Hydrogen energy automobile self-recovery heat pump system and heat management method

Abstract

The application provides a hydrogen energy automobile self-recovery heat pump system, and relates to the field of vehicle air conditioners. The hydrogen energy automobile self-recovery heat pump system comprises a gas-liquid separator, a compressor, an indoor heat exchanger, a non-azeotropic working medium gas-liquid separator, a six-way heat exchanger and an outdoor heat exchanger. The suction port of the compressor is communicated with the gas-liquid separator. The exhaust port of the compressor is communicated with the indoor heat exchanger through a heating electromagnetic valve. The indoor heat exchanger is communicated with the non-azeotropic working medium gas-liquid separator through the six-way heat exchanger and a supercooling electromagnetic valve. The non-azeotropic working medium gas-liquid separator is communicated with the outdoor heat exchanger through the six-way heat exchanger and a heating electronic expansion valve. The non-azeotropic working medium gas-liquid separator is communicated with the gas-liquid separator through a high-boiling-point working medium electronic expansion valve and the six-way heat exchanger. The outdoor heat exchanger is communicated with the air supplementing port and the gas-liquid separator of the compressor through a gas supplementing and enthalpy increasing electromagnetic valve and a gas returning electromagnetic valve, respectively. The application further provides a heat management method, which can absorb heat from air in a low-temperature environment of-30 DEG C for heating.

Description

Technical Field

[0001] This invention relates to the field of automotive air conditioning, and more particularly to a self-cascading heat pump system and thermal management method for hydrogen fuel cell vehicles. Background Technology

[0002] Currently, air-source heat pump systems in the automotive field primarily utilize single-stage compression heat pump systems with medium-temperature refrigerants. However, in low-temperature environments, due to the relatively high boiling point of medium-temperature refrigerants, it is difficult for the refrigerant in the evaporator to maintain a sufficient temperature difference with the ambient air for heat absorption. In extreme cold weather, conventional automotive heat pump systems may even fail to start properly. If low-temperature refrigerants are directly used instead of medium-temperature refrigerants, the low condensation temperature below the critical pressure will result in reduced system heat dissipation. To increase the high-pressure side refrigerant temperature, the refrigerant may even need to be compressed above the critical pressure. Therefore, high-compression-ratio transcritical compressors are required for low-temperature heating. Summary of the Invention

[0003] The present invention aims to solve the technical problem that existing air source heat pump systems are unable to absorb heat from low-temperature ambient air for heating.

[0004] This invention proposes a self-cascaded heat pump system for hydrogen fuel cell vehicles, comprising a gas-liquid separator, a compressor, an indoor heat exchanger, a non-azeotropic working fluid gas-liquid separator, a six-way heat exchanger, and an outdoor heat exchanger.

[0005] The compressor's suction port is connected to the gas outlet of the gas-liquid separator; the compressor's discharge port is connected to the first interface of the indoor heat exchanger via a heating solenoid valve; the second interface of the indoor heat exchanger is connected to the first interface of the non-azeotropic working fluid gas-liquid separator via a six-way heat exchanger and a subcooling solenoid valve; the second interface of the non-azeotropic working fluid gas-liquid separator is connected to the inlet of the outdoor heat exchanger via a six-way heat exchanger and a heating electronic expansion valve; the third interface of the non-azeotropic working fluid gas-liquid separator is connected to the inlet of the gas-liquid separator via a high-boiling-point working fluid electronic expansion valve and a six-way heat exchanger; the non-azeotropic working fluid gas-liquid separator is used to separate the non-azeotropic mixed refrigerant into a liquid medium-temperature refrigerant and a gaseous low-temperature refrigerant; the outlet of the outdoor heat exchanger is connected to the compressor's gas inlet and the gas-liquid separator's inlet via a gas injection enthalpy-increasing solenoid valve and a gas return solenoid valve, respectively.

[0006] Furthermore, the second port of the indoor heat exchanger is connected to the first port of the non-azeotropic working fluid gas-liquid separator in sequence through the six-way heat exchanger and the subcooling solenoid valve;

[0007] And / or, the second port of the non-azeotropic working fluid gas-liquid separator is connected to the inlet of the outdoor heat exchanger in sequence through the six-way heat exchanger and the heating electronic expansion valve;

[0008] And / or, the third port of the non-azeotropic working fluid gas-liquid separator is connected to the inlet of the gas-liquid separator in sequence through the high-boiling-point working fluid electronic expansion valve and the six-way heat exchanger.

[0009] Furthermore, the gas replenishment and enthalpy-increasing solenoid valve and the gas return solenoid valve are replaced with a first proportional three-way valve; the outlet of the outdoor heat exchanger is connected to the gas replenishment port of the compressor and the inlet of the gas-liquid separator through the first proportional three-way valve.

[0010] Furthermore, the hydrogen fuel cell vehicle self-cascade heat pump system also includes a first refrigeration solenoid valve and a second refrigeration solenoid valve. The outlet of the compressor is connected to the inlet of the outdoor heat exchanger through the first refrigeration solenoid valve. The second refrigeration solenoid valve is connected in parallel with the heating electronic expansion valve and the outdoor heat exchanger.

[0011] And / or, it also includes a refrigeration electronic expansion valve and a third refrigeration solenoid valve; the second interface of the indoor heat exchanger is also connected to the first interface of the non-azeotropic working fluid gas-liquid separator through the refrigeration electronic expansion valve; the first interface of the indoor heat exchanger is also connected to the inlet of the gas-liquid separator through the third refrigeration solenoid valve.

[0012] Furthermore, the first refrigeration solenoid valve and the heating solenoid valve are replaced with a second proportional three-way valve; the exhaust port of the compressor is connected to the first interface of the indoor heat exchanger and the inlet of the outdoor heat exchanger through the second proportional three-way valve.

[0013] Furthermore, the hydrogen fuel cell vehicle self-cascade heat pump system also includes an air conditioning unit housing and a blower; the blower and the indoor heat exchanger are disposed inside the air conditioning unit housing; the blower cooperates with the air conditioning unit housing to introduce the gas after heat exchange by the indoor heat exchanger into the room;

[0014] And / or, it also includes a cooling axial flow fan, which is provided corresponding to the outdoor heat exchanger.

[0015] This invention also proposes a thermal management method applied to the aforementioned hydrogen fuel cell vehicle cascade heat pump system, comprising the following steps:

[0016] Obtain the thermal management mode of the hydrogen fuel cell vehicle's self-cascaded heat pump system;

[0017] When the thermal management mode is heating mode, the ratio of gaseous low-temperature refrigerant from the outdoor heat exchanger to the gas-liquid separator and the compressor is adjusted to meet the heating demand.

[0018] Furthermore, when the thermal management mode is the heating mode, the specific operation method of the hydrogen fuel cell vehicle self-cascade heat pump system is as follows:

[0019] The compressor compresses the non-azeotropic refrigerant gas mixture in the gas-liquid separator and outputs it, which flows through the indoor heat exchanger to cool it into a non-azeotropic refrigerant gas-liquid mixture and thus raise the temperature of the indoor air.

[0020] The non-azeotropic refrigerant gas-liquid mixture is cooled by the six-way heat exchanger and then enters the non-azeotropic working fluid gas-liquid separator, where it is separated into liquid medium-temperature refrigerant and gaseous low-temperature refrigerant. The liquid medium-temperature refrigerant is depressurized into a gas-liquid two-phase medium-temperature refrigerant by the high-boiling-point working fluid electronic expansion valve, and then becomes gaseous medium-temperature refrigerant after absorbing heat and heating up in the six-way heat exchanger, flowing into the gas-liquid separator. The gaseous low-temperature refrigerant is cooled by the six-way heat exchanger, flows through the heating electronic expansion valve to depressurize into a gas-liquid two-phase low-temperature refrigerant, and then absorbs heat from the ambient air by the outdoor heat exchanger, becoming gaseous low-temperature refrigerant. It then enters the compressor through the gas replenishment enthalpy-increasing solenoid valve and / or enters the gas-liquid separator through the return gas solenoid valve. The gaseous medium-temperature and gaseous low-temperature refrigerants in the gas-liquid separator are then re-inhaled into the compressor, thus completing the cycle.

[0021] Furthermore, when the thermal management mode is cooling mode, the operation method of the hydrogen fuel cell vehicle self-cascade heat pump system is as follows:

[0022] The compressor compresses the non-azeotropic refrigerant mixture in the gas-liquid separator and outputs it. After being cooled by the outdoor heat exchanger, it becomes a non-azeotropic refrigerant gas-liquid mixture and enters the non-azeotropic working fluid gas-liquid separator to obtain gaseous low-temperature refrigerant and liquid medium-temperature refrigerant. The gaseous low-temperature refrigerant is stored in the tank of the non-azeotropic working fluid gas-liquid separator. The liquid medium-temperature refrigerant is depressurized by the refrigeration electronic expansion valve and becomes a gas-liquid two-phase medium-temperature refrigerant. It flows through the indoor heat exchanger to cool the indoor air and becomes gaseous medium-temperature refrigerant. It is then drawn back into the compressor through the gas-liquid separator and completes the refrigeration cycle through the gaseous medium-temperature refrigerant.

[0023] Furthermore, when the thermal management mode is defrosting mode, the operation method of the hydrogen fuel cell vehicle self-cascade heat pump system is as follows:

[0024] The compressor compresses the non-azeotropic refrigerant mixture in the gas-liquid separator and outputs it. Part of the compressed non-azeotropic refrigerant mixture flows through the outdoor heat exchanger for defrosting and becomes a non-azeotropic refrigerant gas-liquid mixture, which then flows out. After being cooled by the six-way heat exchanger into a non-azeotropic refrigerant liquid mixture, it enters the non-azeotropic working fluid gas-liquid separator. The remaining compressed non-azeotropic refrigerant mixture flows through the indoor heat exchanger to heat the indoor air. After being cooled, it becomes a non-azeotropic refrigerant gas-liquid mixture, which then flows out. After being cooled by the six-way heat exchanger, it enters the non-azeotropic working fluid gas-liquid separator. The non-azeotropic refrigerant liquid mixture in the non-azeotropic working fluid gas-liquid separator is depressurized by the high-boiling-point working fluid electronic expansion valve, becomes a non-azeotropic refrigerant gas-liquid mixture, absorbs heat through the six-way heat exchanger, becomes a non-azeotropic refrigerant gas mixture, flows back into the gas-liquid separator, and is then drawn back into the compressor, thus completing the cycle.

[0025] The beneficial effects of the technical solution provided by the embodiments of the present invention are as follows: The hydrogen fuel cell vehicle self-cascade heat pump system in the embodiments of the present invention compresses the non-azeotropic mixed refrigerant gas in the gas-liquid separator through a compressor and outputs it. This gas then flows through the indoor heat exchanger to cool into a non-azeotropic mixed refrigerant gas-liquid mixture, thereby raising the temperature of the indoor air. The non-azeotropic mixed refrigerant gas-liquid mixture is cooled by a six-way heat exchanger and then enters the non-azeotropic working fluid gas-liquid separator, where it is separated into a liquid medium-temperature refrigerant and a gaseous low-temperature refrigerant. The liquid medium-temperature refrigerant is depressurized by a high-boiling-point working fluid electronic expansion valve into a gas-liquid two-phase medium-temperature refrigerant, and after absorbing heat and heating in the six-way heat exchanger, it becomes a gaseous medium-temperature refrigerant and flows into the gas-liquid separator. The gaseous low-temperature refrigerant is cooled by the six-way heat exchanger and then depressurized by a heating electronic expansion valve into a gas-liquid two-phase low-temperature refrigerant. It then flows through the outdoor heat exchanger to absorb heat from the ambient air and becomes a gaseous low-temperature refrigerant. The gas-increasing enthalpy solenoid valve enters the compressor and / or the return gas solenoid valve enters the gas-liquid separator (or the proportion of gaseous low-temperature refrigerant entering the compressor and the gas-liquid separator is adjusted by the first proportional three-way valve); the gaseous medium-temperature refrigerant and gaseous low-temperature refrigerant in the gas-liquid separator are re-drawn into the compressor, thus circulating; by using the non-azeotropic mixed refrigerant as the refrigerant of the hydrogen-powered vehicle self-cascade heat pump system, heat is absorbed from the -30℃ low-temperature ambient air for heating; in addition, the opening of the return gas solenoid valve can be adjusted according to the temperature of the ambient air to control the temperature difference between the inside and outside of the outdoor heat exchanger, so that the surface of the outdoor heat exchanger is not prone to frequent frost formation, while ensuring that the evaporation pressure of the gas replenishment circuit in the compressor is not high, the gaseous medium-temperature refrigerant and gaseous low-temperature refrigerant in the gas-liquid separator are drawn into the compressor through the suction port and compressed to meet the high-efficiency and stable heating requirements under different ambient temperatures. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a hydrogen fuel cell vehicle self-cascade heat pump system in one embodiment of the present invention;

[0027] Figure 2 for Figure 1 A schematic diagram illustrating the working principle of the self-cascaded heat pump system in a hydrogen-powered vehicle when it is in heating mode.

[0028] Figure 3 for Figure 1 A schematic diagram illustrating the working principle of the self-cascaded heat pump system in a hydrogen-powered vehicle when it is in cooling mode.

[0029] Figure 4 for Figure 1 A schematic diagram illustrating the working principle of the self-cascade heat pump system in a hydrogen-powered vehicle during defrosting mode.

[0030] Figure 5 This is a property diagram of a non-azeotropic refrigerant mixture and a conventionally used refrigerant in one embodiment of the present invention;

[0031] Figure 6 This is a pressure-enthalpy diagram of a non-azeotropic mixed refrigerant cycle under the gas-injection and enthalpy-increasing heating mode in a certain embodiment of the present invention;

[0032] Figure 7 This is a pressure-enthalpy diagram of a non-azeotropic mixed refrigerant cycle under a non-gas-supplemented enthalpy-increasing heating mode in a certain embodiment of the present invention;

[0033] Figure 8 This is a pressure-enthalpy diagram of a non-azeotropic mixed refrigerant cycle in a refrigeration mode according to a certain embodiment of the present invention;

[0034] Figure 9 This is a pressure-enthalpy diagram of a non-azeotropic mixed refrigerant cycle in defrosting mode according to a certain embodiment of the present invention;

[0035] The components include: 1. Compressor; 2. Outdoor heat exchanger; 3. Refrigeration electronic expansion valve; 4. Indoor heat exchanger; 5. Gas-liquid separator; 6. First refrigeration solenoid valve; 7. Second refrigeration solenoid valve; 8. Heating electronic expansion valve; 9. Heating solenoid valve; 10. Return gas solenoid valve; 11. Air supply blower; 12. Cooling axial flow fan; 13. Air conditioning unit housing; 14. High-boiling-point working fluid electronic expansion valve; 15. Six-way heat exchanger; 16. Non-azeotropic working fluid gas-liquid separator; 17. Gas replenishment and enthalpy increase solenoid valve; 18. Subcooling solenoid valve; and 19. Third refrigeration solenoid valve. Detailed Implementation

[0036] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0037] Please refer to Figure 1 The present invention provides a hydrogen fuel cell vehicle self-cascade heat pump system, including a gas-liquid separator 5, a compressor 1, an indoor heat exchanger 4, a non-azeotropic working fluid gas-liquid separator 16, a six-way heat exchanger 15 and an outdoor heat exchanger 2.

[0038] The suction port of compressor 1 is connected to the gas outlet of gas-liquid separator 5; the discharge port of compressor 1 is connected to the first interface of indoor heat exchanger 4 through heating solenoid valve 9; the second interface of indoor heat exchanger 4 is connected to the first interface of non-azeotropic working fluid gas-liquid separator 16 through six-way heat exchanger 15 and subcooling solenoid valve 18; the second interface of non-azeotropic working fluid gas-liquid separator 16 is connected to the inlet of outdoor heat exchanger 2 through six-way heat exchanger 15 and heating electronic expansion valve 8; the third interface of non-azeotropic working fluid gas-liquid separator 16 is connected to the inlet of gas-liquid separator 5 through high-boiling-point working fluid electronic expansion valve 14 and six-way heat exchanger 15; non-azeotropic working fluid gas-liquid separator 16 is used to separate non-azeotropic mixed refrigerant into liquid medium-temperature refrigerant and gaseous low-temperature refrigerant; the outlet of outdoor heat exchanger 2 is connected to the gas supply port of compressor 1 and the inlet of gas-liquid separator 5 through gas supply enthalpy increase solenoid valve 17 and return gas solenoid valve 10, respectively.

[0039] It should be noted that the components of the hydrogen fuel cell vehicle self-cascade heat pump system in this embodiment are all existing technologies, so their specific structures will not be described in detail here; the improvement of this invention involves the combination of the above-mentioned components.

[0040] Specifically, in this embodiment, the second port of the indoor heat exchanger 4 is connected to the first port of the non-azeotropic working fluid gas-liquid separator 16 via a six-way heat exchanger 15 and a subcooling solenoid valve 18. By placing the subcooling solenoid valve 18 between the first port of the non-azeotropic working fluid gas-liquid separator 16 and the six-way heat exchanger 15, the liquid in the non-azeotropic working fluid gas-liquid separator 16 can be effectively prevented from flowing back into the six-way heat exchanger 15, generating bubbles, and causing the liquid in the non-azeotropic working fluid gas-liquid separator 16 to boil and churn. In addition, the refrigeration electronic expansion valve 3 and the high-boiling-point working fluid electronic expansion valve 14 can also prevent the liquid in the non-azeotropic working fluid gas-liquid separator 16 from flowing back into the six-way heat exchanger 15, generating bubbles, and causing the liquid in the non-azeotropic working fluid gas-liquid separator 16 to boil and churn. By setting the subcooling solenoid valve 18, the refrigeration electronic expansion valve 3, and the high-boiling-point working fluid electronic expansion valve 14, insufficient gas-liquid separation in the non-azeotropic working fluid gas-liquid separator 16 can be avoided.

[0041] The second port of the non-azeotropic working fluid gas-liquid separator 16 is connected to the inlet of the outdoor heat exchanger 2 through the six-way heat exchanger 15 and the heating electronic expansion valve 8 in sequence. By setting the heating electronic expansion valve 8 between the six-way heat exchanger 15 and the second port of the non-azeotropic working fluid gas-liquid separator 16, the gaseous low-temperature refrigerant is cooled by the six-way heat exchanger 15 and then flows through the heating electronic expansion valve 8 to be depressurized into a gas-liquid two-phase low-temperature refrigerant.

[0042] The third port of the non-azeotropic working fluid gas-liquid separator 16 is connected to the inlet of the gas-liquid separator 5 via a high-boiling-point working fluid electronic expansion valve 14 and a six-way heat exchanger. By placing the high-boiling-point working fluid electronic expansion valve 14 between the third port of the non-azeotropic working fluid gas-liquid separator 16 and the six-way heat exchanger 15, the liquid medium-temperature refrigerant can be depressurized by the high-boiling-point working fluid electronic expansion valve 14 into a gas-liquid two-phase medium-temperature refrigerant, which serves as the cooling medium of the six-way heat exchanger 15. After absorbing heat and rising in temperature through the six-way heat exchanger 15, it becomes a gaseous medium-temperature refrigerant and flows into the gas-liquid separator 5.

[0043] As a variation of this embodiment, the gas replenishment and enthalpy-increasing solenoid valve 17 and the gas return solenoid valve 10 can also be replaced with a first proportional three-way valve; the outlet of the outdoor heat exchanger 2 is connected to the gas replenishment port of the compressor 1 and the inlet of the gas-liquid separator 5 through the first proportional three-way valve.

[0044] Specifically, in order to enable the hydrogen fuel cell vehicle self-cascade heat pump system to simultaneously provide heating, cooling, and defrosting functions, the hydrogen fuel cell vehicle self-cascade heat pump system further includes a first refrigeration solenoid valve 6, a refrigeration electronic expansion valve 3, a second refrigeration solenoid valve 7, and a third refrigeration solenoid valve 19; the outlet of the compressor 1 is connected to the inlet of the outdoor heat exchanger 2 through the first refrigeration solenoid valve 6; the second interface of the indoor heat exchanger 4 is also connected to the first interface of the non-azeotropic working fluid gas-liquid separator 16 through the refrigeration electronic expansion valve 3; the first interface of the indoor heat exchanger 4 is also connected to the inlet of the gas-liquid separator 5 through the third refrigeration solenoid valve 19; the second refrigeration solenoid valve 7 is connected in parallel with the heating electronic expansion valve 8 and the outdoor heat exchanger 2.

[0045] As a variation of this embodiment, the first refrigeration solenoid valve 6 and the heating solenoid valve 9 can also be replaced with a second proportional three-way valve; the exhaust port of the compressor 1 is connected to the first interface of the indoor heat exchanger 4 and the inlet of the outdoor heat exchanger 2 through the second proportional three-way valve.

[0046] refer to Figure 1 The hydrogen fuel cell vehicle self-cascade heat pump system also includes a cooling axial flow fan 12, which is used to deliver ambient air to the outdoor heat exchanger 2, thereby accelerating the heat exchange efficiency between the ambient air and the outdoor heat exchanger 2.

[0047] Specifically, the hydrogen fuel cell vehicle self-cascade heat pump system also includes an air conditioning housing 13 and an air blower 11; the air blower 11 and the indoor heat exchanger 4 are disposed inside the air conditioning housing 13; the air blower 11 cooperates with the air conditioning housing 13 to introduce the gas after heat exchange by the indoor heat exchanger 4 into the room.

[0048] The hydrogen fuel cell vehicle self-cascade heat pump system in this embodiment not only uses a gas-injection enthalpy-increasing compressor 1 to achieve quasi-two-stage compression and reduce the exhaust superheat temperature under high pressure ratio conditions, but also uses a non-azeotropic mixed refrigerant (containing a high-boiling-point medium-temperature refrigerant component and a low-boiling-point low-temperature refrigerant component) as the working fluid. Through a specially designed system loop, the performance of the self-cascade system it forms is closer to that of a true two-stage compression cascade system, but its system structure is simpler than the latter.

[0049] Meanwhile, considering the characteristics of vehicle cooling (including anti-frost) and heating (including defrosting), by rationally arranging the circulation loop and loop switching, it achieves temperature-segmented heating by switching between single and dual components of a non-azeotropic refrigerant mixture in high-temperature environments (25℃~50℃) and in environments with large temperature differences between medium and low temperatures (-40℃~20℃). In cooling mode, using a single working fluid component of a high-boiling-point medium-temperature refrigerant ensures that the heat exchanger surface does not frost frequently, while ensuring that the outdoor heat exchanger 2 can dissipate heat to the ambient air at a relatively high condensation temperature.

[0050] When in a low-temperature environment, such as when the temperature reaches -40℃, the medium-temperature refrigerant can no longer evaporate and absorb heat in the outdoor heat exchanger 2. A low-temperature refrigerant must be used to evaporate in the outdoor heat exchanger 2 and absorb heat from the low-temperature air. However, the low-boiling-point low-temperature refrigerant cannot directly transfer heat to the indoor air at a high condensing temperature. Therefore, it exchanges heat with the high-boiling-point medium-temperature refrigerant. The high-boiling-point medium-temperature refrigerant heats the indoor air in the indoor heat exchanger 4 by virtue of its high condensing temperature. Finally, the two are mixed and return to the compressor 1.

[0051] Similarly, when heating in ambient air around zero degrees Celsius, the system circuit is basically the same as the low-temperature heating circuit mentioned above. The only difference is that the low-boiling-point refrigerant circuit returns to compressor 1 via the gas injection and enthalpy-increasing circuit. At this time, the evaporation pressure of the low-boiling-point refrigerant is greater than that of the high-boiling-point refrigerant. This is to ensure that the surface of the outdoor heat exchanger 2 (used as an evaporator) does not frequently frost due to the large temperature difference with the ambient air, and to facilitate effective cooling of compressor 1 when it operates at a high pressure ratio in a relatively high-temperature environment. In addition, if the outdoor heat exchanger 2 (used as an evaporator) frosts during the heating process, it can be switched to a condenser for defrosting, while the indoor heat exchanger 4 continues to heat the indoor air. The superheat of the compressor suction is ensured by using the condenser-evaporator.

[0052] This invention also proposes a thermal management method applied to the aforementioned hydrogen fuel cell vehicle cascade heat pump system, comprising the following steps:

[0053] Obtain the thermal management mode of the hydrogen fuel cell vehicle's self-cascaded heat pump system;

[0054] When the thermal management mode is heating mode, the ratio of gaseous low-temperature refrigerant from the outdoor heat exchanger 2 to enter the gas-liquid separator 5 and compressor 1 is adjusted to meet the heating demand.

[0055] refer to Figure 2 When the thermal management mode is heating mode, the operation method of the hydrogen fuel cell vehicle self-cascade heat pump system is as follows:

[0056] The compressor 1 compresses the non-azeotropic refrigerant gas mixture in the gas-liquid separator 5 and outputs it. The gas mixture flows through the indoor heat exchanger 4 and is cooled into a non-azeotropic refrigerant gas-liquid mixture, thereby raising the temperature of the indoor air. During this process, the average temperature of the refrigerant is about 60 to 100°C.

[0057] The non-azeotropic refrigerant gas-liquid mixture is cooled by a six-way heat exchanger 15 and then enters a non-azeotropic working fluid gas-liquid separator 16, where it is separated into a liquid medium-temperature refrigerant and a gaseous low-temperature refrigerant. The liquid medium-temperature refrigerant is depressurized by a high-boiling-point working fluid electronic expansion valve 14 into a gas-liquid two-phase medium-temperature refrigerant, and then, after absorbing heat and heating in the six-way heat exchanger 15, becomes a gaseous medium-temperature refrigerant and flows into the gas-liquid separator 5. The gaseous low-temperature refrigerant is cooled by the six-way heat exchanger 15 and then flows through a heating electronic expansion valve 8 to depressurize into a gas-liquid two-phase low-temperature refrigerant. After absorbing heat from the ambient air in the outdoor heat exchanger 2, it becomes a gaseous low-temperature refrigerant, which then enters the compressor 1 via a gas injection enthalpy-increasing solenoid valve 17 and / or enters the gas-liquid separator 5 via a return gas solenoid valve 10. The gaseous medium-temperature and gaseous low-temperature refrigerants in the gas-liquid separator 5 are then re-inhaled into the compressor 1, thus completing the cycle.

[0058] In heating mode, the opening of the return air solenoid valve 10 can be adjusted according to the ambient air temperature to control the temperature difference between the inside and outside of the outdoor heat exchanger 2. This prevents frequent frost formation on the surface of the outdoor heat exchanger 2 while ensuring that the evaporation pressure of the gas supply circuit in the compressor 1 is not high. The gaseous medium-temperature refrigerant and gaseous low-temperature refrigerant in the gas-liquid separator 5 are drawn in through the suction port of the compressor 1 and compressed to meet the high-efficiency and stable heating requirements under different ambient temperatures. It can absorb heat from the -30℃ low-temperature ambient air for heating.

[0059] Figure 6This is the pressure-enthalpy diagram of the non-azeotropic mixed refrigerant cycle in the gas replenishment and enthalpy enhancement heating mode in this embodiment, that is, the pressure-enthalpy diagram of the hydrogen vehicle self-cascade heat pump system when gas replenishment and enthalpy enhancement are performed in the heating mode; at this time, the return gas solenoid valve 10 in the hydrogen vehicle self-cascade heat pump system is in the open state. Figure 7 This is the pressure-enthalpy diagram of the non-azeotropic refrigerant cycle in the non-gas-replenishing enthalpy-increasing heating mode in this embodiment, that is, the pressure-enthalpy diagram of the hydrogen vehicle self-cascade heat pump system when no gas-replenishing enthalpy-increasing is performed in the heating mode; at this time, the return gas solenoid valve 10 in the hydrogen vehicle self-cascade heat pump system is in the closed state. Figure 6 and Figure 7 In the middle, the non-azeotropic refrigerant mixture is shown; the lower left shows the medium-temperature refrigerant component; and the upper right shows the low-temperature refrigerant component.

[0060] For example, in this embodiment, the non-azeotropic refrigerant mixture is preferably a mixture of R23 and R134a; wherein R23 is a low-temperature refrigerant and R134a is a medium-temperature refrigerant. Figure 5 This is a property diagram of the non-azeotropic refrigerant mixture R23 / R134a and the conventionally used refrigerants R290 and R744 in this embodiment; where the horizontal axis represents pressure in MPa and the vertical axis represents boiling point in °C.

[0061] refer to Figure 3 When the thermal management mode is cooling mode, the operation method of the hydrogen fuel cell vehicle self-cascade heat pump system is as follows:

[0062] The compressor 1 compresses the non-azeotropic refrigerant mixture gas in the gas-liquid separator 5 and outputs it. After passing through the outdoor heat exchanger 2 for heat dissipation, it becomes a non-azeotropic refrigerant gas-liquid mixture (the average temperature of the refrigerant during the heat dissipation process in the outdoor heat exchanger 2 is about 40-60°C). It then enters the non-azeotropic working fluid gas-liquid separator 16 to obtain gaseous low-temperature refrigerant and liquid medium-temperature refrigerant. The gaseous low-temperature refrigerant is stored in the tank of the non-azeotropic working fluid gas-liquid separator 16. The liquid medium-temperature refrigerant is depressurized by the refrigeration electronic expansion valve 3 and becomes a gas-liquid two-phase medium-temperature refrigerant. It flows through the indoor heat exchanger 4 to cool the indoor air and becomes a gaseous medium-temperature refrigerant. It is then drawn back into the compressor 1 through the gas-liquid separator 5 and completes the refrigeration cycle through the gaseous medium-temperature refrigerant.

[0063] In cooling mode, except that the refrigerant circulating in the hydrogen fuel cell vehicle self-cascade heat pump system is a non-azeotropic mixture when it is first turned on, after one cycle, the low-temperature refrigerant in the non-azeotropic mixture is stored in the tank of the non-azeotropic working fluid gas-liquid separator 16. After that, only the medium-temperature refrigerant participates in the cooling cycle, so the system is no different from a regular vehicle single-cooling air conditioning system.

[0064] Figure 8This is a pressure-enthalpy diagram of the non-azeotropic refrigerant mixture cycle in the refrigeration mode of this embodiment; in the middle is the non-azeotropic refrigerant mixture, the lower left is the medium-temperature refrigerant component, and the upper right is the low-temperature refrigerant component.

[0065] refer to Figure 4 When the thermal management mode is defrosting mode, the operation method of the hydrogen fuel cell vehicle self-cascade heat pump system is as follows:

[0066] The compressor 1 compresses the non-azeotropic refrigerant mixture in the gas-liquid separator 5 and outputs it. Part of the compressed non-azeotropic refrigerant mixture flows through the outdoor heat exchanger 2 to release heat and defrost, becoming a non-azeotropic refrigerant gas-liquid mixture that flows out. After being cooled by the six-way heat exchanger 15 into a non-azeotropic refrigerant liquid mixture, it enters the non-azeotropic working fluid gas-liquid separator 16. The remaining compressed non-azeotropic refrigerant mixture flows through the indoor heat exchanger 4 to heat the indoor air. After being cooled, it becomes a non-azeotropic refrigerant gas-liquid mixture that flows out. After being cooled by the six-way heat exchanger 15, it enters the non-azeotropic working fluid gas-liquid separator 16. The non-azeotropic refrigerant liquid mixture in the non-azeotropic working fluid gas-liquid separator 16 is depressurized by the high-boiling-point working fluid refrigerant electronic expansion valve 3, becoming a non-azeotropic refrigerant gas-liquid mixture. After absorbing heat by the six-way heat exchanger 15, it becomes a non-azeotropic refrigerant gas mixture that flows into the gas-liquid separator 5 and is drawn back into the compressor 1, thus completing the cycle.

[0067] During the defrosting process of the non-azeotropic refrigerant mixture flowing through the outdoor heat exchanger 2, the average temperature of the refrigerant is approximately 60–100°C; at this time, the cooling axial flow fan 12 is not operating. During the process of the other compressed non-azeotropic refrigerant mixture flowing through the indoor heat exchanger 4 to heat the indoor air, the average temperature of the refrigerant is also approximately 60–100°C.

[0068] In defrost mode, the defrost temperature can reach about 100℃, which can quickly melt and remove the frost layer on the surface of the outdoor heat exchanger 2 (which is used as an evaporator at this time), while ensuring continuous and stable indoor heating without large fluctuations.

[0069] Figure 9 This is a pressure-enthalpy diagram of a non-azeotropic refrigerant mixture cycle in defrosting mode according to a certain embodiment of the present invention; wherein, the middle part is the non-azeotropic refrigerant mixture, the lower left part is the medium-temperature refrigerant component, and the upper right part is the low-temperature refrigerant component.

[0070] For any points not covered above, existing technologies shall apply.

[0071] In this document, the directional terms such as front, back, top, and bottom are defined based on the location of the components in the accompanying drawings and their relative positions to each other, solely for the purpose of clarity and convenience in expressing the technical solution. It should be understood that the use of these directional terms should not limit the scope of protection claimed in this application.

[0072] Where there is no conflict, the above embodiments and features described herein can be combined with each other.

[0073] 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 within the protection scope of the present invention.

Claims

1. A hydrogen energy automobile self-recovery heat pump system, characterized in that, The system comprises a gas-liquid separator, a compressor, an indoor heat exchanger, a non-azeotropic working medium gas-liquid separator, a six-way heat exchanger, and an outdoor heat exchanger. The suction port of the compressor is in communication with the gas outlet of the gas-liquid separator; the exhaust port of the compressor is in communication with the first interface of the indoor heat exchanger through a heating solenoid valve; the second interface of the indoor heat exchanger is in communication with the first interface of the non-azeotropic working medium gas-liquid separator through the six-way heat exchanger and a supercooling solenoid valve; the second interface of the non-azeotropic working medium gas-liquid separator is in communication with the inlet of the outdoor heat exchanger through the six-way heat exchanger and a heating electronic expansion valve; the third interface of the non-azeotropic working medium gas-liquid separator is in communication with the inlet of the gas-liquid separator through a high-boiling-point working medium electronic expansion valve and the six-way heat exchanger; the non-azeotropic working medium gas-liquid separator is used for separating the non-azeotropic mixed refrigerant into liquid medium-temperature refrigerant and gaseous low-temperature refrigerant; the outlet of the outdoor heat exchanger is in communication with the air supplementing port of the compressor and the inlet of the gas-liquid separator through a gas supplementing and enthalpy increasing solenoid valve and a return gas solenoid valve, respectively; Further comprising a first refrigeration solenoid valve and a second refrigeration solenoid valve, the outlet of the compressor is in communication with the inlet of the outdoor heat exchanger through the first refrigeration solenoid valve; the second refrigeration solenoid valve is connected in parallel with the heating electronic expansion valve and the outdoor heat exchanger; And / or further comprising a refrigeration electronic expansion valve and a third refrigeration solenoid valve; the second interface of the indoor heat exchanger is further in communication with the first interface of the non-azeotropic working medium gas-liquid separator through the refrigeration electronic expansion valve; the first interface of the indoor heat exchanger is further in communication with the inlet of the gas-liquid separator through the third refrigeration solenoid valve; Further comprising an air conditioner box shell and a supply air blower; the supply air blower and the indoor heat exchanger are arranged in the air conditioner box shell; the supply air blower is matched with the air conditioner box shell and is used for guiding the gas after heat exchange of the indoor heat exchanger into a room; And / or further comprising a cooling axial flow fan, which is arranged corresponding to the outdoor heat exchanger.

2. The hydrogen car auto-cascade heat pump system of claim 1, wherein, The second interface of the indoor heat exchanger is in communication with the first interface of the non-azeotropic working medium gas-liquid separator through the six-way heat exchanger and a supercooling solenoid valve in sequence; And / or the second interface of the non-azeotropic working medium gas-liquid separator is in communication with the inlet of the outdoor heat exchanger through the six-way heat exchanger and a heating electronic expansion valve in sequence; And / or the third interface of the non-azeotropic working medium gas-liquid separator is in communication with the inlet of the gas-liquid separator through a high-boiling-point working medium electronic expansion valve and the six-way heat exchanger in sequence.

3. The hydrogen car auto-cascade heat pump system of claim 1, wherein, The gas supplementing and enthalpy increasing solenoid valve and the return gas solenoid valve are replaced by a first proportional three-way valve; the outlet of the outdoor heat exchanger is in communication with the air supplementing port of the compressor and the inlet of the gas-liquid separator through the first proportional three-way valve, respectively.

4. The hydrogen car auto-cascade heat pump system of claim 1, wherein, The first refrigeration solenoid valve and the heating solenoid valve are replaced by a second proportional three-way valve; the exhaust port of the compressor is in communication with the first interface of the indoor heat exchanger and the inlet of the outdoor heat exchanger through the second proportional three-way valve, respectively.

5. A thermal management method applied to the hydrogen energy automobile auto-cascade heat pump system of any one of claims 1-4, characterized in that, The method comprises the following steps: Obtaining a heat management mode of the self-recovering heat pump system of the hydrogen energy automobile; When the heat management mode is a heating mode, the proportion of gaseous low-temperature refrigerant from the outdoor heat exchanger into the gas-liquid separator and the compressor is adjusted to meet the heating demand.

6. The thermal management method of claim 5, wherein, When the heat management mode is a heating mode, the operation method of the hydrogen energy automobile self-complex heat pump system is as follows: The non-azeotropic mixed refrigerant gas in the gas-liquid separator is compressed and output by the compressor, flows through the indoor heat exchanger to be cooled into a non-azeotropic mixed refrigerant gas-liquid mixture and realize the heating of indoor air; The non-azeotropic mixed refrigerant gas-liquid mixture is cooled by the six-way heat exchanger, enters the non-azeotropic working medium gas-liquid separator, and is separated into liquid medium-temperature refrigerant and gaseous low-temperature refrigerant; wherein the liquid medium-temperature refrigerant is decompressed into a gas-liquid two-phase medium-temperature refrigerant by the high-boiling-point working medium electronic expansion valve, and becomes gaseous medium-temperature refrigerant after being heated and warmed by the six-way heat exchanger and flowing into the gas-liquid separator; the gaseous low-temperature refrigerant is cooled by the six-way heat exchanger, flows through the heating electronic expansion valve to be decompressed into a gas-liquid two-phase low-temperature refrigerant, becomes gaseous low-temperature refrigerant after absorbing heat from the ambient air by flowing through the outdoor heat exchanger, enters the compressor through the gas supplementing and enthalpy increasing electromagnetic valve and / or enters the gas-liquid separator through the gas return electromagnetic valve; the gaseous medium-temperature refrigerant and the gaseous low-temperature refrigerant in the gas-liquid separator are re-sucked into the compressor to form a cycle.

7. The thermal management method of claim 5, wherein, When the heat management mode is a refrigeration mode, the operation method of the hydrogen energy automobile self-complex heat pump system is as follows: The non-azeotropic mixed refrigerant gas in the gas-liquid separator is compressed and output by the compressor, flows through the outdoor heat exchanger to be cooled into a non-azeotropic mixed refrigerant gas-liquid mixture, enters the non-azeotropic working medium gas-liquid separator, and obtains gaseous low-temperature refrigerant and liquid medium-temperature refrigerant; wherein the gaseous low-temperature refrigerant is stored in the tank body of the non-azeotropic working medium gas-liquid separator; the liquid medium-temperature refrigerant is decompressed into a gas-liquid two-phase medium-temperature refrigerant by the refrigeration electronic expansion valve, flows through the indoor heat exchanger to cool indoor air, becomes gaseous medium-temperature refrigerant, is re-sucked into the compressor through the gas-liquid separator, and completes the cycle refrigeration through the gaseous medium-temperature refrigerant.

8. The thermal management method of any of claims 5-7, wherein, When the heat management mode is a defrosting mode, the operation method of the hydrogen energy automobile self-complex heat pump system is as follows: The compressor outputs the non-azeotropic mixed refrigerant gas in the gas-liquid separator after compression, part of the compressed non-azeotropic mixed refrigerant gas flows through the outdoor heat exchanger to release heat for defrosting and becomes a non-azeotropic mixed refrigerant gas-liquid mixture, is cooled by the six-way heat exchanger into a non-azeotropic mixed refrigerant liquid mixture, and enters the non-azeotropic working medium gas-liquid separator; the other part of the compressed non-azeotropic mixed refrigerant gas flows through the indoor heat exchanger to heat indoor air, is cooled and becomes a non-azeotropic mixed refrigerant gas-liquid mixture, is cooled by the six-way heat exchanger, and enters the non-azeotropic working medium gas-liquid separator; wherein the non-azeotropic mixed refrigerant liquid mixture in the non-azeotropic working medium gas-liquid separator is decompressed by the high-boiling-point working medium refrigeration electronic expansion valve into a non-azeotropic mixed refrigerant gas-liquid mixture, flows through the six-way heat exchanger to absorb heat and becomes a non-azeotropic mixed refrigerant gaseous mixture, flows into the gas-liquid separator, and is re-sucked into the compressor to circulate.

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