Investigation of Factors That Contribute to Deposition Formation on Turbine Components in a High-Pressure Combustion Facility

Abstract

Researchers at West Virginia University worked with the U.S. Department of Energy, National Energy Technology Laboratory (NETL) to study particulate deposition in a high-pressure and high-temperature environment. To simulate deposition of particulate from combustion of coal synthesis gas on the pressure side of an Integrated Gasification Combined Cycle (IGCC) turbine first stage vane, angled film-cooled thermal barrier coated (TBC) test articles scaled to turbine flow conditions using Reynolds similarity were subjected to accelerated deposition at a pressure of approximately 4 bar and a gas temperature ranging from 1373–1560K. The effects on deposition rates of five different factors were examined; free stream temperature, impaction angle, blowing ratio, particulate loading, and TBC vs. non-TBC coated surface. As the freestream temperature increased the results showed that the deposition also increased. The amount of deposition increased as the impaction angle increased from 10° to 20°. The effect of blowing ratio (M, mass flux ratio) was examined at M = 0.0, 0.25 and 1.0. As the blowing ratio increased the amount of deposition decreased. The particulate loading was varied from 100 ppmw to 200 ppmw. The amount of deposition increased with the higher particulate loading case; however, coverage on the test article face did not increase significantly. Finally, a comparison test was performed between a TBC coated test article and a bare metal test article. This test showed that more deposition formed on the TBC coated article than the bare metal article. During testing, the deposition that formed on the TBC coated test articles demonstrated a resistance to adhering to the surface once the mainstream temperature was reduced during facility shut down. The results of this work will aid gas turbine manufacturers to better understand and develop mitigations for the five factors studied that cause deposit formations in IGCC engines. This work will also give insight to researchers studying deposition on the methods developed and issues encountered in simulating particulate matter into a high-pressure combustion facility.