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1

National SCADA Test Bed Consequence Modeling Tool | Department...  

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

National SCADA Test Bed Consequence Modeling Tool National SCADA Test Bed Consequence Modeling Tool This document presents a consequence modeling tool that provides, for asset...

2

Pebble Bed Reactor Dust Production Model  

SciTech Connect

The operation of pebble bed reactors, including fuel circulation, can generate graphite dust, which in turn could be a concern for internal components; and to the near field in the remote event of a break in the coolant circuits. The design of the reactor system must, therefore, take the dust into account and the operation must include contingencies for dust removal and for mitigation of potential releases. Such planning requires a proper assessment of the dust inventory. This paper presents a predictive model of dust generation in an operating pebble bed with recirculating fuel. In this preliminary work the production model is based on the use of the assumption of proportionality between the dust production and the normal force and distance traveled. The model developed in this work uses the slip distances and the inter-pebble forces computed by the authors’ PEBBLES. The code, based on the discrete element method, simulates the relevant static and kinetic friction interactions between the pebbles as well as the recirculation of the pebbles through the reactor vessel. The interaction between pebbles and walls of the reactor vat is treated using the same approach. The amount of dust produced is proportional to the wear coefficient for adhesive wear (taken from literature) and to the slip volume, the product of the contact area and the slip distance. The paper will compare the predicted volume with the measured production rates. The simulation tallies the dust production based on the location of creation. Two peak production zones from intra pebble forces are predicted within the bed. The first zone is located near the pebble inlet chute due to the speed of the dropping pebbles. The second peak zone occurs lower in the reactor with increased pebble contact force due to the weight of supported pebbles. This paper presents the first use of a Discrete Element Method simulation of pebble bed dust production.

Abderrafi M. Ougouag; Joshua J. Cogliati

2008-09-01T23:59:59.000Z

3

COMPUTATIONAL MODELING OF CIRCULATING FLUIDIZED BED REACTORS  

Science Conference Proceedings (OSTI)

Details of numerical simulations of two-phase gas-solid turbulent flow in the riser section of Circulating Fluidized Bed Reactor (CFBR) using Computational Fluid Dynamics (CFD) technique are reported. Two CFBR riser configurations are considered and modeled. Each of these two riser models consist of inlet, exit, connecting elbows and a main pipe. Both riser configurations are cylindrical and have the same diameter but differ in their inlet lengths and main pipe height to enable investigation of riser geometrical scaling effects. In addition, two types of solid particles are exploited in the solid phase of the two-phase gas-solid riser flow simulations to study the influence of solid loading ratio on flow patterns. The gaseous phase in the two-phase flow is represented by standard atmospheric air. The CFD-based FLUENT software is employed to obtain steady state and transient solutions for flow modulations in the riser. The physical dimensions, types and numbers of computation meshes, and solution methodology utilized in the present work are stated. Flow parameters, such as static and dynamic pressure, species velocity, and volume fractions are monitored and analyzed. The differences in the computational results between the two models, under steady and transient conditions, are compared, contrasted, and discussed.

Ibrahim, Essam A

2013-01-09T23:59:59.000Z

4

MCNP4B Modeling of Pebble-Bed Reactors  

E-Print Network (OSTI)

The applicability of the Monte Carlo code MCNP4B to the neutronic modeling of pebble-bed reactors was investigated. A modeling methodology was developed based on an analysis of critical experiments carried out at the ...

Lebenhaft, Julian Robert

2001-10-15T23:59:59.000Z

5

Computational fluid dynamic modeling of fluidized-bed polymerization reactors  

SciTech Connect

Polyethylene is one of the most widely used plastics, and over 60 million tons are produced worldwide every year. Polyethylene is obtained by the catalytic polymerization of ethylene in gas and liquid phase reactors. The gas phase processes are more advantageous, and use fluidized-bed reactors for production of polyethylene. Since they operate so close to the melting point of the polymer, agglomeration is an operational concern in all slurry and gas polymerization processes. Electrostatics and hot spot formation are the main factors that contribute to agglomeration in gas-phase processes. Electrostatic charges in gas phase polymerization fluidized bed reactors are known to influence the bed hydrodynamics, particle elutriation, bubble size, bubble shape etc. Accumulation of electrostatic charges in the fluidized-bed can lead to operational issues. In this work a first-principles electrostatic model is developed and coupled with a multi-fluid computational fluid dynamic (CFD) model to understand the effect of electrostatics on the dynamics of a fluidized-bed. The multi-fluid CFD model for gas-particle flow is based on the kinetic theory of granular flows closures. The electrostatic model is developed based on a fixed, size-dependent charge for each type of particle (catalyst, polymer, polymer fines) phase. The combined CFD model is first verified using simple test cases, validated with experiments and applied to a pilot-scale polymerization fluidized-bed reactor. The CFD model reproduced qualitative trends in particle segregation and entrainment due to electrostatic charges observed in experiments. For the scale up of fluidized bed reactor, filtered models are developed and implemented on pilot scale reactor.

Rokkam, Ram [Ames Laboratory

2012-11-02T23:59:59.000Z

6

Liquid-fluidized-bed heat exchanger flow distribution models  

DOE Green Energy (OSTI)

Allied Chemical Corporation at the Idaho National Engineering Laboratory is developing liquid-fluidized-bed shell-and-tube heat exchangers for geothermal applications. Sand fluidized by geothermal water on the shell side prevents scaling and increases heat transfer coefficients over conventional heat exchangers. Tests were conducted on two instrumented fluidized-bed heat exchanger models, constructed primarily of plexiglass, which differ in tube bundle orientation. One contains a horizontal bundle and the other a vertical tube bundle. Plexiglass construction allowed visual observation of flow patterns. The vertical model proved to have more uniform flow distribution and higher heat transfer coefficients than the horizontal model. The horizontal heat exchanger experienced piling on top of the tubes and areas of poor fluidization existed in the bed. Geometric considerations show that a horizontal design is more conducive to large flow rates than a vertical design. New design concepts for both vertical and horizontal assemblies and recommendations for further developmental work are presented.

Cole, L.T.; Allen, C.A.

1979-01-01T23:59:59.000Z

7

Mathematical modeling of methane flow in coal beds  

Science Conference Proceedings (OSTI)

The paper offers to describe the free and occlude gas filtration and diffusion in a coal bed by a numerical model in the form of a system of heterogenous parabolic equations. The gas flow as a shock and depression wave has been considered, and the desorption isotherm conditions for these waves to arise in a coal bed are formulated. By analyzing experimental data on cavities generated by a sudden coal and gas outburst, the authors construct the numerical model describing gas and coal mix outflow in a mine.

Fedorov, A.V.; Fedorchenko, I.A. [Russian Academy of Sciences, Novosibirsk (Russian Federation)

2009-01-15T23:59:59.000Z

8

Probabilistic consequence model of accidenal or intentional chemical releases.  

SciTech Connect

In this work, general methodologies for evaluating the impacts of large-scale toxic chemical releases are proposed. The potential numbers of injuries and fatalities, the numbers of hospital beds, and the geographical areas rendered unusable during and some time after the occurrence and passage of a toxic plume are estimated on a probabilistic basis. To arrive at these estimates, historical accidental release data, maximum stored volumes, and meteorological data were used as inputs into the SLAB accidental chemical release model. Toxic gas footprints from the model were overlaid onto detailed population and hospital distribution data for a given region to estimate potential impacts. Output results are in the form of a generic statistical distribution of injuries and fatalities associated with specific toxic chemicals and regions of the United States. In addition, indoor hazards were estimated, so the model can provide contingency plans for either shelter-in-place or evacuation when an accident occurs. The stochastic distributions of injuries and fatalities are being used in a U.S. Department of Homeland Security-sponsored decision support system as source terms for a Monte Carlo simulation that evaluates potential measures for mitigating terrorist threats. This information can also be used to support the formulation of evacuation plans and to estimate damage and cleanup costs.

Chang, Y.-S.; Samsa, M. E.; Folga, S. M.; Hartmann, H. M.

2008-06-02T23:59:59.000Z

9

Evaluation of a simulation model in predicting the drying parameters for deep-bed paddy drying  

Science Conference Proceedings (OSTI)

A simulation model for deep-bed batch drying of paddy was developed to predict the profiles of grain moisture content, grain temperature, air temperature and air humidity during the drying process. In order to evaluate the validity of this model, a laboratory-scale ... Keywords: Deep-bed, Energy optimization, Paddy, Simulation model

Dariush Zare; Guangnan Chen

2009-08-01T23:59:59.000Z

10

Stochastic Models for Transport in a Fluidized Bed  

E-Print Network (OSTI)

In this paper we study stochastic models for the transport of particles in a fluidized bed reactor, and compute the associated residence time distribution (RTD). Our main model is basically a diffusion process in [0; A] with reflecting/absorbing boundary conditions, modified by allowing jumps to the origin as a result of transport of particles in the wake of rising fluidization bubbles. We study discrete time birth-death Markov chains as approximations to our diffusion model. For these we can compute the particle distribution inside the reactor as well as the RTD by simple and fast matrix calculations. It turns out that discretization of the reactor into a moderate number of segments already gives excellent numerical approximations to the continuous model. From the forward equation for the particle distribution in the discrete model we obtain in the diffusion limit a partial differential equation for the particle density p(t; x) @ @t p(t; x) = 1 2 @ 2 @x 2 [D(x)p(t; x)] \\Gamma @ @...

H. G. Dehling; A. C. Hoffmann; H. W. Stuut

1998-01-01T23:59:59.000Z

11

Modelling gas-liquid flow in tricle-bed reactors.  

E-Print Network (OSTI)

??The performance of a trickle-bed reactor is affected, not only by reaction kinetics, pressure, and temperature, but also by reactor hydrodynamics, which are commonly described… (more)

Lappalainen, Katja

2009-01-01T23:59:59.000Z

12

Sodium/water pool-deposit bed model of the CONACS code. [LMFBR  

SciTech Connect

A new Pool-Bed model of the CONACS (Containment Analysis Code System) code represents a major advance over the pool models of other containment analysis code (NABE code of France, CEDAN code of Japan and CACECO and CONTAIN codes of the United States). This new model advances pool-bed modeling because of the number of significant materials and processes which are included with appropriate rigor. This CONACS pool-bed model maintains material balances for eight chemical species (C, H/sub 2/O, Na, NaH, Na/sub 2/O, Na/sub 2/O/sub 2/, Na/sub 2/CO/sub 3/ and NaOH) that collect in the stationary liquid pool on the floor and in the desposit bed on the elevated shelf of the standard CONACS analysis cell.

Peak, R.D.

1983-12-17T23:59:59.000Z

13

Demonstration of an advanced circulation fludized bed coal combustor phase 1: Cold model study. Final report  

Science Conference Proceedings (OSTI)

It was found that there was a strong dependence of the density profile on the secondary air injection location and that there was a pronounced solid separation from the conveying gas, due to the swirl motion. Furthermore, the swirl motion generated strong internal circulation patterns and higher slip velocities than in the case of nonswirl motion as in an ordinary circulating fluidized bed. Radial solids flux profiles were measured at different axial locations. The general radial profile in a swirling circulating fluidized bed indicated an increased downward flow of solids near the bed walls, and strong variations in radial profiles along the axial height. For swirl numbers less than 0.9, which is typical for swirling circulating fluidized beds, there is no significant increase in erosion due to swirl motion inside the bed. Pending further investigation of swirl motion with combustion, at least from our cold model studies, no disadvantages due to the introduction of swirl motion were discovered.

Govind, R. [Cincinnati Univ., OH (United States). Dept. of Chemical Engineering

1993-03-20T23:59:59.000Z

14

Design report on SCDAP/RELAP5 model improvements - debris bed and molten pool behavior  

SciTech Connect

the SCDAP/RELAP5/MOD3 computer code is designed to describe the overall reactor coolant system thermal-hydraulic response, core damage progression, and in combination with VICTORIA, fission product release and transport during severe accidents. Improvements for existing debris bed and molten pool models in the SCDAP/RELAP5/MOD3.1 code are described in this report. Model improvements to address (a) debris bed formation, heating, and melting; (b) molten pool formation and growth; and (c) molten pool crust failure are discussed. Relevant data, existing models, proposed modeling changes, and the anticipated impact of the changes are discussed. Recommendations for the assessment of improved models are provided.

Allison, C.M.; Rempe, J.L.; Chavez, S.A.

1994-11-01T23:59:59.000Z

15

Modeling of solid-side mass transfer in desiccant particle beds  

DOE Green Energy (OSTI)

A model is proposed for heat and mass transfer in a packed bed of desiccant particles and accounts for both Knudsen and surface diffusion within the particles. Using the model, predictions are made for the response of thin beds of silica gel particles to a step change in air inlet conditions compared to mental results. The predictions are found to be satisfactory and, in general, superior to those of pseudogas-side controlled models commonly used for the design of desiccant dehumidifiers for solar air conditioning application.

Pesaran, A.A.; Mills, A.F.

1984-02-01T23:59:59.000Z

16

Mathematical modelling of processes of reject water treatment in moving bed bioreactor  

Science Conference Proceedings (OSTI)

Efficient treatment of reject water originating from sludge digestion process was achieved by implementing a moving bed bioreactor. Since the ongoing processes in the reactor were unclear, model development was chosen in order to map them. To describe ... Keywords: ANAMMOX, MBBR, nitrogen removal, reject water, steady-state simulation

Viola Somogyi; Bence Fazekas; Endre Domokos; Ákos Rédey

2008-11-01T23:59:59.000Z

17

Two stage fluid bed-plasma gasification process for solid waste valorisation: Technical review and preliminary thermodynamic modelling of sulphur emissions  

Science Conference Proceedings (OSTI)

Highlights: Black-Right-Pointing-Pointer We investigate sulphur during MSW gasification within a fluid bed-plasma process. Black-Right-Pointing-Pointer We review the literature on the feed, sulphur and process principles therein. Black-Right-Pointing-Pointer The need for research in this area was identified. Black-Right-Pointing-Pointer We perform thermodynamic modelling of the fluid bed stage. Black-Right-Pointing-Pointer Initial findings indicate the prominence of solid phase sulphur. - Abstract: Gasification of solid waste for energy has significant potential given an abundant feed supply and strong policy drivers. Nonetheless, significant ambiguities in the knowledge base are apparent. Consequently this study investigates sulphur mechanisms within a novel two stage fluid bed-plasma gasification process. This paper includes a detailed review of gasification and plasma fundamentals in relation to the specific process, along with insight on MSW based feedstock properties and sulphur pollutant therein. As a first step to understanding sulphur partitioning and speciation within the process, thermodynamic modelling of the fluid bed stage has been performed. Preliminary findings, supported by plant experience, indicate the prominence of solid phase sulphur species (as opposed to H{sub 2}S) - Na and K based species in particular. Work is underway to further investigate and validate this.

Morrin, Shane, E-mail: shane.morrin@ucl.ac.uk [Department of Chemical Engineering, University College London, London, WC1E 7JE (United Kingdom); Advanced Plasma Power, South Marston Business park, Swindon, SN3 4DE (United Kingdom); Lettieri, Paola, E-mail: p.lettieri@ucl.ac.uk [Department of Chemical Engineering, University College London, London, WC1E 7JE (United Kingdom); Chapman, Chris, E-mail: chris.chapman@app-uk.com [Advanced Plasma Power, South Marston Business park, Swindon, SN3 4DE (United Kingdom); Mazzei, Luca, E-mail: l.mazzei@ucl.ac.uk [Department of Chemical Engineering, University College London, London, WC1E 7JE (United Kingdom)

2012-04-15T23:59:59.000Z

18

MCNP4B modeling of pebble-bed reactors  

E-Print Network (OSTI)

The applicability of the Monte Carlo code MCNP4B to the neutronic modeling of pebblebed reactors was investigated. A modeling methodology was developed based on an analysis of critical experiments carried out at the ...

Lebenhaft, Julian R. (Julian Robert), 1954-

2002-01-01T23:59:59.000Z

19

Numerical modeling of interaction of a current with a circular cylinder near a rigid bed  

Science Conference Proceedings (OSTI)

The numerical modeling of 2D turbulent flow around a smooth horizontal circular cylinder near a rigid bed with gap ratio G/D=0.3 at Reynolds number Re"D=9500 is investigated. Ansys^(R) 10.0-FLOTRAN program package is used to solve the governing equations ... Keywords: Circular cylinder, Numerical model, Particle image velocimetry, Steady flow, Strouhal number, Velocity field

M. Salih Kirkgoz; A. Alper Oner; M. Sami Akoz

2009-11-01T23:59:59.000Z

20

Unstructured finite volume discretisation of bed friction and convective flux in solute transport models linked to the shallow water equations  

Science Conference Proceedings (OSTI)

The finite volume discretisation of the shallow water equations has been the subject of many previous studies, most of which deal with a well-balanced conservative discretisation of the convective flux and bathymetry. However, the bed friction discretisation ... Keywords: Bed friction, Depth averaged models, Finite volume method, High order schemes, Scalar transport, Shallow water equations, Unstructured mesh

L. Cea; M. E. Vázquez-Cendón

2012-04-01T23:59:59.000Z

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


21

A theoretical model for adsorption capacities of charcoal beds: I, Relative humidity effects  

SciTech Connect

Water vapor is the major interferent in the adsorption of other vapors from air when that air is passed through an activated charcoal bed. A limited amount of data (published and unpublished) is available on the magnitudes of capacity (or service life) reduction as a function of relative humidity (water vapor concentration) and preadsorbed water. A simple equilibrium model has been developed which quantitatively explains observed humidity effects and allows extrapolation of data to untested conditions. 9 refs., 4 figs., 2 tabs.

Wood, G.O.

1987-01-01T23:59:59.000Z

22

A mechanistic model for river incision into bedrock by saltating bed load  

E-Print Network (OSTI)

on the flux of impact kinetic energy normal to the bed and on the fraction of the bed that is not armored

Dietrich, William

23

Simple predictive model for performance of desiccant beds for solar dehumidification  

DOE Green Energy (OSTI)

A computer model is outlined for the absorption/desorption process that can be used to predict the performance of desiccant beds for solar regenerated dehumidification of passively cooled buildings. Instead of solving a set of coupled differential equations, the model uses simple algebraic equations for steady-state heat and mass exchangers. A comparison of computer predictions and experimental data demonstrate the validity and accuracy of the model. The physics of the adsorption process is discussed in terms of two psychrometric process lines, and planned research efforts at SERI are described.

Barlow, R.S.

1981-08-01T23:59:59.000Z

24

A One-Dimensional (1-D) Three-Region Model for a Bubbling Fluidized-Bed Adsorber  

SciTech Connect

A general one-dimensional (1-D), three-region model for a bubbling fluidized-bed adsorber with internal heat exchangers has been developed. The model can predict the hydrodynamics of the bed and provides axial profiles for all temperatures, concentrations, and velocities. The model is computationally fast and flexible and allows for any system of adsorption and desorption reactions to be modeled, making the model applicable to any adsorption process. The model has been implemented in both gPROMS and Aspen Custom Modeler, and the behavior of the model has been verified.

Lee, Andrew; Miller, David C.

2012-01-01T23:59:59.000Z

25

Statistical surrogate models for prediction of high-consequence climate change.  

SciTech Connect

In safety engineering, performance metrics are defined using probabilistic risk assessments focused on the low-probability, high-consequence tail of the distribution of possible events, as opposed to best estimates based on central tendencies. We frame the climate change problem and its associated risks in a similar manner. To properly explore the tails of the distribution requires extensive sampling, which is not possible with existing coupled atmospheric models due to the high computational cost of each simulation. We therefore propose the use of specialized statistical surrogate models (SSMs) for the purpose of exploring the probability law of various climate variables of interest. A SSM is different than a deterministic surrogate model in that it represents each climate variable of interest as a space/time random field. The SSM can be calibrated to available spatial and temporal data from existing climate databases, e.g., the Program for Climate Model Diagnosis and Intercomparison (PCMDI), or to a collection of outputs from a General Circulation Model (GCM), e.g., the Community Earth System Model (CESM) and its predecessors. Because of its reduced size and complexity, the realization of a large number of independent model outputs from a SSM becomes computationally straightforward, so that quantifying the risk associated with low-probability, high-consequence climate events becomes feasible. A Bayesian framework is developed to provide quantitative measures of confidence, via Bayesian credible intervals, in the use of the proposed approach to assess these risks.

Constantine, Paul; Field, Richard V., Jr.; Boslough, Mark Bruce Elrick

2011-09-01T23:59:59.000Z

26

Modeling of an adiabatic packed bed brine-air contactor for use in a solar energy driven food processing system  

Science Conference Proceedings (OSTI)

A mathematical model was developed for a packed bed brine-air contacting system which has applications in a solar energy driven food processing system. The model considers mass transfer resistances of both phases, but neglects the heat transfer resistance of the liquid phase. It takes into account the large heat effects associated with water absorption into and desorption from the brine. A computational method was also developed to calculate the minimum air flow rate which would prevent a pinch. A packed bed brine-air contactor was built, and experiments were conducted for a range of brine and air conditions. Good agreement between the computed and experimental results warrants use of the model to design and optimize the packed bed water stripping process. A periodic-flow packed bed heat regenerator was built to recover heat from the exit air of the contactor so as to improve the energy efficiency of the system. It was possible to preheat the inlet air to a temperature close to that of the exit air. The inlet air, however, during its passage through the regenerator picked up the condensate deposited from the exit air. This led to a decrease in the driving potential to mass transfer in the contactor. Optimization studies show that using a combined solar driven boiler and air assisted packed bed water stripper would be more economical than using a solar driven boiler alone or using flat plate solar collectors to drive the water stripper.

Biswal, R.N.

1983-01-01T23:59:59.000Z

27

Development of moving bed simulation model for carbon capture from fossil energy systems.  

Science Conference Proceedings (OSTI)

The capture and separation of carbon dioxide (CO2) has been identified as a high-priority topic to cope with global climate change. Fossil fuels currently supply the most of the world's energy needs, and their utilization is the major source of the anthropogenic CO2 emission [1]. Particularly, the existing coal-fired power plants annually emit about 2 billion tons of CO2 which is equivalent to two-thirds of the total emissions from U.S. power sector [2]. Therefore, it is critical to develop the cost-effective technologies to mitigate this problem. There are three options for capture for capturing CO2 from fossil energy system: post-combustion capture, pre-combustion capture, and oxy-combustion. Among them, post-combustion capture has the greatest near-term potential for reducing CO2 emission, because it can be applied to the existing coal-fired power plant with relative ease through a retrofit. The current commercially available solvent-based processes have advantages of fast kinetics and strong reactions, however only at a significant cost and efficiency penalty. Recently, various solid sorbents are being explored for one of promising CO2 capture technology, which are expected to reduce energy requirement and water usage with the approaches of fluidized or moving bed. However, solids are inherently more difficult to work with than liquids and no large scale system has yet been commercialized. In this study, we developed the rigorous 1-D PDE model for moving beds in Aspen Custom Modeler; the entire system consists of adsorbers, regenerators, and auxiliary equipment. The simulation result will be expected to compare with those of other post-combustion processes. We will deal with not only advantages of lower capital costs and power requirements but also problems associated with pressure drop and heat transfer.

Kim, H.; Miller, D.

2011-01-01T23:59:59.000Z

28

Modelling of mixing in bioreactors with mobile beds of immobilized biocatalysts for six radial impellers  

Science Conference Proceedings (OSTI)

The influences of the main factors on mixing efficiency and distribution for a bioreactor with stirred/mobile bed of immobilized S. cerevisiae cells in alginate (biocatalyst particles with 4, 4.6 and 5.2 mm diameters) have been comparatively analyzed ... Keywords: bioreactor, disperser sawtooth, immobilized cells, mixing time, pumper mixer, radial impeller, rushton turbine, smith turbine, stirred bed, yeasts

Marius Turnea; Anca Lup??teanu; Anca-Irina Galaction; Dan Ca?caval

2009-08-01T23:59:59.000Z

29

Mathematical modeling of heat and mass transfer in packed-bed adsorbers/regenerators  

SciTech Connect

Adsorber-regenerators are used extensively in the process industries for gas cleaning and separation. Nonisothermal adsorption is studied by incorporating its mathematical description into a model consisting of the full two-dimensional Navier-Stokes equations and energy and species concentration equations to simulate the processes in fixed-bed industrial adsorber/regenerators. The model partial-differential equations are solved numerically by using well-established computational fluid dynamics techniques. The equilibrium between gas and solid is considered nonlinear, which is described by Freundlich-type equations. The transport and adsorption of a compound from a solvent to and into an adsorbent are described by a two-step process: transport through the film to the outer surface of the particle and diffusion into the porous particle. The effect of fill resistance is discussed, as well as a two-equation turbulence model. Solutions obtained for a typical industrial adsorber/regenerator demonstrate the potential of this method. The computed results for various flow ratios and parameters in the Freundlich equations are shown to be physically plausible.

Gouvalias, G.S.; Markatos, N.C. (National Technical Univ., Athens (Greece). Dept. of Chemical Engineering)

1993-11-01T23:59:59.000Z

30

Numerical Modeling of Reactive Multiphase Flow for FCC and Hot Gas Desulfurization Circulating Fluidized Beds  

Science Conference Proceedings (OSTI)

This work was carried out to understand the behavior of the solid and gas phases in a CFB riser. Only the riser is modeled as a straight pipe. A model with linear algebraic approximation to solids viscosity of the form, {musubs} = 5.34{epsisubs}, ({espisubs} is the solids volume fraction) with an appropriate boundary condition at the wall obtained by approximate momentum balance solution at the wall to acount for the solids recirculation is tested against experimental results. The work done was to predict the flow patterns in the CFB risers from available experimental data, including data from a 7.5-cm-ID CFB riser at the Illinois Institute of Technology and data from a 20.0-cm-ID CFB riser at the Particulate Solid Research, Inc., facility. This research aims at modeling the removal of hydrogen sulfide from hot coal gas using zinc oxide as the sorbent in a circulating fluidized bed and in the process indentifying the parameters that affect the performance of the sulfidation reactor. Two different gas-solid reaction models, the unreacted shrinking core (USC) and the grain model were applied to take into account chemical reaction resistances. Also two different approaches were used to affect the hydrodynamics of the process streams. The first model takes into account the effect of micro-scale particle clustering by adjusting the gas-particle drag law and the second one assumes a turbulent core with pseudo-steady state boundary condition at the wall. A comparison is made with experimental results.

None

2005-07-01T23:59:59.000Z

31

Uncertainty and sensitivity analysis of early exposure results with the MACCS Reactor Accident Consequence Model  

Science Conference Proceedings (OSTI)

Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis and stepwise regression analysis are used in an investigation with the MACCS model of the early health effects associated with a severe accident at a nuclear power station. The primary purpose of this study is to provide guidance on the variables to be considered in future review work to reduce the uncertainty in the important variables used in the calculation of reactor accident consequences. The effects of 34 imprecisely known input variables on the following reactor accident consequences are studied: number of early fatalities, number of cases of prodromal vomiting, population dose within 10 mi of the reactor, population dose within 1000 mi of the reactor, individual early fatality probability within 1 mi of the reactor, and maximum early fatality distance. When the predicted variables are considered collectively, the following input variables were found to be the dominant contributors to uncertainty: scaling factor for horizontal dispersion, dry deposition velocity, inhalation protection factor for nonevacuees, groundshine shielding factor for nonevacuees, early fatality hazard function alpha value for bone marrow exposure, and scaling factor for vertical dispersion.

Helton, J.C. [Arizona State Univ., Tempe, AZ (United States); Johnson, J.D. [GRAM, Inc., Albuquerque, NM (United States); McKay, M.D. [Los Alamos National Lab., NM (United States); Shiver, A.W.; Sprung, J.L. [Sandia National Labs., Albuquerque, NM (United States)

1995-01-01T23:59:59.000Z

32

Surety of human elements of high consequence systems: An organic model  

Science Conference Proceedings (OSTI)

Despite extensive safety analysis and application of safety measures, there is a frequent lament, ``Why do we continue to have accidents?'' Two breakdowns are prevalent in risk management and prevention. First, accidents result from human actions that engineers, analysts and management never envisioned and second, controls, intended to preclude/mitigate accident sequences, prove inadequate. This paper addresses the first breakdown, the inability to anticipate scenarios involving human action/inaction. The failure of controls has been addressed in a previous publication (Forsythe and Grose, 1998). Specifically, this paper presents an approach referred to as surety. The objective of this approach is to provide high levels of assurance in situations where potential system failure paths cannot be fully characterized. With regard to human elements of complex systems, traditional approaches to human reliability are not sufficient to attain surety. Consequently, an Organic Model has been developed to account for the organic properties exhibited by engineered systems that result from human involvement in those systems.

FORSYTHE,JAMES C.; WENNER,CAREN A.

2000-04-25T23:59:59.000Z

33

Empirical models of emissions and energy efficiencies of coal-fired fluidized bed power plants  

E-Print Network (OSTI)

Mass and energy balances of fluidized bed energy technologies are to a significant degree dependent upon the specific design being investigated. It is difficult to make any generally accurate comments. about these balances. ...

Gruhl, Jim

34

Uncertainty and sensitivity analysis of food pathway results with the MACCS Reactor Accident Consequence Model  

Science Conference Proceedings (OSTI)

Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis and stepwise regression analysis are used in an investigation with the MACCS model of the food pathways associated with a severe accident at a nuclear power station. The primary purpose of this study is to provide guidance on the variables to be considered in future review work to reduce the uncertainty in the important variables used in the calculation of reactor accident consequences. The effects of 87 imprecisely-known input variables on the following reactor accident consequences are studied: crop growing season dose, crop long-term dose, milk growing season dose, total food pathways dose, total ingestion pathways dose, total long-term pathways dose, area dependent cost, crop disposal cost, milk disposal cost, condemnation area, crop disposal area and milk disposal area. When the predicted variables are considered collectively, the following input variables were found to be the dominant contributors to uncertainty: fraction of cesium deposition on grain fields that is retained on plant surfaces and transferred directly to grain, maximum allowable ground concentrations of Cs-137 and Sr-90 for production of crops, ground concentrations of Cs-134, Cs-137 and I-131 at which the disposal of milk will be initiated due to accidents that occur during the growing season, ground concentrations of Cs-134, I-131 and Sr-90 at which the disposal of crops will be initiated due to accidents that occur during the growing season, rate of depletion of Cs-137 and Sr-90 from the root zone, transfer of Sr-90 from soil to legumes, transfer of Cs-137 from soil to pasture, transfer of cesium from animal feed to meat, and the transfer of cesium, iodine and strontium from animal feed to milk.

Helton, J.C. [Arizona State Univ., Tempe, AZ (United States); Johnson, J.D.; Rollstin, J.A. [GRAM, Inc., Albuquerque, NM (United States); Shiver, A.W.; Sprung, J.L. [Sandia National Labs., Albuquerque, NM (United States)

1995-01-01T23:59:59.000Z

35

Uncertainty and sensitivity analysis of chronic exposure results with the MACCS reactor accident consequence model  

Science Conference Proceedings (OSTI)

Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis and stepwise regression analysis are used in an investigation with the MACCS model of the chronic exposure pathways associated with a severe accident at a nuclear power station. The primary purpose of this study is to provide guidance on the variables to be considered in future review work to reduce the uncertainty in the important variables used in the calculation of reactor accident consequences. The effects of 75 imprecisely known input variables on the following reactor accident consequences are studied: crop growing season dose, crop long-term dose, water ingestion dose, milk growing season dose, long-term groundshine dose, long-term inhalation dose, total food pathways dose, total ingestion pathways dose, total long-term pathways dose, total latent cancer fatalities, area-dependent cost, crop disposal cost, milk disposal cost, population-dependent cost, total economic cost, condemnation area, condemnation population, crop disposal area and milk disposal area. When the predicted variables are considered collectively, the following input variables were found to be the dominant contributors to uncertainty: dry deposition velocity, transfer of cesium from animal feed to milk, transfer of cesium from animal feed to meat, ground concentration of Cs-134 at which the disposal of milk products will be initiated, transfer of Sr-90 from soil to legumes, maximum allowable ground concentration of Sr-90 for production of crops, fraction of cesium entering surface water that is consumed in drinking water, groundshine shielding factor, scale factor defining resuspension, dose reduction associated with decontamination, and ground concentration of 1-131 at which disposal of crops will be initiated due to accidents that occur during the growing season.

Helton, J.C. [Arizona State Univ., Tempe, AZ (United States); Johnson, J.D.; Rollstin, J.A. [Gram, Inc., Albuquerque, NM (United States); Shiver, A.W.; Sprung, J.L. [Sandia National Labs., Albuquerque, NM (United States)

1995-01-01T23:59:59.000Z

36

Modeling the resolution of inexpensive, novel non-seismic geophysical monitoring tools to monitor CO2 injection into coal beds  

E-Print Network (OSTI)

of CO 2 enhanced coal bed methane (CBM) production. TheNIST Re Rx S Tx Coal Bed Methane Carbon dioxide ElectricCoal Beds as a part of the report on Stored CO 2 and Methane

Gasperikova, E.

2010-01-01T23:59:59.000Z

37

Source-Term and building-Wake Consequence Modeling for the Godiva IV Reactor at Los Alamos National Laboratory  

Science Conference Proceedings (OSTI)

The objectives of this work were to evaluate the consequences of a postulated accident to onsite security personnel stationed near the facility during operations of the Godiva IV critical assembly and to identify controls needed to protect these personnel in case of an extreme criticality excursion equivalent to the design-basis accident (DBA). This paper presents the methodology and results of the source-term calculations, building ventilation rates, air concentrations, and consequence calculations that were performed using a multidisciplinary approach with several phenomenology models. Identification of controls needed to mitigate the consequences to near-field receptors is discussed.

Letellier, B.C.; McClure, P.; Restrepo, L.

1999-06-13T23:59:59.000Z

38

Importance of emergency response actions to reactor accidents within a probabilistic consequence assessment model  

Science Conference Proceedings (OSTI)

An uncertainty and sensitivity analysis of early health consequences of severe accidents at nuclear power plants as a function of the emergency response parameters has been performed using a probabilistic consequence assessment code. The importance of various emergency response parameters in predicting the consequences for a range of accident source terms was determined through training a neural network algorithm which relates the sensitivity of the output to various choices of the input. Extensions of this approach should be helpful to planners in prioritizing the emergency responses at nuclear power plants.

Mubayi, V.; Neymotin, L.

1997-03-01T23:59:59.000Z

39

Modeling the resolution of inexpensive, novel non-seismic geophysical monitoring tools to monitor CO2 injection into coal beds  

E-Print Network (OSTI)

Plasynski, S. , 2008, Advancing Coal-Based Power Generationto monitor CO 2 injection into Coal Beds as a part of theanalysis for CO 2 movement in coal beds was based on the

Gasperikova, E.

2010-01-01T23:59:59.000Z

40

Second-generation pressurized fluidized bed combustion cold flow model tests of Phase 2 carbonizer  

SciTech Connect

Under US Department of Energy Contract DE-AC21-86MC21023, Foster Wheeler Development Corporation (FWDC) is developing a second-generation pressurized fulidized bed (PFB) combustion system. The second-generation system is an improvement over first-generation pressurized systems because higher gas turbine inlet temperatures, and thus greater system efficiencies can be achieved. In first-generation systems, the gas turbine operates at temperatures lower than those in the PFB combusting bed, with the latter being limited to approximately 1600{degree}F to control alkali release/gas turbine hot corrosion. The second-generation system overcomes this temperature restriction by including a carbonizer and a topping combustor in the system. The carbonizer is a PFB combustion unit that converts coal to a low-Btu fuel gas and char. The char is transferred to a PFB combustor (PFBC), where it is burned. The flue gas from the PFBC and the fuel gas from the carbonizer go to the topping combustor, where the fuel gas is burned and gas turbine inlet temperatures in excess of 2100{degree}F are generated. The PFBC can be operated with or without coal fed along with the char. Steam is generated in the PFBC, and additional coal fed to the PFBC with the char will result in more steam generation. However, excess air must be kept at a level sufficient to support combustion of the fuel gas in the topping combustor.

Shenker, J.

1991-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "bed consequence modeling" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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41

Use of BDST and an ANN model for prediction of dye adsorption efficiency of Eucalyptus camaldulensis barks in fixed-bed system  

Science Conference Proceedings (OSTI)

In this study, the Bohart and Adams' model taking into account bed depth, and influent dye concentration was studied to exhibit adsorption process of textile dyes (Basic Blue 41 - BB41 and Reactive Black 5 - RB5) in glass columns using tree barks (Eucalyptus ... Keywords: ANN, Adsorption columns, BB41, BDST, BDST model, neural networks, Dyes, Eucalyptus camaldulensis, MLP, RB5, Tree barks

Behzat Balci; Olcayto Keskinkan; Mutlu Avci

2011-01-01T23:59:59.000Z

42

Biomass Torrefaction Process Review and Moving Bed Torrefaction System Model Development  

Science Conference Proceedings (OSTI)

Torrefaction is currently developing as an important preprocessing step to improve the quality of biomass in terms of physical properties, and proximate and ultimate composition. Torrefaction is a slow heating of biomass in an inert or reduced environment to a maximum temperature of 300 C. Torrefaction can also be defined as a group of products resulting from the partially controlled and isothermal pyrolysis of biomass occurring in a temperature range of 200-230 C and 270-280 C. Thus, the process can also be called a mild pyrolysis as it occurs at the lower temperature range of the pyrolysis process. At the end of the torrefaction process, a solid uniform product with lower moisture content and higher energy content than raw biomass is produced. Most of the smoke-producing compounds and other volatiles are removed during torrefaction, producing a final product that will have a lower mass but a higher heating value. An important aspect of research is to establish a degree of torrefaction where gains in heating value offset the loss of mass. There is a lack of literature on torrefaction reactor designs and a design sheet for estimating the dimensions of the torrefier based on capacity. This study includes (a) conducting a detailed review on the torrefaction of biomass in terms of understanding the process, product properties, off-gas compositions, and methods used, and (b) to design a moving bed torrefier, taking into account the basic fundamental heat and mass transfer calculations. Specific objectives include calculating the dimensions like diameter and height of the moving packed bed for different capacities, designing the heat loads and gas flow rates, and developing an interactive excel sheet where the user can define design specifications. In this report, 25-1000 kg/hr are used in equations for the design of the torrefier, examples of calculations, and specifications for the torrefier.

Jaya Shakar Tumuluru; Shahab Sokhansanj; Christopher T. Wright; Richard D. Boardman

2010-08-01T23:59:59.000Z

43

Biomass Torrefaction Process Review and Moving Bed Torrefaction System Model Development  

DOE Green Energy (OSTI)

Torrefaction is currently developing as an important preprocessing step to improve the quality of biomass in terms of physical properties, and proximate and ultimate composition. Torrefaction is a slow heating of biomass in an inert or reduced environment to a maximum temperature of 300°C. Torrefaction can also be defined as a group of products resulting from the partially controlled and isothermal pyrolysis of biomass occurring in a temperature range of 200–230ºC and 270–280ºC. Thus, the process can also be called a mild pyrolysis as it occurs at the lower temperature range of the pyrolysis process. At the end of the torrefaction process, a solid uniform product with lower moisture content and higher energy content than raw biomass is produced. Most of the smoke-producing compounds and other volatiles are removed during torrefaction, producing a final product that will have a lower mass but a higher heating value. An important aspect of research is to establish a degree of torrefaction where gains in heating value offset the loss of mass. There is a lack of literature on torrefaction reactor designs and a design sheet for estimating the dimensions of the torrefier based on capacity. This study includes a) conducting a detailed review on the torrefaction of biomass in terms of understanding the process, product properties, off-gas compositions, and methods used, and b) to design a moving bed torrefier, taking into account the basic fundamental heat and mass transfer calculations. Specific objectives include calculating the dimensions like diameter and height of the moving packed bed for different capacities, designing the heat loads and gas flow rates, and developing an interactive excel sheet where the user can define design specifications. In this report, 25–1000 kg/hr are used in equations for the design of the torrefier, examples of calculations, and specifications for the torrefier.

Jaya Shakar Tumuluru; Shahab Sokhansanj; Christopher T. Wright

2010-08-01T23:59:59.000Z

44

Nuclear winter revisited with a modern climate model and current nuclear arsenals: Still catastrophic consequences  

E-Print Network (OSTI)

Nuclear winter revisited with a modern climate model and current nuclear arsenals: Still of climate model simulations of the response to smoke and dust from a massive nuclear exchange between the superpowers could be summarized as ``nuclear winter,'' with rapid temperature, precipitation, and insolation

Robock, Alan

45

Health effects models for nuclear power plant accident consequence analysis: Low LET radiation  

SciTech Connect

This report describes dose-response models intended to be used in estimating the radiological health effects of nuclear power plant accidents. Models of early and continuing effects, cancers and thyroid nodules, and genetic effects are provided. Weibull dose-response functions are recommended for evaluating the risks of early and continuing health effects. Three potentially lethal early effects -- the hematopoietic, pulmonary, and gastrointestinal syndromes -- are considered. In addition, models are included for assessing the risks of several nonlethal early and continuing effects -- including prodromal vomiting and diarrhea, hypothyroidism and radiation thyroiditis, skin burns, reproductive effects, and pregnancy losses. Linear and linear-quadratic models are recommended for estimating cancer risks. Parameters are given for analyzing the risks of seven types of cancer in adults -- leukemia, bone, lung, breast, gastrointestinal, thyroid, and other.'' The category, other'' cancers, is intended to reflect the combined risks of multiple myeloma, lymphoma, and cancers of the bladder, kidney, brain, ovary, uterus and cervix. Models of childhood cancers due to in utero exposure are also developed. For most cancers, both incidence and mortality are addressed. The models of cancer risk are derived largely from information summarized in BEIR III -- with some adjustment to reflect more recent studies. 64 refs., 18 figs., 46 tabs.

Evans, J.S. (Harvard Univ., Boston, MA (USA). School of Public Health)

1990-01-01T23:59:59.000Z

46

Investigation of hydrodynamics of a dual fluidized bed biomass steam gasifier using a cold model: The effect of fluidising agent on gasification performance  

E-Print Network (OSTI)

Investigation of hydrodynamics of a dual fluidized bed biomass steam gasifier using a cold model) biomass steam gasifiers are able to produce gas with low tar and high hydrogen contents and have shown a promising potential for converting the biomass to hydrogen-rich syngas. The DFB gasifier system

Hickman, Mark

47

Modeling scaleup effects on a small pilot-scale fluidized-bed reactor for fuel ethanol production  

DOE Green Energy (OSTI)

Domestic ethanol use and production are presently undergoing significant increases along with planning and construction of new production facilities. Significant efforts are ongoing to reduce ethanol production costs by investigating new inexpensive feedstocks (woody biomass) and by reducing capital and energy costs through process improvements. A key element in the development of advanced bioreactor systems capable of very high conversion rates is the retention of high biocatalyst concentrations within the bioreactor and a reaction environment that ensures intimate contact between substrate and biocatalyst. One very effective method is to use an immobilized biocatalyst that can be placed into a reaction environment that provides effective mass transport, such as a fluidized bed. Mathematical descriptions are needed based on fundamental principles and accepted correlations that describe important physical phenomena. We describe refinements and semi-quantitatively extend the predictive model of Petersen and Davison to a multiphase fluidized-bed reactor (FBR) that was scaled-up for ethanol production. Axial concentration profiles were evaluated by solving coupled differential equations for glucose and carbon dioxide. The pilot-scale FBR (2 to 5 m tall, 10.2-cm ID, and 23,000 L month{sup -1} capacity) was scaled up from bench-scale reactors (91 to 224 cm long, 2.54 to 3.81 cm ID, and 400 to 2,300 L month{sup -1} capacity). Significant improvements in volumetric productivites (50 to 200 g EtOH h{sup -1} L{sup -1} compared with 40 to 110 for bench-scale experiments and 2 to 10 for reported industrial benchmarks) and good operability were demonstrated.

Webb, O.F.; Davison, B.H.; Scott, T.C.

1995-09-01T23:59:59.000Z

48

Development of hydrogeological modelling approaches for assessment of consequences of hazardous accidents at nuclear power plants  

SciTech Connect

This paper introduces some modeling approaches for predicting the influence of hazardous accidents at nuclear reactors on groundwater quality. Possible pathways for radioactive releases from nuclear power plants were considered to conceptualize boundary conditions for solving the subsurface radionuclides transport problems. Some approaches to incorporate physical-and-chemical interactions into transport simulators have been developed. The hydrogeological forecasts were based on numerical and semi-analytical scale-dependent models. They have been applied to assess the possible impact of the nuclear power plants designed in Russia on groundwater reservoirs.

Rumynin, V.G.; Mironenko, V.A.; Konosavsky, P.K.; Pereverzeva, S.A. [St. Petersburg Mining Inst. (Russian Federation)

1994-07-01T23:59:59.000Z

49

Compilation of gas intrusion measurements, variations, and consequence modeling for SPR caverns.  

Science Conference Proceedings (OSTI)

The intrusion of gas into oils stored within the SPR has been examined. When oil is stored in domal salts, gases intrude into the stored oil from the surrounding salt. Aspects of the mechanism of gas intrusion have been examined. In all cases, this gas intrusion results in increases in the oil vapor pressure. Data that have been gathered from 1993 to August 2002 are presented to show the resultant increases in bubble-point pressure on a cavern-by-cavern as well as on a stream basis. The measurement techniques are presented with particular emphasis on the TVP 95. Data analysis methods are presented to show the methods required to obtain recombined cavern oil compositions. Gas-oil ratios are also computed from the data and are presented on a cavern-by-cavern and stream basis. The observed increases in bubble-point pressure and gas-oil ratio are further statistically analyzed to allow data interpretation. Emissions plume modeling is used to determine adherence to state air regulations. Gas intrusion is observed to be variable among the sites and within each dome. Gas intrusions at Bryan Mound and Big Hill have resulted in the largest increases in bubble-point pressure for the Strategic Petroleum Reserve (SPR). The streams at Bayou Choctaw and West Hackberry show minimal bubble-point pressure increases. Emissions plume modeling, using the state mandated ISCST code, of oil storage tanks showed that virtually no gas may be released when H2S standards are considered. DOE plans to scavenge H2S to comply with the very tight standards on this gas. With the assumption of scavenging, benzene releases become the next most controlling factor. Model results show that a GOR of 0.6 SCF/BBL may be emissions that are within standards. Employing the benzene gas release standard will significantly improve oil deliverability. New plume modeling using the computational fluid dynamics code, FLUENT, is addressing limitations of the state mandated ISCST model.

Hinkebein, Thomas E.

2003-03-01T23:59:59.000Z

50

Extended macroscopic dispersion model with applications to confined packed beds and capillary column inverse gas chromatography.  

E-Print Network (OSTI)

??Until present, many researchers relied on the conventional plug flow dispersion models to analyse the concentration profiles obtained from the tracer injection experiments to evaluate… (more)

Hamdan, Emad

2008-01-01T23:59:59.000Z

51

Linear driving force models for dynamic adsorption of volatile organic compound traces by porous adsorbent beds  

Science Conference Proceedings (OSTI)

Models for the dynamic adsorption of volatile organic compound (VOC) traces in air are considered. They are based on the linear driving force approximation associated with various adsorption isotherms characteristic of the couple VOC-adsorbent (Langmuir, ... Keywords: Comsol, Dubinin-Astakhov isotherm, Dynamic adsorption modelling, Finite element

Agnès Joly; Alain Perrard

2009-08-01T23:59:59.000Z

52

Health effects model for nuclear power plant accident consequence analysis. Part I. Introduction, integration, and summary. Part II. Scientific basis for health effects models  

Science Conference Proceedings (OSTI)

Analysis of the radiological health effects of nuclear power plant accidents requires models for predicting early health effects, cancers and benign thyroid nodules, and genetic effects. Since the publication of the Reactor Safety Study, additional information on radiological health effects has become available. This report summarizes the efforts of a program designed to provide revised health effects models for nuclear power plant accident consequence modeling. The new models for early effects address four causes of mortality and nine categories of morbidity. The models for early effects are based upon two parameter Weibull functions. They permit evaluation of the influence of dose protraction and address the issue of variation in radiosensitivity among the population. The piecewise-linear dose-response models used in the Reactor Safety Study to predict cancers and thyroid nodules have been replaced by linear and linear-quadratic models. The new models reflect the most recently reported results of the follow-up of the survivors of the bombings of Hiroshima and Nagasaki and permit analysis of both morbidity and mortality. The new models for genetic effects allow prediction of genetic risks in each of the first five generations after an accident and include information on the relative severity of various classes of genetic effects. The uncertainty in modeloling radiological health risks is addressed by providing central, upper, and lower estimates of risks. An approach is outlined for summarizing the health consequences of nuclear power plant accidents. 298 refs., 9 figs., 49 tabs.

Evans, J.S.; Moeller, D.W.; Cooper, D.W.

1985-07-01T23:59:59.000Z

53

Health effects models for nuclear power plant accident consequence analysis. Part 1, Introduction, integration, and summary: Revision 2  

SciTech Connect

This report is a revision of NUREG/CR-4214, Rev. 1, Part 1 (1990), Health Effects Models for Nuclear Power Plant Accident Consequence Analysis. This revision has been made to incorporate changes to the Health Effects Models recommended in two addenda to the NUREG/CR-4214, Rev. 1, Part 11, 1989 report. The first of these addenda provided recommended changes to the health effects models for low-LET radiations based on recent reports from UNSCEAR, ICRP and NAS/NRC (BEIR V). The second addendum presented changes needed to incorporate alpha-emitting radionuclides into the accident exposure source term. As in the earlier version of this report, models are provided for early and continuing effects, cancers and thyroid nodules, and genetic effects. Weibull dose-response functions are recommended for evaluating the risks of early and continuing health effects. Three potentially lethal early effects -- the hematopoietic, pulmonary, and gastrointestinal syndromes are considered. Linear and linear-quadratic models are recommended for estimating the risks of seven types of cancer in adults - leukemia, bone, lung, breast, gastrointestinal, thyroid, and ``other``. For most cancers, both incidence and mortality are addressed. Five classes of genetic diseases -- dominant, x-linked, aneuploidy, unbalanced translocations, and multifactorial diseases are also considered. Data are provided that should enable analysts to consider the timing and severity of each type of health risk.

Evans, J.S. [Harvard School of Public Health, Boston, MA (United States); Abrahmson, S. [Wisconsin Univ., Madison, WI (United States); Bender, M.A. [Brookhaven National Lab., Upton, NY (United States); Boecker, B.B.; Scott, B.R. [Inhalation Toxicology Research Inst., Albuquerque, NM (United States); Gilbert, E.S. [Battelle Pacific Northwest Lab., Richland, WA (United States)

1993-10-01T23:59:59.000Z

54

MCNP4B MODELING OF PEBBLE-BED REACTORS Julian Robert Lebenhaft  

E-Print Network (OSTI)

led to new challenges in tribological modeling [15, 25, 27]. Industry pushes towards the assessment. Effect of surface texturing on friction reduction between ceramic and steel materials under lubricated

55

Cosmological Consequences of String Axions  

E-Print Network (OSTI)

2005 Cosmological Consequences of String Axions ? Ben Kain †for the model independent string axion we consider thefor two additional string axions. We do so independent of

Kain, Ben

2005-01-01T23:59:59.000Z

56

CERTS Microgrid Laboratory Test Bed  

E-Print Network (OSTI)

Diagram of CERTS Microgrid Test Bed Figure 3. Tecogen PrimeCERTS Microgrid Laboratory Test Bed. (California EnergyFigure 1. CERTS Microgrid Test Bed at American Electric

ETO, J.

2010-01-01T23:59:59.000Z

57

A generalized theory for non-classical transport with angular-dependent path-length distributions 2: Anisotropic diffusion in model pebble bed reactor cores  

E-Print Network (OSTI)

We describe an analysis of neutron transport in the interior of model pebble bed reactor (PBR) cores, considering both crystal and random pebble arrangements. Monte Carlo codes were developed for (i) generating random realizations of the model PBR core, and (ii) performing neutron transport inside the crystal and random heterogeneous cores; numerical results are presented for two different choices of material parameters. These numerical results are used to investigate the anisotropic behavior of neutrons in each case and to assess the accuracy of estimates for the diffusion coefficients obtained with the diffusion approximations of different models: the atomic mix model, the Behrens correction, the Lieberoth correction, the generalized linear Boltzmann equation (GLBE), and the new GLBE with angular-dependent path-length distributions. This new theory utilizes a non-classical form of the Boltzmann equation in which the locations of the scattering centers in the system are correlated and the distance-to-collisi...

Vasques, Richard

2013-01-01T23:59:59.000Z

58

Review on Biomass Torrefaction Process and Product Properties and Design of Moving Bed Torrefaction System Model Development  

Science Conference Proceedings (OSTI)

A Review on Torrefaction Process and Design of Moving Bed Torrefaction System for Biomass Processing Jaya Shankar Tumuluru1, Shahab Sokhansanj2 and Christopher T. Wright1 Idaho National Laboratory Biofuels and Renewable Energy Technologies Department Idaho Falls, Idaho 83415 Oak Ridge National Laboratory Bioenergy Resource and Engineering Systems Group Oak Ridge, TN 37831 Abstract Torrefaction is currently developing as an important preprocessing step to improve the quality of biomass in terms of physical properties, and proximate and ultimate composition. Torrefaction is a slow heating of biomass in an inert or reduced environment to a maximum temperature of 300 C. Torrefaction can also be defined as a group of products resulting from the partially controlled and isothermal pyrolysis of biomass occurring in a temperature range of 200-230 C and 270-280 C. Thus, the process can also be called a mild pyrolysis as it occurs at the lower temperature range of the pyrolysis process. At the end of the torrefaction process, a solid uniform product with lower moisture content and higher energy content than raw biomass is produced. Most of the smoke-producing compounds and other volatiles are removed during torrefaction, which produces a final product that will have a lower mass but a higher heating value. There is a lack of literature on the design aspects of torrefaction reactor and a design sheet for estimating the dimensions of the torrefier based on capacity. This study includes (a) conducting a detailed review on the torrefaction of biomass in terms of understanding the process, product properties, off-gas compositions, and methods used, and (b) to design a moving bed torrefier, taking into account the basic fundamental heat and mass transfer calculations. Specific objectives include calculating the dimensions like diameter and height of the moving packed bed torrefier for different capacities ranging from 25-1000 kg/hr, designing the heat loads and gas flow rates, and developing an interactive excel sheet where the user can define design specifications.

Jaya Shankar Tumuluru; Christopher T. Wright; Shahab Sokhansanj

2011-08-01T23:59:59.000Z

59

Particle pressures in fluidized beds. Final report  

SciTech Connect

This project studies the particle pressure, which may be thought of as the force exerted by the particulate phase of a multiphase mixture, independently of that exerted by other phases. The project is divided into two parts, one concerning gas and the other liquid fluidized beds. Previous work on gas fluidized beds had suggested that the particle pressures are generated by bubbling action. Thus, for these gas fluidized bed studies, the particle pressure is measured around single bubbles generated in 2-D fluidized beds, using special probes developed especially for this purpose. Liquid beds are immune from bubbling and the particle pressures proved too small to measure directly. However, the major interest in particle pressures in liquid beds lies in their stabilizing effect that arises from the effective elasticity (the derivative of the particle pressure with respect to the void fraction), they impart to the bed. So rather than directly measure the particle pressure, the authors inferred the values of the elasticity from measurements of instability growth in liquid beds; the inference was made by first developing a generic stability model (one with all the normally modeled coefficients left undetermined) and then working backwards to determine the unknown coefficients, including the elasticity.

Campbell, C.S.; Rahman, K.; Jin, C.

1996-09-01T23:59:59.000Z

60

Particle Pressures in Fluidized Beds. Final report  

SciTech Connect

This project studies the particle pressure, which may be thought of as the force exerted by the particulate phase of a multiphase mixture, independently of that exerted by other phases. The project is divided into two parts, one concerning gas and the other liquid fluidized beds. Previous work on gas fluidized beds had suggested that the particle pressures are generated by bubbling action. Thus, for these gas fluidized bed studies, the particle pressure is measured around single bubbles generated in 2-D fluidized beds, using special probes developed especially for this purpose. Liquid beds are immune from bubbling and the particle pressures proved too small to measure directly. However, the major interest in particle pressures in liquid beds lies in their stabilizing effect that arises from the effective elasticity (the derivative of the particle pressure with respect to the void fraction): they impart to the bed. So rather than directly measure the particle pressure, we inferred the values of the elasticity from measurements of instability growth in liquid beds the inference was made by first developing a generic stability model (one with all the normally modeled coefficients left undetermined)and then working backwards to determine the unknown coefficients, including the elasticity.

Campbell, C.S.; Rahman, K.; Jin, C.

1996-09-01T23:59:59.000Z

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


61

Health effects models for nuclear power plant accident consequence analysis. Modification of models resulting from addition of effects of exposure to alpha-emitting radionuclides: Revision 1, Part 2, Scientific bases for health effects models, Addendum 2  

SciTech Connect

The Nuclear Regulatory Commission (NRC) has sponsored several studies to identify and quantify, through the use of models, the potential health effects of accidental releases of radionuclides from nuclear power plants. The Reactor Safety Study provided the basis for most of the earlier estimates related to these health effects. Subsequent efforts by NRC-supported groups resulted in improved health effects models that were published in the report entitled {open_quotes}Health Effects Models for Nuclear Power Plant Consequence Analysis{close_quotes}, NUREG/CR-4214, 1985 and revised further in the 1989 report NUREG/CR-4214, Rev. 1, Part 2. The health effects models presented in the 1989 NUREG/CR-4214 report were developed for exposure to low-linear energy transfer (LET) (beta and gamma) radiation based on the best scientific information available at that time. Since the 1989 report was published, two addenda to that report have been prepared to (1) incorporate other scientific information related to low-LET health effects models and (2) extend the models to consider the possible health consequences of the addition of alpha-emitting radionuclides to the exposure source term. The first addendum report, entitled {open_quotes}Health Effects Models for Nuclear Power Plant Accident Consequence Analysis, Modifications of Models Resulting from Recent Reports on Health Effects of Ionizing Radiation, Low LET Radiation, Part 2: Scientific Bases for Health Effects Models,{close_quotes} was published in 1991 as NUREG/CR-4214, Rev. 1, Part 2, Addendum 1. This second addendum addresses the possibility that some fraction of the accident source term from an operating nuclear power plant comprises alpha-emitting radionuclides. Consideration of chronic high-LET exposure from alpha radiation as well as acute and chronic exposure to low-LET beta and gamma radiations is a reasonable extension of the health effects model.

Abrahamson, S. [Wisconsin Univ., Madison, WI (United States); Bender, M.A. [Brookhaven National Lab., Upton, NY (United States); Boecker, B.B.; Scott, B.R. [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States). Inhalation Toxicology Research Inst.; Gilbert, E.S. [Pacific Northwest Lab., Richland, WA (United States)

1993-05-01T23:59:59.000Z

62

Wind Waves and Moveable-Bed Bottom Friction  

Science Conference Proceedings (OSTI)

Effects of moveable-bed bottom friction for wave observations and wave modeling are investigated using a state-of-the-art bottom friction model. This model combines the hydrodynamic friction model of Madsen et al. with a moveable-bed roughness ...

Hendrik L. Tolman

1994-05-01T23:59:59.000Z

63

Fluidized bed calciner apparatus  

DOE Patents (OSTI)

An apparatus for remotely calcining a slurry or solution feed stream of toxic or hazardous material, such as ammonium diurante slurry or uranyl nitrate solution, is disclosed. The calcining apparatus includes a vertical substantially cylindrical inner shell disposed in a vertical substantially cylindrical outer shell, in which inner shell is disposed a fluidized bed comprising the feed stream material to be calcined and spherical beads to aid in heat transfer. Extending through the outer and inner shells is a feed nozzle for delivering feed material or a cleaning chemical to the beads. Disposed in and extending across the lower portion of the inner shell and upstream of the fluidized bed is a support member for supporting the fluidized bed, the support member having uniform slots for directing uniform gas flow to the fluidized bed from a fluidizing gas orifice disposed upstream of the support member. Disposed in the lower portion of the inner shell are a plurality of internal electric resistance heaters for heating the fluidized bed. Disposed circumferentially about the outside length of the inner shell are a plurality of external heaters for heating the inner shell thereby heating the fluidized bed. Further, connected to the internal and external heaters is a means for maintaining the fluidized bed temperature to within plus or minus approximately 25.degree. C. of a predetermined bed temperature. Disposed about the external heaters is the outer shell for providing radiative heat reflection back to the inner shell.

Owen, Thomas J. (West Richland, WA); Klem, Jr., Michael J. (Richland, WA); Cash, Robert J. (Richland, WA)

1988-01-01T23:59:59.000Z

64

Bed Surface Patchiness in Gravel-Bed Rivers  

E-Print Network (OSTI)

this case was a completely armored, immobile bed. Table 2.4that gravel beds are armored because equal mobil- ity

Nelson, Peter August

2010-01-01T23:59:59.000Z

65

Bed inventory overturn in a circulating fluid bed riser with pant-leg structure  

Science Conference Proceedings (OSTI)

The special phenomenon, nominated as bed inventory overturn, in circulating fluid bed (CFB) riser with pant-leg structure was studied with model calculation and experimental work. A compounded pressure drop mathematic model was developed and validated with the experimental data in a cold experimental test rig. The model calculation results agree well with the measured data. In addition, the intensity of bed inventory overturn is directly proportional to the fluidizing velocity and is inversely proportional to the branch point height. The results in the present study provide significant information for the design and operation of a CFB boiler with pant-leg structure. 15 refs., 10 figs., 1 tab.

Jinjing Li; Wei Wang; Hairui Yang; Junfu Lv; Guangxi Yue [Tsinghua University, Beijing (China). Key Laboratory for Thermal Science and Power Engineering of Ministry of Education

2009-05-15T23:59:59.000Z

66

CERTS Microgrid Laboratory Test Bed  

E-Print Network (OSTI)

Diagram of CERTS Microgrid Test Bed Figure 3. Tecogen Prime2009 CERTS Microgrid Laboratory Test Bed J. ETO, Lawrenceof the CERTS Microgrid Test Bed project was to enhance the

Eto, Joe

2009-01-01T23:59:59.000Z

67

CERTS Microgrid Laboratory Test Bed  

E-Print Network (OSTI)

Line Diagram of CERTS Microgrid Test Bed Figure 3. TecogenCALGARY 2009 CERTS Microgrid Laboratory Test Bed J. ETO,The objective of the CERTS Microgrid Test Bed project was to

Eto, Joe

2009-01-01T23:59:59.000Z

68

Consequences of Using the Splitting Method for Implementing Physical Forcings in a Semi-Implicit Semi-Lagrangian Model  

Science Conference Proceedings (OSTI)

Any comprehensive numerical model is composed of two parts: a dynamical kernel solving for the fluid mechanical field equations and a physical package to parameterize the ensemble effect of subgrid-scale processes upon the resolved scales of the ...

Alain Caya; René Laprise; Peter Zwack

1998-06-01T23:59:59.000Z

69

CERTS Microgrid Laboratory Test Bed  

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

CERTS Microgrid Laboratory Test Bed Title CERTS Microgrid Laboratory Test Bed Publication Type Report Year of Publication 2010 Authors Lasseter, Robert H., Joseph H. Eto, Ben...

70

Plate Tectonic Consequences of competing models for the origin and history of the Banda Sea subducted oceanic lithosphere  

E-Print Network (OSTI)

The Banda Arc, situated west of Irian Jaya and in the easternmost extension of the Sunda subduction zone system, reveals a characteristic bowl-shaped geometry in seismic tomographic images. This indicates that the oceanic lithosphere still remains attached to the surrounding continental margins of northern Australia and the Bird's Head microcontinent. Major controversies exist between authors proposing an allochthonous or autochthonous origin of the Bird's Head block. Either scenario has important implications for plate kinematic models aiming to reconstruct the tectonic evolution of the region and the late Jurassic seaoor spreading geometry of this now subducted Argo-Tanimbar-Seram (ATS) ocean basin. Wider implications affect the tectonic conguration of the Tethyan-Pacic realm, the distribution of plate boundaries as well as the shape and size of continental blocks which have been rifted off the northeastern Gondwana margin during the Late Jurassic and are now accreted to the SE Asia margin. We apply structu...

Heine, Christian; McKay, Hamish; Müller, R Dietmar

2012-01-01T23:59:59.000Z

71

Electron Beam Powder Bed Processes  

Science Conference Proceedings (OSTI)

Advanced Materials, Processes and Applications for Additive Manufacturing : Electron Beam Powder Bed Processes Program Organizers: Andrzej ...

72

Reduction of iron ore fines by coal fines in a packed bed and fluidized bed apparatus: A comparative study  

SciTech Connect

Reduction of iron ore fines by coal fines in packed and fluidized beds has been studied. The investigation includes study of the kinetic aspects of reduction, carbon and sulfur content of the direct reduced iron (DRI) produced, and metallography of the products. For both processes, the kinetic data fit the first-order reaction model. Reduction in a fluidized bed is much faster than in a packed bed system. In both cases, DRI contains a substantial amount of free carbon at the kinetic data fit the first-order reaction model. Reduction in a fluidized bed is much faster than in a packed bed system. In both cases, DRI contains a substantial amount of free carbon at the initial stages of reduction. At the later stages of reduction, the carbon present in the DRI is mainly in the combined state. For identical temperatures and particle sizes, reaction in fluidized bed is much faster compared to that in a packed bed. At any particular degree of reduction, sulfur content in DRI samples produced by fluidized bed reduction is always more than that of DRI samples produced by packed bed reduction. Scanning electron microscopy (SEM) micrographs reveal that metallic whiskers formed during reduction in packed beds only. These whiskers become more prominent at higher temperatures and longer times.

Haque, R. (Bangladesh Univ. of Engineering and Technology, Dhaka (Bangladesh). Metallurgical Engineering Department); Ray, H.S. (Regional Research Lab., Orissa (India)); Mukherjee, A. (Indian Inst. of Tech., (India).Metallurgical Engineering Department)

1993-06-01T23:59:59.000Z

73

Fluid bed material transfer method  

DOE Patents (OSTI)

A fluidized bed apparatus comprising a pair of separated fluid bed enclosures, each enclosing a fluid bed carried on an air distributor plate supplied with fluidizing air from below the plate. At least one equalizing duct extending through sidewalls of both fluid bed enclosures and flexibly engaged therewith to communicate the fluid beds with each other. The equalizing duct being surrounded by insulation which is in turn encased by an outer duct having expansion means and being fixed between the sidewalls of the fluid bed enclosures.

Pinske, Jr., Edward E. (Akron, OH)

1994-01-01T23:59:59.000Z

74

Apparatus for controlling fluidized beds  

DOE Patents (OSTI)

An apparatus and process are disclosed for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance. 2 figs.

Rehmat, A.G.; Patel, J.G.

1987-05-12T23:59:59.000Z

75

Apparatus for controlling fluidized beds  

DOE Patents (OSTI)

An apparatus and process for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance.

Rehmat, Amirali G. (Westmont, IL); Patel, Jitendra G. (Bolingbrook, IL)

1987-05-12T23:59:59.000Z

76

Transportation Safeguards & Security Test Bed (TSSTB) | ORNL  

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

Transportation Safeguards and Security Test Bed May 30, 2013 The Transportation Safeguards and Security Test Bed consists of a test-bed vehicle and a monitoringlaboratorytraining...

77

Staged fluidized bed  

DOE Patents (OSTI)

The invention relates to oil shale retorting and more particularly to staged fluidized bed oil shale retorting. Method and apparatus are disclosed for narrowing the distribution of residence times of any size particle and equalizing the residence times of large and small particles in fluidized beds. Particles are moved up one fluidized column and down a second fluidized column with the relative heights selected to equalize residence times of large and small particles. Additional pairs of columns are staged to narrow the distribution of residence times and provide complete processing of the material.

Mallon, R.G.

1983-05-13T23:59:59.000Z

78

Cassini Spacecraft Uncertainty Analysis Data and Methodology Review and Update/Volume 1: Updated Parameter Uncertainty Models for the Consequence Analysis  

DOE Green Energy (OSTI)

Uncertainty distributions for specific parameters of the Cassini General Purpose Heat Source Radioisotope Thermoelectric Generator (GPHS-RTG) Final Safety Analysis Report consequence risk analysis were revised and updated. The revisions and updates were done for all consequence parameters for which relevant information exists from the joint project on Probabilistic Accident Consequence Uncertainty Analysis by the United States Nuclear Regulatory Commission and the Commission of European Communities.

WHEELER, TIMOTHY A.; WYSS, GREGORY D.; HARPER, FREDERICK T.

2000-11-01T23:59:59.000Z

79

CERTS Microgrid Laboratory Test Bed  

E-Print Network (OSTI)

Line Diagram of CERTS Microgrid Test Bed Figure 3. TecogenRoy, N. Lewis. 2008. CERTS Microgrid Laboratory Test Bed. (Energy Resources: The MicroGrid Concept. (Lawrence Berkeley

ETO, J.

2010-01-01T23:59:59.000Z

80

Bed expansion crucible tests  

SciTech Connect

The Am/Cm program will vitrify the americium and curium currently stored in F-canyon. A batch flowsheet has been developed (with non-radioactive surrogate feed in place of the F-canyon solution) and tested full-scale in the 5-inch Cylindrical Induction Melter (CIM) facility at TNX. During a normal process run, a small bed expansion occurs when oxygen released from reduction of cerium (IV) oxide to cerium (III) oxide is trapped in highly viscous glass. The bed expansion is characterized by a foamy layer of glass that slowly expands as the oxygen is trapped and then dissipates when the viscosity of the foam becomes low enough to allow the oxygen to escape. Severe bed expansions were noted in the 5-inch CIM when re-heating after an interlock during the calcination phase of the heat cycle, escaping the confines of the melter vessel. In order to better understand the cause of the larger than normal bed expansion and to develop mitigating techniques, a series of three crucible tests were conducted.

Stone, M.E.

2000-04-04T23:59:59.000Z

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


81

Dynamic modeling and control of a solid-sorbent CO{sub 2} capture process with two-stage bubbling fluidized bed adsorber reactor  

SciTech Connect

Solid-sorbent-based CO{sub 2} capture processes have strong potential for reducing the overall energy penalty for post-combustion capture from the flue gas of a conventional pulverized coal power plant. However, the commercial success of this technology is contingent upon it operating over a wide range of capture rates, transient events, malfunctions, and disturbances, as well as under uncertainties. To study these operational aspects, a dynamic model of a solid-sorbent-based CO{sub 2} capture process has been developed. In this work, a one-dimensional (1D), non-isothermal, dynamic model of a two-stage bubbling fluidized bed (BFB) adsorber-reactor system with overflow-type weir configuration has been developed in Aspen Custom Modeler (ACM). The physical and chemical properties of the sorbent used in this study are based on a sorbent (32D) developed at National Energy Technology Laboratory (NETL). Each BFB is divided into bubble, emulsion, and cloud-wake regions with the assumptions that the bubble region is free of solids while both gas and solid phases coexist in the emulsion and cloud-wake regions. The BFB dynamic model includes 1D partial differential equations (PDEs) for mass and energy balances, along with comprehensive reaction kinetics. In addition to the two BFB models, the adsorber-reactor system includes 1D PDE-based dynamic models of the downcomer and outlet hopper, as well as models of distributors, control valves, and other pressure-drop devices. Consistent boundary and initial conditions are considered for simulating the dynamic model. Equipment items are sized and appropriate heat transfer options, wherever needed, are provided. Finally, a valid pressure-flow network is developed and a lower-level control system is designed. Using ACM, the transient responses of various process variables such as flue gas and sorbent temperatures, overall CO{sub 2} capture, level of solids in the downcomer and hopper have been studied by simulating typical disturbances such as change in the temperature, flowrate, and composition of the flue gas. To maintain the overall CO{sub 2} capture at a desired level in face of the typical disturbances, two control strategies were considered–a proportional-integral-derivative (PID)-based feedback control strategy and a feedforward-augmented feedback control strategy. Dynamic simulation results show that both the strategies result in unacceptable overshoot/undershoot and a long settling time. To improve the control system performance, a linear model predictive controller (LMPC) is designed. In summary, the overall results illustrate how optimizing the operation and control of carbon capture systems can have a significant impact on the extent and the rate at which commercial-scale capture processes will be scaled-up, deployed, and used in the years to come.

Modekurti, S.; Bhattacharyya, D.; Zitney, S.

2012-01-01T23:59:59.000Z

82

Coal Devolatilization in a Moving-Bed Gasifier  

Science Conference Proceedings (OSTI)

During moving-bed coal gasification, coal volatile matter entering the product gas phase affects gas yields and composition. The coal devolatilization database and empirical model developed here can be used to predict the yield and composition of the major coal devolatilization products in moving-bed gasifiers at atmospheric and elevated pressure.

1990-10-15T23:59:59.000Z

83

Health effects models for nuclear power plant accident consequence analysis: Low LET radiation: Part 2, Scientific bases for health effects models  

Science Conference Proceedings (OSTI)

This report provides dose-response models intended to be used in estimating the radiological health effects of nuclear power plant accidents. Models of early and continuing effects, cancers and thyroid nodules, and genetic effects are provided. Two-parameter Weibull hazard functions are recommended for estimating the risks of early and continuing health effects. Three potentially lethal early effects -- the hematopoietic, pulmonary and gastrointestinal syndromes -- are considered. Linear and linear-quadratic models are recommended for estimating cancer risks. Parameters are given for analyzing the risks of seven types of cancer in adults -- leukemia, bone, lung, breast, gastrointestinal, thyroid and ''other''. The category, ''other'' cancers, is intended to reflect the combined risks of multiple myeloma, lymphoma, and cancers of the bladder, kidney, brain, ovary, uterus and cervix. Models of childhood cancers due to in utero exposure are also provided. For most cancers, both incidence and mortality are addressed. Linear and linear-quadratic models are also recommended for assessing genetic risks. Five classes of genetic disease -- dominant, x-linked, aneuploidy, unbalanced translocation and multifactorial diseases --are considered. In addition, the impact of radiation-induced genetic damage on the incidence of peri-implantation embryo losses is discussed. The uncertainty in modeling radiological health risks is addressed by providing central, upper, and lower estimates of all model parameters. Data are provided which should enable analysts to consider the timing and severity of each type of health risk. 22 refs., 14 figs., 51 tabs.

Abrahamson, S.; Bender, M.; Book, S.; Buncher, C.; Denniston, C.; Gilbert, E.; Hahn, F.; Hertzberg, V.; Maxon, H.; Scott, B.

1989-05-01T23:59:59.000Z

84

Packed Bed Combustion: An Overview  

E-Print Network (OSTI)

Packed Bed Combustion: An Overview William Hallett Dept. of Mechanical Engineering Université d'Ottawa - University of Ottawa #12;Packed Bed Combustion - University of Ottawa - CICS 2005 Introduction air fuel feedproducts xbed grate Packed Bed Combustion: fairly large particles of solid fuel on a grate, air supplied

Hallett, William L.H.

85

National SCADA Test Bed | Department of Energy  

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

Services Cybersecurity Energy Delivery Systems Cybersecurity National SCADA Test Bed National SCADA Test Bed Electricity Advisory Committee Transmission Planning...

86

IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY, VOL. 8, NO. 2, MARCH 2000 247 A Model of a Bubbling Fluidized Bed Combustor  

E-Print Network (OSTI)

and the capability of using low quality fuel, such as nonpulverized coal, mine residues and waste. Furthermore Prandoni Abstract--Fluidized bed techniques are employed in coal com- bustion power plants, because to produce gypsum). In conventional combustion chambers, the pulverized coal takes less than a second to burn

Campi, Marco

87

Modeling of the fluidized bed combustion process and NOx emissions using self-organizing maps: An application to the diagnosis of process states  

Science Conference Proceedings (OSTI)

Efforts to reduce harmful emissions and the increasing demands for combustion efficiency have generated a number of challenges for power plants. Changes in the operation of a combustion process, for example, can induce fluctuations that have unexpected ... Keywords: Artificial neural network, Energy production, Fluidized bed, K-means, Nitrogen oxide, Self-organizing map

M. Liukkonen; T. Hiltunen; E. Hälikkä; Y. Hiltunen

2011-05-01T23:59:59.000Z

88

Health effects models for nuclear power plant accident consequence analysis: Modifications of models resulting from recent reports on health effects of ionizing radiation  

Science Conference Proceedings (OSTI)

The Nuclear Regulatory Commission has sponsored several studies to identify and quantify the potential health effects of accidental releases of radionuclides from nuclear power plants. The most recent health effects models resulting from these efforts were published in two reports, NUREG/CR-4214, Rev. 1, Part 1 (1990) and Part 2 (1989). Several major health effects reports have been published recently that may impact the health effects models presented in these reports. This addendum to the Part 2 (1989) report, provides a review of the 1986 and 1988 reports by the United Nations Scientific Committee on the Effects of Atomic Radiation, the National Academy of Sciences/National Research Council BEAR 5 Committee report and Publication 60 of the International Commission on Radiological Protection as they relate to this report. The three main sections of this addendum discuss early occurring and continuing effects, late somatic effects, and genetic effects. The major changes to the NUREG/CR-4214 health effects models recommended in this addendum are for late somatic effects. These changes reflect recent changes in cancer risk factors that have come from longer followup and revised dosimetry in major studies like that on the Japanese A-bomb survivors. The results presented in this addendum should be used with the basic NUREG/CR-4214 reports listed above to obtain the most recent views on the potential health effects of radionuclides released accidentally from nuclear power plants. 48 refs., 4 figs., 24 tabs.

Abrahamson, S. (Wisconsin Univ., Madison, WI (United States)); Bender, M.A. (Brookhaven National Lab., Upton, NY (United States)); Boecker, B.B.; Scott, B.R. (Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States). Inhalation Toxicology Research Inst.); Gilbert, E.S. (Pacific Northwest Lab., Richland, WA (United States))

1991-08-01T23:59:59.000Z

89

Staged fluidized bed  

DOE Patents (OSTI)

Method and apparatus for narrowing the distribution of residence times of any size particle and equalizing the residence times of large and small particles in fluidized beds. Particles are moved up one fluidized column and down a second fluidized column with the relative heights selected to equalize residence times of large and small particles. Additional pairs of columns are staged to narrow the distribution of residence times and provide complete processing of the material.

Mallon, Richard G. (Livermore, CA)

1984-01-01T23:59:59.000Z

90

Comparison of experimental and computed solids motion and bed dynamics for fluidized beds containing obstacles  

SciTech Connect

The ensemble- and time-averaged solids velocity field and bed dynamics in the form of pressure oscillations taken in the University of Illinois at Urbana-Champaign's (UIUC) atmospheric thin (3.81 by 40 cm) bubbling fluidized bed which contained a simulated triangular pitch tube array consisting of five round 5.08 cm diameter cylinders are analyzed in this paper using Argonne National Laboratory's hydrodynamic model FLUFIX implemented on its CRAY-XMP supercomputer. The bed material consisted of soda lime glass beads having a narrow size range averaging 460 {mu}m in diameter. The fluidizing air was introduced at 39 cm/s. Generally correct solids motion is predicted by the FLUFIX computer program. The uncertainties in the UIUC solids motion data vary greatly from location to location; hence, a sensitivity analysis was performed varying the inlet fluidizing gas velocity distribution. A convergence study was performed by varying (1) the size of the mesh used to approximate the obstacles, and (2) the accuracy of the numerical solution. The authors demonstrate essential grid independence for time-averaged axial solids velocities and porosities for the tubes modeled as 2 {times} 2 and 4 {times} 4 squares and a very tight convergence. Good agreement is obtained for the power spectra of the absolute pressure fluctuations using the Fast Fourier Transform (FFT) technique. The computed and experimental major frequencies lie in a relatively narrow range of 2-3 Hz. Computer animations of the computer simulations qualitatively visualize features of the bed dynamics including bubble formation from the tubes, bed expansion and collapse and side-to-side sloshing. Solids motion and the associated bed dynamics are the key to understanding the erosion processes in fluidized-bed combustors. 7 refs., 12 figs., 3 tabs.

Lyczkowski, R.W.; Gamwo, I.K.; Dobran, F. (Argonne National Lab., IL (USA)); Ai, Y.H.; Chao, B.T.; Chen, M.M. (Illinois Univ., Urbana, IL (USA). Dept. of Mechanical and Industrial Engineering)

1991-01-01T23:59:59.000Z

91

Bed drain cover assembly for a fluidized bed  

DOE Patents (OSTI)

A loose fitting movable cover plate (36), suitable for the severe service encountered in a fluidized bed combustor (10), restricts the flow of solids into the combustor drain lines (30) during shutdown of the bed. This cover makes it possible to empty spent solids from the bed drain lines which would otherwise plug the piping between the drain and the downstream metering device. This enables use of multiple drain lines each with a separate metering device for the control of solids flow rate.

Comparato, Joseph R. (Bloomfield, CT); Jacobs, Martin (Hartford, CT)

1982-01-01T23:59:59.000Z

92

Hydrogen storage-bed design for tritium systems test assembly  

DOE Green Energy (OSTI)

The Los Alamos National Laboratory has completed the design of a hydrogen storage bed for the Tritium Systems Test Assembly (TSTA). Our objective is to store hydrogen isotopes as uranium hydrides and recover them by dehydriding. The specific use of the storage bed is to store DT gas as U(D,T)/sub 3/ when it is required for the TSTA. The hydrogen storage bed consists of a primary container in which uranium powder is stored and a secondary container for a second level of safety in gas confinement. The primary container, inlet and outlet gas lines, cartridge heaters, and instrumentation are assembled in the secondary container. The design of the hydrogen storage bed is presented, along with the modeling and analysis of the bed behavior during hydriding-dehydriding cycles.

Cullingford, H.S.; Wheeler, M.G.; McMullen, J.W.

1981-01-01T23:59:59.000Z

93

Fast fluidized bed steam generator  

DOE Patents (OSTI)

A steam generator in which a high-velocity, combustion-supporting gas is passed through a bed of particulate material to provide a fluidized bed having a dense-phase portion and an entrained-phase portion for the combustion of fuel material. A first set of heat transfer elements connected to a steam drum is vertically disposed above the dense-phase fluidized bed to form a first flow circuit for heat transfer fluid which is heated primarily by the entrained-phase fluidized bed. A second set of heat transfer elements connected to the steam drum and forming the wall structure of the furnace provides a second flow circuit for the heat transfer fluid, the lower portion of which is heated by the dense-phase fluidized bed and the upper portion by the entrained-phase fluidized bed.

Bryers, Richard W. (Flemington, NJ); Taylor, Thomas E. (Bergenfield, NJ)

1980-01-01T23:59:59.000Z

94

Coal Bed Methane Primer  

SciTech Connect

During the second half of the 1990's Coal Bed Methane (CBM) production increased dramatically nationwide to represent a significant new source of income and natural gas for many independent and established producers. Matching these soaring production rates during this period was a heightened public awareness of environmental concerns. These concerns left unexplained and under-addressed have created a significant growth in public involvement generating literally thousands of unfocused project comments for various regional NEPA efforts resulting in the delayed development of public and fee lands. The accelerating interest in CBM development coupled to the growth in public involvement has prompted the conceptualization of this project for the development of a CBM Primer. The Primer is designed to serve as a summary document, which introduces and encapsulates information pertinent to the development of Coal Bed Methane (CBM), including focused discussions of coal deposits, methane as a natural formed gas, split mineral estates, development techniques, operational issues, producing methods, applicable regulatory frameworks, land and resource management, mitigation measures, preparation of project plans, data availability, Indian Trust issues and relevant environmental technologies. An important aspect of gaining access to federal, state, tribal, or fee lands involves education of a broad array of stakeholders, including land and mineral owners, regulators, conservationists, tribal governments, special interest groups, and numerous others that could be impacted by the development of coal bed methane. Perhaps the most crucial aspect of successfully developing CBM resources is stakeholder education. Currently, an inconsistent picture of CBM exists. There is a significant lack of understanding on the parts of nearly all stakeholders, including industry, government, special interest groups, and land owners. It is envisioned the Primer would being used by a variety of stakeholders to present a consistent and complete synopsis of the key issues involved with CBM. In light of the numerous CBM NEPA documents under development this Primer could be used to support various public scoping meetings and required public hearings throughout the Western States in the coming years.

Dan Arthur; Bruce Langhus; Jon Seekins

2005-05-25T23:59:59.000Z

95

Fluidized bed boiler feed system  

SciTech Connect

A fluidized bed boiler feed system for the combustion of pulverized coal. Coal is first screened to separate large from small particles. Large particles of coal are fed directly to the top of the fluidized bed while fine particles are first mixed with recycled char, preheated, and then fed into the interior of the fluidized bed to promote char burnout and to avoid elutriation and carryover.

Jones, Brian C. (Windsor, CT)

1981-01-01T23:59:59.000Z

96

Biparticle fluidized bed reactor  

DOE Patents (OSTI)

A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase is described. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves. 3 figures.

Scott, C.D.

1993-12-14T23:59:59.000Z

97

Biparticle fluidized bed reactor  

DOE Patents (OSTI)

A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves.

Scott, Charles D. (Oak Ridge, TN)

1993-01-01T23:59:59.000Z

98

Biparticle fluidized bed reactor  

DOE Patents (OSTI)

A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary and tertiary particulate phases, continuously introduced and removed simultaneously in the cocurrent and countercurrent mode, act in a role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Means for introducing and removing the sorbent phases include feed screw mechanisms and multivane slurry valves.

Scott, Charles D. (Oak Ridge, TN); Marasco, Joseph A. (Kingston, TN)

1996-01-01T23:59:59.000Z

99

Biparticle fluidized bed reactor  

DOE Patents (OSTI)

A fluidized bed reactor system utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves.

Scott, Charles D. (Oak Ridge, TN); Marasco, Joseph A. (Kingston, TN)

1995-01-01T23:59:59.000Z

100

CERTS Microgrid Laboratory Test Bed  

E-Print Network (OSTI)

CERTS Microgrid Laboratory Test Bed R. H. Lasseter, Fellow,play functionality. The tests demonstrated stable behaviorin an autonomous manner. All tests performed as expected and

Lasseter, R. H.

2010-01-01T23:59:59.000Z

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


101

Mange-infested Dog Bedding  

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

NEWTON About NEWTON About Ask A Scientist Education At Argonne Mange-infested Dog Bedding Name: Joan Status: other Grade: 12+ Location: NY Country: USA Date: Summer 2010...

102

Pressurized fluidized bed reactor  

DOE Patents (OSTI)

A pressurized fluid bed reactor power plant includes a fluidized bed reactor contained within a pressure vessel with a pressurized gas volume between the reactor and the vessel. A first conduit supplies primary gas from the gas volume to the reactor, passing outside the pressure vessel and then returning through the pressure vessel to the reactor, and pressurized gas is supplied from a compressor through a second conduit to the gas volume. A third conduit, comprising a hot gas discharge, carries gases from the reactor, through a filter, and ultimately to a turbine. During normal operation of the plant, pressurized gas is withdrawn from the gas volume through the first conduit and introduced into the reactor at a substantially continuously controlled rate as the primary gas to the reactor. In response to an operational disturbance of the plant, the flow of gas in the first, second, and third conduits is terminated, and thereafter the pressure in the gas volume and in the reactor is substantially simultaneously reduced by opening pressure relief valves in the first and third conduits, and optionally by passing air directly from the second conduit to the turbine.

Isaksson, Juhani (Karhula, FI)

1996-01-01T23:59:59.000Z

103

Pressurized fluidized bed reactor  

DOE Patents (OSTI)

A pressurized fluid bed reactor power plant includes a fluidized bed reactor contained within a pressure vessel with a pressurized gas volume between the reactor and the vessel. A first conduit supplies primary gas from the gas volume to the reactor, passing outside the pressure vessel and then returning through the pressure vessel to the reactor, and pressurized gas is supplied from a compressor through a second conduit to the gas volume. A third conduit, comprising a hot gas discharge, carries gases from the reactor, through a filter, and ultimately to a turbine. During normal operation of the plant, pressurized gas is withdrawn from the gas volume through the first conduit and introduced into the reactor at a substantially continuously controlled rate as the primary gas to the reactor. In response to an operational disturbance of the plant, the flow of gas in the first, second, and third conduits is terminated, and thereafter the pressure in the gas volume and in the reactor is substantially simultaneously reduced by opening pressure relief valves in the first and third conduits, and optionally by passing air directly from the second conduit to the turbine. 1 fig.

Isaksson, J.

1996-03-19T23:59:59.000Z

104

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

DOE Green Energy (OSTI)

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

Kevin Whitty

2003-12-01T23:59:59.000Z

105

Granular Dynamics in Pebble Bed Reactor Cores  

E-Print Network (OSTI)

in a pebble-bed nuclear reactor,” Phys. Rev. E, vol. 74, no.cycles of the pebble bed reactor,” Nuclear Engineering andoptimization of pebble-bed reactors,” Annals of Nuclear

Laufer, Michael Robert

2013-01-01T23:59:59.000Z

106

Neutronics analysis of a modified Pebble Bed Advanced High Temperature Reactor.  

E-Print Network (OSTI)

??The objective of this research is to, based on the original design for the Pebble Bed Advanced High Temperature Reactor (PB-AHTR), develop an MCNPX model… (more)

Abejon Orzaez, Jorge

2009-01-01T23:59:59.000Z

107

Identification and predictive control for a circulation fluidized bed boiler  

Science Conference Proceedings (OSTI)

This paper introduces the design and presents the research findings of the identification and control application for an industrial Circulation Fluidized Bed (CFB) boiler. Linear Parameter Varying (LPV) model is used in the model identification where ... Keywords: CFB boilers, Identification, LPV model, Linear models interpolation, MPC

Guoli Ji, Jiangyin Huang, Kangkang Zhang, Yucai Zhu, Wei Lin, Tianxiao Ji, Sun Zhou, Bin Yao

2013-06-01T23:59:59.000Z

108

An examination of the consequences in high consequence operations  

SciTech Connect

Traditional definitions of risk partition concern into the probability of occurrence and the consequence of the event. Most safety analyses focus on probabilistic assessment of an occurrence and the amount of some measurable result of the event, but the real meaning of the ``consequence`` partition is usually afforded less attention. In particular, acceptable social consequence (consequence accepted by the public) frequently differs significantly from the metrics commonly proposed by risk analysts. This paper addresses some of the important system development issues associated with consequences, focusing on ``high consequence operations safety.``

Spray, S.D.; Cooper, J.A.

1996-06-01T23:59:59.000Z

109

Moisture transport in silica gel particle beds  

DOE Green Energy (OSTI)

A theoretical and experimental study of the performance of silica gel packed particle beds is described. A bench-scale test rig was used to obtain data for parameter values pertinent to solar air-conditioning applications. Both adsorption and desorption experiments were performed for Regular Density (RD) silica gel for a wide range of particle size. Adsorption data were also obtained for Intermediate Density (ID) gel. A model of heat and mass transfer in the bed was developed with special attention paid to the modeling of solid side resistance. For this latter purpose an extensive review of the available literature on moisture adsorption and moisture transport in silica gel was made. Both Knudsen and surface diffusion are found to be important mechanisms of moisture transport in Intermediate Density gels while surface diffusion is dominant in Regular Density gels. A general equation for moisture transport in a spherical silica gel particle was developed and was incorporated into the model equations governing heat and mass transfer between the gel particles and air flowing through a packed particle bed. A computer code DESICCANT was written to solve the coupled set of partial differential equations using a finite difference numerical method. The agreement between theory and experiment for adsorption on RD gel is satisfactory, and is somewhat better for the outlet water vapor concentration than for the outlet air temperature. The agreement for desorption from RD gel and adsorption to ID gel is satisfactory, but not as good as for adsorption on RD gel.

Pesaran, A.A.

1983-02-01T23:59:59.000Z

110

National SCADA Test Bed | Department of Energy  

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

Sites Power Marketing Administration Other Agencies You are here Home National SCADA Test Bed National SCADA Test Bed Supervisory Control and Data Acquisition (SCADA) systems...

111

Distribution plate for recirculating fluidized bed  

DOE Patents (OSTI)

A distribution plate for a recirculating fluidized bed has a centrally disposed opening and a plurality of apertures adjacent the periphery to eliminate dead spots within the bed.

Yang, Wen-ching (Export, PA); Vidt, Edward J. (Pittsburgh, PA); Keairns, Dale L. (Pittsburgh, PA)

1977-01-01T23:59:59.000Z

112

Moving granular-bed filter development program. Topical report  

Science Conference Proceedings (OSTI)

Advanced, coal-based, power plants, such as IGCC and Advanced-PFBC, are currently nearing commercial demonstration. These power plant technologies require hot gas filtration as part of their gas cleaning trains. Ceramic barrier filters are the major filter candidates being developed for these hot gas cleaning applications. While ceramic barrier filters achieve high levels of particle removal, concerns exist for their reliability and operability in these applications. An alternative hot gas filtration technology is the moving granular bed filter. An advanced, moving granular bed filter has been conceived, and early development activities performed by the Westinghouse Electric Corporation, Science and Technology Center. This document reports on the Base Contract tasks performed to resolve the barrier technical issues for this technology. The concept, the Standleg Moving Granular Bed Filter (SMGBF) has a concurrent downward, gas and bed media flow configuration that results in simplified features and improved scaleup feasibility compared to alternative designs. Two modes of bed media operation were assessed in the program: once-through using pelletized power plant waste as bed media, and recycle of bed media via standleg and pneumatic transport techniques. Cold Model testing; high-temperature, high-pressure testing; and pelletization testing using advanced power plant wastes, have been conducted in the program. A commercial, economic assessment of the SMGBF technology was performed for IGCC and Advanced-PFBC applications. The evaluation shows that the barrier technical issues can be resolved, and that the technology is potentially competitive with ceramic barrier filters.

Newby, R.A.; Yang, W.C.; Smeltzer, E.E.; Lippert, T.E.

1994-04-01T23:59:59.000Z

113

Simulation of a High Efficiency Multi-bed Adsorption Heat Pump  

Science Conference Proceedings (OSTI)

Attaining high energy efficiency with adsorption heat pumps is challenging due to thermodynamic losses that occur when the sorbent beds are thermally cycled without effective heat recuperation. The multi-bed concept described here effectively transfers heat from beds being cooled to beds being heated, which enables high efficiency in thermally driven heat pumps. A simplified lumped-parameter model and detailed finite element analysis are used to simulate the performance of an ammonia-carbon sorption compressor, which is used to project the overall heat pump coefficient of performance. The effects of bed geometry and number of beds on system performance are explored, and the majority of the performance benefit is obtained with four beds. Results indicate that a COP of 1.24 based on heat input is feasible at AHRI standard test conditions for residential HVAC equipment. When compared on a basis of primary energy input, performance equivalent to SEER 13 or 14 are theoretically attainable with this system.

TeGrotenhuis, Ward E.; Humble, Paul H.; Sweeney, J. B.

2012-05-01T23:59:59.000Z

114

Effect of bed pressure drop on performance of a CFB boiler  

Science Conference Proceedings (OSTI)

The effect of bed pressure drop and bed inventory on the performances of a circulating fluidized bed (CFB) boiler was studied. By using the state specification design theory, the fluidization state of the gas-solids flow in the furnace of conventional CFB boilers was reconstructed to operate at a much lower bed pressure drop by reducing bed inventory and control bed quality. Through theoretical analysis, it was suggested that there would exist a theoretical optimal value of bed pressure drop, around which the boiler operation can achieve the maximal combustion efficiency and with significant reduction of the wear of the heating surface and fan energy consumption. The analysis was validated by field tests carried out in a 75 t/h CFB boiler. At full boiler load, when bed pressure drop was reduced from 7.3 to 3.2 kPa, the height of the dense zone in the lower furnace decreased, but the solid suspension density profile in the upper furnace and solid flow rate were barely influenced. Consequently, the average heat transfer coefficient in the furnace was kept nearly the same and the furnace temperature increment was less than 17{sup o}C. It was also found that the carbon content in the fly ash decreased first with decreasing bed pressure drop and then increased with further increasing bed pressure drop. The turning point with minimal carbon content was referred to as the point with optimal bed pressure drop. For this boiler, at the optimum point the bed pressure was around 5.7 kPa with the overall excess air ratio of 1.06. When the boiler was operated around this optimal point, not only the combustion efficiency was improved, but also fan energy consumption and wear of heating surface were reduced. 23 refs., 6 figs., 4 tabs.

Hairui Yang; Hai Zhang; Shi Yang; Guangxi Yue; Jun Su; Zhiping Fu [Tsinghua University, Beijing (China). Department of Thermal Engineering

2009-05-15T23:59:59.000Z

115

CERTS Microgrid Laboratory Test Bed  

E-Print Network (OSTI)

1. CERTS Microgrid Test Bed at American Electric Power PhotoCredit: American Electric Power Figure 2. One-Line DiagramVOLKOMMER, American Electric Power, USA E. LINTON AND HECTOR

Eto, Joe

2009-01-01T23:59:59.000Z

116

CERTS Microgrid Laboratory Test Bed  

E-Print Network (OSTI)

Test Bed at American Electric Power Figure 2. One-LineH. VOLKOMMER, American Electric Power, USA E. LINTON AND H.and operated by American Electric Power. The testing fully

ETO, J.

2010-01-01T23:59:59.000Z

117

CERTS Microgrid Laboratory Test Bed  

E-Print Network (OSTI)

on Power Delivery CERTS Microgrid Laboratory Test Bed R. H.and J. Roy Abstract--. CERTS Microgrid concept captures theas a subsystem or a “microgrid”. The sources can operate in

Lasseter, R. H.

2010-01-01T23:59:59.000Z

118

An Evaluation of Mesoscale Model Predictions of Down-Valley and Canyon Flows and Their Consequences Using Doppler Lidar Measurements during VTMX 2000  

Science Conference Proceedings (OSTI)

A mesoscale model, a Lagrangian particle dispersion model, and extensive Doppler lidar wind measurements during the Vertical Transport and Mixing (VTMX) 2000 field campaign were used to examine converging flows over the Salt Lake valley in Utah ...

Jerome D. Fast; Lisa S. Darby

2004-04-01T23:59:59.000Z

119

Hydrological consequences of global warming  

Science Conference Proceedings (OSTI)

The 2007 Intergovernmental Panel for Climate Change indicates there is strong evidence that the atmospheric concentration of carbon dioxide far exceeds the natural range over the last 650,000 years, and this recent warming of the climate system is unequivocal, resulting in more frequent extreme precipitation events, earlier snowmelt runoff, increased winter flood likelihoods, increased and widespread melting of snow and ice, longer and more widespread droughts, and rising sea level. The effects of recent warming has been well documented and climate model projections indicate a range of hydrological impacts with likely to very likely probabilities (67 to 99 percent) of occurring with significant to severe consequences in response to a warmer lower atmosphere with an accelerating hydrologic cycle.

Miller, Norman L.

2009-06-01T23:59:59.000Z

120

Dual Fluidized Bed Biomass Gasification  

DOE Green Energy (OSTI)

The dual fluidized bed reactor is a recirculating system in which one half of the unit operates as a steam pyrolysis device for biomass. The pyrolysis occurs by introducing biomass and steam to a hot fluidized bed of inert material such as coarse sand. Syngas is produced during the pyrolysis and exits the top of the reactor with the steam. A crossover arm, fed by gravity, moves sand and char from the pyrolyzer to the second fluidized bed. This sand bed uses blown air to combust the char. The exit stream from this side of the reactor is carbon dioxide, water and ash. There is a second gravity fed crossover arm to return sand to the pyrolysis side. The recirculating action of the sand and the char is the key to the operation of the dual fluidized bed reactor. The objective of the project was to design and construct a dual fluidized bed prototype reactor from literature information and in discussion with established experts in the field. That would be appropriate in scale and operation to measure the relative performance of the gasification of biomass and low ranked coals to produce a high quality synthesis gas with no dilution from nitrogen or combustion products.

None

2005-09-30T23:59:59.000Z

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


121

Rapid ignition of fluidized bed boiler  

DOE Patents (OSTI)

A fluidized bed boiler is started up by directing into the static bed of inert and carbonaceous granules a downwardly angled burner so that the hot gases cause spouting. Air is introduced into the bed at a rate insufficient to fluidize the entire bed. Three regions are now formed in the bed, a region of lowest gas resistance, a fluidized region and a static region with a mobile region at the interface of the fluidized and static regions. Particles are transferred by the spouting action to form a conical heap with the carbonaceous granules concentrated at the top. The hot burner gases ignite the carbonaceous matter on the top of the bed which becomes distributed in the bed by the spouting action and bed movement. Thereafter the rate of air introduction is increased to fluidize the entire bed, the spouter/burner is shut off, and the entire fluidized bed is ignited.

Osborn, Liman D. (Alexandria, VA)

1976-12-14T23:59:59.000Z

122

Bed-inventory Overturn Mechanism for Pant-leg Circulating Fluidized Bed Boilers  

E-Print Network (OSTI)

A numerical model was established to investigate the lateral mass transfer as well as the mechanism of bed-inventory overturn inside a pant-leg circulating fluidized bed (CFB), which are of great importance to maintain safe and efficient operation of the CFB. Results show that the special flow structure in which the solid particle volume fraction along the central line of the pant-leg CFB is relative high enlarges the lateral mass transfer rate and make it more possible for bed inventory overturn. Although the lateral pressure difference generated from lateral mass transfer inhibits continuing lateral mass transfer, providing the pant-leg CFB with self-balancing ability to some extent, the primary flow rate change due to the outlet pressure change often disable the self-balancing ability by continually enhancing the flow rate difference. As the flow rate of the primary air fan is more sensitive to its outlet pressure, it is easier to lead to bed inventory overturn. While when the solid particle is easier to c...

Wang, Zhe; Yang, Zhiwei; West, Logan; Li, Zheng

2011-01-01T23:59:59.000Z

123

Development of Risk Assessment System for Coal-Bed Methane Underbalanced Drilling  

Science Conference Proceedings (OSTI)

As there are a lot of factors with complexity and uncertainty, the process of coal-bed methane under balanced drilling has great risk. In order to overcome the one-sidedness and limitation caused by single evaluation method, the combined evaluation model ... Keywords: coal-bed methane, underbalanced drilling, combined evaluation model, risk assessment system

Xiujuan Yang; Qingyang Wen; Xiangzhen Yan; Yan Xia

2010-12-01T23:59:59.000Z

124

Simulation of a moving bed gasifier for a western coal  

Science Conference Proceedings (OSTI)

This paper describes an adiabatic steady state plug flow model for a moving bed coal gasifier with gas-solid heat transfer. The model considers 17 solid stream components, 10 gas stream components and 17 reactions. The kinetic and thermodynamic parameters ...

R. Stillman

1979-05-01T23:59:59.000Z

125

Biofiltration of isopentane in peat and compost packed beds  

Science Conference Proceedings (OSTI)

Commercially available biofiltration systems have used natural bioactive materials in packed beds due to low media cost and easy availability. Detailed understanding and modeling of biofiltration systems are lacking in existing literature. Experimental studies on the isopentane treatment in air using peat- and compost-packed beds were conducted with inlet isopentane concentrations of 360 to 960 ppmv, and empty-bed gas-phase residence times of 2 to 10 min. High removal efficiencies (>90%) were achieved at low contaminant concentrations (8 min). For both peat and compost biofilters, there was an optimal water content that gave the highest removal efficiency. For higher water content, mass transfer of isopentane through the liquid phase controlled the biofiltration removal efficiency. At low water content, irreversible changes in the bioactivity of peat and compost occurred, resulting in an irrecoverable loss of removal efficiency. Increases in biofilter bed temperature from 25 to 40 C improved the removal efficiency. A mathematical model incorporating the effect of water content and temperature was developed to describe the packed-bed biofilter performance. Model predictions agreed closely with experimental data.

Wang, Z.; Govind, R. [Univ. of Cincinnati, OH (United States). Dept. of Chemical Engineering

1997-05-01T23:59:59.000Z

126

Simulation of transport dynamics in fluidized-bed dryers  

SciTech Connect

A mathematical model for predicting three-dimensional, two-phase flow, heat and mass transfer inside fluidized-bed dryers has been developed. The model consists of the full set of partial-differential equations that describe the conservation of mass, momentum and energy for both phases inside the dryer, and is coupled with correlations concerning interphase momentum-, heat-, and mass-transfer. It is shown that the model can predict the most important engineering aspects of a fluidized-bed dryer including pressure drop, particle holdup, temperature distribution in both phases as well as drying efficiency all over the fluidized-bed. Plug-flow conditions are predicted for the gas phase, while back-mixing is predicted for the particles. The effect of particle mass-flow-rate on fluidized-bed dryer performance is evaluated. It is shown that the lower the particle mass flow-rate, the more intense the horizontal moisture gradients, while the higher the particle rate the more uniform the moisture distribution throughout the bed.

Theologos, K.N.; Maroulis, Z.B.; Markatos, N.C. [National Technical Univ. of Athens (Greece). Chemical Engineering Dept.

1997-05-01T23:59:59.000Z

127

Modular hydride beds for mobile applications  

DOE Green Energy (OSTI)

Design, construction, initial testing and simple thermal modeling of modular, metal hydride beds have been completed. Originally designed for supplying hydrogen to a fuel cell on a mobile vehicle, the complete bed design consists of 8 modules and is intended for use on the Palm Desert Vehicle (PDV) under development at the Schatz Energy Center, Humbolt State University. Each module contains approximately 2 kg of a commercially available, low temperature, hydride-forming metal alloy. Waste heat from the fuel cell in the form of heated water is used to desorb hydrogen from the alloy for supplying feed hydrogen to the fuel cell. In order to help determine the performance of such a modular bed system, six modules were constructed and tested. The design and construction of the modules is described in detail. Initial testing of the modules both individually and as a group showed that each module can store {approximately} 30 g of hydrogen (at 165 PSIA fill pressure, 17 C), could be filled with hydrogen in 6 minutes at a nominal, 75 standard liters/min (slm) fueling rate, and could supply hydrogen during desorption at rates of 25 slm, the maximum anticipated hydrogen fuel cell input requirement. Tests made of 5 modules as a group indicated that the behavior of the group run in parallel both in fueling and gas delivery could be directly predicted from the corresponding, single module characteristics by using an appropriate scaling factor. Simple thermal modeling of a module as an array of cylindrical, hydride-filled tubes was performed. The predictions of the model are in good agreement with experimental data.

Malinowski, M.E.; Stewart, K.D.

1997-08-01T23:59:59.000Z

128

Particle Bed Reactor scaling relationships  

DOE Green Energy (OSTI)

Scaling relationships for Particle Bed Reactors (PBRs) are discussed. The particular applications are short duration systems, i.e., for propulsion or burst power. Particle Bed Reactors can use a wide selection of different moderators and reflectors and be designed for such a wide range of power and bed power densities. Additional design considerations include the effect of varying the number of fuel elements, outlet Mach number in hot gas channel, etc. All of these variables and options result in a wide range of reactor weights and performance. Extremely light weight reactors (approximately 1 kg/MW) are possible with the appropriate choice of moderator/reflector and power density. Such systems are very attractive for propulsion systems where parasitic weight has to be minimized.

Slovik, G.; Araj, K.; Horn, F.L.; Ludewig, H.; Benenati, R.

1987-01-01T23:59:59.000Z

129

Apparatus and process for controlling fluidized beds  

DOE Patents (OSTI)

An apparatus and process for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance.

Rehmat, Amirali G. (Westmont, IL); Patel, Jitendra G. (Bolingbrook, IL)

1985-10-01T23:59:59.000Z

130

Fluidised Bed Technology for Gold Ore and Gold Concentrate  

Science Conference Proceedings (OSTI)

Presentation Title, Fluidised Bed Technology for Gold Ore and Gold Concentrate. Author(s) ... such as the circulating fluidised bed and the bubbling fluidized bed.

131

Argonne CNM News: Structural Consequences of Nanolithography  

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

Structural Consequences of Nanolithography Structural Consequences of Nanolithography Ferroelectric domains written by PFM Ferroelectric domains written by PFM exhibit a subtle structural distortion that can be directly observed using hard X-ray nanodiffraction microscopy. Nanolithography effect on structure Modeling shows that the writing process induces a structural electromechanical response to unscreened charges at surfaces and interfaces, altering the local free energy of written ferroelectric domains. Users from the University of Wisconsin-Madison and the Center for Nanophase Materials Science, working with the X-Ray Microscopy Group, have discovered structural effects accompanying the nanoscale lithography of ferroelectric polarization domains. The results shed new light on the physics of

132

Staged cascade fluidized bed combustor  

DOE Patents (OSTI)

A fluid bed combustor comprising a plurality of fluidized bed stages interconnected by downcomers providing controlled solids transfer from stage to stage. Each stage is formed from a number of heat transfer tubes carried by a multiapertured web which passes fluidizing air to upper stages. The combustor cross section is tapered inwardly from the middle towards the top and bottom ends. Sorbent materials, as well as non-volatile solid fuels, are added to the top stages of the combustor, and volatile solid fuels are added at an intermediate stage.

Cannon, Joseph N. (4103 Farragut St., Hyattsville, MD 20781); De Lucia, David E. (58 Beacon St., Apt. No. 2, Boston, MA 02108); Jackson, William M. (5300 McArthur Blvd., NW., Washington, DC 20016); Porter, James H. (P.O. Box 1131, Daggett Ave., Vineyard Haven, MA 02568)

1984-01-01T23:59:59.000Z

133

6, 1181711843, 2006 consequences of  

E-Print Network (OSTI)

-size bombs (less than 0.03% of the explosive yield of the current global nuclear arsenal) on cities in5ACPD 6, 11817­11843, 2006 Climatic consequences of regional nuclear conflicts A. Robock et al Chemistry and Physics Discussions Climatic consequences of regional nuclear conflicts A. Robock 1 , L. Oman

Paris-Sud XI, Université de

134

Char binder for fluidized beds  

SciTech Connect

An arrangement that utilizes agglomerating coal as a binder to bond coal fines and recycled char into an agglomerate mass that will have suitable retention time when introduced into a fluidized bed 14 for combustion. The simultaneous use of coal for a primary fuel and as a binder effects significant savings in the elimination of non-essential materials and processing steps.

Borio, Richard W. (Somers, CT); Accortt, Joseph I. (Simsbury, CT)

1981-01-01T23:59:59.000Z

135

Pressurized fluidized-bed combustion  

SciTech Connect

If pressurised fluidised-bed combustion is to be used in combined cycle electricity generation, gas turbines must be made reliable and flue gas emission standards must be met. This report examines the issues of particulate cleaning before the turbine and stack, as well as recent work on the development of advanced gas filters.

Yeager, K.

1983-06-01T23:59:59.000Z

136

Combined characteristics and finite volume methods for sediment transport and bed morphology in surface water flows  

Science Conference Proceedings (OSTI)

Abstract: We propose a new numerical method for solving the equations of coupled sediment transport and bed morphology by free-surface water flows. The mathematical formulation of these models consists of the shallow water equations for the hydraulics, ... Keywords: Bed morphology, Finite volume scheme, Method of characteristics, Sediment transport, Shallow water equations

Fayssal Benkhaldoun; Mohammed Seaïd

2011-06-01T23:59:59.000Z

137

The Performance of Classical versus Modern Finite-Volume Advection Schemes for Atmospheric Modeling in a One-Dimensional Test-bed  

Science Conference Proceedings (OSTI)

The numerical solution of the transport (i.e., the continuity) equation for trace species, particularly in three-dimensional circulation models, has recently received great attention. Two different approaches are common. First, the classical ...

Rolf Müller

1992-07-01T23:59:59.000Z

138

Attrition Resistant Catalyst Materials for Fluid Bed ...  

Biomass and Biofuels Attrition Resistant Catalyst Materials for Fluid Bed Applications National Renewable Energy Laboratory. Contact NREL About This ...

139

Accelerated Weathering of Fluidized Bed Steam Reformation ...  

Science Conference Proceedings (OSTI)

Sep 16, 2007 ... Accelerated Weathering of Fluidized Bed Steam Reformation Material Under Hydraulically Unsaturated Conditions by E.M. Pierce ...

140

Sensitivity of North American agriculture to ENSO-based climate scenarios and their socio-economic consequences: Modeling in an integrated assessment framework  

Science Conference Proceedings (OSTI)

A group of Canadian, US and Mexican natural resource specialists, organized by the Pacific Northwest National Laboratory (PNNL) under its North American Energy, Environment and Economy (NA3E) Program, has applied a simulation modeling approach to estimating the impact of ENSO-driven climatic variations on the productivity of major crops grown in the three countries. Methodological development is described and results of the simulations presented in this report. EPIC (the Erosion Productivity Impact Calculator) was the agro-ecosystem model selected-for this study. EPIC uses a daily time step to simulate crop growth and yield, water use, runoff and soil erosion among other variables. The model was applied to a set of so-called representative farms parameterized through a specially-assembled Geographic Information System (GIS) to reflect the soils, topography, crop management and weather typical of the regions represented. Fifty one representative farms were developed for Canada, 66 for the US and 23 for Mexico. El Nino-Southern Oscillation (ENSO) scenarios for the EPIC simulations were created using the historic record of sea-surface temperature (SST) prevailing in the eastern tropical Pacific for the period October 1--September 30. Each year between 1960 and 1989 was thus assigned to an ENSO category or state. The ENSO states were defined as El Nino (EN, SST warmer than the long-term mean), Strong El Nino (SEN, much warmer), El Viejo (EV, cooler) and Neutral (within {+-}0.5 C of the long-term mean). Monthly means of temperature and precipitation were then calculated at each farm for the period 1960--1989 and the differences (or anomalies) between the means in Neutral years and EN, SEN and EV years determined. The average monthly anomalies for each ENSO state were then used to create new monthly statistics for each farm and ENSO-state combination. The adjusted monthly statistics characteristic of each ENSO state were then used to drive a stochastic-weather simulator that provided 30 years of daily-weather data needed to run EPIC. Maps and tables of the climate anomalies by farm show climatic conditions that differ considerably by region, season and ENSO state.

Rosenberg, N.J.; Izaurralde, R.C.; Brown, R.A.; Sands, R.D. [Pacific Northwest National Lab., Richland, WA (United States); Legler, D. [Florida State Univ., Tallahassee, FL (United States). Center for Ocean Atmosphere Prediction Studies; Srinivasan, R. [Texas A and M Univ., College Station, TX (United States). Blacklands Research Center; Tiscareno-Lopez, M.

1997-09-01T23:59:59.000Z

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


141

CIRCULATING MOVING BED COMBUSTION PROOF OF CONCEPT  

Science Conference Proceedings (OSTI)

Circulating Moving Bed (CMB) combustion technology has its roots in traditional circulating fluidized bed technology and involves a novel method of solid fuel combustion and heat transfer. CMB technology represents a step change in improved performance and cost relative to conventional PC and FBC boilers. The CMB heat exchanger preheats the energy cycle working fluid, steam or air, to the high temperature levels required in systems for advanced power generation. Unique features of the CMB are the reduction of the heat transfer surfaces by about 60% as a result of the enhanced heat transfer rates, flexibility of operation, and about 30% lower cost over existing technology. The CMB Phase I project ran from July 2001 through March 2003. Its objective was to continue development of the CMB technology with a series of proof of concept tests. The tests were conducted at a scale that provided design data for scale up to a demonstration plant. These objectives were met by conducting a series of experiments in ALSTOM Power’s Multi-use Test Facility (MTF). The MTF was modified to operate under CMB conditions of commercial interest. The objective of the tests were to evaluate gas-to-solids heat transfer in the upper furnace, assess agglomeration in the high temperature CMB bubbling bed, and evaluate solids-to-tube heat transfer in the moving bed heat exchanger. The Phase I program results showed that there are still some significant technical uncertainties that needed to be resolved before the technology can be confidently scaled up for a successful demonstration plant design. Work remained in three primary areas: • scale up of gas to solid heat transfer • high temperature finned surface design • the overall requirements of mechanical and process design. The CMB Phase II workscope built upon the results of Phase I and specifically addressed the remaining technical uncertainties. It included a scaled MTF heat transfer test to provide the necessary data to scale up gas-to-solids heat transfer. A stress test rig was built and tested to provide validation data for a stress model needed to support high temperature finned surface design. Additional cold flow model tests and MTF tests were conducted to address mechanical and process design issues. This information was then used to design and cost a commercial CMB design concept. Finally, the MBHE was reconfigured into a slice arrangement and tested for an extended duration at a commercial CFB plant.

Jukkola, Glen

2010-06-30T23:59:59.000Z

142

COMPUTER SIMULATIONS AND MODELLING IN MATHEMATICS EDUCATION Michael Hardiker B.Sc(Monash), Dip.Ed, B.Ed, M.Ed(Latrobe)  

E-Print Network (OSTI)

theory posed in a periodic heterogeneous domain. This equation models the stability of nuclear reactor Introduction The power distribution in a nuclear reactor is determined by solving a linear transport spectral and Technology. Vol.6, Springer Verlag, Berlin, 1993. [16] V. Deniz, The theory of neutron leakage in reactor

Spagnolo, Filippo

143

Rock bed storage with heat pump. Final report  

SciTech Connect

The study, Rock Bed Storage with Heat Pump, established the feasibility of mating a heat pump to a rock bed storage to effect optimal performance at the lowest cost in single family residences. The operating characteristics of off-the-shelf components of heat pump/rock bed storage systems were studied, and the results were used to formulate configurations of representative systems. These systems were modeled and subsequently analyzed using the TRNSYS computer program and a life cycle cost analysis program called LCCA. A detailed load model of a baseline house was formulated as part of the TRNSYS analysis. Results of the analysis involved the development of a technique to confine the range of heat pump/rock bed storage systems to those systems which are economical for a specific location and set of economic conditions. Additionally, the results included a comparison of the detailed load model with simple UA models such as the ASHRAE bin method. Several modifications and additions were made to the TRNSYS and LCCA computer programs during the course of the study.

Remmers, H.E.; Mills, G.L.

1979-05-01T23:59:59.000Z

144

CERTS Microgrid Laboratory Test Bed  

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

CERTS Microgrid Laboratory Test Bed CERTS Microgrid Laboratory Test Bed Title CERTS Microgrid Laboratory Test Bed Publication Type Journal Article LBNL Report Number LBNL-3553E Year of Publication 2011 Authors Lasseter, Robert H., Joseph H. Eto, Ben Schenkman, John Stevens, Harry T. Volkommer, David Klapp, Ed Linton, Hector Hurtado, and Joyashree Roy Journal IEEE Transactions on Power Delivery Volume 26 Start Page 325 Issue 1 Date Published 01/2011 Keywords distributed energy resources (der) Abstract CERTS Microgrid concept captures the emerging potential of distributed generation using a system approach. CERTS views generation and associated loads as a subsystem or a "microgrid". The sources can operate in parallel to the grid or can operate in island, providing UPS services. The system can disconnect from the utility during large events (i.e. faults, voltage collapses), but may also intentionally disconnect when the quality of power from the grid falls below certain standards. CERTS Microgrid concepts were demonstrated at a full-scale test bed built near Columbus, Ohio and operated by American Electric Power. The testing fully confirmed earlier research that had been conducted initially through analytical simulations, then through laboratory emulations, and finally through factory acceptance testing of individual microgrid components. The islanding and resynchronization method met all Institute of Electrical and Electronics Engineers Standard 1547 and power quality requirements. The electrical protection system was able to distinguish between normal and faulted operation. The controls were found to be robust under all conditions, including difficult motor starts and high impedance faults. Keywords: CHP, UPS, distributed generation, intentional islanding, inverters, microgrid, CERTS, power vs. frequency droop, voltage droop.

145

Dynometer test bed (fact sheet)  

SciTech Connect

The National Renewable Energy Laboratory's (NREL's) Dynamometer Test Bed is one of a kind. It offers wind industry engineers a unique opportunity to conduct lifetime endurance tests on a wide range of wind turbine drivetrains and gearboxes at various speeds, using low or high torque. By testing full-scale wind turbines, engineers from NREL and industry hope to understand the impact of various wind conditions with the goal of improving hardware design.

O' Dell, K.

2000-04-24T23:59:59.000Z

146

Multiscale Analysis of Pebble Bed Reactors  

SciTech Connect

– The PEBBED code was developed at the Idaho National Laboratory for design and analysis of pebble-bed high temperature reactors. The diffusion-depletion-pebble-mixing algorithm of the original PEBBED code was enhanced through coupling with the THERMIX-KONVEK code for thermal fluid analysis and by the COMBINE code for online cross section generation. The COMBINE code solves the B-1 or B-3 approximations to the transport equation for neutron slowing down and resonance interactions in a homogeneous medium with simple corrections for shadowing and thermal self-shielding. The number densities of materials within specified regions of the core are averaged and transferred to COMBINE from PEBBED for updating during the burnup iteration. The simple treatment of self-shielding in previous versions of COMBINE led to inaccurate results for cross sections and unsatisfactory core performance calculations. A new version of COMBINE has been developed that treats all levels of heterogeneity using the 1D transport code ANISN. In a 3-stage calculation, slowing down is performed in 167 groups for each homogeneous subregion (kernel, particle layers, graphite shell, control rod absorber annulus, etc.) Particles in a local average pebble are homogenized using ANISN then passed to the next (pebble) stage. A 1D transport solution is again performed over the pebble geometry and the homogenized pebble cross sections are passed to a 1-d radial model of a wedge of the pebble bed core. This wedge may also include homogeneous reflector regions and a control rod region composed of annuli of different absorbing regions. Radial leakage effects are therefore captured with discrete ordinates transport while axial and azimuthal effects are captured with a transverse buckling term. In this paper, results of various PBR models will be compared with comparable models from literature. Performance of the code will be assessed.

Hans Gougar; Woo Yoon; Abderrafi Ougouag

2010-10-01T23:59:59.000Z

147

Joint NOAA, Navy, NASA Hurricane Test Bed Terms of Reference  

E-Print Network (OSTI)

(JHT) to advance the transfer of new research and technology into operational hurricane prediction. The JHT will routinely serve as a conduit between the operational, academic, and research communities. This facility will be located at the National Hurricane Center (NHC) in Miami, FL. Whereas the operational center and associated personnel could be the NHC, the Joint Typhoon Warning Center (JTWC, Navy), or the Central Pacific Hurricane Center (CPHC), and NHC will be specified in this document, both for brevity and to acknowledge the current focus of the JHT on that organization. Use of other facilities is possible depending on requirements, workload, and opportunity. II. Mission Statement The mission of the Joint (NOAA, Navy, and NASA) Hurricane Test Bed is to transfer more rapidly and smoothly new technology, research results, and observational advances of the USWRP, its sponsoring agencies, the academic community and other groups into improved tropical cyclone analysis and prediction at operational centers. III. Concept of Operations The JHT is the initial test bed activity funded by the USWRP and is established to accelerate the technology infusion focused on hurricane analysis and prediction. Until all test beds are organized under a national test bed activity, the USWRP Interagency Program Office (IPO) provides coordination and oversight. The USWRP/IPO will facilitate outreach, the proposal process, and interaction with the oversight board, funding, and other tasks common to the test beds. The JHT will work with the USWRP/IPO to accomplish those tasks appropriate for administration of the hurricane test bed. The JHT mission will be accomplished by the following: • assessing scientific breakthroughs and new techniques to identify advanced, realtime, data-analysis techniques, forecast models, and observational systems that have potential for significantly improving the forecast guidance provided to hurricane forecasters; completing tests of the codes, products, and observations in a quasi-operational information technology (IT) environment subject to metrics that mandate good scientific performance while meeting ease-of use criteria and time constraints;

unknown authors

2012-01-01T23:59:59.000Z

148

Scaling of pressurized fluidized beds. First quarterly progress report, October 1, 1992--January 15, 1993  

Science Conference Proceedings (OSTI)

Some preliminary work has been done to develop potential cold scale model designs to simulate the bed hydrodynamics of the American Electric Power Tidd pressurized bubbling fluidized bed combustor. The first design is based on the full set of scaling parameters presented in Equation (1), the second design was developed using the simplified set of scaling parameters given in Equation (2). The first design is roughly a 1:1 representation of a section of the core of the Tidd bed combustor. The additional flexibility provided by the simplified set of scaling parameters is particularly useful for developing experimental models of pressurized fluidized bed combustors where the full set of scaling relationships does not provide any reduction in the size of the models. Both the full and the simplified set of scaling relationships have been verified for applications to circulating fluidized bed combustors operating at atmospheric pressure. Currently there is a interest in fluidized bed combustors which operate at elevated pressures ({approximately}12 atm) for combined-cycle applications. One of the primary goals of this stud r is to verify both the till set and the simplified set of scaling relationships for applications to pressurized bubbling fluidized bed combustors.

Glicksman, L.; Farrell, P.

1993-09-01T23:59:59.000Z

149

Gas distributor for fluidized bed coal gasifier  

DOE Patents (OSTI)

A gas distributor for distributing high temperature reaction gases to a fluidized bed of coal particles in a coal gasification process. The distributor includes a pipe with a refractory reinforced lining and a plurality of openings in the lining through which gas is fed into the bed. These feed openings have an expanding tapered shape in the downstream or exhaust direction which aids in reducing the velocity of the gas jets as they enter the bed.

Worley, Arthur C. (Mt. Tabor, NJ); Zboray, James A. (Irvine, CA)

1980-01-01T23:59:59.000Z

150

Battery using a metal particle bed electrode  

DOE Patents (OSTI)

A zinc-air battery in a case is described including a zinc particle bed supported adjacent the current feeder and diaphragm on a porous support plate which holds the particles but passes electrolyte solution. Electrolyte is recycled through a conduit between the support plate and top of the bed by convective forces created by a density of differential caused by a higher concentration of high density discharge products in the interstices of the bed than in the electrolyte recycle conduit. 7 figures.

Evans, J.V.; Savaskan, G.

1991-04-09T23:59:59.000Z

151

Battery using a metal particle bed electrode  

DOE Patents (OSTI)

A zinc-air battery in a case including a zinc particle bed supported adjacent the current feeder and diaphragm on a porous support plate which holds the particles but passes electrolyte solution. Electrolyte is recycled through a conduit between the support plate and top of the bed by convective forces created by a density of differential caused by a higher concentration of high density discharge products in the interstices of the bed than in the electrolyte recycle conduit.

Evans, James V. (Piedmont, CA); Savaskan, Gultekin (Albany, CA)

1991-01-01T23:59:59.000Z

152

Coal bed methane reservoir simulation studies.  

E-Print Network (OSTI)

??The purpose of this study is to perform simulation studies for a specific coal bed methane reservoir. First, the theory and reservoir engineering aspects of… (more)

Karimi, Kaveh

2005-01-01T23:59:59.000Z

153

Combined fluidized bed retort and combustor  

DOE Patents (OSTI)

The present invention is directed to a combined fluidized bed retorting and combustion system particularly useful for extracting energy values from oil shale. The oil-shale retort and combustor are disposed side-by-side and in registry with one another through passageways in a partition therebetween. The passageways in the partition are submerged below the top of the respective fluid beds to preclude admixing or the product gases from the two chambers. The solid oil shale or bed material is transported through the chambers by inclining or slanting the fluidizing medium distributor so that the solid bed material, when fluidized, moves in the direction of the downward slope of the distributor.

Shang, Jer-Yu (Fairfax, VA); Notestein, John E. (Morgantown, WV); Mei, Joseph S. (Morgantown, WV); Zeng, Li-Wen (Morgantown, WV)

1984-01-01T23:59:59.000Z

154

Packed fluidized bed blanket for fusion reactor  

DOE Patents (OSTI)

A packed fluidized bed blanket for a fusion reactor providing for efficient radiation absorption for energy recovery, efficient neutron absorption for nuclear transformations, ease of blanket removal, processing and replacement, and on-line fueling/refueling. The blanket of the reactor contains a bed of stationary particles during reactor operation, cooled by a radial flow of coolant. During fueling/refueling, an axial flow is introduced into the bed in stages at various axial locations to fluidize the bed. When desired, the fluidization flow can be used to remove particles from the blanket.

Chi, John W. H. (Mt. Lebanon, PA)

1984-01-01T23:59:59.000Z

155

Status of granular bed filter development program  

SciTech Connect

The objective of this project was to design and develop moving bed granular filters and ceramic candle filters for particulate control from combined cycle systems. Results are described.

Wilson, K.B.; Haas, J.C.; Prudhomme, J.

1995-11-01T23:59:59.000Z

156

Liquid flow through a reactive packed bed.  

E-Print Network (OSTI)

??The flow phenomena of liquid iron and slag in the lower zone of an iron making blast furnace influences the permeability of the coke bed,… (more)

George, Hazem Labib

2013-01-01T23:59:59.000Z

157

Consequence Management, Safeguards & Non-Proliferation Tools...  

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

Consequence Management, Safeguards, and Non-Proliferation Tools SHARE Consequence Management, Safeguards and Non-Proliferation Tools UF 6 Enrichment Facility Visualization of the...

158

Pressurized fluidized-bed combustion  

Science Conference Proceedings (OSTI)

The US DOE pressurized fluidized bed combustion (PFBC) research and development program is designed to develop the technology and data base required for the successful commercialization of the PFBC concept. A cooperative program with the US, West Germany, and the UK has resulted in the construction of the 25 MWe IEA-Grimethorpe combined-cycle pilot plant in England which will be tested in 1981. A 13 MWe coal-fired gas turbine (air cycle) at Curtis-Wright has been designed and construction scheduled. Start-up is planned to begin in early 1983. A 75 MWe pilot plant is planned for completion in 1986. Each of these PFBC combined-cycle programs is discussed. The current status of PFB technology may be summarized as follows: turbine erosion tolerance/hot gas cleanup issues have emerged as the barrier technology issues; promising turbine corrosion-resistant materials have been identified, but long-term exposure data is lacking; first-generation PFB combustor technology development is maturing at the PDU level; however, scale-up to larger size has not been demonstrated; and in-bed heat exchanger materials have been identified, but long-term exposure data is lacking. The DOE-PFB development plan is directed at the resolution of these key technical issues. (LCL)

Not Available

1980-10-01T23:59:59.000Z

159

Time-dependent response of a charcoal bed to radon and water vapor in flowing air  

SciTech Connect

Extremely high airborne concentrations of radon gas may be encountered during the remediation of uranium mill tailings storage facilities. Radon is also a constituent of the off-gas of mill-tailing vitrification. An effective way to remove radon from either gas is to pass the gas through a packed bed containing activated charcoal. Measurements of radon concentrations in the environment using charcoal canisters were first described by George. Canisters similar to those used by George in his first experiments have become the U.S. Environmental Protection Agency`s (EPA`s) standard for measuring environmental radon and were described in the EPA protocol for environmental radon measurement. The dynamic behavior of EPA charcoal canisters has been previously described with a mathematical model for the kinetics of radon gas adsorption in air in the presence of water vapor. This model for charcoal canisters has been extended to large charcoal beds with flowing air containing radon and water vapor. The mathematical model for large charcoal beds can be used to evaluate proposed bed designs or to model existing beds. Parameters that affect the radon distribution within a charcoal bed that can be studied using the mathematical model include carrier gas relative humidity and flow velocity, and input radon concentration. In addition, the relative performances of several different charcoals can be studied, provided sufficient information about their adsorption, desorption, and diffusion constants is known.

Henkel, J.A.; Fentiman, A.W.; Blue, T.E. [Ohio State Univ., Columbus, OH (United States)

1995-12-31T23:59:59.000Z

160

CERTS Microgrid Laboratory Test Bed  

Science Conference Proceedings (OSTI)

The objective of the CERTS Microgrid Test Bed project was to enhance the ease of integrating energy sources into a microgrid. The project accomplished this objective by developing and demonstrating three advanced techniques, collectively referred to as the CERTS Microgrid concept, that significantly reduce the level of custom field engineering needed to operate microgrids consisting of generating sources less than 100kW. The techniques comprising the CERTS Microgrid concept are: 1) a method for effecting automatic and seamless transitions between grid-connected and islanded modes of operation, islanding the microgrid's load from a disturbance, thereby maintaining a higher level of service, without impacting the integrity of the utility's electrical power grid; 2) an approach to electrical protection within a limited source microgrid that does not depend on high fault currents; and 3) a method for microgrid control that achieves voltage and frequency stability under islanded conditions without requiring high-speed communications between sources. These techniques were demonstrated at a full-scale test bed built near Columbus, Ohio and operated by American Electric Power. The testing fully confirmed earlier research that had been conducted initially through analytical simulations, then through laboratory emulations,and finally through factory acceptance testing of individual microgrid components. The islanding and resychronization method met all Institute of Electrical and Electronics Engineers Standard 1547 and power quality requirements. The electrical protection system was able to distinguish between normal and faulted operation. The controls were found to be robust under all conditions, including difficult motor starts and high impedance faults. The results from these tests are expected to lead to additional testing of enhancements to the basic techniques at the test bed to improve the business case for microgrid technologies, as well to field demonstrations involving microgrids that involve one or more of the CERTS Microgrid concepts. Future planned microgrid work involves unattended continuous operation of the microgrid for 30 to 60 days to determine how utility faults impact the operation of the microgrid and to gage the power quality and reliability improvements offered by microgrids.

Eto, Joe; Lasseter, Robert; Schenkman, Ben; Stevens, John; Klapp, Dave; Volkommer, Harry; Linton, Ed; Hurtado, Hector; Roy, Jean

2009-06-18T23:59:59.000Z

Note: This page contains sample records for the topic "bed consequence modeling" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
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161

DOD ESTCP Energy Test Bed Project | Department of Energy  

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

DOD ESTCP Energy Test Bed Project DOD ESTCP Energy Test Bed Project Presentation covers the DOD ESTCP Energy Test Bed Project, given at the May, 23 2012 Federal Technology...

162

Geomechanical risks in coal bed carbon dioxide sequestration  

E-Print Network (OSTI)

its geomechanical impact. A coal bed methane production/CO 2should be applicable to coal bed methane CO 2 projects. Ifcompletion for a coal bed methane project involves

Myer, Larry R.

2003-01-01T23:59:59.000Z

163

An in-bed tube bank for a fluidized-bed combustor  

DOE Patents (OSTI)

Fluidized-bed combustors have long been used to facilitate the combustion of low-quality fuels and more recently as a means for the clean burning of coal. In a fluidized-bed combustor fuel is fed into a bed of reactive or inert particulate material while air is injected into the bed and passed up through the bed, causing the bed material to act like a turbulent fluid. Where the combustor is utilized for steam generating one or more boiler tubes are positioned so as to span the bed while submerged in the bed, and as fuel is burned within the bed water is injected into the boiler tubes and heated, thereby generating steam. An in-bed tube bank is described for a fluidized bed combustor. The tube bank of the present invention comprises one or more fluid communicating boiler tubes which define a plurality of selectively spaced boiler tube sections. The tube sections are substantially parallel to one another and aligned in a common plane. The tube bank further comprises support members for joining adjacent tube sections, the support members engaging and extending along a selected length of the tube sections and spanning the preselected space there between 4 figs.

Hemenway, L.F. Jr.

1989-08-08T23:59:59.000Z

164

Magninos: Experimental consequences and constraints  

SciTech Connect

A stable weakly interacting massive particle can simultaneously solve both the solar neutrino and missing mass problems. We have identified this particle with a neutral lepton with mass of order 5 to 15 GeV and an anomalous magnetic moment of order 10/sup -2/ (in the natural units). We call this new particle a (magnino). In one scenario, the magnino is the neutral component of an electroweak doublet. It has a charged partner with mass a few GeV heavier. In this talk the experimental consequences of the magnino, its charged partner and associated Higgs are discussed. 25 refs., 9 figs.

Raby, S.; West, G.B.

1987-01-01T23:59:59.000Z

165

CERTS Microgrid Laboratory Test Bed  

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

Submitted to IEEE Transactions on Power Delivery Submitted to IEEE Transactions on Power Delivery Abstract--. CERTS Microgrid concept captures the emerging potential of distributed generation using a system approach. CERTS views generation and associated loads as a subsystem or a "microgrid". The sources can operate in parallel to the grid or can operate in island, providing UPS services. The system can disconnect from the utility during large events (i.e. faults, voltage collapses), but may also intentionally disconnect when the quality of power from the grid falls below certain standards. CERTS Microgrid concepts were demonstrated at a full-scale test bed built near Columbus, Ohio and operated by American Electric Power. The testing fully confirmed earlier research that had been conducted initially through analytical simulations,

166

Fluid bed adsorption of carbon dioxide on immobilized polyethyenimine (PEI): kinetic analysis and breakthrough behavior  

Science Conference Proceedings (OSTI)

The adsorption of carbon dioxide (CO{sub 2}) by immobilized polyethylenimine (PEI) on mesoporous silica was investigated in a fluid bed. The tests were performed to determine breakthrough behavior with varying bed temperature, flow rates and feed concentrations. Experimental breakthrough curves were analyzed using a theoretical 1D model developed by Bohart and Adams. The results showed that Bohart-Adams model was suitable for the normal description of breakthrough curve for the temperature ranges of 40-90{degree}C. The maximum capacity increased with temperature up to 70{degree}C and then decreased. The adsorption rate constant exhibited a negative temperature dependence decreasing as the temperature increased. Parameters characteristic of a fluid bed adsorber were inferred from these breakthrough curves including the breakthrough time, saturation time, critical reactor length, and length of mass transfer zone LMTZ. These parameters can be used to design fluid bed adsorption system without resolving the mechanistic contributions of dispersion, mixing, and intraparticle diffusion.

Monazam, Esmail R.; Spenik,, James; Shadle, Lawrence J.

2013-01-01T23:59:59.000Z

167

Numerical Simulation of Gas/Solid Flow in a Novel Annular Spouted Bed with Multiple Gas Nozzles  

Science Conference Proceedings (OSTI)

A novel annular spouted bed with multiple gas nozzles, has been proposed for dryness, pyrolysis, and gasification of coal particulates. It consists of two homocentric upright cylinders with some annularly located spouting gas nozzles between inner and ... Keywords: gas/solid flow, CFD, Eulerian multiphase model, kinetic theory of granular flow, annular spouted bed

Gong Xi-wu; Hu Guo-xin; Zhou Hai-jiang; Shi Qian

2009-10-01T23:59:59.000Z

168

Geomechanical risks in coal bed carbon dioxide sequestration  

E-Print Network (OSTI)

SAF. 1958. The strength of coal in triaxial compression.Geomechanical Risks in Coal Bed Carbon Dioxide Sequestrationof leakage of CO 2 from coal bed sequestration projects. The

Myer, Larry R.

2003-01-01T23:59:59.000Z

169

Changes related to "Coal Bed Methane Protection Act (Montana...  

Open Energy Info (EERE)

Special page Share this page on Facebook icon Twitter icon Changes related to "Coal Bed Methane Protection Act (Montana)" Coal Bed Methane Protection Act (Montana)...

170

Pages that link to "Coal Bed Methane Protection Act (Montana...  

Open Energy Info (EERE)

Edit History Share this page on Facebook icon Twitter icon Pages that link to "Coal Bed Methane Protection Act (Montana)" Coal Bed Methane Protection Act (Montana)...

171

Gas Turbines for Advanced Pressurized Fluidized Bed Combustion...  

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

APFBC uses a circulating pressurized fluidized bed combustor (PFBC) with a fluid bed heat exchanger to develop hot vitiated air for the gas turbine' s topping combustor and...

172

National SCADA Test Bed Enhancing control systems security in...  

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

SCADA Test Bed Enhancing control systems security in the energy sector National SCADA Test Bed Enhancing control systems security in the energy sector Improving the security of...

173

Probabilistic Accident Consequence Uncertainty - A Joint CEC/USNRC Study  

Science Conference Proceedings (OSTI)

The joint USNRC/CEC consequence uncertainty study was chartered after the development of two new probabilistic accident consequence codes, MACCS in the U.S. and COSYMA in Europe. Both the USNRC and CEC had a vested interest in expanding the knowledge base of the uncertainty associated with consequence modeling, and teamed up to co-sponsor a consequence uncertainty study. The information acquired from the study was expected to provide understanding of the strengths and weaknesses of current models as well as a basis for direction of future research. This paper looks at the elicitation process implemented in the joint study and discusses some of the uncertainty distributions provided by eight panels of experts from the U.S. and Europe that were convened to provide responses to the elicitation. The phenomenological areas addressed by the expert panels include atmospheric dispersion and deposition, deposited material and external doses, food chain, early health effects, late health effects and internal dosimetry.

Gregory, Julie J.; Harper, Frederick T.

1999-07-28T23:59:59.000Z

174

Dynamic behavior and control requirements of an atmospheric fluidized-bed coal combustion power plant: A conceptual study  

Science Conference Proceedings (OSTI)

A first-principles model of a nominal 20-MW atmospheric-pressure fluidized-bed coal combustion (AFBC) power plant was developed to provide insight into fundamental dynamic behavior of fluidized-bed systems. The control system included major loops for firing rate, steam pressure and temperature, forced and induced draft air flow, SO/sub 2/ emission, drum water level, evaporator recirculation, and bed level. The model was used to investigate system sensitivity to design features such as the distribution of heat transfer surface among the bed boiler and superheater and the out-of-bed superheater. Also calculated were the sensitivities of temperatures, pressures, and flow rates to changes in throttle, attemperator, and feedwater valve settings and forced and induced draft damper settings. The large bed mass, accounting for approx.40% of the active heat capacity, may vary under load change and could impact controller tuning. Model analysis indicated, however, that for the design studied, the change in bed mass does not appear to significantly affect controller tuning even if the bed mass varies appreciably under load-following conditions. Several bed designs are being considered for AFBC plants, some with partitions between bed sections and some without, and these differences may significantly affect the load-following capability of the plant. The results indicated that the slumping mode of operation can cause distortion of the heat source/sink distribution in the bed such that the load-following capability (rate of load change) of the plant may be reduced by as much as a factor of 5 compared with the mode in which tube surface is exposed. 9 refs., 13 figs., 6 tabs.

Smith, O.L.

1987-06-01T23:59:59.000Z

175

State of Fluidized Bed Combustion Technology  

E-Print Network (OSTI)

A new combustion technology has been developed in the last decade that permits the burning of low quality coal, lignite and other fuels, while maintaining stack emissions within State and Federal EPA limits. Low quality fuels can be burned directly in fluidized beds while taking advantage of low furnace temperatures and chemical activity within the bed to limit SO2 and NOx emissions, thereby eliminating the need for stack gas scrubbing equipment. The excellent heat transfer characteristics of the fluidized beds also result in a reduction of total heat transfer surface requirements, thus reducing the size and cost of steam generators. Tests on beds operating at pressures of one to ten atmospheres, at temperatures as high as 1600oF, and with gas velocities in the vicinity of four to twelve feet per second, have proven the concept. Early history of this technology is traced, and the progress that has been made in the development of fluidized bed combustion boilers, as well as work currently underway, in the United States and overseas, is reviewed. Details on the fluidized bed boiler installations at Alexandria, Virginia (5,000 lbs/hr), Georgetown University (100,000 lbs/hr), and Rivesville, West Virginia (300,000 Ibs/hr) are presented, and test results are discussed. Potential application of fluidized bed boilers in industrial plants using lignite and lignite refuse is examined. The impact of proposed new DOE and EPA regulations on solid fuels burning is also examined.

Pope, M.

1979-01-01T23:59:59.000Z

176

A Preliminary Study of the Effect of Shifts in Packing Fraction on k-effective in Pebble-Bed Reactors  

Science Conference Proceedings (OSTI)

A preliminary examination of the effect of pebble packing changes on the reactivity of a pebble-bed reactor (PBR) is performed. As a first step, using the MCNP code, the modeling of a PBR core as a continuous and homogenous region is compared to the modeling as a collection of discrete pebbles of equal average fuel density. It is shown that the two modeling approaches give the same trends inasmuch as changes in keff are concerned. It is thus shown that for the purpose of identifying trends in keff changes, the use of a homogeneous model is sufficient. A homogenous model is then used to assess the effect of pebble packing arrangement changes on the reactivity of a PBR core. It is shown that the changes can be large enough to result in prompt criticality. It is shown that for uranium fueled PBRs, thermal feedback could have the potential to offset the increase in activity, whereas for plutonium fueled systems, thermal feedback may not be sufficient for totally offsetting the packing-increase reactivity insertion and could even exacerbate the initial response. It is thus shown that a full study, including reactor kinetics, thermal feedback, and the dynamics of energy deposition and removal is warranted to fully characterize the potential consequences of packing shifts.

Ougouag, Abderrafi Mohammed-El-Ami; Terry, William Knox

2001-09-01T23:59:59.000Z

177

Consequence Management | National Nuclear Security Administration  

National Nuclear Security Administration (NNSA)

Consequence Management | National Nuclear Security Administration Consequence Management | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog The National Nuclear Security Administration Consequence Management Home > About Us > Our Programs > Emergency Response > Responding to Emergencies > Consequence Management Consequence Management NNSA's Consequence Management operations involve the deployment of the

178

Fluidized bed catalytic coal gasification process  

DOE Patents (OSTI)

Coal or similar carbonaceous solids impregnated with gasification catalyst constituents (16) are oxidized by contact with a gas containing between 2 volume percent and 21 volume percent oxygen at a temperature between 50.degree. C. and 250.degree. C. in an oxidation zone (24) and the resultant oxidized, catalyst impregnated solids are then gasified in a fluidized bed gasification zone (44) at an elevated pressure. The oxidation of the catalyst impregnated solids under these conditions insures that the bed density in the fluidized bed gasification zone will be relatively high even though the solids are gasified at elevated pressure and temperature.

Euker, Jr., Charles A. (15163 Dianna La., Houston, TX 77062); Wesselhoft, Robert D. (120 Caldwell, Baytown, TX 77520); Dunkleman, John J. (3704 Autumn La., Baytown, TX 77520); Aquino, Dolores C. (15142 McConn, Webster, TX 77598); Gouker, Toby R. (5413 Rocksprings Dr., LaPorte, TX 77571)

1984-01-01T23:59:59.000Z

179

PEBBLE-BED NUCLEAR REACTOR SYSTEM PHYSICS AND FUEL UTILIZATION  

E-Print Network (OSTI)

The Generation IV Pebble Bed Modular Reactor (PMBR) design may be used for electricity production, co-generation applications (industrial heat, hydrogen production, desalination, etc.), and could potentially eliminate some high level nuclear wastes. Because of these advantages, as well as the ability to build cost-effective small-to-medium sized reactors, this design is currently being considered for construction in many countries, from Japan, where test reactors are being analyzed, to China. The use of TRISO-coated micro-particles as a fuel in these reactors leads to multi-heterogeneity physics features that must be properly treated and accounted for. Inherent interrelationships of neutron interactions, temperature effects, and structural effects, further challenge computational evaluations of High Temperature Reactors (HTRs). The developed models and computational techniques have to be validated in code-to-code and, most importantly, code-to-experiment benchmark studies. This report quantifies the relative accuracy of various multi-heterogeneity treatments in whole-core 3D models for parametric studies of Generation IV Pebble Bed Modular Reactors as well as provide preliminary results of the PBMR performance analysis. Data is gathered from two different models, one based upon a benchmark for the African PBMR-400 design, and another based on the PROTEUS criticality experiment, since the African design is a more realistic power reactor, but the PROTEUS experiment model can be used for calculations that cannot be performed on the more complex model. Early data was used to refine final models, and the resulting final models were used to conduct parametric studies on composition and geometry optimization based on pebble bed reactor physics in order to improve fuel utilization.

Kelly, Ryan 1989-

2011-05-01T23:59:59.000Z

180

Heat transfer in freeboard region of fluidized beds  

SciTech Connect

This research involved the study of heat transfer and fluid mechanic characteristics around a horizontal tube in the freeboard region of fluidized beds. Heat transfer coefficients were experimetnally measured for different bed temperatures, particle sizes, gas flow rates, and tube elevations in the freeboard region of air fluidized beds at atmospheric pressure. Local heat transfer coefficients were found to vary significantly with angular position around the tube. Average heat transfer coefficients were found to decrease with increasing freeboard tube elevation and approach the values for gas convection plus radiation for any given gas velocity. For a fixed tube elevation, heat transfer coefficients generally increased with increasing gas velocity and with high particle entrainment they can approach the magnitudes found for immersed tubes. Heat transfer coefficients were also found to increase with increasing bed temperature. It was concluded that this increase is partly due to increase of radiative heat transfer and partly due to change of thermal properties of the fluidizing gas and particles. To investigate the fluid mechanic behavior of gas and particles around a freeboard tube, transient particle tube contacts were measured with a special capacitance probe in room temperature experiments. The results indicated that the tube surface experiences alternating dense and lean phase contacts. Quantitative information for local characteristics was obtained from the capacitance signals and used to develop a phenomenological model for prediction of the heat transfer coefficients around freeboard tubes. The packet renewal theory was modified to account for the dense phase heat transfer and a new model was suggested for the lean phase heat transfer. Finally, an empirical freeboard heat transfer correlation was developed from functional analysis of the freeboard heat transfer data using nondimensional groups representing gas velocity and tube elevation.

Biyikli, S.; Tuzla, K.; Chen, J.C.

1983-10-01T23:59:59.000Z

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181

Fluidized Bed Technology - Overview | Department of Energy  

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

Science & Innovation » Clean Coal » Advanced Combustion Science & Innovation » Clean Coal » Advanced Combustion Technologies » Fluidized Bed Technology - Overview Fluidized Bed Technology - Overview Fluidized beds suspend solid fuels on upward-blowing jets of air during the combustion process. The result is a turbulent mixing of gas and solids. The tumbling action, much like a bubbling fluid, provides more effective chemical reactions and heat transfer. Fluidized-bed combustion evolved from efforts to find a combustion process able to control pollutant emissions without external emission controls (such as scrubbers). The technology burns fuel at temperatures of 1,400 to 1,700 degrees F, well below the threshold where nitrogen oxides form (at approximately 2,500 degrees F, the nitrogen and oxygen atoms in the

182

Granular Dynamics in Pebble Bed Reactor Cores  

E-Print Network (OSTI)

flow in a pebble-bed nuclear reactor,” Phys. Rev. E, vol.from the current fleet of nuclear reactors far outweigh thethrough the core of a nuclear reactor. This regime includes

Laufer, Michael Robert

2013-01-01T23:59:59.000Z

183

NNSA Holds Radiation Emergency Consequence Management Training...  

National Nuclear Security Administration (NNSA)

Holds Radiation Emergency Consequence Management Training in Israel | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering...

184

Higher order discretization methods for the numerical simulation of fluidized beds  

SciTech Connect

Numerical models of fluidized beds based on the multiphase mass and momentum balance equations for gas and solids phases continue to be developed by several groups of researchers around the world. It has been demonstrated that the same set of equations is able to describe a wide range of fluidization conditions, ranging from bubbling to circulating fluidized beds. The results of bubbling bed simulations, plots of void fraction distribution, show the formation and propagation of high void fraction regions, called bubbles. This study shows that these problems are numerical artifacts of using first order accurate discretization schemes and coarse grids and are not due to a fundamental difficulty with the theory. This study was motivated by the observation that the shape of the gas hold up profile described by Sokolichin et al. is similar to that of the shape of bubbles in a fluidized bed. Second-order accurate discretization schemes were included in a multiphase flow model of fluidized beds called MFIX. It is shown here that the bubble shape predicted with a second order accurate scheme is rounded. The simulations were conducted for long durations (5 s) and the results did not show the fountain formation at the bed surface. It appears that the fountain formation is caused by coarse grids and low physical viscosity of the solids phase.

Syamlal, M.

1997-01-01T23:59:59.000Z

185

Neutronic analysis of pebble-bed cores with transuranics  

E-Print Network (OSTI)

At the brink of nuclear waste repository crises, viable alternatives for the long term radiotoxic wastes are seriously being considered worldwide. Minor actinides serve as one of these targeted wastes. Partitioning and transmutation in fission reactors is one possible incineration option and could potentially serve as a source of nuclear fuel required for sustainability of energy resources. The objective of this research was to evaluate the neutronic performance of the pebble-bed Very High Temperature Reactor (VHTR) configurations with various fuel loadings. The configuration adjustments and design sensitivity studies specifically targeted the achievability of spectral variations. The development of several realistic full-core 3D models and validation of all modeling techniques used was a major part of this research effort. In addition, investigating design sensitivities helped identify the parameters of primary interest. The full-core 3D models representing the prototype and large scale cores were created for use with SCALE 5.0 and SCALE 5.1 code systems. Initially the models required the external calculation of a Dancoff correction factor; however, the recent release of SCALE 5.1 encompassed inherent double heterogeneity modeling capabilities. The full core 3D models with multi-heterogeneity treatments are in agreement with available pebble-bed High Temperature Test Reactor data and were validated through benchmark studies. Analyses of configurations with various fuel loadings have indicated promising performance and safety characteristics. It was found that through small configuration adjustments, the pebble-bed design can be tweaked to produce desirable spectral shifts. The future operation of Generation IV nuclear energy systems would be greatly facilitated by the utilization of minor actinides as a fuel component. This would offer development of new fuel cycles, and support sustainability of a fuel source.

Pritchard, Megan Leigh

2007-12-01T23:59:59.000Z

186

Distribution of bed material in a Horizontal Circulating Fluidised Bed boiler.  

E-Print Network (OSTI)

??A conventional circulating fluidised bed (CFB) boiler has a limitation due to the height of the furnace, when implemented in smaller industrial facilities. The design… (more)

Ekvall, Thomas

2011-01-01T23:59:59.000Z

187

Fluidized bed injection assembly for coal gasification  

DOE Patents (OSTI)

A coaxial feed system for fluidized bed coal gasification processes including an inner tube for injecting particulate combustibles into a transport gas, an inner annulus about the inner tube for injecting an oxidizing gas, and an outer annulus about the inner annulus for transporting a fluidizing and cooling gas. The combustibles and oxidizing gas are discharged vertically upward directly into the combustion jet, and the fluidizing and cooling gas is discharged in a downward radial direction into the bed below the combustion jet.

Cherish, Peter (Bethel Park, PA); Salvador, Louis A. (Hempfield Township, Westmoreland County, PA)

1981-01-01T23:59:59.000Z

188

Anticipating the unintended consequences of security dynamics.  

SciTech Connect

In a globalized world, dramatic changes within any one nation causes ripple or even tsunamic effects within neighbor nations and nations geographically far removed. Multinational interventions to prevent or mitigate detrimental changes can easily cause secondary unintended consequences more detrimental and enduring than the feared change instigating the intervention. This LDRD research developed the foundations for a flexible geopolitical and socioeconomic simulation capability that focuses on the dynamic national security implications of natural and man-made trauma for a nation-state and the states linked to it through trade or treaty. The model developed contains a database for simulating all 229 recognized nation-states and sovereignties with the detail of 30 economic sectors including consumers and natural resources. The model explicitly simulates the interactions among the countries and their governments. Decisions among governments and populations is based on expectation formation. In the simulation model, failed expectations are used as a key metric for tension across states, among ethnic groups, and between population factions. This document provides the foundational documentation for the model.

Backus, George A.; Overfelt, James Robert; Malczynski, Leonard A.; Saltiel, David H.; Simon Paul Moulton

2010-01-01T23:59:59.000Z

189

Single-stage fluidized-bed gasification of peat  

Science Conference Proceedings (OSTI)

A single-stage fluidized-bed process to gasify peat for the production of a medium-Btu gas has a simple reactor design, maximizes product-gas yield by lowering oil production, and offers an economical means of using small peat deposits. In modeling this process, engineers applied process-development-unit data to derive a rate expression for fixed-carbon conversion and the influence of operating conditions on conversion. The rate of fixed carbon conversion is represented by a single path with the reactivity factor defined as a linear function of the moisture content. The model accurately describes the solids residence time and product yields for the reactor.

Rue, D.M.; Lau, F.S.; Weil, S.A.; Punwani, D.V.

1982-01-01T23:59:59.000Z

190

Fluid-bed-augmented CAES systems  

DOE Green Energy (OSTI)

Compressed Air Energy Storage (CAES) systems are potentially attractive for future electric utility load leveling applications. A potential long-term weakness of the conventional CAES concept is its reliance on clean petroleum fuels during the power generation period. This consumption of petroleum could be completely eliminated by the use of coal-fired fluid bed combustors in second generation CAES plants. A large number of CAES power system configurations are possible using atmospheric fluid bed combustion (AFBC) and pressurized fluid bed combustion (PFBC). The fuel consumption rates for these systems are generally comparable to those for oil-fired CAES systems. The future prognosis for using PFBC in CAES systems looks good. Recent corrosion and erosion experiments in fluid bed systems suggest that gas turbines with acceptable lifetimes in fluid bed systems suggest that gas turbines with acceptable lifetimes are a distinct possibility. The commercial status of these systems depends on the outcome of extensive corrosion/erosion testing in static and rotating test rigs. CAES systems using AFBC may be an attractive alternative to using PFBC, although the materials problem would then be transferred from the turbine to the high temperature heat exchanger surface. A reasonable expectation for the date of commercialization of fluid bed augmented CAES system ranges from 10 to 15 years.

Giramonti, A. J.

1979-01-01T23:59:59.000Z

191

Deep Bed Iodine Sorbent Testing FY 2011 Report  

Science Conference Proceedings (OSTI)

Nuclear fission results in the production of fission products (FPs) and activation products that increasingly interfere with the fission process as their concentrations increase. Some of these fission and activation products tend to evolve in gaseous species during used nuclear fuel reprocessing. Analyses have shown that I129, due to its radioactivity, high potential mobility in the environment, and high longevity (half life of 15.7 million years), can require control efficiencies of up to 1,000x or higher to meet regulatory emission limits. Deep-bed iodine sorption testing has been done to evaluate the performance of solid sorbents for capturing iodine in off-gas streams from nuclear fuel reprocessing plants. The objectives of the FY 2011 deep bed iodine sorbent testing are: (1) Evaluate sorbents for iodine capture under various conditions of gas compositions and operating temperature (determine sorption efficiencies, capacities, and mass transfer zone depths); and (2) Generate data for dynamic iodine sorption modeling. Three tests performed this fiscal year on silver zeolite light phase (AgZ-LP) sorbent are reported here. Additional tests are still in progress and can be reported in a revision of this report or a future report. Testing was somewhat delayed and limited this year due to initial activities to address some questions of prior testing, and due to a period of maintenance for the on-line GC. Each test consisted of (a) flowing a synthetic blend of gases designed to be similar to an aqueous dissolver off-gas stream over the sorbent contained in three separate bed segments in series, (b) measuring each bed inlet and outlet gas concentrations of iodine and methyl iodide (the two surrogates of iodine gas species considered most representative of iodine species expected in dissolver off-gas), (c) operating for a long enough time to achieve breakthrough of the iodine species from at least one (preferably the first two) bed segments, and (d) post-test purging with pure N2 to drive loosely or physisorbed iodine species off of the sorbent. Post-test calculations determine the control efficiencies for each bed, iodine loadings on the sorbent, and mass transfer zone depths. Portions of the iodine-laden sorbent from the first bed of two of the tests have been shipped to SNL for waste form studies. Over the past three years, we have explored a full range of inlet iodine and methyl iodide concentrations ranging from {approx}100 ppb to {approx}100 ppm levels, and shown adequate control efficiencies within a bed depth as shallow as 2 inches for lower concentrations and 4 inches for higher concentrations, for the AgZ-type sorbents. We are now performing a limited number of tests in the NC-77 sorbent from SNL. Then we plan to continue to (a) fill in data gaps needed for isotherms and dynamic sorbent modeling, and (b) test the performance of additional sorbents under development.

Nick Soelberg; Tony Watson

2011-08-01T23:59:59.000Z

192

Enhanced Productivity of Chemical Processes Using Dense Fluidized Beds  

Science Conference Proceedings (OSTI)

The work detailed in this report addresses Enabling Technologies within Computational Technology by integrating a “breakthrough” particle-fluid computational technology into traditional Process Science and Engineering Technology. The work completed under this DOE project addresses five major development areas 1) gas chemistry in dense fluidized beds 2) thermal cracking of liquid film on solids producing gas products 3) liquid injection in a fluidized bed with particle-to-particle liquid film transport 4) solid-gas chemistry and 5) first level validation of models. Because of the nature of the research using tightly coupled solids and fluid phases with a Lagrangian description of the solids and continuum description of fluid, the work provides ground-breaking advances in reactor prediction capability. This capability has been tested against experimental data where available. The commercial product arising out of this work is called Barracuda and is suitable for a wide (dense-to-dilute) range of industrial scale gas-solid flows with and without reactions. Commercial applications include dense gas-solid beds, gasifiers, riser reactors and cyclones.

Sibashis Banerjee; Alvin Chen; Rutton Patel; Dale Snider; Ken Williams; Timothy O'Hern; Paul Tortora

2008-02-29T23:59:59.000Z

193

CERTS Microgrid Laboratory Test Bed  

E-Print Network (OSTI)

emerging potential of distributed generation using a systemKeywords: CHP, UPS, distributed generation, intentionalmanagement systems, distributed generation, and modeling

Lasseter, R. H.

2010-01-01T23:59:59.000Z

194

Coal fired fluid bed module for a single elevation style fluid bed power plant  

DOE Patents (OSTI)

A fluidized bed for the burning of pulverized fuel having a specific waterwall arrangement that comprises a structurally reinforced framework of wall tubes. The wall tubes are reversely bent from opposite sides and then bonded together to form tie rods that extend across the bed to support the lateral walls thereof.

Waryasz, Richard E. (Chicopee, MA)

1979-01-01T23:59:59.000Z

195

Ash bed level control system for a fixed-bed coal gasifier  

DOE Patents (OSTI)

An ash level control system is provided which incorporates an ash level meter to automatically control the ash bed level of a coal gasifier at a selected level. The ash level signal from the ash level meter is updated during each cycle that a bed stirrer travels up and down through the extent of the ash bed level. The ash level signal is derived from temperature measurements made by thermocouples carried by the stirrer as it passes through the ash bed and into the fire zone immediately above the ash bed. The level signal is compared with selected threshold level signal to determine if the ash level is above or below the selected level once each stirrer cycle. A first counter is either incremented or decremented accordingly. The registered count of the first counter is preset in a down counter once each cycle and the preset count is counted down at a selected clock rate. A grate drive is activated to rotate a grate assembly supporting the ash bed for a period equal to the count down period to maintain the selected ash bed level. In order to avoid grate binding, the controller provides a short base operating duration time each stirrer cycle. If the ash bed level drops below a selected low level or exceeds a selected high level, means are provided to notify the operator.

Fasching, George E. (Morgantown, WV); Rotunda, John R. (Fairmont, WV)

1984-01-01T23:59:59.000Z

196

2012 SG Peer Review - LANL Smart Grid Technology Test Bed - Scott Backhaus, LANL  

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

Technology Test Bed Technology Test Bed Scott Backhaus Los Alamos National Laboratory June 8, 2012 December 2008 Smart Grid Technology Test Bed Objectives Life-cycle Funding ($K) Technical Scope - Create and demonstrate a replicable DER control system-focus on small electrical utilities and co-operatives - Integration of renewables - Planning of DER portfolios - Assess economic DER value - Development/characterization of DER - Commercial HVAC - Run-of-river hydro  Model predictive control (MPC) of diverse portfolios of distributed resources  Optimal/controllable modification of the statistics of PV variability  Data-driven models for control of HVAC in large commercial buildings  Models/control of run-of-river hydro-river impacts 2 FY10-11 FY12 FY13 Request FY14 Request 350 300 400 400

197

Metal wastage design guidelines for bubbling fluidized-bed combustors. Final report  

Science Conference Proceedings (OSTI)

These metal wastage design guidelines identify relationships between metal wastage and (1) design parameters (such as tube size, tube spacing and pitch, tube bundle and fluidized-bed height to distributor, and heat exchanger tube material properties) and (2) operating parameters (such as fluidizing velocity, particle size, particle hardness, and angularity). The guidelines are of both a quantitative and qualitative nature. Simplified mechanistic models are described, which account for the essential hydrodynamics and metal wastage processes occurring in bubbling fluidized beds. The empirical correlational approach complements the use of these models in the development of these design guidelines. Data used for model and guideline validation are summarized and referenced. Sample calculations and recommended design procedures are included. The influences of dependent variables on metal wastage, such as solids velocity, bubble size, and in-bed pressure fluctuations, are discussed.

Lyczkowski, R.W.; Podolski, W.F.; Bouillard, J.X.; Folga, S.M. [Argonne National Lab., IL (United States)

1992-11-01T23:59:59.000Z

198

State of Industrial Fluidized Bed Combustion  

E-Print Network (OSTI)

A new combustion technique has been developed in the last decade that permits the burning of low quality coal, lignite and other fuels, while maintaining stack emissions within State and Federal limits. Low quality fuels can be burned directly in fluidized beds while taking advantage of low furnace temperatures am chemical activity within the bed to limit S02 am NOx emissions, thereby eliminating the need for stack gas scrubbing equipment. The excellent heat transfer characteristics of the fluidized beds also result in a reduction of total heat transfer surface requirements, thus reducing the size and cost of steam generators. Recent tests on commercial units have proven the concept. This paper reviews the progress that has been trade in the development of fluidized bed combustion boilers, as well as work currently under way in the United States and overseas. Details on the installation at Georgetown University in Washington, D.C., am at other locations are presented, am operational results are discussed. Potential application of fluidized bed boilers in industrial plants using lignite and lignite refuse is also examined.

Mesko, J. E.

1982-01-01T23:59:59.000Z

199

Moving Granular Bed Filter Development Program  

SciTech Connect

The granular bed filter was developed through low pressure, high temperature (1600{degrees}F) testing in the late 1970`s and early 1980`s`. Collection efficiencies over 99% were obtained. In 1988, high pressure, high temperature testing was completed at New York University, Westbury, N.Y., utilizing a coal-fired pressurized, fluidized bed combustor. High particulate removal efficiencies were confirmed as it was shown that both New Source Performance Standards and turbine tolerance limits could be met. The early scale-up work of the granular bed filter indicated potential limitations due to size, cost, and mechanical complexity. These limitations were addressed in the present program by utilizing the information gained from the filter development up through the NYU test program to reassess the commercial approach. Two studies were chosen for developing conceptual designs and cost estimates of the commercial sized filters. One is the economic study of the 250 MWe, second generation pressurized fluidized bed combustion plant defined by Foster Wheeler. This plant originally included cross-flow filters for hot gas cleanup. The other plant under study is a 100 MWe, airblown KRW gasifier. A cross-flow inter was utilized for gas stream cleanup in this study also. Granular bed and ceramic candle filters were substituted for the cross-flow filters in both these plants, and the resulting cost of electricity (COE) is compared.

Wilson, K.B.; Haas, J.C.; Eshelman, M.B.

1992-11-01T23:59:59.000Z

200

Moving Granular Bed Filter Development Program  

SciTech Connect

The granular bed filter was developed through low pressure, high temperature (1600[degrees]F) testing in the late 1970's and early 1980's'. Collection efficiencies over 99% were obtained. In 1988, high pressure, high temperature testing was completed at New York University, Westbury, N.Y., utilizing a coal-fired pressurized, fluidized bed combustor. High particulate removal efficiencies were confirmed as it was shown that both New Source Performance Standards and turbine tolerance limits could be met. The early scale-up work of the granular bed filter indicated potential limitations due to size, cost, and mechanical complexity. These limitations were addressed in the present program by utilizing the information gained from the filter development up through the NYU test program to reassess the commercial approach. Two studies were chosen for developing conceptual designs and cost estimates of the commercial sized filters. One is the economic study of the 250 MWe, second generation pressurized fluidized bed combustion plant defined by Foster Wheeler. This plant originally included cross-flow filters for hot gas cleanup. The other plant under study is a 100 MWe, airblown KRW gasifier. A cross-flow inter was utilized for gas stream cleanup in this study also. Granular bed and ceramic candle filters were substituted for the cross-flow filters in both these plants, and the resulting cost of electricity (COE) is compared.

Wilson, K.B.; Haas, J.C.; Eshelman, M.B.

1992-01-01T23:59:59.000Z

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


201

National SCADA Test Bed | Department of Energy  

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

Cybersecurity » Energy Delivery Systems Cybersecurity Cybersecurity » Energy Delivery Systems Cybersecurity » National SCADA Test Bed National SCADA Test Bed Created in 2003, the National SCADA Test Bed (NSTB) is a one-of-a-kind national resource that draws on the integrated expertise and capabilities of the Argonne, Idaho, Lawrence Berkeley, Los Alamos, Oak Ridge, Pacific Northwest, and Sandia National Laboratories to address the cybersecurity challenges of energy delivery systems. Core and Frontier Research The NSTB core capabilities combine a network of the national labs' state-of-the-art operational system testing facilities with expert research, development, analysis, and training to discover and address critical security vulnerabilities and threats the energy sector faces. NSTB offers testing and research facilities, encompassing field-scale control

202

Rock bed heat accumulators. Final report  

DOE Green Energy (OSTI)

The principal objectives of the research program on rock bed heat accumulators (or RBHA) are: (1) to investigate the technical and economic feasibility of storing large amounts of thermal energy (in the tens of MWt range) at high temperature (up to 500/sup 0/C) over extended periods of time (up to 6 months) using native earth or rock materials; (2) to conduct studies to establish the performance characteristics of large rock bed heat accumulators at various power and temperature levels compatible with thermal conversion systems; and (3) to assess the materials and environmental problems associated with the operation of such large heat accumulators. Results of the study indicate that rock bed heat accumulators for seasonal storage are both technically and economically feasible, and hence could be exploited in various applications in which storage plays an essential role such as solar power and total energy systems, district and cogeneration heating systems.

Riaz, M.

1977-12-01T23:59:59.000Z

203

Fluidized bed selective pyrolysis of coal  

DOE Patents (OSTI)

The present invention discloses a process for the pyrolysis of coal which comprises the effective utilization of two zonal inclined fluidized beds, where said zones can be selectively controlled as to temperature and heating rate. The first zonal inclined fluidized bed serves as a dryer for crushed coal and additionally is controlled to selectively pyrolyze said coal producing substantially carbon dioxide for recycle use. The second zonal inclined fluidized bed further pyrolyses the coal to gaseous, liquid and char products under controlled temperature and heating rate zones designed to economically integrate the product mix. The gas and liquid products are recovered from the gaseous effluent stream while the char which remains can be further treated or utilized in a subsequent process step. 9 figs.

Shang, J.Y.; Cha, C.Y.; Merriam, N.W.

1992-12-15T23:59:59.000Z

204

Fluidized bed selective pyrolysis of coal  

SciTech Connect

The present invention discloses a process for the pyrolysis of coal which comprises the effective utilization of two zonal inclined fluidized beds, where said zones can be selectively controlled as to temperature and heating rate. The first zonal inclined fluidized bed serves as a dryer for crushed coal and additionally is controlled to selectively pyrolyze said coal producing substantially carbon dioxide for recycle use. The second zonal inclined fluidized bed further pyrolyzes the coal to gaseous, liquid and char products under controlled temperature and heating rate zones designed to economically integrate the product mix. The gas and liquid products are recovered from the gaseous effluent stream while the char which remains can be further treated or utilized in a subsequent process step.

Shang, Jer Y. (McLean, VA); Cha, Chang Y. (Golden, CO); Merriam, Norman W. (Laramie, WY)

1992-01-01T23:59:59.000Z

205

Particle withdrawal from fluidized bed systems  

DOE Patents (OSTI)

Method and apparatus for removing ash formed within, and accumulated at the lower portion of, a fluidized bed coal gasification reactor vessel. A supplemental fluidizing gas, at a temperature substantially less than the average fluidized bed combustion operating temperature, is injected into the vessel and upwardly through the ash so as to form a discrete thermal interface region between the fluidized bed and the ash. The elevation of the interface region, which rises with ash accumulation, is monitored by a thermocouple and interrelated with a motor controlled outlet valve. When the interface rises above the temperature indicator, the valve opens to allow removal of some of the ash, and the valve is closed, or positioned at a minimum setting, when the interface drops to an elevation below that of the thermocouple.

Salvador, Louis A. (Greensburg, PA); Andermann, Ronald E. (Arlington Heights, IL); Rath, Lawrence K. (Mt. Pleasant, PA)

1982-01-01T23:59:59.000Z

206

Novel Simulated moving bed technologies  

DOE Green Energy (OSTI)

Cellulose and hemicellulose from plants and other biomass can be hydrolyzed to produce sugars (i.e. glucose and xylose). Once these sugars are separated from other impurities, they can serve as feedstock in fermentation to produce ethanol (as fuels), lactic acid, or other valuable chemicals. The need for producing fuels and chemicals from renewable biomass has become abundantly clear over the last decade. However, the cost of producing fermentable sugars from biomass hydrolyzate using existing technology is relatively high and has been a major obstacle. The objective of this project is to develop an efficient and economical simulated moving bed (SMB) process to recover fermentable sugars from biomass hydrolyzate. Sulfuric acid can hydrolyze the cellulose and hemicellulose in biomass to sugars, but this process can generate byproducts such as acetic acid, and can lead to further degradation of the xylose to furfural and glucose to hydroxymethyl furfural (HMF). Also, lignin and other compounds in the biomass will degrade to various phenolic compounds. If the concentrations of these compounds exceed certain threshold levels, they will be toxic to the downstream fermentation, and will severely limit the usefulness of the derived sugars. Standard post-hydrolysis processing involves neutralization of sulfuric acid, usually with lime (calcium hydroxide). A study by Wooley et al.showed that the limed hydrolyzate gave a low ethanol yield in fermentation test (20% of theoretical yield compared to 77% of theoretical yield from fermentation of pure sugars). They showed that instead of adding lime, an ion exclusion chromatography process could be used to remove acids, as well as to isolate the sugars from the biomass hydrolyzate. In this project, we investigated the feasibility of developing an economical SMB process based on (1) a polymeric adsorbent, Dowex99, which was used by Wooley et al., (2) a second polymeric adsorbent, poly-4-vinyl pyridine (or PVP in short, Reilly Industries Inc., Indianapolis, IN), which has been used for organic acid separations, and (3) an activated carbon adsorbent. The adsorption isotherms and mass transfer parameters of the two polymeric adsorbents were estimated using single-component pulse tests and frontal tests. The parameters were then validated using batch elution chromatography test of a corn-stover hydrolyzate, which was provided gratis by NREL. The sugars recovered in batch chromatography were then fermented using yeast developed at Dr. Ho's LORRE laboratory. A standard mixture of pure sugars and an overlimed corn-stover hydrolyzate were fermented using the same procedure simultaneously. The fermentability of the overlimed hydrolyzate was the worst, and that of the sugars recovered using the PVP column was similar to that of the pure sugar mixture. The sugars recovered using the Dowex99 column had an intermediate fermentability. Since the sugars were the ''center cut'' in the Dowex99 column, a tandem SMB (two SMB's in series) design was needed to obtain sugars of high purity. By contrast, sugars were the fast-moving components in the PVP column, and only a single SMB was needed to recover sugars from the hydrolyzate. The impurities, such as sulfuric acid, acetic acid, HMF, and furfural, had higher affinities for PVP. Caustic regeneration was needed to efficiently remove these impurities from PVP. Therefore, a five-zone SMB, which includes a regeneration zone and a reequilibration zone, was developed. The isotherms and mass transfer parameters estimated from batch chromatography experiments were used in the design of SMB processes. A Standing Wave Design method was developed for the five-zone SMB and the tandem SMB. Cost analysis was carried out based on the resulting operating conditions. The analysis showed that the PVP five-zone SMB process was more economical than the Dowex99 tandem SMB process. The cost analysis also showed that elution and equipment costs are dominant for the Dowex99 SMB and the regeneration cost is dominant (60%) for the PVPSMB. Both the cost analysis and the fermentatio

Purdue University

2003-12-30T23:59:59.000Z

207

Solid fuel feed system for a fluidized bed  

SciTech Connect

A fluidized bed for the combustion of coal, with limestone, is replenished with crushed coal from a system discharging the coal laterally from a station below the surface level of the bed. A compartment, or feed box, is mounted at one side of the bed and its interior separated from the bed by a weir plate beneath which the coal flows laterally into the bed while bed material is received into the compartment above the plate to maintain a predetermined minimum level of material in the compartment.

Jones, Brian C. (Windsor, CT)

1982-01-01T23:59:59.000Z

208

Fluidized bed heat exchanger utilizing angularly extending heat exchange tubes  

DOE Patents (OSTI)

A fluidized bed heat exchanger in which air is passed through a bed of particulate material containing fuel disposed in a housing. A steam/water natural circulation system is provided and includes a steam drum disposed adjacent the fluidized bed and a series of tubes connected at one end to the steam drum. A portion of the tubes are connected to a water drum and in the path of the air and the gaseous products of combustion exiting from the bed. Another portion of the tubes pass through the bed and extend at an angle to the upper surface of the bed.

Talmud, Fred M. (Berkeley Heights, NJ); Garcia-Mallol, Juan-Antonio (Morristown, NJ)

1980-01-01T23:59:59.000Z

209

Internal dust recirculation system for a fluidized bed heat exchanger  

DOE Patents (OSTI)

A fluidized bed heat exchanger in which air is passed through a bed of particulate material containing fuel disposed in a housing. A steam/water natural circulation system is provided in a heat exchange relation to the bed and includes a steam drum disposed adjacent the bed and a tube bank extending between the steam drum and a water drum. The tube bank is located in the path of the effluent gases exiting from the bed and a baffle system is provided to separate the solid particulate matter from the effluent gases. The particulate matter is collected and injected back into the fluidized bed.

Gamble, Robert L. (Wayne, NJ); Garcia-Mallol, Juan A. (Morristown, NJ)

1981-01-01T23:59:59.000Z

210

3-D capacitance density imaging of fluidized bed  

DOE Patents (OSTI)

A three-dimensional capacitance density imaging of a gasified bed or the like in a containment vessel is achieved using a plurality of electrodes provided circumferentially about the bed in levels and along the bed in channels. The electrodes are individually and selectively excited electrically at each level to produce a plurality of current flux field patterns generated in the bed at each level. The current flux field patterns are suitably sensed and a density pattern of the bed at each level determined. By combining the determined density patterns at each level, a three-dimensional density image of the bed is achieved.

Fasching, George E. (653 Vista Pl., Morgantown, WV 26505)

1990-01-01T23:59:59.000Z

211

Real-Time Building Energy Simulation Using EnergyPlus and the Building Controls Test Bed  

E-Print Network (OSTI)

the Building Controls Virtual Test Bed. Proceedings of 12 thand the Building Controls Test Bed Xiufeng Pang, PrajeshBUILDING CONTROLS VIRTUAL TEST BED Xiufeng Pang 1 , Prajesh

Pang, Xiufeng

2013-01-01T23:59:59.000Z

212

Radiological consequence analysis with HEU and LEU fuels  

SciTech Connect

A model for estimating the radiological consequences from a hypothetical accident in HEU and LEU fueled research and test reactors is presented. Simple hand calculations based on fission product yield table inventories and non-site specific dispersion data may be adequate in many cases. However, more detailed inventories and site specific data on meteorological conditions and release rates and heights can result in substantial reductions in the dose estimates. LEU fuel gives essentially the same doses as HEU fuel. The plutonium buildup in the LEU fuel does not significantly increase the radiological consequences. The dose to the thyroid is the limiting dose. 10 references, 3 figures, 7 tables.

Woodruff, W.L.; Warinner, D.K.; Matos, J.E.

1984-01-01T23:59:59.000Z

213

Electrostatic granular bed filter development program. Final report  

SciTech Connect

The application of the electrostatically enhanced granular bed filter (EGB) in a pressurized fluidized bed (PFB) combined cycle power plant is explored in this study. In a PFB combustor power plant, dust particles entrained in the combustion gases must be removed at high temperature (1700/sup 0/F) and pressure (10 atm) in order to protect a gas turbine from erosion. The EFB filter provides a unique design adapted to avoid filter front face plugging which has been the limiting factor in the successful development of granular bed filters for this application. Under the present study, laboratory experiments and analyses were performed to provide the engineering data necessary to design a test module in the actual PFB environment. An analytical model for predicting the performance of an EGB was also developed. The test data and the model were then utilized to establish preferred geometries and operating parameters of the EGB filter system applied in a 663 MWe PFB power plant. Preliminary conceptual designs were established and an economic evaluations performed. The results of the system analysis and economic studies were analyzed to assess the applicability of the EGB filter to utility scale PFB power plants. New power plants must also meet New Source Performance Standards (.03 lb/10/sup 6/ Btu) which necessitates removal of dust in the respirable size range which would otherwise be harmless to the gas turbine. A key technical issue in the PFB application is whether the hot gas cleanup equipment can satisfy the NSPS. The potential of the EGB for achieving NSPS ahead of the gas turbine is demonstrated, and the conceptual design and economics of this application are presented. (LCL)

1981-11-01T23:59:59.000Z

214

Open-cycle absorption cooling using packed-bed absorbent reconcentration  

DOE Green Energy (OSTI)

The technical feasibility of a lithium chloride open-cycle absorption air conditioner using solar-heated air for reconcentration of the absorbent solution is examined. In contrast to a successfully operating Soviet design (in which absorbent reconcentration is accomplished by trickling the solution across a sloping black roof exposed to the sun), this study involves a packed-bed concentrator. Solar-heated air reconcentrates the solution by vaporizing water (the refrigerant) from the solution in the packed bed, enabling the system to be incorporated into a conventional solar air heating system and avoiding numerous problems associated with the roof concentrator. A thermodynamic analysis provides the criteria for the design of the packed bed. Heat and mass transfer processes occurring simultaneously in the bed are modeled using an iterative technique with the aid of a digital computer. The size of the packed-bed required to reconcentrate the absorbent solution at a rate corresponding to 10,550 W of cooling is determined, using flow rates, temperatures, and humidities typical of residential solar air-heating systems. Based on these results, the system air conditioning capability with solar energy input is predicted over the course of a clear summer day for Fort Collins, Colorado, and St. Louis, Missouri. Sufficient cooling capacity to meet a 10,550 W peak load using a 70 m/sup 2/ flatplate collector array is predicted by the model for both locations.

Leboeuf, C. M.; Loef, G. O.G.

1980-05-01T23:59:59.000Z

215

Consequence Management, Safeguards & Non-Proliferation Tools | ORNL  

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

Consequence Consequence Management, Safeguards, and Non-Proliferation Tools SHARE Consequence Management, Safeguards and Non-Proliferation Tools UF 6 Enrichment Facility Visualization of the gamma radiation field in a mock-up of a UF-6 enrichment facility. The solution was generated on a desktop computer using ORNL's Denovo SN transport code and ADVANTG interface, using geometry and material descriptions from an NRL SWORD input file. ORNL is a leader in developing state-of-the-art radiation transport modeling and simulation tools and in applying these tools to solve challenging problems in national and global nuclear security. Recent developments in high-performance, high-fidelity, deterministic Monte Carlo, and hybrid Monte Carlo/deterministic radiation transport codes within

216

Arrayed microfluidic actuation for active sorting of fluid bed particulates  

E-Print Network (OSTI)

Fluidic actuation offers a facile method to move large quantities of small solids, often referred to as fluid-bed movement. Applications for fluid bed processing are integral to many fields including petrochemical, petroleum, ...

Gerhardt, Antimony L

2004-01-01T23:59:59.000Z

217

Biogeochemistry of Microbial Coal-Bed Methane  

E-Print Network (OSTI)

Biogeochemistry of Microbial Coal-Bed Methane Dariusz Strapo´c,1, Maria Mastalerz,2 Katherine, biodegradation Abstract Microbial methane accumulations have been discovered in multiple coal- bearing basins low-maturity coals with predominantly microbial methane gas or uplifted coals containing older

Macalady, Jenn

218

Fluidized bed retorting of eastern oil shale  

SciTech Connect

This topical report summarizes the conceptual design of an integrated oil shale processing plant based on fluidized bed retorting of eastern New Albany oil shale. This is the fourth design study conducted by Foster Wheeler; previous design cases employed the following technologies: Fluidized bed rotating/combustion of Colorado Mahogany zone shale. An FCC concept of fluidized bed retorting/combustion of Colorado Mahogany zone shale. Directly heated moving vertical-bed process using Colorado Mahogany zone shale. The conceptual design encompasses a grassroots facility which processes run-of-mine oil shale into a syncrude oil product and dispose of the spent shale solids. The plant has a nominal capacity of 50,000 barrels per day of syncrude product, produced from oil shale feed having a Fischer Assay of 15 gallons per ton. Design of the processing units was based on non-confidential published information and supplemental data from process licensors. Maximum use of process and cost information developed in the previous Foster Wheeler studies was employed. The integrated plant design is described in terms of the individual process units and plant support systems. The estimated total plant investment is detailed by plant section and estimates of the annual operating requirements and costs are provided. In addition, process design assumptions and uncertainties are documented and recommendations for process alternatives, which could improve the overall plant economics, are discussed. 12 refs., 17 figs., 52 tabs.

Gaire, R.J.; Mazzella, G.

1989-03-01T23:59:59.000Z

219

Reversed flow fluidized-bed combustion apparatus  

DOE Patents (OSTI)

The present invention is directed to a fluidized-bed combustion apparatus provided with a U-shaped combustion zone. A cyclone is disposed in the combustion zone for recycling solid particulate material. The combustion zone configuration and the recycling feature provide relatively long residence times and low freeboard heights to maximize combustion of combustible material, reduce nitrogen oxides, and enhance sulfur oxide reduction.

Shang, Jer-Yu (Fairfax, VA); Mei, Joseph S. (Morgantown, WV); Wilson, John S. (Morgantown, WV)

1984-01-01T23:59:59.000Z

220

Modularity Approach Modular Pebble Bed Reactor (MPBR)  

E-Print Network (OSTI)

· On--line Refueling #12;4/23/03 MIT NED MPBR Reference Plant Modular Pebble Bed Reactor Thermal Power ­ Reduces Location Requirements #12;4/23/03 MIT NED MPBR · Plant "Farm": ~10 MPBR Systems per "Power Plant modularity principles to the design, construction and operation of advanced nuclear energy plants · To employ

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221

138 Chemical Engineering Education FLUIDIZED BED  

E-Print Network (OSTI)

gasification · Thermal cracking of naphtha petroleum fractions to produce ethylene and propylene · Fluid coking filled manometer. · Estimate the thickness of a polymer coating from know- ing the surface area and fluidized bed using a liquid filled manometer. Students also do some problem solving by estimating

Hesketh, Robert

222

Pebble Flow Experiments For Pebble Bed Reactors  

E-Print Network (OSTI)

Pebble Flow Experiments For Pebble Bed Reactors Andrew C. Kadak1 Department of Nuclear Engineering of Technology 2nd International Topical Meeting on High Temperature Reactor Technology Institute of Nuclear in such a reactor would conform to granular flow theory which suggested rapid mixing as opposed to linear flow lines

Bazant, Martin Z.

223

Circulating Fluid-Bed Technology for Advanced Power Systems  

Science Conference Proceedings (OSTI)

Circulating fluid bed technology offers the advantages of a plug flow, yet well-mixed, and high throughput reactor for power plant applications. The ability to effectively scale these systems in size, geometry, and operating conditions is limited because of the extensive deviation from ideal dilute gas-solids flow behavior (Monazam et al., 2001; Li, 1994). Two fluid computations show promise of accurately simulating the hydrodynamics in the riser circulating fluid bed; however, validation tests for large vessels with materials of interest to the power industry are lacking (Guenther et al., 2002). There is little available data in reactors large enough so that geometry (i.e. entrance, exit, and wall) effects do not dominate the hydrodynamics, yet with sufficiently large particle sizes to allow sufficiently large grid sizes to allow accurate and timely hydrodynamic simulations. To meet this need experimental tests were undertaken with relatively large particles of narrow size distribution in a large enough unit to reduce the contributions of wall effects and light enough to avoid geometry effects. While computational fluid dynamic calculations are capable of generating detailed velocity and density profiles, it is believed that the validation and model development begins with the ability to simulate the global flow regime transitions. The purpose of this research is to generate well-defined test data for model validation and to identify and measure critical parameters needed for these simulations.

Shadle, Lawrence J.; Ludlow, J. Christopher; Mei, Joseph S. (U.S. DOE National Energy Technology Laboratory); Guenther, Christopher (Fluent, Inc.)

2001-11-06T23:59:59.000Z

224

Bed material agglomeration during fluidized bed combustion. Technical progress report, January 1, 1993--March 31, 1993  

SciTech Connect

The purpose of this project is to determine the physical and chemical reactions which lead to the undesired agglomeration of bed material during fluidized bed combustion and to relate these reactions to specific causes. A survey of agglomeration and deposit formation in industrial fluidized bed boilers is in progress. Preliminary results indicate that at least five boilers were experiencing some form of bed material agglomeration. In these instances it was observed that large particles were forming within the bed which were larger that the feed. Four operators could confirm that the larger bed particles had formed due to bed particles sticking together or agglomerating. Deposit formation was reported at nine sites with these deposits being found most commonly at coal feed locations and in cyclones. Other deposit locations included side walls and return loops. Examples of these agglomerates and deposits have been received from five of the surveyed facilities. Also during this quarter, a bulk sample of Illinois No. 6 coal was obtained from the Fossil Energy Program at Ames Laboratory here at Iowa State University and prepared for combustion tests. This sample was first ground to a top-size of 3/8`` using a jaw crusher then a size fraction of 3/8`` {times} 8 (US mesh) was then obtained by sieving using a Gilson Test-Master. This size fraction was selected for the preliminary laboratory-scale experiments designed to simulate the dense bed conditions that exist in the bottom of CFB combustors. To ensure uniformity of fuel composition among combustion runs, the sized coal was riffled using, a cone and long row method and stored in bags for each experiment. During this quarter additional modifications were made to achieve better control of fluidization regimes and to aid in monitoring the hydrodynamic and chemical conditions within the reactor.

Brown, R.C.; Dawson, M.R.; Noble, S.D.

1993-04-01T23:59:59.000Z

225

Heat exchanger support apparatus in a fluidized bed  

DOE Patents (OSTI)

A heat exchanger is mounted in the upper portion of a fluidized combusting bed for the control of the temperature of the bed. A support, made up of tubes, is extended from the perforated plate of the fluidized bed up to the heat exchanger. The tubular support framework for the heat exchanger has liquid circulated therethrough to prevent deterioration of the support.

Lawton, Carl W. (West Hartford, CT)

1982-01-01T23:59:59.000Z

226

Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion system. Final technical report  

Science Conference Proceedings (OSTI)

Research is presented on erosion and corrosion of fluidized bed combustor component materials. The characteristics of erosion of in-bed tubes was investigated. Anti-corrosion measures were also evaluated.

Lee, Seong W.

1996-11-01T23:59:59.000Z

227

Political mobilization, venue change, and the coal bed methane conflict in Montana and Wyoming  

Science Conference Proceedings (OSTI)

The emerging conflict over coal bed methane (CBM) exploration and development in the mountain west offers a classic example of what Baumgartner and Jones call a 'wave of criticism.' The cozy subgovernments that have dominated energy exploration and development in the mountain states are now under attack and are struggling to maintain their autonomy. Energy exploration, which was once perceived to have only positive consequences, is now the focus of an intense debate that has managed to unite previously warring factions. This article utilizes a comparative assessment of CBM politics in Montana and Wyoming to explain the connection between changing popular and elite perceptions of the issue, institutional change, and policy change.

Duffy, R.J. [Colorado State University, Fort Collins, CO (United States)

2005-03-31T23:59:59.000Z

228

Evaluation of fluid bed heat exchanger optimization parameters. Final report  

SciTech Connect

Uncertainty in the relationship of specific bed material properties to gas-side heat transfer in fluidized beds has inhibited the search for optimum bed materials and has led to over-conservative assumptions in the design of fluid bed heat exchangers. An experimental program was carried out to isolate the effects of particle density, thermal conductivity, and heat capacitance upon fluid bed heat transfer. A total of 31 tests were run with 18 different bed material loads on 12 material types; particle size variations were tested on several material types. The conceptual design of a fluidized bed evaporator unit was completed for a diesel exhaust heat recovery system. The evaporator heat transfer surface area was substantially reduced while the physical dimensions of the unit increased. Despite the overall increase in unit size, the overall cost was reduced. A study of relative economics associated with bed material selection was conducted. For the fluidized bed evaporator, it was found that zircon sand was the best choice among materials tested in this program, and that the selection of bed material substantially influences the overall system costs. The optimized fluid bed heat exchanger has an estimated cost 19% below a fin augmented tubular heat exchanger; 31% below a commercial design fluid bed heat exchanger; and 50% below a conventional plain tube heat exchanger. The comparisons being made for a 9.6 x 10/sup 6/ Btu/h waste heat boiler. The fluidized bed approach potentially has other advantages such as resistance to fouling. It is recommended that a study be conducted to develop a systematic selection of bed materials for fluidized bed heat exchanger applications, based upon findings of the study reported herein.

Not Available

1980-03-01T23:59:59.000Z

229

Stochastic Consequence Analysis for Waste Leaks  

SciTech Connect

This analysis evaluates the radiological consequences of potential Hanford Tank Farm waste transfer leaks. These include ex-tank leaks into structures, underneath the soil, and exposed to the atmosphere. It also includes potential misroutes, tank overflow

HEY, B.E.

2000-05-31T23:59:59.000Z

230

Improved pyrolysis submodel for the Wen Fixed-Bed Gasifier Program  

Science Conference Proceedings (OSTI)

A generalized model for devolatilization of large coal particles typically encountered in a fixed or moving bed gasifier has been developed. Two models were developed, one which does not consider diffusion of the volatile matter from the coal during devolatilization and the other which does consider diffusion of volatile species through the coal matrix. Both models predict a time-temperature history of the particle in a convective heat transfer environment.

Adesanya, B.A.; Ruffin, Y.

1991-04-01T23:59:59.000Z

231

Improved pyrolysis submodel for the Wen Fixed-Bed Gasifier Program. Final report  

Science Conference Proceedings (OSTI)

A generalized model for devolatilization of large coal particles typically encountered in a fixed or moving bed gasifier has been developed. Two models were developed, one which does not consider diffusion of the volatile matter from the coal during devolatilization and the other which does consider diffusion of volatile species through the coal matrix. Both models predict a time-temperature history of the particle in a convective heat transfer environment.

Adesanya, B.A.; Ruffin, Y.

1991-04-01T23:59:59.000Z

232

Fluidized Bed Asbestos Sampler Design and Testing  

SciTech Connect

A large number of samples are required to characterize a site contaminated with asbestos from previous mine or other industrial operations. Current methods, such as EPA Region 10’s glovebox method, or the Berman Elutriator method are time consuming and costly primarily because the equipment is difficult to decontaminate between samples. EPA desires a shorter and less costly method for characterizing soil samples for asbestos. The objective of this was to design and test a qualitative asbestos sampler that operates as a fluidized bed. The proposed sampler employs a conical spouted bed to vigorously mix the soil and separate fine particulate including asbestos fibers on filters. The filters are then analyzed using transmission electron microscopy for presence of asbestos. During initial testing of a glass prototype using ASTM 20/30 sand and clay fines as asbestos surrogates, fine particulate adhered to the sides of the glass vessel and the tubing to the collection filter – presumably due to static charge on the fine particulate. This limited the fines recovery to ~5% of the amount added to the sand surrogate. A second prototype was constructed of stainless steel, which improved fines recovery to about 10%. Fines recovery was increased to 15% by either humidifying the inlet air or introducing a voltage probe in the air space above the sample. Since this was not a substantial improvement, testing using the steel prototype proceeded without using these techniques. Final testing of the second prototype using asbestos suggests that the fluidized bed is considerably more sensitive than the Berman elutriator method. Using a sand/tremolite mixture with 0.005% tremolite, the Berman elutriator did not segregate any asbestos structures while the fluidized bed segregated an average of 11.7. The fluidized bed was also able to segregate structures in samples containing asbestos at a 0.0001% concentration, while the Berman elutriator method did not detect any fibers at this concentration. Opportunities for improvement with the fluidized bed include improving reproducibility among replicates, increasing mass recovery, improving the lid gasket seal.

Karen E. Wright; Barry H. O'Brien

2007-12-01T23:59:59.000Z

233

Method for in situ gasification of a subterranean coal bed  

DOE Patents (OSTI)

The method of the present invention relates to providing controlled directional bores in subterranean earth formations, especially coal beds for facilitating in situ gasification operations. Boreholes penetrating the coal beds are interconnected by laser-drilled bores disposed in various arrays at selected angles to the major permeability direction in the coal bed. These laser-drilled bores are enlarged by fracturing prior to the gasification of the coal bed to facilitate the establishing of combustion zones of selected configurations in the coal bed for maximizing the efficiency of the gasification operation.

Shuck, Lowell Z. (Morgantown, WV)

1977-05-31T23:59:59.000Z

234

CONTROL OF INTERFACIAL DUST CAKE TO IMPROVE EFFICIENCY OF MOVING BED GRANULAR FILTERS  

Science Conference Proceedings (OSTI)

The goal of this research is to improve the performance of moving bed granular filters for gas cleaning at high temperatures and pressures. A second objective is to better understand dust capture interfacial phenomena and cake formation in moving bed filters. The experimental bed tested in the present study has several unique design features configured as cold flow, axially symmetric, counter-current flow to simulate a filter operating at high temperatures (1088 K) and elevated pressures (10 atmospheres). The granular filter is evaluated in two separate performance studies: (1) optimization of particle collection efficiency and bed pressure drop in a factorial study at near-atmospheric operating pressures through appropriate use of granular bed materials, particle sizes, and feed rates; and (2) high temperature and high pressure model simulation conducted at above-atmospheric pressures and room temperature utilizing dust and granular flow rates, granular size, system pressure, and superficial velocity. The factorial study involves a composite design of 16 near-atmospheric tests, while the model simulation study is comprised of 7 above-atmospheric tests. Similarity rules were validated in tests at four different mass dust ratios and showed nearly constant collection efficiencies ({approx} 99.5 {+-} 0.3%) for operating pressures of 160 kPa gage (23.2 psig) at room temperature (20 C), which simulates the hydrodynamic conditions expected for typical gasification streams (1088 K, 10 atmospheres). An important outcome from the near-atmospheric pressure studies are relationships developed using central composite design between the independent variables, superficial velocity (0.16-0.22 m/s), dust feed rate (0.08-0.74 kg/hr), and granular flow rate (3.32-15.4 kg/hr). These operating equations were optimized in contour plots for bed conditions that simultaneously satisfy low-pressure drop and high particle collection efficiency.

Robert C. Brown; Gerald M. Colver

2002-10-31T23:59:59.000Z

235

A staged fluidized-bed comubstion and filter system  

DOE Patents (OSTI)

A staged fluidized-bed combustion and filter system for substantially reducing the quantity of waste through the complete combustion into ash-type solids and gaseous products. The device has two fluidized- bed portions, the first primarily as a combustor/pyrolyzer bed, and the second as a combustor/filter bed. The two portions each have internal baffles to define stages so that material moving therein as fluidized beds travel in an extended route through those stages. Fluidization and movement is achieved by the introduction of gasses into each stage through a directional nozzle. Gases produced in the combustor/pyrolyzer bed are permitted to travel into corresponding stages of the combustor/filter bed through screen filters that permit gas flow but inhibit solids flow. Any catalyst used in the combustor/filter bed is recycled. The two beds share a common wall to minimize total volume of the system. A slightly modified embodiment can be used for hot gas desulfurization and sorbent regeneration. Either side-by-side rectangular beds or concentric beds can be used. The system is particularly suited to the processing of radioactive and chemically hazardous waste.

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

1993-12-31T23:59:59.000Z

236

Coal Bed Methane Protection Act (Montana) | Department of Energy  

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

Coal Bed Methane Protection Act (Montana) Coal Bed Methane Protection Act (Montana) Coal Bed Methane Protection Act (Montana) < Back Eligibility Utility Fed. Government Commercial Agricultural Investor-Owned Utility State/Provincial Govt Industrial Construction Municipal/Public Utility Local Government Rural Electric Cooperative Tribal Government Institutional Fuel Distributor Program Info State Montana Program Type Environmental Regulations Provider Montana Department of Natural Resources and Conservation The Coal Bed Methane Protection Act establishes a long-term coal bed methane protection account and a coal bed methane protection program for the purpose of compensating private landowners and water right holders for damage to land and to water quality and availability that is attributable to the development of coal bed methane wells. The Act aims to provide for

237

Coal Bed Sequestration of Carbon Dioxide  

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

COAL BED SEQUESTRATION OF CARBON DIOXIDE COAL BED SEQUESTRATION OF CARBON DIOXIDE R. Stanton (rstanton@usgs.gov; 703-648-6462) U.S. Geological Survey MS 956 National Center Reston, VA 20192 R. Flores (rflores@usgs.gov; 303-236-7774) U.S. Geological Survey MS 939, Denver Federal Center Denver, CO 80225 P.D. Warwick (pwarwick@usgs.gov; 703-648-6469) H. Gluskoter (halg@usgs.gov; 703-648-6429) U.S. Geological Survey MS 956 National Center Reston, VA 20192 G.D. Stricker (303-236-7763) U.S. Geological Survey MS 939, Denver Federal Center Denver, CO 80225 Introduction Geologic sequestration of CO 2 generated from fossil fuel combustion may be an environmentally attractive method to reduce the amount of greenhouse gas emissions. Of the geologic options, sequestering CO

238

Fluidized bed gasification of extracted coal  

DOE Patents (OSTI)

Coal or similar carbonaceous solids are extracted by contacting the solids in an extraction zone (12) with an aqueous solution having a pH above 12.0 at a temperature between 65.degree. C. and 110.degree. C. for a period of time sufficient to remove bitumens from the coal into said aqueous solution and the extracted solids are then gasified at an elevated pressure and temperature in a fluidized bed gasification zone (60) wherein the density of the fluidized bed is maintained at a value above 160 kg/m.sup.3. In a preferred embodiment of the invention, water is removed from the aqueous solution in order to redeposit the extracted bitumens onto the solids prior to the gasification step.

Aquino, Dolores C. (Houston, TX); DaPrato, Philip L. (Westfield, NJ); Gouker, Toby R. (Baton Rouge, LA); Knoer, Peter (Houston, TX)

1986-01-01T23:59:59.000Z

239

Fluidized bed gasification of extracted coal  

DOE Patents (OSTI)

Coal or similar carbonaceous solids are extracted by contacting the solids in an extraction zone with an aqueous solution having a pH above 12.0 at a temperature between 65/sup 0/C and 110/sup 0/C for a period of time sufficient to remove bitumens from the coal into said aqueous solution, and the extracted solids are then gasified at an elevated pressure and temperature in a fluidized bed gasification zone (60) wherein the density of the fluidized bed is maintained at a value above 160 kg/m/sup 3/. In a preferred embodiment of the invention, water is removed from the aqueous solution in order to redeposit the extracted bitumens onto the solids prior to the gasification step. 2 figs., 1 tab.

Aquino, D.C.; DaPrato, P.L.; Gouker, T.R.; Knoer, P.

1984-07-06T23:59:59.000Z

240

Fluidized bed boiler having a segmented grate  

DOE Patents (OSTI)

A fluidized bed furnace (10) is provided having a perforate grate (9) within a housing which supports a bed of particulate material including some combustibles. The grate is divided into a plurality of segments (E2-E6, SH1-SH5, RH1-RH5), with the airflow to each segment being independently controlled. Some of the segments have evaporating surface imbedded in the particulate material above them, while other segments are below superheater surface or reheater surface. Some of the segments (E1, E7) have no surface above them, and there are ignitor combustors (32, 34) directed to fire into the segments, for fast startup of the furnace without causing damage to any heating surface.

Waryasz, Richard E. (Longmeadow, MA)

1984-01-01T23:59:59.000Z

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


241

Cluster Dynamics in a Circulating Fluidized Bed  

Science Conference Proceedings (OSTI)

A common hydrodynamic feature in industrial scale circulating fluidized beds is the presence of clusters. The continuous formation and destruction of clusters strongly influences particle hold-up, pressure drop, heat transfer at the wall, and mixing. In this paper fiber optic data is analyzed using discrete wavelet analysis to characterize the dynamic behavior of clusters. Five radial positions at three different axial locations under five different operating were analyzed using discrete wavelets. Results are summarized with respect to cluster size and frequency.

Guenther, C.P.; Breault, R.W.

2006-11-01T23:59:59.000Z

242

NUCLA Circulating Atmospheric Fluidized Bed Demonstration Project  

Science Conference Proceedings (OSTI)

The objective of this DOE Cooperative Agreement is to conduct a cost-shared clean coal technology project to demonstrate the feasibility of circulating fluidized bed combustion technology and to evaluate economic, environmental, and operational benefits of CFB steam generators on a utility scale. At the conclusion of the Phase 2 program, testing related to satisfying these objectives was completed. Data analysis and reporting are scheduled for completion by October 1991. (VC)

Not Available

1992-02-01T23:59:59.000Z

243

Reducing mode circulating fluid bed combustion  

DOE Patents (OSTI)

A method for combustion of sulfur-containing fuel in a circulating fluid bed combustion system wherein the fuel is burned in a primary combustion zone under reducing conditions and sulfur captured as alkaline sulfide. The reducing gas formed is oxidized to combustion gas which is then separated from solids containing alkaline sulfide. The separated solids are then oxidized and recycled to the primary combustion zone.

Lin, Yung-Yi (Katy, TX); Sadhukhan, Pasupati (Katy, TX); Fraley, Lowell D. (Sugarland, TX); Hsiao, Keh-Hsien (Houston, TX)

1986-01-01T23:59:59.000Z

244

Pulsed atmospheric fluidized bed combustor apparatus  

DOE Patents (OSTI)

A pulsed atmospheric fluidized bed reactor system is disclosed and claimed along with a process for utilization of same for the combustion of, e.g. high sulfur content coal. The system affords a economical, ecologically acceptable alternative to oil and gas fired combustors. The apparatus may also be employed for endothermic reaction, combustion of waste products, e.g., organic and medical waste, drying materials, heating air, calcining and the like.

Mansour, Momtaz N. (Columbia, MD)

1993-10-26T23:59:59.000Z

245

Reference repository design concept for bedded salt  

Science Conference Proceedings (OSTI)

A reference design concept is presented for the subsurface portions of a nuclear waste repository in bedded salt. General geologic, geotechnical, hydrologic and geochemical data as well as descriptions of the physical systems are provided for use on generic analyses of the pre- and post-sealing performance of repositories in this geologic medium. The geology of bedded salt deposits and the regional and repository horizon stratigraphy are discussed. Structural features of salt beds including discontinuities and dissolution features are presented and their effect on repository performance is discussed. Seismic hazards and the potential effects of earthquakes on underground repositories are presented. The effect on structural stability and worker safety during construction from hydrocarbon and inorganic gases is described. Geohydrologic considerations including regional hydrology, repository scale hydrology and several hydrological failure modes are presented in detail as well as the hydrological considerations that effect repository design. Operational phase performance is discussed with respect to operations, ventilation system, shaft conveyances, waste handling and retrieval systems and receival rates of nuclear waste. Performance analysis of the post sealing period of a nuclear repository is discussed, and parameters to be used in such an analysis are presented along with regulatory constraints. Some judgements are made regarding hydrologic failure scenarios. Finally, the design and licensing process, consistent with the current licensing procedure is described in a format that can be easily understood.

Carpenter, D.W.; Martin, R.W.

1980-10-08T23:59:59.000Z

246

The Institutional Consequences of Congressional Polarization  

E-Print Network (OSTI)

Polarization, defined as the ideological distance between the Democrat and Republican parties in Congress, has increased dramatically in Congress since the 1970s. Research on polarization in the U.S. Congress primarily focuses on the sources of this increase. Relatively little work has been done on the consequences of polarization for Congress? relationship with the president and the passage of legislation. This dissertation corrects this omission by examining the influence of polarization on several key aspects of the legislative process. It examines the impact of polarization on the interaction between Congress and the president, including the president?s strategy in supporting or opposing legislation and the success the president has on bills when he takes a position. It also examines the effect polarization has on the overall passage of legislation. An empirical examination was undertaken using significant bills in Congress over a sixty year time period (1947-2006). The results indicate that the effects of polarization on the legislative process are contingent upon the presence of divided government, defined as times when the president and a majority of members of Congress are from different parties, and the chamber of Congress under examination. As polarization increases, the president is more likely to support legislation and be successful when his party controls Congress, but he opposes more legislation and is less successful as polarization increases under divided government. Legislative gridlock, the inability of Congress to pass important or innovative legislation, tends to decrease in both the House and Senate as polarization increases under unified government. However, as polarization increases under divided government the overall passage of bills into law decreases. The dissertation also offers an improved method for modeling the impact of divided government on gridlock. Prior studies model divided government without regard for whether the president takes a position on a given bill. This study shows that when the president takes a position on a bill under divided government the probability it passes decreases, but the probability of passage increases when the president does not take a position. This finding implies that previous research may underestimate the true effects of divided government on gridlock.

Ilderton, Nathan A.

2009-12-01T23:59:59.000Z

247

Fossil fuel conversion -- Measurement and modeling. Topical report, September 14, 1993--June 30, 1997  

Science Conference Proceedings (OSTI)

Progress is described on the following tasks: Fixed-bed devolatilization processes; Fixed-bed combustion and gasification processes; Physical processes in transport reactors; Chemical processes in transport reactors; Advanced fixed-bed model development and evaluation; Advanced two-dimensional transport reactor model development and evaluation; Modeling of gas phase combustion; Modeling of fluidized bed systems; Advanced fixed-bed code application and implementation; Advanced two-dimensional transport gasification code applications and implementation; Modeling of fluidized-bed system applications and implementation; and Applications of ACERC combustion and gasification codes and AFR diagnostic capabilities to systems of interest to METC.

NONE

1997-12-31T23:59:59.000Z

248

Tritium measurement technique using in-bed'' calorimetry  

DOE Green Energy (OSTI)

One of the new technologies that has been introduced to the Savannah River Site (SRS) is the production scale use of metal hydride technology to store, pump, and compress hydrogen isotopes. For tritium stored in metal hydride storage beds, a unique relationship does not exist between the amount of tritium in the bed and the pressure-volume-temperature properties of the hydride material. Determining the amount of tritium in a hydride bed after desorbing the contents of the bed to a tank and performing pressure, volume, temperature, and composition (PVTC) measurements is not practical due to long desorption/absorption times and the inability to remove tritium heels'' from the metal hydride materials under normal processing conditions. To eliminate the need to remove tritium from hydride storage beds for measurement purposes, and in-bed'' tritium calorimetric measurement technique has been developed. The steady-state temperature rise of a gas stream flowing through a jacketed metal hydride storage bed is measured and correlated with power input to electric heaters used to simulate the radiolytic power generated by the decay of tritium to {sup 3}He. Temperature rise results for prototype metal hydride storage beds and the effects of using different gases in the bed are shown. Linear regression results shows that for 95% confidence intervals, temperature rise measurements can be obtained in 14 hours and have an accuracy of {plus minus}1.6% of a tritium filled hydride storage bed.

Klein, J.E.; Mallory, M.K.; Nobile, A. Jr.

1991-01-01T23:59:59.000Z

249

Tritium measurement technique using ``in-bed`` calorimetry  

DOE Green Energy (OSTI)

One of the new technologies that has been introduced to the Savannah River Site (SRS) is the production scale use of metal hydride technology to store, pump, and compress hydrogen isotopes. For tritium stored in metal hydride storage beds, a unique relationship does not exist between the amount of tritium in the bed and the pressure-volume-temperature properties of the hydride material. Determining the amount of tritium in a hydride bed after desorbing the contents of the bed to a tank and performing pressure, volume, temperature, and composition (PVTC) measurements is not practical due to long desorption/absorption times and the inability to remove tritium ``heels`` from the metal hydride materials under normal processing conditions. To eliminate the need to remove tritium from hydride storage beds for measurement purposes, and ``in-bed`` tritium calorimetric measurement technique has been developed. The steady-state temperature rise of a gas stream flowing through a jacketed metal hydride storage bed is measured and correlated with power input to electric heaters used to simulate the radiolytic power generated by the decay of tritium to {sup 3}He. Temperature rise results for prototype metal hydride storage beds and the effects of using different gases in the bed are shown. Linear regression results shows that for 95% confidence intervals, temperature rise measurements can be obtained in 14 hours and have an accuracy of {plus_minus}1.6% of a tritium filled hydride storage bed.

Klein, J.E.; Mallory, M.K.; Nobile, A. Jr.

1991-12-31T23:59:59.000Z

250

Retail Price Drivers and their Financial Consequences  

E-Print Network (OSTI)

making the data available. Retail Price Drivers and their Financial Consequences What are the drivers of retailers ' prices and what, if any, are their financial consequences? The results of a large-scale quantitative analysis show that retail prices are mainly driven by pricing history (50%), acquisition costs (25%), and demand feedback (12.5%). In contrast to pricing history, demand-based pricing is associated with higher retailer (and manufacturer) financial performance. The remaining price drivers: category management, store traffic, and store brand performance, affect manufacturer and retailer performance in more complex ways.

Shuba Srinivasan; Koen Pauwels; Vincent Nijs; Mike Hanssens; Carl Mela; Scott Neslin For Comments; Suggestions The Paper

2003-01-01T23:59:59.000Z

251

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

DOE Green Energy (OSTI)

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

Kevin Whitty

2007-06-30T23:59:59.000Z

252

In-bed tube bank for a fluidized-bed combustor  

DOE Patents (OSTI)

An in-bed tube bank (10) for a fluidized bed combustor. The tube bank (10) of the present invention comprises one or more fluid communicating boiler tubes (30) which define a plurality of selectively spaced boiler tube sections (32). The tube sections (32) are substantially parallel to one another and aligned in a common plane. The tube bank (10) further comprises support members (34) for joining adjacent tube sections (32), the support members (34) engaging and extending along a selected length of the tube sections (32) and spanning the preselected space therebetween.

Hemenway, Jr., Lloyd F. (Morgantown, WV)

1990-01-01T23:59:59.000Z

253

Review of BEIS3 Formulation and Consequences Relative to Air Quality Standards: Estimation of Effects of Uncertainties in BEIS3 Emissions on Uncertainties in Ozone Predictions by Chemical Transport Models  

Science Conference Proceedings (OSTI)

The U.S. Environmental Protection Agency (EPA) developed the Biogenics Emissions Inventory System, Version 3 (BEIS3) to estimate emissions of biogenic substances such as isoprene, monoterpenes, oxygenated volatile organic compounds, and biogenic nitric oxide. These biogenic emissions are inputs to chemical transport models (CTMs) used for calculating ambient concentrations of ozone and other pollutants. The outputs of the CTMs are then used to set policies concerning emission reductions needed from indus...

2003-07-17T23:59:59.000Z

254

Theoretical and experimental studies of fixed-bed coal gasification reactors. Final report  

Science Conference Proceedings (OSTI)

A laboratory fixed-bed gasification reactor was designed and built with the objective of collecting operational data for model validation and parameter estimation. The reactor consists of a 4 inch stainless steel tube filled with coal or char. Air and steam is fed at one end of the reactor and the dynamic progress of gasification in the coal or char bed is observed through thermocouples mounted at various radial and axial locations. Product gas compositions are also monitored as a function of time. Results of gasification runs using Wyoming coal are included in this report. In parallel with the experimental study, a two-dimensional model of moving bed gasifiers was developed, coded into a computer program and tested. This model was used to study the laboratory gasifier by setting the coal feed rate equal to zero. The model is based on prior work on steady state and dynamic modeling done at Washington University and published elsewhere in the literature. Comparisons are made between model predictions and experimental results. These are also included in this report. 23 references, 18 figures, 6 tables.

Joseph, B.; Bhattacharya, A.; Salam, L.; Dudukovic, M.P.

1983-09-01T23:59:59.000Z

255

EIS-0289: JEA Circulating Fluidized Bed Combustor Project | Department of  

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

289: JEA Circulating Fluidized Bed Combustor Project 289: JEA Circulating Fluidized Bed Combustor Project EIS-0289: JEA Circulating Fluidized Bed Combustor Project SUMMARY This EIS assesses environmental issues associated with constructing and demonstrating a project that would be cost-shared by DOE and JEA (formerly the Jacksonville Electric Authority) under the Clean Coal Technology Program. PUBLIC COMMENT OPPORTUNITIES None available at this time. DOCUMENTS AVAILABLE FOR DOWNLOAD December 7, 2000 EIS-0289: Record of Decision JEA Circulating Fluidized Bed Combustor Project, Jacksonville, Duval County, FL June 1, 2000 EIS-0289: Final Environmental Impact Statement JEA Circulating Fluidized Bed Combustor Project August 1, 1999 EIS-0289: Draft Environmental Impact Statement JEA Circulating Fluidized Bed Combustor

256

Geomechanical Analysis and Design Considerations for Thin-Bedded Salt Caverns  

Science Conference Proceedings (OSTI)

The bedded salt formations located throughout the United States are layered and interspersed with non-salt materials such as anhydrite, shale, dolomite and limestone. The salt layers often contain significant impurities. GRI and DOE have initialized this research proposal in order to increase the gas storage capabilities by providing operators with improved geotechnical design and operating guidelines for thin bedded salt caverns. Terralog has summarized the geologic conditions, pressure conditions, and critical design factors that may lead to: (1) Fracture in heterogeneous materials; (2) Differential deformation and bedding plane slip; (3) Propagation of damage around single and multiple cavern; and (4) Improved design recommendations for single and multiple cavern configurations in various bedded salt environments. The existing caverns within both the Permian Basin Complex and the Michigan and Appalachian Basins are normally found between 300 m to 1,000 m (1,000 ft to 3,300 ft) depth depending on local geology and salt dissolution depth. Currently, active cavern operations are found in the Midland and Anadarko Basins within the Permian Basin Complex and in the Appalachian and Michigan Basins. The Palo Duro and Delaware Basins within the Permian Basin Complex also offer salt cavern development potential. Terralog developed a number of numerical models for caverns located in thin bedded salt. A modified creep viscoplastic model has been developed and implemented in Flac3D to simulate the response of salt at the Permian, Michigan and Appalachian Basins. The formulation of the viscoplastic salt model, which is based on an empirical creep law developed for Waste Isolation Pilot Plant (WIPP) Program, is combined with the Drucker-Prager model to include the formation of damage and failure. The Permian salt lab test data provided by Pfeifle et al. 1983, are used to validate the assumptions made in the material model development. For the actual cavern simulations two baseline models are developed for single and multiple caverns, respectively. Different parameters that affect damage propagation and deformation of salt cavern, such as cavern pressure, operating conditions, cavern height/diameter ratio, overburden stiffness and roof thickness are analyzed and the respective results summarized. For multiple horizontal caverns numerical models are developed to determine the cavern interaction and the minimum safe center to center distance. A step by step methodology for operators to assess critical cavern design parameters for thin bedded salt formations is also presented.

Michael S. Bruno

2005-06-15T23:59:59.000Z

257

Compact nuclear power systems based on particle bed reactors  

SciTech Connect

Compact, low cost nuclear power systems with an extremely low radioactive inventory are described. These systems use the Particle Bed Reactor (PBR), in which HTGR particle fuel is contained in packed beds that are changed daily. The small diameter particle fuel (500 ..mu..m) is directly cooled utilizing the large heat transfer area available (7.8 m/sup 2//liter), thus allowing high bed power densities (MW/liter).

Horn, F.L.; Powell, J.R.; Steinberg, M.; Takahashi, H.

1986-01-01T23:59:59.000Z

258

Atmospheric Fluidized Bed Combustion for Power Production from Biomass  

Science Conference Proceedings (OSTI)

Atmospheric fluidized bed combustion (AFBC) technologyincluding smaller bubbling fluidized bed (BFB) as well as circulating fluidized bed (CFB) combustor unitsprovides robust combustion with high thermal inertia. This means that AFBC units can successfully respond to variations in ash content, calorific value, and moisture content commonly encountered in burning biomass fuels. This report describes AFBC technology and its deployment for generating steam for power plants using a wide variety of biomass fu...

2010-01-28T23:59:59.000Z

259

Fluidized-bed calciner with combustion nozzle and shroud  

DOE Patents (OSTI)

A nozzle employed as a burner within a fluidized bed is coaxially enclosed within a tubular shroud that extends beyond the nozzle length into the fluidized bed. The open-ended shroud portion beyond the nozzle end provides an antechamber for mixture and combustion of atomized fuel with an oxygen-containing gas. The arrangement provides improved combustion efficiency and excludes bed particles from the high-velocity, high-temperature portions of the flame to reduce particle attrition.

Wielang, Joseph A. (Idaho Falls, ID); Palmer, William B. (Shelley, ID); Kerr, William B. (Idaho Falls, ID)

1977-01-01T23:59:59.000Z

260

Storage opportunities in Arizona bedded evaporites  

DOE Green Energy (OSTI)

Arizona is endowed with incredibly diverse natural beauty, and has also been blessed with at least seven discrete deposits of bedded salt. These deposits are dispersed around the state and cover some 2, 500 square miles; they currently contain 14 LPG storage caverns, with preliminary plans for more in the future. The areal extent and thickness of the deposits creates the opportunity for greatly expanded storage of LPG, natural gas, and compressed air energy storage (CAES). The location of salt deposits near Tucson and Phoenix may make CAES an attractive prospect in the future. The diversity of both locations and evaporate characteristics allows for much tailoring of individual operations to meet specific requirements.

Neal, J.T. [Sandia National Labs., Albuquerque, NM (United States); Rauzi, S.L. [Arizona Geological Survey, Tucson, AZ (United States)

1996-10-01T23:59:59.000Z

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


261

Nucla circulating atmospheric fluidized bed demonstration project  

Science Conference Proceedings (OSTI)

During the fourth quarter of 1990, steady-state performance testing at the Nucla Circulating Fluidized Bed (CFB) resumed under sponsorship of the US Department of Energy. Co-sponsorship of the Demonstration Test Program by the Electric Power Research Institute (EPRI) was completed on June 15, 1990. From October through December, 1990, Colorado-Ute Electric Association (CUEA) completed a total of 23 steady-state performance tests, 4 dynamic tests, and set operating records during November and December as the result of improved unit operating reliability. Highlight events and achievements during this period of operation are presented.

Not Available

1991-01-31T23:59:59.000Z

262

Pyrolysis reactor and fluidized bed combustion chamber  

DOE Patents (OSTI)

A solid carbonaceous material is pyrolyzed in a descending flow pyrolysis reactor in the presence of a particulate source of heat to yield a particulate carbon containing solid residue. The particulate source of heat is obtained by educting with a gaseous source of oxygen the particulate carbon containing solid residue from a fluidized bed into a first combustion zone coupled to a second combustion zone. A source of oxygen is introduced into the second combustion zone to oxidize carbon monoxide formed in the first combustion zone to heat the solid residue to the temperature of the particulate source of heat.

Green, Norman W. (Upland, CA)

1981-01-06T23:59:59.000Z

263

NUCLA Circulating Atmospheric Fluidized Bed Demonstration Project  

Science Conference Proceedings (OSTI)

This Annual Report on Colorado-Ute Electric Association's NUCLA Circulating Fluidized Bed (CFB) Demonstration Program covers the period from February 1987 through December 1988. The outline for presentation in this report includes a summary of unit operations along with individual sections covering progress in study plan areas that commenced during this reporting period. These include cold-mode shakedown and calibration, plant commercial performance statistics, unit start-up (cold), coal and limestone preparation and handling, ash handling system performance and operating experience, tubular air heater, baghouse operation and performance, materials monitoring, and reliability monitoring. During this reporting period, the coal-mode shakedown and calibration plan was completed. (VC)

Not Available

1991-01-01T23:59:59.000Z

264

Gas fluidized-bed stirred media mill  

DOE Patents (OSTI)

A gas fluidized-bed stirred media mill is provided for comminuting solid ticles. The mill includes a housing enclosing a porous fluidizing gas diffuser plate, a baffled rotor and stator, a hollow drive shaft with lateral vents, and baffled gas exhaust exit ports. In operation, fluidizing gas is forced through the mill, fluidizing the raw material and milling media. The rotating rotor, stator and milling media comminute the raw material to be ground. Small entrained particles may be carried from the mill by the gas through the exit ports when the particles reach a very fine size.

Sadler, III, Leon Y. (Tuscaloosa, AL)

1997-01-01T23:59:59.000Z

265

Community-Based Energy Development (C-BED) Tariff (Minnesota...  

Open Energy Info (EERE)

with form History Share this page on Facebook icon Twitter icon Community-Based Energy Development (C-BED) Tariff (Minnesota) Production Incentive This is the approved...

266

CERTS Microgrid Laboratory Test Bed - PIER Final Project Report  

E-Print Network (OSTI)

Laboratory Test Bed. California Energy Commission, PublicCERTS Microgrid”, California Energy Commission R&D Forum, 4CERTS Microgrid”, California Energy Commission R&D Forum, 4

Eto, Joseph H.

2008-01-01T23:59:59.000Z

267

Compost Bedded Pack Barns: Management Practices and Economic Implications.  

E-Print Network (OSTI)

??Compost bedded pack (CBP) barn design and pack maintenance procedures vary considerably, making advising and problem-solving challenging. One objective of this research was to characterize… (more)

Black, Randi Alyson

2013-01-01T23:59:59.000Z

268

Hybrid Molten Bed Gasifier for High Hydrogen Syngas Production  

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

Hybrid Molten Bed Gasifier for High Hydrogen (H2) Syngas Production Gas Technology Institute (GTI) Project Number: FE0012122 Project Description The research team will evaluate and...

269

Evaluation of Fluid Transport Properties of Coal Bed Methane Reservoirs.  

E-Print Network (OSTI)

??Determination of petro-physical properties of coal bed methane (CBM) reservoirs is essential in evaluating a potential prospect for commercial exploitation. In particular, permeability is the… (more)

Alexis, Dennis Arun

2013-01-01T23:59:59.000Z

270

Resource Recovery of Coal Bed Methane Formation Water.  

E-Print Network (OSTI)

??During the excavation of natural gas, petroleum hydrocarbon-polluted brine water, termed production water, is drawn from the coal bed methane formations (CBMF) along with the… (more)

Bishop, Catherine Elizabeth

2006-01-01T23:59:59.000Z

271

Circulating Moving Bed Combustion Proof-of-concept  

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

combustor, the solids are fluidized and transferred through standpipes to a moving bed heat exchanger (MBHE). There, an energy cycle working fluid, such as steam or compressed...

272

Heat transfer characteristics of a fluidized bed : stirling engine system.  

E-Print Network (OSTI)

??A fluidized bed combustion (FBC) system was designed to provide heat energy to the head of a Stirling cycle engine. Preliminary testing with a simulated… (more)

Anzalone, Thomas M.

1989-01-01T23:59:59.000Z

273

Improvement of Product Quality in Circulating Fluidized Bed ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Until the introduction of Circulating Fluidized Bed (CFB) Calciners by Outotec (formerly Lurgi) in 1961 rotary kilns were the standard technology ...

274

Fact Sheet, Consequences of a Positive Drug Test - September...  

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

Consequences of a Positive Drug Test - September 14, 2007 Fact Sheet, Consequences of a Positive Drug Test - September 14, 2007 September 14, 2007 Fact Sheet on the Consequences of...

275

Distributed measurements of tracer response on packed bed flows using a fiberoptic probe array. Final report  

Science Conference Proceedings (OSTI)

Scale-up of packed bed processes, particularly those involving chromatographic separations, is made difficult by a seemingly inevitable increase in dispersion due to packing nonuniformity. To provide a suitable characterization, the authors measured the spatial distribution of dispersion and mixing in packed beds of uniform impervious spherical glass particles by a tracer impulse technique. The key feature in this work is the use of a fiberoptic array at the exit plane to obtain a time-resolved spatially distributed response. All experiments were in the creeping flow regime. The authors used a fluorescent dye with laser excitation through the fiber terminations in the bed. The fluoresced radiation was collected through the same fibers. They analyzed the data by the use of indices of the extent of micromixing based on Danckwerts`s original degree of segregation and an additional index of structural uniformity. The computations involve a moment analysis of the individual and average probe responses. A simple model gives expressions for the indices in terms of the Peclet number and is shown to provide a useful limiting case. The computed indices are also shown to be very sensitive to adsorption of dye on the surface of the glass. However, for some of the experiments with the largest spheres using Pyrex glass, the effects of adsorption are indiscernible. This technique successfully separates the contribution of micromixed fluid to overall bed dispersion from the contribution due to the transverse variation of the flow residence time.

Jones, M.C.; Nassimbene, R.; Wolfe, J. [National Inst. of Standards and Technology, Boulder, CO (United States). Chemical Science and Technology Lab.; Frederick, N. [Rocky Mountain Electron Video, Boulder, CO (United States)

1994-10-28T23:59:59.000Z

276

Data center design and location: Consequences for electricity...  

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

Data center design and location: Consequences for electricity use and greenhouse-gas emissions Title Data center design and location: Consequences for electricity use and...

277

An Experimental Test Bed for Small Unmanned Helicopters  

Science Conference Proceedings (OSTI)

This paper introduces a custom experimental test bed for the evaluation of autonomous flight controllers for unmanned helicopters. The development of controllers for unmanned helicopters is a difficult procedure which involves testing through simulation ... Keywords: Aerial robotics, Experimental test bed, Flight control, Fuzzy control, Unmanned helicopters

Nikos I. Vitzilaios; Nikos C. Tsourveloudis

2009-05-01T23:59:59.000Z

278

Consequences of intensity constraints on inertial confinement fusion  

SciTech Connect

It is shown that the conflicting requirements of high implosion efficiency (low corona temperature) and adequate energy transport (high corona temperature) can, together with other effects, limit useful infrared light intensities to values on the order of 100 Tw/cm/sup 2/. Increased interest in ultraviolet lasers, for which this intensity constraint is expected to be less severe, and the entry of charged-particle drivers in the inertial confinement fusion (ICF) competition are consequences of this limitation. Analytical results based on a simple model are presented which show how the gain of an ICF target is modified by the existence of an arbitrary intensity constraint.

Kidder, R.E.

1979-09-13T23:59:59.000Z

279

Technology Maturation Plan (TMP) Fluidized Bed Steam Reforming (FBSR)  

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

Maturation Plan (TMP) Fluidized Bed Steam Reforming Maturation Plan (TMP) Fluidized Bed Steam Reforming (FBSR) Technology for Tank 48H Treatment Project (TTP) Technology Maturation Plan (TMP) Fluidized Bed Steam Reforming (FBSR) Technology for Tank 48H Treatment Project (TTP) This assessment determines the technology maturity level of the candidate Tank 48H treatment technologies that are being considered for implementation at DOE's SRS - specifically Fluidized Bed Steam Reformer System. Technology Maturation Plan (TMP) Fluidized Bed Steam Reforming (FBSR) Technology for Tank 48H Treatment Project (TTP) More Documents & Publications Technology Maturation Plan (TMP) Wet Air Oxidation (WAO) Technology for Tank 48H Treatment Project (TTP) SRS Tank 48H Waste Treatment Project Technology Readiness Assessment

280

Nucla circulating atmospheric fluidized bed demonstration project  

Science Conference Proceedings (OSTI)

Colorado-Ute Electric Association began a study to evaluate options for upgrading and extending the life of its Nucla power station in 1982. Located in southwestern Colorado near the town of Nucla, this station was commissioned in 1959 with a local bituminous coal as its design fuel for three identical stoker-fired units, each rated at 12.6 MW(e). Poor station efficiency, high fuel costs, and spiraling boiler maintenance costs forced the Nucla Station into low priority in the CUEA dispatch order as early as 1981. Among the options CUEA considered was to serve as a host utility to demonstrate Atmospheric Fluidized Bed Combustion (AFBC) technology. The anticipated environmental benefits and apparent attractive economics of a circulating AFBC led to Colorado-Ute's decision to proceed with the design and construction of a demonstration project in 1984 at the Nucla facility.

Not Available

1991-10-01T23:59:59.000Z

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


281

Circulating Fluidized Bed Combustion Boiler Project  

E-Print Network (OSTI)

The project to build a PYROFLOW circulating fluidized bed combustion (FBC) boiler at the BFGoodrich Chemical Plant at Henry, Illinois, is described. This project is being partially funded by Illinois to demonstrate the feasibility of utilizing high-sulfur Illinois coal. Design production is 125,000 pounds per hour of 400 psig saturated steam. An Illinois EPA construction permit has been received, engineering design is under way, major equipment is on order, ground breaking occurred in January 1984 and planned commissioning date is late 1985. This paper describes the planned installation and the factors and analyses used to evaluate the technology and justify the project. Design of the project is summarized, including the boiler performance requirements, the PYROFLOW boiler, the coal, limestone and residue handling systems and the pollutant emission limitations.

Farbstein, S. B.; Moreland, T.

1984-01-01T23:59:59.000Z

282

Synthetic aggregate compositions derived from spent bed materials from fluidized bed combustion and fly ash  

DOE Patents (OSTI)

Cementitious compositions useful as lightweight aggregates are formed from a blend of spent bed material from fluidized bed combustion and fly ash. The proportions of the blend are chosen so that ensuing reactions eliminate undesirable constituents. The blend is then mixed with water and formed into a shaped article. The shaped article is preferably either a pellet or a "brick" shape that is later crushed. The shaped articles are cured at ambient temperature while saturated with water. It has been found that if used sufficiently, the resulting aggregate will exhibit minimal dimensional change over time. The aggregate can be certified by also forming standardized test shapes, e.g., cylinders while forming the shaped articles and measuring the properties of the test shapes using standardized techniques including X-ray diffraction.

Boyle, Michael J. (Aston, PA)

1994-01-01T23:59:59.000Z

283

Coal-Fired Fluidized Bed Combustion Cogeneration  

E-Print Network (OSTI)

The availability of an environmentally acceptable multifuel technology, such as fluidized bed combustion, has encouraged many steam producers/ users to investigate switching from oil or gas to coal. Changes in federal regulations encouraging cogeneration have further enhanced the economic incentives for primary fuel switching. However, this addition of cogeneration to the fuel conversion analysis considerably complicates the investigation. A system design for cogeneration of steam and electricity at a nominal 40,000 pound per hour capacity utilizing fluidized bed combustion is described. The basic system incorporates silo storage of coal, ash, and limestone with dense phase conveying. The system generates power utilizing either a backpressure turbine or a condensing turbine with steam extraction. Three case studies performed for specific end users are presented. The interaction among plant steam requirements, rate purchase structure, and electrical energy buy back rate is discussed. How these factors interact determine the final design and the choice of fuels is illustrated. Because the decision to switch fuel, as well as to cogenerate, is usually economically motivated, an in-depth understanding of the steam/electrical needs and interactions is critical. How these considerations are integrated in the system and the effect they have on the monetary returns are discussed. Electric rate agreements vary significantly from one state to another. Therefore, the examples selected are intended to provide, insight into this variability. For example, one rate structure encourages solid fuel cogeneration. The second is a block structure with low sell back rates making cogeneration difficult to justify. How these rate schedules affected the recommended design illustrates that the system selection is very important.

Thunem, C.; Smith, N.

1985-05-01T23:59:59.000Z

284

Method for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier  

DOE Patents (OSTI)

A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600.degree. to 1800.degree. F. and are partially quenched with water to 1000.degree. to 1200.degree. F. before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime/limestone.

Grindley, Thomas (Morgantown, WV)

1989-01-01T23:59:59.000Z

285

CARBON BED MERCURY EMISSIONS CONTROL FOR MIXED WASTE TREATMENT  

Science Conference Proceedings (OSTI)

Mercury has had various uses in nuclear fuel reprocessing and other nuclear processes, and so is often present in radioactive and mixed (both radioactive and hazardous according tohe Resource Conservation and Recovery Act) wastes. Depending on regulatory requirements, the mercury in the off-gas must be controlled with sometimes very high efficiencies. Compliance to the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards can require off-gas mercury removal efficiencies up to 99.999% for thermally treating some mixed waste streams. Several test programs have demonstrated this level of off-gas mercury control using fixed beds of granular sulfur-impregnated activated carbon. Other results of these tests include: (a) The depth of the mercury control mass transfer zone was less than 15-30 cm for the operating conditions of these tests, (b) MERSORB® carbon can sorb Hg up to 19 wt% of the carbon mass, and (c) the spent carbon retained almost all (98 – 99.99%) of the Hg; but when even a small fraction of the total Hg dissolves, the spent carbon can fail the TCLP test when the spent carbon contains high Hg concentrations. Localized areas in a carbon bed that become heated through heat of adsorption, to temperatures where oxidation occurs, are referred to as “bed hot spots.” Carbon bed hot spots must be avoided in processes that treat radioactive and mixed waste. Key to carbon bed hot spot mitigation are (a) designing for sufficient gas velocity, for avoiding gas flow maldistribution, and for sufficient but not excessive bed depth, (b) monitoring and control of inlet gas flowrate, temperature, and composition, (c) monitoring and control of in-bed and bed outlet gas temperatures, and (d) most important, monitoring of bed outlet CO concentrations. An increase of CO levels in the off-gas downstream of the carbon bed to levels about 50-100 ppm higher than the inlet CO concentration indicate CO formation in the bed, caused by carbon bed hot spots. Corrective actions must be implemented quickly if bed hot spots are detected, using a graded approach and sequence starting with corrective actions that are simple, quick, cause the least impact to the process, and are easiest to recover from. Multiple high and high-high alarm levels should be used, with appropriate corrective actions for each level.

Nick Soelberg; Joe Enneking

2010-11-01T23:59:59.000Z

286

Storm tide impact and consequence modelling: Some preliminary observations  

Science Conference Proceedings (OSTI)

The rapid growth of urban development in coastal areas of Queensland (Australia) has significantly increased the number of people exposed to the risk of storm tides generated by tropical cyclones. To gain a better understanding of the vulnerability and ... Keywords: Cyclone, Hazard, Risk, Storm tide, Vulnerability

K. J. Granger; D. I. Smith

1995-05-01T23:59:59.000Z

287

Alongshore advection and marine reserves: consequences for modeling and management  

E-Print Network (OSTI)

between the 2 systems (Hockey & Branch 1994, Simberloffworld fisheries. Bull Mar Sci Hockey PAR, Branch GM (1994)

Kaplan, David M

2006-01-01T23:59:59.000Z

288

CERTS Distributed Generation Test Bed Team  

E-Print Network (OSTI)

The electricity industry may well be standing at a technological threshold that leads to a new era built upon the most fundamental change in power systems engineering and organization since the original small isolated power networks of the nascent industry first began to be interconnected. The technical challenges, risks and rewards are all major and sobering. We hereby step across that threshold and accept the consequences.

Chris Marnay; Raquel Blanco; Kristina S. Hamachi; Cornelia P. Kawaan; Julie G. Osborn; F. Javier Rubio; Robert J. Yinger; Southern California Edison; Abbas A. Akhil; Ia National Laboratories

2000-01-01T23:59:59.000Z

289

MACCS2: An improved code for assessing nuclear accident consequences  

Science Conference Proceedings (OSTI)

The MACCS computer code was developed to predict probabilistic assessments of the consequences from severe accidents at nuclear power plants.For DOE applications and sensitivity studies of emergency response actions at nuclear power plants, MACCS2 represents a significant improvement in modeling flexibility over MACCS 1.5. This increased flexibility is obtained with an approximate doubling of the code`s run time and memory requirements. The software can be adapted to most computers. An executable is included in the code package for 386/486 IBM-compatible personal computers with 8 megabytes of random access memory (RAM). MACCS2 is being benchmarked against the RSAC-5 code developed by INEL. A new set of code documentation is being prepared that describes the use of the code, the models implemented, and the code benchmarking. Current plans are to have the code package (including source code) available to the public at the end of fiscal year 1994.

Chanin, D.I.; Banjac, V.; Miller, L.A. [Sandia National Lab., Albuquerque, NM (United States)

1994-12-31T23:59:59.000Z

290

Pebble-bed pebble motion: Simulation and Applications  

Science Conference Proceedings (OSTI)

Pebble bed reactors (PBR) have moving graphite fuel pebbles. This unique feature provides advantages, but also means that simulation of the reactor requires understanding the typical motion and location of the granular flow of pebbles. This report presents a method for simulation of motion of the pebbles in a PBR. A new mechanical motion simulator, PEBBLES, efficiently simulates the key elements of motion of the pebbles in a PBR. This model simulates gravitational force and contact forces including kinetic and true static friction. It's used for a variety of tasks including simulation of the effect of earthquakes on a PBR, calculation of packing fractions, Dancoff factors, pebble wear and the pebble force on the walls. The simulator includes a new differential static friction model for the varied geometries of PBRs. A new static friction benchmark was devised via analytically solving the mechanics equations to determine the minimum pebble-to-pebble friction and pebble-to-surface friction for a five pebble pyramid. This pyramid check as well as a comparison to the Janssen formula was used to test the new static friction equations. Because larger pebble bed simulations involve hundreds of thousands of pebbles and long periods of time, the PEBBLES code has been parallelized. PEBBLES runs on shared memory architectures and distributed memory architectures. For the shared memory architecture, the code uses a new O(n) lock-less parallel collision detection algorithm to determine which pebbles are likely to be in contact. The new collision detection algorithm improves on the traditional non-parallel O(n log(n)) collision detection algorithm. These features combine to form a fast parallel pebble motion simulation. The PEBBLES code provides new capabilities for understanding and optimizing PBRs. The PEBBLES code has provided the pebble motion data required to calculate the motion of pebbles during a simulated earthquake. The PEBBLES code provides the ability to determine the contact forces and the lengths of motion in contact. This information combined with the proper wear coefficients can be used to determine the dust production from mechanical wear. These new capabilities enhance the understanding of PBRs, and the capabilities of the code will allow future improvements in understanding.

Joshua J. Cogliati; Abderrafi M. Ougouag

2011-11-01T23:59:59.000Z

291

Liquid-fluidized-bed heat exchanger design parameters  

SciTech Connect

Liquid-fluidized-bed heat exchangers prevent scale accumulation on heat transfer surfaces and reduce the required heat transfer surface when scaling fluids, such as geothermal water, are used as the primary or working fluid. Liquid-fluidized-bed heat exchangers, principles of operation, and design parameters are described. Horizontal and vertical assemblies are discussed, including problems encountered with both designs. Bed-side heat transfer coefficients are given for limited cases, and a correlation is provided for calculating heat transfer coefficients for horizontal assemblies. A design example for a 60 kW/sub (e)/ (60 kW/sub (electric)/ preheater is included.

Allen, C.A.; Grimmett, E.S.

1978-04-01T23:59:59.000Z

292

Characterization of the Drag Force in an Air-Moderated Granular Bed  

E-Print Network (OSTI)

We measure the torque acting on a rod rotated perpendicular to its axis in a granular bed, through which an upflow of gas is utilized to tune the hydrostatic loading between grains. At low rotation rates the torque is independent of speed, but scales quadratically with rod-length and linearly with depth; the proportionality approaches zero linearly as the upflow of gas is increased towards a critical value above which the grains are fluidized. At high rotation rates the torque exhibits quadratic rate- dependence and scales as the rod's length to the 4th power. The torque has no dependence on either depth or airflow at these higher rates. A model used to describe the stopping force experienced by a projectile impacting a granular bed can be shown to predict these behaviors for our system's geometry, indicating that the same mechanics dictate both steady-state and transient drag forces in granular systems, regardless of geometry or material properties of the grains.

Theodore A Brzinski III; Douglas J Durian

2009-12-14T23:59:59.000Z

293

ADVANCED SORBENT DEVELOPMENT PROGRAM DEVELOPMENT OF SORBENTS FOR MOVING-BED AND FLUIDIZED-BED APPLICATIONS  

SciTech Connect

The integrated gasification combined cycle (IGCC) power system using high-temperature coal gas cleanup is one of the most promising advanced technologies for the production of electric power from coal in an environmentally acceptable manner. Unlike conventional low-temperature cleanup systems that require costly heat exchangers, high-temperature coal gas cleanup systems can be operated near 482-538 C (900-1000 F) or higher, conditions that are a closer match with the gasifier and turbine components in the IGCC system, thus resulting is a more efficient overall system. GE is developing a moving-bed, high-temperature desulfurization system for the IGCC power cycle in which zinc-based regenerable sorbents are currently being used as desulfurization sorbents. Zinc titanate and other proprietary zinc-based oxides are being considered as sorbents for use in the Clean Coal Technology Demonstration Program at Tampa Electric Co.'s (TECo) Polk Power Station. Under cold startup conditions at TECo, desulfurization and regeneration may be carried out at temperatures as low as 343 C (650 F), hence a versatile sorbent is desirable to perform over this wide temperature range. A key to success in the development of high-temperature desulfurization systems is the matching of sorbent properties for the selected process operating conditions, namely, sustainable desulfurization kinetics, high sulfur capacity, and mechanical durability over multiple cycles. Additionally, the sulfur species produced during regeneration of the sorbent must be in a form compatible with sulfur recovery systems, such as sulfuric acid or elemental sulfur processes. The overall objective of this program is to develop regenerable sorbents for hydrogen sulfide removal from coal-derived fuel gases in the temperature range 343-538 C (650-1000 F). Two categories of reactor configurations are being considered: moving-bed reactors and fluidized-bed (bubbling and circulating) reactors. In addition, a cost assessment and a market plan for large-scale fabrication of sorbents were developed. As an optional task, long-term bench-scale tests of the best moving-bed sorbents were conducted. Starting from thermodynamic calculations, several metal oxides were identified for potential use as hot gas cleanup sorbents using constructed phase stability diagrams and laboratory screening of various mixed-metal oxide formulations. Modified zinc titanates and other proprietary metal oxide formulations were evaluated at the bench scale and many of them found to be acceptable for operation in the target desulfurization temperature range of 370 C (700 F) to 538 C (1000 F) and regeneration temperatures up to 760 C (1400 F). Further work is still needed to reduce the batch-to-batch repeatability in the fabrication of modified zinc titanates for larger scale applications. The information presented in this Volume 1 report contains the results of moving-bed sorbent development at General Electric's Corporate Research and Development (GE-CRD). A separate Volume 2 report contains the results of the subcontract on fluidized-bed sorbent development at the Institute of Gas Technology (IGT).

R.E Ayala; V.S. Venkataramani; Javad Abbasian; Rachid B. Slimane; Brett E. Williams; Minoo K. Zarnegar; James R. Wangerow; Andy H. Hill

2000-03-31T23:59:59.000Z

294

ADVANCED SORBENT DEVELOPMENT PROGRAM; DEVELOPMENT OF SORBENTS FOR MOVING-BED AND FLUIDIZED-BED APPLICATIONS  

SciTech Connect

The integrated gasification combined cycle (IGCC) power system using high-temperature coal gas cleanup is one of the most promising advanced technologies for the production of electric power from coal in an environmentally acceptable manner. Unlike conventional low-temperature cleanup systems that require costly heat exchangers, high-temperature coal gas cleanup systems can be operated near 482-538 °C (900-1000 °F) or higher, conditions that are a closer match with the gasifier and turbine components in the IGCC system, thus resulting is a more efficient overall system. GE is developing a moving-bed, high-temperature desulfurization system for the IGCC power cycle in which zinc-based regenerable sorbents are currently being used as desulfurization sorbents. Zinc titanate and other proprietary zinc-based oxides are being considered as sorbents for use in the Clean Coal Technology Demonstration Program at Tampa Electric Co.?s (TECo) Polk Power Station. Under cold startup conditions at TECo, desulfurization and regeneration may be carried out at temperatures as low as 343 °C (650 °F), hence a versatile sorbent is desirable to perform over this wide temperature range. A key to success in the development of high-temperature desulfurization systems is the matching of sorbent properties for the selected process operating conditions, namely, sustainable desulfurization kinetics, high sulfur capacity, and mechanical durability over multiple cycles. Additionally, the sulfur species produced during regeneration of the sorbent must be in a form compatible with sulfur recovery systems, such as sulfuric acid or elemental sulfur processes. The overall objective of this program is to develop regenerable sorbents for hydrogen sulfide removal from coal-derived fuel gases in the temperature range 343-538 °C (650-1000 °F). Two categories of reactor configurations are being considered: moving-bed reactors and fluidized-bed (bubbling and circulating) reactors. In addition, a cost assessment and a market plan for large-scale fabrication of sorbents were developed. As an optional task, long-term bench-scale tests of the best moving-bed sorbents were conducted. Starting from thermodynamic calculations, several metal oxides were identified for potential use as hot gas cleanup sorbents using constructed phase stability diagrams and laboratory screening of various mixed-metal oxide formulations. Modified zinc titanates and other proprietary metal oxide formulations were evaluated at the bench scale and many of them found to be acceptable for operation in the target desulfurization temperature range of 370 °C (700 °F) to 538 °C (1000 °F) and regeneration tempera-tures up to 760 °C (1400 °F). Further work is still needed to reduce the batch-to-batch repeatability in the fabrication of modified zinc titanates for larger scale applications. The information presented in this Volume 1 report contains the results of moving-bed sorbent develop-ment at General Electric?s Corporate Research and Development (GE-CRD). A separate Volume 2 report contains the results of the subcontract on fluidized-bed sorbent development at the Institute of Gas Technology (IGT).

R.E. AYALA; V.S. VENKATARAMANI

1998-09-30T23:59:59.000Z

295

Apparatus for fixed bed coal gasification  

DOE Patents (OSTI)

An apparatus for fixed-bed coal gasification is described in which coal such as caking coal is continuously pyrolyzed with clump formation inhibited, by combining the coal with a combustible gas and an oxidant, and then continually feeding the pyrolyzed coal under pressure and elevated temperature into the gasification region of a pressure vessel. The materials in the pressure vessel are allowed to react with the gasifying agents in order to allow the carbon contents of the pyrolyzed coal to be completely oxidized. The combustion of gas produced from the combination of coal pyrolysis and gasification involves combining a combustible gas coal and an oxidant in a pyrolysis chamber and heating the components to a temperature of at least 1600.degree. F. The products of coal pyrolysis are dispersed from the pyrolyzer directly into the high temperature gasification region of a pressure vessel. Steam and air needed for gasification are introduced in the pressure vessel and the materials exiting the pyrolyzer flow down through the pressure vessel by gravity with sufficient residence time to allow any carbon to form carbon monoxide. Gas produced from these reactions are then released from the pressure vessel and ash is disposed of.

Sadowski, Richard S. (Greenville, SC)

1992-01-01T23:59:59.000Z

296

Coal bed methane global market potential  

Science Conference Proceedings (OSTI)

Worldwide increases in energy prices, as well as the increased potential for project financing derived from emissions credits, have renewed focus on coal bed methane (CBM) and coal mine methane (CMM) projects in coal-producing countries around the world. Globally, CBM utilization projects (in the operational, development, or planning stages) capture and utilize methane from gassy underground coal mines in at least 13 countries. The total methane emission reductions that could be achieved by these projects are approximately 135 billion cubic feet per year (equal to 14.8 million tons of carbon equivalent per year). This global activity level reflects a growing awareness of the technological practicality and the economic attractiveness of coal mine methane recovery and use. This report outlines the potential of the global CBM market. Contents: An overview of CBM; Challenges and issues; Technologies to generate power from CAM; Global CBM/CMM utilization; Country highlights; Ranking of countries with the largest CMM development potential (Australia, Canada, China, Germany, Mexico, Poland, Russia, Ukraine, United Kingdom, USA, Bulgaria, Czech Republic, France, India, Japan, Kazakhstan, South Africa); Planning CBM/CMM projects; Pre-feasibility and feasibility studies; Demonstration projects; Development plan and application process; Equity and debt; Carbon financing; Government sponsors; Private sponsors; Project risk reduction support; Examples of integrated project financing; Glossary.

Drazga, B. (ed.)

2007-01-16T23:59:59.000Z

297

Disposing of nuclear waste in a salt bed  

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

Disposing of nuclear waste in a salt bed Disposing of nuclear waste in a salt bed 1663 Los Alamos science and technology magazine Latest Issue:November 2013 All Issues » submit Disposing of nuclear waste in a salt bed Decades' worth of transuranic waste from Los Alamos is being laid to rest at the Waste Isolation Pilot Plant in southeastern New Mexico March 25, 2013 Disposing of nuclear waste in a salt bed Depending on the impurities embedded within it, the salt from WIPP can be anything from a reddish, relatively opaque rock to a clear crystal like the one shown here. Ordinary salt effectively seals transuranic waste in a long-term repository Transuranic waste, made of items such as lab coats and equipment that have been contaminated by radioactive elements heavier than uranium, is being shipped from the Los Alamos National Laboratory to a long-term storage

298

ANALYSIS OF METHANE PRODUCING COMMUNITIES WITHIN UNDERGROUND COAL BEDS  

E-Print Network (OSTI)

ANALYSIS OF METHANE PRODUCING COMMUNITIES WITHIN UNDERGROUND COAL BEDS by Elliott Paul Barnhart.........................................................................................8 Coal and Metabolite Enrichment Studies ..................................................................................14 Ability of the Consortium to Produce Methane from Coal and Metabolites ................16

Maxwell, Bruce D.

299

Electrical capacitance volume tomography (ECVT) applied to bubbling fluid beds  

SciTech Connect

These presentation visuals illustrate the apparatus and method for applying Electrical Capacitance Volume Tomography (ECVT) to bubbling fluid beds to their solid fraction and bubble properties. Results are compared to estimated values.

Weber, J., Mei, J.

2012-01-01T23:59:59.000Z

300

Shielded fluid stream injector for particle bed reactor  

DOE Patents (OSTI)

A shielded fluid-stream injector assembly is provided for particle bed reactors. The assembly includes a perforated pipe injector disposed across the particle bed region of the reactor and an inverted V-shaped shield placed over the pipe, overlapping it to prevent descending particles from coming into direct contact with the pipe. The pipe and shield are fixedly secured at one end to the reactor wall and slidably secured at the other end to compensate for thermal expansion. An axially extending housing aligned with the pipe and outside the reactor and an inline reamer are provided for removing deposits from the inside of the pipe. The assembly enables fluid streams to be injected and distributed uniformly into the particle bed with minimized clogging of injector ports. The same design may also be used for extraction of fluid streams from particle bed reactors.

Notestein, J.E.

1991-12-31T23:59:59.000Z

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


301

Community-Based Energy Development (C-BED) Tariff  

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

Under the Community-Based Energy Development (C-BED) Tariff, each public utility in Minnesota is required to file with the state Public Utilities Commission (PUC) to create a 20-year power purchase...

302

Coal Bed Methane Protection Act (Montana) | Open Energy Information  

Open Energy Info (EERE)

Data Page Edit with form History Share this page on Facebook icon Twitter icon Coal Bed Methane Protection Act (Montana) This is the approved revision of this page, as...

303

SUPPORTING CALCULATIONS FOR SUBMERGED BED SCRUBBER CONDENSATE DISPOSAL PRECONCEPTUAL STUDY  

Science Conference Proceedings (OSTI)

This document provides supporting calculations for the preparation of the Submerged Bed Scrubber Condensate Disposal Pre conceptual Study report The supporting calculations include equipment sizing, Hazard Category determination, and LAW Melter Decontamination Factor Adjustments.

PAJUNEN AL; TEDESCHI AR

2012-09-18T23:59:59.000Z

304

SLAC National Accelerator Laboratory - New Test Bed Probes the...  

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

New Test Bed Probes the Origin of Pulses at LCLS By Glenn Roberts Jr. July 23, 2013 It all comes down to one tiny spot on a diamond-cut, highly pure copper plate. That's where...

305

USE OF SORBENT BEDS FOR TRANSFERRING HYDROGEN GASES  

DOE Green Energy (OSTI)

The use of uranium or palladium black beds for transferring hydrogen isotopes has been described. Such beds react quantitatively and rapidly with hydrogen and its isotopes, store large volumes of gas as the solid hydride, and can evolve the gas in a controlled manner to give any reasonable pressure. The uranium bed is somewhat simpler to operate since only heat need be supplied to carry out the pumping cycle, while the palladium must be cooled to approximately - -100 deg C to sorb hydrogen and heated to evolve the gas. The palladium bed is very dependable in operation; it is poisoned only by gases like H/xub 2/S and CO and, if poisoned, can be easily reactivated. Uranium is rather easily poisoned by small amounts of air; cycling in hydrogen will reactivate the uncombined uranium but the portion reacted with air will be permanently combined. (auth)

Ahmann, D.H.; Flint, P.S.; Salmon, O.N.

1954-06-17T23:59:59.000Z

306

Hanford Low Activity Waste (LAW) Fluidized Bed Steam Reformer...  

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

Hanford Low Activity Waste (LAW) Fluidized Bed Steam Reformer (FBSR) Na-Al-Si (NAS) Waste Form Qualification C.M. Jantzen and E.M. Pierce November 18, 2010 2 Participating...

307

Supporting Calculations For Submerged Bed Scrubber Condensate Disposal Preconceptual Study  

SciTech Connect

This document provides supporting calculations for the preparation of the Submerged Bed Scrubber Condensate Disposal Preconceptual Study report The supporting calculations include equipment sizing, Hazard Category determination, and LAW Melter Decontamination Factor Adjustments.

Pajunen, A. J.; Tedeschi, A. R.

2012-09-18T23:59:59.000Z

308

PERSPECTIVES ON A DOE CONSEQUENCE INPUTS FOR ACCIDENT ANALYSIS APPLICATIONS  

Science Conference Proceedings (OSTI)

Department of Energy (DOE) accident analysis for establishing the required control sets for nuclear facility safety applies a series of simplifying, reasonably conservative assumptions regarding inputs and methodologies for quantifying dose consequences. Most of the analytical practices are conservative, have a technical basis, and are based on regulatory precedent. However, others are judgmental and based on older understanding of phenomenology. The latter type of practices can be found in modeling hypothetical releases into the atmosphere and the subsequent exposure. Often the judgments applied are not based on current technical understanding but on work that has been superseded. The objective of this paper is to review the technical basis for the major inputs and assumptions in the quantification of consequence estimates supporting DOE accident analysis, and to identify those that could be reassessed in light of current understanding of atmospheric dispersion and radiological exposure. Inputs and assumptions of interest include: Meteorological data basis; Breathing rate; and Inhalation dose conversion factor. A simple dose calculation is provided to show the relative difference achieved by improving the technical bases.

(NOEMAIL), K; Jonathan Lowrie, J; David Thoman (NOEMAIL), D; Austin Keller (NOEMAIL), A

2008-07-30T23:59:59.000Z

309

Consequences of Strong Compression in Tidal Disruption Events  

E-Print Network (OSTI)

The tidal disruption of a star by a supermassive black hole (SMBH) is a highly energetic event with consequences dependent on the degree to which the star plunges inside the SMBH's tidal sphere. We introduce a new analytic model for tidal disruption events (TDEs) to analyze the dependence of these events on beta, the ratio of the tidal radius to the orbital pericenter. We find, contrary to most previous work, that the spread in debris energy for a TDE is largely constant for all beta. This result has important consequences for optical transient searches targeting TDEs, which we discuss. We quantify leading-order general relativistic corrections to this spread in energy and find that they are small. We also examine the role of stellar spin, and find that a combination of spin-orbit misalignment, rapid rotation, and high beta may increase the spread in debris energy. Finally, we quantify for the first time the gravitational wave emission due to the strong compression of a star in a high-beta TDE. Although this signal is unlikely to be detectable for disruptions of main sequence stars, the tidal disruption of a white dwarf by an intermediate mass black hole can produce a strong signal visible to Advanced LIGO at tens of megaparsecs.

Nicholas Stone; Re'em Sari; Abraham Loeb

2012-10-11T23:59:59.000Z

310

Shock-Induced Flows through Packed Beds: Transient Regimes  

E-Print Network (OSTI)

The early stage of the transient regimes in the shock-induced flows within solid-packed beds are investigated in the linear longwave and high-frequency approximation. The transient resistance law is refined as the Duhameltime integral that follows from the general concept of dynamic tortuosity and compressibility of the packed beds. A closed-form solution is expected to describe accurately the early stage of the transient regime flow and is in qualitative agreement with available experimental data.

Yuri M. Shtemler; Isaac R. Shreiber; Alex Britan

2007-10-15T23:59:59.000Z

311

Fluidized bed combustor and coal gun-tube assembly therefor  

DOE Patents (OSTI)

A coal supply gun assembly for a fluidized bed combustor which includes heat exchange elements extending above the bed's distributor plate assembly and in which the gun's nozzles are disposed relative to the heat exchange elements to only discharge granular coal material between adjacent heat exchange elements and in a path which is substantially equidistant from adjacent heat exchange elements.

Hosek, William S. (Mt. Tabor, NJ); Garruto, Edward J. (Wayne, NJ)

1984-01-01T23:59:59.000Z

312

Experimental Research of Sleeping Bed Integrated with PCM Heat Storage and Solar Heating  

Science Conference Proceedings (OSTI)

This paper puts forward a new way of using solar energy and Phase Change Material (PCM): the integration of PCM, sleeping bed and solar energy. The cavity of sleeping bed is filled with PCM. The sleeping bed is a heat storage device charged by solar ... Keywords: Solar heating, Sleeping bed, PCM heat storage

Guoqing Yu; Ji Qiang; Huizhong Zhao; Zonghu Lv

2009-10-01T23:59:59.000Z

313

On the superficial gas velocity in deep gas-solids fluidized beds  

SciTech Connect

The superficial gas velocity is one of the key parameters used to determine the flow hydrodynamics in gas–solids fluidized beds. However, the superficial velocity varies with height in practice, and there is no consistent basis for its specification. Different approaches to determine the superficial gas velocity in a deep gas–solids system are shown to cause difficulties in developing models and in comparing predictions with experimental results. In addition, the reference conditions for superficial gas velocity are important in modeling of deep gas–solids systems where there is a considerable pressure drop.

Li, Tingwen; Grace, John; Shadle, Lawrence; Guenther, Chris

2012-11-15T23:59:59.000Z

314

On the Superficial Gas Velocity in Deep Gas-Solid Fluidized Beds  

Science Conference Proceedings (OSTI)

The superficial gas velocity is one of the key parameters used to determine the flow hydrodynamics in gas–solids fluidized beds. However, the superficial velocity varies with height in practice, and there is no consistent basis for its specification. Different approaches to determine the superficial gas velocity in a deep gas–solids system are shown to cause difficulties in developing models and in comparing predictions with experimental results. In addition, the reference conditions for superficial gas velocity are important in modeling of deep gas–solids systems where there is a considerable pressure drop.

Li, Tingwen; Grace, John; Shadle, Lawrence; Guenther, Chris

2011-11-15T23:59:59.000Z

315

Development and applications of clean coal fluidized bed technology  

SciTech Connect

Power generation in Europe and elsewhere relies heavily on coal and coal-based fuels as the source of energy. The reliance will increase in the future due to the decreasing stability of price and security of oil supply. In other words, the studies on fluidized bed combustion systems, which is one of the clean coal technologies, will maintain its importance. The main objective of the present study is to introduce the development and the applications of the fluidized bed technology (FBT) and to review the fluidized bed combustion studies conducted in Turkey. The industrial applications of the fluidized bed technology in the country date back to the 1980s. Since then, the number of the fluidized bed boilers has increased. The majority of the installations are in the textile sector. In Turkey, there is also a circulating fluidized bed thermal power plant with a capacity of 2 x 160 MW under construction at Can in Canakkale. It is expected that the FBT has had, or will have, a significant and increasing role in dictating the energy strategies for Turkey.

Eskin, N.; Hepbasli, A. [Ege University, Izmir (Turkey). Faculty of Engineering

2006-09-15T23:59:59.000Z

316

Ash level meter for a fixed-bed coal gasifier  

DOE Patents (OSTI)

An ash level meter for a fixed-bed coal gasifier is provided which utilizes the known ash level temperature profile to monitor the ash bed level. A bed stirrer which travels up and down through the extent of the bed ash level is modified by installing thermocouples to measure the bed temperature as the stirrer travels through the stirring cycle. The temperature measurement signals are transmitted to an electronic signal process system by an FM/FM telemetry system. The processing system uses the temperature signals together with an analog stirrer position signal, taken from a position transducer disposed to measure the stirrer position to compute the vertical location of the ash zone upper boundary. The circuit determines the fraction of each total stirrer cycle time the stirrer-derived bed temperature is below a selected set point, multiplies this fraction by the average stirrer signal level, multiplies this result by an appropriate constant and adds another constant such that a 1 to 5 volt signal from the processor corresponds to a 0 to 30 inch span of the ash upper boundary level. Three individual counters in the processor store clock counts that are representative of: (1) the time the stirrer temperature is below the set point (500.degree. F.), (2) the time duration of the corresponding stirrer travel cycle, and (3) the corresponding average stirrer vertical position. The inputs to all three counters are disconnected during any period that the stirrer is stopped, eliminating corruption of the measurement by stirrer stoppage.

Fasching, George E. (Morgantown, WV)

1984-01-01T23:59:59.000Z

317

Tanning bed use, deviance regulation theory, and source factors  

E-Print Network (OSTI)

Tanning bed use, especially among young, white females, has become a serious health problem in the United States. Those who use tanning beds value a tanned appearance; thus, one possible way to get individuals to stop using tanning beds is to persuade them to begin using an alternative method: a sunless tanner. This study sought to use persuasive messages to encourage individuals to both stop using tanning beds and start using a sunless tanner. Deviance Regulation Theory (DRT) was used to design three messages, and source expertise was manipulated (high and low). In addition, attitudes, perceived norms, benefits and threats about tanning were examined. Results indicate that the combination of DRT message design and source expertise produced several message conditions that were effective at decreasing tanning bed use intent. No combined message condition was effective at changing sunless tanner use intent. DRT message design alone did not produce results, nor did source expertise. Tanning attitudes were influenced by reference groups, and perceived norms about tanning predicted individual‘s tanning bed use for several reference groups. In addition, there was an interaction between benefits and threats of tanning.

Head, Katharine J.

2008-12-01T23:59:59.000Z

318

Robust techniques for developing empirical models of fluidized bed combustors  

E-Print Network (OSTI)

This report is designed to provide a review of those data analysis techniques that are most useful for fitting m-dimensional empirical surfaces to very large sets of data. One issue explored is the improvement

Gruhl, Jim

319

Development of a Simulation Model for Fluidized Bed Mild Gasifier.  

E-Print Network (OSTI)

?? A mild gasification method has been developed to provide an innovative clean coal technology. The objective of this study is to developed a numerical… (more)

Mazumder, AKM Monayem Hossain

2010-01-01T23:59:59.000Z

320

Method of burning sulfur-containing fuels in a fluidized bed boiler  

DOE Patents (OSTI)

A method of burning a sulfur-containing fuel in a fluidized bed of sulfur oxide sorbent wherein the overall utilization of sulfur oxide sorbent is increased by comminuting the bed drain solids to a smaller average particle size, preferably on the order of 50 microns, and reinjecting the comminuted bed drain solids into the bed. In comminuting the bed drain solids, particles of spent sulfur sorbent contained therein are fractured thereby exposing unreacted sorbent surface. Upon reinjecting the comminuted bed drain solids into the bed, the newly-exposed unreacted sorbent surface is available for sulfur oxide sorption, thereby increasing overall sorbent utilization.

Jones, Brian C. (Windsor, CT)

1982-01-01T23:59:59.000Z

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321

PRECLOSURE CONSEQUENCE ANALYSES FOR LICENSE APPLICATION  

Science Conference Proceedings (OSTI)

Radiological consequence analyses are performed for potential releases from normal operations in surface and subsurface facilities and from Category 1 and Category 2 event sequences during the preclosure period. Surface releases from normal repository operations are primarily from radionuclides released from opening a transportation cask during dry transfer operations of spent nuclear fuel (SNF) in Dry Transfer Facility 1 (DTF 1), Dry Transfer Facility 2 (DTF 2), the Canister Handling facility (CHF), or the Fuel Handling Facility (FHF). Subsurface releases from normal repository operations are from resuspension of waste package surface contamination and neutron activation of ventilated air and silica dust from host rock in the emplacement drifts. The purpose of this calculation is to demonstrate that the preclosure performance objectives, specified in 10 CFR 63.111(a) and 10 CFR 63.111(b), have been met for the proposed design and operations in the geologic repository operations area. Preclosure performance objectives are discussed in Section 6.2.3 and are summarized in Tables 1 and 2.

S. Tsai

2005-01-12T23:59:59.000Z

322

Opponent modeling in poker  

Science Conference Proceedings (OSTI)

Poker is an interesting test-bed for artificial intelligence research. It is a game of imperfect knowledge, where multiple competing agents must deal with risk management, agent modeling, unreliable information and deception, much like decision-making ...

Darse Billings; Denis Papp; Jonathan Schaeffer; Duane Szafron

1998-07-01T23:59:59.000Z

323

The Role of the Consequence Management Home Team in the Fukushima Daiichi Response  

Science Conference Proceedings (OSTI)

The Consequence Management Home Team is a U.S. Department of Energy/National Nuclear Security Administration asset. It assists a variety of response organizations with modeling; radiological operations planning; field monitoring techniques; and the analysis, interpretation, and distribution of radiological data. These reach-back capabilities are activated quickly to support public safety and minimize the social and economic impact of a nuclear or radiological incident. In the Fukushima Daiichi response, the Consequence Management Home Team grew to include a more broad range of support than was historically planned. From the early days of the response to the continuing involvement in supporting late phase efforts, each stage of the Consequence Management Home Team support had distinct characteristics in terms of management of incoming data streams as well as creation of products. Regardless of stage, the Consequence Management Home Team played a critical role in the Fukushima Daiichi response effort.

Pemberton, W., Mena, R., Beal, W.

2012-05-01T23:59:59.000Z

324

Modular Pebble Bed Reactor Project, University Research Consortium Annual Report  

Science Conference Proceedings (OSTI)

This project is developing a fundamental conceptual design for a gas-cooled, modular, pebble bed reactor. Key technology areas associated with this design are being investigated which intend to address issues concerning fuel performance, safety, core neutronics and proliferation resistance, economics and waste disposal. Research has been initiated in the following areas: · Improved fuel particle performance · Reactor physics · Economics · Proliferation resistance · Power conversion system modeling · Safety analysis · Regulatory and licensing strategy Recent accomplishments include: · Developed four conceptual models for fuel particle failures that are currently being evaluated by a series of ABAQUS analyses. Analytical fits to the results are being performed over a range of important parameters using statistical/factorial tools. The fits will be used in a Monte Carlo fuel performance code, which is under development. · A fracture mechanics approach has been used to develop a failure probability model for the fuel particle, which has resulted in significant improvement over earlier models. · Investigation of fuel particle physio-chemical behavior has been initiated which includes the development of a fission gas release model, particle temperature distributions, internal particle pressure, migration of fission products, and chemical attack of fuel particle layers. · A balance of plant, steady-state thermal hydraulics model has been developed to represent all major components of a MPBR. Component models are being refined to accurately reflect transient performance. · A comparison between air and helium for use in the energy-conversion cycle of the MPBR has been completed and formed the basis of a master’s degree thesis. · Safety issues associated with air ingress are being evaluated. · Post shutdown, reactor heat removal characteristics are being evaluated by the Heating-7 code. · PEBBED, a fast deterministic neutronic code package suitable for numerous repetitive calculations has been developed. Use of the code has focused on scoping studies for MPBR design features and proliferation issues. Publication of an archival journal article covering this work is being prepared. · Detailed gas reactor physics calculations have also been performed with the MCNP and VSOP codes. Furthermore, studies on the proliferation resistance of the MPBR fuel cycle has been initiated using these code · Issues identified during the MPBR research has resulted in a NERI proposal dealing with turbo-machinery design being approved for funding beginning in FY01. Two other NERI proposals, dealing with the development of a burnup “meter” and modularization techniques, were also funded in which the MIT team will be a participant. · A South African MPBR fuel testing proposal is pending ($7.0M over nine years).

Petti, David Andrew

2000-07-01T23:59:59.000Z

325

Atmospheric fluidized-bed combustion performance guidelines  

SciTech Connect

Performance specifications for conventional coal-fired boilers typically call for tests to be conducted in accordance with the ASME Performance Test Code for Steam Generating Units, PTC 4.1. The Code establishes procedures for conducting performance tests primarily to determine efficiency and capacity. The current edition of the PTC 4.1 is not entirely applicable to atmospheric fluidized-bed combustion boilers, however. AFBC boilers typically are equipped with integral sulfur capture through the addition of a sorbent material along with the fuel feed to the combustor, and this new technology introduces heat losses and credits that are not described in PTC 4.1. These heat losses and credits include combustion heat loss due to the calcination of the sorbent, heat credit due to sulfation, and the effects of calcination and sulfation on the dry flue gas flow, all of which significantly affect boiler efficiency calculations. The limitations of the current issue of the PTC 4.1 is recognized and the Code is now being reviewed to include heat losses and credits common to AFBC boilers. While this work will take some time, there is an immediate need for procedures for performance testing of AFBC boilers. These Guidelines are prepared to meet that need in the interim. The Guidelines detail procedures for boiler efficiency tests. They introduce technical and economic issues that may influence the test level of detail and accuracy. Methods of identifying required measurements, selection of measurement schemes, and assessment of measured versus estimated values are presented. A case study is used to illustrate the procedures and indicate which are the major credits and losses in the efficiency of a typical AFBC boiler. 6 figs., 8 tabs.

Sotelo, E. (Sotelo (Ernest), Berkeley, CA (USA))

1991-03-01T23:59:59.000Z

326

Advanced Core Design And Fuel Management For Pebble-Bed Reactors  

Science Conference Proceedings (OSTI)

A method for designing and optimizing recirculating pebble-bed reactor cores is presented. At the heart of the method is a new reactor physics computer code, PEBBED, which accurately and efficiently computes the neutronic and material properties of the asymptotic (equilibrium) fuel cycle. This core state is shown to be unique for a given core geometry, power level, discharge burnup, and fuel circulation policy. Fuel circulation in the pebble-bed can be described in terms of a few well?defined parameters and expressed as a recirculation matrix. The implementation of a few heat?transfer relations suitable for high-temperature gas-cooled reactors allows for the rapid estimation of thermal properties critical for safe operation. Thus, modeling and design optimization of a given pebble-bed core can be performed quickly and efficiently via the manipulation of a limited number key parameters. Automation of the optimization process is achieved by manipulation of these parameters using a genetic algorithm. The end result is an economical, passively safe, proliferation-resistant nuclear power plant.

Hans D. Gougar; Abderrafi M. Ougouag; William K. Terry

2004-10-01T23:59:59.000Z

327

Two stage, low temperature, catalyzed fluidized bed incineration with in situ neutralization for radioactive mixed wastes  

Science Conference Proceedings (OSTI)

A two stage, low temperature, catalyzed fluidized bed incineration process is proving successful at incinerating hazardous wastes containing nuclear material. The process operates at 550{degrees}C and 650{degrees}C in its two stages. Acid gas neutralization takes place in situ using sodium carbonate as a sorbent in the first stage bed. The feed material to the incinerator is hazardous waste-as defined by the Resource Conservation and Recovery Act-mixed with radioactive materials. The radioactive materials are plutonium, uranium, and americium that are byproducts of nuclear weapons production. Despite its low temperature operation, this system successfully destroyed poly-chlorinated biphenyls at a 99.99992% destruction and removal efficiency. Radionuclides and volatile heavy metals leave the fluidized beds and enter the air pollution control system in minimal amounts. Recently collected modeling and experimental data show the process minimizes dioxin and furan production. The report also discusses air pollution, ash solidification, and other data collected from pilot- and demonstration-scale testing. The testing took place at Rocky Flats Environmental Technology Site, a US Department of Energy facility, in the 1970s, 1980s, and 1990s.

Wade, J.F.; Williams, P.M.

1995-05-17T23:59:59.000Z

328

The development of an integrated multistaged fluid bed retorting process. Annual report, October 1991--September 1992  

SciTech Connect

This report summarizes the progress made on the development of an integrated multistage fluidized bed retorting process (KENTORT II) during the period of October 1, 1991 through September 30, 1992. The KENTORT II process includes integral fluidized bed zones for pyrolysis (shale oil production), gasification (synthesis gas production), and combustion of the spent oil shale for process heat. The purpose of this program is to design and test the KENTORT II process at the 50-lb/hr scale. The work completed this year involved several different areas. Basic studies of the cracking and coking kinetics of shale oil vapors were carried out in fluidized and fixed bed reactors using both freshly generated shale oil vapors and model compounds. The design and fabrication of the 50-lb/hr KENTORT II reactor was completed and installation of the process components was initiated. The raw oil shale sample (Cleveland Member from Montgomery County, Kentucky) for the program was mined, prepared, characterized and stored. A preliminary study of KENTORT II-derived oil for possible paving applications was completed, and it was concluded that the shale exhibits acceptable properties as an asphalt recycling agent.

Carter, S.; Vego, A.; Stehn, J.; Taulbee, D.; Robl, T.; Hower, J.; Mahboub, K.; Robertson, R.; Hornsberger, P.; Oduroh, P.; Simpson, A.

1992-12-01T23:59:59.000Z

329

Development of topping combustor for advanced concept pressurized fluidized-bed combustion  

SciTech Connect

The objective of this program is to develop a topping combustor to operate in a Second-Generation Pressurized Fluidized Bed (PFBC) Combined Cycle power generation system. The combustor must be able to: lightoff with a high heating value fuel and compressor discharge air to heat the fluidized bed(s) and provide power for PFBC and carbonizer off-line; operate with 1,600 F oxygen depleted air from the PFBC and high heating value fuel to handle carbonizer off-line conditions; ramp up to 100% carbonizer syngas firing (normal operation) by firing a blend of decreasing high heating value fuel and increasing low heating value syngas; utilize the vitiated air, at temperatures up to 1,600 F for as much cooling of the metal combustor as possible, thus minimizing the compressor bypass air needed for combustor cooling; provide an acceptance exit temperature pattern at the desired burner outlet temperature (BOT); minimize the conversion of fuel bound nitrogen (FBN) present in the syngas to NO{sub x}; and have acceptably high combustion efficiency, and low emissions of carbon monoxide, UHC, etc. This paper reports the results of tests of a 14 inch diameter topping combustor with a modified fuel-rich zone conducted in June 1993, design of an 18 inch diameter topping combustor to be tested in June 1994 and afterwards, and results of a 50% scale cold flow model which has been built and tested.

Domeracki, W.F.; Dowdy, T.E.; Bachovchin, D.

1994-10-01T23:59:59.000Z

330

Applications of Highly Cross Linked Mixed Bed Ion Exchange Resins in Biodiesel Processing  

E-Print Network (OSTI)

Biofuels are a promising solution to society's quest for sustainable energy. In the transportation sector, biodiesel is the leading alternative diesel fuel currently in use today. However, the current global and domestic production of biodiesel is far below the petro-diesel consumption and demand. To increase the availability of biodiesel in the market, new methods of biodiesel production must be developed to take advantage of the plentiful low quality waste derived feed stocks that currently present problems to biodiesel production using conventional methods. This research presents one new approach based upon using heterogeneous highly cross linked mixed bed solid phase catalysts to facilitate the production of biodiesel from feed stocks with high concentrations of free fatty acids (FFA). The performance of the heterogeneous mixed bed catalysts method developed in this research was evaluated and optimized for catalyst concentration and reaction duration while the mixing rate, reaction temperature, initial FFA composition of the feed stock and the alcohol-to-oil molar ratio were kept constant. The presented method reduces the FFA content of the starting feed stock while limiting the release of water into the reaction. Through experimentation, it was found that FFA removal with the mixed bed resin is due to ion exchange with the quaternary ammonium functional group and not catalysis to form esters. A model describing the heterogeneous processing method is presented. The outcome of this research is the development of a new processing method that can be used to create biodiesel from poor quality raw feed stock materials.

Jamal, Yousuf

2009-08-01T23:59:59.000Z

331

Some consequences of the Majoron being the dark radiation  

E-Print Network (OSTI)

We discuss some phenomenological consequences in a scenario where a singlet Majoron plays the role of dark radiation. We study the interrelations between neutrino mass generation and the scalar potential arising from this identification. We find the extra scalar has to be light with a mass at or below the GeV level. The mixing of this scalar with the Standard Model Higgs impacts low energy phenomena such as the muonic hydrogen Lamb shift and muon anomalous magnetic moment. Demanding that the light scalar solves the puzzle in the muon magnetic moment requires the scalar to be lighter still with mass at or below the 10 MeV level. The cross-sections for the production of heavy neutrinos at LHC14 are also given.

We-Fu Chang; John N. Ng; Jackson M. S. Wu

2013-10-24T23:59:59.000Z

332

Hydrogen Trailer Storage Facility (Building 878). Consequence analysis  

DOE Green Energy (OSTI)

The Department of Energy Order 5500.3A requires facility-specific hazards assessments be prepared, maintained, and used for emergency planning purposes. This consequence analysis documents the impact that a hydrogen accident could have to employees, the general public, and nearby facilities. The computer model ARCHIE was utilized to determine discharge rates, toxic vapor dispersion analyses, flammable vapor cloud hazards, explosion hazards, and flame jets for the Hydrogen Trailer Storage Facility located at Building 878. To determine over pressurization effects, hand calculations derived from the Department of the Air Force Manual, ``Structures to Resist the Effects of Accidental Explosions,`` were utilized. The greatest distances at which a postulated facility event will produce the Lower Flammability and the Lower Detonation Levels are 1,721 feet and 882 feet, respectively. The greatest distance at which 10.0 psi overpressure (i.e., total building destruction) is reached is 153 feet.

Banda, Z.; Wood, C.L.

1994-12-01T23:59:59.000Z

333

Petrology and geochemistry of samples from bed-contact zones in Tunnel Bed 5, U12g-Tunnel, Nevada Test Site  

Science Conference Proceedings (OSTI)

This report summarizes the detailed geologic characterization of samples of bed-contact zones and surrounding nonwelded bedded tuffs, both within Tunnel Bed 5, that are exposed in the G-Tunnel complex beneath Rainier Mesa on the Nevada Test Site (NTS). Original planning studies treated the bed-contact zones in Tunnel Bed 5 as simple planar surfaces of relatively high permeability. Detailed characterization, however, indicates that these zones have a finite thickness, are depositional in origin, vary considerably over short vertical and horizontal distances, and are internally complex. Fluid flow in a sequence of nonwelded zeolitized ash-flow or bedded tuffs and thin intervening reworked zones appears to be a porous-medium phenomenon, regardless of the presence of layering. There are no consistent differences in either bulk composition or detailed mineralogy between bedded tuffs and bed-contact zones in Tunnel Bed 5. Although the original bulk composition of Tunnel Bed 5 was probably peralkaline, extensive zeolitization has resulted in a present peraluminous bulk composition of both bedded tuffs and bed-contact zones. The major zeolite present, clinoptilolite, is intermediate (Ca:K:Na = 26:35:39) and effectively uniform in composition. This composition is similar to that of clinoptilolite from the tuffaceous beds of Calico Hills above the static water level in hole USW G-1, but somewhat different from that reported for zeolites from below the static water level in USW G-2. Tunnel Bed 5 also contains abundant hydrous manganese oxides. The similarity in composition of the clinoptilolites from Tunnel Bed 5 and those above the static water level at Yucca Mountain indicates that many of the results of nuclide-migration experiments in Tunnel Bed 5 would be transferrable to zeolitized nonwelded tuffs above the static water level at Yucca Mountain.

Connolly, J.R.; Keil, K.; Mansker, W.L.; Allen, C.C.; Husler, J.; Lowy, R.; Fortney, D.R.; Lappin, A.R.

1984-10-01T23:59:59.000Z

334

Design requirements for the supercritical water oxidation test bed  

SciTech Connect

This report describes the design requirements for the supercritical water oxidation (SCWO) test bed that will be located at the Idaho National Engineering Laboratory (INEL). The test bed will process a maximum of 50 gph of waste plus the required volume of cooling water. The test bed will evaluate the performance of a number of SCWO reactor designs. The goal of the project is to select a reactor that can be scaled up for use in a full-size waste treatment facility to process US Department of Energy mixed wastes. EG&G Idaho, Inc. will design and construct the SCWO test bed at the Water Reactor Research Test Facility (WRRTF), located in the northern region of the INEL. Private industry partners will develop and provide SCWO reactors to interface with the test bed. A number of reactor designs will be tested, including a transpiring wall, tube, and vessel-type reactor. The initial SCWO reactor evaluated will be a transpiring wall design. This design requirements report identifies parameters needed to proceed with preliminary and final design work for the SCWO test bed. A flow sheet and Process and Instrumentation Diagrams define the overall process and conditions of service and delineate equipment, piping, and instrumentation sizes and configuration Codes and standards that govern the safe engineering and design of systems and guidance that locates and interfaces test bed hardware are provided. Detailed technical requirements are addressed for design of piping, valves, instrumentation and control, vessels, tanks, pumps, electrical systems, and structural steel. The approach for conducting the preliminary and final designs and environmental and quality issues influencing the design are provided.

Svoboda, J.M.; Valentich, D.J.

1994-05-01T23:59:59.000Z

335

A fixed granular-bed sorber for measurement and control of alkali vapors in PFBC (pressurized fluidized-bed combustion)  

SciTech Connect

Alkali vapors (Na and K) in the hot flue gas from the pressurized fluidized-bed combustion (PFBC) of coal could cause corrosion problems with the gas turbine blades. In a laboratory-scale PFBC test with Beulah lignite, a fixed granular bed of activated bauxite sorbent was used to demonstrate its capability for measuring and controlling alkali vapors in the PFBC flue gas. The Beulah lignite was combusted in a bed of Tymochtee dolomite at bed temperatures ranging from 850 to 875{degrees}C and a system pressure of 9.2 atm absolute. The time-averaged concentration of sodium vapor in the PFBC flue gas was determined from the analysis of two identical beds of activated bauxite and found to be 1.42 and 1.50 ppmW. The potassium vapor concentration was determined to be 0.10 ppmW. The sodium material balance showed that only 0.24% of the total sodium in the lignite was released as vapor species in the PFBC flue gas. This results in an average of 1.56 ppmW alkali vapors in the PFBC flue gas. This average is more than 1.5 orders of magnitude greater than the currently suggested alkali specification limit of 0.024 ppm for an industrial gas turbine. The adsorption data obtained with the activated bauxite beds were also analyzed mathematically by use of a LUB (length of unused bed)/equilibrium section concept. Analytical results showed that the length of the bed, L{sub o} in centimeters, relates to the break through time, {theta}{sub b} in hours, for the alkali vapor to break through the bed as follows: L{sub o} = 33.02 + 1.99 {theta}{sub b}. This formula provides useful information for the engineering design of fixed-bed activated bauxite sorbers for the measurement and control of alkali vapors in PFBC flue gas. 26 refs., 4 figs., 4 tabs.

Lee, S.H.D.; Swift, W.M.

1990-01-01T23:59:59.000Z

336

Dispersal and fallout simulations for urban consequences management (u)  

SciTech Connect

Hazardous chemical, biological, or radioactive releases from leaks, spills, fires, or blasts, may occur (intentionally or accidentally) in urban environments during warfare or as part of terrorist attacks on military bases or other facilities. The associated contaminant dispersion is complex and semi-chaotic. Urban predictive simulation capabilities can have direct impact in many threat-reduction areas of interest, including, urban sensor placement and threat analysis, contaminant transport (CT) effects on surrounding civilian population (dosages, evacuation, shelter-in-place), education and training of rescue teams and services. Detailed simulations for the various processes involved are in principle possible, but generally not fast. Predicting urban airflow accompanied by CT presents extremely challenging requirements. Crucial technical issues include, simulating turbulent fluid and particulate transport, initial and boundary condition modeling incorporating a consistent stratified urban boundary layer with realistic wind fluctuations, and post-processing of the simulation results for practical consequences management. Relevant fluid dynamic processes to be simulated include, detailed energetic and contaminant sources, complex building vortex shedding and flows in recirculation zones, and modeling of particle distributions, including particulate fallout, as well as deposition, re-suspension and evaporation. Other issues include, modeling building damage effects due to eventual blasts, addressing appropriate regional and atmospheric data reduction.

Grinstein, Fernando F [Los Alamos National Laboratory; Wachtor, Adam J [Los Alamos National Laboratory; Nelson, Matt [Los Alamos National Laboratory; Brown, Michael [Los Alamos National Laboratory; Bos, Randy [Los Alamos National Laboratory; Patnik, Gopal [US NAVAL RESEARCH LAB.

2010-01-01T23:59:59.000Z

337

Moving granular-bed filter development program topical report  

SciTech Connect

The Westinghouse Science Technology Center has proposed a novel moving granular-bed filter concept, the Standleg Moving Granular-Bed Filter (S-MGBF) system, that overcomes the inherent deficiencies of the current state-of-the-art moving granular-bed filter technology. The S-MGBF system combines two unique features that make it highly effective for use in advanced coal-fueled power plants. First, the S-MGBF system applies pelletization technology to generate filter pellets from the power plant solid waste materials, and uses these pellets as a once-through'' filtering media to eliminate the need for costly, complex, and large filter media recycling equipment. This pelletizing step also generates a more environmentally acceptable solid waste product and provides the potential to incorporate gas-phase contaminant sorbents into the filtering media. Secondly, the S-MGBF system passes these pellets and the flyash laden power plant gas through a highly compact S-MGBF that uses cocurrent gas-pellet contacting in an arrangement that greatly simplifies and enhances the distribution of dirty gas to the moving bed and the disengagement of clean gas from the moving bed.

Newby, R.A.; Dilmore, W.J.; Fellers, A.W.; Gasparovic, A.C.; Kittle, W.F.; Lippert, T.E.; Smeltzer, E.E.; Yang, W.C.

1991-10-17T23:59:59.000Z

338

Applications of moving granular-bed filters to advanced systems  

SciTech Connect

The contract is arranged as a base contract with three options. The objective of the base contract is to develop conceptual design(s) of moving granular bed filter and ceramic candle filter technology for control of particles from integrated gasification combined cycle (IGCC) systems, pressurized fluidized-bed combustors (PFBC), and direct coal fueled turbine (DCFT) environments. The conceptual design(s) of these filter technologies are compared, primarily from an economic perspective. The granular bed filter was developed through low pressure, high temperature (1600{degree}F) testing in the late 1970`s and early 1980`s. Collection efficiencies over 99% were obtained. In 1988, high pressure, high temperature testing was completed at New York University, Westbury, N.Y., utilizing a two advanced power generating plants were chosen for developing conceptual designs and cost estimates of the commercial sized filters. One is the 450 MWe, second generation pressurized fluidized bed combustion plant defined by Foster Wheeler. This plant originally included cross-flow filters for hot gas cleanup. The other plant under study is a 100 MWe, KRW air blown gasifier. A cross-flow filter was utilized for gas stream cleanup in this study also. Granular bed and ceramic candle filters were substituted for the cross-flow filters in both these plants, and the resulting costs were compared.

Wilson, K.W.; Haas, J.C.; Eshelman, M.B.

1993-09-01T23:59:59.000Z

339

Determination of electrical resistivity of dry coke beds  

SciTech Connect

The electrical resistivity of the coke bed is of great importance when producing FeMn, SiMn, and FeCr in a submerged arc furnace. In these processes, a coke bed is situated below and around the electrode tip and consists of metallurgical coke, slag, gas, and metal droplets. Since the basic mechanisms determining the electrical resistivity of a coke bed is not yet fully understood, this investigation is focused on the resistivity of dry coke beds consisting of different carbonaceous materials, i.e., coke beds containing no slag or metal. A method that reliably compares the electrical bulk resistivity of different metallurgical cokes at 1500{sup o} C to 1600{sup o}C is developed. The apparatus is dimensioned for industrial sized materials, and the electrical resistivity of anthracite, charcoal, petroleum coke, and metallurgical coke has been measured. The resistivity at high temperatures of the Magnitogorsk coke, which has the highest resistivity of the metallurgical cokes investigated, is twice the resistivity of the Corus coke, which has the lowest electrical resistivity. Zdzieszowice and SSAB coke sort in between with decreasing resistivities in the respective order. The electrical resistivity of anthracite, charcoal, and petroleum coke is generally higher than the resistivity of the metallurgical cokes, ranging from about two to about eight times the resistivity of the Corus coke at 1450{sup o}C. The general trend is that the bulk resistivity of carbon materials decreases with increasing temperature and increasing particle size.

Eidem, P.A.; Tangstad, M.; Bakken, J.A. [NTNU, Trondheim (Norway)

2008-02-15T23:59:59.000Z

340

Numerical Analysis of the Dynamics of Two- and Three-Dimensional Fluidized Bed Reactors using an Euler-Lagrange Approach  

SciTech Connect

Biomass thermochemical conversion, often done in fluidized beds, recently gained a lot of attention due to its potential to efficiently produce renewable liquid fuels. Optimization of reactor design and operating conditions, however, requires a fundamental understanding of bed dynamics. In this work, a numerical framework based on an Euler-Lagrange approach is developed and used to perform and analyze large-scale simulations of two- and three-dimensional periodic fluidized beds. Collisions are handled using a soft-sphere model. An efficient parallel implementation allows one to explicitly track over 30 million particles, which is representative of the number of particles found in lab-scale reactor, therefore demonstrating the capability of Lagrangian approaches to simulate realistic systems at that scale. An on-the-fly bubble identification and tracking algorithm is used to characterize bubble dynamics for inlet velocities up to 9 times the minimum fluidization velocity. Statistics for gas volume fraction, gas and particle velocities, bed expansion, and bubble size and velocity, is compared across the two- and three-dimensional configurations, and comparison with literature data generally shows good agreement. The wide distribution of gas residence times observed in the simulations is linked to the different gas hold-up characteristics of the gas-solid system.

Pepiot, P.; Desjardins, O.

2012-04-01T23:59:59.000Z

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


341

Coal hydrogenation and deashing in ebullated bed catalytic reactor  

SciTech Connect

An improved process for hydrogenation of coal containing ash with agglomeration and removal of ash from an ebullated bed catalytic reactor to produce deashed hydrocarbon liquid and gas products. In the process, a flowable coal-oil slurry is reacted with hydrogen in an ebullated catalyst bed reaction zone at elevated temperature and pressure conditions. The upward velocity and viscosity of the reactor liquid are controlled so that a substantial portion of the ash released from the coal is agglomerated to form larger particles in the upper portion of the reactor above the catalyst bed, from which the agglomerated ash is separately withdrawn along with adhering reaction zone liquid. The resulting hydrogenated hydrocarbon effluent material product is phase separated to remove vapor fractions, after which any ash remaining in the liquid fraction can be removed to produce substantially ash-free coal-derived liquid products.

Huibers, Derk T. A. (Pennington, NJ); Johanson, Edwin S. (Princeton, NJ)

1983-01-01T23:59:59.000Z

342

DoD ESTCP Energy Test Bed Project  

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

ESTCP Energy Test Bed Project ESTCP Energy Test Bed Project EW-201016 "High Efficiency - Reduced Emissions Boiler Controls" 23 May 2012 Dr. Jim Galvin ESTCP Program Manager for Energy & Water ESTCP Energy Test Bed Project Location 2 3 Boiler Efficiency Improvement Demo Oxygen Sensor Servo Controls * 90% of boilers lack automated controls * State of the art automated controls sense only oxygen * Demonstrated prototype sensed oxygen and carbon monoxide Prototype CO Sensor Key Findings Boiler Before Demo 4 * Size: 25 MMBtu * Age: 30 years * Fuel: Natural Gas or Oil * Demo performed by United Technologies Research Center * Technology demonstrated: Fireye PPC4000 (Oxygen trim control) * Upgraded PPC4000 tested as a prototype 5 Three Phased Test ● Test Phase 1: Existing Legacy System (baseline)

343

Very High Temperature Reactor (VHTR) Deep Burn Core and Fuel Analysis -- Complete Design Selection for the Pebble Bed Reactor  

Science Conference Proceedings (OSTI)

The Deep-Burn (DB) concept focuses on the destruction of transuranic nuclides from used light water reactor fuel. These transuranic nuclides are incorporated into TRISO coated fuel particles and used in gas-cooled reactors with the aim of a fractional fuel burnup of 60 to 70% in fissions per initial metal atom (FIMA). This high performance is expected through the use of multiple recirculation passes of the fuel in pebble form without any physical or chemical changes between passes. In particular, the concept does not call for reprocessing of the fuel between passes. In principle, the DB pebble bed concept employs the same reactor designs as the presently envisioned low-enriched uranium core designs, such as the 400 MWth Pebble Bed Modular Reactor (PBMR-400). Although it has been shown in the previous Fiscal Year (2009) that a PuO2 fueled pebble bed reactor concept is viable, achieving a high fuel burnup, while remaining within safety-imposed prescribed operational limits for fuel temperature, power peaking and temperature reactivity feedback coefficients for the entire temperature range, is challenging. The presence of the isotopes 239-Pu, 240-Pu and 241-Pu that have resonances in the thermal energy range significantly modifies the neutron thermal energy spectrum as compared to a ”standard,” UO2-fueled core. Therefore, the DB pebble bed core exhibits a relatively hard neutron energy spectrum. However, regions within the pebble bed that are near the graphite reflectors experience a locally softer spectrum. This can lead to power and temperature peaking in these regions. Furthermore, a shift of the thermal energy spectrum with increasing temperature can lead to increased absorption in the resonances of the fissile Pu isotopes. This can lead to a positive temperature reactivity coefficient for the graphite moderator under certain operating conditions. The effort of this task in FY 2010 has focused on the optimization of the core to maximize the pebble discharge burnup level, while retaining its inherent safety characteristics. Using generic pebble bed reactor cores, this task will perform physics calculations to evaluate the capabilities of the pebble bed reactor to perform utilization and destruction of LWR used-fuel transuranics. The task will use established benchmarked models, and will introduce modeling advancements appropriate to the nature of the fuel considered (high TRU content and high burn-up).

B. Boer; A. M. Ougouag

2010-09-01T23:59:59.000Z

344

Training Program EOC0012 Consequence Assessment Team Training  

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

12 12 Consequence Assessment Team Training COURSE SYLLABUS Subject Category: Emergency Operations Schedule: N/A (online) Course Length: Approximately 1 hour Medical Approval: None Delivery Method: Online - offered through the Emergency Operations Training Academy (EOTA) http://eota.doeal.gov/ Location: N/A (online) Course Prerequisite: None Retraining/Recertification: Annually recommended Course Purpose: Designed as an orientation for members of the Emergency Operations Center (EOC) Consequence Assessment team who would be called upon to provide Hazard and Consequence and Meteorological data to assist in planning and response efforts. Course Objectives: The goal of this training is to serve as an orientation to consequence assessment. Students will identify the objectives

345

Quantifying the Air Pollution Exposure Consequences of Distributed...  

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

Quantifying the Air Pollution Exposure Consequences of Distributed Electricity Generation Speaker(s): Garvin Heath Date: November 8, 2005 - 12:00pm Location: Bldg. 90 This talk...

346

ADVISORY: NNSA Releases Pictures, Video of Consequence Management...  

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

Tuesday, March 15, 2011 ADVISORY: NNSA Releases Pictures, Video of Consequence Management Response Teams Deploying to Japan WASHINGTON, D.C. The National Nuclear Security...

347

Consequences of low dose irradiation in the CNS  

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

Consequences of low dose irradiation in the CNS Bertrand Tseng, Munjal M. Acharya, Neal Patel, Katherine Tran, Mary Lan, Erich Giedzinski, Vipan Kumar and Charles Limoli Department...

348

Molecular to fluid dynamics: The consequences of stochastic molecular motion Stefan Heinz*  

E-Print Network (OSTI)

Molecular to fluid dynamics: The consequences of stochastic molecular motion Stefan Heinz) The derivation of fluid dynamic equations from molecular equations is considered. This is done on the basis of a stochastic model for the molecular motion which can be obtained by a projection of underlying determin- istic

Heinz, Stefan

349

PMB-Waste: An analysis of fluidized bed thermal treatment  

SciTech Connect

A fluidized bed treatment process was evaluated for solid waste from plastic media blasting of aircraft protective coating. The treatment objective is to decompose and oxidize all organic components, and concentrate all the hazardous metals in the ash. The reduced volume and mass are expected to reduce disposal cost. A pilot test treatment was done in an existing fluidized bed equipped with emissions monitors, and emissions within regulatory requirements were demonstrated. A economic analysis of the process is inconclusive due to lack of reliable cost data of disposal without thermal treatment.

Gat, U.; Kass, M.D.; Lloyd, D.B.

1995-07-01T23:59:59.000Z

350

Advanced Circulating Pressurized Fluidized Bed Combustion (APFBC) Repowering Considerations  

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

Weinstein & Travers: APFBC Repowering Considerations Weinstein & Travers: APFBC Repowering Considerations paper 970563 Page 1 of 35 Advanced Circulating Pressurized Fluidized Bed Combustion (APFBC) Repowering Considerations Richard E. Weinstein, P.E. Parsons Power Group Inc. Reading, Pennsylvania eMail: Richard_E_Weinstein@Parsons.COM / phone: 610 / 855-2699 Robert W. Travers, P.E. U.S. Department of Energy Office of Fossil Energy Germantown, Maryland eMail: Robert.Travers@HQ.DOE.GOV / phone: 301 / 903-6166 Weinstein & Travers: APFBC Repowering Considerations paper 970563 Page 2 of 35 Advanced Circulating Pressurized Fluidized Bed Combustion Repowering Considerations ABSTRACT ..............................................................................................................................................................................

351

Coal-feeding mechanism for a fluidized bed combustion chamber  

SciTech Connect

The present invention is directed to a fuel-feeding mechanism for a fluidized bed combustor. In accordance with the present invention a perforated conveyor belt is utilized in place of the fixed grid normally disposed at the lower end of the fluidized bed combustion zone. The conveyor belt is fed with fuel, e.g. coal, at one end thereof so that the air passing through the perforations dislodges the coal from the belt and feeds the coal into the fluidized zone in a substantially uniform manner.

Gall, Robert L. (Morgantown, WV)

1981-01-01T23:59:59.000Z

352

Refractory experience in circulating fluidized bed combustors, Task 7  

Science Conference Proceedings (OSTI)

This report describes the results of an investigation into the status of the design and selection of refractory materials for coal-fueled circulating fluidized-bed combustors. The survey concentrated on operating units in the United States manufactured by six different boiler vendors: Babcock and Wilcox, Combustion Engineering, Foster Wheeler, Keeler Dorr-Oliver, Pyropower, and Riley Stoker. Information was obtained from the boiler vendors, refractory suppliers and installers, and the owners/operators of over forty units. This work is in support of DOE's Clean Coal Technology program, which includes circulating fluidized-bed technology as one of the selected concepts being evaluated.

Vincent, R.Q.

1989-11-01T23:59:59.000Z

353

Regeneration of lime from sulfates for fluidized-bed combustion  

DOE Patents (OSTI)

In a fluidized-bed combustor the evolving sulfur oxides are reacted with CaO to form calcium sulfate which is then decomposed in the presence of carbonaceous material, such as the fly ash recovered from the combustion, at temperatures of about 900.degree. to 1000.degree. C., to regenerate lime. The regenerated lime is then recycled to the fluidized bed combustor to further react with the evolving sulfur oxides. The lime regenerated in this manner is quite effective in removing the sulfur oxides.

Yang, Ralph T. (Middle Island, NY); Steinberg, Meyer (Huntington Station, NY)

1980-01-01T23:59:59.000Z

354

The fluidized bed combustor-heater equipped gas fired CCGT  

Science Conference Proceedings (OSTI)

The combustion of natural gas in an atmospheric fluidized bed combined with heat transfer from the bed to the working fluid is shown to be an attractive means for supplying heat to closed cycle gas turbines. It is demonstrated how this concept can yield high thermal efficiencies without the use of high temperature resistant materials and yield low levels of pollutant emissions. The features of the combustor-heater are established for a 9000 kW closed cycle gas turbine generator and comparisons are made with a conventional open cycle machine.

Fejer, A.

1984-06-01T23:59:59.000Z

355

Fluidized bed combustor-heater equipped gas fired CCGT  

Science Conference Proceedings (OSTI)

The combustion of natural gas in an atmospheric fluidized bed combined with heat transfer from the bed to the working fluid is shown to be an attractive means for supplying heat to closed cycle gas turbines. It is demonstrated how this concept can yield high thermal efficiencies without the use of high temperature resistant materials and yield low levels of pollutant emissions. The features of the combustor-heater are established for a 9000 kW closed cycle gas turbine generator and comparisons are made with a conventional open cycle machine.

Fejer, A.A.

1984-01-01T23:59:59.000Z

356

Pressurized fluidized-bed combustion technology exchange workshop  

SciTech Connect

The pressurized fluidized-bed combustion technology exchange workshop was held June 5 and 6, 1979, at The Meadowlands Hilton Hotel, Secaucus, New Jersey. Eleven papers have been entered individually into EDB and ERA. The papers include reviews of the US DOE and EPRI programs in this area and papers by Swedish, West German, British and American organizations. The British papers concern the joint program of the USA, UK and FRG at Leatherhead. The key factor in several papers is the use of fluidized bed combustors, gas turbines, and steam turbines in combined-cycle power plants. One paper examines several combined-cycle alternatives. (LTN)

,

1980-04-01T23:59:59.000Z

357

Computational and experimental prediction of dust production in pebble bed reactors -- Part I  

Science Conference Proceedings (OSTI)

This paper describes the computational modeling and simulation, and experimental testing of graphite moderators in frictional contacts as anticipated in a pebble bed reactor. The potential of carbonaceous particulate generation due to frictional contact at the surface of pebbles and the ensuing entrainment and transport into the gas coolant are safety concerns at elevated temperatures under accident scenarios such as air ingress in the high temperature gas-cooled reactor. The safety concerns are due to the documented ability of carbonaceous particulates to adsorb fission products and transport them in the primary circuit of the pebble bed reactor, thus potentially giving rise to a relevant source term under accident scenarios. Here, a finite element approach is implemented to develop a nonlinear wear model in air environment. In this model, material wear coefficient is related to the changes in asperity height during wear. The present work reports a comparison between the finite element simulations and the experimental results obtained using a custom-designed tribometer. The experimental and computational results are used to estimate the quantity of nuclear grade graphite dust produced from a typical anticipated configuration. In Part II, results from a helium environment at higher temperatures and pressures are experimentally studied.

Maziar Rostamian; Gannon Johnson; Mie Hiruta; Gabriel P. Potirniche; Abderrafi M. Ougouag; Joshua J. Cogliati; Akira Tokuhiro

2013-10-01T23:59:59.000Z

358

Analysis of the Pebble-Bed VHTR Spectrum Shifting Capabilities for Advanced Fuel Cycles  

E-Print Network (OSTI)

Gas-cooled nuclear reactors have been receiving specific attention for Generation IV possibilities due to desired characteristics such as relatively low cost, short construction period, and inherent safety. Attractive inherent characteristics include an inert, single phase helium coolant, refractory coated fuel with high temperature capability and low fission product release, and graphite moderator with high temperature stability and long response times. The passively safe design has a relatively low power density, annular core, large negative temperature coefficient, and passive decay heat removal system. The objective of the U.S. DOE NERI Project is to assess the possibility, advantages and limitations of achieving ultra-long life VHTR (Very High Temperature Reactor) configurations by utilizing minor actinides as a fuel component. The present analysis takes into consideration and compares capabilities of pebble-bed core designs with various core and reflector configuration to allow spectrum shifting for advanced actinide fuels. Whole-core 3D models for pebble-bed design with multi-heterogeneity treatments in SCALE 5.0 are developed to compare computational results with experiments. Obtained results are in agreement with the available HTR-10 data. By altering the moderator to fuel ratio, a shift in the spectrum is observed. The use of minor actinides as fuel components relies on spectrum shifting capabilities. Actinide fueled VHTR configurations reveal promising performance. With an optimized pebble-bed model, the spectrum shifting abilities are apparent and effects of altered moderator to fuel ratio, and Dancoff factor are investigated. This will lead to a facilitated development of new fuel cycles in support of future operation of Generation IV nuclear energy systems.

Pritchard, Megan; Tsvetkov, Pavel

2009-09-30T23:59:59.000Z

359

Analysis of Pebble-Bed VHTR Spectrum Shifting Capabilities for Advanced Fuel Cycles  

E-Print Network (OSTI)

Gas-cooled nuclear reactors have been receiving specific attention for Generation IV possibilities due to desired characteristics such as relatively low cost, short construction period, and inherent safety. Attractive inherent characteristics include an inert, single phase helium coolant, refractory coated fuel with high temperature capability and low fission product release, and graphite moderator with high temperature stability and long response times. The passively safe design has a relatively low power density, annular core, large negative temperature coefficient, and passive decay heat removal system. The objective of the U.S. DOE NERI Project is to assess the possibility, advantages and limitations of achieving ultra-long life VHTR (Very High Temperature Reactor) configurations by utilizing minor actinides as a fuel component. The present analysis takes into consideration and compares capabilities of pebble-bed core designs with various core and reflector configuration to allow spectrum shifting for advanced actinide fuels. Whole-core 3D models for pebble-bed design with multi-heterogeneity treatments in SCALE 5.0 are developed to compare computational results with experiments. Obtained results are in agreement with the available HTR-10 data. By altering the moderator to fuel ratio, a shift in the spectrum is observed. The use of minor actinides as fuel components relies on spectrum shifting capabilities. Actinide fueled VHTR configurations reveal promising performance. With an optimized pebble-bed model, the spectrum shifting abilities are apparent and effects of altered moderator to fuel ratio, and Dancoff factor are investigated. This will lead to a facilitated development of new fuel cycles in support of future operation of Generation IV nuclear energy systems.

Pritchard, Megan

2006-07-11T23:59:59.000Z

360

FLUIDIZED BED STEAM REFORMER (FBSR) PRODUCT: MONOLITH FORMATION AND CHARACTERIZATION  

SciTech Connect

The most important requirement for Hanford's low activity waste (LAW) form for shallow land disposal is the chemical durability of the product. A secondary, but still essential specification, is the compressive strength of the material with regards to the strength of the material under shallow land disposal conditions, e.g. the weight of soil overburden and potential intrusion by future generations, because the term ''near-surface disposal'' indicates disposal in the uppermost portion, or approximately the top 30 meters, of the earth's surface. The THOR{reg_sign} Treatment Technologies (TTT) mineral waste form for LAW is granular in nature because it is formed by Fluidized Bed Steam Reforming (FBSR). As a granular product it has been shown to be as durable as Hanford's LAW glass during testing with ASTM C-1285-02 known as the Product Consistency Test (PCT) and with the Single Pass Flow Through Test (SPFT). Hanford Envelope A and Envelope C simulants both performed well during PCT and SPFT testing and during subsequent performance assessment modeling. This is partially due to the high aluminosilicate content of the mineral product which provides a natural aluminosilicate buffering mechanism that inhibits leaching and is known to occur in naturally occurring aluminosilicate mineral analogs. In order for the TTT Na-Al-Si (NAS) granular mineral product to meet the compressive strength requirements (ASTM C39) for a Hanford waste form, the granular product needs to be made into a monolith or disposed of in High Integrity Containers (HIC's). Additionally, the Hanford intruder scenario for disposal in the Immobilized Low Activity Waste (ILAW) trench is mitigated as there is reduced intruder exposure when a waste form is in a monolithic form. During the preliminary testing of a monolith binder for TTT's FBSR mineral product, four parameters were monitored: (1) waste loading (not optimized for each waste form tested); (2) density; (3) compressive strength; and (4) durability must not be compromised--binding agent should not react with the NAS product and binding agent should not create an unfavorable pH environment that may cause accelerated leaching. It is the goal of the present study to survey cementitious waste forms based on Ordinary Portland Cement (OPC), Ceramicrete, and hydroceramic binders by correlating waste loading, density and compressive strength and then determine if these binders affect the product performance in terms of the PCT response. This will be done by making a one-to-one comparison of the PCT response measured on granular NAS mineral product (mixed bed and fines products) with the PCT response of the monolithed NAS product in the different binders. Future studies may include, refining the above binders, and examining other binders. It is likely that binders formed from kaolin would be most compatible with the chemistry of the THOR{reg_sign} mineral waste form which is made by steam reforming of kaolin and sodium rich wastes. The economics of production on a large scale have yet to be investigated for any of the binders tested.

Jantzen, C

2006-09-13T23:59:59.000Z

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


361

Modularity of the MIT Pebble Bed Reactor for use by the commercial power industry  

E-Print Network (OSTI)

The Modular Pebble Bed Reactor is a small high temperature helium cooled reactor that is being considered for both electric power and hydrogen production. Pebble bed reactors are being developed in South Africa, China and ...

Hanlon-Hyssong, Jaime E

2008-01-01T23:59:59.000Z

362

Operation of a steam hydro-gasifier in a fluidized bed reactor  

E-Print Network (OSTI)

GASIFIER IN A FLUIDIZED BED REACTOR Inventors: Joseph M .a steam hydro-gasification reactor (SHR) the carbonaceous0012] Fluidized bed reactors are well known and used in a

Park, Chan Seung; Norbeck, Joseph N.

2008-01-01T23:59:59.000Z

363

DOE/OE National SCADA Test Bed Fiscal Year 2009 Work Plan | Department...  

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

OE National SCADA Test Bed Fiscal Year 2009 Work Plan DOEOE National SCADA Test Bed Fiscal Year 2009 Work Plan This document is designed to help guide and strengthen the DOEOE...

364

Atmospheric Fluidized-Bed Combustion Guidebook -- 2002 Update  

Science Conference Proceedings (OSTI)

Current operating experience shows that atmospheric fluidized-bed combustion (AFBC) boilers meet high environmental standards and are commercially viable and economically attractive. To make the best business decision, power producers need to fully evaluate the technology as a power generation option. The content of this AFBC Guidebook allows readers to become quickly informed about all aspects of the technology.

2002-12-05T23:59:59.000Z

365

Westinghouse standleg moving granular bed filter development program  

SciTech Connect

Advanced, coal-based, power plants, such as IGCC and Advanced-PFBC, are currently nearing commercial demonstration. These power plant technologies require hot gas filtration as part of their gas cleaning trains. Ceramic barrier filters are the major filter candidates being developed for these hot gas cleaning applications. While ceramic barrier filters achieve high levels of particle removal, there are concerns for their reliability and operability. An alternative hot gas filtration technology is the moving granular bed filter. These systems are at a lower state of development than ceramic barrier filters, and their effectiveness as filters is still in question. Their apparent attributes, result from their much less severe mechanical design and materials constraints, and the potential for more reliable, failure-free particle removal operation. The standleg moving granular-bed filter (SMGBF) system, is a compact unit that uses cocurrent gas-pellet contacting in an arrangement that greatly simplifies and enhances the distribution of dirty, process gas to the moving bed and allows effective disengagement of clean gas from the moving bed. This paper describes the equipment and process test results.

Newby, R.A.; Yang, W.C.; Smeltzer, E.E.; Lippert, T.E.

1994-10-01T23:59:59.000Z

366

Modular Pebble Bed Reactor High Temperature Gas Reactor  

E-Print Network (OSTI)

For 1150 MW Combined Heat and Power Station Oil Refinery Hydrogen Production Desalinization Plant VHTR;Equipment Layout #12;Modular Pebble Bed Reactor Thermal Power 250 MW Core Height 10.0 m Core Diameter 3.5 m · License by Test · Expert I&C System - Hands free operation #12;MIT MPBR Specifications Thermal Power 250

367

Packed bed reactor for photochemical .sup.196 Hg isotope separation  

DOE Patents (OSTI)

Straight tubes and randomly oriented pieces of tubing having been employed in a photochemical mercury enrichment reactor and have been found to improve the enrichment factor (E) and utilization (U) compared to a non-packed reactor. One preferred embodiment of this system uses a moving bed (via gravity) for random packing.

Grossman, Mark W. (Belmont, MA); Speer, Richard (Reading, MA)

1992-01-01T23:59:59.000Z

368

Isolated thermocouple amplifier system for stirred fixed-bed gasifier  

DOE Patents (OSTI)

A sensing system is provided for determining the bed temperature profile of the bed of a stirred, fixed-bed gasifier including a plurality of temperature sensors for sensing the bed temperature at different levels, a transmitter for transmitting data based on the outputs of the sensors to a remote operator's station, and a battery-based power supply. The system includes an isolation amplifier system comprising a plurality of isolation amplifier circuits for amplifying the outputs of the individual sensors. The isolation amplifier circuits each comprise an isolation operational amplifier connected to a sensor; a first flying capacitor circuit for, in operation, controlling the application of power from the power supply to the isolation amplifier; an output sample and hold circuit connected to the transmitter; a second flying capacitor circuit for, in operation, controlling the transfer of the output of the isolation amplifier to the sample and hold circuit; and a timing and control circuit for activating the first and second capacitor circuits in predetermined timed sequence. 4 figs.

Fasching, G.E.

1989-08-08T23:59:59.000Z

369

Method for using fast fluidized bed dry bottom coal gasification  

DOE Patents (OSTI)

Carbonaceous solid material such as coal is gasified in a fast fluidized bed gasification system utilizing dual fluidized beds of hot char. The coal in particulate form is introduced along with oxygen-containing gas and steam into the fast fluidized bed gasification zone of a gasifier assembly wherein the upward superficial gas velocity exceeds about 5.0 ft/sec and temperature is 1500.degree.-1850.degree. F. The resulting effluent gas and substantial char are passed through a primary cyclone separator, from which char solids are returned to the fluidized bed. Gas from the primary cyclone separator is passed to a secondary cyclone separator, from which remaining fine char solids are returned through an injection nozzle together with additional steam and oxygen-containing gas to an oxidation zone located at the bottom of the gasifier, wherein the upward gas velocity ranges from about 3-15 ft/sec and is maintained at 1600.degree.-200.degree. F. temperature. This gasification arrangement provides for increased utilization of the secondary char material to produce higher overall carbon conversion and product yields in the process.

Snell, George J. (Fords, NJ); Kydd, Paul H. (Lawrenceville, NJ)

1983-01-01T23:59:59.000Z

370

Isolated thermocouple amplifier system for stirred fixed-bed gasifier  

DOE Patents (OSTI)

A sensing system is provided for determining the bed temperature profile of the bed of a stirred, fixed-bed gasifier including a plurality of temperature sensors for sensing the bed temperature at different levels, a transmitter for transmitting data based on the outputs of the sensors to a remote operator's station, and a battery-based power supply. The system includes an isolation amplifier system comprising a plurality of isolation amplifier circuits for amplifying the outputs of the individual sensors. The isolation amplifier circuits each comprise an isolation operational amplifier connected to a sensor; a first "flying capacitor" circuit for, in operation, controlling the application of power from the power supply to the isolation amplifier; an output sample and hold circuit connected to the transmitter; a second "flying capacitor" circuit for, in operation, controlling the transfer of the output of the isolation amplifier to the sample and hold circuit; and a timing and control circuit for activating the first and second capacitor circuits in a predetermined timed sequence.

Fasching, George E. (Morgantown, WV)

1992-01-01T23:59:59.000Z

371

DMEC-1 Pressurized Circulating Fluidized-Bed Demonstration Project  

SciTech Connect

The DMEC-1 project will demonstrate the use of Pyropower`s PYROFLOW pressurized circulating fluidized bed technology to repower an existing coal fired generating station. This will be the first commercial application of this technology in the world. The project is now in budget period 1, the preliminary design phase.

Kruempel, G.E.; Ambrose, S.J. [Midwest Power, Des Moines, IA (United States); Provol, S.J. [Pyropower Corp., San Diego, CA (United States)

1992-12-01T23:59:59.000Z

372

Fixed-bed reforming with mid-cycle catalyst addition  

Science Conference Proceedings (OSTI)

A fixed-bed catalytic reforming process is described in which on-stream operation is begun with the catalyst retention volume in the first reactor less than 99% full and additional catalyst is added to said reactor while on-stream.

Houston, R.J.; McCoy, C.S.

1981-02-17T23:59:59.000Z

373

Alternatives for metal hydride storage bed heating and cooling  

DOE Green Energy (OSTI)

The reaction of hydrogen isotopes with the storage bed hydride material is exothermic during absorption and endothermic during desorption. Therefore, storage bed operation requires a cooling system to remove heat during absorption, and a heating system to add the heat needed for desorption. Three storage bed designs and their associated methods of heating and cooling and accountability are presented within. The first design is the current RTF (Replacement Tritium Facility) nitrogen heating and cooling system. The second design uses natural convection cooling with ambient glove box nitrogen and electrical resistance for heating. This design is referred to as the Naturally Cooled/Electrically Heated (NCEH) design. The third design uses forced convection cooling with ambient glove box nitrogen and electrical resistance for heating. The design is referred to as the Forced Convection Cooled/Electrically Heated (FCCEH) design. In this report the operation, storage bed design, and equipment required for heating, cooling, and accountability of each design are described. The advantages and disadvantages of each design are listed and discussed. Based on the information presented within, it is recommended that the NCEH design be selected for further development.

Fisher, I.A.; Ramirez, F.B.; Koonce, J.E.; Ward, D.E.; Heung, L.K.; Weimer, M.; Berkebile, W.; French, S.T.

1991-10-04T23:59:59.000Z

374

Paleoecology of the Greater Phyllopod Bed community, Burgess Shale  

E-Print Network (OSTI)

Paleoecology of the Greater Phyllopod Bed community, Burgess Shale Jean-Bernard Caron , Donald A and composition, ecological attributes, and environmental influences for the Middle Cambrian Burgess Shale ecosystems further suggest the Burgess Shale community was probably highly dependent on immigration from

Jackson, Don

375

Pulsed atmospheric fluidized bed combustion. Quarterly technical progress report, October--December 1993  

Science Conference Proceedings (OSTI)

This quarterly report consist almost entirely of engineering drawings of the proposed pulse fluidized-bed combustor.

Not Available

1994-01-31T23:59:59.000Z

376

CIRCULATING MOVING BED COMBUSTION PROOF OF CONCEPT Ã?¢Ã?Â?Ã?Â? PHASE II  

SciTech Connect

Circulating Moving Bed (CMB) combustion technology has its roots in traditional circulating fluidized bed technology and involves a novel method of solid fuel combustion and heat transfer. CMB technology represents a step change in improved performance and cost relative to conventional PC and FBC boilers. The CMB heat exchanger preheats the energy cycle working fluid, steam or air, to the high temperature levels required in systems for advanced power generation. Unique features of the CMB are the reduction of the heat transfer surfaces by about 60% as a result of the enhanced heat transfer rates, flexibility of operation, and about 30% lower cost over existing technology. The CMB Phase I project ran from July 2001 through March 2003. Its objective was to continue development of the CMB technology with a series of proof of concept tests. The tests were conducted at a scale that provided design data for scale up to a demonstration plant. These objectives were met by conducting a series of experiments in ALSTOM Power's Multi-use Test Facility (MTF). The MTF was modified to operate under CMB conditions of commercial interest. The objective of the tests were to evaluate gas-to-solids heat transfer in the upper furnace, assess agglomeration in the high temperature CMB bubbling bed, and evaluate solids-to-tube heat transfer in the moving bed heat exchanger. The Phase I program results showed that there are still some significant technical uncertainties that needed to be resolved before the technology can be confidently scaled up for a successful demonstration plant design. Work remained in three primary areas: (1) scale up of gas to solid heat transfer; (2) high temperature finned surface design and (3) the overall requirements of mechanical and process design. The CMB Phase II workscope built upon the results of Phase I and specifically addressed the remaining technical uncertainties. It included a scaled MTF heat transfer test to provide the necessary data to scale up gas-to-solids heat transfer. A stress test rig was built and tested to provide validation data for a stress model needed to support high temperature finned surface design. Additional cold flow model tests and MTF tests were conducted to address mechanical and process design issues. This information was then used to design and cost a commercial CMB design concept. Finally, the MBHE was reconfigured into a slice arrangement and tested for an extended duration at a commercial CFB plant.

Glen D. Jukkola

2010-06-30T23:59:59.000Z

377

Task 3.8 - pressurized fluidized-bed combustion  

DOE Green Energy (OSTI)

The focus of this work on pressurized fluidized-bed combustion (PFBC) is the development of sorbents for in-bed alkali control. The goal is to generate fundamental process information for development of a second-generation PFBC. Immediate objectives focus on the performance of sulfur sorbents, fate of alkali, and the Resource Conservation and Recovery Act (RCRA) heavy metals. The studies reported here focus on emission control strategies applied in the bed. Data from shakedown testing, alkali sampling, sulfur sorbent performance tests, and refuse-derived fuel (RDF) and lignite combustion tests are presented in detail. Initial results from the characterization of alkali gettering indicate that in-bed getters can remove a significant amount of alkali from the bed. Using kaolin as a sorbent, sodium levels in the flue gas were reduced from 3.6 ppm to less than 0.22 ppm. Sulfur was also reduced by 60% using the kaolin sorbent. Preliminary sulfur sorbent testing, which was designed to develop a reliable technique to predice sorbent performance, indicate that although the total sulfur capture is significantly lower than that observed in a full-scale PFBC, the emission trends are similar. RDF and RDF-lignite fuels had combustion efficiencies exceeding 99.0% in all test cases. Sulfur dioxide emission was significantly lower for the RDF fuels than for lignite fuel alone. Nitrogen oxide emission was also lower for the RDF-based fuels than for the lignite fuel. Both emission gases were well below current regulatory limits. Carbon monoxide and hydrocarbon emissions appeared to be slightly higher for the fuels containing RDF, but were below 9 ppm for the worst case. Analysis of volatile organic compound emission does not indicate an emission problem for these fuels. Chromium appears to be the only RCRA metal that might present some disposal problem; however, processing of the RDF with the wet resource recovery method should reduce chromium levels. 2 refs., 13 figs., 15 tabs.

NONE

1995-03-01T23:59:59.000Z

378

Method and apparatus for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier  

DOE Patents (OSTI)

A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier is described. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600 to 1800 F and are partially quenched with water to 1000 to 1200 F before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime /limestone. 1 fig.

Grindley, T.

1988-04-05T23:59:59.000Z

379

Joint initiation in bedded clastic rocks David T. McConaughy1  

E-Print Network (OSTI)

Joint initiation in bedded clastic rocks David T. McConaughy1 , Terry Engelder* Department) for cross-fold joints in siltstone beds of the Ithaca Formation, Appalachian Plateau, New York: planar bed structures. The relative abundance of each IP type varies with the stratigraphic position of the jointed body

Engelder, Terry

380

Designing nanostructured heterogeneous catalysts to exploit pulsing in gas-liquid packed bed reactors  

E-Print Network (OSTI)

41 Designing nanostructured heterogeneous catalysts to exploit pulsing in gas-liquid packed bed nanostructured catalysts for gas-liquid reactions, which have a system of macro pores designed to take advantage in volume of gas-liquid packed bed reactors (a.k.a. "trickle" beds) by an order of magnitude or more because

McCready, Mark J.

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


381

Analysis of granular flow in a pebble-bed nuclear reactor Chris H. Rycroft,1  

E-Print Network (OSTI)

Analysis of granular flow in a pebble-bed nuclear reactor Chris H. Rycroft,1 Gary S. Grest,2 James February 2006; published 24 August 2006 Pebble-bed nuclear reactor technology, which is currently being States, the Modular Pebble Bed Reactor MPBR 4,8 is a candidate for the next generation nuclear plant

Bazant, Martin Z.

382

Underwater microscope for measuring spatial and temporal changes in bed-sediment grain size  

E-Print Network (OSTI)

Underwater microscope for measuring spatial and temporal changes in bed-sediment grain size David M by Elsevier B.V. Keywords: Underwater microscope; Bed sediment; Grain size; In situ measurement; Colorado counts on a small subset of processed images. 2.3. Underwater microscope hardware Digital images of bed

383

Smart Grid Security Educational Training with ThunderCloud: A Virtual Security Test Bed  

Science Conference Proceedings (OSTI)

In this paper, we describe a cloud based virtual smart grid test bed: ThunderCloud, which can be used for domain-specific security educational training applicable to the smart grid environment. The test bed consists of virtual machines connected using ... Keywords: Domain-Specific Security Training, Smart Grid, Virtual Test Bed

Joseph Stites, Ambareen Siraj, Eric L. Brown

2013-10-01T23:59:59.000Z

384

PEER-REVIEW Detection Of Lateral Non-Uniformities In Fluidized Bed Combustors  

E-Print Network (OSTI)

, greatly influences solid circulation patterns and gas phase mixing which inturn affects various in-bed by Dent etal!! in a Fludized bed combustor. For a vertically rising bubble midway through the two sensorsPEER-REVIEW Detection Of Lateral Non-Uniformities In Fluidized Bed Combustors .. A. Venkata Ramayya

Columbia University

385

Assessing Vulnerabilities, Risks, and Consequences of Damage to Critical Infrastructure  

SciTech Connect

Since the publication of 'Critical Foundations: Protecting America's Infrastructure,' there has been a keen understanding of the complexity, interdependencies, and shared responsibility required to protect the nation's most critical assets that are essential to our way of life. The original 5 sectors defined in 1997 have grown to 18 Critical Infrastructures and Key Resources (CIKR), which are discussed in the 2009 National Infrastructure Protection Plan (NIPP) and its supporting sector-specific plans. The NIPP provides the structure for a national program dedicated to enhanced protection and resiliency of the nation's infrastructure. Lawrence Livermore National Laboratory (LLNL) provides in-depth, multi-disciplinary assessments of threat, vulnerability, and consequence across all 18 sectors at scales ranging from specific facilities to infrastructures spanning multi-state regions, such as the Oil and Natural Gas (ONG) sector. Like many of the CIKR sectors, the ONG sector is comprised of production, processing, distribution, and storage of highly valuable and potentially dangerous commodities. Furthermore, there are significant interdependencies with other sectors, including transportation, communication, finance, and government. Understanding the potentially devastating consequences and collateral damage resulting from a terrorist attack or natural event is an important element of LLNL's infrastructure security programs. Our work began in the energy sector in the late 1990s and quickly expanded other critical infrastructure sectors. We have performed over 600 physical assessments with a particular emphasis on those sectors that utilize, store, or ship potentially hazardous materials and for whom cyber security is important. The success of our approach is based on building awareness of vulnerabilities and risks and working directly with industry partners to collectively advance infrastructure protection. This approach consists of three phases: The Pre-Assessment Phase brings together infrastructure owners and operators to identify critical assets and help the team create a structured information request. During this phase, we gain information about the critical assets from those who are most familiar with operations and interdependencies, making the time we spend on the ground conducting the assessment much more productive and enabling the team to make actionable recommendations. The Assessment Phase analyzes 10 areas: Threat environment, cyber architecture, cyber penetration, physical security, physical penetration, operations security, policies and procedures, interdependencies, consequence analysis, and risk characterization. Each of these individual tasks uses direct and indirect data collection, site inspections, and structured and facilitated workshops to gather data. Because of the importance of understanding the cyber threat, LLNL has built both fixed and mobile cyber penetration, wireless penetration and supporting tools that can be tailored to fit customer needs. The Post-Assessment Phase brings vulnerability and risk assessments to the customer in a format that facilitates implementation of mitigation options. Often the assessment findings and recommendations are briefed and discussed with several levels of management and, if appropriate, across jurisdictional boundaries. The end result is enhanced awareness and informed protective measures. Over the last 15 years, we have continued to refine our methodology and capture lessons learned and best practices. The resulting risk and decision framework thus takes into consideration real-world constraints, including regulatory, operational, and economic realities. In addition to 'on the ground' assessments focused on mitigating vulnerabilities, we have integrated our computational and atmospheric dispersion capability with easy-to-use geo-referenced visualization tools to support emergency planning and response operations. LLNL is home to the National Atmospheric Release Advisory Center (NARAC) and the Interagency Modeling and Atmospheric Assessment Center (IMAAC). NA

Suski, N; Wuest, C

2011-02-04T23:59:59.000Z

386

A review of the Melcor Accident Consequence Code System (MACCS): Capabilities and applications  

Science Conference Proceedings (OSTI)

MACCS was developed at Sandia National Laboratories (SNL) under U.S. Nuclear Regulatory Commission (NRC) sponsorship to estimate the offsite consequences of potential severe accidents at nuclear power plants (NPPs). MACCS was publicly released in 1990. MACCS was developed to support the NRC`s probabilistic safety assessment (PSA) efforts. PSA techniques can provide a measure of the risk of reactor operation. PSAs are generally divided into three levels. Level one efforts identify potential plant damage states that lead to core damage and the associated probabilities, level two models damage progression and containment strength for establishing fission-product release categories, and level three efforts evaluate potential off-site consequences of radiological releases and the probabilities associated with the consequences. MACCS was designed as a tool for level three PSA analysis. MACCS performs probabilistic health and economic consequence assessments of hypothetical accidental releases of radioactive material from NPPs. MACCS includes models for atmospheric dispersion and transport, wet and dry deposition, the probabilistic treatment of meteorology, environmental transfer, countermeasure strategies, dosimetry, health effects, and economic impacts. The computer systems MACCS is designed to run on are the 386/486 PC, VAX/VMS, E3M RISC S/6000, Sun SPARC, and Cray UNICOS. This paper provides an overview of MACCS, reviews some of the applications of MACCS, international collaborations which have involved MACCS, current developmental efforts, and future directions.

Young, M.

1995-02-01T23:59:59.000Z

387

Investigations of Biomass Pretreatment and Submerged Fixed-bed Fermentation  

E-Print Network (OSTI)

To improve the MixAlco process and biomass pretreatment, five studies were conducted. Three studies related to fermentation, whereas the other two investigated the effectiveness of shock tube pretreatment (STP) coupled with oxidative lime pretreatment (OLP). In the first study, the constant-selectivity assumption used in the continuum particle distribution model (CPDM) was determined to be invalid. During a 32-day batch fermentation, selectivity increased from 0.10 to 0.40 g acid/g non-acid volatile solid (NAVS) digested. Future revisions to CPDM should incorporate a non-constant selectivity term. In the second study, a revised procedure was developed to provide a more accurate determination of moisture content. Conventional drying at 105 degrees C allowed product acids to vaporize with water, which introduced errors. Using the revised procedure, calcium hydroxide or sodium hydroxide was added to samples at a concentration of 0.01 g base/g sample, which retained acids in the sample. The mass of additional retained material closely matched that of the additional retained acid. Three related studies involving biomass pretreatment were performed. In the first, recommended parameters for pretreating sugarcane bagasse with OLP and STP were determined. Recommended OLP parameters were 130 degrees C, 6.9-bar O2, and 2-h duration. The effects of solids concentration, liquid fill volume, particle size, type of shotgun shell, number of shocks, and pretreatment order were investigated. Liquid fill volume, particle size, type of shotgun shell, and pretreatment order were significant variables, whereas solids concentration and number of shocks were not. Recommended OLP parameters were used as a basis for an additional experiment. To simulate industrial-scale pile fermentation, fixed-bed batch fermentation of OLP + STP sugarcane bagasse was performed in 1-L PVC fermentors. Rubber mulch was used as a structural support material to prevent filter plugging, which had been reported in previous work. After 42 d, acid concentration reached 8 g/L with yield approximately 0.1 g acid/g NAVS fed. Poor fermentation performance was caused by short solid-liquid contact time and poor pH control. A third biomass pretreatment experiment investigated the potential of pretreated corn stover as a potential ruminant feed. Five samples (raw, OLP, STP, OLP + STP, and STP + OLP) were analyzed for composition and in vitro digestibility. STP followed by OLP increased neutral detergent fiber (NDF) digestibility from 49.3 to 79.0 g NDF digested/100 g NDF fed. On an organic matter basis, STP + OLP corn stover plus water-soluble extractives had a total digestible nutrients (TDN) of 74.9, nearly reaching corn grain at 88.1.

Meysing, Daniel

2011-12-01T23:59:59.000Z

388

Optimizing the performance of desiccant beds for solar-regenerated cooling  

DOE Green Energy (OSTI)

Detailed computer simulations as well as a simplified psychrometric analysis are used to determine the increase in cooling system performance that can be realized through the use of nonhomogeneous or staged desiccant beds. A staged bed of four hypothetical desiccants is shown to give a 10% higher cooling capacity than a silica gel bed of the same thickness. Alternatively, the same cooling capacity is produced by a staged bed 37% thinner than the silica gel bed. These effects could be employed to reduce the parasitic power requirements of desiccant cooling systems.

Barlow, R.; Collier, K.

1981-03-01T23:59:59.000Z

389

CTR Fuel recovery system using regeneration of a molecular sieve drying bed  

DOE Patents (OSTI)

A primary molecular sieve drying bed is regenerated by circulating a hot inert gas through the heated primary bed to desorb water held on the bed. The inert gas plus water vapor is then cooled and passed through an auxiliary molecular sieve bed which adsorbs the water originally desorbed from the primary bed. The main advantage of the regeneration technique is that the partial pressure of water can be reduced to the 10.sup.-9 atm. range. This is significant in certain CTR applications where tritiated water (T.sub.2 O, HTO) must be collected and kept at very low partial pressure.

Folkers, Charles L. (Livermore, CA)

1981-01-01T23:59:59.000Z

390

The development of an integrated multistaged fluid bed retorting process. Technical report, October 1, 1992--December 31, 1992  

Science Conference Proceedings (OSTI)

The KENTORT II process includes integral fluidized bed zones for pyrolysis, gasification, and combustion of the oil shale. The purpose of this program is to design and test the KENTORT II process at the 50-lb/hr scale. Along with the major activity of assembling the components of the 50-lb/hr retort, work was also completed in other areas this quarter. Basic studies of the cracking and coking kinetics of model compounds in a fixed bed reactor were continued. Additionally, as part of the effort to investigate niche market applications for KENTORT II-derived products, a study of the synthesis of carbon fibers from the heavy fraction of KENTORT II shale oil was initiated.

Taulbee, D.; Fei, Y.; Carter, S. [and others

1993-01-01T23:59:59.000Z

391

Stability of flows in fluidized beds  

Science Conference Proceedings (OSTI)

We study the linearized stability of the state of uniform fluidization, within the context of the theory of mixtures. The mixture is assumed to be made up of a classical linearly viscous fluid mixed with solid particles. In marked departure from most of the previous studies, we model the solid as a granular material and assume a constitutive relation that stems from classical motions in continuum mechanics. The linearized stability analysis of the state of uniform fluidization, in general, leads to an eighth order equation for the characteristic whose root implies instability, when positive. We find that the characteristic equation can be factored and one of the factors is precisely the equation that governs the stability when we use a simplified analysis akin to that of the earlier study of Anderson and Jackson.

Not Available

1993-04-01T23:59:59.000Z

392

NNSA Releases Pictures, Video of Consequence Management Response Teams  

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

NNSA Releases Pictures, Video of Consequence Management Response NNSA Releases Pictures, Video of Consequence Management Response Teams Deploying to Japan NNSA Releases Pictures, Video of Consequence Management Response Teams Deploying to Japan March 15, 2011 - 12:00am Addthis WASHINGTON, D.C. - The National Nuclear Security Administration, a semi-autonomous agency within the U.S. Department of Energy, has released photographs and video of its Consequence Management Response Teams deploying from Nellis Air Force Base in Las Vegas, Nevada, to assist Japanese efforts in the response to the March 11 earthquake and tsunami. On March 15, 33 experts from NNSA and the Department of Energy arrived in Japan and have been deployed to U.S. consulates and military installations in Japan. These teams have the skills, expertise and equipment to help

393

Packing microstructure and local density variations of experimental and computational pebble beds  

Science Conference Proceedings (OSTI)

In pebble bed type nuclear reactors the fuel is contained in graphite pebbles, which form a randomly stacked bed with a non-uniform packing density. These variations can influence local coolant flow and power density and are a possible cause of hotspots. To analyse local density variations computational methods are needed that can generate randomly stacked pebble beds with a realistic packing structure on a pebble-to-pebble level. We first compare various properties of the local packing structure of a computed bed with those of an image made using computer aided X-ray tomography, looking at properties in the bulk of the bed and near the wall separately. Especially for the bulk of the bed, properties of the computed bed show good comparison with the scanned bed and with literature, giving confidence our method generates beds with realistic packing microstructure. Results also show the packing structure is different near the wall than in the bulk of the bed, with pebbles near the wall forming ordered layers similar to hexagonal close packing. Next, variations in the local packing density are investigated by comparing probability density functions of the packing fraction of small clusters of pebbles throughout the bed. Especially near the wall large variations in local packing fractions exists, with a higher probability for both clusters of pebbles with low (0.65) packing fraction, which could significantly affect flow rates and, together with higher power densities, could result in hotspots. (authors)

Auwerda, G. J.; Kloosterman, J. L.; Lathouwers, D.; Van Der Hagen, T. H. J. J. [Delft Univ. of Technology, Mekelweg 15, 2629 JB, Delft (Netherlands)

2012-07-01T23:59:59.000Z

394

Real-Time Building Energy Simulation Using EnergyPlus and the Building Controls Test Bed  

SciTech Connect

Most commercial buildings do not perform as well in practice as intended by the design and their performances often deteriorate over time. Reasons include faulty construction, malfunctioning equipment, incorrectly configured control systems and inappropriate operating procedures (Haves et al., 2001, Lee et al., 2007). To address this problem, the paper presents a simulation-based whole building performance monitoring tool that allows a comparison of building actual performance and expected performance in real time. The tool continuously acquires relevant building model input variables from existing Energy Management and Control System (EMCS). It then reports expected energy consumption as simulated of EnergyPlus. The Building Control Virtual Test Bed (BCVTB) is used as the software platform to provide data linkage between the EMCS, an EnergyPlus model, and a database. This paper describes the integrated real-time simulation environment. A proof-of-concept demonstration is also presented in the paper.

Pang, Xiufeng; Bhattachayra, Prajesh; O'Neill, Zheng; Haves, Philip; Wetter, Michael; Bailey, Trevor

2011-11-01T23:59:59.000Z

395

Element associations in ash from waste combustion in fluidized bed  

SciTech Connect

The incineration of MSW in fluidized beds is a commonly applied waste management practice. The composition of the ashes produced in a fluidized bed boiler has important environmental implications as potentially toxic trace elements may be associated with ash particles and it is therefore essential to determine the mechanisms controlling the association of trace elements to ash particles, including the role of major element composition. The research presented here uses micro-analytical techniques to study the distribution of major and trace elements and determine the importance of affinity-based binding mechanisms in separate cyclone ash particles from MSW combustion. Particle size and the occurrence of Ca and Fe were found to be important factors for the binding of trace elements to ash particles, but the binding largely depends on random associations based on the presence of a particle when trace elements condensate in the flue gas.

Karlfeldt Fedje, K., E-mail: karinka@chalmers.s [Department of Chemical and Biological Engineering, Division of Environmental Inorganic Chemistry, Chalmers University of Technology, Kemivaegen 10, 412 96 Goeteborg (Sweden); Rauch, S. [Department of Civil and Environmental Engineering, Division of Water Environment Technology, Chalmers University of Technology, Sven Hultins Gata 8, 412 96 Goeteborg (Sweden); Cho, P.; Steenari, B.-M. [Department of Chemical and Biological Engineering, Division of Environmental Inorganic Chemistry, Chalmers University of Technology, Kemivaegen 10, 412 96 Goeteborg (Sweden)

2010-07-15T23:59:59.000Z

396

Grate assembly for fixed-bed coal gasifier  

DOE Patents (OSTI)

A grate assembly for a coal gasifier of a moving-bed or fixed-bed type is provided for crushing agglomerates of solid material such as clinkers, tailoring the radial distribution of reactant gases entering the gasification reaction zone, and control of the radial distribution of downwardly moving solid velocities in the gasification and combustion zone. The clinker crushing is provided by pinching clinkers between vertically oriented stationary bars and angled bars supported on the upper surface of a rotating conical grate. The distribution of the reactant gases is provided by the selective positioning of horizontally oriented passageways extending through the grate. The radial distribution of the solids is provided by mounting a vertically and generally radially extending scoop mechanism on the upper surface of the grate near the apex thereof.

Notestein, J.E.

1992-12-31T23:59:59.000Z

397

Grate assembly for fixed-bed coal gasifier  

SciTech Connect

A grate assembly for a coal gasifier of a moving-bed or fixed-bed type is provided for crushing agglomerates of solid material such as clinkers, tailoring the radial distribution of reactant gases entering the gasification reaction zone, and control of the radial distribution of downwardly moving solid velocities in the gasification and combustion zone. The clinker crushing is provided by pinching clinkers between vertically oriented stationary bars and angled bars supported on the upper surface of a rotating conical grate. The distribution of the reactant gases is provided by the selective positioning of horizontally oriented passageways extending through the grate. The radial distribution of the solids is provided by mounting a vertically and generally radially extending scoop mechanism on the upper surface of the grate near the apex thereof.

Notestein, John E. (Morgantown, WV)

1993-01-01T23:59:59.000Z

398

METHOD FOR SENSING DEGREE OF FLUIDIZATION IN FLUIDIZED BED  

DOE Patents (OSTI)

A method is given for detecting, indicating, and controlling the degree of fluidization in a fluid-bed reactor into which powdered material is fed. The method comprises admitting of gas into the reactor, inserting a springsupported rod into the powder bed of the reactor, exciting the rod to vibrate at its resonant frequency, deriving a signal responsive to the amplitude of vibi-ation of the rod and spring, the signal being directiy proportional to the rate of flow of the gas through the reactor, displaying the signal to provide an indication of the degree of fluidization within the reactor, and controlling the rate of gas flow into the reactor until said signal stabilizes at a constant value to provide substantially complete fluidization within the reactor. (AEC)

Levey, R.P. Jr.; Fowler, A.H.

1961-12-12T23:59:59.000Z

399

Fluidized-bed pyrolysis of oil shale: oil yield, composition, and kinetics  

SciTech Connect

A quartz isothermal fluidized-bed reactor has been used to measure kinetics and oil properties relevant to surface processing of oil shale. The rate of oil formation has been described with two sequential first-order rate equations characterized by two rate constants, k/sub 1/ = 2.18 x 10/sup 10/ exp(-41.6 kcal/RT) s/sup -1/ and k/sub 2/ = 4.4 x 10/sup 6/ exp(-29.7 kcal/RT) s/sup -1/. These rate constants together with an expression for the appropriate weighting coefficients describe approximately 97/sup +/% of the total oil produced. A description is given of the results of different attempts to mathematically describe the data in a manner suitable for modeling applications. Preliminary results are also presented for species-selective kinetics of methane, ethene, ethane and hydrogen, where the latter is clearly distinguished as the product of a distinct intermediate. Oil yields from Western oil shale are approximately 100% Fischer assay. Oil composition is as expected based on previous work and the higher heating rates (temperatures) inherent in fluidized-bed pyrolysis. Neither the oil yield, composition nor the kinetics varied with particle size between 0.2 and 2.0 mm within experimental error. The qualitatively expected change in oil composition due to cracking was observed over the temperature range studied (460 to 540/sup 0/C). Eastern shale exhibited significantly faster kinetics and higher oil yields than did Western shale.

Richardson, J H; Huss, E B; Ott, L L; Clarkson, J E; Bishop, M O; Taylor, J R; Gregory, L J; Morris, C J

1982-09-01T23:59:59.000Z

400

Dynamic performance of packed-bed dehumidifiers: experimental results from the SERI desiccant test loop  

DOE Green Energy (OSTI)

Discussed are the design and construction of a desiccant test loop and results of tests with a silica-gel-packed bed. The test loop consists of two centrifugal fans, two duct heaters, a steam humidifier, 24.4m (80 ft) of 30-cm (12-in.) circular duct, instrumentation, and a test section. The loop is capable of testing adsorption and desorption modes at flow rates up to 0.340 kg/s (600 scfm) and at regeneration temperatures up to 120/sup 0/C (248/sup 0/F). Tests of a 74-cm(29-in.)-diameter, 3.2-cm(1.25-in.)-thick silica gel bed indicated that mass transfer occurs more readily in the adsorption direction than in the desorption direction. Pressure drop data indicated that the resistance of each of the two screens that hold the silica gel in place was equivalent to 2.5-cm(1-in.) of silica gel due to plugging. Results of the tests were also used to validate a SERI desiccant computer model, DESSIM.

Kutscher, C F; Barlow, R S

1982-08-01T23:59:59.000Z

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


401

Methane-producing microbial community in a coal bed of the Illinois Basin  

Science Conference Proceedings (OSTI)

A series of molecular and geochemical studies were performed to study microbial, coal bed methane formation in the eastern Illinois Basin. Results suggest that organic matter is biodegraded to simple molecules, such as H{sub 2} and CO{sub 2}, which fuel methanogenesis and the generation of large coal bed methane reserves. Small-subunit rRNA analysis of both the in situ microbial community and highly purified, methanogenic enrichments indicated that Methanocorpusculum is the dominant genus. Additionally, we characterized this methanogenic microorganism using scanning electron microscopy and distribution of intact polar cell membrane lipids. Phylogenetic studies of coal water samples helped us develop a model of methanogenic biodegradation of macromolecular coal and coal-derived oil by a complex microbial community. Based on enrichments, phylogenetic analyses, and calculated free energies at in situ subsurface conditions for relevant metabolisms (H{sub 2}-utilizing methanogenesis, acetoclastic methanogenesis, and homoacetogenesis), H{sub 2}-utilizing methanogenesis appears to be the dominant terminal process of biodegradation of coal organic matter at this location.

Strapoc, D.; Picardal, F.W.; Turich, C.; Schaperdoth, I.; Macalady, J.L.; Lipp, J.S.; Lin, Y.S.; Ertefai, T.F.; Schubotz, F.; Hinrichs, K.U.; Mastalerz, M.; Schimmelmann, A. [Indiana University, Bloomington, IN (United States). Dept. of Geological Science

2008-04-15T23:59:59.000Z

402

Analyzing ENSO Teleconnections in CMIP Models as a Measure of Model Fidelity in Simulating Precipitation  

Science Conference Proceedings (OSTI)

The accurate representation of precipitation is a recurring issue in climate models. El Niño–Southern Oscillation (ENSO) precipitation teleconnections provide a test bed for comparison of modeled to observed precipitation. The simulation quality ...

Baird Langenbrunner; J. David Neelin

2013-07-01T23:59:59.000Z

403

Prostate Bed Motion During Intensity-Modulated Radiotherapy Treatment  

SciTech Connect

Purpose: Conformal radiation therapy in the postprostatectomy setting requires accurate setup and localization of the prostatic fossa. In this series, we report prostate bed localization and motion characteristics, using data collected from implanted radiofrequency transponders. Methods and Materials: The Calypso four-dimensional localization system uses three implanted radiofrequency transponders for daily target localization and real-time tracking throughout a course of radiation therapy. We reviewed the localization and tracking reports for 20 patients who received ultrasonography-guided placement of Calypso transponders within the prostate bed prior to a course of intensity-modulated radiation therapy at Fox Chase Cancer Center. Results: At localization, prostate bed displacement relative to bony anatomy exceeded 5 mm in 9% of fractions in the anterior-posterior (A-P) direction and 21% of fractions in the superior-inferior (S-I) direction. The three-dimensional vector length from skin marks to Calypso alignment exceeded 1 cm in 24% of all 652 fractions with available setup data. During treatment, the target exceeded the 5-mm tracking limit for at least 30 sec in 11% of all fractions, generally in the A-P or S-I direction. In the A-P direction, target motion was twice as likely to move posteriorly, toward the rectum, than anteriorly. Fifteen percent of all treatments were interrupted for repositioning, and 70% of patients were repositioned at least once during their treatment course. Conclusion: Set-up errors and motion of the prostatic fossa during radiotherapy are nontrivial, leading to potential undertreatment of target and excess normal tissue toxicity if not taken into account during treatment planning. Localization and real-time tracking of the prostate bed via implanted Calypso transponders can be used to improve the accuracy of plan delivery.

Klayton, Tracy; Price, Robert; Buyyounouski, Mark K.; Sobczak, Mark [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States)] [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States); Greenberg, Richard [Department of Urologic Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States)] [Department of Urologic Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States); Li, Jinsheng; Keller, Lanea; Sopka, Dennis [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States)] [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States); Kutikov, Alexander [Department of Urologic Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States)] [Department of Urologic Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States); Horwitz, Eric M., E-mail: eric.horwitz@fccc.edu [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States)

2012-09-01T23:59:59.000Z

404

NUCLA Circulating Atmospheric Fluidized Bed Demonstration Project. 1990 Annual report  

Science Conference Proceedings (OSTI)

The objective of this DOE Cooperative Agreement is to conduct a cost-shared clean coal technology project to demonstrate the feasibility of circulating fluidized bed combustion technology and to evaluate economic, environmental, and operational benefits of CFB steam generators on a utility scale. At the conclusion of the Phase 2 program, testing related to satisfying these objectives was completed. Data analysis and reporting are scheduled for completion by October 1991. (VC)

Not Available

1992-02-01T23:59:59.000Z

405

Inclined fluidized bed system for drying fine coal  

SciTech Connect

Coal is processed in an inclined fluidized bed dryer operated in a plug-flow manner with zonal temperature and composition control, and an inert fluidizing gas, such as carbon dioxide or combustion gas. Recycled carbon dioxide, which is used for drying, pyrolysis, quenching, and cooling, is produced by partial decarboxylation of the coal. The coal is heated sufficiently to mobilize coal tar by further pyrolysis, which seals micropores upon quenching. Further cooling with carbon dioxide enhances stabilization.

Cha, Chang Y. (Golden, CO); Merriam, Norman W. (Laramie, WY); Boysen, John E. (Laramie, WY)

1992-02-11T23:59:59.000Z

406

Fluidized bed gasification ash reduction and removal process  

DOE Patents (OSTI)

In a fluidized bed gasification system an ash removal system to reduce the particulate ash to a maximum size or smaller, allow the ash to cool to a temperature lower than the gasifier and remove the ash from the gasifier system. The system consists of a crusher, a container containing level probes and a means for controlling the rotational speed of the crusher based on the level of ash within the container.

Schenone, Carl E. (Madison, PA); Rosinski, Joseph (Vanderbilt, PA)

1984-12-04T23:59:59.000Z

407

Fluidized bed gasification ash reduction and removal system  

DOE Patents (OSTI)

In a fluidized bed gasification system an ash removal system to reduce the particulate ash to a maximum size or smaller, allow the ash to cool to a temperature lower than the gasifier and remove the ash from the gasifier system. The system consists of a crusher, a container containing level probes and a means for controlling the rotational speed of the crusher based on the level of ash within the container.

Schenone, Carl E. (Madison, PA); Rosinski, Joseph (Vanderbilt, PA)

1984-02-28T23:59:59.000Z

408

Pulsed atmospheric fluidized bed combustor apparatus and process  

DOE Patents (OSTI)

A pulsed atmospheric fluidized bed reactor system is disclosed and claimed along with a process for utilization of same for the combustion of, e.g. high sulfur content coal. The system affords a economical, ecologically acceptable alternative to oil and gas fired combustors. The apparatus may also be employed for endothermic reaction, combustion of waste products, e.g. organic and medical waste, drying, calcining and the like.

Mansour, Momtaz N. (Columbia, MD)

1992-01-01T23:59:59.000Z

409

Biomass growth restriction in a packed bed reactor  

DOE Patents (OSTI)

When carrying out continuous biologically catalyzed reactions with anaerobic microorganisms attached to a support in an upflow packed bed column, growth of the microorganisms is restricted to prevent the microorganisms from plugging the column by limiting the availability of an essential nutrient and/or by the presence of predatory protozoa which consume the anaerobic microorganisms. A membrane disruptive detergent may be provided in the column to lyse dead microorganisms to make them available as nutrients for live microorganisms.

Griffith, William L. (Oak Ridge, TN); Compere, Alicia L. (Knoxville, TN)

1978-01-01T23:59:59.000Z

410

Pressurized fluidized-bed combustion part-load behavior. Volume I. Summary report  

SciTech Connect

Tests performed during 1980 to determine the part-load characteristics of a pressurized fluidized-bed combustor for a combined-cycle power plant and to examine its behavior during load changing are discussed. Part-load operation was achieved by varying the bed temperature by amounts between 200 to 300/sup 0/F and the bed depth from between 9 and 10 ft at rates varying between 0.2 ft/min and 0.5 ft/min. The performance at part-load steady-state conditions and during transient conditions is reported with information on combustion efficiency (99% at full-load with 9 ft bed depth and 1650/sup 0/F bed temperature; 95% with 4 ft depth and 1390/sup 0/F); sulfur retention (95/sup 0/ at full load to 80% at low bed depth and low bed temperature); sulfur emissions (no definitive results); NO/sub x/ emissions (tendency for increase as bed temperature was reduced); alkali emissions (no bed temperature effect detected); and heat transfer. It was demonstrated that load can be altered in a rapid and controlled manner by changing combinations of bed depth temperature and pressure. The most important practical change was the reduction in O/sub 2/ concentration which occurred when the bed height was increased at a rapid rate. The extra energy required to reheat the incoming bed material resulted (in the most extreme case) in a temporary drop in excess air from 65% to 12%. In a full-scale plant the loss of heat from the stored bed material would be much lower and the excess air trough when increasing load would not be as pronounced. Nevertheless, it seems prudent to design full-scale plant for a full load excess air of not less than about 50% when using bed depth as a load control parameter.

Roberts, A. G.; Pillai, K. K.; Raven, P.; Wood, P.

1981-09-01T23:59:59.000Z

411

Avoiding Carbon Bed Hot Spots in Thermal Process Off-Gas Systems  

Science Conference Proceedings (OSTI)

Mercury has had various uses in nuclear fuel reprocessing and other nuclear processes, and so is often present in radioactive and mixed (radioactive and hazardous) wastes. Test programs performed in recent years have shown that mercury in off-gas streams from processes that treat radioactive wastes can be controlled using fixed beds of activated sulfur-impregnated carbon, to levels low enough to comply with air emission regulations such as the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards. Carbon bed hot spots or fires have occurred several times during these tests, and also during a remediation of tanks that contained mixed waste. Hot spots occur when localized areas in a carbon bed become heated to temperatures where oxidation occurs. This heating typically occurs due to heat of absoption of gas species onto the carbon, but it can also be caused through external means such as external heaters used to heat the carbon bed vessel. Hot spots, if not promptly mitigated, can grow into bed fires. Carbon bed hot spots and fires must be avoided in processes that treat radioactive and mixed waste. Hot spots are detected by (a) monitoring in-bed and bed outlet gas temperatures, and (b) more important, monitoring of bed outlet gas CO concentrations. Hot spots are mitigated by (a) designing for appropriate in-bed gas velocity, for avoiding gas flow maldistribution, and for sufficient but not excessive bed depth, (b) appropriate monitoring and control of gas and bed temperatures and compositions, and (c) prompt implementation of corrective actions if bed hot spots are detected. Corrective actions must be implemented quickly if bed hot spots are detected, using a graded approach and sequence starting with corrective actions that are simple, quick, cause the least impact to the process, and are easiest to recover from.

Nick Soelberg; Joe Enneking

2011-05-01T23:59:59.000Z

412

NYU-DOE Pressurized Fluidized Bed Combustor Facility  

Science Conference Proceedings (OSTI)

New York University (NYU), under a Department of Energy (DOE) Contract, has designed and constructed a sub-pilot scale Pressurized Fluidized-Bed Combustor (PFBC) Facility at the Antonio Ferri Laboratories, Westbury, Long Island. The basic feature of this Experimental Research Facility is a well-instrumented, 30-inch diameter coal combustor capable of operating up to 10 atm and provided with a liberal number of ports, making it a versatile unit for study of fundamental in-bed phenomena. Additionally, the overall design features make it a flexible facility for solving a variety of industrial research problems. The main objectives of the facility are two-fold: (1) to perform research in important areas of Pressurized Fluidized-Bed Combustion like low-grade fuel combustion under pressure; and (2) to provide the PFBC community with a experimental research tool for basic and applied research in order to accelerate the commercialization of this technology. New York University will initially test the facility of burning low-grade fuels under pressure. During the test program, emphasis will be placed on burning North Dakota lignite under pressures up to 7 atm. The performance of lignite with regard to its feeding, combustion efficiency, sulfur adsorption and sorbent requirements will be investigated. This report describes the various systems of the PFBC facility and operating procedures, and presents an outline of the test program planned for the facility. Other details are provided in the Equipment and Maintenance Manual, Test Program and Data Acquisition Manual, and Training Manual.

Zakkay, V.; Kolar, A.; Sellakumar, K.; Srinivasaragavan, S.; Miller, G.; Panunzio, S.; Joseph, A.; Sundaresan, C.

1983-01-01T23:59:59.000Z

413

State of the art of pressurized fluidized bed combustion systems  

SciTech Connect

This report was prepared at the request of the Tennessee Valley Authority (TVA) to clarify the development status of the pressurized fluidized bed combustor (PFBC) and to place in perspective the problems which are yet to be solved before commercialization of the concept is practical. This report, in essence, supersedes the interim report published in 1979, Assessment of the State of the Art of Pressurized Fluidized Bed Combustion Systems. A brief overview of the PFBC concept is included citing potential advantages and disadvantages relative to atmospheric fluidized bed combustion (AFBC) and conventional pulverized coal plants. A survey of existing and developing PFBC experimental facilities is presented in some detail which includes the major accomplishments at the respective facilities. Recent data on plant emissions, turbine/gas cleanup systems, and overall efficiency are provided. Findings of several design studies are also discussed. The results of recent gas turbine and cascade tests have been encouraging although the full assessment of the accomplishments have not been made. The delay in construction of the Grimethorpe plant causes further delay in proof-testing full-size, rotating turbomachinery. Several parameters are recommended for further assessment in design studies including: (1) effect of turbine life on cost of power; and (2) effect of reduced gas turbine inlet temperature and pressure on cost of power.

Graves, R.L.

1980-09-01T23:59:59.000Z

414

Geomechanical risks in coal bed carbon dioxide sequestration  

Science Conference Proceedings (OSTI)

The purpose of this report is to summarize and evaluate geomechanical factors which should be taken into account in assessing the risk of leakage of CO{sub 2} from coal bed sequestration projects. The various steps in developing such a project will generate stresses and displacements in the coal seam and the adjacent overburden. The question is whether these stresses and displacements will generate new leakage pathways by failure of the rock or slip on pre-existing discontinuities such as fractures and faults. In order to evaluate the geomechanical issues in CO{sub 2} sequestration in coal beds, it is necessary to review each step in the process of development of such a project and evaluate its geomechanical impact. A coal bed methane production/CO{sub 2} sequestration project will be developed in four steps: (1) Formation dewatering and methane production; (2) CO{sub 2} injection with accompanying methane production; (3) Possible CO{sub 2} injection for sequestration only; and The approach taken in this study was to review each step: Identify the geomechanical processes associated with it, and assess the risks that leakage would result from these processes.

Myer, Larry R.

2003-07-01T23:59:59.000Z

415

Fluidized bed gasification of waste-derived fuels  

Science Conference Proceedings (OSTI)

Five alternative waste-derived fuels obtained from municipal solid waste and different post-consumer packaging were fed in a pilot-scale bubbling fluidized bed gasifier, having a maximum feeding capacity of 100 kg/h. The experimental runs utilized beds of natural olivine, quartz sand or dolomite, fluidized by air, and were carried out under various values of equivalence ratio. The process resulted technically feasible with all the materials tested. The olivine, a neo-silicate of Fe and Mg with an olive-green colour, has proven to be a good candidate to act as a bed catalyst for tar removal during gasification of polyolefin plastic wastes. Thanks to its catalytic activity it is possible to obtain very high fractions of hydrogen in the syngas (between 20% and 30%), even using air as the gasifying agent, i.e. in the most favourable economical conditions and with the simplest plant and reactor configuration. The catalytic activity of olivine was instead reduced or completely inhibited when waste-derived fuels from municipal solid wastes and aggregates of different post-consumer plastic packagings were fed. Anyhow, these materials have given acceptable performance, yielding a syngas of sufficient quality for energy applications after an adequate downstream cleaning.

Arena, Umberto, E-mail: umberto.arena@unina2.i [Department of Environmental Sciences, Second University of Naples, Via A. Vivaldi, 43, 81100 Caserta (Italy); AMRA s.c. a r.l., Via Nuova Agnano, 11, 80125 Napoli (Italy); Zaccariello, Lucio [Department of Environmental Sciences, Second University of Naples, Via A. Vivaldi, 43, 81100 Caserta (Italy); Mastellone, Maria Laura [Department of Environmental Sciences, Second University of Naples, Via A. Vivaldi, 43, 81100 Caserta (Italy); AMRA s.c. a r.l., Via Nuova Agnano, 11, 80125 Napoli (Italy)

2010-07-15T23:59:59.000Z

416

Capacitance-level/density monitor for fluidized-bed combustor  

DOE Patents (OSTI)

A multiple segment three-terminal type capacitance probe with segment selection, capacitance detection and compensation circuitry and read-out control for level/density measurements in a fluidized-bed vessel is provided. The probe is driven at a high excitation frequency of up to 50 kHz to sense quadrature (capacitive) current related to probe/vessel capacitance while being relatively insensitive to the resistance current component. Compensation circuitry is provided for generating a negative current of equal magnitude to cancel out only the resistive component current. Clock-operated control circuitry separately selects the probe segments in a predetermined order for detecting and storing this capacitance measurement. The selected segment acts as a guarded electrode and is connected to the read-out circuitry while all unselected segments are connected to the probe body, which together form the probe guard electrode. The selected probe segment capacitance component signal is directed to a corresponding segment channel sample and hold circuit dedicated to that segment to store the signal derived from that segment. This provides parallel outputs for display, computer input, etc., for the detected capacitance values. The rate of segment sampling may be varied to either monitor the dynamic density profile of the bed (high sampling rate) or monitor average bed characteristics (slower sampling rate).

Fasching, George E. (Morgantown, WV); Utt, Carroll E. (Morgantown, WV)

1982-01-01T23:59:59.000Z

417

THE STATE OF THE ART OF NUMERICAL MODELING OF THERMOHYDROLOGIC FLOW IN FRACTURED ROCK MASSES  

E-Print Network (OSTI)

thermal calculations for the WIPP site in southeastern NewWaste Isolation Pilot Plant (WIPP) in bedded salt. The codepersonal communication 1980). WIPP The modeling for WIPP is

Wang, J.S.Y.

2013-01-01T23:59:59.000Z

418

Probabilistic accident consequence uncertainty analysis -- Late health effects uncertain assessment. Volume 2: Appendices  

SciTech Connect

The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA late health effects models. This volume contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures, (3) the rationales and results for the expert panel on late health effects, (4) short biographies of the experts, and (5) the aggregated results of their responses.

Little, M.P.; Muirhead, C.R. [National Radiological Protection Board (United Kingdom); Goossens, L.H.J.; Kraan, B.C.P.; Cooke, R.M. [Delft Univ. of Technology (Netherlands); Harper, F.T. [Sandia National Labs., Albuquerque, NM (United States); Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States)

1997-12-01T23:59:59.000Z

419

Probabilistic accident consequence uncertainty analysis -- Early health effects uncertainty assessment. Volume 2: Appendices  

Science Conference Proceedings (OSTI)

The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA early health effects models. This volume contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures, (3) the rationales and results for the panel on early health effects, (4) short biographies of the experts, and (5) the aggregated results of their responses.

Haskin, F.E. [Univ. of New Mexico, Albuquerque, NM (United States); Harper, F.T. [Sandia National Labs., Albuquerque, NM (United States); Goossens, L.H.J.; Kraan, B.C.P. [Delft Univ. of Technology (Netherlands)

1997-12-01T23:59:59.000Z

420

Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for deposited material and external doses. Volume 2: Appendices  

SciTech Connect

The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA deposited material and external dose models. This volume contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures, (3) the rationales and results for the panel on deposited material and external doses, (4) short biographies of the experts, and (5) the aggregated results of their responses.

Goossens, L.H.J.; Kraan, B.C.P.; Cooke, R.M. [Delft Univ. of Technology (Netherlands); Boardman, J. [AEA Technology (United Kingdom); Jones, J.A. [National Radiological Protection Board (United Kingdom); Harper, F.T.; Young, M.L. [Sandia National Labs., Albuquerque, NM (United States); Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States)

1997-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "bed consequence modeling" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
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to obtain the most current and comprehensive results.


421

Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for internal dosimetry. Volume 2: Appendices  

Science Conference Proceedings (OSTI)

The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA internal dosimetry models. This volume contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures, (3) the rationales and results for the panel on internal dosimetry, (4) short biographies of the experts, and (5) the aggregated results of their responses.

Goossens, L.H.J.; Kraan, B.C.P.; Cooke, R.M. [Delft Univ. of Technology (Netherlands); Harrison, J.D. [National Radiological Protection Board (United Kingdom); Harper, F.T. [Sandia National Labs., Albuquerque, NM (United States); Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States)

1998-04-01T23:59:59.000Z

422

DEVELOPMENT OF PRESSURIZED CIRCULATING FLUIDIZED BED PARTIAL GASIFICATION MODULE (PGM)  

SciTech Connect

Foster Wheeler Development Corporation is working under DOE contract No. DE-FC26-00NT40972 to develop a partial gasification module (PGM) that represents a critical element of several potential coal-fired Vision 21 plants. When utilized for electrical power generation, these plants will operate with efficiencies greater than 60% while producing near zero emissions of traditional stack gas pollutants. The new process partially gasifies coal at elevated pressure producing a coal-derived syngas and a char residue. The syngas can be used to fuel the most advanced power producing equipment such as solid oxide fuel cells or gas turbines or processed to produce clean liquid fuels or chemicals for industrial users. The char residue is not wasted; it can also be used to generate electricity by fueling boilers that drive the most advanced ultra-supercritical pressure steam turbines. The unique aspect of the process is that it utilizes a pressurized circulating fluidized bed partial gasifier and does not attempt to consume the coal in a single step. To convert all the coal to syngas in a single step requires extremely high temperatures ({approx}2500 to 2800F) that melt and vaporize the coal and essentially drive all coal ash contaminants into the syngas. Since these contaminants can be corrosive to power generating equipment, the syngas must be cooled to near room temperature to enable a series of chemical processes to clean the syngas. Foster Wheeler's process operates at much lower temperatures that control/minimize the release of contaminants; this eliminates/minimizes the need for the expensive, complicated syngas heat exchangers and chemical cleanup systems typical of high temperature gasification. By performing the gasification in a circulating bed, a significant amount of syngas can still be produced despite the reduced temperature and the circulating bed allows easy scale up to large size plants. Rather than air, it can also operate with oxygen to facilitate sequestration of stack gas carbon dioxide gases for a 100% reduction in greenhouse gas emissions. The amount of syngas and char produced by the PGM can be tailored to fit the production objectives of the overall plant, i.e., power generation, clean liquid fuel production, chemicals production, etc. Hence, PGM is a robust building block that offers all the advantages of coal gasification but in a more user friendly form; it is also fuel flexible in that it can use alternative fuels such as biomass, sewerage sludge, etc. The PGM consists of a pressurized circulating fluidized bed (PCFB) reactor together with a recycle cyclone and a particulate removing barrier filter. Coal, air, steam, and possibly sand are fed to the bottom of the PCFB reactor and establish a relatively dense bed of coal/char in the bottom section. As these constituents react, a hot syngas is produced which conveys the solids residue vertically up through the reactor and into the recycle cyclone. Solids elutriated from the dense bed and contained in the syngas are collected in the cyclone and drain via a dipleg back to the dense bed at the bottom of the PCFB reactor. This recycle loop of hot solids acts as a thermal flywheel and promotes efficient solid-gas chemical reaction.

Unknown

2001-07-10T23:59:59.000Z

423

The development of an integrated multistaged fluid bed retorting process. Annual report, October 1, 1992--September 30, 1993  

SciTech Connect

This report summarizes the progress made on the development of an integrated multistage fluidized bed retorting process (KENTORT II) during the period of October 1, 1992 through September 30, 1993 under Cooperative Agreement No. DE-FC21-90MC27286 with the Morgantown Energy Technology Center, US Department of Energy. The KENTORT II process includes integral fluidized bed zones for pyrolysis, gasification, and combustion of the oil shale. The purpose of this program is to design and test the KENTORT II process at the 50-lb/hr scale. The PDU was assembled, instrumented and tested during this fiscal year. Along with the major activity of commissioning the 50-lb/hr retort, work was also completed in other areas. Basic studies of the cracking and coking kinetics of model compounds in a fixed bed reactor were continued. Additionally, as part of the effort to investigate niche market applications for KENTORT II-derived products, a study of the synthesis of carbon fibers from the heavy fraction of KENTORT II shale oil was initiated.

Carter, S.; Taulbee, D.; Vego, A.; Stehn, J.; Fei, Y.; Robl, T.; Derbyshire, F.

1993-11-01T23:59:59.000Z

424

Hot-gas desulfurization. II. Use of gasifier ash in a fluidized-bed process. Final report  

DOE Green Energy (OSTI)

Three gasifier coal ashes were used as reactant/sorbents in batch fluidized-beds to remove hydrogen sulfide from hot, made-up fuel gases. It is predominantly the iron oxide in the ash that reacts with and removes the hydrogen sulfide; the sulfur reappears in ferrous sulfide. Sulfided ashes were regenerated by hot, fluidizing streams of oxygen in air; the sulfur is recovered as sulfur dioxide, exclusively. Ash sorption efficiency and sulfur capacity increase and stabilize after several cycles of use. These two parameters vary directly with the iron oxide content of the ash and process temperature, but are independent of particle size in the range 0.01 - 0.02 cm. A western Kentucky No. 9 ash containing 22 weight percent iron as iron oxide sorbed 4.3 weight percent sulfur at 1200/sup 0/F with an ash sorption efficiency of 0.83 at ten percent breakthrough. A global, fluidized-bed, reaction rate model was fitted to the data and it was concluded that chemical kinetics is the controlling mechanism with a predicted activation energy of 19,600 Btu/lb mol. Iron oxide reduction and the water-gas-shift reaction were two side reactions that occurred during desulfurization. The regeneration reaction occurred very rapidly in the fluid-bed regime, and it is suspected that mass transfer is the controlling phenomenon.

Schrodt, J.T.

1981-02-01T23:59:59.000Z

425

FACT SHEET ON THE CONSEQUENCES OF A FAILED DRUG TEST  

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

SHEET ON THE CONSEQUENCES OF A POSITIVE DRUG TEST SHEET ON THE CONSEQUENCES OF A POSITIVE DRUG TEST The Secretary has determined that applicants for, and holders of, a DOE "Q" or "L" access authorization (security clearance) will be in Testing Designated Positions (TDP) as specified in DOE Order 3792.3, Drug-Free Federal Workplace Testing Implementation Program, for federal employees, and Title 10 Code of Federal Regulations, Part 707, Workplace Substance Abuse Programs at DOE Sites, for contractor employees. Accordingly, individuals who are either in, or are selected for, a TDP are subject to applicant, random, and "for cause" testing. The information below summarizes the consequences of a positive test for drugs for each category of

426

Probabilistic accident consequence uncertainty analysis: Dispersion and deposition uncertainty assessment, main report  

SciTech Connect

The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the risks presented by nuclear installations based on postulated frequencies and magnitudes of potential accidents. In 1991, the US Nuclear Regulatory Commission (NRC) and the Commission of the European Communities (CEC) began a joint uncertainty analysis of the two codes. The ultimate objective of the joint effort was to develop credible and traceable uncertainty distributions for the input variables of the codes. Expert elicitation was identified as the best technology available for developing a library of uncertainty distributions for the selected consequence parameters. The study was formulated jointly and was limited to the current code models and to physical quantities that could be measured in experiments. Experts developed their distributions independently. To validate the distributions generated for the wet deposition input variables, samples were taken from these distributions and propagated through the wet deposition code model. Resulting distributions closely replicated the aggregated elicited wet deposition distributions. To validate the distributions generated for the dispersion code input variables, samples from the distributions and propagated through the Gaussian plume model (GPM) implemented in the MACCS and COSYMA codes. Project teams from the NRC and CEC cooperated successfully to develop and implement a unified process for the elaboration of uncertainty distributions on consequence code input parameters. Formal expert judgment elicitation proved valuable for synthesizing the best available information. Distributions on measurable atmospheric dispersion and deposition parameters were successfully elicited from experts involved in the many phenomenological areas of consequence analysis. This volume is the first of a three-volume document describing the project.

Harper, F.T.; Young, M.L.; Miller, L.A. [Sandia National Labs., Albuquerque, NM (United States); Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States); Lui, C.H. [Nuclear Regulatory Commission, Washington, DC (United States); Goossens, L.H.J.; Cooke, R.M. [Delft Univ. of Technology (Netherlands); Paesler-Sauer, J. [Research Center, Karlsruhe (Germany); Helton, J.C. [and others

1995-01-01T23:59:59.000Z

427

Nuclear dynamics consequence analysis of SNF disposed in volcanic tuff  

SciTech Connect

This paper describes criticality analyses for spent nuclear fuels in a geologic repository. The analyses investigated criticality potential, criticality excursion consequences, and the probability frequency for nuclear criticality. Key findings include: expected number of fissions per excursion range from 10{sup 17} to 10{sup 20}, repeated rate of criticalities range from 3 to 30 per year, and the probability frequency for criticality initiators (based on rough-order-of-magnitude calculations) is 7{times}10{sup {minus}7}. Overall results indicate that criticality consequences are a minor contribution to the biological hazards caused by the disposal of spent nuclear material.

Sanchez, L.C.; Cochrane, K. [Sandia National Labs., Albuquerque, NM (United States); Rath, J.S. [New Mexico Engineering Research Inst., Albuquerque, NM (United States); Taylor, L.L. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

1998-05-01T23:59:59.000Z

428

SPOUTED BED ELECTRODES (SBE) FOR DIRECT UTILIZATION OF CARBON IN FUEL CELLS  

DOE Green Energy (OSTI)

This Phase I project was focused on an investigation of spouted bed particulate electrodes for the direct utilization of solid carbon in fuel cells. This approach involves the use of a circulating carbon particle/molten carbonate slurry in the cell that provides a few critical functions: it (1) fuels the cell continuously with entrained carbon particles; (2) brings particles to the anode surfaces hydrodynamically; (3) removes ash from the anode surfaces and the cell hydrodynamically; (4) provides a facile means of cell temperature control due to its large thermal capacitance; (5) provides for electrolyte maintenance and control in the electrode separator(s); and (6) can (potentially) improve carbon conversion rates by ''pre-activating'' carbon particle surfaces via formation of intermediate oxygen surface complexes in the bulk molten carbonate. The approach of this scoping project was twofold: (1) adaptation and application of a CFD code, originally developed to simulate particle circulation in spouted bed electrolytic reactors, to carbon particle circulation in DCFC systems; and (2) experimental investigation of the hydrodynamics of carbon slurry circulation in DCFC systems using simulated slurry mixtures. The CFD model results demonstrated that slurry recirculation can be used to hydrodynamically feed carbon particles to anode surfaces. Variations of internal configurations were investigated in order to explore effects on contacting. It was shown that good contacting with inclined surfaces could be achieved even when the particles are of the same density as the molten carbonate. The use of CO{sub 2} product gas from the fuel cell as a ''lift-gas'' to circulate the slurry was also investigated with the model. The results showed that this is an effective method of slurry circulation; it entrains carbon particles more effectively in the draft duct and produces a somewhat slower recirculation rate, and thus higher residence times on anode surfaces, and can be controlled completely via pressure balance. Experimental investigations in a rectangular spouted vessel hydrodynamics apparatus (SVHA) showed that hydrodynamics can be used to control the circulation, residence time, and distribution of carbon within the spouted bed, as well as provide good particle contact with anode surfaces. This was shown to be a function of viscosity, carbon loading, and particle size, as well as relative densities. Higher viscosities and smaller particle sizes favor more efficient particle entrainment in the draft duct, and particle recirculation. Both the computational and experimental results are consistent with each another and exhibit the same general qualitative behavior. Based upon this work, a design of a prototype SBE/DCFC cell was developed and is presented.

J.M. Calo

2004-12-01T23:59:59.000Z

429

OSPREY Model  

SciTech Connect

The absence of industrial scale nuclear fuel reprocessing in the U.S. has precluded the necessary driver for developing the advanced simulation capability now prevalent in so many other countries. Thus, it is essential to model complex series of unit operations to simulate, understand, and predict inherent transient behavior and feedback loops. A capability of accurately simulating the dynamic behavior of advanced fuel cycle separation processes will provide substantial cost savings and many technical benefits. The specific fuel cycle separation process discussed in this report is the off-gas treatment system. The off-gas separation consists of a series of scrubbers and adsorption beds to capture constituents of interest. Dynamic models are being developed to simulate each unit operation involved so each unit operation can be used as a stand-alone model and in series with multiple others. Currently, an adsorption model has been developed within Multi-physics Object Oriented Simulation Environment (MOOSE) developed at the Idaho National Laboratory (INL). Off-gas Separation and REcoverY (OSPREY) models the adsorption of off-gas constituents for dispersed plug flow in a packed bed under non-isothermal and non-isobaric conditions. Inputs to the model include gas, sorbent, and column properties, equilibrium and kinetic data, and inlet conditions. The simulation outputs component concentrations along the column length as a function of time from which breakthrough data is obtained. The breakthrough data can be used to determine bed capacity, which in turn can be used to size columns. It also outputs temperature along the column length as a function of time and pressure drop along the column length. Experimental data and parameters were input into the adsorption model to develop models specific for krypton adsorption. The same can be done for iodine, xenon, and tritium. The model will be validated with experimental breakthrough curves. Customers will be given access to OSPREY to used and evaluate the model.

Veronica J. Rutledge

2013-01-01T23:59:59.000Z

430

Progress in validation of structural codes for radioactive waste repository applications in bedded salt  

SciTech Connect

Over the last nine years, coordinated activities in laboratory database generation, constitutive model formulation, and numerical code capability development have led to an improved ability of thermal/structural codes to predict the creep deformation of underground rooms in bedded salt deposits. In the last year, these codes have been undergoing preliminary validation against an extensive database collected from the large scale underground structural in situ tests at the Waste Isolation Pilot Plant (WIPP) in Southeastern New Mexico. This validation exercise has allowed prediction capabilities to be evaluated for accuracy. We present here a summary of the predictive capability and the nature of the in situ database involved in the validation exercise. The WIPP validation exercise has proven to be especially productive. 7 refs., 4 figs., 1 tab.

Munson, D.E. (Sandia National Labs., Albuquerque, NM (USA)); DeVries, K.L. (RE/SPEC, Inc., Rapid City, SD (USA))

1990-08-01T23:59:59.000Z

431

Characterization of bedded salt for storage caverns -- A case study from the Midland Basin, Texas  

SciTech Connect

The geometry of Permian bedding salt in the Midland Basin is a product of interaction between depositional facies and postdepositional modification by salt dissolution. Mapping high-frequency cycle patterns in cross section and map view using wireline logs documents the salt geometry. Geologically based interpretation of depositional and dissolution processes provides a powerful tool for mapping and geometry of salt to assess the suitability of sites for development of solution-mined storage caverns. In addition, this process-based description of salt geometry complements existing data about the evolution of one of the best-known sedimentary basins in the world, and can serve as a genetic model to assist in interpreting other salts.

Hovorka, Susan D.; Nava, Robin

2000-06-13T23:59:59.000Z

432

Continuous Ethanol Production Using Immobilized-Cell/Enzyme Biocatalysts in Fluidized-Bed Bioreactor (FBR)  

DOE Green Energy (OSTI)

The immobilized-cell fluidized-bed bioreactor (FBR) was developed at Oak Ridge National Laboratory (ORNL). Previous studies at ORNL using immobilized Zymomonas mobilis in FBR at both laboratory and demonstration scale (4-in-ID by 20-ft-tall) have shown that the system was more than 50 times as productive as industrial benchmarks (batch and fed-batch free cell fermentations for ethanol production from glucose). Economic analysis showed that a continuous process employing the FBR technology to produce ethanol from corn-derived glucose would offer savings of three to six cents per gallon of ethanol compared to a typical batch process. The application of the FBR technology for ethanol production was extended to investigate more complex feedstocks, which included starch and lignocellulosic-derived mixed sugars. Economic analysis and mathematical modeling of the reactor were included in the investigation. This report summarizes the results of these extensive studies.

Nghiem, NP

2003-11-16T23:59:59.000Z

433

DOE National SCADA Test Bed Program Multi-Year Plan | Department of Energy  

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

National SCADA Test Bed Program Multi-Year Plan National SCADA Test Bed Program Multi-Year Plan DOE National SCADA Test Bed Program Multi-Year Plan This document presents the National SCADA Test Bed Program Multi-Year Plan, a coherent strategy for improving the cyber security of control systems in the energy sector. The NSTB Program is conducted within DOE's Office of Electricity Delivery and Energy Reliability (OE), which leads national efforts to modernize the electric grid, enhance the security and reliability of the energy infrastructure, and facilitate recovery from disruptions to the energy supply. The Plan covers the planning period of fiscal year 2008 to 2013. DOE National SCADA Test Bed Program Multi-Year Plan More Documents & Publications DOE/OE National SCADA Test Bed Fiscal Year 2009 Work Plan

434

Polarized seismic and solitary waves run-up at the sea bed  

Science Conference Proceedings (OSTI)

The polarization effects in hydrodynamics are studied. Hydrodynamic equation for the nonlinear wave is used along with the polarized solitary waves and seismic waves act as initial waves. The model is then solved by Fourier spectral and Runge-Kutta 4 methods, and the surface plot is drawn. The output demonstrates the inundation behaviors. Consequently, the polarized seismic waves along with the polarized solitary waves tend to generate dissimilar inundation which is more disastrous.

Dennis, L. C.C.; Zainal, A. A.; Faisal, S. Y. [Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia); Universiti Teknologi Malaysia, 81310 Johor Bahru (Malaysia)

2012-09-26T23:59:59.000Z

435

Predicted temperature/time histories resulting from the burial of nuclear waste canisters in bedded salt  

SciTech Connect

This report provides computed thermal mappings for bedded salt surrounding canisters containing nuclear waste. This information can be used to study the possible migration of fluids within bedded salt under the influence of thermal gradients created by the heat-generating nuclear waste. The results presented were obtained from CINDA thermal models. Three different drift/canister configurations were modeled. The thermal conductivity of the salt was assumed to be temperature dependent while both the density and specific heat were assumed to be constant. Thermal power densities of 30, 75, and 150 kW/acre were examined with canister powers of 0.581 kW (51.6 canisters/acre), 3.5 kW (21.4 canisters/acre), and 3.5 kW (42.9 canisters/acre) at emplacement, respectively. These three cases resulted in maximum salt temperatures of 55/sup 0/C, 117/sup 0/C, and 176/sup 0/C, respectively; and maximum thermal gradients of -15/sup 0/C/m, -63/sup 0/C/m, and -101/sup 0/C/m, respectively. Computer-generated plots of temperature versus distance in horizontal planes at the top, midpoint, and bottom of the canister were made for several times after emplacement. Logarithmic or linear equations (whichever provided the better fit) were used to describe these curves. Derivatives of temperature with respect to distance were then taken and results of the form x(dT/dx) and dT/dx for the logarithmic and linear equations, respectively, were plotted against time. For the two cases where the waste thermal outputs decayed exponentially, it was found that x(dT/dx) and dT/dx were linear functions of time over a large period of years.

George, O.L. Jr.

1980-07-01T23:59:59.000Z

436

CERTS Microgrid Laboratory Test Bed - PIER Final Project Report  

Science Conference Proceedings (OSTI)

The objective of the CERTS Microgrid Laboratory Test Bed project was to enhance the ease of integrating small energy sources into a microgrid. The project accomplished this objective by developing and demonstrating three advanced techniques, collectively referred to as the CERTS Microgrid concept, that significantly reduce the level of custom field engineering needed to operate microgrids consisting of small generating sources. The techniques comprising the CERTS Microgrid concept are: 1) a method for effecting automatic and seamless transitions between grid-connected and islanded modes of operation; 2) an approach to electrical protection within the microgrid that does not depend on high fault currents; and 3) a method for microgrid control that achieves voltage and frequency stability under islanded conditions without requiring high-speed communications. The techniques were demonstrated at a full-scale test bed built near Columbus, Ohio and operated by American Electric Power. The testing fully confirmed earlier research that had been conducted initially through analytical simulations, then through laboratory emulations, and finally through factory acceptance testing of individual microgrid components. The islanding and resychronization method met all Institute of Electrical and Electronics Engineers 1547 and power quality requirements. The electrical protections system was able to