Effects of pressure and carbon dioxide, hydrogen and nitrogen concentration on laminar burning velocities and NO formation of methane-air mixtures

Zahedi, Peyman; Yousefi, Kianoosh

doi:10.1007/s12206-013-0970-5

Cited by 60 publications

(30 citation statements)

References 33 publications

(39 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, gas turbine combustors are intrinsically different from industrial furnaces as they operate under high-pressure levels typically in the CONTACT Hesham M. Khalil hekhalil@alexu.edu.eg range of 5-50 bars. It is well understood that increasing pressure leads to a subsequent reduction of the laminar flame speed as it slows down species molecular diffusion (s L ∼ p −1/2 ) (Goswami et al, 2013;Zahedi & Yousefi, 2014). However, it also induces smaller turbulent scales, which in turn results in higher flame front wrinkling.…”

Section: Introductionmentioning

confidence: 99%

Increased heat transfer to sustain flameless combustion under elevated pressure conditions – a numerical study

Khalil

Eldrainy

Abdelghaffar

et al. 2019

Engineering Applications of Computational Fluid Mechanics

View full text Add to dashboard Cite

Sustaining flameless combustion under elevated pressure conditions remains a challenge that hinders its application in gas turbines. Previous attempts succeeded to sustain flameless operation up to 5 atm. In the present work, reaction rate is decreased by increasing heat transfer through combustor walls so that the reaction zone is kept distributed. Pressure is elevated from 1 to 15 atm. and its effect on reaction zone location and spread, and emissions is investigated. Two-dimensional computations are performed using ANSYS fluent package. Under adiabatic combustor wall conditions, increasing the pressure results in a more concentrated reaction zone, and a departure from flameless mode at 3 atm. The calculated Damköhler number is noticed to increase from 0.2 to 1.9. NO x emissions increases from 10 to 78 ppm. Nearly 90 % of the predicted NO x are generated via the thermal route. Under isothermal combustor wall conditions, increased heat transfer is noticed to limit the increase in heat of reaction and temperature with pressure. The calculated Damköhler number is noticed to increase from 0.12 to 0.85. This is nearly half the values encountered under adiabatic conditions, which demonstrate a distributed reaction under all pressures investigated. Finally, NO x emissions are found below 5 ppm for all pressures investigated.

show abstract

Section: Introductionmentioning

confidence: 99%

Increased heat transfer to sustain flameless combustion under elevated pressure conditions – a numerical study

Khalil

Eldrainy

Abdelghaffar

et al. 2019

Engineering Applications of Computational Fluid Mechanics

View full text Add to dashboard Cite

show abstract

“…Zahedi and Yousefi [25] studied numerically the effect of pressure and hydrogen addition on NO formation in a methane-air stoichiometric flame, using the GRImech3.0 mechanism [13].…”

Section: Introductionmentioning

confidence: 99%

Effect of hydrogen addition on NOx formation in high-pressure counter-flow premixed CH4/air flames

Persis

Idir

Molet

et al. 2019

International Journal of Hydrogen Energy

View full text Add to dashboard Cite

A laboratory-scale laminar counterflow burner was used to investigate NO formation in high pressure premixed CH4/H2/air flames. New experimental results on NO measurements by LIF were obtained at high pressure in CH4/H2/air flames with H2 content fixed at 20% in the fuel at pressures ranging from 0.1 to 0.7 MPa and an equivalence ratio progressively decreased from 0.74 to 0.6. The effects of hydrogen addition, equivalence ratio and pressure are discussed. These results are satisfactorily compared to the simulations using two detailed mechanisms: GDF ® kin3.0_NOmecha2.0 and the mechanism from Klippenstein et al., which are the most recent high-pressure NOx formation mechanisms available in the literature. A kinetic analysis based on Rate of Production/Rate of Consumption and sensitivity analyses of NO is then presented to identify the main pathways that lead to the formation and consumption of NO. In addition, the effect of hydrogen addition on NO formation pathways is described and analysed.

show abstract

“…For any diluent, the effect of its addition could be either dilution, transport and thermal diffusions, chemical, or their combinations, as below (Zahedi et al, 2014):…”

Section: Introductionmentioning

confidence: 99%

Numerical Study of Laminar Premixed Methane/Air Flames With Carbon Dioxide Dilution

Mendieta¹,

Alviso²,

Santos³

2016

Procceedings of the 16th Brazilian Congress of Thermal Sciences and Engineering

View full text Add to dashboard Cite

In this work carbon dioxide dilution on the laminar premixed methane/air flames was studied by means of kinetic modelling. This study contributes to the understandings of the effect of CO 2 concentrations on the combustion characteristics of biogas. The simulations were performed using the REGATH package with GRI 3.0 chemical scheme. Dilution from 0% to 50% CO 2 (volume) were computed at atmospheric pressure of 0.1 MPa an inlet temperature of 298 K with equivalence ratios from 0.7 to 1.3. Laminar flame speeds were estimated using a one-dimensional premixed flame model. The laminar flame speed and flame temperature of CH 4 /air decreased with increasing CO 2 dilution. The increase in CO 2 concentrations reduced the reactants' concentrations, decreasing the net reaction rate and thus the flame speed.

show abstract

Effects of pressure and carbon dioxide, hydrogen and nitrogen concentration on laminar burning velocities and NO formation of methane-air mixtures

Cited by 60 publications

References 33 publications

Increased heat transfer to sustain flameless combustion under elevated pressure conditions – a numerical study

Increased heat transfer to sustain flameless combustion under elevated pressure conditions – a numerical study

Effect of hydrogen addition on NOx formation in high-pressure counter-flow premixed CH4/air flames

Numerical Study of Laminar Premixed Methane/Air Flames With Carbon Dioxide Dilution

Contact Info

Product

Resources

About