Shock-tube study of methane ignition under engine-relevant conditions: experiments and modeling

Huang, Jian; Hill, Philip G.; Bushe, W. Kendal; Munshi, S. R.

doi:10.1016/j.combustflame.2003.09.002

Cited by 156 publications

(87 citation statements)

References 44 publications

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“…It can be seen that with an increasing amount of oxygen the ignition delay time decreases. This is in agreement with other works, [7][8][9][10] which examine promotion and inhibiting effects of ignition. The comparison of both gases at the same excess air ratio (lϭ1.69 in Fig.…”

Section: Pfr With Detailed Chemistrysupporting

confidence: 93%

Theoretical Analysis on the Injection of H2, CO, CH4 Rich Gases into the Blast Furnace

et al. 2005

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The aim of this work is the determination of the combustion characteristics of two different fuel gases for their blast furnace utilization. The availability of gas from the coke production as well as from the basic oxygen furnace (BOF) process in an integrated metallurgical plant makes it possible to substitute reducing agents like oil. For a description of the varieties of the gases, coke oven gas (COG) and a mixture of COG and BOF gas, four independent modeling approaches were applied to cover all aspects. The different applied modeling approaches are the thermodynamic equilibrium, the plug flow reactor (PFR) model with detailed chemistry with or without, resp., consideration of the mixing time and computational fluid dynamics (CFD). This guarantees an improved understanding of the whole combustion process.The earlier ignition of the COG/BOF gas mixture in comparison to the COG can be ascribed to the higher excess air ratio, in spite of the better ignition propensity of COG. The higher net calorific value of the COG results in higher combustion temperatures, which implicates a higher thermal strain on the tuyere. In addition, greater amounts on CO and H 2 in the raceway result from the COG combustion.KEY WORDS: ironmaking; blast furnace; gas injection; modeling; combustion. time, it is possible to study the influence of different mixing lengths on the resulting temperature and species concentrations at the end of the tuyere.Computational Fluid Dynamics (CFD) allows a more detailed description of the predominant flow of gas injection. Because of the high resource demanding flow calculation, simplified models are used for the simulation of the reactions. The simplest assumption is the thermodynamic equilibrium again which is now based on the local composition. Basic Facts Plant LayoutThe layout of the blast furnace with the gas injection plant is shown in Fig. 1. In the mixing station, gas from the coke production (coke oven gas, COG) and gas from the basic oxygen furnace (BOF gas) are mixed if it is necessary. Then the process gas is conveyed via a screw compressor and a gas cooler to a bustle pipe, wherefrom it is directed to 17 tuyeres spread over the circumference of the blast furnace.The injection of the reducing gas is done by using two lances per tuyere, which is represented by the cases in this study (Fig. 2). The lances end 10 cm inside from the end of the tuyere. Input ParameterFor calculation, two gases with different compositions are used. These are the coke oven gas (COG) and a mixture of COG and BOF gas (COG/BOF). The different compositions of the two gases and their net calorific values as well as the predominant excess air ratios of the combustion process are listed in Table 2. The appointed boundary conditions valid for one tuyere can be seen in Table 3. Reaction MechanismsThe reaction mechanisms of the combustion are radical chain reactions. These chain reactions consist of starting reactions that build radicals, chain propagation reactions, chain branching reactions that increase the amount o...

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Section: Pfr With Detailed Chemistrysupporting

confidence: 93%

Theoretical Analysis on the Injection of H2, CO, CH4 Rich Gases into the Blast Furnace

et al. 2005

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“…These studies cover a wide range of conditions including low-to-high temperatures and pressures. Of these previous ignition delay time studies [26][27][28][29][30][31][32][33][34][35][36][37], only the work of Tang et al [37] included mixtures of CH 4 and DME. It covered dilute mixtures within a pressure range of 1 − 10 atm.…”

Section: Introductionmentioning

confidence: 99%

An ignition delay and kinetic modeling study of methane, dimethyl ether, and their mixtures at high pressures

Burke

Somers

O’Toole

et al. 2015

Combustion and Flame

381

279

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The development of accurate chemical kinetic models capable of predicting the combustion of methane and dimethyl ether in common combustion environments such as compression ignition engines and gas turbines is important as it provides valuable data and understanding of these fuels under conditions that are difficult and expensive to study in the real combustors. In this work, both experimental and chemical kinetic model-predicted ignition delay time data are provided covering a range of conditions relevant to gas turbine environments (T = 600 − 1600 K, p = 7 − 41 atm, φ = 0.3, 0.5, 1.0, and 2.0 in 'air' mixtures). The detailed chemical kinetic model (Mech 56.54) is capable of accurately predicting this wide range of data, and it is the first mechanism to incorporate high-level rate constant measurements and calculations where available for the reactions of DME. This mechanism is also the first to apply a pressure-dependent treatment to the low-temperature reactions of DME. It has been validated using available literature data including flow reactor, jet-stirred reactor, shock-tube ignition delay times, shock-tube speciation, flame speed, and flame speciation data. New ignition delay time measurements are presented for methane, dimethyl ether, and their mixtures; these data were obtained using three different shock tubes and a rapid compression machine. In addition to the DME/CH 4 blends, high-pressure data for pure DME and pure methane were also obtained. Where possible, the new * address:

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“…Historically, transient shock ignition phenomena have been utilized to generate conditions to study the ignition and combustion of homogenous premixed mixtures of gaseous fuels and oxidizers. Extensive literature exists on single pulse and reflected shock tube studies of premixed hydrogen-oxygen, methaneoxygen, and natural gas-oxygen mixtures (e.g., Eubank et al, 1981;Blumenthal et al, 1996;Huang et al, 2004). As noted earlier, much less work has addressed transient shock phenomena produced by compressed gas releases into air as a potential spontaneous ignition source.…”

Section: Simple Transient Shock Theory and Implicationsmentioning

confidence: 99%

Spontaneous Ignition of Pressurized Releases of Hydrogen and Natural Gas Into Air

Dryer

Chaos

Zhao

et al. 2007

Combustion Science and Technology

185

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This paper demonstrates the ''spontaneous ignition'' (autoignition=inflammation and sustained diffusive combustion) from sudden compressed hydrogen releases that is not well documented in the present literature, for which little fundamental explanation, discussion or research foundation exists, and which is apparently not encompassed in recent formulations of safety codes and standards for piping, storage, and use of high pressure compressed gas systems handling hydrogen. Accidental or intended, rapid failure of a pressure boundary separating sufficiently compressed hydrogen from air can result in multi-dimensional transient flows involving shock formation, reflection, and interactions such that reactant mixtures are rapidly formed and achieve chemical ignition, inflammation, and transition to turbulent jet diffusive combustion, fed by the continuing discharge of hydrogen. Both experiments and simple transient shock theory along with chemical kinetic ignition calculations are used to support interpretation of observations and qualitatively identify controlling gas properties and geometrical parameters. Although the phenomenon is demonstrated for pressurized hydrogen burst disk failures with different internal flow geometries, similar phenomena apparently do not necessarily occur for sudden boundary failures potential for producing ignition and continuing combustion. Much more experimental and computational work is required to quantitatively determine the envelope of parameter combinations that mitigate or enhance spontaneous ignition characteristics of compressed hydrogen as a result of sudden release, particularly if hydrogen is to become a major energy carrier interfaced with consumer use. Similar considerations for compressed methane, for mixtures of light hydrocarbons and methane (simulating natural gas), and for larger carbon number hydrocarbons show similar autoignition phenomena may occur with highly compressed methane or natural gas, but are unlikely with higher carbon number cases, unless the compressed source and=or surrounding air is sufficiently pre-heated above ambient temperature. Spontaneous ignition of compressed hydrocarbon gases is also generally less likely, given the much lower turbulent blow-off velocity of hydrocarbons in comparison to that for hydrogen.

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Shock-tube study of methane ignition under engine-relevant conditions: experiments and modeling

Cited by 156 publications

References 44 publications

Theoretical Analysis on the Injection of H2, CO, CH4 Rich Gases into the Blast Furnace

Theoretical Analysis on the Injection of H2, CO, CH4 Rich Gases into the Blast Furnace

An ignition delay and kinetic modeling study of methane, dimethyl ether, and their mixtures at high pressures

Spontaneous Ignition of Pressurized Releases of Hydrogen and Natural Gas Into Air

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