Effects of radiation reabsorption on laminar NH3/H-2/air flames

Zheng, Shu1; Liu, Hao1; Sui, Ran2; Zhou, Bo3; Lu, Qiang1

2022

10.1016/j.combustflame.2021.111699

COMBUSTION AND FLAME   影响因子和分区

0010-2180

1556-2921

Ammonia combustion, owing to its zero greenhouse gas CO2 emission, is attracting attention for energy utilization. However, the thermal radiation of NH3 has not been reported and involved in the numerical simulations of ammonia flames, which may cause serious errors in estimating the laminar flame speeds. In this study, the effects of radiation reabsorption on the laminar flame speed at different equivalence ratios and elevated pressures were numerically investigated using planar NH3/H-2/air flames. The Statistical Narrow-Band (SNB) model parameters for NH3 were generated and used for simulations of NH3/H-2/Air flames, considering the radiation reabsorption. It was found that the radiation reabsorption exhibited a non-monotonic behavior at phi = 0.65-1.6, with the maximum enhancement of flame speed up to 15.6%. The effects of radiation reabsorption were controlled by both radiation and chemistry. The preheat-induced chemical effect dominated at phi = 0.65-1.25 and the enhancement of flame speed was mainly influenced by H, OH and NH2 radicals, which were primarily controlled by the reactions R36, R257 and R246, respectively. In contrast, the direct radiation effect dominated at phi = 1.25-1.6 and the enhancement of flame speed was mainly affected by the increasing mole fraction of NH3. With increasing pressures, the preheat-induced chemical effect dominated at P = 1-10 atm and the enhancement of flame speed were mainly impacted by H and NNH radicals, which were controlled by the reactions R44 and R257, respectively. At higher pressures above 10 atm, direct radiation effect was dominating and the enhancement of flame speed was mainly controlled by the increasing optical thickness. (C) 2021 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Radiation reabsorption Ammonia flame Flame speed Elevated pressure

SCI ; EI

英语

其他

National Key Research Development Program of China[2017YFB0601900] ; National Natural Science Foundation of China[51976057,51922040,51827808] ; Fundamental Research Funds for the Central Universities["2020JG005","2020DF01"] ; Foundation of State Key Laboratory of Coal Combustion[FSKLCCA2104] ; Hunan Science and Technology Planning Project[2020RC5008] ; Stable Support Plan Program of Shenzhen Natural Science Fund Grant[20200925155430 003]

Thermodynamics ; Energy & Fuels ; Engineering

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

WOS:000735903800013

ELSEVIER SCIENCE INC

20213610853248

Combustion ; Energy utilization ; Greenhouse gases ; Heat radiation ; Preheating ; Radiation effects ; Speed

Air Pollution Sources:451.1 ; Energy Utilization:525.3 ; Heat Transfer:641.2 ; Process Heating:642.1 ; Inorganic Compounds:804.2

ENGINEERING

Web of Science

1.North China Elect Power Univ, Natl Engn Lab Biomass Power Generat Equipment, Beijing 102206, Peoples R China
2.Missouri Univ Sci & Technol, Dept Mech & Aerosp Engn, Rolla, MO 65409 USA
3.Southern Univ Sci & Technol, Dept Mech & Aerosp Engn, Shenzhen 518055, Peoples R China

Zheng, Shu,Liu, Hao,Sui, Ran,et al. Effects of radiation reabsorption on laminar NH3/H-2/air flames[J]. COMBUSTION AND FLAME,2022,235.

Zheng, Shu,Liu, Hao,Sui, Ran,Zhou, Bo,&Lu, Qiang.(2022).Effects of radiation reabsorption on laminar NH3/H-2/air flames.COMBUSTION AND FLAME,235.

Zheng, Shu,et al."Effects of radiation reabsorption on laminar NH3/H-2/air flames".COMBUSTION AND FLAME 235(2022).