CFD simulation and optimization study on the shell side performances of a plate and shell heat exchanger with double herringbone plates

•The Influence of corrugation parameters on the thermal–hydraulic performance of the shell side of the heat exchanger is analyzed.•The maximum heat transfer efficiency is obtained at β = 60°, which is significantly different from that of PHE.•The optimal design parameters β, λ, and b obtained by the CFD-ANN-NSGA II method are 33.1°, 11.8 mm, and 7.5 mm.•The accuracy of the numerical simulation method is verified by PIV experiments. The purpose of this study is to investigate the flow and heat transfer performance of the plate and shell heat exchanger (PSHE) with double herringbone plates under low temperature difference conditions, while introducing the CFD-ANN-NSGA II method to optimize the corrugated parameters. A PIV experimental bench is built to validate the flow field distribution in the shell side, and the average velocity error between simulation results and experiment results is 2.93%, with a maximum relative error of 13.24%, confirming the accuracy of the turbulence model and numerical method. The flow characteristics analysis and parameter study are conducted within the research scope. For the considered parameters, i.e., the corrugation angle β, corrugation depth b, and corrugation pitch λ, the maximum heat transfer efficiency is achieved when β is 60°. Moreover, the corrugation angle has the greatest impact on both pressure drop and heat transfer performance. β = 30°, λ = 7.4 mm, and b = 7.5 mm are the best performance indicators for the respective operating conditions. Using CFD results as samples, the R2 of ANN training is greater than 0.99, and the multi-objective optimization yields the best configuration of β, λ, and b, which are 33.1°, 11.8 mm, and 7.5 mm, respectively, with the optimal thermal–hydraulic performance.