Proposal and Assessment of a Novel Multigeneration System Based On A Supercritical CO2 Brayton Cycle Driven by a Solar Power Tower Plant

Supercritical carbon dioxide (s-CO2) Brayton power cycles have been found as a promising candidate for integration with solar power tower plants. Waste heat recovery from s-CO2 Brayton power cycles is a very attractive way for generating multiple useful products. In this work, a novel multigeneration concept is proposed based on an s-CO2 recompression power cycle, driven by a solar power tower, to generate electricity, freshwater, cooling, and hot water for domestic applications concurrently. In the proposed system, the waste energy rejected from a s-CO2 recompression cycle with a 100 MWe capacity is recovered by a multi-effect distillation (MED) plant, a half-effect water-lithium bromide (H2O-LiBr) absorption chiller, and a CO2-water heat exchanger for the generation of freshwater, cooling, and hot water. The thermodynamic analysis results show that the minimum and maximum pressures of the s-CO2 recompression cycle that give the highest thermodynamic efficiency are 84 bar and 270 bar, respectively. For these pressures, if the mass flow of the heat source is split equally between the MED plant and absorption chiller and the system operates at full load condition, 1,366 m(3)/day freshwater and of 3,263 kW cooling effect can be generated. Also, 258 kg/s hot water at 55 degrees C can be generated for domestic applications. The study results demonstrate that the proposed hybrid multi-generation system is an attractive concept to generate multiple useful products and supply the growing demand of the residential sector in a clean manner.