水轮机主轴中心孔补气

Air Admission to Main Shaft Central Hole in Hydraulic Turbine

水轮机在偏离最优工况运行时,水流的环量会使尾水管中心产生低压并形成涡带。此涡带引起尾水管压力脉动继而引起机组的振动和噪音。通过主轴中心孔补气,可减小尾水管内的真空度,破坏尾水管内的螺旋形涡带的形成和压力脉动、转轮的汽蚀等,从而保证机组的安全稳定运行。

In case of the turbine is operated departing the optimum condition, the low presure and the vortex band will be established in the draft tube centre by the flow circulation. The vortex will generate pressure pulsation, consequently the vibration and noise are arisen in the units. By means of air admission to main shaft central hole, the vacuum degree can be decreased, the generation of helical vortex band in the draft tube, pressure pulsation, cavitation.on the runner etc. can be destroyed, as a result the safe and stable operation of the units can be ensured.