The evaporative desalination system using solar thermal energy would be very efficient and attractive method to get fresh water from brine due to low carbon dioxide generation. In this research the solar desalination system as a heating source of refrigerant R123 and R141b in the evaporator was considered. The circulation of refrigerant in the evaporator can reduce the energy consumption of the system, through using the latent heat of the refrigerant instead of the sensible heat of present warm water.
The system was composed of the single-stage fresh water production unit of 1 ton/day capacity with shell and tube type evaporator, heaters instead of solar collector for supplying proper heat to refrigerant, and refrigerant circulation system.
Various operating flow rate and temperature ranges were imposed on the experiments to get the optimum design data. The experimental results showed that the optimum flow rate of brine feed to evaporator was 1.2Liter/min of R123 and 1.0Liter/min of R141b, and the yield of fresh water increased with brine temperature rise.
It was confirmed that the flow rate of heating source of refrigerant as heating source decreased down to one fifth that of the present warm water system, and it was proven to be very efficient system for solar desalination.