A novel multi-generation energy system based on geothermal energy source: Thermo-economic evaluation and optimization

Abstract

A multi-generation system including an absorption chiller, an organic flash cycle, a concentrated photovoltaic module, a reverse osmosis unit, and thermoelectric modules are integrated to produce cooling, heating, electrical power, and freshwater. The important parameters including energy efficiency, exergy efficiency, exergy destruction rate, net output power, and electrical cost rate are identified. The behavior of main outputs are examined with varying decision variables namely geothermal temperature, flash vessel inlet pressure, and pump Ι outlet pressure. Thermal modeling of the proposed system indicates that the energy efficiency, exergy efficiency, and net output power are 5.46%, 20.16%, and 70.85 kW higher than the conventional system. Moreover, exergo-economic outputs demonstrate that the thermoelectric generator module with 11.34 $/h and heat exchanger 2 with 8.98 $/h have the maximum exergy destruction cost rate. Finally, according to different multi-objective optimization scenarios it is found that through the first scenario, the electricity cost rate shows the minimum value of 108.4 $/h.