heating capacity.

[0039] Furthermore, during hot gas heating operation, the high-pressure refrigerant can be circulated by the refrigerant flowing in the bypass path, thus stabilizing the hot gas heating operation. In particular, in this embodiment, since there is no heat exchange with the heat medium in the first low-temperature side heat exchanger 14 and the second low-temperature side heat exchanger 16, the hot gas heating operation can be stabilized more effectively.

[0040] Furthermore, when performing hot gas heating operation, the pressure reducing device 13a, which is used to reduce the pressure of the refrigerant flowing in the first low-temperature side heat exchanger 14, can also be used as a pressure reducing device for the refrigerant flowing in the bypass path, thus reducing the number of components.

[0041] Furthermore, by providing a check valve 18, it is possible to prevent the high-pressure refrigerant that bypasses the high-temperature side heat exchanger 12 from flowing to the bifurcation a2 side instead of the first low-temperature side heat exchanger 14 side. Therefore, it is possible to prevent the refrigerant discharged from the compressor 11 from flowing back in the refrigerant circuit 10 in advance.

[0042] <Execution of Battery Cooling Operation>

[0043] In operations other than hot gas heating, for example, during battery cooling operation, the refrigerant flows to the first low-temperature side heat exchanger 14 instead of the second low-temperature side heat exchanger 16. At this time, pressure reducing device 13a is opened, pressure reducing device 13b is fully closed, and the two-way valve 17 is closed. This forms a circulation path consisting of refrigerant flow paths 10a, 10f, 10g, 10j, 10c, 10d, and 10e. On the other hand, the circulation path consisting of refrigerant flow paths 10a, 10f, 10g, 10h, 10i, and 10e, and the bypass path consisting of refrigerant flow paths 10a, 10b, 10c, 10d, and 10e, are not formed. Thus, the refrigerant discharged from the compressor 11, reduced to low temperature and low pressure by pressure reducing device 13a, passes through the refrigerant passage 14a of the first low-temperature side heat exchanger 14. Meanwhile, the heat medium circulating in the battery temperature regulating section in the heat medium circuit passes through the heat medium passage 14b. Then, the heat medium that has been dissipated in the first low-temperature side heat exchanger 14 flows to the battery temperature regulation unit, thereby cooling the battery.

[0044] <Execution of Refrigeration Operation>

[0045] In operations other than hot gas heating, for example, when performing cabin cooling operation, the refrigerant flows to the second low-temperature side heat exchanger 16 instead of the first low-temperature side heat exchanger 14. At this time, the pressure reducing device 13a is fully closed, the pressure reducing device 13b is opened, and the two-way valve 17 is closed. This forms a circulation path consisting of refrigerant flow paths 10a, 10f, 10g, 10h, 10i, and 10e. On the other hand, the circulation path consisting of refrigerant flow paths 10a, 10f, 10g, 10j, 10c, 10d, and 10e, as well as the bypass path consisting of refrigerant flow paths 10a, 10b, 10c, 10d, and 10e, are not formed. Thus, the refrigerant discharged from the compressor 11, reduced to low temperature and low pressure by the pressure reducing device 13b, passes through the refrigerant passage 16a of the second low-temperature side heat exchanger 16. On the other hand, the heat medium circulating in the cooler core in the heat medium circuit passes through the heat medium passage 16b. Then, the heat medium, after being dissipated in the second low-temperature side heat exchanger 16, flows to the cooler core, thereby cooling the interior of the carriage.

[0046] <Execution of Cooling Operation and Battery Cooling Operation>

[0047] In operations other than hot gas heating, such as when performing cabin cooling and battery cooling operations, the refrigerant flows to the first low-temperature side heat exchanger 14 and the second low-temperature side heat exchanger 16. At this time, pressure reducing device 13a and pressure reducing device 13b are opened, and the two-way valve 17 is closed. This forms a circulation path consisting of refrigerant flow paths 10a, 10f, 10g, 10j, 10c, 10d, and 10e, and another circulation path consisting of refrigerant flow paths 10a, 10f, 10g, 10h, 10i, and 10e. On the other hand, a circulation path is not formed via the bypass path consisting of refrigerant flow paths 10a, 10b, 10c, 10d, and 10e. Thus, the refrigerant discharged from the compressor 11, which is reduced to low temperature and low pressure by pressure reducing device 13a, passes through the refrigerant passage 14a of the first low-temperature side heat exchanger 14. Meanwhile, the heat medium in the heat medium circuit, via the battery temperature regulating unit, passes through the heat medium passage 14b. Then, the heat medium, after being cooled in the first low-temperature side heat exchanger 14, flows to the battery temperature regulating section, thereby cooling the battery. Furthermore, the refrigerant discharged from the compressor 11, which is then reduced to a low temperature and low pressure by the pressure reducing device 13b, passes through the refrigerant passage 16a of the second low-temperature side heat exchanger 16. On the other hand, the heat medium in the heat medium circuit, passing through the cooler core, flows through the heat medium passage 16b. Then, the heat medium, after being cooled in the second low-temperature side heat exchanger 16, flows to the cooler core, thereby cooling the interior of the vehicle.

[0048] As described above, in the refrigerant circuit 10 of this embodiment, there is no need to separately install a pressure reducing device for reducing the pressure of the refrigerant flowing in the bypass path, thus reducing the manufacturing cost of the thermal management system 1. Furthermore, when a pressure reducing device is installed in the bypass path, there is a risk of refrigerant leaking from the high-pressure side to the low-pressure side even when the pressure reducing device is fully closed. However, by installing a two-way valve 17 in the bypass path, the refrigerant can be completely cut off, thus preventing performance degradation except for hot gas operation.

[0049] Furthermore, without the check valve 18, there is a risk that the refrigerant may not flow from the branch a1 to the high-temperature heat exchanger 12, where the flow resistance is higher. However, by providing the check valve 18, the pressure in the circuit can be adjusted to allow the refrigerant to flow from the branch a1 to the high-temperature heat exchanger 12. Additionally, when the two-way valve 17 is open, the high-pressure refrigerant flows to the outlet side of the check valve 18. Therefore, by providing the check valve 18, it is possible to prevent the refrigerant after passing through the high-temperature heat exchanger 12 from flowing to the first low-temperature heat exchanger 14.

[0050] Furthermore, by installing a two-way valve 17, the refrigerant can be completely cut off, thus preventing performance degradation during operation other than hot gas operation.

[0051] In addition, in this embodiment, examples are given of the first low-temperature heat exchanger 14 exchanging heat with the heat medium via the battery temperature regulation unit and the second low-temperature heat exchanger 16 exchanging heat with the heat medium via the cooler core. However, the temperature regulation object of the heat medium exchanging heat between the first low-temperature heat exchanger 14 and the second low-temperature heat exchanger 16 may not be limited to this embodiment.

[0052] [Effects of this implementation method]

[0053] (1) A thermal management system comprising a refrigerant circuit 10, the refrigerant circuit 10 having a compressor 11, a high-temperature side heat exchanger 12 serving as a condenser for heating a heat medium, a first low-temperature side heat exchanger 14 serving as a first evaporator for cooling a heat medium, a second low-temperature side heat exchanger 16 configured in parallel with the first low-temperature side heat exchanger 14 and serving as a second evaporator for cooling a heat medium, and a pressure reducing device 13a configured on an upstream path of the first low-temperature side heat exchanger 14, the refrigerant circuit 10 including a refrigerant flow path 10b that bypasses the high-temperature side heat exchanger 12 and flows downstream of the bifurcation a2 of the refrigerant flow path 10j and the refrigerant flow path 10h and is an upstream path of the pressure reducing device 13a, the refrigerant flow path 10j being a path for refrigerant to flow to the first low-temperature side heat exchanger 14, and the refrigerant flow path 10h being a path for refrigerant to flow to the second low-temperature side heat exchanger 16. Therefore, during hot gas heating operation, the refrigerant flowing in the bypass path allows for the circulation of high-pressure refrigerant, thus stabilizing the hot gas heating operation. Furthermore, when performing hot gas heating operation, the pressure-reducing device for the refrigerant flowing in the bypass path can also be the pressure-reducing device 13a used for reducing the pressure of the refrigerant flowing in the first low-temperature side heat exchanger 14, thereby reducing the number of components.

[0054] (2) A check valve 18 is provided on the downstream side of the bifurcation a2 and on the upstream side of the bypass path of the confluence section b1 to prevent refrigerant from flowing to the bifurcation a2 side. Therefore, it is possible to prevent the high-pressure refrigerant that bypasses the high-temperature side heat exchanger 12 from flowing to the bifurcation a2 side instead of to the first low-temperature side heat exchanger 14 side, and thus it is possible to prevent the refrigerant discharged from the compressor 11 from flowing back in the refrigerant circuit 10 in advance.

[0055] (3) A two-way valve 17, which serves as a flow path opening and closing valve, is provided on the refrigerant flow path 10g. Therefore, by providing the two-way valve 17, the refrigerant can be completely cut off, thus preventing performance degradation except for hot gas operation.

[0056] The preferred embodiments of the present invention have been shown and described above. However, the present invention is not limited to the foregoing embodiments, and various modifications and implementations can be made within the scope of the present invention, which is self-evident.

[0057] Symbol Explanation

[0058] 1: Thermal management system; 10: Refrigerant circuit; 13a, 13b: Pressure reducing devices; 17: Two-way valve; 18: Check valve; a1, a2: bifurcation; b1, b2: Convergence section.

Claims

1. A thermal management system comprising a refrigerant circuit, the refrigerant circuit having a compressor, a condenser for heating a heat medium, a first evaporator for cooling the heat medium, a second evaporator configured in parallel with the first evaporator and for cooling the heat medium, and a pressure reducing device configured on an upstream path of the first evaporator, characterized in that, The refrigerant circuit includes a bypass path that bypasses the condenser and merges into a path downstream of the bifurcation between the refrigerant path to the first evaporator and the refrigerant path to the second evaporator, and located upstream of the pressure reducing device.

2. The thermal management system according to claim 1, characterized in that, A check valve is provided on the path downstream of the bifurcation and upstream of the confluence of the bypass path to prevent refrigerant from flowing to the bifurcation side.

3. The thermal management system according to claim 1, characterized in that, A flow path opening and closing valve is provided on the bypass path.

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