Investigation on the Flame Extinction Limit of Fuel Blends

2005 ◽  
Author(s):  
Mahesh Subramanya ◽  
Ahsan Choudhuri
Keyword(s):  
Flame Extinction ◽  
Fuel Blends ◽  
Extinction Limit

Flame Extinction Limits of H2‐CO Fuel Blends

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Ahsan R. Choudhuri ◽  
Mahesh Subramanya ◽  
Subramanyam R. Gollahalli
Keyword(s):  
Laminar Flame ◽  
Critical Value ◽  
Mean Value ◽  
Flame Velocity ◽  
Flame Extinction ◽  
Hydrogen Fuel ◽  
Fuel Blend ◽  
Fuel Blends ◽  
Extinction Limit ◽  
The Mean

The flame extinction limits of syngas (H2‐CO) flames were measured using a twin-flame counterflow burner. Plots of extinction limits (%f: volumetric percent of fuel in air) versus global stretch rates were generated at different fuel blend compositions and were extrapolated to determine the flame extinction limit corresponding to an experimentally unattainable zero-stretch condition. The zero-stretch extinction limit of H2‐CO mixtures decreases with the increase in H2 concentration in the mixture. The average difference between the measured flame extinction limit and the Le Chatelier’s calculation is around 7% of the mean value. The measured OH chemiluminescence data indicates that regardless of blend composition the OH radical concentration reduces to a critical value prior to the flame extinction. The measured laminar flame velocity close to the extinction indicates that regardless of fuel composition, the premixed flame of hydrogen fuel blends extinguishes when the mixture laminar flame velocity falls below a critical value.

In-Situ O2 Sensor Demonstration in a Pressurized Lean Premixed Combustion Rig

2004 ◽  
Author(s):  
Douglas L. Straub ◽  
Jimmy D. Thornton ◽  
Geo. A. Richards ◽  
Doug Simmers ◽  
Pavel Shuk ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Oxygen Sensors ◽  
In Situ Monitoring ◽  
Sensor Technology ◽  
Excess Oxygen ◽  
Flame Extinction ◽  
Extinction Limit ◽  
Lean Premixed

State-of-the-art gas turbines engines continuously strive for higher cycle efficiencies and lower pollutant emissions. The gas turbine combustor is critical for achieving these goals, and operation near the lean extinction limit is necessary. Slight changes in the flow splits (fuel and/or air) can lead to unexpected flame extinction, or other operational issues such as combustion oscillations. Operating these gas turbine combustors near the flame extinction limit could be improved if acceptable in-situ sensors for the combustion section were commercially available. Although exhaust gas oxygen sensors are commonly used in other combustion processes including large utility boilers and automobiles, the use of in-situ oxygen sensors in gas turbine engines has been limited. This paper will describe the results from rig tests in a pressurized lean premixed combustor. The O2 sensor technology used in these tests is commercially available for industrial boiler applications which typically operate near atmospheric pressure and oxygen levels that range from 0–3% of the effluent. In modern gas turbines, however, the amount of excess oxygen is considerably higher. These high levels of excess oxygen result in low level signals from the O2 sensor, which creates concern for in-situ monitoring in gas turbines. The results indicate that this sensor technology will operate at elevated pressure and at high levels of excess oxygen in the process gas suggesting possible application as an operational and diagnostic tool. Data will be presented to show the effects of different operating variables such as pressure, inlet-air temperature, heat-release, and fuel-air ratio.

SPRAY FLAMES OF THREE-COMPONENT FUEL BLENDS IN A POROUS MEDIA BURNER AT LEAN CONDITIONS

2017 ◽  
Author(s):  
Flavio I. Moreno ◽  
Ramkumar N. Parthasarathy ◽  
Subramanyam R. Gollahalli
Keyword(s):  
Porous Media ◽  
Fuel Blends ◽  
Spray Flames ◽  
Porous Media Burner ◽  
Lean Conditions

EMISSIONS IN TWO-STROKE ENGINE OPERATING WITH NON- COMMERCIAL FUEL BLENDS (GASOLINE/ETHANOL)

2016 ◽  
Author(s):  
Robson Leal da Silva ◽  
Jean Paulo Carneiro Junior ◽  
Marcelo Mendes Vieira
Keyword(s):  
Fuel Blends ◽  
Stroke Engine ◽  
Commercial Fuel
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