Humidity control method and device of fuel cell air supply system and vehicle

Abstract

The invention relates to the technical field of fuel cells, in particular to a humidity control method and device of a fuel cell air supply system and a vehicle, and the method comprises the following steps: in the operation process of a fuel cell engine, obtaining the current impedance value of the fuel cell air supply system, the pressure difference of an electric pile inlet and outlet and the power of a hydrogen pump; and identifying the actual state of the stack according to the hydrogen pump power and the pressure difference between the inlet and the outlet of the stack, thereby matching the target humidity control action of the fuel cell air supply system according to the actual state and / or the current impedance value, and controlling the fuel cell air supply system to execute the target humidity control action. Therefore, the technical problems that in the related technology, the internal water content is judged only by impedance, so that the internal state of the galvanic pile cannot be accurately reflected, and faults such as film dryness and water logging are difficult to effectively deal with in time and the like are solved.

Description

Technical Field

[0001] The present application relates to the field of fuel cell technology, and in particular to a humidity control method, device and vehicle for a fuel cell air supply system. Background Art

[0002] In the related art, in the humidity control of the fuel cell air supply system, humidity increase is achieved through a membrane assembly. The membrane assembly uses special membrane materials, with high-humidity gas on one side and air to be humidified on the other side. The moisture is diffused through the humidity difference and gas partial pressure difference, thereby achieving air humidification.

[0003] However, in the related technology, air humidity is affected by many factors, forming a complex coupling system. In addition, the feedback accuracy of the humidity of the fuel cell stack is poor in actual operation, making it difficult to accurately adjust the humidity inside the fuel cell stack. The method of judging the internal water content based solely on impedance has limitations and cannot accurately reflect the internal state of the fuel cell stack. As a result, it is difficult to respond promptly and effectively to faults such as membrane drying and flooding, which in turn affects the normal operation and service life of the fuel cell stack.

[0004] In summary, in the relevant technologies, there are technical problems such as judging the internal water content only by impedance, which makes it impossible to accurately reflect the internal state of the fuel cell stack, resulting in difficulty in timely and effective response when faced with faults such as membrane drying and flooding, which need to be solved urgently. Summary of the invention

[0005] The present application provides a method, device and vehicle for controlling humidity of a fuel cell air supply system, in order to solve the problem in the related art that the internal water content is judged only by impedance, which makes it impossible to accurately reflect the internal state of the stack, resulting in difficulty in timely and effective response to faults such as membrane drying and flooding. The first aspect of the present application provides a method for controlling humidity of a fuel cell air supply system, comprising the following steps: during the operation of the fuel cell engine, obtaining the current impedance value, the inlet and outlet pressure difference of the stack and the hydrogen pump power of the fuel cell air supply system; identifying the actual state of the stack according to the hydrogen pump power and the inlet and outlet pressure difference of the stack; matching the target humidity control action of the fuel cell air supply system according to the actual state and / or the current impedance value, and controlling the fuel cell air supply system to perform the target humidity control action.

[0006] Through the above-mentioned technical scheme, the embodiment of the present application can identify the actual state of the fuel cell stack based on the hydrogen pump power and the pressure difference between the inlet and outlet of the fuel cell stack, so as to determine the target humidity control action using the actual state, or determine the target humidity control action using the actual state and the current impedance value, thereby effectively avoiding misjudgment, accurately identifying the actual state inside the fuel cell stack, and matching effective humidity control according to the actual state, reducing the probability of failure due to humidity problems, improving the reliability of the fuel cell air supply system, and effectively ensuring the performance and life of the fuel cell stack.

[0007] Optionally, in one embodiment of the present application, identifying the actual state of the fuel cell stack based on the current impedance value and the fuel cell stack inlet and outlet pressure difference includes: respectively determining the actual intervals of the current impedance value and the fuel cell stack inlet and outlet pressure difference; matching the actual state based on the current impedance value and the actual intervals of the fuel cell stack inlet and outlet pressure difference.

[0008] Through the above technical scheme, the embodiment of the present application can match the actual state by respectively determining the actual range of the current impedance value and the pressure difference at the inlet and outlet of the battery stack, thereby more accurately identifying the actual state of the battery stack, adapting to complex operating environments, and more accurately capturing changes in the state of the battery stack, providing an accurate basis for subsequent humidity control.

[0009] Optionally, in one embodiment of the present application, the target humidity control action of matching the fuel cell air supply system according to the actual state and / or the current impedance value includes: when the actual state is a flooded state, determining that the target humidity control action is a humidity control action that controls the bypass valve of the fuel cell air supply system to be fully open, the water pump speed is reduced to a first preset speed, and the three-way valve enters a preset small circulation operating condition.

[0010] Through the above technical scheme, the embodiment of the present application can accurately determine the target humidity control action when it is determined that the actual state is a flooded state. By controlling the bypass valve of the fuel cell air supply system to be fully open, most of the air entering the stack does not pass through the humidifier, and the humidity of the air entering the stack is directly reduced, thereby effectively improving the humidity environment inside the stack, restoring it from a flooded state to a normal state, improving the stability and reliability of the fuel cell system, and thus extending the service life of the stack.

[0011] Optionally, in one embodiment of the present application, the target humidity control action of matching the fuel cell air supply system according to the actual state and / or the current impedance value includes: when the actual state is a non-fault state, determining a feedforward control value of a bypass valve of the fuel cell air supply system in the target humidity control action based on the air inlet flow rate and air humidity of the fuel cell stack, and generating a current closed-loop control opening of the bypass valve based on the current impedance value.

[0012] Through the above technical scheme, the embodiment of the present application can comprehensively consider the air inflow rate and air humidity of the fuel cell stack when determining that the actual state is a non-fault state, and more accurately determine the opening of the bypass valve. At the same time, the current closed-loop control opening of the bypass valve is generated based on the current impedance value. The impedance value can reflect the humidity conditions inside the fuel cell stack. Through closed-loop control, the opening of the bypass valve can be adjusted in time according to the actual humidity feedback, thereby further improving the accuracy of humidity control.

[0013] Optionally, in one embodiment of the present application, the target humidity control action of matching the fuel cell air supply system according to the actual state and / or the current impedance value includes: when the actual state is a membrane dry state, determining that the target humidity control action is a humidity control action of controlling the bypass valve of the fuel cell air supply system to be fully closed, the water pump speed to be increased to a second preset speed, the three-way valve to enter a large circulation condition, and the fan speed to be increased to a third preset speed.

[0014] Through the above technical scheme, when the actual state is determined to be a membrane dry state, the embodiment of the present application can control the bypass valve of the fuel cell air supply system to be fully closed, so that all the air entering the stack passes through the humidifier, directly increasing the humidity of the air entering the stack, and restoring it from the membrane dry state to the normal state, thereby further improving the performance of the fuel cell and enhancing the durability and reliability of the stack.

[0015] Optionally, in one embodiment of the present application, the target humidity control action of matching the fuel cell air supply system according to the actual state and / or the current impedance value includes: when the actual state is a severe membrane dry state, determining the target humidity control action to be a humidity control action for controlling the bypass valve of the fuel cell air supply system to be fully closed to enter a shutdown purge condition.

[0016] Through the above technical scheme, when the actual state is determined to be a severe membrane dry state, the embodiment of the present application can control the bypass valve of the fuel cell air supply system to be fully closed and enter the shutdown purge condition, thereby cleaning and adjusting the inside of the stack, removing factors that may cause membrane dryness, creating good internal environmental conditions for the stack to resume normal operation, and improving the performance and stability of the stack after the stack resumes operation.

[0017] A second aspect of the present application provides a humidity control device for a fuel cell air supply system, including: an acquisition module, used to acquire the current impedance value, the stack inlet and outlet pressure difference and the hydrogen pump power of the fuel cell air supply system during the operation of the fuel cell engine; an identification module, used to identify the actual state of the fuel cell stack based on the hydrogen pump power and the stack inlet and outlet pressure difference; a control module, used to match the target humidity control action of the fuel cell air supply system according to the actual state and / or the current impedance value, and control the fuel cell air supply system to perform the target humidity control action.

[0018] Through the above-mentioned technical scheme, the embodiment of the present application can identify the actual state of the fuel cell stack based on the hydrogen pump power and the pressure difference between the inlet and outlet of the fuel cell stack, so as to determine the target humidity control action using the actual state, or determine the target humidity control action using the actual state and the current impedance value, thereby effectively avoiding misjudgment, accurately identifying the actual state inside the fuel cell stack, and matching effective humidity control according to the actual state, reducing the probability of failure due to humidity problems, improving the reliability of the fuel cell air supply system, and effectively ensuring the performance and life of the fuel cell stack.

[0019] Optionally, in one embodiment of the present application, the identification module includes: an interval determination unit, used to respectively determine the actual intervals of the current impedance value and the pressure difference at the inlet and outlet of the battery stack; and a matching unit, used to match the actual state according to the actual intervals of the current impedance value and the pressure difference at the inlet and outlet of the battery stack.

[0020] Through the above technical scheme, the embodiment of the present application can match the actual state by respectively determining the actual range of the current impedance value and the pressure difference at the inlet and outlet of the battery stack, thereby more accurately identifying the actual state of the battery stack, adapting to complex operating environments, and more accurately capturing changes in the state of the battery stack, providing an accurate basis for subsequent humidity control.

[0021] Optionally, in one embodiment of the present application, the control module includes: a first control unit, used to determine, when the actual state is a flooded state, that the target humidity control action is to control the bypass valve of the fuel cell air supply system to be fully open, the water pump speed to be reduced to a first preset speed, and the three-way valve to enter a preset small circulation operating condition.

[0022] Through the above technical scheme, the embodiment of the present application can accurately determine the target humidity control action when it is determined that the actual state is a flooded state. By controlling the bypass valve of the fuel cell air supply system to be fully open, most of the air entering the stack does not pass through the humidifier, and the humidity of the air entering the stack is directly reduced, thereby effectively improving the humidity environment inside the stack, restoring it from a flooded state to a normal state, improving the stability and reliability of the fuel cell system, and thus extending the service life of the stack.

[0023] Optionally, in one embodiment of the present application, the control module also includes: a second control unit, for determining a feedforward control value of a bypass valve of the fuel cell air supply system in the target humidity control action based on the air inlet flow rate and air humidity of the fuel cell stack when the actual state is a non-fault state, and generating a current closed-loop control opening of the bypass valve based on the current electrical impedance value.

[0024] Through the above technical scheme, the embodiment of the present application can comprehensively consider the air inflow rate and air humidity of the fuel cell stack when determining that the actual state is a non-fault state, and more accurately determine the opening of the bypass valve. At the same time, the current closed-loop control opening of the bypass valve is generated based on the current impedance value. The impedance value can reflect the humidity conditions inside the fuel cell stack. Through closed-loop control, the opening of the bypass valve can be adjusted in time according to the actual humidity feedback, thereby further improving the accuracy of humidity control.

[0025] Optionally, in one embodiment of the present application, the control module also includes: a third control unit, which is used to determine, when the actual state is a membrane dry state, that the target humidity control action is to control the bypass valve of the fuel cell air supply system to be fully closed, the water pump speed to be increased to a second preset speed, the three-way valve to enter a large circulation condition, and the fan speed to be increased to a third preset speed.

[0026] Through the above technical scheme, when the actual state is determined to be a membrane dry state, the embodiment of the present application can control the bypass valve of the fuel cell air supply system to be fully closed, so that all the air entering the stack passes through the humidifier, directly increasing the humidity of the air entering the stack, and restoring it from the membrane dry state to the normal state, thereby further improving the performance of the fuel cell and enhancing the durability and reliability of the stack.

[0027] Optionally, in one embodiment of the present application, the control module also includes: a fourth control unit, for determining, when the actual state is a severe membrane dry state, that the target humidity control action is a humidity control action of controlling the bypass valve of the fuel cell air supply system to be fully closed to enter a shutdown purge condition.

[0028] Through the above technical scheme, when the actual state is determined to be a severe membrane dry state, the embodiment of the present application can control the bypass valve of the fuel cell air supply system to be fully closed and enter the shutdown purge condition, thereby cleaning and adjusting the inside of the stack, removing factors that may cause membrane dryness, creating good internal environmental conditions for the stack to resume normal operation, and improving the performance and stability of the stack after the stack resumes operation.

[0029] 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 humidity control method of the fuel cell air supply system as described in the above embodiment.

[0030] A fourth aspect of the present application provides a computer-readable storage medium, which stores a computer program that, when executed by a processor, implements the above-mentioned humidity control method for a fuel cell air supply system.

[0031] The fifth aspect of the present application provides a computer program product, including a computer program, which, when executed, is used to implement the humidity control method of the fuel cell air supply system as described above.

[0032] The embodiment of the present application can more accurately identify the actual state of the stack, adapt to complex operating environments, capture state changes, and provide accurate basis for humidity control by monitoring multiple parameters including but not limited to impedance value and stack inlet and outlet pressure difference. When the stack is identified as being in a flooded state, a precise humidity control action is implemented, that is, the bypass valve is fully opened to allow most of the air to bypass the humidifier, directly reduce the humidity of the air entering the stack, effectively improve the humidity environment inside the stack, and promote it to return to a normal state; in a non-fault state, the air inlet flow and air humidity are comprehensively considered to accurately determine the bypass valve opening. At the same time, a closed-loop control opening is generated based on the impedance value, and is adjusted in time according to actual humidity feedback, thereby improving the humidity control accuracy; when a membrane dry state is detected, the bypass valve is fully closed to allow all the air entering the stack to pass through the humidifier, directly increase the air humidity, and promote the stack to return from a membrane dry state to a normal state; for a serious membrane dry state, the bypass valve is controlled to be fully closed and enter the shutdown purge condition, the inside of the stack is cleaned and adjusted, the membrane dry factor is removed, and good internal conditions are created for the stack to resume normal operation, thereby improving subsequent operating performance and stability. In summary, through multi-parameter monitoring and status identification, the embodiment of the present application can accurately implement humidity control actions according to the actual state of the fuel cell stack, effectively deal with conditions such as flooding and membrane drying, improve the operating reliability and efficiency of the fuel cell air supply system, and thus extend the service life of the fuel cell stack.

[0033] 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

[0034] 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:

[0035] Figure 1 A schematic diagram of the structure of an air circuit and a cooling water circuit of a fuel cell air supply system according to an embodiment of the present application;

[0036] Figure 2 A flow chart of a humidity control method for a fuel cell air supply system provided according to an embodiment of the present application;

[0037] Figure 3 is a flow chart of a humidity control method for a fuel cell air supply system according to a specific embodiment of the present application;

[0038] Figure 4A schematic structural diagram of a humidity control device for a fuel cell air supply system provided in an embodiment of the present application;

[0039] Figure 5 This is an example diagram of the structure of a vehicle provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0040] 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.

[0041] The humidity control method, device and vehicle of the fuel cell air supply system of the embodiment of the present application are described below with reference to the accompanying drawings. In view of the technical problems such as the related technology mentioned in the background technology center that the internal water content is judged only by impedance, which makes it impossible to accurately reflect the internal state of the stack, resulting in difficulty in timely and effective response to faults such as membrane drying and flooding, the present application provides a humidity control method for a fuel cell air supply system. In this method, when the fuel cell engine is running, the current impedance value, the inlet and outlet pressure difference of the stack and the hydrogen pump power can be obtained, and the actual state of the stack can be identified based on the hydrogen pump power and the inlet and outlet pressure difference of the stack, such as normal, flooded, membrane dry, severe membrane dry, etc., so as to match the target humidity control action according to different states, improve the control accuracy of humidity, maintain a suitable environment for the stack, enhance the reliability of the fuel cell air supply system, and extend the service life of the stack. Thus, the problems in the related technology are solved.

[0042] Since the internal water content is judged only by impedance, it is impossible to accurately reflect the internal state of the fuel cell stack, resulting in technical problems such as difficulty in timely and effective response to faults such as membrane drying and flooding.

[0043] In order to better understand the humidity control method of the fuel cell air supply system proposed in the embodiment of the present application, it is necessary to first have a clear understanding of the structure of the fuel cell air supply system, such as Figure 1 As shown, Figure 1 Only the air path and cooling water path of the fuel cell air supply system involved in the embodiment of the present application are shown.

[0044] Among them, the fuel cell air path is composed of an air filter 1, an air compressor 2, a humidifier 3 and a bypass valve 4 of the humidifier. The humidifier 3 is a membrane humidifier, which humidifies the air entering the stack by taking the humidity from the air leaving the stack. The larger the opening of the bypass valve 4, the lower the humidity of the air entering the stack. When the bypass valve 4 is fully opened, part of the air does not pass through the humidifier 3, so that the humidity of the air entering the stack is relatively low. When the bypass valve 4 is fully closed, all the air passes through the humidifier 3, so that the humidity of the air entering the stack is relatively high.

[0045] The fuel cell cooling water circuit is composed of a water pump 5, a three-way valve 6 and a radiator 7. The faster the speed of the water pump 5, the larger the opening of the three-way valve 6, the faster the fan speed of the radiator 7, and the better the heat dissipation of the stack. When the three-way valve is fully opened, all the cooling water passes through the radiator 7, and the heat dissipation effect is better; when the three-way valve 6 is fully closed, all the cooling water does not pass through the radiator 7, and the heat dissipation effect is poor.

[0046] Specifically, Figure 2 A schematic flow chart of a humidity control method for a fuel cell air supply system provided in an embodiment of the present application.

[0047] like Figure 1 As shown, the humidity control method of the fuel cell air supply system includes the following steps:

[0048] In step S101, during the operation of the fuel cell engine, the current impedance value of the fuel cell air supply system, the stack inlet and outlet pressure difference, and the hydrogen pump power are obtained.

[0049] It can be understood that the current impedance value refers to the resistance characteristics of the stack at a certain moment. In a fuel cell, the impedance value can reflect its internal state, especially the moisture content of the electrolyte layer, the catalyst activity and other factors affecting the flow of current; the stack inlet and outlet pressure difference refers to the pressure difference between the outlet and inlet of the fuel cell stack. This pressure difference reflects the resistance encountered by air or hydrogen when flowing through the stack, and can be used to evaluate the smoothness of air flow and the blockage condition inside the stack; the hydrogen pump power is used to transport hydrogen to the fuel cell stack, and its power determines the hydrogen supply rate and the working capacity of the stack.

[0050] In the actual implementation process, when the fuel cell engine is in operation, the impedance value at the current moment, the pressure difference between the inlet and outlet of the fuel cell stack, and the hydrogen pump power are obtained through corresponding monitoring equipment and technical means. The impedance value can be obtained by measuring with a high-frequency impedance analyzer, which applies a high-frequency AC signal to the fuel cell stack and measures the response of the fuel cell stack to the signal, thereby calculating the high-frequency impedance value of the fuel cell stack. This measurement method can accurately reflect the conductive properties inside the fuel cell stack and the influence of humidity on it.

[0051] Furthermore, in order to obtain the pressure difference between the inlet and outlet of the fuel cell stack, a high-precision differential pressure sensor can be installed at the inlet and outlet of the fuel cell stack respectively. The differential pressure sensor works based on the piezoresistive effect or capacitive principle. When there is a pressure difference between the inlet and outlet of the fuel cell stack, the sensitive element inside the sensor will undergo corresponding deformation or capacitance change, and then convert the pressure difference into an electrical signal for output, thereby monitoring and recording the pressure difference between the two in real time.

[0052] Furthermore, the power of the hydrogen pump can be obtained with the help of a power analyzer. The power analyzer measures the voltage and current of the hydrogen pump and uses the power calculation formula (power = voltage × current) to calculate the actual power value of the hydrogen pump. In terms of connection method, the power analyzer is correctly connected to the circuit of the hydrogen pump to ensure that the actual power value of the hydrogen pump during operation can be accurately obtained.

[0053] The embodiment of the present application can fully understand the state of the fuel cell during operation by obtaining the three key parameters of the current impedance value of the fuel cell air supply system, the pressure difference between the inlet and outlet of the fuel cell stack, and the hydrogen pump power. Different parameters reflect the performance and problems of different aspects of the fuel cell, providing rich data support for accurate diagnosis of the working status of the fuel cell.

[0054] In step S102, the actual state of the fuel cell stack is identified based on the hydrogen pump power and the pressure difference between the fuel cell stack inlet and outlet.

[0055] It is understandable that the actual state of the stack refers to the actual situation of the stack during operation, including normal state, flooded state, membrane dry state, severe membrane dry state, etc. The actual state of the stack is related to factors such as humidity, temperature, gas flow, and chemical reaction rate inside the stack. By monitoring parameters such as hydrogen pump power and stack inlet and outlet pressure difference, the actual state of the stack can be identified so that corresponding control measures can be taken to ensure the normal operation of the fuel cell.

[0056] Optionally, in one embodiment of the present application, the actual state of the fuel cell stack is identified based on the current impedance value and the pressure difference at the inlet and outlet of the fuel cell stack, including: respectively determining the actual intervals of the current impedance value and the pressure difference at the inlet and outlet of the fuel cell stack; and matching the actual state based on the current impedance value and the actual intervals of the pressure difference at the inlet and outlet of the fuel cell stack.

[0057] Specifically, when the hydrogen pump power is less than the first power and the pressure difference between the inlet and outlet of the fuel cell stack is less than the first pressure difference, the humidity inside the fuel cell stack is in a flooded state; when the hydrogen pump power is greater than the first power and less than the second power, and the pressure difference between the inlet and outlet of the fuel cell stack is greater than the first pressure difference and less than the second pressure difference, the humidity inside the fuel cell stack is in a normal state; when the hydrogen pump power is greater than the second power and the pressure difference between the inlet and outlet of the fuel cell stack is greater than the second pressure difference, the humidity inside the fuel cell stack is in a membrane dry state; when the hydrogen pump power is greater than the third power and the pressure difference between the inlet and outlet of the fuel cell stack is greater than the third pressure difference, the humidity inside the fuel cell stack is in a severe membrane dry state.

[0058] The embodiment of the present application can match the actual state according to the actual interval of the current impedance value and the pressure difference between the inlet and outlet of the fuel cell stack, distinguish different fault states of the fuel cell stack, provide a clear basis for subsequent targeted control measures, and improve the reliability and stability of the system.

[0059] In step S103, the target humidity control action of the fuel cell air supply system is matched according to the actual state and / or the current impedance value, and the fuel cell air supply system is controlled to perform the target humidity control action.

[0060] It is understandable that the target humidity control action is a humidity control operation for the fuel cell air supply system determined according to the actual state of the fuel cell stack and / or the current impedance value. For example, in a flooded state, the target humidity control action may be to control the bypass valve to be fully opened, the water pump speed to be reduced, the three-way valve to enter a small cycle, etc.

[0061] In some embodiments, the target humidity control action of the fuel cell air supply system is matched according to the actual state and / or the current impedance value, including: when the actual state is a flooded state, determining the target humidity control action to be a humidity control action to control the bypass valve of the fuel cell air supply system to be fully open, the water pump speed to be reduced to a first preset speed, and the three-way valve to enter a preset small circulation operating condition.

[0062] In the actual implementation process, based on the analysis results of relevant parameters such as hydrogen pump power and stack inlet and outlet pressure difference, it is determined that the stack is in a flooded state, that is, the humidity inside the stack is too high, and it is necessary to reduce the moisture brought in by the air to alleviate the flooding situation. For the bypass valve in the fuel cell air supply system, its control action is determined to be fully open, and most of the air entering the stack will not pass through the humidifier, thereby directly reducing the humidity of the air entering the stack; for the water pump, its speed is reduced to the first speed to reduce the circulation of cooling water. The reduction in the circulation of cooling water will gradually increase the temperature of the stack, and the increase in temperature will help the evaporation of moisture inside the stack, thereby further improving the flooding situation; for the three-way valve, it is determined that it enters the small circulation condition. After the three-way valve enters the small circulation condition, the working mode of the entire cooling system will change, and the path and flow of the cooling water can be more effectively adjusted. Cooperating with the control actions of the bypass valve and the water pump, they jointly create favorable conditions for alleviating the flooding state, so that the humidity inside the stack can be restored to a suitable level as soon as possible.

[0063] In other embodiments, the target humidity control action of the fuel cell air supply system is matched according to the actual state and / or the current impedance value, including: when the actual state is a non-fault state, the feedforward control value of the bypass valve of the fuel cell air supply system in the target humidity control action is determined based on the air inlet flow rate and air humidity of the fuel cell stack, and the current closed-loop control opening of the bypass valve is generated based on the current electrical impedance value.

[0064] Specifically, when the air flow rate into the stack is large and the air humidity is high, in order to avoid excessive humidity inside the fuel cell stack, the opening of the bypass valve is appropriately increased, that is, the feedforward control value is increased, so that part of the air can enter the fuel cell stack directly without passing through the humidifier, thereby adjusting the humidity of the air entering the stack; conversely, when the air flow rate into the stack is small and the air humidity is low, in order to prevent the humidity inside the fuel cell stack from being too low, it is necessary to appropriately reduce the opening of the bypass valve, that is, reduce the feedforward control value, so that more air can pass through the humidifier to increase the humidity of the air entering the stack.

[0065] Furthermore, the current closed-loop control opening of the bypass valve is generated based on the current electrical impedance value. The current electrical impedance value, such as the high-frequency electrical impedance value, can reflect the humidity inside the fuel cell stack. When the high-frequency electrical impedance value changes, it means that the humidity inside the fuel cell stack has changed. Through the closed-loop control mechanism, the high-frequency electrical impedance value is used as a feedback signal to adjust the opening of the bypass valve in real time according to its changes. For example, when the high-frequency electrical impedance value increases, it indicates that the humidity inside the fuel cell stack may decrease. At this time, the opening of the bypass valve should be appropriately reduced to increase the humidity of the air entering the stack; when the high-frequency electrical impedance value decreases, it indicates that the humidity inside the fuel cell stack may increase. At this time, the opening of the bypass valve should be appropriately increased to reduce the humidity of the air entering the stack. Through this closed-loop control method, the opening of the bypass valve can be controlled more accurately, and then the humidity of the air entering the stack can be more effectively adjusted to maintain the humidity balance inside the fuel cell stack.

[0066] In some cases, the target humidity control action of the fuel cell air supply system is matched according to the actual state and / or the current impedance value, including: when the actual state is a membrane dry state, determining the target humidity control action to be a humidity control action to control the bypass valve of the fuel cell air supply system to be fully closed, the water pump speed to be increased to a second preset speed, the three-way valve to enter a large circulation condition, and the fan speed to be increased to a third preset speed.

[0067] In the embodiment of the present application, when it is determined that the actual state of the fuel cell stack is a membrane dry state, the bypass valve in the fuel cell air supply system is controlled to be fully closed. This is because in the membrane dry state, the humidity inside the fuel cell stack is seriously insufficient, and all the air entering the stack needs to pass through a humidifier to increase the humidity. Therefore, the bypass valve is closed to ensure that no unhumidified air enters the fuel cell stack. For the water pump, its speed is increased to the second speed. This is because increasing the water pump speed can increase the circulation amount of cooling water. As the circulation amount of cooling water increases, the temperature of the fuel cell stack will decrease, which will help reduce the evaporation of water inside the fuel cell stack and alleviate the membrane. Dry situation; for the three-way valve, determine that it enters the large circulation condition. After the three-way valve enters the large circulation condition, the working mode of the cooling system changes, allowing the cooling water to flow through a wider area, effectively adjusting the temperature of the fuel cell stack, and coordinating with the control actions of the bypass valve and the water pump to jointly improve the membrane dry condition, so that the humidity inside the fuel cell stack can be restored to an appropriate level as soon as possible; for the fan, increase its speed to the third speed. Increasing the fan speed can speed up the heat dissipation speed, further reduce the temperature of the fuel cell stack, thereby reducing the evaporation of water, assisting in alleviating the membrane dry state, and ensuring that the humidity inside the fuel cell stack can gradually return to normal.

[0068] In other cases, the target humidity control action of the fuel cell air supply system is matched according to the actual state and / or the current impedance value, including: when the actual state is a severe membrane dry state, determining the target humidity control action as a humidity control action to control the bypass valve of the fuel cell air supply system to be fully closed to enter a shutdown purge condition.

[0069] On the one hand, in the case of severe membrane dryness, the bypass valve of the fuel cell air supply system is controlled to be fully closed. This is because the humidity inside the stack is extremely scarce in the severe membrane dryness state. Specifically, in order to restore the humidity environment inside the stack as soon as possible, it is necessary to ensure that all the air entering the stack passes through the humidifier, and the bypass valve can achieve this goal, so that all the air entering the stack can be processed by the humidifier, thereby maximizing the humidity of the air entering the stack.

[0070] On the other hand, by controlling the bypass valve of the fuel cell air supply system to be fully closed, the system enters the shutdown and purge condition. Specifically, shutdown can prevent the stack from continuing to operate in a serious membrane dry state and suffering more serious damage, and prevent key components such as membrane electrodes from being irreversibly damaged due to excessive drying. In addition, the purge operation can remove factors that may cause membrane dryness, such as exhausting residual dry air inside the stack, and create good internal environmental conditions for subsequent resumption of normal operation.

[0071] The above preset parameters can be obtained by, including but not limited to, experimental tests and / or theoretical calculations.

[0072] In order to better understand the humidity control method of the fuel cell air supply system proposed in the embodiment of the present application, the following is a description in conjunction with a specific embodiment. Figure 3 As shown, the humidity control principle of the fuel cell air supply system is as follows:

[0073] Step S301: Start.

[0074] The fuel cell starts running.

[0075] Step S302: Monitor the hydrogen pump power W ARB , the pressure difference ΔP at the inlet and outlet of the fuel cell stack and the high-frequency impedance value HFR.

[0076] Step S303: ARB <W1,ΔP<ΔP1.

[0077] If the hydrogen pump power is less than the first power and the pressure difference between the inlet and outlet of the fuel cell stack is less than the first pressure difference, step S304 is executed.

[0078] Step S304: the humidity inside the fuel cell stack is in a flooded state.

[0079] According to the hydrogen pump power and the pressure difference between the inlet and outlet of the fuel cell stack, it is determined that the current state inside the fuel cell stack is flooded.

[0080] Step S305: The bypass valve is fully opened, the water pump speed is reduced, and the three-way valve enters a small cycle.

[0081] The bypass valve is fully opened, so that most of the air entering the stack does not pass through the humidifier. The water pump speed is reduced and the three-way valve enters a small cycle, which increases the temperature of the stack until it is out of the flooding state.

[0082] Step S306: W1<W ARB <W2,ΔP1<ΔP<ΔP2.

[0083] If the hydrogen pump power is less than the second power and greater than the first power, and the pressure difference between the inlet and outlet of the fuel cell stack is less than the second pressure difference and greater than the first pressure difference, step S307 is executed.

[0084] Step S307: The humidity inside the fuel cell stack is not in a fault state.

[0085] The current state inside the fuel cell stack is determined to be normal based on the hydrogen pump power and the pressure difference between the fuel cell stack inlet and outlet.

[0086] Step S308: Based on the HFR, the opening of the bypass valve is closed-loop controlled.

[0087] Through the closed-loop control mechanism, the high-frequency electrical impedance value is used as a feedback signal, and the opening of the bypass valve is adjusted in real time according to its changes.

[0088] Step S309: W ARB>W2,ΔP>ΔP2.

[0089] If the hydrogen pump power is greater than the second power and the pressure difference between the inlet and outlet of the fuel cell stack is greater than the second pressure difference, step S310 is executed.

[0090] Step S310: The humidity inside the fuel cell stack is in a membrane dry state.

[0091] According to the hydrogen pump power and the pressure difference between the inlet and outlet of the fuel cell stack, it is determined that the current state inside the fuel cell stack is in a membrane dry state.

[0092] Step S311: The bypass valve is fully closed, the water pump speed increases, the three-way valve enters a large cycle, and the fan speed increases.

[0093] The bypass valve is fully closed, so that all the air entering the stack passes through the humidifier, the water pump speed increases, the three-way valve enters a large circulation, the fan speed increases, and the temperature of the stack is reduced until it leaves the membrane dry state.

[0094] Step S312: ARB >W3,ΔP>ΔP3.

[0095] If the hydrogen pump power is greater than the third power and the pressure difference between the inlet and outlet of the fuel cell stack is greater than the third pressure difference, step S313 is executed.

[0096] Step S313: The humidity inside the fuel cell stack is in a serious membrane dry state.

[0097] According to the hydrogen pump power and the pressure difference between the inlet and outlet of the fuel cell stack, it is determined that the current state inside the fuel cell stack is in a serious membrane dry state.

[0098] Step S314: The bypass valve is fully closed and the machine is shut down for purging.

[0099] By controlling the bypass valve of the fuel cell air supply system to be fully closed, the system enters a shutdown and purge condition, preventing the stack from continuing to operate in a severe membrane dry state and suffering more serious damage, and removing factors that may cause membrane dryness.

[0100] According to this embodiment, during the operation of the fuel cell engine, the current impedance value, hydrogen pump power, and stack inlet and outlet pressure difference are obtained, and the internal humidity of the stack is judged to be in a normal state or a fault state according to the values ​​of the hydrogen pump power and the stack inlet and outlet pressure difference. If the stack humidity is in a normal state, the opening of the bypass valve is closed-loop controlled based on the impedance value; if it is in a flooded state, the bypass valve is fully opened so that most of the air entering the stack does not pass through the humidifier; the water pump speed is reduced and the three-way valve enters a small cycle to increase the temperature of the stack until it is out of the flooded state; if the stack humidity is not in a faulty state, the air inlet flow rate and the air humidity are compared. The bypass valve is feedforward controlled, and the opening of the bypass valve is closed-loop controlled based on the electrical impedance value. If the membrane is detected to be in a dry state, the bypass valve is fully closed to allow all the air entering the stack to pass through the humidifier. The water pump speed increases, the three-way valve enters a large cycle, and the fan speed increases to reduce the temperature of the stack until it is out of the membrane dry state. The bypass valve is feedforward controlled based on the air inlet flow rate and air humidity, and the opening of the bypass valve is closed-loop controlled based on the electrical impedance value. If a severe membrane dry state is detected, the bypass valve is fully closed and the system enters a shutdown purge until it is out of the severe membrane dry state, and then control is performed according to the strategy for the membrane dry state.

[0101] According to the humidity control method of the fuel cell air supply system proposed in the embodiment of the present application, the current impedance value, the inlet and outlet pressure difference of the fuel cell stack and the hydrogen pump power can be obtained when the fuel cell engine is running, and the actual state of the fuel cell stack can be identified based on the hydrogen pump power and the inlet and outlet pressure difference of the fuel cell stack, such as normal, flooded, membrane dry, severe membrane dry, etc., so as to match the target humidity control action according to different states, improve the control accuracy of the humidity, maintain a suitable environment for the fuel cell stack, enhance the reliability of the fuel cell air supply system, and extend the service life of the fuel cell stack.

[0102] Next, the humidity control device of the fuel cell air supply system proposed in the embodiment of the present application is described with reference to the accompanying drawings.

[0103] Figure 4 4 is a block diagram of a humidity control device of a fuel cell air supply system according to an embodiment of the present application.

[0104] like Figure 4 As shown, the humidity control device 10 of the fuel cell air supply system includes: an acquisition module 100 , an identification module 200 and a control module 300 .

[0105] Specifically, the acquisition module 100 is used to acquire the current impedance value of the fuel cell air supply system, the pressure difference between the inlet and outlet of the fuel cell stack, and the hydrogen pump power during the operation of the fuel cell engine.

[0106] The identification module 200 is used to identify the actual state of the fuel cell stack according to the hydrogen pump power and the pressure difference between the fuel cell stack inlet and outlet.

[0107] The control module 300 is used to match the target humidity control action of the fuel cell air supply system according to the actual state and / or the current impedance value, and control the fuel cell air supply system to perform the target humidity control action.

[0108] Optionally, in one embodiment of the present application, the identification module 200 includes: an interval determination unit and a matching unit.

[0109] Among them, the interval determination unit is used to determine the actual intervals of the current impedance value and the pressure difference between the inlet and outlet of the fuel cell stack.

[0110] The matching unit is used to match the actual state according to the actual range of the current impedance value and the pressure difference between the inlet and outlet of the fuel cell stack.

[0111] Optionally, in one embodiment of the present application, the control module 300 includes: a first control unit, which is used to determine, when the actual state is a flooded state, a target humidity control action, which is a humidity control action to control the bypass valve of the fuel cell air supply system to be fully opened, the water pump speed to be reduced to a first preset speed, and the three-way valve to enter a preset small circulation operating condition.

[0112] Optionally, in one embodiment of the present application, the control module 300 also includes: a second control unit, which is used to determine the feedforward control value of the bypass valve of the fuel cell air supply system in the target humidity control action based on the air inlet flow rate and air humidity of the fuel cell stack when the actual state is a non-fault state, and generate the current closed-loop control opening of the bypass valve based on the current electrical impedance value.

[0113] Optionally, in one embodiment of the present application, the control module 300 also includes: a third control unit, which is used to determine, when the actual state is a membrane dry state, a target humidity control action as controlling the bypass valve of the fuel cell air supply system to be fully closed, the water pump speed to be increased to a second preset speed, the three-way valve to enter a large circulation condition, and the fan speed to be increased to a third preset speed.

[0114] Optionally, in one embodiment of the present application, the control module 300 also includes: a fourth control unit, which is used to determine the target humidity control action as a humidity control action to control the bypass valve of the fuel cell air supply system to be fully closed to enter a shutdown purge condition when the actual state is a severe membrane dry state.

[0115] It should be noted that the above explanation of the embodiment of the humidity control method of the fuel cell air supply system is also applicable to the humidity control device of the fuel cell air supply system of this embodiment, and will not be repeated here.

[0116] According to the humidity control device of the fuel cell air supply system proposed in the embodiment of the present application, the current impedance value, the pressure difference between the inlet and outlet of the fuel cell stack and the hydrogen pump power can be obtained when the fuel cell engine is running, and the actual state of the fuel cell stack can be identified based on the hydrogen pump power and the pressure difference between the inlet and outlet of the fuel cell stack, such as normal, flooded, membrane dry, severe membrane dry, etc., so as to match the target humidity control action according to different states, improve the control accuracy of the humidity, maintain a suitable environment for the fuel cell stack, enhance the reliability of the fuel cell air supply system, and extend the service life of the fuel cell stack.

[0117] Figure 5 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application. The vehicle may include:

[0118] A memory 501 , a processor 502 , and a computer program stored in the memory 501 and executable on the processor 502 .

[0119] When the processor 502 executes the program, the humidity control method of the fuel cell air supply system provided in the above embodiment is implemented.

[0120] Furthermore, the vehicle also includes:

[0121] The communication interface 503 is used for communication between the memory 501 and the processor 502 .

[0122] The memory 501 is used to store computer programs that can be executed on the processor 502 .

[0123] The memory 501 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0124] 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 Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. 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.

[0125] 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.

[0126] The processor 502 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0127] An embodiment of the present application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the humidity control method for the fuel cell air supply system as described above.

[0128] An embodiment of the present application also provides a computer program product, including a computer program, which, when executed, is used to implement the humidity control method for the fuel cell air supply system as described above.

[0129] 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 do not necessarily refer 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.

[0130] 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.

[0131] 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.

[0132] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways as necessary and then storing it in a computer memory.

[0133] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. If implemented by 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 for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0134] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0135] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0136] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. 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 limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A humidity control method for a fuel cell air supply system, characterized in that: The following steps are involved: During the operation of the fuel cell engine, the current impedance value of the fuel cell air supply system, the pressure difference between the inlet and outlet of the fuel cell stack, and the power of the hydrogen pump are obtained; Identify the actual state of the fuel cell stack according to the hydrogen pump power and the fuel cell stack inlet and outlet pressure difference; A target humidity control action of the fuel cell air supply system is matched according to the actual state and / or the current impedance value, and the fuel cell air supply system is controlled to perform the target humidity control action.

2. The method according to claim 1, characterized in that The identifying the actual state of the fuel cell stack according to the hydrogen pump power and the fuel cell stack inlet and outlet pressure difference comprises: Determining respectively the actual ranges of the hydrogen pump power and the pressure difference between the inlet and outlet of the fuel cell stack; The actual state is matched according to the actual interval of the hydrogen pump power and the pressure difference between the inlet and outlet of the fuel cell stack.

3. The method according to claim 1, characterized in that The target humidity control action of matching the fuel cell air supply system according to the actual state and / or the current impedance value comprises: When the actual state is a flooded state, the target humidity control action is determined to be a humidity control action that controls the bypass valve of the fuel cell air supply system to be fully opened, the water pump speed to be reduced to a first preset speed, and the three-way valve to enter a preset small circulation working condition.

4. The method according to claim 1, characterized in that: The target humidity control action of matching the fuel cell air supply system according to the actual state and / or the current impedance value comprises: When the actual state is a non-fault state, the feedforward control value of the bypass valve of the fuel cell air supply system in the target humidity control action is determined based on the air inlet flow rate and air humidity of the fuel cell stack, and the current closed-loop control opening of the bypass valve is generated based on the current electrical impedance value.

5. The method according to claim 1, characterized in that The target humidity control action of matching the fuel cell air supply system according to the actual state and / or the current impedance value comprises: When the actual state is a membrane dry state, the target humidity control action is determined to be a humidity control action that controls the bypass valve of the fuel cell air supply system to be fully closed, the water pump speed to be increased to a second preset speed, the three-way valve to enter a large circulation condition, and the fan speed to be increased to a third preset speed.

6. The method according to claim 1, characterized in that The target humidity control action of matching the fuel cell air supply system according to the actual state and / or the current impedance value comprises: In the case where the actual state is a severe membrane dry state, the target humidity control action is determined to be a humidity control action of controlling the bypass valve of the fuel cell air supply system to be fully closed to enter a shutdown purge condition.

7. A humidity control device for a fuel cell air supply system, characterized in that: include: An acquisition module is used to acquire the current impedance value of the fuel cell air supply system, the pressure difference between the inlet and outlet of the fuel cell stack, and the power of the hydrogen pump during the operation of the fuel cell engine; An identification module, used to identify the actual state of the fuel cell stack according to the hydrogen pump power and the pressure difference between the fuel cell stack inlet and outlet; A control module is used to match a target humidity control action of the fuel cell air supply system according to the actual state and / or the current impedance value, and control the fuel cell air supply system to perform the target humidity control action.

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 humidity control method for the fuel cell air supply system according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the humidity control method of the fuel cell air supply system according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that The computer program is executed to implement the humidity control method of the fuel cell air supply system according to any one of claims 1 to 6.

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