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Stimpson C.K.,Brigham Young University | Fry A.,Reaction Engineering International | Blanc T.,Brigham Young University | Tree D.R.,Brigham Young University
Proceedings of the Combustion Institute | Year: 2013

A two-color laser extinction method was used to collect measurements of soot volume fraction along a line of sight in air- and oxy-coal flames produced by two different burners. One was an Imjuiden block, variable swirl, 150 kW th burner in the Burner Flow Reactor (BFR) at Brigham Young University. The second was a fixed-swirl vane (30°), 40 kWth burner in the oxy-fuel combustor (OFC) at the University of Utah. In both burners, three stoichiometric ratios (SRs) and three oxygen volume fractions in the secondary oxidizer stream were investigated with measurements collected at three axial positions. In the OFC, two coals were investigated with simulated flue gas recirculation (FGR, O2 in CO2) and warm FGR. In the BFR, two coals were investigated, one with warm recycle (420°F) and the other with cold recycled flue gas. In the BFR, at high swirl (1.36), the flame was attached, and the amount of soot was found to correlate strongly with the secondary mass flow rate. Increasing flow rate produced shorter, more active flames and less soot indicating increased mixing. In the OFC, the flame was lifted. The air-fired flame was more lifted than the two oxy-fired flames (simulated FGR and warm FGR) and produced less soot. Soot for all flames decreased slightly with increased distance from the flame root where soot volume fraction was highest. The bituminous coal produced more soot than the sub-bituminous coal. Measured soot volume fractions ranged from 10 to 200 × 10-9. The data show that the local SR of the fuel rich region has a more significant impact than the overall SR and the type of oxidant (air, O2/FGR, or O2/CO2). © 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved. Source

Hower J.C.,University of Kentucky | Senior C.L.,Reaction Engineering International | Suuberg E.M.,Brown University | Hurt R.H.,Brown University | And 2 more authors.
Progress in Energy and Combustion Science | Year: 2010

The control of mercury in the air emissions from coal-fired power plants is an ongoing challenge. The native unburned carbons in fly ash can capture varying amounts of Hg depending upon the temperature and composition of the flue gas at the air pollution control device, with Hg capture increasing with a decrease in temperature; the amount of carbon in the fly ash, with Hg capture increasing with an increase in carbon; and the form of the carbon and the consequent surface area of the carbon, with Hg capture increasing with an increase in surface area. The latter is influenced by the rank of the feed coal, with carbons derived from the combustion of low-rank coals having a greater surface area than carbons from bituminous- and anthracite-rank coals. The chemistry of the feed coal and the resulting composition of the flue gas enhances Hg capture by fly ash carbons. This is particularly evident in the correlation of feed coal Cl content to Hg oxidation to HgCl2, enhancing Hg capture. Acid gases, including HCl and H2SO2 (at small concentrations) and the combination of HC1 and NO2, in the flue gas can enhance the oxidation of Hg. In this presentation, we discuss the transport of Hg through the boiler and pollution-control systems, the mechanisms of Hg oxidation, and the parameters controlling Hg capture by coal-derived fly ash carbons. © 2009 Elsevier Ltd. All rights reserved. Source

Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 149.93K | Year: 2015

Problem Statement: The evolution of hydraulic fracturing has enabled development of unconventional natural gas resources that previously would not have been economical. The volume of water required for these operations is a major concern. Industry is actively seeking methods to reduce water usage and increase the amount of gas recovered per unit of water used to stimulate the formation. There is substantial evidence that the rate and method of flowback of the fracturing fluid has a significant impact on the amount of water recovered and well productivity. Proposed Solution: REI proposes to develop a multiphase Computational Fluid Dynamics (CFD) model and an accompanying reduced order model (ROM) tool to predict flowback of the fracturing fluid from a well over time. The ROM tool will use a database of CFD solutions to provide quick estimates of the flowback rate and the potential impact on future gas production. The ROM will be designed to allow field operators and fracturing service companies to optimize the amount of water injected during stimulation, recover more of the injected water and increase the expected ultimate recovery of the natural gas in the formation. Phase I Work Plan REI will develop a Computational Fluid Dynamics (CFD) model of the Flowback process using the ANSYS/Fluent commercial CFD code. A database of CFD model solutions for flowback will be generated. A reduced order model (ROM) tool will be created using the database of CFD solutions. The CFD solutions and ROM tool will be benchmarked against field data. Commercial Applications and Other Benefits: The completed ROM tool will allow field operators and fracturing service companies to (a) optimize the flowback rate and recovery of the fracturing fluid (primarily water) before stimulating a well and (b) history match real flowback data with the model to better understand the geometry properties of the produced fractures. This will result in less water usage per fracturing job, higher recovery rates of water from the well, higher initial production rates and higher ultimate recovery of the resource. This will allow the United States to continue to lead in natural gas production while lowering the amount of water used. Key Words: hydraulic fracturing, flowback, well cleanup, unconventional Summary for Members of Congress This project will develop a computational tool designed to allow engineers to optimize the injection and recovery of water used in hydraulic fracturing operations. The proposed technology will improve the efficiency of natural gas production from unconventional resources and reduce the amount of water used.

Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 749.98K | Year: 2013

With the current state of world events, the threat of buried explosives used against military vehicles is more pronounced than ever before. The introduction of the MRAP and MTVR vehicles have helped mitigate this threat to a degree, but military personnel continue to suffer from both death and serious bodily injury as a result of IED/mine explosions. To address this need, improved comprehensive simulation capabilities are needed to help design improved safety components for vehicle occupants. The proposed effort, which builds on previous work performed under US Army funding, will develop next-generation simulation capabilities to better predict the effects of buried explosives on ground vehicles and occupants. Blast and soil modeling will be performed using advanced simulation tools developed as part of the DoE ASCI program at the University of Utah and the vehicles will be modeled with the LS-DYNA FE code. Occupant modeling will be performed using LS-DYNA. The final product of the Phase II will be a micro-coupled MPMICE-LS-DYNA model, which leverages the best capabilities of each simulation tool. Comparisons will be made between simulations of the MTVR exposed to a buried threat and live-fire test data for the same configuration.

Agency: Department of Defense | Branch: Navy | Program: STTR | Phase: Phase II | Award Amount: 750.00K | Year: 2011

The objective of the proposed Phase II STTR effort is to develop a validated computational tool to predict the afterburning of non-ideal munitions containing metal and hydrocarbon fuels. The activities outlined devise a well-coordinated collaboration among researchers from Reaction Engineering International (REI) and the State University of New York at Buffalo (UB). The activities proposed will build on the previous collaboration between REI and UB in modeling and simulation of advanced computational frameworks for abnormal thermal and mechanical environments. The modeling strategy proposed includes several unique features that are important for understanding and predicting the ignition of compressible multiphase flows. These effects include both heterogeneous and homogeneous particle reactions, particle compressibility, and a turbulence modeling approach that naturally includes effects of group combustion. The modeling will be housed into a new 3D supervisory simulation framework pioneered by REI for examining blast environments that includes support for complex geometries and a variety of explosives. It is anticipated that the final tool will be commercialized for both military and non-military customers to either design or better understand the blast loads from non-ideal explosives.

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