Air-cooled fuel cell system and control method thereof

Abstract

The invention discloses an air-cooled fuel cell system and a control method thereof.The air-cooled fuel cell system comprises an electric pile, an air supply system, a hydrogen supply system, a heat dissipation system and an electrical system, the air supply system and the hydrogen supply system are both connected with the electric pile, the air supply system is a closed air supply system, and the hydrogen supply system is a closed hydrogen supply system; the closed air supply system comprises an air filter, an air blower and a pile entering stop valve which are connected in sequence, and one end of the pile entering stop valve is connected with the electric pile. The closed air supply system and the open heat dissipation system are used, the problems that the open air supply system is short in service life and low in efficiency are solved, the system performance is stable and reliable, and modular design and control management are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to an air-cooled fuel cell system and a control method thereof. Background Art

[0002] At present, facing the problem of decreasing global fossil fuel reserves and increasingly serious air pollution, the emergence of fuel cells has provided mankind with a new way to alleviate the two major problems of energy crisis and air pollution, and has become a hot topic of extensive research in the world. Fuel cells have become an important new energy source with rapid development due to their high efficiency and green environmental protection advantages. Among them, proton exchange membrane fuel cells (PEMFC) have broad application prospects in many fields with their high specific power, high energy conversion efficiency, rapid start-up and environmental friendliness, and have been recognized by the world. Among them, the PEMFC system with air cooling technology, which is widely used in small-power fuel cells such as drones, mobile power supplies, and small forklifts, has problems such as short system life and low efficiency due to the open structure design of the battery cooling system and air supply that is directly in contact with the external environment.

[0003] For example, patent CN111584899A discloses a control system for an air-cooled fuel cell stack, which comprises a hydrogen pressure regulating valve, a hydrogen flowmeter and a hydrogen pressure sensor respectively connected to a control device on a hydrogen pipeline connected to the air-cooled fuel cell stack, and an air-cooled motor connected to the control device at a position close to the air-cooled fuel cell stack, and a first opening of a sealing mask is connected to an exhaust end of the air-cooled motor, and a second opening of the sealing mask is connected to an air outlet end of the air-cooled fuel cell stack, so that when the air-cooled motor exhausts air in a direction away from the air-cooled fuel cell stack, a negative pressure can be generated in the sealing mask, thereby utilizing the negative pressure to cause air to flow through the cathode channel in the air-cooled fuel cell stack, thereby achieving air supply and heat dissipation for the air-cooled fuel cell stack; the fuel cell cooling system and air supply adopt a through-open structure design, and direct contact with the external environment will bring about problems of short system life and low efficiency. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides an air-cooled fuel cell system and a control method thereof, wherein the system is stable and reliable, and the service life and working efficiency are effectively improved.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] An air-cooled fuel cell system comprises a fuel cell stack, an air supply system, a hydrogen supply system, a heat dissipation system and an electrical system, wherein the air supply system and the hydrogen supply system are both connected to the fuel cell stack, and the air supply system is a closed air supply system, which comprises an air filter, a blower and a stack entry shut-off valve connected in sequence, and one end of the stack entry shut-off valve is connected to the fuel cell stack.

[0007] The heat dissipation system includes a heat dissipation fan arranged corresponding to the battery stack. A temperature sensor is arranged on the battery stack. The temperature sensor is electrically connected to the heat dissipation fan. The heat dissipation fan adjusts the rotation speed of the heat dissipation fan according to the temperature signal detected by the battery stack temperature sensor.

[0008] An air mass flow meter is arranged between the air filter and the blower.

[0009] A temperature sensor and a pressure sensor for detecting the air temperature and pressure before the air supply system enters the stack are arranged between the blower and the stack entry stop valve.

[0010] The hydrogen supply system includes a hydrogen cylinder, a pressure reducing valve and a hydrogen inlet solenoid valve connected in sequence. A temperature sensor and a pressure sensor for detecting the air temperature and pressure before the hydrogen supply system enters the stack are provided between the pressure reducing valve and the hydrogen inlet solenoid valve.

[0011] The air supply system also includes an electronic throttle valve arranged on the fuel cell stack. The electronic throttle valve adjusts the pressure in the fuel cell stack by adjusting its valve opening and cooperating with the blower. The electronic throttle valve has a sealing function to prevent air from entering the fuel cell stack after shutdown.

[0012] The air filter comprises a physical filtering structure and a chemical adsorption structure for adsorbing gases in the air that are harmful to the membrane electrode.

[0013] The electric propeller is provided with a hydrogen exhaust solenoid valve, which is a pulse exhaust valve.

[0014] A startup control method for an air-cooled fuel cell system is as follows: first, the state parameters of the fuel cell system are detected, and after the state is detected to be normal, the cooling fan is started and the cooling fan is operated at the lowest speed; at the same time, the air supply system sequentially opens the stack shut-off valve, adjusts the valve angle of the electronic throttle valve, starts the blower and provides the work and pressure required for the idle point; in addition, the anode hydrogen supply system, opens the pressure reducing valve, opens the exhaust solenoid valve, opens the hydrogen intake solenoid valve, performs the exhaust action and closes the exhaust solenoid valve, and at this point, the startup of the fuel cell system is completed.

[0015] A shutdown control method for an air-cooled fuel cell system is as follows: first, the hydrogen intake solenoid valve is closed, the exhaust solenoid valve is opened, the cooling fan rotates at the maximum wind speed, and the temperature of the fuel cell stack is detected. If it is lower than the shutdown temperature, the air supply system turns off the blower, the stack intake shut-off valve, and the electronic throttle valve. The hydrogen supply system turns off the exhaust solenoid valve, turns off the electrical system, and turns off the cooling system fan. At this point, the shutdown of the fuel cell system is completed.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] The air-cooled fuel cell system and its control method are reasonably designed, using a closed air supply system and an open heat dissipation system to solve the problems of short life and low efficiency of the open air supply system. The system performance is stable and reliable, and is convenient for modular design and control management. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The following is a brief description of the contents and symbols in the drawings of this specification:

[0019] Figure 1 It is a connection diagram of the fuel cell system of the present invention.

[0020] Figure 2 This is a diagram of the startup process of the fuel cell system of the present invention.

[0021] Figure 3 This is a shutdown process diagram of the fuel cell system of the present invention.

[0022] In the figure:

[0023] 1. Air filter, 2. Mass flow meter, 3. Blower, 4. Stack shut-off valve, 5. Electronic throttle valve, 6. Hydrogen intake solenoid valve, 7. Pressure reducing valve, 8. Hydrogen cylinder, 9. Hydrogen exhaust solenoid valve, 10. Cooling fan, 11. DC / DC inverter. DETAILED DESCRIPTION

[0024] The specific implementation modes of the present invention will be further explained in detail below through the description of embodiments with reference to the accompanying drawings.

[0025] like Figures 1 to 3 As shown, the air-cooled fuel cell system and control method thereof of the present invention use a closed air supply system and an open heat dissipation system to solve the problems of short life and low efficiency of the open air supply system, and at the same time provide a control method for opening and closing the air-cooled fuel cell system, which has outstanding advantages such as stable and reliable system performance and very easy to implement modular design.

[0026] The air-cooled fuel cell system includes a fuel cell stack, an air supply system, a hydrogen supply system, a heat dissipation system and an electrical system. The air supply system and the hydrogen supply system are both connected to the fuel cell stack. The air supply system is a closed air supply system. The closed air supply system includes an air filter, a blower and a stack entry shut-off valve connected in sequence. One end of the stack entry shut-off valve is connected to the fuel cell stack.

[0027] An air mass flow meter is installed between the air filter and the blower to monitor whether the air intake flow meets the requirements of the fuel cell stack. A temperature sensor and a pressure sensor are installed between the blower and the shut-off valve for detecting the air temperature and pressure before the air supply system enters the fuel cell stack.

[0028] The air filter includes a physical filtration structure and a chemical adsorption structure for adsorbing gases in the air that are harmful to the membrane electrode; the physical filtration structure can use a traditional filter element to filter impurities and dust in the air; the chemical adsorption structure can use chemical agents to adsorb nitrogen compounds and sulfides in the air.

[0029] The air supply system also includes an electronic throttle valve installed on the fuel cell stack. The electronic throttle valve adjusts the pressure in the fuel cell stack by adjusting its valve opening and cooperating with the blower. The electronic throttle valve has a sealing function to prevent air from entering the fuel cell stack after shutdown.

[0030] The hydrogen supply system includes a hydrogen cylinder, a pressure reducing valve and a hydrogen inlet solenoid valve connected in sequence. A temperature sensor and a pressure sensor for detecting the air temperature and pressure before the hydrogen supply system enters the stack are provided between the pressure reducing valve and the hydrogen inlet solenoid valve.

[0031] The electric propulsion system is equipped with a hydrogen exhaust solenoid valve, which is a pulse exhaust valve that takes away the water generated in the fuel cell stack to prevent the fuel cell stack from being flooded.

[0032] The heat dissipation system includes a cooling fan arranged corresponding to the fuel cell stack. A temperature sensor is provided on the fuel cell stack. The temperature sensor is electrically connected to the cooling fan. The cooling fan adjusts the speed of the cooling fan according to the temperature signal detected by the fuel cell stack temperature sensor, thereby taking away the heat generated by the fuel cell stack and ensuring the optimal working temperature of the fuel cell stack.

[0033] The electrical system steps up or down the voltage of the direct current generated by the battery stack to meet actual usage requirements, and mainly includes a DC / DC inverter.

[0034] In the present invention, the fuel cell stack is a place where air and hydrogen undergo chemical reaction to convert chemical energy into electrical energy. A temperature sensor is provided on the fuel cell stack to detect the temperature of the fuel cell stack. The air supply system mainly functions to provide an appropriate amount of air for the fuel cell stack. The hydrogen supply system mainly functions to provide an appropriate amount of hydrogen for the fuel cell stack. The heat dissipation system takes away the heat generated by the fuel cell stack to ensure the optimal working temperature of the fuel cell stack. The closed air supply system and the open heat dissipation system are used to solve the problems of short life and low efficiency of the open air supply system. The system performance is stable and reliable, and modular design and control management are convenient.

[0035] The startup control method of the air-cooled fuel cell system of the present invention is: first, the state parameters of the fuel cell system are detected, and the cooling fan is started after the state is detected to be normal, and the cooling fan is operated at the lowest speed; at the same time, the air supply system sequentially opens the stack shut-off valve, adjusts the valve angle of the electronic throttle valve, starts the blower and provides the work and pressure required by the idle point, and in addition, the anode hydrogen supply system, opens the pressure reducing valve, opens the exhaust solenoid valve, opens the hydrogen intake solenoid valve, performs the exhaust action and closes the exhaust solenoid valve, and at this point, the startup of the fuel cell system is completed.

[0036] The shutdown control method of the air-cooled fuel cell system of the present invention is: first, close the hydrogen intake solenoid valve, open the exhaust solenoid valve, rotate the cooling fan at the maximum wind speed, and detect the temperature of the fuel cell stack. If it is lower than the shutdown temperature, the air supply system turns off the blower, the stack intake shut-off valve, and the electronic throttle valve, the hydrogen supply system turns off the exhaust solenoid valve, the electrical system, and the cooling system turns off the fan. At this point, the shutdown of the fuel cell system is completed.

[0037] like Figures 1 to 3 As shown, preferred embodiments of the present invention are:

[0038] The air-cooled fuel cell system of the present invention comprises a fuel cell stack, an air supply system, a hydrogen supply system, a heat dissipation system and an electrical system;

[0039] The fuel cell stack is a place where air and hydrogen undergo chemical reactions to convert chemical energy into electrical energy. A temperature sensor is provided on the fuel cell stack to detect the temperature of the fuel cell stack as T1. The main function of the air supply system is to provide an appropriate amount of air for the fuel cell stack. It includes an air filter 1, an air mass flow meter 2, a blower 3, a stack entry shutoff valve 4, and an electronic throttle valve 5. A temperature sensor and a pressure sensor are provided between the blower 3 and the stack entry shutoff valve 4 to detect the air temperature and pressure before the air supply system enters the stack.

[0040] The air filter 1 can perform physical filtration and chemical adsorption. Physical filtration can filter impurities and dust in the air, and chemical filtration can adsorb gases such as nitrides and sulfides in the air that are harmful to the membrane electrode, and provide clean air for the stack after air filtration. The mass flow meter 2 is used to monitor whether the air intake flow rate meets the requirements of the stack. The gas compressed by the blower 3 meets the requirements of the stack for air pressure and flow, and the blower speed is adjusted according to the needs of the stack. The stack entry shut-off valve 4 opens the valve when the stack is working and closes the valve when the stack is shut down. The stack entry shut-off valve 4 has a sealing function to prevent air from entering the stack after shutdown. The electronic throttle valve 5 adjusts the pressure in the stack by adjusting its valve opening and cooperating with the blower 3, and the electronic throttle valve 5 has a sealing function to prevent air from entering the stack after shutdown.

[0041] The main function of the hydrogen supply system is to provide an appropriate amount of hydrogen for the operation of the fuel cell stack. It mainly includes a hydrogen bottle 8, a pressure reducing valve 7, a hydrogen inlet solenoid valve 6, and a hydrogen exhaust solenoid valve 9. A temperature sensor and a pressure sensor are provided between the pressure reducing valve 7 and the hydrogen inlet solenoid valve 6 to detect the air temperature and pressure before the hydrogen supply system enters the stack.

[0042] The hydrogen cylinder 8 provides a hydrogen source for the operation of the fuel cell system. The pressure reducing valve 7 adjusts the hydrogen in the hydrogen cylinder 8 to the working pressure required by the fuel cell stack. The hydrogen intake solenoid valve 6 is used to control the switch of hydrogen. The hydrogen exhaust solenoid valve 9 controls the switch of hydrogen exhaust. When the fuel cell system is working, pulse exhaust is performed according to the signal of the hydrogen side pressure sensor to take away the water generated in the fuel cell stack to prevent the fuel cell stack from being flooded.

[0043] The electrical system steps up or down the voltage of the direct current generated by the battery stack to meet actual usage requirements, and mainly includes a DC / DC inverter 11.

[0044] The heat dissipation system takes away the heat generated by the battery stack to ensure the optimal working temperature of the battery stack. It mainly includes a heat dissipation fan 10. The heat dissipation fan 10 is driven by the temperature signal T detected by the battery stack temperature sensor. stack , adjust the fan speed to make the stack work at the optimal temperature. The specific temperature control method is as follows: according to the stack output current I, calculate the stack temperature T that makes the fuel cell operating performance optimal under the current current 1 , and then compared with the actual temperature of the current stack T 2 The error signal e is obtained by comparison. The control voltage of the stack cooling fan is adjusted according to the error signal e, and the speed of the cooling fan is changed, thereby achieving real-time control of the stack temperature. Finally, the stack is controlled to operate near the optimal operating temperature.

[0045] Furthermore, the present invention provides a startup control method for a fuel cell system, which first detects the state of the fuel cell system, including a fuel cell stack, a mass flow meter 2, a blower 3, a stack inlet shut-off valve 4, an electronic throttle valve 5, a hydrogen intake solenoid valve 6, a pressure reducing valve 7, a hydrogen exhaust solenoid valve 9, a cooling fan 10, and a DC / DC inverter 11.

[0046] After the status is detected to be normal, the cooling fan 10 is started and runs at the lowest speed. At the same time, the air supply system opens the stack shut-off valve 4, adjusts the valve angle of the electronic throttle valve 5, turns on the blower 3 and provides the working flow and pressure required by the idle point. In addition, the anode supply system opens the pressure reducing valve 7, opens the exhaust solenoid valve 9, opens the hydrogen intake solenoid valve, performs the exhaust action for 1s and closes the exhaust solenoid valve. At this point, the fuel cell system startup is completed;

[0047] Furthermore, the present invention provides a shutdown control method for a fuel cell system, firstly closing the hydrogen inlet solenoid valve 6 to stop the hydrogen from entering the stack, and then opening the tail gas exhaust solenoid valve 9 to consume the hydrogen in the stack. The cooling fan 10 rotates at the maximum wind speed to detect the temperature T of the PEMFC stack. 2 , according to the optimal shutdown temperature T of the battery stack 3 , if T 2 >T 3 , the fan continues to run.

[0048] If T 2 <T 3 , the air supply system turns off the blower 3, stops the purge and air supply, and at the same time closes the stack stop valve 4 and the electronic throttle valve 5 to seal. At the same time, the hydrogen supply system turns off the exhaust solenoid valve 9, turns off the electrical system DC / DC inverter 11, and turns off the fan 10 of the cooling system. At this point, the fuel cell system is shut down.

[0049] The above is only an explanation of the preferred embodiments of the present invention, and the above technical features can be arbitrarily combined to form multiple embodiments of the present invention.

[0050] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. An air-cooled fuel cell system, comprising a fuel cell stack, an air supply system, a hydrogen supply system, a heat dissipation system and an electrical system, wherein the air supply system and the hydrogen supply system are both connected to the fuel cell stack, and characterized in that: The air supply system is a closed air supply system, which includes an air filter, a blower and a stack entry shut-off valve connected in sequence, and one end of the stack entry shut-off valve is connected to the fuel cell stack.

2. The air-cooled fuel cell system according to claim 1, characterized in that: The heat dissipation system includes a heat dissipation fan arranged corresponding to the battery stack. A temperature sensor is arranged on the battery stack. The temperature sensor is electrically connected to the heat dissipation fan. The heat dissipation fan adjusts the rotation speed of the heat dissipation fan according to the temperature signal detected by the battery stack temperature sensor.

3. The air-cooled fuel cell system according to claim 1, characterized in that: An air mass flow meter is arranged between the air filter and the blower.

4. The air-cooled fuel cell system according to claim 1, characterized in that: A temperature sensor and a pressure sensor for detecting the air temperature and pressure before the air supply system enters the stack are arranged between the blower and the stack entry stop valve.

5. The air-cooled fuel cell system according to claim 1, characterized in that: The hydrogen supply system includes a hydrogen cylinder, a pressure reducing valve and a hydrogen inlet solenoid valve connected in sequence. A temperature sensor and a pressure sensor for detecting the air temperature and pressure before the hydrogen supply system enters the stack are provided between the pressure reducing valve and the hydrogen inlet solenoid valve.

6. The air-cooled fuel cell system according to claim 1, characterized in that: The air supply system also includes an electronic throttle valve arranged on the fuel cell stack. The electronic throttle valve adjusts the pressure in the fuel cell stack by adjusting its valve opening and cooperating with the blower. The electronic throttle valve has a sealing function to prevent air from entering the fuel cell stack after shutdown.

7. The air-cooled fuel cell system according to claim 1, characterized in that: The air filter comprises a physical filtering structure and a chemical adsorption structure for adsorbing gases in the air that are harmful to the membrane electrode.

8. The air-cooled fuel cell system according to claim 5, characterized in that: The electric propeller is provided with a hydrogen exhaust solenoid valve, which is a pulse exhaust valve.

9. A startup control method for an air-cooled fuel cell system according to any one of claims 1 to 8, characterized in that: The startup control method is: First, the status parameters of the fuel cell system are detected. After the status is normal, the cooling fan is started and operated at the lowest speed. At the same time, the air supply system opens the stack shut-off valve in sequence, adjusts the valve angle of the electronic throttle valve, starts the blower and provides the work and pressure required for the idle point. In addition, the anode hydrogen supply system, the pressure reducing valve, the exhaust solenoid valve, the hydrogen intake solenoid valve, the exhaust action and the exhaust solenoid valve are closed. At this point, the fuel cell system startup is completed.

10. A shutdown control method for an air-cooled fuel cell system according to any one of claims 1 to 8, characterized in that: The shutdown control method is: First, close the hydrogen intake solenoid valve, open the exhaust solenoid valve, rotate the cooling fan at the maximum wind speed, and detect the temperature of the fuel cell stack. If it is lower than the shutdown temperature, the air supply system shuts down the blower, closes the stack shut-off valve, and closes the electronic throttle valve. The hydrogen supply system closes the exhaust solenoid valve, shuts down the electrical system, and shuts down the cooling system fan. At this point, the fuel cell system shutdown is complete.

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