质子交换膜电解池二维两相流综合模拟研究

TWO-DIMENSIONAL COMPREHENSIVE SIMULATION STUDY OF TWO-PHASE FLOW IN PROTON EXCHANGE MEMBRANE ELECTROLYZER CELL

建立一个二维、非等温质子交换膜电解池两相流稳态模型,研究不同电压下电解池膜电极组件(MEA)中温度、液态水饱和度、膜态水分布以及温度、液态水饱和度和膜厚对质子交换膜电解池性能的影响,并通过实验验证模型的可靠性。实验结果表明:即使忽略接触电阻,膜润湿性较好,高电压(2.0 V)下欧姆损失占比仍可达到34.7%;随着电压的增大,极化损失的主导部分由活化损失变为欧姆损失,且传质损失占总极化损失的比例最小;当电压较小时,膜水含量是质子交换膜(PEM)电导率的主要影响因素,当电压较大时,温度是PEM电导率的主要影响因素。升高温度、增加液态水饱和度及降低膜厚均能有效提高电解池的性能。

In the study,a two-dimensional,non-isothermal,two-phase flow steady-state model of proton exchange membrane(PEM)electrolyzer cell is established to study the distribution of temperature,liquid water saturation and membrane water content at different voltages in the membrane electrode assembly of electrolyzer cell.Besides,the effects of temperature,liquid water saturation and membrane thickness on the performance of electrolyzer cell are investigated.The reliability of the model is validated by experimental results.The results show that although the contact resistance is neglected and the membrane wettability is good,the percentage of the ohmic loss can still reach up to 34.7%at high voltage(2 V).As the cell voltage increases,the dominant factor of the overpotential changes from activation loss to ohmic loss,and the loss of mass transfer accounts for a minor proportion of the total overpotential.When the voltage is lower,the membrane water content is the main factor affecting the PEM conductivity,and when voltage is greater,the temperature becomes the main factor to determine the PEM conductivity.The performance of the PEM electrolyzer cells can be effectively improved by increasing the temperature and the liquid water saturation,or decreasing the membrane thickness.