大型汽轮发电机风扇静叶改型分析

采用轴向-径向通风的大型汽轮发电机多级轴流风扇静动叶片皆采用不锈钢材料,为进一步优化发电机结构,将静叶材料改为锻铝。受锻铝材料刚度和叶片生产工艺的影响,按原叶型生产的静叶容易发生变形,需对静叶叶型进行改型。采用NUMECA软件对叶片加厚和宽度减小两种静叶叶型的4级风扇气动性能进行了数值模拟,并与原风扇性能进行了比较。计算表明:叶片加厚方案气动性能更优,与原风扇相比,静压升只降低0.95%,对风扇在设计工作点的气动性能影响很小,改型方案可行。

Analysis on the Remodeled Static Blade Profile of the Large-size Turbine Generator Fan

Both static and dynamic blades of the multistage axial fan of the large-size turbine generator with axial-radial ventilation were made of the stainless steel.In order to optimize the construction of the generator, the raw material of the static blade would be replaced by the forged aluminum. Affected by rigidity of the aluminum and workmanship of the blade production, distortions took place frequently in the case that blade was manufactured following up with the original blade profile. Digital simulation of the aerodynamic performance of the 4-stage fan was done by means of the NUMECA software, through changing two variables, i.e. ＂increasing the blade thickness and shortening the blade length＂. Comparison between the aerodynamic performance of the original blade and that of the remodeled one was carried on. Results showed that the program of＂increasing the blade thickness＂ was better than the original one. The static press of the 4-stage fan was decreased only 0.95% against the original value, which resulted in less influence on the aerodynamic performance at the designed operating point of the fan. That meant the remodel program feasible.