Optimization Of Impeller Installation Position And Blade Structure Parameters Of Backward Centrifugal Fan

Backward centrifugal fan is widely used in industrial production and people’s life.With the development of society,people put forward higher requirements for the aerodynamic performance of backward centrifugal fan.Based on a certain type of backward centrifugal fan,this paper adopts the method of combining numerical simulation and experiment,by changing the position of impeller in the volute and some structural parameters of blade,the design purpose of maintaining the full pressure of the fan and improving the efficiency of the fan is achieved.The main research work of this paper is as follows:(1)According to the characteristics of a backward centrifugal fan,the performance of the original fan is predicted by using the appropriate numerical simulation method,and the feasibility of the numerical simulation method is verified by comparing with the experimental data.Finally,the internal flow field is analyzed,and the shortcomings of the original fan in structure are pointed out.(2)The influence of the relative position of impeller and volute on the performance of backward centrifugal fan was studied by orthogonal test.The results show that the proper installation position of the impeller in the volute can enhance the adaptability between the volute and the impeller,improve the flow field in the volute channel,reduce the energy loss of the air flow in the volute channel,and improve the aerodynamic performance of the fan.The total pressure and efficiency of the fan are increased by 2.65% and 1.93% respectively.(3)Through the comparative analysis of aerodynamic performance and internal flow field of a variety of fans with different blade structure parameters,the effects of blade airfoil,installation angle,number of blades and inclined blades on the performance of backward centrifugal fan are studied.The results show that on the basis of the optimal installation position of the impeller,adjusting some structural parameters of the blade properly can improve the internal flow field of the impeller and volute,reduce the flow loss,and further improve the aerodynamic performance of the fan.Finally,the total pressure of the fan under the design condition is increased by 4.29%,and the efficiency is increased by 8.78%.