摘要
基于ANSYS CFX软件,分别采用单级和多级模型,研究了某1 000 MW火电汽轮机叶片表面粗糙度对自发凝结级级性能和叶栅通道内蒸汽自发凝结过程的影响。在所有计算中,忽略水滴沉积在叶片表面形成水膜的影响。计算结果表明：设计工况下,叶片表面的粗糙度将使级效率降低,且粗糙度越大,级效率下降数值也越大;静叶表面粗糙度对级效率的影响大于动叶表面粗糙度对级效率的影响;无论是静叶还是动叶,吸力面上粗糙度使级效率下降的数值都大约是压力面上粗糙度使级效率下降数值的4～5倍;粗糙度只影响其所在叶栅内的气动损失,而对上游和下游叶栅内气动损失影响很小;此外,叶片表面的粗糙度还将降低蒸汽在叶栅内的自发成核凝结程度,从而降低因自发凝结形成的水分。
In this work, single-stage and multi-stage models are employed to investigate the effect of blade roughness on the performance and spontaneous nucleating processes in steam turbine nucleating stage based on commercial software ANSYS CFX. In all the calculations, the effect of films and rivulets due to the deposition of droplets on the blade surfaces is ignored. The calculated results show that blade surface roughness degrades stage efficiency and the efficiency degradation due to blade roughness increases with the value of roughness under the design condition. Moreover, roughness on stator vanes degrades the stage efficiency more than roughness on rotor vanes. For stator vanes and rotor vanes, the stage efficiency degradation due to roughness on suction side is about 4～5 times as large as that due to roughed pressure side. Results of the current work also indicate that the blade roughness has almost no effect on the aerodynamic losses of the upstream and downstream blades and only affects the aerodynamic loss of the localized blade. In addition, the blade roughness weakens spontaneous nucleation in blade passage, leading to the reduction of liquid mass fraction due to nucleation.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2015年第21期5533-5541,共9页
Proceedings of the CSEE
基金
国家自然科学基金资助项目(51376140)~~
关键词
汽轮机
叶片
自发凝结级
粗糙度
级效率
气动损失
steam turbine
blade
spontaneous nucleating stage
roughness
stage efficiency
aerodynamic loss
