湿蒸汽透平级水滴撞击动叶的频率及法向速度的研究

为了提高汽轮机湿蒸汽级叶片的可靠性，预防电厂中汽轮机叶片的水蚀疲劳断裂，建立了可求解动叶通道内湿蒸汽三维两相粘性可压缩湍流流场在旋转坐标系下的基本控制方程组，并将其应用于某汽轮机湿蒸汽透平级水滴运动的分析。给出了不同粒径水滴在动叶通道内的运动轨迹和单位撞击率。在此基础上详细分析了不同粒径水滴在动叶表面的法向速度分布。通过分析得出单位撞击率及撞击法向速度均高的“两高区域”为水蚀高发区。获得的相关定量数据为进一步研究液固撞击压力和动叶水蚀疲劳寿命提供了有力的依据。

Study on Frequency and Normal Velocity of Water Drop Impacting Blade in Wet Steam Passage of Turbine

In order to improve blade reliability under wet steam condition and prevent blade failure from liquid corrosion, the numerical model which can be used to analyze three dimensional, two-phase compressible turbulent flow field has been developed under rotating coordinate system, and it is adopted to investigate the water drop motion of a wet steam stage. Some usable results have been got: the motion traces of water drops with different diameter and unit impact rate, then the normal speed distribution of water drops impacting blade has been obtained. Based on the previous results, liquid corrosion is easy to appear in the region on the surface of blade with high unit impact rate and high normal impact speed. All of these numerical results provide important data to investigate water drop-solid impact pressure and liquid corrosion fatigue of blade.