动叶周向弯曲是改善轴流风机气动性能和噪声特性的有效方案。以某600 MW机组配套的两级轴流风机为对象，采用Fluent软件对其进行三维数值计算，分析了动叶弯曲对风机性能和气动噪声的影响，及其内流特征的变化。结果表明：动叶正弯可有效提高风机性能，在设计工况点，动叶上半叶高弯角α2=40°时全压最高提高232 Pa，α2=20°时效率最大提高0.16个百分点；动叶弯曲可有效改善叶顶处的流动状态，减小流动损失；动叶弯曲使叶轮区总声压级明显降低，相比原结构，α2=40°时第1级叶轮处总声压级降低5.87 dB，第2级动叶处总声压级降低2.46 dB，主要为单音噪声的降低；综合动叶弯曲对风机性能和噪声的影响，α2=20°为最优方案。

Circumferential bowing of blades is an effective measure to improve aerodynamic performance and noise of axial flow fans.Taking a twostage axial fan matched with a certain 600 MW power units as research object,the Fluent software was used to carry out the threedimensional numerical calculation,and analyze the effects of bowed blades on the fan performance and aerodynamic noise as well as the variation of internal dynamics characteristics.The results show that the positively bowed blades can effectively improve the fan performance.At the design condition point,with the angle of the upper half blade height α2 of 40°,the total pressure increases by up to 232 Pa.When α2 is equal to 20°,the efficiency increases by up to 0.16%.Bowed blades can effectively improve the flow regime at the blade tip and reduce the flow loss.The bowed blades significantly reduce the overall sound pressure level in the impeller area.Compared with the original structure,when α2 is equal to 40°,the overall sound pressure level decreases by 5.87 dB at the first stage impeller,and that decreases by 2.46 dB at the second stage impeller,which is mainly due to the reduction of the tonal noise.Considering the influence of bowed blades on the fan performance and noise integratedly,the optimal scheme with α2 of 20° is suggested in practical applications.

TH432

浙能集团科技项目（ZNKJ-2020-034）