자발광 계측을 이용한 모형 가스터빈 연소기의 연소불안정 화염구조 특성 = Combustion Instability Flame Structure Characteristics in Model Gas Turbine using the Chemiluminescence Measurement

다국어 초록 (Multilingual Abstract)

In nowadays the gas turbine which working lean condition is easy to make combustion instability phenomenon. To eliminate the onset of these instabilities and develop effective approaches for control, the mechanisms responsible for their occurrence must be understood. Flame recirculation zone is very important, as it can modulate fuel flow rate and may be the source of instability and its flame structure has a major impact on heat release and flame stabilization. In this study, we conducted experiments under various operating conditions with a model gas turbine combustor to examine the relation of combustion instability and flame structure by OH chemiluminescence image. The swirling CH₄/air flame was investigated with overall equivalence ratio of 1.2 to lean blowout limit and dump plane velocity 30∼70 ㎧. Phase locking analysis was performed to identify structural changes at each phase of reference dynamic pressure sensor at instability conditions. At instability condition, frame root size varies a lot compared to stable condition which is because of air, fuel mixture flow rate changes due to combustor pressure modulation. After this structural change, local extinction and re-ignition occur and it can make feedback loop for combustion instability. This analysis suggests that pressure fluctuation of combustion causes deformation of flame structure and variation of flame has the strong effect on the combustion instability.

목차 (Table of Contents)

• ABSTRACT
• 1. 서론
• 2. 실험 방법
• 3. 결과 및 검토
• 4. 결론
• 후기
• 참고문헌