Comprehensive economic analysis and multi-objective optimization of an integrated power and freshwater generation cycle based on flash-binary geothermal and gas turbine cycles

Abstract

This paper proposes a novel hybridization of a flash-binary geothermal cycle, a gas turbine cycle, an organic flash cycle, and a multi-effect desalination subsystem to reach efficient cogeneration of electricity and freshwater using the waste heat recovery concept. The capability of the proposed system is investigated based on energy, exergy, environmental, and economic perspectives. The proposed configuration at the base conditions provides 8016 kW net power, 15.99 kg/s freshwater with 35.43% exergetic efficiency, 110.9 t/kW levelized total emission, and 3.42 y of payback period. The sensitivity analysis is performed to investigate the heat transfer-based equipment's impact on the system's performance criteria. The air preheater effectiveness has the highest impact on the proposed system's performance. The net present value is estimated for different electricity sale prices and geofluid prices. The net present value estimation's results reveal that the electricity sale price affects the system profitably higher than the geofluid purchase cost. The multi-objective optimization based on the grey wolf method is applied through four different scenarios. The proposed system at the best optimum operation state provides 8183 kW net power, 16.11 kg/s freshwater with 36.13% exergetic efficiency, 108.8 t/kW levelized total emission, and a 3.04 y of payback period.