HEAT AND MASS TRANSFER IN LiNO_3-NH_3 SPRAY ABSORPTION SYSTEM

摘要

In the present work the spray absorption method is studied for the absorption of ammonia refrigerant vapour by lithium nitrate - ammonia solutions. Heat and mass transfer coefficients attainable using the spray absorption method are estimated. In this study the low-pressure absorber of a double-stage absorption refrigeration system is considered. The results show that a mass transfer coefficient equal to k_m = 18.6·10~(-5) m/s may be attained. The heat transfer coefficient (5.8 kW/m~2K) obtained in the heat exchanger using the spray absorption method and the lithium nitrate - ammonia solution is one order of magnitude higher than those obtained using falling film absorbers. This would lead to significantly smaller heat exchanger areas in absorption chillers.