混流式水轮机转轮倒置安装轴向水推力的计算

Calculation of axial water thrust of the inverted-installation runner of mixed-flow turbine

目前大中型水电站混流式水轮机轴向水推力大 ,尾水管中涡带所产生的压力脉动常引起机组振动。如水轮机转轮倒置安装 ,将向下的轴向水推力改为向上 ,可以抵消机组转动部分的重量 ;如改变尾水管形状 ,可以消除涡带压力脉动 ,减小机组振动。以漫湾电站为例 ,经过计算说明正常安装与倒置安装轴向推力轴承负荷可大大减小。但倒置安装后其结构问题尚需进一步研究。

At present, the axial water thrust of the mixed flow turbine for large and medium scale hydropower stations is big so that the pressure pulse produced in the tailrace pipe often cause the vibration of generating unit. When the runner of turbine is inversely installed, the downward axial water thrust is changed into the upward one in order to offset the weight of the running part of generating unit. If the shape of tailrace pipe is changed, the pressure pulse can be removed so that the vibration of generating unit can be reduced. Taking the Manwan Hydropower Station as an example, the calculation showed that the load of axial thrust bearing in inverted installation way could be greatly reduced than that in normal installation way. But for the inverted installation, it is necessary to further study its structural problem.