Enhancing the performance of an integrated CCHP system including ORC, Kalina, and refrigeration cycles through employing TEG: 3E analysis and multi-criteria optimization

Abstract

In the current work thermodynamic modeling, exergo-economic and multi-objective optimization of an integrated geothermal based CCHP system coupled with thermoelectric generator is examined. A numerical simulation in the Engineering Equation Solver (EES) is developed to simulate the behavior of the CCHP/TEG integrated system. Exergo-economic modeling to find the cost formation of different streams is done and parametric study with considering different thermodynamic and economic criteria is performed. Thermodynamic analysis reveal that the net output power and total useful products are 139.7 kW and 807 kW. Moreover, the energy and exergy efficiency of the considered system is 55.81 % and 22.63 %, respectively. Parametric study on the CCHP/TEG system for net output power, exergy efficiency, electrical cost rate, and total useful products is carried out. Regarding parametric study the multi-objective optimization with exergy efficiency and electrical cost rate is done. The concept of ideal point is employed to determine the final optimum conditions of CCHP/TEG system. The optimization calculations show that in the final optimum values of the electrical cost rate and exergy efficiency of the system are 12.52 $/h and 22.11 %, respectively. In addition the optimization process indicates that the optimum turbine inlet pressure and separation I inlet temperature are around 8 bars and 13 bars.