Thermoeconomic Investigation and Multi-Objective Optimization of a Novel Efficient Solar Tower Power Plant Based on Supercritical Brayton Cycle with Inlet Cooling

The solar tower power plant technology offers a promising potential for large scale power generation, amongst various solar-based systems. To decrease the produced electricity cost in these systems, development of novel efficient power generation units is essential. In this respect, an innovative combined cycle based on supercritical Brayton cycle with helium working media is proposed in this work. In the proposed scheme, the conventional Brayton cycle is combined with organic Rankine cycle and absorption chiller for waste heat recovery. The produced cooling by the absorption chiller is used to cool the compressor inlet gas. Thermodynamic and economic analyses and multi-objective optimization are implemented based on the exergy efficiency and electricity cost as the objectives. Also, the system performance is assessed for different values of solar radiation based on actual data. As a remarkable outcome it is found that, the electricity cost is lower for the proposed combined cycle despite the added costs associated with the bottoming cycles. Under optimum conditions, the exergy efficiency and electricity cost of the combined cycle were improved by 14.5% and 11.9% compared to the basic system, respectively. Also, a comparison with similar previous literature has shown that the present system has better performance than the supercritical CO2 and Rankine cycle-based systems.