基于流场计算的贯流式水轮机叶片修型

针对某电站轴伸贯流定桨式水轮发电机组运行过程中出力远达不到额定值并伴随有振动和噪声的问题,采用CFD数值模拟方法,对水轮机过流通道进行流场的数值模拟计算.发现该电站原来所选用的水力模型及水轮机制造中均存在着一定缺陷或不足.依据数值模拟与分析的结果对转轮实施技术改造,即对其叶片由翼展中部至轮缘处的翼型分别进行延长,考虑强度的需要,使翼型沿翼展方向的变化遵循三阶贝塞尔曲线的规律进行修型;且增大叶片安放角.修型后的转轮经模拟计算结果表明,其效率较原水力模型有较大提高,其中最高效率提高2.5%,额定点的效率提高2%;改造后的转轮经试运行实践证明,消除了机组运行中的振动,减小了噪声;在水能参数达不到额定值(水头低20%)的情况下,发电机的最大输出功率已达到额定容量的88%;据此估算,在额定水能参数下,该水轮机出力不仅完全能达到额定出力的要求,而且还具有一定的超发能力.

Profile modification of tubular turbine blades based on flow field computation

Aimed at the problems occured during the operation process of fixed-blade shaft extension tubular turbine generator set in a power plant such as the large deficiency in power output from its nominal one and the accompanying vibration and noise,the flow field in the flow passage of turbines was numerically evaluated with CFD numeric simulation.It was found that there was some defect and deficiency in the original hydraulic model selected for the power plant and as well in the manufacturing process of the tur...