Design and performance analysis of 1KW ORC turboexpander with R245fa as working fluid

Organic Rankine Cycle (ORC) is a reliable technology to utilize low and medium thermal energy and has been in development since the beginning of the 19th century and has rapid development in the last few decades. There are a couple of ways to optimize ORC. One of them is to develop an optimized turboexpander. This paper will explain in detail the preliminary and detailed design approach used to design turboexpander for 1kW ORC with R245fa as working fluid. The numerical simulation was performed using ANSYS CFX with turbulence model of Eddy Viscosity Reynold Shear Stress and Aungier Redlich-Kwong Equation of state to predict the material properties. A couple of adjustments had been made when deciding the rotor thickness and blade number, as the proposed method was not able to produce reasonable geometry. The CFD result of the preliminary design has 4.79% less efficiency and 22.7% less power produced than the 0D design. The off-design parameters of 16 Blade number, 20000 rpm, and mass flow of 0.32 kg/s able to produce power 1.38 kW with the efficiency of 76.44%