Thermoeconomic analysis of combined steam and organic Rankine cycle with primary mover of Allam cycle

Because of the fossil fuels crisis in recent years, increasing fossil fuel consumption and the oil crisis, energy efficiency is becoming a major concern of the twenty-first century. In this research, the combined cycle of steam Rankine and organic Rankine with the primary mover of the Allam generation cycle has been simulated. The hybrid cycle is configured in such a way that the high temperature waste heat first acts as the steam cycle evaporator and the waste heat output from the steam cycle evaporator is used as the low temperature evaporator of the organic cycle. Then, the effect of changing various parameters such as evaporator temperature and steam cycle condenser pressure on output work values, total irreversibility, energy efficiency, exergy efficiency and exergy-economic variables is investigated. The results show that the energy efficiency and exergy efficiency of the combined cycle are 0.57 and 0.66, respectively, and the amount of output work and total irreversibility are 150,125 kW and 91,237 kW, respectively. Also, according to the study results, a lot of exergy destruction takes place in the system, thus it is recommended to increase the initial price in different components in order to improve the performance of the system. Evaporators and steam cycle condensers are components that should be considered from an exergy-economic perspective, as they have the highest rate for the sum of the initial cost rate and the cost of exergy destruction.