基于流场计算的贯流式水轮机叶片修型  

Profile modification of tubular turbine blades based on flow field computation

作　　者：齐学义[1] 张庆[1] 邱文斌 马惠萍[1] 赵强[1] 

机构地区：[1]兰州理工大学流体动力与控制学院,甘肃兰州730050 [2]甘肃电力局刘家峡水电厂,甘肃永靖731600

出　　处：《兰州理工大学学报》2008年第5期45-49,共5页Journal of Lanzhou University of Technology

摘　　要：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.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 turbine. According to the result of numeric simulation and its analysis the technical remodelling only was made for the runner, that is the chords of blade＇s airfoils on the blade span from its middle to tip were extended with consideration of the requirement of blade＇s strength. By doing so, the spanwise variation of blade＇s profile （airfoil） was made as consistent with the pattern of third-order Bessel function for profile modification of the blades. Meantime, the satting angles of the blade sections were increased. It was shown by the simulation computation after modification of the runner that its efficiency was improved a lot compared with that of original hydraulic model, the maximal efficiency being improved by 2. 5% and the efficiency at nominal point- 2 %. It was verified by the practice of operation of the rernodelled＇rtmner that not only the vibration was eliminated and noise reduced during the operation of the unit but the maximal output of the gen- erator also reached 88% of its nominal capacity even in the case of operation with lower hydraulic parameters than the nominal ones （with the head less by 20%）. Consequently, this turbine could develop not only its nominal power but also possessed extra capacity of power generation if it operated with nominal hydraulic parameters.

关 键 词：贯流式水轮机 叶片修型 三维湍流计算 叶栅稠密度 

分 类 号：TK730.2[交通运输工程—轮机工程]