Abstract
While the water vapor content of the combustion gas in natural gas-fired land based turbines is ∼10%, it can be 20-85% with coal-derived (syngas or H2) fuels or innovative turbine concepts for more efficient carbon capture. Additional concepts envisage working fluids with high CO2 contents to facilitate carbon capture and sequestration. To investigate the effects of changes in the gas composition on thermal barrier coating (TBC) lifetime, furnace cycling tests (1 and 100h cycles) were performed in air with 10, 50 and 90 vol.% water vapor and CO2-10%H2O and compared to prior results in dry air or O2. Two types of TBC?s were investigated: (1) diffusion bond coatings (Pt diffusion or Pt-modified aluminide) with commercial electron-beam physical vapor-deposited yttria-stabilized zirconia (YSZ) top coatings on second-generation superalloy N5 and N515 substrates and (2) high velocity oxygen fuel (HVOF) sprayed MCrAlYHfSi bond coatings with air-plasma sprayed YSZ top coatings on superalloys X4, 1483 or 247 substrates. For both types of coatings exposed in 1h cycles, the addition of water vapor resulted in a decrease in coating lifetime, except for Pt diffusion coatings which were unaffected by the environment. In 100h cycles, environment was less critical, perhaps because coating failure was chemical (i.e. due to interdiffusion) rather than mechanical. In both 1h and 100h cycles, CO2 did not appear to have any negative effect on coating lifetime.
| Original language | English |
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| Title of host publication | Ceramics; Controls, Diagnostics and Instrumentation; Education; Manufacturing Materials and Metallurgy; Honors and Awards |
| Publisher | American Society of Mechanical Engineers (ASME) |
| ISBN (Electronic) | 9780791856758 |
| DOIs | |
| State | Published - 2015 |
| Event | ASME Turbo Expo 2015: Turbine Technical Conference and Exposition, GT 2015 - Montreal, Canada Duration: Jun 15 2015 → Jun 19 2015 |
Publication series
| Name | Proceedings of the ASME Turbo Expo |
|---|---|
| Volume | 6 |
Conference
| Conference | ASME Turbo Expo 2015: Turbine Technical Conference and Exposition, GT 2015 |
|---|---|
| Country/Territory | Canada |
| City | Montreal |
| Period | 06/15/15 → 06/19/15 |
Funding
The authors would like to thank G. W. Garner, T. M. Lowe, K. M. Cooley, H. Longmire, T. Jordan and D. Leonard for assistance with the experimental work. Plating of Pt was conducted at Tennessee Tech. University by Prof. Y. Zhang. B. Hazel and B. Nagaraj at General Electric Aircraft Engines provided the N5 and N515 substrate materials and coated the specimens with EB-PVD YSZ and Stonybrook Univ. applied the HVOF and APS coatings. The X4 substrates were provided by K. Murphy at Alcoa Howmet, the 1483 substrates by A. Kulkarni at Siemens and the 247 substrates by Capstone Turbine Corp. P. F. Tortorelli provided helpful comments on the manuscript. This research was sponsored by the U.S. Department of Energy, Office of Coal and Power R&D, Office of Fossil Energy, (R. Dennis program manager). This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-publicaccess-plan).