Effects of H2 or CO2 addition, equivalence ratio, and turbulent straining on turbulent burning velocities for lean premixed methane combustion

Shy, S.S.; Chen, Y.C.; Yang, Ching Hao; Liu, C.C.; Huang, Chun‐Kai

doi:10.1016/j.combustflame.2008.03.014

Cited by 66 publications

(31 citation statements)

References 26 publications

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“…Addition of H 2 to the mixture leads to an increased reactivity towards CH 4 oxidation: mix 1/2/3 (mixtures with increasing H 2 content) showed steeper curves, with lower T 90 , by increasing the H 2 fraction, probably due to the presence of H 2 reactive radicals. [8,9,13] Moreover, the H 2 oxidation curves were shifted to lower T values compared to those of pure H 2 / air systems. This observed increase in reactivity and heat-release rate of the mixture at low T when the CH 4 fuel is en-riched with H 2 could be explained by an increase in the rate of the reaction H + HO 2 !…”

Section: Resultsmentioning

confidence: 96%

“…The addition of a small amount of H 2 leads to an extension of the lean operating limit and to an increase in the stability and reactivity of the CH 4 /air flames. [6,7] It was demonstrated that H 2 enrichment leads to a significant increase in the concentration of OH radicals, [8,9] with a consequent enhancement of the early heat release in the flame zone that causes an enhancement of the CH 4 ignition under conditions at which, otherwise, CH 4 combustion would be prone to undergo extinction. [10] Moreover, it was found that the addition of H 2 to CH 4 in ICEs can enhance their performance, particularly when operating at relatively low l ratios, [11] and reduces the CO 2 emissions.…”

Section: Introductionmentioning

confidence: 99%

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Combustion of CH₄/H₂/Air Mixtures in Catalytic Microreactors

et al. 2009

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The combustion of CH(4)/H(2)/HC mixtures in a very small space represents an alternative, innovative way to produce thermal/electrical energy. Pd/NiCrO(4) catalysts are lined on SiC monoliths via in situ solution combustion synthesis (SCS), and the monoliths are then tested by feeding CH(4), H(2), and lean CH(4)/H(2) mixtures into a lab-scale test rig at an output thermal power of 7.6 MW(th) m(-3). In all cases, the combustion temperature shifts to values lower than those observed in non-catalytic combustion. When the power density is kept constant (by adding H(2) to the gas mixture), the value of CH(4)-T(50) (the half-conversion temperature of CH(4)) decreases relative to that of pure CH(4), and the slope of the conversion curve becomes steeper. The higher the H(2) concentration is, the higher the reactivity of the mixture towards CH(4) oxidation-probably due to a higher production of H(2) reactive radicals (OH).

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Section: Resultsmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Combustion of CH₄/H₂/Air Mixtures in Catalytic Microreactors

et al. 2009

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“…A nonlinear dependence of S T on S L is shown in the bending region of the fitted curve. Shy et al [50] reported that the bending effect promoted by CO 2 addition in rich turbulent premixed flames is due to the radiative heat loss. RMS temperature fluctuation values are plotted as a function of the mean temperature in Fig.…”

Section: Mean Flame Brush Locationmentioning

confidence: 99%

Dual-pump vibrational CARS measurements of temperature and species concentrations in turbulent premixed flames with CO2 addition

Han

Satija

Kim

et al. 2017

Combustion and Flame

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a b s t r a c tA dual-pump vibrational coherent anti-Stokes Raman scattering (DPVCARS) system was applied for simultaneous temperature and species concentration measurements in jet flames on a newly developed piloted axisymmetric reactor assisted turbulent (PARAT) premixed flame burner. Turbulent lean premixed methane/air round jet flames with varying CO 2 dilution were stabilized using an annular flow of hydrogen at the flame base. Carbon dioxide was injected into the fuel stream to simulate effects of dry exhaust gas recirculation (EGR). The flames were operated at a nearly constant Reynolds number, Lewis number, and adiabatic flame temperature to minimize thermal and transport effects. Velocity boundary conditions at the burner exit were measured using particle image velocimetry. Simultaneous temperature and major species concentrations (O 2 and CO 2 ) were measured along the axial direction at the burner centerline and along the radial direction at representative axial locations above the burner. Progress variables calculated based on the temperatures were used to study the mean flame brush thickness and the turbulent burning velocity. Probability density functions (PDFs) of temperature at various locations are presented and discussed. The DPVCARS measurements provide an experimental database including temperature and turbulent burning velocity for combustion model evaluation and validation and demonstrated a strong potential for flame structure investigation with future improvement on spatial resolution and signal to noise ratio. The merits and limitations of vibrational CARS for diagnostics in turbulent premixed combustion are discussed. The results show that flames with CO 2 addition depart from the universal mean flame brush structure, while their RMS fluctuation values at an identical mean temperature collapse with the undiluted flame. The CO 2 addition increases the combustion intensity with a decrease in turbulent burning velocity when minimizing the thermal and transport effects.

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“…Calculation methods can be found in the literatures [5][6][7], Lower heating value (LHV) calculated by volume of gas of H2 is lower than CH4 so that H2 enrichment decreases the LHV of the mix ture. The addition of chemically reactive H2 raises the upper flam mability and reduces the lower flammability of the blended gas to give a wider flammability range of the mixture.…”

Section: Test Condition Matrixesmentioning

confidence: 99%

Hydrogen Enriched Combustion Testing of Siemens Industrial SGT-400 at Atmospheric Conditions

Lam

Geipel

Larfeldt

2014

Journal of Engineering for Gas Turbines and Power

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In order to further extend the turbine fuel flex capability, a test under atmospheric condi tions of a full-scale SGT-400 burner was performed to study the combustion behavior when operating on hydrogen enriched natural gas (NG). A high speed camera was in stalled in the rig to investigate the flame dynamics on different operation conditions. NOx emissions were measured for all presented conditions. The combustion system was instru mented with thermocouples on all the key locations to allow flame position monitoring and to avoid flame attachment on the hardware. Further measurements included static pressure probes to monitor combustor pressure drop. The test was conducted in a system atic matrix format to include the most important combustion parameters in order to iden tify their individual effects on the combustion behaviors. The quantity of hydrogen in natural gas, fuel split, air preheat temperature, air reference velocity and flame tempera ture were the combustion related variables studied in the presented test campaign. The volumetric hydrogen quantity could be increased to 30% maintaining stable operation for all measured conditions. Higher hydrogen contents up to 80 vol. % were reached without flash back tendency. A glowing spark igniter prevented testing at even higher hydrogen contents. Hydrogen enriched gas showed higher NOx emissions and improved blowout limit. Hydrogen blending in the fuel also reduced the combustor pressure drop, lowered the prechamber temperature and raised the pilot tip temperature.

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Effects of H2 or CO2 addition, equivalence ratio, and turbulent straining on turbulent burning velocities for lean premixed methane combustion

Cited by 66 publications

References 26 publications

Combustion of CH₄/H₂/Air Mixtures in Catalytic Microreactors

Combustion of CH₄/H₂/Air Mixtures in Catalytic Microreactors

Dual-pump vibrational CARS measurements of temperature and species concentrations in turbulent premixed flames with CO2 addition

Hydrogen Enriched Combustion Testing of Siemens Industrial SGT-400 at Atmospheric Conditions

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Effects of H2 or CO2 addition, equivalence ratio, and turbulent straining on turbulent burning velocities for lean premixed methane combustion

Cited by 66 publications

References 26 publications

Combustion of CH4/H2/Air Mixtures in Catalytic Microreactors

Combustion of CH4/H2/Air Mixtures in Catalytic Microreactors

Dual-pump vibrational CARS measurements of temperature and species concentrations in turbulent premixed flames with CO2 addition

Hydrogen Enriched Combustion Testing of Siemens Industrial SGT-400 at Atmospheric Conditions

Contact Info

Product

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Combustion of CH₄/H₂/Air Mixtures in Catalytic Microreactors

Combustion of CH₄/H₂/Air Mixtures in Catalytic Microreactors