蜗壳局部切削对离心通风机性能的影响分析

Analysis of influence of local cutting of volute on the performance of double-suction centrifugal fan

蜗壳是风机的关键几何部件,对风机的内流场和外特性都具有重要的影响。以双吸式离心风机为研究对象,采用数值计算的方法对蜗壳切削前后的风机内流场进行了定常计算,讨论了蜗壳局部切削对双吸式离心风机内部流场特性的影响。通过对不同蜗壳位置的气流流动特性的分析,表明蜗壳切削不仅对局部切削位置附近的流场产生明显影响,而是会延伸影响到整个风机内流场。蜗壳切削后,蜗壳流道内的涡流尺寸和数量增多,但涡流强度降低,且涡流分布的规律性较差,流动稳定性减弱。因此,在需要对蜗壳局部切削时,应充分考虑蜗壳切削对整个流场稳定性的影响,避免风道性能明显恶化。

The volute is the key geometric component of the fan and has an important influence on the internal flow field and external characteristics of the fan.With the double-suction centrifugal fan as the research object,the steady numerical calculation method was used to calculate the internal flow field of the fan before and after the volute cutting.The influence of the local cutting of the volute on the internal flow field characteristics of the double-suction centrifugal fan was discussed.The analysis of the flow characteristics of different volute positions shows that the volute cutting not only has a significant impact on the flow field near the local cutting position,but also affects the flow field in the whole fan.After volute cutting,the size and quantity of vortex in volute channel increase,but the intensity of vortex decreases.The regularity of the vortex is relatively poor,and the flow stability is weakened.Therefore,when it is necessary to cut the volute locally,the influence of volute cutting on the stability of the whole flow field should be fully considered to avoid the performance deterioration of the fan.