采用旋转切向入流增加膜面附近的湍流强度和旋转流速,使膜面附近温度和浓度的边界层厚度降低,是一种新的提高膜蒸馏通量的方法.在此原理基础上运用CFD软件,采用水作为工质,对旋转切向入流空气隙膜蒸馏热容腔内的流场和温度场进行了模拟计算,验证了采用旋转切向入流将大大降低膜面附近的温度梯度,且切向入流管直管段与喷管段角度α和喷管形状(渐缩和无渐缩)的改变也将对边界层的厚度有很大的影响.
Adopting rotational tangential inpouring to increase turbulence intensity and velocity of flow nearby the membrane, made the thicknesses of temperature and concentration boundary decreasing, so it is a new enhancement permeate flux on air gap membrane distillation. The paper makes numerical simulation computation for temperature and flow field in a hot cavity circulation system of air gap membrane distillation using water as material by software of CFD, validated that temperature gradient nearby the membrane would decrease greatly with rotational tangential inpouring, and analyzed that different tangential inpouring angle α and spout shape will influence to temperature gradient.