Investigation of an ejector-cascaded vapor compression-absorption refrigeration cycle powered by linear fresnel and organic rankine cycle

The low-temperature cooling through the cascade compression-absorption refrigeration system with the solar thermal source is a promising technology to be used in food storage applications. This paper studies an integrated organic rankine cycle (ORC, toluene)/ejector-cascade compression (R1234yf)-absorption (LiBr-H2O) refrigeration system/thermo-electric generator (TEG) powered by the linear Fresnel solar collectors. The power generation of the ORC and TEGs was assumed to supply the electricity consumption of the system. A thermo-economic analysis was performed to determine the influence of different parameters on the system performance, heat transfer areas, solar field, and thermal energy storage (TES) system optimum sizes, and the levelized cost of the cooling energy (COC). The calculations were conducted for three locations to specify the influence of solar radiation level on the system sizes and COC. Based on the results, the energy and exergy efficiencies (eta(I) and eta(II)) vary from 38 to 50% and from 3.6 to 4.6%, respectively. Although the capital investment and complexity are the practical limitations, the cascade cycle coefficient of performance and the system overall efficiency improvement were obtained as 27.02% and 51.19%% over the cycle without ejector and TEG reported in the previous research studies. Also, for three locations with highest, medium, and lowest solar radiation levels, the minimum COC (and annual solar share) was obtained as 0.049-0.062 $/kWh (36-74%), 0.068-0.079 $/kWh (32-55%), and 0.145-0.158 $/kWh (18-27%), respectively, for different TES capacities and capital costs. Moreover, the TEG modules are capable of supplying nearly 27% of the total power consumption of the system. For two regions located in Iran and United Arab Emirates, the COC of the fuel-based system becomes equal to that of the solar-based system if the conventional fuel prices in United Arab Emirates and Iran are increased by 202% and 316%, respectively.