Design Theory And Application Of Overhung Type Multistage Centrifugal Fan

Centrifugal fan is widely used in various industries,is the important industrial production equipment.It occupies an important position in the development of social production.At present,there is still a big gap between the domestic and abroad on the development of research level.The domestic production of fan can not fully meet the production needs of various industries,and the lack of serialized design capabilities limited the development of the fan industry.In order to overcome this limitation,this paper studies the seriation design theory and application of cantilevered multistage centrifugal fan.This paper has established the seriation design theory and method for cantilevered multistage centrifugal fan on the basis of predecessors’ research results,and completed the structure parametric design software for this type fan.By analysis the test data,build a loss model witch is conform to the flow characteristics of this type fan.The losses include the flow loss in the impeller,loss in the bends and refluxers,loss in the volute,loss in the inlet and outlet chambers,and the impact losses in changing conditions.Compiled the fan performance prediction software conversion by using MATLAB software platform,and predicted the performance of multiple models of fans in the performance prediction software.This paper has compiled full three-dimensional numerical simulation for the fan by using commercial CFD numerical calculation software ANSYS,and use CFD-POST for post-processing,which shows that the fan’s internal flow field is reasonabl.And studied the effect of the change of structural parameters on fan performance,which is reducing the outlet geometry angle of the reflux device blade will reduce the pressure and power of the fan,and decrease the inlet geometry angle of the impeller blade will cause the highest efficiency point of the fan to move in the direction of small flow and the pressure-flow curve of the fan will become more gentle.These research results has practical guiding significance for the structural design of the multistage centrifugal fan.Based on the fan design theory established by this paper,successful designed three kinds of fan products,and test the performance of this fan according to the actual production demand.In particular,the series design were completed through the combination of different impeller stages,impeller diameter,impeller width,and rotation speed.And through experimental tests,verified the reliability of the calculation results of the performance prediction software and the correctness of the design theory.At present,some products have been applied to the company’s production line.