Analysis of LPG diffusion flame in tube type burner

2019 ◽  
Vol 13 (3) ◽  
pp. 5278-5293
Author(s):  
Vipul Patel ◽  
Rupesh Shah
Keyword(s):  
Diffusion Flame ◽  
Emission Characteristic ◽  
Flame Stability ◽  
Liquefied Petroleum Gas ◽  
Air Velocity ◽  
Length Fraction ◽  
Low Emission ◽  
Tube Type ◽  
Stability Limits ◽  
Co Emission

The present research aims to analyse diffusion flame in a tube type burner with Liquefied petroleum gas (LPG) as a fuel. An experimental investigation is performed to study flame appearance, flame stability, Soot free length fraction (SFLF) and CO emission of LPG diffusion flame. Effects of varying air and fuel velocities are analysed to understand the physical process involved in combustion. SFLF is measured to estimate the reduction of soot. Stability limits of the diffusion flame are characterized by the blowoff velocity. Emission characteristic in terms of CO level is measured at different equivalence ratios. Experimental results show that the air and fuel velocity strongly influences the appearance of LPG diffusion flame. At a constant fuel velocity, blue zone increases and the luminous zone decreases with the increase in air velocity. It is observed that the SFLF increases with increasing air velocity at a constant fuel velocity. It is observed that the blowoff velocity of the diffusion flame increases as fuel velocity increases. Comparison of emission for flame with and without swirl indicates that swirl results in low emission of CO and higher flame stability. Swirler with 45° vanes achieved the lowest CO emission of 30 ppm at Φ = 1.3.

Diffusion Flame Stability of Low Calorific Fuels

2015 ◽  
Vol 362 ◽  
pp. 29-37 ◽  
Author(s):  
N.R. Caetano ◽  
T.Z. Stapasolla ◽  
F.B. Peng ◽  
P.S. Schneider ◽  
F.M. Pereira ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Diffusion Flame ◽  
Large Scale ◽  
Industrial Applications ◽  
Flame Stabilization ◽  
Flame Stability ◽  
Classical Literature ◽  
Regions Of Stability ◽  
Lift Off ◽  
Stability Limits

Mechanisms related to diffusion flame stabilization have been the subject of several studies within the last decades due the industrial and scientific interests. Information on flame stability is of fundamental importance in energy efficiency and safety regarding industrial applications. Thus, an experimental study was performed in order to examine the flame characteristics and regions of stability limits. In this study, a representative burner of industrial applications was employed, which allows the stabilization of several combustion regimes. The lift-off and blow-out flame regimes were investigated for different proportions of carbon dioxide in natural gas. In this way, an analysis of the calorific fuel influence on the flame stability was performed based on the measurements and a comparison with classical literature models was done. The fuel dilution by adding carbon dioxide was found to decrease the soot production, leading to lower flame heights and also, lower lift-off and blow-out limits. Results obtained from this study encourage future works which consider flames in large scale, in order to equate to industrial applications.

Effect of Reactant Preheating on the Stability of Non-Premixed Methane/Air Flames

2010 ◽  
Author(s):  
Sylvain Lamige ◽  
Ce´dric Galizzi ◽  
Jiesheng Min ◽  
Julien Perles ◽  
Fre´de´ric Andre´ ◽  
...  
Keyword(s):  
Room Temperature ◽  
Initial Temperature ◽  
Flame Stability ◽  
Air Velocity ◽  
Lifted Flames ◽  
Local Extinctions ◽  
Lift Off ◽  
Temperature Levels ◽  
The Stability ◽  
Jet Velocities

This study details the influence of reactant temperature on the stability of non-premixed CH4/air co-flow jet flames. Flame characteristics have been studied for five temperature levels (from 295 K to 600 K). The hysteresis zone formed by the limits between attached and lifted flame translates towards higher methane jet velocities with an increase of initial temperature, independently of the air velocity range. Moreover, critical velocities vary linearly with initial temperature. In addition, attachment and lift-off heights have been obtained from CH* chemiluminescence visualization. Results point out that the attachment height decreases significantly with temperature. Observations also indicate that the intrinsic process of lifting is modified. Pre-lifting anchored flame local extinctions, not observed at room-temperature, appear at higher initial temperatures; their occurrence increases with temperature. The lift-off height of turbulent lifted flames is also reduced with temperature. Overall, results show that increasing local temperature in the stabilization zone enhances flame stability.

scholarly journals Flame stability limits of premixed low-swirl combustion

2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879087 ◽  
Author(s):  
Yinli Xiao ◽  
Zhibo Cao ◽  
Changwu Wang
Keyword(s):  
Flow Field ◽  
Vortex Breakdown ◽  
Flame Structure ◽  
Field Measurements ◽  
Operating Conditions ◽  
Oh Radicals ◽  
Flame Stability ◽  
Atmospheric Conditions ◽  
Swirl Burner ◽  
Stability Limits

The objective of this study is to gain a fundamental understanding of the flow-field and flame behaviors associated with a low-swirl burner. A vane-type low-swirl burner with different swirl numbers has been developed. The velocity field measurements are carried out with particle image velocimetry. The basic flame structures are characterized using OH radicals measured by planar laser-induced fluorescence. Three combustion regimes of low-swirl flames are identified depending on the operating conditions. For the same low-swirl injector under atmospheric conditions, attached flame is first observed when the incoming velocity is too low to generate vortex breakdown. Then, W-shaped flame is formed above the burner at moderate incoming velocity. Bowl-shaped flame structure is formed as the mixture velocity increases until it extinct. Local extinction and relight zones are observed in the low-swirl flame. Flow-field features and flame stability limits are obtained for the present burner.

scholarly journals Characteristics of diffusion flames with accelerated motion

2016 ◽  
Vol 20 (6) ◽  
pp. 2113-2124 ◽  
Author(s):  
Bo Lou ◽  
Yonghai Qiu ◽  
Jianhong Xu
Keyword(s):  
Growth Rate ◽  
Temperature Field ◽  
Diffusion Flame ◽  
Diffusion Flames ◽  
Visual Display ◽  
Liquefied Petroleum Gas ◽  
Combustion Heat ◽  
Accelerated Motion ◽  
Average Temperature ◽  
Flame Angle

The aim of this work is to present an experiment to study the characteristics of a laminar diffusion flame under acceleration. A Bunsen burner (nozzle diameter 8 mm), using liquefied petroleum gas as its fuel, was ignited under acceleration. The temperature field and the diffusion flame angle of inclination were visualised with the assistance of the visual display technology incorporated in MATLAB?. Results show that the 2-d temperature field under different accelerations matched the variation in average temperatures: they both experience three variations at different time and velocity stages. The greater acceleration has a faster change in average temperature with time, due to the accumulation of combustion heat: the smaller acceleration has a higher average temperature at the same speed. No matter what acceleration was used, in time, the flame angle of inclination increased, but the growth rate decreased until an angle of 90?: this could be explained by analysis of the force distribution within the flame. It is also found that, initially, the growth rate of angle with velocity under the greater acceleration was always smaller than that at lower accelerations; it was also different in flames with uniform velocity fire conditions.

The Influence of Chemical Inhibitor Addition on Reverse-Jet Flame Stabilization

1968 ◽  
Author(s):  
L. Bellamy ◽  
C. H. Barron ◽  
J. R. O’Loughlin
Keyword(s):  
Flame Stabilization ◽  
Flame Stability ◽  
Jet Flame ◽  
Rate Processes ◽  
Stability Limits ◽  
Chemical Rate

Flame stability limits produced by a reverse-jet flameholder are experimentally studied with a chemical inhibitor added to the gas stream issuing from the reverse-jet. The result of this addition is a reduction of flame stability limits. Such a reduction indicates the importance of the chemical rate processes in the flameholding phenomenon.

Investigation of the premixed methane–air combustion through the combined porous-free flame burner by numerical simulation

2019 ◽  
Vol 233 (6) ◽  
pp. 773-785 ◽  
Author(s):  
Seyed Mohammad Hashemi ◽  
Seyed Abdolmehdi Hashemi
Keyword(s):  
Porous Medium ◽  
Thermal Efficiency ◽  
Combustion Process ◽  
Stability Limit ◽  
Flame Stability ◽  
The Novel ◽  
Flame Thickness ◽  
Porous Burner ◽  
Flame Burner ◽  
Stability Limits

Combustion process of the premixed methane–air in a novel combined porous-free flame burner was investigated numerically. Two-dimensional model considering nonequilibrium thermal condition between the gas and solid phases was used and the combustion was simulated using reduced GRI 3.0 multistep chemical kinetics mechanism. To examine the validity of the implemented numerical model, the burner was manufactured and tested. Good agreement between the numerical results and experimental data were observed. Thermal flame thickness, flame stability limit, and thermal efficiency were discussed. Multimode heat transfer in the porous medium including convection, radiation, and conduction were quantified and perused. Results showed that the thermal thickness of laminar free flame established in the perforated portion of the burner was considerably less than thickness of submerged flame stabilized in the porous medium. Predicted results suggested that the flame stability limit was augmented in the combined burner compared to the burner with full porous foam. Analyses of the heat balance showed that the thermal efficiency of the combined porous-free flame burner was less than thermal efficiency of the full porous burner. Comparison of the full porous burner with the novel combined porous-free flame burner demonstrated that the combined burner caused higher stability limits and lower thermal efficiencies.

Experimental Study of Non-Premixed Flames of Liquefied Petroleum Gas and Air in Cross-Flow and the Effects of Fuel Properties on Flame Stability

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
S. Muthu Kumaran ◽  
Vasudevan Raghavan
Keyword(s):  
Premixed Flames ◽  
Cross Flow ◽  
Operating Conditions ◽  
Fuel Properties ◽  
Jet Flows ◽  
Flame Stability ◽  
Bluff Bodies ◽  
Liquefied Petroleum Gas ◽  
Air Jet ◽  
The Stability

Abstract Stability of flames are affected by fuel properties, geometry of the burner and operating conditions. In this experimental work, first the characteristics of non-premixed flames of Liquefied Petroleum Gas (LPG) and air in cross-flow configuration, where air jet flows perpendicular to the fuel stream, are studied experimentally. Flame transition and stability regimes of non-premixed flames of LPG and air, in a cross-flow burner without and with obstacles, are determined by systematically varying the fuel and air flow rates. Obstacles such as backward facing step and cylindrical bluff bodies are considered. Subsequently, the effects of fuel properties on the stability of flames are analyzed, Flame stability regimes of natural gas (methane) and biogas (methane and carbon-dioxide), measured from a similar burner are available in literature. These have been compared with the stability of LPG flames in terms of power rating of the burner and global equivalence ratio (defined for non-premixed flames).

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