Fuel cell thermal management system and method

Abstract

The present invention relates to the technical field of fuel cell thermal management, and in particular to a fuel cell thermal management system and method. The system comprises a fuel cell (1), a water pump (2), a PTC heater (3), an electronic thermostat valve (4), an intercooler (5), an intercooler valve (6), a radiator (7), a water tank (8), a fuel cell coolant inlet temperature sensor (9), a fuel cell coolant outlet temperature sensor (10), a radiator coolant outlet temperature sensor (11), an ambient temperature sensor (12), an atmospheric pressure sensor (13), and a vehicle speed sensor (14). The present invention enables rational control of a fan speed of the fuel cell thermal management system, enables precise control of a working temperature of the fuel cell, improves the efficiency of the fuel cell, prolongs the service life of the fuel cell, and improves the operating efficiency of a locomotive. Additionally, the present invention eliminates the effects of ambient temperature, atmospheric pressure, and fuel cell efficiency degradation factors on thermal management control, thereby ensuring the effectiveness of the fuel cell thermal management throughout the entire life cycle.

Description

Fuel Cell Thermal Management System and Method Technical Field

[0001] This invention relates to the field of fuel cell thermal management technology, and in particular to fuel cell thermal management systems and methods. Background Technology

[0002] A fuel cell is an electrochemical device that continuously and directly converts the chemical energy of a continuously supplied fuel and oxidant into electrical energy. Classified by electrolyte type and fuel type, there are various types of fuel cells, including proton exchange membrane fuel cells, molten carbonate fuel cells, and solid oxide fuel cells. Currently, the main type used in the transportation sector is the proton exchange membrane fuel cell, which uses hydrogen as fuel and air as the oxidant, with an efficiency of 40%–60%. The fuel cell thermal management system transfers the generated heat to the outside environment to maintain the fuel cell's operating temperature. Fuel cell efficiency and lifespan are strongly correlated with the fuel cell's operating temperature; therefore, the thermal management system plays a crucial role in the entire fuel cell system. Currently, fuel cell temperature is typically controlled using a hydrothermal management system. Specifically, the hydrothermal management system includes an electronic thermostat. By controlling the opening of the electronic thermostat, the mixing ratio of the liquid before and after heat dissipation is adjusted, thereby changing the temperature of the mixed liquid entering the fuel cell and thus controlling the fuel cell temperature.

[0003] In existing technologies, the cooling fan speed is mostly determined by looking up a table based on the fuel cell current and ambient temperature, without considering the increased cooling demand caused by fuel cell degradation. Technical issues

[0004] To overcome the shortcomings of existing cooling fans that cannot adjust their speed and airflow according to the conditions of the fuel cell, this invention provides a fuel cell thermal management system and method. Technical solutions

[0005] The technical solution adopted by the present invention to solve its technical problem is: a fuel cell thermal management system, including a fuel cell (1), a water pump (2), a PTC heater (3), an electronic thermostat (4), an intercooler (5), an intercooler valve (6), a radiator (7), a water tank (8), a fuel cell coolant inlet temperature sensor (9), a fuel cell coolant outlet temperature sensor (10), a radiator coolant outlet temperature sensor (11), an ambient temperature sensor (12), an atmospheric pressure sensor (13), a vehicle speed sensor (14), a vehicle control unit (15), a fuel cell control unit (16), a fuel cell output current sensor (17), a fuel cell output voltage sensor (18), a radiator coolant inlet pressure sensor (19), and a radiator coolant outlet pressure sensor (20).

[0006] Water pump (2) is connected to water tank (8), intercooler (5), PTC heater (3) and fuel cell (1) through pipelines respectively. Electronic thermostatic valve (4) is connected to fuel cell (1), PTC heater (3), intercooler valve (6) and radiator (7) through pipelines respectively. A fuel cell coolant inlet temperature sensor (9) is installed at the coolant inlet of fuel cell (1). A fuel cell coolant outlet temperature sensor (10) is installed at the coolant outlet of fuel cell (1). A fuel cell output current sensor (17) and a fuel cell output voltage sensor (18) are installed on the electrical output side of fuel cell (1). A radiator coolant inlet pressure sensor (19) is installed at the coolant inlet of radiator (7). A radiator coolant outlet temperature sensor (11) and a radiator coolant outlet pressure sensor (20) are installed at the coolant outlet of radiator (7). A cooling fan is installed inside radiator (7).

[0007] The ambient temperature sensor (12), atmospheric pressure sensor (13), and vehicle speed sensor (14) are all electrically connected to the vehicle control unit (15). The fuel cell (1), water pump (2), PTC heater (3), electronic thermostat (4), intercooler (5), intercooler valve (6), radiator (7), fuel cell coolant inlet temperature sensor (9), fuel cell coolant outlet temperature sensor (10), radiator coolant outlet temperature sensor (11), fuel cell output current sensor (17), fuel cell output voltage sensor (18), radiator coolant inlet pressure sensor (19), and radiator coolant outlet pressure sensor (20) are all electrically connected to the fuel cell control unit (16). The vehicle control unit (15) and the fuel cell control unit (16) are electrically connected and exchange data through a bus communication network.

[0008] A fuel cell thermal management method includes the following steps:

[0009] S1, based on the fuel cell output power P e Predict the power P required by the cooling fan rad ;

[0010] S2. Based on the fuel cell outlet temperature T1, radiator outlet temperature T2, coolant flow rate q, ambient temperature T0, atmospheric pressure P0, vehicle speed v, and the power required by the cooling fan P. rad Controls the start and stop of the cooling fan and calculates its speed;

[0011] S3. Control the opening value k of the electronic thermostatic valve according to the inlet temperature T3 of the fuel cell coolant;

[0012] The control of the cooling fan includes cooling fan start / stop F201 and cooling fan speed control F202.

[0013] According to another embodiment of the present invention, the fuel cell outlet temperature T1 is obtained by a fuel cell coolant outlet temperature sensor (10), the radiator outlet temperature T2 is obtained by a radiator coolant outlet temperature sensor (11), the coolant flow rate q is obtained by a radiator coolant inlet pressure sensor (19) and a radiator coolant outlet pressure sensor (20), the ambient temperature T0 is obtained by an ambient temperature sensor (12), the atmospheric pressure P0 is obtained by an atmospheric pressure sensor (13), the vehicle speed v is obtained by a vehicle speed sensor (14), and the fuel cell coolant inlet temperature T3 is obtained by a fuel cell coolant inlet temperature sensor (9).

[0014] According to another embodiment of the present invention, step S1 further includes the power P required by the cooling fan. rad The calculation formula is:

[0015] P rad = P 0 - P e - P m - P v + P a

[0016] In the formula, P0 is the output power of the fuel cell chemical reaction; P e P represents the electrical power output of the fuel cell. m Power released by mass flow in a fuel cell system, including gas and liquid flow; P v Power absorbed by the water phase change inside the fuel cell; P a This represents the power required by the intercooler of the fuel cell.

[0017] According to another embodiment of the present invention, it further includes the chemical reaction output power P0 of the fuel cell and the electrical power P output by the fuel cell. e The power P released by the mass flow of the fuel cell system m The power P absorbed by the water phase change inside the fuel cell v The power P required to be carried away by the intercooler of the fuel cell a Respectively related to the fuel cell output current I o Fuel cell output voltage U o Suggested functional relationships:

[0018] P0 = f(a1, I o )

[0019] P e = f(a2,I o U o )

[0020] P m = f(a3,I o )

[0021] P m = f(a4,I o )

[0022] P v = f(a5,I o )

[0023] P a = f(a6,I o )

[0024] In the formula, the fuel cell output current I o The fuel cell output voltage U is obtained through the fuel cell output current sensor (17). o The voltage is obtained by the fuel cell output voltage sensor (18), and a1, a2, a3, a4, a5, and a6 are proportional coefficients summarized from the fuel cell load test.

[0025] According to another embodiment of the present invention, the cooling fan start / stop F201 further includes cooling fan start conditions and cooling fan stop conditions; the cooling fan start condition is that the fuel cell outlet temperature T1 is greater than T start The cooling fan stops when the fuel cell outlet temperature T1 is less than T. stop .

[0026] According to another embodiment of the present invention, the speed calculation formula of the cooling fan speed control F202 is further included as follows:

[0027]

[0028] In the formula n rad V is the fan speed. f Where V is the required fan airflow, v is the vehicle speed, and T2 is the radiator outlet temperature. This is the target temperature at the radiator outlet.

[0029] According to another embodiment of the invention, it further includes the aforementioned The cooling fan speed is adjusted using PID control. The input value for PID control is the radiator outlet temperature T2, and the target value is the radiator outlet temperature target value. .

[0030] According to another embodiment of the present invention, the airflow calculation formula of the cooling fan speed control F202 is further included as follows:

[0031] V f= f(P rad W f ,q,Δt)

[0032] In the formula W f Δt is the air heat capacity, q is the coolant flow rate, and Δt is the temperature difference between the air and the coolant.

[0033] W f Obtained through calculations based on atmospheric pressure;

[0034] q is calculated using the radiator coolant inlet pressure P1 and the radiator coolant outlet pressure P2.

[0035] Δt is calculated using the ambient temperature T0 and the fuel cell outlet temperature T1.

[0036] According to another embodiment of the present invention, the calculation formula for the opening value k of the electronic thermostatic valve is further included as follows:

[0037]

[0038] In the formula, T3 is the actual temperature of the fuel cell coolant inlet. The target temperature for the fuel cell coolant inlet;

[0039] The formula uses PID control to adjust the opening value k of the electronic thermostat valve. The input value of PID control is the actual temperature T3 of the fuel cell coolant inlet, and the target value of PID control is the target temperature of the fuel cell coolant inlet. Beneficial effects

[0040] The beneficial effects of this invention are that it enables reasonable control of the fan speed in the fuel cell thermal management system, accurate control of the fuel cell operating temperature, improved fuel cell efficiency and lifespan, and enhanced vehicle operating efficiency. Simultaneously, it addresses the impact of ambient temperature, atmospheric pressure, and fuel cell efficiency degradation on thermal management control, ensuring the effectiveness of fuel cell thermal management throughout its entire lifespan. Attached Figure Description

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0042] Figure 1 is a schematic diagram of the structure of the present invention;

[0043] Figure 2 is a flowchart of the method of the present invention;

[0044] In the diagram: 1. Fuel cell, 2. Water pump, 3. PTC heater, 4. Electronic thermostat, 5. Intercooler, 6. Intercooler valve, 7. Radiator, 8. Water tank, 9. Fuel cell coolant inlet temperature sensor, 10. Fuel cell coolant outlet temperature sensor, 11. Radiator coolant outlet temperature sensor, 12. Ambient temperature sensor, 13. Atmospheric pressure sensor, 14. Vehicle speed sensor, 15. Vehicle control unit, 16. Fuel cell control unit, 17. Fuel cell output current sensor, 18. Fuel cell output voltage sensor, 19. Radiator coolant inlet pressure sensor, 20. Radiator coolant outlet pressure sensor. Embodiments of the present invention

[0045] Figure 1 is a structural schematic diagram of the present invention; Figure 2 is a flowchart of the method of the present invention.

[0046] As shown in Figure 1, a fuel cell thermal management system includes a fuel cell (1), a water pump (2), a PTC heater (3), an electronic thermostat (4), an intercooler (5), an intercooler valve (6), a radiator (7), a water tank (8), a fuel cell coolant inlet temperature sensor (9), a fuel cell coolant outlet temperature sensor (10), a radiator coolant outlet temperature sensor (11), an ambient temperature sensor (12), an atmospheric pressure sensor (13), a vehicle speed sensor (14), a vehicle control unit (15), a fuel cell control unit (16), a fuel cell output current sensor (17), a fuel cell output voltage sensor (18), a radiator coolant inlet pressure sensor (19), and a radiator coolant outlet pressure sensor (20).

[0047] Water pump (2) is connected to water tank (8), intercooler (5), PTC heater (3) and fuel cell (1) through pipelines respectively. Electronic thermostatic valve (4) is connected to fuel cell (1), PTC heater (3), intercooler valve (6) and radiator (7) through pipelines respectively. A fuel cell coolant inlet temperature sensor (9) is installed at the coolant inlet of fuel cell (1). A fuel cell coolant outlet temperature sensor (10) is installed at the coolant outlet of fuel cell (1). A fuel cell output current sensor (17) and a fuel cell output voltage sensor (18) are installed on the electrical output side of fuel cell (1). A radiator coolant inlet pressure sensor (19) is installed at the coolant inlet of radiator (7). A radiator coolant outlet temperature sensor (11) and a radiator coolant outlet pressure sensor (20) are installed at the coolant outlet of radiator (7). A cooling fan is installed inside radiator (7).

[0048] The ambient temperature sensor (12), atmospheric pressure sensor (13), and vehicle speed sensor (14) are all electrically connected to the vehicle control unit (15). The fuel cell (1), water pump (2), PTC heater (3), electronic thermostat (4), intercooler (5), intercooler valve (6), radiator (7), fuel cell coolant inlet temperature sensor (9), fuel cell coolant outlet temperature sensor (10), radiator coolant outlet temperature sensor (11), fuel cell output current sensor (17), fuel cell output voltage sensor (18), radiator coolant inlet pressure sensor (19), and radiator coolant outlet pressure sensor (20) are all electrically connected to the fuel cell control unit (16). The vehicle control unit (15) and the fuel cell control unit (16) are electrically connected and exchange data through a bus communication network.

[0049] A fuel cell thermal management method includes the following steps:

[0050] S1, based on the fuel cell output power P e Predict the power P required by the cooling fan rad ;

[0051] The power P required by the cooling fan rad The calculation formula is:

[0052] P rad = P 0 - P e - P m - P v + P a

[0053] In the formula, P0 is the output power of the fuel cell chemical reaction; P e P represents the electrical power output of the fuel cell. m Power released by mass flow in a fuel cell system, including gas and liquid flow; P v Power absorbed by the water phase change inside the fuel cell; P a This represents the power required by the intercooler of the fuel cell.

[0054] P rad In the calculation formula, the power P0 generated by the chemical reaction of fuel cell 1 is a constant, and the calculation is based on the high calorific value ΔH = 285.84 kJ / mol; the electrical energy P output by fuel cell 1 is... e The output voltage U of fuel cell 1 can be measured. o With current I oCalculate the energy released by the mass flow of the fuel cell system, the energy absorbed by the water phase change inside fuel cell 1, and the heat removed by fuel cell 1 and intercooler 5, which together account for 1% to 2% of the total energy. This should be compared with the fuel cell output current I. o Fuel cell output voltage U o The coefficient relationships can be summarized from experimental data.

[0055] S2. Based on the fuel cell outlet temperature T1, radiator outlet temperature T2, coolant flow rate q, ambient temperature T0, atmospheric pressure P0, vehicle speed v, and the power required by the cooling fan P. rad Controls the start and stop of the cooling fan and calculates its speed;

[0056] The control of the cooling fan includes the cooling fan start / stop F201 and the cooling fan speed control F202.

[0057] The cooling fan start / stop function F201 includes the cooling fan start condition and the cooling fan stop condition; the cooling fan start condition is that the fuel cell outlet temperature T1 is greater than T. start The cooling fan stops when the fuel cell outlet temperature T1 is less than T. stop .

[0058] The formula for calculating the fan speed of the F202 cooling fan is as follows:

[0059]

[0060] In the formula n rad V is the fan speed. f Where V is the required fan airflow, v is the vehicle speed, and T2 is the radiator outlet temperature. This is the target temperature at the radiator outlet.

[0061] The cooling fan speed is adjusted using PID control. The input value for PID control is the radiator outlet temperature T2, and the target value is the radiator outlet temperature target value. .

[0062] The formula for calculating the airflow of the F202 cooling fan speed control is as follows:

[0063] V f = f(P rad W f ,q,Δt)

[0064] In the formula W f Δt is the air heat capacity, q is the coolant flow rate, and Δt is the temperature difference between the air and the coolant.

[0065] W f Obtained through calculations based on atmospheric pressure;

[0066] q is calculated using the radiator coolant inlet pressure P1 and the radiator coolant outlet pressure P2.

[0067] Δt is calculated using the ambient temperature T0 and the fuel cell outlet temperature T1.

[0068] S3. Control the opening value k of the electronic thermostatic valve according to the inlet temperature T3 of the fuel cell coolant;

[0069] The formula for calculating the opening value k of an electronic thermostatic valve is: .

[0070] In the formula, T3 is the actual temperature of the fuel cell coolant inlet. The target temperature for the fuel cell coolant inlet; The formula uses PID control to adjust the opening value k of the electronic thermostat valve. The input value of PID control is the actual temperature T3 of the fuel cell coolant inlet, and the target value of PID control is the target temperature of the fuel cell coolant inlet.

Claims

1. A fuel cell thermal management system, characterized by, The system comprises a fuel cell (1), a water pump (2), a PTC heater (3), an electronic thermostat valve (4), an intercooler (5), an intercooler valve (6), a radiator (7), a water tank (8), a fuel cell coolant inlet temperature sensor (9), a fuel cell coolant outlet temperature sensor (10), a radiator coolant outlet temperature sensor (11), an ambient temperature sensor (12), an atmospheric pressure sensor (13), a vehicle speed sensor (14), a vehicle control unit (15), a fuel cell control unit (16), a fuel cell output current sensor (17), a fuel cell output voltage sensor (18), a radiator coolant inlet pressure sensor (19), a radiator coolant outlet pressure sensor (20); The water pump (2) is connected to the water tank (8), the intercooler (5), the PTC heater (3) and the fuel cell (1) through pipelines respectively, the electronic thermostat valve (4) is connected to the fuel cell (1), the PTC heater (3), the intercooler valve (6) and the radiator (7) through pipelines respectively, the fuel cell coolant inlet temperature sensor (9) is installed at the coolant inlet of the fuel cell (1), the fuel cell coolant outlet temperature sensor (10) is installed at the coolant outlet of the fuel cell (1), the fuel cell output current sensor (17) and the fuel cell output voltage sensor (18) are installed at the electrical output side of the fuel cell (1), the radiator coolant inlet pressure sensor (19) is installed at the coolant inlet of the radiator (7), the radiator coolant outlet temperature sensor (11) and the radiator coolant outlet pressure sensor (20) are installed at the coolant outlet of the radiator (7), and a radiator fan is installed in the radiator (7); The ambient temperature sensor (12), the atmospheric pressure sensor (13) and the vehicle speed sensor (14) are electrically connected to the vehicle control unit (15), the fuel cell (1), the water pump (2), the PTC heater (3), the electronic thermostat valve (4), the intercooler (5), the intercooler valve (6), the radiator (7), the fuel cell coolant inlet temperature sensor (9), the fuel cell coolant outlet temperature sensor (10), the radiator coolant outlet temperature sensor (11), the fuel cell output current sensor (17), the fuel cell output voltage sensor (18), the radiator coolant inlet pressure sensor (19) and the radiator coolant outlet pressure sensor (20) are electrically connected to the fuel cell control unit (16), the vehicle control unit (15) is electrically connected to the fuel cell control unit (16), and data is exchanged through a bus communication network.

2. A fuel cell thermal management method according to claim 1, characterized by, The method comprises the following steps: S1, depending on the fuel cell output electric power P e Predict the power P needed by the cooling fan rad ; S2, according to fuel cell outlet temperature T1, radiator outlet temperature T2, coolant flow rate q, ambient temperature T0, atmospheric pressure P0, vehicle speed v, power P required by the radiator fan rad , controls the start-stop of the radiator fan and calculates the rotational speed; S3, controlling the opening value k of the electronic thermostat valve according to the fuel cell coolant inlet temperature T3; The control of the radiator fan comprises starting and stopping the radiator fan F201 and controlling the rotating speed of the radiator fan F202.

3. The fuel cell thermal management method of claim 2, characterized by, The fuel cell outlet temperature T1 is acquired by a fuel cell coolant outlet temperature sensor (10), the radiator outlet temperature T2 is acquired by a radiator coolant outlet temperature sensor (11), the coolant flow q is acquired by a radiator coolant inlet pressure sensor (19) and a radiator coolant outlet pressure sensor (20), the ambient temperature T0 is acquired by an ambient temperature sensor (12), the atmospheric pressure P0 is acquired by an atmospheric pressure sensor (13), the vehicle speed v is acquired by a vehicle speed sensor (14), and the fuel cell coolant inlet temperature T3 is acquired by a fuel cell coolant inlet temperature sensor (9).

4. The fuel cell thermal management method of claim 2, wherein the step of In S1, the power P required by the heat dissipation fan rad The calculation formula is: P rad = P 0 - P e - P m - P v + P a where P0 is the fuel cell chemical reaction output power; P e is the fuel cell electrical output power; P m is the fuel cell system mass flow released power, including gas and liquid flow; P v is the fuel cell internal water phase change absorbed power; P a is the fuel cell intercooler required power.

5. The fuel cell thermal management method of claim 4, characterized by, The fuel cell chemical reaction output power P0, the fuel cell external output electric power P e The fuel cell system mass flow released power P m The fuel cell internal water phase change absorbed power P v The fuel cell intercooler required to take away power P a The fuel cell output current I o The fuel cell output voltage U o The suggested function relationship: P0= f(a1, I o ) P e = f(a2,I o ,U o ) P m = f(a3,I o ) P m = f(a4,I o ) P v = f(a5,I o ) P a = f(a6,I o ) In the formula, the fuel cell output current I o The fuel cell output voltage U is obtained through the fuel cell output current sensor (17). o The voltage is obtained by the fuel cell output voltage sensor (18), and a1, a2, a3, a4, a5, and a6 are proportional coefficients summarized from the fuel cell load test.

6. The fuel cell thermal management method of claim 2, characterized by, The heat dissipation fan start-stop F201 includes a heat dissipation fan start condition and a heat dissipation fan stop condition; the heat dissipation fan start condition is that the fuel cell outlet temperature T1 is greater than T start ; and the heat dissipation fan stop condition is that the fuel cell outlet temperature T1 is less than T stop .

7. The fuel cell thermal management method of claim 2, wherein, The rotation speed calculation formula of the heat dissipation fan rotation speed control F202 is: In the formula, n rad is the heat dissipation fan rotation speed, V f is the required fan air volume, v is the vehicle speed, T2 is the radiator outlet temperature, is the radiator outlet target temperature.

8. The fuel cell thermal management method of claim 7, characterized by, Said PID control is adopted to regulate the rotating speed of the heat dissipation fan, the input value of the PID regulation is the radiator outlet temperature T2, and the target value of the PID regulation is the radiator outlet target temperature .

9. The fuel cell thermal management method of claim 2, characterized by, The air volume calculation formula of the radiator fan rotating speed control F202 is: V f = f(P rad ,W f ,q,Δt) where W f for the air heat capacity, q is the coolant flow rate, and Δt is the air temperature minus the coolant temperature difference; W f By atmospheric pressure calculation; The q is acquired by the radiator coolant inlet pressure P1 and the radiator coolant outlet pressure P2; The Δt is acquired by the ambient temperature T0 and the fuel cell outlet temperature T1.

10. The fuel cell thermal management method of claim 2, characterized by, The calculation formula of the electronic expansion valve opening value k is: In the formula, T3 is the actual temperature of the fuel cell coolant inlet, The fuel cell coolant inlet target temperature is T4; The formula adopts a PID control to adjust the electronic expansion valve opening k value, the input value of the PID adjustment is the fuel cell coolant inlet actual temperature T3, and the target value of the PID adjustment is the fuel cell coolant inlet target temperature.

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