关键词:
质子交换膜燃料电池
梯形挡板流道
正交实验
熵值法
方差分析
多目标优化
摘要:
质子交换膜燃料电池(PEMFC)性能指标多样,通过多目标优化可以提升PEMFC的综合性能。本文综合运用正交实验(OEM)、方差分析(ANOVA)以及熵值法(EWM)与人工神经网络(ANN),提出了一种综合评价PEMFC性能的多目标优化方法。首先,选择几个常用的PEMFC性能指标,针对PEMFC的几何参数和操作参数初步选择对PEMFC性能有影响的参数设计正交实验,随后使用COMSOL软件模拟计算获取对应工况下各个性能指标结果。通过方差分析筛选出对目标有显著影响的变量,可以达到减小优化空间、提高优化效率的目的。其次,根据显著变量再次进行正交实验,获取优化空间中具有全局代表性的数据集,随后提出了代表PEMFC综合性能(CP)的表达式,通过熵值法分析了CP中多目标的权重,进一步计算出CP的数学表达式并作为适应度函数。最后将ANN作为计算CP的代理模型,对显著变量进行优化,继而得到一种最优的参数组合使得对应的CP值达到最大,从而最大限度地提升PEMFC的综合性能。利用该方法对梯形挡板流道模型进行了多目标优化分析,在0.4 V电压下,优化后流道模型相比较基础流道模型而言,功率密度和净功率分别提升了53.71%和53.70%,然而阴极压降却仅仅只上升了7.93 Pa,氧气不均匀度降至0.19。上述方法可有效降低优化计算时间,对今后PEMFC的结构设计与操作运行具有一定的指导意义。Proton exchange membrane fuel cell (PEMFC) has various performance indicators, and the comprehensive performance of PEMFC can be improved by multi-objective optimization. In this paper, a multi-objective optimization method for comprehensively evaluating the performance of PEMFC is proposed by comprehensively applying orthogonal experiment (OEM), analysis of variance (ANOVA), and entropy value method (EWM) with artificial neural network (ANN). Firstly, several commonly used PEMFC performance indexes are selected, and orthogonal experiments are designed for the parameters that have an impact on the PEMFC performance by initially selecting the geometrical and operational parameters of the PEMFC, and then simulations are performed using COMSOL software to obtain the results of the performance indexes under the corresponding working conditions. Through the analysis of variance to screen out the variables that have a significant impact on the target, it can achieve the purpose of reducing the optimization space and improving the optimization efficiency. Secondly, orthogonal experiments were conducted again according to the significant variables to obtain a globally representative data set in the optimization space. Subsequently, an expression representing the comprehensive performance (CP) of PEMFC was proposed, and the weights of multiple objectives in the CP were analyzed by entropy metho