A thermal management system for a fuel cell vehicle

Abstract

The application provides a heat management system for a fuel cell vehicle, comprising a stack cooling unit, a power battery heat dissipation unit, a vehicle heating unit and an energy storage unit, the energy storage unit comprises an insulation box, a third heat exchanger and a heater are installed in the insulation box, the heater is connected with a solar cell panel, and the water inlet end and the water outlet end of a stack cooling water pipe are connected to the insulation box; the energy storage unit further comprises the third heat exchanger, an energy storage water circulating pump, a fourth heat exchanger, a three-way valve and the first heat exchanger which are connected into a loop through pipelines in sequence, and the third interface of the three-way valve is connected to the water inlet end of the third heat exchanger. The application utilizes the heat of the stack cooling unit, the power battery heat dissipation unit and the vehicle heating unit, and improves the energy utilization rate of the system. The energy storage unit is added, and the problems of high energy consumption of fuel cell rapid starting, power battery insulation and vehicle heating at low temperature are solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of fuel cell vehicles, and particularly relates to a thermal management system for a fuel cell vehicle. BACKGROUND

[0002] New energy vehicles represented by fuel cell vehicles have advantages of energy saving and environmental protection, and have rapidly developed in recent years and have good application prospects, but compared with traditional internal combustion engine vehicles, fuel cell vehicles face greater challenges in thermal management.

[0003] When a fuel cell is started at low temperature, especially when the ambient temperature is below 0℃, the heat generated by the chemical reaction of the fuel cell itself is low, and the generated water is prone to icing, thereby causing the start-up to fail. Raising the temperature of the stack to above 0℃ before starting can improve the probability of successful start-up, and then using the heat generated by the chemical reaction to raise the temperature of the stack to the required temperature. Raising the temperature of the stack before starting to meet the requirements of the stack can shorten the cold start time of the stack. At present, the low-temperature cold start of the fuel cell is mostly achieved by PTC heating or controlling the operating conditions of the stack to use the heat generated by the chemical reaction. Using PTC heating consumes the electrical energy stored in the power battery, and at the same time is limited by the heating power of the PTC, and the start-up time is long; controlling the operating conditions of the stack to use the heat generated by the chemical reaction requires high requirements, is difficult to control, and also has the problem of long start-up time.

[0004] The power battery carried by the fuel cell vehicle is mostly a lithium battery, and the suitable working temperature of the lithium battery is between 20-30℃, and too high or too low temperature will also cause the performance of the lithium battery to decay or even be damaged, and the lithium battery needs to be heated when the temperature is low, and the lithium battery needs to be cooled when the temperature is high. The heating of the lithium battery at low temperature is mostly achieved by PTC heating, and the use of PTC also consumes the electrical energy stored in the power battery.

[0005] When a vehicle carrying a fuel cell is used at low temperature, in order to improve the driving comfort of the personnel in the cabin, the cabin needs to be heated by using warm air to make the cabin reach an ambient temperature that is comfortable for the driver and passengers. At the same time, when the vehicle is used at low temperature, high air humidity or low temperature and rainy weather, the windshield of the vehicle is frosted, and in order to improve the safety of driving, the windshield needs to be defrosted by using warm air to keep the driver's field of vision clear. The energy of these warm air ultimately comes from the chemical reaction of hydrogen and oxygen or the energy stored in the power battery, and the warm air is a part that consumes a lot of energy, and when the warm air is used, it is hoped that the energy consumption can be reduced as much as possible to ultimately reduce the fuel consumption of the vehicle and improve the cruising range of the vehicle.

[0006] With the increase of fuel cell power, the heat dissipation area requirement of the radiator is also increasing. Due to the fact that the space of the vehicle is already very tight, this causes great difficulty in layout, especially when the stack outputs at peak power at high ambient temperature, which occurs for a short time but requires high heat dissipation. In order to meet the demand for peak power output, a heat exchanger with large heat exchange capacity is required, resulting in waste of heat dissipation capacity and layout space in most cases.

[0007] In summary, the existing fuel cell vehicle thermal management system relies on PTC heating for fuel cell rapid start-up at low temperature, power battery heat preservation, and vehicle heating, which has the problems of slow start-up at low temperature and high power battery energy consumption, and it is difficult to solve the above problems on the basis of reducing power battery energy consumption. SUMMARY

[0008] The present application is directed to the above technical problems, and proposes a thermal management system with an energy storage unit and comprehensive utilization of heat from the stack cooling unit, power battery heat dissipation unit, and vehicle heating unit.

[0009] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0010] A thermal management system for a fuel cell vehicle, comprising a stack cooling unit, a power battery heat dissipation unit, a vehicle heating unit, and an energy storage unit, the stack cooling unit comprising a fuel cell stack, the fuel cell stack being connected to a stack cooling circulating water pump, a thermostat, and a main radiator through a stack cooling water pipe, and an expansion tank being further provided between the main radiator and the stack;

[0011] The power battery heat dissipation unit comprises a power battery, a battery heat dissipation circulating water pump, a first heat exchanger, and a second heat exchanger connected in a loop through a battery heat dissipation water pipe;

[0012] The vehicle heating unit comprises a condenser, a first expansion and stop combination valve, an evaporator, and an air conditioning compressor connected in a loop through a pipeline in sequence, and a heater core, a heater core circulating water pump, and a fourth heat exchanger connected in a loop in sequence, the evaporator and the heater core being in contact;

[0013] The condenser is connected to the second heat exchanger through a second expansion and stop combination valve, and the second heat exchanger is connected to the liquid inlet end of the air conditioning compressor;

[0014] The energy storage unit comprises an insulation box, a third heat exchanger, and a heater installed in the insulation box, the heater being connected to a solar cell panel, the water inlet end and the water outlet end of the stack cooling water pipe being connected to the insulation box; the energy storage unit further comprises a third heat exchanger, an energy storage water circulating water pump, a fourth heat exchanger, a three-way valve, and a first heat exchanger connected in a loop through a pipeline in sequence, and the third interface of the three-way valve being connected to the water inlet end of the third heat exchanger.

[0015] As preferred, the water outlet end of the stack cooling water pipe is provided with a stack water outlet temperature sensor, and the water inlet end is provided with a stack water inlet temperature sensor.

[0016] As preferred, a proportional valve is arranged on the pipeline between the water inlet end of the stack cooling water pipe and the heat preservation box.

[0017] As preferred, the water outlet end of the condenser is connected to the water inlet end of the second heat exchanger through an expansion and stop combination valve, and the water outlet end of the second heat exchanger is connected to the water inlet end of the air conditioner compressor.

[0018] As preferred, a water storage spraying unit is further included, which comprises a water storage device and an electrically controlled spraying head, and the water storage device is connected to the fuel cell.

[0019] As preferred, a liquid level switch is installed in the water storage device.

[0020] As preferred, an air blower is arranged on one side of the warm air heat exchanger.

[0021] As preferred, the energy storage unit further comprises an energy storage water temperature sensor for detecting the water temperature in the heat preservation box.

[0022] Compared with the prior art, the application has the advantages and positive effects that:

[0023] 1. The heat management system for the fuel cell vehicle comprises a stack cooling unit, a power battery heat dissipation unit, a vehicle heating unit and an energy storage unit, and energy exchange can be carried out among the units, the heat of each unit is fully utilized, and the capacity utilization rate of the system is improved.

[0024] 2. The energy storage unit is added to store the heat generated by the chemical reaction of the fuel cell in a low temperature environment, and the energy storage unit is maintained at a certain temperature by the power generation and heating of the solar panel when the fuel cell does not work.

[0025] 3. When the stack is started at a low temperature, the high temperature cooling liquid stored in the energy storage unit is used to heat the stack, the energy loss caused by the heating of the stack by the PTC is avoided, the heating rate is fast, and the low temperature starting time is shortened.

[0026] 4. When working in a low temperature environment, the heat generated by the chemical reaction of the fuel cell is used to heat the power battery through internal heat exchange of the energy storage unit, so that the power battery reaches a suitable working temperature, and the energy loss caused by the heating of the power battery by the PTC is avoided.

[0027] 5. When the fuel cell operates in a high-temperature environment and at peak power, it utilizes the vehicle's air conditioning system for cooling and heat exchange through the heat exchanger and energy storage unit to lower the temperature of the coolant stored inside the energy storage unit, thereby providing cooling for the fuel cell system and avoiding waste caused by excessive design margin of the fuel cell main radiator.

[0028] 6. A water storage and spraying unit is installed to collect the water produced by the chemical reaction of the fuel cell. As needed, the collected water is sprayed onto the outer surface of the heat exchanger to clean it, which reduces the fouling loss of the heat exchanger, improves the heat exchange efficiency, and avoids the waste of water resources. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the thermal management system of the present invention;

[0030] In the above diagrams: a) Fuel cell stack cooling unit; b) Power battery heat dissipation unit; c) Vehicle heating unit; d) Water storage spray unit; 1) Fuel cell; 2) Fuel cell stack outlet water temperature sensor; 3) Fuel cell stack cooling circulating water pump; 4) Electronic thermostat; 5) Expansion tank; 6) Main radiator; 7) Fuel cell stack inlet water temperature sensor; 8) Proportional valve; 9) Energy storage unit; 901) Insulation box; 902) Solar panel; 903) Heater; 904) Third heat exchanger; 905) Energy storage water temperature sensor; 10) Energy storage water. 11. Circulating water pump; 12. Fourth heat exchanger; 13. Warm air heat exchanger; 14. Blower; 15. Warm air circulating water pump; 16. Three-way valve; 17. Power battery; 18. Battery cooling circulating water pump; 19. First heat exchanger; 20. Air conditioning compressor; 21. Condenser; 22. Second expansion and shut-off combination valve; 23. Second heat exchanger; 24. First expansion and shut-off combination valve; 25. Evaporator; 26. Water storage tank; 27. Electrically controlled nozzle; 28. Fuel cell stack cooling water pipe; 2701. Water inlet; 2702. Water outlet. Detailed Implementation

[0031] To better understand the present invention, the following detailed description is provided in conjunction with the accompanying drawings and embodiments.

[0032] Example: Figure 1 As shown, a thermal management system for a fuel cell vehicle includes a stack cooling unit a, a power battery heat dissipation unit b, a vehicle heating unit c, an energy storage unit 9, and a controller.

[0033] The stack cooling unit a includes a fuel cell stack, the fuel cell stack includes a plurality of fuel cell monomers and a cooling circuit for cooling the fuel cell stack. The fuel cell 1 stack is sequentially connected with a stack cooling circulating water pump 3, a thermostat and a main radiator 6 from a water outlet end 2702 to a water inlet end 2701 through a stack cooling water pipe 27. The third interface of the thermostat is connected to the water outlet end 2702. The main radiator 6 has a water inlet chamber, a water outlet chamber and a central heat exchange core. The water inlet chamber is connected with a cooling liquid inlet pipe, and the water outlet chamber is connected with a cooling liquid outlet pipe and a cooling system exhaust pipe. The main radiator 6 is provided with a speed-controllable electronic fan, and the electronic fan provides external air participating in the heat exchange of the radiator. An expansion tank 5 is further arranged between the main radiator 6 and the stack, the expansion tank 5 exchanges the gas in the cooling circuit to the upper space thereof, simultaneously supplements the cooling liquid into the stack cooling unit a, stabilizes the operating pressure of the cooling system, and provides a filling port of the cooling liquid in the stack cooling unit a.

[0034] The water outlet end 2702 of the stack cooling water pipe 27 is provided with a stack outlet temperature sensor 2, and the stack outlet temperature sensor 2 collects the temperature of the cooling liquid at the stack outlet position. The water inlet end 2701 of the stack cooling water pipe 27 is provided with a stack inlet temperature sensor 7, and the stack inlet temperature sensor 7 collects the temperature of the cooling liquid at the stack cooling circuit inlet position. The stack outlet temperature sensor 2 and the stack inlet temperature sensor 7 are electrically connected with a controller. When the stack inlet temperature sensor 7 detects that the temperature of the cooling liquid is low, the controller makes the electronic thermostat 4 small circulation channel conductive according to the system requirement. When the temperature of the cooling liquid is high, the large circulation channel is made conductive through the rotation of the valve, and whether the cooling liquid passes through the cooling liquid channel of the main radiator 6 is controlled through the rotation of the valve.

[0035] The power battery cooling unit b includes a power battery 16, a battery cooling circulating water pump 17, a first heat exchanger 18 and a second heat exchanger 22 connected through a battery cooling water pipe. The second heat exchanger 22 is connected to the power battery 16 to form a cooling circuit. The first heat exchanger 18 and the second heat exchanger 22 are both plate heat exchangers, and the two parts separated in the plate heat exchanger exchange heat through the fluids flowing in the two parts.

[0036] The vehicle heating unit c includes a condenser 20, a first expansion and shut-off combination valve 23, an evaporator 24, and an air conditioning compressor 19, connected in sequence via pipes to form an air conditioning refrigerant circulation loop. It also includes a heater heat exchanger 12, a heater circulating water pump 14, and a fourth heat exchanger 11, connected in sequence via pipes. The evaporator 24 is in contact with the heater heat exchanger 12, and a blower 13 is installed on one side of the heater heat exchanger 12. The heater heat exchanger 12 has a central heat exchange core with water chambers at both ends, and coolant inlets and outlets on the water chambers. The blower 13 provides external air for heat exchange in the heater heat exchanger 12, providing the power for external air circulation, and delivering the heated air into the driver's cab for heating or to the windshield for defrosting. The condenser 20 is connected to the second heat exchanger 22 via the second expansion and shut-off combination valve 21, and the second heat exchanger 22 is connected to the liquid inlet of the air conditioning compressor 19; the second expansion and shut-off combination valve 21 controls the flow rate of refrigerant through this branch.

[0037] The energy storage unit 9 includes an insulated box 901, inside which a third heat exchanger 904 and a heater 903 are installed. The heater 903 is connected to a solar panel 902, which provides electrical energy to heat the coolant inside the insulated box 901. The insulated box 901 has three layers: an inner sealed stainless steel plate made of 316L stainless steel, a middle insulation layer, and an outer waterproof stainless steel layer. The third heat exchanger 904 is a tube bundle heat exchanger that exchanges heat between the liquid stored inside the insulated box 901 and the battery heating unit and the vehicle heating unit c. The inlet 2701 and outlet 2702 of the fuel cell stack cooling water pipe 27 are both connected to the insulation box 901. A proportional valve 8 is installed on the pipeline between the inlet 2701 and the insulation box 901. The proportional valve 8 is electrically connected to the controller. When necessary, the coolant in the insulation box 901 is introduced into the fuel cell cooling unit. The proportional valve 8 adjusts the flow rate of the coolant through this branch by rotating a ball valve. An energy storage water temperature sensor 905 is installed on the insulation box 901 to detect the water temperature inside the insulation box 901. The energy storage water temperature sensor 905 is electrically connected to the controller.

[0038] The energy storage unit 9 also includes a third heat exchanger 904, an energy storage water circulation pump 10, a fourth heat exchanger 11, a three-way valve 15, and a first heat exchanger 18, which are connected in sequence via pipelines to form a loop. The third port of the three-way valve 15 is connected to the water inlet of the third heat exchanger 904. The third heat exchanger 904 is a tube bundle type heat exchanger, which exchanges heat between the liquid stored inside the insulation box 901 and the battery heating unit and the vehicle heating unit c. The fourth heat exchanger 11 realizes the heat exchange between the energy storage unit 9 and the vehicle heating unit c, and the first heat exchanger 18 realizes the heat exchange between the energy storage unit 9 and the battery heating unit.

[0039] The outlet of the condenser 20 is connected to the inlet of the second heat exchanger 22 via an expansion and shut-off combination valve. The outlet of the second heat exchanger 22 is connected to the inlet of the air conditioning compressor 19. The second heat exchanger 22 enables heat exchange between the heating unit and the battery heating unit.

[0040] It also includes a water storage and spraying unit d, which comprises a water storage tank 25 and an electrically controlled nozzle 26. The water storage tank 25 is connected to the fuel cell 1. The water storage tank 25 consists of a stainless steel plate housing and a liquid level switch. The electrically controlled nozzle 26 sprays the liquid water stored in the water storage unit onto the heat exchanger as needed to clean the heat exchanger.

[0041] The working principle and operation process of the thermal management system used in fuel cell vehicles are as follows:

[0042] When the ambient temperature is low, after the fuel cell starts up and reaches the required stack temperature, if the temperature collected by the energy storage water temperature sensor 905 on the energy storage unit 9 is lower than the temperature collected by the stack inlet water temperature sensor 7, the controller controls the proportional valve 8 to open, allowing coolant to enter the energy storage unit 9 and raising the temperature of the coolant in the insulation box 901 until the temperature of the coolant inside the energy storage unit 9 matches the stack inlet temperature. When the stack stops, the energy storage unit 9 loses less energy due to the insulation effect of the insulation box 901. Furthermore, the solar panel 902 converts solar energy into electrical energy to supply the heater 903, which heats the coolant in the insulation box 901, maintaining a constant and relatively high temperature for the coolant inside the storage unit.

[0043] During a low-temperature cold start, the electronic thermostat 4 controls the small circulation channel to be open via a valve, while the large circulation branch is closed. At this time, the coolant does not flow through the main radiator 6 of the fuel cell 1 for heat dissipation. The proportional valve 8 gradually opens, and under the action of the stack cooling circulating water pump 3, the high-temperature coolant inside the storage unit gradually enters the fuel cell 1, causing the fuel cell 1 to heat up. When the temperature meets the requirements for low-temperature cold start, the fuel cell starts up under low-temperature cold start conditions.

[0044] After the fuel cell stack is started up, the stack continues to heat up by the heat generated by the chemical reaction of the fuel inside the fuel cell 1. In order to avoid the problem that the heat absorption of the coolant inside the energy storage unit 9 will slow down the heating rate of the fuel cell stack, the proportional valve 8 is closed.

[0045] After the proportional valve 8 is closed, the three-way valve 15 controls the passage through the first heat exchanger 18 to be open. Under the power of the energy storage water circulation pump 10, the coolant inside the passage flows through the third heat exchanger 904 and exchanges heat with the coolant inside the energy storage unit 9. The coolant is heated and flows through the energy storage water circulation pump 10, through the fourth heat exchanger 11, the three-way valve 15 and the third heat exchanger 904 before flowing back to the third heat exchanger 904.

[0046] Meanwhile, under the action of the battery cooling circulating water pump 17, the coolant inside the battery heating unit flows through the power battery 16, and after passing through the first heat exchanger 18 and the second heat exchanger 22, it flows back to the power battery 16. Heat exchange occurs between the two fluids inside the first heat exchanger 18, heating the coolant flowing inside the battery heating unit. The heated coolant then flows through the cooling channels inside the power battery 16 to preheat it.

[0047] The waste heat generated by the chemical reaction of fuel cell 1 continuously raises the temperature of the stack. Once a certain temperature is reached, the controller controls the proportional valve 8 to open, and the coolant inside the energy storage unit 9 heats up. Through the flow and heat exchange of the coolant on both sides inside the first heat exchanger 18, the power battery 16 is heated to its appropriate operating temperature. The three-way valve 15 controls the coolant to no longer pass through the first heat exchanger 18.

[0048] When it is necessary to defrost the windshield or provide heating to the cab, the coolant inside the heating water pump 14 flows through the fourth heat exchanger 11 under the action of the heating water pump 14. After heat exchange and heating in the fourth heat exchanger 11, the coolant flows into the heating heat exchanger 12. Under the action of the blower 13, the cold air outside flows through the heating heat exchanger 12 and is heated before flowing into the cab to provide heating or to defrost the windshield.

[0049] When the ambient temperature is high, the gaseous refrigerant is compressed into a high-pressure gas by the air conditioning compressor 19. The high-pressure refrigerant gas flows through the condenser 20 and dissipates heat, becoming a low-temperature liquid. The refrigerant liquid flowing out of the condenser 20 flows through the expansion and shut-off combination valve, and after throttling, flows into the evaporator 24. The external gas flows into the evaporator 24 by the blower 13. Inside the evaporator 24, the refrigerant absorbs heat, cooling the external air. The cooled air enters the cab to provide cold air for the driver.

[0050] Meanwhile, the liquid refrigerant flowing out of the condenser 20 flows into the expansion and shut-off combination valve, then enters the second heat exchanger 22 and becomes gaseous refrigerant to absorb heat, before flowing back to the air conditioning compressor 19. The coolant from the battery heating unit flows through the second heat exchanger 22, where its temperature decreases, and then flows into the power battery 16 to cool it down.

[0051] The cryogenic coolant from the battery heating unit flows through the first heat exchanger 18, while the coolant inside the third heat exchanger 904 flows through another channel of the first heat exchanger 18 for cooling. The controller controls the operation of the energy storage water circulation pump 10, causing the coolant cooled by the first heat exchanger 18 to flow through the tube bundle heat exchanger, lowering the coolant temperature inside the energy storage unit 9 to match the ambient temperature. When the fuel cell operates at peak power, the proportional valve 88 gradually opens, injecting the internal cryogenic coolant into the stack circulation system to cool the stack and meet the heat dissipation requirements under peak power.

[0052] The chemical reaction of fuel cell 1 produces water, which is discharged at the tail end of the stack. The water storage unit d's water storage tank 25 collects this discharged water. The water storage tank 25 is also equipped with a level switch. When the liquid inside the water storage tank 25 reaches a certain height, the level switch is turned on to supply power to the electronically controlled nozzle 26, which sprays the water stored inside the water storage tank 25 onto the outer surface of the heat exchanger to clean the heat exchanger, remove dust from the surface of the heat exchanger, avoid the impact of dust on the heat exchanger's performance, reduce the fouling loss of the heat exchanger, and improve the heat exchange performance of the heat exchanger.

[0053] The thermal management system for fuel cell vehicles described in this embodiment includes a stack cooling unit a, a power battery heat dissipation unit b, a vehicle heating unit c, and an energy storage unit 9. The units can exchange energy with each other, fully coordinate and utilize the heat of each unit, and improve the energy utilization rate of the system.

[0054] An energy storage unit 9 is added to store the heat generated by the chemical reaction of the fuel cell in low-temperature environments. When the fuel cell is not operating, the energy storage unit 9 is heated by solar power generated by solar panels 902 to maintain a certain temperature. During low-temperature cold starts, the high-temperature coolant stored in the energy storage unit 9 heats the fuel cell stack, avoiding the energy loss caused by the PTC consuming electrical energy to heat the stack. Furthermore, the heating rate is fast, shortening the low-temperature cold start time. When operating in low-temperature environments, the heat generated by the chemical reaction of the fuel cell is used for heat exchange within the energy storage unit 9 to heat the power battery, bringing it to a suitable operating temperature, thus avoiding the energy loss caused by the PTC consuming electrical energy to heat the power battery.

[0055] When the fuel cell operates in a high-temperature environment and at peak power, it utilizes the vehicle's air conditioning system for cooling and heat exchange through the heat exchanger and energy storage unit to lower the temperature of the coolant stored inside the energy storage unit 9, thereby providing cooling for the fuel cell system and avoiding waste caused by excessive design margin of the fuel cell main radiator.

[0056] A water storage spray unit d is set up to collect the water produced by the chemical reaction of the fuel cell. As needed, the collected water is sprayed onto the outer surface of the heat exchanger to clean the heat exchanger, which reduces the fouling loss of the heat exchanger, improves the heat exchange efficiency of the heat exchanger, and avoids the waste of water resources.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A thermal management system for fuel cell vehicles, characterized in that: It includes a fuel cell stack cooling unit, a power battery heat dissipation unit, a vehicle heating unit, and an energy storage unit. The fuel cell stack cooling unit includes a fuel cell stack. A fuel cell stack cooling circulating water pump, a thermostat, and a main radiator are connected to the fuel cell stack via fuel cell stack cooling water pipes. An expansion tank is also provided between the main radiator and the fuel cell stack. The power battery cooling unit includes a power battery connected in a loop via a battery cooling water pipe, a battery cooling circulating water pump, a first heat exchanger, and a second heat exchanger. The vehicle heating unit includes a condenser, a first expansion and shut-off combination valve, an evaporator and an air conditioning compressor connected in sequence via pipelines, as well as a heater heat exchanger, a heater circulating water pump and a fourth heat exchanger connected in sequence, with the evaporator and the heater heat exchanger in contact. The condenser is connected to the second heat exchanger via a second expansion and shut-off combination valve, and the second heat exchanger is connected to the liquid inlet of the air conditioning compressor. The energy storage unit includes an insulated box, inside which a third heat exchanger and a heater are installed. The heater is connected to the solar panel, and the inlet and outlet of the fuel cell stack cooling water pipe are both connected to the insulated box. The energy storage unit also includes a third heat exchanger, an energy storage water circulation pump, a fourth heat exchanger, a three-way valve, and a first heat exchanger, which are connected in sequence through pipelines to form a loop. The third port of the three-way valve is connected to the inlet of the third heat exchanger. When the fuel cell stack is cold-started at low temperatures, the high-temperature coolant stored in the energy storage unit is used to heat the stack. When operating in a low-temperature environment, the heat generated by the chemical reaction of the fuel cell is used in the energy storage unit to heat the power battery. When the fuel cell is operating in a high-temperature environment and at peak power, the vehicle's air conditioning system is used for cooling and heat exchange is conducted with the energy storage unit through a heat exchanger to lower the temperature of the coolant stored in the energy storage unit, thereby cooling the fuel cell stack.

2. The thermal management system for fuel cell vehicles according to claim 1, characterized in that: The outlet end of the fuel cell stack cooling water pipe is equipped with a fuel cell stack outlet water temperature sensor, and the inlet end is equipped with a fuel cell stack inlet water temperature sensor.

3. The thermal management system for fuel cell vehicles according to claim 1, characterized in that: A proportional valve is installed on the pipeline between the inlet end of the fuel cell stack cooling water pipe and the insulation box.

4. The thermal management system for fuel cell vehicles according to claim 1, characterized in that: The outlet of the condenser is connected to the inlet of the second heat exchanger via an expansion and shut-off combination valve, and the outlet of the second heat exchanger is connected to the inlet of the air conditioning compressor.

5. The thermal management system for fuel cell vehicles according to claim 1, characterized in that: It also includes a water storage spray unit, which includes a water tank and an electronically controlled spray head, with the water tank connected to the fuel cell.

6. The thermal management system for fuel cell vehicles according to claim 5, characterized in that: The water storage device is equipped with a level switch.

7. The thermal management system for fuel cell vehicles according to claim 1, characterized in that: A blower is installed on one side of the heating air heat exchanger.

8. The thermal management system for fuel cell vehicles according to claim 1, characterized in that: The energy storage unit also includes an energy storage water temperature sensor for detecting the water temperature inside the insulation box.

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