Suggested solution concentration for an energy-efficient refrigeration system combined with condensation heat-driven liquid desiccant cycle

This paper presents a hybrid energy-efficient refrigeration system enhanced by liquid desiccant evaporative cooling technology for subcooling the refrigerant, where the liquid desiccant cycle is driven by the exhausted heat from the condenser and three commonly used liquid desiccants: LiCl, LiBr and CaCl2 aqueous solutions are considered here. The solution concentration for the proposed hybrid energy-efficient refrigeration system should be determined and optimized carefully for better performance. Sensitive study of solution concentration involved in the hybrid system is conducted at different condensation temperature. The results indicates that under standard working condition (i.e., condensing temperature is 50 °C), the optimum solution concentration is 0.31 for LiCl aqueous solution, 0.45 for LiBr aqueous solution and 0.42 for CaCl2 aqueous solution, while the maximum COPs are nearly same. When the condensing temperature is 45 °C, the optimum solution concentration should be set at 0.27 for LiCl aqueous solution, and 0.41 for LiBr aqueous solution and 0.37 for CaCl2 aqueous solution, while condensing temperature is 55 °C, it is 0.35 for LiCl aqueous solution, 0.49 for LiBr aqueous solution and 0.45 for CaCl2 aqueous solution. The simple fitting formulas are obtained, and performance improvement potential is discussed.