Thermal and economic performance evaluation of a novel sCO₂ recompression Brayton–steam Rankine–absorption cooling system based on solar energy

A novel polygeneration system is designed to provide electricity, heating and cooling capacity on basis of solar energy. Two-stage power cycle of sCO₂ Brayton and steam Rankine is propelled to generate electricity with residual heat transferred to drive an efficient heating device and an intercooled absorption cooling system. System performance is comprehensively analyzed from thermal efficiency in terms of energy and exergy, based on the quasi-steady numerical model. Results indicate that built system obtains electricity, heating and cooling capacity of 243.84, 42.05 and 10.746 MW with energy efficiency of 0.5304, 0.0915 and 0.0234 and exergy efficiency of 0.562, 0.0174 and 0.0024, respectively. Mass flows of working fluids and detailed specifications of solar collecting field are also included in this investigation. Parametric analysis exhibits that operating parameters exert remarkable influence on thermal efficiencies. Proposed system can save amounts of energy over three individual systems with identical products by means of a primary energy saving ratio analysis and energy saving performance is more sensitive to turbine inlet temperature of Brayton. Exergoeconomic evaluation reveals that designed system achieves inferior electricity performance and superior heating and cooling performance in comparison with current circumstance. In conclusion, this novel cogeneration system takes full advantage of solar energy to meet various energy consumptions.