Purification of seawater using absorption heat transformers with water-(LiBr+LiI+LiNO 3+LiCl) and low temperature heat sources

Abstract

The potential of the fluid mixture water-(LiBr+LiI+LiNO 3+LiC1) is studied by numerical simulation for purification of seawater using single-stage absorption heat transformer. The multi-component salt mixture shows a considerably higher solubility than that of the conventional working fluid water-LiBr and it is also less corrosive. The thermal operating conditions considered in the simulation correspond to heat delivered for water purification by an absorber operating at 100°C, waste heat supplied to the generator and the evaporator operating at temperatures ranged from 60 to 80°C, heat sink cooling the condenser operating at a temperature between 10 and 40°C. The results show better performance of the integrated absorption heat transformer water purification system using the working fluid water-(LiBr+LiI+LiNO 3+LiCI) compared with the system using water-LiBr. The enthalpy-based coefficient of performance is higher and remains almost constant as the condensation temperature increases at the considered thermal operating conditions of the cycle. The wider range of solubility of the multi-component salt solution makes possible the operation of the heat transformer cycle at higher concentrations of the strong solution.