板翅式换热器波纹翅片性能数值模拟及其优化

Numerical simulation and optimization on performance of wavy fins in plate-fin heat exchangers

为提升板翅式换热器的综合性能,采用数值模拟方法,研究分析了翅片结构参数对板翅式换热器波纹翅片的流动传热特性和承压能力的影响。研究结果表明:波纹尺度对换热性能和流动阻力影响最大,而翅距和翅厚对翅片承压能力影响最大;波纹翅片结构参数主要通过改变换热面积和流速,以及加剧流体内部搅混来改变流动换热特性,其中加剧流体内部搅混为主要影响途径。结合动态Kriging响应面和遗传算法进行结构优化得到3组翅片结构参数,相较于常用结构,优化后翅片JF因子可提升5.8%~7.8%,而最大应力可降低7.3%~22.8%。研究结果可以为板翅式换热器波纹翅片的优化设计提供理论指导。

In order to improve overall performance of plate-fin heat exchangers(PFHE),effects of fin structural parameters on flow and heat transfer characteristics and pressure bearing capacity of wavy fins in PFHE were analyzed by numerical simulation.The results show that wavy scale has the greatest effects on the heat transfer performance and flow resistance,while the fin spacing and thickness have the greatest effects on bearing capacity.The fin structural parameters affected the flow and heat transfer characteristics by changing heat transfer area and velocity,and also intensifying the internal mixing of the fluid,with the last one as the main factor.The structural parameters of three fin groups were obtained with a dynamic Kriging response surface method and genetic algorithm.Compared with common structures,the JF factor of the optimized structure can be improved by 5.8%~7.8%,while the maximum stress can be reduced by 7.3%~22.8%.The results can provide theoretical guidance for the optimal design of wavy fins in PFHE.