Effects of H2 enrichment on flame stability and pollutant emissions for a kerosene/air swirled flame with an aeronautical fuel injector

2011 ◽  
Vol 33 (2) ◽  
pp. 2927-2935 ◽  
Author(s):  
Joseph Burguburu ◽  
Gilles Cabot ◽  
Bruno Renou ◽  
Abdelkrim M. Boukhalfa ◽  
Michel Cazalens
Keyword(s):  
Pollutant Emissions ◽  
Flame Stability ◽  
Fuel Injector

Effect of Multi-Tube Fuel Injector Design on Flame Stability and NOx Pollutant Emissions from Syngas Flames

2014 ◽  
Author(s):  
Sudipa Sarker ◽  
Sarzina Hossain ◽  
Sergio Maldonado ◽  
Norman D. Love ◽  
Ahsan R. Choudhuri
Keyword(s):  
Pollutant Emissions ◽  
Flame Stability ◽  
Fuel Injector ◽  
Injector Design

A numerical study on the flame characteristics and pollutant emissions in a premixed burner: Comparison between porous and solid bluff bodies

2019 ◽  
Vol 234 (3) ◽  
pp. 353-364 ◽  
Author(s):  
Mahdi Mollamahdi ◽  
Seyed Abdolmehdi Hashemi
Keyword(s):  
Pressure Drop ◽  
Combustion Chamber ◽  
Methane Conversion ◽  
Conversion Rate ◽  
Bluff Body ◽  
Pollutant Emissions ◽  
Outer Diameter ◽  
Flame Stability ◽  
Bluff Bodies ◽  
No Emissions

The effects of porous and solid bluff bodies in the combustion chamber on flame stability limits, gas and solid temperature distributions, pressure drop, methane conversion rate, and CO and NO emissions are examined numerically. The porous and solid bluff bodies are made of SiC with the inner diameter of 50 mm, the outer diameter of 90 mm, and the length of 22 mm. In this study, Renormalization Group k–ε is used for modeling of turbulence. Eddy dissipation concept is selected for modeling of the interaction between turbulence and chemistry. A reduced mechanism based on GRI 3.0 consisting of 16 species and 41 reactions is employed to model methane combustion. The results indicate that the upper flame stability limit can be diminished by adding porous bluff body in the combustion chamber instead of the solid bluff body. Besides, the pressure drop, CO and NO emissions in the combustion chamber with solid bluff body are higher than those of porous bluff body, while the methane conversion rate increases by replacing porous bluff body instead of solid bluff body in the combustion chamber.

scholarly journals Emissions Reduction by Varying the Swirler Airflow Split in Advanced Gas Turbine Combustors

1992 ◽  
Author(s):  
Gerald J. Micklow ◽  
Subir Roychoudhury ◽  
H. Lee Nguyen ◽  
Michael C. Cline
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Numerical Study ◽  
Pollutant Emissions ◽  
Nasa Lewis Research ◽  
Fuel Injector ◽  
Lean Burn ◽  
Lean Combustion ◽  
Fuel Nozzle

A rich burn/quick mix/lean burn (RQL) combustor concept for reducing pollutant emissions is currently under investigation at the NASA Lewis Research Center (LeRC). A numerical study was performed to investigate the chemically reactive flow with liquid spray injection for the RQL combustor. The RQL combustor consists of an airblast atomizer fuel injector, a rich burn section, a converging connecting pipe, a quick mix zone, a diverging connecting pipe and a lean combustion zone. For computational efficiency, the combustor was split into two sub systems, i.e. the fuel nozzle/rich burn section and the quick mix/lean burn section. The current study investigates the effect of varying the mass flow rate split between the swirler passages for an equivalence ratio of 2.0 on fuel distribution, temperature distribution, and emissions for the fuel nozzle/rich burn section of an RQL combustor. The input conditions used in the study were chosen based on tests completed at LeRC. It is seen that optimizing these parameters can substantially improve combustor performance and reduce combustor emissions. The optimal mass flow rate split for reducing NOx emissions based on the numerical study was the same as found by experiment at LeRC.

Effects of Swirler Configurations on Flow Structures and Combustion Characteristics

2004 ◽  
Author(s):  
Guoqiang Li ◽  
Ephraim J. Gutmark
Keyword(s):  
Fuel Injection ◽  
Vortex Breakdown ◽  
Swirling Flow ◽  
Combustion Characteristics ◽  
Pollutant Emissions ◽  
Flow Structures ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Atmospheric Conditions ◽  
Fuel Injector

Modern gas turbine combustion technologies are driven by stringent regulations on pollutant emissions such as CO and NOx. A combustion system of multiple swirlers coupled with distributed fuel injection was studied as a new concept for reducing NOx emissions by application of Lean Direct Injection (LDI) combustion. The present paper investigates the effects of swirler configurations on the flow structures in isothermal flow and combustion cases using a multiple-swirlers fuel injector at atmospheric conditions. The swirling flow field within the combustor was characterized by a central recirculation zone formed after vortex breakdown. The differences between the tangential and axial velocity profiles, the shape of the recirculation zones and the turbulence intensity distribution for the different fuel injector configurations impacted the flame structure, the temperature distribution and the emission characteristics both for gaseous and liquid fuels. Co-swirling configuration was shown to have the lowest NOx emission level compared with the counter-swirling ones for both types of fuels with lower inlet temperature. In contrast to this, the swirl configuration had less effect on the combustion characteristics in the case of gaseous fuel with high air inlet temperature. The differences in NOx emissions were shown to be closely related to the Damkohler number or the degree to which the flame resembled well-mixed combustion, which is the foundation for LDI combustion.

Experimental Investigation of CH4 and C3H8 Combustion in a Packed Bed Burner

2011 ◽  
Author(s):  
H. B. Gao ◽  
Z. G. Qu ◽  
W. Q. Tao ◽  
T. J. Lu
Keyword(s):  
Equivalence Ratio ◽  
Packed Bed ◽  
Pollutant Emissions ◽  
Flame Stability ◽  
Nox Emissions ◽  
Flame Thickness ◽  
Porous Burner ◽  
Hc Emissions ◽  
The Stability ◽  
Stability Limits

The main object of this work is to investigate combustion in a two-layer packed beds porous burner, in particular, to study the effect of methane and propane on flame stability, pressure drop and pollutant emissions. The equivalence ratio of both methane and propane varied from 0.55 to 0.70. The results indicated that flame stability limits of both methane and propane enlarged with the increasing of equivalence ratio, however, the stability limits of methane is more widely than propane. The macroscopic flame shapes of methane and propane remains approximately the same but the later has a larger flame thickness. The NOx emissions are seen to be increased and the CO decreased with the equivalence ratio, HC emissions firstly decreased and then increased with the equivalence ratio for both methane and propane.

Flame Stability of Premixed Syngas-Air Flames Emitted From a Multi-Tube Fuel Injector

2015 ◽  
Author(s):  
Martin de La Torre ◽  
Sergio Maldonado ◽  
Sarzina Hossain ◽  
Norman Love ◽  
Ahsan Choudhuri
Keyword(s):  
Carbon Monoxide ◽  
Stability Region ◽  
Design Parameters ◽  
Flame Stability ◽  
Fuel Injector ◽  
Stability Range ◽  
Lean Premixed Combustion ◽  
Pressure Drops ◽  
Lean Premixed ◽  
The Stability

Multi-tube injectors have been emerging as a component that has potential to mitigate flame stability (flashback and blowout) and emission issues (NOx) associated with quick-start and fuel-flexible operations in lean premixed applications. Although several designs currently exist in literature, there currently does not exist a large source of information on the design parameters and exact dimensional configurations for these existing injectors. One cause of this may be due to the proprietary nature of this component. Furthermore, most multiport injector designs involve complex tubing and typically significant pressure drops across the exit face. In the present study a fuel injector component was designed keeping in mind simple injector geometry, possible operability limits of the flame, and turbulence intensity expected at the exit of the injector. This work presents the final design and the flame stability results from a multi-tube fuel-air injector. The injector operates on simulated syngas mixtures of hydrogen and carbon monoxide including 20–80, 30–70, and 40–60% representing the variation in the hydrogen found in syngas mixtures. Tests were completed for lean conditions ranging from equivalence ratios between 0.6 and 0.9. The experimental results showed that for the current injector design at an equivalence ratio of 0.6 a stable flame was not achieved for any of the fuel mixtures tested. It was also observed that the stability region of the syngas flame increased as equivalence ratios above 0.7 and the hydrogen concentration in syngas fuel increases with the 40–60% hydrogen-carbon monoxide mixture demonstrating the greatest stability region which can accommodate more than three times the stability range of other conditions. Results from this study may benefit others who are currently designing such fuel injectors for lean premixed combustion applications.

Improvement of Gas Turbine Injection Systems by Combined Experimental/Numerical Approach

2002 ◽  
Author(s):  
G. Riccio ◽  
P. Adami ◽  
F. Martelli ◽  
D. Cecchini ◽  
L. Carrai
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Fuel Injection ◽  
Numerical Approach ◽  
Combustion Stability ◽  
Pollutant Emissions ◽  
Injection System ◽  
Flame Stability ◽  
Fuel Injection System ◽  
Joint Application

An aerodynamic study for the premixing device of an industrial turbine gas combustor is discussed. The present work is based on a joint application of numerical CFD and experimental investigation tools in order to verify and optimize the combustor gaseous fuel injection system. The objective is the retrofit of an old generation gas turbine combustion chamber that is carried out considering new targets of NOx emission keeping the same CO and combustion stability performances. CFD has been used to compare different premixing duct configurations for improved mixing features. Experimental test has been carried out in order to assess the pollutant emissions, flame stability and pattern factor characteristics of the full combustion chamber retrofitted with the modified injection system.

scholarly journals A System to Enable Mixing Controlled Combustion With High Octane Fuels Using a Prechamber and High-Pressure Direct Injector

2021 ◽  
Vol 7 ◽  
Author(s):  
Adam B. Dempsey ◽  
Jared Zeman ◽  
Martin Wall
Keyword(s):  
High Pressure ◽  
Octane Number ◽  
Alternative Fuels ◽  
Combustion Engine ◽  
Pollutant Emissions ◽  
Renewable Fuels ◽  
Low Carbon ◽  
Fuel Injector ◽  
Si Engines ◽  
High Octane

The demand for transportation energy is growing and thus improving the efficiency and reducing the pollutant emissions from this energy sector is critical. Transportation has historically been powered by the internal combustion engine (ICE). Many alternative technologies are being evaluated to replace the ICE, such as hydrogen fuel cells and battery electrics. These technologies appear attractive at the vehicle-level but have many challenges regarding life cycle emissions and lack of infrastructure. A more pragmatic approach would be to use the current liquid fuels infrastructure with cleaner burning, renewable fuels that have the potential to be carbon neutral, such as low carbon alcohols (e.g., methanol, ethanol, propanol, and butanol). These alternative fuels tend to have a high-octane number, making them great candidates for conventional spark ignition (SI) engines. However, SI engines are plagued by several challenges when it comes to high load operation, such as pre-ignition, knock-limited peak torque, poor snap torque response, high levels of cyclic variability, and sensitivity to varying fuel properties. The objective of this research is to develop a technology that will allow high octane fuels to be utilized in engines and utilize robust mixing controlled combustion. The proposed technology is a system which utilizes an active prechamber in the shape of an annulus and a high-pressure direct fuel injector. The active prechamber and the high-pressure direct injector use the same liquid fuel, which could be any fuel that has relatively high volatility and high resistance to autoignition (i.e., high-octane number). The active prechamber is fired late in the compression stroke and hot jet flames are ejected from the prechamber. These jets ignite the direct injected fuel sprays near top dead center, establishing a mixing controlled combustion event. This will allow for robust operation across the full engine operating space with clean burning renewable fuels, without the shortcomings of SI engines regarding knock-limited operation and part load efficiency.

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