Techno-economic-environmental evaluation of a combined cooling heating and power system for gas turbine waste heat recovery

Abstract With the development of the world economy, the energy crisis and environmental pollution have become global issues. Polygeneration systems, which have the advantages of energy saving and high efficiency, can alleviate them. This work proposed a novel combined cooling, heating, and power system structure composed of a gas turbine cycle, a supercritical CO2 (sCO2) cycle, an absorption refrigeration chiller, a steam generator, an organic Rankine cycle (ORC), and additional thermoelectric generator modules. The techno-economic-environmental performance of the proposed system was discussed through a comparative study of different integrated system structures. A parametric study was also conducted to analyze the effects of important decision variables, and then a multi-objective optimization was conducted to further study the system performance from different objectives. Finally, two different system structures were compared based on the optimal results. The results showed that the thermal efficiency was increased by 0.3% with the presence of a thermoelectric generator under design conditions, but it resulted in a higher cost rate of 0.45 $/h and larger emissions of approximately 0.19 kt CO2,eq. The optimal results revealed that the system had thermal efficiency of 67.88%, exergy efficiency of 42.62%, total cost rate of 10.60 $/h, and total emissions of 923.55 kt CO2,eq. Furthermore, a comparative study found that the proposed system structure exhibited excellent thermodynamic performance but worse economic performance than the integration of the sCO2 cycle and ORC.