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2026 Vol.31, Issue 2 Preview Page

Research Article

Effects of Dilution on NOx Emission Characteristics of Partially Premixed H2/CO Flame

부분 예혼합 H2/CO 화염에서 희석이 NOx 배출 특성에 미치는 영향

Jaeyo Oh14
,
Jisoo Yoon2
,
Jeongjin Kim2
,
Youngbin Yoon3†
,
Kyubok Ahn4†
오 재요14
,
윤 지수2
,
김 정진2
,
윤 영빈3†
,
안 규복4†
1Department of Aerospace Engineering, Republic of Korea Air Force Academy
2Agency for Defense Development
3Department of Aerospace Engineering, Seoul National University
4School of Mechanical Engineering, Chungbuk National University
1공군사관학교 항공우주공학과
2국방과학연구소
3서울대학교 항공우주공학과
4충북대학교 기계공학부
*Corresponding Author
30 June 2026. pp. 50-59
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Abstract

In this study, the effects of dilution on NOx emission characteristics from partially premixed H2/CO syngas flames were experimentally investigated using a model gas turbine combustor. The influence of diluent type (N2 and CO2) and dilution placement (fuel-side and air-side) was examined to identify the key factors governing NOx formation. The results showed that NOx formation was primarily governed by the thermal NOx mechanism, with flame temperature being the dominant factor. Dilution effectively reduced NOx emissions by lowering flame temperature; however, the reduction efficiency strongly depended on dilution placement. Under lean conditions, fuel-side dilution was more effective than air-side dilution due to greater interaction with the reaction zone. Furthermore, CO2 dilution resulted in lower NOx emissions than N2 dilution even at similar heat capacity conditions. This indicates that NOx emission characteristics are influenced not only by thermal effects but also by mixing behavior and the chemical properties of the diluent.

Keywords
Syngas
Partially premixed flame
NOx
Dilution
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Information
  • Publisher :The Korean Society of Combustion
  • Publisher(Ko) :한국연소학회
  • Journal Title :Journal of the Korean Society of Combustion
  • Journal Title(Ko) :한국연소학회지
  • Volume : 31
  • No :2
  • Pages :50-59
  • Received Date : 2026-05-07
  • Revised Date : 2026-06-15
  • Accepted Date : 2026-06-15
  • DOI :https://doi.org/10.15231/jksc.2026.31.2.050
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