NOx formation in natural gas combustion—a new simplified reaction scheme for CFD calculations

Löffler, G.; Sieber, R.; Harasek, Michael; Hofbauer, Hermann; Hauss, R.; Landauf, J.

doi:10.1016/j.fuel.2005.07.012

Cited by 51 publications

(16 citation statements)

References 19 publications

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“…It could of course be argued that a surrogate mixture can never represent reality in a totally satisfactory manner, but the inherent complexity of real fuels has to be simplified in order to permit three-dimensional computational fluid dynamic simulations-as, for example, in trying to optimize natural gas burners for minimal NOx emissions [16].…”

Section: Introductionmentioning

confidence: 99%

Methane/ethane/propane mixture oxidation at high pressures and at high, intermediate and low temperatures

Healy

Curran

Simmie

et al. 2008

Combustion and Flame

107

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The oxidation of methane/ethane/propane mixtures, for blends containing 90/6.6/3.3, 70/15/15 and 70/20/10 percent by volume of each fuel respectively in 'air,' has been studied over the temperature range 770-1580 K, at compressed gas pressures of approximately 1, 10, 20, 30, 40 and 50 atm, and at equivalence ratios of 0.5, 1.0 and 2.0 using both a high-pressure shock tube and a rapid compression machine. The present work represents the most comprehensive set of methane/ethane/propane ignition delay time measurements available in a single study which extends the composition envelope over an industrially relevant pressure range. It is also the first such study to present ignition delay times at significantly overlapping conditions from both a rapid compression machine and a shock tube. The data were simulated using a detailed chemical kinetic model comprised of 289 species and 1580 reactions. It was found that qualitatively, the model reproduces correctly the effect of change in equivalence ratio and pressure, predicting that fuel-rich, high-pressure mixtures ignite fastest while fuel-lean, low-pressure mixtures ignite slowest. Moreover, the reactivity as a function of temperature is well captured with the model predicting negative temperature coefficient behavior similar to the experiments. Quantitatively the model is in general excellent agreement with the experimental results but is faster than experiment for the fuel-rich (φ = 2.0) mixture containing the highest quantity of propane (70/15/15 mixture) at the lowest temperatures (770-900 K).

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Section: Introductionmentioning

confidence: 99%

Methane/ethane/propane mixture oxidation at high pressures and at high, intermediate and low temperatures

Healy

Curran

Simmie

et al. 2008

Combustion and Flame

107

View full text Add to dashboard Cite

show abstract

“…The principal source of NO formation via the Zeldovich mechanism is the oxidation of molecular air nitrogen through two-stage reactions (O+N 2 ↔NO+N and N+O 2 ↔NO+O). In accordance with this mechanism, a rate of NO formation is highly limited by the first-step reaction, determining a break-up of the nitrogen triplebond with high energy of activation (E/R=38000) and low-rates of reactions k=Aexp(-E/RT) below 1600K [13]. Moreover, it should be noted that NO formation in the flame reaction zone is a result of competing thermodynamic, chemical and fluid dynamic factors, depending on the fuel-air equivalence ratio, degree of fuel-air premixing the inlet air temperature, the residence time in the flame reaction zone and flow velocity.…”

Section: The Experimental Results and Discussionmentioning

confidence: 91%

Modification of Wood Pellets and Propane Co-firing in a Magnetic Field

Barmina¹,

Zake²,

Krishko³

et al. 2010

Scientific Journal of Riga Technical University. Environmental and Climate Technologies

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-When burning fossil fuels and renewable energy resources, greenhouse emissions (GHG) are emitted into the atmosphere. One of the options to reduce GHG emissions is to apply a magnetic field. The effect of a gradient magnetic field on the gasification of renewable fuel and the combustion of volatiles by applying the field to the bottom part of the swirl flame with recirculation is studied for the conditions of field-enhanced reverse heat and mass transfer of paramagnetic flame species up to the layer of wood pellets. The aim of research to investigate the magnetic field effect on swirling flame dynamics for the conditions of self-sustaining wood fuel combustion and by cofiring with propane flow.

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“…Also, in the simulations these contributions depend on the selection of parameters. In the literature, there are several papers in which the relative weight of the NO formation routes is investigated (see, e.g., [37,40,[51][52][53][54][55][56][57]). Investigations of the various routes that are based on systematically modified mechanisms obtained by deleting one or more NO formation routes [37,52,53,55] neglect the cooperation of the reactions of the different routes.…”

Section: Uncertainty Analysis Of the No X Mechanismmentioning

confidence: 99%

Uncertainty analysis of NO production during methane combustion

Zsély

Zádor

Turányi

2008

Int J of Chemical Kinetics

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Local and Monte Carlo uncertainty analyses of NO production during methane combustion were carried out, investigating the effect of uncertainties of kinetic parameters and enthalpies of formation. In Case I, the original Leeds methane oxidation mechanism with the NO x reaction block was used, but the enthalpies of formation of all species were updated. In Case II, the NCN-containing reactions of the prompt NO formation route were added and the rate parameters of several reactions were also updated. The NO production was examined at the conditions of the Bartok et al. experiments (PSR, T = 1565-1989 K, ϕ = 0.8-1.2, residence time 3 ms). The Monte Carlo analysis provided the approximate probability density function and the variance of the calculated NO concentration, and also its attainable minimum and maximum values. Both mechanisms provided similarly good to acceptable agreement with the experimental results for lean and stoichiometric mixtures, whereas only mechanism Case II could reproduce the experimental data for rich mixtures after a realistic tuning of the parameters. Local uncertainty analysis was used to assess the contribution of the uncertainty of each parameter to the uncertainty of the calculated NO concentration. Enthalpies of formation of NNH and HCCO, and rate parameters of 20 reaction steps cause most of the uncertainty of the calculated NO concentrations at all conditions. The relative importance of the four main NO formation routes was investigated via the inspection of the reaction rates, embedded in the Monte Carlo analysis. NO formation in rich mixtures was dominated by the prompt route, whereas in leaner mixtures the share of the NO formation routes depended very much on the values of rate parameters, when varied within the uncertainty limits of kinetic data evaluations.

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NOx formation in natural gas combustion—a new simplified reaction scheme for CFD calculations

Cited by 51 publications

References 19 publications

Methane/ethane/propane mixture oxidation at high pressures and at high, intermediate and low temperatures

Methane/ethane/propane mixture oxidation at high pressures and at high, intermediate and low temperatures

Modification of Wood Pellets and Propane Co-firing in a Magnetic Field

Uncertainty analysis of NO production during methane combustion

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