Numerical Investigation on the Flame Structure and CO/NO Formations of the Laminar Premixed Biogas–Hydrogen Impinging Flame in the Wall Vicinity

Zhilong Wei, Lei Wang, Hu Liu, Zihao Liu and Haisheng Zhen
Additional contact information
Zhilong Wei: Mechanical and Electrical Engineering College, Hainan University, Haikou 570228, China
Lei Wang: Mechanical and Electrical Engineering College, Hainan University, Haikou 570228, China
Hu Liu: Mechanical and Electrical Engineering College, Hainan University, Haikou 570228, China
Zihao Liu: Mechanical and Electrical Engineering College, Hainan University, Haikou 570228, China
Haisheng Zhen: Mechanical and Electrical Engineering College, Hainan University, Haikou 570228, China

Energies, 2021, vol. 14, issue 21, 1-16

Abstract: The near-wall flame structure and pollutant emissions of the laminar premixed biogas-hydrogen impinging flame were simulated with a detailed chemical mechanism. The spatial distributions of the temperature, critical species, and pollutant emissions near the wall of the laminar premixed biogas–hydrogen impinging flame were obtained and investigated quantitatively. The results show that the cold wall can influence the premixed combustion process in the flame front, which is close to the wall but does not touch the wall, and results in the obviously declined concentrations of OH, H, and O radicals in the premixed combustion zone. After flame quenching, a high CO concentration can be observed near the wall at equivalence ratios ( φ ) of both 0.8 and 1.2. Compared with that at φ = 1.0, more unburned fuel is allowed to pass through the quenching zone and generate CO after flame quenching near the wall thanks to the suppressed fuel consumption rate near the wall and the excess fuel in the unburned gases at φ = 0.8 and 1.2, respectively. By isolating the formation routes of NO production, it is found that the fast-rising trend of NO concentration near the wall in the post flame region at φ = 0.8 is attributed to the NO transportation from the NNH route primarily, while the prompt NO production accounts for more than 90% of NO generation in the wall vicinity at φ = 1.2. It is thus known that, thanks to the effectively increased surface-to-volume ratio, the premixed combustion process in the downsized chamber will be affected more easily by the amplified cooling effects of the cold wall, which will contribute to the declined combustion efficiency, increased CO emission, and improved prompt NO production.

Keywords: near-wall flame structure; CO and NO formations; biogas–hydrogen blends; impinging flame (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2021
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1996-1073/14/21/7308/pdf (application/pdf)
https://www.mdpi.com/1996-1073/14/21/7308/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:14:y:2021:i:21:p:7308-:d:671782

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().