Development of a chemical-kinetic database for the laminar flame speed under GDI and water injection engine conditions

It is expected that, in the future, gas turbines will be operated on gaseous fuels currently unutilized. The ability to predict the range of feasible fuels, and the extent to which existing turbines must be modified to accommodate these fuels, rests on the nature of these fuels in the combustion environment. Understanding the combustion behavior is aided by investigation of syngases of similar composition. As part of an ongoing project at the Lund University Departments of Thermal Power Engineering and Combustion Physics, to investigate syngases in gas turbine combustion, the laminar flame speed of five syngases (see table) have been measured. The syngases examined are of two groups. The first gas group (A), contains blends of H2, CO and CH4, with high hydrogen content. The group A gases exhibit a maximum flame speed at an equivalence ratio of approximately 1.4, and a flame speed roughly four times that of methane. The second gas group (B) contains mixtures of CH4 and H2 diluted with CO2. Group B gases exhibit maximum flame speed at an equivalence ratio of 1, and flame speeds about 3/4 that of methane. A long tube Bunsen-type burner was used and the conical flame was visualized by Schlieren imaging. The flame speeds were measured for a range of equivalence ratios using a constrained cone half-angle method. The equivalence ratio for measurements ranged from stable lean combustion to rich combustion for room temperature (25°C) and an elevated temperature representative of a gas turbine at full load (270°C). The experimental procedure was verified by methane laminar flame speed measurement; and, experimental results were compared against numerical simulations based on GRI 3.0, Hoyerman and San Diego chemical kinetic mechanisms using the DARS v2.02 combustion modeler. On examination, all measured laminar flame speeds at room temperature were higher than values predicted by the aforementioned chemical kinetic mechanisms, with the exception of group A gases, which were lower than predicted.

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Development of a New Skeletal Chemical Kinetic Mechanism for Ethanol Reference Fuel

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4029055 ◽

2015 ◽

Vol 137 (6) ◽

Cited By ~ 2

Author(s):

O. Samimi Abianeh

Keyword(s):

Ignition Delay ◽

Laminar Flame ◽

Kinetic Mechanism ◽

Chemical Kinetic ◽

Flame Speed ◽

Combustion Mechanism ◽

Laminar Flame Speed ◽

Surrogate Fuels ◽

Chemical Kinetic Mechanism ◽

Fuel Surrogates

A new skeletal chemical kinetic mechanism of ethanol reference fuel (including ethanol, iso-octane, n-heptane, and toluene combustion mechanisms) consisting of 62 species and 194 reactions is developed for oxidation and combustion of gasoline blend surrogate fuels. The skeletal ethanol chemical kinetic mechanism is added to the toluene reference fuel (TRF) mechanism (including iso-octane, n-heptane, and toluene combustion mechanisms) using reaction paths and semidecoupling model. The ignition delay and laminar flame speed of the new combustion mechanism were modeled by using several fuel surrogates at different pressures, temperatures, and equivalence ratios. The skeletal chemical kinetic mechanism ignition delay and laminar flame speed are validated by comparison to the available experimental data of the shock tube and plate burner. The results indicate that satisfactory agreement between predictions and experimental measurements are achieved.

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Development of a Novel Machine Learning Methodology for the Generation of a Gasoline Surrogate Laminar Flame Speed Database under Water Injection Engine Conditions

SAE International Journal of Fuels and Lubricants ◽

10.4271/04-13-01-0001 ◽

2019 ◽

Vol 13 (1) ◽

Cited By ~ 1

Author(s):

Leonardo Pulga ◽

Gian Marco Bianchi ◽

Matteo Ricci ◽

Giulio Cazzoli ◽

Claudio Forte

Keyword(s):

Machine Learning ◽

Laminar Flame ◽

Water Injection ◽

Flame Speed ◽

Laminar Flame Speed

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Laminar Flame Speed Measurements of Synthetic Gas Blends With Hydrocarbon Impurities

Volume 4A: Combustion, Fuels and Emissions ◽

10.1115/gt2015-42905 ◽

2015 ◽

Author(s):

Charles L. Keesee ◽

Eric L. Petersen ◽

Kuiwen Zhang ◽

Henry J. Curran

Keyword(s):

Laminar Flame ◽

Initial Conditions ◽

Chemical Kinetic ◽

Flame Speed ◽

Laminar Flame Speed ◽

Coal Syngas ◽

Chemical Kinetic Model ◽

Wide Range ◽

Synthetic Gas ◽

Fuel Mixtures

New Laminar Flame Speed measurements have been taken for a wide range of syngas mixtures containing hydrocarbon impurities. These experiments began with two baseline syngas mixtures. The first of these baseline mixtures was a bio-syngas with a 50/50 H2/CO split, and the second baseline mixture was a coal syngas with a 40/60 H2/CO split. Experiments were conducted over a range of equivalence ratios from ϕ = 0.5 to 3 at initial conditions of 1 atm and 300 K. Upon completion of the baseline experiments, two different hydrocarbons were added to the fuel mixtures at levels ranging from 0.8 to 15% by volume, keeping the H2/CO ratio locked for the bio-syngas and coal syngas mixtures. The addition of these light hydrocarbons, namely CH4 and C2H6, had been shown in recent calculations by the authors to have significant impacts on the laminar flame speed, and the present experiments validated the suspected trends. For example, a 7% addition of methane to the coal-syngas blend decreased the peak flame speed by about 25% and shifted it from ϕ = 2.2 to a leaner value near ϕ = 1.5. Also, the addition of ethane at 1.7% reduced the mixture flame speed more than a similar addition of methane (1.6%). In general, the authors’ chemical kinetic model over predicted the laminar flame speed by about 10–20% for the mixtures containing the hydrocarbons. The decrease in laminar flame speed with the addition of the hydrocarbons can be explained by the increased importance of the inhibiting reaction CH3 + H (+M) ↔ CH4 (+M), which also explains the enhanced effect of C2H6 compared to CH4, where the former produces more CH3 radicals, particularly at fuel rich conditions.

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An experimental and chemical kinetic modeling study of 1,3-butadiene combustion: Ignition delay time and laminar flame speed measurements

Combustion and Flame ◽

10.1016/j.combustflame.2018.08.006 ◽

2018 ◽

Vol 197 ◽

pp. 423-438 ◽

Cited By ~ 138

Author(s):

Chong-Wen Zhou ◽

Yang Li ◽

Ultan Burke ◽

Colin Banyon ◽

Kieran P. Somers ◽

...

Keyword(s):

Kinetic Modeling ◽

Ignition Delay ◽

Delay Time ◽

Ignition Delay Time ◽

Laminar Flame ◽

Chemical Kinetic ◽

Flame Speed ◽

Laminar Flame Speed ◽

Modeling Study

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A Numerical Study on the Reactivity of Biogas/Reformed-Gas/Air and Methane/Reformed-Gas/Air Mixtures at Gas Turbine Relevant Conditions

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

10.1115/gt2016-56655 ◽

2016 ◽

Cited By ~ 3

Author(s):

Pablo Diaz Gomez Maqueo ◽

Philippe Versailles ◽

Gilles Bourque ◽

Jeffrey M. Bergthorson

Keyword(s):

Gas Turbine ◽

Laminar Flame ◽

Numerical Study ◽

Flame Temperature ◽

Flame Speed ◽

Flame Stability ◽

Laminar Flame Speed ◽

Fuel Reforming ◽

Numerical Work ◽

Chemical Effects

This study investigates the increase in methane and biogas flame reactivity enabled by the addition of syngas produced through fuel reforming. To isolate thermodynamic and chemical effects on the reactivity of the mixture, the burner simulations are performed with a constant adiabatic flame temperature of 1800 K. Compositions and temperatures are calculated with the chemical equilibrium solver of CANTERA® and the reactivity of the mixture is quantified using the adiabatic, freely-propagating premixed flame, and perfectly-stirred reactors of the CHEMKIN-Pro® software package. The results show that the produced syngas has a content of up to 30 % H2 with a temperature up to 950 K. When added to the fuel, it increases the laminar flame speed while maintaining a burning temperature of 1800 K. Even when cooled to 300 K, the laminar flame speed increases up to 30 % from the baseline of pure biogas. Hence, a system can be developed that controls and improves biogas flame stability under low reactivity conditions by varying the fraction of added syngas to the mixture. This motivates future experimental work on reforming technologies coupled with gas turbine exhausts to validate this numerical work.

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