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Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
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1

Design optimization and analysis of coated particle fuel using advanced fuel performance modeling techniques  

E-Print Network (OSTI)

Modifying material properties provides another approach to optimize coated particle fuel used in pebble bed reactors. In this study, the MIT fuel performance model (TIMCOAT) was applied after benchmarking against the ...

Soontrapa, Chaiyod

2005-01-01T23:59:59.000Z

2

ATR LEU Fuel and Burnable Absorber Neutronics Performance Optimization by Fuel Meat Thickness Variation  

SciTech Connect

The Advanced Test Reactor (ATR) is a high power density and high neutron flux research reactor operating in the United States. Powered with highly enriched uranium (HEU), the ATR has a maximum thermal power rating of 250 MWth. Because of the large test volumes located in high flux areas, the ATR is an ideal candidate for assessing the feasibility of converting an HEU driven reactor to a low-enriched core. The present work investigates the necessary modifications and evaluates the subsequent operating effects of this conversion. A detailed plate-by-plate MCNP ATR 1/8th core model was developed and validated for a fuel cycle burnup comparison analysis. Using the current HEU U 235 enrichment of 93.0 % as a baseline, an analysis can be performed to determine the low-enriched uranium (LEU) density and U-235 enrichment required in the fuel meat to yield an equivalent K-eff between the HEU core and the LEU core versus effective full power days (EFPD). The MCNP ATR 1/8th core model will be used to optimize the U-235 loading in the LEU core, such that the differences in K-eff and heat flux profile between the HEU and LEU core can be minimized. The depletion methodology MCWO was used to calculate K-eff versus EFPDs in this paper. The MCWO-calculated results for the LEU cases with foil (U-10Mo) types demonstrated adequate excess reactivity such that the K-eff versus EFPDs plot is similar to the reference ATR HEU case. Each HEU fuel element contains 19 fuel plates with a fuel meat thickness of 0.508 mm. In this work, the proposed LEU (U-10Mo) core conversion case with a nominal fuel meat thickness of 0.508 mm and the same U-235 enrichment (15.5 wt%) can be used to optimize the radial heat flux profile by varying the fuel plate thickness from 0.254 to 0.457 mm at the inner 4 fuel plates (1-4) and outer 4 fuel plates (16-19). In addition, a 0.7g of burnable absorber Boron-10 was added in the inner and outer plates to reduce the initial excess reactivity, and the inner/outer heat flux more effectively. The optimized LEU relative radial fission heat flux profile is bounded by the reference ATR HEU case. However, to demonstrate that the LEU core fuel cycle performance can meet the Updated Final Safety Analysis Report (UFSAR) safety requirements, additional studies will be necessary to evaluate and compare safety parameters such as void reactivity and Doppler coefficients, control components worth (outer shim control cylinders, safety rods and regulating rod), and shutdown margins between the HEU and LEU cores.

G. S. Chang

2007-09-01T23:59:59.000Z

3

Optimal fuel cell system design considering functional performance and production costs  

E-Print Network (OSTI)

In this work the optimization-based, integrated concurrent design method is applied to the modelling, analysis, and design of a transportation fuel cell system. A general optimal design model considering both functional performance and production costs is first introduced. Using the Ballard Mark V Transit Bus fuel cell system as an example, the study explores the intrinsic relations among various fuel cell system performance and cost aspects to provide insights for new cost-effective designs. A joint performance and cost optimization is carried out to demonstrate this new approach. This approach breaks the traditional barrier between design concerning functional performance. and manufacturing concerning production costs., allowing both functional performance and production costs to

D. Xue A; Z. Dong B

1998-01-01T23:59:59.000Z

4

Performance Evaluation and Optimization of Diesel Fuel Properties and Chemistry in an HCCI Engine  

DOE Green Energy (OSTI)

The nine CRC fuels for advanced combustion engines (FACE fuels) have been evaluated in a simple, premixed HCCI engine under varying conditions of fuel rate, air-fuel ratio, and intake temperature. Engine performance was found to vary mainly as a function of combustion phasing as affected by fuel cetane and engine control variables. The data was modeled using statistical techniques involving eigenvector representation of the fuel properties and engine control variables, to define engine response and allow optimization across the fuels for best fuel efficiency. In general, the independent manipulation of intake temperature and air-fuel ratio provided some opportunity for improving combustion efficiency of a specific fuel beyond the direct effect of targeting the optimum combustion phasing of the engine (near 5 CAD ATDC). High cetane fuels suffer performance loss due to easier ignition, resulting in lower intake temperatures, which increase HC and CO emissions and result in the need for more advanced combustion phasing. The FACE fuels also varied in T90 temperature and % aromatics, independent of cetane number. T90 temperature was found to have an effect on engine performance when combined with high centane, but % aromatics did not, when evaluated independently of cetane and T90.

Bunting, Bruce G [ORNL; Eaton, Scott J [ORNL; Crawford, Robert W [Rincon Ranch Consulting

2009-01-01T23:59:59.000Z

5

The Fuel Control System and Performance Optimization of a Spark-Ignition LPG Engine  

Science Conference Proceedings (OSTI)

This paper presents an approach to control air fuel ratio of a Liquefied Petroleum Gas (LPG) automotive engine. The optimization of compression ratio is also described in this paper. HC, CO & NOx emissions of LPG engines can be reduced after the application ... Keywords: control, LPG engine, air fuel ratio, optimization

Hongwei Cui

2009-04-01T23:59:59.000Z

6

Compact fuel cell system utilizing a combination of hydrogen storage materials for optimized performance.  

SciTech Connect

An entirely new class of light-weight reversible hydrides was recently discovered (the Ti-doped alanates)[1]. These NaAIH{sub 4}-based materials have demonstrated reversible hydrogen storage capacities of up to 5 wt%, nearly 4 times the gravimetrically density of commercial metal hydrides. For this reason, they have been considered a breakthrough for hydrogen storage in fuel cell vehicles. This project is the first to publish the use of alanates for the generation of electrical power and the first demonstration of a hydride-fueled elevated-temperature PEM Fuel Cell. Because the kinetics of hydrogen uptake and release by the alanate improves with elevated temperatures, novel concepts were tested for the purpose of developing a highly efficient stand-alone power system. A major focus of this work was on the modeling, design, construction and testing of an integrated fuel cell stack and hydrogen storage system that eliminates the need of complicated heat transfer systems and media. After extensive modeling efforts, a proof-of-concept system was built that employs an integrated fuel cell stack and hydride beds that balancing the generation of fuel cell waste heat with the endothermic release of hydrogen from the alanates. Our demonstration unit was capable of greater than one hour of operation on a single charge of hydrogen from the integrated 173 gram alanate bed. In addition, composite hydride materials with synergistic reaction heats were evaluated and tested to enhance the operational performance of the alanates. The composites provide a unique opportunity to utilize the heat produced from hydriding classic metal hydrides to improve both absorption and desorption rates of the alanates. A particular focus of the mixed storage materials work was to balance the thermodynamics and kinetics of the hydrides for start-up conditions. Modeling of the sorption properties proved invaluable in evaluating the optimum composition of hydrides. The modeling efforts were followed by full validation by experimental measurements. This project successfully completed the proof-of-concept goals and generated a powerful set of tools for optimizing the complete power-generation system. It has also created a new direction for hydrogen power generation as well the potential for new R&D based on this work.

Chan, Jennifer P.; Dedrick, Daniel E.; Gross, Karl J.; Ng, Greg L.

2004-12-01T23:59:59.000Z

7

Performance and Optimization  

NLE Websites -- All DOE Office Websites (Extended Search)

1-800-66-NERSC, option 3 or 510-486-8611 Home For Users Computational Systems Edison Performance and Optimization Performance and Optimization Note: all the performance...

8

Performance and Optimization  

NLE Websites -- All DOE Office Websites (Extended Search)

and Optimization Performance and Optimization Compiler Comparisons Using a set of benchmarks described below, different optimization options for the different compilers on...

9

Z .Journal of Power Sources 76 1998 6980 Optimal fuel cell system design considering functional performance and  

E-Print Network (OSTI)

a semi-permeable Zmembrane, generating DC electricity, some heat at about .808C , and water of Victoria to develop the next generation fuel Z .cells for transportation NGFT , in collaborationZ .Journal of Power Sources 76 1998 69­80 Optimal fuel cell system design considering functional

Xue, Deyi

10

Influence of electrode stress on proton exchange membrane fuel cell performance : experimental characterization and power optimization  

E-Print Network (OSTI)

Compressive stress applied to the electrode area of a Proton Exchange Membrane (PEM) fuel cell is known to significantly affect power output. In practice, electrode stress arises during operation due to the clamping force ...

Gallant, Betar M. (Betar Maurkah)

2008-01-01T23:59:59.000Z

11

Performance optimization of gas turbine engine  

Science Conference Proceedings (OSTI)

Performance optimization of a gas turbine engine can be expressed in terms of minimizing fuel consumption while maintaining nominal thrust output, maximizing thrust for the same fuel consumption and minimizing turbine blade temperature. Additional control ... Keywords: Fuel control, Gas turbines, Genetic algorithms, Optimization, Temperature control

Valceres V. R. Silva; Wael Khatib; Peter J. Fleming

2005-08-01T23:59:59.000Z

12

Hopper Performance and Optimization  

NLE Websites -- All DOE Office Websites (Extended Search)

Optimization Optimization Performance and Optimization Compiler Comparisons Comparison of different compilers with different options on several benchmarks. Read More » Using OpenMP Effectively Performance implications and case studies of codes combining MPI and OpenMP Read More » Reordering MPI Ranks Reordering MPI ranks can result in improved application performance depending on the communication patterns of the application. Read More » Application Performance Variability on Hopper How an application is placed across Hopper's roughly 6300 compute nodes can affect its performance. See a study of application runtimes vs node placement. Read More » Hopper Performance Monitoring Benchmarking performance of scientific applications on Hopper Read More » Hopper:Improving I/O performance to GSCRATCH and PROJECT

13

Nitride fuel performance  

E-Print Network (OSTI)

The purpose of this work was to assess the potential of nitride fuels in the current context of the nuclear industry. Nitride fuels systems have indeed been for the past decade the subject of new interest from the international community. This renewal of interest can be explained by the strong potential that nitride fuel systems exhibit for applications such as advanced fast reactor technology, waste transmutation and nuclear space power. To assess this potential, a review of the nitride physical properties was performed in comparison to oxide or metal fuel properties. The potential applications of nitride systems were also detailed. A fuel performance computer code was developed to obtain a more quantitative comparison between nitride and oxide fuel. The oxide code FUELROD was taken as a basis for the new code. After modernization, nitride fuel property correlations were implemented to obtain a nitride version of the code. Using this new tool, a comparison between oxide and nitride fuels was performed to highlight their difference in irradiation behavior in order to confirm their potential.

Reynaud, Sylvie Marie Aurel?ie

2002-01-01T23:59:59.000Z

14

Optimally Controlled Flexible Fuel Powertrain System  

SciTech Connect

A multi phase program was undertaken with the stated goal of using advanced design and development tools to create a unique combination of existing technologies to create a powertrain system specification that allowed minimal increase of volumetric fuel consumption when operating on E85 relative to gasoline. Although on an energy basis gasoline / ethanol blends typically return similar fuel economy to straight gasoline, because of its lower energy density (gasoline ~ 31.8MJ/l and ethanol ~ 21.1MJ/l) the volume based fuel economy of gasoline / ethanol blends are typically considerably worse. This project was able to define an initial engine specification envelope, develop specific hardware for the application, and test that hardware in both single and multi-cylinder test engines to verify the ability of the specified powertrain to deliver reduced E85 fuel consumption. Finally, the results from the engine testing were used in a vehicle drive cycle analysis tool to define a final vehicle level fuel economy result. During the course of the project, it was identified that the technologies utilized to improve fuel economy on E85 also enabled improved fuel economy when operating on gasoline. However, the E85 fueled powertrain provided improved vehicle performance when compared to the gasoline fueled powertrain due to the improved high load performance of the E85 fuel. Relative to the baseline comparator engine and considering current market fuels, the volumetric fuel consumption penalty when running on E85 with the fully optimized project powertrain specification was reduced significantly. This result shows that alternative fuels can be utilized in high percentages while maintaining or improving vehicle performance and with minimal or positive impact on total cost of ownership to the end consumer. The justification for this project was two-fold. In order to reduce the US dependence on crude oil, much of which is imported, the US Environmental Protection Agency (EPA) developed the Renewable Fuels Standard (RFS) under the Energy Policy Act of 2005. The RFS specifies targets for the amount of renewable fuel to be blended into petroleum based transportation fuels. The goal is to blend 36 billion gallons of renewable fuels into transportation fuels by 2022 (9 billion gallons were blended in 2008). The RFS also requires that the renewable fuels emit fewer greenhouse gasses than the petroleum fuels replaced. Thus the goal of the EPA is to have a more fuel efficient national fleet, less dependent on petroleum based fuels. The limit to the implementation of certain technologies employed was the requirement to run the developed powertrain on gasoline with minimal performance degradation. The addition of ethanol to gasoline fuels improves the fuels octane rating and increases the fuels evaporative cooling. Both of these fuel property enhancements make gasoline / ethanol blends more suitable than straight gasoline for use in downsized engines or engines with increased compression ratio. The use of engine downsizing and high compression ratios as well as direct injection (DI), dual independent cam phasing, external EGR, and downspeeding were fundamental to the fuel economy improvements targeted in this project. The developed powertrain specification utilized the MAHLE DI3 gasoline downsizing research engine. It was a turbocharged, intercooled, DI engine with dual independent cam phasing utilizing a compression ratio of 11.25 : 1 and a 15% reduction in final drive ratio. When compared to a gasoline fuelled 2.2L Ecotec engine in a Chevrolet HHR, vehicle drive cycle predictions indicate that the optimized powertrain operating on E85 would result in a reduced volume based drive cycle fuel economy penalty of 6% compared to an approximately 30% penalty for current technology engines.

Duncan Sheppard; Bruce Woodrow; Paul Kilmurray; Simon Thwaite

2011-06-30T23:59:59.000Z

15

Measurement Protocols for Optimized Fuel Assembly Tags  

Science Conference Proceedings (OSTI)

This report describes the measurement protocols for optimized tags that can be applied to standard fuel assemblies used in light water reactors. This report describes work performed by the authors at Pacific Northwest National Laboratory for NA-22 as part of research to identify specific signatures that can be developed to support counter-proliferation technologies.

Gerlach, David C.; Mitchell, Mark R.; Reid, Bruce D.; Gesh, Christopher J.; Hurley, David E.

2008-11-01T23:59:59.000Z

16

Performance and Optimization  

NLE Websites -- All DOE Office Websites (Extended Search)

Performance and Performance and Optimization Performance and Optimization Benchmarking Software on Hopper and Carver PURPOSE Test the performance impact of multithreading with representative public domain software including blastn, blastp, rpsblast, hmmsearch, usearch. Run on Hopper (24 cores/node) and Carver (8 cores/node) with different combinations of the number of tasks and threads. Provide useful set of parameters to maximize throughput PROGRAMS TESTED BLAST+ programs (blastn, blastp, rpsblast) version 2.2.26 usearch verison 5.2.32 hmmsearch version 3.0 DATASETS usearch: a collection of protein sequences (~900MB) against a reference "udb" (~900MB) blastn Query: a collection of nucleotide sequences from NCBI Microbial database from ftp://ftp.ncbi.nlm.nih.gov/refseq/release/microbial/ (34,154

17

Optimally Controlled Flexible Fuel Powertrain System  

DOE Green Energy (OSTI)

The primary objective of this project was to develop a true Flex Fuel Vehicle capable of running on any blend of ethanol from 0 to 85% with reduced penalty in usable vehicle range. A research and development program, targeting 10% improvement in fuel economy using a direct injection (DI) turbocharged spark ignition engine was conducted. In this project a gasoline-optimized high-technology engine was considered and the hardware and configuration modifications were defined for the engine, fueling system, and air path. Combined with a novel engine control strategy, control software, and calibration this resulted in a highly efficient and clean FFV concept. It was also intended to develop robust detection schemes of the ethanol content in the fuel integrated with adaptive control algorithms for optimized turbocharged direct injection engine combustion. The approach relies heavily on software-based adaptation and optimization striving for minimal modifications to the gasoline-optimized engine hardware system. Our ultimate objective was to develop a compact control methodology that takes advantage of any ethanol-based fuel mixture and not compromise the engine performance under gasoline operation.

Hakan Yilmaz; Mark Christie; Anna Stefanopoulou

2010-12-31T23:59:59.000Z

18

Handbook of fuel cell performance  

DOE Green Energy (OSTI)

The intent of this document is to provide a description of fuel cells, their performances and operating conditions, and the relationship between fuel processors and fuel cells. This information will enable fuel cell engineers to know which fuel processing schemes are most compatible with which fuel cells and to predict the performance of a fuel cell integrated with any fuel processor. The data and estimates presented are for the phosphoric acid and molten carbonate fuel cells because they are closer to commercialization than other types of fuel cells. Performance of the cells is shown as a function of operating temperature, pressure, fuel conversion (utilization), and oxidant utilization. The effect of oxidant composition (for example, air versus O/sub 2/) as well as fuel composition is examined because fuels provided by some of the more advanced fuel processing schemes such as coal conversion will contain varying amounts of H/sub 2/, CO, CO/sub 2/, CH/sub 4/, H/sub 2/O, and sulfur and nitrogen compounds. A brief description of fuel cells and their application to industrial, commercial, and residential power generation is given. The electrochemical aspects of fuel cells are reviewed. The phosphoric acid fuel cell is discussed, including how it is affected by operating conditions; and the molten carbonate fuel cell is discussed. The equations developed will help systems engineers to evaluate the application of the phosphoric acid and molten carbonate fuel cells to commercial, utility, and industrial power generation and waste heat utilization. A detailed discussion of fuel cell efficiency, and examples of fuel cell systems are given.

Benjamin, T.G.; Camara, E.H.; Marianowski, L.G.

1980-05-01T23:59:59.000Z

19

Performance and optimization  

NLE Websites -- All DOE Office Websites (Extended Search)

they exercise. This categorization is similar in spirit to that used in the BLAS API. Currently, the levels are: Stability Tests Performance Tests Level 0: Very low level...

20

Benzene rectifying column performance optimization  

Science Conference Proceedings (OSTI)

Benzene rectifying column control at the actual petroleum refinery is studied. Certain approaches to increase the performance of precise rectification of benzene and toluene are suggested. An algorithm of evaluating the optimal regulation parameters ...

D. A. Smirnova; V. I. Fedorov; N. V. Lisitsyn

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Building Distributed Energy Performance Optimization for China...  

NLE Websites -- All DOE Office Websites (Extended Search)

Distributed Energy Performance Optimization for China - a Regional Analysis of Building Energy Costs and CO2 Emissions Title Building Distributed Energy Performance Optimization...

22

Fuel Reliability Project: Boiling Water Fuel Performance at Kernkraftwerk Leibstadt  

Science Conference Proceedings (OSTI)

The Kernkraftwerk Leibstadt (KKL) boiling water reactor (BWR), a General Electric BWR/6, performed a lead use assembly (LUA) program with fuel from three fuel suppliers. This program presented a unique opportunity to evaluate fuel performance on advanced 10x10 designs of AREVA, Global Nuclear Fuel (GNF), and Westinghouse Electric Company (Westinghouse). Fuel assemblies from each supplier (vendor) were loaded into the KKL core in 1997 and 1998. A number of fuel inspections have been performed during annua...

2007-05-16T23:59:59.000Z

23

A GUIDE TO FUEL PERFORMANCE  

Science Conference Proceedings (OSTI)

Heating oil, as its name implies, is intended for end use heating consumption as its primary application. But its identity in reference name and actual chemical properties may vary based on a number of factors. By name, heating oil is sometimes referred to as gas oil, diesel, No. 2 distillate (middle distillate), or light heating oil. Kerosene, also used as a burner fuel, is a No. 1 distillate. Due to the higher heat content and competitive price in most markets, No. 2 heating oil is primarily used in modern, pressure-atomized burners. Using No. 1 oil for heating has the advantages of better cold-flow properties, lower emissions, and better storage properties. Because it is not nearly as abundant in supply, it is often markedly more expensive than No. 2 heating oil. Given the advanced, low-firing rate burners in use today, the objective is for the fuel to be compatible and achieve combustion performance at the highest achievable efficiency of the heating systems--with minimal service requirements. Among the Oil heat industry's top priorities are improving reliability and reducing service costs associated with fuel performance. Poor fuel quality, fuel degradation, and contamination can cause burner shut-downs resulting in ''no-heat'' calls. Many of these unscheduled service calls are preventable with routine inspection of the fuel and the tank. This manual focuses on No. 2 heating oil--its performance, properties, sampling and testing. Its purpose is to provide the marketer, service manager and technician with the proper guidelines for inspecting the product, maintaining good fuel quality, and the best practices for proper storage. Up-to-date information is also provided on commercially available fuel additives, their appropriate use and limitations.

LITZKE,W.

2004-08-01T23:59:59.000Z

24

Selected Isotopes for Optimized Fuel Assembly Tags  

SciTech Connect

In support of our ongoing signatures project we present information on 3 isotopes selected for possible application in optimized tags that could be applied to fuel assemblies to provide an objective measure of burnup. 1. Important factors for an optimized tag are compatibility with the reactor environment (corrosion resistance), low radioactive activation, at least 2 stable isotopes, moderate neutron absorption cross-section, which gives significant changes in isotope ratios over typical fuel assembly irradiation levels, and ease of measurement in the SIMS machine 2. From the candidate isotopes presented in the 3rd FY 08 Quarterly Report, the most promising appear to be Titanium, Hafnium, and Platinum. The other candidate isotopes (Iron, Tungsten, exhibited inadequate corrosion resistance and/or had neutron capture cross-sections either too high or too low for the burnup range of interest.

Gerlach, David C.; Mitchell, Mark R.; Reid, Bruce D.; Gesh, Christopher J.; Hurley, David E.

2008-10-01T23:59:59.000Z

25

Fuel Performance Annual Report for 1979  

Science Conference Proceedings (OSTI)

This annual report, the second in a series, provides a brief description of fuel performance in commercial nuclear power plants. Brief summaries are given of fuel surveillance programs, fuel performance problems, and fuel design changes. References to additional, more detailed, information and related NRC evaluation are provided.

Tokar, M.; Mailey, W. J.; Cunningham, M. E.

1981-01-01T23:59:59.000Z

26

Fuel Performance Annual Report for 1980  

SciTech Connect

This annual report, the third in a series, provides a brief description of fuel performance in conmercial nuclear power plants. Brief summaries of fuel surveillance programs and operating experience, fuel performance problems, and fuel design changes are provided. References to additional, more detailed, information and related NRC evaluation are included.

Bailey, W. J.; Rising, K. H.; Tokar, M.

1981-12-01T23:59:59.000Z

27

Minor Actinides Loading Optimization for Proliferation Resistant Fuel Design - BWR  

Science Conference Proceedings (OSTI)

One approach to address the United States Nuclear Power (NP) 2010 program for the advanced light water reactor (LWR) (Gen-III+) intermediate-term spent fuel disposal need is to reduce spent fuel storage volume while enhancing proliferation resistance. One proposed solution includes increasing burnup of the discharged spent fuel and mixing minor actinide (MA) transuranic nuclides (237Np and 241Am) in the high burnup fuel. Thus, we can reduce the spent fuel volume while increasing the proliferation resistance by increasing the isotopic ratio of 238Pu/Pu. For future advanced nuclear systems, MAs are viewed more as a resource to be recycled, and transmuted to less hazardous and possibly more useful forms, rather than simply disposed of as a waste stream in an expensive repository facility. MAs play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors to the reactivity control of the systems into which they are incorporated. A typical boiling water reactor (BWR) fuel unit lattice cell model with UO2 fuel pins will be used to investigate the effectiveness of adding MAs (237Np and/or 241Am) to enhance proliferation resistance and improve fuel cycle performance for the intermediate-term goal of future nuclear energy systems. However, adding MAs will increase plutonium production in the discharged spent fuel. In this work, the Monte-Carlo coupling with ORIGEN-2.2 (MCWO) method was used to optimize the MA loading in the UO2 fuel such that the discharged spent fuel demonstrates enhanced proliferation resistance, while minimizing plutonium production. The axial averaged MA transmutation characteristics at different burnup were compared and their impact on neutronics criticality and the ratio of 238Pu/Pu discussed.

G. S. Chang; Hongbin Zhang

2009-09-01T23:59:59.000Z

28

Optimization of fossil fuel sources: An exergy approach  

SciTech Connect

We performed linear programming for optimization of fossil fuel supply in 2000 in Turkey. For this, an exergy analysis is made because the second law of thermodynamics takes into account the quality of energy as well as quantity of energy. Our analyses showed that the interfuel substitution between different fossil fuels will lead to a best energy mix of the country. The total retail price of fossil fuels can be lowered to 11.349 billion US$ from 13.012 billion US$ by increasing the domestic production of oil, lignite, and hard coal and by decreasing imports. The remaining demand can be met by natural gas imports. In conclusion, our analysis showed that a reduction of 1.663 billion US$ in fossil fuel cost can be made possible by giving more emphasis on domestic production, particularly of oil, lignite and hard coal.

Camdali, U. [Development Bank of Turkey, Ankara (Turkey)

2007-02-15T23:59:59.000Z

29

Synthetic fuels handbook: properties, process and performance  

Science Conference Proceedings (OSTI)

The handbook is a comprehensive guide to the benefits and trade-offs of numerous alternative fuels, presenting expert analyses of the different properties, processes, and performance characteristics of each fuel. It discusses the concept systems and technology involved in the production of fuels on both industrial and individual scales. Chapters 5 and 7 are of special interest to the coal industry. Contents: Chapter 1. Fuel Sources - Conventional and Non-conventional; Chapter 2. Natural Gas; Chapter 3. Fuels From Petroleum and Heavy Oil; Chapter 4. Fuels From Tar Sand Bitumen; Chapter 5. Fuels From Coal; Chapter 6. Fuels From Oil Shale; Chapter 7. Fuels From Synthesis Gas; Chapter 8. Fuels From Biomass; Chapter 9. Fuels From Crops; Chapter 10. Fuels From Wood; Chapter 11. Fuels From Domestic and Industrial Waste; Chapter 12. Landfill Gas. 3 apps.

Speight, J. [University of Utah, UT (United States)

2008-07-01T23:59:59.000Z

30

Fuel performance: Annual report for 1987  

SciTech Connect

This annual report, the tenth in a series, provides a brief description of fuel performance during 1987 in commercial nuclear power plants and an indication of trends. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience, fuel problems, high-burnup fuel experience, and items of general significance are provided. References to more detailed information and related US Nuclear Regulator Commission evaluations are included. 384 refs., 13 figs., 33 tabs.

Bailey, W.J.; Wu, S.

1989-03-01T23:59:59.000Z

31

Fuel performance annual report for 1986  

Science Conference Proceedings (OSTI)

This annual report, the ninth in a series, provides a brief description of fuel performance during 1986 in commercial nuclear power plants and an indication of trends. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience, fuel problems, high-burnup fuel experience, and items of general significance are provided. References to more detailed information and related U.S. Nuclear Regulatory Commission evaluations are included. 550 refs., 12 figs., 31 tabs.

Bailey, W.J.; Wu, S.

1988-03-01T23:59:59.000Z

32

Fuel performance annual report for 1988  

SciTech Connect

This annual report, the eleventh in a series, provides a brief description of fuel performance during 1988 in commercial nuclear power plants and an indication of trends. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience, fuel problems, high-burnup fuel experience, and items of general significance are provided. References to more detailed information and related US Nuclear Regulatory Commission evaluations are included. 414 refs., 13 figs., 32 tabs.

Bailey, W.J. (Pacific Northwest Lab., Richland, WA (USA)); Wu, S. (Nuclear Regulatory Commission, Washington, DC (USA). Div. of Engineering and Systems Technology)

1990-03-01T23:59:59.000Z

33

Fuel performance annual report for 1989  

SciTech Connect

This annual report, the twelfth in a series, provides a brief description of fuel performance during 1989 in commercial nuclear power plants and an indication of trends. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience, fuel problems, high-burnup fuel experience, and items of general significance are provided. References to more detailed information and related US Nuclear Regulatory Commission evaluations are included.

Bailey, W.J.; Berting, F.M. (Pacific Northwest Lab., Richland, WA (United States)); Wu, S. (Nuclear Regulatory Commission, Washington, DC (United States). Div. of Systems Technology)

1992-06-01T23:59:59.000Z

34

Fuel performance annual report for 1985  

Science Conference Proceedings (OSTI)

This annual report, the eighth in a series, provides a brief description of fuel performance during 1985 in commercial nuclear power plants and an indication of trends. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience, fuel problems, high-burnup fuel experience, and items of general significance are provided. References to additional, more detailed information and related NRC evaluations are included.

Bailey, W.J.; Wu, S.

1987-02-01T23:59:59.000Z

35

Mixed-Oxide (MOX) Fuel Performance Benchmarks  

Science Conference Proceedings (OSTI)

Within the framework of the OECD/NEA Expert Group on Reactor-based Plutonium disposition (TFRPD), a fuel modeling code benchmarks for MOX fuel was initiated. This paper summarizes the calculation results provided by the contributors for the first two fuel performance benchmark problems. A limited sensitivity study of the effect of the rod power uncertainty on code predictions of fuel centerline temperature and fuel pin pressure also was performed and is included in the paper.

Ott, Larry J [ORNL; Tverberg, Terje [OECD Halden Reactor Project; Sartori, Enrico [ORNL

2009-01-01T23:59:59.000Z

36

GASIFICATION PLANT COST AND PERFORMANCE OPTIMIZATION  

DOE Green Energy (OSTI)

This project developed optimized designs and cost estimates for several coal and petroleum coke IGCC coproduction projects that produced hydrogen, industrial grade steam, and hydrocarbon liquid fuel precursors in addition to power. The as-built design and actual operating data from the DOE sponsored Wabash River Coal Gasification Repowering Project was the starting point for this study that was performed by Bechtel, Global Energy and Nexant under Department of Energy contract DE-AC26-99FT40342. First, the team developed a design for a grass-roots plant equivalent to the Wabash River Coal Gasification Repowering Project to provide a starting point and a detailed mid-year 2000 cost estimate based on the actual as-built plant design and subsequent modifications (Subtask 1.1). This non-optimized plant has a thermal efficiency to power of 38.3% (HHV) and a mid-year 2000 EPC cost of 1,681 $/kW.1 This design was enlarged and modified to become a Petroleum Coke IGCC Coproduction Plant (Subtask 1.2) that produces hydrogen, industrial grade steam, and fuel gas for an adjacent Gulf Coast petroleum refinery in addition to export power. A structured Value Improving Practices (VIP) approach was applied to reduce costs and improve performance. The base case (Subtask 1.3) Optimized Petroleum Coke IGCC Coproduction Plant increased the power output by 16% and reduced the plant cost by 23%. The study looked at several options for gasifier sparing to enhance availability. Subtask 1.9 produced a detailed report on this availability analyses study. The Subtask 1.3 Next Plant, which retains the preferred spare gasification train approach, only reduced the cost by about 21%, but it has the highest availability (94.6%) and produces power at 30 $/MW-hr (at a 12% ROI). Thus, such a coke-fueled IGCC coproduction plant could fill a near term niche market. In all cases, the emissions performance of these plants is superior to the Wabash River project. Subtasks 1.5A and B developed designs for single-train coal- and coke-fueled IGCC power plants. A side-by-side comparison of these plants, which contain the Subtask 1.3 VIP enhancements, shows their similarity both in design and cost (1,318 $/kW for the coal plant and 1,260 $/kW for the coke plant). Therefore, in the near term, a coke IGCC power plant could penetrate the market and provide a foundation for future coal-fueled facilities. Subtask 1.6 generated a design, cost estimate and economics for a four-train coal-fueled IGCC power plant, also based on the Subtask 1.3 cases. This plant has a thermal efficiency to power of 40.6% (HHV) and cost 1,066 $/kW. The single-train advanced Subtask 1.4 plant, which uses an advanced ''G/H-class'' combustion turbine, can have a thermal efficiency to power of 44.5% (HHV) and a plant cost of 1,116 $/kW. Multi-train plants will further reduce the cost. Again, all these plants have superior emissions performance. Subtask 1.7 developed an optimized design for a coal to hydrogen plant. At current natural gas prices, this facility is not competitive with hydrogen produced from natural gas. The preferred scenario is to co-produce hydrogen in a plant similar to Subtask 1.3, as described above. Subtask 1.8 evaluated the potential merits of warm gas cleanup technology. This study showed that selective catalytic oxidation of hydrogen sulfide (SCOHS) is promising. Subtask 2.1 developed a petroleum coke IGCC power plant with the coproduction of liquid fuel precursors from the Subtask 1.3 Next Plant by eliminating the export steam and hydrogen production and replacing it with a Fischer-Tropsch hydrocarbon synthesis facility that produced 4,125 bpd of liquid fuel precursors. By maximizing liquids production at the expense of power generation, Subtask 2.2 developed an optimized design that produces 10,450 bpd of liquid fuel precursors and 617 MW of export power from 5,417 tpd of dry petroleum coke. With 27 $/MW-hr power and 30 $/bbl liquids, the Subtask 2.2 plant can have a return on investment of 18%. Subtask 2.3 converted the Subtask 1.6 four-train coal fueled IGCC power plant

Sheldon Kramer

2003-09-01T23:59:59.000Z

37

GASIFICATION PLANT COST AND PERFORMANCE OPTIMIZATION  

Science Conference Proceedings (OSTI)

This project developed optimized designs and cost estimates for several coal and petroleum coke IGCC coproduction projects that produced hydrogen, industrial grade steam, and hydrocarbon liquid fuel precursors in addition to power. The as-built design and actual operating data from the DOE sponsored Wabash River Coal Gasification Repowering Project was the starting point for this study that was performed by Bechtel, Global Energy and Nexant under Department of Energy contract DE-AC26-99FT40342. First, the team developed a design for a grass-roots plant equivalent to the Wabash River Coal Gasification Repowering Project to provide a starting point and a detailed mid-year 2000 cost estimate based on the actual as-built plant design and subsequent modifications (Subtask 1.1). This non-optimized plant has a thermal efficiency to power of 38.3% (HHV) and a mid-year 2000 EPC cost of 1,681 $/kW.1 This design was enlarged and modified to become a Petroleum Coke IGCC Coproduction Plant (Subtask 1.2) that produces hydrogen, industrial grade steam, and fuel gas for an adjacent Gulf Coast petroleum refinery in addition to export power. A structured Value Improving Practices (VIP) approach was applied to reduce costs and improve performance. The base case (Subtask 1.3) Optimized Petroleum Coke IGCC Coproduction Plant increased the power output by 16% and reduced the plant cost by 23%. The study looked at several options for gasifier sparing to enhance availability. Subtask 1.9 produced a detailed report on this availability analyses study. The Subtask 1.3 Next Plant, which retains the preferred spare gasification train approach, only reduced the cost by about 21%, but it has the highest availability (94.6%) and produces power at 30 $/MW-hr (at a 12% ROI). Thus, such a coke-fueled IGCC coproduction plant could fill a near term niche market. In all cases, the emissions performance of these plants is superior to the Wabash River project. Subtasks 1.5A and B developed designs for single-train coal- and coke-fueled IGCC power plants. A side-by-side comparison of these plants, which contain the Subtask 1.3 VIP enhancements, shows their similarity both in design and cost (1,318 $/kW for the coal plant and 1,260 $/kW for the coke plant). Therefore, in the near term, a coke IGCC power plant could penetrate the market and provide a foundation for future coal-fueled facilities. Subtask 1.6 generated a design, cost estimate and economics for a four-train coal-fueled IGCC power plant, also based on the Subtask 1.3 cases. This plant has a thermal efficiency to power of 40.6% (HHV) and cost 1,066 $/kW. The single-train advanced Subtask 1.4 plant, which uses an advanced ''G/H-class'' combustion turbine, can have a thermal efficiency to power of 44.5% (HHV) and a plant cost of 1,116 $/kW. Multi-train plants will further reduce the cost. Again, all these plants have superior emissions performance. Subtask 1.7 developed an optimized design for a coal to hydrogen plant. At current natural gas prices, this facility is not competitive with hydrogen produced from natural gas. The preferred scenario is to co-produce hydrogen in a plant similar to Subtask 1.3, as described above. Subtask 1.8 evaluated the potential merits of warm gas cleanup technology. This study showed that selective catalytic oxidation of hydrogen sulfide (SCOHS) is promising. Subtask 2.1 developed a petroleum coke IGCC power plant with the coproduction of liquid fuel precursors from the Subtask 1.3 Next Plant by eliminating the export steam and hydrogen production and replacing it with a Fischer-Tropsch hydrocarbon synthesis facility that produced 4,125 bpd of liquid fuel precursors. By maximizing liquids production at the expense of power generation, Subtask 2.2 developed an optimized design that produces 10,450 bpd of liquid fuel precursors and 617 MW of export power from 5,417 tpd of dry petroleum coke. With 27 $/MW-hr power and 30 $/bbl liquids, the Subtask 2.2 plant can have a return on investment of 18%. Subtask 2.3 converted the Subtask 1.6 four-train coal fueled IGCC power plant

Sheldon Kramer

2003-09-01T23:59:59.000Z

38

GASIFICATION PLANT COST AND PERFORMANCE OPTIMIZATION  

Science Conference Proceedings (OSTI)

The goal of this series of design and estimating efforts was to start from the as-built design and actual operating data from the DOE sponsored Wabash River Coal Gasification Repowering Project and to develop optimized designs for several coal and petroleum coke IGCC power and coproduction projects. First, the team developed a design for a grass-roots plant equivalent to the Wabash River Coal Gasification Repowering Project to provide a starting point and a detailed mid-year 2000 cost estimate based on the actual as-built plant design and subsequent modifications (Subtask 1.1). This unoptimized plant has a thermal efficiency of 38.3% (HHV) and a mid-year 2000 EPC cost of 1,681 $/kW. This design was enlarged and modified to become a Petroleum Coke IGCC Coproduction Plant (Subtask 1.2) that produces hydrogen, industrial grade steam, and fuel gas for an adjacent Gulf Coast petroleum refinery in addition to export power. A structured Value Improving Practices (VIP) approach was applied to reduce costs and improve performance. The base case (Subtask 1.3) Optimized Petroleum Coke IGCC Coproduction Plant increased the power output by 16% and reduced the plant cost by 23%. The study looked at several options for gasifier sparing to enhance availability. Subtask 1.9 produced a detailed report on this availability analyses study. The Subtask 1.3 Next Plant, which retains the preferred spare gasification train approach, only reduced the cost by about 21%, but it has the highest availability (94.6%) and produces power at 30 $/MW-hr (at a 12% ROI). Thus, such a coke-fueled IGCC coproduction plant could fill a near term niche market. In all cases, the emissions performance of these plants is superior to the Wabash River project. Subtasks 1.5A and B developed designs for single-train coal and coke-fueled power plants. This side-by-side comparison of these plants, which contain the Subtask 1.3 VIP enhancements, showed their similarity both in design and cost (1,318 $/kW for the coal plant and 1,260 $/kW for the coke plant). Therefore, in the near term, a coke IGCC power plant could penetrate the market and provide a foundation for future coal-fueled facilities. Subtask 1.6 generated a design, cost estimate and economics for a multiple train coal-fueled IGCC powerplant, also based on the Subtaks 1.3 cases. The Subtask 1.6 four gasification train plant has a thermal efficiency of 40.6% (HHV) and cost 1,066 $/kW. The single-train advanced Subtask 1.4 plant, which uses an advanced ''G/H-class'' combustion turbine, can have a thermal efficiency of 45.4% (HHV) and a plant cost of 1,096 $/kW. Multi-train plants will further reduce the cost. Again, all these plants have superior emissions performance. Subtask 1.7 developed an optimized design for a coal to hydrogen plant. At current natural gas prices, this facility is not competitive with hydrogen produced from natural gas. The preferred scenario is to coproduce hydrogen in a plant similar to Subtask 1.3, as described above. Subtask 1.8 evaluated the potential merits of warm gas cleanup technology. This study showed that selective catalytic oxidation of hydrogen sulfide (SCOHS) is promising. As gasification technology matures, SCOHS and other improvements identified in this study will lead to further cost reductions and efficiency improvements.

Samuel S. Tam

2002-05-01T23:59:59.000Z

39

Sootblowing optimization for improved boiler performance  

SciTech Connect

A sootblowing control system that uses predictive models to bridge the gap between sootblower operation and boiler performance goals. The system uses predictive modeling and heuristics (rules) associated with different zones in a boiler to determine an optimal sequence of sootblower operations and achieve boiler performance targets. The system performs the sootblower optimization while observing any operational constraints placed on the sootblowers.

James, John Robert; McDermott, John; Piche, Stephen; Pickard, Fred; Parikh, Neel J

2013-07-30T23:59:59.000Z

40

Sootblowing optimization for improved boiler performance  

SciTech Connect

A sootblowing control system that uses predictive models to bridge the gap between sootblower operation and boiler performance goals. The system uses predictive modeling and heuristics (rules) associated with different zones in a boiler to determine an optimal sequence of sootblower operations and achieve boiler performance targets. The system performs the sootblower optimization while observing any operational constraints placed on the sootblowers.

James, John Robert; McDermott, John; Piche, Stephen; Pickard, Fred; Parikh, Neel J.

2012-12-25T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Optimizing Pulverizer and Riffler Performance  

Science Conference Proceedings (OSTI)

Pulverizer problems rank high on the list of leading outage causes for coal-fired power plants (EPRI TR-101692). This document is an interim report that provides guidelines, descriptions, explanations, maintenance suggestions, and examples of the pulverizer and riffler systems. (A broader and more comprehensive report covering all aspects of the fuel delivery system will be issued as a final report in due course.) This document also discusses why and how the various components of a pulverizer influence s...

2003-12-01T23:59:59.000Z

42

Optimally moderated nuclear fission reactor and fuel source therefor  

DOE Patents (OSTI)

An improved nuclear fission reactor of the continuous fueling type involves determining an asymptotic equilibrium state for the nuclear fission reactor and providing the reactor with a moderator-to-fuel ratio that is optimally moderated for the asymptotic equilibrium state of the nuclear fission reactor; the fuel-to-moderator ratio allowing the nuclear fission reactor to be substantially continuously operated in an optimally moderated state.

Ougouag, Abderrafi M. (Idaho Falls, ID); Terry, William K. (Shelley, ID); Gougar, Hans D. (Idaho Falls, ID)

2008-07-22T23:59:59.000Z

43

Performance optimization of rotary dehumidifiers  

SciTech Connect

A rotary dehumidifier consists of a rotating porous matrix made of a desiccant with mechanically supporting materials. The dehumidification performance of a rotary dehumidifier wheel depends on its rotational speed, the sorption properties of the desiccant, the heat and mass transfer characteristics of the matrix, and the size of the dehumidifier. The effect of the rotational speed on the dehumidification performance of a rotary dehumidifier has been investigated by Zheng, Worek, and Novosel (1993). this paper extends that previous work and investigates the effects of desiccant sorption properties, the heat and mass transfer characteristics, and the size of the rotary dehumidifier on the dehumidification performance. The results show that the using desiccant materials in a rotary dehumidifier with different adsorption characteristics results in a wide variation in dehumidification performance. However, the maximum performance of a rotary dehumidifier occurs for a desiccant material having an isotherm shape that can be characterized to have a separation factor of 0.07. Also, as the desiccant moisture uptake increases, the dehumidifier performance also increases. However, the performance improvement for a desiccant matrix having a maximum moisture uptake of larger than 0.25 by weight is not significant. The heat and mass transfer properties and the size of rotary dehumidifier are characterized by the number of transfer units NTU. Generally, the larger the NTU, the better dehumidification performance. However, similar to the maximum moisture uptake, when the NTU is larger than 12, the performance will not improve significantly. Also, the dehumidifier with the most favorable adsorption characteristic has a slower rotational speed, which results in lower power requirements to rotate the desiccant wheel and smaller carry-over losses.

Zheng, W.; Worek, W.M. [Univ. of Chicago, IL (United States). Dept. of Mechanical Engineering; Novosel, D. [Gas Research Inst., Chicago, IL (United States)

1995-02-01T23:59:59.000Z

44

Quantification of Ultrasonic Fuel Cleaning Performance  

Science Conference Proceedings (OSTI)

Ultrasonic Fuel Cleaning (UFC) is a process developed by EPRI to remove deposits on PWR fuel assemblies. The process was first used at Callaway in 2001 and up to December 2009 a total of 96 UFC campaigns have been performed at twenty eight PWR plants worldwide.ObjectiveThe project objectives are:Compile and interpret the results of recent PWR fuel cleaning campaigns supplied to EPRI by utilities using a standard template ...

2012-10-30T23:59:59.000Z

45

Fuel Performance Analysis Capability in FALCON  

Science Conference Proceedings (OSTI)

The Fuel Analysis and Licensing Code -- New (FALCON) is being developed as a state-of-the-art light water reactor (LWR) fuel performance analysis and modeling code validated to high burnup. Based on a robust finite-element numerical structure, it is capable of analyzing both steady-state and transient fuel behaviors with a seamless transition between the two modes. EPRI plans to release a fully benchmarked and validated beta version of FALCON in 2003.

2002-12-06T23:59:59.000Z

46

Fuel Cycle Options for Optimized Recycling of Nuclear Fuel  

E-Print Network (OSTI)

The reduction of transuranic inventories of spent nuclear fuel depends upon the deployment of advanced fuels that can be loaded with recycled transuranics (TRU), and the availability of facilities to separate and reprocess ...

Aquien, A.

47

Optimal Performance of Quantum Refrigerators  

E-Print Network (OSTI)

A reciprocating quantum refrigerator is studied with the purpose of determining the limitations of cooling to absolute zero. We find that if the energy spectrum of the working medium possesses an uncontrollable gap, then there is a minimum achievable temperature above zero. Such a gap, combined with a negligible amount of noise, prevents adiabatic following during the demagnetization stage which is the necessary condition for reaching $T_c \\to 0$. The refrigerator is based on an Otto cycle where the working medium is an interacting spin system with an energy gap. For this system the external control Hamiltonian does not commute with the internal interaction. As a result during the demagnetization and magnetization segments of the operating cycle the system cannot follow adiabatically the temporal change in the energy levels. We connect the nonadiabatic dynamics to quantum friction. An adiabatic measure is defined characterizing the rate of change of the Hamiltonian. Closed form solutions are found for a constant adiabatic measure for all the cycle segments. We have identified a family of quantized frictionless cycles with increasing cycle times. These cycles minimize the entropy production. Such frictionless cycles are able to cool to $T_c=0$. External noise on the controls eliminates these frictionless cycles. The influence of phase and amplitude noise on the demagnetization and magnetization segments is explicitly derived. An extensive numerical study of optimal cooling cycles was carried out which showed that at sufficiently low temperature the noise always dominates restricting the minimum temperature.

Tova Feldmann; Ronnie Kosloff

2009-06-04T23:59:59.000Z

48

Gasification Plant Cost and Performance Optimization  

DOE Green Energy (OSTI)

As part of an ongoing effort of the U.S. Department of Energy (DOE) to investigate the feasibility of gasification on a broader level, Nexant, Inc. was contracted to perform a comprehensive study to provide a set of gasification alternatives for consideration by the DOE. Nexant completed the first two tasks (Tasks 1 and 2) of the ''Gasification Plant Cost and Performance Optimization Study'' for the DOE's National Energy Technology Laboratory (NETL) in 2003. These tasks evaluated the use of the E-GAS{trademark} gasification technology (now owned by ConocoPhillips) for the production of power either alone or with polygeneration of industrial grade steam, fuel gas, hydrocarbon liquids, or hydrogen. NETL expanded this effort in Task 3 to evaluate Gas Technology Institute's (GTI) fluidized bed U-GAS{reg_sign} gasifier. The Task 3 study had three main objectives. The first was to examine the application of the gasifier at an industrial application in upstate New York using a Southeastern Ohio coal. The second was to investigate the GTI gasifier in a stand-alone lignite-fueled IGCC power plant application, sited in North Dakota. The final goal was to train NETL personnel in the methods of process design and systems analysis. These objectives were divided into five subtasks. Subtasks 3.2 through 3.4 covered the technical analyses for the different design cases. Subtask 3.1 covered management activities, and Subtask 3.5 covered reporting. Conceptual designs were developed for several coal gasification facilities based on the fluidized bed U-GAS{reg_sign} gasifier. Subtask 3.2 developed two base case designs for industrial combined heat and power facilities using Southeastern Ohio coal that will be located at an upstate New York location. One base case design used an air-blown gasifier, and the other used an oxygen-blown gasifier in order to evaluate their relative economics. Subtask 3.3 developed an advanced design for an air-blown gasification combined heat and power facility based on the Subtask 3.2 design. The air-blown case was chosen since it was less costly and had a better return on investment than the oxygen-blown gasifier case. Under appropriate conditions, this study showed a combined heat and power air-blown gasification facility could be an attractive option for upgrading or expanding the utilities area of industrial facilities. Subtask 3.4 developed a base case design for a large lignite-fueled IGCC power plant that uses the advanced GE 7FB combustion turbine to be located at a generic North Dakota site. This plant uses low-level waste heat to dry the lignite that otherwise would be rejected to the atmosphere. Although this base case plant design is economically attractive, further enhancements should be investigated. Furthermore, since this is an oxygen-blown facility, it has the potential for capture and sequestration of CO{sub 2}. The third objective for Task 3 was accomplished by having NETL personnel working closely with Nexant and Gas Technology Institute personnel during execution of this project. Technology development will be the key to the long-term commercialization of gasification technologies. This will be important to the integration of this environmentally superior solid fuel technology into the existing mix of power plants and industrial facilities. As a result of this study, several areas have been identified in which research and development will further advance gasification technology. Such areas include improved system availability, development of warm-gas clean up technologies, and improved subsystem designs.

Samuel Tam; Alan Nizamoff; Sheldon Kramer; Scott Olson; Francis Lau; Mike Roberts; David Stopek; Robert Zabransky; Jeffrey Hoffmann; Erik Shuster; Nelson Zhan

2005-05-01T23:59:59.000Z

49

Pwr fuel assembly optimization using adaptive simulated annealing coupled with translat  

E-Print Network (OSTI)

Optimization methods have been developed and refined throughout many scientific fields of study. This work utilizes one such developed technique of optimization called simulated annealing to produce optimal operation parameters for a 15x15 fuel assembly to be used in an operating nuclear power reactor. The two main cases of optimization are: one that finds the optimal 235U enrichment layout of the fuel pins in the assembly and another that finds both the optimal 235U enrichments where gadolinium burnable absorber pins are also inserted. Both of these optimizations can be performed by coupling Adaptive Simulated Annealing to TransLAT which successfully searches the optimization space for a fuel assembly layout that produces the minimized pin power peaking factor. Within given time constraints this package produces optimal layouts within a given set of assumptions and constraints. Each layout is forced to maintain the fuel assembly average 235U enrichment as a constraint. Reductions in peaking factors that are produced through this method are on the order of 2% to 3% when compared to the baseline results. As with any simulated annealing approach, families of optimal layouts are produced that can be used at the engineers discretion.

Rogers, Timothy James

2008-08-01T23:59:59.000Z

50

Optimization of the Spatial and Temporal Fuel Distribution for...  

NLE Websites -- All DOE Office Websites (Extended Search)

Optimization of the Spatial and Temporal Fuel Distribution for Stable Combustion in Lean Premixed Combustors Speaker(s): Jong Guen Lee Date: November 30, 2000 - 12:00pm Location:...

51

Optimization of the Spatial and Temporal Fuel Distribution for Stable  

NLE Websites -- All DOE Office Websites (Extended Search)

Optimization of the Spatial and Temporal Fuel Distribution for Stable Optimization of the Spatial and Temporal Fuel Distribution for Stable Combustion in Lean Premixed Combustors Speaker(s): Jong Guen Lee Date: November 30, 2000 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Robert Cheng The limited success that has been achieved to date in suppressing unstable combustion in lean premixed combustors has been based on the use one of three approaches: a pilot flame, active combustion control using either primary or secondary fuel flow modulation, or modification of the fuel time lag. What these approaches have in common is that they all involve changing the spatial and/or temporal fuel distribution in a manner, which suppresses a given instability. In this presentation, results are presented from an experimental study of the effect of the spatial and temporal fuel

52

Gasifiers optimized for fuel cell applications  

DOE Green Energy (OSTI)

Conventional coal gasification carbonate fuel cell systems are typically configured as shown in Figure 1, where the fuel gas is primarily hydrogen, carbon monoxide, and carbon dioxide, with waste heat recovery for process requirements and to produce additional power in a steam bottoming cycle. These systems make use of present day gasification processes to produce the low to medium Btu fuel gas which in turn is cleaned up and consumed by the fuel cell. These conventional gasification/fuel cell systems have been studied in recent years projecting system efficiencies of 45--53% (HHV). Conventional gasification systems currently available evolved as stand-alone systems producing low to medium Btu gas fuel gas. The requirements of the gasification process dictates high temperatures to carry out the steam/carbon reaction and to gasify the tars present in coal. The high gasification temperatures required are achieved by an oxidant which consumes a portion of the feed coal to provide the endothermic heat required for the gasification process. The thermal needs of this process result in fuel gas temperatures that are higher than necessary for most end use applications, as well as for gas cleanup purposes. This results in some efficiency and cost penalties. This effort is designed to study advanced means of power generation by integrating the gasification process with the unique operating characteristics of carbonate fuel cells to achieve a more efficient and cost effective coal based power generating system. This is to be done by altering the gasification process to produce fuel gas compositions which result in more efficient fuel cell operation and by integrating the gasification process with the fuel cell as shown in Figure 2. Low temperature catalytic gasification was chosen as the basis for this effort due to the inherent efficiency advantages and compatibility with fuel cell operating temperatures.

Steinfeld, G.; Fruchtman, J.; Hauserman, W.B.; Lee, A.; Meyers, S.J.

1992-01-01T23:59:59.000Z

53

Gasifiers optimized for fuel cell applications  

DOE Green Energy (OSTI)

Conventional coal gasification carbonate fuel cell systems are typically configured as shown in Figure 1, where the fuel gas is primarily hydrogen, carbon monoxide, and carbon dioxide, with waste heat recovery for process requirements and to produce additional power in a steam bottoming cycle. These systems make use of present day gasification processes to produce the low to medium Btu fuel gas which in turn is cleaned up and consumed by the fuel cell. These conventional gasification/fuel cell systems have been studied in recent years projecting system efficiencies of 45--53% (HHV). Conventional gasification systems currently available evolved as stand-alone systems producing low to medium Btu gas fuel gas. The requirements of the gasification process dictates high temperatures to carry out the steam/carbon reaction and to gasify the tars present in coal. The high gasification temperatures required are achieved by an oxidant which consumes a portion of the feed coal to provide the endothermic heat required for the gasification process. The thermal needs of this process result in fuel gas temperatures that are higher than necessary for most end use applications, as well as for gas cleanup purposes. This results in some efficiency and cost penalties. This effort is designed to study advanced means of power generation by integrating the gasification process with the unique operating characteristics of carbonate fuel cells to achieve a more efficient and cost effective coal based power generating system. This is to be done by altering the gasification process to produce fuel gas compositions which result in more efficient fuel cell operation and by integrating the gasification process with the fuel cell as shown in Figure 2. Low temperature catalytic gasification was chosen as the basis for this effort due to the inherent efficiency advantages and compatibility with fuel cell operating temperatures.

Steinfeld, G.; Fruchtman, J.; Hauserman, W.B.; Lee, A.; Meyers, S.J.

1992-12-01T23:59:59.000Z

54

Transport Studies Enabling Efficiency Optimization of Cost-Competitive Fuel Cell Stacks  

NLE Websites -- All DOE Office Websites (Extended Search)

AURORA Program Overview Topic 4A. Transport within the PEM Stack / Transport Studies Transport Studies Enabling Efficiency Optimization of Cost-Competitive Fuel Cell Stacks Award#: DE-EE0000472 US DOE Fuel Cell Projects Kickoff Meeting Washington, DC September 30, 2009 Program Objectives The objective of this program is to optimize the efficiency of a stack technology meeting DOE cost targets. As cost reduction is of central importance in commercialization, the objective of this program addresses all fuel cell applications. AURORA C. Performance Technical Barriers Premise: DOE cost targets can be met by jointly exceeding both the Pt loading (1.0 W/cm2) targets.

55

EFFECT OF FUEL IMPURITIES ON FUEL CELL PERFORMANCE AND DURABILITY  

DOE Green Energy (OSTI)

A fuel cell is an electrochemical energy conversion device that produces electricity during the combination of hydrogen and oxygen to produce water. Proton exchange membranes fuel cells are favored for portable applications as well as stationary ones due to their high power density, low operating temperature, and low corrosion of components. In real life operation, the use of pure fuel and oxidant gases results in an impractical system. A more realistic and cost efficient approach is the use of air as an oxidant gas and hydrogen from hydrogen carriers (i.e., ammonia, hydrocarbons, hydrides). However, trace impurities arising from different hydrogen sources and production increases the degradation of the fuel cell. These impurities include carbon monoxide, ammonia, sulfur, hydrocarbons, and halogen compounds. The International Organization for Standardization (ISO) has set maximum limits for trace impurities in the hydrogen stream; however fuel cell data is needed to validate the assumption that at those levels the impurities will cause no degradation. This report summarizes the effect of selected contaminants tested at SRNL at ISO levels. Runs at ISO proposed concentration levels show that model hydrocarbon compound such as tetrahydrofuran can cause serious degradation. However, the degradation is only temporary as when the impurity is removed from the hydrogen stream the performance completely recovers. Other molecules at the ISO concentration levels such as ammonia don't show effects on the fuel cell performance. On the other hand carbon monoxide and perchloroethylene shows major degradation and the system can only be recovered by following recovery procedures.

Colon-Mercado, H.

2010-09-28T23:59:59.000Z

56

Metal fuel manufacturing and irradiation performance  

SciTech Connect

The advances in metal fuel by the Integral Fast Reactor Program at Argonne National Laboratory are the subject of this paper. The Integral Fast Reactor (IFR) is an advanced liquid-metal-cooled reactor concept being developed at Argonne National Laboratory. The advances stressed in the paper include fuel irradiation performance, and improved passive safety. The goals and the safety philosophy of the Integral Fast Reactor Program are stressed.

Pedersen, D.R.; Walters, L.C.

1992-01-01T23:59:59.000Z

57

Metal fuel manufacturing and irradiation performance  

SciTech Connect

The advances in metal fuel by the Integral Fast Reactor Program at Argonne National Laboratory are the subject of this paper. The Integral Fast Reactor (IFR) is an advanced liquid-metal-cooled reactor concept being developed at Argonne National Laboratory. The advances stressed in the paper include fuel irradiation performance, and improved passive safety. The goals and the safety philosophy of the Integral Fast Reactor Program are stressed.

Pedersen, D.R.; Walters, L.C.

1992-06-01T23:59:59.000Z

58

Fuel cycle optimization of thorium and uranium fueled PWR systems  

E-Print Network (OSTI)

The burnup neutronics of uniform PWR lattices are examined with respect to reduction of uranium ore requirements with an emphasis on variation of the fuel-to-moderator ratio

Garel, Keith Courtnay

1977-01-01T23:59:59.000Z

59

Fuel cycle options for optimized recycling of nuclear fuel  

E-Print Network (OSTI)

The accumulation of transuranic inventories in spent nuclear fuel depends on both deployment of advanced reactors that can be loaded with recycled transuranics (TRU), and on availability of the facilities that separate and ...

Aquien, Alexandre

2006-01-01T23:59:59.000Z

60

Improving Outage Performance: Outage Optimization Process  

SciTech Connect

Planned outage performance is a key measure of how well an Nuclear Power Plant (NPP) is operated. Performance during planned outages strongly affects virtually all of a plant's performance metrics. In recognition of this fact, NPP operators worldwide have and continue to focus on improving their outage performance. The process of improving outage performance is commonly referred to as 'Outage Optimization' in the industry. This paper starts with a summary of the principles of Outage Optimization. It then provides an overview of a process in common use in the USA and elsewhere to manage the improvement of planned outages. The program described is comprehensive in that it involves managing improvement in both the Preparation and Execution phases of outage management. (author)

LaPlatney, Jere J. [AREVA NP (United States)

2006-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Optimizing the Performance of Lithium Titanate Spinal Paired...  

NLE Websites -- All DOE Office Websites (Extended Search)

Optimizing the Performance of Lithium Titanate Spinal Paired with Activated Carbon or Iron Phosphate Title Optimizing the Performance of Lithium Titanate Spinal Paired with...

62

Outbound SPIT filter with optimal performance guarantees  

Science Conference Proceedings (OSTI)

This paper presents a formal framework for identifying and filtering SPIT calls (SPam in Internet Telephony) in an outbound scenario with provable optimal performance. In so doing, our work is largely different from related previous work: our goal is ... Keywords: Internet telephony, SPAM, Security, Sequential probability ratio test

Tobias Jung, Sylvain Martin, Mohamed Nassar, Damien Ernst, Guy Leduc

2013-05-01T23:59:59.000Z

63

Fuel performance annual report for 1983. Volume 1  

Science Conference Proceedings (OSTI)

This annual report, the sixth in a series, provides a brief description of fuel performance during 1983 in commercial nuclear power plants. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience, fuel problems, high-burnup fuel experience, and items of general significance are provided. References to additional, more detailed information and related NRC evaluations are included.

Bailey, W.J.; Dunenfeld, M.S.

1985-03-01T23:59:59.000Z

64

Fuel performance annual report for 1981. [PWR; BWR  

SciTech Connect

This annual report, the fourth in a series, provides a brief description of fuel performance during 1981 in commercial nuclear power plants. Brief summaries of fuel operating experience, fuel problems, fuel design changes and fuel surveillance programs, and high-burnup fuel experience are provided. References to additional, more detailed information and related NRC evaluations are included.

Bailey, W.J.; Tokar, M.

1982-12-01T23:59:59.000Z

65

Fuel performance annual report for 1990. Volume 8  

SciTech Connect

This annual report, the thirteenth in a series, provides a brief description of fuel performance during 1990 in commercial nuclear power plants. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience and trends, fuel problems high-burnup fuel experience, and items of general significance are provided . References to additional, more detailed information, and related NRC evaluations are included where appropriate.

Preble, E.A.; Painter, C.L.; Alvis, J.A.; Berting, F.M.; Beyer, C.E.; Payne, G.A. [Pacific Northwest Lab., Richland, WA (United States); Wu, S.L. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Systems Technology

1993-11-01T23:59:59.000Z

66

High performance internal reforming unit for high temperature fuel cells  

DOE Patents (OSTI)

A fuel reformer having an enclosure with first and second opposing surfaces, a sidewall connecting the first and second opposing surfaces and an inlet port and an outlet port in the sidewall. A plate assembly supporting a catalyst and baffles are also disposed in the enclosure. A main baffle extends into the enclosure from a point of the sidewall between the inlet and outlet ports. The main baffle cooperates with the enclosure and the plate assembly to establish a path for the flow of fuel gas through the reformer from the inlet port to the outlet port. At least a first directing baffle extends in the enclosure from one of the sidewall and the main baffle and cooperates with the plate assembly and the enclosure to alter the gas flow path. Desired graded catalyst loading pattern has been defined for optimized thermal management for the internal reforming high temperature fuel cells so as to achieve high cell performance.

Ma, Zhiwen (Sandy Hook, CT); Venkataraman, Ramakrishnan (New Milford, CT); Novacco, Lawrence J. (Brookfield, CT)

2008-10-07T23:59:59.000Z

67

NETL: Advanced NOx Emissions Control: Control Technology - Optimized Fuel  

NLE Websites -- All DOE Office Websites (Extended Search)

Optimized Fuel Injector Design Optimized Fuel Injector Design This project includes fundamental research and engineering development of low NOx burners and reburning fuel injectors. The team of Reaction Engineering International (REI), the University of Utah, Brown University and DB Riley, Inc., will develop fundamental information on low NOx burners. The work has two phases. In the first phase, the University of Utah will examine two-phase mixing and near-field behavior of coal injectors using a 15-million Btu/hr bench-scale furnace, Brown University will examine char deactivation and effectiveness of reburning, and REI will develop a comprehensive burner model using the data produced by the University of Utah and Brown University. In the second phase, an optimized injector design will be tested at the 100-million Btu/hr Riley Coal Burner Test Facility. It is anticipated that this work will provide improved hardware designs and computer simulation models for reduced NOx emissions and minimized carbon loss.

68

Optimization of Driving Styles for Fuel Economy Improvement  

SciTech Connect

Modern vehicles have sophisticated electronic control units, particularly to control engine operation with respect to a balance between fuel economy, emissions, and power. These control units are designed for specific driving conditions and testing. However, each individual driving style is different and rarely meets those driving conditions. In the research reported here we investigate those driving style factors that have a major impact on fuel economy. An optimization framework is proposed with the aim of optimizing driving styles with respect to these driving factors. A set of polynomial metamodels are constructed to reflect the responses produced by changes of the driving factors. Then we compare the optimized driving styles to the original ones and evaluate the efficiency and effectiveness of the optimization formulation.

Malikopoulos, Andreas [ORNL; Aguilar, Juan P. [Georgia Institute of Technology

2012-01-01T23:59:59.000Z

69

Fuels Performance Group: Center for Transportation Technologies and Systems  

SciTech Connect

Describes R&D and analysis in advanced petroleum-based and non-petroleum-based transportation fuels done by NREL's Fuels Performance Group.

2008-08-01T23:59:59.000Z

70

Fuels Performance Group: Center for Transportation Technologies and Systems  

DOE Green Energy (OSTI)

Describes R&D and analysis in advanced petroleum-based and non-petroleum-based transportation fuels done by NREL's Fuels Performance Group.

Not Available

2008-08-01T23:59:59.000Z

71

Used Nuclear Fuel Loading and Structural Performance Under Normal...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Used Nuclear Fuel Loading and Structural Performance Under Normal Conditions of Transport - Modeling, Simulation and Experimental Integration RD&D Plan Used Nuclear Fuel Loading...

72

Westinghouse BWR Fuel Performance Program--Phase 2  

Science Conference Proceedings (OSTI)

The Electric Power Research Institute (EPRI) Fuel Reliability Program (FRP) joined the Westinghouse Electric Sweden AB (WES) Fuel Performance Program Phase 2 to investigate the performance of ultra-high-burnup fuel to assess the potential for extending Westinghouse fuel burnups in the BWR fleet. Fuel rods irradiated in the Kernkraftwerk Leibstadt (KKL) reactor in Switzerland for up to nine annual cycles were examined in the spent fuel pool as well as in two hot cells (Paul Scherer Institute in Switzerl...

2009-10-02T23:59:59.000Z

73

SEAMOPT: A Stirling engine performance optimization code  

SciTech Connect

A computer code for Stirling engine research and design is described. The code system, SEAMOPT, has been used to: optimize component and engine performance, modify an existing engine to meet new application requirements, and identify design methods that lead to performance improvement and simplified engine design. SEAMOPT consists of a full Stirling engine simulation linked to a rigorous optimization code through an interface module which defines performance objectives and constraints which might limit values of design variables. Calculated results are presented from two example problems using the GPU-3 Stirling engine as a base design. The first example shows how regenerator dimensions can be changed to achieve three different performance objectives. The second example shows changes in the entire thermodynamic section needed to increase power by a factor of 8 while maintaining efficiency. The code, which requires 65K words of memory, executed problem 1 in 45 seconds and problem 2 in 10 minutes on an IBM 3033. 13 refs., 10 figs., 10 tabs.

Heames, T.J.; Daley, J.G.; Minkoff, M.

1986-05-01T23:59:59.000Z

74

Performance Assessment of ZIRLO-Clad Fuel from North Anna  

Science Conference Proceedings (OSTI)

This report assesses the results from the poolside and hot cell examination of Westinghouse ZIRLO fuel from North Anna relative to Westinghouse experience base and fuel performance code predictions. Key properties measured include fuel rod growth, corrosion, hydrogen pickup, mechanical properties, fuel pellet performance, and fission gas release.

2004-10-13T23:59:59.000Z

75

Design of gasifiers to optimize fuel cell systems  

DOE Green Energy (OSTI)

The objective of this project is to configure coal gasification/carbonate fuel cell systems that can significantly improve the economics, performance, and efficiency of electric power generation systems. (VC)

Not Available

1992-02-01T23:59:59.000Z

76

BWR Fuel Performance at KKL: 10 x 10 Fuel Irradiated to 54 GWd/MTU  

Science Conference Proceedings (OSTI)

The Kernkraftwerk Leibstadt (KKL) boiling water reactor (BWR) currently has a lead use assembly (LUA) program underway with fuel from three different fuel suppliers. This program presents a unique opportunity to simultaneously measure fuel performance on the advanced 10x10 designs of Framatome-ANP (F-ANP), Global Nuclear Fuel (GNF), and Westinghouse (W). Fuel assemblies from each supplier initially went into KKL in 1997 and 1998. A number of fuel inspections have been performed at various burnup levels a...

2003-12-08T23:59:59.000Z

77

Fuel performance annual report for 1984. Volume 2  

Science Conference Proceedings (OSTI)

This annual report, the seventh in a series, provides a brief description of fuel performance during 1984 in commercial nuclear power plants. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience, fuel problems, high-burnup fuel experience, and items of general significance are provided. References to additional, more detailed information and related NRC evaluations are included. 279 refs., 11 figs., 29 tabs.

Bailey, W.J.; Dunenfeld, M.S.

1986-03-01T23:59:59.000Z

78

EFFECTS OF FUEL IMPURITIES ON PEM FUEL CELL PERFORMANCE.  

DOE Green Energy (OSTI)

Power generation with polymer electrolyte membrane fuel cells (PEMFC), particularly those designed for domestic and transportation applications, will likely operate on hydrogen reformed from hydrocarbons. The primary sources of H{sub 2} can be methane (from natural gas), gasoline or diesel fuel. Unfortunately, the reforming process generates impurities that may negatively affect FC performance. The effects of CO impurity have received most of the attention. However, there are other impurities that also may be detrimental to FC: operation. Here we present the effects of ammonia, hydrogen sulfide, methane and ethylene. Two structural domains of the membrane and electrode assembly (MEA) are usually affected by the presence of a harmful impurity. First, the impurity may decrease the ionic conductivity in the catalyst layer or in the bulk membrane. Second, the impurity may chemisorb onto the anode catalyst surface, suppressing the catalyst activity for H{sub 2} oxidation. Catalyst poisoning by CO is the best known example of this kind of effect. Fuel reforming processes [1] generally involve the reaction of a fuel source with air. The simultaneous presence of N{sub 2} and H{sub 2} may generate NH{sub 3} in concentrations of 30 to 90 ppm [1]. The effect of NH{sub 3} on performance depends on the impurity concentration and the time of anode exposure [2]. Higher concentrations result in more rapid performance decreases. If the cell is exposed to ammonia for about 1 hour and then returned to neat H{sub 2}, it will recover its original performance very slowly (about 12 hrs). This behavior is quite different from that of CO, which can be quickly purged from the anode with pure H{sub 2}, resulting in complete performance restoration within a few minutes. Longer exposure times (e.g. >15 hrs) to ammonia result in severe and irreversible losses in performance. It seems that replacement of H{sup +} ions by NH{sub 4}{sup +} ions, first within the anode catalyst layer and then in the membrane, is the primary reason for cell current losses. H{sub 2}S also adversely affects FC performance. Figure 1 depicts the current density changes in a FC exposed to both 1 and 3 ppm H{sub 2}S while operating at a constant voltage of 0.5 V. As expected, the greater the contamination level the faster the current density drops. Eventually in each case the cell becomes totally disabled. The effect H{sub 2}S appears to be cumulative, because even sub-ppm H{sub 2}S levels will decrease the FC performance if the exposure is long enough. We have recorded slow current droppings to about 20% of the initial value after exposure to concentrations of H{sub 2}S of 200 parts per billion (10{sup 9}) for 650 hours. Exposure to higher concentrations of H{sub 2}S may bring catastrophic consequences. We have exposed cell anodes to H{sub 2}S burps of the order of 8 ppm, and observed that the current at 0.5 V dropped from 1.1 to 0.3 A cm{sup -2} in just few minutes. Figure 2 shows the effect of H{sub 2}S on cell polarization. Curves b and c in this figure were recorded after 4 and 21 hours of exposure to 1 ppm H{sub 2}S, respectively, while keeping the cell at a constant voltage of 0.5 V. Regardless impurity concentration and running time, replacing the contaminated fuel stream with pure H{sub 2} does not allow any recovery as observed with CO poisoning. Cyclic voltammmetry (CV) indicates that H{sub 2}S chemisorbs very strongly onto Pt catalyst surface and high voltages are required for full cleansing of the H{sub 2}S-poisoned active sites. After full anode poisoning with H{sub 2}S (curve c), the electrode was subjected to CV (up to 1.4 V) and then the polarization curve d (with neat H{sub 2}) was recorded. The complete cell performance recovery is apparent from this curve. A more extended discussion on H{sub 2}S catalyst poisoning and cleaning will be presented. We also tested methane (0.5 % by vol.) and ethylene (50 ppm) as potential fuel impurities and we found no effects on performance.

Uribe, F. A. (Francisco A.); Zawodzinski, T. A. (Thomas A.), Jr.

2001-01-01T23:59:59.000Z

79

Enterprise level fuel inventory management simulation and optimization.  

Science Conference Proceedings (OSTI)

The objective is to find the optimal fuel inventory management strategy roadmap for each supplier along the fuel delivery supply chain. SoSAT (System of Systems Analysis Toolset) Enterprise is a suite of software tools: State Model tool; Stochastic simulation tool; Advanced data visualization tools; and Optimization tools. Initially designed to provide DoDand supporting organizations the capability to analyze a System-of-Systems (SoS) and its various platforms: (1) Supporting multiple US Army Program Executive Office Integration (PEO-I) trade studies; (2) Supporting US Army Program Executive Office of Ground Combat Systems (PEO GCS) for Fleet Management and Modernization Planning initiative; and (3) Participating in formal Verification, Validation & Accreditation effort with Army Organizations (AMSAA and ATEC).

Kao, Gio K.; Eddy, John P.

2010-06-01T23:59:59.000Z

80

Microstructure Optimization in Fuel Cell Electrodes using Materials Design  

DOE Green Energy (OSTI)

Abstract A multiscale model based on statistical continuum mechanics is proposed to predict the mechanical and electrical properties of heterogeneous porous media. This model is applied within the framework of microstructure sensitive design (MSD) to guide the design of the microstructure in porous lanthanum strontium manganite (LSM) fuel cell electrode. To satisfy the property requirement and compatibility, porosity and its distribution can be adjusted under the guidance of MSD to achieve optimized microstructure.

Li, Dongsheng; Saheli, Ghazal; Khaleel, Mohammad A.; Garmestani, Hamid

2006-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Fuel performance annual report for 1991. Volume 9  

Science Conference Proceedings (OSTI)

This report is the fourteenth in a series that provides a compilation of information regarding commercial nuclear fuel performance. The series of annual reports were developed as a result of interest expressed by the public, advising bodies, and the US Nuclear Regulatory Commission (NRC) for public availability of information pertaining to commercial nuclear fuel performance. During 1991, the nuclear industry`s focus regarding fuel continued to be on extending burnup while maintaining fuel rod reliability. Utilities realize that high-burnup fuel reduces the amount of generated spent fuel, reduces fuel costs, reduces operational and maintenance costs, and improves plant capacity factors by extending operating cycles. Brief summaries of fuel operating experience, fuel design changes, fuel surveillance programs, high-burnup experience, problem areas, and items of general significance are provided.

Painter, C.L.; Alvis, J.M.; Beyer, C.E. [Pacific Northwest Lab., Richland, WA (United States); Marion, A.L. [Oregon State Univ., Corvallis, OR (United States). Dept. of Nuclear Engineering; Payne, G.A. [Northwest Coll. and Univ. Association for Science, Richland, WA (United States); Kendrick, E.D. [Nuclear Regulatory Commission, Washington, DC (United States)

1994-08-01T23:59:59.000Z

82

Optimizing Hydronic System Performance in Residential Applications  

SciTech Connect

Even though new homes constructed with hydronic heat comprise only 3% of the market (US Census Bureau 2009), of the 115 million existing homes in the United States, almost 14 million of those homes (11%) are heated with steam or hot water systems according to 2009 US Census data. Therefore, improvements in hydronic system performance could result in significant energy savings in the US. When operating properly, the combination of a gas-fired condensing boiler with baseboard convectors and an indirect water heater is a viable option for high-efficiency residential space heating in cold climates. Based on previous research efforts, however, it is apparent that these types of systems are typically not designed and installed to achieve maximum efficiency. Furthermore, guidance on proper design and commissioning for heating contractors and energy consultants is hard to find and is not comprehensive. Through modeling and monitoring, CARB sought to determine the optimal combination(s) of components - pumps, high efficiency heat sources, plumbing configurations and controls - that result in the highest overall efficiency for a hydronic system when baseboard convectors are used as the heat emitter. The impact of variable-speed pumps on energy use and system performance was also investigated along with the effects of various control strategies and the introduction of thermal mass.

Arena, L.; Faakye, O.

2013-10-01T23:59:59.000Z

83

Investigation of Fuel Cell System Performance and Operation: A Fuel Cell as a Practical  

E-Print Network (OSTI)

The low-grade heat from the fuel cell is utilized at the domestic hot water storage tank with a double The low-grade fuel cell heat feeds a heat exchanger to supply domestic hot water requirementsInvestigation of Fuel Cell System Performance and Operation: A Fuel Cell as a Practical Distributed

84

Early User Experience with BISON Fuel Performance Code  

SciTech Connect

Three Fuel Modeling Exercise II (FUMEX II) LWR fuel irradiation experiments were simulated and analyzed using the fuel performance code BISON to demonstrate code utility for modeling of the LWR fuel performance. Comparisons were made against the BISON results and the experimental data for the three assessment cases. The assessment cases reported within this report include IFA-597.3 Rod 8, Riso AN3 and Riso AN4.

D. M. Perez

2012-08-01T23:59:59.000Z

85

Design and Performance Validation of a Fuel Cell Unmanned  

E-Print Network (OSTI)

This paper describes methods for design of an unmanned aerial vehicle which uses a proton exchange membrane fuel cell as its primary powerplant. The proposed design methods involve the development of empirical and physics-based contributing analyses to model the performance of the aircraft subsystems. The contributing analyses are collected into a design structure matrix which is used to map aircraft performance metrics as a function of design variables over a defined design space. An exhaustive search within the design space is performed to identify optimal design configurations and to characterize trends within the design space so as to inform lower-level design decisions. The results of the design process are used to construct a demonstration fuel cell-powered aircraft. Test results from the demonstration aircraft and its subsystems are compared to predicted results to validate the contributing analyses and improve their accuracy in further design iterations. Nomenclature A = Metal hydride tank area AR = Aspect ratio CL CMH = Lift coefficient (Referenced to the planform wing area) = Specific heat capacity of metal hydride, 419 J/kg o C dtank h = Diameter of metal hydride tank, m

Blake A. Moffitt; Thomas H. Bradley; David E. Parekh; Dimitri Mavris

2006-01-01T23:59:59.000Z

86

Performance and fuel cycle cost study of the R2 reactor with HEU and LEU fuels  

SciTech Connect

A systematic study of the experiment performance and fuel cycle costs of the 50 MW R2 reactor operated by Studsvik Energiteknik AB has been performed using the current R2 HEU fuel, a variety of LEU fuel element designs, and two core-box/reflector configurations. The results include the relative performance of both in-core and ex-core experiments, control rod worths, and relative annual fuel cycle costs.

Pond, R.B.; Freese, K.E.; Matos, J.E.

1984-01-01T23:59:59.000Z

87

Optimizing Anode Performance in DUBAL Reduction Cells  

Science Conference Proceedings (OSTI)

Reduction in Gross Carbon consumption by 5% over the past 4 years was achieved through optimization of anode quality, modification of anode design and...

88

Refinery analytical techniques optimize unit performance  

Science Conference Proceedings (OSTI)

Refinery process engineers need to consider benefits of laboratory analytical techniques when evaluating unit performance. Refinery heavy-oil laboratory analytical techniques use both old and new technologies. Knowing how to use available laboratory analytical techniques within their limitations are critical to obtain correct refinery optimization decisions. Better refinery stream distillation and contaminant data ultimately improves the accuracy of various refinery decision-making tools. These laboratory analytical techniques are covered: high-temperature simulated distillation (HTSD); true boiling point (TBP) distillation--ASTM D2892; vacuum distillation--ASTM D5236; continuous-flash vaporizers; wiped-film evaporators; inductively coupled plasma atomic-emission spectroscopy (ICP-AES); Conradson--ASTM D189/Microcarbon residue--ASTM D4530; and asphaltene IP-143, ASTM D3279, ASTM D4124. Analysis of atmospheric crude, vacuum crude and delayed coker units highlight these laboratory techniques to identify potential yield and product quality benefits. Physical distillation or wiped-film evaporation in conjunction with HTSD, ICP-AES, microcarbon residue and asphaltened data will better characterize a feedstock as well as determine the source of contaminants. Economics are refinery specific, therefore, these examples focus on applying laboratory techniques as opposed to discussing specifics of unit improvement. These are discussed qualitatively.

Golden, S.W. [Process Consulting Services Inc., Grapevine, TX (United States); Craft, S. [Chempro, Inc., LaPorte, TX (United States); Villalanti, D.C. [Triton Analytics Corp., Houston, TX (United States)

1995-11-01T23:59:59.000Z

89

Used Nuclear Fuel Loading and Structural Performance Under Normal  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Nuclear Fuel Loading and Structural Performance Under Normal Nuclear Fuel Loading and Structural Performance Under Normal Conditions of Transport - Demonstration of Approach and Results of Used Fuel Performance Characterization Used Nuclear Fuel Loading and Structural Performance Under Normal Conditions of Transport - Demonstration of Approach and Results of Used Fuel Performance Characterization This report provides results of the initial demonstration of the modeling capability developed to perform preliminary deterministic evaluations of moderate-to-high burnup used nuclear fuel (UNF) mechanical performance under normal conditions of storage (NCS) and normal conditions of transport (NCT) conditions. This report also provides results from the sensitivity studies, and discussion on the long-term goals and objectives of this

90

Computational Modeling and Optimization of Proton Exchange Membrane Fuel Cells  

E-Print Network (OSTI)

power density (HPD) solid oxide fuel cell (SOFC) is a geometry based on a tubular type SOFC increased power density, but still maintains the beneficial feature of secure sealing for a tubular SOFC. In this paper, the electric performance of a flat-tube HPD SOFC is studied. This paper also investigates

Victoria, University of

91

Optimal Control of the Solid Fuel Ignition Model with H1-Cost  

Science Conference Proceedings (OSTI)

Optimal control problems for the stationary as well as the time-dependent solid fuel ignition model are investigated. Existence of optimal controls is proved, and optimality systems are derived. The analysis is based on a closedness lemma for the exponential ... Keywords: control of exponential nonlinearity, explosion phenomena, optimal control, optimality conditions

Kazufumi Ito; Karl Kunisch

2001-05-01T23:59:59.000Z

92

High Performance Diesel Fueled Cabin Heater  

DOE Green Energy (OSTI)

Recent DOE-OHVT studies show that diesel emissions and fuel consumption can be greatly reduced at truck stops by switching from engine idle to auxiliary-fired heaters. Brookhaven National Laboratory (BNL) has studied high performance diesel burner designs that address the shortcomings of current low fire-rate burners. Initial test results suggest a real opportunity for the development of a truly advanced truck heating system. The BNL approach is to use a low pressure, air-atomized burner derived form burner designs used commonly in gas turbine combustors. This paper reviews the design and test results of the BNL diesel fueled cabin heater. The burner design is covered by U.S. Patent 6,102,687 and was issued to U.S. DOE on August 15, 2000.The development of several novel oil burner applications based on low-pressure air atomization is described. The atomizer used is a pre-filming, air blast nozzle of the type commonly used in gas turbine combustion. The air pressure used can b e as low as 1300 Pa and such pressure can be easily achieved with a fan. Advantages over conventional, pressure-atomized nozzles include ability to operate at low input rates without very small passages and much lower fuel pressure requirements. At very low firing rates the small passage sizes in pressure swirl nozzles lead to poor reliability and this factor has practically constrained these burners to firing rates over 14 kW. Air atomization can be used very effectively at low firing rates to overcome this concern. However, many air atomizer designs require pressures that can be achieved only with a compressor, greatly complicating the burner package and increasing cost. The work described in this paper has been aimed at the practical adaptation of low-pressure air atomization to low input oil burners. The objective of this work is the development of burners that can achieve the benefits of air atomization with air pressures practically achievable with a simple burner fan.

Butcher, Tom

2001-08-05T23:59:59.000Z

93

High Performance Fuel Desing for Next Generation Pressurized Water Reactors  

SciTech Connect

The use of internally and externally cooled annular fule rods for high power density Pressurized Water Reactors is assessed. The assessment included steady state and transient thermal conditions, neutronic and fuel management requirements, mechanical vibration issues, fuel performance issues, fuel fabrication methods and econmic assessment. The investigation was donducted by a team from MIT, Westinghouse, Gamma Engineering, Framatome ANP, and AECL. The analyses led to the conclusion that raising the power density by 50% may be possible with this advanced fuel. Even at the 150% power level, the fuel temperature would be a few hundred degrees lower than the current fuel temperatre. Significant economic and safety advantages can be obtained by using this fuel in new reactors. Switching to this type of fuel for existing reactors would yield safety advantages, but the economic return is dependent on the duration of plant shutdown to accommodate higher power production. The main feasiblity issue for the high power performance appears to be the potential for uneven splitting of heat flux between the inner and outer fuel surfaces due to premature closure of the outer fuel-cladding gap. This could be overcome by using a very narrow gap for the inner fuel surface and/or the spraying of a crushable zirconium oxide film at the fuel pellet outer surface. An alternative fuel manufacturing approach using vobropacking was also investigated but appears to yield lower than desirable fuel density.

Mujid S. Kazimi; Pavel Hejzlar

2006-01-31T23:59:59.000Z

94

Fuel Reliability Program: Falcon Fuel Performance Code Version 1.2  

Science Conference Proceedings (OSTI)

Falcon Fuel Rod Performance Code, Version 1.2, is a combined steady-state and transient thermal/mechanical finite element (FE) code for analyzing light water reactor fuel behavior. The modeling ...

2012-09-30T23:59:59.000Z

95

NREL UL Fuel Dispensing Infrastructure Intermediate Blends Performance Testing (Presentation)  

DOE Green Energy (OSTI)

Presentation provides an overview of NREL's project to determine compatibility and safe performance of installed fuel dispensing infrastructure with E15.

Moriarty, K.; Clark, W.

2011-01-01T23:59:59.000Z

96

Optimum Performance of Direct Hydrogen Hybrid Fuel Cell Vehicles  

E-Print Network (OSTI)

ultracapacitors, fuel cells and hybrid vehicle design. Dr.on electric and hybrid vehicle technology and applicationsand performance. Hybrid vehicles utilizing a load leveling

Zhao, Hengbing; Burke, Andy

2009-01-01T23:59:59.000Z

97

The Effect of Airborne Contaminants on Fuel Cell Performance...  

NLE Websites -- All DOE Office Websites (Extended Search)

Energy Institute www.hnei.hawaii.edu The Effect of Airborne Contaminants on Fuel Cell Performance & Durability Richard Rocheleau Trent Molter William Collins Silvia Wessel Hawaii...

98

Residential Fuel Cell Performance Test Facility  

Science Conference Proceedings (OSTI)

... Currently, the test facility is setup to deliver natural gas as the fuel, but ... A turbine and magnetic flow meter measure the flow of water for the domestic ...

2011-11-15T23:59:59.000Z

99

Detailed analysis of an endoreversible fuel cell : Maximum power and optimal operating temperature determination  

E-Print Network (OSTI)

Producing useful electrical work in consuming chemical energy, the fuel cell have to reject heat to its surrounding. However, as it occurs for any other type of engine, this thermal energy cannot be exchanged in an isothermal way in finite time through finite areas. As it was already done for various types of systems, we study the fuel cell within the finite time thermodynamics framework and define an endoreversible fuel cell. Considering different types of heat transfer laws, we obtain an optimal value of the operating temperature, corresponding to a maximum produced power. This analysis is a first step of a thermodynamical approach of design of thermal management devices, taking into account performances of the whole system.

A. Vaudrey; P. Baucour; F. Lanzetta; R. Glises

2009-05-18T23:59:59.000Z

100

Detailed analysis of an endoreversible fuel cell : Maximum power and optimal operating temperature determination  

E-Print Network (OSTI)

Producing useful electrical work in consuming chemical energy, the fuel cell have to reject heat to its surrounding. However, as it occurs for any other type of engine, this thermal energy cannot be exchanged in an isothermal way in finite time through finite areas. As it was already done for various types of systems, we study the fuel cell within the finite time thermodynamics framework and define an endoreversible fuel cell. Considering different types of heat transfer laws, we obtain an optimal value of the operating temperature, corresponding to a maximum produced power. This analysis is a first step of a thermodynamical approach of design of thermal management devices, taking into account performances of the whole system.

Vaudrey, A; Lanzetta, F; Glises, R

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Optimization of Boiling Water Reactor Fuel Crud Characteristics for Reducing Radiation Fields: Evaluation of BWR Fuel Crud Properties  

Science Conference Proceedings (OSTI)

Fuel crud formation and its properties are the combined result of many factors, including corrosion product input, zinc addition rates, reactor coolant chemistry, and fuel and core design. Crud deposition may impact fuel performance as well as radiation field generation. Many projects have evaluated changes in fuel crud properties resulting from changing reactor coolant chemistry. However, the desired crud properties for both good fuel performance and mitigation of radiation field source term are ...

2013-11-26T23:59:59.000Z

102

Benchmarking optimization software with performance profiles  

E-Print Network (OSTI)

Mar 15, 2001 ... Abstract: We propose performance profiles -- probability distribution functions for a performance metric -- as a tool for benchmarking and...

103

Alternative fuel performance and emissions characteristics  

DOE Green Energy (OSTI)

This report addresses the question of what problems might be caused by the use of non-petroleum based gasolines in a standard throttle body fuel injection closed-loop spark-ignition internal combustion engine. Five fuels were tested in five separate but physically identical engines. The five fuels were, one baseline unleaded gasoline, two oil shale-derived gasolines, and two coal-derived gasolines. The basic testing of a fuel centered around a 5 hour cycle which was repeated daily until 200 hours of operation were accumulated. The 5 hour cycle was run by alternating every 15 minutes between two distinct conditions. The engines were disassembled and inspected nine times. Additionally, thermal efficiency, regulated emissions, unburnt hydrocarbon makeup, catalyst pressure drop, and cylinder pressure versus crankshaft position measurements were made. Noteworthy differences in the behavior of the fuels in terms of producing deposits that caused intake valve sticking are presented in this report. Additionally, the fuels behaved differently when operated in the presence of knock producing deposits. (R + M)/2 octane numbers proved to be a poor indicator of the fuels knocking behavior. R-M octane numbers proved to be a better indicator of knocking behavior. 16 refs., 43 figs., 29 tabs.

Not Available

1987-01-01T23:59:59.000Z

104

Effects of Fuel and Air Impurities on PEM Fuel Cell Performance  

NLE Websites -- All DOE Office Websites (Extended Search)

Approach * Fabricate and operate fuel cells under controlled impurity gases - Multi-gas mixing manifolds and FC test stations - Pre-blend impurity gases - Measure performance...

105

Fuel Cell Rebate and Performance Incentive | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Fuel Cell Rebate and Performance Incentive Fuel Cell Rebate and Performance Incentive Fuel Cell Rebate and Performance Incentive < Back Eligibility Commercial Industrial Institutional Local Government Nonprofit Residential Schools State Government Savings Category Alternative Fuel Vehicles Hydrogen & Fuel Cells Maximum Rebate '''Total Incentives:''' Large systems (larger than 25 kW): $1 million Small systems (up to 25 kW): $50,000 '''Capacity Incentives:''' Large systems only (larger than 25 kW): $200,000 for basic capacity incentive, $100,000 for bonus capacity incentive '''Performance Incentives:''' Large systems (greater than 25 kW): $300,000 per year per project site Small systems (up to 25 kW): $20,000 per year per project site Program Info State New York Program Type Performance-Based Incentive

106

Alternative fuels performance and emissions characteristics  

DOE Green Energy (OSTI)

This report addresses the question of what problems might be caused by the use of non-petroleum based gasolines in a standard throttle body fuel injection closed-loop spark-ignition internal combustion engine. Five fuels were tested in five separate but physically identical engines. The five fuels were, one baseline unleaded gasoline, two oil shale-derived gasolines, and two coal-derived gasolines. The basic testing of a fuel centered around a 5 hour cycle which was repeated daily until 200 hours of operation were accumulated. The 5 hour cycle was run by alternating every 15 minutes between two distinct conditions. During the accumulation of the 200 hours of operation, the engines were disassembled and inspected nine times. Additionally, thermal efficiency, regulated emissions, unburnt hydrocarbon makeup, catalyst pressure drop, and cylinder pressure versus crankshaft position measurements were made. Negligibly small differences were recorded in the behavior of the fuels, in terms of brake thermal efficiency, regulated emissions, effect on oxygen sensor life, and effect on catalyst life. Noteworthy differences in individual unburnt hydrocarbon concentration in the exhaust were recorded. Noteworthy differences in the behavior of the fuels in terms of producing deposits that caused intake valve sticking are presented in this report. Additionally, the fuels behaved differently when operated in the presence of knock producing deposits. (R+M)/2 octane numbers proved to be a poor indicator of the fuels knocking behavior. R-M octane numbers proved to be a better indicator of knocking behavior. 16 refs., 43 figs., 29 tabs.

Swain, M.R.; Swain, M.N.; Blanco, J.A.; Adt, R.R. Jr.

1987-01-01T23:59:59.000Z

107

NETL: News Release - GE Sets Benchmarks for Fuel Cell Performance  

NLE Websites -- All DOE Office Websites (Extended Search)

August 8, 2005 August 8, 2005 GE Sets Benchmarks for Fuel Cell Performance Achievements Move Efficient, Clean SOFC Technology Closer to Mainstream Energy Markets TORRANCE, CA - In the race to speed solid oxide fuel cell (SOFC) technology out of niche markets and into widespread commercial use, GE Hybrid Power Generation Systems has kicked fuel cell performance into high gear. Recent advancements have dramatically improved baseline cell performance and accelerate GE's prospects for achieving the system efficiency and cost objectives of DOE's Solid State Energy Alliance (SECA) program. Packing more power into smaller volumes is one of the breakthroughs needed to reduce the cost and expand the use of efficient, environmentally friendly fuel cells. But increasing power density isn't the only goal; as power density increases, fuel cells must continue to efficiently and reliably convert fuel to electric power.

108

Fuel Design Evaluation Handbook: Tools for Assessing Fuel and Core Component Performance  

Science Conference Proceedings (OSTI)

The overall objective of this report is to provide a set of concise technical performance considerations for nuclear fuel and core components that, if effectively addressed, will reduce the number of fuel and core component related operational issues, increase fuel reliability to achieve and sustain operation with zero defects, and allow increases in fuel burnup to be achieved in future designs with improved margins to thermal and mechanical limits. The technical considerations and recommendations in thi...

2011-01-31T23:59:59.000Z

109

Design of gasifiers to optimize fuel cell systems  

DOE Green Energy (OSTI)

The objective of this program is to configure coal gasification/carbonate fuel cell systems that can significantly improve the economics, performance, and efficiency of electric power generation systems. During this quarter the topical report covering Tasks 1, 2, and 3 was submitted. this study evaluates various catalytic gasification/fuel cell power plant configurations. The competitive position of the configurations are assessed in a comparison with present-day as well as emerging alternate coal-based power plant technologies. The work plan for Task 4, Experimental Studies, was also submitted this quarter. This plan outlines the series of tests which will evaluate the feasibility of using the disposable gasification catalysts recommended in Task 3 of this program. (VC)

Not Available

1992-01-01T23:59:59.000Z

110

Design and fuel management of PWR cores to optimize the once-through fuel cycle  

SciTech Connect

The once-through fuel cycle has been analyzed to see if there are substantial prospects for improved uranium ore utilization in current light water reactors, with a specific focus on pressurized water reactors. The types of changes which have been examined are: (1) re-optimization of fuel pin diameter and lattice pitch, (2) axial power shaping by enrichment gradation in fresh fuel, (3) use of 6-batch cores with semi-annual refueling, (4) use of 6-batch cores with annual refueling, hence greater extended (approximately doubled) burnup, (5) use of radial reflector assemblies, (6) use of internally heterogeneous cores (simple seed/blanket configurations), (7) use of power/temperature coastdown at the end of life to extend burnup, (8) use of metal or diluted oxide fuel, (9) use of thorium, and (10) use of isotopically separated low sigma/sub a/ cladding material. State-of-the-art LWR computational methods, LEOPARD/PDQ-7/FLARE-G, were used to investigate these modifications.

Fujita, E.K.; Driscoll, M.J.; Lanning, D.D.

1978-08-01T23:59:59.000Z

111

The AMP (Advanced MultiPhysics) Nuclear Fuel Performance Code  

Science Conference Proceedings (OSTI)

The AMP (Advanced MultiPhysics) Nuclear Fuel Performance code is a new, three-dimensional, multi-physics tool that uses state-of-the-art solution methods and validated nuclear fuel models to simulate the nominal operation and anticipated operational transients of nuclear fuel. The AMP Nuclear Fuel Performance code leverages existing validated material models from traditional fuel performance codes and the Scale/ORIGEN-S spent-fuel characterization code to provide an initial capability that is shown to be sufficiently accurate for a single benchmark problem and anticipated to be accurate for a broad range of problems. The thermomechanics-chemical foundation can be solved in a time-dependent or quasi-static approach with any variation of operator-split or fully-coupled solutions at each time step. The AMP Nuclear Fuel Performance code provides interoperable interfaces to leading computational mathematics tools, which will simplify the integration of the code into existing parallel code suites for reactor simulation or lower-length-scale coupling. A baseline validation of the AMP Nuclear Fuel Performance code has been performed through the modeling of an experiment in the Halden Reactor Project (IFA-432), which is the first validation problem incorporated in the FRAPCON Integral Assessment report.

Clarno, Kevin T [ORNL; Philip, Bobby [ORNL; Cochran, Bill [ORNL; Sampath, Rahul S [ORNL; Allu, Srikanth [ORNL; Barai, Pallab [ORNL; Simunovic, Srdjan [ORNL; Ott, Larry J [ORNL; Pannala, Sreekanth [ORNL; Dilts, Gary A [ORNL; Mihaila, Bogdan [ORNL; Yesilyurt, Gokhan [ORNL; Lee, Jung Ho [Argonne National Laboratory (ANL); Banfield, James E [ORNL; Berrill, Mark A [ORNL

2012-01-01T23:59:59.000Z

112

OPTIMIZING PERFORMANCE OF THE HESKETT STATION  

SciTech Connect

The overall conclusion from this work is that a switch from river sand bed material to limestone at the R.M. Heskett Station would provide substantial benefits to MDU. A switch to limestone would increase the fuel flexibility of the unit, allowing fuels higher in both sodium and sulfur to be burned. The limestone bed can tolerate a much higher buildup of sodium in the bed without agglomeration, allowing either the bed turnover rate to be reduced to half the current sand feed rate for a fuel with equivalent sodium or allow a higher sodium fuel to be burned with limestone feed rates equivalent to the current sand feed rate. Both stack and ambient SO{sub 2} emissions can be controlled. A small improvement in boiler efficiency should be achievable by operating at lower excess oxygen levels at low load. This reduction in oxygen will also lower NO{sub x} emissions, providing a margin of safety for meeting emission standards. No detrimental effects of using limestone at the Heskett Station were uncovered as a result of the test burn. Some specific conclusions from this work include the following: The bed material feed rate can be reduced from the current rate of 5.4% of the coal feed rate (57.4 tons of sand/day) to 2.5% of the coal feed rate (27 tons of limestone/day). This will result in an annual savings of approximately $200,000. (1) SO{sub 2} emissions at the recommended feed rate would be approximately 250 ppm (0.82 lb/MMBtu) using a similar lignite. Based on the cost of the limestones, SO{sub 2} allowances could be generated at a cost of $60/ton SO{sub 2} , leaving a large profit margin for the sale of allowances. The addition of limestone at the same rate currently used for sand feed could generate $455,000 net income if allowances are sold at $200/ton SO2 . (2) At full-load operation, unburned carbon losses increase significantly at excess oxygen levels below 2.8%. No efficiency gains are expected at high-load operation by switching from sand to limestone. By reducing the oxygen level at low load to 8.5%, an efficiency gain of approximately 1.2% could be realized, equating to $25,000 to $30,000 in annual savings. (3) A reduction of 25 tons/day total ash (bed material plus fly ash) will be realized by using limestone at the recommended feed rate compared to the current sand feed rate. No measurable change in volume would be realized because of the lower bulk density of the limestone-derived material.

Michael D. Mann; Ann K. Henderson

1999-03-01T23:59:59.000Z

113

Seismic performance assessment for structural optimization  

E-Print Network (OSTI)

The economic impact of earthquakes has spurred the implementation of performance-based design to mitigate damage in addition to protecting human lives. A developing trend is to consider damage directly as a measure of ...

Ghisbain, Pierre

2013-01-01T23:59:59.000Z

114

Fuzzy possibilistic modeling and sensitivity analysis for optimal fuel gas scheduling in refinery  

Science Conference Proceedings (OSTI)

In refinery, fuel gas which is continuously generated during the production process is one of the most important energy sources. Optimal scheduling of fuel gas system helps the refinery to achieve energy cost reduction and cleaner production. However, ... Keywords: Fuel gas, Fuzzy possibilistic programming, Marginal value analysis, Refinery, Scheduling, Sensitivity analysis

J. D. Zhang; G. Rong

2010-04-01T23:59:59.000Z

115

Used Nuclear Fuel Loading and Structural Performance Under Normal  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Used Nuclear Fuel Loading and Structural Performance Under Normal Used Nuclear Fuel Loading and Structural Performance Under Normal Conditions of Transport - Modeling, Simulation and Experimental Integration RD&D Plan Used Nuclear Fuel Loading and Structural Performance Under Normal Conditions of Transport - Modeling, Simulation and Experimental Integration RD&D Plan Used nuclear fuel (UNF) must maintain its integrity during the storage period in such a way that it can withstand the physical forces of handling and transportation associated with restaging the fuel and transporting it to treatment or recycling facilities, or to a geologic repository. This RD&D plan describes a methodology, including development and use of analytical models, to evaluate loading and associated mechanical responses of UNF rods and key structural components. The plan objective is to

116

Used Nuclear Fuel Loading and Structural Performance Under Normal  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Nuclear Fuel Loading and Structural Performance Under Normal Nuclear Fuel Loading and Structural Performance Under Normal Conditions of Transport - Modeling, Simulation and Experimental Integration RD&D Plan Used Nuclear Fuel Loading and Structural Performance Under Normal Conditions of Transport - Modeling, Simulation and Experimental Integration RD&D Plan Used nuclear fuel (UNF) must maintain its integrity during the storage period in such a way that it can withstand the physical forces of handling and transportation associated with restaging the fuel and transporting it to treatment or recycling facilities, or to a geologic repository. This RD&D plan describes a methodology, including development and use of analytical models, to evaluate loading and associated mechanical responses of UNF rods and key structural components. The plan objective is to

117

High-performance numerical optimization on multicore clusters  

Science Conference Proceedings (OSTI)

This paper presents a software infrastructure for high performance numerical optimization on clusters of multicore systems. At the core, a runtime system implements a programming and execution environment for irregular and adaptive task-based parallelism. ... Keywords: global optimization, message passing, numerical differentiation, task parallelism

Panagiotis E. Hadjidoukas; Constantinos Voglis; Vassilios V. Dimakopoulos; Isaac E. Lagaris; Dimitris G. Papageorgiou

2011-08-01T23:59:59.000Z

118

Integration and Optimization of Trigeneration Systems with Solar Energy, Biofuels, Process Heat and Fossil Fuels  

E-Print Network (OSTI)

The escalating energy prices and the increasing environmental impact posed by the industrial usage of energy have spurred industry to adopt various approaches to conserving energy and mitigating negative environmental impact. This work aims at developing a systematic approach to integrate solar energy into industrial processes to drive thermal energy transfer systems producing power, cool, and heat. Solar energy is needed to be integrated with other different energy sources (biofuels, fossil fuels, process waste heat) to guarantee providing a stable energy supply, as industrial process energy sources must be a stable and reliable system. The thermal energy transform systems (turbines, refrigerators, heat exchangers) must be selected and designed carefully to provide the energy demand at the different forms (heat, cool, power). This dissertation introduces optimization-based approaches to address the following problems: Design of cogeneration systems with solar and fossil systems Design and integration of solar-biofuel-fossil cogeneration systems Design of solar-assisted absorption refrigeration systems and integration with the processing facility Development of thermally-coupled dual absorption refrigeration systems, and Design of solar-assisted trigeneration systems Several optimization formulations are introduced to provide methodical and systematic techniques to solve the aforementioned problems. The approach is also sequenced into interacting steps. First, heat integration is carried out to minimize industrial heating and cooling utilities. Different forms of external-energy sources (e.g., solar, biofuel, fossil fuel) are screened and selected. To optimize the cost and to overcome the dynamic fluctuation of the solar energy and biofuel production systems, fossil fuel is used to supplement the renewable forms of energy. An optimization approach is adopted to determine the optimal mix of energy forms (fossil, bio fuels, and solar) to be supplied to the process, the system specifications, and the scheduling of the system operation. Several case studies are solved to demonstrate the effectiveness and applicability of the devised procedure. The results show that solar trigeneration systems have higher overall performance than the solar thermal power plants. Integrating the absorption refrigerators improves the energy usage and it provides the process by its cooling demand. Thermal coupling of the dual absorption refrigerators increases the coefficient of performance up to 33 percent. Moreover, the process is provided by two cooling levels.

Tora, Eman

2010-12-01T23:59:59.000Z

119

Strategic Energy Management Through Optimizing the Energy Performance of Buildings  

E-Print Network (OSTI)

1/12/2007 Strategic Energy Management Through Optimizing the Energy Performance of Buildings Oak ambitious federal energy goals and achieve energy independence. The energy engineers, building equipment Buildings and Industrial Energy Efficiency areas has engendered a unique, comprehensive capability

120

Reforming petroleum-based fuels for fuel cell vehicles : composition-performance relationships.  

DOE Green Energy (OSTI)

Onboard reforming of petroleum-based fuels, such as gasoline, may help ease the introduction of fuel cell vehicles to the marketplace. Although gasoline can be reformed, it is optimized to meet the demands of ICEs. This optimization includes blending to increase the octane number and addition of oxygenates and detergents to control emissions. The requirements for a fuel for onboard reforming to hydrogen are quite different than those for combustion. Factors such as octane number and flame speed are not important; however, factors such as hydrogen density, catalyst-fuel interactions, and possible catalyst poisoning become paramount. In order to identify what factors are important in a hydrocarbon fuel for reforming to hydrogen and what factors are detrimental, we have begun a program to test various components of gasoline and blends of components under autothermal reforming conditions. The results indicate that fuel composition can have a large effect on reforming behavior. Components which may be beneficial for ICEs for their octane enhancing value were detrimental to reforming. Fuels with high aromatic and naphthenic content were more difficult to reform. Aromatics were also found to have an impact on the kinetics for reforming of paraffins. The effects of sulfur impurities were dependent on the catalyst. Sulfur was detrimental for Ni, Co, and Ru catalysts. Sulfur was beneficial for reforming with Pt catalysts, however, the effect was dependent on the sulfur concentration.

Kopasz, J. P.; Miller, L. E.; Ahmed, S.; Devlin, P. R.; Pacheco, M.

2001-12-04T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
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121

Optimization of Fuel Cell System Operating Conditions for Fuel Cell Vehicles  

E-Print Network (OSTI)

An Indirect Methanol Pem Fuel Cell System, SAE 2001, (paperof automotive PEM fuel cell stacks, SAE 2000 (paper numberParasitic Loads in Fuel Cell Vehicles, International Journal

Zhao, Hengbing; Burke, Andy

2008-01-01T23:59:59.000Z

122

Configuration and performance of fuel cell-combined cycle options  

DOE Green Energy (OSTI)

The natural gas, indirect-fired, carbonate fuel-cell-bottomed, combined cycle (NG-IFCFC) and the topping natural-gas/solid-oxide fuel-cell combined cycle (NG-SOFCCC) are introduced as novel power-plant systems for the distributed power and on-site markets in the 20-200 mega-watt (MW) size range. The novel NG-IFCFC power-plant system configures the ambient pressure molten-carbonate fuel cell (MCFC) with a gas turbine, air compressor, combustor, and ceramic heat exchanger: The topping solid-oxide fuel-cell (SOFC) combined cycle is not new. The purpose of combining a gas turbine with a fuel cell was to inject pressurized air into a high-pressure fuel cell and to reduce the size, and thereby, to reduce the cost of the fuel cell. Today, the SOFC remains pressurized, but excess chemical energy is combusted and the thermal energy is utilized by the Carnot cycle heat engine to complete the system. ASPEN performance results indicate efficiencies and heat rates for the NG-IFCFC or NG-SOFCCC are better than conventional fuel cell or gas turbine steam-bottomed cycles, but with smaller and less expensive components. Fuel cell and gas turbine systems should not be viewed as competitors, but as an opportunity to expand to markets where neither gas turbines nor fuel cells alone would be commercially viable. Non-attainment areas are the most likely markets.

Rath, L.K.; Le, P.H.; Sudhoff, F.A.

1995-12-31T23:59:59.000Z

123

On Road Fuel Economy Performance of Hybrid Electric Vehicles  

NLE Websites -- All DOE Office Websites (Extended Search)

Road Fuel Economy Performance of Hybrid Electric Vehicles Lee Slezak Office of FreedomCAR and Vehicle Technologies U.S. Department of Energy Jim Francfort Advanced Vehicle Testing...

124

High-density Fuel Development for High Performance Research ...  

Science Conference Proceedings (OSTI)

Abstract Scope, High density UMo (7-12wt% Mo) fuel for high performance research ... High Energy X-ray Diffraction Study of Deformation Behavior of Alloy HT9.

125

Renewable Fuels Module, Appendix - Model Performance, Model Documentation  

Reports and Publications (EIA)

This appendix discusses performance aspects of the Renewable Fuels Module (RFM). It is intended to present the pattern of response of the RFM to typical changes in its major inputs from other NEMS modules.

Perry M. Lindstrom

1995-06-01T23:59:59.000Z

126

Pulverizer performance upgrades lower fuel costs  

Science Conference Proceedings (OSTI)

Between 2002 and 2005, combustion equipment modifications were carried out at St. Johns River Power Plant in Jacksonville, FL. The effort succeeded in obtaining the desired emission reductions and to increase petroleum coke consumption. Since 2005 the boilers typically fired a blend of 70% Colombia coal and 30% delayed petroleum coke. To realize significant fuel savings, the pulverizer capacity was increased by 14% to allow a lower grade coal to be used. The article describes the changes made to the pulverizer to allow 11,800 Btu/pound coal to be burnt, with annual savings of $6.3 m beginning in 2006. 4 figs., 1 tab.

Hansen, T.

2007-05-15T23:59:59.000Z

127

Spent Fuel Transportation Package Performance Study - Experimental Design Challenges  

Science Conference Proceedings (OSTI)

Numerous studies of spent nuclear fuel transportation accident risks have been performed since the late seventies that considered shipping container design and performance. Based in part on these studies, NRC has concluded that the level of protection provided by spent nuclear fuel transportation package designs under accident conditions is adequate. [1] Furthermore, actual spent nuclear fuel transport experience showcase a safety record that is exceptional and unparalleled when compared to other hazardous materials transportation shipments. There has never been a known or suspected release of the radioactive contents from an NRC-certified spent nuclear fuel cask as a result of a transportation accident. In 1999 the United States Nuclear Regulatory Commission (NRC) initiated a study, the Package Performance Study, to demonstrate the performance of spent fuel and spent fuel packages during severe transportation accidents. NRC is not studying or testing its current regulations, a s the rigorous regulatory accident conditions specified in 10 CFR Part 71 are adequate to ensure safe packaging and use. As part of this study, NRC currently plans on using detailed modeling followed by experimental testing to increase public confidence in the safety of spent nuclear fuel shipments. One of the aspects of this confirmatory research study is the commitment to solicit and consider public comment during the scoping phase and experimental design planning phase of this research.

Snyder, A. M.; Murphy, A. J.; Sprung, J. L.; Ammerman, D. J.; Lopez, C.

2003-02-25T23:59:59.000Z

128

Metal Matrix Microencapsulated (M3) fuel neutronics performance in PWRs  

SciTech Connect

Metal Matrix Microencapsulated (M3) fuel consists of TRISO or BISO coated fuel particles directly dispersed in a matrix of zirconium metal to form a solid rod (Fig. 1). In this integral fuel concept the cladding tube and the failure mechanisms associated with it have been eliminated. In this manner pellet-clad-interactions (PCI), thin tube failure due to oxidation and hydriding, and tube pressurization and burst will be absent. M3 fuel, given the high stiffness of the integral rod design, could as well improve grid-to-rod wear behavior. Overall M3 fuel, compared to existing fuel designs, is expected to provide greatly improved operational performance. Multiple barriers to fission product release (ceramic coating layers in the coated fuel particle and te metal matrix) and the high thermal conductivity zirconium alloy metal matrix contribute to the enhancement in fuel behavior. The discontinuous nature of fissile material encapsulated in coated particles provides additional assistance; for instance if the M3 fuel rod is snapped into multiple pieces, only the limited number of fuel particles at the failure cross section are susceptible to release fission products. This is in contrast to the conventional oxide fuel where the presence of a small opening in the cladding provides the pathway for release of the entire inventory of fission products from the fuel rod. While conventional metal fuels (e.g. U-Zr and U-Mo) are typically expected to experience large swelling under irradiation due to the high degree of damage from fission fragments and introduction of fission gas into the lattice, this is not the case for M3 fuels. The fissile portion of the fuel is contained within the coated particle where enough room is available to accommodate fission gases and kernel swelling. The zirconium metal matrix will not be exposed to fission products and its swelling is known to be very limited when exposed solely to neutrons. Under design basis RIA and LOCA, fuel performance will be superior to the conventional oxide fuel since PCMI and rod burst, respectively, have been mitigated. Under beyond design basis accident scenarios where the fuel is exposed to high temperature steam for prolonged periods, larger inventory of zirconium metal in the core could negatively affect the accident progression. A thin steam resistant layer (e.g. alumina forming alloy steel), integrated into the solid rod during fabrication by co-extrusion or hot-isostatic-pressing, offers the potential to provide additional fuel protection from steam interaction: blanketing under a range of boiling regimes and under severe accident conditions up to high temperatures well beyond what is currently possible in the conventional fuel. A crucial aspect to the viability of M3 fuel in light water reactors is the reduced heavy metal load compared to standard pellet fuel. This study evaluated the design requirements to operate a Pressurized Water Reactor (PWR) with M3 fuel in order to obtain fuel cycle length, reactivity coefficients, and power peaking factors comparable to that of standard fuel.

Fratoni, Massimiliano [Pennsylvania State University; Terrani, Kurt A [ORNL

2012-01-01T23:59:59.000Z

129

Fast Reactor Fuel Type and Reactor Safety Performance  

Science Conference Proceedings (OSTI)

Fast Reactor Fuel Type and Reactor Safety Performance R. Wigeland , Idaho National Laboratory J. Cahalan, Argonne National Laboratory The sodium-cooled fast neutron reactor is currently being evaluated for the efficient transmutation of the highly-hazardous, long-lived, transuranic elements that are present in spent nuclear fuel. One of the fundamental choices that will be made is the selection of the fuel type for the fast reactor, whether oxide, metal, carbide, nitride, etc. It is likely that a decision on the fuel type will need to be made before many of the related technologies and facilities can be selected, from fuel fabrication to spent fuel reprocessing. A decision on fuel type should consider all impacts on the fast reactor system, including safety. Past work has demonstrated that the choice of fuel type may have a significant impact on the severity of consequences arising from accidents, especially for severe accidents of low probability. In this paper, the response of sodium-cooled fast reactors is discussed for both oxide and metal fuel types, highlighting the similarities and differences in reactor response and accident consequences. Any fast reactor facility must be designed to be able to successfully prevent, mitigate, or accommodate all consequences of potential events, including accidents. This is typically accomplished by using multiple barriers to the release of radiation, including the cladding on the fuel, the intact primary cooling system, and most visibly the reactor containment building. More recently, this has also included the use of inherent safety concepts to reduce or eliminate the potential for serious damage in some cases. Past experience with oxide and metal fuel has demonstrated that both fuel types are suitable for use as fuel in a sodium-cooled fast reactor. However, safety analyses for these two fuel types have also shown that there can be substantial differences in accident consequences due to the neutronic and thermophysical properties of the fuel and their compatibility with the reactor coolant, with corresponding differences in the challenges presented to the reactor developers. Accident phenomena are discussed for the sodium-cooled fast reactor based on the mechanistic progression of conditions from accident initiation to accident termination, whether a benign state is achieved or more severe consequences are expected. General principles connecting accident phenomena and fuel properties are developed from the oxide and metal fuel safety analyses, providing guidelines that can be used as part of the evaluation for selection of fuel type for the sodium-cooled fast reactor.

R. Wigeland; J. Cahalan

2009-09-01T23:59:59.000Z

130

Design of gasifiers to optimize fuel cell systems. Final report, September 1990--September 1993  

Science Conference Proceedings (OSTI)

Pursuing the key national goal of clean and efficient utilization of the abundant domestic coal resources for power generation, this study was conducted to evaluate the potential of optimizing the integrated catalytic gasification/carbonate fuel cell power generation system. ERC in close collaboration with Fluor Daniel (providing engineering design and costing), conducted a detailed system configuration study to evaluate various catalytic gasification/carbonate fuel cell power plant configurations and compare them to present day, as well as emerging, alternate coal-based power plant technologies to assess their competitive position. A Topical Report (1992) was submitted documenting this effort, and the three catalytic gasification case studies are summarized in Appendix A. Results of this study indicate that system efficiencies approaching 55% (HHV) can be achieved by integrating low temperature catalytic gasification with high efficiency carbonate fuel cells. Thermal balance in the gasifier is achieved without oxygen by recycling hydrogen from the fuel cell anode exhaust. A small amount of air is added to the gasifier to minimize hydrogen recycle. In order to validate the assumptions made in the case configurations, experimental studies were performed to determine the reactivity of Illinois No. 6 coal with the gasification catalysts. The reactivity of the catalyzed coal has significant bearing on gasifier sizing and hence system cost and efficiency.

Not Available

1993-08-01T23:59:59.000Z

131

H-mode fueling optimization with the supersonic deuterium jet in NSTX  

SciTech Connect

High-performance, long-pulse 0.7-1.2 MA 6-7 MW NBI-heated small-ELM H-mode plasma discharges are developed in the National Spherical Torus Experiment (NSTX) as prototypes for confinement and current drive extrapolations to future spherical tori. It is envisioned that innovative lithium coating techniques for H-mode density pumping and a supersonic deuterium jet for plasma refueling will be used to achieve the low pedestal collisionality and low n{sub e}/n{sub G} fractions (0.3-0.6), both of which being essential conditions for maximizing the non-inductive (bootstrap and beam driven) current fractions. The low field side supersonic gas injector (SGI) on NSTX consists of a small converging-diverging graphite Laval nozzle and a piezoelectric gas valve. The nozzle is capable of producing a deuterium jet with Mach number M {le} 4, estimated gas density at the nozzle exit n {le} 5 x 10{sup 23} m{sup -3}, estimated temperature T {ge} 70 K, and flow velocity v = 2:4 km/s. The nozzle Reynolds number Reis {approx_equal} 6000. The nozzle and the valve are enclosed in a protective carbon fiber composite shroud and mounted on a movable probe at a midplane port location. Despite the beneficial L-mode fueling experience with supersonic jets in limiter tokamaks, there is a limited experience with fueling of high-performance H-mode divertor discharges and the associated density, MHD stability, and MARFE limits. In initial supersonic deuterium jet fueling experiments in NSTX, a reliable H-mode access, a low NBI power threshold, P{sub LH} {le} 2 MW, and a high fueling efficiency (0.1-0.4) have been demonstrated. Progress has also been made toward a better control of the injected fueling gas by decreasing the uncontrolled high field side (HFS) injector fueling rate by up to 95 % and complementing it with the supersonic jet fueling. These results motivated recent upgrades to the SGI gas delivery and control systems. The new SGI-Upgrade (SGI-U) capabilities include multi-pulse ms-scale controls and a reservoir gas pressure up to P{sub 0} = 5000 Torr. In this paper we summarize recent progress toward optimization of H-mode fueling in NSTX using the SGI-U.

Soukhanovskii, V A; Bell, M G; Bell, R E; Gates, D A; Kaita, R; Kugel, H W; LeBlanc, B P; Lundberg, D P; Maingi, R; Menard, J E; Raman, R; Roquemore, A L; Stotler, D P

2008-06-18T23:59:59.000Z

132

Optimization of hydride fueled pressurized water reactor cores  

E-Print Network (OSTI)

This thesis contributes to the Hydride Fuels Project, a collaborative effort between UC Berkeley and MIT aimed at investigating the potential benefits of hydride fuel use in light water reactors (LWRs). This pursuit involves ...

Shuffler, Carter Alexander

2004-01-01T23:59:59.000Z

133

Design of gasifiers to optimize fuel cell systems  

DOE Green Energy (OSTI)

The activities in this task are designed to evaluate experimentally the performance of the gasification catalysts chosen for the system study in the first year of this effort. The objectives of this task have been broken down as follows: To experimentally characterize the performance of the previously recommended gasification catalysts for integrates gasification carbonate fuel cell systems as identified in the system study performed during Tasks 1, 2, and 3. The catalysts which will be tested include Potassium carbonates. limestone and taconite in dry form as well as a coal-impregnated with soluble salts of potassium, calcium and iron. To evaluate the degree to which SO[sub 2] in a recycled stream, and or sulfur in the feed, can be captured by the selected calcium or iron containing catalyst at the operation conditions in the catalytic gasifier. To carry out tests under simulated conditions approaching the preferred final process design conditions identified in the system study. The first phase of experimental testing consists of a cost-effective minimum scale screening by Thermogravimetric Analysis (TGA).

Steinfeld, G.

1992-01-01T23:59:59.000Z

134

Optimization of high-performance superscalar architectures for energy efficiency  

Science Conference Proceedings (OSTI)

In recent years reducing power has become a critical design goal for high-performance microprocessors. This work attempts to bring the power issue to the earliest phase of high-performance microprocessor development. We propose a methodology for power-optimization ...

V. Zyuban; P. Kogge

2000-08-01T23:59:59.000Z

135

Final Technical Report, Oct 2004 - Nov. 2006, High Performance Flexible Reversible Solid Oxide Fuel Cell  

SciTech Connect

This report summarizes the work performed for the program entitled High Performance Flexible Reversible Solid Oxide Fuel Cell under Cooperative Agreement DE-FC36-04GO14351 for the U. S. Department of Energy. The overall objective of this project is to demonstrate a single modular stack that generates electricity from a variety of fuels (hydrogen and other fuels such as biomass, distributed natural gas, etc.) and when operated in the reverse mode, produces hydrogen from steam. This project has evaluated and selected baseline cell materials, developed a set of materials for oxygen and hydrogen electrodes, and optimized electrode microstructures for reversible solid oxide fuel cells (RSOFCs); and demonstrated the feasibility and operation of a RSOFC multi-cell stack. A 10-cell reversible SOFC stack was operated over 1000 hours alternating between fuel cell (with hydrogen and methane as fuel) and steam electrolysis modes. The stack ran very successfully with high power density of 480 mW/cm2 at 0.7V and 80% fuel utilization in fuel cell mode and >6 SLPM hydrogen production in steam electrolysis mode using about 1.1 kW electrical power. The hydrogen generation is equivalent to a specific capability of 2.59 Nm3/m2 with electrical energy demand of 3 kWh/Nm3. The performance stability in electrolysis mode was improved vastly during the program with a degradation rate reduction from 8000 to 200 mohm-cm2/1000 hrs. This was accomplished by increasing the activity and improving microstructure of the oxygen electrode. Both cost estimate and technology assessment were conducted. Besides the flexibility running under both fuel cell mode and electrolysis mode, the reversible SOFC system has the potentials for low cost and high efficient hydrogen production through steam electrolysis. The cost for hydrogen production at large scale was estimated at ~$2.7/kg H2, comparing favorably with other electrolysis techology.

Guan, Jie; Minh, Nguyen

2007-02-21T23:59:59.000Z

136

Building Distributed Energy Performance Optimization for China - a Regional  

NLE Websites -- All DOE Office Websites (Extended Search)

Distributed Energy Performance Optimization for China - a Regional Distributed Energy Performance Optimization for China - a Regional Analysis of Building Energy Costs and CO2 Emissions Title Building Distributed Energy Performance Optimization for China - a Regional Analysis of Building Energy Costs and CO2 Emissions Publication Type Conference Proceedings Refereed Designation Refereed LBNL Report Number LBNL-81770 Year of Publication 2012 Authors Feng, Wei, Nan Zhou, Chris Marnay, Michael Stadler, and Judy Lai Conference Name 2012 ACEEE Summer Study on Energy Efficiency in Buildings, August 12-17, 2012 Date Published 08/2012 Conference Location Pacific Grove, California ISBN Number 0-918249-XX-X Notes LBNL - XXXXX Refereed Designation Refereed Attachment Size PDF 5 MB Google Scholar BibTex RIS RTF XML Alternate URL: http://eetd.lbl.gov/node/52998

137

Effects of electrode compression on the performance of a solid polymer electrolyte fuel cell  

E-Print Network (OSTI)

The effects of electrode compression on the performance of a polymer electrolyte fuel cell (PEFC) were investigated. Preliminary testing showed that considerable compression of the carbon cloth electrodes was provided by the PEFC structure. Further, the level of electrode compression was identified as a design parameter having a possible effect on the properties of the electrodes as well as the performance of the PEFC system. Performance-affecting properties of the carbon cloth electrode material, such as electrical conductivity and porosity, were determined over a range of compression levels. Compression was found to have a significant effect on the electrical conductivity and porosity of the carbon cloth electrode material, justifying further testing to measure the effects of electrode compression on PEFC performance. A new PEFC structure was developed which provided uniform mechanical pressure distribution over the area of the electrodes and allowed determination of the level of electrode compression. Utilizing this structure, several fuel cell systems were operated under various levels of electrode compression, and their electrical power output was measured using a linear-sweep voltammetry technique. Fuel cells of two different sizes using two different cathodic reactants--pure oxygen and air--were tested. Results of these experiments were plotted in a manner to illustrate the effect of electrode compression on PEFC performance. Electrode compression was found to have a significant effect on the performance of the PEFC systems observed in this investigation. A level of electrode compression was found for each fuel cell configuration which provided optimal performance. It was concluded from the findings of this work that the performance of PEFC systems utilizing porous carbon cloth electrodes is significantly affected by the level of compression placed on the electrodes. It was further concluded that an electrode compression level exists for PEFC systems which provides optimal performance under a given set of operating conditions.

Del Campo, Christopher Scott

1997-01-01T23:59:59.000Z

138

The Fuel Accident Condition Simulator (FACS) furnace system for high temperature performance testing of VHTR fuel  

SciTech Connect

The AGR-1 irradiation of TRISO-coated particle fuel specimens was recently completed and represents the most successful such irradiation in US history, reaching peak burnups of greater than 19% FIMA with zero failures out of 300,000 particles. An extensive post-irradiation examination (PIE) campaign will be conducted on the AGR-1 fuel in order to characterize the irradiated fuel properties, assess the in-pile fuel performance in terms of coating integrity and fission metals release, and determine the fission product retention behavior during high temperature safety testing. A new furnace system has been designed, built, and tested to perform high temperature accident tests. The Fuel Accident Condition Simulator furnace system is designed to heat fuel specimens at temperatures up to 2000 degrees C in helium while monitoring the release of volatile fission metals (e.g. Cs, Ag, Sr, and Eu), iodine, and fission gases (Kr, Xe). Fission gases released from the fuel to the sweep gas are monitored in real time using dual cryogenic traps fitted with high purity germanium detectors. Condensable fission products are collected on a plate attached to a water-cooled cold finger that can be exchanged periodically without interrupting the test. Analysis of fission products on the condensation plates involves dry gamma counting followed by chemical analysis of selected isotopes. This paper will describe design and operational details of the Fuel Accident Condition Simulator furnace system and the associated fission gas monitoring system, as well as preliminary system calibration results.

Paul A. Demkowicz; David V. Laug; Dawn M. Scates; Edward L. Reber; Lyle G. Roybal; John B. Walter; Jason M. Harp; Robert N. Morris

2012-10-01T23:59:59.000Z

139

Metallic Fuel Casting Development and Parameter Optimization Simulations  

SciTech Connect

One of the advantages of metallic fuel is the abilility to cast the fuel slugs to near net shape with little additional processing. However, the high aspect ratio of the fuel is not ideal for casting. EBR-II fuel was cast using counter gravity injection casting (CGIC) but, concerns have been raised concerning the feasibility of this process for americium bearing alloys. The Fuel Cycle Research and Development program has begun developing gravity casting techniques suitable for fuel production. Compared to CGIC gravity casting does not require a large heel that then is recycled, does not require application of a vacuum during melting, and is conducive to re-usable molds. Development has included fabrication of two separate benchscale, approximately 300 grams, systems. To shorten development time computer simulations have been used to ensure mold and crucible designs are feasible and to identify which fluid properties most affect casting behavior and therefore require more characterization.

R.S. Fielding; J. Crapps; C. Unal; J.R. Kennedy

2013-03-01T23:59:59.000Z

140

High-alcohol microemulsion fuel performance in a diesel engine  

DOE Green Energy (OSTI)

Incidence of methanol use in diesel engines is increasing rapidly due to the potential to reduce both diesel particulate emissions and petroleum consumption. Because simple alcohols and conventional diesel fuel are normally immiscible, most tests to date have used neat to near-neat alcohol, or blends incorporating surfactants or other alcohols. Alcohol's poor ignition quality usually necssitates the use of often expensive cetane enhancers, full-time glow plugs, or spark assist. Reported herein are results of screening tests of clear microemulsion and micellar fuels which contain 10 to 65% C{sub 1}--C{sub 4} alcohol. Ignition performance and NO emissions were measured for clear, stable fuel blends containing alcohols, diesel fuel and additives such as alkyl nitrates, acrylic acids, and several vegetable oil derivatives. Using a diesel engine calibrated with reference fuels, cetane numbers for fifty four blends were estimated. The apparent cetane numbers ranged from around 20 to above 50 with the majority between 30 and 45. Emissions of nitric oxide were measured for a few select fuels and were found to be 10 to 20% lower than No. 2 diesel fuel. 36 refs., 87 figs., 8 tabs.

West, B.H.; Compere, A.L.; Griffith, W.L.

1990-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Spent nuclear fuel storage -- Performance tests and demonstrations  

SciTech Connect

This report summarizes the results of heat transfer and shielding performance tests and demonstrations conducted from 1983 through 1992 by or in cooperation with the US Department of Energy (DOE), Office of Commercial Radioactive Waste Management (OCRWM). The performance tests consisted of 6 to 14 runs involving one or two loadings, usually three backfill environments (helium, nitrogen, and vacuum backfills), and one or two storage system orientations. A description of the test plan, spent fuel load patterns, results from temperature and dose rate measurements, and fuel integrity evaluations are contained within the report.

McKinnon, M.A.; DeLoach, V.A.

1993-04-01T23:59:59.000Z

142

Final assessment of MOX fuel performance experiment with Japanese PWR specification fuel in the HBWR  

Science Conference Proceedings (OSTI)

In order to obtain high burn-up MOX fuel irradiation performance data, SBR and MIMAS MOX fuel rods with Pu-fissile enrichment of about 6 wt% had been irradiated in the HBWR from 1995 to 2006. The peak burn-up of MOX pellet achieved 72 GWd/tM. In this test, fuel centerline temperature, rod internal pressure, stack length and cladding length were measured for MOX fuel and UO{sub 2} fuel as reference. MOX fuel temperature is confirmed to have no significant difference in comparison with UO{sub 2}, taking into account of adequate thermal conductivity degradation due to PuO{sub 2} addition and burn-up development. And the measured fuel temperature agrees well with FINE code calculation up to high burn-up region. Fission gas release of MOX is possibly greater than UO{sub 2} based on temperature and pressure assessment. No significant difference is confirmed between SBR and MIMAS MOX on FGR behavior. MOX fuel swelling rate agrees well with solid swelling rate in the literature. Cladding elongation data shows onset of PCMI in high power region. (authors)

Fujii, Hajime; Teshima, Hideyuki; Kanasugi, Katsumasa [Mitsubishi Heavy Industries, Ltd., 1-1, Wadasaki-cho 1-chome, Hyogo-ku, Kobe 652-8585 (Japan); Kosaka, Yuji [Nuclear Development Corporation, 622-12 Funaishikawa, Tokai-mura, Ibaraki 319-1111 (Japan); Arakawa, Yasushi [The Kansai Electric Power Co., Inc., 8 Yokota, 13 Goichi, Mihama-cho, Mikata-gun, Fukui, 919-1141 (Japan)

2007-07-01T23:59:59.000Z

143

Optimizing Energy Management Strategy and Degree of Hybridization for a Hydrogen Fuel Cell SUV  

E-Print Network (OSTI)

Previous work examined degree of hybridization on the fuel economy of a hybrid electric sport utility vehicle. It was observed that not only was the vehicle control strategy important, but that its definition should be coupled with the component sizing process. Both degree of hybridization and the energy management strategy have been optimized simultaneously in this study. Simple mass scaling algorithms were employed to capture the effect of component and vehicle mass variations as a function of degree of hybridization. Additionally, the benefits of regenerative braking and power buffering have been maximized using optimization methods to determine appropriate battery pack sizing. Both local and global optimization routines were applied to improve the confidence in the solution being close to the true optimum. An optimal configuration and energy management strategy that maximizes the benefit of hybridization for a hydrogen fuel cell hybrid SUV was derived. The optimal configuration was explored, and sensitivity to drive cycle in the optimization process was studied.

Keith Wipke Tony; Tony Markel; Doug Nelson

2001-01-01T23:59:59.000Z

144

Fuel Cell Power Model for CHP and CHHP Economics and Performance Analysis (Presentation)  

DOE Green Energy (OSTI)

This presentation describes the fuel cell power model for CHP and CHHP economics and performance analysis.

Steward, D.; Penev, M.

2010-03-30T23:59:59.000Z

145

The manufacture and performance of homogeneous microstructure SBR MOX fuel  

Science Conference Proceedings (OSTI)

In the early 1980's, British experience in the manufacture of mixed-oxide fast reactor fuel was used to develop a new thermal MOX manufacturing route called the Short Binder-less Route (SBR). Laboratory- scale development led to the manufacture of commercial PWR fuel in a small pilot plant, and the construction of the full-scale dual-line Sellafield MOX Plant (SMP). SMP's first MOX assemblies are now under irradiation. SBR MOX is manufactured with 100% co-milled feedstock, leading to a microstructure dominated by a solid solution of (U,Pu)O{sub 2} at the nominal enrichment. A comprehensive fuel performance research programme has demonstrated the benign performance of SBR MOX up to 54 MWd/kgHM. In particular, the homogeneous microstructure is believed to be instrumental in the favourable fission gas retention and PCI resistance properties. (authors)

Barker, Matthew A. [Nexia Solutions Ltd., British Technology Centre, Sellafield, CA20 1PG (United Kingdom); Stephenson, Keith; Weston, Rebecca [Sellafield Ltd., B582, Sellafield, CA20 1PG (United Kingdom)

2007-07-01T23:59:59.000Z

146

MODELING THE PERFORMANCE OF HIGH BURNUP THORIA AND URANIA PWR FUEL  

E-Print Network (OSTI)

Fuel performance models have been developed to assess the performance of ThO[subscript 2]-UO[subscript 2]

Long, Y.

147

Handbook of SiC Properties for Fuel Performance Modeling  

SciTech Connect

The SiC layer integrity in the TRISO-coated gas-reactor fuel particle is critical to the performance, allowed burn-up, and hence intrinsic efficiency of high temperature gas cooled reactors. While there has been significant developmental work on manufacturing the fuel particles, detailed understanding of what effects the complex in-service stress state combined with realistic materials property data under irradiation has on fuel particle survival is not adequately understood. This fact particularly frustrates the modeling efforts that seek to improve fuel performance through basic understanding. In this work the properties of SiC in the non-irradiated and irradiated condition are reviewed and analyzed in terms of applicability to TRISO fuel modeling. In addition to a review of literature data, new data has been generated to fill-in holes in the existing database, specifically in the high-temperature irradiation regime. Another critical piece of information, the strength of the SiC/Pyrolytic carbon interface, is measured and a formalism for its analysis presented. Finally, recommended empirical treatments of the data are suggested.

Snead, Lance Lewis [ORNL; Nozawa, Takashi [ORNL; Katoh, Yutai [ORNL; Byun, Thak Sang [ORNL; Kondo, Sosuke [ORNL; Petti, David [Idaho National Laboratory (INL)

2007-01-01T23:59:59.000Z

148

Predictive Bias and Sensitivity in NRC Fuel Performance Codes  

SciTech Connect

The latest versions of the fuel performance codes, FRAPCON-3 and FRAPTRAN were examined to determine if the codes are intrinsically conservative. Each individual model and type of code prediction was examined and compared to the data that was used to develop the model. In addition, a brief literature search was performed to determine if more recent data have become available since the original model development for model comparison.

Geelhood, Kenneth J.; Luscher, Walter G.; Senor, David J.; Cunningham, Mitchel E.; Lanning, Donald D.; Adkins, Harold E.

2009-10-01T23:59:59.000Z

149

Performance optimization of the go-back-N ARQ protocols over broadcast channels  

Science Conference Proceedings (OSTI)

Keywords: broadcast channels, go-back-N ARQ, performance optimization, point-to-multipoint communication, protocols

Jonathan L. Wang; John A. Silvester

1991-09-01T23:59:59.000Z

150

PLUTONIUM PROCESSING OPTIMIZATION IN SUPPORT OF THE MOX FUEL PROGRAM  

SciTech Connect

After Los Alamos National Laboratory (LANL) personnel completed polishing 125 Kg of plutonium as highly purified PuO{sub 2} from surplus nuclear weapons, Duke, COGEMA, Stone, and Webster (DCS) required as the next process stage, the validation and optimization of all phases of the plutonium polishing flow sheet. Personnel will develop the optimized parameters for use in the upcoming 330 kg production mission.

GRAY, DEVIN W. [Los Alamos National Laboratory; COSTA, DAVID A. [Los Alamos National Laboratory

2007-02-02T23:59:59.000Z

151

Analytical performance of direct-hydrogen-fueled polymer electrolyte fuel cell (PEFC) systems for transportation applications.  

DOE Green Energy (OSTI)

The performance of a stand-alone polymer electrolyte fuel cell (PEFC) system directly fueled by hydrogen has been evaluated for transportation vehicles. The study was carried out using a systems analysis code and a vehicle analysis code. The systems code includes models for the various PEFC components and is applicable for steady-state and transient situations. At the design point the system efficiency is above 50% for a 50-kW system. The efficiency improves under partial load and approaches 60% at 40% load, as the fuel cell operating point moves to lower current densities on the V-I polarization curve. At much lower loads, the system efficiency drops because of the deterioration in the performance of the compressor, expander, and eventually the fuel cell. The system performance suffers at lower temperatures, as the V-I characteristic curve for the fuel cell shifts downward because of the increased ohmic losses. The results of the transient analysis indicate that the hydrogen-fueled PEFC system can start rather rapidly, within seconds from ambient conditions. However, the warm-up time constant to reach the design operating temperatures is about 180 s. It is important during this period for the coolant to bypass the system radiator until the coolant temperature approaches the design temperature for the fuel cell. The systems analysis code has been applied to two mid-size vehicles: the near-term Ford AIV Sable and the future P2000 vehicle. The results of this study show that the PEFC system in these vehicles can respond well to the demands of the FUDS and Highway driving cycles, with both warm and cold starting conditions. The results also show that the fuel-cell AIV Sable vehicle has impressive gains in fuel economy over that of the internal combustion engine vehicle. However, this vehicle will not be able to meet the PNGV goal of 80 mpg. On the other hand, the P2000 vehicle approaches this goal with variable efficiency of the compressor and expander. It is expected to exceed that goal by a big margin, if the efficiency of the compressor and expander can be maintained constant (at 0.8) over the power range of the fuel cell system.

Doss, E. D.

1998-06-02T23:59:59.000Z

152

Assessment of innovative fuel designs for high performance light water reactors  

E-Print Network (OSTI)

To increase the power density and maximum allowable fuel burnup in light water reactors, new fuel rod designs are investigated. Such fuel is desirable for improving the economic performance light water reactors loaded with ...

Carpenter, David Michael

2006-01-01T23:59:59.000Z

153

Multidisciplinary Modeling, Control, and Optimization of a Solid Oxide Fuel Cell/Gas Turbine Hybrid Power System.  

E-Print Network (OSTI)

??This thesis describes a systematical study, including multidisciplinary modeling, simulation, control, and optimization, of a fuel cell - gas turbine hybrid power system that aims (more)

Abbassi Baharanchi, Atid

2009-01-01T23:59:59.000Z

154

Optimum Performance of Direct Hydrogen Hybrid Fuel Cell Vehicles  

E-Print Network (OSTI)

in batteries, ultracapacitors, fuel cells and hybrid vehicleBattery, Hybrid and Fuel Cell Electric Vehicle SymposiumBattery, Hybrid and Fuel Cell Electric Vehicle Symposium

Zhao, Hengbing; Burke, Andy

2009-01-01T23:59:59.000Z

155

A Micro-Computer-Based Fuel Optimization System Utilizing In-Situ Measurement of Carbon Monoxide  

E-Print Network (OSTI)

A microcomputer-based control system utilizing a distributed intelligence architecture has been developed to control combustion in hydrocarbon fuel-fired boilers and heaters to significantly reduce fuel usage. The system incorporates a unique flue gas analyzer that mounts directly in the flue or stack to continuously measure carbon monoxide, unburned hydrocarbons, opacity and temperature. The control console interfaces directly with the boiler's existing analog control system to provide precise air fuel ratio control based on carbon monoxide measurements. Significant decreases in excess air result in reduced fuel usage while meeting steam demand. Actual performance on industrial boilers shows increases in efficiency of from 1% to 3% with substantial fuel savings.

DeVivo, D. G.

1980-01-01T23:59:59.000Z

156

Design and fuel management of PWR cores to optimize the once-through fuel cycle  

E-Print Network (OSTI)

The once-through fuel cycle has been analyzed to see if there are substantial prospects for improved uranium ore utilization in current

Fujita, Edward Kei

157

Demonstration of dissociated methanol as an automotive fuel: system performance  

DOE Green Energy (OSTI)

The results are presented of system performance testing of an automotive system devised to provide hydrogen-rich gases to an internal combustion engine by dissociating methanol on board the vehicle. The dissociation of methanol absorbs heat from the engine exhaust and increases the lower heating value of the fuel by 22%. The engine thermal efficiency is increased by raising the compression ratio and burning with excess air.

Finegold, J. G.; Karpuk, M. E.; McKinnon, J. T.; Passamaneck, R.

1981-04-01T23:59:59.000Z

158

Alloy Optimization for Metallic Inert Matrix Nuclear Fuels  

Science Conference Proceedings (OSTI)

Conference Tools for 2011 TMS Annual Meeting & Exhibition ... Computational optimization based on coupling between thermodynamic software and a global constrained search ... Prepared by LLNL under Contract DE-AC52-07NA27344. ... of TIG Welded and Laser-surface Melted SUS 304 for Nuclear Power Plants.

159

TRISO Fuel Performance: Modeling, Integration into Mainstream Design Studies, and Application to a Thorium-fueled Fusion-Fission Hybrid Blanket  

SciTech Connect

This study focused on creating a new tristructural isotropic (TRISO) coated particle fuel performance model and demonstrating the integration of this model into an existing system of neutronics and heat transfer codes, creating a user-friendly option for including fuel performance analysis within system design optimization and system-level trade-off studies. The end product enables both a deeper understanding and better overall system performance of nuclear energy systems limited or greatly impacted by TRISO fuel performance. A thorium-fueled hybrid fusion-fission Laser Inertial Fusion Energy (LIFE) blanket design was used for illustrating the application of this new capability and demonstrated both the importance of integrating fuel performance calculations into mainstream design studies and the impact that this new integrated analysis had on system-level design decisions. A new TRISO fuel performance model named TRIUNE was developed and verified and validated during this work with a novel methodology established for simulating the actual lifetime of a TRISO particle during repeated passes through a pebble bed. In addition, integrated self-consistent calculations were performed for neutronics depletion analysis, heat transfer calculations, and then fuel performance modeling for a full parametric study that encompassed over 80 different design options that went through all three phases of analysis. Lastly, side studies were performed that included a comparison of thorium and depleted uranium (DU) LIFE blankets as well as some uncertainty quantification work to help guide future experimental work by assessing what material properties in TRISO fuel performance modeling are most in need of improvement. A recommended thorium-fueled hybrid LIFE engine design was identified with an initial fuel load of 20MT of thorium, 15% TRISO packing within the graphite fuel pebbles, and a 20cm neutron multiplier layer with beryllium pebbles in flibe molten salt coolant. It operated at a system power level of 2000 MW{sub th}, took about 3.5 years to reach full plateau power, and was capable of an End of Plateau burnup of 38.7 %FIMA if considering just the neutronic constraints in the system design; however, fuel performance constraints led to a maximum credible burnup of 12.1 %FIMA due to a combination of internal gas pressure and irradiation effects on the TRISO materials (especially PyC) leading to SiC pressure vessel failures. The optimal neutron spectrum for the thorium-fueled blanket options evaluated seemed to favor a hard spectrum (low but non-zero neutron multiplier thicknesses and high TRISO packing fractions) in terms of neutronic performance but the fuel performance constraints demonstrated that a significantly softer spectrum would be needed to decrease the rate of accumulation of fast neutron fluence in order to improve the maximum credible burnup the system could achieve.

Powers, J J

2011-11-28T23:59:59.000Z

160

Optimum Performance of Direct Hydrogen Hybrid Fuel Cell Vehicles  

E-Print Network (OSTI)

of an experimental fuel cell/supercapacitor-powered hybridof fuel cell/battery/supercapacitor hybrid power source for

Zhao, Hengbing; Burke, Andy

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Fuel Cell/Gas Turbine System Performance Studies  

Office of Scientific and Technical Information (OSTI)

METC/C-97/7278 METC/C-97/7278 Title: Fuel Cell/Gas Turbine System Performance STudies Authors: George T. Lee (METC) Frederick A. Sudhoff (METC) Conference: Fuel Cells '96 Review Meeting Conference Location: Morgantown, West Virginia Conference Dates: August 20-21, 1996 Conference Sponsor: U.S. DOE, Morgantown Energy Technology Center Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference

162

An integrated performance model for high temperature gas cooled reactor coated particle fuel  

E-Print Network (OSTI)

The performance of coated fuel particles is essential for the development and deployment of High Temperature Gas Reactor (HTGR) systems for future power generation. Fuel performance modeling is indispensable for understanding ...

Wang, Jing, 1976-

2004-01-01T23:59:59.000Z

163

Modelling and Design Optimization of Low Speed Fuel Cell Hybrid Electric Vehicles  

E-Print Network (OSTI)

of emissions to global climate change. Although electric cars and buses have been the focus of much of electricModelling and Design Optimization of Low Speed Fuel Cell Hybrid Electric Vehicles by Matthew Blair Supervisors: Dr. Zuomin Dong ABSTRACT Electric vehicles, as an emerging transportation platform, have been

Victoria, University of

164

New Optimal Sensor Suite for Ultrahigh Temperature Fossil Fuel Applications  

DOE Green Energy (OSTI)

Accomplishments during Phase II of a program to develop and demonstrate photonic sensor technology for the instrumentation of advanced powerplants are described. The goal of this project is the research and development of advanced, robust photonic sensors based on improved sapphire optical waveguides, and the identification and demonstration of applications of the new sensors in advanced fossil fuel power plants, where the new technology will contribute to improvements in process control and monitoring. During this program work period, major progress has been experienced in the development of the sensor hardware, and the planning of the system installation and operation. The major focus of the next work period will be the installation of sensors in the Hamilton, Ohio power plant, and demonstration of high-temperature strain gages during mechanical testing of SOFC components.

John Coggin; Jonas Ivasauskas; Russell G. May; Michael B. Miller; Rena Wilson

2006-09-30T23:59:59.000Z

165

NERSC and HDF Group Optimize HDF5 Library to Improve I/O Performance  

NLE Websites -- All DOE Office Websites (Extended Search)

and HDF Group Optimize HDF5 Library to Improve IO Performance NERSC and HDF Group Optimize HDF5 Library to Improve IO Performance June 28, 2010 A common complaint among air...

166

Irradiation performance of low-enriched uranium fuel elements  

SciTech Connect

The status of the testing and evaluation of full-sized experimental low- and medium-enriched uranium fuel elements in the Oak Ridge Research Reactor is presented. Medium-enriched elements containing oxide and aluminide have been completely evaluated at burnups up to 75%. A low-enriched U/sub 3/Si/sub 2/ element has been evaluated at 41% burnup. Other silicide and oxide elements have completed irradiation satisfactorily to burnups of 75% and are now being evaluated. All results to date confirm the expected good performance of these elements in the medium power research reactor environment.

Copeland, G.L.; Hofman, G.L.; Snelgrove, J.L.

1984-10-14T23:59:59.000Z

167

Optimum Performance of Direct Hydrogen Hybrid Fuel Cell Vehicles  

E-Print Network (OSTI)

capacitors fuel-cell hybrid electric vehicle optimizationsize for fuel cell hybrid electric vehicle-Part I, Journalbeen developed for hybrid electric vehicles with an internal

Zhao, Hengbing; Burke, Andy

2009-01-01T23:59:59.000Z

168

Optimizing small wind turbine performance in battery charging applications  

Science Conference Proceedings (OSTI)

Many small wind turbine generators (10 kW or less) consist of a variable speed rotor driving a permanent magnet synchronous generator (alternator). One application of such wind turbines is battery charging, in which the generator is connected through a rectifier to a battery bank. The wind turbine electrical interface is essentially the same whether the turbine is part of a remote power supply for telecommunications, a standalone residential power system, or a hybrid village power system, in short, any system in which the wind generator output is rectified and fed into a DC bus. Field experience with such applications has shown that both the peak power output and the total energy capture of the wind turbine often fall short of expectations based on rotor size and generator rating. In this paper, the authors present a simple analytical model of the typical wind generator battery charging system that allows one to calculate actual power curves if the generator and rotor properties are known. The model clearly illustrates how the load characteristics affect the generator output. In the second part of this paper, the authors present four approaches to maximizing energy capture from wind turbines in battery charging applications. The first of these is to determine the optimal battery bank voltage for a given WTG. The second consists of adding capacitors in series with the generator. The third approach is to place an optimizing DC/DC voltage converter between the rectifier and the battery bank. The fourth is a combination of the series capacitors and the optimizing voltage controller. They also discuss both the limitations and the potential performance gain associated with each of the four configurations.

Drouilhet, S; Muljadi, E; Holz, R [National Renewable Energy Lab., Golden, CO (United States). Wind Technology Div.; Gevorgian, V [State Engineering Univ. of Armenia, Yerevan (Armenia)

1995-05-01T23:59:59.000Z

169

Compaction Scale Up and Optimization of Cylindrical Fuel Compacts for the Next Generation Nuclear Plant  

Science Conference Proceedings (OSTI)

Multiple process approaches have been used historically to manufacture cylindrical nuclear fuel compacts. Scale-up of fuel compacting was required for the Next Generation Nuclear Plant (NGNP) project to achieve an economically viable automated production process capable of providing a minimum of 10 compacts/minute with high production yields. In addition, the scale-up effort was required to achieve matrix density equivalent to baseline historical production processes, and allow compacting at fuel packing fractions up to 46% by volume. The scale-up approach of jet milling, fluid-bed overcoating, and hot-press compacting adopted in the U.S. Advanced Gas Reactor (AGR) Fuel Development Program involves significant paradigm shifts to capitalize on distinct advantages in simplicity, yield, and elimination of mixed waste. A series of designed experiments have been completed to optimize compaction conditions of time, temperature, and forming pressure using natural uranium oxycarbide (NUCO) fuel. Results from these experiments are included. The scale-up effort is nearing completion with the process installed and operational using nuclear fuel materials. The process is being certified for manufacture of qualification test fuel compacts for the AGR-5/6/7 experiment at the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL).

Jeffrey J. Einerson; Jeffrey A. Phillips; Eric L. Shaber; Scott E. Niedzialek; W. Clay Richardson; Scott G. Nagley

2012-10-01T23:59:59.000Z

170

Achieving Better Building Performance and Savings Using Optimal Control Strategies  

E-Print Network (OSTI)

The Continuous Commissioning (CCSM) process has become a very important energy conservation topic for new and existing commercial buildings. This process can yield substantial operating savings, improved indoor air quality, and enhanced occupant comfort. It also provides solutions to reoccurring building maintenance problems. One tool that can be implemented during commissioning work is a nearoptimal global set point method in an Energy Management Control System (EMCS) Direct Digital Controller (DDC). This algorithm is based on mathematical models for the chillers, boilers, chilled and hot water pumps, and air handler fans that relate the power of these components as a function of the chilled water and hot water differential temperature. The algorithm will minimize the total plant power consumption. These optimal control strategies make the CC process more effective. The Texas A&M University Systems State Headquarters is an office building, with a total floor area of approximately 123,960 ft2. An integrated commissioning of the HVAC systems was performed for this building. This paper describes the commissioning activities and demonstrates how newly developed optimized control strategies improved the building comfort conditions and reduced utility costs during and after the commissioning period.

Chen, H.; Deng, S.; Bruner, H.

2003-01-01T23:59:59.000Z

171

Hybrid Model for Building Performance Diagnosis and Optimal Control  

E-Print Network (OSTI)

Modern buildings require continuous performance monitoring, automatic diagnostics and optimal supervisory control. For these applications, simplified dynamic building models are needed to predict the cooling and heating requirement viewing the building as a whole system. This paper proposes a new hybrid model. Half of the model is represented by detailed physical parameters and another half is described by identified parameters. 3R2C thermal network model, which consists of three resistances and two capacitances, is used to simulate building envelope whose parameters are determined in frequency domain using the theoretical frequency characteristics of the envelope. Internal mass is represented by a 2R2C thermal network model, which consists of three resistances and two capacitances. The resistances and capacitances of the 2R2C model are assumed to be constant. A GA (genetic algorithm)-based method is developed for model parameter identification by searching the optimal parameters of 3R2C models of envelopes in frequency domain and that of the 2R2C model of the building internal mass in time domain. As the model is based on the physical characteristics, the hybrid model can be used to predict the cooling and heating energy consumption of buildings accurately in wide range of operation conditions.

Wang, S.; Xu, X.

2003-01-01T23:59:59.000Z

172

Performance Analysis & Optimization of Well Production in Unconventional Resource Plays  

E-Print Network (OSTI)

The Unconventional Resource Plays consisting of the lowest tier of resources (large volumes and most difficult to develop) have been the main focus of US domestic activity during recent times. Horizontal well drilling and hydraulic fracturing completion technology have been primarily responsible for this paradigm shift. The concept of drainage volume is being examined using pressure diffusion along streamlines. We use diffusive time of flight to optimize the number of hydraulic fracture stages in horizontal well application for Tight Gas reservoirs. Numerous field case histories are available in literature for optimizing number of hydraulic fracture stages, although the conclusions are case specific. In contrast, a general method is being presented that can be used to augment field experiments necessary to optimize the number of hydraulic fracture stages. The optimization results for the tight gas example are in line with the results from economic analysis. The fluid flow simulation for Naturally Fractured Reservoirs (NFR) is performed by Dual-Permeability or Dual-Porosity formulations. Microseismic data from Barnett Shale well is used to characterize the hydraulic fracture geometry. Sensitivity analysis, uncertainty assessment, manual & computer assisted history matching are integrated to develop a comprehensive workflow for building reliable reservoir simulation models. We demonstrate that incorporating proper physics of flow is the first step in building reliable reservoir simulation models. Lack of proper physics often leads to unreasonable reservoir parameter estimates. The workflow demonstrates reduced non-uniqueness for the inverse history matching problem. The behavior of near-critical fluids in Liquid Rich Shale plays defies the production behavior observed in conventional reservoir systems. In conventional reservoirs an increased gas-oil ratio is observed as flowing bottom-hole pressure is less than the saturation pressure. The production behavior is examined by building a compositional simulation model on an Eagle Ford well. Extremely high pressure drop along the multiple transverse hydraulic fractures and high critical gas saturation are responsible for this production behavior. Integrating pore-scale flow modeling (such as Lattice Boltzmann) to the field-scale reservoir simulation may enable quantifying the effects of high capillary pressure and phase behavior alteration due to confinement in the nano-pore system.

Sehbi, Baljit Singh

2013-05-01T23:59:59.000Z

173

Capsule performance optimization in the National Ignition Campaign  

Science Conference Proceedings (OSTI)

A capsule performance optimization campaign will be conducted at the National Ignition Facility [G. H. Miller et al., Nucl. Fusion 44, 228 (2004)] to substantially increase the probability of ignition by laser-driven hohlraums [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)]. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the OMEGA facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

Landen, O. L.; Bradley, D. K.; Braun, D. G.; Callahan, D. A.; Celliers, P. M.; Collins, G. W.; Dewald, E. L.; Divol, L.; Glenzer, S. H.; Hamza, A.; Hicks, D. G.; Izumi, N.; Jones, O. S.; Kirkwood, R. K.; Michel, P.; Milovich, J.; Munro, D. H.; Robey, H. F.; Spears, B. K.; Thomas, C. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2010-05-15T23:59:59.000Z

174

Theory of proton exchange membranes fuel cells and the testing of performance characteristics of polymer electrolyte membranes  

E-Print Network (OSTI)

Proton exchange membrane (PEM) fuel cells hold great promise as source of power. A hydrogen and oxygen PEM fuel is a simple fuel cell that can be theoretically characterized. The performance of a PEM fuel cell can be ...

Cruz-Gonzalez, Tizoc, 1982-

2004-01-01T23:59:59.000Z

175

Influence of Nuclear Fuel Cycles on Uncertainty of Long Term Performance of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Influence of Nuclear Fuel Cycles on Uncertainty of Long Term Influence of Nuclear Fuel Cycles on Uncertainty of Long Term Performance of Geologic Disposal Systems Influence of Nuclear Fuel Cycles on Uncertainty of Long Term Performance of Geologic Disposal Systems Development and implementation of future advanced fuel cycles including those that recycle fuel materials, use advanced fuels different from current fuels, or partition and transmute actinide radionuclides, will impact the waste management system. The Used Fuel Disposition Campaign can reasonably conclude that advanced fuel cycles, in combination with partitioning and transmutation, which remove actinides, will not materially alter the performance, the spread in dose results around the mean, the modeling effort to include significant features, events, and processes

176

Influence of Nuclear Fuel Cycles on Uncertainty of Long Term Performance of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Influence of Nuclear Fuel Cycles on Uncertainty of Long Term Influence of Nuclear Fuel Cycles on Uncertainty of Long Term Performance of Geologic Disposal Systems Influence of Nuclear Fuel Cycles on Uncertainty of Long Term Performance of Geologic Disposal Systems Development and implementation of future advanced fuel cycles including those that recycle fuel materials, use advanced fuels different from current fuels, or partition and transmute actinide radionuclides, will impact the waste management system. The Used Fuel Disposition Campaign can reasonably conclude that advanced fuel cycles, in combination with partitioning and transmutation, which remove actinides, will not materially alter the performance, the spread in dose results around the mean, the modeling effort to include significant features, events, and processes

177

Thermionic Fuel Element performance: TFE Verification Program. Final test report  

DOE Green Energy (OSTI)

The program objective is to demonstrate the technology readiness of a Thermionic Fuel Element (TFE) suitable for use as the basic element in a thermionic reactor with electric power output in the 0.5 to 5.0 MW(e) range, and a full power life of 7 years. A TFE was designed that met the reliability and lifetime requirements for a 2 MW(e) conceptual reactor design. Analysis showed that this TFE could be used over the range of 0.5 to 5 megawatts. This was used as the basis for designing components for test and evaluation. The demonstration of a 7-year component lifetime capability was through the combined use of analytical models and accelerated, confirmatory tests in a fast test reactor. Iterative testing was performed in which the results of one test series led to evolutionary improvements in the next test specimens. The TFE components underwent screening and initial development testing in ex-reactor tests. Several design and materials options were considered for each component. As screening tests permitted, down selection occurred to very specific designs and materials. In parallel with ex-reactor testing, and fast reactor component testing, components were integrated into a TFE and tested in the TRIGA test reactor at GA. Realtime testing of partial length TFEs was used to test support, alignment and interconnective TFE components, and to verify TFE performance in-reactor with integral cesium reservoirs. Realtime testing was also used to verify the relation between TFE performance and fueled emitter swelling, to test the durability of intercell insulation, to check temperature distributions, and to verify the adequacy over time of the fission gas venting channels. Predictions of TFE lifetime rested primarily on the accelerated component testing results, as correlated and extended to realtime by the use of analytical models.

Not Available

1994-06-01T23:59:59.000Z

178

Effect of High Reactor Water Zinc on Fuel Performance in Quad Cities 2  

Science Conference Proceedings (OSTI)

Due to reduction in feedwater Fe, reactor water Zn concentrations have been increasing in U.S. boiling water reactors (BWRs). The fuel performance experience base is limited to 8 to 10 ppb, and no fuel surveillance was performed in a plant operated with greater than 12 ppb reactor water Zn. The impact of high reactor water Zn on fuel performance is unknown. However, the change in the trends is large enough to raise a concern, and it requires a confirmation of the fuel performance with fuel ...

2013-07-02T23:59:59.000Z

179

Investigation of impact of fuel injection strategy and biodiesel fueling on engine emissions and performance.  

E-Print Network (OSTI)

??Both biodiesel fueling and changes of fuel injection pressure have significant impacts on diesel engine emissions. The investigations of their impacts on engine exhaust NOx (more)

Ye, Peng

2011-01-01T23:59:59.000Z

180

Performance assessment of DOE spent nuclear fuel and surplus plutonium  

SciTech Connect

Yucca Mountain, in southern Nevada, is under consideration by the US Department of Energy (DOE) as a potential site for the disposal of the nation`s radioactive wastes in a geologic repository. The wastes consist of commercial spent fuel, DOE spent nuclear fuel (SNF), high level waste (HLW), and surplus plutonium. The DOE was mandated by Congress in the fiscal 1997 Energy and Water Appropriations Act to complete a viability assessment (VA) of the repository in September of 1998. The assessment consists of a preliminary design concept for the critical elements of the repository, a total system performance assessment (TSPA), a plan and cost estimate for completion of the license application, and an estimate of the cost to construct and operate the repository. This paper presents the results of the sensitivity analyses that were conducted to examine the behavior of DOE SNF and plutonium waste forms in the environment of the base case repository that was modeled for the TSPA-VA. Fifteen categories of DOE SNF and two Plutonium waste forms were examined and their contribution to radiation dose to humans was evaluated.

Duguid, J.O.; Vallikat, V.; McNeish, J.

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Water Transport in PEM Fuel Cells: Advanced Modeling, Material Selection, Testing, and Design Optimization  

NLE Websites -- All DOE Office Websites (Extended Search)

in PEM Fuel Cells: in PEM Fuel Cells: Advanced Modeling, Material Selection, Testing, and Design Optimization J. Vernon Cole and Ashok Gidwani CFDRC Prepared for: DOE Hydrogen Fuel Cell Kickoff Meeting February 13, 2007 This presentation does not contain any proprietary or confidential information. Background Water Management Issues Arise From: ƒ Generation of water by cathodic reaction ƒ Membrane humidification requirements ƒ Capillary pressure driven transport through porous MEA and GDL materials ƒ Scaling bipolar plate channel dimensions J.H. Nam and M. Kaviany, Int. J. Heat Mass Transfer, 46, pp. 4595-4611 (2003) Relevant Barriers and Targets ƒ Improved Gas Diffusion Layer, Flow Fields, Membrane Electrode Assemblies Needed to Improve Water Management: * Flooding blocks reactant transport

182

On the use of high performance annular fuel in PWRs  

E-Print Network (OSTI)

Recently, MIT's Center for Advanced Nuclear Energy Systems developed a new high burnup annular fuel that features both internal and external cooling. Implementation of this fuel design in current pressurized water reactors ...

Feng, Bo, Ph. D. Massachusetts Institute of Technology

2008-01-01T23:59:59.000Z

183

Fuel Cell Rebate and Performance Incentive (New York) | Open...  

Open Energy Info (EERE)

with landfill gas, biogas, and anaerobic digester gas are retained by the owner. Program Budget Large Fuel Cells: 21 million (3.5 million annually through 2015) Small Fuel...

184

TRISO Fuel Performance: Modeling, Integration into Mainstream Design Studies, and Application to a Thorium-fueled Fusion-Fission Hybrid Blanket  

E-Print Network (OSTI)

TRISO-coated Particle Nuclear Fuel Performance Models, Rareet al. , A Sustainable Nuclear Fuel Cycle Based on LaserC.D. Heising, Closing the Nuclear Fuel Cycle: Thorium and

Powers, Jeffrey

2011-01-01T23:59:59.000Z

185

Performance Assessment of High Burnup Fuel From Limerick  

Science Conference Proceedings (OSTI)

GE11 design (9x9 lattice) fuel was irradiated to ~52 and ~65 GWd/MTU average bundle exposures at Exelon's Limerick Unit 1 and Limerick Unit 2 reactors. The project goal was to characterize the behavior of modern boiling water reactor (BWR) fuel at exposures beyond current fuel licensing limits. Additionally, the program examined both GE11 and GE13 fuel rods (irradiated to ~51-55 GWd/MTU) to assess the effects of noble metal chemical addition (NMCA) and variations in fuel cladding fabrication processes on...

2008-01-31T23:59:59.000Z

186

Gas Turbine Combustor Performance on Synthetic Fuels, Volume 2  

Science Conference Proceedings (OSTI)

This volume presents a summary of a project to determine the effects of burning currently available coal-derived and shale-derived synthetic liquid fuels in state-of-the-art gas turbine combustors. It describes the fuels tested, the effects of NO emission and of smoke formation and reduction, and a comparison of surrogate and synthetic fuels. The project concluded that a number of selected coal and shale oil fuels can be used in current turbines as soon as these fuels become available.

1981-06-01T23:59:59.000Z

187

Final Report - Effects of Impurities on Fuel Cell Performance and Durability  

DOE Green Energy (OSTI)

This program is focused on the experimental determination of the effects of key hydrogen side impurities on the performance of PEM fuel cells. Experimental data has been leveraged to create mathematical models that predict the performance of PEM fuel cells that are exposed to specific impurity streams. These models are validated through laboratory experimentation and utilized to develop novel technologies for mitigating the effects of contamination on fuel cell performance. Results are publicly disseminated through papers, conference presentations, and other means.

Trent Molter

2012-08-18T23:59:59.000Z

188

NREL UL E15 Fuel Dispensing Infrastructure Intermediate Blends Performance Testing (Presentation)  

DOE Green Energy (OSTI)

Presentation provides an overview of NREL's project to determine compatibility and safe performance of installed fuel dispensing infrastructure with E15.

Moriarty, K.; Clark, W.

2011-02-01T23:59:59.000Z

189

Fuel Cell Power Model for CHHP System Economics and Performance Analysis (Presentation)  

DOE Green Energy (OSTI)

Presentation about Fuel Cell Power (FCPower) Model used to analyze the economics and performance of combined heat, hydrogen, and power (CHHP) systems.

Steward, D.

2009-11-16T23:59:59.000Z

190

Cold-Start and Warm-Up Driveability Performance of Hybrid Electric Vehicles Using Oxygenated Fuels  

DOE Green Energy (OSTI)

Provides analysis and results of the driveability performance testing from four hybrid electric vehicles--Honda Civic, Toyota Prius, and two Honda Insights--that used oxygenated fuels.

Thornton, M.; Jorgensen, S.; Evans, B.; Wright, K.

2003-11-01T23:59:59.000Z

191

Performance of gasoline and diesel fuels produced from COED syncrude  

DOE Green Energy (OSTI)

Fuel consumption and exhaust emissions characteristics were evaluated for gasoline and diesel fuel produced from coal liquid derived syncrude. The engine types used were: (1) current technology spark-ignition, homogeneous charge, (2) stratified-charge, and (3) Stirling. There were no significant changes in fuel consumption or exhaust emissions between syncrude-derived fuels and conventional fuels in stratified-charge and Stirling engines. Because of its low (approximately equal to 70) octane number and volatility, the synthetic gasoline required a reduction in compression ratio to achieve knock-limited, MBT spark timing. This was in comparison to the reference gasoline, in a single-cylinder spark-ignited test engine, at one speed/load point. Exhaust emissions were very similar between the two fuels.

Bechtold, R.L.; Fleming, R.D.

1978-06-01T23:59:59.000Z

192

Fuel Composition Effects and Other Operational Parameters on Solid Oxide Fuel Cell Performance  

NLE Websites -- All DOE Office Websites (Extended Search)

Composition Effects and Other Composition Effects and Other Operational Parameters on Solid Oxide Fuel Cell Performance DOE/NETL-401/093010 September 30, 2010 Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or

193

Effect of carbon coating on scuffing performance in diesel fuels  

DOE Green Energy (OSTI)

Low-sulfur and low-aromatic diesel fuels are being introduced in order to reduce various types of emissions in diesel engines to levels in compliance with current and impending US federal regulations. The low lubricity of these fuels, however, poses major reliability and durability problems for fuel injection components that depend on diesel fuel for their lubrication. In the present study, the authors evaluated the scuff resistance of surfaces in regular diesel fuel containing 500 ppm sulfur and in Fischer-Tropsch synthetic diesel fuel containing no sulfur or aromatics. Tests were conducted with the high frequency reciprocating test rig (HFRR) using 52100 steel balls and H-13 tool-steel flats with and without Argonne's special carbon coatings. Test results showed that the sulfur-containing fuels provide about 20% higher scuffing resistance than does fuel without sulfur. Use of the carbon coating on the flat increased scuffing resistance in both regular and synthetic fuels by about ten times, as measured by the contact severity index at scuffing. Scuffing failure in tests conducted with coated surfaces did not occur until the coating had been removed by the two distinct mechanisms of spalling and wear.

Ajayi, O. O.; Alzoubi, M. F.; Erdemir, A.; Fenske, G. R.

2000-06-29T23:59:59.000Z

194

Optimum Performance of Direct Hydrogen Hybrid Fuel Cell Vehicles  

E-Print Network (OSTI)

batteries and ultracapacitors for electric vehicles. EVS24Battery, Hybrid and Fuel Cell Electric Vehicle Symposiumpublications on electric and hybrid vehicle technology and

Zhao, Hengbing; Burke, Andy

2009-01-01T23:59:59.000Z

195

Optimal design and integration of solar systems and fossil fuels for process cogeneration  

E-Print Network (OSTI)

Because of the fluctuations in incident solar power, outlet power also changes over time (e.g., on an hourly basis or seasonally). If there is a need for a stable power outlet, there are options towards a steady state output of the system. This work is aimed at the development of systematic design procedures for two solar-based power generation strategies. The first is integration of fossil-fuel with the solar system to provide a compensation effect (power backup to supplement the power main source from solar energy). The second is the use of thermal energy storage (TES) systems to save solar energy in a thermal form and use it when solar input decreases. A common TES configuration is the two-tank system which allows the use of the collector heat transfer fluid (HTF) as a storing medium. For the two tanks, one tank has the hot medium (e.g., a molten salt) and the second has the cold storage media. Specifically, the following design challenges are addressed: 1. What is the optimal mix of energy forms to be supplied to the process? 2. What are the optimal scenario and integration mode to deliver the selected energy forms? How should they be integrated among themselves and with the process? 3. What is the optimal design of the energy systems? 4. What is the optimal dynamic strategy for operating the various energy systems? 5. What is the feasibility of using thermal energy storage to this optimum fossil fuel system? The developed procedure includes gathering and generation of relevant solar and climatic data, modeling of the various components of the solar, fossil, and power generation systems, and optimization of several aspects of the hybrid system. A case study is solved to demonstrate the effectiveness and applicability of the devised procedure.

Tora, Eman Abdel-Hakim Aly Mohamed

2008-08-01T23:59:59.000Z

196

Optimizing HVAC Control to Improve Building Comfort and Energy Performance  

E-Print Network (OSTI)

This paper demonstrates the benefits of optimal control in well-designed and operated buildings using a case study. The case study building was built in 2001. The HVAC and control systems have been installed with state-of-the-art equipment which include a terminal box temperature integrated minimum airflow reset. The building has been used and operated based on the design intents. This paper presents both the existing and the optimal control schedules, which include the VAV box operation schedule, AHUs optimal control, chiller and chilled water pump control, and boiler and hot water pump control. The measured hourly HVAC electricity consumption shows that annual savings of up to 40% can be achieved with an optimal control schedule.

Song, L.; Joo, I.; Dong, D.; Liu, M.; Wang, J.; Hansen, K.; Quiroz, L.; Swiatek, A.

2003-01-01T23:59:59.000Z

197

Handoff In Mobile ATM Networks: A Framework for Performance Optimization  

Science Conference Proceedings (OSTI)

Current handoff rerouting techniques in Mobile ATM networks fail to optimize some or all of the following parameters: handoff latency, route length, computational complexity, communication disruption period, network buffer requirements,a nd bandwidth ...

Sirisha R. Medidi; Forouzan Golshani

2002-06-01T23:59:59.000Z

198

Computational Fluid Dynamics Simulation of Steam Reforming and Autothermal Reforming for Fuel Cell Applications.  

E-Print Network (OSTI)

??With the increasing demand for fuel cell applications in transportation, the performance of reformers using gasoline or diesel as the fuel needs to be optimized. (more)

Shi, Liming

2009-01-01T23:59:59.000Z

199

Method of optimizing performance of Rankine cycle power plants  

DOE Patents (OSTI)

A method for efficiently operating a Rankine cycle power plant (10) to maximize fuel utilization efficiency or energy conversion efficiency or minimize costs by selecting a turbine (22) fluid inlet state which is substantially in the area adjacent and including the transposed critical temperature line (46).

Pope, William L. (Walnut Creek, CA); Pines, Howard S. (El Cerrito, CA); Doyle, Padraic A. (Oakland, CA); Silvester, Lenard F. (Richmond, CA)

1982-01-01T23:59:59.000Z

200

Diesel Fuel Sulfur Effects on the Performance of Lean NOx Catalysts  

DOE Green Energy (OSTI)

Evaluate the effects of diesel fuel sulfur on the performance of low temperature and high temperature Lean-NOx Catalysts. Evaluate the effects of up to 250 hours of aging on the performance of the Lean-NOx Catalysts with different fuel sulfur contents.

Ren, Shouxian

2000-08-20T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Fuel performance comparison between Savannah River reactors and the US commercial nuclear reactors  

SciTech Connect

This document provides a review of fuel/target performance of the Savannah River Reactors which was made to compare their in-core performance with that of the commercial nuclear reactors in the US.

Paik, I.K.; Ellison, P.G.

1989-01-01T23:59:59.000Z

202

Fuel Cell Power Model for CHHP System Economics and Performance...  

NLE Websites -- All DOE Office Websites (Extended Search)

heat production (assuming 75% total efficiency for fuel cell) kWhdaycow 4 Finished compost Cubic yardsyear cow 3.32 Electricity required for digester operation kWhcowday 1...

203

Fuel cell/gas turbine system performance studies  

SciTech Connect

Because of the synergistic effects (higher efficiencies, lower emissions) of combining a fuel cell and a gas turbine into a power generation system, many potential system configurations were studied. This work is focused on novel power plant systems by combining gas turbines, solid oxide fuel cells, and a high-temperature heat exchanger; these systems are ideal for the distributed power and on- site markets in the 1-5 MW size range.

Lee, G.T.; Sudhoff, F.A.

1996-12-31T23:59:59.000Z

204

IMPACT OF OXYGENATED FUEL ON DIESEL ENGINE PERFORMANCE AND EMISSIONS  

DOE Green Energy (OSTI)

As evidenced by recent lawsuits brought against operators of large diesel truck fleets [1] and by the Consent Decree brought against the heavy-duty diesel manufacturers [2], the environmental and health effects of diesel engine emissions continue to be a significant concern. Reduction of diesel engine emissions has traditionally been achieved through a combination of fuel system, combustion chamber, and engine control modifications [3]. Catalytic aftertreatment has become common on modern diesel vehicles, with the predominant device being the diesel oxidation catalytic converter [3]. To enable advanced after-treatment devices and to directly reduce emissions, significant recent interest has focused on reformulation of diesel fuel, particularly the reduction of sulfur content. The EPA has man-dated that diesel fuel will have only 15 ppm sulfur content by 2007, with current diesel specifications requiring around 300 ppm [4]. Reduction of sulfur will permit sulfur-sensitive aftertreatment devices, continuously regenerating particulate traps, NOx control catalysts, and plasma assisted catalysts to be implemented on diesel vehicles [4]. Another method of reformulating diesel fuel to reduce emissions is to incorporate oxygen in the fuel, as was done in the reformulation of gasoline. The use of methyl tertiary butyl ether (MTBE) in reformulated gasoline has resulted in contamination of water resources across the country [5]. Nonetheless, by relying on the lessons learned from MTBE, oxygenation of diesel fuel may be accomplished without compromising water quality. Oxygenation of diesel fuel offers the possibility of reducing particulate matter emissions significantly, even for the current fleet of diesel vehicles. The mechanism by which oxygen content leads to particulate matter reductions is still under debate, but recent evidence shows clearly that ''smokeless'' engine operation is possible when the oxygen content of diesel fuel reaches roughly 38% by weight [6]. The potential improvements in energy efficiency within the transportation section, particularly in sport utility vehicles and light-duty trucks, that can be provided by deployment of diesel engines in passenger cars and trucks is a strong incentive to develop cleaner burning diesel engines and cleaner burning fuels for diesel engines. Thus, serious consideration of oxygenated diesel fuels is of significant practical interest and value to society. In the present work, a diesel fuel reformulating agent, CETANERTM, has been examined in a popular light-medium duty turbodiesel engine over a range of blending ratios. This additive is a mixture of glycol ethers and can be produced from dimethyl ether, which itself can be manufactured from synthesis gas using Air Products' Liquid Phase Dimethyl Ether (LPDME TM) technology. CETANERTM is a liquid, has an oxygen content of 36 wt.%, has a cetane number over 100 and is highly miscible in diesel fuel. This combination of physical and chemical properties makes CETANERTM an attractive agent for oxygenating diesel fuel. The present study considered CETANERTM ratios from 0 to 40 wt.% in a California Air Resources Board (CARB) specification diesel fuel. Particulate matter emissions, gaseous emissions and in-cylinder pressure traces were monitored over the AVL 8-Mode engine test protocol [7]. This paper presents the results from these measurements and discusses the implications of using high cetane number oxygenates in diesel fuel reformulation.

Boehman, Andre L.

2000-08-20T23:59:59.000Z

205

Obtaining the optimal fuel conserving investment mix: a linear programming hedonic technique approach  

SciTech Connect

The objectives of this study were to: (1) determine how energy efficiency affects the resale value of homes; (2) use this information concerning the implicit price of energy efficiency to estimate the resale value of fuel saving investments; and (3) incorporate these resale values into the investment decision process and determine the efficient investment mix for a household planning to own a given home for three alternative time periods. Two models were used to accomplish these objectives. A hedonic price model was used to determine the impact of energy efficiency on housing prices. The hedonic technique is a method used to attach implicit prices to characteristics that are not themselves bought and sold in markets, but are components of market goods. The hedonic model in this study provided an estimate of the implicit price paid for an increase in energy efficiency in homes on the Des-Moines housing market. In order to determine how the length of time the home is to be owned affects the optimal investment mix, a linear programming model was used to determine the cost minimizing investment mix for a baseline house under the assumption that it would be owned for 6, 20, and 50 years, alternatively. The results of the hedonic technique revealed that a premium is paid for energy efficient homes in Des Moines. The results of the linear programming model reveal that the optimal fuel saving investment mix for a home is sensitive to the time the home is to be owned.

Dinan, T.M.

1984-01-01T23:59:59.000Z

206

Fuzzy linear programming based optimal fuel scheduling incorporating blending/transloading facilities  

Science Conference Proceedings (OSTI)

In this paper the blending/transloading facilities are modeled using an interactive fuzzy linear programming (FLP), in order to allow the decision-maker to solve the problem of uncertainty of input information within the fuel scheduling optimization. An interactive decision-making process is formulated in which decision-maker can learn to recognize good solutions by considering all possibilities of fuzziness. The application of the fuzzy formulation is accompanied by a careful examination of the definition of fuzziness, appropriateness of the membership function and interpretation of results. The proposed concept provides a decision support system with integration-oriented features, whereby the decision-maker can learn to recognize the relative importance of factors in the specific domain of optimal fuel scheduling (OFS) problem. The formulation of a fuzzy linear programming problem to obtain a reasonable nonfuzzy solution under consideration of the ambiguity of parameters, represented by fuzzy numbers, is introduced. An additional advantage of the FLP formulation is its ability to deal with multi-objective problems.

Djukanovic, M.; Babic, B.; Milosevic, B. [Electrical Engineering Inst. Nikola Tesla, Belgrade (Yugoslavia); Sobajic, D.J. [EPRI, Palo Alto, CA (United States). Power System Control; Pao, Y.H. [Case Western Reserve Univ., Cleveland, OH (United States)]|[AI WARE, Inc., Cleveland, OH (United States)

1996-05-01T23:59:59.000Z

207

Compiler-based Memory Optimizations for High Performance Computing Systems.  

E-Print Network (OSTI)

??Parallelism has always been the primary method to achieve higher performance. To advance the computational capabilities of state-of-the-art high performance computing systems, we continue to (more)

Kultursay, Emre

2013-01-01T23:59:59.000Z

208

Hydrogen Fuel Cells and Storage Technology: Fundamental Research for Optimization of Hydrogen Storage and Utilization  

SciTech Connect

Design and development of improved low-cost hydrogen fuel cell catalytic materials and high-capacity hydrogenn storage media are paramount to enabling the hydrogen economy. Presently, effective and durable catalysts are mostly precious metals in pure or alloyed form and their high cost inhibits fuel cell applications. Similarly, materials that meet on-board hydrogen storage targets within total mass and volumetric constraints are yet to be found. Both hydrogen storage performance and cost-effective fuel cell designs are intimately linked to the electronic structure, morphology and cost of the chosen materials. The FCAST Project combined theoretical and experimental studies of electronic structure, chemical bonding, and hydrogen adsorption/desorption characteristics of a number of different nanomaterials and metal clusters to develop better fundamental understanding of hydrogen storage in solid state matrices. Additional experimental studies quantified the hydrogen storage properties of synthesized polyaniline(PANI)/Pd composites. Such conducting polymers are especially interesting because of their high intrinsic electron density and the ability to dope the materials with protons, anions, and metal species. Earlier work produced contradictory results: one study reported 7% to 8% hydrogen uptake while a second study reported zero hydrogen uptake. Cost and durability of fuel cell systems are crucial factors in their affordability. Limits on operating temperature, loss of catalytic reactivity and degradation of proton exchange membranes are factors that affect system durability and contribute to operational costs. More cost effective fuel cell components were sought through studies of the physical and chemical nature of catalyst performance, characterization of oxidation and reduction processes on system surfaces. Additional development effort resulted in a new hydrocarbon-based high-performance sulfonated proton exchange membrane (PEM) that can be manufactured at low cost and accompanied by improved mechanical and thermal stability.

Perret, Bob; Heske, Clemens; Nadavalath, Balakrishnan; Cornelius, Andrew; Hatchett, David; Bae, Chusung; Pang, Tao; Kim, Eunja; Hemmers, Oliver

2011-03-28T23:59:59.000Z

209

A model and optimization of alternative fuel vehicle fleet composition with triple bottom line concerns .  

E-Print Network (OSTI)

??Alternative fuel types and technologies are increasingly being advocated for transportation needs to ameliorate concerns around energy security, climate change, and fuel cost. Each fuel (more)

Zullo, Johnathon

2012-01-01T23:59:59.000Z

210

Modeling and Optimization of PEMFC Systems and its Application to Direct Hydrogen Fuel Cell Vehicles  

E-Print Network (OSTI)

Polymer Electrolyte Fuel Cell Model, J. Electrochem. Soc. ,in Polymer Electrolyte Fuel Cells, J. Electrochem. Soc. ,Solid-Polymer- Electrolyte Fuel Cell, J. Electrochem. Soc. ,

Zhao, Hengbing; Burke, Andy

2008-01-01T23:59:59.000Z

211

Visualization of Fuel Cell Water Transport and Performance Characterization under Freezing Conditions  

SciTech Connect

In this program, Rochester Institute of Technology (RIT), General Motors (GM) and Michigan Technological University (MTU) have focused on fundamental studies that address water transport, accumulation and mitigation processes in the gas diffusion layer and flow field channels of the bipolar plate. These studies have been conducted with a particular emphasis on understanding the key transport phenomena which control fuel cell operation under freezing conditions. Technical accomplishments are listed below: Demonstrated that shutdown air purge is controlled predominantly by the water carrying capacity of the purge stream and the most practical means of reducing the purge time and energy is to reduce the volume of liquid water present in the fuel cell at shutdown. The GDL thermal conductivity has been identified as an important parameter to dictate water accumulation within a GDL. Found that under the normal shutdown conditions most of the GDL-level water accumulation occurs on the anode side and that the mass transport resistance of the membrane electrode assembly (MEA) thus plays a critically important role in understanding and optimizing purge. Identified two-phase flow patterns (slug, film and mist flow) in flow field channel, established the features of each pattern, and created a flow pattern map to characterize the two-phase flow in GDL/channel combination. Implemented changes to the baseline channel surface energy and GDL materials and evaluated their performance with the ex situ multi-channel experiments. It was found that the hydrophilic channel (contact angle ? ? 10?) facilitates the removal of liquid water by capillary effects and by reducing water accumulation at the channel exit. It was also found that GDL without MPL promotes film flow and shifts the slug-to-film flow transition to lower air flow rates, compared with the case of GDL with MPL. Identified a new mechanism of water transport through GDLs based on Haines jump mechanism. The breakdown and redevelopment of the water paths in GDLs lead to an intermittent water drainage behavior, which is characterized by dynamic capillary pressure and changing of breakthrough location. MPL was found to not only limit the number of water entry locations into the GDL (thus drastically reducing water saturation), but also stabilizes the water paths (or morphology). Simultaneously visualized the water transport on cathode and anode channels of an operating fuel cell. It was found that under relatively dry hydrogen/air conditions at lower temperatures, the cathode channels display a similar flow pattern map to the ex-situ experiments under similar conditions. Liquid water on the anode side is more likely formed via condensation of water vapor which is transported through the anode GDL. Investigated the water percolation through the GDL with pseudo-Hele-Shaw experiments and simulated the capillary-driven two-phase flow inside gas diffusion media, with the pore size distributions being modeled by using Weibull distribution functions. The effect of the inclusion of the microporous layer in the fuel cell assembly was explored numerically. Developed and validated a simple, reliable computational tool for predicting liquid water transport in GDLs. Developed a new method of determining the pore size distribution in GDL using scanning electron microscope (SEM) image processing, which allows for separate characterization of GDL wetting properties and pore size distribution. Determined the effect of surface wettability and channel cross section and bend dihedral on liquid holdup in fuel cell flow channels. A major thrust of this research program has been the development of an optimal combination of materials, design features and cell operating conditions that achieve a water management strategy which facilitates fuel cell operation under freezing conditions. Based on our various findings, we have made the final recommendation relative to GDL materials, bipolar design and surface properties, and the combination of materials, design featur

Kandlikar, S.G.; Lu, Z.; Rao, N.; Sergi, J.; Rath, C.; Dade, C.; Trabold, T.; Owejan, J.; Gagliardo, J.; Allen, J.; Yassar, R.S.; Medici, E.; Herescu, A.

2010-05-30T23:59:59.000Z

212

Computer-Aided Optimization of Macroscopic Design Factors for Lithium-Ion Cell Performance and Life (Presentation)  

DOE Green Energy (OSTI)

Electric-drive vehicles enabled by power- and energy-dense batteries promise to improve vehicle efficiency and help reduce society's dependence on fossil fuels. Next generation plug-in hybrid vehicles and battery electric vehicles may also enable vehicles to be powered by electricity generated from clean, renewable resources; however, to increase the commercial viability of such vehicles, the cost, performance and life of the vehicles batteries must be further improved. This work illustrates a virtual design process to optimize the performance and life of large-format lithium ion batteries. Beginning with material-level kinetic and transport properties, the performance and life of multiple large-format cell designs are evaluated, demonstrating the impact of macroscopic design parameters such as foil thickness, tab location, and cell size and shape under various cycling conditions. Challenges for computer-aided engineering of large-format battery cells, such as competing requirements and objectives, are discussed.

Smith, K.; Kim, G. H.; Pesaran, A.

2010-04-01T23:59:59.000Z

213

Investigation of the low temperature performance of trucks operating on low cetane diesel fuel  

Science Conference Proceedings (OSTI)

An anticipated increase in diesel fuel demand prompted a study by Energy, Mines and Resources Canada, to assess the effect of synthetic and cracked fuel components on truck cold weather performance. Subsequently, a two-year contract was awarded to Esso Petroleum Canada Research to evaluate the effect of fuel composition on combustion using a 310 hp modern HD engine, and the effect on startup and driveability down to -30/sup 0/C in four Class 8 trucks.

Cartwright, S.J.; Gilbert, J.B

1988-01-01T23:59:59.000Z

214

MATERIAL AND PROCESS DEVELOPMENT LEADING TO ECONOMICAL HIGH-PERFORMANCE THIN-FILM SOLID OXIDE FUEL CELLS  

DOE Green Energy (OSTI)

This document summarizes the technical progress from April to September 2003 for the program, Material and Process Development Leading to Economical High-Performance Thin-Film Solid Oxide Fuel Cells, contract number DE-AC26-00NT40711. Characteristics of doped lanthanum gallate (LSGMF) powder suitable for thin electrolyte fabrication have been defined. Bilayers with thin LSGMF electrolyte supported on an anode were fabricated and the fabrication process was improved. Preliminary performance was characterized. High performance cathode material Sr{sub 0.5}Sm{sub 0.5}CoO{sub 3} has been down-selected and is being optimized by modifying materials characteristics and processing parameters. The selected cathode exhibited excellent performance with cathode polarization of {approx}0.23 ohm-cm{sup 2} at 600 C.

Jie Guan; Nguyen Minh

2003-10-01T23:59:59.000Z

215

Cost and Performance Comparison Of Stationary Hydrogen Fueling Appliances  

E-Print Network (OSTI)

or nitrogen from air and the purification of hydrogen from sources such as catalytic reformer off gas, coke oven gas, and ethylene plant effluent gas. Pressure swing systems are based on selective adsorbent beds of hydrogen from natural gas to fuel hydrogen FCV's. Four potential reforming systems were studied: 10

216

Core Competencies Performing topical research in plasma boundary physics, fueling  

E-Print Network (OSTI)

innovation. Experimental plasma physics Plasma theory Enabling technologies High-speed hydrogen pellet injector for fueling fusion devices Fusion Nuclear Science Facility Developing plasma heating/current drive and chamber technologies to help identify and resolve fusion reactor issues, for example, high power density

217

Optimized web services security performance with differential parsing  

Science Conference Proceedings (OSTI)

The focus of this paper is to exploit a differential technique based on the similarities among the byte sequences of the processed SOAP messages in order to improve the performance of the XML processing in the Web Service Security (WS-Security) processing. ... Keywords: XML parsing, performance, web services, web services security

Masayoshi Teraguchi; Satoshi Makino; Ken Ueno; Hyen-Vui Chung

2006-12-01T23:59:59.000Z

218

Effects of coal-derived trace species on performance of molten carbonate fuel cells. Final report  

DOE Green Energy (OSTI)

The Carbonate Fuel Cell is a very promising option for highly efficient generation of electricity from many fuels. If coal-gas is to be used, the interactions of coal-derived impurities on various fuel cell components need to be understood. Thus the effects on Carbonate Fuel Cell performance due to ten different coal-derived contaminants viz., NH{sub 3}, H{sub 2}S, HC{ell}, H{sub 2}Se, AsH{sub 3}, Zn, Pb, Cd, Sn, and Hg, have been studied at Energy Research Corporation. Both experimental and theoretical evaluations were performed, which have led to mechanistic insights and initial estimation of qualitative tolerance levels for each species individually and in combination with other species. The focus of this study was to investigate possible coal-gas contaminant effects on the anode side of the Carbonate Fuel Cell, using both out-of-cell thermogravimetric analysis by isothermal TGA, and fuel cell testing in bench-scale cells. Separate experiments detailing performance decay in these cells with high levels of ammonia contamination (1 vol %) and with trace levels of Cd, Hg, and Sn, have indicated that, on the whole, these elements do not affect carbonate fuel cell performance. However, some performance decay may result when a number of the other six species are present, singly or simultaneously, as contaminants in fuel gas. In all cases, tolerance levels have been estimated for each of the 10 species and preliminary models have been developed for six of them. At this stage the models are limited to isothermal, benchscale (300 cm{sup 2} size) single cells. The information obtained is expected to assist in the development of coal-gas cleanup systems, while the contaminant performance effects data will provide useful basic information for modeling fuel cell endurance in conjunction with integrated gasifier/fuel-cell systems (IGFC).

Not Available

1992-05-01T23:59:59.000Z

219

Effects of coal-derived trace species on performance of molten carbonate fuel cells  

DOE Green Energy (OSTI)

The Carbonate Fuel Cell is a very promising option for highly efficient generation of electricity from many fuels. If coal-gas is to be used, the interactions of coal-derived impurities on various fuel cell components need to be understood. Thus the effects on Carbonate Fuel Cell performance due to ten different coal-derived contaminants viz., NH{sub 3}, H{sub 2}S, HC{ell}, H{sub 2}Se, AsH{sub 3}, Zn, Pb, Cd, Sn, and Hg, have been studied at Energy Research Corporation. Both experimental and theoretical evaluations were performed, which have led to mechanistic insights and initial estimation of qualitative tolerance levels for each species individually and in combination with other species. The focus of this study was to investigate possible coal-gas contaminant effects on the anode side of the Carbonate Fuel Cell, using both out-of-cell thermogravimetric analysis by isothermal TGA, and fuel cell testing in bench-scale cells. Separate experiments detailing performance decay in these cells with high levels of ammonia contamination (1 vol %) and with trace levels of Cd, Hg, and Sn, have indicated that, on the whole, these elements do not affect carbonate fuel cell performance. However, some performance decay may result when a number of the other six species are present, singly or simultaneously, as contaminants in fuel gas. In all cases, tolerance levels have been estimated for each of the 10 species and preliminary models have been developed for six of them. At this stage the models are limited to isothermal, benchscale (300 cm{sup 2} size) single cells. The information obtained is expected to assist in the development of coal-gas cleanup systems, while the contaminant performance effects data will provide useful basic information for modeling fuel cell endurance in conjunction with integrated gasifier/fuel-cell systems (IGFC).

Not Available

1992-05-01T23:59:59.000Z

220

Performance of Polymer Electrolyte Membrane Fuel Cell Based on New Polymeric Ionomers  

Science Conference Proceedings (OSTI)

In this paper, novel polymer electrolyte membranes (PEMs) based on new sulfonated polyimides have been prepared. These polymers have structure of rigid aromatic polymer backbone and flexible aliphatic side chain terminated with sulfonic acid group. Membrane ... Keywords: PEM fuel cell, polymer electrolyte membrane, proton conductivity, fuel cell performance

Yan Yin; Qing Du; Kenichi Okamoto

2010-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Exploitation and Optimization of Reservoir Performance in Hunton Formation, Oklahoma  

Science Conference Proceedings (OSTI)

Hunton formation in Oklahoma has been the subject of attention for the last ten years. The new interest started with the drilling of the West Carney field in 1995 in Lincoln County. Subsequently, many other operators have expanded the search for oil and gas in Hunton formation in other parts of Oklahoma. These fields exhibit many unique production characteristics, including: (1) decreasing water-oil or water-gas ratio over time; (2) decreasing gas-oil ratio followed by an increase; (3) poor prediction capability of the reserves based on the log data; and (4) low geological connectivity but high hydrodynamic connectivity. The purpose of this investigation is to understand the principal mechanisms affecting the production, and propose methods by which we can optimize the production from fields with similar characteristics.

Mohan Kelkar

2007-06-30T23:59:59.000Z

222

Microarchitecture parameter selection to optimize system performance under process variation  

Science Conference Proceedings (OSTI)

Design variability due to within-die and die-to-die process variations has the potential to significantly reduce the maximum operating frequency and the effective yield of high-performance microprocessors in future process technology generations. This ...

Xiaoyao Liang; David Brooks

2006-11-01T23:59:59.000Z

223

Improving server application performance via pure TCP ACK receive optimization  

Science Conference Proceedings (OSTI)

Network stack performance is critical to server scalability and user-perceived application experience. Perpacket overhead is a major bottleneck in scaling network I/O. While much effort is expended on reducing perpacket overhead for data-carrying packets, ...

Michael Chan, David R. Cheriton

2013-06-01T23:59:59.000Z

224

Multidisciplinary structural design and optimization for performance, cost, and flexibility  

E-Print Network (OSTI)

Reducing cost and improving performance are two key factors in structural design. In the aerospace and automotive industries, this is particularly true with respect to design criteria such as strength, stiffness, mass, ...

Nadir, William David, 1979-

2005-01-01T23:59:59.000Z

225

A code generation approach to optimizing high-performance distributed data stream processing  

Science Conference Proceedings (OSTI)

We present a code-generation-based optimization approach to bringing performance and scalability to distributed stream processing applications. We express stream processing applications using an operator-based, stream-centric language called SPADE, which ... Keywords: profile driven optimization, streaming systems

Bu?ra Gedik; Henrique Andrade; Kun-Lung Wu

2009-11-01T23:59:59.000Z

226

Performance evaluation of an improved harmony search algorithm for numerical optimization: Melody Search (MS)  

Science Conference Proceedings (OSTI)

Melody Search (MS) Algorithm as an innovative improved version of Harmony Search optimization method, with a novel Alternative Improvisation Procedure (AIP) is presented in this paper. MS algorithm mimics performance processes of the group improvisation ... Keywords: Alternative improvisation procedure, Harmony search, Melody Search algorithm, Numerical optimization, Stochastic search methods

S. M. Ashrafi; A. B. Dariane

2013-04-01T23:59:59.000Z

227

Method to fabricate high performance tubular solid oxide fuel cells  

DOE Patents (OSTI)

In accordance with the present disclosure, a method for fabricating a solid oxide fuel cell is described. The method includes forming an asymmetric porous ceramic tube by using a phase inversion process. The method further includes forming an asymmetric porous ceramic layer on a surface of the asymmetric porous ceramic tube by using a phase inversion process. The tube is co-sintered to form a structure having a first porous layer, a second porous layer, and a dense layer positioned therebetween.

Chen, Fanglin; Yang, Chenghao; Jin, Chao

2013-06-18T23:59:59.000Z

228

Gas Turbine Combustor Performance on Synthetic Fuels, Volume 1  

Science Conference Proceedings (OSTI)

This volume presents complete data from a test program to determine the behavior of several coal-derived and shale-derived liquid fuels when burned in state-of-the-art combustion turbine engines. The methods used in analyzing the test results are described. The heat transfer effects on gas turbine combustors are discussed, as well as NOx and other emissions effects and predictions.

1980-11-01T23:59:59.000Z

229

Fuel Economy and Emissions of the Ethanol-Optimized Saab 9-5 Biopower  

Science Conference Proceedings (OSTI)

Saab Automobile recently released the BioPower engines, advertised to use increased turbocharger boost and spark advance on ethanol fuel to enhance performance. Specifications for the 2.0 liter turbocharged engine in the Saab 9-5 Biopower 2.0t report 150 hp on gasoline and a 20% increase to 180 hp on E85 (nominally 85% ethanol, 15% gasoline). While FFVs sold in the U.S. must be emissions certified on Federal Certification Gasoline as well as on E85, the European regulations only require certification on gasoline. Owing to renewed and growing interest in increased ethanol utilization in the U.S., a European-specification 2007 Saab 9-5 Biopower 2.0t was acquired by the Department of Energy and Oak Ridge National Laboratory (ORNL) for benchmark evaluations. Results show that the BioPower vehicle's gasoline equivalent fuel economy on the Federal Test Procedure (FTP) and the Highway Fuel Economy Test (HFET) are on par with similar U.S.-legal flex-fuel vehicles. Regulated and unregulated emissions measurements on the FTP and the US06 aggressive driving test (part of the supplemental FTP) show that despite the lack of any certification testing requirement in Europe on E85 or on the U.S. cycles, the BioPower is within Tier 2, Bin 5 emissions levels (note that full useful life emissions have not been measured) on the FTP, and also within the 4000 mile US06 emissions limits. Emissions of hydrocarbon-based hazardous air pollutants are higher on Federal Certification Gasoline while ethanol and aldehyde emissions are higher on ethanol fuel. The advertised power increase on E85 was confirmed through acceleration tests on the chassis dyno as well as on-road.

West, Brian H [ORNL; Lopez Vega, Alberto [ORNL; Theiss, Timothy J [ORNL; Graves, Ronald L [ORNL; Storey, John Morse [ORNL; Lewis Sr, Samuel Arthur [ORNL

2007-01-01T23:59:59.000Z

230

WaterTransport in PEM Fuel Cells: Advanced Modeling, Material Selection, Testing and Design Optimization  

Science Conference Proceedings (OSTI)

Water management in Proton Exchange Membrane, PEM, Fuel Cells is challenging because of the inherent conflicts between the requirements for efficient low and high power operation. Particularly at low powers, adequate water must be supplied to sufficiently humidify the membrane or protons will not move through it adequately and resistance losses will decrease the cell efficiency. At high power density operation, more water is produced at the cathode than is necessary for membrane hydration. This excess water must be removed effectively or it will accumulate in the Gas Diffusion Layers, GDLs, between the gas channels and catalysts, blocking diffusion paths for reactants to reach the catalysts and potentially flooding the electrode. As power density of the cells is increased, the challenges arising from water management are expected to become more difficult to overcome simply due to the increased rate of liquid water generation relative to fuel cell volume. Thus, effectively addressing water management based issues is a key challenge in successful application of PEMFC systems. In this project, CFDRC and our partners used a combination of experimental characterization, controlled experimental studies of important processes governing how water moves through the fuel cell materials, and detailed models and simulations to improve understanding of water management in operating hydrogen PEM fuel cells. The characterization studies provided key data that is used as inputs to all state-of-the-art models for commercially important GDL materials. Experimental studies and microscopic scale models of how water moves through the GDLs showed that the water follows preferential paths, not branching like a river, as it moves toward the surface of the material. Experimental studies and detailed models of water and airflow in fuel cells channels demonstrated that such models can be used as an effective design tool to reduce operating pressure drop in the channels and the associated costs and weight of blowers and pumps to force air and hydrogen gas through the fuel cell. Promising improvements to materials structure and surface treatments that can potentially aid in managing the distribution and removal of liquid water were developed; and improved steady-state and freeze-thaw performance was demonstrated for a fuel cell stack under the self-humidified operating conditions that are promising for stationary power generation with reduced operating costs.

J. Vernon Cole; Abhra Roy; Ashok Damle; Hari Dahr; Sanjiv Kumar; Kunal Jain; Ned Djilai

2012-10-02T23:59:59.000Z

231

The performance of fluidized beds, packed beds, and screens as fuel cell electrodes  

E-Print Network (OSTI)

At present, most fuel cells employ porous gas diffusion (PGD) electrodes. Although much effort has been spent on their development, the performance and cost of PGD electrodes are still major obstacles to the successful ...

Ruflin, Justin, 1981-

2006-01-01T23:59:59.000Z

232

High Performance Fuel Design for Next Generation PWRs: 11th Quarterly Report  

E-Print Network (OSTI)

I. Technical Narrative: The overall objective of this NERI project is to examine the potential for a high performance advanced fuel for Pressurized Water Reactors (PWRs), which would accommodate a substantial increase of ...

Kazimi, Mujid S.

233

High Performance Fuel Design for Next Generation PWRs 2nd Annual Report  

E-Print Network (OSTI)

The overall objective of this NERI project is to examine the potential for a high performance advanced fuel design for Pressurized Water Reactors (PWRs), which would accommodate a substantial increase of core power density ...

Ballinger, Ronald G.

234

An improved structural mechanics model for the FRAPCON nuclear fuel performance code  

E-Print Network (OSTI)

In order to provide improved predictions of Pellet Cladding Mechanical Interaction (PCMI) for the FRAPCON nuclear fuel performance code, a new model, the FRAPCON Radial-Axial Soft Pellet (FRASP) model, was developed. This ...

Mieloszyk, Alexander James

2012-01-01T23:59:59.000Z

235

Performance analysis and optimization of molecular dynamics simulation on Godson-T many-core processor  

Science Conference Proceedings (OSTI)

Molecular dynamics (MD) simulation has broad applications, but its irregular memory-access pattern makes performance optimization a challenge. This paper presents a joint application/architecture study to enhance on-chip parallelism of MD on Godson-T ...

Liu Peng; Aiichiro Nakano; Guangming Tan; Priya Vashishta; Dongrui Fan; Hao Zhang; Rajiv K. Kalia; Fenglong Song

2011-05-01T23:59:59.000Z

236

Optimization of fractured well performance of horizontal gas wells  

E-Print Network (OSTI)

In low-permeability gas reservoirs, horizontal wells have been used to increase the reservoir contact area, and hydraulic fracturing has been further extending the contact between wellbores and reservoirs. This thesis presents an approach to evaluate horizontal well performance for fractured or unfractured gas wells and a sensitivity study of gas well performance in a low permeability formation. A newly developed Distributed Volumetric Sources (DVS) method was used to calculate dimensionless productivity index for a defined source in a box-shaped domain. The unique features of the DVS method are that it can be applied to transient flow and pseudo-steady state flow with a smooth transition between the boundary conditions. In this study, I conducted well performance studies by applying the DVS method to typical tight sandstone gas wells in the US basins. The objective is to determine the best practice to produce horizontal gas wells. For fractured wells, well performance of a single fracture and multiple fractures are compared, and the effect of the number of fractures on productivity of the well is presented based on the well productivity. The results from this study show that every basin has a unique ideal set of fracture number and fracture length. Permeability plays an important role on dictating the location and the dimension of the fractures. This study indicated that in order to achieve optimum production, the lower the permeability of the formation, the higher the number of fractures.

Magalhaes, Fellipe Vieira

2007-08-01T23:59:59.000Z

237

Fuel Reliability Program: Post-Irradiation Examination and Performance Assessment of ATRIUM-10 BWR Fuel from Browns Ferry-3 Reactor  

Science Conference Proceedings (OSTI)

ATRIUM-10 design (10x10 lattice) fuel was irradiated for one 24-month period during Cycle 12 to 25 MWd/kgU rod-average exposure at Tennessee Valley Authority's Browns Ferry Unit 3 reactor. The project goal was to characterize the behavior of modern boiling water reactor (BWR) fuel at low exposures to assess early-life performance in a well-documented reactor environment. This report includes results from hot cell post-irradiation examinations. In a future Electric Power Research Institute (EPRI) report, ...

2011-06-09T23:59:59.000Z

238

Greek research reactor performance characteristics after addition of beryllium reflector and LEU fuel  

SciTech Connect

The GRR-1 is a 5-MW pool-type, light-water-moderated and-cooled reactor fueled with MTR-type fuel elements. Recently received Be reflector blocks will soon be added to the core to add additional reactivity until fresh LEU fuel arrives. REBUS-3 xy fuel cycle analyses, using burnup dependent cross sections, were performed to assist in fuel management decisions for the water- and Be-reflected HEU nonequilibrium cores. Cross sections generated by EPRI-CELL have been benchmarked to identical VIM Monte Carlo models. The size of the Be-reflected LEU core has been reduced to 30 elements compared to 35 for the HEU water-reflected core, and an equilibrium cycle calculation has been performed.

Deen, J.R.; Snelgrove, J.L. (Argonne National Lab., IL (United States)); Papastergiou, C. (National Center for Scientific Research, Athens (Greece))

1992-01-01T23:59:59.000Z

239

Greek research reactor performance characteristics after addition of beryllium reflector and LEU fuel  

SciTech Connect

The GRR-1 is a 5-MW pool-type, light-water-moderated and-cooled reactor fueled with MTR-type fuel elements. Recently received Be reflector blocks will soon be added to the core to add additional reactivity until fresh LEU fuel arrives. REBUS-3 xy fuel cycle analyses, using burnup dependent cross sections, were performed to assist in fuel management decisions for the water- and Be-reflected HEU nonequilibrium cores. Cross sections generated by EPRI-CELL have been benchmarked to identical VIM Monte Carlo models. The size of the Be-reflected LEU core has been reduced to 30 elements compared to 35 for the HEU water-reflected core, and an equilibrium cycle calculation has been performed.

Deen, J.R.; Snelgrove, J.L. [Argonne National Lab., IL (United States); Papastergiou, C. [National Center for Scientific Research, Athens (Greece)

1992-12-31T23:59:59.000Z

240

Materials accounting in a fast-breeder-reactor fuels-reprocessing facility: optimal allocation of measurement uncertainties  

Science Conference Proceedings (OSTI)

This report describes the conceptual design of a materials accounting system for the feed preparation and chemical separations processes of a fast breeder reactor spent-fuel reprocessing facility. For the proposed accounting system, optimization techniques are used to calculate instrument measurement uncertainties that meet four different accounting performance goals while minimizing the total development cost of instrument systems. We identify instruments that require development to meet performance goals and measurement uncertainty components that dominate the materials balance variance. Materials accounting in the feed preparation process is complicated by large in-process inventories and spent-fuel assembly inputs that are difficult to measure. To meet 8 kg of plutonium abrupt and 40 kg of plutonium protracted loss-detection goals, materials accounting in the chemical separations process requires: process tank volume and concentration measurements having a precision less than or equal to 1%; accountability and plutonium sample tank volume measurements having a precision less than or equal to 0.3%, a shortterm correlated error less than or equal to 0.04%, and a long-term correlated error less than or equal to 0.04%; and accountability and plutonium sample tank concentration measurements having a precision less than or equal to 0.4%, a short-term correlated error less than or equal to 0.1%, and a long-term correlated error less than or equal to 0.05%. The effects of process design on materials accounting are identified. Major areas of concern include the voloxidizer, the continuous dissolver, and the accountability tank.

Dayem, H.A.; Ostenak, C.A.; Gutmacher, R.G.; Kern, E.A.; Markin, J.T.; Martinez, D.P.; Thomas, C.C. Jr.

1982-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Integrated Radiation Transport and Nuclear Fuel Performance for Assembly-Level Simulations  

SciTech Connect

The Advanced Multi-Physics (AMP) Nuclear Fuel Performance code (AMPFuel) is focused on predicting the temperature and strain within a nuclear fuel assembly to evaluate the performance and safety of existing and advanced nuclear fuel bundles within existing and advanced nuclear reactors. AMPFuel was extended to include an integrated nuclear fuel assembly capability for (one-way) coupled radiation transport and nuclear fuel assembly thermo-mechanics. This capability is the initial step toward incorporating an improved predictive nuclear fuel assembly modeling capability to accurately account for source-terms and boundary conditions of traditional (single-pin) nuclear fuel performance simulation, such as the neutron flux distribution, coolant conditions, and assembly mechanical stresses. A novel scheme is introduced for transferring the power distribution from the Scale/Denovo (Denovo) radiation transport code (structured, Cartesian mesh with smeared materials within each cell) to AMPFuel (unstructured, hexagonal mesh with a single material within each cell), allowing the use of a relatively coarse spatial mesh (10 million elements) for the radiation transport and a fine spatial mesh (3.3 billion elements) for thermo-mechanics with very little loss of accuracy. In addition, a new nuclear fuel-specific preconditioner was developed to account for the high aspect ratio of each fuel pin (12 feet axially, but 1 4 inches in diameter) with many individual fuel regions (pellets). With this novel capability, AMPFuel was used to model an entire 17 17 pressurized water reactor fuel assembly with many of the features resolved in three dimensions (for thermo-mechanics and/or neutronics), including the fuel, gap, and cladding of each of the 264 fuel pins; the 25 guide tubes; the top and bottom structural regions; and the upper and lower (neutron) reflector regions. The final, full assembly calculation was executed on Jaguar using 40,000 cores in under 10 hours to model over 162 billion degrees of freedom for 10 loading steps. The single radiation transport calculation required about 50% of the time required to solve the thermo-mechanics with a single loading step, which demonstrates that it is feasible to incorporate, in a single code, a high-fidelity radiation transport capability with a high-fidelity nuclear fuel thermo-mechanics capability and anticipate acceptable computational requirements. The results of the full assembly simulation clearly show the axial, radial, and azimuthal variation of the neutron flux, power, temperature, and deformation of the assembly, highlighting behavior that is neglected in traditional axisymmetric fuel performance codes that do not account for assembly features, such as guide tubes and control rods.

Clarno, Kevin T [ORNL; Hamilton, Steven P [ORNL; Philip, Bobby [ORNL; Berrill, Mark A [ORNL; Sampath, Rahul S [ORNL; Allu, Srikanth [ORNL; Pugmire, Dave [ORNL; Dilts, Gary [Los Alamos National Laboratory (LANL); Banfield, James E [ORNL

2012-02-01T23:59:59.000Z

242

MATERIAL AND PROCESS DEVELOPMENT LEADING TO ECONOMICAL HIGH-PERFORMANCE THIN-FILM SOLID OXIDE FUEL CELLS  

DOE Green Energy (OSTI)

This document summarizes the technical progress from September 2002 to March 2003 for the program, Material and Process Development Leading to Economical High-Performance Thin-Film Solid Oxide Fuel Cells, contract number DE-AC26-00NT40711. The causes have been identified for the unstable open circuit voltage (OCV) and low performance exhibited by the anode-supported lanthanum gallate based cells from the earlier development. Promising results have been obtained in the area of synthesis of electrolyte and cathode powders, which showed excellent sintering and densification at low temperatures. The fabrication of cells using tapecalendering process for anode-supported thin lanthanum gallate electrolyte cells and their performance optimization is in progress.

Jie Guan; Atul Verma; Nguyen Minh

2003-04-01T23:59:59.000Z

243

Potential opportunities for nano materials to help enable enhanced nuclear fuel performance  

Science Conference Proceedings (OSTI)

This presentation is an overview of the technical challenges for development of nuclear fuels with enhanced performance and accident tolerance. Key specific aspects of improved fuel performance are noted. Examples of existing nanonuclear projects and concepts are presented and areas of potential focus are suggested. The audience for this presentation includes representatives from: DOE-NE, other national laboratories, industry and academia. This audience is a mixture of nanotechnology experts and nuclear energy researchers and managers.

McClellan, Kenneth J. [Los Alamos National Laboratory

2012-06-06T23:59:59.000Z

244

Optimizing drilling performance using a selected drilling fluid  

DOE Patents (OSTI)

To improve drilling performance, a drilling fluid is selected based on one or more criteria and to have at least one target characteristic. Drilling equipment is used to drill a wellbore, and the selected drilling fluid is provided into the wellbore during drilling with the drilling equipment. The at least one target characteristic of the drilling fluid includes an ability of the drilling fluid to penetrate into formation cuttings during drilling to weaken the formation cuttings.

Judzis, Arnis (Salt Lake City, UT); Black, Alan D. (Coral Springs, FL); Green, Sidney J. (Salt Lake City, UT); Robertson, Homer A. (West Jordan, UT); Bland, Ronald G. (Houston, TX); Curry, David Alexander (The Woodlands, TX); Ledgerwood, III, Leroy W. (Cypress, TX)

2011-04-19T23:59:59.000Z

245

Performance improvement of a PEMFC using fuels with CO by addition of oxygen-evolving compounds  

Science Conference Proceedings (OSTI)

A new method is described to improve the performance of a proton exchange membrane fuel cell (PEMFC) using reformed methanol or H{sub 2}/CO as fuels. The addition of liquid hydrogen peroxide to the humidification water for the fuel gas leads to a heterogeneous decomposition of H{sub 2}O{sub 2} and formation of active oxygen. In this way adsorbed CO is oxidized nonelectrochemically to CO{sub 2} and the blocking of the hydrogen oxidation reaction at the anode can be avoided. It is demonstrated that a complete recovery of the CO-free performance is achieved for H{sub 2}/100 ppm CO.

Schmidt, V.M.; Oetjen, H.F.; Divisek, J. [Forschungszentrum Juelich (Germany). Inst. fuer Energieverfahrenstechnik

1997-09-01T23:59:59.000Z

246

U.S. Department of Energy-Funded Performance Validation of Fuel Cell Material Handling Equipment (Presentation)  

DOE Green Energy (OSTI)

This webinar presentation to the UK Hydrogen and Fuel Cell Association summarizes how the U.S. Department of Energy is enabling early fuel cell markets; describes objectives of the National Fuel Cell Technology Evaluation Center; and presents performance status of fuel cell material handling equipment.

Kurtz, J.; Sprik, S.; Ramsden, T.; Saur, G.; Ainscough, C.; Post, M.; Peters, M.

2013-11-01T23:59:59.000Z

247

Optimization of the LCLS X-ray FEL output performance in the presence of strong undulator wakefields  

E-Print Network (OSTI)

Optimization of the LCLS X-ray FEL output performance in the presence of strong undulator wakefields

Reiche, S; Emma, P; Fawley, W M; Huang, Z; Nuhn, H D; Stupakov, G V

2005-01-01T23:59:59.000Z

248

Implementing Distribution Performance Optimization Functions That Integrate with Advanced Metering  

Science Conference Proceedings (OSTI)

This report presents the results of a study of how the data and networks of advanced metering infrastructure (AMI) might be used to benefit Volt/Volt-ampere-reactive (VAR) control. It includes a detailed overview of integrated Volt/VAR control and an in-depth assessment of how the use of AMI might be able to assist in the performance of the common tasks required. Sample case studies are provided, showing practical examples of systems currently implemented. Providers of Volt/VAR control systems were invit...

2010-12-31T23:59:59.000Z

249

Formulation and evaluation of highway transportation fuels from shale and coal oils: project identification and evaluation of optimized alternative fuels. Second annual report, March 20, 1980-March 19, 1981. [Broadcut fuel mixtures of petroleum, shale, and coal products  

DOE Green Energy (OSTI)

Project work is reported for the formulation and testing of diesel and broadcut fuels containing components from petroleum, shale oil, and coal liquids. Formulation of most of the fuels was based on refinery modeling studies in the first year of the project. Product blends were prepared with a variety of compositions for use in this project and to distribute to other, similar research programs. Engine testing was conducted in a single-cylinder CLR engine over a range of loads and speeds. Relative performance and emissions were determined in comparison with typical petroleum diesel fuel. With the eight diesel fuels tested, it was found that well refined shale oil products show only minor differences in engine performance and emissions which are related to differences in boiling range. A less refined coal distillate can be used at low concentrations with normal engine performance and increased emissions of particulates and hydrocarbons. Higher concentrations of coal distillate degrade both performance and emissions. Broadcut fuels were tested in the same engine with variable results. All fuels showed increased fuel consumption and hydrocarbon emissions. The increase was greater with higher naphtha content or lower cetane number of the blends. Particulates and nitrogen oxides were high for blends with high 90% distillation temperatures. Operation may have been improved by modifying fuel injection. Cetane and distillation specifications may be advisable for future blends. Additional multi-cylinder and durability testing is planned using diesel fuels and broadcut fuels. Nine gasolines are scheduled for testing in the next phase of the project.

Sefer, N.R.; Russell, J.A.

1981-12-01T23:59:59.000Z

250

Development of Alternative and Durable High Performance Cathode Supports for PEM Fuel Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

Alternative and Durable High Alternative and Durable High Performance Cathode Supports for PEM Fuel Cells Development of Alternative and Durable High Development of Alternative and Durable High Performance Cathode Supports for PEM Fuel Cells Performance Cathode Supports for PEM Fuel Cells PNNL: Yong Wang Conrad Zhang Vilayanur Viswanath Yuehe Lin Jun Liu Project kick Project kick - - off meeting off meeting Feb 13 Feb 13 - - 14, 2007 14, 2007 Ballard Power Systems: Stephen Campbell University of Delaware: Jingguang Chen ORNL: Sheng Dai 2 Technical Issues and Objective Technical Issues and Objective Current technical issues z Carbon support „ Susceptible to oxidation under fuel cell operating conditions. „ Oxidation further catalyzed by Pt „ Corrosion leads to Pt migration and agglomeration

251

Materials and Modules for Low Cost, High Performance Fuel Cell Humidifiers  

NLE Websites -- All DOE Office Websites (Extended Search)

Kick-off Meeting, Kick-off Meeting, Wash. D.C - 10/01/2009 Materials and Modules for Low Cost, High Performance Fuel Cell Humidifiers Prime Contractor: W. L. Gore & Associates Elkton, MD Principal Investigator: William B. Johnson Sub-Contractor: dPoint Technologies Vancouver, BC W. L. Gore & Associates, Inc. DOE Kick-off Meeting, Wash. D.C - 10/01/2009 Ahluwalia, et. al, ibid. Mirza, Z. DOE Hydrogen Program Review, June 9-13, 2008; Washington, DC Background W. L. Gore & Associates, Inc. DOE Kick-off Meeting, Wash. D.C - 10/01/2009 Objective and Technical Barriers Addressed More efficient, low-cost humidifiers can increase fuel cell inlet humidity: Reduce system cost and size of balance of plant; Improve fuel cell performance; Improve fuel cell durability. OBJECTIVE: Demonstrate a durable, high performance water

252

Development and Irradiation Performance of U-Mo Monolithic Fuel ...  

Science Conference Proceedings (OSTI)

... that will enable the conversion of research and test reactors from high enriched uranium (HEU) to low enriched uranium (LEU) without loss of performance.

253

New approaches to improve the performance of the PEM based fuel cell power systems  

E-Print Network (OSTI)

Fuel cells are expected to play an important role in future power generation. However, significant technical challenges remain and the commercial breakthrough of fuel cells is hindered by the high price of fuel cell components. As is well known, the fuel cells do not provide the robust source characteristics required to effectively follow the load during significant load steps and they have limited overload-handling capability. Further, the performance of the fuel cell is significantly degraded when the CO (Carbon Monoxide) is contained in the hydrogen fuel. In this thesis several new approaches to improve the performance of PEM based fuel cell power systems are discussed. In the first section an impedance model of the Proton Exchange Membrane Fuel Cell Stack (PEMFCS) is first proposed. This equivalent circuit model of the fuel cell stack is derived by a frequency response analysis (FRA) technique to evaluate the effects of the ripple current generated by the power-conditioning unit. Experimental results are presented to show the effects of the ripple currents. In the second section, a fuel cell powered UPS (Uninterruptible Power Supply) system is proposed. In this approach, two PEM Fuel Cell modules along with suitable DC/DC and DC/AC power electronic converter modules are employed. A Supercapacitor module is also employed to compensate for instantaneous power fluctuations including overload and to overcome the slow dynamics of the fuel processor such as reformers. A complete design example for a 1-kVA system is presented. In the third section, an advanced power converter topology is proposed to significantly improve the CO tolerance on PEM based fuel cell power systems. An additional two-stage dc-dc converter with a supercapacitor module is connected to the fuel cell to draw a low frequency (0.5Hz) pulsating current of the specific amplitude (20-30[A]) from the fuel cell stack. CO on the catalyst surface can be electro-oxidized by using this technique, and thereby the CO tolerance of the system can be significantly improved. Simulation and experimental results show the validity and feasibility of the proposed scheme.

Choi, Woojin

2004-08-01T23:59:59.000Z

254

Optimization and Demonstration of a Solid Oxide Regenerative Fuel Cell System  

Science Conference Proceedings (OSTI)

Single cell solid oxide regenerative fuel cells (SORFCs) have been demonstrated for over 1000 hours of operation at degradation rates as low as 0.5% per thousand hours for current densities as high as 300mA/cm{sup 2}. Efficiency levels (fuel cell power out vs. electrolysis power in) have been demonstrated in excess of 80% at 100mA/cm{sup 2}. All testing has been performed with metallic based interconnects and non-noble metal electrodes in order to limit fabrication costs for commercial considerations. The SORFC cell technology will be scaled up to a 1kW sized stack which will be demonstrated in Year 2 of the program. A self contained SORFC system requires efficient thermal management in order to maintain operating temperatures during exothermic and endothermic operational modes. The use of LiF as a phase change material (PCM) was selected as the optimum thermal storage medium by virtue of its superior thermal energy density by volume. Thermal storage experiments were performed using LiF and a simulated SORFC stack. The thermal storage concept was deemed to be technically viable for larger well insulated systems, although it would not enable a high efficiency thermally self-sufficient SORFC system at the 1 kW level.

James F. McElroy; Darren B. Hickey; Fred Mitlitsky

2006-09-30T23:59:59.000Z

255

Performance Optimization of an Irreversible Heat Pump with Variable-temperature Heat Reservoirs  

E-Print Network (OSTI)

An irreversible cycle model of a heat pump operating between two variable-temperature heat reservoirs is established and used to analyze the performance of the heat pump affected by heat resistances, heat leakage and internal dissipation of the working substance. The coefficient of performance of the heat pump is optimized for a given heating load. The characteristic curves of the coefficient of performance versus power input are generated. The influence of intake temperatures of heat reservoirs, thermal capacity of heat reservoirs, efficiency of heat exchangers, heat leak and internal irreversibilities on the performance of the system is discussed. The optimal ratio of the times spent on two processes of heat transfer to and from the working substance is determined. Some new results which are conducive to the optimal design and operation of real heat pump systems are obtained.

Huang, Y.; Sun, D.

2006-01-01T23:59:59.000Z

256

Faade apertures optimization: integrating cross-ventilation performance analysis in fluid dynamics simulation  

Science Conference Proceedings (OSTI)

Performance-oriented design has as a primary aim to introduce spaces that achieve acceptable levels of human comfort. Wind-induced airflow plays a significant role in the improving occupants' comfort in a building. This paper explores the extent to which ... Keywords: building performance simulation, generative design, multiple criteria optimization, parametric design, wind-induced ventilation

Chrysanthi (Sandy) Karagkouni; Ava Fatah gen Schieck; Martha Tsigkari; Angelos Chronis

2013-04-01T23:59:59.000Z

257

Performance driven design and simulation interfaces: a multi-objective parametric optimization process  

Science Conference Proceedings (OSTI)

Despite the continuous development and integration of simulation interfacing tools in current architectural research, the availability and operability of off-the-shelf tools has still not met the timeframes and performance requirements of current architectural ... Keywords: environmentally driven faade, integrated design strategy, multi-objective optimization, parametric modeling, performance driven design, simulation interfacing tool

Angelos Chronis; Martha Tsigkari; Evangelos Giouvanos; Francis Aish; Anis Abou Zaki

2012-03-01T23:59:59.000Z

258

Diesel fuel component contribution to engine emissions and performance. Final report  

DOE Green Energy (OSTI)

Contemporary diesel fuel is a blend of several refinery streams chosen to meet specifications. The need to increase yield of transportation fuel from crude oil has resulted in converting increased proportions of residual oil to lighter products. This conversion is accomplished by thermal, catalytic, and hydrocracking of high molecular weight materials rich in aromatic compounds. The current efforts to reformulate California diesel fuel for reduced emissions from existing engines is an example of another driving force affecting refining practice: regulations designed to reduce exhaust emissions. Although derived from petroleum crude oil, reformulated diesel fuel is an alternative to current specification-grade diesel fuel, and this alternative presents opportunities and questions to be resolved by fuel and engine research. Various concerned parties have argued that regulations for fuel reformulation have not been based on an adequate data base. Despite numerous studies, much ambiguity remains about the relationship of exhaust parameters to fuel composition, particularly for diesel fuel. In an effort to gather pertinent data, the automobile industry and the oil refiners have joined forces in the Air Quality Improvement Research Program (AUTO/OIL) to address this question for gasoline. The objective of that work is to define the relationship between gasoline composition and the magnitude and composition of the exhaust emissions. The results of the AUTO/OEL program will also be used, along with other data bases, to define the EPA {open_quotes}complex model{close_quotes} for reformulated gasolines. Valuable insights have been gained for compression ignition engines in the Coordinating Research Council`s VE-1 program, but no program similar to AUTO/OIL has been started for diesel fuel reformulation. A more detailed understanding of the fuel/performance relationship is a readily apparent need.

Erwin, J.; Ryan, T.W. III; Moulton, D.S. [Southwest Research Institute, San Antonio, TX (United States)] [Southwest Research Institute, San Antonio, TX (United States)

1994-11-01T23:59:59.000Z

259

Benchmarking of the MIT High Temperature Gas-cooled Reactor TRISO-coated particle fuel performance model  

E-Print Network (OSTI)

MIT has developed a Coated Particle Fuel Performance Model to study the behavior of TRISO nuclear fuels. The code, TIMCOAT, is designed to assess the mechanical and chemical condition of populations of coated particles and ...

Stawicki, Michael A

2006-01-01T23:59:59.000Z

260

Software optimization for performance, energy, and thermal distribution: Initial case studies  

Science Conference Proceedings (OSTI)

As an initial step in our Green Software research, this paper investigates whether software optimization at the application level can help achieve higher energy efficiency and better thermal behavior. We use both direct measurements and modeling to quantify ... Keywords: system-level energy consumption, software optimization, performance-energy-thermal distribution, green software, energy efficiency, power estimator, multicore systems, regressing measurements, custom-designed suite, microbenchmarks, software tuning, scalability, parallel application

M. A. Khan; C. Hankendi; A. K. Coskun; M. C. Herbordt

2011-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Research on the Performance and Emission of a Port Fuel Injection Hydrogen Internal Combustion Engine  

Science Conference Proceedings (OSTI)

A 2.0L nature aspirate gasoline engine was modified to port fuel injection (PFI) hydrogen internal combustion engine (HICE) and a series dynamometer tests were carried out. The in-cylinder combustion process was analyzed, the performance, thermal efficiency ... Keywords: hydrogen ICE, performance, emission, combustion characteristics

Dawei Sun; Fushui Liu

2011-02-01T23:59:59.000Z

262

Research on the Performance and Emission of a Port Fuel Injection Hydrogen Internal Combustion Engine  

Science Conference Proceedings (OSTI)

A 2.0L nature aspirate gasoline engine was modified to port fuel injection (PFI) hydrogen internal combustion engine (HICE) and a series dynamometer tests were carried out. The in-cylinder combustion process was analyzed, the performance, thermal efficiency ... Keywords: hydrogen ICE, performance, emission, combustion characteristics

Dawei Sun; Fushui Liu

2010-12-01T23:59:59.000Z

263

Hybridization of multi-objective evolutionary algorithms and artificial neural networks for optimizing the performance of electrical drives  

Science Conference Proceedings (OSTI)

Performance optimization of electrical drives implies a lot of degrees of freedom in the variation of design parameters, which in turn makes the process overly complex and sometimes impossible to handle for classical analytical optimization approaches. ... Keywords: Electrical drives, Feed-forward artificial neural networks, Hybridization, Multi-objective evolutionary algorithms, Performance optimization, Surrogate fitness evaluation

Alexandru-Ciprian Zvoianu, Gerd Bramerdorfer, Edwin Lughofer, Siegfried Silber, Wolfgang Amrhein, Erich Peter Klement

2013-09-01T23:59:59.000Z

264

Investigation of the performance and water transport of a polymer electrolyte membrane (pem) fuel cell  

E-Print Network (OSTI)

Fuel cell performance was obtained as functions of the humidity at the anode and cathode sites, back pressure, flow rate, temperature, and channel depth. The fuel cell used in this work included a membrane and electrode assembly (MEA) which possessed an active area of 25, 50, and 100 cm2 with the Nafion 117 and 115 membranes. Higher flow rates of inlet gases increase the performance of a fuel cell by increasing the removal of the water vapor, and decrease the mass transportation loss at high current density. Higher flow rates, however, result in low fuel utilization. An important factor, therefore, is to find the appropriate stoichiometric flow coefficient and starting point of stoichiometric flow rate in terms of fuel cell efficiency. Higher air supply leads to have better performance at the constant stoichiometric ratio at the anode, but not much increase after the stoichiometric ratio of 5. The effects of the environmental conditions and the channel depth for an airbreathing polymer electrolyte membrane fuel cell were investigated experimentally. Triple serpentine designs for the flow fields with two different flow depths was used. The shallow flow field deign improves dramatically the performance of the air-breathing fuel cell at low relative humidity, and slightly at high relative humidity. For proton exchange membrane fuel cells, proper water management is important to obtain maximum performance. Water management includes the humidity levels of the inlet gases as well as the understanding of the water process within the fuel cell. Two important processes associated with this understanding are (1) electro-osmotic drag of water molecules, and (2) back diffusion of the water molecules. There must be a neutral water balance over time to avoid the flooding, or drying the membranes. For these reasons, therefore, an investigation of the role of water transport in a PEM fuel cell is of particular importance. In this study, through a water balance experiment, the electro-osmotic drag coefficient was quantified and studied. For the cases where the anode was fully hydrated and the cathode suffered from the drying, when the current density was increased, the electro- osmotic drag coefficient decreased.

Park, Yong Hun

2007-12-01T23:59:59.000Z

265

Performance and emissions of a catalytic reactor with propane, diesel, and Jet A fuels  

DOE Green Energy (OSTI)

As part of the ERDA-funded Gas Turbine Highway Vehicle Systems project, tests were made to determine the performance and emissions of a catalytic reactor operated with propane, No. 2 diesel, and Jet A fuels. A 12-cm diameter and 16-cm long catalytic reactor using a proprietary noble metal catalyst was operated at an inlet temperature of 800 K, a pressure of 3 x 10/sup 5/ Pa and reference velocities of 10 to 15 m/s. No significant differences between the performance of the three fuels were observed when 98.5% purity propane was used. The combustion efficiency for 99.8% purity propane tested later was significantly lower, however. The diesel fuel contained 135 ppM of bound nitrogen and consequently produced the highest NO/sub x/ emissions of the three fuels. As much as 85% of the bound nitrogen was converted to NO/sub x/. Steady-state emissions goals based on half the most stringent proposed automotive standards were met when the reactor was operated at an adiabatic combustion temperature higher than 1350 K with all fuels except the 99.8% purity propane. With that fuel, a minimum temperature of 1480 K was required.

Anderson, D.N.

1977-01-01T23:59:59.000Z

266

Configuration and performance of the indirect-fired fuel cell bottomed turbine cycle  

SciTech Connect

The natural gas, indirect-fired fuel cell bottomed turbine cycle (NG-IFFC) is introduced as a novel power plant system for the distributed power and on-site markets in the 20--200 megawatt (MW) size range. The novel indirect-fired carbonate fuel cell bottomed turbine cycle (NG-IFCFC) power plant system configures the ambient pressure carbonate fuel cell with a gas turbine, air compressor, combustor, and ceramic heat exchanger. Performance calculations from ASPEN simulations present material and energy balances with expected power output. The results indicate efficiencies and heat rates for the NG-IFCFC are comparable to conventionally bottomed carbonate fuel cell steam bottomed cycles, but with smaller and less expensive components.

Micheli, P.L.; Williams, M.C.; Parsons, E.L. Jr.

1993-12-31T23:59:59.000Z

267

Effects of coal-derived trace species on the performance of molten carbonate fuel cells  

DOE Green Energy (OSTI)

The overall objective of the present study was to determine in detail the interaction effects of 10 simultaneously present, coal-gas contaminants, both on each other and on components of the Carbonate Fuel Cell. The primary goal was to assess underlying chemistries and reaction mechanisms which may cause decay in fuel cell performance or endurance as a result of both physics-chemical and/or mechanical interactions with the cell components and internal fuel cell parts. It was found, both from theory and cell test evidence, that trace contaminant interactions may occur with: Fuel-cell Electrodes (e.g., in this study with the Ni-anode), Lithium/Potassium Carbonate Electrolyte, Nickel and SS-Hardware, and by Mechanical Obstruction of Gas Flow in the Anode Plenum.

Pigeaud, A.

1991-10-01T23:59:59.000Z

268

Integrated Radiation Transport and Nuclear Fuel Performance for Assembly-Level Simulations  

SciTech Connect

The Advanced Multi-Physics (AMP) Nuclear Fuel Performance code (AMPFuel) is focused on predicting the temperature and strain within a nuclear fuel assembly to evaluate the performance and safety of existing and advanced nuclear fuel bundles within existing and advanced nuclear reactors. AMPFuel was extended to include an integrated nuclear fuel assembly capability for (one-way) coupled radiation transport and nuclear fuel assembly thermo-mechanics. This capability is the initial step toward incorporating an improved predictive nuclear fuel assembly modeling capability to accurately account for source-terms, such as neutron flux distribution, coolant conditions and assembly mechanical stresses, of traditional (single-pin) nuclear fuel performance simulation. A novel scheme is introduced for transferring the power distribution from the Scale/Denovo (Denovo) radiation transport code (structured, Cartesian mesh with smeared materials within each cell) to AMPFuel (unstructured, hexagonal mesh with a single material within each cell), allowing the use of a relatively coarse spatial mesh (10 million elements) for the radiation transport and a fine spatial mesh (3.3 billion elements) for thermo-mechanics with very little loss of accuracy. With this novel capability, AMPFuel was used to model an entire 1717 pressurized water reactor fuel assembly with many of the features resolved in three dimensions (for thermo-mechanics and/or neutronics). A full assembly calculation was executed on Jaguar using 40,000 cores in under 10 hours to model over 160 billion degrees of freedom for 10 loading steps. The single radiation transport calculation required about 50% of the time required to solve the thermo-mechanics with a single loading step, which demonstrates that it is feasible to incorporate, in a single code, a high-fidelity radiation transport capability with a high-fidelity nuclear fuel thermo-mechanics capability and anticipate acceptable computational requirements. The results of the full assembly simulation clearly show the axial, radial, and azimuthal variation of the neutron flux, power, temperature, and deformation of the assembly, highlighting behavior that is neglected in traditional axisymmetric fuel performance codes that do not account for assembly features, such as guide tubes and control rods.

Hamilton, Steven P [ORNL; Clarno, Kevin T [ORNL; Philip, Bobby [ORNL; Berrill, Mark A [ORNL; Sampath, Rahul S [ORNL; Allu, Srikanth [ORNL

2012-01-01T23:59:59.000Z

269

Modifying Ceramic Fuel Pellets to Improve UO2 Properties  

Science Conference Proceedings (OSTI)

... UO2 fuel will provide manufacturers with tools to optimize fuel performance. ... Electronic Structure Calculations of Structure and Chemistry of the Y2O3/Fe Interface ... Impacts of Hydrogen in Unirradiated Zircaloy Nuclear Cladding under Dry...

270

Design Optimization of PHEV and EREV Powertrain Architectures - Performance and Efficiency  

Science Conference Proceedings (OSTI)

This project investigates design optimization of plug-in hybrid electric vehicle (PHEV) and extended range electric vehicle (EREV) powertrain architectures in terms of performance and efficiency. The motivation behind this initial effort is to develop a comparative method for assessing design choices for a given vehicle class that can be used to test those design choices through sensitivity analysis in later investigations.

2008-12-16T23:59:59.000Z

271

Fast algorithms for thermal constrained performance optimization in DAG scheduling on multi-core processors  

Science Conference Proceedings (OSTI)

Thermal management is highly crucial for efficient exploitation of the potentially enormous computational power offered by advanced multi-core processors. Higher temperatures can adversely affect these processors. Without any thermal constraint, a task ... Keywords: application-oriented task graphs, DAG scheduling, thermal constrained performance optimization, advanced multicore processors, PAVD, TAVD, greedy-based approach

H. F. Sheikh; I. Ahmad

2011-07-01T23:59:59.000Z

272

Software Optimization for Performance, Energy, and Thermal Distribution: Initial Case Studies  

E-Print Network (OSTI)

Software Optimization for Performance, Energy, and Thermal Distribution: Initial Case Studies Md and modeling to quantify power, energy and temperature for a given software method. The infrastructure includes two case studies. In the first one, we use software tuning for improving the scalability and energy

Coskun, Ayse

273

Optimization of performance characteristics in a class of irreversible chemical pumps  

Science Conference Proceedings (OSTI)

A new irreversible cyclic model of a class of two-source chemical pumps, which are affected by not only finite-rate mass transfer and mass leak but also the internal dissipation resulting from friction, eddy currents and other irreversible effects inside ... Keywords: Chemical pump, Irreversibility, Mass transfer, Optimal analysis, Performance characteristic

Guoxing Lin; Jincan Chen; Ekkes BrCk; Ben Hua

2006-04-01T23:59:59.000Z

274

Dynamic optimization with a new performance index for a 2-dof translational parallel manipulator  

Science Conference Proceedings (OSTI)

The dynamic analysis and optimization problem of a 2-DoF Translational Parallel Manipulator (TPM) is addressed in this paper. Based on the principle of virtual work and the concept of link Jacobian matrix, the explicit expressions of the dynamic model ... Keywords: global and comprehensive dynamic performance index (GCDPI), hardware in the loop simulation (HILS), operational space formulation, translational parallel manipulator

Gang Zhang; PinKuan Liu; Han Ding

2012-10-01T23:59:59.000Z

275

Hydrogen Fuel Cell Performance in the Key Early Markets of Material Handling Equipment and Backup Power (Presentation)  

DOE Green Energy (OSTI)

This presentation summarizes the results of NREL's analysis of hydrogen fuel cell performance in the key early markets of material handling equipment (MHE) and backup power.

Kurtz, J.; Sprik, S.; Ramsden, T.; Saur, G.; Ainscough, C.; Post, M.; Peters, M.

2013-10-01T23:59:59.000Z

276

Application of the BISON Fuel Performance Code to the FUMEX-III Coordinated Research Project  

SciTech Connect

INL recently participated in FUMEX-III, an International Atomic Energy Agency sponsored fuel modeling Coordinated Research Project. A main purpose of FUMEX-III is to compare code predictions to reliable experimental data. During the same time period, the INL initiated development of a new multidimensional (2D and 3D) multiphysics nuclear fuel performance code called BISON. Interactions with international fuel modeling researchers via FUMEX-III played a significant and important role in the BISON evolution, particularly influencing the selection of material and behavioral models which are now included in the code. BISON's ability to model integral fuel rod behavior did not mature until 2011, thus the only FUMEX-III case considered was the Riso3-GE7 experiment, which includes measurements of rod outer diameter following pellet clad mechanical interaction (PCMI) resulting from a power ramp late in fuel life. BISON comparisons to the Riso3-GE7 final rod diameter measurements are quite reasonable. The INL is very interested in participation in the next Fuel Modeling Coordinated Research Project and would like to see the project initiated as soon as possible.

R. L. Williamson; S. R. Novascone

2012-04-01T23:59:59.000Z

277

Visualization of Fuel Cell Water Transport and Performance Characterization under Freezing Conditions  

DOE Green Energy (OSTI)

\tDeveloped a new method of determining the pore size distribution in GDL using scanning electron microscope (SEM) image processing, which allows for separate characterization of GDL wetting properties and pore size distribution. \tDetermined the effect of surface wettability and channel cross section and bend dihedral on liquid holdup in fuel cell flow channels. A major thrust of this research program has been the development of an optimal combination of materials, design features and cell operating conditions that achieve a water management strategy which facilitates fuel cell operation under freezing conditions. Based on our various findings, we have made the final recommendation relative to GDL materials, bipolar design and surface properties, and the combination of materials, design featur

Kandlikar, S.G.; Lu, Z.; Rao, N.; Sergi, J.; Rath, C.; Dade, C.; Trabold, T.; Owejan, J.; Gagliardo, J.; Allen, J.; Yassar, R.S.; Medici, E.; Herescu, A.

2010-05-30T23:59:59.000Z

278

Effect of Coal Contaminants on Solid Oxide Fuel System Performance and Service Life  

DOE Green Energy (OSTI)

The U.S. Department of Energy's SECA program envisions the development of high-efficiency, low-emission, CO{sub 2} sequestration-ready, and fuel-flexible technology to produce electricity from fossil fuels. One such technology is the integrated gasification-solid oxide fuel cell (SOFC) that produces electricity from the gas stream of a coal gasifier. SOFCs have high fuel-to-electricity conversion efficiency, environmental compatibility (low NO{sub x} production), and modularity. Naturally occurring coal has many impurities and some of these impurities end in the fuel gas stream either as a vapor or in the form of fine particulate matter. Establishing the tolerance limits of SOFCs for contaminants in the coal-derived gas will allow proper design of the fuel feed system that will not catastrophically damage the SOFC or allow long-term cumulative degradation. The anodes of Ni-cermet-based SOFCs are vulnerable to degradation in the presence of contaminants that are expected to be present in a coal-derived fuel gas stream. Whereas the effects of some contaminants such as H{sub 2}S, NH{sub 3} and HCl have been studied, the effects of other contaminants such as As, P, and Hg have not been ascertained. The primary objective of this study was to determine the sensitivity of the performance of solid oxide fuel cells to trace level contaminants present in a coal-derived gas stream in the temperature range 700 to 900 C. The results were used to assess catastrophic damage risk and long-term cumulative effects of the trace contaminants on the lifetime expectancy of SOFC systems fed with coal-derived gas streams.

Gopala Krishnan; P. Jayaweera; J. Bao; J. Perez; K. H. Lau; M. Hornbostel; A. Sanjurjo; J. R. Albritton; R. P. Gupta

2008-09-30T23:59:59.000Z

279

Effect of hydrophilic treatment of microporous layer on fuel cell performance  

SciTech Connect

The gas diffusion layer in a polymer electrolyte fuel cell is the component primarily responsible for effective water management under a wide variety of conditions. The incorporation of hydrophilic alumosilicate fibers in the microporous layer leads to an improvement in the fuel cell performance associated with a decrease in the mass transport resistance especially under high RH operation. This improvement in performance is obtained without sacrificing performance under low RH conditions. The alumosilicate fibers create domains that wick liquid water away from the catalyst layer. The improved mass transport performance is corroborated by AC impedance and neutron radiography analysis and is consistent with an increase in the average pore diameter inside the microporous layer.

Mukundan, Rangachary [Los Alamos National Laboratory; Davey, John R [Los Alamos National Laboratory; Fairweather, Joseph D [Los Alamos National Laboratory; Borup, Rodney L [Los Alamos National Laboratory; Spernjak, Dusan [Los Alamos National Laboratory; Spendelow, Jacob [Los Alamos National Laboratory; Hussey, Daniel S [NIST; Jacobson, David L [NIST; Wilde, Peter [GERMANY; Schweiss, Ruediger [GERMANY

2010-01-01T23:59:59.000Z

280

Sensitivity Analysis of FEAST-Metal Fuel Performance Code: Initial Results  

SciTech Connect

This memo documents the completion of the LANL milestone, M3FT-12LA0202041, describing methodologies and initial results using FEAST-Metal. The FEAST-Metal code calculations for this work are being conducted at LANL in support of on-going activities related to sensitivity analysis of fuel performance codes. The objective is to identify important macroscopic parameters of interest to modeling and simulation of metallic fuel performance. This report summarizes our preliminary results for the sensitivity analysis using 6 calibration datasets for metallic fuel developed at ANL for EBR-II experiments. Sensitivity ranking methodology was deployed to narrow down the selected parameters for the current study. There are approximately 84 calibration parameters in the FEAST-Metal code, of which 32 were ultimately used in Phase II of this study. Preliminary results of this sensitivity analysis led to the following ranking of FEAST models for future calibration and improvements: fuel conductivity, fission gas transport/release, fuel creep, and precipitation kinetics. More validation data is needed to validate calibrated parameter distributions for future uncertainty quantification studies with FEAST-Metal. Results of this study also served to point out some code deficiencies and possible errors, and these are being investigated in order to determine root causes and to improve upon the existing code models.

Edelmann, Paul Guy [Los Alamos National Laboratory; Williams, Brian J. [Los Alamos National Laboratory; Unal, Cetin [Los Alamos National Laboratory; Yacout, Abdellatif [Argonne National Laboratories

2012-06-27T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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281

THE EFFECT OF LOW CONCENTRATIONS OF TETRACHLOROETHYLENE ON THE PERFORMANCE OF PEM FUEL CELLS  

Science Conference Proceedings (OSTI)

Polymer electrolyte membrane (PEM) fuel cells use components that are susceptible to contaminants in the fuel stream. To ensure fuel quality, standards are being set to regulate the amount of impurities allowable in fuel. The present study investigates the effect of chlorinated impurities on fuel cell systems using tetrachloroethylene (PCE) as a model compound for cleaning and degreasing agents. Concentrations between 0.05 parts per million (ppm) and 30 ppm were studied. We show how PCE causes rapid drop in cell performances for all concentrations including 0.05 ppm. At concentrations of 1 and 0.05 ppm, PCE poisoned the cell at a rate dependent on the dosage of the contaminant delivered to the cell. PCE appears to affect the cell when the cell potential was over potentials higher than approximately 0.2 V. No effects were observed at voltages around or below 0.2 V and the cells could be recovered from previous poisoning performed at higher potentials. Recoveries at those low voltages could be induced by changing the operating voltage or by purging the system. Poisoning did not appear to affect the membrane conductivity. Measurements with long-path length IR results suggested catalytic decomposition of the PCE by hydrogen over the anode catalyst.

COLON-MERCHADO, H.; MARTINEZ-RODRIGUEZ, M.; FOX, E.; RHODES, W.; MCWHORTER, C.; GREENWAY, S.

2011-04-18T23:59:59.000Z

282

Alternative Approaches to Assessing the Performance and Suitability of Yucca Mountain for Spent Fuel Disposal  

Science Conference Proceedings (OSTI)

EPRI's Total System Performance Assessment (TSPA) model has been applied to the candidate spent fuel and high level radioactive waste (HLW) disposal site at Yucca Mountain, Nevada. Building on earlier work, this report details recent modifications to EPRI's TSPA Integrated Multiple Assumptions and Release Code (IMARC), as applied to Yucca Mountain. The report includes performance analyses using IMARC as well as additional analyses and input to provide greater insight. The report also provides recommendat...

1998-12-11T23:59:59.000Z

283

Material Performance of Fully-Ceramic Micro-Encapsulated Fuel under Selected LWR Design Basis Scenarios: Final Report  

SciTech Connect

The extension to LWRs of the use of Deep-Burn coated particle fuel envisaged for HTRs has been investigated. TRISO coated fuel particles are used in Fully-Ceramic Microencapsulated (FCM) fuel within a SiC matrix rather than the graphite of HTRs. TRISO particles are well characterized for uranium-fueled HTRs. However, operating conditions of LWRs are different from those of HTRs (temperature, neutron energy spectrum, fast fluence levels, power density). Furthermore, the time scales of transient core behavior during accidents are usually much shorter and thus more severe in LWRs. The PASTA code was updated for analysis of stresses in coated particle FCM fuel. The code extensions enable the automatic use of neutronic data (burnup, fast fluence as a function of irradiation time) obtained using the DRAGON neutronics code. An input option for automatic evaluation of temperature rise during anticipated transients was also added. A new thermal model for FCM was incorporated into the code; so-were updated correlations (for pyrocarbon coating layers) suitable to estimating dimensional changes at the high fluence levels attained in LWR DB fuel. Analyses of the FCM fuel using the updated PASTA code under nominal and accident conditions show: (1) Stress levels in SiC-coatings are low for low fission gas release (FGR) fractions of several percent, as based on data of fission gas diffusion in UO{sub 2} kernels. However, the high burnup level of LWR-DB fuel implies that the FGR fraction is more likely to be in the range of 50-100%, similar to Inert Matrix Fuels (IMFs). For this range the predicted stresses and failure fractions of the SiC coating are high for the reference particle design (500 {micro}mm kernel diameter, 100 {micro}mm buffer, 35 {micro}mm IPyC, 35 {micro}mm SiC, 40 {micro}mm OPyC). A conservative case, assuming 100% FGR, 900K fuel temperature and 705 MWd/kg (77% FIMA) fuel burnup, results in a 8.0 x 10{sup -2} failure probability. For a 'best-estimate' FGR fraction of 50% and a more modest burnup target level of 500 MWd/kg ,the failure probability drops below 2.0 x 10{sup -5}, the typical performance of TRISO fuel made under the German HTR research program. An optimization study on particle design shows improved performance if the buffer size is increased from 100 to 120 {micro}mm while reducing the OPyC layer. The presence of the latter layer does not provide much benefit at high burnup levels (and fast fluence levels). Normally the shrinkage of the OPyC would result in a beneficial compressive force on the SiC coating. However, at high fluence levels the shrinkage is expected to turn into swelling, resulting in the opposite effect. However, this situation is different when the SiC-matrix, in which the particles are embedded, is also considered: the OPyC swelling can result in a beneficial compressive force on the SiC coating since outward displacement of the OPyC outer surface is inhibited by the presence of the also-swelling SiC matrix. Taking some credit for this effect by adopting a 5 {micro}mm SiC-matrix layer, the optimized particle (100 {micro}mm buffer and 10 {micro}mm OPyC), gives a failure probability of 1.9 x 10{sup -4} for conservative conditions. During a LOCA transient, assuming core re-flood in 30 seconds, the temperature of the coated particle can be expected to be about 200K higher than nominal temperature (900K). For this event the particle failure fraction for a conservative case is 1.0 x 10{sup -2}, for the optimized particle design. For a FGR-fraction of 50% this value reduces to 6.4 x 10{sup -4}.

B. Boer; R. S. Sen; M. A. Pope; A. M. Ougouag

2011-09-01T23:59:59.000Z

284

NERSC and HDF Group Optimize HDF5 Library to Improve I/O Performance  

NLE Websites -- All DOE Office Websites (Extended Search)

and HDF Group and HDF Group Optimize HDF5 Library to Improve I/O Performance NERSC and HDF Group Optimize HDF5 Library to Improve I/O Performance June 28, 2010 A common complaint among air travelers on short trips is that the time it takes to get in and out of the airplane and airports can be as long as the flight itself. In computer terms, that's a classic input/output (I/O) problem. Supercomputer users sometimes face a similar problem: the computer tears through the calculations with amazing speed, but the time it takes to write the resulting data to disk ends up slowing down the whole job. There are several layers of software that deal with I/O on high performance computing (HPC) systems. The filesystem software, such as Lustre or GPFS, is closest to the hardware and deals with the physical access and storage

285

Optimizing performance of superscalar codes for a single Cray X1MSP processor  

Science Conference Proceedings (OSTI)

The growing gap between sustained and peak performance for full-scale complex scientific applications on conventional supercomputers is a major concern in high performance computing. The recently-released vector-based Cray X1 offers to bridge this gap for many demanding scientific applications. However, this unique architecture contains both data caches and multi-streaming processing units, and the optimal programming methodology is still under investigation. In this paper we investigate Cray X1 code optimization for a suite of computational kernels originally designed for superscalar processors. For our study, we select four applications from the SPLASH2 application suite (1-D FFT,Radix, Ocean, and Nbody), two kernels from the NAS benchmark suite (3-DFFT and CG), and a matrix-matrix multiplication kernel. Results show that for many cases, the addition of vectorization compiler directives results faster runtimes. However, to achieve a significant performance improvement via increased vector length, it is often necessary to restructure the program at the source level sometimes leading to algorithmic level transformations. Additionally, memory bank conflicts may result in substantial performance losses. These conflicts can often be exacerbated when optimizing code for increased vector lengths, and must be explicitly minimized. Finally, we investigate the relationship of the X1 data caches on overall performance.

Shan, Hongzhang; Strohmaier, Erich; Oliker, Leonid

2004-06-08T23:59:59.000Z

286

Performance of Transuranic-Loaded Fully Ceramic Micro-Encapsulated Fuel in LWRs Final Report, Including Void Reactivity Evaluation  

SciTech Connect

The current focus of the Deep Burn Project is on once-through burning of transuranics (TRU) in light-water reactors (LWRs). The fuel form is called Fully-Ceramic Micro-encapsulated (FCM) fuel, a concept that borrows the tri-isotropic (TRISO) fuel particle design from high-temperature reactor technology. In the Deep Burn LWR (DB-LWR) concept, these fuel particles are pressed into compacts using SiC matrix material and loaded into fuel pins for use in conventional LWRs. The TRU loading comes from the spent fuel of a conventional LWR after 5 years of cooling. Unit cell and assembly calculations have been performed using the DRAGON-4 code to assess the physics attributes of TRU-only FCM fuel in an LWR lattice. Depletion calculations assuming an infinite lattice condition were performed with calculations of various reactivity coefficients performed at each step. Unit cells and assemblies containing typical UO2 and mixed oxide (MOX) fuel were analyzed in the same way to provide a baseline against which to compare the TRU-only FCM fuel. Then, assembly calculations were performed evaluating the performance of heterogeneous arrangements of TRU-only FCM fuel pins along with UO2 pins.

Michael A. Pope; R. Sonat Sen; Brian Boer; Abderrafi M. Ougouag; Gilles Youinou

2011-09-01T23:59:59.000Z

287

Collective Framework and Performance Optimizations to Open MPI for Cray XT Platforms  

Science Conference Proceedings (OSTI)

The performance and scalability of collective operations plays a key role in the performance and scalability of many scientific applications. Within the Open MPI code base we have developed a general purpose hierarchical collective operations framework called Cheetah, and applied it at large scale on the Oak Ridge Leadership Computing Facility's Jaguar (OLCF) platform, obtaining better performance and scalability than the native MPI implementation. This paper discuss Cheetah's design and implementation, and optimizations to the framework for Cray XT 5 platforms. Our results show that the Cheetah's Broadcast and Barrier perform better than the native MPI implementation. For medium data, the Cheetah's Broadcast outperforms the native MPI implementation by 93% for 49,152 processes problem size. For small and large data, it out performs the native MPI implementation by 10% and 9%, respectively, at 24,576 processes problem size. The Cheetah's Barrier performs 10% better than the native MPI implementation for 12,288 processes problem size.

Ladd, Joshua S [ORNL; Gorentla Venkata, Manjunath [ORNL; Shamis, Pavel [ORNL; Graham, Richard L [ORNL

2011-01-01T23:59:59.000Z

288

In Situ CO, Oxygen, and Opacity Measurement for Optimizing Combustion Control System Performance  

E-Print Network (OSTI)

The performance of a combustion control system is limited by the accuracy and reliability of the feedback provided by the stack emission flue gas monitoring system which is utilized to analyze the composition of the products of combustion. A detailed review of the latest state-of-the-art In Situ measurement techniques is provided, including: gas filter correlation spectroscopy (CO), zirconium oxide fuel cell (oxygen), and glass fiber optics based transmissometers (opacity). Recent advancements in the design and application of microprocessor-based In Situ CO, oxygen, and opacity stack emission monitoring systems are outlined, including a review of the performance capability of the latest microprocessor-based combust ion control systems.

Molloy, R. C.

1982-01-01T23:59:59.000Z

289

Concrete Shield Performance of the VSC-17 Spent Nuclear Fuel Cask  

Science Conference Proceedings (OSTI)

In 2003, representatives from the Central Research Institute of Electric Power Industry (CRIEPI) requested development of a project with the objective of determining the performance of a concrete spent nuclear fuel storage cask. Radiation and environmental effects may cause chemical alteration of the concrete that could result in excessive cracking, spalling, and loss of compressive strength. The Idaho National Laboratory (INL) project team and CRIEPI representatives identified the Ventilated Storage Cask (VSC-17) spent nuclear fuel storage cask as a candidate to study cask performance, because it had been used to store fuel as part of a dry cask storage demonstration project for more than 15 years. The project involved investigating the properties of the concrete shield. INL performed a survey of the cask in the summers of 2003 and 2004. Preliminary cask evaluations performed in 2003 indicated that the cask has no visual degradation. However, a 4-5 mrem/hr step-change in the radiation levels about halfway up the cask and a localized hot spot beneath an upper air vent indicate that there may be variability in the density of the concrete or localized cracking. In 2005, INL and CRIEPI scientists performed additional surveys on the VSC-17 cask. This document summarizes the methods used on the VSC-17 to evaluate the cask for compressive strength, concrete cracking, concrete thickness, and temperature distribution.

Sheryl L. Morton; Philip L. Winston; Toshiari Saegusa; Koji Shirai; Akihiro Sasahara; Takatoshi Hattori

2006-04-01T23:59:59.000Z

290

Prediction of performance and exhaust emissions of a diesel engine fueled with biodiesel produced from waste frying palm oil  

Science Conference Proceedings (OSTI)

Biodiesel is receiving increasing attention each passing day because of its fuel properties and compatibility with the petroleum-based diesel fuel (PBDF). Therefore, in this study, the prediction of the engine performance and exhaust emissions is carried ... Keywords: ANN, Biodiesel, Diesel engine, Emissions, Engine performance

Mustafa Canakci; Ahmet Necati Ozsezen; Erol Arcaklioglu; Ahmet Erdil

2009-07-01T23:59:59.000Z

291

Guidelines for Upgrading Electrostatic Precipitator Performance: Volume 1: Optimizing an Existing Electrostatic Precipitator  

Science Conference Proceedings (OSTI)

The first of a two-volume set, this guide presents a systematic procedure to optimize a chronically under-performing electrostatic precipitator (ESP) without conducting a major upgrade. The guide focuses on ESPs that require only moderate improvements (less than $10-$20/kW) to achieve their emissions goals. The second volume of this report, which will appear at the end of 1999, will cover more extensive upgrades, as well as flue gas conditioning.

1999-09-28T23:59:59.000Z

292

Optimization of efficiency and energy density of passive micro fuel cells and galvanic hydrogen generators  

E-Print Network (OSTI)

A PEM micro fuel cell system is described which is based on self-breathing PEM micro fuel cells in the power range between 1 mW and 1W. Hydrogen is supplied with on-demand hydrogen production with help of a galvanic cell, that produces hydrogen when Zn reacts with water. The system can be used as a battery replacement for low power applications and has the potential to improve the run time of autonomous systems. The efficiency has been investigated as function of fuel cell construction and tested for several load profiles.

Hahn, Robert; Krumbholz, Steffen; Reichl, Herbert

2008-01-01T23:59:59.000Z

293

Performance Characterization of a Medium-Duty Diesel Engine with Bio-Diesel and Petroleum Diesel Fuels  

E-Print Network (OSTI)

In the wake of global warming and fossil fuel depletion, renewed attention has been paid to shifting away from the use of petroleum based fuels. The world?s energy demand is commencing its dependency on alternative fuels. Such alternative fuels in use today consist of bio-alcohols (such as ethanol), hydrogen, biomass, and natural oil/fat derived fuels. However, in this study, the focus will be on the alternative fuel derived from natural oils and fats, namely biodiesel. The following study characterizes the performance of a medium-duty diesel engine fuelled with biodiesel and conventional diesel. The objective is accomplished by taking measurements of manifold pressure and temperature, fuel flow, air flow, and torque. The study first characterizes a John Deere 4.5 liter 4 cylinder direct injection engine with exhaust gas recirculation (EGR), common rail fuel injection, and variable turbo-charging with conventional petroleum diesel to set a reference for comparison. The study then proceeds to characterize the differences in engine performance as a result of using biodiesel relative to conventional diesel. The results show that torque decreases with the use of biodiesel by about 10%. The evaluation of engine performance parameters shows that torque is decreased because of the lower heating value of biodiesel compared to conventional diesel. The insignificant difference between the other performance parameters shows that the ECM demands the same performance of the engine regardless of the fuel being combusted by the engine.

Esquivel, Jason

2008-12-01T23:59:59.000Z

294

Joint optimization of location and inventory decisions for improving supply chain cost performance  

E-Print Network (OSTI)

This dissertation is focused on investigating the integration of inventory and facility location decisions in different supply chain settings. Facility location and inventory decisions are interdependent due to the economies of scale that are inherent in transportation and replenishment costs. The facility location decisions have an impact on the transportation and replenishment costs which, in turn, affect the optimal inventory policy. On the other hand, the inventory policy dictates the frequency of shipments to replenish inventory which, in turn, affects the number of deliveries, and, hence, the transportation costs, between the facilities. Therefore, our main research objectives are to: compare the optimal facility location, determined by minimizing total transportation costs, to the one determined by the models that also consider the timing and quantity of inventory replenishments and corresponding costs, investigate the effect of facility location decisions on optimal inventory decisions, and measure the impact of integrated decision-making on overall supply chain cost performance. Placing a special emphasis on the explicit modeling of transportation costs, we develop several novel models in mixed integer linear and nonlinear optimization programming. Based on how the underlying facility location problem is modeled, these models fall into two main groups: 1) continuous facility location problems, and 2) discrete facility location problems. For the stylistic models, the focus is on the development of analytical solutions. For the more general models, the focus is on the development of efficient algorithms. Our results demonstrate the impact of explicit transportation costs on integrated decisions, the impact of different transportation cost functions on integrated decisions in the context of continuous facility location problems of interest, the value of integrated decision-making in different supply chain settings, and the performance of solution methods that jointly optimize facility location and inventory decisions.

Keskin, Burcu Baris

2007-12-01T23:59:59.000Z

295

Sensitivity analysis and optimization of the nuclear fuel cycle : a systematic approach  

E-Print Network (OSTI)

For decades, nuclear energy development was based on the expectation that recycling of the fissionable materials in the used fuel from today's light water reactors into advanced (fast) reactors would be implemented as soon ...

Passerini, Stefano

2012-01-01T23:59:59.000Z

296

Design strategies for optimizing high burnup fuel in pressurized water reactors  

E-Print Network (OSTI)

This work is focused on the strategy for utilizing high-burnup fuel in pressurized water reactors (PWR) with special emphasis on the full array of neutronic considerations. The historical increase in batch-averaged discharge ...

Xu, Zhiwen, 1975-

2003-01-01T23:59:59.000Z

297

Fuels  

NLE Websites -- All DOE Office Websites (Extended Search)

Goals > Fuels Goals > Fuels XMAT for nuclear fuels XMAT is ideally suited to explore all of the radiation processes experienced by nuclear fuels.The high energy, heavy ion accleration capability (e.g., 250 MeV U) can produce bulk damage deep in the sample, achieving neutron type depths (~10 microns), beyond the range of surface sputtering effects. The APS X-rays are well matched to the ion beams, and are able to probe individual grains at similar penetrations depths. Damage rates to 25 displacements per atom per hour (DPA/hr), and doses >2500 DPA can be achieved. MORE» Fuels in LWRs are subjected to ~1 DPA per day High burn-up fuel can experience >2000 DPA. Traditional reactor tests by neutron irradiation require 3 years in a reactor and 1 year cool down. Conventional accelerators (>1 MeV/ion) are limited to <200-400 DPAs, and

298

Performance of Trasuranic-Loaded Fully Ceramic Micro-Encapsulated Fuel in LWRs Interim Report, Including Void Reactivity Evaluation  

Science Conference Proceedings (OSTI)

The current focus of the Deep Burn Project is on once-through burning of transuranice (TRU) in light water reactors (LWRs). The fuel form is called Fully-Ceramic Micro-encapsulated (FCM) fuel, a concept that borrows the tri-isotropic (TRISO) fuel particle design from high-temperature reactor technology. In the Deep Burn LWR (DB-LWR) concept, these fuel particles would be pressed into compacts using SiC matrix material and loaded into fuel pins for use in conventional LWRs. The TRU loading comes from the spent fuel of a conventional LWR after 5 years of cooling. Unit cell calculations have been performed using the DRAGON-4 code in order assess the physics attributes of TRU-only FCM fuel in an LWR lattice. Depletion calculations assuming an infinite lattice condition were performed with calculations of various reactivity coefficients performed at each step. Unit cells containing typical UO2 and MOX fuel were analyzed in the same way to provide a baseline against which to compare the TRU-only FCM fuel. Loading of TRU-only FCM fuel into a pin without significant quantities of uranium challenges the design from the standpoint of several key reactivity parameters, particularly void reactivity, and to some degree, the Doppler coefficient. These unit cells, while providing an indication of how a whole core of similar fuel would behave, also provide information of how individual pins of TRU-only FCM fuel would influence the reactivity behavior of a heterogeneous assembly. If these FCM fuel pins are included in a heterogeneous assembly with LEU fuel pins, the overall reactivity behavior would be dominated by the uranium pins while attractive TRU destruction performance of the TRU-only FCM fuel pins may be preserved. A configuration such as this would be similar to CONFU assemblies analyzed in previous studies. Analogous to the plutonium content limits imposed on MOX fuel, some amount of TRU-only FCM pins in an otherwise-uranium fuel assembly may give acceptable reactivity performance. Assembly calculations will be performed in future work to explore the design options for heterogeneous assemblies of this type and their impact on reactivity coefficients.

Michael A. Pope; Brian Boer; Gilles Youinou; Abderrafi M. Ougouag

2011-03-01T23:59:59.000Z

299

Analysis of drying wood waste fuels with boiler exhaust gases: simulation, performance, and economics  

DOE Green Energy (OSTI)

This study evaluates the feasibility of retrofitting a rotary dryer to a hog fuel boiler, using the boiler exhaust gases as the drying medium. Two simulation models were developed. Each model accurately predicts system performance given site-specific parameters such as boiler steam demand, fue moisture content, boiler exhaust temperature and combustion excess air. Three rotary dryers/hog fuel boilers currently in operation in the forest products industry were analyzed. The data obtained were used to validate te accuracy of the simulation models and to establish the performance of boiler/dryer systems under field conditions. The boiler exhaust temperatures observed ranged from 340 to 500/sup 0/F and indicated that significant drying could be realized at moderate stack temperatures, as substantitated by experimental moisture content data. The simulation models were used to evaluate a general boiler/dryer system's sensitivity to variation in operating conditions. The sensitivity analyses indicated that under moderate conditions (400/sup 0/F boiler exhaust, etc.) the installation of a rotary dryer results in a 15% increase in boiler efficiency and a 13% decrease in fuel consumption. Both the field data and sensitivity analyses indicated that a greater increase in boiler efficiency could be realized at higher stack temperatures, approximately a 30% increase in boiler efficiency for a stack temperature of 600/sup 0/F. The cash flow basis payback periods based on hog fuel savings due to dryer installation ranged from 2.7 years for a used dryer to 3.9 years for a new dryer. The payback periods for equivalent BTU savings of gas and oil ranged from 1.2 to 2.0 for gas and from 1.3 to 2.1 years for oil. This study concludes that retrofitting a rotary dryer to an existing hog fuel boiler is an economically feasible option to the forest products industry. 31 references, 24 figures, 18 tables.

Kirk, R.W.; Wilson, J.B.

1984-09-01T23:59:59.000Z

300

Improving the performance and fuel consumption of dual chamber stratified charge spark ignition engines  

DOE Green Energy (OSTI)

A combined experimental and theoretical investigation of the nature of the combustion processes in a dual chamber stratified charge spark ignition engine is described. This work concentrated on understanding the mixing process in the main chamber gases. A specially constructed single cylinder engine was used to both conduct experiments to study mixing effects and to obtain experimental data for the validation of the computer model which was constructed in the theoretical portion of the study. The test procedures are described. Studies were conducted on the effect of fuel injection timing on performance and emissions using the combination of orifice size and prechamber to main chamber flow rate ratio which gave the best overall compromise between emissions and performance. In general, fuel injection gave slightly higher oxides of nitrogen, but considerably lower hydrocarbon and carbon monoxide emissions than the carbureted form of the engine. Experiments with engine intake port redesign to promote swirl mixing indicated a substantial increase in the power output from the engine and, that an equivalent power levels, the nitric oxide emissions are approximately 30% lower with swirl in the main chamber than without swirl. The development of a computer simulation of the combustion process showed that a one-dimensional combustion model can be used to accurately predict trends in engine operation conditions and nitric oxide emissions even though the actual flame in the engine is not completely one-dimensional, and that a simple model for mixing of the main chamber and prechamber intake gases at the start of compression proved adequate to explain the effects of swirl, ignition timing, overall fuel air ratio, volumetric efficiency, and variations in prechamber air fuel ratio and fuel rate percentage on engine power and nitric oxide emissions. (LCL)

Sorenson, S.C.; Pan, S.S.; Bruckbauer, J.J.; Gehrke, G.R.

1979-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Recent Updates to NRC Fuel Performance Codes and Plans for Future Improvements  

SciTech Connect

FRAPCON-3.4a and FRAPTRAN 1.4 are the most recent versions of the U.S. Nuclear Regulatory Commission (NRC) steady-state and transient fuel performance codes, respectively. These codes have been assessed against separate effects data and integral assessment data and have been determined to provide a best estimate calculation of fuel performance. Recent updates included in FRAPCON-3.4a include updated material properties models, models for new fuel and cladding types, cladding finite element analysis capability, and capability to perform uncertainty analyses and calculate upper tolerance limits for important outputs. Recent updates included in FRAPTRAN 1.4 include: material properties models that are consistent with FRAPCON-3.4a, cladding failure models that are applicable for loss-of coolant-accident and reactivity initiated accident modeling, and updated heat transfer models. This paper briefly describes these code updates and data assessments, highlighting the particularly important improvements and data assessments. This paper also discusses areas of improvements that will be addressed in upcoming code versions.

Geelhood, Kenneth J.

2011-12-31T23:59:59.000Z

302

Performance and Scalability Analysis of Cray X1 Vectorization and Multistreaming Optimization  

SciTech Connect

Cray X1 Fortran and C/C++ compilers provide a number of loop transformations, notably vectorization and multistreaming, in order to exploit the multistreaming processor (MSP) hardware resources and its high memory bandwidth. A Cray X1 node is composed of four MSPs, which in turn are composed of four single streaming processors (SSP). Each SSP contains a superscalar processing unit and two vector processing units. Compiler vectorization provides loop level parallelization and uses the vector processing hardware. Multistreaming code generation by the compiler permits execution across the SSPs of an MSP on a block of code. In this paper, we analyze overall impact of loop-level compiler optimization on a scientific application called Parallel Ocean Program (POP). POP has been extensively optimized for X1 by instrumenting the code using X1 compiler directives. We compare and contrast automatic and manual optimization schemes available on X1 and analyze their impact on the code performance and scalability. Our results show that the addition of compiler directives increases the average vector length, thereby improving the single node performance significantly. However, this code scales at a slower rate as the local workload volume decreases and the communication costs increase.

Alam, Sadaf R [ORNL; Vetter, Jeffrey S [ORNL

2005-05-01T23:59:59.000Z

303

Final Technical Report: Effects of Impurities on Fuel Cell Performance and Durability  

DOE Green Energy (OSTI)

The main objectives of this project were to investigate the effect of a series of potential impurities on fuel cell operation and on the particular components of the fuel cell MEA, to propose (where possible) mechanism(s) by which these impurities affected fuel cell performance, and to suggest strategies for minimizing these impurity effects. The negative effect on Pt/C was to decrease hydrogen surface coverage and hydrogen activation at fuel cell conditions. The negative effect on Nafion components was to decrease proton conductivity, primarily by replacing/reacting with the protons on the Bronsted acid sites of the Nafion. Even though already well known as fuel cell poisons, the effects of CO and NH3 were studied in great detail early on in the project in order to develop methodology for evaluating poisoning effects in general, to help establish reproducibility of results among a number of laboratories in the U.S. investigating impurity effects, and to help establish lower limit standards for impurities during hydrogen production for fuel cell utilization. New methodologies developed included (1) a means to measure hydrogen surface concentration on the Pt catalyst (HDSAP) before and after exposure to impurities, (2) a way to predict conductivity of a Nafion membranes exposed to impurities using a characteristic acid catalyzed reaction (methanol esterification of acetic acid), and, more importantly, (3) application of the latter technique to predict conductivity on Nafion in the catalyst layer of the MEA. H2-D2 exchange was found to be suitable for predicting hydrogen activation of Pt catalysts. The Nafion (ca. 30 wt%) on the Pt/C catalyst resides primarily on the external surface of the C support where it blocks significant numbers of micropores, but only partially blocks the pore openings of the meso- and macro-pores wherein lie the small Pt particles (crystallites). For this reason, even with 30 wt% Nafion on the Pt/C, few Pt sites are blocked and, hence, are accessible for hydrogen activation. Of the impurities studied, CO, NH3, perchloroethylene (also known as tetrachloroethylene), tetrahydrofuran, diborane, and metal cations had significant negative effects on the components in a fuel cell. While CO has no effect on the Nafion, it significantly poisons the Pt catalyst by adsorbing and blocking hydrogen activation. The effect can be reversed with time once the flow of CO is stopped. NH3 has no effect on the Pt catalyst at fuel cell conditions; it poisons the proton sites on Nafion (by forming NH4+ cations), decreasing drastically the proton conductivity of Nafion. This poisoning can slowly be reversed once the flow of NH3 is stopped. Perchloroethylene has a major effect on fuel cell performance. Since it has little/no effect on Nafion conductivity, its poisoning effect is on the Pt catalyst. However, this effect takes place primarily for the Pt catalyst at the cathode, since the presence of oxygen is very important for this poisoning effect. Tetrahydrofuran was shown not to impact Nafion conductivity; however, it does affect fuel cell performance. Therefore, its primary effect is on the Pt catalyst. The effect of THF on fuel cell performance is reversible. Diborane also can significant affect fuel cell performance. This effect is reversible once diborane is removed from the inlet streams. H2O2 is not an impurity usually present in the hydrogen or oxygen streams to a fuel cell. However, it is generated during fuel cell operation. The presence of Fe cations in the Nafion due to system corrosion and/or arising from MEA production act to catalyze the severe degradation of the Nafion by H2O2. Finally, the presence of metal cation impurities (Na+, Ca 2+, Fe3+) in Nafion from MEA preparation or from corrosion significantly impacts its proton conductivity due to replacement of proton sites. This effect is not reversible. Hydrocarbons, such as ethylene, might be expected to affect Pt or Nafion but do not at a typical fuel cell temperature of 80oC. In the presence of large quantities of hydrogen on the anode side, ethylene i

James G. Goodwin, Jr.; Hector Colon-Mercado; Kitiya Hongsirikarn; and Jack Z. Zhang

2011-11-11T23:59:59.000Z

304

Evaluation of weapons-grade mixed oxide fuel performance in U.S. Light Water Reactors using COMETHE 4D release 23 computer code  

E-Print Network (OSTI)

The COMETHE 4D Release 23 computer code was used to evaluate the thermal, chemical and mechanical performance of weapons-grade MOX fuel irradiated under U.S. light water reactor typical conditions. Comparisons were made to and UO? fuels exhibited similar conventional UO? fuel. Weapons-grade MOX behavior. However, MOX fuel rods feature higher fuel centerline temperatures due to a lower thermal conductivity. Moreover, higher diffusion in MOX fuel results in a slightly higher fission gas release. Finally, MOX fuel shows better mechanical behavior than UO? fuel due to lower pellet-cladding mechanical interaction and rod deformation. These results indicate that the MOX fuel meets all potential licensing requirements.

Bellanger, Philippe

1999-01-01T23:59:59.000Z

305

OPTIMIZED FUEL INJECTOR DESIGN FOR MAXIMUM IN-FURNACE NOx REDUCTION AND MINIMUM UNBURNED CARBON  

SciTech Connect

Reaction Engineering International (REI) has established a project team of experts to develop a technology for combustion systems which will minimize NO x emissions and minimize carbon in the fly ash. This much need technology will allow users to meet environmental compliance and produce a saleable by-product. This study is concerned with the NO x control technology of choice for pulverized coal fired boilers, ?in-furnace NO x control,? which includes: staged low-NO x burners, reburning, selective non-catalytic reduction (SNCR) and hybrid approaches (e.g., reburning with SNCR). The program has two primary objectives: 1) To improve the performance of ?in-furnace? NO x control processes. 2) To devise new, or improve existing, approaches for maximum ?in-furnace? NO x control and minimum unburned carbon. The program involves: 1) fundamental studies at laboratory- and bench-scale to define NO reduction mechanisms in flames and reburning jets; 2) laboratory experiments and computer modeling to improve our two-phase mixing predictive capability; 3) evaluation of commercial low-NO x burner fuel injectors to develop improved designs, and 4) demonstration of coal injectors for reburning and low-NO x burners at commercial scale. The specific objectives of the two-phase program are to: 1 Conduct research to better understand the interaction of heterogeneous chemistry and two phase mixing on NO reduction processes in pulverized coal combustion. 2 Improve our ability to predict combusting coal jets by verifying two phase mixing models under conditions that simulate the near field of low-NO x burners. 3 Determine the limits on NO control by in-furnace NO x control technologies as a function of furnace design and coal type. 5 Develop and demonstrate improved coal injector designs for commercial low-NO x burners and coal reburning systems. 6 Modify the char burnout model in REI?s coal combustion code to take account of recently obtained fundamental data on char reactivity during the late stages of burnout. This will improve our ability to predict carbon burnout with low-NO x firing systems.

A.F. SAROFIM; BROWN UNIVERSITY. R.A. LISAUSKAS; D.B. RILEY, INC.; E.G. EDDINGS; J. BROUWER; J.P. KLEWICKI; K.A. DAVIS; M.J. BOCKELIE; M.P. HEAP; REACTION ENGINEERING INTERNATIONAL. D.W. PERSHING; UNIVERSITY OF UTAH. R.H. HURT

1998-01-01T23:59:59.000Z

306

Low cost fuel cell diffusion layer configured for optimized anode water management  

DOE Patents (OSTI)

A fuel cell comprises a cathode gas diffusion layer, a cathode catalyst layer, an anode gas diffusion layer, an anode catalyst layer and an electrolyte. The diffusion resistance of the anode gas diffusion layer when operated with anode fuel is higher than the diffusion resistance of the cathode gas diffusion layer. The anode gas diffusion layer may comprise filler particles having in-plane platelet geometries and be made of lower cost materials and manufacturing processes than currently available commercial carbon fiber substrates. The diffusion resistance difference between the anode gas diffusion layer and the cathode gas diffusion layer may allow for passive water balance control.

Owejan, Jon P; Nicotera, Paul D; Mench, Matthew M; Evans, Robert E

2013-08-27T23:59:59.000Z

307

The electrochemical performance of thin-electrolyte solid oxide fuel cells  

DOE Green Energy (OSTI)

Several benefits are realized by lowering the operating temperature of solid oxide fuel cells (SOFCs) from 1000C to temperatures in the 600 to 800C range. Among the advantages are decreased reaction between fuel cell components, shorter startup times, and the possibility of using metals in stack construction; however, the achievable power density in conventional SOFCs is too low. A strategy for overcoming this limitation is to decrease the thickness of this layer by approximately an order of magnitude. Thin (5 {mu}m) electrolyte SOFCs have recently been fabricated by Allied-Signal Aerospace Systems and Equipment Company (ASASE). The electrochemical performance of these cells has been studied and is discussed in this paper.

Zurawski, D.; Kueper, T.

1993-09-01T23:59:59.000Z

309

Modeling and Optimization of Commercial Buildings and Stationary Fuel Cell Systems (Presentation)  

DOE Green Energy (OSTI)

This presentation describes the Distributed Generation Building Energy Assessment Tool (DG-BEAT) developed by the National Renewable Energy Laboratory and the University of California Irvine. DG-BEAT is designed to allow stakeholders to assess the economics of installing stationary fuel cell systems in a variety of building types in the United States.

Ainscough, C.; McLarty, D.; Sullivan, R.; Brouwer, J.

2013-10-01T23:59:59.000Z

310

A fuzzy diagnosis and advice system for optimization of emissions and fuel consumption  

Science Conference Proceedings (OSTI)

In this study, a fuzzy expert system has been developed, which is used for defining possible fuel system faults, ignition system faults, intake valve and exhaust valve faults and refers solution advice for these faults, which uses measurements of CO, ... Keywords: Diagnosis software, Emissions, Fuzzy expert systems, Spark ignition engine

Yavuz Kilagiz; Ahmet Baran; Zerrin Yildiz; Murat etin

2005-02-01T23:59:59.000Z

311

Optimal Simultaneous Production of Hydrogen and Liquid Fuels from Glycerol: Integrating the  

E-Print Network (OSTI)

fuel production Fischer-Tropsch or methanol synthesis . Moreover, under the reaction conditions hydrocarbons through the Fischer-Tropsch process. To do this, it is necessary to partially oxidize the CH4 production Fischer- Tropsch . Moreover, under the reaction conditions explored, no CO2 was detected, i

Grossmann, Ignacio E.

312

Optimization and Performance of the ATLAS Tau Trigger with Cosmics Data  

E-Print Network (OSTI)

Cosmics data are providing a valuable handle to optimize and commission the ATLAS detector before beam collissions. In this process the ATLAS Tau Trigger is also exercising and adjusting its different components, namely the hardware based first level trigger, and the second and third levels, implemented with software. In this contribution we summarize the performance at the different stages with cosmics events, and compare with Monte Carlo simulation and offline reconstructed muon candidates. We also describe the prospects for initial running with beam collisions, focusing on the commission of the second and third level tau triggers and the strategy to measure the first trigger efficiencies with data.

Shamim, M; The ATLAS collaboration

2009-01-01T23:59:59.000Z

313

Assessment of PCMI Simulation Using the Multidimensional Multiphysics BISON Fuel Performance Code  

SciTech Connect

Since 2008, the Idaho National Laboratory (INL) has been developing a next-generation nuclear fuel performance code called BISON. BISON is built using INLs Multiphysics Object-Oriented Simulation Environment, or MOOSE. MOOSE is a massively parallel, finite element-based framework to solve systems of coupled non-linear partial differential equations using the Jacobian-FreeNewton Krylov (JFNK) method. MOOSE supports the use of complex two- and three-dimensional meshes and uses implicit time integration, which is important for the widely varied time scales in nuclear fuel simulation. MOOSEs object-oriented architecture minimizes the programming required to add new physics models. BISON has been applied to various nuclear fuel problems to assess the accuracy of its 2D and 3D capabilities. The benchmark results used in this assessment range from simulation results from other fuel performance codes to measurements from well-known and documented reactor experiments. An example of a well-documented experiment used in this assessment is the Third Ris Fission Gas Project, referred to as Bump Test GE7, which was performed on rod ZX115. This experiment was chosen because it allows for an evaluation of several aspects of the code, including fully coupled thermo-mechanics, contact, and several nonlinear material models. Bump Test GE7 consists of a base-irradiation period of a full-length rod in the Quad-Cities-1 BWR for nearly 7 years to a burnup of 4.17% FIMA. The base irradiation test is followed by a bump test of a sub-section of the original rod. The bump test takes place in the test reactor DR3 at Ris in a water-cooled HP1 rig under BWR conditions where the power level is increased by about 50% over base irradiation levels in the span of several hours. During base irradiation, the axial power profile is flat. During the bump test, the axial power profile changes so that the bottom half of the rod is at approximately 50% higher power than at the base irradiation level, while the power at the top of the rod is at about 20% of the base irradiation power level. 2D BISON simulations of the Bump Test GE7 were run using both discrete and smeared pellet geometry. Comparisons between these calculations and experimental measurements are presented for clad diameter and elongation after the base irradiation and clad profile along the length of the test section after the bump test. Preliminary comparisons between calculations and measurements are favorable, supporting the use of BISON as an accurate multiphysics fuel simulation tool.

Stephen R. Novascone; Jason D. Hales; Benjamin W. Spencer; Richard L. Williamson

2012-09-01T23:59:59.000Z

314

Performance analysis of developed vegetable-based cutting fluids by D-optimal experimental design in turning process  

Science Conference Proceedings (OSTI)

The aim of this study is to determine the performances of developed vegetable-based cutting fluids VBCFs evaluated as a categorical factor with mineral and semi-synthetic cutting fluids CFs. D-optimal experimental design method in machining was used ... Keywords: D-optimal, EP additive, cutting force, surface roughness, turning, vegetable-based cutting fluids

Emel Kuram; M. Huseyin Cetin; Babur Ozcelik; Erhan Demirbas

2012-12-01T23:59:59.000Z

315

Optimal design and control strategies for novel combined heat and power (CHP) fuel cell systems. Part I of II, datum design conditions and approach.  

SciTech Connect

Energy network optimization (ENO) models identify new strategies for designing, installing, and controlling stationary combined heat and power (CHP) fuel cell systems (FCSs) with the goals of (1) minimizing electricity and heating costs for building owners and (2) reducing emissions of the primary greenhouse gas (GHG) - carbon dioxide (CO{sub 2}). A goal of this work is to employ relatively inexpensive simulation studies to discover more financially and environmentally effective approaches for installing CHP FCSs. ENO models quantify the impact of different choices made by power generation operators, FCS manufacturers, building owners, and governments with respect to two primary goals - energy cost savings for building owners and CO{sub 2} emission reductions. These types of models are crucial for identifying cost and CO{sub 2} optima for particular installations. Optimal strategies change with varying economic and environmental conditions, FCS performance, the characteristics of building demand for electricity and heat, and many other factors. ENO models evaluate both 'business-as-usual' and novel FCS operating strategies. For the scenarios examined here, relative to a base case of no FCSs installed, model results indicate that novel strategies could reduce building energy costs by 25% and CO{sub 2} emissions by 80%. Part I of II articles discusses model assumptions and methodology. Part II of II articles illustrates model results for a university campus town and generalizes these results for diverse communities.

Colella, Whitney G.

2010-06-01T23:59:59.000Z

316

Minimization of Pressurized Water Reactor Radiation Fields through Fuel Deposit Engineering: Deposit Property Evaluation and Optimization  

Science Conference Proceedings (OSTI)

The purpose of this report is to provide an initial assessment of the options for modification of pressurized water reactor (PWR) primary side corrosion product deposits (crud) to minimize the incorporation of activated crud into out-of-core surfaces, thus reducing the intensity of out-of-core radiation fields. This report summarizes the current knowledge of PWR fuel crud characteristics, including crystallographic structure (crystal habits), and buildup mechanisms. The report also reviews the ...

2013-11-11T23:59:59.000Z

317

Design and Optimization of Low Voltage High Performance Dual Threshold CMOS Circuits  

E-Print Network (OSTI)

Reduction in leakage power has become an important concern in lowvoltage, lowpower and high performance applications. In this paper, we use dual threshold technique to reduce leakage power by assigning high threshold voltage to some transistors in non-critical paths, and using lowthreshold transistors in critical paths. In order to achieve the best leakage power saving under target performance constraints, an algorithm is presented for selecting and assigning an optimal high threshold voltage. A general standby leakage current model which has been veri#ed by HSPICE is used to estimate standby leakage power. Results show that dual threshold technique is good for power reduction during both standby and active modes. The standby leakage power savings for some ISCAS benchmarks can be more than 50#. 1 Introduction With the growing use of portable and wireless electronic systems, reduction in power consumption has become more and more importantintoday's VLSI circuit and system designs #1#, ...

Liqiong Wei; Zhanping Chen; Mark Johnson; Kaushik Roy; Vivek De

1998-01-01T23:59:59.000Z

318

Production and Optimization of Direct Coal Liquefaction derived Low Carbon-Footprint Transportation Fuels  

DOE Green Energy (OSTI)

This report summarizes works conducted under DOE Contract No. DE-FC26-05NT42448. The work scope was divided into two categories - (a) experimental program to pretreat and refine a coal derived syncrude sample to meet transportation fuels requirements; (b) system analysis of a commercial scale direct coal liquefaction facility. The coal syncrude was derived from a bituminous coal by Headwaters CTL, while the refining study was carried out under a subcontract to Axens North America. The system analysis included H{sub 2} production cost via six different options, conceptual process design, utilities requirements, CO{sub 2} emission and overall plant economy. As part of the system analysis, impact of various H{sub 2} production options was evaluated. For consistence the comparison was carried out using the DOE H2A model. However, assumptions in the model were updated using Headwaters database. Results of Tier 2 jet fuel specifications evaluation by the Fuels & Energy Branch, US Air Force Research Laboratory (AFRL/RZPF) located at Wright Patterson Air Force Base (Ohio) are also discussed in this report.

Steven Markovich

2010-06-30T23:59:59.000Z

319

Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer  

DOE Green Energy (OSTI)

University of Utah's project entitled 'Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer' (DOE Cooperative Agreement DE-FC26-02NT41490) was developed in response to a solicitation released by the U.S. Department of Energy in December 2001, requesting proposals for projects targeted towards black liquor/biomass gasification technology support research and development. Specifically, the solicitation was seeking projects that would provide technical support for Department of Energy supported black liquor and biomass gasification demonstration projects under development at the time.

Kevin Whitty

2007-06-30T23:59:59.000Z

320

Forced-convection boiling tests performed in parallel simulated LMR fuel assemblies  

SciTech Connect

Forced-convection tests have been carried out using parallel simulated Liquid Metal Reactor fuel assemblies in an engineering-scale sodium loop, the Thermal-Hydraulic Out-of-Reactor Safety facility. The tests, performed under single- and two-phase conditions, have shown that for low forced-convection flow there is significant flow augmentation by thermal convection, an important phenomenon under degraded shutdown heat removal conditions in an LMR. The power and flows required for boiling and dryout to occur are much higher than decay heat levels. The experimental evidence supports analytical results that heat removal from an LMR is possible with a degraded shutdown heat removal system.

Rose, S.D.; Carbajo, J.J.; Levin, A.E.; Lloyd, D.B.; Montgomery, B.H.; Wantland, J.L.

1985-04-21T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
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321

Optimizing the performance of streaming numerical kernels on the IBM Blue Gene/P PowerPC 450 processor  

Science Conference Proceedings (OSTI)

Several emerging petascale architectures use energy-efficient processors with vectorized computational units and in-order thread processing. On these architectures the sustained performance of streaming numerical kernels, ubiquitous in the solution of ... Keywords: Blue Gene/P, SIMD, code generation, high-performance computing, performance optimization

Tareq Malas, Aron J. Ahmadia, Jed Brown, John A. Gunnels, David E. Keyes

2013-05-01T23:59:59.000Z

322

Performance of a small scale boiler burner in the firing of fuel blends  

E-Print Network (OSTI)

Power plants spend nearly 50 billion dollars a year on fuel cost. Presently coal accounts for over 75% of the electricity generated in this country. Due to increasingly harsh environmental regulations, the demand for low sulfur (S) coal has dramatically increased. This increase in demand is expected to cause the price of coal to rise. Such a senario has caused the utilities to explore the possibilities of supplementing coal with fuel alternatives such as the byproducts of process industries. The supplemental fuel for utilities located near feedlots (e.g. Northwest Texas) happens to be feedlot manure. Feedlot manure is attractive because it is nearly ten times cheaper than coal and is relatively inexpensive to transport. There exists nearly six million head of cattle in Northwest Texas which produce 25,000 tons of manure each day. Feedlot manure presents water and air pollution concerns if not disposed of properly. As such, the feedlot operators are eager to find methods of safely disposing of the feedlot manure. A small scale boiler burner facility has been constructed to simulate a utility class boiler. Experiments were conducted with coal only and then for coal/feedlot manure. Three types of feedlot manure are examined; raw feedlot manure, partially composted feedlot manure, and finished composted feedlot manure. Performance characteristics and emission data were taken for each case. A summary of the results is as follows: (I) sulfur Wyoming coal was fired and a gasification efficiency of 66% was measured. (i I) Emissions measurements were recorded and it was seen that emissions of NO,, and S02 increased as the burnt mass fraction increased. However, all emissions were within NSPS guidelines. (iii) The successful firing of coal and feedlot manure was achieved, a gasification efficiency in the range of 86% was measured, which is higher than 66% obtained when firing coal alone. (iv) When the fuel blend is fully burnt, the NO,, emissions with the blend firing was lower than the firing of coal alone.

Frazzitta, Stephen

1993-01-01T23:59:59.000Z

323

High performance metal/air fuel cells. Part 1. General review. [Li, Al, Ca, Cd, Mg  

SciTech Connect

Metal/air fuel cells are reviewed in terms of their potential application in electric vehicles. Attention is focused on those metals (light alkali and alkaline earth metals, and aluminum) which, in combination with oxygen, have theoretical energy densities (2--13 kWh/kg-metal) exceeding that of gasoline (utilized in automobiles at 2--3 kWh/kg). Lithium and aluminum have yielded 8- and 4 kWh/kg, respectively, in laboratory experimental cells. The slurry Zn/air system achieves 0.85 kWh/kg-Zn in prototype vehicle cells and is reviewed for comparison. Calcium can probably yield 1.8 kWh/kg-Ca, but its potential as a fuel has not yet been fully explored. The remaining metals appear to be unsuitable for use in aqueous electrolyte fuel cells. The discharge characteristics of lithium, aluminum, and (possibly) calcium/air cells indicate the potential for electric vehicles of the highway performance and minimum range (300 miles) of subcompact automobiles, rapid refueling for unlimited range extension, and the storage in the fuel cell of sufficient metal for ranges in excess of 1000 miles. Barriers to the concept are the economic necessity of recycling cell reaction products (except in the case of calcium), the expansion or creation of vast metal production industries, and the change-over of existing service station infrastructures to allow electric vehicle servicing. The energy efficiency of a transportation system using aluminum was estimated using data on the current aluminum production industry. The total estimated cost of ownership and operation of an aluminum/air cell was 3.0--3.6 cents/km. The relative rarity of lithium would complicate its use. 6 tables.

Cooper, J. F.

1977-08-15T23:59:59.000Z

324

Simulation of Pellet-Cladding Interaction with the PLEIADES Fuel Performance Software Environment  

Science Conference Proceedings (OSTI)

Technical Paper / Special Issue on the Symposium on Radiation Effects in Ceramic Oxide and Novel LWR Fuels / Fuel Cycle and Management

B. Michel; C. Nonon; J. Sercombe; F. Michel; V. Marelle

325

The Performance of Planar Solid Oxide Fuel Cells using Hydrogen-depleted Coal Syngas.  

E-Print Network (OSTI)

??Since solid oxide fuel cells can operate on fuel containing both hydrogen and carbon monoxide, it may prove possible to remove hydrogen from syngas streams (more)

Burnette, David D.

2007-01-01T23:59:59.000Z

326

Fuel  

E-Print Network (OSTI)

heavy-water-moderated, light-water-moderated and liquid-metal cooled fast breeder reactors fueled with natural or low-enriched uranium and containing thorium mixed with the uranium or in separate target channels. U-232 decays with a 69-year half-life through 1.9-year half-life Th-228 to Tl-208, which emits a 2.6 MeV gamma ray upon decay. We find that pressurized light-water-reactors fueled with LEU-thorium fuel at high burnup (70 MWd/kg) produce U-233 with U-232 contamination levels of about 0.4 percent. At this contamination level, a 5 kg sphere of U-233 would produce a gammaray dose rate of 13 and 38 rem/hr at 1 meter one and ten years after chemical purification respectively. The associated plutonium contains 7.5 percent of the undesirable heat-generating 88-year half-life isotope Pu-238. However, just as it is possible to produce weapon-grade plutonium in low-burnup fuel, it is also practical to use heavy-water reactors to produce U-233 containing only a few ppm of U-232 if the thorium is segregated in target channels and discharged a few times more frequently than the natural-uranium driver fuel. The dose rate from a 5-kg solid sphere of U-233 containing 5 ppm U-232 could be reduced by a further factor of 30, to about 2 mrem/hr, with a close-fitting lead sphere weighing about 100 kg. Thus the proliferation resistance of thorium fuel cycles depends very much upon how they are implemented. The original version of this manuscript was received by Science & Global Security on

Jungmin Kang A

2001-01-01T23:59:59.000Z

327

Design of gasifiers to optimize fuel cell systems. Quarterly technical progress report No. 6, January 1, 1992--March 31, 1992  

DOE Green Energy (OSTI)

The objective of this program is to configure coal gasification/carbonate fuel cell systems that can significantly improve the economics, performance, and efficiency of electric power generation systems. During this quarter the topical report covering Tasks 1, 2, and 3 was submitted. this study evaluates various catalytic gasification/fuel cell power plant configurations. The competitive position of the configurations are assessed in a comparison with present-day as well as emerging alternate coal-based power plant technologies. The work plan for Task 4, Experimental Studies, was also submitted this quarter. This plan outlines the series of tests which will evaluate the feasibility of using the disposable gasification catalysts recommended in Task 3 of this program. (VC)

Not Available

1992-08-01T23:59:59.000Z

328

Characterization, performance and optimization of PVDF as a piezoelectric film for advanced space mirror concepts.  

Science Conference Proceedings (OSTI)

Piezoelectric polymers based on polyvinylidene fluoride (PVDF) are of interest for large aperture space-based telescopes as adaptive or smart materials. Dimensional adjustments of adaptive polymer films depend on controlled charge deposition. Predicting their long-term performance requires a detailed understanding of the piezoelectric material features, expected to suffer due to space environmental degradation. Hence, the degradation and performance of PVDF and its copolymers under various stress environments expected in low Earth orbit has been reviewed and investigated. Various experiments were conducted to expose these polymers to elevated temperature, vacuum UV, {gamma}-radiation and atomic oxygen. The resulting degradative processes were evaluated. The overall materials performance is governed by a combination of chemical and physical degradation processes. Molecular changes are primarily induced via radiative damage, and physical damage from temperature and atomic oxygen exposure is evident as depoling, loss of orientation and surface erosion. The effects of combined vacuum UV radiation and atomic oxygen resulted in expected surface erosion and pitting rates that determine the lifetime of thin films. Interestingly, the piezo responsiveness in the underlying bulk material remained largely unchanged. This study has delivered a comprehensive framework for material properties and degradation sensitivities with variations in individual polymer performances clearly apparent. The results provide guidance for material selection, qualification, optimization strategies, feedback for manufacturing and processing, or alternative materials. Further material qualification should be conducted via experiments under actual space conditions.

Jones, Gary D.; Assink, Roger Alan; Dargaville, Tim Richard; Chaplya, Pavel Mikhail; Clough, Roger Lee; Elliott, Julie M.; Martin, Jeffrey W.; Mowery, Daniel Michael; Celina, Mathew Christopher

2005-11-01T23:59:59.000Z

329

High-burnup fuel and the impact on fuel management  

SciTech Connect

Competition in the electric utility industry has forced utilities to reduce cost. For a nuclear utility, this means a reduction of both the nuclear fuel cost and the operating and maintenance cost. To this extent, utilities are pursuing longer cycles. To reduce the nuclear fuel cost, utilities are trying to reduce batch size while increasing cycle length. Yankee Atomic Electric Company has performed a number of fuel cycle studies to optimize both batch size and cycle length; however, certain burnup-related constraints are encountered. As a result of these circumstances, longer fuel cycles make it increasingly difficult to simultaneously meet the burnup-related fuel design constraints and the technical specification limits. Longer cycles require fuel assemblies to operate for longer times at relatively high power. If utilities continue to pursue longer cycles to help reduce nuclear fuel cost, changes may need to be made to existing fuel burnup limits.

Cacciapouti, R.J.; Weader, R.J. [Yankee Atomic Electric Co., Bolton, MA (United States)

1996-12-31T23:59:59.000Z

330

Interpreting Horizontal Well Flow Profiles and Optimizing Well Performance by Downhole Temperature and Pressure Data  

E-Print Network (OSTI)

Horizontal well temperature and pressure distributions can be measured by production logging or downhole permanent sensors, such as fiber optic distributed temperature sensors (DTS). Correct interpretation of temperature and pressure data can be used to obtain downhole flow conditions, which is key information to control and optimize horizontal well production. However, the fluid flow in the reservoir is often multiphase and complex, which makes temperature and pressure interpretation very difficult. In addition, the continuous measurement provides transient temperature behavior which increases the complexity of the problem. To interpret these measured data correctly, a comprehensive model is required. In this study, an interpretation model is developed to predict flow profile of a horizontal well from downhole temperature and pressure measurement. The model consists of a wellbore model and a reservoir model. The reservoir model can handle transient, multiphase flow and it includes a flow model and a thermal model. The calculation of the reservoir flow model is based on the streamline simulation and the calculation of reservoir thermal model is based on the finite difference method. The reservoir thermal model includes thermal expansion and viscous dissipation heating which can reflect small temperature changes caused by pressure difference. We combine the reservoir model with a horizontal well flow and temperature model as the forward model. Based on this forward model, by making the forward calculated temperature and pressure match the observed data, we can inverse temperature and pressure data to downhole flow rate profiles. Two commonly used inversion methods, Levenberg- Marquardt method and Marcov chain Monte Carlo method, are discussed in the study. Field applications illustrate the feasibility of using this model to interpret the field measured data and assist production optimization. The reservoir model also reveals the relationship between temperature behavior and reservoir permeability characteristic. The measured temperature information can help us to characterize a reservoir when the reservoir modeling is done only with limited information. The transient temperature information can be used in horizontal well optimization by controlling the flow rate until favorite temperature distribution is achieved. With temperature feedback and inflow control valves (ICVs), we developed a procedure of using DTS data to optimize horizontal well performance. The synthetic examples show that this method is useful at a certain level of temperature resolution and data noise.

Li, Zhuoyi

2010-12-01T23:59:59.000Z

331

High Performance Vanadium Redox Flow Batteries with Optimized Electrode Configuration and Membrane Selection  

Science Conference Proceedings (OSTI)

The performance of a vanadium flow battery with no-gap architecture was significantly improved via several techniques. Specifically, gains arising from variation of the overall electrode thickness, membrane thickness, and electrode thermal treatment were studied. There is a trade-off between apparent kinetic losses, mass transfer losses, and ionic resistance as the electrode thickness is varied at the anode and cathode. Oxidative thermal pretreatment of the carbon paper electrode increased the peak power density by 16%. Results of the pretreatment in air showed greater improvement in peak power density compared to that obtained with pretreatment in an argon environment. The highest peak power density in a VRB yet published to the author s knowledge was achieved at a value of 767 mW cm 2 with optimized membrane and electrode engineering. 2012 The Electrochemical Society. [DOI: 10.1149/2.051208jes] All rights reserved.

Liu, Q. H. [University of Tennessee, Knoxville (UTK); Grim, G. M. [University of Tennessee, Knoxville (UTK); Papandrew, A [University of Tennessee, Knoxville (UTK); Turhan, A. [University of Tennessee, Knoxville (UTK); Zawodzinski, Thomas A [ORNL; Mench, Matthew M [ORNL

2012-01-01T23:59:59.000Z

332

Hydrogen Fuel Cells and Storage Technology: Fundamental Research for Optimization of Hydrogen Storage and Utilization  

DOE Green Energy (OSTI)

hydrocarbon-based high-performance sulfonated proton exchange membrane (PEM) that can be manufactured at low cost and accompanied by improved mechanical and thermal stability.

Perret, Bob; Heske, Clemens; Nadavalath, Balakrishnan; Cornelius, Andrew; Hatchett, David; Bae, Chusung; Pang, Tao; Kim, Eunja; Hemmers, Oliver

2011-03-28T23:59:59.000Z

333

Irradiated-Microsphere Gamma Analyzer (IMGA): an integrated system for HTGR coated particle fuel performance assessment  

SciTech Connect

The Irradiated-Microsphere Gamma Analyzer (IMGA) System, designed and built at ORNL, provides the capability of making statistically accurate failure fraction measurements on irradiated HTGR coated particle fuel. The IMGA records the gamma-ray energy spectra from fuel particles and performs quantitative analyses on these spectra; then, using chemical and physical properties of the gamma emitters it makes a failed-nonfailed decision concerning the ability of the coatings to retain fission products. Actual retention characteristics for the coatings are determined by measuring activity ratios for certain gamma emitters such as /sup 137/Cs//sup 95/Zr and /sup 144/Ce//sup 95/Zr for metallic fission product retention and /sup 134/Cs//sup 137/Cs for an indirect measure of gaseous fission product retention. Data from IMGA (which can be put in the form of n failures observed in N examinations) can be accurately described by the binomial probability distribution model. Using this model, a mathematical relationship between IMGA data (n,N), failure fraction, and confidence level was developed. To determine failure fractions of less than or equal to 1% at confidence levels near 95%, this model dictates that from several hundred to several thousand particles must be examined. The automated particle handler of the IMGA system provides this capability. As a demonstration of failure fraction determination, fuel rod C-3-1 from the OF-2 irradiation capsule was analyzed and failure fraction statistics were applied. Results showed that at the 1% failure fraction level, with a 95% confidence level, the fissile particle batch could not meet requirements; however, the fertile particle exceeded these requirements for the given irradiation temperature and burnup.

Kania, M.J.; Valentine, K.H.

1980-02-01T23:59:59.000Z

334

SOLID OXIDE FUEL CELL MANUFACTURING COST MODEL: SIMULATING RELATIONSHIPS BETWEEN PERFORMANCE, MANUFACTURING, AND COST OF PRODUCTION  

DOE Green Energy (OSTI)

The successful commercialization of fuel cells will depend on the achievement of competitive system costs and efficiencies. System cost directly impacts the capital equipment component of cost of electricity (COE) and is a major contributor to the O and M component. The replacement costs for equipment (also heavily influenced by stack life) is generally a major contributor to O and M costs. In this project, they worked with the SECA industrial teams to estimate the impact of general manufacturing issues of interest on stack cost using an activities-based cost model for anode-supported planar SOFC stacks with metallic interconnects. An earlier model developed for NETL for anode supported planar SOFCs was enhanced by a linkage to a performance/thermal/mechanical model, by addition of Quality Control steps to the process flow with specific characterization methods, and by assessment of economies of scale. The 3-dimensional adiabatic performance model was used to calculate the average power density for the assumed geometry and operating conditions (i.e., inlet and exhaust temperatures, utilization, and fuel composition) based on publicly available polarizations curves. The SECA team provided guidance on what manufacturing and design issues should be assessed in this Phase I demonstration of cost modeling capabilities. They considered the impact of the following parameters on yield and cost: layer thickness (i.e., anode, electrolyte, and cathode) on cost and stress levels, statistical nature of ceramic material failure on yield, and Quality Control steps and strategies. In this demonstration of the capabilities of the linked model, only the active stack (i.e., anode, electrolyte, and cathode) and interconnect materials were included in the analysis. Factory costs are presented on an area and kilowatt basis to allow developers to extrapolate to their level of performance, stack design, materials, seal and system configurations, and internal corporate overheads and margin goals.

Eric J. Carlson; Yong Yang; Chandler Fulton

2004-04-20T23:59:59.000Z

335

SiC-CMC-Zircaloy-4 Nuclear Fuel Cladding Performance during 4-Point Tubular Bend Testing  

SciTech Connect

The U.S. Department of Energy Office of Nuclear Energy (DOE NE) established the Light Water Reactor Sustainability (LWRS) program to develop technologies and other solutions to improve the reliability, sustain the safety, and extend the life of current reactors. The Advanced LWR Nuclear Fuel Development Pathway in the LWRS program encompasses strategic research focused on improving reactor core economics and safety margins through the development of an advanced fuel cladding system. Recent investigations of potential options for accident tolerant nuclear fuel systems point to the potential benefits of silicon carbide (SiC) cladding. One of the proposed SiC-based fuel cladding designs being investigated incorporates a SiC ceramic matrix composite (CMC) as a structural material supplementing an internal Zircaloy-4 (Zr-4) liner tube, referred to as the hybrid clad design. Characterization of the advanced cladding designs will include a number of out-of-pile (nonnuclear) tests, followed by in-pile irradiation testing of the most promising designs. One of the out-of-pile characterization tests provides measurement of the mechanical properties of the cladding tube using four point bend testing. Although the material properties of the different subsystems (materials) will be determined separately, in this paper we present results of 4-point bending tests performed on fully assembled hybrid cladding tube mock-ups, an assembled Zr-4 cladding tube mock-up as a standard and initial testing results on bare SiC-CMC sleeves to assist in defining design parameters. The hybrid mock-up samples incorporated SiC-CMC sleeves fabricated with 7 polymer impregnation and pyrolysis (PIP) cycles. To provide comparative information; both 1- and 2-ply braided SiC-CMC sleeves were used in this development study. Preliminary stress simulations were performed using the BISON nuclear fuel performance code to show the stress distribution differences for varying lengths between loading points and clad configurations. The 2-ply sleeve samples show a higher bend momentum compared to those of the 1-ply sleeve samples. This is applicable to both the hybrid mock-up and bare SiC-CMC sleeve samples. Comparatively both the 1- and 2-ply hybrid mock-up samples showed a higher bend stiffness and strength compared with the standard Zr-4 mock-up sample. The characterization of the hybrid mock-up samples showed signs of distress and preliminary signs of fraying at the protective Zr-4 sleeve areas for the 1-ply SiC-CMC sleeve. In addition, the microstructure of the SiC matrix near the cracks at the region of highest compressive bending strain shows significant cracking and flaking. The 2-ply SiC-CMC sleeve samples showed a more bonded, cohesive SiC matrix structure. This cracking and fraying causes concern for increased fretting during the actual use of the design. Tomography was proven as a successful tool to identify open porosity during pre-test characterization. Although there is currently insufficient data to make conclusive statements regarding the overall merit of the hybrid cladding design, preliminary characterization of this novel design has been demonstrated.

IJ van Rooyen; WR Lloyd; TL Trowbridge; SR Novascone; KM Wendt; SM Bragg-Sitton

2013-09-01T23:59:59.000Z

336

Human Performance Optimization: Emerging Management Issues and Artificial Intelligence Methods: Volume 1: Financial Valuation of Hum an Capital  

Science Conference Proceedings (OSTI)

Human performance optimization is critical to all aspects of the energy enterprise. This four-volume report presents findings from a review of the human performance challenges and opportunities created by the changing nature of the energy industry, its workforce, and its work environments.

2001-10-03T23:59:59.000Z

337

Human Performance Optimization: Emerging Management Issues and Artificial Intelligence Methods: Volume 3: Finding and Building Exper tise  

Science Conference Proceedings (OSTI)

Human performance optimization is critical to all aspects of the energy enterprise. This four-volume report presents findings from a review of the human performance challenges and opportunities created by the changing nature of the energy industry, its workforce, and its work environments.

2001-10-03T23:59:59.000Z

338

Human Performance Optimization: Emerging Management Issues and Artificial Intelligence Methods: Volume 2: Forecasting Human Behavior in a Constrained Environment  

Science Conference Proceedings (OSTI)

Human performance optimization is critical to all aspects of the energy enterprise. This four-volume report presents findings from a review of the human performance challenges and opportunities created by the changing nature of the energy industry, its workforce, and its work environments.

2001-10-03T23:59:59.000Z

339

Optimized Icosahedral Grids: Performance of Finite-Difference Operators and Multigrid Solver  

Science Conference Proceedings (OSTI)

This paper discusses the generation of icosahedral hexagonal/pentagonal grids, optimization of the grids, how optimization affects the accuracy of finite-difference Laplacian, Jacobian and divergence operators, and a parallel multigrid solver that ...

Ross P. Heikes; David A. Randall; Celal S. Konor

340

Minimization of Blast furnace Fuel Rate by Optimizing Burden and Gas Distribution  

Science Conference Proceedings (OSTI)

The goal of the research is to improve the competitive edge of steel mills by using the advanced CFD technology to optimize the gas and burden distributions inside a blast furnace for achieving the best gas utilization. A state-of-the-art 3-D CFD model has been developed for simulating the gas distribution inside a blast furnace at given burden conditions, burden distribution and blast parameters. The comprehensive 3-D CFD model has been validated by plant measurement data from an actual blast furnace. Validation of the sub-models is also achieved. The user friendly software package named Blast Furnace Shaft Simulator (BFSS) has been developed to simulate the blast furnace shaft process. The research has significant benefits to the steel industry with high productivity, low energy consumption, and improved environment.

Dr. Chenn Zhou

2012-08-15T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Improved performance of U-Mo dispersion fuel by Si addition in Al matrix.  

SciTech Connect

The purpose of this report is to collect in one publication and fit together work fragments presented in many conferences in the multi-year time span starting 2002 to the present dealing with the problem of large pore formation in U-Mo/Al dispersion fuel plates first observed in 2002. Hence, this report summarizes the excerpts from papers and reports on how we interpreted the relevant results from out-of-pile and in-pile tests and how this problem was dealt with. This report also provides a refined view to explain in detail and in a quantitative manner the underlying mechanism of the role of silicon in improving the irradiation performance of U-Mo/Al.

Kim, Y S; Hofman, G L [Nuclear Engineering Division

2011-06-01T23:59:59.000Z

342

Appendix model performance - model documentation renewable fuels module of the National Energy Modeling System  

DOE Green Energy (OSTI)

This appendix discusses performance aspects of the Renewable Fuels Module (RFM). It is intended to present the pattern of response of the RFM to typical changes in its major inputs from other NEMS modules. The overall approach of this document, with the particular statistics presented, is designed to be comparable with similar analyses conducted for all of the modules of NEMS. While not always applicable, the overall approach has been to produce analyses and statistics that are as comparable as possible with model developer`s reports for other NEMS modules. Those areas where the analysis is somewhat limited or constrained are discussed. Because the RFM consists of independent submodules, this appendix is broken down by submodule.

Not Available

1994-09-01T23:59:59.000Z

343

Solid oxide fuel cell/gas turbine power plant cycles and performance estimates  

DOE Green Energy (OSTI)

SOFC pressurization enhances SOFC efficiency and power performance. It enables the direct integration of the SOFC and gas turbine technologies which can form the basis for very efficient combined- cycle power plants. PSOFC/GT cogeneration systems, producing steam and/or hot water in addition to electric power, can be designed to achieve high fuel effectiveness values. A wide range of steam pressures and temperatures are possible owing to system component arrangement flexibility. It is anticipated that Westinghouse will offer small PSOFC/GT power plants for sale early in the next decade. These plants will have capacities less than 10 MW net ac, and they will operate with efficiencies in the 60-65% (net ac/LHV) range.

Lundberg, W.L.

1996-12-31T23:59:59.000Z

344

Design and reliability optimization of a MEMS micro-hotplate for combustion of gaseous fuel  

SciTech Connect

This report will detail the process by which the silicon carbide (SiC) microhotplate devices, manufactured by GE, were imaged using IR microscopy equipment available at Sandia. The images taken were used as inputs to a finite element modeling (FEM) process using the ANSYS software package. The primary goal of this effort was to determine a method to measure the temperature of the microhotplate. Prior attempts to monitor the device's temperature by measuring its resistance had proven to be unreliable due to the nonlinearity of the doped SiC's resistance with temperature. As a result of this thermal modeling and IR imaging, a number of design recommendations were made to facilitate this temperature measurement. The lower heating value (LHV) of gaseous fuels can be measured with a catalyst-coated microhotplate calorimeter. GE created a silicon carbide (SiC) based microhotplate to address high-temperature survivability requirements for the application. The primary goal of this effort was to determine a method to measure the temperature of the microhotplate. Prior attempts to monitor the device's temperature by measuring its resistance had proven to be unreliable due to the non-linearity of the doped SiC's resistance with temperature. In this work, thermal modeling and IR imaging were utilized to determine the operation temperature as a function of parameters such as operation voltage and device sheet resistance. A number of design recommendations were made according to this work.

Manginell, R. P.

2012-03-01T23:59:59.000Z

345

Sensitivity of economic performance of the nuclear fuel cycle to simulation modeling assumptions  

E-Print Network (OSTI)

Comparing different nuclear fuel cycles and assessing their implications require a fuel cycle simulation model as complete and realistic as possible. In this thesis, methodological implications of modeling choices are ...

Bonnet, Nicphore

2007-01-01T23:59:59.000Z

346

Exploration of Optimization Options for Increasing Performance of a GPU Implementation of a Three-dimensional Bilateral Filter  

SciTech Connect

This report explores using GPUs as a platform for performing high performance medical image data processing, specifically smoothing using a 3D bilateral filter, which performs anisotropic, edge-preserving smoothing. The algorithm consists of a running a specialized 3D convolution kernel over a source volume to produce an output volume. Overall, our objective is to understand what algorithmic design choices and configuration options lead to optimal performance of this algorithm on the GPU. We explore the performance impact of using different memory access patterns, of using different types of device/on-chip memories, of using strictly aligned and unaligned memory, and of varying the size/shape of thread blocks. Our results reveal optimal configuration parameters for our algorithm when executed sample 3D medical data set, and show performance gains ranging from 30x to over 200x as compared to a single-threaded CPU implementation.

Bethel, E. Wes; Bethel, E. Wes

2012-01-06T23:59:59.000Z

347

E85 Optimized Engine  

SciTech Connect

A 5.0L V8 twin-turbocharged direct injection engine was designed, built, and tested for the purpose of assessing the fuel economy and performance in the F-Series pickup of the Dual Fuel engine concept and of an E85 optimized FFV engine. Additionally, production 3.5L gasoline turbocharged direct injection (GTDI) ??EcoBoost? engines were converted to Dual Fuel capability and used to evaluate the cold start emissions and fuel system robustness of the Dual Fuel engine concept. Project objectives were: to develop a roadmap to demonstrate a minimized fuel economy penalty for an F-Series FFV truck with a highly boosted, high compression ratio spark ignition engine optimized to run with ethanol fuel blends up to E85; to reduce FTP 75 energy consumption by 15% - 20% compared to an equally powered vehicle with a current production gasoline engine; and to meet ULEV emissions, with a stretch target of ULEV II / Tier II Bin 4. All project objectives were met or exceeded.

Stanley Bower

2011-12-31T23:59:59.000Z

348

Guidelines for Estimating ESP Performance When Switching to Alternate Fuels: Interim Report  

Science Conference Proceedings (OSTI)

Fuel flexibility has always been an important issue for power producers, as the cost of fuel is a major factor in the cost of generating electricity. More recently, the practice of fuel switching to meet sulfur dioxide emission limits has shown the effect of alternate fuels on combustion equipment, scrubbers, and electrostatic precipitators to be a more important and complicated issue. EPRI has developed tools that address all aspects of this issue and, in particular, has developed a number of tools to p...

2002-02-22T23:59:59.000Z

349

Performance Study on Multilevel Hybrid Power System of Pneumatic-fuel Vehicle  

Science Conference Proceedings (OSTI)

Put forward the concept of multilevel hybrid power system of pneumatic-Fuel Vehicle, composed of the gasoline engine and pneumatic motor which is droved by the admixture of compressed air and engine exhaust gas so as to improve the dynamics. The dynamics ... Keywords: fuel-pneumatic, multilevel hybrid power vehicle, dynamics, fuel consumption

Wang Guo-ye; Zhang Juan-li; Chou Xiao-gang; Wang Jun; Zheng Chang-song

2011-01-01T23:59:59.000Z

350

The effects of halides on the performance of coal gas-fueled molten carbonate fuel cells: Final report, October 1986-October 1987  

DOE Green Energy (OSTI)

This report presents the results of a program to determine the probable tolerable limits of hydrogen chloride and hydrogen fluoride present in the fuel and oxidant streams of molten carbonate fuel cells that are operating on gasified coal. A literature survey and thermodynamic analyses were performed to determine the likely effects of halides on cell performance and materials. Based on the results of these studies, accelerated corrosion experiments and electrode half-cell performance tests were conducted using electrolyte which contained chloride and fluoride. These data and the results of previous in-cell tests were used to develop a computer for predicting the performance decay due to these halides. The tolerable limits were found to be low (less than 1 PPM) and depend on the power plant system configuration, the operating conditions of the fuel cell stack, the cell design and initial electrolyte inventory, and the ability of the cell to scrub low levels of halide from the reactant streams. The primary decay modes were conversion of the electrolyte from pure carbonate to a carbonate-halide mixture and accelerated electrolyte evaporation. 75 figs., 16 tabs.

Magee, T.P.; Kunz, H.R.; Krasij, M.; Cote, H.A.

1987-10-01T23:59:59.000Z

351

Effects of coal-derived trace species on the performance of molten carbonate fuel cells. Topical report on thermochemical studies  

DOE Green Energy (OSTI)

The overall objective of the present study was to determine in detail the interaction effects of 10 simultaneously present, coal-gas contaminants, both on each other and on components of the Carbonate Fuel Cell. The primary goal was to assess underlying chemistries and reaction mechanisms which may cause decay in fuel cell performance or endurance as a result of both physics-chemical and/or mechanical interactions with the cell components and internal fuel cell parts. It was found, both from theory and cell test evidence, that trace contaminant interactions may occur with: Fuel-cell Electrodes (e.g., in this study with the Ni-anode), Lithium/Potassium Carbonate Electrolyte, Nickel and SS-Hardware, and by Mechanical Obstruction of Gas Flow in the Anode Plenum.

Pigeaud, A.

1991-10-01T23:59:59.000Z

352

Methodologies and new user interfaces to optimize hydraulic fracturing design and evaluate fracturing performance for gas wells  

E-Print Network (OSTI)

This thesis presents and develops efficient and effective methodologies for optimal hydraulic fracture design and fracture performance evaluation. These methods incorporate algorithms that simultaneously optimize all of the treatment parameters while accounting for required constraints. Damage effects, such as closure stress, gel damage and non-Darcy flow, are also considered in the optimal design and evaluation algorithms. Two user-friendly program modules, which are active server page (ASP) based, were developed to implement the utility of the methodologies. Case analysis was executed to demonstrate the workflow of the two modules. Finally, to validate the results from the two modules, results were compared to those from a 3D simulation program. The main contributions of this work are: An optimal fracture design methodology called unified fracture design (UFD) is presented and damage effects are considered in the optimal design calculation. As a by-product of UFD, a fracture evaluation methodology is proposed to conduct well stimulation performance evaluation. The approach is based on calculating and comparing the actual dimensionless productivity index of fractured wells with the benchmark which has been developed for optimized production. To implement the fracture design and evaluation methods, two web ASP based user interfaces were developed; one is called Frac Design (Screening), and the other is Frac Evaluation. Both modules are built to hold the following features. o Friendly web ASP based user interface o Minimum user input o Proppant type and mesh size selection o Damage effects consideration options o Convenient on-line help.

Wang, Wenxin

2005-12-01T23:59:59.000Z

353

OPTIMIZATION OF THE CATHODE LONG-TERM STABILITY IN MOLTEN CARBONATE FUEL CELLS: EXPERIMENTAL STUDY AND MATHEMATICAL MODELING  

DOE Green Energy (OSTI)

The dissolution of NiO cathodes during cell operation is a limiting factor to the successful commercialization of molten carbonate fuel cells (MCFCs). Lithium cobalt oxide coating onto the porous nickel electrode has been adopted to modify the conventional MCFC cathode which is believed to increase the stability of the cathodes in the carbonate melt. The material used for surface modification should possess thermodynamic stability in the molten carbonate and also should be electro catalytically active for MCFC reactions. Two approaches have been adopted to get a stable cathode material. First approach is the use of LiNi{sub 0.8}Co{sub 0.2}O{sub 2}, a commercially available lithium battery cathode material and the second is the use of tape cast electrodes prepared from cobalt coated nickel powders. The morphology and the structure of LiNi{sub 0.8}Co{sub 0.2}O{sub 2} and tape cast Co coated nickel powder electrodes were studied using scanning electron microscopy and X-Ray diffraction studies respectively. The electrochemical performance of the two materials was investigated by electrochemical impedance spectroscopy and polarization studies. A three phase homogeneous model was developed to simulate the performance of the molten carbonate fuel cell cathode. The homogeneous model is based on volume averaging of different variables in the three phases over a small volume element. The model gives a good fit to the experimental data. The model has been used to analyze MCFC cathode performance under a wide range of operating conditions.

Dr. Ralph E. White; Dr. Branko N. Popov

2002-04-01T23:59:59.000Z

354

Domain Decomposition Methods in Optimal Flow Control for High Performance Computing.  

E-Print Network (OSTI)

??This thesis is concerned with linear and non-linear optimal flow control problems which are modeled by systems of partial differential equations. The numerical treatment of (more)

Ketelaer, Eva

2013-01-01T23:59:59.000Z

355

OPTIMIZATION OF THE CATHODE LONG-TERM STABILITY IN MOLTEN CARBONATE FUEL CELLS: EXPERIMENTAL STUDY AND MATHEMATICAL MODELING  

DOE Green Energy (OSTI)

This project focused on addressing the two main problems associated with state of art Molten Carbonate Fuel Cells, namely loss of cathode active material and stainless steel current collector deterioration due to corrosion. We followed a dual approach where in the first case we developed novel materials to replace the cathode and current collector currently used in molten carbonate fuel cells. In the second case we improved the performance of conventional cathode and current collectors through surface modification. States of art NiO cathode in MCFC undergo dissolution in the cathode melt thereby limiting the lifetime of the cell. To prevent this we deposited cobalt using an electroless deposition process. We also coated perovskite (La{sub 0.8}Sr{sub 0.2}CoO{sub 3}) in NiO thorough a sol-gel process. The electrochemical oxidation behavior of Co and perovskites coated electrodes is similar to that of the bare NiO cathode. Co and perovskite coatings on the surface decrease the dissolution of Ni into the melt and thereby stabilize the cathode. Both, cobalt and provskites coated nickel oxide, show a higher polarization compared to that of nickel oxide, which could be due to the reduced surface area. Cobalt substituted lithium nickel oxide (LiNi{sub 0.8}Co{sub 0.2}O{sub 2}) and lithium cobalt oxide were also studied. LiNi{sub x}Co{sub 1-x}O{sub 2} was synthesized by solid-state reaction procedure using lithium nitrate, nickel hydroxide and cobalt oxalate precursor. LiNi{sub x}Co{sub 1-x}O{sub 2} showed smaller dissolution of nickel than state of art nickel oxide cathode. The performance was comparable to that of nickel oxide. The corrosion of the current collector in the cathode side was also studied. The corrosion characteristics of both SS304 and SS304 coated with Co-Ni alloy were studied. This study confirms that surface modification of SS304 leads to the formation of complex scales with better barrier properties and better electronic conductivity at 650 C. A three phase homogeneous model was developed to simulate the performance of the molten carbonate fuel cell cathode and the complete fuel cell. The homogeneous model is based on volume averaging of different variables in the three phases over a small volume element. This approach can be used to model porous electrodes as it represents the real system much better than the conventional agglomerate model. Using the homogeneous model the polarization characteristics of the MCFC cathode and fuel cell were studied under different operating conditions. Both the cathode and the full cell model give good fits to the experimental data.

Hector Colonmer; Prabhu Ganesan; Nalini Subramanian; Dr. Bala Haran; Dr. Ralph E. White; Dr. Branko N. Popov

2002-09-01T23:59:59.000Z

356

Determining System Parameters for Optimal Performance of Hybrid DS/FFH Spread-Spectrum  

SciTech Connect

In recent years there has been great interest in using hybrid spread-spectrum (HSS) techniques for commercial applications, particularly in the Smart Grid, in addition to their use in military communications because they accommodate high data rates with high link integrity, even in the presence of significant multipath effects and interfering signals. A highly useful form of this transmission technique for many types of command, control, and sensing applications is the specific code-related combination of standard direct sequence (DS) modulation with "fast" frequency hopping (FFH), denoted hybrid DS/FFH, wherein multiple frequency hops occur within a single data-bit time. In this paper, an optimization problem is formulated that maximizes the DS/FFH communication system performance in terms of probability of bit error and solves for the system design parameters. The objective function is non-convex and can be solved by applying the Karush-Kuhn-Tucker conditions. System design parameters of interest are the length of the DS code sequence, number of frequency hopping channels, number of channels corrupted by wide-band jamming, and number of hops per bit. The proposed formulation takes into account the effects from wide-band and partial-band jamming, multi-user interference and/or varying degrees of Rayleigh and Rician multipath fading. Numerical results are presented to demonstrate the method s viability.

Ma, Xiao [ORNL; Olama, Mohammed M [ORNL; Kuruganti, Phani Teja [ORNL; Smith, Stephen Fulton [ORNL; Djouadi, Seddik M [ORNL

2012-01-01T23:59:59.000Z

357

Measure Guideline: Condensing Boilers - Control Strategies for Optimizing Performance and Comfort in Residential Applications  

Science Conference Proceedings (OSTI)

The combination of a gas-fired condensing boiler with baseboard convectors and an indirect water heater has become a common option for high-efficiency residential space heating in cold climates. While there are many condensing boilers available on the market with rated efficiencies in the low to mid 90% efficient range, it is imperative to understand that if the control systems are not properly configured, these heaters will perform no better than their non-condensing counterparts. Based on previous research efforts, it is apparent that these types of systems are typically not designed and installed to achieve maximum efficiency (Arena 2010). It was found that there is a significant lack of information for contractors on how to configure the control systems to optimize overall efficiency. For example, there is little advice on selecting the best settings for the boiler reset curve or how to measure and set flow rates in the system to ensure that the return temperatures are low enough to promote condensing. It has also been observed that recovery from setback can be extremely slow and, at times, not achieved. Recovery can be affected by the outdoor reset control, the differential setting on the boiler and over-sizing of the boiler itself. This guide is intended for designers and installers of hydronic heating systems interested in maximizing the overall system efficiency of condensing boilers when coupled with baseboard convectors. It is applicable to new and retrofit applications.

Arena, L.

2013-05-01T23:59:59.000Z

358

The second generation of optimized beam orbit measurement (BOM) system of LEP hardware and performance description  

E-Print Network (OSTI)

The BOM System with its 504 Beam Position Monitors and 40 Processing Electronics Stations, distributed along the 27 km of the LEP tunnel, has been optimized for all beam conditions and modes of operation. The description of the Beam Position Monitors (or PU) behavior in the tunnel is given. The guiding approaches for obtaining both main aspects of the critical BOM performances were: a) high reliability, since most of the electronics is not accessible during operation, and b) resolution, precision and stability of the signal processing equipment for the management of the LEP optics, polarization and energy calibration. The finalized analog signal processing chains, both Wide-Band and Narrow-Band, are described. Since local memories allow for the recording of data at each bunch passage during more than 1000 revolutions, it can be followed by a powerful digital signal processing allowing for many modes of beam observation. Examples are presented of beam and machine behavior studies. The BOM System has been a key...

Borer, J; Manarin, A; Vismara, Giuseppe

1995-01-01T23:59:59.000Z

359

Performance of solid oxide fuel cells operaated with coal syngas provided directly from a gasification process  

Science Conference Proceedings (OSTI)

Solid oxide fuel cells (SOFCs) are being developed for integrated gasification power plants that generate electricity from coal at 50% efficiency. The interaction of trace metals in coal syngas with Ni-based SOFC anodes is being investigated through thermodynamic analyses and in laboratory experiments, but test data from direct coal syngas exposure are sparsely available. This effort evaluates the significance of performance losses associated with exposure to direct coal syngas. Specimen are operated in a unique mobile test skid that is deployed to the research gasifier at NCCC in Wilsonville, AL. The test skid interfaces with a gasifier slipstream to deliver hot syngas to a parallel array of twelve SOFCs. During the 500 h test period, all twelve cells are monitored for performance at four current densities. Degradation is attributed to syngas exposure and trace material attack on the anode structure that is accelerated at increasing current densities. Cells that are operated at 0 and 125 mA cm{sup 2} degrade at 9.1 and 10.7% per 1000 h, respectively, while cells operated at 250 and 375 mA cm{sup 2} degrade at 18.9 and 16.2% per 1000 h, respectively. Spectroscopic analysis of the anodes showed carbon, sulfur, and phosphorus deposits; no secondary Ni-metal phases were found.

Hackett, G.; Gerdes, K.; Song, X.; Chen, Y.; Shutthanandan, V.; Englehard, M.; Zhu, Z.; Thevuthasan, S.; Gemmen, R.

2012-01-01T23:59:59.000Z

360

Achieving New Source Performance Standards (NSPS) Emission Standards Through Integration of Low-NOx Burners with an Optimization Plan for Boiler Combustion  

SciTech Connect

The objective of this project was to demonstrate the use of an Integrated Combustion Optimization System to achieve NO{sub X} emission levels in the range of 0.15 to 0.22 lb/MMBtu while simultaneously enabling increased power output. The project plan consisted of the integration of low-NO{sub X} burners and advanced overfire air technology with various process measurement and control devices on the Holcomb Station Unit 1 boiler. The plan included the use of sophisticated neural networks or other artificial intelligence technologies and complex software to optimize several operating parameters, including NO{sub X} emissions, boiler efficiency, and CO emissions. The program was set up in three phases. In Phase I, the boiler was equipped with sensors that can be used to monitor furnace conditions and coal flow to permit improvements in boiler operation. In Phase II, the boiler was equipped with burner modifications designed to reduce NO{sub X} emissions and automated coal flow dampers to permit on-line fuel balancing. In Phase III, the boiler was to be equipped with an overfire air system to permit deep reductions in NO{sub X} emissions. Integration of the overfire air system with the improvements made in Phases I and II would permit optimization of boiler performance, output, and emissions. This report summarizes the overall results from Phases I and II of the project. A significant amount of data was collected from the combustion sensors, coal flow monitoring equipment, and other existing boiler instrumentation to monitor performance of the burner modifications and the coal flow balancing equipment.

Wayne Penrod

2006-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

An on-line performance optimization of the Switched Reluctance Motor  

E-Print Network (OSTI)

The Switched Reluctance Motor (SRM) has been developed extensively during the past 15 years. Due to the simple motor construction and power converter requirements, SRM drives have been found competitive with traditional AC and DC drives. Optimal performance of the SRM drive may be described by different figures of merit such as drive efficiency, torque per ampere and torque ripple. This thesis addresses the problem of obtaining 'maximum torque per ampere' from the motor. The control of torque and speed in the SRM drive is complex due to the nonlinear relationship between the input variables (phase current magnitude and switching instants) and the motor torque. 'Tuning' of the drive is defined as the process of determining the set of input variables that results in maximum torque per ampere (TPA) at the required speed and load torque. The existence and uniqueness of a solution' to the maximum TPA problem are demonstrated by computer simulation of the machine model, using measured data of the inductance profile from an SRM. Due to manufacturing tolerances, the inductance profiles of the SRM show variations from phase to phase. Furthermore, the profiles may change with time due to effects such as wear on the bearings. A 'self-tuning' control strategy is proposed to compensate for these variations. An algorithm has been developed to maximize TPA on-line, while the SRM is running. It is based on perturbing the input variables and measuring the TPA after each change. This does not involve any complex computations based on the machine model but, just requires measurement of the observable variables of the drive system such as speed and current. The above strategy has been implemented on an SRM test bed with a 16-bit microcontroller. The drive operation is constrained to be in the lowspeed, chopping current control mode. A shaft position sensor is employed for commutation. Experimental results show the increase in TPA after execution of the optimization algorithm, Thus, a real-time self-tuning controller has been demonstrated, that is applicable to all SRM drives with shaft position sensors.

Tandon, Piyush

1996-01-01T23:59:59.000Z

362

Comparative Environmental Performance of Two-Diesel-Fuel Oxygenates: Dibutyl Maleate (DBM) and Triproplyene Glycol Monomethyl Ether (TGME)  

DOE Green Energy (OSTI)

Many studies have shown that the addition of oxygen bearing compounds to diesel fuel can significantly reduce particulate emissions. To assist in the evaluation of the environmental performance of diesel-fuel oxygenates, we have implemented a suite of diagnostic models for simulating the transport of compounds released to air, water, and soils/groundwater as well as regional landscapes. As a means of studying the comparative performance of DBM and TGME, we conducted a series of simulations for selected environmental media. Benzene and methyl tertiary butyl ether (MTBE) were also addressed because they represent benchmark fuel-related compounds that have been the subject of extensive environmental measurements and modeling. The simulations showed that DBM and TGME are less mobile in soil because of reduced vapor-phase transport and increased retention on soil particles. The key distinction between these two oxygenates is that DBM is predicted to have a greater potential than TGME for aerobic biodegradation, based on chemical structure.

Layton, D.W.; Marchetti, A.A.

2001-10-01T23:59:59.000Z

363

DOE Hydrogen and Fuel Cells Program Record 9017: On-Board Hydrogen Storage Systems … Projected Performance and Cost Parameters  

NLE Websites -- All DOE Office Websites (Extended Search)

DOE Hydrogen and Fuel Cells Program Record DOE Hydrogen and Fuel Cells Program Record Record #: 9017 Date: July 02, 2010 Title: On-Board Hydrogen Storage Systems - Projected Performance and Cost Parameters Originators: Robert C. Bowman and Ned Stetson Approved by: Sunita Satyapal Date: August 10, 2010 This record summarizes the current technical assessments of hydrogen (H 2 ) storage system capacities and projected manufacturing costs for the scenario of high-volume production (i.e., 500,000 units/year) for various types of "on-board" vehicular storage systems. These analyses were performed within the Hydrogen Storage sub-program of the DOE Fuel Cell Technologies (FCT) program of the Office of Energy Efficiency and Renewable Energy. Item: It is important to note that all system capacities are "net useable capacities" able to be delivered to the

364

CFD optimization for GDI spray model tuning and enhancement of engine performance  

Science Conference Proceedings (OSTI)

Coupling a 3D Computational Fluid Dynamics (CFD) tool with a rigorous method of decision making is becoming indispensable in the design process of complex systems, as internal combustion engines. CFD based optimization (CFD-O) is here carried out on ... Keywords: CFD based optimization, Charge stratification, Gasoline direct injection, Multidimensional modelling, Spark ignition engines, Split injection

M. Costa; U. Sorge; L. Allocca

2012-07-01T23:59:59.000Z

365

Performance-centering optimization for system-level analog design exploration  

Science Conference Proceedings (OSTI)

In this paper we propose a novel analog design optimization methodology to address two key aspects of top-down system-level design: (1) how to optimally compare and select analog system architectures in the early phases of design; and (2) how to hierarchically ...

Xin Li; Jian Wang; L. T. Pileggi; Tun-Shih Chen; Wanju Chiang

2005-05-01T23:59:59.000Z

366

Performance of solid oxide fuel cells operated with coal syngas provided directly from a gasification process  

Science Conference Proceedings (OSTI)

Solid oxide fuel cells (SOFCs) are presently being developed for gasification integrated power plants that generate electricity from coal at 50+% efficiency. The interaction of trace metals in coal syngas with the Ni-based SOFC anodes is being investigated through thermodynamic analyses and in laboratory experiments, but direct test data from coal syngas exposure are sparsely available. This research effort evaluates the significance of SOFC performance losses associated with exposure of a SOFC anode to direct coal syngas. SOFC specimen of industrially relevant composition are operated in a unique mobile test skid that was deployed to the research gasifier at the National Carbon Capture Center (NCCC) in Wilsonville, AL. The mobile test skid interfaces with a gasifier slipstream to deliver hot syngas (up to 300C) directly to a parallel array of 12 button cell specimen, each of which possesses an active area of approximately 2 cm2. During the 500 hour test period, all twelve cells were monitored for performance at four discrete operating current densities, and all cells maintained contact with a data acquisition system. Of these twelve, nine demonstrated good performance throughout the test, while three of the cells were partially compromised. Degradation associated with the properly functioning cells was attributed to syngas exposure and trace material attack on the anode structure that was accelerated at increasing current densities. Cells that were operated at 0 and 125 mA/cm degraded at 9.1 and 10.7% per 1000 hours, respectively, while cells operated at 250 and 375 mA/cm degraded at 18.9 and 16.2% per 1000 hours, respectively. Post-trial spectroscopic analysis of the anodes showed carbon, sulfur, and phosphorus deposits; no secondary Ni-metal phases were found.

Hackett, Gregory A.; Gerdes, Kirk R.; Song, Xueyan; Chen, Yun; Shutthanandan, V.; Engelhard, Mark H.; Zhu, Zihua; Thevuthasan, Suntharampillai; Gemmen, Randall

2012-09-15T23:59:59.000Z

367

A novel fractional order fuzzy PID controller and its optimal time domain tuning based on integral performance indices  

Science Conference Proceedings (OSTI)

A novel fractional order (FO) fuzzy Proportional-Integral-Derivative (PID) controller has been proposed in this paper which works on the closed loop error and its fractional derivative as the input and has a fractional integrator in its output. The fractional ... Keywords: FLC tuning, Fractional order controller, Fuzzy PID, Genetic algorithm, Integral performance indices, Optimal PID tuning

Saptarshi Das; Indranil Pan; Shantanu Das; Amitava Gupta

2012-03-01T23:59:59.000Z

368

Request Bridging and Interleaving: Improving the Performance of Small Synchronous Updates under Seek-Optimizing Disk Subsystems  

Science Conference Proceedings (OSTI)

Write-through caching in modern disk drives enables the protection of data in the event of power failures as well as from certain disk errors when the write-back cache does not. Host system can achieve these benefits at the price of significant performance ... Keywords: Request merging, cross-layer optimizations, disk drive, disk scheduling algorithm, trace-driven analysis

Dong In Shin; Young Jin Yu; Hyeong S. Kim; Hyeonsang Eom; Heon Young Yeom

2011-07-01T23:59:59.000Z

369

Disposition of Unirradiated Sodium Bonded EBR-II Driver Fuel Elements and HEU Scrap: Work Performed for FY 2007  

SciTech Connect

Specific surplus high enriched uranium (HEU) materials at the Idaho National Laboratory (INL) Materials and Fuels Complex (MFC) will be transferred to a designated off-site receiving facility. The DOE High Enriched Uranium Disposition Program Office (HDPO) will determine which materials, if any, will be prepared and transferred to an off-site facility for processing and eventual fabrication of fuel for nuclear reactors. These surplus HEU materials include approximately 7200 kg unirradiated sodium-bonded EBR-II driver fuel elements, and nearly 800 kg of HEU casting scrap from the process which formed various sodium-bonded fuels (including the EBR-II driver elements). Before the driver fuel can be packaged for shipment, the fuel elements will require removal of the sodium bond. The HEU scrap will also require repackaging in preparation for off-site transport. Preliminary work on this task was authorized by BWXT Y-12 on Nov 6, 2006 and performed in three areas: Facility Modifications Safety Documentation Project Management

Karen A Moore

2007-04-01T23:59:59.000Z

370

Modeling and control of a hybrid electric drivetrain for optimum fuel economy, performance and driveability.  

E-Print Network (OSTI)

??Automotive manufacturers have been striving for decades to produce vehicles which satisfy customers requirements at minimum cost. Many of their concerns are on fuel economy, (more)

Wei, Xi

2004-01-01T23:59:59.000Z

371

Design of gasifiers to optimize fuel cell systems. Quarterly technical progress report No. 9, October 1, 1992--December 31, 1992  

DOE Green Energy (OSTI)

The activities in this task are designed to evaluate experimentally the performance of the gasification catalysts chosen for the system study in the first year of this effort. The objectives of this task have been broken down as follows: To experimentally characterize the performance of the previously recommended gasification catalysts for integrates gasification carbonate fuel cell systems as identified in the system study performed during Tasks 1, 2, and 3. The catalysts which will be tested include Potassium carbonates. limestone and taconite in dry form as well as a coal-impregnated with soluble salts of potassium, calcium and iron. To evaluate the degree to which SO{sub 2} in a recycled stream, and or sulfur in the feed, can be captured by the selected calcium or iron containing catalyst at the operation conditions in the catalytic gasifier. To carry out tests under simulated conditions approaching the preferred final process design conditions identified in the system study. The first phase of experimental testing consists of a cost-effective minimum scale screening by Thermogravimetric Analysis (TGA).

Steinfeld, G.

1992-12-31T23:59:59.000Z

372

Performance comparison between partial oxidation and methane steam reforming processes for solid oxide fuel cell (SOFC) micro combined heat and  

E-Print Network (OSTI)

Performance comparison between partial oxidation and methane steam reforming processes for solid recirculation are used along with steam methane reforming. Further Steam Methane Reforming process produces Cell fueled by natural gas with two different types of pre-reforming systems, namely Steam Reforming

Liso, Vincenzo

373

Study on the Performance and Exhaust Emissions of Motorcycle Engine Fuelled with Hydrogen-Gasoline Compound Fuel  

Science Conference Proceedings (OSTI)

The motorcycle plays an important role in the life for the people of Taiwan. However, the motorcycles' emissions are the main moving air pollution sources. Therefore, it's important to develop more efficient combustion technology in order to save energy ... Keywords: Emissions, Emissions Pollution, Hydrogen-Gasoline Compound Fuel, Performance Test, Solid State Hydrogen Storage

Chang-Huei Lin; Li-Ming Chu; Hsiang-Chen Hsu

2012-07-01T23:59:59.000Z

374

CHF Performance of Hybrid Mixing Vane Grid for a Nuclear Fuel Bundle  

SciTech Connect

Numerous studies have shown that the mixing vanes of the spacer grids in a nuclear fuel rod bundle increase the Critical Heat Flux (CHF) significantly. The amount of the CHF enhancement depends strongly on the design of the mixing vanes such as the vane shape and vane bending angle. Recently a new mixing vane design was developed for an advanced spacer grid. It is called a Hybrid Mixing Vane. The main objective of this work is to evaluate the CHF performance of the hybrid vane grid and to compare it with that of a split vane grid. Three kinds of rod bundles were tested for the above objectives: no mixing vane grids, the hybrid mixing vane grids, and the split mixing vane grids. To measure the CHF data, 5x5 rod bundle experiments were conducted in the FTHEL (Freon Thermal Hydraulic Experiment Loop). Each experiment was performed by maintaining the following system conditions as constant: inlet pressure, inlet temperature, and mass flow rate. The experiments were performed in ranges of the inlet pressure, P{sub in} = 2000{approx}3000 kPa, mass flux, G = 1000{approx}3000 kg/m{sup 2}s, and inlet subcooling, {delta}h{sub in}= 10{approx}55 kJ/kg, which simulates the PWR operating conditions for a water equivalence through a fluid-to-fluid modeling. The CHF performances were compared with the data belonging to a PWR's operating conditions; a pressure of 2000{approx}3000 kPa and a mass flux of 1500{approx}3000 kg/m{sup 2}s. The average of the CHF increase for the hybrid mixing grids for 20 data sets is 18.2% higher than that for the no vane grids. While the average of the CHF increase for the split mixing vane grids for 20 data sets is 14.5% higher than that for the no vane grids. Consequently, the CHF performance of the hybrid mixing vane grid is superior by about 4% to that of the split mixing vane grid near the normal PWR operating conditions even under a longer grid span than usual. (authors)

Shin, Chang-Hwan; Chun, Tae-Hyun [LWR Fuel Development Division, Korea Atomic Energy Research Institute, 150 Dukjin-dong, Yuseong, Daejeon, 305-353 (Korea, Republic of); Choo, Yeon-Jun; Moon, Sang-Ki; Chun, Se-Young [Thermal-Hydraulic Safety Research Division, Korea Atomic Energy Research Institute, 150 Dukjin-dong, Yuseong, Daejeon, 305-353 (Korea, Republic of)

2007-07-01T23:59:59.000Z

375

Regional refining models for alternative fuels using shale and coal synthetic crudes: identification and evaluation of optimized alternative fuels. Annual report, March 20, 1979-March 19, 1980  

DOE Green Energy (OSTI)

The initial phase has been completed in the project to evaluate alternative fuels for highway transportation from synthetic crudes. Three refinery models were developed for Rocky Mountain, Mid-Continent and Great Lakes regions to make future product volumes and qualities forecast for 1995. Projected quantities of shale oil and coal oil syncrudes were introduced into the raw materials slate. Product slate was then varied from conventional products to evaluate maximum diesel fuel and broadcut fuel in all regions. Gasoline supplement options were evaluated in one region for 10% each of methanol, ethanol, MTBE or synthetic naphtha in the blends along with syncrude components. Compositions and qualities of the fuels were determined for the variation in constraints and conditions established for the study. Effects on raw materials, energy consumption and investment costs were reported. Results provide the basis to formulate fuels for laboratory and engine evaluation in future phases of the project.

Sefer, N.R.; Russell, J.A.

1980-11-01T23:59:59.000Z

376

Performance of Sulfur Tolerant Reforming Catalysts for Production of Hydrogen from Jet Fuel Simulants  

E-Print Network (OSTI)

ReceiVed August 2, 2007 The development of robust desulfurizers and new reforming catalysts for fuel cells: the desulfurization of jet fuel and the development of sulfur-tolerant reforming catalysts/C) ratios. The water gas shift reaction is then used to convert additional CO into CO2. Nickel has been

Azad, Abdul-Majeed

377

Vehicle System Impacts of Fuel Cell System Power Response Capability  

NLE Websites -- All DOE Office Websites (Extended Search)

- 01 - 1959 - 01 - 1959 Vehicle System Impacts of Fuel Cell System Power Response Capability Tony Markel and Keith Wipke National Renewable Energy Laboratory Doug Nelson Virginia Polytechnic University and State Institute Copyright © 2002 Society of Automotive Engineers, Inc. ABSTRACT The impacts of fuel cell system power response capability on optimal hybrid and neat fuel cell vehicle configurations have been explored. Vehicle system optimization was performed with the goal of maximizing fuel economy over a drive cycle. Optimal hybrid vehicle design scenarios were derived for fuel cell systems with 10 to 90% power transient response times of 0, 2, 5, 10, 20, and 40 seconds. Optimal neat fuel cell vehicles where generated for responses times of 0, 2, 5, and 7

378

INVESTIGATION OF FUEL CHEMISTRY AND BED PERFORMANCE IN A FLUIDIZED BED BLACK LIQUOR STEAM REFORMER  

DOE Green Energy (OSTI)

The University of Utah project ''Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer'' (DOE award number DE-FC26-02NT41490) was developed in response to a solicitation for projects to provide technical support for black liquor and biomass gasification. The primary focus of the project is to provide support for a DOE-sponsored demonstration of MTCI's black liquor steam reforming technology at Georgia-Pacific's paper mill in Big Island, Virginia. A more overarching goal is to improve the understanding of phenomena that take place during low temperature black liquor gasification. This is achieved through five complementary technical tasks: (1) construction of a fluidized bed black liquor gasification test system, (2) investigation of bed performance, (3) evaluation of product gas quality, (4) black liquor conversion analysis and modeling and (5) computational modeling of the Big Island gasifier. Four experimental devices have been constructed under this project. The largest facility, which is the heart of the experimental effort, is a pressurized fluidized bed gasification test system. The system is designed to be able to reproduce conditions near the black liquor injectors in the Big Island steam reformer, so the behavior of black liquor pyrolysis and char gasification can be quantified in a representative environment. The gasification test system comprises five subsystems: steam generation and superheating, black liquor feed, fluidized bed reactor, afterburner for syngas combustion and a flue gas cooler/condenser. The three-story system is located at University of Utah's Industrial Combustion and Gasification Research Facility, and all resources there are available to support the research.

Kevin Whitty

2003-12-01T23:59:59.000Z

379

Analysis of the IFA-432, IFA-597, and IFA-597 MOX Fuel Performance Experiments by FRAPCON-3.4  

SciTech Connect

Validation of advanced nuclear fuel modeling tools requires careful comparison with reliable experimental benchmark data. A comparison to industry-accepted codes, that are well characterized, and regulatory codes is also a useful evaluation tool. In this report, an independent validation of the FRAPCON-3.4 fuel performance code is conducted with respect to three experimental benchmarks, IFA-432, IFA-597, and IFA-597mox. FRAPCON was found to most accurately model the mox rods, to within 2% of the experimental data, depending on the simulation parameters. The IFA-432 and IFA-597 rods were modeled with FRAPCON predicting centerline temperatures different, on average, by 21 percent.

Phillippe, Aaron M [ORNL; Ott, Larry J [ORNL; Clarno, Kevin T [ORNL; Banfield, James E [ORNL

2012-08-01T23:59:59.000Z

380

Chemical Kinetic Modeling of Advanced Transportation Fuels  

DOE Green Energy (OSTI)

Development of detailed chemical kinetic models for advanced petroleum-based and nonpetroleum based fuels is a difficult challenge because of the hundreds to thousands of different components in these fuels and because some of these fuels contain components that have not been considered in the past. It is important to develop detailed chemical kinetic models for these fuels since the models can be put into engine simulation codes used for optimizing engine design for maximum efficiency and minimal pollutant emissions. For example, these chemistry-enabled engine codes can be used to optimize combustion chamber shape and fuel injection timing. They also allow insight into how the composition of advanced petroleum-based and non-petroleum based fuels affect engine performance characteristics. Additionally, chemical kinetic models can be used separately to interpret important in-cylinder experimental data and gain insight into advanced engine combustion processes such as HCCI and lean burn engines. The objectives are: (1) Develop detailed chemical kinetic reaction models for components of advanced petroleum-based and non-petroleum based fuels. These fuels models include components from vegetable-oil-derived biodiesel, oil-sand derived fuel, alcohol fuels and other advanced bio-based and alternative fuels. (2) Develop detailed chemical kinetic reaction models for mixtures of non-petroleum and petroleum-based components to represent real fuels and lead to efficient reduced combustion models needed for engine modeling codes. (3) Characterize the role of fuel composition on efficiency and pollutant emissions from practical automotive engines.

PItz, W J; Westbrook, C K; Herbinet, O

2009-01-20T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Improved Gas Turbines for LBTU Syngas Fuel Operation  

Science Conference Proceedings (OSTI)

Gas turbine engines running on syngas can take advantage of that fuel's high mass flow per BTU. Optimizing performance while keeping all operating parameters within acceptable limits was the result of a G.E. project.

1997-01-03T23:59:59.000Z

382

Performance of Anode-Supported Solid Oxide Fuel Cell with Thin Bi-Layer Electrolyte by Pulsed Laser Deposition  

Science Conference Proceedings (OSTI)

Anode-supported yttria stabilized zirconia (YSZ)/samaria doped ceria (SDC) bi-layer electrolytes with uniform thickness and high density were fabricated by pulsed laser deposition at 1000 degrees C. Fuel cells with such bi-layer electrolytes were fabricated and tested, yielding open circuit voltages from 0.94 to 1.0 V at 600-700 degrees C. Power densities from 0.4 to 1.0 W cm{sup -2} at 0.7 V were achieved in air at temperatures of 600-700 degrees C. Cell performance was improved in flowing oxygen, with an estimated peak power density of over 2 W cm{sup -2} at 650 degrees C, assuming the same overall resistance over the entire range of current density. The high cell performance was attributed to the very low ohmic resistance of the fuel cell, owing to the small thickness of the electrolyte. Stable performance was also demonstrated in that the voltage of the fuel cell showed very little change at a constant current density of 1 A cm{sup -2} during more than 400 hours of operation at 650 degrees C in flowing oxygen. SEM analysis of the fuel cell after testing showed that the bi-layer electrolyte had retained its chemical and mechanical integrity.

Lu, Zigui; Hardy, John S.; Templeton, Jared W.; Stevenson, Jeffry W.; Fisher, Daniel; Wu, Naijuan; Ignatiev, Alex

2012-07-15T23:59:59.000Z

383

2005 DOE Hydrogen Program Review PresentationCOST AND PERFORMANCE ENHANCEMENTS FOR A PEM FUEL CELL TURBOCOMPRESSOR  

DOE Green Energy (OSTI)

The objectives of the program during the past year was to complete Technical Objectives 2 and 3 and initiate Technical Objective 4 are described. To assist the Department of Energy in the development of a low cost, reliable and high performance air compressor/expander. Technical Objective 1: Perform a turbocompressor systems PEM fuel cell trade study to determine the enhanced turbocompressor approach. Technical Objective 2: Using the results from technical objective 1, an enhanced turbocompressor will be fabricated. The design may be modified to match the flow requirements of a selected fuel cell system developer. Technical Objective 3: Design a cost and performance enhanced compact motor and motor controller. Technical Objective 4: Turbocompressor/motor controller development.

Mark K. Gee

2005-04-01T23:59:59.000Z

384

OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE--A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING  

Science Conference Proceedings (OSTI)

This document details the progress to date on the ''OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE--A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING'' contract for the quarter starting April 2004 through June 2004. The DOE and TerraTek continue to wait for Novatek on the optimization portion of the testing program (they are completely rebuilding their fluid hammer). The latest indication is that the Novatek tool would be ready for retesting only 4Q 2004 or later. Smith International's hammer was tested in April of 2004 (2Q 2004 report). Accomplishments included the following: (1) TerraTek re-tested the ''optimized'' fluid hammer provided by Smith International during April 2004. Many improvements in mud hammer rates of penetration were noted over Phase 1 benchmark testing from November 2002. (2) Shell Exploration and Production in The Hague was briefed on various drilling performance projects including Task 8 ''Cutter Impact Testing''. Shell interest and willingness to assist in the test matrix as an Industry Advisor is appreciated. (3) TerraTek participated in a DOE/NETL Review meeting at Morgantown on April 15, 2004. The discussions were very helpful and a program related to the Mud Hammer optimization project was noted--Terralog modeling work on percussion tools. (4) Terralog's Dr. Gang Han witnessed some of the full-scale optimization testing of the Smith International hammer in order to familiarize him with downhole tools. TerraTek recommends that modeling first start with single cutters/inserts and progress in complexity. (5) The final equipment problem on the impact testing task was resolved through the acquisition of a high data rate laser based displacement instrument. (6) TerraTek provided Novatek much engineering support for the future re-testing of their optimized tool. Work was conducted on slip ring [electrical] specifications and tool collar sealing in the testing vessel with a reconfigured flow system on Novatek's collar.

Arnis Judzis

2004-07-01T23:59:59.000Z

385

Method of optimizing performance of Rankine cycle power plants. [US DOE Patent  

DOE Patents (OSTI)

A method is described for efficiently operating a Rankine cycle power plant to maximize fuel utilization efficiency or energy conversion efficiency or minimize costs by selecting a turbine fluid inlet state which is substantially on the area adjacent and including the transposed critical temperature line.

Pope, W.L.; Pines, H.S.; Doyle, P.A.; Silvester, L.F.

1980-06-23T23:59:59.000Z

386

Effects of piston surface treatments on performance and emissions of a methanol-fueled, direct injection, stratified charge engine  

Science Conference Proceedings (OSTI)

The purpose of this study was to investigate the effects of thermal barrier coatings and/or surface treatments on the performance and emissions of a methanol-fueled, direct-injection, stratified-charge (DISC) engine. A Ricardo Hydra Mark III engine was used for this work and in previous experiments at Oak Ridge National Laboratory (ORNL). The primary focus of the study was to examine the effects of various piston insert surface treatments on hydrocarbon (HC) and oxides of nitrogen (NO{sub x}) emissions. Previous studies have shown that engines of this class have a tendency to perform poorly at low loads and have high unburned fuel emissions. A blank aluminum piston was modified to employ removable piston bowl inserts. Four different inserts were tested in the experiment: aluminum, stainless steel with a 1.27-mm (0.050-in.) air gap (to act as a thermal barrier), and two stainless steel/air-gap inserts with coatings. Two stainless steel inserts were dimensionally modified to account for the coating thickness (1.27-mm) and coated identically with partially stabilized zirconia (PSZ). One of the coated inserts then had an additional seal-coat applied. The coated inserts were otherwise identical to the stainless steel/air-gap insert (i.e., they employed the same 1.27-mm air gap). Thermal barrier coatings were employed in an attempt to increase combustion chamber surface temperatures, thereby reducing wall quenching and promoting more complete combustion of the fuel in the quench zone. The seal-coat was applied to the zirconia to reduce the surface porosity; previous research suggested that despite the possibly higher surface temperatures obtainable with a ceramic coating, the high surface area of a plasma-sprayed coating may actually allow fuel to adhere to the surface and increase the unburned fuel emissions and fuel consumption.

West, B.; Green, J.B. [Oak Ridge National Lab., TN (United States)

1994-07-01T23:59:59.000Z

387

OPTIMIZATION OF THE CATHODE LONG-TERM STABILITY IN MOLTEN CARBONATE FUEL CELLS: EXPERIMENTAL STUDY AND MATHEMATICAL MODELING  

DOE Green Energy (OSTI)

The dissolution of NiO cathodes during cell operation is a limiting factor to the successful commercialization of molten carbonate fuel cells (MCFCs). Lithium cobalt oxide coating onto the porous nickel electrode has been adopted to modify the conventional MCFC cathode which is believed to increase the stability of the cathodes in the carbonate melt. The material used for surface modification should possess thermodynamic stability in the molten carbonate and also should be electro catalytically active for MCFC reactions. Lithium Cobalt oxide was coated on Ni cathode by a sol-gel coating. The morphology and the LiCoO{sub 2} formation of LiCoO{sub 2} coated NiO was studied using scanning electron microscopy and X-Ray diffraction studies respectively. The electrochemical performance lithium cobalt oxide coated NiO cathodes were investigated with open circuit potential measurement and current-potential polarization studies. These results were compared to that of bare NiO. Dissolution of nickel into the molten carbonate melt was less in case of lithium cobalt oxide coated nickel cathodes. LiCoO{sub 2} coated on the surface prevents the dissolution of Ni in the melt and thereby stabilizes the cathode. Finally, lithium cobalt oxide coated nickel shows similar polarization characteristics as nickel oxide. Conventional theoretical models for the molten carbonate fuel cell cathode are based on the thin film agglomerate model. The principal deficiency of the agglomerate model, apart from the simplified pore structure assumed, is the lack of measured values for film thickness and agglomerate radius. Both these parameters cannot be estimated appropriately. Attempts to estimate the thickness of the film vary by two orders of magnitude. To avoid these problems a new three phase homogeneous model has been developed using the volume averaging technique. The model considers the potential and current variation in both liquid and solid phases. Using this approach, volume averaged concentrations of both gaseous and liquid phase reactants are obtained separately. The polarization characteristics of the electrode have been studied for different electrode parameters. The effect of different design parameters on the electrode performance has also been analyzed. Finally, the model has been used to analyze the impedance response of the MCFC cathode.

Dr. Ralph E. White; Dr. Branko N. Popov

2001-10-01T23:59:59.000Z

388

Trends and drivers of the performance : fuel economy tradeoff in new automobiles  

E-Print Network (OSTI)

Cars sold in the United States have steadily become more fuel-efficient since the 1970s, and assessments of emerging technologies demonstrate a significant potential for continued evolutionary improvements. However, historic ...

MacKenzie, Donald Warren

2009-01-01T23:59:59.000Z

389

Concrete Shield Performance of the VSC-17 Spent Nuclear Fuel Cask  

Science Conference Proceedings (OSTI)

The VSC-17 Spent Nuclear Fuel Storage Cask was surveyed for degradation of the concrete shield by radiation measurement, temperature measurement, and ultrasonic testing. No general loss of shielding function was identified.

Koji Shirai

2006-04-01T23:59:59.000Z

390

Predicting and Optimizing System Utilization and Performance via Statistical Machine Learning  

E-Print Network (OSTI)

5 Auto-tuning High Performance Computing Motifs on a5. Auto-tuning High Performance Computing Motifs on aChapter 4, and high performance computing code on multicore

Ganapathi, Archana

2009-01-01T23:59:59.000Z

391

High Performance Catalytic Heat Exchanger for SOFC Systems - FuelCell Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

Catalytic Heat Catalytic Heat Exchanger for SOFC Systems-FuelCell Energy Background In a typical solid oxide fuel cell (SOFC) power generation system, hot (~900 °C) effluent gas from a catalytic combustor serves as the heat source within a high-temperature heat exchanger, preheating incoming fresh air for the SOFC's cathode. The catalytic combustor and the cathode air heat exchanger together represent the largest opportunity for cost

392

Summary report on the fuel performance modeling of the AFC-2A, 2B irradiation experiments  

SciTech Connect

The primary objective of this work at the Idaho National Laboratory (INL) is to determine the fuel and cladding temperature history during irradiation of the AFC-2A, 2B transmutation metallic fuel alloy irradiation experiments containing transuranic and rare earth elements. Addition of the rare earth elements intends to simulate potential fission product carry-over from pyro-metallurgical reprocessing. Post irradiation examination of the AFC-2A, 2B rodlets revealed breaches in the rodlets and fuel melting which was attributed to the release of the fission gas into the helium gap between the rodlet cladding and the capsule which houses six individually encapsulated rodlets. This release is not anticipated during nominal operation of the AFC irradiation vehicle that features a double encapsulated design in which sodium bonded metallic fuel is separated from the ATR coolant by the cladding and the capsule walls. The modeling effort is focused on assessing effects of this unanticipated event on the fuel and cladding temperature with an objective to compare calculated results with the temperature limits of the fuel and the cladding.

Pavel G. Medvedev

2013-09-01T23:59:59.000Z

393

Production Cost Optimization Assessments  

Science Conference Proceedings (OSTI)

The benefits of improved thermal performance of coal-fired power plants continue to grow, as the costs of fuel rise and the prospect of a carbon dioxide cap and trade program looms on the horizon. This report summarizes the efforts to date of utilities committed to reducing their heat rate by 1.0% in the Production Cost Optimization (PCO) Project. The process includes benchmarking of plant thermal performance using existing plant data and a site-specific performance appraisal. The appraisal determines po...

2008-12-11T23:59:59.000Z

394

Preliminary Simulations for Geometric Optimization of a High-Energy Delayed Gamma Spectrometer for Direct Assay of Pu in Spent Nuclear Fuel  

Science Conference Proceedings (OSTI)

High-energy, beta-delayed gamma-ray spectroscopy is under investigation as part of the Next Generation Safeguard Initiative effort to develop non-destructive assay instruments for plutonium mass quantification in spent nuclear fuel assemblies. Results obtained to date indicate that individual isotope-specific signatures contained in the delayed gamma-ray spectra can potentially be used to quantify the total fissile content and individual weight fractions of fissile and fertile nuclides present in spent fuel. Adequate assay precision for inventory analysis can be obtained using a neutron generator of sufficient strength and currently available detection technology. In an attempt to optimize the geometric configuration and material composition for a delayed gamma measurement on spent fuel, the current study applies MCNPX, a Monte Carlo radiation transport code, in order to obtain the best signal-to-noise ratio. Results are presented for optimizing the neutron spectrum tailoring material, geometries to maximize thermal or fast fissions from a given neutron source, and detector location to allow an acceptable delayed gamma-ray signal while achieving a reasonable detector lifetime while operating in a high-energy neutron field. This work is supported in part by the Next Generation Safeguards Initiative, Office of Nuclear Safeguards and Security, National Nuclear Security Administration.

Kulisek, Jonathan A.; Campbell, Luke W.; Rodriguez, Douglas C.

2012-06-07T23:59:59.000Z

395

Solving combinatorial optimization problems using relaxed linear programming: a high performance computing perspective  

Science Conference Proceedings (OSTI)

Several important combinatorial optimization problems can be formulated as maximum a posteriori (MAP) inference in discrete graphical models. We adopt the recently proposed parallel MAP inference algorithm Bethe-ADMM and implement it using message passing ... Keywords: Markov random field, alternating direction method of multipliers, maximum a posteriori inference, message passing interface

Chen Jin; Qiang Fu; Huahua Wang; Ankit Agrawal; William Hendrix; Wei-keng Liao; Md. Mostofa Ali Patwary; Arindam Banerjee; Alok Choudhary

2013-08-01T23:59:59.000Z

396

Ecological Optimization Performance of An Irreversible Quantum Otto Cycle Working with an Ideal Fermi Gas  

Science Conference Proceedings (OSTI)

The model of an irreversible Otto cycle using an ideal Fermi gas as the working fluid, which is called as the irreversible Fermi Otto cycle, is established in this paper. Based on the equation of state of an ideal Fermi gas, the ecological optimization ...

Feng Wu; Lingen Chen; Fengrui Sun; Chih Wu; Fangzhong Guo; Qing Li

2006-03-01T23:59:59.000Z

397

OPTIMAL CONTROL OF PROJECTS BASED ON KALMAN FILTER APPROACH FOR TRACKING & FORECASTING THE PROJECT PERFORMANCE  

E-Print Network (OSTI)

Traditional scheduling tools like Gantt Charts and CPM while useful in planning and execution of complex construction projects with multiple interdependent activities haven?t been of much help in implementing effective control systems for the same projects in case of deviation from their desired or assumed behavior. Further, in case of such deviations project managers in most cases make decisions which might be guided either by the prospects of short term gains or the intension of forcing the project to follow the original schedule or plan, inadvertently increasing the overall project cost. Many deterministic project control methods have been proposed by various researchers for calculating optimal resource schedules considering the time-cost as well as the time-cost-quality trade-off analysis. But the need is for a project control system which optimizes the effort or cost required for controlling the project by incorporating the stochastic dynamic nature of the construction-production process. Further, such a system must include a method for updating and revising the beliefs or models used for representing the dynamics of the project using the actual progress data of the project. This research develops such an optimal project control method using Kalman Filter forecasting method for updating and using the assumed project dynamics model for forecasting the Estimated Cost at Completion (EAC) and the Estimated Duration at Completion (EDAC) taking into account the inherent uncertainties in the project progress and progress measurements. The controller is then formulated for iteratively calculating the optimal resource allocation schedule that minimizes either the EAC or both the EAC and EDAC together using the evolutionary optimization algorithm Covariance Matrix Adaption Evolution Strategy (CMA-ES). The implementation of the developed framework is used with a hypothetical project and tested for its robustness in updating the assumed initial project dynamics model and yielding the optimal control policy considering some hypothetical cases of uncertainties in the project progress and progress measurements. Based on the tests and demonstrations firstly it is concluded that a project dynamics model based on the project Gantt chart for spatial interdependencies of sub-tasks with triangular progress rates is a good representation of a typical construction project; and secondly, it is shown that the use of CMA-ES in conjunction with the Kalman Filter estimation and forecasting method provides a robust framework that can be implemented for any kind of complex construction process for yielding the optimal control policies.

Bondugula, Srikant

2009-05-01T23:59:59.000Z

398

OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE - A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING  

Science Conference Proceedings (OSTI)

This document details the progress to date on the OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE -- A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING contract for the quarter starting July 2001 through September 2001. Accomplishments to date include the following: TerraTek highlighted DOE's National Energy Technology Laboratory effort on Mud Hammer Optimization at the recent Annual Conference and Exhibition for the Society of Petroleum Engineers. The original exhibit scheduled by NETL was canceled due to events surrounding the September tragedies in the US. TerraTek has completed analysis of drilling performance (rates of penetration, hydraulics, etc.) for the Phase One testing which was completed at the beginning of July. TerraTek jointly with the Industry Advisory Board for this project and DOE/NETL conducted a lessons learned meeting to transfer technology vital for the next series of performance tests. Both hammer suppliers benefited from the testing program and are committed to pursue equipment improvements and ''optimization'' in accordance with the scope of work. An abstract for a proposed publication by the society of Petroleum Engineers/International Association of Drilling Contractors jointly sponsored Drilling Conference was accepted as an alternate paper. Technology transfer is encouraged by the DOE in this program, thus plans are underway to prepare the paper for this prestigious venue.

Gordon Tibbitts; Arnis Judzis

2001-10-01T23:59:59.000Z

399

Cost/performance comparison between pulse columns and centrifugal contactors designed to process Clinch River Breeder Reactor fuel  

Science Conference Proceedings (OSTI)

A comparison between pulse columns and centrifugal contactors was made to determine which type of equipment was more advantageous for use in the primary decontamination cycle of a remotely operated fuel reprocessing plant. Clinch River Breeder Reactor (CRBR) fuel was chosen as the fuel to be processed in the proposed 1 metric tonne/day reprocessing facility. The pulse columns and centrifugal contactors were compared on a performance and total cost basis. From this comparison, either the pulse columns or the centrifugal contactors will be recommended for use in a fuel reprocessing plant built to reprocess CRBR fuel. The reliability, solvent exposure to radiation, required time to reach steady state, and the total costs were the primary areas of concern for the comparison. The pulse column units were determined to be more reliable than the centrifugal contactors. When a centrifugal contactor motor fails, it can be remotely changed in less than one eight hour shift. Pulse columns expose the solvent to approximately five times as much radiation dose as the centrifugal contactor units; however, the proposed solvent recovery system adequately cleans the solvent for either case. The time required for pulse columns to reach steady state is many times longer than the time required for centrifugal contactors to reach steady state. The cost comparison between the two types of contacting equipment resulted in centrifugal contactors costing 85% of the total cost of pulse columns when the contactors were stacked on three levels in the module. If the centrifugal contactors were all positioned on the top level of a module with the unoccupied volume in the module occupied by other equipment, the centrifugal contactors cost is 66% of the total cost of pulse columns. Based on these results, centrifugal contactors are recommended for use in a remotely operated reprocessing plant built to reprocess CRBR fuel.

Ciucci, J.A. Jr.

1983-12-01T23:59:59.000Z

400

Fossil fuels -- future fuels  

Science Conference Proceedings (OSTI)

Fossil fuels -- coal, oil, and natural gas -- built America`s historic economic strength. Today, coal supplies more than 55% of the electricity, oil more than 97% of the transportation needs, and natural gas 24% of the primary energy used in the US. Even taking into account increased use of renewable fuels and vastly improved powerplant efficiencies, 90% of national energy needs will still be met by fossil fuels in 2020. If advanced technologies that boost efficiency and environmental performance can be successfully developed and deployed, the US can continue to depend upon its rich resources of fossil fuels.

NONE

1998-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal fuel performance" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

MATERIAL AND PROCESS DEVELOPMENT LEADING TO ECONOMICAL HIGH-PERFORMANCE THIN-FILM SOLID OXIDE FUEL CELLS  

DOE Green Energy (OSTI)

This report summarizes the results of the work conducted under the program: ''Material and Process Development Leading to Economical High-Performance Thin-Film Solid Oxide Fuel Cells'' under contract number DE-AC26-00NT40711. The program goal is to advance materials and processes that can be used to produce economical, high-performance solid oxide fuel cells (SOFC) capable of achieving extraordinary high power densities at reduced temperatures. Under this program, anode-supported thin electrolyte based on lanthanum gallate (LSMGF) has been developed using tape-calendering process. The fabrication parameters such as raw materials characteristics, tape formulations and sintering conditions have been evaluated. Dense anode supported LSGMF electrolytes with thickness range of 10-50 micron have been fabricated. High performance cathode based on Sr{sub 0.5}Sm{sub 0.5}CoO{sub 3} (SSC) has been developed. Polarization of {approx}0.23 ohm-cm{sup 2} has been achieved at 600 C with Sr{sub 0.5}Sm{sub 0.5}CoO{sub 3}cathode. The high-performance SSC cathode and thin gallate electrolyte have been integrated into single cells and cell performance has been characterized. Tested cells to date generally showed low performance because of low cell OCVs and material interactions between NiO in the anode and lanthanum gallate electrolyte.

Jie Guan; Nguyen Minh

2003-12-01T23:59:59.000Z

402

OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE - A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING  

Science Conference Proceedings (OSTI)

This document details the progress to date on the ''OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE--A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING'' contract for the quarter starting April 2003 through June 2003. The DOE and TerraTek continue to wait for Novatek on the optimization portion of the testing program (they are completely rebuilding their fluid hammer). Accomplishments included the following: (1) Hughes Christensen has recently expressed interest in the possibility of a program to examine cutter impact testing, which would be useful in a better understanding of the physics of rock impact. Their interest however is not necessarily fluid hammers, but to use the information for drilling bit development. (2) Novatek (cost sharing supplier of tools) has informed the DOE project manager that their tool may not be ready for ''optimization'' testing late summer 2003 (August-September timeframe) as originally anticipated. During 3Q Novatek plans to meet with TerraTek to discuss progress with their tool for 4Q 2003 testing. (3) A task for an addendum to the hammer project related to cutter impact studies was written during 2Q 2003. (4) Smith International internally is upgrading their hammer for the optimization testing phase. One currently known area of improvement is their development program to significantly increase the hammer blow energy.

Arnis Judzis

2003-07-01T23:59:59.000Z

403

Performance monitoring for new phase dynamic optimization of instruction dispatch cluster configuration  

DOE Patents (OSTI)

In a processor having multiple clusters which operate in parallel, the number of clusters in use can be varied dynamically. At the start of each program phase, the configuration option for an interval is run to determine the optimal configuration, which is used until the next phase change is detected. The optimum instruction interval is determined by starting with a minimum interval and doubling it until a low stability factor is reached.

Balasubramonian, Rajeev (Sandy, UT); Dwarkadas, Sandhya (Rochester, NY); Albonesi, David (Ithaca, NY)

2012-01-24T23:59:59.000Z

404

OPTIMIZATION OF THE CATHODE LONG-TERM STABILITY IN MOLTEN CARBONATE FUEL CELLS: EXPERIMENTAL STUDY AND MATHEMATICAL MODELING  

DOE Green Energy (OSTI)

The dissolution of NiO cathodes during cell operation is a limiting factor to the successful commercialization of molten carbonate fuel cells (MCFCs). Microencapsulation of the NiO cathode has been adopted as a surface modification technique to increase the stability of NiO cathodes in the carbonate melt. The material used for surface modification should possess thermodynamic stability in the molten carbonate and also should be electro catalytically active for MCFC reactions. A simple first principles model was developed to understand the influence of exchange current density and conductivity of the electrode material on the polarization of MCFC cathodes. The model predictions suggest that cobalt can be used to improve the corrosion resistance of NiO cathode without affecting its performance. Cobalt was deposited on NiO cathode by electroless deposition. The morphology and thermal oxidation behavior of Co coated NiO was studied using scanning electron microscopy and thermal gravimetric analysis respectively. The electrochemical performance of cobalt encapsulated NiO cathodes were investigated with open circuit potential measurement and current-potential polarization studies. These results were compared to that of bare NiO. The electrochemical oxidation behavior of cobalt-coated electrodes is similar to that of the bare NiO cathode. Dissolution of nickel into the molten carbonate melt was less in case of cobalt encapsulated nickel cathodes. Co coated on the surface prevents the dissolution of Ni in the melt and thereby stabilizes the cathode. Finally, cobalt coated nickel shows similar polarization characteristics as nickel oxide. A similar surface modification technique has been used to improve the performance of the SS 304 current collectors used in MCFC cells. SS 304 was encapsulated with nanostructured layers of NiCo and NiMo by electroless deposition. The corrosion behavior of bare and surface modified SS 304 in molten carbonate under cathode gas atmosphere was investigated with cyclic voltammetry, open circuit potential studies, Tafel polarization, impedance analysis and atomic absorption spectroscopy. This study confirms that the presence of surface modification leads to the formation of complex scales with better barrier properties and electronic conductivity.

Dr. Ralph E. White

2000-09-30T23:59:59.000Z

405

Long-life high performance fuel cell program. Interim Report, 28 May 1981-31 October 1984  

SciTech Connect

A multihundred kilowatt Regenerative Fuel Cell for use in a space station is envisioned. Three 0.508 sq ft (471.9 cm) active area multicell stacks were assembled and endurance tested. The long term performance stability of the platinum on carbon catalyst configuration suitability of the lightweight graphite electrolyte reservoir plate, the stability of the free standing butyl bonded potassium titanate matrix structure, and the long life potential of a hybrid polysulfone cell edge frame construction were demonstrated. A 18,000 hour demonstration test of multicell stack to a continuous cyclical load profile was conducted. A total of 12,000 cycles was completed, confirming the ability of the alkaline fuel cell to operate to a load profile simulating Regenerative Fuel Cell operation. An orbiter production hydrogen recirculation pump employed in support of the cyclical load profile test completed 13,000 hours of maintenance free operation. Laboratory endurance tests demonstrated the suitability of the butyl bonded potassium matrix, perforated nickel foil electrode substrates, and carbon ribbed substrate anode for use in the alkaline fuel cell. Corrosion testing of materials at 250 F (121.1 C) in 42% wgt. potassium identified ceria, zirconia, strontium titanate, strontium zirconate and lithium cobaltate as candidate matrix materials.

Martin, R.E.

1985-02-01T23:59:59.000Z

406

Effect of Creep of Ferritic Interconnect on Long-Term Performance of Solid Oxide Fuel Cell Stacks  

Science Conference Proceedings (OSTI)

High-temperature ferritic alloys are potential candidates as interconnect (IC) materials and spacers due to their low cost and coefficient of thermal expansion (CTE) compatibility with other components for most of the solid oxide fuel cells (SOFCs) . However, creep deformation becomes relevant for a material when the operating temperature exceeds or even is less than half of its melting temperature (in degrees of Kelvin). The operating temperatures for most of the SOFCs under development are around 1,073 K. With around 1,800 K of the melting temperature for most stainless steel, possible creep deformation of ferritic IC under the typical cell operating temperature should not be neglected. In this paper, the effects of IC creep behavior on stack geometry change and the stress redistribution of different cell components are predicted and summarized. The goal of the study is to investigate the performance of the fuel cell stack by obtaining the changes in fuel- and air-channel geometry due to creep of the ferritic stainless steel IC, therefore indicating possible changes in SOFC performance under long-term operations. The ferritic IC creep model was incorporated into software SOFC-MP and Mentat-FC, and finite element analyses were performed to quantify the deformed configuration of the SOFC stack under the long-term steady-state operating temperature. It was found that the creep behavior of the ferritic stainless steel IC contributes to narrowing of both the fuel- and the air-flow channels. In addition, stress re-distribution of the cell components suggests the need for a compliant sealing material that also relaxes at operating temperature.

Liu, Wenning N.; Sun, Xin; Khaleel, Mohammad A.

2010-08-01T23:59:59.000Z

407

OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE--A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING  

Science Conference Proceedings (OSTI)

This document details the progress to date on the OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE--A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING contract for the quarter starting January 2004 through March 2004. The DOE and TerraTek continue to wait for Novatek on the optimization portion of the testing program (they are completely rebuilding their fluid hammer). The latest indication is that the Novatek tool would be ready for retesting only 3Q 2004. Smith International's hammer will be tested in April of 2004 (2Q 2004 report). Accomplishments included the following: (1) TerraTek presented a paper for publication in conjunction with a peer review at the GTI Natural Gas Technologies Conference February 10, 2004. Manuscripts and associated presentation material were delivered on schedule. The paper was entitled ''Mud Hammer Performance Optimization''. (2) Shell Exploration and Production continued to express high interest in the ''cutter impact'' testing program Task 8. Hughes Christensen supplied inserts for this testing program. (3) TerraTek hosted an Industry/DOE planning meeting to finalize a testing program for ''Cutter Impact Testing--Understanding Rock Breakage with Bits'' on February 13, 2004. (4) Formal dialogue with Terralog was initiated. Terralog has recently been awarded a DOE contract to model hammer mechanics with TerraTek as a sub-contractor. (5) Novatek provided the DOE with a schedule to complete their new fluid hammer and test it at TerraTek.

Arnis Judzis

2004-04-01T23:59:59.000Z

408

International Workshop on Characterization and PIE Needs for Fundamental Understanding of Fuels Performance and Safety  

SciTech Connect

The International Workshop on Characterization and PIE Needs to Support Science-Based Development of Innovative Fuels was held June 16-17, 2011, in Paris, France. The Organization for Economic Co-operation and Development (OECD), Nuclear Energy Agency (NEA) Working Party on the Fuel Cycle (WPFC) sponsored the workshop to identify gaps in global capabilities that need to be filled to meet projected needs in the 21st century. First and foremost, the workshop brought nine countries and associated international organizations, together in support of common needs for nuclear fuels and materials testing, characterization, PIE, and modeling capabilities. Finland, France, Germany, Republic of Korea, Russian Federation, Sweden, Switzerland, United Kingdom, United States of America, IAEA, and ITU (on behalf of European Union Joint Research Centers) discussed issues and opportunities for future technical advancements and collaborations. Second, the presentations provided a base level of understanding of current international capabilities. Three main categories were covered: (1) status of facilities and near term plans, (2) PIE needs from fuels engineering and material science perspectives, and (3) novel PIE techniques being developed to meet the needs. The International presentations provided valuable data consistent with the outcome of the National Workshop held in March 2011. Finally, the panel discussion on 21st century PIE capabilities, created a unified approach for future collaborations. In conclusion, (1) existing capabilities are not sufficient to meet the needs of a science-based approach, (2) safety issues and fuels behavior during abnormal conditions will receive more focus post-Fukushima; therefore we need to adopt our techniques to those issues, and (3) International collaboration is needed in the areas of codes and standards development for the new techniques.

Not Listed

2011-12-01T23:59:59.000Z

409

Design and Performance of a Low Btu Fuel Rich-Quench-Lean Gas Turbine Combustor  

SciTech Connect

General Electric Company is developing gas turbines and a high temperature desulfurization system for use in integrated gasification combined cycle (IGCC) power plants. High temperature desulfurization, or hot gas cleanup (HGCU), offers many advantages over conventional low temperature desulfurization processes, but does not reduce the relatively high concentrations of fuel bound nitrogen (FBN) that are typically found in low Btu fuel. When fuels containing bound nitrogen are burned in conventional gas turbine combustors, a significant portion of the FBN is converted to NO{sub x}. Methods of reducing the NO{sub x} emissions from IGCC power plants equipped with HGCU are needed. Rich-quench-lean (RQL) combustion can decrease the conversion of FBN to NO{sub x} because a large fraction of the FBN is converted into non-reactive N{sub 2} in a fuel rich stage. Additional air, required for complete combustion, is added in a quench stage. A lean stage provides sufficient residence time for complete combustion. Objectives General Electric has developed and tested a rich-quench-lean gas turbine combustor for use with low Btu fuels containing FBN. The objective of this work has been to design an RQL combustor that has a lower conversion of FBN to N{sub x} than a conventional low Btu combustor and is suitable for use in a GE heavy duty gas turbine. Such a combustor must be of appropriate size and scale, configuration (can-annular), and capable of reaching ``F`` class firing conditions (combustor exit temperature = 2550{degrees}F).

Feitelberg, A.S.; Jackson, M.R.; Lacey, M.A.; Manning, K.S.; Ritter, A.M.

1996-12-31T23:59:59.000Z

410

Transmutation Dynamics: Impacts of Multi-Recycling on Fuel Cycle Performances  

SciTech Connect

From a physics standpoint, it is feasible to sustain continuous multi-recycle in either thermal or fast reactors. In Fiscal Year 2009, transmutaton work at INL provided important new insight, caveats, and tools on multi-recycle. Multi-recycle of MOX, even with all the transuranics, is possible provided continuous enrichment of the uranium phase to ~6.5% and also limitting the transuranic enrichment to slightly less than 8%. Multi-recycle of heterogeneous-IMF assemblies is possible with continuous enrichment of the UOX pins to ~4.95% and having =60 of the 264 fuel pins being inter-matrix. A new tool enables quick assessment of the impact of different cooling times on isotopic evolution. The effect of cooling time was found to be almost as controlling on higher mass actinide concentrations in fuel as the selection of thermal versus fast neutron spectra. A new dataset was built which provides on-the-fly estimates of gamma and neutron dose in MOX fuels as a function of the isotopic evolution. All studies this year focused on the impact of dynamic feedback due to choices made in option space. Both the equilibrium fuel cycle concentrations and the transient time to reach equilibrium for each isotope were evaluated over a range of reactor, reprocessing and cooling time combinations. New bounding cases and analysis methods for evaluating both reactor safety and radiation worker safety were established. This holistic collection of physics analyses and methods gives improved resolution of fuel cycle options, and impacts thereof, over that of previous ad-hoc and single-point analyses.

S. Bays; S. Piet; M. Pope; G. Youinou; A. Dumontier; D. Hawn

2009-09-01T23:59:59.000Z

411

Enlarging the Potential Market for Stationary Fuel Cells Through System Design Optimization - DOE Hydrogen and Fuel Cells Program FY 2012 Annual Progress Report  

NLE Websites -- All DOE Office Websites (Extended Search)

7 7 FY 2012 Annual Progress Report DOE Hydrogen and Fuel Cells Program Chris Ainscough (Primary Contact), Sam Sprik, Michael Penev National Renewable Energy Laboratory (NREL) 15013 Denver West Parkway Golden, CO 80401-3305 Phone: (303) 275-3781 Email: chris.ainscough@nrel.gov DOE Manager HQ: Kathi Epping Martin Phone: (202) 586-7425 Email: Kathi.Epping@ee.doe.gov Subcontractor: University of California Irvine, Irvine, CA (planned) Project Start Date: January 1, 2011 Project End Date: Project continuation and direction determined annually by DOE Fiscal Year (FY) 2012 Objectives Develop a complete stationary fuel cell model user's * guide including: Operational details on the model with guidance on - appropriate inputs. Documentation of control strategy algorithms. -

412

Model-driven Memory Optimizations for High Performance Computing: From Caches to I/o.  

E-Print Network (OSTI)

??High performance systems are quickly evolving to keep pace with application demands, and we observe greater complexity in system design at all scales. Parallelism, in (more)

Frasca, Michael

2012-01-01T23:59:59.000Z

413

Performance Calculations and Optimization of a Fresnel Direct Steam Generation CSP Plant with Heat Storage.  

E-Print Network (OSTI)

?? This master thesis deals with the performance calculations of a 9MW linear Fresnel CSP plant withdirect steam generation built by the Solar Division of (more)

Schlaifer, Perrine

2013-01-01T23:59:59.000Z

414

Review: Multi-objective based on parallel vector evaluated particle swarm optimization for optimal steady-state performance of power systems  

Science Conference Proceedings (OSTI)

In this paper the state-of-the-art extended particle swarm optimization (PSO) methods for solving multi-objective optimization problems are represented. We emphasize in those, the co-evolution technique of the parallel vector evaluated PSO (VEPSO), analysed ... Keywords: Multi-objective optimization, Parallel VEPSO, Reactive power control

John G. Vlachogiannis; Kwang Y. Lee

2009-10-01T23:59:59.000Z

415

Workflow-based resource allocation to optimize overall performance of composite services  

Science Conference Proceedings (OSTI)

In software service provision, the overall performance of a composite service is often the ultimate focus of concern rather than those of its individual components. This opens new opportunities for resource allocation because with its service workflow ... Keywords: Composite service, Performance, Resource allocation, Service oriented architecture

BangYu Wu; Chi-Hung Chi; Zhe Chen; Ming Gu; JiaGuang Sun

2009-03-01T23:59:59.000Z

416

Statistical Power and Performance Modeling for Optimizing the Energy Efficiency of Scientific Computing  

Science Conference Proceedings (OSTI)

High-performance computing (HPC) has become an indispensable resource in science and engineering, and it has oftentimes been referred to as the "thirdpillar" of science, along with theory and experimentation. Performance tuning is a key aspect in utilizing ... Keywords: energy-efficiency tuning, green supercomputing, regression modeling

Balaji Subramaniam; Wu-chun Feng

2010-12-01T23:59:59.000Z

417

Optimization of Mud Hammer Drilling Performance--A Program to Benchmark the Viability of Advanced Mud Hammer Drilling  

Science Conference Proceedings (OSTI)

Operators continue to look for ways to improve hard rock drilling performance through emerging technologies. A consortium of Department of Energy, operator and industry participants put together an effort to test and optimize mud driven fluid hammers as one emerging technology that has shown promise to increase penetration rates in hard rock. The thrust of this program has been to test and record the performance of fluid hammers in full scale test conditions including, hard formations at simulated depth, high density/high solids drilling muds, and realistic fluid power levels. This paper details the testing and results of testing two 7 3/4 inch diameter mud hammers with 8 1/2 inch hammer bits. A Novatek MHN5 and an SDS Digger FH185 mud hammer were tested with several bit types, with performance being compared to a conventional (IADC Code 537) tricone bit. These tools functionally operated in all of the simulated downhole environments. The performance was in the range of the baseline ticone or better at lower borehole pressures, but at higher borehole pressures the performance was in the lower range or below that of the baseline tricone bit. A new drilling mode was observed, while operating the MHN5 mud hammer. This mode was noticed as the weight on bit (WOB) was in transition from low to high applied load. During this new ''transition drilling mode'', performance was substantially improved and in some cases outperformed the tricone bit. Improvements were noted for the SDS tool while drilling with a more aggressive bit design. Future work includes the optimization of these or the next generation tools for operating in higher density and higher borehole pressure conditions and improving bit design and technology based on the knowledge gained from this test program.

Arnis Judzis

2006-03-01T23:59:59.000Z

418

Evaluation of the Field Performance of Residential Fuel Cells: Final Report  

DOE Green Energy (OSTI)

Distributed generation has attracted significant interest from rural electric cooperatives and their customers. Cooperatives have a particular nexus because of inherently low customer density, growth patterns at the end of long lines, and an influx of customers and high-tech industries seeking to diversify out of urban environments. Fuel cells are considered a particularly interesting DG candidate for these cooperatives because of their power quality, efficiency, and environmental benefits. The National Rural Electric Cooperative Association Cooperative Research Network residential fuel cell program demonstrated RFC power plants and assessed related technical and application issues. This final subcontract