Effects of CO2 dilution on partially premixed CH4-air flames in swirl and bluff body stabilized combustor

Aravind, S.; Gohiya, R.K.; Prakash, Ritesh; Sadanandan, Rajesh

doi:10.1016/j.proci.2020.06.153

Cited by 10 publications

(7 citation statements)

References 17 publications

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“…The flames are mainly stable above the bluff body and occur at the inner recirculation zone. It can be inferred that the influence of bluff body is greater as a consequence of the influenced flow field, which is in agreement with Aravind et al Although the structure of flames close to rich blowout is similar to those under fuel-lean conditions, the flame is brighter, as shown in Figure c. This phenomenon is probably due to the reduction in air flow, which results in the recirculated zone being close to the bluff body.…”

Section: Resultsmentioning

confidence: 99%

“…This phenomenon is probably caused by the structure of the combustor. Due to the bluff body and swirler, this kind of combustor presents great stability under fuel-lean condition and results in the small variation of OH* value. ,, For NH 2 * radiance, the maximum NH 2 * radiance is more sensitive to the change of the equivalence ratio when E NH 3 is higher than 60%. NH 2 is mainly generated through ammonia-related reactions, e.g., NH 3 + OH = NH 2 + H 2 O and NH 3 + O = NH 2 + OH .…”

Section: Resultsmentioning

confidence: 99%

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Blow-Off Limits, Flame Structure, and Emission Characteristics of Lean Partially Premixed Swirl-Stabilized Flames with NH₃/CH₄

Lai,

Chen,

Zhang

et al. 2024

Energy Fuels

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Recently, ammonia/methane mixtures have been considered as potential alternative fuels. The present study experimentally investigates the blow-off limits, flame structure, and pollutant emission of ammonia/methane mixtures in a partially premixed swirl-stabilized burner. The effects of fuel composition and the equivalence ratio are also studied. The results show that the NH 3 /CH 4 flame can be stabilized at an equivalence ratio of 0.55. The addition of methane has a positive effect on the blow-off limits. For the chemiluminescence profile, the OH* distribution and CH* distribution of NH 3 /CH 4 flames show a similar tendency under various conditions. The peak OH* and CH* radiances monotonically decrease with increasing E NHd 3 , while the maximum NH 2 * shows an opposite trend. The influence of the equivalence ratio on OH* and CH* in the NH 3 /CH 4 flames is negligible. However, when E NHd 3 is 60%, the equivalence ratio has a significant effect on NH 2 *. In terms of pollutant emissions, the peaks of NO and NO 2 emissions are all found around an E NHd 3 of 20%. When the equivalence ratio reaches 1.0, NO and NO 2 emissions are as low as 15 and 10 mg/m 3 , respectively. At the same time, both CO and unburned NH 3 emissions increase. Therefore, further studies on the application of secondary air or improvement of the fuel injection method to improve the combustion efficiency and reduce the pollutant emissions for ammonia combustion are still needed.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Blow-Off Limits, Flame Structure, and Emission Characteristics of Lean Partially Premixed Swirl-Stabilized Flames with NH₃/CH₄

Lai,

Chen,

Zhang

et al. 2024

Energy Fuels

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“…As seen in Figure 15, while the CO level decreased in the case of dilution with

N_{2}

, it seems that there was an increase in CO level in the case of dilution with

{CO}_{2} .

[ 43,44 ] This is thought to be due to the thermal and chemical reaction interaction, as well as the shorter duration of the intermediate products in the flame zone due to the increased flow rate. [ 45,46 ]…”

Section: Resultsmentioning

confidence: 99%

“…As seen in Figure 15, while the CO level decreased in the case of dilution with N 2 , it seems that there was an increase in CO level in the case of dilution with CO 2 : [43,44] This is thought to be due to the thermal and chemical reaction interaction, as well as the shorter duration of the intermediate products in the flame zone due to the increased flow rate. [45,46] Carbon dioxide (CO 2 ) As a result of the combustion of all fuels containing carbon, carbon dioxide formation is inevitable. CO 2 (%) profiles under conventional and CDC conditions is shown in Figure 16.…”

Section: Carbon Monoxide (Co)mentioning

confidence: 99%

Colourless distributed combustion effects on a pre‐mixed coke oven gas flame

Tasdemir,

Karyeyen

2023

Can J Chem Eng

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Fuels consisting of high hydrogen concentration can be consumed under colourless distributed combustion (CDC) to suppress flashback tendency in premixed conditions. Higher NOX challenges can also be overcome through CDC. For those purposes, coke oven gas was consumed under CDC within the scope of this study. To achieve CDC, or diluents were introduced into the oxidizer so that oxygen concentration in the oxidizer would be decreased from 21% O2 to its lean blow‐off limits. Excess air ratios were determined as λ = 1.2 and λ = 1.5 along with a thermal power of 10 kW under premixed conditions. A commercial computational fluid dynamics code was used to predict temperature distribution and , CO, and emissions. 162‐step reactions created with GRI‐Mech 3.0 chemical kinetics was integrated to the eddy dissipation concept combustion model. The temperature and profiles predicted were compared with the experimental results. Consistency was achieved at ~95% for temperature profiles, and almost 100% for profiles between the measured and the predicted ones. According to the results, it is concluded that a more homogeneous temperature distribution with the ~21% decrease in the maximum temperature was observed, and there was about 96% decrease in level. It was also demonstrated that using as a diluent is more effective in terms of temperature distribution over the combustor and reduction, while dilution with is more effective in terms about 70% in decrease on CO.

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“…Biogas combustion can achieve lower NOX emissions but with higher CO and UHC emissions, depending on the operating conditions. Swirl flames are particularly effective in reducing NOX emissions from biogas combustion, but they also increase CO and UHC emissions compared to pure methane flames [12]. Therefore, biogas may be a viable alternative fuel for gas turbine combustors if the CO emissions can be controlled adequately [13].…”

Section: Introductionmentioning

confidence: 99%

Effect of Inner Swirl Angle on Flame Stability of a Double-Swirl Burner with Biogas-Methane Co-Firing

Ahmed M. Abdulnaim,

Ahmed H. Elkholy,

Mohamed A. Elmously

et al. 2023

Proceedings of International Exchange and Innovation Conference on Engineering &Amp; Sciences (IEICES)

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This paper studies how the inner swirl angle affects the flame stability of a double-swirl burner with biogasmethane co-firing. Biogas is a renewable fuel that is produced from organic waste by anaerobic digestion, it can be mixed with methane as an act to save methane fuel as well reduce CO2 emissions. However, biogas has combustion challenges due to its high CO2 content. The double-swirl burner is a technology that can improve combustion performance and reduce nitrogen oxide emissions. This study investigates different inner swirl angles with various CO2 fractions in biogas and assesses their effects on flame stability and flame appearance. The paper finds that a higher CO2 fraction and inner swirl angle make the flame less stable and requires more fuel, and also changes the flame shape. The paper gives insights into improving the double-swirl burner for biogas-methane co-firing.

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Effects of CO2 dilution on partially premixed CH4-air flames in swirl and bluff body stabilized combustor

Cited by 10 publications

References 17 publications

Blow-Off Limits, Flame Structure, and Emission Characteristics of Lean Partially Premixed Swirl-Stabilized Flames with NH₃/CH₄

Blow-Off Limits, Flame Structure, and Emission Characteristics of Lean Partially Premixed Swirl-Stabilized Flames with NH₃/CH₄

Colourless distributed combustion effects on a pre‐mixed coke oven gas flame

Effect of Inner Swirl Angle on Flame Stability of a Double-Swirl Burner with Biogas-Methane Co-Firing

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Effects of CO2 dilution on partially premixed CH4-air flames in swirl and bluff body stabilized combustor

Cited by 10 publications

References 17 publications

Blow-Off Limits, Flame Structure, and Emission Characteristics of Lean Partially Premixed Swirl-Stabilized Flames with NH3/CH4

Blow-Off Limits, Flame Structure, and Emission Characteristics of Lean Partially Premixed Swirl-Stabilized Flames with NH3/CH4

Colourless distributed combustion effects on a pre‐mixed coke oven gas flame

Effect of Inner Swirl Angle on Flame Stability of a Double-Swirl Burner with Biogas-Methane Co-Firing

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Product

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Blow-Off Limits, Flame Structure, and Emission Characteristics of Lean Partially Premixed Swirl-Stabilized Flames with NH₃/CH₄

Blow-Off Limits, Flame Structure, and Emission Characteristics of Lean Partially Premixed Swirl-Stabilized Flames with NH₃/CH₄