THERMODYNAMIC ANALYSIS OF TWO-STAGE VAPOUR COMPRESSION REFRIGERATION SYSTEM INTEGRATED WITH AN ABSORPTION SYSTEM (LiBr-H2O)

Abstract

This work comprises energetic and exergetic analysis of two thermodynamic cycles: First one is a conventional two stage cooling system by steam compression of ammonia and the other is named integrated refrigeration system. The conventional system that has been used as reference in this work is largely used for cooling purpose in industrial sector. The integrated refrigeration system is similar to the conventional system, but it uses the intermediate cooling, between the stages of high and low pressure, by cold water in closed circuit. The cold water is supplied by LiBr-H2O absorption system integrated to the conventional compression system. The heat input is obtained from waste material. Therefore, the energy supplied to the integrated refrigeration system is assumed of zero cost. Numeric simulation is used to compare the behaviour of both cycles. The results obtained in this comparison show that the integrated refrigeration system operates with a reduction of up to 9.70 % in COP. However, the integrated refrigeration system presented an increase of up to 11.89% in exergetic efficiency and 34.46% in refrigerating capacity in relation to the conventional system. These results, together with decrease in operational cost which will be valuable in further study, will make very attractive the use of the integrated refrigeration system.