深层隧道进流式泵站前池流态及整流措施研究

Study on flow pattern and rectification measures in forebay of deep tunnel inflow pumping station

为改善深层隧道进流式泵站前池内的旋流、偏流等不良流态,基于RNG k-ε湍流模型对前池流态进行数值模拟,研究适用于此类城市排涝泵站的整流措施。数值计算结果表明:泵站前池、进水池内存在局部立面旋滚、螺旋流、斜向流、流速分布上高下低等不良水力现象,致使泵站进水流道水力条件不佳;采用双层环形板和两组导流墩的组合式整流措施可抑制前池、进水池中的立面旋滚、螺旋流和斜向流流态,从而有效改善流道的进水条件,提高进水流道进口处流速分布均匀度,使泵进水状况变好,提高泵站运行的可靠性。

In order to improve undesirable flow phenomena like spinning and partial flow in forebays of deep tunnel inflow pumping stations,the flow in forebays was numerically simulated based on the RNG k-εturbulence model,and rectification measures applicable to this kind of urban drainage pumping station were investigated.Numerical simulation results revealed the presence of several adverse hydraulic phenomena within the forebay and inlet pool of the pump station,including local vertical spinning,spiral flow,oblique flow,and uneven velocity distribution with higher velocity at the top and lower velocity at the bottom,resulting in poor hydraulic conditions in the inlet channel of the pump station.A rectification measure combining a double-layer ring plate and two groups of guide piers can suppress the vertical spinning,spiral flow and oblique flow in the forebay and inlet pool.This rectification measure significantly improves the inlet conditions of the flow channel,leading to more uniform flow velocity distribution at the inlet of the inflow channel.Consequently,the pump inflow water conditions become better,and the operation reliability of the pumping station is improved.