FPGA-based open cathode fuel cell temperature control device and method

Abstract

The present application provides an FPGA-based open cathode fuel cell temperature control device and method. The FPGA-based open cathode fuel cell temperature control device includes a cooling fan, an FPGA controller, a first temperature sensor, a second temperature sensor, and a current sensor. The FPGA controller is electrically connected to the cooling fan. The first temperature sensor and the second temperature sensor respectively measure the inlet air temperature and the real-time operating temperature of the fuel cell stack. The current sensor measures the fuel cell stack current. The FPGA controller first determines whether the inlet air temperature is within the allowable operating temperature range, and then calculates the optimal operating temperature set for the fuel cell stack based on the inlet air temperature and the fuel cell stack current; the FPGA controller adjusts the duty cycle of the cooling fan voltage connected to the fuel cell stack based on the difference between the real-time operating temperature of the fuel cell stack measured by the second temperature sensor and the set optimal operating temperature, and controls the motor speed of the cooling fan through a PWM DC motor speed regulator.

Description

Technical Field

[0001] The present application belongs to the field of fuel cell technology, and more specifically, relates to an open cathode fuel cell temperature control device and control method based on FPGA (Field Programmable Gate Array). Background Art

[0002] Fuel cell technology has become an important development direction of global new energy now and in the future due to its advantages of high power generation efficiency, low carbon, environmental protection and pollution-free, and its market share is also increasing.

[0003] The energy conversion efficiency of fuel cells can reach 40%-60%, and the heat that cannot be converted into electrical energy in the electrochemical reaction will be converted into thermal energy and dissipated, causing the temperature of the fuel cell to increase. Therefore, the temperature control of the fuel cell is an important component of the fuel cell system.

[0004] As a type of proton exchange membrane fuel cell, the open cathode fuel cell greatly reduces costs due to the lack of other auxiliary systems, which can solve the problem of high fuel cell prices.

[0005] The temperature of an open-cathode proton exchange membrane fuel cell is of great significance to the fuel cell's efficiency and service life. If the battery temperature is too low, the electrochemical reaction will slow down, causing the battery performance to decline. However, excessively high temperatures will cause the evaporation of liquid water, thereby reducing the conductivity of protons and degrading battery performance. Controlling the temperature of the open-cathode fuel cell stack becomes a problem when other auxiliary systems are removed. Therefore, maintaining the low cost and simple structure of the open-cathode fuel cell without other auxiliary systems while also being able to simply and effectively control the temperature of the stack has become a problem that those skilled in the art need to solve. Summary of the Invention

[0006] The purpose of the embodiments of the present application is to provide an FPGA-based open cathode fuel cell temperature control device and control method to solve the technical problem in the prior art that it is difficult to simply and effectively control the temperature of an open cathode fuel cell.

[0007] To achieve the above objectives, the present application adopts a technical solution: providing an FPGA-based open cathode fuel cell temperature control device, comprising a cooling fan, an FPGA controller, a first temperature sensor, a second temperature sensor, and a current sensor. The cooling fan is connected to the open cathode fuel cell. The FPGA controller is electrically connected to the cooling fan. The first temperature sensor is electrically connected to the FPGA controller to measure the inlet air temperature of the fuel cell stack in real time. The second temperature sensor is electrically connected to the FPGA controller to measure the real-time operating temperature of the fuel cell stack. The current sensor is connected to the open cathode fuel cell and a load to form a loop to measure the fuel cell stack current. The FPGA controller first determines whether the inlet air temperature is within the allowable operating temperature range, and then calculates the optimal operating temperature set for the fuel cell stack based on the inlet air temperature and the fuel cell stack current. The FPGA controller adjusts the duty cycle of the cooling fan voltage based on the difference between the real-time operating temperature of the fuel cell stack measured by the second temperature sensor and the set optimal operating temperature, and controls the motor speed of the cooling fan via a PWM DC motor speed regulator, thereby adjusting the wind speed of the cooling fan.

[0008] Optionally, the FPGA-based open cathode fuel cell temperature control device includes a sealed fixture, and the heat dissipation fan is sealedly connected to the open cathode fuel cell through the sealed fixture.

[0009] Optionally, the sealed fixture is a shell with a channel in the middle, one end of the shell is connected to the open cathode fuel cell, and the other end of the shell is connected to the cooling fan.

[0010] Optionally, the cooling fan and the open cathode fuel cell are coordinated in a suction manner.

[0011] Optionally, the FPGA-based open cathode fuel cell temperature control device includes a power supply, and the power supply, the FPGA controller and the cooling fan are connected to form a loop.

[0012] Optionally, the power source is one of a lithium battery, a storage battery, and a supercapacitor;

[0013] And / or, the cooling fan is a DC axial flow fan or a DC centrifugal fan;

[0014] And / or, the FPGA-based open cathode fuel cell temperature control device includes an oxygen concentration sensor provided on the open cathode fuel cell stack;

[0015] And / or, the FPGA-based open cathode fuel cell temperature control device includes a relative humidity sensor provided on the open cathode fuel cell stack;

[0016] And / or, the FPGA-based open cathode fuel cell temperature control device includes a hydrogen concentration sensor provided on the open cathode fuel cell stack.

[0017] According to another aspect of the present invention, the present invention further provides a temperature control method for an open cathode fuel cell based on FPGA, comprising the following steps:

[0018] Detecting the inlet air temperature T of the open cathode fuel cell stack in , the real-time operating temperature of the stack T s And the stack current I s ;

[0019] Determine the air inlet temperature T in If 10℃≤T in ≤40℃, calculate the optimal operating temperature T of the stack according to the formula opt =0.46I s +33.63; if -20℃≤T in <10℃ or 40℃<T in ≤50℃, calculate the optimal operating temperature T of the stack according to the formula opt =0.53I s +26.01; if T in <-20℃ or T in >50℃, then T in If the permissible operating temperature range is exceeded, the system stops running;

[0020] Calculate the real-time operating temperature T of the stack s The difference between the optimal operating temperature of the stack and DIF = T s -T opt ;

[0021] Determine the size of DIF and -LIMIT, where LIMIT is the maximum difference between the actual operating temperature allowed by the fuel cell stack and the optimal stack temperature. If DIF < -LIMIT, the cooling fan connected to the open cathode fuel cell is controlled to run at the minimum wind speed; if DIF ≥ -LIMIT and DIF > LIMIT, the cooling fan is controlled to run at the maximum wind speed; if DIF ≥ -LIMIT and DIF ≤ LIMIT, the duty cycle of the cooling fan voltage is calculated according to the formula Fan n+1 (%) = 100*DIF / (2*LIMIT)+Fan n (%), of which Fan n (%) is the duty cycle of the cooling fan voltage before adjustment, Fan n+1 (%) is the duty cycle of the cooling fan voltage after adjustment. The FPGA controller adjusts the duty cycle of the cooling fan voltage to Fan through the PWM DC motor speed regulator. n+1 (%), PWM DC motor speed regulator controls the motor speed of the cooling fan, thereby adjusting the wind speed of the cooling fan.

[0022] Optionally, the inlet air temperature T of the open cathode fuel cell stack is detected by the first temperature sensor and the second temperature sensor respectively. in And the real-time operating temperature of the stack T s and the inlet air temperature T in And the real-time operating temperature of the stack T s Feedback to the FPGA controller.

[0023] Optionally, the cooling fan achieves heat dissipation by drawing air from the open cathode fuel cell stack.

[0024] Optionally, the FPGA controller and the cooling fan are started by controlling an external power supply;

[0025] and / or, adjusting the inlet hydrogen pressure of the open cathode fuel cell to a range of: 1.2-1.6 bar;

[0026] and / or, detecting the oxygen concentration of the open cathode fuel cell by an oxygen concentration sensor;

[0027] and / or, detecting the relative humidity of the open cathode fuel cell stack by a relative humidity sensor;

[0028] And / or, the hydrogen concentration of the open cathode fuel cell stack is detected by a hydrogen concentration sensor.

[0029] The beneficial effects of the FPGA-based open cathode fuel cell temperature control device and control method provided in the present application are: compared with the existing technology, the FPGA-based open cathode fuel cell temperature control device and control method of the present application adjusts the duty cycle of the cooling fan voltage through the FPGA controller according to the difference between the measured real-time operating temperature of the fuel cell stack and the set optimal operating temperature, thereby adjusting the speed of the cooling fan, and finally achieving the control and regulation of the open cathode fuel cell temperature, with fast response speed and precise temperature control, which can avoid overshoot oscillation and other phenomena, making the working environment of the fuel cell more stable and improving the output performance, service life and reliability of the fuel cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0031] Figure 1A schematic diagram of the structure of an open cathode fuel cell temperature control device based on FPGA provided in an embodiment of the present application;

[0032] Figure 2 A three-dimensional structural diagram of the cooling fan, sealed fixture, and open cathode fuel cell of the FPGA-based open cathode fuel cell temperature control device provided in an embodiment of the present application, assembled together at one viewing angle;

[0033] Figure 3 A three-dimensional structural diagram of the overall assembly of a cooling fan, a sealed fixture, and an open cathode fuel cell of an FPGA-based open cathode fuel cell temperature control device provided in an embodiment of the present application, viewed from another perspective;

[0034] Figure 4 This is a flow chart of the FPGA-based open cathode fuel cell temperature control method provided in an embodiment of the present application.

[0035] Among them, the reference numerals in the figures are:

[0036] 10-Cooling fan; 20-FPGA controller; 30-Sealed fixture; 40-Power supply; 300-Open cathode fuel cell stack; 310-Hydrogen tank; 320-Pressure regulator; 330-Load; 340-Isolation diode; 350-Hydrogen purge valve. DETAILED DESCRIPTION

[0037] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0038] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0039] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0041] Please also refer to Figure 1 and Figure 2 The following describes an FPGA (Field Programmable Gate Array)-based open cathode fuel cell temperature control device provided in an embodiment of the present application. The FPGA-based open cathode fuel cell temperature control device includes a cooling fan 10, an FPGA (Field Programmable Gate Array) controller 20, a first temperature sensor, a second temperature sensor, and a current sensor.

[0042] The cooling fan 10 is connected to the open cathode fuel cell to dissipate heat from the open cathode fuel cell, thereby regulating the temperature of the open cathode fuel cell. Figure 1 As shown, taking a 1000W open cathode fuel cell stack 300 as an example, the open cathode fuel cell is connected to a 5L hydrogen tank 310 and a pressure regulator 320 at its fuel input end. The pressure regulator 320 can be a manual pressure regulator such as a pressure reducing valve. The pressure regulator 320 reduces the pressure of the high-pressure hydrogen from the hydrogen tank 310 to a range of 1.2-1.6 bar (bar is the unit of pressure bar). The open cathode fuel cell stack 300 does not require external air humidification and directly uses air for electrochemical reactions. A hydrogen pressure sensor is connected to the hydrogen inlet of the open cathode fuel cell stack 300. The precise hydrogen pressure at the hydrogen inlet of the fuel cell can be seen through the hydrogen pressure sensor ( Figure 1 Indicated as P H2 The hydrogen outlet of the fuel cell stack 300 uses a dead-end design, meaning that all fuel entering the anode of the open cathode fuel cell is consumed (i.e., the fuel stoichiometric ratio is 1). However, water vapor produced by the reaction, as well as nitrogen and other inert gases that permeate from the cathode to the anode, can accumulate in the anode, reducing the battery's output performance. Therefore, a hydrogen purge valve 350 must be installed on the anode side to periodically purge the hydrogen. The hydrogen purge valve 350 prevents the accumulation of inert gases, ensuring normal system operation and preventing unsafe indoor conditions.

[0043] The FPGA controller 20 is electrically connected to the cooling fan 10 , so that the electrode speed of the cooling fan 10 can be controlled by the FPGA controller 20 , thereby adjusting the fan of the cooling fan 10 and ultimately adjusting the temperature of the open cathode fuel cell.

[0044] The first temperature sensor is electrically connected to the FPGA controller 20 to measure the inlet air temperature of the open cathode fuel cell stack 300 in real time and feed it back to the FPGA controller 20. During installation, the first temperature sensor is placed at the air inlet of the fuel cell stack 300 to measure the inlet air temperature.

[0045] The second temperature sensor is electrically connected to the FPGA controller 20 to measure the real-time operating temperature of the open cathode fuel cell stack 300 and feed it back to the FPGA controller 20. During installation, the second temperature sensor is placed in the middle area of the cathode flow channel of a single cell in the middle of the fuel cell stack 300 to facilitate measurement of the real-time operating temperature of the fuel cell stack 300.

[0046] In the working state, the current sensor, the open cathode fuel cell and the load 330 are connected to form a loop. The open cathode fuel cell supplies power to the load 330 , and the current sensor is used to measure the stack current.

[0047] The open cathode fuel cell stack 300 is also electrically connected to a voltage sensor to measure the stack's real-time voltage. Furthermore, a relay and an isolation diode 340 are connected between the open cathode fuel cell and the load 330. The relay isolates the load 330 from the open cathode fuel cell, while the isolation diode 340 prevents reverse current flow.

[0048] During operation, the FPGA controller 20 first determines whether the inlet air temperature is within the allowable operating temperature range based on the stack inlet air temperature value measured by the first temperature sensor. If the inlet air temperature is not within the allowable operating temperature range, the entire FPGA-based open cathode fuel cell temperature control device stops operating. If the inlet air temperature is within the allowable operating temperature range, the FPGA controller 20 calculates the optimal operating temperature set for the stack based on the inlet air temperature and the stack current. Then, the FPGA controller 20 adjusts the duty cycle of the cooling fan 10 voltage based on the difference between the real-time stack operating temperature measured by the second temperature sensor and the set optimal operating temperature, and sends a duty cycle signal to the PWM (Pulse width modulation) DC motor speed regulator to control the motor speed of the cooling fan 10, thereby adjusting the wind speed of the cooling fan 10. By repeating the above steps, the temperature of the open cathode fuel cell stack 300 can be adjusted in real time, so that the temperature of the stack 300 is always controlled within the optimal operating temperature range.

[0049] The FPGA-based open cathode fuel cell temperature control device provided in this application has a fast response speed and precise temperature control compared with the existing technology. It can avoid overshoot oscillation and other phenomena, making the working environment of the fuel cell more stable and improving the output performance, service life and reliability of the fuel cell.

[0050] In another embodiment of this application, please refer to Figure 2 The FPGA-based open cathode fuel cell temperature control device includes a sealed fixture 30, through which the cooling fan 10 is sealedly connected to the open cathode fuel cell. The sealed fixture 30 acts as an air guide, preventing air leakage. This allows all air to be transferred and circulated between the cooling fan 10 and the open cathode fuel cell through the sealed fixture 30. This facilitates the high-speed air generated by the cooling fan 10 to pass through the cathode flow channel of the fuel cell stack 300, avoiding the formation of a preferential path and achieving more effective heat dissipation for the open cathode fuel cell.

[0051] In another embodiment of this application, please refer to Figure 2 The sealed fixture 30 is a shell with a channel in the middle. One end of the shell is connected to the open cathode fuel cell, and the other end of the shell is connected to the cooling fan 10. In this way, the connection between the cooling fan 10 and the open cathode fuel cell is achieved.

[0052] In another embodiment of the present application, the cooling fan 10 and the open cathode fuel cell are coordinated to form an air suction system. By using the cooling fan 10 to draw air into the open cathode fuel cell stack 300, rather than installing the cooling fan 10 at the stack air inlet to blow air into the stack 300, the negative pressure formed at the air outlet of the stack 300 will evenly distribute the airflow through the stack 300, resulting in a uniform air flow rate.

[0053] Optionally, the heat dissipation fan 10 is a DC axial flow fan or a DC centrifugal fan, for example, a San Ace 92 DC axial flow fan.

[0054] Optionally, the FPGA controller 20 uses a controller with model number XC6SLX45-2CSG324I.

[0055] In another embodiment of this application, please refer to Figure 1The FPGA-based open cathode fuel cell temperature control device includes a power supply 40. The power supply 40, the FPGA controller 20, and the cooling fan 10 are connected to form a loop. Thus, the power supply 40 can power the FPGA controller 20 and the cooling fan 10. Because the open cathode fuel cell cannot supply power during the initial startup process, the power supply 40 is required to provide an auxiliary power source to power the entire FPGA-based open cathode fuel cell temperature control device.

[0056] Optionally, the power source 40 is a lithium battery, a storage battery, or a supercapacitor. Figure 1 As shown, the power source 40 is a lithium battery, and a battery voltage sensor is electrically connected to the side of the power source 40 for monitoring and warning the status of the power source 40. Figure 1 The voltage of the power supply 40 is marked as V B .

[0057] In another embodiment of the present application, Figure 1 As shown, the FPGA-based open cathode fuel cell temperature control device includes an oxygen concentration sensor provided on the open cathode fuel cell stack 300. The oxygen concentration sensor can monitor the oxygen concentration in the atmosphere around the stack 300 in real time ( Figure 1 Marked as C O2 ) to prevent the oxygen concentration in the surrounding atmosphere from being too low and to ensure that the electrochemical reaction in the open cathode fuel cell stack 300 proceeds normally.

[0058] In another embodiment of the present application, Figure 1 As shown, the FPGA-based open cathode fuel cell temperature control device includes a relative humidity sensor provided on the open cathode fuel cell stack 300. The relative humidity sensor can monitor the relative humidity of the air surrounding the open cathode fuel cell stack 300 in real time ( Figure 1 RH in the figure) to prevent the stack 300 from operating in overly dry air conditions.

[0059] In another embodiment of the present application, Figure 1 As shown, the FPGA-based open cathode fuel cell temperature control device includes a hydrogen concentration sensor provided in the open cathode fuel cell stack 300 to detect the hydrogen concentration ( Figure 1 Marked as C H2 ) to prevent hydrogen leakage accidents.

[0060] See also Figure 2The present application also provides a temperature control method for an open cathode fuel cell based on an FPGA (Field Programmable Gate Array), the temperature control method for an open cathode fuel cell based on an FPGA comprising the following steps:

[0061] Detecting the inlet air temperature T of the open cathode fuel cell stack 300 in , the real-time operating temperature of the stack T s And the stack current I s ;

[0062] Determine the air inlet temperature T in If 10℃≤T in ≤40℃, calculate the optimal operating temperature T of the stack according to the formula opt =0.46I s +33.63; if -20℃≤T in <10℃ or 40℃<T in ≤50℃, calculate the optimal operating temperature T of the stack according to the formula opt =0.53I s +26.01; if T in <-20℃ or T in >50℃, then T in If the permissible operating temperature range is exceeded, the system stops running;

[0063] Calculate the real-time operating temperature T of the stack s The difference between the optimal operating temperature of the stack and DIF = T s -T opt ;

[0064] Determine the size of DIF and -LIMIT, where LIMIT is the maximum difference between the actual operating temperature allowed by the fuel cell stack and the optimal stack temperature. If DIF < -LIMIT, the cooling fan connected to the open cathode fuel cell is controlled to run at the minimum wind speed; if DIF ≥ -LIMIT and DIF > LIMIT, the cooling fan is controlled to run at the maximum wind speed; if DIF ≥ -LIMIT and DIF ≤ LIMIT, the duty cycle of the cooling fan voltage is calculated according to the formula Fan n+1 (%) = 100*DIF / (2*LIMIT)+Fan n (%), of which Fan n (%) is the duty cycle of the cooling fan voltage before adjustment, Fan n+1(%) is the duty cycle of the cooling fan voltage after adjustment. The FPGA (Field Programmable Gate Array) controller adjusts the duty cycle of the cooling fan voltage to Fan through the PWM (Pulse Width Modulation) DC motor speed regulator. n+1 (%), PWM DC motor speed regulator controls the motor speed of the cooling fan, thereby adjusting the wind speed of the cooling fan.

[0065] Specifically, a first temperature sensor is set at the air inlet of the open cathode fuel cell stack 300, and a second temperature sensor is set in the middle area of the cathode flow channel of a single cell in the middle position of the open cathode fuel cell stack 300. The first temperature sensor and the second temperature sensor are electrically connected to the FPGA controller 20 respectively, and the inlet air temperature T of the open cathode fuel cell stack 300 is detected by the first temperature sensor and the second temperature sensor respectively. in and the real-time operating temperature T of the stack 300 s and the inlet air temperature T in and the real-time operating temperature of the stack T s Feedback to FPGA controller 20. A current sensor is connected in series between the open cathode fuel cell and the load 330, and the stack current I is measured by the current sensor. s .

[0066] Then the FPGA controller 20 determines the air inlet temperature T in If the air inlet temperature T in If the air inlet temperature is lower than -20℃ or higher than 50℃, the air inlet temperature T in The system stops running when the air inlet temperature T in In the allowable operating temperature range, the open cathode fuel cell stack 300 is operated according to the air inlet temperature T in There is an optimal stack operating temperature for different in When ≤40℃, according to the formula T opt =0.46I s +33.63Calculate the optimal operating temperature T of the stack opt ; When -20℃≤T in <10℃ or 40℃<T in When ≤50℃, according to the formula T opt =0.53I s +26.01 Calculate the optimal operating temperature T of the stack opt .

[0067] By keeping the open cathode fuel cell stack 300 near this operating temperature, the stack performance and cell stability can be achieved. However, in reality, the actual operating temperature T of the open cathode fuel cell stack 300 is s Often the optimal operating temperature of the stack T opt There is a certain difference between them, so it is necessary to control and adjust the temperature of the stack 300 so that the actual operating temperature T s As close as possible to the optimal operating temperature T of the stack opt .

[0068] Next, calculate the real-time operating temperature T of the stack s The difference between the optimal operating temperature of the stack and DIF = T s -T opt This facilitates the targeted and precise adjustment of the real-time operating temperature T of the open fuel cell stack 300 according to the size of the difference DIF in the subsequent steps. s .

[0069] The FGPA controller 20 determines the values of DIF and -LIMIT based on the values calculated above. Generally speaking, the maximum difference between the actual operating temperature allowed by the open cathode fuel cell stack and the optimal temperature of the stack is 3-5°C. The FGPA controller 20 accurately adjusts the speed of the cooling fan 10 connected to the open cathode fuel cell according to the size of the difference DIF, thereby adjusting the actual operating temperature T of the stack 300 in real time. s The details are as follows:

[0070] If DIF<-LIMIT, it means the actual operating temperature of the stack 300 is T s If the temperature is lower than the theoretical optimal temperature of the fuel cell stack and the temperature difference exceeds the maximum allowable difference range LIMIT, the cooled fuel cell stack 300 needs to be heated. Overcooling of the fuel cell stack 300 may cause flooding of the battery, thereby affecting battery performance. Therefore, the cooling fan 10 connected to the open cathode fuel cell is controlled to operate at a minimum wind speed. The purpose of maintaining the cooling fan at its lowest controllable speed is to avoid the problem of insufficient air in the fuel cell stack 300, thereby providing the minimum amount of air required for the operation of the fuel cell stack 300.

[0071] If DIF≥-LIMIT and DIF>LIMIT, it represents the actual operating temperature T of the stack 300. s The temperature is higher than the theoretically set optimal temperature of the fuel cell stack and the temperature difference far exceeds the maximum allowable difference range LIMIT. The temperature of the fuel cell stack 300 is overheated, and the cooling fan is controlled to operate at the maximum wind speed to ensure the amount of air required for the electrochemical reaction and heat dissipation of the open cathode fuel cell stack 300, thereby ensuring the control of the fuel cell stack temperature.

[0072] If DIF≥-LIMIT and DIF≤LIMIT, it represents the actual operating temperature T of the stack 300. s If the temperature is higher or lower than the theoretically set optimal temperature of the stack, but the temperature difference does not exceed the maximum allowable difference range LIMIT, the duty cycle of the voltage of the cooling fan 10 is calculated according to the following formula:

[0073] Fan n+1 (%) = 100*DIF / (2*LIMIT)+Fan n (%)

[0074] Among them, Fan n (%) is the duty cycle of the cooling fan voltage before adjustment, Fan n+1 (%) is the duty cycle of the cooling fan voltage after adjustment. The FPGA controller 20 adjusts the duty cycle signal of the cooling fan 10 voltage to the PWM DC motor speed regulator. The PWM DC motor speed regulator controls the motor speed of the cooling fan 10, thereby adjusting the wind speed of the cooling fan 10. In this way, the cooling fan 10 is adjusted with a duty cycle Fan n+1 Repeat the above adjustment steps until the stack temperature reaches a stable level.

[0075] Optionally, the FPGA controller 20 uses a controller with a model number of XC6SLX45-2CSG324I. The cooling fan 10 is a DC axial flow fan or a DC centrifugal fan, such as a San Ace 92 DC axial flow fan.

[0076] In another embodiment of the present application, a cooling fan 10 connected to the open cathode fuel cell achieves heat dissipation by sucking air from the open cathode fuel cell stack 300, such as Figure 1 The direction of air flow is shown in FIG. By using the cooling fan 10 to draw air into the fuel cell stack 300, rather than installing the cooling fan 10 at the air inlet of the fuel cell stack 300 and blowing air into the fuel cell stack 300, a uniform air flow rate can be achieved. The negative pressure zone formed at the air outlet will help evenly distribute the airflow through the fuel cell stack 300.

[0077] In another embodiment of the present application, the FPGA controller 20 and the cooling fan 10 are started by controlling an external power supply 40. Because the open cathode fuel cell cannot immediately provide power during initial startup, it is necessary to use an auxiliary power supply 40 to power the FPGA controller 20 and the cooling fan 10. Optionally, the power supply 40 is a lithium battery, a storage battery, or a supercapacitor. Figure 1 As shown, the power source 40 is a lithium battery, and a battery voltage sensor is electrically connected to the side of the power source 40 for monitoring and warning the status of the power source 40. Figure 1 The voltage of the power supply 40 is marked as V B .

[0078] In another embodiment of the present application, the inlet hydrogen pressure of the open cathode fuel cell is adjusted to a range of 1.2-1.6 bar (bar is the unit of pressure). Figure 1 As shown, taking a 1000W open cathode fuel cell stack 300 as an example, the open cathode fuel cell is connected to a 5L hydrogen tank 310 and a pressure regulator 320 at its fuel input end. The pressure regulator 320 can adopt a manual pressure regulator such as a pressure reducing valve. The pressure regulator 320 reduces the pressure of the high-pressure hydrogen from the hydrogen tank 310 to the range of 1.2-1.6 bar. The open cathode fuel cell stack 300 does not require external air humidification and directly uses air for electrochemical reactions. A hydrogen pressure sensor is connected to the hydrogen inlet of the open cathode fuel cell stack 300. The precise hydrogen pressure at the hydrogen inlet of the fuel cell can be seen through the hydrogen pressure sensor ( Figure 1 Indicated as P H2 The hydrogen outlet of the fuel cell stack 300 uses a dead-end design, meaning that all fuel entering the anode of the open cathode fuel cell is consumed (the fuel stoichiometric ratio is 1). However, water vapor produced by the reaction, as well as nitrogen and other inert gases that permeate from the cathode to the anode, can accumulate in the anode, reducing battery output performance. Therefore, a hydrogen purge valve 350 must be installed on the anode side to regularly purge the hydrogen. The hydrogen purge valve 350 prevents the accumulation of inert gases, ensuring normal system operation and preventing unsafe indoor conditions.

[0079] In another embodiment of the present application, a hydrogen concentration sensor is also used to detect the hydrogen concentration of the open cathode fuel cell stack 300. A hydrogen concentration sensor is installed in the open cathode fuel cell stack 300 to detect the hydrogen concentration ( Figure 1 Marked as C H2 ) to prevent hydrogen leakage accidents.

[0080] In another embodiment of the present application, an oxygen concentration sensor is used to detect the oxygen concentration of the open cathode fuel cell. An oxygen concentration sensor is installed on the open cathode fuel cell stack 300, and the oxygen concentration sensor can monitor the oxygen concentration in the atmosphere around the stack 300 in real time ( Figure 1 Marked as C O2 ) to prevent the oxygen concentration in the surrounding atmosphere from being too low and to ensure that the electrochemical reaction in the open cathode fuel cell stack 300 proceeds normally.

[0081] In another embodiment of the present application, the relative humidity of the open cathode fuel cell stack 300 is detected by a relative humidity sensor. A relative humidity sensor is installed on the open cathode fuel cell stack 300, and the relative humidity sensor can monitor the relative humidity of the air around the open cathode fuel cell stack 300 in real time ( Figure 1 RH in the figure) to prevent the stack 300 from operating in overly dry air conditions.

[0082] In another embodiment of the present application, a relay is connected to isolate the open cathode fuel cell from the load 330 , and an isolation diode 340 is connected to prevent reverse current between the open cathode fuel cell and the load 330 .

[0083] The temperature control method of the open cathode fuel cell based on FPGA provided in this application is a temperature self-regulating control method with FPGA as the control core, which enables the stack 300 to operate stably within the optimal temperature range. In addition, the adjustment reaction speed is fast and the temperature control is precise, which effectively solves the phenomenon of overshoot oscillation in the hydrothermal control of the fuel cell, makes the working environment of the open cathode fuel cell more stable, and improves the robustness, output performance, service life and reliability of the fuel cell. In actual operation, the effect of changing the temperature of the stack can be achieved by adjusting the relevant parameters of the FPGA controller 20. There is no need to change any structure of the open cathode fuel cell, which maintains the simple auxiliary system and low cost characteristics of the original battery.

[0084] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. An open cathode fuel cell temperature control device based on FPGA, characterized in that: include: a cooling fan connected to the open cathode fuel cell; An FPGA controller is electrically connected to the cooling fan; A first temperature sensor is electrically connected to the FPGA controller to measure the inlet air temperature of the fuel cell stack in real time; A second temperature sensor is electrically connected to the FPGA controller to measure the real-time operating temperature of the fuel cell stack; A current sensor is connected to the open cathode fuel cell and the load to form a loop to measure the stack current; The FPGA controller first determines whether the inlet air temperature is within the allowable operating temperature range, and then calculates the optimal operating temperature of the stack based on the inlet air temperature and the stack current. The FPGA controller adjusts the duty cycle of the cooling fan voltage based on the difference between the real-time stack operating temperature measured by the second temperature sensor and the set optimal operating temperature, and controls the motor speed of the cooling fan through the PWM DC motor speed regulator, thereby adjusting the wind speed of the cooling fan; The temperature control method of an open cathode fuel cell based on FPGA includes the following steps: Detecting the inlet air temperature T of the open cathode fuel cell stack in , the real-time operating temperature of the stack T s And the stack current I s ; Determine the air inlet temperature T in If 10℃≤T in ≤40℃, calculate the optimal operating temperature T of the stack according to the formula opt =0.46I s +33.63; if -20℃≤T in <10℃ or 40℃<T in ≤50℃, calculate the optimal operating temperature T of the stack according to the formula opt =0.53I s +26.01; if T in <-20℃ or T in >50℃, then T in If the permissible operating temperature range is exceeded, the system stops running; Calculate the real-time operating temperature T of the stack s The difference between the optimal operating temperature of the stack and DIF = T s -T opt ; Determine the size of DIF and -LIMIT, where LIMIT is the maximum difference between the actual operating temperature allowed by the fuel cell stack and the optimal stack temperature. If DIF < -LIMIT, the cooling fan connected to the open cathode fuel cell is controlled to run at the minimum wind speed; if DIF ≥ -LIMIT and DIF > LIMIT, the cooling fan is controlled to run at the maximum wind speed; if DIF ≥ -LIMIT and DIF ≤ LIMIT, the duty cycle of the cooling fan voltage is calculated according to the formula Fan n+1 (%) = 100*DIF / (2*LIMIT)+Fan n (%), of which Fan n (%) is the duty cycle of the cooling fan voltage before adjustment, Fan n+1 (%) is the duty cycle of the cooling fan voltage after adjustment. The FPGA controller adjusts the duty cycle of the cooling fan voltage to Fan through the PWM DC motor speed regulator. n+1 (%), PWM DC motor speed regulator controls the motor speed of the cooling fan, thereby adjusting the wind speed of the cooling fan.

2. The FPGA-based open cathode fuel cell temperature control device according to claim 1, characterized in that: The FPGA-based open cathode fuel cell temperature control device includes a sealed fixture, and the heat dissipation fan is sealedly connected to the open cathode fuel cell through the sealed fixture.

3. The FPGA-based open cathode fuel cell temperature control device according to claim 2, characterized in that: The sealed fixture is a shell with a channel in the middle. One end of the shell is connected to the open cathode fuel cell, and the other end of the shell is connected to the heat dissipation fan.

4. The FPGA-based open cathode fuel cell temperature control device according to claim 1, wherein: The cooling fan and the open cathode fuel cell are coordinated in an air suction manner.

5. The FPGA-based open cathode fuel cell temperature control device according to any one of claims 1 to 4, characterized in that: The FPGA-based open cathode fuel cell temperature control device includes a power supply, and the power supply, the FPGA controller, and the cooling fan are connected to form a loop.

6. The FPGA-based open cathode fuel cell temperature control device according to claim 5, characterized in that: The power source is one of a lithium battery, a storage battery, and a supercapacitor; And / or, the cooling fan is a DC axial flow fan or a DC centrifugal fan; And / or, the FPGA-based open cathode fuel cell temperature control device includes an oxygen concentration sensor provided on the open cathode fuel cell stack; And / or, the FPGA-based open cathode fuel cell temperature control device includes a relative humidity sensor provided on the open cathode fuel cell stack; And / or, the FPGA-based open cathode fuel cell temperature control device includes a hydrogen concentration sensor provided on the open cathode fuel cell stack.

7. A temperature control method for an open cathode fuel cell based on FPGA, characterized in that: The following steps are involved: Detecting the inlet air temperature T of the open cathode fuel cell stack in , the real-time operating temperature of the stack T s And the stack current I s ; Determine the air inlet temperature T in If 10℃≤T in ≤40℃, calculate the optimal operating temperature T of the stack according to the formula opt =0.46I s +33.63; if -20℃≤T in <10℃ or 40℃<T in ≤50℃, calculate the optimal operating temperature T of the stack according to the formula opt =0.53I s +26.01; if T in <-20℃ or T in >50℃, then T in If the permissible operating temperature range is exceeded, the system stops running; Calculate the real-time operating temperature T of the stack s The difference between the optimal operating temperature of the stack and DIF = T s -T opt ; Determine the size of DIF and -LIMIT, where LIMIT is the maximum difference between the actual operating temperature allowed by the fuel cell stack and the optimal stack temperature. If DIF < -LIMIT, the cooling fan connected to the open cathode fuel cell is controlled to run at the minimum wind speed; if DIF ≥ -LIMIT and DIF > LIMIT, the cooling fan is controlled to run at the maximum wind speed; if DIF ≥ -LIMIT and DIF ≤ LIMIT, the duty cycle of the cooling fan voltage is calculated according to the formula Fan n+1 (%) = 100*DIF / (2*LIMIT)+Fan n (%), of which Fan n (%) is the duty cycle of the cooling fan voltage before adjustment, Fan n+1 (%) is the duty cycle of the cooling fan voltage after adjustment. The FPGA controller adjusts the duty cycle of the cooling fan voltage to Fan through the PWM DC motor speed regulator. n+1 (%), PWM DC motor speed regulator controls the motor speed of the cooling fan, thereby adjusting the wind speed of the cooling fan.

8. The temperature control method of an open cathode fuel cell based on FPGA according to claim 7, characterized in that: The inlet air temperature T of the open cathode fuel cell stack is detected by the first temperature sensor and the second temperature sensor respectively. in And the real-time operating temperature of the stack T s and the inlet air temperature T in And the real-time operating temperature of the stack T s Feedback to the FPGA controller.

9. The temperature control method of an open cathode fuel cell based on FPGA according to claim 7, characterized in that: The heat dissipation fan achieves heat dissipation by sucking air from the open cathode fuel cell stack.

10. The temperature control method of an open cathode fuel cell based on FPGA according to any one of claims 7 to 9, characterized in that: Controlling the FPGA controller and the cooling fan to start up through an external power supply; and / or, adjusting the inlet hydrogen pressure of the open cathode fuel cell to a range of: 1.2-1.6 bar; and / or, detecting the oxygen concentration of the open cathode fuel cell by an oxygen concentration sensor; and / or, detecting the relative humidity of the open cathode fuel cell stack by a relative humidity sensor; And / or, the hydrogen concentration of the open cathode fuel cell stack is detected by a hydrogen concentration sensor.

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