Multi-parameter optimization of serrated fins in plate-fin heat exchanger based on fluid-structure interaction

Abstract

The comprehensive performance of serrated fins in plate-fin heat exchanger (PFHE) under cryogenic condition is analyzed based on fluid-structure interaction (FSI). On the foundation of response surface methodology (RSM) and sobol sensitivity analysis, the effects and interaction effects of fin height, fin space, fin thickness and fin interrupted length on flow resistance, heat transfer and stress are analyzed quantitatively. The contour results show that, compared with the pressure stress, the thermal stress is very low and the high stress mainly locates in the regions of keen-edged geometric structure, and the highest stress is in the regions connecting two rows of fins. The sensitivity analysis results show that the effect of fin interrupted length on j factor is the most significant and the interaction effect of fin space and fin interrupted length is the most obvious. The effect of fin thickness on f factor or the maximum stress is the most significant and the interaction effect of fin thickness and fin space is the most obvious. By implementing Multi-Objective Genetic Algorithm (MOGA), the serrated fin structure is optimized comprehensively and a set of Pareto-optimal points are obtained. Compared with the original structure, the JF factor of optimized structure 1, 2 and 3 increases by 8.8%, 4.4% and 9.6%, and the maximum stress decreases by 29.6%, 42.3% and 21.1%, respectively. The MOGA based on RSM offers theoretical guidance for design optimization of PFHE.