Simulating novel gas turbine conditions for materials assessment: Cascade design and operation

Abstract

Integrated gasification combined cycles can incorporate pre-combustion carbon capture. High-H 2 syngas produces high H 2 O levels after combustion, potentially accelerating gas turbine component damage. Determining materials systems' suitability for this novel environment requires exposures in representative environments. Thus, an existing 0.7 MW burner rig was modified to generate the combustion environment and incorporate a cascade of 15 air-cooled turbine blades. Computational fluid dynamic calculations using blade dimensions and flow requirements supported the cascade design and determined blade placement within the gas flow. Trials of the modified unit have shown that a simulated combusted H 2 -rich syngas composition was generated at gas temperatures ≤1440°C. A 1000 h exposure has been carried out with thermal barrier coated blades to demonstrate the operation of the unit.

Materials challenges in hydrogen-fuelled gas turbines

“…Since the components exposed to the highest temperature will be coated with a TBC system, the stability of YSZ and the bond coat material at higher temperature and steam contents should be considered. There have been several studies to determine the durability of TBC and bond coats under various levels of water vapour content: Sumner et al [99] tested gas turbine blades in a simulated H 2 -rich syngas composition with 20 vol% H 2 O over 1000 h. The combustion temperature was up to 1440°C, but air cooling was used to limit the blade surface temperature to 950-1050°C. The blades were made of the Ni-based superalloy Rene 80 and coated with either a high velocity oxy fuel (HVOF) metallic coating (Sicoat ® 2464, NiCoCrReYAl) or different combinations of a thermal barrier coating (YSZ-based) and a bond coat.…”

“…Sumner et al [99] tested gas turbine blades in a simulated H 2 -rich syngas composition with 20 vol% H 2 O over 1000 h. The combustion temperature was up to 1440°C, but air cooling was used to limit the blade surface temperature to 950–1050°C. The blades were made of the Ni-based superalloy Rene 80 and coated with either a high velocity oxy fuel (HVOF) metallic coating (Sicoat ® 2464, NiCoCrReYAl) or different combinations of a thermal barrier coating (YSZ-based) and a bond coat.…”

Stacking faulted P phase in a grit-blasted Ni-based single-crystal superalloy after thermal exposure

“…The DD6 alloy is a second-generation nickel-based single-crystal superalloy containing 2 wt-% Re [4], with tensile and creep rupture properties comparable to CMSX-4 [5]. Practical application of the investment cast DD6 alloy usually includes surface repair by grit-blasting for assembling or ensuring acceptable substrate condition for thermal barrier coating adherence [6][7][8]. Owing to the induced residual stress generated by grit-blasting, surface recrystallisation or precipitation of topologically close-packed (TCP) phases would take place during high-temperature thermal exposure [9][10][11].…”

Health monitoring system for the 10 MW Supercritical Carbon Dioxide S-CO2 Gas Turbine Power Plant

“…Temperature limitations in either of these components may restrict operation in this model of 10 MW supercritical CO 2 gas turbine [100]. The maximum permissible turbine exit temperature is dependent on the materials used for the construction of the HTR for example, when using stainless steel the temperature should not be above 900 K [100,101].…”