Fuel cell system low-temperature purging method, device, system and carrier

Abstract

The invention discloses a low-temperature purging method, device and system for a fuel cell system and a carrier, and the purging method comprises the following steps: judging whether a current state meets a low-temperature purging requirement or not according to a judgment condition, and if yes, entering a low-temperature purging process: judging whether the fuel cell system runs normally in a low-temperature environment or not before shutdown; when the system is continuously operated for T, the system operates under the condition of 0.15-0.18 standard current density, dry hydrogen and air are respectively introduced into an anode and a cathode of the battery during the operation, the gas flow corresponds to the gas flow under the I standard current density, the temperature of a stack cooling liquid outlet is controlled to be maintained at 60-65 DEG C, and the purging time is t. And different purging strategies are adopted according to different operation conditions. Through the low-temperature purging method, the fuel cell cannot be damaged, and the electric pile can be protected during abnormal shutdown.

Description

Technical Field

[0001] The present invention belongs to the field of fuel cell technology, and specifically relates to a low-temperature purge method, device, system and carrier for a fuel cell system, especially a low-temperature purge method, purge device, purge system, battery system and carrier for a proton exchange membrane fuel cell system. Background Art

[0002] Proton exchange membrane fuel cells are highly efficient and environmentally friendly energy conversion devices with advantages such as high energy conversion efficiency, zero emissions, rapid startup and response, and have broad application prospects in transportation and distributed power generation. However, in low-temperature environments, fuel cell systems may face some problems, such as water condensation reducing the gas diffusion rate, reduced catalyst activity, and possible failure to start normally. Low-temperature purge can remove excess water in the stack, especially liquid water in the cathode and anode channels, reducing the possibility of liquid water freezing and clogging the gas diffusion layer and catalyst layer, allowing the reaction gases (hydrogen and oxygen) to reach the reaction sites more smoothly, thereby accelerating the cold start speed of the stack.

[0003] Different fuel cell systems may experience different operating conditions and problems in low-temperature environments. Existing purge methods are often inadequate and cannot be adjusted to specific conditions. This can lead to suboptimal purge results, and prolonged deep purges may even damage the system stack.

[0004] Therefore, in order to solve the above technical problems, it is necessary to provide a low-temperature purge method, device, system and carrier for a fuel cell system.

[0005] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0006] The object of the present invention is to provide a method, device, system and carrier for low-temperature purge of a fuel cell system.

[0007] In order to achieve the above object, a specific embodiment of the present invention provides the following technical solutions:

[0008] A low-temperature purge method for a proton exchange membrane fuel cell system comprises the following steps:

[0009] Based on the judgment conditions, determine whether the current state meets the low-temperature purge requirements. If so, enter the low-temperature purge process. The judgment condition is whether the stack coolant outlet temperature is less than 60-70°C at a standard current density of 1 when the system is shut down:

[0010] Determine whether the fuel cell system operates normally in a low-temperature environment (the stack coolant outlet temperature is less than 60-70°C during operation) before shutdown:

[0011] If so, when the continuous operation time is T, the system operates under the conditions of 0.15-0.18 standard current density. During this period, dry hydrogen and air are respectively introduced into the anode and cathode of the battery. The gas flow rate corresponds to the gas flow rate at the standard current density of I. The outlet temperature of the fuel cell coolant is controlled to be maintained at 60-65°C, and the purge time is t. When T>30min, I is set to I1 and t is t1; when T≤30min, I is set to I2 and t is t2, satisfying I1≥I2; t1≥t2.

[0012] In one or more embodiments of the present invention, if the fuel cell system operates normally in a low-temperature environment and the operating time is greater than 30 minutes, the following steps are adopted for purging: the fuel cell is set to operate under the conditions of a standard current density of 0.15-0.18, during which dry hydrogen and air are respectively introduced into the anode and cathode of the battery, and the gas flow rate of the anode and cathode corresponds to the gas flow rate at a standard current density of 1.2-1.4. The stack coolant outlet temperature is controlled to be maintained at 60-65°C, and the purge time is set to 4-6 minutes.

[0013] In one or more embodiments of the present invention, if the fuel cell system operates normally in a low-temperature environment and the operating time is less than or equal to 30 minutes, the following steps are adopted for purging: the fuel cell is set to operate under the conditions of a standard current density of 0.15-0.18, during which dry hydrogen and air are respectively introduced into the anode and cathode of the battery, and the gas flow rate of the anode and cathode corresponds to the gas flow rate at a standard current density of 1.0-1.2. The stack coolant outlet temperature is controlled to be maintained at 60-65°C, and the purge time is set to 2-4 minutes.

[0014] In one or more embodiments of the present invention, it is determined whether the fuel cell system operates normally before shutdown:

[0015] If not, that is, the first fault occurs during operation and the fault handling time is less than or equal to 10 minutes, then the following steps are used for purging: restart the fuel cell stack and load it to the idle operating point, run at the idle operating point for 5-10 minutes, reduce the load to 0.15-0.18 standard current density, use dry hydrogen and air to introduce into the anode and cathode of the battery respectively, the gas flow rate of the anode and cathode corresponds to the gas flow rate at the standard current density of 1.0-1.2, control the fuel cell stack coolant outlet temperature to maintain at 50-60 ° C, and set the purging time to 2-4 minutes.

[0016] In one or more embodiments of the present invention, it is determined whether the fuel cell system operates normally before shutdown:

[0017] If not, that is, a second fault occurs during operation and the fault handling time is greater than 10 minutes, then the following steps are used for purging: Use nitrogen to purge the anode and cathode of the battery stack.

[0018] In one or more embodiments of the present invention, the first fault is selected from: signal offline (component signal loss, etc.), raw gas supply flow failure (such as the hydrogen circulation pump speed is not within the normal range, gas (hydrogen or oxygen, the same below) supply is insufficient or gas is unstable, etc.), coolant supply failure (insufficient coolant supply causes the stack temperature to exceed the normal range, etc.).

[0019] In one or more embodiments of the present invention, the second fault is at least selected from: structural fault (such as pipe rupture, loose clamp, poor seal, etc.), fuel cell failure (such as abnormal cell voltage and current, such as too low voltage, too high current, etc.), gas quality alarm (such as hydrogen concentration alarm, etc.).

[0020] In one or more embodiments of the present invention, the nitrogen purge is performed using high-purity nitrogen or waste nitrogen at a pressure of 50-100 kPa for 5-10 minutes. High-purity nitrogen is nitrogen with a purity of ≥99.9%. Waste nitrogen is waste nitrogen collected by the cathode nitrogen exhaust valve during normal operation of the fuel cell system.

[0021] In one or more embodiments of the present invention, the purge device implements a low-temperature purge method for a proton exchange membrane fuel cell system.

[0022] In one or more embodiments of the present invention, a purge system includes a carrying body and a plurality of purge devices configured on the carrying body.

[0023] In one or more embodiments of the present invention, a battery system includes a plurality of battery stacks and a purge system for purging the battery stacks before shutdown according to instructions.

[0024] In one or more embodiments of the present invention, a vehicle includes a power system, and the power system includes a battery system.

[0025] Compared with the prior art, the fuel cell system low-temperature purge method, device, system and carrier of the present invention have the following advantages:

[0026] 1. The low-temperature purge method of the present invention can adopt different purge strategies according to the different operating states of the fuel cell system in a low-temperature environment, effectively remove moisture from the fuel cell system, and improve the performance and reliability of the fuel cell system in a low-temperature environment.

[0027] 2. By controlling parameters such as the stack coolant outlet temperature, the operating current density of the fuel cell, and the gas flow rate, the purge process can be precisely controlled and the purge effect can be improved.

[0028] 3. Different operating times and fault handling times are distinguished, making the purge method more flexible and practical, and able to adapt to different actual application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 FIG. 1 is a flow chart of a low-temperature purge method for a fuel cell system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0032] The low-temperature purge method for a fuel cell system of the present invention may include the following steps:

[0033] The outlet temperature of the stack coolant determines whether the low-temperature purge conditions are met. If the low-temperature purge conditions are not met, the normal-temperature purge process is entered. If the low-temperature purge conditions are met, the stack low-temperature purge process is entered. The low-temperature purge process is as follows:

[0034] Determine whether the fuel cell system operates normally in a low-temperature environment. If the fuel cell system operates normally in a low-temperature environment and the operating time is greater than 30 minutes, perform a purge using the following steps: The fuel cell is set to operate under a standard current density of 0.15-0.18. During this period, dry hydrogen and air are introduced into the anode and cathode of the battery, respectively. The gas flow rates at the anode and cathode correspond to the gas flow rates at a standard current density of 1.2-1.4. The stack coolant outlet temperature is controlled to be maintained at 60-65°C, and the purge time is set to 4-6 minutes.

[0035] If the fuel cell system operates normally in a low-temperature environment and the operating time is less than or equal to 30 minutes, the following steps are used for purge: the fuel cell is set to operate under the condition of a standard current density of 0.15-0.18, during which dry hydrogen and air are introduced into the anode and cathode of the battery respectively. The gas flow rate of the anode and cathode corresponds to the gas flow rate at a standard current density of 1.0-1.2. The temperature of the stack coolant outlet is controlled to be maintained at 60-65°C, and the purge time is set to 2-4 minutes;

[0036] If the fuel cell system fails when operating in a low-temperature environment and the fault handling time is less than or equal to 10 minutes, the following steps are used for purge: restart the stack and load it to the idle operating point, operate at the idle operating point for 5-10 minutes, reduce the load to 0.15-0.18 standard current density, use dry hydrogen and air to pass through the anode and cathode of the battery respectively, the gas flow rate of the anode and cathode corresponds to the gas flow rate at the standard current density of 1.0-1.2, control the stack coolant outlet temperature to maintain at 50-60 ° C, and set the purge time to 2-4 minutes;

[0037] If a fuel cell system malfunctions while operating in a low-temperature environment and the fault resolution time is greater than 10 minutes, the following steps are used for purging: Use the nitrogen in the nitrogen tank to purge the anode and cathode of the fuel cell stack.

[0038] As an optimal solution, the low-temperature purge condition is: when shutting down, determine whether the outlet temperature of the stack coolant at a standard current density is greater than or equal to 60-70°C. If so, enter the normal temperature purge process; otherwise, enter the low-temperature purge process.

[0039] As a preferred option, situations in which the fuel cell system operates in a low-temperature environment and the processing time for faults is less than or equal to 10 minutes include: loss of component signals, hydrogen circulation pump speed not within the normal range, stack temperature outside the normal range, insufficient or unstable hydrogen or oxygen supply, etc.

[0040] As a preferred solution, situations where the fuel cell system operates in a low-temperature environment and the troubleshooting time is greater than 10 minutes include pipe rupture, loose clamps, poor sealing, low cell voltage, insulation problems, and safety issues caused by hydrogen concentration alarms.

[0041] As a preferred solution, the conditions for nitrogen purging are: nitrogen purity ≥ 99.9%, pressure 50-100 kPa, and purging time 5-10 minutes.

[0042] As a preferred solution, the nitrogen gas can be waste nitrogen gas collected by controlling the cathode nitrogen exhaust valve during normal operation of the fuel cell system, or it can be high-purity nitrogen gas artificially filled from the outside.

[0043] Group 1 embodiment

[0044] Example 11

[0045] In the low-temperature purge method of the proton exchange membrane fuel cell system of this embodiment: the fuel cell system operates normally in a low-temperature environment, and the operating time is greater than 30 minutes. Perform the purge in the following steps: set the fuel cell to operate under the condition of 0.16 standard current density. Dry hydrogen and air are respectively introduced into the anode and cathode of the battery, and the gas flow rate of the anode and cathode corresponds to the gas flow rate at the standard current density of 1.3. The outlet temperature of the stack coolant is controlled to be maintained at 62°C. The purge time is set to 5 minutes. After the stack is purged, the internal resistance of the stack is 3.8 times the wet internal resistance after standing for 10 minutes, confirming that the stack purge is successful. The stack is not damaged after being frozen at -40°C and can be successfully cold-started.

[0046] Example 12

[0047] In the low-temperature purge method of the proton exchange membrane fuel cell system of this embodiment: the fuel cell system operates normally in a low-temperature environment, and the operating time is greater than 30 minutes. Purging is carried out in accordance with the following steps: the fuel cell is set to operate under the condition of 0.16 standard current density. Dry hydrogen and air are respectively introduced into the anode and cathode of the battery, and the gas flow rate of the anode and cathode corresponds to the gas flow rate at the standard current density of 1.2. The outlet temperature of the stack coolant is controlled to be maintained at 60°C. The purge time is set to 4 minutes. After the stack is purged, the internal resistance value of the stack is 3.5 times the wet internal resistance after standing for 10 minutes, confirming that the stack purge is successful, and the stack is not damaged after being frozen at -40°C and can be successfully cold-started.

[0048] Example 13

[0049] In the low-temperature purge method of the proton exchange membrane fuel cell system of this embodiment: the fuel cell system operates normally in a low-temperature environment, and the operating time is greater than 30 minutes. Purging is carried out in accordance with the following steps: the fuel cell is set to operate under the condition of a standard current density of 0.18. Dry hydrogen and air are respectively introduced into the anode and cathode of the battery, and the gas flow rates of the anode and cathode correspond to the gas flow rates at a standard current density of 1.4. The outlet temperature of the stack coolant is controlled to be maintained at 65°C. The purge time is set to 6 minutes. After the stack is purged, the internal resistance of the stack is 4 times the wet internal resistance after standing for 10 minutes, confirming that the stack purge is successful, and the stack is not damaged after being frozen at -40°C and can be successfully cold-started.

[0050] Group 2 embodiment

[0051] Example 21

[0052] In the low-temperature purge method of the proton exchange membrane fuel cell system of this embodiment: the fuel cell system operates normally in a low-temperature environment, and the operating time is less than or equal to 30 minutes. Perform the purge in the following steps: set the fuel cell to operate under the condition of 0.17 standard current density. Dry hydrogen and air are introduced into the anode and cathode of the battery respectively, and the gas flow rate of the anode and cathode corresponds to the gas flow rate at 1.1 standard current density. The outlet temperature of the stack coolant is controlled to be maintained at 63°C. The purge time is set to 3 minutes. After the stack is purged, the internal resistance of the stack is 3.4 times the wet internal resistance after standing for 10 minutes, confirming that the stack purge is successful. The stack is not damaged after being frozen at -40°C and can be successfully cold-started.

[0053] Example 22

[0054] In the low-temperature purge method of the proton exchange membrane fuel cell system of this embodiment: the fuel cell system operates normally in a low-temperature environment, and the operating time is less than or equal to 30 minutes. Purging is carried out in accordance with the following steps: the fuel cell is set to operate under the condition of 0.15 standard current density. Dry hydrogen and air are respectively introduced into the anode and cathode of the battery, and the gas flow rate of the anode and cathode corresponds to the gas flow rate at 1.0 standard current density. The outlet temperature of the stack coolant is controlled to be maintained at 60°C. The purge time is set to 2 minutes. After the stack is purged, the internal resistance value of the stack is 3.2 times the wet internal resistance after standing for 10 minutes, confirming that the stack purge is successful, and the stack is not damaged after being frozen at -40°C and can be successfully cold-started.

[0055] Example 23

[0056] In the low-temperature purge method of the proton exchange membrane fuel cell system of this embodiment: the fuel cell system operates normally in a low-temperature environment, and the operating time is less than or equal to 30 minutes. Purging is carried out in accordance with the following steps: the fuel cell is set to operate under the condition of 0.18 standard current density. Dry hydrogen and air are respectively introduced into the anode and cathode of the battery, and the gas flow rate of the anode and cathode corresponds to the gas flow rate at 1.2 standard current density. The outlet temperature of the stack coolant is controlled to be maintained at 65°C. The purge time is set to 4 minutes. After the stack is purged, the internal resistance value of the stack is 3.8 times the wet internal resistance after standing for 10 minutes, confirming that the stack purge is successful, and the stack is not damaged after being frozen at -40°C and can be successfully cold-started.

[0057] Group 3 embodiment

[0058] Example 31

[0059] In the low-temperature purge method for the proton exchange membrane fuel cell system of this embodiment: the fuel cell system generates a high-temperature alarm when operating in a low-temperature environment, and is diagnosed as the cooling water circulation pump being offline. The system returns to normal after the circulation pump is restarted. In this case, the fault handling time is less than or equal to 10 minutes. The purge is performed in accordance with the following steps: Restart the stack and load it to the idle operating point, and operate it at the idle operating point for 8 minutes. Reduce the load to 0.16 standard current density for operation. Dry hydrogen and air are introduced into the anode and cathode of the battery respectively, and the gas flow rates at the anode and cathode correspond to the gas flow rate at a standard current density of 1.1. The stack coolant outlet temperature is controlled to be maintained at 55°C. The purge time is set to 3 minutes. After the stack is purged, the internal resistance of the stack is 3.3 times the wet internal resistance after standing for 10 minutes, confirming that the stack purge is successful. The stack is not damaged after being frozen at -40°C and can be successfully cold-started.

[0060] Example 32

[0061] In the low-temperature purge method for a proton exchange membrane fuel cell system of this embodiment: a fuel cell system experiences a raw gas supply failure in a low-temperature environment, the system displays that the hydrogen circulation pump is offline, and returns to normal after the circulation pump is restarted. In this case, the fault handling time is less than or equal to 10 minutes. The purge is performed according to the following steps: Restart the stack and load it to the idle operating point, and operate at the idle operating point for 10 minutes. Reduce the load to 0.18 standard current density for operation. Dry hydrogen and air are introduced into the anode and cathode of the battery respectively, and the gas flow rates at the anode and cathode correspond to the gas flow rate at a standard current density of 1.2. The stack coolant outlet temperature is controlled to be maintained at 50°C. The purge time is set to 4 minutes. After the stack is purged, the internal resistance of the stack is 3.4 times the wet internal resistance after standing for 10 minutes, confirming that the stack purge is successful. The stack is not damaged after being frozen at -40°C and can be successfully cold-started.

[0062] Example 33

[0063] In the low-temperature purge method of the proton exchange membrane fuel cell system of this embodiment: the ammeter of the fuel cell system is offline when operating in a low-temperature environment, and it returns to normal after emergency repair and restart. At this time, the fault processing time is less than or equal to 10 minutes. Follow the steps below to purge: Restart the stack and pull the load to the idle operating point, and run at the idle operating point for 5 minutes. Reduce the load to 0.15 standard current density for operation. Dry hydrogen and air are introduced into the anode and cathode of the battery respectively, and the gas flow rate of the anode and cathode corresponds to the gas flow rate at 1.0 standard current density. The outlet temperature of the stack coolant is controlled to be maintained at 50°C. The purge time is set to 2 minutes. After the stack is purged, the internal resistance of the stack is 3.2 times the wet internal resistance after standing for 10 minutes, confirming that the stack purge is successful, and the stack is not damaged after being frozen at -40°C and can be successfully cold-started.

[0064] Group 4 embodiment

[0065] Example 41

[0066] In the low-temperature purge method for the proton exchange membrane fuel cell system of this embodiment: the fuel cell system malfunctions while operating in a low-temperature environment, which is diagnosed as a low hydrogen gas purity alarm. After maintenance operations such as adjusting the gas source and cleaning the circuit, the system is purged, and the fault handling time is significantly greater than 10 minutes.

[0067] The stack's cathode and anode were purged using high-purity nitrogen from a nitrogen tank. The nitrogen pressure was 80 kPa, and the purge time was 8 minutes. After the stack was purged and allowed to rest for 10 minutes, the internal resistance was 3.2 times the wet state internal resistance, confirming successful stack purging. The stack survived a -40°C freeze and was successfully cold-started.

[0068] Example 42

[0069] In the low-temperature purge method for the proton exchange membrane fuel cell system of this embodiment: the fuel cell system malfunctions while operating in a low-temperature environment, which is diagnosed as a rupture in the hydrogen supply pipeline. After maintenance operations such as adjusting the gas source, welding the pipeline, and restoring the pipeline, the system is purged, and the fault resolution time is significantly greater than 10 minutes.

[0070] The stack cathode and anode were purged using high-purity nitrogen from a nitrogen tank. The nitrogen pressure was 50 kPa and the purge time was 5 minutes. After the stack was purged and allowed to rest for 10 minutes, the internal resistance of the stack was three times the wet state internal resistance, confirming that the stack purge was successful. The stack survived a -40°C freeze and could be successfully cold-started.

[0071] Example 43

[0072] In the low-temperature purge method for the proton exchange membrane fuel cell system of this embodiment: the fuel cell system fails while operating in a low-temperature environment, which is diagnosed as a first-stage single cell stack current alarm. After idle inspection, stack adjustment and other maintenance operations, the system is purged, and the fault handling time is significantly greater than 10 minutes.

[0073] The stack cathode and anode were purged using high-purity nitrogen from a nitrogen tank. The nitrogen pressure was 100 kPa and the purge time was 10 minutes. After the stack was purged and allowed to rest for 10 minutes, the internal resistance was 3.5 times the wet state internal resistance, confirming successful stack purging. The stack survived a -40°C freeze and was successfully cold-started.

[0074] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0075] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A low-temperature purge method for a proton exchange membrane fuel cell system, comprising the following steps: Based on the judgment conditions, determine whether the current state meets the low-temperature purge requirements. If so, enter the low-temperature purge process. The judgment condition is whether the stack coolant outlet temperature at 1 standard current density is less than 60-70°C during shutdown: Determine whether the fuel cell system operates normally in a low-temperature environment before shutdown: If so, when the continuous operation time T, the system operates under the condition of 0.15-0.18 standard current density, during which dry hydrogen and air are respectively introduced into the anode and cathode of the battery. The gas flow rate corresponds to the gas flow rate under the standard current density I, and the stack coolant outlet temperature is controlled to be maintained at 60-65 ° C. The purge time is t, where, When T>30min, set I to I1 and t to t1; when T≤30min, set I to I2 and t to t2, satisfying I1≥I2; t1≥t2.

2. The low-temperature purge method for a proton exchange membrane fuel cell system according to claim 1, characterized in that: If the fuel cell system operates normally in a low-temperature environment and the operating time is greater than 30 minutes, the following steps are adopted for purging: the fuel cell is set to operate under the conditions of 0.15-0.18 standard current density, during which dry hydrogen and air are respectively introduced into the anode and cathode of the battery, and the gas flow rate of the anode and cathode corresponds to the gas flow rate at the standard current density of 1.2-1.

4. The stack coolant outlet temperature is controlled to be maintained at 60-65°C, and the purge time is set to 4-6 minutes.

3. The low-temperature purge method for a proton exchange membrane fuel cell system according to claim 1, characterized in that: If the fuel cell system operates normally in a low-temperature environment and the operating time is less than or equal to 30 minutes, the following steps are used for purging: the fuel cell is set to operate under the conditions of a standard current density of 0.15-0.18, during which dry hydrogen and air are respectively introduced into the anode and cathode of the battery, and the gas flow rate of the anode and cathode corresponds to the gas flow rate at the standard current density of 1.0-1.

2. The stack coolant outlet temperature is controlled to be maintained at 60-65°C, and the purge time is set to 2-4 minutes.

4. The low-temperature purge method for a proton exchange membrane fuel cell system according to claim 1, characterized in that: Determine whether the fuel cell system is operating normally before shutdown: If not, that is, the first fault occurs during operation and the fault handling time is less than or equal to 10 minutes, then the following steps are used for purging: restart the fuel cell stack and load it to the idle operating point, run at the idle operating point for 5-10 minutes, reduce the load to 0.15-0.18 standard current density, use dry hydrogen and air to introduce into the anode and cathode of the battery respectively, the gas flow rate of the anode and cathode corresponds to the gas flow rate at the standard current density of 1.0-1.2, control the fuel cell stack coolant outlet temperature to maintain at 50-60 ° C, and set the purging time to 2-4 minutes.

5. The low-temperature purge method for a proton exchange membrane fuel cell system according to claim 1, characterized in that: Determine whether the fuel cell system is operating normally before shutdown: If not, that is, a second fault occurs during operation and the fault handling time is greater than 10 minutes, then the following steps are used for purging: Use nitrogen to purge the anode and cathode of the battery stack.

6. The low-temperature purge method for a proton exchange membrane fuel cell system according to claim 4, characterized in that: The first fault is selected from: signal offline, raw gas supply flow failure, and coolant supply failure.

7. The low-temperature purge method for a proton exchange membrane fuel cell system according to claim 5, characterized in that: The second fault is at least selected from: a structural fault, a cell fault of a fuel cell stack, and a gas quality alarm.

8. The low-temperature purge method for a proton exchange membrane fuel cell system according to claim 5, characterized in that: The nitrogen purge conditions are: high-purity nitrogen or waste nitrogen, a pressure of 50-100 kPa, and a purge time of 5-10 minutes.

9. A purge device for implementing the low-temperature purge method for a proton exchange membrane fuel cell system according to any one of claims 1 to 8.

10. A purge system comprising a carrying body and a plurality of purge devices according to claim 9 arranged on the carrying body.

11. A battery system comprising a plurality of battery stacks and a purge system according to claim 10 for purging the battery stacks before shutdown according to instructions.

12. A vehicle comprising a power system comprising the battery system according to claim 11.

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