Off-Design Modelling of ORC Turbines for Geothermal Application

In this study, turbine modelling of a geothermal sourced organic Rankine cycle (ORC) power plant is aimed. Thermodynamic model the constructed with help design and off-design data from an existing two-cycle in southwestern Anatolia. Utilizing statistical analysis tools such as maximum likelihood estimation probability distribution, variables are obtained within their standard deviations. Stodola curves calculations demonstrate that both turbines most likely to have two stages. Average losses 2.3 MW 1.2 Turbine-I Turbine-II respectively throughout different seasons. After determination losses, overall efficiencies reverse trend increasing reduced mass flow rate. This may be associated increased choking turbine. Correlations estimate rather fixed efficiency values at conditions (84% for 77% Turbine-II); expected outcome since these correlations influenced mainly by isentropic efficiency, which constant value. On other hand, proposed non-choking invalid ORC turbines. Datapoint dispersion does not strong correlation physical constraints -pressure ratio rate- it Turbine-I; phenomenon need further attention future work.