多水源引水式水电站管道系统水力设计

Pipeline system's hydraulic design of multi-water-source diversion-type hydropower station

为提高水能资源的利用率,实现水资源的优化配置,跨流域多水源引水式水电开发在我国逐渐得到运用.但设计中发现有可能存在倒流与高水源被抽空的问题.针对该问题,运用恒定流理论,建立多水源引水式水电站管道系统的数学模型,在无量纲处理的基础上,推导引水主洞与引水副洞的流量计算公式及流量分配控制条件,并对影响流量分配的各种因素进行敏感性分析.其结论是:引水副洞水头损失系数是主导因素,增大该系数可消除倒流现象,进而使主、副洞流量分配达到合理范围,具体工程中可以通过减小副洞断面尺寸、增大副洞糙率及局部损失等措施来实现.

In order to improve the utilization ratio of hydropower resources,multi-water-source diversion-type hydropower station gradually get used in China.But this type of hydropower station may exist reflux and evacuation of high position reservoir.Aiming at the problem,a steady flow mathematical model of multi-water-souree diversion-type hydropower station＇s pipeline system is established.On the basis of dimensionless,the calculation formula of main and auxiliary diversion tunnels＇ flow and controlled condition of flow distribution are deduced;the various factors＇ sensitivity analysis that affect the flow distribution is conducted.It is concluded that： main diversion tunnel＇s head loss coefficient is the dominant factor,increase it can eliminate reflux and make the main and auxiliary diversion tunnels＇ flow to achieve a reasonable range.In the actual projects,this method can be achieved by reducing the size of the auxiliary diversion tunnel,increasing the auxiliary diversion tunnel＇s roughness and local head loss.