灌溉取水对向家坝水电站发电影响分析

Influence Analysis of Irrigation Water Intaking on Power Generation of Xiangjiaba Hydropower Station

向家坝水电站工程具备发电、通航、防洪、灌溉、反调节、拦沙六大功能,工程自2012年运行以来,除灌溉以外,其余效益均已逐渐显现。随着向家坝南北总干渠首部取水隧洞工程完工,北总灌区一期工程全面施工,灌溉取水对于向家坝水电站发电的影响研究,是一项亟待完成的工作。通过1970~2013年43年长系列径流系列调节演算,计算了在上游6座大型水库调蓄及滇中引水影响下向家坝水电站入库流量变化情况,并以此为基础计算了北灌区一期、北灌区二期、灌区全部建成取水后,对向家坝水电站发电的影响。研究表明,灌溉取水导致向家坝发电量减少,各期取水后发电量较取水前分别减少1.78×10^(8)、2.84×10^(8)、3.78×10^(8) kW·h,且主要集中在枯水期。各期取水后,下泄流量最大减少109 m^(3)/s,年平均保证出力最大减少105 MW,装机利用小时数最大减少63 h。

Xiangjiaba Hydropower Station has six functions:power generation,navigation,flood control,irrigation,reverse regulation,sediment retaining.Since the project was put into operation in 2012,all other benefits except irrigation have begun to show gradually.With the completion of the first water intaking tunnel project of the north and south main canal of Xiangjiaba,and the comprehensive construction of the first phase project of the north general irrigation area,the research on the impact of irrigation water intaking on the power generation of Xiangjiaba hydropower station is an urgent work.Based on the adjustment calculation of 43 years series runoff during 1970-2013,inflow variation of Xiangjiaba hydropower station was calculated by considering the impact of the six large reservoirs regulation and storage in the upstream and water diversion in the Yunnan province.On this basis,the impact of water intaking after the first phase of north irrigation area,north second phase of irrigation area,and irrigation district being completed on the power generation of the Xiangjiaba Hydropower Station was analyzed.The research shows that irrigation water intaking reduces the power generation of Xiangjiaba,which is 1.78×10~8 kW·h,2.84×10~8 kW·h and 3.78×10~8 kW·h,respectively,compared with that before water intaking,and mainly in the dry season.After the intake of water in each period,the water discharge can be reduced by 109 m^(3)/s at most,the annual average output can be reduced by 105 MW at most,and the number of installed hours can be reduced by 63 h at most.