Study Of Blade Profile In Backward Centrifugal Fan Based On The 3-D Numerical Simulation

As a kind of impeller mechanical equipment of gas powered,the centrifugal fan is widely used in many industries,such as steel,cement,electricity,coal,petrochemical and waste water treatment.But due to the influence of various factors,the operation efficiency of the centrifugal fan is often not ideal;the actual power consumption is too large.In recent years,it has been recognized that enhancing energy-efficiency of utilization can play a major role in reducing energy consumption.Therefore,designing a centrifugal fan with high efficiency is of great importance for energy conservation.In order to improve the efficiency of centrifugal fan,a centrifugal fan(type 4-79-7C)provided by the cooperation unit is studied in this thesis.Numerical simulation is employed to research the inner flow field of centrifugal fan and the blade is optimized based on the analysis result.The main research contents and results of this thesis are as follows:(1)Numerical simulation is employed to research the centrifugal fan(type 4-79-7C)and the influence of different blade inlet angles on the performance of the centrifugal fan are studied.The research results show that,compared with the original model,the static pressure efficiency of the optimized model which the blade inlet angle of is 6°is increased,and the condition of the flow which is closer to the shroud is worse.It provides the basis for the subsequent optimization of blade.(2)The velocity distribution method and loading distribution method are used to design the blade profiles of the centrifugal fan.Then the performance of the original model and the optimized model is compared.The results show that the performance of the centrifugal fan can be improved significantly by the two methods,and both the pressure and the efficiency have been increased.(3)Further design is carried out based on the research results of the first two parts and the model used in the third part is model C which is designed in the second part.A way is proposed to improve the flow of shroud.Then 3D blades are designed by change the blade velocitydistribution of the shroud.The simulation results show that the efficiency of the optimized model is improved.