Temperature control method for fuel cell system

Abstract

The invention relates to the technical field of fuel cells, in particular to a temperature control method of a fuel cell system. The battery system comprises a main air path, an air cooling air path and a bypass air path, the air cooling air path exchanges heat in front of a circulating pump and then is merged into the main air path to form a mixed air path, and the bypass air path and the mixed air path are mixed again and then enter an electric pile; the temperature control method comprises the following steps: when the inlet temperature of the electric pile does not meet the requirement, adjusting the flow of the bypass air path; when the outlet temperature of the electric pile does not meet the requirement, the flow of the main air path is adjusted; and when the inlet temperature of the circulating pump does not meet the requirement, the flow of the air cooling air channel is adjusted. Through combined regulation and control, accurate control of the inlet and outlet temperature of the electric pile and the inlet temperature of the circulating pump is realized, overtemperature is prevented, the electric pile and the circulating pump are protected, the cost is reduced, and the reliability and stability of the system are improved, so that the optimal operation performance of the system is ensured and the service life is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a temperature control method for a fuel cell system. Background Art

[0002] Fuel cell power generation system is a highly efficient energy conversion technology that converts chemical energy directly into electrical energy, and is widely used in the fields of automobiles, stationary power stations, etc. The working principle of the fuel cell system is based on electrochemical reactions, in which fuel (such as hydrogen) and oxygen react in the stack to generate water and electricity.

[0003] The inlet temperature of the fuel cell stack affects the initial reaction conditions and heat exchange efficiency of the fuel cell stack, while the outlet temperature of the fuel cell stack reflects the overall thermal state and thermal management efficiency inside the fuel cell stack. Both need to be controlled within an appropriate range to ensure the optimal activity of the catalyst and the stable operation of the fuel cell stack. In addition, for the medium-temperature circulation system, there is no condensation in the system. If the inlet temperature of the circulation pump is too high, it will damage the components of the circulation pump. The existing fuel cell system does not consider the effective control of the inlet and outlet temperatures of the fuel cell stack and the inlet temperature of the circulation pump, which may lead to degradation of the performance of the fuel cell stack and damage to the circulation pump. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of an embodiment of the present invention is to provide a temperature control method for a fuel cell system, aiming to solve the problem of insufficient temperature control in the prior art. Through joint regulation, precise control of the inlet and outlet temperatures of the fuel cell stack and the inlet temperature of the circulation pump can be achieved to prevent overheating, protect the fuel cell stack and the circulation pump, reduce costs, and improve the reliability and stability of the system to ensure the optimal operating performance of the system and extend its service life.

[0005] In order to achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0006] A temperature control method for a fuel cell system, the battery system comprising a main air path, an air-cooling air path and a bypass air path, the air-cooling air path being merged into the main air path after heat exchange in front of a circulation pump to form a mixed air path, the bypass air path and the mixed air path being mixed again before entering a fuel cell stack; the temperature control method comprising: when the fuel cell stack inlet temperature does not meet the requirements, adjusting the flow of the bypass air path; when the fuel cell stack outlet temperature does not meet the requirements, adjusting the flow of the main air path; when the circulation pump inlet temperature does not meet the requirements, adjusting the flow of the air-cooling air path.

[0007] Optionally, stack inlet temperature control includes:

[0008] Obtain the stack inlet temperature T1, determine the relationship between T1 and the safety threshold T1max of the stack inlet temperature, and calculate the temperature difference ΔT1=T1-T1max; when ΔT1≤0, maintain the existing operating state and keep the stack inlet temperature within a safe range; when ΔT1>0, increase the bypass air flow until the stack inlet temperature T1 drops below T1max.

[0009] Optional circulation pump inlet temperature control includes:

[0010] The stack outlet temperature Tout is obtained. When Tout deviates from the preset required temperature Toutx, the main air flow is adjusted according to the relationship between the stack outlet temperature Tout and the stack inlet temperature T1.

[0011] Optionally, when the stack outlet temperature Tout>the preset required temperature Toutx, if the stack outlet temperature Tout<the stack inlet temperature T1, the main air flow rate is reduced; if the stack outlet temperature Tout>the stack inlet temperature T1, the main air flow rate is increased; if the stack outlet temperature Tout=the stack inlet temperature T1, the bypass air flow rate is increased.

[0012] Optionally, when the stack outlet temperature Tout<the preset required temperature Toutx, if the stack outlet temperature Tout<the stack inlet temperature T1, the main air flow rate is increased; if the stack outlet temperature Tout>the stack inlet temperature T1, the main air flow rate is reduced; if the stack outlet temperature Tout=the stack inlet temperature T1, the bypass air flow rate is reduced.

[0013] Optional circulation pump inlet temperature control includes:

[0014] Obtain the circulating pump inlet temperature T2, determine the relationship between T2 and the safety threshold value T2max of the circulating pump inlet temperature, and calculate the temperature difference ΔT2=T2-T2max; when ΔT2≤0, maintain the existing operating state, and keep the circulating pump inlet temperature within a safe range; when ΔT2>0, increase the air cooling air flow rate, and adjust the cold air flow rate entering the mixer until the circulating pump inlet temperature T2 drops below T2max.

[0015] Optionally, a first temperature sensor is provided on the pipeline in front of the fuel cell stack, a third temperature sensor is provided on the pipeline behind the fuel cell stack, and a second temperature sensor is provided on the pipeline in front of the circulating pump. The first temperature sensor is used to obtain the inlet temperature of the fuel cell stack, the third temperature sensor is used to obtain the outlet temperature of the fuel cell stack, and the second temperature sensor is used to obtain the inlet temperature of the circulating pump.

[0016] Optionally, the bypass air passage is provided with a first fan and a first flowmeter, the main air passage is provided with a second fan and a second flowmeter, and the air-cooling air passage is provided with a third fan and a third flowmeter. The flow of the main air passage is provided by the second fan and detected by the second flowmeter, the flow of the bypass air passage is provided by the first fan and detected by the first flowmeter, and the flow of the air-cooling air passage is provided by the third fan and detected by the third flowmeter.

[0017] Optionally, the fan flows of the three routes are all feedback controlled, the control quantity is a pulse width modulation signal, and the feedback quantity is the air flow meter reading of the corresponding route. By adjusting the duty cycle of the pulse width modulation, the air flow meter reading of each route is made consistent with the corresponding required air volume.

[0018] Optionally, when the fan pressure ratio is greater than a first predetermined value, the system reports a fan pressure ratio maximum fault and triggers a system shutdown; when the absolute error between the actual fan speed and the speed demand value exceeds the allowable deviation, the system shutdown is triggered.

[0019] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0020] 1. This temperature control method adjusts the inlet temperature of the stack by controlling one cold air bypass, which can prevent the stack from overheating, improve the performance of the stack, and avoid stack attenuation; by controlling another cold air bypass to enter the air cooler to adjust the inlet gas temperature of the circulating pump, it can avoid exceeding the operating temperature of the circulating pump and affecting the performance of the circulating pump; when the PID control of the system deviates during startup, stable operation, and shutdown, the air flow of the main air path is adjusted to adjust the temperature deviation to protect the stack. Through joint control, the precise control of the inlet and outlet temperatures of the stack and the inlet temperature of the circulating pump can be achieved to prevent overheating, protect the stack and the circulating pump, reduce costs, and improve the reliability and stability of the system to ensure the best operating performance of the system and extend its service life.

[0021] 2. Set the corresponding calibration limit according to the fan performance. When the threshold is exceeded, the controller will report the corresponding fault and take corresponding measures to avoid damage to the system and components.

[0022] Advantages of additional aspects of the present invention will be given in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In addition, the spacing or size between each other is exaggerated to show the position of each part, and the schematic diagram is only used for illustration.

[0024] Figure 1 is a schematic diagram of a fuel cell system provided by an embodiment of the present invention;

[0025] In the figure: 1, first fan; 2, second fan; 3, third fan; 4, first flow meter; 5, second flow meter; 6, third flow meter; 7, first mixer; 8, air preheater; 9, second mixer; 10, third temperature sensor; 11, first temperature sensor; 12, fuel cell stack; 13, burner; 14, heat exchanger; 15, air cooler; 16, second temperature sensor; 17, circulation pump; 18, third mixer; DETAILED DESCRIPTION

[0026] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0027] Terminology explanation:

[0028] Fuel cell: A chemical device that directly converts the chemical energy of fuel into electrical energy, also known as an electrochemical generator.

[0029] Air cooler: short for air cooler, a heat exchanger that uses ambient air as a cooling medium to cool or condense the high-temperature fluid in the equipment.

[0030] Temperature control of the stack is essential to maintain catalyst activity, prevent performance degradation, and protect key components such as the circulation pump. If the inlet temperature of the stack is too high, the catalyst in the stack will be deactivated, which will lead to stack performance degradation. This is because high temperature may damage the structure of the catalyst and reduce its catalytic activity. If the inlet temperature of the stack is too low, the stack will not be able to reach the optimal operating state. This will affect the rate and efficiency of the electrochemical reaction, thereby reducing the power generation efficiency of the stack. The stack outlet temperature directly reflects the heat accumulation and thermal management efficiency inside the stack. Excessive outlet temperature will cause water volatilization on the proton exchange membrane, resulting in reduced humidity of the proton exchange membrane, increased membrane resistance, and reduced hydrogen ion transfer efficiency, thereby affecting the performance of the stack. In addition, excessive outlet temperature may also cause local hot spots, resulting in deactivation of catalysts in the stack and causing stack degradation. The outlet temperature is an important indicator of the operating status of the stack. Excessive outlet temperature may indicate that there is an overheating problem inside the stack, which needs to be adjusted by the cooling system.

[0031] For ease of understanding, the fuel cell system is first introduced, such as Figure 1 The figure shows a low-power fuel cell power generation system, which mainly includes a gas side and an air side.

[0032] The gas side adopts a medium-temperature circulation method. The main working process is that the imported fuel enters the heat exchanger 14 for preheating and then enters the fuel cell stack 12 for power generation. The high-temperature fuel at the outlet of the fuel cell stack 12 enters the heat exchanger 14 and is divided into two streams. One part enters the burner 13 for combustion, and the high-temperature exhaust gas enters the air preheater 8 to heat the cold air and then enters the exhaust gas exhaust system; the other part first passes through the air cooler 15 for cooling and then enters the circulation pump 17. The fuel circulated back by the circulation pump 17 is mixed with the imported fuel in the third mixer 18 and then enters the heat exchanger 14.

[0033] The main working process of the air side is as follows: the inlet cold air is divided into three routes, the main air route, the air cooling air route and the bypass air route. The main air route is used to transmit the mainstream air flow in the battery system, and includes the second fan 2 and the second flow meter 5. The air cooling air route is used to cool the inlet of the circulation pump 17, and forms a mixed air route after heat exchange. The bypass air route plays the role of adjusting the inlet temperature of the battery stack 12 to ensure the temperature of the battery stack 12 is stable.

[0034] Since this system adopts medium-temperature circulation without condensation, it is limited by the working temperature of the circulation pump 17, and the fuel in front of the circulation pump 17 needs to be cooled by cold air bypass. The air bypass controlled by the third fan 3 enters the air cooler 15 to cool the fuel in front of the circulation pump 17, and then enters the first mixer 7 to mix with the main air. The mixed main air is heated by the air preheater 8. The heated hot air is mixed with another bypass cold air in the second mixer 9. After reaching the specified temperature, it enters the fuel stack 12. The hot air at the outlet of the fuel stack 12 directly enters the burner 13 to provide oxygen for the combustion reaction.

[0035] like Figure 1 As shown, the upper bypass air passage is provided with a first fan 1 and a first flowmeter 4, the middle main air passage is provided with a second fan 2 and a second flowmeter 5, and the lower air cooling air passage is provided with a third fan 3 and a third flowmeter 6. The flow of the main air passage is provided by the second fan 2 and detected by the second flowmeter 5, the flow of the bypass air passage is provided by the first fan 1 and detected by the first flowmeter 4, and the flow of the air cooling air passage is provided by the third fan 3 and detected by the third flowmeter 6. Through the cooperation of the fan and the flowmeter, the air flow of each air passage can be accurately controlled to meet the temperature requirements of the battery system.

[0036] A plurality of temperature sensors are arranged on the pipeline of the battery system for real-time monitoring of temperature data. A first temperature sensor 11 is arranged on the pipeline in front of the battery stack 12, a third temperature sensor 10 is arranged on the pipeline behind the battery stack 12, and a second temperature sensor 16 is arranged on the pipeline in front of the circulating pump 17. The first temperature sensor 11 is used to obtain the inlet temperature of the battery stack 12, the third temperature sensor 10 is used to obtain the outlet temperature of the battery stack 12, and the second temperature sensor 16 is used to obtain the inlet temperature of the circulating pump 17. These temperature sensors monitor and feedback data in real time, provide necessary inputs for the temperature control system, and make the temperature control process more accurate.

[0037] When the system is started, it is first necessary to introduce direct fuel into the burner 13, and the second fan 2 is enabled to provide an oxygen source for the combustion reaction. The combustion of the burner 13 provides heat for the entire system. The total air volume of the fan is equal to the sum of the main air flow (second fan 2), the bypass air flow (first fan 1) entering the second mixer 9, and the air cooling air flow (third fan 3) entering the first mixer 7. The bypass air flow entering the second mixer 9 is obtained by the air inlet temperature control of the fuel cell stack 12, and the air cooling air flow entering the first mixer 7 is obtained by the fuel inlet temperature control of the circulating pump 17.

[0038] The temperature control method of the above-mentioned fuel cell system includes: when the inlet temperature of the fuel cell stack 12 does not meet the requirements, adjusting the flow of the bypass air path; when the outlet temperature of the fuel cell stack 12 does not meet the requirements, adjusting the flow of the main air path; when the inlet temperature of the circulating pump 17 does not meet the requirements, adjusting the flow of the air-cooling air path.

[0039] The cold air bypass cooperates with the mixer to control the inlet and outlet temperatures of the stack 12 and the circulating pump 17 to prevent overheating. When there is a deviation in PID control during the system startup, stable operation, and shutdown (there is a deviation between the actual outlet temperature of the stack 12 and the required outlet temperature of the stack 12), the air volume is adjusted to control the temperature deviation and protect the stack 12. The temperature of the battery system is precisely controlled by flow regulation to ensure that each part (stack 12, circulating pump 17, etc.) works at an ideal temperature, thereby improving the efficiency and life of the fuel cell.

[0040] 1. The specific control method of the stack air inlet temperature is as follows:

[0041] 1) Determine the relationship between the stack inlet temperature T1 and the safety threshold T1max, and calculate the temperature difference △T1=T1-T1max;

[0042] 2) If △T1≤0, the stack inlet temperature is within the safe range and no regulation is required. The first fan does not need to be enabled, and the bypass air before the second mixer is 0;

[0043] 3) If △T1>0, the inlet temperature of the fuel cell stack exceeds the safety threshold and needs to be regulated. The over-temperature protection regulation method is as follows: When the inlet of the fuel cell stack is over-temperature, the first fan is enabled, and the upper bypass cold air enters the second mixer to reduce the inlet temperature of the fuel cell stack until it is regulated within the safety threshold.

[0044] This control method ensures that the inlet temperature of the battery stack is always maintained within a safe operating range by adjusting the flow rate of the bypass air path, avoiding damage to the battery system caused by overheating. The flow adjustment of the bypass air path can flexibly respond to changes in temperature differences, ensuring fast and stable operation of the system.

[0045] 2. The specific control method of the inlet temperature before the circulation pump is similar to the above, as follows:

[0046] 1) Determine the relationship between the circulating pump inlet temperature T2 and the safety threshold T2max, and calculate the temperature difference △T2=T2-T2max;

[0047] 2) If △T2≤0, the circulating pump inlet temperature is within the safe range and no regulation is required. The third fan does not need to be enabled, and the air flow rate of the bypass air path before the first mixer is 0;

[0048] 3) If △T2>0, the circulating pump inlet temperature exceeds the safety threshold and needs to be regulated. The over-temperature protection regulation method is as follows: When the circulating pump inlet is over-temperature, the third fan is enabled, and the cold air from the lower air-cooling air path enters the air cooler. The cold air reduces the hot side fuel temperature, thereby reducing the circulating pump inlet temperature until it is regulated within the safety threshold.

[0049] 3. The outlet temperature of the stack is regulated by PID. When there is a deviation in PID regulation during the system startup, stable operation, and shutdown (there is a deviation between the actual outlet temperature of the stack and the required outlet temperature of the stack), the air volume needs to be adjusted to ensure the operating performance of the stack and avoid stack attenuation. The specific regulation methods are as follows:

[0050] 1) When the stack outlet temperature is greater than the stack required temperature:

[0051] ① If the stack outlet temperature is lower than the stack inlet temperature, it is necessary to reduce the duty cycle of the second fan, reduce the main air flow, and then reduce the stack outlet temperature, so that the stack outlet temperature is consistent with the stack outlet required temperature.

[0052] ② If the stack outlet temperature is greater than the stack inlet temperature, it is necessary to increase the duty cycle of the second fan and increase the main air flow, thereby reducing the stack outlet temperature so that the stack outlet temperature is consistent with the stack outlet required temperature.

[0053] ③ If the stack outlet temperature is equal to the stack inlet actual temperature, then by lowering the stack inlet required temperature, increasing the duty cycle of the first fan, increasing the air volume of the bypass ventilation duct into the stack, and thus lowering the stack inlet actual temperature, the stack outlet actual temperature is lowered to match the demand;

[0054] 2) When the stack outlet temperature is lower than the stack required temperature:

[0055] ① If the stack outlet temperature is lower than the stack inlet temperature, it is necessary to increase the duty cycle of the second fan and increase the main air flow rate so that more air can flow into the system to increase the stack temperature, thereby increasing the stack outlet temperature and making the stack outlet temperature consistent with the stack outlet required temperature;

[0056] ② If the stack outlet temperature is higher than the stack inlet temperature, it is necessary to reduce the duty cycle of the second fan and the main air flow rate so that less low-temperature air can enter the system to increase the temperature of the stack, thereby increasing the stack outlet temperature and making the stack outlet temperature consistent with the required stack outlet temperature.

[0057] ③ If the stack outlet temperature is equal to the stack inlet actual temperature, then by increasing the stack inlet demand temperature, reducing the duty cycle of the first fan, reducing the air volume of the bypass ventilation duct into the stack, and thereby increasing the stack actual inlet temperature, the stack actual outlet temperature is matched with demand.

[0058] Among them, the fan flow of the three routes is all feedback controlled. The control quantity is the pulse width modulation (PWM) signal, and the feedback quantity is the reading of the air flow meter of the corresponding wind route. By adjusting the duty cycle of PWM, the reading of the air flow meter of each route is made consistent with the corresponding required air volume.

[0059] The main functions of the fan are to pump the required air flow, fault alarm and fault measures. According to the fan performance setting corresponding calibration limit, when the threshold is exceeded, the controller needs to report the corresponding fault and take corresponding measures to avoid damage to the system and components.

[0060] 1) When the fan pressure ratio is greater than its maximum allowable value, the system will report a fan pressure ratio maximum fault and trigger the system to shut down;

[0061] 2) When the absolute error between the actual speed of the fan and the speed demand value exceeds the allowable deviation for a certain period of time, the air supply system control module triggers the system to shut down.

[0062] This safety mechanism can effectively prevent fan overload and abnormal operation, protect the stability and safety of the system, and avoid larger problems caused by fan failure.

[0063] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A fuel cell system temperature control method, characterized in that: The battery system includes a main air path, an air-cooling air path and a bypass air path. The air-cooling air path is merged into the main air path after heat exchange in front of the circulation pump to form a mixed air path. The bypass air path is mixed with the mixed air path and then enters the battery stack. The temperature control method includes: when the inlet temperature of the battery stack does not meet the requirements, adjusting the flow of the bypass air path; when the outlet temperature of the battery stack does not meet the requirements, adjusting the flow of the main air path; when the inlet temperature of the circulating pump does not meet the requirements, adjusting the flow of the air-cooling air path.

2. The fuel cell system temperature control method according to claim 1, characterized in that: The stack inlet temperature control includes: Obtain the stack inlet temperature T1, determine the relationship between T1 and the safety threshold T1max of the stack inlet temperature, and calculate the temperature difference ΔT1=T1-T1max; When ΔT1≤0, the current operating state is maintained and the stack inlet temperature is kept within a safe range; When ΔT1>0, the bypass air flow rate is increased until the stack inlet temperature T1 drops below T1max.

3. The fuel cell system temperature control method according to claim 2, characterized in that: Circulation pump inlet temperature control includes: The stack outlet temperature Tout is obtained. When Tout deviates from the preset required temperature Toutx, the main air flow is adjusted according to the relationship between the stack outlet temperature Tout and the stack inlet temperature T1.

4. The fuel cell system temperature control method according to claim 3, characterized in that: When the stack outlet temperature Tout>the preset required temperature Toutx, if the stack outlet temperature Tout<the stack inlet temperature T1, the main air flow rate is reduced; if the stack outlet temperature Tout>the stack inlet temperature T1, the main air flow rate is increased; if the stack outlet temperature Tout=the stack inlet temperature T1, the bypass air flow rate is increased.

5. The fuel cell system temperature control method according to claim 3, characterized in that: When the stack outlet temperature Tout<the preset required temperature Toutx, if the stack outlet temperature Tout<the stack inlet temperature T1, the main air flow rate is increased; if the stack outlet temperature Tout>the stack inlet temperature T1, the main air flow rate is reduced; if the stack outlet temperature Tout=the stack inlet temperature T1, the bypass air flow rate is reduced.

6. The fuel cell system temperature control method according to claim 1, characterized in that: Circulation pump inlet temperature control includes: Obtain the circulating pump inlet temperature T2, determine the relationship between T2 and the safety threshold value T2max of the circulating pump inlet temperature, and calculate the temperature difference ΔT2=T2-T2max; When ΔT2≤0, maintain the current operating state and keep the circulating pump inlet temperature within a safe range; When ΔT2>0, the air cooling air flow rate is increased, and the cold air flow rate entering the mixer is adjusted until the circulating pump inlet temperature T2 drops below T2max.

7. The fuel cell system temperature control method according to claim 1, characterized in that: A first temperature sensor is arranged on the pipeline in front of the fuel cell stack, a third temperature sensor is arranged on the pipeline behind the fuel cell stack, and a second temperature sensor is arranged on the pipeline in front of the circulation pump. The first temperature sensor is used to obtain the inlet temperature of the fuel cell stack, the third temperature sensor is used to obtain the outlet temperature of the fuel cell stack, and the second temperature sensor is used to obtain the inlet temperature of the circulation pump.

8. The fuel cell system temperature control method according to claim 1, characterized in that: The bypass air passage is provided with a first fan and a first flowmeter, the main air passage is provided with a second fan and a second flowmeter, and the air-cooling air passage is provided with a third fan and a third flowmeter. The flow of the main air passage is provided by the second fan and detected by the second flowmeter, the flow of the bypass air passage is provided by the first fan and detected by the first flowmeter, and the flow of the air-cooling air passage is provided by the third fan and detected by the third flowmeter.

9. The fuel cell system temperature control method according to claim 8, characterized in that: The fan flows of the three routes are all feedback controlled. The control quantity is the pulse width modulation signal, and the feedback quantity is the reading of the air flow meter of the corresponding route. By adjusting the duty cycle of the pulse width modulation, the reading of the air flow meter of each route is made consistent with the corresponding required air volume.

10. The fuel cell system temperature control method according to claim 9, characterized in that: When the fan pressure ratio is greater than the first predetermined value, the system reports a maximum fan pressure ratio fault, triggering the system to shut down; When the absolute error between the actual speed of the fan and the speed demand value exceeds the allowable deviation, the system is triggered to shut down.

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