Experimental and kinetic studies of the effect of CO2 dilution on laminar premixed n-heptane/air flames

Li, Gesheng; Zhou, Mengni; Zhang, Zunhua; Liang, Junjie; Ding, Haiqi

doi:10.1016/j.fuel.2018.04.116

Cited by 39 publications

(8 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The flame temperature has a prevailing influence on S L o , as discussed in previous studies . Molar fractions of active radicals such as H and OH can also reveal the nature of S L o .…”

Section: Resultsmentioning

confidence: 62%

“…Another feature related to flame appearance and stability is the decrease in the hydrodynamic flame instability with increasing CO 2 dilution ratios. The hydrodynamic flame instability depends on the flame’s thermal expansion (σ) and the laminar flame’s thickness (δ) . The laminar flame’s thickness can be evaluated as δ = ( T u – T b )/(d T /d x ) max , where T u and T b are the unburned and burned gas temperatures of the mixture, respectively; here, (d T /d x ) max is the maximum temperature gradient .…”

Section: Resultsmentioning

confidence: 99%

“…The hydrodynamic flame instability depends on the flame’s thermal expansion (σ) and the laminar flame’s thickness (δ) . The laminar flame’s thickness can be evaluated as δ = ( T u – T b )/(d T /d x ) max , where T u and T b are the unburned and burned gas temperatures of the mixture, respectively; here, (d T /d x ) max is the maximum temperature gradient . The Chemkin simulation results (Aramco 1.3) of one-dimensional planar flames were used to determine (d T /d x ) max .…”

Section: Resultsmentioning

confidence: 99%

“…34 The laminar flame's thickness can be evaluated as δ = (T u − T b )/(dT/dx) max , where T u and T b are the unburned and burned gas temperatures of the mixture, respectively; here, (dT/dx) max is the maximum temperature gradient. 34 The Chemkin simulation results (Aramco 1.3) of one-dimensional planar flames were used to determine (dT/dx) max . As stated earlier, the thermal expansion is based on the ratio of the unburned density to the burned density of the mixture.…”

Section: Chemical Kinetic Simulationsmentioning

confidence: 99%

“…The flame temperature has a prevailing influence on S L o , as discussed in previous studies. 34 Molar fractions of active radicals such as H and OH can also reveal the nature of S L o . Figure 17a shows molar fractions of H and OH at 300 K and 1 and 5 bar pressure in the presence of CO 2 and FCO 2 .…”

Section: Chemical Kinetic Simulationsmentioning

confidence: 99%

See 4 more Smart Citations

Effect of CO₂ Dilution on Methane/Air Flames at Elevated Pressures: An Experimental and Modeling Study

et al. 2021

View full text Add to dashboard Cite

This study reports experimental and kinetic modeling results on the effects of CO2 dilution on laminar premixed methane/air flames, based on spherically propagating flames and one-dimensional adiabatic planar flame simulations, at elevated pressure. The laminar burning velocities of air mixtures with CH4 and CO2 at different dilution ratios were measured. In order to have a comprehensive understanding of the effects of CO2 dilution both chemically and physically, sensitivity analysis, chemical reaction rate analysis, and mole fraction analysis of active radicals were carried out using the Aramco 1.3 kinetic mechanism. The chemical impact of the addition of CO2 was segregated from its physical effects using fictitious species, FCO2 with the same thermochemical and transport characteristics as CO2, but does not participate in any chemical reactions. The CO2 dilution percentage varied was from 0 to 70% (by volume) to measure S L o at 300 K, 1 and 5 bar, and equivalence ratios (Φ) of 0.6 to 1.4. Results show that increasing CO2 dilution ratio decreases the S L o of these CH4/CO2/air mixtures. The results simulated using Aramco 1.3 illustrate that the chemical effect is less important at elevated pressure than at ambient pressure. The H and OH radical reduction rates are remarkably reduced at elevated pressure, where H radicals are primarily controlling the combustion. Elementary reactions with a negative sensitivity coefficient exhibit higher sensitivity toward pressure compared to the dilution effect, while elementary reactions with a positive sensitivity coefficient were equally sensitive to both pressure and dilution effects. The increase in initial pressure suppresses the peak net reaction rates for all the elementary reactions, with increasing CO2 concentration.

show abstract

“…The flame temperature has a prevailing influence on S L o , as discussed in previous studies . Molar fractions of active radicals such as H and OH can also reveal the nature of S L o .…”

Section: Resultsmentioning

confidence: 62%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Chemical Kinetic Simulationsmentioning

confidence: 99%

Section: Chemical Kinetic Simulationsmentioning

confidence: 99%

See 3 more Smart Citations

Effect of CO₂ Dilution on Methane/Air Flames at Elevated Pressures: An Experimental and Modeling Study

et al. 2021

View full text Add to dashboard Cite

show abstract

On the Stability and Characteristics of Biogas/Methane/Air Flames Fired by a Double Swirl Burner

Abdulnaim

Elkholy

Elmously

et al. 2023

Flow Turbulence Combust

View full text Add to dashboard Cite

CO 2 -diluted methane fuel is relevant to biogas combustion applications. Despite its poor heating value and low reactivity, which limit its practical applicability, biogas gains popularity as a renewable fuel.However, implementing it in combustion systems requires either modifying or replacing the existing burners. This study investigates the stability, temperature eld, and pollutant emissions of CH 4 /CO 2 /airpremixed ames red by a double-swirl burner. A CH 4 /air mixture of equivalence ratio, Φ out was used in the outer stream, while a CH 4 /CO 2 /air mixture was supplied to the inner stream. The CO 2 mole fraction, 𝒳 CO 2 , in the inner fuel blend varied from 0 to 0.4 for various inner stream equivalence ratios, Φ in . The stability diagram of these ames was mapped in terms of Φ in verses 𝒳 CO 2 for a xed Φ out . Based on the stability map, the in ame temperature eld was investigated for six ames.Increasing the %CO 2 in the biogas modi es the stability map by increasing the inner stream lean blow-off limits. However, increasing Φ out sustains the ame stability, while reducing the CO 2 increases the overall ame below off equivalence ratio. Flame size growth with increasing 𝒳 CO 2 requires a longer residence time for e cient combustion. The addition of CO 2 physically and chemically affects the thermal ame structure, and hence the pollutant emissions. In this burner, ultra-low NO X emission was reported, while an increase in the CO and UHC, with increasing 𝒳 CO 2 was observed. However, the results show that, for a given 𝒳 CO 2 , controlling Φ in and Φ out could reduce CO and UHC emissions.

show abstract

Analysis of research trends on hydrogen explosion by bibliometric approach

Gong,

Guan,

Dong

et al. 2023

Environ Sci Pollut Res

View full text Add to dashboard Cite

Experimental and kinetic studies of the effect of CO2 dilution on laminar premixed n-heptane/air flames

Cited by 39 publications

References 42 publications

Effect of CO₂ Dilution on Methane/Air Flames at Elevated Pressures: An Experimental and Modeling Study

Effect of CO₂ Dilution on Methane/Air Flames at Elevated Pressures: An Experimental and Modeling Study

On the Stability and Characteristics of Biogas/Methane/Air Flames Fired by a Double Swirl Burner

Analysis of research trends on hydrogen explosion by bibliometric approach

Contact Info

Product

Resources

About

Experimental and kinetic studies of the effect of CO2 dilution on laminar premixed n-heptane/air flames

Cited by 39 publications

References 42 publications

Effect of CO2 Dilution on Methane/Air Flames at Elevated Pressures: An Experimental and Modeling Study

Effect of CO2 Dilution on Methane/Air Flames at Elevated Pressures: An Experimental and Modeling Study

On the Stability and Characteristics of Biogas/Methane/Air Flames Fired by a Double Swirl Burner

Analysis of research trends on hydrogen explosion by bibliometric approach

Contact Info

Product

Resources

About

Effect of CO₂ Dilution on Methane/Air Flames at Elevated Pressures: An Experimental and Modeling Study

Effect of CO₂ Dilution on Methane/Air Flames at Elevated Pressures: An Experimental and Modeling Study