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1

Property:TimePeriod | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revisionEnvReviewNonInvasiveExploration JumpSanyalTempWellhead Jump to:Technology ReadinessTimePeriod Jump to:

2

Technical Note Solution of periodic heating problems by the  

E-Print Network [OSTI]

.R. Barber * Department of Mechanical Engineering, 2250 GG Brown Laboratory, University of Michigan, Ann in sliding solids [2], regenerative heat exchangers [3], solar heating systems [4] and heat con- duction

Barber, James R.

3

TIME-PERIODIC SOUND WAVE PROPAGATION COMPRESSIBLE EULER EQUATIONS  

E-Print Network [OSTI]

A PARADIGM FOR TIME-PERIODIC SOUND WAVE PROPAGATION IN THE COMPRESSIBLE EULER EQUATIONS BLAKE consistent with time-periodic sound wave propagation in the 3 Ã? 3 nonlinear compressible Euler equations description of shock-free waves that propagate through an oscillating entropy field without breaking or dis

4

Combined Heat and Power: A Technology Whose Time Has Come  

E-Print Network [OSTI]

Incentives for Combined Heat and Power, U.S. E NVTL . PCombined Heat and Power: A Technology Whose Time Has ComeWashington, D.C. COMBINED HEAT AND POWER A. Create an

Ferraina, Steven

2014-01-01T23:59:59.000Z

5

Controlling mobility via rapidly oscillating time-periodic stimulus  

E-Print Network [OSTI]

To address the dynamics of a Brownian particle on a periodic symmetric substrate under high-frequency periodic forcing with a vanishing time average, we construct an effective Langevin dynamics by invoking Kapitza-Landau time window. Our result is then exploited to simulate the mobility both for original and effective dynamics which are in good agreement with theoretical predictions. This close agreement and the enhancement of mobility are very robust against the tailoring of amplitude-to-frequency ratio which substantiates the correctness of our calculation. Present results may be illuminating for understanding the dynamics of cold atoms in electromagnetic fields.

Prasun Sarkar; Alok Kumar Maity; Anindita Shit; Sudip Chattopadhyay; Jyotipratim Ray Chaudhuri; Suman K Banik

2014-03-26T23:59:59.000Z

6

On the Surface Heating of Synchronously-Spinning Short-Period Jovian Planets  

E-Print Network [OSTI]

We consider the atmospheric flow on short-period extra-solar planets through two-dimensional numerical simulations of hydrodynamics with radiation transfer. One side is always exposed to the irradiation from the host star. The other is always in shadow. The temperature of the day side is determined by the equilibrium which the planetary atmosphere establishes with stellar radiation. Part of the thermal energy deposited on the day side is advected to the night side by a current. The radiation transfer, the night-side temperature distribution and by this the spectroscopic signature of the planet are sensitive functions of the atmospheric opacity. If the atmosphere contains grains with an abundanceand size distribution comparable to that of the interstellar medium, shallow heating occurs on the day side and the night side cools well below the day side. The temperature difference decreases as the abundance of grains is reduced. A simple analytic model of the dissipation of the circulation flow and associated kinetic heating is considered. This heating effect occurs mostly near the photosphere, not deep enough to significantly affect the size of planets. We show that the surface irradiation suppresses convection near the photospheric region on the day side. In some cases convection zones appear near the surface on the night side. This structural modification may influence the response and dissipation of tidal disturbances and alter the circularization and synchronization time scales.

Andreas Burkert; Douglas Lin; Peter Bodenheimer; Chris Jones; Harold Yorke

2003-12-18T23:59:59.000Z

7

Particle energization through time-periodic helical magnetic fields  

E-Print Network [OSTI]

We solve for the motion of charged particles in a helical time-periodic ABC (Arnold-Beltrami-Childress) magnetic field. The magnetic field lines of a stationary ABC field with coefficients A=B=C=1 are chaotic, and we show ...

Mitra, Dhrubaditya

8

Time-periodic solutions of the Benjamin-Ono equation  

SciTech Connect (OSTI)

We present a spectrally accurate numerical method for finding non-trivial time-periodic solutions of non-linear partial differential equations. The method is based on minimizing a functional (of the initial condition and the period) that is positive unless the solution is periodic, in which case it is zero. We solve an adjoint PDE to compute the gradient of this functional with respect to the initial condition. We include additional terms in the functional to specify the free parameters, which, in the case of the Benjamin-Ono equation, are the mean, a spatial phase, a temporal phase and the real part of one of the Fourier modes at t = 0. We use our method to study global paths of non-trivial time-periodic solutions connecting stationary and traveling waves of the Benjamin-Ono equation. As a starting guess for each path, we compute periodic solutions of the linearized problem by solving an infinite dimensional eigenvalue problem in closed form. We then use our numerical method to continue these solutions beyond the realm of linear theory until another traveling wave is reached (or until the solution blows up). By experimentation with data fitting, we identify the analytical form of the solutions on the path connecting the one-hump stationary solution to the two-hump traveling wave. We then derive exact formulas for these solutions by explicitly solving the system of ODE's governing the evolution of solitons using the ansatz suggested by the numerical simulations.

Ambrose , D.M.; Wilkening, Jon

2008-04-01T23:59:59.000Z

9

A Computational Analysis of Smart Timing Decisions for Heating Based on an Air-to-Water Heat pump SMARTER EUROPE E-world energy & water 2014 Proceedings page 1  

E-Print Network [OSTI]

A Computational Analysis of Smart Timing Decisions for Heating Based on an Air-to-Water Heat pump Decisions for Heating Based on an Air-to-Water Heat pump Jan Treur VU University Amsterdam, Agent Systems be most efficient to use this energy in these periods. For air to water heat pumps a similar issue occurs

Treur, Jan

10

Tables for solution of the heat-conduction equation with a time-dependent heating rate  

E-Print Network [OSTI]

Tables are presented for the solution of the transient onedimensional heat flow in a solid body of constant material properties with the heating rate at one boundary dependent on time. These tables allow convenient and ...

Bergles A. E.

1962-01-01T23:59:59.000Z

11

Combined Heat and Power: A Technology Whose Time Has Come  

E-Print Network [OSTI]

energy efficient and environmentally friendly technology.Combined Heat and Power: A Technology Whose Time Has Comesteps to utilize the technology. 9 The average increase in

Ferraina, Steven

2014-01-01T23:59:59.000Z

12

Feedback Control of the Sawtooth Period through Real Time Control of the Ion Cyclotron Resonance Frequency  

E-Print Network [OSTI]

Feedback Control of the Sawtooth Period through Real Time Control of the Ion Cyclotron Resonance Frequency

13

On-line measurement of heat of combustion. Final report, period ended 30 April 1988  

SciTech Connect (OSTI)

An experimental method for an on-line measurement of heat of combustion of a gaseous hydrocarbon fuel mixture of unknown composition is developed. It involves combustion of a test gas with a known quantity of air to achieve a predetermined oxygen concentration level in the combustion products. This is accomplished by a feedback controller which maintains the gas volumetric flow rate at a level consistent with the desired oxygen concentration in the products. The heat of combustion is determined from a known correlation with the gas volumetric flow rate. An on-line microcomputer accesses the gas volumetric flow data, and displays the heat of combustion values at desired time intervals.

Chaturvedi, S.K.; Chegini, H.

1988-07-01T23:59:59.000Z

14

Time-resolved measurement of single pulse femtosecond laser-induced periodic surface structure formation  

E-Print Network [OSTI]

Time-resolved diffraction microscopy technique has been used to observe the formation of laser-induced periodic surface structures (LIPSS) from the interaction of a single femtosecond laser pulse (pump) with a nano-scale groove mechanically formed on a single-crystal Cu substrate. The interaction dynamics (0-1200 ps) was captured by diffracting a time-delayed, frequency-doubled pulse from nascent LIPSS formation induced by the pump with an infinity-conjugate microscopy setup. The LIPSS ripples are observed to form sequentially outward from the groove edge, with the first one forming after 50 ps. A 1-D analytical model of electron heating and surface plasmon polariton (SPP) excitation induced by the interaction of incoming laser pulse with the groove edge qualitatively explains the time-evloution of LIPSS formation.

Kafka, K R P; Li, H; Yi, A; Cheng, J; Chowdhury, E A

2015-01-01T23:59:59.000Z

15

Emissions from Idling Trucks for Extended Time Periods | Department of  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat PumpRecord ofESPC ENABLE: ECMConstructionApplications |Applications |Fuels

16

Attractiveness of periodic orbits in parametrically forced systems with time-increasing friction  

E-Print Network [OSTI]

Attractiveness of periodic orbits in parametrically forced systems with time-increasing friction-dimensional systems subject to a periodic force and study numer- ically how a time-varying friction affects oscillator in the presence of friction. We find that, if the damping coefficient increases in time up

17

A FINITE ELEMENT MODEL FOR THE TIME-DEPENDENT JOULE HEATING PROBLEM*  

E-Print Network [OSTI]

.3) 0 system models the electric heating* *ial differential equation describing the electric heating of a conducting body. We prove err* *or A FINITE ELEMENT MODEL FOR THE TIME-DEPENDENT JOULE HEATING PROBLEM

Larsson, Stig

18

Short-Period Waves That Heat the Corona Detected at the 1999 Eclipse  

E-Print Network [OSTI]

As a part of a study of the cause of solar coronal heating, we searched for high-frequency (~1 Hz) intensity oscillations in coronal loops in the [Fe XIV] coronal green line. We summarize results from observations made at the 11 August 1999 total solar eclipse from Ramnicu-Valcea, Romania, through clear skies. We discuss the image reduction and analysis through two simultaneous series of coronal CCD images digitized at 10 Hz for a total time of about 140 s. One series of images was taken through a 3.6 A filter isolating the 5303 A [Fe XIV] coronal green line and the other through a 100 A filter in the nearby K-corona continuum. Previous observations, described in Pasachoff et al. (2000), showed no evidence for oscillations in the [Fe XIV] green line at a level great than 2% of coronal intensity. We describe several improvements made over the 1998 eclipse that led to increased image clarity and sensitivity. The corona was brighter in 1999 with the solar maximum, further improving the data. We use Fourier analysis to search in the [Fe XIV] channel for intensity oscillations in loops at the base of the corona. Such oscillations in the 1-Hz range are predicted as a result of density fluctuations from the resonant absorption of MHD waves. The dissipation of a significant amount of mechanical energy from the photosphere into the corona through this mechanism could provide sufficient energy to hear the corona. A Monte-Carlo model of the data suggests the presence of enhanced power, particularly in the 0.75-1.0 Hz range, and we conclude that MHD waves remain a viable method for coronal heating.

Jay M. Pasachoff; Bryce A. Babcock; Kevin D. Russell; Daniel B. Seaton

2002-02-12T23:59:59.000Z

19

Attractiveness of periodic orbits in parametrically forced systems with time-increasing friction  

E-Print Network [OSTI]

Attractiveness of periodic orbits in parametrically forced systems with time- increasing friction with time-increasing friction Michele Bartuccelli,1,a) Jonathan Deane,1,b) and Guido Gentile2,c) 1 oscillator in the presence of friction, and study numerically how time-varying friction affects the dynamics

Bartuccelli, Michele

20

ME 544 Advanced Heat Transfer Spring 2013 Time: 2pm-3pm MWF  

E-Print Network [OSTI]

1 ME 544 Advanced Heat Transfer Spring 2013 Time: 2pm-3pm MWF Location: B4 Instructor: Dr. Allan and engineering applications of heat transfer including conduction, convection, and radiation. Course Learning, convection, and radiation heat transfer modes. 2. Determine the dominant modes of heat transfer, and apply

Note: This page contains sample records for the topic "time period heating" 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

QUANTUM ENERGY EXPECTATION IN PERIODIC TIME-DEPENDENT HAMILTONIANS VIA GREEN  

E-Print Network [OSTI]

QUANTUM ENERGY EXPECTATION IN PERIODIC TIME-DEPENDENT HAMILTONIANS VIA GREEN FUNCTIONS C´ESAR R. DE. Introduction 1 2. Average Energy and Green Functions 4 3. Applications 10 3.1. Time-Independent Hamiltonians 10(t). For each positive and discrete observable A (which we call a probe energy), we derive a formula

22

Real-time Scheduling of periodic tasks in a monoprocessor system with rechargeable energy storage  

E-Print Network [OSTI]

Real-time Scheduling of periodic tasks in a monoprocessor system with rechargeable energy storage-time computing system that is powered through a renewable energy storage device. In this context, two constraints for the properties of the energy source, capacity of the energy storage as well as energy consumption of the tasks

Paris-Sud XI, Université de

23

CHP: It's Time for Combined Heat and Power  

E-Print Network [OSTI]

and export 16. Creates local jobs for installation, operation and maintenance 17. Supports competitive electricity market structure General Conclusion It is very much in the PUBLIC interest to support CHP distributed energy… even if the private incentives... of use Electricity Electricity Heat Heat Combined Heat and Power Conventional Generation Building Load Power Plant fuel (66 units of remote energy) Boiler fuel (34 units of on-site energy) CHP fuel (x units of on-site energy) Losses Losses 20 29 20...

Herweck, R.

24

Global Clock, Physical Time Order and Pending Period Analysis in Multiprocessor Systems  

E-Print Network [OSTI]

In multiprocessor systems, various problems are treated with Lamport's logical clock and the resultant logical time orders between operations. However, one often needs to face the high complexities caused by the lack of logical time order information in practice. In this paper, we utilize the \\emph{global clock} to infuse the so-called \\emph{pending period} to each operation in a multiprocessor system, where the pending period is a time interval that contains the performed time of the operation. Further, we define the \\emph{physical time order} for any two operations with disjoint pending periods. The physical time order is obeyed by any real execution in multiprocessor systems due to that it is part of the truly happened operation orders restricted by global clock, and it is then proven to be independent and consistent with traditional logical time orders. The above novel yet fundamental concepts enables new effective approaches for analyzing multiprocessor systems, which are named \\emph{pending period analy...

Chen, Yunji; Hu, Weiwu

2009-01-01T23:59:59.000Z

25

Quantum Energy Expectation in Periodic Time-Dependent hamiltonians via Green Functions  

E-Print Network [OSTI]

Let $U_F$ be the Floquet operator of a time periodic hamiltonian $H(t)$. For each positive and discrete observable $A$ (which we call a {\\em probe energy}), we derive a formula for the Laplace time average of its expectation value up to time $T$ in terms of its eigenvalues and Green functions at the circle of radius $e^{1/T}$. Some simple applications are provided which support its usefulness.

Cesar R. de Oliveira; Mariza S. Simsen

2009-07-31T23:59:59.000Z

26

PREDICTING THE TIME RESPONSE OF A BUILDING UNDER HEAT INPUT CONDITIONS FOR ACTIVE SOLAR HEATING SYSTEMS  

E-Print Network [OSTI]

load calculations effects, some authors[4,5,6] neglect thermal capacitance do consider the response of room tempera- ture to sudden heat

Warren, Mashuri L.

2013-01-01T23:59:59.000Z

27

UC Berkeley Heat/Ventilation Curtailment Period DECEMBER 24, 2011 through JANUARY 1, 2012  

E-Print Network [OSTI]

and January 1, 2012 in order to conserve energy, most campus buildings will be closed and heat and ventilation that a building be exempt from energy curtailment. If you would like to request that your building be exempt from. Technical questions or concerns about energy curtailment can be directed to Gilbert Escobar at 3

California at Irvine, University of

28

HEAT TRANSFERS IN A DOUBLE SKIN ROOF VENTILATED BY NATURAL CONVECTION IN SUMMER TIME  

E-Print Network [OSTI]

1 HEAT TRANSFERS IN A DOUBLE SKIN ROOF VENTILATED BY NATURAL CONVECTION IN SUMMER TIME P. H or in tropical and arid countries. In this work, radiation, convection and conduction heat transfers-dimensional numerical simulation of the heat transfers through the double skin reveals the most important parameters

Boyer, Edmond

29

LINEAR TIME PERIODIC MODELLING OF POWER ELECTRONIC DEVICES FOR POWER SYSTEM HARMONIC ANALYSIS AND SIMULATION  

E-Print Network [OSTI]

LINEAR TIME PERIODIC MODELLING OF POWER ELECTRONIC DEVICES FOR POWER SYSTEM HARMONIC ANALYSIS by simulation. 1. INTRODUCTION The variety and the wide spread use of power electronic devices in the power networks is due to their diverse and multiple functions: compensation, protection and interface

Boyer, Edmond

30

Periodicity detection and localization using spike timing from the AER EAR  

E-Print Network [OSTI]

Periodicity detection and localization using spike timing from the AER EAR Theodore Yu1 , Andrew Event Representation (AER) where each spike carries the identity of the sender. There are a handful of silicon cochleae with an Address Event type representation [4][5][6][7]. The AER EAR chip that we use

Liu, Shih-Chii

31

The effect of periodic unsteady wakes on boundary layer transition and heat transfer on a curved plate  

E-Print Network [OSTI]

generator cross section looking upstream: l. Upper wall, 2. Lower wall, 3. Side wall, 4 Timing belt pulley, 5. Rotating disk, 6. 2. 0 mm diameter cylindrical rod. Test Section: 1. Traversing system, 2. Nozzle, 3. Wake generator, 4. Electric motor, 5...-dimensional mean velocity at different s/s. locations on the heat transfer plate for 0= 0. 0 (0 rods). 39 41 43 Figure 13. Figure 14. Figure 15. Figure 16. Non-dimensional mean velocity at different s/s, locations on the heat transfer plate for Q= 1. 033...

Wright, Lance Cole

1996-01-01T23:59:59.000Z

32

Time-periodic solitons in a damped-driven nonlinear Schrödinger equation  

E-Print Network [OSTI]

Time-periodic solitons of the parametrically driven damped nonlinear Schr\\"odinger equation are obtained as solutions of the boundary-value problem on a two-dimensional spatiotemporal domain. We follow the transformation of the periodic solitons as the strength of the driver is varied. The resulting bifurcation diagrams provide a natural explanation for the overall form and details of the attractor chart compiled previously via direct numerical simulations. In particular, the diagrams confirm the occurrence of the period-doubling transition to temporal chaos for small values of dissipation and the absence of such transitions for larger dampings. This difference in the soliton's response to the increasing driving strength can be traced to the difference in the radiation frequencies in the two cases. Finally, we relate the soliton's temporal chaos to the homoclinic bifurcation.

I. V. Barashenkov; E. V. Zemlyanaya; T. C. van Heerden

2011-03-18T23:59:59.000Z

33

Exploration of period-doubling cascade route to chaos with complex network based time series construction  

E-Print Network [OSTI]

In this work, the topologies of networks constructed from time series from an underlying system undergo a period doubling cascade have been explored by means of the prevalence of different motifs using an efficient computational motif detection algorithm. By doing this we adopt a refinement based on the $k$ nearest neighbor recurrence-based network has been proposed. We demonstrate that the refinement of network construction together with the study of prevalence of different motifs allows a full explosion of the evolving period doubling cascade route to chaos in both discrete and continuous dynamical systems. Further, this links the phase space time series topologies to the corresponding network topologies, and thus helps to understand the empirical "superfamily" phenomenon, as shown by Xu.

Ruoxi Xiang; Michael Small

2014-06-18T23:59:59.000Z

34

Ultrafast time dynamics studies of periodic lattices with free electron laser radiation  

SciTech Connect (OSTI)

It has been proposed that radiation from free electron laser (FEL) at Hamburg (FLASH) can be used for ultrafast time-resolved x-ray diffraction experiments based on the near-infrared (NIR) pump/FEL probe scheme. Here, investigation probing the ultrafast structural dynamics of periodic nano-crystalline organic matter (silver behenate) with such a scheme is reported. Excitation with a femtosecond NIR laser leads to an ultrafast lattice modification which time evolution has been studied through the scattering of vacuum ultraviolet FEL pulses. The found effect last for 6 ps and underpins the possibility for studying nanoperiodic dynamics down to the FEL source time resolution. Furthermore, the possibility of extending the use of silver behenate (AgBh) as a wavelength and temporal calibration tool for experiments with soft x-ray/FEL sources is suggested.

Quevedo, W.; Busse, G.; Hallmann, J.; More, R.; Petri, M.; Rajkovic, I. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Krasniqi, F.; Rudenko, A. [Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany); Tschentscher, T. [European XFEL GmbH, Albert-Einstein-Ring 19, 22671 Hamburg (Germany); Stojanovic, N.; Duesterer, S.; Treusch, R.; Tolkiehn, M. [HASYLAB at DESY, Notkestrasse 85, 22607 Hamburg (Germany); Techert, S. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany)

2012-11-01T23:59:59.000Z

35

QUANTIFYING THE COMBINED EFFECTS OF THE HEATING TIME,1 THE TEMPERATURE AND THE RECOVERY MEDIUM PH ON THE2  

E-Print Network [OSTI]

QUANTIFYING THE COMBINED EFFECTS OF THE HEATING TIME,1 THE TEMPERATURE AND THE RECOVERY MEDIUM PH of the conditions of the heat treatment: temperature, duration15 and pH of the recovery medium. For a given heating Keywords: Bacillus cereus, heat treatment, lag time, recovery.29 30 1. Introduction31 32 Bacillus cereus

Paris-Sud XI, Université de

36

Energy Saving Measures of Heating Network - Computerized Real-time Control System  

E-Print Network [OSTI]

ICEBO2006, Shenzhen, ChinaHVAC Technologies for Energy Efficiency, Vol. IV-12-9 Energy Saving Measures of Heating Network ?Computerized Real-time Control System Jieyan Zhang Service Bureau, Deputy-director, State...

Zhang, J.

2006-01-01T23:59:59.000Z

37

Attractiveness of periodic orbits in parametrically forced systemswith time-increasing friction  

E-Print Network [OSTI]

We consider dissipative one-dimensional systems subject to a periodic force and study numerically how a time-varying friction affects the dynamics. As a model system, particularly suited for numerical analysis, we investigate the driven cubic oscillator in the presence of friction. We find that, if the damping coefficient increases in time up to a final constant value, then the basins of attraction of the leading resonances are larger than they would have been if the coefficient had been fixed at that value since the beginning. From a quantitative point of view, the scenario depends both on the final value and the growth rate of the damping coefficient. The relevance of the results for the spin-orbit model are discussed in some detail.

Michele Bartuccelli; Jonathan Deane; Guido Gentile

2012-07-18T23:59:59.000Z

38

Downstream asymptotics in exterior domains: from stationary wakes to time periodic flows  

E-Print Network [OSTI]

We consider the time-dependent Navier-Stokes equations in a half-space with boundary data on the line $(x,y)=(x_0,y)$ assumed to be time-periodic (or stationary) with a fixed asymptotic velocity ${\\bf u}_{\\infty}=(1,0)$ at infinity. We show that there exist (locally) unique solutions for all data satisfying a compatibility condition in a certain class of fuctions. Furthermore, we prove that asymptotically the vorticity decompose itself in a dominant stationary part on the parabolic scale $y\\sim\\sqrt{x}$ and corrections of order $x^{-{3/2}+\\epsilon}$, while the velocity field decompose itself in a dominant stationary part in form of an explicit multiscale expansion on the scales $y\\sim\\sqrt{x}$ and $y\\sim x$ and corrections decaying at least like $x^{-{9/8}+\\epsilon}$. The asymptotic fields are made of linear combinations of universal functions with coefficients depending mildly on the boundary data. The asymptotic expansion for the component parallel to ${\\bf u}_{\\infty}$ contains `non-trivial' terms in the parabolic scale with amplitude $\\ln(x)x^{-1}$ and $x^{-1}$. To first order, our results also imply that time-periodic wakes behave like stationary ones as $x\\to\\infty$. The class of functions used is `natural' in the sense that `Physically Reasonable' (in the sense of Finn & Smith) stationary solutions of the N.-S. equations around an obstacle are covered if the half-space is choosen sufficiently far downstream. The coefficients appearing in the asymptotics may then be linearly related to the net force acting on the obstacle. To our knowledge, it is the first time that estimates uncovering the $\\ln(x)x^{-1}$ correction are proved in this setting.

G. van Baalen

2004-11-04T23:59:59.000Z

39

Time-delayed feedback control of unstable periodic orbits near a subcritical Hopf bifurcation  

E-Print Network [OSTI]

We show that Pyragas delayed feedback control can stabilize an unstable periodic orbit (UPO) that arises from a generic subcritical Hopf bifurcation of a stable equilibrium in an n-dimensional dynamical system. This extends results of Fiedler et al. [PRL 98, 114101 (2007)], who demonstrated that such feedback control can stabilize the UPO associated with a two-dimensional subcritical Hopf normal form. Pyragas feedback requires an appropriate choice of a feedback gain matrix for stabilization, as well as knowledge of the period of the targeted UPO. We apply feedback in the directions tangent to the two-dimensional center manifold. We parameterize the feedback gain by a modulus and a phase angle, and give explicit formulae for choosing these two parameters given the period of the UPO in a neighborhood of the bifurcation point. We show, first heuristically, and then rigorously by a center manifold reduction for delay differential equations, that the stabilization mechanism involves a highly degenerate Hopf bifurcation problem that is induced by the time-delayed feedback. When the feedback gain modulus reaches a threshold for stabilization, both of the genericity assumptions associated with a two-dimensional Hopf bifurcation are violated: the eigenvalues of the linearized problem do not cross the imaginary axis as the bifurcation parameter is varied, and the real part of the cubic coefficient of the normal form vanishes. Our analysis of this degenerate bifurcation problem reveals two qualitatively distinct cases when unfolded in a two-parameter plane. In each case, Pyragas-type feedback successfully stabilizes the branch of small-amplitude UPOs in a neighborhood of the original bifurcation point, provided that the phase angle satisfies a certain restriction.

Genevieve Brown; Claire M. Postlethwaite; Mary Silber

2010-06-17T23:59:59.000Z

40

PERIODIC HEAT REPORT  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recoveryLaboratorySpeedingOptimizingTools Software and Tools Chos Chos isPDSFGLOWHEAT

Note: This page contains sample records for the topic "time period heating" 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

Internal Space-time Symmetries of Particles derivable from Periodic Systems in Optics  

E-Print Network [OSTI]

While modern optics is largely a physics of harmonic oscillators and two-by-two matrices, it is possible to learn about some hidden properties of the two-by-two matrix from optical systems. Since two-by-two matrices can be divided into three conjugate classes depending on their traces, optical systems force us to establish continuity from one class to another. It is noted that those three classes are equivalent to three different branches of Wigner's little groups dictating the internal space-time symmetries massive, massless, and imaginary-mass particles. It is shown that the periodic systems in optics can also be described by have the same class-based matrix algebra. The optical system allow us to make continuous, but not analytic, transitions from massiv to massless, and massless to imaginary-mass cases.

Y. S. Kim

2010-09-26T23:59:59.000Z

42

Time-delayed apparent excess heat generation in electrolysis fusion experiments  

SciTech Connect (OSTI)

This paper reports that in many recent electrolysis fusion experiments, excess heat, tritium, and neutron production have been reported as intermittent bursts. These burst phenomena are described in terms of a surface reaction mechanism involving hysteresis of deuterium solubility in palladium as a function of the metal temperature. Excess heat generation is shown to be attributable to a hitherto neglected time-delayed chemical process due to the solubility hysteresis of deuterium in palladium. Negative results of no apparent excess heat generation from light-water electrolysis experiments is attributed to the fact that the solubility hysteresis of hydrogen occurs at a higher temperature range than that for deuterium. Apparent excess heat generation is expected to be also observable in blank electrolysis experiments with light water at higher pressures.

Kim, Y.E. (Purdue Univ., Lafayette, IN (United States). Dept. of Physics)

1991-04-10T23:59:59.000Z

43

DIAGNOSING THE TIME DEPENDENCE OF ACTIVE REGION CORE HEATING FROM THE EMISSION MEASURE. II. NANOFLARE TRAINS  

SciTech Connect (OSTI)

The time dependence of heating in solar active regions can be studied by analyzing the slope of the emission measure distribution coolward of the peak. In a previous study we showed that low-frequency heating can account for 0% to 77% of active region core emission measures. We now turn our attention to heating by a finite succession of impulsive events for which the timescale between events on a single magnetic strand is shorter than the cooling timescale. We refer to this scenario as a 'nanoflare train' and explore a parameter space of heating and coronal loop properties with a hydrodynamic model. Our conclusions are (1) nanoflare trains are consistent with 86% to 100% of observed active region cores when uncertainties in the atomic data are properly accounted for; (2) steeper slopes are found for larger values of the ratio of the train duration {Delta} {sub H} to the post-train cooling and draining timescale {Delta} {sub C}, where {Delta} {sub H} depends on the number of heating events, the event duration and the time interval between successive events ({tau} {sub C}); (3) {tau} {sub C} may be diagnosed from the width of the hot component of the emission measure provided that the temperature bins are much smaller than 0.1 dex; (4) the slope of the emission measure alone is not sufficient to provide information about any timescale associated with heating-the length and density of the heated structure must be measured for {Delta} {sub H} to be uniquely extracted from the ratio {Delta} {sub H}/{Delta} {sub C}.

Reep, J. W.; Bradshaw, S. J. [Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States)] [Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States); Klimchuk, J. A., E-mail: jeffrey.reep@rice.edu, E-mail: stephen.bradshaw@rice.edu, E-mail: james.a.klimchuk@nasa.gov [NASA Goddard Space Flight Center, Solar Physics Lab., Code 671, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States)

2013-02-20T23:59:59.000Z

44

Real-time imaging of the spatial distribution of rf-heating in NMR samples during broadband decoupling  

E-Print Network [OSTI]

by the temperature control system. Moreover, as the heating is spatially inhomogeneous, higher temperature increases of the numerical simulations. Since electric fields manifest themselves by rf-heating, the E-field distributionReal-time imaging of the spatial distribution of rf-heating in NMR samples during broadband

Wider, Gerhard

45

Changes in the American Interventional Radiology Literature: Comparison over a 10-Year Time Period  

SciTech Connect (OSTI)

Purpose. To determine the changes that occurred regarding interventional radiologic research in the major American radiology journals between 1992-1993 and 2002-2003. Methods. Articles published in three major American radiology journals (Journal of Vascular and Interventional Radiology, American Journal of Roentgenology, and Radiology) during two distinct 24-month time periods (1992-1993 and 2002-2003) were evaluated. All articles judged to be pertinent to the interventional radiologic community were included. Investigations included in journal subheadings other than 'interventional' or 'vascular radiology' were included if the emphasis of the article was on a vascular imaging modality or peripheral intervention. Exclusions included: case reports, technical reports, letters to the editor, breast interventions, and primary neurointerventions. Data were collected regarding the affiliations of the primary author (nationality, hospital type, department); primary category of interest of the investigation; funding information; and study design variables. Two-by-two chi-squared statistical analyses were performed comparing the variables from the early and late data sets. Results. A total of 405 articles met the inclusion criteria for the early data set (1992-1993); 488 articles met the inclusion criteria for the late data set (2002-2003). Variables that demonstrated a statistically significant decrease from the early data set to the late data set included: articles in which the primary author was from a department of radiology (91.1% vs. 86.3%; p < 0.025); articles written by a primary author who was American (69.4% vs. 44.6%; p < 0.001); and articles with a primary category of investigation that had a nonvascular intervention focus (22.7% vs. 11.9%; p < 0.001). Variables that demonstrated a statistically significant increase from the early data set to the late data set included primary authors from Western Europe (18.0% vs. 30.1%; p < 0.001) and Asia (6.6% vs. 18.4%; p < 0.001), the primary field of investigation, with significant increases noted for primary cancer interventions (6.5% vs. 13.3%; p < 0.001), gynecologic interventions (0.2% vs. 4.5%; p < 0.001), stent-grafts (0 vs. 2.9%; p < 0.001), and spine interventions (0 vs. 1.8%; p < 0.01). Studies receiving funding also demonstrated a significant increase when comparing the early and late data sets (11.3% vs. 23.0%, respectively; p < 0.001). Conclusions. Articles published in the American radiologic literature have changed significantly over the past 10 years. Primary authors are more likely to be nonradiologists and less likely to be American. Investigations dealing primarily with nonvascular interventions are less common; however, some forms of intervention (particularly cancer interventions) are seen more frequently in the literature. The percentage of funded projects has more than doubled in the same time frame.

Ray, Charles E., E-mail: cray@dhha.org; Gupta, Rajan; Blackwell, John [Denver Health Medical Center, Department of Radiology (United States)

2006-08-15T23:59:59.000Z

46

Non-preemptive scheduling of periodic and aperiodic tasks in the hard real-time systems  

E-Print Network [OSTI]

S. 38 40 11 Enumeration tree search . 42 12 Optimizing two requests in the LOQS globally. 13 Identifying dynamic dominant requests. 14 Dispatching requests in ZOgS. 50 51 15 Extraction algorithm. 53 16 Extraction algorithm by heuristic... in hard real ? time environment, the measure- ment criteria for a good algorithm can be a success ratio and a decision time required for dispatching. The success ratio, when a certain algorithm is used, is the ratio of number of tash sets which...

Oh, Hoon

1992-01-01T23:59:59.000Z

47

Periodic Charging Scheme for Fixed-Priority Real-Time Systems with Renewable Energy  

E-Print Network [OSTI]

, the deployed systems use solar panels and piezoelectric units, that exploit solar energy and mechani- cal of the day and season in the case of solar energy); but its rate of supply is not necessarily uniform: the system is not able to harvest solar energy at night time, and energy harvesting rate will vary during

Aydin, Hakan

48

Cooperative heat transfer and ground coupled storage system  

DOE Patents [OSTI]

A cooperative heat transfer and ground coupled storage system wherein collected solar heat energy is ground stored and permitted to radiate into the adjacent ground for storage therein over an extended period of time when such heat energy is seasonally maximally available. Thereafter, when said heat energy is seasonally minimally available and has propagated through the adjacent ground a substantial distance, the stored heat energy may be retrieved by a circumferentially arranged heat transfer means having a high rate of heat transfer.

Metz, Philip D. (Rocky Point, NY)

1982-01-01T23:59:59.000Z

49

Op%mal Scheduling of Combined Heat and Power (CHP) Plants1 under Time-sensi%ve Electricity Prices  

E-Print Network [OSTI]

1 Op%mal Scheduling of Combined Heat and Power (CHP) Plants1 under Time. Combined heat and power genera%on plants are also called co-genera%on plants. #12. #12;Facing the challenge of variability, the power grid is in transi

Grossmann, Ignacio E.

50

Real-Time Combined Heat and Power Operational Strategy Using a Hierarchical Optimization Algorithm  

SciTech Connect (OSTI)

Existing attempts to optimize the operation of Combined Heat and Power (CHP) systems for building applications have two major limitations: the electrical and thermal loads are obtained from historical weather profiles; and the CHP system models ignore transient responses by using constant equipment efficiencies. This paper considers the transient response of a building combined with a hierarchical CHP optimal control algorithm to obtain a real-time integrated system that uses the most recent weather and electric load information. This is accomplished by running concurrent simulations of two transient building models. The first transient building model uses current as well as forecast input information to obtain short term predictions of the thermal and electric building loads. The predictions are then used by an optimization algorithm, i.e., a hierarchical controller, that decides the amount of fuel and of electrical energy to be allocated at the current time step. In a simulation, the actual physical building is not available and, hence, to simulate a real-time environment, a second, building model with similar but not identical input loads are used to represent the actual building. A state-variable feedback loop is completed at the beginning of each time step by copying, i.e., measuring, the state variable from the actual building and restarting the predictive model using these ?measured? values as initial conditions. The simulation environment presented in this paper features nonlinear effects such as the dependence of the heat exchanger effectiveness on their operating conditions. The results indicate that the CHP engine operation dictated by the proposed hierarchical controller with uncertain weather conditions have the potential to yield significant savings when compared to conventional systems using current values of electricity and fuel prices.

Yun, Kyung Tae; Cho, Heejin; Luck, Rogelio; Mago, Pedro J.

2011-06-01T23:59:59.000Z

51

Effects of Time, Heat, and Oxygen on K Basin Sludge Agglomeration, Strength, and Solids Volume  

SciTech Connect (OSTI)

Sludge disposition will be managed in two phases under the K Basin Sludge Treatment Project. The first phase is to retrieve the sludge that currently resides in engineered containers in the K West (KW) Basin pool at ~10 to 18°C. The second phase is to retrieve the sludge from interim storage in the sludge transport and storage containers (STSCs) and treat and package it in preparation for eventual shipment to the Waste Isolation Pilot Plant. The work described in this report was conducted to gain insight into how sludge may change during long-term containerized storage in the STSCs. To accelerate potential physical and chemical changes, the tests were performed at temperatures and oxygen partial pressures significantly greater than those expected in the T Plant canyon cells where the STSCs will be stored. Tests were conducted to determine the effects of 50°C oxygenated water exposure on settled quiescent uraninite (UO2) slurry and a full simulant of KW containerized sludge to determine the effects of oxygen and heat on the composition and mechanical properties of sludge. Shear-strength measurements by vane rheometry also were conducted for UO2 slurry, mixtures of UO2 and metaschoepite (UO3•2H2O), and for simulated KW containerized sludge. The results from these tests and related previous tests are compared to determine whether the settled solids in the K Basin sludge materials change in volume because of oxidation of UO2 by dissolved atmospheric oxygen to form metaschoepite. The test results also are compared to determine if heating or other factors alter sludge volumes and to determine the effects of sludge composition and settling times on sludge shear strength. It has been estimated that the sludge volume will increase with time because of a uranium metal ? uraninite ? metaschoepite oxidation sequence. This increase could increase the number of containers required for storage and increase overall costs of sludge management activities. However, the volume might decrease because of decreases in the water-volume fraction caused by sludge solid reactions, compaction, or intergrowth and recrystallization of metaschoepite. In that case, fewer STSCs may be needed, but the shear strength would increase, and this could challenge recovery by water jet erosion and require more aggressive retrieval methods. Overall, the tests described herein indicate that the settled solids volume remains the same or decreases with time. The only case for which the sludge solids volumes increase with time is for the expansion factor attendant upon the anoxic corrosion of uranium metal to produce UO2 and subsequent reaction with oxygen to form equimolar UO2.25 and UO3•2H2O.

Delegard, Calvin H.; Sinkov, Sergey I.; Schmidt, Andrew J.; Daniel, Richard C.; Burns, Carolyn A.

2011-01-04T23:59:59.000Z

52

DIAGNOSING THE TIME-DEPENDENCE OF ACTIVE REGION CORE HEATING FROM THE EMISSION MEASURE. I. LOW-FREQUENCY NANOFLARES  

SciTech Connect (OSTI)

Observational measurements of active region emission measures contain clues to the time dependence of the underlying heating mechanism. A strongly nonlinear scaling of the emission measure with temperature indicates a large amount of hot plasma relative to warm plasma. A weakly nonlinear (or linear) scaling of the emission measure indicates a relatively large amount of warm plasma, suggesting that the hot active region plasma is allowed to cool and so the heating is impulsive with a long repeat time. This case is called low-frequency nanoflare heating, and we investigate its feasibility as an active region heating scenario here. We explore a parameter space of heating and coronal loop properties with a hydrodynamic model. For each model run, we calculate the slope {alpha} of the emission measure distribution EM(T){proportional_to}T {sup {alpha}}. Our conclusions are: (1) low-frequency nanoflare heating is consistent with about 36% of observed active region cores when uncertainties in the atomic data are not accounted for; (2) proper consideration of uncertainties yields a range in which as many as 77% of observed active regions are consistent with low-frequency nanoflare heating and as few as zero; (3) low-frequency nanoflare heating cannot explain observed slopes greater than 3; (4) the upper limit to the volumetric energy release is in the region of 50 erg cm{sup -3} to avoid unphysical magnetic field strengths; (5) the heating timescale may be short for loops of total length less than 40 Mm to be consistent with the observed range of slopes; (6) predicted slopes are consistently steeper for longer loops.

Bradshaw, S. J.; Reep, J. W. [Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States); Klimchuk, J. A., E-mail: stephen.bradshaw@rice.edu, E-mail: jeffrey.reep@rice.edu, E-mail: james.a.klimchuk@nasa.gov [NASA Goddard Space Flight Center, Solar Physics Lab., Code 671, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States)

2012-10-10T23:59:59.000Z

53

Time delays in quasi-periodic pulsations observed during the X2.2 solar flare on 2011 February 15  

E-Print Network [OSTI]

We report observations of quasi-periodic pulsations (QPPs) during the X2.2 flare of 2011 February 15, observed simultaneously in several wavebands. We focus on fluctuations on time scale 1-30 s and find different time lags between different wavebands. During the impulsive phase, the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) channels in the range 25-100 keV lead all the other channels. They are followed by the Nobeyama RadioPolarimeters at 9 and 17 GHz and the Extreme Ultra-Violet (EUV) channels of the Euv SpectroPhotometer (ESP) onboard the Solar Dynamic Observatory (SDO). The Zirconium and Aluminum filter channels of the Large Yield Radiometer (LYRA) onboard the Project for On-Board Autonomy (PROBA2) satellite and the SXR channel of ESP follow. The largest lags occur in observations from the Geostationary Operational Environmental Satellite (GOES), where the channel at 1-8 {\\AA} leads the 0.5-4 {\\AA} channel by several seconds. The time lags between the first and last channels is up to 9 ...

Dolla, L; Seaton, D B; Van Doorsselaere, T; Dominique, M; Berghmans, D; Cabanas, C; De Groof, A; Schmutz, W; Verdini, A; West, M J; Zender, J; Zhukov, A N

2012-01-01T23:59:59.000Z

54

TIME DELAYS IN QUASI-PERIODIC PULSATIONS OBSERVED DURING THE X2.2 SOLAR FLARE ON 2011 FEBRUARY 15  

SciTech Connect (OSTI)

We report observations of quasi-periodic pulsations (QPPs) during the X2.2 flare of 2011 February 15, observed simultaneously in several wavebands. We focus on fluctuations on timescale 1-30 s and find different time lags between different wavebands. During the impulsive phase, the Reuven Ramaty High Energy Solar Spectroscopic Imager channels in the range 25-100 keV lead all the other channels. They are followed by the Nobeyama RadioPolarimeters at 9 and 17 GHz and the extreme-ultraviolet (EUV) channels of the Euv SpectroPhotometer (ESP) on board the Solar Dynamic Observatory. The zirconium and aluminum filter channels of the Large Yield Radiometer on board the Project for On-Board Autonomy satellite and the soft X-ray (SXR) channel of ESP follow. The largest lags occur in observations from the Geostationary Operational Environmental Satellite, where the channel at 1-8 A leads the 0.5-4 A channel by several seconds. The time lags between the first and last channels is up to Almost-Equal-To 9 s. We identified at least two distinct time intervals during the flare impulsive phase, during which the QPPs were associated with two different sources in the Nobeyama RadioHeliograph at 17 GHz. The radio as well as the hard X-ray channels showed different lags during these two intervals. To our knowledge, this is the first time that time lags are reported between EUV and SXR fluctuations on these timescales. We discuss possible emission mechanisms and interpretations, including flare electron trapping.

Dolla, L.; Marque, C.; Seaton, D. B.; Dominique, M.; Berghmans, D.; Cabanas, C.; De Groof, A.; Verdini, A.; West, M. J.; Zhukov, A. N. [Solar-Terrestrial Center of Excellence, Royal Observatory of Belgium, Avenue Circulaire 3, B-1180 Brussels (Belgium); Van Doorsselaere, T. [Centrum voor Plasma-Astrofysica, Department of Mathematics, KULeuven, Celestijnenlaan 200B bus 2400, B-3001 Leuven (Belgium); Schmutz, W. [Physikalisch-Meteorologisches Observatorium Davos, World Radiation Center, Davos Dorf (Switzerland); Zender, J., E-mail: dolla@sidc.be [European Space Agency, ESTEC, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands)

2012-04-10T23:59:59.000Z

55

Time resolved optical spectroscopy to examine chemical decomposition of energetic materials under static high pressure and pulsed heating conditions  

SciTech Connect (OSTI)

The study of the deflagration or detonation reactions of energetic materials is challenging due to the high pressure, high temperature, and time domain under which the reactions occur. Experimental measurements are presented that demonstrate the ability to continuously monitor the global reaction times and reaction sequences associated with chemical reactions under these conditions. Time resolved absorption spectroscopy is used in conjunction with a high pressure gem anvil cell to probe the real-time chemical processes during pulsed-heating. Samples are initiated by a rapid thermal jump induced by absorption of a single laser pulse. Time resolved absorption spectroscopy of 3,6 trinitroethylamine tetrazine reaction is demonstrated by the real time measurement of the decrease in the {pi}-{pi}* absorption at 100 ns temporal resolution during laser heating at pressures up to 3.5 GPa.

Russell, T.P. [Naval Research Lab., Washington, DC (United States). Chemistry Div.; Allen, T.M.; Gupta, Y.M. [Washington State Univ., Pullman, WA (United States). Shock Dynamics Center

1996-07-01T23:59:59.000Z

56

Use of Time-Aggregated Data in Economic Screening Analyses of Combined Heat and Power Systems  

SciTech Connect (OSTI)

Combined heat and power (CHP) projects (also known as cogeneration projects) usually undergo a series of assessments and viability checks before any commitment is made. A screening analysis, with electrical and thermal loads characterized on an annual basis, may be performed initially to quickly determine the economic viability of the proposed project. Screening analyses using time-aggregated data do not reflect several critical cost influences, however. Seasonal and diurnal variations in electrical and thermal loads, as well as time-of-use utility pricing structures, can have a dramatic impact on the economics. A more accurate economic assessment requires additional detailed data on electrical and thermal demand (e.g., hourly load data), which may not be readily available for the specific facility under study. Recent developments in CHP evaluation tools, however, can generate the needed hourly data through the use of historical data libraries and building simulation. This article utilizes model-generated hourly load data for four potential CHP applications and compares the calculated cost savings of a CHP system when evaluated on a time-aggregated (i.e., annual) basis to the savings when evaluated on an hour-by-hour basis. It is observed that the simple, aggregated analysis forecasts much greater savings (i.e., greater economic viability) than the more detailed hourly analysis. The findings confirm that the simpler tool produces results with a much more optimistic outlook, which, if taken by itself, might lead to erroneous project decisions. The more rigorous approach, being more reflective of actual requirements and conditions, presents a more accurate economic comparison of the alternatives, which, in turn, leads to better decision risk management.

Hudson II, Carl Randy [ORNL

2004-09-01T23:59:59.000Z

57

Summary of Time Period-Based and Other Approximation Methods for Determining the Capacity Value of Wind and Solar in the United States: September 2010 - February 2012  

SciTech Connect (OSTI)

This paper updates previous work that describes time period-based and other approximation methods for estimating the capacity value of wind power and extends it to include solar power. The paper summarizes various methods presented in utility integrated resource plans, regional transmission organization methodologies, regional stakeholder initiatives, regulatory proceedings, and academic and industry studies. Time period-based approximation methods typically measure the contribution of a wind or solar plant at the time of system peak - sometimes over a period of months or the average of multiple years.

Rogers, J.; Porter, K.

2012-03-01T23:59:59.000Z

58

Modeling reaction quench times in the waste heat boiler of a Claus plant  

SciTech Connect (OSTI)

At the high temperatures found in the modified Claus reaction furnace, the thermal decomposition and oxidation of H[sub 2]S yields large quantities of desirable products, gaseous hydrogen (H[sub 2]) and sulfur (S[sub 2]). However, as the temperature of the gas stream is lowered in the waste heat boiler (WHB) located downstream of the furnace, the reverse reaction occurs leading to reassociation of H[sub 2] and S[sub 2] molecules. To examine the reaction quenching capabilities of the WHB, a rigorous computer model was developed incorporating recently published intrinsic kinetic data. A sensitivity study performed with the model demonstrated that WHBs have a wide range of operation with gas mass flux in the tubes from 4 to 24 kg/(m[sup 2] [center dot] s). Most important, the model showed that is was possible to operate WHBs such that quench times could be decreased to 40 ms, which is a reduction by 60% compared to a base case scenario. Furthermore, hydrogen production could be increased by over 20% simply by reconfiguring the WHB tubes.

Nasato, L.V.; Karan, K.; Mehrotra, A.K.; Behie, L.A. (Univ. of Calgary, Alberta (Canada). Dept. of Chemical and Petroleum Engineering)

1994-01-01T23:59:59.000Z

59

Earth Planets Space, 57, 895902, 2005 Short time-scale heating of the Earth's mantle by ice-sheet dynamics  

E-Print Network [OSTI]

by modeling the linear response of a self-gravitating viscoelastic planet, the gravity field anoma- lies haveEarth Planets Space, 57, 895­902, 2005 Short time-scale heating of the Earth's mantle by ice-scale energy transfer from the ice sheet loading and unloading processes to the Earth's interior via viscous

Hanyk, Ladislav

60

Functional Integral approach to time-dependent heat exchange in open quantum systems: general method and applications  

E-Print Network [OSTI]

We establish the path integral approach for the time-dependent heat exchange of an externally driven quantum system coupled to a thermal reservoir. We derive the relevant influence functional and present an exact formal expression for the moment generating functional which carries all statistical properties of the heat exchange process for general linear dissipation. The general method is applied to the time-dependent average heat transfer in the dissipative two-state system. We show that the heat can be written as a convolution integral which involves the population and coherence correlation functions of the two-state system and additional correlations due to a polarization of the reservoir. The corresponding expression can be solved in the weak-damping limit both for white noise and for quantum mechanical coloured noise. The implications of pure quantum effects are discussed. Altogether a complete description of the dynamics of the average heat transfer ranging from the classical regime down to zero temperature is achieved.

M. Carrega; P. Solinas; A. Braggio; M. Sassetti; U. Weiss

2014-12-22T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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61

Chemical heat pump  

DOE Patents [OSTI]

A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer. The heat pump part of the system heats or cools a house or other structure through a combination of evaporation and absorption or, conversely, condensation and desorption, in a pair of containers. A set of automatic controls change the system for operation during winter and summer months and for daytime and nighttime operation to satisfactorily heat and cool a house during an entire year. The absorber chamber is subjected to solar heating during regeneration cycles and is covered by one or more layers of glass or other transparent material. Daytime home air used for heating the home is passed at appropriate flow rates between the absorber container and the first transparent cover layer in heat transfer relationship in a manner that greatly reduce eddies and resultant heat loss from the absorbant surface to ambient atmosphere.

Greiner, Leonard (2750-C Segerstrom Ave., Santa Ana, CA 92704)

1980-01-01T23:59:59.000Z

62

A fully second order implicit/explicit time integration technique for hydrodynamics plus nonlinear heat conduction problems  

SciTech Connect (OSTI)

We present a fully second order implicit/explicit time integration technique for solving hydrodynamics coupled with nonlinear heat conduction problems. The idea is to hybridize an implicit and an explicit discretization in such a way to achieve second order time convergent calculations. In this scope, the hydrodynamics equations are discretized explicitly making use of the capability of well-understood explicit schemes. On the other hand, the nonlinear heat conduction is solved implicitly. Such methods are often referred to as IMEX methods. The Jacobian-Free Newton Krylov (JFNK) method (e.g. ) is applied to the problem in such a way as to render a nonlinearly iterated IMEX method. We solve three test problems in order to validate the numerical order of the scheme. For each test, we established second order time convergence. We support these numerical results with a modified equation analysis (MEA). The set of equations studied here constitute a base model for radiation hydrodynamics.

Kadioglu, Samet Y. [Multiphysics Methods Group, Reactor Physics Analysis and Design, Idaho National Laboratory, P.O. Box 1625, MS 3840, Idaho Falls, ID 83415 (United States)], E-mail: Samet.Kadioglu@inl.gov; Knoll, Dana A. [Multiphysics Methods Group, Reactor Physics Analysis and Design, Idaho National Laboratory, P.O. Box 1625, MS 3840, Idaho Falls, ID 83415 (United States)], E-mail: dana.knoll@inl.gov

2010-05-01T23:59:59.000Z

63

Long time existence of regular solutions to 3d Navier-Stokes equations coupled with the heat convection  

E-Print Network [OSTI]

We prove long time existence of regular solutions to the Navier-Stokes equations coupled with the heat equation. We consider the system in non-axially symmetric cylinder with the slip boundary conditions for the Navier-Stokes equations and the Neumann condition for the heat equation. The long time existence is possible because we assumed that derivatives with respect to the variable along the axis of the cylinder of the initial velocity, initial temperature and the external force in $L_2$ norms are sufficiently small. We proved the existence of such solutions that velocity and temperature belong to $W_\\sigma^{2,1}(\\Omega\\times(0,T))$, where $\\sigma>{5\\over3}$. The existence is proved by the Leray-Schauder fixed point theorem.

Jolanta Socala; Wojciech M. Zajaczkowski

2011-03-21T23:59:59.000Z

64

Long time existence of regular solutions to 3d Navier-Stokes equations coupled with the heat convection  

E-Print Network [OSTI]

We prove long time existence of regular solutions to the Navier-Stokes equations coupled with the heat equation. We consider the system in non-axially symmetric cylinder with the slip boundary conditions for the Navier-Stokes equations and the Neumann condition for the heat equation. The long time existence is possible because we assumed that derivatives with respect to the variable along the axis of the cylinder of the initial velocity, initial temperature and the external force in $L_2$ norms are sufficiently small. We proved the existence of such solutions that velocity and temperature belong to $W_\\sigma^{2,1}(\\Omega\\times(0,T))$, where $\\sigma>{5\\over3}$. The existence is proved by the Leray-Schauder fixed point theorem.

Socala, Jolanta

2011-01-01T23:59:59.000Z

65

A systematic periodicity and time-variable modulation search in RXTE ASM data : methods, findings, and implications for astrophysical X-ray sources  

E-Print Network [OSTI]

In this work, we present the results of a general search for periodicities and for time-variable modulation strength in X-ray sources using data from the All-Sky Monitor onboard the Rossi X-ray Timing Explorer. New findings, ...

Harris, Robert J., S.M. Massachusetts Institute of Technology

2007-01-01T23:59:59.000Z

66

Integrating preconcentrator heat controller  

DOE Patents [OSTI]

A method and apparatus for controlling the electric resistance heating of a metallic chemical preconcentrator screen, for example, used in portable trace explosives detectors. The length of the heating time-period is automatically adjusted to compensate for any changes in the voltage driving the heating current across the screen, for example, due to gradual discharge or aging of a battery. The total deposited energy in the screen is proportional to the integral over time of the square of the voltage drop across the screen. Since the net temperature rise, .DELTA.T.sub.s, of the screen, from beginning to end of the heating pulse, is proportional to the total amount of heat energy deposited in the screen during the heating pulse, then this integral can be calculated in real-time and used to terminate the heating current when a pre-set target value has been reached; thereby providing a consistent and reliable screen temperature rise, .DELTA.T.sub.s, from pulse-to-pulse.

Bouchier, Francis A. (Albuquerque, NM); Arakaki, Lester H. (Edgewood, NM); Varley, Eric S. (Albuquerque, NM)

2007-10-16T23:59:59.000Z

67

Time sequenced heating of multiple layers in a hydrocarbon containing formation  

DOE Patents [OSTI]

A method for treating a hydrocarbon containing formation may include providing heat to a first hydrocarbon layer in the formation from a first heater located in an opening in the formation. The opening and the first heater may have a horizontal or inclined portion located in the first hydrocarbon layer and at least one connecting portion extending between the horizontal or inclined portion and the surface. Isolation material is placed in the opening such that the isolation material partially isolates the layer in which the horizontal or inclined portion of the first heater is located. An additional horizontal or inclined opening portion that extends from at least one of the connecting portions of the opening is formed in a second hydrocarbon layer. A second heater to provide heat the second hydrocarbon formation is placed in the additional substantially horizontal opening portion.

Goldberg, Bernard (Houston, TX); Hale, Arthur Herman (Houston, TX); Miller, David Scott (Katy, TX); Vinegar, Harold J. (Bellaire, TX)

2009-12-22T23:59:59.000Z

68

Chemical heat pump  

DOE Patents [OSTI]

A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

Greiner, Leonard (2853-A Hickory Pl., Costa Mesa, CA 92626)

1981-01-01T23:59:59.000Z

69

Chemical heat pump  

DOE Patents [OSTI]

A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate intallation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

Greiner, Leonard (2853-A Hickory Pl., Costa Mesa, CA 92626)

1984-01-01T23:59:59.000Z

70

Chemical heat pump  

DOE Patents [OSTI]

A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

Greiner, Leonard (2853-A Hickory Pl., Costa Mesa, CA 92626)

1984-01-01T23:59:59.000Z

71

Chemical heat pump  

DOE Patents [OSTI]

A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to faciliate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

Greiner, Leonard (2853-A Hickory Pl., Costa Mesa, CA 92626)

1984-01-01T23:59:59.000Z

72

The aligned nuclear targets for investigation of time reversal invariance violation: thermal heating and optimization of target dimension  

E-Print Network [OSTI]

The thermal heating of aligned nuclear targets of HIO_3, LiIO_3 ans Sb target materials under neutron irradiation at JSNS is considered. It is shown that presently the targets of large volumes (several tens of cm^3) can be used in experiment. The optimal target dimensions are recommended for investigation with resonance neutrons. The use of proposed aligned targets at the new neutron spallation source JSNS (Japan) will make p[ossible to discover TRIV or decrease the present limit on the intensity of parity conserving time violating interaction by two-three order of magnitude.

A. G. Beda; A. S. Gerasimov

2007-06-18T23:59:59.000Z

73

Long time estimate of solutions to 3d Navier-Stokes equations coupled with the heat convection  

E-Print Network [OSTI]

We examine the Navier-Stokes equations with homogeneous slip boundary conditions coupled with the heat equation with homogeneous Neumann conditions in a bounded domain in $R^3$. The considered domain is a cylinder with $x_3$-axis. The aim of this paper is to show long time estimates without smallness of the initial velocity, the initial temperature and the external force. To prove the estimate we need however smallness of $L_2$ norms of derivatives with respect to $x_3$ of the initial velocity, the initial temperature and the external force.

Socala, Jolanta

2011-01-01T23:59:59.000Z

74

Long time estimate of solutions to 3d Navier-Stokes equations coupled with the heat convection  

E-Print Network [OSTI]

We examine the Navier-Stokes equations with homogeneous slip boundary conditions coupled with the heat equation with homogeneous Neumann conditions in a bounded domain in $R^3$. The considered domain is a cylinder with $x_3$-axis. The aim of this paper is to show long time estimates without smallness of the initial velocity, the initial temperature and the external force. To prove the estimate we need however smallness of $L_2$ norms of derivatives with respect to $x_3$ of the initial velocity, the initial temperature and the external force.

Jolanta Socala; Wojciech M. Zajaczkowski

2011-03-21T23:59:59.000Z

75

Extension and improvement of Central Station District heating budget period 1 and 2, Krakow Clean Fossil Fuels and Energy Efficiency Program. Final report  

SciTech Connect (OSTI)

Project aim was to reduce pollution levels in the City of Krakow through the retirement of coal-fired (hand and mechanically-stoked) boiler houses. This was achieved by identifying attractive candidates and connecting them to the Krakow district heating system, thus permitting them to eliminate boiler operations. Because coal is less costly than district hot water, the district heating company Miejskie Przedsiebiorstwo Energetyki Cieplnej S.A., henceforth identified as MPEC, needed to provide potential customers with incentives for purchasing district heat. These incentives consisted of offerings which MPEC made to the prospective client. The offerings presented the economic and environmental benefits to district heating tie-in and also could include conservation studies of the facilities, so that consumption of energy could be reduced and the cost impact on operations mitigated. Because some of the targeted boiler houses were large, the capacity of the district heating network required enhancement at strategic locations. Consequently, project construction work included both enhancement to the district piping network as well as facility tie-ins. The process of securing new customers necessitated the strengthening of MPEC`s competitive position in Krakow`s energy marketplace, which in turn required improvements in marketing, customer service, strategic planning, and project management. Learning how US utilities address these challenges became an integral segment of the project`s scope.

NONE

1997-07-01T23:59:59.000Z

76

JOURNAL OF STRUCTURAL ENGINEERING / MAY 2001 / 527 APPARENT PERIODS OF A BUILDING. II: TIME-FREQUENCY ANALYSIS  

E-Print Network [OSTI]

of a two-part paper, the analysis of the apparent frequency of a seven-story reinforced-concrete hotel. The results also suggest ``self healing'' believed to result from settlement of the soil with time and dynamic compaction from aftershock shaking. Implications of such high variability of the system frequency

Southern California, University of

77

Time-resolved Spectroscopy of Laser-heated Copper Foils | Stanford  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus TomAboutManusScienceThe43068G.Time-Resolved Study ofSynchrotron

78

The Parkes multibeam pulsar survey: VII. Timing of four millisecond pulsars and the underlying spin period distribution of the Galactic millisecond pulsar population  

E-Print Network [OSTI]

We present timing observations of four millisecond pulsars discovered in the Parkes 20-cm multibeam pulsar survey of the Galactic plane. PSRs J1552-4937 and J1843-1448 are isolated objects with spin periods of 6.28 and 5.47 ms respectively. PSR J1727-2946 is in a 40-day binary orbit and has a spin period of 27 ms. The 4.43-ms pulsar J1813-2621 is in a circular 8.16-day binary orbit around a low-mass companion star with a minimum companion mass of 0.2 solar masses. Combining these results with detections from five other Parkes multibeam surveys, gives a well-defined sample of 56 pulsars with spin periods below 20 ms. We develop a likelihood analysis to constrain the functional form which best describes the underlying distribution of spin periods for millisecond pulsars. The best results were obtained with a log-normal distribution. A gamma distribution is less favoured, but still compatible with the observations. Uniform, power-law and Gaussian distributions are found to be inconsistent with the data. Galactic...

Lorimer, D R; Manchester, R N; Possenti, A; Lyne, A G; McLaughlin, M A; Kramer, M; Hobbs, G; Stairs, I H; Burgay, M; Eatough, R P; Keith, M J; Faulkner, A J; D'Amico, N; Camilo, F; Corongiu, A; Crawford, F

2015-01-01T23:59:59.000Z

79

Novel Controls for Time-Dependent Economic Dispatch of Combined Cooling Heating and Power (CCHP)  

SciTech Connect (OSTI)

The research and development effort detailed in this report directly addresses the challenge of reducing U.S. industrial energy and carbon intensity by contributing to an increased understanding of potential CCHP technology, the CCHP market and the challenges of widespread adoption. This study developed a number of new tools, models, and approaches for the design, control, and optimal dispatch of various CCHP technologies. The UC Irvine campus served as a ‘living laboratory’ of new CCHP technologies and enabled the design and demonstration of several novel control methods. In particular, the integration of large scale thermal energy storage capable of shifting an entire day of cooling demand required a novel approach to the CCHP dispatch optimization. The thermal energy storage proved an economically viable resource which reduced both costs and emissions by enabling generators and chillers to operate under steady high efficiency conditions at all times of the day.

Samuelsen, Scott; Brouwer, Jack

2013-08-31T23:59:59.000Z

80

Minimal universal quantum heat machine  

E-Print Network [OSTI]

In traditional thermodynamics the Carnot cycle yields the ideal performance bound of heat engines and refrigerators. We propose and analyze a minimal model of a heat machine that can play a similar role in quantum regimes. The minimal model consists of a single two-level system with periodically modulated energy splitting that is permanently, weakly, coupled to two spectrally-separated heat baths at different temperatures. The equation of motion allows to compute the stationary power and heat currents in the machine consistently with the second-law of thermodynamics. This dual-purpose machine can act as either an engine or a refrigerator (heat pump) depending on the modulation rate. In both modes of operation the maximal Carnot efficiency is reached at zero power. We study the conditions for finite-time optimal performance for several variants of the model. Possible realizations of the model are discussed.

David Gelbwaser-Klimovsky; Robert Alicki; Gershon Kurizki

2012-09-06T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" 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

2014-11-25 Issuance: Energy Conservation Standards for Small, Large, and Very Large Air-cooled Commercial Package Air Conditioning and Heating Equipment; Extension of Public Comment Period  

Broader source: Energy.gov [DOE]

This document is a pre-publication Federal Register extension of the public comment period regarding energy conservation standards for small, large and very large air-cool commercial package air conditioning and heating equipment, as issued by the Deputy Assistant Secretary for Energy Efficiency on November 25, 2014. Though it is not intended or expected, should any discrepancy occur between the document posted here and the document published in the Federal Register, the Federal Register publication controls. This document is being made available through the Internet solely as a means to facilitate the public's access to this document.

82

Modeling the time and energy behavior of the GCR intensity in the periods of low activity around the last three solar minima  

E-Print Network [OSTI]

Using the simple model for the description of the GCR modulation in the heliosphere and the sets of parameters discussed in the accompanying paper we model some features of the time and energy behavior of the GCR intensity near the Earth observed during periods of low solar activity around three last solar minima. In order to understand the mechanisms underlying these features in the GCR behavior, we use the suggested earlier decomposition of the calculated intensity into the partial intensities corresponding to the main processes (diffusion, adiabatic losses, convection and drifts).

Krainev, M B; Kalinin, M S; Svirzhevskaya, A K; Svirzhevsky, N S

2014-01-01T23:59:59.000Z

83

Combined effects of Reynolds number, turbulence intensity and periodic unsteady wake flow conditions on boundary layer development and heat transfer of a low pressure turbine blade  

E-Print Network [OSTI]

.18 (S R =80 mm)........................................103 Figure 11.1. Static pressure distributions at Re=110,000 and reduced frequencies S=0, 1.59, 3.18 (no rod, 160 mm, 80 mm), SS=Separation start, SE= Separation end...................................................110 Figure 11.2. Time-averaged hot-film distributions at Re=110,000 and reduced frequencies S=0, 1.59, 3.18 (no rod, 160 mm, 80 mm)...........................112 Figure 11.3. Ensemble averaged velocity as a function for (a) steady flow case S=0 (S R...

Ozturk, Burak

2009-05-15T23:59:59.000Z

84

Plasma heating in a variable magnetic field  

SciTech Connect (OSTI)

The problem of particle acceleration in a periodically variable magnetic field that either takes a zero value or passes through zero is considered. It is shown that, each time the field [0]passes through zero, the particle energy increases abruptly. This process can be regarded as heating in the course of which plasma particles acquire significant energy within one field period. This mechanism of plasma heating takes place in the absence of collisions between plasma particles and is analogous to the mechanism of magnetic pumping in collisional plasma considered by Alfven.

Kichigin, G. N., E-mail: king@iszf.irk.ru [Russian Academy of Sciences, Institute of Solar-Terrestrial Physics (Russian Federation)

2013-05-15T23:59:59.000Z

85

Performance of Horizontal Field Earth-Coupled Heat Pumps  

E-Print Network [OSTI]

An alternative to traditional methods of residential heating and cooling is the heat pump. However, heat pumps which use the outside air as a heat source/sink become inefficient during the periods of highest demand. Another possible heat source...

Abbott, C. A.

1986-01-01T23:59:59.000Z

86

Condensing Heating and Water Heating Equipment Workshop Location...  

Energy Savers [EERE]

Condensing Heating and Water Heating Equipment Workshop Location: Washington Gas Light Appliance Training Facility 6801 Industrial Road Springfield, VA Date: October 9, 2014 Time:...

87

Heat pipe array heat exchanger  

DOE Patents [OSTI]

A heat pipe arrangement for exchanging heat between two different temperature fluids. The heat pipe arrangement is in a ounterflow relationship to increase the efficiency of the coupling of the heat from a heat source to a heat sink.

Reimann, Robert C. (Lafayette, NY)

1987-08-25T23:59:59.000Z

88

Heat storage with CREDA  

SciTech Connect (OSTI)

The principle of operation of ETS or Electric Thermal Storage is discussed in this book. As can be seen by the diagram presented, heating elements buried deep within the core are energized during off-peak periods or periods of lower cost energy. These elements charge the core to a per-determined level, then during the on-peak periods when the cost of electricity is higher or demand is higher, the heat is extracted from the core. The author discusses how this technology has progressed to the ETS equipment of today; this being the finer control of charging rates and extraction of heat from the core.

Beal, T. (Fostoria Industries, Fostoria, OH (US))

1987-01-01T23:59:59.000Z

89

Solar water heating technical support. Technical report for November 1997--April 1998 and final report  

SciTech Connect (OSTI)

This progress report covers the time period November 1, 1997 through April 30, 1998, and also summarizes the project as the final report. The topics of the report include certification of solar collectors for water heating systems, modeling and testing of solar collectors and gas water heater backup systems, ratings of collectors for specific climates, and solar pool heating systems.

Huggins, J.

1998-10-01T23:59:59.000Z

90

Observations of Ferrite/Austenite Transformations in the Heat Affected Zone of 2205 Duplex Stainless Steel Spot Welds Using Time Resolved X-Ray Diffraction  

SciTech Connect (OSTI)

Time Resolved X-Ray Diffraction (TRXRD) measurements are made in the Heat Affected Zone (HAZ) of 2205 Duplex Stainless Steel (DSS) spot welds. Both the {gamma} {yields} {delta} and {delta} {yields} {gamma} transformations are monitored as a function of time during the rapid spot weld heating and cooling cycles. These observations are then correlated with calculated thermal cycles. Where the peak temperatures are highest ({approx}1342 C), the {gamma} {yields} {delta} transformation proceeds to completion, leaving a ferritic microstructure at the end of heating. With lower peak temperatures, the {gamma} {yields} {delta} transformation proceeds to only partial completion, resulting in a microstructure containing both transformed and untransformed austenite. Further analyses of the individual diffraction patterns show shifts in the peak positions and peak widths as a function of both time and temperature. In addition, these changes in the peak characteristics are correlated with measured changes in the ferrite volume fraction. Such changes in the peak positions and widths during the {gamma} {yields} {delta} transformation provide an indication of changes occurring in each phase. These changes in peak properties can be correlated with the diffusion of nitrogen and other substitutional alloying elements, which are recognized as the primary mechanisms for this transformation. Upon cooling, the {delta} {yields} {gamma} transformation is observed to proceed from both the completely and partially transformed microstructural regions in the TRXRD data. An examination of the resulting microstructures confirms the TRXRD observation as the evidence shows that austenite both nucleates and grows from the ferritic microstructure at locations closest to the fusion zone boundary and grows from untransformed austenite grains at locations further from this boundary.

Palmer, T; Elmer, J; Babu, S

2003-10-29T23:59:59.000Z

91

A microsecond time resolved x-ray absorption near edge structure synchrotron study of phase transitions in Fe undergoing ramp heating at high pressure  

SciTech Connect (OSTI)

We report a microsecond time-resolved x-ray absorption near edge structure study using synchrotron radiation to dynamically detect structural phase transitions in Fe undergoing rapid heating along a quasi-isochoric path. Within a few ms, we observed two structural phase transitions, which transform the ambient bcc phase of Fe into the fcc phase, and then into the liquid phase. This example illustrates the opportunities offered by energy dispersive x-ray absorption spectroscopy in the study of matter under extreme dynamic conditions. Advanced simulations are compared to these data.

Marini, C.; Mathon, O.; Pascarelli, S. [European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, BP220, 38043 Grenoble Cedex (France); Occelli, F.; Torchio, R.; Recoules, V.; Loubeyre, P. [CEA, Bruyeres le Chatel, 91297 Arpajon Cedex (France)

2014-03-07T23:59:59.000Z

92

Heat flow in anharmonic crystals with internal and external stochastic baths: A convergent polymer expansion for a model with discrete time and long range interparticle interaction  

E-Print Network [OSTI]

We investigate a chain of oscillators with anharmonic on-site potentials, with long range interparticle interactions, and coupled both to external and internal stochastic thermal reservoirs of Ornstein-Uhlenbeck type. We develop an integral representation, a la Feynman-Kac, for the correlations and the heat current. We assume the approximation of discrete times in the integral formalism (together with a simplification in a subdominant part of the harmonic interaction) in order to develop a suitable polymer expansion for the model. In the regime of strong anharmonicity, strong harmonic pinning, and for the interparticle interaction with integrable polynomial decay, we prove the convergence of the polymer expansion uniformly in volume (number of sites and time). We also show that the two-point correlation decays in space such as the interparticle interaction. The existence of a convergent polymer expansion is of practical interest: it establishes a rigorous support for a perturbative analysis of the heat flow problem and for the computation of the thermal conductivity in related anharmonic crystals, including those with inhomogeneous potentials and long range interparticle interactions.

Emmanuel Pereira; Mateus S. Mendonça; Humberto C. F. Lemos

2014-11-23T23:59:59.000Z

93

Molecular heat pump  

E-Print Network [OSTI]

We propose a novel molecular device that pumps heat against a thermal gradient. The system consists of a molecular element connecting two thermal reservoirs that are characterized by different spectral properties. The pumping action is achieved by applying an external force that periodically modulates molecular levels. This modulation affects periodic oscillations of the internal temperature of the molecule and the strength of its coupling to each reservoir resulting in a net heat flow in the desired direction. The heat flow is examined in the slow and fast modulation limits and for different modulation waveforms, thus making it possible to optimize the device performance.

Dvira Segal; Abraham Nitzan

2005-10-11T23:59:59.000Z

94

Optimization of Heat Exchanger Cleaning  

E-Print Network [OSTI]

decrease models of the heat recovery decay. A mathematical comparison of mechanical and chemical cleaning of heat exchangers has identified the most significant parameters which affect the choice between the two methods. INTRODUCTION In most... can be somewhat mitigated by periodic chemical or mechanical cleaning of the exchanger surface, and by the addition of antifoul ants. The typical decay in heat recovery capabil ity due to fou 1i ng and restoration afte r heat exchanger cleaning...

Siegell, J. H.

95

On the solution of the Heaviside - Klein - Gordon thermal equation for heat transport in graphene  

E-Print Network [OSTI]

We report studies of the solution of the Heaviside - Klein - Gordon thermal equation. As the result it is shown that the solution consists of two components: the fast thermal wave and slow diffusion for very large (compared to relaxation time) time period. We argue that the fast thermal wave can be recognized as the indication of the ballistic heat transport. As an example we consider the ballistic heat transport in graphene.

Magdalena Pelc

2007-11-26T23:59:59.000Z

96

Photovoltaic roof heat flux  

E-Print Network [OSTI]

under the offset unit's solar panel, the hf formula (16) wasdrop below the angle unit's solar panel at night time. D u rfor both the units, the solar panel covered roof was a heat

Samady, Mezhgan Frishta

2011-01-01T23:59:59.000Z

97

EnergyPlus Run Time Analysis  

E-Print Network [OSTI]

integrated heat balance calculations for loads, systems, andintegrated heat balance calculations for loads, systems, andloads calculation time steps per hour, the model solution algorithms (envelope heat

Hong, Tianzhen

2009-01-01T23:59:59.000Z

98

Laser-induced short time scale thermal chemistry of perfluoropolyether lubricant films  

SciTech Connect (OSTI)

The authors investigate the effect of heating a perfluoropolyether lubricant film in a localized area for relatively short time periods using laser irradiation versus conventional oven heating. These experiments help provide understanding on how flash temperatures generated at frictional contacts affect the thermal chemistry of lubricant films. In these experiments, a CO{sub 2} laser heats a 50 {micro}m wide area of a silicon wafer for time periods ranging from 0.1 to 60 s. The surface temperature within the heated area (up to 280 C in these experiments) is monitored with a second laser by measuring the change in reflectivity near the center of the heated area. A major difference observed for laser heating compared to oven heating is that the effective evaporation rate is orders of magnitude higher for laser heating. If the lubricant film is heated for sufficiently long enough time at high temperatures, the authors are able to observe thermal bonding of the lubricant via its alcohol end groups to the silicon oxide surface, followed by thermal decomposition of the lubricant molecules. After laser heating, the authors are able to observe the diffusion of lubricant back into the localized heated area using a combination of optical microscopy and imaging ellipsometry.

Heller, J.; Mate, C.J.; Poon, C.C.; Tam, A.C.

1999-11-09T23:59:59.000Z

99

Storm Water Analytical Period  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Storm Water Analytical Period Storm Water Analytical Period The Individual Permit authorizes the discharge of storm water associated with historical industrial activities at LANL...

100

Temperature profile of the infrared image Heat exchange between  

E-Print Network [OSTI]

T Temperature profile of the infrared image Heat exchange between atmosphere and ocean References coefficient of heat in water determine the heat transfer velocity: *t Infrared images of the water surface: a-Karls-Universität Heidelberg www.uni-heidelberg.de Active controlled flux technique (ACFT) Continuous heat flux Periodic heat

Jaehne, Bernd

Note: This page contains sample records for the topic "time period heating" 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

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 1,602 1,397...

102

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 1,870 1,276...

103

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Energy Consumption Survey: Energy End-Use Consumption Tables Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All...

104

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings ... 2,037...

105

Susanville District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

Susanville District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Susanville District Heating District Heating Low Temperature...

106

Heating system  

SciTech Connect (OSTI)

A heating system utilizing solar panels and buried ground conduits to collect and store heat which is delivered to a heatpump heat exchanger. A heat-distribution fluid continuously circulates through a ground circuit to transfer heat from the ground to the heat exchanger. The ground circuit includes a length of buried ground conduit, a pump, a check valve and the heat exchanger. A solar circuit, including a solar panel and a second pump, is connected in parallel with the check valve so that the distribution fluid transfers solar heat to the heat exchanger for utilization and to the ground conduit for storage when the second pump is energized. A thermostatically instrumented control system energizes the second pump only when the temperature differential between the solar panel inlet and outlet temperatures exceeds a predetermined value and the ground temperature is less than a predetermined value. Consequently, the distribution fluid flows through the solar panel only when the panel is capable of supplying significant heat to the remainder of the system without causing excessive drying of the ground.

Nishman, P.J.

1983-03-08T23:59:59.000Z

107

Characterization of self-propagating formation reactions in Ni/Zr multilayered foils using reaction heats, velocities, and temperature-time profiles  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

We report on intermetallic formation reactions in vapor-deposited multilayered foils of Ni/Zr with 70 nm bilayers and overall atomic ratios of Ni:Zr, 2 Ni:Zr, and 7 Ni:2 Zr. The sequence of alloy phase formation and the stored energy is evaluated at slow heating rates (~1 K/s) using differential scanning calorimetry (DSC) traces to 725ºC. All three chemistries initially form a Ni-Zr amorphous phase which crystallizes first to the intermetallic NiZr. The heat of reaction to the final phase is 34-36 kJ/mol atom for all chemistries. Intermetallic formation reactions are also studied at rapid heating rates (greater than 105 K/s) in high temperature, self-propagating reactions which can be ignited in these foils by an electric spark. We find that reaction velocities and maximum reaction temperatures (Tmax) are largely independent of foil chemistry at 0.6 ± 0.1 m/s and 1220 ± 50 K, respectively, and that the measured Tmax is more than 200 K lower than predicted adiabatic temperatures (Tad). The difference between Tmax and Tad is explained by the prediction that transformation to the final intermetallic phases occurs after Tmax and results in the release of 20-30 % of the total heat of reaction and a delay in rapid cooling.

Barron, S. C.; Knepper, R.; Walker, N.; Weihs, T. P.

2011-01-11T23:59:59.000Z

108

Characterization of self-propagating formation reactions in Ni/Zr multilayered foils using reaction heats, velocities, and temperature-time profiles  

SciTech Connect (OSTI)

We report on intermetallic formation reactions in vapor-deposited multilayered foils of Ni/Zr with 70 nm bilayers and overall atomic ratios of Ni:Zr, 2 Ni:Zr, and 7 Ni:2 Zr. The sequence of alloy phase formation and the stored energy is evaluated at slow heating rates (~1 K/s) using differential scanning calorimetry (DSC) traces to 725ºC. All three chemistries initially form a Ni-Zr amorphous phase which crystallizes first to the intermetallic NiZr. The heat of reaction to the final phase is 34-36 kJ/mol atom for all chemistries. Intermetallic formation reactions are also studied at rapid heating rates (greater than 105 K/s) in high temperature, self-propagating reactions which can be ignited in these foils by an electric spark. We find that reaction velocities and maximum reaction temperatures (Tmax) are largely independent of foil chemistry at 0.6 ± 0.1 m/s and 1220 ± 50 K, respectively, and that the measured Tmax is more than 200 K lower than predicted adiabatic temperatures (Tad). The difference between Tmax and Tad is explained by the prediction that transformation to the final intermetallic phases occurs after Tmax and results in the release of 20-30 % of the total heat of reaction and a delay in rapid cooling.

Barron, S. C.; Knepper, R.; Walker, N.; Weihs, T. P.

2011-01-11T23:59:59.000Z

109

Innovative Miniaturized Heat Pumps for Buildings: Modular Thermal Hub for Building Heating, Cooling and Water Heating  

SciTech Connect (OSTI)

BEETIT Project: Georgia Tech is using innovative components and system design to develop a new type of absorption heat pump. Georgia Tech’s new heat pumps are energy efficient, use refrigerants that do not emit greenhouse gases, and can run on energy from combustion, waste heat, or solar energy. Georgia Tech is leveraging enhancements to heat and mass transfer technology possible in microscale passages and removing hurdles to the use of heat-activated heat pumps that have existed for more than a century. Use of microscale passages allows for miniaturization of systems that can be packed as monolithic full-system packages or discrete, distributed components enabling integration into a variety of residential and commercial buildings. Compared to conventional heat pumps, Georgia Tech’s design innovations will create an absorption heat pump that is much smaller, has higher energy efficiency, and can also be mass produced at a lower cost and assembly time.

None

2010-09-01T23:59:59.000Z

110

Viscoelastic Models of Tidally Heated Exomoons  

E-Print Network [OSTI]

Tidal heating of exomoons may play a key role in their habitability, since the elevated temperature can melt the ice on the body even without significant solar radiation. The possibility of life is intensely studied on Solar System moons such as Europa or Enceladus, where the surface ice layer covers tidally heated water ocean. Tidal forces may be even stronger in extrasolar systems, depending on the properties of the moon and its orbit. For studying the tidally heated surface temperature of exomoons, we used a viscoelastic model for the first time. This model is more realistic than the widely used, so-called fixed Q models, because it takes into account the temperature dependency of the tidal heat flux, and the melting of the inner material. With the use of this model we introduced the circumplanetary Tidal Temperate Zone (TTZ), that strongly depends on the orbital period of the moon, and less on its radius. We compared the results with the fixed Q model and investigated the statistical volume of the TTZ usi...

Dobos, Vera

2015-01-01T23:59:59.000Z

111

Heat collector  

DOE Patents [OSTI]

A heat collector and method suitable for efficiently and cheaply collecting solar and other thermal energy are provided. The collector employs a heat pipe in a gravity-assist mode and is not evacuated. The collector has many advantages, some of which include ease of assembly, reduced structural stresses on the heat pipe enclosure, and a low total materials cost requirement. Natural convective forces drive the collector, which after startup operates entirely passively due in part to differences in molecular weights of gaseous components within the collector.

Merrigan, Michael A. (Santa Cruz, NM)

1984-01-01T23:59:59.000Z

112

Heat collector  

DOE Patents [OSTI]

A heat collector and method suitable for efficiently and cheaply collecting solar and other thermal energy are provided. The collector employs a heat pipe in a gravity-assist mode and is not evacuated. The collector has many advantages, some of which include ease of assembly, reduced structural stresses on the heat pipe enclosure, and a low total materials cost requirement. Natural convective forces drive the collector, which after startup operates entirely passively due in part to differences in molecular weights of gaseous components within the collector.

Merrigan, M.A.

1981-06-29T23:59:59.000Z

113

Corrosive resistant heat exchanger  

DOE Patents [OSTI]

A corrosive and errosive resistant heat exchanger which recovers heat from a contaminated heat stream. The heat exchanger utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat exchanger surface from the hot contaminated gas. The innocuous gas is conveyed through ducts or perforations in the heat exchanger wall. Heat from the heat stream is transferred by radiation to the heat exchanger wall. Heat is removed from the outer heat exchanger wall by a heat recovery medium.

Richlen, Scott L. (Annandale, VA)

1989-01-01T23:59:59.000Z

114

Impacts of Water Quality on Residential Water Heating Equipment  

SciTech Connect (OSTI)

Water heating is a ubiquitous energy use in all residential housing, accounting for 17.7% of residential energy use (EIA 2012). Today, there are many efficient water heating options available for every fuel type, from electric and gas to more unconventional fuel types like propane, solar, and fuel oil. Which water heating option is the best choice for a given household will depend on a number of factors, including average daily hot water use (total gallons per day), hot water draw patterns (close together or spread out), the hot water distribution system (compact or distributed), installation constraints (such as space, electrical service, or venting accommodations) and fuel-type availability and cost. While in general more efficient water heaters are more expensive than conventional water heating technologies, the savings in energy use and, thus, utility bills can recoup the additional upfront investment and make an efficient water heater a good investment over time in most situations, although the specific payback period for a given installation will vary widely. However, the expected lifetime of a water heater in a given installation can dramatically influence the cost effectiveness and savings potential of a water heater and should be considered, along with water use characteristics, fuel availability and cost, and specific home characteristics when selecting the optimum water heating equipment for a particular installation. This report provides recommendations for selecting and maintaining water heating equipment based on local water quality characteristics.

Widder, Sarah H.; Baechler, Michael C.

2013-11-01T23:59:59.000Z

115

Intrinsically irreversible heat engine  

DOE Patents [OSTI]

A class of heat engines based on an intrinsically irreversible heat transfer process is disclosed. In a typical embodiment the engine comprises a compressible fluid that is cyclically compressed and expanded while at the same time being driven in reciprocal motion by a positive displacement drive means. A second thermodynamic medium is maintained in imperfect thermal contact with the fluid and bears a broken thermodynamic symmetry with respect to the fluid. The second thermodynamic medium is a structure adapted to have a low fluid flow impedance with respect to the compressible fluid, and which is further adapted to be in only moderate thermal contact with the fluid. In operation, thermal energy is pumped along the second medium due to a phase lag between the cyclical heating and cooling of the fluid and the resulting heat conduction between the fluid and the medium. In a preferred embodiment the engine comprises an acoustical drive and a housing containing a gas which is driven at a resonant frequency so as to be maintained in a standing wave. Operation of the engine at acoustic frequencies improves the power density and coefficient of performance. The second thermodynamic medium can be coupled to suitable heat exchangers to utilize the engine as a simple refrigeration device having no mechanical moving parts. Alternatively, the engine is reversible in function so as to be utilizable as a prime mover by coupling it to suitable sources and sinks of heat. 11 figs.

Wheatley, J.C.; Swift, G.W.; Migliori, A.

1984-12-25T23:59:59.000Z

116

Intrinsically irreversible heat engine  

DOE Patents [OSTI]

A class of heat engines based on an intrinsically irreversible heat transfer process is disclosed. In a typical embodiment the engine comprises a compressible fluid that is cyclically compressed and expanded while at the same time being driven in reciprocal motion by a positive displacement drive means. A second thermodynamic medium is maintained in imperfect thermal contact with the fluid and bears a broken thermodynamic symmetry with respect to the fluid. the second thermodynamic medium is a structure adapted to have a low fluid flow impedance with respect to the compressible fluid, and which is further adapted to be in only moderate thermal contact with the fluid. In operation, thermal energy is pumped along the second medium due to a phase lag between the cyclical heating and cooling of the fluid and the resulting heat conduction between the fluid and the medium. In a preferred embodiment the engine comprises an acoustical drive and a housing containing a gas which is driven at a resonant frequency so as to be maintained in a standing wave. Operation of the engine at acoustic frequencies improves the power density and coefficient of performance. The second thermodynamic medium can be coupled to suitable heat exchangers to utilize the engine as a simple refrigeration device having no mechanical moving parts. Alternatively, the engine is reversible in function so as to be utilizable as a prime mover by coupling it to suitable sources and sinks of heat.

Wheatley, John C. (Los Alamos, NM); Swift, Gregory W. (Los Alamos, NM); Migliori, Albert (Santa Fe, NM)

1984-01-01T23:59:59.000Z

117

Intrinsically irreversible heat engine  

DOE Patents [OSTI]

A class of heat engines based on an intrinsically irreversible heat transfer process is disclosed. In a typical embodiment the engine comprises a compressible fluid that is cyclically compressed and expanded while at the same time being driven in reciprocal motion by a positive displacement drive means. A second thermodynamic medium is maintained in imperfect thermal contact with the fluid and bears a broken thermodynamic symmetry with respect to the fluid. The second thermodynamic medium is a structure adapted to have a low fluid flow impedance with respect to the compressible fluid, and which is further adapted to be in only moderate thermal contact with the fluid. In operation, thermal energy is pumped along the second medium due to a phase lag between the cyclical heating and cooling of the fluid and the resulting heat conduction between the fluid and the medium. In a preferred embodiment the engine comprises an acoustical drive and a housing containing a gas which is driven at a resonant frequency so as to be maintained in a standing wave. Operation of the engine at acoustic frequencies improves the power density and coefficient of performance. The second thermodynamic medium can be coupled to suitable heat exchangers to utilize the engine as a simple refrigeration device having no mechanical moving parts. Alternatively, the engine is reversible in function so as to be utilizable as a prime mover by coupling it to suitable sources and sinks of heat.

Wheatley, J.C.; Swift, G.W.; Migliori, A.

1984-01-01T23:59:59.000Z

118

Heating System Specification Specification of Heating System  

E-Print Network [OSTI]

Appendix A Heating System Specification /* Specification of Heating System (loosely based */ requestHeat : Room ­? bool; 306 #12; APPENDIX A. HEATING SYSTEM SPECIFICATION 307 /* user inputs */ livingPattern : Room ­? behaviour; setTemp : Room ­? num; heatSwitchOn, heatSwitchOff, userReset : simple

Day, Nancy

119

An analysis of periodic heat flow through a plane slab  

E-Print Network [OSTI]

slices of thickness ax = L/5 and. two half-slices of tJ:ickness ax/2 = L/10 as shown in I~'igure 1, and the center plane of eacn slice was indexed. o 1 (~6 X 2 nx i ax+ t t 0 DX bx Dx ~ax ? ~- Ax Dx ' CFOSS SECTION OP SLAB DIVID' 'D INTO SLIC... because it is always zero. tl t2 t5 t4 t. 0 1 2 5 6 1000. 0 1150. 5 1258. 8 1582. 6 1500. 0 1608, 7 1707. 1 0 200. 0 226. 1 $15. 8 561. 7 /t )8 0 0 80. 0 106. 4 160. 4 1 / 0 0 0 $2. 0 4o. 0 7'-' 1 0 0 0 0 12. 8 0 0 0 0 0...

Gibson, Daniel Morgan

1958-01-01T23:59:59.000Z

120

Techno-economic analysis of using corn stover to supply heat and power to a corn ethanol plant - Part 2: Cost of heat and power generation systems  

SciTech Connect (OSTI)

This paper presents a techno-economic analysis of corn stover fired process heating (PH) and the combined heat and power (CHP) generation systems for a typical corn ethanol plant (ethanol production capacity of 170 dam3). Discounted cash flow method was used to estimate both the capital and operating costs of each system and compared with the existing natural gas fired heating system. Environmental impact assessment of using corn stover, coal and natural gas in the heat and/or power generation systems was also evaluated. Coal fired process heating (PH) system had the lowest annual operating cost due to the low fuel cost, but had the highest environmental and human toxicity impacts. The proposed combined heat and power (CHP) generation system required about 137 Gg of corn stover to generate 9.5 MW of electricity and 52.3 MW of process heat with an overall CHP efficiency of 83.3%. Stover fired CHP system would generate an annual savings of 3.6 M$ with an payback period of 6 y. Economics of the coal fired CHP system was very attractive compared to the stover fired CHP system due to lower fuel cost. But the greenhouse gas emissions per Mg of fuel for the coal fired CHP system was 32 times higher than that of stover fired CHP system. Corn stover fired heat and power generation system for a corn ethanol plant can improve the net energy balance and add environmental benefits to the corn to ethanol biorefinery.

Mani, Sudhagar [University of Georgia; Sokhansanj, Shahabaddine [ORNL; Togore, Sam [U.S. Department of Energy; Turhollow Jr, Anthony F [ORNL

2010-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" 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

Waste-heat recovery in batch processes using heat storage  

SciTech Connect (OSTI)

The waste-heat recovery in batch processes has been studied using the pinch-point method. The aim of the work has been to investigate theoretical and practical approaches to the design of heat-exchanger networks, including heat storage, for waste-heat recovery in batch processes. The study is limited to the incorporation of energy-storage systems based on fixed-temperature variable-mass stores. The background for preferring this to the alternatives (variable-temperature fixed-mass and constant-mass constant-temperature (latent-heat) stores) is given. It is shown that the maximum energy-saving targets as calculated by the pinch-point method (time average model, TAM) can be achieved by locating energy stores at either end of each process stream. This theoretically large number of heat-storage tanks (twice the number of process streams) can be reduced to just a few tanks. A simple procedure for determining a number of heat-storage tanks sufficient to achieve the maximum energy-saving targets as calculated by the pinch-point method is described. This procedure relies on combinatorial considerations, and could therefore be labeled the combinatorial method for incorporation of heat storage in heat-exchanger networks. Qualitative arguments justifying the procedure are presented. For simple systems, waste-heat recovery systems with only three heat-storage temperatures (a hot storage, a cold storage, and a heat store at the pinch temperature) often can achieve the maximum energy-saving targets. Through case studies, six of which are presented, it is found that a theoretically large number of heat-storage tanks (twice the number of process streams) can be reduced to just a few tanks. The description of these six cases is intended to be sufficiently detailed to serve as benchmark cases for development of alternative methods.

Stoltze, S.; Mikkelsen, J.; Lorentzen, B.; Petersen, P.M.; Qvale, B. [Technical Univ. of Denmark, Lyngby (Denmark). Lab. for Energetics

1995-06-01T23:59:59.000Z

122

MEASUREMENT OF SPECIFIC HEAT CAPACITY OF SALTSTONE  

SciTech Connect (OSTI)

One of the goals of the Saltstone variability study is to identify (and quantify the impact of) the operational and compositional variables that control or influence the important processing and performance properties of Saltstone grout mixtures. The heat capacity of the Saltstone waste form is one of the important properties of Saltstone mixes that was last measured at SRNL in 1997. It is therefore important to develop a core competency for rapid and accurate analysis of the specific heat capacity of the Saltstone mixes in order to quantify the impact of compositional and operational variations on this property as part of the variability study. The heat capacity, coupled with the heat of hydration data obtained from isothermal calorimetry for a given Saltstone mix, can be used to predict the maximum temperature increase in the cells within the vaults of the Saltstone Disposal Facility (SDF). The temperature increase controls the processing rate and the pour schedule. The maximum temperature is also important to the performance properties of the Saltstone. For example, in mass pours of concrete or grout of which Saltstone is an example, the maximum temperature increase and the maximum temperature difference (between the surface and the hottest location) are controlled to ensure durability of the product and prevent or limit the cracking caused by the thermal gradients produced during curing. This report details the development and implementation of a method for the measurement of the heat capacities of Saltstone mixes as well as the heat capacities of the cementitious materials of the premix and the simulated salt solutions used to batch the mixes. The developed method utilizes the TAM Air isothermal calorimeter and takes advantage of the sophisticated heat flow measurement capabilities of the instrument. Standards and reference materials were identified and used to validate the procedure and ensure accuracy of testing. Heat capacities of Saltstone mixes were {approx} 55% higher than the previous measurement of specific heat capacity on a reference Saltstone mix in 1997. Values of mixes prepared using Deliquification, Dissolution and Adjustment (DDA), Modular Caustic Side Solvent Extraction Unit (MCU) and Salt Waste Processing Facility (SWPF) simulants and premix at 0.60 w/cm ratio were {approx} 1.95 J/g/{sup o}C and were equivalent within experimental error. The simple law of mixtures was used to predict the heat capacities of the Saltstone and the results were in excellent agreement with experimental data. This simple law of mixtures can therefore be used to predict the heat capacities of Saltstone mixes in those cases where measurements have not been made. The time dependence of the heat capacity is important as an input to the modeling of temperature increase in Saltstone vaults. The heat capacity of a mix of MCU and premix at 0.60 w/cm ratio was measured immediately after initial mixing and then periodically up to times greater than 100 days. Within experimental error, the heat capacity did not change with time. Therefore, the modeling is not complicated by requiring a time dependent function for specific heat capacity. The water to cementitious material (w/cm) ratio plays a key role in determining the value of the heat capacity. Both experimental and predictive values for SWPF mixes as function of the w/cm ratio were obtained and presented in this report. Predictions of the maximum temperatures of the Saltstone mixes were made using the heat of hydration data from previous isothermal measurements and the newly measured heat capacities for DDA, MCU and SWPF mixes. The maximum temperature increase ranged from 37 to 48 C for these mixes. The presence of aluminate at 0.33 M produced a temperature increase of 68 C which is close to the adiabatic temperature rise of 74 C observed by Steimke and Fowler in 1997 for a mix containing 0.35 M aluminate. Aluminum dissolution of the sludge will increase the aluminate in the DSS which in turn will result in a larger temperature increase in the Saltstone vaults during the curing p

Harbour, J; Vickie Williams, V

2008-09-29T23:59:59.000Z

123

Geothermal heating  

SciTech Connect (OSTI)

The aim of the study is to demonstrate the viability of geothermal heating projects in energy and economic terms and to provide nomograms from which an initial estimate may be made without having to use data-processing facilities. The effect of flow rate and temperature of the geothermal water on drilling and on the network, and the effect of climate on the type of housing are considered.

Aureille, M.

1982-01-01T23:59:59.000Z

124

ME 519: THEORY OF HEAT TRANSFER Instructor  

E-Print Network [OSTI]

ME 519: THEORY OF HEAT TRANSFER Fall 2014 Instructor: Class time: Classroom: Office Hours: Prof Tuesday 4­5pm or by appointment Class description This course will cover the fundamentals of heat transfer. An introductory course in heat transfer (ME 419 or equivalent) is pre-requisite. Grading 20% Homework 25% Exam 1

Lin, Xi

125

Heat pump system  

DOE Patents [OSTI]

An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchanges and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.

Swenson, Paul F. (Cleveland, OH); Moore, Paul B. (Fedhaurn, FL)

1982-01-01T23:59:59.000Z

126

Water and Space Heating Heat Pumps  

E-Print Network [OSTI]

This paper discusses the design and operation of the Trane Weathertron III Heat Pump Water Heating System and includes a comparison of features and performance to other domestic water heating systems. Domestic water is generally provided through...

Kessler, A. F.

1985-01-01T23:59:59.000Z

127

Industrial Waste Heat Recovery Using Heat Pipes  

E-Print Network [OSTI]

For almost a decade now, heat pipes with secondary finned surfaces have been utilized in counter flow heat exchangers to recover sensible energy from industrial exhaust gases. Over 3,000 such heat exchangers are now in service, recovering...

Ruch, M. A.

1981-01-01T23:59:59.000Z

128

Cab Heating and Cooling  

SciTech Connect (OSTI)

Schneider National, Inc., SNI, has concluded the Cab Heating and Cooling evaluation of onboard, engine off idling solutions. During the evaluation period three technologies were tested, a Webasto Airtronic diesel fired heater for cold weather operation, and two different approaches to cab cooling in warm weather, a Webasto Parking Cooler, phase change storage system and a Bergstrom Nite System, a 12 volt electrical air conditioning approach to cooling. Diesel fired cab heaters were concluded to provide adequate heat in winter environments down to 10 F. With a targeted idle reduction of 17%, the payback period is under 2 years. The Webasto Parking Cooler demonstrated the viability of this type of technology, but required significant driver involvement to achieve maximum performance. Drivers rated the technology as ''acceptable'', however, in individual discussions it became apparent they were not satisfied with the system limitations in hot weather, (over 85 F). The Bergstrom Nite system was recognized as an improvement by drivers and required less direct driver input to operate. While slightly improved over the Parking Cooler, the hot temperature limitations were only slightly better. Neither the Parking Cooler or the Nite System showed any payback potential at the targeted 17% idle reduction. Fleets who are starting at a higher idle baseline may have a more favorable payback.

Damman, Dennis

2005-10-31T23:59:59.000Z

129

Heating systems for heating subsurface formations  

DOE Patents [OSTI]

Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

Nguyen, Scott Vinh (Houston, TX); Vinegar, Harold J. (Bellaire, TX)

2011-04-26T23:59:59.000Z

130

Heating 7. 2 user's manual  

SciTech Connect (OSTI)

HEATING is a general-purpose conduction heat transfer program written in Fortran 77. HEATING can solve steady-state and/or transient heat conduction problems in one-, two-, or three-dimensional Cartesian, cylindrical, or spherical coordinates. A model may include multiple materials, and the thermal conductivity, density, and specific heat of each material may be both time- and temperature-dependent. The thermal conductivity may also be anisotropic. Materials may undergo change of phase. Thermal properties of materials may be input or may be extracted from a material properties library. Heat-generation rates may be dependent on time, temperature, and position, and boundary temperatures may be time- and position-dependent. The boundary conditions, which may be surface-to-environment or surface-to-surface, may be specified temperatures or any combination of prescribed heat flux, forced convection, natural convection, and radiation. The boundary condition parameters may be time- and/or temperature-dependent. General gray-body radiation problems may be modeled with user-defined factors for radiant exchange. The mesh spacing may be variable along each axis. HEATING uses a runtime memory allocation scheme to avoid having to recompile to match memory requirements for each specific problem. HEATING utilizes free-form input. Three steady-state solution techniques are available: point-successive-overrelaxation iterative method with extrapolation, direct-solution, and conjugate gradient. Transient problems may be solved using any one of several finite-difference schemes: Crank-Nicolson implicit, Classical Implicit Procedure (CIP), Classical Explicit Procedure (CEP), or Levy explicit method. The solution of the system of equations arising from the implicit techniques is accomplished by point-successive-overrelaxation iteration and includes procedures to estimate the optimum acceleration parameter.

Childs, K.W.

1993-02-01T23:59:59.000Z

131

Heat exchanger  

DOE Patents [OSTI]

A heat exchanger comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.

Brackenbury, P.J.

1983-12-08T23:59:59.000Z

132

Heat exchanger  

DOE Patents [OSTI]

A heat exchanger comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.

Brackenbury, Phillip J. (Richland, WA)

1986-01-01T23:59:59.000Z

133

PreHeat: Controlling Home Heating Using Occupancy Prediction  

E-Print Network [OSTI]

with a static program over an average 61 days per house, alternating days between these conditions time that the house was occupied but not warm). In US homes, PreHeat decreased MissTime by a factor goal for saving money and reducing our ecological footprint. Although programmable thermostats provide

Krumm, John

134

CONDUCTION HEAT TRANSFER Dr. Ruhul Amin Fall 2011  

E-Print Network [OSTI]

ME 525 CONDUCTION HEAT TRANSFER Dr. Ruhul Amin Fall 2011 Office: 201C Roberts Hall Lecture Room of conduction heat transfer. Important results which are useful for engineering application will also: 121 Roberts Hall Phone: 994-6295 Lecture Periods: 12:45- 2:00, TR TEXT: Heat Conduction, M. N. Ozisik

Dyer, Bill

135

Dual source heat pump  

DOE Patents [OSTI]

What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.

Ecker, Amir L. (Dallas, TX); Pietsch, Joseph A. (Dallas, TX)

1982-01-01T23:59:59.000Z

136

Segmented heat exchanger  

DOE Patents [OSTI]

A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

Baldwin, Darryl Dean (Lafayette, IN); Willi, Martin Leo (Dunlap, IL); Fiveland, Scott Byron (Metamara, IL); Timmons, Kristine Ann (Chillicothe, IL)

2010-12-14T23:59:59.000Z

137

DEVELOPMENT OF RASASASTRA IN MEDIEVAL PERIOD*  

E-Print Network [OSTI]

ABSTRACT: The paper deals with the historical development of Rasasastra in Medieval period. Knowledge of Rasa has been in existence from the time immemorial. Exploration of natural resources for the benefit of human beings is the object of this therapy. It is a medical science recognized during vedic periods for the betterment of even Devas. Medieval period can be treated as a golden age for the development of this science. Looking at its aim and objects, methodology and therapeutics, it was recognized as a medical science with an independent philosophical background in 14 th century, by Madhavacharya in his Sarva Darsana Samgraha.

Harishankar Sharma

1984-01-01T23:59:59.000Z

138

The onset of ion heating during magnetic reconnection with a strong guide field  

SciTech Connect (OSTI)

The onset of the acceleration of ions during magnetic reconnection is explored via particle-in-cell simulations in the limit of a strong ambient guide field that self-consistently and simultaneously follow the motions of protons and ? particles. Heating parallel to the local magnetic field during reconnection with a guide field is strongly reduced compared with the reconnection of anti-parallel magnetic fields. The dominant heating of thermal ions during guide field reconnection results from pickup behavior of ions during their entry into reconnection exhausts and dominantly produces heating perpendicular rather than parallel to the local magnetic field. Pickup behavior requires that the ion transit time across the exhaust boundary (with a transverse scale of the order of the ion sound Larmor radius) be short compared with the ion cyclotron period. This translates into a threshold in the strength of reconnecting magnetic field that favors the heating of ions with high mass-to-charge. A simulation with a broad initial current layer produces a reconnecting system in which the amplitude of the reconnecting magnetic field just upstream of the dissipation region increases with time as reconnection proceeds. The sharp onset of perpendicular heating when the pickup threshold is crossed is documented. A comparison of the time variation of the parallel and perpendicular ion heating with that predicted based on the strength of the reconnecting field establishes the scaling of ion heating with ambient parameters both below and above the pickup threshold. The relevance to observations of ion heating in the solar corona is discussed.

Drake, J. F., E-mail: drake@umd.edu [Space Science Laboratory, University of California, Berkeley, California 94720 (United States); Swisdak, M., E-mail: swisdak@umd.edu [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States)

2014-07-15T23:59:59.000Z

139

Multiple source heat pump  

DOE Patents [OSTI]

A heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating a fluid in heat exchange relationship with a refrigerant fluid, at least three refrigerant heat exchangers, one for effecting heat exchange with the fluid, a second for effecting heat exchange with a heat exchange fluid, and a third for effecting heat exchange with ambient air; a compressor for compressing the refrigerant; at least one throttling valve connected at the inlet side of a heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circuit and pump for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and directional flow of refrigerant therethrough for selecting a particular mode of operation. Also disclosed are a variety of embodiments, modes of operation, and schematics therefor.

Ecker, Amir L. (Duncanville, TX)

1983-01-01T23:59:59.000Z

140

A Functional Regression Approach for Prediction in a District-Heating System  

E-Print Network [OSTI]

A Functional Regression Approach for Prediction in a District-Heating System Aldo Goia Dipartimento in a district heating sys- tem. Our dataset consists of four separated periods, with 198 days each period and 24 load forecasting, district heat- ing system Introduction Among the activities of support

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "time period heating" 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

Heat Pump for High School Heat Recovery  

E-Print Network [OSTI]

The heat pump system used for recycling and reusing waste heat in s high school bathroom was minutely analyzed in its coefficient of performance, onetime utilization ratio of energy, economic property and so on. The results showed that this system...

Huang, K.; Wang, H.; Zhou, X.

2006-01-01T23:59:59.000Z

142

Combined Heat and Power, Waste Heat, and District Energy | Department...  

Broader source: Energy.gov (indexed) [DOE]

Combined Heat and Power, Waste Heat, and District Energy Combined Heat and Power, Waste Heat, and District Energy Presentation-given at the Fall 2011 Federal Utility Partnership...

143

Project Profile: Heat Transfer and Latent Heat Storage in Inorganic...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for CSP Plants Project Profile: Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for CSP Plants...

144

Pagosa Springs District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

Pagosa Springs District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Pagosa Springs District Heating District Heating Low...

145

Kethcum District Heating District Heating Low Temperature Geothermal...  

Open Energy Info (EERE)

Kethcum District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Kethcum District Heating District Heating Low Temperature Geothermal...

146

Midland District Heating District Heating Low Temperature Geothermal...  

Open Energy Info (EERE)

Midland District Heating District Heating Low Temperature Geothermal Facility Facility Midland District Heating Sector Geothermal energy Type District Heating Location Midland,...

147

San Bernardino District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

San Bernardino District Heating District Heating Low Temperature Geothermal Facility Facility San Bernardino District Heating Sector Geothermal energy Type District Heating...

148

Philip District Heating District Heating Low Temperature Geothermal...  

Open Energy Info (EERE)

Philip District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Philip District Heating District Heating Low Temperature Geothermal...

149

Absorption heat pump system  

DOE Patents [OSTI]

The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

Grossman, G.

1982-06-16T23:59:59.000Z

150

Locating Heat Recovery Opportunities  

E-Print Network [OSTI]

Basic concepts of heat recovery are defined as they apply to the industrial community. Methods for locating, ranking, and developing heat recovery opportunities are presented and explained. The needs for useful heat 'sinks' are emphasized as equal...

Waterland, A. F.

1981-01-01T23:59:59.000Z

151

Absorption heat pump system  

DOE Patents [OSTI]

The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

Grossman, Gershon (Oak Ridge, TN)

1984-01-01T23:59:59.000Z

152

Climate, extreme heat, and electricity demand in California  

SciTech Connect (OSTI)

Climate projections from three atmosphere-ocean climate models with a range of low to mid-high temperature sensitivity forced by the Intergovernmental Panel for Climate Change SRES higher, middle, and lower emission scenarios indicate that, over the 21st century, extreme heat events for major cities in heavily air-conditioned California will increase rapidly. These increases in temperature extremes are projected to exceed the rate of increase in mean temperature, along with increased variance. Extreme heat is defined here as the 90 percent exceedance probability (T90) of the local warmest summer days under the current climate. The number of extreme heat days in Los Angeles, where T90 is currently 95 F (32 C), may increase from 12 days to as many as 96 days per year by 2100, implying current-day heat wave conditions may last for the entire summer, with earlier onset. Overall, projected increases in extreme heat under the higher A1fi emission scenario by 2070-2099 tend to be 20-30 percent higher than those projected under the lower B1 emission scenario, ranging from approximately double the historical number of days for inland California cities (e.g. Sacramento and Fresno), up to four times for previously temperate coastal cities (e.g. Los Angeles, San Diego). These findings, combined with observed relationships between high temperature and electricity demand for air-conditioned regions, suggest potential shortfalls in transmission and supply during T90 peak electricity demand periods. When the projected extreme heat and peak demand for electricity are mapped onto current availability, maintaining technology and population constant only for demand side calculations, we find the potential for electricity deficits as high as 17 percent. Similar increases in extreme heat days are suggested for other locations across the U.S. southwest, as well as for developing nations with rapidly increasing electricity demands. Electricity response to recent extreme heat events, such as the July 2006 heat wave in California, suggests that peak electricity demand will challenge current supply, as well as future planned supply capacities when population and income growth are taken into account.

Miller, N.L.; Hayhoe, K.; Jin, J.; Auffhammer, M.

2008-04-01T23:59:59.000Z

153

Woven heat exchanger  

DOE Patents [OSTI]

This invention relates to a heat exchanger for waste heat recovery from high temperature industrial exhaust streams. In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.

Piscitella, R.R.

1984-07-16T23:59:59.000Z

154

HEATING 7. 1 user's manual  

SciTech Connect (OSTI)

HEATING is a FORTRAN program designed to solve steady-state and/or transient heat conduction problems in one-, two-, or three- dimensional Cartesian, cylindrical, or spherical coordinates. A model may include multiple materials, and the thermal conductivity, density, and specific heat of each material may be both time- and temperature-dependent. The thermal conductivity may be anisotropic. Materials may undergo change of phase. Thermal properties of materials may be input or may be extracted from a material properties library. Heating generation rates may be dependent on time, temperature, and position, and boundary temperatures may be time- and position-dependent. The boundary conditions, which may be surface-to-boundary or surface-to-surface, may be specified temperatures or any combination of prescribed heat flux, forced convection, natural convection, and radiation. The boundary condition parameters may be time- and/or temperature-dependent. General graybody radiation problems may be modeled with user-defined factors for radiant exchange. The mesh spacing may be variable along each axis. HEATING is variably dimensioned and utilizes free-form input. Three steady-state solution techniques are available: point-successive-overrelaxation iterative method with extrapolation, direct-solution (for one-dimensional or two-dimensional problems), and conjugate gradient. Transient problems may be solved using one of several finite-difference schemes: Crank-Nicolson implicit, Classical Implicit Procedure (CIP), Classical Explicit Procedure (CEP), or Levy explicit method (which for some circumstances allows a time step greater than the CEP stability criterion). The solution of the system of equations arising from the implicit techniques is accomplished by point-successive-overrelaxation iteration and includes procedures to estimate the optimum acceleration parameter.

Childs, K.W.

1991-07-01T23:59:59.000Z

155

Total Space Heat-  

Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

Commercial Buildings Energy Consumption Survey: Energy End-Use Consumption Tables Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration...

156

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

Revised: December, 2008 Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other All Buildings...

157

Towards Intelligent District Heating.  

E-Print Network [OSTI]

??A district heating system consists of one or more production units supplying energy in the form of heated water through a distribution pipe network to… (more)

Johansson, Christian

2010-01-01T23:59:59.000Z

158

Winter Heating Fuels Update  

Gasoline and Diesel Fuel Update (EIA)

Heating Fuels Update For: Congressional Briefings October 20, 2014 | Washington, DC By U.S. Energy Information Administration Winter Heating Fuels Update October 20, 2014 |...

159

A batch reactor heat recovery challenge problem Johannes Jschke, Sigurd Skogestad  

E-Print Network [OSTI]

A batch reactor heat recovery challenge problem Johannes Jäschke, Sigurd Skogestad Department a challenge problem for maximizing the heat recovery in a heat exchanger network connected to a set of batch periods of the batch reactors, the reactor effluents are fed into the secondary sides of the heat

Skogestad, Sigurd

160

Quantum transport calculations using periodic boundaryconditions  

SciTech Connect (OSTI)

An efficient new method is presented to calculate the quantum transports using periodic boundary conditions. This method allows the use of conventional ground state ab initio programs without big changes. The computational effort is only a few times of a normal groundstate calculations, thus is makes accurate quantum transport calculations for large systems possible.

Wang, Lin-Wang

2004-06-15T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" 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

Diffusive propagation of wave packets in a fluctuating periodic potential  

E-Print Network [OSTI]

We consider the evolution of a tight binding wave packet propagating in a fluctuating periodic potential. If the fluctuations stem from a stationary Markov process satisfying certain technical criteria, we show that the square amplitude of the wave packet after diffusive rescaling converges to a superposition of solutions of a heat equation.

Eman Hamza; Yang Kang; Jeffrey Schenker

2010-10-05T23:59:59.000Z

162

The evaluation of a 4000-home geothermal heat pump retrofit at Fort Polk, Louisiana: Final Report  

SciTech Connect (OSTI)

This report documents an independent evaluation of an energy retrofit of 4,003 family housing units at Fort Polk, Louisiana, under an energy savings performance contract (ESPC). Replacement of the heating, cooling, and water heating systems in these housing units with geothermal heat pumps (GHPs) anchored the retrofit; low-flow shower heads and compact fluorescent lighting were also installed, as well as attic insulation where needed. Statistically valid findings indicate that the project will save 25.8 million kWh, or 32.5% of the pre-retrofit whole-community electrical consumption, and 100% of the whole-community natural gas previously used for space conditioning and water heating (260,000 therms) in a typical meteorological year. At the end-use level, the GHPs were found to save about 42% of the pre-retrofit electrical consumption for heating, cooling, and water heating in housing units that were all-electric in the pre-retrofit period. This report also demonstrates an improved method of predicting energy savings. Using an engineering model calibrated to pre-retrofit energy use data collected in the field, the method predicted actual energy savings on one of the electric feeders at Fort Polk with a very high degree of accuracy. The accuracy of this model was in turn dependent on data-calibrated models of the geothermal heat pump and ground heat exchanger that are described in this report. In addition this report documents the status of vertical borehole ground heat exchanger (BHEx) design methods at the time this project was designed, and demonstrates methods of using data collected from operating GHP systems to benchmark BHEx design methods against a detailed engineering model calibrated to date. The authors also discuss the ESPC`s structure and implementation and how the experience gained here can contribute to the success of future ESPCs.

Hughes, P.J.; Shonder, J.A.

1998-03-01T23:59:59.000Z

163

Electrically heated DPF start-up strategy  

DOE Patents [OSTI]

An exhaust system that processes exhaust generated by an engine has a diesel particulate filter (DPF) that is disposed downstream of the engine and that filters particulates in the exhaust. An electrical heater is disposed upstream of the DPF and selectively heats the exhaust to initiate combustion of the particulates. Heat generated by combustion of particulates in the heater induces combustion of particulates within the DPF. A control module selectively enables current flow to the electrical heater for an initial period of a DPF regeneration cycle, and limits exhaust flow while the electrical heater is heating to a predetermined soot combustion temperature.

Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

2012-04-10T23:59:59.000Z

164

The integration of water loop heat pump and building structural thermal storage systems  

SciTech Connect (OSTI)

Many commercial buildings need heat in one part and, at the same time, cooling in another part. Even more common is the need for heating during one part of the day and cooling during another in the same spaces. If that energy could be shifted or stored for later use, significant energy might be saved. If a building's heating and cooling subsystems could be integrated with the building's structural mass and used to collect, store, and deliver energy, the energy might be save cost-effectively. To explore this opportunity, researchers at the Pacific Northwest Laboratory (PNL) examined the thermal interactions between the heating, ventilating, and air-conditioning (HVAC) system and the structure of a commercial building. Computer models were developed to simulate the interactions in an existing building located in Seattle, Washington, to determine how these building subsystems could be integrated to improve energy efficiency. The HVAC subsystems in the existing building were modeled. These subsystems consist of decentralized water-source heat pumps (WSHP) in a closed water loop, connected to cooling towers for heat rejection during cooling mode and boilers to augment heating. An initial base case'' computer model of the Seattle building, as-built, was developed. Metered data available for the building were used to calibrate this model to ensure that the analysis would provide information that closely reflected the operation of a real building. The HVAC system and building structure were integrated in the model using the concrete floor slabs as thermal storage media. The slabs may be actively charged during off-peak periods with the chilled water in the loop and then either actively or passively discharged into the conditioned space during peak periods. 21 refs., 37 figs., 17 tabs.

Marseille, T.J.; Schliesing, J.S.

1991-10-01T23:59:59.000Z

165

No. 2 heating oil/propane program  

SciTech Connect (OSTI)

During the 1990/91 heating season, the Massachusetts Division of Energy Resources (DOER) participated in a joint data collection program between several state energy offices and the federal Department of Energy's (DOE) Energy Information Administration (EIA). The purpose of the program was to collect and monitor retail and wholesale heating oil and propane prices and inventories from October 1990 through March 1991. This final report begins with an overview of the unique events which had an impact on the reporting period. Next, the report summarizes the results from the residential heating oil and propane price surveys conducted by DOER over the 1990/91 heating season. The report also incorporates the wholesale heating oil and propane prices and inventories collected by the EIA and distributed to the states.

McBrien, J.

1991-06-01T23:59:59.000Z

166

Evaluation of Waste Heat Recovery and Utilization from Residential Appliances and Fixtures  

SciTech Connect (OSTI)

Executive Summary In every home irrespective of its size, location, age, or efficiency, heat in the form of drainwater or dryer exhaust is wasted. Although from a waste stream, this energy has the potential for being captured, possibly stored, and then reused for preheating hot water or air thereby saving operating costs to the homeowner. In applications such as a shower and possibly a dryer, waste heat is produced at the same time as energy is used, so that a heat exchanger to capture the waste energy and return it to the supply is all that is needed. In other applications such as capturing the energy in drainwater from a tub, dishwasher, or washing machine, the availability of waste heat might not coincide with an immediate use for energy, and consequently a heat exchanger system with heat storage capacity (i.e. a regenerator) would be necessary. This study describes a two-house experimental evaluation of a system designed to capture waste heat from the shower, dishwasher clothes washer and dryer, and to use this waste heat to offset some of the hot water energy needs of the house. Although each house was unoccupied, they were fitted with equipment that would completely simulate the heat loads and behavior of human occupants including operating the appliances and fixtures on a demand schedule identical to Building American protocol (Hendron, 2009). The heat recovery system combined (1) a gravity-film heat exchanger (GFX) installed in a vertical section of drainline, (2) a heat exchanger for capturing dryer exhaust heat, (3) a preheat tank for storing the captured heat, and (4) a small recirculation pump and controls, so that the system could be operated anytime that waste heat from the shower, dishwasher, clothes washer and dryer, and in any combination was produced. The study found capturing energy from the dishwasher and clothes washer to be a challenge since those two appliances dump waste water over a short time interval. Controls based on the status of the dump valve on these two appliances would have eliminated uncertainty in knowing when waste water was flowing and the recovery system operated. The study also suggested that capture of dryer exhaust heat to heat incoming air to the dryer should be examined as an alternative to using drying exhaust energy for water heating. The study found that over a 6-week test period, the system in each house was able to recover on average approximately 3000 W-h of waste heat daily from these appliance and showers with slightly less on simulated weekdays and slightly more on simulated weekends which were heavy wash/dry days. Most of these energy savings were due to the shower/GFX operation, and the least savings were for the dishwasher/GFX operation. Overall, the value of the 3000 W-h of displaced energy would have been $0.27/day based on an electricity price of $.09/kWh. Although small for today s convention house, these savings are significant for a home designed to approach maximum affordable efficiency where daily operating costs for the whole house are less than a dollar per day. In 2010 the actual measured cost of energy in one of the simulated occupancy houses which waste heat recovery testing was undertaken was $0.77/day.

Tomlinson, John J [ORNL; Christian, Jeff [Oak Ridge National Laboratory (ORNL); Gehl, Anthony C [ORNL

2012-09-01T23:59:59.000Z

167

Finite Volume Based Computer Program for Ground Source Heat Pump System  

SciTech Connect (OSTI)

This report is a compilation of the work that has been done on the grant DE-EE0002805 entitled ?Finite Volume Based Computer Program for Ground Source Heat Pump Systems.? The goal of this project was to develop a detailed computer simulation tool for GSHP (ground source heat pump) heating and cooling systems. Two such tools were developed as part of this DOE (Department of Energy) grant; the first is a two-dimensional computer program called GEO2D and the second is a three-dimensional computer program called GEO3D. Both of these simulation tools provide an extensive array of results to the user. A unique aspect of both these simulation tools is the complete temperature profile information calculated and presented. Complete temperature profiles throughout the ground, casing, tube wall, and fluid are provided as a function of time. The fluid temperatures from and to the heat pump, as a function of time, are also provided. In addition to temperature information, detailed heat rate information at several locations as a function of time is determined. Heat rates between the heat pump and the building indoor environment, between the working fluid and the heat pump, and between the working fluid and the ground are computed. The heat rates between the ground and the working fluid are calculated as a function time and position along the ground loop. The heating and cooling loads of the building being fitted with a GSHP are determined with the computer program developed by DOE called ENERGYPLUS. Lastly COP (coefficient of performance) results as a function of time are provided. Both the two-dimensional and three-dimensional computer programs developed as part of this work are based upon a detailed finite volume solution of the energy equation for the ground and ground loop. Real heat pump characteristics are entered into the program and used to model the heat pump performance. Thus these computer tools simulate the coupled performance of the ground loop and the heat pump. The price paid for the three-dimensional detail is the large computational times required with GEO3D. The computational times required for GEO2D are reasonable, a few minutes for a 20 year simulation. For a similar simulation, GEO3D takes days of computational time. Because of the small simulation times with GEO2D, a number of attractive features have been added to it. GEO2D has a user friendly interface where inputs and outputs are all handled with GUI (graphical user interface) screens. These GUI screens make the program exceptionally easy to use. To make the program even easier to use a number of standard input options for the most common GSHP situations are provided to the user. For the expert user, the option still exists to enter their own detailed information. To further help designers and GSHP customers make decisions about a GSHP heating and cooling system, cost estimates are made by the program. These cost estimates include a payback period graph to show the user where their GSHP system pays for itself. These GSHP simulation tools should be a benefit to the advancement of GSHP systems.

Menart, James A. [Wright State University

2013-02-22T23:59:59.000Z

168

Recovery Act: Finite Volume Based Computer Program for Ground Source Heat Pump Systems  

SciTech Connect (OSTI)

This report is a compilation of the work that has been done on the grant DE-EE0002805 entitled ���¢��������Finite Volume Based Computer Program for Ground Source Heat Pump Systems.���¢������� The goal of this project was to develop a detailed computer simulation tool for GSHP (ground source heat pump) heating and cooling systems. Two such tools were developed as part of this DOE (Department of Energy) grant; the first is a two-dimensional computer program called GEO2D and the second is a three-dimensional computer program called GEO3D. Both of these simulation tools provide an extensive array of results to the user. A unique aspect of both these simulation tools is the complete temperature profile information calculated and presented. Complete temperature profiles throughout the ground, casing, tube wall, and fluid are provided as a function of time. The fluid temperatures from and to the heat pump, as a function of time, are also provided. In addition to temperature information, detailed heat rate information at several locations as a function of time is determined. Heat rates between the heat pump and the building indoor environment, between the working fluid and the heat pump, and between the working fluid and the ground are computed. The heat rates between the ground and the working fluid are calculated as a function time and position along the ground loop. The heating and cooling loads of the building being fitted with a GSHP are determined with the computer program developed by DOE called ENERGYPLUS. Lastly COP (coefficient of performance) results as a function of time are provided. Both the two-dimensional and three-dimensional computer programs developed as part of this work are based upon a detailed finite volume solution of the energy equation for the ground and ground loop. Real heat pump characteristics are entered into the program and used to model the heat pump performance. Thus these computer tools simulate the coupled performance of the ground loop and the heat pump. The price paid for the three-dimensional detail is the large computational times required with GEO3D. The computational times required for GEO2D are reasonable, a few minutes for a 20 year simulation. For a similar simulation, GEO3D takes days of computational time. Because of the small simulation times with GEO2D, a number of attractive features have been added to it. GEO2D has a user friendly interface where inputs and outputs are all handled with GUI (graphical user interface) screens. These GUI screens make the program exceptionally easy to use. To make the program even easier to use a number of standard input options for the most common GSHP situations are provided to the user. For the expert user, the option still exists to enter their own detailed information. To further help designers and GSHP customers make decisions about a GSHP heating and cooling system, cost estimates are made by the program. These cost estimates include a payback period graph to show the user where their GSHP system pays for itself. These GSHP simulation tools should be a benefit to the advancement of GSHP system

James A Menart, Professor

2013-02-22T23:59:59.000Z

169

Accidental Burning of a Fuel Layer on a Waterbed: A Scale Analysis Study of the Heat Transfer Models Predicting the pre-Boilover Time and Scaling to Published Data   

E-Print Network [OSTI]

The paper concerns the heat transfer models of liquid fuel bed burning on water sublayer. The main efforts are stressed on the qualitative assessment of models available and their adequacy as well as on the prediction of ...

Hristov, J; Planas, E; Arnaldos, J; Casal, J

170

Heat pipes for use in a magnetic field  

DOE Patents [OSTI]

A heat pipe configuration for use in a magnetic field environment of a fusion reactor is disclosed. Heat pipes for operation in a magnetic field when liquid metal working fluids are used are optimized by flattening of the heat pipes having an unobstructed annulus which significantly reduces the adverse side region effect of the prior known cylindrically configured heat pipes. The flattened heat pipes operating in a magnetic field can remove 2--3 times the heat as a cylindrical heat pipe of the same cross sectional area. 4 figs.

Werner, R.W.; Hoffman, M.A.

1983-07-19T23:59:59.000Z

171

Rotary magnetic heat pump  

DOE Patents [OSTI]

A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.

Kirol, L.D.

1987-02-11T23:59:59.000Z

172

Mass and Heat Recovery  

E-Print Network [OSTI]

In the last few years heat recovery was under spot and in air conditioning fields usually we use heat recovery by different types of heat exchangers. The heat exchanging between the exhaust air from the building with the fresh air to the building...

Hindawai, S. M.

2010-01-01T23:59:59.000Z

173

Direct fired heat exchanger  

SciTech Connect (OSTI)

A gas-to-liquid heat exchanger system which transfers heat from a gas, generally the combustion gas of a direct-fired generator of an absorption machine, to a liquid, generally an absorbent solution. The heat exchanger system is in a counterflow fluid arrangement which creates a more efficient heat transfer.

Reimann, Robert C. (Lafayette, NY); Root, Richard A. (Spokane, WA)

1986-01-01T23:59:59.000Z

174

Rotary magnetic heat pump  

DOE Patents [OSTI]

A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation.

Kirol, Lance D. (Shelly, ID)

1988-01-01T23:59:59.000Z

175

Embedding a chaotic signature in a periodic train: can periodic signals be chaotic?  

E-Print Network [OSTI]

We show how a chaotic system can be locked to emit a periodic waveform belonging to its chaotic attractor. We numerically demonstrate our idea in a system composed of a semiconductor laser driven to chaos by optical feedback from a short external cavity. The clue is the injection of an appropriate periodic signal that modulates the phase and amplitude of the intra-cavity radiation, a chaotic analogy of conventional mode-locking. The result is a time process that manifests a chaotic signature embedded in a long-scale periodic train.

Antonio Mecozzi; Cristian Antonelli

2008-12-11T23:59:59.000Z

176

Thulium-170 heat source  

DOE Patents [OSTI]

An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

Walter, Carl E. (Pleasanton, CA); Van Konynenburg, Richard (Livermore, CA); VanSant, James H. (Tracy, CA)

1992-01-01T23:59:59.000Z

177

Heat Treating Apparatus  

DOE Patents [OSTI]

Apparatus for heat treating a heat treatable material including a housing having an upper opening for receiving a heat treatable material at a first temperature, a lower opening, and a chamber therebetween for heating the heat treatable material to a second temperature higher than the first temperature as the heat treatable material moves through the chamber from the upper to the lower opening. A gas supply assembly is operatively engaged to the housing at the lower opening, and includes a source of gas, a gas delivery assembly for delivering the gas through a plurality of pathways into the housing in countercurrent flow to movement of the heat treatable material, whereby the heat treatable material passes through the lower opening at the second temperature, and a control assembly for controlling conditions within the chamber to enable the heat treatable material to reach the second temperature and pass through the lower opening at the second temperature as a heated material.

De Saro, Robert (Annandale, NJ); Bateman, Willis (Sutton Colfield, GB)

2002-09-10T23:59:59.000Z

178

Heat transfer education : Keeping it relevant and vibrant.  

SciTech Connect (OSTI)

The motivation for a fresh look at heat transfer education, both in content and in methodology, is generated by a number of trends in engineering practice. These include the increasing demand for engineers with interdisciplinary skills, rapid integration of technology, emergence of computerized and interactive problem-solving tools, shortening time of concept-to-market, availability of new technologies, and an increasing number of new or redesigned products and processes in which heat transfer plays a part. Examination of heat transfer education in this context can be aided by considering the changes, both qualitatively and quantitatively, in the student, educator, and researcher populations, employment opportunities, in the needs of corporations, government, industry, and universities, and in the relevant technical problems and issues of the day. Such an overview provides the necessary background for charting a response to the difficult question of how to maintain excellence and continuity in heat transfer education in the face of rapid, widespread, and complex changes. The present paper addresses how to make heat transfer education more relevant and stimulating. This paper represents a written summary of a 1996 panel discussion at the 1996 International Mechanical Engineering Conference and Exhibition (IMECE) of the American Society of Mechanical Engineers (ASME) in Atlanta, Georgia, on ''Heat Transfer Education: Keeping it Relevant and Vibrant,'' with significant expansion and amplification by the authors and the panelists in the 1997-98 period. The consensus of the participants is that the steps necessary to ensure the desired outcome in heat transfer education should include: (1) a better understanding of the interaction between the student, course content, and market needs; (2) an appreciation of the need in multidisciplinary industrial environments for engineers trained with a broad background: (3) a revision of the introductory heat transfer course to incorporate illustrative and insightful industrial examples and case studies reducible to order-of-magnitude analyses; (4) a reinforcement of real-world problem-solving abilities in students by introducing them to examples that emphasize multidisciplinary issues in modern thermal management problems and finally (5) industrial collaboration that would provide the educator with meaningful thermal management case studies (and possible funding), the student with an appreciation of industrial practices, and the industrial sponsor with access to academia for assistance in problem solving. Also suggested is an effective regular review program to provide assessment, feedback, and suggestions for quality control to interested institutions on their teaching methodology and materials.

Khounsary, A. M.

1998-08-14T23:59:59.000Z

179

Thermoelectric heat exchange element  

DOE Patents [OSTI]

A thermoelectric heat exchange module includes a first substrate including a heat receptive side and a heat donative side and a series of undulatory pleats. The module may also include a thermoelectric material layer having a ZT value of 1.0 or more disposed on at least one of the heat receptive side and the heat donative side, and an electrical contact may be in electrical communication with the thermoelectric material layer.

Callas, James J. (Peoria, IL); Taher, Mahmoud A. (Peoria, IL)

2007-08-14T23:59:59.000Z

180

Heat Integrate Heat Engines in Process Plants  

E-Print Network [OSTI]

of forcing a good fit between a heat engine and process T', H profiles extends the ideas of appropriate and inappropriate placement to give bet ter overall integration schemes [7] . The new 'and powerful representations of the thermodynamics of a process... HEAT INTEGRATE HEAT ENGINES IN PROCESS PLANTS E. Hindmarsh, D. Boland and D.W. Townsend TENSA Technology, Houston, Texas Shorter Version Appeared in Chemical Engineering Copyright McGraw Hill, 1985 ABSTRACT This paper presents a novel method...

Hindmarsh, E.; Boland, D.; Townsend, D. W.

Note: This page contains sample records for the topic "time period heating" 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

Modeling a Printed Circuit Heat Exchanger with RELAP5-3D for the Next Generation Nuclear Plant  

SciTech Connect (OSTI)

The main purpose of this report is to design a printed circuit heat exchanger (PCHE) for the Next Generation Nuclear Plant and carry out Loss of Coolant Accident (LOCA) simulation using RELAP5-3D. Helium was chosen as the coolant in the primary and secondary sides of the heat exchanger. The design of PCHE is critical for the LOCA simulations. For purposes of simplicity, a straight channel configuration was assumed. A parallel intermediate heat exchanger configuration was assumed for the RELAP5 model design. The RELAP5 modeling also required the semicircular channels in the heat exchanger to be mapped to rectangular channels. The initial RELAP5 run outputs steady state conditions which were then compared to the heat exchanger performance theory to ensure accurate design is being simulated. An exponential loss of pressure transient was simulated. This LOCA describes a loss of coolant pressure in the primary side over a 20 second time period. The results for the simulation indicate that heat is initially transferred from the primary loop to the secondary loop, but after the loss of pressure occurs, heat transfers from the secondary loop to the primary loop.

Not Available

2010-12-01T23:59:59.000Z

182

Passive ice freezing-releasing heat pipe  

DOE Patents [OSTI]

A heat pipe device has been developed which permits completely passive ice formation and periodic release of ice without requiring the ambient temperature to rise above the melting point of water. This passive design enables the maximum amount of cooling capacity to be stored in the tank.

Gorski, Anthony J. (Lemont, IL); Schertz, William W. (Batavia, IL)

1982-01-01T23:59:59.000Z

183

Optimal joule heating of the subsurface  

DOE Patents [OSTI]

A method for simultaneously heating the subsurface and imaging the effects of the heating is disclosed. This method combines the use of tomographic imaging (electrical resistance tomography or ERT) to image electrical resistivity distribution underground, with joule heating by electrical currents injected in the ground. A potential distribution is established on a series of buried electrodes resulting in energy deposition underground which is a function of the resistivity and injection current density. Measurement of the voltages and currents also permits a tomographic reconstruction of the resistivity distribution. Using this tomographic information, the current injection pattern on the driving electrodes can be adjusted to change the current density distribution and thus optimize the heating. As the heating changes conditions, the applied current pattern can be repeatedly adjusted (based on updated resistivity tomographs) to affect real time control of the heating.

Berryman, J.G.; Daily, W.D.

1994-07-05T23:59:59.000Z

184

Optimal joule heating of the subsurface  

DOE Patents [OSTI]

A method for simultaneously heating the subsurface and imaging the effects of the heating. This method combines the use of tomographic imaging (electrical resistance tomography or ERT) to image electrical resistivity distribution underground, with joule heating by electrical currents injected in the ground. A potential distribution is established on a series of buried electrodes resulting in energy deposition underground which is a function of the resistivity and injection current density. Measurement of the voltages and currents also permits a tomographic reconstruction of the resistivity distribution. Using this tomographic information, the current injection pattern on the driving electrodes can be adjusted to change the current density distribution and thus optimize the heating. As the heating changes conditions, the applied current pattern can be repeatedly adjusted (based on updated resistivity tomographs) to affect real time control of the heating.

Berryman, James G. (Danville, CA); Daily, William D. (Livermore, CA)

1994-01-01T23:59:59.000Z

185

Cloud Properties and Radiative Heating Rates for TWP  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

A cloud properties and radiative heating rates dataset is presented where cloud properties retrieved using lidar and radar observations are input into a radiative transfer model to compute radiative fluxes and heating rates at three ARM sites located in the Tropical Western Pacific (TWP) region. The cloud properties retrieval is a conditional retrieval that applies various retrieval techniques depending on the available data, that is if lidar, radar or both instruments detect cloud. This Combined Remote Sensor Retrieval Algorithm (CombRet) produces vertical profiles of liquid or ice water content (LWC or IWC), droplet effective radius (re), ice crystal generalized effective size (Dge), cloud phase, and cloud boundaries. The algorithm was compared with 3 other independent algorithms to help estimate the uncertainty in the cloud properties, fluxes, and heating rates (Comstock et al. 2013). The dataset is provided at 2 min temporal and 90 m vertical resolution. The current dataset is applied to time periods when the MMCR (Millimeter Cloud Radar) version of the ARSCL (Active Remotely-Sensed Cloud Locations) Value Added Product (VAP) is available. The MERGESONDE VAP is utilized where temperature and humidity profiles are required. Future additions to this dataset will utilize the new KAZR instrument and its associated VAPs.

Comstock, Jennifer

186

Cloud Properties and Radiative Heating Rates for TWP  

SciTech Connect (OSTI)

A cloud properties and radiative heating rates dataset is presented where cloud properties retrieved using lidar and radar observations are input into a radiative transfer model to compute radiative fluxes and heating rates at three ARM sites located in the Tropical Western Pacific (TWP) region. The cloud properties retrieval is a conditional retrieval that applies various retrieval techniques depending on the available data, that is if lidar, radar or both instruments detect cloud. This Combined Remote Sensor Retrieval Algorithm (CombRet) produces vertical profiles of liquid or ice water content (LWC or IWC), droplet effective radius (re), ice crystal generalized effective size (Dge), cloud phase, and cloud boundaries. The algorithm was compared with 3 other independent algorithms to help estimate the uncertainty in the cloud properties, fluxes, and heating rates (Comstock et al. 2013). The dataset is provided at 2 min temporal and 90 m vertical resolution. The current dataset is applied to time periods when the MMCR (Millimeter Cloud Radar) version of the ARSCL (Active Remotely-Sensed Cloud Locations) Value Added Product (VAP) is available. The MERGESONDE VAP is utilized where temperature and humidity profiles are required. Future additions to this dataset will utilize the new KAZR instrument and its associated VAPs.

Comstock, Jennifer

2013-11-07T23:59:59.000Z

187

Heat transfer system  

DOE Patents [OSTI]

A heat transfer system for a nuclear reactor. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.

McGuire, Joseph C. (Richland, WA)

1982-01-01T23:59:59.000Z

188

Heat transfer system  

DOE Patents [OSTI]

A heat transfer system for a nuclear reactor is described. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.

Not Available

1980-03-07T23:59:59.000Z

189

Heat flux solarimeter  

SciTech Connect (OSTI)

The solarimeter presented in this work is easy to assemble. It is calibrated and its performance is validated by means of Hottel's method. Finally, the curves obtained with this solarimeter are compared to the ones obtained with a commercial solarimeter. This device is based on the evaluation of the heat flow in a metal rod. In consequence, measurements are not affected by ambient temperature variations. On the other hand, there is a linear relationship between the temperatures measured at the rod ends and the incident radiation, as can be concluded both from the theory of its operation and the calibration lines obtained. The results obtained from the global irradiance measurements in the area of Los Polvorines (Buenos Aires Province), together with a preliminary evaluation of the solarimeter's response time, are presented in this work. (author)

Sartarelli, A.; Vera, S.; Cyrulies, E. [Instituto de Desarrollo Humano, Univ. Nac. de Gral. Sarmiento (IDH, UNGS), Los Polvorines (Argentina); Echarri, R. [Instituto de Desarrollo Humano, Univ. Nac. de Gral. Sarmiento (IDH, UNGS), Los Polvorines (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Samson, I. [INTEC (Instituto Tecnologico Santo Domingo), Santo Domingo (Dominican Republic)

2010-12-15T23:59:59.000Z

190

Consolidated Electric Cooperative- Heat Pump and Water Heating Rebates  

Broader source: Energy.gov [DOE]

Consolidated Electric Cooperative provides rebates to residential customers who install electric water heaters, dual-fuel heating system or geothermal heat pumps. A dual-fuel heating systems...

191

Photovoltaic roof heat flux  

E-Print Network [OSTI]

designs (relatively) Photovoltaic Solar P a n e l AtmosphereCALIFORNIA, SAN DIEGO Photovoltaic Roof Heat Flux A ThesisABSTRACT OF T H E THESIS Photovoltaic Roof Heat Flux by

Samady, Mezhgan Frishta

2011-01-01T23:59:59.000Z

192

HEAT TRANSFER FLUIDS  

E-Print Network [OSTI]

The choice of heat transfer fluids has significant effects on the performance, cost, and reliability of solar thermal systems. In this chapter, we evaluate existing heat transfer fluids such as oils and molten salts based ...

Lenert, Andrej

2012-01-01T23:59:59.000Z

193

Can Bohmian trajectories account for quantum recurrences having classical periodicities?  

E-Print Network [OSTI]

Quantum systems in specific regimes display recurrences at the period of the periodic orbits of the corresponding classical system. We investigate the excited hydrogen atom in a magnetic field -- a prototypical system of 'quantum chaos' -- from the point of view of the de Broglie Bohm (BB) interpretation of quantum mechanics. The trajectories predicted by BB theory are computed and contrasted with the time evolution of the wavefunction, which shows pronounced features at times matching the period of closed orbits of the classical hydrogen in a magnetic field problem. Individual BB trajectories do not possess these periodicities and cannot account for the quantum recurrences. These recurrences can however be explained by BB theory by considering the ensemble of trajectories compatible with an initial statistical distribution, although none of the trajectories of the ensemble are periodic, rendering unclear the dynamical origin of the classical periodicities.

A. Matzkin

2006-07-14T23:59:59.000Z

194

Abrasion resistant heat pipe  

DOE Patents [OSTI]

A specially constructed heat pipe for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.

Ernst, Donald M. (Leola, PA)

1984-10-23T23:59:59.000Z

195

MA HEAT Loan Overview  

Broader source: Energy.gov [DOE]

Presents information on the success of Massachusetts's HEAT loan offerings and how the financing tool is funded.

196

Abrasion resistant heat pipe  

DOE Patents [OSTI]

A specially constructed heat pipe is described for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.

Ernst, D.M.

1984-10-23T23:59:59.000Z

197

Solar heat receiver  

DOE Patents [OSTI]

A receiver is described for converting solar energy to heat a gas to temperatures from 700 to 900/sup 0/C. The receiver is formed to minimize impingement of radiation on the walls and to provide maximum heating at and near the entry of the gas exit. Also, the receiver is formed to provide controlled movement of the gas to be heated to minimize wall temperatures. The receiver is designed for use with gas containing fine heat absorbing particles, such as carbon particles.

Hunt, A.J.; Hansen, L.J.; Evans, D.B.

1982-09-29T23:59:59.000Z

198

Ammoniated salt heat pump  

SciTech Connect (OSTI)

A thermochemical heat pump/energy storage system using liquid ammoniate salts is described. The system, which can be used for space heating or cooling, provides energy storage for both functions. The bulk of the energy is stored as chemical energy and thus can be stored indefinitely. The system is well suited to use with a solar energy source or industrial waste heat.

Haas, W.R.; Jaeger, F.J.; Giordano, T.J.

1981-01-01T23:59:59.000Z

199

Heat Transfer Guest Editorial  

E-Print Network [OSTI]

Journal of Heat Transfer Guest Editorial We are indeed delighted in bringing out this special issue was showcased in diverse areas such as traditional heat and mass transfer, lab-on-chip, sensors, biomedical applica- tions, micromixers, fuel cells, and microdevices. Selected papers in the field of heat transfer

Kandlikar, Satish

200

Acoustic Heating Peter Ulmschneider  

E-Print Network [OSTI]

mechanisms. 1. The acoustic heating theory Only a few years after Edlen's (1941) discovery that the solar acoustic wave radiation- · b. field acoustic wave Figure 1. Panel a: Acoustic heating in late-type stars: effective temperature TeJ f, gravity g and mixing length parameter fr. Panel b: Acoustic heating in early

Ulmschneider, Peter

Note: This page contains sample records for the topic "time period heating" 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

Liquid heat capacity lasers  

DOE Patents [OSTI]

The heat capacity laser concept is extended to systems in which the heat capacity lasing media is a liquid. The laser active liquid is circulated from a reservoir (where the bulk of the media and hence waste heat resides) through a channel so configured for both optical pumping of the media for gain and for light amplification from the resulting gain.

Comaskey, Brian J. (Walnut Creek, CA); Scheibner, Karl F. (Tracy, CA); Ault, Earl R. (Livermore, CA)

2007-05-01T23:59:59.000Z

202

Pioneering Heat Pump Project  

Broader source: Energy.gov [DOE]

Project objectives: To install and monitor an innovative WaterFurnace geothermal system that is technologically advanced and evolving; To generate hot water heating from a heat pump that uses non-ozone depleting refrigerant CO2. To demonstrate the energy efficiency of this system ground source heat pump system.

203

Method and apparatus for determining vertical heat flux of geothermal field  

DOE Patents [OSTI]

A method and apparatus for determining vertical heat flux of a geothermal field, and mapping the entire field, is based upon an elongated heat-flux transducer (10) comprised of a length of tubing (12) of relatively low thermal conductivity with a thermopile (20) inside for measuring the thermal gradient between the ends of the transducer after it has been positioned in a borehole for a period sufficient for the tube to reach thermal equilibrium. The transducer is thermally coupled to the surrounding earth by a fluid annulus, preferably water or mud. A second transducer comprised of a length of tubing of relatively high thermal conductivity is used for a second thermal gradient measurement. The ratio of the first measurement to the second is then used to determine the earth's thermal conductivity, k.sub..infin., from a precalculated graph, and using the value of thermal conductivity thus determined, then determining the vertical earth temperature gradient, b, from predetermined steady state heat balance equations which relate the undisturbed vertical earth temperature distributions at some distance from the borehole and earth thermal conductivity to the temperature gradients in the transducers and their thermal conductivity. The product of the earth's thermal conductivity, k.sub..infin., and the earth's undisturbed vertical temperature gradient, b, then determines the earth's vertical heat flux. The process can be repeated many times for boreholes of a geothermal field to map vertical heat flux.

Poppendiek, Heinz F. (LaJolla, CA)

1982-01-01T23:59:59.000Z

204

A Feasibility Study: Mining Daily Traces for Home Heating Control  

E-Print Network [OSTI]

A Feasibility Study: Mining Daily Traces for Home Heating Control Dezhi Hong and Kamin Whitehouse savings as well as 14.9%­59.2% reduction in miss time. Keywords Energy, home heating, daily traces, prediction 1. INTRODUCTION Heating, ventilation and cooling (HVAC) contributes most to a home's energy bills

Whitehouse, Kamin

205

Original article Influence of heating conditions in continuous-flow  

E-Print Network [OSTI]

, holding and cooling phases. When milk was heated in a continuous microwave heating system, at 90 °C and cooling times. vitamin B1 / vitamin B2 / milk / microwave heating Résumé -- Étude de l'effet des exchange systems on the vitamin B1 and B2 content of milk Isabel SIERRA, Concepción VIDAL

Paris-Sud XI, Université de

206

Observing ocean heat content using satellite gravity and altimetry  

E-Print Network [OSTI]

: ocean heat content, altimetry, satellite gravity, steric height, remote sensing Citation: Jayne, S. RObserving ocean heat content using satellite gravity and altimetry Steven R. Jayne1,2 and John M with satellite measurements of the Earth's time-varying gravity to give improved estimates of the ocean's heat

Jayne, Steven

207

A corrosive resistant heat exchanger  

DOE Patents [OSTI]

A corrosive and erosive resistant heat exchanger which recovers heat from a contaminated heat stream. The heat exchanger utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat exchanger surface from the hot contaminated gas. The innocuous gas is pumped through ducts or perforations in the heat exchanger wall. Heat from the heat stream is transferred by radiation to the heat exchanger wall. Heat is removed from the outer heat exchanger wall by a heat recovery medium. 3 figs., 3 tabs.

Richlen, S.L.

1987-08-10T23:59:59.000Z

208

Absorption heat pump system  

DOE Patents [OSTI]

An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

Grossman, Gershon (Oak Ridge, TN); Perez-Blanco, Horacio (Knoxville, TN)

1984-01-01T23:59:59.000Z

209

Heat pump apparatus  

DOE Patents [OSTI]

A heat pump apparatus including a compact arrangement of individual tubular reactors containing hydride-dehydride beds in opposite end sections, each pair of beds in each reactor being operable by sequential and coordinated treatment with a plurality of heat transfer fluids in a plurality of processing stages, and first and second valves located adjacent the reactor end sections with rotatable members having multiple ports and associated portions for separating the hydride beds at each of the end sections into groups and for simultaneously directing a plurality of heat transfer fluids to the different groups. As heat is being generated by a group of beds, others are being regenerated so that heat is continuously available for space heating. As each of the processing stages is completed for a hydride bed or group of beds, each valve member is rotated causing the heat transfer fluid for the heat processing stage to be directed to that bed or group of beds. Each of the end sections are arranged to form a closed perimeter and the valve member may be rotated repeatedly about the perimeter to provide a continuous operation. Both valves are driven by a common motor to provide a coordinated treatment of beds in the same reactors. The heat pump apparatus is particularly suitable for the utilization of thermal energy supplied by solar collectors and concentrators but may be used with any source of heat, including a source of low-grade heat.

Nelson, Paul A. (Wheaton, IL); Horowitz, Jeffrey S. (Woodridge, IL)

1983-01-01T23:59:59.000Z

210

Spectrally enhancing near-field radiative heat transfer by exciting magnetic polariton in SiC gratings  

E-Print Network [OSTI]

In the present work, we theoretically demonstrate, for the first time, that near field radiative transport between 1D periodic grating microstructures separated by subwavelength vacuum gaps can be significantly enhanced by exciting magnetic resonance or polariton. Fluctuational electrodynamics that incorporates scattering matrix theory with rigorous coupled wave analysis is employed to exactly calculate the near field radiative heat flux between two SiC gratings. Besides the well known coupled surface phonon polaritons (SPhP), an additional spectral radiative heat flux peak, which is due to magnetic polariton, is found within the phonon absorption band of SiC. The mechanisms, behaviors and interplays between magnetic polariton, coupled SPhP, single interface SPhP, and Wood's anomaly in the near field radiative transport are elucidated in detail. The findings will open up a new way to control near field radiative heat transfer by magnetic resonance with micro or nanostructured metamaterials.

Yang, Yue

2015-01-01T23:59:59.000Z

211

HEATING AND COOLING PROTOSTELLAR DISKS  

SciTech Connect (OSTI)

We examine heating and cooling in protostellar disks using three-dimensional radiation-MHD calculations of a patch of the Solar nebula at 1 AU, employing the shearing-box and flux-limited radiation diffusion approximations. The disk atmosphere is ionized by stellar X-rays, well coupled to magnetic fields, and sustains a turbulent accretion flow driven by magnetorotational instability, while the interior is resistive and magnetically dead. The turbulent layers are heated by absorbing the light from the central star and by dissipating the magnetic fields. They are optically thin to their own radiation and cool inefficiently. The optically thick interior in contrast is heated only weakly, by re-emission from the atmosphere. The interior is colder than a classical viscous model and isothermal. The magnetic fields support an extended atmosphere that absorbs the starlight 1.5 times higher than the hydrostatic viscous model. The disk thickness thus measures not the internal temperature, but the magnetic field strength. Fluctuations in the fields move the starlight-absorbing surface up and down. The height ranges between 13% and 24% of the radius over timescales of several orbits, with implications for infrared variability. The fields are buoyant, so the accretion heating occurs higher in the atmosphere than the stresses. The heating is localized around current sheets, caused by magnetorotational instability at lower elevations and by Parker instability at higher elevations. Gas in the sheets is heated above the stellar irradiation temperature, even though accretion is much less than irradiation power when volume averaged. The hot optically thin current sheets might be detectable through their line emission.

Hirose, S. [Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, 3173-25 Showamachi, Kanazawa-ku, Yokohama, Kanagawa 236-0001 (Japan); Turner, N. J., E-mail: shirose@jamstec.go.jp, E-mail: neal.turner@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

2011-05-10T23:59:59.000Z

212

Active microchannel heat exchanger  

DOE Patents [OSTI]

The present invention is an active microchannel heat exchanger with an active heat source and with microchannel architecture. The microchannel heat exchanger has (a) an exothermic reaction chamber; (b) an exhaust chamber; and (c) a heat exchanger chamber in thermal contact with the exhaust chamber, wherein (d) heat from the exothermic reaction chamber is convected by an exothermic reaction exhaust through the exhaust chamber and by conduction through a containment wall to the working fluid in the heat exchanger chamber thereby raising a temperature of the working fluid. The invention is particularly useful as a liquid fuel vaporizer and/or a steam generator for fuel cell power systems, and as a heat source for sustaining endothermic chemical reactions and initiating exothermic reactions.

Tonkovich, Anna Lee Y. (Pasco, WA) [Pasco, WA; Roberts, Gary L. (West Richland, WA) [West Richland, WA; Call, Charles J. (Pasco, WA) [Pasco, WA; Wegeng, Robert S. (Richland, WA) [Richland, WA; Wang, Yong (Richland, WA) [Richland, WA

2001-01-01T23:59:59.000Z

213

Heating induced structural and chemical behavior of KD{sub 2}PO{sub 4} in the 25 °C–215 °C temperature range  

SciTech Connect (OSTI)

We have used powder x-ray diffraction (XRD) to investigate the structural and chemical modifications undergone by KD{sub 2}PO{sub 4} (DKDP) upon heating from room temperature to 215 °C. Full-profile (Le Bail) analysis of our temperature-resolved data shows no evidence of polymorphic structural transitions or deuterium–hydrogen isotope exchange occurring below T{sub s} = 185 °C. The lattice parameters of DKDP vary smoothly upon heating to T{sub s} and are 0.2% to 0.6% greater than those of its isostructural hydrogenated counterpart KH{sub 2}PO{sub 4} (KDP). In addition, XRD isotherms collected at T{sub s} demonstrate the structural and chemical stability of the title compound at this temperature over a 10.5 h time period. Upon further heating, however, the tetragonal DKDP phase becomes unstable, as evidenced by its transition to a monoclinic DKDP modification and eventual chemical decomposition via dehydration. - Highlights: • Structural and chemical behavior of KD{sub 2}PO{sub 4} is investigated upon heating to 215 °C • No polymorphic transitions or deuterium-hydrogen isotope exchange below T{sub s} = 185 °C • KD{sub 2}PO{sub 4} is structurally and chemically stable at T{sub s} over a 10.5 h time period • KD{sub 2}PO{sub 4} chemically decomposes via dehydration upon heating above T{sub d} = 195 °C.

Botez, Cristian E., E-mail: cbotez@utep.edu; Morris, Joshua L.; Encerrado Manriquez, Andres J.; Anchondo, Adan

2013-09-15T23:59:59.000Z

214

Dynamic Scheduling of Skippable Periodic Tasks: Issues and Proposals  

E-Print Network [OSTI]

-Chetto and Audrey Marchand IRCCyN, University of Nantes, Nantes, FRANCE Email: {maryline.chetto, audrey.marchand Scheduling of Skippable Periodic Tasks in Weakly-Hard Real-Time Systems," by M. Silly-Chetto, and A. Marchand

Paris-Sud XI, Université de

215

activity rules periodic: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

WITH PERIODIC ACTIVE THERMAL IMAGING Physics Websites Summary: methods where the thermal evolution of a scene is recorded while some external time varying energyIMPACT OF A LOSSY...

216

PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP  

E-Print Network [OSTI]

PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP W. D. C. Richards and W. L. Auxer General Electric Company Space Division King of Prussia, Pa. ABSTRACT A heat activated heat pump (HAHP for space heating since it directly utilizes the engine waste heat in addition to the energy obtained

Oak Ridge National Laboratory

217

Waste Heat Doesn't Have to be a Waste of Money- The American & Efird Heat Recovery Project: A First for the Textile Industry  

E-Print Network [OSTI]

"WASTE HEAT DOESN'T HAVE TO BE A WASTE OF MONEY" THE AMERICAN & EFIRD HEAT RECOVERY PROJECT: A FIRST FOR THE TEXTILE INDUSTRY STEVE W. SMITH, P.E., Program Manager Electrotechnology Sales Duke Power Company Charlotte, NC In 1989 American... and finishing Finishing Plant was targeted as an ideal operations recover energy from their site for a process heat pump installation. wastewater discharges usjng shell and tube Over a three year period, 1987-1990, Duke heat exchangers and preheat incoming...

Smith, S. W.

218

Electron Cyclotron Heating in RFP plasmas  

SciTech Connect (OSTI)

Reversed field pinches (RFP) plasmas are typically overdense ({omega}{sub pe}>{omega}{sub ce}) and thus not suitable for conventional electron cyclotron (EC) heating and current drive. In recent high plasma current discharges (I{sub p}>1.5 MA), however, the RFX-mod device was operated in underdense conditions ({omega}{sub pe}<{omega}{sub ce}) for the first time in an RFP. Thus, it is now possible to envisage heating the RFP plasma core by conventional EC at the 2nd harmonic, in the ordinary or extraordinary mode. We present a preliminary study of EC-heating feasibility in RFX-mod with the use of beam-tracing and full-wave codes. Although not competitive - as a heating system - with multi-MW Ohmic heating in an RFP, EC might be useful for perturbative transport studies, even at moderate power (hundreds of kW), and, more generally, for applications requiring localized power deposition.

Bilato, R.; Poli, E. [MPI fuer Plasmaphysik-Euratom Association Boltzmannstr. 2, D-85748 Garching (Germany); Volpe, F. [Department of Engineering Physics, University of Wisconsin, Madison, WI (United States); Koehn, A. [Institut fuer Plasmaforschung, Universitaet Stuttgart-Stuttgart (Germany); Cavazzana, R.; Paccagnella, R. [Consorzio RFX-Associazione EURATOM-ENEA sulla fusione-Padova (Italy); Farina, D. [IFP-CNR, EURATOM-ENEA-CNR Association-Milano (Italy)

2009-11-26T23:59:59.000Z

219

Heating remote rooms in passive solar buildings  

SciTech Connect (OSTI)

Remote rooms can be effectively heated by convection through a connecting doorway. A simple steady-state equation is developed for design purposes. Validation of a dynamic model is achieved using data obtained over a 13-day period. Dynamic effects are investigated using a simulation analysis for three different cases of driving temperature; the effect is to reduce the temperature difference between the driving room and the remote room compared to the steady-state model. For large temperature swings in the driving room a strategy which uses the intervening door in a diode mode is effective. The importance of heat-storing mass in the remote room is investigated.

Balcomb, J.D.

1981-01-01T23:59:59.000Z

220

Summer HeatSummer Heat Heat stress solutions  

E-Print Network [OSTI]

occur (then drink a lightly salted beverage like a sports drink). The water's temperature should be cool How should gardeners avoid becoming a safety threat to themselves and others when it's hot? Start to the heat. Become a weather watcher. Set up a small weather station (with a high/low thermom eter, rain

Liskiewicz, Maciej

Note: This page contains sample records for the topic "time period heating" 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

Heat pump system  

DOE Patents [OSTI]

An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

Swenson, Paul F. (Shaker Heights, OH); Moore, Paul B. (Fedhaven, FL)

1983-01-01T23:59:59.000Z

222

Heat pump system  

DOE Patents [OSTI]

An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

Swenson, Paul F.; Moore, Paul B.

1983-06-21T23:59:59.000Z

223

Chaotic Transport in Planar Periodic Vortical Flows  

E-Print Network [OSTI]

We have studied a chaotic transport in a two-dimensional periodic vortical flow under a time-dependent perturbation with period T where the global diffusion occurs along the stochastic web. By using the Melnikov method we construct the separatrix map describing the approximate dynamics near the saddle separatrices. Focusing on the small T, the width of the stochastic layer is calculated analytically by using the residue criterion and the diffusion constant by using the random phase assumption and correlated random walks. The analytical results are in good agreements with the results of two different types of numerical simulations by integrations of the Hamilton's equation of motion and by iterations of the separatrix map, which establishes the validity of the use of the separatrix map.

Taehoon Ahn; Seunghwan Kim

1993-09-24T23:59:59.000Z

224

Dynamic Simulation and Analysis of Heating Energy Consumption in a Residential Building  

E-Print Network [OSTI]

In winter, much of the building energy is used for heating in the north region of China. In this study, the heating energy consumption of a residential building in Tianjin during a heating period was simulated by using the EnergyPlus energy...

Liu, J.; Yang, M.; Zhao, X.; Zhu, N.

2006-01-01T23:59:59.000Z

225

Heat Management Strategy Trade Study  

SciTech Connect (OSTI)

This Heat Management Trade Study was performed in 2008-2009 to expand on prior studies in continued efforts to analyze and evaluate options for cost-effectively managing SNF reprocessing wastes. The primary objective was to develop a simplified cost/benefit evaluation for spent nuclear fuel (SNF) reprocessing that combines the characteristics of the waste generated through reprocessing with the impacts of the waste on heating the repository. Under consideration were age of the SNF prior to reprocessing, plutonium and minor actinide (MA) separation from the spent fuel for recycle, fuel value of the recycled Pu and MA, age of the remaining spent fuel waste prior to emplacement in the repository, length of time that active ventilation is employed in the repository, and elemental concentration and heat limits for acceptable glass waste form durability. A secondary objective was to identify and qualitatively analyze remaining issues such as (a) impacts of aging SNF prior to reprocessing on the fuel value of the recovered fissile materials, and (b) impact of reprocessing on the dose risk as developed in the Yucca Mountain Total System Performance Assessment (TSPA). Results of this study can be used to evaluate different options for managing decay heat in waste streams from spent nuclear fuel.

Nick Soelberg; Steve Priebe; Dirk Gombert; Ted Bauer

2009-09-01T23:59:59.000Z

226

Policies supporting Heat Pump Technologies  

E-Print Network [OSTI]

Policies supporting Heat Pump Technologies in Canada IEA Heat Pump Workshop London, UK November 13 in the world, with an average of 16,995 kilowatt-hours per annum. #12;Canada's Context for Heat Pumps Impacts avenues: Ground source heat pumps for cold climates (heating and cooling) Reversible air source heat

Oak Ridge National Laboratory

227

Effect of Heat Exchanger Material and Fouling on Thermoelectric Exhaust Heat Recovery  

SciTech Connect (OSTI)

This study is conducted in an effort to better understand and improve the performance of thermoelectric heat recovery systems for automotive use. For this purpose an experimental investigation of thermoelectrics in contact with clean and fouled heat exchangers of different materials is performed. The thermoelectric devices are tested on a bench-scale thermoelectric heat recovery apparatus that simulates automotive exhaust. The thermoelectric apparatus consists of a series of thermoelectric generators contacting a hot-side and a cold-side heat exchanger. The thermoelectric devices are tested with two different hot-side heat exchanger materials, stainless steel and aluminum, and at a range of simulated exhaust gas flowrates (40 to 150 slpm), exhaust gas temperatures (240 C and 280 C), and coolant-side temperatures (40 C and 80 C). It is observed that for higher exhaust gas flowrates, thermoelectric power output increases while overall system efficiency decreases. Degradation of the effectiveness of the EGR-type heat exchangers over a period of driving is also simulated by exposing the heat exchangers to diesel engine exhaust under thermophoretic conditions to form a deposit layer. For the fouled EGR-type heat exchangers, power output and system efficiency is observed to be significantly lower for all conditions tested. The study found, however, that heat exchanger material is the dominant factor in the ability of the system to convert heat to electricity with thermoelectric generators. This finding is thought to be unique to the heat exchangers used for this study, and not a universal trend for all system configurations.

Love, Norman [University of Texas, El Paso; Szybist, James P [ORNL; Sluder, Scott [ORNL

2011-01-01T23:59:59.000Z

228

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

229

Water-heating dehumidifier  

DOE Patents [OSTI]

A water-heating dehumidifier includes a refrigerant loop including a compressor, at least one condenser, an expansion device and an evaporator including an evaporator fan. The condenser includes a water inlet and a water outlet for flowing water therethrough or proximate thereto, or is affixed to the tank or immersed into the tank to effect water heating without flowing water. The immersed condenser design includes a self-insulated capillary tube expansion device for simplicity and high efficiency. In a water heating mode air is drawn by the evaporator fan across the evaporator to produce cooled and dehumidified air and heat taken from the air is absorbed by the refrigerant at the evaporator and is pumped to the condenser, where water is heated. When the tank of water heater is full of hot water or a humidistat set point is reached, the water-heating dehumidifier can switch to run as a dehumidifier.

Tomlinson, John J. (Knoxville, TN)

2006-04-18T23:59:59.000Z

230

Experimental and theoretical investigations of microwave heating  

E-Print Network [OSTI]

the variation of the computed time response of the thermocouple with variation of the heat transfer coefficient. It can be seen that the response gets slower as the heat transfer coefficient is decreased and vice versa... and vice versa. Table 4.3 Variation of Time Constant with Diameter of Thermocouple Used Diameter (inch) Time constant(sec) 0.02 1.55 0.022 1.705 0.018 1.395 15 Variation of response with D 0 20 40 60 80 100 120 0 5 10 15 20 25...

Kota, Bhagat Chandra

2004-09-30T23:59:59.000Z

231

Comparative evaluation of the impacts of domestic gas and electric heat pump heating on air pollution in California. Final report  

SciTech Connect (OSTI)

Residential space and water heating accounts for approximately 12% of California`s and 15% of the United States, energy consumption. most Of the residential heating is by direct use of natural gas. combustion of natural gas is a contributor to the overall air pollution,, especially CO and NO{sub x} in the urban areas. Another efficient method for domestic water and space heating is use of electric heat pumps, the most popular category of which uses air as its heat source. Electric heat pumps do not emit air pollutants at the point of use, but use electric power, which is a major contributor to air pollution at its point of generation from fossil fuels. It is the specific objective of this report to evaluate and compare the energy efficiency and source air pollutants of natural gas heaters and electric heat pumps used for domestic heating. Effect of replacing natural gas heaters with electric heat pumps on air pollutant emissions due to domestic heating in two urban areas and in California as a whole has also been evaluated. The analysis shows that with the present state of technology, electric heat pumps have higher heating efficiencies than natural gas heaters. Considering the current electricity generation mix in the US, electric heat pumps produce two to four times more NO{sub x}, much less CO, and comparable amount of CO{sub 2} per unit of useful heating energy compared to natural gas heaters. With California mix, electric heat pumps produce comparable NO{sub x} and much less CO and approximately 30% less CO{sub 2} per unit heat output. Replacement of natural gas heaters with electric heat pumps will slightly increase the overall NO{sub x}, and reduce CO and CO{sub 2} emissions in California. The effect of advanced technology power generation and heat pump heating has also been analyzed.

Ganji, A. [San Francisco State Univ., CA (United States). Div. of Engineering

1992-07-01T23:59:59.000Z

232

Comparative evaluation of the impacts of domestic gas and electric heat pump heating on air pollution in California  

SciTech Connect (OSTI)

Residential space and water heating accounts for approximately 12% of California's and 15% of the United States, energy consumption. most Of the residential heating is by direct use of natural gas. combustion of natural gas is a contributor to the overall air pollution,, especially CO and NO{sub x} in the urban areas. Another efficient method for domestic water and space heating is use of electric heat pumps, the most popular category of which uses air as its heat source. Electric heat pumps do not emit air pollutants at the point of use, but use electric power, which is a major contributor to air pollution at its point of generation from fossil fuels. It is the specific objective of this report to evaluate and compare the energy efficiency and source air pollutants of natural gas heaters and electric heat pumps used for domestic heating. Effect of replacing natural gas heaters with electric heat pumps on air pollutant emissions due to domestic heating in two urban areas and in California as a whole has also been evaluated. The analysis shows that with the present state of technology, electric heat pumps have higher heating efficiencies than natural gas heaters. Considering the current electricity generation mix in the US, electric heat pumps produce two to four times more NO{sub x}, much less CO, and comparable amount of CO{sub 2} per unit of useful heating energy compared to natural gas heaters. With California mix, electric heat pumps produce comparable NO{sub x} and much less CO and approximately 30% less CO{sub 2} per unit heat output. Replacement of natural gas heaters with electric heat pumps will slightly increase the overall NO{sub x}, and reduce CO and CO{sub 2} emissions in California. The effect of advanced technology power generation and heat pump heating has also been analyzed.

Ganji, A. (San Francisco State Univ., CA (United States). Div. of Engineering)

1992-07-01T23:59:59.000Z

233

Tidal Heating of Extra-Solar Planets  

E-Print Network [OSTI]

Extra-solar planets close to their host stars have likely undergone significant tidal evolution since the time of their formation. Tides probably dominated their orbital evolution once the dust and gas had cleared away, and as the orbits evolved there was substantial tidal heating within the planets. The tidal heating history of each planet may have contributed significantly to the thermal budget that governed the planet's physical properties, including its radius, which in many cases may be measured by observing transit events. Typically, tidal heating increases as a planet moves inward toward its star and then decreases as its orbit circularizes. Here we compute the plausible heating histories for several planets with measured radii, using the same tidal parameters for the star and planet that had been shown to reconcile the eccentricity distribution of close-in planets with other extra-solar planets. Several planets are discussed, including for example HD 209458 b, which may have undergone substantial tidal heating during the past billion years, perhaps enough to explain its large measured radius. Our models also show that GJ 876 d may have experienced tremendous heating and is probably not a solid, rocky planet. Theoretical models should include the role of tidal heating, which is large, but time-varying.

Brian Jackson; Richard Greenberg; Rory Barnes

2008-02-29T23:59:59.000Z

234

Mechanical Compression Heat Pumps  

E-Print Network [OSTI]

MECHANICAL COMPRESSION HEAT PUMPS Thomas-L. Apaloo and K. Kawamura Mycom Corporation, Los Angeles, California J. Matsuda, Mayekawa Mfg. Co., Tokyo, Japan ABSTRACT Mechanical compression heat pumping is not new in industrial applications.... In fact, industry history suggests that the theoretical concept was developed before 1825. Heat pump manufacturers gained the support of consultants and end-users when the energy crisis hit this country in 1973. That interest, today, has been...

Apaloo, T. L.; Kawamura, K.; Matsuda, J.

235

Heat storage duration  

SciTech Connect (OSTI)

Both the amount and duration of heat storage in massive elements of a passive building are investigated. Data taken for one full winter in the Balcomb solar home are analyzed with the aid of sub-system simulation models. Heat storage duration is tallied into one-day intervals. Heat storage location is discussed and related to overall energy flows. The results are interpreted and conclusions drawn.

Balcomb, J.D.

1981-01-01T23:59:59.000Z

236

Periodic fluctuations in deep water formation due to sea ice  

E-Print Network [OSTI]

During the last ice age several quasi-periodic abrupt warming events took place. Known as Dansgaard-Oeschger (DO) events their effects were felt globally, although the North Atlantic experienced the largest temperature anomalies. Paleoclimate data shows that the fluctuations often occurred right after massive glacial meltwater releases in the North Atlantic and in bursts of three or four with progressively decreasing strengths. In this study a simple dynamical model of an overturning circulation and sea ice is developed with the goal of understanding the fundamental mechanisms that could have caused the DO events. Interaction between sea ice and the overturning circulation in the model produces self-sustained oscillations. Analysis and numerical experiments reveal that the insulating effect of sea ice causes the ocean to periodically vent out accumulated heat in the deep ocean into the atmosphere. Subjecting the model to idealized freshwater forcing mimicking Heinrich events causes modulation of the natural periodicity and produces burst patterns very similar to what is observed in temperature proxy data. Numerical experiments with the model also suggests that the characteristic period of 1,500 years is due to the geometry, or the effective heat capacity, of the ocean that comes under sea ice cover.

Raj Saha

2015-02-21T23:59:59.000Z

237

Solar Heating in Uppsala.  

E-Print Network [OSTI]

?? The housing corporation Uppsalahem has installed asolar heating system in the neighbourhood Haubitsen,which was renovated in 2011. This report examineshow much energy the solar… (more)

Blomqvist, Emelie; Häger, Klara

2012-01-01T23:59:59.000Z

238

Solar heating in Colombia.  

E-Print Network [OSTI]

?? This report describes the process of a thesis implemented in Colombia concerning solar energy. The project was to install a self-circulating solar heating system,… (more)

Skytt, Johanna

2012-01-01T23:59:59.000Z

239

Waste Heat Recovery  

Office of Environmental Management (EM)

DRAFT - PRE-DECISIONAL - DRAFT 1 Waste Heat Recovery 1 Technology Assessment 2 Contents 3 1. Introduction to the TechnologySystem ......

240

Heat and mass exchanger  

DOE Patents [OSTI]

A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.

Lowenstein, Andrew (Princeton, NJ); Sibilia, Marc J. (Princeton, NJ); Miller, Jeffrey A. (Hopewell, NJ); Tonon, Thomas (Princeton, NJ)

2007-09-18T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" 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

Heat and mass exchanger  

DOE Patents [OSTI]

A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.

Lowenstein, Andrew (Princeton, NJ); Sibilia, Marc J. (Princeton, NJ); Miller, Jeffrey A. (Hopewell, NJ); Tonon, Thomas (Princeton, NJ)

2011-06-28T23:59:59.000Z

242

HEATS: Thermal Energy Storage  

SciTech Connect (OSTI)

HEATS Project: The 15 projects that make up ARPA-E’s HEATS program, short for “High Energy Advanced Thermal Storage,” seek to develop revolutionary, cost-effective ways to store thermal energy. HEATS focuses on 3 specific areas: 1) developing high-temperature solar thermal energy storage capable of cost-effectively delivering electricity around the clock and thermal energy storage for nuclear power plants capable of cost-effectively meeting peak demand, 2) creating synthetic fuel efficiently from sunlight by converting sunlight into heat, and 3) using thermal energy storage to improve the driving range of electric vehicles (EVs) and also enable thermal management of internal combustion engine vehicles.

None

2012-01-01T23:59:59.000Z

243

Heat rejection system  

DOE Patents [OSTI]

A cooling system for rejecting waste heat consists of a cooling tower incorporating a plurality of coolant tubes provided with cooling fins and each having a plurality of cooling channels therein, means for directing a heat exchange fluid from the power plant through less than the total number of cooling channels to cool the heat exchange fluid under normal ambient temperature conditions, means for directing water through the remaining cooling channels whenever the ambient temperature rises above the temperature at which dry cooling of the heat exchange fluid is sufficient and means for cooling the water.

Smith, Gregory C. (Richland, WA); Tokarz, Richard D. (Richland, WA); Parry, Jr., Harvey L. (Richland, WA); Braun, Daniel J. (Richland, WA)

1980-01-01T23:59:59.000Z

244

Passive solar space heating  

SciTech Connect (OSTI)

An overview of passive solar space heating is presented indicating trends in design, new developments, performance measures, analytical design aids, and monitored building results.

Balcomb, J.D.

1980-01-01T23:59:59.000Z

245

Multiple pollutant removal using the condensing heat exchanger: Phase 1 final report, November 1995--June 1997. Addendum 2: Task 3 topical report -- Long term wear test  

SciTech Connect (OSTI)

Long-term operation of a condensing heat exchanger under typical coal-fired flue gas conditions was investigated in Phase 1, Task 3 of the Multiple Pollutant Removal Using the Condensing Heat Exchanger test program. The specific goal of this task was to determine the amount of wear, if any, on the Teflon{reg_sign}-covered heat transfer tubes in a condensing heat exchanger. A pilot-scale single-stage condensing heat exchanger (CHX{reg_sign}) was operated under typical coal-fired flue gas conditions on a continuous basis for a period of approximately 10 months. Operating conditions and particulate loadings for the test unit were monitored, Teflon{reg_sign} film thickness measurements were conducted, and surface replications (which duplicate the surface finish at the microscopic level) were taken at various times during the test. Data from the test indicate that virtually no decrease in Teflon{reg_sign} thickness was observed for the coating on the first two rows of heat exchanger tubes, even at high inlet particulate loadings (400 mg/dscm [0.35 lb/10{sup 6} Btu]). Evidence of wear was present only at the microscopic level, and even then was very minor in severity. Operation at high inlet particulate loadings resulted in accumulated ash deposits within the heat exchanger. Installation of a modified (higher flow rate) wash nozzle manifold substantially reduced subsequent deposit formation.

Kudlac, G.A.

1998-06-01T23:59:59.000Z

246

Static Heat Loads in the LHC Arc Cryostats: Final Assessment  

E-Print Network [OSTI]

This note presents the final assessment of the static heat loads in the LHC arc cryostats, using different experimental methods during the first commissioning period in 2007. This assessment further develops and completes previous estimates made during the commissioning of sector 7_8 [1]. The estimate of the helium inventory, a prerequisite for the heat load calculation, is also presented. Heat loads to the cold mass are evaluated from the internal energy balance during natural as well as powered warm-ups of the helium baths in different subsector. The helium inventory is calculated from the internal energy balance during powered warm-ups and matched with previous assessments. Furthermore, heat loads to the thermal shield are estimated from the non-isothermal cooling of the supercritical helium in line E. The comparison of measured heat loads with previous estimates and with budgeted values is then presented, while their correlation with some important parameters like insulation vacuum pressure and some heat ...

Parma, V

2010-01-01T23:59:59.000Z

247

Use of impure inert gases in the controlled heating and cooling of mixed conducting metal oxide materials  

DOE Patents [OSTI]

Method for processing an article comprising mixed conducting metal oxide material. The method comprises contacting the article with an oxygen-containing gas and either reducing the temperature of the oxygen-containing gas during a cooling period or increasing the temperature of the oxygen-containing gas during a heating period; during the cooling period, reducing the oxygen activity in the oxygen-containing gas during at least a portion of the cooling period and increasing the rate at which the temperature of the oxygen-containing gas is reduced during at least a portion of the cooling period; and during the heating period, increasing the oxygen activity in the oxygen-containing gas during at least a portion of the heating period and decreasing the rate at which the temperature of the oxygen-containing gas is increased during at least a portion of the heating period.

Carolan, Michael Francis (Allentown, PA); Bernhart, John Charles (Fleetwood, PA)

2012-08-21T23:59:59.000Z

248

Heat pipes and use of heat pipes in furnace exhaust  

DOE Patents [OSTI]

An array of a plurality of heat pipe are mounted in spaced relationship to one another with the hot end of the heat pipes in a heated environment, e.g. the exhaust flue of a furnace, and the cold end outside the furnace. Heat conversion equipment is connected to the cold end of the heat pipes.

Polcyn, Adam D. (Pittsburgh, PA)

2010-12-28T23:59:59.000Z

249

Proceedings of Heat Transfer 2003: ASME Summer Heat Transfer Conference  

E-Print Network [OSTI]

Proceedings of Heat Transfer 2003: ASME Summer Heat Transfer Conference Las Vegas, Nevada, USA July 21-23, 2003 HT2003-47449 HEAT TRANSFER FROM A MOVING AND EVAPORATING MENISCUS ON A HEATED SURFACE meniscus with complete evaporation of water without any meniscus break-up. The experimental heat transfer

Kandlikar, Satish

250

IMPLEMENTING GROUND SOURCE HEAT PUMP AND GROUND LOOP HEAT EXCHANGER  

E-Print Network [OSTI]

IMPLEMENTING GROUND SOURCE HEAT PUMP AND GROUND LOOP HEAT EXCHANGER MODELS IN THE ENERGYPLUS #12;ii IMPLEMENTING GROUND SOURCE HEAT PUMP AND GROUND LOOP HEAT EXCHANGER MODELS IN THE ENERGYPLUS............................................................... 2 1.3. Overview of the Parameter Estimation Water-to-Water Heat Pump Model ........... 5 1

251

First university owned district heating system using biomass heat  

E-Print Network [OSTI]

Highlights · First university owned district heating system using biomass heat · Capacity: 15 MMBtu Main Campus District Heating Performance · Avoided: 3500 tonnes of CO2 · Particulate: less than 10 mg District Heating Goals To displace 85% of natural gas used for core campus heating. Fuel Bunker Sawmill

Northern British Columbia, University of

252

Microchannel heat sink assembly  

DOE Patents [OSTI]

The present invention provides a microchannel heat sink with a thermal range from cryogenic temperatures to several hundred degrees centigrade. The heat sink can be used with a variety of fluids, such as cryogenic or corrosive fluids, and can be operated at a high pressure. The heat sink comprises a microchannel layer preferably formed of silicon, and a manifold layer preferably formed of glass. The manifold layer comprises an inlet groove and outlet groove which define an inlet manifold and an outlet manifold. The inlet manifold delivers coolant to the inlet section of the microchannels, and the outlet manifold receives coolant from the outlet section of the microchannels. In one embodiment, the manifold layer comprises an inlet hole extending through the manifold layer to the inlet manifold, and an outlet hole extending through the manifold layer to the outlet manifold. Coolant is supplied to the heat sink through a conduit assembly connected to the heat sink. A resilient seal, such as a gasket or an O-ring, is disposed between the conduit and the hole in the heat sink in order to provide a watertight seal. In other embodiments, the conduit assembly may comprise a metal tube which is connected to the heat sink by a soft solder. In still other embodiments, the heat sink may comprise inlet and outlet nipples. The present invention has application in supercomputers, integrated circuits and other electronic devices, and is suitable for cooling materials to superconducting temperatures. 13 figs.

Bonde, W.L.; Contolini, R.J.

1992-03-24T23:59:59.000Z

253

Geothermal direct-heat utilization assistance. Quarterly project progress report, July 1994--September 1994  

SciTech Connect (OSTI)

This paper is a third quarter 1994 report of activities of the Geo-Heat Center of Oregon Institute of Technology. It describes contacts with parties during this period related to assistance with geothermal direct heat applications. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, resources, and equipment. Research is also being conducted on failures of vertical lineshaft turbines in geothermal wells.

Not Available

1994-10-01T23:59:59.000Z

254

Solar heating system  

DOE Patents [OSTI]

An improved solar heating system in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75.degree. to 180.degree. F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing and releasing heat for distribution.

Schreyer, James M. (Oak Ridge, TN); Dorsey, George F. (Concord, TN)

1982-01-01T23:59:59.000Z

255

Improved solar heating systems  

DOE Patents [OSTI]

An improved solar heating system is described in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75 to 180/sup 0/F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing ad releasing heat for distribution.

Schreyer, J.M.; Dorsey, G.F.

1980-05-16T23:59:59.000Z

256

Down hole periodic seismic generator  

DOE Patents [OSTI]

A down hole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.

Hardee, Harry C. (Albuquerque, NM); Hills, Richard G. (Las Cruces, NM); Striker, Richard P. (Albuquerque, NM)

1989-01-01T23:59:59.000Z

257

Advanced downhole periodic seismic generator  

DOE Patents [OSTI]

An advanced downhole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.

Hardee, Harry C. (Albuquerque, NM); Hills, Richard G. (Las Cruces, NM); Striker, Richard P. (Albuquerque, NM)

1991-07-16T23:59:59.000Z

258

Heat Pipe Technology for Energy Conservation in the Process Industry  

E-Print Network [OSTI]

and installation eXBenses. Summary The use of heat pipes in recovering t ermal energy has been shown to offer many advant ges over alternative typP. systems. Probably tje most attractive feature of any heat pipe heat e changer is its adaptability to a wine...HEAT PIPE TECHNOLOGY FOR ENERGY CONSERVATION IN THE PROCESS INDUSTRY Berwin L. Price. Jr. Q-dot Corporation Garland. Texas ABSTRACT Many applications for heat pipe technology have emerged in the relatively short time this technology has been...

Price, B. L. Jr.

259

Thermo-mechanical simulations in double-sided heat transfer power assemblies.  

E-Print Network [OSTI]

Thermo-mechanical simulations in double-sided heat transfer power assemblies. E. Woirgard; I. Favre In power assemblies, heat transfer due to the die self- heating is one of the most important point on time life assemblies. Heat has to be evacuated toward the base- plate not to weaken the solder joint under

Boyer, Edmond

260

Predicting household occupancy for smart heating control: A comparative performance analysis of  

E-Print Network [OSTI]

, energy management, smart home, energy efficiency, thermostat strategy, heating setback Corresponding, a heating control system may require some time to heat a home to a comfortable temperature after itsPredicting household occupancy for smart heating control: A comparative performance analysis

Note: This page contains sample records for the topic "time period heating" 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

Geothermal direct-heat utilization assistance: Quarterly project progress report, January--March 1995  

SciTech Connect (OSTI)

The report summarizes geothermal activities of the Geo-Heat Center at Oregon Institute of Technology for the second quarter of FY-95. It describes 92 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, resources and equipment. Research activities are summarized on geothermal energy cost evaluation, low temperature resource assessment and ground-source heat pump case studies and utility programs. Outreach activities include the publication of a geothermal direct heat Bulletin, dissemination of information, geothermal library, and progress monitor reports on geothermal resources and utilization.

NONE

1995-05-01T23:59:59.000Z

262

RADIATIVE HEATING OF THE SOLAR CORONA  

SciTech Connect (OSTI)

We investigate the effect of solar visible and infrared radiation on electrons in the Sun's atmosphere using a Monte Carlo simulation of the wave-particle interaction and conclude that sunlight provides at least 40% and possibly all of the power required to heat the corona, with the exception of dense magnetic flux loops. The simulation uses a radiation waveform comprising 100 frequency components spanning the solar blackbody spectrum. Coronal electrons are heated in a stochastic manner by low coherence solar electromagnetic radiation. The wave 'coherence time' and 'coherence volume' for each component is determined from optical theory. The low coherence of solar radiation allows moving electrons to gain energy from the chaotic wave field which imparts multiple random velocity 'kicks' to these particles causing their velocity distribution to broaden or heat. Monte Carlo simulations of broadband solar radiative heating on ensembles of 1000 electrons show heating at per particle levels of 4.0 x 10{sup -21} to 4.0 x 10{sup -20} W, as compared with non-loop radiative loss rates of {approx}1 x 10{sup -20} W per electron. Since radiative losses comprise nearly all of the power losses in the corona, sunlight alone can explain the elevated temperatures in this region. The volume electron heating rate is proportional to density, and protons are assumed to be heated either by plasma waves or through collisions with electrons.

Moran, Thomas G., E-mail: moran@grace.nascom.nasa.gov [Physics Department, Catholic University of America, 200 Hannan Hall, Washington, DC 20064 (United States) and NASA/GSFC, Code 671, Greenbelt, MD 20771 (United States)

2011-10-20T23:59:59.000Z

263

Heat-Of-Reaction Chemical Heat Pumps--Possible Configurations  

E-Print Network [OSTI]

-807. (5) K. Kesavan. The Use of Dissociating Gases As the Working Fluid in Thermodynamic Power Conversion Cycles, Ph.D. thesis. Carnegie-Mellon University, 1978, Ann Arbor, MI: University Microfilms International, 1978. 5. Heat amplifier with a gas...ABSTRACT Chemical heat pumps utilize working fluids which undergo reversible chemical changes. Mechanically driven reactive heat pump cycles or, alternatively, hl~a: driven heat pumps in which either heat engine or heat pump working fluid...

Kirol, L. D.

264

Proceedings: Heat exchanger workshop  

SciTech Connect (OSTI)

Heat transfer processes are of controlling importance in the operation of a thermal power plant. Heat exchangers are major cost items and are an important source of problems causing poor power plant availability and performance. A workshop to examine the improvements that can be made to heat exchangers was sponsored by the Electric Power Research Institute (EPRI) on June 10-11, 1986, in Palo Alto, California. This workshop was attended by 25 engineers and scientists representing EPRI-member utilities and EPRI consultants. A forum was provided for discussions related to the design, operation and maintenance of utility heat transfer equipment. The specific objectives were to identify research directions that could significantly improve heat exchanger performance, reliability and life cycle economics. Since there is a great diversity of utility heat transfer equipment in use, this workshop addressed two equipment categories: Boiler Feedwater Heaters (FWH) and Heat Recovery Steam Generators (HRSG). The workshop was divided into the following panel sessions: functional design, mechanical design, operation, suggested research topics, and prioritization. Each panel session began with short presentations by experts on the subject and followed by discussions by the attendees. This report documents the proceedings of the workshop and contains recommendations of potentially valuable areas of research and development. 4 figs.

Not Available

1987-07-01T23:59:59.000Z

265

Micro heat barrier  

DOE Patents [OSTI]

A highly effective, micron-scale micro heat barrier structure and process for manufacturing a micro heat barrier based on semiconductor and/or MEMS fabrication techniques. The micro heat barrier has an array of non-metallic, freestanding microsupports with a height less than 100 microns, attached to a substrate. An infrared reflective membrane (e.g., 1 micron gold) can be supported by the array of microsupports to provide radiation shielding. The micro heat barrier can be evacuated to eliminate gas phase heat conduction and convection. Semi-isotropic, reactive ion plasma etching can be used to create a microspike having a cusp-like shape with a sharp, pointed tip (<0.1 micron), to minimize the tip's contact area. A heat source can be placed directly on the microspikes. The micro heat barrier can have an apparent thermal conductivity in the range of 10.sup.-6 to 10.sup.-7 W/m-K. Multiple layers of reflective membranes can be used to increase thermal resistance.

Marshall, Albert C.; Kravitz, Stanley H.; Tigges, Chris P.; Vawter, Gregory A.

2003-08-12T23:59:59.000Z

266

City of Klamath Falls District Heating District Heating Low Temperatur...  

Open Energy Info (EERE)

Geothermal Facility Jump to: navigation, search Name City of Klamath Falls District Heating District Heating Low Temperature Geothermal Facility Facility City of Klamath...

267

Cooling and Clusters: When Is Heating Needed?  

E-Print Network [OSTI]

There are (at least) two unsolved problems concerning the current state of the thermal gas in clusters of galaxies. The first is identifying the source of the heating which offsets cooling in the centers of clusters with short cooling times (the ``cooling flow'' problem). The second is understanding the mechanism which boosts the entropy in cluster and group gas. Since both of these problems involve an unknown source of heating it is tempting to identify them with the same process, particular since AGN heating is observed to be operating at some level in a sample of well-observed ``cooling flow'' clusters. Here we show, using numerical simulations of cluster formation, that much of the gas ending up in clusters cools at high redshift and so the heating is also needed at high-redshift, well before the cluster forms. This indicates that the same process operating to solve the cooling flow problem may not also resolve the cluster entropy problem.

Greg L. Bryan; G. Mark Voit

2005-02-22T23:59:59.000Z

268

Economic Options for Upgrading Waste Heat  

E-Print Network [OSTI]

There are at least six major types of equipment that upgrade waste heat: (1) thermocompressor; (2) electric drive compressor heat pump; (3) absorption heat pump; (4) high temperature heat powered compressor heat pump; (5) reverse absorption heat...

Erickson, D. C.

1983-01-01T23:59:59.000Z

269

Heat treatment furnace  

DOE Patents [OSTI]

A furnace heats through both infrared radiation and convective air utilizing an infrared/purge gas design that enables improved temperature control to enable more uniform treatment of workpieces. The furnace utilizes lamps, the electrical end connections of which are located in an enclosure outside the furnace chamber, with the lamps extending into the furnace chamber through openings in the wall of the chamber. The enclosure is purged with gas, which gas flows from the enclosure into the furnace chamber via the openings in the wall of the chamber so that the gas flows above and around the lamps and is heated to form a convective mechanism in heating parts.

Seals, Roland D; Parrott, Jeffrey G; DeMint, Paul D; Finney, Kevin R; Blue, Charles T

2014-10-21T23:59:59.000Z

270

Heat pumps and under floor heating as a heating system for Finnish low-rise residential buildings.  

E-Print Network [OSTI]

??In bachelor’s thesis the study of under floor heating system with ground source heat pump for the heat transfers fluid heating is considered. The case… (more)

Chuduk, Svetlana

2010-01-01T23:59:59.000Z

271

Promotion of efficient heat pumps for heating (ProHeatPump)  

E-Print Network [OSTI]

Project Promotion of efficient heat pumps for heating (ProHeatPump) EIE/06/072 / S12.444283 Supplementary report: Heat pumps in Norway May 2009 Work Package 4: Policy context and measures Authors: Nils of the industry and markets in the ProHeatPump partner countries, and should provide useful comparisons

272

An Autonomous Adaptive Scheduling Agent for Period Searching  

E-Print Network [OSTI]

We describe the design and implementation of an autonomous adaptive software agent that addresses the practical problem of observing undersampled, periodic, time-varying phenomena using a network of HTN-compliant robotic telescopes. The algorithm governing the behaviour of the agent uses an optimal geometric sampling technique to cover the period range of interest, but additionally implements proactive behaviour that maximises the optimality of the dataset in the face of an uncertain and changing operating environment.

Eric S. Saunders; Tim Naylor; Alasdair Allan

2008-01-24T23:59:59.000Z

273

Intergalactic dust and its photoelectric heating  

E-Print Network [OSTI]

We have examined the dust photoelectric heating in the intergalactic medium (IGM). The heating rate in a typical radiation field of the IGM is represented by $\\Gamma_{\\rm pe} = 1.2\\times10^{-34}$ erg s$^{-1}$ cm$^{-3}$ $({\\cal D}/10^{-4})(n_{\\rm H}/10^{-5} {\\rm cm^{-3}})^{4/3} (J_{\\rm L}/10^{-21} {\\rm erg s^{-1} cm^{-2} Hz^{-1} sr^{-1}})^{2/3} (T/10^4 {\\rm K})^{-1/6}$, where ${\\cal D}$ is the dust-to-gas mass ratio, $n_{\\rm H}$ is the hydrogen number density, $J_{\\rm L}$ is the mean intensity at the hydrogen Lyman limit of the background radiation, and $T$ is the gas temperature, if we assume the new X-ray photoelectric yield model by Weingartner et al. (2006) and the dust size distribution in the Milky Way by Mathis, Rumpl, & Nordsieck (1977). This heating rate dominates the HI and HeII photoionization heating rates when the hydrogen number density is less than $\\sim10^{-6}$ cm$^{-3}$ if ${\\cal D}=10^{-4}$ which is 1% of that in the Milky Way, although the heating rate is a factor of 2--4 smaller than that with the old yield model by Weingartner & Draine (2001). The grain size distribution is very important. If only large ($\\ge0.1$ $\\mu$m) grains exist in the IGM, the heating rate is reduced by a factor of $\\simeq5$. Since the dust heating is more efficient in a lower density medium relative to the photoionization heating, it may cause an inverted temperature--density relation in the low density IGM suggested by Bolton et al. (2008). Finally, we have found that the dust heating is not very important in the mean IGM before the cosmic reionization.

Akio K. Inoue; Hideyuki Kamaya

2008-10-31T23:59:59.000Z

274

Composite heat damage assessment  

SciTech Connect (OSTI)

The effects of heat damage were determined on the residual mechanical, physical, and chemical properties of IM6/3501-6 laminates, and potential nondestructive techniques to detect and assess material heat damage were evaluated. About one thousand preconditioned specimens were exposed to elevated temperatures, then cooled to room temperature and tested in compression, flexure, interlaminar shear, shore-D hardness, weight loss, and change in thickness. Specimens experienced significant and irreversible reduction in their residual properties when exposed to temperatures exceeding the material upper service temperature of this material (350{degrees}F). The Diffuse Reflectance Infrared Fourier Transform and Laser-Pumped Fluorescence techniques were found to be capable of rapid, in-service, nondestructive detection and quantitation of heat damage in IM6/3501- 6. These techniques also have the potential applicability to detect and assess heat damage effects in other polymer matrix composites.

Janke, C.J.; Wachter, E.A. [Oak Ridge National Lab., TN (United States); Philpot, H.E. [Oak Ridge K-25 Site, TN (United States); Powell, G.L. [Oak Ridge Y-12 Plant, TN (United States)

1993-12-31T23:59:59.000Z

275

Solar Heating Contractor Licensing  

Broader source: Energy.gov [DOE]

Michigan offers a solar heating contractor specialty license to individuals who have at least three years of experience installing solar equipment under the direction of a licensed solar contractor...

276

Passive solar heating analysis  

SciTech Connect (OSTI)

This book discusses about the design of solar heating systems. The terms and symbols are clearly defined. Step-by-step procedures are indicated. Worked examples are given with tables, graphs, appendixes.

Balcomb, J.D.; Jones, R.W.; Mc Farland, R.D.; Wray, W.O.

1984-01-01T23:59:59.000Z

277

Wood Heating Fuel Exemption  

Broader source: Energy.gov [DOE]

This statute exempts from the state sales tax all wood or "refuse-derived" fuel used for heating purposes. The law does not make any distinctions about whether the qualified fuels are used for...

278

Heat Waves, Global Warming, and Mitigation  

E-Print Network [OSTI]

Heat Waves, Global Warming, and Mitigation Ann E. Carlson*II. HEAT WAVE DEFINITIONS .. A . HCHANGE AND HEAT WAVES .. CLIMATE III. IV. HEAT

Carlson, Ann E.

2008-01-01T23:59:59.000Z

279

Heat flux limiting sleeves  

DOE Patents [OSTI]

A heat limiting tubular sleeve extending over only a portion of a tube having a generally uniform outside diameter, the sleeve being open on both ends, having one end thereof larger in diameter than the other end thereof and having a wall thickness which decreases in the same direction as the diameter of the sleeve decreases so that the heat transfer through the sleeve and tube is less adjacent the large diameter end of the sleeve than adjacent the other end thereof.

Harris, William G. (Tampa, FL)

1985-01-01T23:59:59.000Z

280

NGNP Process Heat Utilization: Liquid Metal Phase Change Heat Exchanger  

SciTech Connect (OSTI)

One key long-standing issue that must be overcome to fully realize the successful growth of nuclear power is to determine other benefits of nuclear energy apart from meeting the electricity demands. The Next Generation Nuclear Plant (NGNP) will most likely be producing electricity and heat for the production of hydrogen and/or oil retrieval from oil sands and oil shale to help in our national pursuit of energy independence. For nuclear process heat to be utilized, intermediate heat exchange is required to transfer heat from the NGNP to the hydrogen plant or oil recovery field in the most efficient way possible. Development of nuclear reactor - process heat technology has intensified the interest in liquid metals as heat transfer media because of their ideal transport properties. Liquid metal heat exchangers are not new in practical applications. An important rational for considering liquid metals is the potential convective heat transfer is among the highest known. Thus explains the interest in liquid metals as coolant for intermediate heat exchange from NGNP. For process heat it is desired that, intermediate heat exchangers (IHX) transfer heat from the NGNP in the most efficient way possible. The production of electric power at higher efficiency via the Brayton Cycle, and hydrogen production, requires both heat at higher temperatures and high effectiveness compact heat exchangers to transfer heat to either the power or process cycle. Compact heat exchangers maximize the heat transfer surface area per volume of heat exchanger; this has the benefit of reducing heat exchanger size and heat losses. High temperature IHX design requirements are governed in part by the allowable temperature drop between the outlet and inlet of the NGNP. In order to improve the characteristics of heat transfer, liquid metal phase change heat exchangers may be more effective and efficient. This paper explores the overall heat transfer characteristics and pressure drop of the phase change heat exchanger with Na as the heat exchanger coolant. In order to design a very efficient and effective heat exchanger one must optimize the design such that we have a high heat transfer and a lower pressure drop, but there is always a trade-off between them. Based on NGNP operational parameters, a heat exchanger analysis with the sodium phase change will be presented to show that the heat exchanger has the potential for highly effective heat transfer, within a small volume at reasonable cost.

Piyush Sabharwall; Mike Patterson; Vivek Utgikar; Fred Gunnerson

2008-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" 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

Radial flow heat exchanger  

DOE Patents [OSTI]

A radial flow heat exchanger (20) having a plurality of first passages (24) for transporting a first fluid (25) and a plurality of second passages (26) for transporting a second fluid (27). The first and second passages are arranged in stacked, alternating relationship, are separated from one another by relatively thin plates (30) and (32), and surround a central axis (22). The thickness of the first and second passages are selected so that the first and second fluids, respectively, are transported with laminar flow through the passages. To enhance thermal energy transfer between first and second passages, the latter are arranged so each first passage is in thermal communication with an associated second passage along substantially its entire length, and vice versa with respect to the second passages. The heat exchangers may be stacked to achieve a modular heat exchange assembly (300). Certain heat exchangers in the assembly may be designed slightly differently than other heat exchangers to address changes in fluid properties during transport through the heat exchanger, so as to enhance overall thermal effectiveness of the assembly.

Valenzuela, Javier (Hanover, NH)

2001-01-01T23:59:59.000Z

282

Convective heat flow probe  

DOE Patents [OSTI]

A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packet-type seals are provided along the probe above and below the heater pads.

Dunn, J.C.; Hardee, H.C.; Striker, R.P.

1984-01-09T23:59:59.000Z

283

The heating of the cooling flow (The feedback effervescent heating model)  

E-Print Network [OSTI]

The standard cooling flow model has predicted a large amount of cool gas in the clusters of galaxies. The failure of the Chandra and XXM-Newton telescopes to detect cooling gas (below 1-2 keV) in clusters of galaxies has suggested that some heating process must work to suppress the cooling. The most likely heating source is the heating by AGNs. There are many heating mechanisms, but we will adopt the effervescent heating model which is a result of the interaction of the bubbles inflated by AGN with the intra-cluster medium(ICM). Using the FLASH code, we have carried out time dependent simulations to investigate the effect of the heating on the suppression of the cooling in cooling flow clusters. We have found that the effervescent heating model can not balance the radiative cooling and it is an artificial model. Furthermore, the effervescent heating is a function of the ICM pressure gradient but the cooling is proportional to the gas density square and square root of the gas temperature.

Nasser Mohamed Ahmed

2007-10-10T23:59:59.000Z

284

Heat capacity at the glass transition  

E-Print Network [OSTI]

A fundamental problem of glass transition is to explain the jump of heat capacity at the glass transition temperature $T_g$ without asserting the existence of a distinct solid glass phase. This problem is also common to other disordered systems, including spin glasses. We propose that if $T_g$ is defined as the temperature at which the liquid stops relaxing at the experimental time scale, the jump of heat capacity at $T_g$ follows as a necessary consequence due to the change of system's elastic, vibrational and thermal properties. In this picture, we discuss time-dependent effects of glass transition, and identify three distinct regimes of relaxation. Our approach explains widely observed logarithmic increase of $T_g$ with the quench rate and the correlation of heat capacity jump with liquid fragility.

Kostya Trachenko; Vadim Brazhkin

2010-07-13T23:59:59.000Z

285

Microfabricated fuel heating value monitoring device  

DOE Patents [OSTI]

A microfabricated fuel heating value monitoring device comprises a microfabricated gas chromatography column in combination with a catalytic microcalorimeter. The microcalorimeter can comprise a reference thermal conductivity sensor to provide diagnostics and surety. Using microfabrication techniques, the device can be manufactured in production quantities at a low per-unit cost. The microfabricated fuel heating value monitoring device enables continuous calorimetric determination of the heating value of natural gas with a 1 minute analysis time and 1.5 minute cycle time using air as a carrier gas. This device has applications in remote natural gas mining stations, pipeline switching and metering stations, turbine generators, and other industrial user sites. For gas pipelines, the device can improve gas quality during transfer and blending, and provide accurate financial accounting. For industrial end users, the device can provide continuous feedback of physical gas properties to improve combustion efficiency during use.

Robinson, Alex L. (Albuquerque, NM); Manginell, Ronald P. (Albuquerque, NM); Moorman, Matthew W. (Albuquerque, NM)

2010-05-04T23:59:59.000Z

286

Electron Heating in Quasi-Perpendicular Shocks  

E-Print Network [OSTI]

Seventy crossings of the Earths bow shock by the THEMIS satellites have been used to study thermal electron heating in collisionless, quasi-perpendicular shocks. It was found that the temperature increase of thermal electrons differed from the magnetic field increase by factors as great as three, that the parallel electron temperature increase was not produced by parallel electric fields, and that the parallel and perpendicular electron temperature increases were the same on the average. It was also found that the perpendicular and parallel electron heating occurred simultaneously so that the isotropization time is the same as the heating time. These results cannot be explained by energy transfer from waves to electrons or by the motion of magnetized electrons through the shock. Electric field fluctuations on the scale of the electron gyro-diameter were found to be of finite amplitude in the shock ramp, which requires that the electron trajectories be more random and chaotic than orderly and adiabatic. The da...

Mozer, F S

2013-01-01T23:59:59.000Z

287

Vacuum Induction Melting Unit Induction heating is a process wherein induced eddy currents heat conductive materials. This heating  

E-Print Network [OSTI]

graphite) crucible inside the coil. The coil serves as the transformer primary and the part to be heated Principle: An outline of the induction melting system is presented here. A solid state RF power supply sends can be melted at a time. There are three main parts to the system: chiller, power unit and vacuum unit

Subramaniam, Anandh

288

Tsallis Distribution Decorated With Log-Periodic Oscillation  

E-Print Network [OSTI]

In many situations, in all branches of physics, one encounters power-like behavior of some variables which are best described by a Tsallis distribution characterized by a nonextensivity parameter $q$ and scale parameter $T$. However, there exist experimental results which can be described only by a Tsallis distributions which are additionally decorated by some log-periodic oscillating factor. We argue that such a factor can originate from allowing for a complex nonextensivity parameter $q$. The possible information conveyed by such an approach (like the occurrence of complex heat capacity, the notion of complex probability or complex multiplicative noise) will also be discussed.

Wilk, Grzegorz

2015-01-01T23:59:59.000Z

289

Tsallis Distribution Decorated With Log-Periodic Oscillation  

E-Print Network [OSTI]

In many situations, in all branches of physics, one encounters power-like behavior of some variables which are best described by a Tsallis distribution characterized by a nonextensivity parameter $q$ and scale parameter $T$. However, there exist experimental results which can be described only by a Tsallis distributions which are additionally decorated by some log-periodic oscillating factor. We argue that such a factor can originate from allowing for a complex nonextensivity parameter $q$. The possible information conveyed by such an approach (like the occurrence of complex heat capacity, the notion of complex probability or complex multiplicative noise) will also be discussed.

Grzegorz Wilk; Zbigniew Wlodarczyk

2015-01-12T23:59:59.000Z

290

EIS-0236: Extension of Comment Period | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat Pump Models |Conduct,Final9:DepartmentExtension of Comment Period EIS-0236:

291

Solar air heating system for combined DHW and space heating  

E-Print Network [OSTI]

Solar air heating system for combined DHW and space heating solar air collector PV-panel fannon-return valve DHW tank mantle cold waterhot water roof Solar Energy Centre Denmark Danish Technological Institute SEC-R-29 #12;Solar air heating system for combined DHW and space heating Søren �stergaard Jensen

292

Heat exchanger device and method for heat removal or transfer  

DOE Patents [OSTI]

Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

Koplow, Jeffrey P. (San Ramon, CA)

2012-07-24T23:59:59.000Z

293

Heat exchanger device and method for heat removal or transfer  

DOE Patents [OSTI]

Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

Koplow, Jeffrey P

2013-12-10T23:59:59.000Z

294

On a periodicity measure and superoscillations  

E-Print Network [OSTI]

The phenomenon of superoscillation, where band limited signals can oscillate over some time period with a frequency higher than the band limit, is not only very interesting but it also seems to offer many practical applications. The first reason is that the superoscillation frequency can be exploited to perform tasks beyond the limits imposed by the lower bandwidth of the signal. The second reason is that it is generic and applies to any wave form, be it optical, electrical, sonic, or quantum mechanical. For practical applications, it is important to overcome two problems. The first problem is that an overwhelming proportion of the energy goes into the non superoscillating part of the signal. The second problem is the control of the shape of the superoscillating part of the signal. The first problem has been recently addressed by optimization of the super oscillation yield, the ratio of the energy in the superoscillations to the total energy of the signal. The second problem may arise when the superoscillation, is to mimic a high frequency purely perodic signal. This may be required, for example, when a superoscillating force is to drive a harmonic oscillator at a high resonance frequency. In this paper the degree of periodicity of a signal is defined and applied to some yield optimized superoscillating signals.

Nehemia Schwartz; Moshe Schwartz

2014-02-13T23:59:59.000Z

295

E-Print Network 3.0 - a20 regulates period Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

& Control 28 (2004) 16611680 www.elsevier.comlocateeconbase Summary: of the abatement cost function as being constant for a long period of time. If the regulator could...

296

Periodic fluctuations in deep water formation due to sea ice  

E-Print Network [OSTI]

During the last ice age several quasi-periodic abrupt warming events took place. Known as Dansgaard-Oeschger (DO) events their effects were felt globally, although the North Atlantic experienced the largest temperature anomalies. Paleoclimate data shows that the fluctuations often occurred right after massive glacial meltwater releases in the North Atlantic and in bursts of three or four with progressively decreasing strengths. In this study a simple dynamical model of an overturning circulation and sea ice is developed with the goal of understanding the fundamental mechanisms that could have caused the DO events. Interaction between sea ice and the overturning circulation in the model produces self-sustained oscillations. Analysis and numerical experiments reveal that the insulating effect of sea ice causes the ocean to periodically vent out accumulated heat in the deep ocean into the atmosphere. Subjecting the model to idealized freshwater forcing mimicking Heinrich events causes modulation of the natural p...

Saha, Raj

2015-01-01T23:59:59.000Z

297

Periodic table for topological insulators and superconductors  

E-Print Network [OSTI]

Gapped phases of noninteracting fermions, with and without charge conservation and time-reversal symmetry, are classified using Bott periodicity. The symmetry and spatial dimension determines a general universality class, which corresponds to one of the 2 types of complex and 8 types of real Clifford algebras. The phases within a given class are further characterized by a topological invariant, an element of some Abelian group that can be 0, Z, or Z_2. The interface between two infinite phases with different topological numbers must carry some gapless mode. Topological properties of finite systems are described in terms of K-homology. This classification is robust with respect to disorder, provided electron states near the Fermi energy are absent or localized. In some cases (e.g., integer quantum Hall systems) the K-theoretic classification is stable to interactions, but a counterexample is also given.

Alexei Kitaev

2009-01-20T23:59:59.000Z

298

On Heat and Quality Ron Zevenhoven  

E-Print Network [OSTI]

of Technology and the Academy of Finland. I came to Finland some time ago after studies at Delft University heat and energy I learned in Finland. The result of studying technology at Delft followed by research and teaching in Finland now stands in front of you. During 13 years in Finland I learned a lot about Finns

Zevenhoven, Ron

299

Thermoelectric recovery of waste heat -- Case studies  

SciTech Connect (OSTI)

The use of waste heat as an energy source for thermoelectric generation largely removes the constraint for the wide scale application of this technology imposed by its relatively low conversion efficiency (typically about 5%). Paradoxically, in some parasitic applications, a low conversion efficiency can be viewed as a distinct advantage. However, commercially available thermoelectric modules are designed primarily for refrigerating applications and are less reliable when operated at elevated temperatures. Consequently, a major factor which determines the economic competitiveness of thermoelectric recovery of waste heat is the cost per watt divided by the mean-time between module failures. In this paper is reported the development of a waste, warm water powered thermoelectric generator, one target in a NEDO sponsored project to economically recover waste heat. As an application of this technology case studies are considered in which thermoelectric generators are operated in both active and parasitic modes to generate electrical power for a central heating system. It is concluded that, in applications when the supply of heat essentially is free as with waste heat, thermoelectrics can compete economically with conventional methods of electrical power generation. Also, in this situation, and when the generating system is operated in a parasitic mode, conversion efficiency is not an important consideration.

Rowe, M.D.; Min, G.; Williams, S.G.K.; Aoune, A. [Cardiff School of Engineering (United Kingdom). Div. of Electronic Engineering; Matsuura, Kenji [Osaka Univ., Suita, Osaka (Japan). Dept. of Electrical Engineering; Kuznetsov, V.L. [Ioffe Physical-Technical Inst., St. Petersburg (Russian Federation); Fu, L.W. [Tsinghua Univ., Beijing (China). Microelectronics Inst.

1997-12-31T23:59:59.000Z

300

Heat Transfer Enhancement for Finned-tube Heat Exchangers with Winglets  

SciTech Connect (OSTI)

This paper presents the results of an experimental study of forced convection heat transfer in a narrow rectangular duct fitted with a circular tube and/or a delta-winglet pair. The duct was designed to simulate a single passage in a fin-tube heat exchanger. Heat transfer measurements were obtained using a transient technique in which a heated airflow is suddenly introduced to the test section. High-resolution local fin-surface temperature distributions were obtained at several times after initiation of the transient using an imaging infrared camera. Corresponding local fin-surface heat transfer coefficient distributions were then calculated from a locally applied one-dimensional semi-infinite inverse heat conduction model. Heat transfer results were obtained over an airflow rate ranging from 1.51 x 10-3 to 14.0 x 10-3 kg/s. These flow rates correspond to a duct-height Reynolds number range of 670 – 6300 with a duct height of 1.106 cm and a duct width-toheight ratio, W/H, of 11.25. The test cylinder was sized such that the diameter-to-duct height ratio, D/H is 5. Results presented in this paper reveal visual and quantitative details of local fin-surface heat transfer distributions in the vicinity of a circular tube, a delta-winglet pair, and a combination of a circular tube and a delta-winglet pair. Comparisons of local and average heat transfer distributions for the circular tube with and without winglets are provided. Overall mean finsurface Nusselt-number results indicate a significant level of heat transfer enhancement associated with the deployment of the winglets with the circular cylinder. At the lowest Reynolds numbers (which correspond to the laminar operating conditions of existing geothermal air-cooled condensers), the enhancement level is nearly a factor of two. At higher Reynolds numbers, the enhancement level is close to 50%.

O'Brien, James Edward; Sohal, Manohar Singh

2000-11-01T23:59:59.000Z

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


301

Optimal Scheduling of Industrial Combined Heat and Power Plants  

E-Print Network [OSTI]

Optimal Scheduling of Industrial Combined Heat and Power Plants under Time-sensitive Electricity Prices Sumit Mitra , Lige Sun , Ignacio E. Grossmann December 24, 2012 Abstract Combined heat and power companies. However, under-utilization can be a chance for tighter interaction with the power grid, which

Grossmann, Ignacio E.

302

Planar resonant periodic orbits in Kuiper belt dynamics  

E-Print Network [OSTI]

In the framework of the planar restricted three body problem we study a considerable number of resonances associated to the Kuiper Belt dynamics and located between 30 and 48 a.u. Our study is based on the computation of resonant periodic orbits and their stability. Stable periodic orbits are surrounded by regular librations in phase space and in such domains the capture of trans-Neptunian object is possible. All the periodic orbits found are symmetric and there is evidence for the existence of asymmetric ones only in few cases. In the present work first, second and third order resonances are under consideration. In the planar circular case we found that most of the periodic orbits are stable. The families of periodic orbits are temporarily interrupted by collisions but they continue up to relatively large values of the Jacobi constant and highly eccentric regular motion exists for all cases. In the elliptic problem and for a particular eccentricity value of the primary bodies the periodic orbits are isolated. The corresponding families, where they belong to, bifurcate from specific periodic orbits of the circular problem and seem to continue up to the rectilinear problem. Both stable and unstable orbits are obtained for each case. In the elliptic problem the unstable orbits found are associated with narrow chaotic domains in phase space. The evolution of the orbits, which are located in such chaotic domains, seems to be practically regular and bounded for long time intervals.

George Voyatzis; Thomas Kotoulas

2005-02-28T23:59:59.000Z

303

Heat and Power Systems Design  

E-Print Network [OSTI]

HEAT AND POWER SYSTEMS DESIGN H. D. Spriggs and J. V. Shah, Leesburg. VA ABSTRACT The selection of heat and power systems usually does not include a thorough analysis of the process heating. cooling and power requirements. In most cases..., these process requirements are accepted as specifications before heat and power systems are selected and designed. In t~is article we describe how Process Integration using Pinch Technology can be used to understand and achieve the minimum process heating...

Spriggs, H. D.; Shah, J. V.

304

Heat distribution ceramic processing method  

DOE Patents [OSTI]

A multi-layered heat distributor system is provided for use in a microwave process. The multi-layered heat distributors includes a first inner layer of a high thermal conductivity heat distributor material, a middle insulating layer and an optional third insulating outer layer. The multi-layered heat distributor system is placed around the ceramic composition or article to be processed and located in a microwave heating system. Sufficient microwave energy is applied to provide a high density, unflawed ceramic product.

Tiegs, Terry N. (Lenoir City, TN); Kiggans, Jr., James O. (Oak Ridge, TN)

2001-01-01T23:59:59.000Z

305

Enforcement Policy Statement: Compliance Period for Regional...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

energy conservation standards for residential furnaces, central air conditioners, and heat pumps, including regional standards for different product types in indicated States....

306

Acoustical heat pumping engine  

DOE Patents [OSTI]

The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium. 2 figs.

Wheatley, J.C.; Swift, G.W.; Migliori, A.

1983-08-16T23:59:59.000Z

307

Air heating system  

DOE Patents [OSTI]

A self-starting, fuel-fired, air heating system including a vapor generator, a turbine, and a condenser connected in a closed circuit such that the vapor output from the vapor generator is conducted to the turbine and then to the condenser where it is condensed for return to the vapor generator. The turbine drives an air blower which passes air over the condenser for cooling the condenser. Also, a condensate pump is driven by the turbine. The disclosure is particularly concerned with the provision of heat exchanger and circuitry for cooling the condensed fluid output from the pump prior to its return to the vapor generator.

Primeau, John J. (19800 Seminole Rd., Euclid, OH 44117)

1983-03-01T23:59:59.000Z

308

Solar industrial process heat  

SciTech Connect (OSTI)

The aim of the assessment reported is to candidly examine the contribution that solar industrial process heat (SIPH) is realistically able to make in the near and long-term energy futures of the United States. The performance history of government and privately funded SIPH demonstration programs, 15 of which are briefly summarized, and the present status of SIPH technology are discussed. The technical and performance characteristics of solar industrial process heat plants and equipment are reviewed, as well as evaluating how the operating experience of over a dozen SIPH demonstration projects is influencing institutional acceptance and economoc projections. Implications for domestic energy policy and international implications are briefly discussed. (LEW)

Lumsdaine, E.

1981-04-01T23:59:59.000Z

309

Acoustical heat pumping engine  

DOE Patents [OSTI]

The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium.

Wheatley, John C. (Los Alamos, NM); Swift, Gregory W. (Los Alamos, NM); Migliori, Albert (Santa Fe, NM)

1983-08-16T23:59:59.000Z

310

Geothermal direct-heat utilization assistance. Quarterly project progress report, January--March 1996  

SciTech Connect (OSTI)

This report summarizes geothermal technical assistance, R&D, and technology transfer activities of the Geo-Heat Center. It describes 95 contacts with parties during this period related to technical assistance with goethermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, equipment, economics, and resources. Research activities are summarized on geothermal district heating system cost evaluation and silica waste utilization project. Outreach activities include publication of a geothermal direct use Bulletin, dissemination of information, goethermal library, technical papers and seminars, and progress monitor reports on geothermal resources and utilization.

NONE

1996-05-01T23:59:59.000Z

311

Capture of Heat Energy from Diesel Engine Exhaust  

SciTech Connect (OSTI)

Diesel generators produce waste heat as well as electrical power. About one-third of the fuel energy is released from the exhaust manifolds of the diesel engines and normally is not captured for useful applications. This project studied different waste heat applications that may effectively use the heat released from exhaust of Alaskan village diesel generators, selected the most desirable application, designed and fabricated a prototype for performance measurements, and evaluated the feasibility and economic impact of the selected application. Exhaust flow rate, composition, and temperature may affect the heat recovery system design and the amount of heat that is recoverable. In comparison with the other two parameters, the effect of exhaust composition may be less important due to the large air/fuel ratio for diesel engines. This project also compared heat content and qualities (i.e., temperatures) of exhaust for three types of fuel: conventional diesel, a synthetic diesel, and conventional diesel with a small amount of hydrogen. Another task of this project was the development of a computer-aided design tool for the economic analysis of selected exhaust heat recovery applications to any Alaskan village diesel generator set. The exhaust heat recovery application selected from this study was for heating. An exhaust heat recovery system was fabricated, and 350 hours of testing was conducted. Based on testing data, the exhaust heat recovery heating system showed insignificant effects on engine performance and maintenance requirements. From measurements, it was determined that the amount of heat recovered from the system was about 50% of the heat energy contained in the exhaust (heat contained in exhaust was evaluated based on environment temperature). The estimated payback time for 100% use of recovered heat would be less than 3 years at a fuel price of $3.50 per gallon, an interest rate of 10%, and an engine operation of 8 hours per day. Based on experimental data, the synthetic fuel contained slightly less heat energy and fewer emissions. Test results obtained from adding different levels of a small amount of hydrogen into the intake manifold of a diesel-operated engine showed no effect on exhaust heat content. In other words, both synthetic fuel and conventional diesel with a small amount of hydrogen may not have a significant enough effect on the amount of recoverable heat and its feasibility. An economic analysis computer program was developed on Visual Basic for Application in Microsoft Excel. The program was developed to be user friendly, to accept different levels of input data, and to expand for other heat recovery applications (i.e., power, desalination, etc.) by adding into the program the simulation subroutines of the desired applications. The developed program has been validated using experimental data.

Chuen-Sen Lin

2008-12-31T23:59:59.000Z

312

Heat treatment of exchangers to remove coke  

SciTech Connect (OSTI)

This patent describes a process for preparing furfural coke for removal from metallic surfaces. It comprises: heating the furfural coke without causing an evolution of heat capable of undesirably altering metallurgical properties of the surfaces in the presence of a gas containing molecular oxygen at a sufficient temperature below 800{degrees}F (427{degrees}C) for a sufficient time to change the crush strength of the coke so as to permit removal with a water jet at a pressure of five thousand pounds per square inch.

Turner, J.D.

1990-02-20T23:59:59.000Z

313

Induction heaters used to heat subsurface formations  

DOE Patents [OSTI]

A heating system for a subsurface formation includes an elongated electrical conductor located in the subsurface formation. The electrical conductor extends between at least a first electrical contact and a second electrical contact. A ferromagnetic conductor at least partially surrounds and at least partially extends lengthwise around the electrical conductor. The electrical conductor, when energized with time-varying electrical current, induces sufficient electrical current flow in the ferromagnetic conductor such that the ferromagnetic conductor resistively heats to a temperature of at least about 300.degree. C.

Nguyen, Scott Vinh (Houston, TX); Bass, Ronald M. (Houston, TX)

2012-04-24T23:59:59.000Z

314

Characteristics of cyclic heat release variability in the transition from spark ignition to HCCI in a gasoline engine  

SciTech Connect (OSTI)

We study selected examples of previously published cyclic heat-release measurements from a single-cylinder gasoline engine as stepwise valve timing adjustments were made to shift from spark ignited (SI) combustion to homogeneous charge compression ignition (HCCI). Wavelet analysis of the time series, combined with conventional statistics and multifractal analysis, revealed previously undocumented features in the combustion variability as the shift occurred. In the spark-ignition combustion mode, the heat-release variations were very small in amplitude and exhibited more persistent low-frequency oscillations with intermittent high-frequency bursts. In the HCCI combustion mode, the amplitude of the heat-release variations again was small and involved mainly low-frequency oscillations. At intermediate states between SI and HCCI, a wide range of very large-amplitude oscillations occurred, including both persistent low-frequency periodicities and intermittent high-frequency bursts. It appears from these results that real-time wavelet decomposition of engine cylinder pressure measurements may be useful for on-board tracking of SI HCCI combustion regime shifts.

Sen, Asok K [Indiana University; Litak, Grzegorz [Technical University of Lublin; Edwards, Kevin Dean [ORNL; FINNEY, Charles E A [ORNL; Daw, C Stuart [ORNL; Wagner, Robert M [ORNL

2011-01-01T23:59:59.000Z

315

Heat driven heat pump using paired ammoniated salts  

SciTech Connect (OSTI)

A cycle for a heat driven heat pump using two salts CaCl/sup 2/.8NH/sup 3/, and ZnCl/sup 2/.4NH3 which may reversibly react with ammonia with the addition or evolution of heat. These salts were chosen so that both ammoniation processes occur at the same temperature so that the heat evolved may be used for comfort heating. The heat to drive the system need only be slightly hotter than 122 C. The low temperature source need only be slightly warmer than 0 C.

Dunlap, R.M.

1980-08-29T23:59:59.000Z

316

Heat-transfer coefficients in agitated vessels. Latent heat models  

SciTech Connect (OSTI)

Latent heat models were developed to calculate heat-transfer coefficients in agitated vessels for two cases: (1) heating with a condensable fluid flowing through coils and jackets; (2) vacuum reflux cooling with an overhead condenser. In either case the mathematical treatment, based on macroscopic balances, requires no iterative schemes. In addition to providing heat-transfer coefficients, the models predict flow rates of service fluid through the coils and jackets, estimate the percentage of heat transfer due to latent heat, and compute reflux rates.

Kumpinsky, E. [Ashland Chemical Co., Columbus, OH (United States)] [Ashland Chemical Co., Columbus, OH (United States)

1996-03-01T23:59:59.000Z

317

Experimental Research on Solar Assisted Heat Pump Heating System with Latent Heat Storage  

E-Print Network [OSTI]

-reaching meaning of solving energy and environment problems if new type energy conservation and environment protection heating system ? solar assisted ground-source heat pump (SAGHP) heating system with a latent heat storage tank will be practical... was established at the laboratory of construction energy conservation in Harbin Institute of Technology (HIT) in 2004. It added a latent heat storage tank in original SAGHP system. The schematic diagram of the system is shown in Figure 1. The experimental...

Han, Z.; Zheng, M.; Liu, W.; Wang, F.

2006-01-01T23:59:59.000Z

318

Wastewater heat recovery apparatus  

DOE Patents [OSTI]

A heat recovery system is described with a heat exchanger and a mixing valve. A drain trap includes a heat exchanger with an inner coiled tube, baffle plate, wastewater inlet, wastewater outlet, cold water inlet, and preheated water outlet. Wastewater enters the drain trap through the wastewater inlet, is slowed and spread by the baffle plate, and passes downward to the wastewater outlet. Cold water enters the inner tube through the cold water inlet and flows generally upward, taking on heat from the wastewater. This preheated water is fed to the mixing valve, which includes a flexible yoke to which are attached an adjustable steel rod, two stationary zinc rods, and a pivoting arm. The free end of the arm forms a pad which rests against a valve seat. The rods and pivoting arm expand or contract as the temperature of the incoming preheated water changes. The zinc rods expand more than the steel rod, flexing the yoke and rotating the pivoting arm. The pad moves towards the valve seat as the temperature of the preheated water rises, and away as the temperature falls, admitting a variable amount of hot water to maintain a nearly constant average process water temperature. 6 figs.

Kronberg, J.W.

1992-09-01T23:59:59.000Z

319

Wastewater heat recovery apparatus  

DOE Patents [OSTI]

A heat recovery system with a heat exchanger and a mixing valve. A drain trap includes a heat exchanger with an inner coiled tube, baffle plate, wastewater inlet, wastewater outlet, cold water inlet, and preheated water outlet. Wastewater enters the drain trap through the wastewater inlet, is slowed and spread by the baffle plate, and passes downward to the wastewater outlet. Cold water enters the inner tube through the cold water inlet and flows generally upward, taking on heat from the wastewater. This preheated water is fed to the mixing valve, which includes a flexible yoke to which are attached an adjustable steel rod, two stationary zinc rods, and a pivoting arm. The free end of the arm forms a pad which rests against a valve seat. The rods and pivoting arm expand or contract as the temperature of the incoming preheated water changes. The zinc rods expand more than the steel rod, flexing the yoke and rotating the pivoting arm. The pad moves towards the valve seat as the temperature of the preheated water rises, and away as the temperature falls, admitting a variable amount of hot water to maintain a nearly constant average process water temperature.

Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801)

1992-01-01T23:59:59.000Z

320

Quality of monitoring of stochastic events by periodic and ...  

E-Print Network [OSTI]

infeasible to transmit sensor data over long distances, or in an underground system of ... the case of static sensors, their placement to best protect people has been ... function of the event dynamics and type of events: (1) What is the QoM of a ... a class of periodic coverage algorithms considering the travel time overhead.

David K. Y. Yau, Nung Kwan Yip, Chris Y. T. Ma, Nageswara S. V. Rao, Mallikarjun Shankar

2010-08-28T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" 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

Passive ice freezing-releasing heat pipe. [Patent application  

DOE Patents [OSTI]

A heat pipe device has been developed which permits completely passive ice formation and periodic release of ice without requiring the ambient temperature to rise above the melting point of water. This passive design enables the maximum amount of cooling capacity to be stored in the tank.

Gorski, A.J.; Schertz, W.W.

1980-09-29T23:59:59.000Z

322

Residential GSHPs: Efficiency With Short Payback Periods  

SciTech Connect (OSTI)

This article discusses ground source heat pumps (GSHPs) for residential application as an alternative to conventional HVAC systems. A listing of current space heating energy sources are presented which are then followed by a technology overview as advances have made GSHPs more efficient. The article concludes with potential energy savings offered by GSHPs and a brief market overview.

Cooperman, Alissa; Dieckmann, John; Brodrick, James

2012-04-30T23:59:59.000Z

323

The Use of Infrared Technology To Detect Heat Loss  

E-Print Network [OSTI]

. Some of todays more sophisticated infrared instruments are real-time and produce "heat-pictures". These are representations of objects with surface temperatures appearing as patterns upon objects....

Faulkner, K.

1979-01-01T23:59:59.000Z

324

City of Tallahassee Utilities- Solar Water Heating Rebate  

Broader source: Energy.gov [DOE]

The City of Tallahassee Utilities offers a $450 rebate to homeowners* and homebuilders who install a solar water-heating system. This rebate may be applied to a first-time installation or to the...

325

Design Method for the Heating/Cooling Coil in the AHU Based on Fuzzy Logic - Part Two: Design of the Minimum Heat-Exchanging Unit  

E-Print Network [OSTI]

Zhang Yongpan Chen Zhen Liang Ph.D. Professor Doctoral Candidate Instructor School of Municipal & Environmental Eng, Harbin Institute of Technology Harbin P. R. China, 150090 zhangjili@hit.edu.cn Abstract: Considering a heating/cooling coil... heat indoor, as is given by Equation (5) (noted in difference scheme), where Qr denotes sensible heat amount indoor (KW); ? denotes time variable (s); ? r denotes air density indoor (Kg/m3); CP denotes air specific heat at constant pressure (KJ...

Zhang, J.; Chen, Y.; Liang, Z.

2006-01-01T23:59:59.000Z

326

Quantum optomechanical piston engines powered by heat  

E-Print Network [OSTI]

We study two different models of optomechanical systems where a temperature gradient between two radiation baths is exploited for inducing self-sustained coherent oscillations of a mechanical resonator. Viewed from a thermodynamic perspective, such systems represent quantum instances of self-contained thermal machines converting heat into a periodic mechanical motion and thus they can be interpreted as nano-scale analogues of macroscopic piston engines. Our models are potentially suitable for testing fundamental aspects of quantum thermodynamics in the laboratory and for applications in energy efficient nanotechnology.

Andrea Mari; Alessandro Farace; Vittorio Giovannetti

2014-07-31T23:59:59.000Z

327

Low Level Heat Recovery Through Heat Pumps and Vapor Recompression  

E-Print Network [OSTI]

The intent of this paper is to examine the methods and economics of recovering low level heat through heat pumps and vapor recompression. Actual commercially available equipment is considered to determine the near-term and future economic viability...

Gilbert, J.

1980-01-01T23:59:59.000Z

328

TRANSPARENT HEAT MIRRORS FOR PASSIVE SOLAR HEATING APPLICATIONS  

E-Print Network [OSTI]

heating purposes. BACKGROUND The reduction of heat transfer rates by the use of thermal infraredheating applications should become available on the marketplace. Due to their high reflectivity to thermal infrared

Selkowitz, S.

2011-01-01T23:59:59.000Z

329

Cedarville School District Retrofit of Heating and Cooling Systems with Geothermal Heat Pumpsand Ground Source Water Loops  

Broader source: Energy.gov [DOE]

Project objectives: Improve the indoor air quality and lower the cost of cooling and heating the buildings that make up the campus of Cedarville High School and Middle School.; Provide jobs; and reduce requirements of funds for the capital budget of the School District; and thus give relief to taxpayers in this rural region during a period of economic recession.

330

Numerical Modelling of Combined Heat Transfers in a Double Skin Faade -Full Scale Laboratory  

E-Print Network [OSTI]

, thermal comfort, visual comfort or energy gain [1]. In the current context of global warming, depletion heat transfers are also taken into account to obtain a global coupling between the different phenomena on two levels: during the winter period, the solar energy is used to heat the air in the façade [2], and

331

Study of Applications of Solar Heating Systems with Seasonal Storage in China  

E-Print Network [OSTI]

the ratio of volume of seasonal storage tank to collector areas is 3~5, the system performance is optimal for many places in China; 3) the obtained solar heat is mainly dependent on the solar irradiance, length of heating period and ambient temperature...

Yu, G.; Zhao, X.; Chen, P.

2006-01-01T23:59:59.000Z

332

Heat Transfer Derivation of differential equations for heat transfer conduction  

E-Print Network [OSTI]

) or kW *h or Btu. U is the change in stored energy, in units of kW *h (kWh) or Btu. qx is the heat conducted (heat flux) into the control volume at surface edge x, in units of kW/m2 or Btu/(h-ft2). qx volume is positive), in kW/m3 or Btu/(h-ft3) (a heat sink, heat drawn out of the volume, is negative

Veress, Alexander

333

Effects of slitted fins on the heat transfer and pressure drop characteristics of a compact heat exchanger  

SciTech Connect (OSTI)

A compact heat exchanger which consists of air-cooled aluminum fins and copper tubes circulating refrigerant has been used in a cooling system for a long time. There are two key parameters to be seriously considered for a design of the heat exchanger and its performance improvement. These are the heat transfer rate and pressure drop coefficient which varies with the change of the tube size, its arrangement and the fin configuration. In here, a numerical study was carried to understand the effect of the fin configuration on the heat transfer and pressure drop of the heat exchanger. The diameter and the arrangement of tubes were fixed but three different types of the fin configuration were used to see its effect on the heat transfer capacity and the static pressure drop. The calculation results were compared with that of a flat plate fin. From the comparison, it was found that the slitted fins have higher pressure drop; however, they have higher heat transfer rate. It means that the simpler of the fin configuration, the lower pressure drop and heat transfer coefficients are obtained. It is mainly due to the discretisation of the thermal boundary layer on the fin surface to maximize the heat transfer to air. The slitted sides of fins act like obstacles in the airflow path. From the experimental result, it was found that the same trend in the variation of the heat transfer rate and the pressure drop with the change of the fin configuration was obtained.

Kim, C.H.; Yun, J.Y. [LG Electronics Living System Research Lab., Seoul (Korea, Republic of)

1996-12-31T23:59:59.000Z

334

Heat-transfer coefficients in agitated vessels. Sensible heat models  

SciTech Connect (OSTI)

Transient models for sensible heat were developed to assess the thermal performance of agitated vessels with coils and jackets. Performance is quantified with the computation of heat-transfer coefficients by introducing vessel heating and cooling data into model equations. Of the two model categories studied, differential and macroscopic, the latter is preferred due to mathematical simplicity and lower sensitivity to experimental data variability.

Kumpinsky, E. [Ashland Chemical Co., Columbus, OH (United States). Research and Development Dept.

1995-12-01T23:59:59.000Z

335

Heat engine Device that transforms heat into work.  

E-Print Network [OSTI]

, and rocket engines are heat engines. So are steam engines and turbines #12;2 refrigerator Device that uses by steam turbines. Steam turbines, jet engines and rocket engines use a Brayton cycle #12;4 Steam turbines1 Heat engine Device that transforms heat into work. It requires two energy reservoirs at different

Winokur, Michael

336

Fast reactor power plant design having heat pipe heat exchanger  

DOE Patents [OSTI]

The invention relates to a pool-type fission reactor power plant design having a reactor vessel containing a primary coolant (such as liquid sodium), and a steam expansion device powered by a pressurized water/steam coolant system. Heat pipe means are disposed between the primary and water coolants to complete the heat transfer therebetween. The heat pipes are vertically oriented, penetrating the reactor deck and being directly submerged in the primary coolant. A U-tube or line passes through each heat pipe, extended over most of the length of the heat pipe and having its walls spaced from but closely proximate to and generally facing the surrounding walls of the heat pipe. The water/steam coolant loop includes each U-tube and the steam expansion device. A heat transfer medium (such as mercury) fills each of the heat pipes. The thermal energy from the primary coolant is transferred to the water coolant by isothermal evaporation-condensation of the heat transfer medium between the heat pipe and U-tube walls, the heat transfer medium moving within the heat pipe primarily transversely between these walls.

Huebotter, P.R.; McLennan, G.A.

1984-08-30T23:59:59.000Z

337

Fast reactor power plant design having heat pipe heat exchanger  

DOE Patents [OSTI]

The invention relates to a pool-type fission reactor power plant design having a reactor vessel containing a primary coolant (such as liquid sodium), and a steam expansion device powered by a pressurized water/steam coolant system. Heat pipe means are disposed between the primary and water coolants to complete the heat transfer therebetween. The heat pipes are vertically oriented, penetrating the reactor deck and being directly submerged in the primary coolant. A U-tube or line passes through each heat pipe, extended over most of the length of the heat pipe and having its walls spaced from but closely proximate to and generally facing the surrounding walls of the heat pipe. The water/steam coolant loop includes each U-tube and the steam expansion device. A heat transfer medium (such as mercury) fills each of the heat pipes. The thermal energy from the primary coolant is transferred to the water coolant by isothermal evaporation-condensation of the heat transfer medium between the heat pipe and U-tube walls, the heat transfer medium moving within the heat pipe primarily transversely between these walls.

Huebotter, Paul R. (Western Springs, IL); McLennan, George A. (Downers Grove, IL)

1985-01-01T23:59:59.000Z

338

An experimental investigation of a periodic impingement technique for heat transfer enhancement  

E-Print Network [OSTI]

diameter ]t viscosity of air [N s m '] p air density [kg m ] p air density [kg m'] p?air density at orifice fkg m ] TABLE OF CONTENTS Page 1 INTRODUCTION. . 2 EXPERIMENTAI. APPARATUS. . 3 EXPERIMENTALPROCEDURE 4 DATA REDUCTION. 19 5 RESULTS... AND DISCUSSION. . 30 5. 1 5. 2 5. 3 5. 4 5. 5 5. 6 Test Channel with No Deflectors. . Type 1 Pitch. . . Type 2 Pitch. . Average Relative Nusselt Number and Stanton Number. . . . . . Friction Factor. . Thermal Performance. 30 37 54 72 74 74 6...

Valant, Michael Eric

1995-01-01T23:59:59.000Z

339

Property:Building/SPPurchasedEngyForPeriodMwhYrDstrtHeating | Open Energy  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformationInyo County, California |SPElectrtyUsePercRefrigeration Jump to:Information

340

Hydraulic Characteristics of the Lower Snake River During Periods of Juvenile Fall Chinook Migration  

SciTech Connect (OSTI)

This report documents a four-year study to assess hydraulic conditions in the lower Snake River. The work was conducted for the Bonneville Power Administration, U.S. Department of Energy, by the Pacific Northwest National Laboratory. Cold water released from the Dworshak Reservoir hypolimnion during mid- to late-summer months cools the Clearwater River far below equilibrium temperature. The volume of released cold water augments the Clearwater River, and the combined total discharge is on the order of the Snake River discharge when the two rivers meet at their confluence near the upstream edge of Lower Granite Reservoir. With typical temperature differences between the Clearwater and Snake rivers of 10°C or more during July and August, the density difference between the two rivers during summer flow augmentation periods is sufficient to stratify Lower Granite Reservoir as well as the other three reservoirs downstream. Because cooling of the river is desirable for migrating juvenile fall Chinook salmon (Oncorhynchus tshawytscha) during this same time period, the amount of mixing and cold water entrained into Lower Granite Reservoir’s epilimnion at the Clearwater/Snake River confluence is of key biological importance to juvenile fall Chinook salmon. Data collected during this project indicates the three reservoirs downstream of Lower Granite also stratify as direct result of flow augmentation from Dworshak Reservoir. These four lower Snake reservoirs are also heavily influenced by wind forcing at the water’s surface, and during periods of low river discharge, often behave like a two-layer lake. During these periods of stratification, lower river discharge, and wind forcing, the water in the upper layer of the reservoir is held in place or moves slightly upstream. This upper layer is also exposed to surface heating and may warm up to temperatures close to equilibrium temperature. The depth of this upper warm layer and its direction of travel may also be of key biological importance to juvenile fall Chinook salmon. This report describes field data collection, modeling, and analysis of hydrodynamic and temperature conditions in the Lower Granite Reservoir during the summer flow augmentation periods of 2002, 2003, and 2004 plus a brief one-week period in 2005 of Lower Monumental, Little Goose, and Lower Granite Reservoirs. Circulation patterns in all four lower Snake River reservoirs were numerically simulated for periods of 2002, 2003, 2004, and 2005 using CE-QUAL-W2. Simulation results show that these models are sufficiently capable of matching diurnal and long term temperature and velocity changes in the reservoirs. In addition, the confluence zone of the Clearwater and Snake rivers was modeled using the 3-D model Flow3-D. This model was used to better understand mixing processing and entrainment. Once calibrated and validated, the reservoir models were used to investigate downstream impacts of alternative reservoir operation schemes, such as increasing or decreasing the ratio of Clearwater to Snake discharge. Simulation results were also linked with the particle tracking model FINS to better understand alterations of integrated metrics due to alternative operation schemes. These findings indicate that significant alterations in water temperature throughout the lower Snake River are possible by altering hypolimnetic discharges from Dworshak Reservoir and may have a significant impact on the behavior of migrating juvenile fall Chinook salmon during periods of flow augmentation.

Cook, Chris B.; Dibrani, Berhon; Richmond, Marshall C.; Bleich, Matthew D.; Titzler, P. Scott; Fu, Tao

2006-01-30T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" 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

Geothermal Heat Pump Grant Program  

Broader source: Energy.gov [DOE]

The Maryland Energy Administration (MEA) offers rebates of $3,000 for residential geothermal heat pump systems and up to $4,500 for non-residential geothermal heat pump systems. The residential...

342

Heat Pipes: An Industrial Application  

E-Print Network [OSTI]

This paper reviews the basics of heat pipe exchangers. Included are how they are constructed, how they operate, where they have application, and various aspects of evaluating a potential application. After discussing the technical aspects of heat...

Murray, F.

1984-01-01T23:59:59.000Z

343

Challenges in Industrial Heat Recovery  

E-Print Network [OSTI]

This presentation will address several completed and working projects involving waste heat recovery in a chemical plant. Specific examples will be shown and some of the challenges to successful implementation and operation of heat recovery projects...

Dafft, T.

2007-01-01T23:59:59.000Z

344

Heat Pumps - Theory and Applications  

E-Print Network [OSTI]

compressors (heat pumps) with actual applications in Monsanto. Guidelines for possible application areas are drawn from the analysis, and conclusions are drawn both about the usefulness of exergy analysis and about the heat pump application areas....

Altin, M.

1982-01-01T23:59:59.000Z

345

Faculty Positions Heat Transfer and  

E-Print Network [OSTI]

Faculty Positions Heat Transfer and Thermal/Energy Sciences Naval Postgraduate School Monterey-track faculty position at the assistant professor level in the areas of Heat Transfer and Thermal/Fluid Sciences

346

Residential Solar Water Heating Rebates  

Broader source: Energy.gov [DOE]

New Hampshire offers a rebate for residential solar water-heating systems and solar space-heating systems. The rebate is equal to $1,500 for systems with an annual estimated output of 5.5 MMBTU to...

347

Can You Afford Heat Recovery?  

E-Print Network [OSTI]

many companies to venture into heat recovery projects without due consideration of the many factors involved. Many of these efforts have rendered less desirable results than expected. Heat recovery in the form of recuperation should be considered...

Foust, L. T.

1983-01-01T23:59:59.000Z

348

Low Level Heat Recovery Technology  

E-Print Network [OSTI]

level heat recovery technology. This paper discusses heat distribution systems, latest developments in absorption refrigeration and organic Rankine cycles, and pressure, minimization possibilities. The relative merits and economics of the various...

O'Brien, W. J.

1982-01-01T23:59:59.000Z

349

Heat transfer probe  

DOE Patents [OSTI]

Apparatuses, systems, methods, and computer code for, among other things, monitoring the health of samples such as the brain while providing local cooling or heating. A representative device is a heat transfer probe, which includes an inner channel, a tip, a concentric outer channel, a first temperature sensor, and a second temperature sensor. The inner channel is configured to transport working fluid from an inner inlet to an inner outlet. The tip is configured to receive at least a portion of the working fluid from the inner outlet. The concentric outer channel is configured to transport the working fluid from the inner outlet to an outer outlet. The first temperature sensor is coupled to the tip, and the second temperature sensor spaced apart from the first temperature sensor.

Frank, Jeffrey I.; Rosengart, Axel J.; Kasza, Ken; Yu, Wenhua; Chien, Tai-Hsin; Franklin, Jeff

2006-10-10T23:59:59.000Z

350

Optical heat flux gauge  

DOE Patents [OSTI]

A heat flux gauge is disclosed comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator, wherein each thermographic layer comprises a plurality of respective thermographic sensors in a juxtaposed relationship with respect to each other. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable. 9 figures.

Noel, B.W.; Borella, H.M.; Cates, M.R.; Turley, W.D.; MacArthur, C.D.; Cala, G.C.

1991-04-09T23:59:59.000Z

351

Guide to Combined Heat and Power Systems for Boiler Owners and Operators  

SciTech Connect (OSTI)

Combined heat and power (CHP) or cogeneration is the sequential production of two forms of useful energy from a single fuel source. In most CHP applications, chemical energy in fuel is converted to both mechanical and thermal energy. The mechanical energy is generally used to generate electricity, while the thermal energy or heat is used to produce steam, hot water, or hot air. Depending on the application, CHP is referred to by various names including Building Cooling, Heating, and Power (BCHP); Cooling, Heating, and Power for Buildings (CHPB); Combined Cooling, Heating, and Power (CCHP); Integrated Energy Systems (IES), or Distributed Energy Resources (DER). The principal technical advantage of a CHP system is its ability to extract more useful energy from fuel compared to traditional energy systems such as conventional power plants that only generate electricity and industrial boiler systems that only produce steam or hot water for process applications. By using fuel energy for both power and heat production, CHP systems can be very energy efficient and have the potential to produce electricity below the price charged by the local power provider. Another important incentive for applying cogeneration technology is to reduce or eliminate dependency on the electrical grid. For some industrial processes, the consequences of losing power for even a short period of time are unacceptable. The primary objective of the guide is to present information needed to evaluate the viability of cogeneration for new or existing industrial, commercial, and institutional (ICI) boiler installations and to make informed CHP equipment selection decisions. Information presented is meant to help boiler owners and operators understand the potential benefits derived from implementing a CHP project and recognize opportunities for successful application of cogeneration technology. Topics covered in the guide follow: (1) an overview of cogeneration technology with discussions about benefits of applying cogeneration technology and barriers to implementing cogeneration technology; (2) applicable federal regulations and permitting issues; (3) descriptions of prime movers commonly used in CHP applications, including discussions about design characteristics, heat-recovery options and equipment, fuels and emissions, efficiency, maintenance, availability, and capital cost; (4) electrical generators and electrical interconnection equipment; (5) cooling and dehumidification equipment; (6) thermodynamic cycle options and configurations; (7) steps for evaluating the technical and economic feasibility of applying cogeneration technology; and (8) information sources.

Oland, CB

2004-08-19T23:59:59.000Z

352

Photoionization Heating of Nova Ejecta by the Post-Outburst Supersoft Source  

E-Print Network [OSTI]

The expanding ejecta from a classical nova remains hot enough ($\\sim10^{4}\\, {\\rm K}$) to be detected in thermal radio emission for up to years after the cessation of mass loss triggered by a thermonuclear instability on the underlying white dwarf (WD). Nebular spectroscopy of nova remnants confirms the hot temperatures observed in radio observations. During this same period, the unstable thermonuclear burning transitions to a prolonged period of stable burning of the remnant hydrogen-rich envelope, causing the WD to become, temporarily, a super-soft X-ray source. We show that photoionization heating of the expanding ejecta by the hot WD maintains the observed nearly constant temperature of $(1-4)\\times10^4\\mathrm{~K}$ for up to a year before an eventual decline in temperature due to either the cessation of the supersoft phase or the onset of a predominantly adiabatic expansion. We simulate the expanding ejecta using a one-zone model as well as the Cloudy spectral synthesis code, both incorporating the time-d...

Cunningham, Timothy; Bildsten, Lars

2015-01-01T23:59:59.000Z

353

Industrial Heat Recovery - 1982  

E-Print Network [OSTI]

like: "Vertical, natural circulation boilers are intrinsically mbre reliable than horizontal, forced circula tion boilers.",4 and " it will be seen that horizontal tubes have much lower heat fluxes at burnout than do vertical ones, though...-steam density difference dia gram (Figure 1) has been presented repeat edly in order to indicate a significant density difference between the two phases (even close to the critical pressure) which induces natural circulation. However, this diagra...

Csathy, D.

1982-01-01T23:59:59.000Z

354

Heat flux dynamics in dissipative cascaded systems  

E-Print Network [OSTI]

We study the dynamics of heat flux in the thermalization process of a pair of identical quantum system that interact dissipatively with a reservoir in a {\\it cascaded} fashion. Despite the open dynamics of the bipartite system S is globally Lindbladian, one of the subsystems "sees" the reservoir in a state modified by the interaction with the other subsystem and hence it undergoes a non-Markovian dynamics. As a consequence, the heat flow exhibits a non-exponential time behaviour which can greatly deviate from the case where each party is independently coupled to the reservoir. We investigate both thermal and correlated initial states of $S$ and show that the presence of correlations at the beginning can considerably affect the heat flux rate. We carry out our study in two paradigmatic cases -- a pair of harmonic oscillators with a reservoir of bosonic modes and two qubits with a reservoir of fermionic modes -- and compare the corresponding behaviours. In the case of qubits and for initial thermal states, we find that the trace distance discord is at any time interpretable as the correlated contribution to the total heat flux.

Salvatore Lorenzo; Alessandro Farace; Francesco Ciccarello; G. Massimo Palma; Vittorio Giovannetti

2014-12-19T23:59:59.000Z

355

Phase transitions in full counting statistics for periodic pumping  

E-Print Network [OSTI]

We discuss the problem of full counting statistics for periodic pumping. The probability generating function is usually defined on a circle of the "physical" values of the counting parameter, with its periodicity corresponding to charge quantization. The extensive part of the generating function can either be an analytic function on this circle or have singularities. These two cases may be interpreted as different thermodynamic phases in time domain. We discuss several examples of phase transitions between these phases for classical and quantum systems. Finally, we prove a criterion for the "analytic" phase in the problem of a quantum pump for noninteracting fermions.

Dmitri A. Ivanov; Alexander G. Abanov

2010-07-16T23:59:59.000Z

356

QUASI-PERIODIC PROPAGATING SIGNALS IN THE SOLAR CORONA: THE SIGNATURE OF MAGNETOACOUSTIC WAVES OR HIGH-VELOCITY UPFLOWS?  

SciTech Connect (OSTI)

Since the discovery of quasi-periodic propagating oscillations with periods of order 3-10 minutes in coronal loops with TRACE and SOHO/EIT (and later with STEREO/EUVI and Hinode/EIS), they have been almost universally interpreted as evidence for propagating slow-mode magnetoacoustic waves in the low plasma {beta} coronal environment. Here we show that this interpretation is not unique, and that for coronal loops associated with plage regions (as opposed to sunspots), the presence of magnetoacoustic waves may not be the only cause for the observed quasi-periodicities. We focus instead on the ubiquitous, faint upflows at 50-150 km s{sup -1} that were recently discovered as blueward asymmetries of spectral line profiles in footpoint regions of coronal loops, and as faint disturbances propagating along coronal loops in EUV/X-ray imaging time series. These faint upflows are most likely driven from below and have been associated with chromospheric jets that are (partially) rapidly heated to coronal temperatures at low heights. These two scenarios (waves versus flows) are difficult to differentiate using only imaging data, but careful analysis of spectral line profiles indicates that faint upflows are likely responsible for some of the observed quasi-periodic oscillatory signals in the corona. We show that recent EIS measurements of intensity and velocity oscillations of coronal lines (which had previously been interpreted as direct evidence for propagating waves) are actually accompanied by significant oscillations in the line width that are driven by a quasi-periodically varying component of emission in the blue wing of the line. This faint additional component of blue-shifted emission quasi-periodically modulates the peak intensity and line centroid of a single Gaussian fit to the spectral profile with the same small amplitudes (respectively a few percent of background intensity and a few km s{sup -1}) that were previously used to infer the presence of slow-mode magnetoacoustic waves. Our results indicate that it is possible that a significant fraction of the quasi-periodicities observed with coronal imagers and spectrographs that have previously been interpreted as propagating magnetoacoustic waves are instead caused by these upflows. The different physical cause for coronal oscillations would significantly impact the prospects of successful coronal seismology using propagating disturbances in coronal loops.

De Pontieu, Bart [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover Street, Org. ADBS, Bldg. 252, Palo Alto, CA 94304 (United States); McIntosh, Scott W., E-mail: bdp@lmsal.co, E-mail: mscott@ucar.ed [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)

2010-10-20T23:59:59.000Z

357

[Waste water heat recovery system  

SciTech Connect (OSTI)

The production capabilities for and field testing of the heat recovery system are described briefly. Drawings are included.

Not Available

1993-04-28T23:59:59.000Z

358

Seismic isolation of two dimensional periodic foundations  

SciTech Connect (OSTI)

Phononic crystal is now used to control acoustic waves. When the crystal goes to a larger scale, it is called periodic structure. The band gaps of the periodic structure can be reduced to range from 0.5?Hz to 50?Hz. Therefore, the periodic structure has potential applications in seismic wave reflection. In civil engineering, the periodic structure can be served as the foundation of upper structure. This type of foundation consisting of periodic structure is called periodic foundation. When the frequency of seismic waves falls into the band gaps of the periodic foundation, the seismic wave can be blocked. Field experiments of a scaled two dimensional (2D) periodic foundation with an upper structure were conducted to verify the band gap effects. Test results showed the 2D periodic foundation can effectively reduce the response of the upper structure for excitations with frequencies within the frequency band gaps. When the experimental and the finite element analysis results are compared, they agree well with each other, indicating that 2D periodic foundation is a feasible way of reducing seismic vibrations.

Yan, Y.; Mo, Y. L., E-mail: yilungmo@central.uh.edu [University of Houston, Houston, Texas 77004 (United States); Laskar, A. [Indian Institute of Technology Bombay, Powai, Mumbai (India); Cheng, Z.; Shi, Z. [Beijing Jiaotong University, Beijing (China); Menq, F. [University of Texas, Austin, Texas 78712 (United States); Tang, Y. [Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2014-07-28T23:59:59.000Z

359

Heat and mass transfer considerations in advanced heat pump systems  

SciTech Connect (OSTI)

Advanced heat-pump cycles are being investigated for various applications. However, the working media and associated thermal design aspects require new concepts for maintaining high thermal effectiveness and phase equilibrium for achieving maximum possible thermodynamic advantages. In the present study, the heat- and mass-transfer processes in two heat-pump systems -- those based on absorption processes, and those using refrigerant mixtures -- are analyzed. The major technical barriers for achieving the ideal performance predicted by thermodynamic analysis are identified. The analysis provides general guidelines for the development of heat- and mass-transfer equipment for advanced heat-pump systems.

Panchal, C.B.; Bell, K.J.

1992-08-01T23:59:59.000Z

360

Heat and mass transfer considerations in advanced heat pump systems  

SciTech Connect (OSTI)

Advanced heat-pump cycles are being investigated for various applications. However, the working media and associated thermal design aspects require new concepts for maintaining high thermal effectiveness and phase equilibrium for achieving maximum possible thermodynamic advantages. In the present study, the heat- and mass-transfer processes in two heat-pump systems -- those based on absorption processes, and those using refrigerant mixtures -- are analyzed. The major technical barriers for achieving the ideal performance predicted by thermodynamic analysis are identified. The analysis provides general guidelines for the development of heat- and mass-transfer equipment for advanced heat-pump systems.

Panchal, C.B.; Bell, K.J.

1992-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" 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

Characterization of industrial process waste heat and input heat streams  

SciTech Connect (OSTI)

The nature and extent of industrial waste heat associated with the manufacturing sector of the US economy are identified. Industry energy information is reviewed and the energy content in waste heat streams emanating from 108 energy-intensive industrial processes is estimated. Generic types of process equipment are identified and the energy content in gaseous, liquid, and steam waste streams emanating from this equipment is evaluated. Matchups between the energy content of waste heat streams and candidate uses are identified. The resultant matrix identifies 256 source/sink (waste heat/candidate input heat) temperature combinations. (MHR)

Wilfert, G.L.; Huber, H.B.; Dodge, R.E.; Garrett-Price, B.A.; Fassbender, L.L.; Griffin, E.A.; Brown, D.R.; Moore, N.L.

1984-05-01T23:59:59.000Z

362

Experimental and Analytical Studies on Pyroelectric Waste Heat Energy Conversion  

E-Print Network [OSTI]

Waste heat Pyroelectric energy3 Pyroelectric Waste Heat Energy Harvesting Using Heat4 Pyroelectric Waste Heat Energy Harvesting Using Relaxor

Lee, Felix

2012-01-01T23:59:59.000Z

363

Energy 101: Geothermal Heat Pumps  

SciTech Connect (OSTI)

An energy-efficient heating and cooling alternative, the geothermal heat pump system moves heat from the ground to a building (or from a building to the ground) through a series of flexible pipe "loops" containing water. This edition of Energy 101 explores the benefits Geothermal and the science behind how it all comes together.

None

2011-01-01T23:59:59.000Z

364

Heat Pump Strategies and Payoffs  

E-Print Network [OSTI]

After evaluating numerous waste heat sources and heat pump designs for energy recovery, we have become aware that a great deal of confusion exists about the economics of heat pumps. The purpose of this article is to present some simple formulas...

Gilbert, J. S.

1982-01-01T23:59:59.000Z

365

Industrial Heat Pump Case Study  

E-Print Network [OSTI]

with operating the evaporator. The open-cycle heat pump design uses an electrically driven centrifugal compressor to recover the latent heat of the water vapor generated by the evaporator. (Steam was the original heat source but is now only needed for start...

Wagner, J. R.; Brush, F. C.

366

Spring 2014 Heat Transfer -1  

E-Print Network [OSTI]

Spring 2014 1 Heat Transfer - 1 Consider a cylindrical nuclear fuel rod of length L and diameter df and the tube at a rate m , and the outer surface of the tube is well insulated. Heat generation occurs within. The specific heat of water pc , and the thermal conductivity of the fuel rod fk are constants. The system

Virginia Tech

367

5. Heat transfer Ron Zevenhoven  

E-Print Network [OSTI]

1/120 5. Heat transfer Ron Zevenhoven �bo Akademi University Thermal and Flow Engineering / Värme Three heat transfer mechanisms Conduction Convection Radiation 2/120 Pic: B�88 �bo Akademi University | Thermal and Flow Engineering | 20500 Turku | Finland #12;3/120 5.1 Conductive heat transfer �bo Akademi

Zevenhoven, Ron

368

Energy 101: Geothermal Heat Pumps  

ScienceCinema (OSTI)

An energy-efficient heating and cooling alternative, the geothermal heat pump system moves heat from the ground to a building (or from a building to the ground) through a series of flexible pipe "loops" containing water. This edition of Energy 101 explores the benefits Geothermal and the science behind how it all comes together.

None

2013-05-29T23:59:59.000Z

369

RIS-M-2260 HEAT GRADIENT INDUCED MIGRATION OF BRINE INCLUSIONS IN ROCK SALT  

E-Print Network [OSTI]

RISØ-M-2260 HEAT GRADIENT INDUCED MIGRATION OF BRINE INCLUSIONS IN ROCK SALT Mathematical treatment project. Abstract. A mathematical model for the brine migration in rock salt around an infinite line heat source is set up. The tempera- ture field around the time dependent heat source is calculated by use

370

Numerical simulation of the heat transfer in amorphous silicon nitride membrane-based microcalorimeters  

E-Print Network [OSTI]

Numerical simulation of the heat transfer in amorphous silicon nitride membrane July 2003 Numerical simulations of the two-dimensional 2D heat flow in a membrane-based microcalorimeter have been performed. The steady-state isotherms and time-dependent heat flow have been calculated

Hellman, Frances

371

A Cartesian grid embedded boundary method for the heat equation and Poissons equation in three dimensions  

E-Print Network [OSTI]

A Cartesian grid embedded boundary method for the heat equation and Poisson�s equation in three­85] and extends work of McCorquodale, Colella and Johansen [A Cartesian grid embedded boundary method for the heat and time for the heat equation. Cartesian grid methods for elliptic PDE have a long history beginning with the no

372

Research & Development Roadmap: Emerging Water Heating Technologies...  

Energy Savers [EERE]

Emerging Water Heating Technologies Research & Development Roadmap: Emerging Water Heating Technologies The Research and Development (R&D) Roadmap for Emerging Water Heating...

373

Heat Waves, Global Warming, and Mitigation  

E-Print Network [OSTI]

Heat Waves, Global Warming, and Mitigation Ann E. Carlson*2008]HEAT WAVES, GLOBAL WARMING, AND MITIGATION 175 stroke2001). 2008]HEAT WAVES, GLOBAL WARMING, AND MITIGATION 177

Carlson, Ann E.

2008-01-01T23:59:59.000Z

374

E-Print Network 3.0 - acoustic heating Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

with the cooler air. Since the timing in the acoustic cycle is such that maximum heat transfer corresponds... . Under such conditions, acoustic amplification is...

375

E-Print Network 3.0 - absorption heat Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

for prototype hardware. Proof of concept. 9 12;At the present time, absorption heat... and air conditioning equipment. Therefore, the lower performance potential for the...

376

Fourier analysis of conductive heat transfer for glazed roofing materials  

SciTech Connect (OSTI)

For low-rise buildings, roof is the most exposed surface to solar radiation. The main mode of heat transfer from outdoor via the roof is conduction. The rate of heat transfer and the thermal impact is dependent on the thermophysical properties of roofing materials. Thus, it is important to analyze the heat distribution for the various types of roofing materials. The objectives of this paper are to obtain the Fourier series for the conductive heat transfer for two types of glazed roofing materials, namely polycarbonate and polyfilled, and also to determine the relationship between the ambient temperature and the conductive heat transfer for these materials. Ambient and surface temperature data were collected from an empirical field investigation in the campus of Universiti Teknologi MARA Shah Alam. The roofing materials were installed on free-standing structures in natural ventilation. Since the temperature data are generally periodic, Fourier series and numerical harmonic analysis are applied. Based on the 24-point harmonic analysis, the eleventh order harmonics is found to generate an adequate Fourier series expansion for both glazed roofing materials. In addition, there exists a linear relationship between the ambient temperature and the conductive heat transfer for both glazed roofing materials. Based on the gradient of the graphs, lower heat transfer is indicated through polyfilled. Thus polyfilled would have a lower thermal impact compared to polycarbonate.

Roslan, Nurhana Lyana; Bahaman, Nurfaradila; Almanan, Raja Noorliyana Raja; Ismail, Razidah [Faculty of Computer and Mathematical Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Zakaria, Nor Zaini [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

2014-07-10T23:59:59.000Z

377

Local Heat Transfer for Finned-Tube Heat Exchangers using Oval Tubes  

SciTech Connect (OSTI)

This paper presents the results of an experimental study of forced convection heat transfer in a narrow rectangular duct fitted with either a circular tube or an elliptical tube in crossflow. The duct was designed to simulate a single passage in a fin-tube heat exchanger. Heat transfer measurements were obtained using a transient technique in which a heated airflow is suddenly introduced to the test section. High-resolution local fin-surface temperature distributions were obtained at several times after initiation of the transient using an imaging infrared camera. Corresponding local fin-surface heat transfer coefficient distributions were then calculated from a locally applied one-dimensional semi-infinite inverse heat conduction model. Heat transfer results were obtained over an airflow rate ranging from 1.56 x 10-3 to 15.6 x 10-3 kg/s. These flow rates correspond to a duct-height Reynolds number range of 630 – 6300 with a duct height of 1.106 cm and a duct width-toheight ratio, W/H, of 11.25. The test cylinder was sized such that the diameter-to-duct height ratio, D/H is 5. The elliptical tube had an aspect ratio of 3:1 and a/H equal to 4.33. Results presented in this paper reveal visual and quantitative details of local fin-surface heat transfer distributions in the vicinity of circular and oval tubes and their relationship to the complex horseshoe vortex system that forms in the flow stagnation region. Fin surface stagnation-region Nusselt numbers are shown to be proportional to the square-root of Reynolds number.

O'Brien, James Edward; Sohal, Manohar Singh

2000-08-01T23:59:59.000Z

378

Absorption-heat-pump system  

DOE Patents [OSTI]

An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

Grossman, G.; Perez-Blanco, H.

1983-06-16T23:59:59.000Z

379

Heat Pump Water Heater Technology: Experiences of Residential Consumers and Utilities  

SciTech Connect (OSTI)

This paper presents a case study of the residential heat pump water heater (HPWH) market. Its principal purpose is to evaluate the extent to which the HPWH will penetrate the residential market sector, given current market trends, producer and consumer attributes, and technical parameters. The report's secondary purpose is to gather background information leading to a generic framework for conducting market analyses of technologies. This framework can be used to compare readiness and to factor attributes of market demand back into product design. This study is a rapid prototype analysis rather than a detailed case analysis. For this reason, primary data collection was limited and reliance on secondary sources was extensive. Despite having met its technical goals and having been on the market for twenty years, the HPWH has had virtually no impact on contributing to the nation's water heating. In some cases, HPWH reliability and quality control are well below market expectations, and early units developed a reputation for unreliability, especially when measured against conventional water heaters. In addition to reliability problems, first costs of HPWH units can be three to five times higher than conventional units. Without a solid, well-managed business plan, most consumers will not be drawn to this product. This is unfortunate. Despite its higher first costs, efficiency of an HPWH is double that of a conventional water heater. The HPWH also offers an attractive payback period of two to five years, depending on hot water usage. On a strict life-cycle basis it supplies hot water very cost effectively. Water heating accounts for 17% of the nation's residential consumption of electricity (see chart at left)--water heating is second only to space heating in total residential energy use. Simple arithmetic suggests that this figure could be reduced to the extent HPWH technology displaces conventional water heating. In addition, the HPWH offers other benefits. Because it produces hot water by extracting heat from the air it tends to dehumidify and cool the room in which it is placed. Moreover, it tends to spread the water heating load across utility non-peak periods. Thus, electric utilities with peak load issues could justify internal programs to promote this technology to residential and commercial customers. For practical purposes, consumers are indifferent to the manner in which water is heated but are very interested in product attributes such as initial first cost, operating cost, performance, serviceability, product size, and installation costs. Thus, the principal drivers for penetrating markets are demonstrating reliability, leveraging the dehumidification attributes of the HPWH, and creating programs that embrace life-cycle cost principles. To supplement this, a product warranty with scrupulous quality control should be implemented; first-price reduction through engineering, perhaps by reducing level of energy efficiency, should be pursued; and niche markets should be courted. The first step toward market penetration is to address the HPWH's performance reliability. Next, the manufacturers could engage select utilities to aggressively market the HPWH. A good approach would be to target distinct segments of the market with the potential for the highest benefits from the technology. Communications media that address performance issues should be developed. When marketing to new home builders, the HPWH could be introduced as part of an energy-efficient package offered as a standard feature by builders of new homes within a community. Conducting focus groups across the United States to gather input on HPWH consumer values will feed useful data back to the manufacturers. ''Renaming'' and ''repackaging'' the HPWH to improve consumer perception, appliance aesthetics, and name recognition should be considered. Once an increased sales volume is achieved, the manufacturers should reinvest in R&D to lower the price of the units. The manufacturers should work with ''do-it-yourself'' (DIY) stores to facilitate introduction of th

Ashdown, BG

2004-08-04T23:59:59.000Z

380

Heating 7.2 user`s manual  

SciTech Connect (OSTI)

HEATING is a general-purpose conduction heat transfer program written in Fortran 77. HEATING can solve steady-state and/or transient heat conduction problems in one-, two-, or three-dimensional Cartesian, cylindrical, or spherical coordinates. A model may include multiple materials, and the thermal conductivity, density, and specific heat of each material may be both time- and temperature-dependent. The thermal conductivity may also be anisotropic. Materials may undergo change of phase. Thermal properties of materials may be input or may be extracted from a material properties library. Heat-generation rates may be dependent on time, temperature, and position, and boundary temperatures may be time- and position-dependent. The boundary conditions, which may be surface-to-environment or surface-to-surface, may be specified temperatures or any combination of prescribed heat flux, forced convection, natural convection, and radiation. The boundary condition parameters may be time- and/or temperature-dependent. General gray-body radiation problems may be modeled with user-defined factors for radiant exchange. The mesh spacing may be variable along each axis. HEATING uses a runtime memory allocation scheme to avoid having to recompile to match memory requirements for each specific problem. HEATING utilizes free-form input. Three steady-state solution techniques are available: point-successive-overrelaxation iterative method with extrapolation, direct-solution, and conjugate gradient. Transient problems may be solved using any one of several finite-difference schemes: Crank-Nicolson implicit, Classical Implicit Procedure (CIP), Classical Explicit Procedure (CEP), or Levy explicit method. The solution of the system of equations arising from the implicit techniques is accomplished by point-successive-overrelaxation iteration and includes procedures to estimate the optimum acceleration parameter.

Childs, K.W.

1993-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" 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

Heat Transfer in Complex Fluids  

SciTech Connect (OSTI)

Amongst the most important constitutive relations in Mechanics, when characterizing the behavior of complex materials, one can identify the stress tensor T, the heat flux vector q (related to heat conduction) and the radiant heating (related to the radiation term in the energy equation). Of course, the expression 'complex materials' is not new. In fact, at least since the publication of the paper by Rivlin & Ericksen (1955), who discussed fluids of complexity (Truesdell & Noll, 1992), to the recently published books (Deshpande et al., 2010), the term complex fluids refers in general to fluid-like materials whose response, namely the stress tensor, is 'non-linear' in some fashion. This non-linearity can manifest itself in variety of forms such as memory effects, yield stress, creep or relaxation, normal-stress differences, etc. The emphasis in this chapter, while focusing on the constitutive modeling of complex fluids, is on granular materials (such as coal) and non-linear fluids (such as coal-slurries). One of the main areas of interest in energy related processes, such as power plants, atomization, alternative fuels, etc., is the use of slurries, specifically coal-water or coal-oil slurries, as the primary fuel. Some studies indicate that the viscosity of coal-water mixtures depends not only on the volume fraction of solids, and the mean size and the size distribution of the coal, but also on the shear rate, since the slurry behaves as shear-rate dependent fluid. There are also studies which indicate that preheating the fuel results in better performance, and as a result of such heating, the viscosity changes. Constitutive modeling of these non-linear fluids, commonly referred to as non-Newtonian fluids, has received much attention. Most of the naturally occurring and synthetic fluids are non-linear fluids, for example, polymer melts, suspensions, blood, coal-water slurries, drilling fluids, mud, etc. It should be noted that sometimes these fluids show Newtonian (linear) behavior for a given range of parameters or geometries; there are many empirical or semi-empirical constitutive equations suggested for these fluids. There have also been many non-linear constitutive relations which have been derived based on the techniques of continuum mechanics. The non-linearities oftentimes appear due to higher gradient terms or time derivatives. When thermal and or chemical effects are also important, the (coupled) momentum and energy equations can give rise to a variety of interesting problems, such as instability, for example the phenomenon of double-diffusive convection in a fluid layer. In Conclusion, we have studied the flow of a compressible (density gradient type) non-linear fluid down an inclined plane, subject to radiation boundary condition. The heat transfer is also considered where a source term, similar to the Arrhenius type reaction, is included. The non-dimensional forms of the equations are solved numerically and the competing effects of conduction, dissipation, heat generation and radiation are discussed. It is observed that the velocity increases rapidly in the region near the inclined surface and is slower in the region near the free surface. Since R{sub 7} is a measure of the heat generation due to chemical reaction, when the reaction is frozen (R{sub 7}=0.0) the temperature distributions would depend only on R{sub 1}, and R{sub 2}, representing the effects of the pressure force developed in the material due to the distribution, R{sub 3} and R{sub 4} viscous dissipation, R{sub 5} the normal stress coefficient, R{sub 6} the measure of the emissivity of the particles to the thermal conductivity, etc. When the flow is not frozen (RP{sub 7} > 0) the temperature inside the flow domain is much higher than those at the inclined and free surfaces. As a result, heat is transferred away from the flow toward both the inclined surface and the free surface with a rate that increases as R{sub 7} increases. For a given temperature, an increase in {zeta} implies that the activation energy is smaller and thus, the reaction ra

Mehrdad Massoudi

2012-01-01T23:59:59.000Z

382

Combined Heat and Power: A Technology Whose Time Has Come  

E-Print Network [OSTI]

out of money. 74 Second, Section 1603 of ARRA replaced theby the ACEEE found that Section 1603’s upfront payment “by the amount of the Section 1603 payment. ” 76 By the end

Ferraina, Steven

2014-01-01T23:59:59.000Z

383

Combined Heat and Power: A Technology Whose Time Has Come  

E-Print Network [OSTI]

Williams, & Jonas Monast, Wind Power: Barriers and Policyheat, photovoltaics, wind power, biomass, and hydroelectrictechnology. 183 Including wind power in states’ Renewable

Ferraina, Steven

2014-01-01T23:59:59.000Z

384

Combined Heat and Power: A Technology Whose Time Has Come  

E-Print Network [OSTI]

NN . § 212.08(c) (West 2013); Renewable Energy in Florida, Agas emissions, use of renewable electric or thermal energyas-of-right” siting for renewable energy generation, and

Ferraina, Steven

2014-01-01T23:59:59.000Z

385

EMPIRICAL DETERMINATION OF THE HEAT CAPACITY, TIME CONSTANT, AND  

E-Print Network [OSTI]

://www.ecd.bnl.gov/steve #12;GLOBAL ENERGY BALANCE Global and annual average energy fluxes in watts per square meter Schwartz to informed decision making. #12;AEROSOL IN MEXICO CITY BASIN #12;AEROSOL IN MEXICO CITY BASIN Mexico City

Schwartz, Stephen E.

386

Combined Heat and Power: A Technology Whose Time Has Come  

E-Print Network [OSTI]

states in implementing the RGGI. 173 A similar organizationPress Release, supra note 45. 173. See RGGI, Inc. , R EG ’NITIATIVE , http://www.rggi.org/rggi (last visited Jan. 20,

Ferraina, Steven

2014-01-01T23:59:59.000Z

387

Gelling by Heating  

E-Print Network [OSTI]

We introduce a simple model, a binary mixture of patchy particles, which has been designed to form a gel upon heating. Due to the specific nature of the particle interactions, notably the number and geometry of the patches as well as their interaction energies, the system is a fluid both at high and at low temperatures, whereas at intermediate temperatures the system forms a solid-like disordered open network structure, i.e. a gel. Using molecular dynamics we investigate the static and dynamic properties of this system.

Sandalo Roldan-Vargas; Frank Smallenburg; Walter Kob; Francesco Sciortino

2013-03-11T23:59:59.000Z

388

Solar heated rotary kiln  

DOE Patents [OSTI]

A solar heated rotary kiln utilized for decomposition of materials, such as zinc sulfate. The rotary kiln has an open end and is enclosed in a sealed container having a window positioned for directing solar energy into the open end of the kiln. The material to be decomposed is directed through the container into the kiln by a feed tube. The container is also provided with an outlet for exhaust gases and an outlet for spent solids, and rests on a tiltable base. The window may be cooled and kept clear of debris by coolant gases.

Shell, Pamela K. (Tracy, CA)

1984-01-01T23:59:59.000Z

389

Residential heating oil price  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar HomePromisingStories »Submitter A B CAdministration (EIA)heating

390

Sandia National Laboratories: Heat Exchanger Development  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

LabHeat Exchanger Development Heat Exchanger Development Planned Heat Exchanger Test Loop Capabilities Heat Exchanger 1 500 kW Heaters (Elec.) 500 kW Gas Cooler Unbalanced flows...

391

Billet Heating with the Homopolar Generator  

E-Print Network [OSTI]

Forging billets are presently brought from room temperature to forging temperature using one of three heating methods - indirect heating in a furnace, either fuel-fired or electric; direct electric resistance heating; or induction heating. Homopolar...

Weldon, W. F.; Keith, R. E.; Weldon, J. M.

1980-01-01T23:59:59.000Z

392

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

E-Print Network [OSTI]

An irreversible cycle model of a heat pump operating between two variable-temperature heat reservoirs is established and used to analyze the performance of the heat pump affected by heat resistances, heat leakage and internal dissipation...

Huang, Y.; Sun, D.

2006-01-01T23:59:59.000Z

393

Development of a Heat Transfer Model for the Integrated Facade Heating  

E-Print Network [OSTI]

the heat transfer process of facade heating (mullion radiators) in a pilot research project in Pittsburgh, PA. The heat transfer model for facade heating is developed and verified by measured data. The comparison shows that the heat transfer model predicts...

Gong, X.; Archer, D. H.; Claridge, D. E.

2007-01-01T23:59:59.000Z

394

Metallurgy Department Progress Report for the Period  

E-Print Network [OSTI]

Dlcfc^ooWS imsm "-"' Metallurgy Department Progress Report for the Period 1 January to 31 December 1962 (Uw National Laboratory, DK-4000 Roskilde, Denmark July 1963 #12;Risø-R-486 METALLURGY DEPARTMENT PROGRESS REPORT FOR THE PERIOD 1 JANUARY TO 31 DECEMBER 1982 Abstract. The activities of the Metallurgy

395

Broadband solar absorption enhancement via periodic  

E-Print Network [OSTI]

Province, 230009, P. R. China. Solution processed colloidal quantum dot (CQD) solar cells have greatBroadband solar absorption enhancement via periodic nanostructuring of electrodes Michael M. Adachi demonstrate a bottom- illuminated periodic nanostructured CQD solar cell that enhances broadband absorption

396

Hydraulic Characteristics of the Lower Snake River during Periods of Juvenile Fall Chinook Salmon Migration, 2002-2006 Final Report.  

SciTech Connect (OSTI)

This report documents a four-year study to assess hydraulic conditions in the lower Snake River. The work was conducted for the Bonneville Power Administration, U.S. Department of Energy, by the Pacific Northwest National Laboratory. Cold water released from the Dworshak Reservoir hypolimnion during mid- to late-summer months cools the Clearwater River far below equilibrium temperature. The volume of released cold water augments the Clearwater River, and the combined total discharge is on the order of the Snake River discharge when the two rivers meet at their confluence near the upstream edge of Lower Granite Reservoir. With typical temperature differences between the Clearwater and Snake rivers of 10 C or more during July and August, the density difference between the two rivers during summer flow augmentation periods is sufficient to stratify Lower Granite Reservoir as well as the other three reservoirs downstream. Because cooling of the river is desirable for migrating juvenile fall Chinook salmon (Oncorhynchus tshawytscha) during this same time period, the amount of mixing and cold water entrained into Lower Granite Reservoir's epilimnion at the Clearwater/Snake River confluence is of key biological importance. Data collected during this project indicates the three reservoirs downstream of Lower Granite also stratify as direct result of flow augmentation from Dworshak Reservoir. These four reservoirs are also heavily influenced by wind forcing at the water's surface and during periods of low river discharge often behave like a two-layer lake. During these periods of stratification, lower river discharge, and wind forcing, the water in the upper layer of the reservoir is held in place or moves slightly upstream. This upper layer is also exposed to surface heating and may warm up to temperatures close to equilibrium temperature. The thickness (depth) of this upper warm layer and its direction of travel may be of key biological importance to juvenile fall Chinook salmon. This report describes field data collection, modeling, and analysis of hydrodynamic and temperature conditions in the Lower Granite Reservoir during the summer flow augmentation periods of 2002, 2003, and 2004. Although temperature, and hence density, differences during flow augmentation periods between the Clearwater and Snake rivers were approximately equal (7-12 C) for all four years, the discharge ratio varied which resulted in significant differences in entrainment of cooler Clearwater River water into the Lower Granite Reservoir epilimnion. However, as a direct result of system management, Lower Granite Dam tailrace temperatures were maintained near 20 C during all years. Primary differences in the other three lower Snake River reservoirs were therefore a result of meteorological conditions and dam operations, which produced variations in wind setup and surface heating. Circulation patterns in all four lower Snake River reservoirs were numerically simulated for periods of 2002, 2003, 2004, and 2005 using CE-QUAL-W2. Simulation results show that these models are capable of matching diurnal and long-term temperature and velocity changes in the reservoirs. In addition, the confluence zone of the Clearwater and Snake rivers was modeled using the three-dimensional non-hydrostatic model Flow3D. Once calibrated and validated, the reservoir models were used to investigate downstream impacts of alternative reservoir operation schemes, such as increasing or decreasing the ratio of Clearwater to Snake river discharge. Simulation results were linked with the particle tracking model FINS to develop reservoir-integrated metrics that varied due to these alternative operation schemes. Findings indicate that significant alterations in water temperature throughout the lower Snake River are possible by altering hypolimnetic discharges from Dworshak Reservoir, which may also impact the behavior of migrating juvenile fall Chinook salmon during periods of flow augmentation.

Cook, C.; Dibrani, B.; Richmond, M.; Bleich, M.; Titzler, P..; Fu, T. [Pacific Northwest National Laboratory

2006-01-01T23:59:59.000Z

397

Thermal characterization of submicron polyacrylonitrile fibers based on optical heating and electrical thermal sensing  

SciTech Connect (OSTI)

In this work, the thermal diffusivity of single submicron ({approx}800 nm) polyacrylonitrile (PAN) fibers is characterized using the recently developed optical heating and electrical thermal sensing technique. In the experiment, a thin Au film (approximately in the nanometer range) is coated on the surface of nonconductive PAN fibers. A periodically modulated laser beam is used to irradiate suspended individual fibers to achieve noncontact periodical heating. The periodical temperature response of the sample is monitored by measuring the electrical resistance variation of the thin Au coating. The experimental results for three different synthesized PAN fibers with varying Au coating thickness are presented and discussed.

Hou Jinbo; Wang Xinwei; Zhang Lijun [Department of Mechanical Engineering, N104 Walter Scott Engineering Center, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0656 (United States)

2006-10-09T23:59:59.000Z

398

FINITE ELEMENT SIMULATION OF MACROSCOPIC MACHINING PROCESSES -IMPLEMENTATION OF TIME  

E-Print Network [OSTI]

force and heat flux prediction is triggered that calculates the mechanical and thermal load. It is modeled mathematically by linking heat con- duction equation with the deformation equation on a time with a process model for prediction of cutting forces and heat flux, thermal and mechanical effects during

Schmidt, Alfred

399

Skutterudite Thermoelectric Generator For Automotive Waste Heat...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Skutterudite Thermoelectric Generator For Automotive Waste Heat Recovery Skutterudite Thermoelectric Generator For Automotive Waste Heat Recovery Skutterudite TE modules were...

400

Distributed Generation with Heat Recovery and Storage  

E-Print Network [OSTI]

Energy; Grid systems; Optimization; Heat flow; Financialof grid power and by utilizing combined heat and power (CHP)

Siddiqui, Afzal S.; Marnay, Chris; Firestone, Ryan M.; Zhou, Nan

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" 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

Waste Heat Recovery Opportunities for Thermoelectric Generators...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Waste Heat Recovery Opportunities for Thermoelectric Generators Waste Heat Recovery Opportunities for Thermoelectric Generators Thermoelectrics have unique advantages for...

402

North Village Ground Source Heat Pumps  

Broader source: Energy.gov [DOE]

Overview: Installation of Ground Source Heat Pumps. Replacement of Aging Heat Pumps. Alignment with Furmans Sustainability Goals.

403

Energy 101: Geothermal Heat Pumps | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Geothermal Heat Pumps Energy 101: Geothermal Heat Pumps Addthis Description An energy-efficient heating and cooling alternative, the geothermal heat pump system moves heat from the...

404

apparent molar heat: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Websites Summary: efficient use of renewable energy in district heating individual heat pumps solar heating and wood pellets individual heat pumps, solar heating and...

405

Light weight and economical exhaust heat exchanger for waste...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

exhaust heat exchanger for waste heat recovery using mixed radiant and convective heat transfer Light weight and economical exhaust heat exchanger for waste heat recovery...

406

Superradiant Quantum Heat Engine  

E-Print Network [OSTI]

Quantum physics has revolutionized the classical disciplines of mechanics, statistical physics, and electrodynamics. It modernized our society with many advances such as lasers and transistors. One branch of scientific knowledge however seems untouched: thermodynamics. Major motivation behind thermodynamics is to develop efficient heat engines. Technology has a trend to miniaturize engines, reaching to the quantum regimes. Inevitably, development of quantum heat engines (QHEs) requires investigations of thermodynamical principles from quantum mechanical perspective, and motivates the emerging field of quantum thermodynamics. Studies of QHEs debate on whether quantum coherence can be used as a resource. We explore an alternative that quantum coherence can be a catalyst. We propose a QHE which consists of a photon gas inside an optical cavity as the working fluid and quantum coherent atomic clusters as the fuel. Utilizing the superradiance, where a cluster can radiate quadratically faster than a single atom, we show that the work capability of the QHE becomes proportional to the square of the number of the atoms. In addition to practical value of cranking up a QHE, our results reveal a fundamental difference of a quantum fuel from its classical counterpart.

Ali Ü. C. Hardal; Özgür E. Müstecapl?oglu

2015-03-12T23:59:59.000Z

407

Quantum Heat Bath  

E-Print Network [OSTI]

A model for a quantum heat bath is introduced. When the bath molecules have finitely many degrees of freedom, it is shown that the assumption that the molecules are weakly interacting is sufficient to enable one to derive the canonical distribution for the energy of a small system immersed in the bath. While the specific form of the bath temperature, for which we provide an explicit formula, depends on (i) spectral properties of the bath molecules, and (ii) the choice of probability measure on the state space of the bath, we are in all cases able to establish the existence of a strictly positive lower bound on the temperature of the bath. The results can be used to test the merits of different hypotheses for the equilibrium states of quantum systems. Two examples of physically plausible choices for the probability measure on the state space of a quantum heat bath are considered in detail, and the associated lower bounds on the temperature of the bath are worked out.

Dorje C. Brody; Lane P. Hughston

2014-11-17T23:59:59.000Z

408

Geothermal direct-heat utilization assistance. Quarterly project progress report, October--December 1993  

SciTech Connect (OSTI)

This report consists of brief summaries of the activities of the Geo-Heat Center during the report period. Technical assistance was given to requests from 20 states in the following applications: space and district heating; geothermal heat pumps; greenhouses; aquaculture; industrial plants; electric power; resource/well; equipment; and resort/spa. Research and development activities progressed on (1) compilation of data on low-temperature resources and (2) evaluation of groundwater vs. ground-coupled heat pumps. Also summarized are technology transfer activities and geothermal progress monitoring activities.

Not Available

1993-12-31T23:59:59.000Z

409

Geothermal direct-heat utilization assistance. Quarterly report, October--December 1996  

SciTech Connect (OSTI)

This report summarizes geothermal technical assistance, R&D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the first quarter of FY-97. It describes 174 contracts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, equipment, economics and resources. Research activities are summarized on greenhouse peaking. Outreach activities include the publication of a geothermal direct use Bulletin, dissemination of information, geothermal library, technical papers and seminars, and progress monitor reports on geothermal resources and utilization.

NONE

1996-12-31T23:59:59.000Z

410

District heating feasibility, Industrial Corridor, Jamestown, New York  

SciTech Connect (OSTI)

The Industrial Corridor of Jamestown, New York, contains more than twenty industrial/manufacturing companies, whose thermal demands, in addition to space heating, include significant process heating loads. This study investigated in depth, the technical and economic feasibility of implementing a district heating system in the Industrial Corridor which can serve both process and space heating loads. Based upon the heat load assessment conducted, the study focused upon nine companies with the largest thermal demand. Alternative system implementation designs were considered including new conventional centralized boiler plants, gas turbine cogeneration, and both high temperature hot water and steam as the heat transport media in an underground distribution system. The study concluded that, in view of the nature of existing prospective customer loads being primarily steam based, the most economical system for near term phased development is a steam based system with a new conventional centrally located steam boiler plant. The economic potential for a cogeneration system was found to be sensitive to electricity buy back rates, which at present, are not attractive. Implementing a modern high temperature hot water system would require significant customer retrofit costs to convert their steam based systems to hot water, resulting in long and unattractive pay back periods. Unless customer hot water retrofit costs can be expended without penalty to the district system economics, hot water district heating is not considered economically feasible. Chapters describe heat load assessment; heat source analysis; system implementation; transmission and distribution systems assessment; institutional assessment; system economic analysis; and customer retrofit, economic analysis, and conclusions 20 figs., 22 tabs.

Not Available

1988-06-01T23:59:59.000Z

411

Reduction in the intensity of solar X-ray emission in the 2- to 15-keV photon energy range and heating of the solar corona  

SciTech Connect (OSTI)

The time profiles of the energy spectra of low-intensity flares and the structure of the thermal background of the soft X-ray component of solar corona emission over the period of January-February, 2003, are investigated using the data of the RHESSI project. A reduction in the intensity of X-ray emission of the solar flares and the corona thermal background in the 2- to 15-keV photon energy range is revealed. The RHESSI data are compared with the data from the Interball-Geotail project. A new mechanism of solar corona heating is proposed on the basis of the results obtained.

Mirzoeva, I. K., E-mail: colombo2006@mail.ru [Russian Academy of Sciences, Space Research Institute (Russian Federation)

2013-04-15T23:59:59.000Z

412

Heat extraction from salinity-gradient solar ponds using heat pipe heat exchangers  

SciTech Connect (OSTI)

This paper presents the results of experimental and theoretical analysis on the heat extraction process from solar pond by using the heat pipe heat exchanger. In order to conduct research work, a small scale experimental solar pond with an area of 7.0 m{sup 2} and a depth of 1.5 m was built at Khon Kaen in North-Eastern Thailand (16 27'N102 E). Heat was successfully extracted from the lower convective zone (LCZ) of the solar pond by using a heat pipe heat exchanger made from 60 copper tubes with 21 mm inside diameter and 22 mm outside diameter. The length of the evaporator and condenser section was 800 mm and 200 mm respectively. R134a was used as the heat transfer fluid in the experiment. The theoretical model was formulated for the solar pond heat extraction on the basis of the energy conservation equations and by using the solar radiation data for the above location. Numerical methods were used to solve the modeling equations. In the analysis, the performance of heat exchanger is investigated by varying the velocity of inlet air used to extract heat from the condenser end of the heat pipe heat exchanger (HPHE). Air velocity was found to have a significant influence on the effectiveness of heat pipe heat exchanger. In the present investigation, there was an increase in effectiveness by 43% as the air velocity was decreased from 5 m/s to 1 m/s. The results obtained from the theoretical model showed good agreement with the experimental data. (author)

Tundee, Sura; Terdtoon, Pradit; Sakulchangsatjatai, Phrut [Department of Mechanical Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200 (Thailand); Singh, Randeep; Akbarzadeh, Aliakbar [Energy Conservation and Renewable Energy Group, School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Bundoora East Campus, Bundoora, Victoria 3083 (Australia)

2010-09-15T23:59:59.000Z

413

The ECA indirectly heated Stirling engine  

SciTech Connect (OSTI)

At the beginning of the 1980s the ECA Company designed and manufactured the first French Stirling engine, partially funded by the French government. The ECA engine has several design features of special interest: indirect heating by sodium heat pipes, cylinder block with four double-acting cylinders in line with a single crankshaft, four identical and demountable heat exchanger modules, piston rod seals with recuperation of leakage losses by means of four integrated rod pumps and with hermetic gas and oil seals using four roll socks, and power control by means of three gas valves and a 3.5-MPa helium bottle. The ECA engine ran for the first time and at the first attempt at the end of June 1982 and rapidly delivered a power of 5 kW at reduced pressure. Further testing of this 4-by 113-cm3 engine is under way to obtain a nominal power of 12 kW and an efficiency of 36% (heat to shaft power) with a very simplified design.

Carlqvist, S.G.; Darche, M.; Ducroux, P.

1983-08-01T23:59:59.000Z

414

Relating magnetic reconnection to coronal heating  

E-Print Network [OSTI]

It is clear that the solar corona is begin heated and that coronal magnetic fields undergo reconnection all the time. Here we attempt to show that these two facts are in fact related - i.e. coronal reconnection generates heat. This attempt must address the fact that topological change of field lines does not automatically generate heat. We present one case of flux emergence where we have measured the rate of coronal magnetic reconnection and the rate of energy dissipation in the corona. The ratio of these two, $P/\\dot{\\Phi}$, is a current comparable to the amount of current expected to flow along the boundary separating the emerged flux from the pre-existing flux overlying it. We can generalize this relation to the overall corona in quiet Sun or in active regions. Doing so yields estimates for the contribution to corona heating from magnetic reconnection. These estimated rates are comparable to the amount required to maintain the corona at its observed temperature.

Longcope, Dana W

2015-01-01T23:59:59.000Z

415

Heat Pump Markets UK in Europe  

E-Print Network [OSTI]

Heat Pump Markets UK in Europe IEA Heat Pump Workshop 13. November 2012 Zoltan Karpathy #12;2 Excellence in Market Intelligence Agenda About BSRIA WMI UK in the European Heat Pump Market Heating BSRIA WMI UK in the European Heat Pump Market Heating Technologies in New and Existing Buildings Hybrid

Oak Ridge National Laboratory

416

Heat pump having improved defrost system  

DOE Patents [OSTI]

A heat pump system includes, in an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant: a compressor; an interior heat exchanger; an exterior heat exchanger; an accumulator; and means for heating the accumulator in order to defrost the exterior heat exchanger.

Chen, Fang C. (Knoxville, TN); Mei, Viung C. (Oak Ridge, TN); Murphy, Richard W. (Knoxville, TN)

1998-01-01T23:59:59.000Z

417

Heat pump having improved defrost system  

DOE Patents [OSTI]

A heat pump system includes, in an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant: a compressor; an interior heat exchanger; an exterior heat exchanger; an accumulator; and means for heating the accumulator in order to defrost the exterior heat exchanger. 2 figs.

Chen, F.C.; Mei, V.C.; Murphy, R.W.

1998-12-08T23:59:59.000Z

418

Heat Generation by Heat Pump for LNG Plants.  

E-Print Network [OSTI]

?? Abstract The LNG production plant processing natural gas from the Snøhvit field outside Hammerfest in northern Norway utilizes heat and power produced locally with… (more)

Moe, Bjørn Kristian

2011-01-01T23:59:59.000Z

419

Simulation of hydration/dehydration of CaO/Ca(OH){sub 2} chemical heat pump reactor for cold/hot heat generation  

SciTech Connect (OSTI)

A chemical heat pump (CHP) utilizes reversible reactions involving significant endothermic and exothermic heats of reaction in order to develop a heat pump effect by storing and releasing energy while transforming it from chemical to thermal energy and vice versa. In this paper, the authors present a mathematical model and its numerical solution for the heat and mass transport phenomena occurring in the reactant particle bed of the CHP for heat storage and cold/hot heat generation based on the CaO/Ca(OH){sub 2} reversible hydration/dehydration reaction. Transient conservation equations of mass and energy transport including chemical kinetics are solved numerically subject to appropriate boundary and initial conditions to examine the influence of the mass transfer resistance on the overall performance of this CHP configuration. These results are presented and discussed with the aim of enhancing the CHP performance in the next generation reactor designs. The CHP can store thermal energy in industrial waste heat, solar heat, terrestrial heat, etc. in the form of chemical energy, and release it at various temperature levels during the heat-demand period.

Ogura, Hironao; Shimojyo, Rui; Kage, Hiroyuki; Matsuno, Yoshizo; Mujumdar, A.S.

1999-09-01T23:59:59.000Z

420

Case Studies of Waste Heat Driven Industrial Heat Pumps from the North Carolina State University Industrial Assessment Center.  

E-Print Network [OSTI]

??Waste heat driven heat pumps can produce useful heat streams for manufacturing facilities. A heat pump system that uses a waste heat stream as the… (more)

Lewis, Nathaniel Bates

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" 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

Heat pump with freeze-up prevention  

DOE Patents [OSTI]

What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid prevents freeze up of the second heat exchanger by keeping the temperature above the dew point; and, optionally, provides heat for efficient operation.

Ecker, Amir L. (Dallas, TX)

1981-01-01T23:59:59.000Z

422

PREDICTING THE TIME RESPONSE OF A BUILDING UNDER HEAT INPUT CONDITIONS FOR ACTIVE SOLAR HEATING SYSTEMS  

E-Print Network [OSTI]

approximately equivalent to the air film resistance of theresistances R and R2 in parallel The thermal masses in the space are estimated: c 1 , the thermal equivalent

Warren, Mashuri L.

2013-01-01T23:59:59.000Z

423

Spring 2014 Heat Transfer -2  

E-Print Network [OSTI]

Spring 2014 Heat Transfer - 2 A thin electronic chip is in the shape of a square wafer, b = 1 cm surface of the chip with a heat transfer coefficient of h = 100 W/m2 -K. Assume the chip has a uniform per side with a mass of m = 0.3 grams and specific heat of C = 103 J/kg-K. The chip is mounted

Virginia Tech

424

Enhanced heat transfer using nanofluids  

DOE Patents [OSTI]

This invention is directed to a method of and apparatus for enhancing heat transfer in fluids such as deionized water. ethylene glycol, or oil by dispersing nanocrystalline particles of substances such as copper, copper oxide, aluminum oxide, or the like in the fluids. Nanocrystalline particles are produced and dispersed in the fluid by heating the substance to be dispersed in a vacuum while passing a thin film of the fluid near the heated substance. The fluid is cooled to control its vapor pressure.

Choi, Stephen U. S. (Lisle, IL); Eastman, Jeffrey A. (Naperville, IL)

2001-01-01T23:59:59.000Z

425

Energy-efficient water heating  

SciTech Connect (OSTI)

This fact sheet describes how to reduce the amount of hot water used in faucets and showers, automatic dishwashers, and washing machines; how to increase water-heating system efficiency by lowering the water heater thermostat, installing a timer and heat traps, and insulating hot water pipes and the storage tank; and how to use off-peak power to heat water. A resource list for further information is included.

NONE

1995-01-01T23:59:59.000Z

426

Heat sinking for printed circuitry  

DOE Patents [OSTI]

A flat pak or other solid-state device mounted on a printed circuit board directly over a hole extends therethrough so that the bottom of the pak or device extends beyond the bottom of the circuit board. A heat sink disposed beneath the circuit board contacts the bottom of the pak or device and provides direct heat sinking thereto. Pressure may be applied to the top of the pak or device to assure good mechanical and thermal contact with the heat sink.

Wilson, S.K.; Richardson, G.; Pinkerton, A.L.

1984-09-11T23:59:59.000Z

427

Variable-Period Undulators For Synchrotron Radiation  

DOE Patents [OSTI]

A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high-energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.

Shenoy, Gopal (Naperville, IL); Lewellen, John (Plainfield, IL); Shu, Deming (Darien, IL); Vinokurov, Nikolai (Novosibirsk, RU)

2005-02-22T23:59:59.000Z

428

Variable-Period Undulators for Synchrotron Radiation  

SciTech Connect (OSTI)

A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.

Shenoy, Gopal; Lewellen, John; Shu, Deming; Vinokurov, Nikolai

2005-02-22T23:59:59.000Z

429

Heat capacity of liquids: an approach from the solid phase  

E-Print Network [OSTI]

We calculate the energy and heat capacity of a liquid on the basis of its elastic properties and vibrational states. The experimental decrease of liquid heat capacity with temperature is attributed to the increasing loss of two transverse modes with frequency $\\omegaliquid relaxation time. In a simple model, liquid heat capacity is related to viscosity and is compared with the experimental data of mercury. We also calculate the vibrational energy of a quantum liquid, and show that transverse phonons can not be excited in the low-temperature limit. Finally, we discuss the implications of the proposed approach to liquids for the problem of glass transition.

Kostya Trachenko

2008-08-20T23:59:59.000Z

430

Cooling by heating  

E-Print Network [OSTI]

We introduce the idea of actually cooling quantum systems by means of incoherent thermal light, hence giving rise to a counter-intuitive mechanism of "cooling by heating". In this effect, the mere incoherent occupation of a quantum mechanical mode serves as a trigger to enhance the coupling between other modes. This notion of effectively rendering states more coherent by driving with incoherent thermal quantum noise is applied here to the opto-mechanical setting, where this effect occurs most naturally. We discuss two ways of describing this situation, one of them making use of stochastic sampling of Gaussian quantum states with respect to stationary classical stochastic processes. The potential of experimentally demonstrating this counter-intuitive effect in opto-mechanical systems with present technology is sketched.

A. Mari; J. Eisert

2011-04-01T23:59:59.000Z

431

Ceramic heat exchanger  

DOE Patents [OSTI]

A tube containment system is disclosed. The tube containment system does not significantly reduce heat transfer through the tube wall. The contained tube is internally pressurized, and is formed from a ceramic material having high strength, high thermal conductivity, and good thermal shock resistance. The tube containment system includes at least one ceramic fiber braid material disposed about the internally pressurized tube. The material is disposed about the tube in a predetermined axial spacing arrangement. The ceramic fiber braid is present in an amount sufficient to contain the tube if the tube becomes fractured. The tube containment system can also include a plurality of ceramic ring-shaped structures, in contact with the outer surface of the tube, and positioned between the tube and the ceramic fiber braid material, and/or at least one transducer positioned within tube for reducing the internal volume and, therefore, the energy of any shrapnel resulting from a tube fracture. 6 figs.

LaHaye, P.G.; Rahman, F.H.; Lebeau, T.P.; Severin, B.K.

1998-06-16T23:59:59.000Z

432

Ceramic heat exchanger  

DOE Patents [OSTI]

A tube containment system. The tube containment system does not significantly reduce heat transfer through the tube wall. The contained tube is internally pressurized, and is formed from a ceramic material having high strength, high thermal conductivity, and good thermal shock resistance. The tube containment system includes at least one ceramic fiber braid material disposed about the internally pressurized tube. The material is disposed about the tube in a predetermined axial spacing arrangement. The ceramic fiber braid is present in an amount sufficient to contain the tube if the tube becomes fractured. The tube containment system can also include a plurality of ceramic ring-shaped structures, in contact with the outer surface of the tube, and positioned between the tube and the ceramic fiber braid material, and/or at least one transducer positioned within tube for reducing the internal volume and, therefore, the energy of any shrapnel resulting from a tube fracture.

LaHaye, Paul G. (Kennebunk, ME); Rahman, Faress H. (Portland, ME); Lebeau, Thomas P. E. (Portland, ME); Severin, Barbara K. (Biddeford, ME)

1998-01-01T23:59:59.000Z

433

Holographic Heat Engines  

E-Print Network [OSTI]

It is shown that in theories of gravity where the cosmological constant is considered a thermodynamic variable, it is natural to use black holes as heat engines. Two examples are presented in detail using AdS charged black holes as the working substance. We notice that for static black holes, the maximally efficient traditional Carnot engine is also a Stirling engine. The case of negative cosmological constant supplies a natural realization of these engines in terms of the field theory description of the fluids to which they are holographically dual. We first propose a precise picture of how the traditional thermodynamic dictionary of holography is extended when the cosmological constant is dynamical and then conjecture that the engine cycles can be performed by using renormalization group flow. We speculate about the existence of a natural dual field theory counterpart to the gravitational thermodynamic volume.

Clifford V. Johnson

2014-09-04T23:59:59.000Z

434

Observations of Transient Active Region Heating with Hinode  

E-Print Network [OSTI]

We present observations of transient active region heating events observed with the Extreme Ultraviolet Imaging Spectrometer (EIS) and X-ray Telescope (XRT) on Hinode. This initial investigation focuses on NOAA active region 10940 as observed by Hinode on February 1, 2007 between 12 and 19 UT. In these observations we find numerous examples of transient heating events within the active region. The high spatial resolution and broad temperature coverage of these instruments allows us to track the evolution of coronal plasma. The evolution of the emission observed with XRT and EIS during these events is generally consistent with loops that have been heated and are cooling. We have analyzed the most energetic heating event observed during this period, a small GOES B-class flare, in some detail and present some of the spectral signatures of the event, such as relative Doppler shifts at one of the loop footpoints and enhanced line widths during the rise phase of the event. While the analysis of these transient events has the potential to yield insights into the coronal heating mechanism, these observations do not rule out the possibility that there is a strong steady heating level in the active region. Detailed statistical analysis will be required to address this question definitively.

Harry P. Warren; Ignacio Ugarte-Urra; David H. Brooks; Jonathan W. Cirtain; David R. Williams; Hirohisa Harra

2007-11-02T23:59:59.000Z

435

Electro-osmotic infusion for joule heating soil remediation techniques  

DOE Patents [OSTI]

Electro-osmotic infusion of ground water or chemically tailored electrolyte is used to enhance, maintain, or recondition electrical conductivity for the joule heating remediation technique. Induced flows can be used to infuse electrolyte with enhanced ionic conductivity into the vicinity of the electrodes, maintain the local saturation of near-electrode regions and resaturate a partially dried out zone with groundwater. Electro-osmotic infusion can also tailor the conductivity throughout the target layer by infusing chemically modified and/or heated electrolyte to improve conductivity contrast of the interior. Periodic polarity reversals will prevent large pH changes at the electrodes. Electro-osmotic infusion can be used to condition the electrical conductivity of the soil, particularly low permeability soil, before and during the heating operation. Electro-osmotic infusion is carried out by locating one or more electrodes adjacent the heating electrodes and applying a dc potential between two or more electrodes. Depending on the polarities of the electrodes, the induced flow will be toward the heating electrodes or away from the heating electrodes. In addition, electrodes carrying a dc potential may be located throughout the target area to tailor the conductivity of the target area.

Carrigan, Charles R. (Tracy, CA); Nitao, John J. (Castro Valley, CA)

1999-01-01T23:59:59.000Z

436

Industrial Process Heating - Technology Assessment  

Office of Environmental Management (EM)

materials, especially for heating corrosive fluids 306 Strength and corrosion of metallic components for structural and sensor protection 307 Coatings to...

437

Cyclotron subharmonics resonant (CSR) heating  

SciTech Connect (OSTI)

The cyclotron subharmonics resonant (CSR) heating mechanism is studied using particle simulation codes with an emphasis on the relationship between CSR and the nonlinear Landua damping.

Abe, H.

1994-01-01T23:59:59.000Z

438

Accelerating Combined Heat & Power Deployment  

Broader source: Energy.gov (indexed) [DOE]

ACCELERATING COMBINED HEAT & POWER DEPLOYMENT An Industry Consultation by the United States Energy Association August 31, 2011 Cover Photograph: CHP Plant at the Mueller Energy...

439

CHP, Waste Heat & District Energy  

Broader source: Energy.gov (indexed) [DOE]

and Applications 25 Oct 11 Today's Electric Grid What is CHP * ASHRAE Handbook: "Combined heat and power (CHP). Simultaneous production of electrical or mechanical energy and...

440

High Heat Flux Components Program  

SciTech Connect (OSTI)

Purpose is the development of the technologies necessary to design, build and operate high heat flux components such as actively cooled limiters, divertor collector plates, R.F. antennas, mirror end cells, mirror halo collectors, direct convertor collectors, and neutral beam dumps. These components require an integrated design that considers the plasma-materials interaction (PMI) issues, heat removal problems and materials issues (including possible low Z coatings and claddings). As a general definition, high heat flux components see heat fluxes ranging from 1 to 100 MW/m/sup 2/. Suitable materials include copper and copper alloys.

Whitley, J.B.

1983-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" 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.


441

Heat distribution by natural convection  

SciTech Connect (OSTI)

Natural convection can provide adequate heat distribution in many situtations that arise in buildings. This is appropriate, for example, in passive solar buildings where some rooms tend to be more strongly solar heated than others or to reduce the number of heating units required in a building. Natural airflow and heat transport through doorways and other internal building apertures is predictable and can be accounted for in the design. The nature of natural convection is described, and a design chart is presented appropriate to a simple, single-doorway situation. Natural convective loops that can occur in buildings are described and a few design guidelines are presented.

Balcomb, J.D.

1985-01-01T23:59:59.000Z

442

Effect of heat treatment and heat-to-heat variations in the fatigue-crack growth response of Alloy 718  

SciTech Connect (OSTI)

The fatigue-crack growth behavior of seven heats of Alloy 718 was studied at five different test temperatures. These seven heats represented at least four different producers, four different product forms, two melt practices, and most of the heat were tested in two different heat-treated conditions. Heat-to-heat variations were noted; these were most obvious in material given the conventional heat-treatment. 8 figs., 5 tabs.

James, L.A.; Mills, W.J.

1980-04-01T23:59:59.000Z

443

Single-machine scheduling with periodic and exible periodic maintenance to minimize maximum tardiness  

E-Print Network [OSTI]

periods often appear in industry due to a machine breakdown (stochastic) or preventive maintenance of machine unavailability. However, in some cases (e.g. preventive maintenance), the maintenance of a machineSingle-machine scheduling with periodic and exible periodic maintenance to minimize maximum

Paris-Sud XI, Université de

444

Urban Sewage Delivery Heat Transfer System (2): Heat Transfer  

E-Print Network [OSTI]

The thimble delivery heat-transfer (TDHT) system is one of the primary modes to utilize the energy of urban sewage. Using the efficiency-number of transfer units method ( ), the heat-transfer efficiencies of the parallel-flow and reverse-flow TDTH...

Zhang, C.; Wu, R.; Li, X.; Li, G.; Zhuang, Z.; Sun, D.

2006-01-01T23:59:59.000Z

445

Heat Transfer Characteristics of a Generalized Divided Flow Heat Exchanger  

E-Print Network [OSTI]

The concept of a "Divided-flow" heat exchanger is generalized by locating the shell inlet (or outlet) nozzle off-center such that the two shell sub-streams are unequal and traverse unequal flow paths. The governing equations for heat transfer...

Singh, K. P.

1979-01-01T23:59:59.000Z

446

Design of Heat Exchanger for Heat Recovery in CHP Systems  

E-Print Network [OSTI]

The objective of this research is to review issues related to the design of heat recovery unit in Combined Heat and Power (CHP) systems. To meet specific needs of CHP systems, configurations can be altered to affect different factors of the design...

Kozman, T. A.; Kaur, B.; Lee, J.

447

Heat Plan DenmarkHeat Plan Denmark Anders Dyrelundy  

E-Print Network [OSTI]

the supply and the demand side · An eye-opener for the Danish politicians · Could be a model for otherHeat Plan DenmarkHeat Plan Denmark Anders Dyrelundy Market Manager for Energy and Climate Rambøll Möller · The first study in Denmark, really to integrate the energy and building sectors ­ to combine

448

Analytical homogenization method for periodic composite materials  

E-Print Network [OSTI]

We present an easy-to-implement technique for determining the effective properties of composite materials with periodic microstructures, as well as the field distributions in them. Our method is based on the transformation ...

Chen, Ying

449

Impact of Motor Failures on Payback Periods  

E-Print Network [OSTI]

This paper uses MotorMaster and Vaughen's Complete Price Guide to determine payback periods for different motor failure scenarios. Some scenarios considered are rewinds, reconditions, and replacement of bearings. Prices for these repairs...

Cheek, K. F.; Pillay, P.; Dudley, K. J.

450

PARS II Process Document – DOE Period Close  

Broader source: Energy.gov [DOE]

This document details the process adopted by the Office of Acquisition and Project Management to prepare APM DepSec Monthly Status Report, finalize DOE close period package, and perform reporting...

451

Bypass valve and coolant flow controls for optimum temperatures in waste heat recovery systems  

DOE Patents [OSTI]

Implementing an optimized waste heat recovery system includes calculating a temperature and a rate of change in temperature of a heat exchanger of a waste heat recovery system, and predicting a temperature and a rate of change in temperature of a material flowing through a channel of the waste heat recovery system. Upon determining the rate of change in the temperature of the material is predicted to be higher than the rate of change in the temperature of the heat exchanger, the optimized waste heat recovery system calculates a valve position and timing for the channel that is configurable for achieving a rate of material flow that is determined to produce and maintain a defined threshold temperature of the heat exchanger, and actuates the valve according to the calculated valve position and calculated timing.

Meisner, Gregory P

2013-10-08T23:59:59.000Z

452

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

453

Number 2 heating oil/propane program. Final report, 1991/92  

SciTech Connect (OSTI)

During the 1991--92 heating season, the Massachusetts Division of Energy Resources (DOER) participated in a joint data collection program between several state energy offices and the federal Department of Energy`s (DOE) Energy Information Administration (EIA). The purpose of the program was to collect and monitor retail and wholesale heating oil and propane prices and inventories from October, 1991 through March, 1992. This final report begins with an overview of the unique events which had an impact on the reporting period. Next, the report summarizes the results from the residential heating oil and propane price surveys conducted by DOER over the 1991--1992 heating season. The report also incorporates the wholesale heating oil and propane prices and inventories collected by the EIA and distributed to the states. Finally, the report outlines DOER`s use of the data and responses to the events which unfolded during the 1991--1992 heating season.

McBrien, J.

1992-06-01T23:59:59.000Z

454

Entropic Time  

SciTech Connect (OSTI)

The formulation of quantum mechanics within the framework of entropic dynamics includes several new elements. In this paper we concentrate on one of them: the implications for the theory of time. Entropic time is introduced as a book-keeping device to keep track of the accumulation of changes. One new feature is that, unlike other concepts of time appearing in the so-called fundamental laws of physics, entropic time incorporates a natural distinction between past and future.

Caticha, Ariel [Department of Physics, University at Albany-SUNY, Albany, NY 12222 (United States)

2011-03-14T23:59:59.000Z

455

Geothermal Direct-Heat Utilization Assistance - Final Report  

SciTech Connect (OSTI)

The Geo-Heat Center provided (1) direct-use technical assistance, (2) research, and (3) information dissemination on geothermal energy over an 8 1/2 year period. The center published a quarterly bulletin, developed a web site and maintained a technical library. Staff members made 145 oral presentations, published 170 technical papers, completed 28 applied research projects, and gave 108 tours of local geothermal installations to 500 persons.

J. W. Lund

1999-07-14T23:59:59.000Z

456

Passive solar heating and analysis  

SciTech Connect (OSTI)

Passive solar heating experience and analysis techniques are reviewed with emphasis on annual auxiliary heat requirement. The role of analysis in the design of passive solar buildings is discussed. Selected results for existing systems are presented for locations in Saudi Arabia and climatically similar locations in the US. Advanced systems in the research stage are described.

Jones, R.W.

1984-01-01T23:59:59.000Z

457

Heat treating of manufactured components  

DOE Patents [OSTI]

An apparatus for heat treating manufactured components using microwave energy and microwave susceptor material is disclosed. The system typically includes an insulating vessel placed within a microwave applicator chamber. A moderating material is positioned inside the insulating vessel so that a substantial portion of the exterior surface of each component for heat treating is in contact with the moderating material.

Ripley, Edward B. (Knoxville, TN)

2012-05-22T23:59:59.000Z

458

HEATING THE ATMOSPHERE ABOVE SUNSPOTS  

E-Print Network [OSTI]

become fragmented and twisted, and where they generate the necessary energy to heat the solar coronaHEATING THE ATMOSPHERE ABOVE SUNSPOTS David Alexander and Neal E. Hurlburt Lockheed Martin Solar, University of Cambridge, Cambridge, CB3 9EW, UK Abstract We present our results of a hybrid model of sunspots

Rucklidge, Alastair

459

Heat reclaiming method and apparatus  

DOE Patents [OSTI]

Method and apparatus to extract heat by transferring heat from hot compressed refrigerant to a coolant, such as water, without exceeding preselected temperatures in the coolant and avoiding boiling in a water system by removing the coolant from direct or indirect contact with the hot refrigerant.

Jardine, Douglas M. (Colorado Springs, CO)

1984-01-01T23:59:59.000Z

460

Periodic forcing of graphene as geometric ripples on its surface  

E-Print Network [OSTI]

We explore the possibility of using modulated high frequency periodic driving of mono-layer graphene to create effects of curved geometry. The low energy continuum limit of graphene is modeled using Dirac equation in (2+1) dimensions. We suggest that the modifications to the Dirac equation when written in a curved background space can also be induced by a suitable driving scheme. The time dependent system yields, in the approximate limit of high frequency pulsing, an effective time independent Hamiltonian that governs the time evolution, except for an initial and a final kick. We use a specific form of 4-phase pulsed forcing with suitably tuned choice of modulating operators to mimic the effects of weak metric perturbations and thereby effectively induce mild wrinkles on the surface. The strength of the perturbation is found to be directly related to omega^{-1} the time period of the driving field at the leading order. We apply the method to engineer some specific `nearly flat' metrics and we find that the imprint of curvilinear geometry modifies the band structure significantly. The emergence of band gap at the Dirac point is crucial in this regard. We suggest that this method shall be useful in studying the response of various properties of such materials to non-trivial geometry without requiring any actual physical deformations.

Tridev Mishra; Tapomoy Guha Sarkar; Jayendra N. Bandyopadhyay

2014-10-27T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" 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.


461

Critical heat flux test apparatus  

DOE Patents [OSTI]

An apparatus for testing, in situ, highly irradiated specimens at high temperature transients is provided. A specimen, which has a thermocouple device attached thereto, is manipulated into test position in a sealed quartz heating tube by a robot. An induction coil around a heating portion of the tube is powered by a radio frequency generator to heat the specimen. Sensors are connected to monitor the temperatures of the specimen and the induction coil. A quench chamber is located below the heating portion to permit rapid cooling of the specimen which is moved into this quench chamber once it is heated to a critical temperature. A vacuum pump is connected to the apparatus to collect any released fission gases which are analyzed at a remote location.

Welsh, Robert E. (West Mifflin, PA); Doman, Marvin J. (McKeesport, PA); Wilson, Edward C. (West Mifflin, PA)

1992-01-01T23:59:59.000Z

462

High Temperature Heat Exchanger Project  

SciTech Connect (OSTI)

The UNLV Research Foundation assembled a research consortium for high temperature heat exchanger design and materials compatibility and performance comprised of university and private industry partners under the auspices of the US DOE-NE Nuclear Hydrogen Initiative in October 2003. The objectives of the consortium were to conduct investigations of candidate materials for high temperature heat exchanger componets in hydrogen production processes and design and perform prototypical testing of heat exchangers. The initial research of the consortium focused on the intermediate heat exchanger (located between the nuclear reactor and hydrogen production plan) and the components for the hydrogen iodine decomposition process and sulfuric acid decomposition process. These heat exchanger components were deemed the most challenging from a materials performance and compatibility perspective

Anthony E. Hechanova, Ph.D.

2008-09-30T23:59:59.000Z

463

Quantum Optomechanical Heat Engine  

E-Print Network [OSTI]

We investigate theoretically a quantum optomechanical realization of a heat engine. In a generic optomechanical arrangement the optomechanical coupling between the cavity field and the oscillating end-mirror results in polariton normal mode excitations whose character depends on the pump detuning and the coupling strength. By varying that detuning it is possible to transform their character from phonon-like to photon-like, so that they are predominantly coupled to the thermal reservoir of phonons or photons, respectively. We exploit the fact that the effective temperatures of these two reservoirs are different to produce a Otto cycle along one of the polariton branches. We discuss the basic properties of the system in two different regimes: in the optical domain it is possible to extract work from the thermal energy of a mechanical resonator at finite temperature, while in the microwave range one can in principle exploit the cycle to extract work from the blackbody radiation background coupled to an ultra-cold atomic ensemble.

Keye Zhang; Francesco Bariani; Pierre Meystre

2014-04-17T23:59:59.000Z

464

Solar heat collector  

SciTech Connect (OSTI)

An evacuated double-tubing solar heat collector is described comprising: an inner tube having an open end and a closed end; a selective absorption film applied over an exterior surface of the inner tube; an outer tube having an open end and a closed end; the inner tube being constructed to be received within the outer tube; and a substantially continuous annular coil spring ring being substantially found in cross section and of a predetermined thickness. The coil spring ring is disposed between and engages an interior surface of the outer tube and the exterior surface of the inner tube for spacing and resiliently supporting the inner tube relative to the outer tube. The ring is freely rotatably positioned to be moved axially along the length of the inner tube due only to frictional forces exerted on the coil spring. The coil spring ring is positioned on the inner tube at approximately a middle position along the length of the inner tube by being initially positioned on the inner tube adjacent to the closed end thereof and rotated upon itself axially along the inner tube only by frictional engagement with the interior surface of the outer tube as the inner tube is inserted into the open end of the outer tube and moved to a fully inserted position within the outer tube. The open end of the inner tube and the open end of the outer tube are fused to form a junction and hermetically sealed.

Takeuchi, H.; Mikiya, T.

1987-03-17T23:59:59.000Z

465

Modular heat exchanger  

DOE Patents [OSTI]

A shell and tube heat exchanger having a plurality of individually removable tube bundle modules. A lattice of structural steel forming rectangular openings therein is placed at each end of a cylindrical shell. Longitudinal structural members are placed in the shell between corners of the rectangular openings situated on opposite ends of the shell. Intermediate support members interconnect the longitudinal supports so as to increase the longitudinal supports rigidity. Rectangular parallelpiped tube bundle moldules occupy the space defined by the longitudinal supports and end supports and each include a rectangular tube sheet situated on each end of a plurality of tubes extending therethrough, a plurality of rectangular tube supports located between the tube sheets, and a tube bundle module stiffening structure disposed about the bundle's periphery and being attached to the tube sheets and tube supports. The corners of each tube bundle module have longitudinal framework members which are mateable with and supported by the longitudinal support members. Intermediate support members constitute several lattice, each of which is situate d in a plane between the end support members. The intermediate support members constituting the several lattice extend horizontally and vertically between longitudinal supports of adjacent tube module voids. An alternative embodiment for intermediate support members constitute a series of structural plates situated at the corners of the module voids and having recesses therein for receiving the respective longitudinal support members adjacent thereto, protrusions separating the recesses, and a plurality of struts situated between protrusions of adjacent structural plates.

Giardina, Angelo R. [Marple Township, Delaware County, PA

1981-03-03T23:59:59.000Z

466

LOW COST HEAT PUMP WATER HEATER (HPWH)  

SciTech Connect (OSTI)

Water heating accounts for the second largest portion of residential building energy consumption, after space conditioning. Existing HPWH products are a technical success, with demonstrated energy savings of 50% or more compared with standard electric resistance water heaters. However, current HPWHs available on the market cost an average of $1000 or more, which is too expensive for significant market penetration. What is needed is a method to reduce the first cost of HPWHs, so that the payback period will be reduced from 8 years to a period short enough for the market to accept this technology. A second problem with most existing HPWH products is the reliability issue associated with the pump and water loop needed to circulate cool water from the storage tank to the HPWH condenser. Existing integral HPWHs have the condenser wrapped around the water tank and thus avoid the pump and circulation issues but require a relatively complex and expensive manufacturing process. A more straightforward potentially less costly approach to the integral, single package HPWH design is to insert the condenser directly into the storage tank, or immersed direct heat exchanger (IDX). Initial development of an IDX HPWH met technical performance goals, achieving measured efficiencies or energy factors (EF) in excess of 1.79. In comparison conventional electric water heaters (EWH) have EFs of about 0.9. However, the initial approach required a 2.5" hole on top of the tank for insertion of the condenser - much larger than the standard openings typically provided. Interactions with water heater manufacturers indicated that the non standard hole size would likely lead to increased manufacturing costs (at least initially) and largely eliminate any cost advantage of the IDX approach. Recently we have been evaluating an approach to allow use of a standard tank hole size for insertion of the IDX condenser. Laboratory tests of a prototype have yielded an EF of 2.02.

Mei, Vince C [ORNL; Baxter, Van D [ORNL

2006-01-01T23:59:59.000Z

467

Periodic subsystem density-functional theory  

SciTech Connect (OSTI)

By partitioning the electron density into subsystem contributions, the Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) has recently emerged as a powerful tool for reducing the computational scaling of Kohn–Sham DFT. To date, however, FDE has been employed to molecular systems only. Periodic systems, such as metals, semiconductors, and other crystalline solids have been outside the applicability of FDE, mostly because of the lack of a periodic FDE implementation. To fill this gap, in this work we aim at extending FDE to treat subsystems of molecular and periodic character. This goal is achieved by a dual approach. On one side, the development of a theoretical framework for periodic subsystem DFT. On the other, the realization of the method into a parallel computer code. We find that periodic FDE is capable of reproducing total electron densities and (to a lesser extent) also interaction energies of molecular systems weakly interacting with metallic surfaces. In the pilot calculations considered, we find that FDE fails in those cases where there is appreciable density overlap between the subsystems. Conversely, we find FDE to be in semiquantitative agreement with Kohn–Sham DFT when the inter-subsystem density overlap is low. We also conclude that to make FDE a suitable method for describing molecular adsorption at surfaces, kinetic energy density functionals that go beyond the GGA level must be employed.

Genova, Alessandro; Pavanello, Michele, E-mail: m.pavanello@rutgers.edu [Department of Chemistry, Rutgers University, Newark, New Jersey 07102 (United States); Ceresoli, Davide [Department of Chemistry, Rutgers University, Newark, New Jersey 07102 (United States); CNR-ISTM, Institute of Molecular Sciences and Technologies, Milano (Italy)

2014-11-07T23:59:59.000Z

468

Modeling of Heat Transfer in Geothermal Heat Exchangers  

E-Print Network [OSTI]

, University of Lund, Sweden, [7] Fang, Z., Diao, N., and Cui, P., Discontinuous operation of geothermal heat exchangers [J], Tsinghua Science and Technology. , 2002, 7 194?197. [8] Hellstrom, G., Ground heat storage -- Thermal analysis of duct storage... systems [D], Department of Mathem Sweden, 1991. [9] Mei, V. C. and Baxter, V. D., Performance of a ground-coupled heat pump with multiple dissimilar U-tu Transactions, 1986, 92 Part 2, 22-25. [10] Yavuzturk, C., Spitler, J. D. and Rees, S. J., A...

Cui, P.; Man, Y.; Fang, Z.

2006-01-01T23:59:59.000Z

469

Combined Heat and Power Plant Steam Turbine  

E-Print Network [OSTI]

Combined Heat and Power Plant Steam Turbine Steam Turbine Chiller Campus Heat Load Steam (recovered waste heat) Gas Turbine University Substation High Pressure Natural Gas Campus Electric Load Southern Generator Heat Recovery Alternative Uses: 1. Campus heating load 2. Steam turbine chiller to campus cooling

Rose, Michael R.

470

Heat Supply Who What Where and -Why  

E-Print Network [OSTI]

heat and power plants (CHP) and other heat technologies ...................................10 2Heat Supply in Denmark Who What Where and - Why #12;Title: Heat Supply in Denmark - Who What Where: MONTAGEbureauet Aps Printing: Kailow Graphic Cover photo: Miklos Szabo #12;HEAT SUPPLY IN DENMARK WHO WHAT WHERE

Columbia University

471

Heat pipe with embedded wick structure  

DOE Patents [OSTI]

A heat pipe has an embedded wick structure that maximizes capillary pumping capability. Heat from attached devices such as integrated circuits evaporates working fluid in the heat pipe. The vapor cools and condenses on a heat dissipation surface. The condensate collects in the wick structure, where capillary pumping returns the fluid to high heat areas.

Adkins, Douglas Ray (Albuquerque, NM); Shen, David S. (Albuquerque, NM); Tuck, Melanie R. (Albuquerque, NM); Palmer, David W. (Albuquerque, NM); Grafe, V. Gerald (Corrales, NM)

1998-01-01T23:59:59.000Z

472

Heat pipe with embedded wick structure  

DOE Patents [OSTI]

A heat pipe has an embedded wick structure that maximizes capillary pumping capability. Heat from attached devices such as integrated circuits evaporates working fluid in the heat pipe. The vapor cools and condenses on a heat dissipation surface. The condensate collects in the wick structure, where capillary pumping returns the fluid to high heat areas.

Adkins, Douglas Ray (Albuquerque, NM); Shen, David S. (Albuquerque, NM); Tuck, Melanie R. (Albuquerque, NM); Palmer, David W. (Albuquerque, NM); Grafe, V. Gerald (Corrales, NM)

1999-01-01T23:59:59.000Z

473

IEA HPP Annex 41 Cold Climate Heat  

E-Print Network [OSTI]

of Air-Source Heat Pumps Van D. Baxter Oak Ridge National Laboratory European Heat Pump Summit Nuremberg ­ Cold Climate Heat Pumps Improving low ambient temperature performance of air-source heat pumps as having large number of hours with OD temperature -7 °C (19 °F). Air-source heat pumps (ASHP

Oak Ridge National Laboratory

474

Heat pipe with embedded wick structure  

DOE Patents [OSTI]

A heat pipe has an embedded wick structure that maximizes capillary pumping capability. Heat from attached devices such as integrated circuits evaporates working fluid in the heat pipe. The vapor cools and condenses on a heat dissipation surface. The condensate collects in the wick structure, where capillary pumping returns the fluid to high heat areas. 7 figs.

Adkins, D.R.; Shen, D.S.; Tuck, M.R.; Palmer, D.W.; Grafe, V.G.

1998-06-23T23:59:59.000Z

475

Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump  

DOE Patents [OSTI]

Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium.

Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI); Marsala, Joseph (Glen Ellyn, IL)

1994-11-29T23:59:59.000Z

476

Periodic Exponential Shear of Complex Fluids  

E-Print Network [OSTI]

We define a class of flows with exponential kinematics termed Periodic Exponential Shear (PES) flow which involve periodic exponential stretching of fluid elements along with their rotation. We exhibit analytical and numerical results for PES flow by using the Oldroyd-B model for viscoelastic fluids. We calculate the growth in the shear and the normal stresses analytically as well as demonstrate that repeated application of the flow leads to stable oscillatory shear and normal stresses. We define a material function applicable to a periodic, unsteady shear flow and show numerically that this material function exhibits deformation-rate thickening behavior for viscoelastic fluids subject to PES flow. We demonstrate the feasibility of PES flow by presenting preliminary experimental results from a controlled-strain rate rheometer, using a Newtonian mineral oil.

Chirag Kalelkar; Gareth McKinley

2012-05-31T23:59:59.000Z

477

Joule Heating and Anomalous Resistivity in the Solar Corona  

E-Print Network [OSTI]

Recent radioastronomical observations of Faraday rotation in the solar corona can be interpreted as evidence for coronal currents, with values as large as $2.5 \\times 10^9$ Amperes (Spangler 2007). These estimates of currents are used to develop a model for Joule heating in the corona. It is assumed that the currents are concentrated in thin current sheets, as suggested by theories of two dimensional magnetohydrodynamic turbulence. The Spitzer result for the resistivity is adopted as a lower limit to the true resistivity. The calculated volumetric heating rate is compared with an independent theoretical estimate by Cranmer et al (2007). This latter estimate accounts for the dynamic and thermodynamic properties of the corona at a heliocentric distance of several solar radii. Our calculated Joule heating rate is less than the Cranmer et al estimate by at least a factor of $3 \\times 10^5$. The currents inferred from the observations of Spangler (2007) are not relevant to coronal heating unless the true resistivity is enormously increased relative to the Spitzer value. However, the same model for turbulent current sheets used to calculate the heating rate also gives an electron drift speed which can be comparable to the electron thermal speed, and larger than the ion acoustic speed. It is therefore possible that the coronal current sheets are unstable to current-driven instabilities which produce high levels of waves, enhance the resistivity and thus the heating rate.

Steven R. Spangler

2008-12-22T23:59:59.000Z

478

QUANTIFICATION OF HEAT FLUX FROM A REACTING THERMITE SPRAY  

SciTech Connect (OSTI)

Characterizing the combustion behaviors of energetic materials requires diagnostic tools that are often not readily or commercially available. For example, a jet of thermite spray provides a high temperature and pressure reaction that can also be highly corrosive and promote undesirable conditions for the survivability of any sensor. Developing a diagnostic to quantify heat flux from a thermite spray is the objective of this study. Quick response sensors such as thin film heat flux sensors can not survive the harsh conditions of the spray, but more rugged sensors lack the response time for the resolution desired. A sensor that will allow for adequate response time while surviving the entire test duration was constructed. The sensor outputs interior temperatures of the probes at known locations and utilizes an inverse heat conduction code to calculate heat flux values. The details of this device are discussed and illustrated. Temperature and heat flux measurements of various thermite spray conditions are reported. Results indicate that this newly developed energetic material heat flux sensor provides quantitative data with good repeatability.

Eric Nixon; Michelle Pantoya

2009-07-01T23:59:59.000Z

479

Parc Periodical | Photosynthetic Antenna Research Center  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recoveryLaboratorySpeedingOptimizingToolsto controlParc Periodical Parc Periodical

480

Active heat transfer enhancement in integrated fan heat sinks  

E-Print Network [OSTI]

Modern computer processors require significant cooling to achieve their full performance. The "efficiency" of heat sinks is also becoming more important: cooling of electronics consumes 1% of worldwide electricity use by ...

Staats, Wayne Lawrence

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


481

Boise City Geothermal District Heating District Heating Low Temperatur...  

Open Energy Info (EERE)

66.20x109 Btuyr 19.40 GWhyr Delat T 53.00 F Load Factor 0.07 Contact Kent Johnson; 208-384-3926 References Oregon Institute of Technology's Geo-Heat Center1 Boise...

482

Potassium, Uranium, Thorium Radiogenic Heat Contribution To Heat...  

Open Energy Info (EERE)

has been explained by the possible presence of a buried felsic pluton. Alternately, high K, U, Th abundances have been proposed to account for part of the high heat flow. The mean...

483

An Energy Savings Model for the Heat Treatment of Castings  

SciTech Connect (OSTI)

An integrated system of software, databases, and design rules have been developed, verified, and to be marketed to enable quantitative prediction and optimization of the heat treatment of aluminum castings to increase quality, increase productivity, reduce heat treatment cycle times and reduce energy consumption. The software predicts the thermal cycle in critical locations of individual components in a furnace, the evolution of microstructure, and the attainment of properties in heat treatable aluminum alloy castings. The model takes into account the prior casting process and the specific composition of the component. The heat treatment simulation modules can be used in conjunction with software packages for simulation of the casting process. The system is built upon a quantitative understanding of the kinetics of microstructure evolution in complex multicomponent alloys, on a quantitative understanding of the interdependence of microstructure and properties, on validated kinetic and thermodynamic databases, and validated quantitative models.

Y. Rong; R. Sisson; J. Morral; H. Brody

2006-12-31T23:59:59.000Z

484

Simplified motional heating rate measurements of trapped ions  

E-Print Network [OSTI]

We have measured motional heating rates of trapped atomic ions, a factor that can influence multi-ion quantum logic gate fidelities. Two simplified techniques were developed for this purpose: one relies on Raman sideband detection implemented with a single laser source, while the second is even simpler and is based on time-resolved fluorescence detection during Doppler recooling. We applied these methods to determine heating rates in a microfrabricated surface-electrode trap made of gold on fused quartz, which traps ions 40 microns above its surface. Heating rates obtained from the two techniques were found to be in reasonable agreement. In addition, the trap gives rise to a heating rate of 300 plus or minus 30 per second for a motional frequency of 5.25 MHz, substantially below the trend observed in other traps.

Epstein, R J; Leibfried, D; Wesenberg, J H; Bollinger, J J; Amini, J M; Blakestad, R B; Britton, J; Home, J P; Itano, W M; Jost, J D; Knill, E; Langer, C; Ozeri, R; Shiga, N; Wineland, D J

2007-01-01T23:59:59.000Z