scholarly journals The Equivalent Effect of Initial Condition Coupling on the Laminar Burning Velocity of Natural Gas Diluted by CO2

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 809
Author(s):  
Xueshun Wu ◽  
Peng Wang ◽  
Zhennan Zhu ◽  
Yunshou Qian ◽  
Wenbin Yu ◽  
...  
Keyword(s):  
Dilution Rate ◽  
Initial Temperature ◽  
Coupling Effect ◽  
Burning Velocity ◽  
Initial Pressure ◽  
Rate Of Change ◽  
Equal Weight ◽  
Initial Condition ◽  
Laminar Burning Velocity ◽  
Equivalent Effect

Initial temperature has a promoting effect on laminar burning velocity, while initial pressure and dilution rate have an inhibitory effect on laminar burning velocity. Equal laminar burning velocities can be obtained by initial condition coupling with different temperatures, pressures and dilution rates. This paper analysed the equivalent distribution pattern of laminar burning velocity and the variation pattern of an equal weight curve using the coupling effect of the initial pressure (0.1–0.3 MPa), initial temperature (323–423 K) and dilution rate (0–16%). The results show that, as the initial temperature increases, the initial pressure decreases and the dilution rate decreases, the rate of change in laminar burning velocity increases. The equivalent effect of initial condition coupling can obtain equal laminar burning velocity with an dilution rate increase (or decrease) of 2% and an initial temperature increase (or decrease) of 29 K. Moreover, the increase in equivalence ratio leads to the rate of change in laminar burning velocity first increasing and then decreasing, while the increases in dilution rate and initial pressure make the rate of change in laminar burning velocity gradually decrease and the increase in initial temperature makes the rate of change in laminar burning velocity gradually increase. The area of the region, where the initial temperature influence weight is larger, gradually decreases as the dilution rate increases, and the rate of decrease gradually decreases.

scholarly journals The Effect of Initial Conditions on the Laminar Burning Characteristics of Natural Gas Diluted by CO2

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2892 ◽  
Author(s):  
Zhiqiang Han ◽  
Zhennan Zhu ◽  
Peng Wang ◽  
Kun Liang ◽  
Zinong Zuo ◽  
...  
Keyword(s):  
Natural Gas ◽  
Dilution Rate ◽  
Initial Temperature ◽  
Initial Conditions ◽  
Burning Velocity ◽  
Initial Pressure ◽  
Chemical Kinetic ◽  
Laminar Burning Velocity ◽  
Flame Instability ◽  
Highly Correlated

The initial conditions such as temperature, pressure and dilution rate can have an effect on the laminar burning velocity of natural gas. It is acknowledged that there is an equivalent effect on the laminar burning velocity between any two initial conditions. The effects of initial temperatures (323 K–423 K), initial pressures (0.1 MPa–0.3 MPa) and dilution rate (0–16%, CO2 as diluent gas) on the laminar burning velocity and the flame instability were investigated at a series of equivalence ratios (0.7–1.2) in a constant volume chamber. A chemical kinetic simulation was also conducted to calculate the laminar burning velocity and essential radicals’ concentrations under the same initial conditions. The results show that the laminar burning velocity of natural gas increases with initial temperature but decreases with initial pressure and dilution rate. The maximum concentrations of H, O and OH increase with initial temperature but decrease with initial pressure and dilution rate. Laminar burning velocity is highly correlated with the sum of the maximum concentration of H and OH.

Laminar burning velocity of microalgae oil/RP-3 premixed flame at elevated initial temperature and pressure

Fuel ◽  
2022 ◽  
Vol 309 ◽  
pp. 122081
Author(s):  
Yu Liu ◽  
Wu Gu ◽  
Jinduo Wang ◽  
Hongan Ma ◽  
Nanhang Dong ◽  
...  
Keyword(s):  
Initial Temperature ◽  
Burning Velocity ◽  
Premixed Flame ◽  
Laminar Burning Velocity ◽  
Microalgae Oil ◽  
Temperature And Pressure

scholarly journals EXPERIMENTAL DETERMINATION OF LAMINAR BURNING VELOCITY OF BIOGAS AT PRESSURES UP TO 5 BAR

2018 ◽  
Vol 17 (2) ◽  
pp. 03
Author(s):  
L. Pizzuti ◽  
C. A. Martins ◽  
L. R. Santos
Keyword(s):  
Equivalence Ratio ◽  
Burning Velocity ◽  
Initial Pressure ◽  
Experimental Setup ◽  
Laminar Burning Velocity ◽  
Gaseous Mixtures ◽  
Experimental Procedure ◽  
Constant Volume Combustion Chamber ◽  
Percentage Standard Deviation

This paper presents a very detailed description of a new cylindrical constant volume combustion chamber designed for laminar burning velocity determination of gaseous mixtures at ambient temperature and initial pressure up to 6 bar. The experimental setup, the experimental procedure and the determination of the range of flame radius for laminar burning determination are all described in details. The laminar burning velocity of twelve synthetic biogas mixtures has been studied. Initial pressure varying between 1 and 5 bar, equivalence ratios, f, between 0.7 and 1.1 and percentage dilution, with a mixture of CO2 and N2, between 35 and 55% have been considered. Five experiments were run for each mixture providing a maximum percentage standard deviation of 8.11%. However, for two third of the mixtures this value is lower than 3.55%. A comparison with simulation using PREMIX for both GRI-Mech 3.0 and San Diego mechanisms has provided closer agreement for mixtures with equivalence ratio closer to stoichiometry whereas for f = 0.7 the deviation is larger than 15% for all pressures. Mixtures with lower equivalence ratio, higher dilution percentage and higher initial pressure presents the lower values of laminar burning velocity.

scholarly journals Laminar Burning Velocity and Flammability Characteristics of Biogas in Spark Ignited Premix Combustion at Reduced Pressure

2013 ◽  
Vol 376 ◽  
pp. 79-85 ◽  
Author(s):  
Willyanto Anggono ◽  
I.N.G. Wardana ◽  
M. Lawes ◽  
K.J. Hughes ◽  
Slamet Wahyudi ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Pressure ◽  
Burning Velocity ◽  
Initial Pressure ◽  
Dilution Effect ◽  
Laminar Burning Velocity ◽  
Fundamental Study ◽  
Reduced Pressure ◽  
Premix Combustion ◽  
Flammability Characteristics

Biogas as a “Powergas” is an alternative fuel produced in digestion facilities, that is sustainable and renewable. Based on chemical analysis, the composition of the biogas produced in East Java is 66.4% methane, 30.6% carbon dioxide and 3% nitrogen. Methane is a flammable gas, whereas, nitrogen and carbon dioxide are inhibitors. Given it has a different composition to traditional fuels, a fundamental study of biogas flame propagation characteristics is desirable to quantify this important fuel property. Spherically expanding flames propagating at constant pressure are employed to measure the laminar burning velocity and flammability characteristics as mixture function of the mixture composition. These important parameters were measured using a photographic technique in a high pressure fan-stirred bomb. The characteristics of biogas-air flames were initially studied at reduced pressure and at various equivalence ratios from the lower flammable limit to the upper flammable limit. The results were compared with those from biogas-air flames at atmospheric pressure. Based on this experimental investigation, the laminar burning velocities of biogas-air mixtures at reduced pressure were 0.218 m/s for ϕ=0.75, 0.246 m/s for ϕ=0.80 and 0.269 m/s for ϕ=0.85 respectively and only for these biogas mixtures propagated at reduced pressure. At the same equivalence ratio (ϕ), the laminar burning velocities of the biogas-air mixtures at reduced pressure are higher than those at atmospheric pressure. The flammable region of biogas became narrower by reducing initial pressure. The dilution effect is stronger at reduced pressure. Therefore, the flammable composition mixture areas of biogas-air mixtures are more limited at reduced pressure than those at atmospheric pressure.

scholarly journals The Temperature and Pressure Dependencies of Propagation Characteris-tics for Premixed Laminar Ethanol-Air Flames

2012 ◽  
Vol 6 (1) ◽  
pp. 55-64 ◽  
Author(s):  
S. Y. Liao ◽  
D. L. Zhong ◽  
C. Yang ◽  
X. B. Pan ◽  
C. Yuan ◽  
...  
Keyword(s):  
Equivalence Ratio ◽  
Initial Temperature ◽  
Burning Velocity ◽  
Initial Mixture ◽  
Spark Ignition ◽  
Laminar Burning Velocity ◽  
Propagation Characteristics ◽  
Activation Temperature ◽  
Temperature And Pressure ◽  
Premixed Laminar

Laminar burning velocity is strongly dependent on mixture characteristics, e.g. initial temperature, pressure and equivalence ratio. In this work, spherically expanding laminar premixed flames, freely propagating from a spark ignition source in initially quiescent ethanol-air mixtures, have been imaged and then the laminar burning velocities were obtained at initial temperatures of 358 K to 500K, pressure of 0.1 to 0.2 MPa and equivalence ratio of 0.7 to 1.4. The measured re-sults and literature data on ethanol laminar burning velocities were accumulated, to analyze the effects of initial tempera-ture and pressure on the propagation characteristics of laminar ethanol-air flames. A correlation in the form of ul=ulo(Tu/Tu0)αT (Pu/Pu0)βP , and validated over much wide temperature, pressure and equivalence ratio ranges. The global activation temperatures were determined in terms of the laminar burning mass flux for ethanol-air flames. And the Zel’dovich numbers were estimated as well. The dependencies of global activation temperature and Zel’dovich number on initial mixture pressure, temperature and equivalence ratio were explored. Additionally, an alterna-tive correlation of laminar burning velocities, from the view of theoretical arguments, was proposed on the basis of the de-termined ethanol-air laminar mass burning flux. Good agreements were obtained in its comparison with the literature data.

Effects of CO content on laminar burning velocity of typical syngas by heat flux method and kinetic modeling

2014 ◽  
Vol 39 (17) ◽  
pp. 9534-9544 ◽  
Author(s):  
Yong He ◽  
Zhihua Wang ◽  
Wubin Weng ◽  
Yanqun Zhu ◽  
Junhu Zhou ◽  
...  
Keyword(s):  
Heat Flux ◽  
Kinetic Modeling ◽  
Burning Velocity ◽  
Laminar Burning Velocity ◽  
Flux Method

scholarly journals Laminar Burning Velocity of Biogas-Containing Mixtures. A Literature Review

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 996
Author(s):  
Venera Giurcan ◽  
Codina Movileanu ◽  
Adina Magdalena Musuc ◽  
Maria Mitu
Keyword(s):  
Gas Turbines ◽  
Internal Combustion Engines ◽  
Fossil Fuels ◽  
Combustion Engine ◽  
Burning Velocity ◽  
Internal Combustion ◽  
Electricity Production ◽  
Engine Fuel ◽  
Laminar Burning Velocity ◽  
Waste Products

Currently, the use of fossil fuels is very high and existing nature reserves are rapidly depleted. Therefore, researchers are turning their attention to find renewable fuels that have a low impact on the environment, to replace these fossil fuels. Biogas is a low-cost alternative, sustainable, renewable fuel existing worldwide. It can be produced by decomposition of vegetation or waste products of human and animal biological activity. This process is performed by microorganisms (such as methanogens and sulfate-reducing bacteria) by anaerobic digestion. Biogas can serve as a basis for heat and electricity production used for domestic heating and cooking. It can be also used to feed internal combustion engines, gas turbines, fuel cells, or cogeneration systems. In this paper, a comprehensive literature study regarding the laminar burning velocity of biogas-containing mixtures is presented. This study aims to characterize the use of biogas as IC (internal combustion) engine fuel, and to develop efficient safety recommendations and to predict and reduce the risk of fires and accidental explosions caused by biogas.

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