Bearing and Seal Selection for a High-Temperature Supercritical CO2 Turbine

Abstract

Solar power towers using supercritical CO 2 (sCO 2 ) Brayton cycles were proposed as the next-generation Concentrating Solar Thermal (CST) technology. One of the challenges facing rapid deployment of CST using sCO 2 cycles remains to be the power block and, in particular, the lack of reliable sCO 2 turbine technology. The main challenge for sCO 2 turbine designers is in the area of component technologies such as materials, bearings and seals. The combination of high temperatures (above 600 o C), high rotational speeds, and high fluid densities create a perfect storm for sCO 2 turbine designers. This paper investigates appropriate bearings and seals for a sCO 2 radial-in-flow turbine proposed for Concentrating Solar Thermal applications.