A method and system for designing a high power monoblock fuel cell stack system

Abstract

The application belongs to the technical field of fuel cells, and discloses a design method and system of a high-power single fuel cell stack system, wherein the method comprises the following steps: based on a target working voltage of a to-be-designed stack system and an average output voltage V cell of a single cell, calculating a required number of single cells N; based on an output rated power Pcell of the single cell, calculating a single cell active area S; judging whether the number of single cells N is less than a first preset number; if yes, judging whether the single cell active area S is greater than a preset area; if no, judging whether the number of single cells N is greater than a second preset number; after the conditions are met, calculating a hydrogen demand and an air demand of the stack system; integrating the N single cells, a hydrogen supply system and an air supply system into the stack system, and performing airtightness experiment on the stack system, and then activating the stack system until the stack system reaches a preset working state, thereby completing the design of the stack system.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, and more specifically, relates to a design method and system for a high-power single-cell fuel cell stack system. Background Technology

[0002] To achieve high-power power output, current research primarily employs parallel connection of multiple fuel cell stacks to construct high-power fuel cells. However, research on utilizing single high-power fuel cells is relatively limited. The paper "MW cogenerated proton exchange membrane fuel cell combined heat and power system design for eco-neighborhoods in North China" (Lixin Fan, Zhengkai Tu, Xiaobing Luo, Siew Hwa Chan, International Journal of Hydrogen Energy, 10.1016 / J.IJHYDENE.2021.11.012) discloses a method for connecting multiple fuel cell stacks in series, but it suffers from issues such as gas distribution, heat dissipation design, and stack consistency, failing to achieve efficient fuel distribution and suitability for various application scenarios. While single fuel cell stacks are more compact and better suited for power plant environments, a mature and effective method for designing integrated stack systems of high-power single fuel cells that meet practical applications is lacking. Therefore, designing high-power single fuel cell stack systems with efficient fuel distribution, thermal management capabilities, and high fuel utilization to adapt to the high-power operating conditions of megawatt-level applications, such as power generation, is of great significance. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a design method and stack system for a high-power single-cell fuel cell stack system, in order to achieve efficient fuel distribution and adapt to high-power operating conditions in megawatt-level application scenarios.

[0004] To achieve the above objectives, the present invention provides a design method for a high-power single-cell fuel cell stack system, the design method comprising:

[0005] S1, Target operating voltage V based on the fuel cell system tot and average output voltage of a single battery V cell Calculate the required number of single cells N;

[0006] Based on the rated output power P of a single battery cell Calculate the active area S of a single cell;

[0007] S2. Determine whether the number of single batteries N is less than a first preset number:

[0008] If yes, then continue to determine whether the active area S of the single cell is greater than the preset area: if yes, the length-to-width ratio of each single cell needs to be adjusted to make the current distribution inside it uniform; if no, then only the thermal management system of the stack system is adjusted to make the temperature distribution of the stack system uniform.

[0009] If not, further determine whether the number of single cells is greater than the second preset number: if yes, adjust the air intake manifold arrangement of the fuel cell stack system to make its gas distribution uniform, and at the same time adjust the thermal management system of the fuel cell stack system to make the temperature distribution of the fuel cell stack system uniform; if not, proceed directly to the next step.

[0010] S3, Based on the target rated power P of the fuel cell system e Calculate the hydrogen demand of the hydrogen supply system in the fuel cell stack system;

[0011] Based on the target rated power P e Calculate the air demand of the air supply system in the fuel cell stack system;

[0012] S4, transfer N single cells 、 The hydrogen supply system corresponding to the hydrogen consumption calculated in step S3 and the air supply system corresponding to the air consumption are integrated into the fuel cell stack system. After conducting an airtightness test on the integrated fuel cell stack system, it is activated until the integrated fuel cell stack system reaches the preset working state, thus completing the fuel cell stack system design.

[0013] Furthermore, in step S4, the airtightness testing steps include:

[0014] Nitrogen gas was introduced into the hydrogen side, oxygen side, and cooling circuit of the integrated fuel cell stack system to bring the pressure of the integrated fuel cell stack system to 150 kPa, and the pressure was maintained for a certain period of time. It was then determined whether the pressure change of the integrated fuel cell stack system within the preset time exceeded 10 kPa.

[0015] If not, stop the airtightness test and proceed with activation;

[0016] If so, the sealing components of the integrated fuel cell stack system need to be tightened again and the airtightness test needs to be repeated until the pressure change of the integrated fuel cell stack system does not exceed 10 kPa.

[0017] Furthermore, during step S4, when activating the integrated fuel cell stack system, the following steps are also performed:

[0018] S401. Real-time reading of the integrated fuel cell stack system's stack temperature distribution, operating current, and voltage; calculation of real-time output power P based on operating current and output voltage. out ;

[0019] S402, Determine the output power P out Has the rated power P been reached? e And whether the temperature distribution of the fuel cell stack meets the temperature requirements: if yes, continue activation; if not, adjust the operating conditions and temperature of the integrated fuel cell stack system until the output power P is achieved. out The fuel cell stack temperature distribution meets the preset conditions, thus completing the fuel cell stack system design.

[0020] Furthermore, in step S2, the first preset number is 200; the preset area is preferably 1000 cm². 2 The second preset number is preferably 500.

[0021] Furthermore, the pressure holding time is preferably 1 minute.

[0022] Furthermore, step S4, the activation step of the integrated fuel cell stack system, includes:

[0023] The integrated fuel cell stack system is sequentially loaded with current at preset current densities, and operates for a certain period of time at each current density. When the single cell output voltage corresponding to any current density reaches the preset protection voltage, the integrated fuel cell stack system continues to operate at the corresponding current density for a certain period of time until the single cell output voltage is lower than the preset protection voltage. Then, the current is gradually unloaded and activation is stopped.

[0024] Furthermore, the preset current density is preferably 50 mA / cm². 2 The optimal operating time for the fuel cell stack system after airtightness testing is 30 seconds at each current density.

[0025] Furthermore, when the single-cell output voltage corresponding to any applied current density reaches the preset protection voltage, the integrated stack system is made to operate continuously for 300s at that corresponding current density; the preset protection voltage is preferably 0.35V.

[0026] Furthermore, in step S4, the integrated fuel cell stack system also includes a cooling system. The cooling system adopts a dual-path cooling circulation. One large circulation path is where the coolant flows out of the integrated fuel cell stack system, passes through the back pressure valve, thermostat, radiator, and water pump to dissipate heat, and then returns to the cooling channel. The other small circulation path is where the coolant flows through the back pressure valve, thermostat, water pump, and heating cable to raise its temperature before returning to the cooling channel. This is suitable for cold start and low-output operating conditions. In step S4, the integrated fuel cell stack system also includes a control system, which is used to monitor the operating parameters of the fuel cell stack system during operation.

[0027] According to another aspect of the present invention, a design system for a high-power single-cell fuel cell stack system is also disclosed, the design system comprising:

[0028] The data processing module is used to calculate the required number of single cells N and the active area of ​​a single cell S; it is also used to calculate the hydrogen and air consumption of the fuel cell stack system to be designed.

[0029] The result judgment module is used to determine whether the number of single cells N is less than a first preset number, to determine whether the active area S of the single cell is greater than a preset area, and to further determine whether the number of single cells N is greater than a second preset number.

[0030] The fuel cell stack system parameter design module is used to design the uniformity of current distribution within each individual cell; to design the uniformity of gas distribution in the fuel cell stack system; and to design the uniformity of temperature distribution in the fuel cell stack system.

[0031] The fuel cell stack system testing module is used to perform airtightness tests and activation on the integrated fuel cell stack system.

[0032] Compared with the prior art, the above-described technical solutions conceived in this invention have the following main advantages:

[0033] The fuel cell stack involved in this invention is designed based on two factors: rated output power and output voltage. The rated output power of the stack is the product of the output voltage and output current. The average output voltage of most single cells is between 0.6 and 0.8V, and the voltage-current relationship can be determined through historical operating data of the single cells. The design method disclosed in this invention is based on the target output power of the stack system to be designed and the active area of ​​the single cell to calculate the required number of single cells and the volume of the stack system. Based on the number of single cells, the gas distribution uniformity, current distribution uniformity, and temperature distribution uniformity of the stack system are specifically designed. After integrating a specific number of single cells with a pre-designed cooling system and control system, airtightness testing and activation are performed to further accelerate the membrane electrode wetting process of the stack system, enabling the catalyst of the stack system to be at its optimal activity, thereby further improving the output efficiency of the stack system.

[0034] The design method of this invention is simple to operate, and the resulting fuel cell stack system has better performance and higher output efficiency. This invention enables rapid design of high-power fuel cell stacks and their systems, facilitates the rapid determination of key technical parameters of the stack system, simplifies the design process, and provides a technical reference for the design of high-power fuel cell stacks. This invention provides technical guidance on the operating parameters of the hydrogen supply system, air supply system, and thermal management system during system integration, and also provides airtightness testing standards applicable to engineering practice, improving the safety of the fuel cell stack system.

[0035] This invention also uses an energy efficiency evaluation coefficient to determine whether the relationship between the gas distribution uniformity and output power of the fuel cell stack system designed by this method is suitable for fuel cell stack systems with efficient fuel distribution, thermal management capabilities and high fuel utilization, thereby enabling the designed fuel cell stack system to better adapt to megawatt-level application fields, such as power generation and other high-efficiency, high-power operating conditions.

[0036] In summary, this invention has the advantages of simplifying the design process, quickly determining system parameters, improving system operation security, and ensuring output consistency. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the design method flow according to an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the integrated fuel cell stack system structure according to an embodiment of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0040] Example 1

[0041] The open-circuit voltage of a single proton exchange membrane fuel cell is approximately 1V. To achieve a higher voltage output, multiple single cells with connected gas flow fields and electrodes must be linked in series to form a stack. Fuel cell stacks are designed based on two factors: rated output power and output voltage. The rated output power is the product of the stack's output voltage and output current. The average output voltage of most single cells is between 0.6 and 0.8V, and the voltage-current relationship can be determined using historical operating data from individual cells.

[0042] This embodiment provides a design method for a high-power single-cell fuel cell stack system. The data processing and calculations involved can be implemented using various existing computing software, including but not limited to MATLAB and various types of simulation software. Specific steps of the design method are described in [reference needed]. Figure 1 As shown, it includes:

[0043] S1, via the target operating voltage V of the fuel cell tot and target total fixed power P e To determine the structural parameters of a fuel cell stack system, it is generally advisable to base the parameters on a single cell at i = 600 mA·cm. -2 Average output voltage V at current density cell Designed with a voltage of 0.6V, based on Determine the number of individual battery cells; determine the power output P based on the target total output. e Determine the rated output power of a single battery Then, the area of ​​a single cell is determined by the rated output power of the single cell.

[0044] Based on the target operating voltage V of the fuel cell stack system to be designed tot and average output voltage of a single battery V cell Calculate the required number of single cells N:

[0045]

[0046] Based on the rated output power P of a single battery cell The formula for calculating the active area S of a single cell is as follows:

[0047]

[0048] Where i = 600mA·cm -2 ;

[0049] S2. Determine whether the number of single batteries N is less than the first preset number 200:

[0050] If so, then continue to determine whether the active area S of a single cell is greater than the preset area: if so, the current distribution within each single cell needs to be designed for uniformity; if not, only the temperature distribution of the stack system to be designed needs to be designed for uniformity. In this embodiment, the preset area is selected as 1000 cm². 2 ;

[0051] If not, then further determine whether the number of single cells is greater than the second preset number of 500: if yes, then perform gas distribution uniformity design and temperature distribution uniformity design on the fuel cell stack system to be designed; if it is between 200 and 500, then proceed directly to the next step of design.

[0052] The aforementioned design for uniform current distribution is to make the internal current distribution uniform by adjusting the length-to-width ratio of each single cell under different operating conditions.

[0053] The temperature distribution uniformity design is as follows: the thermal management system of the fuel cell stack is adjusted to ensure a uniform temperature distribution in the fuel cell stack system for different operating conditions.

[0054] The gas distribution uniformity design involves adjusting the arrangement of the fuel cell stack system's intake manifold to ensure uniform gas distribution.

[0055] The current distribution uniformity design method, gas distribution uniformity design method, and temperature distribution uniformity design method used in this invention are all technical means commonly used by those skilled in the art, and are not the focus of this invention, so they will not be described in detail here.

[0056] S3, Target rated power P based on the fuel cell stack system to be designed e The hydrogen demand of the fuel cell stack system's hydrogen supply system is calculated. The hydrogen supply system can improve the hydrogen utilization rate of the fuel cell stack system, discharge liquid water, and ensure the stability of the fuel cell stack system. The formula for calculating its hydrogen consumption is as follows:

[0057]

[0058] Where: F is the Faraday constant; V cell P represents the average output voltage of a single battery. e The target rated power;

[0059] Based on the target rated power P e The air demand of the fuel cell stack system's air supply system is calculated using the following formula:

[0060]

[0061] Where: λ is the air metering ratio, which is 2.5-3.0;

[0062] Outside air flows through the fuel cell stack system's filters, air compressor, and humidifier before entering the system. During startup, when the system load is low, the high temperature of the exhaust gas (exhaust air) is used to rapidly raise the stack temperature, thus improving startup performance. The control system controls the air supply system's gas distribution and its dynamic response time with the control system, ensuring startup time ≤ 6 seconds. When the stack system is at rated power output, the high temperature of the recycled exhaust gas is used to maintain the stack temperature. Simultaneously, its high humidity mitigates the impact of insufficient humidity at the fuel cell electrodes caused by low power output on stack stability, further extending system lifespan. After the stack system stops outputting gas, the air supply system controls continuous air circulation over a certain period, coordinating with the hydrogen supply system designed in the previous step to gradually consume hydrogen in the closed hydrogen loop. Simultaneously, the air volume in the air supply system is reduced, lowering the stack voltage until it approaches zero.

[0063] S4. Based on the hydrogen and air consumption calculated in step S3, integrate the N single cells, hydrogen supply system, air supply system, and the necessary cooling and control systems of the fuel cell stack into the fuel cell stack system. After conducting an airtightness test on the integrated fuel cell stack system, activate it until the integrated fuel cell stack system reaches the required working state to complete the fuel cell stack system design.

[0064] The cooling system's cooling cycle and cold start are pre-designed. The cooling cycle adopts a dual-path cooling cycle. The large loop is where the coolant flows out of the fuel cell stack system, passes through the back pressure valve, thermostat, radiator, and water pump to dissipate heat, and then returns to the cooling channel. This is suitable for high-power operating conditions. The small loop is where the coolant flows through the back pressure valve, thermostat, water pump, and heating cable to raise its temperature before returning to the cooling channel. This is suitable for cold start and low-output operating conditions.

[0065] The aforementioned control system is also pre-designed. This control system can monitor the operating parameters such as voltage, temperature and pressure of the fuel cell stack during the operation of the fuel cell stack system, and control the operation of other components in the fuel cell stack system, such as controlling the air compressor flow, hydrogen flow, solenoid valve opening and closing, and the operation of the fuel cell stack system itself.

[0066] In step S2, the design of uniform current distribution and uniform gas distribution can be achieved by optimizing the flow field or the air intake method, such as reducing the flow length of gas in the bipolar plate or using multiple air intakes. To reduce gas flow resistance, direct-flow air intake is preferred. The design of uniform temperature distribution can be achieved by enhancing heat transfer, such as using a material with good thermal conductivity to make the bipolar plate, using water cooling, changing the cooling inlet parameters, or enhancing heat transfer. The aforementioned design of uniform current distribution, uniform gas distribution, and uniform temperature distribution are common design methods used by those skilled in the art and are not the focus of this invention.

[0067] In step S4, the airtightness test includes the following steps:

[0068] Nitrogen gas was introduced into the hydrogen side, oxygen side, and cooling circuit of the integrated fuel cell stack system to bring the pressure of the integrated fuel cell stack system to 150 kPa, and the pressure was maintained for 1 minute. It was then determined whether the pressure change of the integrated fuel cell stack system within the preset time exceeded 10 kPa.

[0069] If the pressure does not exceed 10 kPa, stop the airtightness test and proceed with activation;

[0070] If the pressure exceeds 10 kPa, the sealing components of the integrated fuel cell stack system need to be tightened again and the airtightness test needs to be repeated until the pressure change of the integrated fuel cell stack system does not exceed 10 kPa before activation can begin.

[0071] Step S4, the activation step of the integrated fuel cell stack system, includes:

[0072] The integrated fuel cell stack system is sequentially loaded with current at preset current densities and operated for a certain period of time at each current density. When the single cell output voltage corresponding to any current density reaches the preset protection voltage, the integrated fuel cell stack system is continuously operated at the corresponding current density for 300 seconds until the single cell output voltage is lower than the preset protection voltage. Then, the current is gradually unloaded and activation is stopped.

[0073] The aforementioned preset current density is preferably 50 mA / cm². 2 The operating time of the fuel cell stack system after the airtightness test is preferably 30s at each current density; the aforementioned preset protection voltage is preferably 0.35V.

[0074] During the activation process of the fuel cell stack system in step S4: First, the stack temperature distribution, operating current, and voltage of the integrated fuel cell stack system are read in real time, and the real-time output power P is calculated based on the operating current and output voltage. out Then determine the output power P. out Has the rated power P been reached? e And whether the temperature distribution of the fuel cell stack meets the temperature requirements: if so, continue activation and observe the relevant operating parameters; if not, adjust the operating conditions and temperature of the integrated fuel cell stack system until the output power P is achieved. out And when the temperature distribution of the fuel cell stack meets the required conditions, the fuel cell stack system design is completed, resulting in a fuel cell stack system with high output efficiency.

[0075] Example 2

[0076] This embodiment provides a design method for a high-power single-cell fuel cell stack system. The data processing and calculation involved can be implemented through the following design system: a design system for a high-power single-cell fuel cell stack system, comprising: a data processing module for calculating the required number of single cells N and the active area S of a single cell; for calculating the hydrogen and air consumption of the stack system to be designed; a result judgment module for judging whether the number of single cells N is less than a first preset number, whether the active area S of a single cell is greater than a preset area, and further judging whether the number of single cells N is greater than a second preset number; a stack system parameter design module for designing the uniformity of current distribution in each single cell; for designing the uniformity of gas distribution in the stack system to be designed; for designing the uniformity of temperature distribution in the stack system to be designed; and a stack system detection module for conducting airtightness tests and activation on the integrated stack system.

[0077] For specific steps of the design method, please refer to Example 1:

[0078] S1. Determine the structural parameters of the fuel cell stack system based on the target operating voltage of 110V and the target total rated power of 100kW. Generally, this can be based on a single cell operating at i = 600mA·cm. -2 Average output voltage V at current density cell Designed with a voltage of 0.6V, based on The number of individual battery cells is determined to be 184; the total power output P is determined based on the target total output. e Determine the rated output power of a single battery The power output is 0.54kW, and the area of ​​a single cell is determined by the rated power output of the single cell. 900cm 2 ;

[0079] Based on the target operating voltage V of the fuel cell stack system to be designed tot The required number of single cells N is calculated based on the average output voltage Vcell of a single cell:

[0080]

[0081] Based on the rated output power P of a single battery cell The formula for calculating the active area S of a single cell is as follows:

[0082]

[0083] Where i = 600mA·cm -2 ;

[0084] S2. Determine whether the number of single batteries N is less than the first preset number 100:

[0085] If so, then continue to determine whether the active area S of the single cell is greater than 500 cm². 2 If yes, the current distribution within each individual cell needs to be designed for uniformity; otherwise, only the temperature distribution of the stack system to be designed needs to be designed for uniformity.

[0086] Since N is 184 pieces in this embodiment, which is not less than 100, it is further determined whether the number of single cells is greater than the second preset number 500: if it is determined that N in this embodiment is between 100 and 500, then proceed directly to the next step of design.

[0087] S3, Target rated power P based on the fuel cell stack system to be designed e The hydrogen demand of the fuel cell stack system's hydrogen supply system is calculated. The hydrogen supply system can improve the hydrogen utilization rate of the fuel cell stack system, discharge liquid water, and ensure the stability of the fuel cell stack system. The formula for calculating its hydrogen consumption is as follows:

[0088]

[0089] Where: F is the Faraday constant; V cell P represents the average output voltage of a single battery. e The target rated power;

[0090] Based on the target rated power P e The air demand of the fuel cell stack system's air supply system is calculated using the following formula:

[0091]

[0092] Wherein: λ is the air metering ratio, which is 2.5-3.0, and preferably 3 in this embodiment;

[0093] Outside air flows through the fuel cell stack system's filters, air compressor, and humidifier before entering the system. During startup, when the system load is low, the high temperature of the exhaust gas (exhaust air) is used to rapidly raise the stack temperature, thus improving startup performance. The control system controls the air supply system's gas distribution and its dynamic response time with the control system, ensuring startup time ≤ 6 seconds. When the stack system is at rated power output, the high temperature of the recycled exhaust gas is used to maintain the stack temperature. Simultaneously, its high humidity mitigates the impact of insufficient humidity at the fuel cell electrodes caused by low power output on stack stability, further extending system lifespan. After the stack stops outputting gas, the air supply system controls continuous air circulation over a certain period, coordinating with the hydrogen supply system designed in the previous step to gradually consume hydrogen in the closed hydrogen loop. Simultaneously, the air volume in the air supply system is reduced, lowering the stack voltage until it approaches zero.

[0094] S4. Based on the hydrogen and air consumption calculated in step S3 (the calculation results are not shown; the results will vary depending on the air metering ratio, and should be determined according to the actual situation), integrate the aforementioned N single cells, hydrogen supply system, air supply system, and essential modules such as cooling system and control system of the fuel cell stack into the fuel cell stack system. The integrated fuel cell stack system is as follows: Figure 2 As shown, the integrated fuel cell stack system is activated after an airtightness test is performed until it reaches the required operating state, thus completing the fuel cell stack system design.

[0095] The integrated fuel cell stack system in this embodiment is as follows: Figure 2As shown, the cooling system's cooling cycle and cold start are pre-designed. The cooling cycle adopts a dual-path cooling cycle. The large loop is where the coolant flows out of the fuel cell stack system and then flows through the back pressure valve, thermostat, radiator, and water pump to dissipate heat before returning to the cooling channel. This is suitable for high-power operating conditions. The small loop is where the coolant flows through the back pressure valve, thermostat, water pump, and heating cable to raise its temperature before returning to the cooling channel. This is suitable for cold start and low-output operating conditions.

[0096] The aforementioned control system is also pre-designed. This control system can monitor the operating parameters such as voltage, temperature and pressure of the fuel cell stack during the operation of the fuel cell stack system, and control the operation of other components in the fuel cell stack system, such as controlling the air compressor flow, hydrogen flow, solenoid valve opening and closing, and the operation of the fuel cell stack system itself.

[0097] In step S2, the design of uniform current distribution and uniform gas distribution can be achieved by optimizing the flow field or the air intake method, such as reducing the flow length of gas in the bipolar plate or using multiple air intakes. To reduce gas flow resistance, direct-flow air intake is preferred. The design of uniform temperature distribution can be achieved by enhancing heat transfer, such as using a material with good thermal conductivity to make the bipolar plate, using water cooling, changing the cooling inlet parameters, or enhancing heat transfer. The aforementioned design of uniform current distribution, uniform gas distribution, and uniform temperature distribution are common design methods used by those skilled in the art and are not the focus of this invention.

[0098] In step S4, the airtightness test includes the following steps:

[0099] Nitrogen gas was introduced into the hydrogen side, oxygen side, and cooling circuit of the integrated fuel cell stack system to bring the pressure of the integrated fuel cell stack system to 150 kPa, and the pressure was maintained for 1 minute. It was then determined whether the pressure change of the integrated fuel cell stack system within the preset time exceeded 10 kPa.

[0100] If not, stop the airtightness test and proceed with activation;

[0101] If the pressure is 10 kPa, the sealing components of the integrated fuel cell stack system need to be tightened again and the airtightness test needs to be repeated until the pressure change of the integrated fuel cell stack system does not exceed 10 kPa before activation can begin.

[0102] Step S4, the activation step of the integrated fuel cell stack system, includes:

[0103] The integrated fuel cell stack system is sequentially loaded with current at preset current densities and operated for a certain period of time at each current density. When the single cell output voltage corresponding to any current density reaches the preset protection voltage, the integrated fuel cell stack system is continuously operated at the corresponding current density for 300 seconds until the single cell output voltage is lower than the preset protection voltage. Then, the current is gradually unloaded and activation is stopped.

[0104] The aforementioned preset current density is preferably 50 mA / cm². 2 The operating time of the fuel cell stack system after the airtightness test is preferably 30s at each current density; the aforementioned preset protection voltage is preferably 0.35V.

[0105] During the activation process of the fuel cell stack system in step S4: First, the stack temperature distribution, operating current, and voltage of the integrated fuel cell stack system are read in real time, and the real-time output power P is calculated based on the operating current and output voltage. out Then determine the output power P. out Has the rated power P been reached? e And whether the temperature distribution of the fuel cell stack meets the temperature requirements: if so, continue activation and observe the relevant operating parameters; if not, adjust the operating conditions and temperature of the integrated fuel cell stack system until the output power P is achieved. out And when the temperature distribution of the fuel cell stack meets the required conditions, the fuel cell stack system design is completed, resulting in a fuel cell stack system with high output efficiency.

[0106] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A design method for a high-power single-cell fuel cell stack system, characterized in that, The design method includes: S1, Target operating voltage based on the fuel cell system and average output voltage of a single battery V cell Calculate the required number of single cells N ; Based on the rated output power of a single battery P cell Calculate the active area of ​​a single cell S ; S2. Determine the number of single batteries. N Is it less than the first preset number? If so, then continue to determine the active area of ​​the single cell. S Is the area larger than the preset area? If yes, the length-to-width ratio of each single cell needs to be adjusted to make the current distribution inside the cell uniform; if no, only the thermal management system of the stack system needs to be adjusted to make the temperature distribution of the stack system uniform. If not, further determine whether the number of single cells is greater than the second preset number: if yes, adjust the air intake manifold arrangement of the fuel cell stack system to make its gas distribution uniform, and at the same time adjust the thermal management system of the fuel cell stack system to make the temperature distribution of the fuel cell stack system uniform; if not, proceed directly to the next step. S3, Based on the target rated power of the fuel cell system P e Calculate the hydrogen demand of the hydrogen supply system in the fuel cell stack system; and based on the target rated power... P e Calculate the air demand of the air supply system in the fuel cell stack system; S4, will N The fuel cell stack system is integrated with the hydrogen supply system corresponding to the hydrogen demand calculated in step S3 and the air supply system corresponding to the air demand. After the integrated fuel cell stack system is tested for air tightness, it is activated until the integrated fuel cell stack system reaches the preset working state, thus completing the fuel cell stack system design.

2. The design method for a high-power single-cell fuel cell stack system as described in claim 1, characterized in that, Step S4, the airtightness test includes the following steps: Nitrogen gas was introduced into the hydrogen side, oxygen side, and cooling circuit of the integrated fuel cell stack system to bring the pressure of the integrated fuel cell stack system to 150 kcal / kg. kPa The pressure is maintained for a certain period of time, and it is determined whether the pressure change of the integrated fuel cell stack system within the preset time exceeds 10. kPa : If not, stop the airtightness test and proceed with activation; If so, the sealing components of the integrated fuel cell stack system need to be retightened and the airtightness test needs to be performed again until the pressure change of the integrated fuel cell stack system does not exceed 10. kPa .

3. The design method for a high-power single-cell fuel cell stack system as described in claim 1, characterized in that, When activating the integrated fuel cell stack system in step S4, the following steps are also performed: S401: Real-time reading of the integrated fuel cell stack system's stack temperature distribution, operating current, and voltage; calculation of real-time output power based on operating current and output voltage. P out ; S402, Determine the output power P out Has the rated power been reached? P e And whether the temperature distribution of the fuel cell stack meets the temperature requirements: if yes, continue activation; if not, adjust the operating conditions and temperature of the integrated fuel cell stack system until the output power is achieved. P out The fuel cell stack temperature distribution meets the preset conditions, thus completing the fuel cell stack system design.

4. The design method for a high-power single-cell fuel cell stack system as described in claim 1, characterized in that, In step S2, the first preset number is 200; the preset area is 1000. cm 2 The second preset number is 500.

5. The design method for a high-power single-cell fuel cell stack system as described in claim 2, characterized in that, The holding time is 1 minute. min .

6. The design method for a high-power single-cell fuel cell stack system as described in claim 1, characterized in that, Step S4, the activation step of the integrated fuel cell stack system, includes: The integrated fuel cell stack system is sequentially loaded with current at preset current densities, and operates for a certain period of time at each current density. When the single cell output voltage corresponding to any current density reaches the preset protection voltage, the integrated fuel cell stack system continues to operate at that current density for a certain period of time until the single cell output voltage is lower than the preset protection voltage. Then, the current is gradually unloaded and activation is stopped.

7. The design method for a high-power single-cell fuel cell stack system as described in claim 6, characterized in that, The preset current density is 50. mA / cm 2 The fuel cell stack system, after airtightness testing, operated for 30 seconds at each current density. s .

8. The design method of a high-power single-cell fuel cell stack system as described in any one of claims 6-7, characterized in that, When the single-cell output voltage corresponding to any applied current density reaches the preset protection voltage, the integrated fuel cell stack system will continue to operate at that current density for 300 hours. s The preset protection voltage is 0.

35. V .

9. The design method of a high-power single-cell fuel cell stack system as described in claim 1, characterized in that, In step S4, the integrated fuel cell stack system also includes a cooling system. The cooling system adopts a dual-circuit cooling system. One large circulation loop is where the coolant flows out of the integrated fuel cell stack system, passes through the back pressure valve, thermostat, radiator, and water pump to dissipate heat, and then returns to the cooling channel. The other small circulation loop is where the coolant flows through the back pressure valve, thermostat, water pump, and heating cable to raise its temperature before returning to the cooling channel. This is suitable for cold starts and low-output operating conditions. In step S4, the integrated fuel cell stack system also includes a control system, which is used to monitor the operating parameters of the fuel cell stack system during operation.

10. A design system for a high-power single-cell fuel cell stack system, characterized in that, The design system for the high-power single-cell fuel cell stack system is used to implement the design method for the high-power single-cell fuel cell stack system according to any one of claims 1-9, and the design system includes: The data processing module is used to calculate the required number of single batteries. N and single cell active area S Used to calculate the hydrogen and air consumption of the fuel cell stack system under design; The result determination module is used to determine the number of single batteries. N Whether it is less than a first preset number is used to determine the active area of ​​the single cell. S Whether it is larger than the preset area is also used to further determine the number of single cells. N Is it greater than the second preset number? The fuel cell stack system parameter design module is used to design the uniformity of current distribution within each single cell; to design the uniformity of gas distribution in the fuel cell stack system; and to design the uniformity of temperature distribution in the fuel cell stack system. The fuel cell stack system testing module is used to perform airtightness tests and activation on the integrated fuel cell stack system.

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