基于响应面法的燃料电池商用车储氢系统多目标优化设计

Multi-objective optimization design of hydrogen storage system for fuel cell commercial vehicle based on response surface methodology

以某燃料电池商用车储氢系统为研究对象,为提升其抗冲击能力和满足结构轻量化设计要求,利用HyperMesh软件建立储氢系统有限元模型,对其结构进行多目标优化设计。依据GB/T 26990—2011要求对储氢系统进行仿真分析,仿真分析结果表明,氢气瓶与固定部件的相对位移小于13 mm,固定部件强度、刚度均满足国标要求;但氢气瓶受向上8 g冲击力时储氢系统框架的最大应力超过材料屈服强度。结合储氢系统结构质量分布情况,选取储氢系统框架关键部件厚度作为设计变量,以储氢系统质量和氢气瓶受向上8 g冲击力时框架最大应力为优化目标,运用最优拉丁超立方试验设计,建立响应面近似模型,最后采用第二代非支配排序遗传算法(Non-dominated Sorting Genetic Algorithm-II,NSGA-Ⅱ)进行多目标优化。结果表明,优化后储氢系统的质量减少了3.6%,氢气瓶受向上8 g冲击力时储氢系统框架最大应力减小了20.2%,满足强度、刚度要求,优化后的框架设计更加合理,储氢系统结构安全性和轻量化程度均得到提升。

Taking the hydrogen storage system of a fuel cell commercial vehicle as the research object,in order to improve its impact resistance and meet the requirements of structural lightweight design,the finite element model of the hydrogen storage system was established using HyperMesh software,and the multi-objective optimization design of its structure was carried out.The hydrogen storage system was simulated and analyzed according to the requirements of GB/T 26990—2011.The simulation results show that the relative displacement between the hydrogen cylinder and the fixed parts is less than 13 mm,and the strength and rigidity of the fixed parts meet the requirements of the national standard;but the maximum stress of the hydrogen storage system frame when the hydrogen cylinder is subjected to an upward 8 g impact force exceeds the material yield strength.Combined with the structural mass distribution of the hydrogen storage system,the thickness of the key components of the hydrogen storage system frame was selected as the design variable,with the mass of the hydrogen storage system and the maximum stress of the frame when the hydrogen cylinder is subjected to an upward 8 g impact force as the optimization objective,the optimal latin hypercube experimental design was used to establish the response surface approximation model,and finally the Non-dominated Sorting Genetic Algorithm-II(NSGA-II)was used for multi-objective optimization.The results show that the mass of the optimized hydrogen storage system is reduced by 3.6%,and the maximum stress of the hydrogen storage system frame is reduced by 20.2%when the hydrogen bottle is subjected to an upward 8 g impact force,which meets the requirements of strength and rigidity.The optimized frame design is more reasonable,and the structural safety and lightweight degree of the hydrogen storage system are improved.