基于CFD技术的太阳能污泥干燥室内热湿环境研究

基于传热传质理论,建立一种太阳能污泥干燥室内热湿耦合传递的数学模型。综合考虑空气流动以及对流和辐射传热,利用CFD软件Fluent的k~ε湍流模型、组分输运模型及辐射模型,初步分析了在太阳辐射条件下不同干燥室结构、排风形式以及通风量对太阳能污泥干燥室内干燥区域的温度、相对湿度以及速度分布的影响。模拟结果表明:干燥室内温、湿度模拟值与实测值吻合较好,平均相对误差分别为3.55%和5.39%。对比分析不同结构下干燥室内的流场分布,两出口排风形式的太阳能污泥干燥室可以形成良好的干燥微环境。当两出口排风风速≥5 m/s时,室内干燥区域温度高于室外环境温度,同时相对湿度低于室外环境相对湿度,且增大出流风速,在干燥区域内空气扰流强度增强,有利于干燥室内污泥水分的蒸发。

Study on thermal and moisture environment in solar sludge drying room based on CFD

Based on the theory of heat and mass transfer,a mathematical model of coupled heat and moisture transfer in solar drying room of sludge was established.This model is developed to preliminary analysis the temperature,relative humidity and velocity of distribution influenced by the different structure of drying room,ventilation forms and ventilation flux in solar drying room for sludge on the condition of solar radiation by comprehensive considering air flow,heat transfer in convection and radiation,using k~ε turbulence models,species transport models and radiation models in Fluent.The results of the developed mathematical model are good agreement with the experimental results and the relative error of temperature and humidity are 3.55% and 5.39% between simulation and experiment,respectively.Contrast analysis of the flow field in the different structure of solar drying room,the solar sludge drying room of two outlets of exhaust can form a good dry micro-environment.When the flow velocity is not less than 5 m/s of two outlets of the exhaust model,the temperature is not lower than the outdoor temperature and relative humidity is not higher than the outdoor RH in the indoor dry areas.Meanwhile,the air turbulence intensity of the dry region increases with the flow velocity,which can promote the evaporation of sludge.