天然气催化反应壁面传热传质的数值研究

NUMERICAL STUDY ON HEAT AND MASS TRANSFER ON THE SURFACE WITH CATALYTIC REACTION

应用二维数学模型研究天然气催化燃烧壁面反应及载体气固界面上热质传递与流动耦合的现象。通过改变载体通道入口混合气体(天然气与空气)的温度、质量分数及壁面上反应的条件来评价努塞尔数和舍伍德数。模拟结果表明,努塞尔数和舍伍德数并不单独取决于燃料质量分数及壁面条件,而取决于壁面的反应速率。模拟同时表明,进口的温度对通道壁面传质影响最大,其它影响较小。

A two-dimension mathematic model has been developed in order to study the effect of heat and mass transfer coupled with flow on the surface of with catalytic reaction. Nu and Sh numbers are appraised by the changes of the temperature of the mixtures (natural gas and air), the mass fraction of natural gas and the conditions outside wall. The numerical results show Nu and Sh numbers independently do not depend on mass fraction and surface conditions, but on the reaction rate on the internal surface. Meanwhile, the results also reveal the inlet temperature intensely influences mass transfer in the channel and the others do not influence mass transfer.