An analytical model for coupled heat and mass transfer processes in solar collector/regenerator using liquid desiccant

Abstract

Solar collector/regenerator (C/R) using liquid desiccant combines solar photothermic transformation and regeneration of liquid desiccant together, effectively achieving the regeneration for solar energy-driven liquid desiccant cooling systems. In this paper a group of dimensionless heat and mass transfer equations describing the heat and mass transfer process in the solar C/R were obtained by introducing total temperature difference ( Δ T 0 ) and dimensionless heat loss coefficient ( h ¯ z ) . For the sake of predicting the heat loss of air stream and simplifying calculation, the models of dimensionless air temperature ( θ a ) and equilibrium humidity ratio ( Y eL ) along with the height of solar C/R were put forward. An analytical solution was formed by two differential equations on the dimensionless heat and mass transfer driving potentials and the heat and mass conservation equations. Compared with the numerical simulation results, the analytical results on the outlet parameters of solar C/R have great precision with different Lewis factor Le , total temperature difference Δ T 0 and air-to salt mass flow rate ratio ASMR . Simultaneously, the effects of above variables on the regeneration performance were analyzed. Lastly, by comparing with the experimental data, the analytical calculation results can agree well with the experimental results validating the analytical model is an ideal way for predicting the performance of the solar C/R.