Abstract:

In this work, the influence of the single cell number on output performance, cell uniformity and thermal management of high temperature polymer electrolyte membrane fuel cells stack (HT-PEMFCs stack) was investigated by combining numerical simulation and experimental method. The numerical simulation results show that when the number of single cell of the stack increases from 10 to 60, the average single cell voltage decreases slightly from 0.6414 V to 0.6404 V, and the voltage range between single cells increases from 1.8 mV to 6.5 mV. The average working temperature between single cells increases from 431.01 K to 433.90 K, and the range of the working temperature of each single cell increases from 6.95 K to 10.22 K. The numerical simulation results indicate that with the increase of the number of single cells in the stack, the average single cell voltage of the stack has a slight downward trend, and the voltage range between the single cells has increased, the voltage consistency between the single cells has decreased. Furthermore, the temperature difference between the single cells has increased, the uniformity of the average temperature of the single cell itself has also decreased, and the difficulty of the thermal management of the stack has increased. Under the guidance of the simulation results, HT-PEMFCs stacks with 30, 60, and 120 single cells were assembled and evaluated. Under the operating condition of dry hydrogen/air gas and the discharge current of 33 A, the average single cell voltage of fuel cell stacks with 30, 60, and 120 single cells was 0.6566, 0.6548, and 0.6552 V, respectively. The single cell range increased from 24 mV to 59 mV, which showed good consistency with the simulation results and verified the effectiveness of the simulation results. Under the operating condition of dry hydrogen/air gas with the metering coefficient of 1.5/2.5, the fuel cell stacks show excellent output performance. The output power of the three stacks reaches 1.35, 2.64, and 5.28 kW at 80 A discharge current, respectively. The results of this work provide theoretical and practical guidance for the design, assembly and evaluation of kW-scale high-temperature polymer electrolyte membrane fuel cell stacks.

Key words: fuel cells, kW-scale stack, mathematical modeling, experimental validation, high temperature polymer electrolyte membrane, cell uniformity

摘要：

以大尺寸单电池(有效工作面积为165 cm²)和多片单电池组装而成的电堆为研究对象，通过数值模拟和实验测试相结合的方法探究了单电池数量对高温聚合物电解质膜燃料电池堆输出性能、单池一致性和热管理的影响。模拟结果显示，当电堆的单池数量从10片增加至60片时，平均单池电压从0.6414 V略微降低至0.6404 V，且单池之间电压极差从1.8 mV增加至6.5 mV；单池间的平均工作温度从431.01 K升高至433.90 K，且每单池自身工作温度的极差从6.95 K增加至10.22 K。表明随着电堆单池数量的增加，电堆的平均单池电压呈轻微下降趋势，且单池间电压极差变大，单池电压一致性有所下降，单池间的温差变大，其单池自身的均温一致性也有所降低，电堆热管理难度增加。在模拟结果的指导下分别组装了30、60和120片单池的高温膜燃料电池堆，在氢/空干气、33 A的恒流放电条件下，测得30、60和120片单池电堆的平均单池电压分别为0.6566、0.6548和0.6552 V，单池极差从24 mV增加到59 mV，与模拟结果显示出良好的一致性，验证了模拟结果的有效性。在氢/空干气计量系数为1.5/2.5的操作条件下，展示出了优异的输出性能，三个电堆在80 A电流放电时的输出功率分别达到1.35、2.64和5.28 kW。研究结果可为千瓦级高温聚合物电解质膜燃料电池堆的设计和组装测试提供理论和实践指导。

关键词: 燃料电池, 千瓦级电堆, 数学模拟, 实验验证, 高温聚合物电解质膜, 电池一致性