Structure Optimization of Bottom Nozzle for Flow Resistance Filtration-Bearing Performance

To improve the comprehensive performance of the bottom nozzle, including coolant pressure drop, debris filtration, and load-bearing of structure, a multi-objective optimization approach was proposed to optimize the key dimensional parameters of the bottom nozzle with the goal of coolant pressure drop and debris filtration efficiency. Based on the approach, size optimization was conducted using the hexagonal bottom nozzle as an example. The results showed that the pressure drop and filtration efficiency were optimized by 12.5% and 6.3%, respectively. Meanwhile, the maximum stress was reduced by 14.0%, confirming a significant enhancement of the comprehensive performance. Furthermore, the multi-objective optimization approach is universal for the structural optimization of various types of bottom nozzle to improve its comprehensive performance.