水电站沉沙池泥沙最小危害粒径选择分析

Selection of minimum hazard particle size of sediment in hydropower station desilting basin

针对泥沙最小危害粒径选择十分复杂、目前尚未取得突破性进展、许多问题还有待深入研究的现状,首先对影响水轮机磨损的主要因素进行全面系统分析,说明目前国内泥沙最小危害粒径选择方法不够准确。在补充设计水头、水中泥沙含量、水流相对流速等水沙因子综合因素修正基础上,通过不同泥沙最小危害粒径的沉沙池投资和水轮机磨损维修费分析,进行泥沙最小危害粒径选择,并将此方法在麻子河一级水电站应用。结果表明:泥沙最小危害粒径越小沉沙池投资越大,水轮机磨损维修费越小,当泥沙最小危害粒径0.25 mm时,沉沙池投资与水轮机磨损维修费合计费用最少,因此沉沙池泥沙最小危害粒径选择0.25 mm合理的,充补水沙因子综合因素修正选择泥沙最小危害粒径方法是可行的。

It is very complex to choose the minimum hazard particle size of sediment.There has been no breakthrough progress,and many problems still need further studies.This paper first analyzed the main factors of turbine wear comprehensive system,showing that the current domestic sediment minimum hazard particle size selection method is not accurate.In addition to the supplementary design head,sediment content,water flow velocity,of water and sediment relative factor comprehensive factor correction based on minimum hazard particle size through various sediment desilting basin investment and turbine wear maintenance analysis,the minimum hazard particle size was selected,and this method was applied in the Mazi River Hydropower Station.The results show that the smaller the minimum hazardparticle size,the investment greater,and the turbine wear maintenance smaller.When the sediment particle size is 0.25 mm,the desilting basin investment and wear maintenance expenses was the least.Therefore,settling basin sediment minimum hazard particle size of 0.25 mm was reasonable,and comprehensive factors of filling sand replenishment factor correction selection the minimum diameter of sediment hazard method is feasible.