Structure and laminar flame speed of an ammonia/methane/air premixed flame under varying pressure and equivalence ratio

Rodolfo C. Rocha, Shenghui Zhong, Leilei Xu, Xue Song Bai, Maìrio Costa, Xiao Cai, Haisol Kim, Christian Brackmann, Zhongshan Li, Marcus Aldeìn

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskriftPeer review

10 Citeringar (SciVal)

Sammanfattning

This paper presents a joint experimental and numerical study on premixed laminar ammonia/methane/air flames, aiming to characterize the flame structures and NO formation and determine the laminar flame speed under different pressure, equivalence ratio, and ammonia fraction in the fuel. The experiments were carried out in a lab-scale pressurized vessel with a Bunsen burner installed with a concentric co-flow of air. Measurements of NH and NO distributions in the flames were made using planar laser-induced fluorescence. A novel method was presented for determination of the laminar flame speed from Bunsen-burner flame measurements, which takes into account the non-uniform flow in the unburned mixture and local flame stretch. NH profiles were chosen as flame front markers. Direct numerical simulation of the flames and one-dimensional chemical kinetic modeling were performed to enhance the understanding of flame structures and evaluate three chemical kinetic mechanisms recently reported in the literature. The stoichiometric and fuel-rich flames exhibit a dual-flame structure, with an inner premixed flame and an outer diffusion flame. The two flames interact, which affects the NO emissions. The impact of the diffusion flame on the laminar flame speed of the inner premixed flame is however minor. At elevated pressures or higher ammonia/methane ratios, the emission of NO is suppressed as a result of the reduced radical mass fraction and promoted NO reduction reactions. It is found that the laminar flame speed measured in the present experiments can be captured by the investigated mechanisms, but quantitative predictions of the NO distribution require further model development.

Originalspråkengelska
Sidor (från-till)7179-7192
Antal sidor14
TidskriftEnergy and Fuels
Volym35
Utgåva9
DOI
StatusPublished - 2021 maj

Ämnesklassifikation (UKÄ)

  • Atom- och molekylfysik och optik
  • Energiteknik
  • Strömningsmekanik och akustik

Fingeravtryck

Utforska forskningsämnen för ”Structure and laminar flame speed of an ammonia/methane/air premixed flame under varying pressure and equivalence ratio”. Tillsammans bildar de ett unikt fingeravtryck.

Citera det här