An experimental and modeling study of ammonia with enriched oxygen content and ammonia/hydrogen laminar flame speed at elevated pressure and temperature

Currently, new concepts for power generation are discussed, as a response to combat global warming due to CO2 emissions stemming from the combustion of fossil fuels. These concepts include new, low-carbon fuels as well as centralized and decentralized solutions. Thus, a more diverse range of fuel supplies will be used, with (biogenic) low-caloric gases such as syngas and coke oven gas (COG) among them. Typical for theses low-caloric gases is the amount of hydrogen, with a share of 50% and even higher. However, hydrogen mixtures have a higher reactivity than natural gas (NG) mixtures, burned mostly in today's gas turbine combustors. Therefore, in the present work, a combined experimental and modeling study of nitrogen-enriched hydrogen–air mixtures, some of them with a share of methane, to be representative for COG, will be discussed focusing on laminar flame speed data as one of the major combustion properties. Measurements were performed in a burner test rig at ambient pressure and at a preheat temperature T0 of 373 K. Flames were stabilized at fuel–air ratios between about φ = 0.5–2.0 depending on the specific fuel–air mixture. This database was used for the validation of four chemical kinetic reaction models, including an in-house one, and by referring to hydrogen-enriched NG mixtures. The measured laminar flame speed data of nitrogen-enriched methane–hydrogen–air mixtures are much smaller than the ones of nitrogen-enriched hydrogen–air mixtures. The grade of agreement between measured and predicted data depends on the type of flames and the type of reaction model as well as of the fuel–air ratio: a good agreement was found in the fuel lean and slightly fuel-rich regime; a large underprediction of the measured data exists at very fuel-rich ratios (φ > 1.4). From the results of the present work, it is obvious that further investigations should focus on highly nitrogen-enriched methane–air mixtures, in particular for very high fuel–air ratio (φ > 1.4). This knowledge will contribute to a more efficient and a more reliable use of low-caloric gases for power generation.

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Selected combustion parameters of biogas at elevated pressure–temperature conditions

Combustion Engines ◽

10.19206/ce-117050 ◽

2012 ◽

Vol 148 (1) ◽

pp. 40-47

Author(s):

Stanisław SZWAJA ◽

Wojciech TUTAK ◽

Karol GRAB-ROGALIŃSKI ◽

Arkadiusz JAMROZIK ◽

Arkadiusz KOCISZEWSKI

Keyword(s):

Carbon Dioxide ◽

Ignition Delay ◽

Combustion Temperature ◽

Laminar Flame ◽

Engine Performance ◽

Elevated Pressure ◽

Flame Speed ◽

Methane Content ◽

Laminar Flame Speed ◽

Adiabatic Combustion Temperature

Results from tests conducted in several RTD centers lead to conclusion that biogas as a potential fuel for the internal combustion (IC) spark ignited (SI) engine features with its satisfactory combustion predisposition causing smooth engine run without accidental misfiring or knock events. This good predisposition is obtained due to carbon dioxide (CO2) content in the biogas. On the other hand, carbon dioxide as incombustible gas contribute to decrease in the brake power of the biogas fueled engine. To analyze mutual CO2 and CH4 content on biogas burning the combustion parameters as follows: adiabatic combustion temperature, laminar flame speed and ignition delay of biogas with various methane content were determined and presented in the paper. Additionally, these parameters for pure methane were also included in order to make comparison between each other. As computed, ignition delay, which has is strongly correlated with knock resistance, can change several times with temperature increase, but does not change remarkably with increase in methane content. Adiabatic combustion temperature does not also ought to influence on engine performance or increase in engine cooling and exhaust losses due to its insignificant changes. The largest change was observed in laminar flame speed, that can influence on development of the first premixed combustion phase.

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Laminar Flame Speed of Hydrocarbon Fuels with Preheat and Low Oxygen Content

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition ◽

10.2514/6.2010-778 ◽

2010 ◽

Cited By ~ 1

Author(s):

Yash Kochar ◽

Sarah Vaden ◽

Timothy Lieuwen ◽

Jerry Seitzman

Keyword(s):

Oxygen Content ◽

Laminar Flame ◽

Flame Speed ◽

Hydrocarbon Fuels ◽

Laminar Flame Speed ◽

Low Oxygen

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Laminar Flame Speed Measurements and Modeling of Alkane Blends at Elevated Pressures With Various Diluents

Volume 2: Combustion, Fuels and Emissions, Parts A and B ◽

10.1115/gt2011-45122 ◽

2011 ◽

Cited By ~ 17

Author(s):

Yash Kochar ◽

Jerry Seitzman ◽

Timothy Lieuwen ◽

Wayne Metcalfe ◽

Sine´ad Burke ◽

...

Keyword(s):

Chemical Kinetics ◽

Laminar Flame ◽

Initial Pressure ◽

Elevated Pressure ◽

Flame Speed ◽

Laminar Flame Speed ◽

Fuel Blends ◽

Elevated Pressures ◽

Flame Method ◽

The Stability

Laminar flame speeds at elevated pressure for methane-based fuel blends are important for refining the chemical kinetics that are relevant at engine conditions. The present paper builds on earlier measurements and modeling by the authors by extending the validity of a chemical kinetics mechanism to laminar flame speed measurements obtained in mixtures containing significant levels of helium. Such mixtures increase the stability of the experimental flames at elevated pressures and extend the range of laminar flame speeds. Two experimental techniques were utilized, namely a Bunsen burner method and an expanding spherical flame method. Pressures up to 10 atm were studied, and the mixtures ranged from pure methane to binary blends of CH4/C2H6 and CH4/C3H8. In the Bunsen flames, the data include elevated initial temperatures up to 650 K. There is generally good agreement between model and experiment, although some discrepancies still exist with respect to equivalence ratio for certain cases. A significant result of the present study is that the effect of mixture composition on flame speed is well captured by the mechanism over the extreme ranges of initial pressure and temperature covered herein. Similarly, the mechanism does an excellent job at modeling the effect of initial temperature for methane-based mixtures up to at least 650 K.

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A comprehensive kinetic model for dimethyl ether and dimethoxymethane oxidation and NO interaction utilizing experimental laminar flame speed measurements at elevated pressure and temperature

Combustion and Flame ◽

10.1016/j.combustflame.2020.04.016 ◽

2020 ◽

Vol 218 ◽

pp. 57-74 ◽

Cited By ~ 4

Author(s):

Krishna P. Shrestha ◽

Sven Eckart ◽

Ayman M. Elbaz ◽

Binod R. Giri ◽

Chris Fritsche ◽

...

Keyword(s):

Kinetic Model ◽

Dimethyl Ether ◽

Laminar Flame ◽

Elevated Pressure ◽

Flame Speed ◽

Laminar Flame Speed

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Experimental and Kinetic Modeling Study of Laminar Flame Speed of Dimethoxymethane and Ammonia Blends

Energy & Fuels ◽

10.1021/acs.energyfuels.0c02269 ◽

2020 ◽

Vol 34 (11) ◽

pp. 14726-14740

Author(s):

Ayman M. Elbaz ◽

Binod Raj Giri ◽

Gani Issayev ◽

Krishna P. Shrestha ◽

Fabian Mauss ◽

...

Keyword(s):

Kinetic Modeling ◽

Laminar Flame ◽

Flame Speed ◽

Laminar Flame Speed ◽

Modeling Study

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Experimental and modeling study of laminar flame speed and non-premixed counterflow ignition of n-heptane

Proceedings of the Combustion Institute ◽

10.1016/j.proci.2008.06.213 ◽

2009 ◽

Vol 32 (1) ◽

pp. 1245-1252 ◽

Cited By ~ 66

Author(s):

A.J. Smallbone ◽

W. Liu ◽

C.K. Law ◽

X.Q. You ◽

H. Wang

Keyword(s):

Laminar Flame ◽

Flame Speed ◽

Laminar Flame Speed ◽

Modeling Study

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The Influence of Diluent Gases on Combustion Properties of Natural Gas: A Combined Experimental and Modeling Study

Volume 3: Coal, Biomass and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration ◽

10.1115/gt2015-42752 ◽

2015 ◽

Cited By ~ 1

Author(s):

Jörn Ermel ◽

Sandra Richter ◽

Thomas Kick ◽

Marina Braun-Unkhoff ◽

Clemens Naumann ◽

...

Keyword(s):

Power Generation ◽

Natural Gas ◽

Laminar Flame ◽

Ambient Pressure ◽

Flame Speed ◽

Laminar Flame Speed ◽

Diverse Range ◽

Combustion Properties ◽

Modeling Study ◽

A Share

Currently, new concepts for power generation are discussed, as a response to combat global warming due to CO2 emissions stemming from the combustion of fossil fuels. These concepts include new, low-carbon fuels as well as centralized and decentralized solutions. Thus, a more diverse range of fuel supplies will be used, with (biogenic) low-caloric gases such as syngas and coke oven gas (COG) among them. Typical for theses low-caloric gases is the amount of hydrogen, with a share of 50% and even higher. However, hydrogen mixtures have a higher reactivity than natural gas (NG) mixtures, burned mostly in today’s gas turbine combustors. Therefore, in the present work, a combined experimental and modeling study of nitrogen-enriched hydrogen-air mixtures, some of them with a share of methane, to be representative for COG, will be discussed focusing on laminar flame speed data Su as one of the major combustion properties. Measurements were performed in a burner test rig at ambient pressure and at a preheat temperature T0 of 373 K. Flames were stabilized at fuel-air ratios between about φ = 0.5–2.1, depending on the specific fuel-air mixture. This database was used for the validation of four chemical kinetic reaction models, including an in-house one, and by referring to hydrogen-enriched natural gas mixtures. The measured laminar flame speed data of nitrogen-enriched methane-hydrogen-air mixtures are much smaller than the ones of nitrogen-enriched hydrogen-air mixtures. The grade of agreement between measured and predicted data depends on the type of flames and the type of reaction model as well as of the fuel-air ratio: good agreement was found in the fuel lean and slightly fuel rich regime; a large underprediction of the measured data exists at very fuel-rich ratios (φ > 1.4). From the results of the present work, it is obvious that further investigations should focus on highly nitrogen-enriched methane-air mixtures, in particular for very high fuel-air ratio (φ > 1.4). This knowledge will contribute to a more efficient and a more reliable use of low-caloric gases for power generation.

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