Characterization of a Low NOx Flameless Combustion Burner Using Natural Gas

2014 ◽  
Vol 66 (2) ◽  
Author(s):  
A. A. A. Abuelnuor ◽  
Mazlan A. Wahid ◽  
M. Osman
Keyword(s):  
Natural Gas ◽  
Combustion Process ◽  
Combustion Regime ◽  
Laboratory Scale ◽  
Pollutant Emission ◽  
Emission Measurement ◽  
Flameless Combustion ◽  
Auto Ignition ◽  
Combustion Emission ◽  
Gas Fuel

Flameless combustion is a method that has a great potential in reducing pollutant emission from combustion process. In this work, the operation and emission of a laboratory scale furnace under the flameless combustion regime using natural gas as a fuel was examined. In the experimental setup, the combustor was equipped with parallel jet burner systems with controlled gas fuel and oxidizer. Several ports have been integrated in the combustor to allow for temperature and combustion emission measurement. In the study, a comparison between flameless combustion with and without preheated combustion air has been made. The atmospheric air was heated to near the auto ignition temperature by a coil placed within the furnace assembly. The results show that flameless combustion mode could be obtained with and without preheated combustion air. The results also revealed that the laboratory scale furnace could successfully operate in flameless combustion regime using natural gas as fuel. In terms of emission, it was found that flameless combustion was more effective than the conventional combustion in reducing the rate of NOX emission.

Effects of Firing Mode on the Performance of Flameless Combustion: A Review Paper

2013 ◽  
Vol 388 ◽  
pp. 206-212
Author(s):  
Ali Abuelnuor Abdeen Abuelnuor ◽  
Mazlan Abdul Wahid ◽  
Aminuddin Saat ◽  
Mohsin M. Sies ◽  
Mohamed Osman Abdalla ◽  
...  
Keyword(s):  
Energy Savings ◽  
High Efficiency ◽  
Review Paper ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Flameless Combustion ◽  
Auto Ignition ◽  
Firing Mode ◽  
Industrial Heating

Flameless combustion is of a great interest since it simultaneously provides higher thermal efficiency together with controlling the pollutant emission such as NOX. This technology has been used to provide large energy savings in power system and industrial heating applications. In this technology, the preheat temperature of the combustion air must be higher than the auto-ignition temperature of the reactant mixture. In this review, papers concern the effect of firing mode to reduce pollutant emissions such as NOX emission and combustion efficiency for flameless combustion were reviewed. Summaries on the influences of the firing mode in the flameless combustion were presented, discussed and analyzed. The review concludes that all the previous studies have asserted that a parallel firing mode gives much lower pollutant emissions and high efficiency compared with staggered and counter modes.

scholarly journals Effect of hydrogen addition in diesel/natural gas dual-fuel combustion with late injection

2021 ◽  
Vol 312 ◽  
pp. 08005
Author(s):  
Antonio Caricato ◽  
Antonio Paolo Carlucci ◽  
Antonio Ficarella ◽  
Luciano Strafella
Keyword(s):  
Natural Gas ◽  
Conversion Efficiency ◽  
Early Stage ◽  
Combustion Process ◽  
Pollutant Emission ◽  
Dual Fuel ◽  
Injection Timing ◽  
Pilot Injection ◽  
Fuel Conversion ◽  
Hydrogen Addition

In a previous work, the effectiveness of late pilot injection on improving combustion behaviour – in terms of fuel conversion efficiency and pollutant emission levels – in a diesel/natural gas dual-fuel engine was assessed. Then, an additional set of experiments was performed, aiming at speeding up the combustion process possibly without penalizing NOx levels. Therefore, hydrogen was added to natural gas in a percentage equal to 10%. Results show that hydrogen addition has a significant effect on the combustion development specially during the early stage of combustion: ignition delay is shortened and combustion centre is advanced, while the combustion duration increases when pilot injection timing is set to conventional values, while remains basically unchanged for late timings. Fuel conversion efficiency is only slightly penalized when hydrogen is added. Moreover, it was confirmed that, in general, combustion strategy with late pilot injection timing does not penalize fuel conversion efficiency; indeed, in some cases, it actually increases. Concerning regulated emission levels, it is again proven that late pilot injection does not penalize pollutant production: the hydrocarbons and carbon monoxide reduce as pilot injection is delayed, probably due to the higher temperatures reached into the cylinder during most part of the expansion stroke. Moreover, adding hydrogen always reduces their levels. Concerning NOx, they are drastically reduced delaying pilot injection; as expected, hydrogen addition promotes NOx formation, but the increase, evident with conventional pilot injection timings, becomes marginal with late injection strategy. Therefore, combustion strategy performance with late pilot injection in dual-fuel diesel/natural gas combustion conditions can be further improved with 10% hydrogen addition to natural gas.

Stability of Flames Close to Auto-Ignition Temperatures Generated by Extreme Separated Gas-Air Inlets

2000 ◽  
Vol 123 (1) ◽  
pp. 50-58 ◽  
Author(s):  
O. Piepers ◽  
P. P. Breithaupt ◽  
A. B. N. van Beelen
Keyword(s):  
Natural Gas ◽  
Flue Gas ◽  
Combustion Regime ◽  
Nitric Oxides ◽  
Flow Conditions ◽  
Transfer Rates ◽  
Auto Ignition ◽  
High Temperature Processes ◽  
The Stability ◽  
Gas Recirculation

Stabilization of the combustion of natural gas in high-temperature processes by using the auto-ignition of the fuel when mixed with highly preheated air is well known and has found application on many occasions. Reasonably strong internal flue gas recirculation not only reduces nitric oxides emissions and increases convective heat transfer rates, but reduces local flame temperatures such that the flames become almost invisible for a human eye. This combustion regime is called flameless oxidation. Gasunie’s interest in this technique of flameless oxidation has two aspects. First, it must be clear which geometrical restrictions and flow conditions/disturbances in the oven or furnace have to be taken into account. Secondly, the use of this principle requires the auto-ignition of the fuel. This raises the question as to the stability of the combustion at or near the limits for auto-ignition. The study which is presented here reports on the stability of the oxidation process at these limiting conditions. These conditions are minimum load to the combustion system and minimum temperature in a combustion chamber. The stability has been determined using some “burner”/furnace combinations in which the distance between nozzles for air and natural gas have been varied.

scholarly journals Analysis of combustion process in industrial gas engines powered with high methane and nitrified low-calorific gases

2013 ◽  
Vol 152 (1) ◽  
pp. 42-50
Author(s):  
Jakub ROJEWSKI ◽  
Rafał ŚLEFARSKI ◽  
Jacek WAWRZYNIAK
Keyword(s):  
Natural Gas ◽  
Combustion Process ◽  
Numerical Code ◽  
Numerical Computations ◽  
Gas Combustion ◽  
Elementary Reactions ◽  
Natural Gas Transmission ◽  
Gas Fuel ◽  
Natural Gas Combustion

The paper presents the results of an investigation of gas engines used in the Polish system of natural gas transmission. The investigation concerned both four-stroke and two-stroke engines. The engines were fed with two kinds of gas fuel – low-calorific natural gas containing 54.5 % of methane, and with high-methane (up to 95 %) natural gas. Combustion in both types of engines with different methods of mixture supply into the cylinder was analysed for different parameters. The paper also presents numerical computations of basic physical values characterizing combustion of gas fuels in engines. The computations were made with Cantera numerical code based on the mechanism of elementary reactions occurring while burning methane GRI 3.0 for various molar fractions of methane in the gas fuel.

221 Study on the Engine Combustion Process of Natural-Gas Fuel

2014 ◽  
Vol 2014.89 (0) ◽  
pp. _2-22_
Author(s):  
Daiki HAYAMA ◽  
Sei SATO ◽  
Masahiro SHIOJI
Keyword(s):  
Natural Gas ◽  
Combustion Process ◽  
Engine Combustion ◽  
Gas Fuel

Emissions and dynamic stability of the flameless combustion regime using hydrogen blends with natural gas

2021 ◽  
Vol 46 (1) ◽  
pp. 1246-1258
Author(s):  
Fabián E. Cano Ardila ◽  
Julian E. Obando Arbeláez ◽  
Andrés A. Amell Arrieta
Keyword(s):  
Natural Gas ◽  
Dynamic Stability ◽  
Combustion Regime ◽  
Flameless Combustion

Review of Numerical Studies on NOx Emission in the Flameless Combustion

2013 ◽  
Vol 388 ◽  
pp. 235-240 ◽  
Author(s):  
Ali Abuelnuor Abdeen Abuelnuor ◽  
Mazlan Abdul Wahid ◽  
Aminuddin Saat ◽  
Mohsin M. Sies ◽  
M. Kabashi Elbasheer ◽  
...  
Keyword(s):  
Thermal Efficiency ◽  
Ignition Temperature ◽  
Fossil Fuels ◽  
Pollutant Emission ◽  
Preheat Temperature ◽  
Flameless Combustion ◽  
Pollution Emission ◽  
Numerical Studies ◽  
Auto Ignition ◽  
Source Of Pollution

Today one source of pollution emission in the combustion of fossil fuels is the formation of nitrogen oxides. To solve this problem many technologies have been introduced such as flameless combustion. Flameless combustion is of a great interest since it simultaneously provides higher thermal efficiency together with controlling the pollutant emission such as NOX. In this technology, the preheat temperature of the combustion air must be higher than the auto-ignition temperature of the reactant mixture. In this study, papers showing the numerical studies on the flameless combustion to reduce NOX emission are presented.

Numerical and Experimental Study of the Effect of Injected CO2 Flow on the Stability of Flameless Combustion

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Cristian C. Mejía ◽  
Alex M. García ◽  
Julián E. Obando ◽  
Andrés A. Amell
Keyword(s):  
Thermal Power ◽  
Radiation Heat Transfer ◽  
Combustion Process ◽  
Dilution Effect ◽  
Combustion Regime ◽  
Co2 Injection ◽  
Flameless Combustion ◽  
Ansys Fluent ◽  
Excess Air ◽  
The Stability

Abstract The effect of the injection of externally sourced carbon dioxide (CO2) on the stability of the flameless combustion regime was evaluated numerically and experimentally, taking temperature uniformity and pollution emissions (NO and CO) as criteria. The flameless combustion regime was studied in a lab-scale furnace fueled with natural gas (NG) at a thermal power of 20 kW based on the low heating value (LHV). The CO2 was injected into the lower part of the furnace to directly affect the reaction zone. Computational fluid dynamics (CFD) simulations were performed using the ansys-fluent software. The models used to describe the turbulence, the radiation heat transfer, and the turbulence–chemistry interaction were the standard k–ɛ model, discrete ordinate model (DOM), and eddy dissipation concept (EDC) model, respectively. The NG oxidation was described with a seven-step global reaction mechanism with the EDC model. Three excess air conditions were analyzed, 20%, 25%, and 30%, combined with various CO2 injection flows. At 30% excess air, the flame exhibited destabilization without any CO2 injection. Adding CO2 attenuates the destabilization because of the dilution effect. Increasing either the CO2 or excess air flow resulted in a considerable decrease in the global temperature of the process, consequently producing an increase in CO emissions and a decrease in NO emissions. Finally, for the conditions studied, increasing the mass flow of externally sourced CO2 did not destabilize the flameless combustion regimen. This result shows the potential of the implementation of flameless combustion in industrial processes where CO2 is releasing as a result of a reaction external to the combustion process, such as cement, ammonia, or lime production among others.

Igniter Testing for sCO2 Oxy-Combustion

2019 ◽  
Author(s):  
Kelsi M. Katcher ◽  
Timothy C. Allison ◽  
Shane Coogan ◽  
Yuin Jin ◽  
Chansun Lim ◽  
...  
Keyword(s):  
Natural Gas ◽  
Carbon Capture ◽  
High Efficiency ◽  
Combustion Process ◽  
Spark Ignition ◽  
Liquid Fuels ◽  
Preliminary Review ◽  
Laser Ignition ◽  
Auto Ignition ◽  
Constant Volume Combustion Chamber

Abstract Utilizing direct-fired sCO2 oxy-combustion is attractive for power generation applications because of the cycle’s inherent carbon capture, high efficiency, and small machinery footprint. However, there is a large amount of uncertainty regarding the combustion process of natural gas in carbon dioxide diluent at supercritical pressures. One such area of uncertainty is in regards to the ignition system. The performance of most common ignition systems is not proven at the elevated pressures and densities typical of these cycles. This paper presents an evaluation and down-selection of potential ignition systems considered for a sCO2 oxy-combustor igniter. The ignition systems considered include spark ignition, laser ignition, heating element auto-ignition, external preheat auto-ignition, ignition using solid or liquid fuels, and external torch ignition. After a preliminary review, spark ignition and laser ignition were chosen for system reliability and repeatability. To further quantify the practicality of each system, a spark igniter and laser igniter were lab-scale tested to determine breakdown energies associated with these igniters. The spark igniter was tested using gaseous CO2 and SF6 (to attain higher fluid densities). The laser igniter was tested using supercritical CO2 and gaseous CO2. An additional round of testing was conducted using the laser igniter in a constant volume combustion chamber (CVCC). Natural gas was combusted with oxygen in varying levels of CO2 dilution to determine the required laser power for stable, reliable ignition and to quantify the high dilution flammability limit. Based on these test results, a laser igniter was selected as the most practical option for high-pressure sCO2 combustor ignition.

scholarly journals Influence of Air Infiltration on Combustion Process Changes in a Rotary Tilting Furnace

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1292
Author(s):  
Róbert Dzurňák ◽  
Augustin Varga ◽  
Gustáv Jablonský ◽  
Miroslav Variny ◽  
Réne Atyafi ◽  
...  
Keyword(s):  
Natural Gas ◽  
Relevant Literature ◽  
Combustion Process ◽  
Laboratory Scale ◽  
Subsequent Increase ◽  
Fuel Savings ◽  
Air Infiltration ◽  
Gas Consumption ◽  
Natural Gas Consumption ◽  
Gap Width

Air infiltration into the combustion chambers of industrial furnaces is an unwanted phenomenon causing loss of thermal efficiency, fuel consumption increase, and the subsequent increase in operating costs. In this study, a novel design for a rotary tilting furnace door with improved construction features is proposed and tested experimentally in a laboratory-scale furnace, aimed at air infiltration rate reduction by decreasing the gap width between the static furnace door and the rotating body. Temperatures in the combustion chamber and oxygen content in the dry flue gas were measured to document changes in the combustion process with the varying gap width. Volumetric flow values of infiltrating air calculated based on measured data agree well with results of numerical simulations performed in ANSYS and with the reference calculation procedure used in relevant literature. An achievable air infiltration reduction of up to 50% translates into fuel savings of around 1.79 to 12% of total natural gas consumption of the laboratory-scale furnace. The average natural gas consumption increase of around 1.6% due to air infiltration into industrial-scale furnaces can thus likewise be halved, representing fuel savings of almost 0.3 m3 per ton of charge.

Sign in / Sign up

Export Citation Format

Share Document