Shut-down control method, fuel cell system, and vehicle

Abstract

The application discloses a shutdown control method, a fuel cell system and a vehicle, wherein the shutdown control method is used for the fuel cell system, the fuel cell system comprises a stack cavity purging inlet pipeline and a stack cavity purging outlet pipeline for purging a stack and a drain pipe, a purging branch is arranged between the stack cavity purging outlet pipeline and the drain pipe, a purging control valve is arranged on the purging branch, and the shutdown control method comprises the following steps: in response to the end of the drain valve drainage, the purging control valve is controlled to be opened so as to purge the drain pipe by the gas in the stack cavity purging outlet pipeline; the purging time of the drain pipe is recorded; and when the purging time of the drain pipe reaches a first preset time, the purging control valve is controlled to be closed. The control method can effectively deal with the residual hydrogen in the drain pipe, prevent the residual hydrogen from diffusing into the stack shell, and thus the safety of the system is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cell, in particular to a shutdown control method, a fuel cell system and a vehicle. BACKGROUND

[0002] In the related art, a fuel cell generates electricity by reacting hydrogen and oxygen, and water generated at the cathode side needs to diffuse across the proton exchange membrane to the anode side (hydrogen side). However, after a long time of operation, the anode side of the fuel cell system can accumulate too much moisture, causing the hydrogen flow channel to be blocked, thereby affecting the supply of hydrogen and reducing the output power and life of the fuel cell. Therefore, the anode side of the fuel cell system needs to be drained regularly. During the drainage process, part of the hydrogen will be discharged with the water and then discharged into the atmosphere through the tail gas.

[0003] However, after the fuel cell system is shut down, hydrogen often remains in the drainage pipeline, and this remaining hydrogen can diffuse into the stack housing through the tail discharge and stack housing purge pipeline. This can cause the problem of an increase in the hydrogen concentration inside the stack housing, and when the fuel cell is started again, the hydrogen concentration sensor inside the stack housing can detect a high concentration of hydrogen and trigger an alarm. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, one object of the present application is to provide a shutdown control method that can effectively handle the residual hydrogen in the drainage pipe and prevent the residual hydrogen from diffusing into the stack housing, thereby improving the safety of the system and ensuring the normal operation of the battery.

[0005] A second object of the present application is to provide a fuel cell system.

[0006] A third object of the present application is to provide a vehicle.

[0007] To achieve the above-mentioned objects, the shutdown control method according to a first aspect of the present application is used in a fuel cell system, the fuel cell system comprising a stack cavity purge inlet pipeline and a stack cavity purge outlet pipeline for purging the stack, and a drainage pipeline, a purge branch is arranged between the stack cavity purge outlet pipeline and the drainage pipeline, and a purge control valve is arranged on the purge branch, the shutdown control method comprising: in response to the end of the stack drainage, controlling the purge control valve to open to purge the drainage pipeline with the gas in the stack cavity purge outlet pipeline; recording the time of purging the drainage pipeline; and when the time of purging the drainage pipeline reaches a first predetermined time, controlling the purge control valve to close.

[0008] According to the shutdown control method of the embodiment of the present application, by arranging a purge branch and a purge control valve between the stack cavity purge exhaust pipeline and the drain pipeline, after the system drainage is completed, the purge control valve is controlled to be opened, and the gas in the stack cavity purge exhaust pipeline is forced to purge the drain pipeline, when the purging time of the drain pipeline reaches the first preset time, the purge control valve is controlled to be closed, this process can effectively deal with the residual hydrogen in the drain pipeline, prevent the residual hydrogen from diffusing into the stack shell, ensure that the system will not appear hydrogen accumulation in the shutdown state, thereby improving the safety of the fuel cell system, and ensuring the normal operation of the battery.

[0009] In some embodiments, the fuel cell system further comprises an air compressor for providing purge gas to the stack cavity purge inlet pipeline, and the shutdown control method further comprises: after the purge control valve is controlled to be closed, the air compressor is controlled to be closed for a second preset time.

[0010] In some embodiments, the shutdown control method further comprises: in response to the shutdown instruction, the anode inlet valve of the fuel cell system is controlled to be closed, and the air compressor is controlled to continue to operate to continue to purge the stack of the fuel cell through the stack cavity purge inlet pipeline.

[0011] In some embodiments, the shutdown control method further comprises: controlling the drain valve of the fuel cell to be opened to drain through the drain pipeline; recording the time of draining through the drain pipeline; when the time of draining through the drain pipeline reaches a third preset time, it is determined that the drain valve has completed the drainage.

[0012] In order to achieve the above purpose, the fuel cell system of the second embodiment of the present application comprises: a stack, the stack comprising a shell and a core; a stack cavity purge inlet pipeline connected with the shell, for introducing air into the shell to purge the gap between the shell and the core; a stack cavity purge exhaust pipeline connected with the shell, for exhausting waste gas in the gap; a drain pipeline connected with the shell, for draining waste water generated by the fuel cell; a purge branch arranged between the stack cavity purge exhaust pipeline and the drain pipeline; a purge control valve arranged on the purge branch to control the on-off of the purge branch; and a controller for executing the shutdown control method described in the above embodiments.

[0013] According to the fuel cell system of the embodiment of the present application, after the exhaust water generated by the fuel cell is discharged, the controller executes the shutdown control method described in the above embodiment, the purge control valve is controlled to be opened, the air in the stack cavity purge discharge pipeline flows into the drain pipe through the purge branch, so that the forced purging of the drain pipe is realized, and then the residual hydrogen in the drain pipe can be effectively treated, the residual hydrogen is prevented from diffusing into the inside of the stack shell, and the hydrogen accumulation in the system in the shutdown state is avoided, so that the safety of the fuel cell system is improved, and the normal operation of the battery is ensured.

[0014] In some embodiments, the fuel cell system further comprises a hydrogen storage container, an outlet of the hydrogen storage container being connected to the shell to introduce hydrogen into the shell; and a hydrogen inlet valve arranged on a pipeline between the hydrogen storage container and the shell to control the hydrogen introduced into the shell.

[0015] In some embodiments, the fuel cell system further comprises a gas-liquid separator, an inlet of the gas-liquid separator being connected to the shell, a gas outlet of the gas-liquid separator being connected to the pipeline between the hydrogen storage container and the shell, and a liquid outlet of the gas-liquid separator being connected to the drain pipe; and a drain valve arranged at the liquid outlet of the gas-liquid separator.

[0016] In some embodiments, the fuel cell system further comprises an air compressor, a intercooler, an outlet of the intercooler being connected to an outlet of the air compressor, and an inlet of the intercooler being connected to the stack cavity purge inlet pipeline; a humidifier, a first inlet of the humidifier being connected to an outlet of the intercooler, a first outlet of the humidifier being connected to the shell through an air inlet pipeline to introduce air into the shell, and a second inlet of the humidifier being connected to the shell through a first exhaust pipeline to discharge exhaust gas in the shell; and a total exhaust pipeline, the total exhaust pipeline being connected to a second outlet of the humidifier, the stack cavity purge discharge pipeline, and the drain pipe respectively.

[0017] In some embodiments, the fuel cell system further comprises a bypass pipeline connected between the outlet of the intercooler and the total exhaust pipeline; and a bypass valve arranged on the bypass pipeline.

[0018] In order to achieve the above-mentioned purpose, the vehicle of the third embodiment of the present application comprises the fuel cell system described in the above embodiments.

[0019] According to the vehicle of the embodiment of the present application, by adopting the fuel cell system described in the above embodiment, after the exhaust of the waste water generated by the fuel cell, the purge control valve is controlled to be opened, the stack cavity purge discharge pipeline is filled with air through the purge branch to the drain pipe, so as to realize the forced purge of the drain pipe, and then the residual hydrogen in the drain pipe can be effectively treated, the residual hydrogen is prevented from diffusing into the inside of the stack shell, and the hydrogen accumulation in the system in the shutdown state is avoided, so as to improve the safety of the fuel cell system and ensure the normal operation of the battery.

[0020] Additional aspects and advantages of the present application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and / or can be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0021] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood by considering the following detailed description, from which the above-mentioned and other aspects, advantages, and novel features of the present application will become readily apparent, taken in conjunction with the accompanying drawings.

[0022] Figure 1 is a schematic diagram of a fuel cell system according to an embodiment of the present application;

[0023] Figure 2 is a flow chart of a shutdown control method according to an embodiment of the present application;

[0024] Figure 3 is a flow chart of system shutdown purge according to an embodiment of the present application;

[0025] Figure 4 is a block diagram of a vehicle according to an embodiment of the present application.

[0026] REFERENCE NUMERALS

[0027] vehicle 100;

[0028] fuel cell system 101;

[0029] stack 1; stack cavity purge inlet pipeline 2; stack cavity purge discharge pipeline 3; drain pipe 4; purge branch 5; hydrogen storage container 6; hydrogen inlet valve 7; gas-liquid separator 8;

[0030] air compressor 10; intercooler 20; humidifier 30; total exhaust pipe 40; air inlet pipe 50; bypass pipeline 60; first exhaust pipe 70; hydrogen concentration sensor 11; drain valve 41; purge control valve 51; bypass valve 61. DETAILED DESCRIPTION

[0031] The embodiments of the present application are described in detail below with reference to the accompanying drawings. The embodiments of the present application described below with reference to the accompanying drawings are exemplary.

[0032] In the related art, after the fuel cell system is shut down, hydrogen gas often remains in the drain pipeline, and the remaining hydrogen gas can diffuse into the stack shell through tail exhaust and stack shell purging pipeline, which is a problem. Embodiments of the present application propose a shutdown control method, which can effectively handle the residual hydrogen gas in the drain pipeline and prevent the residual hydrogen gas from diffusing into the stack shell, thereby improving the safety of the system.

[0033] To facilitate the description of the technical solutions, the fuel cell system of the embodiments of the present application will be described first.

[0034] Figure 1 is a schematic diagram of a fuel cell system according to an embodiment of the present application, as Figure 1 shown, the fuel cell system 101 includes: a stack 1, a stack cavity purging inlet pipeline 2, a stack cavity purging exhaust pipeline 3, a drain pipeline 4, a purging branch 5, a purging control valve 51 and a controller.

[0035] The stack 1 can be the core component of the fuel cell system 101, including a shell and a core. The shell can be used to wrap and protect the core, maintain the isolation of the core from the external environment, and ensure the safe operation of the stack 1. In embodiments, the shell of the stack 1 can be made of a variety of different materials, and the specific selection depends on the design, performance requirements and application environment of the fuel cell system 101. Common stack shell materials can include stainless steel, carbon fiber composite materials, polymers and metal coated materials, etc.

[0036] Specifically, stainless steel is a commonly used stack shell material, which is popular due to its corrosion resistance, high strength and relatively low cost. Stainless steel can resist corrosion in humid environments and is relatively easy to process. Carbon fiber composite materials are also commonly used in stack shells, which are usually lighter and have excellent strength and stiffness. These materials are crucial for reducing the overall weight of the stack 1 and improving performance. They can also resist corrosion, but may require additional protection in high temperature environments. Polymer materials such as polypropylene or polyethylene can also be used for stack shells. They are commonly used in low-temperature fuel cell systems due to their relatively low corrosion resistance and mechanical strength, but have lower manufacturing costs. The stack shell can also be made of metal coated materials, which have high temperature resistance and corrosion resistance, and are relatively more commonly used in high temperature fuel cell systems.

[0037] In some embodiments, the stack is a part where hydrogen and oxygen react to generate electricity. The stack can be a PEMFC (Proton Exchange Membrane Fuel Cell) stack. This type of stack can use a proton exchange membrane to separate the anode and cathode, as well as separate the hydrogen and oxygen. The stack is typically composed of many unit cells, each of which can include an anode, a cathode, and a proton exchange membrane. These unit cells are stacked together to form the stack 1. The materials of the stack can typically include a proton exchange membrane, a catalyst layer, and a support layer. The proton exchange membrane is typically made of a fluorinated polymer, which has high electronic and proton conductivity. The catalyst layer typically includes a noble metal catalyst, such as platinum. The support layer is typically made of carbon or carbon nanotubes, which are used to support the catalyst and provide electronic conductivity.

[0038] In some embodiments, the stack cavity purge inlet line 2 can refer to a line or passage in the fuel cell system 101 that is connected to the housing for introducing air into the housing to purge the gap between the housing and the stack, preventing the accumulation of leaked hydrogen from the stack 1 in the housing, which can be dangerous. This helps to maintain a proper gas environment inside the stack 1 to facilitate the electrochemical reaction. The stack cavity purge outlet line 3 is also connected to the housing for removing waste gas from the gap to keep the internal environment of the stack 1 clean and ensure normal operation of the stack 1.

[0039] In some embodiments, the fuel cell generates electricity through the reaction of hydrogen and oxygen, and water produced on the cathode side can diffuse across the proton exchange membrane to the anode side (hydrogen side). Excessive water on the anode side can block the hydrogen flow path, leading to insufficient hydrogen supply and affecting the output power and life of the fuel cell. Therefore, regular water drainage treatment is needed for the anode side, and the drain pipe 4 can be the main passage for water drainage of the fuel cell system 101, which is connected to the housing for removing waste water produced by the fuel cell. The waste water typically contains water and hydrogen.

[0040] In some embodiments, the purge branch 5 can refer to a line or passage connected between the stack cavity purge outlet line and the drain pipe 4. The main function of the purge branch 5 can be to address the problem of residual hydrogen in the drain pipe 4 in the system shutdown state, preventing the diffusion of hydrogen into the stack housing. A purge control valve 51 can be provided on the purge branch 5 to control the opening and closing of the purge branch 5. Specifically, when the system is shut down, after the drain valve 41 is closed, the purge control valve 51 is opened to force the purge air through the stack housing to purge the residual hydrogen in the drain pipe 4, thereby removing the residual hydrogen in the drain pipe 4. In addition, when the fuel cell system is running, the purge control valve 51 needs to be closed to prevent hydrogen in the drain pipe 4 from entering the stack housing through the purge branch 5.

[0041] In some embodiments, the controller can be the intelligent control hub of the entire system. It performs the shutdown control method described in the following embodiments. The controller is responsible for monitoring the state of the system, responding to corresponding signals, coordinating the operation of various components, and ensuring that the residual hydrogen in the drain pipe 4 is effectively treated. In addition, the controller can also record various parameters and execution times for the monitoring and maintenance of the system operation.

[0042] According to the fuel cell system 101 of the embodiments of the present application, after discharging the waste water generated by the fuel cell, the controller performs the shutdown control method described in the following embodiments, and by controlling the purge control valve 51 to open, the stack cavity purge discharge pipeline 3 flows into the air in the drain pipe 4 through the purge branch 5, to realize forced purging of the drain pipe 4, and then the residual hydrogen in the drain pipe 4 can be effectively treated, preventing the residual hydrogen from diffusing into the inside of the stack housing, ensuring that the system will not appear hydrogen accumulation in the shutdown state, thereby improving the safety of the fuel cell system 101 and ensuring the normal operation of the battery.

[0043] In some embodiments, the fuel cell system 101 further comprises a hydrogen storage container 6 and a hydrogen inlet valve 7. Among them, the hydrogen storage container 6 can be a device for storing hydrogen, usually a gas pressure container. In the fuel cell system 101, the gas outlet of the hydrogen storage container 6 is connected with the housing, allowing hydrogen to be introduced into the housing. The role of the hydrogen storage container 6 can be to provide hydrogen supply for the stack 1 to use when running. It can store high-pressure hydrogen to ensure that the stack 1 can obtain sufficient hydrogen when needed, thereby maintaining the normal operation of the system. The hydrogen storage container 6 can be designed according to the needs of the system, usually needs to have enough gas storage capacity to support the operation of the system, and needs to ensure the safe storage and release of hydrogen.

[0044] The hydrogen inlet valve 7 can be a control valve arranged on the pipeline between the hydrogen storage container 6 and the housing. Its main role is to regulate and control the flow of hydrogen from the hydrogen storage container 6 into the stack 1. The hydrogen inlet valve 7 can be opened or closed according to the needs of the system to control the supply of hydrogen. This control is to ensure that the system can obtain sufficient hydrogen when needed to maintain the electrochemical reaction, while stopping the supply of hydrogen when the system is shut down or maintained to ensure the safety of the system.

[0045] As Figure 1As shown, the fuel cell system 101 further comprises a gas-liquid separator 8 and a drain valve 41. The gas-liquid separator 8 can be a device for separating gas and liquid. The inlet of the gas-liquid separator 8 is connected to the housing to receive the mixed gas and liquid, typically a mixture of hydrogen and water vapor, flowing out of the housing. Inside the gas-liquid separator 8, it separates the gas and liquid by physical or gravitational separation principle. The gas outlet of the gas-liquid separator 8 is connected to the pipeline between the hydrogen storage container 6 and the housing to deliver the separated hydrogen to the hydrogen storage container 6 for recovery and storage of hydrogen. The liquid outlet of the gas-liquid separator 8 is connected to the drain pipe 4 to discharge the separated liquid, typically water, out of the system to remove moisture from the housing and ensure the normal operation of the system.

[0046] It should be noted that although the gas-liquid separator 8 can effectively separate the gas and liquid, it may not be able to completely separate the hydrogen and water in actual operation. This means that some hydrogen may remain in the drain pipe 4. The remaining hydrogen may be due to the performance limitations of the gas-liquid separator 8, gas solubility, gas leakage or other factors. These remaining hydrogen may diffuse into the stack housing through the tail exhaust or stack housing purge pipeline. Therefore, by setting the purge branch 5 and the purge control valve 51, the drain pipe 4 can be forcibly purged after the system is shut down to ensure that the remaining hydrogen is effectively removed and prevented from diffusing into the stack housing, thereby improving the safety and performance of the system.

[0047] The drain valve 41 can be a control valve set at the liquid outlet of the gas-liquid separator 8 to control and regulate the flow of waste water. The drain valve 41 can be opened or closed according to the needs of the system to ensure that the moisture in the drain pipe 4 is effectively removed, thereby helping to prevent moisture from accumulating on the anode side and reducing the risk of the hydrogen flow path being blocked by water vapor, thereby maintaining the safety of the system.

[0048] In some embodiments, as Figure 1 As shown, the fuel cell system 101 further comprises an air compressor 10, an intercooler 20, a humidifier 30 and a total exhaust pipe 40.

[0049] The air compressor 10 can be a device for sucking air from the atmosphere and increasing its pressure by compression. This is to ensure that there is enough oxygen supply in the stack 1 to support the electrochemical reaction. By compressing the air, the oxygen concentration can be increased, the oxygen transfer rate can be increased, the gas density can be increased, etc., thereby enabling the fuel cell system 101 to generate electricity more efficiently.

[0050] The intercooler 20 can be a component for cooling the compressed air discharged from the air compressor 10. The input port of the intercooler 20 is connected to the discharge port of the air compressor 10, and the output port of the intercooler 20 is connected to the stack cavity purge intake line 2. The intercooler 20 can reduce the temperature of the air to prevent excessive heat from entering the stack 1. Cooling the air helps to improve the efficiency and stability of the stack 1.

[0051] The humidifier 30 can be used to increase the moisture content in the gas. The first input port of the humidifier 30 is connected to the output port of the intercooler 20, and the first output port of the humidifier 30 is connected to the housing through the intake pipe 50 to introduce air into the housing. The second input port of the humidifier 30 is connected to the housing through the first exhaust pipe 70 to exhaust the exhaust gas in the housing. In an embodiment, the exhaust gas discharged from the first exhaust pipe 70 can be relatively dry exhaust gas or gas containing a certain amount of moisture. These exhaust gases can be returned to the humidifier 30 to recover some moisture and improve system efficiency.

[0052] The total exhaust pipe 40 can be a pipe for discharging a mixture of exhaust gas and water vapor. The total exhaust pipe 40 is connected to the second output port of the humidifier 30, the stack cavity purge discharge line 3, and the drain pipe 4, respectively. The total exhaust pipe 40 discharges the exhaust gas from the system to maintain normal operation and ensure that the exhaust gas does not accumulate in the system, thereby maintaining the safety of the fuel cell system 101.

[0053] In some embodiments, the fuel cell system 101 further comprises a bypass line 60 and a bypass valve 61. The bypass line 60 is connected between the output port of the intercooler 20 and the total exhaust pipe 40. The bypass valve 61 is provided on the bypass line 60, and its main function can be to control the opening and closing of the bypass line 60. By controlling the opening or closing of the bypass valve 61, the path of gas flow can be adjusted. The control of the bypass valve 61 can be used to adjust the operation and performance of the system to meet different working requirements.

[0054] In some embodiments, the fuel cell system 101 further comprises a hydrogen concentration sensor 11. The hydrogen concentration sensor 11 is usually provided in the housing of the stack 1 to monitor the concentration change of hydrogen in the stack cavity. The hydrogen concentration sensor 11 can detect whether the hydrogen concentration exceeds the safe range and trigger an alarm or take other measures as necessary to ensure the safe operation of the system. This helps to monitor and maintain the stability and performance of the battery system in real time and take appropriate measures to prevent the concentration of hydrogen from rising, thereby improving the safety of the system.

[0055] Based on the fuel cell system described in the above embodiments, the following describes a shutdown control method according to an embodiment of the present application with reference to Figure 2 and Figure 3 A shutdown control method according to an embodiment of the present application.

[0056] The shutdown control method of the embodiment of the present application is used for a fuel cell system, which comprises a stack cavity purging inlet pipeline and a stack cavity purging outlet pipeline for purging the stack, and a drain pipe. A purging branch is arranged between the stack cavity purging outlet pipeline and the drain pipe, and a purging control valve is arranged on the purging branch, so that the residual hydrogen in the drain pipe can be effectively treated, and the residual hydrogen is prevented from diffusing into the inside of the stack shell.

[0057] Figure 2 The flow chart of the shutdown control method according to an embodiment of the present application is shown in FIG. 1, which comprises at least steps S1-S3, as follows: Figure 2

[0058] S1, in response to the end of the electrically purging drainage, the purging control valve is controlled to be opened to purge the drain pipe by the gas in the stack cavity purging outlet pipeline.

[0059] In some embodiments, the system can use different methods to detect whether the drain pipe has completed the drainage. For example, the system can install a pressure sensor near the drain pipe or the drain valve to monitor the pressure or flow of the waste water drainage. When this sensor detects that the waste water flow stops or reaches a certain preset threshold, the system can automatically consider that the drainage has been completed. Alternatively, the system can start timing when starting the drainage operation, and the timer can send a signal after a certain preset time, indicating that the drain valve can be closed. This time can be set according to the needs of the system. Alternatively, the drain valve can generate an electronic signal or a state change, which can be detected when the drain valve is turned from the drainage position to the closed position, thereby triggering the purging operation. This is not specifically limited herein.

[0060] Specifically, when the drainage of the drain valve ends, the purging control valve is controlled to be opened to introduce compressed gas from the stack cavity purging outlet pipeline. This gas will be guided into the drain pipe, thereby helping to remove the residual hydrogen. The controller can monitor the pressure of the gas to ensure that enough gas enters the drain pipe through the stack cavity purging outlet pipeline to effectively purge the residual hydrogen.

[0061] S2, the time for purging the drain pipe is recorded.

[0062] ​In some embodiments, the purpose of recording the time of the drain pipe purging is to monitor and manage the purging process of the drain pipe to ensure that the purging is long enough to effectively remove the residual hydrogen, thereby improving the safety of the system. The time recording can be realized by a timer or a real-time clock in the system. Specifically, when the purging operation is started in step S1, a timer can be started, which will continue to count until the required purging time is reached. At this time, the system can record the time used, usually in minutes or hours. The record can be stored in the log file of the system for the operator or monitoring system to check at any time.

[0063] S3, when the time of the drain pipe purging reaches, control the purging control valve to close.

[0064] In some embodiments, the first preset time can be a time threshold value preset according to the system requirements and nature of the first preset time. It represents the minimum time required for the drain pipe purging. The determination of the first preset time may take into account factors such as the length, diameter of the exhaust pipe, hydrogen concentration and design parameters of the system. By testing the system in experiments or simulations, an appropriate first preset time can be determined to ensure that the drain pipe is fully purged. The first preset time can be dynamically adjusted according to the system requirements to adapt to different working conditions of the system. For example, if the system monitors that there is more residual hydrogen in the drain pipe, the first preset time can be set longer to ensure the full cleaning of the drain pipe. Conversely, if the drain pipe is usually clean, the purging time can be shortened to improve system efficiency. Therefore, when the purging time reaches the first preset time, the controller controls the purging control valve to close, terminating the purging operation of the drain pipe.

[0065] According to the shutdown control method of the embodiment of the application, by setting a purging branch and a purging control valve between the stack cavity purging exhaust pipe and the drain pipe, after the system drains, the purging control valve is controlled to open, and the gas in the stack cavity purging exhaust pipe is forced to purge the drain pipe, when the time of the drain pipe purging reaches the first preset time, the purging control valve is controlled to close, this process can effectively deal with the residual hydrogen in the drain pipe, prevent the residual hydrogen from diffusing into the inside of the stack shell, ensure that the system does not appear hydrogen accumulation in the shutdown state, thereby improving the safety of the fuel cell system, ensuring the normal operation of the battery.

[0066] In some embodiments, the fuel cell system further comprises an air compressor for providing a purge gas to purge the inlet gas line to the stack cavity, and the shutdown control method further comprises: after controlling the purge control valve to close, controlling the air compressor to close for a second preset time. This is to completely purge the residual hydrogen in the exhaust, so as to avoid residual hydrogen in the system pipeline after shutdown. The second preset time can be determined according to the requirements of the system. It can be a pre-set time, or it can be determined by testing and monitoring the performance of the system. In actual operation, the length of the second preset time can be adjusted according to the purging effect and safety requirements.

[0067] In some embodiments, the shutdown control method further comprises: in response to a shutdown instruction, the shutdown instruction is usually a signal generated by a system operator or an automatic control system, indicating that the system is preparing for shutdown. Control the anode gas valve of the fuel cell system to close, which is to stop the supply of hydrogen, so as to prevent new hydrogen from entering the stack and ensure that the stack does not receive fuel during shutdown.

[0068] Further, the air compressor is controlled to continue to operate to continue to purge the stack of the fuel cell through the stack cavity purging the inlet gas line, so as to ensure that there is no residual hydrogen in the stack. Even if the stack has stopped supplying power, the purging operation still needs to be maintained until it is determined that there is no residual hydrogen. This helps to improve the safety of the system and ensures that the stack is in a safe state during shutdown.

[0069] In some embodiments, during the shutdown process, in order to discharge the waste water generated by the fuel cell, the drain valve of the fuel cell needs to be controlled to open to discharge water through the drain pipe. And the system needs to record the time of the drain pipe discharging water. This time record can be realized by using a timer or the internal clock of the system. The purpose is to monitor the duration of the waste water discharge. When the time of the drain pipe discharging water reaches a third preset time, it is determined that the drain valve discharging water is completed. The third preset time can be a pre-set time threshold, which can be adjusted according to the requirements of the system. This time is usually long enough to ensure that the waste water is completely discharged.

[0070] Figure 3 is a flow chart of system shutdown purging according to an embodiment of the present application, as Figure 3 shown, the system shutdown purging at least includes steps S10-S18, as follows:

[0071] S10, the system is shut down.

[0072] S11, air is introduced into the shell through the inlet gas pipe to purge the stack core inside the stack.

[0073] S12, control the drain valve to open to discharge water through the drain pipe.

[0074] S13, when the time of the drain pipe drainage reaches the third preset time, the drain valve is controlled to be closed.

[0075] S14, the purge control valve is controlled to be opened.

[0076] S15, the drain pipe is purged by purging the gas in the exhaust pipeline through the stack cavity.

[0077] S16, when the time of the drain pipe purge reaches the first preset time, the purge control valve is controlled to be closed.

[0078] S17, the air compressor is controlled to be closed with a second preset time delay.

[0079] S18, end.

[0080] As described above, by monitoring the drainage time, purge time and air compressor delay time, and controlling the drain valve and purge control valve to drain and purge, the fuel cell system and shutdown control method of the application can efficiently handle the residual hydrogen in the drain pipe, prevent the residual hydrogen from diffusing into the inside of the stack shell, thereby improving the safety of the system and ensuring the normal operation of the battery.

[0081] The following refers to Figure 4 a vehicle according to an embodiment of the application.

[0082] Figure 4 is a block diagram of a vehicle according to an embodiment of the application, as Figure 4 shown, the vehicle 100 includes the fuel cell system 101 described in the above embodiment.

[0083] According to the vehicle 100 of the embodiment of the application, by adopting the fuel cell system 101 described in the above embodiment, after the exhaust of the waste water generated by the fuel cell, the purge control valve is controlled to be opened, and the stack cavity purges the exhaust pipeline to pour air into the drain pipe through the purge branch to achieve forced purge of the drain pipe, thereby effectively handling the residual hydrogen in the drain pipe, preventing the residual hydrogen from diffusing into the inside of the stack shell, ensuring that the system does not accumulate hydrogen in the shutdown state, thereby improving the safety of the fuel cell system 101 and ensuring the normal operation of the battery.

[0084] In some embodiments, the vehicle 100 can be various types of vehicles, such as cars, buses, trucks, trains, etc., and the integration of the fuel cell system 101 can enable these vehicles to use fuel cells as a power source to provide clean and efficient energy.

[0085] In practical applications, the vehicle 100 configured in this way can be widely used in various fields to meet the transportation needs of different purposes, while having the characteristics of environmental protection, high efficiency and sustainability.

[0086] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example.

[0087] Although the embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, alternatives, and variations can be made thereto without departing from the principles and spirit of the present application, the scope of which is defined by the claims and their equivalents.

Claims

1. A power-off control method characterized by comprising: The fuel cell system comprises an air compressor for supplying a purge gas to an inlet gas pipeline of a stack cavity, a stack cavity purge inlet gas pipeline and a stack cavity purge outlet gas pipeline for purging a stack, and a drain pipeline, a purge branch is arranged between the stack cavity purge outlet gas pipeline and the drain pipeline, a purge control valve is arranged on the purge branch, the shutdown control method comprises: In response to a shutdown instruction, the anode inlet valve of the fuel cell system is controlled to be closed, and the air compressor is controlled to continue operating to continue purging the stack of the fuel cell through the stack cavity purge inlet gas pipeline; The drain valve of the fuel cell is controlled to be opened to drain through the drain pipeline; The time of draining through the drain pipeline is recorded; When the time of draining through the drain pipeline reaches a third preset time, it is determined that the drain valve has finished draining; In response to the fact that the stack has finished draining, the purge control valve is controlled to be opened to purge the drain pipeline through the gas in the stack cavity purge outlet gas pipeline; The time of purging the drain pipeline is recorded; When the time of purging the drain pipeline reaches a first preset time, the purge control valve is controlled to be closed.

2. The power-off control method according to claim 1, characterized by, The shutdown control method further comprises: After the purge control valve is controlled to be closed, the air compressor is controlled to be closed with a second preset time delay.

3. A fuel cell system characterized by comprising: It comprises: A stack comprising a shell and a core; A stack cavity purge inlet gas pipeline connected to the shell for introducing air into the shell to purge the gap between the shell and the core; A stack cavity purge outlet gas pipeline connected to the shell for discharging waste gas in the gap; A drain pipeline connected to the shell for discharging waste water generated by the fuel cell; A purge branch arranged between the stack cavity purge outlet gas pipeline and the drain pipeline; A purge control valve arranged on the purge branch to control the opening and closing of the purge branch; A controller for executing the shutdown control method of any one of claims 1-2.

4. The fuel cell system of claim 3, wherein The fuel cell system further comprises: A hydrogen storage container, the gas outlet of the hydrogen storage container is connected to the shell to introduce hydrogen into the shell; A hydrogen inlet valve arranged on the pipeline between the hydrogen storage container and the shell to control the introduction of hydrogen into the shell.

5. The fuel cell system of claim 4, wherein The fuel cell system further comprises: A gas-liquid separator, the inlet of the gas-liquid separator is connected to the shell, the gas outlet of the gas-liquid separator is connected to the pipeline between the hydrogen storage container and the shell, and the liquid outlet of the gas-liquid separator is connected to the drain pipeline; A drain valve arranged at the liquid outlet of the gas-liquid separator.

6. The fuel cell system of claim 5, wherein The fuel cell system further comprises: An air compressor; A intercooler, the input of the intercooler is connected to the outlet of the air compressor, and the output of the intercooler is connected to the stack cavity purge inlet gas pipeline; a humidifier, a first input port of the humidifier being connected with an output port of the intercooler, a first output port of the humidifier being connected with the casing through an air inlet pipe to introduce air into the casing, a second input port of the humidifier being connected with the casing through a first exhaust pipe to exhaust exhaust gas in the casing; a total exhaust pipe, the total exhaust pipe being connected with the second output port of the humidifier, the stack cavity purging exhaust pipe line, and the drain pipe respectively.

7. The fuel cell system of claim 6, wherein The fuel cell system further comprises: a bypass pipe line, the bypass pipe line being connected between the output port of the intercooler and the total exhaust pipe; a bypass valve, the bypass valve being arranged on the bypass pipe line.

8. A vehicle characterized by comprising: The fuel cell system comprises any one of claims 3-7. The fuel cell system comprises any one of claims 3-7.

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