Abstract：Superficial water velocity in a hypolimnetic oxygenator directly influences the oxygenation effectiveness of a hypolimnetic aerator. Aiming at the common problem of poor prediction of superficial water velocity, driving energy and energy losses of the gas-liquid two-phase flow in the aeration chamber were systematically analyzed, dimensionless formulas for calculating the energy losses due to wakes and top were particularly proposed, a one-dimensional hydrodynamic model for the water flow in the aeration chamber was developed, and a analytical solution to this hydrodynamic model was built using the real-domain method of MATLAB. The predicted superficial water velocities were validated against the operation data of hypolimnetic oxygenators installed in Lakes Prince, the United States, the prediction errors fell into the range of ±8%, which were much lower than the exiting prediction errors of ±20%. Under the orifice diameter of 2.6mm, the superficial water velocity increases with the air flowrate when the air flowrate increased from 0.018m3/h to 0.063m3/h; Under fixed air flowrate condition, the superficial water velocity increased when the orifice diameter decreased from 2.6mm to 0.26mm, but it remained unchanged when the orifice diameter further decreased to 0.026mm. Driving energy and energy losses under various conditions were calculated, the inherent factors causing the variations of superficial water velocity were revealed. This developed hydrodynamic model can be used to guide the design and optimization of a hypolimnetic oxygenator.
孙昕, 段飞飞, 刘凌炜, 解岳. 曝气条件对等温层曝气器水力性能的影响[J]. 中国环境科学, 2015, 35(9): 2698-2705.
SUN Xin, DUAN Fei-Fei, LIU Ling-Wei, JIE Yue. Effects of aeration conditions on the hydrodynamic performance of a hypolimnetic aerator. CHINA ENVIRONMENTAL SCIENCECE, 2015, 35(9): 2698-2705.
