A Detailed Numerical Study of NOx Kinetics in Counterflow Methane Diffusion Flames: Effects of Fuel-Side versus Oxidizer-Side Dilution
Dilution combustion has been widely utilized due to various merits, such as enhanced efficiency, fewer pollutants emissions, and even a promising future in alleviating global warming. Diluents can be introduced through the oxidizer or fuel side to achieve the desired combustion properties, and H2O a...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2021-01-01
|
| Series: | Journal of Combustion |
| Online Access: | http://dx.doi.org/10.1155/2021/6642734 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850225712334635008 |
|---|---|
| author | Huanhuan Xu Fengshan Liu Zhiqiang Wang Xiaohan Ren Juan Chen Qiang Li Zilin Zhu |
| author_facet | Huanhuan Xu Fengshan Liu Zhiqiang Wang Xiaohan Ren Juan Chen Qiang Li Zilin Zhu |
| author_sort | Huanhuan Xu |
| collection | DOAJ |
| description | Dilution combustion has been widely utilized due to various merits, such as enhanced efficiency, fewer pollutants emissions, and even a promising future in alleviating global warming. Diluents can be introduced through the oxidizer or fuel side to achieve the desired combustion properties, and H2O and CO2 are the most common ones. A comprehensive comparison between the different dilution methods still lacks understanding and optimizes the dilution combustion technologies. This study numerically compared the effects of H2O and CO2 dilution in the oxidizer or fuel stream on counterflow methane diffusion flames, emphasizing NO formation kinetics. Results showed that the impact of different radiation heat transfer models on NO emissions diminishes with increasing the dilution ratio. The calculations of radiation heat transfer were treated in three ways: radiation-neglected, optically thin, and using a nongrey radiation model. When keeping the oxygen content and methane fraction constant, CO2 dilution in the air-side has the most profound influence on NO reduction, and CO2 dilution in the fuel-side has the least. H2O dilution showed a medium impact with a larger degree on air-side than that on fuel-side. To gain a deeper understanding of this effect order, the contributions of different NO formation routes were quantified, and analyses were made based on the diluents’ chemical and thermal effects. It was found that the oxidizer-side dilution and fuel-side dilution affect the NO formation pathway similarly. Still, the influence of H2O dilution on the NO formation pathway differs from that of CO2 dilution. |
| format | Article |
| id | doaj-art-5b9f37608a9543d2b319b0bbda65b501 |
| institution | OA Journals |
| issn | 2090-1968 2090-1976 |
| language | English |
| publishDate | 2021-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Journal of Combustion |
| spelling | doaj-art-5b9f37608a9543d2b319b0bbda65b5012025-08-20T02:05:16ZengWileyJournal of Combustion2090-19682090-19762021-01-01202110.1155/2021/66427346642734A Detailed Numerical Study of NOx Kinetics in Counterflow Methane Diffusion Flames: Effects of Fuel-Side versus Oxidizer-Side DilutionHuanhuan Xu0Fengshan Liu1Zhiqiang Wang2Xiaohan Ren3Juan Chen4Qiang Li5Zilin Zhu6National Engineering Laboratory for Reducing Emissions from Coal Combustion, School of Energy and Power Engineering, Shandong University, Jinan 250061, ChinaMeasurement Science and Standards, National Research Council Canada, Building M-9 1200, Montreal Road, Ottawa, ON K1A 0R6, CanadaNational Engineering Laboratory for Reducing Emissions from Coal Combustion, School of Energy and Power Engineering, Shandong University, Jinan 250061, ChinaInstitute of Thermal Science and Technology, Shandong University, 17923 Jingshi Road, Jinan 250061, Shandong, ChinaNational Engineering Laboratory for Reducing Emissions from Coal Combustion, School of Energy and Power Engineering, Shandong University, Jinan 250061, ChinaCollege of Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, ChinaNational Engineering Laboratory for Reducing Emissions from Coal Combustion, School of Energy and Power Engineering, Shandong University, Jinan 250061, ChinaDilution combustion has been widely utilized due to various merits, such as enhanced efficiency, fewer pollutants emissions, and even a promising future in alleviating global warming. Diluents can be introduced through the oxidizer or fuel side to achieve the desired combustion properties, and H2O and CO2 are the most common ones. A comprehensive comparison between the different dilution methods still lacks understanding and optimizes the dilution combustion technologies. This study numerically compared the effects of H2O and CO2 dilution in the oxidizer or fuel stream on counterflow methane diffusion flames, emphasizing NO formation kinetics. Results showed that the impact of different radiation heat transfer models on NO emissions diminishes with increasing the dilution ratio. The calculations of radiation heat transfer were treated in three ways: radiation-neglected, optically thin, and using a nongrey radiation model. When keeping the oxygen content and methane fraction constant, CO2 dilution in the air-side has the most profound influence on NO reduction, and CO2 dilution in the fuel-side has the least. H2O dilution showed a medium impact with a larger degree on air-side than that on fuel-side. To gain a deeper understanding of this effect order, the contributions of different NO formation routes were quantified, and analyses were made based on the diluents’ chemical and thermal effects. It was found that the oxidizer-side dilution and fuel-side dilution affect the NO formation pathway similarly. Still, the influence of H2O dilution on the NO formation pathway differs from that of CO2 dilution.http://dx.doi.org/10.1155/2021/6642734 |
| spellingShingle | Huanhuan Xu Fengshan Liu Zhiqiang Wang Xiaohan Ren Juan Chen Qiang Li Zilin Zhu A Detailed Numerical Study of NOx Kinetics in Counterflow Methane Diffusion Flames: Effects of Fuel-Side versus Oxidizer-Side Dilution Journal of Combustion |
| title | A Detailed Numerical Study of NOx Kinetics in Counterflow Methane Diffusion Flames: Effects of Fuel-Side versus Oxidizer-Side Dilution |
| title_full | A Detailed Numerical Study of NOx Kinetics in Counterflow Methane Diffusion Flames: Effects of Fuel-Side versus Oxidizer-Side Dilution |
| title_fullStr | A Detailed Numerical Study of NOx Kinetics in Counterflow Methane Diffusion Flames: Effects of Fuel-Side versus Oxidizer-Side Dilution |
| title_full_unstemmed | A Detailed Numerical Study of NOx Kinetics in Counterflow Methane Diffusion Flames: Effects of Fuel-Side versus Oxidizer-Side Dilution |
| title_short | A Detailed Numerical Study of NOx Kinetics in Counterflow Methane Diffusion Flames: Effects of Fuel-Side versus Oxidizer-Side Dilution |
| title_sort | detailed numerical study of nox kinetics in counterflow methane diffusion flames effects of fuel side versus oxidizer side dilution |
| url | http://dx.doi.org/10.1155/2021/6642734 |
| work_keys_str_mv | AT huanhuanxu adetailednumericalstudyofnoxkineticsincounterflowmethanediffusionflameseffectsoffuelsideversusoxidizersidedilution AT fengshanliu adetailednumericalstudyofnoxkineticsincounterflowmethanediffusionflameseffectsoffuelsideversusoxidizersidedilution AT zhiqiangwang adetailednumericalstudyofnoxkineticsincounterflowmethanediffusionflameseffectsoffuelsideversusoxidizersidedilution AT xiaohanren adetailednumericalstudyofnoxkineticsincounterflowmethanediffusionflameseffectsoffuelsideversusoxidizersidedilution AT juanchen adetailednumericalstudyofnoxkineticsincounterflowmethanediffusionflameseffectsoffuelsideversusoxidizersidedilution AT qiangli adetailednumericalstudyofnoxkineticsincounterflowmethanediffusionflameseffectsoffuelsideversusoxidizersidedilution AT zilinzhu adetailednumericalstudyofnoxkineticsincounterflowmethanediffusionflameseffectsoffuelsideversusoxidizersidedilution AT huanhuanxu detailednumericalstudyofnoxkineticsincounterflowmethanediffusionflameseffectsoffuelsideversusoxidizersidedilution AT fengshanliu detailednumericalstudyofnoxkineticsincounterflowmethanediffusionflameseffectsoffuelsideversusoxidizersidedilution AT zhiqiangwang detailednumericalstudyofnoxkineticsincounterflowmethanediffusionflameseffectsoffuelsideversusoxidizersidedilution AT xiaohanren detailednumericalstudyofnoxkineticsincounterflowmethanediffusionflameseffectsoffuelsideversusoxidizersidedilution AT juanchen detailednumericalstudyofnoxkineticsincounterflowmethanediffusionflameseffectsoffuelsideversusoxidizersidedilution AT qiangli detailednumericalstudyofnoxkineticsincounterflowmethanediffusionflameseffectsoffuelsideversusoxidizersidedilution AT zilinzhu detailednumericalstudyofnoxkineticsincounterflowmethanediffusionflameseffectsoffuelsideversusoxidizersidedilution |