Device and method for detecting uniformity of flow field of flow battery

Abstract

The invention relates to the technical field of flow batteries, in particular to a flow battery flow field uniformity detection device and a detection method, and the flow battery flow field uniformity detection device comprises a visual flow field assembly, a constant temperature water tank, a circulating pump, a pressure gauge, a thermal imager and a connecting pipeline. The visual flow field assembly, the constant-temperature water tank, the circulating pump and the pressure gauge are connected through connecting pipelines, the shooting range of the thermal imager covers the whole visual flow field area, and the temperature change of the flow field area along with time is recorded. According to the invention, the temperature change rate of the fluid at the outlet is controlled by adjusting the heating power of the water tank, and when the fluid passes through the flow channel of the electrode frame, a relatively large temperature gradient is ensured in the flow channel range of the whole visual flow field assembly. And calculating a temperature deviation value to evaluate the fluid uniformity according to the linear relationship between the temperature difference and the speed difference.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid flow batteries, and in particular to a liquid flow battery flow field uniformity detection device and detection method. Background Art

[0002] The flow uniformity of a flow battery in the electrode frame flow channel directly affects the distribution of active materials in the porous electrode area. Uneven flow field distribution can easily lead to concentration polarization and reduce battery efficiency. The flow field distribution in the electrode frame is not easy to observe and detect. Currently, commercial CFD software is mainly used for numerical simulation to calculate the optimal flow field distribution. However, there is a deviation between actual application and theoretical calculation, and there is a lack of an effective means to verify the theoretical results and optimize the structure according to actual conditions.

[0003] CN218101344U adds a tracer into the transparent flow field, irradiates the surface of the flow field area with a laser, records the position of particles in the flow field multiple times, and analyzes the captured images to measure the flow velocity. This method cannot detect the flow field distribution in the graphite felt area, the operation steps are complicated, and the tracer needs to be added each time when verifying the flow field of different structures, and the experimental accuracy is low.

[0004] CN113790868 uses thermal imaging to capture a thermal imaging image generated when gas passes through a gas-permeable layer with a catalyst and reacts with other gases to generate an exothermic or endothermic reaction. This image cannot reflect the actual flow conditions in the flow field, but rather creates a temperature difference through the reaction, which is inconsistent with the actual flow conditions.

[0005] At present, there is a lack of effective flow field uniformity detection devices and methods in the field of flow batteries. Developing an experimental equipment to evaluate the flow field uniformity of flow batteries will play a significant supporting role in improving the performance of flow battery equipment. Summary of the invention

[0006] In order to overcome the deficiencies in the prior art, the present invention provides a flow field uniformity detection device and method for a liquid flow battery. The present invention controls the rate of change of the outlet water temperature by adjusting the water tank heating power, and ensures that there is a relatively large temperature gradient in the entire flow channel of the visualized flow field component when the water passes through the flow channel of the electrode frame. According to the linear relationship between the temperature difference and the speed difference, the temperature deviation value is calculated to evaluate the fluid uniformity.

[0007] The present invention provides a flow battery flow field uniformity detection device and detection method using the following technical solutions: In the first aspect, the present invention provides a flow field uniformity detection device for a liquid flow battery, including a visual flow field component, a constant temperature water tank, a circulation pump, a pressure gauge, a thermal imager, and a connecting pipe. The outlet fluid temperature change rate is controlled by adjusting the heating power of the constant temperature water tank. The outlet of the constant temperature water tank is connected to the inlet of the circulation pump through a connecting pipe. The outlet of the circulation pump is connected to the connecting pipe and then to the pressure gauge. The connecting pipe behind the pressure gauge is connected to the inlet of the visual flow field component. The outlet of the visual flow field component is connected to the inlet of the constant temperature water tank. The shooting range of the thermal imager covers the entire visual flow field component area, and records the temperature changes of the flow field area over time.

[0008] By adopting the above technical solution, the temperature distribution can be used to replace the velocity distribution that is difficult to detect, and the uniformity of the flow field in the electrode frame can be observed in a more intuitive way on the display screen of the thermal imager.

[0009] Furthermore, the thermostatic water tank and the connecting pipes are covered with thermal insulation materials.

[0010] By adopting the above technical solution, the influence of additional heat loss on the water tank temperature can be reduced, thereby affecting the accuracy of the detection results.

[0011] Furthermore, the visualized flow field assembly includes an upper cover plate, a flow field plate, a porous electrode, a sealing gasket, a lower cover plate, and fixing bolts. The upper cover plate includes bolt holes evenly distributed on the edge of the upper cover plate, a sealing line on the contact surface between the cover plate and the flow channel, a liquid outlet, and a liquid inlet. The flow field plate includes a flow channel. The sealing gasket includes a sealing gasket groove and a sealing gasket bolt hole. The lower cover plate includes a lower cover plate groove and a lower cover plate bolt hole. The sealing gasket is positioned through the lower cover plate groove and buckled on top of the lower cover plate. The flow field plate is fixed in the sealing gasket groove, and the upper cover plate covers the flow field plate. The fixing bolts pass through the bolt holes on the upper cover plate, the sealing gasket, and the lower cover plate to fix the relative positions of the upper cover plate, the flow field plate, the porous electrode, the sealing gasket, and the lower cover plate.

[0012] By adopting the above technical solution and disassembling flow field plates with different structures, the difference in flow field uniformity between the different structures can be observed.

[0013] Furthermore, the upper cover plate in the visualized flow field assembly is manufactured using a material with high transmittance, high transparency and high thermal conductivity.

[0014] Furthermore, the shooting range of the thermal imager needs to face the visualized flow field component, and when extracting data, it is ensured that the number of extracted pixels is equal in the horizontal and vertical directions.

[0015] By adopting the above technical solution, the use of high transmittance and high thermal conductivity materials can ensure that the thermal imager can quickly capture temperature changes and reduce the measurement errors caused by the heat conduction of the upper cover itself; high transparency materials can facilitate the observation of the flow of fluid in the flow channel and reduce the detection errors caused by human factors.

[0016] The flow field plate and the lower cover plate are made of low thermal conductivity materials.

[0017] By adopting the above technical solution, the heat transfer between the flow field plates can be reduced.

[0018] In a second aspect, the present invention provides a flow field uniformity detection method for a flow battery based on a flow field uniformity detection device provided in the first aspect, comprising the following steps: S1. By changing the power of the constant temperature water tank, a relatively large temperature gradient is ensured in the entire flow channel of the visualization flow field component. The water tank is turned on to heat to the corresponding initial temperature T0, and the circulation pump is turned off. S2. Turn off the water tank heating device to keep the water tank at a constant temperature T0. The circulating pump passes through the liquid inlet at a fixed flow rate. Observe the pressure gauge reading. When the reading is basically stable, it can be considered that the fluid in the entire system has fully flowed. S3, turning on the water tank heating device to heat at the set power until the final temperature T1 is reached; S4, after turning on the water tank heating, the thermal imager takes the first image, recorded as 1, and takes one image per second, recorded as 2, 3, 4...i, and so on, where i is the total heating time t; S5. Take the medium flow direction in the porous electrode area as the vertical direction, and the direction perpendicular to it as the horizontal direction. The lower left corner of the porous electrode is the coordinate origin, the pixel points along the vertical direction are 1, 2, 3...y, and the pixel points along the horizontal direction are 1, 2, 3...x. The coordinates of each point are Pxy, and the corresponding temperature is Txy. Use a computer to extract the pixel point Pxy in the porous electrode area in the image at time i, and extract the temperature Txy of each pixel point at each time; Calculate and record the average temperature of the yth horizontal line in the vertical direction (Total y records): Calculate and record the temperature standard deviation of the yth horizontal line in the vertical direction (Total y records); Calculate the mean deviation of the temperature line (y=1,2,...), if αy<15%, the uniformity of the porous electrode at the time i meets the requirements. All moments within the total time t need to meet the uniformity requirements.

[0019] By adopting the above technical solution, the flow uniformity in the electrode frame at different times can be detected, and whether different electrode frames meet the requirements can be evaluated.

[0020] Furthermore, the shooting range of the thermal imager needs to face the visualized flow field component, and when extracting data, it is ensured that the number of extracted pixels is equal in the horizontal and vertical directions.

[0021] By adopting the above technical solution, the accuracy of extracted data can be improved.

[0022] In summary, the present invention includes at least one of the following beneficial technical effects: 1. Easy to operate, low equipment cost, and the uniformity of different structures can be detected by replacing the flow field plate; 2. Using temperature field instead of velocity field to test flow field uniformity makes the results more intuitive and easier to compare the differences in flow field distribution between different structures; 3. The structure of the visualized flow field component is the same as the actual assembly form of the flow battery. After the same medium is introduced, it is consistent with the actual flow conditions and can truly reflect the flow conditions in the flow channel of the flow battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a system diagram of the flow field uniformity detection device for a liquid flow battery of the present invention; Figure 2 It is a schematic diagram of the structure of the visual flow field component; Figure 3 It is a schematic diagram of the flow field uniformity detection method of the liquid flow battery of the present invention; Explanation of the reference numerals: 1. Visual flow field assembly; 2. Constant temperature water tank; 3. Circulation pump; 4. Pressure gauge; 5. Thermal imager; 6. Connecting pipe; 11. Upper cover; 12. Flow field plate; 13. Porous electrode; 14. Sealing gasket; 15. Lower cover; 16. Fixing bolt; 111. Bolt hole of upper cover; 112. Sealing line; 113. Liquid outlet; 114. Liquid inlet; 121. Flow channel; 141. Sealing gasket groove; 142. Sealing gasket bolt hole; 151. Lower cover groove; 152. Lower cover bolt hole. DETAILED DESCRIPTION

[0024] like Figure 1-Figure 2As shown, a flow field uniformity detection device for a liquid flow battery comprises a visual flow field component (1), a constant temperature water tank (2), a circulation pump (3), a pressure gauge (4), a thermal imager (5), and a connecting pipe (6); the temperature change rate of the outlet fluid is controlled by adjusting the heating power of the constant temperature water tank (2); the outlet of the constant temperature water tank (2) is connected to the inlet of the circulation pump (3) through a connecting pipe (6); the outlet of the circulation pump (3) is connected to the connecting pipe (6) and then to the pressure gauge (4); the pressure gauge (4) is then connected to the pipe (6) and connected to the inlet of the visual flow field component (1); the outlet of the visual flow field component (1) is connected to the inlet of the constant temperature water tank (2); the shooting range of the thermal imager (5) covers the entire visual flow field component (1) area, and records the temperature change of the flow field area over time. The visualized flow field assembly (1) comprises an upper cover plate (11), a flow field plate (12), a porous electrode (13), a sealing gasket (14), a lower cover plate (15), and fixing bolts (16); the upper cover plate (11) comprises upper cover plate bolt holes (111) uniformly distributed on the edge of the upper cover plate, a sealing line (112) on the contact surface side of the upper cover plate (11) and the flow field plate (12), a liquid outlet (113), and a liquid inlet (114); the flow field plate (12) comprises a flow channel (121); the sealing gasket (14) comprises a sealing gasket groove (141) and a sealing gasket bolt hole (142); the lower cover plate (15 ) includes a lower cover plate groove (151) and a lower cover plate bolt hole (152); the sealing gasket (14) is positioned through the lower cover plate groove (151) and buckled on the upper part of the lower cover plate (15); the flow field plate (12) is fixed in the sealing gasket groove (141), and the upper cover plate (11) covers the flow field plate (12); the fixing bolts (16) pass through the upper cover plate bolt hole (111), the sealing gasket bolt hole (142), and the lower cover plate bolt hole (152) respectively to fix the relative positions of the upper cover plate (11), the flow field plate (12), the porous electrode (13), the sealing gasket (14), and the lower cover plate (15). In the visualized flow field assembly (1), the upper cover plate (11) is manufactured using a material with high transmittance, high transparency, and high thermal conductivity to ensure that the thermal imager (5) can quickly capture temperature changes; the flow field plate (12) and the lower cover plate (15) are manufactured using a material with low thermal conductivity to reduce heat transfer between the flow field plates. The thermostatic water tank (2) and the connecting pipe (6) are covered with thermal insulation materials to reduce the influence of additional heat loss on the temperature of the water tank. The shooting range of the thermal imager (5) needs to face the visualized flow field component (1), and when extracting data, it is ensured that the number of extracted pixels is equal in the horizontal and vertical directions.

[0025] like Figure 3 As shown, a method for detecting flow field uniformity of a flow battery comprises the following steps: S1. By changing the power of the constant temperature water tank, ensure that the temperature gradient is 25°C in the entire flow channel of the visualization flow field component, turn on the water tank heating device to the corresponding initial temperature T0, and turn off the circulation pump; S2. Turn off the water tank heating device to keep the water tank at a constant temperature T0. The working medium passes through the liquid inlet at a fixed flow rate. Observe the pressure gauge reading. When the reading deviation does not exceed 5%, it can be considered that the fluid in the entire system has fully flowed. S3, turning on the water tank heating device to heat at the set power until the final temperature T1 is reached; S4, after turning on the water tank heating, the thermal imager takes the first image, which is recorded as 1, and takes one image per second, which are recorded as 2, 3, 4...i, and so on, where i is the total heating time t; S5. Take the medium flow direction of the porous electrode area as the vertical direction, the direction perpendicular to it as the horizontal direction, the lower left corner of the porous electrode facing the flow field plate as the coordinate origin, the pixel points along the vertical direction are 1, 2, 3...y, and the pixel points along the horizontal direction are 1, 2, 3...x, the coordinates of each point are Pxy, and the corresponding temperature is Txy. Use a computer to extract the pixel point Pxy of the porous electrode area in the image at time i, and extract the temperature Txy of each pixel point at each time; S6. Calculate and record the average temperature of the yth horizontal line in the vertical direction. (Total y records): S7. Calculate and record the temperature standard deviation of the yth horizontal line in the vertical direction. (Total y records); S8. Calculate the average deviation of the temperature line (y=1,2,...); like α y <15%, the uniformity of the porous electrode flow field distribution at this moment i meets the requirements; α y ≥15%, the uniformity of the porous electrode flow field distribution at this moment i does not meet the requirements; All moments within the total duration t need to meet the uniformity requirement.

[0026] Embodiment 1: This embodiment provides a flow field uniformity detection device for a liquid flow battery.

[0027] The visualized flow field assembly includes an upper cover plate, a flow field plate, a porous electrode, a sealing gasket, a lower cover plate, and fixing bolts. The upper cover plate includes bolt holes evenly distributed on the edge of the upper cover plate, a sealing line on the contact surface between the cover plate and the flow channel, a liquid outlet, and a liquid inlet. The flow field plate includes a flow channel. The sealing gasket includes a sealing gasket groove and a sealing gasket bolt hole. The other side of the sealing gasket groove is a protrusion corresponding to the depression of the lower cover plate groove and buckled on the top of the lower cover plate. The lower cover plate includes a lower cover plate groove and a lower cover plate bolt hole. The sealing gasket flow field plate is fixed in the sealing gasket groove, and the upper cover plate covers the flow field plate. The fixing bolts pass through the bolt holes on the upper cover plate, the sealing gasket, and the lower cover plate to fix the relative positions of the upper cover plate, the flow field plate, the porous electrode, the sealing gasket, and the lower cover plate.

[0028] The visualization flow field component, the constant temperature water tank, the circulation pump, the pressure gauge, and the thermal imager are connected through connecting pipes. The connecting pipe from the outlet of the constant temperature water tank is connected to the inlet of the circulation pump, the outlet pipe of the circulation pump is connected to the pressure gauge, the outlet of the pressure gauge is connected to the inlet of the visualization flow field component, and the outlet of the visualization flow field component is connected to the inlet of the constant temperature water tank.

[0029] The constant temperature water tank adjusts the rate of change of water temperature in the water tank by adjusting the power. As the water temperature rises, the temperature distribution in the flow channel of the visualized flow field component gradually shows a gradient change. After the constant temperature water tank starts to heat up, the thermal imager records the temperature change in the visualized flow field component area. The time it takes for the fluid to flow through the entire electrode frame flow channel corresponds to the temperature rise time of the constant temperature water tank.

[0030] S1. By changing the power of the constant temperature water tank, ensure that there is a relatively large temperature gradient in the flow channel of the entire visualization flow field component. Set the power of the constant temperature water tank to 500W, heat 1kg of working medium, according to Cm (T1-T0) = Pt, C is the specific heat capacity of the working medium (J / kg·℃), m is the mass of the working medium (kg), T1 is the final temperature (℃), T0 is the initial temperature (℃), P is the heating power (W), t is the heating time (s), heating from 25℃ to 50℃, it takes 3 minutes, the capacity of the electrode frame is 150mL, change the pump speed to 50mL / min, it takes 3 minutes from the inlet to the outlet of the electrode frame, so that the heating time and the temperature distribution of the entire electrode frame correspond. Turn on the water tank and heat it to the corresponding initial temperature T0, and turn off the circulating pump; S2. Turn off the water tank heating device to keep the water tank at a constant temperature T0. The initial temperature T0 is set to 25°C. The circulating pump passes through the liquid inlet at a fixed flow rate. Observe the pressure gauge reading. When the reading is basically stable, it can be considered that the fluid in the entire system has fully flowed. The pressure gauge reading deviation is less than 5% and can be considered stable. S3, turn on the water tank heating device, set the power to 500W, and heat until it reaches the final temperature T1, and the final temperature is set to 50℃; S4, after turning on the water tank heating, the thermal imager takes the first image, recorded as 1, and takes one image per second, recorded as 2, 3, 4...i, and so on, where i is the total heating time t, the total time is 3 minutes, that is, 180s; The thermal imager should face the visualized flow field component, and try to ensure that the number of pixels captured by the thermal imager in the vertical and horizontal directions in the entire flow channel area is the same; S5. Take the medium flow direction in the porous electrode area as the vertical direction, and the direction perpendicular to it as the horizontal direction. The lower left corner of the porous electrode is the coordinate origin, the pixel points along the vertical direction are 1, 2, 3...y, and the pixel points along the horizontal direction are 1, 2, 3...x. The coordinates of each point are Pxy, and the corresponding temperature is Txy. Use a computer to extract the pixel point Pxy in the porous electrode area in the image at time i, and extract the temperature Txy of each pixel point at each time; Calculate and record the average temperature of the yth horizontal line in the vertical direction (Total y records): Calculate and record the temperature standard deviation of the yth horizontal line in the vertical direction (Total y records); like α y <15%, the uniformity of the porous electrode flow field distribution at this moment i meets the requirements; α y ≥15%, the uniformity of the porous electrode flow field distribution at the moment i does not meet the requirements; all moments within the total time t need to meet the uniformity requirements.

[0031] The implementation principle of this embodiment is: by adjusting the power of the constant temperature water tank, the fluid enters the visualized flow field assembly at the same temperature change rate. When flowing through the porous electrode area, the fluid is required to penetrate the electrode at the same speed in the horizontal direction as much as possible, so that the reaction rate of the entire electrode area is consistent. When the fluid temperature gradually increases at the same rate of change, if the velocity distribution at the inlet of the porous electrode is uneven, the faster the temperature changes at the point with a larger velocity, the greater the deviation between the temperature at the point with a larger velocity on the same horizontal line and the average temperature of the entire line. Therefore, the average deviation can be used α T To characterize the temperature deviation on the same horizontal line, the larger the deviation value, the more uneven the temperature distribution on the horizontal line. The temperature is linearly related to the heating time. Within the unit time △t, the temperature difference △T in the flow direction is proportional to the flow rate Q at the inlet of the porous electrode. The unit inlet cross-sectional area A is equal, and the temperature deviation can characterize the speed deviation. By taking multiple temperature distribution diagrams that change with time with a thermal imager, after calculation and processing, the uniformity of the flow field in the flow channel when the fluid flows through the entire electrode frame under different electrode frame structures can be compared.

[0032] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A flow field uniformity detection device for a liquid flow battery, characterized in that: The invention comprises a visualization flow field component (1), a constant temperature water tank (2), a circulation pump (3), a pressure gauge (4), a thermal imager (5), and a connecting pipe (6); the temperature change rate of the outlet fluid is controlled by adjusting the heating power of the constant temperature water tank (2); the outlet of the constant temperature water tank (2) is connected to the inlet of the circulation pump (3) through a connecting pipe (6); the outlet of the circulation pump (3) is connected to the connecting pipe (6) and then to the pressure gauge (4); the pressure gauge (4) is connected to the pipe (6) and then to the inlet of the visualization flow field component (1); the outlet of the visualization flow field component (1) is connected to the inlet of the constant temperature water tank (2); the shooting range of the thermal imager (5) covers the entire visualization flow field component (1) area, and records the temperature change of the flow field area over time.

2. The flow field uniformity detection device for a liquid flow battery according to claim 1, characterized in that: The visualized flow field assembly (1) comprises an upper cover plate (11), a flow field plate (12), a porous electrode (13), a sealing gasket (14), a lower cover plate (15), and fixing bolts (16); the upper cover plate (11) comprises upper cover plate bolt holes (111) uniformly distributed on the edge of the upper cover plate, a sealing line (112) on the contact surface side of the upper cover plate (11) and the flow field plate (12), a liquid outlet (113), and a liquid inlet (114); the flow field plate (12) comprises a flow channel (121); the sealing gasket (14) comprises a sealing gasket groove (141) and a sealing gasket bolt hole (142); the lower cover plate ( 15) comprises a lower cover plate groove (151) and a lower cover plate bolt hole (152); the sealing gasket (14) is positioned through the lower cover plate groove (151) and buckled on the upper part of the lower cover plate (15); the flow field plate (12) is fixed in the sealing gasket groove (141), and the upper cover plate (11) covers the flow field plate (12); the fixing bolts (16) respectively pass through the upper cover plate bolt hole (111), the sealing gasket bolt hole (142), and the lower cover plate bolt hole (152) to fix the relative positions of the upper cover plate (11), the flow field plate (12), the porous electrode (13), the sealing gasket (14), and the lower cover plate (15).

3. The flow field uniformity detection device for a liquid flow battery according to claim 2, characterized in that: The upper cover plate (11) in the visualized flow field assembly (1) is manufactured using a material with high transmittance, high transparency and high thermal conductivity, thereby ensuring that the thermal imager (5) can quickly capture temperature changes; the flow field plates (12) and the lower cover plate (15) are manufactured using a material with low thermal conductivity, thereby reducing heat transfer between the flow field plates.

4. The flow field uniformity detection device for a liquid flow battery according to claim 1, characterized in that: The constant temperature water tank (2) and the connecting pipe (6) are both covered with thermal insulation material to reduce the impact of additional heat loss on the water tank temperature.

5. The flow field uniformity detection device for a liquid flow battery according to claim 1, characterized in that: The shooting range of the thermal imager (5) needs to be directly opposite to the visualized flow field component (1), and when extracting data, it is ensured that the number of extracted pixel points is equal in the horizontal and vertical directions.

6. A method for detecting flow field uniformity of a flow battery, characterized in that: The flow field uniformity detection is performed by the flow field uniformity detection device of any one of claims 1 to 5, comprising the following steps: S1. By changing the power of the constant temperature water tank, the temperature gradient in the flow channel of the entire visualization flow field component (1) is ensured to be 25°C. The water tank heating device is turned on to the corresponding initial temperature T0, and the circulation pump is turned off. S2. Turn off the water tank heating device to keep the water tank at a constant temperature T0. The working medium passes through the liquid inlet at a fixed flow rate. Observe the pressure gauge reading. When the reading deviation does not exceed 5%, it can be considered that the fluid in the entire system has fully flowed. S3, turning on the water tank heating device to heat at the set power until the final temperature T1 is reached; S4, after turning on the water tank heating, the thermal imager takes the first image, which is recorded as 1, and takes one image per second, which are recorded as 2, 3, 4...i, and so on, where i is the total heating time t; S5. Take the medium flow direction of the porous electrode area as the vertical direction, the direction perpendicular to it as the horizontal direction, the lower left corner of the porous electrode facing the flow field plate as the coordinate origin, the pixel points along the vertical direction are 1, 2, 3...y, and the pixel points along the horizontal direction are 1, 2, 3...x, the coordinates of each point are Pxy, and the corresponding temperature is Txy. Use a computer to extract the pixel point Pxy of the porous electrode area in the image at time i, and extract the temperature Txy of each pixel point at each time; S6. Calculate and record the average temperature of the yth horizontal line in the vertical direction. ; S7. Calculate and record the temperature standard deviation of the yth horizontal line in the vertical direction. ; S8. Calculate the average deviation of the temperature line (y=1,2,...); like α y <15%, the uniformity of the porous electrode flow field distribution at this moment i meets the requirements; α y ≥15%, the uniformity of the porous electrode flow field distribution at this moment i does not meet the requirements; All moments within the total duration t need to meet the uniformity requirement.

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