Exergy and thermoeconomic analysis of a combined Allam generation system and absorption cooling system

In recent years, the use of Allam cycle based on the closed cycle of carbon dioxide has been considered by researchers due to its high efficiency and reduction of carbon dioxide emissions in the environment. In the present study, the combined system including Allam cycle and absorption cycle has been investigated from the perspective of energy, exergy and exergy–economy. The use of the absorption cycle is to use the waste heat of the power cycle and increase energy efficiency. The simulation results show that the total exergy efficiency of the cogeneration cycle is 0.72. Turbine, compressor and absorption cycle are introduced as primary components that should be considered from the exergy–economic point of view because they account for the highest cost rate of exergy efficiency. Also, the results of parametric analysis indicate that increasing the compressor pressure ratio has a negative effect on the cycle performance, thus reducing the overall work and efficiency of the exergy as well as increasing the cost rate. Similarly, changing the compressor pressure ratio has the greatest impact on the performance of the combined cycle, so that changing the pressure ratio in the range of 2 to 10 resulted in reducing the exergy efficiency by 63%. The key assessment is that the performance of the system increases as the temperature of the cooled water in the evaporator rises. Exergy efficiency works in contrast to the system performance coefficient and the main reason for the return of imperfections in the absorption cooling system is the undesirable heat transfer in the system heat exchangers.