Exergetic, energetic and financial evaluation of a solar driven absorption cooling system with various collector types

Solar energy utilization for cooling applications is analyzed in this study. A single effect absorption chiller operating with LiBr-H2O is the cooling sorption machine which is coupled with a collector field. The cooling demand is 100 kW at 10 °C for Athens (Greece) in summer. Four different collector types are tested in order to predict the most suitable solution for this study case. More specifically, flat plate collectors, evacuated tube collectors, compound parabolic collectors and parabolic trough collectors are investigated under the same conditions. An exergetic optimization of every system gives the optimum solution of every case, which leads to minimum collecting area. A financial comparison between the four optimized systems proves that evacuated tube collectors are the most beneficial technology. On the other hand, system with parabolic trough collectors is the exergetic optimum one, but its high capital cost renders it an unprofitable solution. The analysis is made in steady state conditions with Engineer Equator Solver (EES), a very useful energy tool.