Preliminary design and off-design performance analysis of an Organic Rankine Cycle radial-inflow turbine based on mathematic method and CFD method

As a critical component of Organic Rankine Cycle (ORC) system, the turbine selection has an enormous influence on the system performance. Challenges in the numerical modeling of radial-inflow turbines using high-density working fluids still need to be addressed in order to improve the turbine design and better optimize ORCs. This paper carries out the full design process of the R134a radial-inflow ORC turbine. The 1D design of the candidate radial-inflow turbine is presented in details. Furthermore, commercially-available software ANSYS-CFX is used to perform preliminary steady-state 3D CFD simulations of the candidate R134a radial-inflow turbine. Also a turbine model based on 1D analysis is performed for a number of operating conditions including off-design conditions. The performance prediction codes of an ORC radial-inflow turbine based on mathematic method and CFD method can be used to provide basic data for future detailed design, and predict off-design performance in the initial design phase.