Optimization of thermal and flow characteristics of plate heat exchanger with variable structure parameter

The plate heat exchanger is an efficient and compact heat exchanger, which has the advantages of high heat transfer coefficient and compact structure compared with other heat exchangers. The CFD simulation, radial basis function and multi-objective optimization are used to determine the optimal plate heat exchanger structure. Because there are two conflicting objectives that heat transfer coefficient j and friction coefficient f, the multi-objective genetic algorithm (MOGA) is selected, and the approximation model is obtained with radial basis function (RBF). The optimization results showed that heat transfer factor j increased by 26.9%, while friction factor f decreased by 25%, suggesting enhanced convective heat transfer and significantly reduced flow resistance. In each field of the longitudinal section, the optimized model velocity field increases by 0.01%, the pressure field decreases by 40%, and the temperature decreases by 2.5%. Then, the internal flow field is qualitatively compared from the aspects of field synergy angles and verified the rational optimization results. In this paper, multi-objective optimization method and CFD simulation are used to predict the structure of heat exchanger, rather than through the expensive and time-consuming experiment. This optimization method can save the design expense and time for the designer to design the plate structure that meets the requirements. This kind of multi-objective optimization design combined with simulation can provide a precise design method for designers.