A novel tri-generation energy system integrating solar energy and industrial waste heat

Abstract

Global warming has forced researchers to find an alternative for fossil fuels and to enhance the energy efficiency of processes in industries. Waste heat recovery has a significant potential to reduce fossil fuel consumption and energy performance enhancement. The study cycle is a tri-generation system, heating, electrical power, that can capture carbon dioxide gas. The system works with the solar energy and waste heat of the cement plant. In this study, a model for a completely new system has been developed based on renewable energies. Thermodynamic analysis for the energy system is performed, and the system is based on the organic Rankine cycle, absorption chiller, solar energy, and waste heat recovery from the exhaust gases of the cement plant stacks. The results of the analysis showed that the energy and exergy efficiencies were calculated to be 35.78% and 12.77%, respectively, and the total exergy destruction was calculated 277327 kW. Also, the optimisation result with the direct algorithm method with the objective function of exergy efficiency improved both efficiencies. In this optimisation, the exergy efficiency reached 16.39% and energy efficiency was calculated 49.04%. The optimisation with the objective function of total exergy destruction decreased the value to 216813 kW, which was significantly reduced from the base state of the system; while energy and exergy efficiencies were calculated to be 54.61% and 13.85%, respectively.