The effects of composition on the burning velocity and NO formation in premixed flames of C2H4+O2+N2

Konnov, Alexander A.; Dyakov, Igor; Ruyck, de J

doi:10.1016/j.expthermflusci.2007.11.017

Cited by 25 publications

(22 citation statements)

References 17 publications

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“…In methane + air [3] and CH 4 + O 2 + N 2 mixtures with different dilution ratios D = O 2 /(O 2 + N 2 ) [4,5], the model slightly over-predicts NO concentrations in lean flames and slightly under-predicts these in rich flames; overall good agreement was observed. In C 2 H 4 + O 2 + N 2 flames with dilution ratios D = 0.15-0.18 [6], the measurements were found to be in good agreement with those of Fenimore [9]. The predictions of the Konnov mechanism [2] in lean ethylene flames are in good agreement with the experiment; in rich flames, they reproduce trends of the experimental data with an under-prediction of about 10-15 ppm.…”

Section: Introductionsupporting

confidence: 78%

“…Sampling measurements were performed at distances of 10, 15, and 20 mm from the burner, and concentrations of stable species, CO, CO 2 , O 2 , and NO, were recorded [3][4][5][6][7][8]. The measured concentrations of CO, CO 2 , and O 2 were compared with the modeling to reveal the range of the flame conditions less affected by the ambient air entrainment.…”

Section: Resultsmentioning

confidence: 99%

“…In the following, the measurements of NO concentrations in the post-flame zone of different hydrocarbon + O 2 + N 2 flames at standard temperature and atmospheric pressure [3][4][5][6][7][8] are compared with the predictions of the original Konnov reaction mechanism [2] and with the same mechanism extended by the reaction of C 2 O with N 2 . One more modification was made: the thermodynamic data for C 2 O were updated to reflect the heat of formation, which is significantly higher (92.7 kcal/mole [11]) than the previously accepted value.…”

Section: Resultsmentioning

confidence: 99%

“…The goal of the present work was, therefore, to investigate a possible role of the re- action of C 2 O with N 2 through modeling of the experiments performed at atmospheric pressure [3][4][5][6][7][8] and implementing modifications proposed by Williams and Fleming [1].…”

Section: Introductionmentioning

confidence: 99%

“…Probe sampling measurements of NO concentrations in the post-flame zone of different hydrocarbon + O 2 + N 2 flames at standard temperature and atmospheric pressure have been performed and compared with predictions of the Konnov reaction mechanism [3][4][5][6][7][8]. In methane + air [3] and CH 4 + O 2 + N 2 mixtures with different dilution ratios D = O 2 /(O 2 + N 2 ) [4,5], the model slightly over-predicts NO concentrations in lean flames and slightly under-predicts these in rich flames; overall good agreement was observed.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

On the role of C2O radicals in the prompt-NO mechanism

Konnov

2008

Combust Explos Shock Waves

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The measurements of NO concentrations in the post-flame zone of different hydrocarbon + O 2 + N 2 flames at standard temperature and atmospheric pressure available in the literature are compared with predictions of the original Konnov reaction mechanism and with the same mechanism extended by the reaction of C 2 O with N 2 . The goal was to investigate the possible role of this reaction proposed by Williams and Fleming [P roc. Combust. Inst., Vol. 31 (2007), pp. 1109-1117]. This new reaction of C 2 O with N 2 seems to be a reasonable explanation of the deficiencies in the prompt-NO route. Direct comparisons of the experimental measurements performed in different flames with the modeling strongly suggests that the upper limit of this reaction rate constant is k = 7 · 10 11 exp(−17,000/RT ) [cm 3 /(mole · sec)].

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Section: Introductionsupporting

confidence: 78%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

On the role of C2O radicals in the prompt-NO mechanism

Konnov

2008

Combust Explos Shock Waves

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Laminar flame speed measurement and combustion mechanism optimization for ethylene–air mixtures

Wang,

Hou,

Zhang

et al. 2024

Asia-Pacific J Chem Eng

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Ethylene plays a crucial role as an intermediate component in the cracking and combustion processes of large molecular alkane and olefins. In this article, the laminar flame speed of ethylene–air mixtures was measured using the heat flux method. The mechanism of ethylene was simplified by utilizing the error propagation directed relationship graph (DRGEP) and sensitivity analysis (SA), and the Arrhenius pre‐exponential factors for 20 selected reactions in the skeletal mechanism were optimized using the particle swarm optimization (PSO) algorithm. Finally, an ethylene optimization mechanism including 39 species and 85 reactions was obtained. The prediction results for flame speed, ignition delay time, and species concentration were compared with experimental data and other mechanisms, covering a wide range of temperatures (298–1725 K), pressures (1–22.8 atm), and equivalence ratios (0.5–2.0). The findings demonstrate that the optimization mechanism not only improves the prediction results of laminar flame speed in the rich combustion zone and low oxygen environment but also enhances the prediction accuracy of the ignition delay time at high pressure and in the lean combustion zone, as well as the prediction accuracy of C2H4 and H2O radicals. In conclusion, the optimized mechanism exhibits higher accuracy and broader applicability.

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Quantifying acetylene mole fraction in rich flat laminar premixed C2H4/air flames using mid-infrared polarization spectroscopy

2023

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Mid-infrared laser polarization spectroscopy (IRPS) has been applied to measure the mole fraction of acetylene in rich premixed laminar C2H4/Air flat flames at equivalence ratios (Φ) of 1.7, 2.1, and 2.3, and under atmospheric pressure. The detection was conducted by probing the ro-vibrational P(19) transition at ~ 3.1 μm. The total collisional broadening coefficient of C2H2 was approximately 0.074 cm−1 atm−1 and varied within a range of 0.5% under different flame conditions, which made the effect of linewidth not obvious in the CH4/air flame. The calculated mole fraction of C2H2, using the Chemkin model, at Φ = 1.3 and 1.5 was used to calibrate the recorded IRPS signal intensities at different Height Above Burner (HAB). A single scaling factor was then used to quantify the measured C2H2 at highly sooting conditions, Φ = 1.7, 2.1, and 2.3, with a Limit of Detection (LoD) of 35 ± 5 ppm. The first observed C2H2 mole fraction appeared at HAB of 3 mm and measured as 2003 ppm, 2217 ppm, and 2495 ppm, for Φ = 1.7, 2.1, and 2.3, respectively. The mole fraction increased as the HAB increased to reach the maximum value of 2296 ppm, 2807 ppm, and 3478 ppm, for Φ = 1.7, 2.1, and 2.3, respectively, up to HAB of 5 mm. It was observed that the C2H2 mole fraction reaches a plateau region at HAB of ~ 8 mm. The production of C2H2 has been observed to be subject to a critical gas temperature of 1400 ± 30 K. The critical soot inception temperature, where the first incepted soot particles are observed, is the same as the gas temperature where $${\chi }_{{{\mathrm{C}}_{2}\mathrm{H}}_{2}}^{\mathrm{max}}$$ χ C 2 H 2 max was detected, namely at 1500 ± 30 K. These measurements and calibration procedure demonstrate a plausible technique to probe other flames and to better understand soot inception and its correlation with C2H2.

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The effects of composition on the burning velocity and NO formation in premixed flames of C2H4+O2+N2

Cited by 25 publications

References 17 publications

On the role of C2O radicals in the prompt-NO mechanism

On the role of C2O radicals in the prompt-NO mechanism

Laminar flame speed measurement and combustion mechanism optimization for ethylene–air mixtures

Quantifying acetylene mole fraction in rich flat laminar premixed C2H4/air flames using mid-infrared polarization spectroscopy

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