叶片厚度分布对超窄流道离心叶轮性能的影响

Effect of Blade Thickness on Performance of Small Flow RateCentrifugal Compressor Impellers

研究了石化生产中使用的某出口相对宽度仅为0 0092的13级离心压缩机的末级叶轮.分别用等厚度、零厚度以及C4翼型的叶片构造叶轮,并进行计算流体动力学分析.计算分析发现:C4叶轮内部流动状况在小流量范围内最好;零厚度叶轮在大流量区效率最高;在设计工况下,C4叶轮的效率较原始等厚叶轮高1%.结合上述叶片的特点并考虑到加工的方便性和强度要求,以叶片厚度分布为设计变量,用响应面方法进行了优化设计.优化后叶轮的总体性能高于原始叶轮,在大流量区,优化叶轮的性能高于C4翼型叶轮.

The last stage of a thirteen-stage centrifugal compressor used for petrochemical production, in which the exit relative width of the impeller was only 0.0092, was studied. The blades of the centrifugal impellers were generated with constant thickness, zero thickness and C4 profile respectively and the performance of the structured impellers was computed with a computational fluid dynamics (CFD) code. The analysis results indicate that the performance of the C4 impeller is best in small flow rate range, and in large flow rate range the efficiency of zero thickness impeller is the highest one. In the design point the efficiency of C4 impeller is 1% higher than that of constant thickness impeller. Considering both the machining capability and strength requirement, the blade thickness distribution is proposed as the design variable to be optimized with the response surface method. The overall performance of the optimized impeller is higher than that of the original impeller, and in the large flow rate range it is also higher than that of C4 impeller.