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Articles 1 - 9 of 9
Full-Text Articles in Engineering
Performance Measurements Of Direct Air Injection In A Cavity-Based Flameholder For A Supersonic Combustor, Scott G. Edens
Performance Measurements Of Direct Air Injection In A Cavity-Based Flameholder For A Supersonic Combustor, Scott G. Edens
Theses and Dissertations
For several years the Air Force Research Lab Propulsion Directorate has been studying the difficulties in fueling supersonic combustion ramjet engines with hydrocarbon based fuels. Recent investigations have focused on the use of direct air injection into a directly-fueled cavity-based flameholder. Direct air injection has been shown qualitatively to be a valuable tool for improving cavity combustion. Little quantitative data is available that characterizes the performance of cavity-based flameholders. The objective of this research was to quantitatively determine the specific advantages and disadvantages of the direct air injection scheme. This was accomplished via intrusive probing into a supersonic free stream …
Effects Of Pressure On Coal Pyrolysis At High Heating Rates And Char Combustion, Dong Zeng
Effects Of Pressure On Coal Pyrolysis At High Heating Rates And Char Combustion, Dong Zeng
Theses and Dissertations
Clean coal technologies are now becoming popular because of their high efficiencies and minimal environmental impact. Higher operating pressures have been applied to clean coal technologies. The effect of pressure on coal pyrolysis and char combustion has been extensively studied but still remains to be further explored. The objective of this project was to characterize high pressure, high heating rate coal pyrolysis and char combustion, with emphasis on improving coal/char high pressure combustion models. A flat-flame burner was used in a high pressure laminar flow facility to conduct high temperature, high heating rate pyrolysis and combustion experiments for four coals. …
Biomass-Coal Co-Combustion: Opportunity For Affordable Renewable Energy, Larry Lin Baxter
Biomass-Coal Co-Combustion: Opportunity For Affordable Renewable Energy, Larry Lin Baxter
Faculty Publications
This investigation explores the reasons for and technical challenges associated with co-combustion of biomass and coal in boilers designed for coal (mainly pulverized coal) combustion. Biomass-coal co-combustion represents a near-term, low-risk, low-cost, sustainable, renewable energy option that promises reduction in net CO2 emissions, reduction in SOx and often NOx emissions, and several societal benefits. Technical issues associated with cofiring include fuel supply, handling and storage challenges, potential increases in corrosion, decreases in overall efficiency, ash deposition issues, pollutant emissions, carbon burnout, impacts on ash marketing, impacts on SCR performance, and overall economics. Each of these issues has been investigated and …
Effects Of Fuel Molecular Structure And Composition On Soot Formation In Direct-Injection Spray Flames, Kenth Ingemar Svensson
Effects Of Fuel Molecular Structure And Composition On Soot Formation In Direct-Injection Spray Flames, Kenth Ingemar Svensson
Theses and Dissertations
Numerous investigations have been conducted to determine the effect of fuel composition and molecular structure on particulate emissions using exhaust gas analysis, but relatively few measurements have been obtained in-cylinder or under conditions where fuel effects can be isolated from other variables. In this work, dimethoxymethane was used as the base fuel to produce a non-sooting flame in a constant volume combustion vessel at 1000 K, and a density of 16.6 kg/m3. A second fuel was then added incrementally to determine an incipient soot limit. Line-of-sight extinction measurements were used as the primary diagnostic tool to determine if a correlation …
Comprehensive Black Liquor Droplet Combustion Studies, Leong-Teng Ip
Comprehensive Black Liquor Droplet Combustion Studies, Leong-Teng Ip
Theses and Dissertations
Black liquor, a byproduct from pulp production, is burned in a recovery boiler to generate electricity and recover inorganic materials. Black-liquor-droplet combustion is fundamental to understanding and potentially improving recovery boiler performance. This investigation reports comprehensive experimental data collected for a suite of five liquors. All the data were collected with newly-designed laboratory equipment, several aspects of which are unique. Single droplets were suspended on a thermocouple and heated in a furnace. Simultaneous diameter (size and shape), internal and surface temperatures, surface emissivity, and mass were measured under various furnace temperatures and gas compositions. The images recorded by the cameras …
An Investigation Of The Autoignition Of Power Generation Gas Turbine Fuel Blends Using A Design Of Experiments Approach, Jaap De Vries
An Investigation Of The Autoignition Of Power Generation Gas Turbine Fuel Blends Using A Design Of Experiments Approach, Jaap De Vries
Electronic Theses and Dissertations
Natural gas has grown in popularity as a fuel for power generation gas turbines. However, changes in fuel composition are a topic of concern since fuel variability can have a great impact on the reliability and performance of the burner design. In particular, autoignition of the premixed fuel and air prior to entering the main burner is a potential concern when using exotic fuel blends. To obtain much-needed data in this area, autoignition experiments for a wide range of likely fuel blends containing CH4 mixed with combinations of C2H6, C3H8, C4H10, C5H12, and H2 were performed in a high-pressure shock …
Efficiency Of Heat Recovery Versus Maximum Catalyst Temperature In A Reverse-Flow Combustion Of Methane, Krzysztof Gosiewski
Efficiency Of Heat Recovery Versus Maximum Catalyst Temperature In A Reverse-Flow Combustion Of Methane, Krzysztof Gosiewski
Krzysztof Gosiewski
Results of simulations are presented concerning a reverse-flow reactor for the catalytic combustion of methane that occurs in coal-mine ventilation air. The simulations were performed for two types of catalyst: 12% MnO2/-Al2O3 and 0.5% Pd/-Al2O3. A special attention is given to maximum temperature of the catalyst bed in order to minimize occurrence of homogeneous combustion. The simulations revealed that there is a visible contradiction between efficiency of heat recovery aimed to high-pressure steam production and efforts to constraint maximum temperature in the bed.
Study Of The Effects Of Magnetic Field On The Properties Of Combustion Synthesized Iron Oxide Nanoparticles, Nagaraju Komuravelli
Study Of The Effects Of Magnetic Field On The Properties Of Combustion Synthesized Iron Oxide Nanoparticles, Nagaraju Komuravelli
LSU Master's Theses
Nanosized chain-like aggregates were developed in an iron pentacarbonyl-carbon monoxide (Fe(CO) 5 ¨C CO) air diffusion flame system. Magnetic field was applied around the diffusion flame using an electromagnet with an intensity of 0.4 Tesla. Transmission Electron Microscopy (TEM) analysis was performed to observe the behavior of the chains formed and to study the effect of magnetic field on these chains. These chain aggregates consist mainly of Fe2O3, which play a vital role in magnetic storage devices. Diffraction pattern analysis and X-ray Photon Spectroscopy (XPS) were carried out to confirm that the chain aggregates consist of mainly ¦Ã-Fe2O3. The effect …
Small Scale Incinerator For Biomass, With A Bubbling Fluidized Bed. I. Combustion Of Sewage Sludge, Jerzy Baron, Sylwia Chrupek, Stanislaw Kandefer, Malgorzata Olek, Malgorzata Pilawska, Jan Porzuczek, Jan Wrona, Witold Zukowski
Small Scale Incinerator For Biomass, With A Bubbling Fluidized Bed. I. Combustion Of Sewage Sludge, Jerzy Baron, Sylwia Chrupek, Stanislaw Kandefer, Malgorzata Olek, Malgorzata Pilawska, Jan Porzuczek, Jan Wrona, Witold Zukowski
Witold Zukowski
Results are presented, obtained when sewage sludge was burned in a purpose-designed industrial installation, comprising a 1.5 MW bubbling fluidised bed combustor. Dried sewage sludge was used in the tests. The combustion process was stable, and since the moisture content of the dried sludge was low, no auxiliary fuel was required. Analysis of the flue gases has shown that the concentrations of SO2 and NOx are somewhat elevated, on account of rather high combined S and N content in the sludge. The results have confirmed that the technological solutions used were correct and that they can be used for economically …