Kinetics modeling of shock-induced ignition in low-dilution CH4/O2 mixtures at high pressures and intermediate temperatures

Petersen, Eric L.; Davidson, David F.; Hanson, Ronald K.

doi:10.1016/s0010-2180(98)00111-4

Cited by 241 publications

(167 citation statements)

References 55 publications

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“…The activation energy for the present study was calculated at 53.4±0.35 kcal/mol using a multiple linear regression. A comparison of this with the activation energies from other studies [10,[21][22][23][24][25] (Table 2) shows that the activation energy obtained here is slightly higher. This discrepancy may be attributed to differences in the experimental setup, experimental conditions, and dilution components among the studies.…”

Section: Results and Data Analysissupporting

confidence: 66%

“…However, HO· concentrations increase rapidly through R38, which will move reaction R98 to the right. Reaction R53 is usually considered as the main H· consumption step in the methane/hydrogen system [24,25]. In this study, reaction R53 enhances ignition, which is different to the results reported by Huang et al [12].…”

Section: H Ch H C Hcontrasting

confidence: 78%

“…Four elementary reactions, which are the key to the ignition mechanism of the methane/hydrogen reactive system, were improved. Because the experimental temperatures in the present study ranged from 1422-1877 K, the alkylperoxy chemistry, including the formation and consumption of CH 3 O 2 , at low temperatures proposed by Petersen et al [25] was ignored. For the ignition delay of methane/oxygen/argon mixtures or methane/ oxygen/nitrogen mixtures, the modified model based on GRI-Mech 3.0 can reproduce experimental results over a wide range of conditions.…”

Section: Kinetic Modelmentioning

confidence: 99%

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Experimental and kinetic study on ignition delay times of methane/hydrogen/oxygen/nitrogen mixtures by shock tube

et al. 2011

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Ignition delay times of methane/hydrogen/oxygen/nitrogen mixtures with hydrogen amount-of-substance fractions ranging from 0-20% were measured in a shock tube facility. The ambient temperature varied from 1422 to 1877 K and the pressure was maintained at 0.4 MPa behind the reflected shock wave. The experiments were conducted at an equivalence ratio of 2.0. The fuel mixtures were diluted with nitrogen gas so that the nitrogen amount-of-substance fraction was 95%. The experimental ignition delay time of the CH 4 /H 2 mixture decreased as the hydrogen amount-of-substance fraction increased. The enhancement of ignition by hydrogen addition was weak when the ambient temperature was >1750 K, and strong when the temperature was <1725 K. The ignition delay time of 20% H 2 /80% CH 4 was only one-third that of 100% CH 4 at 1500 K. A modified model based on GRI-Mech 3.0 was proposed and used to calculate the ignition delay times of test mixtures. The calculated results agreed with the experimental ignition delay times. Normalized sensitivity analysis showed that HO·+H 2 →H·+H 2 O was the main reaction for the formation of the H· at 1400 K. As the hydrogen amount-of-substance fraction increased, chain branching was enhanced through the reaction H·+O 2 →O·+HO·, and this reduced the ignition delay time. At 1800 K, the methyl radical (H 3 C·) became the key species that influenced the ignition of the CH 4 /H 2 /O 2 /N 2 mixtures, and sensitivity coefficients of the chain termination reaction 2H 3 C·(+M)→C 2 H 6 (+M), and chain propagation reaction HO 2 +H 3 C·→HO·+CH 3 O decreased, which reduced the influence of hydrogen addition on the ignition of the CH 4 /H 2 mixtures.shock tube, methane, hydrogen, chemical kinetics Citation:Zhang Y J, Huang Z H, Wei L J, et al. Experimental and kinetic study on ignition delay times of methane/hydrogen/oxygen/nitrogen mixtures by shock tube.

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Section: Results and Data Analysissupporting

confidence: 66%

Section: H Ch H C Hcontrasting

confidence: 78%

Section: Kinetic Modelmentioning

confidence: 99%

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Experimental and kinetic study on ignition delay times of methane/hydrogen/oxygen/nitrogen mixtures by shock tube

et al. 2011

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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.…”

supporting

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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“…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

396

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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Kinetics modeling of shock-induced ignition in low-dilution CH4/O2 mixtures at high pressures and intermediate temperatures

Cited by 241 publications

References 55 publications

Experimental and kinetic study on ignition delay times of methane/hydrogen/oxygen/nitrogen mixtures by shock tube

Experimental and kinetic study on ignition delay times of methane/hydrogen/oxygen/nitrogen mixtures by shock tube

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

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