IMPROVING PERFORMANCE AND THERMOECONOMIC OPTIMIZATION OF AN EXISTING BINARY GEOTHERMAL POWER PLANT: A CASE STUDY.

Geothermal power plants have been in operation for decades in many parts of the world. Different thermodynamic cycles can be used for producing power from geothermal resources. Binary cycle plants use the geothermal water from liquid-dominated resources at relatively low temperatures. These plants operate on a Rankine cycle with a binary working fluid (isobutane, pentane, isopentane, R-114, etc.) that has a low boiling temperature. A case study on an existing binary geothermal power plant is available in this study. Thermoeconomic performance evaluation and optimization of 2.7 MW binary organic Rankine cycle (ORC) design geothermal power plant in western Turkey is conducted using actual plant operating data, and potential improvements are identified. Afyon Geothermal Power Plant (AFJES) is thermodynamically modeled in a computer environment using current working parameters in a comprehensive way for the use of geothermal energy in electricity generation. Geothermal water temperature and mass flow rate of the plant are 110°C, and 150 kg/s, respectively. Energy and exergy efficiencies of the plant are calculated as 10.4% and 29.7%. The potential annual revenue of geothermal electricity is calculated to be 2,880,277 $/yr with a simple payback period of 3.36 years. The exergetic cost of the electricity from the plant is calculated as 0.0233 $/kWh. The optimized simple payback period and exergy cost of the electricity generated in the plant is calculated as 2.87 years and 0.0176 $/kWh, respectively. [ABSTRACT FROM AUTHOR]