Flame dynamics and stability of premixed methane/air in micro-planar quartz combustors

Cai, Tao; Tang, Aikun; Zhao, Dan; Zhou, Chen; Huang, Qiuhan

doi:10.1016/j.energy.2019.116767

Cited by 34 publications

(5 citation statements)

References 64 publications

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“…The intensified heat recirculation can enable the flame to propagate upstream and anchor near the combustor inlet. This finding was also confirmed in the previous study [47].…”

Section: Effect Of Conjugate Heat Transfersupporting

confidence: 92%

NO emission performance assessment on a perforated plate-implemented premixed ammonia-oxygen micro-combustion system

Cai

Becker

Cao

et al. 2021

Chemical Engineering Journal

Self Cite

101

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The present work examines the NO x emission characteristics of a premixed micro-combustion system with a perforated plate implemented. For this, a three-dimensional (3D) computational model involving a detailed chemical-kinetic mechanism for ammonia-oxygen combustion in the micro-combustor is developed. The model is first validated with the experimental measurements available in the literature before conducting comprehensive analyses. It is found that implementing a perforated plate in the micro-combustion system creates a flow recirculation zone downstream characterized by a low flame temperature and combustion speed. Meanwhile, the conjugate heat transfer between the combustion products and the inner combustor walls is shown to play a key role in the NO generation by relocating the flame in the axial direction and thus changing the chemical reaction rate. Furthermore, the preferential diffusion caused by the variation in the mass diffusivity of different species and the two-dimensionality flow is identified to vary significantly in comparison with the case in the absence of the perforated plate, especially in the vicinity of the recirculation zone. This diffusion effect results in the considerable drop in the N/O atomic ratio, primarily due to the reduction and increase of O 2 and H 2 O, together with less available N 2 , and consequently affecting the NO generation rate. This work confirms that the flow field, the conjugate heat transfer as well as the preferential diffusion effect could be regarded as the potential mechanisms leading to the NO x emission variation in the recirculation zones. Nomenclature 3Dthree-dimensional specific heat of species, CO carbon monoxide CO 2 carbon dioxide CH 4

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“…The intensified heat recirculation can enable the flame to propagate upstream and anchor near the combustor inlet. This finding was also confirmed in the previous study [47].…”

Section: Effect Of Conjugate Heat Transfersupporting

confidence: 92%

NO emission performance assessment on a perforated plate-implemented premixed ammonia-oxygen micro-combustion system

Cai

Becker

Cao

et al. 2021

Chemical Engineering Journal

Self Cite

101

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“…OH is an important intermediate combustion product, whose distribution can represent the shape of the flame and the intensity of chemical reactions. [ 44 ] The principal reaction formulas are as follows [ 45 ]

\left(\text{H}\right)_{2} &amp;#x00026;amp;amp;amp;amp;amp;amp;amp;plus; \left(\text{O}\right)_{2} = \text{OH} &amp;#x00026;amp;amp;amp;amp;amp;amp;amp;plus; \text{OH}

\left(\text{H}\right)_{2} &amp;#x00026;amp;amp;amp;amp;amp;amp;amp;plus; \text{OH} = \left(\text{H}\right)_{2} \text{O} &amp;#x00026;amp;amp;amp;amp;amp;amp;amp;plus; \text{H}

\left(\text{O}\right)_{2} &amp;#x00026;amp;amp;amp;amp;amp;amp;amp;plus; \text{H} = \text{OH} &amp;#x00026;amp;amp;amp;amp;amp;amp;amp;plus; \text{O}

…”

Section: Resultsmentioning

confidence: 99%

“…OH is an important intermediate combustion product, whose distribution can represent the shape of the flame and the intensity of chemical reactions. [44] The principal reaction formulas are as follows [45] www.advancedsciencenews.com…”

Section: Effect Of Shrouding Hydrogen Flow Ratementioning

confidence: 99%

Effects of Surrounding Hydrogen Injection Parameters on Coherent Jet Characteristics in Electric Arc Furnace Steelmaking Process

Yang,

Chen,

et al. 2024

steel research int.

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The application of coherent oxygen injection improves the smelting efficiency and product quality by promoting the homogenization and impurities removal effects in electric arc furnace (EAF) steelmaking process. CH4 is widely applied as surrounding gas in traditional coherent jets, which inescapability generates some greenhouse gases (GHG), and against the ambitious carbon reduction goal. Herein, H2 instead of CH4 as surrounding gas in coherent jet is introduced. Based on fluid and combustion mechanics, a computational fluid dynamics model with hydrogen–oxygen combustion is developed and validated to study coherent jet characteristics considering H2 flow and ambient temperature. The results indicate that the shrouding hydrogen nozzle has a significant impact on the potential core length of the coherent jet. Shrouding oxygen can solve the problem of excessive consumption of main oxygen by shrouding hydrogen. When the equivalent ratio between shrouding hydrogen and shrouding oxygen maintains 1, increasing the flow rates is highly beneficial for improving oxygen jet performance at tested conditions. The potential core length of the jet increases little with the ambient temperature in the range of 1100–1700 K. This research is expected to extend hydrogen application in EAF steelmaking process for GHG reduction.

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“…For an equivalence ratio of one (Φ = 1), a stable flame was observed with mixture velocity ranging from 0.2 to 1.2 m/s. Cai et al [19] numerically studied the flame dynamics and stability of a CH 4 -air mixture in a quartz planar micro-combustor, and it was observed that the flame was stabilized, with mixture inlet velocity ranging from 0.2 to 0.4 m/s for an equivalence ratio of one. Singh et al [20] investigated the effect of H 2 addition on the flame dynamics of premixed methane/air mixtures in a micro-tube of length 120 mm and diameter 2 mm.…”

Section: Introductionmentioning

confidence: 99%

Impact of H2 Blending of Methane on Micro-Diffusion Combustion in a Planar Micro-Combustor with Splitter

Sudarsanan,

Velamati,

Alquaity

et al. 2024

Energies

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An investigation into the non-premixed combustion characteristics of methane in a planar micro-combustor with a splitter was performed. The impact of blending methane with hydrogen on these characteristics was also analyzed. Additionally, the effects of inlet velocity and global equivalence ratio on flame location, flame temperature, combustion efficiency and outer wall temperature were studied for three different fuel compositions: pure methane (MH0), 60% methane with 40% hydrogen (MH40), and 40% methane with 60% hydrogen (MH60)). A heat recirculation analysis of the combustor wall was conducted to determine the amount of heat recirculated into the unburnt gas at various inlet velocities for all three fuel compositions. The results demonstrated that the stability limit of methane in terms of inlet velocity (1–2 m/s) and global equivalence ratio (1.0–1.2) was significantly enhanced to 1–3 m/s and 0.8–1.2, respectively, with the addition of hydrogen. At an inlet velocity of 2 m/s, the flame location of 3.6 mm for MH0 was significantly improved to 2.2 mm for MH60. Additionally, outer wall temperature exhibited a rise of 100 K for MH60 compared to MH0. Furthermore, from heat recirculation analysis, when the ratio of heat recirculated to heat loss exceeded unity, the flame started exhibiting the lift-off phenomenon for all the fuel compositions.

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Flame dynamics and stability of premixed methane/air in micro-planar quartz combustors

Cited by 34 publications

References 64 publications

NO emission performance assessment on a perforated plate-implemented premixed ammonia-oxygen micro-combustion system

NO emission performance assessment on a perforated plate-implemented premixed ammonia-oxygen micro-combustion system

Effects of Surrounding Hydrogen Injection Parameters on Coherent Jet Characteristics in Electric Arc Furnace Steelmaking Process

Impact of H2 Blending of Methane on Micro-Diffusion Combustion in a Planar Micro-Combustor with Splitter

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