Proposal and thermodynamic analysis of a Combined Heat and Power system for central receiver solar power plants

The solar energy is one of the most promising options for electricity generation to be replaced for fossil fuels. Solar thermal power plants with central receiver system have major advantages compared to the other concentrating solar power systems. To increase the efficiency of these power plants an efficient power cycle, regarding the high temperature of the heat source, can be employed. Accordingly, in the present work, a combined Brayton-ORC is proposed for co-generation of heat and power. Thermodynamic evaluation including energy and exergy analyses for the power plant is conducted. The results show that the gas turbine inlet temperature and concentration ratio have the largest incremental effect on the both energy and exergy efficiencies. The recuperator has the largest exegy destruction and exergy destructin in ORCs’ pumps is the lowest one. Based on the input data, for the proposed combined cycle, first and second law efficiencies, can reach to 61.34% and 73.28%, respectively.