Flow pattern and anti-silt measures of straight-edge forebay in large pump stations

Abstract

Forebay sedimentation is a common problem in large pump stations because the water is taken in from heavily silt-carrying rivers. Targeting the #3 Pump Station of West Trunk Line (Phase I), Gansu Jingtaichuan Irrigation District, the author learned about the current situation of forebay sedimentation through site investigation, and constructed a 3D structural model of prototype forebay based on ICEM-CFD. Furthermore, the flow pattern of the straight-edge front inflow (SEIF) forebay was simulated based on FLUENT. Then, two anti-silt measures, i.e. diversion pier and pressure plate, were put forward to improve the flow pattern of the forebay. The results show that the simulation results on forebay flow pattern agree well with the data acquired through site investigation; the trapezoid diversion pier reduced the range of the main reflux zone to some extent by distributing the forebay flow, failing to obviously improve the distribution of the flow field; the 45 pressure plate exhibited obvious optimization effect, reducing the range and intensity of reflux zone on both sides of the forebay.