Numerical optimization of baffle configuration in header of heat exchanger using sequential approximate optimization

Abstract To enhance the performance of heat exchangers (HEs), it is important to make the flow uniform and is to reduce the pressure. To achieve them simultaneously, baffle with small holes is often installed in the header of HEs, but the configuration is completely determined by the engineer's experience. In this paper, the baffle configuration under 2D fluid flow is optimized so as to minimize the flow nonuniformity and the pressure drop. Therefore, multi-objective design optimization is performed. The computational fluid dynamics (CFD) is so intensive that sequential approximate optimization that response surface is repeatedly constructed and optimized is adopted to identify the pareto-frontier. It is found from the numerical result that the optimal baffle configuration can drastically improve the flow nonuniformity and the pressure drop, compared to the conventional one. Compared to the conventional configuration, 34% improvement of the flow nonuniformity and the 23 % improvement of the pressure drop are achieved by the design optimization. In addition, the size of large vortex can drastically be reduced. In particular, it is clarified that the inclined baffle plays an important role for improving the flow nonuniformity.