在水汽逆向流动填料塔内热质同时传递过程的研究

Simultaneous Heat and Mass Transfer in a CountercurrentLiquid Water-vapor Packed Column

在内径94mm,高2.1m的填料塔内进行了热、质同时传递过程的热模实验研究。结果表明,存在一个合适的(液/汽)质量比为7.7～13.3。当系统内液汽比在该范围附近时,床层内气相温度分布比较稳定。同时,对填料塔内热质同时传递过程建立了数学模型,模型计算值与实验值吻合良好。计算出在本实验系统的操作条件下,全塔平均传质和传热系数分别为:kg=0.060kg/(m2·s·MPa)和αg=2.01W/(m2·K)。本文所建立的数学模型能应用到工业实践中。

The simultaneous heat and mass transfer process is investigated in a countercurrent liquid water-vapor system, in a randomly packed column, with inner diameter of 94 mm and height of 2.1 m. It is observed that the axial temperature along the column changes significantly with the mass ratio of liquid water to vapor. When the mass ratio of liquid water to vapor is in the range of 7.7~13.3, the temperature profiles of the entire column show the similar characteristics and consequently, the stable operation can be achieved. A detailed mathematical model, assuming the transfer diffusion in the vapor side, is proposed to predicate the temperature profile along the packed column. The simulated results are in well agreement with the experimentaldata. And the heat and mass coefficients under different operating conditions are calculated, which are useful for the design of the industrial scale packed column. The mean mass transfer coefficient and heat transfer coefficient in this packed column is as following, k_g=0.060 kg/(m^2·s·MPa) and α_g=2.01 W/(m^2·K).