Differential Mass and Energy Balances in the Flame Zone From a Practical Fuel Injector in a Technology Combustor

1997 ◽  
Vol 119 (2) ◽  
pp. 352-361 ◽  
Author(s):  
D. L. Warren ◽  
P. O. Hedman
Keyword(s):  
Heat Release ◽  
Air Force ◽  
Flame Temperature ◽  
Fuel Injector ◽  
Gas Temperature ◽  
Flame Zone ◽  
Brigham Young University ◽  
Air Force Base ◽  
Energy Balances ◽  
Mass And Energy Balances

This paper presents further analysis of experimental results from an Air Force program conducted by researchers at Brigham Young University (BYU), Wright-Patterson Air Force Base (WPAFB), and Pratt and Whitney Aircraft Co. (P&W) (Hedman et al., 1994a, 1995). These earlier investigations of the combustion of propane in a practical burner installed in a technology combustor used: (1) digitized images from video and still film photographs to document observed flame behavior as fuel equivalence ratio was varied, (2) sets of LDA data to quantify the velocity flow fields existing in the burner, (3) CARS measurements of gas temperature to determine the temperature field in the combustion zone, and to evaluate the magnitude of peak temperature, and (4) two-dimensional PLIF images of OH radical concentrations to document the instantaneous location of the flame reaction zones. This study has used the in situ velocity and temperature measurements from the earlier study, suitably interpolated, to determine local mass and energy balances on differential volume elements throughout the flame zone. The differential mass balance was generally within about ±10 percent with some notable exceptions near regions of very high shear and mixing. The local differential energy balance has qualitatively identified the regions of the flame where the major heat release is occurring, and has provided quantitative values on the rate of energy release (up to −400 kJ/m3s). The velocity field data have also been used to determine Lagrangian pathlines through the flame zone. The local velocity and temperature along selected pathlines have allowed temperature timelines to be determined. The temperature generally achieves its peak value, often near the adiabatic flame temperature, within about 10 ms. These temperature timelines, along with the quantitative heat release data, may provide a basis for evaluating kinetic combustion models.

scholarly journals Differential Mass and Energy Balances in the Flame Zone From a Practical Fuel Injector in a Technology Combustor

1995 ◽  
Author(s):  
David L. Warren ◽  
Paul O. Hedman
Keyword(s):  
Heat Release ◽  
Air Force ◽  
Flame Temperature ◽  
Fuel Injector ◽  
Gas Temperature ◽  
Flame Zone ◽  
Brigham Young University ◽  
Air Force Base ◽  
Energy Balances ◽  
Mass And Energy Balances

This paper presents further analysis of experimental results from an Air Force program conducted by researchers at Brigham Young University (BYU) Wright-Patterson Air Force Base (WPAFB), and Pratt and Whitney Aircraft Co. (P&W) (Hedman, et al., 1994a and 1994b). These earlier investigations of the combustion of propane in a practical burner installed in a technology combustor used: 1) digitized images from video and still film photographs to document observed flame behavior as fuel equivalence ratio was varied, 2) sets of LDA data to quantify the velocity flow fields existing in the burner, 3) CARS measurements of gas temperature to determine the temperature field in the combustion zone, and to evaluate the magnitude of peak temperature, and 4) two-dimensional PLIF images of OH radical concentrations to document the instantaneous location of the flame reaction zones. This study has used the in situ velocity and temperature measurements from the earlier study, suitably interpolated, to determine local mass and energy balances on differential volume elements throughout the flame zone. The differential mass balance was generally within about ± 10% with some notable exceptions near regions of very high shear and mixing. The local differential energy balance has qualitatively identified the regions of the flame where the major heat release is occurring, and has provided quantitative values on the rate of energy release (up to −400 kJ/m3s). The velocity field data have also been used to determine Lagrangian pathlines through the flame zone. The local velocity and temperature along selected pathlines have allowed temperature timelines to be determined. The temperature generally achieves its peak value, often near the adiabatic flame temperature, within about 10 ms. These temperature timelines, along with the quantitative heat release data may provide a basis for evaluating kinetic combustion models.

scholarly journals Observations of Flame Behavior From a Practical Fuel Injector Using Gaseous Fuel in a Technology Combustor

1994 ◽  
Author(s):  
Paul O. Hedman ◽  
Geoffrey J. Sturgess ◽  
David L. Warren ◽  
Larry P. Goss ◽  
Dale T. Shouse
Keyword(s):  
Gas Turbine ◽  
Air Force ◽  
Diffusion Flames ◽  
Fuel Injector ◽  
Gas Temperature ◽  
Brigham Young University ◽  
Lean Blowout ◽  
Reaction Zones ◽  
Air Force Base ◽  
Whitney Aircraft

This paper presents results from an Air Force program being conducted by researchers at Brigham Young University (BYU) Wright-Patterson Air Force Base (WPAFB), and Pratt and Whitney Aircraft Co (P&W). This study is part of a comprehensive effort being supported by the Aero Propulsion and Power Laboratory at Wright-Patterson Air Force Base, and Pratt and Whitney Aircraft, Inc. in which simple and complex diffusion flames are being studied to better understand the fundamentals of gas turbine combustion near lean blowout. The program’s long term goal is to improve the design methodology of gas turbine combustors. This paper focuses on four areas of investigation: 1) digitized images from still film photographs to document the observed flame structures as fuel equivalence ratio was varied, 2) sets of LDA data to quantify the velocity flow fields existing in the burner, 3) CARS measurements of gas temperature to determine the temperature field in the combustion zone, and to evaluate the magnitude of peak temperature, and 4) two-dimensional images of OH radical concentrations using PLIF to document the instantaneous location of the flame reaction zones.

Observations of Flame Behavior From a Practical Fuel Injector Using Gaseous Fuel in a Technology Combustor

1995 ◽  
Vol 117 (3) ◽  
pp. 441-452 ◽  
Author(s):  
P. O. Hedman ◽  
G. J. Sturgess ◽  
D. L. Warren ◽  
L. P. Goss ◽  
D. T. Shouse
Keyword(s):  
Gas Turbine ◽  
Air Force ◽  
Diffusion Flames ◽  
Fuel Injector ◽  
Gas Temperature ◽  
Brigham Young University ◽  
Lean Blowout ◽  
Reaction Zones ◽  
Air Force Base ◽  
Flame Behavior

This paper presents results from an Air Force program being conducted by researchers at Brigham Young University (BYU) Wright-Patterson Air Force Base (WPAFB), and Pratt and Whitney (P&W). This study is part of a comprehensive effort being supported by the Aero Propulsion and Power Laboratory at Wright-Patterson Air Force Base, and Pratt and Whitney in which simple and complex diffusion flames are being studied to understand better the fundamentals of gas turbine combustion near lean blowout. The program’s long-term goal is to improve the design methodology of gas turbine combustors. This paper focuses on four areas of investigation: (1) digitized images from still film photographs to document the observed flame structures as fuel equivalence ratio was varied, (2) sets of LDA data to quantify the velocity flow fields existing in the burner (3) CARS measurements of gas temperature to determine the temperature field in the combustion zone, and to evaluate the magnitude of peak temperature, and (4) two-dimensional images of OH radical concentrations using PLIF to document the instantaneous location of the flame reaction zones.

Combustion Characteristics of Ultrafine Coal Particles-Light Diesel Oil Mixtures in a Cylindrical Horizontal Furnace

2020 ◽  
Vol 143 (7) ◽  
Author(s):  
ELSaeed Saad ELSihy ◽  
M. M. Salama ◽  
M. A. Shahein ◽  
H. A. Moneib ◽  
M. K. Abd EL-Rahman
Keyword(s):  
Flame Temperature ◽  
Fuel Mixture ◽  
Combustion Characteristics ◽  
Slight Reduction ◽  
Percentage Increase ◽  
Gas Temperature ◽  
Flame Zone ◽  
Constant Input ◽  
Coal Particles ◽  
Loading Ratio

Abstract This work presents an experimental study that aims at investigating the effect of the loading ratio of coal in a coal-diesel fuel mixture on the combustion characteristics and exhaust emissions. Sub-bituminous coal from the El-Maghara coal mine is utilized. It is washed, dried, and grounded to particle sizing of ≤ 30 μm. The experiments are conducted inside a horizontal, segmented water-cooled cylindrical furnace fitted with a coaxial burner having a central air-assisted atomizer for oil-coal mixture admittance. All experiments are executed at constant input heat of 350 kW and air-to-fuel ratio of 15:1 while varying the percentage (mass basis: 5% and 10%) of coal in the fuel mixture. The measurements within the flame zone include mean gas temperatures, dry volumetric analyses of species (CO2, NOx, and O2) concentrations, and the accumulative heat transfer to the cooling jacket along the combustor. All measurements are compared regarding the pure oil flame. The results indicate that increasing the coal-loading ratio up to 5 wt% leads to a progressive increase in the accumulated heat transferred and the combustor overall efficiency from 40% to 58% within a percentage increase around 45%. In addition, there is a slight reduction in mean gas temperature within the flame zone when compared with the pure oil flame. The reduced flame temperature due to increasing the coal-loading ratio caused a decline in the volumetric concentrations of NOx from 100 ppm to 20 ppm as expected.

Using CFD for Time-Delay Modeling of Premix Flames

2001 ◽  
Author(s):  
Peter Flohr ◽  
Christian Oliver Paschereit ◽  
Bart van Roon ◽  
Bruno Schuermans
Keyword(s):  
Time Delay ◽  
Heat Release ◽  
Time Delays ◽  
Flame Temperature ◽  
Model Fitting ◽  
Operating Conditions ◽  
Fuel Injector ◽  
Fuel Injectors ◽  
Flame Shape ◽  
Good Agreement

This paper presents a refined model of the transfer function of a premix burner, compares the model with experiments, and discusses how the model can be used to map stability characteristics of a combustion system. The model is based on the assumption that acoustic velocity fluctuations cause modulations of fuel concentration at the fuel injector which, after a time delay, result in fluctuating heat release rates at the flame. Here, the time delay is modeled as a multitude of single time delays. The distribution of these time delays can be found either from model fitting to experimental data, or can be obtained directly from numerical simulations of the burner. The effect of distributed time delays is caused by axially distributed fuel injectors, turbulent diffusion, and a non-planar flame shape. As a consequence, heat release fluctuations at higher frequencies cancel, an effect which is also observed experimentally. It is found that the model is generally in good agreement with experiments. It is also demonstrated that the model can be used to map the burner stability charactistics for various operating conditions, e.g. for variations in power and flame temperature. A stability analysis is performed by incorporating the flame model into a combustor network model.

scholarly journals Heat and Mass Transfer in Reduction Zone of Sponge Iron Reactor

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Bayu Alamsari ◽  
Shuichi Torii ◽  
Azis Trianto ◽  
Yazid Bindar
Keyword(s):  
Kinetic Equations ◽  
Sponge Iron ◽  
Inlet Temperature ◽  
Gas Temperature ◽  
Reduction Zone ◽  
Shift Reaction ◽  
Energy Balances ◽  
Counter Current ◽  
Water Gas ◽  
Mass And Energy Balances

Numerical prediction is performed on reduction zone of iron ore reactor which is a part of counter current gas-solid reactor for producing sponge iron. The aim of the present study is to investigate the effect of reduction gas composition and temperature on quality and capacity of sponge iron products through mathematical modeling arrangement and simulation. Simultaneous mass and energy balances along the reactor lead to a set of ordinary differential equation which includes kinetic equations. Kinetic equations of reduction of hematite to iron metal, methane reforming, and water gas shift reaction are taken into account in the model. Hydrogen and carbon monoxide are used as reduction gas. The equations were solved by finite element method. Prediction shows an increase in H2 composition while an attenuation of CO produces higher metallization degree. Metallization degree is also increased with an increase in gas inlet temperature. It is found that reduction gas temperature over 973°C (1246 K) is not recommended because the formation of sticky iron will be initiated.

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