Numerical Simulation of Turboexpander on Organic Rankine Cycle with Different Working Fluids

Abstract

Renewable energy is an alternative to overcome the energy crisis and dependence on fossil-fuel energy that has an environmental impact due to the greenhouse effect. Meanwhile, disadvantage of EBT is depend on weather periodically. Geothermal is a source of EBT that is independent with weather. Geothermal resources dominated by water (brine) can't be directly utilized as a power generated, but it has to separated into water and steam phase. The high enthalpy owned by brine can still be utilized due to development of Organic Rankine Cycle. ORC uses organic refrigerant fluids or hydrocarbons as a working fluid because it has low boiling temperatures. The numerical simulation was analyzed using a CFD ANSYS CFX with turbulence model K-epsilon and Pentane, R245fa, and butane as a working fluids with expansion ratio 5:1 and rotational speed variation at 2000 until 14000 rpm.