Thermal management system of hydrogen fuel cell automobile and control method of thermal management system

Abstract

The invention discloses a hydrogen fuel cell automobile thermal management system and a control method thereof, and the hydrogen fuel cell automobile thermal management system comprises a transcritical carbon dioxide heat pump system with a double-heat-source heat exchanger group, a bimodal phase change energy storage device and a fuel cell. The cold energy of the transcritical carbon dioxide heat pump system is absorbed through the cold storage loop in summer; in the starting process of the fuel cell in winter and summer, the fuel cell is preheated through the electric pile preheating loop; after the fuel cell is started, heat of the fuel cell is absorbed through the electric pile waste heat loop; under the working conditions of parking and defrosting in winter, heat of the bimodal phase change energy storage device is absorbed through the heat release loop; under the defrosting working condition, heat of the dual-mode phase change energy storage device is absorbed through the defrosting loop; and under the summer parking working condition, the cold energy of the dual-mode phase change energy storage device is absorbed through the cold release loop. Low-temperature quick starting, all-weather efficient operation and dynamic working condition stable temperature control of the hydrogen fuel cell automobile can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile thermal management, and in particular to a hydrogen fuel cell automobile thermal management system and a control method thereof. Background Art

[0002] The thermal management system of existing hydrogen fuel cell vehicles generally adopts a design in which the heat pump air conditioning and the fuel cell cooling circuit are independent of each other. This has led to a series of problems in actual use, mainly including the following aspects: 1. Low temperature start: high power consumption and slow preheating Problem manifestation: When the temperature is low in winter, the fuel cell stack needs to rely on an additional electric heating device (PTC heater) to heat up when starting, which will increase the power consumption at startup by 10%-15%. It takes 8-12 minutes to complete preheating, that is, the car needs to be warmed up before driving in winter, which wastes electricity and delays time.

[0003] 2. Winter heating: poor effect and reduced battery life Unstable heating effect: Under a single heat source in a low-temperature environment, the heating effect of traditional heat pump air conditioners is poor, resulting in the car interior not being able to warm up.

[0004] The temperature in the car fluctuates between hot and cold during defrosting: When the air conditioner is defrosted, the heating needs to be suspended, causing the temperature in the car to drop suddenly, just like the room becomes cold when the home air conditioner is defrosted, which is very uncomfortable.

[0005] Braking conditions waste energy: When parking in winter, the power of the heat pump air conditioner is reduced, and electric auxiliary heating is needed to keep warm, which increases power consumption and shortens the cruising range.

[0006] 3. Summer cooling: large fluctuations in effect and high energy consumption Unstable cooling capacity: When driving in the summer, if only a single ambient heat source (such as outside air) is used, the air conditioner's cooling capacity will fluctuate by ±30% depending on the operating conditions. It may suddenly become hot or cold, resulting in a poor experience.

[0007] Increased power consumption during braking: If you want to pre-cool the car before parking in summer, you need to keep the compressor running for more than 10 minutes, which is equivalent to "idling" power consumption and wastes energy.

[0008] 4. Energy waste: Fuel cell waste heat is dissipated uselessly Fuel cells generate heat (waste heat) when working, but the existing system does not effectively recycle and utilize this heat - it is not used for heating in winter and not used to assist cooling in summer. This is equivalent to "wasting free energy in vain", resulting in low overall efficiency of the system.

[0009] The root cause of the above technical problems is that the heat pump air conditioning and cooling circuit "work independently" and cannot work together flexibly according to different seasons and working conditions, resulting in the system being unable to achieve the three core goals of "rapid start-up at low temperatures, efficient operation around the clock, and stable temperature control under dynamic working conditions."

[0010] It should be noted that the above technical information is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or implication in any form that the above technical information constitutes prior art already known to those skilled in the art. Summary of the Invention

[0011] In response to the deficiencies in the above-mentioned background technology, the present invention proposes a hydrogen fuel cell vehicle thermal management system and a control method thereof. The technical problem to be solved is: how to achieve rapid low-temperature start-up, efficient all-weather operation, and stable temperature control of hydrogen fuel cell vehicles under dynamic working conditions.

[0012] The technical solution of the present invention is: A hydrogen fuel cell vehicle thermal management system includes a transcritical carbon dioxide heat pump system with a dual-heat source heat exchanger group, a dual-mode phase change energy storage device, and a fuel cell.

[0013] The transcritical carbon dioxide heat pump system: during the fuel cell startup process in winter and summer, the fuel cell is preheated through the stack preheating circuit; after the fuel cell is started, the heat of the fuel cell is absorbed through the stack waste heat circuit; in winter parking and defrosting conditions, the heat of the dual-mode phase change energy storage device is absorbed through the heat release circuit; in defrosting conditions, the heat of the dual-mode phase change energy storage device is absorbed through the defrost circuit; in summer parking conditions, the cooling capacity of the dual-mode phase change energy storage device is absorbed through the cooling release circuit.

[0014] The dual-mode phase change energy storage device absorbs heat from the fuel cell through a heat storage loop in winter, and absorbs cold energy from the transcritical carbon dioxide heat pump system through a cold storage loop in summer.

[0015] On the basis of the above technical solutions, as the preferred technical solution for the thermal management system of hydrogen fuel cell vehicles, the control system controls the on-off of each circuit and the circulation and transportation of the medium.

[0016] On the basis of the above technical solution, as the preferred technical solution for the thermal management system of hydrogen fuel cell vehicles, the transcritical carbon dioxide heat pump system includes a compressor, a solenoid valve III, a gas cooler, a solenoid valve II, an ejector, and a second evaporator which are connected in a cycle in sequence. A branch is provided between the secondary fluid inlet and the primary fluid inlet of the ejector, and an expansion valve, a solenoid valve IX, a first evaporator, and a solenoid valve XV are provided in sequence on the branch.

[0017] On the basis of the above technical solution, as the preferred technical solution for the thermal management system of hydrogen fuel cell vehicles, the stack preheating circuit includes a heat exchanger I circulatedly connected to the fuel cell through a heat release circuit 1, and a pump I and a solenoid valve IV are provided on the heat release circuit 1; the heat exchanger I is circulatedly connected to the upstream and downstream of the gas cooler through a heat absorption circuit 1, and a solenoid valve I is provided on the heat absorption circuit 1.

[0018] On the basis of the above technical solution, as the preferred technical solution for the thermal management system of hydrogen fuel cell vehicles, the stack waste heat circuit includes a heat exchanger II connected to the fuel cell cycle through a heat absorption circuit 2, and the heat absorption circuit 2 is provided with a solenoid valve VII and a pump III. The heat exchanger II is connected to the second evaporator cycle through a heat release circuit 2, and the heat release circuit 2 is provided with a solenoid valve XVI and a pump V.

[0019] On the basis of the above technical solution, as the preferred technical solution for the thermal management system of hydrogen fuel cell vehicles, the heat storage circuit is connected to the heat absorption circuit 2 through the solenoid valve V and the solenoid valve XI; the heat release circuit is circulated between the dual-modal phase change energy storage device and the gas cooler, and the solenoid valve VI, pump II, and solenoid valve X are provided on the heat release pipeline.

[0020] On the basis of the above technical solution, as the preferred technical solution for the thermal management system of a hydrogen fuel cell vehicle, the defrost circuit includes a solenoid valve XIII connected between the heat release circuit and the first evaporator, and a solenoid valve XIV connected between the first evaporator and the dual-mode phase change energy storage device.

[0021] On the basis of the above technical solution, as the preferred technical solution for the thermal management system of hydrogen fuel cell vehicles, the cold storage circuit includes branch pipe 1 connected between the expansion valve and the first evaporator, and branch pipe 2 connected between the ejector and the first evaporator. Branch pipe 1 and branch pipe 2 are circulated through a bimodal phase change energy storage device. The cold storage circuit is provided with a pump IV, a solenoid valve XII, and a solenoid valve XIV; the cold release circuit has the same structure as the cold storage circuit.

[0022] A method for controlling a thermal management system of a hydrogen fuel cell vehicle adopts the thermal management system of a hydrogen fuel cell vehicle described in any of the above technical solutions, including a winter heating control mode, a winter heat storage control mode, a winter heat release control mode, a winter defrost control mode, a summer cooling control mode, a summer cold storage control mode, and a summer cold release control mode.

[0023] Based on the above technical solutions, as a preferred technical solution for the control method of the thermal management system of a hydrogen fuel cell vehicle, the winter heating control mode is as follows: under the startup condition of the fuel cell, solenoid valve I, solenoid valve II, solenoid valve III, solenoid valve IV, solenoid valve IX, solenoid valve XV, expansion valve, and pump I are opened, and the lithium battery provides power for the compressor. After the compressor compresses the carbon dioxide refrigerant to increase its pressure and temperature, a portion passes through the gas cooler to heat the air, and a portion enters the heat exchanger I to transfer heat to ethylene glycol, which preheats the fuel cell through the ethylene glycol to quickly reach the operating temperature of the fuel cell; the low-temperature and high-pressure refrigerant after heat exchange in the gas cooler and heat exchanger I is divided into two paths, one path entering the ejector as a primary fluid, and the other path forming a low-temperature and low-pressure refrigerant after passing through the expansion valve and entering the first evaporator. The refrigerant after absorbing heat in the evaporator enters the ejector as a secondary fluid. The two fluids entering the ejector are mixed in the ejector mixing chamber, decelerated and pressurized in the diffusion chamber, and then enter the second evaporator to absorb waste heat from the fuel cell and ambient heat. The low-pressure refrigerant exiting the second evaporator enters the compressor, forming a heating circuit for the fuel cell vehicle. After the fuel cell is started, the solenoid valve I, pump I, and solenoid valve IV are closed, and the solenoid valve VII, pump III, pump V, and solenoid valve XVI are opened.

[0024] Based on the above technical solution, as a preferred technical solution for the control method of the thermal management system of a hydrogen fuel cell vehicle, the winter heat storage control mode: Based on the winter heating control mode, solenoid valves V and XI are opened. The waste heat generated during fuel cell operation passes through the ethylene glycol liquid and enters heat exchanger II and the dual-mode phase change energy storage device in sequence. The dual-mode phase change energy storage device absorbs the heat carried by the ethylene glycol, and then flows back to the fuel cell through heat exchanger II.

[0025] Based on the above technical solution, as a preferred technical solution for the control method of the thermal management system of a hydrogen fuel cell vehicle, the winter heat release control mode: During the braking, parking, or defrosting conditions of the hydrogen fuel cell vehicle, solenoid valves VI and X, and pump II are opened. Pump II directs the gaseous refrigerant into the dual-mode phase-change energy storage device, which absorbs heat and heats the device. The refrigerant then flows through solenoid valve VI into the gas cooler, absorbing the cold air to generate heat. Finally, the refrigerant flows through solenoid valve X and reenters the dual-mode phase-change energy storage device, completing a loop.

[0026] Based on the above technical solution, as a preferred technical solution for the control method of the thermal management system of a hydrogen fuel cell vehicle, the winter defrost control mode: based on the winter heat release control mode, solenoid valves XIII and XIV are opened. After absorbing heat and heating from the dual-mode phase change energy storage device, the refrigerant passes through solenoid valve XIII, then passes through the second evaporator to defrost the second evaporator, and then flows through solenoid valve XIV back to the dual-mode phase change energy storage device, completing the circuit and achieving parallel operation of heating and defrosting.

[0027] On the basis of the above technical solutions, as the preferred technical solution of the control method of the thermal management system of hydrogen fuel cell vehicles, the summer cooling control mode is: under the starting condition of the fuel cell, open the solenoid valve I, solenoid valve II, solenoid valve III, expansion valve, solenoid valve IX, solenoid valve XVI, pump I, and solenoid valve IV, and the lithium battery provides power for the compressor. The compressor compresses the carbon dioxide refrigerant to increase its pressure and temperature. A part of it is heat-exchanged through the gas cooler, and a part of it enters the heat exchanger I to transfer the heat to ethylene glycol, and the ethylene glycol is used to preheat the fuel cell so that it can quickly reach the combustion temperature. At the operating temperature of the fuel cell, the low-temperature, high-pressure refrigerant, after heat exchange in the gas cooler and heat exchanger I, is split into two paths: one enters the ejector as the primary fluid, and the other passes through the expansion valve to form a low-temperature, low-pressure refrigerant, entering the first evaporator. After absorbing heat in the first evaporator, the refrigerant enters the ejector as the secondary fluid. The two fluids entering the ejector are mixed in the ejector mixing chamber, decelerated and pressurized in the diffusion chamber, and then enter the second evaporator, absorbing waste heat from the fuel cell and ambient heat. The low-pressure refrigerant from the second evaporator enters the compressor, forming the refrigeration circuit of the heat pump air conditioner and completing the refrigeration cycle. After the fuel cell is started, solenoid valve I, pump I, and solenoid valve IV are closed, and solenoid valve VII, pump III, pump, and solenoid valve XVI are opened.

[0028] Based on the above technical solution, as a preferred technical solution for the control method of the thermal management system of a hydrogen fuel cell vehicle, the summer cold storage control mode: Based on the summer cooling control mode, pump IV, solenoid valve XII, and solenoid valve XIV are opened. The low-temperature, high-pressure refrigerant from the gas cooler enters the expansion valve, forming a low-temperature, low-pressure refrigerant, which is then split into two paths: one entering the first evaporator and the other entering the bimodal phase-change energy storage device. The bimodal phase-change energy storage device absorbs the cold energy from the low-temperature, low-pressure refrigerant. After entering the first evaporator, the low-temperature, low-pressure refrigerant merges with the refrigerant that has passed through the bimodal phase-change energy storage device and enters the refrigeration circuit.

[0029] Based on the above technical solution, as a preferred technical solution for the control method of the thermal management system of a hydrogen fuel cell vehicle, the summer cooling control mode: when the hydrogen fuel cell vehicle is in the braking and parking condition, pump IV, solenoid valves XII, and solenoid valves XIV are turned on. Low-temperature, low-pressure liquid refrigerant enters the dual-mode phase-change energy storage device through pump IV to absorb cold energy, passes through the first evaporator to absorb heat from the environment, enters solenoid valve XIV, and finally returns to the dual-mode phase-change energy storage device to complete the circuit.

[0030] Compared with the existing technology, the hydrogen fuel cell vehicle thermal management system and its control method proposed in the present invention can achieve rapid low-temperature startup, efficient all-weather operation, and stable temperature control under dynamic operating conditions for hydrogen fuel cell vehicles. The present invention uses a transcritical carbon dioxide heat pump system started by a lithium battery to directly heat the fuel cell stack through the high-temperature and high-pressure refrigerant output by the compressor, achieving rapid startup in a low-temperature environment, reducing the stack startup energy consumption, and extending the cruising range. A dual-modal phase change energy storage device is used to achieve dynamic storage and release of fuel cell waste heat and refrigeration system cooling capacity. A portion of the fuel cell waste heat is stored through phase change heat storage. A heat release circuit and a defrost circuit are used to ensure cabin thermal comfort while reducing the impact of the defrost process on system heating to a negligible level, thereby reducing the winter cruising range attenuation rate. The supercooled refrigerant after storage after expansion through phase change cold storage is used for cabin pre-cooling under vehicle braking conditions, shortening the cabin pre-cooling time in summer. The dual-source heat exchanger integrates the ambient heat source with the fuel cell coolant source through the first and second evaporators. This utilizes the fuel cell's waste heat to address the single air source heat source issue, improving heating efficiency in low winter temperatures. This system offers improved energy efficiency compared to single-source heat systems and reduces fluctuations in cooling capacity due to changes in vehicle operating conditions. Compared to traditional fuel-powered vehicles, this system eliminates fuel consumption in the air conditioning system; compared to pure electric vehicles, it offers increased range and longer battery life; and compared to existing hydrogen fuel cell vehicles, it offers a shorter cold start-up time, improved overall energy efficiency, better endurance, and a longer lifespan. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 This is a schematic diagram of the principle of the thermal management system of a hydrogen fuel cell vehicle.

[0033] Description of Figure Numbers: 1-Heat exchanger I, 2-Solenoid valve I, 3-Pump I, 4-Solenoid valve II, 5-Gas cooler, 6-Solenoid valve III, 7-Solenoid valve IV, 8-Fuel cell, 9-Solenoid valve V, 10-Dual-mode phase change energy storage device, 11-Compressor, 12-Lithium battery, 13-Solenoid valve VI, 14-Solenoid valve VII, 15-Pump II, 16-Solenoid valve IX, 17-Expansion valve, 18-Ejector, 19-Solenoid valve X, 20-Second evaporator, 21-Pump III, 22-Solenoid valve XI, 23-Heat exchanger II, 24-Pump IV, 25-Solenoid valve XII, 26-Solenoid valve XIII, 27-First evaporator, 28-Solenoid valve XIV, 29-Solenoid valve XV, 30-Solenoid valve XVI, 31-Pump V. DETAILED DESCRIPTION

[0034] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the core concept of the present invention and the following embodiments, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The present application provides these embodiments to make this application thorough and complete, and to fully express the scope of this application to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values ​​set forth in these embodiments should be interpreted as merely exemplary, and not as limiting.

[0036] It should be noted that the words "one", "two", "first", "second", "branch one", "branch two", "branch one", "branch two" and similar words used in this application do not indicate any order, quantity or importance, but are only used to distinguish different parts.

[0037] It should also be noted that in the description of this application, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.

[0038] All terms used in this application have the same meaning as understood by one of ordinary skill in the art to which this application belongs, unless otherwise specifically defined. It should also be understood that terms defined in, for example, common dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and should not be interpreted in an idealized or highly formal sense, unless explicitly defined as such herein.

[0039] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0040] The present invention employs the following technical solutions: a hydrogen fuel cell vehicle thermal management system comprising a fuel cell stack, a transcritical carbon dioxide heat pump system, a dual-mode phase-change energy storage device, a dual-heat-source heat exchanger assembly, and a control module. The compressor, activated by a lithium battery, outputs high-temperature, high-pressure carbon dioxide refrigerant, which forms a closed loop with the transcritical carbon dioxide heat pump system via a stack preheating branch, enabling rapid stack startup in low-temperature environments. The dual-mode phase-change energy storage device is connected to the compressor outlet, the expansion valve outlet, and the fuel cell glycol coolant outlet, respectively. In winter, it stores stack waste heat for defrosting and cabin heating, and in summer, it stores cooling capacity to shorten cabin precooling time under braking conditions. The dual-heat-source heat exchanger assembly, comprising a first evaporator and a second evaporator, utilizes both ambient heat and fuel cell coolant. Using fuel cell waste heat, the dual-heat-source heat exchanger solves the problem of a single air-source heat source, improves heating efficiency in low winter temperatures, and reduces fluctuations in cooling capacity in summer due to varying vehicle operating conditions. This ensures efficient all-weather operation and stable temperature control under dynamic operating conditions, thereby achieving comprehensive thermal management energy efficiency.

[0041] The specific embodiments are as follows: A hydrogen fuel cell vehicle thermal management system and control method thereof, such as Figure 1 As shown, the system includes a transcritical CO2 heat pump system with a dual-source heat exchanger group, a dual-mode phase change energy storage device 10, and a fuel cell 8. The dual-source heat exchanger group in the transcritical CO2 heat pump system integrates the ambient heat source with the coolant source of the fuel cell 8 through a first evaporator 27 and a second evaporator 20. The waste heat of the fuel cell 8 solves the problem of a single air source heat source, improving the heating effect in low winter temperatures. This improves energy efficiency compared to a single heat source system and reduces fluctuations in cooling capacity caused by changes in vehicle operating conditions. The dual-mode phase change energy storage device 10 can store heat from the coolant source of the fuel cell 8 in winter to provide heat to the transcritical CO2 heat pump system during braking, parking, and defrosting. It can also store cold from the transcritical CO2 heat pump system in summer to provide heating and cooling to the transcritical CO2 heat pump system during braking, parking, and defrosting.

[0042] Specifically, the transcritical carbon dioxide heat pump system: during the startup process of the fuel cell 8 in winter and summer, the fuel cell is preheated through the stack preheating circuit; after the fuel cell 8 is started, the heat of the fuel cell 8 is absorbed through the stack waste heat circuit; under winter parking and defrosting conditions, the heat of the dual-mode phase change energy storage device 10 is absorbed through the heat release circuit; under defrosting conditions, the heat of the dual-mode phase change energy storage device 10 is absorbed through the defrost circuit; under summer parking conditions, the cooling capacity of the dual-mode phase change energy storage device 10 is absorbed through the cooling release circuit.

[0043] The dual-mode phase change energy storage device 10 absorbs heat from the fuel cell 8 through a heat storage loop in winter, and absorbs cold energy from the transcritical carbon dioxide heat pump system through a cold storage loop in summer.

[0044] Based on the above embodiment, as a preferred embodiment of a hydrogen fuel cell vehicle thermal management system, a control system controls the on / off switching of each circuit and the circulation of the medium. The control system includes a controller that controls the on / off switching of the solenoid valves in each circuit. The controller also controls the motors that drive the pumps in each circuit. The compressor 11 in the transcritical CO2 heat pump system is driven by a lithium battery 12.

[0045] On the basis of the above embodiments, as a preferred embodiment of the thermal management system of a hydrogen fuel cell vehicle, the transcritical carbon dioxide heat pump system includes a compressor 11, a solenoid valve III6, a gas cooler 5, a solenoid valve II4, an ejector 18, and a second evaporator 20 that are cyclically connected in sequence. A branch is provided between the secondary fluid inlet and the primary fluid inlet of the ejector 18, and an expansion valve 17, a solenoid valve IX16, a first evaporator 27, and a solenoid valve XV29 are provided in sequence on the branch.

[0046] On the basis of the above embodiments, as a preferred embodiment of the thermal management system of a hydrogen fuel cell vehicle, the stack preheating circuit includes a heat exchanger I1 circulatedly connected to the fuel cell 8 through a heat release circuit 1, and a pump I3 and a solenoid valve IV7 are provided on the heat release circuit 1; the heat exchanger I1 is circulatedly connected to the upstream and downstream of the gas cooler 5 through a heat absorption circuit 1, and a solenoid valve I2 is provided on the heat absorption circuit 1.

[0047] On the basis of the above embodiments, as a preferred embodiment of the thermal management system of a hydrogen fuel cell vehicle, the stack waste heat circuit includes a heat exchanger II23 circulatedly connected to the fuel cell 8 through a second heat absorption circuit, and the second heat absorption circuit is provided with a solenoid valve VII14 and a pump III21. The heat exchanger II23 is circulatedly connected to the second evaporator 20 through a second heat release circuit, and the second heat release circuit is provided with a solenoid valve XVI30 and a pump V31.

[0048] On the basis of the above embodiment, as a preferred embodiment of the thermal management system of a hydrogen fuel cell vehicle, the heat storage circuit is connected to the heat absorption circuit 2 through the solenoid valve V9 and the solenoid valve XI22; the heat release circuit is circulated between the dual-modal phase change energy storage device 10 and the gas cooler 5, and the solenoid valve VI13, pump II15, and solenoid valve X19 are provided on the heat release pipeline.

[0049] Based on the above embodiments, as a preferred embodiment of the thermal management system of a hydrogen fuel cell vehicle, the defrost circuit includes a solenoid valve XIII26 connected between the heat release circuit and the first evaporator 27, and a solenoid valve XIV28 connected between the first evaporator 27 and the dual-mode phase change energy storage device 10.

[0050] On the basis of the above embodiments, as a preferred embodiment of the thermal management system of a hydrogen fuel cell vehicle, the cold storage circuit includes a branch pipe 1 connected between the expansion valve 17 and the first evaporator 27, and a branch pipe 2 connected between the ejector 18 and the first evaporator 27. Branch pipe 1 and branch pipe 2 are circulated through a dual-modal phase change energy storage device 10. A pump IV24, a solenoid valve XII25, and a solenoid valve XIV28 are provided on the cold storage circuit; the cold release circuit has the same structure as the cold storage circuit.

[0051] Specifically, the medium outlet of compressor 11 is divided into two routes. One route leads to heat exchanger I1 through solenoid valve I2. After passing through heat exchanger I1, it is connected to the pipeline between solenoid valve II4 and the primary fluid inlet of ejector 18, i.e., heat absorption circuit 1. The other route leads to gas cooler 5 through solenoid valve III6. The medium outlet of gas cooler 5 is connected to the primary fluid inlet of ejector 18 through solenoid valve II, and the medium outlet of ejector 18 is connected to the medium inlet of compressor 11 through second evaporator 20. The pipeline behind solenoid valve II4 is divided into two routes. One route is connected to the primary fluid inlet of ejector 18, and the other route is connected to the secondary fluid inlet of ejector 18 through expansion valve 17, solenoid valve IX16, first evaporator 27, and solenoid valve XV29 in sequence.

[0052] The main components of the stack preheating circuit are: a heat release circuit 1 and a heat absorption circuit 1 of the heat exchanger I1. The heat release circuit 1 is a pipeline circulated between the heat exchanger I1 and the fuel cell 8. The heat release circuit 1 is provided with a solenoid valve IV7 and a pump I3. The heat absorption circuit 1 is a pipeline circulated with the gas cooler 5.

[0053] The stack waste heat circuit primarily consists of a heat absorption circuit 2 and a heat release circuit 2 of heat exchanger II 23. The heat absorption circuit 2 is circulated between the fuel cell 8 and heat exchanger II 23, while the heat release circuit 2 is circulated between the heat exchanger II 23 and the second evaporator 20. A solenoid valve VII 14 and a pump III are provided on one branch of the heat absorption circuit 2, while a solenoid valve XVI 30 and a pump V 31 are provided on one branch of the heat release circuit 2 to circulate the heat exchange medium.

[0054] The main components of the heat storage circuit are: branch one on the pipeline connected between the solenoid valve VII14 and the pump III, and branch two on the pipeline connected between the fuel cell and the heat exchanger II23. Branch one is provided with a solenoid valve XI22, and branch two is provided with a solenoid valve V9. Branch one and branch two are interconnected and pass through a dual-modal phase change energy storage device 10.

[0055] The main structure of the heat release circuit is as follows: a first branch pipe connected to the dual-mode phase change energy storage device 10 is connected to the pipeline between the solenoid valve III6 and the gas cooler 5, a solenoid valve X19 and a pump II15 are provided on the first branch pipe, a second branch pipe is provided in communication with the first branch pipe, one end of the second branch pipe is connected to the pipeline between the gas cooler 5 and the solenoid valve II4, and the other end is connected to the first branch pipe through the dual-mode phase change energy storage device 10, and the solenoid valve VI13 is provided on the second branch pipe.

[0056] The defrost circuit primarily consists of a branch pipe 1 equipped with a solenoid valve XIII 26 and a branch pipe 2 equipped with a solenoid valve XIV 28. Branch pipes 1 and 2 are cyclically connected via a bimodal phase-change energy storage device 10 and the first evaporator 27. Specifically, the two ends of branch pipe 1 are connected to the pipeline between the solenoid valve IX 16 and the first evaporator 27 and the pipeline between the solenoid valve VI 13 and the bimodal phase-change energy storage device 10, respectively. The two ends of branch pipe 2 are connected to the pipeline between the solenoid valve XV 29 and the first evaporator 27 and the bimodal phase-change energy storage device 10, respectively.

[0057] The cold storage circuit is primarily composed of a branch pipe 1 equipped with a solenoid valve XII25 and a pump IV24, and a branch pipe 2 equipped with a solenoid valve XIV28. Branch pipes 1 and 2 are cyclically connected via a bimodal phase-change energy storage device 10 and a first evaporator 27. Specifically, the two ends of branch pipe 1 are connected to the pipeline between the solenoid valve IX16 and the first evaporator 27 and to the bimodal phase-change energy storage device 10, respectively. The two ends of branch pipe 2 are connected to the pipeline between the solenoid valve XV29 and the first evaporator 27 and to the bimodal phase-change energy storage device 10, respectively.

[0058] The structure of the cold release circuit is the same as that of the cold storage circuit. The difference lies in the status of the corresponding solenoid valve and pump. For details, please refer to the following description of the control method of the thermal management system of a hydrogen fuel cell vehicle.

[0059] A method for controlling a thermal management system of a hydrogen fuel cell vehicle adopts the thermal management system of a hydrogen fuel cell vehicle described in any of the above embodiments, including a winter heating control mode, a winter heat storage control mode, a winter heat release control mode, a winter defrost control mode, a summer cooling control mode, a summer cold storage control mode, and a summer cold release control mode.

[0060] On the basis of the above embodiment, as a preferred embodiment of the control method of the thermal management system of a hydrogen fuel cell vehicle, the winter heating control mode is as follows: under the starting condition of the fuel cell 8, the solenoid valve I2, the solenoid valve II4, the solenoid valve III6, the solenoid valve IV7, the solenoid valve IX16, the solenoid valve XV29, the expansion valve 17, and the pump I3 are opened, and the lithium battery 12 provides power for the compressor 11. The compressor 11 compresses the carbon dioxide refrigerant to increase its pressure and temperature. A part of it passes through the gas cooler 5 to heat the air, and a part enters the heat exchanger I1 to transfer the heat to the ethylene glycol, and the ethylene glycol is used to preheat the fuel cell 8 to make it fast. The low-temperature, high-pressure refrigerant, after heat exchange in gas cooler 5 and heat exchanger I1, is split into two paths: one enters ejector 18 as the primary fluid, and the other passes through expansion valve 17 to form a low-temperature, low-pressure refrigerant, entering first evaporator 27. After absorbing heat in evaporator 27, the refrigerant enters ejector 18 as the secondary fluid. The two fluids entering ejector 18 are mixed in the ejector mixing chamber, decelerated and pressurized in the diffusion chamber, and then enter second evaporator 20, absorbing waste heat from the fuel cell and ambient heat. The low-pressure refrigerant exiting second evaporator 20 enters compressor 11, forming the fuel cell vehicle's heating circuit. After fuel cell 8 is started, solenoid valve I2, pump I3, and solenoid valve IV7 are closed, while solenoid valve VII14, pump III21, pump V31, and solenoid valve XVI30 are opened.

[0061] Based on the above embodiment, as a preferred embodiment of the control method for the thermal management system of a hydrogen fuel cell vehicle, the winter heat storage control mode: Based on the winter heating control mode, solenoid valve V9 and solenoid valve XI22 are opened. The waste heat generated by the operation of the fuel cell 8 passes through the ethylene glycol liquid and enters the heat exchanger II23 and the dual-mode phase change energy storage device 10. The dual-mode phase change energy storage device 10 absorbs the heat carried by the ethylene glycol, and then flows back to the fuel cell 8 through the heat exchanger II23.

[0062] Based on the above embodiment, as a preferred embodiment of the control method for the thermal management system of a hydrogen fuel cell vehicle, the winter heat release control mode is as follows: when the hydrogen fuel cell vehicle is in the braking, parking, or defrosting state, solenoid valve VI13, solenoid valve X19, and pump II15 are opened. Pump II15 directs the gaseous refrigerant into the dual-mode phase-change energy storage device 10, where it absorbs heat and heats up. The refrigerant then flows through solenoid valve VI13 into the gas cooler 5, absorbing the cold air to generate heat. Finally, the refrigerant flows through solenoid valve X19 and re-enters the dual-mode phase-change energy storage device 10, completing a loop.

[0063] Based on the above embodiment, as a preferred embodiment of the control method for the thermal management system of a hydrogen fuel cell vehicle, the winter defrost control mode: based on the winter heat release control mode, solenoid valve XIII 26 and solenoid valve XIV 28 are opened. After absorbing heat and heating from the dual-mode phase change energy storage device 10, the refrigerant passes through solenoid valve XIII 26, then passes through the second evaporator 27 to defrost the second evaporator 27, and then flows through solenoid valve XIV 28 back to the dual-mode phase change energy storage device 10, completing the circuit and achieving parallel operation of heating and defrosting.

[0064] On the basis of the above embodiment, as a preferred embodiment of the control method of the thermal management system of a hydrogen fuel cell vehicle, the summer cooling control mode is as follows: under the starting condition of the fuel cell 8, the solenoid valve I2, the solenoid valve II4, the solenoid valve III6, the expansion valve 17, the solenoid valve IX16, the solenoid valve XVI29, the pump I3, and the solenoid valve IV7 are opened, and the lithium battery 12 provides power for the compressor 11. The compressor 11 compresses the carbon dioxide refrigerant to increase its pressure and temperature. A part of it is heat-exchanged through the gas cooler 5, and a part of it enters the heat exchanger I1 to transfer the heat to the ethylene glycol, and the ethylene glycol is used to preheat the fuel cell 8 so that it can quickly reach the fuel temperature. At the battery operating temperature, the low-temperature, high-pressure refrigerant, after heat exchange through gas cooler 5 and heat exchanger I1, is split into two paths: one as the primary fluid entering ejector 18, and the other as the low-temperature, low-pressure refrigerant after passing through expansion valve 17 and entering first evaporator 27. After absorbing heat in first evaporator 27, the refrigerant enters ejector 18 as the secondary fluid. The two fluids entering ejector 18 are mixed in the ejector mixing chamber, decelerated and pressurized in the diffusion chamber, and then enter second evaporator 20, absorbing waste heat from the fuel cell and ambient heat. The low-pressure refrigerant exiting second evaporator 20 enters compressor 11, forming the refrigeration circuit of the heat pump air conditioner and completing the refrigeration cycle. After the fuel cell is started, solenoid valve I2, pump I3, and solenoid valve IV7 are closed, while solenoid valve VII14, pump III21, pump 31, and solenoid valve XVI30 are opened.

[0065] Based on the above embodiment, as a preferred embodiment of the control method for the thermal management system of a hydrogen fuel cell vehicle, the summer cold storage control mode is as follows: Based on the summer cooling control mode, pump IV24, solenoid valve XII25, and solenoid valve XIV28 are opened. The low-temperature, high-pressure refrigerant from the gas cooler 5 enters the expansion valve 17, forming a low-temperature, low-pressure refrigerant, which is then split into two paths: one path enters the first evaporator 27, and the other path enters the bimodal phase-change energy storage device 10. The bimodal phase-change energy storage device 10 absorbs the cold energy from the low-temperature, low-pressure refrigerant. After entering the first evaporator 27, the low-temperature, low-pressure refrigerant merges with the refrigerant that has passed through the bimodal phase-change energy storage device 10 and enters the refrigeration circuit.

[0066] Based on the above embodiment, as a preferred embodiment of the control method for the thermal management system of a hydrogen fuel cell vehicle, the summer cooling control mode is as follows: when the hydrogen fuel cell vehicle is in the braking and parking state, pump IV24, solenoid valve XII25, and solenoid valve XIV28 are turned on. Low-temperature, low-pressure liquid refrigerant enters the dual-mode phase-change energy storage device 10 via pump IV to absorb cold energy, passes through the first evaporator 27 to absorb heat from the environment, enters solenoid valve XIV28, and finally returns to the dual-mode phase-change energy storage device 10, completing a loop.

[0067] Thus far, various embodiments of the present invention have been described in detail. To avoid obscuring the core inventive concept of the present invention, some details well known in the art have been omitted. Based on the above description, those skilled in the art will fully understand how to implement the technical solutions disclosed in the above embodiments.

[0068] Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art will understand that the above examples are for illustration only and are not intended to limit the scope of the present invention. Those skilled in the art will understand that the above embodiments may be modified or some technical features may be replaced with equivalents without departing from the scope and spirit of the present invention. In particular, as long as there is no conflict of principle, the various technical features mentioned in the various embodiments may be combined in any manner.

Claims

1. A hydrogen fuel cell vehicle thermal management system, characterized by: It includes a transcritical carbon dioxide heat pump system having a dual heat source heat exchanger group, a dual-mode phase change energy storage device (10), and a fuel cell (8); The transcritical carbon dioxide heat pump system: during the start-up process of the fuel cell (8) in winter and summer, the fuel cell is preheated through the stack preheating circuit; after the fuel cell (8) is started, the heat of the fuel cell (8) is absorbed through the stack waste heat circuit; in winter parking and defrosting conditions, the heat of the dual-mode phase change energy storage device (10) is absorbed through the heat release circuit; in defrosting conditions, the heat of the dual-mode phase change energy storage device (10) is absorbed through the defrosting circuit; in summer parking conditions, the cooling capacity of the dual-mode phase change energy storage device (10) is absorbed through the cooling release circuit; The dual-mode phase change energy storage device (10) absorbs heat from the fuel cell (8) through a heat storage loop in winter, and absorbs cold energy from the transcritical carbon dioxide heat pump system through a cold storage loop in summer; The control system controls the on and off of each circuit and the circulation and transportation of the medium.

2. The hydrogen fuel cell vehicle thermal management system according to claim 1, characterized in that: The transcritical carbon dioxide heat pump system comprises a compressor (11), a solenoid valve III (6), a gas cooler (5), a solenoid valve II (4), an ejector (18), and a second evaporator (20) which are cyclically connected in sequence. A branch is provided between the secondary fluid inlet and the primary fluid inlet of the ejector (18), and an expansion valve (17), a solenoid valve IX (16), a first evaporator (27), and a solenoid valve XV (29) are provided in sequence on the branch.

3. The hydrogen fuel cell vehicle thermal management system according to claim 2, characterized in that: The stack preheating circuit includes a heat exchanger I (1) circulatedly connected to the fuel cell (8) through a heat release circuit 1, and a pump I (3) and a solenoid valve IV (7) are provided on the heat release circuit 1; the heat exchanger I (1) is circulatedly connected to the upstream and downstream of the gas cooler (5) through a heat absorption circuit 1, and a solenoid valve I (2) is provided on the heat absorption circuit 1.

4. The hydrogen fuel cell vehicle thermal management system according to claim 2 or 3, characterized in that: The stack waste heat circuit includes a heat exchanger II (23) connected to the fuel cell (8) through a heat absorption circuit II, and a solenoid valve VII (14) and a pump III (21) are provided on the heat absorption circuit II. The heat exchanger II (23) is connected to the second evaporator (20) through a heat release circuit II, and a solenoid valve XVI (30) and a pump V (31) are provided on the heat release circuit II.

5. The hydrogen fuel cell vehicle thermal management system according to claim 4, characterized in that: The heat storage circuit is connected to the heat absorption circuit 2 through the solenoid valve V (9) and the solenoid valve XI (22); the heat release circuit is cyclically connected between the dual-mode phase change energy storage device (10) and the gas cooler (5), and the solenoid valve VI (13), the pump II (15), and the solenoid valve X (19) are provided on the heat release pipeline.

6. The hydrogen fuel cell vehicle thermal management system according to any one of claims 2, 3, and 5, characterized in that: The defrost circuit comprises a solenoid valve XIII (26) connected between the heat release circuit and the first evaporator (27), and a solenoid valve XIV (28) connected between the first evaporator (27) and the dual-mode phase change energy storage device (10).

7. The hydrogen fuel cell vehicle thermal management system according to any one of claims 2, 3, and 5, characterized in that: The cold storage circuit comprises a branch pipe 1 connected between the expansion valve (17) and the first evaporator (27), and a branch pipe 2 connected between the ejector (18) and the first evaporator (27). The branch pipe 1 and the branch pipe 2 are cyclically connected via a dual-mode phase change energy storage device (10). A pump IV (24), a solenoid valve XII (25), and a solenoid valve XIV (28) are provided on the cold storage circuit. The cold release circuit has the same structure as the cold storage circuit.

8. A method for controlling a thermal management system of a hydrogen fuel cell vehicle, characterized in that: The hydrogen fuel cell vehicle thermal management system according to claim 7 includes a winter heating control mode, a winter heat storage control mode, a winter heat release control mode, a winter defrost control mode, a summer cooling control mode, a summer cold storage control mode, and a summer cold release control mode.

9. The method for controlling a thermal management system of a hydrogen fuel cell vehicle according to claim 8, wherein: The winter heating control mode is the same as the summer cooling control mode: under the starting condition of the fuel cell (8), the solenoid valve I (2), the solenoid valve II (4), the solenoid valve III (6), the solenoid valve IV (7), the solenoid valve IX (16), the solenoid valve XV (29), the expansion valve (17), and the pump I (3) are opened; after the fuel cell (8) is started, the solenoid valve I (2), the pump I (3), and the solenoid valve IV (7) are closed, and the solenoid valve VII (14), the pump III (21), the pump V (31), and the solenoid valve XVI (30) are opened; The winter heat storage control mode: based on the winter heating control mode, the solenoid valve V (9) and the solenoid valve XI (22) are opened; The winter heat release control mode: in the braking and parking condition or the defrosting condition of the hydrogen fuel cell vehicle, the solenoid valve VI (13), the solenoid valve X (19), and the pump II (15) are opened; The winter defrosting control mode: based on the winter heat release control mode, the solenoid valve XIII (26) and the solenoid valve XIV (28) are opened.

10. The method for controlling a thermal management system of a hydrogen fuel cell vehicle according to claim 8 or 9, characterized in that: The summer cold storage control mode: based on the summer cooling control mode, the pump IV (24), the solenoid valve XII (25), and the solenoid valve XIV (28) are turned on; The summer cooling control mode: in the braking and parking condition of the hydrogen fuel cell vehicle, the pump IV (24), the solenoid valve XII (25), and the solenoid valve XIV (28) are turned on.

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