Fuel cell control method, device and system and vehicle

Abstract

The invention discloses a fuel cell control method, device and system and a vehicle, and the fuel cell control method is applied to the vehicle and comprises the following steps: obtaining a first actual measurement parameter of an anode cavity and a second actual measurement parameter of a cathode cavity of a fuel cell in a power-off state of the vehicle; according to the first actual measurement parameter and the second actual measurement parameter, estimating the complete reaction time of the fuel in the anode cavity and the maximum permeation time when the amount of oxygen permeating from the cathode cavity to the anode cavity reaches a preset oxygen threshold value; determining an anode purging period according to the complete reaction time and the maximum permeation time; and according to the anode purging period, purging the anode cavity until the vehicle is started. According to the technical scheme, the oxygen content in the anode cavity is limited, a contact interface of fuel and oxygen in the anode cavity during a parking period or when a vehicle is started next time can be effectively avoided, temporary high potential of an electric pile of the fuel cell is avoided, and the service life of the electric pile of the fuel cell can be greatly prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and particularly to a fuel cell control method, device, system and vehicle. Background Art

[0002] Currently, after a fuel cell vehicle parks or the fuel cell engine shuts down, the hydrogen in the anode chamber of the fuel cell reacts with the oxygen remaining in the cathode chamber, resulting in a decrease in the hydrogen pressure in the anode chamber. At the same time, there is still a certain leakage rate in the air shut-off valve in the fuel cell system in the closed state, and air will slowly enter the cathode chamber and then penetrate through the proton exchange membrane into the anode chamber. When the oxygen in the anode chamber accumulates to a certain amount, when hydrogen is injected during the next fuel cell startup, the hydrogen and oxygen will meet to form a hydrogen-air interface, which will cause a high potential of the stack, leading to carbon carrier corrosion and catalyst loss, and damaging the stack life. Summary of the Invention

[0003] Embodiments of the present invention provide a fuel cell control method, device, system and vehicle to solve the problem that when a conventional fuel cell vehicle starts, hydrogen and oxygen meet to form a hydrogen-air interface, affecting the service life of the fuel cell.

[0004] A fuel cell control method, where the fuel cell is applied to a vehicle, includes: In the power-off state of the vehicle, obtain the first measured parameter of the anode chamber of the fuel cell and the second measured parameter of the cathode chamber; According to the first measured parameter and the second measured parameter, estimate the complete reaction time of the fuel in the anode chamber and the maximum penetration time for the oxygen amount penetrating from the cathode chamber to the anode chamber to reach a preset oxygen threshold; According to the complete reaction time and the maximum penetration time, determine the anode purge period; According to the anode purge period, purge the anode chamber until the vehicle starts.

[0005] Further, the step of estimating the complete reaction time of the fuel in the anode chamber and the maximum penetration time for the oxygen amount penetrating from the cathode chamber to the anode chamber to reach a preset oxygen threshold according to the first measured parameter and the second measured parameter includes: According to the first measured parameter, obtain the fuel content in the anode chamber; According to the second measured parameter, obtain the oxygen content in the cathode chamber; According to the fuel content and the oxygen content, estimate the complete reaction time of the fuel in the anode chamber; Estimate the maximum penetration time for the amount of oxygen penetrating from the cathode chamber to the anode chamber to reach the preset oxygen threshold according to the preset penetration parameters, the second measured parameter, and the oxygen content.

[0006] Further, estimating the complete reaction time of the fuel in the anode chamber according to the fuel content and the oxygen content includes: Determine the first ratio of the oxygen content to the fuel content; If the first ratio is not less than the first threshold, estimate the complete reaction time of the fuel in the anode chamber according to the fuel content and the preset fuel reaction rate; If the first ratio is less than the first threshold, estimate the complete reaction time of the fuel in the anode chamber according to the fuel content, the oxygen content, the preset fuel reaction rate, and the preset oxygen leakage rate.

[0007] Further, estimating the complete reaction time of the fuel in the anode chamber according to the fuel content, the oxygen content, the preset fuel reaction rate, and the preset oxygen leakage rate includes: Obtain the first reaction time according to the fuel content and the preset fuel reaction rate; Obtain the second reaction time according to the fuel content, the oxygen content, and the preset oxygen leakage rate; Determine the sum of the first reaction time and the second reaction time as the complete reaction time of the fuel in the anode chamber.

[0008] Further, the preset penetration parameters include oxygen activation energy, in-membrane water volume fraction, proton exchange membrane thickness, and proton exchange membrane area; the second measured parameters include cathode chamber pressure and cathode chamber temperature; Estimating the maximum penetration time for the amount of oxygen penetrating from the cathode chamber to the anode chamber to reach the preset oxygen threshold according to the preset penetration parameters, the second measured parameter, and the oxygen content includes: Obtain the oxygen permeability according to the cathode chamber temperature, the oxygen activation energy, and the in-membrane water volume fraction; Obtain the oxygen transmembrane penetration rate according to the oxygen permeability, the proton exchange membrane thickness, the proton exchange membrane area, and the cathode chamber pressure; Estimate the maximum penetration time for the amount of oxygen penetrating from the cathode chamber to the anode chamber to reach the preset oxygen threshold according to the preset oxygen leakage rate, the preset oxygen threshold, and the oxygen transmembrane penetration rate.

[0009] Further, estimating the maximum penetration time when the amount of oxygen permeating from the cathode chamber to the anode chamber reaches the preset oxygen threshold according to the preset oxygen leakage rate, the preset oxygen threshold, and the oxygen transmembrane permeation rate includes: If the preset oxygen leakage rate is not less than the oxygen transmembrane permeation rate, determine the maximum penetration time according to the preset oxygen threshold and the oxygen transmembrane permeation rate; If the preset oxygen leakage is less than the oxygen transmembrane permeation rate, determine the maximum penetration time according to the preset oxygen threshold and the preset oxygen leakage rate.

[0010] Further, before obtaining the first measured parameter of the fuel cell anode chamber and the second measured parameter of the cathode chamber in the vehicle power-off state, it includes: Obtain a vehicle power-off request; In response to the vehicle power-off request, perform obtaining the first measured parameter of the fuel cell anode chamber and the second measured parameter of the cathode chamber; estimate the complete reaction time of the fuel in the anode chamber and the maximum penetration time when the amount of oxygen permeating from the cathode chamber to the anode chamber reaches the preset oxygen threshold according to the first measured parameter and the second measured parameter; Determine the first purge time according to the complete reaction time and the maximum penetration time; Control the vehicle to enter the vehicle power-off state, and purge the anode chamber when the vehicle power-off time reaches the first purge time.

[0011] A control device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the above fuel cell control method is implemented.

[0012] A fuel cell system includes a fuel cell, a sensor assembly, a fuel circulation device, and the above control device; The sensor assembly is connected to the fuel cell; The fuel circulation device is connected to the fuel cell; The control device is connected to the sensor assembly and the fuel circulation device.

[0013] A vehicle includes the above fuel cell system.

[0014] Embodiments of the present invention provide a fuel cell control method, apparatus, system, and vehicle. When the vehicle is in a powered-off state, the first measured parameter of the anode chamber of the fuel cell and the second measured parameter of the cathode chamber are obtained. According to the first measured parameter and the second measured parameter, the complete reaction time of the fuel in the anode chamber is estimated, and the maximum penetration time for the oxygen amount penetrating from the cathode chamber to the anode chamber to reach a preset oxygen threshold is estimated. According to the complete reaction time and the maximum penetration time, the anode purge period is determined. According to the anode purge period, the anode chamber is purged until the vehicle starts. It can be determined that when the fuel cell vehicle is shut down and in the powered-off state of the vehicle, by estimating the complete reaction time of the fuel in the anode chamber and the maximum penetration time for the oxygen amount penetrating from the cathode chamber to the anode chamber to reach a preset oxygen threshold, the maximum allowable content of oxygen that can accumulate in the anode chamber is determined. Thus, after the vehicle is powered off, when each anode purge period ends, the anode chamber is automatically purged, restricting the oxygen content in the anode chamber. It can effectively avoid the contact interface of fuel and oxygen in the anode chamber during parking or at the next vehicle start, and avoid the short-term high potential of the fuel cell stack, which can greatly improve the service life of the fuel cell stack. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 is a flowchart of a fuel cell control method in an embodiment of the present invention; Figure 2 is another flowchart of a fuel cell control method in an embodiment of the present invention; Figure 3 is another flowchart of a fuel cell control method in an embodiment of the present invention; Figure 4 is another flowchart of a fuel cell control method in an embodiment of the present invention; Figure 5 is another flowchart of a fuel cell control method in an embodiment of the present invention; Figure 6 is another flowchart of a fuel cell control method in an embodiment of the present invention; Figure 7 is another flowchart of a fuel cell control method in an embodiment of the present invention; Figure 8 is a schematic diagram of a fuel cell system in an embodiment of the present invention; Figure 9 is a schematic diagram of a control device in an embodiment of the present invention. Detailed implementation manners

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0018] It should be understood that the present invention can be implemented in different forms and should not be construed as limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals throughout the drawings denote the same elements.

[0019] It should be understood that when an element or layer is referred to as "on", "adjacent to", "connected to" or "coupled to" another element or layer, it can be directly on, adjacent to, connected or coupled to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as "directly on", "directly adjacent to", "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Thus, the first element, component, region, layer or part discussed below may be denoted as the second element, component, region, layer or part without departing from the teachings of the present invention.

[0020] Spatial relationship terms such as "under", "below", "lower", "beneath", "above", "upper", etc. are used herein for convenience of description to describe the relationship of one element or feature shown in the drawings with other elements or features. It should be understood that, in addition to the orientation shown in the drawings, the spatial relationship terms are intended to also include different orientations of the device during use and operation. For example, if the device in the drawing is flipped, then an element or feature described as "under" or "beneath" or "below" other elements or features will be oriented "above" the other elements or features. Thus, the exemplary terms "under" and "below" can include both the upper and lower orientations. The device can be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are accordingly interpreted.

[0021] The purpose of the terms used herein is only to describe specific embodiments and is not a limitation of the present invention. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, specify the presence of features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups. As used herein, the term "and / or" includes any and all combinations of the related listed items.

[0022] To fully understand the present invention, detailed structures and steps will be presented in the following description to illustrate the technical solutions proposed by the present invention. The preferred embodiments of the present invention are described in detail below. However, in addition to these detailed descriptions, the present invention may have other embodiments.

[0023] This embodiment provides a fuel cell control method applied to a fuel cell system. Exemplarily, the fuel cell system is applied to a vehicle. Optionally, the fuel cell system includes a fuel cell, a sensor assembly, a fuel circulation device 14, and the above control device; the sensor assembly is connected to the fuel cell; the fuel circulation device 14 is connected to the fuel cell; the control device is connected to the sensor assembly and the fuel circulation device 14. Exemplarily, the fuel of the fuel cell includes hydrogen (H2), methanol (CH3OH), natural gas (CH4), liquid ammonia (NH3), etc. Preferably, the fuel of the fuel cell adopted in this embodiment is hydrogen.

[0024] As an example, the fuel cell system includes an air circulation loop, a fuel circulation loop, a temperature control loop, a fuel cell, a sensor assembly, and a control device. The fuel circulation device 14 is disposed in the fuel circulation loop.

[0025] Specifically, as Figure 8 shown, the air circulation loop, the fuel circulation loop, and the temperature control loop are respectively connected to the fuel cell. The sensor assembly is respectively connected to the air circulation loop, the fuel circulation loop, and the temperature control loop. The control device is connected to the sensor assembly and the fuel circulation device 14.

[0026] As an example, as Figure 8As shown in the figure, the air circulation loop includes an air filter 1, an air compressor 2, an intercooler 3, a humidifier 4, an inlet valve to the stack 5, and an outlet valve from the stack 6. The air filter 1 is connected to the input end of the air compressor 2. The output end of the air compressor 2 is connected to the input end of the intercooler 3. The output end of the intercooler 3 is connected to the first input end of the humidifier 4. The output end of the humidifier 4 is connected to the input end of the inlet valve to the stack 5. The output end of the inlet valve to the stack 5 is connected to the fuel cell 23. The input end of the outlet valve from the stack 6 is connected to the fuel cell 23. The output end of the outlet valve from the stack 6 is connected to the second input end of the humidifier 4.

[0027] As an example, as Figure 8 shown, the fuel circulation loop includes a high-pressure gas cylinder 8, a pressure reducing valve 9, a hydrogen injection valve 10, a gas-water separator 12, a fuel circulation device 14, an exhaust valve 13, and a drain valve 20. The output end of the high-pressure gas cylinder 8 is connected to the fuel cell 23 through the pressure reducing valve 9 and the hydrogen injection valve. The fuel cell 23 is connected to the input end of the gas-water separator 12. The first output end of the gas-water separator 12 is connected to the input end of the fuel circulation device 14. The output end of the fuel circulation device 14 is connected to the fuel cell 23 and the hydrogen injection valve 10. The second output end of the gas-water separator 12 is respectively connected to the exhaust valve 13 and the drain valve 20.

[0028] As an example, as Figure 8 shown, the temperature control loop includes a water pump 16, a radiator 19, a three-way valve 17, and a heater. The input end of the water pump 16 is connected to the fuel cell 23. The output end of the water pump 16 is connected to the input end of the radiator 19 and the first end of the three-way valve 17. The output end of the radiator 19 is connected to the second end of the three-way valve 17. The third end of the three-way valve 17 is connected to the input end of the heater. The output end of the heater is connected to the fuel cell 23.

[0029] As an example, as Figure 8 shown, the sensor assembly includes an air inlet pressure sensor to the stack 7, an anode inlet pressure sensor 11, an anode outlet pressure sensor 22, a coolant outlet temperature sensor 21, and a coolant inlet temperature sensor 22. The air inlet pressure sensor to the stack 7 is connected to the connection node between the inlet valve to the stack and the fuel cell 23. The anode inlet pressure sensor 11 is connected to the connection node between the hydrogen injection valve 10 and the fuel cell 23. The anode outlet pressure sensor 22 is connected to the connection node between the fuel cell 23 and the gas-water separator 12. The coolant outlet temperature sensor 21 is connected to the connection node between the fuel cell 23 and the water pump 16. The coolant inlet temperature sensor 22 is connected to the connection node between the heater and the fuel cell 23. The control device is respectively connected to the air inlet pressure sensor to the stack 7, the anode inlet pressure sensor 11, the anode outlet pressure sensor 22, the coolant outlet temperature sensor 21, and the coolant inlet temperature sensor 22.

[0030] This embodiment provides a fuel cell control method, as Figure 1 shown, which is applied to the above control device and includes: S101: In the vehicle power-off state, obtain the first measured parameter of the fuel cell anode chamber and the second measured parameter of the cathode chamber.

[0031] S102: According to the first measured parameter and the second measured parameter, estimate the complete reaction time of the fuel in the anode chamber and the maximum penetration time when the oxygen amount penetrating from the cathode chamber to the anode chamber reaches a preset oxygen threshold.

[0032] S103: Determine the anode purge period according to the complete reaction time and the maximum penetration time.

[0033] S104: Purge the anode chamber according to the anode purge period until the vehicle starts.

[0034] Among them, the first measured parameter is the parameter corresponding to the fuel cell anode chamber. The second measured parameter is the parameter corresponding to the fuel cell cathode chamber. Exemplarily, the first measured parameter includes the anode pressure P a and the temperature T a . The second measured parameter includes the cathode pressure P c , the temperature T c . The complete reaction time refers to the time when the fuel in the anode chamber reacts completely. The preset oxygen threshold is a self-defined threshold. The maximum penetration time is the time when the oxygen amount penetrating from the cathode chamber to the anode chamber reaches the preset oxygen threshold. It should be noted that the determination method of the preset oxygen threshold includes: for the fuel cell stack used, test the maximum oxygen molar amount that can be allowed to exist in the anode chamber without voltage attenuation of the stack, and set it as the preset oxygen threshold n O2_target . The anode purge period refers to the interval time for purging the anode chamber.

[0035] As an example, in step S101, in the vehicle power-off state, obtain the first measured parameter of the fuel cell anode chamber and the second measured parameter of the cathode chamber. In this example, when the control device detects that the vehicle is in the power-off state, obtain the first measured parameter of the fuel cell anode chamber and the second measured parameter of the cathode chamber through the sensor assembly, so as to determine the hydrogen content in the anode chamber and the oxygen content in the cathode chamber of the fuel cell according to the first measured parameter and the second measured parameter subsequently.

[0036] As an example, in step S102, based on the first measured parameter and the second measured parameter, estimate the complete reaction time of the fuel in the anode chamber and the maximum penetration time when the amount of oxygen permeating from the cathode chamber to the anode chamber reaches a preset oxygen threshold. In this example, the control device first obtains the hydrogen content in the anode chamber and the oxygen content in the cathode chamber of the fuel cell according to the first measured parameter and the second measured parameter, and then estimates the complete reaction time of the fuel in the anode chamber and the maximum penetration time when the amount of oxygen permeating from the cathode chamber to the anode chamber reaches a preset oxygen threshold according to a preset estimation strategy. Exemplarily, the preset estimation strategy includes estimating the first measured parameter and the second measured parameter according to preset estimation parameters and estimation logic to obtain the complete reaction time of the fuel in the anode chamber and the maximum penetration time when the amount of oxygen permeating from the cathode chamber to the anode chamber reaches a preset oxygen threshold.

[0037] As an example, in step S103, determine the anode purge period according to the complete reaction time and the maximum penetration time. In this example, the sum of the complete reaction time and the maximum penetration time is determined as the anode purge period.

[0038] As an example, in step S104, purge the anode chamber according to the anode purge period until the vehicle starts. In this example, in the vehicle-off state, every other anode purge period, control the fuel circulation device 14 to purge the anode chamber. When the purge is completed, start the next anode purge period immediately until the control device detects that the vehicle starts.

[0039] In this embodiment, in the vehicle-off state, obtain the first measured parameter of the fuel cell anode chamber and the second measured parameter of the cathode chamber. Based on the first measured parameter and the second measured parameter, estimate the complete reaction time of the fuel in the anode chamber and the maximum penetration time when the amount of oxygen permeating from the cathode chamber to the anode chamber reaches a preset oxygen threshold. Determine the anode purge period according to the complete reaction time and the maximum penetration time. Purge the anode chamber according to the anode purge period until the vehicle starts. It can be judged when the fuel cell vehicle is shut down that in the vehicle-off state, by estimating the complete reaction time of the fuel in the anode chamber and the maximum penetration time when the amount of oxygen permeating from the cathode chamber to the anode chamber reaches a preset oxygen threshold, determine the maximum allowable content of oxygen that can accumulate in the anode chamber. Thus, after the whole vehicle is powered off, when each anode purge period ends, automatically purge the anode chamber, limit the oxygen content in the anode chamber, and effectively avoid the contact interface of fuel and oxygen in the anode chamber during parking or the next vehicle start, and avoid the short-term high potential of the fuel cell stack, which can greatly improve the service life of the fuel cell stack.

[0040] In one embodiment, such as Figure 2As shown, in step S102, based on the first measured parameter and the second measured parameter, estimate the complete reaction time of the fuel in the anode chamber and the maximum penetration time when the amount of oxygen penetrating from the cathode chamber to the anode chamber reaches a preset oxygen threshold, including: S201: Obtain the fuel content in the anode chamber according to the first measured parameter.

[0041] S202: Obtain the oxygen content in the cathode chamber according to the second measured parameter.

[0042] S203: Estimate the complete reaction time of the fuel in the anode chamber based on the fuel content and the oxygen content.

[0043] S204: Estimate the maximum penetration time when the amount of oxygen penetrating from the cathode chamber to the anode chamber reaches the preset oxygen threshold according to the preset penetration parameter, the second measured parameter, and the oxygen content.

[0044] As an example, in steps S201 and S202, the control device, according to the preset cathode chamber volume Vc and anode chamber volume Va, anode pressure P a and temperature T a , cathode pressure P c and temperature T c , uses the ideal gas state equation to obtain the hydrogen molar amount n H2 (i.e., the fuel content) enclosed in the anode chamber at this time and the oxygen molar amount n O2 (i.e., the oxygen content) in the cathode chamber.

[0045] Exemplarily, according to the ideal gas state equation, the hydrogen molar amount enclosed in the anode chamber of the fuel cell stack when the vehicle just shuts down can be obtained , and the oxygen molar amount in the cathode chamber of the fuel cell stack . Among them, n is in mol; P is the pressure in the chamber, in Pa; V is the volume of the chamber, in m3; R is the universal gas constant, in J / (mol·K); T is the temperature at the chamber inlet, in K.

[0046] As an example, in step S203, estimate the complete reaction time of the fuel in the anode chamber based on the fuel content and the oxygen content. In this example, since the oxygen in the cathode chamber will penetrate into the anode chamber, when estimating the complete reaction time of the fuel in the anode chamber, it is necessary to estimate the complete reaction time of the fuel in the anode chamber based on the fuel content and the oxygen content to ensure the accuracy of the complete reaction time.

[0047] As an example, in step S204, according to the preset penetration parameters, the second measured parameter, and the oxygen content, the maximum penetration time for the oxygen amount penetrating from the cathode chamber to the anode chamber to reach the preset oxygen threshold is estimated. The preset penetration parameters are pre-tested parameters. Exemplarily, the preset penetration parameters include oxygen activation energy, in-membrane water volume fraction, proton exchange membrane thickness, and proton exchange membrane area, etc. In this embodiment, according to the preset penetration parameters, the second measured parameter, and the oxygen content, the maximum penetration time for the oxygen amount penetrating from the cathode chamber to the anode chamber to reach the preset oxygen threshold is estimated to determine how long it takes for the anode chamber to accumulate the maximum allowable amount of oxygen, so as to automatically perform anode purge.

[0048] In this embodiment, according to the first measured parameter, the fuel content in the anode chamber is obtained, according to the second measured parameter, the oxygen content in the cathode chamber is obtained, according to the fuel content and the oxygen content, the complete reaction time of the fuel in the anode chamber is estimated, and according to the preset penetration parameters, the second measured parameter, and the oxygen content, the maximum penetration time for the oxygen amount penetrating from the cathode chamber to the anode chamber to reach the preset oxygen threshold is estimated to ensure the accuracy of the complete reaction time and the maximum penetration time.

[0049] In one embodiment, as Figure 3 shown, in step S203, according to the fuel content and the oxygen content, estimating the complete reaction time of the fuel in the anode chamber includes: S301: Determine the first ratio of the oxygen content to the fuel content.

[0050] S302: If the first ratio is not less than the first threshold, then according to the fuel content and the preset fuel reaction rate, estimate the complete reaction time of the fuel in the anode chamber.

[0051] S303: If the first ratio is less than the first threshold, then according to the fuel content, the oxygen content, the preset fuel reaction rate, and the preset oxygen leakage rate, estimate the complete reaction time of the fuel in the anode chamber.

[0052] Wherein, the first ratio refers to the ratio between the oxygen content and the fuel content. The first threshold is a custom-set threshold. This first threshold is used to determine whether the oxygen content in the anode chamber at the current moment is sufficient for the remaining fuel in the anode chamber to completely react. The hydrogen reaction rate β, unit mol / s, when hydrogen and oxygen react in the shutdown state of the fuel cell stack used can be pre-tested in advance.

[0053] It should be noted that when calculating the time for the hydrogen reaction in the anode chamber to complete, it is necessary to first determine whether the closed oxygen content in the cathode chamber can consume the hydrogen in the anode chamber.

[0054] As an example, the first threshold is 1 / 2, and let the first ratio of the oxygen content to the fuel content be nO2 / n H2 , if n O2 / n H2 ≥ 1 / 2, the oxygen content is sufficient for all the hydrogen to react, so the complete reaction time of hydrogen in the anode chamber . Among them, β is the preset fuel reaction rate. n H2 is the fuel content.

[0055] As another example, if n O2 / n H2 < 1 / 2, the oxygen content cannot make all the hydrogen in the anode chamber react, so it is necessary to wait for the outside air to slowly leak into the cathode. Therefore, in this embodiment, according to the fuel content, oxygen content, preset fuel reaction rate and preset oxygen leakage rate, the complete reaction time of fuel in the anode chamber is estimated to ensure the accuracy of the complete reaction time of fuel in the anode chamber when the first ratio is less than the first threshold.

[0056] In this embodiment, the first ratio of the oxygen content to the fuel content is determined. If the first ratio is not less than the first threshold, the complete reaction time of the fuel in the anode chamber is estimated according to the fuel content and the preset fuel reaction rate. If the first ratio is less than the first threshold, the complete reaction time of the fuel in the anode chamber is estimated according to the fuel content, oxygen content, preset fuel reaction rate and preset oxygen leakage rate, so as to estimate the complete reaction time of the fuel by combining the actual leakage amount and permeation amount of oxygen, ensuring the accuracy of the estimated complete reaction time.

[0057] In one embodiment, as Figure 4 shown, in step S303, according to the fuel content, oxygen content, preset fuel reaction rate and preset oxygen leakage rate, the complete reaction time of the fuel in the anode chamber is estimated, including: S401: Obtain the first reaction time according to the fuel content and the preset fuel reaction rate.

[0058] S402: Obtain the second reaction time according to the fuel content, oxygen content and preset oxygen leakage rate.

[0059] S403: Determine the sum of the first reaction time and the second reaction time as the complete reaction time of the fuel in the anode chamber.

[0060] Among them, the preset oxygen leakage rate is the forward leakage rate of oxygen at the inlet and outlet cut-off valves of the cathode of the fuel cell stack. In this example, the forward leakage rate f of oxygen at the inlet and outlet cut-off valves of the cathode of the fuel cell stack can be pre-tested by the testing techniques well-known to those skilled in the art, which will not be elaborated here.

[0061] As an example, in steps S401 to S403, when the oxygen content cannot cause all the hydrogen in the anode chamber to react, it is necessary to wait for the outside air to slowly leak into the cathode chamber. At this time, the reaction time of hydrogen is calculated in two parts: First, according to step S401, calculate the reaction time of the existing oxygen and hydrogen in the cathode chamber, that is, according to the fuel content and the preset fuel reaction rate, obtain the first reaction time. Second, according to step S402, calculate the time for the oxygen required for the remaining hydrogen to react to leak into the cathode chamber, that is, according to the fuel content, oxygen content, and preset oxygen leakage rate, obtain the second reaction time. Since the reaction rate of hydrogen and oxygen is much greater than the oxygen leakage rate, the time for the oxygen required for the remaining hydrogen to react to leak into the cathode chamber, that is, the second reaction time, is . Determine the sum of the first reaction time and the second reaction time as the complete reaction time of the fuel in the anode chamber. .

[0062] In this embodiment, according to the fuel content and the preset fuel reaction rate, obtain the first reaction time. According to the fuel content, oxygen content, and preset oxygen leakage rate, obtain the second reaction time. Determine the sum of the first reaction time and the second reaction time as the complete reaction time of the fuel in the anode chamber, so as to ensure the accuracy of the complete reaction time of the fuel in the anode chamber when the first ratio is less than the first threshold.

[0063] In one embodiment, as Figure 5 shown, in step S204, the preset penetration parameters include oxygen activation energy, in-membrane water volume fraction, proton exchange membrane thickness, and proton exchange membrane area; the second measured parameters include cathode chamber pressure and cathode chamber temperature; according to the preset penetration parameters, the second measured parameters, and the oxygen content, estimate the maximum penetration time for the oxygen amount penetrating from the cathode chamber to the anode chamber to reach the preset oxygen threshold, including: S501: Obtain the oxygen permeability according to the cathode chamber temperature, oxygen activation energy, and in-membrane water volume fraction.

[0064] S502: Obtain the oxygen transmembrane penetration rate according to the oxygen permeability, proton exchange membrane thickness, proton exchange membrane area, and cathode chamber pressure.

[0065] S503: Estimate the maximum penetration time for the oxygen amount penetrating from the cathode chamber to the anode chamber to reach the preset oxygen threshold according to the preset oxygen leakage rate, preset oxygen threshold, and oxygen transmembrane penetration rate.

[0066] As an example, in step S501, due to the tiny leakage of the air inlet and outlet shut-off valves, as the oxygen in the cathode chamber continuously reacts, the outside air will continuously enter the cathode chamber through the inlet and outlet shut-off valves, and the oxygen will permeate across the membrane from the cathode chamber into the anode chamber. Therefore, the permeation rate of oxygen into the anode chamber is related to the pressure and temperature. In this example, by obtaining the oxygen permeability according to the cathode chamber temperature, the activation energy of oxygen, and the volume fraction of water in the membrane, the calculation accuracy of the oxygen permeability can be ensured. Exemplarily, the oxygen permeability is: , where is the volume fraction of water in the membrane, and its relationship with temperature can be measured in advance according to the fuel cell stack used and used as a known quantity; is the activation energy of oxygen, with the unit kJ / mol; T is the cathode chamber temperature, with the unit K.

[0067] As an example, in step S502, after obtaining the oxygen permeability, the oxygen transmembrane permeation rate can be obtained according to the oxygen permeability, the thickness of the proton exchange membrane, the area of the proton exchange membrane, and the cathode chamber pressure, so as to obtain the permeation rate of oxygen permeating from the cathode chamber to the anode chamber. The oxygen transmembrane permeation rate is . Among them, is the oxygen transmembrane permeation rate, with the unit mol / s; is the oxygen permeability, with the unit mol·cm / s / cm2 / Pa, A is the area of the proton exchange membrane, with the unit cm2; is the cathode pressure, with the unit Pa; d is the thickness of the proton exchange membrane, with the unit cm.

[0068] As an example, in step S503, after obtaining the oxygen transmembrane permeation rate, the maximum permeation time for the oxygen amount permeating from the cathode chamber to the anode chamber to reach the preset oxygen threshold is evaluated by combining the oxygen transmembrane permeation rate and the preset oxygen leakage rate, that is, the maximum permeation time for the oxygen amount permeating from the cathode chamber to the anode chamber to reach the preset oxygen threshold.

[0069] In this embodiment, the oxygen permeability is obtained according to the cathode chamber temperature, the activation energy of oxygen, and the volume fraction of water in the membrane. The oxygen transmembrane permeation rate is obtained according to the oxygen permeability, the thickness of the proton exchange membrane, the area of the proton exchange membrane, and the cathode chamber pressure. The maximum permeation time for the oxygen amount permeating from the cathode chamber to the anode chamber to reach the preset oxygen threshold is estimated according to the preset oxygen leakage rate, the preset oxygen threshold, and the oxygen transmembrane permeation rate. Thus, by combining the preset oxygen leakage rate, the preset oxygen threshold, and the oxygen transmembrane permeation rate, the maximum permeation time for the oxygen amount permeating from the cathode chamber to the anode chamber to reach the preset oxygen threshold is accurately obtained.

[0070] In one embodiment, as Figure 6As shown, in step S503, estimating the maximum penetration time when the amount of oxygen penetrating from the cathode chamber to the anode chamber reaches the preset oxygen threshold according to the preset oxygen leakage rate, the preset oxygen threshold, and the oxygen transmembrane penetration rate includes: S601: If the preset oxygen leakage rate is not less than the oxygen transmembrane penetration rate, determine the maximum penetration time according to the preset oxygen threshold and the oxygen transmembrane penetration rate; S602: If the preset oxygen leakage is less than the oxygen transmembrane penetration rate, determine the maximum penetration time according to the preset oxygen threshold and the preset oxygen leakage rate.

[0071] As an example, the preset oxygen leakage rate is f, the oxygen transmembrane penetration rate is , and the preset oxygen threshold is .

[0072] If f ≥ , then determine the maximum penetration time as according to the preset oxygen threshold and the oxygen transmembrane penetration rate; If f < , then determine the maximum penetration time as according to the preset oxygen threshold and the preset oxygen leakage rate.

[0073] In this embodiment, by comparing the preset oxygen leakage rate and the oxygen transmembrane penetration rate, the influencing factors of the maximum penetration time are judged, and then the corresponding calculation logic is selected to ensure the accuracy of the maximum penetration time.

[0074] In one embodiment, as Figure 7 shown, before step S101, when the vehicle is in the power-off state, before obtaining the first measured parameter of the fuel cell anode chamber and the second measured parameter of the cathode chamber, it includes: S701: Obtain the vehicle power-off request.

[0075] S702: In response to the vehicle power-off request, execute obtaining the first measured parameter of the fuel cell anode chamber and the second measured parameter of the cathode chamber; estimate the complete reaction time of the fuel in the anode chamber and the maximum penetration time when the amount of oxygen penetrating from the cathode chamber to the anode chamber reaches the preset oxygen threshold according to the first measured parameter and the second measured parameter.

[0076] S703: Determine the first purge time according to the complete reaction time and the maximum penetration time.

[0077] S704: Control the vehicle to enter the vehicle power-off state, and purge the anode chamber when the vehicle power-off time reaches the first purge time.

[0078] As an example, after a vehicle power-off request is received, in response to the vehicle power-off request, the first measured parameter of the fuel cell anode chamber and the second measured parameter of the cathode chamber are obtained; based on the first measured parameter and the second measured parameter, the complete reaction time of the fuel in the anode chamber and the maximum penetration time when the amount of oxygen penetrating from the cathode chamber to the anode chamber reaches a preset oxygen threshold are estimated, that is, steps S101 to S102 in the above embodiment, which will not be elaborated here. Based on the complete reaction time and the maximum penetration time, the first purge time is determined, that is, the time for the first purge of the anode chamber after the vehicle is powered off and shut down. When the first purge time is reached after the fuel cell is shut down, the control device automatically executes the anode purge action, the fuel cell engine is shut down, and then steps S101 to S104 in the above embodiment are repeatedly executed to recalculate the anode purge cycle in the current state, realizing the replacement of the anode gas during vehicle parking.

[0079] In this embodiment, when the vehicle is powered off, the anode chamber is first purged, and then the anode purge cycle is re-determined to realize the replacement of the anode gas during vehicle parking, restricting the amount of oxygen in the anode chamber, effectively avoiding the occurrence of a hydrogen-air interface in the anode chamber during the next startup, and also avoiding the occurrence of a hydrogen-air interface in the anode chamber during parking, which can greatly improve the stack life.

[0080] This embodiment provides a control device, as Figure 9 shown, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the above fuel cell control method is implemented.

[0081] This embodiment provides a fuel cell system, including a fuel cell, a sensor assembly, a fuel circulation device 14, and the above control device; the sensor assembly is connected to the fuel cell; the fuel circulation device 14 is connected to the fuel cell; the control device is connected to the sensor assembly and the fuel circulation device 14.

[0082] This embodiment provides a vehicle, including the above fuel cell system.

[0083] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A fuel cell control method, wherein the fuel cell is applied to a vehicle, characterized in that: include: When the vehicle is powered off, obtaining a first measured parameter of the anode chamber and a second measured parameter of the cathode chamber of the fuel cell; According to the first measured parameter and the second measured parameter, estimating the complete reaction time of the fuel in the anode chamber and the maximum permeation time for the oxygen amount permeated from the cathode chamber to the anode chamber to reach a preset oxygen threshold; Determining an anode purge period according to the complete reaction time and the maximum penetration time; The anode cavity is purged according to the anode purging cycle until the vehicle is started.

2. The fuel cell control method according to claim 1, characterized in that: The estimating, based on the first measured parameter and the second measured parameter, the complete reaction time of the fuel in the anode chamber and the maximum permeation time for the amount of oxygen permeating from the cathode chamber to the anode chamber to reach a preset oxygen threshold, comprises: acquiring the fuel content of the anode chamber according to the first measured parameter; acquiring the oxygen content of the cathode chamber according to the second measured parameter; estimating a complete reaction time of the fuel in the anode chamber according to the fuel content and the oxygen content; The maximum permeation time for the amount of oxygen permeating from the cathode chamber to the anode chamber to reach a preset oxygen threshold is estimated according to the preset permeation parameter, the second measured parameter and the oxygen content.

3. The fuel cell control method according to claim 2, characterized in that: The estimating the complete reaction time of the fuel in the anode chamber according to the fuel content and the oxygen content comprises: determining a first ratio of the oxygen content to the fuel content; If the first ratio is not less than a first threshold, estimating a complete reaction time of the fuel in the anode chamber according to the fuel content and a preset fuel reaction rate; If the first ratio is less than the first threshold, the complete reaction time of the fuel in the anode chamber is estimated according to the fuel content, the oxygen content, the preset fuel reaction rate and the preset oxygen leakage rate.

4. The fuel cell control method according to claim 3, characterized in that: The estimating the complete reaction time of the fuel in the anode chamber according to the fuel content, the oxygen content, the preset fuel reaction rate and the preset oxygen leakage rate comprises: Obtaining a first reaction time according to the fuel content and a preset fuel reaction rate; Obtaining a second reaction time according to the fuel content, the oxygen content and the preset oxygen leakage rate; The sum of the first reaction time and the second reaction time is determined as the complete reaction time of the fuel in the anode chamber.

5. The fuel cell control method according to claim 2, characterized in that: The preset permeation parameters include oxygen activation energy, water volume fraction in the membrane, proton exchange membrane thickness and proton exchange membrane area; the second measured parameters include cathode chamber pressure and cathode chamber temperature; The estimating the maximum permeation time for the amount of oxygen permeating from the cathode chamber to the anode chamber to reach a preset oxygen threshold according to the preset permeation parameter, the second measured parameter and the oxygen content includes: Obtaining oxygen permeability according to the cathode chamber temperature, the oxygen activation energy and the water volume fraction in the membrane; Obtaining an oxygen transmembrane permeation rate according to the oxygen permeability, the proton exchange membrane thickness, the proton exchange membrane area and the cathode chamber pressure; The maximum permeation time for the amount of oxygen permeated from the cathode chamber to the anode chamber to reach the preset oxygen threshold is estimated according to the preset oxygen leakage rate, the preset oxygen threshold and the oxygen transmembrane permeation rate.

6. The fuel cell control method according to claim 5, characterized in that: The estimating the maximum permeation time for the amount of oxygen permeated from the cathode chamber to the anode chamber to reach the preset oxygen threshold value according to the preset oxygen leakage rate, the preset oxygen threshold value and the oxygen transmembrane permeation rate comprises: If the preset oxygen leakage rate is not less than the oxygen transmembrane permeation rate, determining the maximum permeation time according to the preset oxygen threshold and the oxygen transmembrane permeation rate; If the preset oxygen leakage is less than the oxygen transmembrane permeation rate, the maximum permeation time is determined according to the preset oxygen threshold and the preset oxygen leakage rate.

7. The fuel cell control method according to claim 1, characterized in that: Before obtaining the first measured parameter of the anode chamber and the second measured parameter of the cathode chamber of the fuel cell when the vehicle is powered off, the method includes: Get the vehicle power-off request; In response to the vehicle power-off request, the step of acquiring a first measured parameter of the anode chamber and a second measured parameter of the cathode chamber of the fuel cell is performed; based on the first measured parameter and the second measured parameter, a complete reaction time of the fuel in the anode chamber and a maximum permeation time for the amount of oxygen permeated from the cathode chamber to the anode chamber to reach a preset oxygen threshold are estimated; Determine the first purge time according to the complete reaction time and the maximum penetration time; The vehicle is controlled to enter a vehicle power-off state, and the anode cavity is purged when the vehicle power-off time reaches the first purge time.

8. A control device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the fuel cell control method according to any one of claims 1 to 7 is implemented.

9. A fuel cell system, characterized in that: comprising a fuel cell, a sensor assembly, a fuel circulation device and a control device as claimed in claim 8; The sensor assembly is connected to the fuel cell; The fuel circulation device is connected to the fuel cell; The control device is connected to the sensor assembly and the fuel circulation device.

10. A vehicle, characterized in that: Comprising the fuel cell system as claimed in claim 9.

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