混流可逆式水轮机转轮轴向水推力计算分析

分析了混流可逆式水轮机转轮轴向水推力的构成，给出了相关的数学计算模型．结合某抽水蓄能电站实际工程，分别利用解析计算和数值计算两种方法进行了水轮机转轮轴向水推力的比较计算，指出转轮轴向水推力的计算精度主要取决于高压腔内转轮表面所受轴向水推力F11、F21的计算精度，而影响F11、F21值大小的主要因素是止漏环漏水量和高压腔内水流的旋转角速度；当上、下止漏环外径差值较小并假定上、下止漏环漏水量相等的情况下，解析计算方法求出的转轮轴向水推力结果误差不大．

Calculation and analysis of axial thrust acting on turning wheelof flow-mixing reversible hydraulic turbines

The composition of axial thrusts was analyzed, and a corresponding numerical model was given. In combination with a practical project of a pumped-storage hydropower plant, the calculated results of the axial thrust by the methods of analytical calculation and numerical calculation were compared. It was pointed out that the precision of calculation of the axial thrust on turning wheels was mainly determined by that of the axial thrusts F_(11) and F_(12) acting on the surface of the turning wheels in high-pressure cavities, and that the leakage from sealing rings and angular velocity of water flow in high-pressure cavities were the main factors affecting the values of F_(11) and F_(12). It was also indicated that, with the equal leakage from the upper and lower sealing rings, the error of the calculated result of the axial thrust by the analytical method was small if the difference between the outside diameters of the upper and lower sealing rings was small.