Studies on an air-cooled gax based ammonia-water vapour absorption refrigeration system

Abstract

The improvement in the quality of life has increased the demand for Refrigeration and Air-conditioning 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. This thesis presents both the theoretical and experimental investigations on the air-cooled modified generator-absorber heat exchange based vapour absorption refrigeration system, using ammonia-water as the working fluid. The thermodynamic and transport properties of the working fluid are essential for the theoretical analysis and proper design of the components of the system. Hence, these properties for the refrigerant-absorbent solution are collected and compiled. The graphical method of pinch point analysis is employed to obtain the required heating and cooling utility. Thermodynamic analysis of both the conventional and the modified cycles has been carried out. Based on the outcome of thermodynamic simulation, an experimental set up of an air-cooled modified generator-absorber heat exchange based vapour absorption refrigeration system of 10.5 kW cooling capacity, has been built with 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.