A comparison between ammonia-water and water-lithium bromide solutions in vapor absorption refrigeration systems

Abstract

The study included an investigation to analyze the Vapor Absorption Refrigeration (VAR) systems using ammonia-water and water-lithium bromide solutions. A fundamental VAR system is described and the operating sequence is explained. Since the most common VAR systems use ammonia-water solution with ammonia as the refrigerant and water-lithium bromide solution with water as the refrigerant, the comparison of the two is presented in respect of the coefficient of performance (COP), the cooling capacity and the maximum and minimum system pressures. It is concluded that the VAR system using water-lithium bromide solution provided better performance than the system using ammonia-water solution. However, there are some points to be considered such as; the danger of crystallization and impossibility of operating in very low temperatures because of the use of water as the refrigerant.