Effect of Swirl Number on Combustion Characteristics in a Natural Gas Diffusion Flame

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
İlker Yılmaz
Keyword(s):  
Fluid Dynamics ◽  
Natural Gas ◽  
Diffusion Flame ◽  
Recirculation Zone ◽  
Reaction Scheme ◽  
Gas Diffusion ◽  
Combustion Characteristics ◽  
Model Parameters ◽  
Swirl Number ◽  
Simulation Results

This paper presents the effect of swirl number on combustion characteristics such as temperature, velocity, gas concentrations in a natural gas diffusion flame. Numerial simulations carried out using the commercial computational fluid dynamics (CFD) code, Fluent by choosing appropriate model parameters. The combustion reaction scheme in the flame region was modeled using eddy dissipation model with one step global reaction scheme. A standard k-ε turbulence model for turbulent closure and P-I radiation model for flame radiation inside the combustor is used in the numerical simulations. In order to investigate the swirling effect on the combustion characteristics, seven different swirl numbers including 0; 0.1; 0.2; 0.3; 0.4; 0.5; and 0.6 are used in the study. Numerical results are validated and compared with the published experimental and simulation results. A good consistency is found between the present results and those published measurement and simulation results in the available literature. The results shown that the combustion characteristics such as the flame temperature, the gas concentrations including CO2, H2O, O2, and CH4 are strongly affected by the swirl number. Depending on the degree of swirl, the fluid dynamics behavior of natural gas diffusion flame including axial velocity distribution, central recirculation zone (CTRZ) and external recirculation zone (ETRZ) were also strongly affected.

Comparative experimental and numerical investigation of a piloted turbulent natural-gas diffusion flame

1994 ◽  
Vol 25 (1) ◽  
pp. 1241-1248 ◽  
Author(s):  
T.W.J. Peeters ◽  
P.P.J. Stroomer ◽  
J.E. de Vries ◽  
D.J.E.M. Roekaerts ◽  
C.J. Hoogendoorn
Keyword(s):  
Natural Gas ◽  
Numerical Investigation ◽  
Diffusion Flame ◽  
Gas Diffusion

scholarly journals SIMULACION NUMERICA DE LA COMBUSTION EN UNA CALDERA A GAS NATURAL UTILIZANDO UN MECANISMO DE REACCION REDUCIDO

2001 ◽  
Vol 1 (1) ◽  
pp. 64
Author(s):  
Victoria Echaniz ◽  
Eduardo Brizuela
Keyword(s):  
Heat Transfer ◽  
Natural Gas ◽  
Diffusion Flame ◽  
Turbulent Diffusion ◽  
Reaction Scheme ◽  
Turbulent Diffusion Flame ◽  
Full Size ◽  
Operational Conditions ◽  
Break Up ◽  
Finite Volume Approach

En este trabajo se resuelve por el método de los volúmenes finitos, y aplicando un Esquema de Reacción Reducido y conceptos de Eddy Break Up, la combustión de gas natural en aire en una caldera de vapor. Se presentan resultados de la simulación de una llama de difusión turbulenta, en escala natural y condiciones operacionales, con transmisión de calor por conducción/convección y radiación. Por tratarse de una tarea en progreso y de largo alcance que involucra una caldera en servicio los resultados son preliminares y la comparación con resultados experimentales es limitada. No obstante, los resultados obtenidos son considerados satisfactorios, aunque indican que es necesario continuar refinando los modelos de mezclado y radiación para reproducir mejor las condiciones reales. ABSTRACT Combustion of natural gas in air in a utility boiler is simulated by means of a finite volume approach, using a Reduced Reaction Scheme and Eddy Break Up concepts. Results are presented for a turbulent diffusion flame, under operational conditions and in full size, including heat transfer by conduction/convection and radiation. Preliminary results only are presented and a limited comparison with experimental results is made due to the scope of the task which involves a facility in service. Nevertheless, results are considered satisfactory, although there are indications that it is necessary to continue refining the mixing and radiation models for better matching with operational conditions.

scholarly journals SIMULACION NUMERICA DE LA COMBUSTION EN UNA CALDERA A GAS NATURAL UTILIZANDO UN MECANISMO DE REACCION REDUCIDO

2002 ◽  
Vol 1 (1) ◽  
Author(s):  
Victoria Echaniz ◽  
Eduardo Brizuela
Keyword(s):  
Heat Transfer ◽  
Natural Gas ◽  
Diffusion Flame ◽  
Turbulent Diffusion ◽  
Reaction Scheme ◽  
Turbulent Diffusion Flame ◽  
Full Size ◽  
Operational Conditions ◽  
Break Up ◽  
Finite Volume Approach

En este trabajo se resuelve por el método de los volúmenes finitos, y aplicando un Esquema de Reacción Reducido y conceptos de Eddy Break Up, la combustión de gas natural en aire en una caldera de vapor. Se presentan resultados de la simulación de una llama de difusión turbulenta, en escala natural y condiciones operacionales, con transmisión de calor por conducción/convección y radiación. Por tratarse de una tarea en progreso y de largo alcance que involucra una caldera en servicio los resultados son preliminares y la comparación con resultados experimentales es limitada. No obstante, los resultados obtenidos son considerados satisfactorios, aunque indican que es necesario continuar refinando los modelos de mezclado y radiación para reproducir mejor las condiciones reales. ABSTRACT Combustion of natural gas in air in a utility boiler is simulated by means of a finite volume approach, using a Reduced Reaction Scheme and Eddy Break Up concepts. Results are presented for a turbulent diffusion flame, under operational conditions and in full size, including heat transfer by conduction/convection and radiation. Preliminary results only are presented and a limited comparison with experimental results is made due to the scope of the task which involves a facility in service. Nevertheless, results are considered satisfactory, although there are indications that it is necessary to continue refining the mixing and radiation models for better matching with operational conditions.

Prediction of a high swirled natural gas diffusion flame using a PDF model

Fuel ◽  
2009 ◽  
Vol 88 (2) ◽  
pp. 374-381 ◽  
Author(s):  
A. Khelil ◽  
H. Naji ◽  
L. Loukarfi ◽  
G. Mompean
Keyword(s):  
Natural Gas ◽  
Diffusion Flame ◽  
Gas Diffusion ◽  
Pdf Model

Monte Carlo PDF modelling of a turbulent natural-gas diffusion flame

1997 ◽  
Vol 1 (1) ◽  
pp. 79-96 ◽  
Author(s):  
P.A. Nooren ◽  
H.A. Wouters ◽  
T.W.J. Peeters ◽  
D. Roekaerts ◽  
U. Maas ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Natural Gas ◽  
Diffusion Flame ◽  
Gas Diffusion

The effects of swirl number on the combustion characteristics in an internally-staged combustor

2021 ◽  
pp. 095440622110373
Author(s):  
Tiezheng Zhao ◽  
Xiao Liu ◽  
Zhihao Zhang ◽  
Jialong Yang ◽  
Hongtao Zheng
Keyword(s):  
Flow Field ◽  
Recirculation Zone ◽  
Three Dimensional ◽  
Combustion Characteristics ◽  
Maximum Temperature ◽  
High Concentration ◽  
Swirl Number ◽  
The Third ◽  
Flamelet Generated Manifold ◽  
Swirling Flame

The three-dimensional turbulent swirling flame in an internally-staged combustor is numerically investigated. Four cases over a range of swirl intensities are explored by the Flamelet Generated Manifold model in this paper. Special attention is paid to analyzing the variation of the flow field, temperature, major species concentrations and emissions. The results clearly show the effects of swirl number on the size of the center recirculation zone, fuel distribution and combustion characteristics. When the third premixed stage swirl number increases from 0.6 to 1.2, the axial length of the center recirculation zone decreases by 3.7%, while the radial length increases by 6.9%. The characteristics of the flow field play an important role in the spatial distribution of the fuel, which further affects the temperature distribution in the combustor. The backflow effect is enhanced, resulting in a greater concentration of fuel at the outlet of the swirler. After the maximum temperature is reached at the exit position of the pilot stage, the temperature decreases compared to the peak temperature downstream as the proportion of premixed combustion mode increases. This creates a high concentration region of OH at the outlet of the pilot stage injector and the heat release region is squeezed upstream. At the same time, the volume of the high-temperature region downstream of the pilot stage is reduced. In addition, as the swirl number of the third premixed stage increases from 0.6 to 1.2, the emissions of NO and CO decrease by 28.7% and 75%, respectively.

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