Effect of flow maldistribution on the optimal design of plate heat exchanger using constrained multi objective genetic algorithm

Abstract

In this study, thermal and hydraulic optimization of plate heat exchanger is presented. In the thermal modeling of the plate heat exchanger, the effects of flow maldistribution for each side are also considered. A multi objective optimization is implemented based on the NSGA-II (Non-dominated Sorting Genetic Algorithm-II) algorithm to obtain the optimal trade-off (Pareto front) between effectiveness and pressure drop of hot side. The optimization variables in this study are considered as chevron angle, the number of plates, corrugation depth, corrugation pitch, horizontal distance of ports, vertical distance of ports, and port diameter and the goal is to achieve maximum effectiveness and minimum pressure drop. In addition, operational and geometrical constraints are also considered in the optimization procedure in order to take the advantage of the standard design and achieve feasible solutions. Next, a case study is presented to identify conflicting thermal-hydraulic behavior of plate heat exchanger. The results are reported as a set of multiple optimum solutions called ʺPareto optimal solutionsʺ. Moreover, the effect of changing these parameters on the optimal design is also presented and discussed in detail.