Thermal comparison and multi-objective optimization of single-stage aqua-ammonia absorption cooling system powered by different solar collectors

This paper presents the comprehensive thermodynamic modelling to compare the performance and optimization of single-stage NH3-H2O-type absorption cooling system integrated with different solar collector types for the city of Mehsana, India. A 20-kW system at 0 A degrees C is analysed which includes four different solar collectors flat-plate collectors, parabolic-trough collectors (PTC), flat plate with compound parabolic collector reflectors and evacuated-tube collectors (ETC) attached with insulated thermal storage tank to power the NH3-H2O vapour absorption system. The study investigated the effect of heat source temperature on performance aspects of systems. The examined performance parameters are exergetic efficiency, coefficient of performance and area of collector. Exergetic optimization of each system estimated the optimum collecting area requirement for cooling. Differentiation between optimized systems determined that the optimum cost, SCOP and eta (II,system) of PTC-type system are averagely 30, 11 and 0.5% higher than ETC-type system at different ambient temperatures. For effective comparison and conclusion, key performance indicator is evaluated to select optimum system configuration from both thermodynamic and economic criteria.