Fuel cell stack control system and control method

Abstract

A fuel cell stack control system and method, the method includes the steps of: acquiring a temperature of the stack in real time by detection by a temperature sensor, determining whether the stack real time temperature is greater than a first predetermined temperature, and performing a next step if the stack real time temperature is not greater than the first predetermined temperature; acquiring a current of the stack in real time, determining whether a real time current outputted by the stack is greater than a first predetermined current, and performing step 3 if the real time current outputted by the stack is not greater than the first predetermined current; acquiring a voltage of the stack in real time, determining whether a real time voltage outputted by the stack is less than the first predetermined voltage, and adjusting a temperature control assembly to maintain a rotation speed of an initial duty ratio if the real time voltage outputted by the stack is not less than the first predetermined voltage.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to a Chinese patent application having a filing date of March 31, 2022 and application number 202210337877.4, the entire contents of which are incorporated herein by reference. [Technical field]

[0002] The present application relates to the technical field of hydrogen fuel cells, for example, to a fuel cell stack control system and method. [Background technology]

[0003] A fuel cell is a device that directly converts the chemical energy of fuel into electrical energy. Theoretically speaking, if fuel is supplied continuously, fuel cells can generate electricity continuously, and are praised as the fourth generation of power generation technology following hydroelectric, thermal, and nuclear power. Fuel cells have the advantages of high fuel energy conversion rate, low noise, and no emissions, and can be widely used in transportation such as cars, buses, trucks, drones, and motorcycles, as well as backup power sources and fixed power plants.

[0004] Fuel cell stacks release a large amount of heat during operation, and if the generated heat is not discharged in a timely manner, the temperature of the stack will gradually rise. However, fuel cells require an appropriate temperature during use to achieve optimal system performance. If the stack temperature is too low, the catalyst activity will decrease, the output voltage will be low, and the stack performance will be poor. If the stack temperature is too high, the moisture in the proton exchange membrane will be easily volatilized, causing a decrease in the humidity of the proton exchange membrane. If it is too dry, it will cause damage to the proton exchange membrane, reducing the hydrogen ion conduction efficiency of the proton exchange membrane, and further affecting the performance of the fuel cell stack. Therefore, a reasonable temperature is very important, and a cooling system is required to reasonably control the temperature during the operation of the fuel cell.

[0005] In the related art, in the fault diagnosis and treatment methods for fuel cell stacks, when the stack temperature exceeds a predetermined value, it is generally necessary to shut down the stack and then start the fan to cool it down, and perform a shutdown procedure on the fuel cell stack to eliminate the fault, which is time-consuming and labor-intensive and does not meet the requirement of continuous operation of the stack. Summary of the Invention

[0006] The present application provides a fuel cell stack control system and control method that can solve the problem in related art that, when the stack temperature exceeds a predetermined value, it is necessary to shut down the system and then start the fan to cool it down, thereby performing a shutdown procedure on the fuel cell stack to eliminate any faults, which takes time and effort, and makes it difficult to meet the requirement of continuously operating the stack.

[0007] An embodiment of the present application proposes a fuel cell stack control system and a control method, and includes the following four aspects.

[0008] In a first aspect, the present application provides a method for controlling stack temperature, Step 1 of obtaining a temperature of the stack in real time by detecting the temperature sensor, determining whether the stack real time temperature is greater than a first predetermined temperature, and if the stack real time temperature is greater than the first predetermined temperature, adjusting a rotation speed of a temperature control assembly to maintain the stack temperature less than the first predetermined temperature, and if the stack real time temperature is not greater than the first predetermined temperature, executing step 2; Step 2: acquiring a current for a stack in real time, determining whether a real-time current output from the stack is greater than a first predetermined current, and if the real-time current output from the stack is greater than the first predetermined current, linearly adjusting a rotation speed of a temperature control assembly at a duty ratio equal to or less than a predetermined duty ratio according to the magnitude of the current, and if the real-time current output from the stack is not greater than the first predetermined current, performing step 3; and 3. acquiring a voltage for the stack in real time, determining whether a real-time voltage output by the stack is smaller than a first predetermined voltage, and if the real-time voltage output by the stack is smaller than the first predetermined voltage, opening an exhaust valve to exhaust air and blowing air for a predetermined time while maintaining a rotation speed of the temperature control assembly at a predetermined duty ratio, and if the real-time voltage output by the stack is not smaller than the first predetermined voltage, adjusting the temperature control assembly to maintain the rotation speed of an initial duty ratio.

[0009] In one embodiment, step 1 includes: If the stack real-time temperature is greater than a first predetermined temperature, determining whether a temperature detection sensor is operating normally; The method further includes a step of adjusting the rotation speed of the temperature control assembly using a PID when the temperature sensor is operating normally, and causing the temperature control assembly to maintain a current rotation speed and performing step 3 when the temperature sensor is not operating normally.

[0010] In one embodiment, step 2 includes: When the real-time current output by the stack is greater than a first predetermined current, further determining whether the stack real-time temperature is greater than a second predetermined temperature; If the stack real-time temperature is greater than the second predetermined temperature, linearly adjust the rotation speed of the temperature control assembly at a duty ratio equal to or less than a predetermined duty ratio according to the magnitude of the current, and if the stack real-time temperature is not greater than the second predetermined temperature, make the temperature control assembly maintain the current rotation speed and perform step 3; The method further includes a step of determining whether the stack real-time temperature is greater than a first predetermined temperature when the temperature control assembly is adjusted to reach a specific rotation speed at the predetermined duty ratio, and returning to step 1 if the stack real-time temperature is greater than the first predetermined temperature, and if the stack real-time temperature is not greater than the first predetermined temperature, causing the temperature control assembly to maintain the current rotation speed and performing step 3.

[0011] In one embodiment, step 3 comprises: and opening an exhaust valve to exhaust air and to blow air for a predetermined time while maintaining a rotation speed of the temperature control assembly at a predetermined duty ratio, and then determining whether a real-time voltage outputted from the stack is smaller than a first predetermined voltage. The method further includes adjusting an exhaust policy to shorten an exhaust interval if the real-time voltage output by the stack is less than a first predetermined voltage, and adjusting a temperature control assembly to maintain a rotation speed at an initial duty ratio if the real-time voltage output by the stack is not less than the first predetermined voltage.

[0012] In one embodiment, step 3 comprises: After opening the exhaust valve to exhaust air and maintaining the rotation speed of the temperature control assembly at a predetermined duty ratio for a predetermined time, if the real-time voltage output by the stack is still smaller than the first predetermined voltage, obtaining real-time voltages of the single cells and determining whether the voltage of each single cell is within a second predetermined voltage range; When the voltage of each unit cell is within a second predetermined voltage range, the rotation speed of the temperature control assembly is maintained at the initial duty ratio and the stack operates normally, and when the voltage of each unit cell is not within the second predetermined voltage range, the exhaust policy of the temperature control assembly is adjusted to shorten the exhaust interval of the exhaust valve until the stack also operates normally with the temperature control assembly maintaining the rotation speed at the initial duty ratio.

[0013] In one embodiment, the temperature of the stack is detected by the temperature sensor in real time and acquired at a cycle of 0.5 to 2 minutes.

[0014] In one embodiment, the temperature control assembly includes a heat dissipation fan configured to cool the fuel cell stack.

[0015] In a second aspect, the present application further provides a fuel cell stack control system comprising at least one data acquisition unit and at least one control unit, the data acquisition unit comprising: a temperature detection unit electrically connected to the control unit for feeding back a real-time temperature of the stack to the control unit; a current detection unit electrically connected to the control unit for feeding back a real-time current of the stack to the control unit; and a voltage detection unit electrically connected to the control unit for feeding back a real-time voltage of the stack to the control unit, wherein the control unit adjusts the rotation speed of a temperature control assembly based on a data analysis result by comparing and analyzing the real-time data of the data acquisition unit with a first predetermined temperature, a first predetermined current and a first predetermined voltage.

[0016] In one embodiment, a pressure sensor is provided to detect a pressure range of hydrogen gas introduced into the stack, and closes an intake valve of the stack to protect the stack when the pressure range is higher or lower than a predetermined value. a temperature sensor arranged to detect a temperature in the stack, and to protect the stack by turning off the stack if the temperature in the stack is higher or lower than a predetermined value; an intake valve provided in a hydrogen supply line of the stack for controlling the supply amount and discharge frequency of hydrogen gas to the stack; The control system further comprises an exhaust valve provided at an exhaust port of the stack for controlling the amount and frequency of exhaust gas discharged after the reaction in the stack.

[0017] In one embodiment, the control unit is a first determination module for determining whether the stack real-time temperature is greater than a first predetermined temperature, and if the stack real-time temperature is greater than the first predetermined temperature, adjusting a rotation speed of a temperature control assembly to maintain the stack temperature less than the first predetermined temperature, and if the stack real-time temperature is not greater than the first predetermined temperature, executing a second determination module; a second determination module for determining whether a real-time current outputted by the stack is greater than a first predetermined current, and if the real-time current outputted by the stack is greater than the first predetermined current, linearly adjusting a rotation speed of a temperature control assembly at a duty ratio equal to or less than a predetermined duty ratio according to the magnitude of the current, and executing a third determination module if the real-time current outputted by the stack is not greater than the first predetermined current; a third determination module for determining whether a real-time voltage output by the stack is smaller than a first predetermined voltage, and for opening an exhaust valve to exhaust air and for blowing air for a predetermined time while maintaining a rotation speed of a temperature control assembly at a predetermined duty ratio if the real-time voltage output by the stack is not smaller than the first predetermined voltage, and for adjusting the temperature control assembly to maintain the rotation speed of an initial duty ratio.

[0018] In one embodiment, the control unit includes a first voltage detection mechanism configured to detect the output voltage of the entire stack, and a plurality of second voltage detection mechanisms configured to detect real-time voltages of a plurality of single cells, respectively, and the first voltage detection mechanism and the second voltage detection mechanism are each electrically connected to the control unit to feed back the real-time voltage of the stack and the single cell voltage to the control unit.

[0019] The present application relates to a fuel cell stack control system and a control method, and has the following advantageous effects compared to related art. 1. The present application achieves the effect of cooling by timely detecting changes in stack temperature, output current, and output voltage, and adjusting the rotation speed of the temperature control assembly without affecting the normal operation of the stack, thereby ensuring that the fuel cell stack is always used in the optimal temperature range. 2. According to the temperature control method of the present application, when the stack exceeds a predetermined value, there is no need to shut down and then start up the temperature control assembly to cool it down, and there is no need to perform a shutdown procedure on the fuel cell stack to eliminate any faults, and the stack can continue to operate normally. [Brief description of the drawings]

[0020] [Figure 1] 3 is a flowchart of a stack temperature control method according to the first embodiment of the present invention. [Diagram 2] 10 is a diagram showing a fuel cell stack control system according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Example 1 As shown in FIG. 1, FIG. 1 is a flow chart of the stack temperature control method in the first embodiment of the present application, and the stack temperature control method includes the following steps 1, 2 and 3.

[0022] Step 1: Obtain the temperature of the stack in real time by detection by a temperature sensor, and determine whether the stack real-time temperature is greater than a first predetermined temperature. If the stack real-time temperature is greater than the first predetermined temperature, adjust the rotation speed of the temperature control assembly to maintain the stack temperature less than the first predetermined temperature. If the stack real-time temperature is not greater than the first predetermined temperature, execute step 2.

[0023] Specifically, a temperature sensor attached to the stack provides real-time temperature acquisition for the stack. When the temperature of the cell stack is too high, it directly affects the performance and life of the fuel cell, so the processing unit adjusts the rotation speed of the temperature control assembly to cool the fuel cell stack when the received feedback temperature exceeds a preset first predetermined temperature. Since the first predetermined temperature is generally lower than the temperature at which shutdown protection is performed, direct shutdown due to too high stack temperature is avoided. According to the above-mentioned method, the rotation speed of the temperature control assembly can be adjusted early just before the temperature of the stack rises, thereby improving heat dissipation efficiency and ensuring that the fuel cell stack is in an optimal temperature range. In this embodiment, the temperature of the stack is reduced by air cooling, so that the temperature control assembly includes a heat dissipation fan for reducing the temperature of the fuel cell stack.

[0024] In this embodiment, the first predetermined temperature may be, but is not limited to, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, 50°C. Because the first predetermined temperature is generally lower than the temperature at which shutdown protection is executed, it is necessary to detect temperature changes in the stack in a timely manner, so that the temperature sensor requires high detection accuracy and sensitivity. If the temperature sensor makes an incorrect judgment, it is likely to cause a rapid temperature rise in the entire stack, affecting the normal operation of the stack. Therefore, step 1 further includes a step of determining whether the temperature detection sensor is operating normally if the stack real-time temperature is greater than a first predetermined temperature, and a step of adjusting the rotation speed of the temperature control assembly using a PID if the stack real-time temperature is greater than the first predetermined temperature, and a step of causing the temperature control assembly to maintain the current rotation speed and executing step 3 if the stack real-time temperature is not greater than the first predetermined temperature.

[0025] Here, the above PID adjustment involves correcting the rotation speed of the temperature control assembly according to the stack temperature. If the actual measured stack temperature deviates from the plan, the temperature is corrected based on a rating or standard, thereby effectively correcting the deviation of the controlled object and keeping the stack temperature stable.

[0026] There are various means for determining whether the temperature detection sensor is operating normally. Among them, when the temperature detection sensor is damaged, the circuit may be open circuit or short circuit, and the temperature detected at this time is the two limit values ​​of the range, and it can be determined whether the temperature detection sensor is damaged or not by using these values. In addition, in order to improve the accuracy of the temperature sensor, the following means can be used for verification. For example, a spare temperature sensor is installed at the same time, and the difference between the two is calculated. If the difference is within a predetermined range, it can be considered that the temperature sensor is operating normally. Alternatively, since the temperature acquisition period for each time is fixed (the period for acquiring the temperature of the stack in real time by the detection by the temperature sensor is 0.5 to 2 minutes, and in one embodiment, the acquisition period is 1 minute), and the temperature change range should be within a certain range, the change trend of the stack is determined by the closest 3 to 5 consecutive sampled temperatures, and it can be determined whether the detected temperature is opposite to the change trend to determine whether the temperature detection sensor is operating normally.

[0027] Step 2: Obtain a current for the stack in real time, and determine whether the real-time current output by the stack is greater than a first predetermined current. If the real-time current output by the stack is greater than the first predetermined current, linearly adjust the rotation speed of the temperature control assembly at or below a predetermined duty ratio according to the magnitude of the current; if the real-time current output by the stack is not greater than the first predetermined current, execute step 3.

[0028] Generally speaking, one of the main causes of heat generation in the stack is abnormal output current of the stack; if the load on the stack is too large, the current output by the stack will be correspondingly large. In order to predict the change trend of the stack temperature early, in this embodiment, the real-time current output by the stack is detected to predict the heat generation situation of the stack, and measures can be taken early to ensure that the fuel cell stack is in the optimal temperature range.

[0029] Also, when the real-time current outputted by the stack is greater than the first predetermined current, it is further determined whether the stack real-time temperature is greater than a second predetermined temperature. If the stack real-time temperature is greater than the second predetermined temperature, the rotation speed of the temperature control assembly is linearly adjusted at a predetermined duty ratio or less according to the magnitude of the current, and if the stack real-time temperature is not greater than the second predetermined temperature, the temperature control assembly is made to maintain the current rotation speed, and step 3 is executed. After the temperature control assembly is adjusted to a specific rotation speed at the predetermined duty ratio, it is further determined whether the stack real-time temperature is greater than the first predetermined temperature, and if the stack real-time temperature is greater than the first predetermined temperature, the process returns to step 1, and if the stack real-time temperature is not greater than the first predetermined temperature, the temperature control assembly is made to maintain the current rotation speed, and step 3 is executed.

[0030] Here, the second predetermined temperature needs to be lower than the first predetermined temperature, and the second predetermined temperature may be, but is not limited to, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C. At this time, the temperature is between the first predetermined temperature and the second predetermined temperature and is a relatively safe temperature, so that the temperature can be quickly corrected by linearly adjusting the duty ratio of the temperature reduction assembly. Here, the predetermined duty ratio is related to the real-time current output by the stack, and generally, when the current increases, the predetermined duty ratio p also increases accordingly, and when the current decreases, the predetermined duty ratio p1 also decreases accordingly. In other words, a predetermined duty ratio p1 is linearly adjusted according to the magnitude of the current, and the adjustment of the duty ratio realizes the adjustment of the rotation speed of the temperature control assembly. (Here, the duty ratio is the ratio of the time that the load or circuit is on to the time that the load or circuit is off. The duty ratio is sometimes called the "duty cycle" and is expressed as a percentage of the on time. A signal with a duty ratio of 60% is on for 60% of the time and off for another 40% of the time.)

[0031] Step 3: Obtain a voltage for the stack in real time, and determine whether the real-time voltage output by the stack is less than a first predetermined voltage. If the real-time voltage output by the stack is less than the first predetermined voltage, open an exhaust valve to exhaust air and blow air for a predetermined time while maintaining a rotation speed of the temperature control assembly at a predetermined duty ratio p1. If the real-time voltage output by the stack is not less than the first predetermined voltage, adjust the temperature control assembly to maintain the rotation speed at an initial duty ratio p2.

[0032] The exhaust policy of the air-cooled stack affects the performance and hydrogen gas utilization rate of the stack during operation. If the exhaust time is too short and the exhaust interval is too long, the fuel inside the stack will be insufficient, which may cause a polarity reversal phenomenon in the cells, as well as an abnormal rise in temperature, which may lead to a stack ignition. If the exhaust time is too long and the exhaust interval is too short, a large amount of unreacted hydrogen gas will be discharged to the outside of the stack, which will reduce the utilization rate of hydrogen gas and reduce the economical effect of hydrogen gas. The stack is the place where the electrochemical reaction occurs and is also the core part of the fuel cell power system, and is composed of a combination of multiple single cells stacked in series. By acquiring the voltage of the stack, this embodiment can reflect the basic situation of multiple single cells as a whole. When the real-time current output by the stack is smaller than the first predetermined voltage, there may be a polarity reversal phenomenon or a tendency for a polarity reversal phenomenon to occur, and by timely discovering the polarity reversal phenomenon of some single cells, it ensures that the fuel cell stack is in the optimal temperature range.

[0033] Therefore, after opening the exhaust valve to exhaust and blowing for a predetermined time while maintaining the rotation speed of the temperature control assembly at a predetermined duty ratio p1, it is further determined whether the real-time voltage output from the stack is smaller than a first predetermined voltage, and if the real-time voltage output from the stack is smaller than the first predetermined voltage, the exhaust policy is adjusted to shorten the exhaust interval, and if the real-time voltage output from the stack is not smaller than the first predetermined voltage, the temperature control assembly is adjusted to maintain the rotation speed at the initial duty ratio p2. By adjusting the exhaust policy, the polarity reversal phenomenon of the single cell is avoided.

[0034] Compared with obtaining the voltage of the entire hydrogen fuel cell stack, the voltage of each unit cell can be obtained continuously in real time to more accurately determine whether a polarity reversal phenomenon has occurred. After performing the blowing for a predetermined time while opening the exhaust valve to exhaust and maintaining the rotation speed of the temperature control assembly at a predetermined duty ratio p1, if the real-time current output from the stack is still smaller than the first predetermined voltage, obtain the real-time voltage of the unit cell, determine whether the voltage of each unit cell is within a second predetermined voltage range, and if the voltage of each unit cell is within the second predetermined voltage range, maintain the rotation speed of the temperature control assembly at the initial duty ratio p2, and the stack operates normally. If the voltage of each unit cell is not within the second predetermined voltage range, adjust the exhaust policy of the temperature control assembly and shorten the exhaust interval of the exhaust valve until the stack still operates normally while maintaining the rotation speed of the temperature control assembly at the initial duty ratio p2. If it is determined that the voltage of a certain unit cell is negative, adjust the exhaust policy of the temperature control assembly and shorten the exhaust interval of the exhaust valve, so that the stack can be automatically repaired and the fault can be eliminated. Example 2

[0035] Based on the same inventive concept as the stack temperature control method in the above embodiment 1, the present application further provides a fuel cell stack control system, as shown in FIG. 2, the control system includes at least one data acquisition unit and at least one control unit.

[0036] Here, the data acquisition unit includes a temperature detection unit electrically connected to the control unit and feeding back a real-time temperature of the stack to the control unit, a current detection unit electrically connected to the control unit and feeding back a real-time current of the stack to the control unit, and a voltage detection unit electrically connected to the control unit and feeding back a real-time voltage of the stack to the control unit.

[0037] The control unit adjusts the rotation speed of the temperature control assembly based on the data analysis result by comparing and analyzing the real-time data of the data acquisition unit with a first predetermined temperature, a first predetermined current, and a first predetermined voltage.

[0038] Further, the control system a pressure sensor that is provided to detect a pressure range of hydrogen gas introduced into the stack, and when the pressure range is higher or lower than a predetermined value, closes an intake valve of the stack to protect the stack and prevent the membrane electrode from being punched through; a temperature sensor arranged to detect a temperature within the stack, and if the temperature is above or below a predetermined value, to turn off the stack to protect the stack and prevent irreversible damage to the stack; an intake valve provided in a hydrogen supply line of the stack to control the amount of hydrogen gas supplied to the stack and the frequency of discharge; The stack further includes an exhaust valve provided at an exhaust port of the stack for controlling the amount and frequency of exhaust gas discharged after the reaction in the stack.

[0039] In one embodiment, the control system includes a first determination module for determining whether the stack real-time temperature is greater than a first predetermined temperature, and if the stack real-time temperature is greater than the first predetermined temperature, adjusting a rotation speed of a temperature control assembly to maintain the stack temperature less than the first predetermined temperature, and if the stack real-time temperature is not greater than the first predetermined temperature, executing a second determination module; and a second determination module for determining whether a real-time current outputted by the stack is greater than a first predetermined current, and if the real-time current outputted by the stack is greater than the first predetermined current, adjusting a duty ratio p1 or more according to a magnitude of the current. a second judgment module for linearly adjusting the rotation speed of the temperature control assembly under the condition that the real-time current output by the stack is not greater than a first predetermined current, and a third judgment module for determining whether a real-time voltage output by the stack is smaller than a first predetermined voltage, the third judgment module for opening an exhaust valve to exhaust air and blow air for a predetermined time while maintaining the rotation speed of the temperature control assembly at a predetermined duty ratio p1 if the real-time voltage output by the stack is smaller than the first predetermined voltage, and for adjusting the temperature control assembly to maintain the rotation speed of the initial duty ratio if the real-time voltage output by the stack is not smaller than the first predetermined voltage.

[0040] In one embodiment, the control system further includes a first voltage detection mechanism configured to detect the output voltage of the entire stack, and a plurality of second voltage detection mechanisms configured to detect real-time voltages of a plurality of single cells, respectively, and the first voltage detection mechanism and the second voltage detection mechanism are each electrically connected to the control unit to feed back the real-time voltage of the stack and the single cell voltage to the control unit.

[0041] In one embodiment, the control system further includes a fourth judgment module for determining whether a temperature detection sensor is operating normally when the stack real-time temperature is greater than a first predetermined temperature, and for adjusting the rotation speed of the temperature control assembly using a PID if the temperature detection sensor is operating normally, and for making the temperature control assembly maintain the current rotation speed and perform step 3 if the temperature detection sensor is not operating normally.

[0042] In one embodiment, the control system further includes a fifth judgment module for judging whether the stack real-time temperature is greater than a second predetermined temperature when the real-time current outputted by the stack is greater than a first predetermined current, When the stack real-time temperature is greater than a second predetermined temperature, linearly adjust the rotation speed of the temperature control assembly at or below a predetermined duty ratio p1 according to the magnitude of the current; a fifth judgment module for determining whether the stack real-time temperature is greater than the first predetermined temperature when the stack real-time temperature is not greater than the second predetermined temperature, and for executing step 3, and for adjusting the temperature control assembly to reach the specific rotation speed at the predetermined duty ratio p1, and for determining whether the stack real-time temperature is greater than the first predetermined temperature when the stack real-time temperature is greater than the first predetermined temperature, and for returning to step 1 when the stack real-time temperature is greater than the first predetermined temperature; The fifth judgment module is configured to cause the temperature control assembly to maintain the current rotation speed and execute step 3 if the stack real-time temperature is not greater than the first predetermined temperature.

[0043] In one embodiment, the control system further includes a sixth judgment module for judging whether a real-time voltage outputted from the stack is less than a first predetermined voltage after opening an exhaust valve to exhaust air and maintaining a rotation speed of the temperature control assembly at a predetermined duty ratio p1 for a predetermined time, the sixth judgment module further comprising: The sixth judgment module further includes a sixth judgment module that adjusts the exhaust policy and shortens the exhaust interval when the real-time voltage output by the stack is less than the first predetermined voltage, and adjusts the temperature control assembly to maintain the rotation speed at the initial duty ratio when the real-time voltage output by the stack is not less than the first predetermined voltage.

[0044] In one embodiment, the control system further includes a seventh determination module for obtaining a real-time voltage of each unit cell and determining whether the voltage of each unit cell is within a second predetermined voltage range when the real-time current output from the stack is still smaller than the first predetermined voltage after opening an exhaust valve to exhaust air and maintaining a rotation speed of the temperature control assembly at a predetermined duty ratio p1 for a predetermined time, The stack further includes a seventh judgment module that, when the voltage of each unit cell is within a second predetermined voltage range, maintains the rotation speed of the temperature control assembly at the initial duty ratio p2, and operates normally, and, when the voltage of each unit cell is not within the second predetermined voltage range, adjusts the exhaust policy of the temperature control assembly and shortens the exhaust interval of the exhaust valve until the stack also operates normally with the temperature control assembly maintaining the rotation speed of the initial duty ratio p2.

[0045] Various variations and specific examples of the stack temperature control method in the above Example 1 can be similarly applied to the fuel cell stack control system of this embodiment, and based on the detailed description of the stack temperature control method described above, those skilled in the art can clearly understand how to implement the stack temperature control device in this embodiment, so for the sake of brevity, detailed descriptions will be omitted here.

[0046] The present application achieves the effect of cooling by timely determining changes in stack temperature, output current, and output voltage, and adjusts the rotation speed of the temperature control assembly without affecting the normal operation of the stack, thereby ensuring that the fuel cell stack is always used in the optimal temperature range.

[0047] According to the temperature control method of the present invention, it is not necessary to shut down the fuel cell stack when the stack exceeds a predetermined value and then start up the temperature control assembly to cool it down, and it is not necessary to perform a shutdown process on the fuel cell stack to eliminate any faults, and the stack can continue to operate normally.

Claims

1. Step 1: obtaining a temperature of the stack in real time by detecting the temperature sensor, determining whether the stack real time temperature is greater than a first predetermined temperature, and if the stack real time temperature is greater than the first predetermined temperature, adjusting a rotation speed of a temperature control assembly to maintain the stack temperature less than the first predetermined temperature, and if the stack real time temperature is not greater than the first predetermined temperature, executing step 2; Step 2: acquiring a current for a stack in real time, determining whether the real-time current output from the stack is greater than a first predetermined current, and if the real-time current output from the stack is greater than the first predetermined current, linearly adjusting a rotation speed of a temperature control assembly at a duty ratio equal to or less than a predetermined duty ratio according to the magnitude of the current, and if the real-time current output from the stack is not greater than the first predetermined current, performing step 3; acquiring a voltage for the stack in real time, determining whether the real-time voltage output by the stack is smaller than a first predetermined voltage, and if the real-time voltage output by the stack is smaller than the first predetermined voltage, opening an exhaust valve to exhaust air and blow air for a predetermined time while maintaining a rotation speed of a temperature control assembly at a predetermined duty ratio, and if the real-time voltage output by the stack is not smaller than the first predetermined voltage, adjusting the temperature control assembly to maintain the rotation speed of an initial duty ratio.

2. The step 1 includes: If the stack real-time temperature is greater than a first predetermined temperature, determining whether a temperature detection sensor is operating normally; 2. The temperature control method of claim 1, further comprising the steps of: adjusting the rotation speed of the temperature control assembly by PID when the temperature sensor is operating normally; and causing the temperature control assembly to maintain a current rotation speed when the temperature sensor is not operating normally, and executing step 3.

3. Step 2 includes: When the real-time current output by the stack is greater than a first predetermined current, further determining whether the stack real-time temperature is greater than a second predetermined temperature; If the stack real-time temperature is greater than the second predetermined temperature, linearly adjust the rotation speed of the temperature control assembly at a duty ratio equal to or less than a predetermined duty ratio according to the magnitude of the current, and if the stack real-time temperature is not greater than the second predetermined temperature, make the temperature control assembly maintain the current rotation speed, and perform step 3; 2. The temperature control method of claim 1, further comprising the steps of: when the temperature control assembly is adjusted to reach a specific rotational speed at the predetermined duty ratio, determining whether the stack real-time temperature is greater than a first predetermined temperature; if the stack real-time temperature is greater than the first predetermined temperature, returning to step 1; and if the stack real-time temperature is not greater than the first predetermined temperature, causing the temperature control assembly to maintain the current rotational speed and executing step 3.

4. Step 3 includes: and opening an exhaust valve to exhaust air and to blow air for a predetermined time while maintaining a rotation speed of the temperature control assembly at a predetermined duty ratio, and then determining whether a real-time voltage outputted from the stack is smaller than a first predetermined voltage.

2. The temperature control method of claim 1, further comprising the steps of: adjusting an exhaust policy and shortening an exhaust interval if the real-time voltage output by the stack is less than a first predetermined voltage; and adjusting a temperature control assembly to maintain a rotation speed at an initial duty ratio if the real-time voltage output by the stack is not less than the first predetermined voltage.

5. Step 3 includes: After opening the exhaust valve to exhaust air and maintaining the rotation speed of the temperature control assembly at a predetermined duty ratio for a predetermined time, if the real-time voltage output by the stack is still smaller than the first predetermined voltage, obtaining real-time voltages of the unit cells and determining whether the voltage of each unit cell is within a second predetermined voltage range; 5. The temperature control method of claim 4, further comprising the steps of: when the voltage of each unit cell is within a second predetermined voltage range, maintaining the rotation speed of the temperature control assembly at the initial duty ratio, and the stack operates normally; and when the voltage of each unit cell is not within the second predetermined voltage range, adjusting the exhaust policy of the temperature control assembly and shortening the exhaust interval of the exhaust valve until the stack also operates normally with the temperature control assembly maintaining the rotation speed at the initial duty ratio.

6. 2. The method for controlling the temperature of a fuel cell stack according to claim 1, wherein the temperature of the stack is detected by the temperature sensor in real time at a period of 0.5 to 2 minutes.

7. 2. The method of claim 1, wherein the temperature control assembly comprises a heat dissipation fan arranged to cool the fuel cell stack.

8. At least one data acquisition unit and at least one control unit, The data acquisition unit includes: a temperature detection unit electrically connected to the control unit to feed back a stack real-time temperature to the control unit; a current detection unit electrically connected to the control unit to feed back a real-time current of the stack to the control unit; a voltage detection unit electrically connected to the control unit to feed back a real-time voltage of the stack to the control unit; A fuel cell stack control system, wherein the control unit adjusts the rotation speed of the temperature control assembly based on the data analysis results by comparing and analyzing the real-time data of the data acquisition unit with a first predetermined temperature, a first predetermined current, and a first predetermined voltage.

9. a pressure sensor for detecting a pressure range of hydrogen gas introduced into the stack, and for closing an intake valve of the stack to protect the stack when the pressure range is higher or lower than a predetermined value; a temperature sensor arranged to detect a temperature in the stack, and to protect the stack by turning off the stack if the temperature in the stack is higher or lower than a predetermined value; an intake valve provided in a hydrogen supply line of the stack for controlling the supply amount and discharge frequency of hydrogen gas to the stack; 9. The fuel cell stack control system according to claim 8, further comprising an exhaust valve provided at an exhaust port of the stack for controlling the amount and frequency of exhaust gas discharged after the reaction in the stack.

10. The control unit a first determination module for determining whether the stack real-time temperature is greater than a first predetermined temperature, and if the stack real-time temperature is greater than the first predetermined temperature, adjusting a rotation speed of a temperature control assembly to maintain the stack temperature less than the first predetermined temperature, and if the stack real-time temperature is not greater than the first predetermined temperature, executing a second determination module; a second determination module for determining whether a real-time current outputted by the stack is greater than a first predetermined current, and if the real-time current outputted by the stack is greater than the first predetermined current, linearly adjusting a rotation speed of a temperature control assembly at a duty ratio equal to or less than a predetermined duty ratio according to a magnitude of the current, and executing a third determination module if the real-time current outputted by the stack is not greater than the first predetermined current; 10. The fuel cell stack control system of claim 8, further comprising: a third determination module for determining whether a real-time voltage output from the stack is smaller than a first predetermined voltage, the third determination module opening an exhaust valve to exhaust air and blowing air for a predetermined time while maintaining a rotation speed of a temperature control assembly at a predetermined duty ratio if the real-time voltage output from the stack is not smaller than the first predetermined voltage, and adjusting the temperature control assembly to maintain a rotation speed of an initial duty ratio.

11. 9. The fuel cell stack control system of claim 8, wherein the control unit comprises a first voltage detection mechanism configured to detect the output voltage of the entire stack, and a plurality of second voltage detection mechanisms configured to detect real-time voltages of a plurality of single cells, each of the first voltage detection mechanism and the second voltage detection mechanism being electrically connected to the control unit and feeding back the real-time stack voltage and the single cell voltage to the control unit.

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