• discretization
• solar absorption cooling systems
• working pair

The purpose of this work is to investigate the potential of using PTC (parabolic trough collector) technology for the direct evaporation of ammonia from a solution of ammonia-lithium nitrate in absorption cooling systems. This system solution, currently under study by the research group ITEA of the University Carlos III of Madrid, allows eliminating the use of heat transfer fluids (thermal oil, pressurized water, etc.), thus entailing benefits as regards the overall efficiency, the environmental protection and the reduction of the installation costs. After a general overview of solar absorption cooling applications, a one-dimensional, stratified, two-phase flow model in steady state conditions has been developed. The resulting set of equations was subsequently discretized and then solved using the calculation software Mathcad 14.0. Finally, the results, obtained for different varying input values, were reported and commented.