Fuel cell vehicle thermal management system and control method thereof

Abstract

The invention provides a fuel cell vehicle heat management system and a control method thereof, and the system comprises a fuel cell circulating water path, a fuel cell cathode system and an air conditioner refrigerating and heating loop, an electric pile, an electronic temperature control valve, a first radiator fan assembly, a second electronic three-way valve, a first plate heat exchanger, a first electronic three-way valve and an electric pile water pump are sequentially arranged on the fuel cell circulating water path, and a deionizer and a first PTC heater are arranged on a pipeline between a water outlet of the electric pile water pump and a water outlet of the electric pile in series; a communicating pipeline is arranged between an upper water outlet of the electronic temperature control valve and a water outlet of the first electronic three-way valve; the fuel cell circulating water path exchanges heat with an air conditioner refrigerating and heating loop through a first plate heat exchanger; the fuel cell cathode system comprises an air compressor, an intercooler, a back pressure valve and a bypass valve. The waste heat of the air compressor can be fully utilized, the energy utilization rate is increased, the system structure is simplified, and the energy consumption of the vehicle is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy vehicles, and in particular relates to a thermal management system for a fuel cell vehicle and a control method thereof. Background Art

[0002] The heat generated by fuel cells is mainly the energy that is not converted into electrical energy during the electrochemical reaction of the fuel cell but is dissipated in the form of heat through the medium. This part of the dissipated heat mainly includes three parts: ohmic heat, activation heat, and reaction heat. The heat dissipation of the fuel cell system is very large. If this part of the heat is recycled and utilized, it can not only reduce the difficulty of heat dissipation, but also greatly improve the energy utilization rate of the system. Therefore, the comprehensive utilization of thermal energy is of great significance to the power system of fuel cell vehicles.

[0003] In the prior art, only the waste heat of the battery stack is generally recycled, which makes the energy utilization rate of the thermal management system low and the energy consumption of the whole vehicle high. Therefore, how to design a thermal management system for fuel cell vehicles and its control method to improve energy utilization and reduce vehicle energy consumption has become a technical problem that technicians in this field need to solve urgently. Summary of the invention

[0004] The object of the present invention is to provide a fuel cell vehicle thermal management system to solve the above technical problems in the prior art. Another object of the present invention is to provide a control method for the fuel cell vehicle thermal management system.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A fuel cell vehicle thermal management system comprises a fuel cell circulating water circuit, a fuel cell cathode system, and an air conditioning cooling and heating circuit. The fuel cell circulating water circuit is sequentially provided with a stack, an electronic temperature control valve, a first radiator fan assembly, a second electronic three-way valve, a first plate heat exchanger, a first electronic three-way valve, and a stack water pump, wherein the left water outlet of the second electronic three-way valve is connected to the lower water inlet of the first electronic three-way valve through a pipeline; a deionizer and a first PTC heater are arranged in series on the pipeline between the water outlet of the stack water pump and the water outlet of the stack, a connecting pipeline is arranged between the electronic temperature control valve and the water outlet of the first electronic three-way valve, and the first plate heat exchanger is used for heat exchange with a first evaporator in the air conditioning cooling and heating circuit; the fuel cell cathode system comprises an air compressor and an intercooler sequentially arranged on the air intake pipeline of the stack, a back pressure valve arranged on the air outlet pipeline of the stack, and a bypass valve arranged on the connecting air pipe between the air outlet of the back pressure valve and the air outlet of the intercooler.

[0007] Preferably, the bypass valve is a three-way valve, and the left air outlet of the bypass valve is connected to the bypass exhaust branch.

[0008] Preferably, it also includes a power battery circulating water circuit, on which power batteries, a battery water pump and a second plate heat exchanger are sequentially arranged, and a third electronic three-way valve is arranged on the air pipe between the air outlet of the air compressor and the air inlet of the second plate heat exchanger, and the right air outlet of the third electronic three-way valve and the air outlet of the second plate heat exchanger are respectively connected to the air inlet pipeline through air pipes.

[0009] Preferably, a Chiller heat exchanger is further provided on the power battery circulation water circuit, and the Chiller heat exchanger is located between the power battery and the battery water pump. The power battery circulation water circuit exchanges heat with the air conditioning cooling and heating circuit through the Chiller heat exchanger.

[0010] Preferably, it also includes a motor and electrical appliance circulating water circuit, on which a motor water pump, a fourth electronic three-way valve, and a four-way valve are sequentially arranged, a first branch and a second branch are arranged in parallel between the motor water pump and the fourth electronic three-way valve, a hydrogen circulation pump, an air compressor controller and an air compressor are sequentially arranged on the first branch, and a motor controller, a DCDC converter and a motor are sequentially arranged on the second branch; the left interface and the upper interface of the four-way valve are respectively connected to the water outlet of the Chiller heat exchanger and the water inlet of the battery water pump, the left water outlet of the fourth electronic three-way valve is connected to its lower water outlet through a connecting water pipe, and a second radiator fan assembly is arranged on the connecting water pipe.

[0011] Preferably, the air-conditioning cooling and heating circuit includes an air-conditioning circulation circuit, on which an air-conditioning compressor, a condenser, a stop valve, a first expansion valve and a second evaporator are sequentially arranged, and an air-conditioning branch is also arranged between the water outlet of the condenser and the water inlet of the air-conditioning compressor, and the second expansion valve and the Chiller heat exchanger are arranged in series on the air-conditioning branch.

[0012] Preferably, the air conditioning cooling and heating circuit further includes a warm air circulation circuit, and a warm air water pump, a second PTC heater, the first evaporator and the first plate heat exchanger are sequentially arranged on the warm air circulation circuit.

[0013] A control method for a fuel cell vehicle thermal management system, comprising:

[0014] When the stack outlet water temperature pressure sensor detects that the stack outlet water temperature is not greater than 0°C, the controller controls the first PTC heater to operate;

[0015] When the stack outlet water temperature pressure sensor detects that the stack outlet water temperature is greater than 0°C but not greater than 65°C, the controller turns off the first PTC heater;

[0016] When the stack outlet water temperature pressure sensor detects that the stack outlet water temperature is greater than 65°C but not greater than 90°C, the controller turns off the first PTC heater, and the electronic temperature control valve opens, and the first radiator fan assembly works, so that cooling water flows through the first radiator fan assembly.

[0017] Preferably, it also includes:

[0018] When the power battery outlet water temperature sensor detects that the power battery outlet water temperature is not greater than 0°C, the controller controls the third electronic three-way valve to operate, so that the high-temperature and high-pressure gas generated by the air compressor passes through the second plate heat exchanger to heat the cooling water in the power battery circulation water circuit;

[0019] When the power battery outlet water temperature sensor detects that the power battery outlet water temperature is greater than 0°C but less than 35°C, the controller controls the third electronic three-way valve to operate so that the high-temperature and high-pressure gas does not pass through the second plate heat exchanger; at the same time, the controller controls the four-way valve to operate so that the residual heat of the motor and electrical appliances is used to heat the cooling water in the power battery circulation water circuit;

[0020] When the power battery water outlet temperature sensor detects that the power battery water outlet temperature is greater than 35°C but not greater than 40°C, the controller controls the four-way valve and the fourth electronic three-way valve to allow the cooling water to pass through the second radiator fan assembly, and at the same time controls the second expansion valve to open to dissipate the heat of the cooling water in the power battery circulating water circuit.

[0021] Preferably, it also includes:

[0022] When the motor and electrical appliance outlet water temperature sensor detects that the motor and electrical appliance outlet water temperature is not greater than 55°C, the cooling water does not pass through the second radiator fan assembly;

[0023] When the motor and electrical appliance water outlet temperature sensor detects that the motor and electrical appliance water outlet temperature is greater than 55°C but not greater than 65°C, the controller controls the fourth electronic three-way valve to operate and simultaneously turns on the second radiator fan assembly so that cooling water passes through the second radiator fan assembly.

[0024] The beneficial effects of the present invention are:

[0025] The fuel cell vehicle thermal management system and control method of the present invention can not only recover the waste heat generated by the fuel cell vehicle's stack to improve energy utilization, but also heat the power battery through the high-temperature and high-pressure gas provided by the fuel cell air compressor when the power battery is cold-started at low temperature, thereby eliminating the heater in the existing power battery circulation water circuit and simplifying the system structure. At the same time, it can further improve the energy utilization of the thermal management system and reduce the energy consumption of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments, and further describe the specific embodiments of the present invention in detail in conjunction with the drawings, wherein

[0027] Figure 1 A schematic diagram of a fuel cell vehicle thermal management system provided in an embodiment of the present invention.

[0028] Markings in the accompanying drawings:

[0029] 1. Air compressor; 2. Intercooler; 3. Bypass valve; 4. Back pressure valve; 5. Fuel cell;

[0030] 6. Temperature and pressure sensor for water outlet of battery stack; 7. Temperature and pressure sensor for water inlet of battery stack;

[0031] 8. Deionizer; 9. Stack water pump; 10. Electronic temperature control valve;

[0032] 11. First radiator fan assembly; 12. First electronic three-way valve;

[0033] 13. Second electronic three-way valve; 14. First plate heat exchanger; 15. Gas outlet pipeline;

[0034] 16. The third electronic three-way valve; 17. The evaporation box; 18. The second evaporator;

[0035] 19. First evaporator; 20. First expansion valve; 21. Stop valve;

[0036] 22. Air conditioning compressor; 23. Second PTC heater; 24. Warm air water pump;

[0037] 25. Second expansion valve; 26. Chiller heat exchanger; 27. Power battery;

[0038] 28. Second plate heat exchanger; 29. ​​Battery water pump; 30. Four-way valve;

[0039] 31. Fourth electronic three-way valve; 32. Motor water pump; 33. Hydrogen circulation pump;

[0040] 34. Air compressor controller; 35. Air compressor; 36. Motor controller;

[0041] 37. DCDC converter; 38. Motor; 39. Second radiator fan assembly;

[0042] 40. First PTC heater; 41. Bypass exhaust branch;

[0043] A. Fuel cell cathode system; B. Fuel cell cooling system; C. Air conditioning system;

[0044] D. Power battery cooling system; E. Motor electronic control cooling system. DETAILED DESCRIPTION

[0045] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0046] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0047] 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 as part of the specification.

[0048] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0049] like Figure 1 As shown, an embodiment of the present invention provides a fuel cell vehicle thermal management system, which includes a fuel cell circulating water circuit, a fuel cell cathode system, and an air conditioning cooling and heating circuit. The fuel cell circulating water circuit is sequentially provided with a stack 5, an electronic temperature control valve 10, a first radiator fan assembly 11, a second electronic three-way valve 13, a first plate heat exchanger 14, a first electronic three-way valve 12, and a stack water pump 9. The left water outlet of the second electronic three-way valve is connected to the lower water inlet of the first electronic three-way valve through a pipeline; the pipeline between the water outlet of the stack water pump and the water outlet of the stack A deionizer 8 and a first PTC heater 40 are arranged in series, a connecting pipeline is arranged between the electronic temperature control valve 10 and the water outlet of the first electronic three-way valve, and the first plate heat exchanger 14 is used to exchange heat with the first evaporator 19 in the air conditioning refrigeration and heating circuit; the fuel cell cathode system includes an air compressor 1 and an intercooler 2 arranged in sequence on the air intake pipeline of the fuel cell stack, a back pressure valve 4 arranged on the air outlet pipeline 15 of the fuel cell stack, and a bypass valve 3 arranged on the connecting air pipe between the air outlet of the back pressure valve 4 and the air outlet of the intercooler 2.

[0050] Specifically, the bypass valve 3 is a three-way valve, and the left gas outlet of the bypass valve 3 is connected to the bypass exhaust branch 41 , so that part of the gas can flow out from the bypass exhaust branch 41 .

[0051] It is understandable that the air compressor 1 in the cathode system of the fuel cell is used to pressurize the external air. When the high-temperature and high-pressure air after pressurization passes through the intercooler 2, the intercooler transfers part of the heat in the air through heat exchange to cool the air to a suitable temperature for the operation of the fuel cell stack, and then the air enters the fuel cell stack. The bypass valve 3 can better adjust the contradiction between the effective working area of ​​the air compressor and the optimal working curve requirements of the fuel cell stack; during the start-up purge, shutdown purge or idling conditions, part of the air will flow away through the bypass valve; by adjusting the opening of the valve body of the back pressure valve 4, the air pressure between the high-pressure side of the air compressor and the back pressure valve can be easily adjusted; the gas in the outlet pipeline flows back to the intake pipeline.

[0052] Furthermore, the fuel cell vehicle thermal management system also includes a power battery circulating water circuit, on which a power battery 27, a battery water pump 29 and a second plate heat exchanger 28 are sequentially arranged, and a third electronic three-way valve 16 is arranged on the air pipe between the air outlet of the air compressor and the air inlet of the second plate heat exchanger, and the right air outlet of the third electronic three-way valve 16 and the air outlet of the second plate heat exchanger are respectively connected to the air inlet pipeline through the air pipe. With this solution, when the power battery is cold-started at low temperature, the controller can control the third electronic three-way valve 16 to switch the working mode of the three-way valve, i.e., the connection mode of each port, so that the high-temperature and high-pressure gas generated by the air compressor can flow through the second plate heat exchanger 28, and then flow back to the air inlet pipeline through the air pipe, so that the high-temperature and high-pressure gas can be used to heat the cooling water in the power battery circulating water circuit, and the heater in the existing power battery circulating water circuit is omitted, simplifying the structure of the thermal management system, so that the energy of the high-temperature and high-pressure gas generated by the air compressor is fully utilized, and the energy utilization rate of the thermal management system is improved. When there is no need to use high-temperature and high-pressure gas to heat the power battery, that is, when the high-temperature and high-pressure gas does not need to flow through the second plate heat exchanger, the controller will switch the working mode of the third electronic three-way valve 16, so that the upper air inlet of the third electronic three-way valve is connected to the right air outlet, and its lower air outlet is closed, so that the gas can flow directly back to the air intake pipeline through the right air outlet and the air pipe of the third electronic three-way valve.

[0053] Specifically, a Chiller heat exchanger 26 is also provided on the power battery circulating water circuit, and the Chiller heat exchanger 26 is located between the power battery 27 and the battery water pump 29. The power battery circulating water circuit exchanges heat with the air conditioning cooling and heating circuit through the Chiller heat exchanger. With this solution, the low-temperature coolant in the air conditioning cooling and heating circuit can be used to cool the cooling water in the power battery circulating water circuit through the Chiller heat exchanger, thereby achieving cooling of the power battery.

[0054] Furthermore, the fuel cell vehicle thermal management system also includes a motor and electrical appliance circulating water circuit, on which a motor water pump 32, a fourth electronic three-way valve 31, and a four-way valve 30 are sequentially arranged, and a first branch and a second branch are arranged in parallel between the motor water pump 32 and the fourth electronic three-way valve, the first branch is sequentially provided with a hydrogen circulation pump 33, an air compressor controller 34 and an air compressor 35, and the second branch is sequentially provided with a motor controller 36, a DCDC converter 37 and a motor 38; the left interface and the upper interface of the four-way valve 30 are respectively connected to the water outlet of the Chiller heat exchanger and the water inlet of the battery water pump, the left water outlet of the fourth electronic three-way valve is connected to its lower water outlet by a connecting water pipe, and a second radiator fan assembly 39 is arranged on the connecting water pipe. By adopting this solution, the controller controls the working mode of the fourth electronic three-way valve 31 and the working mode of the four-way valve 30. When the temperature of the power battery is low, the waste heat of the motor and electrical appliances can be used to heat the power battery; and when the temperature of the power battery is high, the second radiator fan assembly can be used to cool the power battery, thereby further improving the energy utilization rate.

[0055] Specifically, the first radiator fan assembly may be a high-temperature radiator fan assembly, and the second radiator fan assembly may be a medium-temperature radiator fan assembly. The water outlet and water inlet of the battery stack may be respectively provided with a battery stack water outlet temperature pressure sensor 6 and a battery stack water inlet temperature pressure sensor 7, the water outlet and water inlet of the power battery may be respectively provided with a power battery water outlet temperature sensor and a power battery water inlet temperature sensor, the left water outlet of the fourth electronic three-way valve may be provided with a motor and electrical appliance water inlet temperature sensor, the water outlet ends of the first branch and the second branch may be provided with motor and electrical appliance water outlet temperature sensors, and each sensor is electrically connected to the controller to facilitate automatic control.

[0056] Preferably, the air conditioning cooling and heating circuit includes an air conditioning circulation circuit, on which an air conditioning compressor 22, a condenser, a stop valve 21, a first expansion valve 20 and a second evaporator 18 are sequentially arranged, and an air conditioning branch is also arranged between the water outlet of the condenser and the water inlet of the air conditioning compressor, on which a second expansion valve 25 and the Chiller heat exchanger 26 are arranged in series. With this solution, the air conditioning circulation circuit can be used to cool the passenger compartment and the power battery when it is at a high temperature.

[0057] Specifically, the air conditioning cooling and heating circuit also includes a warm air circulation circuit, and the warm air circulation circuit is sequentially provided with a warm air water pump 24, a second PTC heater 23, the first evaporator 19 and the first plate heat exchanger 14. With this solution, the coolant in the warm air circulation circuit can be heated by the second PTC heater, and the passenger compartment of the vehicle is heated through the first evaporator.

[0058] Among them, the function of the deionizer 8 is to remove the conductivity ions in the coolant or cooling water to prevent the insulation resistance of the fuel cell from decreasing and causing high-voltage safety problems; the stack water pump is used to provide the flow and pressure required for its circulating water circuit; the electronic temperature control valve 10 is used to switch the working mode according to the system requirements to control whether the cooling water flows through the first radiator fan assembly. The automobile air conditioner of the present invention has a dual evaporator system. When there is a demand for warm air in the passenger compartment, the cooling water flows through the first plate heat exchanger 14 for heat exchange, and the blower in the evaporator box 17 in the automobile air conditioning box assembly, namely HVAC, is rotated to force the passenger compartment and the first plate heat exchanger 14 to perform convective heat exchange.

[0059] The embodiment of the present invention also provides a control method for a fuel cell vehicle thermal management system, which includes a fuel cell thermal management control method:

[0060] When the stack outlet water temperature pressure sensor 6 detects that the outlet water temperature of the stack 5 is not greater than 0°C, the controller controls the first PTC heater to operate to heat the stack. At this time, the cooling water flows through the upper outlet of the electronic temperature control valve and then flows into the stack water pump.

[0061] When the stack outlet water temperature pressure sensor 6 detects that the outlet water temperature of the stack 5 is greater than 0° C. but not greater than 65° C., the controller turns off the first PTC heater;

[0062] When the stack water outlet temperature pressure sensor 6 detects that the outlet water temperature of the stack 5 is greater than 65°C but not greater than 90°C, the controller turns off the first PTC heater, and the electronic temperature control valve opens, and the first radiator fan assembly works, so that the cooling water flows through the first radiator fan assembly to cool the stack. At this time, the upper water outlet of the electronic temperature control valve is in a closed state, and the cooling water flows through the water inlet and the right water outlet of the electronic temperature control valve, and then flows into the first radiator fan assembly.

[0063] It can be understood that when the first plate heat exchanger 14 is not needed for heat exchange, the left water outlet of the second electronic three-way valve and the lower water inlet of the first electronic three-way valve are both opened, so that cooling water can flow through the pipeline between the two, and at this time, the right water outlet of the second electronic three-way valve and the right water inlet of the first electronic three-way valve are both closed.

[0064] Furthermore, the control method of the fuel cell vehicle thermal management system also includes a power battery thermal management control method:

[0065] When the power battery outlet water temperature sensor detects that the outlet water temperature of the power battery 27 is not greater than 0°C, the controller controls the third electronic three-way valve 16 to operate, switches the working mode of the third electronic three-way valve, and connects the upper air inlet and the lower air outlet of the third electronic three-way valve, so that the high-temperature and high-pressure gas generated by the air compressor passes through the second plate heat exchanger to heat the cooling water in the power battery circulation water circuit;

[0066] When the power battery outlet water temperature sensor detects that the outlet water temperature of the power battery 27 is greater than 0°C but not greater than 35°C, the controller controls the third electronic three-way valve to operate, that is, close its lower air outlet, so that its upper air inlet is connected to the right air outlet, so that the high-temperature and high-pressure gas does not pass through the second plate heat exchanger; at the same time, the controller controls the four-way valve 30 to operate, so that the lower interface of the four-way valve is connected to the left interface, and the upper interface is connected to the right interface, so that the cooling water of the motor and electrical appliances flows through the power battery, so as to use the residual heat of the motor and electrical appliances to heat the cooling water in the circulating water circuit of the power battery. At this time, the water inlet of the fourth electronic three-way valve is connected to the left water outlet, and its lower water outlet is closed;

[0067] When the power battery water outlet temperature sensor detects that the water outlet temperature of the power battery 27 is greater than 35°C but not greater than 40°C, the controller controls the fourth electronic three-way valve 31 to operate, so that the lower water outlet of the fourth electronic three-way valve 31 is connected to its water inlet, and the left water outlet is closed, so that the cooling water flows through the second radiator fan assembly, so that the second radiator fan assembly works to cool the cooling water. Since the working mode of the four-way valve remains unchanged at this time, the cooling water of the motor and electrical appliances still flows through the power battery, thereby achieving cooling of the power battery; at the same time, the second expansion valve is controlled to open, the control solenoid valve of the Chiller heat exchanger 26 is turned on, and the air conditioner is turned on to dissipate the cooling water in the power battery circulation water circuit through the Chiller heat exchanger, thereby achieving heat dissipation for the power battery through air conditioning refrigeration, and then through the dual heat dissipation effect of the second radiator fan assembly and the Chiller heat exchanger, the power battery can be quickly cooled.

[0068] Furthermore, the control method of the fuel cell vehicle thermal management system also includes a motor and electrical appliance thermal management control method:

[0069] When the motor and electrical appliance outlet water temperature sensor detects that the motor and electrical appliance outlet water temperature is not greater than 55°C, the cooling water does not pass through the second radiator fan assembly;

[0070] When the motor and electrical appliance water outlet temperature sensor detects that the motor and electrical appliance water outlet temperature is greater than 55°C but not greater than 65°C, the controller controls the fourth electronic three-way valve 31 to operate, so that the lower water outlet of the fourth electronic three-way valve is connected to its water inlet, and the left water outlet is closed, so that the cooling water flowing out of the motor water pump passes through the first branch and the second branch, and then flows through the water inlet of the fourth electronic three-way valve, the lower water outlet of the fourth electronic three-way valve, the second radiator fan assembly, and the four-way valve, and then flows into the motor water pump, and the second radiator fan assembly is turned on to dissipate the cooling water, thereby cooling the motor and various electrical appliances.

[0071] It is understandable that, when in use, the rotation speed of each of the water pumps, the rotation speed of the cooling fans in each radiator fan assembly and the power of the heater can be flexibly set as needed or determined after calibration.

[0072] The present invention can couple the waste heat of the fuel cell cooling water with the warm air circulation loop, and at low temperatures, convert the thermal energy of the cooling water in the fuel cell circulating water circuit into warm air for the passenger compartment, thereby improving the thermal utilization rate of the system; the thermal management system takes into account the optimal operating temperature range and system safety of the fuel cell stack, power battery, motor, and air conditioner, such as meeting the needs of fuel cell heat dissipation at high temperatures, fuel cell heating at low temperatures, high-temperature heat dissipation and low-temperature heating of the power battery, and motor cooling needs; the present invention can eliminate the water heater in the power battery circulating water circuit, thereby reducing the cost of the entire vehicle, reducing the number of components in the thermal management system, and optimizing the layout of components; at the same time, the present invention can utilize the waste heat generated by the air compressor of the fuel cell cathode system to heat the power battery, thereby improving the energy utilization efficiency of the system, and, because the heat of the air compressor can heat the power battery, the heat load of the intercooler located behind the air compressor can be reduced, thereby reducing the cooling pressure of the fuel cell circulating water circuit. The control method of the present invention detects the temperature signals monitored by each sensor and uses a controller to control the actuators of the system, such as the opening of valves, the speed control of water pumps and fans, etc., so as to meet the actual needs of the system, such as fuel cell cooling, fuel cell heating needs, passenger compartment heating, etc. In the present invention, heat exchange with the warm air circulation loop is performed only after the temperature of the battery stack reaches a certain level, so that the battery stack can reach a reasonable operating temperature as soon as possible, preventing the battery stack from performing heat exchange before reaching a reasonable operating temperature, and avoiding damage to the battery stack.

[0073] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A fuel cell vehicle thermal management system, characterized in that: It includes a fuel cell circulating water circuit, a fuel cell cathode system, and an air conditioning cooling and heating circuit. The fuel cell circulating water circuit is sequentially provided with a stack, an electronic temperature control valve, a first radiator fan assembly, a second electronic three-way valve, a first plate heat exchanger, a first electronic three-way valve, and a stack water pump. The left water outlet of the second electronic three-way valve is connected to the lower water inlet of the first electronic three-way valve through a pipeline; a deionizer and a first PTC heater are arranged in series on the pipeline between the water outlet of the stack water pump and the water outlet of the stack, a connecting pipeline is arranged between the upper water outlet of the electronic temperature control valve and the water outlet of the first electronic three-way valve, and the first plate heat exchanger is used for heat exchange with the first evaporator in the air conditioning cooling and heating circuit; the fuel cell cathode system includes an air compressor and an intercooler arranged on the air inlet pipeline of the stack, a back pressure valve arranged on the air outlet pipeline of the stack, and a bypass valve arranged on the connecting air pipe between the air outlet of the back pressure valve and the air outlet of the intercooler.

2. The fuel cell vehicle thermal management system according to claim 1, characterized in that: The bypass valve is a three-way valve, and the left air outlet of the bypass valve is connected to the bypass exhaust branch.

3. The fuel cell vehicle thermal management system according to claim 1, characterized in that: It also includes a power battery circulating water circuit, on which a power battery, a battery water pump and a second plate heat exchanger are sequentially arranged, and a third electronic three-way valve is arranged on the air pipe between the air outlet of the air compressor and the air inlet of the second plate heat exchanger, and the right air outlet of the third electronic three-way valve and the air outlet of the second plate heat exchanger are respectively connected to the air inlet pipeline through air pipes.

4. The fuel cell vehicle thermal management system according to claim 3, characterized in that: The power battery circulating water circuit is also provided with a Chiller heat exchanger, and the Chiller heat exchanger is located between the power battery and the battery water pump. The power battery circulating water circuit exchanges heat with the air conditioning cooling and heating circuit through the Chiller heat exchanger.

5. The fuel cell vehicle thermal management system according to claim 4, characterized in that: It also includes a motor and electrical appliance circulating water circuit, on which a motor water pump, a fourth electronic three-way valve, and a four-way valve are sequentially arranged; a first branch and a second branch are arranged in parallel between the motor water pump and the fourth electronic three-way valve; a hydrogen circulation pump, an air compressor controller, and an air compressor are sequentially arranged on the first branch; a motor controller, a DCDC converter, and a motor are sequentially arranged on the second branch; the left interface and the upper interface of the four-way valve are respectively connected to the water outlet of the Chiller heat exchanger and the water inlet of the battery water pump; the water outlet of the fourth electronic three-way valve and its lower water outlet are connected via a connecting water pipe, and a second radiator fan assembly is arranged on the connecting water pipe.

6. The fuel cell vehicle thermal management system according to claim 4, characterized in that: The air-conditioning cooling and heating circuit includes an air-conditioning circulation circuit, on which an air-conditioning compressor, a condenser, a stop valve, a first expansion valve and a second evaporator are sequentially arranged, and an air-conditioning branch is also arranged between the water outlet of the condenser and the water inlet of the air-conditioning compressor, and the second expansion valve and the Chiller heat exchanger are arranged in series on the air-conditioning branch.

7. The fuel cell vehicle thermal management system according to claim 6, characterized in that: The air conditioning cooling and heating circuit also includes a warm air circulation circuit, and a warm air water pump, a second PTC heater, the first evaporator and the first plate heat exchanger are sequentially arranged on the warm air circulation circuit.

8. A control method for a fuel cell vehicle thermal management system, characterized in that: It includes: When the stack outlet water temperature pressure sensor detects that the stack outlet water temperature is not greater than 0°C, the controller controls the first PTC heater to operate; When the stack outlet water temperature pressure sensor detects that the stack outlet water temperature is greater than 0°C but not greater than 65°C, the controller turns off the first PTC heater; When the stack outlet water temperature pressure sensor detects that the stack outlet water temperature is greater than 65°C but not greater than 90°C, the controller turns off the first PTC heater, and the electronic temperature control valve opens, and the first radiator fan assembly works, so that cooling water flows through the first radiator fan assembly.

9. The control method of the fuel cell vehicle thermal management system according to claim 8, characterized in that: It also includes: When the power battery outlet water temperature sensor detects that the power battery outlet water temperature is not greater than 0°C, the controller controls the third electronic three-way valve to operate, so that the high-temperature and high-pressure gas generated by the air compressor passes through the second plate heat exchanger to heat the cooling water in the power battery circulation water circuit; When the power battery outlet water temperature sensor detects that the power battery outlet water temperature is greater than 0°C but less than 35°C, the controller controls the third electronic three-way valve to operate so that the high-temperature and high-pressure gas does not pass through the second plate heat exchanger; at the same time, the controller controls the four-way valve to operate so that the residual heat of the motor and electrical appliances is used to heat the cooling water in the power battery circulation water circuit; When the power battery water outlet temperature sensor detects that the power battery water outlet temperature is greater than 35°C but not greater than 40°C, the controller controls the four-way valve and the fourth electronic three-way valve to allow the cooling water to pass through the second radiator fan assembly, and at the same time controls the second expansion valve to open to dissipate the heat of the cooling water in the power battery circulating water circuit.

10. The control method of the thermal management system of a fuel cell vehicle according to claim 8, characterized in that: It also includes: When the motor and electrical appliance outlet water temperature sensor detects that the motor and electrical appliance outlet water temperature is not greater than 55°C, the cooling water does not pass through the second radiator fan assembly; When the motor and electrical appliance water outlet temperature sensor detects that the motor and electrical appliance water outlet temperature is greater than 55°C but not greater than 65°C, the controller controls the fourth electronic three-way valve to operate and simultaneously turns on the second radiator fan assembly so that cooling water passes through the second radiator fan assembly.

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