Low-temperature cold start method and device of fuel cell, vehicle, medium and product

Abstract

The invention relates to the technical field of vehicles, in particular to a low-temperature cold start method and device for a fuel cell, a vehicle, a medium and a product, and the method comprises the steps: obtaining the environment temperature of an area where the fuel cell is located; if the environment temperature is lower than the first low-temperature cold start threshold value, a target cold start strategy of the fuel cell is obtained, and the target cold start strategy comprises target operation voltage for increasing stack heat production and target cooling liquid flow speed for reducing cooling liquid heat dissipation; and controlling the fuel cell to start based on the target cold start strategy. Therefore, the problems that a fuel cell low-temperature cold start strategy in the related technology is insufficient in the aspects of protection and practical applicability of the fuel cell stack and the like are solved.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a low-temperature cold start method, device, vehicle, medium and product of a fuel cell. Background Art

[0002] Fuel cell vehicles, as a clean energy transportation tool, have received extensive attention and development. Ensuring the normal start-up of the fuel cell system in cold climate conditions is a key technical challenge. At present, there are two main strategies for cold start of fuel cells under low temperature conditions: CC (Constant Current) and CV (Constant Voltage). Both methods are designed to quickly activate the chemical reaction in the fuel cell under low temperature conditions, thereby achieving rapid start-up.

[0003] In actual operation, most startup strategies excessively pursue shortening the startup time, ignoring the impact on the fuel cell stack itself. Excessive pursuit of shortening the startup time may lead to excessive heat generation, which in turn damages the structure of the fuel cell stack and affects its service life. It is impossible to take into account both the startup speed and the health status management of the fuel cell stack. At the same time, most of the existing low-temperature cold start strategies are designed based on the extreme low temperature environment of -30℃.

[0004] But in fact, during winter use, the temperature of the coolant in fuel cell vehicles is usually maintained at around -25°C. This temperature difference makes the start-up strategy designed according to the -30°C standard ineffective in actual application and cannot well meet the actual operation needs of fuel cell vehicles in winter. Summary of the invention

[0005] The present application provides a low-temperature cold start method, device, vehicle, medium and product for a fuel cell to solve the problems that the low-temperature cold start strategy of the fuel cell in the related art is insufficient in terms of protection of the fuel cell stack and practical applicability.

[0006] A first aspect of the present application provides a low-temperature cold start method for a fuel cell, comprising the following steps: obtaining the ambient temperature of the area where the fuel cell is located; if the ambient temperature is lower than a first low-temperature cold start threshold, obtaining a target cold start strategy for the fuel cell, wherein the target cold start strategy includes increasing a target operating voltage for heat generation of the stack and reducing a target coolant flow rate for heat dissipation of the coolant; and controlling the start-up of the fuel cell based on the target cold start strategy.

[0007] Optionally, obtaining a target cold start strategy for the fuel cell includes: if the ambient temperature is higher than a second low-temperature cold start threshold, the target cold start strategy is a first cold start strategy, otherwise the target cold start strategy is a second cold start strategy.

[0008] Optionally, the first cold start strategy includes: setting a target coolant flow rate of the first circulation loop of the fuel cell; controlling the first circulation loop according to the target coolant flow rate, and monitoring the minimum cell voltage of the fuel cell; if the minimum cell voltage is greater than a preset voltage, controlling the current of the stack to increase according to the first target current until the coolant inlet temperature of the fuel cell is greater than or equal to a first preset temperature, and when the coolant inlet temperature is greater than or equal to a second preset temperature, controlling the fuel cell to switch from the first circulation loop to the second circulation loop.

[0009] Optionally, the second cold start strategy includes: setting a target coolant flow rate of the first circulation loop of the fuel cell; controlling the first circulation loop according to the target coolant flow rate, and monitoring the minimum cell voltage of the fuel cell; if the minimum cell voltage is greater than a preset voltage, controlling the current increase of the fuel cell stack according to the second target current until the current of the fuel cell stack reaches the second target current, and then controlling the current increase of the fuel cell stack according to the third target current until the coolant inlet temperature of the fuel cell stack is greater than or equal to the third preset temperature; controlling the current increase of the fuel cell stack according to the fourth target current until the current of the fuel cell stack reaches the fourth target current, and then controlling the current increase of the fuel cell stack according to the fifth target current until the current of the fuel cell stack reaches the fifth target current, and then controlling the current increase of the fuel cell stack according to the sixth target current, and when the coolant inlet temperature is greater than or equal to the first preset temperature, controlling the fuel cell to switch from the first circulation loop to the second circulation loop.

[0010] Optionally, before monitoring the minimum cell voltage of the fuel cell, it also includes: starting the hydrogen supply of the fuel cell, setting a target hydrogen flow rate and a target hydrogen inlet pressure of the fuel cell, and monitoring the current hydrogen inlet pressure of the fuel cell; if the current hydrogen inlet pressure is greater than a preset pressure, starting the air supply of the fuel cell, and setting the target air flow rate and the target air inlet pressure of the fuel cell.

[0011] Optionally, the circulation path length of the second circulation loop is greater than the circulation path length of the first circulation loop.

[0012] A second aspect of the present application provides a low-temperature cold start device for a fuel cell, including: a first acquisition module, used to acquire the ambient temperature of the area where the fuel cell is located; a second acquisition module, used to acquire a target cold start strategy for the fuel cell if the ambient temperature is lower than a first low-temperature cold start threshold, wherein the target cold start strategy includes increasing a target operating voltage for heat generation of the stack and reducing a target coolant flow rate for heat dissipation of the coolant; and a control module, used to control the start-up of the fuel cell based on the target cold start strategy.

[0013] A third aspect of the present application provides a vehicle, 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 low-temperature cold start method of the fuel cell of the first aspect.

[0014] The fourth aspect of the present application provides a computer-readable storage medium having a computer program or instruction stored thereon. When the computer program or instruction is executed, the low-temperature cold start method of the fuel cell of the first aspect is implemented.

[0015] The fifth aspect of the present application provides a computer program product, including a computer program or instructions, which, when executed, implements the low-temperature cold start method of the fuel cell of the first aspect.

[0016] Therefore, this application includes the following beneficial effects:

[0017] The embodiment of the present application obtains the ambient temperature of the area where the fuel cell is located, obtains the target cold start strategy of the fuel cell when the ambient temperature is lower than the first low-temperature cold start threshold, and controls the start of the fuel cell based on the target cold start strategy, thereby protecting the fuel cell stack, using different cold start strategies according to different low-temperature environments, and optimizing the winter vehicle experience in all scenarios. Thus, the problems of the low-temperature cold start strategy of the fuel cell in the related art in terms of protection of the fuel cell stack and practical applicability are solved.

[0018] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0020] Figure 1 A flowchart of a low-temperature cold start method for a fuel cell provided according to an embodiment of the present application;

[0021] Figure 2 A judgment logic diagram of a low-temperature cold start method for a fuel cell provided according to an embodiment of the present application;

[0022] Figure 3 A first cold start strategy flow chart provided according to an embodiment of the present application;

[0023] Figure 4 A second cold start strategy flow chart provided according to an embodiment of the present application;

[0024] Figure 5A first cold start strategy measured data diagram provided according to an embodiment of the present application;

[0025] Figure 6 A graph of measured data of a second cold start strategy provided according to an embodiment of the present application;

[0026] Figure 7 This is a block diagram of a low-temperature cold start device for a fuel cell according to an embodiment of the present application;

[0027] Figure 8 It is a schematic diagram of the structure of a vehicle according to an embodiment of the present application. DETAILED DESCRIPTION

[0028] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0029] The following describes the low-temperature cold start method, device, vehicle, medium and product of the fuel cell of the embodiment of the present application with reference to the accompanying drawings. In view of the problems that the low-temperature cold start strategy of the fuel cell in the related art mentioned in the above background technology is insufficient in terms of protection of the fuel cell stack and practical applicability, the present application provides a low-temperature cold start method for a fuel cell. In this method, by obtaining the ambient temperature of the area where the fuel cell is located, when the ambient temperature is lower than the first low-temperature cold start threshold, the target cold start strategy of the fuel cell is obtained, and the fuel cell is started based on the target cold start strategy, thereby protecting the stack, realizing the use of different cold start strategies according to different low-temperature environments, and optimizing the winter vehicle experience in all scenarios. As a result, the problems that the low-temperature cold start strategy of the fuel cell in the related art is insufficient in terms of protection of the fuel cell stack and practical applicability are solved.

[0030] Specifically, Figure 1 A schematic flow chart of a low-temperature cold start method for a fuel cell provided in an embodiment of the present application.

[0031] like Figure 1 As shown, the low temperature cold start method of the fuel cell comprises the following steps:

[0032] In step S101, the ambient temperature of the area where the fuel cell is located is obtained.

[0033] The ambient temperature may be obtained through a temperature sensor.

[0034] It is understandable that the embodiment of the present application can use a temperature sensor or other means to obtain the ambient temperature of the area where the fuel cell is located.

[0035] In step S102, if the ambient temperature is lower than the first low-temperature cold start threshold, a target cold start strategy for the fuel cell is obtained, wherein the target cold start strategy includes increasing a target operating voltage for heat generation of the fuel cell stack and reducing a target coolant flow rate for heat dissipation of the coolant.

[0036] Among them, the first low-temperature cold start threshold is a temperature value set according to actual needs. It is set according to actual needs and is not specifically limited here. If it is lower than the first low-temperature cold start threshold, the target cold start strategy of the fuel cell is obtained; a higher target operating voltage can increase the heat generation of the fuel cell stack; the coolant temperature can be adjusted by controlling the flow rate of the coolant, thereby adjusting the temperature of the fuel cell stack, and the target coolant flow rate can reduce the heat dissipation of the coolant.

[0037] It can be understood that the embodiment of the present application sets a first low-temperature cold start threshold according to actual needs, and obtains the target cold start strategy of the fuel cell when the temperature is lower than the first low-temperature cold start threshold, including increasing the target operating voltage for heat generation of the fuel cell stack and reducing the target coolant flow rate for coolant heat dissipation. By reasonably setting the target operating voltage and the target coolant flow rate, a faster and more effective cold start can be achieved without sacrificing the life of the fuel cell stack.

[0038] In an embodiment of the present application, a target cold start strategy for the fuel cell is obtained, including: if the ambient temperature is higher than a second low-temperature cold start threshold, the target cold start strategy is a first cold start strategy, otherwise the target cold start strategy is a second cold start strategy.

[0039] Among them, the second low-temperature cold start threshold is a temperature value set according to actual needs, which is set according to actual needs and is not specifically limited here; the first cold start strategy and the second cold start strategy will be described in detail below and will not be repeated here.

[0040] It can be understood that the embodiment of the present application obtains the target cold start strategy of the fuel cell when the ambient temperature is lower than the first low-temperature cold start threshold. The target cold start strategy of the fuel cell is determined based on the ambient temperature and the second low-temperature cold start threshold. When the ambient temperature is higher than the second low-temperature cold start threshold, the first cold start strategy is the target cold start strategy; when the ambient temperature is lower than the second low-temperature cold start threshold, the second cold start strategy is the target cold start strategy.

[0041] In an embodiment of the present application, a first cold start strategy includes: setting a target coolant flow rate of a first circulation loop of the fuel cell; controlling the first circulation loop according to the target coolant flow rate, and monitoring the minimum cell voltage of the fuel cell; if the minimum cell voltage is greater than a preset voltage, controlling the current of the stack to increase according to the first target current until the coolant inlet temperature of the fuel cell is greater than or equal to a first preset temperature, and when the coolant inlet temperature is greater than or equal to a second preset temperature, controlling the fuel cell to switch from the first circulation loop to the second circulation loop.

[0042] The target coolant flow rate is set according to actual needs and is not specifically limited here; the first circulation loop is a small circulation loop; the second circulation loop is a large circulation loop; monitoring the minimum single cell voltage of the fuel cell can be achieved by setting a voltage sensor on each single cell; the preset voltage is set at 700-850mV according to actual needs; the first target current is set at 0.8-1A / cm according to actual needs 2 The corresponding current of the current density; the first preset temperature is a temperature value to ensure that the battery stack can operate stably without causing damage to the battery stack due to excessive temperature, and is set at 40-60°C according to actual conditions; the second preset temperature is a temperature value set according to actual needs. The second circulation loop operates when it is greater than the second preset temperature. In order to avoid the performance degradation of the battery stack caused by low-temperature shock during the switching process between large and small cycles, the second preset temperature value is set at 25-50°C according to actual conditions.

[0043] It can be understood that when the embodiment of the present application executes the first cold start strategy, the first circulation loop is first controlled according to the set target coolant flow rate, and the minimum cell voltage of the fuel cell is monitored by means of a voltage sensor, etc. When the minimum cell voltage is greater than a preset voltage, the current control load is started, and the current of the stack is controlled to increase according to the first target current, so that the coolant entering the stack temperature of the fuel cell increases until the temperature is greater than or equal to the first preset temperature, and the fuel cell is controlled to switch from the first circulation loop to the second circulation loop, and in this process it is necessary to ensure that the coolant entering the stack temperature is greater than or equal to the second preset temperature.

[0044] In an embodiment of the present application, the second cold start strategy includes: setting a target coolant flow rate of the first circulation loop of the fuel cell; controlling the first circulation loop according to the target coolant flow rate, and monitoring the minimum cell voltage of the fuel cell; if the minimum cell voltage is greater than a preset voltage, controlling the current increase of the fuel cell stack according to the second target current until the current of the fuel cell stack reaches the second target current, and then controlling the current increase of the fuel cell stack according to the third target current until the coolant inlet temperature of the fuel cell stack is greater than or equal to the third preset temperature; controlling the current increase of the fuel cell stack according to the fourth target current until the current of the fuel cell stack reaches the fourth target current, and then controlling the current increase of the fuel cell stack according to the fifth target current until the current of the fuel cell stack reaches the fifth target current, and then controlling the current increase of the fuel cell stack according to the sixth target current, and when the coolant inlet temperature is greater than or equal to the first preset temperature, controlling the fuel cell to switch from the first circulation loop to the second circulation loop.

[0045] The second target current is set at 0.2A / cm 2 The corresponding current of the current density; the third target current, the fourth target current, the fifth target current and the sixth target current as well as the third preset temperature are specifically set according to actual needs and are not specifically limited here.

[0046] It can be understood that when the embodiment of the present application executes the second cold start strategy, the first circulation loop is first controlled according to the set target coolant flow rate and the minimum cell voltage of the fuel cell is monitored by means of a voltage sensor or the like. When the minimum cell voltage is greater than the preset voltage, the current control is started to pull the load, and the current increase of the fuel cell stack is controlled according to the second target current. After the load current reaches the second target current, the load current continues to be pulled to the third target current, and the current increase of the fuel cell stack is controlled according to the third target current, so that the coolant entering the stack temperature of the fuel cell increases until the temperature is greater than or equal to the third preset temperature, and the current increase of the fuel cell stack is controlled according to the fourth target current, until the current of the fuel cell stack reaches the fourth target current, and the current increase of the fuel cell stack is controlled according to the fifth target current, until the current of the fuel cell stack reaches the fifth target current, and the current increase of the fuel cell stack is controlled according to the sixth target current, until the temperature is greater than or equal to the first preset temperature, the fuel cell is controlled to switch from the first circulation loop to the second circulation loop, and in this process, it is necessary to ensure that the coolant entering the stack temperature is greater than or equal to the second preset temperature.

[0047] In the embodiment of the present application, the circulation path length of the second circulation loop is greater than the circulation path length of the first circulation loop.

[0048] Among them, the second circulation loop, namely the large circulation loop, involves a longer pipeline path and a higher flow rate, which helps to better manage and control the operating temperature of the fuel cell stack and prevent overheating. It is suitable for the state where the fuel cell stack has reached the operating temperature and requires continuous heat dissipation; the first circulation loop is a small circulation loop with a shorter path and a lower flow rate, which is conducive to quickly heating the fuel cell stack to reach the operating temperature.

[0049] It can be understood that in the embodiment of the present application, the circulation path length of the second circulation loop is greater than the circulation path length of the first circulation loop, which is conducive to better management and control of the operating temperature of the battery stack and prevents overheating. It is suitable for the state where the battery stack has reached the operating temperature and requires continuous heat dissipation.

[0050] In an embodiment of the present application, before monitoring the minimum single cell voltage of the fuel cell, it also includes: starting the hydrogen supply of the fuel cell, setting the target hydrogen flow rate and target hydrogen inlet pressure of the fuel cell, and monitoring the current hydrogen inlet pressure of the fuel cell; if the current hydrogen inlet pressure is greater than the preset pressure, starting the air supply of the fuel cell, and setting the target air flow rate and target air inlet pressure of the fuel cell.

[0051] The preset pressure is set according to actual needs and is not specifically limited here; monitoring the current hydrogen inlet pressure can be achieved through a sensor.

[0052] It can be understood that the embodiment of the present application turns on the hydrogen supply to the fuel cell, sets the target hydrogen flow rate and target hydrogen inlet pressure of the fuel cell with reference to the hydrogen supply of the fuel cell stack at the current current density, monitors the current hydrogen inlet pressure of the fuel cell through a sensor, and when the current hydrogen inlet pressure of the fuel cell stack is greater than the preset pressure, turns on the air supply to the fuel cell, sets the target air flow rate and target air inlet pressure of the fuel cell with reference to the air supply of the fuel cell stack at the current current density, and utilizes a large-flow air supply to drain the water generated by the cold start of the fuel cell stack in time to avoid frost and ice formation causing cold start failure.

[0053] In step S103 , the fuel cell startup is controlled based on the target cold start strategy.

[0054] It can be understood that after the embodiment of the present application obtains the target cold start strategy, it works according to the target cold start strategy, thereby controlling the fuel cell to start quickly without damaging the fuel cell stack.

[0055] According to the low-temperature cold start method of the fuel cell proposed in the embodiment of the present application, by obtaining the ambient temperature of the area where the fuel cell is located, when the ambient temperature is lower than the first low-temperature cold start threshold, the target cold start strategy of the fuel cell is obtained, and the start-up of the fuel cell is controlled based on the target cold start strategy, thereby protecting the fuel cell stack, using different cold start strategies according to different low-temperature environments, and optimizing the full-scenario winter vehicle use experience.

[0056] The low temperature cold start method of a fuel cell is further described below through a specific embodiment, as follows:

[0057] This embodiment is based on the cold start principle formula of the battery stack: Q heat generation > Q heat dissipation + CpΔT, optimizes the cold start strategy, increases the self-heat generation of the battery stack by reducing the operating voltage, and reduces the heat loss caused by the coolant. Two sets of coolant strategies are formulated, and their judgment logic is as follows: Figure 2 shown.

[0058] Depend on Figure 2 As shown, when the ambient temperature is greater than 0°C, the low-temperature cold start strategy is not adopted; when the ambient temperature is between -20°C and 0°C, the first cold start strategy is adopted; when the ambient temperature is below -20°C, the second cold start strategy is adopted. The first cold start strategy and the second cold start strategy are introduced below.

[0059] When the ambient temperature is between -20℃ and 0℃, the first cold start strategy process is as follows Figure 3 As shown:

[0060] Step S201: Setting the minimum small-circulation coolant flow rate F coolant to a value between 5 and 50 LPM;

[0061] Step S202: Hydrogen supply, reference stack at a current density of 0.8 to 1 A / cm 2 , the hydrogen supply quantity is set at a metering ratio of 1.8 to 2.5 to ensure that the anode inlet pressure quickly reaches the set value P_An_in after hydrogen is supplied, and the value can be between 1.3 and 1.8 bara; this step is to ensure that all valve bodies, flow meters, sensors, etc. in the hydrogen circuit work normally, proving that hydrogen can be supplied normally;

[0062] Step S203: Determine whether the anode inlet pressure reaches the set value P_An_in. If so, proceed to step S204.

[0063] Step S204: Start the air supply, and the reference stack is at a current density of 0.8 to 1 A / cm 2 , the air supply volume is set at a metering ratio of 2.5 to 5; this step is to ensure that all valves, flow meters, sensors, etc. in the air path work properly, prove that the air can be supplied normally, and use a large flow of air to drain the water generated by the cold start of the stack in time to avoid frost and ice causing cold start failure;

[0064] Step S205: Determine whether the minimum cell voltage U_min reaches a preset voltage (to avoid high open circuit potential accelerating stack performance degradation, the preset voltage is set at 700-850 mV). If so, proceed to step S206.

[0065] Step S206: Start current control loading and slowly load the current to the first target current (the value is set at 0.8-1A / cm 2 The process controls the current I=IX*(Y-Umin) (X refers to 0.1-0.2, Y refers to 200-400).

[0066] Step S207: monitor the stack coolant inlet temperature T_coolant in in real time, and determine whether T_coolant in is greater than or equal to a first preset temperature. If T coolant_in> the first preset temperature (to ensure that the stack can operate stably and will not be damaged due to excessive temperature, the first preset temperature is set at 40-60°C), proceed to step S208, otherwise proceed to step S206.

[0067] Step S208: Adjust the electronically controlled three-way valve to gradually switch to the large-cycle cooling circuit. During this process, it is necessary to ensure that T_coolantin>the second preset temperature (to avoid the low-temperature shock during the switching process between the large and small cycles causing the performance degradation of the battery stack. The second preset temperature is set at 25-50°C).

[0068] Step S209: The cold start is successful, and the control strategy is switched to normal temperature operation.

[0069] When the ambient temperature is -30℃ or lower than -20℃, the second cold start strategy is adopted. The process is as follows Figure 4 As shown:

[0070] Step S301: Set the minimum small-circulation coolant flow rate F coolant to 5-50 LPM; start the hydrogen supply, with the reference stack at a current density of 0.8-1 A / cm 2 , the hydrogen supply quantity is set at a metering ratio of 1.8 to 2.5 to ensure that the anode inlet pressure quickly reaches the set value P_An_in after hydrogen is supplied, and the value can be between 1.3 and 1.8 bara; this step is to ensure that all valve bodies, flow meters, sensors, etc. in the hydrogen circuit work normally, proving that hydrogen can be supplied normally;

[0071] Step S302: Determine whether the anode inlet pressure reaches the set value P_An_in. If so, proceed to step S303.

[0072] Step S303: Start the air supply, and the reference stack is at a current density of 0.8 to 1 A / cm 2 , the air supply volume is set at a metering ratio of 2.5 to 5; this step is to ensure that all valves, flow meters, sensors, etc. in the air path work properly, prove that the air can be supplied normally, and use a large flow of air to drain the water generated by the cold start of the stack in time to avoid frost and ice causing cold start failure;

[0073] Step S304: Determine whether the minimum cell voltage U_min reaches a preset voltage (to avoid high open circuit potential accelerating the degradation of the stack performance, the preset voltage is set at 700-850 mV). If so, proceed to step S305.

[0074] Step S305: Start current control loading and slowly load the current to the second target current (the value is set at 0.2A / cm 2 The current density corresponds to the current), and the current rise slope is controlled in this process ≤ the current loading slope setting value 1 (to avoid the stack being short of gas due to ice blockage of the GDL channel. The value is set at 20-30A / s and should be dynamically adjusted according to different temperatures. The lower the temperature, the slower the loading slope);

[0075] Step S306: After the current is pulled to the second target current, the current is continued to be pulled to the third target current. The process controls the current I=I-X1*(Y1-Umin) (X1 refers to 0.05-0.2, Y1 refers to 100-150);

[0076] Step S307: real-time monitoring of the stack cathode outlet temperature T_Ca out, judging whether T_Ca out is greater than or equal to the third preset temperature, if it is greater than or equal to the third preset temperature, opening the small cycle to the set speed 1 (opening all small cycles may cause severe thermal shock and cause a single low emergency stop, so the small cycle should be reasonably opened according to the actual coolant volume, and the set speed 1 refers to 30-60% of the rated speed);

[0077] Step S308: After starting the small cycle, pull the current to the fourth target current, and the process controls the current I=I-X2*(Y2-Umin) (X2 refers to 0.1-0.3, Y2 refers to 300-400);

[0078] Step S309: real-time monitoring of the stack coolant inlet temperature T_coolant_in, when T coolant_in> the third preset temperature, start the small cycle to set the speed 2 (set speed 2 refers to 80-100% of the rated speed);

[0079] Step S310: pull the current to the fifth target current, and the process controls the current I=I-X3*(Y3-Umin) (X3 refers to 0.2-0.4, Y3 refers to 50-150);

[0080] Step S311: pull the current to the sixth target current, and the process controls the current I=I-X4*(Y4-Umin) (X4 refers to 0.05-0.2, Y4 refers to 200-400);

[0081] Step S312: real-time monitoring of the stack coolant inlet and outlet temperatures T_coolantin&out, when T coolant_in&out> the first preset temperature (to ensure that the stack can operate stably without damaging the stack due to excessive temperature, the first preset temperature is set at 40-60°C), the electronically controlled three-way valve is adjusted to gradually switch to the large-circulation cooling path, and during this process, it is necessary to ensure that T_coolant in> the second set temperature (to avoid the low-temperature shock during the switching process between large and small cycles causing the stack performance to decay, the second set temperature is set at 25-50°C);

[0082] Step S313: The cold start is successful, and the control strategy is switched to normal temperature operation.

[0083] The schematic diagram of the measured data of the first cold start strategy at -20℃ low temperature is as follows Figure 5 As shown in the figure, the measured data of the second cold start strategy at -30℃ low temperature is shown in Figure 6 As shown. The difference between the first cold start strategy and the second cold start strategy is that the second cold start strategy uses the heat generated by the working of the stack to increase the body temperature as much as possible, and reduces the heat dissipation of the stack by stopping or reducing the flow of coolant in the stack. At the same time, in order to avoid the danger of local overheating of the stack due to the lack of circulating coolant refrigeration, the thresholds of the coolant inlet and outlet temperature and the stack air outlet temperature are judged from two aspects, to provide safety protection while reducing cold and hot shocks. The load slope adopts adaptive closed-loop logic control, and the minimum single-chip control current is used to effectively improve the low-temperature startup stability. That is, the stack can be quickly self-started at different ambient temperatures, while ensuring the safe and healthy operation of the stack.

[0084] Next, a low-temperature cold start device for a fuel cell according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0085] Figure 7 It is a block diagram of a low-temperature cold start device for a fuel cell according to an embodiment of the present application.

[0086] like Figure 7 As shown, the low-temperature cold starting device 10 of the fuel cell includes: a first acquisition module 401 , a second acquisition module 402 and a control module 403 .

[0087] Among them, the first acquisition module 401 is used to obtain the ambient temperature of the area where the fuel cell is located; the second acquisition module 402 is used to obtain the target cold start strategy of the fuel cell if the ambient temperature is lower than the first low-temperature cold start threshold, wherein the target cold start strategy includes increasing the target operating voltage for heat generation of the stack and reducing the target coolant flow rate for heat dissipation of the coolant; the control module 403 is used to control the start-up of the fuel cell based on the target cold start strategy.

[0088] In the embodiment of the present application, the second acquisition module 402 is further used for: if the ambient temperature is higher than the second low-temperature cold start threshold, the target cold start strategy is the first cold start strategy, otherwise the target cold start strategy is the second cold start strategy.

[0089] In an embodiment of the present application, a first cold start strategy includes: setting a target coolant flow rate of a first circulation loop of the fuel cell; controlling the first circulation loop according to the target coolant flow rate, and monitoring the minimum cell voltage of the fuel cell; if the minimum cell voltage is greater than a preset voltage, controlling the current of the stack to increase according to the first target current until the coolant inlet temperature of the fuel cell is greater than or equal to a first preset temperature, and when the coolant inlet temperature is greater than or equal to a second preset temperature, controlling the fuel cell to switch from the first circulation loop to the second circulation loop.

[0090] In an embodiment of the present application, the second cold start strategy includes: setting a target coolant flow rate of the first circulation loop of the fuel cell; controlling the first circulation loop according to the target coolant flow rate, and monitoring the minimum cell voltage of the fuel cell; if the minimum cell voltage is greater than a preset voltage, controlling the current increase of the fuel cell stack according to the second target current until the current of the fuel cell stack reaches the second target current, and then controlling the current increase of the fuel cell stack according to the third target current until the coolant inlet temperature of the fuel cell stack is greater than or equal to the third preset temperature; controlling the current increase of the fuel cell stack according to the fourth target current until the current of the fuel cell stack reaches the fourth target current, and then controlling the current increase of the fuel cell stack according to the fifth target current until the current of the fuel cell stack reaches the fifth target current, and then controlling the current increase of the fuel cell stack according to the sixth target current, and when the coolant inlet temperature is greater than or equal to the first preset temperature, controlling the fuel cell to switch from the first circulation loop to the second circulation loop.

[0091] In an embodiment of the present application, before monitoring the minimum single cell voltage of the fuel cell, it also includes: starting the hydrogen supply of the fuel cell, setting the target hydrogen flow rate and target hydrogen inlet pressure of the fuel cell, and monitoring the current hydrogen inlet pressure of the fuel cell; if the current hydrogen inlet pressure is greater than the preset pressure, starting the air supply of the fuel cell, and setting the target air flow rate and target air inlet pressure of the fuel cell.

[0092] In the embodiment of the present application, the circulation path length of the second circulation loop is greater than the circulation path length of the first circulation loop.

[0093] It should be noted that the above explanation of the low-temperature cold starting method embodiment of a fuel cell is also applicable to the low-temperature cold starting device of the fuel cell of this embodiment, and will not be repeated here.

[0094] According to the low-temperature cold start device for the fuel cell proposed in the embodiment of the present application, the ambient temperature of the area where the fuel cell is located is acquired through the first acquisition module, and the second acquisition module acquires the target cold start strategy of the fuel cell. The control module controls the start-up of the fuel cell based on the target cold start strategy to ensure lossless start-up of the fuel cell stack, thereby realizing the use of different cold start strategies according to different low-temperature environments and optimizing the full-scenario winter vehicle use experience.

[0095] Figure 8 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application. The vehicle may include:

[0096] A memory 501 , a processor 502 , and a computer program stored in the memory 501 and executable on the processor 502 .

[0097] When the processor 502 executes the program, the low-temperature cold start method of the fuel cell provided in the above embodiment is implemented.

[0098] Furthermore, the vehicle also includes:

[0099] The communication interface 503 is used for communication between the memory 501 and the processor 502 .

[0100] The memory 501 is used to store computer programs that can be executed on the processor 502 .

[0101] The memory 501 may include a high-speed RAM (Random Access Memory) memory, and may also include a non-volatile memory, such as at least one disk memory.

[0102] If the memory 501, the processor 502 and the communication interface 503 are implemented independently, the communication interface 503, the memory 501 and the processor 502 can be connected to each other through a bus and communicate with each other. 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 an address bus, a data bus, a control bus, etc. For ease of representation, Figure 5 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0103] Optionally, in a specific implementation, if the memory 501, the processor 502 and the communication interface 503 are integrated on a chip, the memory 501, the processor 502 and the communication interface 503 can communicate with each other through an internal interface.

[0104] The processor 502 may be a CPU (Central Processing Unit), or an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present application.

[0105] The embodiment of the present application also provides a computer-readable storage medium on which a computer program or instruction is stored. When the computer program or instruction is executed, the low-temperature cold start method of the fuel cell described above is implemented.

[0106] The embodiment of the present application also provides a computer program product, including a computer program or instructions, which, when executed, implements the above-mentioned low-temperature cold start method of the fuel cell.

[0107] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0108] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0109] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0110] It should be understood that the various parts of the present application can be implemented in hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, the steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array, a field programmable gate array, etc.

[0111] A person of ordinary skill in the art may understand that all or part of the steps carried by the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the above-mentioned program may be stored in a computer-readable storage medium, which, when executed, includes one of the steps of the method embodiment or a combination thereof.

[0112] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A low temperature cold start method for a fuel cell, characterized in that: The following steps are involved: Obtaining the ambient temperature of the area where the fuel cell is located; If the ambient temperature is lower than a first low-temperature cold start threshold, a target cold start strategy for the fuel cell is obtained, wherein the target cold start strategy includes increasing a target operating voltage for heat generation of the fuel cell stack and reducing a target coolant flow rate for heat dissipation of the coolant; The fuel cell startup is controlled based on the target cold start strategy.

2. The low temperature cold start method of a fuel cell according to claim 1, characterized in that: The obtaining of the target cold start strategy of the fuel cell comprises: If the ambient temperature is higher than a second low-temperature cold start threshold, the target cold start strategy is the first cold start strategy; otherwise, the target cold start strategy is the second cold start strategy.

3. The low temperature cold start method of a fuel cell according to claim 2, characterized in that: The first cold start strategy includes: setting a target coolant flow rate for a first circulation loop of the fuel cell; controlling the first circulation loop according to the target coolant flow rate and monitoring the minimum cell voltage of the fuel cell; If the minimum single cell voltage is greater than a preset voltage, the current of the fuel cell stack is controlled to increase according to the first target current until the temperature of the coolant entering the stack of the fuel cell is greater than or equal to a first preset temperature. When the temperature of the coolant entering the stack is greater than or equal to a second preset temperature, the fuel cell is controlled to switch from the first circulation loop to the second circulation loop.

4. The low temperature cold start method of a fuel cell according to claim 2, characterized in that: The second cold start strategy includes: setting a target coolant flow rate for a first circulation loop of the fuel cell; controlling the first circulation loop according to the target coolant flow rate and monitoring the minimum cell voltage of the fuel cell; If the lowest cell voltage is greater than a preset voltage, the current of the stack is controlled to increase according to the second target current until the current of the stack reaches the second target current, and then the current of the stack is controlled to increase according to the third target current until the temperature of the coolant entering the stack of the fuel cell is greater than or equal to a third preset temperature; The current of the fuel cell stack is controlled to increase according to the fourth target current until the current of the fuel cell stack reaches the fourth target current. The current of the fuel cell stack is controlled to increase according to the fifth target current until the current of the fuel cell stack reaches the fifth target current. The current of the fuel cell stack is controlled to increase according to the sixth target current, and when the temperature of the coolant entering the stack is greater than or equal to the first preset temperature, the fuel cell is controlled to switch from the first circulation loop to the second circulation loop.

5. The low temperature cold start method of a fuel cell according to claim 3 or 4, characterized in that: Before monitoring the minimum cell voltage of the fuel cell, the method further comprises: Turning on the hydrogen supply of the fuel cell, setting a target hydrogen flow rate and a target hydrogen inlet pressure of the fuel cell, and monitoring a current hydrogen inlet pressure of the fuel cell; If the current hydrogen inlet pressure is greater than the preset pressure, the air supply to the fuel cell is turned on, and a target air flow rate and a target air inlet pressure to the fuel cell are set.

6. The low temperature cold start method of a fuel cell according to claim 3 or 4, characterized in that: The circulation path length of the second circulation loop is greater than the circulation path length of the first circulation loop.

7. A low temperature cold start device for a fuel cell, characterized in that: include: A first acquisition module is used to acquire the ambient temperature of the area where the fuel cell is located; A second acquisition module is used to acquire a target cold start strategy of the fuel cell if the ambient temperature is lower than a first low-temperature cold start threshold, wherein the target cold start strategy includes increasing a target operating voltage for heat generation of the fuel cell stack and reducing a target coolant flow rate for heat dissipation of the coolant; A control module is used to control the start-up of the fuel cell based on the target cold start strategy.

8. 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 low-temperature cold start method for a fuel cell according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: When the computer program or instruction is executed, the low-temperature cold start method of the fuel cell according to any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed, the low-temperature cold start method of the fuel cell according to any one of claims 1 to 6 is implemented.

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