高速列车车体隔热性能分析与优化

Analysis and Optimization of Thermal Insulation Performance of High-Speed Train Body

以某高速列车为例,通过对车体四种典型截面拉伸体进行有限元仿真得到整车的传热系数为0.948 W/(m^(2)·K),与同类型车体的实验值相比误差仅为8.8%。在对车体典型的平壁结构和冷桥结构分析中发现铝型材空腔的空气没有对隔热起到显著的作用,原因是型材内部腹板处存在热短路。通过减少腹板数量和将腹板更换为CFRP材料优化承载结构隔热性能后再进行仿真分析,结果表明:减少一对腹板对热阻没有较大影响,而将其更换为CFRP材料后平壁结构的传热系数降低了52%,冷桥结构的传热系数降低了63%。

Taking a high-speed train as an example,the heat transfer coefficient of the whole vehicle is 0.948 W/(m^(2)·K)by finite element simulation of four typical cross-sectional extrusions of the car body,and the error is only 8.8%compared with the experimental value of the same type of car body.In the analysis of the typical flat wall structure and cold bridge structure of the car body,it was found that the air in the cavity of the aluminum profile did not play a significant role in the thermal insulation due to the thermal short circuit in the internal web of the profile.By reducing the number of webs and replacing the webs with CFRP materials to optimize the thermal insulation performance of the load-bearing structure,the simulation results show that the reduction of a pair of webs has no great effect on the thermal resistance,and replacing them with CFRP materials reduces the heat transfer coefficient of the flat wall structure by 52%and the heat transfer coefficient of the cold bridge structure by 63%.