Modification and Testing of Vapour Absorption Refrigeration System

In the case of vapour compression refrigeration systems mechanical energy is used to drive the system but the vapour absorption refrigeration systems use heat energy instead of mechanical energy. In this study 40 L capacity commercially available three fluid vapour absorption refrigerator working on electricity was procured and it was modified for using heat energy. The performance of the developed VARS was tested using various heat energy sources such as hot water below 100°C, water at 100°C, steam at 103°C, 106°C, 116°C and 121°C and electric heater that produced temperature 150°C. Performance of the system was evaluated by measuring the generator temperature, ice tray temperature and refrigerator cabin temperature. In these cases hot water below 100°C, hot water at 100°C and steam at 103°C, 106°C could not produce any cooling effect as the generator temperatures were below 100°C. It was found that heating mediums producing temperature below 110°C was not suitable for producing refrigeration effect. Steam at 116°C and 121°C and electric heater at 150°C produced refrigeration effect because while using these heating mediums generator temperatures above 100°C were obtained. Generator temperature above 100°C was required for effective working of bubble pump and separation of ammonia refrigerant from aqua-ammonia solution.