轴流风机叶片切割后的性能及静力结构特性

Performance and Static Analysis of an Axial Fan After Blade Trimming

以OB-84型动叶可调轴流风机为研究对象,采用Fluent软件模拟了在保持叶顶间隙不变情况下动叶安装角为29°、32°和35°,切割量为5%、10%和15%时的风机性能,分析了安装角和切割量对风机性能、噪声、叶片静力结构特性和经济性的影响.结果表明:当qV≥35m3/s时,全压和效率随切割量的增大及安装角的减小而降低,且大体积流量侧降低更为显著;当qV<35m3/s时,叶片切割和减小安装角均可使不稳定区减小甚至消失,进而改善风机运行状态,同时可降低噪声水平,且叶片静强度校核均满足要求,但叶片切割效果更好;选取β=29°、Δ=10%,可适用于机组在多种方案下运行,并保证机组经济性最佳.

Taking the OB-84 variable-pitch axial fan as an object of study, the fan performance was simula- ted using Fluent software in the case of constant tip clearance at installation angles of 29°, 32°and 35°, and with the blade respectively trimmed by 5%, 10% and 15%, so as to analyze the effects of installation angle and trimming rate on the fan performance, noise, blade static analysis and the economy, etc. Results show that both the full pressure and the efficiency reduce with increasing trimming rate and decreasing installa- tion angle when qv≥35 m3/s, with more remarkable decrease in the side of large volume flow; the unsta- ble region could be diminished or even eliminated either by raising the trimming rate or by reducing the in- stallation angle when qv〈35 m3/s, in which case the fan operation condition is to be improved, the noise level would be reduced, and all the results of static strength test could meet relevant requirements. For a- bove two methods, the effect of blade trimming is more evident. In the mode ofβ=29° and △= 10°, opti- mum fan economy could be ensured, which is applicable for different schemes.