某环保型烟花机离心风机出风偏离现象的分析与改进
Analysis and Improvement of Centrifugal Fan Deviation in Environment Protecting Fire-works Machine

针对环保型烟花机喷花量小、喷花高度不够以及喷花分散等问题，通过CFD数值模拟的方法对其送风系统的流动特性进行了分析与改进，发现离心风机因离心力导致的偏离风现象是导致喷花效果不佳的重要原因，因此提出了一种新结构来减小离心风机的出风偏离现象，最后通过喷花实验对新结构的有效性进行了验证。结果表明：离心风机的偏离风是导致喷花效果差的重要原因，所提出的新结构不仅降低了离心风机管道内以及出口位置风的偏离度，而且还可增大氧气与燃料的混合度与消除管道内部涡流现象，最终改善喷花效果；从数值上来看，新结构的出口最大风速的偏离度降低了约70%，最后还给出了风机转速不会改变出口速度分布梯度的形状但是会非线性的增大出口最大动压这一结论；这为以后类似的使用场景提供了参考。
Aiming at the problems such as small spray quantity, insufficient spray height and scattered spray of environment-friendly fireworks machine, the flow characteristics of its air supply system were analyzed and improved by CFD numerical simulation. It was found that the deviation of centrifugal fan caused by centrifugal force was an important reason for the poor spray effect. Therefore, a new structure is proposed to reduce the deviation of centrifugal fan. Finally, the effectiveness of the new structure is verified by spray experiment. The results show that the deviation of the centrifugal fan is an important reason for the poor spraying effect. The proposed new structure not only reduces the deviation of the wind in the centrifugal fan pipeline and at the outlet position, but also increases the mixing degree of oxygen and fuel and eliminates the vortex phenomenon in the pipeline, and finally improves the spraying effect. From the numerical point of view, the deviation degree of the maximum wind speed at the outlet of the new structure is reduced by about 70%. Finally, it is con-cluded that the fan speed does not change the of the outlet velocity distribution gradient, but in-creases the maximum dynamic pressure at the outlet nonlinearly. This provides a reference for similar usage scenarios in the future.