International Journal of Exergy | 2021
Energy, exergy, and exergo-economic analyses of a novel three-generation system to produce power, heat and distillated water
Abstract
In this study, energy, exergy, and exergo-economic analyses were conducted for a new system producing power, heat, and distilled water. First, the waste heat of a gas turbine was recovered by a heat recovery steam generator, and then by an organic Rankine cycle. Simultaneously, a geothermal energy resource was utilised for re-heating the organic fluid to increase the power and efficiency of the ORC. Moreover, this system encompasses a reverse osmosis desalination unit to produce freshwater. Feed-water is heated in the condenser before it enters into the desalination unit; hence, specific power consumption of the high-pressure pump reduces by 43.52%. Exergy efficiency of the system was estimated to be 53.86%, where was 5% higher than basic mode (i.e., with no desalination unit and re-heating). The exergo-economic factor was 12.14%, suggesting that exergy destruction accounts for a high proportion of costs.