Cold start method and device of fuel cell system, fuel cell system and vehicle

Abstract

The invention provides a cold start method and device for a fuel cell system, the fuel cell system and a vehicle, and the method comprises the steps: when the rotating speed of a hydrogen circulating pump is smaller than a preset rotating speed and the duration of the rotating speed smaller than the preset rotating speed is longer than a preset duration, determining a target heating temperature for heating a cooling liquid according to a current environment temperature, determining an optimal hydrogen pressure interval when the galvanic pile does not have a single low phenomenon according to the target heating temperature, determining a target valve opening and closing frequency with the shortest valve opening and closing frequency according to the target heating temperature and the optimal hydrogen pressure interval, heating the cooling liquid to the target heating temperature, and then controlling the galvanic pile to adopt an ejector mode to carry out loading, the valve frequency is adjusted according to the target valve opening and closing frequency until the current rotating speed of the hydrogen circulating pump is larger than or equal to the preset rotating speed. According to the method, the problem that the hydrogen pump is frozen after cold start of the fuel cell system is effectively avoided, and the system cold start success and the working efficiency and service life requirements of the system under all working conditions are ensured.

Description

Technical Field

[0001] The present application relates to the field of fuel cells, and more specifically, to a cold start method and device for a fuel cell system, a fuel cell system, and a vehicle. Background Art

[0002] Low-temperature starting performance is a very important indicator of the fuel cell system. Due to the limitations of the system architecture and the performance of the anode components, the hydrogen circulation pump may occasionally freeze and fail to start when the system is started at low temperatures, resulting in limited use of the hydrogen circulation pump and even system failure requiring repair.

[0003] In the related art, in the face of the problem of hydrogen circulation pump freezing in a low temperature environment, a low-frequency, high-current method is chosen to increase the torque to achieve the purpose of defrosting, thereby starting the fuel cell system.

[0004] However, the current value required to break the ice of the hydrogen circulation pump is difficult to control. If the current is too large, it may cause damage to the circuit board. If the current is too small, the fuel cell system may not be started normally in a low temperature environment. Therefore, this solution has poor stability and poses safety hazards. Summary of the invention

[0005] The present application provides a cold start method, device, fuel cell system and vehicle for a fuel cell system. The method can effectively avoid the problem of hydrogen pump freezing after the fuel cell system is cold started, ensure the successful cold start of the system under all working conditions and the efficiency and life requirements of the system.

[0006] In a first aspect, a cold start method for a fuel cell system is provided, the method comprising:

[0007] Get the current speed and current ambient temperature of the hydrogen circulation pump;

[0008] If the current speed is less than the preset speed and the first duration of the current speed being less than the preset speed is greater than the preset duration, a target heating temperature for heating the coolant with the shortest time is determined according to the current ambient temperature, and an optimal hydrogen pressure interval when the fuel cell stack of the fuel cell system does not have a single low phenomenon is determined according to the target heating temperature, and a target valve opening and closing frequency with the shortest valve opening and closing frequency is determined according to the target heating temperature and the optimal hydrogen pressure interval;

[0009] The coolant is heated according to the target heating temperature, and after the cooling temperature reaches the target heating temperature, the fuel cell system stack is controlled to adopt a preset ejector mode for loading, and the valve frequency is adjusted according to the target valve opening and closing frequency until the current speed of the hydrogen circulation pump is greater than or equal to the preset speed.

[0010] Through the above technical scheme, the present application provides the conditions for judging whether the hydrogen circulation pump is frozen, that is, the current speed of the hydrogen circulation pump is less than a certain value, and the duration of the speed being less than the certain value is too long; furthermore, the present application fully considers the current ambient temperature, and determines the shortest time for heating the coolant to the target heating temperature within the temperature range in which it is located, and thereby determines the optimal hydrogen pressure range when the stack of the fuel cell system does not have a single low phenomenon, thereby determining the shortest target valve opening and closing frequency, and in order to complete the hydrogen cycle, the ejector is used to pull the load and adjust the valve frequency until the speed of the hydrogen circulation pump meets its operating requirements. Therefore, the present application utilizes the hydrogen circulation pump and the ejector, the anti-icing design in the structural design and layout of the fuel cell system, and the system cold start strategy, effectively avoiding the freezing of the hydrogen circulation pump in a low temperature environment, realizing the system cold start control strategy under all working conditions, and ensuring the working efficiency and service life of the fuel cell system.

[0011] In combination with the first aspect, in some possible implementations, determining the target heating temperature for heating the coolant in the shortest time based on the current ambient temperature includes: based on the current ambient temperature, determining a first target calibration table from a plurality of preset heating time calibration tables, wherein the first target calibration table includes a plurality of heating temperatures and the heating time for heating the coolant to each heating temperature; and using the heating temperature corresponding to the shortest heating time in the first target calibration table as the target heating temperature.

[0012] Through the above technical solution, the present application sets up multiple heating time calibration tables, each of which includes multiple coolant heating temperatures and the corresponding heating time at each heating temperature. The present application can match a target calibration table based on the temperature range of the current environment obtained, and select the heating temperature corresponding to the shortest heating time to heat the coolant to the target temperature in the calibration table. Therefore, the present application fully considers the impact of the current ambient temperature on the start-up of the fuel cell system, and obtains the heating temperature of the coolant in the current ambient temperature range, and the heating time is the shortest. Therefore, the present application can heat the coolant in the shortest time, so that the fuel cell system heats up quickly.

[0013] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, before determining the first target calibration table from the preset multiple heating time calibration tables based on the current ambient temperature, it also includes: determining multiple ambient temperature intervals to be calibrated and multiple heating temperatures; based on each ambient temperature interval to be calibrated, recording the heating time for heating the coolant to each heating temperature at the multiple heating temperatures; and obtaining the preset multiple heating time calibration tables according to the multiple ambient temperature intervals to be calibrated, the multiple heating temperatures and the heating time for heating the coolant to each heating temperature.

[0014] Through the above technical scheme, the present application provides a method for obtaining multiple heating time calibration tables. After determining multiple ambient temperature intervals to be calibrated, multiple heating temperatures required for heating the coolant are set in each temperature interval, and then the heating time for heating the coolant to the target temperature at each heating temperature can be recorded. Therefore, the present application can obtain a more accurate heating time calibration table based on the ambient temperature, which greatly improves the heating efficiency of the coolant and effectively avoids the problem of safety hazards caused by excessively high or low temperatures.

[0015] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the optimal hydrogen pressure interval when the fuel cell system's stack does not have a single low phenomenon is determined according to the target heating temperature, and the target valve opening and closing frequency with the shortest valve opening and closing frequency is determined according to the target heating temperature and the optimal hydrogen pressure interval, including: based on the target heating temperature, determining at least one target hydrogen pressure interval when the fuel cell system's stack does not have a single low phenomenon, wherein there is no intersection between the at least one target hydrogen pressure interval; determining the minimum hydrogen pressure in the at least one target hydrogen pressure interval, and taking the target hydrogen pressure interval corresponding to the minimum hydrogen pressure as the optimal hydrogen pressure interval; based on the target heating temperature and the optimal hydrogen pressure interval, determining a second target calibration table from a plurality of preset stack single low calibration tables, wherein the second target calibration table includes a calibrated hydrogen pressure interval and at least one group of valve opening and closing frequencies corresponding to the calibrated hydrogen pressure interval; taking a group of valve opening and closing frequencies in the second target calibration table in which the fuel cell system's stack does not have a single low phenomenon and has the shortest valve opening and closing frequency as the target valve opening and closing frequency.

[0016] Through the above technical scheme, the present application can determine one or more target hydrogen pressure intervals according to the target heating temperature obtained in the above embodiment, and the target hydrogen pressure interval in the embodiment of the present application can avoid the single low phenomenon of the fuel cell stack, and can effectively avoid damage to the system caused by fuel cell stack failure; furthermore, the present application can determine the minimum hydrogen pressure among multiple target hydrogen pressure intervals, and use the pressure interval where the minimum hydrogen pressure is located as the optimal hydrogen pressure interval; in addition, the present application provides multiple fuel cell stack single low calibration tables, and the target calibration table that best matches the current system state can be obtained according to the target heating temperature and the optimal hydrogen pressure interval. Therefore, the present application can select a group of valve opening and closing frequencies with the shortest opening and closing frequency in the target calibration table as the target valve opening and closing frequency, and at this time the fuel cell stack will not experience the single low phenomenon.

[0017] In combination with the first aspect and the above-mentioned implementation methods, in certain possible implementation methods, before determining the second target calibration table from the preset multiple fuel cell stack single low calibration tables based on the target heating temperature and the optimal hydrogen pressure range, it also includes: determining multiple hydrogen pressure ranges; in each of the ambient temperature ranges to be calibrated, based on each heating temperature, recording whether the single low phenomenon occurs in the fuel cell stack at each group of valve opening and closing frequencies corresponding to each hydrogen pressure range; obtaining the preset multiple fuel cell stack single low calibration tables according to whether the single low phenomenon occurs in the fuel cell stack at the multiple heating temperatures, the multiple hydrogen pressure ranges and each group of valve opening and closing frequencies corresponding to each hydrogen pressure range.

[0018] Through the above technical scheme, the present application provides a method for obtaining multiple fuel cell stack single low calibration tables, by calibrating multiple hydrogen pressure intervals, and recording whether the fuel cell stack has a single low phenomenon under each valve opening and closing frequency, thereby obtaining multiple fuel cell stack single low calibration tables, thereby adjusting the hydrogen pressure and valve frequency of the fuel cell system according to the calibration table, and the fuel cell stack will not have a single low phenomenon, which greatly improves the service life of the fuel cell system.

[0019] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, when controlling the fuel cell system stack to adopt the preset ejector mode for loading, it includes: based on a preset instruction sending cycle, sending a rotation instruction to the hydrogen circulation pump; obtaining the real-time speed of the hydrogen circulation pump, if the real-time speed is less than the preset speed and the second duration of the real-time speed being less than the preset speed is greater than the preset duration, then continuously controlling the fuel cell system stack to adopt the preset ejector mode for loading.

[0020] Through the above technical solution, the present application periodically sends rotation instructions to the hydrogen circulation pump to detect whether the hydrogen circulation pump has broken the ice. When the hydrogen circulation pump cannot operate normally, the ejector continues to be used for loading. In this way, the normal operation of the hydrogen circulation pump in a low temperature environment can be ensured, the cold start of the fuel cell system can be successfully guaranteed, and the failure rate of the system can be reduced.

[0021] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, after controlling the fuel cell system's stack to adopt the preset ejector mode for loading, it also includes: obtaining the current water temperature of the stack; if the current water temperature is greater than the preset water temperature, it is determined that the cold start of the fuel cell system is completed.

[0022] Through the above technical scheme, the present application provides conditions for judging the success of cold start of the fuel cell system, namely judging whether the water temperature of the fuel cell stack is greater than the preset water temperature. Thus, the present application can ensure the successful ice breaking of the hydrogen circulation pump, thereby ensuring the successful cold start of the fuel cell system under all working conditions.

[0023] In a second aspect, a cold start device for a fuel cell system is provided, the device comprising:

[0024] An acquisition module is used to acquire the current speed of the hydrogen circulation pump and the current ambient temperature;

[0025] a determination module, configured to determine, when the current speed is less than a preset speed and a first duration of time during which the current speed is less than the preset speed is greater than a preset duration, a target heating temperature for heating the coolant with the shortest time according to the current ambient temperature, determine, according to the target heating temperature, an optimal hydrogen pressure interval for a fuel cell system stack without a single low phenomenon, and determine, according to the target heating temperature and the optimal hydrogen pressure interval, a target valve opening and closing frequency with the shortest valve opening and closing frequency; and

[0026] A control module is used to heat the coolant according to the target heating temperature, and after the cooling temperature reaches the target heating temperature, control the fuel cell system stack to adopt a preset ejector mode for loading, and adjust the valve frequency according to the target valve opening and closing frequency until the current speed of the hydrogen circulation pump is greater than or equal to the preset speed.

[0027] In combination with the second aspect, in some possible implementations, the determination module is specifically used to: determine a first target calibration table from a plurality of preset heating time calibration tables based on the current ambient temperature, wherein the first target calibration table includes a plurality of heating temperatures and a heating time for heating the coolant to each heating temperature; and use the heating temperature corresponding to the shortest heating time in the first target calibration table as the target heating temperature.

[0028] In combination with the second aspect and the foregoing implementation manner, in some possible implementation manners, before determining the first target calibration table from the preset multiple heating time calibration tables based on the current ambient temperature, the determination module is further used to:

[0029] Determine multiple ambient temperature intervals to be calibrated and multiple heating temperatures; based on each ambient temperature interval to be calibrated, record the heating time for heating the coolant to each heating temperature under the multiple heating temperatures; obtain the preset multiple heating time calibration tables according to the multiple ambient temperature intervals to be calibrated, the multiple heating temperatures and the heating time for heating the coolant to each heating temperature.

[0030] In combination with the second aspect and the foregoing implementation manner, in some possible implementation manners, the determining module is further used to:

[0031] Based on the target heating temperature, at least one target hydrogen pressure interval is determined when the fuel cell system's stack does not have a single low phenomenon, wherein there is no intersection between the at least one target hydrogen pressure interval; the minimum hydrogen pressure in the at least one target hydrogen pressure interval is determined, and the target hydrogen pressure interval corresponding to the minimum hydrogen pressure is used as the optimal hydrogen pressure interval; based on the target heating temperature and the optimal hydrogen pressure interval, a second target calibration table is determined from a plurality of preset stack single low calibration tables, wherein the second target calibration table includes a calibrated hydrogen pressure interval and at least one group of valve opening and closing frequencies corresponding to the calibrated hydrogen pressure interval; a group of valve opening and closing frequencies in the second target calibration table in which the fuel cell system's stack does not have a single low phenomenon and in which the valve opening and closing frequency is the shortest is used as the target valve opening and closing frequency.

[0032] In combination with the second aspect and the above implementation, in some possible implementations, before determining the second target calibration table from the preset multiple stack single low calibration tables based on the target heating temperature and the optimal hydrogen pressure range, the determination module is further used to:

[0033] Determine multiple hydrogen pressure intervals; under each of the ambient temperature intervals to be calibrated, based on each heating temperature, record whether the single low phenomenon occurs in the fuel cell stack under each set of valve opening and closing frequencies corresponding to each hydrogen pressure interval; obtain the preset multiple fuel cell stack single low calibration tables according to whether the single low phenomenon occurs in the fuel cell stack under the multiple heating temperatures, the multiple hydrogen pressure intervals and each set of valve opening and closing frequencies corresponding to each hydrogen pressure interval.

[0034] In combination with the second aspect and the above implementation, in some possible implementations, when controlling the stack of the fuel cell system to use the preset ejector mode to load, the control module is specifically used to:

[0035] Based on a preset instruction sending cycle, a rotation instruction is sent to the hydrogen circulation pump; the real-time rotation speed of the hydrogen circulation pump is obtained, and if the real-time rotation speed is less than the preset rotation speed and the second duration for which the real-time rotation speed is less than the preset rotation speed is greater than the preset duration, the fuel cell system stack is continuously controlled to adopt the preset ejector mode for loading.

[0036] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, after controlling the fuel cell system's stack to adopt the preset ejector mode for loading, the control module is also used to: obtain the current water temperature of the stack; and when the current water temperature is greater than the preset water temperature, determine that the cold start of the fuel cell system is completed.

[0037] In a third aspect, a fuel cell system is provided, comprising the cold start device of the fuel cell system as described above.

[0038] In a fourth aspect, a vehicle is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the cold start method of the fuel cell system as described in the above embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the principle of a solution provided by an embodiment of the present application;

[0040] Figure 2 is a flow chart of a cold start method for a fuel cell system provided in an embodiment of the present application;

[0041] Figure 3 is a schematic diagram of a cold start device for a fuel cell system provided in an embodiment of the present application;

[0042] Figure 4 It is a schematic diagram of the structure of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0043] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0044] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0045] Those skilled in the art will understand that low-temperature starting performance is a very important indicator for a fuel cell system. Due to the limitations of system architecture and product performance, when the system is cold-started at low temperatures, the hydrogen circulation pump may freeze and fail to start, resulting in limited use of the hydrogen circulation pump and even system failure requiring repair.

[0046] In the face of the problem of hydrogen circulation pump freezing in low temperature environment, the relevant technology chooses to increase the torque to achieve the purpose of de-icing by low frequency and high current, so as to start the fuel cell system. However, the current value required to break the ice of the hydrogen circulation pump is difficult to control. If the current is too large, it may cause damage to the circuit board. If the current is too small, it may not be possible to start the fuel cell system normally in a low temperature environment. Therefore, this solution has poor stability and potential safety hazards.

[0047] Therefore, the present application proposes a cold start method for a fuel cell system, which can effectively avoid the problem of hydrogen pump freezing after the fuel cell system is cold started, ensure the successful cold start of the system under all working conditions and the efficiency and life requirements of the system.

[0048] Before explaining the cold start method of the fuel cell system provided in the embodiment of the present application, the principle of the scheme involved in the embodiment of the present application is first explained.

[0049] Figure 1 This is a schematic diagram of the principle of a solution of an embodiment of the present application, such as Figure 1 As shown, the cold start method of the fuel cell system of the present application involves the following components: an electric heater 1, a cooling water pump 2, a fuel cell stack 3, a gas-liquid separator 4, a hydrogen circulation pump 5, a drain valve 6, a nitrogen exhaust valve 7, an ejector 8, a hydrogen injection valve 9 and a hydrogen heat exchanger 10.

[0050] Among them, the electric heater 1 is used to heat the coolant, the cooling water pump 2 is used to circulate the coolant to cool the fuel cell stack, the gas-liquid separator 4 is used for gas-liquid separation, the hydrogen circulation pump 5 is used to circulate hydrogen, the drain valve 6 is used for draining water, the nitrogen exhaust valve 7 is used for draining nitrogen and water, the ejector 8 is used to eject hydrogen, and the hydrogen heat exchanger 10 heats the hydrogen through the coolant.

[0051] It can be understood that the present application takes into account that the hydrogen circulation pump 5 cannot be used normally in a low-temperature environment, but some hydrogen will flow out. Therefore, in order to start the fuel cell system faster, the embodiment of the present application can set an ejector 8 in the hydrogen circulation loop. In the preset ejector mode, the ejector 8 can use a high-speed and high-energy flow (such as liquid, gas or other material flow) to eject a low-speed and low-energy hydrogen flow in a low-temperature environment. The ejection flow in the ejector 8 transfers energy to the hydrogen flow, thereby promoting hydrogen circulation in a low-temperature environment.

[0052] Specifically, Figure 1As shown, when the ambient temperature is too low, the hydrogen circulation pump 5 cannot be used normally. At this time, the hydrogen in the entire fuel cell system needs to be pulled by the ejector 5 in a certain amount, and the drain valve 6 and the nitrogen exhaust valve 7 are controlled according to the calibrated valve opening and closing frequency to start the fuel cell system. At the same time, the coolant is heated by the electric heater 1 at a certain temperature until the water temperature of the battery stack reaches the preset temperature value, indicating that the fuel cell system is successfully cold-started. When the fuel cell system is successfully started and the hydrogen circulation pump 5 can work normally, the embodiment of the present application can use the hydrogen circulation pump 5 alone, or it can be used in combination with the ejector 8 and the hydrogen circulation pump 5. Specifically, it can be selected by those skilled in the art according to the actual situation. The following examples are listed in combination with the accompanying drawings to elaborate on the cold start method of the fuel cell system of the present application.

[0053] Figure 2 This is a flow chart of a cold start method for a fuel cell system provided in an embodiment of the present application.

[0054] For example, Figure 2 As shown, the method comprises the following steps:

[0055] In step S201, the current rotation speed of the hydrogen circulation pump and the current ambient temperature are obtained.

[0056] Among them, the current rotation speed of the hydrogen circulation pump and the current ambient temperature can be obtained through corresponding sensors respectively.

[0057] It is understandable that if the speed of the hydrogen circulation pump cannot reach the set value within a certain period of time, it is determined that the hydrogen circulation pump is frozen. Therefore, the embodiment of the present application needs to obtain the current speed of the hydrogen circulation pump and the duration of the current speed being less than the preset speed, thereby determining whether to implement the cold start strategy of the fuel cell system. Furthermore, by obtaining the current ambient temperature, the heating temperature of the hydrogen circulation pump is determined so that it can start normally in a low temperature environment.

[0058] In step S202, if the current speed is less than the preset speed and the first duration of the current speed being less than the preset speed is greater than the preset duration, the target heating temperature for the shortest time for heating the coolant is determined according to the current ambient temperature, and the optimal hydrogen pressure range when the fuel cell system stack does not have a single low phenomenon is determined according to the target heating temperature, and the target valve opening and closing frequency with the shortest valve opening and closing frequency is determined according to the target heating temperature and the optimal hydrogen pressure range.

[0059] It should be noted that after obtaining the current speed, the fuel cell system of the embodiment of the present application needs to compare the current speed with the preset speed, and compare the duration that the current speed is less than the preset speed with the preset duration. When the current speed is less than the preset speed and the duration that the current speed is less than the preset speed is greater than the preset duration, that is, when the speed is too low and the process lasts too long, it is determined that the hydrogen circulation pump is frozen at this time, and the cold start strategy of the fuel cell system is implemented.

[0060] Specifically, before the fuel cell system is cold-started, it is first necessary to determine whether the hydrogen circulation pump is frozen. The FCU (Fuel-cell Control Unit) sends a power-on command to the hydrogen circulation pump, and the system receives the hydrogen pump feedback speed. When the hydrogen pump speed cannot reach the set value within a preset time, such as 5s (calibrated amount), the hydrogen circulation pump is determined to be frozen, and the ejector cold start strategy is synchronously started to pull a certain amount of load through the ejector to start the fuel cell system. In addition, the present application does not make specific limitations on the above-mentioned preset time, and those skilled in the art can set it according to actual conditions.

[0061] Furthermore, in order to solve the problem of the hydrogen circulation pump freezing in a low-temperature environment and the inability to start the fuel cell system, the present application requires heating the coolant and adjusting the valve opening and closing frequency. In addition, in order to improve the startup performance of the fuel cell system, the present application takes into account the duration of heating the coolant and the target valve opening and closing frequency.

[0062] Optionally, the present application uses a PTC (Parametric Technology Corporation, electric heater) in a fuel cell system, i.e. Figure 1 The electric heater 1 heats the coolant to a value above the calibration value, and the target temperature of the PTC heating needs to be calibrated according to the current ambient temperature obtained in step S201.

[0063] Therefore, the present application determines whether the hydrogen circulation pump is frozen by the current speed of the hydrogen circulation pump, and then uses the cold start strategy of the fuel cell system to enable it to start normally in a low temperature environment. The following embodiments will give a detailed introduction to the cold start strategy of the fuel cell system of the present application.

[0064] Optionally, in some embodiments, a target heating temperature for heating the coolant in the shortest time is determined based on the current ambient temperature, including: based on the current ambient temperature, determining a first target calibration table from a plurality of preset heating time calibration tables, wherein the first target calibration table includes a plurality of heating temperatures and a heating time for heating the coolant to each heating temperature; and taking the heating temperature corresponding to the shortest heating time in the first target calibration table as the target heating temperature.

[0065] Specifically, the present application provides multiple heating time calibration tables, each heating time calibration table includes multiple coolant heating temperatures and the corresponding heating time at each heating temperature. Therefore, the present application can match the current ambient temperature with multiple heating time calibration tables to obtain a target heating time calibration table, that is, the first target calibration table in the above embodiment, in which the heating temperature corresponding to the shortest heating time to heat the coolant to the target temperature is selected.

[0066] Therefore, the present application fully considers the influence of the current ambient temperature on the startup of the fuel cell system, and obtains the heating temperature of the coolant in a range suitable for the current ambient temperature, and the time is minimized. Furthermore, the present application can heat the coolant in the shortest time, so that the fuel cell system can heat up quickly.

[0067] Optionally, in some embodiments, before determining the first target calibration table from a plurality of preset heating time calibration tables based on the current ambient temperature, it also includes: determining a plurality of ambient temperature intervals to be calibrated and a plurality of heating temperatures; based on each ambient temperature interval to be calibrated, recording the heating time for heating the coolant to each heating temperature at a plurality of heating temperatures; and obtaining a plurality of preset heating time calibration tables according to the plurality of ambient temperature intervals to be calibrated, the plurality of heating temperatures and the heating time for heating the coolant to each heating temperature.

[0068] Specifically, the present application needs to record the heating time corresponding to multiple heating temperatures within the set temperature range, the heater target heating temperature, and the time required for the coolant to be heated to the preset temperature corresponding to each heating temperature under the multiple heating temperatures, and select the heating target temperature with the shortest time required for the coolant to be heated to the preset temperature at each temperature based on the current ambient temperature.

[0069] In some embodiments, since the target temperature of PTC heating needs to be calibrated according to the current ambient temperature, the calibration principle of the present application, that is, the multiple heating time calibration tables in this embodiment are shown in the following multiple tables, among which Table 1 is a heating time calibration table when the ambient temperature T is -30≤T<-20℃, Table 2 is a heating time calibration table when the ambient temperature T is -20≤T<-10℃, and Table 3 is a heating time calibration table when the ambient temperature T is -10≤T<0℃.

[0070] Table 1

[0071]

[0072] Table 2

[0073]

[0074] Table 3

[0075]

[0076] Therefore, the present application calibrates multiple temperature intervals and records multiple PTC heating temperatures and their corresponding hydrogen circulation pump defrosting times in each interval. Therefore, the present application can match the appropriate heating time calibration table according to the current ambient temperature to obtain the target heating temperature with the shortest heating time to heat the coolant to the preset temperature, thereby greatly improving the heating efficiency of the coolant and effectively avoiding the problem of safety hazards caused by excessively high or low temperatures.

[0077] In addition, the preset temperature of the coolant in this embodiment can be above 0°C (not exceeding 80°C), which is not specifically limited here. Those skilled in the art can refer to the data in Tables 1 to 3 above and select the most appropriate PTC heating target temperature based on actual conditions to prevent the hydrogen circulation pump from freezing, thereby ensuring the stability of the cold start of the fuel cell system.

[0078] Optionally, in some embodiments, the optimal hydrogen pressure interval when the fuel cell system's stack does not experience a single low phenomenon is determined according to the target heating temperature, and the target valve opening and closing frequency with the shortest valve opening and closing frequency is determined according to the target heating temperature and the optimal hydrogen pressure interval, including: based on the target heating temperature, determining at least one target hydrogen pressure interval when the fuel cell system's stack does not experience a single low phenomenon, wherein there is no intersection between at least one target hydrogen pressure interval; determining the minimum hydrogen pressure in at least one target hydrogen pressure interval, and taking the target hydrogen pressure interval corresponding to the minimum hydrogen pressure as the optimal hydrogen pressure interval; based on the target heating temperature and the optimal hydrogen pressure interval, determining a second target calibration table from a plurality of preset stack single low calibration tables, wherein the second target calibration table includes a calibrated hydrogen pressure interval and at least one group of valve opening and closing frequencies corresponding to the calibrated hydrogen pressure interval; taking a group of valve opening and closing frequencies in the second target calibration table in which the fuel cell system's stack does not experience a single low phenomenon and which has the shortest valve opening and closing frequency as the target valve opening and closing frequency.

[0079] It is understandable that due to the difference in internal operating conditions between batteries, the voltage of individual single cells will be significantly lower than the average voltage of the stack, which will cause damage to the fuel cell system in the long run and bring unnecessary trouble to users. In order to solve this problem, when obtaining the optimal hydrogen pressure range of the hydrogen circulation pump, the present application fully considers whether the stack of the fuel cell system will have a single low phenomenon. Therefore, the fuel cell system is controlled by the optimal hydrogen pressure range of the embodiment of the present application, which not only enables it to start in a low temperature environment, but also ensures that the performance of the system is not damaged.

[0080] In addition, those skilled in the art will understand that the pressure of hydrogen is related to temperature. At a certain volume, the pressure of hydrogen is proportional to the temperature, that is, when the temperature rises, the pressure of hydrogen will increase. Therefore, the present application takes into account that in a fuel cell system, the pressure and temperature of hydrogen need to be maintained within a certain range, and the two affect each other. Therefore, the present application obtains a mapping relationship between the target heating temperature and the hydrogen pressure range based on the relationship between temperature and hydrogen pressure, and matches the appropriate target hydrogen pressure range according to the target heating temperature.

[0081] Specifically, the present application matches the target heating temperature obtained in step S201 with the hydrogen pressure interval set in the embodiment of the present application, and obtains the target hydrogen pressure interval when the stack of one or more fuel cell systems does not have a single low phenomenon. Since the present application needs to determine a unique hydrogen pressure interval, that is, the optimal hydrogen pressure interval in the present embodiment, the present application compares the matched multiple target hydrogen pressure intervals and takes the interval with the minimum hydrogen pressure as the optimal hydrogen pressure interval.

[0082] Optionally, in some embodiments, before determining the second target calibration table from multiple preset fuel cell stack single low calibration tables based on the target heating temperature and the optimal hydrogen pressure range, it also includes: determining multiple hydrogen pressure ranges; in each ambient temperature range to be calibrated, based on each heating temperature, recording whether the fuel cell stack has a single low phenomenon at each group of valve opening and closing frequencies corresponding to each hydrogen pressure range; and obtaining multiple preset fuel cell stack single low calibration tables based on whether the fuel cell stack has a single low phenomenon at multiple heating temperatures, multiple hydrogen pressure ranges, and each group of valve opening and closing frequencies corresponding to each hydrogen pressure range.

[0083] It should be noted that the present application needs to calibrate the opening frequency of the drain valve 6 and the nitrogen exhaust valve 7 under different hydrogen pressure ranges, and record the state of the fuel cell stack under different ADV (Anode Drain Valve) and APV (Anode Purge Valve), that is, whether the fuel cell stack has a single low phenomenon under the calibrated valve opening frequency. Therefore, the present application can obtain multiple fuel cell stack single low calibration tables.

[0084] In some embodiments, during the cold start process of the fuel cell system, multiple stack single low calibration tables can be shown in the following table: Table 4 is the stack single low calibration table when the hydrogen pressure P is 120≤P<140Kpa, Table 5 is the stack single low calibration table when the hydrogen pressure P is 140≤P<160Kpa, and Table 6 is the stack single low calibration table when the hydrogen pressure P is 160≤P<180Kpa.

[0085] Table 4

[0086]

[0087] Table 5

[0088]

[0089] Table 6

[0090]

[0091] Based on the above embodiments, it can be understood that the cold start effects of the fuel cell stack with different hydrogen inlet pressures and different valve opening and closing frequencies are different. The fact that the fuel cell stack does not experience a single low proves that the hydrogen pressure and valve frequency at this point meet the requirements. Therefore, the operating condition with the lowest hydrogen pressure and the shortest valve opening and closing frequency is selected as the optimal operating condition.

[0092] Preferably, the hydrogen pressure can be set to 140 KPa, and a suitable hydrogen pressure range is matched according to the hydrogen pressure value to determine the second target calibration table to calibrate the opening frequency of the drain valve 6 and the nitrogen exhaust valve 7.

[0093] For example, in this embodiment, the current ambient temperature T is -20°C, which is in the temperature range of -20≤T<-10°C, and the target heating temperature is -10°C. The heating time of the hydrogen circulation pump is 100s. According to the mapping relationship between the target heating temperature and the hydrogen pressure, the present application can obtain that at the target heating temperature, the suitable hydrogen pressure ranges are 120≤P<140Kpa and 140≤P<160Kpa, and it can be known that the minimum hydrogen pressure is 120Kpa. Therefore, at the current ambient temperature, the optimal hydrogen pressure range of the hydrogen circulation pump is 120≤P<140Kpa. Furthermore, referring to Table 4, under this hydrogen pressure range, the present application selects the ADV opening and closing frequency of 1s on and 3s off, which does not cause the single low phenomenon, and the APV opening and closing frequency is 1s off and 3s off.

[0094] In step S203, the coolant is heated according to the target heating temperature, and after the cooling temperature reaches the target heating temperature, the fuel cell system stack is controlled to use a preset ejector mode for loading, and the valve frequency is adjusted according to the target valve opening and closing frequency until the current speed of the hydrogen circulation pump is greater than or equal to the preset speed.

[0095] Specifically, through step S202, the present application determines the target heating temperature for heating the coolant in the fuel cell system to a preset temperature and in the shortest time based on the current ambient temperature, as well as the minimum hydrogen pressure when the fuel cell system's stack does not have a single low phenomenon and the target valve opening and closing frequency corresponding to the minimum hydrogen pressure. Thus, the present application can heat the coolant according to the PTC target heating temperature to a temperature at which it can operate.

[0096] Specifically, Figure 1As shown, when the fuel cell system adopts the ejector mode for cold start, the coolant is heated according to the target heating temperature, the ejector 8 injects hydrogen into the fuel cell stack, the fuel cell stack is loaded with a calibrated amount, and the minimum pressure obtained in the above embodiment is used to adjust the frequency of the drain valve 6 and the nitrogen exhaust valve 7 according to the target valve opening and closing frequency to provide hydrogen to the fuel cell system, realize the hydrogen circulation loop, and finally realize the cold start of the fuel cell system.

[0097] In addition, preferably, the calibration amount of the load of the fuel cell stack in the ejector mode can be 50A, which is not specifically limited here.

[0098] Therefore, the present application combines a hydrogen circulation pump and an ejector to meet the hydrogen circulation requirements of the fuel cell system, effectively circulate the gas, enable a sufficient amount of hydrogen to circulate in the fuel cell system, increase the power of the hydrogen circulation loop, and further improve the cold start efficiency of the fuel cell system.

[0099] Optionally, in some embodiments, when controlling the fuel cell system's stack to adopt a preset ejector mode for loading, it includes: based on a preset instruction sending cycle, sending a rotation instruction to the hydrogen circulation pump; obtaining the real-time speed of the hydrogen circulation pump, if the real-time speed is less than the preset speed and the second duration of the real-time speed being less than the preset speed is greater than the preset duration, then continuously controlling the fuel cell system's stack to adopt the preset ejector mode for loading.

[0100] It should be noted that during the normal loading process of the fuel cell stack, the present application needs to monitor the status of the hydrogen circulation pump in real time. If the hydrogen circulation pump is not operating normally, the fuel cell stack continues to use the ejector mode for loading until the water temperature of the fuel cell stack reaches the normal operating temperature, and the cold start is determined to be successful.

[0101] Specifically, in this embodiment, the preset instruction sending cycle can be 10s, and the calibration value of the stack water temperature is above 60°C, which is not specifically limited here. During the normal loading process of the stack, a rotation instruction is sent to the hydrogen circulation pump every 10s to detect whether the hydrogen circulation pump has broken the ice and returned to normal: if the hydrogen circulation pump cannot operate normally, the stack continues to use the ejector mode for loading; if the hydrogen circulation pump resumes operation, the FCU sends an instruction to the fuel cell system to jump to the hydrogen circulation pump mode operation state.

[0102] Optionally, in some embodiments, after controlling the fuel cell system's stack to use a preset ejector mode for loading, it also includes: obtaining the current water temperature of the stack; if the current water temperature is greater than the preset water temperature, determining that the cold start of the fuel cell system is completed.

[0103] Specifically, in order to ensure the success of the cold start of the fuel cell system, the present application provides the conditions for judging the success of the cold start of the fuel cell system. When the current water temperature of the stack is greater than the preset water temperature, the system is judged to have successfully started cold. In other words, during the cold start of the system, whether the ejector is used for loading or the cooling water temperature of the hydrogen circulation pump is heated, when the stack water temperature reaches above 60°C, the cold start is judged to be successful and the system can load normally.

[0104] In summary, the cold start method of the fuel cell system of the present application, when the current speed of the hydrogen circulation pump is less than the preset speed and the duration of the current speed being less than the preset speed is greater than the preset duration, determines the target heating temperature for heating the coolant to the preset temperature and the shortest time according to the temperature range of the current ambient temperature, and determines the minimum hydrogen pressure and the corresponding target valve opening and closing frequency when the stack does not have a single low phenomenon. After the coolant is heated to the preset temperature according to the target heating temperature, the stack is controlled to use the preset ejector mode for loading, and based on the minimum hydrogen pressure, the valve frequency is adjusted according to the target valve opening and closing frequency to provide hydrogen to the system until the stack temperature reaches the preset temperature value. In this way, the problem of hydrogen pump icing after the cold start of the fuel cell system is effectively avoided, and the successful cold start of the system under all working conditions and the efficiency and life requirements of the system are ensured.

[0105] Figure 3 It is a structural schematic diagram of a cold start device for a fuel cell system provided in an embodiment of the present application.

[0106] For example, Figure 3 As shown, the cold start device 10 of the fuel cell system may include an acquisition module 100 , a determination module 200 and a control module 300 .

[0107] Among them, the acquisition module 100 is used to obtain the current speed and current ambient temperature of the hydrogen circulation pump; the determination module 200 is used to determine the target heating temperature for heating the coolant with the shortest time according to the current ambient temperature when the current speed is less than the preset speed and the first continuous time of the current speed being less than the preset speed is greater than the preset time, and determine the optimal hydrogen pressure range when the fuel cell system stack does not have a single low phenomenon according to the target heating temperature, and determine the target valve opening and closing frequency with the shortest valve opening and closing frequency according to the target heating temperature and the optimal hydrogen pressure range; the control module 300 is used to heat the coolant according to the target heating temperature, and after the cooling temperature reaches the target heating temperature, control the fuel cell system stack to use a preset ejector mode for loading, and adjust the valve frequency according to the target valve opening and closing frequency until the current speed of the hydrogen circulation pump is greater than or equal to the preset speed.

[0108] Optionally, in some embodiments, the determination module 200 is specifically used to: determine a first target calibration table from a plurality of preset heating time calibration tables based on the current ambient temperature, wherein the first target calibration table includes a plurality of heating temperatures and a heating time for heating the coolant to each heating temperature; and take the heating temperature corresponding to the shortest heating time in the first target calibration table as the target heating temperature.

[0109] Optionally, in some embodiments, before determining the first target calibration table from a plurality of preset heating time calibration tables based on the current ambient temperature, the determination module 200 is further used to: determine a plurality of ambient temperature intervals to be calibrated and a plurality of heating temperatures; based on each ambient temperature interval to be calibrated, record the heating time for heating the coolant to each heating temperature at a plurality of heating temperatures; and obtain a plurality of preset heating time calibration tables according to the plurality of ambient temperature intervals to be calibrated, the plurality of heating temperatures and the heating time for heating the coolant to each heating temperature.

[0110] Optionally, in some embodiments, based on the current ambient temperature, the determination module 200 is also used to: determine, based on the target heating temperature, at least one target hydrogen pressure interval when the fuel cell system's stack does not have a single low phenomenon, wherein there is no intersection between at least one target hydrogen pressure interval; determine the minimum hydrogen pressure in at least one target hydrogen pressure interval, and use the target hydrogen pressure interval corresponding to the minimum hydrogen pressure as the optimal hydrogen pressure interval; based on the target heating temperature and the optimal hydrogen pressure interval, determine a second target calibration table from a plurality of preset stack single low calibration tables, wherein the second target calibration table includes a calibrated hydrogen pressure interval and at least one set of valve opening and closing frequencies corresponding to the calibrated hydrogen pressure interval; use a set of valve opening and closing frequencies in the second target calibration table in which the fuel cell system's stack does not have a single low phenomenon and has the shortest valve opening and closing frequency as the target valve opening and closing frequency.

[0111] Optionally, in some embodiments, before determining the second target calibration table from multiple preset stack single-low calibration tables based on the target heating temperature and the optimal hydrogen pressure range, the determination module 200 is also used to: determine multiple hydrogen pressure ranges; in each ambient temperature range to be calibrated, based on each heating temperature, record whether the stack has a single-low phenomenon at each set of valve opening and closing frequencies corresponding to each hydrogen pressure range; obtain multiple preset stack single-low calibration tables based on whether the stack has a single-low phenomenon at multiple heating temperatures, multiple hydrogen pressure ranges and each set of valve opening and closing frequencies corresponding to each hydrogen pressure range.

[0112] Optionally, in some embodiments, when controlling the stack of the fuel cell system to adopt a preset ejector mode for loading, the control module 300 is specifically used to: send a rotation instruction to the hydrogen circulation pump based on a preset instruction sending cycle; obtain the real-time speed of the hydrogen circulation pump, if the real-time speed is less than the preset speed and the second duration that the real-time speed is less than the preset speed is greater than the preset duration, then continuously control the stack of the fuel cell system to adopt the preset ejector mode for loading.

[0113] Optionally, in some embodiments, after controlling the fuel cell system's stack to adopt a preset ejector mode for loading, the control module 300 is further used to: obtain the current water temperature of the stack; and when the current water temperature is greater than the preset water temperature, determine that the cold start of the fuel cell system is completed.

[0114] It should be noted that the above explanation of the cold start method embodiment of the fuel cell system is also applicable to the cold start device of the fuel cell system of this embodiment, which will not be repeated here.

[0115] In the case of an integrated unit, the device may include a processing module and a storage module. When the device is applied to a car, the processing module may be used to control and manage the actions of the car. The storage module may be used to support the car to execute mutual program codes, etc.

[0116] The processing module may be a processor or a controller, which may implement or execute various exemplary logic blocks, modules and circuits disclosed in the present application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory.

[0117] In summary, the cold start device of the fuel cell system of the present application, when the current speed of the hydrogen circulation pump is less than the preset speed and the duration of the current speed being less than the preset speed is greater than the preset duration, determines the target heating temperature for heating the coolant to the preset temperature and the shortest time according to the temperature range of the current ambient temperature, and determines the minimum hydrogen pressure and the corresponding target valve opening and closing frequency when the stack does not have a single low phenomenon. After heating the coolant to the preset temperature according to the target heating temperature, the stack is controlled to use the preset ejector mode for loading, and based on the minimum hydrogen pressure, the valve frequency is adjusted according to the target valve opening and closing frequency to provide hydrogen to the system until the stack temperature reaches the preset temperature value. In this way, the problem of hydrogen pump icing after the cold start of the fuel cell system is effectively avoided, and the successful cold start of the system under all working conditions and the efficiency and life requirements of the system are ensured.

[0118] The embodiment of the present application also provides a fuel cell system, which includes the cold start device of the fuel cell system as described above. The fuel cell system of the present application can effectively avoid the problem of hydrogen pump freezing after the cold start of the fuel cell system, and ensure the successful cold start of the system under all working conditions and the efficiency and life requirements of the system.

[0119] The embodiment of the present application also provides a vehicle, Figure 4 is a schematic diagram of the structure of a vehicle provided in an embodiment of the present application, such as Figure 4 As shown, the vehicle may include a memory and a processor, wherein the memory stores executable program code, and the processor is used to call and execute the executable program code to perform the cold start method of the fuel cell system provided in the embodiment of the present application.

[0120] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0121] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0122] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A cold start method for a fuel cell system, characterized in that: The following steps are involved: Get the current speed and current ambient temperature of the hydrogen circulation pump; If the current speed is less than the preset speed and the first duration of the current speed being less than the preset speed is greater than the preset duration, a target heating temperature for heating the coolant with the shortest time is determined according to the current ambient temperature, and an optimal hydrogen pressure interval when the fuel cell stack of the fuel cell system does not have a single low phenomenon is determined according to the target heating temperature, and a target valve opening and closing frequency with the shortest valve opening and closing frequency is determined according to the target heating temperature and the optimal hydrogen pressure interval; and The coolant is heated according to the target heating temperature, and after the cooling temperature reaches the target heating temperature, the fuel cell system stack is controlled to adopt a preset ejector mode for loading, and the valve frequency is adjusted according to the target valve opening and closing frequency until the current speed of the hydrogen circulation pump is greater than or equal to the preset speed.

2. The method according to claim 1, characterized in that The step of determining the target heating temperature with the shortest time required to heat the coolant according to the current ambient temperature includes: Based on the current ambient temperature, determining a first target calibration table from a plurality of preset heating time calibration tables, wherein the first target calibration table includes a plurality of heating temperatures and a heating time for heating the coolant to each heating temperature; The heating temperature corresponding to the shortest heating time in the first target calibration table is used as the target heating temperature.

3. The method according to claim 2, characterized in that Before determining the first target calibration table from the preset multiple heating time calibration tables based on the current ambient temperature, the method further includes: Determine multiple ambient temperature intervals to be calibrated and multiple heating temperatures; Based on each ambient temperature interval to be calibrated, recording the heating time for heating the coolant to each heating temperature at the multiple heating temperatures; The preset multiple heating time calibration tables are obtained according to the multiple ambient temperature intervals to be calibrated, the multiple heating temperatures and the heating time for heating the coolant to each heating temperature.

4. The method according to claim 1, characterized in that The method of determining the optimal hydrogen pressure interval when the fuel cell stack of the fuel cell system does not have a single low phenomenon according to the target heating temperature, and determining the target valve opening and closing frequency with the shortest valve opening and closing frequency according to the target heating temperature and the optimal hydrogen pressure interval, includes: Based on the target heating temperature, determining at least one target hydrogen pressure interval when the fuel cell stack of the fuel cell system does not have a single low phenomenon, wherein there is no intersection between the at least one target hydrogen pressure interval; Determining a minimum hydrogen pressure in the at least one target hydrogen pressure interval, and using the target hydrogen pressure interval corresponding to the minimum hydrogen pressure as the optimal hydrogen pressure interval; Based on the target heating temperature and the optimal hydrogen pressure range, a second target calibration table is determined from a plurality of preset fuel cell stack single low calibration tables, wherein the second target calibration table includes a calibrated hydrogen pressure range and at least one set of valve opening and closing frequencies corresponding to the calibrated hydrogen pressure range; A group of valve opening and closing frequencies in which the fuel cell stack of the fuel cell system does not have a single low phenomenon and the valve opening and closing frequency is the shortest in the second target calibration table is used as the target valve opening and closing frequency.

5. The method according to claim 4, characterized in that Before determining the second target calibration table from the preset plurality of stack single low calibration tables based on the target heating temperature and the optimal hydrogen pressure range, the method further includes: Determining multiple hydrogen pressure intervals; In each ambient temperature range to be calibrated, based on each heating temperature, record whether the single low phenomenon occurs in the stack under each valve opening and closing frequency corresponding to each hydrogen pressure range; The preset multiple fuel cell stack single low calibration tables are obtained based on the multiple heating temperatures, the multiple hydrogen pressure intervals and whether the single low phenomenon occurs in the fuel cell stack under each group of valve opening and closing frequencies corresponding to each hydrogen pressure interval.

6. The method according to claim 1, characterized in that When controlling the fuel cell system stack to adopt the preset ejector mode to load, it includes: Based on a preset instruction sending cycle, sending a rotation instruction to the hydrogen circulation pump; The real-time rotation speed of the hydrogen circulation pump is obtained. If the real-time rotation speed is less than the preset rotation speed and the second duration of the real-time rotation speed being less than the preset rotation speed is greater than the preset duration, the fuel cell system stack is continuously controlled to adopt the preset ejector mode for loading.

7. The method according to claim 1 or 6, characterized in that: After controlling the fuel cell system stack to adopt the preset ejector mode to load, the method further includes: Obtaining the current water temperature of the battery stack; If the current water temperature is greater than the preset water temperature, it is determined that the cold start of the fuel cell system is completed.

8. A cold start device for a fuel cell system, characterized in that: include: An acquisition module is used to acquire the current speed of the hydrogen circulation pump and the current ambient temperature; a determination module, which determines a target heating temperature for heating the coolant in the shortest time according to the current ambient temperature when the current speed is less than a preset speed and a first duration during which the current speed is less than the preset speed is greater than a preset duration, and determines an optimal hydrogen pressure interval when the fuel cell system stack does not have a single low phenomenon according to the target heating temperature, and determines a target valve opening and closing frequency with the shortest valve opening and closing frequency according to the target heating temperature and the optimal hydrogen pressure interval; and A control module is used to heat the coolant according to the target heating temperature, and after the cooling temperature reaches the target heating temperature, control the fuel cell system stack to adopt a preset ejector mode for loading, and adjust the valve frequency according to the target valve opening and closing frequency until the current speed of the hydrogen circulation pump is greater than or equal to the preset speed.

9. A fuel cell system, characterized in that: include: The cold starting device of the fuel cell system as claimed in claim 8.

10. A vehicle, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the cold start method for the fuel cell system according to any one of claims 1 to 7.

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