Fuel cell stack recovery activity or activation method and control system

Abstract

The application discloses a kind of fuel cell stack recovery activity or activation method and control system, the method includes the following steps: make the fuel cell stack at set current density steady operation, keep the pressure and flow of hydrogen path, the pressure and flow of water path are maintained constant during operation;The measurement ratio of air path is reduced to preset range, so that the fuel cell stack enters slightly insufficient gas state and is accompanied by voltage fluctuation of the fuel cell stack;And reciprocating adjustment the pressure of the air path, so that the fuel cell stack inside alternately realizes air insufficient gas and air supplement, and the pump hydrogen effect is formed by the alternate action of air insufficient gas and air supplement, to complete the activity recovery or rapid activation of the fuel cell stack.This scheme can keep current stable when operating, and the operation of repeated pressure change is simple, time-consuming is short, pump hydrogen effect is remarkable, fuel cell stack performance can be recovered in a short time, and it can also be used for rapid activation of new fuel cell stack, shorten activation time.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and more specifically to a method for restoring and activating the performance of a fuel cell stack based on the principle of hydrogen pumping, as well as a control system for restoring or activating the fuel cell stack. Background Technology

[0002] Current air-deficient recovery and activation solutions based on the hydrogen pumping principle have significant drawbacks: First, the recovery and activation effect is generally poor, failing to efficiently improve fuel cell stack performance; second, the voltage difference in the fuel cell stack during the air deficient process is large, especially for multiple fuel cell stacks, resulting in poor performance recovery consistency; third, the operation process is cumbersome, requiring frequent adjustments to multiple sets of parameters, and each processing session is time-consuming, making it difficult to meet the needs of rapid performance recovery or activation of new fuel cell stacks in actual production. Therefore, there is an urgent need to develop a technical solution that can achieve the purpose of hydrogen pumping, while also being simple to operate, time-efficient, effective, and adaptable to multiple fuel cell stacks.

[0003] The fuel cell stack consists of multiple single cells connected in series. Each single cell contains a three-layer core structure: anode (fuel side, through which hydrogen is introduced) - electrolyte membrane - cathode (oxidant side, through which air is introduced). It is equipped with three major fluid circuits: hydrogen circuit (anode gas supply channel), air circuit (cathode gas supply channel), and water circuit (cooling / humidity regulation channel), as well as an external electrode circuit (used to apply / output current). Summary of the Invention

[0004] The purpose of this invention is to overcome the problems of existing technologies, such as the generally poor performance of air-deficient recovery activation schemes based on the basic hydrogen pumping principle, large voltage differences in fuel cell stacks during air deficient conditions, cumbersome operation, and long processing time. To address these issues, a new method has been developed that achieves the purpose of hydrogen pumping while also being simple to operate, time-efficient, and highly effective, meeting the requirement of good consistency in performance recovery across multiple fuel cell stacks.

[0005] To achieve the above objectives, the present invention provides a method for restoring or activating the activity of a fuel cell stack, comprising the following steps: (1) Ensure that the fuel cell stack operates stably at a set current density, and maintain constant pressure and flow rate of hydrogen path and pressure and flow rate of water path during operation; (2) Reduce the air metering ratio to a preset range, causing the fuel cell stack to enter a slightly under-gas state accompanied by voltage fluctuations in the fuel cell stack; and (3) The pressure of the air path is adjusted repeatedly to alternately realize the air shortage and air replenishment inside the fuel cell stack. The alternating action of the air shortage and air replenishment forms a hydrogen pumping effect to complete the activity recovery or rapid activation of the fuel cell stack.

[0006] Preferably, the set current density ranges from 0.1 to 0.5 A / cm². 2 .

[0007] Preferably, the metering ratio of the air path is preset to a range of 1.0 to 1.5.

[0008] Preferably, the reciprocating adjustment of the air path pressure specifically involves: first adjusting the air path pressure to a first preset pressure value; after the actual pressure of the air path reaches the first preset pressure value, adjusting the air path pressure to a second preset pressure value; after the actual pressure of the air path reaches the second preset pressure value, adjusting it back to the first preset pressure value, and so on in a cycle.

[0009] Preferably, the difference between the first preset pressure value and the second preset pressure value is not less than 30 kPa.g.

[0010] Preferably, when the fuel cell stack is slightly under-gasified, the voltage of the fuel cell stack is maintained in the range of 0.01~0.05V.

[0011] Preferably, the number of cycles for adjusting the air pressure and the duration of each cycle vary depending on the specific fuel cell stack, and the number of cycles can be adjusted according to actual needs.

[0012] In a second aspect, the present invention provides a control system for restoring or activating the activity of a fuel cell stack, the system comprising: a memory storing instructions; and a processor that invokes the instructions in the memory.

[0013] Thirdly, the present invention provides a computer-readable storage medium storing instructions that, when executed by a processor, implement the aforementioned method for restoring or activating the fuel cell stack.

[0014] Fourthly, the present invention provides a computer program product comprising a computer program which, when executed by a processor, provides the above-described method for restoring or activating the activity of a fuel cell stack.

[0015] This invention significantly enhances the performance recovery and activation efficiency of fuel cell stacks. The key lies in applying a set current density through the external electrode circuit of the fuel cell stack and maintaining a constant current through current control in the external circuit, thus preventing current fluctuations from interfering with the voltage response during the subsequent "undergassing-to-replenishing" process. The hydrogen pressure and flow rate remain constant, ensuring the anode is always in a stable fuel supply state, preventing hydrogen-side parameters from interfering with the core performance. In subsequent activation operations, only the cathode air circuit pressure needs to be adjusted to artificially create an "undergassing-to-replenishing" cycle. The "concentration gradient" within the fuel cell stack is used to "pump hydrogen" and complete the fuel cell stack activation. This achieves advantages such as short processing time and simple operation, while also possessing strong versatility—it can be adapted for both fuel cell stack test benches and fuel cell systems. Furthermore, because all parameters remain stable during activation, the basic conditions are consistent, the recovery actions are synchronized, and the current is stable with minimal voltage fluctuations, resulting in a unified reaction state. This achieves "synchronous recovery of multiple stacks with good voltage consistency," and is more beneficial for multiple fuel cell stacks. Other features and advantages of this invention will be described in detail in the subsequent detailed implementation section. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of fuel cell stack activation.

[0017] Figure 2 This is a performance comparison chart of the fuel cell stack before and after performance recovery.

[0018] Figure 3 This is a graph showing the changes in voltage and air inlet pressure during the activation and recovery process of a fuel cell stack.

[0019] Figure 4 This is a graph showing the voltage and current changes during the activation and recovery process of a fuel cell stack. Detailed Implementation

[0020] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0021] In current industry-standard air-deficient recovery and activation schemes based on the hydrogen pumping principle, conventional methods require the introduction of inert gas to achieve the deficient gas level, resulting in significant voltage differences during deficient gas operation. Some methods relying solely on the gas itself without adding a load are too time-consuming, while those requiring a load necessitate real-time balancing of current, flow rate, and voltage, both of which are cumbersome. To address this, a new method has been developed that achieves the hydrogen pumping objective while being simple to operate, time-efficient, and highly effective, demonstrating good consistency in performance recovery across multiple fuel cell stacks.

[0022] In this invention, unless otherwise stated, the terms used are defined as follows: “metering ratio” refers to the ratio of the actual supply of reactant gases (hydrogen, air) to the theoretical consumption of the fuel cell stack reaction; “kPa.g” is a gauge pressure unit, representing the pressure difference relative to standard atmospheric pressure; “under-gas state” refers to a state in which the air supply is lower than the reaction demand of the fuel cell stack, resulting in slight voltage fluctuations.

[0023] Figure 1 This is a structural block diagram of the fuel cell stack recovery and activation provided in an embodiment of the present invention. Figure 1 As shown, there are three steps: (1) the fuel cell stack operates stably under a set current density, and the pressure and flow rate of the hydrogen path and the pressure and flow rate of the water path are kept constant during operation; (2) the metering ratio of the air path is reduced to a preset range, so that the fuel cell stack enters a slightly under-gas state and is accompanied by voltage fluctuations of the fuel cell stack; and (3) the pressure of the air path is adjusted repeatedly, so that the fuel cell stack alternately realizes air under-gas and air replenishment, and the alternating action of air under-gas and air replenishment forms a hydrogen pumping effect to complete the activity recovery or rapid activation of the fuel cell stack.

[0024] Optionally, apply 0.3 A / cm to the external electrode loop of the fuel cell stack. 2 The current, and the fuel cell stack needs to be 0.3 A / cm 2 Stable operation at current density is achieved. Hydrogen is introduced into the hydrogen path (anode side) of the fuel cell stack with the following parameters: hydrogen metering ratio 2.2, hydrogen path pressure 55 kPa·g (to stabilize anode side pressure and prevent unstable hydrogen diffusion due to pressure fluctuations), hydrogen dew point 45℃ (to control hydrogen humidity and prevent electrolyte membrane drying or flooding), and hydrogen heating tape (inlet) 58℃ (to maintain hydrogen temperature and match the fuel cell stack's operating temperature range). Air is introduced into the air path (cathode side) of the fuel cell stack with an air metering ratio of 3, air dew point temperature 56℃, air heating tape (inlet) 60℃, and air path pressure 50 kPa·g. Cooling water is introduced into the fuel cell stack's water path (cooling channels running through each individual cell), with an inlet water temperature set at 62℃, water path pressure less than or equal to air path pressure, and water flow rate at 1 A / cm². 2The required water supply is adjusted as needed (note: heat generation increases during low gas flow). Its function is to remove the heat generated by the fuel cell stack reaction (especially when heat generation increases during the subsequent low gas flow stage), preventing excessive temperature from damaging the fuel cell stack, and maintaining the humidity balance of the electrolyte membrane. All parameters remain constant.

[0025] Optionally, stable operation for 5 minutes ensures that the temperature, pressure, and gas concentration in all parts of the fuel cell stack reach a "steady state," ensuring that subsequent voltage changes are caused only by "air path pressure fluctuations." Afterward, gradually reduce the airflow: the air supply is gradually reduced via the equipment control system until the air path metering ratio reaches 1.2. For example... Figure 3 and Figure 4 As shown in the "CV001(v)" curve, if the fuel cell stack voltage begins to fluctuate slightly (at this point, only a single cell may be affected) and the current stabilizes, it indicates that the fuel cell stack has entered a slightly under-gas state. This phenomenon occurs before 160 seconds when the AIR feed pressure is irregular, which is part of the initial preparation and can be ignored. During this process, it is crucial to strictly maintain constant pressure and flow rate in the hydrogen and water paths, and control the under-gas degree only by adjusting the air flow rate to avoid interference from other parameter changes in the activation effect.

[0026] Optional, such as Figure 3 and Figure 4 As shown, after adjusting the air supply, the activation process officially begins in 160 seconds. At this time, the voltage fluctuation range stabilizes at 0.01~0.02V, and the current remains constant. The air circuit pressure is then adjusted: first, the air circuit pressure is set to 50kPa·g as the first preset pressure value via the control system, and real-time monitoring is performed. Figure 3 The "AIR feed pressure_PV(kPa)" curve is used to monitor the pressure. Once the actual pressure reaches the first preset pressure value of 50 kPa·g (or after a period of time), the air pressure is adjusted to the second preset pressure value of 10 kPa·g. After the actual pressure reaches the second preset pressure value of 10 kPa·g (or after a period of time), the air pressure is adjusted back to the first preset pressure value. Once the actual pressure reaches the first preset pressure value, one pressure cycle is completed. Each pressure adjustment can be observed... Figure 3 The voltage curve changes as follows: When the air pressure reaches the first preset pressure value of 50 kPa·g, the voltage rises to approximately 0.8 V during complete under-gas operation. When the air pressure drops to the second preset pressure value of 10 kPa·g, the voltage recovers to 0.01~0.02 V. Each cycle lasts approximately 50 seconds (this may vary depending on the fuel cell stack specifications). Repeat the above pressure cycle 60 times (the number of cycles can be adjusted according to actual needs).

[0027] After the experiment was completed, the parameters of the fuel cell stack were compared and obtained. Figure 2By comparing the two curves, we can see that after the fuel cell stack is restored, the average cell voltage is significantly higher than before restoration across the entire current density range. This indicates that the restored fuel cell stack not only maintains higher electrochemical activity at low current densities, but also exhibits weaker polarization losses and better energy conversion efficiency as the current density increases. The overall performance is comprehensively and effectively improved, and it can demonstrate better power generation capabilities under various current load conditions.

[0028] The fuel cell stack reactivation or activation method includes a processor and a memory. The control and adjustment of various parameters during the activation process are stored in the memory, and the processor executes the program units stored in the memory to achieve the corresponding functions.

[0029] The processor contains a kernel, which retrieves the corresponding program units from memory. One or more kernels can be configured, and by adjusting kernel parameters, the fuel cell stack can automatically control various parameters during activation, greatly improving production efficiency.

[0030] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0031] This invention provides a storage medium storing a program that, when executed by a processor, implements the method for restoring or activating the fuel cell stack.

[0032] This invention provides a processor for running a program, wherein the program executes a method for restoring or activating the fuel cell stack.

[0033] This invention provides a device including a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it performs the following steps: stably operating the fuel cell stack at a set current density, maintaining constant pressure and flow rate in both the hydrogen and water paths during operation; reducing the metering ratio of the air path to a preset range, causing the fuel cell stack to enter a slightly under-gas state accompanied by voltage fluctuations; and repeatedly adjusting the pressure of the air path, alternating between air under-gas and air replenishment within the fuel cell stack, thereby creating a hydrogen pumping effect to restore or rapidly activate the fuel cell stack.

[0034] Furthermore, the set current density ranges from 0.1 to 0.5 A / cm². 2 .

[0035] Furthermore, the metering ratio of the air path is preset to a range of 1.0 to 1.5.

[0036] Furthermore, the pressure of the air path is adjusted to a first preset pressure value. After the actual pressure of the air path reaches the first preset pressure value, the pressure of the air path is adjusted to a second preset pressure value. After the actual pressure of the air path reaches the second preset pressure value, it is adjusted back to the first preset pressure value, and so on.

[0037] Furthermore, the difference between the first preset pressure value and the second preset pressure value is not less than 30 kPa.g.

[0038] Furthermore, when the fuel cell stack is slightly under-gasified, the voltage of the fuel cell stack is maintained in the range of 0.01~0.05V.

[0039] The devices mentioned in this article can be servers, PCs, tablets, mobile phones, etc.

[0040] This application also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program with the following steps: ensuring stable operation of the fuel cell stack at a set current density, maintaining constant pressure and flow rate in the hydrogen path and water path during operation; reducing the metering ratio of the air path to a preset range, causing the fuel cell stack to enter a slightly under-gas state accompanied by voltage fluctuations; and repeatedly adjusting the pressure of the air path, causing alternating air under-gas and air replenishment within the fuel cell stack, thereby creating a hydrogen pumping effect through the alternating action of air under-gas and air replenishment to achieve activity recovery or rapid activation of the fuel cell stack.

[0041] Furthermore, the set current density ranges from 0.1 to 0.5 A / cm². 2 .

[0042] Furthermore, the metering ratio of the air path is preset to a range of 1.0 to 1.5.

[0043] Furthermore, the pressure of the air path is adjusted to a first preset pressure value. After the actual pressure of the air path reaches the first preset pressure value, the pressure of the air path is adjusted to a second preset pressure value. After the actual pressure of the air path reaches the second preset pressure value, it is adjusted back to the first preset pressure value, and so on.

[0044] Furthermore, the difference between the first preset pressure value and the second preset pressure value is not less than 30 kPa.g.

[0045] Furthermore, when the fuel cell stack is slightly under-gasified, the voltage of the fuel cell stack is maintained in the range of 0.01~0.05V.

[0046] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0047] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0048] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0049] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0050] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0051] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0052] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0053] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0054] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for restoring or activating the activity of a fuel cell stack, characterized in that, Includes the following steps: (1) Ensure that the fuel cell stack operates stably at a set current density, and maintain constant pressure and flow rate of hydrogen path and pressure and flow rate of water path during operation; (2) Reduce the metering ratio of the air path to a preset range, so that the fuel cell stack enters a slightly under-gas state and is accompanied by voltage fluctuations in the fuel cell stack; as well as (3) The pressure of the air path is adjusted repeatedly to alternately realize the air shortage and air replenishment inside the fuel cell stack. The alternating action of the air shortage and air replenishment forms a hydrogen pumping effect to complete the activity recovery or rapid activation of the fuel cell stack. The set current density ranges from 0.1 to 0.5 A / cm². 2 ; The metering ratio of the air circuit is preset to a range of 1.0 to 1.5; The reciprocating adjustment of the air path pressure specifically involves: first adjusting the air path pressure to a first preset pressure value; after the actual pressure of the air path reaches the first preset pressure value, adjusting the air path pressure to a second preset pressure value; after the actual pressure of the air path reaches the second preset pressure value, adjusting it back to the first preset pressure value, and so on in a cycle. The difference between the first preset pressure value and the second preset pressure value is not less than 30 kPa.g.

2. The method according to claim 1, characterized in that, When the fuel cell stack is slightly under-gasified in step (2), the voltage of the fuel cell stack is maintained in the range of 0.01~0.05V.

3. The method according to claim 1, characterized in that, The number of cycles for adjusting the air pressure in step (3) and the duration of each cycle vary depending on the specific fuel cell stack.

4. A control system for restoring or activating the activity of a fuel cell stack, characterized in that, The system includes: A memory containing instructions; and A processor that invokes the instructions in the memory to execute the method for restoring or activating a fuel cell stack according to any one of claims 1 to 3.

5. A computer-readable storage medium storing instructions thereon, characterized in that, When the instruction is executed by the processor, it implements the method for restoring or activating the fuel cell stack according to any one of claims 1 to 3.

6. A computer program product, characterized in that, Includes a computer program, which, when executed by a processor, is a method for restoring or activating a fuel cell stack according to any one of claims 1 to 3.

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