汽轮机静叶表面水膜缝隙抽吸的试验研究

Experimental Study on Removal of Water Film from Steam Turbine Stator Blade Surfaces by Suction Slots

在气液两相流试验装置上，对汽轮机空心静叶表面水膜缝隙抽吸进行了试验研究，并结合两相流动数值方法对水滴沉积的径向分布进行了探讨。试验条件为：叶栅进口空气湿度为7％，水滴直径分布在1．5～201μm之间，抽吸缝隙宽度为1mm，缝隙角度为45°。研究结果表明：吸力面上的抽吸缝在相对弧长约为0．5处具有最大的抽水效率，而压力面的抽吸缝隙越靠近尾缘处抽水效率越高，且压力面的缝隙抽水性能比吸力面的好，增加气流速度会引起抽水效率降低，增大缝隙抽吸压差可以提高抽水效率。另外，抽水效率沿着叶高方向是增加的。

An experiment on the performance of water film removal from hollow stator blade sur-faces of a steam turbine by slot suction was conducted on an air-water two-phase flow rig with an inlet air wetness of 7%, a droplet diameter range of 1.5-201μm, a slot width of 1 mm and a slot angle of 45° to the blade surface. The investigation into the radial characteristic of the droplet deposition on the blade surface was also performed with the two-phase flow numerical simulation method based on the experiment data. The results show that a maximum water removal rate was obtained at a relative arc length of about 0. 5 for the suction slot on the suction side, and for the suction slot on the pressure side the higher water removal efficiency was observed when the slot was nearer to the blade trailing edge. The water removal efficiency of the blade surfaces was greater for the suction slot on the pressure side than that on the suction side. Increasing airflow velocity resulted in the decrease of water removal efficiency, and larger suction pressure difference leaded to higher water removal efficiency. In addition, the water removal efficiency exhibited an increase in the radial direction of the blade.