Abstract：At present, oxidation ditches in wastewater treatment plants are associated with problems such as too low fluid velocity and sludge deposition. A three-dimensional oxidation ditch model with submerged propellers was built based on the existing drawing of the oxidation ditch in the Qinhuangdao Wastewater Treatment Plant and the fluid domains were meshed with unstructured-tetrahedral cells. Based on the Navier-Stokes equations and the standard k-ε turbulence model, the SIMPLE algorithm was used to simulate water flows in the oxidation ditch. The power of the propellers and velocity distribution in several cross-sections were calculated at different rotational speeds. Also, the dead water zone ratio and number of vortices were analysed. The results show that the optimal rotational speed of the propellers can be decided under the condition that the power of two propellers can provide the mechanical energy required by the oxidation ditch without exceeding the motor rated power. When the pool structure remains unchanged, altering submerged propeller installation position can improve fluid velocity distribution and reduce sludge deposition in the oxidation ditch effectively. For the vortex at the entrance, it can be improved by changing the inflow angle. The study outcomes in the paper have provided theoretical guidance for propeller rotational speed selection and installation position determination.
郑源*,李城易,张付林. 基于CFD的氧化沟中推流器转速与分布特性[J]. 排灌机械工程学报, 2019, 37(11): 953-960.
ZHEN Yuan*, LI Chengyi, ZHANG Fulin. Study on characteristics of rotational speed and installation position of submerged propellers in oxidation ditch by CFD. Journal of Drainage and Irrigation Machinery Engin, 2019, 37(11): 953-960.
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