Emission prediction and analysis on CH4/NH3/air swirl flames with LES-FGM method

An, Zhenhua; Zhang, Meng; Zhang, Weijie; Mao, Runze; Wei, Xutao; Wang, Jinhua; Huang, Zuohua; Tan, Houzhang

doi:10.1016/j.fuel.2021.121370

Cited by 74 publications

(28 citation statements)

References 35 publications

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“…An et al found that the OH and NO were closely correlated in premixed CH 4 /NH 3 /air flames as they were both strongly related to flame temperature. While N 2 O had a correlation with NH and HNO components (An et al, 2021), which is similar with the results by the same combustion group. (Zhang et al, 2020;Zhang et al, 2021b;Wei et al, 2021).…”

Section: No X Emissionssupporting

confidence: 90%

A Review on Combustion Characteristics of Ammonia as a Carbon-Free Fuel

Lai

Chen

et al. 2021

Front. Energy Res.

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A comprehensive review of combustion characteristics of ammonia (NH3) as a carbon free fuel is presented. NH3 is an attractive alternative fuel candidate to reduce the consumption of fossil fuel and the emission of CO2, soot, and hydrocarbon pollutants, due to its comparable combustion properties, productivities from renewable sources, and storage and transportation by current commercial infrastructure. However, the combustion properties of NH3 are quite different from conventional hydrocarbon fuels, which highlight the specific difficulties during the application of NH3. Therefore, this paper presents comparative experimental and numerical studies of the application of NH3 as a fuel during combustion process, including the combustion properties of laminar burning velocity, flame structures, pollutant emissions for the application of NH3 as a carbon free fuel. This paper presents the burning velocity and pollutant emissions of NH3 alone and mixtures with other fuels to improve the combustion properties. The aim of this paper is to review and describe the suitability of NH3 as a fuel, including the combustion and emission characteristics of NH3 during its combustion process.

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Section: No X Emissionssupporting

confidence: 90%

A Review on Combustion Characteristics of Ammonia as a Carbon-Free Fuel

Lai

Chen

et al. 2021

Front. Energy Res.

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“…Another challenge of ammonia combustion is the high NO emission. − Xiao et al reported ammonia/methane emission characteristics of gas turbines at different pressures and pointed out that NO emission decreased significantly with increasing pressure. Besides the impact of pressure, An et al revealed the significant impact of the NH 3 mole fraction on ammonia/methane flame NO emission, noting that sufficient concentrations of HNO, H, and OH caused NO emission to reach a peak value of about 4000 ppm when the ammonia ratio was close to 40%. In addition, the equivalence ratio also had an important impact on ammonia/methane flame emission .…”

Section: Introductionmentioning

confidence: 99%

Impacts of Radiation Reabsorption on the Flame Speed and NO Generation of CH₄/NH₃/Air Flames

Zheng

Líu

et al. 2023

Energy Fuels

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Partial replacement of methane with ammonia, a carbon-free fuel with promising application potential, can effectively reduce carbon emissions. In this paper, a numerical study on CH4/NH3/air one-dimensional (1D) premixed flames at different equivalence ratios was performed. The impacts on the laminar flame speed and NO generation by radiation reabsorption are discussed. It was clear that the improvement of flame speed under radiation impact showed a nonlinear tendency with an increasing equivalence ratio. The decisive factors were the preheat-induced chemical effect when ϕ = 0.6–1.2 and the direct radiation effect at ϕ = 1.2–1.5. The promotion effect on NO formation by radiation reabsorption decreased first and then increased with an increasing equivalence ratio, controlled by the reactions NH + NO ≤> N2O + H and NH + O2 ≤> NO + OH in lean combustion and N + OH ≤> NO + H and NH + O ≤> NO + H in rich combustion. NH i (i = 0, 1, 2) radicals were the main factors controlling the NO generation and conversion. The oxidation of CH4 participated in the generation and consumption of NO by generating OH, CH i , and CO2.

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“…In order to improve the characteristics of ammonia, more reactive fuels can be used for doping with ammonia, such as methane (Valera-Medina et al, 2015) and hydrogen (Zhang et al, 2022). Since methane is the main component of natural gas fuel widely used in gas turbines, using ammonia/methane blends is one way to promote ammonia as an alternative fuel to natural gas (An et al, 2021;Sun J. et al, 2022). To design an advanced gas turbine combustor, the ammonia/methane fuel in the combustor must achieve the goal of stable combustion and low NO x emission.…”

Section: Introductionmentioning

confidence: 99%

Premixed combustion and emission characteristics of methane diluted with ammonia under F-class gas turbine relevant operating condition

Zhang

Zhao

et al. 2023

Front. Energy Res.

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Ammonia has been used on a small scale in other industrial equipment, such as gas turbines, as a carbon-free fuel. However, ammonia fuel suffers disadvantages such as high ignition temperature, low flame velocity and high NOx emissions. Doping with ammonia using a more reactive fuel, such as methane, can solve the above problems. Therefore, under the relevant operating conditions of the gas turbine (T = 723 K, p = 16.5 atm), the effect of ammonia content on the combustion and emission characteristics of laminar premixed methane flames was numerically investigated. This research uses the PREMIX code from ANSYS CHEMKIN-PRO 2020 and Okafor chemical kinetic mechanisms and provides a reference for our subsequent analysis of gas turbine operating conditions. Firstly, the emission data of major pollutants under different ammonia content (XNH3 = 0–1.0) and equivalent ratio (Φ = .6–1.4) were calculated. Then, the laminar premixed flame structure is analyzed under the lean fuel conditions associated with gas turbines (Φ = .6, .8). Finally, the effect of ammonia addition on the chemical reaction path of NO and CO emission was studied. The results show that ammonia/methane mixture fuel is more suitable for combustion at .6 < Φ < .8 under high temperature and pressure. High ammonia content (XNH3 > .6) and low equivalent ratio can reduce NO and CO emissions. The molar fractions of H, O, and OH radicals and flame temperature decreased with the increase in ammonia content. In addition, high temperature and high pressure conditions and ammonia content greatly influence the reaction path of NO and CO production. The increase in pressure resulted in a change in the primary reaction that produced NO. In conclusion, this study guides reducing the emission of NO and CO from lean side of gas turbine plants.

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Emission prediction and analysis on CH4/NH3/air swirl flames with LES-FGM method

Cited by 74 publications

References 35 publications

A Review on Combustion Characteristics of Ammonia as a Carbon-Free Fuel

A Review on Combustion Characteristics of Ammonia as a Carbon-Free Fuel

Impacts of Radiation Reabsorption on the Flame Speed and NO Generation of CH₄/NH₃/Air Flames

Premixed combustion and emission characteristics of methane diluted with ammonia under F-class gas turbine relevant operating condition

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Emission prediction and analysis on CH4/NH3/air swirl flames with LES-FGM method

Cited by 74 publications

References 35 publications

A Review on Combustion Characteristics of Ammonia as a Carbon-Free Fuel

A Review on Combustion Characteristics of Ammonia as a Carbon-Free Fuel

Impacts of Radiation Reabsorption on the Flame Speed and NO Generation of CH4/NH3/Air Flames

Premixed combustion and emission characteristics of methane diluted with ammonia under F-class gas turbine relevant operating condition

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Impacts of Radiation Reabsorption on the Flame Speed and NO Generation of CH₄/NH₃/Air Flames