每年出版 6 期
ISSN 打印: 1940-2503
ISSN 在线: 1940-2554
Indexed in
COUPLED HEAT AND MASS TRANSFER DURING ABSORPTION OF WATER VAPOR INTO LIBR-H2O SOLUTION FAN SHEETS
摘要
This work characterizes, both numerically and analytically, the heat and mass transfer in a fan-shaped liquid sheet of LiBr−H2O solution that absorbs the surrounding water vapor inside an adiabatic absorber for absorption chillers. A model for the simultaneous heat and mass transfer into the fan-shaped liquid sheet is presented together with the assumptions and simplifications that yield to an affordable problem. The increasing mass flow rate in the sheet due to the absorption of vapor is included in the model, thus resulting in a nonlinear system of equations. The coupled temperature and water mass fraction flow fields in the sheet are numerically solved. Additionally, an approximate analytical solution of the problem is obtained in the form of a series solution. Profiles of normalized temperature and mass fraction in main flow and transverse directions are presented. The radial distribution of local and mean Sherwood number is also evaluated. The results show the existence of temperature and mass fraction regions in the fan sheet which are analogous to the regions present in nonexpanding sheets. Good agreement between the fully nonlinear equations and the analytical approximation is found downstream of the boundary-layer region. Comparison of results for different sheet aperture angles is performed, confirming a significant reduction of the saturation length with the increase of the aperture angle.