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Full-Text Articles in Engineering
Characterization Of The Thermal Transport Through A Temporally-Varying Ash Layer, Darron Palmer Cundick
Characterization Of The Thermal Transport Through A Temporally-Varying Ash Layer, Darron Palmer Cundick
Theses and Dissertations
Ash deposits in commercial coal-fired boilers frequently pose serious maintenance challenges and decrease thermal efficiency. A better understanding of fundamental thermal transport properties in ash deposits can help mitigate their negative effects. In order to characterize the thermal properties of boiler-side deposits, this work presents a thermal transport model and in-situ measurements of effective thermal conductivity in coal ash deposits. A simple model of the thermal transport through an ash deposit, with and with out slagging, was developed. The model approximates the deposit by dividing it into four regimes: particulate, sintered, solidified slag, and molten slag. The development of this …
The Decompositioning Of Volatile-Matter Of Tanjung Enim Coal By Using Thermogravimetry Analyzer (Tga), Nukman Nukman
The Decompositioning Of Volatile-Matter Of Tanjung Enim Coal By Using Thermogravimetry Analyzer (Tga), Nukman Nukman
Makara Journal of Technology
The Decompositioning of Volatile-Matter of Tanjung Enim Coal by using Thermogravimetry Analyzer (TGA). Coal is a nature material which a kind of energy source. The decompotition of coal could analyze by heat treated using thermogravimetry analyzer. The decomposition of the volatile matter for three kinds of Tanjung Enim coal could be known. The value of activation energy that be found diference, then for Semi Anthracite, Bitumonius and Sub Bituminous Coal, the initial temperatures are 60.8 oC, 70.7 oC, 97.8oC, and the last temperatures are 893.8 oC, 832 oC, 584.6oC.
A Mechanistic Investigation Of Nitrogen Evolution In Pulverized Coal Oxy-Fuel Combustion, Andrew John Mackrory
A Mechanistic Investigation Of Nitrogen Evolution In Pulverized Coal Oxy-Fuel Combustion, Andrew John Mackrory
Theses and Dissertations
Oxy-fuel combustion is an enabling technology for capture of CO2 from coal combustion, the economics of which depends strongly on the ability of the process to produce low NOX emissions. The literature contains many reports of lower NOX emissions from oxy-fuel combustion but the reasons for this are not fully understood. The objective of this work was to gain understanding of nitrogen evolution under pulverized coal oxy-fuel conditions. Pulverized coal was burned in a once-through, down-fired, laminar flow reactor. Nitrogen compounds and other combustion species were measured at the reactor centerline as a function of distance from the burner. Dry …
Mechanistic Investigation Of Ash Deposition In Pulverized-Coal And Biomass Combustion, Shrinivas Sadashiv Lokare
Mechanistic Investigation Of Ash Deposition In Pulverized-Coal And Biomass Combustion, Shrinivas Sadashiv Lokare
Theses and Dissertations
This investigation details the effects of fuel constituents on ash deposition through systematic experimental and theoretical analyses of fundamental particle experiments and a suite of fuels with widely varying inorganic contents and compositions. The experiments were carried out in the Multifuel Flow Reactor (MFR) at Brigham Young University. Fuels included several biomass fuels (straw, sawdust and mixtures of straw-sawdust with other additives such as Al(OH)3, CaCO3, etc.) and four commercially-used coals (Illinois#6, Powder River Basin – Caballo and Cordero, Blind Canyon, and Lignite – Beulah Zap). The data from the series of experiments quantitatively illustrate the effects of fuel properties, …
Measurements And Modeling Of Coal Ash Deposition In An Entrained-Flow Reactor, Ryan P. Blanchard
Measurements And Modeling Of Coal Ash Deposition In An Entrained-Flow Reactor, Ryan P. Blanchard
Theses and Dissertations
Coal plays a significant role in meeting the world's need for energy and will continue to do so for many years to come. Economic, environmental, and public opinion are requiring coal derived energy to be cleaner and operate in a more narrow window of operating conditions. Fouling and slagging of heat transfer surfaces continues to be a challenge for maintaining boiler availability and expanding the use of available fuels and operating conditions. The work incorporates existing information in the literature on ash deposition into a User-Defined Function (UDF) for a commercial comprehensive combustion and CFD code. Results from the new …
Hydraulic Fracturing In Underground Coal Mines, Dennis John Black, Naj Aziz
Hydraulic Fracturing In Underground Coal Mines, Dennis John Black, Naj Aziz
Faculty of Engineering and Information Sciences - Papers: Part A
The success of hydraulic fracturing application in stimulating gas drainage from coal seams is influenced by the ground stress conditions and the effective installation of straddled packers. A total of five holes were drilled in the Bulli Seam in a mine (Mine A) and tested for increased gas stimulation by hydraulic fracturing. Parameters examined included casing material integrity for cutability and ability to resist the external collapse during grouting and hydraulic fracturing. Changes made to the injecti on pressure, casing wall thickness, slot orientation (circumferential instead of axial) and controlled pressure release rate post-treatment improved the hydraulic fracturing treatment. However, …
Gas Drainage Improvement In Underground Coal Mines, Dennis John Black, Naj Aziz
Gas Drainage Improvement In Underground Coal Mines, Dennis John Black, Naj Aziz
Faculty of Engineering and Information Sciences - Papers: Part A
Effective gas management is vital to the success of the longwall mining in the Bulli seam, in the Southern Coalfield, Sydney Basin, NSW, Australia. The evolution of gas drainage methods and practices are discussed with respect to gas type, gas drainage lead time and prevailing geological conditions. Both underground to inseam drilling and surface to inseam drilling techniques are described at both pre and post-drainage conditions. Post-drainage of gas from longwall is discussed for its effectiveness, practicability and efficiency. The long term benefit of the method selected is examined with respect to gas capture efficiency. An alternative method of surface …
Improving Uis Gas Drainage In Underground Coal Mines, Dennis John Black, Naj Aziz
Improving Uis Gas Drainage In Underground Coal Mines, Dennis John Black, Naj Aziz
Faculty of Engineering and Information Sciences - Papers: Part A
Gas drainage is considered one of the most effective controls in preventing coal and gas outbursts. The advances in mining equipment technology over the last 20 years have led to a significant increase in coal mine production, resulting in increased coal mine gas emission during the coal extraction process. High gas emissions, if not effectively managed, may exceed the diluting capability of the mine's ventilation system, potentially exceeding the statutory limit, resulting in gas related production delays. The development of underground to inseam (UIS) gas drainage is discussed. The study is focused on a range of factors which impact gas …
Development Of Hydraulic Fracturing In High Stress Conditions In Australian Underground Coal Mines, Dennis John Black, Naj Aziz
Development Of Hydraulic Fracturing In High Stress Conditions In Australian Underground Coal Mines, Dennis John Black, Naj Aziz
Faculty of Engineering and Information Sciences - Papers: Part A
Hydraulic fracturing has been used extensively in the petroleum and coalbed methane industries as a means of improving access to the reservoir and thereby enhancing production. In the Australian coal mining industry there has been an aversion to the use of hydraulic fracturing. One of the main reasons for the lack of application of this technology has been the perceived risk of damage to the strata and the resulting impact on future mining operations. A number of Australian mines are progressing toward areas where gas drainage is becoming increasingly difficult and these mines are seriously considering the use of hydraulic …
The Evolution In Coal Mine Gas Extraction - A Response To Economic, Environmental And Community Pressures, Dennis John Black, Naj Aziz
The Evolution In Coal Mine Gas Extraction - A Response To Economic, Environmental And Community Pressures, Dennis John Black, Naj Aziz
Faculty of Engineering and Information Sciences - Papers: Part A
Effective gas management is vital to the success of the longwall mines operating in the Bulli seam, located in the Southern Sydney Basin, Australia. High gas emissions are characteristic of the region with specific gas emissions typically in the order of 30-45 m3/t. The mines that operate in this area have, since 1980, relied on the use of extensive underground to inseam (UIS) drilling to drain gas both ahead of advancing roadway development and following longwall coal extraction. With the ever increasing production capacity of modern mining machinery the UIS methods are struggling to drain sufficient gas from the coal …