There is considerable interest in Supercritical CO2 cycles for power generation as this can be used as a compact system for low temperature energy recovery applications. However, supercritical CO2 fluid properties are highly non-ideal around the critical point. Correct modelingof the real gas effects is critical in successful modelingand design of compressor and turbines for supercritical CO2 applications.
By using this approach, the 3D inverse design method, TURBOdesign1, can be extended to design of Supercritical CO2 compressor and turbine. In the paper a centrifugal compressor stage and a radial turbine stage for 10 MW recompression SCO2 cycle are designed by using different modules in TURBOdesign Suite such as TURBOdesign Pre for meanline design, TURBOdesign1 for 3D inverse design of the blade and TURBOdesign Volute for the design of the scroll geometry. TURBOdesign1 not only computes the blade geometry for a given loading distribution. But it also generates an accurate 3D flow field. In the figure the prediction of the surface pressure at the shroud of centrifugal compressor impeller designed for SCO2 is compared with CFD prediction from ANSYS CFX. Both TURBOdesign1 and ANSYS CFX use RGP table for look up of the SCO2 properties. The close comparison in the figure confirms the accuracy of the real gas model implemented in TURBOdesign1.