水轮机运行加权因子的改进方法研究——以李家峡水电站为例

黄河上游的李家峡水电站运行15年以来,水轮机转轮上出现多条裂隙,严重影响机组运行效率,造成水资源利用效率低下,发电企业的经济效益大幅降低。鉴于此,本文开展了李家峡水电站水轮机加权因子的研究:(1)分别采用数理统计法、基于综合出力系数的改进数理统计法和旬电量平衡法,建立了李家峡水电站水轮机运行加权因子计算模型;(2)以2000—2014年水电站实测运行资料为准,设置了3种计算情景;(3)通过模型的对比分析,推荐基于效率系数的改进数理统计法计算的加权因子为最佳方案,确定了各水轮机运行效率的优劣次序;(4)计算了水轮机转轮改造后的预期加权因子、机组的特征水头和增发电量,优选了水轮机转轮改造预期的特性参数。研究成果对于水电站经济运行具有重要的指导意义和应用价值,为水轮机的转轮改造提供了技术支撑。

Improvement on methods of turbine operation weighted factors. Case study of Lijiaxia hydropower station

Lijiaxia hydropower station, located on the upper Yellow mainstream, has been in operation for over 15 years. However, a number of cracks appeared on the turbine runners, which has caused a serious effect on the operation efficiency, inefficient water use, and a dramatic reduction in the overall economic efficiency of this station. In this work, the weighted factors of turbine operation have been studied for the station to improve its runner operation and explore measures of runner retrofitting. We developed a statistics model for turbine operation, an improved version of this model using a comprehensive efficiency coefficient, and a ten-day electric energy balance model using turbine weighted factors. All the three models were used to examine three typical operation scenarios selected according to the long series of in-situ measurements at the station in the period of 2000-2014. The improved statistics model is recommended by comparison of the simulation results, and an order of operation efficiency priority for all the units of this hydropower station was obtained. For the schemes of turbine runner retrofitting, expected weighted factors, water level, and gains in electricity output were calculated. The results of this study are useful to economic operation of hydropower stations and turbine runner retrofitting.