Simulation And Optimization Of Axial Flow Fan Shroud And Duct

In intensive and large-scale livestock and poultry breeding,the quality of the environment directly affects the prevention and control of livestock and poultry diseases,healthy production,product quality and safety,and the sustainable development of livestock and poultry enterprises.Axial flow fan for livestock and poultry house is an important equipment to adjust environmental quality.Improving its performance is of positive significance to improve the environment and economic benefits of livestock and poultry house.Therefore,this paper takes the 56 inch axial flow fan for livestock and poultry house produced by Jiangxi Zengxin Technology as the original model for three-dimensional modeling,and improves the performance of the fan by optimizing the structure of fairing and wind tube.(1)Solid Works software is used to establish the overall model of the fan,in which the impeller model is reconstructed in the software after 3D scanning.Then,the original model is numerically simulated by ANSYS FLUENT software and its flow field characteristics are analyzed.The four important structural parameters,including the opening and closing angle of the fairing,the inclined length of the fairing,the blade tip clearance and the installation position of the fairing relative to the impeller,have a significant impact on the flow field characteristics,air volume and energy efficiency ratio of the fan.(2)The single factor analysis of the above four structural parameters is carried out.Within the selected opening and closing angle of the fairing,the fan air volume and energy efficiency ratio increase with the opening and closing angle α The increase of showed a decreasing trend.Within the selected inclined length range of fairing,the air volume and energy efficiency ratio of axial flow fan first rise and then decline with the increase of inclined length l,and its peak value is in the range of 1100 mm ～ 1300 mm.In the selected range of tip clearance,the air volume and energy efficiency ratio of axial flow fan show a continuous decreasing trend with the increase of tip clearance d.Within the installation distance of the selected fairing relative to the impeller,with the impeller installation closer to the inlet of the fairing,the air volume and energy efficiency ratio of the axial flow fan increase first and then decrease,and its peak value is in the range of s =-30 mm to s =40mm.(3)It is further optimized by four factor and three-level orthogonal test,when the opening and closing angle of the fairing is obtained α= 7 °,the inclined length of the fairing is L = 1300 mm,the blade tip clearance is d = 5mm,and the installation distance of the fairing relative to the impeller is s = 10 mm,the fan performance is the best,which increases the fan air volume and energy efficiency ratio by 13.60% and 18.87%respectively.Then the accuracy of the numerical simulation is verified by wind tunnel test to prove the feasibility of the optimization results.In this paper,the flow field of axial flow fan is analyzed,and the fairing and wind tube are optimized according to the analysis results,so as to improve the aerodynamic performance of the fan,which provides a theoretical basis for the development and optimization of axial flow fan for livestock and poultry houses in the future,and it is of great significance to improve the environment of livestock and poultry houses and save energy consumption at the same time.