基于空间曲面的水泵水轮机机组数学模型及仿真

Mathematical model and simulation of pump turbine with characteristic space curves

过渡过程中水轮机外特性数值解法高度依赖于特性曲线的准确性,水泵水轮机全特性曲线不同开度线间具有交叉、聚集、扭卷现象,从平面的角度无法准确刻画和拟合其非线性的变化趋势,为满足抽水蓄能电站大波动等过渡过程工况数学仿真的需求,采用非均匀B样条函数重构全特性空间曲面,并基于全特性空间曲面建立了水泵水轮机可逆式机组空间曲线机组数学模型、空间曲面机组数学模型,对多值问题提出分区域求解和相邻最近解的思想,并对数值计算与原型试验的结果进行了对比分析,结果表明,数值计算与原型试验结果吻合较好。

Solution of the external performances of pump turbine in numerical simulation of transient process highly depends on the accuracy of characteristic curve. The complete characteristic curves of a pump turbine are often interlaced, assembled and tortuous between different openings, and description of such nonlinear variations in a plane coordinate is extremely difficult. In this study, complete characteristic curved surfaces were constructed using non-uniform B-splines for simulation of transient process of large fluctuations, and mathematical models of a reversible pump turbine were developed using space curves and these space surfaces. And methods of sub-regions and nearest rule were used to avoid multi-solutions. Comparison of the calculations with prototype measurements shows a good agreement.