ABSTRACT The thermodynamic properties of 1- and 2-phenyl substituted polyaromatic hydrocarbons have been measured and estimated under conditions relevant to heat transport applications almost to the critical point. Densities, vapor... more
ABSTRACT The thermodynamic properties of 1- and 2-phenyl substituted polyaromatic hydrocarbons have been measured and estimated under conditions relevant to heat transport applications almost to the critical point. Densities, vapor pressures, and heat capacity measurements were used to derive critical temperature, pressure, and density for the phenylnaphthalenes. The thermal and radiolytic stability of 1-phenylnaphthalene was examined using thermogravimetric analysis, differential scanning calorimetery, and gamma irradiation. Low melting point, low vapor pressure, high critical temperature, and resistance to thermal decomposition may make phenylnaphthalenes suitable for heat transfer applications up to 800 K, including power generation and separations processes.
Research Interests: Environmental Engineering, Chemical Engineering, Analytical Chemistry, Heat Transfer, Evaluation, and 15 moreHeat Transport, Pyrolysis, Stability, Power Generation, High Temperature, Energy Storage, Heat Capacity, Irradiation, Specific Heat, Concentrating Solar Power, Critical Point, Heat Transfer Fluid Mechanics CFD, Gamma Irradiation, Critical Temperature, and Polyaromatic hydrocarbons
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Résumé/Abstract A twin-screw extruder for the ITER pellet injection system is under development at the Oak Ridge National Laboratory. The extruder will provide a stream of solid hydrogen isotopes to a secondary section, where pellets are... more
Résumé/Abstract A twin-screw extruder for the ITER pellet injection system is under development at the Oak Ridge National Laboratory. The extruder will provide a stream of solid hydrogen isotopes to a secondary section, where pellets are cut and accelerated ...
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Page 1. American Institute of Aeronautics and Astronautics 1 Recapturing NERVA-Derived Fuels for Nuclear Thermal Propulsion AL Qualls1 Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 EF Hancock2 Tennessee ...
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An eight-shot pneumatic pellet injector has been developed for routine plasma fueling and optimization studies on short-pulse fusion experiments. Such experiments will require injection sequences of several pellets of various size over... more
An eight-shot pneumatic pellet injector has been developed for routine plasma fueling and optimization studies on short-pulse fusion experiments. Such experiments will require injection sequences of several pellets of various size over the discharge period. Two eight-shot injectors that are capable of producing and firing hydrogen and deuterium pellets have been built. The injectors are based on the pipe-gun concept,
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Research Interests: Computer Architecture, Decision Making, Human Factors, Parallel Processing, Control system, and 15 morePower Generation, Data acquisition, expert System, Nuclear reactor, Fault Isolation, Data Processing, Informing Science, Monitoring System, Annual Report, Experimental Data, Frequency Analysis, Nuclear Power Plant, Data Transmission, Expected Value, and Assistive Device
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Page 1. American Institute of Aeronautics and Astronautics 1 Recapturing NERVA-Derived Fuels for Nuclear Thermal Propulsion AL Qualls1 Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 EF Hancock2 Tennessee ...
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Plasma fueling via injection of solid hydrogenic pellets has expanded the operating range for tokamaks and stellarators to higher densities than attainable with gas puffing. Pellet injection has also resulted in improved plasma energy... more
Plasma fueling via injection of solid hydrogenic pellets has expanded the operating range for tokamaks and stellarators to higher densities than attainable with gas puffing. Pellet injection has also resulted in improved plasma energy confinement in tokamak discharges for which the pellet or pellets penetrate deep into the plasma core. The eight-shot pneumatic pellet injector described herein has been developed
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ABSTRACT
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ABSTRACT
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To address problems such as greenhouse gas emissions and energy security, the US is considering renewable resources, such as geothermal energy. Hydrothermal systems produce about 3000 MWe domestically; however, electricity may also come... more
To address problems such as greenhouse gas emissions and energy security, the US is considering renewable resources, such as geothermal energy. Hydrothermal systems produce about 3000 MWe domestically; however, electricity may also come from engineered geothermal systems (EGS) with siting issues such as low-permeability rock, limited water, and deep wells. Water use can be reduced with a power cycle that works efficiently with air cooling, using refrigerant mixtures. Heat extraction from the subsurface represents another aspect of geothermal water use because complex fluid-rock interactions affect heat transport and lifetime performance. These factors all contribute to the viability of EGS. 1 Abstract To address problems such as greenhouse gas emissions and energy security, the US is considering large investments in renewable sources, such as geothermal energy. Hydrothermal systems that have the advantages of plentiful heat, water, and permeable rock already produce about 3000 MWe in the U.S. and more systems are in development. However, the potential for generating electricity from geothermal resources extends well beyond the traditional sources in the Western US. The US Department of Energy is actively supporting research on enhanced and engineered systems that may overcome issues such as low-permeability rock, limited water, and deep well drilling. One issue with engineered geothermal systems is siting. Engineered sites can be located in areas where surface water is limited or water use rights are an issue. One way of minimizing water use is to have a power cycle that can work efficiently with air cooling rather than water cooling. Oak Ridge National Laboratory is developing more efficient power cycles that take advantage of the physical properties of mixtures of refrigerants in Brayton or organic Rankine cycles. Experiments on an air-cooled test loop employing 8% isobutane in CO 2 have given a respectable 13% cycle efficiency versus a 14.5% theoretical value for pure super-critical CO 2. These experiments are complemented by thermodynamic calculations that have demonstrated the effects of sizing of components in supercritical versus transcritical cycles for mixtures of supercritical CO 2 and SF 6. In these calculations, air temperatures are varied between 10 and 40°C to account for seasonal variability. Extraction of heat from the subsurface represents another aspect of water use in geothermal power. Better understanding of how complex fluid-rock interactions affect heat transport to the surface should facilitate decisions on siting and options to maintain or improve performance during the lifetime of the power plant. These factors contribute to the viability of engineered geothermal technology, especially in arid regions of the country.