Vapour absorption refrigeration system

Abstract

The improvement in the quality of life has increased the demand for Refrigeration systems throughout the world. The use of high-grade energy for the operation of these systems is associated with Green House Gas emissions and thermal pollution in the form of waste heat besides depletion of fossil fuels. In this context, vapour absorption refrigeration systems are looked upon with renewed interest as they work on heat operated system with environment friendly working fluids. Heat rejection capacities of these systems are higher than that of electrically operated vapour compression systems. Hence, considerable advantage lies in the use of air-cooled absorber and condenser especially with reference to the small capacity vapour absorption refrigeration units. This eliminates the necessity of a cooling tower and the associated maintenance issues. Utilizing the generator-absorber heat exchange principle in the conventional ammonia-water system reduces the generator heat input and thereby enhancing the system coefficient of performance. This thesis presents both the theoretical and experimental investigations on the air-cooled modified generatorabsorber heat exchange based vapour absorption refrigeration system, using ammonia-water as the working fluid. The feasibility of operating a small capacity (10.5 kW) air-cooled modified generator-absorber heat exchange based vapour absorption refrigeration system using ammonia-water as the working fluid has been established. The performance of the system tested is higher compared to the conventional single effect ammonia-water system. These systems could be employed for cold storage applications in the rural and semi urban areas.