A numerical study on moisture adsorption/desorption in silica-gel packed beds

• Main Authors: Ling-YiHuang, 黃齡儀
• Other Authors: Tian-Shiang Yang
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/85465578706606704434

碩士 === 國立成功大學 === 機械工程學系 === 104 === Silica-gel desiccant is widely used in various industrial dehumidifying processes. To help improve such system design, it requires understanding of the heat and mass transfer mechanism during moisture adsorption/desorption process of silica gel. Among current research models, SSR (solid-side resistance) model, with additional consideration of intraparticle mass transfer resistance, usually can predict more accurately than the earlier PGC (psuedo-gas-side controlled) model does. However, in previous studies, the effect of adjusting the key system parameters, and that of intraparticle thermal resistance, on silica-gel adsorption process have not been discussed. In the present study, it is found that increasing the inlet air velocity and temperature and the desiccant particle radius make the total mass of water adsorbed by silica gel increase faster. Besides, increasing the inlet air velocity and decreasing the particle radius make the effect of neglecting intraparticle thermal resistance in SSR model more remarkable. On the other hand, to make SSR model fit the previous silica-gel adsorption experimental results in our research team more properly, we also use SSR model to simulate and compare with the results of the experiment. It is recommended that adding Darcy’s law in SSR model, extending SSR model from 1-D (with axial direction) to 2-D (with both axial and radial directions), and taking the heat convection on the wall of the reactor into account.