Abstract:
In this paper, a new small-scale lithium bromide (LiBr)-water absorption system consisting
water-cooled absorber and air-cooled condenser is experimentally studied. For compactness, the heat exchangers for evaporator, absorber, and generator are made helicalcoiled type, whereas based on the water availability and load requirements, condenser is
air-cooled. Accurate empirical correlations for thermal load and evaporator temperature
against the concerning system driving factors have been reported. Response surface analyses of the performance parameters are studied with respect to LiBr concentration, temperature of generator, and mass flowrate of hot water. Using experimental data, the
estimation of overall heat transfer coefficient (U) and its variation with system driving
factors is quantified. The error margin between theoretical and actual pressure loss is
limited within 5%. Next, a multi-objective inverse analysis of the developed system is
done to simultaneously retrieve the required LiBr concentration, mass flowrate of hot
water, and vapor generator temperature to derive a desired cooling performance
demand from the system. The physics related to salt concentration and generator temperature in governing U values are reported. It can be established that the necessary operational
parameters can be predicted by the present multi-objective inverse method to meet the necessary thermal load and temperature demands within an accuracy level of 6% and 5%,
respectively
