厌氧膨胀颗粒污泥床反应器水力优化数值模拟研究

厌氧膨胀颗粒污泥床（EGSB）反应器内部流场及浓度场分布影响反应器运行效率，污染物不均匀分布会导致反应器内微生物无法与污染物充分接触，使处理效率下降。对EGSB反应器内部流场及浓度场进行模拟，研究污染物浓度分布对处理效率的影响，可实现对反应器结构的优化。在流体力学模型的组分浓度输运方程源项中嵌入厌氧消化数学模型，构造CFD-厌氧消化耦合模型进行模拟。结果表明，EGSB反应器内部污染物浓度分布呈现中轴处高近壁处低的不均匀分布，在一定高度处甚至出现死区，不利于微生物的生长，严重降低了反应器处理效率。通过在反应器内增设挡流板，使中轴处污染物随水流向壁面分流，可以有效提高近壁面附近污染物浓度，减小死区体积，提高反应器处理效率。

Numerical simulation of hydraulic optimization in EGSB reactor

The distribution of flow field and concentration field inside the EGSB reactor will affect the operating efficiency of the reactor, and the uneven distribution of pollutants will lead to the failure of microorganisms in the reactor to fully contact with pollutants,thus reducing the treatment efficiency.A CFD-anaerobic digestion coupled model was constructed by embedding the mathematical model of anaerobic digestion into the component concentration transport source term of the hydrodynamic model. The flow field and concentration field in the EGSB reactor were simulated to study the effect of pollutant mass transfer on the treatment efficiency, and then the reactor structure was optimized.The concentration distribution of pollutants in the EGSB reactor is uneven, which is higher at the central axis and lower near the wall, and even dead zone appears at a certain height, which seriously reduces the treatment efficiency of the reactor.By adding a baffle plate in the reactor, the concentration of pollutants near the wall can be effectively increased, the volume of dead zone can be reduced and the treatment efficiency of the reactor can be improved.