One-Dimensional Optimization Design of Supercritical Carbon Dioxide Radial Inflow Turbine and Performance Analysis under Off-Design Conditions

Abstract

In the present study, the one-dimensional optimization design and the performance analysis based on a three-dimensional model were performed for a 2.1 MW supercritical carbon dioxide radial inflow turbine. Firstly, an in-house code was developed with MATLAB language for one-dimensional optimization design to maximize the total-to-static efficiency. Then, the three-dimensional radial inflow turbine model was constructed based on the one-dimensional optimization design result. Finally, the flow field and the aerodynamic performance were studied using the commercial software NUMECA. It is shown that the total-to-static efficiency obtained from three-dimensional simulation under the nominal design condition is 85.77%, with a relative deviation of 0.55%, as compared with that from the one-dimensional optimization design. Furthermore, the static temperature and pressure from the turbine inlet to the outlet drop uniformly, and there is no obvious flow separation under the nominal design condition. The values of total-to-static efficiency are always higher than 75% at the 80–110% relative rotating speed and the expansion ratio of 1.75–4.48, which also demonstrates good performance under the off-design working conditions.