Development and thermodynamic analysis of a novel parabolic trough collector (PTC) based solar-assisted air conditioning system for environmental and energy efficiency interests

Abstract

In the context of valuing solar thermal energy and reducing electricity consumption linked to thermal comfort in buildings, a solar air conditioning system has been studied for environmental and energy efficiency interests. This research aims to model and evaluate the energy savings achievable from a novel developed parabolic trough collector (PTC) based solar-assisted air conditioning system. The system modeling is done following an energy and exergy approach, followed by simulation using the EES software for fifteen candidate refrigerants. Based on model simulations, R123 is the fluid best suited to this design in terms of performance, followed by R1233zd(E). Under conditions of maximum irradiation of 1000W/m 2 , simulation results show achievable energy savings and COP of 45.41% and 7.56 respectively, for a cooling capacity of 736W. The effect of solar radiation level and expansion ratio on system performance was analyzed, demonstrating the benefits of solar thermal assistance by coupling an open Joule cycle to the conventional vapour compression refrigeration cycle. The exergetic analysis revealed that the PTC absorber appears to be the component with the greatest exergy destruction, followed by the condenser. Hence the importance of cooling the latter by means of a water loop, possibly with heat recovery for domestic hot water requirements. Finally, the environmental impact simulation based on TEWI model showed that the proposed system reduces CO 2 emissions by about 27%, compared with a conventional air conditioning system.