进口条件改变对风机性能影响的研究

Influence of the change of inlet conditions on the performance of fan

以某低压轴流风机为研究对象,采用数值模拟与实验对比的方法,通过改变风机进口集流器圆弧大小以及电机和叶轮的安装位置形成电机前置,研究轴流风机进口结构形式及流场改变对其气动性能的影响。研究结果显示:0.2D以内的四种不同半径的圆弧形集流器对进口流场及出口静压升并无明显改善;电机前置加长了风机进口长度,对进口流场起到明显的整流作用,在设计工况点下,进口流场得到明显的改善,动叶表面压力分布更加均匀,动叶及导叶出口叶根处气流失速区基本消失,流场更加稳定,出口静压提高12.5%,静压效率增加7.2%。

Taking a low-pressure axial-flow fan as the research object,the influence of the inlet structure and flow field on its aerodynamic performance was studied by changing the arc size of the inlet collector and the installation position of the motor and impeller.The results showed that the inlet flow field and outlet static pressure rise were not significantly improved by four kinds of circular arc collectors with different radius less than 0.2 D.The length of fan inlet lengthened by motor front-end has obvious rectification effect on inlet flow field.At the design operating point,the flow field at the inlet was improved obviously,the pressure distribution on the surface of the rotor blade was more uniform,the stall zone at the root of the rotor blade and guide vane exit vane basically disappeared,the flow field was more stable,the static pressure at the outlet was increased by 12.5%,and the static pressure efficiency increased by 7.2%.