Experimental Testing of the Water Distillation System with Regard to Heat and Cooling Generation by Means of Reversible Thermochemical Reactions

The paper presents the results of an experimental study on the exothermal heat and endothermal cooling generation under vacuum conditions using a water distillation system of special design. The heat and cooling are generated when KOH and NH4NO3 crystals are dissolved as a result of natural mixing in the water, distilled from NH4NO3 and KOH liquid solutions, respectively. The time evolutions of the temperatures measured in KOH→H2O→NH4NO3 and NH4NO3→H2O→KOH experiments are presented and discussed. It has been shown that under vacuum conditions, the endothermal effect of NH4NO3 dissolution in water is stronger than that observed at atmospheric pressure, while the exothermal effect of KOH dissolution in water is weaker. The experimental results obtained will be used to develop the dual thermochemical heat storage and cooling generating system in order to utilize solar heat in the summer.