合流溢流污水高效沉淀池计算机模拟研究

该文利用计算流体动力学模型,对合流溢流污水高效沉淀池进行了模拟。模拟结果表明,由于表面负荷较大,进水水流以较快速度从进水挡板下部通过,冲击池底部污泥层,同时穿过池底部撞向池下游池壁,再在斜板下方产生回流,从而影响沉淀池的沉淀效果。因此在设计高表面负荷沉淀池时进水的布水均匀尤其重要。在给定出水SS设计标准下(60 mg/L),进水SS为500 mg/L,经CFD模型优化后的沉淀池,能将表面负荷维持在20 m3/m2.h左右范围正常运行。

Study on Computer Simulation of High-rate Sedimentation Tank for Combined Sewer Overflow Sewage

The computational fluid dynamics model is used to simulate the high-effective sedimentation tank for combined sewer overflow sewage.The simulating result shows that the influent more quickly flows through the lower of the influent baffle,attacks the sludge layer at the bottom of tank,simultaneously passes through the tank bottom and crashes into the tank wall at the downstream of tank,and again returns at the lower of inclined plate in result to influence the settling effect of sedimentation tank due to higher surface loading.Therefore,the influent distribution uniformity is particularly important for the design of sedimentation tank with high surface load.With the influent SS concentration of 500 mg / L and the effluent SS concentration of 60 mg / L(refer to design criteria),the sedimentation tank optimized by the CFD model can be normally operated with the surface loading maintained at about 20 m 3 /m 2.h.