Thermo-Economic Analysis of Solar-Powered Trigeneration System With Integrated Ejector-Absorption Recompression and Modified Organic Rankine Cycle

Abstract

In this study, the organic Rankine cycle (ORC) and hybrid absorption recompression cycle have been modified by the addition of turbine bleeding with regeneration and ejector, making it a unique solar-powered trigeneration system. With this modification, the useful electric power increases by 65 kW due to increased mass flowrate and overall efficiency nearly by 0.7%, and this difference grows as direct normal irradiation (DNI) rises. After identifying these improvements, a parametric study was conducted to determine the optimum value of these operating variables, such as direct normal irradiation, condenser pressure, turbine inlet temperature, and pressure ratio based on the desired outputs and efficiencies of the proposed modified systems. The results indicate that the proposed system is capable of simultaneously generating 315.3 kW of electric power, 1588 kW of heating output, and 501.6 kW of cooling at energy and exergy efficiencies of 80.8% and 25.36%, respectively. Further, in terms of energy one could conclude that only 19.2% of total available energy is getting wasted, but in reality, around 75% of the work potential of the input exergy is getting wasted. The maximum exergy is lost at the solar collector and destructed at heat recovery vapor generator (HRVG), hence requiring careful design to improve their performance. Lastly, an economic analysis of the proposed system has also been conducted, and the payback period is found to be 2.33 years, which ensures its economic viability.