WorldWideScience

Sample records for temperature gas cleanup

  1. Facilitated transport ceramic membranes for high-temperature gas cleanup. Final report, February 1990--April 1994

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, R.; Minford, E.; Damle, A.S.; Gangwal, S.K.; Hart, B.A.

    1994-04-01

    The objective of this program was to demonstrate the feasibility of developing high temperature, high pressure, facilitated transport ceramic membranes to control gaseous contaminants in Integrated Gasification Combined Cycle (IGCC) power generation systems. Meeting this objective requires that the contaminant gas H{sub 2}S be removed from an IGCC gas mixture without a substantial loss of the other gaseous components, specifically H{sub 2} and CH{sub 4}. As described above this requires consideration of other, nonconventional types of membranes. The solution evaluated in this program involved the use of facilitated transport membranes consisting of molten mixtures of alkali and alkaline earth carbonate salts immobilized in a microporous ceramic support. To accomplish this objective, Air Products and Chemicals, Inc., Golden Technologies Company Inc., and Research Triangle Institute worked together to develop and test high temperature facilitated membranes for the removal of H{sub 2}S from IGCC gas mixtures. Three basic experimental activities were pursued: (1) evaluation of the H{sub 2}S chemistry of a variety of alkali and alkaline earth carbonate salt mixtures; (2) development of microporous ceramic materials which were chemically and physically compatible with molten carbonate salt mixtures under IGCC conditions and which could function as a host to support a molten carbonate mixture and; (3) fabrication of molten carbonate/ceramic immobilized liquid membranes and evaluation of these membranes under conditions approximating those found in the intended application. Results of these activities are presented.

  2. Particulate hot gas stream cleanup technical issues

    Energy Technology Data Exchange (ETDEWEB)

    Pontius, D.H.; Snyder, T.R.

    1999-09-30

    The analyses of hot gas stream cleanup particulate samples and descriptions of filter performance studied under this contract were designed to address problems with filter operation that have been linked to characteristics of the collected particulate matter. One objective of this work was to generate an interactive, computerized data bank of the key physical and chemical characteristics of ash and char collected from operating advanced particle filters and to relate these characteristics to the operation and performance of these filters. The interactive data bank summarizes analyses of over 160 ash and char samples from fifteen pressurized fluidized-bed combustion and gasification facilities utilizing high-temperature, high pressure barrier filters.

  3. Comments on "Proposal for a Regenerative High-Temperature Process for Coal Gas Cleanup with Calcined Limestone"

    Czech Academy of Sciences Publication Activity Database

    Hartman, Miloslav; Trnka, Otakar

    2002-01-01

    Roč. 41, č. 24 (2002), s. 6207-6208 ISSN 0888-5885 R&D Projects: GA ČR GA203/98/0101; GA AV ČR IAA4072711 Keywords : H2S removal * coal gas * limestone Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.247, year: 2002

  4. Particulate hot gas stream cleanup technical issues

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    This is the tenth in a series of quarterly reports describing the activities performed under Contract No. DE-AC21-94MC31160. Analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic bed filter elements. Task I is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFS) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis of ceramic filter elements. Under Task I during the past quarter, analyses were performed on a particulate sample from the Transport Reactor Demonstration Unit (TRDU) located at the University of North Dakota Energy and Environmental Research Center. Analyses are in progress on ash samples from the Advanced Particulate Filter (APF) at the Pressurized Fluidized-Bed Combustor (PFBC) that was in operation at Tidd and ash samples from the Pressurized Circulating Fluid Bed (PCFB) system located at Karhula, Finland. A site visit was made to the Power Systems Development Facility (PSDF) to collect ash samples from the filter vessel and to document the condition of the filter vessel with still photographs and videotape. Particulate samples obtained during this visit are currently being analyzed for entry into the Hot Gas Cleanup (HGCU) data base. Preparations are being made for a review meeting on ash bridging to be held at Department of Energy Federal Energy Technology Center - Morgantown (DOE/FETC-MGN) in the near future. Most work on Task 2 was on hold pending receipt of additional funds; however, creep testing of Schumacher FT20 continued. The creep tests on Schumacher FT20 specimens just recently ended and data analysis and comparisons to other data are ongoing. A summary and analysis of these creep results will be sent out shortly. Creep

  5. Biomass gasification hot gas cleanup for power generation

    Energy Technology Data Exchange (ETDEWEB)

    Wiant, B.C.; Bachovchin, D.M. [Westinghouse Electric Corp., Orlando, FL (United States); Carty, R.H.; Onischak, M. [Institute of Gas Technology, Chicago, IL (United States); Horazak, D.A. [Gilbert/Commonwealth, Reading, PA (United States); Ruel, R.H. [The Pacific International Center for High Technology Research, Honolulu, HI (United States)

    1993-12-31

    In support of the US Department of Energy`s Biomass Power Program, a Westinghouse Electric led team consisting of the Institute of Gas Technology (IGT), Gilbert/Commonwealth (G/C), and the Pacific International Center for High Technology Research (PICHTR), is conducting a 30 month research and development program. The program will provide validation of hot gas cleanup technology with a pressurized fluidized bed, air-blown, biomass gasifier for operation of a gas turbine. This paper discusses the gasification and hot gas cleanup processes, scope of work and approach, and the program`s status.

  6. Particulate hot gas stream cleanup technical issues

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    This is the eleventh in a series of quarterly reports describing the activities performed under Contract No. DE-AC21-94MC31160. Analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic bed filter elements. Task 1 is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFS) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis of ceramic filter elements. Under Task 1 during the past quarter, analyses were completed on samples obtained during a site visit to the Power Systems Development Facility (PSDF). Analyses are in progress on ash samples from the Advanced Particulate Filter (APF) at the Pressurized Fluidized-Bed Combustor (PFBC) that was in operation at Tidd and ash samples from the Pressurized Circulating Fluid Bed (PCFB) system located at Karhula, Finland. An additional analysis was performed on a particulate sample from the Transport Reactor Demonstration Unit (TRDU) located at the University of North Dakota Energy and Environmental Research Center. A manuscript and poster were prepared for presentation at the Advanced Coal-Based Power and Environmental Systems `97 Conference scheduled for July 22 - 24, 1997. A summary of recent project work covering the mechanisms responsible for ash deposit consolidation and ash bridging in APF`s collecting PFB ash was prepared and presented at FETC-MGN in early July. The material presented at that meeting is included in the manuscript prepared for the Contractor`s Conference and also in this report. Task 2 work during the past quarter included mechanical testing and microstructural examination of Schumacher FT20 and Pall 326 as- manufactured, after 540 hr in service at Karhula, and after 1166 hr in service at

  7. Dynamic simulation for hot gas cleanup

    Energy Technology Data Exchange (ETDEWEB)

    Zeppi, C.; Berg, H.; Vitolo, S.; Tartarelli, R.; Tonini, D.; Zaccagnini, M. (ENEL CRTN, Pisa (Italy))

    1993-01-01

    Removal of sulfur compounds from hot coal gas is a necessary step during power generation operations. Metal oxides such as zinc ferrite, zinc titanate and tin oxide have been identified as promising adsorbent materials. A mathematical model capable of describing the sulfidation phase in fixed-, moving- and fluidized-bed reactors has been developed. Equations selected are sufficiently simple and numerical solutions can be obtained in a reasonable time using available computer equipment. At the same time the equations produce satisfactory agreement with experimental results. This paper presents kinetic models of spherical sorbent-particles applicable to all reactor configurations and a mathematical model limited to the moving-bed reactor. 10 refs., 5 figs.

  8. Biomass Gas Cleanup Using a Therminator

    Energy Technology Data Exchange (ETDEWEB)

    Dayton, David C; Kataria, Atish; Gupta, Rabhubir

    2012-03-06

    The objective of the project is to develop and demonstrate a novel fluidized-bed process module called a Therminator to simultaneously destroy and/or remove tar, NH3 and H2S from raw syngas produced by a fluidized-bed biomass gasifier. The raw syngas contains as much as 10 g/m3 of tar, 4,000 ppmv of NH3 and 100 ppmv of H2S. The goal of the Therminator module would be to use promising regenerable catalysts developed for removing tar, ammonia, and H2S down to low levels (around 10 ppm). Tars are cracked to a non-condensable gas and coke that would deposit on the acid catalyst. We will deposit coke, much like a fluid catalytic cracker (FCC) in a petroleum refinery. The deposited coke fouls the catalyst, much like FCC, but the coke would be burned off in the regenerator and the regenerated catalyst would be returned to the cracker. The rapid circulation between the cracker and regenerator would ensure the availability of the required amount of regenerated catalyst to accomplish our goal. Also, by removing sulfur down to less than 10 ppmv, NH3 decomposition would also be possible in the cracker at 600-700°C. In the cracker, tar decomposes and lays down coke on the acid sites of the catalyst, NH3 is decomposed using a small amount of metal (e.g., nickel or iron) catalyst incorporated into the catalyst matrix, and H2S is removed by a small amount of a metal oxide (e.g. zinc oxide or zinc titanate) by the H2S-metal oxide reaction to form metal sulfide. After a tolerable decline in activity for these reactions, the catalyst particles (and additives) are transported to the regenerator where they are exposed to air to remove the coke and to regenerate the metal sulfide back to metal oxide. Sulfate formation is avoided by running the regeneration with slightly sub-stoichiometric quantity of oxygen. Following regeneration, the catalyst is transported back to the cracker and the cycling continues. Analogous to an FCC reactor system, rapid cycling will allow the use of very

  9. Efficiency enhancement in IGCC power plants with air-blown gasification and hot gas clean-up

    International Nuclear Information System (INIS)

    Giuffrida, Antonio; Romano, Matteo C.; Lozza, Giovanni

    2013-01-01

    Air-blown IGCC systems with hot fuel gas clean-up are investigated. In detail, the gas clean-up station consists of two reactors: in the first, the raw syngas exiting the gasifier and passed through high-temperature syngas coolers is desulfurized by means of a zinc oxide-based sorbent, whereas in the second the sulfided sorbent is duly regenerated. The hot fuel gas clean-up station releases H 2 S-free syngas, which is ready to fuel the combustion turbine after hot gas filtration, and a SO 2 -laden stream, which is successively treated in a wet scrubber. A thermodynamic analysis of two air-blown IGCC systems, the first with cold fuel gas clean-up and the second with hot fuel gas clean-up, both with a state-of-the-art combustion turbine as topping cycle, shows that it is possible to obtain a really attractive net efficiency (more than 51%) for the second system, with significant improvements in comparison with the first system. Nevertheless, higher efficiency is accomplished with a small reduction in the power output and no sensible efficiency improvements seem to be appreciated when the desulfurization temperature increases. Other IGCC systems, with an advanced 1500 °C-class combustion turbine as the result of technology improvements, are investigated as well, with efficiency as high as 53%. - Highlights: ► Hot fuel gas clean-up is a highly favorable technology for IGCC concepts. ► Significant IGCC efficiency improvements are possible with hot fuel gas clean-up. ► Size reductions of several IGCC components are possible. ► Higher desulfurization temperatures do not sensibly affect IGCC efficiency. ► IGCC efficiency as high as 53% is possible with a 1500°C-class combustion turbine

  10. High-level waste vitrification off-gas cleanup technology

    International Nuclear Information System (INIS)

    Hanson, M.S.

    1980-01-01

    This brief overview is intended to be a basis for discussion of needs and problems existing in the off-gas clean-up technology. A variety of types of waste form and processes are being developed in the United States and abroad. A description of many of the processes can be found in the Technical Alternative Documents (TAD). Concurrently, off-gas processing systems are being developed with most of the processes. An extensive review of methodology as well as decontamination factors can be found in the literature. Since it is generally agreed that the most advanced solidification process is vitrification, discussion here centers about the off-gas problems related to vitrification. With a number of waste soldification facilities around the world in operation, it can be shown that present technology can satisfy the present requirement for off-gas control. However, a number of areas within the technology base show potential for improvement. Fundamental as well as verification studies are needed to obtain the improvements

  11. Flue gas cleanup using the Moving-Bed Copper Oxide Process

    Energy Technology Data Exchange (ETDEWEB)

    Pennline, Henry W; Hoffman, James S

    2013-10-01

    The use of copper oxide on a support had been envisioned as a gas cleanup technique to remove sulfur dioxide (SO{sub 2}) and nitric oxides (NO{sub x}) from flue gas produced by the combustion of coal for electric power generation. In general, dry, regenerable flue gas cleanup techniques that use a sorbent can have various advantages, such as simultaneous removal of pollutants, production of a salable by-product, and low costs when compared to commercially available wet scrubbing technology. Due to the temperature of reaction, the placement of the process into an advanced power system could actually increase the thermal efficiency of the plant. The Moving-Bed Copper Oxide Process is capable of simultaneously removing sulfur oxides and nitric oxides within the reactor system. In this regenerable sorbent technique, the use of the copper oxide sorbent was originally in a fluidized bed, but the more recent effort developed the use of the sorbent in a moving-bed reactor design. A pilot facility or life-cycle test system was constructed so that an integrated testing of the sorbent over absorption/regeneration cycles could be conducted. A parametric study of the total process was then performed where all process steps, including absorption and regeneration, were continuously operated and experimentally evaluated. The parametric effects, including absorption temperature, sorbent and gas residence times, inlet SO{sub 2} and NO{sub x} concentration, and flyash loadings, on removal efficiencies and overall operational performance were determined. Although some of the research results have not been previously published because of previous collaborative restrictions, a summary of these past findings is presented in this communication. Additionally, the potential use of the process for criteria pollutant removal in oxy-firing of fossil fuel for carbon sequestration purposes is discussed.

  12. Potential for preparation of hot gas cleanup sorbents from spent hydroprocessing catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.; Biagini, M. [Canada Centre for Mineral and Energy Technology, Ottawa, ON (Canada). Energy Research Labs.

    1996-01-01

    Three spent-decoked hydroprocessing catalysts and two corresponding fresh catalysts were tested as hot gas clean-up sorbents and compared with the zinc ferrite using a simulated coal gasification gas mixture. The catalysts deposited only by coke exhibited relatively good cleaning efficiency. The catalyst deposited by coke and metals such as vanadium and nickel was less efficient. The useful life of the spent hydroprocessing catalysts may be extended if utilized as hot gas clean-up sorbents. 12 refs., 3 figs., 4 tabs.

  13. EBR-II Cover Gas Cleanup System upgrade process control system structure

    International Nuclear Information System (INIS)

    Carlson, R.B.; Staffon, J.D.

    1992-01-01

    The Experimental Breeder Reactor II (EBR-II) Cover Gas Cleanup System (CGCS) control system was upgraded in 1991 to improve control and provide a graphical operator interface. The upgrade consisted of a main control computer, a distributed control computer, a front end input/output computer, a main graphics interface terminal, and a remote graphics interface terminal. This paper briefly describes the Cover Gas Cleanup System and the overall control system; describes the main control computer hardware and system software features in more detail; and, then, describes the real-time control tasks, and how they interact with each other, and how they interact with the operator interface task

  14. EBR-II Cover Gas Cleanup System upgrade distributed control and front end computer systems

    International Nuclear Information System (INIS)

    Carlson, R.B.

    1992-01-01

    The Experimental Breeder Reactor II (EBR-II) Cover Gas Cleanup System (CGCS) control system was upgraded in 1991 to improve control and provide a graphical operator interface. The upgrade consisted of a main control computer, a distributed control computer, a front end input/output computer, a main graphics interface terminal, and a remote graphics interface terminal. This paper briefly describes the Cover Gas Cleanup System and the overall control system; gives reasons behind the computer system structure; and then gives a detailed description of the distributed control computer, the front end computer, and how these computers interact with the main control computer. The descriptions cover both hardware and software

  15. Legal aspects of the clean-up and reclamation of the manufactured gas plants

    Energy Technology Data Exchange (ETDEWEB)

    Joldzic, V. [Belgrade University, Belgrade (Yugoslavia). Inst. for Criminology and Sociological Research

    1995-12-31

    The laws associated with the cleanup of manufactured gas plants in Yugoslavia is described. These comprise the Environmental Protection Act; the Law about Space Planning and Organizing; Building Law; and Agricultural Land Use Law. Joint remedial action in the Danube Basin is discussed. 13 refs.

  16. Renewable Natural Gas Clean-up Challenges and Applications

    Science.gov (United States)

    2011-01-13

    produced from digesters ─ Animal manure (dairy cows, swine ) ─ Waste water treatment facilities > Methane from Landfills > RNG produced from...LNG) for vehicle fuel ─Ft. Lewis — Anaerobic digestion of waste water for production of hydrogen as a fuel cell vehicle fuel ─SCRA * – Landfill gas...BE CLEANED- UP AND PLACED IN THE NATURAL GAS PIPELINE SYSTEM 6 GTI RNG Project Examples >Example GTI Projects: ─Gills Onions— Anaerobic

  17. Hot Gas Cleanup Test Facility for gasification and pressurized combustion. Quarterly report, October--December 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-01

    The objective of this project is to evaluate hot gas particle control technologies using coal-derived gas streams. This will entail the design, construction, installation, and use of a flexible test facility which can operate under realistic gasification and combustion conditions. The major particulate control device issues to be addressed include the integration of the particulate control devices into coal utilization systems, on-line cleaning techniques, chemical and thermal degradation of components, fatigue or structural failures, blinding, collection efficiency as a function of particle size, and scale-up of particulate control systems to commercial size. The conceptual design of the facility was extended to include a within scope, phased expansion of the existing Hot Gas Cleanup Test Facility Cooperative Agreement to also address systems integration issues of hot particulate removal in advanced coal-based power generation systems. This expansion included the consideration of the following modules at the test facility in addition to the original Transport Reactor gas source and Hot Gas Cleanup Units: carbonizer/pressurized circulating fluidized bed gas source; hot gas cleanup units to mate to all gas streams; combustion gas turbine; and fuel cell and associated gas treatment. The major emphasis during this reporting period was continuing the detailed design of the facility and integrating the particulate control devices (PCDs) into structural and process designs. Substantial progress in underground construction activities was achieved during the quarter. Delivery and construction of coal handling and process structural steel began during the quarter. Delivery and construction of coal handling and process structural steel began during the quarter. MWK equipment at the grade level and the first tier are being set in the structure.

  18. Proceedings of the seventh annual gasification and gas stream cleanup systems contractors review meeting: Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Ghate, M.R.; Markel, K.E. Jr.; Jarr, L.A.; Bossart, S.J. (eds.)

    1987-08-01

    On June 16 through 19, 1987, METC sponsored the Seventh Annual Gasification and Gas Stream Cleanup Systems Contractors Review Meeting which was held at the Sheraton Lakeview Conference Center in Morgantown, West Virginia. The primary purpose of the meeting was threefold: to review the technical progress and current status of the gasification and gas stream cleanup projects sponsored by the Department of Energy; to foster technology exchange among participating researchers and other technical communities; to facilitate interactive dialogues which would identify research needs that would make coal-based gasification systems more attractive economically and environmentally. More than 310 representatives of Government, academia, industry, and foreign energy research organizations attended the 4-day meeting. Fifty-three papers and thirty poster dsplays were presented summarizing recent developments in the gasification and gas stream cleanup programs. Volume II covers papers presented at sessions 5 and 6 on system for the production of synthesis gas, and on system for the production of power. All papers have been processed for inclusion in the Energy Data Base.

  19. Proceedings of the seventh annual gasification and gas stream cleanup systems contractors review meeting: Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Ghate, M.R.; Markel, K.E. Jr.; Jarr, L.A.; Bossart, S.J. (eds.)

    1987-08-01

    On June 16 through 19, 1987, METC sponsored the Seventh Annual Gasification and Gas Stream Cleanup Systems Contractors Review Meeting which was held at the Sheraton Lakeview Conference Center in Morgantown, West Virginia. The primary purpose of the meeting was threefold: to review the technical progress and current status of the gasification and gas stream cleanup projects sponsored by the Department of Energy; to foster technology exchange among participating researchers and other technical communities; to facilitate interactive dialogues which would identify research needs that would make coal-based gasification systems more attractive economically and environmentally. More than 310 representatives of Government, academia, industry, and foreign energy research organizations attended the 4-day meeting. Fifty-three papers and thirty poster displays were presented summarizing recent developments in the gasification and gas stream cleanup programs. Volume I covers information presented at sessions 1 through 4 on systems for the production of Co-products and industrial fuel gas, environmental projects, and components and materials. Individual papers have been processed for the Energy Data Base.

  20. SOx-NOx-Rox Box{trademark} flue gas clean-up demonstration. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The SNRB{trademark} Flue Gas Cleanup Demonstration Project was cooperatively funded by the U.S. Department of Energy (DOE), the Ohio Coal Development Office (OCDO), B&W, the Electric Power Research Institute (EPRI), Ohio Edison, Norton Chemical Process Products Company and the 3M Company. The SNRB{trademark} technology evolved from the bench and laboratory pilot scale to be successfully demonstrated at the 5-MWe field scale. Development of the SNRB{trademark} process at B&W began with pilot testing of high-temperature dry sorbent injection for SO{sub 2} removal in the 1960`s. Integration of NO{sub x} reduction was evaluated in the 1970`s. Pilot work in the 1980`s focused on evaluation of various NO{sub x} reduction catalysts, SO{sub 2} sorbents and integration of the catalyst with the baghouse. This early development work led to the issuance of two US process patents to B&W - No. 4,309,386 and No. 4,793,981. An additional patent application for improvements to the process is pending. The OCDO was instrumental in working with B&W to develop the process to the point where a larger scale demonstration of the technology was feasible. This report represents the completion of Milestone M14 as specified in the Work Plan. B&W tested the SNRB{trademark} pollution control system at a 5-MWe demonstration facility at Ohio Edison`s R. E. Burger Plant located near Shadyside, Ohio. The design and operation were influenced by the results from laboratory pilot testing at B&W`s Alliance Research Center. The intent was to demonstrate the commercial feasibility of the SNRB{trademark} process. The SNRB{trademark} facility treated a 30,000 ACFM flue gas slipstream from Boiler No. 8. Operation of the facility began in May 1992 and was completed in May 1993.

  1. Production of activated char from Illinois coal for flue gas cleanup

    Science.gov (United States)

    Lizzio, A.A.; DeBarr, J.A.; Kruse, C.W.

    1997-01-01

    Activated chars were produced from Illinois coal and tested in several flue gas cleanup applications. High-activity chars that showed excellent potential for both SO2 and NOx removal were prepared from an Illinois No. 2 bituminous coal. The SO2 (120 ??C) and NOx (25 ??C) removal performance of one char compared favorably with that of a commercial activated carbon (Calgon Centaur). The NOx removal performance of the same char at 120 ??C exceeded that of the Centaur carbon by more than 1 order of magnitude. Novel char preparation methods were developed including oxidation/thermal desorption and hydrogen treatments, which increased and preserved, respectively, the active sites for SO2 and NOx adsorption. The results of combined SO2/NOx removal tests, however, suggest that SO2 and NOx compete for similar adsorption sites and SO2 seems to be more strongly adsorbed than NO. A low-activity, low-cost char was also developed for cleanup of incinerator flue gas. A three-step method involving coal preoxidation, pyrolysis, and CO2 activation was used to produce the char from Illinois coal. Five hundred pounds of the char was tested on a slipstream of flue gas from a commercial incinerator in Germany. The char was effective in removing >97% of the dioxins and furans present in the flue gas; mercury levels were below detectable limits.

  2. Hot gas cleanup test facility for gasification and pressurized combustion. Quarterly technical progress report, July 1--September 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    The objective of this project is to evaluate hot gas particle control technologies using coal-derived gas streams. This will entail the design, construction, installation, and use of a flexible test facility which can operate under realistic gasification and combustion conditions. The major particulate control device issues to be addressed include the integration of the particulate control devices into coal utilization systems, on-line cleaning techniques, chemical and thermal degradation of components, fatigue or structural failures, blinding, collection efficiency as a function of particle size, and scale-up of particulate control systems to commercial size. The conceptual design of the facility was extended to include a within scope, phased expansion of the existing Hot Gas Cleanup Test Facility Cooperative Agreement to also address systems integration issues of hot particulate removal in advanced coal-based power generation systems. This expansion included the consideration of the following modules at the test facility in addition to the existing Transport Reactor gas source and Hot Gas Cleanup Units: Carbonizer/Pressurized Circulating Fluidized Bed Gas Source; hot Gas Cleanup Units to mate to all gas streams; and Combustion Gas Turbine. Fuel Cell and associated gas treatment. This expansion to the Hot Gas Cleanup Test Facility is herein referred to as the Power Systems Development Facility (PSDF).

  3. A breakthrough in flue gas cleanup, CO2 mitigation and H2S removal

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Wolf; Wasas, James; Stenger, Raymond; Howell, Evan

    2010-09-15

    SWAPSOL Corp. is developing commercial processes around a newly discovered reaction that reduces H2S below detectable levels while reacting with CO2 to form water, sulfur and carsuls, a carbon-sulfur polymer. The Stenger-Wasas Process (SWAP) stands to simplify sulfur removal technology as it consumes CO2 in an exothermic reaction. The SWAP has applications in landfill, sour, flue and Claus tail gas cleanup and may replace Claus technology. Destruction of waste hydrocarbons provides a source of H2S. The primary reactions and variants have been independently verified and the chemical kinetics determined by a third party laboratory.

  4. A Numerical Study of Factors Affecting Fracture-Fluid Cleanup and Produced Gas/Water in Marcellus Shale: Part II

    Energy Technology Data Exchange (ETDEWEB)

    Seales, Maxian B.; Dilmore, Robert; Ertekin, Turgay; Wang, John Yilin

    2017-04-01

    Horizontal wells combined with successful multi-stage hydraulic fracture treatments are currently the most established method for effectively stimulating and enabling economic development of gas bearing organic-rich shale formations. Fracture cleanup in the Stimulated Reservoir Volume (SRV) is critical to stimulation effectiveness and long-term well performance. However, fluid cleanup is often hampered by formation damage, and post-fracture well performance frequently falls below expectations. A systematic study of the factors that hinder fracture fluid cleanup in shale formations can help optimize fracture treatments and better quantify long term volumes of produced water and gas. Fracture fluid cleanup is a complex process influenced by multi-phase flow through porous media (relative permeability hysteresis, capillary pressure etc.), reservoir rock and fluid properties, fracture fluid properties, proppant placement, fracture treatment parameters, and subsequent flowback and field operations. Changing SRV and fracture conductivity as production progresses further adds to the complexity of this problem. Numerical simulation is the best, and most practical approach to investigate such a complicated blend of mechanisms, parameters, their interactions, and subsequent impact on fracture fluid cleanup and well deliverability. In this paper, a 3-dimensional, 2-phase, dual-porosity model was used to investigate the impact of multiphase flow, proppant crushing, proppant diagenesis, shut-in time, reservoir rock compaction, gas slippage, and gas desorption on fracture fluid cleanup, and well performance in Marcellus shale. The research findings have shed light on the factors that substantially constrains efficient fracture fluid cleanup in gas shales, and provided guidelines for improved fracture treatment designs and water management.

  5. High Temperature Syngas Cleanup Technology Scale-up and Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, Ben [Research Triangle Inst. (RTI), Research Triangle Park, NC (United States); Turk, Brian [Research Triangle Inst. (RTI), Research Triangle Park, NC (United States); Denton, David [Research Triangle Inst. (RTI), Research Triangle Park, NC (United States); Gupta, Raghubir [Research Triangle Inst. (RTI), Research Triangle Park, NC (United States)

    2015-09-30

    Gasification is a technology for clean energy conversion of diverse feedstocks into a wide variety of useful products such as chemicals, fertilizers, fuels, electric power, and hydrogen. Existing technologies can be employed to clean the syngas from gasification processes to meet the demands of such applications, but they are expensive to build and operate and consume a significant fraction of overall parasitic energy requirements, thus lowering overall process efficiency. RTI International has developed a warm syngas desulfurization process (WDP) utilizing a transport-bed reactor design and a proprietary attrition-resistant, high-capacity solid sorbent with excellent performance replicated at lab, bench, and pilot scales. Results indicated that WDP technology can improve both efficiency and cost of gasification plants. The WDP technology achieved ~99.9% removal of total sulfur (as either H2S or COS) from coal-derived syngas at temperatures as high as 600°C and over a wide range of pressures (20-80 bar, pressure independent performance) and sulfur concentrations. Based on the success of these tests, RTI negotiated a cooperative agreement with the U.S. Department of Energy for precommercial testing of this technology at Tampa Electric Company’s Polk Power Station IGCC facility in Tampa, Florida. The project scope also included a sweet water-gas-shift process for hydrogen enrichment and an activated amine process for 90+% total carbon capture. Because the activated amine process provides some additional non-selective sulfur removal, the integration of these processes was expected to reduce overall sulfur in the syngas to sub-ppmv concentrations, suitable for most syngas applications. The overall objective of this project was to mitigate the technical risks associated with the scale up and integration of the WDP and carbon dioxide capture technologies, enabling subsequent commercial-scale demonstration. The warm syngas cleanup pre-commercial test unit

  6. EBR-II Cover Gas Cleanup System (CGCS) upgrade graphical interface design

    International Nuclear Information System (INIS)

    Staffon, J.D.; Peters, G.G.

    1992-01-01

    Technology advances in the past few years have prompted an effort at Argonne National Laboratory to replace existing equipment with high performance digital computers and color graphic displays. Improved operation of process systems can be achieved by utilizing state-of-the-art computer technology in the areas of process control and process monitoring. The Cover Gas Cleanup System (CGCS) at EBR-II is the first system to be upgraded with high performance digital equipment. The upgrade consisted of a main control computer, a distributed control computer, a front end input/output computer, a main graphics interface terminal, and a remote graphics interface terminal. This paper describes the main control computer and the operator interface control software

  7. Investigation of austenitic alloys for advanced heat recovery and hot-gas cleanup systems

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, R.W. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    Materials properties were collected for the design and construction of structural components for use in advanced heat recovery and hot gas cleanup systems. Alloys systems included 9Cr-1Mo-V steel, modified 316 stainless steel, modified type 310 stainless steel, modified 20Cr-25Ni-Nb stainless steel, and modified alloy 800. Experimental work was undertaken to expand the databases for potentially useful alloys. Types of testing included creep, stress-rupture, creep-crack growth, fatigue, and post-exposure short-time tensile tests. Because of the interest in relatively inexpensive alloys for service at 700 C and higher, research emphasis was placed on a modified type 310 stainless steel and a modified 20Cr-25Ni-Nb stainless steel. Both steels were found to have useful strength to 925 C with good weldability and ductility.

  8. Rapid and simple clean-up and derivatizaton procedure for the gas chromatographic determination of acidic drugs in plasma

    NARCIS (Netherlands)

    Roseboom, H.; Hulshoff, A.

    1979-01-01

    A rapid and simple clean-up and derivatization procedure that can be generally applied to the gas chromatographie (GC) determination of acidic drugs of various chemical and therapeutic classes is described. The drugs are extracted from acidified plasma with chloroform containing 5% of isopropanol,

  9. International Seminar on Gasification 2009 - Biomass Gasification, Gas Clean-up and Gas Treatment

    Energy Technology Data Exchange (ETDEWEB)

    2009-10-15

    During the seminar international and national experts gave presentations concerning Biomass gasification, Gas cleaning and gas treatment; and Strategy and policy issues. The presentations give an overview of the current status and what to be expected in terms of development, industrial interest and commercialization of different biomass gasification routes. The following PPT presentations are reproduced in the report: Black Liquor Gasification (Chemrec AB.); Gasification and Alternative Feedstocks for the Production of Synfuels and 2nd Generation Biofuels (Lurgi GmbH); Commercial Scale BtL Production on the Verge of Becoming Reality (Choren Industries GmbH.); Up-draft Biomass Gasification (Babcock and Wilcox Voelund A/S); Heterogeneous Biomass Residues and the Catalytic Synthesis of Alcohols (Enerkem); Status of the GoBiGas-project (Goeteborg Energi AB.); On-going Gasification Activities in Spain (University of Zaragoza,); Biomass Gasification Research in Italy (University of Perugia.); RDandD Needs and Recommendations for the Commercialization of High-efficient Bio-SNG (Energy Research Centre of the Netherlands.); Cleaning and Usage of Product Gas from Biomass Steam Gasification (Vienna University of Technology); Biomass Gasification and Catalytic Tar Cracking Process Development (Research Triangle Institute); Syngas Cleaning with Catalytic Tar Reforming (Franhofer UMSICHT); Biomass Gas Cleaning and Utilization - The Topsoee Perspective (Haldor Topsoee A/S); OLGA Tar Removal Technology (Dahlman); Bio-SNG - Strategy and Activities within E.ON (E.ON Ruhrgas AG); Strategy and Gasification Activities within Sweden (Swedish Energy Agency); 20 TWh/year Biomethane (Swedish Gas Association)

  10. Amine-based post-combustion CO2 capture in air-blown IGCC systems with cold and hot gas clean-up

    International Nuclear Information System (INIS)

    Giuffrida, A.; Bonalumi, D.; Lozza, G.

    2013-01-01

    Highlights: • Hot fuel gas clean-up is a very favorable technology for IGCC concepts. • IGCC net efficiency reduces to 41.5% when realizing post-combustion CO 2 capture. • Complex IGCC layouts are necessary if exhaust gas recirculation is realized. • IGCC performance does not significantly vary with exhaust gas recirculation. - Abstract: This paper focuses on the thermodynamic performance of air-blown IGCC systems with post-combustion CO 2 capture by chemical absorption. Two IGCC technologies are investigated in order to evaluate two different strategies of coal-derived gas clean-up. After outlining the layouts of two power plants, the first with conventional cold gas clean-up and the second with hot gas clean-up, attention is paid to the CO 2 capture station and to issues related to exhaust gas recirculation in combined cycles. The results highlight that significant improvements in IGCC performance are possible if hot coal-derived gas clean-up is realized before the syngas fuels the combustion turbine, so the energy cost of CO 2 removal in an amine-based post-combustion mode is less strong. In particular, IGCC net efficiency as high as 41.5% is calculated, showing an interesting potential if compared to the one of IGCC systems with pre-combustion CO 2 capture. Thermodynamic effects of exhaust gas recirculation are investigated as well, even though IGCC performance does not significantly vary against a more complicated plant layout

  11. SOx-NOx-Rox Box{trademark} flue gas clean-up demonstration. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    Babcock and Wilcox`s (B and W) SOx-NOx-Rox Box{trademark} process effectively removes SOx, NOx and particulate (Rox) from flue gas generated from coal-fired boilers in a single unit operation, a high temperature baghouse. The SNRB technology utilizes dry sorbent injection upstream of the baghouse for removal of SOx and ammonia injection upstream of a zeolitic selective catalytic reduction (SCR) catalyst incorporated in the baghouse to reduce NOx emissions. Because the SOx and NOx removal processes require operation at elevated gas temperatures (800--900 F) for high removal efficiency, high-temperature fabric filter bags are used in the baghouse. The SNRB technology evolved from the bench and laboratory pilot scale to be successfully demonstrated at the 5-MWe field scale. This report represents the completion of Milestone M14 as specified in the Work Plan. B and W tested the SNRB pollution control system at a 5-MWe demonstration facility at Ohio Edison`s R.E. Burger Plant located near Shadyside, Ohio. The design and operation were influenced by the results from laboratory pilot testing at B and W`s Alliance Research Center. The intent was to demonstrate the commercial feasibility of the SNRB process. The SNRB facility treated a 30,000 ACFM flue gas slipstream from Boiler No. 8. Operation of the facility began in May 1992 and was completed in May 1993. About 2,300 hours of high-temperature operation were achieved. The main emissions control performance goals of: greater than 70% SO{sub 2} removal using a calcium-based sorbent; greater than 90% NOx removal with minimal ammonia slip; and particulate emissions in compliance with the New Source Performance Standards (NSPS) of 0.03 lb/million Btu were exceeded simultaneously in the demonstration program when the facility was operated at optimal conditions. Testing also showed significant reductions in emissions of some hazardous air pollutants.

  12. Temperature and the Ideal Gas

    Science.gov (United States)

    Daisley, R. E.

    1973-01-01

    Presents some organized ideas in thermodynamics which are suitable for use with high school (GCE A level or ONC) students. Emphases are placed upon macroscopic observations and intimate connection of the modern definition of temperature with the concept of ideal gas. (CC)

  13. Development and reactivity tests of Ce-Zr-based Claus catalysts for coal gas cleanup

    Energy Technology Data Exchange (ETDEWEB)

    No-Kuk Park; Dong Cheul Han; Gi Bo Han; Si Ok Ryu; Tae Jin Lee; Ki Jun Yoon [Yeungnam University, Gyeongbuk (Republic of Korea). National Research Laboratory, School of Chemical Engineering and Technology

    2007-09-15

    Claus reaction (2H{sub 2}S + SO{sub 2} {leftrightarrow} 3/nS{sub n} + 2H{sub 2}O) was used to clean the gasified coal gas and the reactivity of several metal oxide-based catalysts on Claus reaction was investigated at various operating conditions. In order to convert H{sub 2}S contained in the gasified coal gas to elemental sulfur during Claus reaction, the catalysts having the high activity under the highly reducing condition with the moisture should be developed. CeO{sub 2}, ZrO{sub 2}, and Ce{sub 1-x}Zr{sub x}O{sub 2} catalysts were prepared for Claus reaction and their reactivity changes due to the existence of the reducing gases and H{sub 2}O in the fuel gas was investigated in this study. The Ce-based catalysts shows that their activity was deteriorated by the reduction of the catalyst due to the reducing gases at higher than 220{sup o}C. Meanwhile, the effect of the reducing gases on the catalytic activity was not considerable at low temperature. The activities of all three catalysts were degraded on the condition that the moisture existed in the test gas. Specifically, the Ce-based catalysts were remarkably deactivated by their sulfation. The Ce-Zr-based catalyst had a high catalytic activity when the reducing gases and the moisture co-existed in the simulated fuel gas. The deactivation of the Ce-Zr-based catalyst was not observed in this study. The lattice oxygen of the Ce-based catalyst was used for the oxidation of H{sub 2}S and the lattice oxygen vacancy on the catalyst was contributed to the reduction of SO{sub 2}. ZrO{sub 2} added to the Ce-Zr-based catalyst improved the redox properties of the catalyst in Claus reaction by increasing the mobility of the lattice oxygen of CeO{sub 2}. 21 refs., 14 figs.

  14. Low temperature wetting and cleanup of alkali metal-advanced electrical machine systems

    International Nuclear Information System (INIS)

    Gass, W.R.; Witkowski, R.E.; Burrow, G.C.

    1980-01-01

    Advanced homopolar electrical machines employing high electrical current density, liquid metal sliprings for current transfer utilize NaK/sub 78/ (78 w/o potassium, 22 w/o sodium) for the conducting fluid. Experiments have been performed to improve alkali metal/oxide clean-up procedures. Studies have also confirmed chemical and materials compatibility between barium doped NaK/sub 78/ and typical machine structural materials. 4 refs

  15. SUBTASK 3.12 – GASIFICATION, WARM-GAS CLEANUP, AND LIQUID FUELS PRODUCTION WITH ILLINOIS COAL

    Energy Technology Data Exchange (ETDEWEB)

    Stanislowski, Joshua; Curran, Tyler; Henderson, Ann

    2014-06-30

    The goal of this project was to evaluate the performance of Illinois No. 6 coal blended with biomass in a small-scale entrained-flow gasifier and demonstrate the production of liquid fuels under three scenarios. The first scenario used traditional techniques for cleaning the syngas prior to Fischer–Tropsch (FT) synthesis, including gas sweetening with a physical solvent. In the second scenario, the CO2 was not removed from the gas stream prior to FT synthesis. In the third scenario, only warm-gas cleanup techniques were used, such that the feed gas to the FT unit contained both moisture and CO2. The results of the testing showed that the liquid fuels production from the FT catalyst was significantly hindered by the presence of moisture and CO2 in the syngas. Further testing would be needed to determine if this thermally efficient process is feasible with other FT catalysts. This subtask was funded through the EERC–U.S. Department of Energy (DOE) Joint Program on Research and Development for Fossil Energy-Related Resources Cooperative Agreement No. DE-FC26-08NT43291. Nonfederal funding was provided by the Illinois Clean Coal Institute.

  16. Investigation and feasibility study of a former manufactured gas plant site in Tuttlingen (Germany), based on individually determined clean-up criteria

    Energy Technology Data Exchange (ETDEWEB)

    Heinecker, C.; Pickel, H.-J.; Duffek, J. [HPC Harress Pickel Consult GmbH, Fuldatal (Germany)

    1995-12-31

    At the request of the former plant operator, a manufactured gas plant site in Tuttlingen, Germany, was investigated from 1988 through 1992 for subsurface soil contamination resulting from former activities. In 1991, the contents of the former tar pits and parts of the adjacent soil contaminations were removed in the course of clean-up activities by means of excavation and disposed at a special waste site. Following an initial risk assessment, a remedial investigation was carried out in order to further delineate the contaminated areas as well as to create a reliable database for a feasibility study of remedial alternatives. The feasibility study followed applicable Baden-Wurttemberg state guidelines, including the following elements: Determination of the clean-up goals for soils; pre-selection of the clean-up procedure; cost estimate; cost-effectiveness study; Non-monetary evaluation; and total evaluation/clean-up proposal. The following general alternatives were available for the definition of clean-up goals: background values (`H-values`); general guidelines values (`SZ-values`); and clean-up goals based on contaminant fate and transport as well as site use (`SZA-values`).

  17. Evaluation of gasification and gas cleanup processes for use in molten carbonate fuel cell power plants. Final report. [Contains lists and evaluations of coal gasification and fuel gas desulfurization processes

    Energy Technology Data Exchange (ETDEWEB)

    Jablonski, G.; Hamm, J.R.; Alvin, M.A.; Wenglarz, R.A.; Patel, P.

    1982-01-01

    This report satisfies the requirements for DOE Contract AC21-81MC16220 to: List coal gasifiers and gas cleanup systems suitable for supplying fuel to molten carbonate fuel cells (MCFC) in industrial and utility power plants; extensively characterize those coal gas cleanup systems rejected by DOE's MCFC contractors for their power plant systems by virtue of the resources required for those systems to be commercially developed; develop an analytical model to predict MCFC tolerance for particulates on the anode (fuel gas) side of the MCFC; develop an analytical model to predict MCFC anode side tolerance for chemical species, including sulfides, halogens, and trace heavy metals; choose from the candidate gasifier/cleanup systems those most suitable for MCFC-based power plants; choose a reference wet cleanup system; provide parametric analyses of the coal gasifiers and gas cleanup systems when integrated into a power plant incorporating MCFC units with suitable gas expansion turbines, steam turbines, heat exchangers, and heat recovery steam generators, using the Westinghouse proprietary AHEAD computer model; provide efficiency, investment, cost of electricity, operability, and environmental effect rankings of the system; and provide a final report incorporating the results of all of the above tasks. Section 7 of this final report provides general conclusions.

  18. Integrated Warm Gas Multicontaminant Cleanup Technologies for Coal-Derived Syngas

    Energy Technology Data Exchange (ETDEWEB)

    Turk, Brian; Gupta, Raghubir; Sharma, Pradeepkumar; Albritton, Johnny; Jamal, Aqil

    2010-09-30

    One of the key obstacles for the introduction of commercial gasification technology for the production of power with Integrated Gasification Combined Cycle (IGCC) plants or the production of value added chemicals, transportation fuels, and hydrogen has been the cost of these systems. This situation is particularly challenging because the United States has ample coal resources available as raw materials and effective use of these raw materials could help us meet our energy and transportation fuel needs while significantly reducing our need to import oil. One component of the cost of these systems that faces strong challenges for continuous improvement is removing the undesirable components present in the syngas. The need to limit the increase in cost of electricity to < 35% for new coal-based power plants which include CO{sub 2} capture and sequestration addresses both the growing social concern for global climate change resulting from the emission of greenhouse gas and in particular CO{sub 2} and the need to control cost increases to power production necessary to meet this social objective. Similar improvements to technologies for trace contaminants are getting similar pressure to reduce environmental emissions and reduce production costs for the syngas to enable production of chemicals from coal that is cost competitive with oil and natural gas. RTI, with DOE/NETL support, has been developing sorbent technologies that enable capture of trace contaminants and CO{sub 2} at temperatures above 400 °F that achieve better capture performance, lower costs and higher thermal efficiency. This report describes the specific work of sorbent development for mercury (Hg), arsenic (As), selenium (Se), cadmium (Cd), and phosphorous (P) and CO{sub 2} removal. Because the typical concentrations of Hg, As, Se, Cd, and P are less than 10 ppmv, the focus has been on single-use sorbents with sufficient capacity to ensure replacement costs are cost effective. The research in this

  19. Carbon Formation and Metal Dusting in Hot-Gas Cleanup Systems of Coal Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Tortorelli, Peter F.; Judkins, Roddie R.; DeVan, Jackson H.; Wright, Ian G.

    1995-12-31

    There are several possible materials/systems degradation modes that result from gasification environments with appreciable carbon activities. These processes, which are not necessarily mutually exclusive, include carbon deposition, carburization, metal dusting, and CO disintegration of refractories. Carbon formation on solid surfaces occurs by deposition from gases in which the carbon activity (a sub C) exceeds unity. The presence of a carbon layer CO can directly affect gasifier performance by restricting gas flow, particularly in the hot gas filter, creating debris (that may be deposited elsewhere in the system or that may cause erosive damage of downstream components), and/or changing the catalytic activity of surfaces.

  20. Gas stream clean-up filter and method for forming same

    International Nuclear Information System (INIS)

    Mei, J.S.; DeVault, J.; Halow, J.S.

    1993-01-01

    A gas cleaning filter is formed in-situ within a vessel containing a fluidizable bed of granular material of a relatively large size fraction. A filter membrane provided by a porous metal or ceramic body or such a body supported a perforated screen on one side thereof is coated in-situ with a layer of the granular material from the fluidized bed by serially passing a bed-fluidizing gas stream through the bed of granular material and the membrane. The layer of granular material provides the filtering medium for the combined membrane-granular layer filter. The filter is not blinded by the granular material and provides for the removal of virtually all of the particulates from a process gas stream. The granular material can be at least partially provided by a material capable of chemically reacting with and removing sulfur compounds from the process gas stream. Low level radioactive waste containing organic material may be incinerated in a fluidized bed in communication with the described filter for removing particulates from the gaseous combustion products

  1. Sunlight Induced Rapid Oil Absorption and Passive Room-Temperature Release: An Effective Solution toward Heavy Oil Spill Cleanup

    KAUST Repository

    Wu, Mengchun

    2018-05-18

    Rapid cleanup and easy recovery of spilled heavy oils is always a great challenge due to their high viscosity (>103 mPa s). One of the efficient methods to absorb highly viscous oils is to reduce their viscosity by increasing their temperature. In this work, the authors integrate the sunlight‐induced light‐to‐heat conversion effect of polypyrrole (PPy) and thermoresponsive property of poly(N‐isopropylacrylamide) (PNIPAm) into the melamine sponge, which successfully delivers a fast heavy oil absorption under sunlight and passive oil release underwater at room temperature. Thanks to the rationally designed functionalities, the PNIPAm/PPy functionalized sponges possess oleophilicity and hydrophobicity under sunlight. Due to the photothermal effect of PPy, the sponges locally heat up contacting heavy oil under sunlight and reduce its viscosity to a point where the oil voluntarily flow into the pores of the sponge. The material in this work is able to rapidly absorb the heavy oil with room temperature viscosity as high as ≈1.60 × 105 mPa s. The absorbed oil can be passively forced out the sponge underwater at room temperature due to the hydrophilicity of PNIPAm. The sunlight responsive and multifunctional sponge represents a meaningful attempt in coming up with a sustainable solution toward heavy oil spill.

  2. Sunlight Induced Rapid Oil Absorption and Passive Room-Temperature Release: An Effective Solution toward Heavy Oil Spill Cleanup

    KAUST Repository

    Wu, Mengchun; Shi, Yusuf; Chang, Jian; Li, Renyuan; Ong, Chi Siang; Wang, Peng

    2018-01-01

    Rapid cleanup and easy recovery of spilled heavy oils is always a great challenge due to their high viscosity (>103 mPa s). One of the efficient methods to absorb highly viscous oils is to reduce their viscosity by increasing their temperature. In this work, the authors integrate the sunlight‐induced light‐to‐heat conversion effect of polypyrrole (PPy) and thermoresponsive property of poly(N‐isopropylacrylamide) (PNIPAm) into the melamine sponge, which successfully delivers a fast heavy oil absorption under sunlight and passive oil release underwater at room temperature. Thanks to the rationally designed functionalities, the PNIPAm/PPy functionalized sponges possess oleophilicity and hydrophobicity under sunlight. Due to the photothermal effect of PPy, the sponges locally heat up contacting heavy oil under sunlight and reduce its viscosity to a point where the oil voluntarily flow into the pores of the sponge. The material in this work is able to rapidly absorb the heavy oil with room temperature viscosity as high as ≈1.60 × 105 mPa s. The absorbed oil can be passively forced out the sponge underwater at room temperature due to the hydrophilicity of PNIPAm. The sunlight responsive and multifunctional sponge represents a meaningful attempt in coming up with a sustainable solution toward heavy oil spill.

  3. Advanced separation technology for flue gas cleanup. Final report, February 1998

    Energy Technology Data Exchange (ETDEWEB)

    Bhown, A.S.; Alvarado, D.; Pakala, N.; Tagg, T.; Riggs, T.; Ventura, S.; Sirkar, K.K.; Majumdar, S.; Bhaumick, D.

    1998-06-01

    The objective of this work by SRI International was to develop a novel system for regenerable SO{sub 2} and NO{sub x} scrubbing of flue gas that focuses on (1) a novel method for regenerating spent SO{sub 2} scrubbing liquor and (2) novel chemistry for reversible absorption of NO{sub x}. High efficiency, hollow fiber contactors (HFCs) were proposed as the devices for scrubbing the SO{sub 2} and NO{sub x} from the flue gas. The system would be designed to remove more than 95% of the SO{sub 2} and more than 75% of the NO{sub x} from flue gases typical of pulverized coal-fired power plants at a cost that is at least 20% less than combined wet limestone scrubbing of SO{sub x} and selective catalytic reduction of NO{sub x}. In addition, the process would generate only marketable by-products, if any (no waste streams are anticipated). The major cost item in existing technology is capital investment. Therefore, the approach was to reduce the capital cost by using high-efficiency, hollow fiber devices for absorbing and desorbing the SO{sub 2} and NO{sub x}. The authors also introduced new process chemistry to minimize traditionally well-known problems with SO{sub 2} and NO{sub x} absorption and desorption. The process and progress in its development are described.

  4. Carbon formation and metal dusting in hot-gas cleanup systems of coal gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Judkins, R.R.; Tortorelli, P.F.; Judkins, R.R.; DeVan, J.H.; Wright, I.G. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1995-11-01

    The product gas resulting from the partial oxidation of Carboniferous materials in a gasifier is typically characterized by high carbon and sulfur, but low oxygen, activities and, consequently, severe degradation of the structural and functional materials can occur. The objective of this task was to establish the potential risks of carbon deposition and metal dusting in advanced coal gasification processes by examining the current state of knowledge regarding these phenomena, making appropriate thermochemical calculations for representative coal gasifiers, and addressing possible mitigation methods. The paper discusses carbon activities, iron-based phase stabilities, steam injection, conditions that influence kinetics of carbon deposition, and influence of system operating parameters on carbon deposition and metal dusting.

  5. Advanced separation technology for flue gas cleanup. Quarterly technical report No. 11, October 1994--December 1994

    Energy Technology Data Exchange (ETDEWEB)

    Bhown, A.S.; Alvarado, D.; Pakala, N. [and others

    1994-12-01

    The objective of this work is to develop a novel system for regenerable SO{sub 2} and NO{sub x} scrubbing of flue gas that focuses on (a) a novel method for regeneration of spent SO{sub 2} scrubbing liquor and (b) novel chemistry for reversible absorption of NO{sub x}. In addition, high efficiency hollow fiber contactors (HFC) are proposed as the devices for scrubbing the SO{sub 2} and NO{sub x} from the flue gas. The system will be designed to remove more than 95% of the SO{sub x} and more than 75% of the NO{sub x} from flue gases typical of pulverized coal-fired power plants at a cost that is at least 20% less than combined wet limestone scrubbing of SO{sub x} and selective catalytic reduction of NO{sub x}. In addition, the process will make only marketable byproducts, if any (no waste streams). The major cost item in existing technology is capital investment. Therefore, our approach is to reduce the capital cost by using high efficiency hollow fiber devices for absorbing and desorbing the SO{sub 2} and NO{sub x}. We will also introduce new process chemistry to minimize traditionally well-known problems with SO{sub 2} and NO{sub x} absorption and desorption. For example, we will extract the SO{sub 2} from the aqueous scrubbing liquor into an oligomer of dimethylaniline to avoid the problem of organic liquid losses in the regeneration of the organic liquid.

  6. Microwave-assisted extraction through an aqueous medium and simultaneous cleanup by partition on hexane for determining pesticides in agricultural soils by gas chromatography: A critical study

    International Nuclear Information System (INIS)

    Fuentes, Edwar; Baez, Maria E.; Reyes, Dana

    2006-01-01

    A simple microwave-assisted extraction and partitioning method (MAEP) using water-acetonitrile and n-hexane for desorption and simultaneous partitioning, respectively, together with gas chromatography (GC) was studied to determine representative pesticides (trifluralin, metolachlor, chlorpyriphos and triadimefon) with a broad range of physico-chemical properties in agricultural soils. Three points were considered crucial in this study: instrumental and sample-associated factors affecting extraction of the target compounds were studied through experimental design; the spiking procedure at trace levels was carried out to reproduce the solute-soil sorption taking place in the environment as closely as possible; and results were analyzed taking into account the adsorption behaviour of the compounds on different kinds of soils. The complete analytical procedure proposed consisted of the MAEP of pesticides from 1.0 g of soil with 1 mL of 1:1 water/acetonitrile mixture, and 5 mL of hexane for trapping. The microwave heating program applied was 2 min at 250 W and 10 min at 900 W, and 130 deg. C maximum temperature. After extraction, the hexane layer was evaporated to dryness; the residue was re-dissolved and directly analyzed by gas chromatography electron capture detection (GC-ECD). Clean chromatograms were obtained without any additional cleanup step. Besides the four pesticides used to optimise MAEP, the method was applied to determine an additional group of pesticides (triallate, acetochlor, alachlor, endosulphan I and II, endrin, methoxychlor and tetradifon) in different soils. Most of the compounds studied were recovered in good yields with relative standard deviations (R.S.D.s) below 9% and detection limits ranged from 0.004 to 0.036 μg g -1 . The described method is efficient and fast to determine hydrophobic pesticides at ng g -1 level in soil with different clay-to-organic matter ratios

  7. Microwave-assisted extraction through an aqueous medium and simultaneous cleanup by partition on hexane for determining pesticides in agricultural soils by gas chromatography: A critical study

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes, Edwar [Departamento de Quimica Inorganica y Analitica, Facultad de Ciencias Quimicas y Farmaceuticas, Universidad de Chile, Santiago, Casilla 233 (Chile)]. E-mail: edfuentes@ciq.uchile.cl; Baez, Maria E. [Departamento de Quimica Inorganica y Analitica, Facultad de Ciencias Quimicas y Farmaceuticas, Universidad de Chile, Santiago, Casilla 233 (Chile); Reyes, Dana [Departamento de Quimica Inorganica y Analitica, Facultad de Ciencias Quimicas y Farmaceuticas, Universidad de Chile, Santiago, Casilla 233 (Chile)

    2006-09-25

    A simple microwave-assisted extraction and partitioning method (MAEP) using water-acetonitrile and n-hexane for desorption and simultaneous partitioning, respectively, together with gas chromatography (GC) was studied to determine representative pesticides (trifluralin, metolachlor, chlorpyriphos and triadimefon) with a broad range of physico-chemical properties in agricultural soils. Three points were considered crucial in this study: instrumental and sample-associated factors affecting extraction of the target compounds were studied through experimental design; the spiking procedure at trace levels was carried out to reproduce the solute-soil sorption taking place in the environment as closely as possible; and results were analyzed taking into account the adsorption behaviour of the compounds on different kinds of soils. The complete analytical procedure proposed consisted of the MAEP of pesticides from 1.0 g of soil with 1 mL of 1:1 water/acetonitrile mixture, and 5 mL of hexane for trapping. The microwave heating program applied was 2 min at 250 W and 10 min at 900 W, and 130 deg. C maximum temperature. After extraction, the hexane layer was evaporated to dryness; the residue was re-dissolved and directly analyzed by gas chromatography electron capture detection (GC-ECD). Clean chromatograms were obtained without any additional cleanup step. Besides the four pesticides used to optimise MAEP, the method was applied to determine an additional group of pesticides (triallate, acetochlor, alachlor, endosulphan I and II, endrin, methoxychlor and tetradifon) in different soils. Most of the compounds studied were recovered in good yields with relative standard deviations (R.S.D.s) below 9% and detection limits ranged from 0.004 to 0.036 {mu}g g{sup -1}. The described method is efficient and fast to determine hydrophobic pesticides at ng g{sup -1} level in soil with different clay-to-organic matter ratios.

  8. Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup, and Oxygen Separation Equipment; Task 9: Mixed Alcohols From Syngas -- State of Technology

    Energy Technology Data Exchange (ETDEWEB)

    Nexant Inc.

    2006-05-01

    This deliverable is for Task 9, Mixed Alcohols from Syngas: State of Technology, as part of National Renewable Energy Laboratory (NREL) Award ACO-5-44027, ''Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup and Oxygen Separation Equipment''. Task 9 supplements the work previously done by NREL in the mixed alcohols section of the 2003 technical report Preliminary Screening--Technical and Economic Assessment of Synthesis Gas to Fuels and Chemicals with Emphasis on the Potential for Biomass-Derived Syngas.

  9. A variable temperature cryostat that produces in situ clean-up germanium detector surfaces

    International Nuclear Information System (INIS)

    Pehl, R.H.; Madden, N.W.; Malone, D.F.; Cork, C.P.; Landis, D.A.; Xing, J.S.; Friesel, D.L.

    1988-11-01

    Variable temperature cryostats that can maintain germanium detectors at temperatures from 82 K to about 400 K while the thermal shield surrounding the detectors remains much colder when the detectors are warmed have been developed. Cryostats such as these offer the possibility of cryopumping material from the surface of detectors to the colder thermal shield. The diode characteristics of several detectors have shown very significant improvement following thermal cycles up to about 150 K in these cryostats. Important applications for cryostats having this attribute are many. 4 figs

  10. Numerical investigation on hydraulic fracture cleanup and its impact on the productivity of a gas well with a non-Newtonian fluid model

    Energy Technology Data Exchange (ETDEWEB)

    Friedel, T. [Schlumberger Data and Consulting Services, Sugar Land, TX (United States)

    2006-07-01

    There are many damage mechanisms associated with hydraulically fractured gas wells. These include hydraulic damage caused by invading fluids during the treatment and damage due to the stresses exerted on the fracture face. Damage to the proppant pack can also reduce conductivity and non-Darcy flow. However, these are not the only impacts of impaired productivity in tight-gas reservoirs, which do not respond to hydraulic fracturing as expected. Some sustain a flat production profile or show only a slow increase in production rate for several weeks or months. This is due to poor rock quality, strong stress dependency in permeability, hydraulic and mechanical damage. Another reason for the poor performance is related to the cleanup of the cross-linked fracturing fluid with its non-Newtonian characteristics. This paper presented an improved 3-phase cleanup model for the investigation of polymer gel cleanup. Yield stress was considered according to the Herschel-Bulkley rheology model. The viscosity model is based on the exact analytical solution, including the plug flow zone. According to data in the published literature, half of the gel phase can be recovered. The gel saturation gradually increases towards the fracture tips, thereby lowering the fracture conductivities. The residing gel damages the permeability and porosity of the proppant pack or causes damage to the fracture face, thereby reducing production potential. These results are in agreement with field observations where fracture half-lengths, conductivities and productivity are also lower than expected. Preliminary results suggest that capillary forces and load-water recovery have little influence on gel cleanup. 16 refs., 2 tabs., 17 figs.

  11. High temperature gas cleaning for pressurized gasification. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Alden, H.; Hagstroem, P.; Hallgren, A.; Waldheim, L. [TPS Termiska Processer AB, Nykoeping (Sweden)

    2000-04-01

    The purpose of the project was to build an apparatus to study pressurized, high temperature gas cleaning of raw gasification gas generated from biomass. A flexible and easy to operate pressurized apparatus was designed and installed for the investigations in high temperature gas cleaning by means of thermal, catalytic or chemical procedures. A semi continuos fuel feeding concept, at a maximum rate of 700 g/h, allowed a very constant formation of a gas product at 700 deg C. The gas product was subsequently introduced into a fixed bed secondary reactor where the actual gas cleanup or reformation was fulfilled. The installation work was divided into four work periods and apart from a few delays the work was carried out according to the time plan. During the first work period (January - June 1994) the technical design, drawings etc. of the reactor and additional parts were completed. All material for the construction was ordered and the installation work was started. The second work period (July - December 1994) was dedicated to the construction and the installation of the different components. Initial tests with the electrical heating elements, control system and gas supply were assigned to the third work period (January - June 1995). After the commissioning and the resulting modifications, initial pyrolysis and tar decomposition experiments were performed. During the fourth and final work period, (June - December 1995) encouraging results from first tests allowed the experimental part of the project work to commence, however in a slightly reduced program. The experimental part of the project work comparatively studied tar decomposition as a function of the process conditions as well as of the choice of catalyst. Two different catalysts, dolomite and a commercial Ni-based catalyst, were evaluated in the unit. Their tar cracking ability in the pressure interval 1 - 20 bar and at cracker bed temperatures between 800 - 900 deg C was compared. Long term tests to study

  12. Temperature of gas delivered from ventilators.

    Science.gov (United States)

    Chikata, Yusuke; Onodera, Mutsuo; Imanaka, Hideaki; Nishimura, Masaji

    2013-01-01

    Although heated humidifiers (HHs) are the most efficient humidifying device for mechanical ventilation, some HHs do not provide sufficient humidification when the inlet temperature to the water chamber is high. Because portable and home-care ventilators use turbines, blowers, pistons, or compressors to inhale in ambient air, they may have higher gas temperature than ventilators with piping systems. We carried out a bench study to investigate the temperature of gas delivered from portable and home-care ventilators, including the effects of distance from ventilator outlet, fraction of inspiratory oxygen (FIO2), and minute volume (MV). We evaluated five ventilators equipped with turbine, blower, piston, or compressor system. Ambient air temperature was adjusted to 24°C ± 0.5°C, and ventilation was set at FIO2 0.21, 0.6, and 1.0, at MV 5 and 10 L/min. We analyzed gas temperature at 0, 40, 80, and 120 cm from ventilator outlet and altered ventilator settings. While temperature varied according to ventilators, the outlet gas temperature of ventilators became stable after, at the most, 5 h. Gas temperature was 34.3°C ± 3.9°C at the ventilator outlet, 29.5°C ± 2.2°C after 40 cm, 25.4°C ± 1.2°C after 80 cm and 25.1°C ± 1.2°C after 120 cm (P < 0.01). FIO2 and MV did not affect gas temperature. Gas delivered from portable and home-care ventilator was not too hot to induce heated humidifier malfunctioning. Gas soon declined when passing through the limb.

  13. Medium temperature carbon dioxide gas turbine reactor

    International Nuclear Information System (INIS)

    Kato, Yasuyoshi; Nitawaki, Takeshi; Muto, Yasushi

    2004-01-01

    A carbon dioxide (CO 2 ) gas turbine reactor with a partial pre-cooling cycle attains comparable cycle efficiencies of 45.8% at medium temperature of 650 deg. C and pressure of 7 MPa with a typical helium (He) gas turbine reactor of GT-MHR (47.7%) at high temperature of 850 deg. C. This higher efficiency is ascribed to: reduced compression work around the critical point of CO 2 ; and consideration of variation in CO 2 specific heat at constant pressure, C p , with pressure and temperature into cycle configuration. Lowering temperature to 650 deg. C provides flexibility in choosing materials and eases maintenance through the lower diffusion leak rate of fission products from coated particle fuel by about two orders of magnitude. At medium temperature of 650 deg. C, less expensive corrosion resistant materials such as type 316 stainless steel are applicable and their performance in CO 2 have been proven during extensive operation in AGRs. In the previous study, the CO 2 cycle gas turbomachinery weight was estimated to be about one-fifth compared with He cycles. The proposed medium temperature CO 2 gas turbine reactor is expected to be an alternative solution to current high-temperature He gas turbine reactors

  14. Coolant cleanup system for a nuclear reactor

    International Nuclear Information System (INIS)

    Shiina, Atsushi; Usui, Naoshi; Yamamoto, Michiyoshi; Osumi, Katsumi.

    1983-01-01

    Purpose: To maintain the electric conductivity of reactor water lower and to minimize the heat loss in the cleanup system by providing a low temperature cleanup system and a high temperature cleanup system together. Constitution: A low temperature cleanup system using ion exchange resins as filter aids and a high temperature cleanup system using inorganic ion exchange materials as filter aids are provided in combination. A part of the reactor water in a reactor pressure vessel is passed through a conductivity meter, one portion of which flows into the high temperature cleanup system having no heat exchanger and filled with inorganic ion exchange materials by way of a first flow rate control valve and the other portion of which flows into the low temperature cleanup system having heat exchangers and filled with the ion exchange materials by way of a second control valve. The first control valve is adjusted so as to flow, for example, about more than 15% of the feedwater flow rate to the high temperature cleanup system and the second control valve is adjusted with its valve opening degree depending on the indication of the conductivity meter so as to flow about 2 - 7 % of the feedwater flow rate into the low temperature cleanup system, to thereby control the electric conductivity to between 0.055 - 0.3 μS/cm. (Moriyama, K.)

  15. Louisiana's statewide beach cleanup

    Science.gov (United States)

    Lindstedt, Dianne M.; Holmes, Joseph C.

    1989-01-01

    Litter along Lousiana's beaches has become a well-recognized problem. In September 1987, Louisiana's first statewide beach cleanup attracted about 3300 volunteers who filled 16,000 bags with trash collected along 15 beaches. An estimated 800,173 items were gathered. Forty percent of the items were made of plastic and 11% were of polystyrene. Of all the litter collected, 37% was beverage-related. Litter from the oil and gas, commercial fishing, and maritime shipping industries was found, as well as that left by recreational users. Although beach cleanups temporarily rid Louisiana beaches of litter, the real value of the effort is in public participation and education. Civic groups, school children, and individuals have benefited by increasing their awareness of the problems of trash disposal.

  16. Mold: Cleanup and Remediation

    Science.gov (United States)

    ... National Center for Environmental Health (NCEH) Cleanup and Remediation Recommend on Facebook Tweet Share Compartir On This ... CDC and EPA on mold cleanup, removal and remediation. Cleanup information for you and your family Homeowner’s ...

  17. Reactor water clean-up device

    International Nuclear Information System (INIS)

    Tanaka, Koji; Egashira, Yasuo; Shimada, Fumie; Igarashi, Noboru.

    1983-01-01

    Purpose: To save a low temperature reactor water clean-up system indispensable so far and significantly simplify the system by carrying out the reactor water clean-up solely in a high temperature reactor water clean-up system. Constitution: The reactor water clean-up device comprises a high temperature clean-up pump and a high temperature adsorption device for inorganic adsorbents. The high temperature adsorption device is filled with amphoteric ion adsorbing inorganic adsorbents, or amphoteric ion adsorbing inorganic adsorbents and anionic adsorbing inorganic adsorbents. The reactor water clean-up device introduces reactor water by the high temperature clean-up pump through a recycling system to the high temperature adsorption device for inorganic adsorbents. Since cations such as cobalt ions and anions such as chlorine ions in the reactor water are simultaneously removed in the device, a low temperature reactor water clean-up system which has been indispensable so far can be saved to realize the significant simplification for the entire system. (Seki, T.)

  18. Adsorption purification of helium coolant of high-temperature gas-cooled reactors of carbon dioxide

    International Nuclear Information System (INIS)

    Varezhkin, A.V.; Zel'venskij, Ya.D.; Metlik, I.V.; Khrulev, A.A.; Fedoseenkin, A.N.

    1986-01-01

    A series experiments on adsorption purification of helium of CO 2 using national adsorbent under the conditions characteristic of HTGR type reactors cleanup system is performed. The experimnts have been conducted under the dynamic mode with immobile adsorbent layer (CaA zeolite) at gas flow rates from 0,02 to 0,055 m/s in the pressure range from 0,8 to 5 MPa at the temperature of 273 and 293 K. It is shown that the adsorption grows with the decrease of gas rate, i.e. with increase of contact time with adsorbent. The helium pressure, growth noticeably whereas the temperature decrease from 293 to 273 K results in adsorption 2,6 times increase. The conclusion is drawn that it is advisable drying and purification of helium of CO 2 to perform separately using different zeolites: NaA - for water. CaA - for CO 2 . Estimations of purification unit parameters are realized

  19. Optimized cleanup method for the determination of short chain polychlorinated n-alkanes in sediments by high resolution gas chromatography/electron capture negative ion-low resolution mass spectrometry

    International Nuclear Information System (INIS)

    Gao Yuan; Zhang Haijun; Chen Jiping; Zhang Qing; Tian Yuzeng; Qi Peipei; Yu Zhengkun

    2011-01-01

    Graphical abstract: The sediment sample could be purified by the optimized cleanup method, and satisfying cleanup efficiency was obtained. Highlights: → The elution characters of sPCAs and interfering substances were evaluated on three adsorbents. → An optimized cleanup method was developed for sPCAs with satisfying cleanup efficiency. → The cleanup method combined with HRGC/ECNI-LRMS was applied for sPCAs analysis. → The sPCAs levels range from 53.6 ng g -1 to 289.3 ng g -1 in tested sediment samples. - Abstract: The performances of three adsorbents, i.e. silica gel, neutral and basic alumina, in the separation of short chain polychlorinated n-alkanes (sPCAs) from potential interfering substances such as polychlorinated biphenyls (PCBs) and organochlorine pesticides were evaluated. To increase the cleanup efficiency, a two-step cleanup method using silica gel column and subsequent basic alumina column was developed. All the PCB and organochlorine pesticides could be removed by this cleanup method. The very satisfying cleanup efficiency of sPCAs has been achieved and the recovery in the cleanup method reached 92.7%. The method detection limit (MDL) for sPCAs in sediments was determined to be 14 ng g -1 . Relative standard deviation (R.S.D.) of 5.3% was obtained for the mass fraction of sPCAs by analyzing four replicates of a spiked sediment sample. High resolution gas chromatography/electron capture negative ion-low resolution mass spectrometry (HRGC/ECNI-LRMS) was used for sPCAs quantification by monitoring [M-HCl]· - ions. When applied to the sediment samples from the mouth of the Daliao River, the optimized cleanup method in conjunction with HRGC/ECNI-LRMS allowed for highly selective identifications for sPCAs. The sPCAs levels in sediment samples are reported to range from 53.6 ng g -1 to 289.3 ng g -1 . C 10 - and C 11 -PCAs are the dominant residue in most of investigated sediment samples.

  20. Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup, and Oxygen Separation Equipment; Task 1: Cost Estimates of Small Modular Systems

    Energy Technology Data Exchange (ETDEWEB)

    Nexant Inc.

    2006-05-01

    This deliverable is the Final Report for Task 1, Cost Estimates of Small Modular Systems, as part of NREL Award ACO-5-44027, ''Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup and Oxygen Separation Equipment''. Subtask 1.1 looked into processes and technologies that have been commercially built at both large and small scales, with three technologies, Fluidized Catalytic Cracking (FCC) of refinery gas oil, Steam Methane Reforming (SMR) of Natural Gas, and Natural Gas Liquids (NGL) Expanders, chosen for further investigation. These technologies were chosen due to their applicability relative to other technologies being considered by NREL for future commercial applications, such as indirect gasification and fluidized bed tar cracking. Research in this subject is driven by an interest in the impact that scaling has on the cost and major process unit designs for commercial technologies. Conclusions from the evaluations performed could be applied to other technologies being considered for modular or skid-mounted applications.

  1. Automated mini-column solid-phase extraction cleanup for high-throughput analysis of chemical contaminants in foods by low-pressure gas chromatography – tandem mass spectrometry

    Science.gov (United States)

    This study demonstrated the application of an automated high-throughput mini-cartridge solid-phase extraction (mini-SPE) cleanup for the rapid low-pressure gas chromatography – tandem mass spectrometry (LPGC-MS/MS) analysis of pesticides and environmental contaminants in QuEChERS extracts of foods. ...

  2. IAEA high temperature gas cooled reactor activities

    International Nuclear Information System (INIS)

    Kendall, J.M.

    2001-01-01

    IAEA activities on high temperature gas cooled reactors are conducted with the review and support of Member States, primarily through the International Working Group on Gas Cooled Reactors (IWGGCR). This paper summarises the results of the IAEA gas cooled reactor project activities in recent years along with ongoing current activities through a review of Co-ordinated Research Projects (CRPs), meetings and other international efforts. A series of three recently completed CRPs have addressed the key areas of reactor physics for LEU fuel, retention of fission products, and removal of post shutdown decay heat through passive heat transport mechanisms. These activities along with other completed and ongoing supporting CRPs and meetings are summarised with reference to detailed documentation of the results. (author)

  3. High temperature gas cooled nuclear reactor

    International Nuclear Information System (INIS)

    Hosegood, S.B.; Lockett, G.E.

    1975-01-01

    For high-temperature gas cooled reactors it is considered advantageous to design the core so that the moderator blocks can be removed and replaced by some means of standpipes normally situated in the top of the reactor vessel. An arrangement is here described to facilitate these operations. The blocks have end faces shaped as irregular hexagons with three long sides of equal length and three short sides also of equal length, one short side being located between each pair of adjacent long sides, and the long sides being inclined towards one another at 60 0 . The block defines a number of coolant channels located parallel to its sides. Application of the arrangement to a high temperature gas-cooled reactor with refuelling standpipes is described. The standpipes are located in the top of the reactor vessel above the tops of the columns and are disposed coaxially above the hexagonal channels, with diameters that allow the passage of the blocks. (U.K.)

  4. The modular high temperature gas cooled reactor

    International Nuclear Information System (INIS)

    Lutz, D.E.; Lipps, A.J.

    1984-01-01

    Due to relatively high operating temperatures, the gas-cooled reactor has the potential to serve a wide variety of energy applications. This paper discusses the energy applications which can be served by the modular HTGR, the magnitude of the potential markets, and the HTGR product cost incentives relative to fossil fuel competition. Advantages of the HTGR modular systems are presented along with a description of the design features and performance characteristics of the current reference HTGR modular systems

  5. Rotational temperature determinations in molecular gas lasers

    International Nuclear Information System (INIS)

    Weaver, L.A.; Taylor, L.H.; Denes, L.J.

    1975-01-01

    The small-signal gain expressions for vibrational-rotational transitions are examined in detail to determine possible methods of extracting the rotational temperature from experimental gain measurements in molecular gas lasers. Approximate values of T/subr/ can be deduced from the rotational quantum numbers for which the P- and R-branch gains are maximum. Quite accurate values of T/subr/ and the population inversion density (n/subv//sub prime/-n/subv//sub double-prime/) can be determined by fitting data to suitably linearized gain relationships, or by performing least-squares fits of the P- and R-branch experimental data to the full gain expressions. Experimental gain measurements for 15 P-branch and 12 R-branch transitions in the 10.4-μm CO 2 band have been performed for pulsed uv-preionized laser discharges in CO 2 : N 2 : He=1 : 2 : 3 mixtures at 600 Torr. These data are subjected to the several gain analyses described herein, yielding a rotational temperature of 401plus-or-minus10 degreeK and an inversion density of (3.77plus-or-minus0.07) times10 17 cm -3 for conditions of maximum gain. These techniques provide accurate values of the gas temperature in molecular gas lasers with excellent temporal and spatial resolution, and should be useful in extending the conversion efficiency and arcing limits of high-energy electrically exc []ted lasers

  6. High temperature gas-cooled reactor: gas turbine application study

    International Nuclear Information System (INIS)

    1980-12-01

    The high-temperature capability of the High-Temperature Gas-Cooled Reactor (HTGR) is a distinguishing characteristic which has long been recognized as significant both within the US and within foreign nuclear energy programs. This high-temperature capability of the HTGR concept leads to increased efficiency in conventional applications and, in addition, makes possible a number of unique applications in both electrical generation and industrial process heat. In particular, coupling the HTGR nuclear heat source to the Brayton (gas turbine) Cycle offers significant potential benefits to operating utilities. This HTGR-GT Application Study documents the effort to evaluate the appropriateness of the HTGR-GT as an HTGR Lead Project. The scope of this effort included evaluation of the HTGR-GT technology, evaluation of potential HTGR-GT markets, assessment of the economics of commercial HTGR-GT plants, and evaluation of the program and expenditures necessary to establish HTGR-GT technology through the completion of the Lead Project

  7. High temperature gas-cooled reactor: gas turbine application study

    Energy Technology Data Exchange (ETDEWEB)

    1980-12-01

    The high-temperature capability of the High-Temperature Gas-Cooled Reactor (HTGR) is a distinguishing characteristic which has long been recognized as significant both within the US and within foreign nuclear energy programs. This high-temperature capability of the HTGR concept leads to increased efficiency in conventional applications and, in addition, makes possible a number of unique applications in both electrical generation and industrial process heat. In particular, coupling the HTGR nuclear heat source to the Brayton (gas turbine) Cycle offers significant potential benefits to operating utilities. This HTGR-GT Application Study documents the effort to evaluate the appropriateness of the HTGR-GT as an HTGR Lead Project. The scope of this effort included evaluation of the HTGR-GT technology, evaluation of potential HTGR-GT markets, assessment of the economics of commercial HTGR-GT plants, and evaluation of the program and expenditures necessary to establish HTGR-GT technology through the completion of the Lead Project.

  8. Reliability of reactor plant water cleanup pumps

    International Nuclear Information System (INIS)

    Pearson, J.L.

    1979-01-01

    Carolina Power and Light Company's Brunswick 2 nuclear plant experienced a high reactor water cleanup pump-failure rate until inlet temperature and flow were reduced and mechanical modifications were implemented. Failures have been zero for about one year, and water cleanup efficiency has increased

  9. Two methods to measure granular gas temperature

    Science.gov (United States)

    Chastaing, J.-Y.; Géminard, J.-C.; Naert, A.

    2017-07-01

    Grains are vibrated so as to achieve a granular gas, here regarded as an archetype of a dissipative non equilibrium steady state (NESS). We report on two distinct and concordant experimental measures of the system effective temperature. To do so, a blade fastened to the shaft of a small DC-motor, immersed in the grains, behaves as a driven 1D Brownian rotator, which is used as both actuator and sensor simultaneously. On the one hand, the Gallavotti-Cohen fluctuation theorem, which involves a measure of the asymmetry of the energy exchanges between the rotator and the NESS reservoir, provides a first effective temperature. On the other hand, the fluctuation-dissipation theorem, which involves the relation between the spontaneous fluctuations and the response to a weak perturbation, defines a second, independent, effective temperature. Both methods, even though they are based on drastically different ideas, give nicely concordant results.

  10. Bimodular high temperature planar oxygen gas sensor

    Directory of Open Access Journals (Sweden)

    Xiangcheng eSun

    2014-08-01

    Full Text Available A bimodular planar O2 sensor was fabricated using NiO nanoparticles (NPs thin film coated yttria-stabilized zirconia (YSZ substrate. The thin film was prepared by radio frequency (r.f. magnetron sputtering of NiO on YSZ substrate, followed by high temperature sintering. The surface morphology of NiO nanoparticles film was characterized by atomic force microscopy (AFM and scanning electron microscopy (SEM. X-ray diffraction (XRD patterns of NiO NPs thin film before and after high temperature O2 sensing demonstrated that the sensing material possesses a good chemical and structure stability. The oxygen detection experiments were performed at 500 °C, 600 °C and 800 °C using the as-prepared bimodular O2 sensor under both potentiometric and resistance modules. For the potentiometric module, a linear relationship between electromotive force (EMF output of the sensor and the logarithm of O2 concentration was observed at each operating temperature, following the Nernst law. For the resistance module, the logarithm of electrical conductivity was proportional to the logarithm of oxygen concentration at each operating temperature, in good agreement with literature report. In addition, this bimodular sensor shows sensitive, reproducible and reversible response to oxygen under both sensing modules. Integration of two sensing modules into one sensor could greatly enrich the information output and would open a new venue in the development of high temperature gas sensors.

  11. Fluidized-bed calcination of LWR fuel-reprocessing HLLW: requirements and potential for off-gas cleanup

    International Nuclear Information System (INIS)

    Schindler, R.E.

    1979-01-01

    Fluidized-bed solidification (calcination) was developed on a pilot scale for a variety of simulated LWR high-level liquid-waste (HLLW) and blended high-level and intermediate-level liquid-waste (ILLW) compositions. It has also been demonstrated with ICPP fuel-reprocessing waste since 1963 in the Waste Calcining Facility (WCF) at gross feed rates of 5 to 12 m 3 /day. A fluidized-bed calciner produces a relatively large volume of off-gas. A calciner solidifying 6 m 3 /day of liquid waste would generate about 13 standard m 3 /min of off-gas containing 10 to 20 g of entrained solids per standard m 3 of off-gas. Use of an off-gas system similar to that of the WCF could provide an overall process decontamination factor for particulates of about 2 x 10 10 . A potential advantage of fluidized-bed calcination over other solidification methods is the ability to control ruthenium volatilization from the calciner at less than 0.01% by calcining at 500 0 C or above. Use of an off-gas system similar to that of the WCF would provide an overall process decontamination factor for volatile ruthenium of greater than 1.6 x 10 7

  12. Reactor coolant cleanup device

    International Nuclear Information System (INIS)

    Igarashi, Noboru.

    1986-01-01

    Purpose: To enable to introduce reactor water at high temperature and high pressure as it is, as well as effectively adsorb to eliminate cobalt in reactor water. Constitution: The coolant cleanup device comprises a vessel main body inserted to coolant pipeway circuits in a water cooled reactor power plant and filters contained within the vessel main body. The filters are prepared by coating and baking powder of metal oxides such as manganese ferrite having a function capable of adsorbing cobalt in the coolants onto the surface of supports made of metals or ceramics resistant to strong acids and alkalies in the form of three-dimensional network structure, for example, zircaloy-2, SUS 303 and the zirconia (baking) to form a basic filter elements. The basic filter elements are charged in plurality to the vessel main body. (Kawaiami, Y.)

  13. Removal of dust from flue gas at elevated temperatures and pressures. Roeggasrensning for stoev ved hoej temperatur og hoejt tryk

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, D. V.; Rasmussen, J.

    1989-06-15

    Several new coal-based power generation systems are now ready for commercial application. Especially Integrated coal Gasification with combined Cycle (IGCC) and pressurized Fluidized Bed Combustion possess the potential for reducing emissions of SOx, NOx and particulates compared to conventional technology. In addition to this a decrease in heat-rate is possible. However, the decrease in heat-rate is dependant on the temperature of which the removal of particulated and gaseous pollutants takes place. Using state-of-the-art technology this temperature is 25-40 deg. C, but the efficiency improvement will only be substantial if the temperature can be raised to 400-500 deg. C or more. The coal gasification, which is the heart of an IGCC-system, can be caried out in a number of ways. Since the hot gas clean-up equipment (HGCU) to some extent is dependant on the gasification technology used, a description of the leading coal gasification systems is given. It is concluded that special interest should be given to gasifiers of the entrained flow type. The aim is to develope a HGCU-system for the removal of gaseous pollutants as well as particulate matter. The operating principles and stage of development of the competing technologies for dust removal at high temperature and pressure are described. Special attention is paid to the electrostatic precipitator, and possible solutions to problems related ot this technology are given. (AB) 165 refs.

  14. Gas Temperature Measurement in a Glow Discharge Plasma

    Science.gov (United States)

    Sloneker, Kenneth; Podder, Nirmol; McCurdy, William E.; Shi, Shi

    2009-10-01

    In this study a relatively inexpensive quartz protected thermocouple is used to measure the gas temperature in the positive column of a glow discharge plasma. For simplicity a K-type thermocouple is used to interpret the gas temperature from the sensor voltage at pressures from 0.5 Torr to 15 Torr and discharge currents from 5 mA to 120 mA. Gas temperature is investigated as a function of the gas pressure at fixed discharge currents and as a function of discharge current at fixed gas pressures in three different gas species (Ar, N2, and He). An infinite cylinder model is used to compute the average gas temperature of the discharge from joule heating and gas thermal conductivity. The model and measurement data agree within 1% to 10% depending on plasma parameters. Data for all three gases have a similar quasi-linear increasing error as compared to the model.

  15. Application of boreal forest toxicity data in the decision-making process for contaminated soil clean-up remediation at oil and gas fields in Western Canada

    International Nuclear Information System (INIS)

    Scroggins, R.; Princz, J.; Moody, M.; Olsgard-Dumanski, M.; Haderlein, L.; Moore, B.

    2010-01-01

    This presentation reported on a multi-year research project in which a broad range of boreal forest test methods for assessing petroleum hydrocarbon (PHC) toxicity in contaminated soil were used to show that clean-up decisions can be made on a field-wide basis through focused biological testing of typical drill sump and flare pit locations within an oil and gas field. Remediation at most sites will likely be limited to the Alberta soil eco-contact guidelines for PHC F2 and F3 fractions. Since Tier 1 eco-contact guidelines are derived using toxicity data from fresh crude and using agricultural plant species, it was more logical to follow a Tier 2 eco-contact pathway approach because most contamination was related to drilling sumps and flare pits containing highly weathered PHCs and species native to the boreal eco-zone of Canada. The site-specific remedial objective (SSRO) option within the Tier 2 guideline was used because of the large number of sites requiring remediation, and the similarity of sites within pre-determined Risk Assessment Zones. For representative contaminated soils, a SSRO was derived from the twenty-fifth percentile of the estimated species sensitivity distribution of all acceptable boreal plant, earthworm, springtail and mite test endpoints. The purpose of the project was to reduce soil volumes sent to landfill during site remediation by showing that residual impacts from weathered PHC in soil do not have damaging effects on boreal forest receptors following remediation. Data was included to show the value of this approach and the variability between sites and their effect on regionalizing a Tier 2 eco-contact guideline.

  16. Application of boreal forest toxicity data in the decision-making process for contaminated soil clean-up remediation at oil and gas fields in Western Canada

    Energy Technology Data Exchange (ETDEWEB)

    Scroggins, R.; Princz, J. [Environment Canada, Ottawa, ON (Canada); Moody, M. [Saskatchewan Research Council, Regina, SK (Canada); Olsgard-Dumanski, M.; Haderlein, L. [WorleyParsons Canada, Calgary, AB (Canada); Moore, B. [Devon Canada Corp., Calgary, AB (Canada)

    2010-07-01

    This presentation reported on a multi-year research project in which a broad range of boreal forest test methods for assessing petroleum hydrocarbon (PHC) toxicity in contaminated soil were used to show that clean-up decisions can be made on a field-wide basis through focused biological testing of typical drill sump and flare pit locations within an oil and gas field. Remediation at most sites will likely be limited to the Alberta soil eco-contact guidelines for PHC F2 and F3 fractions. Since Tier 1 eco-contact guidelines are derived using toxicity data from fresh crude and using agricultural plant species, it was more logical to follow a Tier 2 eco-contact pathway approach because most contamination was related to drilling sumps and flare pits containing highly weathered PHCs and species native to the boreal eco-zone of Canada. The site-specific remedial objective (SSRO) option within the Tier 2 guideline was used because of the large number of sites requiring remediation, and the similarity of sites within pre-determined Risk Assessment Zones. For representative contaminated soils, a SSRO was derived from the twenty-fifth percentile of the estimated species sensitivity distribution of all acceptable boreal plant, earthworm, springtail and mite test endpoints. The purpose of the project was to reduce soil volumes sent to landfill during site remediation by showing that residual impacts from weathered PHC in soil do not have damaging effects on boreal forest receptors following remediation. Data was included to show the value of this approach and the variability between sites and their effect on regionalizing a Tier 2 eco-contact guideline.

  17. Coolant clean-up and recycle systems

    International Nuclear Information System (INIS)

    Ito, Takao.

    1979-01-01

    Purpose: To increase the service life of mechanical seals in a shaft sealing device, eliminate leakages and improve the safety by providing a recycle pump for feeding coolants to a coolant clean-up device upon reactor shut-down and adapting the pump treat only low temperature and low pressure coolants. Constitution: The system is adapted to partially take out coolants from the pipeways of a recycling pump upon normal operation and feed them to a clean-up device. Upon reactor shut-down, the recycle pump is stopped and coolants are extracted by the recycle pump for shut-down into the clean-up device. Since the coolants are not fed to the clean-up device by the recycle pump during normal operation as conducted so far, high temperature and high pressure coolants are not directly fed to the recycle pump, thereby enabling to avoid mechanical problems in the pump. (Kamimura, M.)

  18. Effect of temperature on crack initiation in gas formed structures

    Energy Technology Data Exchange (ETDEWEB)

    Gohari, S.; Vrcelj, Z.; Sharifi, S.; Sharifishourabi, G.; Abadi, R. [Universiti Teknlogi Malaysia, Skudai (Malaysia)

    2013-12-15

    In the gas forming process, the work piece is formed by applying gas pressure. However, the gas pressure and the accompanying gas temperature can result in crack initiation and unstable crack growth. Thus, it is vital to determine the critical values of applied gas pressure and temperature to avoid crack and fracture failure. We studied the mechanism of fracture using an experimental approach and finite element simulations of a perfect aluminum sheet containing no inclusions and voids. The definition of crack was based on ductile damage mechanics. For inspection of initiation of crack and rupture in gas-metal forming, the ABAQUS/EXPLICIT simulation was used. In gas forming, the applied load is the pressure applied rather than the punching force. The results obtained from both the experimental approach and finite element simulations were compared. The effects of various parameters, such as temperature and gas pressure value on crack initiation, were taken into account.

  19. High-temperature Gas Reactor (HTGR)

    Science.gov (United States)

    Abedi, Sajad

    2011-05-01

    General Atomics (GA) has over 35 years experience in prismatic block High-temperature Gas Reactor (HTGR) technology design. During this period, the design has recently involved into a modular have been performed to demonstrate its versatility. This versatility is directly related to refractory TRISO coated - particle fuel that can contain any type of fuel. This paper summarized GA's fuel cycle studies individually and compares each based upon its cycle sustainability, proliferation-resistance capabilities, and other performance data against pressurized water reactor (PWR) fuel cycle data. Fuel cycle studies LEU-NV;commercial HEU-Th;commercial LEU-Th;weapons-grade plutonium consumption; and burning of LWR waste including plutonium and minor actinides in the MHR. results show that all commercial MHR options, with the exception of HEU-TH, are more sustainable than a PWR fuel cycle. With LEU-NV being the most sustainable commercial options. In addition, all commercial MHR options out perform the PWR with regards to its proliferation-resistance, with thorium fuel cycle having the best proliferation-resistance characteristics.

  20. Thermodynamics of a classical ideal gas at arbitrary temperatures

    OpenAIRE

    Pal, Palash B.

    2002-01-01

    We propose a fundamental relation for a classical ideal gas that is valid at all temperatures with remarkable accuracy. All thermodynamical properties of classical ideal gases can be deduced from this relation at arbitrary temperature.

  1. X3 expansion tube driver gas spectroscopy and temperature measurements

    Science.gov (United States)

    Parekh, V.; Gildfind, D.; Lewis, S.; James, C.

    2017-11-01

    The University of Queensland's X3 facility is a large, free-piston driven expansion tube used for super-orbital and high Mach number scramjet aerothermodynamic studies. During recent development of new scramjet test flow conditions, experimentally measured shock speeds were found to be significantly lower than that predicted by initial driver performance calculations. These calculations were based on ideal, isentropic compression of the driver gas and indicated that loss mechanisms, not accounted for in the preliminary analysis, were significant. The critical determinant of shock speed is peak driver gas sound speed, which for a given gas composition depends on the peak driver gas temperature. This temperature may be inaccurately estimated if an incorrect fill temperature is assumed, or if heat losses during driver gas compression are significant but not accounted for. For this study, the ideal predicted peak temperature was 3750 K, without accounting for losses. However, a much lower driver temperature of 2400 K is suggested based on measured experimental shock speeds. This study aimed to measure initial and peak driver gas temperatures for a representative X3 operating condition. Examination of the transient temperatures of the driver gas and compression tube steel wall during the initial fill process showed that once the filling process was complete, the steady-state driver gas temperature closely matched the tube wall temperature. Therefore, while assuming the gas is initially at the ambient laboratory temperature is not a significant source of error, it can be entirely mitigated by simply monitoring tube wall temperature. Optical emission spectroscopy was used to determine the driver gas spectra after diaphragm rupture; the driver gas emission spectrum exhibited a significant continuum radiation component, with prominent spectral lines attributed to contamination of the gas. A graybody approximation of the continuum suggested a peak driver gas temperature of

  2. X3 expansion tube driver gas spectroscopy and temperature measurements

    Science.gov (United States)

    Parekh, V.; Gildfind, D.; Lewis, S.; James, C.

    2018-07-01

    The University of Queensland's X3 facility is a large, free-piston driven expansion tube used for super-orbital and high Mach number scramjet aerothermodynamic studies. During recent development of new scramjet test flow conditions, experimentally measured shock speeds were found to be significantly lower than that predicted by initial driver performance calculations. These calculations were based on ideal, isentropic compression of the driver gas and indicated that loss mechanisms, not accounted for in the preliminary analysis, were significant. The critical determinant of shock speed is peak driver gas sound speed, which for a given gas composition depends on the peak driver gas temperature. This temperature may be inaccurately estimated if an incorrect fill temperature is assumed, or if heat losses during driver gas compression are significant but not accounted for. For this study, the ideal predicted peak temperature was 3750 K, without accounting for losses. However, a much lower driver temperature of 2400 K is suggested based on measured experimental shock speeds. This study aimed to measure initial and peak driver gas temperatures for a representative X3 operating condition. Examination of the transient temperatures of the driver gas and compression tube steel wall during the initial fill process showed that once the filling process was complete, the steady-state driver gas temperature closely matched the tube wall temperature. Therefore, while assuming the gas is initially at the ambient laboratory temperature is not a significant source of error, it can be entirely mitigated by simply monitoring tube wall temperature. Optical emission spectroscopy was used to determine the driver gas spectra after diaphragm rupture; the driver gas emission spectrum exhibited a significant continuum radiation component, with prominent spectral lines attributed to contamination of the gas. A graybody approximation of the continuum suggested a peak driver gas temperature of

  3. Novel silica membranes for high temperature gas separations

    KAUST Repository

    Bighane, Neha; Koros, William J.

    2011-01-01

    and pure gas separation performance in the temperature range 35-80°C is presented. It is observed that the membranes exhibit activated transport for small gas penetrants such as He, H 2 and CO 2. The membranes can withstand temperatures up to 350°C in air

  4. Moderator clean-up system in a heavy water reactor

    International Nuclear Information System (INIS)

    Sasada, Yasuhiro; Hamamura, Kenji.

    1983-01-01

    Purpose: To decrease the fluctuation of the poison concentration in heavy water moderator due to a heavy water clean-up system. Constitution: To a calandria tank filled with heavy water as poison-containing moderators, are connected both end of a pipeway through which heavy water flows and to which a clean-up device is provided. Strongly basic resin is filled within the clean-up device and a cooler is disposed to a pipeway at the upstream of the clean-up device. In this structure, the temperature of heavy water at the inlet of the clean-up device at a constant level between the temperature at the exit of the cooler and the lowest temperature for the moderator to thereby decrease the fluctuation in the poison concentration in the heavy water moderator due to the heavy water clean-up device. (Moriyama, K.)

  5. Pilot plant experience in electron-beam treatment of iron-ore sintering flue gas and its application to coal boiler flue gas cleanup

    International Nuclear Information System (INIS)

    Kawamura, K.

    1984-01-01

    The present development status of the electron-beam flue gas treatment process, which is a dry process capable of removing SOx and NOx simultaneously, is described. The most advanced demonstration of this process was accomplished with a pilot plant in Japan where the maximum gas flow rate of 10,000 Nm 3 /h of an iron-ore sintering machine flue gas was successfully treated. The byproduct produced in this process is collected as a dry powder which is a mixture of ammonia sulfate and ammonium nitrate and is saleable as a fertilizer or a fertilizer component. A preliminary economic projection showed that this process costs less than the lime scrubber which removes SOx but does not remove NOx. Tests using simulated coal combustion gases suggest that this process will be applicable to coal-fired boiler flue gas treatment as well. However, tests on actual coal-fired flue gases are still required for commercial application decisions. A process development unit program consisting of the design, construction and testing of actual coal-fired power station flue gases is underway in the U.S.A. The design and engineering of the test plant is far advanced and the construction phase will be launched in the very near future. (author)

  6. Measured gas and particle temperatures in VTT's entrained flow reactor

    DEFF Research Database (Denmark)

    Clausen, Sønnik; Sørensen, L.H.

    2006-01-01

    Particle and gas temperature measurements were carried out in experiments on VTTs entrained flow reactor with 5% and 10% oxygen using Fourier transform infrared emission spectroscopy (FTIR). Particle temperature measurements were performed on polish coal,bark, wood, straw particles, and bark...... and wood particles treated with additive. A two-color technique with subtraction of the background light was used to estimate particle temperatures during experiments. A transmission-emission technique was used tomeasure the gas temperature in the reactor tube. Gas temperature measurements were in good...... agreement with thermocouple readings. Gas lines and bands from CO, CO2 and H2O can be observed in the spectra. CO was only observed at the first measuring port (100ms) with the strongest CO-signal seen during experiments with straw particles. Variations in gas concentration (CO2 and H2O) and the signal from...

  7. Molybdenum-based additives to mixed-metal oxides for use in hot gas cleanup sorbents for the catalytic decomposition of ammonia in coal gases

    Science.gov (United States)

    Ayala, Raul E.

    1993-01-01

    This invention relates to additives to mixed-metal oxides that act simultaneously as sorbents and catalysts in cleanup systems for hot coal gases. Such additives of this type, generally, act as a sorbent to remove sulfur from the coal gases while substantially simultaneously, catalytically decomposing appreciable amounts of ammonia from the coal gases.

  8. Temperature monitoring of gas-cooled reactors

    International Nuclear Information System (INIS)

    Kaiser, G.E.

    1977-01-01

    The present paper deals with questions like : a) Why temperature monitoring in high-temperature reactors at all. b) How are the measuring positions arranged and how are the measurements designed. c) What technique of temperature measurement is applied. (RW) [de

  9. Cleanups in My Community

    Data.gov (United States)

    U.S. Environmental Protection Agency — Cleanups in My Community (CIMC) is a public web application that enables integrated access through maps, lists and search filtering to site-specific information EPA...

  10. Apparatus using radioactive particles for measuring gas temperatures

    International Nuclear Information System (INIS)

    Compton, W.A.; Duffy, T.E.; Seegall, M.I.

    1975-01-01

    Apparatus for producing a signal indicative of the temperature of a heated gas is described comprising a beta particle source; a beta particle detector which intercepts particles emitted from said source; circuitry for converting the detector output to a signal indicative of the density of the gas; a pressure transducer for generating a signal indicative of the pressure on the gas; and circuitry for dividing the pressure signal by the density signal to produce a signal indicative of the average temperature of the gas along the path between the beta particle source and the beta particle detector. (auth)

  11. Novel silica membranes for high temperature gas separations

    KAUST Repository

    Bighane, Neha

    2011-04-01

    This article describes fabrication of novel silica membranes derived via controlled oxidative thermolysis of polydimethylsiloxane and their gas separation performance. The optimized protocol for fabrication of the silica membranes is described and pure gas separation performance in the temperature range 35-80°C is presented. It is observed that the membranes exhibit activated transport for small gas penetrants such as He, H 2 and CO 2. The membranes can withstand temperatures up to 350°C in air and may ultimately find use in H 2/CO 2 separations to improve efficiency in the water-gas shift reactor process. © 2011 Elsevier B.V.

  12. Method for high temperature mercury capture from gas streams

    Science.gov (United States)

    Granite, Evan J [Wexford, PA; Pennline, Henry W [Bethel Park, PA

    2006-04-25

    A process to facilitate mercury extraction from high temperature flue/fuel gas via the use of metal sorbents which capture mercury at ambient and high temperatures. The spent sorbents can be regenerated after exposure to mercury. The metal sorbents can be used as pure metals (or combinations of metals) or dispersed on an inert support to increase surface area per gram of metal sorbent. Iridium and ruthenium are effective for mercury removal from flue and smelter gases. Palladium and platinum are effective for mercury removal from fuel gas (syngas). An iridium-platinum alloy is suitable for metal capture in many industrial effluent gas streams including highly corrosive gas streams.

  13. Enabling cleanup technology transfer

    International Nuclear Information System (INIS)

    Ditmars, J. D.

    2002-01-01

    Technology transfer in the environmental restoration, or cleanup, area has been challenging. While there is little doubt that innovative technologies are needed to reduce the times, risks, and costs associated with the cleanup of federal sites, particularly those of the Departments of Energy (DOE) and Defense, the use of such technologies in actual cleanups has been relatively limited. There are, of course, many reasons why technologies do not reach the implementation phase or do not get transferred from developing entities to the user community. For example, many past cleanup contracts provided few incentives for performance that would compel a contractor to seek improvement via technology applications. While performance-based contracts are becoming more common, they alone will not drive increased technology applications. This paper focuses on some applications of cleanup methodologies and technologies that have been successful and are illustrative of a more general principle. The principle is at once obvious and not widely practiced. It is that, with few exceptions, innovative cleanup technologies are rarely implemented successfully alone but rather are implemented in the context of enabling processes and methodologies. And, since cleanup is conducted in a regulatory environment, the stage is better set for technology transfer when the context includes substantive interactions with the relevant stakeholders. Examples of this principle are drawn from Argonne National Laboratory's experiences in Adaptive Sampling and Analysis Programs (ASAPs), Precise Excavation, and the DOE Technology Connection (TechCon) Program. The lessons learned may be applicable to the continuing challenges posed by the cleanup and long-term stewardship of radioactive contaminants and unexploded ordnance (UXO) at federal sites

  14. A new algorithm predicts pressure and temperature profiles of gas/gas-condensate transmission pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Mokhatab, Saied [OIEC - Oil Industries' Engineering and Construction Group, Tehran (Iran, Islamic Republic of); Vatani, Ali [University of Tehran (Iran, Islamic Republic of)

    2003-07-01

    The main objective of the present study has been the development of a relatively simple analytical algorithm for predicting flow temperature and pressure profiles along the two-phase, gas/gas-condensate transmission pipelines. Results demonstrate the ability of the method to predict reasonably accurate pressure gradient and temperature gradient profiles under operating conditions. (author)

  15. Gas temperature of capacitance spark discharge in air

    International Nuclear Information System (INIS)

    Ono, Ryo; Nifuku, Masaharu; Fujiwara, Shuzo; Horiguchi, Sadashige; Oda, Tetsuji

    2005-01-01

    Capacitance spark discharge has been widely used for studying the ignition of flammable gas caused by electrostatic discharge. In the present study, the gas temperature of capacitance spark discharge is measured. The gas temperature is an important factor in understanding the electrostatic ignition process because it influences the reaction rate of ignition. Spark discharge is generated in air with a pulse duration shorter than 100 ns. The discharge energy is set to 0.03-1 mJ. The rotational and vibrational temperatures of the N 2 molecule are measured using the emission spectrum of the N 2 second positive system. The rotational and vibrational temperatures are estimated to be 500 and 5000 K, respectively, which are independent of the discharge energy. This result indicates that most of the electron energy is consumed in the excitation of vibrational levels of molecules rather than the heating of the gas. The gas temperature after discharge is also measured by laser-induced fluorescence of OH radicals. It is shown that the gas temperature increases after discharge and reaches approximately 1000 K at 3 μs after discharge. Then the temperature decreases at a rate in the range of 8-35 K/μs depending on the discharge energy

  16. Fuel arrangement for high temperature gas cooled reactor

    International Nuclear Information System (INIS)

    Tobin, J.M.

    1978-01-01

    Disclosed is a fuel arrangement for a high temperature gas cooled reactor including fuel assemblies with separate directly cooled fissile and fertile fuel elements removably inserted in an elongated moderator block also having a passageway for control elements

  17. The temperature distribution in a gas core fission reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hoogenboom, J.E.; Dam, H. van; Kuijper, J.C. (Interuniversitair Reactor Inst., Delft (Netherlands)); Kistemaker, J.; Boersma-Klein, W.; Vitalis, F. (FOM-Instituut voor Atoom-en Molecuulfysica, Amsterdam (Netherlands))

    1991-01-01

    A model is proposed for the heat transport in a nuclear reactor with gaseous fuel at high temperatures taking into account radiative and kinetic heat transfer. A derivation is given of the equation determining the temperature distribution in a gas core reactor and different numerical solution methods are discussed in detail. Results are presented of the temperature distribution. The influence of the kinetic heat transport and of dissociation of the gas molecules is shown. Also discussed is the importance of the temperature gradient at the reactor wall and its dependence on system parameters. (author).

  18. The temperature distribution in a gas core fission reactor

    International Nuclear Information System (INIS)

    Hoogenboom, J.E.; Dam, H. van; Kuijper, J.C.; Kistemaker, J.; Boersma-Klein, W.; Vitalis, F.

    1991-01-01

    A model is proposed for the heat transport in a nuclear reactor with gaseous fuel at high temperatures taking into account radiative and kinetic heat transfer. A derivation is given of the equation determining the temperature distribution in a gas core reactor and different numerical solution methods are discussed in detail. Results are presented of the temperature distribution. The influence of the kinetic heat transport and of dissociation of the gas molecules is shown. Also discussed is the importance of the temperature gradient at the reactor wall and its dependence on system parameters. (author)

  19. Analysis and improvement of gas turbine blade temperature measurement error

    International Nuclear Information System (INIS)

    Gao, Shan; Wang, Lixin; Feng, Chi; Daniel, Ketui

    2015-01-01

    Gas turbine blade components are easily damaged; they also operate in harsh high-temperature, high-pressure environments over extended durations. Therefore, ensuring that the blade temperature remains within the design limits is very important. In this study, measurement errors in turbine blade temperatures were analyzed, taking into account detector lens contamination, the reflection of environmental energy from the target surface, the effects of the combustion gas, and the emissivity of the blade surface. In this paper, each of the above sources of measurement error is discussed, and an iterative computing method for calculating blade temperature is proposed. (paper)

  20. Analysis and improvement of gas turbine blade temperature measurement error

    Science.gov (United States)

    Gao, Shan; Wang, Lixin; Feng, Chi; Daniel, Ketui

    2015-10-01

    Gas turbine blade components are easily damaged; they also operate in harsh high-temperature, high-pressure environments over extended durations. Therefore, ensuring that the blade temperature remains within the design limits is very important. In this study, measurement errors in turbine blade temperatures were analyzed, taking into account detector lens contamination, the reflection of environmental energy from the target surface, the effects of the combustion gas, and the emissivity of the blade surface. In this paper, each of the above sources of measurement error is discussed, and an iterative computing method for calculating blade temperature is proposed.

  1. Fast temperature programming in gas chromatography using resistive heating

    NARCIS (Netherlands)

    Dallüge, J.; Ou-Aissa, R.; Vreuls, J.J.; Brinkman, U.A.T.; Veraart, J.R.

    1999-01-01

    The features of a resistive-heated capillary column for fast temperature-programmed gas chromatography (GC) have been evaluated. Experiments were carried out using a commercial available EZ Flash GC, an assembly which can be used to upgrade existing gas chromatographs. The capillary column is placed

  2. In situ gas temperature measurements by UV-absorption spectroscopy

    DEFF Research Database (Denmark)

    Fateev, Alexander; Clausen, Sønnik

    2009-01-01

    The absorption spectrum of the NO A(2)Sigma(+) uniform and stable gas temperatures over a 0.533 m path....... The accuracy of both methods is discussed. Validation of the classical Lambert-Beer law has been demonstrated at NO concentrations up to 500 ppm and gas temperatures up to 1,500 degrees C over an optical absorption path length of 0.533 m....

  3. Development history of the gas turbine modular high temperature reactor

    International Nuclear Information System (INIS)

    Brey, H.L.

    2001-01-01

    The development of the high temperature gas cooled reactor (HTGR) as an environmentally agreeable and efficient power source to support the generation of electricity and achieve a broad range of high temperature industrial applications has been an evolutionary process spanning over four decades. This process has included ongoing major development in both the HTGR as a nuclear energy source and associated power conversion systems from the steam cycle to the gas turbine. This paper follows the development process progressively through individual plant designs from early research of the 1950s to the present focus on the gas turbine modular HTGR. (author)

  4. A Smart Gas Sensor Insensitive to Humidity and Temperature Variations

    International Nuclear Information System (INIS)

    Hajmirzaheydarali, Mohammadreza; Ghafarinia, Vahid

    2011-01-01

    The accuracy of the quantitative sensing of volatile organic compounds by chemoresistive gas sensors suffers from the fluctuations in the background atmospheric conditions. This is caused by the drift-like terms introduced in the responses by these instabilities, which should be identified and compensated. Here, a mathematical model is presented for a specific chemoresistive gas sensor, which facilitates these identification and compensation processes. The resistive gas sensor was considered as a multi-input-single-output system. Along with the steady state value of the measured sensor resistance, the ambient humidity and temperature are the inputs to the system, while the concentration level of the target gas is the output. The parameters of the model were calculated based on the experimental database. The model was simulated by the utilization of an artificial neural network. This was connected to the sensor and could deliver the correct contamination level upon receiving the measured gas response, ambient humidity and temperature.

  5. Cleanup of contaminated areas

    International Nuclear Information System (INIS)

    Beone, G.; Carbone, A.I.; Zagaroli, M.

    1989-01-01

    The paper deals with the problem of contaminated areas cleanup, in order to eliminate every possible damage for man safety and environment and to site recovery for some utilization, The first step of cleanup operation is site characterization, that is followed by a pianificazion activity for a better definition of staff qualification, technology to be used, protection and prevention instruments for the risks due to contaminants handling. The second section describes the different remedial technologies for contaminated sites. Remedial technologies may be divided into on-site/off-site and in-situ treatments, according to whether materials (waste, soil, water) are moved to another location or not, respectively. Finally, it is outlined that contaminated areas cleanup is a typical multidisciplinary activity because very different competences are required. (author)

  6. Sorters for soil cleanup

    International Nuclear Information System (INIS)

    Bramlitt, E.T.; Johnson, N.R.; Tomicich, M.J.

    1991-01-01

    A soil sorter is a system with conveyor, radiation detectors, and a gate. The system activates the gate based on radiation measurements to sort soil to either clean or contaminated paths. Automatic soil sorters have been perfected for use in the cleanup of plutonium contaminated soil at Johnston Atoll. The cleanup processes soil through a plant which mines plutonium to make soil clean. Sorters at various locations in the plant effectively reduce the volume of soil for mining and they aid in assuring clean soil meets guidelines

  7. Modern gas-based temperature and pressure measurements

    CERN Document Server

    Pavese, Franco

    2013-01-01

    This 2nd edition volume of Modern Gas-Based Temperature and Pressure Measurements follows the first publication in 1992. It collects a much larger set of information, reference data, and bibliography in temperature and pressure metrology of gaseous substances, including the physical-chemical issues related to gaseous substances. The book provides solutions to practical applications where gases are used in different thermodynamic conditions. Modern Gas-Based Temperature and Pressure Measurements, 2nd edition is the only comprehensive survey of methods for pressure measurement in gaseous media used in the medium-to-low pressure range closely connected with thermometry. It assembles current information on thermometry and manometry that involve the use of gaseous substances which are likely to be valid methods for the future. As such, it is an important resource for the researcher. This edition is updated through the very latest scientific and technical developments of gas-based temperature and pressure measurem...

  8. Measuring gas temperature during spin-exchange optical pumping process

    Science.gov (United States)

    Normand, E.; Jiang, C. Y.; Brown, D. R.; Robertson, L.; Crow, L.; Tong, X.

    2016-04-01

    The gas temperature inside a Spin-Exchange Optical Pumping (SEOP) laser-pumping polarized 3He cell has long been a mystery. Different experimental methods were employed to measure this temperature but all were based on either modelling or indirect measurement. To date there has not been any direct experimental measurement of this quantity. Here we present the first direct measurement using neutron transmission to accurately determine the number density of 3He, the temperature is obtained using the ideal gas law. Our result showed a surprisingly high gas temperature of 380°C, compared to the 245°C of the 3He cell wall temperature and 178°C of the optical pumping oven temperature. This experiment result may be used to further investigate the unsolved puzzle of the "X-factor" in the SEOP process which places an upper bound to the 3He polarization that can be achieved. Additional spin relaxation mechanisms might exist due to the high gas temperature, which could explain the origin of the X-factor.

  9. Design and development of gas turbine high temperature reactor 300

    International Nuclear Information System (INIS)

    Kunitomi, Kazuhiko; Katanishi, Shoji; Takada, Shoji; Yan, Xing; Takizuka, Takakazu

    2003-01-01

    JAERI (Japan Atomic Energy Research Institute) has been designing a Japan's original gas turbine high temperature reactor, GTHTR300 (Gas Turbine High Temperature Reactor 300). The greatly simplified design based on salient features of the HTGR (High Temperature Gas-cooled reactor) with a closed helium gas turbine enables the GTHTR300 a high efficient and economically competitive reactor to be deployed in early 2010s. Also, the GTHTR300 fully taking advantage of various experiences accumulated in design, construction and operation of the HTTR (High Temperature Engineering Test Reactor) and fossil gas turbine systems reduces technological development concerning a reactor system and electric generation system. Original features of this system are core design with two-year refueling interval, conventional steel material usage for a reactor pressure vessel, innovative plant flow scheme and horizontally installed gas turbine unit. Due to these salient features, the capital cost of the GTHTR300 is less than a target cost of 200 thousands Yen/kWe, and the electric generation cost is close to a target cost of 4 Yen/kWh. This paper describes the original design features focusing on reactor core design, fuel design, in-core structure design and reactor pressure vessel design except PCU design. Also, R and D for developing the power conversion unit is briefly described. The present study is entrusted from the Ministry of Education, Culture, Sports, Science and Technology of Japan. (author)

  10. Environmental compliance and cleanup

    Energy Technology Data Exchange (ETDEWEB)

    Black, D.G.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the roles of the principal agencies, organizations, and public in environmental compliance and cleanup of the Hanford Site. Regulatory oversight, the Federal Facility Agreement and Consent Order, the role of Indian tribes, public participation, and CERCLA Natural Resource Damage Assessment Trustee Activities are all discussed.

  11. Environmental compliance and cleanup

    International Nuclear Information System (INIS)

    Black, D.G.

    1995-01-01

    This section of the 1994 Hanford Site Environmental Report summarizes the roles of the principal agencies, organizations, and public in environmental compliance and cleanup of the Hanford Site. Regulatory oversight, the Federal Facility Agreement and Consent Order, the role of Indian tribes, public participation, and CERCLA Natural Resource Damage Assessment Trustee Activities are all discussed

  12. Determination of gas temperature in the plasmatron channel according to the known distribution of electronic temperature

    Directory of Open Access Journals (Sweden)

    Gerasimov Alexander V.

    2013-01-01

    Full Text Available An analytical method to calculate the temperature distribution of heavy particles in the channel of the plasma torch on the known distribution of the electronic temperature has been proposed. The results can be useful for a number of model calculations in determining the most effective conditions of gas blowing through the plasma torch with the purpose of heating the heavy component. This approach allows us to understand full details about the heating of cold gas, inpouring the plasma, and to estimate correctly the distribution of the gas temperature inside the channel.

  13. Multi-spectral temperature measurement method for gas turbine blade

    Science.gov (United States)

    Gao, Shan; Feng, Chi; Wang, Lixin; Li, Dong

    2016-02-01

    One of the basic methods to improve both the thermal efficiency and power output of a gas turbine is to increase the firing temperature. However, gas turbine blades are easily damaged in harsh high-temperature and high-pressure environments. Therefore, ensuring that the blade temperature remains within the design limits is very important. There are unsolved problems in blade temperature measurement, relating to the emissivity of the blade surface, influences of the combustion gases, and reflections of radiant energy from the surroundings. In this study, the emissivity of blade surfaces has been measured, with errors reduced by a fitting method, influences of the combustion gases have been calculated for different operational conditions, and a reflection model has been built. An iterative computing method is proposed for calculating blade temperatures, and the experimental results show that this method has high precision.

  14. High temperature gas dynamics an introduction for physicists and engineers

    CERN Document Server

    Bose, Tarit K

    2014-01-01

    High Temperature Gas Dynamics is a primer for scientists, engineers, and students who would like to have a basic understanding of the physics and the behavior of high-temperature gases. It is a valuable tool for astrophysicists as well. The first chapters treat the basic principles of quantum and statistical mechanics and how to derive thermophysical properties from them. Special topics are included that are rarely found in other textbooks, such as the thermophysical and transport properties of multi-temperature gases and a novel method to compute radiative transfer. Furthermore, collision processes between different particles are discussed. Separate chapters deal with the production of high-temperature gases and with electrical emission in plasmas, as well as related diagnostic techniques.This new edition adds over 100 pages and includes the following updates: several sections on radiative properties of high temperature gases and various radiation models, a section on shocks in magneto-gas-dynamics, a sectio...

  15. Simultaneous determination of multiresidual phenyl acetanilide pesticides in different food commodities by solid-phase cleanup and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Li, Yongjun; Wang, Meiling; Yan, Hongfei; Fu, Shanliang; Dai, Hua

    2013-03-01

    An efficient and sensitive multiresidue method has been developed for quantification and confirmation of 25 phenyl acetanilide pesticides in a wide variety of food commodities including maize, spinach, mushroom, apple, soybean, chestnut, tea, beef, cattle liver, chicken, fish, and milk. Analytes were extracted with acetone-n-hexane (1:2, v/v) followed by cleanup using SPE. Several types of adsorbents were evaluated. Neutral aluminum and graphitized carbon black cartridge showed good cleanup efficiency. The extract was determined by GC-MS in the selected ion monitoring mode using one target and two qualitative ions for each analyte. The limits of detection were 0.01 mg/kg for all analytes. The average recoveries ranged from 66.9 to 110.6% (mean 88.8%) and RSDs were in the range 2.0-19% (mean 10.5%) across three fortification levels. The proposed method was successfully applied to real samples in routine analysis and a satisfactory result was obtained. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Clean-up of aqueous acetone vegetable extracts by solid-matrix partition for pyrethroid residue determination by gas chromatography-electron-capture detection.

    Science.gov (United States)

    Di Muccio, A; Barbini, D A; Generali, T; Pelosi, P; Ausili, A; Vergori, F; Camoni, I

    1997-03-21

    Disposable, ready-to-use cartridges filled with macroporous diatomaceous material are used to carry out a partition clean-up that, in a single step, is capable of transferring pesticide residues from aqueous acetone extracts into light petroleum-dichloromethane (75:25, v/v). This procedure takes the place of some functions (such as separatory-funnel partition, drying over anhydrous sodium sulphate and partial adsorption clean-up) usually performed by separate steps in classical schemes. Fourteen pyrethroid pesticides, including tefluthrin, tetramethrin, cyphenothrin, cyfluthrin, flucythrinate, tau-fluvalinate, deltamethrin, bioallethrin, fenpropathrin, lambda-cyhalothrin, permethrin, alpha-cypermethrin, esfenvalerate and tralomethrin were determined using the described procedure with satisfactory recoveries for most of them, at spiking levels ranging from 0.08 to 0.82 mg/kg for the different compounds. Crops subjected to the described procedure included strawberry, apple, and orange gave extracts containing a mass of co-extractives that was between 5 and 30 mg. Compared with classical schemes, the described procedure is simple, less labour intensive, allows parallel handling of several extracts and does not require the preparation and maintenance of equipment. Troublesome emulsions such as those frequently observed in separation funnel partitioning do not occur.

  17. Gravitational collapse of a magnetized fermion gas with finite temperature

    Energy Technology Data Exchange (ETDEWEB)

    Delgado Gaspar, I. [Instituto de Geofisica y Astronomia (IGA), La Habana (Cuba); Perez Martinez, A. [Instituto de Cibernetica, Matematica y Fisica (ICIMAF), La Habana (Cuba); Sussman, Roberto A. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (ICN-UNAM), Mexico (Mexico); Ulacia Rey, A. [Instituto de Cibernetica, Matematica y Fisica (ICIMAF), La Habana (Cuba); Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (ICN-UNAM), Mexico (Mexico)

    2013-07-15

    We examine the dynamics of a self-gravitating magnetized fermion gas at finite temperature near the collapsing singularity of a Bianchi-I spacetime. Considering a general set of appropriate and physically motivated initial conditions, we transform Einstein-Maxwell field equations into a complete and self-consistent dynamical system amenable for numerical work. The resulting numerical solutions reveal the gas collapsing into both, isotropic (''point-like'') and anisotropic (''cigar-like''), singularities, depending on the initial intensity of the magnetic field. We provide a thorough study of the near collapse behavior and interplay of all relevant state and kinematic variables: temperature, expansion scalar, shear scalar, magnetic field, magnetization, and energy density. A significant qualitative difference in the behavior of the gas emerges in the temperature range T/m{sub f} {proportional_to} 10{sup -6} and T/m{sub f} {proportional_to} 10{sup -3}. (orig.)

  18. Elevated temperature and high pressure large helium gas loop

    International Nuclear Information System (INIS)

    Sakasai, Minoru; Midoriyama, Shigeru; Miyata, Toyohiko; Nakase, Tsuyoshi; Izaki, Makoto

    1979-01-01

    The development of high temperature gas-cooled reactors especially aiming at the multi-purpose utilization of nuclear heat energy is carried out actively in Japan and West Germany. In Japan, the experimental HTGR of 50 MWt and 1000 deg C outlet temperature is being developed by Japan Atomic Energy Research Institute and others since 1969, and the development of direct iron-making technology utilizing high temperature reducing gas was started in 1973 as the large project of Ministry of Internalional Trade and Industry. Kawasaki Heavy Industries, Ltd., Has taken part in these development projects, and has developed many softwares for nuclear heat design, system design and safety design of nuclear reactor system and heat utilization system. In hardwares also, efforts have been exerted to develop the technologies of design and manufacture of high temperature machinery and equipments. The high temperature, high pressure, large helium gas loop is under construction in the technical research institute of the company, and it is expected to be completed in December, 1979. The tests planned are that of proving the dynamic performances of the loop and its machinery and equipments and the verification of analysis codes. The loop is composed of the main circulation system, the objects of testing, the helium gas purifying system, the helium supplying and evacuating system, instruments and others. (Kako, I.)

  19. Microstructural Characterization of Low Temperature Gas Nitrided Martensitic Stainless Steel

    DEFF Research Database (Denmark)

    Fernandes, Frederico Augusto Pires; Christiansen, Thomas Lundin; Somers, Marcel A. J.

    2015-01-01

    The present work presents microstructural investigations of the surface zone of low temperature gas nitrided precipitation hardening martensitic stainless steel AISI 630. Grazing incidence X-ray diffraction was applied to investigate the present phases after successive removal of very thin sections...... of the sample surface. The development of epsilon nitride, expanded austenite and expanded martensite resulted from the low temperature nitriding treatments. The microstructural features, hardness and phase composition are discussed with emphasis on the influence of nitriding duration and nitriding potential....

  20. A review of helium gas turbine technology for high-temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    No, Hee Cheon; Kim, Ji Hwan; Kim, Hyeun Min

    2007-01-01

    Current High-Temperature Gas-cooled Reactors (HTGRs) are based on a closed brayton cycle with helium gas as the working fluid. Thermodynamic performance of the axial-flow helium gas turbines is of critical concern as it considerably affects the overall cycle efficiency. Helium gas turbines pose some design challenges compared to steam or air turbomachinery because of the physical properties of helium and the uniqueness of the operating conditions at high pressure with low pressure ratio. This report present a review of the helium Brayton cycle experiences in Germany and in Japan. The design and availability of helium gas turbines for HTGR are also presented in this study. We have developed a new throughflow calculation code to calculate the design-point performance of helium gas turbines. Use of the method has been illustrated by applying it to the GTHTR300 reference

  1. Influence of different storage times and temperatures on blood gas ...

    African Journals Online (AJOL)

    The present study was designed to investigate the effects of storage temperature and time on blood gas and acid-base balance of ovine venous blood. Ten clinically healthy sheep were used in this study. A total number of 30 blood samples, were divided into three different groups, and were stored in a refrigerator adjusted ...

  2. Anisotropic ordering in a two-temperature lattice gas

    DEFF Research Database (Denmark)

    Szolnoki, Attila; Szabó, György; Mouritsen, Ole G.

    1997-01-01

    We consider a two-dimensional lattice gas model with repulsive nearest- and next-nearest-neighbor interactions that evolves in time according to anisotropic Kawasaki dynamics. The hopping of particles along the principal directions is governed by two heat baths at different temperatures T-x and T...

  3. Magnetic resonance studies of atomic hydrogen gas at low temperatures

    International Nuclear Information System (INIS)

    Hardy, W.N.; Morrow, M.; Jochemsen, R.; Statt, B.W.; Kubik, P.R.; Marsolais, R.M.; Berlinsky, A.J.; Landesman, A.

    1980-01-01

    Using a pulsed low temperature discharge in a closed cell containing H 2 and 4 He, we have been able to store a low density (approximately 10 12 atoms/cc) gas of atomic hydrogen for periods of order one hour in zero magnetic field and T=1 K. Pulsed magnetic resonance at the 1420 MHz hyperfine transition has been used to study a number of the properties of the gas, including the recombination rate H + H + 4 He→H 2 + 4 He, the hydrogen spin-exchange relaxation rates, the diffusion coefficient of H in 4 He gas and the pressure shift of the hyperfine frequency due to the 4 He buffer gas. Here we discuss the application of hyperfine frequency shifts as a probe of the H-He potential, and as a means for determining the binding energy of H on liquid helium

  4. Low temperature catalytic combustion of natural gas - hydrogen - air mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Newson, E; Roth, F von; Hottinger, P; Truong, T B [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The low temperature catalytic combustion of natural gas - air mixtures would allow the development of no-NO{sub x} burners for heating and power applications. Using commercially available catalysts, the room temperature ignition of methane-propane-air mixtures has been shown in laboratory reactors with combustion efficiencies over 95% and maximum temperatures less than 700{sup o}C. After a 500 hour stability test, severe deactivation of both methane and propane oxidation functions was observed. In cooperation with industrial partners, scaleup to 3 kW is being investigated together with startup dynamics and catalyst stability. (author) 3 figs., 3 refs.

  5. Determining noncondensible gas fractions at elevated temperatures and pressures using wet and dry bulb temperature measurements

    International Nuclear Information System (INIS)

    Griffith, P.; Bowman, J.

    1987-01-01

    The work reported in this note was undertaken to provide a method of determining the noncondensible gas fractions in a steam-gas mixture such as might be found in large reactor safety experiment like LOFT. In essence, the method used involves measuring the wet and dry bulb temperatures and using an algorithm, in place of the psychometric chart, to determine the partial pressure of the noncondensible gas in the mixture. In accomplishing this, the authors did the following: (1) extended the use of wet and dry-bulb temperature readings to determine mixture composition up to a temperature of 589 K and a pressure of 4.13 x 10 6 Pa. (2) developed an algorithm to reduce the data (3) found which materials would survive those temperatures

  6. Copper clean-up procedure for ultrasonic extraction and analysis of pyrethroid and phenylpyrazole pesticides in sediments by gas chromatography-electron capture detection

    International Nuclear Information System (INIS)

    Wu Jun; Lin Youjian; Lu Jian; Wilson, Chris

    2011-01-01

    A rapid ultrasonic extraction method coupled with a heated-copper clean-up procedure for removing interfering constituents was developed for analyzing pyrethroid and phenylpyrazole pesticides in sediments. Incubation of the 60 mL extract with 12 g copper granules at 60 o C for 2 h was determined to be the optimal conditions for removing the interfering constituents. Eleven pyrethroid and phenylpyrazole pesticides were spiked into sediment samples to determine the effectiveness of the ultrasonic extraction method. The average recoveries of pyrethroids and phenylpyrazoles in sediment at 4 o C storage on day 0, 1, 7, 14, and 21 ranged from 98.6 to 120.0%, 79.2 to 116.0%, 85.0 to 119.7%, 93.6 to 118.7%, and 92.1 to 118.2%, respectively, with all percent relative standard deviations less than 10% (most o C. Recoveries of the pesticides ranged from 98.6% to 120.0% for lowest fortification level (2-16 μg kg -1 ), from 97.8% to 117.9% for middle fortification level (10-80 μg kg -1 ), and from 94.3% to 118.1% for highest fortification level (20-160 μg kg -1 ). Relative standard deviations of pesticide recoveries were usually less than 7%. Method detection limits of target pesticides ranged from 0.22 μg kg -1 to 3.72 μg kg -1 . Furthermore, field sediment samples collected from four residential lakes during a three-month monitoring period were analyzed to evaluate the effectiveness of this method. Bifenthrin was detected in all of sediment samples (highest concentration 260.33 ± 41.71 μg kg -1 , lowest concentration 5.68 ± 0.38 μg kg -1 ), and fipronil sulfone was detected at least once in sediment samples collected from three sites with concentrations ranging from 1.73 ± 0.53 to 7.53 ± 0.01 μg kg -1 . - Highlights: → A rapid extraction and copper-based clean-up method was developed. → Recoveries after storage at 4 o C for 21 d ranged from 79.2 to 120.0%. → Percent relative standard deviations less than 10% (most -1 to 3.72 μg kg -1 .

  7. Miniaturized Planar Room Temperature Ionic Liquid Electrochemical Gas Sensor for Rapid Multiple Gas Pollutants Monitoring.

    Science.gov (United States)

    Wan, Hao; Yin, Heyu; Lin, Lu; Zeng, Xiangqun; Mason, Andrew J

    2018-02-01

    The growing impact of airborne pollutants and explosive gases on human health and occupational safety has escalated the demand of sensors to monitor hazardous gases. This paper presents a new miniaturized planar electrochemical gas sensor for rapid measurement of multiple gaseous hazards. The gas sensor features a porous polytetrafluoroethylene substrate that enables fast gas diffusion and room temperature ionic liquid as the electrolyte. Metal sputtering was utilized for platinum electrodes fabrication to enhance adhesion between the electrodes and the substrate. Together with carefully selected electrochemical methods, the miniaturized gas sensor is capable of measuring multiple gases including oxygen, methane, ozone and sulfur dioxide that are important to human health and safety. Compared to its manually-assembled Clark-cell predecessor, this sensor provides better sensitivity, linearity and repeatability, as validated for oxygen monitoring. With solid performance, fast response and miniaturized size, this sensor is promising for deployment in wearable devices for real-time point-of-exposure gas pollutant monitoring.

  8. Temperature and distortion transients in gas tungsten-arc weldments

    International Nuclear Information System (INIS)

    Glickstein, S.S.; Friedman, E.

    1979-10-01

    An analysis and test program to develop a fundamental understanding of the gas tungsten-arc welding process has been undertaken at the Bettis Atomic Power Laboratory to develop techniques to determine and control the various welding parameters and weldment conditions so as to result in optimum weld response characteristics. These response characteristics include depth of penetration, weld bead configuration, weld bead sink and roll, distortion, and cracking sensitivity. The results are documented of that part of the program devoted to analytical and experimental investigations of temperatures, weld bead dimensions, and distortions for moving gas tungsten-arc welds applied to Alloy 600 plates

  9. Optimized Feature Extraction for Temperature-Modulated Gas Sensors

    Directory of Open Access Journals (Sweden)

    Alexander Vergara

    2009-01-01

    Full Text Available One of the most serious limitations to the practical utilization of solid-state gas sensors is the drift of their signal. Even if drift is rooted in the chemical and physical processes occurring in the sensor, improved signal processing is generally considered as a methodology to increase sensors stability. Several studies evidenced the augmented stability of time variable signals elicited by the modulation of either the gas concentration or the operating temperature. Furthermore, when time-variable signals are used, the extraction of features can be accomplished in shorter time with respect to the time necessary to calculate the usual features defined in steady-state conditions. In this paper, we discuss the stability properties of distinct dynamic features using an array of metal oxide semiconductors gas sensors whose working temperature is modulated with optimized multisinusoidal signals. Experiments were aimed at measuring the dispersion of sensors features in repeated sequences of a limited number of experimental conditions. Results evidenced that the features extracted during the temperature modulation reduce the multidimensional data dispersion among repeated measurements. In particular, the Energy Signal Vector provided an almost constant classification rate along the time with respect to the temperature modulation.

  10. Demonstrating practical application of soil and groundwater clean-up and recovery technologies at natural gas processing facilities: Bioventing, air sparging and wetlands remediation

    International Nuclear Information System (INIS)

    Moore, B.

    1996-01-01

    This issue of the project newsletter described the nature of bioventing, air sparging and wetland remediation. It reviewed their effectiveness in remediating hydrocarbon contaminated soil above the groundwater surface. Bioventing was described as an effective, low cost treatment in which air is pumped below ground to stimulate indigenous bacteria. The bacteria then use the oxygen to consume the hydrocarbons, converting them to CO 2 and water. Air sparging involves the injection of air below the groundwater surface. As the air rises, hydrocarbons are stripped from the contaminated soil and water. The advantage of air sparging is that it cleans contaminated soil and water from below the groundwater surface. Hydrocarbon contamination of wetlands was described as fairly common. Conventional remediation methods of excavation, trenching, and bellholes to remove contamination often cause extreme harm to the ecosystem. Recent experimental evidence suggests that wetlands may be capable of attenuating contaminated water through natural processes. Four hydrocarbon contaminated wetlands in Alberta are currently under study. Results to date show that peat's high organic content promotes sorption and biodegradation and that some crude oil spills can been resolved by natural processes. It was suggested that assuming peat is present, a good clean-up approach may be to contain the contaminant source, monitor the lateral and vertical extent of contamination, and wait for natural processes to resolve the problem. 3 figs

  11. IAEA high temperature gas-cooled reactor activities

    International Nuclear Information System (INIS)

    Kendall, J.M.

    2000-01-01

    The IAEA activities on high temperature gas-cooled reactors are conducted with the review and support of the Member states, primarily through the International Working Group on Gas-Cooled Reactors (IWG-GCR). This paper summarises the results of the IAEA gas-cooled reactor project activities in recent years along with ongoing current activities through a review of Co-ordinated Research Projects (CRPs), meetings and other international efforts. A series of three recently completed CRPs have addressed the key areas of reactor physics for LEU fuel, retention of fission products and removal of post shutdown decay heat through passive heat transport mechanisms. These activities along with other completed and ongoing supporting CRPs and meetings are summarised with reference to detailed documentation of the results. (authors)

  12. Gas diffusion and temperature dependence of bubble nucleation during irradiation

    DEFF Research Database (Denmark)

    Foreman, A. J. E.; Singh, Bachu Narain

    1986-01-01

    The continuous production of gases at relatively high rates under fusion irradiation conditions may enhance the nucleation of cavities. This can cause dimensional changes and could induce embrittlement arising from gas accumulation on grain boundaries. Computer calculations have been made...... of the diatomic nucleation of helium bubbles, assuming helium to diffuse substitutionally, with radiation-enhanced diffusion at lower temperatures. The calculated temperature dependence of the bubble density shows excellent agreement with that observed in 600 MeV proton irradiations, including a reduction...... in activation energy below Tm/2. The coalescence of diatomic nuclei due to Brownian motion markedly improves the agreement and also provides a well-defined terminal density. Bubble nucleation by this mechanism is sufficiently fast to inhibit any appreciable initial loss of gas to grain boundaries during...

  13. Power Conversion Study for High Temperature Gas-Cooled Reactors

    International Nuclear Information System (INIS)

    Chang Oh; Richard Moore; Robert Barner

    2005-01-01

    The Idaho National Laboratory (INL) is investigating a Brayton cycle efficiency improvement on a high temperature gas-cooled reactor (HTGR) as part of Generation-IV nuclear engineering research initiative. There are some technical issues to be resolved before the selection of the final design of the high temperature gas cooled reactor, called as a Next Generation Nuclear Plant (NGNP), which is supposed to be built at the INEEL by year 2017. The technical issues are the selection of the working fluid, direct vs. indirect cycle, power cycle type, the optimized design in terms of a number of intercoolers, and others. In this paper, we investigated a number of working fluids for the power conversion loop, direct versus indirect cycle, the effect of intercoolers, and other thermal hydraulics issues. However, in this paper, we present part of the results we have obtained. HYSYS computer code was used along with a computer model developed using Visual Basic computer language

  14. Titanium dioxide thin films for high temperature gas sensors

    Energy Technology Data Exchange (ETDEWEB)

    Seeley, Zachary Mark; Bandyopadhyay, Amit; Bose, Susmita, E-mail: sbose@wsu.ed

    2010-10-29

    Titanium dioxide (TiO{sub 2}) thin film gas sensors were fabricated via the sol-gel method from a starting solution of titanium isopropoxide dissolved in methoxyethanol. Spin coating was used to deposit the sol on electroded aluminum oxide (Al{sub 2}O{sub 3}) substrates forming a film 1 {mu}m thick. The influence of crystallization temperature and operating temperature on crystalline phase, grain size, electronic conduction activation energy, and gas sensing response toward carbon monoxide (CO) and methane (CH{sub 4}) was studied. Pure anatase phase was found with crystallization temperatures up to 800 {sup o}C, however, rutile began to form by 900 {sup o}C. Grain size increased with increasing calcination temperature. Activation energy was dependent on crystallite size and phase. Sensing response toward CO and CH{sub 4} was dependent on both calcination and operating temperatures. Films crystallized at 650 {sup o}C and operated at 450 {sup o}C showed the best selectivity toward CO.

  15. Properties of super alloys for high temperature gas cooled reactor

    International Nuclear Information System (INIS)

    Izaki, Takashi; Nakai, Yasuo; Shimizu, Shigeki; Murakami, Takashi

    1975-01-01

    The existing data on the properties at high temperature in helium gas of iron base super alloys. Incoloy-800, -802 and -807, nickel base super alloys, Hastelloy-X, Inconel-600, -617 and -625, and a casting alloy HK-40 were collectively evaluated from the viewpoint of the selection of material for HTGRs. These properties include corrosion resistance, strength and toughness, weldability, tube making, formability, radioactivation, etc. Creep strength was specially studied, taking into consideration the data on the creep characteristics in the actual helium gas atmosphere. The necessity of further long run creep data is suggested. Hastelloy-X has completely stable corrosion resistance at high temperature in helium gas. Incoloy 800 and 807 and Inconel 617 are not preferable in view of corrosion resistance. The creep strength of Inconel 617 extraporated to 1,000 deg C for 100,000 hours in air was the greatest rupture strength of 0.6 kg/mm 2 in all above alloys. However, its strength in helium gas began to fall during a relatively short time, so that its creep strength must be re-evaluated in the use for long time. The radioactivation and separation of oxide film in primary construction materials came into question, Inconel 617 and Incoloy 807 showed high induced radioactivity intensity. Generally speaking, in case of nickel base alloys such as Hastelloy-X, oxide film is difficult to break away. (Iwakiri, K.)

  16. High-Temperature Gas-Cooled Test Reactor Point Design

    Energy Technology Data Exchange (ETDEWEB)

    Sterbentz, James William [Idaho National Laboratory; Bayless, Paul David [Idaho National Laboratory; Nelson, Lee Orville [Idaho National Laboratory; Gougar, Hans David [Idaho National Laboratory; Kinsey, James Carl [Idaho National Laboratory; Strydom, Gerhard [Idaho National Laboratory; Kumar, Akansha [Idaho National Laboratory

    2016-04-01

    A point design has been developed for a 200 MW high-temperature gas-cooled test reactor. The point design concept uses standard prismatic blocks and 15.5% enriched UCO fuel. Reactor physics and thermal-hydraulics simulations have been performed to characterize the capabilities of the design. In addition to the technical data, overviews are provided on the technological readiness level, licensing approach and costs.

  17. Treatment of low-temperature tar-gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Schick, F

    1928-07-04

    Process for the treating and conversion of low-temperature tar-vapor and gas mixtures in the presence of metals or metal oxides as well as bodies of large surface, without previous condensation of the liquid material to be treated, characterized by the treatment taking place with a mixture of desulfurizing metals and metal oxides which, if necessary, are precipitated on carriers and large surface nonmetal cracking catalysts, such as active carbon and silica gel.

  18. Copper clean-up procedure for ultrasonic extraction and analysis of pyrethroid and phenylpyrazole pesticides in sediments by gas chromatography-electron capture detection

    Energy Technology Data Exchange (ETDEWEB)

    Wu Jun; Lin Youjian; Lu Jian; Wilson, Chris, E-mail: pcwilson@ufl.edu

    2011-08-15

    A rapid ultrasonic extraction method coupled with a heated-copper clean-up procedure for removing interfering constituents was developed for analyzing pyrethroid and phenylpyrazole pesticides in sediments. Incubation of the 60 mL extract with 12 g copper granules at 60 {sup o}C for 2 h was determined to be the optimal conditions for removing the interfering constituents. Eleven pyrethroid and phenylpyrazole pesticides were spiked into sediment samples to determine the effectiveness of the ultrasonic extraction method. The average recoveries of pyrethroids and phenylpyrazoles in sediment at 4 {sup o}C storage on day 0, 1, 7, 14, and 21 ranged from 98.6 to 120.0%, 79.2 to 116.0%, 85.0 to 119.7%, 93.6 to 118.7%, and 92.1 to 118.2%, respectively, with all percent relative standard deviations less than 10% (most < 6%). This illustrated the stability of pyrethroids and phenylpyrazoles in sediment during sediment aging at 4 {sup o}C. Recoveries of the pesticides ranged from 98.6% to 120.0% for lowest fortification level (2-16 {mu}g kg{sup -1}), from 97.8% to 117.9% for middle fortification level (10-80 {mu}g kg{sup -1}), and from 94.3% to 118.1% for highest fortification level (20-160 {mu}g kg{sup -1}). Relative standard deviations of pesticide recoveries were usually less than 7%. Method detection limits of target pesticides ranged from 0.22 {mu}g kg{sup -1} to 3.72 {mu}g kg{sup -1}. Furthermore, field sediment samples collected from four residential lakes during a three-month monitoring period were analyzed to evaluate the effectiveness of this method. Bifenthrin was detected in all of sediment samples (highest concentration 260.33 {+-} 41.71 {mu}g kg{sup -1}, lowest concentration 5.68 {+-} 0.38 {mu}g kg{sup -1}), and fipronil sulfone was detected at least once in sediment samples collected from three sites with concentrations ranging from 1.73 {+-} 0.53 to 7.53 {+-} 0.01 {mu}g kg{sup -1}. - Highlights: {yields} A rapid extraction and copper-based clean-up method was

  19. Utilizing the response patterns of a temperature modulated chemoresistive gas sensor for gas diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Amini, Amir [Jannatabad College, Sama Organization, Islamic Azad University, Tehran (Iran, Islamic Republic of); Ghafarinia, Vahid, E-mail: amir.amini.elec@gmail.com, E-mail: ghafarinia@ee.kntu.ac.ir [Electrical Engineering Department, K. N. Toosi University of Technology, Tehran (Iran, Islamic Republic of)

    2011-02-15

    The observed features in the temporal response patterns of a temperature-modulated chemoresistive gas sensor were used for gas diagnosis. The patterns were recorded for clean air and air contaminated with different levels of some volatile organic compounds while a staircase heating voltage waveform had been applied to the microheater of a tin oxide gas sensor that modulated its operating temperature. Combining the steady-state and transient parameters of the recorded responses in the 50-400 deg. C range resulted in discriminatory feature vectors which were utilized for contaminant classification. The information content of these feature vectors was proved sufficient for discrimination of methanol, ethanol, 1-butanol, and acetone contaminations in a wide concentration range.

  20. Utilizing the response patterns of a temperature modulated chemoresistive gas sensor for gas diagnosis

    International Nuclear Information System (INIS)

    Amini, Amir; Ghafarinia, Vahid

    2011-01-01

    The observed features in the temporal response patterns of a temperature-modulated chemoresistive gas sensor were used for gas diagnosis. The patterns were recorded for clean air and air contaminated with different levels of some volatile organic compounds while a staircase heating voltage waveform had been applied to the microheater of a tin oxide gas sensor that modulated its operating temperature. Combining the steady-state and transient parameters of the recorded responses in the 50-400 deg. C range resulted in discriminatory feature vectors which were utilized for contaminant classification. The information content of these feature vectors was proved sufficient for discrimination of methanol, ethanol, 1-butanol, and acetone contaminations in a wide concentration range.

  1. The Influence of Mixing in High Temperature Gas Phase Reactions

    DEFF Research Database (Denmark)

    Østberg, Martin

    1996-01-01

    by injection of NH3 with carrier gas into the flue gas. NH3 can react with NO and form N2, but a competing reaction path is the oxidation of NH3 to NO.The SNR process is briefly described and it is shown by chemical kinetic modelling that OH radicals under the present conditions will initiate the reaction......The objective of this thesis is to describe the mixing in high temperature gas phase reactions.The Selective Non-Catalytic Reduction of NOx (referred as the SNR process) using NH3 as reductant was chosen as reaction system. This in-furnace denitrification process is made at around 1200 - 1300 K...... diffusion. The SNR process is simulated using the mixing model and an empirical kinetic model based on laboratory experiments.A bench scale reactor set-up has been built using a natural gas burner to provide the main reaction gas. The set-up has been used to perform an experimental investigation...

  2. Study of the MWPC gas gain behaviour as a function of the gas pressure and temperature

    CERN Document Server

    Pinci, D

    2005-01-01

    The Muon System of the LHCb experiment is composed of five detection stations (M1-M5) equipped with 1368 Multi-Wire Proportional Chambers (MWPC) and 24 Triple-GEM detectors. The Multi Wire Proportional Chamber (MWPC) performances (detection efficiency, time resolution, pad-cluster size and ageing properties) are heavily dependent on the gas gain. The chamber gain depends on the gas density and therefore on the gas temperature and pressure. The impact of the environmental parameters on the MWPC gain has been studied in detail. The results, togheter with a simple method proposed to account for the gain variations, are reported in this note. The absolute gas gain at the testing voltage of 2750 V was also measured to be (1.2 +- 0.1)*10^5.

  3. Po2 temperature blood factor for blood gas apparatus.

    Science.gov (United States)

    Teisseire, B P; Hérigault, R A; Teisseire, L J; Laurent, D N

    1984-01-01

    PO2 temperature formulae supplied by manufacturers on automatic blood gas apparatus, PO2 corr. = PO2 37 degrees C X 10F X delta T were studied and compared to the experimental determination of the delta log PO2/delta T ratio (Hérigault et al. [10]). Acid-base status at 37 degrees C appeared to have a measurable influence on the PO2 temperature factor; alkalosis increased the delta log PO2/delta T ratio, and the contrary was found for acidosis in comparison with normal acid-base status at 37 degrees C. For the same PO2, measured at 37 degrees C, all the proposed formulae of commercial blood gas automatic apparatus did not give the same temperature corrected PO2. The observed difference between the corrected PO2 may be important and greater than the precision of the initial measurement. To correct the measured PO2 for temperature, a relationship between delta log PO2/delta T and PO2 is proposed, between PO2 zero and PO2 180 mmHg, which takes into account measured pH and PO2 values at 37 degrees C:delta log PO2/delta T = [(-0.35 pH + 0.658) X 10(-4) X PO2] + 0.035.

  4. Development of high temperature gas cooled reactor in China

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Wentao [Paul Scherrer Institute, Villigen (Switzerland). Dept. of Nuclear Energy and Safety; Schorer, Michael [Swiss Nuclear Forum, Olten (Switzerland)

    2018-02-15

    High temperature gas cooled reactor (HTGR) is one of the six Generation IV reactor types put forward by Generation IV International Forum (GIF) in 2002. This type of reactor has high outlet temperature. It uses Helium as coolant and graphite as moderator. Pebble fuel and ceramic reactor core are adopted. Inherit safety, good economy, high generating efficiency are the advantages of HTGR. According to the comprehensive evaluation from the international nuclear community, HTGR has already been given the priority to the research and development for commercial use. A demonstration project of the High Temperature Reactor-Pebble-�bed Modules (HTR-PM) in Shidao Bay nuclear power plant in China is under construction. In this paper, the development history of HTGR in China and the current situation of HTR-PM will be introduced. The experiences from China may be taken as a reference by the international nuclear community.

  5. Accelerated solvent extraction method with one-step clean-up for hydrocarbons in soil

    International Nuclear Information System (INIS)

    Nurul Huda Mamat Ghani; Norashikin Sain; Rozita Osman; Zuraidah Abdullah Munir

    2007-01-01

    The application of accelerated solvent extraction (ASE) using hexane combined with neutral silica gel and sulfuric acid/ silica gel (SA/ SG) to remove impurities prior to analysis by gas chromatograph with flame ionization detector (GC-FID) was studied. The efficiency of extraction was evaluated based on the three hydrocarbons; dodecane, tetradecane and pentadecane spiked to soil sample. The effect of ASE operating conditions (extraction temperature, extraction pressure, static time) was evaluated and the optimized condition obtained from the study was extraction temperature of 160 degree Celsius, extraction pressure of 2000 psi with 5 minutes static extraction time. The developed ASE with one-step clean-up method was applied in the extraction of hydrocarbons from spiked soil and the amount extracted was comparable to ASE extraction without clean-up step with the advantage of obtaining cleaner extract with reduced interferences. Therefore in the developed method, extraction and clean-up for hydrocarbons in soil can be achieved rapidly and efficiently with reduced solvent usage. (author)

  6. High-temperature gas effects on aerodynamic characteristics of waverider

    Directory of Open Access Journals (Sweden)

    Jun Liu

    2015-02-01

    Full Text Available This paper focuses on the analysis of high-temperature effect on a conical waverider and it is a typical configuration of near space vehicles. Two different gas models are used in the numerical simulations, namely the thermochemical non-equilibrium and perfect gas models. The non-equilibrium flow simulations are conducted with the usage of the parallel non-equilibrium program developed by the authors while the perfect gas flow simulations are carried out with the commercial software Fluent. The non-equilibrium code is validated with experimental results and grid sensitivity analysis is performed as well. Then, numerical simulations of the flow around the conical waverider with the two gas models are conducted. In the results, differences in the flow structures as well as aerodynamic performances of the conical waverider are compared. It is found that the thermochemical non-equilibrium effect is significant mainly near the windward boundary layer at the tail of the waverider, and the non-equilibrium influence makes the pressure center move forward to about 0.57% of the whole craft’s length at the altitude of 60 km.

  7. High temperature friction and seizure in gas cooled nuclear reactors

    International Nuclear Information System (INIS)

    Cousseran, P.; Febvre, A.; Martin, R.; Roche, R.

    1978-01-01

    One of the most delicate problems encountered in the gas cooled nuclear reactors is the friction without lubrication in a dry and hot (800 0 C /1472 0 F) helium atmosphere even at very small velocity. The research and development programs are described together with special tribometers that operate at mode than 1000 0 C (1832 0 F) in dry helium. The most interesting test conditions and results are given for gas nitrited steels and for strongly alloyed Ni-Cr steels coated with chromium carbide by plasma sprayed. The effects of parameters live velocity, travelled distance, contact pressure, roughness, temperature and prolonged stops under charge are described together with the effects of negative phenomena like attachment and chattering [fr

  8. Startup analysis for a high temperature gas loaded heat pipe

    Science.gov (United States)

    Sockol, P. M.

    1973-01-01

    A model for the rapid startup of a high-temperature gas-loaded heat pipe is presented. A two-dimensional diffusion analysis is used to determine the rate of energy transport by the vapor between the hot and cold zones of the pipe. The vapor transport rate is then incorporated in a simple thermal model of the startup of a radiation-cooled heat pipe. Numerical results for an argon-lithium system show that radial diffusion to the cold wall can produce large vapor flow rates during a rapid startup. The results also show that startup is not initiated until the vapor pressure p sub v in the hot zone reaches a precise value proportional to the initial gas pressure p sub i. Through proper choice of p sub i, startup can be delayed until p sub v is large enough to support a heat-transfer rate sufficient to overcome a thermal load on the heat pipe.

  9. Modular high-temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Shepherd, L.R.

    1988-01-01

    The high financial risk involved in building large nuclear power reactors has been a major factor in halting investment in new plant and in bringing further technical development to a standstill. Increased public concern about the safety of nuclear plant, particularly after Chernobyl, has contributed to this stagnation. Financial and technical risk could be reduced considerably by going to small modular units, which would make it possible to build up power station capacity in small steps. Such modular plant, based on the helium-cooled high temperature reactor (HTR), offers remarkable advantages in terms of inherent safety characteristics, partly because of the relatively small size of the individual modules but more on account of the enormous thermal capacity and high temperature margins of the graphitic reactor assemblies. Assessments indicate that, in the USA, the cost of power from the modular systems would be less than that from conventional single reactor plant, up to about 600 MW(e), and only marginally greater above that level, a margin that should be offset by the shorter time required in bringing the modular units on line to earn revenue. The modular HTR would be particularly appropriate in the UK, because of the considerable British industrial background in gas-cooled reactors, and could be a suitable replacement for Magnox. The modular reactor would be particularly suited to combined heat and power schemes and would offer great potential for the eventual development of gas turbine power conversion and the production of high-temperature process heat. (author)

  10. High-temperature gas-cooled reactors and process heat

    International Nuclear Information System (INIS)

    Kasten, P.R.

    1980-01-01

    High-Temperature Gas-Cooled Reactors (HTGRs) are fueled with ceramic-coated microspheres of uranium and thorium oxides/carbides embedded in graphite blocks which are cooled with helium. Promising areas of HTGR application are in cogeneration, energy transport using Heat Transfer Salt, recovery of oils from oil shale, steam reforming of methane for chemical production, coal gasification, and in energy transfer using chemical heat jpipes in the long term. Further, HTGRs could be used as the energy source for hydrogen production through thermochemical water splitting in the long term. The potential market for Process Heat HTGRs is 100-200 large units by about the year 2020

  11. Analysis of artificial fireplace logs by high temperature gas chromatography.

    Science.gov (United States)

    Kuk, Raymond J

    2002-11-01

    High temperature gas chromatography is used to analyze the wax of artificial fireplace logs (firelogs). Firelogs from several different manufacturers are studied and compared. This study shows that the wax within a single firelog is homogeneous and that the wax is also uniform throughout a multi-firelog package. Different brands are shown to have different wax compositions. Firelogs of the same brand, but purchased in different locations, also have different wax compositions. With this information it may be possible to associate an unknown firelog sample to a known sample, but a definitive statement of the origin cannot be made.

  12. Determination of phthalate diesters and monoesters in human milk and infant formula by fat extraction, size-exclusion chromatography clean-up and gas chromatography-mass spectrometry detection.

    Science.gov (United States)

    Del Bubba, Massimo; Ancillotti, Claudia; Checchini, Leonardo; Fibbi, Donatella; Rossini, Daniele; Ciofi, Lorenzo; Rivoira, Luca; Profeti, Claudio; Orlandini, Serena; Furlanetto, Sandra

    2018-01-30

    A sensitive and reliable analytical method was developed for the simultaneous determination of five phthalate diesters and corresponding monoesters in human milk samples and infant formulas. The method involved a liquid-liquid extraction with a CH 2 Cl 2 /CH 3 OH/NaCl 30% 2/1/0.5 (v/v/v) mixture, the clean-up of the extract by size-exclusion chromatography (swelling and elution solvent: cyclohexane/ethyl acetate 9/1v/v), the derivatization of monoesters by trimethylsilyl-diazomethane and instrumental analysis by gas chromatography coupled with mass spectrometry. Recovery was in the range of 83-115% and precision was found between 9% and 21%. For phthalate diesters, method detection limits (MDLs) ranged from hundreds of ng/kg to 4.2μg/kg on a fresh weight milk (f.w.) basis, depending on blank contribution evaluated in matrix. Lower MDLs (0.03-0.8μg/kg f.w.) were achieved for corresponding monoesters. The proposed method was applied to the determination of target compounds in nine human milk samples and four infant formulas, confirming their presence in all samples. However, a generally higher contamination was assessed in artificial milk than in breast milk samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. A study of silver behavior in Gas-turbine High Temperature Gas-cooled Reactor

    International Nuclear Information System (INIS)

    Sawa, Kazuhiro; Tanaka, Toshiyuki

    1995-11-01

    A Gas-turbine High Temperature Gas-cooled Reactor (GT-HTGR) is one of the promising reactor systems of future HTGRs. In the design of GT-HTGR, behavior of fission products, especially of silver, is considered to be important from the view point of maintenance of gas-turbine. A study of silver behavior in the GT-HTGR was carried out based on current knowledge. The purposes of this study were to determine an importance of the silver problem quantitatively, countermeasures to the problem and items of future research and development which will be needed. In this study, inventory, fractional release from fuel, plateout in the primary circuit and radiation dose were evaluated, respectively. Based on this study, it is predicted that gamma-ray from plateout silver in gas-turbine system contributes about a half of total radiation dose after reactor shutdown. In future, more detail data for silver release from fuel, plateout behavior, etc. using the High Temperature Engineering Test Reactor (HTTR), for example, will be needed to carry out reasonable design. (author)

  14. Safety philosophy of gas turbine high temperature reactor (GTHTR300)

    International Nuclear Information System (INIS)

    Shoji Katanishi; Kazuhiko Kunitomi; Shusaku Shiozawa

    2002-01-01

    Japan Atomic Energy Research Institute (JAERI) has undertaken the study of an original design concept of gas turbine high temperature reactor, the GTHTR300. The general concept of this study is development of a greatly simplified design that leads to substantially reduced technical and cost requirements. Newly proposed design features enable the GTHTR300 to be an efficient and economically competitive reactor in 2010's. Also, the GTHTR300 fully takes advantage of its inherent safety characteristics. The safety philosophy of the GTHTR300 is developed based on the HTTR (High Temperature Engineering Test Reactor) of JAERI which is the first HTGR in Japan. Major features of the newly proposed safety philosophy for the GTHTR300 are described in this article. (authors)

  15. The Approach to Cleanup at West Cumbria's Nuclear Sites

    International Nuclear Information System (INIS)

    Price, T.

    2006-01-01

    The cleanup of West Cumbria's nuclear sites is one of the most important and demanding managerial, technical and environmental challenges facing the UK over the next century. Considerable progress has already been made in cleaning up the Sellafield, Calder Hall, and Low-level Waste Repository (LLWR) sites but there remains significant challenge ahead. There are more than 200 nuclear facilities at the sites including redundant fuel storage ponds, redundant chemical plants and silos of solid waste and sludge. These legacy buildings exist alongside commercially operating reprocessing and fuel fabrication facilities. They are all linked together by a complex network of services including gas supplies, water supplies, waste disposal routes, and chemical supply routes. Many of the buildings requiring cleanup are very old and date back to the early years of the British nuclear industry. They were not designed with decommissioning in mind, and some require substantial improvement to provide a safe foundation from which to retrieve waste and decommission. The cleanup of these legacy facilities must be carefully balanced with the ongoing operations that provide services to commercial customers. Cleanup must be carried out safely and efficiently, without impacting upon commercial operations whose revenue is vital to funding the Cleanup organizations scope of work. This paper will introduce the cleanup approach at West Cumbria's Sellafield nuclear site. It will provide an overview of what is being done in preparation to meet the formidable but rewarding challenge ahead. (authors)

  16. Reduced one-body density matrix of Tonks–Girardeau gas at finite temperature

    International Nuclear Information System (INIS)

    Fu Xiao-Chen; Hao Ya-Jiang

    2015-01-01

    With thermal Bose–Fermi mapping method, we investigate the Tonks–Girardeau gas at finite temperature. It is shown that at low temperature, the Tonks gas displays the Fermi-like density profiles, and with the increase in temperature, the Tonks gas distributes in wider region. The reduced one-body density matrix is diagonal dominant in the whole temperature region, and the off-diagonal elements shall vanish rapidly with the deviation from the diagonal part at high temperature. (paper)

  17. U Plant Geographic Zone Cleanup Prototype

    International Nuclear Information System (INIS)

    Romine, L.D.; Leary, K.D.; Lackey, M.B.; Robertson, J.R.

    2006-01-01

    The U Plant geographic zone (UPZ) occupies 0.83 square kilometers on the Hanford Site Central Plateau (200 Area). It encompasses the U Plant canyon (221-U Facility), ancillary facilities that supported the canyon, soil waste sites, and underground pipelines. The UPZ cleanup initiative coordinates the cleanup of the major facilities, ancillary facilities, waste sites, and contaminated pipelines (collectively identified as 'cleanup items') within the geographic zone. The UPZ was selected as a geographic cleanup zone prototype for resolving regulatory, technical, and stakeholder issues and demonstrating cleanup methods for several reasons: most of the area is inactive, sufficient characterization information is available to support decisions, cleanup of the high-risk waste sites will help protect the groundwater, and the zone contains a representative cross-section of the types of cleanup actions that will be required in other geographic zones. The UPZ cleanup demonstrates the first of 22 integrated zone cleanup actions on the Hanford Site Central Plateau to address threats to groundwater, the environment, and human health. The UPZ contains more than 100 individual cleanup items. Cleanup actions in the zone will be undertaken using multiple regulatory processes and decision documents. Cleanup actions will include building demolition, waste site and pipeline excavation, and the construction of multiple, large engineered barriers. In some cases, different cleanup actions may be taken at item locations that are immediately adjacent to each other. The cleanup planning and field activities for each cleanup item must be undertaken in a coordinated and cohesive manner to ensure effective execution of the UPZ cleanup initiative. The UPZ zone cleanup implementation plan (ZCIP) [1] was developed to address the need for a fundamental integration tool for UPZ cleanup. As UPZ cleanup planning and implementation moves forward, the ZCIP is intended to be a living document that will

  18. The real gas behaviour of helium as a cooling medium for high-temperature reactors

    International Nuclear Information System (INIS)

    Hewing, G.

    1977-01-01

    The article describes the influence of the real gas behaviour on the variables of state for the helium gas and the effects on the design of high-temperature reactor plants. After explaining the basic equations for describing variables and changes of state of the real gas, the real and ideal gas behaviour is analysed. Finally, the influence of the real gas behaviour on the design of high-temperature reactors in one- and two-cycle plants is investigated. (orig.) [de

  19. Temperature profile and producer gas composition of high temperature air gasification of oil palm fronds

    International Nuclear Information System (INIS)

    Guangul, F M; Sulaiman, S A; Ramli, A

    2013-01-01

    Environmental pollution and scarcity of reliable energy source are the current pressing global problems which need a sustainable solution. Conversion of biomass to a producer gas through gasification process is one option to alleviate the aforementioned problems. In the current research the temperature profile and composition of the producer gas obtained from the gasification of oil palm fronds by using high temperature air were investigated and compared with unheated air. By preheating the gasifying air at 500°C the process temperature were improved and as a result the concentration of combustible gases and performance of the process were improved. The volumetric percentage of CO, CH4 and H2 were improved from 22.49, 1.98, and 9.67% to 24.98, to 2.48% and 13.58%, respectively. In addition, HHV, carbon conversion efficiency and cold gas efficiency were improver from 4.88 MJ/Nm3, 83.8% and 56.1% to 5.90 MJ/Nm3, 87.3% and 62.4%, respectively.

  20. Metaphysics methods development for high temperature gas cooled reactor analysis

    International Nuclear Information System (INIS)

    Seker, V.; Downar, T. J.

    2007-01-01

    Gas cooled reactors have been characterized as one of the most promising nuclear reactor concepts in the Generation-IV technology road map. Considerable research has been performed on the design and safety analysis of these reactors. However, the calculational tools being used to perform these analyses are not state-of-the-art and are not capable of performing detailed three-dimensional analyses. This paper presents the results of an effort to develop an improved thermal-hydraulic solver for the pebble bed type high temperature gas cooled reactors. The solution method is based on the porous medium approach and the momentum equation including the modified Ergun's resistance model for pebble bed is solved in three-dimensional geometry. The heat transfer in the pebble bed is modeled considering the local thermal non-equilibrium between the solid and gas, which results in two separate energy equations for each medium. The effective thermal conductivity of the pebble-bed can be calculated both from Zehner-Schluender and Robold correlations. Both the fluid flow and the heat transfer are modeled in three dimensional cylindrical coordinates and can be solved in steady-state and time dependent. The spatial discretization is performed using the finite volume method and the theta-method is used in the temporal discretization. A preliminary verification was performed by comparing the results with the experiments conducted at the SANA test facility. This facility is located at the Institute for Safety Research and Reactor Technology (ISR), Julich, Germany. Various experimental cases are modeled and good agreement in the gas and solid temperatures is observed. An on-going effort is to model the control rod ejection scenarios as described in the OECD/NEA/NSC PBMR-400 benchmark problem. In order to perform these analyses PARCS reactor simulator code will be coupled with the new thermal-hydraulic solver. Furthermore, some of the other anticipated accident scenarios in the benchmark

  1. Detection of gas-permeable fuel particles for highl 7490 temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Thiele, B.A.; Stinton, D.P.; Costanzo, D.A.

    1980-01-01

    Fuel for High-Temperature Gas-Cooled Reactors (HTGR) consists of uranium oxide-carbide and thoria microspheres coated with layers of pyrolytic carbon and silicon carbide. The pyrolytic carbon coatings must be gas-tight to perform properly during irradiation. Therefore, particles must be carefully characterized to determine the number of defective particles (ie bare kernels, and cracked or permeable coatings). Although techniques are available to determine the number of bare kernels or cracked coatings, no reliable technique has been available to measure coating permeability. This work describes a technique recently developed to determine whether coatings for a batch of particles are gas-tight or permeable. Although most of this study was performed on Biso-coated particles, the technique applies equally well to Triso-coated particles. About 150 randomly selected Biso-particle batches were studied in this work. These batches were first subjected to an 18-hr chlorination at 15000C, and the volatile thorium tetrachloride released through cracked or very permeable coatings was measured versus chlorination time. Chlorinated batches were also radiographed to detect any thorium that had migrated from the kernel into the coatings. From this work a technique was developed to determine coating permeability. This consists of an 18-hr chlorination of multiple samples without measurement of the heavy metal released. Each batch is then radiographed and the heavy metal diffusion within each particle is examined so it can be determined if a particle batch is permeable, slightly permeable, or gas-tight. (author)

  2. New deployment of high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Sekimoto, Hiroshi; Tsuchie, Yasuo; Kunitomi, Kazuhiko; Shiozawa, Shusaku; Konuki, Kaoru; Inagaki, Yoshiyuki; Hayakawa, Hitoshi

    2002-01-01

    The high temperature gas-cooled reactor (HTGR) is now under a condition difficult to know it well, because of considering not only power generation, but also diverse applications of its nuclear heat, of having extremely different safe principle from that of conventional reactors, of having two types of pebble-bed and block which are extremely different types, of promoting its construction plan in South Africa, of including its application to disposition of Russian surplus weapons plutonium of less reporting HTTR in Japan in spite of its full operation, and so on. However, HTGR is expected for an extremely important nuclear reactor aiming at the next coming one of LWR. HTGR which is late started and developed under complete private leading, is strongly conscious at environmental problem since its beginning. Before 30 years when large scale HTGR was expected to operate, it advertised a merit to reduce wasted heat because of its high temperature. As ratio occupied by electricity expands among application of energies, ratio occupied by the other energies are larger. When considering applications except electric power, high temperature thermal energy from HTGR can be thought wider applications than that from LWR and so on. (G.K.)

  3. Utilization of multi-purpose high temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Kawada, Osamu; Onuki, Yoshiaki; Wasaoka, Takeshi.

    1974-01-01

    Concerning the utilization of multi-purpose high temperature gas-cooled reactors, the electric power generation with gas turbines is described: features of HTR-He gas turbine power plants; the state of development of He gas turbines; and combined cycle with gas turbines and steam turbines. The features of gas turbines concern heat dissipation into the environment and the mode of load operation. Outstanding work in the development of He gas turbines is that in Hochtemperatur Helium-Turbine Project in West Germany. The power generation with combined gas turbines and steam turbines appears to be superior to that with gas turbines alone. (Mori, K.)

  4. Warm Cleanup of Coal-Derived Syngas: Multicontaminant Removal Process Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Spies, Kurt A.; Rainbolt, James E.; Li, Xiaohong S.; Braunberger, Beau; Li, Liyu; King, David L.; Dagle, Robert A.

    2017-02-15

    Warm cleanup of coal- or biomass-derived syngas requires sorbent and catalytic beds to protect downstream processes and catalysts from fouling. Sulfur is particularly harmful because even parts-per-million amounts are sufficient to poison downstream synthesis catalysts. Zinc oxide (ZnO) is a conventional sorbent for sulfur removal; however, its operational performance using real gasifier-derived syngas and in an integrated warm cleanup process is not well reported. In this paper, we report the optimal temperature for bulk desulfurization to be 450oC, while removal of sulfur to parts-per-billion levels requires a lower temperature of approximately 350oC. Under these conditions, we found that sulfur in the form of both hydrogen sulfide and carbonyl sulfide could be absorbed equally well using ZnO. For long-term operation, sorbent regeneration is desirable to minimize process costs. Over the course of five sulfidation and regeneration cycles, a ZnO bed lost about a third of its initial sulfur capacity, however sorbent capacity stabilized. Here, we also demonstrate, at the bench-scale, a process and materials used for warm cleanup of coal-derived syngas using five operations: 1) Na2CO3 for HCl removal, 2) regenerable ZnO beds for bulk sulfur removal, 3) a second ZnO bed for trace sulfur removal, 4) a Ni-Cu/C sorbent for multi-contaminant inorganic removal, and 5) a Ir-Ni/MgAl2O4 catalyst employed for ammonia decomposition and tar and light hydrocarbon steam reforming. Syngas cleanup was demonstrated through successful long-term performance of a poison-sensitive, Cu-based, water-gas-shift catalyst placed downstream of the cleanup process train. The tar reformer is an important and necessary operation with this particular gasification system; its inclusion was the difference between deactivating the water-gas catalyst with carbon deposition and successful 100-hour testing using 1 LPM of coal-derived syngas.

  5. Assessment and status report High-Temperature Gas-Cooled Reactor gas-turbine technology

    International Nuclear Information System (INIS)

    1981-01-01

    Purpose of this report is to present a brief summary assessment of the High Temperature Gas-Cooled Reactor - Gas Turbine (HTGR-GT) technology. The focal point for the study was a potential 2000 MW(t)/800 MW(e) HTGR-GT commercial plant. Principal findings of the study were that: the HTGR-GT is feasible, but with significantly greater development risk than the HTGR-SC (Steam Cycle). At the level of performance corresponding to the reference design, no incremental economic incentive can be identified for the HTGR-GT to offset the increased development costs and risk relative to the HTGR-SC. The relative economics of the HTGR-GT and HTGR-SC are not significantly impacted by dry cooling considerations. While reduced cycel complexity may ultimately result in a reliability advantage for the HTGR-GT, the value of that potential advantage was not quantified

  6. Comparative study of different clean-up techniques for the determination of λ-cyhalothrin and cypermethrin in palm oil matrices by gas chromatography with electron capture detection.

    Science.gov (United States)

    Muhamad, Halimah; Zainudin, Badrul Hisyam; Abu Bakar, Nor Kartini

    2012-10-15

    Solid phase extraction (SPE) and dispersive solid-phase extraction (d-SPE) were compared and evaluated for the determination of λ-cyhalothrin and cypermethrin in palm oil matrices by gas chromatography with an electron capture detector (GC-ECD). Several SPE sorbents such as graphitised carbon black (GCB), primary secondary amine (PSA), C(18), silica, and florisil were tested in order to minimise fat residues. The results show that mixed sorbents using GCB and PSA obtained cleaner extracts than a single GCB and PSA sorbents. The average recoveries obtained for each pesticide ranged between 81% and 114% at five fortification levels with the relative standard deviation of less than 7% in all cases. The limits of detection for these pesticides were ranged between 0.025 and 0.05 μg/g. The proposed method was applied successfully for the residue determination of both λ-cyhalothrin and cypermethrin in crude palm oil samples obtained from local mills throughout Malaysia. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Medium-size high-temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Peinado, C.O.; Koutz, S.L.

    1980-08-01

    This report summarizes high-temperature gas-cooled reactor (HTGR) experience for the 40-MW(e) Peach Bottom Nuclear Generating Station of Philadelphia Electric Company and the 330-MW(e) Fort St. Vrain Nuclear Generating Station of the Public Service Company of Colorado. Both reactors are graphite moderated and helium cooled, operating at approx. 760 0 C (1400 0 F) and using the uranium/thorium fuel cycle. The plants have demonstrated the inherent safety characteristics, the low activation of components, and the high efficiency associated with the HTGR concept. This experience has been translated into the conceptual design of a medium-sized 1170-MW(t) HTGR for generation of 450 MW of electric power. The concept incorporates inherent HTGR safety characteristics [a multiply redundant prestressed concrete reactor vessel (PCRV), a graphite core, and an inert single-phase coolant] and engineered safety features

  8. Advances in High Temperature Gas Cooled Reactor Fuel Technology

    International Nuclear Information System (INIS)

    2012-12-01

    This publication reports on the results of a coordinated research project on advances in high temperature gas cooled reactor (HTGR) fuel technology and describes the findings of research activities on coated particle developments. These comprise two specific benchmark exercises with the application of HTGR fuel performance and fission product release codes, which helped compare the quality and validity of the computer models against experimental data. The project participants also examined techniques for fuel characterization and advanced quality assessment/quality control. The key exercise included a round-robin experimental study on the measurements of fuel kernel and particle coating properties of recent Korean, South African and US coated particle productions applying the respective qualification measures of each participating Member State. The summary report documents the results and conclusions achieved by the project and underlines the added value to contemporary knowledge on HTGR fuel.

  9. Advances in High Temperature Gas Cooled Reactor Fuel Technology

    International Nuclear Information System (INIS)

    2012-06-01

    This publication reports on the results of a coordinated research project on advances in high temperature gas cooled reactor (HTGR) fuel technology and describes the findings of research activities on coated particle developments. These comprise two specific benchmark exercises with the application of HTGR fuel performance and fission product release codes, which helped compare the quality and validity of the computer models against experimental data. The project participants also examined techniques for fuel characterization and advanced quality assessment/quality control. The key exercise included a round-robin experimental study on the measurements of fuel kernel and particle coating properties of recent Korean, South African and US coated particle productions applying the respective qualification measures of each participating Member State. The summary report documents the results and conclusions achieved by the project and underlines the added value to contemporary knowledge on HTGR fuel.

  10. Safety analysis of a high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Shimazu, Akira; Morimoto, Toshio

    1975-01-01

    In recent years, in order to satisfy the social requirements of environment and safety and also to cope with the current energy stringency, the installation of safe nuclear power plants is indispensable. Herein, safety analysis and evaluation to confirm quantitatively the safety design of a nuclear power plant become more and more important. The safety analysis and its methods for a high temperature gas-cooled reactor are described, with emphasis placed on the practices by Fuji Electric Manufacturing Co. Fundamental rule of securing plant safety ; safety analysis in normal operation regarding plant dynamic characteristics and radioactivity evaluation ; and safety analysis at the time of accidents regarding plant response to the accidents and radioactivity evaluation are explained. (Mori, K.)

  11. Control of temperature distribution in a supercritical gas extraction tower

    International Nuclear Information System (INIS)

    Yoshida, M.; Matsumoto, S.; Honda, G.; Iwama, T.; Suzuki, Y.; Odagiri, S.

    1989-01-01

    A control scheme recently proposed by the authors is applied to the control of axial temperature distribution in a bench-scale supercritical-gas extractor. The extraction unit is constructed from a packed column 3 m long covered by a coaxial cylindrical casing. Although the actual structure of the extractor is very complicated, it is modeled by a simple double-pipe and therefore its mathematical model can be described by a pair of partial differential equations. The models are reduced to a lumped parameter system with a finite dimension by use of the finite Fourier transform technique. The controller is designed on the basis of the reduced model. An extended Kalman filter is used to estimate simultaneously the state variables and the unknown parameters. The results demonstrate that both the state estimation and the controller performance are satisfactory. This implies that the control scheme is very robust in spite of the incompleteness of the model used

  12. Accelerated cleanup risk reduction

    International Nuclear Information System (INIS)

    Knapp, R.B.; Aines, R.M.; Blake, R.G.; Copeland, A.B.; Newmark, R.L.; Tompson, A.F.B.

    1998-01-01

    well was 'capped'. Our results show the formation of an inclined gas phase during injection and a fast collapse of the steam zone within an hour of terminating steam injection. The majority of destruction occurs during the collapse phase, when contaminant laden water is drawn back towards the well. Little to no noncondensible gasses are created in this process, removing any possibility of sparging processes interfering with contaminant destruction. Our models suggest that the thermal region should be as hot and as large as possible. To have HPO accepted, we need to demonstrate the in situ destruction of contaminants. This requires the ability to inexpensively sample at depth and under high temperatures. We proved the ability to implies monitoring points at depths exceeding 150 feet in highly heterogeneous soils by use of cone penetrometry. In addition, an extractive system has been developed for sampling fluids and measuring their chemistry under the range of extreme conditions expected. We conducted a collaborative field test of HPO at a Superfund site in southern California where the contaminant is mainly creosote and pentachlorophenol. Field results confirm the destruction of contaminants by HPO, validate our field design from simulations, demonstrate that accurate field measurements of the critical fluid parameters can be obtained using existing monitoring wells (and minimal capital cost) and yield reliable cost estimates for future commercial application. We also

  13. Working gas temperature and pressure changes for microscale thermal creep-driven flow caused by discontinuous wall temperatures

    International Nuclear Information System (INIS)

    Han, Yen-Lin

    2010-01-01

    Microscale temperature gradient-driven (thermal creep/transpiration) gas flows have attracted significant interest during the past decade. For free molecular and transitional conditions, applying temperature gradients to a flow channel's walls induces the thermal creep effect. This results in a working gas flowing through the channel from cold to hot, which is generally accompanied by a rising pressure from cold to hot in the channel. Working gas temperature and pressure distributions can vary significantly, depending on a flow channel's configuration and wall temperature distribution. Understanding working gas temperature excursions, both increases and decreases, is essential to ensure the effective use of thermal creep flows in microscale applications. In this study, the characterizations of working gas temperature variations, due to both temperature discontinuities and more gradual changes, on a variety of flow channel walls, were systematically investigated using the direct simulation Monte Carlo (DSMC) method. A micro/meso-scale pump, the Knudsen compressor, was chosen to illustrate the importance of controlling working gas temperature in thermal creep-driven flows. Gas pressure and temperature variations, through several Knudsen compressor stage configurations, were studied to determine the most advantageous flow phenomena for the efficient operation of Knudsen compressors.

  14. Accelerating cleanup: Paths to closure

    International Nuclear Information System (INIS)

    1998-06-01

    This report describes the status of Environmental Management's (EM's) cleanup program and a direction forward to complete achievement of the 2006 vision. Achieving the 2006 vision results in significant benefits related to accomplishing EM program objectives. As DOE sites accelerate cleanup activities, risks to public health, the environment, and worker safety and health are all reduced. Finding more efficient ways to conduct work can result in making compliance with applicable environmental requirements easier to achieve. Finally, as cleanup activities at sites are completed, the EM program can focus attention and resources on the small number of sites with more complex cleanup challenges. Chapter 1 describes the process by which this report has been developed and what it hopes to accomplish, its relationship to the EM decision-making process, and a general background of the EM mission and program. Chapter 2 describes how the site-by-site projections were constructed, and summarizes, for each of DOE's 11 Operations/Field Offices, the projected costs and schedules for completing the cleanup mission. Chapter 3 presents summaries of the detailed cleanup projections from three of the 11 Operations/Field Offices: Rocky Flats (Colorado), Richland (Washington), and Savannah River (South Carolina). The remaining eight Operations/Field Office summaries are in Appendix E. Chapter 4 reviews the cost drivers, budgetary constraints, and performance enhancements underlying the detailed analysis of the 353 projects that comprise EM's accelerated cleanup and closure effort. Chapter 5 describes a management system to support the EM program. Chapter 6 provides responses to the general comments received on the February draft of this document

  15. Optimization of an online heart-cutting multidimensional gas chromatography clean-up step for isotopic ratio mass spectrometry and simultaneous quadrupole mass spectrometry measurements of endogenous anabolic steroid in urine.

    Science.gov (United States)

    Casilli, Alessandro; Piper, Thomas; de Oliveira, Fábio Azamor; Padilha, Monica Costa; Pereira, Henrique Marcelo; Thevis, Mario; de Aquino Neto, Francisco Radler

    2016-11-01

    Measuring carbon isotope ratios (CIRs) of urinary analytes represents a cornerstone of doping control analysis and has been particularly optimized for the detection of the misuse of endogenous steroids. Isotope ratio mass spectrometry (IRMS) of appropriate quality, however, necessitates adequate purities of the investigated steroids, which requires extensive pre-analytical sample clean-up steps due to both the natural presence of the target analytes and the high complexity of the matrix. In order to accelerate the sample preparation and increase the automation of the process, the use of multidimensional gas chromatography (MDGC) prior to IRMS experiments, was investigated. A well-established instrumental configuration based on two independent GC ovens and one heart-cutting device was optimized. The first dimension (1D) separation was obtained by a non-polar column which assured high efficiency and good loading capacity, while the second dimension (2D), based on a mid-polar stationary phase, provided good selectivity. A flame ionization detector monitored the 1D, and the 2D was simultaneously recorded by isotope ratio and quadrupole mass spectrometry. The assembled MDGC set-up was applied for measuring testosterone, 5α- and 5β-androstanediol, androsterone, and etiocholanolone as target compounds and pregnanediol as endogenous reference compound. The urine sample were pretreated by conventional sample preparation steps comprising solid-phase extraction, hydrolysis, and liquid-liquid extraction. The extract obtained was acetylated and different aliquots were injected into the MDGC system. Two high performance liquid chromatography steps, conventionally adopted prior to CIR measurements, were replaced by the MDGC approach. The obtained values were consistent with the conventional ones. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Primary secondary amine as a sorbent material in dispersive solid-phase extraction clean-up for the determination of indicator polychlorinated biphenyls in environmental water samples by gas chromatography with electron capture detection.

    Science.gov (United States)

    Guo, Yuanming; Hu, Hongmei; Li, Tiejun; Xue, Lijian; Zhang, Xiaoning; Zhong, Zhi; Zhang, Yurong; Jin, Yanjian

    2017-08-01

    A simple, rapid, and novel method has been developed and validated for determination of seven indicator polychlorinated biphenyls in water samples by gas chromatography with electron capture detection. 1 L of water samples containing 30 g of anhydrous sodium sulfate was first liquid-liquid extracted with an automated Jipad-6XB vertical oscillator using n-hexane/dichloromethane (1:1, v/v). The concentrated extract was cleaned up by dispersive solid-phase extraction with 100 mg of primary secondary amine as sorbent material. The linearity of this method ranged from 1.25 to 100 μg/L, with regression coefficients ranging between 0.9994 and 0.9999. The limits of detection were in the ng/L level, ranging between 0.2 and 0.3 ng/L. The recoveries of seven spiked polychlorinated biphenyls with external calibration method at different concentration levels in tap water, lake water, and sea water were in the ranges of 85-112, 76-116, and 72-108%, respectively, and with relative standard deviations of 3.3-4.5, 3.4-5.6, and 3.1-4.8% (n = 5), respectively. The performance of the proposed method was compared with traditional liquid-liquid extraction and solid-phase extraction clean-up methods, and comparable efficiencies were obtained. It is concluded that this method can be successfully applied for the determination of polychlorinated biphenyls in different water samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. DRUCKFLAMM - Investigation on combustion and hot gas cleanup in pulverized coal combustion systems. Final report; DRUCKFLAMM - Untersuchungen zur Verbrennung und Heissgasreinigung bei der Druckkohlenstaubfeuerung. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hein, K.R.G.; Benoehr, A.; Schuermann, H.; Stroehle, J.; Klaiber, C.; Kuhn, R.; Maier, J.; Schnell, U.; Unterberger, S.

    2001-07-01

    The ambitions of making energy supply more efficient and less polluting brought forth the development of coal based combined cycle power plants allowing considerable increases in net efficiencies. One of the regarded firing concepts for a coal based combined cycle power plant is represented by the pressurised pulverised coal combustion process which has the highest efficiency potential compared with the other coal based concepts. The fundamental purpose of the project was to gain firm knowledge concerning firing behaviour of coal in a pressurised pulverised coal combustion system. Detailed investigations were carried out in a pressurised entrained flow reactor taking into account fuel conversion and particle behaviour, pollutant formation and material behaviour under conditions of a pressurised pulverised coal firing. During the project's investigations several different measurement techniques were tested and partially also acquired (e.g. a two-colour-pyrometry system to measure simultaneous particle surface temperature and particle diameter of burning fuel particles). Calculation models under pressurised conditions for pressure vessel simulation and better scale-up were developed synchronously with the experimental investigations. The results gained using the pressurised entrained flow reactor show that many combustion mechanisms are influenced by increased pressure, for instance the fuel conversion is intensified and at the same time pollutant emissions decreased. The material investigations show that the ceramic materials used due to the very high combustion temperatures are very sensitive versus slagging and fast temperature changes, therefore further development requirements are needed to fully realise the high durability of ceramics in the pressurised furnace. Concerning the improvement of existing models for furnace simulation under pressurised conditions, a good resemblance can be observed when considering the actual measurement results from the test

  18. Contribution to high-temperature chromatography and high-temperature-gas-chromatography-mass spectrometry of lipids

    International Nuclear Information System (INIS)

    Aichholz, R.

    1998-04-01

    This thesis describes the use of high temperature gas chromatography for the investigation of unusual triacylglycerols, cyanolipids and bees waxes. The used glass capillary columns were pretreated and coated with tailor made synthesized high temperature stable polysiloxane phases. The selective separation properties of the individual columns were tested with a synthetic lipid mixture. Suitable derivatization procedures for the gaschromatographic analyses of neutral lipids, containing multiple bonds as well as hydroxy-, epoxy-, and carboxyl groups, were developed and optimized. Therefore conjugated olefinic-, conjugated olefinic-acetylenic-, hydroxy-, epoxy-, and conjugated olefinic keto triacylglycerols in miscellaneous plant seed oils as well as hydroxy monoesters, diesters and hydroxy diesters in bees waxes could be analysed directly with high temperature gas chromatography for the first time. In order to elucidate the structures of separated lipid compounds, high temperature gas chromatography was coupled to mass spectrometry and tandem mass spectrometry, respectively. Comparable analytical systems are hitherto not commercial available. Therefore instrumental prerequisites for a comprehensive and detailed analysis of seed oils and bees waxes were established. In GC/MS commonly two ionization methods are used, electron impact ionization and chemical ionization. For the analysis of lipids the first is of limited use only. Due to intensive fragmentation only weak molecular ions are observed. In contrast, the chemical ionization yields in better results. Dominant quasi molecular ions enable an unambiguous determination of the molecular weight. Moreover, characteristic fragment ions provide important indications of certain structural features of the examined compounds. Nevertheless, in some cases the chromatographic resolution was insufficient in order to separate all compounds present in natural lipid mixtures. Owing to the selected detection with mass spectrometry

  19. Very-high-temperature gas reactor environmental impacts assessment

    International Nuclear Information System (INIS)

    Baumann, C.D.; Barton, C.J.; Compere, E.L.; Row, T.H.

    1977-08-01

    The operation of a Very High Temperature Reactor (VHTR), a slightly modified General Atomic type High Temperature Gas-Cooled Reactor (HTGR) with 1600 F primary coolant, as a source of process heat for the 1400 0 F steam-methanation reformer step in a hydrogen producing plant (via hydrogasification of coal liquids) was examined. It was found that: (a) from the viewpoint of product contamination by fission and activation products, an Intermediate Heat Exchanger (IHX) is probably not necessary; and (b) long term steam corrosion of the core support posts may require increasing their diameter (a relatively minor design adjustment). However, the hydrogen contaminant in the primary coolant which permeates the reformer may reduce steam corrosion but may produce other problems which have not as yet been resolved. An IHX in parallel with both the reformer and steam generator would solve these problems, but probably at greater cost than that of increasing the size of the core support posts. It is recommended that this corrosion problem be examined in more detail, especially by investigating the performance of current fossil fuel heated reformers in industry. Detailed safety analysis of the VHTR would be required to establish definitely whether the IHX can be eliminated. Water and hydrogen ingress into the reactor system are potential problems which can be alleviated by an IHX. These problems will require analysis, research and development within the program required for development of the VHTR

  20. Recent developments in high temperature coatings for gas turbine airfoils

    Science.gov (United States)

    Goward, G. W.

    1983-01-01

    The importance of coatings for hot section airfoils has increased with the drive for more cost-effective use of fuel in a wide variety of gas turbine engines. Minor additions of silicon have been found to appreciably increase the oxidation resistance of plasma-sprayed NiCoCrAlY coatings on a single crystal nickel-base superalloy. Increasing the chromium content of MCrAlY coatings substantially increases the resistance to acidic (Na2SO4-SO3) hot corrosion at temperatures of about 1300 F (704 C) but gives no significant improvement beyond contemporary coatings in the range of 1600 F (871 C). Surface enrichment of MCrAlY coatings with silicon also gives large increases in resistance to acidic hot corrosion in the 1300 F region. The resistance to the thermal stress-induced spalling of zirconia-based thermal barrier coatings has been improved by lowering coating stresses with segmented structures and by controlling the substrate temperature during coating fabrication.

  1. Parametric studies on different gas turbine cycles for a high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Wang Jie; Gu Yihua

    2005-01-01

    The high temperature gas-cooled reactor (HTGR) coupled with turbine cycle is considered as one of the leading candidates for future nuclear power plants. In this paper, the various types of HTGR gas turbine cycles are concluded as three typical cycles of direct cycle, closed indirect cycle and open indirect cycle. Furthermore they are theoretically converted to three Brayton cycles of helium, nitrogen and air. Those three types of Brayton cycles are thermodynamically analyzed and optimized. The results show that the variety of gas affects the cycle pressure ratio more significantly than other cycle parameters, however, the optimized cycle efficiencies of the three Brayton cycles are almost the same. In addition, the turbomachines which are required for the three optimized Brayton cycles are aerodynamically analyzed and compared and their fundamental characteristics are obtained. Helium turbocompressor has lower stage pressure ratio and more stage number than those for nitrogen and air machines, while helium and nitrogen turbocompressors have shorter blade length than that for air machine

  2. Liquid-Liquid Extraction/Low-Temperature Purification (LLE/LTP Followed by Dispersive Solid-Phase Extraction (d-SPE Cleanup for Multiresidue Analysis in Palm Oil by LC-QTOF-MS

    Directory of Open Access Journals (Sweden)

    Elham Sobhanzadeh

    2013-01-01

    Full Text Available An evaluation of the extraction of multiresidue pesticides from palm oil by liquid-liquid extraction/low-temperature purification (LLE/LTP coupled with dispersive solid-phase extraction (d-SPE as the cleanup procedure with the determination by liquid chromatography mass spectrometry using electrospray as the ionization source (LC-ESI-MS was carried out. Optimization approaches were studied in terms of d-SPE to select efficiency of type and mass of adsorbents to obtain the highest recovery yield of pesticides and the lowest coextract fat residues in the final extract. The optimal conditions of d-SPE were obtained using 3 g of palm oil, 4 g anhydrous MgSO4, 150 mg of PSA, and 50 mg of GCB (PSA: GCB (3 : 1 w/w. Recovery study was performed at three concentration levels (25, 50, and 100 ng kg−1, yielding recovery rates between 71.8 and 112.4% except diuron with relative standard deviations of 3.2–15.1%. Detection and quantification limits were lower than 2.7 and 8.2 ng kg−1, respectively. The proposed method was successfully applied to the analysis of market-purchased palm oil samples from two different brands collected in Kuala Lumpur, showing its potential applicability and revealing the presence of some of the target species in the ng g−1 range.

  3. Innovative technologies for soil cleanup

    International Nuclear Information System (INIS)

    Yow, J.L. Jr.

    1992-09-01

    These notes provide a broad overview of current developments in innovative technologies for soil cleanup. In this context, soil cleanup technologies include site remediation methods that deal primarily with the vadose zone and with relatively shallow, near-surface contamination of soil or rock materials. This discussion attempts to emphasize approaches that may be able to achieve significant improvements in soil cleanup cost or effectiveness. However, since data for quantitative performance and cost comparisons of new cleanup methods are scarce, preliminary comparisons must be based on the scientific approach used by each method and on the sits-specific technical challenges presented by each sold contamination situation. A large number of technical alternatives that are now in research, development, and testing can be categorized by the scientific phenomena that they employ and by the site contamination situations that they treat. After cataloging a representative selection of these technologies, one of the new technologies, Dynamic Underground Stripping, is discussed in more detail to highlight a promising soil cleanup technology that is now being field tested

  4. Innovative technologies for groundwater cleanup

    International Nuclear Information System (INIS)

    Yow, J.L. Jr.

    1992-09-01

    These notes provide a broad overview of current developments in innovative technologies for groundwater cleanup. In this context, groundwater cleanup technologies include site remediation methods that deal with contaminants in ground water or that may move from the vadose zone into ground water. This discussion attempts to emphasize approaches that may be able to achieve significant improvements in groundwater cleanup cost or effectiveness. However, since data for quantitative performance and cost comparisons of new cleanup methods are scarce, preliminary comparisons must be based on the scientific approach used by each method and on the site-specific technical challenges presented by each groundwater contamination situation. A large number of technical alternatives that are now in research, development, and testing can be categorized by the scientific phenomena that they employ and by the site contamination situations that they treat. After reviewing a representative selection of these technologies, one of the new technologies, the Microbial Filter method, is discussed in more detail to highlight a promising in situ groundwater cleanup technology that is now being readied for field testing

  5. Fernald incident underscores DOE cleanup woes

    International Nuclear Information System (INIS)

    Lobsenz, G.

    1994-01-01

    Miscalculations and poor safety planning led to a large release of deadly gas during an error-plagued effort to plug a leaking uranium hexafluoride canister discovered lying in a scrap heap at the Energy Department's Fernald plant last year, according to a DOE investigative report. Investigators with DOE's Office of Environment, Safety and Health said serious injury was avoided only because the wind happened to blow the toxic cloud of hydrogen fluoride gas away from inadequately protected Fernald workers watching the July 1993 canister-plugging operation at the Ohio plant. The investigators said the 25-minute canister repair effort - captured on videotape - was marked by poor planning by the Fernald Environmental Restoration Management Corp. (FERMCO), a Fluor Daniel subsidiary hired by DOE for its cleanup expertise

  6. Corrosion behaviour of high temperature alloys in the cooling gas of high temperature reactors

    International Nuclear Information System (INIS)

    Quadakkers, W.J.; Schuster, H.

    1989-01-01

    The reactive impurities in the primary cooling helium of advanced high temperature gas cooled reactors (HTGR) can cause oxidation, carburization or decarburization of the heat exchanging metallic components. By studies of the fundamental aspects of the corrosion mechanisms it became possible to define operating conditions under which the metallic construction materials show, from the viewpoint of technical application, acceptable corrosion behaviour. By extensive test programmes with exposure times of up to 30,000 hours, a data base has been obtained which allows a reliable extrapolation of the corrosion effects up to the envisaged service lives of the heat exchanging components. (author). 6 refs, 7 figs

  7. Temperature Control of Gas Chromatograph Based on Switched Delayed System Techniques

    Directory of Open Access Journals (Sweden)

    Xiao-Liang Wang

    2014-01-01

    Full Text Available We address the temperature control problem of the gas chromatograph. We model the temperature control system of the gas chromatograph into a switched delayed system and analyze the stability by common Lyapunov functional technique. The PI controller parameters can be given based on the proposed linear matrix inequalities (LMIs condition and the designed controller can make the temperature of gas chromatograph track the reference signal asymptotically. An experiment is given to illustrate the effectiveness of the stability criterion.

  8. Oil spills and their cleanup

    International Nuclear Information System (INIS)

    Fingas, M.

    1995-01-01

    Oil spills are an unfortunately common occurrence in the world's seas and can have extensive damaging environmental consequences. This article examines various methods of cleaning up oil spills, evaluates their effectiveness in various situations, and identifies areas where, current methods being inadequate, further research is needed. Containment, mechanical removal, shoreline cleanup, chemical treating agents, in situ burning, natural recovery and enhanced bioremediation are all assessed. The cleanup method must be selected to match environmental conditions. Results are good in quiet, sheltered waters, but need extensive development in open waters and high seas. (UK)

  9. Structural instabilities of high temperature alloys and their use in advanced high temperature gas cooled reactors

    International Nuclear Information System (INIS)

    Schuster, H.; Ennis, P.J.; Nickel, H.; Czyrska-Filemonowicz, A.

    1989-01-01

    High-temperature, iron-nickel and nickel based alloys are the candidate heat exchanger materials for advanced high temperature gas-cooled reactors supplying process heat for coal gasification, where operation temperatures can reach 850-950 deg. C and service lives of more than 100,000 h are necessary. In the present paper, typical examples of structural changes which occur in two representative alloys (Alloy 800 H, Fe-32Ni-20Cr and Alloy 617, Ni-22Cr-12Co-9Mo-1Al) during high temperature exposure will be given and the effects on the creep rupture properties discussed. At service temperatures, precipitation of carbides occurs which has a significant effect on the creep behaviour, especially in the early stages of creep when the precipitate particles are very fine. During coarsening of the carbides, carbides at grain boundaries restrict grain boundary sliding which retards the development of creep damage. In the service environments, enhanced carbide precipitation may occur due to the ingress of carbon from the environment (carburization). Although the creep rate is not adversely affected, the ductility of the carburized material at low and intermediate temperatures is very low. During simulated service exposures, the formation of surface corrosion scales, the precipitation of carbides and the formation of internal oxides below the surface leads to depletion of the matrix in the alloying elements involved in the corrosion processes. In thin-walled tubes the depletion of Cr due to Cr 2 O 3 formation on the surface can lead to a loss of creep strength. An additional depletion effect resulting from environmental-metal reactions is the loss of carbon (decarburization) which may occur in specific environments. The compositions of the cooling gases which decarburize the material have been determined; they are to be avoided during reactor operation

  10. Use of thorium for high temperature gas-cooled reactors

    Energy Technology Data Exchange (ETDEWEB)

    Guimarães, Cláudio Q., E-mail: claudio_guimaraes@usp.br [Universidade de São Paulo (USP), SP (Brazil). Instituto de Física; Stefani, Giovanni L. de, E-mail: giovanni.stefani@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Santos, Thiago A. dos, E-mail: thiago.santos@ufabc.edu.br [Universidade Federal do ABC (UFABC), Santo André, SP (Brazil)

    2017-07-01

    The HTGR ( High Temperature Gas-cooled Reactor) is a 4{sup th} generation nuclear reactor and is fuelled by a mixture of graphite and fuel-bearing microspheres. There are two competitive designs of this reactor type: The German “pebble bed” mode, which is a system that uses spherical fuel elements, containing a graphite-and-fuel mixture coated in a graphite shell; and the American version, whose fuel is loaded into precisely located graphite hexagonal prisms that interlock to create the core of the vessel. In both variants, the coolant consists of helium pressurised. The HTGR system operates most efficiently with the thorium fuel cycle, however, so relatively little development has been carried out in this country on that cycle for HTGRs. In the Nuclear Engineering Centre of IPEN (Instituto de Pesquisas Energéticas e Nucleares), a study group is being formed linked to thorium reactors, whose proposal is to investigate reactors using thorium for {sup 233}U production and rejects burning. The present work intends to show the use of thorium in HTGRs, their advantages and disadvantages and its feasibility. (author)

  11. Inherently safe high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Yamada, Masao; Hayakawa, Hitoshi

    1987-01-01

    It is recognized in general that High Temperature Gas-cooled Reactors have remarkable characteristics in inherent safety and it is well known that credits of the time margin have been admitted for accident evaluation in the licensing of the currently operating prototype HTGRs (300 MWe class). Recently, more inherently safe HTGRs are being developed in various countries and drawing attention on their possibility for urban siting. The inherent safety characteristics of these HTRs differ each other depending on their design philosophy and on the features of the components/structures which constitute the plant. At first, the specific features/characteristics of the elemental components/structures of the HTRs are explained one by one and then the overall safety features/characteristics of these HTR plants are explained in connection with their design philosophy and combination of the elemental features. Taking the KWU/Interatom Modular Reactor System as an example, the particular design philosophy and safety characteristics of the inherently safe HTR are explained with a result of preliminary evaluation on the possibility of siting close to densely populated area. (author)

  12. Recycling Facilities - Land Recycling Cleanup Locations

    Data.gov (United States)

    NSGIC Education | GIS Inventory — Land Recycling Cleanup Location Land Recycling Cleanup Locations (LRCL) are divided into one or more sub-facilities categorized as media: Air, Contained Release or...

  13. Infrared temperature and gas measurements at the Haderslev power and heat plan[Denmark]; Infraroede temperatur- og gasmaelinger Haderslev Kraftvarmevaerk

    Energy Technology Data Exchange (ETDEWEB)

    Clausen, Soennik

    2007-04-15

    Report describe results from a two week measurement campaign at Haderslev Kraftvarmevaerk in 2006 as a part of PSO-project 5727 'On-line optimization of waste incinerators'. Non-contact gas temperature and gas composition was measured simultaneously with a FTIR spectrometer coupled to a water-cooled fiber-optic probe. Gas temperature and H{sub 2}O, CO{sub 2}, CO, C{sub x}H{sub y} and HCl concentrations was extracted from measured spectra of emitted thermal radiation from gas slab over a 25 cm path. Measurements where performed in different positions to obtain a overview of flow behavior and conditions during stable operation and during a step in operation conditions, e.g. changing combustion air flows. Furthermore, surface temperature of grate was monitored with a thermal camera and a cross stack reference measurement on hot outlet gas was performed with a FTIR spectrometer. (au)

  14. High Temperature Gas-to-Gas Heat Exchanger Based on a Solid Intermediate Medium

    Directory of Open Access Journals (Sweden)

    R. Amirante

    2014-04-01

    Full Text Available This paper proposes the design of an innovative high temperature gas-to-gas heat exchanger based on solid particles as intermediate medium, with application in medium and large scale externally fired combined power plants fed by alternative and dirty fuels, such as biomass and coal. An optimization procedure, performed by means of a genetic algorithm combined with computational fluid dynamics (CFD analysis, is employed for the design of the heat exchanger: the goal is the minimization of its size for an assigned heat exchanger efficiency. Two cases, corresponding to efficiencies equal to 80% and 90%, are considered. The scientific and technical difficulties for the realization of the heat exchanger are also faced up; in particular, this work focuses on the development both of a pressurization device, which is needed to move the solid particles within the heat exchanger, and of a pneumatic conveyor, which is required to deliver back the particles from the bottom to the top of the plant in order to realize a continuous operation mode. An analytical approach and a thorough experimental campaign are proposed to analyze the proposed systems and to evaluate the associated energy losses.

  15. Study on Method of Ultrasonic Gas Temperature Measure Based on FPGA

    Energy Technology Data Exchange (ETDEWEB)

    Wen, S H; Xu, F R [Institute of Electrical Engineering, Yanshan University, Qinhuangdao, 066004 (China)

    2006-10-15

    It is always a problem to measure instantaneous temperature of high-temperature and high-pressure gas. There is difficulty for the conventional method of measuring temperature to measure quickly and exactly, and the measuring precision is low, the ability of anti-jamming is bad, etc. So the article introduces a method of measuring burning gas temperature using ultrasonic based on Field-Programmable Gate Array (FPGA). The mathematic model of measuring temperature is built with the relation of velocity of ultrasonic transmitting and gas Kelvin in the ideal gas. The temperature can be figured out by measuring the difference of ultrasonic frequency {delta}f. FPGA is introduced and a high-precision data acquisition system based on digital phase-shift technology is designed. The feasibility of proposed above is confirmed more by measuring pressure of burning gas timely. Experimental result demonstrates that the error is less than 12.. and the precision is heightened to 0.8%.

  16. On the second-order temperature jump coefficient of a dilute gas

    Science.gov (United States)

    Radtke, Gregg A.; Hadjiconstantinou, N. G.; Takata, S.; Aoki, K.

    2012-09-01

    We use LVDSMC simulations to calculate the second-order temperature jump coefficient for a dilute gas whose temperature is governed by the Poisson equation with a constant forcing term. Both the hard sphere gas and the BGK model of the Boltzmann equation are considered. Our results show that the temperature jump coefficient is different from the well known linear and steady case where the temperature is governed by the homogeneous heat conduction (Laplace) equation.

  17. Development of teleoperated cleanup system

    International Nuclear Information System (INIS)

    Kim, Ki Ho; Park, J. J.; Yang, M. S.; Kwon, H. J.

    2005-01-01

    This report describes the development of a teleoperated cleanup system for use in a highly radioactive environment of DFDF(DUPIC Fuel Demonstration Facility) at KAERI where direct human access to the in-cell is strictly limited. The teleoperated cleanup system was designed to remotely remove contaminants placed or fixed on the floor surface of the hot-cell by mopping them with wet cloth. This cleanup system consists of a mopping slave, a mopping master and a control console. The mopping slave located at the in-cell comprises a mopping tool with a mopping cloth and a mobile platform, which were constructed in modules to facilitate maintenance. The mopping master that is an input device to control the mopping slave has kinematic dissimilarity with the mopping slave. The control console provides a means of bilateral control flows and communications between the mopping master and the mopping slave. In operation, the human operator from the out-of-cell performs a series of decontamination tasks remotely by manipulating the mopping slave located in-cell via a mopping master, having a sense of real mopping. The environmental and mechanical design considerations, and control systems of the developed teleoperated cleanup system are also described

  18. CFD Analysis of the Fuel Temperature in High Temperature Gas-Cooled Reactors

    International Nuclear Information System (INIS)

    In, W. K.; Chun, T. H.; Lee, W. J.; Chang, J. H.

    2005-01-01

    High temperature gas-cooled reactors (HTGR) have received a renewed interest as potential sources for future energy needs, particularly for a hydrogen production. Among the HTGRs, the pebble bed reactor (PBR) and a prismatic modular reactor (PMR) are considered as the nuclear heat source in Korea's nuclear hydrogen development and demonstration project. PBR uses coated fuel particles embedded in spherical graphite fuel pebbles. The fuel pebbles flow down through the core during an operation. PMR uses graphite fuel blocks which contain cylindrical fuel compacts consisting of the fuel particles. The fuel blocks also contain coolant passages and locations for absorber and control material. The maximum fuel temperature in the core hot spot is one of the important design parameters for both PBR and PMR. The objective of this study is to predict the fuel temperature distributions in PBR and PMR using a computational fluid dynamics(CFD) code, CFX-5. The reference reactor designs used in this analysis are PBMR400 and GT-MHR600

  19. Electron temperature and density measurement of tungsten inert gas arcs with Ar-He shielding gas mixture

    Science.gov (United States)

    Kühn-Kauffeldt, M.; Marques, J.-L.; Forster, G.; Schein, J.

    2013-10-01

    The diagnostics of atmospheric welding plasma is a well-established technology. In most cases the measurements are limited to processes using pure shielding gas. However in many applications shielding gas is a mixture of various components including metal vapor in gas metal arc welding (GMAW). Shielding gas mixtures are intentionally used for tungsten inert gas (TIG) welding in order to improve the welding performance. For example adding Helium to Argon shielding gas allows the weld geometry and porosity to be influenced. Yet thermal plasmas produced with gas mixtures or metal vapor still require further experimental investigation. In this work coherent Thomson scattering is used to measure electron temperature and density in these plasmas, since this technique allows independent measurements of electron and ion temperature. Here thermal plasmas generated by a TIG process with 50% Argon and 50% Helium shielding gas mixture have been investigated. Electron temperature and density measured by coherent Thomson scattering have been compared to the results of spectroscopic measurements of the plasma density using Stark broadening of the 696.5 nm Argon spectral line. Further investigations of MIG processes using Thomson scattering technique are planned.

  20. Electron temperature and density measurement of tungsten inert gas arcs with Ar-He shielding gas mixture

    International Nuclear Information System (INIS)

    Kühn-Kauffeldt, M; Marques, J-L; Forster, G; Schein, J

    2013-01-01

    The diagnostics of atmospheric welding plasma is a well-established technology. In most cases the measurements are limited to processes using pure shielding gas. However in many applications shielding gas is a mixture of various components including metal vapor in gas metal arc welding (GMAW). Shielding gas mixtures are intentionally used for tungsten inert gas (TIG) welding in order to improve the welding performance. For example adding Helium to Argon shielding gas allows the weld geometry and porosity to be influenced. Yet thermal plasmas produced with gas mixtures or metal vapor still require further experimental investigation. In this work coherent Thomson scattering is used to measure electron temperature and density in these plasmas, since this technique allows independent measurements of electron and ion temperature. Here thermal plasmas generated by a TIG process with 50% Argon and 50% Helium shielding gas mixture have been investigated. Electron temperature and density measured by coherent Thomson scattering have been compared to the results of spectroscopic measurements of the plasma density using Stark broadening of the 696.5 nm Argon spectral line. Further investigations of MIG processes using Thomson scattering technique are planned

  1. Influence of Gas-Liquid Interface on Temperature Wave of Pulsating Heat Pipe

    Directory of Open Access Journals (Sweden)

    Ying Zhang

    2018-01-01

    Full Text Available The influence of the interface on the amplitude and phase of the temperature wave and the relationship between the attenuation of the temperature wave and the gas-liquid two-phase physical parameters are studied during the operation of the pulsating heat pipe. The numerical simulation shows that the existence of the phase interface changes the direction of the temperature gradient during the propagation of the temperature wave, which increases the additional “thermal resistance.” The relative size of the gas-liquid two-phase thermal conductivity affects the propagation direction of heat flow at phase interface directly. The blockage of the gas plug causes hysteresis in the phase of the temperature wave, the relative size of the gas-liquid two-phase temperature coefficient will gradually increase the phase of the temperature wave, and the time when the heat flow reaches the peak value is also advanced. The attenuation of the temperature wave is almost irrelevant to the absolute value of the density, heat capacity, and thermal conductivity of the gas-liquid two phases, and the ratio of the thermal conductivity of the gas-liquid two phases is related. When the temperature of the heat pipe was changed, the difference of heat storage ability between gas and liquid will lead to the phenomenon of heat reflux and becomes more pronounced with the increases of the temperature wave.

  2. Shoreline clean-up methods : biological treatments

    Energy Technology Data Exchange (ETDEWEB)

    Massoura, S.T. [Oil Spill Response Limited, Southampton (United Kingdom)

    2009-07-01

    The cleanup of oil spills in shoreline environments is a challenging issue worldwide. Oil spills receive public and media attention, particularly in the event of a coastal impact. It is important to evaluate the efficiency and effectiveness of cleanup methods when defining the level of effort and consequences that are appropriate to remove or treat different types of oil on different shoreline substrates. Of the many studies that have compared different mechanical, chemical and biological treatments for their effectiveness on various types of oil, biological techniques have received the most attention. For that reason, this paper evaluated the effectiveness and effects of shoreline cleanup methods using biological techniques. It summarized data from field experiments and oil spill incidents, including the Exxon Valdez, Sea Empress, Prestige, Grand Eagle, Nakhodka, Guanabara Bay and various Gulf war oil spills. Five major shoreline types were examined, notably rocky intertidal, cobble/pebble/gravel, sand/mud, saltmarsh, and mangrove/sea-grass. The biological techniques that were addressed were nutrient enrichment, hydrocarbon-utilizing bacteria, vegetable oil biosolvents, plants, surf washing, oil-particle interactions and natural attenuation. The study considered the oil type, volume and fate of stranded oil, location of coastal materials, extent of pollution and the impact of biological techniques. The main factors that affect biodegradation of hydrocarbons are the volume, chemical composition and weathering state of the petroleum product as well as the temperature, oxygen availability of nutrients, water salinity, pH level, water content, and microorganisms in the shoreline environment. The interaction of these factors also affect the biodegradation of oil. It was concluded that understanding the fate of stranded oil can help in the development of techniques that improve the weathering and degradation of oil on complex shoreline substrates. 39 refs.

  3. Determination of ten steroid hormones in animal waste manure and agricultural soil using inverse and integrated clean-up pressurized liquid extraction and gas chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Hansen, Martin; Krogh, Kristine Andersen; Halling-Sørensen, Bent

    2011-01-01

    ... Martin Hansen , Kristine A. Krogh , Bent Halling ... in a 22 mL PLE cell : firstly by flushing the sample with heptane to remove unwanted matrix components (inverse- PLE , i- PLE ) and secondly, performing internal clean-up (ic- PLE ) and eluting the steroid hormones by attaching an ...

  4. Coated particle fuel for high temperature gas cooled reactors

    Energy Technology Data Exchange (ETDEWEB)

    Verfondern, Karl; Nabielek, Heinz [Research Center Julich (FZJ), Julich (Germany); Kendall, James M. [Global Virtual L1c, Prescott (United States)

    2007-10-15

    applications at 850-900 .deg. C and for process heat/hydrogen generation applications with 950 .deg. C outlet temperatures. There is a clear set of standards for modern high quality fuel in terms of low levels of heavy metal contamination, manufacture-induced particle defects during fuel body and fuel element making, irradiation/accident induced particle failures and limits on fission product release from intact particles. While gas-cooled reactor design is still open-ended with blocks for the prismatic and spherical fuel elements for the pebble-bed design, there is near worldwide agreement on high quality fuel: a 500 {mu}m diameter UO{sub 2} kernel of 10% enrichment is surrounded by a 100 {mu}m thick sacrificial buffer layer to be followed by a dense inner pyrocarbon layer, a high quality silicon carbide layer of 35 {mu}m thickness and theoretical density and another outer pyrocarbon layer. Good performance has been demonstrated both under operational and under accident conditions, i.e. to 10% FIMA and maximum 1600 .deg. C afterwards. And it is the wide-ranging demonstration experience that makes this particle superior. Recommendations are made for further work: 1. Generation of data for presently manufactured materials, e.g. SiC strength and strength distribution, PyC creep and shrinkage and many more material data sets. 2. Renewed start of irradiation and accident testing of modern coated particle fuel. 3. Analysis of existing and newly created data with a view to demonstrate satisfactory performance at burnups beyond 10% FIMA and complete fission product retention even in accidents that go beyond 1600 .deg. C for a short period of time. This work should proceed at both national and international level.

  5. Coated particle fuel for high temperature gas cooled reactors

    International Nuclear Information System (INIS)

    Verfondern, Karl; Nabielek, Heinz; Kendall, James M.

    2007-01-01

    and for process heat/hydrogen generation applications with 950 .deg. C outlet temperatures. There is a clear set of standards for modern high quality fuel in terms of low levels of heavy metal contamination, manufacture-induced particle defects during fuel body and fuel element making, irradiation/accident induced particle failures and limits on fission product release from intact particles. While gas-cooled reactor design is still open-ended with blocks for the prismatic and spherical fuel elements for the pebble-bed design, there is near worldwide agreement on high quality fuel: a 500 μm diameter UO 2 kernel of 10% enrichment is surrounded by a 100 μm thick sacrificial buffer layer to be followed by a dense inner pyrocarbon layer, a high quality silicon carbide layer of 35 μm thickness and theoretical density and another outer pyrocarbon layer. Good performance has been demonstrated both under operational and under accident conditions, i.e. to 10% FIMA and maximum 1600 .deg. C afterwards. And it is the wide-ranging demonstration experience that makes this particle superior. Recommendations are made for further work: 1. Generation of data for presently manufactured materials, e.g. SiC strength and strength distribution, PyC creep and shrinkage and many more material data sets. 2. Renewed start of irradiation and accident testing of modern coated particle fuel. 3. Analysis of existing and newly created data with a view to demonstrate satisfactory performance at burnups beyond 10% FIMA and complete fission product retention even in accidents that go beyond 1600 .deg. C for a short period of time. This work should proceed at both national and international level

  6. Experimental optimization of temperature distribution in the hot-gas duct through the installation of internals in the hot-gas plenum of a high-temperature reactor

    International Nuclear Information System (INIS)

    Henssen, J.; Mauersberger, R.

    1990-01-01

    The flow conditions in the hot-gas plenum and in the adjacent hot-gas ducts and hot-gas pipes for the high-temperature reactor project PNP-1000 (nuclear process heat project for 1000 MW thermal output) have been examined experimentally. The experiments were performed in a closed loop in which the flow model to be analyzed, representing a 60deg sector of the core bottom of the PNP-1000 with connecting hot-gas piping and diverting arrangements, was installed. The model scale was approx. 1:5.6. The temperature and flow velocity distribution in the hot-gas duct was registered by means of 14 dual hot-wire flowmeters. Through structural changes and/or the installation of internals into the hot-gas plenum of the core bottom offering little flow resistance coolant gas temperature differentials produced in the core could be reduced to such an extent that a degree of mixture amounting to over 80% was achieved at the entrance of the connected heat exchanger systems. Thereby the desired goal of an adequate degree of mixture of the hot gas involving an acceptable pressure loss was reached. (orig.)

  7. Proliferation resistance assessment of high temperature gas reactors

    Energy Technology Data Exchange (ETDEWEB)

    Chikamatsu N, M. A. [Instituto Tecnologico y de Estudios Superiores de Monterrey, Campus Santa Fe, Av. Carlos Lazo No. 100, Santa Fe, 01389 Mexico D. F. (Mexico); Puente E, F., E-mail: midori.chika@gmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-10-15

    The Generation IV International Forum has established different objectives for the new generation of reactors to accomplish. These objectives are focused on sustain ability, safety, economics and proliferation resistance. This paper is focused on how the proliferation resistance of the High Temperature Gas Reactors (HTGR) is assessed and the advantages that these reactors present currently. In this paper, the focus will be on explaining why such reactors, HTGR, can achieve the goals established by the GIF and can present a viable option in terms of proliferation resistance, which is an issue of great importance in the field of nuclear energy generation. The reason why the HTGR are being targeted in this writing is that these reactors are versatile, and present different options from modular reactors to reactors with the same size as the ones that are being operated today. Besides their versatility, the HTGR has designed features that might improve on the overall sustain ability of the nuclear reactors. This is because the type of safety features and materials that are used open up options for industrial processes to be carried out; cogeneration for instance. There is a small section that mentions how HTGR s are being developed in the international sector in order to present the current world view in this type of technology and the further developments that are being sought. For the proliferation resistance section, the focus is on both the intrinsic and the extrinsic features of the nuclear systems. The paper presents a comparison between the features of Light Water Reactors (LWR) and the HTGR in order to be able to properly compare the most used technology today and one that is gaining international interest. (Author)

  8. Proliferation resistance assessment of high temperature gas reactors

    International Nuclear Information System (INIS)

    Chikamatsu N, M. A.; Puente E, F.

    2014-10-01

    The Generation IV International Forum has established different objectives for the new generation of reactors to accomplish. These objectives are focused on sustain ability, safety, economics and proliferation resistance. This paper is focused on how the proliferation resistance of the High Temperature Gas Reactors (HTGR) is assessed and the advantages that these reactors present currently. In this paper, the focus will be on explaining why such reactors, HTGR, can achieve the goals established by the GIF and can present a viable option in terms of proliferation resistance, which is an issue of great importance in the field of nuclear energy generation. The reason why the HTGR are being targeted in this writing is that these reactors are versatile, and present different options from modular reactors to reactors with the same size as the ones that are being operated today. Besides their versatility, the HTGR has designed features that might improve on the overall sustain ability of the nuclear reactors. This is because the type of safety features and materials that are used open up options for industrial processes to be carried out; cogeneration for instance. There is a small section that mentions how HTGR s are being developed in the international sector in order to present the current world view in this type of technology and the further developments that are being sought. For the proliferation resistance section, the focus is on both the intrinsic and the extrinsic features of the nuclear systems. The paper presents a comparison between the features of Light Water Reactors (LWR) and the HTGR in order to be able to properly compare the most used technology today and one that is gaining international interest. (Author)

  9. The Integration Of Process Heat Applications To High Temperature Gas Reactors

    International Nuclear Information System (INIS)

    McKellar, Michael G.

    2011-01-01

    A high temperature gas reactor, HTGR, can produce industrial process steam, high-temperature heat-transfer gases, and/or electricity. In conventional industrial processes, these products are generated by the combustion of fossil fuels such as coal and natural gas, resulting in significant emissions of greenhouse gases such as carbon dioxide. Heat or electricity produced in an HTGR could be used to supply process heat or electricity to conventional processes without generating any greenhouse gases. Process heat from a reactor needs to be transported by a gas to the industrial process. Two such gases were considered in this study: helium and steam. For this analysis, it was assumed that steam was delivered at 17 MPa and 540 C and helium was delivered at 7 MPa and at a variety of temperatures. The temperature of the gas returning from the industrial process and going to the HTGR must be within certain temperature ranges to maintain the correct reactor inlet temperature for a particular reactor outlet temperature. The returning gas may be below the reactor inlet temperature, ROT, but not above. The optimal return temperature produces the maximum process heat gas flow rate. For steam, the delivered pressure sets an optimal reactor outlet temperature based on the condensation temperature of the steam. ROTs greater than 769.7 C produce no additional advantage for the production of steam.

  10. Determination of an instability temperature for alloys in the cooling gas of a high temperature reactor

    International Nuclear Information System (INIS)

    Grimmer, H.; Grman, D.; Krompholz, K.; Zimmermann, U.; Ullrich, G.

    1985-05-01

    High temperature alloys designed to be used for components in the primary circuit of a helium cooled high temperature nuclear reactor show massive CO production above a certain temperature, called the instability temperature T/sub i/, which increases with increasing partial pressure of CO in the cooling gas. At p/sub CO/ = 15 microbar, T/sub i/ lies between 900 and 950 degrees C for the four alloys under investigation: T/sub i/ is lowest for the iron base alloy Incoloy 800 H and increases for the nickel base alloys in the order Inconel 617, HDA 230 and Nimonic 86. Measurements of T/sub i/ made at 3 different laboratories were compared and shown to agree for p/sub CO/ 25 microbar, compatible with CO production by a reaction of Cr2O3 with carbides. Some measurements of T/sub i/ on HDA 230 and Nimonic 86 were performed in the course of simulated reactor disturbances. They showed that the oxide layer looses its protective properties above T/sub i/. A highlight of the examinations was the detection of eta-carbides (M6C) with unusual properties. M6C is the only type of carbide occuring in HDA 230. An eta-carbide with a lattice constant of 1088.8 pm had developed at the surface of Nimonic 86 during pre-oxidation before the disturbance simulation. Its composition is estimated at Ni3SiMo2C. Eta-carbides containing Si and especially eta-carbides with lattice constants as low as 1088.8 pm have been described only rarely until now. (author)

  11. A low-temperature (4-300K) constant volume gas thermometer

    International Nuclear Information System (INIS)

    Combarieu, A. de

    1976-01-01

    A constant volume gas thermometer was built to calibrate the various secondary thermometers used at low temperature. This gas thermometer is placed in a cryostat where any stable temperature between 4 and 300K may be obtained. The principle is outlined, then the gas thermometer and its auxiliary equipment are briefly described; the corrections to be applied to the results are given and a table shows the values obtained [fr

  12. Modeling of Aerobrake Ballute Stagnation Point Temperature and Heat Transfer to Inflation Gas

    Science.gov (United States)

    Bahrami, Parviz A.

    2012-01-01

    A trailing Ballute drag device concept for spacecraft aerocapture is considered. A thermal model for calculation of the Ballute membrane temperature and the inflation gas temperature is developed. An algorithm capturing the most salient features of the concept is implemented. In conjunction with the thermal model, trajectory calculations for two candidate missions, Titan Explorer and Neptune Orbiter missions, are used to estimate the stagnation point temperature and the inflation gas temperature. Radiation from both sides of the membrane at the stagnation point and conduction to the inflating gas is included. The results showed that the radiation from the membrane and to a much lesser extent conduction to the inflating gas, are likely to be the controlling heat transfer mechanisms and that the increase in gas temperature due to aerodynamic heating is of secondary importance.

  13. Gas Between the Stars: What Determines its Temperature?

    Indian Academy of Sciences (India)

    The interstellar gas in galaxies is heated by stellar radiationand cosmic rays and it also cools through radiation. We takea detailed look at these processes in order to understand thethermal state of equilibrium of the interstellar gas. This gasalso manifests itself in different 'phases'– molecular, neutralatomic and ionized, ...

  14. Coolant cleanup system for BWR type reactor

    International Nuclear Information System (INIS)

    Kinoshita, Shoichiro; Araki, Hidefumi.

    1993-01-01

    The cleanup system of the present invention removes impurity ions and floating materials accumulated in a reactor during evaporation of coolants in the nuclear reactor. That is, coolants pass pipelines from a pressure vessel using pressure difference between a high pressure in the pressure vessel and a low pressure at the upstream of a condensate filtration/desalting device of a condensate/feed water system as a driving source, during which cations and floating materials are removed in a high temperature filtration/desalting device and coolants flow into the condensate/feedwater system. Impurities containing anions are removed here by the condensates filtration/desalting device. Then, they return to the pressure vessel while pressurized and heated by a condensate pump, a feed water pump and a feed water heater. At least pumps, a heat exchanger for heating, a filtration/desalting device for removing anions and pipelines connecting them used exclusively for the coolant cleanup system are no more necessary. (I.S.)

  15. Silicon Carbide-Based Hydrogen Gas Sensors for High-Temperature Applications

    Directory of Open Access Journals (Sweden)

    Sangchoel Kim

    2013-10-01

    Full Text Available We investigated SiC-based hydrogen gas sensors with metal-insulator-semiconductor (MIS structure for high temperature process monitoring and leak detection applications in fields such as the automotive, chemical and petroleum industries. In this work, a thin tantalum oxide (Ta2O5 layer was exploited with the purpose of sensitivity improvement, because tantalum oxide has good stability at high temperature with high permeability for hydrogen gas. Silicon carbide (SiC was used as a substrate for high-temperature applications. We fabricated Pd/Ta2O5/SiC-based hydrogen gas sensors, and the dependence of their I-V characteristics and capacitance response properties on hydrogen concentrations were analyzed in the temperature range from room temperature to 500 °C. According to the results, our sensor shows promising performance for hydrogen gas detection at high temperatures.

  16. Temperature dependence of gas sensing behaviour of TiO2 doped PANI composite thin films

    Science.gov (United States)

    Srivastava, Subodh; Sharma, S. S.; Sharma, Preetam; Sharma, Vinay; Rajura, Rajveer Singh; Singh, M.; Vijay, Y. K.

    2014-04-01

    In the present work we have reported the effect of temperature on the gas sensing properties of TiO2 doped PANI composite thin film based chemiresistor type gas sensors for hydrogen gas sensing application. PANI and TiO2 doped PANI composite were synthesized by in situ chemical oxidative polymerization of aniline at low temperature. The electrical properties of these composite thin films were characterized by I-V measurements as function of temperature. The I-V measurement revealed that conductivity of composite thin films increased as the temperature increased. The changes in resistance of the composite thin film sensor were utilized for detection of hydrogen gas. It was observed that at room temperature TiO2 doped PANI composite sensor shows higher response value and showed unstable behavior as the temperature increased. The surface morphology of these composite thin films has also been characterized by scanning electron microscopy (SEM) measurement.

  17. Scaling Studies for High Temperature Test Facility and Modular High Temperature Gas-Cooled Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Richard R. Schult; Paul D. Bayless; Richard W. Johnson; James R. Wolf; Brian Woods

    2012-02-01

    The Oregon State University (OSU) High Temperature Test Facility (HTTF) is an integral experimental facility that will be constructed on the OSU campus in Corvallis, Oregon. The HTTF project was initiated, by the U.S. Nuclear Regulatory Commission (NRC), on September 5, 2008 as Task 4 of the 5-year High Temperature Gas Reactor Cooperative Agreement via NRC Contract 04-08-138. Until August, 2010, when a DOE contract was initiated to fund additional capabilities for the HTTF project, all of the funding support for the HTTF was provided by the NRC via their cooperative agreement. The U.S. Department of Energy (DOE) began their involvement with the HTTF project in late 2009 via the Next Generation Nuclear Plant (NGNP) project. Because the NRC's interests in HTTF experiments were only centered on the depressurized conduction cooldown (DCC) scenario, NGNP involvement focused on expanding the experimental envelope of the HTTF to include steady-state operations and also the pressurized conduction cooldown (PCC).

  18. Volume overload cleanup: An approach for on-line SPE-GC, GPC-GC, and GPC-SPE-GC

    NARCIS (Netherlands)

    Kerkdijk, H.; Mol, H.G.J.; Nagel, B. van der

    2007-01-01

    A new concept for cleanup, based on volume overloading of the cleanup column, has been developed for on-line coupling of gel permeation chromatography (GPC), solid-phase extraction (SPE), or both, to gas chromatography (GC). The principle is outlined and the applicability demonstrated by the

  19. High Temperature Gas Cooled Reactor Fuels and Materials

    International Nuclear Information System (INIS)

    2010-03-01

    At the third annual meeting of the technical working group on Nuclear Fuel Cycle Options and Spent Fuel Management (TWG-NFCO), held in Vienna, in 2004, it was suggested 'to develop manuals/handbooks and best practice documents for use in training and education in coated particle fuel technology' in the IAEA's Programme for the year 2006-2007. In the context of supporting interested Member States, the activity to develop a handbook for use in the 'education and training' of a new generation of scientists and engineers on coated particle fuel technology was undertaken. To make aware of the role of nuclear science education and training in all Member States to enhance their capacity to develop innovative technologies for sustainable nuclear energy is of paramount importance to the IAEA Significant efforts are underway in several Member States to develop high temperature gas cooled reactors (HTGR) based on either pebble bed or prismatic designs. All these reactors are primarily fuelled by TRISO (tri iso-structural) coated particles. The aim however is to build future nuclear fuel cycles in concert with the aim of the Generation IV International Forum and includes nuclear reactor applications for process heat, hydrogen production and electricity generation. Moreover, developmental work is ongoing and focuses on the burning of weapon-grade plutonium including civil plutonium and other transuranic elements using the 'deep-burn concept' or 'inert matrix fuels', especially in HTGR systems in the form of coated particle fuels. The document will serve as the primary resource materials for 'education and training' in the area of advanced fuels forming the building blocks for future development in the interested Member States. This document broadly covers several aspects of coated particle fuel technology, namely: manufacture of coated particles, compacts and elements; design-basis; quality assurance/quality control and characterization techniques; fuel irradiations; fuel

  20. Influence of the gas mixture radio on the correlations between the excimer XeCl emission and the sealed gas temperature in dielectric barrier discharge lamps

    CERN Document Server

    Xu Jin Zhou; Ren Zhao Xing

    2002-01-01

    For dielectric barrier discharge lamps filled with various gas mixture ratios, the correlations between the excimer XeCl emission and the sealed gas temperature have been founded, and a qualitative explication is presented. For gas mixture with chlorine larger than 3%, the emission intensity increases with the sealed gas temperature, while with chlorine about 2%, the emission intensity decreases with the increasing in the gas temperature, and could be improved by cooling water. However, if chlorine is less than 1.5%, the discharge appears to be a mixture mode with filaments distributed in a diffused glow-like discharge, and the UV emission is independent on the gas temperature

  1. Some problems on materials tests in high temperature hydrogen base gas mixture

    International Nuclear Information System (INIS)

    Shikama, Tatsuo; Tanabe, Tatsuhiko; Fujitsuka, Masakazu; Yoshida, Heitaro; Watanabe, Ryoji

    1980-01-01

    Some problems have been examined on materials tests (creep rupture tests and corrosion tests) in high temperature mixture gas of hydrogen (80%H 2 + 15%CO + 5%CO 2 ) simulating the reducing gas for direct steel making. H 2 , CO, CO 2 and CH 4 in the reducing gas interact with each other at elevated temperature and produce water vapor (H 2 O) and carbon (soot). Carbon deposited on the walls of retorts and the water condensed at pipings of the lower temperature gas outlet causes blocking of gas flow. The gas reactions have been found to be catalyzed by the retort walls, and appropriate selection of the materials for retorts has been found to mitigate the problems caused by water condensation and carbon deposition. Quartz has been recognized to be one of the most promising materials for minimizing the gas reactions. And ceramic coating, namely, BN (born nitride) on the heat resistant superalloy, MO-RE II, has reduced the amounts of water vapor and deposited carbon (sooting) produced by gas reactions and has kept dew points of outlet gas below room temperature. The well known emf (thermo-electromotive force) deterioration of Alumel-Chromel thermocouples in the reducing gases at elevated temperatures has been also found to be prevented by the ceramic (BN) coating. (author)

  2. Simulation of temperature-pressure profiles and wax deposition in gas-lift wells

    Directory of Open Access Journals (Sweden)

    Sevic Snezana

    2017-01-01

    Full Text Available Gas-lift is an artificial lift method in which gas is injected down the tubing- -casing annulus and enters the production tubing through the gas-lift valves to reduce the hydrostatic pressure of the formation fluid column. The gas changes pressure, temperature and fluid composition profiles throughout the production tubing string. Temperature and pressure drop along with the fluid composition changes throughout the tubing string can lead to wax, asphaltenes and inorganic salts deposition, increased emulsion stability and hydrate formation. This paper presents a new model that can sucesfully simulate temperature and pressure profiles and fluid composition changes in oil well that operates by means of gas-lift. This new model includes a pipe-in-pipe segment (production tubing inside production casing, countercurrent flow of gas-lift gas and producing fluid, heat exchange between gas-lift gas and the surrounding ambient – ground; and gas-lift gas with the fluid in the tubing. The model enables a better understanding of the multiphase fluid flow up the production tubing. Model was used to get insight into severity and locations of wax deposition. The obtained information on wax deposition can be used to plan the frequency and depth of wax removing operations. Model was developed using Aspen HYSYS software.

  3. Development of data logger for atmospheric pressure, temperature and relative humidity for gas-filled detector

    International Nuclear Information System (INIS)

    Sahu, S.; Sahu, P.K.; Bhuyan, M.R.; Biswas, S.; Mohanty, B.

    2014-01-01

    At IoP-NISER an initiative has been taken to build and test micro-pattern gas detector such as Gas Electron Multiplier (GEM) for several upcoming High-Energy Physics (HEP) experiment projects. Temperature (t), atmospheric pressure (p) and relative humidity (RH) monitor and recording is very important for gas filled detector development. A data logger to monitor and record the ambient parameters such as temperature, relative humidity and pressure has been developed. With this data logger continuous recording of t, p, RH and time stamp can be done with a programmable sampling interval. This data is necessary to correct the gain of a gas filled detector

  4. Transient fission gas release from UO2 fuel for high temperature and high burnup

    International Nuclear Information System (INIS)

    Szuta, M.

    2001-01-01

    In the present paper it is assumed that the fission gas release kinetics from an irradiated UO 2 fuel for high temperature is determined by the kinetics of grain growth. A well founded assumption that Vitanza curve describes the change of uranium dioxide re-crystallization temperature and the experimental results referring to the limiting grain size presented in the literature are used to modify the grain growth model. Algorithms of fission gas release due to re-crystallization of uranium dioxide grains are worked out. The defect trap model of fission gas behaviour described in the earlier papers is supplemented with the algorithms. Calculations of fission gas release in function of time, temperature, burn-up and initial grain sizes are obtained. Computation of transient fission gas release in the paper is limited to the case where steady state of irradiation to accumulate a desired burn-up is performed below the temperature of re-crystallization then the subsequent step temperature increase follows. There are considered two kinds of step temperature increase for different burn-up: the final temperature of the step increase is below and above the re-crystallization temperature. Calculations show that bursts of fission gas are predicted in both kinds. The release rate of gas liberated for the final temperature above the re-crystallization temperature is much higher than for final temperature below the re-crystallization temperature. The time required for the burst to subside is longer due to grain growth than due to diffusion of bubbles and knock-out release. The theoretical results explain qualitatively the experimental data but some of them need to be verified since this sort of experimental data are not found in the available literature. (author)

  5. High Temperature Gas-cooled Reactor Projected Markets and Scoping Economics

    Energy Technology Data Exchange (ETDEWEB)

    Larry Demick

    2010-08-01

    The NGNP Project has the objective of developing the high temperature gas-cooled reactor (HTGR) technology to supply high temperature process heat to industrial processes as a substitute for burning of fossil fuels, such as natural gas. Applications of the HTGR technology that have been evaluated by the NGNP Project for supply of process heat include supply of electricity, steam and high-temperature gas to a wide range of industrial processes, and production of hydrogen and oxygen for use in petrochemical, refining, coal to liquid fuels, chemical, and fertilizer plants.

  6. Investigation of ambient temperature on the performance of GE-F5 gas turbine

    International Nuclear Information System (INIS)

    Ghazikhani, M.; Taffazoli, D.; Manshori, N.

    2002-01-01

    The role of ambient temperature in determining the performance of GE-F5 gas turbine is analysed by investigating the Shirvan gas turbine power plant 10 MW , 15 MW and 20 MW power output. These parameters have been brought as a function of ambient temperature. The results show when ambient temperature increases 1 deg C, The compressor pressure decreases about 20 k Pa, compressor outlet temperature increases about 1.13 deg C and exhaust temperature increases about 2.5 deg C. It is revealed that variations are due to decreasing the efficiency of compressor and less due to mass flow rate of air reduction as ambient temperature increases at constant power output. The results shows cycle efficiency reduces 3% with increasing 50 of ambient temperature, also the m increases as ambient temperature increase for constant turbine work. These are also because of reducing the compressor efficiency as ambient temperature increases

  7. Multi-spectral pyrometer for gas turbine blade temperature measurement

    Science.gov (United States)

    Gao, Shan; Wang, Lixin; Feng, Chi

    2014-09-01

    To achieve the highest possible turbine inlet temperature requires to accurately measuring the turbine blade temperature. If the temperature of blade frequent beyond the design limits, it will seriously reduce the service life. The problem for the accuracy of the temperature measurement includes the value of the target surface emissivity is unknown and the emissivity model is variability and the thermal radiation of the high temperature environment. In this paper, the multi-spectral pyrometer is designed provided mainly for range 500-1000°, and present a model corrected in terms of the error due to the reflected radiation only base on the turbine geometry and the physical properties of the material. Under different working conditions, the method can reduce the measurement error from the reflect radiation of vanes, make measurement closer to the actual temperature of the blade and calculating the corresponding model through genetic algorithm. The experiment shows that this method has higher accuracy measurements.

  8. High-Temperature, High-Bandwidth Fiber Optic Pressure and Temperature Sensors for Gas Turbine Applications

    National Research Council Canada - National Science Library

    Fielder, Robert S; Palmer, Matthew E

    2003-01-01

    The accurate measurement of gas flow conditions in the compressor, combustors, and turbines of gas turbine engines is important to assess performance, predict failure, and facilitate data-driven maintenance...

  9. Basin-Wide Temperature Constraints On Gas Hydrate Stability In The Gulf Of Mexico

    Science.gov (United States)

    MacDonald, I. R.; Reagan, M. T.; Guinasso, N. L.; Garcia-Pineda, O. G.

    2012-12-01

    Gas hydrate deposits commonly occur at the seafloor-water interface on marine margins. They are especially prevalent in the Gulf of Mexico where they are associated with natural oil seeps. The stability of these deposits is potentially challenged by fluctuations in bottom water temperature, on an annual time-scale, and under the long-term influence of climate change. We mapped the locations of natural oil seeps where shallow gas hydrate deposits are known to occur across the entire Gulf of Mexico basin based on a comprehensive review of synthetic aperture radar (SAR) data (~200 images). We prepared a bottom water temperature map based on the archive of CTD casts from the Gulf (~6000 records). Comparing the distribution of gas hydrate deposits with predicted bottom water temperature, we find that a broad area of the upper slope lies above the theoretical stability horizon for structure 1 gas hydrate, while all sites where gas hydrate deposits occur are within the stability horizon for structure 2 gas hydrate. This is consistent with analytical results that structure 2 gas hydrates predominate on the upper slope (Klapp et al., 2010), where bottom water temperatures fluctuate over a 7 to 10 C range (approx. 600 m depth), while pure structure 1 hydrates are found at greater depths (approx. 3000 m). Where higher hydrocarbon gases are available, formation of structure 2 gas hydrate should significantly increase the resistance of shallow gas hydrate deposits to destabilizing effects variable or increasing bottom water temperature. Klapp, S.A., Bohrmann, G., Kuhs, W.F., Murshed, M.M., Pape, T., Klein, H., Techmer, K.S., Heeschen, K.U., and Abegg, F., 2010, Microstructures of structure I and II gas hydrates from the Gulf of Mexico: Marine and Petroleum Geology, v. 27, p. 116-125.Bottom temperature and pressure for Gulf of Mexico gas hydrate outcrops and stability horizons for sI and sII hydrate.

  10. Current correlation functions of ideal Fermi gas at finite temperature

    Indian Academy of Sciences (India)

    in the study of time dependent density functional theory [5] due to the work of Vignale and. Kohn [6,7]. They obtained ... part has relevance to the study of viscous effects [10] in the electron gas and to the dia- magnetic ... is found that the diamagnetic susceptibility, related to the transverse part, smoothly cross over from ...

  11. Exhaust Gas Temperature Measurements in Diagnostics of Turbocharged Marine Internal Combustion Engines Part I Standard Measurements

    Directory of Open Access Journals (Sweden)

    Korczewski Zbigniew

    2015-01-01

    Full Text Available The article discusses the problem of diagnostic informativeness of exhaust gas temperature measurements in turbocharged marine internal combustion engines. Theoretical principles of the process of exhaust gas flow in turbocharger inlet channels are analysed in its dynamic and energetic aspects. Diagnostic parameters are defined which enable to formulate general evaluation of technical condition of the engine based on standard online measurements of the exhaust gas temperature. A proposal is made to extend the parametric methods of diagnosing workspaces in turbocharged marine engines by analysing time-histories of enthalpy changes of the exhaust gas flowing to the turbocompressor turbine. Such a time-history can be worked out based on dynamic measurements of the exhaust gas temperature, performed using a specially designed sheathed thermocouple.

  12. Exhaust Gas Temperature Measurements in Diagnostics of Turbocharged Marine Internal Combustion Engines Part II Dynamic Measurements

    Directory of Open Access Journals (Sweden)

    Korczewski Zbigniew

    2016-01-01

    Full Text Available The second part of the article describes the technology of marine engine diagnostics making use of dynamic measurements of the exhaust gas temperature. Little-known achievements of Prof. S. Rutkowski of the Naval College in Gdynia (now: Polish Naval Academy in this area are presented. A novel approach is proposed which consists in the use of the measured exhaust gas temperature dynamics for qualitative and quantitative assessment of the enthalpy flux of successive pressure pulses of the exhaust gas supplying the marine engine turbocompressor. General design assumptions are presented for the measuring and diagnostic system which makes use of a sheathed thermocouple installed in the engine exhaust gas manifold. The corrected thermal inertia of the thermocouple enables to reproduce a real time-history of exhaust gas temperature changes.

  13. Cleanup of radioactivity contamination in environment

    International Nuclear Information System (INIS)

    Kosako, Toshiso

    1994-01-01

    Environmental radioactivity cleanup is needed under a large scale accident in a reactor or in an RI irradiation facility which associates big disperse of radioactivities. Here, the fundamental concept including a radiation protection target, a period classification, planning, an information data base, etc. Then, the methods and measuring instruments on radioactivity contamination and the cleanup procedure are explained. Finally, the real site examples of accidental cleanup are presented for a future discussion. (author)

  14. HANFORD SITE CENTRAL PLATEAU CLEANUP COMPLETION STRATEGY

    International Nuclear Information System (INIS)

    Bergman, T.B.

    2011-01-01

    Cleanup of the Hanford Site is a complex and challenging undertaking. The U.S. Department of Energy (DOE) has developed a comprehensive vision for completing Hanford's cleanup mission including transition to post-cleanup activities. This vision includes 3 principle components of cleanup: the ∼200 square miles ofland adjacent to the Columbia River, known as the River Corridor; the 75 square miles of land in the center of the Hanford Site, where the majority of the reprocessing and waste management activities have occurred, known as the Central Plateau; and the stored reprocessing wastes in the Central Plateau, the Tank Wastes. Cleanup of the River Corridor is well underway and is progressing towards completion of most cleanup actions by 2015. Tank waste cleanup is progressing on a longer schedule due to the complexity of the mission, with construction of the largest nuclear construction project in the United States, the Waste Treatment Plant, over 50% complete. With the progress on the River Corridor and Tank Waste, it is time to place increased emphasis on moving forward with cleanup of the Central Plateau. Cleanup of the Hanford Site has been proceeding under a framework defmed in the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement). In early 2009, the DOE, the State of Washington Department of Ecology, and the U.S. Environmental Protection Agency signed an Agreement in Principle in which the parties recognized the need to develop a more comprehensive strategy for cleanup of the Central Plateau. DOE agreed to develop a Central Plateau Cleanup Completion Strategy as a starting point for discussions. This DOE Strategy was the basis for negotiations between the Parties, discussions with the State of Oregon, the Hanford Advisory Board, and other Stakeholder groups (including open public meetings), and consultation with the Tribal Nations. The change packages to incorporate the Central Plateau Cleanup Completion Strategy were signed by the

  15. Effect of pairwise additivity on finite-temperature behavior of classical ideal gas

    Science.gov (United States)

    Shekaari, Ashkan; Jafari, Mahmoud

    2018-05-01

    Finite-temperature molecular dynamics simulations have been applied to inquire into the effect of pairwise additivity on the behavior of classical ideal gas within the temperature range of T = 250-4000 K via applying a variety of pair potentials and then examining the temperature dependence of a number of thermodynamical properties. Examining the compressibility factor reveals the most deviation from ideal-gas behavior for the Lennard-Jones system mainly due to the presence of both the attractive and repulsive terms. The systems with either attractive or repulsive intermolecular potentials are found to present no resemblance to real gases, but the most similarity to the ideal one as temperature rises.

  16. A design method to isothermalize the core of high-temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Takano, M.; Sawa, K.

    1987-01-01

    A practical design method is developed to isothermalize the core of block-type high-temperature gas-cooled reactors (HTGRs). Isothermalization plays an important role in increasing the design margin on fuel temperature. In this method, the fuel enrichment and the size and boron content of the burnable poison rod are determined over the core blockwise so that the axially exponential and radially flat power distribution are kept from the beginning to the end of core life. The method enables conventional HTGRs to raise the outlet gas temperature without increasing the maximum fuel temperature

  17. The early history of high-temperature helium gas-cooled nuclear power reactors

    International Nuclear Information System (INIS)

    Simnad, M.T.; California Univ., San Diego, La Jolla, CA

    1991-01-01

    The original concepts in the proposals for high-temperature helium gas-cooled power reactors by Farrington Daniels, during the decade 1944-1955, are summarized. The early research on the development of the helium gas-cooled power reactors is reviewed, and the operational experiences with the first generation of HTGRs are discussed. (author)

  18. Articulated Multimedia Physics, Lesson 14, Gases, The Gas Laws, and Absolute Temperature.

    Science.gov (United States)

    New York Inst. of Tech., Old Westbury.

    As the fourteenth lesson of the Articulated Multimedia Physics Course, instructional materials are presented in this study guide with relation to gases, gas laws, and absolute temperature. The topics are concerned with the kinetic theory of gases, thermometric scales, Charles' law, ideal gases, Boyle's law, absolute zero, and gas pressures. The…

  19. Effect of Temperature Shock and Inventory Surprises on Natural Gas and Heating Oil Futures Returns

    Science.gov (United States)

    Hu, John Wei-Shan; Lin, Chien-Yu

    2014-01-01

    The aim of this paper is to examine the impact of temperature shock on both near-month and far-month natural gas and heating oil futures returns by extending the weather and storage models of the previous study. Several notable findings from the empirical studies are presented. First, the expected temperature shock significantly and positively affects both the near-month and far-month natural gas and heating oil futures returns. Next, significant temperature shock has effect on both the conditional mean and volatility of natural gas and heating oil prices. The results indicate that expected inventory surprises significantly and negatively affects the far-month natural gas futures returns. Moreover, volatility of natural gas futures returns is higher on Thursdays and that of near-month heating oil futures returns is higher on Wednesdays than other days. Finally, it is found that storage announcement for natural gas significantly affects near-month and far-month natural gas futures returns. Furthermore, both natural gas and heating oil futures returns are affected more by the weighted average temperature reported by multiple weather reporting stations than that reported by a single weather reporting station. PMID:25133233

  20. Effect of temperature and α-irradiation on gas permeability for ...

    Indian Academy of Sciences (India)

    Unknown

    polymer membranes that help separate gas. In addition to the chemical composition, the transport properties are related to the main characteristics of copolymers like the glass transition temperature, crystallinity and crosslink- ing ratio. Gas diffusion through polymers is related to the activation energy (Pesiri et al 2003).

  1. Thermodynamics of high-temperature and high-density hadron gas by a numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Nobuo; Miyamura, Osamu [Hiroshima Univ., Higashi-Hiroshima (Japan). Dept. of Physics

    1998-07-01

    We study thermodynamical properties of hot and dense hadronic gas an event generator URASiMA. In our results, the increase of temperature is suppressed. It indicates that hot and dense hadronic gas has a large specific heat at constant volume. (author)

  2. Temperature-dependent gas transport and its correlation with kinetic ...

    Indian Academy of Sciences (India)

    2017-05-20

    May 20, 2017 ... have been made to see this trade-off relation at relatively higher temperature. It is found that selectivity ... acceptable due to low capital cost, less energy requirement ... in solubility, with increased permeability due to interac-.

  3. A method for calculating the gas volume proportions and inhalation temperature of inert gas mixtures allowing reaching normothermic or hypothermic target body temperature in the awake rat

    Directory of Open Access Journals (Sweden)

    Jacques H Abraini

    2017-01-01

    Full Text Available The noble gases xenon (Xe and helium (He are known to possess neuroprotective properties. Xe is considered the golden standard neuroprotective gas. However, Xe has a higher molecular weight and lower thermal conductivity and specific heat than those of nitrogen, the main diluent of oxygen (O2 in air, conditions that could impair or at least reduce the intrinsic neuroprotective properties of Xe by increasing the critical care patient's respiratory workload and body temperature. In contrast, He has a lower molecular weight and higher thermal conductivity and specific heat than those of nitrogen, but is unfortunately far less potent than Xe at providing neuroprotection. Therefore, combining Xe with He could allow obtaining, depending on the gas inhalation temperature and composition, gas mixtures with neutral or hypothermic properties, the latter being advantageous in term of neuroprotection. However, calculating the thermal properties of a mixture, whatever the substances – gases, metals, rubbers, etc. – is not trivial. To answer this question, we provide a graphical method to assess the volume proportions of Xe, He and O2 that a gas mixture should contain, and the inhalation temperature to which it should be administered to allow a clinician to maintain the patient at a target body temperature.

  4. Comparison study for the CCME reference method for determination of PHC in soil by using internal and external standard methods and by using silica gel column cleanup and in-situ silica gel cleanup methods

    International Nuclear Information System (INIS)

    Wang, Z.; Fingas, M.; Sigouin, L.; Yang, C.; Hollebone, B.

    2003-01-01

    The assessment, cleanup, and remediation of hydrocarbon contaminated sites is covered in the Reference Method for Canada-Wide Standard for Petroleum Hydrocarbons-Tier 1 Method. It replaces several analytical methods used in the past by some laboratories and jurisdictions in Canada. The authors conducted two comparative evaluations to validate the Tier 1 Analytical Method. The first compared the Internal and External Standard Methods, and the second compared the Silica Gel Column Cleanup Method with the In-situ Silica Gel Cleanup Method. The Canadian Council of Ministers of the Environment (CCME) Tier 1 Method recommends and requires the External Standard Method to determine petroleum hydrocarbons (PHC) in soil samples. The Internal Method is widely used to quantify various organic and inorganic pollutants in environmental samples. The Tier 1 Method offers two options for the same extract cleanup. They are: Option A - In-situ Silica Gel Cleanup, and Option B - Silica Gel Column Cleanup. Linearity, precision, and PHC quantification results were the parameters considered for diesel and motor oil solutions, for diesel spiked soil samples, and for motor oil spiked soil samples. It was concluded that both the External and Internal Standard Methods for gas chromatograph (GC) determination of PHC in soil possess their own advantages. The PHC results obtained using the In-Situ Silica Gel Cleanup Method were lower than those obtained with the Silica Gel Column Cleanup Methods. The more efficient and effective sample cleanup method proved to be the Silica Gel Column Method. 13 refs., 7 tabs., 7 figs

  5. Minimization of steam requirements and enhancement of water-gas shift reaction with warm gas temperature CO2 removal

    Science.gov (United States)

    Siriwardane, Ranjani V; Fisher, II, James C

    2013-12-31

    The disclosure utilizes a hydroxide sorbent for humidification and CO.sub.2 removal from a gaseous stream comprised of CO and CO.sub.2 prior to entry into a water-gas-shift reactor, in order to decrease CO.sub.2 concentration and increase H.sub.2O concentration and shift the water-gas shift reaction toward the forward reaction products CO.sub.2 and H.sub.2. The hydroxide sorbent may be utilized for absorbtion of CO.sub.2 exiting the water-gas shift reactor, producing an enriched H.sub.2 stream. The disclosure further provides for regeneration of the hydroxide sorbent at temperature approximating water-gas shift conditions, and for utilizing H.sub.2O product liberated as a result of the CO.sub.2 absorption.

  6. Development of tritium cleanup system for LHD

    International Nuclear Information System (INIS)

    Sakuma, Yoichi; Kawano, Takao; Shibuya, Mamoru; Kabutomori, Toshiki

    2000-01-01

    Energy is vital for humans and we have been consuming a large amount of fossil fuel especially from the beginning of the industrial revolution. Nowadays its huge consumption has however come to threaten our life and we have to prepare nonfossil fuels, for instance solar energy, biomass energy, nuclear energy and so on. Fusion energy is an unlimited resource and one of the strongest candidates of the future energy source. At the National Institute for Fusion Science (referred to as 'NIFS' hereafter), we have constructed a new fusion experimental device called large helical device (referred to as 'LHD' hereafter) in 1998. The device will generate a small amount of tritium, as a fusion product. In order to remove it from the exhaust gas, we have designed a tritium cleanup system based on a new concept. This system is mainly composed of a palladium permeater, a decomposer and hydrogen absorbing alloys. It may perfectly recover the tritium from exhaust gas without oxidizing it. This system is applicable for the future needs at fusion power plants. In order to remove tritium discharged from fusion experimental facilities, it is usual to employ a system by which tritiated constituents, in various chemical forms, are entirely converted to a form of water vapor by catalytic oxidation. The water vapor containing tritiated form is then absorbed by molecular sieve (referred to as 'wet system' hereafter). However, in the case of LHD, it is not rational to deliberately convert the discharged tritium into the water vapor, because the tritium discharged from LHD is almost in a form of hydrogen molecules. Moreover, the tritium in the form of water vapor affects the human body 18000 times stronger than that of hydrogen molecules. In accordance with these view points, we have developed another type of tritium cleanup system based on a new concept, in which hydrogen molecules including tritiated ones (HT, DT and T 2 ) found in the exhaust gas of LHD are directly fixed to hydrogen

  7. Model simulation for high-temperature gas desulphurization processes

    Energy Technology Data Exchange (ETDEWEB)

    Tonini; Zaccagnini; Berg; Vitolo; Tartarelli; Zeppi (Struttura Informatica, Florence (Italy))

    1993-01-01

    Metal oxides such as zinc ferrite, zinc titanate and tin oxide have been identified as promising adsorbent materials in the removal of sulphur compounds from hot coal gas in power generation operations. A mathematical model for the sulfidation phase in fixed, moving and fluidised bed reactors has been developed. This paper presents kinetic models of spherical sorbent particles applicable to all reactor configurations and a mathematical model limited to the moving bed reactor. 10 refs., 5 figs.

  8. Program for aerodynamic performance tests of helium gas compressor model of the gas turbine high temperature reactor (GTHTR300)

    International Nuclear Information System (INIS)

    Takada, Shoji; Takizuka, Takakazu; Kunimoto, Kazuhiko; Yan, Xing; Itaka, Hidehiko; Mori, Eiji

    2003-01-01

    Research and development program for helium gas compressor aerodynamics was planned for the power conversion system of the Gas Turbine High Temperature Reactor (GTHTR300). The axial compressor with polytropic efficiency of 90% and surge margin more than 30% was designed with 3-dimensional aerodynamic design. Performance and surge margin of the helium gas compressor tends to be lower due to the higher boss ratio which makes the tip clearance wide relative to the blade height, as well as due to a larger number of stages. The compressor was designed on the basis of methods and data for the aerodynamic design of industrial open-cycle gas-turbine. To validate the design of the helium gas compressor of the GTHTR300, aerodynamic performance tests were planned, and a 1/3-scale, 4-stage compressor model was designed. In the tests, the performance data of the helium gas compressor model will be acquired by using helium gas as a working fluid. The maximum design pressure at the model inlet is 0.88 MPa, which allows the Reynolds number to be sufficiently high. The present study is entrusted from the Ministry of Education, Culture, Sports, Science and Technology of Japan. (author)

  9. Experimental Study of Natural Gas Temperature Effects on the Flame Luminosity and No Emission

    Directory of Open Access Journals (Sweden)

    S. M. Javadi

    2012-06-01

    Full Text Available The flame radiation enhancement in gas-fired furnaces significantly improves the thermal efficiency without significantly affecting the NOx emissions. In this paper, the effects of inlet natural gas preheating on the flame luminosity, overall boiler efficiency, and NO emission in a 120 kW boiler have been investigated experimentally. Flame radiation is measured by use of laboratory pyranometer with photovoltaic sensor. A Testo350XL gas analyzer is also used for measuring the temperature and combustion species. The fuel is preheated from the room temperature to 350°C. The experimental measurements show that the preheating of natural gas up to about 240°C has no considerable effect on the flame luminosity. The results show that increasing the inlet gas temperature from 240°C, abruptly increases the flame luminosity. This luminosity increase enhances the boiler efficiency and also causes significant reduction in flame temperature and NO emission. The results show that increasing the inlet gas temperature from 240°C to 300°C increases the flame luminous radiation by 60% and boiler efficiency by 20%; while the maximum flame temperature and the boiler NO emission show a 10% and 8% decrease respectively.

  10. Precise measurements of neutral gas temperature using Fiber Bragg Grating sensor in Argon capacitively coupled plasmas

    Science.gov (United States)

    Han, Daoman; Liu, Zigeng; Liu, Yongxin; Peng, Wei; Wang, Younian

    2016-09-01

    Neutral gas temperature was measured using Fiber Bragg Grating sensor (FBGs) in capacitively coupled argon plasmas. Thermometry is based on the thermal equilibrium between the sensor and neutral gases, which is found to become faster with increasing pressure. It is also observed that the neutral gas temperature is higher than the room temperature by 10 120 °depending on the experiental conditions, and gas temperature shows significant non-uniformity in space. In addition, radial profiles of neutral temperature at different pressures, resemble these of ion density, obtained by a floating double probe. Specifically, at low pressure, neutral gas temperature and ion density peak at the center of the reactor, while the peak appears at the edge of the electrode at higher pressure. The neutral gas heating is mainly caused by the elastic collisions of Ar + with neutral gas atoms in the sheath region after Ar + gaining a certain energy. This work was supported by the National Natural Science Foundation of China (NSFC) (Grants No. 11335004, 11405018, and 61137005).

  11. Experimental Evaluation of Cermet Turbine Stator Blades for Use at Elevated Gas Temperatures

    Science.gov (United States)

    Chiarito, Patrick T.; Johnston, James R.

    1959-01-01

    The suitability of cermets for turbine stator blades of a modified turbojet engine was determined at an average turbine-inlet-gas temperature of 2000 F. Such an increase in temperature would yield a premium in thrust from a service engine. Because the cermet blades require no cooling, all the available compressor bleed air could be used to cool a turbine made from conventional ductile alloys. Cermet blades were first run in 100-hour endurance tests at normal gas temperatures in order to evaluate two methods for mounting them. The elevated gas-temperature test was then run using the method of support considered best for high-temperature operation. After 52 hours at 2000 F, one of the group of four cermet blades fractured probably because of end loads resulting from thermal distortion of the spacer band of the nozzle diaphragm. Improved design of a service engine would preclude this cause of premature failure.

  12. Atomic and molecular hydrogen gas temperatures in a low-pressure helicon plasma

    Science.gov (United States)

    Samuell, Cameron M.; Corr, Cormac S.

    2015-08-01

    Neutral gas temperatures in hydrogen plasmas are important for experimental and modelling efforts in fusion technology, plasma processing, and surface modification applications. To provide values relevant to these application areas, neutral gas temperatures were measured in a low pressure (radiofrequency helicon discharge using spectroscopic techniques. The atomic and molecular species were not found to be in thermal equilibrium with the atomic temperature being mostly larger then the molecular temperature. In low power operation (measurements near a graphite target demonstrated localised cooling near the sample surface. The temporal evolution of the molecular gas temperature during a high power 1.1 ms plasma pulse was also investigated and found to vary considerably as a function of pressure.

  13. Selective Sensing of Gas Mixture via a Temperature Modulation Approach: New Strategy for Potentiometric Gas Sensor Obtaining Satisfactory Discriminating Features.

    Science.gov (United States)

    Li, Fu-An; Jin, Han; Wang, Jinxia; Zou, Jie; Jian, Jiawen

    2017-03-12

    A new strategy to discriminate four types of hazardous gases is proposed in this research. Through modulating the operating temperature and the processing response signal with a pattern recognition algorithm, a gas sensor consisting of a single sensing electrode, i.e., ZnO/In₂O₃ composite, is designed to differentiate NO₂, NH₃, C₃H₆, CO within the level of 50-400 ppm. Results indicate that with adding 15 wt.% ZnO to In₂O₃, the sensor fabricated at 900 °C shows optimal sensing characteristics in detecting all the studied gases. Moreover, with the aid of the principle component analysis (PCA) algorithm, the sensor operating in the temperature modulation mode demonstrates acceptable discrimination features. The satisfactory discrimination features disclose the future that it is possible to differentiate gas mixture efficiently through operating a single electrode sensor at temperature modulation mode.

  14. Simulation for temperature changing investigation at RSG-GAS cooling system

    International Nuclear Information System (INIS)

    Utaja

    2002-01-01

    The RSG-GAS cooling system considers of primary and secondary system, is used for heat rejection from reactor core to the atmosphere. For temperature changing investigation cause by atmospherics condition changing or coolant flow rate changing, is more safe done by simulation. This paper describes the simulation for determine the RSG-GAS coolant temperature changing base on heat exchange and cooling tower characteristic. The simulation is done by computer programme running under WINDOWS 95 or higher. The temperature changing is based on heat transfer process on heat exchanger and cooling tower. The simulation will show the water tank temperature changing caused by the temperature and humidity of the atmosphere or by coolant flow rate changing. For example the humidity changing from 60% to 80% atmospherics temperature 30 oC and 32400 k Watt power will change the tank temperature from 37,97 oC to 40,03 oC

  15. Membrane steam reforming of natural gas for hydrogen production by utilization of medium temperature nuclear reactor

    International Nuclear Information System (INIS)

    Djati Hoesen Salimy

    2010-01-01

    The assessment of steam reforming process with membrane reactor for hydrogen production by utilizing of medium temperature nuclear reactor has been carried out. Difference with the conventional process of natural gas steam reforming that operates at high temperature (800-1000°C), the process with membrane reactor operates at lower temperature (~500°C). This condition is possible because the use of perm-selective membrane that separate product simultaneously in reactor, drive the optimum conversion at the lower temperature. Besides that, membrane reactor also acts the role of separation unit, so the plant will be more compact. From the point of nuclear heat utilization, the low temperature of process opens the chance of medium temperature nuclear reactor utilization as heat source. Couple the medium temperature nuclear reactor with the process give the advantage from the point of saving fossil fuel that give direct implication of decreasing green house gas emission. (author)

  16. Kinetic Energy of a Trapped Fermi Gas at Finite Temperature

    Science.gov (United States)

    Grela, Jacek; Majumdar, Satya N.; Schehr, Grégory

    2017-09-01

    We study the statistics of the kinetic (or, equivalently, potential) energy for N noninteracting fermions in a 1 d harmonic trap of frequency ω at finite temperature T . Remarkably, we find an exact solution for the full distribution of the kinetic energy, at any temperature T and for any N , using a nontrivial mapping to an integrable Calogero-Moser-Sutherland model. As a function of temperature T and for large N , we identify (i) a quantum regime, for T ˜ℏω , where quantum fluctuations dominate and (ii) a thermal regime, for T ˜N ℏω , governed by thermal fluctuations. We show how the mean and the variance as well as the large deviation function associated with the distribution of the kinetic energy cross over from the quantum to the thermal regime as T increases.

  17. Electron temperature measurement of tungsten inert gas arcs

    International Nuclear Information System (INIS)

    Tanaka, Manabu; Tashiro, Shinichi

    2008-01-01

    In order to make clear the physical grounds of deviations from LTE (Local Thermodynamic Equilibrium) in the atmospheric helium TIG arcs electron temperature and LTE temperature obtained from electron number density were measured by using of line-profile analysis of the laser scattering method without an assumption of LTE. The experimental results showed that in comparison with the argon TIG arcs, the region where a deviation from LTE occurs tends to expand in higher arc current because the plasma reaches the similar state to LTE within shorter distance from the cathode due to the slower cathode jet velocity

  18. Low temperature techniques for natural gas purification and LNG production: An energy and exergy analysis

    International Nuclear Information System (INIS)

    Baccanelli, Margaret; Langé, Stefano; Rocco, Matteo V.; Pellegrini, Laura A.; Colombo, Emanuela

    2016-01-01

    Highlights: • Low-temperature processes for of high CO_2 content natural gas have been modelled. • Energy and exergy analyses have been performed. • The Dual Pressure distillation scheme has the best thermodynamic performances. • There is a synergy between cryogenic natural gas purification and LNG production. - Abstract: Due to the rapid increase of the World’s primary energy demand of the last decades, low-temperature processes for the purification of natural gas streams with high carbon dioxide content has gained interest, since they allow to make profitable exploitation of low-quality gas reserves. Low temperature purification processes allow the direct production of a methane stream at high purity and at low-temperature, suitable conditions for the direct synergistic integration with natural gas cryogenic liquefaction processes, while CO_2 is obtained in liquid phase and under pressure. In this way, it can be pumped for transportation, avoiding significant compression costs as for classical CO_2 capture units (where carbon dioxide is discharged in gas phase and at atmospheric pressure), and further uses such as Enhanced Oil Recovery (EOR) or underground storage. In this paper, the three most common natural gas low-temperature purification techniques have been modelled and their performances have been evaluated through energy and exergy analyses. Specifically, the dual pressure low-temperature distillation process, the anti-sublimation process and a hybrid configuration have been considered. It is found that the dual pressure low-temperature distillation scheme reach the highest thermodynamic performances, resulting in the best values of exergy efficiency and equivalent methane requirements with respect to the other configurations. This is mainly due to the distributed temperature profile along a distillation column, resulting in a less irreversible heat exchanging process.

  19. Failure mechanisms in high temperature gas cooled reactor fuel particles

    International Nuclear Information System (INIS)

    Soo, P.; Uneberg, G.; Sabatini, R.L.; Schweitzer, D.G.

    1979-01-01

    BISO coated UO 2 and ThO 2 particles were heated to high temperatures to determine failure mechanisms during hypothetical loss of coolant scenarios. Rapid failure begins when the oxides are reduced to liquid carbides. Several failure mechanisms are applicable, ranging from hole and crack formation in the coatings to catastrophic particle disintegration

  20. Temperature dependence of the particle/gas partition coefficient: An application to predict indoor gas-phase concentrations of semi-volatile organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Wenjuan, E-mail: Wenjuan.Wei@cstb.fr [University of Paris-Est, Scientific and Technical Center for Building (CSTB), Health and Comfort Department, French Indoor Air Quality Observatory (OQAI), 84 Avenue Jean Jaurès, Champs sur Marne, 77447 Marne la Vallée Cedex 2 (France); Mandin, Corinne [University of Paris-Est, Scientific and Technical Center for Building (CSTB), Health and Comfort Department, French Indoor Air Quality Observatory (OQAI), 84 Avenue Jean Jaurès, Champs sur Marne, 77447 Marne la Vallée Cedex 2 (France); INSERM-U1085, Irset-Research Institute for Environmental and Occupational Health, Rennes (France); LERES-Environment and Health Research Laboratory (Irset and EHESP Technologic Platform), Rennes (France); Blanchard, Olivier [EHESP-School of Public Health, Sorbonne Paris Cité, Rennes (France); INSERM-U1085, Irset-Research Institute for Environmental and Occupational Health, Rennes (France); Mercier, Fabien [EHESP-School of Public Health, Sorbonne Paris Cité, Rennes (France); LERES-Environment and Health Research Laboratory (Irset and EHESP Technologic Platform), Rennes (France); INSERM-U1085, Irset-Research Institute for Environmental and Occupational Health, Rennes (France); Pelletier, Maud [EHESP-School of Public Health, Sorbonne Paris Cité, Rennes (France); INSERM-U1085, Irset-Research Institute for Environmental and Occupational Health, Rennes (France); Le Bot, Barbara [EHESP-School of Public Health, Sorbonne Paris Cité, Rennes (France); LERES-Environment and Health Research Laboratory (Irset and EHESP Technologic Platform), Rennes (France); INSERM-U1085, Irset-Research Institute for Environmental and Occupational Health, Rennes (France); and others

    2016-09-01

    The indoor gas-phase concentrations of semi-volatile organic compounds (SVOCs) can be predicted from their respective concentrations in airborne particles by applying the particle/gas partitioning equilibrium. The temperature used for partitioning is often set to 25 °C. However, indoor temperatures frequently differ from this reference value. This assumption may result in errors in the predicted equilibrium gas-phase SVOC concentrations. To improve the prediction model, the temperature dependence of the particle/gas partition coefficient must be addressed. In this paper, a theoretical relationship between the particle/gas partition coefficient and temperature was developed based on the SVOC absorptive mechanism. The SVOC particle/gas partition coefficients predicted by employing the derived theoretical relationship agree well with the experimental data retrieved from the literature (R > 0.93). The influence of temperature on the equilibrium gas-phase SVOC concentration was quantified by a dimensionless analysis of the derived relationship between the SVOC particle/gas partition coefficient and temperature. The predicted equilibrium gas-phase SVOC concentration decreased by between 31% and 53% when the temperature was lowered by 6 °C, while it increased by up to 750% when the indoor temperature increased from 15 °C to 30 °C. - Highlights: • A theoretical relationship between K{sub p} and temperature was developed. • The relationship was based on the SVOC absorptive mechanism. • The temperature impact was quantified by a dimensionless analysis.

  1. Conditions for lowering the flue gas temperature; Foerutsaettning foer saenkning av roekgastemperatur

    Energy Technology Data Exchange (ETDEWEB)

    Nordling, Magnus

    2012-02-15

    In heat and power production, the efficiency of the power plant increases the larger share of heat from the flue gas that is converted to power. However, this also implies that the temperature of the heat exchanging surfaces is lowered. If the temperature is lowered to a temperature below the dew point of the flue gas, this would result in condensation of the gas, which in turn elevates the risk of serious corrosion attack on the surfaces where condensation occurs. Thus, it is important to determine the dew point temperature. One way of determining the dew point temperature is to use data on composition of the fuel together with operation parameters of the plant, thus calculating the dew point temperature. However, this calculation of the dew point is not so reliable, especially if hygroscopic salts are present. Therefore, for safety reasons, the temperature of the flue gas is kept well above the dew point temperature. This results in lowered over-all efficiency of the plant. It could also be expected that for a certain plant, some construction materials under certain operation conditions would have corrosion characteristics that may allow condensation on the surface without severe and unpredictable corrosion attack. However, by only using operation parameters and fuel composition, it is even harder to predict the composition of the condensate at different operation temperatures than to calculate the dew point temperature. If the dew point temperature was known with a greater certainty, the temperature of the flue gas could be kept lower, just above the estimated value of the dew point, without any increased risk for condensation. If, in addition, also the resulting composition of the condensate at different temperatures below the dew point is known, it can be predicted if the construction materials of the flue gas channel were compatible with the formed condensate. If they are compatible, the flue gas temperature can be further lowered from the dew point

  2. Moderate temperature gas purification system: Application to high calorific coal-derived fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, M.; Shirai, H.; Nunokawa, M. [Central Research Institute of Electric Power Industry, Kanagawa (Japan)

    2008-01-15

    Simultaneous removal of dust, alkaline and alkaline-earth metals, halides and sulfur compounds is required to enlarge application of coal-derived gas to the high-temperature fuel cells and the fuel synthesis through chemical processing. Because high calorific fuel gas, such as oxygen-blown coal gas, has high carbon monoxide content, high-temperature (above 450{sup o}C) gas purification system is always subjected to the carbon deposition. We suggest moderate temperature (around 300{sup o}C) operation of the gas purification system to avoid the harmful disproportionation reaction and efficient removal of the various contaminants. Because the reaction rate is predominant to the performance of contaminant removal in the moderate temperature gas purification system, we evaluated the chemical removal processes; performance of the removal processes for halides and sulfur compounds was experimentally evaluated. The halide removal process with sodium aluminate sorbent had potential performance at around 300{sup o}C. The sulfur removal process with zinc ferrite sorbent was also applicable to the temperature range, though the reaction kinetics of the sorbent is essential to be approved.

  3. Moderate temperature gas purification system: application to high calorific coal derived fuel

    Energy Technology Data Exchange (ETDEWEB)

    M. Kobayashi; H. Shirai; M. Nunokawa [Central Research Institute of Electric Power Industry (CRIEPI), Kanagawa (Japan)

    2005-07-01

    Simultaneous removal of dust, alkaline and alkaline-earth metals, halides and sulfur compounds is required to enlarge application of coal-derived gas to the high temperature fuel cells and the fuel synthesis through chemical processing. Because high calorific fuel gas, such as oxygen-blown coal gas, has high carbon monoxide content, high temperature gas purification system is always subjected to the carbon deposition and slippage of contaminant of high vapor pressure. It was suggested that moderate temperature operation of the gas purification system is applied to avoid the harmful disproportionation reaction and efficient removal of the various contaminants. To establish the moderate temperature gas purification system, the chemical-removal processes where the reaction rate is predominant to the performance of contaminant removal should be evaluated. Performance of the removal processes for halides and sulfur compounds were experimentally evaluated. The halide removal process with sodium based sorbent had potential good performance at around 300{sup o}C. The sulfur removal process was also applicable to the temperature range, although the improvement of the sulfidation reaction rate is considered to be essential. 11 refs., 8 figs., 1 tab.

  4. High temperature, high pressure gas loop - the Component Flow Test Loop (CFTL)

    International Nuclear Information System (INIS)

    Gat, U.; Sanders, J.P.; Young, H.C.

    1984-01-01

    The high-pressure, high-temperature, gas-circulating Component Flow Test Loop located at Oak Ridge National Laboratory was designed and constructed utilizing Section III of the ASME Boiler and Pressure Vessel Code. The quality assurance program for operating and testing is also based on applicable ASME standards. Power to a total of 5 MW is available to the test section, and an air-cooled heat exchanger rated at 4.4 MW serves as heat sink. The three gas-bearing, completely enclosed gas circulators provide a maximum flow of 0.47 m 3 /s at pressures to 10.7 MPa. The control system allows for fast transients in pressure, power, temperature, and flow; it also supports prolonged unattended steady-state operation. The data acquisition system can access and process 10,000 data points per second. High-temperature gas-cooled reactor components are being tested

  5. Temperature-modulated direct thermoelectric gas sensors: thermal modeling and results for fast hydrocarbon sensors

    International Nuclear Information System (INIS)

    Rettig, Frank; Moos, Ralf

    2009-01-01

    Direct thermoelectric gas sensors are a promising alternative to conductometric gas sensors. For accurate results, a temperature modulation technique in combination with a regression analysis is advantageous. However, the thermal time constant of screen-printed sensors is quite large. As a result, up to now the temperature modulation frequency (20 mHz) has been too low and the corresponding principle-related response time (50 s) has been too high for many applications. With a special design, respecting the physical properties of thermal waves and the use of signal processing similar to a lock-in-amplifier, it is possible to achieve response times of about 1 s. As a result, direct thermoelectric gas sensors with SnO 2 as a gas-sensitive material respond fast and are reproducible to the propane concentration in the ambient atmosphere. Due to the path-independent behavior of the thermovoltage and the temperature, the measured thermopower of two sensors is almost identical

  6. Comparative study on cleanup procedures for the determination of organophosphorus pesticides in vegetables

    International Nuclear Information System (INIS)

    Alvin, Chai Lian Kuet; Lau, Seng

    2008-01-01

    A study was carried out to compare the cleanup procedures for the determination of organophosphorus pesticides in vegetables. Eleven organophosphorus pesticides were extracted with acetone and methylene chloride. Extracts were cleanup by solid-phase extraction (SPE) mixed-mode column using quaternary amine and aminopropyl (SAX/ NH 2 ) or octadecyl (C 18 ) sorbents. The pesticides were determined by gas chromatography with flame photometric detector. The recovery results obtained from the SPE SAX/ NH 2 and C 18 cleanups in carrot, cucumber and green mustard samples were in the range of 71.0 % to 115 %. Lower recoveries were obtained for polar pesticides, methamidophos and dimethoate. These results were compared to the method currently used in the laboratory which does not include any cleanup. (author)

  7. Effects of Outside Air Temperature on Movement of Phosphine Gas in Concrete Elevator Bins

    Science.gov (United States)

    Studies that measured the movement and concentration of phosphine gas in upright concrete bins over time indicated that fumigant movement was dictated by air currents, which in turn, were a function of the difference between the average grain temperature and the average outside air temperature durin...

  8. Research and development for high temperature gas cooled reactor in Japan

    International Nuclear Information System (INIS)

    Taketani, K.

    1978-01-01

    The paper describes the current status of High Temperature Gas Cooled Reactor research and development work in Japan, with emphasis on the Experimental Very High Temperature Reactor (Exp. VHTR) to be built by Japan Atomic Energy Research Institute (JAERI) before the end of 1985. The necessity of construction of Exp. VHTR was explained from the points of Japanese energy problems and resources

  9. Plasmonic nanocomposite thin film enabled fiber optic sensors for simultaneous gas and temperature sensing at extreme temperatures.

    Science.gov (United States)

    Ohodnicki, Paul R; Buric, Michael P; Brown, Thomas D; Matranga, Christopher; Wang, Congjun; Baltrus, John; Andio, Mark

    2013-10-07

    Embedded sensors capable of operation in extreme environments including high temperatures, high pressures, and highly reducing, oxidizing and/or corrosive environments can make a significant impact on enhanced efficiencies and reduced greenhouse gas emissions of current and future fossil-based power generation systems. Relevant technologies can also be leveraged in a wide range of other applications with similar needs including nuclear power generation, industrial process monitoring and control, and aviation/aerospace. Here we describe a novel approach to embedded sensing under extreme temperature conditions by integration of Au-nanoparticle based plasmonic nanocomposite thin films with optical fibers in an evanescent wave absorption spectroscopy configuration. Such sensors can potentially enable simultaneous temperature and gas sensing at temperatures approaching 900-1000 °C in a manner compatible with embedded and distributed sensing approaches. The approach is demonstrated using the Au/SiO2 system deposited on silica-based optical fibers. Stability of optical fibers under relevant high temperature conditions and interactions with changing ambient gas atmospheres is an area requiring additional investigation and development but the simplicity of the sensor design makes it potentially cost-effective and may offer a potential for widespread deployment.

  10. The application of dynamic method for the temperature measurement of gas destruction in a plasma reactor

    International Nuclear Information System (INIS)

    Ryszard, Sarba

    2009-01-01

    This paper presents an experimental and theoretical study of the conversion of measuring probe temperature into hot gas temperature. The author gives a solution to the problem of a destruction temperature measurement in a plasma reactor. The temperature conversion is based on the thermodynamic similarity theory and statistical thermodynamics verification. The experimental measurements of the hot gas temperature have been made in the place where it considerably exceeds the melting point of the measuring probe material. The heat exchange phenomenon on the measuring probe's surface with the hot gas surrounding it is described by a forced convection equation. An analysis has been made of the heat flowing in and out of the measuring probe. The experimental part of the paper includes: an experimental measurement of gas velocity by means of luminous particles, a hot gas measurement for one distance from a nozzle and different diameters of the measuring probe, as well as different probing velocities. Numerical simulations have been made of the temperature distribution in a plasma jet. The experimental results are congruent with theoretical predictions. The aim of this research is a contribution to the structuring of a mathematical model of mass and energy balance in the processes of NHF 2 CL waste destruction.

  11. Temperature dependence of muonium reaction rates in the gas phase

    International Nuclear Information System (INIS)

    Fleming, D.G.; Garner, D.M.; Mikula, R.J.; British Columbia Univ., Vancouver

    1981-01-01

    A study of the temperature dependence of reaction rates has long been an important tool in establishing reaction pathways in chemical reactions. This is particularly true for the reactions of muonium (in comparison with those of hydrogen) since a measurement of the activation energy for chemical reaction is sensitive to both the height and the position of the potential barrier in the reaction plane. For collision controlled reactions, on the other hand, the reaction rate is expected to exhibit a weak T 1 sup(/) 2 dependence characteristic of the mean collision velocity. These concepts are discussed and their effects illustrated in a comparison of the chemical and spin exchange reaction rates of muonium and hydrogen in the temperature range approx.300-approx.500 K. (orig.)

  12. Gas Temperature and Radiative Heat Transfer in Oxy-fuel Flames

    DEFF Research Database (Denmark)

    Bäckström, Daniel; Johansson, Robert; Andersson, Klas

    This work presents measurements of the gas temperature, including fluctuations, and its influence on the radiative heat transfer in oxy-fuel flames. The measurements were carried out in the Chalmers 100 kW oxy-fuel test unit. The in-furnace gas temperature was measured by a suction pyrometer...... on the radiative heat transfer shows no effect of turbulence-radiation interaction. However, by comparing with temperature fluctuations in other flames it can be seen that the fluctuations measured here are relatively small. Further research is needed to clarify to which extent the applied methods can account...

  13. Gas temperature measurements in short duration turbomachinery test facilities

    Science.gov (United States)

    Cattafesta, L. N.; Epstein, A. H.

    1988-07-01

    Thermocouple rakes for use in short-duration turbomachinery test facilities have been developed using very fine thermocouples. Geometry variations were parametrically tested and showed that bare quartz junction supports (76 microns in diameter) yielded superior performance, and were rugged enough to survive considerable impact damage. Using very low cost signal conditioning electronics, temperature accuracies of 0.3 percent were realized yielding turbine efficiency measurements at the 1-percent level. Ongoing work to improve this accuracy is described.

  14. In-situ study of the gas-phase composition and temperature of an intermediate-temperature solid oxide fuel cell anode surface fed by reformate natural gas

    Science.gov (United States)

    Santoni, F.; Silva Mosqueda, D. M.; Pumiglia, D.; Viceconti, E.; Conti, B.; Boigues Muñoz, C.; Bosio, B.; Ulgiati, S.; McPhail, S. J.

    2017-12-01

    An innovative experimental setup is used for in-depth and in-operando characterization of solid oxide fuel cell anodic processes. This work focuses on the heterogeneous reactions taking place on a 121 cm2 anode-supported cell (ASC) running with a H2, CH4, CO2, CO and steam gas mixture as a fuel, using an operating temperature of 923 K. The results have been obtained by analyzing the gas composition and temperature profiles along the anode surface in different conditions: open circuit voltage (OCV) and under two different current densities, 165 mA cm-2 and 330 mA cm-2, corresponding to 27% and 54% of fuel utilization, respectively. The gas composition and temperature analysis results are consistent, allowing to monitor the evolution of the principal chemical and electrochemical reactions along the anode surface. A possible competition between CO2 and H2O in methane internal reforming is shown under OCV condition and low current density values, leading to two different types of methane reforming: Steam Reforming and Dry Reforming. Under a current load of 40 A, the dominance of exothermic reactions leads to a more marked increase of temperature in the portion of the cell close to the inlet revealing that current density is not uniform along the anode surface.

  15. Rotational temperature measurement of NO gas using two-photon excitation spectrum

    Science.gov (United States)

    Ozaki, Tadao; Matsui, Yoshihiko; Ohsawa, Toshihiko

    1981-04-01

    The rotational temperature of nitric oxide gas has been measured by means of a single-beam two-photon excitation spectrum method using a pulsed continuously tunable dye laser. The nitric oxide gas was enclosed at about 40 Torr in a quartz cell which was put in an electric oven. The NO γ (0-0) band and R11+Q21 branches were used to obtain the two-photon excitation spectrum. The rotational temperatures were determined using the fact that molecules are distributed in the rotational levels according to the Boltzmann law. The temperature range was from room temperature to about 470 K. Observed temperatures were in good agreement with cell temperatures which were obtained by using a thermocouple.

  16. Preliminary study on helium turbomachine for high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Chen Yihua; Wang Jie; Zhang Zuoyi

    2003-01-01

    In the high temperature gas-cooled reactor (HTGR), gas turbine cycle is a new concept in the field of nuclear power. It combines two technologies of HTGR and gas turbine cycle, which represent the state-of-the-art technologies of nuclear power and fossil fuel generation respectively. This approach is expected to improve safety and economy of nuclear power plant significantly. So it is a potential scheme with competitiveness. The heat-recuperated cycle is the main stream of gas turbine cycle. In this cycle, the work medium is helium, which is very different from the air, so that the design features of the helium turbomachine and combustion gas turbomachine are different. The paper shows the basic design consideration for the heat-recuperated cycle as well as helium turbomachine and highlights its main design features compared with combustion gas turbomachine

  17. Mean free path of nucleons in a Fermi gas at finite temperature

    International Nuclear Information System (INIS)

    Collins, M.T.; Griffin, J.J.

    1980-01-01

    The mean free path of a nucleon in a nuclear Fermi gas at finite temperature is calculated by utilizing the free nucleon-nucleon cross section modified to suppress final states excluded by the Pauli principle. The results agree with an earlier zero-temperature calculation but yield substantially smaller values than a previous finite-temperature analysis. The Fermi gas mean free paths are some two to four times shorter than those implied by phenomenological imaginary optical potentials, suggesting that the present Fermi gas model fails to adequately describe the physical processes determining the mean free path. Even so, the present results, taken as lower bounds on te mean free path, require temperatures of some 4.5 MeV before the mean free path of bound nucleons becomes as short as the nuclear diameter. It follows that very high excitation energies are prerequisite to any short mean free path assumption in nuclear heavy-ion collisions. (orig.)

  18. Method for determining waveguide temperature for acoustic transceiver used in a gas turbine engine

    Science.gov (United States)

    DeSilva, Upul P.; Claussen, Heiko; Ragunathan, Karthik

    2018-04-17

    A method for determining waveguide temperature for at least one waveguide of a transceiver utilized for generating a temperature map. The transceiver generates an acoustic signal that travels through a measurement space in a hot gas flow path defined by a wall such as in a combustor. The method includes calculating a total time of flight for the acoustic signal and subtracting a waveguide travel time from the total time of flight to obtain a measurement space travel time. A temperature map is calculated based on the measurement space travel time. An estimated wall temperature is obtained from the temperature map. An estimated waveguide temperature is then calculated based on the estimated wall temperature wherein the estimated waveguide temperature is determined without the use of a temperature sensing device.

  19. High-Temperature, High-Bandwidth Fiber Optic Pressure and Temperature Sensors for Gas Turbine Applications

    National Research Council Canada - National Science Library

    Fielder, Robert S; Palmer, Matthew E

    2003-01-01

    ..., and redesign compressor and turbine stages based on actual measurements. There currently exists no sensor technology capable of making pressure measurements in the critical hot regions of gas turbine engines...

  20. Combustion Temperature Effect of Diesel Engine Convert to Compressed Natural Gas Engine

    OpenAIRE

    Semin; Abdul R. Ismail; Rosli A. Bakar

    2009-01-01

    Effect of combustion temperature in the engine cylinder of diesel engine convert to Compressed Natural Gas (CNG) engine was presents in this study. The objective of this study was to investigate the engine cylinder combustion temperature effect of diesel engine convert to CNG engine on variation engine speed. Problem statement: The hypothesis was that the lower performance of CNG engine was caused by the effect of lower in engine cylinder temperature. Are the CNG engine is lower cylinder temp...

  1. High Temperature Metallic Seal Development For Aero Propulsion and Gas Turbine Applications

    Science.gov (United States)

    More, Greg; Datta, Amit

    2006-01-01

    A viewgraph presentation on metallic high temperature static seal development at NASA for gas turbine applications is shown. The topics include: 1) High Temperature Static Seal Development; 2) Program Review; 3) Phase IV Innovative Seal with Blade Alloy Spring; 4) Spring Design; 5) Phase IV: Innovative Seal with Blade Alloy Spring; 6) PHase IV: Testing Results; 7) Seal Seating Load; 8) Spring Seal Manufacturing; and 9) Other Applications for HIgh Temperature Spring Design

  2. [Investigation on the gas temperature of a plasma jet at atmospheric pressure by emission spectrum].

    Science.gov (United States)

    Li, Xue-chen; Yuan, Ning; Jia, Peng-ying; Niu, Dong-ying

    2010-11-01

    A plasma jet of a dielectric barrier discharge in coaxial electrode was used to produce plasma plume in atmospheric pressure argon. Spatially and temporally resolved measurement was carried out by photomultiplier tubes. The light emission signals both from the dielectric barrier discharge and from the plasma plume were analyzed. Furthermore, emission spectrum from the plasma plume was collected by high-resolution optical spectrometer. The emission spectra of OH (A 2sigma + --> X2 II, 307.7-308.9 nm) and the first negative band of N2+ (B2 sigma u+ --> X2 IIg+, 390-391.6 nm) were used to estimate the rotational temperature of the plasma plume by fitting the experimental spectra to the simulated spectra. The rotational temperature obtained is about 443 K by fitting the emission spectrum from the OH, and that from the first negative band of N2+ is about 450 K. The rotational temperatures obtained by the two method are consistent within 5% error band. The gas temperature of the plasma plume at atmospheric pressure was obtained because rotational temperature equals to gas temperature approximately in gas discharge at atmospheric pressure. Results show that gas temperature increases with increasing the applied voltage.

  3. Correlator of nucleon currents in finite temperature pion gas

    International Nuclear Information System (INIS)

    Eletsky, V.L.

    1990-01-01

    A retarded correlator of two currents with nucleon quantum numbers is calculated for finite temperature T π in the chiral limit. It is shown that for euclidean momenta the leading one-loop corrections arise from direct interaction of thermal pions with the currents. A dispersive representation for the correlator shows that this interaction smears the nucleon pole over a frequency interval with width ≅ T. This interaction does not change the exponential fall-off of the correlator in euclidean space but gives an O(T 2 /F 2 π ) contribution to the pre-exponential factor. (orig.)

  4. Anomalous low-temperature desorption from preirradiated rare gas solids

    International Nuclear Information System (INIS)

    Savchenko, E.V.; Gumenchuk, G.B.; Yurtaeva, E.M.; Belov, A.G.; Khyzhniy, I.V.; Frankowski, M.; Beyer, M.K.; Smith-Gicklhorn, A.M.; Ponomaryov, A.N.; Bondybey, V.E.

    2005-01-01

    The role for the exciton-induced defects in the stimulation of anomalous low-temperature desorption of the own lattice atoms from solid Ar and Ne preirradiated by an electron beam is studied. The free electrons from shallow traps-structural defects-was monitored by the measurements of a yield of the thermally induced exoelectron emission (TSEE). The reaction of recombination of self-trapped holes with electrons is considered as a source of energy needed for the desorption of atoms from the surface of preirradiated solids. A key part of the exciton-induced defects in the phenomenon observed is demonstrated

  5. Effect of changes in seafloor temperature and sea-level on gas hydrate stability

    Energy Technology Data Exchange (ETDEWEB)

    Garg, S.K.; Pritchett, W. [Science Applications International Corp., San Diego, CA (United States)

    2008-07-01

    Natural gas hydrates occur in oceanic sediments and in permafrost regions around the world. As a greenhouse gas, large amounts of methane released from the global hydrate reservoir would have a significant impact on Earth's climate. The role of methane released by hydrate dissociation in climate change is uncertain. However, changes in global climate such as glaciation and warming can destabilize the hydrates. During the last glacial maximum, the sea level dropped about 100 meters. It has been suggested that the sea-level fall was associated with gas hydrate instability and seafloor slumping. This paper investigated the effect of changes in seafloor temperature and sea level on gas hydrate stability and on gas venting at the seafloor. A one-dimensional numerical computer model (simulator) was developed to describe methane hydrate formation, decomposition, reformation, and distribution with depth below the seafloor in the marine environment. The simulator was utilized to model hydrate distributions at two sites, notably Blake Ridge, located offshore South Carolina and Hydrate Ridge, located off the coast of Oregon. The numerical models for the two sites were conditioned by matching the sulfate, chlorinity, and hydrate distribution measurements. The effect of changes in seafloor temperature and sea-level on gas hydrate stability were then investigated. It was concluded that for Blake Ridge, changes in hydrate concentration were small. Both the changes in seafloor temperature and sea-level led to a substantial increase in gas venting at the seafloor for Hydrate Ridge. 17 refs., 8 figs.

  6. Numerical simulation and geometry optimization of hot-gas mixing in lower plenum of high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Wang Hang; Wang Jie; Laurien, E.

    2010-01-01

    The lower plenum in high temperature gas-cooled reactor was designed to mix the gas of different temperatures from the reactor core. Previous researches suggest the current geometry of the lower plenum to be improved for better mixing capability and lower pressure drop. In the presented work, a series of varied geometries were investigated with numerical simulation way. The choice of appropriate mesh type and size used in the geometry variation was discussed with the reference of experimental data. The original thin ribs in the current design were merged into thicker ones, and a junction located at the starting end of the outlet pipe was introduced. After comparing several potential optimization methods, an improved geometry was selected with the merged ribs increasing the pre-defined mixing coefficient and the junction reducing the pressure drop. Future work was discussed based on the simulation of real reactor case. The work shows a direction for design improvements of the lower plenum geometry. (authors)

  7. High-temperature gas-cooled reactor: reformer application study

    International Nuclear Information System (INIS)

    1980-12-01

    This Application Study evaluates the HTGR-R with a core outlet temperature of 850 0 C as a near-term Lead Project and as a vehicle to long-term HTGR Program objectives. The scope of this effort included evaluation of the HTGR-R technology, evaluation of potential HTGR-R markets, assessment of the economics of commercial HTGR-R plants, and the evaluation of the program scope and expenditures necessary to establish HTGR-R technology through the completion of the Lead Project. In order to properly assess the potential of the HTGR-R and the suitability of the HTGR-R as a Lead Project, additional work must be performed before a final judgment is rendered. Design trade-off studies and alternative applications must be investigated to determine if a commercial potential exists for the HTGR-R at 850 0 C. If commercial incentives are only identified for the HTGR-R with core outlet temperatures greater than 850 0 C, the design and development program duration and cost and the demonstration path for the HTGR-R must be reassessed

  8. Gas cooled thermal reactors with high temperatures (VHTR)

    International Nuclear Information System (INIS)

    Bouchter, J.C.; Dufour, P.; Guidez, J.; Latge, C.; Renault, C.; Rimpault, G.; Vasile, A.

    2014-01-01

    VHTR is one of the 6 concepts retained for the 4. generation of nuclear reactors, it is an upgraded version of the HTR-type reactor (High Temperature Reactors). 5 HTR reactors were operated in the world in the eighties, now 2 experimental HTR are working in China and Japan and 2 HTR with an output power of 100 MWe are being built in China. The purpose of the VHTR is to provide an helium at very high temperatures around 1000 Celsius degrees that could be used directly in a thermochemical way to produce hydrogen for instance. HTR reactors are interesting in terms of safety but it does not optimise the consumption of uranium and the production of wastes. This article presents a brief historical account of HTR-type reactors and their main design and safety features. The possibility of using HTR to burn plutonium is also presented as well as the possibility of closing the fuel cycle and of using thorium-uranium fuel. (A.C.)

  9. Stability of test environments for performance evaluation of materials for the modular high-temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Edgemon, G.L.; Wilson, D.F.; Bell, G.E.C.

    1993-01-01

    Stability of the primary helium-based coolant test gas for use in performance ests of materials for the Modular High-Temperature Gas-Cooled Reactor (MHTGR) was determined. Results of tests of the initial gas chemistry from General Atomics (GA) at elevated temperatures, and the associated results predicted by the SOLGASMIX trademark modelling package are presented. Results indicated that for this gas composition and at flow rates obtainable in the test loop, 466 ± 24C is the highest temperature that can be maintained without significantly altering the specified gas chemistry. Four additional gas chemistries were modelled using SOLGASMIX trademark

  10. Gas-liquid interface of room-temperature ionic liquids.

    Science.gov (United States)

    Santos, Cherry S; Baldelli, Steven

    2010-06-01

    The organization of ions at the interface of ionic liquids and the vacuum is an ideal system to test new ideas and concepts on the interfacial chemistry of electrolyte systems in the limit of no solvent medium. Whilst electrolyte systems have numerous theoretical and experimental methods used to investigate their properties, the ionic liquids are relatively new and our understanding of the interfacial properties is just beginning to be explored. In this critical review, the gas-liquid interface is reviewed, as this interface does not depend on the preparation of another medium and thus produces a natural interface. The interface has been investigated by sum frequency generation vibrational spectroscopy and ultra-high vacuum techniques. The results provide a detailed molecular-level view of the surface composition and structure. These have been complemented by theoretical studies. The combinations of treatments on this interface are starting to provide a somewhat convergent description of how the ions are organized at this neat interface (108 references).

  11. Enhancing aquifer cleanup with reinjection

    International Nuclear Information System (INIS)

    Isherwood, W.F.; Ziagos, J.; Rice, D. Jr.; Krauter, P.; Nichols, E.

    1992-09-01

    Injection of water or steam, with or without chemical surfactants, is a common petroleum industry technique to enhance product recovery. In the geothermal industry, reinjection (reinjection is used to mean the injection of ground water that was previously injected) of heat- depleted subsurface fluids is commonly used to maintain reservoir pressure, thus prolonging field productivity. The use reinjection in ground-water remediation projects allows for the application of both traditional production field management and a variety of additional enhancements to the cleanup process. Development of the ideas in this paper was stimulated by an initial suggestion by Dr. Jacob Bear (personal discussions, 1990--1991) that reinjected water might be heated to aid the desorption process

  12. Mechanical Property and Its Comparison of Superalloys for High Temperature Gas Cooled Reactor

    International Nuclear Information System (INIS)

    Kim, Woo Gon; Kim, D. W.; Ryu, W. S.; Han, C. H.; Yoon, J. H.; Chang, J.

    2005-01-01

    Since structural materials for high temperature gas cooled reactor are used during long period in nuclear environment up to 1000 .deg. C, it is important to have good properties at elevated temperature such as mechanical properties (tensile, creep, fatigue, creep-fatigue), microstructural stability, interaction between metal and gas, friction and wear, hydrogen and tritium permeation, irradiation behavior, corrosion by impurity in He. Thus, in order to select excellent materials for the high temperature gas cooled reactor, it is necessary to understand the material properties and to gather the data for them. In this report, the items related to material properties which are needed for designing the high temperature gas cooled reactor were presented. Mechanical properties; tensile, creep, and fatigue etc. were investigated for Haynes 230, Hastelloy-X, In 617 and Alloy 800H, which can be used as the major structural components, such as intermediate heat exchanger (IHX), hot duct and piping and internals. Effect of He and irradiation on these structural materials was investigated. Also, mechanical properties; physical properties, tensile properties, creep and creep crack growth rate were compared for them, respectively. These results of this report can be used as important data to select superior materials for high temperature gas reactor

  13. The Validity of 21 cm Spin Temperature as a Kinetic Temperature Indicator in Atomic and Molecular Gas

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, Gargi [Dept. of Physics, UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai, Mumbai 400098 (India); Ferland, G. J. [Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States); Hubeny, I., E-mail: gargishaw@gmail.com, E-mail: gary@uky.edu, E-mail: hubeny@as.arizona.edu [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States)

    2017-07-10

    The gas kinetic temperature ( T {sub K} ) of various interstellar environments is often inferred from observations that can deduce level populations of atoms, ions, or molecules using spectral line observations; H i 21 cm is perhaps the most widely used, and has a long history. Usually the H i 21 cm line is assumed to be in thermal equilibrium and the populations are given by the Boltzmann distribution. A variety of processes, many involving Ly α , can affect the 21 cm line. Here we show how this is treated in the spectral simulation code Cloudy, and present numerical simulations of environments where this temperature indicator is used, with a detailed treatment of the physical processes that determine level populations within H{sup 0}. We discuss situations where this temperature indicator traces T {sub K}, cases where it fails, as well as the effects of Ly α pumping on the 21 cm spin temperature. We also show that the Ly α excitation temperature rarely traces the gas kinetic temperature.

  14. HANFORD SITE RIVER CORRIDOR CLEANUP

    International Nuclear Information System (INIS)

    BAZZELL, K.D.

    2006-01-01

    In 2005, the US Department of Energy (DOE) launched the third generation of closure contracts, including the River Corridor Closure (RCC) Contract at Hanford. Over the past decade, significant progress has been made on cleaning up the river shore that bordes Hanford. However, the most important cleanup challenges lie ahead. In March 2005, DOE awarded the Hanford River Corridor Closure Contract to Washington Closure Hanford (WCH), a limited liability company owned by Washington Group International, Bechtel National and CH2M HILL. It is a single-purpose company whose goal is to safely and efficiently accelerate cleanup in the 544 km 2 Hanford river corridor and reduce or eliminate future obligations to DOE for maintaining long-term stewardship over the site. The RCC Contract is a cost-plus-incentive-fee closure contract, which incentivizes the contractor to reduce cost and accelerate the schedule. At $1.9 billion and seven years, WCH has accelerated cleaning up Hanford's river corridor significantly compared to the $3.2 billion and 10 years originally estimated by the US Army Corps of Engineers. Predictable funding is one of the key features of the new contract, with funding set by contract at $183 million in fiscal year (FY) 2006 and peaking at $387 million in FY2012. Another feature of the contract allows for Washington Closure to perform up to 40% of the value of the contract and subcontract the balance. One of the major challenges in the next few years will be to identify and qualify sufficient subcontractors to meet the goal

  15. Decrease in lower level density due to cooling of gas temperature by thermal dissociation of hydrogen in copper vapor laser

    International Nuclear Information System (INIS)

    Watanabe, Ikuo; Hayashi, Kazuo; Iseki, Yasushi; Suzuki, Setsuo; Noda, Etsuo; Morimiya, Osamu

    1995-01-01

    A gas temperature calculation is carried out in the copper vapor laser (CVL) with a beam diameter of 80 mm in the case of H 2 addition into the Ne buffer gas. The on-axis gas temperature decreases to 2800K with 1% concentration of H 2 , whereas the gas temperature is 3400K without H 2 . The on-axis lower level density decreases due to the cooling of the gas temperature. This decrease in the lower level density is thought to bring about a non annular beam profile in the case of H 2 addition. (author)

  16. Corrosion of high temperature alloys in the primary circuit helium of high temperature gas cooled reactors. Pt. 2

    International Nuclear Information System (INIS)

    Quadakkers, W.J.

    1985-01-01

    The reactive impurities H 2 O, CO, H 2 and CH 4 which are present in the primary coolant helium of high temperature gas-cooled reactors can cause scale formation, internal oxidation and carburization or decarburization of the high temperature structural alloys. In Part 1 of this contribution a theoretical model was presented, which allows the explanation and prediction of the observed corrosion effects. The model is based on a classical stability diagram for chromium, modified to account for deviations from equilibrium conditions caused by kinetic factors. In this paper it is shown how a stability diagram for a commercial alloy can be constructed and how this can be used to correlate the corrosion results with the main experimental parameters, temperature, gas and alloy composition. Using the theoretical model and the presented experimental results, conditions are derived under which a protective chromia based surface scale will be formed which prevents a rapid transfer of carbon between alloy and gas atmosphere. It is shown that this protective surface oxide can only be formed if the carbon monoxide pressure in the gas exceeds a critical value. Psub(CO), which depends on temperature and alloy composition. Additions of methane only have a limited effect provided that the methane/water ratio is not near to, or greater than, a critical value of around 100/1. The influence of minor alloying additions of strong oxide forming elements, commonly present in high temperature alloys, on the protective properties of the chromia surface scales and the kinetics of carbon transfer is illustrated. (orig.) [de

  17. Dynamic analysis of the CRBRP clean-up system (three stage aqueous scrubber)

    International Nuclear Information System (INIS)

    Kyi, R.; Bijlani, C.; Fazekas, P.; Dajani, A.

    1981-01-01

    The CRBRP containment clean-up system design required the determination of the thermal-hydraulic performance of the system during its projected operating cycle. The reduced scale component tests at HEDL provided valuable information about the generic performance of the components; however, due to the limitations of the test facility the exact simulation of the actual CRBRP conditions was not feasible. A computer program was developed to permit dynamic system analysis of the full size air cleaning system. The dynamic system analysis considered the mass and energy balances across each component. In addition to the major filtration system components, the system modeling included the supporting fluid system components such as pumps, tanks and heat exchangers. Variable gas flow, temperature, chemical concentrations, and other system parameters were also modeled. Fission product heat, chemical reaction heat and heat of solution were considered. The analysis results provided sodium hydroxide solution concentrations and temperatures, gas temperatures and other variables at the various components within the air cleaning system for each calculated time interval. The accuracy of the computer modeling was verified by comparing the calculated results with HEDL test data. The comparison indicated a better than +-10% agreement with the test data. The analysis results provided the basis for the selection of the system components

  18. Improved spacers for high temperature gas-cooled heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Nordstroem, L A [Swiss Federal Institute for Reactor Research, Wuerenlingen (Switzerland)

    1984-07-01

    Experimental and analytical investigations in the field of heat exchanger thermohydraulics have been performed at EIR for many years, Basic studies have been carried out on heat transfer and pressure loss for tube bundles of different geometries and tube surfaces. As a part of this overall R+D programme for heat exchangers, investigations have been carried out on spacer pressure loss in bundles with longitudinal flow. An analytical spacer pressure loss model was developed which could handle different types of subchannel within the bundle. The model has been evaluated against experiments, using about 25 spacers of widely differing geometries. In a gas-cooled reactor it is important to keep the pressure loss over the primary circuit heat exchangers to a minimum. In exchangers with grid spacers these contribute a significant proportion of the overall bundle losses. For example, in the HHT Recuperator, with a shell-side pressure loss of 3.5 % of the inlet pressure, the spacers cause about one half of this loss. Reducing the loss to, say, 2.5 % results in an overall increase in plant efficiency by more than 1 % - a significant improvement Preliminary analysis identified 5 geometries in particular which were chosen for experimental evaluation as part of a joint project with the SULZER Company, to develop a low pressure-loss spacer for HHT heat exchangers (longitudinal counter-flow He/He and He/H{sub 2}O designs). The aim of the tests was to verify the low pressure-loss characteristics of these spacer grid types, as well as the quality of the results calculated by the computer code analytical model. The experimental and analytical results are compared in this report.

  19. Exploitation of low-temperature energy sources from cogeneration gas engines

    International Nuclear Information System (INIS)

    Caf, A.; Urbancl, D.; Trop, P.; Goricanec, D.

    2016-01-01

    This paper describes an original and innovative technical solution for exploiting low-temperature energy sources from cogeneration gas reciprocating engines installed within district heating systems. This solution is suitable for those systems in which the heat is generated by the use of reciprocating engines powered by gaseous fuel for combined heat and power production. This new technical solution utilizes low-temperature energy sources from a reciprocating gas engine which is used for a combined production of heat and power. During the operation of the cogeneration system low-temperature heat is released, which can be raised to as much as 85 °C with the use of a high-temperature heat-pump, thus enabling a high-temperature regime for heating commercial buildings, district heating or in industrial processes. In order to demonstrate the efficiency of utilizing low-temperature heat sources in the cogeneration system, an economic calculation is included which proves the effectiveness and rationality of integrating high-temperature heat-pumps into new or existing systems for combined heat and power production with reciprocating gas engines. - Highlights: • The use of low-temperature waste heat from the CHP is described. • Total energy efficiency of the CHP can be increased to more than 103.3%. • Low-temperature heat is exploited with high-temperature heat pump. • High-temperature heat pump allows temperature rise to up to 85 °C. • Exploitation of low-temperature waste heat increases the economics of the CHP.

  20. The world trends of high temperature gas-cooled reactors and the mode of utilization

    International Nuclear Information System (INIS)

    Ishikawa, Hiroshi; Shimokawa, Jun-ichi

    1974-01-01

    After a long period of research and development, high temperature gas-cooled reactors are going to enter the practical stage. The combination of a HTGR with a closed cycle helium gas turbine is advantageous in thermal efficiency, reduction of environmental impact and economy. In recent years, the direct utilization of nuclear heat energy in industries has been attracting interest. The multi-purpose utilization of high temperature gas-cooled reactors is thus now the world trend. Reviewing the world developments in this field, the following matters are described: (1) development of HTGRs in the U.K., West Germany, France and the United States; (2) development of He gas turbine, etc. in West Germany; and (3) multi-purpose utilization of HTGRs in West Germany and Japan. (Mori, K.)

  1. A Comparison of Thermal Models for Temperature Profiles in Gas-Lift Wells

    Directory of Open Access Journals (Sweden)

    Langfeng Mu

    2018-02-01

    Full Text Available Gas lift is a simple, reliable artificial lift method which is frequently used in offshore oil field developments. In order to enhance the efficiency of production by gas lift, it is vital to exactly predict the distribution of temperature-field for fluid within the wellbore. A new mechanistic model is developed for computing flowing fluid temperature profiles in both conduits simultaneously for a continuous-flow gas-lift operation. This model assumes steady heat transfer in the formation, as well as steady heat transfer in the conduits. A micro-units discrete from the wellbore, whose heat transfer process is analyzed and whose heat transfer equation is set up according to the law of conservation of energy. A simplified algebraic solution to our model is conducted to analyze the temperature profile. Sensitivity analysis was conducted with the new model. The results indicate that mass flow rate of oil and the tubing overall heat transfer coefficient are the main factors that influence the temperature distribution inside the tubing and that the mass flow rate of oil is the main factor affecting temperature distribution in the annulus. Finally, the new model was tested in three various wells and compared with other models. The results showed that the new model is more accurate and provides significant references for temperature prediction in gas lift well.

  2. Development and industrial application of catalyzer for low-temperature hydrogenation hydrolysis of Claus tail gas

    Directory of Open Access Journals (Sweden)

    Honggang Chang

    2015-10-01

    Full Text Available With the implementation of more strict national environmental protection laws, energy conservation, emission reduction and clean production will present higher requirements for sulfur recovery tail gas processing techniques and catalyzers. As for Claus tail gas, conventional hydrogenation catalyzers are gradually being replaced by low-temperature hydrogenation catalyzers. This paper concentrates on the development of technologies for low-temperature hydrogenation hydrolysis catalyzers, preparation of such catalyzers and their industrial application. In view of the specific features of SO2 hydrogenation and organic sulfur hydrolysis during low-temperature hydrogenation, a new technical process involving joint application of hydrogenation catalyzers and hydrolysis catalyzers was proposed. In addition, low-temperature hydrogenation catalyzers and low-temperature hydrolysis catalyzers suitable for low-temperature conditions were developed. Joint application of these two kinds of catalyzers may reduce the inlet temperatures in the conventional hydrogenation reactors from 280 °C to 220 °C, at the same time, hydrogenation conversion rates of SO2 can be enhanced to over 99%. To further accelerate the hydrolysis rate of organic sulfur, the catalyzers for hydrolysis of low-temperature organic sulfur were developed. In lab tests, the volume ratio of the total sulfur content in tail gas can be as low as 131 × 10−6 when these two kinds of catalyzers were used in a proportion of 5:5 in volumes. Industrial application of these catalyzers was implemented in 17 sulfur recovery tail gas processing facilities of 15 companies. As a result, Sinopec Jinling Petrochemical Company had outstanding application performances with a tail gas discharging rate lower than 77.9 mg/m3 and a total sulfur recovery of 99.97%.

  3. High temperature gasification and gas cleaning – phase II of the HotVegas project

    OpenAIRE

    Meysel, P.; Halama, S.; Botteghi, F.; Steibel, M.; Nakonz, M.; Rück, R.; Kurowski, P.; Buttler, A.; Spliethoff, H.

    2016-01-01

    The primary objective of the research project HotVeGas is to lay the necessary foundations for the long-term development of future, highly efficient high-temperature gasification processes. This includes integrated hot gas cleaning and optional CO2 capture and storage for next generation IGCC power plants and processes for the development of synthetic fuels. The joint research project is funded by the German Federal Ministry of Economics and Technology and five industry partners. It is coordi...

  4. Ambient temperature effects on gas turbine power plant: A case study in Iran

    International Nuclear Information System (INIS)

    Gorji, M.; Fouladi, F.

    2007-01-01

    Actual thermal efficiency, electric-power output, fuel-air ratio and specific fuel consumption (SFC) vary according to the ambient conditions. The amount of these variations greatly affects those parameters as well as the plant incomes. In this paper the effect of ambient temperature as a seasonal variation on a gas power plant has been numerically studied. For this purpose, the gas turbine model and different climate seasonal variations of Ray in Iran are considered in this study. For the model, by using average monthly temperature data of the region, the different effective parameters were compared to those in standard design conditions. The results show that ambient temperature increase will decrease thermal efficiency, electric-power out put and fuel-air ratio of the gas turbine plant whereas increases the specific fuel consumption

  5. Thermal Stress FE Analysis of Large-scale Gas Holder Under Sunshine Temperature Field

    Science.gov (United States)

    Li, Jingyu; Yang, Ranxia; Wang, Hehui

    2018-03-01

    The temperature field and thermal stress of Man type gas holder is simulated by using the theory of sunshine temperature field based on ASHRAE clear-sky model and the finite element method. The distribution of surface temperature and thermal stress of gas holder under the given sunshine condition is obtained. The results show that the thermal stress caused by sunshine can be identified as one of the important factors for the failure of local cracked oil leakage which happens on the sunny side before on the shady side. Therefore, it is of great importance to consider the sunshine thermal load in the stress analysis, design and operation of large-scale steel structures such as the gas holder.

  6. The internal energy and thermodynamic behaviour of a boson gas below the Bose-Einstein temperature

    International Nuclear Information System (INIS)

    Deeney, F.A.; O'Leary, J.P.

    2011-01-01

    We have examined the issue of the kinetic energy of particles in the ground state of an ideal boson gas. By assuming that the particles, on dropping into the ground state, retain the kinetic energy they possess at the Bose-Einstein temperature T B , we obtain new expressions for the pressure and internal energy of the gas below T B , that are free of the difficulties associated with the corresponding expressions in current theory. Furthermore, these new equations yield a value for the maximum density temperature in liquid 4 He that is very close to the measured value. - Highlights: → A new equation of state for an ideal boson gas that is anomaly-free. → A prediction of the existence of a density maximum in all ideal boson gases. → Calculation of the temperature at which a density maximum will occur in liquid 4 He.

  7. High temperature and high pressure gas cell for quantitative spectroscopic measurements

    International Nuclear Information System (INIS)

    Christiansen, Caspar; Stolberg-Rohr, Thomine; Fateev, Alexander; Clausen, Sønnik

    2016-01-01

    A high temperature and high pressure gas cell (HTPGC) has been manufactured for quantitative spectroscopic measurements in the pressure range 1–200 bar and temperature range 300–1300 K. In the present work the cell was employed at up to 100 bar and 1000 K, and measured absorption coefficients of a CO_2–N_2 mixture at 100 bar and 1000 K are revealed for the first time, exceeding the high temperature and pressure combinations previously reported. This paper discusses the design considerations involved in the construction of the cell and presents validation measurements compared against simulated spectra, as well as published experimental data. - Highlights: • A ceramic gas cell designed for gas measurements up to 1300 K and 200 bar. • The first recorded absorption spectrum of CO_2 at 1000 K and 101 bar is presented. • Voigt profiles might suffice in the modeling of radiation from CO_2 in combustion.

  8. High temperature metallic materials for gas-cooled reactors

    International Nuclear Information System (INIS)

    1989-06-01

    The Specialists' Meeting was organized in conjunction with an earlier meeting on this topic held in Vienna, Austria, 1981, which provided for a comprehensive review of the status of materials development and testing at that time and for a description of test facilities. This meeting provided an opportunity (1) to review and discuss the progress made since 1981 in the development, testing and qualification of high temperature metallic materials, (2) to critically assess results achieved, and (3) to give directions for future research and development programmes. In particular, the meeting provided a form for a close interaction between component designers and materials specialists. The meeting was attended by 48 participants from France, People's Republic of China, Federal Republic of Germany, Japan, Poland, Switzerland, United Kingdom, USSR and USA presenting 22 papers. The technical part of the meeting was subdivided into four technical sessions: Components Design and Testing - Implications for Materials (4 papers); Microstructure and Environmental Compatibility (4 papers); Mechanical Properties (9 papers); New Alloys and Developments (6 papers). At the end of the meeting a round table discussion was organized in order to summarize the meeting and to make recommendations for future activities. This volume contains all papers presented at the meeting. A separate abstract was prepared for each of these papers. Refs, figs and tabs

  9. Design and development of gas turbine high temperature reactor 300 (GTHTR300)

    International Nuclear Information System (INIS)

    Kunitomi, Kazuhiko; Katanishi, Shoji; Takada, Shoji; Takizuka, Takakazu; Yan, Xing; Kosugiyama, Shinichi

    2003-01-01

    JAERI (Japan Atomic Energy Research Institute) started design and development of the high temperature gas cooled reactor with a gas turbine electric generation system, GTHTR300, in April 2001. Design originalities of the GTHTR300 are a horizontally mounted highly efficient gas turbine system and an ultimately simplified safety system such as no containment building and no active emergency core cooling. These design originalities are proposed based on design and operational experiences in conventional gas turbine systems and Japan's first high temperature gas cooled reactor (HTTR: High Temperature Engineering Test Reactor) so that many R and Ds are not required for the development. Except these original design features, devised core design, fuel design and plant design are adopted to meet design requirements and attain a target cost. This paper describes the unique design features focusing on the safety design, reactor core design and gas turbine system design together with a preliminary result of the safety evaluation carried out for a typical severe event. This study is entrusted from Ministry of Education, Culture, Sports, Science and Technology of Japan. (author)

  10. Reduction and Analysis of Low Temperature Shift Heterogeneous Catalyst for Water Gas Reaction in Ammonia Production

    Directory of Open Access Journals (Sweden)

    Zečević, N.

    2013-09-01

    Full Text Available In order to obtain additional quantities of hydrogen after the reforming reactions of natural gas and protect the ammonia synthesis catalyst, it is crucial to achieve and maintain maximum possible activity, selectivity and stability of the low temperature shift catalyst for conversion of water gas reaction during its lifetime. Whereas the heterogeneous catalyst comes in oxidized form, it is of the utmost importance to conduct the reduction procedure properly. The proper reduction procedure and continuous analysis of its performance would ensure the required activity, selectivity and stability throughout the catalyst’s service time. For the proper reduction procedure ofthe low temperature shift catalyst, in addition to process equipment, also necessary is a reliable and realistic system for temperature measurements, which will be effective for monitoring the exothermal temperature curves through all catalyst bed layers. For efficiency evaluation of low shift temperature catalyst reduction and its optimization, it is necessary to determine at regular time intervals the temperature approach to equilibrium and temperature profiles of individual layers by means of "S" and "die off" temperature exothermal curves. Based on the obtained data, the optimum inlet temperature could be determined, in order to maximally extend the service life of the heterogeneous catalyst as much as possible, and achieve the optimum equilibrium for conversion of the water gas. This paper presents the methodology for in situ reduction of the low temperature shift heterogeneous catalyst and the developed system for monitoring its individual layers to achieve the minimum possible content of carbon monoxide at the exit of the reactor. The developed system for temperature monitoring through heterogeneous catalyst layers provides the proper procedure for reduction and adjustment of optimum process working conditions for the catalyst by the continuous increase of reactor inlet

  11. Combination scattering of dissociating gas applied to measurements of temperature and concentration of components

    International Nuclear Information System (INIS)

    Pashkov, V.A.; Kurganova, F.I.; Grishchuk, M.Kh.

    1987-01-01

    The method to calculate the combination scattering power of the components of the dissociating N 2 O 4 ↔ 2NO 2 → 2NO+O 2 gas subjected to the laser radiation effect is given. The combination scattering power has been calculated for temperatures 400-600 K, pressures 1-3 MPa, with the neodymium laser (λ=1.06 μm) as a source and the possibility of measuring the local temperatures and concentration of the given gas components with the help of the combination scattering has been analysed. It follows from the calculated data that combination scattering power of N 2 O 4 ↔ 2NO 2 ↔ 2NO+O 2 gas in excitation with the neodymium laser as a source is sufficient for detection. Gas temperature is likely to be measured with the minimum error relative to stokes and anti-stokes bands of the combination scattering, produced by nitrogen tetroxide. From calculated data it also follows that measurement of NO 2 concentration in the range 400-600 K is possible. At the same time combination scattering power, produced by NO and O 2 components is sufficient for measurement merely with the concentration of the components of the order of 10 18 molecules/cm 3 guaranteed in static conditions only at N 2 O 4 ↔ 2NO 2 ↔ 2NO+O 2 gas temperature 500 K and higher

  12. Inspired gas humidity and temperature during mechanical ventilation with the Stephanie ventilator.

    Science.gov (United States)

    Preo, Bianca L; Shadbolt, Bruce; Todd, David A

    2013-11-01

    To measure inspired gas humidity and temperature delivered by a Stephanie neonatal ventilator with variations in (i) circuit length; (ii) circuit insulation; (iii) proximal airway temperature probe (pATP) position; (iv) inspiratory temperature (offset); and (v) incubator temperatures. Using the Stephanie neonatal ventilator, inspired gas humidity and temperature were measured during mechanical ventilation at the distal inspiratory limb and 3 cm down the endotracheal tube. Measurements were made with a long or short circuit; with or without insulation of the inspiratory limb; proximal ATP (pATP) either within or external to the incubator; at two different inspiratory temperature (offset) of 37(-0.5) and 39(-2.0)°C; and at three different incubator temperatures of 32, 34.5, and 37°C. Long circuits produced significantly higher inspired humidity than short circuits at all incubator settings, while only at 32°C was the inspired temperature higher. In the long circuits, insulation further improved the inspired humidity especially at 39(-2.0)°C, while only at incubator temperatures of 32 and 37°C did insulation significantly improve inspired temperature. Positioning the pATP outside the incubator did not result in higher inspired humidity but did significantly improve inspired temperature. An inspiratory temperature (offset) of 39(-2.0)°C delivered significantly higher inspired humidity and temperature than the 37(-0.5)°C especially when insulated. Long insulated Stephanie circuits should be used for neonatal ventilation when the infant is nursed in an incubator. The recommended inspiratory temperature (offset) of 37(-0.5)°C produced inspired humidity and temperature below international standards, and we suggest an increase to 39(-2.0)°C. © 2013 John Wiley & Sons Ltd.

  13. Large-Scale Wireless Temperature Monitoring System for Liquefied Petroleum Gas Storage Tanks

    Directory of Open Access Journals (Sweden)

    Guangwen Fan

    2015-09-01

    Full Text Available Temperature distribution is a critical indicator of the health condition for Liquefied Petroleum Gas (LPG storage tanks. In this paper, we present a large-scale wireless temperature monitoring system to evaluate the safety of LPG storage tanks. The system includes wireless sensors networks, high temperature fiber-optic sensors, and monitoring software. Finally, a case study on real-world LPG storage tanks proves the feasibility of the system. The unique features of wireless transmission, automatic data acquisition and management, local and remote access make the developed system a good alternative for temperature monitoring of LPG storage tanks in practical applications.

  14. Large-Scale Wireless Temperature Monitoring System for Liquefied Petroleum Gas Storage Tanks.

    Science.gov (United States)

    Fan, Guangwen; Shen, Yu; Hao, Xiaowei; Yuan, Zongming; Zhou, Zhi

    2015-09-18

    Temperature distribution is a critical indicator of the health condition for Liquefied Petroleum Gas (LPG) storage tanks. In this paper, we present a large-scale wireless temperature monitoring system to evaluate the safety of LPG storage tanks. The system includes wireless sensors networks, high temperature fiber-optic sensors, and monitoring software. Finally, a case study on real-world LPG storage tanks proves the feasibility of the system. The unique features of wireless transmission, automatic data acquisition and management, local and remote access make the developed system a good alternative for temperature monitoring of LPG storage tanks in practical applications.

  15. Refinements to temperature calculations of spent fuel assemblies when in a stagnant gas environment

    International Nuclear Information System (INIS)

    Rhodes, C.A.; Haire, M.J.

    1984-01-01

    Undesirably high temperatures are possible in irradiated fuel assemblies because of the radioactive decay of fission products formed while in the reactor. The COXPRO computer code has been used for some time to calculate temperatures in spent fuel when the fuel is suspended in a stagnant gas environment. This code assumed radiation to be the only mode of heat dissipation within the fuel pin bundle. Refinements have been made to include conduction as well as radiation heat transfer within this code. Comparison of calculated and measured temperatures in four separate and independent tests indicate that maximum fuel assembly temperatures can be predicted to within about 6%. 2 references, 5 figures

  16. The finite-temperature thermodynamics of a trapped unitary Fermi gas within fractional exclusion statistics

    International Nuclear Information System (INIS)

    Qin Fang; Chen Jisheng

    2010-01-01

    We utilize the fractional exclusion statistics of the Haldane and Wu hypothesis to study the thermodynamics of a unitary Fermi gas trapped in a harmonic oscillator potential at ultra-low finite temperature. The entropy per particle as a function of the energy per particle and energy per particle versus rescaled temperature are numerically compared with the experimental data. The study shows that, except the chemical potential behaviour, there exists a reasonable consistency between the experimental measurement and theoretical attempt for the entropy and energy per particle. In the fractional exclusion statistics formalism, the behaviour of the isochore heat capacity for a trapped unitary Fermi gas is also analysed.

  17. Transport properties of natural gas through polyethylene nanocomposites at high temperature and pressure

    DEFF Research Database (Denmark)

    Adewole, Jimoh K.; Jensen, Lars; Al-Mubaiyedh, Usamah A.

    2012-01-01

    High density polyethylene (HDPE)/clay nanocomposites containing nanoclay concentrations of 1, 2.5, and 5 wt% were prepared by a melt blending process. The effects of various types of nanoclays and their concentrations on permeability, solubility, and diffusivity of natural gas in the nanocomposites...... at constant temperature had little influence on the permeability, whereas increasing the temperature from 30 to 70 degrees C significantly increased the permeability of the gas. Additionally, the effect of crystallinity on permeability, solubility, and diffusivity was investigated. Thus, the permeability...

  18. Simulation of the fuzzy-smith control system for the high temperature gas cooled reactor

    International Nuclear Information System (INIS)

    Li Deheng; Xu Xiaolin; Zheng Jie; Guo Renjun; Zhang Guifen

    1997-01-01

    The Fuzzy-Smith pre-estimate controller to solve the control of the big delay system is developed, accompanied with the development of the mathematical model of the 10 MW high temperature gas cooled test reactor (HTR-10) and the design of its control system. The simulation results show the Fuzzy-Smith pre-estimate controller has the advantages of both fuzzy control and Smith pre-estimate controller; it has better compensation to the delay and better adaptability to the parameter change of the control object. So it is applicable to the design of the control system for the high temperature gas cooled reactor

  19. Experimental studies on particle deposition by thermophoresis and inertial impaction from particulate high temperature gas flow

    International Nuclear Information System (INIS)

    Kim, S.S.; Kim, Y.J.

    1987-01-01

    In view of fouling and erosion of gas turbine blade, heat exchanger and pipelines, increasing attention has been paid to particle deposition (transport) in high temperature flow systems. This is also necessary to develop a cleaning or filtration devices. Using 'real time' laser-light reflectivity and scanning electron microscope technique, we quantitatively treat particle size effect and the interaction between Brownian diffusion, thermoporesis (particle drift down a temperature gradient), and inertial impaction of particles (0.2 to 30 μm in diameter) in laminar hot combustion gas-particles flow (ca. 1565 K)

  20. Facility Configuration Study of the High Temperature Gas-Cooled Reactor Component Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    S. L. Austad; L. E. Guillen; D. S. Ferguson; B. L. Blakely; D. M. Pace; D. Lopez; J. D. Zolynski; B. L. Cowley; V. J. Balls; E.A. Harvego, P.E.; C.W. McKnight, P.E.; R.S. Stewart; B.D. Christensen

    2008-04-01

    A test facility, referred to as the High Temperature Gas-Cooled Reactor Component Test Facility or CTF, will be sited at Idaho National Laboratory for the purposes of supporting development of high temperature gas thermal-hydraulic technologies (helium, helium-Nitrogen, CO2, etc.) as applied in heat transport and heat transfer applications in High Temperature Gas-Cooled Reactors. Such applications include, but are not limited to: primary coolant; secondary coolant; intermediate, secondary, and tertiary heat transfer; and demonstration of processes requiring high temperatures such as hydrogen production. The facility will initially support completion of the Next Generation Nuclear Plant. It will secondarily be open for use by the full range of suppliers, end-users, facilitators, government laboratories, and others in the domestic and international community supporting the development and application of High Temperature Gas-Cooled Reactor technology. This pre-conceptual facility configuration study, which forms the basis for a cost estimate to support CTF scoping and planning, accomplishes the following objectives: • Identifies pre-conceptual design requirements • Develops test loop equipment schematics and layout • Identifies space allocations for each of the facility functions, as required • Develops a pre-conceptual site layout including transportation, parking and support structures, and railway systems • Identifies pre-conceptual utility and support system needs • Establishes pre-conceptual electrical one-line drawings and schedule for development of power needs.

  1. Facility Configuration Study of the High Temperature Gas-Cooled Reactor Component Test Facility

    International Nuclear Information System (INIS)

    S. L. Austad; L. E. Guillen; D. S. Ferguson; B. L. Blakely; D. M. Pace; D. Lopez; J. D. Zolynski; B. L. Cowley; V. J. Balls; E.A. Harvego, P.E.; C.W. McKnight, P.E.; R.S. Stewart; B.D. Christensen

    2008-01-01

    A test facility, referred to as the High Temperature Gas-Cooled Reactor Component Test Facility or CTF, will be sited at Idaho National Laboratory for the purposes of supporting development of high temperature gas thermal-hydraulic technologies (helium, helium-Nitrogen, CO2, etc.) as applied in heat transport and heat transfer applications in High Temperature Gas-Cooled Reactors. Such applications include, but are not limited to: primary coolant; secondary coolant; intermediate, secondary, and tertiary heat transfer; and demonstration of processes requiring high temperatures such as hydrogen production. The facility will initially support completion of the Next Generation Nuclear Plant. It will secondarily be open for use by the full range of suppliers, end-users, facilitators, government laboratories, and others in the domestic and international community supporting the development and application of High Temperature Gas-Cooled Reactor technology. This pre-conceptual facility configuration study, which forms the basis for a cost estimate to support CTF scoping and planning, accomplishes the following objectives: (1) Identifies pre-conceptual design requirements; (2) Develops test loop equipment schematics and layout; (3) Identifies space allocations for each of the facility functions, as required; (4) Develops a pre-conceptual site layout including transportation, parking and support structures, and railway systems; (5) Identifies pre-conceptual utility and support system needs; and (6) Establishes pre-conceptual electrical one-line drawings and schedule for development of power needs

  2. Effect of temperature on the permeability of gas adsorbed coal under triaxial stress conditions

    Science.gov (United States)

    Li, Xiangchen; Yan, Xiaopeng; Kang, Yili

    2018-04-01

    The combined effects of gas sorption, stress and temperature play a significant role in the changing behavior of gas permeability in coal seams. The effect of temperature on nitrogen and methane permeability of naturally fractured coal is investigated. Coal permeability, P-wave velocity and axial strain were simultaneously measured under two effective stresses and six different temperatures. The results showed that the behavior of nitrogen and methane permeability presented nonmonotonic changes with increasing temperature. The variation in the P-wave velocity and axial strain showed a good correspondence with coal permeability. A higher effective stress limited the bigger deformation and caused the small change in permeability. Methane adsorption and desorption significantly influence the mechanical properties of coal and play an important role in the variations in coal permeability. The result of coal permeability during a complete stress-strain process showed that the variation in permeability is determined by the evolution of the internal structure. The increase in the temperature of the gas saturated coal causes the complex interaction between matrix swelling, matrix shrinkage and micro-fracture generation, which leads to the complex changes in coal structure and permeability. These results are helpful to understand the gas transport mechanism for exploiting coal methane by heat injection.

  3. Design study on evaluation for power conversion system concepts in high temperature gas cooled reactor with gas turbine

    International Nuclear Information System (INIS)

    Minatsuki, Isao; Mizokami, Yorikata

    2007-01-01

    The design studies on High Temperature Gas Cooled Reactor with Gas Turbine (HTGR-GT) have been performed, which were mainly promoted by Japan Atomic Energy Agency (JAEA) and supported by fabricators in Japan. HTGR-GT plant feature is almost determined by selection of power conversion system concepts. Therefore, plant design philosophy is observed characteristically in selection of them. This paper describes the evaluation and analysis of the essential concepts of the HTGR-GT power conversion system through the investigations based on our experiences and engineering knowledge as a fabricator. As a result, the following concepts were evaluated that have advantages against other competitive one, such as the horizontal turbo machine rotor, the turbo machine in an individual vessel, the turbo machine with single shaft, the generator inside the power conversion vessel, and the power conversion system cycle with an intercooler. The results of the study can contribute as reference data when the concepts will be selected. Furthermore, we addressed reasonableness about the concept selection of the Gas Turbine High Temperature Reactor GTHTR300 power conversion system, which has been promoted by JAEA. As a conclusion, we recognized the GTHTR300 would be one of the most promising concepts for commercialization in near future. (author)

  4. High-Temperature Corrosion Behavior of Alloy 617 in Helium Environment of Very High Temperature Gas Reactor

    International Nuclear Information System (INIS)

    Lee, Gyeong-Geun; Jung, Sujin; Kim, Daejong; Jeong, Yong-Whan; Kim, Dong-Jin

    2012-01-01

    Alloy 617 is a Ni-base superalloy and a candidate material for the intermediate heat exchanger (IHX) of a very high temperature gas reactor (VHTR) which is one of the next generation nuclear reactors under development. The high operating temperature of VHTR enables various applications such as mass production of hydrogen with high energy efficiency. Alloy 617 has good creep resistance and phase stability at high temperatures in an air environment. However, it was reported that the mechanical properties decreased at a high temperature in an impure helium environment. In this study, high-temperature corrosion tests were carried out at 850°C-950°C in a helium environment containing the impurity gases H_2, CO, and CH_4, in order to examine the corrosion behavior of Alloy 617. Until 250 h, Alloy 617 specimens showed a parabolic oxidation behavior at all temperatures. The activation energy for oxidation in helium environment was 154 kJ/mol. The SEM and EDS results elucidated a Cr-rich surface oxide layer, Al-rich internal oxides and depletion of grain boundary carbides. The thickness and depths of degraded layers also showed a parabolic relationship with time. A normal grain growth was observed in the Cr-rich surface oxide layer. When corrosion tests were conducted in a pure helium environment, the oxidation was suppressed drastically. It was elucidated that minor impurity gases in the helium would have detrimental effects on the high temperature corrosion behavior of Alloy 617 for the VHTR application.

  5. Effects of Loading Rate on Gas Seepage and Temperature in Coal and Its Potential for Coal-Gas Disaster Early-Warning

    Directory of Open Access Journals (Sweden)

    Chong Zhang

    2017-08-01

    Full Text Available The seepage velocity and temperature externally manifest the changing structure, gas desorption and energy release that occurs in coal containing gas failure under loading. By using the system of coal containing gas failure under loading, this paper studies the law of seepage velocity and temperature under different loading rates and at 1.0 MPa confining pressure and 0.5 MPa gas pressure, and combined the on-site results of gas pressure and temperature. The results show that the stress directly affects the seepage velocity and temperature of coal containing gas, and the pressure and content of gas have the most sensitivity to mining stress. Although the temperature is not sensitive to mining stress, it has great correlation with mining stress. Seepage velocity has the characteristic of critically slowing down under loading. This is demonstrated by the variance increasing before the main failure of the samples. Therefore, the variance of seepage velocity with time and temperature can provide an early warning for coal containing gas failing and gas disasters in a coal mine.

  6. Numerical investigation of heat transfer in high-temperature gas-cooled reactors

    Energy Technology Data Exchange (ETDEWEB)

    Chen, g.; Anghaie, S. [Univ. of Florida, Gainesville, FL (United States)

    1995-09-01

    This paper proposes a computational model for analysis of flow and heat transfer in high-temperature gas-cooled reactors. The formulation of the problem is based on using the axisymmetric, thin layer Navier-Stokes equations. A hybrid implicit-explicit method based on finite volume approach is used to numerically solve the governing equations. A fast converging scheme is developed to accelerate the Gauss-Siedel iterative method for problems involving the wall heat flux boundary condition. Several cases are simulated and results of temperature and pressure distribution in the core are presented. Results of a parametric analysis for the assessment of the impact of power density on the convective heat transfer rate and wall temperature are discussed. A comparative analysis is conducted to identify the Nusselt number correlation that best fits the physical conditions of the high-temperature gas-cooled reactors.

  7. Fundamental conceptual design of the experimental multi-purpose high-temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Shimokawa, Junichi; Yasuno, Takehiko; Yasukawa, Shigeru; Mitake, Susumu; Miyamoto, Yoshiaki

    1975-06-01

    The fundamental conceptual design of the experimental multi-purpose very high-temperature gas-cooled reactor (experimental VHTR of thermal output 50 MW with reactor outlet-gas temperature 1,000 0 C) has been carried out to provide the operation modes of the system consisting of the reactor and the heat-utilization system, including characteristics and performance of the components and safety of the plant system. For the heat-utilization system of the plant, heat distribution, temperature condition, cooling system constitution, and the containment facility are specified. For the operation of plant, testing capability of the reactor and controlability of the system are taken into consideration. Detail design is made of the fuel element, reactor core, reactivity control and pressure vessel, and also the heat exchanger, steam reformer, steam generator, helium circulator, helium-gas turbine, and helium-gas purification, fuel handling, and engineered safety systems. Emphasis is placed on providing the increase of the reactor outlet-gas temperature. Fuel element design is directed to the prismatic graphite blocks of hexagonal cross-section accommodating the hollow or tubular fuel pins sheathed in graphite sleeve. The reactor core is composed of 73 fuel columns in 7 stages, concerning the reference design MK-II. Orificing is made in the upper portion of core; one orifice for every 7 fuel columns. Average core power density is 2.5 watts/cm 3 . Fuel temperature is kept below 1,300 0 C in rated power. The main components, i.e. pressure vessel, reformer, gas turbine and intermediate heat exchanger are designed in detail; the IHX is of a double-shell and helically-wound tube coils, the reformer is of a byonet tube type, and the turbine-compressor unit is of an axial flow type (turbine in 6 stages and compressor in 16 stages). (auth.)

  8. Low-temperature thermometry. Use of a gas thermometer as a calibration standard between 4 and 300 K

    International Nuclear Information System (INIS)

    Combarieu, A. de

    1978-01-01

    A constant volume gas thermometer was built to calibrate the various secondary thermometers used at low temperature. This gas thermometer is placed in a cryostat where any stable temperature between 4 and 300 K may be obtained. After some words about low temperature thermometry, the gas thermometer and its auxiliary equipment are described briefly; the corrections to be applied to the results are given and the article ends with a table showing the values obtained [fr

  9. Mathematical Simulation of Convective Heat Transfer in the Low-Temperature Storage of Liquefied Natural Gas

    OpenAIRE

    Shestakov, Igor; Dolgova, Anastasia; Maksimov, Vyacheslav Ivanovich

    2015-01-01

    The article shows the results of mathematical modeling of convective heat transfer in the low-temperature storage of liquefied natural gas. Regime of natural convection in an enclosure with different intensity of the heat flux at the external borders are investigated. Was examined two-dimensional nonstationary problem within the model of Navier-Stokes in dimensionless variables “vorticity - stream function - temperature”. Distributions of hydrodynamic parameters and temperatures that characte...

  10. High Temperature Gas-Cooled Reactors Lessons Learned Applicable to the Next Generation Nuclear Plant

    International Nuclear Information System (INIS)

    Beck, J.M.; Collins, J.W.; Garcia, C.B.; Pincock, L.F.

    2010-01-01

    High Temperature Gas Reactors (HTGR) have been designed and operated throughout the world over the past five decades. These seven HTGRs are varied in size, outlet temperature, primary fluid, and purpose. However, there is much the Next Generation Nuclear Plant (NGNP) has learned and can learn from these experiences. This report captures these various experiences and documents the lessons learned according to the physical NGNP hardware (i.e., systems, subsystems, and components) affected thereby.

  11. Investigation into relative temperature measurement of pulsed constrained gas flow using passive acoustic means

    OpenAIRE

    Moss, Joseph Brian

    2011-01-01

    peer-reviewed The requirement to measure the real time, dynamic temperature of exhaust system gases is becoming more and more important in the areas of aeronautics, automotive (cars, trucks, etc), marine and industrial/environmental applications, in particular on a cycleby-cycle (CBC) basis. Monitoring exhaust gas temperatures of any power-plant can give important diagnostic information for the monitoring of fuel mixture, combustion efficiency etc. This 'diagnostic' information can b...

  12. Multi-contaminant analysis of organophosphate and halogenated flame retardants in food matrices using ultrasonication and vacuum assisted extraction, multi-stage cleanup and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Xu, Fuchao; García-Bermejo, Ángel; Malarvannan, Govindan; Gómara, Belén; Neels, Hugo; Covaci, Adrian

    2015-07-03

    A multi-residue analytical method was developed for the determination of a range of flame retardants (FRs), including polybrominated diphenyl ethers (PBDEs), emerging halogenated FRs (EFRs) and organophosphate FRs (PFRs), in food matrices. An ultrasonication and vacuum assisted extraction (UVAE), followed by a multi-stage clean-up procedure, enabled the removal of up to 1g of lipid from 2.5 g of freeze-dried food samples and significantly reduce matrix effects. UVAE achieves a waste factor (WF) of about 10%, while the WFs of classical QuEChERS methods range usually between 50 and 90%. The low WF of UVAE leads to a dramatic improvement in the sensitivity along with saving up to 90% of spiking (internal) standards. Moreover, a two-stage clean-up on Florisil and aminopropyl silica was introduced after UVAE, for an efficient removal of pigments and residual lipids, which led to cleaner extracts than normally achieved by dispersive solid phase extraction (d-SPE). In this way, the extracts could be concentrated to low volumes, e.g. analysis of PFRs was performed on GC-EI-MS, while PBDEs and EFRs were measured by GC-ECNI-MS. Validation tests were performed with three food matrices (lean beef, whole chicken egg and salmon filet), obtaining acceptable recoveries (66-135%) with good repeatability (RSD 1-24%, mean 7%). Method LOQs ranged between 0.008 and 0.04 ng/g dw for PBDEs, between 0.08 and 0.20 ng/g dw for EFRs, and between 1.4 and 3.6 ng/g dw for PFRs. The method was further applied to eight types of food samples (including meat, eggs, fish, and seafood) with lipid contents ranging from 0.1 to 22%. Various FRs were detected above MLOQ levels, demonstrating the wide-range applicability of our method. To the best of our knowledge, this is the first method reported for simultaneous analysis of brominated and organophosphate FRs in food matrices. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Acoustic transducer in system for gas temperature measurement in gas turbine engine

    Science.gov (United States)

    DeSilva, Upul P.; Claussen, Heiko

    2017-07-04

    An apparatus for controlling operation of a gas turbine engine including at least one acoustic transmitter/receiver device located on a flow path boundary structure. The acoustic transmitter/receiver device includes an elongated sound passage defined by a surface of revolution having opposing first and second ends and a central axis extending between the first and second ends, an acoustic sound source located at the first end, and an acoustic receiver located within the sound passage between the first and second ends. The boundary structure includes an opening extending from outside the boundary structure to the flow path, and the second end of the surface of revolution is affixed to the boundary structure at the opening for passage of acoustic signals between the sound passage and the flow path.

  14. Heat and momentum transfer in a gas coolant flow through a circular pipe in a high temperature gas cooled reactor

    International Nuclear Information System (INIS)

    Ogawa, Masuro

    1989-07-01

    In Japan Atomic Energy Research Institute (JAERI), a very high temperature gas cooled reactor (VHTR) has been researched and developed with a purpose of attaining a coolant temperature of around 1000degC at the reactor outlet. In order to design VHTR, comprehensive knowledge is required on thermo-hydraulic characteristics of laminar-turbulent transition, of coolant flow with large thermal property variation due to temperature difference, and of heat transfer deterioration. In the present investigation, experimental and analytical studies are made on a gas flow in a circular tube to elucidate the thermo-hydraulic characteristics. Friction factors and heat transfer coefficients in transitional flows are obtained. Influence of thermal property variation on the friction factor is qualitatively determined. Heat transfer deterioration in the turbulent flow subjected to intense heating is experimentally found to be caused by flow laminarization. The analysis based on a k-kL two-equation model of turbulence predicts well the experimental results on friction factors and heat transfer coefficients in flows with thermal property variation and in laminarizing flows. (author)

  15. Assessment, Cleanup and Redevelopment Exchange System (ACRES)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Assessment, Cleanup and Redevelopment Exchange System (ACRES) is an online database for Brownfields Grantees to electronically submit data directly to EPA.

  16. Increased leukemia risk in Chernobyl cleanup workers

    Science.gov (United States)

    A new study found a significantly elevated risk for chronic lymphocytic leukemia among workers who were engaged in recovery and clean-up activities following the Chernobyl power plant accident in 1986.

  17. Mass flow discharge and total temperature characterisation of a pyrotechnic gas generator formulation for airbag systems

    Energy Technology Data Exchange (ETDEWEB)

    Neutz, Jochen; Koenig, Andreas [Fraunhofer Institut fuer Chemische Technologie ICT, Pfinztal (Germany); Knauss, Helmut; Jordan, Sebastian; Roediger, Tim; Smorodsky, Boris [Universitaet Stuttgart (Germany). Institut fuer Aerodynamik und Gasdynamik; Bluemcke, Erich Walter [AUDI AG, Department I/EK-523, Ingolstadt (Germany)

    2009-06-15

    The mass flow characteristics of gas generators for airbag applications have to comply with a number of requirements for an optimal deployment of the airbag itself. Up to now, the mass flow was determined from pressure time histories of so-called can tests. This procedure suffers from the missing knowledge on the temperature of the generated gas entering the can. A new test setup described in this paper could overcome this problem by providing highly time resolved information on the gas's total temperature and the mass flow of the generator. The test setup consisted of a combustion chamber with a specially designed Laval nozzle in combination with a temperature sensor of high time resolution. The results showed a high time resolved temperature signal, which was disturbed by the formation of a slag layer on the sensor. Plausibility considerations with experimentally and thermodynamically determined combustion temperatures led to satisfying results for the overall temperature as characteristic parameter of airbag inflating gases flows from pyrotechnics. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  18. High temperature hydrogen sulfide adsorption on activated carbon - I. Effects of gas composition and metal addition

    Science.gov (United States)

    Cal, M.P.; Strickler, B.W.; Lizzio, A.A.

    2000-01-01

    Various types of activated carbon sorbents were evaluated for their ability to remove H2S from a simulated coal gas stream at a temperature of 550 ??C. The ability of activated carbon to remove H2S at elevated temperature was examined as a function of carbon surface chemistry (oxidation, thermal desorption, and metal addition), and gas composition. A sorbent prepared by steam activation, HNO3 oxidation and impregnated with Zn, and tested in a gas stream containing 0.5% H2S, 50% CO2 and 49.5% N2, had the greatest H2S adsorption capacity. Addition of H2, CO, and H2O to the inlet gas stream reduced H2S breakthrough time and H2S adsorption capacity. A Zn impregnated activated carbon, when tested using a simulated coal gas containing 0.5% H2S, 49.5% N2, 13% H2, 8.5% H2O, 21% CO, and 7.5% CO2, had a breakthrough time of 75 min, which was less than 25 percent of the length of breakthrough for screening experiments performed with a simplified gas mixture of 0.5% H2S, 50% CO2, and 49.5% N2.

  19. Bioavailability: implications for science/cleanup policy

    Energy Technology Data Exchange (ETDEWEB)

    Denit, Jeffery; Planicka, J. Gregory

    1998-12-01

    This paper examines the role of bioavailability in risk assessment and cleanup decisions. Bioavailability refers to how chemicals ''behave'' and their ''availability'' to interact with living organisms. Bioavailability has significant implications for exposure risks, cleanup goals, and site costs. Risk to human health and the environment is directly tied to the bioavailability of the chemicals of concern.

  20. Analysis of Precooling Injection Transient of Steam Generator for High Temperature Gas Cooled Reactor

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2017-01-01

    Full Text Available After a postulated design basis accident leads high temperature gas cooled reactor to emergency shutdown, steam generator still remains with high temperature level and needs to be cooled down by a precooling before reactor restarts with clearing of fault. For the large difference of coolant temperature between inlet and outlet of steam generator in normal operation, the temperature distribution on the components of steam generator is very complicated. Therefore, the temperature descending rate of the components in steam generator needs to be limited to avoid the potential damage during the precooling stage. In this paper, a pebble-bed high temperature gas cooled reactor is modeled by thermal-hydraulic system analysis code and several postulated precooling injection transients are simulated and compared to evaluate their effects, which will provide support for the precooling design. The analysis results show that enough precooling injection is necessary to satisfy the precooling requirements, and larger mass flow rate of precooling water injection will accelerate the precooling process. The temperature decrease of steam generator is related to the precooling injection scenarios, and the maximal mass flow rate of the precooling injection should be limited to avoid the excessively quick temperature change of the structures in steam generator.

  1. Long wavelength infrared radiation thermometry for non-contact temperature measurements in gas turbines

    Science.gov (United States)

    Manara, J.; Zipf, M.; Stark, T.; Arduini, M.; Ebert, H.-P.; Tutschke, A.; Hallam, A.; Hanspal, J.; Langley, M.; Hodge, D.; Hartmann, J.

    2017-01-01

    The objective of the EU project "Sensors Towards Advanced Monitoring and Control of Gas Turbine Engines (acronym STARGATE)" is the development of a suite of advanced sensors, instrumentation and related systems in order to contribute to the developing of the next generation of green and efficient gas turbine engines. One work package of the project deals with the design and development of a long wavelength infrared (LWIR) radiation thermometer for the non-contact measurement of the surface temperature of thermal barrier coatings (TBCs) during the operation of gas turbine engines. For opaque surfaces (e.g. metals or superalloys) radiation thermometers which are sensitive in the near or short wavelength infrared are used as state-of-the-art method for non-contact temperature measurements. But this is not suitable for oxide ceramic based TBCs (e.g. partially yttria stabilized zirconia) as oxide ceramics are semi-transparent in the near and short wavelength infrared spectral region. Fortunately the applied ceramic materials are non-transparent in the long wavelength infrared and additionally exhibit a high emittance in this wavelength region. Therefore, a LWIR pyrometer can be used for non-contact temperature measurements of the surfaces of TBCs as such pyrometers overcome the described limitation of existing techniques. For performing non-contact temperature measurements in gas turbines one has to know the infrared-optical properties of the applied TBCs as well as of the hot combustion gas in order to properly analyse the measurement data. For reaching a low uncertainty on the one hand the emittance of the TBC should be high (>0.9) in order to reduce reflections from the hot surrounding and on the other hand the absorbance of the hot combustion gas should be low (<0.1) in order to decrease the influence of the gas on the measured signal. This paper presents the results of the work performed by the authors with focus on the implementation of the LWIR pyrometer and the

  2. Interstellar Gas Flow Vector and Temperature Determination over 5 Years of IBEX Observations

    International Nuclear Information System (INIS)

    Möbius, E; Heirtzler, D; Kucharek, H; Lee, M A; Leonard, T; Schwadron, N; Bzowski, M; Kubiak, M A; Sokół, J M; Fuselier, S A; McComas, D J; Wurz, P

    2015-01-01

    The Interstellar Boundary Explorer (IBEX) observes the interstellar neutral gas flow trajectories at their perihelion in Earth's orbit every year from December through early April, when the Earth's orbital motion is into the oncoming flow. These observations have defined a narrow region of possible, but very tightly coupled interstellar neutral flow parameters, with inflow speed, latitude, and temperature as well-defined functions of inflow longitude. The best- fit flow vector is different by ≈ 3° and lower by ≈ 3 km/s than obtained previously with Ulysses GAS, but the temperature is comparable. The possible coupled parameter space reaches to the previous flow vector, but only for a substantially higher temperature (by ≈ 2000 K). Along with recent pickup ion observations and including historical observations of the interstellar gas, these findings have led to a discussion, whether the interstellar gas flow into the solar system has been stable or variable over time. These intriguing possibilities call for more detailed analysis and a longer database. IBEX has accumulated observations over six interstellar flow seasons. We review key observations and refinements in the analysis, in particular, towards narrowing the uncertainties in the temperature determination. We also address ongoing attempts to optimize the flow vector determination through varying the IBEX spacecraft pointing and discuss related implications for the local interstellar cloud and its interaction with the heliosphere

  3. Design activity of IHI on the experimental multipurpose high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    1978-01-01

    With conspicuous interest and attention paid by iron and steel manufacturing industries, the development of the multipurpose high temperature gas-cooled reactor, namely the process heat reactor has been energetically discussed in Japan. The experimental multipurpose high temperature gas-cooled reactor, planned by JAERI (the Japan Atomic Energy Research Institute), is now at the end of the adjustment design stage and about to enter the system synthesizing design stage. The design of the JAERI reactor as a pilot plant for process heat reactors that make possible the direct use of the heat, produced in the reactor, for other industrial uses was started in 1969, and has undergone several revisions up to now. The criticality of the JAERI reactor is expected to be realized before 1985 according to the presently published program. IHI has engaged in the developing work of HTGR (high temperature gas-cooled reactor) including VHTR (very high temperature gas-cooled reactor) for over seven years, producing several achievements. IHI has also participated in the JAERI project since 1973 with some other companies concerned in this field. The design activity of IHI in the development of the JAERI reactor is briefly presented in this paper. (auth.)

  4. Megawatt low-temperature DC plasma generator with divergent channels of gas-discharge tract

    Science.gov (United States)

    Gadzhiev, M. Kh.; Isakaev, E. Kh.; Tyuftyaev, A. S.; Yusupov, D. I.; Sargsyan, M. A.

    2017-04-01

    We have developed and studied a new effective megawatt double-unit generator of low-temperature argon plasma, which belongs to the class of dc plasmatrons and comprises the cathode and anode units with divergent gas-discharge channels. The generator has an efficiency of about 80-85% and ensures a long working life at operating currents up to 4000 A.

  5. Large-volume injection in gas chromatographic trace analysis using temperature-programmable (PTV) injectors

    NARCIS (Netherlands)

    Mol, J.G.J.; Janssen, J.G.M.; Cramers, C.A.M.G.; Brinkman, U.A.T.

    1996-01-01

    The use of programmed-temperature vaporising (PTV) injectors for large-volume injection in capillary gas chromatography is briefly reviewed. The principles and optimisation of large-volume PTV injection are discussed. Guidelines are given for selection of the PTV conditions and injection mode for

  6. Sodium and cover gas chemistry in the high temperature sodium facility

    International Nuclear Information System (INIS)

    McCown, J.J.; Duncan, H.C.

    1976-01-01

    The equipment and procedures used in following sodium and cover gas chemistry changes in the High Temperature Sodium Facility are presented. The methods of analysis and results obtained are given. Impurity trends which have been measured during the facility operations are discussed

  7. Technology development for the modular high-temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Homan, F.J.; Turner, R.F.

    1989-01-01

    In the USA the Modular High-Temperature Gas-Cooled Reactor is in an advanced stage of design. The related HTGR program areas, the approaches to these programs along with sample results and a description of how these data are used are highlighted in the paper. (author). Figs and tabs

  8. Detection of H2S gas at lower operating temperature using sprayed ...

    Indian Academy of Sciences (India)

    Nanostructured In2O3; thin films; spray pyrolysis; H2S gas sensor; low temperature. 1. Introduction ... nozzle to and fro frequency (16 cycles/min), nozzle to sub- ... were confirmed by measuring the thermoelectric power of the thin film samples.

  9. Temperature Evolution of a 1 MA Triple-Nozzle Gas-Puff Z-Pinch

    Science.gov (United States)

    de Grouchy, Philip; Banasek, Jacob; Engelbrecht, Joey; Qi, Niansheng; Atoyan, Levon; Byvank, Tom; Cahill, Adam; Moore, Hannah; Potter, William; Ransohoff, Lauren; Hammer, David; Kusse, Bruce; Laboratory of Plasma Studies Team

    2015-11-01

    Mitigation of the Rayleigh-Taylor instability (RTI) plays a critical role in optimizing x-ray output at high-energy ~ 13 keV using the triple-nozzle Krypton gas-puff at Sandia National Laboratory. RTI mitigation by gas-puff density profiling using a triple-nozzle gas-puff valve has recently been recently demonstrated on the COBRA 1MA z-pinch at Cornell University. In support of this work we investigate the role of shell cooling in the growth of RTI during gas-puff implosions. Temperature measurements within the imploding plasma shell are recorded using a 527 nm, 10 GW Thomson scattering diagnostic for Neon, Argon and Krypton puffs. The mass-density profile is held constant at 22 microgram per centimeter for all three puffs and the temperature evolution of the imploding material is recorded. In the case of Argon puffs we find that the shell ion and electron effective temperatures remain in equilibrium at around 1keV for the majority of the implosion phase. In contrast scattered spectra from Krypton are dominated by of order 10 keV effective ion temperatures. Supported by the NNSA Stewardship Sciences Academic Programs.

  10. Design of project management system for 10 MW high temperature gas-cooled test reactor

    International Nuclear Information System (INIS)

    Zhu Yan; Xu Yuanhui

    1998-01-01

    A framework of project management information system (MIS) for 10 MW high temperature gas-cooled test reactor is introduced. Based on it, the design of nuclear project management information system and project monitoring system (PMS) are given. Additionally, a new method of developing MIS and Decision Support System (DSS) has been tried

  11. Summary of ORNL high-temperature gas-cooled reactor program

    International Nuclear Information System (INIS)

    Kasten, P.R.

    1981-01-01

    Oak Ridge National Laboratory (ORNL) efforts on the High-Temperature Gas-Cooled Reactor (HTGR) Program have been on HTGR fuel development, fission product and coolant chemistry, prestressed concrete reactor vessel (PCRV) studies, materials studies, graphite development, reactor physics and shielding studies, application assessments and evaluations and selected component testing

  12. Trends in low-temperature water–gas shift reactivity on transition metals

    DEFF Research Database (Denmark)

    Schumacher, Nana Maria Pii; Boisen, Astrid; Dahl, Søren

    2005-01-01

    Low-temperature water–gas shift reactivity trends on transition metals were investigated with the use of a microkinetic model based on a redox mechanism. It is established that the adsorption energies for carbon monoxide and oxygen can describe to a large extent changes in the remaining activation...

  13. Robust control of speed and temperature in a power plant gas turbine.

    Science.gov (United States)

    Najimi, Ebrahim; Ramezani, Mohammad Hossein

    2012-03-01

    In this paper, an H(∞) robust controller has been designed for an identified model of MONTAZER GHAEM power plant gas turbine (GE9001E). In design phase, a linear model (ARX model) which is obtained using real data has been applied. Since the turbine has been used in a combined cycle power plant, its speed and also the exhaust gas temperature should be adjusted simultaneously by controlling fuel signals and compressor inlet guide vane (IGV) position. Considering the limitations on the system inputs, the aim of the control is to maintain the turbine speed and the exhaust gas temperature within desired interval under uncertainties and load demand disturbances. Simulation results of applying the proposed robust controller on the nonlinear model of the system (NARX model), fairly fulfilled the predefined aims. Simulations also show the improvement in the performance compared to MPC and PID controllers for the same conditions. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

  14. Preliminary analysis of combined cycle of modular high-temperature gas cooled reactor

    International Nuclear Information System (INIS)

    Baogang, Z.; Xiaoyong, Y.; Jie, W.; Gang, Z.; Qian, S.

    2015-01-01

    Modular high-temperature gas cooled reactor (HTGR) is known as one of the most advanced nuclear reactors because of its inherent safety and high efficiency. The power conversion system of HTGR can be steam turbine based on Rankine cycle or gas turbine based on Brayton cycle respectively. The steam turbine system is mature and the gas turbine system has high efficiency but under development. The Brayton-Rankine combined cycle is an effective way to further promote the efficiency. This paper investigated the performance of combined cycle from the viewpoint of thermodynamics. The effect of non-dimensional parameters on combined cycle’s efficiency, such as temperature ratio, compression ratio, efficiency of compressor, efficiency of turbine, was analyzed. Furthermore, the optimal parameters to achieve highest efficiency was also given by this analysis under engineering constraints. The conclusions could be helpful to the design and development of combined cycle of HTGR. (author)

  15. Spatially Resolved Gas Temperature Measurements in an Atmospheric Pressure DC Glow Microdischarge with Raman Scattering

    Science.gov (United States)

    Belostotskiy, S.; Wang, Q.; Donnelly, V.; Economou, D.; Sadeghi, N.

    2006-10-01

    Spatially resolved rotational Raman spectroscopy of ground state nitrogen N2(X^1σg^+) was used to measure the gas temperature (Tg) in a nitrogen dc glow microdischarge (gap between electrodes d˜500 μm). An original backscattering, confocal optical system was developed for collecting Raman spectra. Stray laser light and Raleigh scattering were blocked by using a triple grating monochromator and spatial filters, designed specifically for these experiments. The optical system provided a spatial resolution of electrodes, Tg increased linearly with jd, reaching 500 K at 1000 mA/cm^2 jd for a pressure of 720 Torr. Spatially resolved gas temperature measurements will also be presented and discussed in combination with a mathematical model for gas heating in the microplasma. This work is supported by DoE/NSF.

  16. Heat exchanger for transfering heat produced in a high temperature reactor to an intermediate circuit gas

    International Nuclear Information System (INIS)

    Barchewitz, E.; Baumgaertner, H.

    1985-01-01

    The invention is concerned with improving the arrangement of a heat exchanger designed to transfer heat from the coolant gas circuit of a high temperature reactor to a gas which is to be used for a process heat plant. In the plant the material stresses are to be kept low at high differential pressures and temperatures. According to the invention the tube bundles designed as boxes are fixed within the heat exchanger closure by means of supply pipes having got loops. For conducting the hot gas the heat exchanger has got a central pipe leading out of the reactor vessel through the pod closure and having got only one point of fixation, lying in this closure. Additional advantageous designs are mentioned. (orig./PW)

  17. Credibility and trust in federal facility cleanups

    International Nuclear Information System (INIS)

    Raynes, D.B.

    1995-01-01

    The most important indicator of a well-managed site cleanup effort may no longer be funding or scientific expertise. While support for federal facility cleanup has included appropriations of more than $10 billion annually, these expenditures alone are unlikely to assure progress toward environmental remediation. open-quotes Trustclose quotes is now overwhelmingly mentioned as a prerequisite for progress with site cleanup in DOE's weapons complex. In part, federal budget deficits are forcing participants to focus on factors that build consensus and lead to cost-effective cleanup actions. In some cases, the stakeholders at cleanup sites are making efforts to work cooperatively with federal agencies. A report by 40 representatives of federal agencies, tribal and state governments, associations, and others developed recommendations to create a open-quotes new era of trust and consensus-building that allows all parties to get on with the job of cleaning up federal facilities in a manner that reflects the priorities and concerns of all stakeholders.close quotes Changes are underway affecting how federal agencies work with federal and state regulators reflecting this concept of shared responsibility for conducting cleanup. This paper addresses these changes and provides examples of the successes and failures underway

  18. HARVESTING EMSP RESEARCH RESULTS FOR WASTE CLEANUP

    International Nuclear Information System (INIS)

    Guillen, Donna Post; Nielson, R. Bruce; Phillips, Ann Marie; Lebow, Scott

    2003-01-01

    The extent of environmental contamination created by the nuclear weapons legacy combined with expensive, ineffective waste cleanup strategies at many U.S. Department of Energy (DOE) sites prompted Congress to pass the FY96 Energy and Water Development Appropriations Act, which directed the DOE to: ''provide sufficient attention and resources to longer-term basic science research, which needs to be done to ultimately reduce cleanup costs'', ''develop a program that takes advantage of laboratory and university expertise, and'' ''seek new and innovative cleanup methods to replace current conventional approaches which are often costly and ineffective.'' In response, the DOE initiated the Environmental Management Science Program (EMSP)-a targeted, long-term research program intended to produce solutions to DOE's most pressing environmental problems. EMSP funds basic research to lower cleanup cost and reduce risk to workers, the public, and the environment; direct the nation's scientific infrastructure towards cleanup of contaminated waste sites; and bridge the gap between fundamental research and technology development activities. EMSP research projects are competitively awarded based on the project's scientific, merit coupled with relevance to addressing DOE site needs. This paper describes selected EMSP research projects with long, mid, and short-term deployment potential and discusses the impacts, focus, and results of the research. Results of EMSP research are intended to accelerate cleanup schedules, reduce cost or risk for current baselines, provide alternatives for contingency planning, or provide solutions to problems where no solutions exist

  19. Thermodynamic data for selected gas impurities in the primary coolant of high-temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Feber, R.C.

    1976-12-01

    The literature of thermodynamic data for selected fission-product species is reviewed and supplemented in support of complex chemical equilibrium calculations applied to fission-product distributions in the primary coolant of high-temperature gas-cooled reactors. Thermodynamic functions and heats and free energies of formation are calculated and tabulated to 3000 0 K for CsI (s,l,g), Cs 2 I 2 (g), CH 3 I(g), COI 2 (g), and CsH(g). 79 references

  20. Circulating and plateout activity program for gas-cooled reactors with arbitrary radioactive chains

    International Nuclear Information System (INIS)

    Apperson, C.E. Jr.

    1978-03-01

    A time-dependent method for estimating the fuel body, circulating, plateout, and filter inventory of a high temperature gas-cooled reactor (HTGR) during normal operation is discussed. The primary coolant model accounts for the source, buildup, decay, and cleanup of isotopes that are gas borne inside the prestressed concrete reactor vessel (PCRV). This method has been implemented in the SUVIUS computer program that is described in detail

  1. Gas leak tightness of SiC/SiC composites at elevated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Hayasaka, Daisuke, E-mail: hayasaka@oasis.muroran-it.ac.jp [OASIS, Muroran Institute of Technology, Muroran, Hokkaido (Japan); Graduate School of Engineering, Muroran Institute of Technology, Muroran, Hokkaido (Japan); Park, Joon-Soo. [OASIS, Muroran Institute of Technology, Muroran, Hokkaido (Japan); Kishimoto, Hirotatsu [OASIS, Muroran Institute of Technology, Muroran, Hokkaido (Japan); Graduate School of Engineering, Muroran Institute of Technology, Muroran, Hokkaido (Japan); Kohyama, Akira [OASIS, Muroran Institute of Technology, Muroran, Hokkaido (Japan)

    2016-11-01

    Highlights: • NITE-SiC/SiC has extremely densified microstructure compared with other SiC/SiC composite like CVI. • Excellent helium and hydrogen gas-leak tightness of SiC/SiC composites by DEMO-NITE method from prototype industrialization production line was presented. • The excellence against stainless steel and Zircaloy at elevated temperature, together with generic excellent properties of SiC will be inevitable for innovative blanket and divertors for DEMO- and power- fusion reactors. - Abstract: SiC/SiC composite materials are attractive candidates for high heat flux components and blanket of fusion reactor, mainly due to their high temperature properties, radiation damage tolerance and low induced radioactivity. One of the challenges for SiC/SiC application in fusion reactors is to satisfy sufficient gas leak tightness of hydrogen and helium isotopes. Although many efforts have been carried-out, SiC/SiC composites by conventional processes have not been successful to satisfy the requirements, except SiC/SiC composites by NITE-methods. Toward the early realization of SiC/SiC components into fusion reactor systems process development of NITE-process has been continued. Followed to the brief introduction of recently developed DEMO-NITE process, baseline properties and hydrogen and helium gas leak tightness is presented. SiC/SiC claddings with 10 mm in diameter and 1 mm in wall thickness are tested by gas leak tightness system developed. The leak tightness measurements are done room temperature to 400 °C. Excellent gas leak tightness equivalent or superior to Zircaloy claddings for light water fission reactors is confirmed. The excellent gas leak tightness suggests nearly perfect suppression of large gas leak path in DEMO-NITE SiC/SiC.

  2. Gas reactor and associated nuclear experience in the UK relevant to high temperature reactor engineering

    International Nuclear Information System (INIS)

    Beech, D.J.; May, R.

    2000-01-01

    In the UK, the NNC played a leading role in the design and build of all of the UK's commercial magnox reactors and advanced gas-cooled reactors (AGRs). It was also involved in the DRAGON project and was responsible for producing designs for large scale HTRs and other gas reactor designs employing helium and carbon dioxide coolants. This paper addresses the gas reactor experience and its relevance to the current HTR designs under development which use helium as the coolant, through the consideration of a representative sample of the issues addressed in the UK by the NNC in support of the AGR and other reactor programmes. Modern HTR designs provide unique engineering challenges. The success of the AGR design, reflected in the extended lifetimes agreed upon by the licensing authorities at many stations, indicates that these challenges can be successfully overcome. The UK experience is unique and provides substantial support to future gas reactor and high temperature engineering studies. (authors)

  3. Temperature and coupling dependence of the universal contact intensity for an ultracold Fermi gas

    International Nuclear Information System (INIS)

    Palestini, F.; Perali, A.; Pieri, P.; Strinati, G. C.

    2010-01-01

    Physical properties of an ultracold Fermi gas in the temperature-coupling phase diagram can be characterized by the contact intensity C, which enters the pair-correlation function at short distances and describes how the two-body problem merges into its surrounding. We show that the local order established by pairing fluctuations about the critical temperature T c of the superfluid transition considerably enhances the contact C in a temperature range where pseudogap phenomena are maximal. Our ab initio results for C in a trap compare well with recently available experimental data over a wide coupling range. An analysis is also provided for the effects of trap averaging on C.

  4. High temperature and high pressure gas cell for quantitative spectroscopic measurements

    DEFF Research Database (Denmark)

    Christiansen, Caspar; Stolberg-Rohr, Thomine; Fateev, Alexander

    2016-01-01

    A high temperature and high pressure gas cell (HTPGC) has been manufactured for quantitative spectroscopic measurements in the pressure range 1-200 bar and temperature range 300-1300 K. In the present work the cell was employed at up to 100 bar and 1000 K, and measured absorption coefficients...... of a CO2-N2 mixture at 100 bar and 1000 K are revealed for the first time, exceeding the high temperature and pressure combinations previously reported. This paper discusses the design considerations involved in the construction of the cell and presents validation measurements compared against simulated...

  5. Method and alloys for fabricating wrought components for high-temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Thompson, L.D.; Johnson, W.R.

    1983-01-01

    Wrought, nickel-based alloys, suitable for components of a high-temperature gas-cooled reactor exhibit strength and excellent resistance to carburization at elevated temperatures and include aluminum and titanium in amounts and ratios to promote the growth of carburization resistant films while preserving the wrought character of the alloys. These alloys also include substantial amounts of molybdenum and/or tungsten as solid-solution strengtheners. Chromium may be included in concentrations less than 10% to assist in fabrication. Minor amounts of carbon and one or more carbide-forming metals also contribute to high-temperature strength. The range of compositions of these alloys is given. (author)

  6. Recent progress on gas tungsten arc welding of vanadium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Grossbeck, M.L.; King, J.F.; Alexander, D.J. [Oak Ridge National Lab., TN (United States)] [and others

    1997-08-01

    Emphasis has been placed on welding 6.4 mm plate, primarily by gas tungsten arc (GTA) welding. The weld properties were tested using blunt notch Charpy testing to determine the ductile to brittle transition temperature (DBTT). Erratic results were attributed to hydrogen and oxygen contamination of the welds. An improved gas clean-up system was installed on the welding glove box and the resulting high purity welds had Charpy impact properties similar to those of electron beam welds with similar grain size. A post-weld heat treatment (PWHT) of 950{degrees}C for two hours did not improve the properties of the weld in cases where low concentrations of impurities were attained. Further improvements in the gas clean-up system are needed to control hydrogen contamination.

  7. Highly selective room temperature NO2 gas sensor based on rGO-ZnO composite

    Science.gov (United States)

    Jyoti, Kanaujiya, Neha; Varma, G. D.

    2018-05-01

    Blending metal oxide nanoparticles with graphene or its derivatives can greatly enhance gas sensing characteristics. In the present work, ZnO nanoparticles have been synthesized via reflux method. Thin films of reduced graphene oxide (rGO) and composite of rGO-ZnO have been fabricated by drop casting method for gas sensing application. The samples have been characterized by X-ray diffraction (XRD) and Field-emission scanning electron microscope (FESEM) for the structural and morphological studies respectively. Sensing measurements have been carried out for the composite film of rGO-ZnO for different concentrations of NO2 ranging from 4 to 100 ppm. Effect of increasing temperature on the sensing performance has also been studied and the rGO-ZnO composite sensor shows maximum percentage response at room temperature. The limit of detection (LOD) for rGO-ZnO composite sensor is 4ppm and it exhibits a high response of 48.4% for 40 ppm NO2 at room temperature. To check the selectivity of the composite sensor, sensor film has been exposed to 40 ppm different gases like CO, NH3, H2S and Cl2 at room temperature and the sensor respond negligibly to these gases. The present work suggests that rGO-ZnO composite material can be a better candidate for fabrication of highly selective room temperature NO2 gas sensor.

  8. High-Temperature Structural Analysis Model of the Process Heat Exchanger for Helium Gas Loop (II)

    International Nuclear Information System (INIS)

    Song, Kee Nam; Lee, Heong Yeon; Kim, Chan Soo; Hong, Seong Duk; Park, Hong Yoon

    2010-01-01

    PHE (Process Heat Exchanger) is a key component required to transfer heat energy of 950 .deg. C generated in a VHTR (Very High Temperature Reactor) to the chemical reaction that yields a large quantity of hydrogen. Korea Atomic Energy Research Institute established the helium gas loop for the performance test of components, which are used in the VHTR, and they manufactured a PHE prototype to be tested in the loop. In this study, as part of the high temperature structural-integrity evaluation of the PHE prototype, which is scheduled to be tested in the helium gas loop, we carried out high-temperature structural-analysis modeling, thermal analysis, and thermal expansion analysis of the PHE prototype. The results obtained in this study will be used to design the performance test setup for the PHE prototype

  9. Low-temperature behaviour of an ideal Bose gas and some forbidden thermodynamic cycles

    International Nuclear Information System (INIS)

    Chen Jincan; Lin Bihong

    2003-01-01

    Based on the equation of state of an ideal Bose gas, the heat capacities at constant volume and constant pressure of the Bose system are derived and used to analyse the low-temperature behaviour of the Bose system. It is expounded that some important thermodynamic processes such as a constant pressure and an adiabatic process cannot be carried out from the region of T > T c to that of T c , where T c is the critical temperature of Bose-Einstein condensation of the Bose system. Consequently, some typical thermodynamic cycles such as the Carnot cycle, Brayton cycle, Otto cycle, Ericsson cycle, Diesel cycle and Atkinson cycle cannot be operated across the critical temperature T c of Bose-Einstein condensation of an ideal Bose gas

  10. Microstructure and Hardness of High Temperature Gas Nitrided AISI 420 Martensitic Stainless Steel

    Directory of Open Access Journals (Sweden)

    Ibrahim Nor Nurulhuda Md.

    2014-07-01

    Full Text Available This study examined the microstructure and hardness of as-received and nitrided AISI 420 martensitic stainless steels. High temperature gas nitriding was employed to treat the steels at 1200°C for one hour and four hours using nitrogen gas, followed by furnace cooled. Chromium nitride and iron nitride were formed and concentrated at the outmost surface area of the steels since this region contained the highest concentration of nitrogen. The grain size enlarged at the interior region of the nitrided steels due to nitriding at temperature above the recrystallization temperature of the steel and followed by slow cooling. The nitrided steels produced higher surface hardness compared to as-received steel due to the presence of nitrogen and the precipitation of nitrides. Harder steel was produced when nitriding at four hours compared to one hour since more nitrogen permeated into the steel.

  11. Numerical investigation of high temperature synthesis gas premixed combustion via ANSYS Fluent

    Directory of Open Access Journals (Sweden)

    Pashchenko Dmitry

    2018-01-01

    Full Text Available A numerical model of the synthesis gas pre-mixed combustion is developed. The research was carried out via ANSYS Fluent software. Verification of the numerical results was carried out using experimental data. A visual comparison of the flame contours that obtained by the synthesis gas combustion for Re = 600; 800; 1000 was performed. A comparison of the wall temperature of the combustion chamber, obtained with the help of the developed model, with the results of a physical experiment was also presented. For all cases, good convergence of the results is observed. It is established that a change in the temperature of the syngas/air mixture at the inlet to the combustion chamber does not significantly affect the temperature of the combustion products due to the dissipation of the H2O and CO2 molecules. The obtained results are of practical importance for the design of heat engineering plants with thermochemical heat recovery.

  12. A Mathematical Model for the Exhaust Gas Temperature Profile of a Diesel Engine

    Science.gov (United States)

    Brito, C. H. G.; Maia, C. B.; Sodré, J. R.

    2015-09-01

    This work presents a heat transfer model for the exhaust gas of a diesel power generator to determine the gas temperature profile in the exhaust pipe. The numerical methodology to solve the mathematical model was developed using a finite difference method approach for energy equation resolution and determination of temperature profiles considering turbulent fluid flow and variable fluid properties. The simulation was carried out for engine operation under loads from 0 kW to 40 kW. The model was compared with results obtained using the multidimensional Ansys CFX software, which was applied to solve the governor equations of turbulent fluid flow. The results for the temperature profiles in the exhaust pipe show a good proximity between the mathematical model developed and the multidimensional software.

  13. Hydrogen production from biomass pyrolysis gas via high temperature steam reforming process

    International Nuclear Information System (INIS)

    Wongchang, Thawatchai; Patumsawad, Suthum

    2010-01-01

    Full text: The aim of this work has been undertaken as part of the design of continuous hydrogen production using the high temperature steam reforming process. The steady-state test condition was carried out using syngas from biomass pyrolysis, whilst operating at high temperatures between 600 and 1200 degree Celsius. The main reformer operating parameters (e.g. temperature, resident time and steam to biomass ratio (S/B)) have been examined in order to optimize the performance of the reformer. The operating temperature is a key factor in determining the extent to which hydrogen production is increased at higher temperatures (900 -1200 degree Celsius) whilst maintaining the same as resident time and S/B ratio. The effects of exhaust gas composition on heating value were also investigated. The steam reforming process produced methane (CH 4 ) and ethylene (C 2 H 4 ) between 600 to 800 degree Celsius and enhanced production ethane (C 2 H 6 ) at 700 degree Celsius. However carbon monoxide (CO) emission was slightly increased for higher temperatures all conditions. The results show that the use of biomass pyrolysis gas can produce higher hydrogen production from high temperature steam reforming. In addition the increasing reformer efficiency needs to be optimized for different operating conditions. (author)

  14. Analysis Of Temperature Effects On Reactivity Of The Rsg-Gas Core Using Silicide Fuels

    International Nuclear Information System (INIS)

    Surbakti, Tukiran; Pinem, Surian

    2001-01-01

    RSG-GAS has been operating using new silicide fuels so that it is necessary to estimate and to measure the effect of temperature on reactivity of the core. The parameters to be determined due to temperature effect are reactivity coefficient of moderator temperature, temperature coefficient of fuel element and power reactivity coefficient. By doing a couple compensation method, determination of reactivity coefficient as well as the reactivity coefficient of moderator temperature can be obtained. Furthermore, coefficient of the reactivity was successfully estimated using the combination of WIMS-D4 and Batan-2DIFF. The cell calculation was done by using WIMS-D4 code to get macroscopic cross section and Batan-2DIFF code is used for core calculation. The calculation and experimental results of reactivity coefficient do not show any deviation from RSG-GAS safety margin. The results are -2,84 sen/ o C, -1,29 sen/MW and -0,64 sen/ o C for reactivity coefficients of temperature, power, fuel element and moderator temperature, respectively. All of 3 parameters are absolutely met with safety criteria

  15. Compressibility, zero sound, and effective mass of a fermionic dipolar gas at finite temperature

    International Nuclear Information System (INIS)

    Kestner, J. P.; Das Sarma, S.

    2010-01-01

    The compressibility, zero-sound dispersion, and effective mass of a gas of fermionic dipolar molecules is calculated at finite temperature for one-, two-, and three-dimensional uniform systems, and in a multilayer quasi-two-dimensional system. The compressibility is nonmonotonic in the reduced temperature, T/T F , exhibiting a maximum at finite temperature. This effect might be visible in a quasi-low-dimensional experiment, providing a clear signature of the onset of many-body quantum degeneracy effects. The collective mode dispersion and effective mass show similar nontrivial temperature and density dependence. In a quasi-low-dimensional system, the zero-sound mode may propagate at experimentally attainable temperatures.

  16. Total dissolved gas, barometric pressure, and water temperature data, lower Columbia River, Oregon and Washington, 1996

    Science.gov (United States)

    Tanner, Dwight Q.; Harrison, Howard E.; McKenzie, Stuart W.

    1996-01-01

    Increased levels of total dissolved gas pressure can cause gas-bubble trauma in fish downstream from dams on the Columbia River. In cooperation with the U.S. Army Corps of Engineers, the U.S. Geological Survey collected data on total dissolved gas pressure, barometric pressure, water temperature, and dissolved oxygen pressure at 11 stations on the lower Columbia River from the John Day forebay (river mile 215.6) to Wauna Mill (river mile 41.9) from March to September 1996. Methods of data collection, review, and processing are described in this report. Summaries of daily minimum, maximum, and mean hourly values are presented for total dissolved gas pressure, barometric pressure, and water temperature. Hourly values for these parameters are presented graphically. Dissolved oxygen data are not presented in this report because the quality-control data show that the data have poor precision and high bias. Suggested changes to monitoring procedures for future studies include (1) improved calibration procedures for total dissolved gas and dissolved oxygen to better define accuracy at elevated levels of supersaturation and (2) equipping dissolved oxygen sensors with stirrers because river velocities at the shoreline monitoring stations probably cannot maintain an adequate flow of water across the membrane surface of the dissolved oxygen sensor.

  17. Temperature impact on SO2 removal efficiency by ammonia gas scrubbing

    International Nuclear Information System (INIS)

    He Boshu; Zheng Xianyu; Wen Yan; Tong Huiling; Chen Meiqian; Chen Changhe

    2003-01-01

    Emissions reduction in industrial processes, i.e. clean production, is an essential requirement for sustainable development. Fossil fuel combustion is the main emission source for gas pollutants, such as NO X , SO 2 and CO 2 , and coal is now a primary energy source used worldwide with coal combustion being the greatest atmospheric pollution source in China. This paper analyzes flue gas cleaning by ammonia scrubbing (FGCAS) for power plants to remove gaseous pollutants, such as NO X , SO 2 and CO 2 , and presents the conceptual zero emission design for power plants. The byproducts from the FGCAS process can be used in agriculture or for gas recovery. Experimental results presented for SO 2 removal from the simulated flue gas in a continuous flow experiment, which was similar to an actual flue gas system, showed that the effectiveness of the ammonia injection or scrubbing depends on the temperature. The FGCAS process can effectively remove SO 2 , but the process temperature should be below 60 deg. C or above 80 deg. C for SO 2 reduction by NH 3 scrubbing

  18. Application of a vortex shedding flowmeter to the wide range measurement of high temperature gas flow

    International Nuclear Information System (INIS)

    Baker, S.P.; Ennis, R.M. Jr.; Herndon, P.G.

    1981-01-01

    A single flowmeter was required for helium gas measurement in a Gas Cooled Fast Breeder Reactor loss of coolant simulator. Volumetric flow accuracy of +-1.0% of reading was required over the Reynolds Number range 6 x 10 3 to 1 x 10 6 at flowing pressures from 0.2 to 9 MPa (29 to 1305 psia) at 350 0 C (660 0 F) flowing temperature. Because of its inherent accuracy and rangeability, a vortex shedding flowmeter was selected and specially modified to provide for a remoted thermal sensor. Experiments were conducted to determine the relationship between signal attenuation and sensor remoting geometry, as well as the relationship between gas flow parameters and remoted thermal sensor signal for both compressed air and helium gas. Based upon the results of these experiments, the sensor remoting geometry was optimized for this application. The resultant volumetric flow rangeability was 155:1. The associated temperature increase at the sensor position was 9 0 C above ambient (25 0 F) at a flowing temperature of 350 0 C. The volumetric flow accuracy was measured over the entire 155:1 flow range at parametric values of flowing density. A volumetric flow accuracy of +- % of reading was demonstrated

  19. The Coupling Effect Research of Ash Deposition and Condensation in Low Temperature Flue Gas

    Directory of Open Access Journals (Sweden)

    Lei Ma

    2016-01-01

    Full Text Available Ash deposition is a key factor that deteriorates the heat transfer performance and leads to higher energy consumption of low pressure economizer working in low temperature flue gas. In order to study the ash deposition of heat exchange tubes in low temperature flue gas, two experiments are carried out with different types of heat exchange tubes in different flue gas environments. In this paper, Nusselt Number Nu and fouling factor ε are calculated to describe the heat transfer characteristics so as to study the ash deposition condition. The scanning electron microscope (SEM is used for the analysis of ash samples obtained from the outer wall of heat exchange tubes. The dynamic process of ash deposition is studied under different temperatures of outer wall. The results showed that ash deposition of heat exchanger will achieve a stable state in constant flue gas environment. According to the condition of condensation of acid vapor and water vapor, the process of ash deposition can be distinguished as mere ash deposition, acid-ash coupling deposition, and acid-water-ash coupling deposition.

  20. The dynamic characteristics of HTGR (High Temperature Gas Cooled Reactor) system, (2)

    International Nuclear Information System (INIS)

    Kudo, Kazuhiko; Ohta, Masao; Kawasaki, Hidenori

    1979-01-01

    The dynamic characteristics of a HTGR plant, which has two cooling loops, was investigated. The analytical model consists of the core with fuel sleeves, coolant channels and blocks, the upper and lower reflectors, the high and low temperature plenums, two double wall pipings, two intermediate heat exchangers and the secondary system. The key plant parameters for calculation were as follows: the core outlet gas temperature 1000 deg C, the reactor thermal output 50 MW, the flow rate of primary coolant gas 7.96 kg/sec-loop and the pressure of primary coolant gas 40 kg/cm 2 at the rated operating condition. The calculating parameters were fixed as follows: the time interval for core characteristic analysis 0.1 sec, the time interval for thermal characteristic analysis 5.0 sec, the number of division of fuel channels 130, and the number of division of an intermediate heat exchanger 200. The assumptions for making the model were evaluated especially for the power distribution in the core and the heat transmission coefficients in the core, the double wall piping and the intermediate heat exchangers. Concerning the analytical results, the self-control to the outer disturbance of reactivity and the plant dynamic behavior due to the change of flow rate of primary and secondary coolants, and the change of gas temperature of secondary coolant at the inlet of intermediate heat exchangers, are presented. (Nakai, Y.)

  1. Gas Turbine High Temperature Gas (Helium) Reactor Using Pebble Bed Fuel Derived from Spent Fuel

    International Nuclear Information System (INIS)

    Cole, Quentin

    2013-01-01

    Project goals: Build on the $1B investment spent during the NGNP Project for the only true Inherently Safe Small Modular Reactor Design – the only SMR design that can make this claim due to negative temperature coefficient of reactivity - no containment required – less construction cost. NPMC in Partnership with Pebble Bed Modular Group, a fully owned subsidiary of Eskom, RSA to Factory Build Complete Plant in Modular Sections at Factory Site in Oswego, NY for transport to site by rail or shipping for world wide export. NPMC will provide Project and Construction Management of all new builds from plant sites through construction, commissioning and startup using local labor. License and Construct ion of spent fuel processing facility in both NY and South Africa using Proven Technology. Ultimate goals of project: 1. Award of the 2013 US DOE Innovative SMR $452M cost share grant for US NRC License Certification 2.Build Full Scale Demonstration Plant at Koeburg, RSA with World Bank Funding managed by NPMC in collaboration with our legal firm, Haynes and Boone LLP 3. Take Plant Orders Immediately (10% Down Payment) 4. Form Strategic Alliance with Domestic and/or International Utility

  2. A study on different thermodynamic cycle schemes coupled with a high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Qu, Xinhe; Yang, Xiaoyong; Wang, Jie

    2017-01-01

    Highlights: • The features of three different power generation schemes, including closed Brayton cycle, non-reheating combined cycle and reheating combined cycle, coupled with high temperature gas-cooled reactor (HTGR) were investigated and compared. • The effects and mechanism of reactor core outlet temperature, compression ratio and other key parameters over cycle characteristics were analyzed by the thermodynamic models.. • It is found that reheated combined cycle has the highest efficiency. Reactor outlet temperature and main steam parameters are key factors to improve the cycle’s performance. - Abstract: With gradual increase in reactor outlet temperature, the efficient power conversion technology has become one of developing trends of (very) high temperature gas-cooled reactors (HTGRs). In this paper, different cycle power generation schemes for HTGRs were systematically studied. Physical and mathematical models were established for these three cycle schemes: closed Brayton cycle, simple combined cycle, and reheated combined cycle. The effects and mechanism of key parameters such as reactor core outlet temperature, reactor core inlet temperature and compression ratio on the features of these cycles were analyzed. Then, optimization results were given with engineering restrictive conditions, including pinch point temperature differences. Results revealed that within the temperature range of HTGRs (700–900 °C), the reheated combined cycle had the highest efficiency, while the simple combined cycle had the lowest efficiency (900 °C). The efficiencies of the closed Brayton cycle, simple combined cycle and reheated combined cycle are 49.5%, 46.6% and 50.1%, respectively. These results provide insights on the different schemes of these cycles, and reveal the effects of key parameters on performance of these cycles. It could be helpful to understand and develop a combined cycle coupled with a high temperature reactor in the future.

  3. Metathesis in the generation of low-temperature gas in marine shales

    Directory of Open Access Journals (Sweden)

    Jarvie Daniel M

    2010-01-01

    Full Text Available Abstract The recent report of low-temperature catalytic gas from marine shales took on additional significance with the subsequent disclosure of natural gas and low-temperature gas at or near thermodynamic equilibrium in methane, ethane, and propane. It is important because thermal cracking, the presumed source of natural gas, cannot generate these hydrocarbons at equilibrium nor can it bring them to equilibrium over geologic time. The source of equilibrium and the source of natural gas are either the same (generation under equilibrium control or closely associated. Here we report the catalytic interconversion of hydrocarbons (metathesis as the source of equilibrium in experiments with Cretaceous Mowry shale at 100°C. Focus was on two metathetic equilibria: methane, ethane, and propane, reported earlier, Q (K = [(C1*(C3]/[(C22], and between these hydrocarbons and n-butane, Q* (K = [(C1*(n-C4]/[(C2*(C3], reported here for the first time. Two observations stand out. Initial hydrocarbon products are near equilibrium and have maximum average molecular weights (AMW. Over time, products fall from equilibrium and AMW in concert. It is consistent with metathesis splitting olefin intermediates [Cn] to smaller intermediates (fission as gas generation creates open catalytic sites ([ ]: [Cn] + [ ] → [Cn-m] + [Cm]. Fission rates increasing exponentially with olefin molecular weight could contribute to these effects. AMW would fall over time, and selective fission of [C3] and [n-C4] would draw Q and Q* from equilibrium. The results support metathesis as the source of thermodynamic equilibrium in natural gas.

  4. Effects of atmospheric gas composition and temperature on the gasification of coal in hot briquetting carbon composite iron ore

    Energy Technology Data Exchange (ETDEWEB)

    Ueki, Y.; Kanayama, M.; Maeda, T.; Nishika, K.; Shimizu, M. [Kyushu University, Fukuoka (Japan). Dept. of Materials Science & Engineering

    2007-01-15

    The gasification behavior of carbon composite iron ore produced by hot briquetting process was examined under various gas atmospheres such as CO-N{sub 2}, CO{sub 2}-N, and CO-CO{sub 2} at various temperatures. The gasification of coal was affected strongly by atmospheric gas concentration and reaction temperature. Kinetic analysis in various gas atmospheres was carried out by using the first order reaction model, which yields the straight line relation between reaction rate constants for the gasification of coal and the gas concentration. Therefore, reaction rate constants for the gasification of coal in CO-CO{sub 2}-N{sub 2} gas atmosphere were derived.

  5. Utility industry evaluation of the Modular High-Temperature Gas-Cooled Reactor

    International Nuclear Information System (INIS)

    Burstein, S.; Bitel, J.S.; Tramm, T.R.; High, M.D.; Neils, G.H.; Tomonto, J.R.; Weinberg, C.J.

    1990-02-01

    A team of utility industry representatives evaluated the Modular High Temperature Gas-Cooled Reactor plant design, a current design created by an industrial team led by General Atomics under Department of Energy sponsorship and with support provided by utilities through Gas-Cooled Reactor Associates. The utility industry team concluded that the plant design should be considered a viable application of an advanced nuclear concept and deserves continuing development. Specific comments and recommendations are provided as a contribution toward improving a very promising plant design. 2 refs

  6. Study on fundamental features of helium turbomachine for high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Wang Jie; Gu Yihua

    2004-01-01

    The High temperature gas-cooled reactor (HTGR) coupled with helium turbine cycle is considered as one of the leading candidates for future nuclear power plants. The HTGR helium turbine cycle was analyzed and optimized. Then the focal point of investigation was concentrated on the fundamental thermodynamic and aerodynamic features of helium turbomachine. As a result, a helium turbomachine is different from a general combustion gas turbine in two main design features, that is a helium turbomachine has more blade stages and shorter blade length, which are caused by the helium property and the high pressure of a closed cycle, respectively. (authors)

  7. Ideal Gas with a Varying (Negative Absolute) Temperature: an Alternative to Dark Energy?

    Science.gov (United States)

    Saha, Subhajit; Mondal, Anindita; Corda, Christian

    2018-02-01

    The present work is an attempt to investigate whether the evolutionary history of the Universe from the offset of inflation can be described by assuming the cosmic fluid to be an ideal gas with a specific gas constant but a varying negative absolute temperature (NAT). The motivation of this work is to search for an alternative to the "exotic" and "supernatural" dark energy (DE). In fact, the NAT works as an "effective quintessence" and there is need to deal neither with exotic matter like DE nor with modified gravity theories. For the sake of completeness, we release some clarifications on NATs in Section 3 of the paper.

  8. Evaluation of proposed German safety criteria for high-temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Barsell, A.W.

    1980-05-01

    This work reviews proposed safety criteria prepared by the German Bundesministerium des Innern (BMI) for future licensing of gas-cooled high-temperature reactor (HTR) concepts in the Federal Republic of Germany. Comparison is made with US General Design Criteria (GDCs) in 10CFR50 Appendix A and with German light water reactor (LWR) criteria. Implications for the HTR design relative to the US design and safety approach are indicated. Both inherent characteristics and design features of the steam cycle, gas turbine, and process heat concepts are taken into account as well as generic design options such as a pebble bed or prismatic core

  9. Conceptual Design for a High-Temperature Gas Loop Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    James B. Kesseli

    2006-08-01

    This report documents an early-stage conceptual design for a high-temperature gas test loop. The objectives accomplished by the study include, (1) investigation of existing gas test loops to determine ther capabilities and how the proposed system might best complement them, (2) development of a preliminary test plan to help identify the performance characteristics required of the test unit, (3) development of test loop requirements, (4) development of a conceptual design including process flow sheet, mechanical layout, and equipment specifications and costs, and (5) development of a preliminary test loop safety plan.

  10. Influence of dissolved gas and temperature on the light yield of new liquid scintillators

    CERN Document Server

    Buontempo, S; Golovkin, S V; Martellotti, G; Medvedkov, A M; Penso, G; Soloviev, A S; Vasilchenko, V G

    1999-01-01

    Sixteen new liquid scintillators, emitting green light, were studied. They are based on four solvents combined with four dopants. The influence of different gas atmospheres was studied. In particular it was shown that by keeping these liquid scintillators in vacuum or in a neutral gas, the light yield increases up to 32~\\% at 20 $^{\\circ}$C and for the best solvent-dopant combinations. The dependance of the light yield on temperature was also studied for these scintillators. In the 20--60 $^{\\circ}$C interval, some exhibit a light yield variation of $\\sim$ 3 \\% which is smaller than that of the NE 102A plastic scintillator.

  11. The self limiting effect of hydrogen cluster in gas jet under liquid nitrogen temperature

    International Nuclear Information System (INIS)

    Han Jifeng; Yang Chaowen; Miao Jingwei; Fu Pengtao; Luo Xiaobing; Shi Miangong

    2010-01-01

    The generation of hydrogen clusters in gas jet is tested using the Rayleigh scattering method under liquid nitrogen temperature of 79 K. The self limiting effect of hydrogen cluster is studied and it is found that the cluster formation is greatly affected by the number of expanded molecules. The well designed liquid nitrogen cold trap ensured that the hydrogen cluster would keep maximum size for maximum 15 ms during one gas jet. The scattered light intensity exhibits a power scaling on the backing pressure ranging from 5 to 48 bar with the power value of 4.1.

  12. Tunable Diode Laser Sensors to Monitor Temperature and Gas Composition in High-Temperature Coal Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, Ronald [Stanford Univ., CA (United States); Whitty, Kevin [Univ. of Utah, Salt Lake City, UT (United States)

    2014-12-01

    The integrated gasification combined cycle (IGCC) when combined with carbon capture and storage can be one of the cleanest methods of extracting energy from coal. Control of coal and biomass gasification processes to accommodate the changing character of input-fuel streams is required for practical implementation of integrated gasification combined-cycle (IGCC) technologies. Therefore a fast time-response sensor is needed for real-time monitoring of the composition and ideally the heating value of the synthesis gas (here called syngas) as it exits the gasifier. The goal of this project was the design, construction, and demonstration an in situ laserabsorption sensor to monitor multiple species in the syngas output from practical-scale coal gasifiers. This project investigated the hypothesis of using laser absorption sensing in particulateladen syngas. Absorption transitions were selected with design rules to optimize signal strength while minimizing interference from other species. Successful in situ measurements in the dusty, high-pressure syngas flow were enabled by Stanford’s normalized and scanned wavelength modulation strategy. A prototype sensor for CO, CH4, CO2, and H2O was refined with experiments conducted in the laboratory at Stanford University, a pilot-scale at the University of Utah, and an engineering-scale gasifier at DoE’s National Center for Carbon Capture with the demonstration of a prototype sensor with technical readiness level 6 in the 2014 measurement campaign.

  13. State of development of high temperature gas-cooled reactors in foreign countries

    International Nuclear Information System (INIS)

    Sudo, Yukio

    1990-01-01

    Emphasis has been placed in the development of high temperature gas-cooled reactors on high thermal efficiency as power reactors and the reactor from which nuclear heat can be utilized. In U.K., as the international project 'Dragon Project', the experimental Dragon reactor for research use with 20 MWt output and exit coolant temperature 750 deg C was constructed, and operated till 1976. Coated fuel particles were developed. In West Germany, the experimental power reactor AVR with 46 MWt and 15 MWe output was operated till 1988. The prototype power reactor THTR-300 with 300 MWe output and 750 deg C exit temperature is in commercial operation. In USA, the experimental power reactor Peach Bottom reactor with 40 MWe output and 728 deg C exit temperature was operated till 1974. The prototype Fort Saint Vrain power reactor with 330 MWe output and 782 deg C exit temperature was operated till 1989. In USSR, the modular VGM with 200 MWh output is at the planning stage. Also in China, high temperature gas-cooled reactors are at the design stage. Switzerland has taken part in various international projects. (K.I.)

  14. Fixed-bed gasifier and cleanup system engineering summary report through Test Run No. 100

    Energy Technology Data Exchange (ETDEWEB)

    Pater, K. Jr.; Headley, L.; Kovach, J.; Stopek, D.

    1984-06-01

    The state-of-the-art of high-pressure, fixed-bed gasification has been advanced by the many refinements developed over the last 5 years. A novel full-flow gas cleanup system has been installed and tested to clean coal-derived gases. This report summarizes the results of tests conducted on the gasifier and cleanup system from its inception through 1982. Selected process summary data are presented along with results from complementary programs in the areas of environmental research, process simulation, analytical methods development, and component testing. 20 references, 32 figures, 42 tables.

  15. Spectrographic temperature measurement of a high power breakdown arc in a high pressure gas switch

    Energy Technology Data Exchange (ETDEWEB)

    Yeckel, Christopher; Curry, Randy [Department of Computer and Electrical Engineering, Center for Physical and Power Electronics, University of Missouri--Columbia, Columbia, Missouri 65211 (United States)

    2011-09-15

    A procedure for obtaining an approximate temperature value of conducting plasma generated during self-break closure of a RIMFIRE gas switch is described. The plasma is in the form of a breakdown arc which conducts approximately 12 kJ of energy in 1 {mu}s. A spectrographic analysis of the trigger-section of the 6-MV RIMFIRE laser triggered gas switch used in Sandia National Laboratory's ''Z-Machine'' has been made. It is assumed that the breakdown plasma has sufficiently approached local thermodynamic equilibrium allowing a black-body temperature model to be applied. This model allows the plasma temperature and radiated power to be approximated. The gas dielectric used in these tests was pressurized SF{sub 6}. The electrode gap is set at 4.59 cm for each test. The electrode material is stainless steel and insulator material is poly(methyl methacrylate). A spectrum range from 220 to 550 nanometers has been observed and calibrated using two spectral irradiance lamps and three spectrograph gratings. The approximate plasma temperature is reported.

  16. Economic analysis of multiple-module high temperature gas-cooled reactor (MHTR) nuclear power plants

    International Nuclear Information System (INIS)

    Liu Yu; Dong Yujie

    2011-01-01

    In recent years, as the increasing demand of energy all over the world, and the pressure on greenhouse emissions, there's a new opportunity for the development of nuclear energy. Modular High Temperature Gas-cooled Reactor (MHTR) received recognition for its inherent safety feature and high outlet temperature. Whether the Modular High Temperature Gas-cooled Reactor would be accepted extensively, its economy is a key point. In this paper, the methods of qualitative analysis and the method of quantitative analysis, the economic models designed by Economic Modeling Working Group (EMWG) of the Generation IV International Forum (GIF), as well as the HTR-PM's main technical features, are used to analyze the economy of the MHTR. A prediction is made on the basis of summarizing High Temperature Gas-cooled Reactor module characteristics, construction cost, total capital cost, fuel cost and operation and maintenance (O and M) cost and so on. In the following part, comparative analysis is taken measures to the economy and cost ratio of different designs, to explore the impacts of modularization and standardization on the construction of multiple-module reactor nuclear power plant. Meanwhile, the analysis is also adopted in the research of key factors such as the learning effect and yield to find out their impacts on the large scale development of MHTR. Furthermore, some reference would be provided to its wide application based on these analysis. (author)

  17. Nuclear power for coexistence with nature, high temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Kaneko, Yoshihiko

    1996-01-01

    Until this century, it is sufficient to aim at the winner of competition in human society to obtain resources, and to entrust waste to natural cleaning action. However, the expansion of social activities has been too fast, and the scale has become too large, consequently, in the next century, the expansion of social activities will be caught by the structure of trilemma that is subjected to the strong restraint and selection from the problems of finite energy and resources and environment preservation. In 21st century, the problems change to those between mankind and nature. Energy supply and population increase, envrionment preservation and human activities, and the matters that human wisdom should bear regarding energy technology are discussed. In Japan, the construction of the high temperature engineering test reactor (HTTR) is in progress. The design of high temperature gas-cooled reactors and their features on the safety are explained. The capability of reducing CO 2 release of high temperature gas-cooled reactors is reported. In future, it is expected that the time of introducing high temperature gas-cooled reactors will come. (K.I.)

  18. Conjugated heat transfer and temperature distributions in a gas turbine combustion liner under base-load operation

    International Nuclear Information System (INIS)

    Kim, Kyung Min; Yun, Nam Geon; Jeon, Yun Heung; Lee, Dong Hyun; Cho, Yung Hee

    2010-01-01

    Prediction of temperature distributions on hot components is important in development of a gas turbine combustion liner. The present study investigated conjugated heat transfer to obtain temperature distributions in a combustion liner with six combustion nozzles. 3D numerical simulations using FVM commercial codes, Fluent and CFX were performed to calculate combustion and heat transfer distributions. The temperature distributions in the combustor liner were calculated by conjugation of conduction and convection (heat transfer coefficients) obtained by combustion and cooling flow analysis. The wall temperature was the highest on the attachment points of the combustion gas from combustion nozzles, but the temperature gradient was high at the after shell section with low wall temperature

  19. High resolution temperature mapping of gas turbine combustor simulator exhaust with femtosecond laser induced fiber Bragg gratings

    Science.gov (United States)

    Walker, Robert B.; Yun, Sangsig; Ding, Huimin; Charbonneau, Michel; Coulas, David; Lu, Ping; Mihailov, Stephen J.; Ramachandran, Nanthan

    2017-04-01

    Femtosecond infrared (fs-IR) laser written fiber Bragg gratings (FBGs), have demonstrated great potential for extreme sensing. Such conditions are inherent in advanced gas turbine engines under development to reduce greenhouse gas emissions; and the ability to measure temperature gradients in these harsh environments is currently limited by the lack of sensors and controls capable of withstanding the high temperature, pressure and corrosive conditions present. This paper discusses fabrication and deployment of several fs-IR written FBG arrays, for monitoring exhaust temperature gradients of a gas turbine combustor simulator. Results include: contour plots of measured temperature gradients, contrast with thermocouple data.

  20. Identifying Liquid-Gas System Misconceptions and Addressing Them Using a Laboratory Exercise on Pressure-Temperature Diagrams of a Mixed Gas Involving Liquid-Vapor Equilibrium

    Science.gov (United States)

    Yoshikawa, Masahiro; Koga, Nobuyoshi

    2016-01-01

    This study focuses on students' understandings of a liquid-gas system with liquid-vapor equilibrium in a closed system using a pressure-temperature ("P-T") diagram. By administrating three assessment questions concerning the "P-T" diagrams of liquid-gas systems to students at the beginning of undergraduate general chemistry…

  1. Effects of flow rate and temperature on cyclic gas exchange in tsetse flies (Diptera, Glossinidae).

    Science.gov (United States)

    Terblanche, John S; Chown, Steven L

    2010-05-01

    Air flow rates may confound the investigation and classification of insect gas exchange patterns. Here we report the effects of flow rates (50, 100, 200, 400 ml min(-1)) on gas exchange patterns in wild-caught Glossina morsitans morsitans from Zambia. At rest, G. m. morsitans generally showed continuous or cyclic gas exchange (CGE) but no evidence of discontinuous gas exchange (DGE). Flow rates had little influence on the ability to detect CGE in tsetse, at least in the present experimental setup and under these laboratory conditions. Importantly, faster flow rates resulted in similar gas exchange patterns to those identified at lower flower rates suggesting that G. m. morsitans did not show DGE which had been incorrectly identified as CGE at lower flow rates. While CGE cycle frequency was significantly different among the four flow rates (prate treatment variation. Using a laboratory colony of closely related, similar-sized G. morsitans centralis we subsequently investigated the effects of temperature, gender and feeding status on CGE pattern variation since these factors can influence insect metabolic rates. At 100 ml min(-1) CGE was typical of G. m. centralis at rest, although it was significantly more common in females than in males (57% vs. 43% of 14 individuals tested per gender). In either sex, temperature (20, 24, 28 and 32 degrees C) had little influence on the number of individuals showing CGE. However, increases in metabolic rate with temperature were modulated largely by increases in burst volume and cycle frequency. This is unusual among insects showing CGE or DGE patterns because increases in metabolic rate are usually modulated by increases in frequency, but either no change or a decline in burst volume. Copyright 2009 Elsevier Ltd. All rights reserved.

  2. Mathematical Simulation of Convective Heat Transfer in the Low-Temperature Storage of Liquefied Natural Gas

    Directory of Open Access Journals (Sweden)

    Shestakov Igor A.

    2015-01-01

    Full Text Available The article shows the results of mathematical modeling of convective heat transfer in the low-temperature storage of liquefied natural gas. Regime of natural convection in an enclosure with different intensity of the heat flux at the external borders are investigated. Was examined two-dimensional nonstationary problem within the model of Navier-Stokes in dimensionless variables “vorticity - stream function - temperature”. Distributions of hydrodynamic parameters and temperatures that characterize the basic regularities of the processes are obtained. Circulating flows are determined and carried out the analysis of vortices formation mechanism and the temperature distribution in solution at conditions of natural convection when the Grashof number (Gr = 106. A significant influence of heat transfer rate on solutions boundary on flow structure and temperature field in LNG storage tanks.

  3. Safety aspects of forced flow cooldown transients in modular high temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Kroeger, P.G.

    1992-01-01

    During some of the design basis accidents in Modular High Temperature Gas Cooled Reactors (MHTGRs) the main Heat Transport System (HTS) and the Shutdown Cooling System (SCS), are assumed to have failed. Decay heat is then removed by the passive Reactor Cavity Cooling System (RCCS) only. If either forced flow cooling system becomes available during such a transient, its restart could significantly reduce the down-time. This paper uses the THATCH code to examine whether such restart, during a period of elevated core temperatures, can be accomplished within safe limits for fuel and metal component temperatures. If the reactor is scrammed, either system can apparently be restarted at any time, without exceeding any safe limits. However, under unscrammed conditions a restart of forced cooling can lead to recriticality, with fuel and metal temperatures significantly exceeding the safety limits

  4. The Kondo temperature of a two-dimensional electron gas with Rashba spin–orbit coupling

    International Nuclear Information System (INIS)

    Chen, Liang; Lin, Hai-Qing; Sun, Jinhua; Tang, Ho-Kin

    2016-01-01

    We use the Hirsch–Fye quantum Monte Carlo method to study the single magnetic impurity problem in a two-dimensional electron gas with Rashba spin–orbit coupling. We calculate the spin susceptibility for various values of spin–orbit coupling, Hubbard interaction, and chemical potential. The Kondo temperatures for different parameters are estimated by fitting the universal curves of spin susceptibility. We find that the Kondo temperature is almost a linear function of Rashba spin–orbit energy when the chemical potential is close to the edge of the conduction band. When the chemical potential is far away from the band edge, the Kondo temperature is independent of the spin–orbit coupling. These results demonstrate that, for single impurity problems in this system, the most important reason to change the Kondo temperature is the divergence of density of states near the band edge, and the divergence is induced by the Rashba spin–orbit coupling. (paper)

  5. RELATION BETWEEN MECHANICAL PROPERTIES AND PYROLYSIS TEMPERATURE OF PHENOL FORMALDEHYDE RESIN FOR GAS SEPARATION MEMBRANES

    Directory of Open Access Journals (Sweden)

    MONIKA ŠUPOVÁ

    2012-03-01

    Full Text Available The aim of this paper has been to characterize the relation between the pyrolysis temperature of phenol-formaldehyde resin, the development of a porous structure, and the mechanical properties for the application of semipermeable membranes for gas separation. No previous study has dealt with this problem in its entirety. Phenol-formaldehyde resin showed an increasing trend toward micropore porosity in the temperature range from 500 till 1000°C, together with closure of mesopores and macropores. Samples cured and pyrolyzed at 1000°C pronounced hysteresis of desorption branch. The ultimate bending strength was measured using a four-point arrangement that is more suitable for measuring of brittle materials. The chevron notch technique was used for determination the fracture toughness. The results for mechanical properties indicated that phenol-formaldehyde resin pyrolyzates behaved similarly to ceramic materials. The data obtained for the material can be used for calculating the technical design of gas separation membranes.

  6. Economical evaluation on gas turbine high temperature reactor 300 (GTHTR300)

    International Nuclear Information System (INIS)

    Takei, Masanobu; Kosugiyama, Shinichi; Mouri, Tomoaki; Katanishi, Shoji; Kunitomi, Kazuhiko

    2006-01-01

    Japan Atomic Energy Research Institute (JAERI) has been developing a graphite moderate and helium cooled High Temperature Gas-cooled Reactor (HTGR) with gas turbine, the GTHTR300 based on experience gained in development and operations of the High Temperature Engineering Test Reactor (HTTR) in JAERI. The GTHTR300 is a simplified and economical power plant with a high level of safety characteristics and a high plant efficiency of approximately 46%. Cost evaluation for plant construction and power generation is studied in order to clarify the economical feasibility of the GTHTR300. The construction cost is estimated to be about 200 thousands Yen/kWe. The power generation cost is estimated to be about 3.8 Yen/kWh by the conditions of 90% load factor and 3% discount rate. The economical feasibility of the GTHTR300 is certified. The present study is entrusted from Ministry of Education, Culture, Sports, Science and Technology of Japan. (author)

  7. Gas sensor based on photoconductive electrospun titania nanofibres operating at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Zampetti, E., E-mail: emiliano.zampetti@artov.imm.cnr.it; Macagnano, A.; Bearzotti, A. [Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi (CNR IMM) (Italy)

    2013-04-15

    An important drawback of semiconductor gas sensors is their operating temperature that needs the use of heaters. To overcome this problem a prototyping sensor using titania nanofibres (with an average diameter of 50 nm) as sensitive membrane were fabricated by electrospinning directly on the transducer of the sensor. Exploiting the effect of titania photoconductivity, resistance variations upon gas interaction under continuous irradiation of ultra violet light were measured at room temperature. The resistive sensor response was evaluated towards ammonia, nitrogen dioxide and humidity. The sensor exhibited a higher response to ammonia than to nitrogen dioxide, especially for concentrations larger than 100 ppb. For 200 ppb of ammonia and nitrogen dioxide, the responses were {approx}2.8 and 1.5 %, respectively.

  8. Porous nuclear fuel element with internal skeleton for high-temperature gas-cooled nuclear reactors

    Science.gov (United States)

    Youchison, Dennis L.; Williams, Brian E.; Benander, Robert E.

    2013-09-03

    Porous nuclear fuel elements for use in advanced high temperature gas-cooled nuclear reactors (HTGR's), and to processes for fabricating them. Advanced uranium bi-carbide, uranium tri-carbide and uranium carbonitride nuclear fuels can be used. These fuels have high melting temperatures, high thermal conductivity, and high resistance to erosion by hot hydrogen gas. Tri-carbide fuels, such as (U,Zr,Nb)C, can be fabricated using chemical vapor infiltration (CVI) to simultaneously deposit each of the three separate carbides, e.g., UC, ZrC, and NbC in a single CVI step. By using CVI, the nuclear fuel may be deposited inside of a highly porous skeletal structure made of, for example, reticulated vitreous carbon foam.

  9. Porous nuclear fuel element for high-temperature gas-cooled nuclear reactors

    Science.gov (United States)

    Youchison, Dennis L [Albuquerque, NM; Williams, Brian E [Pacoima, CA; Benander, Robert E [Pacoima, CA

    2011-03-01

    Porous nuclear fuel elements for use in advanced high temperature gas-cooled nuclear reactors (HTGR's), and to processes for fabricating them. Advanced uranium bi-carbide, uranium tri-carbide and uranium carbonitride nuclear fuels can be used. These fuels have high melting temperatures, high thermal conductivity, and high resistance to erosion by hot hydrogen gas. Tri-carbide fuels, such as (U,Zr,Nb)C, can be fabricated using chemical vapor infiltration (CVI) to simultaneously deposit each of the three separate carbides, e.g., UC, ZrC, and NbC in a single CVI step. By using CVI, the nuclear fuel may be deposited inside of a highly porous skeletal structure made of, for example, reticulated vitreous carbon foam.

  10. The Preliminary Study of High Temperature Gas Cooled Reactors (HTGRs) Technology

    International Nuclear Information System (INIS)

    Nurfarhana Ayuni Joha; Izhar Abu Hussin; Ridzuan Abdul Mutalib

    2015-01-01

    High Temperature Gas Cooled Reactors (HTGRs) have attracted worldwide interest because of their high outlet temperatures, which allow them to be used for applications beyond electricity generation. HTGRs have been built and operated since as far back as the 1970s. Experimental and demonstration reactors of this type have operated in China, Great Britain, Germany, Japan, and the United States of America. This paper is written to share the valuable knowledge and information of HTGRs technology as a mean to enrich peoples understanding of the technology. This paper will present the technological features of HTGRs that allow for a modular design with inherently safe characteristics. (author)

  11. Increasing the efficiency of heating systems by reducing the flue gas temperature below the dew point

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, H.

    1981-06-01

    This paper deals with the fundamentals and technical possibilities of increasing the combustion efficiency of gas-fired heating units for domestic heating by cooling the flue gases below their water vapor saturation temperature. The improvement of the efficiency can be more than 15% in comparison even to modern warm water heating boilers. Important however is the availability of cooling fluids of sufficiently low temperatures which could be recirculated heating water, freshwater and air. Different possible applications of this method are discussed in detail.

  12. The passive safety characteristics of modular high temperature gas-cooled reactor fuel elements

    International Nuclear Information System (INIS)

    Goodin, D.T.; Kania, M.J.; Nabielek, H.; Schenk, W.; Verfondern, K.

    1988-01-01

    High-Temperature Gas-Cooled Reactors (HTGR) in both the US and West Germany use an all-ceramic, coated fuel particle to retain fission products. Data from irradiation, postirradiation examinations and postirradiation heating experiments are used to study the performance capabilities of the fuel particles. The experimental results from fission product release tests with HTGR fuel are discussed. These data are used for development of predictive fuel performance models for purposes of design, licensing, and risk analyses. During off normal events, where temperatures may reach up to 1600/degree/C, the data show that no significant radionuclide releases from the fuel will occur

  13. Krypton separation from waste gas of a reprocessing plant by low temperature rectification

    International Nuclear Information System (INIS)

    1987-01-01

    6 lectures at this seminar describe and evaluate the results of the research and development work on low temperature krypton separation from the waste gas of the reprocessing of nuclear fuels. They are used for making decisions for the process to be used in the future on a large scale at the Wackersdorf reprocessing plant. 2 further lectures deal with alternatives to this process, which were also developed: the freon washing and low temperature adsorption of krypton. All the lectures were included separately in the INIS and ENERGY databases. (RB) [de

  14. Study of flue-gas temperature difference in supercritical once-through boiler

    Science.gov (United States)

    Kang, Yanchang; Li, Bing; Song, Ang

    2018-02-01

    The 600 MW coal-fired once-through Boilers with opposed firing at a power plant are found to experience marked temperature variation and even overtemperature on the wall of the heating surface as a result of flue-gas temperature (FGT) variation in the boiler. In this study, operational adjustments were made to the pulverizing, combustion, and secondary air box systems in these boilers, in order to solve problems in internal combustion. The adjustments were found to reduce FGT difference and optimize the boiler’ combustion conditions. The results of this study can provide a reference for optimization of coal-fired boiler of the same type in similar conditions.

  15. γ-irradiation induced zinc ferrites and their enhanced room-temperature ammonia gas sensing properties

    Science.gov (United States)

    Raut, S. D.; Awasarmol, V. V.; Ghule, B. G.; Shaikh, S. F.; Gore, S. K.; Sharma, R. P.; Pawar, P. P.; Mane, R. S.

    2018-03-01

    Zinc ferrite (ZnFe2O4) nanoparticles (NPs), synthesized using a facile and cost-effective sol-gel auto-combustion method, were irradiated with 2 and 5 kGy γ-doses using 60Co as a radioactive source. Effect of γ-irradiation on the structure, morphology, pore-size and pore-volume and room-temperature (300 K) gas sensor performance has been measured and reported. Both as-synthesized and γ-irradiated ZnFe2O4 NPs reveal remarkable gas sensor activity to ammonia in contrast to methanol, ethanol, acetone and toluene volatile organic gases. The responses of pristine, 2 and 5 kGy γ-irradiated ZnFe2O4 NPs are respectively 55%, 66% and 81% @100 ppm concentration of ammonia, signifying an importance of γ-irradiation for enhancing the sensitivity, selectivity and stability of ZnFe2O4 NPs as ammonia gas sensors. Thereby, due to increase in surface area and crystallinity on γ-doses, the γ-irradiation improves the room-temperature ammonia gas sensing performance of ZnFe2O4.

  16. Basic design and economical evaluation of Gas Turbine High Temperature Reactor 300 (GTHTR300)

    International Nuclear Information System (INIS)

    Kazuhiko, Kunitomi; Shusaku, Shiozawa; Xing, Yan

    2007-01-01

    High Temperature Gas-cooled Reactor (HTGR) combined with a direct cycle gas turbine offers one of the most promising nuclear electricity generation options after 2010. Japan Atomic Energy Agency has been engaging in the basic design and development of Gas Turbine High Temperature Reactor 300 (GTHTR300) since 2003. Costs of capital, fuel, and operation and maintenance have been estimated. The capital cost of the GTHTR300 is lower than that of the existing light water reactor (LWR) because the generation efficiency is considerably higher whereas the construction cost is lower owing to the design simplicity of the gas turbine power conversion unit and the reactor safety system. The fuel cost is shown to equal that of LWR. The operation and maintenance cost has a slight advantage due to the use of chemically inert helium coolant. In sum, the cost of electricity for the GTHTR300 is estimated to be below US 3.3 cents/kWh (4 yen/kWh), which is about two-third of that of current LWRs in Japan. The results confirm that the net power generation cost of the GTHTR300 is much lower than that of the LWR, indicating that the GTHTR300 plant consisting of small-scale reactor units can be economically competitive to the latest large-scale LWR. (authors)

  17. The modular high-temperature gas-cooled reactor: A cost/risk competitive nuclear option

    International Nuclear Information System (INIS)

    Gotschall, H.L.

    1994-01-01

    The business risks of nuclear plant ownership are identified as a constraint on the expanded use of nuclear power. Such risks stem from the exacting demands placed on owner/operator organizations of current plants to demonstrate ongoing compliance with safety regulations and the resulting high costs for operation and maintenance. This paper describes the Modular High-Temperature Gas-Cooled Reactor (MHTGR) design, competitive economics, and approach to reducing the business risks of nuclear plant ownership

  18. Reference modular High Temperature Gas-Cooled Reactor Plant: Concept description report

    Energy Technology Data Exchange (ETDEWEB)

    1986-10-01

    This report provides a summary description of the Modular High Temperature Gas-Cooled Reactor (MHTGR) concept and interim results of assessments of costs, safety, constructibility, operability, maintainability, and availability. Conceptual design of this concept was initiated in October 1985 and is scheduled for completion in 1987. Participating industrial contractors are Bechtel National, Inc. (BNI), Stone and Webster Engineering Corporation (SWEC), GA Technologies, Inc. (GA), General Electric Co. (GE), and Combustion Engineering, Inc. (C-E).

  19. Reference modular High Temperature Gas-Cooled Reactor Plant: Concept description report

    International Nuclear Information System (INIS)

    1986-10-01

    This report provides a summary description of the Modular High Temperature Gas-Cooled Reactor (MHTGR) concept and interim results of assessments of costs, safety, constructibility, operability, maintainability, and availability. Conceptual design of this concept was initiated in October 1985 and is scheduled for completion in 1987. Participating industrial contractors are Bechtel National, Inc. (BNI), Stone and Webster Engineering Corporation (SWEC), GA Technologies, Inc. (GA), General Electric Co. (GE), and Combustion Engineering, Inc

  20. Long-distance behavior of temperature correlation functions in the one-dimensional Bose gas

    Energy Technology Data Exchange (ETDEWEB)

    Kozlowski, K.K. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Maillet, J.M. [UMR 5672 du CNRS, ENS Lyon (France). Lab. de Physique; Slavnov, N.A. [Steklov Mathematical Institute, Moscow (Russian Federation)

    2010-12-15

    We describe a Bethe ansatz based method to derive, starting from a multiple integral representation, the long-distance asymptotic behavior at finite temperature of the density-density correlation function in the interacting onedimensional Bose gas. We compute the correlation lengths in terms of solutions of non-linear integral equations of the thermodynamic Bethe ansatz type. Finally, we establish a connection between the results obtained in our approach with the correlation lengths stemming from the quantum transfer matrix method. (orig.)

  1. Probabilistic safety assessment framework of pebble-bed modular high-temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Liu Tao; Tong Jiejuan; Zhao Jun; Cao Jianzhu; Zhang Liguo

    2009-01-01

    After an investigation of similar reactor type probabilistic safety assessment (PSA) framework, Pebble-bed Modular High-Temperature Gas-cooled Reactor (HTR-PM) PSA framework was presented in correlate with its own design characteristics. That is an integral framework which spreads through event sequence structure with initiating events at the beginning and source term categories in the end. The analysis shows that it is HTR-PM design feature that determines its PSA framework. (authors)

  2. HTGR [High Temperature Gas-Cooled Reactor] ingress analysis using MINET

    International Nuclear Information System (INIS)

    Van Tuyle, G.J.; Yang, J.W.; Kroeger, P.G.; Mallen, A.N.; Aronson, A.L.

    1989-04-01

    Modeling of water/steam ingress into the primary (helium) cooling circuit of a High Temperature Gas-Cooled Reactor (HTGR) is described. This modeling was implemented in the MINET Code, which is a program for analyzing transients in intricate fluid flow and heat transfer networks. Results from the simulation of a water ingress event postulated for the Modular HTGR are discussed. 27 refs., 6 figs., 6 tabs

  3. Thermal-hydraulic code selection for modular high temperature gas-cooled reactors

    Energy Technology Data Exchange (ETDEWEB)

    Komen, E M.J.; Bogaard, J.P.A. van den

    1995-06-01

    In order to study the transient thermal-hydraulic system behaviour of modular high temperature gas-cooled reactors, the thermal-hydraulic computer codes RELAP5, MELCOR, THATCH, MORECA, and VSOP are considered at the Netherlands Energy Research Foundation ECN. This report presents the selection of the most appropriate codes. To cover the range of relevant accidents, a suite of three codes is recommended for analyses of HTR-M and MHTGR reactors. (orig.).

  4. High-Temperature Desulfurization of Heavy Fuel-Derived Reformate Gas Streams for SOFC Applications

    Science.gov (United States)

    Flytzani-Stephanopoulos, Maria; Surgenor, Angela D.

    2007-01-01

    Desulfurization of the hot reformate gas produced by catalytic partial oxidation or autothermal reforming of heavy fuels, such as JP-8 and jet fuels, is required prior to using the gas in a solid oxide fuel cell (SOFC). Development of suitable sorbent materials involves the identification of sorbents with favorable sulfidation equilibria, good kinetics, and high structural stability and regenerability at the SOFC operating temperatures (650 to 800 C). Over the last two decades, a major barrier to the development of regenerable desulfurization sorbents has been the gradual loss of sorbent performance in cyclic sulfidation and regeneration at such high temperatures. Mixed oxide compositions based on ceria were examined in this work as regenerable sorbents in simulated reformate gas mixtures and temperatures greater than 650 C. Regeneration was carried out with dilute oxygen streams. We have shown that under oxidative regeneration conditions, high regeneration space velocities (greater than 80,000 h(sup -1)) can be used to suppress sulfate formation and shorten the total time required for sorbent regeneration. A major finding of this work is that the surface of ceria and lanthanan sorbents can be sulfided and regenerated completely, independent of the underlying bulk sorbent. This is due to reversible adsorption of H2S on the surface of these sorbents even at temperatures as high as 800 C. La-rich cerium oxide formulations are excellent for application to regenerative H2S removal from reformate gas streams at 650 to 800 C. These results create new opportunities for compact sorber/regenerator reactor designs to meet the requirements of solid oxide fuel cell systems at any scale.

  5. Characterization of effluents from a high-temperature gas-cooled reactor fuel refabrication plant

    International Nuclear Information System (INIS)

    Judd, M.S.; Bradley, R.A.; Olsen, A.R.

    1975-12-01

    The types and quantities of chemical and radioactive effluents that would be released from a reference fuel refabrication facility for the High-Temperature Gas-Cooled Reactor (HTGR) have been determined. This information will be used to predict the impact of such a facility on the environment, to identify areas where additional development work needs to be done to further identify and quantify effluent streams, and to limit effluent release to the environment

  6. Pressure of a partially ionized hydrogen gas : numerical results from exact low temperature expansions

    OpenAIRE

    Alastuey , Angel; Ballenegger , Vincent

    2010-01-01

    8 pages; International audience; We consider a partially ionized hydrogen gas at low densities, where it reduces almost to an ideal mixture made with hydrogen atoms in their ground-state, ionized protons and ionized electrons. By performing systematic low-temperature expansions within the physical picture, in which the system is described as a quantum electron-proton plasma interacting via the Coulomb potential, exact formulae for the first five leading corrections to the ideal Saha equation ...

  7. High Temperature Gas-Cooled Test Reactor Point Design: Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Sterbentz, James William [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bayless, Paul David [Idaho National Lab. (INL), Idaho Falls, ID (United States); Nelson, Lee Orville [Idaho National Lab. (INL), Idaho Falls, ID (United States); Gougar, Hans David [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kinsey, J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Strydom, Gerhard [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-03-01

    A point design has been developed for a 200-MW high-temperature gas-cooled test reactor. The point design concept uses standard prismatic blocks and 15.5% enriched uranium oxycarbide fuel. Reactor physics and thermal-hydraulics simulations have been performed to characterize the capabilities of the design. In addition to the technical data, overviews are provided on the technology readiness level, licensing approach, and costs of the test reactor point design.

  8. High Temperature Gas-Cooled Test Reactor Point Design: Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Sterbentz, James William [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bayless, Paul David [Idaho National Lab. (INL), Idaho Falls, ID (United States); Nelson, Lee Orville [Idaho National Lab. (INL), Idaho Falls, ID (United States); Gougar, Hans David [Idaho National Lab. (INL), Idaho Falls, ID (United States); Strydom, Gerhard [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-01-01

    A point design has been developed for a 200-MW high-temperature gas-cooled test reactor. The point design concept uses standard prismatic blocks and 15.5% enriched uranium oxycarbide fuel. Reactor physics and thermal-hydraulics simulations have been performed to characterize the capabilities of the design. In addition to the technical data, overviews are provided on the technology readiness level, licensing approach, and costs of the test reactor point design.

  9. DOE pursuing accelerated cleanup at Fernald

    International Nuclear Information System (INIS)

    Borgman, T.

    1996-01-01

    The timing is right, and officials at Fernald are ready to initiate final cleanup actions-at an accelerated pace. open-quotes We have a viable, aggressive plan in place that will reduce the risks associated with the site by accelerating the cleanup schedule, and save a lot of time and money in the process,close quotes said Don Ofte, president of the Fernald Environmental Restoration management Corporation (FERMCO). Ofte is referring to the accelerated cleanup plan that the U.S. Department of Energy has approved to complete the remediation of Fernald in approximately 10 years-instead of 25-30 years-at a cost savings to taxpayers of almost $3 billion. This article describes the scenario at Fernald and politically which has lead to this decision

  10. DISTRIBUTION OF THE TEMPERATURE IN THE ASH-GAS FLOW DURING KORYAKSKY VOLCANO ERUPTION IN 2009

    Science.gov (United States)

    Gordeev, E.; Droznin, V.

    2009-12-01

    The observations of the ash-gas plumes during the Koryaksky eruption in March 2009 by the high resolution thermovision camera allowed obtaining thermal distributions inside the ash-gas flows. The plume structure is formed by single emissions. They rise at the rate of 5.5-7 m/s. The plume structure in general is represented as 3 zones: 1. a zone of high heat exchange; 2. a zone of floating up; 3. a zone of lateral movement. The plume temperature within the zone of lateral movement exceeds the atmospheric temperature by 3-5 oC, within the zone of floating up it exceeds by 20 oC. Its rate within the zone of floating up comprises 5-7 m/s. At the boundary between the zones of high heat exchange and floating up where we know the plume section, from heat balance equation we can estimate steam rate and heat power of the fluid thermal flow. Power of the overheated steam was estimated as Q=35 kg/s. It forms the ash-gas plume from the eruption and has temperature equal to 450 oC. The total volume of water steam produced during 100 days of eruption was estimated 3*105 t, its energy - 109 MJ.

  11. Analysis of fuel centre temperatures and fission gas release data from the IFPE Database

    International Nuclear Information System (INIS)

    Schubert, A.; Lassmann, K.; Van Uffelen, P.; Van de Laar, J.; Elenkov, D.; Asenov, S.; Boneva, S.; Djourelov, N.; Georgieva, M.

    2003-01-01

    The present work has continued the analysis of fuel centre temperatures and fission gas release, calculated with standard options of the TRANSURANUS code. The calculations are compared to experimental data from the International Fuel Performance Experiments (IFPE) database. It is reported an analysis regarding UO 2 fuel for Western-type reactors: Fuel centre temperatures measured in the experiments Contact 1 and Contact 2 (in-pile tests of 2 rods performed at the Siloe reactor in Grenoble, France, closely simulating commercial PWR conditions); Fission gas release data derived from post-irradiation examinations of 9 fuel rods belonging to the High-Burnup Effects Programme, task 3 (HBEP3). The results allow for a comparison of predictions by TRANSURANUS for the mentioned Western-type fuels with those done previously for Russian-type WWER fuel. The comparison has been extended to include fuel centre temperatures as well as fission gas release. The present version of TRANSURANUS includes a model that calculates the production of Helium. The amount of produced Helium is compared to the measured and to the calculated release of the fission gases Xenon and Krypton

  12. HARVESTING EMSP RESEARCH RESULTS FOR WASTE CLEANUP

    Energy Technology Data Exchange (ETDEWEB)

    Guillen, Donna Post; Nielson, R. Bruce; Phillips, Ann Marie; Lebow, Scott

    2003-02-27

    The extent of environmental contamination created by the nuclear weapons legacy combined with expensive, ineffective waste cleanup strategies at many U.S. Department of Energy (DOE) sites prompted Congress to pass the FY96 Energy and Water Development Appropriations Act, which directed the DOE to: ''provide sufficient attention and resources to longer-term basic science research, which needs to be done to ultimately reduce cleanup costs'', ''develop a program that takes advantage of laboratory and university expertise, and'' ''seek new and innovative cleanup methods to replace current conventional approaches which are often costly and ineffective.'' In response, the DOE initiated the Environmental Management Science Program (EMSP)-a targeted, long-term research program intended to produce solutions to DOE's most pressing environmental problems. EMSP funds basic research to lower cleanup cost and reduce risk to workers, the public, and the environment; direct the nation's scientific infrastructure towards cleanup of contaminated waste sites; and bridge the gap between fundamental research and technology development activities. EMSP research projects are competitively awarded based on the project's scientific, merit coupled with relevance to addressing DOE site needs. This paper describes selected EMSP research projects with long, mid, and short-term deployment potential and discusses the impacts, focus, and results of the research. Results of EMSP research are intended to accelerate cleanup schedules, reduce cost or risk for current baselines, provide alternatives for contingency planning, or provide solutions to problems where no solutions exist.

  13. Fabrication of ultra-high sensitive and selective CH4 room temperature gas sensing of TiO2nanorods: Detailed study on the annealing temperature

    CSIR Research Space (South Africa)

    Tshabalala, Zamaswazi P

    2016-07-01

    Full Text Available Applications of ultra-highly sensitive and selective methane (CH(sub4)) room temperature gas sensors are important for various operations especially in underground mining environment. Therefore, this study is set out to investigate the effect...

  14. Retroactive insurance may fund TMI-2 cleanup

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    A Pennsylvania task force recommended that nuclear utilities insure their plants with a mandatory national property insurance program. The proposed Nuclear Powerplant Property Damage Insurance Act of 1981 will cover the cleanup costs of onsite damage in excess of $350 million for a single accident ($50 million when private insurance is added on) and a ceiling of two billion dollars. Participation in the insurance pool would be in conjunction with licensing and would permit no grandfathering. Total payout for Three Mile Island-2 would cover 75% of the cleanup costs, the remainder to be apportioned among other parties. The insurance pool will have a $750 million goal supported by utility premiums

  15. A System And Method To Determine Thermophysical Properties Of A Multi-Component Gas At Arbitrary Temperature And Pressure

    Science.gov (United States)

    Morrow, Thomas E.; Behring, II, Kendricks A.

    2004-03-09

    A method to determine thermodynamic properties of a natural gas hydrocarbon, when the speed of sound in the gas is known at an arbitrary temperature and pressure. Thus, the known parameters are the sound speed, temperature, pressure, and concentrations of any dilute components of the gas. The method uses a set of reference gases and their calculated density and speed of sound values to estimate the density of the subject gas. Additional calculations can be made to estimate the molecular weight of the subject gas, which can then be used as the basis for mass flow calculations, to determine the speed of sound at standard pressure and temperature, and to determine various thermophysical characteristics of the gas.

  16. Study on restriction method for end-wall boundary layer thickness in axial helium gas compressor for gas turbine high temperature gas cooled reactor

    International Nuclear Information System (INIS)

    Takada, Shoji; Takizuka, Takakazu; Yan, Xing; Kunitomi, Kazuhiko; Inagaki, Yoshiyuki

    2009-01-01

    Aerodynamic performance test was carried out using a 1/3 scale, 4-stage model of the helium gas compressor to investigate an effect of end-wall over-camber to prevent decrease of axial velocity in the end-wall boundary layer. The model compressor consists of a rotor, 500 mm in diameter, which is driven by an electric motor at a rotational speed of 10800 rpm. The rotor blade span of the first stage is 34 mm. The test was carried out under the condition that the helium gas pressure of 0.88 MPa, temperature of 30degC, and mass flow rate of 12.47 kg/s at the inlet. A 3-dimensional aerodynamic code, which was verified using the test data, showed that axial velocity was lowered by using a blade which increased the inlet blade angle around the end-wall region of the casing side in comparison with that using the original design blade, because the inlet flow angle mismatched with the inlet blade angle of the rotor blade, as opposed to the prediction by a conventional air compressor design method. The overall adiabatic efficiency of the full scale 20-stage helium gas compressor was predicted 89.7% from the Reynolds number dependency of the test data by using the original design blade. (author)

  17. Role of temperature on static correlational properties in a spin-polarized electron gas

    Energy Technology Data Exchange (ETDEWEB)

    Arora, Priya; Moudgil, R. K., E-mail: rkmoudgil@kuk.ac.in [Department of Physics, Kurukshetra University, Kurukshetra – 136 119 (India); Kumar, Krishan [S. D. College (Lahore), Ambala Cantt. - 133001 (India)

    2016-05-06

    We have studied the effect of temperature on the static correlational properties of a spin-polarized three-dimensional electron gas (3DEG) over a wide coupling and temperature regime. This problem has been very recently studied by Brown et al. using the restricted path-integral Monte Carlo (RPIMC) technique in the warm-dense regime. To this endeavor, we have used the finite temperature version of the dynamical mean-field theory of Singwi et al, the so-called quantum STLS (qSTLS) approach. The static density structure factor and the static pair-correlation function are calculated, and compared with the RPIMC simulation data. We find an excellent agreement with the simulation at high temperature over a wide coupling range. However, the agreement is seen to somewhat deteriorate with decreasing temperature. The pair-correlation function is found to become small negative for small electron separation. This may be attributed to the inadequacy of the mean-field theory in dealing with the like spin electron correlations in the strong-coupling domain. A nice agreement with RPIMC data at high temperature seems to arise due to weakening of both the exchange and coulomb correlations with rising temperature.

  18. Present state and future prospect of development of high temperature gas-cooled reactors in Japan

    International Nuclear Information System (INIS)

    Sanokawa, Konomo

    1994-01-01

    High temperature gas-cooled reactors can supply the heat of about 1000degC, and the high efficiency and the high rate of heat utilization can be attained. Also they have the features of excellent inherent safety, the easiness of operation, the high burnup of fuel and so on. The heat utilization of atomic energy in addition to electric power generation is very important in view of the protection of global environment and the diversification of energy supply. Japan Atomic Energy Research Institute has advanced the construction of the high temperature engineering test and research reactor (HTTR) of 30 MW thermal output, aiming at attaining the criticality in 1998. The progress of the development of a high temperature gas-cooled reactor is described. For 18 years, the design study of the reactor was advanced together with the research and development of the reactor physics, fuel and materials, high temperature machinery and equipment and others, and the decision of the design standard and the development of computation codes. The main specification and the construction schedule are shown. The reactor building was almost completed, and the reactor containment vessel was installed. The plan of the research and development by using the HTTR is investigated. (K.I.)

  19. Superfluid 3He at very low temperatures: a very unusual excitation gas

    International Nuclear Information System (INIS)

    Pickett, G.R.; Enrico, M.P.; Fisher, S.N.; Guenault, A.M.; Torizuka, K.

    1994-01-01

    The excitation gas in superfluid 3 He at low temperatures shows a number of remarkable dynamical properties arising from the unusual dispersion curve. The existence of an energy gap leads to many of the observed properties varying rapidly with temperature, since the excitation density is dominated by the gap Boltzmann factor exp(-Δ/kT). But also, the fact that the minimum energy lies at finite momentum gives rise to Andreev scattering processes, in which the velocity of the excitation is reversed but the momentum left virtually unchanged. Since the dispersion curve looks different to a moving observer, there is the possibility of the free production of quasiparticle-quasihole pairs at a Landau critical velocity. At low temperatures the mean free path becomes much larger than any experimental size. Using vibrating wire resonators as universal probes, we can monitor the temperature, measure the Kapitz resistance, examine the nonlinear regime beyond the two-fluid model, observe the Landau velocity, create and detect thermal beams of excitation with black-body radiators, observe Andreev reflection directly and probe A-phase textures (in which the gas is one-dimensional). Future possibilities are discussed. (orig.)

  20. Emission characteristics and axial flame temperature distribution of producer gas fired premixed burner

    Energy Technology Data Exchange (ETDEWEB)

    Bhoi, P.R. [Department of Mechanical Engineering, L and T-Sargent and Lundy Limited, L and T Energy Centre, Near Chhani Jakat Naka, Baroda 390 002 (India); Channiwala, S.A. [Department of Mechanical Engineering, Sardar Vallabhbhai National Institute of Technology, Deemed University, Ichchhanath, Surat 395 007, Gujarat (India)

    2009-03-15

    This paper presents the emission characteristics and axial flame temperature distribution of producer gas fired premixed burner. The producer gas fired premixed burner of 150 kW capacity was tested on open core throat less down draft gasifier system in the present study. A stable and uniform flame was observed with this burner. An instrumented test set up was developed to evaluate the performance of the burner. The conventional bluff body having blockage ratio of 0.65 was used for flame stabilization. With respect to maximum flame temperature, minimum pressure drop and minimum emissions, a swirl angle of 60 seems to be optimal. The experimental results also showed that the NO{sub x} emissions are inversely proportional to swirl angle and CO emissions are independent of swirl angle. The minimum emission levels of CO and NO{sub x} are observed to be 0.167% and 384 ppm respectively at the swirl angle of 45-60 . The experimental results showed that the maximum axial flame temperature distribution was achieved at A/F ratio of 1.0. The adiabatic flame temperature of 1653 C was calculated theoretically at A/F ratio of 1.0. Experimental results are in tune with theoretical results. It was also concluded that the CO and UHC emissions decreases with increasing A/F ratio while NO{sub x} emissions decreases on either side of A/F ratio of 1.0. (author)

  1. Analysis of pressure drop accidents in high temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Kameoka, Toshiyuki

    1980-01-01

    Research and development are carried out on various problems in order to realize a multi-purpose, high temperature gas-cooled experimental reactor by Japan Atomic Energy Research Institute and others. In the experimental reactor in consideration at present, it is planned to flow helium at 1000 deg C and 40 atm. For the purpose, high temperature heat insulation structures are designed and developed, which insulate heat on the internal surfaces of pressure vessels and pipings. Consideration must be given to these internal heat insulation structures about the various characteristics in the working environmental temperature and pressure conditions, the measures for preventing the by-pass flow due to the formation of gaps and the abnormal leak of heat through the natural convection in the heat insulators and others. In this paper, the experimental results on the rapid pressure reduction characteristics of ceramic fiber heat insulation structures are reported. The ceramic fiber heat insulation structures have the features such as the application to uneven surfaces and penetration parts, the prevention of by-pass flow, and very low permeability. The problem is the restoring force after the high temperature compression. The experiment on rapid pressure reduction due to the accidental release of gas and the results are reported. (Kako, I.)

  2. Temperature dependent electron transport and rate coefficient studies for e-beam-sustained diffuse gas discharge switching

    International Nuclear Information System (INIS)

    Carter, J.G.; Hunter, S.R.; Christophorou, L.G.

    1987-01-01

    Measurements of the electron drift velocity, w, attachment coefficient, eta/N/sub a/, and ionization coefficient, α/N, have been made in C 2 F 6 /Ar and C 2 F 6 /CH 4 gas mixtures at gas temperatures, T, of 300 and 500 0 K over the concentration range of 0.1 to 100% of the C 2 F 6 . These measurements are useful for modeling the expected behavior of repetitively operated electron-beam sustained diffuse gas discharge opening switches where gas temperatures within the switch are anticipated to rise several hundred degrees during switch operation

  3. Approaching Environmental Cleanup Costs Liability Through Insurance Principles

    National Research Council Canada - National Science Library

    Corbin, Michael A

    1994-01-01

    .... Applying insurance industry principles to environmental cleanup costs liability will provide a firm foundation to reduce the risk of loss to the taxpayer, reduce cleanup costs, and stimulate private...

  4. Measurements of electron density and temperature profiles in a gas blanket experiment

    International Nuclear Information System (INIS)

    Kuthy, A.

    1979-02-01

    Radial profiles of electron density, temperature and H sub(β) intensity are presented for the rotating plasma device F-1. The hydrogen filling pressure, the average magnetic field strength at the midplane, and the power input to the discharge have been varied in the ranges 10-100 mTorr, 0.25-0.5 Tesla, and 0.1 to 1.5 MW, respectively. These experiments have been performed with the main purpose of studying the gas blanket (cold-mantle) state of the plasma. It is shown, that a simple spectroscopic method can be used to derive the radial distribution of the electron temperature in such plasmas. The observed peak temperatures and densities are in agreement with earlier theoretical estimates. (author)

  5. Non-condensible gas fraction predictions using wet and dry bulb temperature measurements

    International Nuclear Information System (INIS)

    Bowman, J.; Griffith, P.

    1983-03-01

    A technique is presented whereby non-condensible gas mass fractions in a closed system can be determined using wet bulb and dry bulb temperature and system pressure measurements. This technique would have application in situations where sampling techniques could not be used. Using an energy balance about the wet bulb wick, and expression is obtained which relates the vapor concentration difference between the wet bulb wick and the free stream to the wet and dry bulb temperature difference and a heat to mass transfer coefficient ratio. This coefficient ratio was examined for forced and natural convection flows. This analysis was verified with forced and natural convection tests over the range of pressure and temperature from 50 to 557 psig and 415 to 576 0 F. All the data could best be fit by the natural convection analysis. This is useful when no information about the flow field is known

  6. Nonlinear vacuum gas flow through a short tube due to pressure and temperature gradients

    Energy Technology Data Exchange (ETDEWEB)

    Pantazis, Sarantis; Naris, Steryios; Tantos, Christos [Department of Mechanical Engineering, University of Thessaly, Pedion Areos, 38334 Volos (Greece); Valougeorgis, Dimitris, E-mail: diva@mie.uth.gr [Department of Mechanical Engineering, University of Thessaly, Pedion Areos, 38334 Volos (Greece); André, Julien; Millet, Francois; Perin, Jean Paul [Service des Basses Températures, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble, F-38054 (France)

    2013-10-15

    The flow of a rarefied gas through a tube due to both pressure and temperature gradients has been studied numerically. The main objective is to investigate the performance of a mechanical vacuum pump operating at low temperatures in order to increase the pumped mass flow rate. This type of pump is under development at CEA-Grenoble. The flow is modelled by the Shakhov kinetic model equation, which is solved by the discrete velocity method. Results are presented for certain geometry and flow parameters. Since according to the pump design the temperature driven flow is in the opposite direction than the main pressure driven flow, it has been found that for the operating pressure range studied here the net mass flow rate through the pump may be significantly reduced.

  7. Nonlinear vacuum gas flow through a short tube due to pressure and temperature gradients

    International Nuclear Information System (INIS)

    Pantazis, Sarantis; Naris, Steryios; Tantos, Christos; Valougeorgis, Dimitris; André, Julien; Millet, Francois; Perin, Jean Paul

    2013-01-01

    The flow of a rarefied gas through a tube due to both pressure and temperature gradients has been studied numerically. The main objective is to investigate the performance of a mechanical vacuum pump operating at low temperatures in order to increase the pumped mass flow rate. This type of pump is under development at CEA-Grenoble. The flow is modelled by the Shakhov kinetic model equation, which is solved by the discrete velocity method. Results are presented for certain geometry and flow parameters. Since according to the pump design the temperature driven flow is in the opposite direction than the main pressure driven flow, it has been found that for the operating pressure range studied here the net mass flow rate through the pump may be significantly reduced

  8. Experiment Plan of High Temperature Steam and Carbon dioxide Co-electrolysis for Synthetic Gas Production

    International Nuclear Information System (INIS)

    Yoon, Duk-Joo; Ko, Jae-Hwa

    2008-01-01

    Currently, Solid oxide fuel cells (SOFC) come into the spotlight in the middle of the energy technologies of the future for highly effective conversion of fossil fuels into electricity without carbon dioxide emission. The SOFC is a reversible cell. By applying electrical power to the cell, which is solid oxide electrolysis cell (SOEC), it is possible to produce synthetic gas (syngas) from high temperature steam and carbon dioxide. The produced syngas (hydrogen and carbon monoxide) can be used for synthetic fuels. This SOEC technology can use high temperature from VHTRs for high efficiency. This paper describes KEPRI's experiment plan of high temperature steam and carbon co-electrolysis for syngas production using SOEC technology

  9. Tomography for two-dimensional gas temperature distribution based on TDLAS

    Science.gov (United States)

    Luo, Can; Wang, Yunchu; Xing, Fei

    2018-03-01

    Based on tunable diode laser absorption spectroscopy (TDLAS), the tomography is used to reconstruct the combustion gas temperature distribution. The effects of number of rays, number of grids, and spacing of rays on the temperature reconstruction results for parallel ray are researched. The reconstruction quality is proportional to the ray number. The quality tends to be smoother when the ray number exceeds a certain value. The best quality is achieved when η is between 0.5 and 1. A virtual ray method combined with the reconstruction algorithms is tested. It is found that virtual ray method is effective to improve the accuracy of reconstruction results, compared with the original method. The linear interpolation method and cubic spline interpolation method, are used to improve the calculation accuracy of virtual ray absorption value. According to the calculation results, cubic spline interpolation is better. Moreover, the temperature distribution of a TBCC combustion chamber is used to validate those conclusions.

  10. The Electron Temperature of a Partially Ionized Gas in an Electric Field

    International Nuclear Information System (INIS)

    Robben, F.

    1968-03-01

    The electron temperature of a partially ionized gas in an electric field can be determined by the collision rate for momentum transfer and the collision rate for energy transfer. Mean values of these rates are defined such that a simple expression for the electron temperature is obtained, and which depends, among other things, on the ratio of these mean rates. This ratio is calculated in the Lorentz approximation for power law cross sections, and also as a function of the degree of ionization for a helium plasma. It is pointed out that the complete results of refined transport theory can be used in calculating electron mobility and electron temperature in a multicomponent plasma without undue difficulty

  11. Reducibility of ceria-lanthana mixed oxides under temperature programmed hydrogen and inert gas flow conditions

    International Nuclear Information System (INIS)

    Bernal, S.; Blanco, G.; Cifredo, G.; Perez-Omil, J.A.; Pintado, J.M.; Rodriguez-Izquierdo, J.M.

    1997-01-01

    The present paper deals with the preparation and characterization of La/Ce mixed oxides, with La molar contents of 20, 36 and 57%. We carry out the study of the structural, textural and redox properties of the mixed oxides, comparing our results with those for pure ceria. For this aim we use temperature programmed reduction (TPR), temperature programmed desorption (TPD), nitrogen physisorption at 77 K, X-ray diffraction and high resolution electron microscopy. The mixed oxides are more easy to reduce in a flow of hydrogen than ceria. Moreover, in an inert gas flow they release oxygen in higher amounts and at lower temperatures than pure CeO 2 . The textural stability of the mixed oxides is also improved by incorporation of lanthana. All these properties make the ceria-lanthana mixed oxides interesting alternative candidates to substitute ceria in three-way catalyst formulations. (orig.)

  12. The Electron Temperature of a Partially Ionized Gas in an Electric Field

    Energy Technology Data Exchange (ETDEWEB)

    Robben, F

    1968-03-15

    The electron temperature of a partially ionized gas in an electric field can be determined by the collision rate for momentum transfer and the collision rate for energy transfer. Mean values of these rates are defined such that a simple expression for the electron temperature is obtained, and which depends, among other things, on the ratio of these mean rates. This ratio is calculated in the Lorentz approximation for power law cross sections, and also as a function of the degree of ionization for a helium plasma. It is pointed out that the complete results of refined transport theory can be used in calculating electron mobility and electron temperature in a multicomponent plasma without undue difficulty.

  13. Gas phase analysis of CO interactions with solid surfaces at high temperatures

    International Nuclear Information System (INIS)

    Anghel, Clara; Hoernlund, Erik; Hultquist, Gunnar; Limbaeck, Magnus

    2004-01-01

    An in situ method including mass spectrometry and labeled gases is presented and used to gain information on adsorption of molecules at high temperatures (>300 deg. C). Isotopic exchange rate in H 2 upon exposure to an oxidized zicaloy-2 sample and exchange rate in CO upon exposure to various materials have been measured. From these measurements, molecular dissociation rates in respective system have been calculated. The influence of CO and N 2 on the uptake rate of H 2 in zirconium and oxidized zicaloy-2 is discussed in terms of tendency for adsorption at high temperatures. In the case of oxidized Cr exposed to CO gas with 12 C, 13 C, 16 O and 18 O, the influence of H 2 O is investigated with respect to dissociation of CO molecules. The presented data supports a view of different tendencies for molecular adsorption of H 2 O, CO, N 2 , and H 2 molecules on surfaces at high temperatures

  14. Critical evaluation of high-temperature gas-cooled reactors applicable to coal conversion

    International Nuclear Information System (INIS)

    Spiewak, I.; Jones, J.E. Jr.; Rittenhouse, P.L.; DeStefano, J.R.; Delene, J.G.

    1975-12-01

    A critical review is presented of the technology and costs of very high-temperature gas-cooled reactors (VHTRs) applicable to nuclear coal conversion. Coal conversion processes suitable for coupling to reactors are described. Vendor concepts of the VHTR are summarized. The materials requirements as a function of process temperature in the range 1400 to 2000 0 F are analyzed. Components, environmental and safety factors, economics and nuclear fuel cycles are reviewed. It is concluded that process heat supply in the range 1400 to 1500 0 F could be developed with a high degree of assurance. Process heat at 1600 0 F would require considerably more materials development. While temperatures up to 2000 0 F appear to be attainable, considerably more research and risk were involved. A demonstration plant would be required as a step in the commercialization of the VHTR

  15. New arrangement for the air cleanup system to recover tritium

    International Nuclear Information System (INIS)

    Nishikawa, Masabumi; Takahashi, Kohsaku; Munakata, Kenzo; Fukada, Satoshi; Kotoh, Kenji; Takeishi, Toshiharu

    1997-01-01

    At present, the standard arrangement of the air cleanup system responsible for emergency tritium recovery from room air is a catalytic oxidation bed with a heater followed by an adsorption bed with a cooler. One disadvantage of this arrangement is that trouble with the heater or the cooler could result in a loss of capacity to recover tritium. Another disadvantage of the catalyst-adsorption-bed arrangement is that tritiated water must be recovered with a high decontamination factor after dilution with a large amount of water vapor in the working atmosphere. The performance of a new arrangement for the air cleanup system, which consists of a precious metal catalyst bed preceded by an adsorption bed without heating equipment, is discussed. According to calculations, most of the tritium released to the room air is recovered in the catalyst bed through oxidation, adsorption, and isotope exchange reaction when the new arrangement is applied. The adsorption bed placed before the catalyst bed dehumidifies the process gas to such a degree that the oxidation reaction of tritium in the catalyst bed is not hindered by water vapor. 15 refs., 6 figs., 6 tabs

  16. Indium oxide octahedrons based on sol–gel process enhance room temperature gas sensing performance

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Xiaohui [Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, Shandong (China); Chen, Changlong, E-mail: chem.chencl@hotmail.com [Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, Shandong (China); Han, Liuyuan [Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, Shandong (China); Shao, Baiqi [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Wei, Yuling [Instrumental Analysis Center, Qilu University of Technology, Jinan 250353, Shandong (China); Liu, Qinglong; Zhu, Peihua [Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, Shandong (China)

    2015-07-15

    Highlights: • In{sub 2}O{sub 3} octahedron films are prepared based on sol–gel technique for the first time. • The preparation possesses merits of low temperature, catalyst-free and large production. • It was found that the spin-coating process in film fabrication was key to achieve the octahedrons. • The In{sub 2}O{sub 3} octahedrons could significantly enhance room temperature NO{sub 2} gas sensing performance. - Abstract: Indium oxide octahedrons were prepared on glass substrates through a mild route based on sol–gel technique. The preparation possesses characteristics including low temperature, catalyst-free and large production, which is much distinguished from the chemical-vapor-deposition based methods that usually applied to prepare indium oxide octahedrons. Detailed characterization revealed that the indium oxide octahedrons were single crystalline, with {1 1 1} crystal facets exposed. It was found that the spin-coating technique was key for achieving the indium oxide crystals with octahedron morphology. The probable formation mechanism of the indium oxide octahedrons was proposed based on the experiment results. Room temperature NO{sub 2} gas sensing measurements exhibited that the indium oxide octahedrons could significantly enhance the sensing performance in comparison with the plate-like indium oxide particles that prepared from the dip-coated gel films, which was attributed to the abundant sharp edges and tips as well as the special {1 1 1} crystal facets exposed that the former possessed. Such a simple wet-chemical based method to prepare indium oxide octahedrons with large-scale production is promising to provide the advanced materials that can be applied in wide fields like gas sensing, solar energy conversion, field emission, and so on.

  17. Indium oxide octahedrons based on sol–gel process enhance room temperature gas sensing performance

    International Nuclear Information System (INIS)

    Mu, Xiaohui; Chen, Changlong; Han, Liuyuan; Shao, Baiqi; Wei, Yuling; Liu, Qinglong; Zhu, Peihua

    2015-01-01

    Highlights: • In 2 O 3 octahedron films are prepared based on sol–gel technique for the first time. • The preparation possesses merits of low temperature, catalyst-free and large production. • It was found that the spin-coating process in film fabrication was key to achieve the octahedrons. • The In 2 O 3 octahedrons could significantly enhance room temperature NO 2 gas sensing performance. - Abstract: Indium oxide octahedrons were prepared on glass substrates through a mild route based on sol–gel technique. The preparation possesses characteristics including low temperature, catalyst-free and large production, which is much distinguished from the chemical-vapor-deposition based methods that usually applied to prepare indium oxide octahedrons. Detailed characterization revealed that the indium oxide octahedrons were single crystalline, with {1 1 1} crystal facets exposed. It was found that the spin-coating technique was key for achieving the indium oxide crystals with octahedron morphology. The probable formation mechanism of the indium oxide octahedrons was proposed based on the experiment results. Room temperature NO 2 gas sensing measurements exhibited that the indium oxide octahedrons could significantly enhance the sensing performance in comparison with the plate-like indium oxide particles that prepared from the dip-coated gel films, which was attributed to the abundant sharp edges and tips as well as the special {1 1 1} crystal facets exposed that the former possessed. Such a simple wet-chemical based method to prepare indium oxide octahedrons with large-scale production is promising to provide the advanced materials that can be applied in wide fields like gas sensing, solar energy conversion, field emission, and so on

  18. Study on thermodynamic cycle of high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Qu Xinhe; Yang Xiaoyong; Wang Jie

    2017-01-01

    The development trend of the (very) High temperature gas-cooled reactor is to gradually increase the reactor outlet temperature. The different power conversion units are required at the different reactor outlet temperature. In this paper, for the helium turbine direct cycle and the combined cycle of the power conversion unit of the High temperature gas-cooled reactor, the mathematic models are established, and three cycle plans are designed. The helium turbine direct cycle is a Brayton cycle with recuperator, precooler and intercooler. In the combined cycle plan 1, the topping cycle is a simple Brayton cycle without recuperator, precooler and intercooler, and the bottoming cycle is based on the steam parameters (540deg, 6 MPa) recommended by Siemens. In the combined cycle plan 2, the topping cycle also is a simple Brayton cycle, and the bottoming cycle which is a Rankine cycle with reheating cycle is based on the steam parameters of conventional subcritical thermal power generation (540degC, 18 MPa). The optimization results showed that the cycle efficiency of the combined cycle plan 2 is the highest, the second is the helium turbine direct cycle, and the combined cycle plan 2 is the lowest. When the reactor outlet temperature is 900degC and the pressure ratio is 2.02, the cycle efficiency of the combined cycle plan 2 can reach 49.7%. The helium turbine direct cycle has a reactor inlet temperature above 500degC due to the regenerating cycle, so it requires a cooling circuit for the internal wall of the reactor pressure vessel. When the reactor outlet temperature increases, the increase of the pressure ratio required by the helium turbine direct cycle increases may bring some difficulties to the design and manufacture of the magnetic bearings. For the combined cycle, the reactor inlet temperature can be controlled below than 370degC, so the reactor pressure vessel can use SA533 steel without cooling the internal wall of the reactor pressure vessel. The pressure

  19. Radioactive Waste and Clean-up Division

    International Nuclear Information System (INIS)

    Collard, G.

    2001-01-01

    The main objectives of the Radioactive Waste and Clean-up division of SCK-CEN are outlined. The division's programme consists of research, development and demonstration projects and aims to contribute to the objectives of Agenda 21 on sustainable development in the field of radioactive waste and rehabilitation of radioactively contaminated sites

  20. Flood Cleanup to Protect Indoor Air Quality

    Science.gov (United States)

    During a flood cleanup, the indoor air quality in your home or office may appear to be the least of your problems. However, failure to remove contaminated materials and to reduce moisture and humidity can present serious long-term health risks.

  1. Evaluation of contaminated groundwater cleanup objectives

    International Nuclear Information System (INIS)

    Arquiett, C.; Gerke, M.; Datskou, I.

    1996-01-01

    The US Department of Energy's (DOE's) Environmental Restoration Program will be responsible for remediating the approximately 230 contaminated groundwater sites across the DOE Complex. A major concern for remediation is choosing the appropriate cleanup objective. The cleanup objective chosen will influence the risk to the nearby public during and after remediation; risk to remedial and non-involved workers during remediation; and the cost of remediation. This paper discusses the trends shown in analyses currently being performed at Oak Ridge National Laboratories' (ORNL's) Center for Risk Management (CRM). To evaluate these trends, CRM is developing a database of contaminated sites. This paper examines several contaminated groundwater sites selected for assessment from CRM's data base. The sites in this sample represent potential types of contaminated groundwater sites commonly found at an installation within DOE. The baseline risk from these sites to various receptors is presented. Residual risk and risk during remediation is reported for different cleanup objectives. The cost associated with remediating to each of these objectives is also estimated for each of the representative sites. Finally, the general trends of impacts as a function of cleanup objective will be summarized. The sites examined include the Savannah River site, where there was substantial ground pollution from radionuclides, oil, coal stockpiles, and other forms of groundwater contamination. The effects of various types of groundwater contamination on various types of future user is described. 4 refs., 3 figs., 2 tabs

  2. US nuclear cleanup shows signs of progress

    International Nuclear Information System (INIS)

    Renner, R.

    1997-01-01

    The U.S. Department of Energy's program for dealing with the radioactive and hazardous wastes at its former nuclear weapons production sites and at the national laboratories has been criticized for its expense and slow pace of cleanup. The largest environmental restoration and waste management program in the world faces formidable technical and scientific problems and these, according to numerous investigative committees and commissions, have been compounded by poor management, misuse of technology, and failure to appreciate the need for new basic scientific knowledge to solve many of the cleanup problems. In the past three years, DOE's Office of Environmental Management (EM), often spurred by congressional action, has begun to trim costs and accomplish more. New measures have been introduced to improve contract efficiency, better utilize existing remediation technologies, renegotiate compliance agreements, and begin basic research. Environmental Management Assistant Undersecretary Alvin Alm, appointed in May 1996, is seeking to solidify these changes into an ambitious plan to clean up most of DOE's 130 sites by 2006. But there are widespread doubts that EM has the money, skill, and will to turn itself around. There are also concerns that, in the name of efficiency and economy, EM may be negotiating lower cleanup standards and postponing some difficult cleanup tasks. This article discusses these issues. 7 refs

  3. Effects of inlet distortion on gas turbine combustion chamber exit temperature profiles

    Science.gov (United States)

    Maqsood, Omar Shahzada

    Damage to a nozzle guide vane or blade, caused by non-uniform temperature distributions at the combustion chamber exit, is deleterious to turbine performance and can lead to expensive and time consuming overhaul and repair. A test rig was designed and constructed for the Allison 250-C20B combustion chamber to investigate the effects of inlet air distortion on the combustion chamber's exit temperature fields. The rig made use of the engine's diffuser tubes, combustion case, combustion liner, and first stage nozzle guide vane shield. Rig operating conditions simulated engine cruise conditions, matching the quasi-non-dimensional Mach number, equivalence ratio and Sauter mean diameter. The combustion chamber was tested with an even distribution of inlet air and a 4% difference in airflow at either side. An even distribution of inlet air to the combustion chamber did not create a uniform temperature profile and varying the inlet distribution of air exacerbated the profile's non-uniformity. The design of the combustion liner promoted the formation of an oval-shaped toroidal vortex inside the chamber, creating localized hot and cool sections separated by 90° that appeared in the exhaust. Uneven inlet air distributions skewed the oval vortex, increasing the temperature of the hot section nearest the side with the most mass flow rate and decreasing the temperature of the hot section on the opposite side. Keywords: Allison 250, Combustion, Dual-Entry, Exit Temperature Profile, Gas Turbine, Pattern Factor, Reverse Flow.

  4. Measurement of gas temperature and OH density in the afterglow of pulsed positive corona discharge

    International Nuclear Information System (INIS)

    Ono, Ryo; Oda, Tetsuji

    2008-01-01

    The gas temperature and OH density in the afterglow of pulsed positive corona discharge are measured using the laser-induced predissociation fluorescence (LIPF) of OH radicals. Discharge occurs in a 13 mm point-to-plane gap in an atmospheric-pressure H 2 O(2.8%)/O 2 (2.0%)/N 2 mixture. The temperature measurement shows that (i) the temperature increases after discharge and (ii) the temperature near the anode tip (within 1 mm from the anode tip) is much higher than that of the rest of the discharge volume. Near the anode tip, the temperature increases from 500 K (t = 0 μs) to 1100 K (t = 20 μs), where t is the postdischarge time, while it increases from 400 K (t = 0 μs) to 700 K (t = 100 μs) in the rest of the discharge volume away from the anode tip. This temperature difference between the two volumes (near and far from the anode tip) causes a difference in the decay rate of OH density: OH density near the anode tip decays approximately 10 times slower than that far from the tip. The spatial distribution of OH density shows good agreement with that of the secondary streamer luminous intensity. This shows that OH radicals are mainly produced in the secondary streamer, not in the primary one

  5. Enhancement of NH3 gas sensitivity at room temperature by carbon nanotube-based sensor coated with Co nanoparticles.

    Science.gov (United States)

    Nguyen, Lich Quang; Phan, Pho Quoc; Duong, Huyen Ngoc; Nguyen, Chien Duc; Nguyen, Lam Huu

    2013-01-30

    Multi-walled carbon nanotube (MWCNT) film has been fabricated onto Pt-patterned alumina substrates using the chemical vapor deposition method for NH(3) gas sensing applications. The MWCNT-based sensor is sensitive to NH(3) gas at room temperature. Nanoclusters of Co catalysts have been sputtered on the surface of the MWCNT film to enhance gas sensitivity with respect to unfunctionalized CNT films. The gas sensitivity of Co-functionalized MWCNT-based gas sensors is thus significantly improved. The sensor exhibits good repeatability and high selectivity towards NH(3), compared with alcohol and LPG.

  6. Enhancement of NH3 Gas Sensitivity at Room Temperature by Carbon Nanotube-Based Sensor Coated with Co Nanoparticles

    Directory of Open Access Journals (Sweden)

    Lich Quang Nguyen

    2013-01-01

    Full Text Available Multi-walled carbon nanotube (MWCNT film has been fabricated onto Pt-patterned alumina substrates using the chemical vapor deposition method for NH3 gas sensing applications. The MWCNT-based sensor is sensitive to NH3 gas at room temperature. Nanoclusters of Co catalysts have been sputtered on the surface of the MWCNT film to enhance gas sensitivity with respect to unfunctionalized CNT films. The gas sensitivity of Co-functionalized MWCNT-based gas sensors is thus significantly improved. The sensor exhibits good repeatability and high selectivity towards NH3, compared with alcohol and LPG.

  7. Testing and analyses of a high temperature duct for gas-cooled reactors

    International Nuclear Information System (INIS)

    Black, W.E.; Roberge, A.; Felten, P.; Bastien, R.

    1979-01-01

    A 0.6 scale model of a steam cycle gas-cooled reactor high temperature duct was tested in a closed loop helium facility. The object of the test series was to determine: 1) the thermal effects of gas permeation within the thermal barrier, 2) the plastic deformation of the metallic components, and 3) the thermal performance of the fibrous insulation. A series of tests was performed with thermal cyclings from 100 0 C to 760 0 C at 50 atmospheres until the system thermal performance had stabilized hence enabling predictions for the reactor life. Additional tests were made to assess permeation by deliberately simulating sealing weld failures thereby allowing gas flow by-pass within the primary thermal barrier. After 100 cycles the entire primary structure was found to have performed without structural failure. Due to high pressures exerted by the insulation on the cover plates and a design oversight, the thin seal sheets were unable to expand in an anticipated manner. Local buckling resulted. Pre and post test metallurgical analyses were conducted on the Hastelloy-X structures and reference specimens. The results gave evidence of aging in the form of noticeable changes in room temperature tensile and reduction in area parameters. The Hastelloy-X welds exhibited greater changes in properties due to thermal aging. The antifriction coating (Cr 3 C 2 ) performed well without spallation or excessive wear. (orig.)

  8. The modular high-temperature gas-cooled reactor (MHTGR) in the US

    International Nuclear Information System (INIS)

    Neylan, A.J.; Graf, D.F.; Millunzi, A.C.

    1987-01-01

    GA Technologies Inc. and other U.S. corporations, in a cooperative program with the U.S. Department of Energy, is developing a Modular High-Temperature Gas-Cooled Reactor (MHTGR) that will provide highly reliable, economic, nuclear power. The MHTGR system assures maximum safety to the public, the owner/operator, and the environment. The MHTGR is being designed to meet and exceed rigorous requirements established by the user industry for availability, operation and maintenance, plant investment protection, safety and licensing, siting flexibility and economics. The plant will be equally attractive for deployment and operation in the U.S., other major industrialized nations including Korea, Japan, and the Republic of China, as well as the developing nations. The High-Temperature Gas-Cooled Reactor (HTGR) is an advanced, third generation nuclear power system which incorporates distinctive technical features, including the use of pressurized helium as a coolant, graphite as the moderator and core structural material, and fuel in the form of ceramic coated uranium particles. The modular HTGR builds upon generic gas-cooled reactor experience and specific HTGR programs and projects. The MHTGR offers unique technological features and the opportunity for the cooperative international development of an advanced energy system that will help assure adaquate world energy resources for the future. Such international joint venturing of energy development can offer significant benefits to participating industries and governments and also provides a long term solution to the complex problems of the international balance of payments

  9. Basic study on high temperature gas cooled reactor technology for hydrogen production

    International Nuclear Information System (INIS)

    Chang, Jong Hwa; Lee, W. J.; Lee, H. M.

    2003-01-01

    The annual production of hydrogen in the world is about 500 billion m 3 . Currently hydrogen is consumed mainly in chemical industries. However hydrogen has huge potential to be consumed in transportation sector in coming decades. Assuming that 10% of fossil energy in transportation sector is substituted by hydrogen in 2020, the hydrogen in the sector will exceed current hydrogen consumption by more than 2.5 times. Currently hydrogen is mainly produced by steam reforming of natural gas. Steam reforming process is chiefest way to produce hydrogen for mass production. In the future, hydrogen has to be produced in a way to minimize CO2 emission during its production process as well as to satisfy economic competition. One of the alternatives to produce hydrogen under such criteria is using heat source of high-temperature gas-cooled reactor. The high-temperature gas-cooled reactor represents one type of the next generation of nuclear reactors for safe and reliable operation as well as for efficient and economic generation of energy

  10. Cleanups In My Community (CIMC) - Recovery Act Funded Cleanups, National Layer

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data layer provides access to Recovery Act Funded Cleanup sites as part of the CIMC web service. The American Recovery and Reinvestment Act was signed into law...

  11. Effectiveness of cleanup criteria relative to an accidental nuclear release

    International Nuclear Information System (INIS)

    Chen, S.Y.; Yuan, Y.C.

    1988-01-01

    In the event of an accidental nuclear release, the associated long-term radiological risks would result primarily from ground contamination pathways. Cleanup of the contaminated ground surfaces is a necessary step toward reducing the radiological risk to the general population. Ideally, the radiological risk decreases as the level of cleanup effort increases; however, as the cleanup criterion (i.e., the required contaminant concentration after cleanup) becomes more stringent, the cleanup effort may become prohibitively costly. This study examines several factors that are important in determining the effectiveness of the cleanup criteria for selected radionuclides: (a) annual individual dose commitment (mrem/yr), (b) total population environmental dose commitment (person-rem), and (c) total area (km 2 ) requiring cleanup following an accident. To effectively protect the general population, the benefits of cleanup should be weighed against the potentially large increase in cleanup area (and the associated costs) as the cleanup criterion becomes more stringent. The effectiveness of cleanup will vary, depending largely on site-specific parameters such as population density and agricultural productivity as well as on the amount and type of radionuclide released. Determination of an optimum cleanup criterion should account for all factors, including a comprehensive cost/benefit analysis

  12. Fast-Track Cleanup at Closing DoD Installations

    Science.gov (United States)

    The Fast-Track Cleanup program strives to make parcels available for reuse as quickly as possible by the transfer of uncontaminated or remediated parcels, the lease of contaminated parcels where cleanup is underway, or the 'early transfer' of contaminated property undergoing cleanup.

  13. Performance of candidate gas turbine abradeable seal materials in high temperature combustion atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Simms, N.J. [Cranfield University, Power Generation Technology Centre, Cranfield, Beds, MK43 0AL (United Kingdom); Norton, J.F. [Cranfield University, Power Generation Technology Centre, Cranfield, Beds, MK43 0AL (United Kingdom); Consultant in Corrosion Science and Technology, Hemel Hempstead, Herts HP1 1SR (United Kingdom); McColvin, G. [Siemens Industrial Turbines Ltd., Lincoln, LN5 7FD (United Kingdom)

    2005-11-01

    The development of abradeable gas turbine seals for higher temperature duties has been the target of an EU-funded R and D project, ADSEALS, with the aim of moving towards seals that can withstand surface temperatures as high as {proportional_to} 1100 C for periods of at least 24,000 h. The ADSEALS project has investigated the manufacturing and performance of a number of alternative materials for the traditional honeycomb seal design and novel alternative designs. This paper reports results from two series of exposure tests carried out to evaluate the oxidation performance of the seal structures in combustion gases and under thermal cycling conditions. These investigations formed one part of the evaluation of seal materials that has been carried out within the ADSEALS project. The first series of three tests, carried out for screening purposes, exposed candidate abradeable seal materials to a simulated natural gas combustion environment at temperatures within the range 1050-1150 C in controlled atmosphere furnaces for periods of up to {proportional_to} 2,500 h with fifteen thermal cycles. The samples were thermally cycled to room temperature on a weekly basis to enable the progress of the degradation to be monitored by mass change and visual observation, as well as allowing samples to be exchanged at planned intervals. The honeycombs were manufactured from PM2000 and Haynes 214. The backing plates for the seal constructions were manufactured from Haynes 214. Some seals contained fillers or had been surface treated (e.g. aluminised). The second series of three tests were carried out in a natural gas fired ribbon furnace facility that allowed up to sixty samples of candidate seal structures (including honeycombs, hollow sphere structures and porous ceramics manufactured from an extended range of materials including Aluchrom YHf, PM2Hf, Haynes 230, IN738LC and MarM247) to be exposed simultaneously to a stream of hot combustion gas. In this case the samples were cooled

  14. Seismic response of high temperature gas-cooled reactor core with block-type fuel, (2)

    International Nuclear Information System (INIS)

    Ikushima, Takeshi; Honma, Toshiaki.

    1980-01-01

    For the aseismic design of a high temperature gas-cooled reactor (HTGR) with block-type fuel, it is necessary to predict the motion and force of core columns and blocks. To reveal column vibration characteristics in three-dimensional space and impact response, column vibration tests were carried out with a scale model of a one-region section (seven columns) of the HTGR core. The results are as follows: (1) the column has a soft spring characteristic based on stacked blocks connected with loose pins, (2) the column has whirling phenomena, (3) the compression spring force simulating the gas pressure has the effect of raising the column resonance frequency, and (4) the vibration behavior of the stacked block column and impact response of the surrounding columns show agreement between experiment and analysis. (author)

  15. Probing Gas Adsorption in Zeolites by Variable-Temperature IR Spectroscopy: An Overview of Current Research.

    Science.gov (United States)

    Garrone, Edoardo; Delgado, Montserrat R; Bonelli, Barbara; Arean, Carlos O

    2017-09-15

    The current state of the art in the application of variable-temperature IR (VTIR) spectroscopy to the study of (i) adsorption sites in zeolites, including dual cation sites; (ii) the structure of adsorption complexes and (iii) gas-solid interaction energy is reviewed. The main focus is placed on the potential use of zeolites for gas separation, purification and transport, but possible extension to the field of heterogeneous catalysis is also envisaged. A critical comparison with classical IR spectroscopy and adsorption calorimetry shows that the main merits of VTIR spectroscopy are (i) its ability to provide simultaneously the spectroscopic signature of the adsorption complex and the standard enthalpy change involved in the adsorption process; and (ii) the enhanced potential of VTIR to be site specific in favorable cases.

  16. Wide-range vortex shedding flowmeter for high-temperature helium gas

    Energy Technology Data Exchange (ETDEWEB)

    Baker, S.P.; Herndon, P.G.; Ennis, R.M. Jr.

    1983-01-01

    The existing design of a commercially available vortex shedding flowmeter (VSFM) was modified and optimized to produce three 4-in. and one 6-in. high-performance VSFMs for measuring helium flow in a gas-cooled fast reactor (GCFR) test loop. The project was undertaken because of the significant economic and performance advantages to be realized by using a single flowmeter capable of covering the 166:1 flow range (at 350/sup 0/C and 45:1 pressure range) of the tests. A detailed calibration in air and helium at the Colorado Engineering Experiment Station showed an accuracy of +-1% of reading for a 100:1 helium flow range and +-1.75% of reading for a 288:1 flow range in both helium and air. At an extended gas temperature of 450/sup 0/C, water cooling was necessary for reliable flowmeter operation.

  17. Modular High Temperature Gas-Cooled Reactor heat source for coal conversion

    International Nuclear Information System (INIS)

    Schleicher, R.W. Jr.; Lewis, A.C.

    1992-09-01

    In the industrial nations, transportable fuels in the form of natural gas and petroleum derivatives constitute a primary energy source nearly equivalent to that consumed for generating electric power. Nations with large coal deposits have the option of coal conversion to meet their transportable fuel demands. But these processes themselves consume huge amounts of energy and produce undesirable combustion by-products. Therefore, this represents a major opportunity to apply nuclear energy for both the environmental and energy conservation reasons. Because the most desirable coal conversion processes take place at 800 degree C or higher, only the High Temperature Gas-Cooled Reactors (HTGRs) have the potential to be adapted to coal conversion processes. This report provides a discussion of this utilization of HTGR reactors

  18. A possible origin of EL6 chondrites from a high temperature-high pressure solar gas

    Energy Technology Data Exchange (ETDEWEB)

    Blander, M. [Argonne National Lab., IL (United States); Unger, L. [Purdue Univ., Westiville, IN (United States). Dept. of Chemistry; Pelton, A.; Eriksson, G. [Ecole Polytechnique, Montreal, PQ (Canada). Dept. of Metallurgy and Materials Engineering

    1994-05-01

    Condensates from a gas of ``solar`` composition were calculated to investigate the origins of EL6 chondrites using a free energy minimization program with a data base for the thermodynamic properties of multicomponent molten silicates as well as for other liquids solids, solid solutions and gaseous species. Because of high volatility of silicon and silica, the high silicon content of metal (2.6 mole %) can only be produced at pressures 10{sup {minus}2} atm at temperatures above 1475 K. At 100--500 atm, a liquid silicate phase crystallizes at a temperature where the silicon content of the metal, ferrosilite content of the enstatite and albite concentration in the plagioclase are close to measured values. In pyrometallurgy, liquid silicates are catalysts for reactions in which Si-O-Si bridging bonds are broken or formed. Thus, one attractive mode for freezing in the compositions of these three phases is disappearance of fluxing liquid. If the plagioclase can continue to react with the nebula without a liquid phase, lower pressures of 10{sup {minus}1} to 1 atm might be possible. Even if the nebula is more reducing than a solar gas, the measured properties of EL6 chondrites might be reconciled with only slightly lower pressures (less than 3X lower). The temperatures would be about the same as indicated in our calculations since the product of the silicon content of the metal and the square of the ferrosilite content of the enstatite constitute a cosmothermometer for the mineral assemblage in EL6 chondrites.

  19. Concept of an inherently-safe high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Ohashi, Hirofumi; Sato, Hiroyuki; Tachibana, Yukio; Kunitomi, Kazuhiko; Ogawa, Masuro

    2012-01-01

    As the challenge to ensure no harmful release of radioactive materials at the accidents by deterministic approach instead to satisfy acceptance criteria or safety goal for risk by probabilistic approach, new concept of advanced reactor, an inherently-safe high temperature gas-cooled reactor, is proposed based on the experience of the operation of the actual High Temperature Gas-cooled Reactor (HTGR) in Japan, High Temperature Engineering Test Reactor (HTTR), and the design of the commercial plant (GTHTR300), utilizing the inherent safety features of the HTGR (i.e., safety features based on physical phenomena). The safety design philosophy of the inherently-safe HTGR for the safety analysis of the radiological consequences is determined as the confinement of radioactive materials is assured by only inherent safety features without engineered safety features, AC power or prompt actions by plant personnel if the design extension conditions occur. Inherent safety features to prevent the loss or degradation of the confinement function are identified. It is proposed not to apply the probabilistic approach for the evaluation of the radiological consequences of the accidents in the safety analysis because no inherent safety features fail for the mitigation of the consequences of the accidents. Consequently, there are no event sequences to harmful release of radioactive materials if the design extension conditions occur in the inherently-safe HTGR concept. The concept and future R and D items for the inherently-safe HTGR are described in this paper.

  20. KINETIC TEMPERATURES OF THE DENSE GAS CLUMPS IN THE ORION KL MOLECULAR CORE

    International Nuclear Information System (INIS)

    Wang, K.-S.; Kuan, Y.-J.; Liu, S.-Y.; Charnley, Steven B.

    2010-01-01

    High angular-resolution images of the J = 18 K -17 K emission of CH 3 CN in the Orion KL molecular core were observed with the Submillimeter Array (SMA). Our high-resolution observations clearly reveal that CH 3 CN emission originates mainly from the Orion Hot Core and the Compact Ridge, both within ∼15'' of the warm and dense part of Orion KL. The clumpy nature of the molecular gas in Orion KL can also be readily seen from our high-resolution SMA images. In addition, a semi-open cavity-like kinematic structure is evident at the location between the Hot Core and the Compact Ridge. We performed excitation analysis with the 'population diagram' method toward the Hot Core, IRc7, and the northern part of the Compact Ridge. Our results disclose a non-uniform temperature structure on small scales in Orion KL, with a range of temperatures from 190-620 K in the Hot Core. Near the Compact Ridge, the temperatures are found to be 170-280 K. Comparable CH 3 CN fractional abundances of 10 -8 to 10 -7 are found around both in the Hot Core and the Compact Ridge. Such high abundances require that a hot gas phase chemistry, probably involving ammonia released from grain mantles, plays an important role in forming these CH 3 CN molecules.

  1. Draft of standard for graphite core components in high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Shibata, Taiju; Sawa, Kazuhiro; Eto, Motokuni; Kunimoto, Eiji; Shiozawa, Shusaku; Oku, Tatsuo; Maruyama, Tadashi

    2010-01-01

    For the design of the graphite components in the High Temperature Engineering Test Reactor (HTTR), the graphite structural design code for the HTTR etc. were applied. However, general standard systems for the High Temperature Gas-cooled Reactor (HTGR) have not been established yet. The authors had studied on the technical issues which is necessary for the establishment of a general standard system for the graphite components in the HTGR. The results of the study were documented and discussed at a 'Special committee on research on preparation for codes for graphite components in HTGR' at Atomic Energy Society of Japan (AESJ). As a result, 'Draft of Standard for Graphite Core Components in High Temperature Gas-cooled Reactor.' was established. In the draft standard, the graphite components are classified three categories (A, B and C) in the standpoints of safety functions and possibility of replacement. For the components in the each class, design standard, material and product standards, and in-service inspection and maintenance standard are determined. As an appendix of the design standard, the graphical expressions of material property data of 1G-110 graphite as a function of fast neutron fluence are expressed. The graphical expressions were determined through the interpolation and extrapolation of the irradiated data. (author)

  2. Comparison of high temperature gas particulate collectors for low level radwaste incinerator volume reduction systems

    International Nuclear Information System (INIS)

    Moscardini, R.L.; Johnston, J.R.; Waters, R.M.; Zievers, J.F.

    1983-01-01

    Incinerator system off-gases must be treated to prevent the release of particulates, noxious gases and radioactive elements to the environment. Fabric filters, venturi scrubbers, cyclone separators, an ceramic or metal filter candles have been used for particulate removal. Dry high temperature particulate collectors have the advantage of not creating additional liquid wastes. This paper presents a graphical comparison of different methods for filtering particles from high temperature incineration system off-gases. Eight methods of off-gas handling are compared. A much larger group may be present, but some judicious selection of different, but related systems was done for this paper based on experience with the Combustion Engineering Waste Incineration System (CE/WIS) Prototype. The eight types are: Inertial Devices, Electrostatic Precipitators (ESP), Standard Fabric Bags, Woven Ceramic Bags, Granular Beds, Sintered Metal Tubes, Felted Ceramic Bags and Ceramic Filter Candles. For high temperature LLRW particulate collection in incinerator off-gas systems, ceramic filter candles are the best overall choice

  3. OPTIMAL SYSNTHESIS PROCESSES OF LOW-TEMPERATURE CONDENSATION ASSOCIATED OIL GAS PLANT REFRIGERATION SYSTEM

    Directory of Open Access Journals (Sweden)

    O. Ostapenko

    2015-10-01

    Full Text Available Design of modern high-efficient systems is a key priority for the Energy Sector of Ukraine. The cooling technological streams of gas and oil refineries, including air coolers, water cooling and refrigeration systems for specific refrigerants are the objectives of the present study. Improvement of the refrigeration unit with refrigerant separation into fractions is mandatory in order to increase cooling capacity, lowering the boiling point of coolant and increasing the coefficient of target hydrocarbons extraction from the associated gas flow. In this paper it is shown that cooling temperature plays significant role in low-temperature condensation process. Two operation modes for refrigeration unit were proposed: permanent, in which the concentration of the refrigerant mixture does not change and dynamic, in which the concentration of refrigerant mixtures depends on the ambient temperature. Based on the analysis of exergy losses the optimal concentration of refrigerant mixtures propane/ethane for both modes of operation of the refrigeration unit has been determined. On the basis of the conducted pinch-analysis the modification of refrigeration unit with refrigerant separation into fractions was developed. Additional recuperative heat exchangers for utilization heat were added to the scheme. Several important measures to increase the mass flow rate of refrigerant through the second section of the refrigeration centrifugal compressor from 22.5 to 25 kg/s without violating the agreed operational mode of the compressor sections were implemented.

  4. Discussion on Design Transients of Pebble-bed High Temperature Gas-cooled Reactor

    International Nuclear Information System (INIS)

    Wang Yan; Li Fu; Zheng Yanhua

    2014-01-01

    In order to assure high quality for the components and their supports in the reactor coolant system, etc., some thermal-hydraulic transient conditions will be selected and researched for equipment design evaluation to satisfy the requirements ASME code, which are based on the conservative estimates of the magnitude and frequency of the temperature and pressure transients resulting from various operating conditions in the plant. In the mature design on pressurized water reactor, five conditions are considered. For the developing advanced pebble-bed high temperature gas-cooled reactor(HTGR), its design and operation has much difference with other reactors, so the transients of the pebble-bed high temperature gas-cooled reactor have distinctive characteristics. In this paper, the possible design transients of the pebble-bed HTGR will be discussed, and the frequency of design transients for equipment fatigue analysis and stress analysis due to cyclic stresses is also studied. The results will provide support for the design and construct of the pebble-bed HTGR. (author)

  5. Safety design philosophy of gas turbine high temperature reactor (GTHTR300)

    International Nuclear Information System (INIS)

    Katanishi, Shoji; Kunitomi, Kazuhiko

    2003-01-01

    Japan Atomic Energy Research Institute (JAERI) has been developing design studies of the Gas Turbine High Temperature Reactor (GTHTR300). The original safety design philosophy has also been discussed and fixed for the GTHTR300 based on the experience of the High Temperature Engineering Test Reactor (HTTR) of JAERI which is the first High Temperature Gas-cooled Reactor (HTGR) in Japan. One of the unique feature of the safety philosophy of the GTHTR300 is that a depressurization accident induced by a large pipe break is postulated as a design basis accident in order to show the high level of safety characteristics, though its probability of occurrence is lower than the probability range of design basis accident. Another feature of safety design is to adopt a double confinement that is one of the original concepts for the GTHTR300. By using a double confinement, a feasibility of safety design without containment vessel was clarified even in case of the depressurization accident. The safety design philosophies for passive cooling system, reactor shutdown system, and so on were determined. The methodology for the safety evaluation, such as safety criteria and selection of events to be evaluated by using estimation of probability of occurrence, were also discussed and determined. This article describes the safety design philosophy and some results of preliminary evaluations which were conducted in order to clarify the feasibility of original safety design of the GTHTR300. The present study is entrusted from Ministry of Education, Culture, Sports, Science and Technology of Japan. (author)

  6. Survey on Cooled-Vessel Designs in High Temperature Gas-Cooled Reactors

    International Nuclear Information System (INIS)

    Kim, Min-Hwan; Lee, Won-Jae

    2006-01-01

    The core outlet temperature of the coolant in the high temperature gas-cooled reactors (HTGR) has been increased to improve the overall efficiency of their electricity generation by using the Brayton cycle or their nuclear hydrogen production by using thermo-chemical processes. The increase of the outlet temperature accompanies an increase of the coolant inlet temperature. A high coolant inlet temperature results in an increase of the reactor pressure vessel (RPV) operation temperature. The conventional steels, proven vessel material in light water reactors, cannot be used as materials for the RPV in the elevated temperatures which necessitate its design to account for the creep effects. Some ferritic or martensitic steels like 2 1/4Cr-1Mo and 9Cr-1Mo-V are very well established creep resistant materials for a temperature range of 400 to 550 C. Although these materials have been used in a chemical plant, there is limited experience with using these materials in nuclear reactors. Even though the 2 1/4Cr-1Mo steel was used to manufacture the RPV for HTR-10 of Japan Atomic Energy Agency(JAEA), a large RPV has not been manufactured by using this material or 9Cr-1Mo-V steel. Due to not only its difficulties in manufacturing but also its high cost, the JAEA determined that they would exclude these materials from the GTHTR design. For the above reasons, KAERI has been considering a cooled-vessel design as an option for the RPV design of a NHDD plant (Nuclear Hydrogen Development and Demonstration). In this study, we surveyed several HTGRs, which adopt the cooled-vessel concept for their RPV design, and discussed their design characteristics. The survey results in design considerations for the NHDD cooled-vessel design

  7. Thermal-hydraulic Analysis of High-temperature Cover Gas Region in STELLA-2

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Youngchul; Son, Seok-Kwon; Yoon, Jung; Eoh, Jaehyuk; Jeong, Ji-Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    The first phase of the program was focused on the key sodium component tests, and the second one has been concentrated on the sodium thermal-hydraulic integral effect test (STELLA-2). Based on its platform, simulation of the PGSFR transient will be made to evaluate plant dynamic behaviors as well as to demonstrate decay heat removal performance. Therefore, most design features of PGSFR have been modeled in STELLA-2 as closely as possible. The similarities of temperature and pressure between the model (STELLA-2) and the prototype (PGSFR) have been well preserved to reflect thermal-hydraulic behavior with natural convection as well as heat transfer between structure and sodium coolant inside the model reactor vessel (RV). For this reason, structural integrity of the entire test section should be confirmed as in the prototype. In particular, since the model reactor head in STELLA-2 supports key components and internal structures, its structural integrity exposed to high-temperature cover gas region should be confirmed. In order to reduce thermal radiation heat transfer from the hot sodium pool during normal operation, a dedicated insulation layer has been installed at the downward surface of the model reactor head to prevent direct heat flux from the sodium free surface at 545 .deg. C. Three-dimensional conjugate heat transfer analyses for the full-shape geometry of the upper part of the model reactor vessel in STELLA-2 have been carried out. Based on the results, steady-state temperature distributions in the cover gas region and the model reactor head itself have been obtained and the design requirement in temperature of the model reactor head has been newly proposed to be 350 .deg. C. For any elevated temperature conditions in STELLA-2, it was confirmed that the model reactor head generally satisfied the requirement. The CFD database constructed from this study will be used to optimize geometric parameters such as thicknesses and/or types of the insulator.

  8. One-Way Flow of a Rarefied Gas Induced in a Circular Pipe with a Periodic Temperature Distribution

    National Research Council Canada - National Science Library

    Aoki, K

    2000-01-01

    The steady behavior of a rarefied gas in a circular pipe with a saw-like temperature distribution increasing and decreasing periodically in the direction of the pipe axis is investigated numerically...

  9. Diode Laser Sensor for Gas Temperature and H2O Concentration in a Scramjet Combustor Using Wavelength Modulation Spectroscopy (Postprint)

    National Research Council Canada - National Science Library

    Rieker, Gregory B; Li, Jonathan T; Jeffries, Jay B; Mathur, Tarun; Gruber, Mark R; Carter, Campbell D

    2005-01-01

    A diode laser absorption sensor which probes three spectral features of water vapor in the near infrared region to infer gas temperature and water vapor concentration near the exit of a scramjet combustor is presented...

  10. Temperature Gradient Effect on Gas Discrimination Power of a Metal-Oxide Thin-Film Sensor Microarray

    Directory of Open Access Journals (Sweden)

    Joachim Goschnick

    2004-05-01

    Full Text Available Abstract: The paper presents results concerning the effect of spatial inhomogeneous operating temperature on the gas discrimination power of a gas-sensor microarray, with the latter based on a thin SnO2 film employed in the KAMINA electronic nose. Three different temperature distributions over the substrate are discussed: a nearly homogeneous one and two temperature gradients, equal to approx. 3.3 oC/mm and 6.7 oC/mm, applied across the sensor elements (segments of the array. The gas discrimination power of the microarray is judged by using the Mahalanobis distance in the LDA (Linear Discrimination Analysis coordinate system between the data clusters obtained by the response of the microarray to four target vapors: ethanol, acetone, propanol and ammonia. It is shown that the application of a temperature gradient increases the gas discrimination power of the microarray by up to 35 %.

  11. Fuel-Cycle and Nuclear Material Disposition Issues Associated with High-Temperature Gas Reactors

    International Nuclear Information System (INIS)

    Shropshire, D.E.; Herring, J.S.

    2004-01-01

    The objective of this paper is to facilitate a better understanding of the fuel-cycle and nuclear material disposition issues associated with high-temperature gas reactors (HTGRs). This paper reviews the nuclear fuel cycles supporting early and present day gas reactors, and identifies challenges for the advanced fuel cycles and waste management systems supporting the next generation of HTGRs, including the Very High Temperature Reactor, which is under development in the Generation IV Program. The earliest gas-cooled reactors were the carbon dioxide (CO2)-cooled reactors. Historical experience is available from over 1,000 reactor-years of operation from 52 electricity-generating, CO2-cooled reactor plants that were placed in operation worldwide. Following the CO2 reactor development, seven HTGR plants were built and operated. The HTGR came about from the combination of helium coolant and graphite moderator. Helium was used instead of air or CO2 as the coolant. The helium gas has a significant technical base due to the experience gained in the United States from the 40-MWe Peach Bottom and 330-MWe Fort St. Vrain reactors designed by General Atomics. Germany also built and operated the 15-MWe Arbeitsgemeinschaft Versuchsreaktor (AVR) and the 300-MWe Thorium High-Temperature Reactor (THTR) power plants. The AVR, THTR, Peach Bottom and Fort St. Vrain all used fuel containing thorium in various forms (i.e., carbides, oxides, thorium particles) and mixtures with highly enriched uranium. The operational experience gained from these early gas reactors can be applied to the next generation of nuclear power systems. HTGR systems are being developed in South Africa, China, Japan, the United States, and Russia. Elements of the HTGR system evaluated included fuel demands on uranium ore mining and milling, conversion, enrichment services, and fuel fabrication; fuel management in-core; spent fuel characteristics affecting fuel recycling and refabrication, fuel handling, interim

  12. Sustainability and Efficiency Improvements of Gas-Cooled High Temperature Reactors

    International Nuclear Information System (INIS)

    Marmier, Alain

    2012-01-01

    high temperature irradiation to high burn-ups with fission gas release measurements. To this end, the HFR-EU1 fuel irradiation in the High Flux Reactor (HFR) Petten (2006-2010) explored the potential for high performance and high burn-up of existing German fuel (3 pebbles produced for the AVR reactor at the German research centre Juelich) and newly produced Chinese fuel (2 pebbles produced by INET for use in the HTR-10 test reactor in China). These five pebbles were irradiated for 445 days in separately controlled capsules, while the fission gas release was monitored by gamma spectrometry thus enabling evaluation of the characteristic release over birth fraction, indicative for the health of the fuel. In none of the pebbles, abnormally increased fission gas release was observed indicating that all of the approx. 45,000 coated particles in the pebbles had remained intact. The results presented in this thesis cover the first 332 days of irradiation. While HFR-EU1 was dedicated to a particularly high burn-up, HFR-EU1bis, performed between 2004 and 2005, investigated extremely high temperature for steady-state conditions. The comparison of both experiments confirms that temperature plays a decisive part in fuel performance and integrity. The peak fuel temperature in pebbles can be lowered with the so-called w allpaper fuel , in which the coated fuel particles are arranged in a spherical shell within a pebble. This wallpaper concept also enhances neutronic performance through improved neutron economy, resulting in reduced fissile material and/or enrichment needs or providing the potential to achieve higher burn-up. To quantify these improvements, calculations were performed using the Monte Carlo neutron transport and depletion codes MCNP/MCB (to assess conversion ratio, temperature coefficient of reactivity and neutron multiplication) and PANTHERMIX (for fuel cycle in steady state conditions and loss of coolant accident calculations). Based on PANTHERMIX steady

  13. Testing and analyses of a high temperature duct for gas-cooled reactors

    International Nuclear Information System (INIS)

    Black, W.E.; Roberge, A.; Felten, P.; Bastien, D.

    1979-01-01

    A 0.6 scale model of a steam cycle gas-cooled reactor high temperature duct was tested in a closed loop helium facility. The object of the test series was to determine: 1) the thermal effects of gas permeation within the thermal barrier, 2) the plastic deformation of the metallic components, and 3) the thermal performance of the fibrous insulation. A series of tests was performed with thermal cyclings from 100 0 C to 760 0 C at 50 atmospheres until the system thermal performance had stabilized hence enabling predictions for the reactor life. Additional tests were made to assess permeation by deliberately simulating sealing weld failures thereby allowing gas flow by-pass within the primary thermal barrier. After 100 cycles the entire primary structure was found to have performed without structural failure. Due to high pressures exerted by the insulation on the cover plates and a design oversight, the thin seal sheets were unable to expand in an anticipated manner. Local buckling resulted. The insulation retained an acceptable degree of resiliency. However, some fiber damage was observed within both the high and low temperature insulation blankets. A thermal analysis was conducted to correlate the hot duct heat transfer results with those obtained from the analytical techniques used for the HTGR design using a computer thermal model representative of the duct and test setup. The thermal performance of the insulation, the temperature gradient through the structural components, the heating load to the cooling system and the permeation flow effect on heat transfer were verified. Exellent correlation between the experimental data and the analytical techniques were obtained

  14. Numerical evaluation of flow through a prismatic very high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Barros Filho, Jose A.; Santos, Andre A.C.; Navarro, Moyses A.; Ribeiro, Felipe Lopes

    2011-01-01

    The High-temperature Gas-cooled reactor (HTGR) is a Next Generation Nuclear System that has a good chance to be used as energy generation source in the near future owing to its potential capacity to supply hydrogen without greenhouse gas emission for the future humanity. Recently, improvements in the HTGR design led to the Very High Temperature Reactor (VHTR) concept in which the outlet temperature of the coolant gas reaches to 1000 deg C increasing the efficiency of the hydrogen and electricity generation. Among the core concepts emerging in the VHTR development stands out the prismatic block which uses coated fuel microspheres named TRISO pressed into cylinders and assembled in hexagonal graphite blocks staked to form columns. The graphite blocks contain flow channels around the fuel cylinders for the helium coolant. In this study an analysis is performed using the CFD code CFX 13.0 on a prismatic fuel assembly in order to investigate its thermo-fluid dynamic performance. The simulations were made in a 1/12 fuel element model of the GT-MHR design which was developed by General Atomics. A numerical mesh verification process based on the Grid Convergence Index (GCI) was performed using five progressively refined meshes to assess the numerical uncertainty of the simulation and determine adequate mesh parameters. An analysis was also performed to evaluate different methods to define the inlet and outlet boundary conditions. In this study simulations of models with and without inlet and outlet plena were compared, showing that the presence of the plena offers a more realistic flow distribution. (author)

  15. Binary and ternary gas mixtures with temperature enhanced diffuse glow discharge characteristics for use in closing switches

    Science.gov (United States)

    Christophorou, L.G.; Hunter, S.R.

    1990-06-26

    An improvement to the gas mixture used in diffuse glow discharge closing switches is disclosed which includes binary and ternary gas mixtures which are formulated to exhibit decreasing electron attachment with increasing temperature. This increases the efficiency of the conductance of the glow discharge and further inhibits the formation of an arc. 11 figs.

  16. Recovery of perchloroethylene scrubbing medium generated in the refabrication of high-temperature gas-cooled reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Judd, M.S.; Van Cleve, J.E. Jr.; Rainey, W.T. Jr.

    1976-11-01

    During the refabrication of high-temperature gas-cooled reactor (HTGR) fuel, perchloroethylene (C/sub 2/Cl/sub 4/) is used as the nonmoderating scrubbing medium to remove condensable hydrocarbons, carbon soot, and uranium-bearing particulates from the off-gas streams. The process by which the contaminated perchloroethylene is recycled is discussed.

  17. Modeling the effects of temperature and relative humidity on gas exchange of prickly pear cactus (Opuntia spp.) stems

    NARCIS (Netherlands)

    Guevara-Arauza, J.C.; Yahia, E.M.; Cedeno, L.; Tijskens, L.M.M.

    2006-01-01

    A model to estimate gas profile of modified atmosphere packaged (MAP) prickly pear cactus stems was developed and calibrated. The model describes the transient gas exchange taking in consideration the effect of temperature (T) and relative humidity (RH) on film permeability (FPgas), respiration rate

  18. Recovery of perchloroethylene scrubbing medium generated in the refabrication of high-temperature gas-cooled reactor fuel

    International Nuclear Information System (INIS)

    Judd, M.S.; Van Cleve, J.E. Jr.; Rainey, W.T. Jr.

    1976-11-01

    During the refabrication of high-temperature gas-cooled reactor (HTGR) fuel, perchloroethylene (C 2 Cl 4 ) is used as the nonmoderating scrubbing medium to remove condensable hydrocarbons, carbon soot, and uranium-bearing particulates from the off-gas streams. The process by which the contaminated perchloroethylene is recycled is discussed

  19. An analytical description of the low temperature behaviour of a weakly interacting Bose gas

    International Nuclear Information System (INIS)

    Su Guozhen; Chen Lixuan; Chen Jincan

    2004-01-01

    An analytical description of the low temperature behaviour of a trapped interacting Bose gas is presented by using a simple approach that is based on the principle of the constancy of chemical potentials in equilibrium and the local-density approximation. Several thermodynamic quantities, which include the ground-state fraction, chemical potential, total energy, entropy and heat capacity, are derived analytically. It is shown that the results obtained here are in excellent agreement with the experimental data and the theoretical predictions based on the numerical calculation. Meanwhile, by selecting a suitable variable, the divergent problem existing in some papers is solved

  20. Conceptual design study of high temperature gas-cooled reactor for plutonium incineration

    International Nuclear Information System (INIS)

    Goto, Minoru

    2013-01-01

    JAEA has started a conceptual design study of a Pu burner HTGR, which is called CBHTR (Clean Burn High Temperature gas-cooled Reactor). CBHTR’s fuel is TRISO-coated fuel particle with PuO 2 -YSZ (Yttria- Stabilized Zirconia) kernel, which increase proliferation resistance, safety of geological disposal, and Pu incineration. CBHTR can decrease Puf ratio from 60% to 20% with 520 GWd/t. In the future, 15% of electricity capacity is employed by 7 of CBHTRs and 59 of U-HTRs. JAEA has a R and D plan of manufacturing technology of TRISO-coated fuel with PuO 2 -YSZ kernel