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1

Mathematical modeling of fluidized bed reactors  

E-Print Network (OSTI)

III-B. Bubbling Bed Model (BBM). 26 TABLE OF CONTENTS (continued) CHAPTER III-8-1. BBM with Constant Bubble Size III-B-2. BBM with Variable Bubble Size III-C. Countercurrent Backmixing Model (CCBM). Page 28 29 30 III-C-1. CCBM with Constant... IV NUMERICAL RESULTS AND DISCUSSION. IV-A. Langmuir-Hinshelwood Type of Kinetics. IV-B. First Order Kinetics . 57 IV-B-1. Davidson and Harrison Model (DHM) . . 57 IV-8-2. Bubbling Bed Model (BBM). IV-B-3. Countercurrent Backmixing Model (CCBM...

Nasif, Nilufer Havva

2012-06-07T23:59:59.000Z

2

Model for attrition in fluidized beds  

SciTech Connect

A model developed to predict the particle-size distribution and amount of fines generated during the attrition of particles in fluidized beds agrees well with experimental data for siderite iron ore and lignite char. Certain parameters used in the model are independent of particle size, orifice size, system pressure, bed weight, and attrition time, thus making the model suitable for scale-up purposes. Although the analysis was limited to a single jet with the attrition occurring at room temperature, the model can be extended to multi-jet, high-temperature operations.

Chen, T.P.; Sishtla, C.I.; Punwani, D.V.; Arastoopour, H.

1980-01-01T23:59:59.000Z

3

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

4

An innovative bed temperature-oriented modeling and robust control of a circulating fluidized bed combustor  

Science Journals Connector (OSTI)

Circulating fluidized bed (CFB) combustion systems are increasingly used as superior coal burning systems in power generation due to their higher efficiency and lower emissions. However, because of their non-linearity and complex behavior, it is difficult to build a comprehensive model that incorporates all the system dynamics. In this paper, a mathematical model of the circulating fluidized bed combustion system based on mass and energy conservation equations was successfully extracted. Using these correlations, a state space dynamical model oriented to bed temperature has been obtained based on subspace method. Bed temperature, which influences boiler overall efficiency and the rate of pollutants emission, is one of the most significant parameters in the operation of these types of systems. Having dynamic and parametric uncertainties in the model, a robust control algorithm based on linear matrix inequalities (LMI) have been applied to control the bed temperature by input parameters, i.e. coal feed rate and fluidization velocity. The controller proposed properly sets the temperature to our desired range with a minimum tracking error and minimizes the sensitivity of the closed-loop system to disturbances caused by uncertainties such as change in feeding coal, while the settling time of the system is significantly decreased.

Aboozar Hadavand; Ali Akbar Jalali; Parviz Famouri

2008-01-01T23:59:59.000Z

5

Advances in mathematical modeling of fluidized bed gasification  

Science Journals Connector (OSTI)

Abstract Gasification is the thermochemical conversion of solid fuel into the gas which contains mainly hydrogen, carbon monoxide, carbon dioxide, methane and nitrogen. In gasification, fluidized bed technology is widely used due to its various advantageous features which include high heat transfer, uniform and controllable temperature and favorable gas–solid contacting. Modeling and simulation of fluidized bed gasification is useful for optimizing the gasifier design and operation with minimal temporal and financial cost. The present work investigates the different modeling approaches applied to the fluidized bed gasification systems. These models are broadly classified as the equilibrium model and the rate based or kinetic model. On the other hand, depending on the description of the hydrodynamic of the bed, fluidized bed models may also be classified as the two-phase flow model, the Euler–Euler model and the Euler–Lagrange model. Mathematical formulation of each of the model mentioned above and their merits and demerits are discussed. Detail reviews of different model used by different researchers with major results obtained by them are presented while the special focus is given on Euler–Euler and Euler–Lagrange CFD models.

Chanchal Loha; Sai Gu; Juray De Wilde; Pinakeswar Mahanta; Pradip K. Chatterjee

2014-01-01T23:59:59.000Z

6

Model for boiling and dryout in particle beds. [LMFBR  

SciTech Connect

Over the last ten years experiments and modeling of dryout in particle beds have produced over fifty papers. Considering only volume-heated beds, over 250 dryout measurements have been made, and are listed in this work. In addition, fifteen models to predict dryout have been produced and are discussed. A model is developed in this report for one-dimensional boiling and dryout in a porous medium. It is based on conservation laws for mass, momentum, and energy. The initial coupled differential equations are reduced to a single first-order differential equation with an algebraic equation for the upper boundary condition. The model includes the effects of both laminar and turbulent flow, two-phase friction, and capillary force. The boundary condition at the bed bottom includes the possibility of inflowing liquid and either an adiabatic or a bottom-cooled support structure. The top of the bed may be either channeled or subcooled. In the first case the channel length and the saturation at the base of the channels are predicted. In the latter case, a criterion for penetration of the subcooled zone by channels is obtained.

Lipinski, R. J.

1982-06-01T23:59:59.000Z

7

Emergent Behavior in a Low-Order Fluidized-Bed Bubble Model  

E-Print Network (OSTI)

Emergent Behavior in a Low-Order Fluidized-Bed Bubble Model John S. Halow National Energy of this type of model to describe the dynamics of voids in bubbling fluidized beds. The model considers vertical interactions between neighboring bubbles in fluidized beds. Emergent collective behavior is shown

Tennessee, University of

8

Modeling forced poolriffle hydraulics in a boulder-bed stream, southern California  

E-Print Network (OSTI)

Modeling forced pool­riffle hydraulics in a boulder-bed stream, southern California Lee R. Harrison in boulder-bed channels. Here, we use a high-resolution two-dimensional flow model to investigate­riffle sequence in a boulder-bed stream. Model output indicates that at low discharge, a peak zone of shear stress

Keller, Ed

9

A cold model experimental study on the flow characteristics of bed material in a fluidized bed bottom ash cooler in a CFB boiler  

Science Journals Connector (OSTI)

A cold model experimental study on the flowing characteristics of bed material between a fluidized bed ash cooler and a furnace of CFB boiler were discussed in this paper. The research results showed that flowing...

Xiaofeng Lu; Yourong Li

2000-12-01T23:59:59.000Z

10

TRUTH & CONSEQUENCES... LOG 437/537: MODEL-THEORETIC SEMANTICS  

E-Print Network (OSTI)

TRUTH & CONSEQUENCES... LOG 437/537: MODEL-THEORETIC SEMANTICS Spring 2013, TT 11:45am-1:00pm Dr and compactness of first-order logic and introduce along the way the basic notions of structure, truth

Liu, Paul

11

Dual-Bed Gasification of Petcoke: Model Development and Validation  

Science Journals Connector (OSTI)

Dual-Bed Gasification of Petcoke: Model Development and Validation ... A series of sensitivity analyses is performed with regard to a conventional gasifier fed by petcoke, and the effects of residence time and oxygen/carbon mass ratio in the feed are investigated over three process variables: char conversion at the gasifier exit, temperature at the gasifier exit, and amount of useful syngas (H2 and CO) produced, in terms of N?m3 per ton of petcoke. ... Different from most literature publications, such as refs 5 and 6, where coal and/or petcoke gasification models are checked against available data, with respect to the syngas composition obtained, and to the process cold gas efficiency, one of the purposes of our paper is to correlate experimental data to a parameter that is important both for simulation and for reactor design: the value of the residence time of the gasifier. ...

Maria Sudiro; Carlos Zanella; Alberto Bertucco; Luigi Bressan; Marco Fontana

2010-01-15T23:59:59.000Z

12

Generalized Chaplygin gas model: Cosmological consequences and statefinder diagnosis  

E-Print Network (OSTI)

The generalized Chaplygin gas (GCG) model in spatially flat universe is investigated. The cosmological consequences led by GCG model including the evolution of EoS parameter, deceleration parameter and dimensionless Hubble parameter are calculated. We show that the GCG model behaves as a general quintessence model. The GCG model can also represent the pressureless CDM model at the early time and cosmological constant model at the late time. The dependency of transition from decelerated expansion to accelerated expansion on the parameters of model is investigated. The statefinder parameters $r$ and $s$ in this model are derived and the evolutionary trajectories in $s-r$ plane are plotted. Finally, based on current observational data, we plot the evolutionary trajectories in $s-r$ and $q-r$ planes for best fit values of the parameters of GCG model. It has been shown that although, there are similarities between GCG model and other forms of chaplygin gas in statefinder plane, but the distance of this model from the $\\Lambda$CDM fixed point in $s-r$ diagram is shorter compare with standard chaplygin gas model.

M. Malekjani; A. Khodam-Mohammadi; N. Nazari-Pooya

2011-03-09T23:59:59.000Z

13

The backflow cell model for fluidized bed catalytic reactors  

E-Print Network (OSTI)

that the backmixing of gas in a small fluidized bed with high length to diameter rati. o is relatively small. Hence, it was recommended. that reaction rate studies in fluidized bed reactors be correlated on the basis oi' piston flow~ neglecting mixing. Nay (19...) points out that the straight line obtained on plotting the results of Gilliland's ex- periment on a paper with semilogarithmic coordinates, can be used to characterize the residence time distribution introduced by Danckwerts (6). A steep slope, he...

Ganapathy, E. V

2012-06-07T23:59:59.000Z

14

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

15

Application of debris-bed dryout data to CONACS-1 modeling  

SciTech Connect

CONACS-1 (the first version of the DOE Containment Analysis Code System) which is currently under development requires extension of existing debris-bed dryout data to the wide range of conditions possible in an accident sequence. While there has been much effort on modeling of debris-bed dryout from first principles, there is no definitive model for beds of irregularly shaped particles of wide size distribution and for beds of varying heights. Existing debris-bed heat-transfer data with real materials are for the most part limited to dryout as a function of bed depth for adiabatic conditions of atmospheric pressure. These data must be extrapolated with the use of appropriate theoretical models based on experimentation with simulant materials to the ocnditions under consideration in the containment analysis. The data base selected for CONACS-1 is from measurements of dryout for beds of 100 to 1000 ..mu..m UO/sub 2/ with the sodium phase Joule heated. This particle size range which is typical for debris from fuel-coolant interactions is the most reasonable to use.

Gabor, J.D.; Cassulo, J.C.; Pedersen, D.R.

1982-01-01T23:59:59.000Z

16

Model-free adaptive control of supercritical circulating fluidized-bed boilers  

DOE Patents (OSTI)

A novel 3-Input-3-Output (3.times.3) Fuel-Air Ratio Model-Free Adaptive (MFA) controller is introduced, which can effectively control key process variables including Bed Temperature, Excess O2, and Furnace Negative Pressure of combustion processes of advanced boilers. A novel 7-input-7-output (7.times.7) MFA control system is also described for controlling a combined 3-Input-3-Output (3.times.3) process of Boiler-Turbine-Generator (BTG) units and a 5.times.5 CFB combustion process of advanced boilers. Those boilers include Circulating Fluidized-Bed (CFB) Boilers and Once-Through Supercritical Circulating Fluidized-Bed (OTSC CFB) Boilers.

Cheng, George Shu-Xing; Mulkey, Steven L

2014-12-16T23:59:59.000Z

17

Mechanical models of fracture reactivation and slip on bedding surfaces during folding of the asymmetric anticline at Sheep Mountain, Wyoming  

E-Print Network (OSTI)

Mechanical models of fracture reactivation and slip on bedding surfaces during folding June 2008 Accepted 5 June 2008 Available online 13 June 2008 Keywords: Fold Fracture reactivation Bed methods to investigate the reactivation of fractures (opening and shearing) and the development of bedding

Borja, Ronaldo I.

18

Packed bed thermal energy storage model – Generalized approach and experimental validation  

Science Journals Connector (OSTI)

Abstract Packed beds serve as thermal energy storages (TES) and heat exchangers (HEX) in different technological applications. In this paper, a general heterogeneous model of heat transfer in packed beds is developed. It is implemented by lumped element formulation in object-oriented modeling language Modelica and is successful validated with data sets taken from two different experiments reported in literature. The main advantages of the introduced model are the general, theory-based approach and the lumped element formulation in Modelica. The first point mentioned above should allow to simulate a packed bed TES/HEX without the necessity applying measured data for model calibration or to apply specific heat transfer correlations with restricted application. The second point establishes the possibility to integrate the TES/HEX model within plant models of larger scale without increasing the simulation time drastically.

Florian Opitz; Peter Treffinger

2014-01-01T23:59:59.000Z

19

Conversion model aids scale-up of mobil's fluid-bed MTG process  

Science Journals Connector (OSTI)

Mobil's fluid-bed Methanol-to-Gasoline (MTG) process was successfully scaled-up, from 0.04m diameter reactor, through 0.1m, to 0.6m diameter demonstration plant. Gas tracer responses in cold flow models were interpreted by a one-dimensional axial dispersion model, and combined with reaction kinetics to develop a conversion model.

M. Edwards; A. Avidan

1986-01-01T23:59:59.000Z

20

Mathematical modeling and heat transfer experiments for an annular bed methane-steam reformer  

SciTech Connect

A new type of catalytic reactor has been proposed for conducting endothermic chemical reactions. The reactor catalyst bed is in the form of a tubular reactor with an annular cross-section. Heat is supplied to the catalyst bed by countercurrent flowing gases on opposite sides of the annulus walls. This study consisted of the development of a mathematical model to describe the performance of an annular bed reactor employing the methane-steam reforming reaction for the production of hydrogen. The model is two-dimensional, and predicts both axial and radial temperature and concentration profiles throughout the reactor. The model was used to perform parameter sensitivity studies, reactor size optimization, and reactor scaleup.

Summers, W.A.

1986-01-01T23:59:59.000Z

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.


21

A model for turbulent hydraulic fracture and application to crack propagation at glacier beds  

E-Print Network (OSTI)

Click Here for Full Article A model for turbulent hydraulic fracture and application to crack suggest that fluidinduced hydraulic fracture of an ice sheet from its bed sometimes occurs quickly. Citation: Tsai, V. C., and J. R. Rice (2010), A model for turbulent hydraulic fracture and application

22

Modelling of trickle-bed reactors at high temperatures and pressures  

E-Print Network (OSTI)

that it is very difficult to reproduce the same flow pattern from bed to bed, Lee and Smith present a criterion for negligible inter- and intraphase transport effects. For exothermic reactions, this criterion is (RL/k C )(p /s ) & P/(1-1)) b L L p p (22.... This is valid for reactions such as hydrodesulfurization and hydrodenitrogenation, which are only slightly exothermic. Most models assume a non-volatile liquid phase. Since the models reviewed were tested against reaction systems at ambient conditions...

Collins, George Michael

1983-01-01T23:59:59.000Z

23

Ex-plant consequence assessment for NUREG-1150: Models, typical results, uncertainties  

SciTech Connect

The assessment of ex-plant consequences for NUREG-1150 source terms was performed using the MELCOR Accident Consequence Code System (MACCS). This paper will briefly discuss the following elements of MACCS consequence calculations: input data, phenomena modeled, computational framework, typical results, controlling phenomena, and uncertainties. Wherever possible, NUREG-1150 results will be used to illustrate the discussion. 28 refs., 14 figs., 6 tabs.

Sprung, J.L.

1987-01-01T23:59:59.000Z

24

Modeling Process Characteristics and Performance of Fixed and Fluidized Bed Regenerative Thermal Oxidizer  

Science Journals Connector (OSTI)

Modeling Process Characteristics and Performance of Fixed and Fluidized Bed Regenerative Thermal Oxidizer ... (7)?Cheng, W.-H.; Chou, M.-S.; Lee, W.-S.; Huang, B.-J. Applications of Low-Temperature Regenerative Thermal Oxidizers to Treat Volatile Organic Compounds. ...

Pietropaolo Morrone; Francesco P. Di Maio; Alberto Di Renzo; Mario Amelio

2006-05-26T23:59:59.000Z

25

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

SciTech Connect

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

26

Modeling for Anaerobic Fixed-Bed Biofilm Reactors  

SciTech Connect

The specific objectives of this research were: 1. to develop an equilibrium model for chemical aspects of anaerobic reactors; 2. to modify the equilibrium model for non-equilibrium conditions; 3. to incorporate the existing biofilm models into the models above to study the biological and chemical behavior of the fixed-film anaerobic reactors; 4. to experimentally verify the validity of these models; 5. to investigate the biomass-holding ability of difference packing materials for establishing reactor design criteria.

Liu, B. Y. M.; Pfeffer, J. T.

1989-06-01T23:59:59.000Z

27

Simulation and modeling of atmospheric fluidized bed combustors for high sulfur coals  

SciTech Connect

The principal issues in modeling atmospheric fluidized bed combustors (AFBC) are described using the Oak Ridge National Laboratory (ORNL) - Tennessee Valley Authority (TVA) steady state AFBC model as an example. Comparisons are made between model predictions of boiler performance with experimental data from the TVA 20 MW(e) AFBC pilot plant data. Recent FBC models are briefly reviewed and compared with the ORNL-TVA model. The paper also describes the ongoing effort at TVA on transient modeling of AFBC and presents some preliminary results from the TVA AFBC transient model.

Krishnan, R.P.; Daw, C.S.; Byrd, J.; Zielke, R.; Wells, J.W.

1986-01-01T23:59:59.000Z

28

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

29

Computational fluid dynamics modeling of coal gasification in a pressurized spout-fluid bed  

SciTech Connect

Computational fluid dynamics (CFD) modeling, which has recently proven to be an effective means of analysis and optimization of energy-conversion processes, has been extended to coal gasification in this paper. A 3D mathematical model has been developed to simulate the coal gasification process in a pressurized spout-fluid bed. This CFD model is composed of gas-solid hydrodynamics, coal pyrolysis, char gasification, and gas phase reaction submodels. The rates of heterogeneous reactions are determined by combining Arrhenius rate and diffusion rate. The homogeneous reactions of gas phase can be treated as secondary reactions. A comparison of the calculated and experimental data shows that most gasification performance parameters can be predicted accurately. This good agreement indicates that CFD modeling can be used for complex fluidized beds coal gasification processes. 37 refs., 7 figs., 5 tabs.

Zhongyi Deng; Rui Xiao; Baosheng Jin; He Huang; Laihong Shen; Qilei Song; Qianjun Li [Southeast University, Nanjing (China). Key Laboratory of Clean Coal Power Generation and Combustion Technology of Ministry of Education

2008-05-15T23:59:59.000Z

30

A fixed-bed reactor modeling study on the methanation of CO2  

Science Journals Connector (OSTI)

Abstract The methanation of carbon dioxide has gained renewed interest during the last years as a possible technology to synthesize a feasible chemical energy carrier. This modeling study aims at a basic understanding of the aspects relevant for designing an externally cooled fixed-bed reactor for the methanation of a pure, stoichiometric feed gas. It is shown that the reaction rates and the exothermicity (?H° = ?165 kJ/mol) prevent a fixed-bed reactor of technical dimensions to be operated at high conversions without runaway of the reactor. The model predictions of differently detailed pseudo-homogeneous reactor models and a heterogeneous reactor model where the intraparticle transport of mass is described according to a dusty-gas approach are compared to assess the needed level of detail in terms of modeling the heat transfer, fluid flow characteristics and transport resistances on the pellet scale. Under specific conditions, intraparticle mass transfer and external heat transfer need to be considered for describing the temperature and concentration profiles adequately. The study is completed by modeling a fixed-bed membrane reactor as an example of a structured reactor that offers improved temperature control by separated and controlled feeding of hydrogen and carbon dioxide.

David Schlereth; Olaf Hinrichsen

2014-01-01T23:59:59.000Z

31

Shallow Water Model which Admit a Propagation of Shocks over a Dry Bed  

Science Journals Connector (OSTI)

A method for modeling the propagation of hydraulic bores over a dry bed using the first approximation of shallow water theory is proposed. The method is based on a modified conservation law of total momentum that takes into account the concentrated momentum losses due to the formation of local turbulent vortex structures in the fluid surface layer at a hydraulic bore front. A quantitative estimate of these losses is obtained by deriving the shallow water equations from the Navier?Stokes equations with allowance for viscosity which has a rapidly increasing effect in the turbulent flow regions described in theory as shocks. A comparative analysis is performed for the modeling of the dam?break problem experimentally and theoretically by the help of the classical and modified shallow water equations. Numerical results are presented for the propagation over a dry bed of a two?dimensional shock arising in a partial dam break in a channel with sloping bottom in the lower pool.

2010-01-01T23:59:59.000Z

32

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

33

EXPERIMENT AND NEURAL NETWORK MODEL OF PRIMARY FRAGMENTATION OF OIL SHALE IN FLUIDIZED BED  

E-Print Network (OSTI)

that the fluidized bed temperature is an important factor of primary fragmentation of oil shale, and

Zhigang Cui; Xiangxin Han; Xiumin Jiang; Jianguo Liu

34

MODEL FOR DETERMINING THE EFFECTIVE THERMAL CONDUCTIVITY OF PARTICLE BEDS WITH HIGH SOLID-TO-GAS THERMAL  

E-Print Network (OSTI)

MODEL FOR DETERMINING THE EFFECTIVE THERMAL CONDUCTIVITY OF PARTICLE BEDS WITH HIGH SOLID-TO-GAS- to-gas conductivity ratio (such as Be and He). The model has the capability of accounting with high solid-to-gas thermal conductivity ratios. This paper summarizes this modeling effort. Model

Abdou, Mohamed

35

Simulation and experimental verification of a hydrodynamic model for a dual fluidized Bed gasifier  

Science Journals Connector (OSTI)

Abstract We propose a revised 2-D energy-minimization multi-scale (EMMS) model based on a two-fluid model to perform the hydrodynamic character analysis of a pilot-scale full-loop dual fluidized bed gasifier (DFBG), which consists of a riser, a cyclone with a down-comer, a bubbling fluidized bed (BFB), and a loop-seal. The EMMS model is used to analyze the interaction force between the gas and solid phases in the DFBG. For comparison, O'Brien & Syamlal's drag heterogeneous force coefficient correction is also analyzed. The instantaneous particle profiles are described by the calculated results. The local and overall flow characteristics are determined by the solids concentration under different fluidization conditions. The effects of the gas velocities in the riser and the recycle gas velocities in the U loop seal on the axial solids concentration and solids circulation profiles, as well as the flow heterogeneity in sub-zones of the riser are investigated. The numerical results are in good agreement with the experimental data, indicating that the EMMS model is appropriate to simulate the heterogeneous gas–solids two-phase flow in DFBG.

Xueyao Wang; Jing Lei; Xiang Xu; Zhengzhong Ma; Yunhan Xiao

2014-01-01T23:59:59.000Z

36

A model of fracture nucleation, growth and arrest, and consequences for fracture density and scaling  

E-Print Network (OSTI)

A model of fracture nucleation, growth and arrest, and consequences for fracture density; accepted 1 February 2013; published 25 April 2013. [1] In order to improve discrete fracture network (DFN a new DFN modeling based on the evolution of fracture network formation--nucleation, growth, and arrest

Boyer, Edmond

37

Modeling of Sediment Bed Behavior for Critical Velocity in Horizontal Piping  

SciTech Connect

This paper compares results from a predictive tool for modeling transport of a multiphase mixture (solids in a liquid) in a pipeline, (up to and including plugging) with experiments performed to support the Hanford site’s Waste Treatment and Immobilization Plant (WTP). The treatment of high-level waste at the DOE Office of River Protection’s WTP will involve the transfer of high solid content suspensions through pipelines. Pipeline plugging was identified as a significant potential issue by a panel of external experts. In response to their concerns an experimental effort was initiated at PNNL to determine the critical velocities for a variety of operating conditions. A computational method has been developed to predict the dynamic behavior of a sediment bed in response to the surrounding suspension flow. The flow field is modeled using a lattice kinetics method, similar to the lattice Boltzmann method, which scales very well on highly parallel computers. Turbulent quantities are calculated using a k-epsilon RANS model. This work is part of a larger effort to develop a process simulation capability for a wide range of applications. Solids are represented using two different continuum fields. The suspended solids are treated as passive scalars in the flow field, including terms for hindered settling and Brownian diffusion. Normal stresses created by the irreversible collisions of particles during shearing are added to the pressure tensor. The sediment bed interface is represented using a continuum phase field with a diffuse interface. The bed may change with time due to settling, erosion and deposition through convection. The erosion rates are calculated using the local shear stress obtained from the turbulence model. The method is compared with data from the PNNL pipeline experiments conducted at PNNL (Poloski et al. 2008). The experimental flow loop consists of 3-inch schedule 40 piping with instrumentation for determining flow rate and pressure gradient. The simulant test particles ranged in density from 2.5 to 8 g/cc while the nominal particle size ranged from 10 to 100 ?m. At the beginning of each test, the slurry flow velocity was nominally set to 8 ft/sec. The flow was incrementally ramped down, and a steady-state pressure gradient was obtained at each flow condition. A rise in pressure gradient as the flow rate drops indicates that the pipe cross-sectional area is beginning to fill with sediment. This point is referred to as the “critical velocity”. Visualization information is provided using Electrical Resistance Tomography (ERT). The paper will show favorable comparison of results with data.

Rector, David R.; Stewart, Mark L.; Poloski, Adam P.

2009-10-01T23:59:59.000Z

38

Modeling of fixed bed methanation reactor for syngas production: Operating window and performance characteristics  

Science Journals Connector (OSTI)

Abstract The present work focuses on the development of phenomenological model for the bio-syngas to methane conversion process. One dimensional heterogeneous and pseudo-homogeneous model were simulated for a typical pilot plant scale fixed bed methanator processing 55 mol/h of CO (total molar flow rate of 310 mol/h) with inlet composition of H2/CO = 3, CO2/CO = 1, CH4/CO = 0.5 at 550 K and 1 atm. Performance of the fixed bed reactor at different operating conditions like CO2/CO ratio, H2/CO ratio, effect of H2O in the feed was studied. It was found that for feeds that were not pre-enriched with hydrogen, presence of water and water gas shift activity was found to decrease the catalyst inventory substantially. CO2 in the inlet feed stream would help to decrease the temperature due to dilution effect and more importantly, can be chosen to maximize methane yield per mole of CO converted. Further, the model was simulated to predict the performance characteristics of reactor with a mixture containing two types of catalyst, one of them being specifically added to increase H2/CO ratio in feed through water gas shift reaction. The work also laid the importance of incorporating pore diffusion and external mass transfer locally in the computation of actual catalyst inventory and reactor volume. The work was useful in selection of operating window and assessing the various viable options for an industrial reactor. The model developed will serve in selection of operability window for commercialization of substitute natural gas synthesis (SNG) process.

Naren Rajan Parlikkad; Stéphane Chambrey; Pascal Fongarland; Nouria Fatah; Andrei Khodakov; Sandra Capela; Olivier Guerrini

2013-01-01T23:59:59.000Z

39

Modeling of fluidized-bed combustion of coal: Phase II, final reports. Volume 1. Model evolution and development  

SciTech Connect

The Energy Laboratory of the Massachusetts Institute of Technology (M.I.T.), under Department of Energy (DOE) sponsorship, has been engaged in the development of a comprehensive mechanistic model of Fluidized Bed Combustors (FBC). The primary aims of this modeling effort are the generation and to the extent possible, validation of an analytical framework for the design and scale-up of fluidized bed combustors. In parallel with this modeling effort, M.I.T. also embarked upon the development of an FBC-Data Base Management System (FBC-DBMS) aimed at facilitating the coordination, interpretation and utilization of the experimental data that are or will become available from diverse sources, as well as in the identification of areas of large uncertainty or having a paucity of experimental results. The synergistic operation of the FBC-Model and FBC-Data Base promises to offer a powerful tool for the design and optimization of FBC's and represents the ultimate goal of the M.I.T. effort. The modeling effort was initially focused upon evaluation and application of state-of-the-art models. The initial system model was divided into five basic components: fluid dynamics, combustion, sulfur capture, heat transfer and emissions. Due to the technical complexity of modeling FBC operation and the initial primitive nature of models for these components, it was deemed necessary to be able to incorporate evolutionary improvements in understanding and correlating FBC phenomena: the M.I.T. system model is, therefore, modular in nature, i.e., each sub-model can be replaced by an updated or equivalent sub-model without necessitating reprogramming of the entire system model.

Louis, J.F.; Tung, S.E.

1980-10-01T23:59:59.000Z

40

UNDERSTANDING THE GENETIC CONSEQUENCES OF ENVIRONMENTAL TOXICANT EXPOSURE: CHERNOBYL AS A MODEL SYSTEM  

E-Print Network (OSTI)

UNDERSTANDING THE GENETIC CONSEQUENCES OF ENVIRONMENTAL TOXICANT EXPOSURE: CHERNOBYL AS A MODEL to Chernobyl radiation. Our results suggest that genetic diversity in radioactive regions of Ukraine to elucidate the effects of toxicant exposure. Keywords--Chernobyl Bank vole Population genetics Comparative

Baker, Robert 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.


41

Process modeling and thermodynamic analysis of Lurgi fixed-bed coal gasifier in an SNG plant  

Science Journals Connector (OSTI)

Abstract This paper presents a comprehensive steady state kinetic model of a commercial-scale pressurized Lurgi fixed-bed dry bottom coal gasifier. The model is developed using the simulator Aspen Plus. Five sequential modules: drying zone, pyrolysis zone, gasification zone, combustion zone and overall heat recovery unit, are considered in the main process model. A non-linear programming (NLP) model is employed to estimate the pyrolysis products, which include char, coal gas and high-weight hydrocarbons/distillable liquids (tar, phenol, naphtha and oil). To accelerate solution convergence, an external FORTRAN subroutine is used to simulate the kinetics of the combustion and gasification processes which are formulated in terms of a series of continuous stirred-tank reactors. The model is validated with industrial data. The effects of two key operating parameters, namely oxygen/coal mass ratio and steam/coal mass ratio, on the thermodynamic efficiencies of the Lurgi gasifier and the gasification system as a whole are investigated via extensive simulation studies.

Chang He; Xiao Feng; Khim Hoong Chu

2013-01-01T23:59:59.000Z

42

Modeling of coal bed methane (CBM) production and CO2 sequestration in coal seams  

Science Journals Connector (OSTI)

A mathematical model was developed to predict the coal bed methane (CBM) production and carbon dioxide (CO2) sequestration in a coal seam accounting for the coal seam properties. The model predictions showed that, for a CBM production and dewatering process, the pressure could be reduced from 15.17 MPa to 1.56 MPa and the gas saturation increased up to 50% in 30 years for a 5.4 × 105 m2 of coal formation. For the CO2 sequestration process, the model prediction showed that the CO2 injection rate was first reduced and then slightly recovered over 3 to 13 years of injection, which was also evidenced by the actual in seam data. The model predictions indicated that the sweeping of the water in front of the CO2 flood in the cleat porosity could be important on the loss of injectivity. Further model predictions suggested that the injection rate of CO2 could be about 11 × 103 m3 per day; the injected CO2 would reach the production well, which was separated from the injection well by 826 m, in about 30 years. During this period, about 160 × 106 m3 of CO2 could be stored within a 21.4 × 105 m2 of coal seam with a thickness of 3 m.

Ekrem Ozdemir

2009-01-01T23:59:59.000Z

43

Equivalent Reactor Network Model for Simulating the Air Gasification of Polyethylene in a Conical Spouted Bed Gasifier  

Science Journals Connector (OSTI)

Equivalent Reactor Network Model for Simulating the Air Gasification of Polyethylene in a Conical Spouted Bed Gasifier ... Plastic waste treatment technologies, apart from chemical recycling, constitute a growing social problem, such as the loss of natural resources, the depletion of landfill space, and the environmental pollution. ...

Yupeng Du; Qi Yang; Abdallah S. Berrouk; Chaohe Yang; Ahmed S. Al Shoaibi

2014-11-06T23:59:59.000Z

44

Laboratory Experiments and Hydrodynamic Modeling of a Bed Leveler Used to Level the Bottom of Ship Channels after Dredging  

E-Print Network (OSTI)

This study was conducted to ascertain the impacts of bed leveling, following ship channel dredging operations, and to also investigate the hydrodynamic flow field around box bed levelers. Laboratory experiments were conducted with bed levelers...

Paul, Ephraim Udo

2011-02-22T23:59:59.000Z

45

Consequence modeling for nuclear weapons probabilistic cost/benefit analyses of safety retrofits  

SciTech Connect

The consequence models used in former studies of costs and benefits of enhanced safety retrofits are considered for (1) fuel fires; (2) non-nuclear detonations; and, (3) unintended nuclear detonations. Estimates of consequences were made using a representative accident location, i.e., an assumed mixed suburban-rural site. We have explicitly quantified land- use impacts and human-health effects (e.g. , prompt fatalities, prompt injuries, latent cancer fatalities, low- levels of radiation exposure, and clean-up areas). Uncertainty in the wind direction is quantified and used in a Monte Carlo calculation to estimate a range of results for a fuel fire with uncertain respirable amounts of released Pu. We define a nuclear source term and discuss damage levels of concern. Ranges of damages are estimated by quantifying health impacts and property damages. We discuss our dispersal and prompt effects models in some detail. The models used to loft the Pu and fission products and their particle sizes are emphasized.

Harvey, T.F.; Peters, L.; Serduke, F.J.D.; Hall, C.; Stephens, D.R.

1998-01-01T23:59:59.000Z

46

Radiological Health Effects Models for Nuclear Power Plant Accident Consequence Analysis — An Update (1990)  

Science Journals Connector (OSTI)

Technical Paper / Advances in Reactor Accident Consequence Assessment / Radiation Biology and Environment

John S. Evans

47

A coupled transport and solid mechanics formulation with improved reaction kinetics parameters for modeling oxidation and decomposition in a uranium hydride bed.  

SciTech Connect

Modeling of reacting flows in porous media has become particularly important with the increased interest in hydrogen solid-storage beds. An advanced type of storage bed has been proposed that utilizes oxidation of uranium hydride to heat and decompose the hydride, releasing the hydrogen. To reduce the cost and time required to develop these systems experimentally, a valid computational model is required that simulates the reaction of uranium hydride and oxygen gas in a hydrogen storage bed using multiphysics finite element modeling. This SAND report discusses the advancements made in FY12 (since our last SAND report SAND2011-6939) to the model developed as a part of an ASC-P&EM project to address the shortcomings of the previous model. The model considers chemical reactions, heat transport, and mass transport within a hydride bed. Previously, the time-varying permeability and porosity were considered uniform. This led to discrepancies between the simulated results and experimental measurements. In this work, the effects of non-uniform changes in permeability and porosity due to phase and thermal expansion are accounted for. These expansions result in mechanical stresses that lead to bed deformation. To describe this, a simplified solid mechanics model for the local variation of permeability and porosity as a function of the local bed deformation is developed. By using this solid mechanics model, the agreement between our reacting bed model and the experimental data is improved. Additionally, more accurate uranium hydride oxidation kinetics parameters are obtained by fitting the experimental results from a pure uranium hydride oxidation measurement to the ones obtained from the coupled transport-solid mechanics model. Finally, the coupled transport-solid mechanics model governing equations and boundary conditions are summarized and recommendations are made for further development of ARIA and other Sandia codes in order for them to sufficiently implement the model.

Salloum, Maher N.; Shugard, Andrew D.; Kanouff, Michael P.; Gharagozloo, Patricia E.

2013-03-01T23:59:59.000Z

48

Modeling and Simulation of an Open Core Down-Draft Moving Bed Rice Husk Gasifier  

Science Journals Connector (OSTI)

Recently we developed a new type of open core moving bed rice husk gasifier for small scale application. Here, we...T rate of the rice husk was varied in the range of 50-300 kg/m2.h. and the air velocity from 50 ...

R. K. Manurung; A. A. C. M. Beenackers

1993-01-01T23:59:59.000Z

49

Modeling and Experimental Studies of Mercury Oxidation and Adsorption in a Fixed-Bed and Entrained-Flow Reactor  

SciTech Connect

This report presents experimental and modeling mercury oxidation and adsorption data. Fixed-bed and single-particle models of mercury adsorption were developed. The experimental data were obtained with two reactors: a 300-W, methane-fired, tubular, quartz-lined reactor for studying homogeneous oxidation reactions and a fixed-bed reactor, also of quartz, for studying heterogeneous reactions. The latter was attached to the exit of the former to provide realistic combustion gases. The fixed-bed reactor contained one gram of coconut-shell carbon and remained at a temperature of 150oC. All methane, air, SO2, and halogen species were introduced through the burner to produce a radical pool representative of real combustion systems. A Tekran 2537A Analyzer coupled with a wet conditioning system provided speciated mercury concentrations. At 150?C and in the absence of HCl or HBr, the mercury uptake was about 20%. The addition of 50 ppm HCl caused complete capture of all elemental and oxidized mercury species. In the absence of halogens, SO2 increased the mercury adsorption efficiency to up to 30 percent. The extent of adsorption decreased with increasing SO2 concentration when halogens were present. Increasing the HCl concentration to 100 ppm lessened the effect of SO2. The fixed-bed model incorporates Langmuir adsorption kinetics and was developed to predict adsorption of elemental mercury and the effect of multiple flue gas components. This model neglects intraparticle diffusional resistances and is only applicable to pulverized carbon sorbents. It roughly describes experimental data from the literature. The current version includes the ability to account for competitive adsorption between mercury, SO2, and NO2. The single particle model simulates in-flight sorbent capture of elemental mercury. This model was developed to include Langmuir and Freundlich isotherms, rate equations, sorbent feed rate, and intraparticle diffusion. The Freundlich isotherm more accurately described in-flight mercury capture. Using these parameters, very little intraparticle diffusion was evident. Consistent with other data, smaller particles resulted in higher mercury uptake due to available surface area. Therefore, it is important to capture the particle size distribution in the model. At typical full-scale sorbent feed rates, the calculations underpredicted adsorption, suggesting that wall effects can account for as much as 50 percent of the removal, making it an important factor in entrained-mercury adsorption models.

Buitrago, Paula A; Morrill, Mike; Lighty, JoAnn S; Silcox, Geoffrey D

2014-08-20T23:59:59.000Z

50

Effect of equation of state on prediction of trickle bed reactor model performance  

E-Print Network (OSTI)

of outlet conversion and a temperature profile. In Order to obtain initial guesses for the nonlinear regression a grid search is performed (Ray, 1982) with the assumption that the relationship between temperature and conversion is linear. The initial.... Wrth the initial guesses for and E and the linear temperature conversion assumption the Marquardt method is used to compute a new E and k . At this point the first iteration is complete. These kinetic parameters are then inputed into the trickle bed...

Netherland, Donald Wayne

1985-01-01T23:59:59.000Z

51

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

SciTech Connect

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

52

Modeling and simulation of co-gasification of coal and petcoke in a bubbling fluidized bed coal gasifier  

Science Journals Connector (OSTI)

In this work we discuss the modeling and simulation of a fluidized bed coal gasifier which uses a mixture of coal and petcoke as its feed. A two phase model consisting of the bubble phase and the emulsion phase is used to describe the coal gasification process. We consider a non-isothermal model taking into account the effect of four heterogeneous reactions and four homogeneous reactions. We analyse the effect of various operating parameters such as composition of feed, location of feed point and ash content on the performance of the gasifier. The results of predictions of the simulations have been found to be in good agreement with the experimental results in the literature. It has been found that increase in petcoke content in the feed mixture tends to lower the efficiency and carbon conversion but increases the amount of syngas produced. Also, from the simulations, it has been found that increase in ash content of coal decreases the carbon conversion. We have concluded that the feed point of the solids should be above the point where O2 that is present in the bed gets exhausted, in order to obtain the maximum carbon conversion and efficiency.

Anshul Goyal; S. Pushpavanam; Ravi Kumar Voolapalli

2010-01-01T23:59:59.000Z

53

Modeling overpressures in sedimentary basins: Consequences for permeability and rheology of shales, and petroleum expulsion efficiency  

SciTech Connect

The prediction of overpressures using Institut Francais du Petrole's 2-D numerical model TEMISPACK is applied to several provinces of the world. In the Paris basin, France, normally pressured Liassic shales are shown to have permeabilities around a microdarcy, independently confirmed by laboratory measurements. In contrast, in the Norway section of the North Sea, Williston Basin, Canada, Gulf Coast, and in the Mahakam delta, observed overpressures of 10-50 MPa are consistently modeled with shale permeabilities around 1-10 nanodarcys. This theoretical value fits well with the lowest permeability measured in compacted shales. For these basins, compaction disequilibrium was found to explain most (>85%) of the overpressures. The only exception was the Williston basin in which overpressures observed in the organic-rich Bakken shales are entirely due to hydrocarbon generation. In Mahakam delta, the rheology of shales is nonlinear, i.e., the strength of shales increases rapidly with death. Consequently, shale compaction cannot be described by the linear behavior often assumed in hydrology. In the absence of fault barriers, numerical simulations and geological evidence suggest that overpressured source rocks have low or very low expulsion efficiency, irrespective of their organic content. However, shales with a permeability on the order of a microdarcy do not hinder petroleum migration.

Burrus, J.; Schneider, F.; Wolf, S. (Institut Francais du Petrole, Rueil-Malmaison (France))

1994-07-01T23:59:59.000Z

54

E-Print Network 3.0 - accident consequence model Sample Search...  

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

2 Why System Safety Professionals Should Read Accident Reports C. M. Holloway*, C. W. Johnson Summary: accidents in general; an increased understanding of the consequences of...

55

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

56

Bed management in a Critical Care Unit  

Science Journals Connector (OSTI)

......with the variability in demand for the services that...adequate facilities on demand can lead to serious consequences...how improvements in bed management may be achieved by distinguishing...task of ensuring that demand for hospital services...equipment at each bed-side is around 60,000......

J. D. Griffiths; V. Knight; I. Komenda

2013-04-01T23:59:59.000Z

57

Modelling Mixed Bed Ion Exchange Kinetics for Removal of Trace Levels of Divalent Cations in Ultrapure Water  

SciTech Connect

Ion exchanger resin fluid film mass transfer coefficients and the ionic diffusivities from which they are derived are often measured by use of ion exchange resin columns. Such tests, usually run dynamically using short resin beds, are often performed using relatively high (ppm) concentrations of ions to accurately measure output concentrations as a function of flow rate. The testing described herein was performed to determine fluid film ionic diffusivities for cationic concentrations typical of ultrapure water ({le}ppb levels) containing ppm levels of ammonia. Effective ionic diffusivities at these low ionic concentrations and high pHs were needed to complete a computer model (SIMIX) to be used in ion exchange simulations. SIMIX is a generalized multicomponent ion exchange model designed to simulate the removal of divalent cations from ultrapure water.

B. Widman

2003-01-01T23:59:59.000Z

58

Experimental and modeling study of catalytic steam reforming of methane mixture with propylene in a packed bed reactor  

Science Journals Connector (OSTI)

Abstract Producer gas from biomass gasification contains mainly hydrogen, carbon dioxide, carbon monoxide, methane and some other low molecular hydrocarbons like propylene. This paper reports mathematical simulation and experimental study of steam reforming of methane mixture with propylene in a packed bed reactor filled with nickel based catalysts. Due to the high heat input through the reformer tube wall and the endothermic reforming reactions, a two-dimensional pseudo-heterogeneous model that takes into account the diffusion reaction phenomena in gas phase as well as inside the catalyst particles has been used to represent temperature distribution and species concentration within the reactor. Steam reforming of propylene is faster and more selective than methane and it is shown that addition of propylene to the methane steam mixture reduces the conversion of methane. The obtained results play a key role in optimization and design of a commercial reactor.

Parham Sadooghi; Reinhard Rauch

2014-01-01T23:59:59.000Z

59

Some consequences  

Science Journals Connector (OSTI)

May 3, 1983 ... Small-scale nutrient patchiness: Some consequences and a new encounter mechanism'. Donald Scavia and Gary L. Fahnenstiel. Great Lakes ...

2000-02-09T23:59:59.000Z

60

2-D Modeling of thermo-kinetics coupled with heat and mass transfer in the reduction zone of a fixed bed downdraft biomass gasifier  

Science Journals Connector (OSTI)

Abstract A two dimensional modeling is developed in the reduction zone of a fixed bed downdraft biomass gasifier based on mass, energy and momentum conservation equations written for the solid and fluid phases and coupled with chemical kinetics. Kinetics parameters are derived from previous works and an effectiveness factor was used in the reaction rate correlation to quantify the mass transfer resistance in the bed. The obtained numerical results are compared with experimental and numerical data from literature and a reasonable agreement is observed. Fields of temperature, gaseous concentrations are investigated for the two-dimensional domain. Results show that the solid and fluid inlet temperatures to the reduction zone and the reactivity of the bio-char including the effectiveness factor are the main variables affecting the conversion of char to syngas in the gasification zone of the fixed bed reactor.

Mohamed Ali Masmoudi; Melik Sahraoui; Najla Grioui; Kamel Halouani

2014-01-01T23:59:59.000Z

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.


61

A model on chemical looping combustion of methane in a bubbling fluidized-bed process  

Science Journals Connector (OSTI)

We developed a mathematical model to discuss the performance of chemical looping combustion (CLC) of methane in continuous bubbling ... The present model agrees reasonably well with the combustion efficiency meas...

Jeong-Hoo Choi; Pil Sang Youn; Djamila Brahimi…

2012-06-01T23:59:59.000Z

62

A Computational Model for Pyrolysis, Heat Transfer, and Combustion in a Fixed-bed Waste Gasifier.  

E-Print Network (OSTI)

??The overarching goal of the study presented in this dissertation is to develop a predictive computational model that can describe the detailed chemical and physical… (more)

Tsai, Chung-Yin

2011-01-01T23:59:59.000Z

63

Model for deposition of bedded halite in a shallow shelf setting, San Andres Formation, Palo Duro Basin, Texas panhandle  

SciTech Connect

Existing depositional models for evaporites do not adequately describe facies relationships, halite fabrics, and trace element geochemistry of halite from the Permian San Andres Formation. Interbedding of anhydritic halite and mudstone with disrupted bedding records alternation between marine-dominated brine pool and subaerial environments. Chevron structures and hopper crystal cumulates in the halite indicate subaqueous deposition. Abundant anhydrite partings within halite, which thicken and become interbedded with marine shelf carbonates to the south, demonstrate the facies equivalence and physical connection of evaporite and marine environments. Maintenance of marine character in trace element profiles through halite sequences documents the episodic influx of marine water. Haloturbated structure in mudstone interbeds within the halite is produced by displacive growth of halite within mudstone and dissolution and collapse of this halite as ground-water chemistry fluctuates in response to conditions of alternating desiccation and wetting. Karst features cutting the halite also imply subaerial exposure. Mapping of the fine-scale sedimentary structures, geochemical signature, and insoluble component mineralogy of halite sequences indicates that the brine pool environment extended over areas in excess of 100 km/sup 2/. Sabkha, salina, playa, and deep water basin models of halite-precipitating environments do not satisfactorily describe the shallow marine shelf depositional environment of the San Andres halite.

Hovorka, S.D.

1985-01-01T23:59:59.000Z

64

Modelling the economic and social consequences of drought under future projections of climate change  

E-Print Network (OSTI)

, China, Ethiopia, India, Spain/Portugal and the USA. Future projections of drought magnitude for 2003-2050 were modelled using the integrated assessment model CIAS (Community Integrated Assessment System), for a range of climate and emission scenarios...

Jenkins, Katie L.

2012-01-10T23:59:59.000Z

65

Consequence analysis of aqueous ammonia spills using an improved liquid pool evaporation model  

E-Print Network (OSTI)

of Acrolein released into air.................................................................98 x LIST OF TABLES Page Table 1. Assumptions for modeling scenarios...

Raghunathan, Vijay

2005-02-17T23:59:59.000Z

66

Advances in National Capabilities for Consequence Assessment Modeling of Airborne Hazards  

SciTech Connect

This paper describes ongoing advancement of airborne hazard modeling capabilities in support of multiple agencies through the National Atmospheric Release Advisory Center (NARAC) and the Interagency Atmospheric Modeling and Atmospheric Assessment Center (IMAAC). A suite of software tools developed by Lawrence Livermore National Laboratory (LLNL) and collaborating organizations includes simple stand-alone, local-scale plume modeling tools for end user's computers, Web- and Internet-based software to access advanced 3-D flow and atmospheric dispersion modeling tools and expert analysis from the national center at LLNL, and state-of-the-science high-resolution urban models and event reconstruction capabilities.

Nasstrom, J; Sugiyama, G; Foster, K; Larsen, S; Kosovic, B; Eme, B; Walker, H; Goldstein, P; Lundquist, J; Pobanz, B; Fulton, J

2007-11-26T23:59:59.000Z

67

Numerical simulations of particle growth in a silicon-CVD fluidized bed reactor via a CFD–PBM coupled model  

Science Journals Connector (OSTI)

Abstract A Eulerian–Eulerian two-fluid model coupled with population balance equations was applied to simulate the evolution of silicon particle growth by chemical vapor deposition of silane pyrolysis in a three-dimensional slugging fluidized bed reactor using FLUENT. The simulation of the particle growth considering surface deposition, cluster scavenging, aggregation and wall deposition was carried out after the verification of flow and heat transfer characteristics based on the well-accepted correlations. The results showed that the scavenging effect was responsible for the particle growth, and the growth rate agreed well with the experimental data by Tejero-Ezpeleta et al. (2004) when the scavenging factor was set to 0.1 under the condition of 923 K and atmospheric pressure. Moreover, the formation of light silicon hydrides by silane homogeneous pyrolysis in the dilute phase was also investigated in the form of CHMEKIN mechanism, which showed that disilane turned to be the main silicon hydride and the silane conversion was underestimated by 12.5%. Finally, the effects of operating conditions on the growth rate were studied in detail with the observation of defluidization phenomenon during the evolution of particle growth.

Si-Si Liu; Wen-De Xiao

2014-01-01T23:59:59.000Z

68

Air–steam gasification of biomass in fluidized bed with CO2 absorption: A kinetic model for performance prediction  

Science Journals Connector (OSTI)

Abstract Significance of decarbonized energy production in the context of a foreseeable hydrogen economy has called for the need of extensive research in biomass gasification-carbon dioxide capture technique. The feasibility of calcium oxide as a sorbent for CO2 in syngas is studied for air–steam fluidized bed (FB) gasification through a reaction kinetic modeling approach. Arrhenius rate equations are employed for primary and secondary pyrolysis, gasification and carbonation reactions. Devolatilization product yields are predicted using available correlations for FB gasification and cracking of tar is incorporated. Parametric performance analysis is carried out highlighting the significance of equivalence ratio (ER), gasification temperature, steam to biomass ratio (SBR) and sorbent to biomass ratio (SOBR). The effects of various gasifying media on H2 concentration and performance indicators such as heating value and efficiencies are analyzed. The simulation results are validated with the reported experimental results. The kinetic study reveals that air–steam gasification significantly reduces the unreacted steam but at a lower H2 concentration than steam gasification. A maximum of 53% hydrogen rich gas mixture is predicted at ER = 0.25, SBR = 1.5, SOBR = 2.7 and 1000 K. Against fossil fuel expended steam gasification, pure oxygen gasification is suggested by the study.

C.C. Sreejith; C. Muraleedharan; P. Arun

2015-01-01T23:59:59.000Z

69

Modeling of the rock bed thermal energy storage system of a combined cycle solar thermal power plant in South Africa  

Science Journals Connector (OSTI)

Abstract A thermocline-based rock bed thermal energy storage system potentially offers a cheap and simple way of achieving dispatchability in an air-cooled central receiver CSP plant. In order to efficiently match heliostat field size, storage dimensions, back-up fuel consumption and turbine sizes for non-stop power generation and economic feasibility, year-long power plant simulations have to be run. This paper focuses on the storage as the center of in- and outgoing thermal energy. The derived storage model has one spatial dimension which is justified by the high tube-to-particle diameter ratio and because yearly aggregated – and not momentary – values are of interest. A validation of the correlations with data from the literature shows acceptable agreement. Sensitivity analyses indicate that, due to low costs of the storage system, above certain minimum storage dimensions, the influence on energetic and monetary performance indicators is marginal. The calculated LCOE is in the range of 0.11–0.18 EUR/kW h and in agreement with other studies on combined cycle CSP plants.

Lukas Heller; Paul Gauché

2013-01-01T23:59:59.000Z

70

A mathematical model for countercurrent moving-bed activated carbon adsorption  

E-Print Network (OSTI)

the carbon column was divided into ten sections and the activated carbon flow rate was such that its detention time was fifty hours. Also, during this fifty hours one thousand gallons of water were treated. Thus the water volume of each section would... be one thou- sand gallons divided by ten sections or 100 gallons. One practical difficulty with the model is that an acti- vated carbon volume must be assumed, tests made, and calculations performed to determine if the effluent quality...

Anderson, Douglas Harold

1976-01-01T23:59:59.000Z

71

Impact of large scale circulation on European summer surface ozone and consequences for modelling forecast  

E-Print Network (OSTI)

of using day-to-day varying chemical boundary conditions produced by a global chemical weather forecast platform instead of climatological monthly means at the frontiers of a regional model. We performed two- transport models (CTMs) that represent physical and chemical processes controlling ozone concentrations

Menut, Laurent

72

Experimental and Modeling Study of Sulfur Capture by Limestone in Selected Conditions of Air-Fired and Oxy-fuel Circulating Fluidized-Bed Boilers  

Science Journals Connector (OSTI)

Liu et al.(5) noticed the influence of the system itself, noting that SO2 is enriched in the furnace of oxy-fuel combustion systems because the flue gas is recycled. ... This work has also been supported by the Academy of Finland under Grant 124368 and Foster Wheeler Energia Oy. ... In this study, the influence of CO2 on sulfur capture efficiency was studied during fluidized-bed desulfurization by experiments and modeling. ...

Sirpa Takkinen; Timo Hyppänen; Jaakko Saastamoinen; Toni Pikkarainen

2011-06-30T23:59:59.000Z

73

Cosmological and Solar System Consequences of f(R,T) Gravity Models  

E-Print Network (OSTI)

To find more deliberate f(R,T) cosmological solutions, we proceed our previous paper further by studying some new aspects of the considered models via investigation of some new cosmological parameters/quantities to attain the most acceptable cosmological results. Our investigations are performed by applying the dynamical system approach. We obtain the cosmological parameters/quantities in terms of some defined dimensionless parameters that are used in constructing the dynamical equations of motion. The investigated parameters/quantities are the evolution of the Hubble parameter and its inverse, the "weight function", the ratio of the matter density to the dark energy density and its time variation, the deceleration, the jerk and the snap parameters, and the equation-of-state parameter of the dark energy. We numerically examine these quantities for two general models $R+\\alpha R^{-n}+\\sqrt{-T}$ and $R\\log{[\\alpha R]}^{q}+\\sqrt{-T}$. All considered models have some inconsistent quantities (with respect to the available observational data), except the model with n=-0.9 which has more consistent quantities than the other ones. By considering the ratio of the matter density to the dark energy density, we find that the coincidence problem does~not refer to a unique cosmological event, rather, this coincidence also occurred in the early universe. We also present the cosmological solutions for an interesting model $R+c_{1}\\sqrt{-T}$ in the non--flat FLRW metric. We show that this model has an attractor solution for the late times, though with $w^{(\\textrm{DE})}=-1/2$. This model indicates that the spatial curvature density parameter gets negligible values until the present era, in which it acquires the values of the order $10^{-4}$ or $10^{-3}$. As the second part of this work, we consider the weak-field [It continues ...

Hamid Shabani; Mehrdad Farhoudi

2014-08-19T23:59:59.000Z

74

E-Print Network 3.0 - assessing bed net Sample Search Results  

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

for: assessing bed net Page: << < 1 2 3 4 5 > >> 1 Modeling decadal bed material sediment flux based on stochastic Michael Bliss Singer and Thomas Dunne Summary: ; published...

75

Dynamic Modeling and Control Studies of a Two-Stage Bubbling Fluidized Bed Adsorber-Reactor for Solid-Sorbent CO{sub 2} Capture  

SciTech Connect

A one-dimensional, non-isothermal, pressure-driven dynamic model has been developed for a two-stage bubbling fluidized bed (BFB) adsorber-reactor for solid-sorbent carbon dioxide (CO{sub 2}) capture using Aspen Custom Modeler® (ACM). The BFB model for the flow of gas through a continuous phase of downward moving solids considers three regions: emulsion, bubble, and cloud-wake. Both the upper and lower reactor stages are of overflow-type configuration, i.e., the solids leave from the top of each stage. In addition, dynamic models have been developed for the downcomer that transfers solids between the stages and the exit hopper that removes solids from the bottom of the bed. The models of all auxiliary equipment such as valves and gas distributor have been integrated with the main model of the two-stage adsorber reactor. Using the developed dynamic model, the transient responses of various process variables such as CO{sub 2} capture rate and flue gas outlet temperatures have been studied by simulating typical disturbances such as change in the temperature, flowrate, and composition of the incoming flue gas from pulverized coal-fired power plants. In control studies, the performance of a proportional-integral-derivative (PID) controller, feedback-augmented feedforward controller, and linear model predictive controller (LMPC) are evaluated for maintaining the overall CO{sub 2} capture rate at a desired level in the face of typical disturbances.

Modekurti, Srinivasarao; Bhattacharyya, Debangsu; Zitney, Stephen E.

2013-07-31T23:59:59.000Z

76

Compilation of Gas Intrusion Measurements, Variations, and Consequence Modeling for SPR Caverns  

SciTech Connect

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 H{sub 2}S 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

77

Calculation and modelling to the brown coal drying fluidized bed specialized for Greek lignite of west Macedonia  

Science Journals Connector (OSTI)

Brown coal is considered to be a competitive primary energy source for power generation in parts of Central and Eastern Europe due to the economically recoverable reserves of this fuel in these regions. Specifically for Greece lignites is the main fuel ... Keywords: brown coal, electric energy, energy source, fluidized bed, lignites

John Karmalis; Nikolaos Asimopoulos; Dimitrios Zissopoulos; Natsos Kouvatsis

2010-07-01T23:59:59.000Z

78

On Synthesis of the Big Bang Model with Freundlich's Redshift and its Cosmological Consequences  

E-Print Network (OSTI)

We derive exact theoretical value of the constant cosmic background radiation (CBR) temperature $T_0$ using the interconnections between the Gamow, Alpher and Herman (GAH) hot Big Bang cosmology model of the expanding Universe and the modified Freundlich redshift. As a result of this confluence an astonishing relationship between $T_0$ and the four fundamental physical constants $c$,$\\hbar$,$k$,$G$ is found including also the Melvin's value of the Freundlich constant $A_s$.Then the resulting predicted the CBR temperature is $T_0=2.76626 K$. This prediction show excellent agreement with the data obtained from ground-based and balloon-borne observations and also with a mean of the perfect black-body spectrum CMB temperature $2.725 K$ measured COBE in 1992. Using a new cosmological model we determine the horizon scale, age and mass of the present observable Universe. The calculations based on discrete redshift equations for the electromagnetic, electroweak phases and Planck epoch of the Universe predicts a graviton and string masses, which are originated beyond on Planck time. The predicted graviton mass $m_Gr$ is about five orders of magnitude less than the present "the best possible upper bounds on the mass of the graviton", which may be "discovered" in the proposed LISA observations. We present quantitative new results for the different quantum-cosmological parameters. Finally, it is showed that the mystery largeness and smallness dimensionless combination of the Quantum Cosmological constant $\\Lambda_0$ and Planck length $l_Pl$ may be derived as their ratio from the Trans-Planck redshift relation. Thus is found the meaning a famous largeness cosmological number $c^3/\\hbarG\\Lambda_0=2.8*10^{125}$ that is inverse of $\\Lambda_0 l_Pl^2=3.6*10^{-126}$, and "which in 1930s was a regarded as a major problem by Eddington and Dirac".

Asger G. Gasanalizade

2010-09-24T23:59:59.000Z

79

Bed material agglomeration during fluidized bed combustion  

SciTech Connect

The purpose of this project is to determine the physical and chemical reactions which led to the undesired agglomeration of bed material during fluidized bed combustion and to relate these reactions to specific causes. Survey of industrial-scale fluidized bed combustors is being conducted to determine the occurrence of bed agglomeration and the circumstances under which agglomeration took place. This task should be finished by the end of February. Samples of bed material, agglomerate material, and boiler deposits are being requested from boiler operators as part of the survey. Once received, these sample will be analyzed to determine chemical and mineralogic composition. The bulk chemical determination will be performed using x-ray fluorescence and inductively coupled plasma-optical emission (ICP). Mineralogy will be detected by x-ray diffraction (XRD). Chemical and mineral reactions will be determined by scanning electron microscopy, optical microscopy, and electron microprobe.

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

1993-02-01T23:59:59.000Z

80

Review of models used for determining consequences of UF{sub 6} release: Development of model evaluation criteria. Volume 1  

SciTech Connect

The objective of this study is to examine the usefulness and effectiveness of currently existing models that simulate the release of uranium hexafluoride from UF{sub 6}-handling facilities, subsequent reactions of UF{sub 6} with atmospheric moisture, and the dispersion of UF{sub 6} and reaction products in the atmosphere. The study evaluates screening-level and detailed public-domain models that were specifically developed for UF{sub 6} and models that were originally developed for the treatment of dense gases but are applicable to UF{sub 6} release, reaction, and dispersion. The model evaluation process is divided into three specific tasks: model-component evaluation; applicability evaluation; and user interface and quality assurance and quality control (QA/QC) evaluation. Within the model-component evaluation process, a model`s treatment of source term, thermodynamics, and atmospheric dispersion are considered and model predictions are compared with actual observations. Within the applicability evaluation process, a model`s applicability to Integrated Safety Analysis, Emergency Response Planning, and Post-Accident Analysis, and to site-specific considerations are assessed. Finally, within the user interface and QA/QC evaluation process, a model`s user-friendliness, presence and clarity of documentation, ease of use, etc. are assessed, along with its handling of QA/QC. This document presents the complete methodology used in the evaluation process.

Nair, S.K.; Chambers, D.B.; Park, S.H.; Hoffman, F.O. [Senes Oak Ridge, Inc., TN (United States). Center for Risk Analysis

1997-11-01T23:59:59.000Z

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.


81

Impacts of different SNLS3 light-curve fitters on cosmological consequences of interacting dark energy models  

E-Print Network (OSTI)

Aims: We explore the cosmological consequences of interacting dark energy (IDE) models using the Supernova Legacy Survey three-year (SNLS3) data sets. In particular, we focus on the impacts of different SNLS3 light-curve fitters (LCF) (corresponding to the "SALT2", the "SiFTO", and the "Combined" supernova sample). Methods: Firstly, making use of the three SNLS3 data sets, as well as the observational data from the cosmic microwave background (CMB), the galaxy clustering (GC) and the direct measurement of Hubble constant $H_0$, we constrain the parameter spaces of three IDE models. Then, we plot the cosmic evolutions of Hubble diagram $H(z)$, deceleration diagram $q(z)$ and statefinder hierarchy $\\{S^{(1)}_3, S^{(1)}_4\\}$, and check whether or not these dark energy (DE) diagnosis can distinguish the differences among the results of different LCF. At last, we perform high-redshift cosmic age test using three old high redshift objects (OHRO), and explore the fate of the Universe. Results: For all the IDE models...

Hu, Yazhou; Li, Nan; Wang, Shuang

2015-01-01T23:59:59.000Z

82

Review of models used for determining consequences of UF{sub 6} release: Model evaluation report. Volume 2  

SciTech Connect

Three uranium hexafluoride-(UF{sub 6}-) specific models--HGSYSTEM/UF{sub 6}, Science Application International Corporation, and RTM-96; three dense-gas models--DEGADIS, SLAB, and the Chlorine Institute methodology; and one toxic chemical model--AFTOX--are evaluated on their capabilities to simulate the chemical reactions, thermodynamics, and atmospheric dispersion of UF{sub 6} released from accidents at nuclear fuel-cycle facilities, to support Integrated Safety Analysis, Emergency Response Planning, and Post-Accident Analysis. These models are also evaluated for user-friendliness and for quality assurance and quality control features, to ensure the validity and credibility of the results. Model performance evaluations are conducted for the three UF{sub 6}-specific models, using field data on releases of UF{sub 6} and other heavy gases. Predictions from the HGSYSTEM/UF{sub 6} and SAIC models are within an order of magnitude of the field data, but the SAIC model overpredicts beyond an order of magnitude for a few UF{sub 6}-specific data points. The RTM-96 model provides overpredictions within a factor of 3 for all data points beyond 400 m from the source. For one data set, however, the RTM-96 model severely underpredicts the observations within 200 m of the source. Outputs of the models are most sensitive to the meteorological parameters at large distances from the source and to certain source-specific and meteorological parameters at distances close to the source. Specific recommendations are being made to improve the applicability and usefulness of the three models and to choose a specific model to support the intended analyses. Guidance is also provided on the choice of input parameters for initial dilution, building wake effects, and distance to completion of UF{sub 6} reaction with water.

Nair, S.K.; Chambers, D.B.; Park, S.H.; Radonjic, Z.R.; Coutts, P.T.; Lewis, C.J.; Hammonds, J.S.; Hoffman, F.O. [Senes Oak Ridge, Inc., TN (United States). Center for Risk Analysis

1997-11-01T23:59:59.000Z

83

Identification of data gaps found during the development of a zero-order model for a fluidized-bed retort/combustion process  

SciTech Connect

This technical note (TN) reports on the development of a zero-order ASPEN (Advanced System for Process Engineering) model for the fluidized-bed retort/combustion of an eastern oil shale. The objective of the work described was to identify data needs and to create a structure for future, more definitive models. New Albany shale was the initial reference eastern shale at the Department of Energy (DOE)/Morgantown Energy Technology Center (METC). A literature search on this shale was conducted to find the physical property data required for the ASPEN model. This TN discusses the types of missing or incomplete data, the process being modeled, and how process variables are affected by varying input parameters. The TN also presents recommendations for increasing the reliability of the simulation. 12 refs., 3 figs., 5 tabs.

Ammer, J.R.

1986-01-01T23:59:59.000Z

84

17 - Fluidized bed gasification  

Science Journals Connector (OSTI)

Abstract: The chapter describes the state-of-the-art of fluidized bed gasification of solid fuels, starting from the key role played by hydrodynamics, and its strong correlation with physical and chemical phenomena of the process and operating performance parameters of the reactor. The possible configurations of fluidized bed gasification plants are also assessed, and an analysis of the main methods for syngas cleaning is reported. Finally, the chapter describes some of the most interesting commercial experiences. The analysis indicates that the gasification of biomass and also of municipal and industrial solid wastes appear to be the most interesting sectors for the industrial development and utilization of fluidized bed gasifiers.

U. Arena

2013-01-01T23:59:59.000Z

85

Packed Bed Combustion: An Overview  

E-Print Network (OSTI)

;Packed Bed Combustion - University of Ottawa - CICS 2005 fuel fuel feed air products air fuel Retort) products Underfeed Combustion fuel feed air #12;Packed Bed Combustion - University of Ottawa - CICS 2005 required #12;Packed Bed Combustion - University of Ottawa - CICS 2005 Overfeed Bed fuel motion products air

Hallett, William L.H.

86

The influence of multiple tubes on the tube-to-bed heat transfer in a fluidised bed L.M. Armstrong, S. Gu  

E-Print Network (OSTI)

for flow prediction in the past without heat transfer modelling. In the present study, a two-fluid EulerianThe influence of multiple tubes on the tube-to-bed heat transfer in a fluidised bed L.M. Armstrong Keywords: CFD Heat transfer Fluidised bed Eulerian a b s t r a c t There have been few studies modelling

87

Erosion of heat exchanger tubes in fluidized beds  

SciTech Connect

This final report describes the activities of the 3-year project entitled Erosion of Heat Exchanger Tubes In Fluidized Beds.'' which was completed at the end of 1990. Project accomplishments include the collection of a substantial body of wear data In a 24in. [times] 24in. fluidized bed, comparative wear results In a 6in. [times] 6in. fluidized bed, the development of a dragometer and the collection of a comprehensive set of drag force data in the 24in. [times] 24in. bed, Fast Fourier Transform (FFT) analysis of bubble probe data to establish dominant bubble frequencies in the 24in. [times] 24in. bed, the use of a heat flux gauge for measurement of heat transfer coefficients in the 24in. [times] 24in. bed and the modeling of the tube wear in the 24in. [times] 24in. bed. Analysis of the wear data from the 24in. square bed indicates that tube wear increases with increase in superficial velocity, and with increase in tube height. The latter effect is a result of the tubes higher up in the bed seeing greater movement of dense phase than tubes lower down In the bed. In addition, tube wear was found to decrease with increase in particle size, for constant superficial velocity. Three models of tube wear were formulated and provided acceptable prediction of wear when compared with the experimental data.

Johnson, E.K.; Flemmer, R.L.C.

1991-01-01T23:59:59.000Z

88

Adsorption of model textile dyes from aqueous solutions using agricultural wastes as adsorbents: equilibrium, kinetics and fixed bed column study  

Science Journals Connector (OSTI)

Gram husk and groundnut shell are cheap and abundantly available agricultural waste materials in India. A systematic study on the adsorption of some model dyes from aqueous solution on these low-cost adsorbents has been attempted. Model dyes used were Methylene Blue, Rhodamine B, Congo Red, Eosine Y and Metanil Yellow. Equilibrium, kinetics and column experiments were performed. Effects of different process variables have been studied. Equilibrium data fitted well in Langmuir and Freundlich isotherm equations. A model using Freundlich equation has been developed for interpretation of kinetic data. Other models such as Lagergren equation and pseudo second order equation were also used. Of these models, pseudo second order equation was found to be the most satisfactory. Column experiments were carried out with gram-husk and Rhodamine B. The data could be correlated well with BDST model.

Sampa Chakrabarti; Basab Chaudhuri; Binay K. Dutta

2008-01-01T23:59:59.000Z

89

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

90

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...

91

Tenth annual fluidized bed conference  

SciTech Connect

The proceedings of the Tenth Annual Fluidized Bed Conference is presented. The Conference was held November 14-15, 1994 in Jacksonville, FL and covered such topics as: opportunity fuels, the fluid bed market, bubbling fluid bed retrofitting, waste fuel-based circulating fluidized-bed project, construction permits for major air pollution sources, fluidized bed residues, uses for fluidized bed combustion ash, ash pelletization, sorbents for FBC applications, refractory maintenance, and petroleum coke. A separate abstract and indexing have been prepared for each paper for inclusion in the Energy Science and Technology Database.

NONE

1994-12-31T23:59:59.000Z

92

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

93

Thermochemical process for seasonal storage of solar energy: characterization and modeling of a high-density reactive bed  

E-Print Network (OSTI)

1 Thermochemical process for seasonal storage of solar energy: characterization and modeling to maximize the use of solar energy for house heating, it is interesting to valorize the solar energy excess efficiency, and a 20 per cent share of renewable). The use of renewable energies and in particular solar

Paris-Sud XI, Université de

94

Effect of Char Combustion Product Distribution Coefficient on the CFD Modeling of Biomass Gasification in a Circulating Fluidized Bed  

Science Journals Connector (OSTI)

The predicted temperature profile can be used to select the refractory linings or bricks of the gasifier, and the predicted gas composition distribution may help to determine the size and shape of the gasifier. ... The enthalpy source from thermal radiation is computed by the P-1 model:(20, 26)(13)(14)where a, ?s, C, and n are the absorption coefficient, the scattering coefficient, the linear-anisotropic phase function coefficient, and the refractive index of the medium, respectively. ... A 3D unsteady-state CFD model is built in ANSYS Fluent 14.0, and the simulation results will be compared and validated with experimental data by García-Ibañez, et al.(18) Figure 1 shows the schematic diagram of the gasifier for the current studies, which sizes are the same as those of the gasifier used in the experiment. ...

Hui Liu; Ali Elkamel; Ali Lohi; Mazda Biglari

2014-03-12T23:59:59.000Z

95

Trickle - Bed reactor simulation using a process simulator  

Science Journals Connector (OSTI)

The present study deals with a multiple reaction system in both gas and liquid phases considering the effect of gas-liquid mass transfer limitations in a trickle-bed reactor where the catalytic hydrotreating of gas oil reaction is being carried out. ... Keywords: Trickle - bed reactor, hydrogenation, reactor model, user-added unit operation

E. Verruschi; J. Freitez; Y. Gonzalez; C. G. Dassori

2009-12-01T23:59:59.000Z

96

Fluidized Bed Fuel Cell Electrodes  

Science Journals Connector (OSTI)

... smoothed the electrolyte flow through the bed. The mesh acted as bed support and electrical contactor to the beads. In the case of the hydrogen peroxide electrode the nickel mesh ... at the top 'of the bed for the hydrogen peroxide electrode and close to the contactor for the methanol electrode. In both cases polarization measurements were carried out at 20 ...

T. BERENT; I. FELLS; R. MASON

1969-09-06T23:59:59.000Z

97

Modeling of fluidized-bed combustion of coal: Phase II, final reports. Volume VI. FBC-Data Base-Management-System (FBC-DBMS) development  

SciTech Connect

The primary goal of the Fluidized Bed Combustor Data Base, (FBCDB), situated in MIT's Energy laboratory, is to establish a data repository for the express use of designers and research personnel involved in FBC development. DBMS is a software that provides an efficient way of storing, retrieving, updating and manipulating data using an English-like query language. It is anticipated that the FBCDB would play an active and a direct role in the development of FBC technology as well as in the FBC commercial application. After some in-house experience and after a careful and extensive review of commercially available database systems, it was determined that the Model 204 DBMS by Computer Corporation of America was the most suitable to our needs. The setup of a prototype in-house database also allowed us to investigate and understand fully the particular problems involved in coordinating FBC development with a DBMS. Various difficult aspects were encountered and solutions had been sought. For instance, we found that it was necessary to rename the variables to avoid repetition as well as to increase usefulness of our database and, hence, we had designed a classification system for which variables were classified under category to achieve standardization of variable names. The primary content of FBCDB is a collection of data points defined by the value of a number of specific FBC variables. A user may interactively access the database from a computer terminal at any location, retrieve, examine, and manipulate the data as well as produce tables or graphs of the results.

Louis, J.F.; Tung, S.E.

1980-10-01T23:59:59.000Z

98

Modeling of fluidized-bed combustion of coal: Phase II, final reports. Volume VII. FBC Data-Base-Management System (FBC-DBMS) users manual  

SciTech Connect

The primary goal of the Fluidized Bed Combustor Data Base (FBCDB) is to establish a data repository for the express use of designers and research personnel involved in FBC development. FBCDB is implemented on MIT's 370/168 computer, using the Model 204 Data Base Management System (DBMS) developed by Computer Corporation of America. DBMS is a software that provides an efficient way of storing, retrieving, updating and manipulating data using an English-like query language. The primary content of FBCDB is a collection of data points defined by the value of a number of specific FBC variables. A user may interactively access the data base from a computer terminal at any location, retrieve, examine, and manipulate the data as well as produce tables or graphs of the results. More than 20 program segments are currently available in M204 User Language to simplify the user interface for the FBC design or research personnel. However, there are still many complex and advanced retrieving as well as applications programs to be written for this purpose. Although there are currently 71 entries, and about 2000 groups reposited in the system, this size of data is only an intermediate portion of our selection. The usefulness of the system at the present time is, therefore, limited. This version of FBCDB will be released on a limited scale to obtain review and comments. The document is intended as a reference guide to the use of FBCDB. It has been structured to introduce the user to the basics of FBCDB, summarize what the available segments in FBCDB can do, and give detailed information on the operation of FBCDB. This document represents a preliminary draft of a Users Manual. The draft will be updated when the data base system becomes fully implemented. Any suggestions as to how this manual may be improved will be appreciated.

Louis, J.F.; Tung, S.E.

1980-10-01T23:59:59.000Z

99

Modelling of Particle Pyrolysis in a Packed Bed Combustor A.R.C. Tuck and W.L.H. Hallett ,1 2*  

E-Print Network (OSTI)

Introduction Biomass combustion for renewable energy production has attracted increasing attention recently. Packed bed combustion is the most common mode of biomass combustion because of its tolerance of a wide range of fuel properties and particle sizes. As with most solid fuels, combustion occurs in three

Hallett, William L.H.

100

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

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

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

102

Fluidized bed boiler feed system  

DOE Patents (OSTI)

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

103

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. 3 figs.

Scott, C.D.; Marasco, J.A.

1995-04-25T23:59:59.000Z

104

Biparticle fluidized bed reactor  

DOE Patents (OSTI)

A fluidized bed reactor system is described 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. 3 figs.

Scott, C.D.; Marasco, J.A.

1996-02-27T23:59:59.000Z

105

Consequences and Truth  

Science Journals Connector (OSTI)

... Earth is probably not expanding. If this concept of moving plates is accepted then many consequences follow, and it is these that many Earth scientists are engaged in examining at ... many Earth scientists are engaged in examining at the moment, although, of course, the consequences do not necessarily mean that the hypothesis is the ...

A. C. D.

1972-12-08T23:59:59.000Z

106

Aspen Plus simulations of fluidised beds for chemical looping combustion  

Science Journals Connector (OSTI)

Abstract Chemical Looping Combustion (CLC) is a technology able to generate energy whilst managing CO2 emissions. A system composed by two interconnected fluidised beds is often used in CLC: the two fluidised beds are employed for carrying out the oxidation and reduction reactions of the metal oxide employed as oxygen carrier. In this work, a model to implement fluidised bed systems in Aspen Plus is presented. Depending on the hydrodynamic regimes, two different models are considered: one of the two fluidised beds, called the fuel reactor, is modelled according to the two-phase theory (i.e. emulsion and bubble phase) whilst the other bed, called the air reactor, is assumed to operate in the fast fluidisation regime. Kinetic equations for heterogeneous gas/solid reactions are also considered in the model. Simulation tests for each fluidised bed are carried out, and comparisons are made with experimental data from the literature. A comparison with the largely used Gibbs reactor model is carried out showing the advantages of using the models developed here. In addition, the net heat duty of the whole process is calculated and the role of the main variables that affect the process is investigated.

Rosario Porrazzo; Graeme White; Raffaella Ocone

2014-01-01T23:59:59.000Z

107

Determining average bed temperature of nonisothermal fixed-bed hydrotreater  

Science Journals Connector (OSTI)

Employing three catalysts in three parallel pilot-scale fixed-bed reactors, hydrotreating experiments were performed in both isothermal and ascending temperature modes to investigate kinetics and to determine a representative bed temperature. Assuming 1.5th-order for hydrodesulfurization (HDS) and 1st-order for both hydrodenitrogenation (HDN) and mild hydrocracking (MHC), kinetic parameters were obtained from the isothermal mode operation. With the activation energies from isothermal operations, equivalent isothermal temperatures (EITs) in the ascending mode operations were established for specific HDS, HDN and MHC. Employing 19 thermocouple readouts in the catalyst beds and applying an Arrhenius-type rate equation containing the same activation energy, the representative bed temperature was determined. The temperature so determined is called kinetic EIT. The kinetic EIT was found to be the best to represent the nonisothermal bed temperature. The kinetic EIT has been applied to monitoring the catalyst activity in commercial hydrotreating units.

Sok Yui; John Adjaye

2004-01-01T23:59:59.000Z

108

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

SciTech Connect

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

109

Use of post-Chernobyl data from Norway to validate the long-term exposure pathway models in the accident consequence code MACCS  

SciTech Connect

This paper describes a task performed for the US Nuclear Regulatory Commission (NRC), consisting of using post-Chernobyl data from Norway to verify or find areas for possible improvement in the chronic exposure pathway models utilized in the NRC's program for probabilistic risk analysis, level 3, of the MELCOR accident consequence code system (MACCS), developed at Sandia National Laboratories, Albuquerque, New Mexico. Because of unfortunate combinations of weather conditions, the levels of Chernobyl fallout in parts of Norway were quite high, with large areas contaminated to more than 100 kBq/m[sup 2] of radioactive cesium. Approximately 6% of the total amount of radioactive cesium released from Chernobyl is deposited on Norwegian territory, according to a countrywide survey performed by the Norwegian National Institute for Radiation Hygiene. Accordingly, a very large monitoring effort was carried out in Norway, and some of the results of this effort have provided important new insights into the ways in which radioactive cesium behaves in the environment. In addition to collection and evaluation of post-Chernobyl monitoring results, some experiments were also performed as part of the task. Some experiments performed pre-Chernobyl were also relevant, and some conclusions could be drawn from these. In most connections, the data available show the models and data in MACCS to be appropriate. A few areas where the data indicate that the MACCS approach is inadequate are, however, also pointed out in the paper.

Tveten, U. (Inst. for Energiteknikk, Kjeller (Norway))

1994-03-01T23:59:59.000Z

110

Pulsed atmospheric fluidized bed combustion  

SciTech Connect

The general specifications for a Pulsed Atmospheric Fluidized Bed Combustor Design Report (PAFBC) plant are presented. The design tasks for the PAFBC are described in the following areas: Coal/Limestone preparation and feed system; pulse combustor; fluidized bed; boiler parts; and ash handling system.

Not Available

1992-08-01T23:59:59.000Z

111

A new bed elevation dataset for Greenland  

E-Print Network (OSTI)

A new bed elevation dataset for Greenland J. L. Bamber 1 ,al. : A new bed elevation dataset for Greenland Howat, I. M.al. : A new bed elevation dataset for Greenland Fig. 3. (a)

2013-01-01T23:59:59.000Z

112

E-Print Network 3.0 - advanced fluidized bed Sample Search Results  

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

"Biomass Thermochemcial Conversion to Biofuels: Advances in Modeling and Summary: gasification in fluidized bed reactors will be presented. This includes the development of...

113

E-Print Network 3.0 - achieve high bed Sample Search Results  

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

validation of our reacting bed modelling code (FLIC) has... predictions. Our new gasification concept offers the prospect of ... Source: Columbia University - Waste-to-Energy...

114

IGNITION PROCESSES AND FLAME SPREADING IN A GRANULAR SOLID PROPELLANT BED.  

E-Print Network (OSTI)

??Understanding the detailed ignition, flame spreading, and combustion processes inside of a granular solid propellant bed is vital for accurate internal ballistic modeling and development… (more)

Colletti, Alexander

2010-01-01T23:59:59.000Z

115

Moving granular-bed filter development program. Topical report  

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, 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

116

Simulation of a High Efficiency Multi-bed Adsorption Heat Pump  

SciTech Connect

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

117

Morphological changes in the tongue as a consequence of manganese inhalation in a murine experimental model: Light and scanning electron microscopic analysis  

Science Journals Connector (OSTI)

......UNAM, Mexico Air pollution by suspended particles...these particles are fossils and additives combustion...Introduction Air pollution, as a consequence...is combustion of fuel sources and additives...followed by a fixative solution containing 2......

Teresa Imelda Fortoul; Madeleine Vélez-Cruz; Silvia Antuna-Bizarro; Luis F. Montaño; Vianey Rodriguez-Lara; Liliana Saldivar-Osorio

2010-02-01T23:59:59.000Z

118

Truth and consequences  

Science Journals Connector (OSTI)

... objective and scientifically based evidence, by the fact that polygraph examiners rarely know the real truth about the subject's guilt or innocence and, when a deceptive outcome is confirmed ... those who agree to take the test without realizing its limitations and the potential personal consequences. Failing a polygraph test, Lykken cogently argues, often gives employers an excuse to ...

Gisli H. Gudjonsson

1998-07-02T23:59:59.000Z

119

Moisture Transport in Silica Gel Packed Beds: II. Experimental Study  

SciTech Connect

Experiments have been performed to obtain the transient response of a thin adiabatic packed bed of silica gel after a step change in inlet air conditions, comparisons are made with predictions using a solid-side resistance model and a pseudo-gas-side controlled model and better agreement obtained with the former model.

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

1986-08-01T23:59:59.000Z

120

Twelfth annual fluidized bed conference  

SciTech Connect

The Proceedings of the Twelfth Annual Fluidized Bed Conference held November 11-13, 1996 in Pittsburgh, PA are presented. Information is given on: owner`s discussions; new aspects and field upgrades in fluidized bed boilers; manufacturer`s perspectives; fuel considerations; FBC ash reclassification; and beneficial uses of FBC ash. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

NONE

1996-12-31T23:59:59.000Z

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.


121

Stream-bed scour, egg burial depths, and the influence of salmonid spawning on bed surface  

E-Print Network (OSTI)

Stream-bed scour, egg burial depths, and the influence of salmonid spawning on bed surface mobility-Hames, and Thomas P. Quinn Abstract: Bed scour, egg pocket depths, and alteration of stream-bed surfaces by spawning chum salmon (Onchorhynchus keta) were measured in two Pacific Northwest gravel-bedded streams. Close

Montgomery, David R.

122

Three-dimensional CFD simulation of hydrodynamics in an interconnected fluidized bed for chemical looping combustion  

Science Journals Connector (OSTI)

Abstract A hydrodynamic model of an interconnected fluidized bed for chemical looping combustion was established based on the Eulerian–Eulerian two-fluid model with the kinetic theory of granular flow. The effect of the drag model on the computational results was investigated and detailed hydrodynamics were predicted in the three-dimensional circulating fluidized bed (composed of a riser, bubbling bed, pot-seal and cyclone). Both qualitative and quantitative results indicated that the drag model had a significant effect on the flow behavior. The Gidaspow and the Syamlal & O'Brien drag models both produced accurate predictions in this study. The pressure balance of an interconnected fluidized bed revealed that the pressure in the bubbling bed was lower than that in the pot-seal and the riser, whilst still being higher than the pressure in the cyclone. The riser and bubbling bed were individually operated in fast and bubbling fluidization regions. The three distinct regions identified from the bottom to the top of the riser were: entrance region, bulk region and exit region. The solids volume fraction was higher in the near-wall region but lower in the center region for both the riser and bubbling bed. The coupled characteristics of the fluidized bed were predominantly identified by the strong effect of operational gas velocity in the riser on the hydrodynamics in the bubbling bed.

Yanjun Guan; Jian Chang; Kai Zhang; Baodong Wang; Qi Sun

2014-01-01T23:59:59.000Z

123

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

124

Simulation of petcoke gasification in slagging moving bed reactors  

Science Journals Connector (OSTI)

A mathematical model for simulation of moving bed petcoke gasifiers was developed. The model introduces a new feed characterization method, gas-phase resistance and volatilization models. The model is validated using reported data for a slagging gasifier. Effect of feed oxygen-to-coke and steam-to-coke ratios and feed coke rates on gasification performance was examined. Slagging zone moving bed gasifier operation with very high petcoke fluxes of over 4000 kg/m2/h was possible with high petcoke conversion. Peak gas temperatures exceeded 1500 °C. Fluxes higher than 5000 kg/m2/h are limited by an approach to fluidization of small particles in the combustion zone. The moving bed gasifier performance was found superior to performance of an entrained flow gasifier (EFG) with respect to energy efficiency and oxygen consumption.

Soumitro Nagpal; T.K. Sarkar; P.K. Sen

2005-01-01T23:59:59.000Z

125

Erosion of heat exchanger tubes in fluidized beds. Annual report, 1990  

SciTech Connect

This final report describes the activities of the 3-year project entitled ``Erosion of Heat Exchanger Tubes In Fluidized Beds.`` which was completed at the end of 1990. Project accomplishments include the collection of a substantial body of wear data In a 24in. {times} 24in. fluidized bed, comparative wear results In a 6in. {times} 6in. fluidized bed, the development of a dragometer and the collection of a comprehensive set of drag force data in the 24in. {times} 24in. bed, Fast Fourier Transform (FFT) analysis of bubble probe data to establish dominant bubble frequencies in the 24in. {times} 24in. bed, the use of a heat flux gauge for measurement of heat transfer coefficients in the 24in. {times} 24in. bed and the modeling of the tube wear in the 24in. {times} 24in. bed. Analysis of the wear data from the 24in. square bed indicates that tube wear increases with increase in superficial velocity, and with increase in tube height. The latter effect is a result of the tubes higher up in the bed seeing greater movement of dense phase than tubes lower down In the bed. In addition, tube wear was found to decrease with increase in particle size, for constant superficial velocity. Three models of tube wear were formulated and provided acceptable prediction of wear when compared with the experimental data.

Johnson, E.K.; Flemmer, R.L.C.

1991-01-01T23:59:59.000Z

126

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

127

Methanol synthesis in a trickle bed reactor  

E-Print Network (OSTI)

kinetic models for methanol synthesis under the assumption that the rate limiting step was the reaction between an adsorbed CO molecule and two adsorbed H2 molecules. The experiment was conducted over a Cu/ZnO/Cr~03 catalyst in a fixed bed reactor... to account for the large degree of initial deactivation. However, Rozovskii (1980) claimed the opposite and stated that methanol is made from carbon dioxide and no methanol is produced from Hz/CO mixtures over the Cu/ZnO/Alz03 catalyst. Liu et al. (1984...

Tjandra, Sinoto

1992-01-01T23:59:59.000Z

128

Neutronic analysis of pebble-bed cores with transuranics  

E-Print Network (OSTI)

(ORNL). This Department of Energy sponsored center is authorized to collect, maintain, analyze, and distribute computer software and data sets in the area of radiation transport and safety. The full-core VHTR pebble-bed model was developed... II.A SCALE 5.0 The 3D full-core pebble-bed VHTR model was initially built using SCALE version 5.0. The modular code system is developed and maintained by ORNL and is readily validated and accepted for use in thermal reactor analysis around...

Pritchard, Megan Leigh

2009-05-15T23:59:59.000Z

129

Advanced atmospheric fluidized-bed combustion design - spouted bed  

SciTech Connect

This report describes the Spouted-Fluidized Bed Boiler that is an advanced atmospheric fluidized bed combustor (FBC). The objective of this system design study is to develop an advanced AFBC with improved performance and reduced capital and operating costs compared to a conventional AFBC and an oil-fired system. The Spouted-Fluidized Bed (SFB) system is a special type of FBC with a distinctive jet of air in the bed to establish an identifiable solids circulation pattern. This feature is expected to provide: reduced NO/sub x/ emissions because of the fuel rich spout zone; high calcium utilization, calcium-to-sulfur ratio of 1.5, because of the spout attrition and mixing; high fuel utilization because of the solids circulation and spout attrition; improved thermal efficiency because of reduced solids heat loss; and improved fuel flexibility because of the spout phenomena. The SFB was compared to a conventional AFBC and an oil-fired package boiler for 15,000 pound per hour system. The evaluation showed that the operating cost advantages of the SFB resulted from savings in fuel, limestone, and waste disposal. The relative levelized cost for steam from the three systems in constant 1985 dollars is: SFB - $10 per thousand pounds; AFBC - $11 per thousand pounds; oil-fired - $14 per thousand pounds. 18 refs., 5 figs., 11 tabs.

Shirley, F.W.; Litt, R.D.

1985-11-27T23:59:59.000Z

130

Sorption of anionic surfactants on a fixed bed of rubber granules  

Science Journals Connector (OSTI)

The performance of a fixed-bed adsorber (FBR) column for the removal of anionic surfactants from aquatic environments has been studied. Waste tyre rubber granules were used as the adsorbent material, and sodium dodecyl sulfate, an anionic surfactant, as the adsorbate. The FBR column design parameters were evaluated using the column breakthrough data at different bed depths. The Bohert and Adams model was used with the bed depth service time approach for the design of the column. The bed efficiency obtained was 90.97%.

Paritosh Das Purakayastha; Anjali Pal; Manas Bandyopadhyay

2003-01-01T23:59:59.000Z

131

Bed material agglomeration during fluidized bed combustion. Final report  

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 of coal and to relate these reactions to specific causes. A survey of agglomeration and deposit formation in industrial fluidized bed combustors (FBCs) indicate that at least five boilers were experiencing some form of bed material agglomeration. Deposit formation was reported at nine sites with deposits most commonly at coal feed locations and in cyclones. Other deposit locations included side walls and return loops. Three general types of mineralogic reactions were observed to occur in the agglomerates and deposits. Although alkalies may play a role with some {open_quotes}high alkali{close_quotes} lignites, we found agglomeration was initiated due to fluxing reactions between iron (II) from pyrites and aluminosilicates from clays. This is indicated by the high amounts of iron, silica, and alumina in the agglomerates and the mineralogy of the agglomerates. Agglomeration likely originated in the dense phase of the FBC bed within the volatile plume which forms when coal is introduced to the boiler. Secondary mineral reactions appear to occur after the agglomerates have formed and tend to strengthen the agglomerates. When calcium is present in high amounts, most of the minerals in the resulting deposits are in the melilite group (gehlenite, melilite, and akermanite) and pyroxene group (diopside and augite). During these solid-phase reactions, the temperature of formation of the melilite minerals can be lowered by a reduction of the partial pressure of CO{sub 2} (Diopside + Calcite {r_arrow}Akermanite).

Brown, R.C.; Dawson, M.R.; Smeenk, J.L.

1996-01-01T23:59:59.000Z

132

Bed management in a Critical Care Unit  

Science Journals Connector (OSTI)

......can also be approach using a stochastic...150 BED MANAGEMENT IN A CRITICAL...of Decision Sciences and Information Management, Catholic University...bed-occupancy management and planning...Improving the Sipp approach for staffing......

J. D. Griffiths; V. Knight; I. Komenda

2013-04-01T23:59:59.000Z

133

Eleventh annual fluidized bed conference  

SciTech Connect

The Proceedings of the Eleventh Annual Fluidized Bed Conference are presented. The Conference was held November 14-15, 1995 in Allentown, Pennsylvania and discussed the following topics: third and fourth generation systems; fuel considerations; and FBC energy and environmntal regulatory issues. A separate abstract was entered into the Energy Science and Technology Database for each of the 19 papers presented at the conference.

NONE

1995-12-31T23:59:59.000Z

134

Non-convex flux functions and compound shock waves in sediment beds  

E-Print Network (OSTI)

Non-convex flux functions and compound shock waves in sediment beds Gert Bartholomeeusen1 , Hans De of Engineering Science, Parks Road, Oxford OX1 3PJ, UK gilliane.sills@eng.ox.ac.uk Summary. Sediment layers in sediment beds and the numerical modelling of the sedimentation process using an experimentally obtained

De Sterck, Hans

135

Optimal control of a time-varying catalytic fixed bed reactor with catalyst deactivation  

Science Journals Connector (OSTI)

The paper deals with the linear-quadratic control problem for a time-varying partial differential equation model of a catalytic fixed-bed reactor. The classical Riccati equation approach, for time-varying infinite-dimensional systems, is extended to ... Keywords: catalyst deactivation, fixed bed reactor, infinite dimensional time-varying system, linear quadratic optimal control

L. Mohammadi; I. Aksikas; J. F. Forbes

2009-06-01T23:59:59.000Z

136

CIRCULATING MOVING BED COMBUSTION PROOF OF CONCEPT  

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: • 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

137

Fluidization quality analyzer for fluidized beds  

DOE Patents (OSTI)

A control loop and fluidization quality analyzer for a fluidized bed utilizes time varying pressure drop measurements. A fast-response pressure transducer measures the overall bed pressure drop, or over some segment of the bed, and the pressure drop signal is processed to produce an output voltage which changes with the degree of fluidization turbulence. 9 figs.

Daw, C.S.; Hawk, J.A.

1995-07-25T23:59:59.000Z

138

Entrainment Coal Gasification Modeling  

Science Journals Connector (OSTI)

Entrainment Coal Gasification Modeling ... Equivalent Reactor Network Model for Simulating the Air Gasification of Polyethylene in a Conical Spouted Bed Gasifier ... Equivalent Reactor Network Model for Simulating the Air Gasification of Polyethylene in a Conical Spouted Bed Gasifier ...

C. Y. Wen; T. Z. Chaung

1979-10-01T23:59:59.000Z

139

V Truth and Consequence  

Science Journals Connector (OSTI)

Publisher Summary This chapter focuses on truth and its consequences. The terms “true” and “false” occur constantly in mediaeval logical works. For the most part this was merely because of the fact that mediaeval logic was formulated as a system of rules of inference and not as a calculus of uninterpreted formulas developed in logistic manner through rules of operation on the symbols. But because the normal interpretation of a logical calculus is such that a formula and its negation represent contradictory propositions of which one is true and the other false, this usage of the terms “true” and “false” had no metaphysical implications but was simply a convenient means of describing logical relations among sentences. The problem of defining the term “true,” as a term connoting the relation between a sentence and things or events outside of language, is a metaphysical or philosophical problem. It was discussed primarily in works dealing with metaphysics, and in connection with the definitions of truth found in Aristotle's Metaphysics.

1953-01-01T23:59:59.000Z

140

Uniform retorting of an anisotropic shale bed  

SciTech Connect

In situ oil shale retorts have typically been designed for the fracturing event to produce a rubble bed having uniform cross-sectional rubble properties. This uniform rubble bed approach strived to produce constant void fraction and particle size distribution within all regions of the rubble bed. Ideally, these isotropic rubble beds have uniform flow of oxidants, retorting and combustion products. However, edge effects during the blast event typically produce channeling at the retort walls during processing, reducing the rubble sweep and the local yield. Second generation in situ retorts are addressing uniform retorting within the rubble bed rather than the uniformity of rubble bed properties. Here, the blast design produces and anisotropic rubble bed with varying particle size distribution and void fraction normal to the direction of flow. This paper describes a laboratory experiment in which a highly-instrumented, 100 kg bed of shale with zones of differing particle size and void was retorted. Shale particle size and void were varied over the retort cross-section so that a retorting front would move at a constant velocity downward through the rubble bed. The bed was designed using data from numerous pressure drop measurements on uniform shale beds of varying shale particle size distribution and void. Retorting of the bed showed a uniform retorting front and a yield comparable with that achieved in isotropic shale beds. We present thermal data and offgas, oil and shale analyses (allowing material and energy balance closures) and compare these data to previous vertical retorting experiments on uniform and non-uniform beds of shale. This experiment verifies that uniform retorting fronts can be achieved in correctly designed anisotropic beds of shale and validates the concept of uniform retorting in order increase the oil recovery in second generation retorts. 20 refs., 17 figs., 4 tabs.

Bickel, T.C.; Cook, D.W.; Engler, B.P.

1986-01-01T23:59:59.000Z

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.


141

Factorial tests on process operating conditions and bed fines on the circulating fluid bed performance  

SciTech Connect

A cold-flow circulating fluid bed (CFB) was operated using coke breeze with a packed-bed standpipe over a range of riser and standpipe air flows. The bed materials were selected to simulate solids flow in a CFB gasifier (carbonizer) but are generally relevant to most CFB processes. CFB tests were conducted primarily in the transport mode with sufficient gas velocity to achieve a uniform axial riser pressure profiles over most of the riser height. The independent variables tested included the riser gas velocity, aeration at the base of the standpipe, and concentration of fines (average particle size). The solids inventory and riser outlet pressure were maintained constant. Factorial tests were conducted in randomized order and in duplicate to provide and an unbiased estimate of the error. Fines were tested as a blocked variable. The gas velocity, standpipe aeration, and relative amount of fine particles were all found to be significant factors affecting both the riser solids holdup and solids flux. The riser pressure drop and mass circulation increased at the higher level of fines contrary to some earlier reports in the literature. The riser pressure drop was fitted using the general linear model (GLM), which explained more than 98% of the variation within the data, while a GLM for the mass circulation rate explained over 90%. The uncertainty of process operating variables was characterized independently through a series of duplicated flow proving experiments.

Shadle, L.J.; Spenik, James; Sarra, Angela; Ontko, J.S.

2004-07-21T23:59:59.000Z

142

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.

143

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

144

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

145

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

146

Building a Raised Bed Garden  

E-Print Network (OSTI)

need, and are less likely to wet foliage. However, they do have some disadvantages. Emitters are prone to clogging unless the water used is very clean, and if emitters are installed under mulch it is difficult to spot problems. Emitters are also... this flexibility as your plantings mature. If you choose drip or trickle irrigation, determine the length of the hose and the number of emitters you will need. Drip tape with 12-inch emitter spacing is best for vegetables. Beds should be divided into watering zones...

Files, Priscilla J.; Dainello, Frank J.; Arnold, Michael A.; Welsh, Douglas F.

2009-03-26T23:59:59.000Z

147

Circulating fluidised-bed combustion  

SciTech Connect

Steam generators with circulating fluidized-bed combustion systems (CFBC) are characterized by a high degree of environmental comparability and a wide acceptance for FBC boiler plants involving a wide fuel spectrum which ranges from dried brown coal to high-ash coal and low-volatile bituminous coal as well as wood waste and bark. These plants incorporate a variety of CFBC systems. The choice in favor of different system options was not motivated by the inherent fuel properties but has evolved from the progressive advancement in power station FBC technology. The article elucidates several FBC system variants.

Rettemeier, W.; von der Kammer, G. (Steinmueller (L.u.C.) GmbH, Gummersbach (Germany, F.R.))

1990-01-01T23:59:59.000Z

148

Experimental and modeling results for reconsolidation of crushed natural rock salt under varying physical conditions: Applications to nuclear waste isolation in bedded and domal salt formations  

SciTech Connect

Mined salt from the underground facility at the Waste Isolation Pilot Plant (WIPP) Project is a candidate material for use as backfill around the waste packages and in the underground openings during and after the operational phase. We have conducted a series of hydrostatic and triaxial compression experiments on the time-dependent compaction behavior of crushed salt under nominally dry, damp,'' (0.5-5 wt % added water), and brine-saturated conditions. Though the compaction of dry crushed salt is very slow in the laboratory, damp salt is likely to compact as rapidly as the mine walls can converge. Drained tests on brine-saturated crushed salt indicate that, though effects associated with saturation do retard consolidation rates slightly, high fractional densities ({ge}0.95) can still be obtained on laboratory times scales at pressures below lithostatic at the WIPP. Triaxial compression experiments indicate that small deviatoric stresses have little impact on consolidation rates. Micromechanical models for the compaction of dry and damp crushed salt, based on isostatic hot-pressing models, are discussed. 14 refs., 4 figs.

Zeuch, D.H.; Holcomb, D.J.

1991-01-01T23:59:59.000Z

149

Fluidized Bed Technology - Overview | Department of Energy  

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

Fluidized-bed combustion evolved from efforts to find a combustion process able to control pollutant emissions without external emission controls (such as scrubbers). The...

150

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

151

Particle Receiver Integrated with Fludized Bed  

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

Bed CONTACTS Partnering Organizations: * Babcock & Wilcox Power Generation Group, Inc. * Massachusetts Institute of Technology For more information, visit the project page at:...

152

Granular Dynamics in Pebble Bed Reactor Cores  

E-Print Network (OSTI)

pebble bed reactor,” Nuclear Engineering and Design, vol.the AVR reactor,” Nuclear Engineering and Design, vol. 121,Operating Experience,” Nuclear Engineering and Design, vol.

Laufer, Michael Robert

2013-01-01T23:59:59.000Z

153

Cosmological Consequences of String Axions  

SciTech Connect

Axion fluctuations generated during inflation lead to isocurvature and non-Gaussian temperature fluctuations in the cosmic microwave background radiation. Following a previous analysis for the model independent string axion we consider the consequences of a measurement of these fluctuations for two additional string axions. We do so independent of any cosmological assumptions except for the axions being massless during inflation. The first axion has been shown to solve the strong CP problem for most compactifications of the heterotic string while the second axion, which does not solve the strong CP problem, obeys a mass formula which is independent of the axion scale. We find that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of H{sub inf} {approx}> 10{sup 13} GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula. In an appendix we quantitatively justify the often held assumption that temperature corrections to the zero temperature QCD axion mass may be ignored for temperatures T {approx}< {Lambda}{sub QCD}.

Kain, Ben

2005-12-15T23:59:59.000Z

154

Calculating bed load transport in steep boulder bed channels E. M. Yager,1,2  

E-Print Network (OSTI)

Calculating bed load transport in steep boulder bed channels E. M. Yager,1,2 J. W. Kirchner,1 and W: Yager, E. M., J. W. Kirchner, and W. E. Dietrich (2007), Calculating bed load transport in steep boulder, more mobile sediment and large, relatively immobile boulders that are often arranged into cascades

Kirchner, James W.

155

Attrition of coal ash particles in a fluidized-bed reactor  

SciTech Connect

Experimental data of ash-particles attrition in a fluidized bed is presented, and also the results of modeling. Five sizes of ash particles (1.02-1.25; 1.25-1.6; 1.6-2.0; 2.0-5.0; 5.0-10.0 mm) produced in an industrial CFB boiler were examined. A new model of mechanical attrition has been proposed which incorporates new parameters: the shape factor of particles and the ratio of the bed height to bed diameter, strongly influencing the rate of bed mass loss. The model describes very well experimental data for coal-ash particles attrition. The attrition-rate coefficient for ash particles was evaluated.

Tomeczek, J.; Mocek, P. [Silesian Technical University, Katowice (Poland)

2007-05-15T23:59:59.000Z

156

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...

Head, Katharine J.

2009-05-15T23:59:59.000Z

157

Ordered bed modular reactor design proposal  

SciTech Connect

The Ordered Bed Modular Reactor (OBMR) is a design as an advanced modular HTGR in which the annular reactor core is filled with an ordered bed of fuel spheres. This arrangement allows fuel elements to be poured into the core cavity which is shaped so that an ordered bed is formed and to be discharged from the core through the opening holes in the reactor top. These operations can be performed in a shutdown shorter time. The OBMR has the most of advantages from both the pebble bed reactor and block type reactor. Its core has great structural flexibility and stability, which allow increasing reactor output power and outlet gas temperature as well as decreasing core pressure drop. This paper introduces ordered packing bed characteristics, unloading and loading technique of the fuel spheres and predicted design features of the OBMR. (authors)

Tian, J. [Inst. of Nuclear Energy Technology, Tsinghua Univ., Beijing 100084 (China)

2006-07-01T23:59:59.000Z

158

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

SciTech Connect

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

159

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,

160

Fluidized bed heat treating system  

DOE Patents (OSTI)

Systems for heat treating materials are presented. The systems typically involve a fluidized bed that contains granulated heat treating material. In some embodiments a fluid, such as an inert gas, is flowed through the granulated heat treating medium, which homogenizes the temperature of the heat treating medium. In some embodiments the fluid may be heated in a heating vessel and flowed into the process chamber where the fluid is then flowed through the granulated heat treating medium. In some embodiments the heat treating material may be liquid or granulated heat treating material and the heat treating material may be circulated through a heating vessel into a process chamber where the heat treating material contacts the material to be heat treated. Microwave energy may be used to provide the source of heat for heat treating systems.

Ripley, Edward B; Pfennigwerth, Glenn L

2014-05-06T23:59:59.000Z

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.


161

Scaledown of three-phase ebullieted bed reactors for bitumen hydrotreating  

SciTech Connect

The length of a commercial reactor, in three-phase ebullieted bed processes with pelleted catalysts, for the processing of heavy oils, bitumen and bitumen-derived liquids are long due to the requirement oflow space velocities. The reactor length, for laboratory scale studies of such processes, can be reduced by reducing the superficial liquid velocity. Consequently, the catalyst size has to be reduced to achievecirculation within the reactor. It is important to ensure that, with these changes, the values of the phase holdups are maintained the same in the commercial and the laboratory units. Through extensive similitude studies, similarity criteria that would ensure identical holdups in the commercial and laboratory units were identified, which required the equality of six dimensionless numbers. These criteria were validated using the generalized wake model. It was found that it was impractical to establish all the parameters in the set of dimensionless numbers at the desired values. Therefore, a method to achieve similarity by varying a minimum number of parameters, such as liquid and gas velocities and particle size, was developed using the generalized wake model. This resulted in a set of two conditions, which when satisfied, yielded practically equal holdups in the two reactors.

Deshpande, D.A.; Deo, M.D.; Hanson, F.V.

1993-03-01T23:59:59.000Z

162

Scaledown of three-phase ebullieted bed reactors for bitumen hydrotreating  

SciTech Connect

The length of a commercial reactor, in three-phase ebullieted bed processes with pelleted catalysts, for the processing of heavy oils, bitumen and bitumen-derived liquids are long due to the requirement oflow space velocities. The reactor length, for laboratory scale studies of such processes, can be reduced by reducing the superficial liquid velocity. Consequently, the catalyst size has to be reduced to achievecirculation within the reactor. It is important to ensure that, with these changes, the values of the phase holdups are maintained the same in the commercial and the laboratory units. Through extensive similitude studies, similarity criteria that would ensure identical holdups in the commercial and laboratory units were identified, which required the equality of six dimensionless numbers. These criteria were validated using the generalized wake model. It was found that it was impractical to establish all the parameters in the set of dimensionless numbers at the desired values. Therefore, a method to achieve similarity by varying a minimum number of parameters, such as liquid and gas velocities and particle size, was developed using the generalized wake model. This resulted in a set of two conditions, which when satisfied, yielded practically equal holdups in the two reactors.

Deshpande, D.A.; Deo, M.D.; Hanson, F.V.

1993-01-01T23:59:59.000Z

163

Heat transfer characteristics of fluidized bed heat exchanger in a 300 MW CFB boiler  

Science Journals Connector (OSTI)

In order to investigate the heat transfer characteristics of fluidized bed heat exchanger (FBHE), a series of experiments was carried out in a commercial 300 MW circulating fluidized bed (CFB) boiler with FBHE. The parameters of steam, solids and air in FBHE were measured at different boiler loads, based on which the absorbed heat and heat transfer coefficient were calculated. Further study indicates that when the calculated results are applied to the design of large-scale CFB boilers, the bed side heat transfer coefficient in FBHE can be simplified as the function of solids temperature and flow. Therefore, the empirical model of heat transfer coefficient at bed side is put forward. The deviation between calculated results and measured values is acceptable in engineering application. This model provides strong support for the FBHE design in 600 MW supercritical CFB boilers.

Man Zhang; Haibo Wu; Qinggang Lu; Yunkai Sun; Guoliang Song

2012-01-01T23:59:59.000Z

164

Bed and bed-site reuse by western lowland gorillas (Gorilla g. gorilla) in Moukalaba-Doudou National Park, Gabon  

Science Journals Connector (OSTI)

In this paper we describe bed (nest) and bed-site reuse by western lowland gorillas (Gorilla g. gorilla...) in Moukalaba-Doudou National Park, south-eastern Gabon. During an eight-month study 44 bed...

Yuji Iwata; Chieko Ando

2007-01-01T23:59:59.000Z

165

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

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

SCADA Test Bed - Enhancing control systems security in the energy sector (September 2009) National SCADA Test Bed - Enhancing control systems security in the energy sector...

166

Tube construction for fluidized bed combustor  

DOE Patents (OSTI)

A fluidized bed combustor comprises a reactor or a housing which has a windbox distributor plate adjacent the lower end thereof which contains a multiplicity of hole and air discharge nozzles for discharging air and coal into a fluidized bed which is maintained above the distributor plate and below a take-off connection or flue to a cyclone separator in which some of the products of combustion are treated to remove the dust which is returned into the fluidized bed. A windbox is spaced below the fluidized bed and it has a plurality of tubes passing therethrough with the passage of combustion air and fluidizing air which passes through an air space so that fluidizing air is discharged into the reaction chamber fluidized bed at the bottom thereof to maintain the bed in a fluidized condition. A fluid, such as air, is passed through the tubes which extend through the windbox and provide a preheating of the combustion air and into an annular space between telescoped inner and outer tubes which comprise heat exchanger tubes or cooling tubes which extend upwardly through the distributor plate into the fluidized bed. The heat exchanger tubes are advantageously arranged so that they may be exposed in groups within the reactor in a cluster which is arranged within holding rings.

De Feo, Angelo (Totowa, NJ); Hosek, William (Mt. Tabor, NJ)

1984-01-01T23:59:59.000Z

167

Fluid-bed combustion of solid wastes  

SciTech Connect

For over ten years combustion Power Company has been conducting experimental programs and developing fluid bed systems for agencies of the federal government and for private industry and institutions. Many of these activities have involved systems for the combustion of solid waste materials. Discussed here will be three categories of programs, development of Municipal Solid Waste (MSW) fired fluid beds, development of wood waste fired fluid beds, and industrial installations. Research and development work on wood wastes has led to the design and construction of two large industrial fluid bed combustors. In one of these, a fluid bed is used for the generation of steam with a fuel that was previously suited only for landfill. Rocks and inerts are continuously removed from this combustor using a patented system. The second FBC is designed to use a variety of fuels as the source of energy to dry hog fuel for use in a high performance power boiler. Here the FBC burns green hog fuel, log yard debris, fly ash (char) from the boiler, and dried wood fines to produce a hot gas system for the wood dryer. A significant advantage of the fluidized bed reactor over conventional incinerators is its ability to reduce noxious gas emission and, finally, the fluidized bed is unique in its ability to efficiently consume low quality fuels. The relatively high inerts and moisture content of solid wastes pose no serious problem and require no associated additional devices for their removal.

Vander Molen, R.H.

1980-01-01T23:59:59.000Z

168

Fluidized bed combustor and tube construction therefor  

DOE Patents (OSTI)

A fluidized bed combustor comprises a reactor or a housing which has a windbox distributor plate adjacent the lower end thereof which contains a multiplicity of hole and air discharge nozzles for discharging air and coal into a fluidized bed which is maintained above the distributor plate and below a take-off connection or flue to a cyclone separator in which some of the products of combustion are treated to remove the dust which is returned into the fluidized bed. A windbox is spaced below the fluidized bed and it has a plurality of tubes passing therethrough with the passage of combustion air and fluidizing air which passes through an air space so that fluidizing air is discharged into the reaction chamber fluidized bed at the bottom thereof to maintain the bed in a fluidized condition. A fluid, such as air, is passed through the tubes which extend through the windbox and provide a preheating of the combustion air and into an annular space between telescoped inner and outer tubes which comprise heat exchanger tubes or cooling tubes which extend upwardly through the distributor plate into the fluidized bed. The heat exchanger tubes are advantageously arranged so that they may be exposed in groups within the reactor in a cluster which is arranged within holding rings.

De Feo, Angelo (Passaic, NJ); Hosek, William (Morris, NJ)

1981-01-01T23:59:59.000Z

169

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

170

Conductivity tracer studies for a fluidized-bed bioreactor  

SciTech Connect

An automated conductivity tracer test was developed to measure the residence time distribution (RTD) of a cometabolic fluidized-bed bioreactor (FBBR). The FBBR contained sand-core bioparticles grown with phenol and it provided high (70% to 80%) removal of trichloroethene (TCE) at short (3 minute) detention times. The tracer test apparatus was constructed with off-the-shelf components controlled with a PC-based data acquisition system. Non-disruptive hydrodynamic testing was obtained during normal operation of the FBBR. The conductivity of injected brine pulses was monitored at the reactor inlet and outlet. Dispersion numbers and detention times were computed by fitting the advection-dispersion model to the tracer curves. Typical dispersion numbers attributed to the fluidized-bed of bioparticles ranged from 0.07 to 0.11. In simplified modeling of the FBBR, dispersion was found to have little effect on TCE removal. Based on the dispersion of brine pulses, it was determined that phenol feed pulses injected at inhibitory concentrations over 2 g/L would be rapidly dispersed in the biological bed to non-inhibitory concentrations.

Leung, S.Y.; Segar, R.L. Jr. [Univ. of Missouri, Columbia, MO (United States). Dept. of Civil Engineering

1997-12-31T23:59:59.000Z

171

Chapter 14 - Coal bed methane  

Science Journals Connector (OSTI)

Publisher Summary Methane adsorbed to the surface of coal is a very old issue with some new commercial ramifications. This explosive gas has made underground coal mines dangerous both from the risk of explosion and the possibility of an oxygen-poor atmosphere that wouldn't support life. The miner's main concern with coal bed methane (CBM) has been how to get rid of it. Techniques to deal with CBM in mines have ranged from the classic canary in a cage to detect an oxygen-poor atmosphere to huge ventilation fans to force the replacement of a methane-rich environment with outside air, to drilling CBM wells in front of the coal face to try to degas the coal prior to exposing the mine to the CBM. All these techniques have met with some amount of success. None of the techniques to prevent CBM from fouling the air in an underground mine has been totally successful. With the CBM's unique method of gas storage, the preponderance of the gas is available only to very low coalface pressures. The coalface pressure is set by a combination of flowing wellhead pressure and the hydrostatic head exerted by standing liquid within the well bore. Effective compression strategies can lower the wellhead pressure to very low values. Effective deliquification techniques can reduce or remove the backpressure caused by accumulated liquid. CBM's economic impact is briefly explained in this chapter.

James F. Lea; Henry V. Nickens; Mike R. Wells

2008-01-01T23:59:59.000Z

172

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

173

Biomass Gasification in Dual Fluidized Bed Gasifier  

Science Journals Connector (OSTI)

The dual fluidized bed gasification technology is prospective because it produces high...2...dilution even when air is used to generate the required endothermic heat via in situ combustion. This study is devoted ...

Toshiyuki Suda; Takahiro Murakami…

2007-01-01T23:59:59.000Z

174

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

175

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

176

Fluid Bed Combustion Applied to Industrial Waste  

E-Print Network (OSTI)

of its relatively recent application to coal fired steam production, fluid beds have been uti lized in industry for over 60 years. Beginning in Germany in the twenties for coal gasification, the technology was applied to catalytic cracking of heavy... system cost), use of minimum excess air required, and maintaining the min"imum reactor temperature neces sary to sustain combustion. For superautogenous fuels, where incineration. only is desired, minimum capital cost is achieved by using direct bed...

Mullen, J. F.; Sneyd, R. J.

177

consequence management | National Nuclear Security Administration  

National Nuclear Security Administration (NNSA)

consequence management consequence management Nuclear Forensics The National Technical Nuclear Forensics (NTNF) program is a Homeland Security Council and National Security...

178

Evaluation of packed-bed and fluidized-bed cell technology for the destruction and removal of contaminants in alkaline waste solutions. Final report  

SciTech Connect

Disposing of the large quantity of nuclear waste that has been produced within the DOE complex is an area of active research and development. Electrochemical processes have been reported for the treatment of alkaline wastes including the destruction of nitrate and nitrite and the removal of metals such as Tc and Ru. Electrolytic recovery of metals from dilute solution has been reported using conventional porous electrodes such as felt electrode and reticulated electrode, but use of such electrodes is limited. The pores of such electrodes become blocked as a consequence of metal deposition. If an attempt is made to regenerate these electrodes by dissolution of the deposited metals, oxygen evolution on the matrix competes with dissolution of metals deposited within the pores. On the other hand, the use of three dimensional packed-bed and fluidized-bed electrodes having large surface area per unit volume would offer an improvement on felt or reticulated system because of the greater ease of regeneration.

Hobbs, D.T. [Westinghouse Savannah River Co., Aiken, SC (United States); Bockris, J.O.M.; Kim, Jinseong [Texas A& M Univ., College Station, TX (United States). Surface Electrochemistry Laboratory

1995-12-31T23:59:59.000Z

179

Effect of sediment pulse grain size on sediment transport rates and bed mobility in gravel bed rivers  

E-Print Network (OSTI)

Effect of sediment pulse grain size on sediment transport rates and bed mobility in gravel bed] Sediment supply to gravel bed river channels often takes the form of episodic sediment pulses, and there is considerable interest in introducing sediment pulses in stream restorations to alter bed surface grain size

Venditti, Jeremy G.

180

A study on the dynamic combustion behavior of a biomass fuel bed  

Science Journals Connector (OSTI)

Abstract The main objective of this research was to study fuel bed combustion dynamics of a BioGrate boiler with a mechanistic model. First, the fuel specific pyrolysis reaction rates were experimentally determined for the model. Second, the model was validated and finally, it was used to investigate the effects of the primary air flows on drying, pyrolysis and char consumption rates occurring inside the fuel bed. The research results are presented and the role of the dynamic behavior of the reactions on the biomass combustion process discussed.

Alexandre Boriouchkine; Vida Sharifi; Jim Swithenbank; Sirkka-Liisa Jämsä-Jounela

2014-01-01T23:59:59.000Z

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.


181

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

182

Treatment of septage in sludge drying reed beds: a case study on pilot-scale beds  

E-Print Network (OSTI)

Treatment of septage in sludge drying reed beds: a case study on pilot-scale beds S. Troesch***, A systems by local authorities. This will result in a large increase of the quantity of sludge from septic to treat this sludge because they may have reached their nominal load or they are not so numerous in rural

Paris-Sud XI, Université de

183

Probabilistic Representation of the Threat and Consequences of Weapon Attacks on Commercial  

E-Print Network (OSTI)

Probabilistic Representation of the Threat and Consequences of Weapon Attacks on Commercial of the Threat and Consequences of Weapon Attacks on Commercial Aircraft CREATE Report 29 November 2005 John P FLIGHT PATH . . . . . . . . . . . . . . . . . . . . . . . . . . 20 WEAPON LETHALITY MODEL

Wang, Hai

184

Fluid bed gasification – Plasma converter process generating energy from solid waste: Experimental assessment of sulphur species  

SciTech Connect

Highlights: • We investigate gaseous sulphur species whilst gasifying sulphur-enriched wood pellets. • Experiments performed using a two stage fluid bed gasifier – plasma converter process. • Notable SO{sub 2} and relatively low COS levels were identified. • Oxygen-rich regions of the bed are believed to facilitate SO{sub 2}, with a delayed release. • Gas phase reducing regions above the bed would facilitate more prompt COS generation. - Abstract: Often perceived as a Cinderella material, there is growing appreciation for solid waste as a renewable content thermal process feed. Nonetheless, research on solid waste gasification and sulphur mechanisms in particular is lacking. This paper presents results from two related experiments on a novel two stage gasification process, at demonstration scale, using a sulphur-enriched wood pellet feed. Notable SO{sub 2} and relatively low COS levels (before gas cleaning) were interesting features of the trials, and not normally expected under reducing gasification conditions. Analysis suggests that localised oxygen rich regions within the fluid bed played a role in SO{sub 2}’s generation. The response of COS to sulphur in the feed was quite prompt, whereas SO{sub 2} was more delayed. It is proposed that the bed material sequestered sulphur from the feed, later aiding SO{sub 2} generation. The more reducing gas phase regions above the bed would have facilitated COS – hence its faster response. These results provide a useful insight, with further analysis on a suite of performed experiments underway, along with thermodynamic modelling.

Morrin, Shane, E-mail: shane.morrin@ucl.ac.uk [Department of Chemical Engineering, University College London, London WC1E 7JE (United Kingdom); Advanced Plasma Power, Swindon, Wiltshire 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, Swindon, Wiltshire SN3 4DE (United Kingdom); Taylor, Richard, E-mail: richard.taylor@app-uk.com [Advanced Plasma Power, Swindon, Wiltshire SN3 4DE (United Kingdom)

2014-01-15T23:59:59.000Z

185

A novel reactor configuration for packed bed chemical-looping combustion of syngas  

Science Journals Connector (OSTI)

Abstract This study reports on the application of chemical looping combustion (CLC) in pressurized packed bed reactors using syngas as a fuel. High pressure operation of CLC in packed bed has a different set of challenges in terms of material properties, cycle and reactor design compared to fluidized bed operation. However, high pressure operation allows the use of inherently more efficient power cycles than low pressure fluidized bed solutions. This paper quantifies the challenges in high pressure operation and introduces a novel reactor concept with which those challenges can be addressed. Continuous cyclic operation of a packed bed CLC system is simulated in a 1D numerical reactor model. Importantly, it is demonstrated that the temperature profiles that can occur in a packed bed reactor as a result of the different process steps do not accumulate, and have a negligible effect on the overall performance of the system. Moreover, it has been shown that an even higher energy efficiency can be achieved by feeding the syngas from the opposite direction during the reduction step (i.e. countercurrent operation). Unfortunately, in this configuration mode, more severe temperature fluctuations occur in the reactor exhaust, which is disadvantageous for the operation of a downstream gas turbine. Finally, a novel reactor configuration is introduced in which the desired temperature rise for obtained hot pressured air suitable for a gas turbine is obtained by carrying out the process with two packed bed reactor in series (two-stage CLC). This is shown to be a good alternative to the single bed configuration, and has the added advantage of decreasing the demands on both the oxygen carrier and the reactor materials and design specification.

H.P. Hamers; F. Gallucci; P.D. Cobden; E. Kimball; M. van Sint Annaland

2013-01-01T23:59:59.000Z

186

Bed material agglomeration during fluidized bed combustion. Technical progress report, September 30, 1992--December 31, 1992  

SciTech Connect

The purpose of this project is to determine the physical and chemical reactions which led to the undesired agglomeration of bed material during fluidized bed combustion and to relate these reactions to specific causes. Survey of industrial-scale fluidized bed combustors is being conducted to determine the occurrence of bed agglomeration and the circumstances under which agglomeration took place. This task should be finished by the end of February. Samples of bed material, agglomerate material, and boiler deposits are being requested from boiler operators as part of the survey. Once received, these sample will be analyzed to determine chemical and mineralogic composition. The bulk chemical determination will be performed using x-ray fluorescence and inductively coupled plasma-optical emission (ICP). Mineralogy will be detected by x-ray diffraction (XRD). Chemical and mineral reactions will be determined by scanning electron microscopy, optical microscopy, and electron microprobe.

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

1993-02-01T23:59:59.000Z

187

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

188

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

SciTech Connect

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

189

Dynamic simulation of integrated rock-bed thermocline storage for concentrated solar power  

Science Journals Connector (OSTI)

Abstract In contrast to wind and photovoltaic, concentrated solar power plants can be equipped with thermal energy storage in order to decouple intermittent energy supply and grid feed-in. The focus of this study is the technical evaluation of a cost-efficient storage concept for solar tower power plants. Consisting of a quartzite-rock bed that is charged with a hot air flow and discharged by cold air counter-flow, the storage essentially operates like a regenerator. For such systems, the discharge temperature typically declines with time. Furthermore, the use of a randomly packed bed results in considerable pressure loss. In order to describe the relevant flow and heat transfer mechanisms in rock beds used for thermal storage, a mathematical model written in the modelling language Modelica is developed and validated. Good agreement with experimental data from literature is obtained. With the aid of the validated model, a rock-bed thermal storage for application in a semi-industrial scale solar power plant (1.5 MWel) is designed and optimised with respect to electrical efficiency of the plant during the charge and discharge cycle. The storage capacity is equivalent to four hours of full-load operation. Results show that compressor work should be considered directly in the selection of packed-bed geometry in order to minimise the efficiency penalty of storage integration in the solar plant.

Nicolas Mertens; Falah Alobaid; Lorenz Frigge; Bernd Epple

2014-01-01T23:59:59.000Z

190

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

191

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

192

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 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

193

Fluidized bed combustion picks up steam  

SciTech Connect

Industrial interest in fluidized-bed combustion (FBC) continues, although the technology has been slow to enter the marketplace. Two FBC pilot plants funded by DOE and one commercial size project are in operation. FBC designs and commercial warranties are already available from the boiler industry, but 1981 was the first year to see significant numbers of privately-funded orders, now numbering 38 out of 50 boilers. Manufacturers are working on a universal boiler able to accept any fuel, but potential users are wary of new technology without a long-term demonstration of reliability and economics. There is interest in second generation designs, a new shallow-bed design suitable for retrofitting, and circulating bed types that decouple the combustion system from the heat removal system. (DCK)

Lawn, J.

1982-02-01T23:59:59.000Z

194

E-Print Network 3.0 - atmospheric fluidized bed Sample Search...  

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

conditions... in a fluidized bed coater. The bed relative humidity and the droplet size of the coating aerosol were predicted... Fluidized bed coating ... Source: Groningen,...

195

Exergy analysis of a rock bed thermal storage system  

Science Journals Connector (OSTI)

In this paper, a thermodynamic procedure is presented to analyse energy and exergy balances of a rock bed thermal storage system. The thermal behaviour is described by means of a control volume that includes three subsystems: the solar collectors, the fluid distribution system and the storage chamber. Solar-to-thermal energy conversion was obtained by means of a solar collector at a fixed airflow rate. The final purpose of the method is to determine how well the thermodynamic modelling fits the real data obtained experimentally from the prototype under normal operating conditions.

J.J. Navarrete-Gonzalez; J.G. Cervantes-de Gortari; E. Torres-Reyes

2008-01-01T23:59:59.000Z

196

Evaluating the fluidized bed combustion options  

SciTech Connect

The proceedings from a conference on fluidized bed combustion are now available. The book discusses the immediate availability of atmospheric fluidized bed combustion technology as a practical, environmentally sound option for burning all grades of coal, wood, wood wastes, and biomass. The economics and technical fundamentals of atmospheric FBC are explained for the benefit of owners and managers of industrial boilers, boiler operators, architects/engineers, boiler manufacturers, and fuel suppliers. More than 15 FBC experts have contributed their expertise and experiences to the book.

Sheahan, R.T. (ed.)

1984-01-01T23:59:59.000Z

197

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

198

Bed load equation evaluation based on alluvial river data, India  

Science Journals Connector (OSTI)

The rate of bed load transport in weight per unit width for ... material has been computed by collecting the field data of Tapi River, in the monsoon season ... of this paper is to estimate the bed load carried b...

S. M. Yadav; B. K. Samtani

2008-11-01T23:59:59.000Z

199

Design of a Pilot Plant Fluidized Bed Gasifier  

Science Journals Connector (OSTI)

This article presents the design principles for a biomass fluidized bed gasifier pilot plant. The fluidized bed gasifier has a nominal capacity of 400 kg ... most important parameters for the performance of the gasifier

K. Maniatis; V. Vassilatos; S. Kyritsis

1993-01-01T23:59:59.000Z

200

Current Status and Challenges within Fluidized Bed Combustion  

Science Journals Connector (OSTI)

Fluidized-bed technology is rapidly expanding. Today, more than 600 large (20+ MWth) FBC boilers with a total installed thermal capacity of ... beds (BFBC). The size of the boilers has increased steeply; the larg...

Mikko Hupa

2007-01-01T23:59:59.000Z

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

Fluidized bed gasification of agricultural residue  

E-Print Network (OSTI)

studied to develop a process which can convert organic waste matter into fuel gas. Hammond et al. (1974) described a fixed bed gasifier which operated at 1800 F (1256 K) and atmos- pheric pressure. When woodchips were used as the feed material...

Groves, John David

1979-01-01T23:59:59.000Z

202

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

203

Bed Bugs: Clinical Relevance and Control Options  

Science Journals Connector (OSTI)

...the treatment of field infestations...95) and cedar oil. The modes of...Best Yet cedar oil can kill all bed...the control of field infestations...complexes, as the gas cannot be tightly...Insecticides The cost to develop and...insects during spray operations. In laboratory...

Stephen L. Doggett; Dominic E. Dwyer; Pablo F. Peñas; Richard C. Russell

2012-01-01T23:59:59.000Z

204

Bed Bugs: Clinical Relevance and Control Options  

Science Journals Connector (OSTI)

...assist those who cannot pay the high price of control, bed bugs are set to...antigen and bronchial asthma in Egypt. J. Egypt. Soc. Parasitol. 21 : 735-746...Doggett, SL . 2009. Identification natural history, p 13-22. InSL Doggett...

Stephen L. Doggett; Dominic E. Dwyer; Pablo F. Peñas; Richard C. Russell

2012-01-01T23:59:59.000Z

205

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

206

Failure Analysis of Bed Coil Tube in an Atmospheric Fluidized Bed Combustion Boiler  

Science Journals Connector (OSTI)

The fluidized bed combustion (FBC) technology is being used in thermal power plants for steam generation. FBC plants are more flexible than conventional plants ... fuels may be used for firing. The FBC technology...

M. Venkateswara Rao; S. U. Pathak…

2014-06-01T23:59:59.000Z

207

Forecasting Hospital Bed Availability Using Simulation and Neural Networks  

E-Print Network (OSTI)

Forecasting Hospital Bed Availability Using Simulation and Neural Networks Matthew J. Daniels is a critical factor for decision-making in hospitals. Bed availability (or alternatively the bed occupancy in emergency departments, and many other important hospital decisions. To better enable a hospital to make

Kuhl, Michael E.

208

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

209

Microwave short-pulse bed-level detector. Annual report, January 1-December 31, 1981  

SciTech Connect

A short-pulse microwave system for measuring the bed-level within a fluidized-bed combustor, has been designed, built, and laboratory tested on static beds. The system is a short-pulse radar which operates in the frequency region of 6.75 to 10.95 GHz as a time-domain measurement system. Laboratory measurements of static bed-levels, for smooth and corrugated surfaces of metal plates and limestone sand, agree to an average of 2.0% of the actual heights. Additionally, the system was tested with a dielectric thermal protector, which did not compromise the accuracy of the measurements. Analytical models have been formulated to provide insight into the operation of the system on a wide range of simulated targets without the necessity of performing expensive and difficult laboratory experiments. Two formulations have been used to describe electromagnetic scattering by a rough surface as a function of frequency: the space harmonic model and the physical optics model. A reconstruction technique has been devised which uses the scattering models and the spectrum of the transmitted pulse to synthesize the reflected pulse. The data generated by the models compare well to previously published data and to experimental results.

Balanis, C.A.; Delauder, D.M.

1981-01-01T23:59:59.000Z

210

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

SciTech Connect

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

211

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

212

Numerical evaluation of the energetic performances of structured and random packed beds in regenerative thermal oxidizers  

Science Journals Connector (OSTI)

Regenerative thermal oxidizers (RTO) can be conveniently used to control volatile organic components (VOC) emissions, because of their thermal efficiency and cost effectiveness. In the RTO technology, beds of inert material are used in order to heat the polluted air by cooling burnt gases, through a sequence of cyclic operations which cut the fuel requirements. A computational 1D unsteady model, able to account for both structured and random packed bed regenerators, is developed and applied to realistic plant conditions. Process thermal efficiency and gas pressure drop are calculated as functions of the system geometry and operating parameters. The code can be usefully employed in the analysis and design of RTO systems and in order to choose the more suitable type of regenerator, structured or random packed bed (even considering various particle shapes). Energetic performances of both random and structured regenerators were compared, showing that the first ones exhibit a little higher thermal efficiency but also an elevated pressure drop, at a same value of exchange surface per unit volume of the bed. Random packed bed regenerators resulted less attractive from the energetic point of view and their usage is advisable if their lower cost satisfy economical requirements.

Mario Amelio; Pietropaolo Morrone

2007-01-01T23:59:59.000Z

213

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

214

Transient Simulations of Spouted Fluidized Bed for Coal-Direct Chemical Looping Combustion  

Science Journals Connector (OSTI)

Transient Simulations of Spouted Fluidized Bed for Coal-Direct Chemical Looping Combustion ... Instead of having air to support the combustion process, an oxygen compound (metal or non-metal based) is used as an oxidizer in the fuel reactor; thus, the fuel is chemically combusted by the metal oxide than the oxygen present in air in case of standard power plants. ... The CFD/DEM simulation approach has been used in various applications which require the modeling of particle/fluid interaction;(19-23) however, its application in the context of close-loop spouted fluidized bed system has so far been quite limited and preliminary. ...

Zheming Zhang; Ling Zhou; Ramesh Agarwal

2014-01-28T23:59:59.000Z

215

MTG process in a fluidized bed with catalyst circulation: Operation and simulation of an experimental unit  

SciTech Connect

The simulation of the MTG process has been studied in a fluidized bed with circulation of the catalyst (prepared based on a HZSM-5 zeolite). The simulation has been carried out by taking into account the activity distribution of the catalyst particles in the bed and by using experimentally determined kinetic models for the reaction at zero time on stream and for the catalyst deactivation. The results of the simulation have been proven in an experimental laboratory unit by operating in the range between 380 and 420 C, with different values of space time and of average residence time of the catalyst.

Ortega, J.M.; Gayubo, A.G.; Aguayo, A.T.; Olazar, M.; Bilbao, J. [Univ. del Pais Vasco, Bilbao (Spain). Dept. de Ingenieria Quimica] [Univ. del Pais Vasco, Bilbao (Spain). Dept. de Ingenieria Quimica

1998-11-01T23:59:59.000Z

216

Analysis and control of the METC fluid bed gasifier. Quarterly report, April 1995--June 1995  

SciTech Connect

This document summarizes work performed for the period 4/1/95 to 7/31/95 on contract no. DE-FG21-94MC31384 (Work accomplished during the period 10/1/94 to 3/31/94 was summarized in the previous technical progress report included in the appendix of this report). In this work, three components will form the basis for design of a control scheme for the Fluidized Bed Gasifier (FBG) at METC: (1) a control systems analysis based on simple linear models derived from process data, (2) review of the literature on fluid bed gasifier operation and control, and (3) understanding of present FBG operation and real world considerations. Tasks accomplished during the present reporting period include: (1) Completion of a literature survey on Fluid Bed Gasifier control, (2) Observation of the FBG during the week of July 17 to July 21, and (3) Suggested improvements to the control of FBG backpressure and MGCR pressure.

NONE

1995-06-01T23:59:59.000Z

217

The development of an integrated multistage fluid bed retorting process. [Kentort II process  

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 April 1, 1992 through June 30, 1992. 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 raw oil shale sample for the program was mined, prepared, characterized and stored this quarter. The shale that was chosen was from the high-grade zone of the Devonian Cleveland Member of the Ohio Shale in Montgomery County, Kentucky. The shale was mined and then transported to the contractor's crushing facility where it was crushed, double-screened, and loaded into 85 55-gal barrels. The barrels, containing a total of 25-30 tons of shale, were transported to the (CAER) Center for Applied Energy Research where the shale was double-screened, analyzed and stored. A major objective of the program is the study of solid-induced secondary coking and cracking reactions. A valved fluidized bed reactor has been the primary apparatus used for this study prior to this quarter, but two additional techniques have been initiated this quarter for the study of other aspects of this issue. First, the two-stage hydropyrolysis reactor at the University of Strathclyde, Glasgow, Scotland, was used to study the coking tendency of shale oil vapors under a wide range of pyrolysis and hydropyrolysis conditions. This work enabled us to examine secondary reactions under high pressure conditions (up to 150 bar) which were previously unavailable. Second, the development of a fixed bed reactor system was initiated at the CAER to study the coking and cracking characteristics of model compounds. A fixed bed apparatus was necessary because the conversion of model compounds was too low in the fluidized bed apparatus.

Carter, S.D.; Taulbee, D.N.; Robl, T.L.; Hower, J.C.

1992-08-01T23:59:59.000Z

218

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

219

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

220

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.


221

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

222

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

223

Experimental Investigation into a Packed Bed Thermal Storage Solution for Solar Gas Turbine Systems  

Science Journals Connector (OSTI)

Abstract High temperature thermal storage in randomly packed beds of ceramic particles is proposed as an effective storage solution for Solar Gas Turbine (SGT) cycles in the near term. Numerical modelling of these systems allows for optimised thermal storage designs, but such models must be validated against experimental data. In this work an experimental test programme was conducted to generate high temperature heat transfer data for a packed bed operating over the temperature ranges 350-900 °C and 600-900 °C. These are representative of two potential SGT cycles. Flue gas from a 45 kW LPG burner was used to heat a packed bed of Denstone ceramic pebbles and the testing procedure involved preheating the system to achieve the desired temperature ranges. The fluid and solid temperature profiles in the packed bed were measured in the axial and radial dimensions and are compared to a numerical model with reasonable agreement. Potential modifications to the test facility are described and future testing plans outlined.

P. Klein; T.H. Roos; T.J. Sheer

2014-01-01T23:59:59.000Z

224

On the Consequences of Eliminating Capital Tax Differentials  

E-Print Network (OSTI)

to eliminate these differentials. This paper analyzes the consequences of such a reform using an incomplete markets model with equipment-skill complementarity. We find that the reform increases average welfare by approximately 0.1%. Importantly, we find that the reform does not involve the usual efficiency vs. equality

Yanikoglu, Berrin

225

Consequences for living resources and ecosystems  

Science Journals Connector (OSTI)

al hypoxia: Consequences for living resources and ecosys- tems. Coastal and Estuarine Studies, 58. American Geophysi- cal Union, Washington, D.C. vii + 463

2002-06-20T23:59:59.000Z

226

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

227

A new bed elevation dataset for Greenland  

E-Print Network (OSTI)

ice penetrating radar (IPR) systems. As a consequence, wefrom a number of airborne IPR missions have been col- lated,added for years between the IPR acquisition date and the

2013-01-01T23:59:59.000Z

228

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

229

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

230

Utilization of ash from fluidized bed boilers  

SciTech Connect

Combustion ash from a fluidized bed combustion (FBC) boiler contains not only carbon, but also silica alumina, quicklime as a sorbent, and a calcium sulfate by-product. These substances react chemically during fluidized bed combustion, and with the addition of water, they start an ettringite reaction and solidify. We determined the conditions necessary for producing hard solids through the study of the composition, curing methods, and characteristics of the solidified ash. We then used two types of road base material, crushed stone and solidified ash from an FBC boiler, to construct a test road at a site with a great deal of heavy traffic. Construction began in 1985, and since then, periodic tests have been performed to evaluate the performance of the road base materials. The testing of the manufacturing techniques centered on the amount and manner that water was added to the mixture and the curing methods of the mixture. Additional testing focused on the handling of the ash powder, the mixtures, and the solidified ash. Since 1991, under the sponsorship of MITI, the Center for Coal Utilization, in conjunction with Naruto Salt Mfg., Ltd., Nippon Hodo Co., Ltd., and Kawasaki Heavy Industries, Ltd., has used the referenced results to undertake a joint research and development project aimed at the eventual practical application of the technology. In 1993, a pilot facility to solidify ash with the fluidized bed boiler of 75 t/h capacity was completed. At present, all the discharged ash from the pilot facility is being solidified, and experiments on solidification and road base application techniques are underway. Actual road base tests are also in progress, and we are continuing research to meet the national certification requirements for road base materials.

Takada, Tomoaki [Kawasaki Heavy Industries Co., Ltd., Akashi (Japan)

1994-12-31T23:59:59.000Z

231

Second-generation pressurized fluidized bed combustion  

SciTech Connect

Under the sponsorship of the United States Department of Energy, Foster Wheeler Corporation is developing second-generation pressurized fluidized bed combustion (PFBC) power plant technology that will enable this type of plant to operate with net plant efficiencies in the range of 43 to 46 percent (based on the higher heating value of the coal), with a reduction in the cost of electricity of at least 20 percent. A three-phase program is under way. Its scope encompasses the conceptual design of a commercial plant through the process of gathering needed experimental test data to obtain design parameters.

Wolowodiuk, W.; Robertson, A.

1992-01-01T23:59:59.000Z

232

Second-generation pressurized fluidized bed combustion  

SciTech Connect

Under the sponsorship of the United States Department of Energy, Foster Wheeler Corporation is developing second-generation pressurized fluidized bed combustion (PFBC) power plant technology that will enable this type of plant to operate with net plant efficiencies in the range of 43 to 46 percent (based on the higher heating value of the coal), with a reduction in the cost of electricity of at least 20 percent. A three-phase program is under way. Its scope encompasses the conceptual design of a commercial plant through the process of gathering needed experimental test data to obtain design parameters.

Wolowodiuk, W.; Robertson, A.

1992-05-01T23:59:59.000Z

233

Particle Receiver Integrated with Fludized Bed  

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

This fact sheet describes a project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program to NREL which features a particle receiver with a fluidized bed. The research team is working to develop a technology that uses gas/solid, two-phase flow as a heat-transfer fluid and separated, stable, solid particles as a thermal energy storage medium. This project provides a pathway for CSP plants to increase their solar-to-electric conversion efficiency and reduce costs in the areas of solar collection from the solar field to the receiver, energy conversion systems, and thermal energy storage.

234

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

235

Integrated Gasification Combined Cycle Based on Pressurized Fluidized Bed Gasification  

Science Journals Connector (OSTI)

Enviropower Inc. has developed a modern power plant concept based on an integrated pressurized fluidized bed gasification and gas turbine combined cycle (IGCC)....

Kari Salo; J. G. Patel

1997-01-01T23:59:59.000Z

236

German Pebble Bed Research Reactor Highly Enriched Uranium (HEU...  

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

Potential Acceptance and Disposition of German Pebble Bed Research Reactor Highly Enriched Uranium (HEU) Fuel Environmental Assessment Maxcine Maxted, DOE-SR Used Nuclear Fuel...

237

Growth and flowering of bedding plants grown in landscape bed amended with hydrophilic polymers  

E-Print Network (OSTI)

Field study one incorporated hydrophilic polymers into field plots of bedding plants including 25, 50, 75, or 1 00 lb/1 00oft2 . Data recorded during the growing season included flower number, visual rating, soil moisture and temperature, and plant...

Boatright, Jennifer Lynn

1994-01-01T23:59:59.000Z

238

What is a bed bug? Bed bugs are small, oval, reddish brown, non-  

E-Print Network (OSTI)

zippers. Thus, experts recommend using hard luggage that closes tight. ·Protectyourclothes. Seal your clothes inside air-tight bags. ·Protectyourluggage. Never set your luggage on the bed or on a couch. Put. ·Treatyourluggagebeforeyoustoreit. After you have unpacked, vacuum your luggage thoroughly. Also, if it is hot outside, you can seal

Almor, Amit

239

Catalyst deactivation by coking in the MTG process in fixed and fluidized bed reactors  

Science Journals Connector (OSTI)

The validity of a kinetic model for describing the deactivation of a catalyst based on a HZSM5 zeolite has been studied by carrying out reaction in fixed and fluidized bed reactors. The kinetic model takes into account that activity is dependent on the concentration of the lumps of oxygenates, of light olefins and of the remaining products and shows that coke formation capability follows this order. The difference between the deactivation kinetic constants calculated for the fixed and fluidized bed reactors is explained by the effect of the steam produced in the reaction, where coke stripping attenuates deactivation. Future improvements in the deactivation kinetic model must take into account coke stripping by the steam produced in the reaction.

Andrés T. Aguayo; Ana G. Gayubo; JoséM. Ortega; Martin Olazar; Javier Bilbao

1997-01-01T23:59:59.000Z

240

Proceedings of the 1987 international conference on fluidized bed combustion: FBC comes of age  

SciTech Connect

This book presents the papers given at a conference on fluidized-bed combustors. Topics considered at the conference included fluidized bed boilers for utility applications, coal-fired systems, boiler retrofit, demonstration programs, atmospheric fluidized bed applications at the Tennessee Valley Authority, pressurized fluidized bed applications, waste disposal, adsorbents, fluid mechanics in fluidized beds, hydrodynamics, desulfurization, environmental issues, and advanced concepts.

Mustonen, J.P.

1987-01-01T23:59:59.000Z

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

Conceptual design of a Ni-based chemical looping combustion process using fixed-beds  

Science Journals Connector (OSTI)

Abstract This work presents a comprehensive conceptual design of a Ni-based chemical looping combustion process (CLC) carried out in fixed bed reactors. The process is intended to exploit the well-known advantages of the Ni/NiO redox system for CLC applications in terms of high reactivity, O2 carrying capacity and chemical and thermal stability. Solutions to the problem of heat management in fixed bed reactors at high temperature and high pressure are described, while a continuous flow of nitrogen for driving a gas turbine is produced. Each reactor involved in the process goes through a cyclic sequence of five reaction and heat transfer stages. Cool product gas recirculations are incorporated into the Ni oxidation and NiO reduction stages in order to moderate the maximum temperatures in the beds and control the displacement of the reaction and heat transfer fronts. A preliminary conceptual design of the process has been carried out to determine the minimum number of reactors needed for continuous operation in typical large-scale CO2 capture systems. Basic reactor models and assumptions based on an ideal plug flow pattern have been used in all the reactors during the chemical reactions and the heat transfer operations. This has made it possible to identify reasonable operating windows for the eight fixed-bed reactors that make up the CO2 capture system, and has demonstrated not only its technical viability but also its great potential for further development.

J.R. Fernández; J.C. Abanades

2014-01-01T23:59:59.000Z

242

Creating a coal bed Geographic Information System (GIS) for West Virginia  

SciTech Connect

The goal of the Coal Bed Mapping Project at the West Virginia Geological and Economic Survey is to produce an accurate Geographic Information System (GIS)-based inventory of the coal beds of West Virginia. GIS computer technology provides new and powerful ways to create, display, and analyze coal information. Geologists are creating maps depicting various aspects of West Virginia coal beds using a system of networked PCs and engineering layers or coverages, include: a structural model, the outcrop, the areas mined by surface, auger, and underground methods, coal isopach, and locations of samples taken for chemical analysis. Mapping is organized around the 7.5-minute quadrangles. Once significant numbers of contiguous quadrangles are mapped, GIS gives the users flexibility to view the information in different combinations of coverages, for any desired geographic window, at any scale. Coverages are designed to take advantage of the analytical capabilities inherent in GIS technology. The coal bed coverages will have significant value to West Virginia and its citizens. For example, potential uses include a compliance tool for the mineral lands tax program, coal resource estimates, subsidence risk assessment and amelioration, planning and development, and mine permitting and regulation.

Fedorko, N.; Blake, B.M.; McColloch, G.H.; Timberlake, K.J. [West Virginia Geological and Economic Survey, Morgantown, WV (United States)

1996-12-31T23:59:59.000Z

243

An analysis of ilmenite particles used as bed material for combustion of biomass in a CFB boiler.  

E-Print Network (OSTI)

??Combustion of biomass in a fluidized bed boiler with silica sand as bed material is related to problems such as agglomeration of bed material and… (more)

Corcoran, Angelica

2013-01-01T23:59:59.000Z

244

Rough Truth, Consequence, Consistency and Belief Revision  

Science Journals Connector (OSTI)

The article aims at re-visiting the notion of rough truth...proposed by Pawlak in 1987 [11] and investigating some of its ‘logical’ consequences. We focus on the formal deductive apparatus... ...

Mohua Banerjee

2004-01-01T23:59:59.000Z

245

The Institutional Consequences of Congressional Polarization  

E-Print Network (OSTI)

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...

Ilderton, Nathan A.

2010-07-14T23:59:59.000Z

246

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

247

Theory of free surface flow over rough seeping beds  

Science Journals Connector (OSTI)

...horizontal bed is assumed to be rough consisting of sediment...the other hand, in the rough flow regime (Re *70...the introduction, the set of equations (3.2...turbulent flow over a rough planar sand bed. The...The flow conditions were set in such a way that sediment...

2007-01-01T23:59:59.000Z

248

E-Print Network 3.0 - architecture test bed Sample Search Results  

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

test bed Search Powered by Explorit Topic List Advanced Search Sample search results for: architecture test bed Page: << < 1 2 3 4 5 > >> 1 Web-Based Test Bed for Fingerprint Image...

249

Development of Catalytic Tar Decomposition in an Internally Circulating Fluidized-Bed Gasifier  

Science Journals Connector (OSTI)

Biomass gasification in an Internally Circulating Fluidized-bed Gasifier (ICFG) using Ni/Ah03 as tar ... as catalyst in a lab-scale fluidized bed gasifier with catalyst fixed bed. The new catalyst...

Xianbin Xiao; Due Dung Le; Kayoko Morishita…

2010-01-01T23:59:59.000Z

250

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

251

Methods of forming a fluidized bed of circulating particles  

DOE Patents (OSTI)

There is disclosed an apparatus for forming a fluidized bed of circulating particles. In an embodiment, the apparatus includes a bottom portion having a sidewall, the sidewall defining a curvilinear profile, and the bottom portion configured to contain a bed of particles; and a gas inlet configured to produce a column of gas to carry entrained particles therein. There is disclosed a method of forming a fluidized bed of circulating particles. In an embodiment, the method includes positioning particles within a bottom portion having a sidewall, the sidewall defining a curvilinear profile; producing a column of gas directed upwardly through a gas inlet; carrying entrained particles in the column of gas to produce a fountain of particles over the fluidized bed of circulating particles and subside in the particle bed until being directed inwardly into the column of gas within the curvilinear profile.

Marshall, Douglas W. (Blackfoot, ID)

2011-05-24T23:59:59.000Z

252

Infrared thermography for laser-based powder bed fusion additive manufacturing processes  

SciTech Connect

Additive manufacturing (AM) has the potential to revolutionize discrete part manufacturing, but improvements in processing of metallic materials are necessary before AM will see widespread adoption. A better understanding of AM processes, resulting from physics-based modeling as well as direct process metrology, will form the basis for these improvements. Infrared (IR) thermography of AM processes can provide direct process metrology, as well as data necessary for the verification of physics-based models. We review selected works examining how IR thermography was implemented and used in various powder-bed AM processes. This previous work, as well as significant experience at the National Institute of Standards and Technology in temperature measurement and IR thermography for machining processes, shapes our own research in AM process metrology with IR thermography. We discuss our experimental design, as well as plans for future IR measurements of a laser-based powder bed fusion AM process.

Moylan, Shawn; Whitenton, Eric; Lane, Brandon; Slotwinski, John [National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899 (United States)

2014-02-18T23:59:59.000Z

253

Settlement of footing on compacted ash bed  

SciTech Connect

Compacted coal ash fills exhibit capillary stress due to contact moisture and preconsolidation stress due to the compaction process. As such, the conventional methods of estimating settlement of footing on cohesionless soils based on penetration tests become inapplicable in the case of footings on coal ash fills, although coal ash is also a cohesionless material. Therefore, a method of estimating load-settlement behavior of footings resting on coal ash fills accounting for the effect of capillary and preconsolidation stresses is presented here. The proposed method has been validated by conducting plate load tests on laboratory prepared compacted ash beds and comparing the observed and predicted load-settlement behavior. Overestimation of settlement greater than 100% occurs when capillary and preconsolidation stresses are not accounted for, as is the case in conventional methods.

Ramasamy, G.; Pusadkar, S.S. [IIT Roorkee, Roorkee (India). Dept. of Civil Engineering

2007-11-15T23:59:59.000Z

254

Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion (FBC) system. Technical progress report No. 2, [January 1, 1993--March 31, 1993  

SciTech Connect

This technical report summarizes the research work performed and the progress achieved during the period of January 1, 1993 to March 31, 1993. The prototype dust collector as a part of the exhaust system was designed and fabricated to perform the well-controlled test in the bench-scale FBC system. The instrumentation for flow-measuring has been conducted in the system, which includes the minimum fluidization velocity and bed-pressure drop, mean gas velocity, calculation of particle terminal velocity and its operating range, and static pressure distribution in the system. The bubble velocity was also predicted. The project has been progressing well. Future efforts will be concentrated on instrumentation for erosion-measuring. In addition to that, instrumentation for flow-measuring will be continued to support the erosion-measuring. Theoretical analysis and modeling on in-bed tube erosion will be initiated along with the experimental results. Experience and observation of in-bed tube erosion will be predicted.

Lee, Seong W.

1993-06-01T23:59:59.000Z

255

The effect of velocity and porosity profiles on the performance of fixed bed reactors  

E-Print Network (OSTI)

reactors. The reaction systems chosen offered a variety of reaction situations, including highly exothermic reactions, multiple and complex reaction schemes. A comparison of the calculated results by the two dimensional plug flow mcdel and the results... to be independent of axial direction in a bed packed with uniform size cylindrical or spherical particles. Martin(1978), using this data proposed a model for the porosity profile. Catalytic reactors are usually packed by uniform size spherical or cylindrical...

Amin, Kaushik

2012-06-07T23:59:59.000Z

256

Sensitive response of the Greenland Ice Sheet to surface melt drainage over soft bed  

E-Print Network (OSTI)

by detailed energy balance observations. The Cryosphere 6, 199-209, doi:doi:10.5194/tc-6-199-2012 (2012). ... by frictional and geothermal heating accumulates at the 136 bed over the course of winter and is released together with the first SGL drainage 137 events. With either one of these factors included, our model was able to reproduce the 138 2010 spring...

Bougamont, M H; Christoffersen,P.; Hubbard, A. L.; Fitzpatrick, A. A.; Doyle, S. H.; Carter, S. P.

2014-09-29T23:59:59.000Z

257

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

SciTech Connect

During this quarter, agglomerates which formed in the FBC at Montana-Dakota Utilities (Heskett Station Unit 2 located in Bismarck, ND) were analyzed by x-ray diffraction analyses (XRD) for mineral determination; bulk chemical composition was determined by inductively coupled plasma spectroscopy; and polished sections were made for optical and scanning electron microscopy. Polarized-light microscopy was performed using a Zeiss research microscope. Individual mineral grains were analyzed using an ARL electron microprobe and a JOEL 840 scanning electron microscope. The agglomerate was found in the mechanical dust collector and was about ten centimeters in diameter with a dark-colored core and a greenish rim. The sample had voids up to ten millimeters in size; however, the agglomerate was hard to break apart. Bulk compositionally, the agglomerate consists primarily of calcium, silica, and alumina with relatively high abundances of iron (8 to 9 wt %), magnesium (5 to 9 wt %) and sodium (3 to 4 wt %). It is likely that the ``root`` cause of this agglomerate originated in the dense phase of the FBC bed. Because fluidized bed combustors work below the ash fusion temperature of coal ash, aluminosilicates (clays) in the ash probably became ``sticky`` due to fluxing reactions with pyrite (FeS{sub 2}) and perhaps alkalies (Na). This is indicated by the high amounts of iron, silica, and alumina in the agglomerate. Because of the size of the deposit, the bed particles probably agglomerated in the dust collector.

Brown, R.C.; Dawson, M.R.; Smeenk, J.L.

1994-01-01T23:59:59.000Z

258

Ingestion Pathway Consequences of an H-Separations Coil and Tube Failure  

SciTech Connect

The food ingestion consequences of an accidental release, scenario 1-RD-2.35, are evaluated for H-Separations. The sizes of land areas requiring the protective action of food interdiction are calculated. The consequences of the release are evaluated with the HOTSPOT model and an EXCEL spreadsheet.

Blanchard, A.

1999-08-04T23:59:59.000Z

259

E-Print Network 3.0 - abundance bed net Sample Search Results  

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

s00723-007-0002-7 Summary: Applied Magnetic Resonance Noninvasive Measurements of Gas Exchange in a Three- Dimensional Fluidized Bed... -fluidized bed of solid par- ticles....

260

E-Print Network 3.0 - agitated fluidized bed Sample Search Results  

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

testing of manure digestion system has been initiated. The new TAMU fluidized bed gasifier... of the fluidized bed gasifier. Activity this quarter: a. The assembly of the new...

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

E-Print Network 3.0 - agitation fluidized bed Sample Search Results  

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

testing of manure digestion system has been initiated. The new TAMU fluidized bed gasifier... of the fluidized bed gasifier. Activity this quarter: a. The assembly of the new...

262

E-Print Network 3.0 - annual fluidized bed Sample Search Results  

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

University of Minnesota Collection: Engineering 16 POTENTIAL ADVANTAGES OF INCINERATION IN FLUIDIZED BEDS Summary: POTENTIAL ADVANTAGES OF INCINERATION IN FLUIDIZED BEDS...

263

CARBON BED MERCURY EMISSIONS CONTROL FOR MIXED WASTE TREATMENT  

SciTech Connect

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

264

Neural Network Based Montioring and Control of Fluidized Bed.  

SciTech Connect

The goal of this project was to develop chaos analysis and neural network-based modeling techniques and apply them to the pressure-drop data obtained from the Fluid Bed Combustion (FBC) system (a small scale prototype model) located at the Federal Energy Technology Center (FETC)-Morgantown. The second goal was to develop neural network-based chaos control techniques and provide a suggestive prototype for possible real-time application to the FBC system. The experimental pressure data were collected from a cold FBC experimental set-up at the Morgantown Center. We have performed several analysis on these data in order to unveil their dynamical and chaotic characteristics. The phase-space attractors were constructed from the one dimensional time series data, using the time-delay embedding method, for both normal and abnormal conditions. Several identifying parameters were also computed from these attractors such as the correlation dimension, the Kolmogorov entropy, and the Lyapunov exponents. These chaotic attractor parameters can be used to discriminate between the normal and abnormal operating conditions of the FBC system. It was found that, the abnormal data has higher correlation dimension, larger Kolmogorov entropy and larger positive Lyapunov exponents as compared to the normal data. Chaotic system control using neural network based techniques were also investigated and compared to conventional chaotic system control techniques. Both types of chaotic system control techniques were applied to some typical chaotic systems such as the logistic, the Henon, and the Lorenz systems. A prototype model for real-time implementation of these techniques has been suggested to control the FBC system. These models can be implemented for real-time control in a next phase of the project after obtaining further measurements from the experimental model. After testing the control algorithms developed for the FBC model, the next step is to implement them on hardware and link them to the experimental system. In this report, the hardware implementation issues of the control algorithms are also discussed.

Bodruzzaman, M.; Essawy, M.A.

1996-04-01T23:59:59.000Z

265

Tax consequences of separating corporate businesses  

E-Print Network (OSTI)

Lips ARY g ~ggpgF ep &Ex' TAX CONSEQUENCES OP SEPARATING CORPORATE BUSINESSES A Thesis Gordon D. Zuber Submitted to the Graduate School of the Agricultural and lNechanical College of Texas in partial fulfillment of the requirements... for the Degree of MASTER OP BUSINESS ADl/iliVISTRAT ION August 1958 Ma)or Subject: Accounting TAX CONSEQUENCES OP SEPARATING CORPORATE BUSINESSES A Thesis Gordon D. Zuber Approved as to style and content by: Chairman of the Committee ead. o the Divas...

Zuber, Gordon Dewey

2012-06-07T23:59:59.000Z

266

Pebble-bed pebble motion: Simulation and Applications  

SciTech Connect

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

267

THE SCALE-UP OF LARGE PRESSURIZED FLUIDIZED BEDS FOR ADVANCED COAL FIRED PROCESSES  

SciTech Connect

Pressurized fluidization is a promising new technology for the clean and efficient combustion of coal. Its principle is to operate a coal combustor at high inlet gas velocity to increase the flow of reactants, at an elevated pressure to raise the overall efficiency of the process. Unfortunately, commercialization of large pressurized fluidized beds is inhibited by uncertainties in scaling up units from the current pilot plant levels. In this context, our objective is to conduct a study of the fluid dynamics and solid capture of a large pressurized coal-fired unit. The idea is to employ dimensional similitude to simulate in a cold laboratory model the flow in a Pressurized Circulating Fluid Bed ''Pyrolyzer,'' which is part of a High Performance Power System (HIPPS) developed by Foster Wheeler Development Corporation (FWDC) under the DOE's Combustion 2000 program.

Leon Glicksman; Hesham Younis; Richard Hing-Fung Tan; Michel Louge; Elizabeth Griffith; Vincent Bricout

1998-04-30T23:59:59.000Z

268

Molecular Chemistry of Consequence to Renewable Energy  

Science Journals Connector (OSTI)

Molecular Chemistry of Consequence to Renewable Energy ... The construction of energy conversion cycles aimed at driving unfavorable, small-molecule activation reactions with solar photons confront daunting challenges because they rely on chemical transformations not understood at the most basic levels. ...

Jillian L. Dempsey; Arthur J. Esswein; David R. Manke; Joel Rosenthal; Jake D. Soper; Daniel G. Nocera

2005-09-26T23:59:59.000Z

269

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

270

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

271

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

272

Fluidized bed pyrolysis of terrestrial biomass feedstocks  

SciTech Connect

Hybrid poplar, switchgrass, and corn stover were pyrolyzed in a bench scale fluidized-bed reactor to examine the influence of storage time on thermochemical converting of these materials. The influence of storage on the thermochemical conversion of the biomass feedstocks was assessed based on pyrolysis product yields and chemical and instrumental analyses of the pyrolysis products. Although char and gas yields from corn stover feedstock were influenced by storage time, hybrid poplar and switchgrass were not significantly affected. Liquid, char, and gas yields were feedstock dependent. Total liquid yields (organic+water) varied from 58%-73% depending on the feedstock. Char yields varied from 14%-19% while gas yields ranged from 11%-15%. The chemical composition of the pyrolysis oils from hybrid polar feedstock was slightly changed by storage, however, corn stover and switchgrass feedstock showed no significant changes. Additionally, stored corn stover and hybrid poplar pyrolysis oils showed a significant decrease in their higher heating values compared to the fresh material.

Besler, S.; Agblevor, F.A.; Davis, M.F. [National Renewable Energy Lab., Golden, CO (United States)] [and others

1994-12-31T23:59:59.000Z

273

The fluid bed market: Status, trends, & outlook  

SciTech Connect

Fluidized bed combustion (FBC) technology has become a major commercial competitor for conventional solid fuel combustion systems. Since the mid-1980s, independent power producers (IPPs) and cogenerators in particular, pursuing opportunities created by PURPA, have led the way in deploying FBC boilers for electric power and cogeneration plants in the United States. Circulating FBC (CFBC) boilers became the predominant FBC choice for coal-, coke-, and coal waste-fired projects with unit capacities typically in the range of 300,000-600,000 lb/hr (35-70 MW (nominal)). Utility-type reheat units in the 115-165 MW (net) range are now in operation in the United States and Europe. A 250 MW CFBC unit is under construction for 1995 startup in France, and another is scheduled for 1998 startup in Pennsylvania. A 350 MW bubbling FBC boiler is being commissioned now in Japan. Several other CFBC projects that would employ 150-250 MW CFBC units are in various stages of planning in the United States, Puerto Rico, Europe, and Asia.

Simbeck, D.R.; Johnson, H.E.; Wilhelm, D.J. [SFA Pacific, Inc., Mountain View, CA (United States)

1994-12-31T23:59:59.000Z

274

Dynamic analysis of a circulating fluidized bed riser  

SciTech Connect

A linear state model is proposed to analyze dynamic behavior of a circulating fluidized bed riser. Different operating regimes were attained with high density polyethylene beads at low and high system inventories. The riser was operated between the classical choking velocity and the upper transport velocity demarcating fast fluidized and transport regimes. At a given riser superficial gas velocity, the aerations fed at the standpipe were modulated resulting in a sinusoidal solids circulation rate that goes into the riser via L-valve. The state model was derived based on the mass balance equation in the riser. It treats the average solids fraction across the entire riser as a state variable. The total riser pressure drop was modeled using Newton’s second law of motion. The momentum balance equation involves contribution from the weight of solids and the wall friction caused by the solids to the riser pressure drop. The weight of solids utilizes the state variable and hence, the riser inventory could be easily calculated. The modeling problem boils down to estimating two parameters including solids friction coefficient and time constant of the riser. It has been shown that the wall friction force acts in the upward direction in fast fluidized regime which indicates that the solids were moving downwards on the average with respect to the riser wall. In transport regimes, the friction acts in the opposite direction. This behavior was quantified based on a sign of Fanning friction factor in the momentum balance equation. The time constant of the riser appears to be much higher in fast fluidized regime than in transport conditions.

Panday, Rupen [REM Engineering PLLC; Shadle, Lawrence J. [U.S. DOE; Guenther, Chris [U.S. DOE

2012-01-01T23:59:59.000Z

275

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

276

Computational Analysis of Fluid Flow in Pebble Bed Modular Reactor  

E-Print Network (OSTI)

High Temperature Gas-cooled Reactor (HTGR) is a Generation IV reactor under consideration by Department of Energy and in the nuclear industry. There are two categories of HTGRs, namely, Pebble Bed Modular Reactor (PBMR) and Prismatic reactor. Pebble...

Gandhir, Akshay

2012-10-19T23:59:59.000Z

277

Initial Design of a Dual Fluidized Bed Reactor  

E-Print Network (OSTI)

from a steam hydro gasification and reforming process.study on biomass Air-steam gasification in a fluidized bed.limestone calcination on the gasification processes in a BFB

Yun, Minyoung

2014-01-01T23:59:59.000Z

278

EEB Hub: A Test Bed for Nationwide Energy Efficiency  

E-Print Network (OSTI)

EEB Hub: A Test Bed for Nationwide Energy Efficiency Wednesday, May 1, 2013 11:00 a.m. - 12:00 p 2011, became the executive director of the Energy Efficient Buildings (EEB) HUB through the US

Hall, Sharon J.

279

Design and Operation of CFB Boilers with Low Bed Inventory  

Science Journals Connector (OSTI)

In this paper, the challenges and problems of the circulating fluidized bed (CFB) combustion technology are summarized and analyzed. In order to resolve the problems in CFB boiler application, design principals a...

Jun Su; Xiaoxing Zhao; Jianchun Zhang…

2010-01-01T23:59:59.000Z

280

Initial Design of a Dual Fluidized Bed Reactor  

E-Print Network (OSTI)

fluidized bed gaisifers (CFB) (Figure 1.6) 1.3.1. Bubblingbed gasifiers (BFB and CFB) have great features for SH.employed for the SHR design. CFB enables a circulation of

Yun, Minyoung

2014-01-01T23:59:59.000Z

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.


281

Fluid Beds: At Last, Challenging Two Entrenched Practices  

Science Journals Connector (OSTI)

...FLUIDIZED-BED COMBUSTOR, JOURNAL...FLUIDIZED COAL COMBUSTOR, COMBUSTION...NONCATALYTIC GAS-SOLID REACTIONS...PARTICLES AT HIGH VELOCITIES...SATIJA, S, PRESSURE-FLUCTUATIONS...gasoline has a higher octane number...to convert natural gas to gasoline...

Arthur M. Squires; Mooson Kwauk; Amos A. Avidan

1985-12-20T23:59:59.000Z

282

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

283

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 ..................................................................................14 Ability of the Consortium to Produce Methane from Coal and Metabolites ................16.............................................................................................21 Coal and Methane Production

Maxwell, Bruce D.

284

Spectral Analysis of Thinning Beds Using Ground Penetrating Radar  

E-Print Network (OSTI)

to image internal dune structures. The results showed anomalous features at merging beds and contacts between interfaces. The results directly influence sedimentological and geomorphological interpretations of internal dune structure and can be used...

Francese, Renee Rose

2012-07-16T23:59:59.000Z

285

Simulation of biomass gasification in a dual fluidized bed gasifier  

Science Journals Connector (OSTI)

Biomass gasification with steam in a dual-fluidized bed gasifier (DFBG) was simulated with ASPEN Plus. ... that the content of char transferred from the gasifier to the combustor decreases from 22.5...2 concentra...

Jie He; Kristina Göransson; Ulf Söderlind…

2012-03-01T23:59:59.000Z

286

Fluidized Bed Technology- An R&D Success Story  

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

In the early 1990s, POWER magazine called the development of fluidized bed coal combustors "the commercial success story of the last decade in the power generation business." The success, perhaps...

287

MODULAR PEBBLE BED REACTOR PROJECT UNIVERSITY RESEARCH CONSORTIUM  

E-Print Network (OSTI)

Annual Report Page ii MODULAR PEBBLE BED REACTOR ABSTRACT This project is developing a fundamental. Publication of an archival journal article covering this work is being prepared. · Detailed gas reactor Abstract

288

Tempestites in a teapot? Condensation-generated shell beds in the Upper Ordovician, Cincinnati Arch, USA  

Science Journals Connector (OSTI)

Skeletal concentrations in mudstones may represent local facies produced by storm winnowing in shallow water, or time-specific deposits related to intervals of diminished sediment supply. Upper Ordovician (Katian) of the Cincinnati region is a mixed siliciclastic-carbonate succession including meter-scale cycles containing a shelly limestone-dominated phase and a mudstone-dominated phase. The “tempestite proximality model” asserts that shell-rich intervals originated by winnowing of mud from undifferentiated fair-weather deposits. Thus shell beds are construed as tempestites, while interbedded mudstones represent either fair-weather or bypassed mud. Meter-scale cycles are attributed to sea-level fluctuation or varying storm intensity. Alternatively, the “episodic starvation model” argues, on the basis of petrographic, taphonomic, and stratigraphic evidence, that, despite widespread evidence for storms or other turbulence events (e.g. tsunamis), winnowing alone could not generate shell beds where none had previously existed. Instead, variations in sediment supply are construed as the principal cause of shelly-mudstone cycles. Shell-rich deposits accrue during periods of siliciclastic sediment starvation and relatively shell-free mud accumulates during periods of sediment influx. Tempestite proximality and episodic starvation models lead to contrasting predictions about proximal-to-distal facies patterns. These are: (i) large versus small volumes of distally-deposited, bypassed mud; (ii) proximal grainstones and distal packstones versus distal grainstones and proximal packstones; and (iii) proximal versus distal amalgamation and condensation of shell beds. In this paper, these predictions are tested by (i) comparing meter-scale cycles from different horizons and depositional environments through the lower Cincinnatian succession (Kope through McMillan Formations representing deep subtidal through intertidal environments), and (ii) correlating intervals and individual meter-scale cycles from the Fairview Formation of the Cincinnati Arch (shallow subtidal) north and west into the Maquoketa Shale (deep subtidal) in subsurface of Ohio and Indiana. Both approaches show patterns consistent with episodic starvation, not winnowing, including: (i) small differences in stratigraphic thickness indicate small volumes of bypassed mud; (ii) discrete distal deep-water grainstones that splay proximally into bundles of thinner shallow-water packstones alternating with shelly muds show that grainstones formed from a lack of, rather than removal of mud; and (iii) distal shell?bed amalgamation and condensation (and corresponding proximal splaying) of shell beds shows a proximal source of mud. Thus, winnowing by storms or other turbulence events did not generate shell beds or cycles from undifferentiated sediments despite abundant evidence for storm deposition. High-resolution correlations imply that the shell-bed and mud-bed hemicycles reflect simultaneous basin-wide changes in sedimentary style rather than contemporaneous facies belts that track sea level. In this sense, shell-rich and mud-rich hemicycles are “non-Waltherian” facies.

Benjamin F. Dattilo; Carlton E. Brett; Thomas J. Schramm

2012-01-01T23:59:59.000Z

289

Experimental investigation into the incineration of wool scouring sludges in a novel rotating fluidised bed  

Science Journals Connector (OSTI)

The main purpose of this research was to investigate the possibility of incineration of wool scouring sludges in a novel vertical axis rotating fluidised bed (RFB). A small-scale RFB was designed and constructed with an internal diameter (ID) of 200 mm and height of 50 mm to carry out the experiments. In phase one of the experiments, a cold test was conducted to investigate the fluidisation performance of the RFB, which eventually led to the optimisation of the operating parameters, i.e., sand particle size, rotation speed and bed loading (bed thickness) which ensures complete fluidisation and minimum particle elutriation. Sand particle size of 0.5 to 0.6 mm, rotation speed of 200 to 400 rpm and bed loading of 1 kg (equivalent to bed thickness of 27 mm) were found optimal. These information generated were useful for the second phase of the experiments, which was the hot test, in investigating the possibility of incinerating wool scouring sludges in the RFB. Nine wool sludges from different process routes generated from the wool scouring industries were analysed for their compositions. Most of these sludges were highly moist, had high volatile matter and high ash content with low level of fixed carbon. These characteristics made incineration difficult. Hence, the effect of varying the moisture content, rotation speed and sludge feed rate on the incineration of the three selected sludges were studied in the hot test. With 5% support methane, all sludges with a maximum moisture up to 70% as-received could be successfully burned in the RFB at rotating speeds of 200 and 300 rpm. The combustion was found to be intense with a high efficiency due to the good turbulence and mixing in the RFB. The combustion gases produced, i.e., CO, CO2 and \\{NOx\\} were reasonably low due to the high combustion intensity and efficiency. To study the dynamics of the bed and freeboard region in the RFB, the velocity flow field was simulated using a computational fluid dynamics (CFD) model to generate information of the flow pattern. The special advantages of swirling flow would benefit the gas combustion in the RFB. The experimental results obtained have suggested that the incineration was successful and the ash particles elutriated were fine due to the good mixing and turbulence in the RFB. This also reflects the RFB as an effective incinerator.

W.Y Wong; Y Lu; V.S Nasserzadeh; J Swithenbank; T Shaw; M Madden

2000-01-01T23:59:59.000Z

290

Research paper Early diagenetic carbonate bed formation at the sedimentwater interface triggered  

E-Print Network (OSTI)

, chemical, and C and O stable isotope data allow us to infer that the beds formed during synsedimentary exhibit two or three carbonate beds in the vicinity of Wimereux city (3 beds at Wimereux-North and 2 beds Formation, Wheatleyensis+Pectinatus ammonite zones, see below) represents a low-energy shelf facies

291

Performance characterization of a packed bed electro-filter  

E-Print Network (OSTI)

PERFORMANCE CHARACTERIZATION OF A PACKED BED ELECTRO-FILTER A Thesis by A JAY NARAYANAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... December 1990 Major Subject: Safety Engineering PERFORMANCE CHARACTERIZATION OF A PACKED BED ELECTRO-FILTER A Thesis by AJAY NARAYANAN Approved as to style and content by: John P. Wagn (Ch ' of the Com ittee) Aydin Akgerman (Member) Ri ard B...

Narayanan, Ajay

2012-06-07T23:59:59.000Z

292

On-Site Wastewater Treatment Systems: Evapotranspiration Bed  

E-Print Network (OSTI)

Two-compartment septic tank Loam soil Crushed stone Evapotranspiration bed Wick On-site wastewater treatment systems Evapotranspiration bed Bruce Lesikar Extension Agricultural Engineering Specialist The Texas A&M University System ET systems..., synthetic or concrete liner. A liner is required if the surrounding soil is very permeable, such as in sandy gravel or karst limestone. Unlined systems can be used in highly impermeable soils such as heavy clays. In unlined systems, wastewater is disposed...

Lesikar, Bruce J.

1999-09-01T23:59:59.000Z

293

Kinetic parameter estimation using nonisothermal trickle-bed reactor data  

E-Print Network (OSTI)

KINETIC PARAMETER ESTIMATION USING NONISOTHERMAL TRICKLE-BED REACTOR DATA A Thesis by MICHAEL ALLEN MENSIK Submitted to the Graduate College of Texas ALM University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1985 Major Subject: Chemical Engineering KINETIC PARAMETER ESTIMATION USING NONISOTHERMAL TRICKLE-BED REACTOR DATA A Thesis by MICHAEL ALLEN MENSIK Approved as to style and content by: A. ger n (Chairman of Comm ee) R. G. Antho...

Mensik, Michael Allen

2012-06-07T23:59:59.000Z

294

Fluidized-bed retrofit a practical alternative to FGD  

SciTech Connect

A comparison is made between the costs of flue-gas desulphurization retrofit to a 112 MW pf-fired boiler, fluidized-bed combustion retrofit to the boiler, and a new fluidized-bed boiler. Breakdowns are given for capital costs, operating and maintenance costs and the busbar cost of energy for a 20 year unit life. The analysis shows that fbc is a viable option for the retrofit of many existing boilers from both a technical and economic viewpoint.

Stringfellow, T.E.

1984-02-01T23:59:59.000Z

295

NNSA Releases Pictures, Video of Consequence Management Response...  

Office of Environmental Management (EM)

Releases Pictures, Video of Consequence Management Response Teams Deploying to Japan NNSA Releases Pictures, Video of Consequence Management Response Teams Deploying to Japan March...

296

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

297

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

298

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

299

Moving Bed, Granular Bed Filter Development Program: Option 1, Component Test Facility. Task 3, Test plan  

SciTech Connect

In the base contract, Combustion Power Co. developed commercial designs for a moving granular-bed filter (GBF). The proposed filter is similar to previous designs in terms of its shape and method of filtration. The commercial designs have scaled the filter from a 5 ft diameter to as large as a 20 ft diameter filter. In Task 2 of the Moving Bed-Granular Filter Development Program, all technical concerns related to the further development of the filter are identified. These issues are discussed in a Topical Report which has been issued as part of Task 2. Nineteen issues are identified in this report. Along with a discussion of these issues are the planned approaches for resolving each of these issues. These issues will be resolved in either a cold flow component test facility or in pilot scale testing at DOE`s Power System Development Facility (PSDF) located at Southem Company Services` Wilsonville facility. Task 3 presents a test plan for resolving those issues which can be addressed in component test facilities. The issues identified in Task 2 which will be addressed in the component test facilities are: GBF scale-up; effect of filter cone angle and sidewall materials on medium flow and ash segregation; maximum gas filtration rate; lift pipe wear; GBF media issues; mechanical design of the gas inlet duct; and filter pressure drop. This document describes a test program to address these issues, with testing to be performed at Combustion Power Company`s facility in Belmont, California.

Haas, J.C.; Purdhomme, J.W.; Wilson, K.B.

1994-04-01T23:59:59.000Z

300

FLUIDIZED BED STEAM REFORMER MONOLITH FORMATION  

SciTech Connect

Fluidized Bed Steam Reforming (FBSR) is being considered as an alternative technology for the immobilization of a wide variety of aqueous high sodium containing radioactive wastes at various DOE facilities in the United States. The addition of clay, charcoal, and a catalyst as co-reactants converts aqueous Low Activity Wastes (LAW) to a granular or ''mineralized'' waste form while converting organic components to CO{sub 2} and steam, and nitrate/nitrite components, if any, to N{sub 2}. The waste form produced is a multiphase mineral assemblage of Na-Al-Si (NAS) feldspathoid minerals with cage-like structures that atomically bond radionuclides like Tc-99 and anions such as SO{sub 4}, I, F, and Cl. The granular product has been shown to be as durable as LAW glass. Shallow land burial requires that the mineralized waste form be able to sustain the weight of soil overburden and potential intrusion by future generations. The strength requirement necessitates binding the granular product into a monolith. FBSR mineral products were formulated into a variety of monoliths including various cements, Ceramicrete, and hydroceramics. All but one of the nine monoliths tested met the <2g/m{sup 2} durability specification for Na and Re (simulant for Tc-99) when tested using the Product Consistency Test (PCT; ASTM C1285). Of the nine monoliths tested the cements produced with 80-87 wt% FBSR product, the Ceramicrete, and the hydroceramic produced with 83.3 wt% FBSR product, met the compressive strength and durability requirements for an LAW waste form.

Jantzen, C

2006-12-22T23:59:59.000Z

Note: This page contains sample records for the topic "bed consequence modeling" from the National Library of EnergyBeta (NLEBeta).
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301

The fluidized bed combustion ash management puzzle  

SciTech Connect

As the electric and industrial power generation industry upgrades and expands, the amount of coal and other solid fuels also expands. With increased environmental controls, the introduction of a competitive market for power, and the increased interest in opportunity fuels will increase the usage of Fluidized Bed Combustion (FBC) boilers in the power industry. The combustion of these solid fuels will generate combustion ashes. Power generators, including FBC boilers owners, have traditionally looked to landfills for the disposal of their ash. With the tighter environmental controls being placed on landfills at the federal and state level, power generators are beginning to see constantly escalating tipping fees which now make the landfill option less attractive. In some instances, landfills are beginning to refuse to accept ash regardless of the tipping fee. In view of this, the power generators are now struggling to find a place to store or dispose of the ash that is produced by their power boiler. Other disposal alternatives such as backhaul to the mine and beneficial reuse are now being considered. Either alternative presents its own set of technical and environmental variables to be considered in developing an effective ash management plan. To be effective, these plans need to incorporate an aggressive, yet realistic, role to support beneficial reuse of the ash. Many applications exist for reuse of the various types of ash. The applications for conventional ashes such as those from pulverized coal boilers and stoker fired boilers are mature and more commonplace. The uses for FBC ash are not as well researched and demonstrated and therefore the marketing opportunities for FBC ash continue to require development. FBC boiler owners and operators must be willing to accept the challenges posed in developing these reuse applications for FBC ash for the market to accept the applications for FBC ash and allow the full value of the FBC ash to be realized.

Fitzgerald, H.B. [ReUse Technology, Inc., Kennesaw, GA (United States)

1996-12-31T23:59:59.000Z

302

Influence of mean gas residence time in the bubbling fluidised bed on the performance of a 100-kW dual fluidised bed steam gasifier  

Science Journals Connector (OSTI)

In this study, the influence of mean gas residence time in the bubbling fluidised bed, ? f..., on the performance of a pilot scale 100 kW dual fluidised bed gasifier was experimentally investigate...

W. L. Saw; S. S. Pang

2012-09-01T23:59:59.000Z

303

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

SciTech Connect

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

304

Advanced Core Design And Fuel Management For Pebble-Bed Reactors  

SciTech Connect

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

305

Observable consequences of Langmuir turbulence in active galactic nuclei  

SciTech Connect

The authors discuss in detail the observable consequences of non-linear microscopic plasma processes in active galactic nuclei. The combination of several elementary momentum gain (shock acceleration and stochastic acceleration) and loss processes (synchroton radiation, inverse Compton scattering) produces an almost monoenergetic distribution function of relativistic electrons - the pile-up - which excites Langmuir waves. Turbulent wave-wave and wave-particle interactions lead to nonlinear stabilization of the pile-up. The temporal and spatial evolution of the Langmuir waves and the relativistic electrons determine the shape and time scale of the spectral variations. The model is applied to extragalactic nuclei and to the galactic center as well.

Lesch, H.

1989-04-01T23:59:59.000Z

306

Induction log responses to layered, dipping, and anisotropic formations: Induction log shoulder-bed corrections to anisotropic formations and the effect of shale anisotropy in thinly laminated sand/shale sequences  

SciTech Connect

Induction log responses to layered, dipping, and anisotropic formations are examined analytically. The analytical model is especially helpful in understanding induction log responses to thinly laminated binary formations, such as sand/shale sequences, that exhibit macroscopically anisotropic: resistivity. Two applications of the analytical model are discussed. In one application we examine special induction log shoulder-bed corrections for use when thin anisotropic beds are encountered. It is known that thinly laminated sand/shale sequences act as macroscopically anisotropic: formations. Hydrocarbon-bearing formations also act as macroscopically anisotropic formations when they consist of alternating layers of different grain-size distributions. When such formations are thick, induction logs accurately read the macroscopic conductivity, from which the hydrocarbon saturation in the formations can be computed. When the laminated formations are not thick, proper shoulder-bed corrections (or thin-bed corrections) should be applied to obtain the true macroscopic formation conductivity and to estimate the hydrocarbon saturation more accurately. The analytical model is used to calculate the thin-bed effect and to evaluate the shoulder-bed corrections. We will show that the formation resistivity and hence the hydrocarbon saturation are greatly overestimated when the anisotropy effect is not accounted for and conventional shoulder-bed corrections are applied to the log responses from such laminated formations.

Hagiwara, Teruhiko

1996-12-31T23:59:59.000Z

307

Thirty-Day Readmissions — Truth and Consequences  

Science Journals Connector (OSTI)

...patients are not readmitted as many as 4 weeks after discharge — events that are largely outside the hospitals' control. But the most important consequence of this policy is the improvements in quality and safety that hospitals will forgo, and those will be far more difficult to measure. Under the Affordable Care Act, hospitals with “worse than expected” 30-day readmission rates will be penalized by Medicare. But though a focus on readmissions may have good face validity, the policy attention to 30-day readmissions may be misguided.

Joynt K.E.; Jha A.K.

2012-04-12T23:59:59.000Z

308

Waveinduced velocities inside a model seagrass bed Mitul Luhar,1  

E-Print Network (OSTI)

. By damping nearbed water velocities, seagrasses reduce local resuspension and promote the retention the seabed. Reduced resuspension improves water clarity, leading to greater light penetration and increased

Nepf, Heidi M.

309

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

310

LIQUID-FLUIDIZED-BED HEAT' EXCHANGER FLOW DISTRIBUTION MODELS  

Office of Scientific and Technical Information (OSTI)

and vert- ical assemblies were developed. Recommendations f o r further develop- mental work are made. i i i CONTENTS ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . ....

311

Materials performance in fluidized-bed air heaters  

SciTech Connect

Development of cogeneration systems that involve combustion of coal in a fluidized bed and use of air heaters to generate hot air for turbine systems has been in progress for a number of years. The US Department of Energy (DOE) sponsored the Atmospheric Fluidized-Bed Cogeneration Air Heater Experiment (ACAHE) to assess the performance of various heat exchanger materials and establish confidence in the resultant designs of fluidized-bed-combustion air heater systems. Westinghouse Electric Corporation, in association with Babcock & Wilcox, Foster Wheeler, and ABB/Combustion Engineering, prepared specifications and hardware for the ACAHE. Argonne National Laboratory, through a contract with the Rocketdyne Division of Rockwell International, conducted tests in the DOE 1.8 {times} 1.8 m atmospheric fluidized-bed combustion facility in El Segundo, California. This paper presents an assessment of the materials performance in fluidized bed environments and examines guidelines for materials selection on the basis of corrosion resistance in air and in combustion environments, mechanical properties, fabricability/thermal stability, and cost.

Natesan, K.; Podolski, W.

1991-12-01T23:59:59.000Z

312

Materials performance in fluidized-bed air heaters  

SciTech Connect

Development of cogeneration systems that involve combustion of coal in a fluidized bed and use of air heaters to generate hot air for turbine systems has been in progress for a number of years. The US Department of Energy (DOE) sponsored the Atmospheric Fluidized-Bed Cogeneration Air Heater Experiment (ACAHE) to assess the performance of various heat exchanger materials and establish confidence in the resultant designs of fluidized-bed-combustion air heater systems. Westinghouse Electric Corporation, in association with Babcock Wilcox, Foster Wheeler, and ABB/Combustion Engineering, prepared specifications and hardware for the ACAHE. Argonne National Laboratory, through a contract with the Rocketdyne Division of Rockwell International, conducted tests in the DOE 1.8 {times} 1.8 m atmospheric fluidized-bed combustion facility in El Segundo, California. This paper presents an assessment of the materials performance in fluidized bed environments and examines guidelines for materials selection on the basis of corrosion resistance in air and in combustion environments, mechanical properties, fabricability/thermal stability, and cost.

Natesan, K.; Podolski, W.

1991-12-01T23:59:59.000Z

313

Six years of ABB-CE, petcoke and fluid beds  

SciTech Connect

Combustion Engineering, Inc. (ABB-CE) has constructed twenty circulating fluidized bed (CFB) boilers and 2 bubbling fluidized bed (BFB) boilers throughout North America. The units were designed to fire a wide range of fuels from anthracite culm to coals, lignites and biomasses. Based on fuels economics, some plants have decided to use petroleum coke as a replacement or supplemental fuel. The fluid bed boiler can inherently handle a wide range of fuel types without requiring modification or down-rating. ABB-CE units have a significant amount of petroleum coke operating experience firing 100% petroleum coke with no supplemental fuel ranging from the first commercial CFB unit at New Brunswick Power to the largest CFB unit at Texas New Mexico Power. Petroleum coke is also being co-fired with anthracite culm at the Scott Paper CFB. The world`s largest operating BFB, the 160 MWe unit at TVA`s Shawnee plant, has also been co-firing petroleum coke. The ability of the fluidized bed technology to fire low volatile fuels such as petroleum cokes, efficiently and in an environmentally acceptable manner will result in the use of this technology as a preferred means of power generation. This report gives a brief description of the petroleum coke firing experiences with ABB-CE fluid bed steam generators over the last six years.

Tanca, M.

1994-12-31T23:59:59.000Z

314

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

315

Enhanced dispersion in cylindrical packed beds  

Science Journals Connector (OSTI)

...method dispersivity geometry ground water heterogeneity hydrodynamics numerical models pollution pore water porosity remediation simulation tracers 2001 07...processes including groundwater remediation, secondary oil recovery...

2002-01-01T23:59:59.000Z

316

Coal hydrogenation and deashing in ebullated bed catalytic reactor  

DOE Patents (OSTI)

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

317

Decontamination of combustion gases in fluidized bed incinerators  

DOE Patents (OSTI)

Sulfur-containing atmospheric pollutants are effectively removed from exit gas streams produced in a fluidized bed combustion system by providing a fluidized bed of particulate material, i.e. limestone and/or dolomite wherein a concentration gradient is maintained in the vertical direction. Countercurrent contacting between upwardly directed sulfur containing combustion gases and descending sorbent particulate material creates a concentration gradient across the vertical extent of the bed characterized in progressively decreasing concentration of sulfur, sulfur dioxide and like contaminants upwardly and decreasing concentration of e.g. calcium oxide, downwardly. In this manner, gases having progressively decreasing sulfur contents contact correspondingly atmospheres having progressively increasing concentrations of calcium oxide thus assuring optimum sulfur removal.

Leon, Albert M. (Mamaroneck, NY)

1982-01-01T23:59:59.000Z

318

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)

319

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

SciTech Connect

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

320

Potential health impacts of burning coal beds and waste banks  

Science Journals Connector (OSTI)

Uncontrolled release of pollutants from burning coal beds and waste banks presents potential environmental and human health hazards. On a global scale, the emissions of large volumes of greenhouse gases from burning coal beds may contribute to climate change that alters ecosystems and patterns of disease occurrence. On regional and local scales, the emissions from burning coal beds and waste banks of acidic gases, particulates, organic compounds, and trace elements can contribute to a range of respiratory and other human health problems. Although there are few published reports of health problems caused by these emissions, the potential for problems can be significant. In India, large numbers of people have been displaced from their homes because of health problems caused by emissions from burning coal beds. Volatile elements such as arsenic, fluorine, mercury, and selenium are commonly enriched in coal deposits. Burning coal beds can volatilize these elements, which then can be inhaled, or adsorbed on crops and foods, taken up by livestock or bioaccumulated in birds and fish. Some of these elements can condense on dust particles that can be inhaled or ingested. In addition, selenium, arsenic, lead, tin, bismuth, fluorine, and other elements condense where the hot gaseous emissions come in contact with ambient air, forming mats of concentrated efflorescent minerals on the surface of the ground. These mats can be leached by rainwater and washed into local water bodies providing other potential routes of exposure. Although there are little data linking burning coal beds and waste banks to known health problems, a possibly analogous situation exists in rural China where mineralized coal burned in a residential environment has caused widespread and severe health problems such as fluorosis and arseniasis.

Robert B Finkelman

2004-01-01T23:59:59.000Z

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.


321

Lateral solids dispersion coefficient in large-scale fluidized beds  

SciTech Connect

The design of fuel feed ports in a large-scale fluidized bed combustor depends on the fuel characteristics and lateral solids mixing. However, the reported values of the effective lateral solids dispersion coefficient (D{sub sr}) are scattered in the broad range of 0.0001-0.1 m{sup 2}/s. With the aim of predicting D{sub sr} in wider fluidized beds which is difficult to measure directly or deduce from experimental results in lab-scale facilities, a computational method is proposed. It combines the Eulerian-Granular simulation and fictitious particle tracing technique. The value of D{sub sr} is calculated based on the movement of the tracers. The effect on D{sub sr} of bed width (W) ranging from 0.4 m up to 12.8 m at different levels of superficial gas velocity (U{sub 0}) is investigated. It is found that increasing W whilst maintaining U{sub 0}, D{sub sr} initially increases markedly, then its increase rate declines, and finally it stays around a constant value. The computed values of D{sub sr} are examined quantitatively and compared with a thorough list of the measured D{sub sr} in the literature since 1980s. Agreed with the measurements performed in the pilot-scale fluidized beds, the value of D{sub sr} in wider facilities at higher fluidizing velocities is predicted to be around the order of magnitude of 0.1 m{sup 2}/s, much higher than that in lab-scale beds. Finally, the effect of D{sub sr} on the distribution of fuel particles over the cross section in fluidized beds with the specified layout of feed ports is discussed. (author)

Liu, Daoyin; Chen, Xiaoping [School of Energy and Environment, Southeast University, Nanjing 210096 (China)

2010-11-15T23:59:59.000Z

322

Application of Multivariable Model Predictive Advanced Control for a 2×310T/H CFB Boiler Unit  

Science Journals Connector (OSTI)

When a CFB boiler is in automatic control, there are ... non-linear combustion model, based on the CFB combustion characteristics of bed fuel inventory, heating values, bed lime inventory and consumption. CFB adv...

Zhao Weijie; Dai Zongllao; Gou Rong…

2010-01-01T23:59:59.000Z

323

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 ..............................................................................................................................................................................

324

Refractory experience in circulating fluidized bed combustors, Task 7  

SciTech Connect

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

325

Control of thermal processes in a fluidized bed combustor (FBC)  

SciTech Connect

Heat and mass balance equations for the transient process of a fluidized bed furnace are described. The equations involve heat release from char and volatiles combustion, heat consumption during moisture evaporation, and heating of char and circulating particles. Calculations and experimental data for steady-state and unsteady conditions are compared. The results show that the height of the dense bed, the excess-air ratio and kinetic features of the fuel affect the rate of the transient process. The time constant for a disturbance by a change of the air flow rate was found to be smaller than the one for a change of the fuel input.

Munts, V.A.; Filippovskij, N.F.; Baskakov, A.P.; Pavliok, E.J. [Ural State Technical Univ., Ekaterinburg (Russian Federation). Heat Power Dept.; Leckner, B. [Chalmers Univ. of Technology, Gothenburg (Sweden). Dept. of Energy Conversion

1997-12-31T23:59:59.000Z

326

Influence of partial wetting on trickle-bed reactor performance  

E-Print Network (OSTI)

was started once the hydrogen flow rate stabilized. The time required for 4he first drop to appear at the vapor/liquid separator ranged from ]0 ? 40 minutes, depending on the liquid flow rate. The liquid flow rate was measured by monitoring the liquid level..., conversion with we4t, ing efficiency . 23 25 Experiment, al apparatus 6. Cross sect, ion of experimental trickle-bed reactor 7. Approach to steady stale 8. Catalyst, bed axial temperature profiles Change in the exit conversion with liquid flow rate...

Ruecker, Craig Michael

2012-06-07T23:59:59.000Z

327

Effective thermal conductivity of packed beds of spheres  

E-Print Network (OSTI)

of N are known only for certain types of regular packing, however, an empirical relation for m ) 0. 3 is given as N = 11. 6(l ? m) (22) When a load is applied to a bed of spheres, the contact area between spheres is determined using the Hertz... the authors compared their analytical solutions to has consistently dealt with beds of materials which have a very low thermal conductivity compared to that of the brass and aluminum spheres. These materials have been solid and hollow glass spheres, ceramic...

Duncan, Allen Buchanan

1987-01-01T23:59:59.000Z

328

Mental health consequences of the Chernobyl disaster  

Science Journals Connector (OSTI)

The psychosocial consequences of disasters have been studied for more than 100 years. The most common mental health consequences are depression, anxiety, post-traumatic stress disorder, medically unexplained somatic symptoms, and stigma. The excess morbidity rate of psychiatric disorders in the first year after a disaster is in the order of 20%. Disasters involving radiation are particularly pernicious because the exposure is invisible and universally dreaded, and can pose a long-term threat to health. After the Chernobyl disaster, studies of clean-up workers (liquidators) and adults from contaminated areas found a two-fold increase in post-traumatic stress and other mood and anxiety disorders and significantly poorer subjective ratings of health. Among liquidators, the most important risk factor was severity of exposure. In general population samples, the major risk factor was perceived exposure to harmful levels of radiation. These findings are consistent with results from A-bomb survivors and populations studied after the Three Mile Island nuclear power plant accident. With regard to children, apart from findings from ecological studies that lack direct data on radiation or other teratologic exposures and local studies in Kiev, the epidemiologic evidence suggests that neither radiation exposure nor the stress of growing up in the shadow of the accident was associated with emotional disorders, cognitive dysfunction, or impaired academic performance. Thus, based on the studies of adults, the Chernobyl Forum concluded that mental health was the largest public health problem unleashed by the accident. Since mental health is a leading cause of disability, physical morbidity, and mortality, health monitoring after radiation accidents like Fukushima should include standard measures of well-being. Moreover, given the comorbidity of mental and physical health, the findings support the value of training non-psychiatrist physicians in recognizing and treating common mental health problems like depression in Fukushima patients.

Evelyn J Bromet

2012-01-01T23:59:59.000Z

329

A Study of Vertical Gas Jets in a Bubbling Fluidized Bed  

SciTech Connect

A detailed experimental study of a vertical gas jet impinging a fluidized bed of particles has been conducted with the help of Laser Doppler Velocimetry measurements. Mean and fluctuating velocity profiles of the two phases have been presented and analyzed for different fluidization states of the emulsion. The results of this work would be greatly helpful in understanding the complex two-phase mixing phenomenon that occurs in bubbling beds, such as in coal and biomass gasification, and also in building more fundamental gas-solid Eulerian/Lagrangian models which can be incorporated into existing CFD codes. Relevant simulations to supplement the experimental findings have also been conducted using the Department of Energyâ??s open source code MFIX. The goal of these simulations was two-fold. One was to check the two-dimensional nature of the experimental results. The other was an attempt to improve the existing dense phase Eulerian framework through validation with the experimental results. In particular the sensitivity of existing frictional models in predicting the flow was investigated. The simulation results provide insight on wall-bounded turbulent jets and the effect frictional models have on gas-solid bubbling flows. Additionally, some empirical minimum fluidization correlations were validated for non-spherical particles with the idea of extending the present study to non-spherical particles which are more common in industries.

Steven Ceccio; Jennifer Curtis

2011-01-18T23:59:59.000Z

330

Practical and Regulatory Challenges in Controlling Trace Element Inputs to Soils from Land Application of Fluidized Bed Combustion Residues  

Science Journals Connector (OSTI)

The 165 MWe circulating fluidized bed boiler at the Nova Scotia Power Inc. ( ... largest fluidized bed unit. Fluidized bed combustion (FBC) allows the burning of high sulphur (...in situ capture of S (removal of ...

M. Hope-Simpson; W. Richards

2003-01-01T23:59:59.000Z

331

JODY AZZOUNI. Tracking Reason: Proof, Consequence and Truth  

Science Journals Connector (OSTI)

......Reviews Jody Azzouni. Tracking Reason: Proof, Consequence and Truth Conrad Asmus * * School of Philosophy, Anthropology...gmail.com Jody Azzouni. Tracking Reason: Proof, Consequence and Truth . New York: Oxford University Press......

Conrad Asmus

2009-10-01T23:59:59.000Z

332

E-Print Network 3.0 - anomalously high bed Sample Search Results  

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

that alternates low-R oil-saturated sand beds and high... in thinly bedded formations Jordan G. Mimoun1 , Carlos Torres-Verdin2 , and William E. Preeg3 ABSTRACT We... have...

333

An adaptable, low cost test-bed for unmanned vehicle systems research.  

E-Print Network (OSTI)

?? An unmanned vehicle systems test-bed has been developed. The test-bed has been designed to accommodate hardware changes and various vehicle types and algorithms. The… (more)

Goppert, James M.

2011-01-01T23:59:59.000Z

334

E-Print Network 3.0 - airborne experimental test-bed Sample Search...  

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

experimental test-bed Search Powered by Explorit Topic List Advanced Search Sample search results for: airborne experimental test-bed Page: << < 1 2 3 4 5 > >> 1 National Airborne...

335

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...

336

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

337

E-Print Network 3.0 - arrester beds Sample Search Results  

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

5 > >> 1 Joint initiation in bedded clastic rocks David T. McConaughy1 Summary: arrest lines and at bed boundaries. The hackle marks converge on a location from which the joint......

338

The Agglomeration in the Fluidized Bed Boiler During the Co-Combustion of Biomass with Peat  

Science Journals Connector (OSTI)

The formation of bed material coatings during the co-combustion of peat and biomass is caused by iron, calcium, aluminum ... Thus the bed material agglomeration during peat and biomass co-combustion is due to the...

Ritva E. A. Heikkinen; Mika E. Virtanen…

1999-01-01T23:59:59.000Z

339

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

340

Characterization of a solar-powered fluidyne test bed  

Science Journals Connector (OSTI)

Abstract Liquid piston Stirling engines (sometimes termed “fluidyne” engines) have been studied extensively and applied in a variety of energy conversion applications. They are attractive for low capital costs and simplicity of construction. In addition, their operation as external combustion engines allows for flexibility in primary energy sources which is a distinct advantage when a low-cost or free source of heat can be paired with their minimal construction costs. Disadvantages of these devices include relatively low efficiency and low power density. A solar-powered fluidyne test bed was constructed and tested extensively. The test bed was composed of a fluidyne engine constructed from copper pipe and plastic tubing coupled with a Fresnel lens for concentrating solar energy. The test bed was instrumented with temperature, pressure, and position sensors. The concentrated solar energy from the Fresnel lens provided ample power to operate the test bed, and tests were run in a wide variety of conditions. Temperature, pressure, and volume phasing along with indicated work are presented and discussed for operation of the engine with no externally imposed load.

Jackson W. Mason; James W. Stevens

2014-01-01T23:59:59.000Z

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.


341

Contraction scour in compound channels with cohesive soil beds  

E-Print Network (OSTI)

Bridge scour, which is the removal of bed materials from near the bridge foundations, is observed to be the most predominant cause of bridge failures in the United States. Scour in cohesive soils is greatly different from scour in cohesionless soils...

Israel Devadason, Benjamin Praisy

2008-10-10T23:59:59.000Z

342

Contraction scour in compound channels with cohesive soil beds  

E-Print Network (OSTI)

Bridge scour, which is the removal of bed materials from near the bridge foundations, is observed to be the most predominant cause of bridge failures in the United States. Scour in cohesive soils is greatly different from scour in cohesionless soils...

Israel Devadason, Benjamin Praisy

2009-05-15T23:59:59.000Z

343

Modular Pebble Bed Reactor High Temperature Gas Reactor  

E-Print Network (OSTI)

Modular Pebble Bed Reactor High Temperature Gas Reactor Andrew C Kadak Massachusetts Institute For 1150 MW Combined Heat and Power Station Oil Refinery Hydrogen Production Desalinization Plant VHTR/Graphite Discrimination system Damaged Sphere ContainerGraphiteReturn FuelReturn Fresh Fuel Container Spent Fuel Tank #12

344

The Design and Tests in a Three Interconnected Fluidized Bed  

Science Journals Connector (OSTI)

Hydrogen production based on chemical looping combustion can obtain clean hydrogen with near zero emission of carbon dioxide. This technique can be auto-thermal, making it very promising for hydrogen production. In this paper, the interconnected fluidized ... Keywords: chemical looping combustion, hydrogen production Interconnected fluidized beds

Junjiao Zhang; Jingzhou Jiang; Qiang Lu; Changqing Dong; Teng Zhang; Xinglei Liu; Zhiyong Liang; Yongping Yang

2010-12-01T23:59:59.000Z

345

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

346

Secular Sediment Waves, Channel Bed Waves, and Legacy Sediment  

E-Print Network (OSTI)

Secular Sediment Waves, Channel Bed Waves, and Legacy Sediment L. Allan James* Geography Department, University South Carolina Abstract The concept of sediment waves is reviewed and clarifications are proposed for nomenclature con- cerning vertical channel responses to large fluvial sediment fluxes over a period of a decade

James, L. Allan

347

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

348

Summary of four release consequence analyses for hypothetical nuclear waste repositories in salt and granite  

SciTech Connect

Release consequence methology developed under the Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) program has now been applied to four hypothetical repository sites. This paper summarizes the results of these four studies in order to demonstrate that the far-field methodology developed under the AEGIS program offers a practical approach to the post-closure safety assessment of nuclear waste repositories sited in deep continental geologic formations. The four studies are briefly described and compared according to the following general categories: physical description of the repository (size, inventory, emplacement depth); geologic and hydrologic description of the site and the conceptual hydrologic model for the site; description of release scenario; hydrologic model implementation and results; engineered barriers and leach rate modeling; transport model implementation and results; and dose model implementation and results. These studies indicate the following: numerical modeling is a practical approach to post-closure safety assessment analysis for nuclear waste repositories; near-field modeling capability needs improvement to permit assessment of the consequences of human intrusion and pumping well scenarios; engineered barrier systems can be useful in mitigating consequences for postulated release scenarios that short-circuit the geohydrologic system; geohydrologic systems separating a repository from the natural biosphere discharge sites act to mitigate the consequences of postulated breaches in containment; and engineered barriers of types other than the containment or absorptive type may be useful.

Cole, C.R.; Bond, F.W.

1980-12-01T23:59:59.000Z

349

Fire spread probabilities for experimental beds composed of mixedwood boreal forest fuels  

E-Print Network (OSTI)

that fire spread was largely determined by the heat sink, heat of combustion, and fuel bed depth. We found

Johnson, Edward A.

350

Parametric Investigation of the Performance of Solar Heating Systems with Rock Bed Storage  

Science Journals Connector (OSTI)

The performance of solar air collector domestic heating systems with rock bed storage, as obtained from theoretical analysis, is...

W. L. Dutre; J. Vanheelen

1981-01-01T23:59:59.000Z

351

Gasification and its emission characteristics for dried sewage sludge utilizing a fluidized bed gasifier  

Science Journals Connector (OSTI)

The effects of these parameters were, therefore, investigated through a series of experiments with a fluidized bed gasifier.

Seong-Wan Kang; Jong-In Dong; Jong-Min Kim…

2011-10-01T23:59:59.000Z

352

An assessment of waste fuel burning in operating circulating fluidized bed boilers  

SciTech Connect

Fluidized bed combustion (FBC), today's fastest growing boiler technology, has the flexibility to burn a wide range of fuels, including many waste fuels, while satisfying all present and anticipated environmental regulations. The first generation of FBC--atmospheric fluidized bed combustion (AFBC)--concentrated on ''bubbling'' fluidized bed designs. These systems have inherent limitations and experienced several problems. In response to these problems, circulating fluidized bed (CFB) technology was developed.

Gendreau, R.J.; Raymond, D.L.

1986-01-01T23:59:59.000Z

353

Fluid-bed studies of olefin production from methanol  

SciTech Connect

With newly developed technology, conversion of methanol to hydrocarbons represents the final link in the production of premium transportation fuels from coal or natural gas. The methanol-to-gasoline (MTG) process has been developed. The more readily scaled fixed-bed version is the heart of the New Zealand Gas-to-gasoline complex, which will produce 14,000 BPD high octane gasoline from 120 million SCFD gas. The fluid-bed version of the process, which is also available for commercial license, has a higher thermal efficiency and possesses substantial yield and octane advantages over the fixed-bed. Successful scale-up was completed in 1984 in a 100 BPD semi-works plant near Cologne, West Germany. The project funded jointly by the U.S. and German governments and an industrial consortium comprised of Mobil; Union Rheinsche Braunkohlen Kraftstoff, AG; and Uhde, GmbH. The 100 BPD MTG project was extended recently to demonstrate a related fluid bed process for selective conversion of methanol to light olefins (MTO). The products of the MTO reaction make an excellent feed to the commercially available Mobile-Olefins-to-Gasoline-and-Distillate process (MOGD) which selectively converts olefins to premium transportation fuels . A schematic of the combined processes is shown. Total liquid fuels production is typically greater than 90 wt% of hydrocarbon in the feed. Distillate/gasoline product ratios from the plant can be adjusted over a wide range to meet seasonal demands. This paper describes the initial scale-up of the MTO process from a micro-fluid-bed reactor (1-10 grams of catalyst) to a large pilot unit (10-25 kilograms of catalyst).

Socha, R.F.; Chang, C.D.; Gould, R.M.; Kane, S.E.; Avidan, A.A.

1986-03-01T23:59:59.000Z

354

Atmospheric fluidized-bed combustion. Technology status report  

SciTech Connect

The goal of DOE/METC's AFBC activities is to establish an engineering technology base by 1990, from which the industrial, commercial, and residential sectors can build and operate coal-fired AFBC systems. These systems will be capable of economically generating process steam, direct and indirect heat, and onsite electric power from coals of all ranks and sulfur contents in an environmentally acceptable manner. First-generation atmospheric fluidized-bed technology is considered commercial; a number of US boiler manufacturers are offering commercial units. However, many of these first units are products of empirical design and offer marginal gains in economics, performance, and reliability over conventional systems. In order to resolve the remaining technical issues and to broaden the market, DOE is pursuing advanced concepts. Development of this second-generation AFBC technology is directed toward small industrial, commercial, and residential applications. Penetration of these potential markets will require: (1) a 20 to 30% reduction in capital and operating costs over first-generation technology; (2) significant improvements in performance and reliability; and (3) compliance with existing and proposed New Source Performance Standards for environmental emissions. Current AFBC activities address: industrial operations, advanced concepts, and technology development. Four AFBC demonstration projects were active in FY 1984. The development of AFBC technology is directly supported by the evaluation of five advanced concepts by the M.W. Kellogg Company (circulating-bed FBC), Battelle Columbus Laboratories (spouted-bed FBC), Aerojet Energy Conversion Company (moving-bed FBC), Howard University (staged cascade FBC), and Arthur D. Little, Inc. (pulsed-bed FBC). These concepts may improve the economics and performance. 13 refs., 11 figs.

Not Available

1984-10-01T23:59:59.000Z

355

Great lakes fluidized-bed combustion. Final report  

SciTech Connect

A program was conducted to design, construct, and operate an industrial fluidized bed combustion (FBC) boiler demonstration plant with a capacity of 50,000 lb/h steam. The following were the objectives of the program: (1) to extend the fluidized bed boiler design by employing natural circulation cooling; (2) to design, build, operate, test, and demonstrate a fluidized bed boiler that could burn high sulfur coal in an environmentally acceptable manner; and (3) to obtain sufficient data for industry to make an objective appraisal of fluidized bed coal burning boilers. Following a five-year design, development, and construction effort, the demonstration plant was first operated in June of 1981. Initial operation identified several equipment and operating problems, particularly in the areas of the fuel preparation and fuel feed systems. Unit operation and availability steadily improved, culminating in a 30-day continuous run ending in May 1982. Following shutdown, major problem areas such as bed tube failures were addressed by C-E and rectified prior to the start of the test program. Shakedown/testing operation commenced on August 12, 1983. The objectives for the test program were to establish the unit operating conditions required to optimize SO/sub 2/ removal and combustion efficiency for different operating modes, and to evaluate the long-term performance of components which are essential for reliable FBC operation. A total of 23 tests were run from February 16, 1984 to April 19, 1984. The test results demonstrated that FBC is an environmentally and commercially sound technology. Specificially, the required sulfur removal, low NO/sub x//CO emissions and high combustion efficiencies can be readily achieved. This report identifies the effects of recycle, excess air, Ca/S mole ratio, and overfire air on combustion efficiency, boiler efficiency, and emissions. 6 refs., 97 figs., 8 tabs.

Not Available

1985-12-01T23:59:59.000Z

356

On interfacial instability as a cause of transverse subcritical bed Jeremy G. Venditti,1  

E-Print Network (OSTI)

On interfacial instability as a cause of transverse subcritical bed forms Jeremy G. Venditti,1. J. Bennett (2006), On interfacial instability as a cause of transverse subcritical bed forms, Water, 1997]. Ideas about the initiation of the dominant subcritical flow-transverse bed forms (ripples, dunes

Venditti, Jeremy G.

357

Biomass Gasification:? Produced Gas Upgrading by In-Bed Use of Dolomite  

Science Journals Connector (OSTI)

When some calcined dolomite (OCa·OMg) is used in the bed of a biomass gasifier of fluidized bed type the raw gas produced is cleaner than when only silica sand is used in it as fluidizing medium. In-bed dolomite changes the product distribution at the ...

Ana Olivares; María P. Aznar; Miguel A. Caballero; Javier Gil; Eva Francés; José Corella

1997-12-01T23:59:59.000Z

358

EXPERIMENTAL MEASUREMENTS OF THE INTERFACE THERMAL CONDUCTANCE OF A LITHIUM METATITANATE PEBBLE BED  

E-Print Network (OSTI)

, CA 90095 aliabousena@engineering.ucla.edu The thermal properties of the lithium ceramics pebble beds will help to create a reliable database of the thermal properties of the lithium ceramics pebble beds. I heat is transferred from the hot lithium ceramic pebble beds to the coolant. The thermal properties

Abdou, Mohamed

359

The Nature of Saltation and of 'Bed-Load' Transport in Water  

Science Journals Connector (OSTI)

...transported by a stream and a 'bed-load' has long remained undefined...light on the nature of bed-load transport. In particular, it has been shown that bed-load transport, by saltation, occurs...in the existing experimental data. The theoretical variation is...

1973-01-01T23:59:59.000Z

360

Evidence for detrital remanent magnetization carried by hematite in Devonian red beds from Spitsbergen; palaeomagnetic implications  

Science Journals Connector (OSTI)

......Regional bedding of the Wood say Formation red beds (136/8) and...composed of disintegrated red sandstones from Dicksonfjorden...titanomaghemite withm red bed deposits indicates...emphasized that the Wood Bay Forma- tion sandstone...Digico balanced flux-gate spinner, a single......

R. Løvlie; T. Torsvik; M. Jelenska; M. Levandowski

1984-11-01T23:59:59.000Z

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.


361

WindTurbineGenerator Introduction of the Renewable Micro-Grid Test-Bed  

E-Print Network (OSTI)

Introduction of the Renewable Micro-Grid Test-Bed Dr. Wenxin Liu Smart Micro-grid and Renewable Technology University Topology of the Overall Experimental Platform Photo of the Micro-grid Test-bed Overview of the Micro-grid Test-Bed Cubicle #1: Main & PV Simulator PV Simulator: 3kW, 0~200V, 18A Unidirectional

Johnson, Eric E.

362

PRECLOSURE CONSEQUENCE ANALYSES FOR LICENSE APPLICATION  

SciTech Connect

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

363

Epidemiological consequences of an ineffective Bordetella pertussis vaccine  

E-Print Network (OSTI)

The recent increase in Bordetella pertussis incidence (whooping cough) presents a challenge to global health. Recent studies have called into question the effectiveness of acellular B. pertussis vaccination in reducing transmission. Here we examine the epidemiological consequences of an ineffective B. pertussis vaccine. Using a dynamic transmission model, we find that: 1) an ineffective vaccine can account for the observed increase in B. pertussis incidence; 2) asymptomatic infections can bias surveillance and upset situational awareness of B. pertussis; and 3) vaccinating individuals in close contact with infants too young to receive vaccine (so called "cocooning" unvaccinated children) may be ineffective. Our results have important implications for B. pertussis vaccination policy and paint a complicated picture for achieving herd immunity and possible B. pertussis eradication.

Althouse, Benjamin M

2014-01-01T23:59:59.000Z

364

MFIX simulation of NETL/PSRI challenge problem of circulating fluidized bed  

In this paper, numerical simulations of NETL/PSRI challenge problem of circulating fluidized bed (CFB) using the open-source code Multiphase Flow with Interphase eXchange (MFIX) are reported. Two rounds of simulation results are reported including the first-round blind test and the second-round modeling refinement. Three-dimensional high fidelity simulations are conducted to model a 12-inch diameter pilot-scale CFB riser. Detailed comparisons between numerical results and experimental data are made with respect to axial pressure gradient profile, radial profiles of solids velocity and solids mass flux along different radial directions at various elevations for operating conditions covering different fluidization regimes. Overall, the numerical results show that CFD can predict the complex gas–solids flow behavior in the CFB riser reasonably well. In addition, lessons learnt from modeling this challenge problem are presented.

Li, Tingwen; Dietiker, Jean-Francois; Shahnam, Mehrdad

2012-12-24T23:59:59.000Z

365

Phase shift method to estimate solids circulation rate in circulating fluidized beds  

SciTech Connect

While solids circulation rate is a critical design and control parameter in circulating fluidized bed (CFB) reactor systems, there are no available techniques to measure it directly at conditions of industrial interest. Cold flow tests have been conducted at NETL in an industrial scale CFB unit where the solids flow has been the topic of research in order to develop an independent method which could be applied to CFBs operating under the erosive and corrosive high temperatures and pressures of a coal fired boiler or gasifier. The dynamic responses of the CFB loop to modest modulated aeration flows in the return leg or standpipe were imposed to establish a periodic response in the unit without causing upset in the process performance. The resulting periodic behavior could then be analyzed with a dynamic model and the average solids circulation rate could be established. This method was applied to the CFB unit operated under a wide range of operating conditions including fast fluidization, core annular flow, dilute and dense transport, and dense suspension upflow. In addition, the system was operated in both low and high total solids inventories to explore the influence of inventory limiting cases on the estimated results. The technique was able to estimate the solids circulation rate for all transport circulating fluidized beds when operating above upper transport velocity, U{sub tr2}. For CFB operating in the fast fluidized bed regime (i.e., U{sub g}< U{sub tr2}), the phase shift technique was not successful. The riser pressure drop becomes independent of the solids circulation rate and the mass flow rate out of the riser does not show modulated behavior even when the riser pressure drop does.

Ludlow, James Christopher [U.S. DOE (retired); Panday, Rupen [REM; Shadle, Lawrence J. [U.S. DOE

2013-01-01T23:59:59.000Z

366

Numerical study of hydrogen production by the sorption-enhanced steam methane reforming process with online CO2 capture as operated in fluidized bed reactors  

Science Journals Connector (OSTI)

A three-dimensional (3D) Eulerian two-fluid model with an in-house code was developed to simulate the gas-particle two-phase flow in the fluidized bed reactors. The CO2 capture with Ca-based sorbents in the steam

Yuefa Wang; Zhongxi Chao; Hugo A. Jakobsen

2011-08-01T23:59:59.000Z

367

CFD simulation of hydrodynamics on the dense zone on a 65 t/h oil shale-fired high–low bed CFB boiler  

Science Journals Connector (OSTI)

Abstract Gas–solid flow behavior in a 65 t/h oil shale-fired high–low bed CFB boiler obtained by the revamping of a 75 t/h pulverized coal-fired boiler has been simulated using a Eulerian–Eulerian model (EEM) with kinetic theory of granular flow by the commercial CFD software package, Fluent. Two-dimensional (2D) transient and three-dimensional (3D) steady flows were simulated for the gas and the solid phase, respectively. The comparative study with regard to turbulence and drag model was performed by 2D simulation. The simulated results agreed reasonably with the experimental data and showed that Swirl-modified RNG k-?-Per phase model and Gidaspow drag model could predict preferably the internal circulation process. Gas–solid flow profiles were obtained by 3D steady simulation for solid velocity, pressure, solid volume fraction, and granular temperature and the internal circulation characteristics of the boiler were further understood in detail. The results showed that the pressure difference between the main and side bed and the distributions of solid velocity and volume fraction illustrated the mechanism of internal circulation process. The fluidized velocity in the side beds is lower and wear of immersed tubes is also lower. The granular temperature is higher near the immersed tube bundle. This research established the foundation for the design and large-scale of high–low bed CFB.

Qing Wang; Jianbo Xiao; Hongpeng Liu

2013-01-01T23:59:59.000Z

368

Characterization of Biofilm in 200W Fluidized Bed Reactors  

SciTech Connect

Contaminated groundwater beneath the 200 West Area at the Hanford Site in Southeast Washington is currently being treated using a pump and treat system to remove organics, inorganics, radionuclides, and metals. A granular activated carbon-based fluidized bed reactor (FBR) has been added to remove nitrate, hexavalent chromium and carbon tetrachloride. Initial analytical results indicated the microorganisms effectively reduced many of the contaminants to less than cleanup levels. However shortly thereafter operational upsets of the FBR include carbon carry over, over production of microbial extracellular polymeric substance (biofilm) materials, and over production of hydrogen sulfide. As a result detailed investigations were undertaken to understand the functional diversity and activity of the microbial community present in the FBR over time. Molecular analyses including terminal restriction fragment length polymorphism analysis, quantitative polymerase chain reaction and fluorescent in situ hybridization analyses were performed on the microbial community extracted from the biofilm within the bed and from the inoculum, to determine functional dynamics of the FBR bed over time and following operational changes. Findings from these analyses indicated: 1) the microbial community within the bed was completely different than community used for inoculation, and was likely from the groundwater; 2) analyses early in the testing showed an FBR community dominated by a few Curvibacter and Flavobacterium species; 3) the final sample taken indicated that the microbial community in the FBR bed had become more diverse; and 4) qPCR analyses indicated that bacteria involved in nitrogen cycling, including denitrifiers and anaerobic ammonia oxidizing bacteria, were dominant in the bed. These results indicate that molecular tools can be powerful for determining functional diversity within FBR type reactors. Coupled with micronutrient, influent and effluent chemistry evaluations, a more complete understanding of the balance between system additions (nutrients, groundwater) and biology can be achieved, thus increasing long-term predictions of performance. These analyses uniquely provide information that can be used in optimizing the overall performance, efficiency, and stability of the system both in real time as well as over the long-term, as the system design is altered or improved and/or new streams are added.

Lee, Michelle H.; Saurey, Sabrina D.; Lee, Brady D.; Parker, Kent E.; Eisenhauer, Emalee ER; Cordova, Elsa A.; Golovich, Elizabeth C.

2014-09-29T23:59:59.000Z

369

Fluidized-Bed Waste-Heat Recovery System development. Semiannual report, February 1-July 31, 1982  

SciTech Connect

The Fluidized-Bed Waste-Heat Recovery (FBWHR) System is designed to preheat this combustion air using the heat available in dirty flue gas streams. In this system, a recirculating medium is heated by the flue gas in a fluidized bed. The hot medium is then removed from the bed and placed in a second fluidized bed where it is fluidized by the combustion air. Through this process, the combustion air is heated. The cooled medium is then returned to the first bed. Initial development of this concept is for the aluminum smelting industry.

Cole, W. E.; DeSaro, R.; Griffith, J.; Joshi, C.

1982-08-01T23:59:59.000Z

370

Characterization of Solid Emissions from Atmospheric Fluidized-Bed Combustion of Two Czech Lignites  

Science Journals Connector (OSTI)

In fluidized-bed combustion, particles of coal burn within the bed of vigorously moving smaller inert particles with bed temperatures between 1000 and 1300 K. Due to intense heat transfer from the burning particle to bed particles and percolating gas, the temperature of a particle is on average 200 K above that of the bed (29, 30). ... Two lignites from the Centrum mine and the Vršany open pit mine (North Bohemian Coal Basin) were used in this study. ... The reactor is equipped with a supplementary natural gas burner, a feeding system, and measuring and control peripherals. ...

Ji?í Smolík; Jaroslav Schwarz; Václav Veselý; Ivana Sýkorová; Jan Kuc?era; Vladimír Havránek

1999-09-01T23:59:59.000Z

371

A case history of a fixed bed, coal-derived oil hydrotreater  

Science Journals Connector (OSTI)

With the apparent shrinkage in the worldwide supply of liquid hydrocarbon fuels, upgrading of coal-derived liquids to synthetic crude oils will eventually emerge as a commercial entity. Although the Char-Oil-Energy Development (COED) Project has been shelved in the short term, information about the reaction engineering of the upgrading of coal-derived liquids by hydrotreatment in the COED Process should be relevant to upgrading technologies for other coal liquefaction processes. The COED Process was developed by FMC Corporation and the Office of Coal Research (now DOE) in the late 1960's and early 1970's. The process produced a synthetic crude oil, medium Btu gas and char by multi-stage, fluidized bed pyrolysis of coal. The raw coal-tar produced by pyrolysis was upgraded to synthetic crude oil by catalytic, fixed-bed hydrotreatment. Raw coal-tar has different properties from petroleum-derived oils, and upgrading by hydrotreatment is not an off-the-shelf technology. A 30 barrel per day fixed-bed hydrotreater was constructed and operated at the COED pilot plant site. The pilot plant hydrotreater design was based on conventional petroleum residua hydrotreatment technology together with bench-scale hydrotreatment tests performed by ARCO in the 1960's utilizing coal-tars produced in a process development unit. The pilot plant hydrotreater did operate for about four years providing valuable information about the reaction engineering of the hydrotreatment process as well as providing numerous samples for applications studies performed by other DOE contractors and interested potential users of the COED syncrude. Of note, 50,000 gallons of COED syncrude were supplied to the U.S. Naval Ship Engineering Center for shipboard testing in the boilers of the U.S.S. Johnston on November 15–16th, 1973. This paper deals with the reaction engineering of the guard chamber and fixed-bed hydrotreatment reactors at the COED facility. Of major importance is the study of the role of the feedstock (pyrolysis coal-tar) properties and their effects on the catalysts utilized in the reactors. A working kinetic model has been derived that could allow a designer to optimize a particular set of design parameters and a plant operator to determine catalyst life. A quantitative comparison has been made of the effect of metals content of coal-derived oils and petroleum resids on catalyst deactivation.

Marvin I. Greene

1981-01-01T23:59:59.000Z

372

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, John E. (Morgantown, WV)

1993-01-01T23:59:59.000Z

373

Adsorbent and adsorbent bed for materials capture and separation processes  

DOE Patents (OSTI)

A method device and material for performing adsorption wherein a fluid mixture is passed through a channel in a structured adsorbent bed having a solid adsorbent comprised of adsorbent particles having a general diameter less than 100 um, loaded in a porous support matrix defining at least one straight flow channel. The adsorbent bed is configured to allow passage of a fluid through said channel and diffusion of a target material into said adsorbent under a pressure gradient driving force. The targeted molecular species in the fluid mixture diffuses across the porous support retaining layer, contacts the adsorbent, and adsorbs on the adsorbent, while the remaining species in the fluid mixture flows out of the channel.

Liu, Wei (Richland, WA)

2011-01-25T23:59:59.000Z

374

Controlled waste-oil biodegradation at existing drying beds  

SciTech Connect

A feasibility study at the Portsmouth Uranium Enrichment Facility to determine if sludge drying beds at a sewage treatment plant could be used as controlled waste oil biodegradation plots has been completed. A greenhouse-like enclosure would be constructed over three 9.1 meter by 21.3 meter beds to allow for year-round use, and any waste oil runoff would be collected by existing leachate piping. It has been determined that this proposed facility could dispose of existing radioactive waste oil generation (7200 liters/year) from the Gaseous Diffusion Plant (GDP); however, it would be inadequate to handle radioactive waste oils from the new Gas Centrifuge Enrichment Plant (GCEP) as well. The study reviewed nuclear criticality constraints, biodegradation technology, and the capital cost for an enclosed biodegradation facility.

Hary, L.F.

1982-01-01T23:59:59.000Z

375

A future for nuclear energy: pebble bed reactors  

Science Journals Connector (OSTI)

Pebble Bed Reactors could allow nuclear plants to support the goal of reducing global climate change in an energy hungry world. They are small, modular, inherently safe, use a demonstrated nuclear technology and can be competitive with fossil fuels. Pebble bed reactors are helium cooled reactors that use small tennis ball size fuel balls consisting of only 9 grams of uranium per pebble to provide a low power density reactor. The low power density and large graphite core provide inherent safety features such that the peak temperature reached even under the complete loss of coolant accident without any active emergency core cooling system is significantly below the temperature that the fuel melts. This feature should enhance public confidence in this nuclear technology. With advanced modularity principles, it is expected that this type of design and assembly could lower the cost of new nuclear plants removing a major impediment to deployment.

Andrew C. Kadak

2005-01-01T23:59:59.000Z

376

A free radical equilibrium in the fluidized bed retort  

SciTech Connect

The solid-recycle fluidized bed retort has been used to study gas phase local equilibria in an oil shale pyrolyzer. In the LLNL pilot scale retort, light gases, methane, ethane, ethylene, and propylene, form in a ratio that is inconsistent with equilibration, and they are not equilibrated when recycled. However, in a variety of fluidized bed retorting experiments, the free radical precursors of these gases come to a steady state that requires a transient free radical equilibrium. The steady state is established very rapidly, without need for gas recycle. The 1- and 2-butyl free radicals have been investigated as representative intermediates. The steady state mechanism extends to the entire homologous series of free radicals, and offers a means to achieve improved liquid product yield. 12 refs., 4 figs., 2 tabs.

Coburn, T.T.; Droege, M.W.

1986-11-01T23:59:59.000Z

377

Fluidized bed combustor and removable windbox and tube assembly therefor  

DOE Patents (OSTI)

A fluidized bed combustor comprises a housing having a chamber therein with a top having a discharge for the gases which are generated in the chamber and a bottom with a discharge for heated fluid. An assembly is arranged in the lower portion of the chamber and the assembly includes a lower plate which is mounted on a support flange of the housing so that it is spaced from the bottom of the chamber and defines a fluid plenum between it and the bottom of the chamber for the discharge of heated fluid. The assembly includes a heat exchanger inlet plenum having tubes therethrough for the passage of fluidizer air and a windbox above the heat exchanger plenum which has a distributor plate top wall. A portion of the chamber above the top wall defines a fluidized bed.

DeFeo, Angelo (Totowa, NJ); Hosek, William (Mt. Tabor, NJ)

1983-01-01T23:59:59.000Z

378

Fluidized bed combustor and removable windbox and tube assembly therefor  

DOE Patents (OSTI)

A fluidized bed combustor comprises a housing having a chamber therein with a top having a discharge for the gases which are generated in the chamber and a bottom with a discharge for heated fluid. An assembly is arranged in the lower portion of the chamber and the assembly includes a lower plate which is mounted on a support flange of the housing so that it is spaced from the bottom of the chamber and defines a fluid plenum between it and the bottom of the chamber for the discharge of heated fluid. The assembly includes a heat exchanger inlet plenum having tubes therethrough for the passage of fluidizer air and a windbox above the heat exchanger plenum which has a distributor plate top wall. A portion of the chamber above the top wall defines a fluidized bed.

DeFeo, Angelo (Totowa, NJ); Hosek, William S. (Mt. Tabor, NJ)

1981-01-01T23:59:59.000Z

379

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

380

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

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

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

382

Inclined fluidized bed system for drying fine coal  

DOE Patents (OSTI)

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

383

Four Rivers second generation Pressurized Circulating Fluidized Bed Combustion Project  

SciTech Connect

Air Products has been selected in the DOE Clean Coal Technology Round V program to build, own, and operate the first commercial power plant using second generation Pressurized Circulating Fluidized Bed (PCFB) combustion technology. The four Rivers Energy Project (Four Rivers) will produce up to 400,000 lb/hr steam, or an equivalent gross capacity of 95 MWe. The unit will be used to repower an Air Products chemicals manufacturing facility in Calvert City, Kentucky.

Holley, E.P.; Lewnard, J.J. [Air Products and Chemicals, Inc. (United States); von Wedel, G. [LLB Lurgi Lentjes Babcock Energietechnik (GmbH); Richardson, K.W. [Foster Wheeler Energy Corp. (United States); Morehead, H.T. [Westinghouse Electric Corp. (United States)

1995-04-01T23:59:59.000Z

384

Biological control of Rhizoctonia solani in greenhouse bedding plant production  

E-Print Network (OSTI)

of Comm!ttee) (Robert E. Pettit) (Member) (David id. Reed) (Member) "7~+ (Grant Yest) (Head of. Depart tment) Deceriber 1983 ABSTRACT Biological control of Rhizoctonia solani in greenhouse bedding plant production. IDecember 1983) John... iviichael Brown B. S, East Texas State University. Chairman of Advisory Committee: Dr . A . E . Nightingale . Isolates of Trichoderma harzianum, T. hamatum, and Gliocladium spp. capable of inhibiting the growth of Rhizoctonia solani, which may cause...

Brown, John Michael

1983-01-01T23:59:59.000Z

385

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

386

Analysis of major risks associated with hydrocarbon storage caverns in bedded salt rock  

Science Journals Connector (OSTI)

Salt rock is internationally accepted as an ideal medium for energy storage. As an energy storage structure, the safety of hydrocarbon storage caverns in salt rock is related to the national economy and to social public security. Risk analysis is an important method of engineering safety evaluation. In this paper the major risks associated with hydrocarbon storage caverns in bedded salt rock are defined. The major risks are classified under the headings of ‘oil and gas leakage’, ‘ground subsidence’, and ‘cavern failure’, and are discussed under these topical titles. The factors leading to the major risks associated with storage caverns are identified by reviewing descriptions of major accidents of salt storage caverns around the world. Fault tree models for the three major risks are established and analyzed. Basic paths of the risk and their occurrence probability ranking are derived. The risk factors which contribute greatly to the risk are identified by calculating the importance degree of all the basic events. Finally, a comprehensive evaluation methodology for major risk loss is generated based on the analytic hierarchy process. This provides a theoretical foundation for the evaluation and prevention of major risks in the construction and operation of storage caverns in bedded salt rock.

Chunhe Yang; Wenjun Jing; J.J.K. Daemen; Guimin Zhang; Chao Du

2013-01-01T23:59:59.000Z

387

Method for immobilizing particulate materials in a packed bed  

DOE Patents (OSTI)

The present invention pertains generally to immobilizing particulate matter contained in a "packed" bed reactor so as to prevent powder migration, compaction, coalescence, or the like. More specifically, this invention relates to a technique for immobilizing particulate materials using a microporous foam-like polymer such that a) the particulate retains its essential chemical nature, b) the local movement of the particulate particles is not unduly restricted, c) bulk powder migration and is prevented, d) physical and chemical access to the particulate is unchanged over time, and e) very high particulate densities are achieved. The immobilized bed of the present invention comprises a vessel for holding particulate matter, inlet and an outlet ports or fittings, a loosely packed bed of particulate material contained within the vessel, and a three dimensional porous matrix for surrounding and confining the particles thereby fixing the movement of individual particle to a limited local position. The established matrix is composed of a series of cells or chambers comprising walls surrounding void space, each wall forming the wall of an adjacent cell; each wall containing many holes penetrating through the wall yielding an overall porous structure and allowing useful levels of gas transport.

Even, Jr., William R. (Livermore, CA); Guthrie, Stephen E. (Livermore, CA); Raber, Thomas N. (Livermore, CA); Wally, Karl (Lafayette, CA); Whinnery, LeRoy L. (Livermore, CA); Zifer, Thomas (Manteca, CA)

1999-01-01T23:59:59.000Z

388

Fluidized-bed gasification of an eastern oil shale  

SciTech Connect

The current conceptual HYTORT process design for the hydroretorting of oil shales employs moving-bed retorts that utilize shale particles larger than 3 mm. Work at the Institute of Gas Technology (IGT) is in progress to investigate the potential of high-temperature (1100 to 1300 K) fluidized-bed gasification of shale fines (<3 mm size) using steam and oxygen as a technique for more complete utilization of the resource. Synthesis gas produced from fines gasification can be used for making some of the hydrogen needed in the HYTORT process. After completing laboratory-scale batch and continuous gasification tests with several Eastern oil shales, two tests with Indiana New Albany shale were conducted in a 0.2 m diameter fluidized-bed gasification process development unit (PDU). A conceptual gasifier design for 95% carbon conversion was completed. Gasification of 20% of the mined shale can produce the hydrogen required by the HYTORT reactor to retort 80% of the remaining shale. 12 refs., 1 fig., 5 tabs.

Lau, F.S.; Rue, D.M.; Punwani, D.V.; Rex, R.C. Jr.

1987-01-01T23:59:59.000Z

389

Treatment of trichloroethene (TCE) with a fluidized-bed bioreactor  

SciTech Connect

Fluidized-bed bioreactors (FBBR`s) offer a promising alternative to existing treatment technologies for the treatment of water contaminated with chlorinated solvents. The objective of this research was to test a laboratory-scale FBBR for removal of trichloroethene (TCE) from groundwater and to study the FBBR kinetic behavior so that field-scale treatment systems could be designed. Phenol was selected as the growth substrate for biofilm-forming microorganisms enriched from activated-sludge because phenol induces enzymes capable of cometabolizing TCE and lesser chlorinated ethenes. The biofilm forming microorganisms were identified as Pseudomonas putida, a common soil bacterium. Experiments with a conventional, single-pass FBBR addressed TCE removal as effected by changes in TCE loading, phenol loading, and media type. In this study, TCE removal using quartz filter sand and garnet filter sand as the biofilm attachment media was measured. Removal ranged from 20 to 60% and was not affected by the media type. Also, removal was not affected by inlet TCE concentration over the range of 100 to 500 {micro}g/L provided the phenol loading was decreased with increasing TCE loading. The FBBR was capable of complete phenol removal at an inlet concentration of 20 to 25 mg/L and an empty-bed contact time of 2.7 minutes. However, the empty-bed contact time was insufficient to sustain greater than 40 to 50% removal of TCE in a nutrient-amended groundwater.

Foeller, J.R.; Segar, R.L. Jr. [Univ. of Missouri, Columbia, MO (United States). Dept. of Civil Engineering

1997-12-31T23:59:59.000Z

390

Assessment of adsorber bed designs in waste-heat driven adsorption cooling systems for vehicle air conditioning and refrigeration  

E-Print Network (OSTI)

Assessment of adsorber bed designs in waste-heat driven adsorption cooling systems for vehicle air conditioning Finned tube adsorber bed Specific cooling power Adsorber bed to adsorbent mass ratio a b s t r a c t Adsorber bed design strongly affects the performance of waste-heat driven adsorption cooling systems (ACS

Bahrami, Majid

391

Reply to comment by Claude Michel on ``A general power equation for predicting bed load transport rates in gravel  

E-Print Network (OSTI)

Reply to comment by Claude Michel on ``A general power equation for predicting bed load transport Michel on ``A general power equation for predicting bed load transport rates in gravel bed rivers of our transport equation. [2] Although some bed load transport data exhibit non- linear trends in log

392

Hydraulic fracturing tests in anhydrite interbeds in the WIPP, Marker Beds 139 and 140  

SciTech Connect

Hydraulic fracturing tests were integrated with hydrologic tests to estimate the conditions under which gas pressure in the disposal rooms in the Waste Isolation Pilot Plant, Carlsbad, NM (WIPP) will initiate and advance fracturing in nearby anhydrite interbeds. The measurements were made in two marker beds in the Salado formation, MB139 and MB140, to explore the consequences of existing excavations for the extrapolation of results to undisturbed ground. The interpretation of these measurements is based on the pressure-time records in two injection boreholes and several nearby hydrologic observation holes. Data interpretations were aided by post-test borehole video surveys of fracture traces that were made visible by ultraviolet illumination of fluorescent dye in the hydraulic fracturing fluid. The conclusions of this report relate to the upper- and lower-bound gas pressures in the WIPP, the paths of hydraulically and gas-driven fractures in MB139 and MB140, the stress states in MB139 and MB140, and the probable in situ stress states in these interbeds in undisturbed ground far away from the WIPP.

Wawersik, W.R., Carlson, L.W., Henfling, J.A., Borns, D.J., Beauheim, R.L. [Sandia National Labs., Albuquerque, NM (United States); Howard, C.L. [RE/SPEC Inc., Albuquerque, NM (United States); Roberts, R.M., [INTERA Inc., Albuquerque, NM (United States)

1997-05-01T23:59:59.000Z

393

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

394

Towards an Understanding of Board IT Governance: Antecedents and Consequences.  

E-Print Network (OSTI)

??Board involvement in Information Technology (IT) governance and the antecedents and consequences of such involvement are examined from both a theoretical and practical perspective. Practitioner… (more)

Jewer, Jennifer

2009-01-01T23:59:59.000Z

395

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

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

NNSA Releases Pictures, Video of Consequence Management Response Teams Deploying to Japan WASHINGTON, D.C. The National Nuclear Security Administration, a semi-autonomous...

396

1 -SUBTIDAL 2 -INTERTIDAL RB ROCK UB UNCONSOLIDATED AB AQUATIC BED RF -REEF OW -OPEN WATER/ AB AQUATIC BED RF REEF RS ROCKY SHORE US -UNCONSOLIDATED  

E-Print Network (OSTI)

M - MARINE 1 - SUBTIDAL 2 - INTERTIDAL RB ­ ROCK UB ­ UNCONSOLIDATED AB ­ AQUATIC BED RF - REEF OW - OPEN WATER/ AB ­ AQUATIC BED RF­ REEF RS ­ ROCKY SHORE US - UNCONSOLIDATED BOTTOM BOTTOM Unknown Bottom ­ UNCONSOLIDATED AB ­ AQUATIC RF ­ REEF OW - OPEN WATER/ AB ­ AQUATIC RF­ REEF SB ­ STREAMBED RS - ROCKY US

Gray, Matthew

397

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

398

Investigation of biomass combustion systems using CFD techniques: a parametric study of packed-bed burning characteristics  

Science Journals Connector (OSTI)

In this paper, mathematical equations governing the fluid flow, heat and mass transfer and heterogeneous reactions in packed-bed combustion systems are described and sub-models for individual processes are presented. A model estimating the mixing rate between the under-grate air and the released volatile gases is described. Parametric study was carried out to assess the effects of fuel moisture content, kinetic rate of devolatilisation, primary air flow rate and particle mixing levels caused by grate movement. Useful conclusions were drawn in terms of flame temperature, reaction zone thickness, mass loss rate, combustion staging and residual carbon in ash.

Yao Bin Yang; Jim Goodfellow; Vida N. Sharifi; Jim Swithenbank

2006-01-01T23:59:59.000Z

399

Advertising Health Care: Causes and Consequences  

Science Journals Connector (OSTI)

Abstract An overview and a discussion of the key research and policy issues related to advertising in health care markets are presented in this article. Based on the two workhorse models of advertising from the economics literature – informative and persuasive advertising – the main effects of advertising in terms of market outcomes (quantity, price, quality, and entry) are discussed. The overview concentrates on discussing advertising of health care providers and advertising of prescription drugs, which are treated separately. The discussion provides tentative policy implications with respect to the social benefits and costs of advertising in health care markets.

O.R. Straume

2014-01-01T23:59:59.000Z

400

Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion (FBC) system. Technical progress report No. 3, [April 1, 1993--June 30, 1993  

SciTech Connect

This technical report summarizes the research work performed and progress achieved during the period of during the period of April 1, 1993 to June 30, 1993. The erosion test was conducted in the bench-scale FBC model along with the preparation of the test particles/tube specimens. The effect of the tube-to-distributor (T-to-D) clearance was discussed on the tube specific weight loss for low, medium, and high superficial velocities. Electrostatic impact probes for measuring the particle-surface collision frequency were designed to verify the some of the measurement and to identify the primary erosion points. The erosion models were briefly to understand the phenomena of in-bed erosion. The project has been progressing well. Instrumentation for the erosion-measuring will be continued: to measure the tube weight loss under different operating conditions. Development of the electrostatic probes will be continued and implemented for measuring the particle-tube collision frequency in the bench-scale FBC model.

Lee, Seong W.

1993-07-01T23:59:59.000Z

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,
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

Functional consequences of realistic biodiversity changes in a marine ecosystem  

E-Print Network (OSTI)

Functional consequences of realistic biodiversity changes in a marine ecosystem Matthew E. S, 2007) Declines in biodiversity have prompted concern over the conse- quences of species loss the functional consequences of realistic, nonrandom changes in biodiversity. Instead, most designs have used

Brody, James P.

402

COMMENTARY/COMMENTAIRE The radiological consequences of the Chernobyl  

E-Print Network (OSTI)

COMMENTARY/COMMENTAIRE The radiological consequences of the Chernobyl accident The First­22 March 1996 Eric Voice Abstract: The human health consequences of the Chernobyl accident in 1986 have are discussed with particular focus on thyroid cancers and exposures to iodine-131. Key words: Chernobyl

Shlyakhter, Ilya

403

Economic Consequences of Health Status: A Review of the Evidence  

E-Print Network (OSTI)

Economic Consequences of Health Status: A Review of the Evidence Amar A. Hamoudi and Jeffrey D Papers #12;CID Working Paper no. 30 Economic Consequences of Health Status: A Review of the Evidence Amar A. Hamoudi and Jeffrey D. Sachs Abstract The correlation between health and economic performance

404

Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for internal dosimetry. Volume 1: Main report  

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 internal dosimetry models.

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

405

Probabilistic accident consequence uncertainty analysis -- Late health effects uncertainty assessment. Volume 1: Main report  

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.

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

406

Probabilistic accident consequence uncertainty analysis -- Early health effects uncertainty assessment. Volume 1: Main report  

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 early health effects models.

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); Grupa, J.B. [Netherlands Energy Research Foundation (Netherlands)

1997-12-01T23:59:59.000Z

407

Mechanistic kinetic modeling of the hydrocracking of complex feedstocks  

E-Print Network (OSTI)

subclasses by distinguishing the isomers of a class according to the number of methyl branches. The kinetic model is plugged into an adiabatic multi-bed trickle flow reactor model. The model contains 33 feedstock and temperature independent parameters which...

Kumar, Hans

2009-05-15T23:59:59.000Z

408

SPOUTED BED ELECTRODES (SBE) FOR DIRECT UTILIZATION OF CARBON IN FUEL CELLS  

SciTech Connect

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

409

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

410

Effect of bed medium moisture on {alpha}-pinene removal by biofilters  

SciTech Connect

In this study, laboratory scale continuous flow bioifilters were used to determine the effect of bed medium moisture on biofilter performance when treating off-gases containing {alpha}-pinene. Biofilters were packed using a proprietary wood waste bed medium and were operated at a flow rate of 700 ml of air per min, yielding an empty bed residence time of 2 minutes. For the bed medium moisture levels tested, a biofilter bed held at 100% moisture on a dry weight basis demonstrated the best overall {alpha}-pinene removal results. Volumetric productivity and percent removal were higher, while the time to reach maximum removal efficiency was decreased compared to biofilters operated at 40, 60 and 80% bed medium moisture. Results indicate that control of moisture in a biofilter is important for maximum removal of {alpha}-pinene.

Lee, B.D.; Apel, W.A.; Cook, L.L. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States); Nichols, K.M. [Weyerhaeuser, Federal Way, WA (United States)

1996-12-31T23:59:59.000Z

411

Test research of bed ash coolers for a 50 MWe CFB boiler  

SciTech Connect

CFB boilers have been developed and commercialized in China. As one of the main auxiliaries of FBC boilers, the bed ash cooler plays an important role in regular operation of the boilers. A 50 MWe 2-shaped CFB boiler will be put into operation in North China. Many kinds of bed ash cooling systems for this boiler had been designed and compared. Then the optimum bed ash coolers were determined and made. Experimental research and pilot-scale test for the bed ash coolers were also carried out. The result indicates that the bed ash cooler can be operated reliably and can meet the demand for cooling bed ash of the 50 MWe CFB boiler. The test data are very useful for further improving the performance of ash coolers.

Chen, H.P.; Lu, J.D.; Lin, Z.J.; Liu, D.C. [Huazhong Univ. of Science and Technology, Wuhan, Hubei (China). National Lab. of Coal Combustion; Hu, L.L.; Xie, P.J.; Yan, H.X.; Liu, M.C. [Hubei Boiler Auxiliary Factory, Jingshan, Hubei (China)

1995-12-31T23:59:59.000Z

412

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

413

Appalachian basin coal-bed methane: Elephant or flea  

SciTech Connect

Historically, interest in the Appalachian basin coal-bed methane resource extends at least over the last 50 years. The Northern and Central Appalachian basins are estimated to contain 61 tcf and 5 tcf of coal-bed methane gas, respectively. Development of this resource has not kept pace with that of other basins, such as the Black Warrior basin of Alabama of the San Juan basin of northern New Mexico and Colorado. Without the benefit of modern completion, stimulation, and production technology, some older Appalachian basin coal-bed methane wells were reported to have produced in excess of 150 used here to characterize some past projects and their results. This work is not intended to comprise a comprehensive survey of all Appalachian basin projects, but rather to provide background information from which to proceed for those who may be interested in doing so. Several constraints to the development of this resource have been identified, including conflicting legal rights of ownership of the gas produced from the coal seams when coal and conventional oil and gas rights are controlled by separate parties. In addition, large leaseholds have been difficult to acquire and finding costs have been high. However, the threshold of minimum economic production may be relatively low when compared with other areas, because low-pressures pipelines are available and gas prices are among the highest in the nation. Interest in the commercial development of the resource seems to be on the increase with several projects currently active and more reported to be planned for the near future.

Hunt, A.M. (Dames and Moore, Cincinnati, OH (United States))

1991-08-01T23:59:59.000Z

414

CERTS Microgrid Laboratory Test Bed - PIER Final Project Report  

SciTech Connect

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 distinguish between normal and faulted operation. The controls were found to be robust and under all conditions, including difficult motor starts. The results from these test 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 mroe of the CERTS Microgrid concepts.

Eto, Joseph H.; Eto, Joseph H.; Lasseter, Robert; Schenkman, Ben; Klapp, Dave; Linton, Ed; Hurtado, Hector; Roy, Jean; Lewis, Nancy Jo; Stevens, John; Volkommer, Harry

2008-07-25T23:59:59.000Z

415

Fluidized-bed bioreactor process for the microbial solubiliztion of coal  

DOE Patents (OSTI)

A fluidized-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fluidized-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fluidized-bed bioreactor.

Scott, Charles D. (Oak Ridge, TN); Strandberg, Gerald W. (Farragut, TN)

1989-01-01T23:59:59.000Z

416

Fluidized-bed bioreactor system for the microbial solubilization of coal  

DOE Patents (OSTI)

A fluidized-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fluidized-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fluidized-bed bioreactor. 2 figs.

Scott, C.D.; Strandberg, G.W.

1987-09-14T23:59:59.000Z

417

Fixed-bed bioreactor system for the microbial solubilization of coal  

DOE Patents (OSTI)

A fixed-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fixed-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the large scale production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fixed-bed bioreactor. 1 fig., 1 tab.

Scott, C.D.; Strandberg, G.W.

1987-09-14T23:59:59.000Z

418

Standby cooling system for a fluidized bed boiler  

DOE Patents (OSTI)

A system for protecting components including the heat exchangers of a fluidized bed boiler against thermal mismatch. The system includes an injection tank containing an emergency supply of heated and pressurized feedwater. A heater is associated with the injection tank to maintain the temperature of the feedwater in the tank at or about the same temperature as that of the feedwater in the heat exchangers. A pressurized gas is supplied to the injection tank to cause feedwater to flow from the injection tank to the heat exchangers during thermal mismatch.

Crispin, Larry G. (Akron, OH); Weitzel, Paul S. (Canal Fulton, OH)

1990-01-01T23:59:59.000Z

419

Hydraulically refueled battery employing a packed bed metal particle electrode  

DOE Patents (OSTI)

A secondary zinc air cell, or another selected metal air cell, employing a spouted/packed metal particle bed and an air electrode. More specifically, two embodiments of a cell, one that is capable of being hydraulically recharged, and a second that is capable of being either hydraulically or electrically recharged. Additionally, each cell includes a sloped bottom portion to cause stirring of the electrolyte/metal particulate slurry when the cell is being hydraulically emptied and refilled during hydraulically recharging of the cell.

Siu, Stanley C. (Castro Valley, CA); Evans, James W. (Piedmont, CA)

1998-01-01T23:59:59.000Z

420

Packed bed carburization of tantalum and tantalum alloy  

DOE Patents (OSTI)

Packed bed carburization of a tantalum or tantalum alloy object. A method for producing corrosion-resistant tantalum or tantalum alloy objects is described. The method includes the steps of placing the object in contact with a carburizing pack, heating the packed object in vacuum furnace to a temperature whereby carbon from the pack diffuses into the object forming grains with tantalum carbide along the grain boundaries, and etching the surface of the carburized object. This latter step removes tantalum carbides from the surface of the carburized tantalum object while leaving the tantalum carbide along the grain boundaries.

Lopez, Peter C. (Espanola, NM); Rodriguez, Patrick J. (Espanola, NM); Pereyra, Ramiro A. (Medanales, NM)

1999-01-01T23:59:59.000Z

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.


421

Combustion of Cattle Manure in a Fluidized Bed Combustor  

E-Print Network (OSTI)

. Experiments were conducted with -20 to +20 percent excess air and at bed temperatures ranging from 600?C (1112?F) to 800?C (1472?F). Experimental data revealed that the gasification efficiencies ranged from 90 to 98 percent, while the combustion... of manure (A, B, C, 0, E, and F) were obtained. The gasification and partial oxidation results for manure A, B, and C (supplied by Hill Feed Yard and Biocon Division of Anderson Peat Company) were reported in references [6 and BJ. The thermochemical...

Annamalai, K.; Colaluca, M. A.; Ibrahim, M. Y.; Sweeten, J. M.

422

Experimental study of fluidized bed combustion of feedlot manure  

E-Print Network (OSTI)

Characteristics 2. 2 Gasification 2. 3 Combustion CHAPTER III OBJECTIVES CHAPTER IV THE EXPERIMENTAL APPARATUS 4. 1 General Facility Layout 4. 2 Air Flow System 4. 3 Bed Chamber 4. 4 Fuel Feed System 1V V1 1X 12 14 19 21 21 23 25 25 TABLE... on the combustor performance. In the present research work, literature review is carried out on combustion and gasification of feedlot manure results (chapter II). Chapter III lists out the objectives and the tasks of this research work. The experimental setup...

Madan, Ajit M.

2012-06-07T23:59:59.000Z

423

Hydraulically refueled battery employing a packed bed metal particle electrode  

DOE Patents (OSTI)

A secondary zinc air cell, or another selected metal air cell, employing a spouted/packed metal particle bed and an air electrode is described. More specifically, two embodiments of a cell, one that is capable of being hydraulically recharged, and a second that is capable of being either hydraulically or electrically recharged. Additionally, each cell includes a sloped bottom portion to cause stirring of the electrolyte/metal particulate slurry when the cell is being hydraulically emptied and refilled during hydraulically recharging of the cell. 15 figs.

Siu, S.C.; Evans, J.W.

1998-12-15T23:59:59.000Z

424

Smart Grid: Network simulator for smart grid test-bed  

Science Journals Connector (OSTI)

Smart Grid become more popular, a smaller scale of smart grid test-bed is set up at UNITEN to investigate the performance and to find out future enhancement of smart grid in Malaysia. The fundamental requirement in this project is design a network with low delay, no packet drop and with high data rate. Different type of traffic has its own characteristic and is suitable for different type of network and requirement. However no one understands the natural of traffic in smart grid. This paper presents the comparison between different types of traffic to find out the most suitable traffic for the optimal network performance.

L C Lai; H S Ong; Y X Che; N Q Do; X J Ong

2013-01-01T23:59:59.000Z

425

Evaluation and selection of circulating fluidized bed boilers  

SciTech Connect

The use of circulating fluidized bed (CFB) boilers to generate steam on an industrial scale is increasing. The reasons for this growth include high combustion efficiency, fuel flexibility, and inherent emissions control capability, particularly with regards to control of nitrogen oxides (NO{sub x}) and sulfur oxides (SO{sub x}). However, CFB boiler technology is unique, with operating performance, and construction features that differ significantly from those used in conventional pulverized coal (PC) and stoker-fired boiler technology. An overview of these features is presented by the author.

Marcinek, F.T. (Charles B. Tibbits and Associates, Seattle, WA (US))

1989-05-01T23:59:59.000Z

426

The SEI facility for fluid-bed wood gasification  

SciTech Connect

In mid 1985, construction was begun on the world's largest fluidized bed, wood gasification plant at the clay processing plant in Quincy, Fla. In March 1986, the plant was purchased by Southern Electric International (SEI). This paper describes how SEI coordinated the redesign of many of the plant systems and supervised the completion of construction and startup. In late 1986, the gasifier plant was sold. SEI remains involved as the operations and maintenance contractor on-site and is now responsible for design changes and equipment maintenance.

Bullpitt, W.S.; Rittenhouse, O.C. (Southern Electric International, Inc. North Atlanta, GA (US)); Masterson, L.D. (Southern Electric International Quincy, FL (US))

1989-09-01T23:59:59.000Z

427

Packed bed carburization of tantalum and tantalum alloy  

DOE Patents (OSTI)

Packed bed carburization of a tantalum or tantalum alloy object is disclosed. A method for producing corrosion-resistant tantalum or tantalum alloy objects is described. The method includes the steps of placing the object in contact with a carburizing pack, heating the packed object in vacuum furnace to a temperature whereby carbon from the pack diffuses into the object forming grains with tantalum carbide along the grain boundaries, and etching the surface of the carburized object. This latter step removes tantalum carbides from the surface of the carburized tantalum object while leaving the tantalum carbide along the grain boundaries. 4 figs.

Lopez, P.C.; Rodriguez, P.J.; Pereyra, R.A.

1999-06-29T23:59:59.000Z

428

Analysis of stream bed sediments of Four Mile Creek  

SciTech Connect

Until 1988, solutions containing nitric acid, odium hydroxide, low levels of radionuclides (mostly tritiated water) and some metals were discharged to unlined seepage basins at the F and H Areas of the Savannah River Site (SRS) as part of normal operations. The basins are now being closed according to the Resource Conservation and Recovery Act (RCA). As part of the closure, a Part B Post-Closure Care Permit is being prepared. The Part B permit requires information on contaminant concentrations in stream bed sediments in the adjacent Four Mile Creek, which are reported herein. 5 refs., 1 fig., 2 tabs.

Haselow, J.S.

1990-08-13T23:59:59.000Z

429

E-Print Network 3.0 - avr pebble bed Sample Search Results  

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

of the lithium ceramics pebble beds... have a significant impact on the temperature profile of the Helium Cooled Pebble ... Source: Abdou, Mohamed - Fusion Science and...

430

Numerical and experimental study of hydrodynamics in a compartmented fluidized bed oil palm shell biomass gasifier.  

E-Print Network (OSTI)

??Numerical and experimental studies of hydrodynamic parameters of fluidized beds formed by either a single component system or a binary mixture in a pilot plant… (more)

Wee, Siaw Khur

2011-01-01T23:59:59.000Z

431

E-Print Network 3.0 - autologous microcirculatory beds Sample...  

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

S. Popel, Marcos Intaglietta and Paul C. Johnson Summary: and after dextran infusion as with the FCD determinations. A manual map of the microcirculatory bed guided... ,...

432

E-Print Network 3.0 - assisted packed bed Sample Search Results  

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

WASTES Summary: consolidation of the solid refuse bed took place as a result of gasification. The bulk density of the hand-packed... involving acidic bio leachate production...

433

Microsoft Word - Wireless Test Bed named NUF_INL version.doc  

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

Department of Energy Designates the Wireless Test Bed as a National User Facility IDAHO FALLS - The U.S. Department of Energy (DOE) recently designated Idaho National...

434

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

435

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

SciTech Connect

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

436

Final Report on Utilization of TRU TRISO Fuel as Applied to HTR Systems Part I: Pebble Bed Reactors  

SciTech Connect

The Deep-Burn (DB) concept [ ] focuses on the destruction of transuranic nuclides from used light water reactor (LWR) fuel. These transuranic nuclides are incorporated into tri-isotopic (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 (FY) (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 239Pu, 240Pu, and 241Pu 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. Regarding the coated particle performance, the FY 2009 investigations showed that no significant failure is to be expected for the reference fuel particle during normal operation. It was found, however, that the sensitivity of the coating stress to the CO production in the kernel was large. The CO production is expected to be higher in DB fuel than in UO2 fuel, but its exact level has a high uncertainty. Furthermore, in the fuel performance analysis transient conditions were not yet taken into account. 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 transuranic [TRU] content and high burn-up). Accomplishments of this work include: •Core analysis of a HTR-MODULE design loaded with Deep-Burn fuel. •Core analysis of a HTR-MODULE design loaded with Deep-Burn fuel and Uranium. •Core analysis of a HTR-MODULE design loaded with Deep-Burn fuel and Modified Open Cycle Components. •Core analysis of a HTR-MODULE design loaded with Deep-Burn fuel and Americium targets.

Brian Boer; Abderrafi M. Ougouag

2011-03-01T23:59:59.000Z

437

DEVELOPMENT OF COAL BED METHANE UTILIZING GIS TECHNOLOGIES  

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 were the advancements in Geographical Information Systems (GIS) technologies generating terra-bytes of new data for the oil and gas industry. Coupled to these accelerating initiatives are many environmental concerns relating to production wastes and water table depletion of fresh water resources. It is these concerns that prompted a vital need within the industry for the development of Best Management Practices (BMPs) and mitigation strategies utilizing GIS technologies for efficient environmental protection in conjunction with effective production of CBM. This was accomplished by developing a framework to take advantage of a combination of investigative field research joined with leading edge GIS technologies for the creation of environmentally characterized regions of study. Once evaluated these regions had BMP's developed to address their unique situations for Coal Bed Methane production and environmental protection. Results of the project will be used to support the MBOGC's Programmatic Environmental Impact Statement as required by the Montana Environmental Policy Act (MEPA) and by the BLM for NEPA related issues for acreage having federally owned minerals.

J. Daniel Arthur

2003-04-01T23:59:59.000Z

438

Fluidized-bed retrofit a practical alternative to FGD  

SciTech Connect

When SO/sub 2/ emissions from an existing utility boiler must be reduced, retrofitting for fluidized-bed combustion may be an attractive alternative. In addition to reducing atmospheric pollutants during combustion, FBC retrofits allow simultaneous burning of a wide range of low-cost fuels. Also, since new components are incorporated in the steam generator rather than added on as pollution-control equipment, they extend the use of the plant beyond its normal life expectancy. There are five types of fossil-fuel-fired boilers used by utilities (pulverized coal, cyclone, stoker, oil, and gas), and literally hundreds of designs. Not all of these designs lend themselves to FBC retrofit, and much depends on the size and age of the boiler. Units that are not structurally sound or that have extensive internal corrosion are generally not suitable. Boilers over 150 MW usually have complicated water circuitry and small furnace plan areas, and may not have enough space to accommodate the fluidized bed. Other important considerations are: Water/steam-circulation design, Furnace bottom-to-grade clearance, Air-heater type and arrangement, Boiler support, Type of particulate-control device, Fan capacity, Space available in the boiler island for alterations.

Stringfellow, T.E.; Nolte, F.S.; Sage, W.L.

1984-02-01T23:59:59.000Z

439

Polarized seismic and solitary waves run-up at the sea bed  

SciTech Connect

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

440

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

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441

CONSEQUENCES OF CLIMATE CHANGE FOR NATIVE PLANTS AND  

E-Print Network (OSTI)

occurrences with observed historical climate, then project this correlation onto scenarios of climate change meter) climatology. Results from this study show that projected future distributions of climates CONSEQUENCES OF CLIMATE CHANGE FOR NATIVE PLANTS AND CONSERVATION A White Paper from

442

U.S. Ethanol Policy: The Unintended Consequences  

E-Print Network (OSTI)

the future growth, but reasonable production costs remain elusive. The unintended consequences of the policy, especially those influencing world food prices, are negative and far outweigh the positives. Corn-based ethanol has had only small price, energy...

Griffin, James M.; Soto, Maricio Cifuentes

443

Consequences of Fault Currents Contributed by Distributed Generation  

E-Print Network (OSTI)

Consequences of Fault Currents Contributed by Distributed Generation Intermediate Project Report Currents Contributed by Distributed Generation Intermediate Report for the Project "New Implications in systems with distributed generation. The main concept described is that fault current throughout power

444

Truths and Consequences Sprint All-Day Sprint  

E-Print Network (OSTI)

Truths and Consequences Sprint All-Day Sprint Math Meet 2007 College of Charleston Part I: Each with the truth values of these statements. Your job is to put a check in the box next to those statements

Mitchener, W. Garrett

445

The Latest Unanticipated Consequence in the Ethanol Fiasco  

E-Print Network (OSTI)

Until recently, the 2007 ethanol mandates have been a story of very small environmental and security benefits and large, unexpected increases in food prices as corn was diverted from food to fuel uses. Now we have another unforeseen consequence...

Griffin, James M.

446

Co-Simulation of Building Energy and Control Systems with the Building Controls Virtual Test Bed  

SciTech Connect

This article describes the implementation of the Building Controls Virtual Test Bed (BCVTB). The BCVTB is a software environment that allows connecting different simulation programs to exchange data during the time integration, and that allows conducting hardware in the loop simulation. The software architecture is a modular design based on Ptolemy II, a software environment for design and analysis of heterogeneous systems. Ptolemy II provides a graphical model building environment, synchronizes the exchanged data and visualizes the system evolution during run-time. The BCVTB provides additions to Ptolemy II that allow the run-time coupling of different simulation programs for data exchange, including EnergyPlus, MATLAB, Simulink and the Modelica modelling and simulation environment Dymola. The additions also allow executing system commands, such as a script that executes a Radiance simulation. In this article, the software architecture is presented and the mathematical model used to implement the co-simulation is discussed. The simulation program interface that the BCVTB provides is explained. The article concludes by presenting applications in which different state of the art simulation programs are linked for run-time data exchange. This link allows the use of the simulation program that is best suited for the particular problem to model building heat transfer, HVAC system dynamics and control algorithms, and to compute a solution to the coupled problem using co-simulation.

Wetter, Michael

2010-08-22T23:59:59.000Z

447

Bedding and Within-Pen Location Effects on Feedlot Pen Runoff Quality Using a Rainfall Simulator  

E-Print Network (OSTI)

and 1999. Bedding had a significant (P # 0.05) effect on NH4­N concentration and load in 1999, SO4 load in 1998, SO4 concentration and load in 1999, and total coliforms in both years; where these three reactive phosphorus (DRP), total P, and NH4­N concentrations and loads at the bedding pack location in wood

Selinger, Brent

448

Using Ilmenite To Reduce the Tar Yield in a Dual Fluidized Bed Gasification System  

Science Journals Connector (OSTI)

In this work, ilmenite was used as the catalytic material in the Chalmers 2–4 MWth dual fluidized bed gasifier to decrease the yield of tar. ... Indirect gasification, using the Dual Fluidized Bed (DFB) concept, has been identified as being suitable for medium- to large-scale production units. ... catalytic reactors, the implementation of specific reaction media such as supercrit. ...

Anton Larsson; Mikael Israelsson; Fredrik Lind; Martin Seemann; Henrik Thunman

2014-03-10T23:59:59.000Z

449

EXPERIMENTAL & NUMERICAL STUDY OF CERAMIC BREEDER PEBBLE BED THERMAL DEFORMATION BEHAVIOR  

E-Print Network (OSTI)

EXPERIMENTAL & NUMERICAL STUDY OF CERAMIC BREEDER PEBBLE BED THERMAL DEFORMATION BEHAVIOR Zhiyong involved in ceramic breeder pebble bed thermal deformation are complex. First, unlike solid material.25 and 0.63 mm) at temperatures of 700-800ºC. The experimental results show that the thermal deformation

Abdou, Mohamed

450

Design and Development of a Low-Cost Test-Bed for Undergraduate Education in UAVs  

E-Print Network (OSTI)

Design and Development of a Low-Cost Test-Bed for Undergraduate Education in UAVs D. Jung, E. J for the development of a low-cost Unmanned Aerial Vehicle (UAV) test-bed for educational purposes. The objective) and graduate students (secondarily) in UAV research. The complete design and development of all hardware

Tsiotras, Panagiotis

451

Inactivation of Salmonella Enteritidis PT 30 on Almonds with a Fluidized Bed Atmospheric Pressure Plasma  

E-Print Network (OSTI)

investigated the use of a fluidized bed atmospheric pressure plasma (APP) as a possible pasteurization methodInactivation of Salmonella Enteritidis PT 30 on Almonds with a Fluidized Bed Atmospheric Pressure Plasma Kalyani Narayanan1, Nathan M. Anderson2, Gregory J. Fleischman2 and Susanne Keller2 1Institute

Heller, Barbara

452

Influence of bed materials on methanogenic characteristics and immobilized microbes in anaerobic digester  

Science Journals Connector (OSTI)

This paper reports and discusses the effects of bed materials on the performance of methanogenic fluidized bed reactors with acetic acid as the sole organic substrate. Four bed materials (carbon filter, rock wool, loofah sponge and polyurethane foam) were evaluated and compared for their methanogenic characteristics and immobilized microbes. The present results indicated that the characteristics of the bed materials for immobilization had a significant influence on the methane production. The loofah sponge and polyurethane foam were suggested to be suitable for the bed material in anaerobic digestion. The best methane yield was obtained from the loofah reactor among the four kinds of bed materials. The main cellular morphologies present in the biofilms of the four different materials on the colonization were observed using scanning electron microscopy. The microphotographs indicated that the biofilm was primarily composed of coccus, diplococci-shaped Methanosarcina-like cells, long rods of Methanobacterium and coccobacillus of Methanobrevibacter-like bacteria. The morphologies observed from the microscopic analysis indicated that the different bed materials could provide specific conditions for the adherence of distinct microorganism types. Furthermore, a 16S rRNA phylogenetic analysis was conducted to compare the immobilized archaeal population. The results of the 16S rRNA phylogenetic analysis indicated that the major immobilized methanogens were Methanobacterium formicicum, Methanosarcina barkeri and Methanosarcina mazei in all the bed materials. A similar clone distribution was observed with the loofah sponge and the carbon felt.

Yingnan Yang; Chika Tada; Md Shohidullah Miah; Kenichiro Tsukahara; Tatsuo Yagishita; Shigeki Sawayama

2004-01-01T23:59:59.000Z

453

Tar Reduction by Primary Measures in an Autothermal Air-Blown Fluidized Bed Biomass Gasifier  

Science Journals Connector (OSTI)

mean size (?m) ... When some calcined dolomite (CaO·MgO) is used in the bed of a biomass gasifier of fluidized bed type the raw gas produced is cleaner than when only silica sand is used in it as fluidizing medium. ...

Manuel Campoy; Alberto Go?mez-Barea; Diego Fuentes-Cano; Pedro Ollero

2010-10-01T23:59:59.000Z

454

Fast Kinetics of Fe2+ Oxidation in Packed-Bed Reactors  

Science Journals Connector (OSTI)

...protein/ml liquid vol of reactor YPlS Yield of product...material was also used for analysis of the total protein...of the packed-bed reactors. Several experimen...effect. The system reliability was evalu- ated with...ion-exchange resin packed-bed reactor by switching the inlet...

Sergei I. Grishin; Olli H. Tuovinen

1988-12-01T23:59:59.000Z

455

Pulsed atmospheric fluidized bed combustion. Technical progress report, April 1992--June 1992  

SciTech Connect

The general specifications for a Pulsed Atmospheric Fluidized Bed Combustor Design Report (PAFBC) plant are presented. The design tasks for the PAFBC are described in the following areas: Coal/Limestone preparation and feed system; pulse combustor; fluidized bed; boiler parts; and ash handling system.

Not Available

1992-08-01T23:59:59.000Z

456

Sludge drying reed beds: a full and pilot-scales study for activated sludge treatment  

E-Print Network (OSTI)

Sludge drying reed beds: a full and pilot-scales study for activated sludge treatment S. Troesch.troesch@cemagref.fr, dirk.esser@sint.fr Abstract Sludge drying reed beds have been used for dewatering and mineralization of sludge since the beginning of the 90's, but their insufficient performances in terms of Dry Matter [DM

Paris-Sud XI, Université de

457

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

E-Print Network (OSTI)

OF A S T E A M HYDRO-GASIFIER IN A FLUIDIZED BED REACTOROF A S T E A M HYDRO-GASIFIER IN A FLUIDIZED BED REACTOR F Iis fed into a hydro-gasifier reactor. One such process was

Park, Chan Seung; Norbeck, Joseph N.

2008-01-01T23:59:59.000Z

458

Adaptive higher order numerical simulation of heat and mass transfer in fluidized beds  

E-Print Network (OSTI)

Adaptive higher order numerical simulation of heat and mass transfer in fluidized beds Ch. Nagaiah1 adaptive numerical results of heat and mass transfer in fluidized beds using higher order time stepping injection. The numerical results are tested with different time stepping methods for different spatial grid

Magdeburg, Universität

459

Determining the economic consequences of natural gas substitution  

Science Journals Connector (OSTI)

Abstract Resource depletion is a key aspect of sustainability, because the consumption of finite resources impacts on their availability for future generations. There are many proposed methods for accounting for the depletion of a particular resource, amongst which include the proportion of the resource depleted, the rate of resource depletion, and the energy, exergy, or monetary cost of extraction as the resource becomes harder to find or extract. This paper is part of a wider study to measure resource depletion using its environmental and economic impacts for the case of natural gas, where depletion of natural gas requires substitution by black coal or coal seam gas. The capital and operating costs are estimated both for upstream fuel extraction and purification and downstream use of the fuel to produce electricity, hydrogen and ammonia. These costs are based on a commercial scale of operation, using the same basis for economic modelling in each case. Black coal was found to have the lowest transfer price from upstream to downstream processing among the three feedstocks, but the highest capital and operating costs in the downstream processes. Conventional gas produced slightly higher transfer prices and downstream processing costs compared to coal seam gas. The favourable economic and environmental indicators for natural gas and coal seam gas are expected to lead to increased demand for these resources over coal, running the risk of a gas shortage. The economic consequence of a scarcity of either gas resource will be a penalty in capital and operating costs to produce the three products should gas be substituted with black coal.

Shaun Rimos; Andrew F.A. Hoadley; David J. Brennan

2014-01-01T23:59:59.000Z

460

Gas temperature profiles at different flow rates and heating rates suffice to estimate kinetic parameters for fluidised bed combustion  

SciTech Connect

Experimental work on estimation kinetic parameters for combustion was conducted in a bench-scale fluidised bed (FB: 105x200mm). Combustion medium was obtained by using an electrical heater immersed into the bed. The ratio of heating rate (kJ/s) to molar flow rate of air (mol/s) regulated by a rheostat so that the heat of combustion (kJ/mol) can be synthetically obtained by an electrical power supply for relevant O{sub 2}-feedstock concentration (C{sub 0}). O{sub 2}-restriction ratio ({beta}) was defined by the ratio of O{sub 2}-feedstock concentration to O{sub 2}-air concentration (C{sub O{sub 2}-AIR}) at prevailing heating rates. Compressed air at further atmospheric pressure ({approx_equal}102.7kPa) entered the bed that was alumina particles (250{mu}m). Experiments were carried out at different gas flow rates and heating rates. FB was operated with a single charge of (1300g) particles for obtaining the T/T{sub 0} curves, and than C/C{sub 0} curves. The mathematical relationships between temperature (T) and conversion ratio (X) were expressed by combining total energy balance and mass balance in FB. Observed surface reaction rate constants (k{sub S}) was obtained from the combined balances and proposed model was also tested for these kinetic parameters (frequency factor: k{sub 0}, activation energy: E{sub A}, and reaction order: n) obtained from air temperature measurements. It was found that the model curves allow a good description of the experimental data. Thus, reaction rate for combustion was sufficiently expressed. (author)

Suyadal, Y. [Faculty of Engineering, Department of Chemical Engineering, Ankara University, 06100-Tandogan, Ankara (Turkey)

2006-07-15T23:59:59.000Z

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461

The Milky Way's dark matter distribution and consequences for axion detection  

SciTech Connect

Signals for both direct and indirect dark matter detection depend on the phase-space distribution of dark matter. The possibility of structures with high physical density, known as caustics, has provided an opportunity to increase the discovery potential of the Axion Dark Matter eXperiment (ADMX). I discuss the formation of dark matter caustics and consequences of the caustic ring model for ADMX.

Duffy, Leanne D [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

462

User converts gas boiler to fluidized bed to save $1. 5M  

SciTech Connect

Retrofitting a fluidized bed combustion (FBC) system may allow Clayton Foods Inc. to reduce its annual fuel bill by $1.5 million when the system comes on line in 1986. The system will burn low-grade, high-sulfur coal instead of natural gas, and should pay back the $4.1 million investment in under five years. The dual bed design separates the chemical processes of combustion and desulfurization into two chambers, which allows smaller-sized combustors that achieve high efficiencies in less time than conventional, single-bed fluidized bed boilers. Possible limitations prevent other manufacturers from making the dual-bed system. The Wormser unit is the only retrofit application of this technology in an industrial setting.

Springer, N.

1985-07-29T23:59:59.000Z

463

Probabilistic accident consequence uncertainty analysis -- Early health effects uncertainty 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 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

464

Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for internal dosimetry. 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 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

465

The design of a fluidized bed for testing of a robotic burrowing device which mimics razor clams  

E-Print Network (OSTI)

This thesis reviews the design of a fluidized bed test setup for testing digging kinematics of RoboClam, a burrowing device based on Atlantic Razor Clams. This test bed allows for in-lab testing in an environment covered ...

Dorsch, Daniel Scott

2012-01-01T23:59:59.000Z

466

Determination of prescription dose for Cs-131 permanent implants using the BED formalism including resensitization correction  

SciTech Connect

Purpose: The current widely used biological equivalent dose (BED) formalism for permanent implants is based on the linear-quadratic model that includes cell repair and repopulation but not resensitization (redistribution and reoxygenation). The authors propose a BED formalism that includes all the four biological effects (4Rs), and the authors propose how it can be used to calculate appropriate prescription doses for permanent implants with Cs-131. Methods: A resensitization correction was added to the BED calculation for permanent implants to account for 4Rs. Using the same BED, the prescription doses with Au-198, I-125, and Pd-103 were converted to the isoeffective Cs-131 prescription doses. The conversion factor F, ratio of the Cs-131 dose to the equivalent dose with the other reference isotope (F{sub r}: with resensitization, F{sub n}: without resensitization), was thus derived and used for actual prescription. Different values of biological parameters such as ?, ?, and relative biological effectiveness for different types of tumors were used for the calculation. Results: Prescription doses with I-125, Pd-103, and Au-198 ranging from 10 to 160 Gy were converted into prescription doses with Cs-131. The difference in dose conversion factors with (F{sub r}) and without (F{sub n}) resensitization was significant but varied with different isotopes and different types of tumors. The conversion factors also varied with different doses. For I-125, the average values of F{sub r}/F{sub n} were 0.51/0.46, for fast growing tumors, and 0.88/0.77 for slow growing tumors. For Pd-103, the average values of F{sub r}/F{sub n} were 1.25/1.15 for fast growing tumors, and 1.28/1.22 for slow growing tumors. For Au-198, the average values of F{sub r}/F{sub n} were 1.08/1.25 for fast growing tumors, and 1.00/1.06 for slow growing tumors. Using the biological parameters for the HeLa/C4-I cells, the averaged value of F{sub r} was 1.07/1.11 (rounded to 1.1), and the averaged value of F{sub n} was 1.75/1.18. F{sub r} of 1.1 has been applied to gynecological cancer implants with expected acute reactions and outcomes as expected based on extensive experience with permanent implants. The calculation also gave the average Cs-131 dose of 126 Gy converted from the I-125 dose of 144 Gy for prostate implants. Conclusions: Inclusion of an allowance for resensitization led to significant dose corrections for Cs-131 permanent implants, and should be applied to prescription dose calculation. The adjustment of the Cs-131 prescription doses with resensitization correction for gynecological permanent implants was consistent with clinical experience and observations. However, the Cs-131 prescription doses converted from other implant doses can be further adjusted based on new experimental results, clinical observations, and clinical outcomes.

Luo, Wei, E-mail: wei.luo@uky.edu; Molloy, Janelle; Aryal, Prakash; Feddock, Jonathan; Randall, Marcus [Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky 40536 (United States)] [Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky 40536 (United States)

2014-02-15T23:59:59.000Z

467

Down-flow moving-bed gasifier with catalyst recycle  

DOE Patents (OSTI)

The gasification of coal and other carbonaceous materials by an endothermic gasification reaction is achieved in the presence of a catalyst in a down-flow, moving-bed gasifier. Catalyst is removed along with ash from the gasifier and is then sufficiently heated in a riser/burner by the combustion of residual carbon in the ash to volatilize the catalyst. This volatilized catalyst is returned to the gasifier where it uniformly contacts and condenses on the carbonaceous material. Also, the hot gaseous combustion products resulting from the combustion of the carbon in the ash along with excess air are introduced into the gasifier for providing heat energy used in the endothermic reaction. 1 fig.

Halow, J.S.

1999-04-20T23:59:59.000Z

468

Thermal conductivity of Permian Basin bedded salt at elevated pressure  

SciTech Connect

Measurements of thermal conductivity were made on five core samples of bedded rock salt from the Permian Basin in Texas. The sample size was 100 mm in diameter by 250 mm in length. Measurements were conducted under confining pressures ranging from 3.8 to 31.0 MPa and temperatures from room temperature to 473 K. Conductivity showed no dependence on confining pressure, but showed a monotonic, negative temperature dependence. Four of the five samples showed conductivities clustered in a range of 5.6 +- 0.5 W/m.K at room temperature, falling to 3.6 +- 0.3 W/m.K at 473 K. These values are approximately 20% below the values for pure halite, reflecting perhaps the 5 to 20% non-halite component of the samples. The fifth sample showed a conductivity vs temperature dependence much like that of halite. 19 references, 4 figures.

Durham, W.B.; Boro, C.O.; Beiriger, J.M.

1984-04-01T23:59:59.000Z

469

Down-flow moving-bed gasifier with catalyst recycle  

DOE Patents (OSTI)

The gasification of coal and other carbonaceous materials by an endothermic gasification reaction is achieved in the presence of a catalyst in a down-flow, moving-bed gasifier. Catalyst is removed along with ash from the gasifier and is then sufficiently heated in a riser/burner by the combustion of residual carbon in the ash to volatilize the catalyst. This volatilized catalyst is returned to the gasifier where it uniformly contacts and condenses on the carbonaceous material. Also, the hot gaseous combustion products resulting from the combustion of the carbon in the ash along with excess air are introduced into the gasifier for providing heat energy used in the endothermic reaction.

Halow, John S. (Waynesburg, PA)

1999-01-01T23:59:59.000Z

470

Development of second-generation pressurized fluidized bed combustion process  

SciTech Connect

Under the sponsorship of the United States Department of Energy, Foster Wheeler Development Corporation, and its team members, Westinghouse, Gilbert/Commonwealth, and the Institute of Gas Technology are developing second-generation pressurized fluidized bed combustion technology capable of achieving net plant efficiency in excess of 45 percent based on the higher heating value of the coal. A three-phase program entails design and costing of a 500 MWe power plant and identification of developments needed to commercialize this technology (Phase 1), testing of individual components (Phase 2), and finally testing these components in an integrated mode (Phase 3). This paper briefly describes the results of the first two phases as well as the progress on the third phase. Since other projects which use the same technology are in construction or in negotiation stages -- namely, the Power System Development Facility and the Four Rivers Energy Modernization Projects -- brief descriptions of these are also included.

Wolowodiuk, W.; Robertson, A. [Foster Wheeler Development Corp., Livingston, NJ (United States); Bonk, D. [USDOE Morgantown Energy Technology Center, WV (United States)

1994-10-01T23:59:59.000Z

471

METAL FILTERS FOR PRESSURIZED FLUID BED COMBUSTION (PFBC) APPLICATIONS  

SciTech Connect

Advanced coal and biomass-based gas turbine power generation technologies (IGCC, PFBC, PCFBC, and Hipps) are currently under development and demonstration. Efforts at the Siemens Westinghouse Power Corporation (SWPC) have been focused on the development and demonstration of hot gas filter systems as an enabling technology for power generation. As part of the demonstration effort, SWPC has been actively involved in the development of advanced filter materials and component configuration, has participated in numerous surveillance programs characterizing the material properties and microstructure of field-tested filter elements, and has undertaken extended, accelerated filter life testing programs. This report reviews SWPC's material and component assessment efforts, identifying the performance, stability, and life of porous commercial metal, advanced alloy, and intermetallic filters under simulated, pressurized fluidized-bed combustion (PFBC) conditions.

M.A. Alvin

2004-01-02T23:59:59.000Z

472

Phase 1 Methyl Iodide Deep-Bed Adsorption Tests  

SciTech Connect

Nuclear fission results in the production of fission products (FPs) and activation products including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Research, demonstrations, and some reprocessing plant experience have indicated that diatomic iodine can be captured with efficiencies high enough to meet regulatory requirements. Research on the capture of organic iodides has also been performed, but to a lesser extent [Jubin 2012b]. Several questions remain open regarding the capture of iodine bound in organic compounds. Deep-bed methyl iodide adsorption testing has progressed according to a multi-laboratory methyl iodide adsorption test plan. This report summarizes the first phase of methyl iodide adsorption work performed according to this test plan using the deep-bed iodine adsorption test system at the Idaho National Laboratory (INL), performed during Fiscal Year (FY) 2013 and early FY-2014. Testing has been performed to address questions posed in the test plan, and followed the testing outline in the test plan. Tests established detection limits, developed procedures for sample analysis with minimal analytical interferences, and confirmed earlier results that show that the methyl iodide reacts when in contact with the AgZ sorbent, and not significantly in the gas flow upstream of the sorbent. The reaction(s) enable separation of the iodine from the organic moiety, so that the iodine can chemisorb onto the sorbent. The organic moiety can form other compounds, some of which are organic compounds that are detected and can be tentatively identified using GC-FID and GCMS. Test results also show that other gas constituents (NOx and/or H2O) can affect the methyl iodide reactions. With NOx and H2O present in the gas stream, the majority of uncaptured iodine exiting iodine-laden sorbent beds is in the form of I2 or HI, species that are soluble in NaOH scrubbing solution for iodine analysis. But when NOx and H2O are not present, then the majority of the uncaptured iodine exiting iodine-laden sorbent is in the form of methyl iodide. Methyl iodide adsorption efficiencies have been high enough so that initial DFs exceed 1,000 to 10,000. The methyl iodide mass transfer zone depths are estimated at 4-8 inches, possibly deeper than mass transfer zone depths estimated for I2 adsorption on AgZ. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption under various conditions specified in the methyl iodide test plan, and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.

Nick Soelberg; Tony Watson

2014-08-01T23:59:59.000Z

473

Proliferation resistant fuel for pebble bed modular reactors  

SciTech Connect

We show that it is possible to denature the Plutonium produced in Pebble Bed Modular Reactors (PBMR) by doping the nuclear fuel with either 3050 ppm of {sup 237}Np or 2100 ppm of Am vector. A correct choice of these isotopes concentration yields denatured Plutonium with isotopic ratio {sup 238}Pu/Pu {>=} 6%, for the entire fuel burnup cycle. The penalty for introducing these isotopes into the nuclear fuel is a subsequent shortening of the fuel burnup cycle, with respect to a non-doped reference fuel, by 41.2 Full Power Days (FPDs) and 19.9 FPDs, respectively, which correspond to 4070 MWd/ton and 1965 MWd/ton reduction in fuel discharge burnup. (authors)

Ronen, Y.; Aboudy, M.; Regev, D.; Gilad, E. [Dept. of Nuclear Engineering, Ben-Gurion Univ. of the Negev, Beer-Sheva 84105 (Israel)

2012-07-01T23:59:59.000Z

474

Trace element behavior in the fluidized bed gasification of solid recovered fuels – A thermodynamic study  

Science Journals Connector (OSTI)

Gasification of biomass and recycled fuels is of particular interest for the efficient production of power and heat. Trace elements present as impurities in the pro