Heat pump air-conditioning system and vehicle

Abstract

The present disclosure relates to a heat pump air conditioning system and a vehicle. The system includes a compressor, an indoor condenser, an indoor evaporator, an outdoor heat exchanger, a first flow path and a second flow path that are selectively turned on or off. The outlet of the compressor is connected to the inlet of the indoor condenser and is connected to the inlet of the outdoor heat exchanger via the first flow path. The outlet of the indoor condenser is connected to the first refrigerant inlet of the first heat exchanger. The first refrigerant outlet of the first heat exchanger is connected to the inlet of the outdoor heat exchanger via the first expansion valve. The outlet of the outdoor heat exchanger is connected to the first refrigerant inlet of the second heat exchanger and is connected to the second refrigerant inlet of the first heat exchanger via the second flow path. The first refrigerant outlet of the second heat exchanger is connected to the inlet of the indoor evaporator via the second expansion valve. The outlet of the indoor evaporator and the second refrigerant outlet of the first heat exchanger are both connected to the second refrigerant inlet of the second heat exchanger. The second refrigerant outlet of the second heat exchanger is connected to the inlet of the compressor.

Description

Technical Field

[0001] The present disclosure relates to the technical field of heat pump air conditioning systems, and in particular, to a heat pump air conditioning system and a vehicle. Background Art

[0002] In the refrigeration condition of the existing vehicle heat pump air conditioning system, the high-temperature and high-pressure gaseous refrigerant discharged by the compressor releases heat to the outside atmosphere at the outdoor heat exchanger. After the heat release, the refrigerant passes through the throttle valve to throttle and depressurize, and then absorbs the heat of the passenger compartment in the indoor evaporator, thereby achieving the effect of cooling the passenger compartment. Since the refrigerant needs to release heat to the outside atmosphere through the outdoor heat exchanger before entering the evaporator, the heat exchange amount between the refrigerant and the outside atmosphere in the outdoor heat exchanger is affected by the ambient temperature. For example, when the outside ambient temperature is relatively high, the heat released by the refrigerant to the outside atmosphere in the outdoor heat exchanger is limited, resulting in poor refrigeration effect and refrigeration efficiency of the vehicle heat pump air conditioning system at high temperatures.

[0003] In the heating condition of the existing vehicle heat pump air conditioning system, the high-temperature and high-pressure gaseous refrigerant discharged by the compressor releases heat to the passenger compartment at the indoor condenser. After the heat release, the refrigerant passes through the throttle valve to throttle and depressurize, and then absorbs and transports the heat of the outside atmosphere in the outdoor heat exchanger, and then returns to the compressor. Since the refrigerant needs to transport the heat of the outside atmosphere before returning to the compressor, the heat exchange amount between the refrigerant and the outside atmosphere in the outdoor heat exchanger is affected by the ambient temperature. For example, when the outside ambient temperature is relatively low, the heat absorption of the refrigerant in the outdoor heat exchanger is limited, resulting in poor heating effect and heating efficiency of the vehicle heat pump air conditioning system at low temperatures. Summary of the Invention

[0004] The purpose of the present disclosure is to provide a heat pump air conditioning system and a vehicle using the heat pump air conditioning system to overcome the problems existing in the related art.

[0005] To achieve the above purpose, the present disclosure provides a heat pump air conditioning system, including a compressor, an indoor condenser, an indoor evaporator, an outdoor heat exchanger, a first heat exchanger, a second heat exchanger, a first expansion valve, a second expansion valve, a first flow path that selectively conducts or cuts off, and a second flow path that selectively conducts or cuts off.

[0006] The outlet of the compressor is connected to the inlet of the indoor condenser and is also connected to the inlet of the outdoor heat exchanger via the first flow path. The outlet of the indoor condenser is connected to the first refrigerant inlet of the first heat exchanger. The first refrigerant outlet of the first heat exchanger is connected to the inlet of the outdoor heat exchanger via the first expansion valve. The outlet of the outdoor heat exchanger is connected to the first refrigerant inlet of the second heat exchanger and is also connected to the second refrigerant inlet of the first heat exchanger via the second flow path. The first refrigerant outlet of the second heat exchanger is connected to the inlet of the indoor evaporator via the second expansion valve. The outlet of the indoor evaporator and the second refrigerant outlet of the first heat exchanger are both connected to the second refrigerant inlet of the second heat exchanger. The second refrigerant outlet of the second heat exchanger is connected to the inlet of the compressor.

[0007] Optionally, the heat pump air-conditioning system further includes a first liquid storage and drying tank and a second liquid storage and drying tank. The outlet of the indoor condenser is connected to the inlet of the first liquid storage and drying tank. The liquid outlet of the first liquid storage and drying tank is connected to the first refrigerant inlet of the first heat exchanger. The outlet of the outdoor heat exchanger is connected to the inlet of the second liquid storage and drying tank. The liquid outlet of the second liquid storage and drying tank is connected to the first refrigerant inlet of the second heat exchanger.

[0008] Optionally, the heat pump air-conditioning system further includes a subcooler located downstream of the second liquid storage and drying tank. The liquid outlet of the second liquid storage and drying tank is connected to the first refrigerant inlet of the second heat exchanger via the subcooler.

[0009] Optionally, the heat pump air-conditioning system further includes a third flow path that can be selectively opened or closed. The liquid outlet of the first liquid storage and drying tank is also connected to the inlet of the second expansion valve via the third flow path.

[0010] Optionally, the heat pump air-conditioning system further includes a third heat exchanger and a third expansion valve. The first refrigerant outlet of the second heat exchanger is also connected to the refrigerant inlet of the third heat exchanger via the third expansion valve. The refrigerant outlet of the third heat exchanger is connected to the second refrigerant inlet of the second heat exchanger. The first coolant outlet of the third heat exchanger is used to connect to the inlet of the vehicle's battery pack. The first coolant inlet of the third heat exchanger is used to connect to the outlet of the battery pack.

[0011] Optionally, the liquid outlet of the first liquid storage and drying tank is also connected to the inlet of the third expansion valve via the third flow path. The second coolant outlet of the third heat exchanger is used to connect to the inlet of the vehicle's electronic devices. The second coolant inlet of the third heat exchanger is used to connect to the outlet of the electronic devices.

[0012] Optionally, the heat pump air conditioning system further includes a check valve, and a first refrigerant outlet of the second heat exchanger is connected to inlets of the second expansion valve and the third expansion valve via the check valve.

[0013] Optionally, the electronic device includes at least one of a motor, a charger, a motor controller, and a DC-DC converter.

[0014] Optionally, a first cut-off valve is disposed on the first flow path, a second cut-off valve is disposed on the second flow path, and a third cut-off valve is disposed on the third flow path.

[0015] According to another aspect of the present disclosure, there is provided a vehicle including the above heat pump air conditioning system.

[0016] Compared with the prior art in which the refrigerant flowing out of the outlet of the indoor condenser directly flows through the expansion valve into the outdoor heat exchanger without experiencing a decrease in enthalpy value, and the refrigerant flowing out of the outlet of the outdoor heat exchanger flows into the compressor without experiencing an increase in enthalpy value, in this application, by providing a first heat exchanger, connecting a first refrigerant inlet of the first heat exchanger to the indoor condenser, connecting a second refrigerant inlet to the inlet of the outdoor heat exchanger through an expansion valve, connecting the second refrigerant inlet to the outlet of the outdoor heat exchanger, and connecting the second refrigerant inlet to the inlet of the compressor 1 through a second heat exchanger, on the one hand, it can increase the subcooling degree of the refrigerant flowing into the outdoor heat exchanger, improve the evaporation amount of the refrigerant in the outdoor heat exchanger (i.e., the heat absorption amount of absorbing heat from the external atmosphere), and is beneficial to the refrigerant absorbing more heat in the outdoor heat exchanger. On the other hand, it can increase the superheat degree of the refrigerant flowing out of the outdoor heat exchanger, improve the suction temperature and suction pressure at the compressor inlet, and thus can improve the heating capacity of the heat pump air conditioning system in a low-temperature environment, and solve the problem that the refrigerant absorbs insufficient heat due to environmental temperature limitations at the outdoor heat exchanger in a low ambient temperature situation.

[0017] Compared with the prior art solution where the refrigerant before entering the indoor evaporator only releases heat to the outside world through the outdoor heat exchanger and loses enthalpy, the heat pump air-conditioning system provided by the present disclosure sets up a second heat exchanger to enable the refrigerant flowing out of the outdoor heat exchange outlet to exchange heat with the refrigerant flowing out of the indoor evaporator outlet in the second heat exchanger, further dissipating heat and cooling down the refrigerant flowing out of the outdoor heat exchanger outlet. That is, the refrigerant can release heat twice through the outdoor heat exchanger and the second heat exchanger before entering the indoor evaporator, solving the problem that the amount of heat released by the refrigerant at the outdoor heat exchanger is insufficient due to the influence of the ambient temperature in the case of a relatively high ambient temperature. In this way, the enthalpy value and the released heat of the refrigerant before entering the indoor evaporator are more, which is beneficial to increasing the subcooling degree of the refrigerant entering the indoor evaporator and is also beneficial to the inflow of a refrigerant with a lower temperature into the indoor evaporator, so that the heat pump air-conditioning system can still have good refrigeration effect and refrigeration efficiency in a high-temperature environment, realizing the rapid cooling of the occupant compartment. In other words, by setting up the second heat exchanger and enabling the refrigerant flowing out of the outdoor heat exchanger outlet to release heat in the second heat exchanger, the problem that the amount of heat released by the refrigerant in the outdoor heat exchanger is limited in a high-temperature environment, affecting the refrigeration effect and refrigeration efficiency, can be solved.

[0018] Other features and advantages of the present disclosure will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific implementation, they are used to explain the present disclosure, but do not constitute a limitation to the present disclosure. In the drawings:

[0020] Figure 1 is a schematic structural diagram of a heat pump air-conditioning system provided by an embodiment of the present disclosure;

[0021] Figure 2 is a schematic structural diagram of a heat pump air-conditioning system provided by another embodiment of the present disclosure;

[0022] Figure 3 is a schematic structural diagram of a heat pump air-conditioning system provided by an embodiment of the present disclosure, where the heat pump air-conditioning system is in the refrigeration mode, and the thick solid lines and arrows in the figure represent the flow paths and flow directions of the refrigerant and the coolant in this mode;

[0023] Figure 4 is a pressure-enthalpy diagram of the refrigerant of a heat pump air-conditioning system provided by an embodiment of the present disclosure in the refrigeration mode;

[0024] Figure 5It is a schematic structural diagram of a heat pump air-conditioning system provided by an embodiment of the present disclosure. Among them, the heat pump air-conditioning system is in the battery pack cooling mode, and the thick solid lines and arrows in the figure represent the flow paths and flow directions of the refrigerant and the coolant in this mode;

[0025] Figure 6 It is an enthalpy-pressure diagram of the refrigerant of the heat pump air-conditioning system provided by an embodiment of the present disclosure in the battery pack cooling mode;

[0026] Figure 7 It is a schematic structural diagram of a heat pump air-conditioning system provided by an embodiment of the present disclosure. Among them, the heat pump air-conditioning system is in the refrigeration and battery pack cooling mode, and the thick solid lines and arrows in the figure represent the flow paths and flow directions of the refrigerant and the coolant in this mode;

[0027] Figure 8 It is an enthalpy-pressure diagram of the refrigerant of the heat pump air-conditioning system provided by an embodiment of the present disclosure in the refrigeration and battery pack cooling mode;

[0028] Figure 9 It is a schematic structural diagram of a heat pump air-conditioning system provided by an embodiment of the present disclosure. Among them, the heat pump air-conditioning system is in the heat pump heating mode, and the thick solid lines and arrows in the figure represent the flow paths and flow directions of the refrigerant and the coolant in this mode;

[0029] Figure 10 It is an enthalpy-pressure diagram of the refrigerant of the heat pump air-conditioning system provided by an embodiment of the present disclosure in the heat pump heating mode;

[0030] Figure 11 It is a schematic structural diagram of a heat pump air-conditioning system provided by an embodiment of the present disclosure. Among them, the heat pump air-conditioning system is in the waste heat recovery mode, and the thick solid lines and arrows in the figure represent the flow paths and flow directions of the refrigerant and the coolant in this mode;

[0031] Figure 12 It is an enthalpy-pressure diagram of the refrigerant of the heat pump air-conditioning system provided by an embodiment of the present disclosure in the waste heat recovery mode;

[0032] Figure 13 It is a schematic structural diagram of a heat pump air-conditioning system provided by an embodiment of the present disclosure. Among them, the heat pump air-conditioning system is in the heat pump with waste heat recovery mode, and the thick solid lines and arrows in the figure represent the flow paths and flow directions of the refrigerant and the coolant in this mode;

[0033] Figure 14 It is an enthalpy-pressure diagram of the refrigerant of the heat pump air-conditioning system provided by an embodiment of the present disclosure in the heat pump with waste heat recovery mode;

[0034] Figure 15It is a schematic structural diagram of a heat pump air conditioning system provided by an embodiment of the present disclosure. Among them, the heat pump air conditioning system is in the first dehumidification mode, and the thick solid lines and arrows in the figure indicate the flow paths and flow directions of the refrigerant and the coolant in this mode;

[0035] Figure 16 It is an enthalpy-pressure diagram of the refrigerant of the heat pump air conditioning system provided by an embodiment of the present disclosure in the first dehumidification mode;

[0036] Figure 17 It is a schematic structural diagram of a heat pump air conditioning system provided by an embodiment of the present disclosure. Among them, the heat pump air conditioning system is in the second dehumidification mode, and the thick solid lines and arrows in the figure indicate the flow paths and flow directions of the refrigerant and the coolant in this mode;

[0037] Figure 18 It is an enthalpy-pressure diagram of the refrigerant of the heat pump air conditioning system provided by an embodiment of the present disclosure in the second dehumidification mode.

[0038] Description of reference numerals

[0039] 1 - Compressor; 2 - Indoor condenser; 3 - Indoor evaporator; 4 - Outdoor heat exchanger; 5 - First heat exchanger; 6 - Second heat exchanger; 7 - First expansion valve; 8 - Second expansion valve; 9 - First flow path; 10 - Second flow path; 11 - First liquid storage and dryer; 12 - Second liquid storage and dryer; 13 - Subcooler; 14 - Third flow path; 15 - Check valve; 16 - Third heat exchanger; 17 - Third expansion valve; 18 - First stop valve; 19 - Second stop valve; 20 - Third stop valve. Detailed description of the specific implementation mode

[0040] The following will describe the specific implementation mode of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific implementation mode described here is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0041] In the present disclosure, unless otherwise stated, the "connection" mentioned in the present disclosure can be a direct connection between two devices or apparatuses, or an indirect connection. The "flow path that can be selectively conducted or cut off" means that this flow path can achieve the conduction or truncation of the refrigerant.

[0042] Such as Figures 1 to 18As shown in the figure, the present disclosure provides a heat pump air conditioning system, including a compressor 1, an indoor condenser 2, an indoor evaporator 3, an outdoor heat exchanger 4, a first heat exchanger 5, a second heat exchanger 6, a first expansion valve 7, a second expansion valve 8, a first flow path 9 that can be selectively opened or closed, and a second flow path 10 that can be selectively opened or closed. Among them, the outlet of the compressor 1 is connected to the inlet of the indoor condenser 2 and is also connected to the inlet of the outdoor heat exchanger 4 via the first flow path 9. The outlet of the indoor condenser 2 is connected to the first refrigerant inlet of the first heat exchanger 5. The first refrigerant outlet of the first heat exchanger 5 is connected to the inlet of the outdoor heat exchanger 4 via the first expansion valve 7. The outlet of the outdoor heat exchanger 4 is connected to the first refrigerant inlet of the second heat exchanger 6 and is also connected to the second refrigerant inlet of the first heat exchanger 5 via the second flow path 10. The first refrigerant outlet of the second heat exchanger 6 is connected to the inlet of the indoor evaporator 3 via the second expansion valve 8. The outlet of the indoor evaporator 3 and the second refrigerant outlet of the first heat exchanger 5 are both connected to the second refrigerant inlet of the second heat exchanger 6. The second refrigerant outlet of the second heat exchanger 6 is connected to the inlet of the compressor 1. By controlling the opening or closing of the first flow path 9 and the second flow path 10, the above heat pump air conditioning system can have a heat pump heating mode or a refrigeration mode.

[0043] In the heat pump heating mode, as Figure 9 shown, the first flow path 9 is closed and the second flow path 10 is opened. The compressor 1, the indoor condenser 2, the first refrigerant inlet of the first heat exchanger 5, the first refrigerant outlet of the first heat exchanger 5, the first expansion valve 7, the outdoor heat exchanger 4, the second refrigerant inlet of the first heat exchanger 5, the second refrigerant outlet of the first heat exchanger 5, and the second heat exchanger 6 are sequentially connected in series to form a refrigerant circuit. The high-temperature and high-pressure gaseous refrigerant discharged from the outlet of the compressor 1 flows into the indoor condenser 2 and releases heat to the passenger compartment in the indoor condenser 2, thereby increasing the temperature of the passenger compartment and realizing heating of the passenger compartment. The refrigerant with a reduced enthalpy value after heat release flowing out from the outlet of the indoor condenser 2 flows into the first heat exchanger 5 from the first refrigerant inlet of the first heat exchanger 5 and releases heat to the refrigerant flowing into the first heat exchanger 5 from the second refrigerant inlet of the first heat exchanger 5 and loses enthalpy (as shown by the arrow 500a in Figure 10 ). The refrigerant flowing out from the first refrigerant outlet of the first heat exchanger 5 is throttled and depressurized in the first expansion valve 7 to become a low-temperature and low-pressure gas-liquid two-phase refrigerant. This low-temperature and low-pressure gas-liquid two-phase refrigerant absorbs heat from the outside atmosphere and obtains enthalpy in the outdoor heat exchanger 4. The refrigerant flowing out from the outlet of the outdoor heat exchanger 4 flows into the first heat exchanger 5 via the second flow path 10 and absorbs the heat released by the refrigerant flowing into the first heat exchanger 5 from the outlet of the indoor condenser 2 in the first heat exchanger 5 and obtains enthalpy again (as shown by the arrow in Figure 10Finally, the refrigerant flowing out of the second refrigerant outlet of the first heat exchanger 5 returns to the compressor 1. Here, no refrigerant flows into the second refrigerant inlet of the second heat exchanger 6, and the refrigerant does not exchange heat in the second heat exchanger 6, and the second heat exchanger 6 is used as a flow passage.

[0044] Compared with the technical solution in the prior art that the refrigerant flowing out of the outlet of the indoor condenser does not experience enthalpy reduction but directly flows into the outdoor heat exchanger through the expansion valve, and the refrigerant flowing out of the outlet of the outdoor heat exchanger does not experience enthalpy increase but flows into the compressor, the present application sets a first heat exchanger 5, and connects the first refrigerant inlet of the first heat exchanger 5 to the indoor condenser 2, the second refrigerant inlet is connected to the inlet of the outdoor heat exchanger 4 through the expansion valve, the second refrigerant inlet is connected to the outlet of the outdoor heat exchanger 4, and the second refrigerant inlet is connected to the inlet of the compressor 1 through the second heat exchanger 6. On the one hand, it can increase the supercooling of the refrigerant flowing into the outdoor heat exchanger 4, increase the evaporation amount of the refrigerant in the outdoor heat exchanger 4 (that is, the amount of heat absorbed from the outside atmosphere), which is beneficial for the refrigerant to absorb more heat in the outdoor heat exchanger 4. On the other hand, it can increase the superheat of the refrigerant flowing out of the outdoor heat exchanger 4, increase the suction temperature and suction pressure at the inlet of the compressor 1, and then improve the heating capacity of the heat pump air-conditioning system in a low temperature environment, and solve the problem of insufficient heat absorption of the refrigerant at the outdoor heat exchanger 4 due to the limitation of the ambient temperature when the ambient temperature is low.

[0045] In cooling mode, Figure 3 As shown, the first flow path 9 is connected, the second flow path 10 is closed, and the compressor 1, the outdoor heat exchanger 4, the first refrigerant inlet of the second heat exchanger 6, the first refrigerant outlet of the second heat exchanger 6, the second expansion valve 8, the indoor evaporator 3, the second refrigerant inlet of the second heat exchanger 6, and the second refrigerant outlet of the second heat exchanger 6 are connected in series in sequence to form a refrigerant circuit. The high-temperature and high-pressure gaseous refrigerant discharged from the outlet of the compressor 1 flows into the outdoor heat exchanger 4, and dissipates heat to the outside atmosphere in the outdoor heat exchanger 4. The refrigerant loses enthalpy in the outdoor heat exchanger 4, that is, the refrigerant enthalpy value decreases (such as Figure 4 As shown by the arrow 400 in FIG. 1 , the refrigerant flowing out of the outlet of the outdoor heat exchanger 4 flows into the second heat exchanger 6 through the first refrigerant inlet of the second heat exchanger 6, and releases heat in the second heat exchanger 6 to the refrigerant flowing in from the second refrigerant inlet of the second heat exchanger 6. The refrigerant flowing into the second heat exchanger 6 from the outlet of the outdoor heat exchanger 4 loses enthalpy again, and the enthalpy value is further reduced (as shown in FIG. 1 ). Figure 4As shown by the arrow 600a in [description], the refrigerant after losing enthalpy flowing out from the first refrigerant outlet of the second heat exchanger 6 becomes a low-temperature and low-pressure gas-liquid two-phase refrigerant after throttling and pressure reduction by the first expansion valve 7. This low-temperature and low-pressure gas-liquid two-phase refrigerant absorbs the heat of the air in the passenger compartment in the indoor evaporator 3, reducing the temperature in the passenger compartment to achieve passenger compartment refrigeration. The refrigerant after absorbing heat flowing out from the outlet of the indoor evaporator 3 flows into the second heat exchanger 6, and obtains the enthalpy lost by the refrigerant flowing into the second heat exchanger 6 from the outlet of the outdoor heat exchanger 4. The refrigerant flowing out from the second refrigerant outlet of the second heat exchanger 6 finally returns to the compressor 1.

[0046] Compared with the prior art in which the refrigerant before entering the indoor evaporator only releases heat to the outside and loses enthalpy through the outdoor heat exchanger, the heat pump air-conditioning system provided by the present disclosure enables the refrigerant flowing out from the outlet of the outdoor heat exchanger 4 to exchange heat with the refrigerant flowing out from the outlet of the indoor evaporator 3 in the second heat exchanger 6, so that the refrigerant flowing out from the outlet of the outdoor heat exchanger 4 further dissipates heat and cools down. That is, the refrigerant can release heat twice through the outdoor heat exchanger 4 and the second heat exchanger 6 before entering the indoor evaporator 3, solving the problem that the amount of heat released by the refrigerant at the outdoor heat exchanger 4 is insufficient due to the influence of the ambient temperature in a high ambient temperature situation. In this way, the enthalpy value lost and the heat released by the refrigerant before entering the indoor evaporator 3 are more, which is beneficial to increasing the subcooling degree of the refrigerant entering the indoor evaporator 3 and is beneficial to the indoor evaporator 3 flowing into a refrigerant with a lower temperature, so that the heat pump air-conditioning system can still have good refrigeration effect and refrigeration efficiency in a high-temperature environment, realizing the rapid cooling of the passenger compartment. In other words, by providing the second heat exchanger 6 and enabling the refrigerant flowing out from the outlet of the outdoor heat exchanger 4 to release heat in the second heat exchanger 6, the problem that the amount of heat released by the refrigerant in the outdoor heat exchanger 4 is limited in a high-temperature environment and affects the refrigeration effect and refrigeration efficiency can be solved.

[0047] In addition, before the refrigerant returns to the compressor 1, it is necessary to ensure as much as possible that the gaseous refrigerant flows into the compressor 1, because once the liquid refrigerant flows into the compressor 1, it will cause the compressor 1 to experience liquid slugging, affecting the service life of the compressor 1. In the prior art, in order to ensure as much as possible that the gaseous refrigerant flows into the compressor, a gas-liquid separation device is usually provided at the inlet of the compressor. In this way, the refrigerant returning to the compressor will first pass through the gas-liquid separation device for gas-liquid separation and then return to the compressor. However, since the gas-liquid separation device cannot completely separate the gaseous refrigerant and the liquid refrigerant, a small amount of liquid refrigerant will still be carried in the gaseous refrigerant separated by the gas-liquid separation device. Therefore, in the prior art, to solve the above problem, the superheat degree of the refrigerant at the inlet of the compressor is usually controlled so that the superheat degree of the refrigerant at the compressor inlet is 0, that is, the refrigerant at the compressor inlet is located on the refrigerant saturation vapor line (refer to Figure 4the saturated vapor line shown in ), thereby causing the refrigerant to phase-change into a pure gaseous refrigerant, thus avoiding liquid slugging of the compressor caused by a small amount of liquid refrigerant carried in the gaseous refrigerant separated by the gas-liquid separation device. However, the superheat control of the refrigerant usually requires complex calculations to control components such as the expansion valve and the compressor, making the control of the heat pump air-conditioning system very complex.

[0048] However, in the present application, for the heat pump heating mode, the refrigerant can absorb heat and obtain enthalpy in the first heat exchanger 5 before returning to the compressor 1, which enables the refrigerant to cross the saturated vapor line (as shown by the arrow 500b in ) Figure 10 so that the refrigerant is in the superheated steam region, that is, the refrigerant is in a pure gaseous state; for the refrigeration mode, the refrigerant can absorb heat and obtain enthalpy in the second heat exchanger 6 before returning to the compressor 1, which enables the refrigerant to cross the saturated vapor line (as shown by the arrow 600b in ) Figure 4 so that the refrigerant is in the superheated steam region, that is, the refrigerant is in a pure gaseous state. In this way, for both the heat pump heating mode and the refrigeration mode, complex superheat control is not required, and the refrigerant entering the compressor 1 can be a pure gaseous refrigerant, avoiding liquid slugging of the compressor 1 and reducing the control complexity of the heat pump air-conditioning system.

[0049] It can be understood that in the battery pack cooling mode, the refrigeration and battery pack cooling mode, the heat pump with waste heat recovery mode, and the first dehumidification mode mentioned below, the refrigerant obtains enthalpy and crosses the saturated vapor line to be in the superheated steam region in at least one of the first heat exchanger 5 and the second heat exchanger 6 before returning to the compressor 1. Therefore, for the battery pack cooling mode, the refrigeration and battery pack cooling mode, the heat pump with waste heat recovery mode, and the first dehumidification mode, complex superheat control is not required either.

[0050] To further increase the subcooling degree of the refrigerant flowing out of the outlet of the indoor condenser 2 in the heat pump heating mode, that is, to increase the subcooling degree of the refrigerant entering the outdoor heat exchanger 4, thereby further improving the heating effect and heating efficiency of the heat pump air-conditioning system provided by the present disclosure in a low-temperature environment, in an embodiment provided by the present disclosure, the heat pump air-conditioning system further includes a first liquid storage and drying tank 11. The outlet of the indoor condenser 2 is connected to the inlet of the first liquid storage and drying tank 11, and the liquid outlet of the first liquid storage and drying tank 11 is connected to the first refrigerant inlet of the first heat exchanger 5. The first liquid storage and drying tank 11 can cause the liquid refrigerant in the gas-liquid two-phase mixed refrigerant flowing out of the outlet of the indoor condenser 2 to flow into the first heat exchanger 5, thereby increasing the subcooling degree of the refrigerant entering the first heat exchanger 5, increasing the heat release amount of the refrigerant in the first heat exchanger 5, and further enabling the temperature of the refrigerant entering the outdoor heat exchanger 4 to be lower, so that the refrigerant can absorb more heat from the outside atmosphere, that is, transfer more heat from the outside to the heat pump air-conditioning system.

[0051] To further increase the supercooling degree of the refrigerant flowing out of the outlet of the outdoor heat exchanger 4 in the refrigeration mode, that is, to increase the supercooling degree of the refrigerant entering the indoor evaporator 3, as well as the refrigeration effect and refrigeration efficiency in a high-temperature environment, in an embodiment provided in the present disclosure, the heat pump air-conditioning system further includes a second liquid storage and dryer 12. The outlet of the outdoor heat exchanger 4 is connected to the inlet of the second liquid storage and dryer 12, and the liquid outlet of the second liquid storage and dryer 12 is connected to the first refrigerant inlet of the second heat exchanger 6. The second liquid storage and dryer 12 can enable the liquid refrigerant in the gas-liquid two-phase mixed refrigerant flowing out of the outlet of the outdoor heat exchanger 4 to flow into the second heat exchanger 6, thereby increasing the supercooling degree of the refrigerant entering the second heat exchanger 6, increasing the heat release amount of the refrigerant in the second heat exchanger 6, and further enabling the temperature of the refrigerant entering the indoor evaporator 3 to be lower, enabling the refrigerant to absorb more heat in the occupant compartment, and realizing the rapid cooling of the occupant compartment.

[0052] Optionally, the heat pump air-conditioning system may further include a subcooler 13 located downstream of the second liquid storage and dryer 12. The liquid outlet of the second liquid storage and dryer 12 is connected to the first refrigerant inlet of the second heat exchanger 6 via the subcooler 13. Here, the subcooler 13 can further cool the liquid refrigerant flowing out of the liquid outlet of the second liquid storage and dryer 12, thereby further increasing the supercooling degree of the refrigerant entering the second heat exchanger 6.

[0053] To enable the heat pump air-conditioning system provided in the present disclosure to have more working modes to meet different needs of users, optionally, the heat pump air-conditioning system may further include a third flow path 14 that can be selectively conducted or cut off. The liquid outlet of the first liquid storage and dryer 11 is also connected to the inlet of the second expansion valve 8 via the third flow path 14. In this way, by controlling the conduction of the third flow path 14, the refrigerant flowing out of the outlet of the indoor condenser 2 can flow through the first liquid storage and dryer 11 and the second expansion valve 8 in sequence and then flow into the indoor evaporator 3. When the third flow path 14 is conducted, by controlling the conduction or cut-off of the first flow path 9 and the second flow path 10, the heat pump air-conditioning system provided in the present disclosure can have a first dehumidification mode and a second dehumidification mode.

[0054] Specifically, in the first dehumidification mode, such as Figure 15As shown, the first flow path 9 is cut off, the second flow path 10 is connected, and the third flow path 14 is connected; the compressor 1, the indoor condenser 2, the first liquid storage drying tank 11, the first refrigerant inlet of the first heat exchanger 5, the first refrigerant outlet of the first heat exchanger 5, the first expansion valve 7, the outdoor heat exchanger 4, the second refrigerant inlet of the first heat exchanger 5, the second refrigerant outlet of the first heat exchanger 5, the second refrigerant inlet of the second heat exchanger 6, and the second refrigerant outlet of the second heat exchanger 6 are connected in series in sequence to form a refrigerant circuit; the compressor 1, the indoor condenser 2, the first liquid storage drying tank 11, the second expansion valve 8, the indoor evaporator 3, the second refrigerant inlet of the second heat exchanger 6, and the second refrigerant outlet of the second heat exchanger 6 are connected in series in sequence to form another refrigerant circuit. In the first dehumidification mode, the high-temperature and high-pressure gaseous refrigerant discharged from the outlet of the compressor 1 enters the indoor condenser 2 and releases heat to the passenger compartment in the indoor condenser 2. The gas-liquid two-phase mixed refrigerant flowing out of the outlet of the indoor condenser 2 is separated into gaseous and liquid states in the first liquid storage dryer 11. The liquid refrigerant flows out of the liquid outlet of the first liquid storage dryer 11 and is divided into two streams. One stream of refrigerant flows into the indoor evaporator 3 after being throttled and reduced in pressure by the second expansion valve 8. When the relatively high-temperature humid air in the passenger compartment meets the relatively low-temperature indoor evaporator 3, the indoor evaporator 3 releases heat to the passenger compartment. The surface of the evaporator 3 condenses into water droplets, forming condensed water, thereby reducing the air humidity in the passenger compartment; another refrigerant flows into the first heat exchanger 5 and releases heat and loses enthalpy in the first heat exchanger 5, then flows into the outdoor heat exchanger 4 after throttling and reducing pressure through the first expansion valve 7, absorbs heat from the outside in the outdoor heat exchanger 4, and the refrigerant flowing out of the outlet of the outdoor heat exchanger 4 enters the first heat exchanger 5 and absorbs heat in the first heat exchanger 5 to obtain enthalpy, and then flows back to the compressor 1 after the second refrigerant outlet of the first heat exchanger 5 and the refrigerant flowing out of the outlet of the indoor evaporator 3 merge. Since the indoor evaporator 3 and the indoor condenser 2 work at the same time, the temperature in the passenger compartment can be balanced while dehumidifying the passenger compartment.

[0055] In the second dehumidification mode, Figure 17 As shown, the first flow path 9 is cut off, the second flow path 10 is cut off, and the third flow path 14 is connected. The compressor 1, the indoor condenser 2, the first liquid storage dryer 11, the second expansion valve 8, the indoor evaporator 3, the second refrigerant inlet of the second heat exchanger 6, and the second refrigerant outlet of the second heat exchanger 6 are sequentially connected in series to form a refrigerant circuit. In this mode, all the refrigerant flowing out of the liquid outlet of the first liquid storage dryer 11 flows out of the indoor evaporator 3 after being throttled and reduced in pressure by the second expansion valve 8.

[0056] The difference between the first dehumidification mode and the second dehumidification mode lies in whether the refrigerant flowing out of the liquid outlet of the first liquid storage dryer 11 partially passes through the first heat exchanger 5 and the first expansion valve 7 in sequence and flows into the outdoor heat exchanger 4, and absorbs the heat of the external atmosphere in the outdoor heat exchanger 4, thereby transferring the heat in the external environment. Since in the first dehumidification mode, the refrigerant flowing out of the liquid outlet of the first liquid storage dryer 11 will be divided into two streams. One stream of refrigerant passes through the first heat exchanger 5 and the first expansion valve 7 in sequence and flows into the outdoor heat exchanger 4 to transfer the heat in the external environment. While in the second dehumidification mode, the refrigerant flowing out of the liquid outlet of the first liquid storage dryer 11 does not flow into the outdoor heat exchanger 4, but all flows into the indoor evaporator 3 and does not transfer the heat in the external environment. Therefore, the environmental temperature applicable to the first dehumidification mode can be lower than the environmental temperature applicable to the second dehumidification mode. For example, the first dehumidification mode can be applied to the case where the environmental temperature is 5°C - 10°C, and the second dehumidification mode can be applied to the case where the environmental temperature is 10°C - 15°C. By setting the first dehumidification mode and the second dehumidification mode, the heat pump air-conditioning system can operate different dehumidification modes according to different environmental temperatures, thereby minimizing the influence of the external environmental temperature on the dehumidification effect.

[0057] In the field of electric vehicle technology, when vehicle manufacturers design electric vehicles, they strive to continuously shorten the charging time of the battery pack. And the shortening of the battery pack charging time means that the battery pack generates more heat during charging, the battery pack temperature is higher, and the battery pack needs to be quickly cooled in order to keep the temperature of the battery pack within its suitable operating temperature range while shortening the charging time of the battery pack.

[0058] To meet the requirement that the battery pack needs to be quickly cooled during fast charging, the heat pump air-conditioning system can also include a third heat exchanger 16 and a third expansion valve 17. The first refrigerant outlet of the second heat exchanger 6 is also connected to the refrigerant inlet of the third heat exchanger 16 via the third expansion valve 17. The refrigerant outlet of the third heat exchanger 16 is connected to the second refrigerant inlet of the second heat exchanger 6. The first coolant outlet of the third heat exchanger 16 is used to connect to the inlet of the battery pack of the vehicle, and the first coolant inlet of the third heat exchanger 16 is used to connect to the outlet of the battery pack.

[0059] In the battery pack cooling mode, such as Figure 5As shown, the first flow path 9 is connected, the second flow path 10 is closed, the compressor 1, the outdoor heat exchanger 4, the second liquid storage drying tank 12, the first refrigerant inlet of the second heat exchanger 6, the first refrigerant outlet of the second heat exchanger 6, the third expansion valve 17, the third heat exchanger 16, the second refrigerant inlet of the second heat exchanger 6, and the second refrigerant outlet of the second heat exchanger 6 are sequentially connected in series to form a refrigerant circuit. The gas-liquid two-phase mixed refrigerant flowing out of the outlet of the outdoor heat exchanger 4 is divided into gas and liquid in the second liquid storage drying tank 12, the liquid refrigerant flows into the second heat exchanger 6 and releases heat and loses enthalpy in the second heat exchanger 6, the refrigerant flowing out of the first refrigerant outlet of the second heat exchanger 6 enters the third heat exchanger 16 after throttling and reducing the pressure by the third expansion valve 17, and absorbs the heat of the coolant in the third heat exchanger 16, so that the first coolant outlet of the third heat exchanger 16 can flow out low-temperature coolant, which is used to absorb the heat of the battery pack, so as to achieve the purpose of using the cold capacity of the heat pump air conditioning system to cool the battery pack. In the battery pack cooling mode, the second liquid storage drying tank 12 and the second heat exchanger 6 can both increase the supercooling degree of the refrigerant flowing into the third heat exchanger 16, so that the refrigerant in the third heat exchanger 16 can absorb more heat, thereby achieving rapid cooling of the battery pack.

[0060] The battery pack cooling mode can be operated simultaneously with the refrigeration mode, so that the heat pump air conditioning system provided by the present disclosure can have a hybrid mode of refrigeration and battery pack cooling mode. Figure 7 As shown, in the refrigeration and battery pack cooling mode, the refrigerant flowing out from the first refrigerant outlet of the second heat exchanger 6 is divided into two streams, one stream flows into the indoor evaporator 3 after throttling and reducing the pressure through the second expansion valve 8, and absorbs the heat of the passenger compartment; the other stream flows into the third heat exchanger 16 after throttling and reducing the pressure through the third expansion valve 17, and absorbs the heat of the high-temperature coolant after absorbing heat from the battery pack, thereby realizing the cooling of the battery pack and the cooling of the passenger compartment at the same time.

[0061] When the outdoor ambient temperature is low, the amount of heat that the refrigerant can absorb at the outdoor heat exchanger 4 is limited, which can easily affect the heat release effect of the refrigerant at the indoor condenser 2 and the heating capacity of the passenger compartment. In order to enable the heat pump air-conditioning system to achieve the passenger compartment heating function without transporting external heat through the outdoor heat exchanger 4, in one embodiment provided in the present disclosure, the liquid outlet of the first liquid storage drying tank 11 is also connected to the inlet of the third expansion valve 17 via the third flow path 14, and the second coolant outlet of the third heat exchanger 16 is used to be connected to the inlet of the vehicle's electronic device, and the second coolant inlet of the third heat exchanger 16 is used to be connected to the outlet of the electronic device.

[0062] In this way, the heat pump air conditioning system can have a waste heat recovery mode, such as Figure 11As shown, in the waste heat recovery mode, the first flow path 9 is cut off, the second flow path 10 is cut off, and the third flow path 14 is connected. The compressor 1, the indoor condenser 2, the first liquid storage dryer 11, the third expansion valve 17, the third heat exchanger 16, the second refrigerant inlet of the second heat exchanger 6, and the second refrigerant outlet of the second heat exchanger 6 are sequentially connected in series to form a refrigerant circuit. In this mode, the high-temperature and high-pressure gaseous refrigerant discharged from the outlet of the compressor 1 flows into the indoor condenser 2, and releases heat to the passenger compartment at the indoor condenser 2 to achieve heating of the passenger compartment. The refrigerant flowing out of the outlet of the indoor condenser 2 flows into the first liquid storage dryer 11, and the liquid refrigerant flows out from the liquid outlet of the first liquid storage dryer 11 and flows into the third heat exchanger 16 after throttling and reducing the pressure by the third expansion valve 17, and absorbs the heat of the high-temperature coolant after absorbing heat from the electronic device in the third heat exchanger 16. The enthalpy value of the refrigerant in the third heat exchanger 16 increases, and the refrigerant flowing out of the refrigerant outlet of the third heat exchanger 16 finally returns to the compressor 1. In this mode, the refrigerant transfers the heat emitted by the electronic device during operation to the heat pump air conditioning system through the third heat exchanger 16, thereby cooling the electronic device and heating the passenger compartment using the heat of the electronic device.

[0063] In addition, the heat pump air conditioning system can also have a heat pump with waste heat recovery mode. In this mode, Figure 13 As shown, the first flow path 9 is cut off, the second flow path 10 is connected, and the third flow path 14 is connected. The refrigerant flowing out of the liquid outlet of the first liquid storage drying tank 11 is divided into two streams. One stream flows into the third heat exchanger 16 after throttling and reducing the pressure by the third expansion valve 17 to absorb the heat of the electronic device, and the other stream passes through the first heat exchanger 5 and the first expansion valve 7 in sequence and enters the outdoor heat exchanger 4 to absorb the heat of the outside atmosphere. That is to say, in the heat pump with waste heat recovery mode, the refrigerant transports the heat emitted by the electronic device during operation and the heat in the outside environment to the heat pump air conditioning system through the third heat exchanger 16 and the outdoor heat exchanger 4 respectively.

[0064] Here, it should be noted that the above-mentioned electronic devices refer to devices that need to use electricity to work and generate heat during the working process. For example, the electronic devices may include at least one of a motor, a charger, a motor controller, and a DC-DC converter. When the heat pump air-conditioning system is used in an electric vehicle, when the battery pack is in the charging state, the charger, the DC-DC converter, etc. will generate heat due to being in the working state, that is, the charger, the DC-DC converter, etc. have a heat dissipation requirement. At this time, if there is a heating requirement in the passenger compartment, the heat pump air-conditioning system can be set to the waste heat recovery mode or the heat pump with waste heat recovery mode, so as to recycle the heat of the charger, the DC-DC converter, etc. into the heat pump air-conditioning system while meeting the heat dissipation requirements of the charger, the DC-DC converter, etc., and improve the heating capacity of the heat pump air-conditioning system. When the electric vehicle is in the driving state, the motor converts the electrical energy of the battery pack into mechanical energy to drive the vehicle to travel, and the motor, etc. will generate heat. If there is a heating requirement in the passenger compartment at this time, the heat pump air-conditioning system can be set to the waste heat recovery mode or the heat pump with waste heat recovery mode, so as to recycle the heat of the motor into the heat pump air-conditioning system while realizing the heat dissipation and cooling of the motor.

[0065] Optionally, the heat pump air-conditioning system further includes a one-way valve 15, and the first refrigerant outlet of the second heat exchanger 6 is connected to the inlets of the second expansion valve 8 and the third expansion valve 17 via the one-way valve 15. As Figure 11 and Figure 17 shown, by setting the one-way valve 15, it is possible to prevent the refrigerant in the third heat exchanger 16 and the indoor evaporator 3 from flowing back into the second heat exchanger 6 in the above-mentioned waste heat recovery mode and the second dehumidification mode.

[0066] Optionally, the first heat exchanger 5 and the second heat exchanger 6 mentioned above may be plate heat exchangers or coaxial tubes, and the third heat exchanger 16 may be a plate heat exchanger or a tube heat exchanger. The present disclosure does not limit the specific types of the first heat exchanger 5, the second heat exchanger 6, and the third heat exchanger 16.

[0067] In addition, in order to realize the selective conduction or cutoff of the first flow path 9, the second flow path 10, and the third flow path 14, in an embodiment provided by the present disclosure, a first cutoff valve 18 may be provided on the first flow path 9, a second cutoff valve 19 may be provided on the second flow path 10, and a third cutoff valve 20 may be provided on the third flow path 14. In other embodiments, a first switching valve may also be provided on the first flow path 9, a second switching valve may be provided on the second flow path 10, and a third switching valve may be provided on the third flow path 14.

[0068] Next, taking the Figure 1 in the embodiment as an example, combined with Figures 3 to 18 to describe the cycle process and principle in the main working modes of the heat pump air-conditioning system provided by the present disclosure. Other embodiments (for example,Figure 2 ) The circulation process and principle of the system under Figure 1 are similar to

[0069] Mode 1: Refrigeration mode. In this mode, as Figure 3 shown, the first cut-off valve 18 is opened, the second cut-off valve 19 is closed, the third cut-off valve 20 is closed, the first expansion valve 7 is closed, the second expansion valve 8 is opened, and the third expansion valve 17 is closed. As Figure 3 and Figure 4 shown, the refrigerant entering the compressor 1 is pure gaseous refrigerant. The compressor 1 compresses the gaseous refrigerant so that the outlet of the compressor 1 discharges high-temperature and high-pressure gaseous refrigerant (as shown by the arrow 100 in Figure 4 ). This high-temperature and high-pressure gaseous refrigerant enters the outdoor heat exchanger 4 and releases enthalpy to the external atmosphere in the outdoor heat exchanger 4 (as shown by the arrow 400 in Figure 4 ). The gas-liquid two-phase mixed refrigerant flowing out of the outlet of the outdoor heat exchanger 4 flows into the second liquid storage and dryer 12. The liquid refrigerant (as shown by the point 120 in Figure 4 ) flows out of the liquid outlet of the second liquid storage and dryer 12 and into the second heat exchanger 6, and continues to release enthalpy in the second heat exchanger 6 (as shown by the arrow 600a in Figure 4 ). The liquid refrigerant flowing out of the first refrigerant outlet of the second heat exchanger 6 undergoes an isenthalpic pressure drop in the second expansion valve 8 and crosses the saturated liquid line (as shown by the arrow 800 in Figure 4 ). The low-temperature and low-pressure gas-liquid two-phase refrigerant flowing out of the outlet of the second expansion valve 8 absorbs heat from the passenger compartment in the indoor evaporator 3 and obtains enthalpy (as shown by the arrow 300 in Figure 4 ) to reduce the temperature of the passenger compartment and achieve refrigeration of the passenger compartment. The gas-liquid two-phase mixed refrigerant flowing out of the outlet of the indoor evaporator 3 flows into the second heat exchanger 6 and absorbs heat in the second heat exchanger 6 to obtain the enthalpy lost by the refrigerant flowing out of the liquid outlet of the second liquid storage and dryer 12 in the second heat exchanger 6 (as shown by the arrow 600b in Figure 4 ), thereby transforming the gas-liquid two-phase refrigerant flowing out of the indoor evaporator 3 into gaseous refrigerant. That is, the refrigerant flowing out of the second refrigerant outlet of the second heat exchanger 6 is located in the superheated steam zone. The pure gaseous refrigerant flowing out of the second refrigerant outlet of the second heat exchanger 6 finally returns to the compressor 1.

[0070] Mode 2: Battery pack cooling mode. In this mode, as Figure 5 shown, the first cut-off valve 18 is opened, the second cut-off valve 19 is closed, the third cut-off valve 20 is closed, the first expansion valve 7 is closed, the second expansion valve 8 is closed, and the third expansion valve 17 is opened. As Figure 5 and Figure 6As shown, the refrigerant entering the compressor 1 is pure gaseous refrigerant. The compressor 1 compresses this gaseous refrigerant so that the outlet of the compressor 1 discharges high-temperature and high-pressure gaseous refrigerant (as shown by the arrow 100 in Figure 6 ). This high-temperature and high-pressure gaseous refrigerant enters the outdoor heat exchanger 4 and releases enthalpy to the external atmosphere in the outdoor heat exchanger 4 (as shown by the arrow 400 in Figure 6 ). The gas-liquid two-phase mixed refrigerant flowing out of the outlet of the outdoor heat exchanger 4 flows into the second liquid storage and dryer 12. The liquid refrigerant (as shown by the dot 120 in Figure 6 ) flows out of the liquid outlet of the second liquid storage and dryer 12 and flows into the second heat exchanger 6, and continues to release enthalpy and lose heat in the second heat exchanger 6 (as shown by the arrow 600a in Figure 6 ). The liquid refrigerant flows out of the first refrigerant outlet of the second heat exchanger 6. This liquid refrigerant undergoes an isenthalpic pressure drop in the third expansion valve 17 and passes through the saturated liquid line (as shown by the arrow 170 in Figure 6 ). The low-temperature and low-pressure gas-liquid two-phase refrigerant flows out of the outlet of the third expansion valve 17. This low-temperature and low-pressure gas-liquid two-phase refrigerant absorbs the heat of the coolant and obtains enthalpy in the third heat exchanger 16 (as shown by the arrow 160 in Figure 6 ), so that the low-temperature coolant flows out of the first coolant outlet of the third heat exchanger 16. This low-temperature coolant can absorb the heat of the battery pack to achieve the cooling of the battery pack. The gas-liquid two-phase mixed refrigerant flowing out of the refrigerant outlet of the third heat exchanger 16 flows into the second heat exchanger 6 and absorbs heat in the second heat exchanger 6 to obtain the enthalpy lost by the refrigerant flowing out of the liquid outlet of the second liquid storage and dryer 12 in the second heat exchanger 6 (as shown by the arrow 600b in Figure 6 ), so that the gas-liquid two-phase refrigerant flowing out of the refrigerant outlet of the third heat exchanger 16 is transformed into gaseous refrigerant. That is, the refrigerant flowing out of the second refrigerant outlet of the second heat exchanger 6 is located in the superheated steam region. This pure gaseous refrigerant flowing out of the second refrigerant outlet of the second heat exchanger 6 finally returns to the compressor 1.

[0071] Mode 3: Refrigeration and battery pack cooling mode. In this mode, as shown in Figure 7 , the first cut-off valve 18 is opened, the second cut-off valve 19 is closed, the third cut-off valve 20 is closed, the first expansion valve 7 is closed, the second expansion valve 8 is opened, and the third expansion valve 17 is opened. As shown in Figure 7 and Figure 8 , the refrigerant entering the compressor 1 is pure gaseous refrigerant. The compressor 1 compresses this gaseous refrigerant so that the outlet of the compressor 1 discharges high-temperature and high-pressure gaseous refrigerant (as shown by the arrow 100 in Figure 8 ), this high-temperature and high-pressure gaseous refrigerant enters the outdoor heat exchanger 4 and releases enthalpy to the external atmosphere in the outdoor heat exchanger 4 (as shown by the arrow 400 in Figure 8as indicated by the arrow 400 in the figure), the gas-liquid two-phase mixed refrigerant flowing out of the outlet of the outdoor heat exchanger 4 flows into the second liquid storage and dryer 12, and the liquid refrigerant (such as Figure 8 as indicated by the point 120 in the figure) flows out of the second liquid storage and dryer 12 and into the second heat exchanger 6, and continues to release heat and lose enthalpy in the second heat exchanger 6 (such as Figure 8 as indicated by the arrow 600a in the figure), the liquid refrigerant flows out of the first refrigerant outlet of the second heat exchanger 6, and the liquid refrigerant is divided into two streams. One stream undergoes an isenthalpic pressure drop in the second expansion valve 8 and crosses the saturated liquid line (such as Figure 8 as indicated by the arrow 800 in the figure), the low-temperature and low-pressure gas-liquid two-phase refrigerant flows out of the outlet of the second expansion valve 8, and the low-temperature and low-pressure gas-liquid two-phase refrigerant absorbs the heat of the passenger compartment and obtains enthalpy in the indoor evaporator 3 (such as Figure 8 as indicated by the arrow 300 in the figure), so as to reduce the temperature of the passenger compartment and achieve the refrigeration of the passenger compartment; the other stream undergoes an isenthalpic pressure drop in the third expansion valve 17 and crosses the saturated liquid line (such as Figure 8 as indicated by the arrow 170 in the figure), the low-temperature and low-pressure gas-liquid two-phase refrigerant flows out of the outlet of the third expansion valve 17, and the low-temperature and low-pressure gas-liquid two-phase refrigerant absorbs the heat of the coolant and obtains enthalpy in the third heat exchanger 16 (such as Figure 8 as indicated by the arrow 160 in the figure), so that the low-temperature coolant flows out of the first coolant outlet of the third heat exchanger 16, and the low-temperature coolant can absorb the heat of the battery pack to achieve the cooling of the battery pack. The gas-liquid two-phase mixed refrigerant flowing out of the outlet of the indoor evaporator 3 and the gas-liquid two-phase mixed refrigerant flowing out of the refrigerant outlet of the third heat exchanger 16 converge and then flow into the second heat exchanger 6, and absorb heat in the second heat exchanger 6 to obtain the enthalpy lost by the refrigerant flowing out of the liquid outlet of the second liquid storage and dryer 12 in the second heat exchanger 6 (such as Figure 8 as indicated by the arrow 600b in the figure), so that the gas-liquid two-phase refrigerant flowing out of the refrigerant outlet of the third heat exchanger 16 is transformed into a gaseous refrigerant, that is, the refrigerant flowing out of the second refrigerant outlet of the second heat exchanger 6 is located in the superheated steam region, and the pure gaseous refrigerant flowing out of the second refrigerant outlet of the second heat exchanger 6 finally returns to the compressor 1.

[0072] Mode 4: Heat pump heating mode. In this mode, as Figure 9 shown, the first cut-off valve 18 is closed, the second cut-off valve 19 is opened, the third cut-off valve 20 is closed, the first expansion valve 7 is opened, the second expansion valve 8 is closed, and the third expansion valve 17 is closed. As Figure 9 and Figure 10 shown, the refrigerant entering the compressor 1 is a gaseous refrigerant, and the compressor 1 compresses the gaseous refrigerant so that the outlet of the compressor 1 discharges a high-temperature and high-pressure gaseous refrigerant (such as Figure 10 as indicated by the arrow 100 in the figure), and the high-temperature and high-pressure gaseous refrigerant flows into the indoor condenser 2 and releases heat and loses enthalpy to the passenger compartment in the indoor condenser 2 (such asFigure 10 as indicated by the arrow 200 in [FIGURE], to increase the temperature of the passenger compartment and achieve heating of the passenger compartment. The gas-liquid two-phase mixed refrigerant after heat release flowing out from the outlet of the indoor condenser 2 flows into the first liquid storage and dryer 11. The liquid refrigerant (such as Figure 10 the point 110 in [FIGURE]) flows out from the second liquid storage and dryer 12 and flows into the first heat exchanger 5, and releases heat and loses enthalpy in the first heat exchanger 5 (such as Figure 10 as indicated by the arrow 500a in [FIGURE]). The liquid refrigerant flows out from the first refrigerant outlet of the first heat exchanger 5. This liquid refrigerant undergoes an isenthalpic pressure drop in the first expansion valve 7 and crosses the saturated liquid line (such as Figure 10 as indicated by the arrow 700 in [FIGURE]). The low-temperature and low-pressure gas-liquid two-phase mixed refrigerant flowing out from the outlet of the first expansion valve 7 absorbs heat from the outside atmosphere and gains enthalpy in the outdoor heat exchanger 4 (such as Figure 10 as indicated by the arrow 400 in [FIGURE]). The gas-liquid two-phase refrigerant flowing out from the outlet of the outdoor heat exchanger 4 continues to absorb heat in the first heat exchanger 5 and gains the enthalpy lost by the refrigerant flowing from the first liquid storage and dryer 11 into the first heat exchanger 5 (such as Figure 10 as indicated by the arrow 500b in [FIGURE]), so that the gas-liquid two-phase refrigerant flowing out from the outlet of the outdoor heat exchanger 4 is transformed into a gaseous refrigerant, that is, the refrigerant flowing out from the second refrigerant outlet of the first heat exchanger 5 is in the superheated steam region. This gaseous refrigerant returns to the compressor 1 after passing through the second heat exchanger 6. Here, no refrigerant flows into the first refrigerant inlet of the second heat exchanger 6, that is, no heat exchange occurs in the second heat exchanger 6, and the second heat exchanger 6 is used as a flow passage.

[0073] Mode Five: Waste Heat Recovery Mode. In this mode, as Figure 11 shown, the first shut-off valve 18 is closed, the second shut-off valve 19 is closed, the third shut-off valve 20 is opened, the first expansion valve 7 is closed, the second expansion valve 8 is closed, and the third expansion valve 17 is opened. As Figure 11 and Figure 12 shown, the refrigerant entering the compressor 1 is a gaseous refrigerant. The compressor 1 compresses the gaseous refrigerant so that a high-temperature and high-pressure gaseous refrigerant is discharged from the outlet of the compressor 1 (such as Figure 12 as indicated by the arrow 100 in [FIGURE]). This high-temperature and high-pressure gaseous refrigerant flows into the indoor condenser 2 and releases heat and loses enthalpy to the passenger compartment in the indoor condenser 2 (such as Figure 12 as indicated by the arrow 200 in [FIGURE]) to increase the temperature of the passenger compartment and achieve heating of the passenger compartment. The gas-liquid two-phase mixed refrigerant after heat release flowing out from the outlet of the indoor condenser 2 flows into the first liquid storage and dryer 11. The liquid refrigerant (such as Figure 12 the point 110 in [FIGURE]) flows out from the second liquid storage and dryer 12. This liquid refrigerant undergoes an isenthalpic pressure drop in the third expansion valve 17 and crosses the saturated liquid line (such as Figure 12As shown by the arrow 170 in [figure], the outlet of the third expansion valve 17 discharges the low-temperature and low-pressure gas-liquid two-phase refrigerant. This low-temperature and low-pressure gas-liquid two-phase refrigerant absorbs the heat of the high-temperature coolant that has absorbed heat from the electronic device in the third heat exchanger 16 and obtains enthalpy (as Figure 12 shown by the arrow 160 in [figure]), thus realizing the recovery of the heat of the electronic device into the heat pump air-conditioning system. The refrigerant flowing out from the refrigerant outlet of the third heat exchanger 16 returns to the compressor 1 via the second heat exchanger 6. Here, no refrigerant flows into the first refrigerant inlet of the second heat exchanger 6, that is, the refrigerant flowing out from the refrigerant outlet of the third heat exchanger 16 does not exchange heat in the second heat exchanger 6.

[0074] Mode six: Heat pump with waste heat recovery mode. In this mode, as Figure 13 shown, the first cut-off valve 18 is closed, the second cut-off valve 19 is opened, the third cut-off valve 20 is opened, the first expansion valve 7 is opened, the second expansion valve 8 is closed, and the third expansion valve 17 is opened. As Figure 13 and Figure 14 shown, the refrigerant entering the compressor 1 is gaseous refrigerant. The compressor 1 compresses the gaseous refrigerant so that the outlet of the compressor 1 discharges high-temperature and high-pressure gaseous refrigerant (as Figure 14 shown by the arrow 100 in [figure]). This high-temperature and high-pressure gaseous refrigerant flows into the indoor condenser 2 and releases heat and loses enthalpy in the indoor condenser 2 (as Figure 14 shown by the arrow 200 in [figure]) to increase the temperature of the passenger compartment and realize the heating of the passenger compartment. The heat-released gas-liquid two-phase mixed refrigerant flowing out from the outlet of the indoor condenser 2 flows into the first liquid storage and dryer 11. The liquid outlet of the first liquid storage and dryer 11 discharges liquid refrigerant (as Figure 14 the point 110 in [figure]). This liquid refrigerant is divided into two streams. One stream undergoes an isenthalpic pressure drop in the third expansion valve 17 and crosses the saturated liquid line (as Figure 14 shown by the arrow 170 in [figure]). The outlet of the third expansion valve 17 discharges the low-temperature and low-pressure gas-liquid two-phase refrigerant. This low-temperature and low-pressure gas-liquid two-phase refrigerant absorbs the heat of the high-temperature coolant that has absorbed heat from the electronic device in the third heat exchanger 16 and obtains enthalpy (as Figure 14 shown by the arrow 160 in [figure]), thus realizing the recovery of the heat of the electronic device into the heat pump air-conditioning system; the other stream flows into the first heat exchanger 5 and releases heat and loses enthalpy in the first heat exchanger 5 (as Figure 14 shown by the arrow 500a in [figure]). The first refrigerant outlet of the first heat exchanger 5 discharges liquid refrigerant. This liquid refrigerant undergoes an isenthalpic pressure drop in the first expansion valve 7 and crosses the saturated liquid line (as Figure 14 shown by the arrow 700 in [figure]). The outlet of the first expansion valve 7 discharges the low-temperature and low-pressure gas-liquid two-phase mixed refrigerant. This low-temperature and low-pressure gas-liquid two-phase mixed refrigerant absorbs the heat of the outside atmosphere in the outdoor heat exchanger 4 and obtains enthalpy (as Figure 14as indicated by the arrow 400 in [reference], the gas-liquid two-phase refrigerant flowing out of the outlet of the outdoor heat exchanger 4 continues to absorb heat in the first heat exchanger 5, obtaining the enthalpy lost by the refrigerant flowing from the first liquid storage and dryer 11 into the first heat exchanger 5 (as Figure 14 as indicated by the arrow 500b in [reference]. The refrigerant flowing out of the second refrigerant outlet of the first heat exchanger 5 and the refrigerant flowing out of the refrigerant outlet of the third heat exchanger 16 converge and then return to the compressor 1 via the second heat exchanger 6. Here, no refrigerant flows into the first refrigerant inlet of the second heat exchanger 6, that is, the refrigerant flowing out of the second refrigerant outlet of the first heat exchanger 5 and the refrigerant flowing out of the refrigerant outlet of the third heat exchanger 16 do not exchange heat in the second heat exchanger 6.

[0075] Mode Seven: The first dehumidification mode. In this mode, as Figure 15 shown, the first shut-off valve 18 is closed, the second shut-off valve 19 is opened, the third shut-off valve 20 is opened, the first expansion valve 7 is opened, the second expansion valve 8 is opened, and the third expansion valve 17 is closed. As Figure 15 and Figure 16 shown, the refrigerant entering the compressor 1 is gaseous refrigerant, and the compressor 1 compresses the gaseous refrigerant so that the outlet of the compressor 1 discharges high-temperature and high-pressure gaseous refrigerant (as Figure 16 indicated by the arrow 100 in [reference]), and this high-temperature and high-pressure gaseous refrigerant flows into the indoor condenser 2 and releases heat and loses enthalpy in the indoor condenser 2 (as Figure 16 indicated by the arrow 200 in [reference]). The heat-released gas-liquid two-phase mixed refrigerant flowing out of the outlet of the indoor condenser 2 flows into the first liquid storage and dryer 11, and the first liquid storage and dryer 11 discharges liquid refrigerant (as Figure 16 the point 110 in [reference]), and this liquid refrigerant is divided into two streams. One stream undergoes an isenthalpic pressure drop in the second expansion valve 8 and crosses the saturated liquid line (as Figure 16 indicated by the arrow 800 in [reference]), and the low-temperature and low-pressure gas-liquid two-phase refrigerant flowing out of the outlet of the second expansion valve 8 absorbs heat from the passenger compartment and obtains enthalpy in the indoor evaporator 3 (as Figure 16 indicated by the arrow 300 in [reference]). The relatively warm and humid air in the passenger compartment encounters the relatively cold indoor evaporator 3, and the small liquid droplets in the humid air condense on the surface of the indoor evaporator 3 to form condensed water, thereby achieving dehumidification of the passenger compartment; the other stream flowing out of the liquid outlet of the first liquid storage and dryer 11 flows into the first heat exchanger 5 and releases heat and loses enthalpy in the first heat exchanger 5 (as Figure 16 indicated by the arrow 500a in [reference]), and the liquid refrigerant flowing out of the first refrigerant outlet of the first heat exchanger 5 undergoes an isenthalpic pressure drop in the first expansion valve 7 and crosses the saturated liquid line (as Figure 16As shown by the arrow 700 in [description], the outlet of the first expansion valve 7 discharges a refrigerant in a low-temperature and low-pressure gas-liquid two-phase mixed state. This low-temperature and low-pressure gas-liquid two-phase mixed refrigerant absorbs heat from the external atmosphere in the outdoor heat exchanger 4 and obtains enthalpy (such as Figure 16 As shown by the arrow 400 in [description], the gas-liquid two-phase refrigerant flowing out of the outlet of the outdoor heat exchanger 4 continues to absorb heat in the first heat exchanger 5 and obtains the enthalpy lost by the refrigerant flowing from the first liquid receiver / dryer 11 into the first heat exchanger 5 (such as Figure 16 As shown by the arrow 500b in [description]). The refrigerant flowing out of the second refrigerant outlet of the first heat exchanger 5 converges with the refrigerant flowing out of the refrigerant outlet of the indoor evaporator 3 and then returns to the compressor 1 via the second heat exchanger 6. Here, no refrigerant flows into the first refrigerant inlet of the second heat exchanger 6, that is, the refrigerant flowing out of the second refrigerant outlet of the first heat exchanger 5 and the refrigerant flowing out of the outlet of the indoor evaporator 3 do not exchange heat in the second heat exchanger 6.

[0076] Mode Eight: Second Dehumidification Mode. In this mode, as Figure 17 shown, the first shut-off valve 18 is closed, the second shut-off valve 19 is closed, the third shut-off valve 20 is opened, the first expansion valve 7 is closed, the second expansion valve 8 is closed, and the third expansion valve 17 is opened. As Figure 17 and Figure 18 shown, the refrigerant entering the compressor 1 is gaseous refrigerant, and the compressor 1 compresses the gaseous refrigerant so that the outlet of the compressor 1 discharges high-temperature and high-pressure gaseous refrigerant (such as Figure 18 the arrow 100 in [description]), and this high-temperature and high-pressure gaseous refrigerant flows into the indoor condenser 2 and releases enthalpy by heating the passenger compartment in the indoor condenser 2 (such as Figure 18 the arrow 200 in [description]). The heat-released gas-liquid two-phase mixed refrigerant flowing out of the outlet of the indoor condenser 2 flows into the first liquid receiver / dryer 11, and the liquid outlet of the first liquid receiver / dryer 11 discharges liquid refrigerant (such as Figure 18 the point 110 in [description]), and this liquid refrigerant undergoes an isenthalpic pressure drop in the second expansion valve 8 and crosses the saturated liquid line (such as Figure 18 the arrow 800 in [description]). The outlet of the second expansion valve 8 discharges a low-temperature and low-pressure gas-liquid two-phase refrigerant, and this low-temperature and low-pressure gas-liquid two-phase refrigerant absorbs heat from the passenger compartment in the indoor evaporator 3 and obtains enthalpy (such as Figure 18 the arrow 300 in [description]). The relatively warm and humid air in the passenger compartment encounters the relatively cold indoor evaporator 3, and the small liquid droplets in the humid air condense on the surface of the indoor evaporator 3 to form condensed water, thereby achieving dehumidification of the passenger compartment. The refrigerant flowing out of the outlet of the indoor evaporator 3 returns to the compressor 1 via the second heat exchanger 6. Here, no refrigerant flows into the first refrigerant inlet of the second heat exchanger 6, that is, the refrigerant flowing out of the outlet of the indoor evaporator 3 does not exchange heat in the second heat exchanger 6.

[0077] It should be noted that the above modes are the main working modes provided by the present disclosure for the vehicle thermal management system. Working modes not mentioned in the present disclosure but achievable through the vehicle thermal management system provided by the present disclosure also fall within the protection scope of the present disclosure.

[0078] According to another aspect of the present disclosure, there is also provided a vehicle including the above heat pump air conditioning system.

[0079] The preferred embodiments of the present disclosure have been described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0080] In addition, it should be noted that, among the various specific technical features described in the above specific embodiments, they can be combined in any suitable manner without conflict. To avoid unnecessary repetition, the present disclosure will not separately describe various possible combination methods.

[0081] In addition, any combination can be made between various different embodiments of the present disclosure, as long as it does not violate the idea of the present disclosure, it should also be regarded as the content disclosed by the present disclosure.

Claims

1. A heat pump air conditioning system, characterized in that, It includes a compressor (1), an indoor condenser (2), an indoor evaporator (3), an outdoor heat exchanger (4), a first heat exchanger (5), a second heat exchanger (6), a first expansion valve (7), a second expansion valve (8), a first flow path (9) that selectively conducts or cuts off, and a second flow path (10) that selectively conducts or cuts off. The outlet of the compressor (1) is connected to the inlet of the indoor condenser (2), and is connected to the inlet of the outdoor heat exchanger (4) via the first flow path (9). The outlet of the indoor condenser (2) is connected to the first refrigerant inlet of the first heat exchanger (5). The first refrigerant outlet of the first heat exchanger (5) is connected to the inlet of the outdoor heat exchanger (4) via the first expansion valve (7). The outlet of the outdoor heat exchanger (4) is connected to the first refrigerant inlet of the second heat exchanger (6), and is connected to the second refrigerant inlet of the first heat exchanger (5) via the second flow path (10). The first refrigerant outlet of the second heat exchanger (6) is connected to the inlet of the indoor evaporator (3) via the second expansion valve (8). The outlet of the indoor evaporator (3) and the second refrigerant outlet of the first heat exchanger (5) are both connected to the second refrigerant inlet of the second heat exchanger (6). The second refrigerant outlet of the second heat exchanger (6) is connected to the inlet of the compressor (1). The heat pump air-conditioning system further includes a first liquid storage and dryer (11) and a second liquid storage and dryer (12). The outlet of the indoor condenser (2) is connected to the inlet of the first liquid storage and dryer (11). The liquid outlet of the first liquid storage and dryer (11) is connected to the first refrigerant inlet of the first heat exchanger (5). The outlet of the outdoor heat exchanger (4) is connected to the inlet of the second liquid storage and dryer (12). The liquid outlet of the second liquid storage and dryer (12) is connected to the first refrigerant inlet of the second heat exchanger (6). A first stop valve (18) is provided on the first flow path (9), and a second stop valve (19) is provided on the second flow path (10).

2. The heat pump air conditioning system according to claim 1, wherein, The heat pump air-conditioning system further includes a subcooler (13) located downstream of the second liquid storage and dryer (12). The liquid outlet of the second liquid storage and dryer (12) is connected to the first refrigerant inlet of the second heat exchanger (6) via the subcooler (13).

3. The heat pump air conditioning system according to claim 1 or 2, characterized in that, The heat pump air-conditioning system further includes a third flow path (14) that selectively conducts or cuts off. The liquid outlet of the first liquid storage and dryer (11) is also connected to the inlet of the second expansion valve (8) via the third flow path (14).

4. The heat pump air conditioning system according to claim 3, wherein, The heat pump air conditioning system further includes a third heat exchanger (16) and a third expansion valve (17). The first refrigerant outlet of the second heat exchanger (6) is also connected to the refrigerant inlet of the third heat exchanger (16) via the third expansion valve (17). The refrigerant outlet of the third heat exchanger (16) is connected to the second refrigerant inlet of the second heat exchanger (6). The first coolant outlet of the third heat exchanger (16) is used to connect to the inlet of the vehicle's battery pack, and the first coolant inlet of the third heat exchanger (16) is used to connect to the outlet of the battery pack.

5. The heat pump air conditioning system according to claim 4, characterized in that, The liquid outlet of the first liquid storage and dryer (11) is also connected to the inlet of the third expansion valve (17) via the third flow path (14). The second coolant outlet of the third heat exchanger (16) is used to connect to the inlet of the vehicle's electronic devices, and the second coolant inlet of the third heat exchanger (16) is used to connect to the outlet of the electronic devices.

6. The heat pump air-conditioning system according to claim 5, characterized in that, The heat pump air conditioning system further includes a check valve (15). The first refrigerant outlet of the second heat exchanger (6) is connected to the inlet of the second expansion valve (8) and the inlet of the third expansion valve (17) via the check valve (15).

7. The heat pump air conditioning system according to claim 5, characterized in that, The electronic devices include at least one of a motor, a charger, a motor controller, and a DC-DC converter.

8. A vehicle, characterized in that, It includes the heat pump air conditioning system according to any one of claims 1-7.

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