Methods, apparatus, vehicles, and storage media for calculating the starting current of fuel cell stacks.

Abstract

This application relates to the field of vehicle technology, and in particular to a method, apparatus, vehicle, and storage medium for calculating the starting current of a fuel cell stack. The method includes: acquiring the current temperature and target temperature of the coolant outlet; determining the total heat requirement for low-temperature startup based on the current and target temperatures, and acquiring the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane; and calculating the startup current of the fuel cell stack based on the total heat requirement, the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane. This solves the problems of related technologies failing to couple the total heat requirement for low-temperature startup of the fuel cell stack and neglecting the impact of fuel cell stack water production on startup, leading to low-temperature startup failure or excessively long low-temperature startup times. It ensures that the heat generated by the fuel cell is sufficient to suppress the freezing rate and rapidly raise the fuel cell stack temperature above the freezing point of the reaction water, thus shortening the low-temperature startup time.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a method, apparatus, vehicle, and storage medium for calculating the starting current of a fuel cell stack. Background Technology

[0002] Fuel cells generate electricity, water, and heat through an electrochemical reaction between hydrogen and oxygen. Water, a product of this electrochemical reaction, serves both as the medium for proton transfer during power generation and as a major obstacle to hydrogen and oxygen gas transport. When a fuel cell starts at or below freezing, the water product freezes, hindering the reaction gases from reaching the catalyst surface for further electrochemical reactions. If the freezing completely obstructs the gas reaction pathways, it leads to low-temperature start-up failure. Furthermore, freezing damages the fuel cell membrane electrode assembly (MEA), shortening the fuel cell's lifespan. Therefore, to ensure successful low-temperature start-up, precise monitoring of the start-up temperature is crucial. This ensures the heat generated by the fuel cell is sufficient to suppress the freezing rate and rapidly raise the stack temperature above the freezing point of the reaction water, thus shortening the low-temperature start-up time.

[0003] Related technologies typically employ methods such as PTC-assisted heating or self-generated heat from the fuel cell stack for low-temperature cold start-up. However, these technologies fail to couple the total heat demand for low-temperature start-up of the fuel cell stack and do not consider the impact of water production on the start-up process, leading to either low-temperature start-up failure or excessively long start-up times. Summary of the Invention

[0004] This application provides a method, apparatus, vehicle, and storage medium for calculating the start-up current of a fuel cell stack, in order to solve the problems of related technologies failing to couple the total heat demand for low-temperature start-up of the fuel cell stack and failing to consider the impact of fuel cell stack water production on start-up, resulting in low-temperature start-up failure or excessively long low-temperature start-up time. It can make the heat generated by the fuel cell sufficient to suppress the freezing rate and rapidly increase the temperature of the fuel cell stack away from the freezing point of the reaction water, thereby shortening the low-temperature start-up time.

[0005] The first aspect of this application provides a method for calculating the starting current of an electric fuel cell stack, comprising the following steps:

[0006] Obtain the current temperature and target temperature of the coolant outlet;

[0007] The total heat required for low-temperature startup is determined based on the current temperature and the target temperature, and the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane are obtained.

[0008] The startup current of the fuel cell stack is calculated based on the total heat demand, the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane.

[0009] Optionally, in some embodiments, before calculating the startup current of the fuel cell based on the total required heat, the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane, the following method is further included:

[0010] Obtain the current high-frequency impedance of the fuel cell stack;

[0011] Based on a preset high-frequency impedance-membrane electrode residual water content mapping relationship, the membrane electrode residual water content of the fuel cell stack is determined according to the current high-frequency impedance, and based on a preset high-frequency impedance-maximum freezing water content mapping relationship, the maximum freezing water content of the fuel cell stack is determined according to the current high-frequency impedance.

[0012] The maximum water content of the proton exchange membrane is determined based on the difference between the maximum freezing water content and the remaining water content of the membrane electrode.

[0013] Optionally, in some embodiments, the maximum water content of the proton exchange membrane is:

[0014]

[0015] in, λm is the maximum water content of the proton exchange membrane, β is the water content coefficient of the proton exchange membrane, t0 is the time corresponding to the current temperature at the coolant outlet, t is the time corresponding to the target temperature, and N is the number of solar cells. Let I be the molar mass of water, I be the starting current of the fuel cell stack, and F be the Faraday constant.

[0016] Optionally, in some embodiments, the heat generated by the PTC heater is:

[0017] Q ptc =P v *(t-t0);

[0018] Among them, Q ptc P is the heat output of the PTC heater. v t is the heating power of the PTC heater, t0 is the time corresponding to the current temperature of the coolant outlet, and t is the time corresponding to the target temperature.

[0019] Optionally, in some embodiments, after obtaining the current temperature and target temperature of the coolant outlet, the method further includes:

[0020] The ambient temperature at the current location of the vehicle, the initial temperature of the coolant outlet, and the heating time from the initial temperature to the current temperature are obtained.

[0021] If the initial temperature is greater than the ambient temperature, the temperature rise rate of the coolant outlet is determined based on the initial temperature, the current temperature, and the heating duration; otherwise, the temperature rise rate of the coolant outlet is determined based on the ambient temperature, the current temperature, and the heating duration.

[0022] The heating power of the PTC heater is determined based on the temperature rise rate at the coolant outlet, so as to obtain the heat generation of the PTC heater based on the heating power of the PTC heater.

[0023] Optionally, in some embodiments, the heat generation of the fuel cell stack is:

[0024]

[0025] Among them, Q stack The heat generated by the fuel cell stack is given by N, the number of cells is given by V0, the stack voltage is given when the current power of the fuel cell system reaches the idle power, and I is given the starting current of the fuel cell stack.

[0026] Optionally, in some embodiments, the total required heat is:

[0027] Q 需 =C P *m 总 *(T2-T1);

[0028] Among them, Q 需 For the total required heat, C P For the total specific heat capacity of the fuel cell stack and small circulation components, m 总 T1 represents the total mass of the fuel cell stack and small cycle components, T2 represents the target temperature, and T1 represents the current temperature.

[0029] A second aspect of this application provides a device for calculating the starting current of an electric stack, comprising:

[0030] The first acquisition module is used to acquire the current temperature and target temperature of the coolant outlet;

[0031] The second acquisition module is used to determine the total heat required for low-temperature start-up based on the current temperature and the target temperature, and to acquire the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane.

[0032] The calculation module is used to calculate the start-up current of the fuel cell stack based on the total heat demand, the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane.

[0033] Optionally, in some embodiments, before calculating the startup current of the fuel cell based on the total required heat, the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane, the calculation module further includes:

[0034] The first acquisition unit is used to acquire the current high-frequency impedance of the fuel cell stack;

[0035] The first determining unit is used to determine the membrane electrode remaining water content of the fuel cell stack based on the current high-frequency impedance according to the preset high-frequency impedance-membrane electrode remaining water content mapping relationship, and to determine the maximum freezing water content of the fuel cell stack based on the current high-frequency impedance according to the preset high-frequency impedance-maximum freezing water content mapping relationship.

[0036] The second determining unit is used to determine the maximum water content of the proton exchange membrane based on the difference between the maximum freezing water content and the remaining water content of the membrane electrode.

[0037] Optionally, in some embodiments, the maximum water content of the proton exchange membrane is:

[0038]

[0039] in, λm is the maximum water content of the proton exchange membrane, β is the water content coefficient of the proton exchange membrane, t0 is the time corresponding to the current temperature at the coolant outlet, t is the time corresponding to the target temperature, and N is the number of solar cells. Let I be the molar mass of water, I be the starting current of the fuel cell stack, and F be the Faraday constant.

[0040] Optionally, in some embodiments, the heat generated by the PTC heater is:

[0041] Q ptc =P v *(t-t0);

[0042] Among them, Q ptc P is the heat output of the PTC heater. v t is the heating power of the PTC heater, t0 is the time corresponding to the current temperature of the coolant outlet, and t is the time corresponding to the target temperature.

[0043] Optionally, in some embodiments, after obtaining the current temperature and target temperature of the coolant outlet, the first obtaining module further includes:

[0044] The second acquisition unit is used to acquire the ambient temperature of the current vehicle location, the initial temperature of the coolant outlet, and the heating time from the initial temperature to the current temperature;

[0045] The third determining unit is configured to determine the temperature rise rate of the coolant outlet based on the initial temperature, the current temperature, and the heating duration if the initial temperature is greater than the ambient temperature; otherwise, determine the temperature rise rate of the coolant outlet based on the ambient temperature, the current temperature, and the heating duration.

[0046] The generation unit is used to determine the heating power of the PTC heater based on the temperature rise rate of the coolant outlet, so as to obtain the heat generation of the PTC heater based on the heating power of the PTC heater.

[0047] Optionally, in some embodiments, the heat generation of the fuel cell stack is:

[0048]

[0049] Among them, Q stack The heat generated by the fuel cell stack is given by N, the number of cells is given by V0, the stack voltage is given when the current power of the fuel cell system reaches the idle power, and I is given the starting current of the fuel cell stack.

[0050] Optionally, in some embodiments, the total required heat is:

[0051] Q 需 =C P *m 总 *(T2-T1);

[0052] Among them, Q 需 For the total required heat, C P For the total specific heat capacity of the fuel cell stack and small circulation components, m 总 T1 represents the total mass of the fuel cell stack and small cycle components, T2 represents the target temperature, and T1 represents the current temperature.

[0053] A third aspect of this application provides a vehicle, including: 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 method for calculating the starting current of the fuel cell stack as described in the above embodiments.

[0054] A fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the method for calculating the starting current of a fuel cell stack as described in the above embodiments.

[0055] Therefore, by obtaining the current and target temperatures of the coolant outlet, and determining the total heat requirement for low-temperature startup based on these temperatures, the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane are obtained. The startup current of the fuel cell stack is then calculated based on the total heat requirement, the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane. This solves the problem in related technologies that fail to couple the total heat requirement for low-temperature startup of the fuel cell stack and do not consider the impact of fuel cell stack water production on startup, leading to low-temperature startup failure or excessively long low-temperature startup times. It ensures that the heat generated by the fuel cell is sufficient to suppress the freezing rate and rapidly raise the fuel cell stack temperature above the freezing point of the reaction water, thus shortening the low-temperature startup time. Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0056] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0057] Figure 1 This is a flowchart illustrating a method for calculating the startup current of a fuel cell stack according to an embodiment of this application.

[0058] Figure 2 This is a flowchart of a cryogenic startup method for a fuel cell stack according to an embodiment of this application;

[0059] Figure 3 A block diagram of a device for calculating the starting current of an electric stack according to an embodiment of this application;

[0060] Figure 4 This is a structural schematic diagram of a vehicle provided according to an embodiment of this application. Detailed Implementation

[0061] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0062] The following description, with reference to the accompanying drawings, details a method, apparatus, vehicle, and storage medium for calculating the startup current of a fuel cell stack according to embodiments of this application. Addressing the issues mentioned in the background art, such as the failure to couple the total heat demand for low-temperature startup of the fuel cell stack and the lack of consideration for the impact of fuel cell stack water production on startup, leading to low-temperature startup failure or excessively long startup times, this application provides a method for calculating the startup current of a fuel cell stack. In this method, the current temperature and target temperature of the coolant outlet are obtained, and the total heat demand for low-temperature startup is determined based on these temperatures. The heat production of the fuel cell stack, the heat production of the PTC heater, and the maximum water content of the proton exchange membrane are also obtained. The startup current of the fuel cell stack is calculated based on the total heat demand, the heat production of the fuel cell stack, the heat production of the PTC heater, and the maximum water content of the proton exchange membrane. This solves the problems of related technologies failing to couple the total heat demand for low-temperature startup and neglecting the impact of fuel cell stack water production on startup, resulting in low-temperature startup failure or excessively long startup times. It ensures that the heat generated by the fuel cell is sufficient to suppress the freezing rate and rapidly raise the fuel cell stack temperature above the freezing point of the reaction water, thus shortening the low-temperature startup time.

[0063] Specifically, Figure 1 This is a flowchart illustrating a method for calculating the starting current of an electric stack, as provided in an embodiment of this application.

[0064] like Figure 1 As shown, the calculation method for the starting current of this fuel cell stack includes the following steps:

[0065] In step S101, the current temperature and target temperature of the coolant outlet are obtained.

[0066] It should be noted that the method for calculating the starting current of the fuel cell stack in this application embodiment is applicable to a low-temperature start-up method for the fuel cell stack. This low-temperature start-up method is divided into three stages. In the first stage, from the start-up of the low-temperature stack to the receipt of the actuator ice-breaking end signal of the fuel cell system, the PTC heats the stack alone. In the second stage, from the receipt of the actuator ice-breaking end signal of the fuel cell system to the coolant outlet temperature reaching the target temperature, the PTC and the fuel cell stack heat the stack together. In the third stage, from the coolant outlet temperature reaching the target temperature to the vehicle power reaching the idle power, the fuel cell stack heats the stack alone.

[0067] The current temperature at the coolant outlet is the temperature obtained when the actuator's ice-breaking end signal is received, and the target temperature is the temperature at the end of the second stage. Preferably, the target temperature can be 0 degrees Celsius.

[0068] It is understandable that when the coolant temperature reaches 0 degrees, the coolant will no longer be at risk of freezing. At this time, the heating of the PTC can be stopped to save energy. Therefore, the target temperature T2 of the second stage can be 0 degrees Celsius. In this embodiment of the application, the current temperature T1 of the coolant outlet can be obtained by the coolant sensor.

[0069] Optionally, in some embodiments, after obtaining the current temperature and target temperature of the coolant outlet, the method further includes: obtaining the ambient temperature of the current vehicle location, the initial temperature of the coolant outlet, and the heating time required for the temperature to rise from the initial temperature to the current temperature; if the initial temperature is greater than the ambient temperature, determining the temperature rise rate of the coolant outlet based on the initial temperature, the current temperature, and the heating time; otherwise, determining the temperature rise rate of the coolant outlet based on the ambient temperature, the current temperature, and the heating time; and determining the heating power of the PTC heater based on the temperature rise rate of the coolant outlet, so as to obtain the heat generation of the PTC heater based on the heating power of the PTC heater.

[0070] Specifically, in this embodiment, when the vehicle has a low-temperature start requirement, the initial temperature of the coolant outlet is obtained, and a first duration of PTC heating is determined upon receiving the actuator de-icing end signal. If the initial temperature of the coolant outlet is higher than the ambient temperature, a first temperature difference between the current temperature of the coolant outlet and the initial temperature of the coolant outlet is determined, and the temperature rise rate of the coolant outlet is obtained by dividing the first temperature difference by the first duration. If the initial temperature of the coolant outlet is less than or equal to the ambient temperature, a second temperature difference between the current temperature of the coolant outlet and the ambient temperature is determined, and the temperature rise rate of the coolant outlet is obtained by dividing the second temperature difference by the first duration. After determining the temperature rise rate of the coolant outlet, the heating power of the PTC heater is determined based on the temperature rise rate of the coolant outlet. Through the above technical means, this embodiment can reduce the influence of ambient temperature on the PTC heating power.

[0071] In step S102, the total heat required for low-temperature startup is determined based on the current temperature and the target temperature, and the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane are obtained.

[0072] Specifically, the total heat demand is:

[0073] Q 需 =C P *m 总 *(T2-T1); (1)

[0074] Among them, Q 需 For total heat demand, C P For the total specific heat capacity of the fuel cell stack and small circulation components, m 总 T1 represents the total mass of the fuel cell stack and small cycle components, T2 represents the target temperature, and T1 represents the current temperature.

[0075] In the second stage, the PTC and the fuel cell stack are heated together, therefore,

[0076] Q 需 =Q stack +Q ptc (2)

[0077] Among them, Q stack Q represents the heat generated by the fuel cell stack. ptc This refers to the heat generated by the PTC.

[0078] The heat generated by the fuel cell stack is:

[0079]

[0080] Among them, Q stack Where N is the heat generated by the fuel cell stack, V0 is the number of cells, V0 is the stack voltage when the current power of the fuel cell system reaches the idle power, and I is the starting current of the fuel cell stack.

[0081] In the second stage, the heat generated by the PTC heater is:

[0082] Q ptc =P v *(t-t0); (4)

[0083] Among them, Q ptc P is the heat output of the PTC heater. v t is the heating power of the PTC heater, t0 is the time corresponding to the current temperature of the coolant outlet, and t is the time corresponding to the time to reach the target temperature.

[0084] Furthermore, in some embodiments, before calculating the startup current of the fuel cell based on the total heat demand, the heat generated by the fuel cell stack, the heat generated by the PTC heater, and the maximum water content of the proton exchange membrane, the method further includes: obtaining the current high-frequency impedance of the fuel cell stack; determining the remaining water content of the membrane electrode based on the current high-frequency impedance based on a preset high-frequency impedance-membrane electrode water content mapping relationship, and determining the maximum freezing water content of the fuel cell stack based on the current high-frequency impedance based on a preset high-frequency impedance-maximum freezing water content mapping relationship; and determining the maximum water content of the proton exchange membrane based on the difference between the maximum freezing water content and the remaining water content of the membrane electrode.

[0085] It should be noted that the maximum water content of a proton exchange membrane is the critical point for maintaining its optimal performance. At this water content, the membrane's proton conductivity reaches its peak, ensuring efficient battery operation. However, exceeding this critical point may lead to membrane swelling and deterioration of mechanical properties.

[0086] Those skilled in the art will understand that when the fuel cell stack meets the condition that the maximum ice-forming water content > the remaining water content of the membrane electrode assembly (MEA) + the water production of the fuel cell, the melting rate is greater than the freezing rate. In this case, the fuel cell stack is less likely to fail to start at low temperatures due to water freezing. Conversely, if the fuel cell stack does not meet the condition that the maximum ice-forming water content > the remaining water content of the MEA + the water production of the fuel cell, the melting rate is less than the freezing rate. In this case, water freezing can completely obstruct the gas reaction channels, leading to low-temperature start-up failure. If the sum of the remaining water content of the MEA and the water production from the electrochemical reaction exceeds the maximum ice-forming water content that the MEA can withstand, it will cause ice to completely block the reaction channels, leading to low-temperature start-up failure. The embodiments of this application can control the maximum water content of the proton exchange membrane to ensure the fuel cell operates at its optimal performance. At this water content, the membrane's proton conductivity is optimal, ensuring efficient battery operation.

[0087] Specifically, in this embodiment of the application, the mapping relationship between high-frequency impedance and residual water content of membrane electrode under low-temperature sensitivity of the fuel cell stack and the preset mapping relationship between high-frequency impedance and maximum freezing water content can be obtained in advance through a test bench.

[0088] The embodiments of this application can obtain the current high-frequency impedance of the fuel cell stack, and obtain the remaining water content of the membrane electrode and the maximum freezing water content based on the high-frequency impedance, the preset high-frequency impedance-membrane electrode residual water content mapping relationship, and the preset high-frequency impedance-maximum freezing water content mapping relationship.

[0089]

[0090] The water production capacity of the fuel cell stack is:

[0091]

[0092] Where, m H20 Let N be the water production rate of the fuel cell stack, t be the target time, t0 be the initial time, N be the number of solar cells, I be the starting current, F be the Faraday constant, and M be the starting current. H20 The molar mass of the product water.

[0093] The maximum water content of a proton exchange membrane is:

[0094]

[0095] in, λm is the maximum water content of the proton exchange membrane, β is the water content coefficient of the proton exchange membrane, t0 is the time corresponding to the current temperature at the coolant outlet, t is the time corresponding to the target temperature, and N is the number of solar cells. Let I be the molar mass of water, I be the starting current of the fuel cell stack, and F be the Faraday constant.

[0096] In step S103, the start-up current of the fuel cell stack is calculated based on the total heat demand, the heat generated by the fuel cell stack, the heat generated by the PTC heater, and the maximum water content of the proton exchange membrane.

[0097] Specifically, after determining the total heat demand, the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane, the starting current I of the fuel cell stack and the time t corresponding to reaching the target temperature can be calculated by combining formulas (1)(2)(3)(4) and (7).

[0098] Therefore, the embodiments of this application can couple the total heat required for low-temperature start-up of the fuel cell, and calculate the start-up current of the fuel cell stack based on the characteristics of the water production of the fuel cell stack. This ensures that the heat generated by the fuel cell is sufficient to suppress the freezing rate and rapidly increase the temperature of the fuel cell stack away from the freezing point of the reaction water, thereby improving the success rate of low-temperature start-up and shortening the low-temperature start-up time.

[0099] The battery starting current calculation method of this application embodiment is applied to the following low-temperature starting method for vehicles.

[0100] like Figure 2 As shown, Figure 2 This is a flowchart of a low-temperature starting method for a vehicle provided according to an embodiment of this application.

[0101] S0: When the vehicle has a low-temperature start requirement, obtain the ambient temperature of the current vehicle location and the initial temperature of the coolant outlet, and determine the heating power of the PTC heater based on the ambient temperature and the initial temperature of the coolant outlet.

[0102] S1, the vehicle enters the first stage of low-temperature start-up, controlling the PTC heater to heat with heating power and controlling the actuator to perform ice breaking.

[0103] S2, obtain the signal that the actuator has finished breaking ice, and obtain the current temperature and target temperature of the coolant outlet. Determine the total heat demand of the vehicle based on the current temperature and target temperature of the coolant outlet, and determine the target starting current of the battery based on the total heat demand.

[0104] The target starting current is calculated as follows:

[0105] The total heat demand is determined based on the target temperature and current temperature of the coolant outlet.

[0106] Q 需 =C P *m 总 *(T2-T1);

[0107] The total heat demand is generated by both the PTC and the fuel cell stack.

[0108] Q需 =Q stack +Q ptc ;

[0109] The heat generated by the fuel cell stack is:

[0110]

[0111] The heat output of the PTC heater is:

[0112] Q ptc =P v *(t-t0);

[0113] The maximum water content of a proton exchange membrane is:

[0114]

[0115] Combining the above formulas, we can obtain the target starting current I and the time corresponding to reaching the target temperature.

[0116] S3, the vehicle enters the second stage of low-temperature start-up, controlling the PTC and fuel cell stack to heat together. The PTC heater heats with heating power, and the fuel cell stack heats with the target start-up current.

[0117] S4. When the coolant outlet temperature reaches the target temperature, the vehicle enters the third stage of low-temperature start-up, stops the PTC heater, obtains the real-time temperature of the coolant outlet, determines the load current of the fuel cell stack based on the real-time temperature, and controls the fuel cell stack to be heated separately with the load current until the vehicle's power reaches the idle power.

[0118] According to the method for calculating the start-up current of the fuel cell stack proposed in this application, the current temperature and target temperature of the coolant outlet are obtained, and the total heat required for low-temperature start-up is determined based on the current temperature and target temperature. The heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane are also obtained. The start-up current of the fuel cell stack is then calculated based on the total heat required, the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane. This solves the problems of related technologies failing to couple the total heat required for low-temperature start-up of the fuel cell stack and not considering the impact of fuel cell stack water production on start-up, leading to low-temperature start-up failure or excessively long low-temperature start-up times. It ensures that the heat generated by the fuel cell is sufficient to suppress the freezing rate and rapidly increase the fuel cell stack temperature above the freezing point of the reaction water, thus shortening the low-temperature start-up time.

[0119] Next, with reference to the accompanying drawings, a device for calculating the starting current of a fuel cell stack according to an embodiment of this application is described.

[0120] Figure 3 This is a block diagram of a device for calculating the starting current of a fuel cell stack according to an embodiment of this application.

[0121] like Figure 3 As shown, the calculation device 10 for the starting current of the fuel cell stack includes: a first acquisition module 100, a second acquisition module 200, and a calculation module 300.

[0122] The first acquisition module 100 is used to acquire the current temperature and target temperature of the coolant outlet.

[0123] The second acquisition module 200 is used to determine the total heat required for low-temperature startup based on the current temperature and the target temperature, and to acquire the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane.

[0124] The calculation module 300 is used to calculate the start-up current of the fuel cell based on the total heat demand, the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane.

[0125] Optionally, in some embodiments, before calculating the startup current of the fuel cell based on the total required heat, the heat generated by the fuel cell, the heat generated by the PTC heater, and the maximum water content of the proton exchange membrane, the calculation module 300 further includes: a first acquisition unit, a first determination unit, and a second determination unit.

[0126] The first acquisition unit is used to acquire the current high-frequency impedance of the fuel cell stack.

[0127] The first determining unit is used to determine the residual water content of the membrane electrode of the fuel cell stack based on the current high-frequency impedance according to the preset high-frequency impedance-membrane electrode residual water content mapping relationship, and to determine the maximum freezing water content of the fuel cell stack based on the current high-frequency impedance according to the preset high-frequency impedance-maximum freezing water content mapping relationship.

[0128] The second determining unit is used to determine the maximum water content of the proton exchange membrane based on the difference between the maximum freezing water content and the remaining water content of the membrane electrode.

[0129] Optionally, in some embodiments, the maximum water content of the proton exchange membrane is:

[0130]

[0131] in, γm represents the maximum water content of the proton exchange membrane, β represents the water content coefficient of the proton exchange membrane, t0 represents the time corresponding to the current temperature at the coolant outlet, t represents the time corresponding to the target temperature, and N represents the number of solar cells. Let I be the molar mass of water, I be the starting current of the fuel cell stack, and F be the Faraday constant.

[0132] Optionally, in some embodiments, the heat generated by the PTC heater is:

[0133] Q ptc =Pv v *(t-t0);

[0134] Among them, Q ptc P is the heat output of the PTC heater. v t is the heating power of the PTC heater, t0 is the time corresponding to the current temperature at the coolant outlet, and t is the time corresponding to the target temperature.

[0135] Optionally, in some embodiments, after obtaining the current temperature and target temperature of the coolant outlet, the first acquisition module 100 further includes: a second acquisition unit, a third determination unit, and a generation unit.

[0136] The second acquisition unit is used to acquire the ambient temperature of the current vehicle location, the initial temperature of the coolant outlet, and the heating time from the initial temperature to the current temperature.

[0137] The third determining unit is used to determine the temperature rise rate of the coolant outlet based on the initial temperature, the current temperature, and the heating time if the initial temperature is higher than the ambient temperature; otherwise, it determines the temperature rise rate of the coolant outlet based on the ambient temperature, the current temperature, and the heating time.

[0138] The generation unit is used to determine the heating power of the PTC heater based on the temperature rise rate of the coolant outlet, so as to obtain the heat generation of the PTC heater based on the heating power of the PTC heater.

[0139] Optionally, in some embodiments, the heat generation of the fuel cell stack is:

[0140]

[0141] Among them, Q stack Where N is the heat generated by the fuel cell stack, V0 is the number of cells, V0 is the stack voltage when the current power of the fuel cell system reaches the idle power, and I is the starting current of the fuel cell stack.

[0142] Optionally, in some embodiments, the total heat demand is:

[0143] Q 需 =C P *m 总 *(T2-T1);

[0144] Among them, Q 需 For total heat demand, C P For the total specific heat capacity of the fuel cell stack and small circulation components, m 总 T1 represents the total mass of the fuel cell stack and small cycle components, T2 represents the target temperature, and T1 represents the current temperature.

[0145] It should be noted that the explanation of the above-described method for calculating the starting current of the fuel cell stack also applies to the device for calculating the starting current of the fuel cell stack in this embodiment, and will not be repeated here.

[0146] The fuel cell stack start-up current calculation device proposed in this application obtains the current temperature and target temperature of the coolant outlet, determines the total heat required for low-temperature start-up based on the current and target temperatures, and obtains the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane. It then calculates the fuel cell stack start-up current based on the total heat required, the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane. This solves the problems of related technologies failing to couple the total heat required for low-temperature start-up of the fuel cell stack and failing to consider the impact of fuel cell stack water production on start-up, leading to low-temperature start-up failure or excessively long low-temperature start-up times. It ensures that the heat generated by the fuel cell is sufficient to suppress the freezing rate and rapidly raise the fuel cell stack temperature above the freezing point of the reaction water, thus shortening the low-temperature start-up time.

[0147] Figure 4 A schematic diagram of the structure of a vehicle provided in an embodiment of this application. The vehicle may include:

[0148] The memory 401, the processor 402, and the computer program stored on the memory 401 and capable of running on the processor 402.

[0149] When the processor 402 executes the program, it implements the method for calculating the starting current of the fuel cell stack provided in the above embodiments.

[0150] Furthermore, the vehicle also includes:

[0151] Communication interface 403 is used for communication between memory 401 and processor 402.

[0152] The memory 401 is used to store computer programs that can run on the processor 402.

[0153] The memory 401 may include high-speed RAM (Random Access Memory) memory, and may also include non-volatile memory, such as at least one disk storage.

[0154] If the memory 401, processor 402, and communication interface 403 are implemented independently, then the communication interface 403, memory 401, and processor 402 can be interconnected via a bus to complete communication between them. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 4 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0155] Optionally, in a specific implementation, if the memory 401, processor 402, and communication interface 403 are integrated on a single chip, then the memory 401, processor 402, and communication interface 403 can communicate with each other through an internal interface.

[0156] Processor 402 may be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement embodiments of this application.

[0157] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for calculating the starting current of the fuel cell stack.

[0158] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0159] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0160] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0161] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (FPGAs), field-programmable gate arrays (FPGAs), etc.

[0162] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0163] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for calculating the starting current of an electric fuel cell stack, characterized in that, Includes the following steps: Obtain the current temperature and target temperature of the coolant outlet; The total heat required for low-temperature startup is determined based on the current temperature and the target temperature, and the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane are obtained. Obtain the current high-frequency impedance of the fuel cell stack; Based on a preset high-frequency impedance-membrane electrode residual water content mapping relationship, the membrane electrode residual water content of the fuel cell stack is determined according to the current high-frequency impedance, and based on a preset high-frequency impedance-maximum freezing water content mapping relationship, the maximum freezing water content of the fuel cell stack is determined according to the current high-frequency impedance. The maximum water content of the proton exchange membrane is determined based on the difference between the maximum freezing water content and the remaining water content of the membrane electrode. The starting current of the fuel cell stack is calculated based on the total heat demand, the heat generated by the fuel cell stack, the heat generated by the PTC heater, and the maximum water content of the proton exchange membrane. The maximum water content of the proton exchange membrane is: ； in, The maximum water content of the proton exchange membrane. The water content coefficient of the proton exchange membrane. The proton exchange membrane reverse osmosis coefficient, The time corresponding to the current temperature at the coolant outlet. The time corresponding to the target temperature. This refers to the number of battery cells. The molar mass of water, This is the starting current of the fuel cell stack. is Faraday's constant.

2. The method according to claim 1, characterized in that, The heat generated by the PTC heater is: ； in, The heat output of the PTC heater, The heating power of the PTC heater. The time corresponding to the current temperature at the coolant outlet. The time corresponding to the target temperature.

3. The method according to claim 1 or 2, characterized in that, After obtaining the current temperature and target temperature of the coolant outlet, the method further includes: The ambient temperature at the current location of the vehicle, the initial temperature of the coolant outlet, and the heating time from the initial temperature to the current temperature are obtained. If the initial temperature is greater than the ambient temperature, the temperature rise rate of the coolant outlet is determined based on the initial temperature, the current temperature, and the heating duration; otherwise, the temperature rise rate of the coolant outlet is determined based on the ambient temperature, the current temperature, and the heating duration. The heating power of the PTC heater is determined based on the temperature rise rate at the coolant outlet, so as to obtain the heat generation of the PTC heater based on the heating power of the PTC heater.

4. The method according to claim 1, characterized in that, The heat generated by the fuel cell stack is: ； in, The heat generated by the fuel cell stack, This refers to the number of battery cells. This refers to the stack voltage of the fuel cell system when its current power reaches idle speed. The starting current of the fuel cell stack is given.

5. The method according to claim 1, characterized in that, The total required heat is: ； in, The total required heat, For the total specific heat capacity of the fuel cell stack and small circulation components, This refers to the total mass of the fuel cell stack and small-cycle components. The target temperature, The current temperature is [value].

6. A device for calculating the starting current of a fuel cell stack, the device being used to implement the method as described in any one of claims 1-5, characterized in that, include: The first acquisition module is used to acquire the current temperature and target temperature of the coolant outlet; The second acquisition module is used to determine the total heat required for low-temperature start-up based on the current temperature and the target temperature, and to acquire the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane. The calculation module is used to calculate the start-up current of the fuel cell stack based on the total heat demand, the heat generation of the fuel cell stack, the heat generation of the PTC heater, and the maximum water content of the proton exchange membrane.

7. A vehicle, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the method for calculating the startup current of the fuel cell stack as described in any one of claims 1-5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the method for calculating the startup current of the fuel cell stack as described in any one of claims 1-5.

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