Investigation of burning velocity of lean and rich premixed NH₃/H₂ turbulent flames using multi-scalar imaging

Li, Xun1; Wang, Ze1; Li, Tao2; Dreizler, Andreas2; Lipatnikov, Andrei N.3; Liu, Xiao4; Gan, Xiaohua1; Zhou, Bo1

2024

10.1016/j.proci.2024.105541

PROCEEDINGS OF THE COMBUSTION INSTITUTE   影响因子和分区

1540-7489

1873-2704

Two groups of both lean and rich NH3/H-2/O-2/N-2 turbulent premixed piloted jet flames with the same laminar flame speed are investigated using simultaneous multi-scalar laser diagnostics techniques including NH3/NH/OH planar laser induced fluorescence (PLIF) and Rayleigh scattering. One group uses air as the oxidizer and the other uses an adapted mixture of atomic N-to-H ratio of 1:3 associated with in-situ hydrogen production from ammonia cracking. Turbulent rms velocity u' is varied in a wide range by changing the bulk flow velocity. Global consumption speeds S-T,S- G are evaluated by measuring the inlet bulk flow rates of reactants and areas of time-averaged flame fronts extracted using different flame marker contours, i.e., c(NH3) = 0.3, c(NH) = 0.3 (inner contour), and c(OH) = 0.4, where c designates species number density normalized using its maximum value. The obtained results show the following trends to be emphasized. First, an increase in S-T,S- G,S-NH3 by u' is more pronounced when compared to two other global consumption speeds (S-T,S- G,S-NHi, where i indicates the inner contour, and S-T,S- G,S-OH) and is close to a linear dependence. The adapted mixture shows only a moderate influence on S-T,S- G,S-NH3 but not on the other two. Second, S-T,S- G,S-NH3 is weakly affected by variations in Lewis number Le. On the contrary, third, S-T,S- G,S-NHi is significantly higher in lean mixtures characterized by Le < 1 when compared to rich mixtures characterized by Le > 1. Fourth, these variations in S-T,S- G,S-NHi are reasonably well approximated introducing an empirical factor of Le(-0.9) into fitting S-T,S- G,S-NHi/S-L onto u'/S-L. The qualitative difference between sensitivities of S-T,S- G,S-NH3 and S-T,S- G,S-NHi to variations in Le is attributed to the fact that the NH3 and NH isosurfaces are localized to preheat and reaction zones, respectively, of the laminar flames. The reported experimental data imply different influence of differential diffusion on flame preheat and reaction zones, thus, calling for further research into the issue.

Ammonia/hydrogen NH3/NH/OH PLIF Turbulent burning velocity Flame structure Differential diffusion

SCI ; EI

英语

第一 ; 通讯

Thermodynamics ; Energy & Fuels ; Engineering

Thermodynamics ; Energy & Fuels ; Engineering, Chemical ; Engineering, Mechanical

WOS:001281404400001

ELSEVIER SCIENCE INC

ENGINEERING

Web of Science

1.Southern Univ Sci & Technol SUSTech, Dept Mech & Aerosp Engn, Shenzhen 518055, Peoples R China
2.Tech Univ Darmstadt, Dept Mech Engn React Flows & Diagnost, Otto Berndt Str 3, D-64287 Darmstadt, Germany
3.Chalmers Univ Technol, Dept Mech & Maritime Sci, S-41296 Gothenburg, Sweden
4.Harbin Engn Univ, Coll Power & Energy, Harbin 150001, Peoples R China

Li, Xun,Wang, Ze,Li, Tao,et al. Investigation of burning velocity of lean and rich premixed NH₃/H₂ turbulent flames using multi-scalar imaging[J]. PROCEEDINGS OF THE COMBUSTION INSTITUTE,2024,40(1-4).

Li, Xun.,Wang, Ze.,Li, Tao.,Dreizler, Andreas.,Lipatnikov, Andrei N..,...&Zhou, Bo.(2024).Investigation of burning velocity of lean and rich premixed NH₃/H₂ turbulent flames using multi-scalar imaging.PROCEEDINGS OF THE COMBUSTION INSTITUTE,40(1-4).

Li, Xun,et al."Investigation of burning velocity of lean and rich premixed NH₃/H₂ turbulent flames using multi-scalar imaging".PROCEEDINGS OF THE COMBUSTION INSTITUTE 40.1-4(2024).