Structure and Stability Characteristics of CH4/H2 Co-Firing Flames in a Multi-Nozzle Gas Turbine Combustor
다중 노즐 가스터빈 연소기에서 CH4/H2 혼소 화염의 구조 및 안정성 특성에 관한 연구
- 주제(키워드) 도움말 Hydrogen co-firing , Flashback , NOx emssions , CFD Analysis , Flame structrue
- 발행기관 국립강릉원주대학교 일반대학원
- 지도교수 도움말 최민성
- 발행년도 2025
- 학위수여년월 2026. 2
- 학위명 석사
- 학과 및 전공 도움말 일반대학원 자동차공학과
- 실제URI http://www.dcollection.net/handler/kangnung/000000012305
- UCI I804:42001-000000012305
- 본문언어 영어
초록/요약 도움말
This study investigates the combustion characteristics of methane-hydrogen co-firing in gas turbine combustors using 3-D CFD simulations and experimental validation. For the single-nozzle combustor, simulations were conducted under atmospheric pressure (1.3 barA) with hydrogen co-firing ratios of 0%, 30%, and 50%, and the results including NOX emissions and temperature fields showed strong agreement with experimental data provided by KIMM. The peak flame temperatures increased from 2250 K to 2452 K as hydrogen content rose, and NOX emissions exhibited a corresponding upward trend. The analysis was extended to a multi-nozzle combustor under practical gas turbine operating conditions with pressures ranging from 1.3 to 15 barA and hydrogen co-firing ratios of 0%, 30%, 50%, and 70%. The flame maintained an M-shaped structure under most conditions however, at specific operating points (e.g., 11 barA and 30% H2), a transition to a V-shaped flame occurred, causing flame attachment to the nozzle and indicating potential risks of flashback and hardware damage. Adjusting the pilot split ratio effectively restored the M-shaped flame, demonstrating its critical role in ensuring combustion stability at high pressures and high hydrogen co-firing ratios. Pressure increase enlarged the inner recirculation zone volume up to a sixfold increase for the ON nozzles between 1.5 and 15 barA while simultaneously reducing NOX emissions compared to atmospheric pressure due to limited high temperature (>2373 K) regions under the examined conditions. Overall, flame shape, and emissions, and identifies the pilot split ratio as a key operational parameter for maintaining stable and low emission combustion in hydrogen enriched gas turbines.
more목차 도움말
1. Introduction 1
1.1 Background 1
1.2 Previous studies 3
2. Research methodology 5
2.1 Numerical modeling 5
2.1.1 Governing equations 5
2.1.2 Turbulence model 6
2.1.3 Combustion model 8
2.1.4 Chemical mechanism 9
2.2 Single-nozzle combustor modeling and operating condition 10
2.2.1 Combustor modeling and mesh system 10
2.2.2 Single-nozzle mesh dependency 12
2.2.3 Computational operating and boundary conditions 14
2.3 Multi-nozzle combustor modeling and operating conditions 16
2.3.1 Combustor modeling and mesh system 16
2.3.2 Validation of numerical results with multi-nozzle combustor 19
2.3.3 Computational operating and boundary conditions 21
3. Results and discussion 24
3.1 Effect of co-firing ratio on the single-nozzle combustor 24
3.2 Effect of co-firing ratio on the multi-nozzle combustor 37
4. Conclusions 55
REFERENCES 56
