D111 Diffusion flame length : Effects of buoyant and swirling flows

2010 ◽  
Vol 2010 (0) ◽  
pp. 89-90
Author(s):  
Kazunori Kuwana ◽  
Tomoyuki Ochiai
Keyword(s):  
Diffusion Flame ◽  
Flame Length ◽  
Swirling Flows ◽  
Length Effects

Effects of Air Temperature on Combustion Characteristics of LPG Diffusion Flame

2020 ◽  
Vol 1008 ◽  
pp. 128-138
Author(s):  
Ahmed M. Salman ◽  
Ibrahim A. Ibrahim ◽  
Hamada M. Gad ◽  
Tharwat M. Farag
Keyword(s):  
Air Temperature ◽  
Diffusion Flame ◽  
Nitrogen Addition ◽  
Flame Length ◽  
Combustion Characteristics ◽  
Operating Conditions ◽  
Low Oxygen ◽  
Air Temperatures ◽  
Air Stream ◽  
Wide Range

In the present study, the combustion characteristics of LPG gaseous fuel diffusion flame at elevated air temperatures were experimentally investigated. An experimental test rig was manufactured to examine a wide range of operating conditions. The investigated parameters are the air temperatures of 300, 350, 400, 450, and 500 K with constant percentage of nitrogen addition in combustion air stream of 5 % to give low oxygen concentration of 18.3 % by mass at constant air swirl number, air to fuel mass ratio, and thermal load of 1.5, 30, and 23 kW, respectively. The gaseous combustion characteristics were represented as axial and radial temperatures distributions, temperatures gradient, visible flame length and species concentrations. The results indicated that as the air temperature increased, the chemical reaction rate increased and flame volume decreased, the combustion time reduced leading to a reduction in flame length. The NO concentration reaches its maximum values near the location of the maximum centerline axial temperature. Increasing the combustion air temperature by 200 K, the NO consequently O2 concentrations are increased by about % 355 and 20 % respectively, while CO2 and CO concentrations are decreased by about % 21 and 99 % respectively, at the combustor end.

scholarly journals Performance of a Reduced NOx Diffusion Flame Combustor for the MS5002 Gas Turbine

1999 ◽  
Author(s):  
Alan S. Feitelberg ◽  
Michael D. Starkey ◽  
Richard B. Schiefer ◽  
Roointon E. Pavri ◽  
Matt Bender ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Diffusion Flame ◽  
Turbulent Flame ◽  
Flame Length ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
British Petroleum ◽  
Complete Combustion ◽  
Significant Difference ◽  
Fuel Nozzle

This paper describes a reduced NOx diffusion flame combustor that has been developed for the MS5002 gas turbine. Laboratory tests have shown that when firing with natural gas, without water or steam injection, NOx emissions from the new combustor are about 40% lower than NOx emissions from the standard MS5002 combustor. CO emissions are virtually unchanged at base load, but increase at part load conditions. The laboratory results were confirmed in 1997 by a commercial demonstration test at a British Petroleum site in Prudhoe Bay, Alaska. The standard MS5002 gas turbine is equipped with a conventional, swirl stabilized diffusion flame combustion system. The twelve standard combustors in an MS5002 turbine are cylindrical cans, approximately 27 cm (10.5 inches) in diameter and 112 cm (44 inches) long. A small, annular, vortex generator surrounds the single fuel nozzle that is centered at the inlet to each can. The walls of the cans are louvered for cooling, and contain an array of mixing and dilution holes that provide the air needed to complete combustion and dilute the burned gas to the desired turbine inlet temperature. The new, reduced NOx emissions combustor (referred to as a “lean head end”, or LHE, combustor) retains all of the key features of the conventional combustor: the only significant difference is the arrangement of the mixing and dilution holes in the cylindrical combustor can. By optimizing the number, diameter, and location of these holes, NOx emissions were substantially reduced. The materials of construction, fuel nozzle, and total combustor air flow were unchanged. The differences in NOx emissions between the standard and LHE combustors, as well as the variations in NOx emissions with firing temperature, were well correlated using turbulent flame length arguments. Details of this correlation are also presented.

Characteristics of a Laminar Diffusion Flame in a Cross-Flow of Combustion Products

2005 ◽  
Author(s):  
M. A. Simon ◽  
B. D. Baird ◽  
S. R. Gollahalli
Keyword(s):  
Diffusion Flame ◽  
Equivalence Ratio ◽  
Cross Flow ◽  
Combustion Products ◽  
Flame Length ◽  
No Production ◽  
Flat Flame ◽  
Laminar Diffusion ◽  
Flame Burner ◽  
The Cross

This study was an investigation of the characteristics of a horizontal laminar diffusion flame established from a tubular burner in a buoyant vertical flow vitiated with combustion products created by a flat flame. The effects of varying flat flame equivalence ratio on these characteristics were studied. Applications of this study include exhaust gas recirculation (EGR), staged combustion in furnaces, and afterburners in jet engines. The fuel used for both the horizontal (cross-flow flame) and the flat flame in this study was propane. For a range of flat flame burner equivalence ratio (0.6 to 0.9), measurements of cross-flow flame length, and global emissions of NO were made. The mass flow rate of propane delivered to the cross-flow flame was held constant during these measurements. The flames were photographed with a digital camera. Profiles of combustion species concentrations and temperature were taken at 25% and 50% of the cross-flow flame length for flat flame burner equivalence ratios of 0.6 and 0.8, and for a non-combustion case (air flow only) in the flat flame. It was found that increasing the flat flame burner equivalence ratio caused an increase in the length of the cross-flow flame. The maximum temperature of the cross-flow flame decreased with increasing flat flame burner equivalence ratio. The introduction of the cross-flow flame increased the NO production in a flat flame with an equivalence ratio of 0.6, but did not significantly affect the NO production in a flat flame of an equivalence ratios of 0.7 or 0.8, and reduced it (by as much as 25%) in a flat flame of equivalence ratio of 0.9. This reduction of NO production and flame temperature and increase in flame length with increasing flat flame equivalence ratio was attributed to the reduction of oxygen available to the cross-flow flame. These results were supported with the in-flame combustion species concentration profiles.

Turbulent jet diffusion flame length evolution with cross flows in a sub-pressure atmosphere

2015 ◽  
Vol 106 ◽  
pp. 703-708 ◽  
Author(s):  
Qiang Wang ◽  
Longhua Hu ◽  
Xiaozheng Zhang ◽  
Xiaolei Zhang ◽  
Shouxiang Lu ◽  
...  
Keyword(s):  
Diffusion Flame ◽  
Flame Length ◽  
Turbulent Jet

Reduced NOx Diffusion Flame Combustors for Industrial Gas Turbines

2000 ◽  
Vol 123 (4) ◽  
pp. 757-765 ◽  
Author(s):  
A. S. Feitelberg ◽  
V. E. Tangirala ◽  
R. A. Elliott ◽  
R. E. Pavri ◽  
R. B. Schiefer
Keyword(s):  
Diffusion Flame ◽  
Gas Turbines ◽  
Turbulent Flame ◽  
Steam Injection ◽  
Flame Length ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Complete Combustion ◽  
Industrial Gas Turbines ◽  
Fuel Nozzle

This paper describes reduced NOx diffusion flame combustors that have been developed for both simple cycle and regenerative cycle MS3002 and MS5002 gas turbines. Laboratory tests have shown that when firing with natural gas, without water or steam injection, NOx emissions from the new combustors are about 40 percent lower than NOx emissions from the standard combustors. CO emissions are virtually unchanged at base load, but increase at part load conditions. Commercial demonstration tests have confirmed the laboratory results. The standard combustors on both the MS3002 and MS5002 gas turbine are cylindrical cans, approximately 10.5 inches (27 cm) in diameter. A single fuel nozzle is centered at the inlet to each can and produces a swirl stabilized diffusion flame. The walls of the cans are louvered for cooling, and contain an array of mixing and dilution holes that provide the air needed to complete combustion and dilute the burned gas to the desired turbine inlet temperature. The MS3002 turbine is equipped with six combustor cans, while the MS5002 turbine is equipped with twelve combustors. The new, reduced NOx emissions combustors (referred to as a “lean head end,” or LHE, combustors) retain all of the key features of the conventional combustors; the only major difference is the arrangement of the mixing and dilution holes in the cylindrical combustor cans. By optimizing the number, diameter, and location of these holes, NOx emissions can be reduced considerably. Minor changes are also sometimes made to the combustor cap. The materials of construction, pressure drop, and fuel nozzle are all unchanged. The differences in NOx emissions between the standard and LHE combustors, as well as the variations in NOx emissions with firing temperature, are well correlated using turbulent flame length arguments. Details of this correlation are presented.

scholarly journals EXPERIMENTAL STUDY OF TURBULENT LPG TURBULENT INVERSE DIFFUSION FLAME IN COAXIAL BURNER

2013 ◽  
pp. 184-190
Author(s):  
S.SREENATHA REDDY ◽  
K.L.N MURTHY ◽  
V. PANDURANGADU
Keyword(s):  
Experimental Study ◽  
Diffusion Flame ◽  
Flame Structure ◽  
Flame Length ◽  
Global Strain ◽  
Fuel Jet ◽  
Inverse Diffusion ◽  
Inverse Diffusion Flame ◽  
Global Strain Rate ◽  
Centerline Temperature

The present experimental study investigates the turbulent LPG Inverse Diffusion Flame (IDF) stabilized in a coaxial burner in terms of flame appearance, visible flame length, centerline temperature distribution and oxygen concentration and NOX emission characteristics. The effect of air-fuel jet velocities on visible flame length is interpreted using global strain rate and a new devised parameter called Modified Momentum Ratio. The centerline temperature exhibits a steeper increase in the lower premixed zone of the IDF due to the enhanced premixing. Subsequently it declines gradually in the upper luminous portion owing to soot radiation and heat losses to the ambient. Further, the centerline oxygen depletes rapidly in the lower blue zone but found to increase gradually in the upper luminous portion of IDF. The centerline temperature and oxygen distribution along the flame length revealed the dual flame structure of IDF. The EINOX values exhibited a bell shaped profile and reached a maximum value around stoichiometric overall equivalence ratio.

scholarly journals Effect of Gravity on a Diffusion Flame Length of Fuel Jet.

1999 ◽  
Vol 65 (633) ◽  
pp. 1786-1792 ◽  
Author(s):  
Hiroyuki SATO ◽  
Kenji AMAGAI ◽  
Masataka ARAI
Keyword(s):  
Diffusion Flame ◽  
Flame Length ◽  
Fuel Jet

Effect of cross-wind on near-wall buoyant turbulent diffusion flame length and tilt

Fuel ◽  
2016 ◽  
Vol 186 ◽  
pp. 350-357 ◽  
Author(s):  
Fei Tang ◽  
Lianjian Li ◽  
Qiang Wang ◽  
Qin Shi
Keyword(s):  
Diffusion Flame ◽  
Turbulent Diffusion ◽  
Flame Length ◽  
Turbulent Diffusion Flame ◽  
Near Wall

scholarly journals Influence of DC Electric Field on the Propane-Air Diffusion Flames and NOx Formation

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5745
Author(s):  
Sang-Min Kim ◽  
Kyeong-Soo Han ◽  
Seung-Wook Baek
Keyword(s):  
Electric Field ◽  
Diffusion Flame ◽  
Diffusion Flames ◽  
Combustion Process ◽  
Flame Length ◽  
Nox Emission ◽  
Nox Formation ◽  
Dc Electric Field ◽  
Air Diffusion ◽  
Reduction Percentage

The aim of this research is to investigate the effects of a direct current (DC) electric field on the combustion behavior of a co-flow propane diffusion flame. The flame length and NOx emission were observed and measured. The electric field enhances the combustion process of propane diffusion flame by causing the movement of ions and molecules in the flame, resulting in a change in the shape of the flame. The flame heights decrease with an increase in the applied voltage and polarity, a more dominant effect to be observed with a positive DC electric field. However, for the applied negative polarity, the inner-cone of the propane diffusion flame is shifted by the electric field. Drastic reduction in the NOx emission is observed with an increase in the applied DC voltage and polarity. In the existing system, the reduction percentage of NOx is within the range of 55 to 78%.

Performance of a Reduced NOx Diffusion Flame Combustor for the MS5002 Gas Turbine

2000 ◽  
Vol 122 (2) ◽  
pp. 301-306 ◽  
Author(s):  
Alan S. Feitelberg ◽  
Michael D. Starkey ◽  
Richard B. Schiefer ◽  
Roointon E. Pavri ◽  
Matt Bender ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Diffusion Flame ◽  
Turbulent Flame ◽  
Flame Length ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
British Petroleum ◽  
Complete Combustion ◽  
Significant Difference ◽  
Fuel Nozzle

This paper describes a reduced NOx diffusion flame combustor that has been developed for the MS5002 gas turbine. Laboratory tests have shown that when firing with natural gas, without water or steam injection, NOx emissions from the new combustor are about 40 percent lower than NOx emissions from the standard MS5002 combustor. CO emissions are virtually unchanged at base load, but increase at part load conditions. The laboratory results were confirmed in 1997 by a commercial demonstration test at a British Petroleum site in Prudhoe Bay, Alaska. The standard MS5002 gas turbine is equipped with a conventional, swirl stabilized diffusion flame combustion system. The twelve standard combustors in an MS5002 turbine are cylindrical cans, approximately 27 cm (10.5 in.) in diameter and 112 cm (44 in.) long. A small, annular, vortex generator surrounds the single fuel nozzle that is centered at the inlet to each can. The walls of the cans are louvered for cooling, and contain an array of mixing and dilution holes that provide the air needed to complete combustion and dilute the burned gas to the desired turbine inlet temperature. The new, reduced NOx emissions combustor (referred to as a “lean head end,” or LHE, combustor) retains all of the key features of the conventional combustor; the only significant difference is the arrangement of the mixing and dilution holes in the cylindrical combustor can. By optimizing the number, diameter, and location of these holes, NOx emissions were substantially reduced. The materials of construction, fuel nozzle, and total combustor air flow were unchanged. The differences in NOx emissions between the standard and LHE combustors, as well as the variations in NOx emissions with firing temperature, were well correlated using turbulent flame length arguments. Details of this correlation are also presented. [S0742-4795(00)01602-1]

Sign in / Sign up

Export Citation Format

Share Document