Session: Student Poster Competition

Submission Number: 186816

Experimental Investigation of a Fuel-Staged Jet-Stabilized Burner Operating With 100% Hydrogen 

Within the EU Marie Curie project ICHAruS (Project 10112031), a fuel-staged, jet-stabilized burner for 100% hydrogen combustion was designed and 3-D printed. The burner features a two-stage configuration consisting of a primary and a secondary stage. Fuel is supplied to different sections of the burner, allowing independent control of the fuel flow to each stage. A Fuel Staging Ratio (FSR) was defined as the percentage of fuel flowing through the secondary stage relative to the total fuel supplied to the burner.

The burner was experimentally investigated under various operating conditions. First, the fuel staging ratio was varied at constant equivalence ratio. Subsequently, the fuel staging ratio was fixed while the equivalence ratio was varied, extending the investigation down to the lean blow-out (LBO) limit. The LBO limit was analyzed to assess the influence of the secondary stage on the overall burner stability and load flexibility.

OH* chemiluminescence was performed to characterize flame shape using a CCD camera (LaVision Imager Intense) coupled with an image relay optics device (IRO), a UV objective and bandpass filter. Exhaust gas measurements were using a commercial gas analyzer (MGAprime from MRU GmbH).

The introduction of the secondary stage is observed to influence the flame structure. Two distinct reaction zones associated with the two stages are clearly observed. Furthermore, the secondary stage affects the lift-off height of the reaction zone related to the primary stage, reducing it.

The results show that the presence of the secondary stage reduces NOx emissions at higher equivalence ratios, whereas at lower equivalence ratios the primary stage alone exhibits better performance. For high fuel staging ratios, i.e., when most of the fuel is supplied to the secondary stage, the LBO limit is extended compared to operation with only the primary stage at the same thermal power.

These findings highlight the role of the secondary stage in enhancing hydrogen mixing and influencing the overall combustion behavior of the burner. More sophisticated optical measurements including PIV and OH PLIF are under way to better understand the potential changes in stabilization mechanisms when different FSR is applied.

Presenting Author: Elisabetta Leoncino German Aerospace Center (DLR)

Presenting Author Biography: Elisabetta Leoncino, born on 27/07/2000 in Florence, Italy.
Mechanical engineer specialized in turbomachinery for both aeronautical and heavy-duty applications.
Completed both Bachelor's and Master's degrees in Mechanical Engineering from the University of Florence, within the Department of Industrial Engineering (DIEF).
During the Master's program, focused on aerodynamic design and combustion processes applied to turbomachinery.
The Master’s thesis, in collaboration with the company Baker Hughes, was centred on the development of a three-dimensional numerical model of centrifugal compressor cavities for aeromechanical assessment.
Currently, PhD student at the German Aerospace Center (DLR) in Stuttgart, working within the MSCA Doctoral Network (Marie Skłodowska-Curie Actions Doctoral Network) , inside ICHAruS project (Investigation and Control of Hydrogen Flames Across the Scales).
The topic of the PhD is: Experimental study of fuel staging in jet-stabilized hydrogen flames.

Authors:

Elisabetta Leoncino German Aerospace Center (DLR)
Zhiyao Yin German Aerospace Center (DLR)
Andreas Huber German Aerospace Center (DLR)