Solar based CO2 power cycle employing thermoelectric generator and absorption refrigeration: Thermodynamic assessment and multi-objective optimization

A novel integrated power generation and refrigeration system proposed in this paper. The system consists of parabolic trough collectors, supercritical-CO2 based Brayton cycle, an absorption refrigeration cycle, and a thermoelectric generator. Of particular interests of this paper are thermoelectric power generator and performance characteristic of closed Brayton cycle working with CO2. Employing energy and exergy analyses, the effect of integrating thermoelectric module at different points is studied by comparing power generation and efficiency before and after applying the thermoelectric module. Besides, the whole system is analyzed with the use of first and second law thermodynamics to determine energy and exergy efficiencies with exergy destruction rates. Furthermore, a multi-objective optimization method is conducted by defining two scenarios using different types of objective functions to specify the optimum conditions of the system with the thermoelectric module. According to the results, the energy and exergy efficiencies of the system are increased by 1% with the presence of the thermoelectric module. In addition, employing thermoelectric lead to the generation of 4.81 kW power from waste energy in different locations of systems.