水电能源科学

为合理应用立式分层闸站工程，分析了合建枢纽工程排涝工况出水流场特性。以河北省龙堂闸站工程为背景建立三维模型，分析工程结构和运行机理，并与典型水力模型进行对比，确定了排涝工况下两种最不利工况(半有压流-自由出流、有压流-淹没出流)。应用Fluent软件进行数值模拟，得到特征断面的液相分布和速度矢量分布情况。结果表明，涵洞内流态特性与涵闸流态相似，自由出流工况下形成三处明显的涡旋结构，涡心为低速区；淹没出流工况下存在折冲水流，无明显低速区；竖井段挡板附近流速普遍较低(<0.2 m/s);水泵运行对涵洞主流流态影响微弱；出流均未直接冲击潜水泵及挡板。研究表明，立式分层闸站工程适用于支流河底高于干流，且泥沙含量较小的灌溉区交叉河段。

To support the rational operation of the vertically stratified combined sluice-pump project, the characteristics of the outflow field under drainage operation conditions were analyzed. A three-dimensional model was established based on the Longtang Combined Sluice-Pump Project in Hebei Province. Through analysis of the engineering structure and operational mechanism, two critical operating conditions(semi-pressurized flow with free outflow and pressurized flow with submerged outflow) for drainage were identified by comparison with typical hydraulic model. Numerical simulations were performed using Fluent software to obtain liquid-phase distributions and velocity vector fields at characteristic cross-sections. The results demonstrate that flow patterns within the culvert resemble those in sluice-culvert structures. Under free outflow conditions, three distinct vortex structures form with low-velocity zones at vortex cores. Submerged outflow exhibits deflected flow without distinct low-velocity zones. Flow velocities near baffles in the vertical shaft section remain low(<0.2 m/s). Pump operation negligibly influences mainstream culvert flow patterns. Outflow does not directly impact submersible pumps or baffles. The study confirms that vertically stratified sluice-pump structures are suitable for intersection segments in irrigation districts where tributary riverbeds are higher than the main channel and sediment loads are low.