New Multi-Stage Centrifugal Turbines for Power Plant Driven By Solar Energy

Due to continuously increasing oil prices, global warming concern and depletion of fossil fuels need to be considered as vital issues and requires direct exploration for alternative sources of energy. Therefore, organic Rankine cycle can be probably considered as one of the most flexible technologies in terms of power level capacity and the required heat source temperature. This study explores the performance of unconventional two-stage expander type of radial-outflow turbine for organic Rankine power system where the expander is considered as the heart of the power system. The main aim of the current work is to present new study based on the computational fluid dynamic using ANSYS-CFX to evaluate the performance of a small-scale two-stage expander for ORC system and fluid dynamic characterization of the flow through the flow passages inside the expander stage. The simulations results showed that the expander isentropic efficiency was around 76.1% which is slightly less than 1.5% delivered from mean-line design using zTurbo. While, the maximum deviation with the obtained efficiency from mean-line design based on thermodynamic analysis at mid-span was 2.2% compared with computational fluid dynamic simulations results. This deviation is due to the tip leakage and complexity of flow that it can't be captured by one-dimensional analysis