Control method for fuel cell system, control unit, and storage medium

Abstract

The invention relates to a control method, a control unit and a storage medium for a fuel cell system, and the control method comprises the following steps: in response to a signal generated by shutdown of the fuel cell system, judging whether the shutdown is a fault shutdown based on the current state of the fuel cell system; when it is determined that the shutdown is not the fault shutdown, the control method is directly terminated; when it is determined that the shutdown is a fault shutdown, the safety and reliability of the fuel cell system and the current external condition of the anode discharge valve are detected, whether the safety and reliability of the fuel cell system and the current external condition of the anode discharge valve meet preset requirements or not is judged, and when the safety, reliability and the current external condition of the anode discharge valve meet the preset requirements, the fuel cell system is shut down. Opening the anode drain valve in a controlled manner; otherwise, the anode drain valve is requested and ensured to be in a closed state, and then the control method is terminated. The fuel cell system can solve the problem that cold start failure possibly occurs when the fuel cell system is shut down due to failure.

Description

Technical Field

[0001] The present application belongs to the field of fuel cells, and relates to a system control strategy, and in particular to a control method for a fuel cell system. The present application also relates to a corresponding control unit and a computer-readable storage medium. Background Art

[0002] As a clean, non-polluting form of renewable energy, fuel cell systems such as hydrogen fuel cell systems are currently being used in an increasing number of fields (such as aerospace, transportation, etc., but not limited to these). They have the characteristics of high power generation efficiency / high power density, low noise, and basically no pollution.

[0003] The cold start time and system robustness of the fuel cell system are core indicators for measuring the performance of the fuel cell system. In addition, the fuel cell system usually has an exhaust valve (hereinafter referred to as the anode exhaust valve) in its anode subsystem, which is mainly used to discharge the waste liquid (such as water) and waste gas (including fuel gas, etc.) generated during the fuel cell reaction.

[0004] When a fuel cell system shuts down normally under certain predetermined circumstances, in order to ensure the smooth subsequent cold start, a more common practice in the industry is to improve the accuracy of normal emissions from the anode exhaust valve through appropriate shutdown purges, optimized component design, and new sensors.

[0005] For abnormal system shutdown due to certain reasons (hereinafter referred to as fault shutdown), when in cold weather or environment (such as winter), if the waste liquid (such as water) generated during the fuel cell reaction and remaining in the system components (especially the exhaust valve and other components in the anode subsystem) is not discharged in time, the large amount of waste liquid remaining in the fuel cell system is at risk of freezing (such as ice), and may cause the following problems or defects: the system thawing time is prolonged, thereby increasing power consumption; the startup time is prolonged, thereby reducing the robustness of the system startup; and may even cause startup failure, thereby reducing the satisfaction of end users.

[0006] However, the above-mentioned problem has not been recognized in the current prior art, and no report on appropriate countermeasures for this situation has been found so far.

[0007] Therefore, it is necessary to improve the known prior art to provide an alternative solution that can effectively solve the above problems. Summary of the invention

[0008] In view of the above background, the purpose of the present application is to propose a control method for a fuel cell system, which can alleviate or even completely eliminate the above problems existing in the prior art.

[0009] The purpose of the present application is also to propose a control unit and a computer-readable storage medium corresponding to the above control method.

[0010] To this end, according to one aspect of the present application, a control method for a fuel cell system is provided, which is suitable for controlling the discharge of waste liquid (such as water) and waste gas (such as fuel gas, etc.) generated during the fuel cell reaction process by controlling the opening and closing of an anode exhaust valve provided in an anode subsystem (or anode side) of the fuel cell system, and the control method comprises the following steps:

[0011] In response to a signal generated by a shutdown of the fuel cell system, determining whether the shutdown is a fault shutdown based on a current state of the fuel cell system;

[0012] When it is determined that the shutdown is not a shutdown due to a fault, directly terminating the control method;

[0013] When it is determined that the shutdown is a fault shutdown, the safety and reliability of the fuel cell system and the current external conditions of the anode exhaust valve are detected and it is determined whether they all meet predetermined requirements to determine whether to open the anode exhaust valve, wherein:

[0014] When the safety and reliability of the fuel cell system and the current external conditions of the anode exhaust valve meet predetermined requirements, opening the anode exhaust valve in a controlled manner;

[0015] When any one of the safety and reliability of the fuel cell system and the current external condition of the anode exhaust valve does not meet a predetermined requirement, the anode exhaust valve is requested and ensured to be in a closed state, and then the control method is terminated.

[0016] According to another aspect of the present application, a control unit for a fuel cell system is also proposed, which is suitable for implementing the control method for a fuel cell system as described above, and can control the discharge of waste liquid and waste gas generated in the fuel cell reaction process by controlling the opening and closing of an anode exhaust valve provided in an anode subsystem of the fuel cell system, and the control unit includes:

[0017] a shutdown mode determination module configured to respond to a signal generated by a shutdown of the fuel cell system and determine whether the shutdown is a fault shutdown based on a current state of the fuel cell system; and

[0018] A control module is configured to implement the following control processes:

[0019] When it is determined that the shutdown is not a shutdown due to a fault, directly terminating the control of opening and closing the anode exhaust valve;

[0020] When it is determined that the shutdown is a fault shutdown, the safety and reliability of the fuel cell system and the current external conditions of the anode exhaust valve are detected and it is determined whether they all meet predetermined requirements to determine whether to open the anode exhaust valve, wherein:

[0021] When the safety and reliability of the fuel cell system and the current external conditions of the anode exhaust valve are determined to meet predetermined requirements, opening the anode exhaust valve in a controlled manner;

[0022] When any one of the safety and reliability of the fuel cell system and the current external condition of the anode exhaust valve does not meet a predetermined requirement, the anode exhaust valve is requested and ensured to be in a closed state.

[0023] According to another aspect of the present application, a computer-readable storage medium (or machine-readable storage medium) is also proposed, which stores executable instructions (or program instructions). When the executable instructions are executed by a processor, the processor executes the control method as described above.

[0024] As can be seen from the above description, the present application proposes a control method, a control unit and a corresponding computer-readable storage medium for a fuel cell system, which can realize effective anode-side discharge (i.e., discharge and exhaust of the anode discharge valve) of the fuel cell system under certain special shutdown (fault shutdown) conditions, and can solve the problems of freezing of the anode discharge valve, delay in the next cold start time or start failure that may occur in the existing fuel cell system under the above conditions in a simple, reliable and low-cost manner, and can effectively reduce the system power consumption and improve the robustness of the system cold start. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The features, advantages and other aspects of the present application will be more clearly understood through the following more detailed description of the present application given with reference to the accompanying drawings and in combination with exemplary embodiments. In the accompanying drawings:

[0026] Figure 1 A schematic diagram of a typical configuration of a conventional hydrogen fuel cell system;

[0027] Figure 2 is a basic logic or flow chart of a control method for a fuel cell system according to an exemplary embodiment of the present application;

[0028] Figure 3 is a schematic diagram of a control unit for a fuel cell system according to an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0029] The following describes in detail the specific embodiments of the present application with reference to the accompanying drawings. It should be understood that the embodiments and related descriptions given herein should be understood as exemplary and do not constitute limitations on the present application.

[0030] In addition, it should be noted that, for the sake of simplicity and in order to more conveniently understand the design points or substantial features of the present application, the specification of the present application and its drawings focus on describing or illustrating the contents related to the main design points or principles of the present application, while omitting or simplifying the contents of other parts. Regarding the basic principles, control processes and other details of these omitted parts, they belong to the known technologies in the art or those skilled in the art can be specifically applied according to existing knowledge and application environment, etc., and will not be repeated here, nor will they be illustrated in detail. In other words, methods (such as control processes), techniques and structures well-known in the art are not described in detail to avoid unnecessarily blurring the core or essence of the present application.

[0031] First of all, it should be pointed out that in the following description, in order to facilitate a clearer understanding of the principles and technical solutions of the present application, the hydrogen fuel cell system will be used as an example to exemplarily describe the application, control method or process of the application, but this does not mean any limitation on the present application. On the contrary, the present application is not only applicable to hydrogen fuel cell systems, but is also obviously applicable to any other type of fuel cell system, such as solid oxide fuel cell systems, alkaline fuel cell systems, etc. In addition, the fuel cell system involved in the present application can be widely used in aerospace, transportation (such as the automotive industry) and other fields.

[0032] like Figure 1 As shown, according to a typical configuration of a hydrogen fuel cell system which is an example of the fuel cell system of the present application, the hydrogen fuel cell system 1 has a fuel cell stack 2 including a cathode and an anode, and generally mainly includes a hydrogen subsystem 3, an air subsystem 4 and a cooling subsystem 5, wherein the hydrogen subsystem 3 may also be referred to as an anode subsystem, and the air subsystem 4 may also be referred to as a cathode subsystem.

[0033] from Figure 1 As can be seen in FIG, as a typical configuration of the anode subsystem of a traditional hydrogen fuel cell system, it mainly includes a hydrogen injection device 31, a water collection and separation device (or a water-gas separation device) 32, a hydrogen circulation and injection device 33, an anode exhaust valve (for example, including an exhaust valve 34 and a drain valve 35, which can be solenoid valves), and an exhaust safety monitoring device 36. Figure 1 In the example shown, the anode exhaust valve is composed of a separate exhaust valve 34 and a drain valve 35, but it is obviously not limited thereto. In other words, the anode exhaust valve can also be designed as an integrated structure in which the exhaust and drain functions are integrated.

[0034] In addition, from Figure 1 It can be seen that the hydrogen from the hydrogen source can be transported to the anode side inlet of the fuel cell stack 2 of the hydrogen fuel cell system via the hydrogen injection device 31. The water collecting and separating device 32 is respectively connected to the anode side outlet of the fuel cell stack and the hydrogen circulation and injection device 33, the exhaust valve 34, and the drain valve 35 fluid. The waste liquid (water) and waste gas (including hydrogen) generated during the fuel cell reaction are collected and separated by the water collecting and separating device 32. A part of the gas (hydrogen) can be returned to the anode side inlet of the fuel cell stack 1 via the hydrogen circulation and injection device 33 for recycling (therefore, the hydrogen injection device 31, the water collecting and separating device 32, the hydrogen circulation and injection device 33 and the fuel cell stack 2 together form an anode loop), and the remaining waste gas and waste liquid can be discharged into the exhaust valve 34 and the drain valve 35 respectively. Figure 2 The exhaust pipeline is, for example, in fluid communication with the exhaust gas safety monitoring device 36, and the exhaust gas collected therein can be finally discharged into the atmosphere through the first pipeline L1 under the monitoring of the exhaust gas safety monitoring device 7. In addition, in the portion between the exhaust gas safety monitoring device 36 and the exhaust valve 34 and the drain valve 35, the exhaust pipeline can also receive air from the air subsystem (not shown) and pass through Figure 1 The first pipeline L2 shown by the dotted line in FIG. 1 transports waste liquid (water) and waste gas (which contains air, etc.).

[0035] The above diagram only illustrates and describes a typical configuration of a conventional hydrogen fuel cell system (especially its hydrogen subsystem or anode subsystem). Obviously, it is easy to understand that the specific structure and configuration of the hydrogen fuel cell system are not limited to this, but can be changed or adjusted in any feasible manner according to actual conditions and specific needs. In addition, the specific structure, working principle, control process, etc. of the fuel cell system and its related components described above are all known in the art, so for the sake of simplicity, they will not be repeated here.

[0036] As can be seen from the foregoing description, an anode exhaust valve is usually provided in the anode subsystem (or hydrogen subsystem) of the hydrogen fuel cell system as an example of the fuel cell system of the present application. As a key component in the hydrogen fuel cell system, the anode exhaust valve is mainly used to discharge the waste liquid (water) and waste gas (including hydrogen) generated during the hydrogen fuel cell reaction. The present application mainly revolves around the control strategy of the anode exhaust valve, a key component in the fuel cell system, which will be described in detail below.

[0037] The present application mainly relates to the optimization of the control strategy of the anode exhaust valve (in other words, the exhaust on the anode side of the fuel cell system), which mainly relies on the anode subsystem in the fuel cell system.

[0038] As mentioned above, in the known prior art, it has not been recognized that when the fuel cell system has an abnormal shutdown (or fault shutdown), there may be risks due to the failure to discharge the waste liquid generated during the fuel cell reaction process in time, and no corresponding countermeasures have been given. Therefore, it is impossible to solve the problem that the fuel cell system may have a low-temperature start-up failure under the above-mentioned operating conditions.

[0039] Based on the above background, the present application proposes an improved control method for a fuel cell system, and its main design principles or working processes are roughly summarized as follows.

[0040] According to one aspect of the present application, a control method for a fuel cell system is provided, which is suitable for controlling the discharge of waste liquid (for example, water in the case of a hydrogen fuel cell system) and waste gas (for example, hydrogen in the case of a hydrogen fuel cell system, etc.) generated during a fuel cell reaction by controlling the opening and closing of an anode exhaust valve provided in an anode subsystem (or anode side) of the fuel cell system, and the control method comprises the following steps:

[0041] In response to a signal generated by a shutdown of the fuel cell system (for example, when a shutdown event is detected by a sensor or the system sends a shutdown signal), determining whether the shutdown is a fault shutdown based on a current state of the fuel cell system;

[0042] When it is determined that the shutdown is not a shutdown due to a fault, the control method may be directly terminated; or

[0043] When it is determined that the shutdown is a fault shutdown, the safety and reliability of the fuel cell system and the current external conditions of the anode exhaust valve are detected and it is determined whether they all meet predetermined requirements to determine whether to open the anode exhaust valve, wherein:

[0044] When the safety and reliability of the fuel cell system and the current external conditions of the anode exhaust valve meet predetermined requirements, opening the anode exhaust valve in a controlled manner;

[0045] When any one of the safety and reliability of the fuel cell system and the current external condition of the anode exhaust valve does not meet a predetermined requirement, the anode exhaust valve is requested and ensured to be in a closed state, and then the control method is terminated.

[0046] According to a feasible implementation mode, determining whether the shutdown is a fault shutdown includes: determining whether the shutdown is a shutdown without purge by detecting whether there is a flow of purge gas in the fuel cell system (on the anode side or the cathode side), and when the shutdown is determined to be a shutdown without purge, the shutdown is determined to be a fault shutdown.

[0047] The design concept or starting point of the above-mentioned feasible implementation methods or examples is that, in the known prior art, in the case of normal shutdown, appropriate shutdown purge is usually used to improve the accuracy of normal emissions and ensure the smooth progress of subsequent cold start. In this case, it can be judged whether the shutdown is a fault shutdown based on whether there is a flow of purge gas in the fuel cell system, but it is obviously not limited to this. For example, it can be judged whether the shutdown is a fault shutdown based on whether a normal shutdown request is received or the type of shutdown signal issued by the system.

[0048] According to a feasible implementation mode, the exhaust gas contains fuel gas (for example, hydrogen), and detecting and judging whether the safety of the fuel cell system meets predetermined requirements includes: detecting the concentration of the fuel gas in the exhaust pipeline connected to the anode exhaust valve fluid and judging whether it is less than or equal to a safety threshold value to avoid possible risks such as explosion.

[0049] According to a feasible implementation manner, detecting and judging whether the reliability of the fuel cell system meets predetermined requirements includes:

[0050] Measuring the anode-cathode pressure difference of the fuel cell system and determining whether it is less than or equal to a predetermined upper pressure difference threshold (the predetermined upper pressure difference threshold may be obtained based on system calibration or model calculation, for example); and

[0051] The working state of the anode exhaust valve is detected to determine whether a fault (such as a stuck fault) occurs therein.

[0052] According to a feasible implementation manner, detecting and judging whether the reliability of the fuel cell system meets a predetermined requirement further includes:

[0053] The working state of the air compressor in the cathode subsystem of the fuel cell system is detected to determine whether it is operating normally.

[0054] According to a feasible implementation manner, detecting and judging whether the current external condition of the anode exhaust valve meets the predetermined requirement includes:

[0055] Measuring the upstream and downstream pressure difference of the anode exhaust valve and determining whether it is greater than a predetermined pressure difference lower limit threshold (the predetermined pressure difference lower limit threshold may be obtained based on system calibration or through experiments, for example); and

[0056] The external environment temperature of the anode exhaust valve is detected and it is determined whether the external environment temperature is greater than a predetermined temperature lower limit threshold.

[0057] According to a feasible implementation manner, the control method further includes:

[0058] During the opening of the anode exhaust valve, simultaneously controlling the gas flow on the anode side or cathode side of the fuel cell system to perform a fault shutdown purge; and / or

[0059] After the anode exhaust valve is opened, the opening time of the anode exhaust valve is calculated and it is determined whether it exceeds a predetermined time threshold (for example, the maximum allowed opening time, which can be obtained by calibration or by using a model based on the upstream and downstream pressure difference of the anode exhaust valve and the external ambient temperature of the anode exhaust valve), wherein:

[0060] When the opening time of the anode exhaust valve exceeds a predetermined time threshold, requesting and ensuring that the anode exhaust valve is in a closed state, and then terminating the control method;

[0061] When the opening time of the anode exhaust valve does not exceed the predetermined time threshold, the control method continues and returns to the step of determining whether to open the anode exhaust valve.

[0062] According to a feasible implementation mode, the control method further includes: detecting the change of the gas flow in the anode loop of the anode subsystem within a certain period of time and judging whether it is constant, thereby judging whether the operation state of the anode subsystem is stable, wherein:

[0063] When it is determined that the operating state of the anode subsystem is stable, continuing the process of the control method;

[0064] When it is determined that the operating state of the anode subsystem is unstable, the anode exhaust valve is requested and ensured to be in a closed state, and then the control method is terminated.

[0065] Combine the following Figure 2 Describes a fuel cell system (with Figure 1 A specific example of the logic or steps of a method for controlling an anode exhaust valve of a hydrogen fuel cell system (taking the hydrogen fuel cell system shown in FIG. 1 as an example) is provided.

[0066] like Figure 2 As shown, the control method for a fuel cell system according to an exemplary embodiment of the present application mainly includes the following steps or processes:

[0067] First, when a shutdown event occurs in the fuel cell system, in response to a signal generated by the shutdown event, the fuel cell system starts determining whether the shutdown is a fault shutdown (step S1), wherein as a non-limiting example, the determination of whether the shutdown is a fault shutdown can be performed by detecting a signal generated by the shutdown event in the fuel cell system (e.g. Figure 1The shutdown is determined based on whether there is a flow of purge gas in the anode subsystem or the hydrogen subsystem of the control unit. When there is no flow of purge gas, the shutdown is determined to be a shutdown without purge, and thus the shutdown can be determined to be a fault shutdown.

[0068] Based on the judgment result in step S1, when it is determined that the shutdown is not a fault shutdown (in other words, a non-fault shutdown), that is, the judgment result is no (N), the control method is directly terminated (that is, proceed or jump to step S9 to be described below); on the contrary, when the judgment result is yes (Y), the control method continues to step S2 to be described below.

[0069] At step S2, for example, by detecting Figure 1 The change of the hydrogen flow rate near the outlet of the hydrogen injection device 31 or the hydrogen circulation and injection device 33 shown in the figure within a certain period of time and judging whether it is constant, thereby judging the anode subsystem ( Figure 1 When it is determined that the operating state of the anode subsystem is stable, that is, the judgment result is yes (Y), the process of the control method continues, that is, proceeds to step S3 to be described below; on the contrary, when the judgment result is no (N), it is requested and ensured that the anode exhaust valve is in a closed state (that is, proceeds or jumps to step S8), and then the control method is terminated (step S9).

[0070] It should be noted that, according to an exemplary embodiment of the present application, step S2 is optional (ie, can be omitted in some cases).

[0071] Next, the control method will proceed to the determination and implementation stage of the main or key opening strategy of the anode exhaust valve, and its basic principle or process can be briefly described as follows: by detecting the safety and reliability of the fuel cell system and the current external conditions of the anode exhaust valve and judging whether they all meet the predetermined requirements, it is determined whether to open the anode exhaust valve, wherein when the safety and reliability of the fuel cell system and the current external conditions of the anode exhaust valve meet the predetermined requirements, the anode exhaust valve is opened in a controlled manner; otherwise, the anode exhaust valve is requested and ensured to be in a closed state, and then the control method is terminated. The following is a further detailed description of this with the help of steps S3-S5 given by way of example.

[0072] At step S3, for example, the concentration of the fuel gas (hydrogen in the case of a hydrogen fuel cell system) in the exhaust pipeline in fluid communication with the anode exhaust valve can be detected by the exhaust safety monitoring device 36 and judged whether it is less than or equal to the safety threshold, and thereby judged whether the safety of the fuel cell system meets the predetermined requirements (whether it complies with safety assurance) to prevent unexpected safety accidents (such as hydrogen explosions, etc.). If it is determined that the safety of the fuel cell system meets the predetermined requirements, that is, the judgment result is yes (Y), the process of the control method continues, that is, proceeds to step S4 to be described below; on the contrary, when the judgment result is no (N), it will be necessary to request and ensure that the anode exhaust valve is in a closed state (that is, proceed or jump to step S8), and then terminate the control method (step S9).

[0073] At step S4, whether the opening of the anode exhaust valve is supported can be further determined by the current system state, the state of the components controlled by the system, and the sensor feedback information, that is, whether the reliability of the fuel cell system meets the predetermined requirements, which may include (but not limited to) measuring the anode-cathode pressure difference of the fuel cell system and determining whether it is less than or equal to a predetermined pressure difference upper limit threshold (for example, to avoid unnecessary mechanical damage to the fuel cell stack), detecting the working state of the anode exhaust valve and determining whether it fails (for example, a stuck failure), and optionally detecting the working state of the air compressor in the cathode subsystem of the fuel cell system and determining whether it operates normally, the purpose of which is, for example, to prevent the following situations from occurring: the opening of the anode exhaust valve cannot be carried out normally; the reliability (or safety) of the fuel cell stack cannot be met; the amount of air used to dilute the hydrogen concentration is insufficient. If it is determined that the reliability of the fuel cell system meets the predetermined requirements, that is, the judgment result is yes (Y), the process of the control method continues, that is, proceeds to step S5 to be described below; on the contrary, when the judgment result is no (N), it is necessary to request and ensure that the anode exhaust valve is in a closed state (that is, proceed or jump to step S8), and then terminate the control method (step S9).

[0074] At step S5, it is possible to further determine whether the opening of the anode exhaust valve is supported by the current external conditions of the anode exhaust valve, that is, to determine whether the current external conditions of the anode exhaust valve meet the predetermined requirements, which may include (but not limited to): measuring the upstream and downstream pressure difference of the anode exhaust valve and determining whether it is greater than the predetermined pressure difference lower limit threshold and detecting the external ambient temperature of the anode exhaust valve and determining whether it is greater than the predetermined temperature lower limit threshold. In other words, step S5 is mainly used to determine whether the upstream and downstream pressure difference of the anode exhaust valve is sufficient, whether the ambient temperature is appropriate, whether there is a risk of icing, etc. If it is determined that the current external conditions of the anode exhaust valve meet the predetermined requirements, that is, the judgment result is yes (Y), the process of the control method continues, that is, proceeding to step S6 to be described below; on the contrary, when the judgment result is no (N), it is necessary to request and ensure that the anode exhaust valve is in a closed state (that is, proceed or jump to step S8), and then terminate the control method (step S9).

[0075] It should be noted that, for those skilled in the art, it is obvious that the sequence and specific contents of the above steps S3-S5 are not limited to the examples described above, but can be appropriately changed according to specific circumstances or actual needs. For example, step S4 can be performed first, followed by steps S3 and S5; or step S5 can be performed first, followed by steps S3 and S4. In addition, the specific contents of the above steps S3-S5 (such as the setting of detection items or judgment conditions, etc.) can also be appropriately increased or decreased according to specific circumstances or actual needs. For the sake of simplicity, no detailed examples are given here.

[0076] Next, at step S6, the anode exhaust valve is requested and ensured to be opened for a period of time to discharge waste liquid (water in the case of a hydrogen fuel cell system) and waste gas generated during the fuel cell reaction and accumulated at the anode exhaust valve.

[0077] It should be pointed out that in Figure 1 In the example shown, the anode exhaust valve is composed of an exhaust valve 34 and a drain valve 35 that are separated from each other. In this case, it is necessary to control the opening and closing of the exhaust valve 34 and the drain valve 35 respectively. In addition, as mentioned above, the anode exhaust valve can also adopt an integrated structural design in which the exhaust and drain functions are integrated. In this case, it is only necessary to control the opening and closing of the integrated anode exhaust valve.

[0078] Subsequently, in step S7, at least one of the following control processes may be selectively implemented:

[0079] During the period when the anode exhaust valve is opened in a controlled manner, the gas flow on the anode side or the cathode side of the fuel cell system is controlled to perform fault shutdown purge (this process can be performed, for example, with reference to the normal shutdown purge process in the known prior art, but is not limited thereto); and

[0080] During the opening of the anode exhaust valve in a controlled manner, the opening time of the anode exhaust valve is calculated and it is determined whether it exceeds a predetermined time threshold (which can be obtained, for example, by system calibration or by calculation with the aid of a model, but is not limited thereto), wherein when the opening time of the anode exhaust valve exceeds the predetermined time threshold, it is requested and ensured that the anode exhaust valve is in a closed state (step S8), and then the control method is terminated (step S9); when the opening time of the anode exhaust valve does not exceed the predetermined time threshold, the control method continues and returns to step S3.

[0081] It should be noted that, according to an exemplary embodiment of the present application, step S7 is optional (i.e., can be omitted in some cases). In this case, the period of time involved in step S6 can be set to a fixed value, which can be determined based on experiments or model calculations (e.g., can be several seconds or seconds), but is not limited thereto.

[0082] Next, in step S8 , it is requested and ensured that the anode exhaust valve is in a closed state.

[0083] Subsequently, in step S9 , when it is detected that the anode exhaust valve is in the closed state, the control method is terminated (ie, the control process of the present application is ended).

[0084] In addition, combined Figure 3 It can be seen that according to another aspect of the present application, a control unit 6 for a fuel cell system is also proposed, which is suitable for implementing the control method for a fuel cell system as described above, and can control the discharge of waste liquid and waste gas generated in the fuel cell reaction process by controlling the opening and closing of the anode discharge valve provided in the anode subsystem of the fuel cell system. The control unit 6 includes:

[0085] a shutdown mode determination module 61 configured to respond to a signal generated by a shutdown of the fuel cell system and determine whether the shutdown is a fault shutdown based on a current state of the fuel cell system; and

[0086] The control module 62 is configured to implement the following control process:

[0087] When it is determined that the shutdown is not a shutdown due to a fault, terminating (for example, directly terminating) the control of opening and closing the anode exhaust valve;

[0088] When it is determined that the shutdown is a fault shutdown, the safety and reliability of the fuel cell system and the current external conditions of the anode exhaust valve are detected and it is determined whether they all meet predetermined requirements to determine whether to open the anode exhaust valve, wherein:

[0089] When the safety and reliability of the fuel cell system and the current external conditions of the anode exhaust valve are determined to meet predetermined requirements, opening the anode exhaust valve in a controlled manner;

[0090] When any one of the safety and reliability of the fuel cell system and the current external condition of the anode exhaust valve does not meet a predetermined requirement, the anode exhaust valve is requested and ensured to be in a closed state.

[0091] According to another aspect of the present application, a computer-readable storage medium (i.e., a non-temporary computer-readable storage medium) is also proposed, which stores executable instructions (or program instructions), and when the executable instructions are executed by a processor, the processor executes the control method as described above. It can be seen from the above description that the control method of the present application can reliably and conveniently achieve its intended purpose, and can solve many problems that may occur in the prior art under the above working conditions in a simple, reliable and low-cost manner, and effectively reduce system power consumption and improve the robustness of system cold start.

[0092] The control method of the present application can be executed with the aid of the control unit of the present application, and the various technical features or contents described for the control method are also applicable to the control unit. The various steps and technical details of the control method described above can be stored in the control unit in the form of software, or implemented in the form of a combination of software and hardware. In addition, as mentioned above, the present application also relates to a computer-readable storage medium storing executable instructions, which, when executed, cause a processor to execute the above control method.

[0093] The present application has been described in detail above in conjunction with specific embodiments. Obviously, as mentioned above, the embodiments described above and shown in the accompanying drawings should be understood as exemplary and do not constitute a limitation to the present application. For those skilled in the art, various modifications or changes can be made to the present application without departing from the spirit of the present application. Obviously, these modifications or changes do not depart from the scope of the present application.

Claims

1. A control method for a fuel cell system, which is suitable for controlling the discharge of waste liquid and waste gas generated during the fuel cell reaction process by controlling the opening and closing of an anode exhaust valve provided in an anode subsystem of the fuel cell system, the control method comprising the following steps: In response to a signal generated by a shutdown of the fuel cell system, determining whether the shutdown is a fault shutdown based on a current state of the fuel cell system; When it is determined that the shutdown is not a shutdown due to a fault, directly terminating the control method; When it is determined that the shutdown is a fault shutdown, the safety and reliability of the fuel cell system and the current external conditions of the anode exhaust valve are detected and it is determined whether they all meet predetermined requirements to determine whether to open the anode exhaust valve, wherein: When the safety and reliability of the fuel cell system and the current external conditions of the anode exhaust valve meet predetermined requirements, opening the anode exhaust valve in a controlled manner; When any one of the safety and reliability of the fuel cell system and the current external condition of the anode exhaust valve does not satisfy a predetermined requirement, the anode exhaust valve is requested and ensured to be in a closed state, and then the control method is terminated.

2. The control method for a fuel cell system according to claim 1, wherein: Determining whether the shutdown is a fault shutdown includes: Whether the shutdown is a shutdown without purge is determined by detecting whether there is a flow of purge gas in the fuel cell system, and when the shutdown is determined to be a shutdown without purge, the shutdown is determined to be a fault shutdown.

3. The control method for a fuel cell system according to claim 1, wherein: The exhaust gas contains fuel gas, and judging whether the safety of the fuel cell system meets the predetermined requirements includes: The concentration of the fuel gas in the exhaust pipeline in fluid communication with the anode exhaust valve is detected and judged whether the concentration of the fuel gas is less than or equal to a safety threshold.

4. The control method for a fuel cell system according to claim 1, wherein: Detecting and judging whether the reliability of the fuel cell system meets predetermined requirements includes: Measuring the anode-cathode pressure difference of the fuel cell system and determining whether it is less than or equal to a predetermined pressure difference upper limit threshold; and The working state of the anode exhaust valve is detected to determine whether it fails.

5. The control method for a fuel cell system according to claim 4, wherein: Detecting and judging whether the reliability of the fuel cell system meets the predetermined requirements also includes: The working state of the air compressor in the cathode subsystem of the fuel cell system is detected to determine whether it is operating normally.

6. The control method for a fuel cell system according to claim 1, wherein: Detecting and judging whether the current external condition of the anode exhaust valve meets the predetermined requirements includes: Measuring the upstream and downstream pressure difference of the anode exhaust valve and determining whether it is greater than a predetermined pressure difference lower limit threshold; as well as The external environment temperature of the anode exhaust valve is detected and it is determined whether the external environment temperature is greater than a predetermined temperature lower limit threshold.

7. The control method for a fuel cell system according to claim 1, further comprising: During the opening of the anode exhaust valve, simultaneously controlling the gas flow on the anode side or the cathode side of the fuel cell system to perform fault shutdown purge; and / or After the anode exhaust valve is opened, the opening time of the anode exhaust valve is calculated and it is determined whether it exceeds a predetermined time threshold, wherein: When the opening time of the anode exhaust valve exceeds a predetermined time threshold, requesting and ensuring that the anode exhaust valve is in a closed state, and then terminating the control method; When the opening time of the anode exhaust valve does not exceed the predetermined time threshold, the control method continues and returns to the step of determining whether to open the anode exhaust valve.

8. The control method for a fuel cell system according to claim 1, further comprising: Before determining whether to open the anode exhaust valve, the change of the gas flow in the anode loop of the anode subsystem within a certain period of time is detected and it is determined whether it is constant, thereby determining whether the operating state of the anode subsystem is stable, wherein: When it is determined that the operating state of the anode subsystem is stable, continuing the process of the control method; When it is determined that the operating state of the anode subsystem is unstable, the anode exhaust valve is requested and ensured to be in a closed state, and then the control method is terminated.

9. A control unit for a fuel cell system, which is suitable for implementing the control method for a fuel cell system according to any one of claims 1 to 8, and can control the discharge of waste liquid and waste gas generated during the fuel cell reaction process by controlling the opening and closing of an anode exhaust valve provided in an anode subsystem of the fuel cell system, the control unit comprising: A shutdown mode determination module, configured to respond to a signal generated by a shutdown of the fuel cell system and determine whether the shutdown is a fault shutdown based on a current state of the fuel cell system; as well as The control module is configured to implement the following control processes: When it is determined that the shutdown is not a shutdown due to a fault, directly terminating the control of opening and closing the anode exhaust valve; When it is determined that the shutdown is a fault shutdown, the safety and reliability of the fuel cell system and the current external conditions of the anode exhaust valve are detected and it is determined whether they all meet predetermined requirements to determine whether to open the anode exhaust valve, wherein: When the safety and reliability of the fuel cell system and the current external conditions of the anode exhaust valve are determined to meet predetermined requirements, opening the anode exhaust valve in a controlled manner; When any one of the safety and reliability of the fuel cell system and the current external condition of the anode exhaust valve does not meet a predetermined requirement, the anode exhaust valve is requested and ensured to be in a closed state.

10. A computer-readable storage medium storing executable instructions, which, when executed by a processor, enables the processor to execute the control method for a fuel cell system according to any one of claims 1 to 8.

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