Thermoeconomic analysis and multi-objective optimization of a high-performance system based-on gas turbine and Rankine equipped with thermoelectric generator cycles

Increasing energy consumption has led to the use of renewable energy sources to reduce environmental pollution and prevent global warming. The present work has been carried out with the aim of presenting and investigating a new combined cycle based on the gas turbine with biogas fuel and due to the high outlet temperature of the gas turbine, a steam Rankine cycle equipped with open feed water heater and the thermoelectric generator has been combined with it as the bottom cycle. The system is studied based on the variables of air compressor pressure ratio and air preheater temperature efficiency and analyzed from the viewpoint of the first and second laws of thermodynamics and thermo-economics. Also, to find the best-operating conditions, the system is optimized using the genetic algorithm in EES software by employing single and multi-objective optimization. The results showed that the thermal and exergy efficiencies in the base condition are 44.58 and 42.38%, respectively, and in the optimum thermo-economic condition are 49.45 and 47.01%, respectively. In addition, the LCOE in the multi-objective optimization condition was calculated at 17.50 $/GJ, which is 5.1% lower than the baseline.