Sample records for time period heating

  1. Studies of non-diffusive heat conduction through spatially periodic and time-harmonic thermal excitations

    E-Print Network [OSTI]

    Collins, Kimberlee C. (Kimberlee Chiyoko)

    2015-01-01T23:59:59.000Z

    Studies of non-diffusive heat conduction provide insight into the fundamentals of heat transport in condensed matter. The mean free paths (MFPs) of phonons that are most important for conducting heat are well represented ...

  2. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag Jump to:ID8/OrganizationTechProbSolutions Jump to: navigation,TimePeriod Jump to:

  3. Technical Note Solution of periodic heating problems by the

    E-Print Network [OSTI]

    Barber, James R.

    , the valves of an internal combustion engine experience direct heating from the combusting gases, cooling from numerical simulation of every cycle. It also permits a direct solution for the nodal temperatures-dimensional) examples and the obvious way to proceed is to use numerical simulation [5] ± i.e., to step in time solving

  4. Efficient Mining of Partial Periodic Patterns in Time Series Database

    E-Print Network [OSTI]

    Dong, Guozhu

    Efficient Mining of Partial Periodic Patterns in Time Series Database In ICDE 99 Jiawei Han \\Lambda peri­ odic patterns in time­series databases, is an interesting data mining problem. Previous studies several algorithms for efficient mining of par­ tial periodic patterns, by exploring some interesting

  5. 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

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

    E-Print Network [OSTI]

    California at Irvine, University of

    UC Berkeley Heat/Ventilation Curtailment Period DECEMBER 24, 2011 through JANUARY 1, 2012 Each year and January 1, 2012 in order to conserve energy, most campus buildings will be closed and heat and ventilation://hrweb.berkeley.edu/ for more information. Barrows Hall BUILDINGS SCHEDULED TO BE WITHOUT HEAT/VENTILATION Bechtel Engineering

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

    E-Print Network [OSTI]

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

    2003-12-18T23:59:59.000Z

    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.

  8. An analysis of periodic heat flow through a plane slab

    E-Print Network [OSTI]

    Gibson, Daniel Morgan

    1958-01-01T23:59:59.000Z

    of the slice are shown in Figure 2. The corresponding ener~ balance is: kA(t l ? t )6Q kA(t l - t )aR or t I + t (M ? 2) + where 0 h A(t - t )gg kA(tl t g'9 i~N 'i&GY DlA('HAlill 10d HA1F-is&IC'. " Figu o 3 The ener, ~ dia?ram for thc half... + nc~. g 2 + 't2 (LYJ 2)+t g2g, 6 ~ cl. , ')61, 1 ~9 L. , to + tz(V, ? 2) ? , - t 1. + ~61. 1 2. - . ". ' + . '2O. O = ~6. g 61. 1 + 20. 0 2. - 2 + 262. 2Nbtb + ti(M - 2Nb ' ) + 2t4 i 2 . 2 0 +262. " 2. -2 . 2 -2 +2 20. 0 ~26. 0 Net heat...

  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]

    Treur, Jan

    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

  10. Controlling mobility via rapidly oscillating time-periodic stimulus

    E-Print Network [OSTI]

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

    2014-03-26T23:59:59.000Z

    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.

  11. Local Lyapunov Functions for periodic and finite-time ODEs

    E-Print Network [OSTI]

    Hafstein, Sigurður Freyr

    Local Lyapunov Functions for periodic and finite-time ODEs Peter Giesl and Sigurdur Hafstein Abstract Lyapunov functions for general systems are difficult to construct. How- ever, for autonomous Lyapunov function by solving a matrix equa- tion. Consequently, the same function is a local Lyapunov

  12. Time-periodic solutions of the Benjamin-Ono equation

    SciTech Connect (OSTI)

    Ambrose , D.M.; Wilkening, Jon

    2008-04-01T23:59:59.000Z

    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.

  13. Non-existence of time-periodic vacuum spacetimes

    E-Print Network [OSTI]

    Alexakis, Spyros

    2015-01-01T23:59:59.000Z

    We prove that smooth asymptotically flat solutions to the Einstein vacuum equations which are assumed to be periodic in time, are in fact stationary in a neighborhood of infinity. Our result applies under physically relevant regularity assumptions purely at the level of the initial data. In particular, our work removes the assumption of analyticity up to null infinity in [Bicak, Scholtz, and Tod; 2010]. The proof relies on extending a suitably constructed "candidate" Killing vector field from null infinity, via Carleman-type estimates obtained in [Alexakis, Schlue, Shao; 2013].

  14. 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

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

    E-Print Network [OSTI]

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

    2015-01-01T23:59:59.000Z

    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.

  16. TRANSPORT OF HEAT, WATER VAPOR AND CARBON DOXIDE BY LONG PERIOD EDDIES IN THE STABLE BOUNDARY LAYER

    SciTech Connect (OSTI)

    Kurzeja, R.

    2010-07-26T23:59:59.000Z

    The vertical transport of heat and trace chemicals for a night in April has been studied with a wavelet analysis and conventional one-hour averages. It was found that for the night of April 20, 2009, turbulent kinetic energy, heat and trace chemicals were transported directed downward from the jet core. The most significant periods for this transport were less than 5 minutes and greater than one hour with intermittent transport taking place in the 5 min to 1 hour time frame. The nocturnal boundary layer is characterized by turbulent intermittency, long period oscillations, and a slow approach to equilibrium, (Mahrt, 1999). Although turbulence is usually maintained by surface friction, downward transport from low-level jets can also play an important role in turbulence maintenance and in the transport of scalars, Mahrt (1999), Banta et al. (2006). The eddy covariance flux measurement technique assumes continuous turbulence which is unusual in the stable boundary because significant flux transport occurs via turbulent eddies whose periods are long compared with the averaging time (Goulden et al., 1996). Systematic error in eddy flux measurements is attributed mainly to the neglect of long period eddies. Banta et al. (2006) noted that observations of turbulence below the low level jet suggested that while upward transport of turbulence kinetic energy (TKE) is common, downward transport from the jet can also occur. They found that in the CASES 99 experiments that turbulence scaled well with the strength of the low-level jet, and that surface cooling was more important than surface roughness. Because nocturnal turbulence is intermittent and non-stationary, the appropriate averaging time for calculation of TKE and EC fluxes is not obvious. Wavelet analysis is, thus, a more suitable analysis tool than conventional Fourier analysis.

  17. Heat-Pipe Development for Advanced Energy Transport Concepts Final Report Covering the Period January 1999 through September 2001

    SciTech Connect (OSTI)

    R.S.Reid; J.F.Sena; A.L.Martinez

    2002-10-01T23:59:59.000Z

    This report summarizes work in the Heat-pipe Technology Development for the Advanced Energy Transport Concepts program for the period January 1999 through September 2001. A gas-loaded molybdenum-sodium heat pipe was built to demonstrate the active pressure-control principle applied to a refractory metal heat pipe. Other work during the period included the development of processing procedures for and fabrication and testing of three types of sodium heat pipes using Haynes 230, MA 754, and MA 956 wall materials to assess the compatibility of these materials with sodium. Also during this period, tests were executed to measure the response of a sodium heat pipe to the penetration of water.

  18. Heat release by controlled continuous-time Markov jump processes

    E-Print Network [OSTI]

    Paolo Muratore-Ginanneschi; Carlos Mejía-Monasterio; Luca Peliti

    2012-12-17T23:59:59.000Z

    We derive the equations governing the protocols minimizing the heat released by a continuous-time Markov jump process on a one-dimensional countable state space during a transition between assigned initial and final probability distributions in a finite time horizon. In particular, we identify the hypotheses on the transition rates under which the optimal control strategy and the probability distribution of the Markov jump problem obey a system of differential equations of Hamilton-Bellman-Jacobi-type. As the state-space mesh tends to zero, these equations converge to those satisfied by the diffusion process minimizing the heat released in the Langevin formulation of the same problem. We also show that in full analogy with the continuum case, heat minimization is equivalent to entropy production minimization. Thus, our results may be interpreted as a refined version of the second law of thermodynamics.

  19. Periodic schedules for Unitary Timed Weighted Event Graphs

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Event Graph model (TEG also called marked graphs [5]) and dataflow graphs, oftenly used in the computer questions are polynomially solved for ordinary TEG [1], [5], [6], [8]. In particular, it has been shown that if a TEG is live, there always exists a periodic schedule with the optimal throughput (i.e. with the same

  20. Experimental validation of advanced regulations for superconducting magnet cooling undergoing periodic heat loads

    SciTech Connect (OSTI)

    Lagier, B.; Rousset, B.; Hoa, C.; Bonnay, P. [CEA Grenoble INAC/SBT, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France)

    2014-01-29T23:59:59.000Z

    Superconducting magnets used in tokamaks undergo periodic heat load caused by cycling plasma operations inducing AC losses, neutrons fluxes and eddy currents in magnet structures. In the cryogenic system of JT60-SA tokamak, the Auxiliary Cold Box (ACB) distributes helium from the refrigerator to the cryogenic users and in particular to the superconducting magnets. ACB comprises a saturated helium bath with immersed heat exchangers, extracting heat from independent cooling loops. The supercritical helium flow in each cooling loop is driven by a cold circulator. In order to safely operate the refrigerator during plasma pulses, the interface between the ACB and the refrigerator shall be as stable as possible, with well-balanced bath inlet and outlet mass flows during cycling operation. The solution presented in this paper relies on a combination of regulations to smooth pulsed heat loads and to keep a constant refrigeration power during all the cycle. Two smoothing strategies are presented, both regulating the outlet mass flow of the bath: the first one using the bath as a thermal buffer and the second one storing energy in the loop by varying the cold circulator speed. The bath outlet mass flow is also controlled by an immersed resistive heater which enables a constant evaporation rate in the bath when power coming from the loops is decreasing. The refrigeration power is controlled so that the compensating power remains within an acceptable margin. Experimental validation is achieved using the HELIOS facility. This facility running at CEA Grenoble since 2010 is a scaled down model of the ACB bath and Central Solenoid magnet cooling loop of the JT60-SA tokamak. Test results show performances and robustness of the regulations.

  1. 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

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

    E-Print Network [OSTI]

    Warren, Mashuri L.

    2013-01-01T23:59:59.000Z

    Solar Energy Systems for Heating and Cooling. May, 1978. (Washington:Hemisphere heating, Publishing Corp. , 1978),INPUT CONDITIONS FOR ACTIVE SOLAR HEATING SYSTEMS Mashuri L.

  3. Implementation issues for real-time optimization of a crude unit heat exchanger network

    E-Print Network [OSTI]

    Skogestad, Sigurd

    1 Implementation issues for real-time optimization of a crude unit heat exchanger network Tore Lid of real time optimization results in a crude unit heat exchanger network. Two different control strategies

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

    E-Print Network [OSTI]

    Warren, Mashuri L.

    2013-01-01T23:59:59.000Z

    OF A BUILDING UNDER HEAT INPUT CONDITIONS FOR ACTIVE SOLAROF A BUILDING UNDER HEAT INPUT CONDITIONS FOR ACTIVE SOLARbuilding to changes in heat input, and to predict room and

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

    E-Print Network [OSTI]

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

    2002-02-12T23:59:59.000Z

    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.

  6. Efficient Solvers for Nonlinear Time-Periodic Eddy Current F. Bachinger

    E-Print Network [OSTI]

    Schoeberl, Joachim

    Efficient Solvers for Nonlinear Time-Periodic Eddy Current Problems F. Bachinger U. Langer J. Sch-periodic eddy current problems, ranging from the description of the nonlinearity to an efficient solution setup, the magnetic field and the thereby generated eddy currents hardly penetrate into conducting

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

    E-Print Network [OSTI]

    Bartuccelli, Michele

    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

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    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

  9. 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

  10. CHP: It's Time for Combined Heat and Power

    E-Print Network [OSTI]

    Herweck, R.

    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... to 90% CHP DE can cut fuel consumption per unit of output to half or a third of conventional usage… especially natural gas supplies now in heavy demand Economic Development: Combined Heat and Power #0;9 Reduces the cost of new electricity T...

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

    E-Print Network [OSTI]

    Chen, Yunji; Hu, Weiwu

    2009-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Cesar R. de Oliveira; Mariza S. Simsen

    2009-07-31T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Boyer, Edmond

    1 HEAT TRANSFERS IN A DOUBLE SKIN ROOF VENTILATED BY NATURAL CONVECTION IN SUMMER TIME P. H and the sheet metal: This is ventilation by natural convection. The remaining conductive heat from the sheet or in tropical and arid countries. In this work, radiation, convection and conduction heat transfers

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

    E-Print Network [OSTI]

    Warren, Mashuri L.

    2013-01-01T23:59:59.000Z

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

  15. Modeling laser-induced periodic surface structures: Finite-difference time-domain feedback simulations

    SciTech Connect (OSTI)

    Skolski, J. Z. P., E-mail: j.z.p.skolski@utwente.nl; Vincenc Obona, J. [Materials innovation institute M2i, Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Römer, G. R. B. E.; Huis in 't Veld, A. J. [Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)

    2014-03-14T23:59:59.000Z

    A model predicting the formation of laser-induced periodic surface structures (LIPSSs) is presented. That is, the finite-difference time domain method is used to study the interaction of electromagnetic fields with rough surfaces. In this approach, the rough surface is modified by “ablation after each laser pulse,” according to the absorbed energy profile, in order to account for inter-pulse feedback mechanisms. LIPSSs with a periodicity significantly smaller than the laser wavelength are found to “grow” either parallel or orthogonal to the laser polarization. The change in orientation and periodicity follow from the model. LIPSSs with a periodicity larger than the wavelength of the laser radiation and complex superimposed LIPSS patterns are also predicted by the model.

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

    E-Print Network [OSTI]

    Wright, Lance Cole

    1996-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Ruoxi Xiang; Michael Small

    2014-06-18T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    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

  19. Optimal Operation of Finite-time Tricycles with Heat Conduction Losses Raj K. Pathria

    E-Print Network [OSTI]

    Salamon, Peter

    -principle limits to the finite-time operation of a cycling working fluid acting as an agent in the transfer of heat of Curzon and Ahlborn for the efficiency of a Carnot-like heat engine at maximu m power. PACS: 05.70.Ln, 05 means "internall y reversible" and allows us to treat the subsystems participating in a process as being

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

    SciTech Connect (OSTI)

    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

    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.

  1. POWER ELECTRONICS HARMONIC ANALYSIS BASED ON THE LINEAR TIME PERIODIC MODELING. APPLICATIONS FOR AC/DC/AC POWER

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    /Simulink simulations. Key words: power system harmonics, power electronic, linear time periodic modeling, PWM, control1 POWER ELECTRONICS HARMONIC ANALYSIS BASED ON THE LINEAR TIME PERIODIC MODELING. APPLICATIONS in power electronic systems. The considered system is described by a set of differential equations, which

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

    E-Print Network [OSTI]

    Michele Bartuccelli; Jonathan Deane; Guido Gentile

    2012-07-18T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    G. van Baalen

    2004-11-04T23:59:59.000Z

    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.

  4. On 3D instabilities of 2D time-periodic flows - Department of ...

    E-Print Network [OSTI]

    The Karman vortex street, the 2D periodically shedding wake of a circular cylinder, is the prototypical example. We shall consider this as well as a periodically ...

  5. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)IntegratedSpeeding access toTest andOptimize832 2.860SelectedGLOW DISCHARGE REPORTHEAT

  6. A study of short-time periodic variation of the B8 solar neutrino flux at Super-Kamiokande

    E-Print Network [OSTI]

    J. Yoo; for the Super-Kamiokande Collaboration

    2003-09-15T23:59:59.000Z

    Super-Kamiokande(SK) is a real-time detector capable of measuring the exact time of solar neutrino events. This, combined with a relatively high yield of these events of roughly 15 per day, allows a search for short-time variations in the observed flux. Using all 1496 days of SK-I's solar data, we looked for periodic variations of the observed solar neutrino flux, and found no significant periodicity.

  7. Acoustic sensor for real-time control for the inductive heating process

    DOE Patents [OSTI]

    Kelley, John Bruce; Lu, Wei-Yang; Zutavern, Fred J.

    2003-09-30T23:59:59.000Z

    Disclosed is a system and method for providing closed-loop control of the heating of a workpiece by an induction heating machine, including generating an acoustic wave in the workpiece with a pulsed laser; optically measuring displacements of the surface of the workpiece in response to the acoustic wave; calculating a sub-surface material property by analyzing the measured surface displacements; creating an error signal by comparing an attribute of the calculated sub-surface material properties with a desired attribute; and reducing the error signal below an acceptable limit by adjusting, in real-time, as often as necessary, the operation of the inductive heating machine.

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

    E-Print Network [OSTI]

    Zhang, J.

    2006-01-01T23:59:59.000Z

    a new system control theory, that is computerize the real-time frequency conversion control or area,time, mode of heat transformation and temperature grads. The aim of the new theory is promoting the efficiency of energy conversion and minimizing...

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

    E-Print Network [OSTI]

    Y. S. Kim

    2010-09-26T23:59:59.000Z

    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.

  10. Time variability of AGN and heating of cooling flows

    E-Print Network [OSTI]

    Carlo Nipoti; James Binney

    2005-05-03T23:59:59.000Z

    There is increasing evidence that AGN mechanical feedback is important in the energetics of cooling flows in galaxies and galaxy clusters. We investigate the implications of the variability of AGN mechanical luminosity L_m on observations of cooling flows and radio galaxies in general. It is natural to assume that l=ln(L_m/L_x) is a Gaussian process. Then L_m will be log-normally distributed at fixed cooling luminosity L_x, and the variance in a measure of L_m will increase with the time-resolution of the measure. We test the consistency of these predictions with existing data. These tests hinge on the power spectrum of l(t). Monitoring of Seyfert galaxies combined with estimates of the duty cycle of quasars imply flicker noise spectra, similar to those of microquasars. We combine a sample of sources in cooling flows that have cavities with the assumption that the average mechanical luminosity of the AGN equals L_x. Given that the mechanical luminosities are characterized by flicker noise, we find that their spectral amplitudes lie between the estimated amplitudes of quasars and the measured values for the radio luminosities of microquasars. The model together with the observation that powerful radio galaxies lie within a narrow range in optical luminosity, predicts the luminosity function of radio galaxies, in agreement with observations. Forthcoming radio surveys will test the prediction that the luminosity function turns over at about the smallest luminosities so far probed. [Abridged

  11. Effect of heat treatment time on microstructure and electrical conductivity in LATP glass ceramics

    SciTech Connect (OSTI)

    Sonigra, Dhiren, E-mail: somans@iitb.ac.in, E-mail: ajit.kulkarni@iitb.ac.in; Soman, Swati, E-mail: somans@iitb.ac.in, E-mail: ajit.kulkarni@iitb.ac.in; Kulkarni, Ajit R., E-mail: somans@iitb.ac.in, E-mail: ajit.kulkarni@iitb.ac.in [Dept. of Metallurgical Engineering and Materials Science, IIT Bombay, Mumbai-400076 (India)

    2014-04-24T23:59:59.000Z

    Glass-ceramic is prepared by heat treatment of melt quenched 14Li{sub 2}O?9Al{sub 2}O{sub 3}?38TiO{sub 2}?39P{sub 2}O{sub 5} glass in the vicinity of crystallization temperature. Growth of ceramic phase is controlled by tuning heat treatment time at fixed temperature. Ceramic phase was identified to be LiTi{sub 2}(PO{sub 4}){sub 3} from X Ray Diffraction analysis. Microstructural evolution of this phase with hold time was observed under high resolution Scanning Electron Microscope. DC conductivity is observed to increase by 4-5 orders of magnitude in this glass-ceramic compared to parent glass. However, formation of pores and cracks with very large heat treatment time seem to hinder further increase of conductivity.

  12. Time-delayed apparent excess heat generation in electrolysis fusion experiments

    SciTech Connect (OSTI)

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

    1991-04-10T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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}.

  14. Towards a 3D time dependent Fokker-Planck solver for modelling RF heating in realistic tokamak geometry

    E-Print Network [OSTI]

    . Hedin, Ion Cyclotron Heating in Toroidal Plasmas, Ph.D. thesis, Royal Institute of Technology StockholmTowards a 3D time dependent Fokker-Planck solver for modelling RF heating in realistic tokamak supercomputers and the need for predictive tools to guide the experiments, modelling radio frequency heating

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

    SciTech Connect (OSTI)

    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

    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.

  16. Cooperative heat transfer and ground coupled storage system

    DOE Patents [OSTI]

    Metz, Philip D. (Rocky Point, NY)

    1982-01-01T23:59:59.000Z

    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.

  17. Universality in short-time critical gluodynamics with heat-bath-inspired algorithms

    E-Print Network [OSTI]

    Rafael B. Frigori

    2010-04-14T23:59:59.000Z

    Short-time dynamics technique is used to study the relaxation process for the (2+1)-dimensional critical gluodynamics of the SU(2) lattice gauge theory. A generalized class of heat-bath-inspired updating algorithms was employed during the short-time regime of the dynamic evolution for performance comparison. The static and dynamic critical exponents of the theory were measured, serving as a dynamic benchmark for algorithmic efficiency. Our results are in agreement with predictions from universality hypothesis and suggest that there is an underlying universal dynamics shared by the analyzed algorithms.

  18. A (MAX,+) ALGEBRA FOR NON-STATIONARY PERIODIC TIMED DISCRETE EVENT Guillaume P. Brat,1

    E-Print Network [OSTI]

    Garg, Vijay

    ], behaviors of DES are captured by timed event graphs (TEG), a class of timed Petri nets ( 9] o ers a comprehensive review of Petri nets). In TEGs, any place has only one input and one out- put transition, and. Event sequences consist of the r- ing times of transitions. A TEG with N transitions is represented

  19. Looking for granulation and periodicity imprints in the sunspot time series

    E-Print Network [OSTI]

    Lopes, Ilidio

    2015-01-01T23:59:59.000Z

    The sunspot activity is the end result of the cyclic destruction and regeneration of magnetic fields by the dynamo action. We propose a new method to analyze the daily sunspot areas data recorded since 1874. By computing the power spectral density of daily data series using the Mexican hat wavelet, we found a power spectrum with a well-defined shape, characterized by three features. The first term is the 22 yr solar magnetic cycle, estimated in our work to be of 18.43 yr. The second term is related to the daily volatility of sunspots. This term is most likely produced by the turbulent motions linked to the solar granulation. The last term corresponds to a periodic source associated with the solar magnetic activity, for which the maximum of power spectral density occurs at 22.67 days. This value is part of the 22-27 day periodicity region that shows an above-average intensity in the power spectra. The origin of this 22.67 day periodic process is not clearly identified, and there is a possibility that it can be...

  20. The long time behavior of Brownian motion in tilted periodic potentials

    E-Print Network [OSTI]

    Liang Cheng

    2015-01-20T23:59:59.000Z

    Jan 6, 2015 ... In order to obtain more quantitative information about dynamical behaviors, we .... 2. Convergence of long time average velocity VF for the ...

  1. A charged particle in a homogeneous magnetic field accelerated by a time periodic Aharonov-Bohm flux

    E-Print Network [OSTI]

    T. Kalvoda; P. Stovicek

    2011-07-14T23:59:59.000Z

    We consider a nonrelativistic quantum charged particle moving on a plane under the influence of a uniform magnetic field and driven by a periodically time-dependent Aharonov-Bohm flux. We observe an acceleration effect in the case when the Aharonov-Bohm flux depends on time as a sinusoidal function whose frequency is in resonance with the cyclotron frequency. In particular, the energy of the particle increases linearly for large times. An explicit formula for the acceleration rate is derived with the aid of the quantum averaging method, and then it is checked against a numerical solution with a very good agreement.

  2. Trigger - and heat-transfer times measured during experimental molten-fuel-interactions

    SciTech Connect (OSTI)

    Spitznagel, N.; Dürig, T.; Zimanowski, B. [Physikalisch-Vulkanologisches Labor, Universität Würzburg, Pleicherwall 1, 97070 Würzburg (Germany)] [Physikalisch-Vulkanologisches Labor, Universität Würzburg, Pleicherwall 1, 97070 Würzburg (Germany)

    2013-10-15T23:59:59.000Z

    A modified setup featuring high speed high resolution data and video recording was developed to obtain detailed information on trigger and heat transfer times during explosive molten fuel-coolant-interaction (MFCI). MFCI occurs predominantly in configurations where water is entrapped by hot melt. The setup was modified to allow direct observation of the trigger and explosion onset. In addition the influences of experimental control and data acquisition can now be more clearly distinguished from the pure phenomena. More precise experimental studies will facilitate the description of MFCI thermodynamics.

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

    E-Print Network [OSTI]

    Aydin, Hakan

    , 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

  4. The application of complex network time series analysis in turbulent heated jets

    SciTech Connect (OSTI)

    Charakopoulos, A. K.; Karakasidis, T. E., E-mail: thkarak@uth.gr; Liakopoulos, A. [Laboratory of Hydromechanics and Environmental Engineering, Department of Civil Engineering, University of Thessaly, 38334 Volos (Greece)] [Laboratory of Hydromechanics and Environmental Engineering, Department of Civil Engineering, University of Thessaly, 38334 Volos (Greece); Papanicolaou, P. N. [School of Civil Engineering, Department of Water Resources and Environmental Engineering, National Technical University of Athens, 5 Heroon Polytechniou St., 15780 Zografos (Greece)] [School of Civil Engineering, Department of Water Resources and Environmental Engineering, National Technical University of Athens, 5 Heroon Polytechniou St., 15780 Zografos (Greece)

    2014-06-15T23:59:59.000Z

    In the present study, we applied the methodology of the complex network-based time series analysis to experimental temperature time series from a vertical turbulent heated jet. More specifically, we approach the hydrodynamic problem of discriminating time series corresponding to various regions relative to the jet axis, i.e., time series corresponding to regions that are close to the jet axis from time series originating at regions with a different dynamical regime based on the constructed network properties. Applying the transformation phase space method (k nearest neighbors) and also the visibility algorithm, we transformed time series into networks and evaluated the topological properties of the networks such as degree distribution, average path length, diameter, modularity, and clustering coefficient. The results show that the complex network approach allows distinguishing, identifying, and exploring in detail various dynamical regions of the jet flow, and associate it to the corresponding physical behavior. In addition, in order to reject the hypothesis that the studied networks originate from a stochastic process, we generated random network and we compared their statistical properties with that originating from the experimental data. As far as the efficiency of the two methods for network construction is concerned, we conclude that both methodologies lead to network properties that present almost the same qualitative behavior and allow us to reveal the underlying system dynamics.

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

    SciTech Connect (OSTI)

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

    2011-06-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2011-01-04T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  8. Chemical heat pump

    DOE Patents [OSTI]

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

    1980-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Hudson II, Carl Randy [ORNL

    2004-09-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    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

    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 ...

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

    SciTech Connect (OSTI)

    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

    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.

  12. 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)

    Rogers, J.; Porter, K.

    2012-03-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    1 Op%mal Scheduling of Combined Heat and Power (CHP) Plants1 under Time-sensi%ve Electricity Prices Summary In this case study, a CHP plant increases its profit%ons with the power grid 4 Power Grid CHP plant Typically mul%ple boilers and turbines

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

    E-Print Network [OSTI]

    Hanyk, Ladislav

    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

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Jolanta Socala; Wojciech M. Zajaczkowski

    2011-03-21T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Socala, Jolanta

    2011-01-01T23:59:59.000Z

    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.

  18. Integrating preconcentrator heat controller

    DOE Patents [OSTI]

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

    2007-10-16T23:59:59.000Z

    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.

  19. Heat transfers in a double-skin roof ventilated by natural convection in summer time

    E-Print Network [OSTI]

    Biwole, Pascal; Pompeo, C

    2013-01-01T23:59:59.000Z

    The double-skin roofs investigated in this paper are formed by adding a metallic screen on an existing sheet metal roof. The system enhances passive cooling of dwellings and can help diminishing power costs for air conditioning in summer or in tropical and arid countries. In this work, radiation, convection and conduction heat transfers are investigated. Depending on its surface properties, the screen reflects a large amount of oncoming solar radiation. Natural convection in the channel underneath drives off the residual heat. The bi-dimensional numerical simulation of the heat transfers through the double skin reveals the most important parameters for the system's efficiency. They are, by order of importance, the sheet metal surface emissivity, the screen internal and external surface emissivity, the insulation thickness and the inclination angle for a channel width over 6 cm. The influence of those parameters on Rayleigh and Nusselt numbers is also investigated. Temperature and air velocity profiles on seve...

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

    E-Print Network [OSTI]

    are demonstrated for a variety of engineering problems. Since most engineering devices have thermal energy and engineering applications of heat transfer including conduction, convection, and radiation. Course Learning Objectives: In this course, students will learn how to 1. Model engineering problems that have conduction

  1. Chemical heat pump

    DOE Patents [OSTI]

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

    1984-01-01T23:59:59.000Z

    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.

  2. Chemical heat pump

    DOE Patents [OSTI]

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

    1984-01-01T23:59:59.000Z

    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.

  3. Chemical heat pump

    DOE Patents [OSTI]

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

    1984-01-01T23:59:59.000Z

    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.

  4. Chemical heat pump

    DOE Patents [OSTI]

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

    1981-01-01T23:59:59.000Z

    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.

  5. How Do Variations in Heat Islands in Space and Time Influence HoHow Do Variations in Heat Islands in Space and Time Influence Household Water Use?usehold Water Use? Rimjhim Aggarwal1, Subhrajit Guhathakurta1,2, Susanne Grossman-Clarke1, and Vasudha Lathey

    E-Print Network [OSTI]

    Hall, Sharon J.

    to estimate the relation between heat islands and water consumption, after adjusting for the effect consumption has remained stable over these years. To use panel data techniques to control for the unobserved consumption in Phoenix. RESULTS The heat island has expanded spatially over the study period, and also

  6. Time sequenced heating of multiple layers in a hydrocarbon containing formation

    DOE Patents [OSTI]

    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

    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.

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

    E-Print Network [OSTI]

    Socala, Jolanta

    2011-01-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Jolanta Socala; Wojciech M. Zajaczkowski

    2011-03-21T23:59:59.000Z

    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.

  9. 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)

    NONE

    1997-07-01T23:59:59.000Z

    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.

  10. Making the Case For Safe Storage of Used Nuclear Fuel For Extended Periods of Time: Combining Near-Term Experiments and Analyses with Longer-Term Confirmatory Demonstrations

    SciTech Connect (OSTI)

    Sorenson, Ken B.; Hanson, Brady D.

    2013-08-25T23:59:59.000Z

    The need for extended storage of used nuclear fuel is increasing globally as disposition schedules for used fuel are pushed further into the future. This is creating a situation where dry storage of used fuel may need to be extended beyond normal regulatory licensing periods. While it is generally accepted that used fuel in dry storage will remain in a safe condition, there is little data that demonstrate used fuel performance in dry storage environments for long periods of time. This is especially true for high burnup used fuel.

  11. Comparing ultrafast surface and bulk heating using time-resolved electron diffraction

    SciTech Connect (OSTI)

    Streubühr, C.; Kalus, A.; Zhou, P., E-mail: ping.zhou@uni-due.de; Kammler, M.; Linde, D. von der [Faculty of Physics, University of Duisburg-Essen, Duisburg 47057 (Germany); Ligges, M.; Hanisch-Blicharski, A.; Bovensiepen, U.; Horn-von Hoegen, M. [Faculty of Physics, University of Duisburg-Essen, Duisburg 47057 (Germany); CENIDE, Centre for Nano Integration Duisburg Essen, Duisburg 47057 (Germany)

    2014-04-21T23:59:59.000Z

    From measurements of the transient Debye-Waller effect in Bismuth, we determine the buildup time of the random atomic motion resulting from the electronic relaxation after short pulse laser excitation. The surface sensitive reflection high energy electron diffraction and transmission electron diffraction yield a time constant of about 12 ps and 3 ps, respectively. The different energy transfer rates indicate relatively weak coupling between bulk and surface vibrational modes.

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

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    Assisted Heat Pump Heating System with Latent Heat Storage. In this system, solar energy is the major heat source for a heat pump, and the supplementary heat source is soil. The disagreement in time between the space heat load and heat collected by solar...

  13. Three-dimensional numerical simulations of heat transfer in an annular fuel channel with periodic spacer ribs under a fully developed turbulent flow

    SciTech Connect (OSTI)

    Takase, Kazuyuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)

    1997-05-01T23:59:59.000Z

    Thermal-hydraulic characteristics in a spacer-ribbed annular fuel channel for high-temperature gas-cooled reactors were analyzed numerically by three-dimensional computations under a fully developed turbulent flow. The two-equation {kappa}-{epsilon} turbulence model was applied in the present turbulent analysis, and the turbulence model constants for eddy viscosity and the turbulent Prandtl number were improved from the previous standard values to increase the accuracy of numerical simulations. Consequently, heat transfer coefficients and friction factors in the spacer-ribbed fuel channel were predicted with sufficient accuracy in the range of Reynolds number >3,000. It was clarified quantitatively that the main mechanism for heat transfer augmentation in the spacer-ribbed fuel channel was a combined effect of the turbulence promoter effect by the spacer rib and the velocity acceleration effect by a reduction in the channel cross section.

  14. Local Load Analysis with Periodic Time Series and Temperature Adjustment Marcelo Espinoza, Bart De Moor Caroline Joye Ronnie Belmans

    E-Print Network [OSTI]

    Time Series, Load Profiles, Temperature Sensitivity, Weather Adjustment 1 Introduction The quantitative, it is required to use indirect techniques to assess the type of demand they face [10, 11] in order to support their long-term investment planning. In this context, categories of residential, business and in- dustrial

  15. 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.

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

    SciTech Connect (OSTI)

    Samuelsen, Scott; Brouwer, Jack

    2013-08-31T23:59:59.000Z

    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.

  17. New Results on the Time lags of the Quasi-Periodic Oscillations in the Low-mass X-ray Binary 4U 1636--53

    E-Print Network [OSTI]

    de Avellar, Marcio G B; Altamirano, Diego; Sanna, Andrea; Zhang, Guobao

    2015-01-01T23:59:59.000Z

    We present an analysis of the energy and frequency dependence of the Fourier time lags of the hectoHertz quasi-periodic oscillations (QPOs) and of the QPOs at the frequency at which the power density spectrum shows a break in the neutron-star low-mass X-ray binary 4U 1636-53, using a large data set obtained with the Rossi X-ray Timing Explorer. We found that: (i) For the break frequency QPO: for low frequencies, in general the time lag is positive, but it is decreasing with increasing frequency, reaching zero lag at 20 Hz. Between 20 and 35 Hz there is a small fluctuation around zero, from where the time lags become positive again and increase slightly above zero up to 65 Hz. (ii) For the hHz QPO: we see that when the frequency is 100 Hz the time lag is negative, but it increases to zero already at 110 Hz, being consistent with this value up to 130 Hz from where it increases to 0.5 msec at around 140 Hz. From 140 Hz the time lag decreases sharply, being strongly negative for hHz greater than 220 Hz. We compar...

  18. 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]

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

    2014-01-01T23:59:59.000Z

    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).

  19. Is Your Dairy Management Program Ready for The Summer Heat

    E-Print Network [OSTI]

    Stokes, Sandra R.

    2000-04-25T23:59:59.000Z

    - eral supplementation during periods of heat stress include: ? 1.5 to 1.6 percent potassium ? .45 to .60 percent sodium ? .35 to .40 percent magnesium Feeding management. Feed intake is the key to lactation performance at any time of the year... Water Availability. Water is indisputably the most important nutrient for lactation, and it becomes even more essential when cows are under heat stress. In the lactating cow, water is necessary both for dissipating excess body heat and as a large...

  20. Wafer heating mechanisms in a molecular gas, inductively coupled plasma: in situ, real time wafer surface measurements and three-dimensional thermal modeling

    SciTech Connect (OSTI)

    Titus, M. J.; Graves, D. B. [Department of Chemical Engineering, University of California, Berkeley, California 94720 (United States)

    2008-09-15T23:59:59.000Z

    The authors report measurements and modeling of wafer heating mechanisms in an Ar/O{sub 2} inductively coupled plasma (ICP). The authors employed a commercially available on-wafer sensor system (PlasmaTemp developed by KLA-Tencor) consisting of an on-board electronics module housing battery power and data storage with 30 temperature sensors embedded onto the wafer at different radial positions. This system allows for real time, in situ wafer temperature measurements. Wafer heating mechanisms were investigated by combining temperature measurements from the PlasmaTemp sensor wafer with a three-dimensional heat transfer model of the wafer and a model of the ICP. Comparisons between pure Ar and Ar/O{sub 2} discharges demonstrated that two additional wafer heating mechanisms can be important in molecular gas plasmas compared to atomic gas discharges. The two mechanisms are heating from the gas phase and O-atom surface recombination. These mechanisms were shown to contribute as much as 60% to wafer heating under conditions of low bias power. This study demonstrated how the 'on-wafer' temperature sensor not only yields a temperature profile distribution across the wafer, but can be used to help determine plasma characteristics, such as ion flux profiles or plasma processing temperatures.

  1. Performance of Horizontal Field Earth-Coupled Heat Pumps 

    E-Print Network [OSTI]

    Abbott, C. A.

    1986-01-01T23:59:59.000Z

    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...

  2. Performance of Horizontal Field Earth-Coupled Heat Pumps

    E-Print Network [OSTI]

    Abbott, C. A.

    1986-01-01T23:59:59.000Z

    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...

  3. Plasma heating in a variable magnetic field

    SciTech Connect (OSTI)

    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

    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.

  4. 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]

    Ozturk, Burak

    2009-05-15T23:59:59.000Z

    .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...

  5. Periodic Variations in the Residual Eclipse Flux and Eclipse Timings of Asynchronous Polar V1432 Aql: Evidence of a Shifting Threading Region

    E-Print Network [OSTI]

    Littlefield, Colin; Cain, Ryan; Mumme, Raymond; Magno, Katrina C; Corpuz, Taylor; Sandefur, Davis; Boyd, David; Cook, Michael; Ulowetz, Joseph

    2014-01-01T23:59:59.000Z

    We report the results of a twenty-five-month photometric campaign studying V1432 Aql, the only known eclipsing, asynchronous polar. Our data show that both the residual eclipse flux and eclipse O-C timings vary strongly as a function of the spin-orbit beat period. Relying upon a new model of the system, we show that cyclical changes in the location of the threading region along the ballistic trajectory of the accretion stream could produce both effects. This model predicts that the threading radius is variable, in contrast to previous studies which have assumed a constant threading radius. Additionally, we identify a very strong photometric maximum which is only visible for half of the beat cycle. The exact cause of this maximum is unclear, but we consider the possibility that it is the optical counterpart of the third accreting polecap proposed by Rana et al. (2005). Finally, the rate of change of the white dwarf's spin period is consistent with it being proportional to the difference between the spin and or...

  6. Time evolution of the ion temperature in the T-10 tokamak during simultaneous pellet injection and electron-cyclotron resonance heating

    SciTech Connect (OSTI)

    Gott, Yu. V.; Pavlov, Yu. D.; Borshchagovskii, A. A.; Gorbunov, E. P.; Dremin, M. M.; Ishevskii, O. V.; Kislov, A. Ya.; Krylov, S. V.; Matveev, V. V.; Prut, V. V.; Roi, I. N.; Ryzhakov, D. V.; Skosyrev, Yu. V.; Trukhin, V. M.; Khramenkov, A. V.; Chistyakov, V. V. [Russian Research Centre Kurchatov Institute (Russian Federation)

    2007-12-15T23:59:59.000Z

    Results are presented from studies of the time evolution of the ion temperature in the T-10 tokamak in the course of injection of several (up to five) deuterium pellets into a deuterium plasma the electron component of which is heated at the second harmonic of the electron gyrofrequency. It is shown that, at an electron cyclotron heating power of 900 kW, the injection of five pellets is accompanied by an increase in the ion temperature to 1200 keV, which is a record value for T-10. It is noted that energy exchange between the electron and ion components in these experiments is a purely classical, Coulomb process.

  7. 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:...

  8. Statistical Time-Resolved Spectroscopy: A higher fraction of short-period binaries for metal-rich F-type dwarfs in SDSS

    E-Print Network [OSTI]

    Hettinger, T; Strader, J; Bickerton, S J; Beers, T C

    2015-01-01T23:59:59.000Z

    Stellar multiplicity lies at the heart of many problems in modern astrophysics, including the physics of star formation, the observational properties of unresolved stellar populations, and the rates of interacting binaries such as cataclysmic variables, X-ray binaries, and Type Ia supernovae. However, little is known about the stellar multiplicity of field stars in the Milky Way, in particular about the differences in the multiplicity characteristics between metal-rich disk stars and metal-poor halo stars. In this study we perform a statistical analysis of ~15,000 F-type dwarf stars in the Milky Way through time-resolved spectroscopy with the sub-exposures archived in the Sloan Digital Sky Survey. We obtain absolute radial velocity measurements through template cross-correlation of individual sub-exposures with temporal baselines varying from minutes to years. These sparsely sampled radial velocity curves are analyzed using Markov chain Monte Carlo techniques to constrain the very short-period binary fraction...

  9. Optimization of Heat Exchanger Cleaning 

    E-Print Network [OSTI]

    Siegell, J. H.

    1986-01-01T23:59:59.000Z

    The performance of heat integration systems is quantified in terms of the amount of heat that is recovered. This decreases with time due to increased fouling of the heat exchange surface. Using the "Total Fouling Related Expenses (TFRE)" approach...

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

    SciTech Connect (OSTI)

    Huggins, J.

    1998-10-01T23:59:59.000Z

    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.

  11. 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)

    Palmer, T; Elmer, J; Babu, S

    2003-10-29T23:59:59.000Z

    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.

  12. HEATING6 verification

    SciTech Connect (OSTI)

    Bryan, C.B.; Childs, K.W.; Giles, G.E.

    1986-12-01T23:59:59.000Z

    The HEATING series of general purpose, finite-difference, conduction heat transfer codes have been in use for many years. During this time the codes have been used extensively, and a general confidence has been developed in regard to their accuracy. However, there has never been a formal verification in a published, citable document. This report documents just such a verification study for the latest code in the HEATING series, HEATING6. This study confirms that HEATING6 is capable of producing accurate results for a large class of heat transfer problems. 11 refs., 170 figs., 82 tabs.

  13. 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)

    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

    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.

  14. Molecular heat pump

    E-Print Network [OSTI]

    Dvira Segal; Abraham Nitzan

    2005-10-11T23:59:59.000Z

    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.

  15. Regular simplex and periodic billiard orbit

    E-Print Network [OSTI]

    Bedaride, Nicolas

    2011-01-01T23:59:59.000Z

    We consider billiard inside regular simplex of $\\mathbb{R}^n$. We show the existence of two periodic trajectories. One of period $n+1$ which passes one time by each face and one of period $2n$ which passes $n$ times through one face and one time through each other face. In both cases we obtain exact coordinates for the periodic points.

  16. Effects of variations in holding time, curing temperature, and treatment period on selected physical properties of concrete made with type III cement and steam cured at atmospheric pressure

    E-Print Network [OSTI]

    Burleson, Kenneth Stewart

    1958-01-01T23:59:59.000Z

    pigures 7 through 15) and their cenbinad effects on the a~receive strengths of stem cured concrete are presente4 in Table 1. TABLI 1. Cenhinations of HoMag Tines ~ Curing Tenperatures, aad Optima Treatssnt Periods, and Their Conhined gffects.... The optima holding tine for tenperatures of 140, 165 and 165 F to obtain ths aaxiaun nodulus of elasticity for a treatasnt period of 16 hours is indicated in Figures 42 through 45. k treatnent peried of 16 hours was used in plotting these ourves, because...

  17. Matrix tablets are drug delivery devices that release a water-soluble drug over an extended period of time. Such matrix tablets are formulated from mixtures of drug, polymer, and excipient

    E-Print Network [OSTI]

    Hinow, Peter

    Summary Matrix tablets are drug delivery devices that release a water-soluble drug over an extended period of time. Such matrix tablets are formulated from mixtures of drug, polymer, and excipient powders variation in the drug release profile of the tablet. While fabrication of experimental tablets

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

    E-Print Network [OSTI]

    Magdalena Pelc

    2007-11-26T23:59:59.000Z

    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.

  19. Position Title: Community Service-Learning Student Mentor Part-time Casual position for the period of August 26, 2013 to April 4, 2014

    E-Print Network [OSTI]

    Peak, Derek

    Position Title: Community Service-Learning Student Mentor Terms: Part-time Casual position Reporting to the Engaged Learning Coordinator, and working collaboratively with another CSL Student Mentor, the CSL Student Mentor will be responsible for the facilitation of the STM Service & Justice Project (SJP

  20. Version control Version control is a powerful tool for many kinds of work done over a period of time, including writing

    E-Print Network [OSTI]

    Alavi, Ali

    is a good idea are: · efficient development practices. It is very easy to try things out and experiment of time, including writing papers and theses as well as writing code. This session gives a introduction communication via a central server which stores the repository whereas a DVCS is completely distributed and each

  1. Hot Water Heating System Operation and Energy Conservation 

    E-Print Network [OSTI]

    Shao, Z.; Chen, H.; Wei, P.

    2006-01-01T23:59:59.000Z

    heating period, and temperature-flow adjustment with frequency control. The study shows the most energy efficient operating method is a variable flow heating system, which should be popularized to the heating field....

  2. Modelling and simulation of a heat pump for simultaneous heating and cooling

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    production and space cooling at the same time. An answer to a dual energy demand is the heat pump, sinceModelling and simulation of a heat pump for simultaneous heating and cooling Paul Byrne1 *, Jacques-012-0089-0 #12;1. ABSTRACT The heat pump for simultaneous heating and cooling (HPS) carries out space heating

  3. A highly specific test for periodicity

    E-Print Network [OSTI]

    Ansmann, Gerrit

    2015-01-01T23:59:59.000Z

    We present a method that allows to distinguish between nearly periodic and strictly periodic time series. To this purpose, we employ a conservative criterion for periodicity, namely that the time series can be interpolated by a periodic function whose local extrema are also present in the time series. Our method is intended for the analysis of time series generated by deterministic dynamical systems, where it can help telling periodic dynamics from chaotic or transient ones. We empirically investigate our method's performance and compare it to an approach based on marker events (or Poincar\\'e sections). We demonstrate that our method is capable of detecting small deviations from periodicity and outperforms the marker-event-based approach in typical situations. Our method requires no adjustment of parameters to the individual time series, yields the period length with a precision that exceeds the sampling rate, and its run time grows asymptotically linear with the length of the time series.

  4. Photovoltaic roof heat flux

    E-Print Network [OSTI]

    Samady, Mezhgan Frishta

    2011-01-01T23:59:59.000Z

    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

  5. EnergyPlus Run Time Analysis

    E-Print Network [OSTI]

    Hong, Tianzhen

    2009-01-01T23:59:59.000Z

    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

  6. Heat Pipe Technology for Energy Conservation in the Process Industry 

    E-Print Network [OSTI]

    Price, B. L. Jr.

    1985-01-01T23:59:59.000Z

    Many applications for heat pipe technology have emerged in the relatively short time this technology has been known. Heat pipes incorporated in heat exchangers have been used in tens of thousands of successful heat recovery systems. These systems...

  7. Temperature profile of the infrared image Heat exchange between

    E-Print Network [OSTI]

    Jaehne, Bernd

    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

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. Optimal Checkpointing Period: Time vs. Energy

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    is focusing on the characteris- tics, features, and challenges of High Performance Computing (HPC) systems-purpose error recovery technique in high performance computing is checkpoint and rollback recovery

  14. Storm Water Analytical Period

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

    Protection Obeying Environmental Laws Individual Permit Storm Water Analytical Period Storm Water Analytical Period The Individual Permit authorizes the discharge of storm...

  15. Heat transfer at the mold-metal interface in permanent mold casting of aluminum alloys project. Annual project status report for the period October 1, 1997 to September 30, 1998

    SciTech Connect (OSTI)

    Pehlke, R.D.; Hao, S.W.

    1998-09-30T23:59:59.000Z

    In the first year of this three-year project, substantial progress has been achieved. This project on heat transfer coefficients in metal permanent mold casting is being conducted in three areas. They are the theoretical study at the University of Michigan, the experimental investigations of squeeze casting and semi-solid casting at CMI-Tech Center, and the experimental investigation of low pressure permanent mold casting at Amcast Automotive. U-M did an initial geometry which was defined for ProCAST to solve, and then a geometry half the size was defined and solved using the same boundary conditions. A conceptual mold geometry was examined and is represented as an axisymmetric element.Furthermore, the influences of the localized heat transfer coefficients on the casting process were carefully studied. The HTC Evaluator has been proposed and initially developed by the U-M team. The Reference and the Database Modules of the HTC Evaluator have been developed, and extensively tested. A series of technical barriers have been cited and potential solutions have been surveyed. At the CMI-Tech Center, the Kistler direct cavity pressure measurement system has been purchased and tested. The calibrations has been evaluated. The probe is capable of sensing a light finger pressure. The experimental mold has been designed and modified. The experimental mold has been designed and modified. The first experiment is scheduled for October 14, 1998. The geometry of the experimental hockey-puck casting has been given to the U-M team for numerical analysis.

  16. Heat transport and weakening of atmospheric stability induced by mesoscale flows

    E-Print Network [OSTI]

    Pielke, Roger A.

    Heat transport and weakening of atmospheric stability induced by mesoscale flows G. A. Dalu boundary layer (CBL) is transported upward into the midtroposphere by mesoscale flows, and how the air, and diffusion, associated with the mesoscale flow, is more clearly shown when the forcing is periodic in time

  17. Heating system

    SciTech Connect (OSTI)

    Nishman, P.J.

    1983-03-08T23:59:59.000Z

    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.

  18. Alternative cooling resource for removing the residual heat of reactor

    SciTech Connect (OSTI)

    Park, H. C.; Lee, J. H.; Lee, D. S.; Jung, C. Y.; Choi, K. Y. [Korea Hydro and Nuclear Power Co., Ltd., 260 Naa-ri Yangnam-myeon Gyeongju-si, Gyeonasangbuk-do, 780-815 (Korea, Republic of)

    2012-07-01T23:59:59.000Z

    The Recirculated Cooling Water (RCW) system of a Candu reactor is a closed cooling system which delivers demineralized water to coolers and components in the Service Building, the Reactor Building, and the Turbine Building and the recirculated cooling water is designed to be cooled by the Raw Service Water (RSW). During the period of scheduled outage, the RCW system provides cooling water to the heat exchangers of the Shutdown Cooling System (SDCS) in order to remove the residual heat of the reactor, so the RCW heat exchangers have to operate at all times. This makes it very hard to replace the inlet and outlet valves of the RCW heat exchangers because the replacement work requires the isolation of the RCW. A task force was formed to prepare a plan to substitute the recirculated water with the chilled water system in order to cool the SDCS heat exchangers. A verification test conducted in 2007 proved that alternative cooling was possible for the removal of the residual heat of the reactor and in 2008 the replacement of inlet and outlet valves of the RCW heat exchangers for both Wolsong unit 3 and 4 were successfully completed. (authors)

  19. An Unexpected Heat Wave | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    means that the transport of heat becomes incoherent and difficult to predict or control. In this study, heat transport through superlattices (SL) made up of periodic stacks...

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

    SciTech Connect (OSTI)

    None

    2010-09-01T23:59:59.000Z

    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.

  1. Viscoelastic Models of Tidally Heated Exomoons

    E-Print Network [OSTI]

    Dobos, Vera

    2015-01-01T23:59:59.000Z

    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...

  2. 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)

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

    2011-01-11T23:59:59.000Z

    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.

  3. 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)

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

    2011-01-11T23:59:59.000Z

    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) inmore »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.« less

  4. Corrosive resistant heat exchanger

    DOE Patents [OSTI]

    Richlen, Scott L. (Annandale, VA)

    1989-01-01T23:59:59.000Z

    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.

  5. Self-heating in kinematically complex magnetohydrodynamic flows

    E-Print Network [OSTI]

    Osmanov, Zaza; Poedts, Stefaan

    2012-01-01T23:59:59.000Z

    The non-modal self-heating mechanism driven by the velocity shear in kinematically complex magnetohydrodynamic (MHD) plasma flows is considered. The study is based on the full set of MHD equations including dissipative terms. The equations are linearized and unstable modes in the flow are looked for. Two different cases are specified and studied: (a) the instability related to an exponential evolution of the wave vector; and (b) the parametric instability, which takes place when the components of the wave vector evolve in time periodically. By examining the dissipative terms, it is shown that the self-heating rate provided by viscous damping is of the same order of magnitude as that due to the magnetic resistivity. It is found that the heating efficiency of the exponential instability is higher than that of the parametric instability.

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

    SciTech Connect (OSTI)

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

    2011-01-11T23:59:59.000Z

    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.

  7. Heat collector

    DOE Patents [OSTI]

    Merrigan, Michael A. (Santa Cruz, NM)

    1984-01-01T23:59:59.000Z

    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.

  8. Heat collector

    DOE Patents [OSTI]

    Merrigan, M.A.

    1981-06-29T23:59:59.000Z

    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.

  9. Impacts of Water Quality on Residential Water Heating Equipment

    SciTech Connect (OSTI)

    Widder, Sarah H.; Baechler, Michael C.

    2013-11-01T23:59:59.000Z

    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.

  10. Dynamics of global ocean heat transport variability

    E-Print Network [OSTI]

    Jayne, Steven Robert

    1999-01-01T23:59:59.000Z

    A state-of-the-art, high-resolution ocean general circulation model is used to estimate the time-dependent global ocean heat transport and investigate its dynamics. The north-south heat transport is the prime manifestation ...

  11. Optimization of the Heating System Operation 

    E-Print Network [OSTI]

    Xu, W.; Mao, S.

    2006-01-01T23:59:59.000Z

    A new regulation method of the heating system is presented, which is based on the variation of outdoor temperature, to improve the economical efficiency and the timing regulation of the heating system. A function is put forward between the energy...

  12. In situ laser heating and radial synchrotron X-ray diffraction in a diamond anvil cell

    E-Print Network [OSTI]

    Kunz, Martin; Caldwell, Wendel A.; Miyagi, Lowell; Wenk, Hans-Rudolf

    2007-01-01T23:59:59.000Z

    c) Inverse pole figure during heating. Pressure is 27.8 GPa.2006): Double-sided laser heating system at HPCAT for in-taken during a 5 minute heating period. Pressure is 27.8

  13. 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)

    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

    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.

  14. Intrinsically irreversible heat engine

    DOE Patents [OSTI]

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

    1984-01-01T23:59:59.000Z

    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.

  15. Intrinsically irreversible heat engine

    DOE Patents [OSTI]

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

    1984-12-25T23:59:59.000Z

    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.

  16. Intrinsically irreversible heat engine

    DOE Patents [OSTI]

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

    1984-01-01T23:59:59.000Z

    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.

  17. Industrial and Commercial Heat Pump Applications in the United States 

    E-Print Network [OSTI]

    Niess, R. C.

    1986-01-01T23:59:59.000Z

    The energy crisis of 1973 accelerated the development of large-scale heat pumps in the United States. Since that time, the commercial, institutional, and industrial applications of heat pumps for waste heat recovery have expanded. This paper reviews...

  18. Heating System Specification Specification of Heating System

    E-Print Network [OSTI]

    Day, Nancy

    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

  19. Mass Save- HEAT Loan Program

    Broader source: Energy.gov [DOE]

    Note: For a limited time, expanded HEAT loan offerings are available. These are being funded by a $3.8 million grant from the U.S. Department of Energy.

  20. HEAT OF HYDRATION OF SALTSTONE MIXES-MEASUREMENT BY ISOTHERMAL CALORIMETRY

    SciTech Connect (OSTI)

    Harbour, J; Vickie Williams, V; Tommy Edwards, T

    2007-07-02T23:59:59.000Z

    This report provides initial results on the measurement of heat of hydration of Saltstone mixes using isothermal calorimetry. The results were obtained using a recently purchased TAM Air Model 3116 Isothermal Conduction Calorimeter. Heat of hydration is an important property of Saltstone mixes. Greater amounts of heat will increase the temperature of the curing mix in the vaults and limit the processing rate. The heat of hydration also reflects the extent of the hydraulic reactions that turn the fluid mixture into a ''stone like'' solid and consequently impacts performance properties such as permeability. Determining which factors control these reactions, as monitored by the heat of hydration, is an important goal of the variability study. Experiments with mixes of portland cement in water demonstrated that the heats measured by this technique over a seven day period match very well with the literature values of (1) seven day heats of hydration using the standard test method for heat of hydration of hydraulic cement, ASTM C 186-05 and (2) heats of hydration measured using isothermal calorimetry. The heats of hydration of portland cement or blast furnace slag in a Modular Caustic Side Solvent Extraction Unit (MCU) simulant revealed that if the cure temperature is maintained at 25 C, the amount of heat released over a seven day period is roughly 62% less than the heat released by portland cement in water. Furthermore, both the blast furnace slag and the portland cement were found to be equivalent in heat production over the seven day period in MCU. This equivalency is due to the activation of the slag by the greater than 1 Molar free hydroxide ion concentration in the simulant. Results using premix (a blend of 10% cement, 45% blast furnace slag, and 45% fly ash) in MCU, Deliquification, Dissolution and Adjustment (DDA) and Salt Waste Processing Facility (SWPF) simulants reveal that the fly ash had not significantly reacted (undergone hydration reactions) after seven days (most likely less than 5%). There were clear differences in the amount of heat released and the peak times of heat release for the three different simulants. It turns out that SWPF simulant mixes give off greater heat than does MCU and DDA simulant mixes. The temperature dependence of the heat of hydration was measured by carrying out these measurements at 25, 40 and 55 C. In general, the peak times shifted to shorter times as the isothermal temperature increased and the amount of heat released was independent of temperature for DDA and MCU but slightly higher at higher temperatures for SWPF. The goal of this study is to apply this technique to the measurement of the heat of hydration of mixes that will be made as part of the variability study. It is important to understand which variables will impact (and to what extent) the amount of heat generated and the peak times for the heat release. Those variables that can be controlled can then be tuned to adjust the heat of hydration as long as the other properties are still acceptable. The first application of heat of hydration measurements to the variability study was completed and the results presented in this report. These measurements were made using Phase VI mixes (SWPF simulants) following a statistical design that included variation in the compositional and operational variables. Variation in both the amount of heat released and the peak times for the heat release were observed. The measured ranges were 23 Joules per gram of premix for the heat release and 23 hours for the peak time of heat release at 25 C. Linear models with high R{sup 2} values and no statistical evidence for lack of fit were developed that relate the amount of heat release and the peak time for heat release for the Phase VI mixes to certain variables. The amount of heat released was a function of the aluminate and portland cement concentrations as well as the temperature of mixing. The peak time for heat release was a function of aluminate, portland cement and total nitrate plus nitrite concentrations. A comparison was made of the mea

  1. MEASUREMENT OF SPECIFIC HEAT CAPACITY OF SALTSTONE

    SciTech Connect (OSTI)

    Harbour, J; Vickie Williams, V

    2008-09-29T23:59:59.000Z

    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

  2. Study on the heat transfer of heat exchangers for the Stirling Engine

    SciTech Connect (OSTI)

    Kanzaka, M. (Nagasaki Research and Development Center (JP)); Iwabuchi, M. (Advanced Technology Research Center, Mitsubishi Heavy Industries, Ltd. (JP))

    1991-01-01T23:59:59.000Z

    This paper reports that heat-transfer characteristics in heated tubes under periodically reversing flow conditions have been investigated experimentally using a test apparatus that simulates the heat exchangers for the actual Sterling engine. It was shown that the heat-transfer characteristics under these conditions were greatly affected by the piston phase-angle difference that generates the reversing flow of the working gas, and this phenomenon was proper to the heat transfer under the periodically reversing flow and was different from conventional heat transfer in steady flow. The experimental correlation considering the influence of the piston phase-angle difference for the heat-transfer coefficient has been induced by the use of the working gas velocity evaluated from the Schmidt cycle model which is one of the ideal Sterling cycles.

  3. Overshooting by differential heating

    E-Print Network [OSTI]

    Andrássy, R

    2015-01-01T23:59:59.000Z

    On the long nuclear time scale of stellar main-sequence evolution, even weak mixing processes can become relevant for redistributing chemical species in a star. We investigate a process of "differential heating," which occurs when a temperature fluctuation propagates by radiative diffusion from the boundary of a convection zone into the adjacent radiative zone. The resulting perturbation of the hydrostatic equilibrium causes a flow that extends some distance from the convection zone. We study a simplified differential-heating problem with a static temperature fluctuation imposed on a solid boundary. The astrophysically relevant limit of a high Reynolds number and a low P\\'eclet number (high thermal diffusivity) turns out to be interestingly non-intuitive. We derive a set of scaling relations for the stationary differential heating flow. A numerical method adapted to a high dynamic range in flow amplitude needed to detect weak flows is presented. Our two-dimensional simulations show that the flow reaches a sta...

  4. Genealogy of periodic trajectories

    SciTech Connect (OSTI)

    de Adguiar, M.A.M.; Maldta, C.P.; de Passos, E.J.V.

    1986-05-20T23:59:59.000Z

    The periodic solutions of non-integrable classical Hamiltonian systems with two degrees of freedom are numerically investigated. Curves of periodic families are given in plots of energy vs. period. Results are presented for this Hamiltonian: H = 1/2(p/sub x//sup 2/ + p/sub y//sup 2/) + 1/2 x/sup 2/ + 3/2 y/sup 2/ - x/sup 2/y + 1/12 x/sup 4/. Properties of the families of curves are pointed out. (LEW)

  5. Fourier series and periodicity

    E-Print Network [OSTI]

    Donal F. Connon

    2014-12-07T23:59:59.000Z

    A large number of the classical texts dealing with Fourier series more or less state that the hypothesis of periodicity is required for pointwise convergence. In this paper, we highlight the fact that this condition is not necessary.

  6. Heat pump system

    DOE Patents [OSTI]

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

    1982-01-01T23:59:59.000Z

    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.

  7. Geothermal heating

    SciTech Connect (OSTI)

    Aureille, M.

    1982-01-01T23:59:59.000Z

    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.

  8. Water and Space Heating Heat Pumps 

    E-Print Network [OSTI]

    Kessler, A. F.

    1985-01-01T23:59:59.000Z

    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...

  9. Water and Space Heating Heat Pumps

    E-Print Network [OSTI]

    Kessler, A. F.

    1985-01-01T23:59:59.000Z

    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...

  10. Industrial Waste Heat Recovery Using Heat Pipes 

    E-Print Network [OSTI]

    Ruch, M. A.

    1981-01-01T23:59:59.000Z

    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...

  11. Cab Heating and Cooling

    SciTech Connect (OSTI)

    Damman, Dennis

    2005-10-31T23:59:59.000Z

    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.

  12. Heating 7. 2 user's manual

    SciTech Connect (OSTI)

    Childs, K.W.

    1993-02-01T23:59:59.000Z

    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.

  13. Heating systems for heating subsurface formations

    DOE Patents [OSTI]

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

    2011-04-26T23:59:59.000Z

    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.

  14. CONDUCTION HEAT TRANSFER Dr. Ruhul Amin Fall 2011

    E-Print Network [OSTI]

    Dyer, Bill

    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

  15. Helium Refrigerator Design for Pulsed Heat Load in Tokamaks

    SciTech Connect (OSTI)

    Kuendig, A.; Schoenfeld, H. [Linde Kryotechnik AG, Dattlikonerstrasse 5, CH-8422 Pfungen (Switzerland)

    2006-04-27T23:59:59.000Z

    Nuclear fusion reactors of the Tokamak type will be operated in a pulsed mode requiring the helium refrigerator to remove periodically large heat loads in time steps of approximately one hour. What are the necessary steps for a refrigerator to cope with such load variations?A series of numerical simulations has been performed indicating the possibility of an active refrigerator control with low exergetic losses. A basic comparison is made between the largest existing refrigerator sizes and the size required to service for example the ITER requirements.

  16. Infrared Thermography applied to measurement of Heat transfer coefficient of water in a pipe heated by Joule effect

    E-Print Network [OSTI]

    Boyer, Edmond

    Infrared Thermography applied to measurement of Heat transfer coefficient of water in a pipe heated has been developed based on periodic excitation by Joule effect and infrared thermography measurement. It has been applied to measure heat transfer coefficients of water flowing in a round tube

  17. Dead heat

    SciTech Connect (OSTI)

    Oppenheimer, M.; Boyle, R.H.

    1990-01-01T23:59:59.000Z

    This paper reports on the prospect of global warming. This paper proposes a workable solution, and a road map for getting there. The author explains how we became addicted to fossil fuels and evokes a bleak picture should this dependence continue. But the book also explores how industry can become a vehicle for solving, instead of precipitating, the global environmental crisis. The decoupling of energy from pollution can be accomplished without sacrificing prosperity by powering the economy with solar energy. Dead Heat takes us step by step to a greenhouse-friendly world fueled only by the sun.

  18. PreHeat: Controlling Home Heating Using Occupancy Prediction

    E-Print Network [OSTI]

    Krumm, John

    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

  19. Dual source heat pump

    DOE Patents [OSTI]

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

    1982-01-01T23:59:59.000Z

    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.

  20. Segmented heat exchanger

    DOE Patents [OSTI]

    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

    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.

  1. Analysis of the cryogenic system behavior for pulsed heat load in EAST

    SciTech Connect (OSTI)

    Hu, L. B.; Zhuang, M.; Zhou, Z. W.; Xia, G. H. [Cryogenic Engineering Division, Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Shushanhu Road 350, Hefei, Anhui 230031 (China)

    2014-01-29T23:59:59.000Z

    EAST is the first full superconducting fusion device. The plasma is confined by the magnetic fields generated from a large set of superconducting magnets which are made of cable in-conduit conductor (CICC). In operation, these magnets suffer heat loads from thermal and nuclear radiation from the surrounding components and plasma as well as the eddy currents and the AC losses generated within the magnets, together with the heat conduction through supports and the resistive heat generated at the current lead transiting to room temperature. The cryogenic system of our EAST consists of a 2kW/4K helium refrigerator and a distribution system for the cooling of poloidal field (PF) and toroidal field (TF) coils, structures, thermal shields, buslines and current leads. Pulsed heat load is the main difference between the cryogenic system of a full superconducting Tokamak system and other large scale cryogenic systems. The cryogenic system operates in a pulsed heat loads mode requiring the helium refrigerator to remove periodically large heat loads in time. At the same time, the cryogenic system parameters such as helium cooling superconducting magnets, helium refrigerator and helium distribution system are changing. In this paper, the variation range of the parameters of superconducting magnets and refrigerator has been analyzed in the typical plasma discharge mode. The control scheme for the pulsed loads characteristics of the cryogenic system has been proposed, the implementation of which helps to smooth the pulse loads and to improve the stability of the operation of the cryogenic system.

  2. Molecular mechanisms of the plant heat stress response

    SciTech Connect (OSTI)

    Qu, Ai-Li; Ding, Yan-Fei; Jiang, Qiong [China Jiliang University, Xueyuan Road 258, Hangzhou 310018 (China)] [China Jiliang University, Xueyuan Road 258, Hangzhou 310018 (China); Zhu, Cheng, E-mail: pzhch@cjlu.edu.cn [China Jiliang University, Xueyuan Road 258, Hangzhou 310018 (China)] [China Jiliang University, Xueyuan Road 258, Hangzhou 310018 (China)

    2013-03-08T23:59:59.000Z

    Highlights: ? This review elaborates the response networks of heat stress in plants. ? It elaborates proteins responding to heat stress in special physiological period. ? The proteins and pathways have formed a basic network of the heat stress response. ? Achievements of the various technologies are also combined. -- Abstract: High temperature has become a global concern, which seriously affects the growth and production of plants, particularly crops. Thus, the molecular mechanism of the heat stress response and breeding of heat-tolerant plants is necessary to protect food production and ensure crop safety. This review elaborates on the response networks of heat stress in plants, including the Hsf and Hsp response pathways, the response of ROS and the network of the hormones. In addition, the production of heat stress response elements during particular physiological periods of the plant is described. We also discuss the existing problems and future prospects concerning the molecular mechanisms of the heat stress response in plants.

  3. Optimization of Heat Exchanger Cleaning

    E-Print Network [OSTI]

    Siegell, J. H.

    yiven in equations (7) and (8) results in the TFRE curves shown in Figure 6. In performing the calculations to compare chemical and mechanical cleaning, it is important to remember to include the value of the 20 MBtu/Hr heat lost between... MBtu/hr/day 20 Data From Operating Unit 10 20 30 40 50 60 70 ...., ........ ...................... ~.... ---- Time (Days) Figure 4. Comparison of Models for Heat Recovery ~ecay to Simulated Operating Data. MECHANICAL CLEANING W 100 MBtu...

  4. Geothermal heat pumps for heating and cooling

    SciTech Connect (OSTI)

    Garg, S.C.

    1994-03-01T23:59:59.000Z

    Naval Facilities Engineering Service Center (NFESC) has been tasked by Naval Shore Facilities Energy Office to evaluate the NAS Patuxent River ground-source heat pump (GHP) installation. A large part of a building`s energy consumption consists of heating and air conditioning for occupant comfort. The space heating requirements are normally met by fossil-fuel-fired equipment or electric resistance heating. Cooling is provided by either air conditioners or heat pumps, both using electricity as an energy source.

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    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

  7. Original article Heat balance of a multistage spray-dryer

    E-Print Network [OSTI]

    Boyer, Edmond

    into account. From these data, the heat balance showed a dif- ference between inputs and outputs of 2.9% which may be interpreted as heat losses and probable errors. The specific heat consumption was close to 4 of the small flow rates of air used in both fluid beds. This specific heat consumption corresponds to 2.1 times

  8. DEVELOPMENT OF RASASASTRA IN MEDIEVAL PERIOD*

    E-Print Network [OSTI]

    Harishankar Sharma

    1984-01-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Kirol, L. D.

    1986-01-01T23:59:59.000Z

    Chemical heat pumps utilize working fluids which undergo reversible chemical changes. Mechanically driven reactive heat pump cycles or, alternatively, heat driven heat pumps in which either heat engine or heat pump working fluid is reactive...

  10. Multiple source heat pump

    DOE Patents [OSTI]

    Ecker, Amir L. (Duncanville, TX)

    1983-01-01T23:59:59.000Z

    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.

  11. HEAT TRANSFER IN STEADY-PERIODIC FLOWS OVER HEATED S. Yesilyurt, M. Ozcan, G. Goktug

    E-Print Network [OSTI]

    Yanikoglu, Berrin

    ; these two eddies are the well-known Karman vortex streets and as Re increases further they are very much) and Laake and Eckelmann (1989); similarly a group of authors studied vortex formation in flow around

  12. Tidal heating in multilayered terrestrial exoplanets

    SciTech Connect (OSTI)

    Henning, Wade G.; Hurford, Terry, E-mail: wade.g.henning@nasa.gov [NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States)

    2014-07-01T23:59:59.000Z

    The internal pattern and overall magnitude of tidal heating for spin-synchronous terrestrial exoplanets from 1 to 2.5 R{sub E} is investigated using a propagator matrix method for a variety of layer structures. Particular attention is paid to ice-silicate hybrid super-Earths, where a significant ice mantle is modeled to rest atop an iron-silicate core, and may or may not contain a liquid water ocean. We find multilayer modeling often increases tidal dissipation relative to a homogeneous model, across multiple orbital periods, due to the ability to include smaller volume low viscosity regions, and the added flexure allowed by liquid layers. Gradations in parameters with depth are explored, such as allowed by the Preliminary Earth Reference Model. For ice-silicate hybrid worlds, dramatically greater dissipation is possible beyond the case of a silicate mantle only, allowing non-negligible tidal activity to extend to greater orbital periods than previously predicted. Surface patterns of tidal heating are found to potentially be useful for distinguishing internal structure. The influence of ice mantle depth and water ocean size and position are shown for a range of forcing frequencies. Rates of orbital circularization are found to be 10-100 times faster than standard predictions for Earth-analog planets when interiors are moderately warmer than the modern Earth, as well as for a diverse range of ice-silicate hybrid super-Earths. Circularization rates are shown to be significantly longer for planets with layers equivalent to an ocean-free modern Earth, as well as for planets with high fractions of either ice or silicate melting.

  13. Climate, extreme heat, and electricity demand in California

    SciTech Connect (OSTI)

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

    2008-04-01T23:59:59.000Z

    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.

  14. 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...

  15. 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...

  16. Boise City Geothermal District Heating District Heating Low Temperatur...

    Open Energy Info (EERE)

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

  17. 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...

  18. 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,...

  19. 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...

  20. Northeast Home Heating Oil Reserve System Heating Oil, PIA Office...

    Energy Savers [EERE]

    Northeast Home Heating Oil Reserve System Heating Oil, PIA Office of Fossil Energy Headquaters Northeast Home Heating Oil Reserve System Heating Oil, PIA Office of Fossil Energy...

  1. Heat Pump for High School Heat Recovery 

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    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...

  2. Industrial Waste Heat Recovery Using Heat Pipes

    E-Print Network [OSTI]

    Ruch, M. A.

    1981-01-01T23:59:59.000Z

    -expanding variety of industrial processes. One notable application in recent years has been for combustion airs preheat of fired heaters in petroleum refineries and petrochemical plants. Another recent development has been a waste heat recovery boiler using heat...

  3. Absorption heat pump system

    DOE Patents [OSTI]

    Grossman, Gershon (Oak Ridge, TN)

    1984-01-01T23:59:59.000Z

    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.

  4. Absorption heat pump system

    DOE Patents [OSTI]

    Grossman, G.

    1982-06-16T23:59:59.000Z

    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.

  5. Locating Heat Recovery Opportunities 

    E-Print Network [OSTI]

    Waterland, A. F.

    1981-01-01T23:59:59.000Z

    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...

  6. Locating Heat Recovery Opportunities

    E-Print Network [OSTI]

    Waterland, A. F.

    1981-01-01T23:59:59.000Z

    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...

  7. Photovoltaic roof heat flux

    E-Print Network [OSTI]

    Samady, Mezhgan Frishta

    2011-01-01T23:59:59.000Z

    transient the heat transfer model. T h i s required the roofto develop and calibrate heat transfer models to be able toE S station, the heat transfer models described i n sections

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

    SciTech Connect (OSTI)

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

    1998-03-01T23:59:59.000Z

    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.

  9. HEATING 7. 1 user's manual

    SciTech Connect (OSTI)

    Childs, K.W.

    1991-07-01T23:59:59.000Z

    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.

  10. Woven heat exchanger

    DOE Patents [OSTI]

    Piscitella, R.R.

    1984-07-16T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    1991-10-01T23:59:59.000Z

    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.

  12. No. 2 heating oil/propane program 1994--1995. Final report

    SciTech Connect (OSTI)

    McBrien, J.

    1995-05-01T23:59:59.000Z

    During the 1994--95 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 1994 through March 1995. This program augmented the existing Massachusetts data collection system and served several important functions. The information helped the federal and state governments respond to consumer, congressional and media inquiries regarding No. 2 oil and propane. The information also provided policy decision-makers with timely, accurate and consistent data to monitor current heating oil and propane markets and develop appropriate state responses when necessary. In addition, the communication network between states and the DOE was strengthened through this program. This final report begins with an overview of the unique events that had an impact on the petroleum markets prior to and during the reporting period. Next, the report summarizes the results from residential heating oil and propane price surveys conducted by DOER over the 1994--95 heating season. The report also incorporates the wholesale heating oil and propane prices and inventories collected by EIA and distributed to the states. Finally, the report outlines DOER`s use of the data.

  13. Heat Pipe Technology for Energy Conservation in the Process Industry

    E-Print Network [OSTI]

    Price, B. L. Jr.

    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... and utility industries. The heat pipe offers a unique. efficient heat transfer device that can recover valuable thermal energy resulting in reduced equipment and operating costs. Q-dot is the world leader in heat pipe technology and we have applied our...

  14. 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...

  15. 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...

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

    SciTech Connect (OSTI)

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

    2012-09-01T23:59:59.000Z

    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.

  17. Electrically heated DPF start-up strategy

    DOE Patents [OSTI]

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

    2012-04-10T23:59:59.000Z

    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.

  18. Diffusive propagation of wave packets in a fluctuating periodic potential

    E-Print Network [OSTI]

    Eman Hamza; Yang Kang; Jeffrey Schenker

    2010-10-05T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    James A Menart, Professor

    2013-02-22T23:59:59.000Z

    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

  20. Finite Volume Based Computer Program for Ground Source Heat Pump System

    SciTech Connect (OSTI)

    Menart, James A. [Wright State University

    2013-02-22T23:59:59.000Z

    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.

  1. PERIODIC WAVELET TRANSFORMS AND PERIODICITY JOHN J. BENEDETTO AND G

    E-Print Network [OSTI]

    Benedetto, John J.

    PERIODIC WAVELET TRANSFORMS AND PERIODICITY DETECTION JOHN J. BENEDETTO #3; AND G  OTZ E. PFANDER y Key words. Continuous wavelet transform, epileptic seizure prediction, periodicity detection algorithm, optimal generalized Haar wavelets, wavelet frames on Z. AMS subject classi#12;cations. 42C99, 42C

  2. Heat pipes for use in a magnetic field

    DOE Patents [OSTI]

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

    1983-07-19T23:59:59.000Z

    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.

  3. The quality assurance of heat fused thermoplastic pipeline joints

    E-Print Network [OSTI]

    Earles, Larry Lee

    1982-01-01T23:59:59.000Z

    with no Heating Pressure 23 6 Temperature Distribution in Drisco 6500 with 25 psi Heating Pressure 7 Three-Dimensional Temperature Distribution in Drisco 6500 During the Fusion Cycle (Heating Time = 30 sec) 8 Heat Transfer Nodel Used to Nodel the Heating... of Temperature on Joint Strength from the Latin Square Using Drisco 8000 with the Bead Removed 52 25 Effect of Heating Time on Joint Strength From the Latin Square Using Drisco 8000 with the Bead Removed 53 26 Effect of Fusion Pressure on Joint Strength...

  4. Quantum transport calculations using periodic boundaryconditions

    SciTech Connect (OSTI)

    Wang, Lin-Wang

    2004-06-15T23:59:59.000Z

    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.

  5. Heat transfer education : Keeping it relevant and vibrant.

    SciTech Connect (OSTI)

    Khounsary, A. M.

    1998-08-14T23:59:59.000Z

    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.

  6. INTERACTION OF A SOLAR SPACE HEATING SYSTEM WITH THE THERMAL BEHAVIOR OF A BUILDING

    E-Print Network [OSTI]

    Vilmer, Christian

    2013-01-01T23:59:59.000Z

    P(t) UAB time constant. Heat input power from a fan coil orof a building in response to heat input from an active solarS.R. of a building under heat input conditions for active

  7. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, Lance D. (Shelly, ID)

    1988-01-01T23:59:59.000Z

    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.

  8. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, L.D.

    1987-02-11T23:59:59.000Z

    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.

  9. Mass and Heat Recovery 

    E-Print Network [OSTI]

    Hindawai, S. M.

    2010-01-01T23:59:59.000Z

    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...

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

    SciTech Connect (OSTI)

    Not Available

    2010-12-01T23:59:59.000Z

    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.

  11. HEATING7.3. 1,2, or 3-d Heat Conduction Program

    SciTech Connect (OSTI)

    Childs, K.W. [Oak Ridge National Lab, TN (United States)

    1998-05-01T23:59:59.000Z

    HEATING7.2I and 7.3 is the most recent developmant in a series of heat-transfer codes and obsoletes all previous versions. HEATING can solve steady-state and/or transient heat conduction problems in one, two, or three-dimensional Cartesian, cylindrical coordinates 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 can be anisotropic. Materials may undergo a 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 graybody radiation problems may be modeled with user-defined factors for radiant exchange. The mesh spacing may be variable along each axis. HEATING uses a run time memory allocation scheme to avoid having to recompile to match memory requirements for each specific problem. HEATING utilizes free-form input.

  12. Thulium-170 heat source

    DOE Patents [OSTI]

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

    1992-01-01T23:59:59.000Z

    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.

  13. Kepler and the long-period variables

    SciTech Connect (OSTI)

    Hartig, Erich; Lebzelter, Thomas [University of Vienna, Department of Astrophysics, Türkenschanzstrasse 17, A-1180 Vienna (Austria); Cash, Jennifer [Department of Biological and Physical Sciences, South Carolina State University, P.O. Box 7024, Orangeburg, SC 29117 (United States); Hinkle, Kenneth H.; Mighell, Kenneth J. [National Optical Astronomy Observatories, P.O. Box 26732, Tucson, AZ 85726 (United States); Walter, Donald K., E-mail: erich.hartig@univie.ac.at, E-mail: thomas.lebzelter@univie.ac.at, E-mail: jcash@physics.scsu.edu, E-mail: hinkle@noao.edu, E-mail: mighell@noao.edu, E-mail: dkw@physics.scsu.edu [Department of Biological and Physical Sciences, South Carolina State University, P.O. Box 7296, Orangeburg, SC 29117 (United States)

    2014-12-01T23:59:59.000Z

    High-precision Kepler photometry is used to explore the details of asymptotic giant branch (AGB) light curves. Since AGB variability has a typical timescale on the order of a year, we discuss at length the removal of long-term trends and quarterly changes in Kepler data. Photometry for a small sample of nine semi-regular (SR) AGB stars is examined using a 30 minute cadence over a period of 45 months. While undergoing long-period variations of many magnitudes, the light curves are shown to be smooth at the millimagnitude level over much shorter time intervals. No flares or other rapid events were detected on a sub-day timescale. The shortest AGB period detected is on the order of 100 days. All the SR variables in our sample are shown to have multiple modes. This is always the first overtone, typically combined with the fundamental. A second common characteristic of SR variables is shown to be the simultaneous excitation of multiple closely separated periods for the same overtone mode. Approximately half the sample had a much longer variation in the light curve, likely a long secondary period (LSP). The light curves were all well represented by a combination of sinusoids. However, the properties of the sinusoids are time variable, with irregular variations present at low levels. No non-radial pulsations were detected. It is argued that the LSP variation seen in many SR variables is intrinsic to the star and linked to multiple mode pulsation.

  14. The periodicity of the eta Carinae events

    E-Print Network [OSTI]

    A. Damineli; M. F. Corcoran; D. J. Hillier; O. Stahl; R. S. Levenhagen; N. V. Leister; J. H. Groh; M. Teodoro; J. F. Albacete Colombo; F. Gonzalez; J. Arias; H. Levato; M. Grosso; N. Morrell; R. Gamen; G. Wallerstein; V. Niemela

    2007-11-27T23:59:59.000Z

    Extensive spectral observations of eta Carinae over the last cycle, and particularly around the 2003.5 low excitation event, have been obtained. The variability of both narrow and broad lines, when combined with data taken from two earlier cycles, reveal a common and well defined period. We have combined the cycle lengths derived from the many lines in the optical spectrum with those from broad-band X-rays, optical and near-infrared observations, and obtained a period length of 2022.7+-1.3 d. Spectroscopic data collected during the last 60 years yield an average period of 2020+-4 d, consistent with the present day period. The period cannot have changed by more than $\\Delta$P/P=0.0007 since 1948. This confirms the previous claims of a true, stable periodicity, and gives strong support to the binary scenario. We have used the disappearance of the narrow component of HeI 6678 to define the epoch of the Cycle 11 minimum, T_0=JD 2,452,819.8. The next event is predicted to occur on 2009 January 11 (+-2 days). The dates for the start of the minimum in other spectral features and broad-bands is very close to this date, and have well determined time delays from the HeI epoch.

  15. Electron temperature measurements during electron cyclotron heating on PDX using a ten channel grating polychromator

    SciTech Connect (OSTI)

    Cavallo, A.; Hsuan, H.; Boyd, D.; Grek, B.; Johnson, D.; Kritz, A.; Mikkelsen, D.; LeBlanc, B.; Takahashi, H.

    1984-10-01T23:59:59.000Z

    During first harmonic electron cyclotron heating (ECH) on the Princeton Divertor Experiment (PDX) (R/sub 0/ = 137 cm, a = 40 cm), electron temperature was monitored using a grating polychromator which measured second harmonic electron cyclotron emission from the low field side of the tokamak. Interference from the high power heating pulse on the broadband detectors in the grating instrument was eliminated by using a waveguide filter in the transmission line which brought the emission signal to the grating instrument. Off-axis (approx. 4 cm) location of the resonance zone resulted in heating without sawtooth or m = 1 activity. However, heating with the resonance zone at the plasma center caused very large amplitude sawteeth accompanied by strong m = 1 activity: ..delta..T/T/sub MAX/ approx. = 0.41, sawtooth period approx. = 4 msec, m = 1 period approx. = 90 ..mu.. sec, (11 kHz). This is the first time such intense MHD activity driven by ECH has been observed. (For both cases there was no sawtooth activity in the ohmic phase of the discharge before ECH.) At very low densities there is a clear indication that a superthermal electron population is created during ECH.

  16. Thermoelectric heat exchange element

    DOE Patents [OSTI]

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

    2007-08-14T23:59:59.000Z

    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.

  17. Mass and Heat Recovery

    E-Print Network [OSTI]

    Hindawai, S. M.

    2010-01-01T23:59:59.000Z

    - 1 - MASS AND HEAT RECOVERY SYSTEM SALAH MAHMOUD HINDAWI DIRECTOR HINDAWI FOR ENGINEERING SERVICES & CONTRACTING NEW DAMIETTA , EGYPT ABSTRACT : In the last few years heat recovery was under spot . and in air conditioning fields... ) as a heat recovery . and I use the water as a mass recovery . The source of mass and heat recovery is the condensate water which we were dispose and connect it to the drain lines . THE BENEFIT OF THIS SYSTEM ARE : 1) Using the heat energy from...

  18. Thermo-quantum diffusion in periodic potentials

    E-Print Network [OSTI]

    R. Tsekov

    2012-01-18T23:59:59.000Z

    Quantum Brownian motion in a periodic cosine potential is studied and a simple estimate of the tunneling effect is obtained in the frames of a quasi-equilibrium semiclassical approach. It is shown that the latter is applicable for heavy particles but electrons cannot be described properly since the quantum effects dominate over the thermal ones. The purely quantum electron diffusion is investigated at zero temperature and demonstrates that electrons do not obey the classical Einstein law of Brownian motion in the field of periodic potentials, since the dispersion of the wave packet increases logarithmically in time.

  19. Heat Integrate Heat Engines in Process Plants

    E-Print Network [OSTI]

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

    ~C. T min Table 3. Problem Table Algorithm Applied to Petrochemicals Process Interval GJ ltiour 'Temperatures ! C! 2 ) ? ~ Cold. Hot Aecumulated Heat Heat FJ.owa Interval Streams StrePlS Deficit. Input OUtput -OUtt!utInput. 20 30 -2... of heat which can be passed on in this manner is performed in column 2 and column 3 of Table 3. It is initially assumed that the heat input from external utilities is zero. This is represented in Table 3 by a zero input to the top interval. Having...

  20. Cloud Properties and Radiative Heating Rates for TWP

    SciTech Connect (OSTI)

    Comstock, Jennifer

    2013-11-07T23:59:59.000Z

    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.

  1. Cloud Properties and Radiative Heating Rates for TWP

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

    Comstock, Jennifer

    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.

  2. Passive ice freezing-releasing heat pipe

    DOE Patents [OSTI]

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

    1982-01-01T23:59:59.000Z

    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.

  3. turbulent heat International Journal of Numerical

    E-Print Network [OSTI]

    Lin, Wen-Wei

    flow behavior in a rectangular channel with streamwise-periodic ribs mounted on one of the principal. Nomenclature De = hydraulic diameter h = rib height H = channel height k = turbulent kinetic energy Nu = local June 1999 Accepted September 1999 Computation of enhanced turbulent heat transfer in a channel

  4. Optimal joule heating of the subsurface

    DOE Patents [OSTI]

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

    1994-07-05T23:59:59.000Z

    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.

  5. 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]

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

    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 ...

  6. Transitions to improved confinement regimes induced by changes in heating in zero-dimensional models for tokamak plasmas

    SciTech Connect (OSTI)

    Zhu, H. [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Chapman, S. C. [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Max Planck Institute for the Physics of Complex Systems, Dresden (Germany); Department of Mathematics and Statistics, University of Tromso, Tromso (Norway); Dendy, R. O. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom); Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Itoh Research Center for Plasma Turbulence, Kyushu University, Kasuga 816-8580 (Japan); Itoh, K. [National Institute for Fusion Science, Toki 509-5292 (Japan); Itoh Research Center for Plasma Turbulence, Kyushu University, Kasuga 816-8580 (Japan)

    2014-06-15T23:59:59.000Z

    It is shown that rapid substantial changes in heating rate can induce transitions to improved energy confinement regimes in zero-dimensional models for tokamak plasma phenomenology. We examine for the first time the effect of step changes in heating rate in the models of Kim and Diamond [Phys. Rev. Lett. 90, 185006 (2003)] and Malkov and Diamond [Phys. Plasmas 16, 012504 (2009)], which nonlinearly couple the evolving temperature gradient, micro-turbulence, and a mesoscale flow; and in the extension of Zhu et al. [Phys. Plasmas 20, 042302 (2013)], which couples to a second mesoscale flow component. The temperature gradient rises, as does the confinement time defined by analogy with the fusion context, while micro-turbulence is suppressed. This outcome is robust against variation of heating rise time and against introduction of an additional variable into the model. It is also demonstrated that oscillating changes in heating rate can drive the level of micro-turbulence through a period-doubling path to chaos, where the amplitude of the oscillatory component of the heating rate is the control parameter.

  7. Heat Pump for High School Heat Recovery

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    ) [3] Yayun FAN. Experimental study on a heat pump technology in solar thermal utilization[J]. Acta Energiae Solaris Sinica, Oct.,2002; Vol.23,No.5 ? 581-585.(In Chinese) [4] Nengxi JIANG. Air-conditioning Heat Pump Technology and Its Applications...

  8. Method and apparatus for determining vertical heat flux of geothermal field

    DOE Patents [OSTI]

    Poppendiek, Heinz F. (LaJolla, CA)

    1982-01-01T23:59:59.000Z

    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.

  9. 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...

  10. Original article Influence of heating conditions in continuous-flow

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , 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

  11. Observing ocean heat content using satellite gravity and altimetry

    E-Print Network [OSTI]

    Jayne, Steven

    : 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

  12. A Feasibility Study: Mining Daily Traces for Home Heating Control

    E-Print Network [OSTI]

    Whitehouse, Kamin

    , prediction 1. INTRODUCTION Heating, ventilation and cooling (HVAC) contributes most to a home's energy billsA Feasibility Study: Mining Daily Traces for Home Heating Control Dezhi Hong and Kamin Whitehouse and make predictions of arrival times. Our approach requires the minimum ef- forts for heating controls

  13. Photovoltaic roof heat flux

    E-Print Network [OSTI]

    Samady, Mezhgan Frishta

    2011-01-01T23:59:59.000Z

    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

  14. DistrictHeating Nuevasaladecalderasydistribucin

    E-Print Network [OSTI]

    Fraguela, Basilio B.

    DistrictHeating Nuevasaladecalderasydistribución decaloreneláreauniversitariade AZapateira Jesús, difusión. DISTRICT HEATING O CALEFACCIÓN DE BARRIO #12;MATERIALIZACIÓN INTEGRACIÓN VISUAL DE ELEMENTOS rendimiento global de la instalación. - Contabilización de pérdidas en tuberías de distribución. #12;DISTRICT

  15. HEAT TRANSFER FLUIDS

    E-Print Network [OSTI]

    Lenert, Andrej

    2012-01-01T23:59:59.000Z

    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 ...

  16. 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.

  17. Abrasion resistant heat pipe

    DOE Patents [OSTI]

    Ernst, Donald M. (Leola, PA)

    1984-10-23T23:59:59.000Z

    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.

  18. Solar heat receiver

    DOE Patents [OSTI]

    Hunt, Arlon J. (Oakland, CA); Hansen, Leif J. (Berkeley, CA); Evans, David B. (Orinda, CA)

    1985-01-01T23:59:59.000Z

    A receiver for converting solar energy to heat a gas to temperatures from 700.degree.-900.degree. 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.

  19. Solar heat receiver

    DOE Patents [OSTI]

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

    1982-09-29T23:59:59.000Z

    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.

  20. Industrial Waste Heat Recovery

    E-Print Network [OSTI]

    Ward, M. E.; Solomon, N. G.; Tabb, E. S.

    1980-01-01T23:59:59.000Z

    INDUSTRIAL WASTE HEAT RECOVREY M. E. Ward and N. G. Solomon E. S. Tabb Solar Turbines International and Gas Research Institute San Diego, California Chicago, Illinois ABSTRACT i I One hundred fifty reports were reviewed along with interviews... tests, promising low temperature heat exchanger tube alloys and coated surfaces were identified. 1INTROUCTION of advanced technology heat recovery techniques 1_ Recovering waste heat from the flue gases of the pr~ary objective. Specific objectives...

  1. Representing Periodic Functions by Fourier

    E-Print Network [OSTI]

    Vickers, James

    Representing Periodic Functions by Fourier Series 23.2 Introduction In this Section we show how, then the Fourier series expansion takes the form: f(t) = a0 2 + n=1 (an cos nt + bn sin nt) Our main purpose here Fourier coefficients of a function of period 2 calculate Fourier coefficients of a function of general

  2. A corrosive resistant heat exchanger

    DOE Patents [OSTI]

    Richlen, S.L.

    1987-08-10T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2013-09-15T23:59:59.000Z

    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.

  4. Acoustic Heating Peter Ulmschneider

    E-Print Network [OSTI]

    Ulmschneider, Peter

    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

  5. Heat Transfer Guest Editorial

    E-Print Network [OSTI]

    Kandlikar, Satish

    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

  6. 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.

  7. Liquid heat capacity lasers

    DOE Patents [OSTI]

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

    2007-05-01T23:59:59.000Z

    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.

  8. Convection, granulation and period jitter in classical Cepheids

    E-Print Network [OSTI]

    Neilson, Hilding R

    2014-01-01T23:59:59.000Z

    Analyses of recent observations of the sole classical Cepheid in the Kepler field, V1154 Cygni, found random changes of about 30 minutes in the pulsation period. These period changes challenge standard theories of pulsation and evolution because the period change is non-secular, and explaining this period jitter is necessary for understanding stellar evolution and the role of Cepheids as precise standard candles. We suggest that convection and convective hot spots can explain the observed period jitter. Convective hot spots alter the timing of flux maximum and minimum in the Cepheid light curve, hence change the measured pulsation period. We present a model of random hot spots that generate a localized flux excess that perturbs the Cepheid light curve and consequently the pulsation period which is consistent with the observed jitter. This result demonstrates how important understanding convection is for modeling Cepheid stellar structure and evolution, how convection determines the red edge of the instability...

  9. 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]

    Smith, S. W.

    "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...

  10. The long time behavior of diffusion in tilted periodic potentials

    E-Print Network [OSTI]

    2013-09-18T23:59:59.000Z

    Sep 18, 2013 ... In order to obtain more quantitative information about dynamical .... per(T),r = 1,2, denotes the space of the restriction to T of functions in Cr(R) ...

  11. 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 DataDepartment of Energy Your Density Isn't Your Destiny:RevisedAdvisoryStandard | Department ofEmily Knouse About UsEnergy Idling

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

    E-Print Network [OSTI]

    Skogestad, Sigurd

    A batch reactor heat recovery challenge problem Johannes Jäschke, Sigurd Skogestad Department reactors, which are discharged periodically. A cold process stream is to be used as a utility, and is split periods of the batch reactors, the reactor effluents are fed into the secondary sides of the heat

  13. Implementation issues for realtime optimization of a crude unit heat exchanger network

    E-Print Network [OSTI]

    Skogestad, Sigurd

    1 Implementation issues for real­time optimization of a crude unit heat exchanger network Tore Lid­ mentation of real time optimization results in a crude unit heat exchanger network. Two di#erent control

  14. Absorption heat pump system

    DOE Patents [OSTI]

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

    1984-01-01T23:59:59.000Z

    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.

  15. Applied heat transfer

    SciTech Connect (OSTI)

    Ganapathy, V.

    1982-01-01T23:59:59.000Z

    Heat transfer principles are discussed with emphasis on the practical aspects of the problems. Correlations for heat transfer and pressure drop from several worldwide sources for flow inside and outside of tubes, including finned tubes are presented, along with design and performance calculations of heat exchangers economizers, air heaters, condensers, waste-heat boilers, fired heaters, superheaters, and boiler furnaces. Vibration analysis for tube bundles and heat exchangers are also discussed, as are estimating gas-mixture properties at atmospheric and elevated pressures and life-cycle costing techniques. (JMT)

  16. HEATING AND COOLING PROTOSTELLAR DISKS

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    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...

  19. Heat pump apparatus

    DOE Patents [OSTI]

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

    1983-01-01T23:59:59.000Z

    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.

  20. Active microchannel heat exchanger

    DOE Patents [OSTI]

    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

    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.

  1. Method for restoring the resistance of indium oxide semiconductors after heating while in sealed structures

    DOE Patents [OSTI]

    Seager, C.H.; Evans, J.T. Jr.

    1998-11-24T23:59:59.000Z

    A method is described for counteracting increases in resistivity encountered when Indium Oxide resistive layers are subjected to high temperature annealing steps during semiconductor device fabrication. The method utilizes a recovery annealing step which returns the Indium Oxide layer to its original resistivity after a high temperature annealing step has caused the resistivity to increase. The recovery anneal comprises heating the resistive layer to a temperature between 100 C and 300 C for a period of time that depends on the annealing temperature. The recovery is observed even when the Indium Oxide layer is sealed under a dielectric layer. 1 fig.

  2. Method for restoring the resistance of indium oxide semiconductors after heating while in sealed structures

    DOE Patents [OSTI]

    Seager, Carleton H. (1304 Onava Ct., NE., Albuquerque, NM 87112); Evans, Jr., Joseph Tate (13609 Verbena Pl., NE., Albuquerque, NM 87112)

    1998-01-01T23:59:59.000Z

    A method for counteracting increases in resistivity encountered when Indium Oxide resistive layers are subjected to high temperature annealing steps during semiconductor device fabrication. The method utilizes a recovery annealing step which returns the Indium Oxide layer to its original resistivity after a high temperature annealing step has caused the resistivity to increase. The recovery anneal comprises heating the resistive layer to a temperature between 100.degree. C. and 300.degree. C. for a period of time that depends on the annealing temperature. The recovery is observed even when the Indium Oxide layer is sealed under a dielectric layer.

  3. Electron Cyclotron Heating in RFP plasmas

    SciTech Connect (OSTI)

    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

    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.

  4. Heating remote rooms in passive solar buildings

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1981-01-01T23:59:59.000Z

    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.

  5. Mechanics of planar periodic microstructures

    E-Print Network [OSTI]

    Prange, Sharon M. (Sharon Marie)

    2007-01-01T23:59:59.000Z

    The deformation of two-dimensional periodically patterned elastomeric sheets has been shown to trigger interesting pattern changes that are both repeatable and predictable (Bertoldi et al., 2007). Here, both square and ...

  6. Competitive Multi-period Pricing with Fixed Inventories

    E-Print Network [OSTI]

    Perakis, Georgia

    This paper studies the problem of multi-period pricing for perishable products in a competitive (oligopolistic) market. We study non cooperative Nash equilibrium policies for sellers. At the beginning of the time horizon, ...

  7. 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...

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

    SciTech Connect (OSTI)

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

    2011-01-01T23:59:59.000Z

    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.

  9. Policies supporting Heat Pump Technologies

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    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

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

    SciTech Connect (OSTI)

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

    1992-07-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    1992-07-01T23:59:59.000Z

    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.

  12. Optimization of Heat Exchangers

    SciTech Connect (OSTI)

    Ivan Catton

    2010-10-01T23:59:59.000Z

    The objective of this research is to develop tools to design and optimize heat exchangers (HE) and compact heat exchangers (CHE) for intermediate loop heat transport systems found in the very high temperature reator (VHTR) and other Generation IV designs by addressing heat transfer surface augmentation and conjugate modeling. To optimize heat exchanger, a fast running model must be created that will allow for multiple designs to be compared quickly. To model a heat exchanger, volume averaging theory, VAT, is used. VAT allows for the conservation of mass, momentum and energy to be solved for point by point in a 3 dimensional computer model of a heat exchanger. The end product of this project is a computer code that can predict an optimal configuration for a heat exchanger given only a few constraints (input fluids, size, cost, etc.). As VAT computer code can be used to model characteristics )pumping power, temperatures, and cost) of heat exchangers more quickly than traditional CFD or experiment, optimization of every geometric parameter simultaneously can be made. Using design of experiment, DOE and genetric algorithms, GE, to optimize the results of the computer code will improve heat exchanger disign.

  13. Heat pump system

    DOE Patents [OSTI]

    Swenson, Paul F.; Moore, Paul B.

    1983-06-21T23:59:59.000Z

    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.

  14. Heat pump system

    DOE Patents [OSTI]

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

    1983-01-01T23:59:59.000Z

    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.

  15. Fluidized bed heat treating system

    DOE Patents [OSTI]

    Ripley, Edward B; Pfennigwerth, Glenn L

    2014-05-06T23:59:59.000Z

    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.

  16. Summer HeatSummer Heat Heat stress solutions

    E-Print Network [OSTI]

    Liskiewicz, Maciej

    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

  17. Experimental and theoretical investigations of microwave heating

    E-Print Network [OSTI]

    Kota, Bhagat Chandra

    2004-09-30T23:59:59.000Z

    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...

  18. Tidal Heating of Extra-Solar Planets

    E-Print Network [OSTI]

    Brian Jackson; Richard Greenberg; Rory Barnes

    2008-02-29T23:59:59.000Z

    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.

  19. Water-heating dehumidifier

    DOE Patents [OSTI]

    Tomlinson, John J. (Knoxville, TN)

    2006-04-18T23:59:59.000Z

    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.

  20. Chaotic Transport in Planar Periodic Vortical Flows

    E-Print Network [OSTI]

    Taehoon Ahn; Seunghwan Kim

    1993-09-24T23:59:59.000Z

    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.

  1. Heat storage duration

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1981-01-01T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

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

    2012-08-21T23:59:59.000Z

    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.

  3. Periodic fluctuations in deep water formation due to sea ice

    E-Print Network [OSTI]

    Raj Saha

    2015-02-21T23:59:59.000Z

    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.

  4. Static Heat Loads in the LHC Arc Cryostats: Final Assessment

    E-Print Network [OSTI]

    Parma, V

    2010-01-01T23:59:59.000Z

    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 ...

  5. HEATS: Thermal Energy Storage

    SciTech Connect (OSTI)

    None

    2012-01-01T23:59:59.000Z

    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.

  6. Heat and mass exchanger

    DOE Patents [OSTI]

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

    2007-09-18T23:59:59.000Z

    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.

  7. Heat and mass exchanger

    DOE Patents [OSTI]

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

    2011-06-28T23:59:59.000Z

    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.

  8. 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 ......

  9. Passive solar space heating

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1980-01-01T23:59:59.000Z

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

  10. Heat rejection system

    DOE Patents [OSTI]

    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

    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.

  11. 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

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

    SciTech Connect (OSTI)

    NONE

    1995-05-01T23:59:59.000Z

    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.

  13. Some aspects of laser heating of engineering materials

    SciTech Connect (OSTI)

    Yilbas, B.S.; Al-Garni, A.Z. [KFUPM, Dhahran (Saudi Arabia). Mechanical Engineering Dept.

    1996-08-01T23:59:59.000Z

    Laser induced heating processes are important when a laser is used as a machine tool in industry, since the quality of the machining process strongly depends on the heating mechanism. The present study examines a heat transfer model that provides useful information on the laser induced interaction mechanism. Steady state and time dependent heating models are introduced and temperature profiles inside the materials are predicted. Using appropriate assumptions, the time for the surface temperature to reach 90% of its steady state value is estimated. To validate the theoretical predictions, experiments are performed to measure the surface temperature of the irradiated spot during the laser heating pulse. It is found that, during the use of a pulsed laser in the drilling process, as the heating progresses the drilling velocities rise while the liquid depth and time to reach steady state fall, in this case, the energy consumed for evaporation is higher than losses through conduction.

  14. Design of chemical reactors of the heat exchanger type

    E-Print Network [OSTI]

    McBeth, Lloyd Theodore

    1956-01-01T23:59:59.000Z

    , of the coolant varies with respect to its position in the tubes. A heat balance on the reactants is shown below. Heat balance on the reacting mass during time ae Heat in by generation = rV QR& 9 R R Heat transferred from p i = the tubes to the mass: na... at constant temper- ature, less and less heat must be removed as the reaction proceeds. This is accomplished by the gradual reduction of the coolant flow rate. A mefhod for the determination of the inanner in which the coolant rate must be varied...

  15. A climatic heat budget study of the Gulf of Mexico

    E-Print Network [OSTI]

    Etter, Paul Courtney

    1975-01-01T23:59:59.000Z

    of heat storage (G ) is calo~ lated apparently for the first time directly by use of available bathythermograph (BT) data. Heat flux di rergence due to currents (0 ), calculated as a residual in the heat budget equation, is small. The monthly mean... surface ( CA) . . 16 C. The rate of heat storage (Q ) 32 0. Solution of the oceanic heat budget 39 Comparison with Earlier Studies Summary 56 References Appendix A App ndix 3 Vita 61 79 vi LIST OF TA. '3LES Table Page Number of observations...

  16. 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

  17. Heat pipes and use of heat pipes in furnace exhaust

    DOE Patents [OSTI]

    Polcyn, Adam D. (Pittsburgh, PA)

    2010-12-28T23:59:59.000Z

    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.

  18. First university owned district heating system using biomass heat

    E-Print Network [OSTI]

    Northern British Columbia, University of

    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

  19. Microchannel heat sink assembly

    DOE Patents [OSTI]

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

    1992-03-24T23:59:59.000Z

    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.

  20. Solar heating system

    DOE Patents [OSTI]

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

    1982-01-01T23:59:59.000Z

    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.

  1. Knudsen heat capacity

    SciTech Connect (OSTI)

    Babac, Gulru, E-mail: babac@itu.edu.tr [Institute of Energy, Istanbul Technical University, Istanbul 34469 (Turkey)] [Institute of Energy, Istanbul Technical University, Istanbul 34469 (Turkey); Reese, Jason M. [School of Engineering, University of Edinburgh, Edinburgh EH9 3JL (United Kingdom)] [School of Engineering, University of Edinburgh, Edinburgh EH9 3JL (United Kingdom)

    2014-05-15T23:59:59.000Z

    We present a “Knudsen heat capacity” as a more appropriate and useful fluid property in micro/nanoscale gas systems than the constant pressure heat capacity. At these scales, different fluid processes come to the fore that are not normally observed at the macroscale. For thermodynamic analyses that include these Knudsen processes, using the Knudsen heat capacity can be more effective and physical. We calculate this heat capacity theoretically for non-ideal monatomic and diatomic gases, in particular, helium, nitrogen, and hydrogen. The quantum modification for para and ortho hydrogen is also considered. We numerically model the Knudsen heat capacity using molecular dynamics simulations for the considered gases, and compare these results with the theoretical ones.

  2. Improved solar heating systems

    DOE Patents [OSTI]

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

    1980-05-16T23:59:59.000Z

    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.

  3. Conductive and convective heat transfer in fluid flows between differentially heated and rotating cylinders

    E-Print Network [OSTI]

    Lopez, Jose M; Avila, Marc

    2015-01-01T23:59:59.000Z

    The flow of fluid confined between a heated rotating cylinder and a cooled stationary cylinder is a canonical experiment for the study of heat transfer in engineering. The theoretical treatment of this system is greatly simplified if the cylinders are assumed to be of infinite length or periodic in the axial direction, in which cases heat transfer occurs only through conduction as in a solid. We here investigate numerically heat transfer and the onset of turbulence in such flows by using both periodic and no-slip boundary conditions in the axial direction. We obtain a simple linear criterion that determines whether the infinite-cylinder assumption can be employed. The curvature of the cylinders enters this linear relationship through the slope and additive constant. For a given length-to-gap aspect ratio there is a critical Rayleigh number beyond which the laminar flow in the finite system is convective and so the behaviour is entirely different from the periodic case. The criterion does not depend on the Pra...

  4. RADIATIVE HEATING OF THE SOLAR CORONA

    SciTech Connect (OSTI)

    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

    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.

  5. Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal...

    Open Energy Info (EERE)

    heat flow values as high as several watts per meter squared can be found. Systematic interpretation of heat flow patterns sheds light on heat transfer mechanisms at depth on...

  6. Economic Options for Upgrading Waste Heat 

    E-Print Network [OSTI]

    Erickson, D. C.

    1983-01-01T23:59:59.000Z

    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...

  7. Economic Options for Upgrading Waste Heat

    E-Print Network [OSTI]

    Erickson, D. C.

    1983-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Kirol, L. D.

    for water and gas connections, and temperature variations. Recent work on heat pump cycles using complex compound reactions includes development of energy storage systems at laboratories in Europe (11) and the United States (12), and residential...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...

  9. ELECTRIC CO-HEATING: A METHOD FOR EVALUATING SEASONAL HEATING EFFICIENCIES AND HEAT LOSS RATES IN DWELLINGS

    E-Print Network [OSTI]

    Modera, M.P.

    2012-01-01T23:59:59.000Z

    Effi~ ciency of Fossil~Fired Heating Systems for LabelingInfo. Division, Ext. 6782 Electric Co-heating: A Methodfor Evaluating Seasonal Heating Efficiencies and Heat Loss

  10. Workshop on Condensing Heating and Water Heating Equipment

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

    Workshop on Condensing Heating and Water Heating Equipment Thursday, October 9, 2014 List of Attendees OrganizationAttendees DOE - John Cymbalsky - Ashley Armstrong - Johanna...

  11. 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 Falls...

  12. Proceedings: Heat exchanger workshop

    SciTech Connect (OSTI)

    Not Available

    1987-07-01T23:59:59.000Z

    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.

  13. Micro heat barrier

    DOE Patents [OSTI]

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

    2003-08-12T23:59:59.000Z

    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.

  14. Natural Circulation in the Blanket Heat Removal System During a Loss-of-Pumping Accident (LOFA) Based on Initial Conceptual Design

    SciTech Connect (OSTI)

    Hamm, L.L.

    1998-10-07T23:59:59.000Z

    A transient natural convection model of the APT blanket primary heat removal (HR) system was developed to demonstrate that the blanket could be cooled for a sufficient period of time for long term cooling to be established following a loss-of-flow accident (LOFA). The particular case of interest in this report is a complete loss-of-pumping accident. For the accident scenario in which pumps are lost in both the target and blanket HR systems, natural convection provides effective cooling of the blanket for approximately 68 hours, and, if only the blanket HR systems are involved, natural convection is effective for approximately 210 hours. The heat sink for both of these accident scenarios is the assumed stagnant fluid and metal on the secondary sides of the heat exchangers.

  15. Down hole periodic seismic generator

    DOE Patents [OSTI]

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

    1989-01-01T23:59:59.000Z

    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.

  16. Advanced downhole periodic seismic generator

    DOE Patents [OSTI]

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

    1991-07-16T23:59:59.000Z

    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.

  17. Complex Compound Chemical Heat Pumps 

    E-Print Network [OSTI]

    Rockenfeller, U.; Langeliers, J.; Horn, G.

    1987-01-01T23:59:59.000Z

    Complex-compound solid-vapor fluid pairs can be used in heat of reaction heat pumps for temperature amplifier (TA) as well as heat amplifier (HA) cycle configurations. This report describes the conceptual hardware design for complex compound...

  18. Energy 101: Geothermal Heat Pumps

    Broader source: Energy.gov [DOE]

    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 ...

  19. Complex Compound Chemical Heat Pumps

    E-Print Network [OSTI]

    Rockenfeller, U.; Langeliers, J.; Horn, G.

    Complex-compound solid-vapor fluid pairs can be used in heat of reaction heat pumps for temperature amplifier (TA) as well as heat amplifier (HA) cycle configurations. This report describes the conceptual hardware design for complex compound...

  20. Intergalactic dust and its photoelectric heating

    E-Print Network [OSTI]

    Akio K. Inoue; Hideyuki Kamaya

    2008-10-31T23:59:59.000Z

    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.

  1. Heat treatment furnace

    DOE Patents [OSTI]

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

    2014-10-21T23:59:59.000Z

    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.

  2. Specifying Waste Heat Boilers

    E-Print Network [OSTI]

    Ganapathy, V.

    or hydrochloric acid vapor should be mentioned upfront so the HRSG designer can take proper precauations while designing the unit.Material selection is also impacted by the presence of corrosive gases.If partial pressure of hydrogen is high in the gas stream...SPECIFYING WASTE HEAT BOILERS V.Ganapathy.ABCO Industries Abilene,Texas ABSTRACT Waste heat boilers or Heat Recovery Steam 'Generators(HRSGs) as they are often called are used to recover energy from waste gas streams in chemical plants...

  3. Quantum Operation Time Reversal

    SciTech Connect (OSTI)

    Crooks, Gavin E.

    2008-03-25T23:59:59.000Z

    The dynamics of an open quantum system can be described by a quantum operation: A linear, complete positive map of operators. Here, I exhibit a compact expression for the time reversal of a quantum operation, which is closely analogous to the time reversal of a classical Markov transition matrix. Since open quantum dynamics are stochastic, and not, in general, deterministic, the time reversal is not, in general, an inversion of the dynamics. Rather, the system relaxes toward equilibrium in both the forward and reverse time directions. The probability of a quantum trajectory and the conjugate, time reversed trajectory are related by the heat exchanged with the environment.

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

    E-Print Network [OSTI]

    Nasser Mohamed Ahmed

    2007-10-13T23:59:59.000Z

    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.

  5. NGNP Process Heat Utilization: Liquid Metal Phase Change Heat Exchanger

    SciTech Connect (OSTI)

    Piyush Sabharwall; Mike Patterson; Vivek Utgikar; Fred Gunnerson

    2008-09-01T23:59:59.000Z

    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.

  6. Liquid Phase Heating Systems

    E-Print Network [OSTI]

    Mordt, E. H.

    1979-01-01T23:59:59.000Z

    Temperature Water (HTW) central district heating systems are far superior to steam systems in large, spread out installations such as airports, universities and office complexes. Water, pressurized to keep it in the liquid state, is distributed at 400o...

  7. Composite heat damage assessment

    SciTech Connect (OSTI)

    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

    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.

  8. Mechanical Compression Heat Pumps 

    E-Print Network [OSTI]

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

    1986-01-01T23:59:59.000Z

    to develop, design and test compressors built to meet the needs of the mechanically demanding industrial heat pump applications which often require high compression ratios and temperatures in excess of 200 degrees F. This paper will review the theoretical...

  9. Photovoltaic roof heat flux

    E-Print Network [OSTI]

    Samady, Mezhgan Frishta

    2011-01-01T23:59:59.000Z

    e l Atmosphere ceiling, back panel roof, exposed roof insideSAN DIEGO Photovoltaic Roof Heat Flux A Thesis submitted i no n Convection Exposed Roof Temperature Seasonal Temperature

  10. Passive solar heating analysis

    SciTech Connect (OSTI)

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

    1984-01-01T23:59:59.000Z

    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.

  11. Electron Heating in Quasi-Perpendicular Shocks

    E-Print Network [OSTI]

    Mozer, F S

    2013-01-01T23:59:59.000Z

    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...

  12. Heat capacity at the glass transition

    E-Print Network [OSTI]

    Kostya Trachenko; Vadim Brazhkin

    2010-07-13T23:59:59.000Z

    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.

  13. Microfabricated fuel heating value monitoring device

    DOE Patents [OSTI]

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

    2010-05-04T23:59:59.000Z

    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.

  14. Mechanical Compression Heat Pumps

    E-Print Network [OSTI]

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

    dampened because there is a current abundance of the basic sources of industrial energy (namely oil and natural gas). Meanwhile, Mycom used the window of the current opportunities to develop, design and test compressors built to meet the needs... requirements of the compressors which constitute the heart and soul of the system. It will also provide a quick survey of the available types of compressors for heat pumping and some of the industrial processes where simultaneous heating and cooling...

  15. K-State Turfgrass Research Report of Progress 2006 TITLE: Membrane Lipid Composition and Heat Tolerance in Kentucky Bluegrass,

    E-Print Network [OSTI]

    ) Identify and quantify specific lipid compositional changes under heat stress; 3) and to discover. Heat stress may damage cell membranes in cool-season turfgrasses, causing leakage of cytoplasm period. Although the temperature was thereafter increased to induce heat stress for later lipids

  16. Convective heat flow probe

    DOE Patents [OSTI]

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

    1984-01-09T23:59:59.000Z

    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.

  17. Radial flow heat exchanger

    DOE Patents [OSTI]

    Valenzuela, Javier (Hanover, NH)

    2001-01-01T23:59:59.000Z

    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.

  18. Heat exchanger device and method for heat removal or transfer

    DOE Patents [OSTI]

    Koplow, Jeffrey P

    2013-12-10T23:59:59.000Z

    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.

  19. 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 Østergaard Jensen

  20. Heat exchanger device and method for heat removal or transfer

    DOE Patents [OSTI]

    Koplow, Jeffrey P. (San Ramon, CA)

    2012-07-24T23:59:59.000Z

    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.

  1. PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP W. D. C. Richards and W. L. Auxer) which employs a natural gas fired Stirling engine to drive a Rankine cycle vapor compressor is presently by the heat pump effect. The Stirling engine/Rankine cycle refrigeration loop heat pump being developed would

  2. Waste Heat Recovery Using a Circulating Heat Medium Loop

    E-Print Network [OSTI]

    Manning, E., Jr.

    1981-01-01T23:59:59.000Z

    by a circulating heat medium loop where waste heat is recovered for useful purposes. The heat medium chosen is turbine fuel. It is pumped around the refinery to pick up heat at the crude distilling unit, the hydrocracker, the catalytic cracker...

  3. Tsallis Distribution Decorated With Log-Periodic Oscillation

    E-Print Network [OSTI]

    Wilk, Grzegorz

    2015-01-01T23:59:59.000Z

    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.

  4. Thermal Boundary Resistance and Heat Diffusion in AlGaN/GaN HFETs Konstantin A. Filippov and Alexander A. Balandin

    E-Print Network [OSTI]

    , and radar applications [1-3]. At the same time, performance of these devices has been limited by self-heating [1, 4]. Thus, accurate modeling of heat diffusion and self-heating effects in Al

  5. Periodic fluctuations in deep water formation due to sea ice

    E-Print Network [OSTI]

    Saha, Raj

    2015-01-01T23:59:59.000Z

    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...

  6. Sadi Carnot's Ingenious Reasoning of Ideal Heat Engine Reversible Cycles

    E-Print Network [OSTI]

    Kostic, Milivoje M.

    Sadi Carnot's Ingenious Reasoning of Ideal Heat Engine Reversible Cycles MILIVOJE M. KOSTIC and speculations flourished. Carnot's reasoning of reversible cycles is in many ways equal if not more significant was not noticed at his time, when his ingenious reasoning of ideal heat engine reversible cycles is not fully

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

    SciTech Connect (OSTI)

    NONE

    1996-05-01T23:59:59.000Z

    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.

  8. Toolbox Safety Talk Heat Stress

    E-Print Network [OSTI]

    Pawlowski, Wojtek

    Toolbox Safety Talk Heat Stress Environmental Health & Safety Facilities Safety & Health Section for inducing heat stress. When the body is unable to cool itself by sweating, several heat-induced illnesses Stress · Know signs/symptoms of heat-related illnesses; monitor yourself and coworkers. · Block out

  9. temperature heat pumps applied to

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    losses (waste heat) 250-300°C......1100°C ~ 100 TWh/year Low temperature thermal losses (waste heat) 25°C;Waste heat recovery (1) In a decreasing energetic interest order Achema 2012 Frankfurt June 21th 2012>>Twaste #12;Waste heat recovery (2) Achema 2012 Frankfurt June 21th 2012 There is no interesting thermal

  10. Capture of Heat Energy from Diesel Engine Exhaust

    SciTech Connect (OSTI)

    Chuen-Sen Lin

    2008-12-31T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  12. Periodic table for topological insulators and superconductors

    E-Print Network [OSTI]

    Alexei Kitaev

    2009-01-20T23:59:59.000Z

    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.

  13. Heat distribution ceramic processing method

    DOE Patents [OSTI]

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

    2001-01-01T23:59:59.000Z

    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.

  14. Heat and Power Systems Design

    E-Print Network [OSTI]

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

    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...

  15. A phase-field method for 3D simulation of two-phase heat transfer

    E-Print Network [OSTI]

    X. Zheng

    2014-12-04T23:59:59.000Z

    Upper and lower walls assume adiabatic temperature boundary conditions and periodic ...... Then we compare our results of the temperature distribution with the ...... [27] Y. Sun, I.S. Wichman, On transient heat conduction in a one-dimensional.

  16. Induction heaters used to heat subsurface formations

    DOE Patents [OSTI]

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

    2012-04-24T23:59:59.000Z

    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.

  17. Heat treatment of exchangers to remove coke

    SciTech Connect (OSTI)

    Turner, J.D.

    1990-02-20T23:59:59.000Z

    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.

  18. Air heating system

    DOE Patents [OSTI]

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

    1983-03-01T23:59:59.000Z

    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.

  19. Acoustical heat pumping engine

    DOE Patents [OSTI]

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

    1983-08-16T23:59:59.000Z

    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.

  20. Acoustical heat pumping engine

    DOE Patents [OSTI]

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

    1983-08-16T23:59:59.000Z

    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.

  1. Solar industrial process heat

    SciTech Connect (OSTI)

    Lumsdaine, E.

    1981-04-01T23:59:59.000Z

    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)

  2. Planar resonant periodic orbits in Kuiper belt dynamics

    E-Print Network [OSTI]

    George Voyatzis; Thomas Kotoulas

    2005-02-28T23:59:59.000Z

    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.

  3. Passive ice freezing-releasing heat pipe. [Patent application

    DOE Patents [OSTI]

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

    1980-09-29T23:59:59.000Z

    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.

  4. Enhancement of Pool Boiling Heat Transfer in Confined Space

    E-Print Network [OSTI]

    Hsu, Chia-Hsiang

    2014-05-05T23:59:59.000Z

    Pool boiling is an effective method used in many technical applications for a long time. Its highly efficient heat transfer performance results from not only the convection effect but also the phase change process in pool boiling. Pool boiling...

  5. The Use of Infrared Technology To Detect Heat Loss

    E-Print Network [OSTI]

    Faulkner, K.

    1979-01-01T23:59:59.000Z

    . 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....

  6. Heat-transfer coefficients in agitated vessels. Latent heat models

    SciTech Connect (OSTI)

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

    1996-03-01T23:59:59.000Z

    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.

  7. Geothermal direct-heat utilization assistance. Federal Assistance Program, Quarterly project progress report, October--December 1994

    SciTech Connect (OSTI)

    Not Available

    1994-12-31T23:59:59.000Z

    The report summarizes activities of the Geo-Heat Center (GHC) at Oregon Institute of Technology for the first quarter of Fiscal Year 1995. It describes contacts with parties during this period related to assistance with geothermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, resources and equipment. Research is also being conducted on geothermal energy cost evaluation, low-temperature geothermal resource assessment, use of silica waste from the Cerro Prieto geothermal field as construction materials and geothermal heat pumps. Outreach activities include the publication of a quarterly Bulletin on direct heat applications and dissemination of information on low-temperature geothermal resources and utilization.

  8. Turbulent transport phenomena in a channel with periodic rib turbulators

    SciTech Connect (OSTI)

    Liou, T.M.; Hwang, J.J.; Chen, S.H. (National Tsing Hua University, Hsinchu (Taiwan))

    1992-09-01T23:59:59.000Z

    Periodic fully developed turbulent flow in a 2D channel with rib turbulators on two opposite walls has been studied numerically and experimentally. In numerical predictions, an algebraic Reynolds stress turbulence model is adopted, and a smoothed hybrid central/skew upstream difference scheme is developed. In experiments, the laser-Doppler velocimetry and laser holographic interferometry are employed to measure the local flow and heat transfer characteristics. The results are obtained with the ratio of pitch to rib height 5, 10, 15, and 20, for Reynolds number of 3.3 x 10 exp 4 and are presented in terms of the reattachment length, mean velocity and turbulent kinetic energy profiles, isotherm patterns, and distributions of local pressure recovery and Nusselt number. A detailed comparison with experimental data shows that the present calculations have an improvement over the previous work in the prediction of periodic ribbed-wall flow and heat transfer. In addition, regions susceptible to hot spots are identified by examining the distributions of the local Nusselt number. Furthermore, the enhancement of mean Nusselt number is documented in terms of relative contributions of the increased turbulence intensity and surface area provided by the ribs. 32 refs.

  9. Thermal mass assessment: an explanation of the mechanisms by which building mass influences heating and cooling energy requirements

    SciTech Connect (OSTI)

    Childs, K.W.; Courville, G.E.; Bales, E.L.

    1983-09-01T23:59:59.000Z

    The influence that building mass has on energy consumption for heating and cooling has been the subject of some controversy. This controversy is, in part, due to a lack of understanding of the heat transfer mechanics occurring within a building and of how they affect energy usage. This report offers a step-by-step development of the principles of heat transfer in buildings as they pertain to thermal mass. The report is targeted for persons who are unfamiliar with the topic of thermal mass, but who possess some technical background. It is concluded that for the mass of a building to reduce energy usage, the building must undergo alternating periods of net energy gain and loss. In other words, during the heating season the indoor temperature must at times float above the thermostat set point temperature to reduce energy consumption. During the cooling season, the indoor temperature must occasionally drop below the set point temperature. Other issues addressed include the effects of mass on peak loads, equipment cycling, thermostat setback, and comfort. Strategies to maximize benefits of mass are discussed.

  10. Investigation of long-period fiber gratings induced by high-intensity femtosecond UV laser pulses

    E-Print Network [OSTI]

    Nikogosyan, David N.

    efficiency with that for other existing meth- ods of recording. We studied the temperature sensing properties changes in the fiber core induced by thermal heating, were developed. They include the use of a CO2 laserInvestigation of long-period fiber gratings induced by high-intensity femtosecond UV laser pulses

  11. 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

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

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    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...

  13. The Beckett System Recovery and Utilization of Low Grade Waste Heat From Flue Gas

    E-Print Network [OSTI]

    Henderson, W. R.; DeBiase, J. F.

    1983-01-01T23:59:59.000Z

    . During low demand periods, the unit is gas-fired and produces 150 psi steam at high efficiency. In the fall, the heat exchanger is converted to accept flue gas from the large original water tube boilers. The flue gas heats water, which preheats make...

  14. Quantum optomechanical piston engines powered by heat

    E-Print Network [OSTI]

    Andrea Mari; Alessandro Farace; Vittorio Giovannetti

    2014-07-31T23:59:59.000Z

    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.

  15. Finite-difference time-domain simulation of fusion plasmas at radiofrequency time scales

    SciTech Connect (OSTI)

    Smithe, David N. [Tech-X Corporation, 5621 Arapahoe Avenue, Suite A, Boulder, Colorado 80303 (United States)

    2007-05-15T23:59:59.000Z

    Simulation of dense plasmas in the radiofrequency range are typically performed in the frequency domain, i.e., by solving Laplace-transformed Maxwell's equations. This technique is well-suited for the study of linear heating and quasilinear evolution, but does not generalize well to the study of nonlinear phenomena. Conversely, time-domain simulation in this range is difficult because the time scale is long compared to the electron plasma wave period, and in addition, the various cutoff and resonance behaviors within the plasma insure that any explicit finite-difference scheme would be numerically unstable. To resolve this dilemma, explicit finite-difference Maxwell terms are maintained, but a carefully time-centered locally implicit method is introduced to treat the plasma current, such that all linear plasma dispersion behavior is faithfully reproduced at the available temporal and spatial resolution, despite the fact that the simulation time step may exceed the electron gyro and electron plasma time scales by orders of magnitude. Demonstrations are presented of the method for several classical benchmarks, including mode conversion to ion cyclotron wave, cyclotron resonance, propagation into a plasma-wave cutoff, and tunneling through low-density edge plasma.

  16. Commissioning Tools for Heating/Cooling System in Residence - Verification of Floor Heating System and Room Air Conditioning System Performance 

    E-Print Network [OSTI]

    Miura, H.; Hokoi, S.; Iwamae, A.; Umeno, T.; Kondo, S.

    2004-01-01T23:59:59.000Z

    Tools of evaluating the performance of floor heating and room air conditioner are examined as a commissioning tool. Simple method is needed to check these performance while in use by residents, because evaluation currently requires significant time...

  17. Commissioning Tools for Heating/Cooling System in Residence - Verification of Floor Heating System and Room Air Conditioning System Performance

    E-Print Network [OSTI]

    Miura, H.; Hokoi, S.; Iwamae, A.; Umeno, T.; Kondo, S.

    2004-01-01T23:59:59.000Z

    Tools of evaluating the performance of floor heating and room air conditioner are examined as a commissioning tool. Simple method is needed to check these performance while in use by residents, because evaluation currently requires significant time...

  18. Wastewater heat recovery apparatus

    DOE Patents [OSTI]

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

    1992-01-01T23:59:59.000Z

    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.

  19. Wastewater heat recovery apparatus

    DOE Patents [OSTI]

    Kronberg, J.W.

    1992-09-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

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

    2010-08-28T23:59:59.000Z

    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.

  1. Heat exchange assembly

    DOE Patents [OSTI]

    Lowenstein, Andrew; Sibilia, Marc; Miller, Jeffrey; Tonon, Thomas S.

    2004-06-08T23:59:59.000Z

    A heat exchange assembly comprises a plurality of plates disposed in a spaced-apart arrangement, each of the plurality of plates includes a plurality of passages extending internally from a first end to a second end for directing flow of a heat transfer fluid in a first plane, a plurality of first end-piece members equaling the number of plates and a plurality of second end-piece members also equaling the number of plates, each of the first and second end-piece members including a recessed region adapted to fluidly connect and couple with the first and second ends of the plate, respectively, and further adapted to be affixed to respective adjacent first and second end-piece members in a stacked formation, and each of the first and second end-piece members further including at least one cavity for enabling entry of the heat transfer fluid into the plate, exit of the heat transfer fluid from the plate, or 180.degree. turning of the fluid within the plate to create a serpentine-like fluid flow path between points of entry and exit of the fluid, and at least two fluid conduits extending through the stacked plurality of first and second end-piece members for providing first fluid connections between the parallel fluid entry points of adjacent plates and a fluid supply inlet, and second fluid connections between the parallel fluid exit points of adjacent plates and a fluid discharge outlet so that the heat transfer fluid travels in parallel paths through each respective plate.

  2. Periodic relativity: basic framework of the theory

    E-Print Network [OSTI]

    Vikram H. Zaveri

    2014-11-25T23:59:59.000Z

    An alternative gravity theory is proposed which does not rely on Riemannian geometry and geodesic trajectories. The theory named periodic relativity (PR) does not use the weak field approximation and allows every two body system to deviate differently from the flat Minkowski metric. PR differs from general relativity (GR) in predictions of the proper time intervals of distant objects. PR proposes a definite connection between the proper time interval of an object and gravitational frequency shift of its constituent particles as the object travels through the gravitational field. PR is based on the dynamic weak equivalence principle which equates the gravitational mass with the relativistic mass. PR provides very accurate solutions for the Pioneer anomaly and the rotation curves of galaxies outside the framework of general relativity. PR satisfies Einstein's field equations with respect to the three major GR tests within the solar system and with respect to the derivation of Friedmann equation in cosmology. This article defines the underlying framework of the theory.

  3. Low Level Heat Recovery Through Heat Pumps and Vapor Recompression 

    E-Print Network [OSTI]

    Gilbert, J.

    1980-01-01T23:59:59.000Z

    of each approach as a function of the source and sink temperatures and magnitude of heat flow. Generic heat pumps and vapor recompression designs are explained, costed, estimated in performance, and evaluated as a function of the economic parameters...

  4. Modeling of Heat Transfer in Geothermal Heat Exchangers 

    E-Print Network [OSTI]

    Cui, P.; Man, Y.; Fang, Z.

    2006-01-01T23:59:59.000Z

    Ground-coupled heat pump (GCHP) systems have been gaining increasing popularity for space conditioning in residential and commercial buildings. The geothermal heat exchanger (GHE) is devised for extraction or injection of thermal energy from...

  5. HEAT TRANSFER IN UNDERGROUND HEATING EXPERIMENTS IN GRANITE, STRIPA, SWEDEN

    E-Print Network [OSTI]

    Chan, T.

    2010-01-01T23:59:59.000Z

    Session on Heat Transfer in Nuclear Waste Disposal, C'.heat transfer processes associated with underground nuclear wasteheat transfer and related processes in an un­ derground environment similar to that expected in a mined nuclear waste

  6. TRANSPARENT HEAT MIRRORS FOR PASSIVE SOLAR HEATING APPLICATIONS

    E-Print Network [OSTI]

    Selkowitz, S.

    2011-01-01T23:59:59.000Z

    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

  7. Low Level Heat Recovery Through Heat Pumps and Vapor Recompression

    E-Print Network [OSTI]

    Gilbert, J.

    1980-01-01T23:59:59.000Z

    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...

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

    SciTech Connect (OSTI)

    Oland, CB

    2004-08-19T23:59:59.000Z

    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.

  9. Heat Transfer Derivation of differential equations for heat transfer conduction

    E-Print Network [OSTI]

    Veress, Alexander

    ) 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

  10. Residential GSHPs: Efficiency With Short Payback Periods

    SciTech Connect (OSTI)

    Cooperman, Alissa; Dieckmann, John; Brodrick, James

    2012-04-30T23:59:59.000Z

    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.

  11. Distributed Generation with Heat Recovery and Storage

    SciTech Connect (OSTI)

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

    2005-07-29T23:59:59.000Z

    Electricity generated by distributed energy resources (DER) located close to end-use loads has the potential to meet consumer requirements more efficiently than the existing centralized grid. Installation of DER allows consumers to circumvent the costs associated with transmission congestion and other non-energy costs of electricity delivery and potentially to take advantage of market opportunities to purchase energy when attractive. On-site thermal power generation is typically less efficient than central station generation, but by avoiding non-fuel costs of grid power and utilizing combined heat and power (CHP) applications, i.e., recovering heat from small-scale on-site generation to displace fuel purchases, then DER can become attractive to a strictly cost-minimizing consumer. In previous efforts, the decisions facing typical commercial consumers have been addressed using a mixed-integer linear programme, the DER Customer Adoption Model(DER-CAM). Given the site s energy loads, utility tariff structure, and information (both technical and financial) on candidate DER technologies, DER-CAM minimizes the overall energy cost for a test year by selecting the units to install and determining their hourly operating schedules. In this paper, the capabilities of DER-CAM are enhanced by the inclusion of the option to store recovered low-grade heat. By being able to keep an inventory of heat for use in subsequent periods, sites are able to lower costs even further by reducing off-peak generation and relying on storage. This and other effects of storages are demonstrated by analysis of five typical commercial buildings in San Francisco, California, and an estimate of the cost per unit capacity of heat storage is calculated.

  12. Distributed Generation with Heat Recovery and Storage

    SciTech Connect (OSTI)

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

    2006-06-16T23:59:59.000Z

    Electricity produced by distributed energy resources (DER)located close to end-use loads has the potential to meet consumerrequirements more efficiently than the existing centralized grid.Installation of DER allows consumers to circumvent the costs associatedwith transmission congestion and other non-energy costs of electricitydelivery and potentially to take advantage of market opportunities topurchase energy when attractive. On-site, single-cycle thermal powergeneration is typically less efficient than central station generation,but by avoiding non-fuel costs of grid power and by utilizing combinedheat and power (CHP) applications, i.e., recovering heat from small-scaleon-site thermal generation to displace fuel purchases, DER can becomeattractive to a strictly cost-minimizing consumer. In previous efforts,the decisions facing typical commercial consumers have been addressedusing a mixed-integer linear program, the DER Customer Adoption Model(DER-CAM). Given the site s energy loads, utility tariff structure, andinformation (both technical and financial) on candidate DER technologies,DER-CAM minimizes the overall energy cost for a test year by selectingthe units to install and determining their hourly operating schedules. Inthis paper, the capabilities of DER-CAM are enhanced by the inclusion ofthe option to store recovered low-grade heat. By being able to keep aninventory of heat for use in subsequent periods, sites are able to lowercosts even further by reducing lucrative peak-shaving generation whilerelying on storage to meet heat loads. This and other effects of storageare demonstrated by analysis of five typical commercial buildings in SanFrancisco, California, USA, and an estimate of the cost per unit capacityof heat storage is calculated.

  13. Thermoelectric generators as self-oscillating heat engines

    E-Print Network [OSTI]

    Robert Alicki

    2015-05-30T23:59:59.000Z

    In the previous paper of Alicki et.al. a model of a solar cell has been proposed in which the non-periodic source of energy - photon flux - drives the collective periodic motion of electrons in a form of plasma oscillations. Subsequently, plasma oscillations are rectified by the p-n junction diode into the direct current (work). This approach makes a solar cell similar to standard macroscopic heat motors or turbines which always contain two heat baths, the working medium and the periodically moving piston or rotor. Here, a very similar model is proposed in order to describe the operation principles of thermoelectric generators based either on bimetallic or semiconductor p-n junctions. Again plasma oscillation corresponds to a piston and sunlight is replaced by a hot bath. The mathematical formalism is based on the Markovian master equations which can be derived in a rigorous way from the underlying Hamiltonian models and are consistent with the laws of thermodynamics.

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

    E-Print Network [OSTI]

    Cunningham, Timothy; Bildsten, Lars

    2015-01-01T23:59:59.000Z

    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...

  15. Fast reactor power plant design having heat pipe heat exchanger

    DOE Patents [OSTI]

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

    1984-08-30T23:59:59.000Z

    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.

  16. Fast reactor power plant design having heat pipe heat exchanger

    DOE Patents [OSTI]

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

    1985-01-01T23:59:59.000Z

    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.

  17. Design of Heat Exchanger for Heat Recovery in CHP Systems

    E-Print Network [OSTI]

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

    with a heat exchanger to work as a Combined Heat and Power system for the University which will supplement the chilled water supply and electricity. The design constraints of the heat recovery unit are the specifications of the turbine and the chiller...

  18. Heat-transfer coefficients in agitated vessels. Sensible heat models

    SciTech Connect (OSTI)

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

    1995-12-01T23:59:59.000Z

    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.

  19. Heat Shock-Induced Thermoprotection of Action Potentials in the Locust Flight System

    E-Print Network [OSTI]

    Robertson, Meldrum

    . Prior HS protects neural circuitry from a subsequent heat stress but little is known about during a heat stress. HS did not alter the timing of representative depressor or elevator muscle activity John Wiley & Sons, Inc. J Neurobiol 49: 188­199, 2001 Keywords: heat stress; thermotolerance; neuronal

  20. Heating of trapped ions from the quantum ground state Q. A. Turchette,*,

    E-Print Network [OSTI]

    Sackett, Cass

    Heating of trapped ions from the quantum ground state Q. A. Turchette,*, D. Kielpinski, B. E. King. Monroe, and D. J. Wineland Time and Frequency Division, National Institute of Standards and Technology heating of laser-cooled 9 Be ions held in radio-frequency Paul traps. We have measured heating rates

  1. 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

  2. DEVELOPING IMPROVED TRAVEL TIME RELIABILITY MEASURES FOR REAL-TIME AND ARCHIVED ITS DATA

    E-Print Network [OSTI]

    Bertini, Robert L.

    including travel time, 95th percentile travel time, travel time index, buffer index planning time index-based detector data, collected in periodic special studies, or estimated using simulation [1,3]: 95th Percentile between 95th percentile travel time and mean travel time, divided by mean travel time. Planning Time Index

  3. Heat Recovery from Coal Gasifiers

    E-Print Network [OSTI]

    Wen, H.; Lou, S. C.

    1981-01-01T23:59:59.000Z

    This paper deals with heat recovery from pressurized entrained and fixed bed coal gasifiers for steam generation. High temperature waste heat, from slagging entrained flow coal gasifier, can be recovered effectively in a series of radiant...

  4. Central Multifamily Water Heating Systems

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Building America Program is hosting a no-cost, webinar-based training on Central Multifamily Water Heating Systems. The webinar will focus the effective use of central heat pump water heaters...

  5. Heat Pumps - Theory and Applications

    E-Print Network [OSTI]

    Altin, M.

    1982-01-01T23:59:59.000Z

    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....

  6. 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...

  7. 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...

  8. Heat Pipes: An Industrial Application

    E-Print Network [OSTI]

    Murray, F.

    1984-01-01T23:59:59.000Z

    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...

  9. Challenges in Industrial Heat Recovery

    E-Print Network [OSTI]

    Dafft, T.

    2007-01-01T23:59:59.000Z

    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...

  10. 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

  11. Heat Pipes: An Industrial Application 

    E-Print Network [OSTI]

    Murray, F.

    1984-01-01T23:59:59.000Z

    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...

  12. Challenges in Industrial Heat Recovery 

    E-Print Network [OSTI]

    Dafft, T.

    2007-01-01T23:59:59.000Z

    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...

  13. Low Level Heat Recovery Technology

    E-Print Network [OSTI]

    O'Brien, W. J.

    1982-01-01T23:59:59.000Z

    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...

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

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

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

    2006-01-30T23:59:59.000Z

    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.

  16. FLOWS AND MOTIONS IN MOSS IN THE CORE OF A FLARING ACTIVE REGION: EVIDENCE FOR STEADY HEATING

    SciTech Connect (OSTI)

    Brooks, David H.; Warren, Harry P., E-mail: dhbrooks@ssd5.nrl.navy.mi [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2009-09-20T23:59:59.000Z

    We present new measurements of the time variability of intensity, Doppler, and nonthermal velocities in moss in an active region core observed by the EUV Imaging Spectrometer on Hinode in 2007 June. The measurements are derived from spectral profiles of the Fe XII 195 A line. Using the 2'' slit, we repeatedly scanned 150'' by 150'' in a few minutes. This is the first time it has been possible to make such velocity measurements in the moss, and the data presented are the highest cadence spatially resolved maps of moss Doppler and nonthermal velocities ever obtained in the corona. The observed region produced numerous C- and M-class flares with several occurring in the core close to the moss. The magnetic field was therefore clearly changing in the active region core, so we ought to be able to detect dynamic signatures in the moss if they exist. Our measurements of moss intensities agree with previous studies in that a less than 15% variability is seen over a period of 16 hr. Our new measurements of Doppler and nonthermal velocities reveal no strong flows or motions in the moss, nor any significant variability in these quantities. The results confirm that moss at the bases of high temperature coronal loops is heated quasi-steadily. They also show that quasi-steady heating can contribute significantly even in the core of a flare productive active region. Such heating may be impulsive at high frequency, but if so it does not give rise to large flows or motions.

  17. Fourier analysis of conductive heat transfer for glazed roofing materials

    SciTech Connect (OSTI)

    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

    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.

  18. CONTROL SYSTEM FOR SOLAR HEATING and COOLING

    E-Print Network [OSTI]

    Dols, C.

    2010-01-01T23:59:59.000Z

    for the solar-heated hot water. This heater can be seen inwater (solar heated, boosted, or heated entirely in the auxiliary heater)

  19. CONTROL SYSTEM FOR SOLAR HEATING and COOLING

    E-Print Network [OSTI]

    Dols, C.

    2010-01-01T23:59:59.000Z

    solar heating and cooling systems covering a wide range ofpractical heating and cooling system configurations andexperimental heating and cooling system, the main purpose of

  20. 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...

  1. HEAT AND MOISTURE TRANSFER THROUGH CLOTHING

    E-Print Network [OSTI]

    Voelker, Conrad; Hoffmann, Sabine; Kornadt, Oliver; Arens, Edward; Zhang, Hui; Huizenga, Charlie

    2009-01-01T23:59:59.000Z

    R. C. Eberhart (ed), Heat transfer in medicine and biology.between convective heat transfer and mass transferConvective and radiative heat transfer coefficients for

  2. Heat and moisture transfer through clothing

    E-Print Network [OSTI]

    Voelker, Conrad; Hoffmann, Sabine; Kornadt, Oliver; Arens, Edward; Zhang, Hui; Huizenga, Charlie

    2009-01-01T23:59:59.000Z

    R. C. Eberhart (ed), Heat transfer in medicine and biology.Convective and radiative heat transfer coefficients forbetween convective heat transfer and mass transfer

  3. Heat Waves, Global Warming, and Mitigation

    E-Print Network [OSTI]

    Carlson, Ann E.

    2008-01-01T23:59:59.000Z

    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

  4. Heat transfer probe

    DOE Patents [OSTI]

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

    2006-10-10T23:59:59.000Z

    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.

  5. Superradiant Quantum Heat Engine

    E-Print Network [OSTI]

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

    2015-04-22T23:59:59.000Z

    Quantum physics revolutionized classical disciplines of mechanics, statistical physics, and electrodynamics. 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 quantum regimes. Development of quantum heat engines (QHEs) requires emerging field of quantum thermodynamics. Studies of QHEs debate whether quantum coherence can be used as a resource. We explore an alternative where it can function as an effective 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 output becomes proportional to the square of the number of the atoms. In addition to practical value of cranking up QHE, our result is a fundamental difference of a quantum fuel from its classical counterpart.

  6. Optical heat flux gauge

    DOE Patents [OSTI]

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

    1991-04-09T23:59:59.000Z

    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.

  7. Heat and mass transfer considerations in advanced heat pump systems

    SciTech Connect (OSTI)

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

    1992-08-01T23:59:59.000Z

    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.

  8. Heat and mass transfer considerations in advanced heat pump systems

    SciTech Connect (OSTI)

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

    1992-01-01T23:59:59.000Z

    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.

  9. Characterization of industrial process waste heat and input heat streams

    SciTech Connect (OSTI)

    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

    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)

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

    SciTech Connect (OSTI)

    Ashdown, BG

    2004-08-04T23:59:59.000Z

    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

  11. Heat Pump Strategies and Payoffs 

    E-Print Network [OSTI]

    Gilbert, J. S.

    1982-01-01T23:59:59.000Z

    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...

  12. Industrial Heat Pump Case Study

    E-Print Network [OSTI]

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

    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...

  13. Heat Pump Strategies and Payoffs

    E-Print Network [OSTI]

    Gilbert, J. S.

    1982-01-01T23:59:59.000Z

    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...

  14. Energy 101: Geothermal Heat Pumps

    ScienceCinema (OSTI)

    None

    2013-05-29T23:59:59.000Z

    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.

  15. Energy 101: Geothermal Heat Pumps

    SciTech Connect (OSTI)

    None

    2011-01-01T23:59:59.000Z

    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.

  16. Industrial Heat Recovery - 1982

    E-Print Network [OSTI]

    Csathy, D.

    1982-01-01T23:59:59.000Z

    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...

  17. Self-Heating Effects in GaN/AlGaN Heterostructure Field-Effect Transistors and Device Structure Optimization

    E-Print Network [OSTI]

    Self-Heating Effects in GaN/AlGaN Heterostructure Field-Effect Transistors and Device Structure time, performance of these devices has been limited by self-heating and other problems associated-3]. At the same time, performance of these devices has been limited by self-heating and other problems associated

  18. Period Change of Eclipsing Binaries from the ASAS Catalog

    E-Print Network [OSTI]

    Radoslaw Poleski; Bogumil Pilecki

    2006-07-10T23:59:59.000Z

    We present a preliminary statistical analysis of a period change of eclipsing binaries from the ASAS Catalog of Variable Stars. For each contact and semidetached system brighter than 13.3$mag$ (in V) with a period shorter than 0.4 days and at least 300 observation points we have found an angular velocity $\\omega$ and its time derivative $\\frac{d\\omega}{dt}$. According to our accuracy there is no evidence that average $\\frac{d\\omega}{dt}$ differs from 0. Light curves for selected stars are presented.

  19. Phase transitions in full counting statistics for periodic pumping

    E-Print Network [OSTI]

    Dmitri A. Ivanov; Alexander G. Abanov

    2010-07-16T23:59:59.000Z

    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.

  20. Fluid Bed Waste Heat Boiler Operating Experience in Dirty Gas Streams

    E-Print Network [OSTI]

    Kreeger, A. H.

    FLUID BED WASTE HEAT BOILER OPERATING EXPERIENCE IN DIRTY GAS STREAMS Alan H. Kreeger. Aerojet Energy Conversion Company. Sacramento. California ABSTRACT The first industrial fluid bed waste heat boiler in the U. S. is operating... on an aluminium melting furnace at the ALCOA Massena Integrated Aluminum Works in upstate New York. Waste heat from an aluminum melting furnace is captured for general plant use for the first time in this plant. It is accomplished with advanced fluid bed heat...

  1. Investigation of combined heat and mass transfer from a wet heat exchanger. Part 2. Experimental results and operational characteristics of heat exchangers in dry/wet operations

    SciTech Connect (OSTI)

    Hauser, S.G.; Kreid, D.K.; Johnson, B.M.

    1981-04-01T23:59:59.000Z

    This second part of a two-part paper summarizes the experimental evaluation of a plate finned heat exchanger both with and without the surface wetted by a flowing film of water. The results indicate an increase in heat transfer during wet operation of two to five times over that of dry operation for the same meteorological conditions. The deluge model is shown to accurately predict the wet performance using an experimentally determined deluge film coefficient and the dry performance characteristics.

  2. Heating 7.2 user`s manual

    SciTech Connect (OSTI)

    Childs, K.W.

    1993-02-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Valant, Michael Eric

    1995-01-01T23:59:59.000Z

    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...

  4. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation,Pillar Group BVSPElectrtyUsePercPrinters Jump to: navigation,Information

  5. Absorption-heat-pump system

    DOE Patents [OSTI]

    Grossman, G.; Perez-Blanco, H.

    1983-06-16T23:59:59.000Z

    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.

  6. Seismic isolation of two dimensional periodic foundations

    SciTech Connect (OSTI)

    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

    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.

  7. Desiccant-based, heat-actuated cooling assessment for DHC (District Heating and Cooling) systems

    SciTech Connect (OSTI)

    Patch, K.D.; DiBella, F.A.; Becker, F.E.

    1990-07-01T23:59:59.000Z

    An assessment has been completed of the use of desiccant-based, heat-actuated cooling for District Heating and Cooling (DHC) systems, showing that such desiccant-based cooling (DBC) systems are generally applicable to District Heating (DH) systems. Since the DH system only has to supply hot water (or steam) to its customers, systems that were designed as conventional two-pipe DH systems can now be operated as DHC systems without major additional capital expense. Desiccant-based DHC systems can be operated with low-grade DH-supplied heat, at temperatures below 180{degree}F, without significant loss in operating capacity, relative to absorption chillers. During this assessment, a systems analysis was performed, an experimental investigation was conducted, developmental requirements for commercializing DBC systems were examined, and two case studies were conducted. As a result of the case studies, it was found that the operating cost of a DBC system was competitive with or lower than the cost of purchasing DHC-supplied chilled water. However, because of the limited production volume and the current high capital costs of desiccant systems, the payback period is relatively long. In this regard, through the substitution of low-cost components specifically engineered for low-temperature DHC systems, the capital costs should be significantly reduced and overall economics made attractive to future users. 17 figs.

  8. Modeling solar coronal bright point oscillations with multiple nanoflare heated loops

    E-Print Network [OSTI]

    Chandrashekhar, K

    2015-01-01T23:59:59.000Z

    Intensity oscillations of coronal bright points (BPs) have been studied for past several years. It has been known for a while that these BPs are closed magnetic loop like structures. However, initiation of such intensity oscillations is still an enigma. There have been many suggestions to explain these oscillations, but modeling of such BPs have not been explored so far. Using a multithreaded nanoflare heated loop model we study the behavior of such BPs in this work. We compute typical loop lengths of BPs using potential field line extrapolation of available data (Chandrashekhar et al. 2013), and set this as the length of our simulated loops. We produce intensity like observables through forward modeling and analyze the intensity time series using wavelet analysis, as was done by previous observers. The result reveals similar intensity oscillation periods reported in past observations. It is suggested these oscillations are actually shock wave propagations along the loop. We also show that if one considers di...

  9. MILLIHERTZ QUASI-PERIODIC OSCILLATIONS AND THERMONUCLEAR BURSTS FROM TERZAN 5: A SHOWCASE OF BURNING REGIMES

    SciTech Connect (OSTI)

    Linares, M.; Chakrabarty, D. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, Cambridge, MA 02139 (United States); Altamirano, D. [Astronomical Institute 'Anton Pannekoek', University of Amsterdam and Center for High-Energy Astrophysics, P.O. BOX 94249, 1090 GE Amsterdam (Netherlands); Cumming, A. [Department of Physics, McGill University, 3600 Rue University, Montreal, QC H3A 2T8 (Canada); Keek, L. [School of Physics and Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States)

    2012-04-01T23:59:59.000Z

    We present a comprehensive study of the thermonuclear bursts and millihertz quasi-periodic oscillations (mHz QPOs) from the neutron star (NS) transient and 11 Hz X-ray pulsar IGR J17480-2446, located in the globular cluster Terzan 5. The increase in burst rate that we found during its 2010 outburst, when persistent luminosity rose from 0.1 to 0.5 times the Eddington limit, is in qualitative agreement with thermonuclear burning theory yet contrary to all previous observations of thermonuclear bursts. Thermonuclear bursts gradually evolved into a mHz QPO when the accretion rate increased, and vice versa. The mHz QPOs from IGR J17480-2446 resemble those previously observed in other accreting NSs, yet they feature lower frequencies (by a factor {approx}3) and occur when the persistent luminosity is higher (by a factor 4-25). We find four distinct bursting regimes and a steep (close to inverse cubic) decrease of the burst recurrence time with increasing persistent luminosity. We compare these findings to nuclear burning models and find evidence for a transition between the pure helium and mixed hydrogen/helium ignition regimes when the persistent luminosity was about 0.3 times the Eddington limit. We also point out important discrepancies between the observed bursts and theory, which predicts brighter and less frequent bursts, and suggest that an additional source of heat in the NS envelope is required to reconcile the observed and expected burst properties. We discuss the impact of NS magnetic field and spin on the expected nuclear burning regimes, in the context of this particular pulsar.

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

    SciTech Connect (OSTI)

    Not Available

    1993-12-31T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    NONE

    1996-12-31T23:59:59.000Z

    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.

  12. 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)

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

    2013-04-15T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Huang, Y.; Sun, D.

    2006-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Huang, Y.; Sun, D.

    2006-01-01T23:59:59.000Z

    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...

  15. Development of a Heat Transfer Model for the Integrated Facade Heating

    E-Print Network [OSTI]

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

    2007-01-01T23:59:59.000Z

    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...

  16. Development of a Heat Transfer Model for the Integrated Facade Heating 

    E-Print Network [OSTI]

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

    2007-01-01T23:59:59.000Z

    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...

  17. CONTROL SYSTEM FOR SOLAR HEATING and COOLING

    E-Print Network [OSTI]

    Dols, C.

    2010-01-01T23:59:59.000Z

    solar heated, boosted, or heated entirely in the auxiliary heater)for the solar-heated hot water. This heater can be seen insolar heating and cooling system, showing plumbing runs containing solenoid valves, auxiliary heater (

  18. Visual Simulation of Heat Shimmering and Mirage

    E-Print Network [OSTI]

    Mueller, Klaus

    and the surrounding air. We introduce a heat transfer model between the heat source objects and the ambient flow the heat sources to the ambient flow. Although heat transfer modeling has been used before in computer

  19. Heat Supply Who What Where and -Why

    E-Print Network [OSTI]

    Columbia University

    ................................................. 6 District-heating (DH) supply: key figures .............................. 6 What is biomass Geothermics ..........................................................................11 Waste for heat supplyHeat Supply in Denmark Who What Where and - Why #12;Title: Heat Supply in Denmark - Who What Where

  20. absorption heat: Topics by E-print Network

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

    drive compressor heat pump; (3) absorption heat pump; (4) high temperature heat powered compressor heat pump; (5) reverse absorption heat... Erickson, D. C. 1983-01-01 26...

  1. apparent molal 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...

  2. 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...

  3. Heat-treatment with induction heating of pipes within the pipe welding mill

    SciTech Connect (OSTI)

    Zgura, A.A.; Krichevskii, E.M.; Rudenko, V.A.; Lysyak, A.V.; Kumanev, V.A.

    1988-01-01T23:59:59.000Z

    The parameters of induction heat-treatment were determined for pipes from steels 10Kh18N10T and 12Kh18N10T. Mechanical properties of the base metal and the weld were determined by metallography. Induction heat treatment of corrosion-resistant steel pipes in the line of an argon-arc welding mill was found to produce a fine-grain structure of the base metal and weld, ensured that the mechanical properties satisfied all specifications, reduced time and consumption of the etching solution during chemical processing, required no additional personnel, reduced oxidation of the metal and saved energy.

  4. Heat Transfer in Complex Fluids

    SciTech Connect (OSTI)

    Mehrdad Massoudi

    2012-01-01T23:59:59.000Z

    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

  5. Fully Polynomial Time Approximation Schemes for Stochastic ...

    E-Print Network [OSTI]

    2014-09-03T23:59:59.000Z

    Jun 13, 2013 ... In each time period, she can consume some of her capital, and the ... utility is derived from her consumption based on an underlying utility ...

  6. District heating feasibility, Industrial Corridor, Jamestown, New York

    SciTech Connect (OSTI)

    Not Available

    1988-06-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2006-01-01T23:59:59.000Z

    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.

  8. Optimized Periodic Control of Chaotic Systems

    E-Print Network [OSTI]

    Robert Mettin; Thomas Kurz

    1995-05-09T23:59:59.000Z

    In this work, we demonstrate the open-loop control of chaotic systems by means of optimized periodic signals. The use of such signals enables us to reduce control power significantly in comparison to simple harmonic perturbations. It is found that the stabilized periodic dynamics can be changed by small, specific alterations of the control signal. Thus, low power switching between different periodic states can be achieved without feedback. The robustness of the proposed control method against noise is discussed.

  9. 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.

  10. 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...

  11. 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...

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

    SciTech Connect (OSTI)

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

    1999-09-01T23:59:59.000Z

    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.

  13. Pricing Conspicuous Consumption Products in Recession Periods ...

    E-Print Network [OSTI]

    2012-09-26T23:59:59.000Z

    cally used in chemical engineering, e.g., to avoid irreversible reactions in ... Our basic problem is based on an economic setting with a recession period followed.

  14. Solar heated rotary kiln

    DOE Patents [OSTI]

    Shell, Pamela K. (Tracy, CA)

    1984-01-01T23:59:59.000Z

    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.

  15. Gelling by Heating

    E-Print Network [OSTI]

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

    2013-03-11T23:59:59.000Z

    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.

  16. Heat Transfer Technology

    E-Print Network [OSTI]

    Lefevre, M. R.

    1984-01-01T23:59:59.000Z

    crossflow and counterflow plume. 3) COMBINATION OF HET AND DRY TOWERS When there is not enough water available to provide the makeup for a conventional wet cooling tower, the only solution is to use "DRY" cooling to dissipate part of the heat load. a... 11. The water is cooled first in the DRY section because DRY cooling is much more expensive than WET cooling and this arrangement leads to the smallest DRY tower. It must also be kept in mind that the DRY tower has a physical cooling limit equal...

  17. Combined Heat and Power

    Office of Environmental Management (EM)

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 1112011AT&T, Inc.'sEnergyTexas1. FeedstockCLEANSprings Gets anColoring andCombined Heat

  18. ARM - Atmospheric Heat Budget

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearchSOLICITATIONIMODI FICATION OFMaterialsAnnual Reports27,ListAtmospheric Heat

  19. Heat Pump Water Heaters

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cn SunnybankD.jpgHanfordDepartment of EnergyHearingsWater Heating »

  20. Heat Source Lire,

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cn SunnybankD.jpgHanfordDepartment of EnergyHearingsWater Heating