【摘要】 在详细分析多孔并联分段低压输水系统水力特性的基础上,建立了这一输水系统的非恒定流控制方程以及关闸和不关闸条件下的保水堰边界条件。应用所建立的数学模型对南水北调天津干线工程进行了数值模拟计算,得到了运行工况和检修工况下该输水系统的水力特性以及并联空间连通性对水力特性的影响,并提出相应的控制措施。本文还针对输水系统的水力特性,对单联分段低压输水单元的水力振荡方程进行了修正,推导出多孔并联分段输水单元的水流振荡方程和连通式保水堰自由水面的固有振荡频率公式,提出了消除水力共振、缓解输水单元水力振荡的控制条件,为工程设计和运行管理提供技术依据。更多还原

【Abstract】 The stepped low-pressurized water diversion system with parallel multi-holes in regulation tanks can reduce the pressure of the conduit and effectively simplify the control of the flow discharge.The mathematical model of the unsteady flow occurred to this kinds of project is established.The role of the detaining weirs in the tanks is analyzed and the approach of dealing with detaining weirs,in cases with or without controlling gates,as the boundary condition of transient flow calculation for the water diversion system is investigated.The hydraulic characteristics of the diversion system in Tianjin section of South-toNorth Water Transfer Project adopted this type of system are calculated and the influence among the holes are analyzed.The equation of the sectional hydraulic oscillation occurred to the system is deduced and the measures for minimizing this phenomenon is suggested.The optimal operation mode of the project is proposed.更多还原