Measurement and scaling of turbulent burning velocity of ammonia/methane/air propagating spherical flames at elevated pressure

Dai, Hao; Wang, Jinhua; Cai, Xiao; Su, Shouguo; Zhao, Haoran; Huang, Zuohua

doi:10.1016/j.combustflame.2022.112183

Cited by 40 publications

(5 citation statements)

References 57 publications

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“…Thus, the lifted flame with very low values of H L exist, and the abrupt increase in H L occurs as Re fuel further increases. Meanwhile, decrease in burning intensity with increasing x a,f , which suppresses the flame stabilization for the sustained lifted-flames, and the reduced turbulent burning velocity of the NH 3 -added flames 50 affect the abrupt increase in H L , resulting in no abrupt increase for x a,f = 0.4 condition. It should be noted that data points for the sustained lifted-flames in Figures 2 and 4 correspond to the injection conditions after an abrupt increase in H L occurs.…”

Section: Resultsmentioning

confidence: 99%

Combustion Characteristics for the Stabilization of Nonpremixed Methane-Ammonia/Air Coflow Flames through Their Visualization

Kim,

Ku,

Kwon

2024

Energy Fuels

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In order to confirm the possible use of methane (CH 4 )ammonia (NH 3 ) blends as a low carbon fuel, the fundamental combustion characteristics for the stabilization of nonpremixed CH 4 − NH 3 /air flames using the coflow jet flame configuration are experimentally studied, observing the flame behaviors by the direct imaging, shadow-graph, and OH radical visualization systems. Two types of flames, attached and lifted flames, are observed, and extinction (blowout) occurs as the injection velocity of fuel u fuel increases. The occurrence of blowout for pure CH 4 /air flames depends on u fuel regardless of the injection velocity of coflow air u coflow , while it considerably depends on u coflow for CH 4 −NH 3 /air flames. The OH radical visualization reveals that NH 3 addition affects the overall reaction intensity and mechanism but does not reduce the average reaction region near the injector lip. Also, the addition of NH 3 reduces the formation of polycyclic aromatic hydrocarbons (PAHs) as a soot precursor. Direct images confirm the effects of NH 3 addition, u fuel , and u coflow on the flame length, and the liftoff height. The measured NO x emissions exhibit that the fuel NO x from NH 3 is dominant and the NO x emissions are considerably affected by the flame intensity and fluctuation.

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Section: Resultsmentioning

confidence: 99%

Combustion Characteristics for the Stabilization of Nonpremixed Methane-Ammonia/Air Coflow Flames through Their Visualization

Kim,

Ku,

Kwon

2024

Energy Fuels

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“…Lhuillier et al 80 performed an experiment under engine-relevant conditions with a mixture temperature of 445 K and a mixture pressure of 0.54 MPa for NH 3 -H 2 . Dai et al 81 and Wang et al 82 reported turbulent burning velocities of NH 3 -H 2 -air, respectively, at elevated pressure conditions and proposed empirical correlations for turbulent burning velocity. Wang et al 82 also reported NO emissions from the experiment and showed that NO concentration was independent of the turbulence intensity when the residence time was long.…”

Section: Turbulent Combustionmentioning

confidence: 99%

Mini Review of Ammonia for Power and Propulsion: Advances and Perspectives

Guiberti,

Pezzella,

Hayakawa

et al. 2023

Energy Fuels

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Ammonia is a molecule that has been essential to human activities for centuries. It is widely used as a feedstock for fertilizers, industrial chemicals, and emissions after-treatment systems. The properties of ammonia have led to its interest as a carrier for hydrogen in energy applications. The combustion of ammonia for power and propulsion offers direct applications of this molecule in energy and transportation applications. However, there are significant challenges related to ammonia combustion, including low flammability and potentially high emissions. Blending of ammonia with hydrogen or hydrocarbons offers opportunities to improve combustibility. This mini review discusses challenges related to ammonia combustion and current state-of-the-art approaches to overcoming these challenges with research into chemical kinetics, laminar and turbulent flames, and engine and turbine systems. This paper seeks to introduce and summarize recent results on ammonia combustion by highlighting pertinent aspects of this rich and rapidly increasing body of information.

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“…Nonlinear stretch behavior contributed up to 2% for lean mixtures, with a more pronounced effect at higher φ (equivalence ratio). In this study, the total uncertainties, calculated using the approach employed by Dai et al [47], were determined to range between 1.01 and 4.5 cm/s.…”

Section: Methanementioning

confidence: 99%

Experimental Study on the Effect of Hydrogen Addition on the Laminar Burning Velocity of Methane/Ammonia–Air Flames

et al. 2023

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Variations in methane–ammonia blends with hydrogen enrichment can modify premixed flame behavior and play a crucial role in achieving ultra-low carbon emissions and sustainable energy consumption. Current combustion units may co-fire ammonia/methane/hydrogen, necessitating further investigation into flame characteristics to understand the behavior of multi-component fuels. This research aims to explore the potential of replacing natural gas with ammonia while making only minor adjustments to equipment and processes. The laminar burning velocity (LBV) of binary blends, such as ammonia–methane, ammonia–hydrogen, and hydrogen–methane–air mixtures, was investigated at an equivalence ratio of 0.8–1.2, within a constant volume combustion chamber at a pressure of 0.1 MPa and temperature of 298 K. Additionally, tertiary fuels were examined with varying hydrogen blending ratios ranging from 0% to 40%. The results show that the laminar burning velocity (LBV) increases as the hydrogen fraction increases for all mixtures, while methane increases the LBV during blending with ammonia. Hydrogen-ammonia blends are the most effective mixture for increasing LBV non-linearly. Enhancement parameters demonstrate the effect of ternary fuel, which behaves similarly to equivalent methane in terms of adiabatic flame temperature and LBV achieved at 40% hydrogen. Experimental data for neat and binary mixtures were validated by different kinetics models, which also showed good consistency. The ternary fuel mixtures were also validated with these models. The Li model may qualitatively predict well for ammonia-dominated fuel. The Shrestha model may overestimate results on the rich side due to the incomplete N2Hisub-mechanism, while lean and stoichiometric conditions have better predictions. The Okafor model is always overestimated.

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Measurement and scaling of turbulent burning velocity of ammonia/methane/air propagating spherical flames at elevated pressure

Cited by 40 publications

References 57 publications

Combustion Characteristics for the Stabilization of Nonpremixed Methane-Ammonia/Air Coflow Flames through Their Visualization

Combustion Characteristics for the Stabilization of Nonpremixed Methane-Ammonia/Air Coflow Flames through Their Visualization

Mini Review of Ammonia for Power and Propulsion: Advances and Perspectives

Experimental Study on the Effect of Hydrogen Addition on the Laminar Burning Velocity of Methane/Ammonia–Air Flames

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