建筑室内温度分布特性对交叉扩散水平的影响

Influence of Temperature Distribution on Cross Diffusion Level in Building Room

基于不可逆热力学,分析了建筑室内热量、水蒸气组分和污染气体组分之间交叉扩散耦合特征,并给出了三者之间的交叉扩散传递关系以及温度分布对交叉扩散水平的影响关系,同时针对室内不同湿度和污染气体浓度水平,对温度分布影响下的交叉扩散特征与水平进行了具体讨论.结果表明,当温度梯度和热附加扩散系数正负相同时,交叉扩散作用所形成的水蒸气组分梯度和污染气体组分梯度小于零,反之则大于零;同时,在相同温度梯度和热附加扩散作用下,室内初始湿度和初始污染气体浓度水平越高,所形成的2种组分梯度的绝对值越大,并且初始湿度和初始污染气体浓度水平的影响都具有显著性.

The coupling characters of cross diffusion among heat,water vapor and contaminant gas in building room were analyzed according to the non-equilibrium thermodynamic theory. Cross diffusion relationship of heat, water vapor and contaminant gas mass transfer and influence of temperature distribution on cross diffusion level were obtained. The cross diffusion characters and level under different temperature distributions were discussed,for diverse relative humidity and contaminant gas concentration in building room. The results show that water vapor and contaminant gas mass grads are less than zero when temperature grads and thermal diffusion coefficient are both positive/negative, otherwise the two mass grads are more than zero. And the higher the initial humidity and contaminant gas concentration are, the greater the absolute values of water vapor and contaminant gas mass gradsare for the same temperature grads and thermal diffusion coefficient, and influences of initial humidity and initial contaminant gas concentration levels on the two mass grads are remarkable.