燃/滑油微小通道换热器封头结构的优化设计

The flow characteristics of side-entry head structure of fuel/lubricating-oil micro-channel heat exchanger were studied. Four geometric constraints and two objective function optimization models were constructed based on non-dominated sorting genetic algorithm (NSGA-Ⅱ). The effects of the shape of the head shell, the position and pitch of the baffle and the size of baffle aperture on the flow distribution characteristics and pressure loss in the header were studied. Firstly, the sample space was built, and the functional relationship between the geometric constraints and the objective function was established based on the response surface method. Then, the NSGA-Ⅱ was used to carry out a global search, and the Pareto front and optimal solution candidate points of different working conditions were obtained. Finally, the comprehensive characteristics of the candidate points were compared and analyzed to screen out the optimal structure. The results showed that the pressure loss can be effectively suppressed by lowering the header depth, and the flow distribution characteristics can be greatly improved by adding diversion structure, but at the expense of increasing the pressure loss. The effects of header structure parameters on flow distribution characteristics and pressure loss were higher than flow velocity. Two header structures were screened through multi-objective optimized design, showing good applicability to different working conditions.