多孔介质对室内有机挥发物扩散的影响

Influence of porous media on diffusion of VOCs in room

为了研究存在于多孔壁面的封闭腔体中温度、挥发性有机化合物(VOCs)质量浓度的分布特征,本文根据不可逆过程热力学基本原理,建立复合腔体内热质传递的数学模型。采用有限元数值计算方法对控制模型进行求解,得到不同达西数下复合腔体内流场、温度场和VOCs质量浓度场的分布特性。研究表明因多孔介质的存在,系统内的传热传质速度明显降低,而当多孔壁面的渗透率很低(相当于不可渗透壁面)时,传热传质速率降至最低。

In o izable Organic rder to study the distribution character of temperature and concentration fields of Volatil- Components （VOCs） in an enclosure with a porous wall, the numerical model for heat and mass transfer in a composite cavity is founded based on irreversible thermodynamics. Distribution character of flow, temperature and VOCs concentration fields for different Darcy numbers is obtained by using finite element method to solve the model. Numerical results show that velocities of heat and mass transfer are dramatic declined due to the influence of porous medium. The velocity would be re- duced to a minimum value when the porous wall was taken as an impermeable wall because of its small permeability.