CONCENTRATION DIFFERENCE HEAT-PUMP USING FUSION AND FREEZING PROCESSES

This study investigates the possibility of a new method to generate a cold fluid. The method is a concentration difference heat pump using f usion and freezing processes that consist of a cold fluid generating p rocess and a separation process. The operation at the capacity of one ton refrigeration (3.52 kW) has been investigated in this study. In th e cold fluid generating process, ice at 0-degrees-C was fused into an aqueous solution of NaCl at 0-degrees-C, such that the temperature and the concentration of salt of the solution decrease. This dilute solut ion at a lower temperature was used to generate a cold fluid. The lowe st attainable temperature of the solution has been investigated experi mentally, and also calculated from the energy balance equation. The ca lculated results were in good agreement with the experimental results. The decreasing rates of the temperature have also been studied. The d ilute solution was then sent from the cold fluid generating process to the separation process and concentrated by membrane distillation. Mic rotext membrane has been investigated to concentrate the dilute soluti on. The permeate flux was affected by the temperature, concentration, and pressure of the solution. Experimental results showed that good qu ality water was obtained from the separation process using membrane di stillation.