Session: 12-12-01: Gas Turbine Heat Transfer and heat exchanger

Paper Number: 165715

Experimental Study on the Impact of Nanoparticle Seeding on Blowoff Limits and Flame Stability of Gaseous Fuel Blends in a Low Swirl Burner 

As global energy demands rise, the need for advanced combustion technologies that support sustainable fuels while minimizing emissions has become increasingly critical. This study explores the influence of nanoparticle seeding on flame stability and flammability limits in a 1-inch Low Swirl Burner (LSB) designed by Robert Cheng at Lawrence Berkeley National Laboratory, with a swirl number of 0.5. Acetylene black nanoparticles were introduced at a controlled seeding rate of 0.01 mg/s into pure methane, pure ammonia, and their hydrogen-enriched blends. To achieve precise and uniform particle injection, a custom-built seeder was employed, consisting of a rotating arm to prevent particle agglomeration and a vibrator operating at 153 Hz to ensure a steady flow through a narrow nozzle. The seeder was carefully tuned to maintain minimal aerodynamic disturbances while ensuring consistent nanoparticle dispersion in the fuel-air mixture. The experimental setup included a premixer to ensure uniform fuel-air distribution before entering the burner. To analyze the impact of nanoparticle seeding, high-speed videography and planar laser-induced fluorescence (PLIF) imaging were utilized to capture flame dynamics, track the flame front, and quantify radius of curvature of the local flame surface. In addition, the flame surface density (FSD) has been calculated to further strengthen the arguments presented in the paper. 300 OH-PLIF images have been captured and utilized for each blend while the high speed camera had a 400 frames per second (FPS) speed to capture the burning process. ImageJ and MATLAB have been used as the analyzing platforms. The results reveal that nanoparticle seeding significantly enhances flame stability in pure methane and ammonia flames, with flammability limit improvements of 6.67% and 2.53%, respectively. Furthermore, acetylene black seeding reduced flame base fluctuation by 20% in methane flames, highlighting its stabilizing effect. These enhancements are attributed to the high thermal conductivity and surface area of acetylene black, which facilitate heat redistribution and modify reaction kinetics. However, in hydrogen-enriched fuel blends, the dominant effects of hydrogen’s high diffusivity and reactivity overshadowed the influence of nanoparticles, resulting in minimal changes in flammability limits and stability. While a blend of 80% methane and 20% hydrogen exhibited a 21.4% reduction in flame base fluctuations due to nanoparticle seeding, other blends with higher hydrogen content showed negligible improvements. These findings suggest that nanoparticle seeding can partially replicate the stabilizing effects of hydrogen in methane and ammonia flames but is less effective in hydrogen-dominated blends. The insights gained contribute to the development of cleaner and more efficient combustion strategies for sustainable fuel applications.

Presenting Author: Rahat Mollick The University of Iowa

Presenting Author Biography: I am presently a third-year PhD student in the Department of Mechanical Engineering, advancing my academic journey following the completion of my BSc in mechanical engineering from Bangladesh University of Engineering and Technology (BUET). Before embarking on my PhD at the University of Iowa, I held a position as an officer in the project management division at Renata Limited. I also gained valuable industry experience through a month-long attachment with LafargeHolcim Bangladesh Limited. My professional focus centers on research and development, project management, and teaching. I specialize in combustion research, HVAC systems design and installation, and fundamental industrial maintenance.

Besides working as the lab safety manager, my responsibilities include combustion research, nanofuel settling studies, and mentoring and collaborating with our undergraduate research assistants.

My future goal is to establish myself as a skilled and insightful experimental researcher and to have meaningful contribution in my field of study.

Authors:

Rahat Mollick The University of Iowa
Ma Chenrui Institute of Process Engineering, Chinese Academy of Sciences
Fujing Wen Institute of Process Engineering, Chinese Academy of Sciences
Yun Huang Institute of Process Engineering, Chinese Academy of Sciences
Jianan Zhang Massachusetts Institute of Technology
Hongtao Ding University of Iowa
Albert Ratner University of Iowa