Study On The Aerodynamic Performance Optimization Of The Impeller Of The Helium Circulator Of HTR-PM

In order to meet the energy demand of China's social development and the low-carbon demand of development,nuclear energy,as an efficient and clean energy which can replace fossil energy,has been paid more and more attention in China.With the rapid development of nuclear power industry,the High Temperature Reactor Pebbled Modules(HTR-PM)designed by China,as the fourth generation of nuclear reactor,has very good safety and economy.The helium circulator of HTR-PM is one of the key devices to ensure these characteristics.Its function is to drive the helium in the primary system as the coolant to circulate and flow to take away the heat of the reactor core,so as to ensure the safety of the HTR-PM.Therefore,if the efficiency of the helium circulator can be improved,the economy and safety of the HTR-PM will be improved.In this paper,Computational Fluid Dynamics(CFD)method is used to study the aerodynamic performance of the impeller of the helium circulator of HTR-PM.By modifying the structural parameters and running speed of the impeller,using the performance parameters such as the total efficiency of the impeller,outlet pressure rise,shaft power,etc.to study the internal flow field of the impeller,the influence of the change of the impeller parameters on the aerodynamic performance of the helium circulator is analyzed and summarized.Then by using NSGA-II,one of the methods multi-objective genetic algorithm,and using the loss of the impeller as the optimization objective,the structural parameters of the impeller,such as the installation angle of the blade outlet,the number of blades,the thickness of the blade,the diameter of the impeller outlet,and the rotation speed of the impeller as the optimization variables,to optimize the impeller of the helium circulator.Then two groups of optimization results are modeled and numerical simulation is carried out.The results show that the optimized impeller improves the static pressure rise and the total efficiency of the helium circulator.According to the priority principle of improving efficiency,choose one of them as the final optimization scheme.Compared with the prototype impeller,the impeller structure of the final optimization scheme increases the installation angle of blade outlet by 4.7°,the number of blades increases by 1,the thickness of blade decreases by 1mm,the diameter of impeller outlet decreases by 28 mm,and the speed of impeller increases by 169 rpm.The conclusion is that the impeller of the optimized scheme increases the static pressure rise of the helium circulator by 10.70% and the total efficiency by 1.20%.