Numerical Simulation and Structure Optimization of Heat Pipe Heat Exchanger Based on Response Surface Method

The Heat Pipe Heat Exchanger (HPHE) is the most important component between the Heat Pipe Reactor (HPR) and the Brayton cycle power generation system. Fins are usually used to enhance its heat transfer performance, and the geometric parameters are critically influenced. In this paper, the numerical simulation and geometric structure optimized design of a finned HPHE are carried out based on the response surface method and genetic algorithm. The fin density, height, and thickness are considered as input variables, and the heat transfer power Q and pressure drop P are optimized variables. The thermo-hydraulic performance of HPHE was evaluated and simulated by the Box-Behnken design method and Computational Fluid Dynamics (CFD) software Fluent and optimized by the nondominated sorting genetic algorithm-II (NSGA-II). Compared with the circular tube, when the density n = 8, the height h = 2.9 mm, and the thickness t = 3 mm, the optimized HPHE has better comprehensive thermo-hydraulic performance than the original design. And the optimized HPHE demonstrates robust heat transfer capability and high performance under all working conditions.