Thermal management system for electric vehicle and vehicle

Abstract

The present invention provides a thermal management system for an electric vehicle and the vehicle. The refrigerant circuit of the thermal management system of the present invention includes a compressor, a first heat exchanger, a dual-fluid heat exchanger, a second heat exchanger, a third heat exchanger, a liquid storage and drying device, an internal heat exchanger, a fourth heat exchanger, a first control valve, a fourth control valve, and a first expansion valve. The first heat exchanger, the dual-fluid heat exchanger, and the fourth heat exchanger are all reversible and can be selected as an evaporator or a condenser. The refrigerant in the fourth heat exchanger can directly exchange heat with the battery pack, and the refrigerant in the high-pressure side heat exchange channel and the low-pressure side heat exchange channel in the internal heat exchanger can exchange heat. The thermal management system of the present invention can improve the heat exchange efficiency between the power battery and realize multiple working modes, which is conducive to the promotion and application of heat pump management systems.

Description

Technical Field

[0001] The present invention relates to the technical field, and in particular to a thermal management system for an electric vehicle. The present invention also relates to a vehicle equipped with the thermal management system for an electric vehicle. Background Art

[0002] Currently, more and more electric vehicles are using heat pump air conditioning systems. Compared with traditional PTC heating methods, heat pump air conditioning systems can significantly reduce power consumption during heating, helping to ensure vehicle mileage. However, existing heat pump air conditioning systems still have shortcomings such as complex structures and limited operating modes. They also have problems such as low heat exchange efficiency between existing heat pump air conditioning systems and power batteries, which limits their widespread application. Summary of the Invention

[0003] In view of this, the present invention aims to provide a thermal management system for electric vehicles, so as to facilitate the promotion and application of heat pump air-conditioning systems.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] A thermal management system for an electric vehicle, wherein a refrigerant circuit of the thermal management system includes a compressor, a first heat exchanger, a two-fluid heat exchanger, a second heat exchanger, a third heat exchanger, a liquid storage drying device, an internal heat exchanger, a fourth heat exchanger, a first control valve, a fourth control valve, and a first expansion valve;

[0006] One end of the first heat exchanger is connected to the outlet of the compressor via a third control valve, and the other end of the first heat exchanger is connected to the inlet of the liquid storage and drying device via the dual-fluid heat exchanger and the second control valve; one end of the second heat exchanger is connected to the outlet of the compressor via a fifth control valve, and the other end of the second heat exchanger is connected to the inlet of the liquid storage and drying device via a sixth control valve;

[0007] The inlet of the high-pressure side heat exchange channel in the internal heat exchanger is connected to the outlet of the liquid storage and drying device, the outlet of the high-pressure side heat exchange channel in the internal heat exchanger is connected to the inlet of the third heat exchanger through a third expansion valve, the outlet of the third heat exchanger is connected to the inlet of the low-pressure side heat exchange channel in the internal heat exchanger through a ninth control valve, and the outlet of the low-pressure side heat exchange channel in the internal heat exchanger is connected to the inlet of the compressor;

[0008] One end of the fourth heat exchanger is connected to the outlet of the compressor via a fourth two-way expansion valve and a second control valve, and the other end of the fourth heat exchanger is divided into two parallel paths, one of which is connected to the outlet of the high-pressure side heat exchange channel of the internal heat exchanger via the second expansion valve, and the other is connected to the inlet of the liquid storage and drying device via an eighth control valve;

[0009] One end of the first control valve is connected in parallel between the fourth two-way expansion valve and the second control valve, and the other end of the first control valve is connected to the inlet of the low-pressure side heat exchange channel of the internal heat exchanger. One end of the fourth control valve is connected in parallel between the third control valve and the first heat exchanger, and the other end of the fourth control valve is connected to the inlet of the low-pressure side heat exchange channel of the internal heat exchanger. The inlet of the first expansion valve is connected to the outlet of the high-pressure side heat exchange channel of the internal heat exchanger, and the outlet of the first expansion valve is connected in parallel between the two-fluid heat exchanger and the second control valve.

[0010] The first heat exchanger, the dual-fluid heat exchanger and the fourth heat exchanger are all reversible and can be selected as evaporators or condensers. The refrigerant in the fourth heat exchanger can directly exchange heat with the battery pack, and the refrigerant in the high-pressure side heat exchange channel and the low-pressure side heat exchange channel in the internal heat exchanger can exchange heat.

[0011] Furthermore, in the refrigerant circuit, the positions of the first heat exchanger and the dual-fluid heat exchanger are adjusted, and one end of the dual-fluid heat exchanger is connected to the outlet of the compressor through the third control valve, and the other end of the dual-fluid heat exchanger is connected to the inlet of the liquid storage and drying device through the first heat exchanger and the second control valve, one end of the fourth control valve is connected in parallel between the third control valve and the dual-fluid heat exchanger, and the outlet of the first expansion valve is connected in parallel between the first heat exchanger and the second control valve.

[0012] Furthermore, the sixth control valve is removed from the refrigerant circuit;

[0013] The second heat exchanger is connected in series to the outlet of the compressor, and the fifth control valve is connected in parallel between the outlet of the second heat exchanger and the liquid storage drying device.

[0014] Furthermore, the first heat exchanger is removed from the refrigerant circuit;

[0015] The coolant channel in the dual-fluid heat exchanger can communicate with the cooling channel in the drive motor and at least one of the low-temperature radiator.

[0016] Furthermore, the thermal management system has a single air conditioning cooling mode;

[0017] When the thermal management system is in the single air-conditioning cooling mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor and is at high pressure. The high-pressure refrigerant passes through the third control valve, the first heat exchanger, the two-fluid heat exchanger, and the second control valve and enters the liquid storage and drying device. The refrigerant transfers enthalpy to the outside air at the first heat exchanger and becomes liquid.

[0018] Then, the refrigerant passes through the high-pressure side heat exchange channel in the internal heat exchanger and transfers the enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel. Then, the refrigerant passes through the third expansion valve, the high-pressure refrigerant experiences an isenthalpic pressure drop, and passes through the saturation curve to become a low-pressure gas-liquid mixed state. Then, the low-pressure refrigerant enters the third heat exchanger, cools the cavity inside the air-conditioning box and obtains enthalpy. Then, the low-pressure refrigerant passes through the fourth control valve into the low-pressure side heat exchange channel in the internal heat exchanger, obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and passes through the saturation curve, causing the refrigerant to become gaseous, and finally the low-pressure refrigerant returns to the compressor.

[0019] Furthermore, the thermal management system has a single-battery cooling mode;

[0020] When the thermal management system is in the single-battery cooling mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor and is at high pressure. The high-pressure refrigerant passes through the third control valve, the first heat exchanger, the two-fluid heat exchanger, and the second control valve into the liquid storage and drying device. The refrigerant transfers enthalpy to the outside air at the first heat exchanger and becomes liquid.

[0021] Then, the refrigerant passes through the high-pressure side heat exchange channel in the internal heat exchanger and transfers enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel. Then, the refrigerant passes through the second expansion valve, and the high-pressure refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve to become a low-pressure gas-liquid mixed state. Then, the low-pressure refrigerant enters the fourth heat exchanger to cool the battery and obtain enthalpy. Then, the refrigerant passes through the fourth two-way expansion valve and the first control valve into the low-pressure side heat exchange channel in the internal heat exchanger, and obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and passes through the saturation curve, causing the refrigerant to become gaseous. Finally, the low-pressure refrigerant returns to the compressor.

[0022] Furthermore, the thermal management system has a dual cooling mode;

[0023] When the thermal management system is in the dual cooling mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor and is at high pressure. The high-pressure refrigerant passes through the third control valve, the first heat exchanger, the dual-fluid heat exchanger, and the second control valve and enters the liquid storage and drying device. The refrigerant transfers enthalpy to the outside air at the first heat exchanger and becomes liquid.

[0024] Next, the refrigerant passes through the high-pressure side heat exchange channel in the internal heat exchanger, transferring enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel. The refrigerant is then divided into two paths: one path passes through the third expansion valve and the third heat exchanger, and the other path passes through the second expansion valve and the fourth heat exchanger. At the third expansion valve and the second expansion valve, the high-pressure refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve to become a low-pressure gas-liquid mixed state. At the third heat exchanger, the refrigerant cools the cavity inside the air-conditioning box and obtains enthalpy. At the fourth heat exchanger, the refrigerant cools the battery and obtains enthalpy.

[0025] Then, the refrigerant passing through the fourth control valve merges with the refrigerant passing through the first control valve, enters the low-pressure side heat exchange channel in the internal heat exchanger, obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and crosses the saturation curve, causing the refrigerant to become gaseous, and finally the low-pressure refrigerant returns to the compressor.

[0026] Furthermore, the thermal management system has a heat pump mode;

[0027] When the thermal management system is in the heat pump mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor and is at high pressure. The high-pressure refrigerant passes through the fifth control valve, the second heat exchanger, and the first control valve and enters the liquid storage and drying device, where it heats the air in the air conditioning box at the second heat exchanger, thereby losing enthalpy.

[0028] Then, the refrigerant enters the high-pressure side heat exchange channel in the internal heat exchanger, transfers the enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel, and then the refrigerant passes through the first expansion valve, the refrigerant experiences an isenthalpic pressure drop and crosses the saturation curve, and becomes a low-pressure gas-liquid mixed state, and then the refrigerant enters the first heat exchanger through the dual-fluid heat exchanger, absorbs heat from the outside air at the first heat exchanger to obtain enthalpy, and then the refrigerant passes through the fourth control valve into the low-pressure side heat exchange channel in the internal heat exchanger, the refrigerant obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and crosses the saturation curve, causing the refrigerant to become gaseous, and finally the low-pressure refrigerant returns to the compressor.

[0029] Furthermore, when the thermal management system is in the heat pump mode, the first heat exchanger and the dual-fluid heat exchanger can adjust their positions so that the dual-fluid heat exchanger is connected to the fourth control valve and the first heat exchanger is connected to the first expansion valve.

[0030] Furthermore, the thermal management system has a heat pump + heat recovery mode;

[0031] When the thermal management system is in the heat pump + heat recovery mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor and is at high pressure. The high-pressure refrigerant passes through the fifth control valve, the second heat exchanger, and the first control valve and enters the liquid storage and drying device, where it heats the air in the air conditioning box at the second heat exchanger, thereby losing enthalpy.

[0032] Next, the refrigerant enters the high-pressure side heat exchange channel in the internal heat exchanger and transfers enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel. The refrigerant then passes through the first expansion valve, undergoes an isenthalpic pressure drop, crosses the saturation curve, and becomes a low-pressure gas-liquid mixed state. The refrigerant then passes through the dual-fluid heat exchanger and enters the first heat exchanger, where it absorbs heat from the outside air through the first heat exchanger to obtain enthalpy, and absorbs heat from the motor at the dual-fluid heat exchanger to obtain enthalpy.

[0033] Then, the refrigerant enters the low-pressure side heat exchange channel in the internal heat exchanger through the fourth control valve, the refrigerant obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and crosses the saturation curve, causing the refrigerant to become gaseous, and finally the low-pressure refrigerant returns to the compressor.

[0034] Furthermore, the thermal management system has a heat pump + battery heating mode;

[0035] When the thermal management system is in the heat pump + battery heating mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor and is at high pressure. The gaseous refrigerant is divided into two paths: one path of high-pressure refrigerant passes through the second control valve, the fourth two-way expansion valve, the fourth heat exchanger, and the third control valve, enters the liquid storage and drying device, and heats the battery through the fourth heat exchanger, thereby losing enthalpy; the other path of high-pressure refrigerant passes through the fifth control valve, the second heat exchanger, and the first control valve, enters the liquid storage and drying device, and heats the air in the air conditioning box at the second heat exchanger, thereby losing enthalpy.

[0036] Next, the refrigerant flowing out of the liquid storage and drying device enters the high-pressure side heat exchange channel in the internal heat exchanger, transfers enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel, and then passes through the first expansion valve, where the refrigerant experiences an isenthalpic pressure drop and crosses the saturation curve, becoming a low-pressure gas-liquid mixed state. Then, the refrigerant passes through the dual-fluid heat exchanger and enters the first heat exchanger, where it absorbs heat from the outside air through the first heat exchanger to obtain enthalpy, and absorbs heat from the motor through the dual-fluid heat exchanger to obtain enthalpy.

[0037] Then, the refrigerant enters the low-pressure side heat exchange channel in the internal heat exchanger through the fourth control valve, the refrigerant obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and crosses the saturation curve, causing the refrigerant to become gaseous, and finally the low-pressure refrigerant returns to the compressor.

[0038] Furthermore, the fifth control valve is a stop valve and the sixth control valve is a one-way valve, or the fifth control valve is a stop valve and the sixth control valve is a two-way expansion valve, or the fifth control valve is a two-way expansion valve and the sixth control valve is a one-way valve.

[0039] Furthermore, the thermal management system has a first dehumidification mode;

[0040] When the thermal management system is in the first dehumidification mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor and is at high pressure. The high-pressure refrigerant passes through the fifth control valve, the second heat exchanger, and the first control valve and enters the liquid storage and drying device, where it heats the air inside the air conditioning unit through the second heat exchanger, thereby losing enthalpy.

[0041] Next, the refrigerant enters the high-pressure side heat exchange channel in the internal heat exchanger, transfers enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel, and then passes through the third expansion valve, where the refrigerant experiences an isenthalpic pressure drop and crosses the saturation curve, becoming a low-pressure gas-liquid mixed state. The refrigerant then enters the third heat exchanger, cools the air inside the air conditioner, dehumidifies the vehicle interior, and gains enthalpy.

[0042] Then, the refrigerant enters the low-pressure side heat exchange channel in the internal heat exchanger through the fourth control valve, the refrigerant obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and crosses the saturation curve, causing the refrigerant to become gaseous, and finally the low-pressure refrigerant returns to the compressor.

[0043] Furthermore, the thermal management system has a second dehumidification mode;

[0044] When the thermal management system is in the second dehumidification mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor and is at high pressure. The high-pressure refrigerant passes through the fifth control valve, the second heat exchanger, and the first control valve and enters the liquid storage and drying device, where it heats the air inside the air conditioning box through the second heat exchanger, thereby losing enthalpy.

[0045] Then, the refrigerant enters the high-pressure side heat exchange channel in the internal heat exchanger, transfers enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel, and the refrigerant is divided into two paths. One path of refrigerant passes through the third expansion valve, experiences an isenthalpic pressure drop, crosses the saturation curve, and becomes a low-pressure gas-liquid mixed state. Then, the refrigerant enters the third heat exchanger, cools the air inside the air-conditioning box, dehumidifies the interior of the vehicle, and obtains enthalpy; the other path of refrigerant passes through the first expansion valve, experiences an isenthalpic pressure drop, crosses the saturation curve, and becomes a low-pressure gas-liquid mixed state. Then, the refrigerant enters the dual-fluid heat exchanger and the first heat exchanger, and obtains enthalpy by absorbing heat from the outside air through the first heat exchanger, or obtains enthalpy by absorbing heat from the motor through the dual-fluid heat exchanger.

[0046] Then, the two refrigerants pass through the fourth control valve and the fourth control valve respectively, and enter the low-pressure side heat exchange channel in the internal heat exchanger. The refrigerant obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and passes through the saturation curve, causing the refrigerant to become gaseous. Finally, the low-pressure refrigerant returns to the compressor.

[0047] Compared with the prior art, the present invention has the following advantages:

[0048] The thermal management system for electric vehicles described in the present invention can form a directly reversible air-conditioning system through the arrangement of a compressor, a first heat exchanger, a dual-fluid heat exchanger, a second heat exchanger, a third heat exchanger, a liquid storage and drying device, an internal heat exchanger, and a fourth heat exchanger, and is controlled and connected by multiple control valves. Its structural composition is relatively simple, and it can achieve direct cooling and heating of the battery, thereby improving the heat exchange efficiency between the battery and the battery. At the same time, on the basis of the heat pump mode, it can also achieve single cooling, dual cooling, and heat pump + heat recovery, heat pump + battery heating and dehumidification and other working modes, which is conducive to the promotion and application of heat pump management systems.

[0049] Another object of the present invention is to provide a vehicle, which is an electric vehicle and is equipped with the thermal management system for an electric vehicle as described above.

[0050] The vehicle described in the present invention has the same beneficial effects as the above-mentioned thermal management system, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0052] Figure 1 Schematic diagram of the structure of the direct reversible air-conditioning circuit according to an embodiment of the present invention;

[0053] Figure 2 A schematic diagram of the dual-fluid heat exchanger and the first heat exchanger after adjusting their positions in the direct reversible air-conditioning circuit according to an embodiment of the present invention;

[0054] Figure 3 A schematic diagram of the second heat exchanger after adjusting the position of the direct reversible air-conditioning circuit according to an embodiment of the present invention;

[0055] Figure 4 This is a schematic diagram of a direct reversible air-conditioning circuit according to an embodiment of the present invention without the first heat exchanger;

[0056] Figure 5 Schematic diagram of a direct reversible air conditioning circuit in single air conditioning cooling mode according to an embodiment of the present invention;

[0057] Figure 6 Schematic diagram of changes in refrigerant pressure and enthalpy in single air conditioning cooling mode according to an embodiment of the present invention;

[0058] Figure 7 Schematic diagram of a direct reversible air conditioning circuit in single-battery cooling mode according to an embodiment of the present invention;

[0059] Figure 8 This is a schematic diagram of changes in refrigerant pressure and enthalpy in a single-battery cooling mode according to an embodiment of the present invention;

[0060] Figure 9 Schematic diagram of a direct reversible air conditioning circuit in dual cooling mode according to an embodiment of the present invention;

[0061] Figure 10 Schematic diagram of changes in refrigerant pressure and enthalpy in the dual cooling mode according to an embodiment of the present invention;

[0062] Figure 11 Schematic diagram of a direct reversible air conditioning circuit in heat pump mode according to an embodiment of the present invention;

[0063] Figure 12 Schematic diagram of changes in refrigerant pressure and enthalpy in the heat pump mode according to an embodiment of the present invention;

[0064] Figure 13 Schematic diagram of a direct reversible air conditioning circuit in heat pump + heat recovery mode according to an embodiment of the present invention;

[0065] Figure 14 Schematic diagram of changes in refrigerant pressure and enthalpy in the heat pump + heat recovery mode according to an embodiment of the present invention;

[0066] Figure 15 Schematic diagram of a direct reversible air conditioning circuit in heat pump + battery heating mode according to an embodiment of the present invention;

[0067] Figure 16 Schematic diagram of changes in refrigerant pressure and enthalpy in the heat pump + battery heating mode according to an embodiment of the present invention;

[0068] Figure 17 Schematic diagram of a direct reversible air-conditioning circuit in a first dehumidification mode according to an embodiment of the present invention;

[0069] Figure 18 Schematic diagram of changes in refrigerant pressure and enthalpy in the first dehumidification mode according to an embodiment of the present invention;

[0070] Figure 19 Schematic diagram of a direct reversible air conditioning circuit in the second dehumidification mode according to an embodiment of the present invention;

[0071] Figure 20 Schematic diagram of changes in refrigerant pressure and enthalpy in the second dehumidification mode according to an embodiment of the present invention;

[0072] Description of reference numerals:

[0073] 1. Compressor; 2. First heat exchanger; 3. Two-fluid heat exchanger; 4. Second heat exchanger; 5. Third heat exchanger; 6. Liquid storage and drying device; 7. Internal heat exchanger; 8. Fourth heat exchanger; 9. First control valve; 10. Second control valve; 11. Third control valve; 12. Fourth control valve; 13. Fifth control valve; 14. First expansion valve; 15. Second expansion valve; 16. Third expansion valve; 17. Fourth two-way expansion valve; 18. Sixth control valve; 19. Seventh control valve; 20. Eighth control valve; 21. Ninth control valve

[0074] 22-29, connecting points. DETAILED DESCRIPTION

[0075] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0076] In the description of the present invention, it should be noted that if terms such as "upper," "lower," "inner," and "outer" appear to indicate orientation or positional relationships, these are based on the orientation or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, if terms such as "first" and "second" appear, they are used solely for descriptive purposes and should not be construed as indicating or implying relative importance.

[0077] Furthermore, in the description of the present invention, unless otherwise explicitly stated, mating components may be connected using conventional connection structures in the art. Furthermore, the terms "installed," "connected," "connected," and "connector" should be interpreted broadly. For example, they may be fixed, removable, or integral; mechanical or electrical; directly or indirectly through an intermediary, or internally connected between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0078] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0079] Example 1

[0080] This embodiment relates to a thermal management system for electric vehicles, Figure 1 As shown in the figure, in terms of overall structure, the refrigerant circuit of the thermal management system includes a compressor 1, a first heat exchanger 2, a dual-fluid heat exchanger 3, a second heat exchanger 4, a third heat exchanger 5, a liquid storage and drying device 6, an internal heat exchanger 7, a fourth heat exchanger 8, a first control valve 9, a fourth control valve 12 and a first expansion valve 14.

[0081] One end of the first heat exchanger 2 is connected to the outlet of the compressor 1 via the third control valve 11, and the other end of the first heat exchanger 2 is connected to the inlet of the liquid storage and drying device 6 via the dual-fluid heat exchanger 3 and the second control valve 19. One end of the second heat exchanger 4 is connected to the outlet of the compressor 1 via the fifth control valve 13, and the other end of the second heat exchanger 4 is connected to the inlet of the liquid storage and drying device 6 via the sixth control valve 18.

[0082] The inlet of the high-pressure heat exchange channel in the internal heat exchanger 7 is connected to the outlet of the liquid storage and drying device 6. The outlet of the high-pressure heat exchange channel in the internal heat exchanger 7 is connected to the inlet of the third heat exchanger 5 via the third expansion valve 16. The outlet of the third heat exchanger 5 is connected to the inlet of the low-pressure heat exchange channel in the internal heat exchanger 7 via the ninth control valve 21. The outlet of the low-pressure heat exchange channel in the internal heat exchanger 7 is connected to the inlet of the compressor 1.

[0083] One end of the fourth heat exchanger 8 is connected to the outlet of the compressor 1 through the fourth two-way expansion valve 17 and the second control valve 10, and the other end of the fourth heat exchanger 8 is divided into two parallel paths, one of which is connected to the outlet of the high-pressure side heat exchange channel of the internal heat exchanger 7 through the second expansion valve 15, and the other is connected to the inlet of the liquid storage drying device 6 through the eighth control valve 20.

[0084] One end of the first control valve 9 is connected in parallel between the fourth two-way expansion valve 17 and the second control valve 10, and the other end of the first control valve 9 is connected to the inlet of the low-pressure heat exchange channel in the internal heat exchanger 7. One end of the fourth control valve 12 is connected in parallel between the third control valve 11 and the first heat exchanger 2, and the other end of the fourth control valve 12 is connected to the inlet of the low-pressure heat exchange channel in the internal heat exchanger 7. The inlet of the first expansion valve 14 is also connected to the outlet of the high-pressure heat exchange channel in the internal heat exchanger 7, and the outlet of the first expansion valve 14 is connected in parallel between the two-fluid heat exchanger 3 and the second control valve 19.

[0085] Still see Figure 1 As shown, in order to more clearly illustrate the connection between the various components in the system, a total of 8 connection points are set in the figure, from connection point 22 to connection point 29. The components that intersect and connect at the connection points are connected to each other to achieve the connection relationship required by the thermal management system of this embodiment. Of course, in actual implementation, the connection points between the actual components may not be as shown. Figure 1 As in the example, they are connected at the same point, but it is undeniable that the connection relationship that can be achieved is still the same as Figure 1 The same in.

[0086] In addition, based on the above overall structure, in the thermal management system of this embodiment, specifically, the above-mentioned first heat exchanger 2, dual-fluid heat exchanger 3 and fourth heat exchanger 8 are all reversible and can be selected as evaporators or condensers depending on the flow direction. At the same time, the refrigerant in the fourth heat exchanger 8 can directly exchange heat with the battery pack, thereby eliminating the need for indirect heat exchange with the coolant. The refrigerant in the high-pressure side heat exchange channel and the low-pressure side heat exchange channel in the internal heat exchanger 7 can exchange heat to achieve the internal heat exchange function of the internal heat exchanger 7.

[0087] It should be noted that, as a dual-fluid heat exchange structure, the dual-fluid heat exchanger 3 of this embodiment has a refrigerant channel and a coolant channel. Refrigerant flows in the refrigerant channel, while coolant flows in the coolant channel. In the dual-fluid heat exchanger 3, the refrigerant in the refrigerant channel and the coolant in the coolant channel can exchange heat, thereby achieving heat exchange.

[0088] The internal heat exchanger 7 of this embodiment has a high-pressure heat exchange channel and a low-pressure heat exchange channel. It is worth noting that the so-called high-pressure side and low-pressure side refer to the refrigerant flowing through the channel being in a high-pressure state or a low-pressure state. Furthermore, the refrigerant in the high-pressure heat exchange channel and the low-pressure heat exchange channel can exchange heat within the internal heat exchanger 7, thereby achieving the heat exchange function of the internal heat exchanger 7.

[0089] During specific implementation, the internal heat exchanger 7 in this embodiment may be, for example, an existing coaxial tube.

[0090] The arrangement of the gas-liquid separation device 6 in this embodiment can be understood to separate the gaseous and liquid refrigerant fluids, thereby helping to improve the heat exchange efficiency of the refrigerant. In specific implementation, the gas-liquid separation device 6 can be a separator product for gas-liquid separation of refrigerants.

[0091] In this embodiment, in a specific implementation, preferably, the first control valve 9, the second control valve 10, the third control valve 11, the fourth control valve 12, and the fifth control valve 13 can be preferably electrically controlled stop valves, and the sixth control valve 18, the seventh control valve 19, the eighth control valve 20, and the ninth control valve 21 can be preferably check valves. Of course, in addition to using stop valves and check valves respectively, the control valves of this embodiment can also use other valve structures that can meet the needs of use.

[0092] In specific implementation, the first expansion valve 14, the second expansion valve 15, the third expansion valve 16 and the fourth bidirectional expansion valve 17 of this embodiment can all be existing expansion valve products. And among them, the first expansion valve 14, the second expansion valve 15 and the third expansion valve 16 can generally adopt existing one-way expansion valves, while for the fourth bidirectional expansion valve 17, still refer to Figure 1 As shown, it can be specifically configured to be in a throttling or full-pass state along the direction from the connecting point 24 to the fourth heat exchanger 8, and can only be in a full-pass state along the direction from the fourth heat exchanger 8 to the connecting point 24.

[0093] In addition, Figure 1 Based on the overall structure of the thermal management system shown, taking into account the distribution of heat absorption during system heating and based on different cost requirements, in specific implementation, some components in the loop can be adjusted to form alternative methods that match the corresponding needs.

[0094] Specifically, for example, considering the heat absorption distribution of the system during heating, as the first alternative, continue as follows Figure 2As shown in FIG, in the refrigerant circuit of this embodiment, the positions of the first heat exchanger 2 and the two-fluid heat exchanger 3 can be adjusted so that one end of the two-fluid heat exchanger 3 is connected to the outlet of the compressor 1 through the third control valve 11, and the other end of the two-fluid heat exchanger 3 is connected to the inlet of the liquid storage and drying device 6 through the first heat exchanger 2 and the second control valve 19. At the same time, one end of the fourth control valve 12 is connected in parallel between the third control valve 11 and the two-fluid heat exchanger 3, and the outlet of the first expansion valve 14 is connected in parallel between the first heat exchanger 2 and the second control valve 19.

[0095] Based on the first alternative method mentioned above, in this embodiment, based on different cost requirements, continue as follows Figure 3 As shown in , as a second alternative, the sixth control valve 18 can also be removed from the refrigerant circuit of this embodiment, and the second heat exchanger 4 can be connected in series at the outlet of the compressor 1, and the fifth control valve 13 can be connected in parallel between the outlet of the second heat exchanger 4 and the liquid storage drying device 6.

[0096] Of course, in addition to the second alternative, in this embodiment, still based on the first alternative, continue as follows Figure 4 As shown in the figure, the first heat exchanger 2 can also be removed from the refrigerant circuit, and in this case, in a specific implementation, the coolant channel in the dual-fluid heat exchanger 3 can be connected to the cooling channel in the drive motor and the low-temperature radiator, or the coolant channel in the dual-fluid heat exchanger 3 can be connected to the cooling channel in the drive motor and one of the low-temperature radiators.

[0097] In this embodiment, based on the above description, Figure 1 Taking the structure of the indirect reversible air-conditioning system shown as an example, in specific implementation, by controlling the above-mentioned control valves, the working mode of the indirect reversible air-conditioning system of this embodiment is specifically described as follows.

[0098] 1. Single air conditioning cooling mode

[0099] Combine Figure 5 As shown in the figure, the thermal management system of this embodiment has a single air-conditioning cooling mode. When the thermal management system is in the single air-conditioning cooling mode, the refrigerant circuit is mainly composed of a compressor 1, a third control valve 11, a first heat exchanger 2, a dual-fluid heat exchanger 3, a seventh control valve 19, a liquid storage and drying device 6, an internal heat exchanger 7, a third expansion valve 16, a third heat exchanger 5, and a ninth control valve 21.

[0100] During specific operation, the gaseous refrigerant is at high pressure after being compressed by the compressor 1. The high-pressure refrigerant enters the liquid storage and drying device 6 through the third control valve 11, the first heat exchanger 2, the dual-fluid heat exchanger 3 and the second control valve 19, and the refrigerant transfers the enthalpy value to the outside air at the first heat exchanger 2 and becomes liquid.

[0101] The refrigerant then passes through the high-pressure heat exchange channel of the internal heat exchanger 7, transferring enthalpy to the low-pressure refrigerant in the low-pressure heat exchange channel. The refrigerant then passes through the third expansion valve 16, where the high-pressure refrigerant experiences an isenthalpic pressure drop and crosses the saturation curve to become a low-pressure gas-liquid mixed state. The low-pressure refrigerant then enters the third heat exchanger 5, cooling the air inside the air conditioner and gaining enthalpy. The low-pressure refrigerant then passes through the fourth control valve 21 and enters the low-pressure heat exchange channel of the internal heat exchanger 7, where it gains enthalpy from the refrigerant in the high-pressure heat exchange channel and crosses the saturation curve, causing the refrigerant to become a gas. Finally, the low-pressure refrigerant returns to the compressor 1.

[0102] Figure 6 The figure shows the changes in pressure and enthalpy experienced by the refrigerant in the single air conditioning cooling mode, wherein the curve X represents the saturated state of the refrigerant fluid.

[0103] Specifically, the refrigerant fluid entering compressor 1 is in a gaseous phase. As it passes through compressor 1, it undergoes compression, as indicated by arrow 100, resulting in a high-pressure refrigerant fluid. The high-pressure refrigerant fluid then enters first heat exchanger 2 and transfers enthalpy to the external air flow, as indicated by arrow 600. The refrigerant exiting first heat exchanger 2 is in a pure liquid state and then enters internal heat exchanger 7, where it loses enthalpy, as indicated by arrow 10a. This enthalpy is then transferred to the low-pressure refrigerant fluid, as indicated by arrow 10b.

[0104] The high-pressure refrigerant then passes through the third expansion valve 16, where it experiences an isenthalpic pressure drop as indicated by arrow 110 and crosses the saturation curve X, causing it to switch to a gas-liquid mixture state at a low pressure. The low-pressure refrigerant then passes through the third heat exchanger 5, where it gains enthalpy as indicated by arrow 150. The low-pressure refrigerant then passes through the internal heat exchanger 7, where it gains enthalpy as indicated by arrow 10b from the high-pressure refrigerant fluid that has passed through the internal heat exchanger 7 and crosses the saturation curve X, causing it to switch to a gaseous state. The low-pressure refrigerant then returns to the compressor 1.

[0105] 2. Single battery cooling mode

[0106] Combine Figure 7 As shown in the figure, the thermal management system of this embodiment has a single-battery cooling mode. When the thermal management system is in the single-battery cooling mode, the refrigerant circuit is mainly composed of a compressor 1, a third refrigerant stop valve 11, a first heat exchanger 2, a dual-fluid heat exchanger 3, a second refrigerant one-way valve 19, a liquid storage and drying device 6, an internal heat exchanger 7, a second expansion valve 15, a fourth heat exchanger 8, a fourth two-way expansion device 17, and a first refrigerant stop valve 9.

[0107] During specific operation, in the refrigerant circuit, the gaseous refrigerant is at high pressure after being compressed by the compressor 1. The high-pressure refrigerant passes through the third control valve 11, the first heat exchanger 2, the dual-fluid heat exchanger 3 and the second control valve 19 and enters the liquid storage and drying device 6. The refrigerant transfers the enthalpy value to the outside air at the first heat exchanger 2 and becomes liquid.

[0108] Next, the refrigerant passes through the high-pressure heat exchange channel in the internal heat exchanger 7 and transfers enthalpy to the low-pressure refrigerant in the low-pressure heat exchange channel. Next, the refrigerant passes through the second expansion valve 15, where the high-pressure refrigerant experiences an isenthalpic pressure drop and crosses the saturation curve to become a low-pressure gas-liquid mixed state. Next, the low-pressure refrigerant enters the fourth heat exchanger 8, where it cools the battery and gains enthalpy. Next, the refrigerant passes through the fourth two-way expansion valve 17 and the first control valve 9 and enters the low-pressure heat exchange channel in the internal heat exchanger 7, where it gains enthalpy from the refrigerant in the high-pressure heat exchange channel and crosses the saturation curve, causing the refrigerant to become gaseous. Finally, the low-pressure refrigerant returns to the compressor 1.

[0109] Figure 8 The changes in pressure and enthalpy experienced by the refrigerant in the single-battery cooling mode are shown, and wherein the curve X represents the saturated state of the refrigerant fluid.

[0110] Specifically, the refrigerant fluid entering compressor 1 is in a gaseous phase. As it passes through compressor 1, it undergoes compression, as indicated by arrow 100, resulting in a high-pressure refrigerant fluid. The high-pressure refrigerant fluid then enters first heat exchanger 2 and transfers enthalpy to the external air flow, as indicated by arrow 600. The refrigerant exiting first heat exchanger 2 is in a pure liquid state and then enters internal heat exchanger 7, where it loses enthalpy, as indicated by arrow 10a. This enthalpy is then transferred to the low-pressure refrigerant fluid, as indicated by arrow 10b.

[0111] The high-pressure refrigerant then passes through the second expansion valve 15, where it experiences an isenthalpic pressure drop, as indicated by arrow 110, and crosses the saturation curve X, causing it to switch to a gas-liquid mixture state at a low pressure. The low-pressure refrigerant then passes through the fourth heat exchanger 8, where it gains enthalpy, as indicated by arrow 150. The low-pressure refrigerant then passes through the internal heat exchanger 7, where it gains enthalpy, as indicated by arrow 10b, from the high-pressure refrigerant fluid that has passed through the internal heat exchanger 7. It then crosses the saturation curve X, causing it to switch to a gaseous state, and the low-pressure refrigerant then returns to the compressor 1.

[0112] 3. Dual cooling mode;

[0113] Combine Figure 9As shown in , the thermal management system of this embodiment has a dual cooling mode. When the thermal management system is in the dual cooling mode, the refrigerant circuit is mainly composed of a compressor 1, a third refrigerant stop valve 11, a first heat exchanger 2, a dual-fluid heat exchanger 3, a second refrigerant one-way valve 19, a liquid storage and drying device 6, an internal heat exchanger 7, a second expansion valve 15, a fourth heat exchanger 8, a fourth two-way expansion device 17, a first refrigerant stop valve 9, a third expansion valve 16, a third heat exchanger 5, and a fourth refrigerant one-way valve 21.

[0114] During specific operation, in the refrigerant circuit, the gaseous refrigerant is at high pressure after being compressed by the compressor 1. The high-pressure refrigerant passes through the third control valve 11, the first heat exchanger 2, the dual-fluid heat exchanger 3 and the second control valve 19 and enters the liquid storage and drying device 6. The refrigerant transfers the enthalpy value to the outside air at the first heat exchanger 2 and becomes liquid.

[0115] The refrigerant then passes through the high-pressure heat exchange channel in the internal heat exchanger 7, transferring enthalpy to the low-pressure refrigerant in the low-pressure heat exchange channel. The refrigerant then splits into two paths: one path passes through the third expansion valve 16 and the third heat exchanger 5, and the other path passes through the second expansion valve 15 and the fourth heat exchanger 8. At the third and second expansion valves 16 and 15, the high-pressure refrigerant experiences an isenthalpic pressure drop and crosses the saturation curve, becoming a low-pressure gas-liquid mixed state. At the third heat exchanger 5, the refrigerant cools the air inside the air conditioner and gains enthalpy. At the fourth heat exchanger 8, the refrigerant cools the battery and gains enthalpy.

[0116] Then, the refrigerant passing through the fourth control valve 21 merges with the refrigerant passing through the first control valve 9, enters the low-pressure side heat exchange channel in the internal heat exchanger 7, obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and crosses the saturation curve, causing the refrigerant to become gaseous, and finally the low-pressure refrigerant returns to the compressor 1.

[0117] Figure 10 The changes in pressure and enthalpy experienced by the refrigerant in the dual refrigeration mode are shown, and wherein the curve X represents the saturated state of the refrigerant fluid.

[0118] Specifically, the refrigerant fluid entering compressor 1 is in a gaseous phase. As it passes through compressor 1, it undergoes compression, as indicated by arrow 100, resulting in a high-pressure refrigerant fluid. The high-pressure refrigerant fluid then enters first heat exchanger 2 and transfers enthalpy to the external air flow, as indicated by arrow 600. The refrigerant exiting first heat exchanger 2 is in a pure liquid state and then enters internal heat exchanger 7, where it loses enthalpy, as indicated by arrow 10a. This enthalpy is then transferred to the low-pressure refrigerant fluid, as indicated by arrow 10b.

[0119] The high-pressure refrigerant then splits into two branches, passing through third expansion valve 16 and second expansion valve 15, respectively. The high-pressure refrigerant fluid experiences an isenthalpic pressure drop, indicated by arrow 120, and crosses saturation curve X, causing it to switch to a gas-liquid mixture state at a low pressure. The low-pressure refrigerant fluid then passes through third heat exchanger 5 and fourth heat exchanger 8, respectively, where it gains enthalpy, as indicated by arrows 160 and 180, respectively, while cooling the internal air flow.

[0120] The low-pressure refrigerant fluid then passes through the internal heat exchanger 7, where it acquires enthalpy as indicated by arrow 10b from the high-pressure refrigerant fluid passing through the internal heat exchanger 7 and crosses the saturation curve X, which causes it to switch to a gaseous state, and then the low-pressure refrigerant fluid returns to the compressor 1.

[0121] 4. Heat pump mode;

[0122] Combine Figure 11 As shown in , the thermal management system of this embodiment has a heat pump mode. When the thermal management system is in the heat pump mode, the refrigerant circuit is mainly composed of a compressor 1, a fifth refrigerant stop valve 13, a second heat exchanger 4, a first refrigerant one-way valve 18, a liquid storage and drying device 6, an internal heat exchanger 7, a first expansion valve 14, a dual-fluid heat exchanger 3, a first heat exchanger 2, and a fourth refrigerant stop valve 12.

[0123] During specific operation, in the refrigerant circuit, the gaseous refrigerant is at high pressure after being compressed by the compressor 1. The high-pressure refrigerant enters the liquid storage and drying device 6 through the fifth control valve 13, the second heat exchanger 4 and the first control valve 18, and heats the air in the air-conditioning box at the second heat exchanger 4 to lose enthalpy.

[0124] Next, the refrigerant enters the high-pressure heat exchange channel of the internal heat exchanger 7, transferring enthalpy to the low-pressure refrigerant in the low-pressure heat exchange channel. The refrigerant then passes through the first expansion valve 14, where it experiences an isenthalpic pressure drop and crosses the saturation curve, becoming a low-pressure gas-liquid mixed state. Next, the refrigerant passes through the dual-fluid heat exchanger 3 and enters the first heat exchanger 2, where it absorbs heat from the outside air and gains enthalpy. The refrigerant then passes through the fourth control valve 12 and enters the low-pressure heat exchange channel of the internal heat exchanger 7, where it gains enthalpy from the refrigerant in the high-pressure heat exchange channel and crosses the saturation curve, causing the refrigerant to become a gas. Finally, the low-pressure refrigerant returns to the compressor 1.

[0125] Figure 12 The changes in pressure and enthalpy experienced by the refrigerant in heat pump mode are shown, and wherein the curve X represents the saturated state of the refrigerant fluid.

[0126] Specifically, the refrigerant fluid entering the compressor 1 is in the gas phase. As the refrigerant fluid passes through the compressor 1, it undergoes compression, as indicated by arrow 100, and is now at high pressure. The high-pressure refrigerant fluid then enters the second heat exchanger 4 and then the internal heat exchanger 7, transferring enthalpy to the heat transfer fluid in the internal heat exchanger 7, as indicated by arrow 200. At this point, the refrigerant fluid loses enthalpy while maintaining a constant pressure, and is now in the liquid phase, at high pressure, as indicated by arrow 4a.

[0127] The refrigerant fluid then passes through first expansion valve 14, experiencing an isenthalpic pressure drop indicated by arrow 500, which results in it becoming a mixture of gas and liquid, and crossing saturation curve X. At this point, the refrigerant fluid is still a mixture of gas and liquid, and its pressure is low. The low-pressure refrigerant then passes through dual-fluid heat exchanger 3 and first heat exchanger 2, where it absorbs heat from the external air flow, gaining enthalpy. At this point, the refrigerant is in a two-phase state, as indicated by arrow 600. It then passes through internal heat exchanger 7, as indicated by arrow 4b, and finally returns to compressor 1.

[0128] 5. Heat pump + heat recovery mode;

[0129] Combine Figure 13 As shown in , the thermal management system of this embodiment has a heat pump + heat recovery mode. When the thermal management system is in the heat pump + heat recovery mode, the refrigerant circuit is mainly composed of a compressor 1, a fifth refrigerant stop valve 13, a second heat exchanger 4, a first refrigerant one-way valve 18, a liquid storage and drying device 6, an internal heat exchanger 7, a first expansion valve 14, a dual-fluid heat exchanger 3, a first heat exchanger 2, and a fourth refrigerant stop valve 12.

[0130] During specific operation, in the refrigerant circuit, the gaseous refrigerant is at high pressure after being compressed by the compressor 1. The high-pressure refrigerant enters the liquid storage and drying device 6 through the fifth control valve 13, the second heat exchanger 4 and the first control valve 18, and heats the air in the air-conditioning box at the second heat exchanger 4 to lose enthalpy.

[0131] Next, the refrigerant enters the high-pressure side heat exchange channel in the internal heat exchanger 7, transfers the enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel, and then passes through the first expansion valve 14. The refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve, and becomes a low-pressure gas-liquid mixed state. Then the refrigerant enters the first heat exchanger 2 through the dual-fluid heat exchanger 3, and obtains enthalpy by absorbing heat from the outside air through the first heat exchanger 2, and obtains enthalpy by absorbing heat from the motor at the dual-fluid heat exchanger 3.

[0132] Then, the refrigerant enters the low-pressure side heat exchange channel in the internal heat exchanger 7 through the fourth control valve 12. The refrigerant obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and passes through the saturation curve, causing the refrigerant to become gaseous. Finally, the low-pressure refrigerant returns to the compressor 1.

[0133] Figure 14 The changes in pressure and enthalpy experienced by the refrigerant in the heat pump + heat recovery mode are shown, and wherein the curve X represents the saturated state of the refrigerant fluid.

[0134] Specifically, the refrigerant fluid entering the compressor 1 is in the gas phase. As the refrigerant fluid passes through the compressor 1, it undergoes compression, as indicated by arrow 100, and is now at high pressure. The high-pressure refrigerant fluid then enters the second heat exchanger 4 and then the internal heat exchanger 7, where it transfers enthalpy to the heat transfer fluid in the internal heat exchanger 7, as indicated by arrow 200. At this point, the refrigerant fluid loses enthalpy while maintaining a constant pressure, and is now in the liquid phase, at high pressure, as indicated by arrow 10a.

[0135] The refrigerant fluid then passes through first expansion valve 14, experiencing an isenthalpic pressure drop indicated by arrow 110, resulting in a mixture of gas and liquid, and crossing saturation curve X. At this point, the refrigerant fluid remains a mixture of gas and liquid at a low pressure. The low-pressure refrigerant then passes through dual-fluid heat exchanger 3 and first heat exchanger 2, where it absorbs heat from the external air flow and from the drive motor, gaining enthalpy. At this point, the refrigerant is in a two-phase state, as indicated by arrow 150. The refrigerant then passes through internal heat exchanger 7, as indicated by arrow 10b, before returning to compressor 1.

[0136] 6. Heat pump + battery heating mode;

[0137] Combine Figure 15 As shown in , the thermal management system of this embodiment has a heat pump + battery heating mode. When the thermal management system is in the heat pump + battery heating mode, the refrigerant circuit is mainly composed of a compressor 1, a fifth refrigerant stop valve 13, a second heat exchanger 4, a first refrigerant one-way valve 18, a second refrigerant stop valve 10, a fourth two-way expansion device 17, a fourth heat exchanger 8, a third refrigerant one-way valve 20, a liquid storage and drying device 6, an internal heat exchanger 7, a first expansion valve 14, a dual-fluid heat exchanger 3, a first heat exchanger 2, and a fourth refrigerant stop valve 12.

[0138] During specific operation, in the refrigerant circuit, the gaseous refrigerant is at high pressure after being compressed by the compressor 1, and is divided into two paths. One path of high-pressure refrigerant passes through the second control valve 10, the fourth two-way expansion valve 17, the fourth heat exchanger 8 and the third control valve 20 to enter the liquid storage and drying device 6, and loses enthalpy by heating the battery through the fourth heat exchanger 8; the other path of high-pressure refrigerant passes through the fifth control valve 13, the second heat exchanger 4 and the first control valve 18 to enter the liquid storage and drying device 6, and loses enthalpy by heating the air in the air-conditioning box at the second heat exchanger 4.

[0139] Then, the refrigerant flowing out of the liquid storage drying device 6 enters the high-pressure side heat exchange channel in the internal heat exchanger 7, and transfers the enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel. Then the refrigerant passes through the first expansion valve 14, and the refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve, and becomes a low-pressure gas-liquid mixed state. Then the refrigerant enters the first heat exchanger 2 through the dual-fluid heat exchanger 3, and absorbs heat from the outside air through the first heat exchanger 2 to obtain enthalpy, and absorbs heat from the motor through the dual-fluid heat exchanger 3 to obtain enthalpy.

[0140] Then, the refrigerant enters the low-pressure side heat exchange channel in the internal heat exchanger 7 through the fourth control valve 12. The refrigerant obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and passes through the saturation curve, causing the refrigerant to become gaseous. Finally, the low-pressure refrigerant returns to the compressor 1.

[0141] Figure 16 The changes in pressure and enthalpy experienced by the refrigerant in the heat pump + battery heating mode are shown, and wherein the curve X represents the refrigerant fluid saturation state.

[0142] Specifically, the refrigerant fluid entering the compressor 1 is in the gas phase. As the refrigerant fluid passes through the compressor 1, it undergoes compression, as indicated by arrow 100, and is now at high pressure. The high-pressure refrigerant fluid then enters the second heat exchanger 4 and the fourth heat exchanger 8 and transfers enthalpy to the heat transfer fluid in the internal heat exchanger 7, as indicated by arrows 200 and 300. At this point, the refrigerant fluid loses enthalpy while maintaining a constant pressure, and is now in the liquid phase, at high pressure, as indicated by arrow 10a.

[0143] The refrigerant fluid then passes through first expansion valve 14, experiencing an isenthalpic pressure drop indicated by arrow 110, which results in it becoming a mixture of gas and liquid, and crossing saturation curve X. At this point, the refrigerant fluid remains a mixture of gas and liquid, and its pressure is low. The low-pressure refrigerant then passes through dual-fluid heat exchanger 3 and first heat exchanger 2, where it absorbs heat from the external air flow and from the drive motor, gaining enthalpy. At this point, the refrigerant is in a two-phase state, as indicated by arrow 150. The refrigerant then passes through internal heat exchanger 7, as indicated by arrow 10b, and finally returns to compressor 1.

[0144] Furthermore, it is worth noting that when the thermal management system of this embodiment can implement the heat pump + battery heating mode, in addition to the aforementioned configuration of the fifth control valve 13 being a stop valve and the sixth control valve 18 being a one-way valve, in specific implementations, the fifth control valve 13 can also be a stop valve and the sixth control valve 18 a two-way expansion valve, or the fifth control valve 13 can be a two-way expansion valve and the sixth control valve 18 can be a one-way valve.

[0145] 7. First dehumidification mode;

[0146] Combine Figure 17 As shown in , the thermal management system of this embodiment has a first dehumidification mode. When the thermal management system is in the first dehumidification mode, the refrigerant circuit is mainly composed of a compressor 1, a fifth refrigerant stop valve 13, a second heat exchanger 4, a first refrigerant one-way valve 18, a liquid storage drying device 6, an internal heat exchanger 7, a third expansion valve 16, a third heat exchanger 5, and a fourth refrigerant one-way valve 21.

[0147] During specific operation, in the refrigerant circuit, the gaseous refrigerant is at high pressure after being compressed by the compressor 1. The high-pressure refrigerant enters the liquid storage and drying device 6 through the fifth control valve 13, the second heat exchanger 4 and the first control valve 18, and heats the internal gas of the air-conditioning box through the second heat exchanger 4 to lose enthalpy.

[0148] Next, the refrigerant enters the high-pressure side heat exchange channel in the internal heat exchanger 7, transfers the enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel, and then passes through the third expansion valve 16. The refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve, and becomes a low-pressure gas-liquid mixed state. Then the refrigerant enters the third heat exchanger 5, cools the internal gas of the air-conditioning box to dehumidify the vehicle, and obtains enthalpy.

[0149] Then, the refrigerant enters the low-pressure side heat exchange channel in the internal heat exchanger 7 through the fourth control valve 21. The refrigerant obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and passes through the saturation curve, causing the refrigerant to become gaseous. Finally, the low-pressure refrigerant returns to the compressor 1.

[0150] Figure 18 The changes in pressure and enthalpy experienced by the refrigerant in the first dehumidification mode are shown, and wherein the curve X represents the saturated state of the refrigerant fluid.

[0151] Specifically, the refrigerant fluid entering compressor 1 is in the gas phase. As it passes through compressor 1, it undergoes compression, as indicated by arrow 100, resulting in a high-pressure refrigerant fluid. The high-pressure refrigerant fluid then enters the second heat exchanger 4 and is transferred to the cabin, as indicated by arrow 200. At this point, the refrigerant fluid loses enthalpy while maintaining a constant pressure. The refrigerant fluid, with reduced enthalpy, enters the liquid-drying device 6. The refrigerant fluid exiting the liquid-drying device 6 is in the liquid phase and enters the internal heat exchanger 7, where it loses enthalpy, as indicated by arrow 10a. This enthalpy is then transferred to the low-pressure refrigerant fluid, as indicated by arrow 10b.

[0152] The high-pressure refrigerant then passes through the third expansion valve 16. The high-pressure refrigerant fluid experiences an isenthalpic pressure drop, indicated by arrow 120, and crosses the saturation curve X, causing it to switch to a gas-liquid mixture state, now at a low pressure. The low-pressure refrigerant fluid then passes through the third heat exchanger 5, where it gains enthalpy, as indicated by arrow 160, while cooling the internal air flow. The low-pressure refrigerant fluid then passes through the internal heat exchanger 7, where it gains enthalpy, as indicated by arrow 10b, from the high-pressure refrigerant fluid passing through the internal heat exchanger 7 and crosses the saturation curve X, causing it to switch to a gaseous state. The low-pressure refrigerant fluid then returns to the compressor 1.

[0153] 8. Second dehumidification mode;

[0154] Combine Figure 19 As shown in , the thermal management system of this embodiment has a second dehumidification mode. When the thermal management system is in the heat pump + battery heating mode, the refrigerant circuit is mainly composed of a compressor 1, a fifth refrigerant stop valve 13, a second heat exchanger 4, a first refrigerant one-way valve 18, a liquid storage drying device 6, an internal heat exchanger 7, a third expansion valve 16, a third heat exchanger 5, a fourth refrigerant one-way valve 21, a first expansion valve 14, a dual-fluid heat exchanger 3, a first heat exchanger 2, and a fourth refrigerant stop valve 12.

[0155] During specific operation, in the refrigerant circuit, the gaseous refrigerant is at high pressure after being compressed by the compressor 1. The high-pressure refrigerant enters the liquid storage and drying device 6 through the fifth control valve 13, the second heat exchanger 4 and the first control valve 18, and heats the internal gas of the air-conditioning box through the second heat exchanger 4 to lose enthalpy.

[0156] Then, the refrigerant enters the high-pressure side heat exchange channel in the internal heat exchanger 7, transfers the enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel, and the refrigerant is divided into two paths. One path of refrigerant passes through the third expansion valve 16, and the refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve, and becomes a low-pressure gas-liquid mixed state. Then the refrigerant enters the third heat exchanger 5, cools the internal gas of the air-conditioning box to dehumidify the interior of the vehicle, and obtains enthalpy; the other path of refrigerant passes through the first expansion valve 14, and the refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve, and becomes a low-pressure gas-liquid mixed state. Then the refrigerant enters the dual-fluid heat exchanger 3 and the first heat exchanger 2, and obtains enthalpy by absorbing heat from the outside air through the first heat exchanger 2, or obtains enthalpy by absorbing heat from the motor through the dual-fluid heat exchanger 3.

[0157] Then, the two refrigerants pass through the fourth control valve 21 and the fourth control valve 12 respectively, and enter the low-pressure side heat exchange channel in the internal heat exchanger 7. The refrigerant obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and passes through the saturation curve, causing the refrigerant to become gaseous. Finally, the low-pressure refrigerant returns to the compressor 1.

[0158] Figure 20 The changes in pressure and enthalpy experienced by the refrigerant in the first dehumidification mode are shown, and wherein the curve X represents the saturated state of the refrigerant fluid.

[0159] Specifically, the refrigerant fluid entering compressor 1 is in the gas phase. As it passes through compressor 1, it undergoes compression, as indicated by arrow 100, resulting in a high-pressure state. The high-pressure refrigerant fluid then enters second heat exchanger 4 and is transferred to the cabin, as indicated by arrow 200. At this point, the refrigerant fluid loses enthalpy while maintaining a constant pressure. The refrigerant fluid, with its enthalpy reduced, enters liquid storage and drying device 6, as indicated by arrow 4a.

[0160] The refrigerant then splits into two branches. The first branch passes through the third expansion valve 16, where it undergoes an isenthalpic pressure drop, indicated by arrow 500. This results in a gas-liquid mixture and crosses the saturation curve X, where the refrigerant remains a gas-liquid mixture at a low pressure. The low-pressure refrigerant then passes through the third heat exchanger 5, absorbing heat from the cabin and gaining enthalpy. At this point, the refrigerant is in a two-phase state, as indicated by arrow 600, and then passes through the internal heat exchanger 7, as indicated by arrow 4b.

[0161] The second refrigerant branch fluid passes through first expansion valve 14, experiencing an isenthalpic pressure drop indicated by arrow 120. This results in a mixture of gas and liquid, and crosses saturation curve X. At this point, the refrigerant fluid remains a mixture of gas and liquid, at a low pressure. The low-pressure refrigerant then passes through two-fluid heat exchanger 3 and first heat exchanger 2, absorbing heat from the external air in first heat exchanger 2 or from the drive motor through two-fluid heat exchanger 3, thereby gaining enthalpy. At this point, the refrigerant is in a two-phase state, as indicated by arrow 160. It then enters internal heat exchanger 7 and gains enthalpy, at which point the refrigerant fluid is in the gas phase, as indicated by arrow 10b.

[0162] Finally, the two refrigerant branches merge at the connection point 29 and return to the compressor 1.

[0163] The thermal management system for electric vehicles of this embodiment adopts the above structure. Through the arrangement of the compressor 1, the first heat exchanger 2, the dual-fluid heat exchanger 3, the second heat exchanger 4, the third heat exchanger 5, the liquid storage and drying device 6, the internal heat exchanger 7, and the fourth heat exchanger 8, and through the control connection of multiple control valves, a directly reversible air-conditioning system can be formed.

[0164] At this time, the thermal management system of this embodiment is not only relatively simple in structure, but also can realize direct cooling and heating of the battery, thereby improving the heat exchange efficiency between the battery and the power battery. At the same time, based on the heat pump mode, it can also realize single cooling, dual cooling, heat pump + heat recovery, heat pump + battery heating and dehumidification and other working modes, thereby facilitating the promotion and application of heat pump management systems.

[0165] Example 2

[0166] This embodiment relates to a vehicle, which is an electric vehicle. The thermal management system for an electric vehicle according to the first embodiment is provided in the vehicle.

[0167] The vehicle of this embodiment is equipped with the thermal management system of embodiment 1, which can improve the heat exchange efficiency between the vehicle and the power battery, and can also realize multiple working modes such as heat pump, single cooling, dual cooling, heat pump + heat recovery, heat pump + battery heating and dehumidification, etc., which helps to improve the vehicle's thermal management effect and is beneficial to improving the vehicle's driving quality.

[0168] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A thermal management system for an electric vehicle, characterized in that: The refrigerant circuit of the thermal management system includes a compressor (1), a first heat exchanger (2), a two-fluid heat exchanger (3), a second heat exchanger (4), a third heat exchanger (5), a liquid storage and drying device (6), an internal heat exchanger (7), a fourth heat exchanger (8), a first control valve (9), a fourth control valve (12) and a first expansion valve (14); One end of the first heat exchanger (2) is connected to the outlet of the compressor (1) through a third control valve (11), and the other end of the first heat exchanger (2) is connected to the inlet of the liquid storage and drying device (6) through the dual-fluid heat exchanger (3) and a seventh control valve (19); one end of the second heat exchanger (4) is connected to the outlet of the compressor (1) through a fifth control valve (13), and the other end of the second heat exchanger (4) is connected to the inlet of the liquid storage and drying device (6) through a sixth control valve (18); The inlet of the high-pressure side heat exchange channel in the internal heat exchanger (7) is connected to the outlet of the liquid storage drying device (6), the outlet of the high-pressure side heat exchange channel in the internal heat exchanger (7) is connected to the inlet of the third heat exchanger (5) through the third expansion valve (16), the outlet of the third heat exchanger (5) is connected to the inlet of the low-pressure side heat exchange channel in the internal heat exchanger (7) through the ninth control valve (21), and the outlet of the low-pressure side heat exchange channel in the internal heat exchanger (7) is connected to the inlet of the compressor (1); One end of the fourth heat exchanger (8) is connected to the outlet of the compressor (1) through a fourth two-way expansion valve (17) and a second control valve (10), and the other end of the fourth heat exchanger (8) is divided into two parallel paths, one of which is connected to the outlet of the high-pressure side heat exchange channel of the internal heat exchanger (7) through the second expansion valve (15), and the other of which is connected to the inlet of the liquid storage drying device (6) through the eighth control valve (20); One end of the first control valve (9) is connected in parallel between the fourth two-way expansion valve (17) and the second control valve (10), and the other end of the first control valve (9) is connected to the inlet of the low-pressure side heat exchange channel of the internal heat exchanger (7). One end of the fourth control valve (12) is connected in parallel between the third control valve (11) and the first heat exchanger (2), and the other end of the fourth control valve (12) is connected to the inlet of the low-pressure side heat exchange channel of the internal heat exchanger (7). The inlet of the first expansion valve (14) is connected to the outlet of the high-pressure side heat exchange channel of the internal heat exchanger (7), and the outlet of the first expansion valve (14) is connected in parallel between the dual-fluid heat exchanger (3) and the seventh control valve (19); The first heat exchanger (2), the dual-fluid heat exchanger (3) and the fourth heat exchanger (8) are all reversible and can be selected as an evaporator or a condenser, and the refrigerant in the fourth heat exchanger (8) can directly exchange heat with the battery pack, and the refrigerant in the high-pressure side heat exchange channel and the low-pressure side heat exchange channel in the internal heat exchanger (7) can exchange heat.

2. The thermal management system for an electric vehicle according to claim 1, characterized in that: In the refrigerant circuit, the positions of the first heat exchanger (2) and the dual-fluid heat exchanger (3) are adjusted, and one end of the dual-fluid heat exchanger (3) is connected to the outlet of the compressor (1) through the third control valve (11), and the other end of the dual-fluid heat exchanger (3) is connected to the inlet of the liquid storage drying device (6) through the first heat exchanger (2) and the seventh control valve (19). One end of the fourth control valve (12) is connected in parallel between the third control valve (11) and the dual-fluid heat exchanger (3), and the outlet of the first expansion valve (14) is connected in parallel between the first heat exchanger (2) and the seventh control valve (19).

3. The thermal management system for an electric vehicle according to claim 2, characterized in that: The sixth control valve (18) is removed from the refrigerant circuit; The second heat exchanger (4) is connected in series to the outlet of the compressor (1), and the fifth control valve (13) is connected in parallel between the outlet of the second heat exchanger (4) and the liquid storage and drying device (6).

4. The thermal management system for an electric vehicle according to claim 2, characterized in that: The first heat exchanger (2) is removed from the refrigerant circuit; The coolant channel in the dual-fluid heat exchanger (3) can be communicated with a cooling channel in the drive motor and at least one of the low-temperature radiators.

5. The thermal management system for an electric vehicle according to claim 1, characterized in that: The thermal management system has a single air conditioning cooling mode; When the thermal management system is in the single air-conditioning refrigeration mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor (1) and is in high pressure, and the high-pressure refrigerant passes through the third control valve (11), the first heat exchanger (2), the dual-fluid heat exchanger (3) and the seventh control valve (19) and enters the liquid storage and drying device (6), and the refrigerant transfers enthalpy to the outside air at the first heat exchanger (2) and becomes liquid; Then, the refrigerant passes through the high-pressure side heat exchange channel in the internal heat exchanger (7) and transfers enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel. Then, the refrigerant passes through the third expansion valve (16), and the high-pressure refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve to become a low-pressure gas-liquid mixed state. Then, the low-pressure refrigerant enters the third heat exchanger (5), cools the cavity in the air-conditioning box and obtains enthalpy. Then, the low-pressure refrigerant passes through the ninth control valve (21) and enters the low-pressure side heat exchange channel in the internal heat exchanger (7), obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and passes through the saturation curve, causing the refrigerant to become gaseous. Finally, the low-pressure refrigerant returns to the compressor (1).

6. The thermal management system for an electric vehicle according to claim 5, characterized in that: The thermal management system has a single battery cooling mode; When the thermal management system is in the single-battery cooling mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor (1) and is in high pressure, and the high-pressure refrigerant passes through the third control valve (11), the first heat exchanger (2), the dual-fluid heat exchanger (3) and the seventh control valve (19) and enters the liquid storage and drying device (6), and the refrigerant transfers enthalpy to the outside air at the first heat exchanger (2) and becomes liquid; Then, the refrigerant passes through the high-pressure side heat exchange channel in the internal heat exchanger (7) and transfers enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel. Then, the refrigerant passes through the second expansion valve (15), and the high-pressure refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve to become a low-pressure gas-liquid mixed state. Then, the low-pressure refrigerant enters the fourth heat exchanger (8) to cool the battery and obtain enthalpy. Then, the refrigerant passes through the fourth two-way expansion valve (17) and the first control valve (9) to enter the low-pressure side heat exchange channel in the internal heat exchanger (7), and obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and passes through the saturation curve, causing the refrigerant to become a gaseous state. Finally, the low-pressure refrigerant returns to the compressor (1).

7. The thermal management system for an electric vehicle according to claim 6, characterized in that: The thermal management system has a dual cooling mode; When the thermal management system is in the dual cooling mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor (1) and is in high pressure, and the high-pressure refrigerant passes through the third control valve (11), the first heat exchanger (2), the dual-fluid heat exchanger (3) and the seventh control valve (19) and enters the liquid storage and drying device (6), and the refrigerant transfers enthalpy to the outside air at the first heat exchanger (2) and becomes liquid; Then, the refrigerant passes through the high-pressure side heat exchange channel in the internal heat exchanger (7) and transfers the enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel, and the refrigerant is divided into two paths, one path passes through the third expansion valve (16) and the third heat exchanger (5), and the other path passes through the second expansion valve (15) and the fourth heat exchanger (8). At the third expansion valve (16) and the second expansion valve (15), the high-pressure refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve to become a low-pressure gas-liquid mixed state. At the third heat exchanger (5), the refrigerant cools the cavity in the air-conditioning box and obtains enthalpy. At the fourth heat exchanger (8), the refrigerant cools the battery and obtains enthalpy. Then, the refrigerant passing through the ninth control valve (21) merges with the refrigerant passing through the first control valve (9), enters the low-pressure side heat exchange channel in the internal heat exchanger (7), obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and crosses the saturation curve, causing the refrigerant to become gaseous, and finally the low-pressure refrigerant returns to the compressor (1).

8. The thermal management system for an electric vehicle according to claim 1, characterized in that: The thermal management system has a heat pump mode; When the thermal management system is in the heat pump mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor (1) and is in high pressure. The high-pressure refrigerant passes through the fifth control valve (13), the second heat exchanger (4) and the sixth control valve (18) and enters the liquid storage and drying device (6), and heats the air in the air-conditioning box at the second heat exchanger (4) to lose enthalpy. Then, the refrigerant enters the high-pressure side heat exchange channel in the internal heat exchanger (7) and transfers the enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel. Then, the refrigerant passes through the first expansion valve (14), and the refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve, and becomes a low-pressure gas-liquid mixed state. Then, the refrigerant passes through the dual-fluid heat exchanger (3) and enters the first heat exchanger (2), where it absorbs heat from the outside air to obtain enthalpy. Then, the refrigerant passes through the fourth control valve (12) and enters the low-pressure side heat exchange channel in the internal heat exchanger (7). The refrigerant obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and passes through the saturation curve, causing the refrigerant to become gaseous. Finally, the low-pressure refrigerant returns to the compressor (1).

9. The thermal management system for an electric vehicle according to claim 1, characterized in that: The thermal management system has a heat pump + heat recovery mode; When the thermal management system is in the heat pump + heat recovery mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor (1) and is at high pressure. The high-pressure refrigerant passes through the fifth control valve (13), the second heat exchanger (4) and the sixth control valve (18) and enters the liquid storage and drying device (6), and heats the air in the air-conditioning box at the second heat exchanger (4) to lose enthalpy. Then, the refrigerant enters the high-pressure side heat exchange channel in the internal heat exchanger (7), transfers the enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel, and then the refrigerant passes through the first expansion valve (14), the refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve, and becomes a low-pressure gas-liquid mixed state, and then the refrigerant passes through the dual-fluid heat exchanger (3) into the first heat exchanger (2), and absorbs heat from the outside air through the first heat exchanger (2) to obtain enthalpy, and absorbs heat from the motor at the dual-fluid heat exchanger (3) to obtain enthalpy; Then, the refrigerant enters the low-pressure side heat exchange channel in the internal heat exchanger (7) through the fourth control valve (12), the refrigerant obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and passes through the saturation curve, causing the refrigerant to become gaseous, and finally the low-pressure refrigerant returns to the compressor (1).

10. The thermal management system for an electric vehicle according to claim 1, characterized in that: The thermal management system has a heat pump + battery heating mode; When the thermal management system is in the heat pump + battery heating mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor (1) and is at high pressure, and is divided into two paths. One path of high-pressure refrigerant passes through the second control valve (10), the fourth two-way expansion valve (17), the fourth heat exchanger (8) and the eighth control valve (20) and enters the liquid storage drying device (6), and loses enthalpy by heating the battery through the fourth heat exchanger (8); the other path of high-pressure refrigerant passes through the fifth control valve (13), the second heat exchanger (4) and the sixth control valve (18) and enters the liquid storage drying device (6), and loses enthalpy by heating the air in the air-conditioning box at the second heat exchanger (4). Then, the refrigerant flowing out of the liquid storage drying device (6) enters the high-pressure side heat exchange channel in the internal heat exchanger (7), and transfers the enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel. Then, the refrigerant passes through the first expansion valve (14), and the refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve, and becomes a low-pressure gas-liquid mixed state. Then, the refrigerant passes through the dual-fluid heat exchanger (3) and enters the first heat exchanger (2), and absorbs heat from the outside air through the first heat exchanger (2) to obtain enthalpy, and absorbs heat from the motor through the dual-fluid heat exchanger (3) to obtain enthalpy. Then, the refrigerant enters the low-pressure side heat exchange channel in the internal heat exchanger (7) through the fourth control valve (12), the refrigerant obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and passes through the saturation curve, causing the refrigerant to become gaseous, and finally the low-pressure refrigerant returns to the compressor (1).

11. The thermal management system for an electric vehicle according to claim 10, characterized in that: The fifth control valve (13) is a stop valve, and the sixth control valve (18) is a one-way valve; or the fifth control valve (13) is a stop valve, and the sixth control valve (18) is a two-way expansion valve; or the fifth control valve (13) is a two-way expansion valve, and the sixth control valve (18) is a one-way valve.

12. The thermal management system for an electric vehicle according to claim 1, wherein: The thermal management system has a first dehumidification mode; When the thermal management system is in the first dehumidification mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor (1) and is in high pressure. The high-pressure refrigerant passes through the fifth control valve (13), the second heat exchanger (4) and the sixth control valve (18) and enters the liquid storage and drying device (6), and heats the gas inside the air-conditioning box through the second heat exchanger (4) to lose enthalpy. Next, the refrigerant enters the high-pressure side heat exchange channel in the internal heat exchanger (7), transfers enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel, and then passes through the third expansion valve (16), the refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve, and becomes a low-pressure gas-liquid mixed state, and then the refrigerant enters the third heat exchanger (5), cools the air inside the air-conditioning box to dehumidify the vehicle, and obtains enthalpy; Then, the refrigerant enters the low-pressure side heat exchange channel in the internal heat exchanger (7) through the ninth control valve (21), and the refrigerant obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and passes through the saturation curve, causing the refrigerant to become gaseous, and finally the low-pressure refrigerant returns to the compressor (1).

13. The thermal management system for an electric vehicle according to claim 12, characterized in that: The thermal management system has a second dehumidification mode; When the thermal management system is in the second dehumidification mode, in the refrigerant circuit, the gaseous refrigerant is compressed by the compressor (1) and is in high pressure. The high-pressure refrigerant passes through the fifth control valve (13), the second heat exchanger (4) and the sixth control valve (18) and enters the liquid storage and drying device (6), and heats the gas inside the air-conditioning box through the second heat exchanger (4) to lose enthalpy. Then, the refrigerant enters the high-pressure side heat exchange channel in the internal heat exchanger (7), transfers the enthalpy to the low-pressure refrigerant in the low-pressure side heat exchange channel, and the refrigerant is divided into two paths. One path of refrigerant passes through the third expansion valve (16), and the refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve, and becomes a low-pressure gas-liquid mixed state. Then, the refrigerant enters the third heat exchanger (5), cools the internal gas of the air-conditioning box, dehumidifies the interior of the vehicle, and obtains enthalpy; the other path of refrigerant passes through the first expansion valve (14), and the refrigerant experiences an isenthalpic pressure drop and passes through the saturation curve, and becomes a low-pressure gas-liquid mixed state. Then, the refrigerant enters the dual-fluid heat exchanger (3) and the first heat exchanger (2), and absorbs heat from the outside air through the first heat exchanger (2) to obtain enthalpy, or absorbs heat from the motor through the dual-fluid heat exchanger (3) to obtain enthalpy; Then, the two refrigerants pass through the ninth control valve (21) and the fourth control valve (12) respectively, and enter the low-pressure side heat exchange channel in the internal heat exchanger (7). The refrigerant obtains enthalpy from the refrigerant in the high-pressure side heat exchange channel and passes through the saturation curve, causing the refrigerant to become gaseous. Finally, the low-pressure refrigerant returns to the compressor (1).

14. A vehicle, characterized in that: The vehicle is an electric vehicle, and the thermal management system for an electric vehicle according to any one of claims 1 to 13 is provided in the vehicle.

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