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Full-Text Articles in Mechanical 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 …
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 …
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 …