Structural Optimization of Shell-and-Tube Heat Exchanger Shell Side Based on Numerical Simulation and Response Surface Methodology

To enhance the shell-side heat transfer performance of shell-and-tube heat exchangers while balancing flow resistance, this study investigates a small-scale shell-and-tube heat exchanger. Using numerical simulation, it systematically analyzes the effects of structural parameters—including baffle spacing, baffle notch width, and tube-to-tube spacing—on shell-side flow and heat transfer characteristics. A three-dimensional numerical computational model based on the Realizable k-ε turbulence model was established and validated against experimental data. The simulation error for air outlet temperature was controlled within 6.5%, demonstrating good model reliability. Results indicate that increasing the number of baffles from 3 to 7 raised the average shell-side heat transfer coefficient by 23.63%, but significantly increased pressure drop. increasing the baffle notch width from 0.2D to 0.5D reduced the heat transfer coefficient by an average of 9.6%; increasing the tube spacing from 26 mm to 42 mm decreased the heat transfer coefficient by an average of 11.61%. Multi-parameter interaction analysis based on the response surface method indicates that the arrangement spacing and notch width of baffles exert the most significant influence on both the heat transfer coefficient and pressure drop.