• Research Article

    Recent Research Trends in Ammonia Gas Turbine Combustion Technology

    암모니아 가스터빈 연소기술의 연구 동향

    Ukhwa Jin, Jun Lee, Kyu Tae Kim

    진욱화, 이준, 김규태

    This paper focuses on the recent development of ammonia gas turbine combustion technologies. Gas turbine technology exhibits significant potential to broaden its … + READ MORE
    This paper focuses on the recent development of ammonia gas turbine combustion technologies. Gas turbine technology exhibits significant potential to broaden its contribution to future power generation, driven by inherent characteristics such as fuel flexibility and rapid load-following capabilities. Ammonia is regarded as an attractive carbon-free fuel owing to its exceptional transport and storage capabilities. However, there are several challenges associated with utilizing ammonia as a fuel in gas turbine combustion systems. Hence, this paper discusses the fundamentals of ammonia-based combustion while summarizing recent efforts concerning its reactivity enhancement methods and strategies for mitigating NO emissions. - COLLAPSE
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    31 March 2024

  • Research Article

    Trends in Research and Development of Combustor Applying the Principle of Micromix

    Micromix 원리를 적용한 연소기 연구개발 동향

    Seungmin Kim, Hyoungjjn Lee

    김승민, 이형진

    Energy demand and environmental pollution control are challenging issues in the field of gas turbine applications, with the aim of achieving zero … + READ MORE
    Energy demand and environmental pollution control are challenging issues in the field of gas turbine applications, with the aim of achieving zero carbon and low NOx emissions from combustion gases. In this context, hydrogen fuel is anticipated as a future energy source capable of replacing carbon-based fuels. However, hydrogen presents technological challenges related to safety issues such as flashback and autoignition. Additionally, there is a need to address issues of increased NOx emissions due to high adiabatic flame temperatures. To overcome these challenges, research is underway to develop combustion systems, particularly in the form of micromix or micro-mixer configurations. The micromix combustion system, which uses small nozzles and flames, has been evaluated as one of the most suitable combustors for hydrogen and hydrogen-blended fuels by preventing flashback and reducing NOx emissions. This paper introduces the effect of various geometric factors, such as fuel injection shapes, fuel inlet and nozzle numbers, and internal configurations, on the optimal design and combustion instability of micromix combustion systems. The characteristics of combustion systems developed by research institutions and companies are also analyzed. The paper concludes with a discussion on the applicability of micromix combustion systems to hydrogen combustion applications. - COLLAPSE
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    31 March 2024

  • Research Article

    Diagnosis of Combustion Instability Using Waveform Pattern of Dynamic Pressure Signal

    동압 신호의 파형-패턴 분석을 통한 연소 진동 진단

    Seungkyu Choi, Daesik Kim

    최승규, 김대식

    This study introduces a new concept that can evaluate the combustion status from the waveform patterns of the dynamic pressure signal, and … + READ MORE
    This study introduces a new concept that can evaluate the combustion status from the waveform patterns of the dynamic pressure signal, and an initial investigation result on the possibility of combustion instability monitoring, by classifying the waveform of time-series discrete dynamic pressure data, measured in a gas turbine combustor. Based on variations in amplitude among four continuously adjacent data points of dynamic pressure, there are 24 waveform patterns that can be classified. These patterns can be further streamlined to derive three representative diagnostic factors. The representative factors tended to converge to the specific values when combustion instability occurred. Furthermore, distinct characteristic value distributions were observed in stable and transitional states, respectively. These results implied that the waveform pattern, newly defined in this study, can be effectively used as a combustion instability diagnostic tool. - COLLAPSE
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    31 March 2024

  • Research Article

    Evaluation of the Improvement of FGR Circulation Gas Deflection for the Stabilization of NOx Generation in Mixed Gas Boilers

    혼합 가스 보일러의 NOx 발생 안정화를 위한 FGR 순환 가스 편류 현상 개선 방안 실증 평가

    Meong Seong Park

    박명성

    The steel industry makes the most of it’s incidental COG (Coke oven gas) and BFG (Blast furnace gas) as fuel and is … + READ MORE
    The steel industry makes the most of it’s incidental COG (Coke oven gas) and BFG (Blast furnace gas) as fuel and is striving to achieve it’s greenhouse gas reduction goals in line with the era of national carbon neutrality. NOx generated during boiler combustion is reduced by using the FGR method that circulates the combustion gas. However, there is often a problem that the combustion air and the combustion gas are not well mixed. In this paper, we tried to achieve efficiency improvement and stable NOx reduction by studying the cause of the FGR efficiency reduction and improving the problems. When mixing FGR combustion gas, it was not evenly sprayed into the burner due to deflection. As a result, the temperature of some flames increased and thermal NOx increased. In order to improve the mixing of combustion gas and combustion air, the gas pressure deviation was increased by 100∼200 mmAq or more and converted to an injection type, and a porous plate was installed to disperse the combustion gas to improve mixing efficiency. The boiler flame formed a stable shape, and the NOx data also showed a reduction effect of 7 ppm and uniform data. - COLLAPSE
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    31 March 2024

  • Research Article

    Amplification of Combustion Instabilities in a Lean-premixed Axially-staged Combustor due to Frequency Synchronization

    희박 예혼합 다단 연소기에서의 주파수 동조에 의한 연소불안정 증폭

    Yongseok Choi, Gyeonghyun Han, Kyu Tae Kim

    최용석, 한경현, 김규태

    The self-excited dynamics of a lean-premixed axially-staged combustor, with respect to the characteristic acoustic frequency, were experimentally investigated by varying the hydrogen … + READ MORE
    The self-excited dynamics of a lean-premixed axially-staged combustor, with respect to the characteristic acoustic frequency, were experimentally investigated by varying the hydrogen mole fraction in the primary flame while maintaining the fuel composition of the secondary flame constant. It is observed that the dominant instability frequency transitions from lower to higher acoustic modes with varying hydrogen concentrations during single-flame combustion. We demonstrate that under axially-staged conditions, the more complex instabilities can be triggered and sustained by the combination of local heat release fluctuations generated from the primary flame and secondary transverse reacting jets. When the instability frequencies of the primary and secondary flames synchronize with each other, especially within the same acoustic mode, the amplitudes of pressure fluctuations are significantly amplified compared to those observed with single flame condition. - COLLAPSE
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    31 March 2024

  • Research Article

    Flame Characteristics and NO Emission Behaviors in (CH4+NH3)/air Counterflow Premixed Flames Having Downstream Interaction with Opposed NH3/air Premixed Flames

    암모니아/공기가 대향으로 분사되는 (메탄+암모니아)/공기 대향류 예혼합 화염에서 후류 상호 작용하의 화염 특성과 NO 배출 거동

    Huido Lee, Chun Sang Yoo, Jeong Park

    이희도, 유춘상, 박정

    Flame characteristics and NO emission behaviors are studied for (80% CH4+20% NH3)/air premixed counterflow flames having downstream interactions … + READ MORE
    Flame characteristics and NO emission behaviors are studied for (80% CH4+20% NH3)/air premixed counterflow flames having downstream interactions with NH3/air premixed flames, by varying strain rate and equivalence ratio. Extinction strain rates against equivalence ratio (ϕsec) in the secondary zone are numerically presented for the equivalence ratios (ϕpri) in the primary combustion zone ϕpri = 0.8 and 1.2 as representative cases. The flame structures are analyzed, and the concept of local equilibrium temperature and loss ratio are introduced to clarify the mechanisms of flame extinction. NO emission indices are presented for a specified ϕpri = 1.2 (a favorable mixture condition in ammonia-blended fuel) by varying ϕsec. NO related reaction paths are examined to explain the important paths in NO reduction. The results show that NO reduction is obtained via enhancing the paths of NH → NNH and NH → N2, though it should be confirmed by further future works because these cover only such case studies. The present study can mimic a two-stage swirl combustion with having a small separation distance between the primary and secondary combustion zones. Therefore, the present results can be utilized in a two-stage swirl combustion with having a small separation, where the primary and secondary premixed flames experience strong interactions. - COLLAPSE
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    31 March 2024
리스트형 보기썸네일형 보기
Journal Informaiton Journal of The Korean Society Combustion Journal of The Korean Society Combustion
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