Performance Assessment of Solar Parabolic Trough Collector-Assisted Combined Organic Rankine Cycle and Triple Pressure Level Ejector-Absorption Refrigeration Cycle

A novel solar-assisted combined power and cooling system comprising a parabolic trough collector (PTC) assisted organic Rankine cycle (ORC) and ejector-absorption cooling cycle (EARC) is presented and analyzed in this paper. The use of Ammonia-Lithium Nitrate (NH3-LiNO3) as the working pair in EARC is investigated. First and second law thermodynamics analysis revealed that PTC accounted for 60-80% of the total exergy destruction. Using different ORC fluids revealed that Toluene showed the best performance. The energy utilization factor of Toluene is found to be 25.31% at turbine inlet temperature of 550 K and solar irradiation of 1 kW/m2, whereas for other ORC fluids like R134a (tetrafluoroethane, CH2FCF3), R245fa (pentafluoropropane, CF3CH2CHF2), n-pentane, R410a (near azeotropic mixture of difluoromethane, CH2F2 and pentafluoroethane, C2HF5), it was found to be 17-20%. The exergy efficiency of the combined system using Toluene has reached up to 17%, while the rest of the ORC fluids exhibited 8-12% exergy efficiency. The pump power consumption was significantly reduced due to the use of the ejector in the EARC. Generator temperature and solution heat exchanger (SHX) effectiveness were also found to highly influence the performance of the refrigeration system.