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

Abstract

The application 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, wherein the method comprises the following steps: in the process of operation of a fuel cell engine, obtaining a current impedance value of a fuel cell air supply system, a pressure difference between an inlet and an outlet of a stack and a hydrogen pump power, identifying an actual state of the stack according to the hydrogen pump power and the pressure difference between the inlet and the outlet of the stack, matching a 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 problem that in the prior art, the internal water content is determined only by the impedance, the internal state of the stack cannot be accurately reflected, and the stack cannot be effectively responded to in a timely manner when facing faults such as membrane dryness and water flooding is solved.

Description

Technical Field

[0001] This 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 Technology

[0002] In related technologies, humidity control in fuel cell air supply systems is achieved through membrane modules. These modules utilize special membrane materials, with one side containing high-humidity gas and the other side containing air to be humidified. The moisture diffuses through the humidity difference and gas partial pressure difference, thereby achieving air humidification.

[0003] However, in related technologies, air humidity is affected by a variety of factors, forming a complex coupling system. In addition, the feedback accuracy of fuel cell stack humidity is poor in actual operation, making it difficult to accurately adjust the internal humidity of 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 in a timely and effective manner when facing faults such as membrane dryness and water flooding, which in turn affects the normal operation and service life of the fuel cell stack.

[0004] In summary, the relevant technologies suffer from several problems, such as the inability to accurately reflect the internal state of the fuel cell stack due to relying solely on impedance to determine the internal water content. This makes it difficult to respond promptly and effectively to faults such as membrane dryness and flooding. These issues urgently need to be addressed. Summary of the Invention

[0005] This application provides a humidity control method, apparatus, and vehicle for a fuel cell air supply system to address the problems in related technologies where relying solely on impedance to determine internal water content fails to accurately reflect the internal state of the fuel cell stack, leading to difficulties in timely and effective responses to faults such as membrane dryness and flooding. A first aspect of this application provides a humidity control method for a fuel cell air supply system, comprising the following steps: during fuel cell engine operation, acquiring the current impedance value of the fuel cell air supply system, the pressure difference between the fuel cell stack inlet and outlet, and the hydrogen pump power; identifying the actual state of the fuel cell stack based on the hydrogen pump power and the pressure difference between the fuel cell stack inlet and outlet; matching a target humidity control action of the fuel cell air supply system based on the actual state and / or the current impedance value, and controlling the fuel cell air supply system to execute the target humidity control action.

[0006] Through the above technical solutions, the embodiments of this application can identify the actual state of the fuel cell stack based on the hydrogen pump power and the pressure difference between the stack inlet and outlet, thereby determining the target humidity control action using the actual state, or determining 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 lifespan of the fuel cell stack.

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

[0008] Through the above technical solution, the embodiments of this application can match the actual state by determining the current impedance value and the actual range of the voltage difference between the inlet and outlet of the fuel cell stack, thereby more accurately identifying the actual state of the fuel cell stack, adapting to complex operating environments, and more accurately capturing changes in the state of the fuel cell stack, providing an accurate basis for subsequent humidity control.

[0009] Optionally, in one embodiment of this application, the step of matching the target humidity control action of 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 the target humidity control action as a humidity control action that controls 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 condition.

[0010] Through the above technical solution, the embodiments of this application can accurately determine the target humidity control action when the actual state is determined to be a flooded state. By controlling the bypass valve of the fuel cell air supply system to be fully opened, most of the incoming air does not pass through the humidifier, directly reducing the humidity of the incoming air, effectively improving the humidity environment inside the fuel cell 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 fuel cell stack.

[0011] Optionally, in one embodiment of this application, the step of matching the target humidity control action of 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 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, and generating the current closed-loop control opening of the bypass valve based on the current impedance value.

[0012] Through the above technical solution, the embodiments of this application can more accurately determine the opening degree of the bypass valve by comprehensively considering the air inflow rate and air humidity of the fuel cell stack when the actual state is determined to be a non-fault state. At the same time, the current closed-loop control opening degree of the bypass valve is generated based on the current impedance value. The impedance value can reflect the humidity situation inside the fuel cell stack. Through closed-loop control, the opening degree of the bypass valve can be adjusted in a timely manner according to the actual humidity feedback, further improving the accuracy of humidity control.

[0013] Optionally, in one embodiment of this application, the step of matching the target humidity control action of 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 the target humidity control action as 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 the large circulation mode, and the fan speed to be increased to a third preset speed.

[0014] Through the above technical solution, the embodiments of this application can, when the actual state is determined to be membrane dry, 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, restoring it from the membrane dry state to the normal state, further improving the performance of the fuel cell, and enhancing the durability and reliability of the stack.

[0015] Optionally, in one embodiment of this application, the step of matching the target humidity control action of 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 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 closed to enter the shutdown purging condition.

[0016] Through the above technical solution, the embodiments of this application can, when the actual state is determined to be a severe membrane dry state, control the bypass valve of the fuel cell air supply system to be fully closed and enter the shutdown purging state to clean and adjust the inside of the fuel cell stack, remove factors that may cause membrane dryness, create good internal environmental conditions for the fuel cell stack to resume normal operation, and improve the performance and stability of the fuel cell stack after it resumes operation.

[0017] A second aspect of this application provides a humidity control device for a fuel cell air supply system, comprising: an acquisition module for acquiring the current impedance value, stack inlet-outlet pressure difference, and hydrogen pump power of the fuel cell air supply system during fuel cell engine operation; an identification module for identifying the actual state of the fuel cell stack based on the hydrogen pump power and the stack inlet-outlet pressure difference; and a control module for matching a target humidity control action of the fuel cell air supply system based on the actual state and / or the current impedance value, and controlling the fuel cell air supply system to execute the target humidity control action.

[0018] Through the above technical solutions, the embodiments of this application can identify the actual state of the fuel cell stack based on the hydrogen pump power and the pressure difference between the stack inlet and outlet, thereby determining the target humidity control action using the actual state, or determining 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 lifespan of the fuel cell stack.

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

[0020] Through the above technical solution, the embodiments of this application can match the actual state by determining the current impedance value and the actual range of the voltage difference between the inlet and outlet of the fuel cell stack, thereby more accurately identifying the actual state of the fuel cell stack, adapting to complex operating environments, and more accurately capturing changes in the state of the fuel cell stack, providing an accurate basis for subsequent humidity control.

[0021] Optionally, in one embodiment of this application, the control module includes: a first control unit, configured to determine, when the actual state is a flooded state, 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 to be reduced to a first preset speed, and the three-way valve to enter a preset small circulation condition.

[0022] Through the above technical solution, the embodiments of this application can accurately determine the target humidity control action when the actual state is determined to be a flooded state. By controlling the bypass valve of the fuel cell air supply system to be fully opened, most of the incoming air does not pass through the humidifier, directly reducing the humidity of the incoming air, effectively improving the humidity environment inside the fuel cell 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 fuel cell stack.

[0023] Optionally, in one embodiment of this application, the control module further includes: a second control unit, configured 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 impedance value.

[0024] Through the above technical solution, the embodiments of this application can more accurately determine the opening degree of the bypass valve by comprehensively considering the air inflow rate and air humidity of the fuel cell stack when the actual state is determined to be a non-fault state. At the same time, the current closed-loop control opening degree of the bypass valve is generated based on the current impedance value. The impedance value can reflect the humidity situation inside the fuel cell stack. Through closed-loop control, the opening degree of the bypass valve can be adjusted in a timely manner according to the actual humidity feedback, further improving the accuracy of humidity control.

[0025] Optionally, in one embodiment of this application, the control module further includes: a third control unit, used to determine, when the actual state is a membrane dry state, 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 closed, the water pump speed to be increased to a second preset speed, the three-way valve to enter the large circulation mode, and the fan speed to be increased to a third preset speed.

[0026] Through the above technical solution, the embodiments of this application can, when the actual state is determined to be membrane dry, 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, restoring it from the membrane dry state to the normal state, further improving the performance of the fuel cell, and enhancing the durability and reliability of the stack.

[0027] Optionally, in one embodiment of this application, the control module further includes: a fourth control unit, configured to determine, when the actual state is a severe membrane dry state, 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 closed to enter the shutdown purging condition.

[0028] Through the above technical solution, the embodiments of this application can, when the actual state is determined to be a severe membrane dry state, control the bypass valve of the fuel cell air supply system to be fully closed and enter the shutdown purging state to clean and adjust the inside of the fuel cell stack, remove factors that may cause membrane dryness, create good internal environmental conditions for the fuel cell stack to resume normal operation, and improve the performance and stability of the fuel cell stack after it resumes operation.

[0029] A third aspect of this 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 for a fuel cell air supply system as described in the above embodiments.

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

[0031] A fifth aspect of this application provides a computer program product, including a computer program that, when executed, implements the humidity control method for the fuel cell air supply system described above.

[0032] This application embodiment can more accurately identify the actual state of the fuel cell stack by monitoring multiple parameters, including but not limited to impedance values ​​and pressure differences between the stack inlet and outlet, adapting to complex operating environments, capturing state changes, and providing accurate basis for humidity control. When the fuel cell stack is detected to be in a flooded state, precise humidity control actions are implemented, namely, fully opening the bypass valve to allow most of the air to bypass the humidifier and directly reduce the humidity of the air entering the stack, effectively improving the internal humidity environment of the fuel cell stack and promoting its recovery to a normal state. In a non-faulty state, the bypass valve opening is accurately determined by comprehensively considering the air inlet flow rate and air humidity. At the same time, a closed-loop control opening is generated based on the impedance value, and timely adjustments are made according to the 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 increasing the air humidity and promoting the fuel cell stack to recover from the membrane dry state to a normal state. For severe membrane dry states, the bypass valve is fully closed and the system enters a shutdown purging state to clean and adjust the internal structure of the fuel cell stack, removing membrane dry factors and creating good internal conditions for the fuel cell stack to resume normal operation, thereby improving subsequent operating performance and stability. In summary, through multi-parameter monitoring and status identification, the embodiments of this application can accurately implement humidity control actions according to the actual status of the fuel cell stack, effectively cope with conditions such as flooding and membrane dryness, improve the operational 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 this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0034] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0035] Figure 1 This is a schematic diagram of the air path and cooling water path structure of a fuel cell air supply system according to an embodiment of this application;

[0036] Figure 2 This is a flowchart of a humidity control method for a fuel cell air supply system according to an embodiment of this application;

[0037] Figure 3 This is a flowchart of a humidity control method for a fuel cell air supply system according to a specific embodiment of this application;

[0038] Figure 4This is a schematic diagram of the structure of a humidity control device for a fuel cell air supply system provided in an embodiment of this application;

[0039] Figure 5 This is a structural example diagram of a vehicle provided according to an embodiment of this application. Detailed Implementation

[0040] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0041] The following description, with reference to the accompanying drawings, outlines a humidity control method, apparatus, and vehicle for a fuel cell air supply system according to embodiments of this application. Addressing the technical problems mentioned in the background section, where relying solely on impedance to determine internal water content fails to accurately reflect the internal state of the fuel cell stack, leading to difficulties in timely and effective responses to faults such as membrane dryness and flooding, this application provides a humidity control method for a fuel cell air supply system. This method acquires the current impedance value, stack inlet / outlet pressure difference, and hydrogen pump power during fuel cell engine operation. Based on the hydrogen pump power and stack inlet / outlet pressure difference, the actual state of the fuel cell stack is identified, such as normal, flooded, membrane dry, or severely dry. Target humidity control actions are then matched according to different states, improving humidity control accuracy, maintaining a suitable environment for the fuel cell stack, enhancing the reliability of the fuel cell air supply system, and extending the stack's lifespan. This solves the problems in the related technologies.

[0042] Because relying solely on impedance to determine internal water content cannot accurately reflect the internal state of the fuel cell stack, it leads to technical problems such as difficulty in responding promptly and effectively to faults like membrane dryness and flooding.

[0043] To better understand the humidity control method for the fuel cell air supply system proposed in the embodiments of this application, a clear understanding of the structure of the fuel cell air supply system is first required, 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 embodiments of this application are shown.

[0044] The fuel cell air path consists of an air filter 1, an air compressor 2, a humidifier 3, and a bypass valve 4 for the humidifier. The humidifier 3 is a membrane humidifier, which humidifies the incoming air by using the humidity carried by the outgoing air. The larger the opening of the bypass valve 4, the lower the humidity of the incoming air. When the bypass valve 4 is fully open, some air does not pass through the humidifier 3, resulting in lower humidity of the incoming air. When the bypass valve 4 is fully closed, all the air passes through the humidifier 3, resulting in higher humidity of the incoming air.

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

[0046] Specifically, Figure 2 This is a schematic flowchart illustrating a humidity control method for a fuel cell air supply system provided in an embodiment of this 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 pressure difference between the stack inlet and outlet, and the power of the hydrogen pump are acquired.

[0049] Understandably, the current impedance value refers to the resistance characteristics of the fuel cell 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, catalyst activity, and other factors that affect current flow. The pressure difference between the fuel cell stack inlet and outlet refers to the pressure difference between the outlet and inlet of the fuel cell stack. This pressure difference reflects the resistance encountered when air or hydrogen flows through the stack and can be used to assess the smoothness of airflow and the blockage status inside the stack. The hydrogen pump power is used to deliver hydrogen to the fuel cell stack, and its power determines the hydrogen supply rate and the stack's operating capacity.

[0050] In actual operation, when the fuel cell engine is running, the current impedance value, pressure difference at the stack inlet and outlet, and hydrogen pump power are obtained through appropriate monitoring equipment and technologies. The impedance value can be obtained using a high-frequency impedance analyzer. This analyzer applies a high-frequency AC signal to the stack and measures the stack's response to the signal, thereby calculating the high-frequency impedance value. This measurement method accurately reflects the internal conductivity characteristics of the stack and the influence of humidity.

[0051] Furthermore, to obtain the pressure difference between the inlet and outlet of the fuel cell stack, high-precision differential pressure sensors can be installed at the inlet and outlet of the fuel cell stack respectively. The differential pressure sensors work based on the piezoresistive effect or the 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 deform or change its capacitance accordingly, thereby converting the pressure difference into an electrical signal for output, and monitoring and recording the pressure difference value 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, 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] This application embodiment can comprehensively understand the state of the fuel cell during operation by obtaining three key parameters: the current impedance value of the fuel cell air supply system, the pressure difference between the stack inlet and outlet, and the hydrogen pump power. Different parameters reflect different aspects of the fuel cell's performance and problems, providing rich data support for accurately diagnosing the working state 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 stack inlet and outlet.

[0055] Understandably, the actual state of a fuel cell stack refers to its real-world condition during operation, including normal operation, flooding, membrane dryness, and severe membrane dryness. The actual state of the stack is related to factors such as internal humidity, temperature, gas flow rate, and chemical reaction rate. By monitoring parameters such as hydrogen pump power and the pressure difference between the stack's inlet and outlet, the actual state of the stack can be identified, allowing for appropriate control measures to be taken to ensure the normal operation of the fuel cell.

[0056] Optionally, in one embodiment of this application, identifying the actual state of the fuel cell stack based on the current impedance value and the pressure difference between the fuel cell stack inlet and outlet includes: determining the actual range of the current impedance value and the pressure difference between the fuel cell stack inlet and outlet respectively; and matching the actual state based on the actual range of the current impedance value and the pressure difference between the fuel cell stack inlet and outlet.

[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 internal humidity of the fuel cell stack is in a water-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 internal humidity of 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 internal humidity of 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 internal humidity of the fuel cell stack is in a severely membrane-dry state.

[0058] The embodiments of this application can match the actual state according to the current impedance value and the actual range of the inlet and outlet pressure difference 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 execute the target humidity control action.

[0060] Understandably, the target humidity control action is a humidity control operation for the fuel cell air supply system determined based on 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 might be to fully open the bypass valve, reduce the water pump speed, or activate the three-way valve to enter the small circulation loop.

[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 flooded, the target humidity control action is determined to be the humidity control action of controlling 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 condition.

[0062] In actual implementation, based on the analysis of relevant parameters such as hydrogen pump power and fuel cell stack inlet and outlet pressure difference, it was determined that the fuel cell was in a flooded state, meaning the internal humidity was too high. Therefore, it was necessary to reduce the moisture introduced by the air to alleviate the flooding. For the bypass valve in the fuel cell air supply system, its control action was set to fully open, meaning most of the incoming air would bypass the humidifier, directly reducing the humidity of the incoming air. For the water pump, its speed was reduced to the lowest possible speed, decreasing the circulation of cooling water. This reduction in circulation would gradually increase the temperature of the fuel cell stack, which would facilitate the evaporation of moisture inside the stack, further improving the flooding situation. For the three-way valve, it was set to operate in a small circulation mode. This would change the operating mode of the entire cooling system, allowing for more effective adjustment of the cooling water flow path and flow rate. Combined with the control actions of the bypass valve and water pump, this would create favorable conditions for alleviating the flooding, enabling the internal humidity of the fuel cell stack to recover to a suitable level as quickly as possible.

[0063] In other embodiments, matching the target humidity control action of 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 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, and generating the current closed-loop control opening of the bypass valve based on the current impedance value.

[0064] Specifically, when the air inlet flow rate 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 should be appropriately increased, that is, the feedforward control value should be increased, so that some air can enter the fuel cell stack directly without passing through the humidifier, thereby regulating the humidity of the inlet air. Conversely, when the air inlet flow rate is small and the air humidity is low, in order to prevent excessively low humidity inside the fuel cell stack, the opening of the bypass valve should be appropriately reduced, that is, the feedforward control value should be reduced, so that more air passes through the humidifier to increase the humidity of the inlet air.

[0065] Furthermore, the current closed-loop control opening of the bypass valve is generated based on the current impedance value. The current impedance value, such as the high-frequency impedance value, reflects the humidity level inside the fuel cell stack. When the high-frequency impedance value changes, it indicates a change in the humidity inside the stack. Through the closed-loop control mechanism, the high-frequency impedance value is used as a feedback signal, and the opening of the bypass valve is adjusted in real time according to its changes. For example, when the high-frequency impedance value increases, it indicates that the humidity inside the stack may be decreasing. In this case, the opening of the bypass valve should be appropriately reduced to increase the humidity of the incoming air. When the high-frequency impedance value decreases, it indicates that the humidity inside the stack may be increasing. In this case, the opening of the bypass valve should be appropriately increased to decrease the humidity of the incoming air. Through this closed-loop control method, the opening of the bypass valve can be controlled more precisely, thereby more effectively regulating the humidity of the incoming air and maintaining 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 dry membrane state, the target humidity control action is determined to be the 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 the second preset speed, the three-way valve to enter the large circulation mode, and the fan speed to be increased to the third preset speed.

[0067] In this embodiment, when the actual state of the fuel cell stack is determined to be a membrane dry state, the bypass valve in the fuel cell air supply system is set to be fully closed. This is because in a membrane dry state, the internal humidity of the fuel cell stack is severely insufficient, requiring all incoming air to pass through a humidifier to increase humidity. Therefore, the bypass valve must be closed to ensure that no unhumidified air enters the fuel cell stack. For the water pump, its speed is increased to a second speed. This is because increasing the pump speed increases the circulation volume of cooling water. As the cooling water circulation volume increases, the temperature of the fuel cell stack decreases, thereby helping to reduce the evaporation of moisture inside the stack and alleviate membrane dryness. In the case of dry conditions; for the three-way valve, ensure it enters the large circulation mode. After the three-way valve enters the large circulation mode, the working mode of the cooling system changes, allowing the cooling water to flow through a wider area, effectively regulating the temperature of the fuel cell stack. In conjunction with the control actions of the bypass valve and water pump, they work together to improve the film dryness condition, enabling the internal humidity of the fuel cell stack to recover to a suitable level as soon as possible. For the fan, increase its speed to the third speed. Increasing the fan speed can accelerate the heat dissipation rate, further reduce the temperature of the fuel cell stack, thereby reducing water evaporation, helping to alleviate the film dryness condition, and ensuring that the internal humidity of 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 condition and / or the current impedance value, including: when the actual condition is a severe membrane dry condition, the target humidity control action is determined to be the humidity control action of controlling the bypass valve of the fuel cell air supply system to be fully closed to enter the shutdown purging condition.

[0069] On the one hand, in cases of severe membrane dryness, the bypass valves of the fuel cell air supply system are kept completely closed because the humidity inside the fuel cell stack is extremely low under these conditions. Specifically, to restore the humidity environment inside the fuel cell stack as quickly as possible, it is essential to ensure that all incoming air passes through the humidifier. Closing the bypass valves achieves this, allowing all incoming air to be treated by the humidifier and thus maximizing the humidity of the incoming air.

[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 purging state. Specifically, shutdown can prevent the stack from continuing to operate in a severely dry membrane state and suffering more serious damage, prevent irreversible damage to key components such as membrane electrodes due to excessive dryness, and the purging operation can remove factors that may cause membrane dryness, such as venting the dry air remaining inside the stack, creating a good internal environment for subsequent resumption of normal operation.

[0071] The aforementioned preset parameters can be obtained from, but are not limited to, experimental testing and / or theoretical calculations.

[0072] To better understand the humidity control method for the fuel cell air supply system proposed in this application, the following description is provided in conjunction with specific embodiments, such as... Figure 3 As shown, the humidity control principle of the fuel cell air supply system is as follows:

[0073] Step S301: Begin.

[0074] The fuel cell has started operating.

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

[0076] Step S303: W 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, then proceed to step S304.

[0078] Step S304: The internal humidity of the fuel cell stack is in a water-flooded state.

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

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

[0081] With the bypass valve fully open, most of the incoming air bypasses the humidifier, the water pump speed decreases, and the three-way valve enters a small circulation, causing the stack temperature to rise until it is no longer submerged.

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

[0083] If the hydrogen pump power is less than the second power but 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 but greater than the first pressure difference, then proceed to step S307.

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

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

[0086] Step S308: Based on HFR, perform closed-loop control on the opening degree of the bypass valve.

[0087] Through a closed-loop control mechanism, the high-frequency 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, then proceed to step S310.

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

[0091] Based on 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 the large circulation, and the fan speed increases.

[0093] With the bypass valve fully closed, all incoming air passes through the humidifier, the water pump speed increases, the three-way valve enters the large circulation, the fan speed increases, and the stack temperature decreases until it leaves the membrane dry state.

[0094] Step S312: W 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, then proceed to step S313.

[0096] Step S313: The internal humidity of the fuel cell stack is in a state of severe film dryness.

[0097] Based on the hydrogen pump power and the pressure difference between the inlet and outlet of the fuel cell stack, it was determined that the current internal state of the fuel cell stack is a severe membrane dryness state.

[0098] Step S314: Close the bypass valve completely and perform a shutdown purging.

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

[0100] As can be seen from this embodiment, during the operation of the fuel cell engine, the current impedance value, hydrogen pump power, and stack inlet / outlet pressure difference are acquired. Based on the values ​​of hydrogen pump power and stack inlet / outlet pressure difference, it is determined whether the internal humidity of the stack is in a normal or faulty state. If the stack humidity is in a normal state, the opening of the bypass valve is controlled in a closed loop based on the impedance value. If it is in a flooded state, the bypass valve is fully opened, preventing most of the incoming air from passing through the humidifier; the water pump speed is reduced, and the three-way valve enters a small circulation, increasing the stack temperature until it escapes the flooded state. If the stack humidity is not in a faulty state, the air inlet flow rate and air humidity are adjusted accordingly. The bypass valve is fed forward controlled, and its opening is controlled in a closed loop based on the impedance value. If a dry membrane condition is detected, the bypass valve is fully closed, allowing all incoming air to pass through the humidifier. The pump speed increases, the three-way valve enters the large circulation, and the fan speed increases, causing the stack temperature to decrease until the dry membrane condition is resolved. The bypass valve is fed forward controlled based on the air inflow rate and humidity, and its opening is controlled in a closed loop based on the impedance value. If a severe dry membrane condition is detected, the bypass valve is fully closed, and the system enters a shutdown purging phase until the severe dry membrane condition is resolved. Then, the control strategy for the dry membrane condition is applied.

[0101] The humidity control method for a fuel cell air supply system proposed in this application can acquire the current impedance value, stack inlet-outlet pressure difference, and hydrogen pump power during fuel cell engine operation. Based on the hydrogen pump power and stack inlet-outlet pressure difference, the actual state of the stack can be identified, such as normal, flooded, membrane dry, or severely dry. Target humidity control actions can then be matched according to different states to improve humidity control accuracy, maintain a suitable environment for the stack, enhance the reliability of the fuel cell air supply system, and extend the stack's service life.

[0102] Next, the humidity control device for a fuel cell air supply system according to an embodiment of this application is described with reference to the accompanying drawings.

[0103] Figure 4 This is a block diagram of the humidity control device of the fuel cell air supply system according to an embodiment of this 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 stack inlet and outlet, and the power of the hydrogen pump 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 based on the hydrogen pump power and the pressure difference between the 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 to control the fuel cell air supply system to perform the target humidity control action.

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

[0109] The interval determination unit is used to determine the actual interval of the current impedance value and the voltage difference between the inlet and outlet of the fuel cell stack.

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

[0111] Optionally, in one embodiment of this application, the control module 300 includes: a first control unit, used to determine, when the actual state is flooded, 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 to be reduced to a first preset speed, and the three-way valve to enter a preset small circulation condition.

[0112] Optionally, in one embodiment of this application, the control module 300 further includes: a second control unit, configured 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 impedance value.

[0113] Optionally, in one embodiment of this application, the control module 300 further includes: a third control unit, used to determine, when the actual state is a membrane dry state, 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 closed, the water pump speed to be increased to a second preset speed, the three-way valve to enter the large circulation mode, and the fan speed to be increased to a third preset speed.

[0114] Optionally, in one embodiment of this application, the control module 300 further includes: a fourth control unit, used to determine, when the actual state is a severe membrane dry state, 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 closed to enter the shutdown purging condition.

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

[0116] The humidity control device for the fuel cell air supply system proposed in this application can acquire the current impedance value, the pressure difference between the inlet and outlet of the fuel cell stack, and the power of the hydrogen pump when the fuel cell engine is running. Based on the power of the hydrogen pump and the pressure difference between the inlet and outlet of the fuel cell stack, it can identify the actual state of the fuel cell stack, such as normal, flooded, membrane dry, or severe membrane dry. In this way, it can match the target humidity control action according to different states, improve the humidity control accuracy, 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 this application. The vehicle may include:

[0118] The memory 501, the processor 502, and the computer program stored on the memory 501 and capable of running on the processor 502.

[0119] When the processor 502 executes the program, it implements the humidity control method of the fuel cell air supply system provided in the above embodiments.

[0120] Furthermore, the vehicle also includes:

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

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

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

[0124] If the memory 501, processor 502, and communication interface 503 are implemented independently, then the communication interface 503, memory 501, and processor 502 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of representation, Figure 5 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0125] Optionally, in a specific implementation, if the memory 501, processor 502, and communication interface 503 are integrated on a single chip, then the memory 501, processor 502, and communication interface 503 can communicate with each other through an internal interface.

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

[0127] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the humidity control method of the fuel cell air supply system described above.

[0128] This application also 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 described above.

[0129] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0130] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0131] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0132] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0133] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0134] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0135] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0136] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A humidity control method for a fuel cell air supply system, characterized in that, Includes the following steps: 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, wherein the pressure difference between the inlet and outlet of the fuel cell stack is the pressure difference between the inlet and outlet of air or hydrogen in the fuel cell stack. The actual state of the fuel cell stack is identified based on the hydrogen pump power and the pressure difference between the stack inlet and outlet. 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 execute the target humidity control action. The actual state is a membrane dry state, a severe membrane dry state, a flooded state, or a non-fault state. The membrane dry state, the severe membrane dry state, or the flooded state are matched only according to the actual state, while the non-fault state is matched by combining the actual state and the current impedance value. The step of identifying the actual state of the fuel cell stack based on the hydrogen pump power and the pressure difference between the stack inlet and outlet includes: Determine the actual ranges of the hydrogen pump power and the inlet / outlet pressure difference of the fuel cell stack, respectively. The actual state is matched according to the actual range of the hydrogen pump power and the inlet / outlet pressure difference of the fuel cell stack. 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, the target humidity control action is determined to be: fully opening the bypass valve of the fuel cell air supply system so that the incoming air does not pass through the humidifier; reducing the water pump speed to a first preset speed to reduce the circulation of cooling water; and putting the three-way valve into a preset small circulation mode to increase the humidity control action of the fuel cell stack temperature. When the actual state is a non-faulty 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 impedance value.

2. 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 includes: When the actual state is a dry membrane state, the target humidity control action is determined to be the 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 the second preset speed, and the three-way valve to enter the large circulation mode, so as to reduce the stack temperature and increase the fan speed to the third preset speed.

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 includes: When the actual state is a severe membrane dryness, the target humidity control action is determined to be the humidity control action that controls the bypass valve of the fuel cell air supply system to be fully closed in order to enter the shutdown purging condition.

4. A humidity control device for a fuel cell air supply system, characterized in that, include: The acquisition module is used to acquire the current impedance value of the fuel cell air supply system, the pressure difference between the fuel cell stack inlet and outlet, and the power of the hydrogen pump during the operation of the fuel cell engine, wherein the pressure difference between the fuel cell stack inlet and outlet is the pressure difference between the air or hydrogen inlet and outlet of the fuel cell stack. The identification module is used to identify the actual state of the fuel cell stack based on the hydrogen pump power and the pressure difference between the fuel cell stack inlet and outlet. The control module 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 to control the fuel cell air supply system to execute the target humidity control action. The actual state is a membrane dry state, a severe membrane dry state, a flooded state, or a non-fault state. The membrane dry state, severe membrane dry state, or flooded state are matched only according to the actual state, while the non-fault state is matched by combining the actual state and the current impedance value. The identification module includes: an interval determination unit, used to determine the actual interval of the current impedance value and the actual interval of the voltage difference between the inlet and outlet of the fuel cell stack; and a matching unit, used to match the actual state according to the actual interval of the current impedance value and the actual interval of the voltage difference between the inlet and outlet of the fuel cell stack. The control module includes: a first control unit, used to determine, when the actual state is a flooded state, the target humidity control action is to control the bypass valve of the fuel cell air supply system to be fully opened so that the incoming air does not pass through the humidifier; reduce the water pump speed to a first preset speed to reduce the circulation volume of cooling water; and put the three-way valve into a preset small circulation condition to increase the humidity control action of the fuel cell stack temperature. The control module further includes a second control unit, which, when the actual state is a non-fault state, determines 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, and generates the current closed-loop control opening of the bypass valve based on the current impedance value.

5. A vehicle, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the humidity control method for a fuel cell air supply system as described in any one of claims 1-3.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the humidity control method for the fuel cell air supply system as described in any one of claims 1-3.

7. A computer program product, comprising a computer program, characterized in that, The computer program is executed to implement the humidity control method for the fuel cell air supply system as described in any one of claims 1-3.

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