Structural Optimization of Shell-Tube Heat Exchanger with Helical Baffles Based on Fluid-Structure Interaction

Helical angle and baffle overlap proportion as two variables were used in structural optimization of shell-tube heat exchanger with helical baffles, and a second polynomial regression response surface method combined with genetic algorithm was applied. The study was based on fluid-structure interaction theory considering thermal structural performance. The results show that the heat transfer coefficient per pressure drop increases first and then decreases with the increase of helical angle, and it decreases with the increase of baffle overlap proportion when flow velocity ν = 1.5 m·s^-1. Helical angle is more sensitive than baffle overlap proportion for flow and heat transfer. The maximum shear stress increases with the increase of helical angle, but it is almost unaffected by baffle overlap proportion. The optimization objectives are maximization of heat transfer coefficient per pressure drop and minimization of maximum shear stress within allowable stress ranges, and three optimal structures are obtained. The optimal results show that the heat exchanger coefficient per pressure drop is increased by 14.1% on average and the maximum shear stress is reduced by 4.1% on average. These results provide theoretical guidance for industrial design of shell-tube heat exchanger with helical baffles.