Development and energy analysis of a solar-assisted air conditioning system for energy saving

This paper proposes and analyzes a novel solar-assisted air conditioning system integrating a parabolic trough concentrator coupled to a vapor compression refrigeration cycle operating on environmentally friendly refrigerants. This system, designed to allow relatively high temperatures to be reached thanks to the concentrator, makes it possible to valorize solar energy by expanding the compressed and superheated working fluid in a power sub-cycle. The research aims to evaluate system performances and the energy savings achievable following an energy analysis under different operating conditions. Simulation of the developed system model using EES software showed that the best-performing fluid is R123, followed by R1233zd(E), out of the fifteen candidate fluids. In the absence of solar irradiation, the system operates according to the conventional compression refrigeration cycle, while in the presence of solar irradiation of up to 1000 W/m2, the system operates in a combined cycle with solar backup. In the latter case, this results in energy savings of about 25.3% and 43.8% when the system operates with condensation temperatures of 40 degrees C and 35 degrees C, respectively. An optimal mass fraction model of fluid deviating in the solar sub-cycle was also analyzed. The effect of evaporation temperature on generated energy savings has also been analyzed.