Thermodynamic analysis of combined power cycle, combining heat from a waste heat source with sub-cycles

Abstract

Significantly increasing consumption and demand in conventional fossil energy sources require energy sources to be more efficient and sustainable. In this study, it is aimed to increase the efficiency of the systems by using thermodynamic cycles from waste heat sources. The designed system is aimed at increasing the efficiency of the system by adding sub-cycles of the waste heat of a gas turbine. The results analyzed with the engineering equation solver program, when all the cycles are combined, the system energy efficiency is 75% and the total exergy efficiency is 24%. Brayton cycle when the system is evaluated alone, the energy efficiency of the system is 65%, the exergy efficiency is 14%. The S-CO2 cycle system when the system is evaluated alone, the exergy efficiency is 23% and the exergy efficiency is 11%. The ORC system when the system is evaluated alone, the exergy efficiency is 19% and the exergy efficiency is 22%. Rankine system when the system is evaluated alone, the exergy efficiency is 17% and the exergy efficiency is 88%. Turbine inlet temperatures tend to decrease as the exergy destruction in the system also affects the subcomponents.