Abstract
Supercritical CO2 Brayton cycles are considered by some as the next evolution in power generation. The question of cooling effectiveness for hot gas path components arises for this topic. In this work, a stage one vane was designed with an internal cooling scheme which consisted of a turbulated three-pass serpentine which fed a trailing-edge pin fin bank with pressure-side cutback trailing-edge slot extraction. A conjugate heat transfer analysis, with practical supercritical CO2 boundary conditions, was performed on the design with Rene 80 as the metal. The conjugate heat transfer model had a thermal barrier coating which consisted of 0.1 mm of NiCrAlY bond coat and 0.3 mm of YSZ. The investigation consisted of a construction of a relationship between cooling effectiveness and heat load parameter, internal cooling turn losses, external airfoil temperature profiles and a thermal boundary layer analysis at areas of interest. A recommendation for internal turn inlet-apex-outlet area ratios is provided for minimizing the dynamic pressure loss associated with the turn. The study concluded that heat transfer not only depends on buffer zone temperature, but also viscous sublayer thickness.
