Abstract
The development phases of an hydrogen fueled combustor for industrial gas turbine are presented in this paper, from the conceptual burner design definition to the verification phase in realistic environment.
The development strategy has been conceived to properly balance the market needs and the effort required to achieve them. The hydrogen combustion technology is mainly focused on flashback free burners and gas fuel injectors development, representing a significant fuel flexibility enhancement of the NovaLT gas turbines family.
The readiness of the currently available technology in dealing with hydrogen was verified in a dedicated testing session, in a full scale annular combustor rig. Stable flame windows were identified for different operating conditions, and characterized in terms of pollutant emissions, pressure pulsations and system component temperatures.
As matter of this work, a bunch of alternative burner solutions have been designed with the aim of reducing the NOx emissions while maintaining adequate limits to either blowout, flashback or thermoacoustic instabilities. To further mitigate the risk of high NOx emissions, the abatement though water injection has been investigated as well. An atmospheric reduced scale rig has been used to characterize the different viable burner solutions, ensuring fast and somehow iterative design changes, and arranged to mimic the main features of a industrial sized gas turbine combustor, namely the combustion air inlet temperature, the hot gases residence times and the equivalence ratio.
The results clearly indicate a viable candidate to be assessed in the more realistic environment represented by the full-annular rig. The main outcomes of such a test campaign are also reported in this paper, with focus on both the NOx emissions and the operability related aspects. Flashback and flame holding resistance tests have been thus performed, demonstrating that such a solution is technologically ready for the next verification step in a real engine.
The results, while indicating a design development paths for the investigated solutions, provide an exhaustive data set, useful to either the models validation or the identification of the developments needed for future detailed investigations.
