一种竖轴潮流发电水轮机性能优化方法的初步研究

从水轮机水动力学原理出发,建立了提高竖轴变攻角潮流发电水轮机能量利用率的优化方法和数学模型．该模型以叶片偏角随位置角的变化规律为优化参数,以水轮机工作速比范围内的能量利用率系数为优化目标,采用基于动量定理的多流管模型来求解流体动力．选取竖轴直叶摆线式水轮机为优化原型进行了优化计算,给出了优化后水轮机的能量利用率以及攻角随位置角的变化规律．通过与不同偏心率的摆线式水轮机的能量利用率及攻角随位置角变化规律的对比,分析了优化后水轮机水动力性能改变的规律及原因．结果表明,在优化速比范围内,水轮机叶片不同位置角处的水动力攻角都有所增大,作用于叶片上的力以及叶片受力对水轮机中心的力矩也相应增大,从而提高了水轮机的能量利用率。

An optimization method for improving hydrodynamic performance of the vertical-axis turbine for tidal streams energy conversion

An optimization method and mathematic model based on turbine hydrodynamics were presented to enhance the power coefficient of the vertical_axis straight_blade turbine for tidal streams energy conversion. The optimization parameter was selected as the changing rule of deflection angle versus azimuth angle and the optimization objective as the turbine power coefficient. The turbine hydrodynamic performance was solved by the multi_streamtube model based on the momentum theory. Calculating example was given with the prototype of the vertical_axis cycloidal turbine. Such optimal results as the turbine power coefficient and the relation between attack angle and blade motion were given with particular analysis to explain the improved performance. The results show that the turbine power coefficient is enhanced by increasing the blade hydrodynamic angle of attack together with increased force acted on the blade and moment acted on the turbine axis.