Energy conversion processes based on supercritical carbon dioxide (sCO2) are being investigated in the field of scientific and industrial power engineering due to the great potential in terms of compactness and efficiency.

The working fluid CO2 poses a number of challenges for turbine design and aerodynamic optimization. Due to the high density of the working fluid CO2, which is associated with high losses at high velocities, special attention must be paid to aerodynamic optimization. In addition, fluid density can affect rotordynamic stability. The significantly higher demands on seals, both within the turbine and for sealing against the environment, require new sealing concepts that meet the requirements for performance and operational safety.

In this paper the development of an axial turbine for a demo plant application in an industrial environment is discussed in terms of topology, technology and optimization approaches and the resulting design concept is presented. Aero-and rotodynamic details of the specific challenges coming from the working fluid CO2 are discussed as well as material aspects and the system integration in a power cycle concept. Furthermore, the scalability to larger power output and process temperatures is described.