Monthly energy review, December 1995 (open access)

Monthly energy review, December 1995

This publication presents an overview of EIA`s recent monthly energy statistics. The statistics cover the major activities of US production, consumption, trade, stocks, and prices for petroleum, natural gas, coal, electricity, and nuclear energy. Also included are international energy and thermal and metric conversion factors. An energy preview of alternative fuel providers vehicle fleet surveys is included. The publication is intended for use by members of Congress, Federal and State agencies, energy analysts, and the general public.
Date: December 21, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Pressure Induced Phase Transformation of Pb(Zr(0.95)Ti(0.05))O(3) Based Ceramics: Grain Size Dependence (open access)

Pressure Induced Phase Transformation of Pb(Zr(0.95)Ti(0.05))O(3) Based Ceramics: Grain Size Dependence

A substantial decrease in hydrostatic ferroelectric (FE) to antiferroelectric (AFE) transformation pressure was measured for Pb(Zr{sub 0.949}Ti{sub 0.051}){sub 0.989}Nb{sub 0.0182}O{sub 3} ceramics with decreasing grain size. The 150 MPa decrease in hydrostatic FE to AFE transformation pressure over the grain size range of 8.5 {micro}m to 0.7{micro}m was shown to be consistent with enhanced internal stress with decreasing grain size. Further, the Curie Point decreased and the dielectric constant measured at 25 C increased with decreasing grain size. All three properties: dielectric constant magnitude, Curie point shift and FE to AFE phase transformation pressure were shown to be semi-quantitatively consistent with internal stress differences on the order of 100 MPa. Calculations of Curie point shifts from the Clausius-Clapeyron equation, using internal stress levels derived from the hydrostatic depoling characteristics, were consistent with measured values.
Date: December 21, 1999
Creator: Tuttle, Bruce A.; Voigt, James A.; Scofield, Timothy W.; Aselage, Terrence L.; Rodriguez, Mark A.; Yang, Pin et al.
Object Type: Article
System: The UNT Digital Library
Monte Carlo Simulations of Phosphate Polyhedron Connectivity in Glasses (open access)

Monte Carlo Simulations of Phosphate Polyhedron Connectivity in Glasses

Monte Carlo simulations of phosphate tetrahedron connectivity distributions in alkali and alkaline earth phosphate glasses are reported. By utilizing a discrete bond model, the distribution of next-nearest neighbor connectivities between phosphate polyhedron for random, alternating and clustering bonding scenarios was evaluated as a function of the relative bond energy difference. The simulated distributions are compared to experimentally observed connectivities reported for solid-state two-dimensional exchange and double-quantum NMR experiments of phosphate glasses. These Monte Carlo simulations demonstrate that the polyhedron connectivity is best described by a random distribution in lithium phosphate and calcium phosphate glasses.
Date: December 21, 1999
Creator: ALAM,TODD M.
Object Type: Article
System: The UNT Digital Library
Plasma analysis and diagnostics for high efficiency amorphous solar cell production. Final report (open access)

Plasma analysis and diagnostics for high efficiency amorphous solar cell production. Final report

This is a project that sought to improve the amorphous silicon-germanium (SiGe) thin film deposition process in the production of solar cells. To accomplish this, the electron cyclotron resonance (ECR) plasma discharge, employed for the thin film deposition, was modified. Changes in the parameters of the plasma were monitored with diagnostic techniques, similar to those used in fusion plasma studies. That was the primary contribution from ORNL. Only one phase was contained in the statement of work, with the following tasks: (1) Develop a detailed program for plasma characterization. (2) Carry-out plasma modeling and analysis to support deposition systems design. (3) Operate experimental deposition systems for the purpose of plasma characterization. (4) Analyze data. (5) Modify deposition as directed by measurements. (6) This final report, which was deemed to be the only deliverable of this small project. And while the modified ECR discharge did not show measurable improvement of the conditions relevant to the deposition process, much was learned about the plasma parameters in the process. Some ideas on alternative designs are being discuss and funding options for testing such designed are being sought.
Date: December 21, 1994
Creator: Klepper, C.C.
Object Type: Report
System: The UNT Digital Library
Development of integrated mechanistically-based degradation-mode models for performance assessment of high-level waste containers (open access)

Development of integrated mechanistically-based degradation-mode models for performance assessment of high-level waste containers

Alloy 22 [UNS NO60221] is now being considered for construction of high level waste containers to be emplaced at Yucca Mountain and elsewhere. In essence, this alloy is 20.0-22.5% Cr, 12.5-14.5% MO, 2.0-6.0% Fe, 2.5-3.5% W, with the balance being Ni. Other impurity elements include P, Si, S, Mn, Co and V. Cobalt may be present at a maximum concentration of 2.5%. Detailed mechanistic models have been developed to account for the corrosion of Alloy 22 surfaces in crevices that will inevitably form. Such occluded areas experience substantial decreases in pH, with corresponding elevations in chloride concentration. Experimental work has been undertaken to validate the crevice corrosion model, including parallel studies with 304 stainless steel.
Date: December 21, 1998
Creator: Estill, J. C.; Farmer, J. C.; Gordon, S. R. & McCright, R. D.
Object Type: Article
System: The UNT Digital Library
Near-Field Hydrology Data Package for the Immobilized Low-Activity Waste 2001 Performance Assessment (open access)

Near-Field Hydrology Data Package for the Immobilized Low-Activity Waste 2001 Performance Assessment

Lockheed Martin Hanford Company (LMHC) is designing and assessing the performance of disposal facilities to receive radioactive wastes that are currently stored in single- and double-shell tanks at the Hanford Site. The preferred method for disposing of the portion that is classified as immobilized low-activity waste (ILAW) is to vitrify the waste and place the product in new-surface, shallow land burial facilities. The LMHC project to assess the performance of these disposal facilities is the Hanford ILAW Performance Assessment (PA) Activity. The goal of this project is to provide a reasonable expectation that the disposal of the waste is protective of the general public, groundwater resources, air resources, surface water resources, and inadvertent intruders. Achieving this goal will require prediction of contaminant migration from the facilities. This migration is expected to occur primarily via the movement of water through the facilities and the consequent transport of dissolved contaminants in the pore water of the vadose zone. Pacific Northwest National Laboratory (PNNL) assists LMHC in its performance assessment activities. One of PNNL's tasks is to provide estimates of the physical, hydraulic, and transport properties of the materials comprising the disposal facilities and the disturbed region around them. These materials are referred …
Date: December 21, 1999
Creator: Meyer, PD & Serne, RJ
Object Type: Report
System: The UNT Digital Library
High-resolution electron microscopy studies of the precipitation of copper under neutron irradiation in an Fe-1.3WT % Cu alloy. (open access)

High-resolution electron microscopy studies of the precipitation of copper under neutron irradiation in an Fe-1.3WT % Cu alloy.

We have studied by electron microscopy the copper-rich precipitates in an Fe-1.3wt%Cu model alloy irradiated with neutrons to doses of 8.61 x 10{sup {minus}3} dpa and 6.3 x 10{sup {minus}2} dpa at a temperature of {approximately}270 C. In the lower dose material a majority (ca. 60%)of the precipitates visible in high-resolution electron microscopy were timed 9R precipitates of size {approximately}2-4 nm, while ca. 40% were untwinned. In the higher dose material, a majority (ca. 75%) of visible precipitates were untwinned although many still seemed to have a 9R structure. The average angle {alpha} between the herring-bone fringes in the twin variants was measured as 125{degree}, not the 129{degree} characteristic of precipitates in thermally-aged and electron-irradiated material immediately after the bcc{r_arrow}9R martensitic transformation. We argue that these results imply that the bcc{r_arrow}9R transformation of small (<4 nm) precipitates under neutron irradiation takes place at the irradiation temperature of 270 C rather than after subsequent cooling. Preliminary measurements showed that precipitate sizes did not depend strongly on dose, with a mean diameter of 3.4 {+-} 0.7 nm for the lower dose material, and 3.0 {+-} 0.5 nm for the higher dose material. This result agrees with the previous assumption that the lack …
Date: December 21, 1998
Creator: Nicol, A. C.
Object Type: Article
System: The UNT Digital Library
Geotechnical Issues in Total System Performance Assessments of Yucca Mountain (open access)

Geotechnical Issues in Total System Performance Assessments of Yucca Mountain

A Total System Performance Assessment (TSPA) of Yucca Mountain consists of integrated sub-models and analyses of natural and engineered systems. Examples of subsystem models include unsaturated-zone flow and transport, seepage into drifts, coupled thermal hydrologic processes, transport through the engineered barrier system, and saturated-zone flow and transport. The TSPA evaluates the interaction of important processes among these subsystems, and it determines the impact of these processes on the overall performance measures (e.g., dose rate to humans). This paper summarizes the evaluation, abstraction, and combination of these subsystem models in a TSPA calculation, and it provides background on the individual TSPA subsystem components that are most directly impacted by geotechnical issues. The potential impact that geologic features, events, and processes have on the overall performance is presented, and an evaluation of the sensitivity of TSPA calculations to these issues is also provided.
Date: December 21, 1999
Creator: HO,CLIFFORD K.; HOUSEWORTH,JIM & WILSON,MICHAEL L.
Object Type: Article
System: The UNT Digital Library
Properties and orientation of antiferroelectric lead zirconate thin films grown by MOCVD. (open access)

Properties and orientation of antiferroelectric lead zirconate thin films grown by MOCVD.

Single-phase polycrystalline PbZrO{sub 3} (PZ) thin films, 3000-6000 {angstrom} thick, have been grown by metal-organic chemical vapor deposition (MOCVD) on (111)Pt/Ti/SiO{sub 2}/Si substrates at {approximately}525 C. X-ray diffraction analysis indicated that the PZ films grown on (111)Pt/Ti/SiO{sub 2}/Si (Pt/Ti/Si) showed preferred pseudocubic (110) orientation. In contrast, PZ films grown on 150 {angstrom} thick PbTiO{sub 3} (PT) template layers exhibited a pseudocubic (100) preferred orientation, and PZ films deposited on TiO{sub 2} template layers consisted of randomly oriented grains. The PZ films grown on Pt/Ti/Si with or without templates exhibited dielectric constants of 120-200 and loss tangents of 0.03-0.01. The PZ films with (110) orientation exhibited an electric-field-induced transformation from the antiferroelectric phase to the ferroelectric phase with a polarization of {approx}34 {micro}C/cm{sup 2}, and the energy that was stored during switching was 7.1 J/cm{sup 3}. The field needed to excite the ferroelectric state and that needed to revert to the antiferroelectric state were 350 and 250 kV/cm, respectively. Relationships between the MOCVD processing and the film microstructure and properties are discussed.
Date: December 21, 1998
Creator: Chen, N.
Object Type: Article
System: The UNT Digital Library
Geologic Data Package for 2001 Immobilized Low-Activity Waste Performance Assessment (open access)

Geologic Data Package for 2001 Immobilized Low-Activity Waste Performance Assessment

This database is a compilation of existing geologic data from both the existing and new immobilized low-activity waste disposal sites for use in the 2001 Performance Assessment. Data were compiled from both surface and subsurface geologic sources. Large-scale surface geologic maps, previously published, cover the entire 200-East Area and the disposal sites. Subsurface information consists of drilling and geophysical logs from nearby boreholes and stored sediment samples. Numerous published geological reports are available that describe the subsurface geology of the area. Site-specific subsurface data are summarized in tables and profiles in this document. Uncertainty in data is mainly restricted to borehole information. Variations in sampling and drilling techniques present some correlation uncertainties across the sites. A greater degree of uncertainty exists on the new site because of restricted borehole coverage. There is some uncertainty to the location and orientation of elastic dikes across the sites.
Date: December 21, 1999
Creator: Reidel, S. P. & Horton, D. G.
Object Type: Report
System: The UNT Digital Library
Fate of neptunium in an anaerobic, methanogenic microcosm. (open access)

Fate of neptunium in an anaerobic, methanogenic microcosm.

Neptunium is found predominantly as Np(IV) in reducing environments, but Np(V) in aerobic environments. However, currently it is not known how the interplay between biotic and abiotic processes affects Np redox speciation in the environment. In order to evaluate the effect of anaerobic microbial activity on the fate of Np in natural systems, Np(V) was added to a microcosminoculated with anaerobic sediments from a metal-contaminated fresh water lake. The consortium included metal-reducing, sulfate-reducing, and methanogenic microorganisms, and acetate was supplied as the only exogenous substrate. Addition of more than 10{sup {minus}5} M Np did not inhibit methane production. Total Np volubility in the active microcosm, as well as in sterilized control samples, decreased by nearly two orders of magnitude. A combination of analytical techniques, including VIS-NIR absorption spectroscopy and XANES, identified Np(IV) as the oxidation state associated with the sediments. The similar results from the active microcosm and the abiotic controls suggest that microbian y produced Mn(II/HI) and Fe(II) may serve as electron donors for Np reduction.
Date: December 21, 1998
Creator: Banaszak, J. E.
Object Type: Article
System: The UNT Digital Library
Incorporation of radionuclides from the electrometallurgical treatment of spent fuel into a ceramic waste form. (open access)

Incorporation of radionuclides from the electrometallurgical treatment of spent fuel into a ceramic waste form.

An electrometallurgical process is being developed at Argonne National Laboratory to treat spent metallic nuclear fuel. In this process, the spent nuclear fuel is electrorefined in a molten salt to separate uranium from the other constituents of the fuel. The treatment process generates a contaminated chloride salt that is incorporated into a ceramic waste form. The ceramic waste form, a composite of socialite and glass, contains the fission products (rare earths, alkalis, alkaline earth metals, and halides) and transuranic radionuclides that accumulated in the electrorefiner salt. These radionuclides are incorporated into zeolite A, which can fully accommodate the salt in its crystal structure. The radionuclides are incorporated into the zeolite by high-temperature blending or by ion exchange. In the blending process the salt and zeolite are simply tumbled together at >450 C (723 K), but in the ion exchange process, which yields a product more highly concentrated in fission products, the molten salt is passed through a bed of the zeolite. In either case, the salt-loaded zeolite A is mixed with glass frit and hot isostatically pressed to produce a monolithic leach resistant waste form. Zeolite is converted to sodalite during hot pressing. This paper presents experimental results on the …
Date: December 21, 1998
Creator: Pereira, C.
Object Type: Article
System: The UNT Digital Library
Investigation of the potential impacts from tritium soil contamination in the CP-5 yard. (open access)

Investigation of the potential impacts from tritium soil contamination in the CP-5 yard.

Based on a review of available data, significant contributions to low-level tritium soil contamination in the CP-5 yard have been made by airborne tritium fallout and rainout from the CP-5 ventilation system stack. Based on the distribution of tritium in the yard, it is also likely that leaks in secondary system piping which lead to the cooling towers were a significant contributor to tritium in CP-5 yard subsurface soil. Based on the foregoing analysis, low-level tritium contamination will not prohibit the release of the yard for unrestricted use in the future. Worst case dose estimates based on very conservative assumptions indicate that a 25 rmem annual effective dose equivalent limit will not be exceeded under the most restrictive residential-use family farm scenario. Given the impermeable nature of the glacial till under CP-5, low-level concentrations of tritium may be occasionally detected in the deep well (3300 12D), but the peak concentration will not approach the levels calculated by RESRAD; however, continued monitoring of the deep well is recommended. To ensure that all sources of potential tritium release have been removed from the CP-5 complex, removal of tritiated water from each rod-out hole and an evaluation of the physical integrity of the …
Date: December 21, 1998
Creator: Hysong, R. J.
Object Type: Report
System: The UNT Digital Library
Independent Evaluation of Air Filter Media from Chornobyl (open access)

Independent Evaluation of Air Filter Media from Chornobyl

An independent evaluation was performed to assess the morphology, pressure drop characteristics, alpha spectroscopy characteristics, and collection efficiency of an air sampling filter media and two types of aerosol face masks provided from Chernobyl by Pacific Northwest National Laboratory. The evaluation included characterizing the filter morphology by scqg electron microscopy; measuring the filter pressure drop as a function of air flowrate; evaluating the spectroscopy characteristics of the filter for alpha-emitting radionuclides by sampling ambient radon progeny aerosols in an Eberline Alpha-6A alpha continuous air monitor; determining the particle collection efficiency of the filter media for 0.3 {micro}m aerodynamic diameter monodisperse particles at 1 and 2 cfm; and comparing the apparent construction, durability, and performance similarities of the filter media to other media commonly used for monitoring airborne alpha-emitting radionuclides.
Date: December 21, 1999
Creator: Hoover, MD; Fencl, AF & Vargo, GJ
Object Type: Report
System: The UNT Digital Library
Waste treatability guidance program. User`s guide. Revision 0 (open access)

Waste treatability guidance program. User`s guide. Revision 0

DOE sites across the country generate and manage radioactive, hazardous, mixed, and sanitary wastes. It is necessary for each site to find the technologies and associated capacities required to manage its waste. One role of DOE HQ Office of Environmental Restoration and Waste Management is to facilitate the integration of the site- specific plans into coherent national plans. DOE has developed a standard methodology for defining and categorizing waste streams into treatability groups based on characteristic parameters that influence waste management technology needs. This Waste Treatability Guidance Program automates the Guidance Document for the categorization of waste information into treatability groups; this application provides a consistent implementation of the methodology across the National TRU Program. This User`s Guide provides instructions on how to use the program, including installations instructions and program operation. This document satisfies the requirements of the Software Quality Assurance Plan.
Date: December 21, 1995
Creator: Toth, C.
Object Type: Report
System: The UNT Digital Library
Precision measurements at a muon collider (open access)

Precision measurements at a muon collider

We discuss the potential for making precision measurements of M{sub W} and M{sub T} at a muon collider and the motivations for each measurement. A comparison is made with the precision measurements expected at other facilities. The measurement of the top quark decay width is also discussed.
Date: December 21, 1995
Creator: Dawson, S.
Object Type: Article
System: The UNT Digital Library
Defining Requirements for Improved Photovoltaic System Reliability (open access)

Defining Requirements for Improved Photovoltaic System Reliability

Reliable systems are an essential ingredient of any technology progressing toward commercial maturity and large-scale deployment. This paper defines reliability as meeting system fictional requirements, and then develops a framework to understand and quantify photovoltaic system reliability based on initial and ongoing costs and system value. The core elements necessary to achieve reliable PV systems are reviewed. These include appropriate system design, satisfactory component reliability, and proper installation and servicing. Reliability status, key issues, and present needs in system reliability are summarized for four application sectors.
Date: December 21, 1998
Creator: Maish, A. B.
Object Type: Article
System: The UNT Digital Library
Photovoltaic Module Performance and Durability Following Long-Term Field Exposure (open access)

Photovoltaic Module Performance and Durability Following Long-Term Field Exposure

None
Date: December 21, 1998
Creator: King, D. L.; Quintana, M. A.; Kratochvil, J. A.; Ellibee, D. E. & Hansen, B. R.
Object Type: Article
System: The UNT Digital Library
Design and Fabrication of the First Commercial-Scale Liquid Phase Methanol (LPMEOH) Reactor (open access)

Design and Fabrication of the First Commercial-Scale Liquid Phase Methanol (LPMEOH) Reactor

The Liquid Phase Methanol (LPMEOHT) process uses a slurry bubble column reactor to convert synthesis gas (syngas), primarily a mixture of carbon monoxide and hydrogen, to methanol. Because of its superior heat management the process can utilize directly the carbon monoxide (CO)-rich syngas characteristic of the gasification of coal, petroleum coke, residual oil, wastes, or other hydrocarbon feedstocks. The LPMEOHM Demonstration Project at Kingsport, Tennessee, is a $213.7 million cooperative agreement between the U.S. Department of Energy (DOE) and Air Products Liquid Phase Conversion Company, L.P., a partnership between Air Products and Chemicals, Inc. and Eastman Chemical Company, to produce methanol from coal-derived syngas. Construction of the LPMEOH~ Process Demonstration Plant at Eastman's chemicals-from-coal complex in Kingsport was completed in January 1997. Following commissioning and shakedown activities, the fwst production of methanol from the facility occurred on April 2, 1997. Nameplate capacity of 260 short tons per day (TPD) was achieved on April 6, 1997, and production rates have exceeded 300 TPD of methanol at times. This report describes the design, fabrication, and installation of the Kingsport LPMEOEFM reactor, which is the first commercial-scale LPMEOEPM reaetor ever built. The vessel is 7.5 feet in diameter and 70 feet tall with …
Date: December 21, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Testing and Development of a 30-kVA Hybrid Inverter: Lessons Learned and Reliability Implications (open access)

Testing and Development of a 30-kVA Hybrid Inverter: Lessons Learned and Reliability Implications

A 30-kVA Trace Technologies hybrid power processor was specified and tested at the Sandia inverter test facility. Trace Technologies involving the control system, in response to suggestions made modifications, primarily by Sandia and Arizona Public Service (APS) personnel. The modifications should make the inverter more universally applicable and less site-specific so that it can be applied in various sites with minimal field interaction required from the design engineer. The project emphasized the importance of battery management, generator selection, and site load management to the performance and reliability of hybrid power systems.
Date: December 21, 1998
Creator: Ginn, J.W.
Object Type: Article
System: The UNT Digital Library
Commercial-Scale Demonstration of the Liquid Phase Methanol (LPMEOH) Process (open access)

Commercial-Scale Demonstration of the Liquid Phase Methanol (LPMEOH) Process

he Liquid Phase Methanol (LPMEOW) Demonstration Project at Kingsport Tennessee, is a $213.7 million cooperative agreement between the U.S. Department of Energy (DOE) and Air Products Liquid Phase Conversion Company, L.P. (the Partnership) to produce methanol from coal-derived synthesis gas (syngas). Air Products and Chemicals, Inc. (Air Products) and Eastman Chemical Company (Eastman) formed the Partnership to execute the Demonstration Project. The LPMEOEP Process Demonstration Unit was built at a site located at the Eastman coal-to-chemicals complex in Kingsport. The LPMEOHW Demonstration Facility completed its first year of operation on 02 April 1998. The LPMEOW Demonstration Facility also completed the longest continuous operating run (65 days) on 21 April 1998. Catalyst activity, as defined by the ratio of the rate constant at any point in time to the rate constant for freshly reduced catalyst (as determined in the laboratory autoclave), was monitored throughout the reporting period. During a six-week test at a reactor temperature of 225oC and Balanced Gas flowrate of 700 KSCFH, the rate of decline in catalyst activity was steady at 0.29-0.36% per day. During a second one-month test at a reactor temperature of 220oC and a Balanced Gas flowrate of 550-600 KSCFH, the rate of decline in …
Date: December 21, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Optimization and scale-up of fermentation process for production of microbial polysaccharide. Final technical progress report (open access)

Optimization and scale-up of fermentation process for production of microbial polysaccharide. Final technical progress report

This grant was awarded to provide for the scale-up of the process of production of a (1 {r_arrow})-{beta}-D-glucan which is produced by Cellulomonas flavigena. One of the goals was to provide sufficient amounts of the polysaccharide polymer to conduct a field test of its usefulness in subterranean permeability modification procedures of enhanced oil recovery. During September and October, 1994, fermentations and recoveries were done by Abbott Laboratories, to develop a process to provide at least 400 lbs of the glucan polymer for field testing. Shake flask runs and four fermentation runs were completed. A summary of the fourth fermentation run, conducted in a 40,000 liter fermentor, follows.
Date: December 21, 1994
Creator: Buller, C.S.
Object Type: Report
System: The UNT Digital Library
Chemical Solution Processing of Strontium Bismuth Tantalate Films (open access)

Chemical Solution Processing of Strontium Bismuth Tantalate Films

We describe Chemical Solution Deposition (CSD) processes by which Strontium Bismuth Tantalate (SBT) thin films can be prepared at temperatures as low as 550 C. In this paper, we will present strategies used to optimize the properties of the films including solution chemistry, film composition, the nature of the substrate (or bottom electrode) used, and the thermal processing cycle. Under suitable conditions, {approximately} 1700 {angstrom} films can be prepared which have a large switchable polarization (2P{sub r} > 10{micro}C/cm{sup 2}), and an operating voltage, defined as the voltage at which 0.80 x 2P{sub r} max is switched, 2.0V. We also describe an all-alkoxide route to SBT films from which SBT can be crystallized at 550 C.
Date: December 21, 1998
Creator: Boyle, T.J. & Lakeman, C.D.E.
Object Type: Article
System: The UNT Digital Library
Solar Heat-Pipe Receiver Wick Modeling (open access)

Solar Heat-Pipe Receiver Wick Modeling

Stirling-cycle engines have been identified as a promising technology for the conversion of concentrated solar energy into usable electrical power. In previous experimented work, we have demonstrated that a heat pipe receiver can significantly improve system performance-over a directly-illuminated heater head. The design and operating conditions of a heat pipe receiver differ significantly from typical laboratory heat pipes. New wick structures have been developed to exploit the characteristics of the solar generation system. Typically, these wick structures allow vapor generation within the wick. Conventional heat pipe models do not handle this enhancement yet it can more than double the performance of the wick. In this study, I develop a steady-state model of a boiling-enhanced wick for a solar heat pipe receiver. The model is used for design-point calculations and is written in FORTRAN90. Some limited comparisons have been made with actual test data.
Date: December 21, 1998
Creator: Andraka, C. E.
Object Type: Article
System: The UNT Digital Library