Numerical study on NO formation in CH4-O2-N2 diffusion flame diluted with CO2

2005 ◽  
Vol 29 (2) ◽  
pp. 107-120 ◽  
Author(s):  
Dong-Jin Hwang ◽  
Jeong Park ◽  
Chang-Bo Oh ◽  
Kyung-Hwan Lee ◽  
Sang-In Keel
Keyword(s):  
Diffusion Flame ◽  
Numerical Study ◽  
No Formation

Numerical study on flame structure and NO formation in CH4-O2-N2 counterflow diffusion flame diluted with H2O

2004 ◽  
Vol 28 (14) ◽  
pp. 1255-1267 ◽  
Author(s):  
Dong-Jin Hwang ◽  
Jong-Wook Choi ◽  
Jeong Park ◽  
Sang-In Keel ◽  
Chang-Bo Ch ◽  
...  
Keyword(s):  
Diffusion Flame ◽  
Numerical Study ◽  
Flame Structure ◽  
No Formation ◽  
Counterflow Diffusion Flame

scholarly journals Effects of strain rate and CO2 on no formation in CH4/N2/O2 counter-flow diffusion flames

2018 ◽  
Vol 22 (Suppl. 2) ◽  
pp. 769-776
Author(s):  
Fei Ren ◽  
Longkai Xiang ◽  
Huaqiang Chu ◽  
Weiwei Han
Keyword(s):  
Strain Rate ◽  
Diffusion Flames ◽  
Numerical Study ◽  
Flame Temperature ◽  
Co2 Concentration ◽  
No Production ◽  
Counter Flow ◽  
Detailed Chemistry ◽  
No Formation ◽  
Key Factor

The reduction of nitrogen oxides in the high temperature flame is the key factor affecting the oxygen-enriched combustion performance. A numerical study using an OPPDIF code with detailed chemistry mechanism GRI 3.0 was carried out to focus on the effect of strain rate (25-130 s?1) and CO2 addition (0-0.59) on the oxidizer side on NO emission in CH4 / N2 / O2 counter-flow diffusion flame. The mole fraction profiles of flame structures, NO, NO2 and some selected radicals (H, O, OH) and the sensitivity of the dominant reactions contributing to NO formation in the counter-flow diffusion flames of CH4\/ N2 /O2 and CH4 / N2 / O2 / CO2 were obtained. The results indicated that the flame temperature and the amount of NO were reduced while the sensitivity of reactions to the prompt NO formation was gradually increased with the increasing strain rate. Furthermore, it is shown that with the increasing CO2 concentration in oxidizer, CO2 was directly involved in the reaction of NO consumption. The flame temperature and NO production were decreased dramatically and the mechanism of NO production was transformed from the thermal to prompt route.

A Numerical Study on a V-Shaped Laminar Stratified Flame

2005 ◽  
Author(s):  
Hongsheng Guo ◽  
Gregory J. Smallwood ◽  
Cedric Galizzi ◽  
Dany Escudie´
Keyword(s):  
Diffusion Flame ◽  
Numerical Study ◽  
Premixed Flame ◽  
Intermediate Species ◽  
Governing Equations ◽  
Flame Zone ◽  
Rich Region ◽  
Detailed Chemistry ◽  
Stratified Charge ◽  
Diffusion Of Hydrogen

A V-shaped laminar stratified flame was investigated by numerical simulation. The primitive variable method, in which the fully elliptic governing equations were solved with detailed chemistry and complex thermal and transport properties, was used. The results indicate that in addition to the primary premixed flame, the stratified charge in a combustor causes the formation of a diffusion flame. The diffusion flame is located between the primary premixed flame branches. The fuel is fully decomposed and converted to some intermediate species, like CO and H2, in the primary premixed flame branches. Due to the shortage of oxygen, the formed CO and H2 in the fuel rich region of the premixed flame branch is further transported to the downstream until they meet the oxygen from the fuel lean region. This leads to the formation of the diffusion flame. There is an interaction between the diffusion flame and the primary premixed flame branches. The interaction intensifies the burning speed of the primary premixed flame. Both the heat transfer and the diffusion of hydrogen and some radicals cause the interaction. With the increase of the stratified charge region, the diffusion flame zone is enlarged and the interaction is enhanced.

scholarly journals A Numerical Study on the Effect of CO Addition on Flame Temperature and NO Formation in Counterflow CH4/Air Diffusion Flames

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Hongsheng Guo ◽  
W. Stuart Neill
Keyword(s):  
Carbon Monoxide ◽  
Strain Rate ◽  
Diffusion Flames ◽  
Numerical Study ◽  
Formation Rate ◽  
Flame Temperature ◽  
No Emission ◽  
No Formation ◽  
Air Diffusion ◽  
Emission Index

A numerical study was carried out to understand the effect of CO enrichment on flame temperature and NO formation in counterflow CH4/air diffusion flames. The results indicate that when CO is added to the fuel, both flame temperature and NO formation rate are changed due to the variations in adiabatic flame temperature, fuel Lewis number, and chemical reaction. At a low strain rate, the addition of carbon monoxide causes a monotonic decrease in flame temperature and peak NO concentration. However, NO emission index first slightly increases, and then decreases. At a moderate strain rate, the addition of CO has negligible effect on flame temperature and leads to a slight increase in both peak NO concentration and NO emission index, until the fraction of carbon monoxide reaches about 0.7. Then, with a further increase in the fraction of added carbon monoxide, all three quantities quickly decrease. At a high strain rate, the addition of carbon monoxide causes increase in flame temperature and NO formation rate, until a critical carbon monoxide fraction is reached. After the critical fraction, the further addition of carbon monoxide leads to decrease in both flame temperature and NO formation rate.

scholarly journals Numerical Study of Unsteady Properties of Ethylene/Air Turbulent Jet Diffusion Flame with Detached Eddy Simulation

2016 ◽  
Vol 33 (4) ◽  
Author(s):  
Sugang Ma ◽  
Fengquan Zhong ◽  
Xinyu Zhang
Keyword(s):  
Diffusion Flame ◽  
Error Propagation ◽  
Numerical Study ◽  
Kinetic Mechanism ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Turbulent Plane ◽  
Ignition And Combustion ◽  
Relation Graph ◽  
Plane Jet

AbstractIn this paper, unsteady process of ignition and combustion of turbulent plane-jet diffusion flame of ethylene/air is numerically simulated with detached eddy simulation (DES) and a reduced kinetic mechanism of ethylene. The kinetic mechanism consisting of 25 species and 131 steps is reduced from a 25 species/131 steps detailed mechanism via the method of error-propagation-based directed relation graph (DRGEP). The DES results of averaged temperature profiles at varied downstream locations are compared with the DNS results of Yoo et al. [

Sign in / Sign up

Export Citation Format

Share Document