自由呼吸式质子交换膜燃料电池的研究--三维数值分析阴极流道结构对电池性能的影响

由于阴极气体通道中的自然对流和传热传质特性与电化学反应的耦合,阴极流道对自由呼吸式质子交换膜燃料电池(PEMFC)的性能有着极大的影响。合理的流道设计有助于氧气质量传输和流道中水的合理分布,有效提高电池性能。根据自由呼吸式燃料电池的内部传输现象,建立了三维的流体传动,传热传质和电化学模型,基于计算流体力学(CFD)数值计算方法,利用商业CFD计算软件三维求解了Navier-stokes方程,同时利用用户自建的子程序对电化学模型及水的传输模型进行了求解,二者相互耦合。模型计算经过实验进行了验证。针对不同阴极流道开口率对实际电池性能的影响,计算了电池的内部参数。通过分析结果,提出了这种电池操作条件和设计下的最佳开口率。

Effect of cathode channel on an air-breathing proton exchange membrane fuel cell (PEMFC)

The configuration of cathode channel plays a great role in the performance of air-breathing PEMFC due to the strong interaction of fluid dynamics, heat transfer and electrochemical reactions. Appropriate channel design could be helpful for oxy- gen and water transport in the cell, so as to decrease the concentration limitation and membrane ohmic resistance. To optimize cathode channel and predict the performance of an air-breathing PEMFC, a three-dimensional mathematic model was develo- ped based on the phenomena inside cell. The governing equations for fluid dynamic and heat transfer are solved in a commer- cial CFD tool STAR-CD using finite volume method, and the equations accounting for electrochemical reaction and water tra- nsfer through membrane are solved simultaneously by user sub-routine in the form of FORTRAN code based on finite differ- ence technique. The calculations for three different channel open ratio are carried out to find the optimal channel open ratio.