Comparison of flame response characteristics between Non‐premixed and premixed flames under acoustic excitation

Ahn, Myunggeun; Kim, Taesung; Yoon, Youngbin

doi:10.1016/j.expthermflusci.2022.110707

Cited by 6 publications

(2 citation statements)

References 48 publications

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“…Compared to typical FTFs of other non-premixed flames [14,41], the FTF gain curves under different operating conditions in this study also exhibit a distinct bimodal shape. Moreover, the behavior of the two peak values varies with changes in the equivalence ratio.…”

Section: Flame Response Analysismentioning

confidence: 59%

Experimental Study on Flame Response Characteristics of a Non-Premixed Swirl Model Combustor

Yang,

Liu,

Zhang

et al. 2023

Energies

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Non-premixed swirl combustion has been widely used in pieces of industrial combustion equipment such as industrial boilers, furnaces, and certain specific gas turbine combustors. In recent years, the combustion instability of non-premixed swirl flames has begun receiving attention, yet there is still a lack of related research in academia. Therefore, in this study, we conducted experimental research on a swirl stabilized gas flame model combustor and studied the heat release response characteristics of the swirl combustor through the flame transfer function. Firstly, the flame transfer function (FTF) was measured under different inlet velocities and equivalence ratios, and the experimental results showed that the FTF gain curve of the non-premixed swirl flame exhibited a significant “bimodal” shape, with the gain peaks located around 230 Hz and 330 Hz, respectively. Secondly, two oscillation modes of the flame near the two gain peaks were identified (the acoustic induced vortex mode Mv and the thermoacoustic oscillation mode Ma), which have not been reported in previous studies on swirl non-premixed flames. In addition, we comprehensively analyzed the flame pulsation characteristics under the two oscillation modes. Finally, the coupling degrees between velocity fluctuations, fuel pressure fluctuations, and heat release fluctuations were analyzed using the Rayleigh Index (RI), and it was found that in the acoustic-induced vortex mode, a complete feedback loop was not formed between the combustor and the fuel pipeline, which was the main reason for the significant difference in the pressure fluctuation amplitude near 230 Hz and 330 Hz.

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Section: Flame Response Analysismentioning

confidence: 59%

Experimental Study on Flame Response Characteristics of a Non-Premixed Swirl Model Combustor

Yang,

Liu,

Zhang

et al. 2023

Energies

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“…W is the parameter characterizing the swirl intensity in the flow [1,[7][8][9][10][11]; N s is the number of mass and heat sources; and index m denotes the mean value [12][13][14][15]. Equations are considered to describe the boundaries of nonstationary processes in the gas turbine unit combustion chamber, including the start and stop of the flame:…”

Section: Methodsmentioning

confidence: 99%

Analysis of the Exothermic Reaction of Flame Ignition in the Combustion Chamber of a Gas Turbine Unit

Maspanov,

Bogov,

Martynenko

et al. 2023

Energies

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This article analyses the exothermic reaction of flame ignition in the combustion chamber of a gas turbine unit, which is characteristic of combustion chambers operating on traditional hydrocarbon fuels. The combustion of gases as an explosive process in confined and semi-enclosed areas remains a poorly understood section of thermal physics. Without a detailed review of the physical and chemical processes taking place in the combustion chamber, it cannot be said whether the gas turbine unit will run sustainably. It is also important to know what combustion modes are in principle possible after a loss of stability in the combustion chamber in order to take action against this in advance. To describe flame ignition and quenching in the flow of the fuel–air mixture through a combustion chamber, a system of differential conservation equations of energy and reactive species supplemented with the equation of state is used. Nonstationary combustion processes in gas-turbine engines were studied, and flame ignition and blow-off were determined by the heat balance and by the continuity of chemical processes. Calculation methodologies for various operating modes of the combustion chamber of a gas turbine unit are developed and realized. The results of the calculations that were carried out are presented with graphical interpretation and with their analysis provided in sufficient detail. Based on this analysis, recommendations are then provided. From the graphs, it can be observed that the combustion chamber of a gas turbine unit reaches its maximum limit of stable operation at the optimum value of the reduced flow velocity in the openings of the air supply to the combustion and the mixing zones of the flame tube (λOC)opt = 0.22 when the fuel–air mixture is at maximum depletion, ensuring that combustion does not stop and flame failure does not occur. The topic of this article relates to the intensification of hydrocarbon fuel combustion and the technological improvement of combustion chambers in gas turbine units. This topic is of exceptional importance and relevance, emphasizing its significance. The purpose of this work is to develop and implement a methodology for calculating various modes of operation of the combustion chamber of a gas turbine unit.

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Study on the acoustic disturbance characteristics of the spray flame

Wei,

Fang,

Zhou

2024

Thermal Science and Engineering Progress

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Comparison of flame response characteristics between Non‐premixed and premixed flames under acoustic excitation

Cited by 6 publications

References 48 publications

Experimental Study on Flame Response Characteristics of a Non-Premixed Swirl Model Combustor

Experimental Study on Flame Response Characteristics of a Non-Premixed Swirl Model Combustor

Analysis of the Exothermic Reaction of Flame Ignition in the Combustion Chamber of a Gas Turbine Unit

Study on the acoustic disturbance characteristics of the spray flame

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