沙坪水电站机组增容改造可行性水力计算研究

Research on the Feasibility of Capacity Upgrading of Shaping Hydropower Station by Hydraulic Calculation

沙坪水电站由于多年运行存在机组振动大和过流部件磨损严重问题,需对现有机组进行技术改造并计划增加容量,提高电站安全性和年发电量。根据引水系统布置,基于机组出力计算数学模型,结合电站稳定工况下实测资料,准确计算引水系统的实际糙率值。结果表明,稳定工况下数模计算获得的调压室水位和水轮机水头与实测值平均偏差小于0.9%,证明数模的准确性和计算采用糙率的合理性;沙坪水电站在保持原水工建筑物和基坑尺寸不变的条件下,转轮直径由原来的2.03 m增大至2.10 m,电站总容量增加5%是可行的。增容改造后机组丢负荷或增负荷的调压室最高和最低涌浪水位仍然能满足水电站调压室设计规范要求,也符合调压室现有高程布置要求,因此沙坪电站增容改造是可行的。

Due to the problems of large unit vibration and serious wear of overcurrent components in Shaping Hydropower Station for many years of operation,it is necessary to increase the capacity of the units to improve the safety and annual power generation of the power station.In this paper,according to the layout of the water diversion system,based on the mathematical model of unit output and combined with the measured data of the power station,the actual roughness of the water diversion system under stable conditions is calculated.The results show that the average deviation between the measured values and the calculated values of the surge chamber water level and the turbine head is less than 0.9%,which proves the accuracy of the numerical model and the feasibility of the roughness adopted.In the case of keeping the size of the original hydraulic structure and foundation pit unchanged,the runner diameter increases from 2.03 m to 2.10 m,which is feasible to increase the total capacity of the station by 5%.The maximum and minimum surge water levels of surge chambers with load loss or load increase can still meet the design specifications of surge chambers and the existing elevation layout requirements.Therefore the capacity-increasing transformation of Shaping Hydropower Station is feasible.