Combustion of stratified hydrogen-air mixtures in the 10.7 m3 combustion test facility cylinder

Whitehouse, D. R.; Greig, D.; Koroll, G.W.

doi:10.1016/s0029-5493(96)01261-7

Cited by 26 publications

(8 citation statements)

References 2 publications

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“…A modification of flame propagation speed has also been observed by Karim and Panlilio [5], who noted an increase of 70% for a flame propagating in a vertical open tube filled by a stratified methane/air mixture. The conclusions of Whitehouse et al [6] are the same for a hydrogen/air flame. In a closed tube, they also noted an important increase in the maximum overpressure.…”

Section: Introductionmentioning

confidence: 56%

Highlights of the flame acceleration in a confined nonuniform H₂/O₂/N₂ mixture

Daubech¹,

Sochet²,

Proust³

2010

Process Safety Progress

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Gaseous explosion models generally assume the gas mixture to be uniform. However, in a real explosion, the vapor cloud may not be homogeneous, and repartitioning of the reactivity inside the cloud can be subject to wide spatial variations. In this work, experimental tests were run to study the flame propagation and acceleration in nonuniform mixtures. Experiments were performed in a long vertical confined tube with a square cross section, composed of four equal sections. A gate valve separated the tube into two parts, and the composition of the gases was different on each side of the valve. The opening of the valve permitted the mixing of gases by molecular diffusion. For nonuniform mixtures, a mode of propagation identical to that seen in uniform mixtures was observed; however, a third phase of propagation was found, in which the flame velocity increased strongly. This increase occurred with higher hydrogen concentration in an upward‐propagating flame. A concentration gradient can appreciably modify the trajectory and acceleration of a flame. Here, however, the incidence of pressure effects remained modest, since the combustion was confined and the final pressure depended mainly on the quantity of reactants available. © 2009 American Institute of Chemical Engineers Process Saf Prog, 2009.

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Section: Introductionmentioning

confidence: 56%

Highlights of the flame acceleration in a confined nonuniform H₂/O₂/N₂ mixture

Daubech¹,

Sochet²,

Proust³

2010

Process Safety Progress

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“…The single-step mechanism was further validated by CTF experiment (Whitehouse et al, 1996). Figure 6A shows the predicted results for hydrogen concentration of 12.8% at 0.1 MPa, initially 298.15 K. Figure 6B results show that the global mechanism predicts the published experimental results reasonably well.…”

Section: Model Validationmentioning

confidence: 70%

“…Using the calculated kinetic parameters, the model at lower hydrogen concentration (C hydrogen < 20%) was both implemented in our experiments carried out in a closed container and combustion test facility (CTF) facilities (Whitehouse et al, 1996) and validated by comparing flame front position of hydrogen-air mixtures. In addition, the model at higher hydrogen concentration (C hydrogen > 20%) was compared with the results simulated by detailed mechanism.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Hydrogen Combustion: Global Reaction Model and Validation

Zhang

Liu

2017

Front. Energy Res.

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Due to the complexity of modeling the combustion process in nuclear power plants, the global mechanisms are preferred for numerical simulation. To quickly perform the highly resolved simulations with limited processing resources of large-scale hydrogen combustion, a method based on thermal theory was developed to obtain kinetic parameters of global reaction mechanism of hydrogen-air combustion in a wide range. The calculated kinetic parameters at lower hydrogen concentration (C hydrogen < 20%) were validated against the results obtained from experimental measurements in a container and combustion test facility. In addition, the numerical data by the global mechanism (C hydrogen > 20%) were compared with the results by detailed mechanism. Good agreement between the model prediction and the experimental data was achieved, and the comparison between simulation results by the detailed mechanism and the global reaction mechanism show that the present calculated global mechanism has excellent predictable capabilities for a wide range of hydrogen-air mixtures.

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“…If considerable hydrogen stratification exists, local high hydrogen concentrations could become a concern. Deflagrations of stratified hydrogen-air mixtures were studied by Whitehouse et al [3] in a 10 m 3 cylindrical vessel and in an international collaboration project [4] in a 60 m 3 THAI (thermalhydraulic, hydrogen, aerosols, and iodine) vessel. Recently, Rudy et al [5] studied deflagration and detonation in a large-scale rectangular channel with a stratified hydrogen-air mixture in a partially unconfined flat layer and determined critical conditions for deflagration-to-detonation transition in nonuniform hydrogen-air mixtures.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study of Combustion Characteristics of Isolated Pockets of Hydrogen-Air Mixtures

et al. 2016

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This paper examines the dynamics of unconfined hydrogen–air flames and the criterion for flame propagation between neighbouring pockets of reactive gas separated by air using the soap bubble technique. The combustion events were visualized using high-speed schlieren or large-scale shadowgraph systems. It was revealed that for sufficiently lean hydrogen–air mixtures characterized by low flame speeds, buoyancy effects become important at small scales. The critical radius of hemispherical flame that will rise due to buoyancy is highly sensitive to the hydrogen concentration. The test results demonstrate that for transition of a flame between neighbouring pockets, the separation distance between the bubbles is mainly determined by the expansion ratio for near stoichiometric mixture, but it becomes much smaller for leaner mixtures because the flame kernel rises due to buoyant effects before the flame can reach the second bubble, thus the separation distance is no longer governed by the expansion ratio.

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Combustion of stratified hydrogen-air mixtures in the 10.7 m3 combustion test facility cylinder

Cited by 26 publications

References 2 publications

Highlights of the flame acceleration in a confined nonuniform H₂/O₂/N₂ mixture

Highlights of the flame acceleration in a confined nonuniform H₂/O₂/N₂ mixture

Numerical Simulation of Hydrogen Combustion: Global Reaction Model and Validation

Experimental Study of Combustion Characteristics of Isolated Pockets of Hydrogen-Air Mixtures

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Combustion of stratified hydrogen-air mixtures in the 10.7 m3 combustion test facility cylinder

Cited by 26 publications

References 2 publications

Highlights of the flame acceleration in a confined nonuniform H2/O2/N2 mixture

Highlights of the flame acceleration in a confined nonuniform H2/O2/N2 mixture

Numerical Simulation of Hydrogen Combustion: Global Reaction Model and Validation

Experimental Study of Combustion Characteristics of Isolated Pockets of Hydrogen-Air Mixtures

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Highlights of the flame acceleration in a confined nonuniform H₂/O₂/N₂ mixture

Highlights of the flame acceleration in a confined nonuniform H₂/O₂/N₂ mixture