Exergy and exergoeconomic analyses and optimization of geothermal organic Rankine cycle

This paper presents thermodynamic and economic analyses on a novel-type geothermal regenerative organic Rankine cycle based on both energy and exergy concepts. An optimization study is also performed based on the heat exchangers total surface area parameter. Parametric studies are performed to investigate the effect of operating parameters, and their effects on the system energetic and exergetic efficiencies and economic parameters are investigated. The energy and exergy efficiency values are found to be 16.37% and 48.8%, respectively, for optimum operating conditions at a reasonable rejection temperature range of the geothermal water from 78.49 °C to 116.2 °C. The mass flow rates of the organic fluid, cooling water and provided geothermal water are calculated for a net out power of 5 MWe.