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Note: This page contains sample records for the topic "time period heating" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
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1

Climatological Time Series with Periodic Correlation  

Science Conference Proceedings (OSTI)

Many climatological time series display a periodic correlation structure. This paper examines three issues encountered when analyzing such time series: detection of periodic correlation, modeling periodic correlation, and trend estimation under ...

Robert Lund; Harry Hurd; Peter Bloomfield; Richard Smith

1995-11-01T23:59:59.000Z

2

Property:TimePeriod | Open Energy Information  

Open Energy Info (EERE)

TimePeriod TimePeriod Jump to: navigation, search This is a property of type String. Pages using the property "TimePeriod" Showing 25 pages using this property. (previous 25) (next 25) 0 0.4 kV remote control (Smart Grid Project) + Not available + 2 220 kV SSSC device for power flow control (Smart Grid Project) + Jul 2009 Jul 2014 + A A complete and normalized 61850 substation (Smart Grid Project) + Oct 2009 Dec 2015 + ADELE Project AACAES (Smart Grid Project) + Dec 2009 Dec 2013 + AFTER A Framework for electrical power sysTems vulnerability identification, dEfense and Restoration (Smart Grid Project) + 2011-2014 + AFTER A Framework for electrical power sysTems vulnerability identification, dEfense and Restoration (Smart Grid Project) (Belgium) + 2011-2014 +

3

Four Time Periods - Energy Information Administration  

U.S. Energy Information Administration (EIA)

... we will be seeing a downward trend in differentials as time moves on. We expect the recent upturn in the light-heavy differentials to be ...

4

Periodic solution of single population models on time scales  

Science Conference Proceedings (OSTI)

By using the calculus on time scales, we study and establish criterion for the existence of periodic solutions of some scalar dynamical equations on time scales. The existence of periodic solutions for some concrete well-known single population models ... Keywords: Coincidence degree theory, Logistic equations, Periodic solutions, Time scales

Jimin Zhang; Meng Fan; Huaiping Zhu

2010-08-01T23:59:59.000Z

5

Particle energization through time-periodic helical magnetic fields  

E-Print Network (OSTI)

We solve for the motion of charged particles in a helical time-periodic ABC (Arnold-Beltrami-Childress) magnetic field. The magnetic field lines of a stationary ABC field with $A=B=C=1$ are chaotic, and we show that the motion of a charged particle in such a field is also chaotic at late time with positive Lyapunov exponent. We further show that in time-periodic (frequency $\\omega$) ABC fields the kinetic energy of a charged particle can increase indefinitely with time. At late times the mean kinetic energy grows as a power law in time with exponent $\\xi$ that approaches unity. For an initial distribution of particles, whose kinetic energy is uniformly distributed within some interval, the PDF of kinetic energy is, at late time, close to a Gaussian but with steeper tails.

Dhrubaditya Mitra; Axel Brandenburg; Brahmananda Dasgupta; Eyvind Niklasson; Abhay Ram

2013-06-01T23:59:59.000Z

6

Transmission thresholds in time-periodically driven nonlinear disordered systems  

E-Print Network (OSTI)

We study energy propagation in locally time-periodically driven disordered nonlinear chains. For frequencies inside the band of linear Anderson modes, three different regimes are observed with increasing driver amplitude: 1) Below threshold, localized quasiperiodic oscillations and no spreading; 2) Three different regimes in time close to threshold, with almost regular oscillations initially, weak chaos and slow spreading for intermediate times, and finally strong diffusion; 3) Immediate spreading for strong driving. The thresholds are due to simple bifurcations, obtained analytically for a single oscillator, and numerically as turning-points of the nonlinear response manifold for a full chain. Generically, the threshold is nonzero also for infinite chains.

Magnus Johansson; Georgios Kopidakis; Stefano Lepri; Serge Aubry

2008-12-18T23:59:59.000Z

7

Flow and heat transfer in a curved pipe with periodically varying curvature  

SciTech Connect

A numerical analysis is carried out for the study of the flow and heat transfer for a laminar flow in a pipe with periodically varying finite (not very small) curvature. The effects of the flow rate (Re), the Prandtl number (Pr), the pipe-period ({kappa}) and the pipe-amplitude (a) on the heat transfer ratio (heat transfer of curved pipe to straight pipe) are studied. The results show that an increase in the amplitude and/or a decrease in the wavelength of a periodic wavy pipe can enhance the heat transfer rate significantly. The ratio of the heat transfer ratio to the friction ratio is greater than one which means a net benefit of heat transfer enhancement.

Yang, R.; Chang, S.F.; Wu, W.

2000-01-01T23:59:59.000Z

8

The Time-varying Characteristics of the Meridional Ekman Heat Transport for the World Ocean  

Science Conference Proceedings (OSTI)

The time-varying meridional Ekman heat transport for the World Ocean is calculated for the 30-year period 1960–1989 using wind stress and sea surface temperature data from the Comprehensive Ocean–Atmosphere Data Set The average monthly heat ...

David Adamec; Michele M. Rienecker; Jeffrey M. Yukovich

1993-12-01T23:59:59.000Z

9

Time-Varying z-Transform for the Analysis of Discrete-Time Linear Time Periodic Systems  

Science Conference Proceedings (OSTI)

This article deals with a new representation of linear discrete-time periodic systems. This representation, based on the time-varying z-transform, turns out to be highly efficient in the field of automatic control, when an appropriate choice of ... Keywords: Nyquist criterion, final value theorem, initial value theorem, linear discrete-time periodic systems, time-varying z-transform, time-varying frequency response, time-varying systems

A. Garcia Iturricha; J. Sabatier; A. Oustaloup

2003-07-01T23:59:59.000Z

10

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

E-Print Network (OSTI)

??The effect of unsteady periodic wakes on heat transfer and boundary layer transition was investigated on a constant curvature heat transfer curved plate in a… (more)

Wright, Lance Cole

2012-01-01T23:59:59.000Z

11

Inverse problem of time-dependent heat sources numerical reconstruction  

Science Conference Proceedings (OSTI)

Abstract: This work studies the inverse problem of reconstructing a time-dependent heat source in the heat conduction equation using the temperature measurement specified at an internal point. Problems of this type have important applications in several ... Keywords: 35R30, 49J20, Green function, Heat source, Inverse problem, Landweber iteration, Numerical results

Liu Yang; Mehdi Dehghan; Jian-Ning Yu; Guan-Wei Luo

2011-04-01T23:59:59.000Z

12

Development of periodic response factors for use with the radiant time series method  

SciTech Connect

Harris and McQuiston (1988) developed conduction transfer function (CTF) coefficients corresponding to 41 representative wall assemblies and 42 representative roof assemblies for use with the transfer function method (TFM). They also developed a grouping procedure that allows design engineers to determine the correct representative wall or roof assembly that most closely matches a specific wall or roof assembly. The CTF coefficients and the grouping procedure have been summarized in the ASHRAE Handbook--Fundamentals (1989, 1993, 1997) and the ASHRAE Cooling and Heating Load Calculation Manual, second edition. More recently, a new, simplified design cooling load calculation procedure, the radiant time series method (RTSM), has been developed. The RTSM uses periodic response factors to model transient conductive heat transfer. While not a true manual load calculation procedure, it is quite feasible to implement the RTSM in a spreadsheet. To be useful in such an environment, it would be desirable to have a pre-calculated set of periodic response factors. Accordingly, a set of periodic response factors has been calculated and is presented in this paper.

Spitler, J.D.; Fisher, D.E.

1999-07-01T23:59:59.000Z

13

Changepoint Detection in Periodic and Autocorrelated Time Series  

Science Conference Proceedings (OSTI)

Undocumented changepoints (inhomogeneities) are ubiquitous features of climatic time series. Level shifts in time series caused by changepoints confound many inference problems and are very important data features. Tests for undocumented ...

Robert Lund; Xiaolan L. Wang; Qi Qi Lu; Jaxk Reeves; Colin Gallagher; Yang Feng

2007-10-01T23:59:59.000Z

14

Property:Building/SPPurchasedEngyForPeriodMwhYrDstrtHeating | Open Energy  

Open Energy Info (EERE)

SPPurchasedEngyForPeriodMwhYrDstrtHeating SPPurchasedEngyForPeriodMwhYrDstrtHeating Jump to: navigation, search This is a property of type String. District heating Pages using the property "Building/SPPurchasedEngyForPeriodMwhYrDstrtHeating" Showing 25 pages using this property. (previous 25) (next 25) S Sweden Building 05K0001 + 2067.0 + Sweden Building 05K0002 + 492.2 + Sweden Building 05K0003 + 473.4 + Sweden Building 05K0004 + 1763.0 + Sweden Building 05K0005 + 605.0 + Sweden Building 05K0006 + 1727.0 + Sweden Building 05K0007 + 1448.0 + Sweden Building 05K0008 + 844.0 + Sweden Building 05K0009 + 2176.0 + Sweden Building 05K0010 + 61.0 + Sweden Building 05K0011 + 967.0 + Sweden Building 05K0012 + 1185.0 + Sweden Building 05K0013 + 1704.0 + Sweden Building 05K0014 + 154.0 + Sweden Building 05K0015 + 145.0 +

15

effects of large reductions and heating temperature- times on grain ...  

Science Conference Proceedings (OSTI)

Heating times of 30, 90 and 180 minutes were used to study the effects of long ... make it difficult to predict the flow of materials throughout the constantly .... Transfer times were kept to a minimum by using a furnace located next to the forging equipment. Percent reductions were calculated taking cross-sectional areas of both ...

16

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

E-Print Network (OSTI)

solar space heating system with heat input and building loadBUILDING UNDER HEAT INPUT CONDITIONS FOR ACTIVE SOLAR HEATINGBUILDING UNDER HEAT INPUT CONDITIONS FOR ACTIVE SOLAR HEATING

Warren, Mashuri L.

2013-01-01T23:59:59.000Z

17

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

SciTech Connect

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.

Kurzeja, R.

2010-07-26T23:59:59.000Z

18

Identification of time series model of heat demand using mathematica environment  

Science Conference Proceedings (OSTI)

The paper presents possibility of model design of time series of heat demand course. The course of heat demand and heat consumption can be demonstrated by means of heat demand diagrams. The most important one is the Daily Diagram of Heat Supply (DDHS) ... Keywords: box-jenkins, control algorithms, district heating control, modelling, prediction, time series analysis

Bronislav Chramcov

2011-05-01T23:59:59.000Z

19

Utah State Prison Space Heating with Geothermal Heat Third Semi-Annual Report for the Period January 1981 - July 1981  

DOE Green Energy (OSTI)

Facing certain cost overruns and lacking information about the long term productivity of the Crystal Hot Springs geothermal resource, costs of construction for the geothermal retrofit, and the method of disposal of geothermal waste water, the Energy Office embarked on a strategy that would enable the project participants to develop accurate cost information on the State Prison Space Heating Program through the completion of Task 5-Construction. The strategy called for: (1) Completion of the resource assessment to determine whether test well USP/TH-1 could be used as a production well. If well USP/TH-1 was found to have sufficient production capacity, money would not have to be expended on drilling another production well. (2) Evaluation of disposal alternatives and estimation of the cost of each alternative. There was no contingency in the original budget to provide for a reinjection disposal system. Cooperative agreement DE EC07-ET27027 indicated that if a disposal system requiring reinjection was selected for funding that task would be negotiated with DOE and the budget amended accordingly. (3) Completion of the preliminary engineering and design work. Included in this task was a thorough net present value cash flow analysis and an assessment of the technical feasibility of a system retrofit given the production characteristics of well USP/TH-1 . In addition, completion of the preliminary design would provide cost estimates for the construction and commissioning of the minimum security geothermal space heating system. With this information accurate costs for each task would be available, allowing the Energy Office to develop strategies to optimize the use of money in the existing budget to ensure completion of the program. Reported herein is a summary of the work towards the completion of these three objectives conducted during the period of January 1981 through June 1981.

None

1981-11-01T23:59:59.000Z

20

Combined Heat and Power: A Technology Whose Time Has Come  

E-Print Network (OSTI)

grid, the few buildings equipped with Combined Heat andthe grid system. 29 Source: EPA Combined Heat and Powergrid system. 21 Alternatively, a CHP system collects the wasted heat

Ferraina, Steven

2014-01-01T23:59:59.000Z

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


21

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

SciTech Connect

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.

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

2002-10-01T23:59:59.000Z

22

Faster and parameter-free discord search in quasi-periodic time series  

Science Conference Proceedings (OSTI)

Time series discord has proven to be a useful concept for time-series anomaly identification. To search for discords, various algorithms have been developed. Most of these algorithms rely on pre-building an index (such as a trie) for subsequences. Users ... Keywords: anomaly detection, minimax search, periodic time series, time series data mining, time series discord

Wei Luo; Marcus Gallagher

2011-05-01T23:59:59.000Z

23

Effective material usage in a compact heat exchanger with periodic micro-channels / Bertus George Kleynhans.  

E-Print Network (OSTI)

??All modern High Temperature Reactors (HTR) thermal cycles have one thing in common: the use of some form of heat exchanger. This heat exchanger is… (more)

Kleynhans, Bertus George

2012-01-01T23:59:59.000Z

24

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

E-Print Network (OSTI)

INPUT CONDITIONS FOR ACTIVE SOLAR HEATING SYSTEMS Mashuri L.CONDITIONS FOR ACTIVE SOLAR HEATING SYSTEMS * • Mashuri L.consists of a hydronic solar space heating system with heat

Warren, Mashuri L.

2013-01-01T23:59:59.000Z

25

Heat capacity, time constant, and sensitivity of Earth’s climate system  

E-Print Network (OSTI)

[1] The equilibrium sensitivity of Earth’s climate is determined as the quotient of the relaxation time constant of the system and the pertinent global heat capacity. The heat capacity of the global ocean, obtained from regression of ocean heat content versus global mean surface temperature, GMST, is 14 ± 6 W a m 2 K 1, equivalent to 110 m of ocean water; other sinks raise the effective planetary heat capacity to 17 ± 7 W a m 2 K 1 (all uncertainties are 1-sigma estimates). The time constant pertinent to changes in GMST is determined from autocorrelation of that quantity over 1880–2004 to be 5 ± 1 a. The resultant equilibrium climate sensitivity, 0.30 ± 0.14 K/(W m 2), corresponds to an equilibrium temperature increase for doubled CO2 of 1.1 ± 0.5 K. The short time constant implies that GMST is in near equilibrium with applied forcings and hence that net climate forcing over the twentieth century can be obtained from the observed temperature increase over this period, 0.57 ± 0.08 K, as 1.9 ± 0.9 W m 2. For this forcing considered the sum of radiative forcing by incremental greenhouse gases, 2.2 ± 0.3 W m 2, and other forcings, other forcing agents, mainly incremental tropospheric aerosols, are inferred to have exerted only a slight forcing over the twentieth century of 0.3 ± 1.0 W m 2.

Stephen E. Schwartz

2007-01-01T23:59:59.000Z

26

An adaptive multitime multigrid algorithm for time-periodic flow simulations  

Science Conference Proceedings (OSTI)

The multiscale behaviour and multidisciplinary nature of rotorcraft aerodynamics has delayed the introduction of CFD techniques for rotorcraft aerodynamics. The numerical dissipation of standard CFD algorithms may destroy tip vortices before blade-vortex ... Keywords: 02.60.Cb, 02.70.Dh, 03.40.Gc, Multigrid, Space-time discontinuous Galerkin method, Time domain, Time-periodic

H. van der Ven

2008-05-01T23:59:59.000Z

27

Determination of a time-dependent heat transfer coefficient from non-standard boundary measurements  

Science Conference Proceedings (OSTI)

In this paper the determination of the time-dependent heat transfer coefficient in one-dimensional transient heat conduction from a non-standard boundary measurement is investigated. For this inverse nonlinear ill-posed problem the uniqueness of the ... Keywords: Boundary element method, Heat conduction, Heat transfer coefficient, Inverse problem

T. T. M. Onyango; D. B. Ingham; D. Lesnic; M. Slodi?ka

2009-01-01T23:59:59.000Z

28

Generation of multiscale magnetic field by parity-invariant time-periodic flows  

E-Print Network (OSTI)

We study generation of magnetic fields involving large spatial scales by time- and space-periodic small-scale parity-invariant flows. The anisotropic magnetic eddy diffusivity tensor is calculated by the standard procedure involving expansion of magnetic modes and their growth rates in power series in the scale ratio. Our simulations, conducted for flows with random harmonic composition and exponentially decaying energy spectra, demonstrate that enlargement of the spatial scale of magnetic field is beneficial for generation by time-periodic flows. However, they turn out, in general, to be less efficient dynamos, than steady flows.

V. A. Zheligovsky; O. M. Podvigina

2002-07-28T23:59:59.000Z

29

Locking-time and Information Capacity in CML with Statistical Periodicity  

E-Print Network (OSTI)

In this work we address the statistical periodicity phenomenon on a coupled map lattice. The study was done based on the asymptotic binary patterns. The pattern multiplicity gives us the lattice information capacity, while the entropy rate allows us to calculate the locking-time. Our results suggest that the lattice has low locking-time and high capacity information when the coupling is weak. This is the condition for the system to reproduce a kind of behavior observed in neural networks.

Romeu Miqueias Szmoski; Rodrigo Frehse Pereira; Fabiano Alan Serafim Ferrari; Sandro Ely de Souza Pinto

2010-11-24T23:59:59.000Z

30

Tunneling of Massive Dirac Fermions in Graphene through Time-periodic Potential  

E-Print Network (OSTI)

The energy spectrum of graphene sheet with a single barrier structure having a time periodic oscillating height and subjected to magnetic field is analyzed. The corresponding transmission is studied as function of the obtained energy and the potential parameters. Quantum interference within the oscillating barrier has an important effect on quasiparticles tunneling. In particular the time-periodic electromagnetic field generates additional sidebands at energies \\epsilon + l\\hbar \\omega (l=0,\\pm 1, \\cdots) in the transmission probability originating from the photon absorption or emission within the oscillating barrier. Due to numerical difficulties in truncating the resulting coupled channel equations we limited ourselves to low quantum channels, i.e. l=0,\\pm 1.

Ahmed Jellal; Miloud Mekkaoui; El Bouazzaoui Choubabi; Hocine Bahlouli

2013-11-29T23:59:59.000Z

31

Heat Kernel Short-Time Expansion within the Scope of Feynman-Kac Formula  

Science Conference Proceedings (OSTI)

The paper gives an outlook of the stochastic approach to derivation of heat kernel short-time asymptotic expansion and to effective evaluation of corresponding coefficients.

Stepin, S. A.; Rejrat, A. J. [Institute of Mathematics, University of Bialystok, Akademicka 2, 15-267 Bialystok (Poland)

2010-11-25T23:59:59.000Z

32

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

Science Conference Proceedings (OSTI)

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

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

2012-11-01T23:59:59.000Z

33

Leakage-Aware Reallocation for Periodic Real-Time Tasks on Multicore Processors  

E-Print Network (OSTI)

It is an increasingly important issue to reduce the energy consumption of computing systems. In this paper, we consider partition based energy-aware scheduling of periodic real-time tasks on multicore processors. The scheduling exploits dynamic voltage scaling (DVS) and core sleep scheduling to reduce both dynamic and leakage energy consumption. If the overhead of core state switching is non-negligible, however, the performance of this scheduling strategy in terms of energy efficiency might degrade. To achieve further energy saving, we extend the static task scheduling with run-time task reallocation. The basic idea is to aggregate idle time among cores so that as many cores as possible could be put into sleep in a way that the overall energy consumption is reduced. Simulation results show that the proposed approach results in up to 20% energy saving over traditional leakage-aware DVS.

Huang, Hongtao; Wang, Jijie; Lei, Siyu; Wu, Guowei

2010-01-01T23:59:59.000Z

34

Reactor Decay Heat in {sup 239}Pu: Solving the {gamma} Discrepancy in the 4-3000-s Cooling Period  

Science Conference Proceedings (OSTI)

The {beta} feeding probability of {sup 102,104,105,106,107}Tc, {sup 105}Mo, and {sup 101}Nb nuclei, which are important contributors to the decay heat in nuclear reactors, has been measured using the total absorption technique. We have coupled for the first time a total absorption spectrometer to a Penning trap in order to obtain sources of very high isobaric purity. Our results solve a significant part of a long-standing discrepancy in the {gamma} component of the decay heat for {sup 239}Pu in the 4-3000 s range.

Algora, A. [IFIC - CSIC-Univ. Valencia, Valencia (Spain); Institute of Nuclear Research, Debrecen (Hungary); Jordan, D.; Tain, J. L.; Rubio, B.; Agramunt, J.; Perez-Cerdan, A. B.; Molina, F.; Caballero, L.; Nacher, E. [IFIC - CSIC-Univ. Valencia, Valencia (Spain); Krasznahorkay, A.; Hunyadi, M. D.; Gulyas, J.; Vitez, A.; Csatlos, M.; Csige, L. [Institute of Nuclear Research, Debrecen (Hungary); Aeysto, J.; Penttilae, H.; Moore, I. D.; Eronen, T.; Jokinen, A. [University of Jyvaeskylae, Jyvaeskylae (Finland)

2010-11-12T23:59:59.000Z

35

Evaluation of Methodologies for Real-Time Incremental Heat Rate Determination  

Science Conference Proceedings (OSTI)

Reduced staffing, tighter budgets, ISOs, and increased competition have created the need for maintaining up-to-date incremental heat rate information. Combining recent advances in analytics with modern performance monitoring packages and data historians may provide the capability for closer-to-real-time incremental heat rate determination. Many power generating companies either rely on historic data or slow and labor intensive testing to establish incremental heat rate curves. Those curves are ...

2013-11-26T23:59:59.000Z

36

Growth mechanism of photoreduced silver nanostructures on periodically proton exchanged lithium niobate: Time and concentration dependence  

SciTech Connect

Photodeposition of metallic nanostructures onto ferroelectric surfaces, which have been chemically patterned using a proton exchange process, has recently been demonstrated. By varying the molar concentration of the AgNO{sub 3} solution and the illumination time, one can determine the initial nucleation sites, control the rate of nucleation and the height of silver nanostructures formed, and study the mechanisms by which these processes occurs. The nanoparticles are found to deposit preferentially in the boundary between ferroelectric and proton exchanged regions, in an area proton exchanged via lateral diffusion under the masking layer used for chemical patterning, consistent with our previous results. Using a short illumination time (3 min), we are able to determine that the initial nucleation of the silver nanostructure, having a width of 0.17 {+-} 0.02 {mu}m and a height of 1.61 {+-} 0.98 nm, occurs near the edge of the reactive ion etched area within this lateral diffusion region. Over longer illumination times (15 min), we find that the silver deposition has spread to a width of 1.29 {+-} 0.06 {mu}m, extending across the entire lateral diffusion region. We report that at a high molar concentration of AgNO{sub 3} (10{sup -2} M), the amount of silver deposition for 5 min UV illumination is greater (2.88 {+-} 0.58 nm) compared to that at low (10{sup -4} M) concentrations (0.78 {+-} 0.35 nm), however, this is not the case for longer time periods. With increasing illumination time (15 min), experiments at 10{sup -4} M had greater overall deposition, 6.90 {+-} 1.52 nm, compared to 4.50 {+-} 0.76 nm at 10{sup -2} M. For longer exposure times (30 min) at 10{sup -2} M, the nanostructure height is 4.72 {+-} 0.59 nm, suggesting a saturation in the nanostructure height. The results are discussed in terms of the electric double layer that forms at the crystal surface. There is an order of magnitude difference between the Debye lengths for 10{sup -2} and 10{sup -4} M solutions, i.e., 3.04 vs. 30.40 nm, which suggests the Debye length plays a role in the availability of Ag{sup +} ions at the surface.

Craig Carville, N.; Denning, Denise; Rodriguez, Brian J. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland) [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4 (Ireland); Manzo, Michele; Gallo, Katia [Department of Applied Physics, KTH-Royal Institute of Technology, Roslagstullbacken 21, 106 91 Stockholm (Sweden)] [Department of Applied Physics, KTH-Royal Institute of Technology, Roslagstullbacken 21, 106 91 Stockholm (Sweden)

2013-05-14T23:59:59.000Z

37

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

E-Print Network (OSTI)

The cost of energy consuming of heating system takes a great proportion in the total cost of realty management. This article,focuses or the drawbacks of conventional heating system, analyzes the data collected from actual practices and proposes 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 the cost of energy consuming.

Zhang, J.

2006-01-01T23:59:59.000Z

38

PERIODIC HEAT REPORT  

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

Vessel Temp Walls, deg C 59.00 Vessel Setpoint Walls 60.00 Power, kW 25.00 Breaker OK Scanner OK Highest Temp Last Fault 138.00 TripHigh tc Date MO:DAY 8.00: 2.00...

39

Choosing beacon periods to improve response times for wireless HTTP clients  

Science Conference Proceedings (OSTI)

The IEEE 802.11 wireless LAN standard power-saving mode (PSM) allows the network interface card (NIC) to periodically sleep between receiving data. In this paper, we show that 802.11 PSM performs poorly due to the fact that an access point is unable ... Keywords: beacon periods, wireless access

Suman Nath; Zachary Anderson; Srinivasan Seshan

2004-10-01T23:59:59.000Z

40

Residence Time and Heat Transfer When Water Droplets Hit a Scalding Ji Yong Park*  

E-Print Network (OSTI)

1 Residence Time and Heat Transfer When Water Droplets Hit a Scalding Surface Ji Yong Park* , Chang a series of water droplets impact a smooth surface whose temperature exceeds the boiling point. The volume of the individual water droplets is 10 nL, the time between droplets is 0.3 ms, and the number of water droplets

Cahill, David G.

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


41

Time-resolved ellipsometry for studies of heat transfer at liquid/solid and gas/solid interfaces  

E-Print Network (OSTI)

partly controlled by the rate of heat transfer across the interface. Heat moving from the metal film is heated by 10 K using an ultrafast optical pump pulse; the subsequent changes of the phase differenceTime-resolved ellipsometry for studies of heat transfer at liquid/solid and gas/solid interfaces

Granick, Steve

42

Influence of Choice of Time Period on Global Surface Temperature Trend Estimates  

Science Conference Proceedings (OSTI)

Annual global surface temperature and global land surface temperature trends are calculated for all possible periods of the historical record between 1850 and 2009. Two-dimensional parameter diagrams show the critical influence of the choice of ...

Brant Liebmann; Randall M. Dole; Charles Jones; Ileana Bladé; Dave Allured

2010-11-01T23:59:59.000Z

43

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

E-Print Network (OSTI)

Based on the status quo that conventional energy sources are more and more reduced and environmental pollution is increasingly serious, this paper presents a new model system of conserving energy and environmental protection, namely, a Solar 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 heat collector is solved by latent heat storage. In order to obtain such system running conditions and effects in different heating periods, an experiment has been carried out during the whole heating period in Harbin, China. The experimental results show that this system is much better for heating in initial and late periods than that in middle periods. The average heating coefficient is 6.13 for heating in initial and late periods and 2.94 for heating in middle periods. At the same time, this paper also predicts system running properties in other regions.

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

2006-01-01T23:59:59.000Z

44

Borel summation of the small time expansion of the heat kernel with a vector potential  

E-Print Network (OSTI)

We study the Borel summability of the small time expansion of the heat kernel associated to a first order perturbation of a Laplacian. An explicit formula for this kernel plays a central role. As a consequence, we get a Poisson formula on the torus.

Thierry Harge

2013-02-04T23:59:59.000Z

45

Gang FTP scheduling of periodic and parallel rigid real-time tasks  

E-Print Network (OSTI)

In this paper we consider the scheduling of periodic and parallel rigid tasks. We provide (and prove correct) an exact schedulability test for Fixed Task Priority (FTP) Gang scheduler sub-classes: Parallelism Monotonic, Idling, Limited Gang, and Limited Slack Reclaiming. Additionally, we study the predictability of our schedulers: we show that Gang FJP schedulers are not predictable and we identify several sub-classes which are actually predictable. Moreover, we extend the definition of rigid, moldable and malleable jobs to recurrent tasks.

Goossens, Joël

2010-01-01T23:59:59.000Z

46

Dynamic Scheduling of Skippable Periodic Tasks with Energy Efficiency in Weakly Hard Real-Time System  

E-Print Network (OSTI)

Energy consumption is a critical design issue in real-time systems, especially in battery- operated systems. Maintaining high performance, while extending the battery life between charges is an interesting challenge for system designers. Dynamic Voltage Scaling (DVS) allows a processor to dynamically change speed and voltage at run time, thereby saving energy by spreading run cycles into idle time. Knowing when to use full power and when not, requires the cooperation of the operating system scheduler. Usually, higher processor voltage and frequency leads to higher system throughput while energy reduction can be obtained using lower voltage and frequency. Instead of lowering processor voltage and frequency as much as possible, energy efficient real-time scheduling adjusts voltage and frequency according to some optimization criteria, such as low energy consumption or high throughput, while it meets the timing constraints of the real-time tasks. As the quantity and functional complexity of battery powered porta...

Baskaran, Santhi

2010-01-01T23:59:59.000Z

47

Large-Strain Time-Temperature Equivalence and Adiabatic Heating of Polyethylene  

Science Conference Proceedings (OSTI)

Time-temperature equivalence is a well-known phenomenon in time-dependent material response, where rapid events at a moderate temperature are indistinguishable from some occurring at modest rates but elevated temperatures. However, there is as-yet little elucidation of how well this equivalence holds for substantial plastic strains. In this work, we demonstrate time-temperature equivalence over a large range in a previously studied high-density polyethylene formulation (HDPE). At strain-rates exceeding 0.1/s, adiabatic heating confounds the comparison of nominally isothermal material response, apparently violating time-temperature equivalence. Strain-rate jumps can be employed to access the instantaneous true strain rate without heating. Adiabatic heating effects were isolated by comparing a locus of isothermal instantaneous flow stress measurements from strain-rate jumps up to 1/s with the predicted equivalent states at 0.01/s and 0.001/s in compression. Excellent agreement between the isothermal jump condition locus and the quasi-static tests was observed up to 50% strain, yielding one effective isothermal plastic response for each material for a given time-temperature equivalent state. These results imply that time-temperature equivalence can be effectively used to predict the deformation response of polymers during extreme mechanical events (large strain and high strain-rate) from measurements taken at reduced temperatures and nominal strain-rates in the laboratory.

Furmanski, Jevan [Los Alamos National Laboratory; Brown, Eric [Los Alamos National Laboratory; Cady, Carl M. [Los Alamos National Laboratory

2012-06-06T23:59:59.000Z

48

Gravo-thermodynamics of the Intracluster Medium: negative heat capacity and dilation of cooling time scales  

E-Print Network (OSTI)

The time scale for cooling of the gravitationally bound gaseous intracluster medium (ICM) is not determined by radiative processes alone. If the ICM is in quasi-hydrostatic equilibrium in the fixed gravitational field of the dark matter halo then energy losses incurred by the gravitational potential energy of the gas should also be taken into account. This "gravitational heating" has been known for a while using explicit solutions to the equations of motion. Here, we re-visit this effect by applying the virial theorem to gas in quasi-hydrostatic equilibrium in an external gravitational field, neglecting the gravity of the gas. For a standard NFW form of halo profiles and for a finite gas density, the response of the gas temperature to changes in the total energy is significantly delayed. The effective cooling time could be prolonged by more than an order of magnitude inside the scale radius ($\\rs$) of the halo. Gas lying at a distance twice the scale radius, has negative heat capacity so that the temperature increases as a result of energy losses. Although external heating (e.g. by AGN activity) is still required to explain the lack of cool ICM near the center, the analysis here may circumvent the need for heating in farther out regions where the effective cooling time could be prolonged to become larger than the cluster age and also explains the increase of temperature with radius in these regions.

Adi Nusser

2008-06-12T23:59:59.000Z

49

Delimiting “Thunderstorm Watch” Periods by Real-Time Lightning Location for a Power Utility Company  

Science Conference Proceedings (OSTI)

During times of thunderstorm activity, the power utility serving metropolitan New York enters a potentially costly “thunderstorm watch” mode of operation which is designed to prevent a major power outage caused by lightning. To evaluate the ...

Vincent P. Idone; Richard E. Orville

1990-03-01T23:59:59.000Z

50

Long-time solvability of the Navier-Stokes-Boussinesq equations with almost periodic initial large data  

E-Print Network (OSTI)

We investigate large time existence of solutions of the Navier-Stokes-Boussinesq equations with spatially almost periodic large data when the density stratification is sufficiently large. In 1996, Kimura and Herring \\cite{KH} examined numerical simulations to show a stabilizing effect due to the stratification. They observed scattered two-dimensional pancake-shaped vortex patches lying almost in the horizontal plane. Our result is a mathematical justification of the presence of such two-dimensional pancakes. To show the existence of solutions for large times, we use $\\ell^1$-norm of amplitudes. Existence for large times is then proven using techniques of fast singular oscillating limits and bootstrapping argument from a global-in-time unique solution of the system of limit equations.

Ibrahim, Slim

2011-01-01T23:59:59.000Z

51

Micron-Scale Measurements of Heat Capacity by Time-Domain ...  

Science Conference Proceedings (OSTI)

Presentation Title, Micron-Scale Measurements of Heat Capacity by ... is developed for localized measurement of specific heat capacity with a spatial resolution ...

52

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

Science Conference Proceedings (OSTI)

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

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

2011-06-01T23:59:59.000Z

53

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

Science Conference Proceedings (OSTI)

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

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

2012-04-10T23:59:59.000Z

54

A multiple-relaxation-time lattice Boltzmann model for convection heat transfer in porous media  

E-Print Network (OSTI)

In this paper, a multiple-relaxation-time (MRT) lattice Boltzmann (LB) model is developed for simulating convection heat transfer in porous media at the representative elementary volume scale. In the model, a MRT-LB equation is used to simulate the flow field, while another MRT-LB equation is employed to simulate the temperature field. The effect of the porous media is considered by introducing the porosity into the equilibrium moments, and adding a forcing term to the MRT-LB equation of the flow field in the moment space. The proposed MRT-LB model is validated by numerical simulations of several two-dimensional convection problems in porous media. The numerical results predicted by the present MRT-LB model agree well with those reported in the literature.

Q. Liu; Y. L. He; Q. Li

2013-08-09T23:59:59.000Z

55

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

SciTech Connect

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

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

2011-01-04T23:59:59.000Z

56

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  

DOE Green Energy (OSTI)

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

Rogers, J.; Porter, K.

2012-03-01T23:59:59.000Z

57

Cooperative heat transfer and ground coupled storage system  

DOE Patents (OSTI)

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

Metz, Philip D. (Rocky Point, NY)

1982-01-01T23:59:59.000Z

58

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

Science Conference Proceedings (OSTI)

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

Hudson II, Carl Randy [ORNL

2004-09-01T23:59:59.000Z

59

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

Science Conference Proceedings (OSTI)

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

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

2012-10-10T23:59:59.000Z

60

Time-dependent hydrogen and helium pressure profiles in a long, cryogenically cooled tube, pumped at periodic intervals  

DOE Green Energy (OSTI)

Many particle accelerators and colliders throughout the world make use of superconducting magnets to focus highly relativistic beams. These magnets are cooled to [approximately]4.2[degree]K For practical reasons, the beam pipes, encircled by the magnets, also operate at these cryogenic temperatures. This paper presents a theoretical model for determining pressure profiles, in space and time, stemming from either hydrogen or helium gas leak into the cold-bore tube with appendage pumps located at periodic intervals. It is shown that a wave-like pressure gradient propagates from the leak source at a rate which is dependent on the leak magnitude, gas species, speed and location of appendage pumps, and the geometry and effective roughness of the cold-bore tube. Steady-state, linear pressure gradients eventually equilibrate between the appendage pumps in a magnitude commensurate with both the adsorption isotherm of the species and mass flow in the beam pipe. Results are given for a variety of conditions relevant to the Relativistic Heavy Ion Collider being constructed at Brookhaven, and a general procedure, with expressions, is provided for the making of similar calculations in other installations.

Hobson, J.P. (National Vacuum Technologies, Inc., Ontario (Canada)); Welch, K.M. (Brookhaven National Lab., Upton, NY (United States))

1992-01-01T23:59:59.000Z

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


61

An Extended and More Sensitive Search for Periodicities in Rossi X-ray Timing Explorer/all-sky Monitor X-ray Light Curves  

E-Print Network (OSTI)

We present the results of a systematic search in ~14 years of Rossi X-ray Timing Explorer All-Sky Monitor (ASM) data for evidence of periodicities. Two variations of the commonly used Fourier analysis search method have ...

Levine, Alan M.

62

Optimal Scheduling of Industrial Combined Heat and Power Plants under Time-sensitive Electricity Prices  

E-Print Network (OSTI)

Combined heat and power (CHP) plants are widely used in industrial applications. In the aftermath of the recession, many of the associated production processes are under-utilized, which challenges the competitiveness of chemical companies. However, under-utilization can be a chance for tighter interaction with the power grid, which is in transition to the so-called smart grid, if the CHP plant can dynamically react to time-sensitive electricity prices. In this paper, we describe a generalized mode model on a component basis that addresses the operational optimization of industrial CHP plants. The mode formulation tracks the state of each plant component in a detailed manner and can account for different operating modes, e.g. fuel-switching for boilers and supplementary firing for gas turbines, and transitional behavior. Transitional behavior such as warm and cold start-ups, shutdowns and pre-computed start-up trajectories is modeled with modes as well. The feasible region of operation for each component is described based on input-output relationships that are thermodynamically sound, such as the Willans line for steam turbines. Furthermore, we emphasize the use of mathematically efficient logic constraints that allow solving the large-scale models fast. We provide an industrial case study and study the impact of different scenarios for under-utilization. 1

Sumit Mitra; Ignacioe. Grossmann

2012-01-01T23:59:59.000Z

63

Potential of thermal insulation and solar thermal energy in domestic hot water and space heating and cooling sectors in Lebanon in the period 2010 - 2030.  

E-Print Network (OSTI)

??The potential of thermal insulation and solar thermal energy in domestic water heating, space heating and cooling in residential and commercial buildings Lebanon is studied… (more)

Zaatari, Z.A.R.

2012-01-01T23:59:59.000Z

64

Empirical Models of the Eddy Heat Flux and Vertical Shear on Short Time Scales  

Science Conference Proceedings (OSTI)

The relationship between the eddy heat flux and vertical shear in the extratropical atmosphere is studied by developing various linear stochastic models fitted to the observed January and July Northern Hemispheric data. Models are univariate or ...

Steven J. Ghan

1984-02-01T23:59:59.000Z

65

Modeling the Contribution of the Brussels Heat Island to a Long Temperature Time Series  

Science Conference Proceedings (OSTI)

A mesoscale meteorological model containing a detailed land surface model is used to assess the contribution of urban heating to the temperature record of the national recording station of Belgium in Uccle, near Brussels. The Advanced Regional ...

K. Van Weverberg; K. De Ridder; A. Van Rompaey

2008-04-01T23:59:59.000Z

66

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

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

Spectroscopy of Laser-heated Copper Foils Tuesday, July 16, 2013 - 11:00am SLAC, Conference Room 137-322 Presented by Kelly Cone, PhD Engineering, Dept. of Applied Science,...

67

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

SciTech Connect

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

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

2010-05-01T23:59:59.000Z

68

Use of miniature magnetic sensors for real-time control of the induction heating process  

DOE Patents (OSTI)

A method of monitoring the process of induction heating a workpiece. A miniature magnetic sensor located near the outer surface of the workpiece measures changes in the surface magnetic field caused by changes in the magnetic properties of the workpiece as it heats up during induction heating (or cools down during quenching). A passive miniature magnetic sensor detects a distinct magnetic spike that appears when the saturation field, B.sub.sat, of the workpiece has been exceeded. This distinct magnetic spike disappears when the workpiece's surface temperature exceeds its Curie temperature, due to the sudden decrease in its magnetic permeability. Alternatively, an active magnetic sensor can also be used to measure changes in the resonance response of the monitor coil when the excitation coil is linearly swept over 0-10 MHz, due to changes in the magnetic permeability and electrical resistivity of the workpiece as its temperature increases (or decreases).

Bentley, Anthony E. (Tijeras, NM); Kelley, John Bruce (Albuquerque, NM); Zutavern, Fred J. (Albuquerque, NM)

2002-01-01T23:59:59.000Z

69

The Response Time of the Temperature of the Equatorial Troposphere to ENSO Heating  

Science Conference Proceedings (OSTI)

Air temperature anomalies, averaged over the troposphere to 200 mb and around the earth from 10°S to 10°N, lag the similarly averaged El Nińo–Southern Oscillation (ENSO) atmospheric latent heating anomalies by about one month. Most of the latent ...

Allan J. Clarke; Kwang-Y. Kim

2005-12-01T23:59:59.000Z

70

Fuzzy multi-objective production/distribution planning decisions with multi-product and multi-time period in a supply chain  

Science Conference Proceedings (OSTI)

This work develops a fuzzy multi-objective linear programming (FMOLP) model with piecewise linear membership function to solve integrated multi-product and multi-time period production/distribution planning decisions (PDPD) problems with fuzzy objectives. ... Keywords: Fuzzy multi-objective linear programming, Fuzzy sets, Production/distribution planning decisions, Supply chain management

Tien-Fu Liang

2008-10-01T23:59:59.000Z

71

Chemical heat pump  

DOE Patents (OSTI)

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

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

1980-01-01T23:59:59.000Z

72

Energy Basics: Radiant Heating  

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

very low heat capacity and have the quickest response time of any heating technology. More Information Visit the Energy Saver website for more information about radiant heating...

73

Energy Basics: Radiant Heating  

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

low heat capacity and have the quickest response time of any heating technology. More Information Visit the Energy Saver website for more information about radiant heating in homes...

74

Integrating preconcentrator heat controller  

DOE Patents (OSTI)

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

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

2007-10-16T23:59:59.000Z

75

Active period Sleep period Active period Sleep period Fig. 1. Sleep-awake cycles of SMAC.  

E-Print Network (OSTI)

A cycle Active period Sleep period Active period Sleep period SYNC usage DATA usage time Fig. 1 Yang and Wendi Heinzelman Dept. of Electrical and Computer Engineering, University of Rochester duty cycles. Since a smaller duty cycle leads to a longer network lifetime but lower throughput

Heinzelman, Wendi

76

Chemical heat pump  

DOE Patents (OSTI)

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

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

1984-01-01T23:59:59.000Z

77

Chemical heat pump  

DOE Patents (OSTI)

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

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

1984-01-01T23:59:59.000Z

78

Chemical heat pump  

DOE Patents (OSTI)

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

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

1981-01-01T23:59:59.000Z

79

Chemical heat pump  

DOE Patents (OSTI)

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

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

1984-01-01T23:59:59.000Z

80

Water Heating | OpenEI  

Open Energy Info (EERE)

Water Heating Water Heating Dataset Summary Description Provides total and average household expenditures on energy for water heating in the United States in 2005. Source EIA Date Released September 01st, 2008 (6 years ago) Date Updated January 01st, 2009 (6 years ago) Keywords Energy Expenditures Residential Water Heating Data application/vnd.ms-excel icon 2005_Total.Expenditures.for_.Water_.Heating_EIA.Sep_.2008.xls (xls, 70.1 KiB) application/vnd.ms-excel icon 2005_Avg.Expenditures.for_.Water_.Heating_EIA.Sep_.2008.xls (xls, 69.1 KiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period 2005 License License Other or unspecified, see optional comment below Comment Rate this dataset Usefulness of the metadata Average vote Your vote

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


81

Busy period, time of the first loss of a customer and the number of customers in $ M^{\\varkappa}|G^{\\delta}|1|B$  

E-Print Network (OSTI)

A two-sided exit problem is solved for a difference of a compound Poisson process and a compound renewal process. More precisely, the Laplace transforms of the joint distribution of the first exit time, the value of the overshoot and the value of a linear component at this instant are found. Further, we study the process reflected in its supremum. We determine the main two-boundary characteristics of the process reflected in its supremum. These results are then applied for studying the $ M^{\\varkappa}|G^{\\delta}|1|B$ system. We derive the distribution of a busy period and the numbers of customers in the system in transient and stationary regimes. The advantage is that these results are in a closed form, in terms of resolvent sequences of the process.

Kadankova, Tetyana; Veraverbeke, Noel

2011-01-01T23:59:59.000Z

82

Long Term Geothermal Heat Pump System Ground Loop Heat Exchanger Performance: Field Data from a Quick Service Restaurant Application  

Science Conference Proceedings (OSTI)

This report summarizes measured long-term performance of the ground loop heat exchanger in a geothermal heat pump system in a McDonald's Quick Service Restaurant located in Westland near Detroit, Michigan. Heat build-up in the soil around the heat exchanger over a long period of time has always been a concern, but only limited data has been available in the past. The gradual increase in the return loop temperature over a period of five years is evidence of the heat built up in the ground loop field, whic...

2003-01-22T23:59:59.000Z

83

Geothermal Energy Market Study on the Atlantic Coastal Plain: a review of recent energy price projections for traditional space and process heating fuels in the post-1985 period  

Science Conference Proceedings (OSTI)

The most recent price projections that have been published for distillate heating fuels, natural gas, and electricity are reviewed. The projections include those made by EIA, DOE, BNL, Foster Associates, and SRI International. Projected distillate prices for 1990 range from Brookhaven's worst case real price of $8.80 per million Btu's to EIA's most optimistic case of $4.10 for that year compared to $6.10 prevailing in September 1979. Natural gas prices projected for 1990 fall within a more narrow band ranging up to $4.50 (Brookhaven's basecase) compared to $4.20 in September 1979. Electricity prices projected for 1990 range to $17.00 per million Btu's compared to the September 1979 average price of $15.50. Regional price differentials show the Northeast paying above national average prices for oil, natural gas, and electricity. The West enjoys the lowest energy price levels overall. Oil prices are relatively uniform across the country, while natural gas and electricity prices may vary by more than 50% from one region to another.

Barron, W.

1980-04-01T23:59:59.000Z

84

Production of high-energy chemicals using solar energy heat. Project 8999, final report for the period September 1, 1977--May 31, 1978  

DOE Green Energy (OSTI)

The first phase of a study to identify candidate processes and products suitable for future exploitation using high-temperature solar energy is presented. This phase has been principally analytical, consisting of techno-economic studies, thermodynamic assessments of chemical reactions and processes, and the determination of market potentials for major chemical commodities that use significant amounts of fossil resources today. The objective was to identify energy-intensive processes that would be suitable for the production of chemicals and fuels using solar energy process heat. Of particular importance was the comparison of relative costs and energy requirements for the selected solar product versus costs for the product derived from conventional processing. The assessment methodology used a systems analytical approach to identify processes and products having the greatest potential for solar energy-thermal processing. This approach was used to establish the basis for work to be carried out in subsequent phases of development. It has been the intent of the program to divide the analysis and process identification into the following three distinct areas: (1) process selection, (2) process evaluation, and (3) ranking of processes. Four conventional processes were selected for assessment namely, methanol synthesis, styrene monomer production, vinyl chloride monomer production, and terephthalic acid production.

Dafler, J.R.; Sinnott, J.; Novil, M.; Yudow, B.D.; Rackoff, M.G.

1978-12-01T23:59:59.000Z

85

Greenhouse of an underground heat accumulation system  

SciTech Connect

A greenhouse of an underground heat accumulation system is described wherein the radiant energy of the sun or wasted thermal energy is accumulated in the soil below the floor of the greenhouse over a prolonged period of time, and spontaneous release of the accumulated energy into the interior of the greenhouse begins in the wintertime due to a time lag of heat transfer through the soil. The release of the accumulated energy lasts throughout the winter.

Fujie, K.; Abe, K.; Uchida, A.

1983-11-01T23:59:59.000Z

86

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

Science Conference Proceedings (OSTI)

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.

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

2008-09-15T23:59:59.000Z

87

The NCEP GODAS Ocean Analysis of the Tropical Pacific Mixed Layer Heat Budget on Seasonal to Interannual Time Scales  

Science Conference Proceedings (OSTI)

The mixed layer heat budget in the tropical Pacific is diagnosed using pentad (5 day) averaged outputs from the Global Ocean Data Assimilation System (GODAS), which is operational at the National Centers for Environmental Prediction (NCEP). The ...

Boyin Huang; Yan Xue; Dongxiao Zhang; Arun Kumar; Michael J. McPhaden

2010-09-01T23:59:59.000Z

88

Transient Response to Localized Episodic Heating in the Tropics. Part I: Excitation and Short-Time Near-Field Behavior  

Science Conference Proceedings (OSTI)

The dynamical response to localized, unsteady tropical heating is studied in a stochastic framework. Spectral statistics of the random wave response are derived from those of tropical convection using the primitive equations for a spherical ...

Murry L. Salby; Rolando R. Garcia

1987-01-01T23:59:59.000Z

89

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

E-Print Network (OSTI)

) Co-genera8on of electricity and heat Storage Microgrids2 1. "Systema%c u. A microgrid refers to a "local grid" that can work autonomously from the central

Grossmann, Ignacio E.

90

Space and Time Resolved Measurements of the Heating of Solids to Ten Million Kelvin by a Petawatt Laser  

Science Conference Proceedings (OSTI)

The heating of plane solid targets by the Vulcan petawatt laser at powers of 0.32-0.73 PW and intensities of up to 4 x 10^20 W cm^-2 has been diagnosed with a temporal resolution of 17 ps and a spatial resolution of 30 um, by measuring optical emission from the opposite side of the target to the laser with a streak camera. Second harmonic emission was filtered out and the target viewed at an angle to eliminate optical transition radiation. Spatial resolution was obtained by imaging the emission onto a bundle of fibre optics, arranged into a one-dimensional array at the camera entrance. The results show that a region 160 um in diameter can be heated to a temperature of ~10^7 K (kT/e ~ keV) in solid targets from 10 to 20 um thick and that this temperature is maintained for at least 20 ps, confirming the utility of PW lasers in the study of high energy density physics. Hybrid code modelling shows that magnetic field generation prevents increased target heating by electron refluxing above a certain target thickness and that the absorption of laser energy into electrons entering the solid target was between 15-30%, and tends to increase with laser energy.

Nakatsutsumi, M.; Davies, J.R.; Kodama, R.; Green, J.S.; Lancaster, K.L.; Akli, K.U.; Beg, F.N.; Chen, S.N.; Clark, D.; Freeman, R.R.; Gregory, C.D.; Habara, H.; Heathcote, R.; Hey, D.S.; Highbarger, K.; Jaanimagi, P.; Key, M.H.; Krushelnick, K.; Ma, T.; MacPhee, A.; MacKinnon, A.J.; Nakamura, H.; Stephens, R.B.; Storm, M.; Tampo, M.; Theobald, W.; Van Woerkom, L.; Weber, R.L.; Wei, M.S.; Woolsey, N.C.; Norreys, P.A.

2008-04-29T23:59:59.000Z

91

Specific features in building hardware-software complexes operating in real-time: An example of test rig used in periodic tests of reducers  

Science Conference Proceedings (OSTI)

Test rig for periodic tests of reducers is involved as an example to discuss specific features in building automatic test systems (ATS); the test rig is designed at ZAO NPP MIKS Engineering. A certain approach to ATS design based on adaptation of universal ...

A. A. Urakov; M. A. Rylov; D. S. Shutov; P. G. Dorofeev

2011-05-01T23:59:59.000Z

92

Heat pipe array heat exchanger  

DOE Patents (OSTI)

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

Reimann, Robert C. (Lafayette, NY)

1987-08-25T23:59:59.000Z

93

Method for utilizing decay heat from radioactive nuclear wastes  

DOE Patents (OSTI)

Management of radioactive heat-producing waste material while safely utilizing the heat thereof is accomplished by encapsulating the wastes after a cooling period, transporting the capsules to a facility including a plurality of vertically disposed storage tubes, lowering the capsules as they arrive at the facility into the storage tubes, cooling the storage tubes by circulating a gas thereover, employing the so heated gas to obtain an economically beneficial result, and continually adding waste capsules to the facility as they arrive thereat over a substantial period of time.

Busey, H.M.

1974-10-14T23:59:59.000Z

94

Rock bed heat accumulators. Final report  

DOE Green Energy (OSTI)

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

Riaz, M.

1977-12-01T23:59:59.000Z

95

A study of the utility of heat collectors in reducing the response time of automatic fire sprinklers located in production modules of Building 707  

Science Conference Proceedings (OSTI)

Several of the ten production Modules in Building 707 at the Department of Energy Rocky Flats Plant recently underwent an alteration which can adversely affect the performance of the installed automatic fire sprinkler systems. The Modules have an approximate floor to ceiling height of 17.5 ft. The alterations involved removing the drop ceilings in the Modules which had been at a height of 12 ft above the floor. The sprinkler systems were originally installed with the sprinkler heads located below the drop ceiling in accordance with the nationally recognized NFPA 13, Standard for the Installation of Automatic Sprinkler Systems. The ceiling removal affects the sprinkler`s response time and also violates NFPA 13. The scope of this study included evaluation of the feasibility of utilizing heat collectors to reduce the delays in sprinkler response created by the removal of the drop ceilings. The study also includes evaluation of substituting quick response sprinklers for the standard sprinklers currently in place, in combination with a heat collector.

Shanley, J.H. Jr.; Budnick, E.K. Jr. [Hughes Associates, Inc., Wheaton, MD (United States)

1990-01-01T23:59:59.000Z

96

Heat pipe heat amplifier  

SciTech Connect

In a heat pipe combination consisting of a common condenser section with evaporator sections at either end, two working fluids of different vapor pressures are employed to effectively form two heat pipe sections within the same cavity to support an amplifier mode of operation.

Arcella, F.G.

1978-08-15T23:59:59.000Z

97

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

DOE Green Energy (OSTI)

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

Huggins, J.

1998-10-01T23:59:59.000Z

98

Heat Pumps | Department of Energy  

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

Heat Pumps Heat Pumps Heat Pumps Geothermal heat pumps are expensive to install but pay for themselves over time in reduced heating and cooling costs. Learn more about how geothermal heat pumps heat and cool buildings by concentrating the naturally existing heat contained within the earth -- a clean, reliable, and renewable source of energy. In moderate climates, heat pumps can be an energy-efficient alternative to furnaces and air conditioners. Several types of heat pumps are available, including air-source; geothermal; ductless, mini-split; and absorption heat pumps. Learn more about the different options and how to use your heat pump efficiently to save money and energy at home. Featured Heat Pump Systems A heat pump can provide an alternative to using your air conditioner. | Photo courtesy of iStockPhoto/LordRunar.

99

Radiant Heating  

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

Radiant heating systems involve supplying heat directly to the floor or to panels in the walls or ceiling of a house. The systems depend largely on radiant heat transfer: the delivery of heat...

100

Evaluation of Methodologies to Provide Comparative Heat Rates  

Science Conference Proceedings (OSTI)

Power generating companiesand even more so, their coal-fired facilitieshave struggled with the comparison of heat rate values from different periods of time. Comparing a unit's July heat rate to that recorded in January has been difficult because of several factors. First, the ambient temperatures are significantly different and manifest in operational and performance changes whose adjustments, although understood, contain uncertainty. The additional effects of variations in capacity and load following f...

2012-03-13T23:59:59.000Z

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


101

Dynamics of periodic structures in an extended laser spark  

SciTech Connect

The time scans of the intrinsic and scattered heating radiations of plasma foci, arising in the spark channel of the optical gas breakdown in a Bessel beam, were investigated. The experiments were carried out in argon at atmospheric pressure by using the heating radiation from a powerful nanosecond neodymium laser. The influence of independent preionisation and of the presence of aerosol particles was studied separately. The results indicate the appearance of bright foci against the background of the initially almost homogeneous plasma. The location of the foci in the longitudinal direction and the dynamics of the emitted radiation by them make it possible to assign the observed inhomogeneities to two quasi-periodic structures with periods differing almost by an order of magnitude. The above structures result from the operation of various mechanisms of the formation of inhomogeneities. (interaction of laser radiation with matter. laser plasma)

Bychkov, S S; Gorlov, S V; Makarov, A V; Margolin, L Ya; Pyatnitskii, Lev N; Tal'virskii, A D [Scientific Association for High Temperatures, Russian Academy of Sciences, Moscow (Russian Federation)

1999-03-31T23:59:59.000Z

102

Fundamental heat transfer experiments of heat pipes for turbine cooling  

SciTech Connect

Fundamental heat transfer experiments were carried out for three kinds of heat pipes that may be applied to turbine cooling in future aero-engines. In the turbine cooling system with a heat pipe, heat transfer rate and start-up time of the heat pipe are the most important performance criteria to evaluate and compare with conventional cooling methods. Three heat pipes are considered, called heat pipe A, B, and C, respectively. All heat pipes have a stainless steel shell and nickel sintered powder metal wick. Sodium (Na) was the working fluid for heat pipes A and B; heat pipe C used eutectic sodium-potassium (NaK). Heat pipes B and C included noncondensible gas for rapid start-up. There were fins on the cooling section of heat pipes. In the experiments, an infrared image furnace supplied heat to the heat pipe simulating turbine blade surface conditions. In the results, heat pipe B demonstrated the highest heat flux of 17 to 20 W/cm{sup 2}. The start-up time was about 6 minutes for heat pipe B and about 6 minutes for heat pipe A. Thus, adding noncondensible gas effectively reduced start-up time. Although NaK is a liquid phase at room temperature, the start-up time of heat pipe C (about 7 to 8 minutes) was not shorter than the heat pipe B. The effect of a gravitational force on heat pipe performance was also estimated by inclining the heat pipe at an angle of 90 deg. There was no significant gravitational dependence on heat transport for heat pipes including noncondensible gas.

Yamawaki, S. [Ishikawajima-Harima Heavy Industries Co., Ltd., Tokyo (Japan); Yoshida, T.; Taki, M.; Mimura, F. [National Aerospace Lab., Tokyo (Japan)

1998-07-01T23:59:59.000Z

103

Heat pipe technology issues  

SciTech Connect

Critical high temperature, high power applications in space nuclear power designs are near the current state of the art of heat pipe technology in terms of power density, operating temperature, and lifetime. Recent heat pipe development work at Los Alamos National Laboratory has involved performance testing of typical space reactor heat pipe designs to power levels in excess of 19 kW/cm/sup 2/ axially and 300 W/cm/sup 2/ radially at temperatures in the 1400 to 1500 K range. Operation at conditions in the 10 kW/cm/sup 2/ range has been sustained for periods of up to 1000 hours without evidence of performance degradation. The effective length for heat transport in these heat pipes was from 1.0 to 1.5 M. Materials used were molybdenum alloys with lithium employed as the heat pipe operating fluid. Shorter, somewhat lower power, molybdenum heat pipes have been life tested at Los Alamos for periods of greater than 25,000 hours at 1700 K with lithium and 20,000 hours at 1500/sup 0/K with sodium. These life test demonstrations and the attendant performance limit investigations provide an experimental basis for heat pipe application in space reactor design and represent the current state-of-the-art of high temperature heat pipe technology.

Merrigan, M.A.

1984-04-01T23:59:59.000Z

104

EFFECT OF HEATING RATE ON THE THERMODYNAMIC PROPERTIES OF PULVERIZED COAL  

SciTech Connect

This final technical report describes work performed under DOE Grant No. DE-FG22-96PC96224 during the period September 24, 1996 to September 23, 1999 which covers the entire performance period of the project. During this period, modification, alignment, and calibration of the measurement system, measurement of devolatilization time-scales for single coal particles subjected to a range of heating rates and temperature data at these time-scales, and analysis of the temperature data to understand the effect of heating rates on coal thermal properties were carried out. A new thermodynamic model was developed to predict the heat transfer behavior for single coal particles using one approach based on the analogy for thermal property of polymers. Results of this model suggest that bituminous coal particles behave like polymers during rapid heating on the order of 10{sup 4}-10{sup 5} K/s. At these heating rates during the early stages of heating, the vibrational part of the heat capacity of the coal molecules appears to be still frozen but during the transition from heat-up to devolatilization, the heat capacity appears to attain a sudden jump in its value as in the case of polymers. There are a few data available in the coal literature for low heating rate experiments (10{sup 2}-10{sup 3} K/s) conducted by UTRC, our industrial partner, in this project. These data were obtained for a longer heating duration on the order of several seconds as opposed to the 10 milliseconds heating time of the single particle experiments discussed above. The polymer analogy model was modified to include longer heating time on the order of several seconds to test these data. However, the model failed to predict these low heating rate data. It should be noted that UTRC's work showed reasonably good agreement with Merrick model heat capacity predictions at these low heating rates, but at higher heating rates UTRC observed that coal thermal response was heat flux dependent. It is concluded that at combustion level heating rates (10{sup 4}-10{sup 5} K/s) coal structural changes are delayed and attendant increases in heat capacity and thermal conductivity are pushed to higher temperatures or require significant hold times to become manifest.

Ramanathan Sampath

2000-01-01T23:59:59.000Z

105

Timed fast charger  

Science Conference Proceedings (OSTI)

In a charger for rechargeable electrochemical cells, a transformer charging circuit supplies a charging current to the battery at a fast charge rate for a predetermined time followed by a continuous slow charge rate. A normally closed automatic reset thermostat in series with the rectifier diodes in the charging circuit, and thermally coupled to them, opens after a period of time, dependent upon the heat generated by the rectifier diodes and upon the thermal mass of the thermostat and diodes, and terminates the fast charge current. A resistor, shunted across the thermostat and thermally coupled to it, establishes a slow charge rate current path when the thermostat opens. Heat generated in the resistor causes the thermostat to remain open as long as the battery is connected and ac power is supplied to the transformer primary winding.

Mullersman, F.H.

1981-10-27T23:59:59.000Z

106

EFFECT OF HEATING RATE ON THE THERMODYNAMIC PROPERTIES OF PULVERIZED COAL  

Science Conference Proceedings (OSTI)

This semi-annual technical progress report describes work performed under DOE Grant No. DE-FG22-96PC96224 during the period March 24, 1999 to September 23, 1999 which covers the last (sixth) six months of the project. During this reporting period, extraction of devolatilization time-scales and temperature data at these time-scales analyzing the high-speed films taken during the experiments was complete. Also a new thermodynamic model was developed to predict the heat transfer behavior for coal particles subjected to a range of heating rates using one approach based on the analogy of polymers. Sensitivity analyses of this model suggest that bituminous coal particles behave like polymers during rapid heating on the order of 10{sup 4}-10{sup 7} K/s. At these heating rates during the early stages within the first few milliseconds of heating time, the vibrational part of the heat capacity of the coal molecules appears to be still frozen but during the transition from heat-up to devolatization, the heat capacity appears to attain a sudden jump in its value as in the case of polymers. There are few data available in the coal literature for 10{sup 2}-10{sup 3} K/s obtained by UTRC in their previous studies. These data were obtained for a longer heating duration on the order of several seconds as opposed to the 10 milliseconds heating time in the single particle experiments discussed above. The polymer analogy model is being modified to include longer heating time on the order of several seconds to test these data. It is expected that the model might still do a good job in the case of these larger heating time but very low heating rate experiments. Completion of the numerical analysis of the experimental data and preparation of the final report are in progress.

Ramanathan Sampath

1999-11-02T23:59:59.000Z

107

Water heater heat reclaimer  

SciTech Connect

This invention relates to the conservation of energy in a domestic gas water heater by utilizing the hot exhaust gases in a gas water heater for the preheating of the incoming unheated water into the water heater. The exhaust gases from a domestic gas water heater carry wasted heat and the present invention provides a mean to reclaim part of the wasted heat for the preheating of the incoming unheated water during hot water usage periods. During non hot water usage periods the heat in the exhaust gases is not reclaimed to prevent overheating of the water and also to prevent the formation of water deposit in the preheating assembly or heat reclaimer. During the non hot water usage periods the heat produced in the water heater is normally needed only to maintain the desired water temperature of the stored water in the water tank of the water heater. Due to the rapid heating or recovery rate, the present invention enables the use of a smaller water heater. The use of a smaller water heater reduces the normal heat loss from the stored hot water thereby further reduces energy consumption.

Wie, C.T.

1983-08-09T23:59:59.000Z

108

Performance of a solar energy-assisted heat pump heating system: analysis and correlation of field-collected data  

SciTech Connect

An analysis of building energy usage and thermal load for the Solar Building during the winter heating seasons of 1974-75 and 1975-76 is reported. The one-story office building is located in Albuquerque, New Mexico. Its mechanical heating and cooling equipment is categorized as a solar-assisted heat pump system consisting of solar collectors, water thermal storage, a water-to-water heat pump and five smaller water-to-air heat pump packaged units. Building energy usage was examined with emphasis on the time of day energy was consumed and the source from which the energy was obtained; i.e., from the electricity for lighting, office equipment and mechanical equipment, and from the heat output of the thermal storage and heat pumps. The rate of electrical energy consumption was found to be very dependent on building use. High rates of electrical energy usage during occupied periods required cooling during parts of even the coldest days. Mechanical equipment heating was found to vary as a function of building usage as well as a function of the indoor-outdoor temperature differential. Energies supplied to and withdrawn from the building were examined and are presented for hourly, daily, and seasonal periods. A comparison of the two heating seasons was made. Energy losses and gains from the building to the surroundings were examined for both steady-state and transient load profiles. Envelope conductive heat losses and losses due to infiltration and ventilation were calculated using actual weather data through the use of the Building Environmental Analysis Program (BEAP). The effect of building thermal storage on heating and cooling loads was examined and a set of building balance-point temperatures was established. Comparisons between the building energy consumption and a calculated load were made for hourly, daily, and seasonal periods.

Williams, R.C.

1979-08-01T23:59:59.000Z

109

Heating Alloys  

Science Conference Proceedings (OSTI)

...are used in many varied applications--from small household appliances to large industrial process heating systems and furnaces. In appliances or industrial process heating, the heating elements are usually either open

110

Heating Systems  

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

A variety of heating technologies are available today. In addition to heat pumps, which are discussed separately, many homes and buildings use the following approaches:

111

Continuous Time Series of Catchment-Averaged Sensible Heat Flux from a Large Aperture Scintillometer: Efficient Estimation of Stability Conditions and Importance of Fluxes under Stable Conditions  

Science Conference Proceedings (OSTI)

A large aperture scintillometer (LAS) observes the intensity of the atmospheric turbulence across large distances, which is related to the path-averaged sensible heat flux H. In this paper, two problems in the derivation of continuous series of H ...

Bruno Samain; Willem Defloor; Valentijn R. N. Pauwels

2012-04-01T23:59:59.000Z

112

Residential Heating Oil Prices  

Gasoline and Diesel Fuel Update (EIA)

This chart highlights residential heating oil prices for the current and This chart highlights residential heating oil prices for the current and past heating season. As you can see, prices have started the heating season, about 40 to 50 cents per gallon higher than last year at this time. The data presented are from EIA's State Heating Oil and Propane Program. We normally collect and publish this data twice a month, but given the low stocks and high prices, we started tracking the prices weekly. These data will also be used to determine the price trigger mechanism for the Northeast Heating Oil Reserve. The data are published at a State and regional level on our web site. The slide is to give you some perspective of what is happening in these markets, since you probably will get a number of calls from local residents about their heating fuels bills

113

HEAT CAPACITY MEASUREMENTS IN PULSED MAGNETIC FIELDS  

E-Print Network (OSTI)

(World Scientific, to be published) The new NHMFL 60T quasi-continuous magnet produces a flat-top field for a period of 100 ms at 60 Tesla, and for longer time at lower fields, e.g. 0.5 s at 35 Tesla. We have developed for the first time the capability to measure heat capacity at very high magnetic fields in the NHMFL 60T quasi-continuous magnet at LANL, using a probe built out of various plastic materials. The field plateau allows us to utilize a heat-pulse method to obtain heat capacity data. Proof-of-principle heat capacity experiments were performed on a variety of correlated electron systems. Both magnet performance characteristics and physical properties of various materials studied hold out a promise of wide application of this new tool. 1 I. TECHNIQUE The 60 Tesla Long-Pulse (60TLP) magnet was recently commissioned at the Los Alamos National Laboratory. This magnet produces a flat-top field for a period of 100 ms at 60

M. Jaime; R. Movshovich; J. L. Sarrao; J. Kim; G. Stewart; W. P. Beyermann

1999-01-01T23:59:59.000Z

114

FEMP--Geothermal Heat Pumps  

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

heat pump-like an air conditioner or refrigera- heat pump-like an air conditioner or refrigera- tor-moves heat from one place to another. In the summer, a geothermal heat pump (GHP) operating in a cooling mode lowers indoor temperatures by transferring heat from inside a building to the ground outside or below it. Unlike an air condition- er, though, a heat pump's process can be reversed. In the winter, a GHP extracts heat from the ground and transfers it inside. Also, the GHP can use waste heat from summer air-conditioning to provide virtually free hot-water heating. The energy value of the heat moved is typically more than three times the electricity used in the transfer process. GHPs are efficient and require no backup heat because the earth stays at a relatively moderate temperature throughout the year.

115

Heat pipe development status  

SciTech Connect

Test heat pipes have been operated in the 1400 K to 1700 K range for periods in excess of 20,000 hours with the objective of understanding and controlling corrosion and failure mechanisms. The results of a post test analysis of one of these heat pipes that was operated for 25,216 hours at 1700 K are reviewed and the implications for heat pipe lifetime discussed. An in-process report of an investigation of transient heat pipe behavior is presented. This investigation is being conducted as a result of restart problems encountered during life test of a 2 m. radiation cooled heat pipe. The results of a series of shut-down tests from power and temperature are given and probable causes of the restart problem discussed.

Merrigan, M.A.

1984-01-01T23:59:59.000Z

116

Planning analyses for geothermal district heating  

DOE Green Energy (OSTI)

Methodology and data bases are described which can provide a comprehensive planning assessment of the potential for geothermal district heating in any US market. This economic systems model encompasses life-cycle costing over a period of rising competitive fuel prices, it addresses the expansion and financing of a district system over time, and it includes an overall optimization of system design. The elemental area for all analyses is the census tract, for which published data allow estimation of residential and commercial heating demands, building retrofit requirements, and competitive fuel consumption and cost. A system type design, an appropriate hot water district piping system, and costing of heat supply is performed for groups of contiguous tracts in any urban market. Groups are aggregated, in decreasing benefit to cost order, to achieve optimal systems. A specific application for Salt Lake City, Utah, is also described.

Tessmer, R.G. Jr.; Karkheck, J.

1979-12-01T23:59:59.000Z

117

Energy resource alternatives competition. Progress report for the period February 1, 1975--December 31, 1975. [Space heating and cooling, hot water, and electricity for homes, farms, and light industry  

DOE Green Energy (OSTI)

This progress report describes the objectives and results of the intercollegiate Energy Resource Alternatives competition. The one-year program concluded in August 1975, with a final testing program of forty student-built alternative energy projects at the Sandia Laboratories in Albuquerque, New Mexico. The goal of the competition was to design and build prototype hardware which could provide space heating and cooling, hot water, and electricity at a level appropriate to the needs of homes, farms, and light industry. The hardware projects were powered by such nonconventional energy sources as solar energy, wind, biologically produced gas, coal, and ocean waves. The competition rules emphasized design innovation, economic feasibility, practicality, and marketability. (auth)

Matzke, D.J.; Osowski, D.M.; Radtke, M.L.

1976-01-01T23:59:59.000Z

118

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  

Science Conference Proceedings (OSTI)

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.

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

1998-09-30T23:59:59.000Z

119

Heat Pump System Basics | Department of Energy  

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

Heat Pump System Basics Heat Pump System Basics Heat Pump System Basics August 19, 2013 - 11:02am Addthis Like a refrigerator, heat pumps use electricity to move heat from a cool space into a warm space, making the cool space cooler and the warm space warmer. Because they move heat rather than generate heat, heat pumps can provide up to four times the amount of energy they consume. Air-Source Heat Pump Transfers heat between the inside of a building and the outside air. Ductless Mini-Split Heat Pump Ductless versions of air-source heat pumps. Absorption Heat Pump Uses heat as its energy source. Geothermal Heat Pumps Use the constant temperature of the earth as the exchange medium instead of the outside air temperature. Addthis Related Articles A heat pump can provide an alternative to using your air conditioner. | Photo courtesy of iStockPhoto/LordRunar.

120

Heat pipe technology for coal-fired power systems  

SciTech Connect

This report summarizes the results of heat pipe R and D activities at Argonne National Laboratory (ANL) during the 1977 to 1984 time period. The heat pipe development efforts were associated with a variety of DOE supported projects involving coal-fired prime movers for stationary power generation. The role of heat pipes for these power systems is in their potential application as thermal transport systems for integrating fluidized bed combustors (FBC) with prime movers ranging from Stirling engines in total energy systems (approx.10 MWe) to closed-cycle gas turbines in central power plants (approx.1000 MWe). The results of initial investigations at ANL demonstrated that high-temperature sodium heat pipes provided the best heat exchanger technology for integrating Stirling engines with coal-fired FBC systems. A major accomplishment included the development and validation of a computer code (ANL/HTP) which calculates heat pipe operating limits and other significant characteristics necessary for power plant design. A number of developmental and prototype heat pipes were designed and fabricated through a subcontract effort with Thermacore, Inc., and delivered to ANL for performance testing. Preliminary test results from ANL's Heat Pipe Test Facility, using induction heating and a gas-water calorimeter to establish energy balances, are given in the report. Test data obtained to date are consistent with ANL/HTP code predictions. 47 refs., 53 figs., 22 tabs.

Uherka, K.L.; Holtz, R.E.; McLennan, G.A.; Koehl, E.R.

1985-04-01T23:59:59.000Z

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


121

Definition: Heat | Open Energy Information  

Open Energy Info (EERE)

Heat Heat Jump to: navigation, search Dictionary.png Heat Heat is the form of energy that is transferred between systems or objects with different temperatures (flowing from the high-temperature system to the low-temperature system). Also referred to as heat energy or thermal energy. Heat is typically measured in Btu, calories or joules. Heat flow, or the rate at which heat is transferred between systems, has the same units as power: energy per unit time (J/s).[1][2][3][4] View on Wikipedia Wikipedia Definition In physics and chemistry, heat is energy in transfer between a system and its surroundings other than by work or transfer of matter. The transfer can occur in two simple ways, conduction, and radiation, and in a more complicated way called convective circulation. Heat is not a property

122

Risk-averse periodic preventive maintenance optimization.  

E-Print Network (OSTI)

??We consider a class of periodic preventive maintenance (PM) optimization problems, for a single piece of equipment that deteriorates with time or use, and can… (more)

Singh, Inderjeet,1978-

2011-01-01T23:59:59.000Z

123

Forest understory soil temperatures and heat flux calculated using a Fourier model and scaled using a digital camera  

E-Print Network (OSTI)

uneven but periodic solar heating of the soil surface due tothe uneven but periodic solar heating of the soil due to a

Graham, Eric; Lam, Yeung; Yuen, Eric

2010-01-01T23:59:59.000Z

124

Heat Conduction  

Science Conference Proceedings (OSTI)

Table 2   Differential equations for heat conduction in solids...conduction in solids General form with variable thermal properties General form with constant thermal properties General form, constant properties, without heat

125

Heat exchanger  

DOE Patents (OSTI)

A heat exchanger is provided having first and second fluid chambers for passing primary and secondary fluids. The chambers are spaced apart and have heat pipes extending from inside one chamber to inside the other chamber. A third chamber is provided for passing a purge fluid, and the heat pipe portion between the first and second chambers lies within the third chamber.

Daman, Ernest L. (Westfield, NJ); McCallister, Robert A. (Mountain Lakes, NJ)

1979-01-01T23:59:59.000Z

126

Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas-  

Open Energy Info (EERE)

Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Features And Examples Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Features And Examples Details Activities (5) Areas (5) Regions (0) Abstract: Surface heat flow measurements over active geothermal systems indicate strongly positive thermal anomalies. Whereas in "normal" geothermal settings, the surface heat flow is usually below 100-120 mW m- 2, in active geothermal areas 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 different lateral, depth and time scales. Borehole temperature profiles in active geothermal

127

Optimization of Heat Exchanger Cleaning  

E-Print Network (OSTI)

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, economic incentives for heat exchanger cleaning are evaluated using linear, exponential, and exponential finite decrease models of the heat recovery decay. A mathematical comparison of mechanical and chemical cleaning of heat exchangers has identified the most significant parameters which affect the choice between the two methods.

Siegell, J. H.

1986-06-01T23:59:59.000Z

128

Heat Pump Water Heaters | Department of Energy  

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

Water Heaters Water Heaters Heat Pump Water Heaters May 4, 2012 - 5:21pm Addthis A diagram of a heat pump water heater. A diagram of a heat pump water heater. What does this mean for me? Heat pump water heaters can be two to three times more energy efficient than conventional electric storage water heaters. Heat pump water heaters work in locations that remain in the 40Âş-90ÂşF range year-round. Most homeowners who have heat pumps use them to heat and cool their homes. But a heat pump also can be used to heat water -- either as stand-alone water heating system, or as combination water heating and space conditioning system. How They Work Heat pump water heaters use electricity to move heat from one place to another instead of generating heat directly. Therefore, they can be two to

129

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...

130

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* ... 222 194 17...

131

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 ... 2,100...

132

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* ... 1,928 1,316...

133

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...

134

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...

135

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...

136

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...

137

Hot dry rock heat mining: An alternative energy progress report  

DOE Green Energy (OSTI)

Mining Heat from the hot dry rock (HDR) resource that lies beneath the earth's crust may provide an almost inexhaustible supply of energy for mankind with minimal environmental effects. In the heat mining process, water is pumped down an injection well into a mass of hydraulically fractured hot rock. As the water flows under high pressure through the opened rock joints, it becomes heated by the rock. It is returned to the surface through a production well (or wells) located some distance from the injector where its thermal energy is recovered by a heat exchanger. The same water is then recirculated through the system to extract more thermal energy. In this closed-loop process, nothing but heat is released to the environment during normal operation. The technical feasibility of HDR heat mining already has been proven by field testing. A long-term flow test is scheduled to begin in 1991 at the world's largest HDR heat mine in New Mexico, USA, to demonstrate that energy can be produced from HDR on a continuous basis over an extended time period. Significant HDR programs are also underway in several other countries. The paper describes the HDR resource, the heat mining concept, environmental characteristics, economics, developments at Los Alamos to date, and HDR development outside the US. 15 refs., 5 figs., 2 tabs.

Duchane, D.V.

1991-01-01T23:59:59.000Z

138

Modelling transient heat conduction in solids at multiple length and time scales: A coupled non-equilibrium molecular dynamics/continuum approach  

SciTech Connect

A method for controlling the thermal boundary conditions of non-equilibrium molecular dynamics simulations is presented. The method is simple to implement into a conventional molecular dynamics code and independent of the atomistic model employed. It works by regulating the temperature in a thermostatted boundary region by feedback control to achieve the desired temperature at the edge of an inner region where the true atomistic dynamics are retained. This is necessary to avoid intrinsic boundary effects in non-equilibrium molecular dynamics simulations. Three thermostats are investigated: the global deterministic Nose-Hoover thermostat and two local stochastic thermostats, Langevin and stadium damping. The latter thermostat is introduced to avoid the adverse reflection of phonons that occurs at an abrupt interface. The method is then extended to allow atomistic/continuum models to be thermally coupled concurrently for the analysis of large steady state and transient heat conduction problems. The effectiveness of the algorithm is demonstrated for the example of heat flow down a three-dimensional atomistic rod of uniform cross-section subjected to a variety of boundary conditions.

Jolley, Kenny [Department of Engineering, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Gill, Simon P.A. [Department of Engineering, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)], E-mail: spg3@le.ac.uk

2009-10-20T23:59:59.000Z

139

Heating Oil and Propane Update  

Gasoline and Diesel Fuel Update (EIA)

State Energy Offices State Energy Offices Q1: What price should be reported to EIA when submitting weekly data? EIA requests that you collect / report the residential credit price (keep-full prices being preferred) and that all prices exclude taxes for the Monday of each survey week, even if that Monday falls on a holiday. Prices should not include discounts for payment of cash or for payment made within a short period of time. However, if a company deals exclusively in cash, then this price should be reported and noted in the file sent to EIA. Q2: When is this data due to EIA each week? The EIA-877 "Winter Heating Fuels Telephone Survey" will begin the first Monday in October. Data should be submitted to EIA as soon as they are available but no later than noon on Tuesday of each week. Data collection

140

Heat Rate Program Guidelines  

Science Conference Proceedings (OSTI)

Power plant facilities with performance or heat rate improvement programs perform better than those that do not have those programs. A heat rate improvement program typically provides sufficient information for decision making with respect to timely maintenance actions and/or operational adjustments. Monitoring the performance of any power plant component includes the trending of parameters that also describe the performance of other plant components, providing insight and information on improving ...

2012-12-31T23:59:59.000Z

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


141

Cost-effective solar collectors using heat pipes. Interim progress report No. 2, April 1978-September 1978  

DOE Green Energy (OSTI)

Heat pipe fluid-vessel combinations continued to be life tested at design and stagnation conditions for time periods exceeding 14,000 hours. Additional testing was carried out at the lower end of the environment temperature range by freeze-thaw testing of several water heat pipes. Additional fluids search work resulted in developing a procedure to purify trimethylborate. Eight trimethylborate heat pipes were fabricated and installed in a modified GE TC-100 solar panel. Solar performance tests were performed on the heat pipe collector and a standard TC-100 collector. Heat pipe collector performance exceeded 90% of the TC-100. A source of water compatible steel, NP454, was identified as was an experimental tubing manufacturer. The current availability of NP454 and the successful demonstration of antifreeze mechanisms lays the ground work for testing a heat pipe collector using water heat pipes.

Ernst, D.M.

1978-01-01T23:59:59.000Z

142

Solar Water Heating System Maintenance and Repair | Department of Energy  

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

Water Heating System Maintenance and Repair Water Heating System Maintenance and Repair Solar Water Heating System Maintenance and Repair May 30, 2012 - 2:35pm Addthis Rooftop solar water heaters need regular maintenance to operate at peak efficiency. | Photo from iStockphoto.com Rooftop solar water heaters need regular maintenance to operate at peak efficiency. | Photo from iStockphoto.com Solar energy systems require periodic inspections and routine maintenance to keep them operating efficiently. Also, from time to time, components may need repair or replacement. You should also take steps to prevent scaling, corrosion, and freezing. You might be able to handle some of the inspections and maintenance tasks on your own, but others may require a qualified technician. Ask for a cost estimate in writing before having any work done. For some systems, it may

143

Use of Real-Time Multisensor Data to Assess the Relationship of Normalized Corn Yield with Monthly Rainfall and Heat Stress across the Central United States  

Science Conference Proceedings (OSTI)

This study evaluated the suitability of rain estimates based on the National Weather Service (NWS) Weather Surveillance Radar-1988 Doppler (WSR-88D) network to estimate yield response to rainfall on a county scale and to provide real-time ...

Nancy E. Westcott; Steven E. Hollinger; Kenneth E. Kunkel

2005-11-01T23:59:59.000Z

144

Solar heating system for recreation building at Scattergood School  

DOE Green Energy (OSTI)

This project was initiated in May 1976 and was completed in June 1977. A six-month acceptance-testing period followed during which time a number of minor modifications and corrections were made to improve system performance and versatility. This Final Report describes in considerable detail the solar heating facility and the project involved in its construction. As such, it has both detailed drawings of the completed system and a section that discusses the bottlenecks that were encountered along the way.

Heins, C.F.

1978-01-03T23:59:59.000Z

145

Self-consistent microwave plasma heating rates  

SciTech Connect

Under conditions within a hot overdense plasma corona where the field frequency is much less than the electron plasma frequency and the field period is much less than the hydrodynamic expansion time it is shown that electron field reversal heating can exceed the combined classical heating rates due to inverse bremsstrahlung (skin effect) and field pressure (PdV) by a factor approximately v/ sub e//2v/sub i/ (half the ratio of electron and ion thermal velocities). In particular this rate can exceed the inertial expansion cooling rate at a collisionless corona density of approximately 1 percent solid core density and could be realized experimentally at core temperatures approximately 3--5 keV and microwave field intensities approximately 1 MG. (auth)

Ensley, D.L.; White, R.H.

1975-10-01T23:59:59.000Z

146

Heat Stroke  

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

stress, from exertion or hot environments, places stress, from exertion or hot environments, places workers at risk for illnesses such as heat stroke, heat exhaustion, or heat cramps. Heat Stroke A condition that occurs when the body becomes unable to control its temperature, and can cause death or permanent disability. Symptoms â–  High body temperature â–  Confusion â–  Loss of coordination â–  Hot, dry skin or profuse sweating â–  Throbbing headache â–  Seizures, coma First Aid â–  Request immediate medical assistance. â–  Move the worker to a cool, shaded area. â–  Remove excess clothing and apply cool water to their body. Heat Exhaustion The body's response to an excessive loss of water and salt, usually through sweating. Symptoms â–  Rapid heart beat â–  Heavy sweating â–  Extreme weakness or fatigue â– 

147

Heat reclaimer  

Science Conference Proceedings (OSTI)

A device for reclaiming heat from stove pipes and the like. A semi-circular shaped hollow enclosed housing with a highly thermal-conductive concave surface is mounted contactingly to surround approximately one-half of the circumference of the stove pipe. The concave surface is formed to contact the pipe at a maximum number of points along that surface. The hollow interior of the housing contains thin multi-surfaced projections which are integral with the concave surface and conductively transfer heat from the stove pipe and concave surface to heat the air in the housing. A fan blower is attached via an air conduit to an entrance opening in the housing. When turned on, the blower pushes the heated interior air out a plurality of air exit openings in the ends of the housing and brings in lower temperature outside air for heating.

Parham, F.

1985-04-09T23:59:59.000Z

148

Heat transfer. [heat transfer roller employing a heat pipe  

SciTech Connect

A heat transfer roller embodying a heat pipe is disclosed. The heat pipe is mounted on a shaft, and the shaft is adapted for rotation on its axis.

Sarcia, D.S.

1978-05-23T23:59:59.000Z

149

Budget Period 1  

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

Budget Period 1 Budget Period 1 Budget Period 2 Budget Period 3 0.0% 0.0% 0.0% PMC123.1 - Budget Justification for SF 424A Budget 0 Additional Explanations/Comments (as necessary) *IMPORTANT: In the space provided below (or as an attachment) provide a complete explanation and the full calculations used to derive the total indirect costs. If the total indirect costs are a cumulative amount of more than one calculation or rate application, the explanation and calculations should identify all rates used, along with the base they were applied to (and how the base was derived), and a total for each (along with grand total). The rates and how they are applied should not be averaged to get one indirect cost percentage. NOTE: The indirect rate should be applied to both the Federal Share and Recipient Cost Share.

150

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

SciTech Connect

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.

2010-09-01T23:59:59.000Z

151

Geothermal-district-heating assessment model for decision making  

DOE Green Energy (OSTI)

A methodology developed to assess the economic feasibility of district heating for any community in the United States is described. The overall philosophy which has guided its development is the conviction that district heating must be examined on a site-by-site basis. To support this approach, a set of extensive, in-house supporting data bases has been created and useful external data bases with national coverage have been identified. These data bases provide information at a sufficient level of detail to permit a first-cut examination of the district heating potential of a community without requiring outside data collection (allowing a substantial cost and time savings). The results of this blind look at a community permit a rapid, yet adequate estimate of district heating potential, costs, and energy savings. The data utilized in the initial examination can be supplemented or replaced by more detailed information obtained from on-site data collection, if the first results are promising. The fact that the data and methodology are computerized allows many locations within the community, alternate heat sources, ownership options, pipe technologies, etc. to be examined in a short period of time. The structure of the District Heating Model (DHM) (the methodology in computerized form) is described followed by a discussion of the application of the model to Provo, UT.

Reisman, A.

1981-11-01T23:59:59.000Z

152

Heat collector  

DOE Patents (OSTI)

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

Merrigan, M.A.

1981-06-29T23:59:59.000Z

153

Heat collector  

DOE Patents (OSTI)

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

Merrigan, Michael A. (Santa Cruz, NM)

1984-01-01T23:59:59.000Z

154

Nitrogen heat pipe for cryocooler thermal shunt  

SciTech Connect

A nitrogen heat pipe was designed, built and tested for the purpose of providing a thermal shunt between the two stages of a Gifford-McMahan (GM) cryocooler during cooldown. The nitrogen heat pipe has an operating temperature range between 63 and 123 K. While the heat pipe is in the temperature range during the system cooldown, it acts as a thermal shunt between the first and second stage of the cryocooler. The heat pipe increases the heat transfer to the first stage of the cryocooler, thereby reducing the cooldown time of the system. When the heat pipe temperature drops below the triple point, the nitrogen working fluid freezes, effectively stopping the heat pipe operation. A small heat leak between cryocooler stages remains because of axial conduction along the heat pipe wall. As long as the heat pipe remains below 63 K, the heat pipe remains inactive. Heat pipe performance limits were measured and the optimum fluid charge was determined.

Prenger, F.C.; Hill, D.D.; Daney, D.E.; Daugherty, M.A. [Los Alamos National Lab., NM (United States); Green, G.F.; Roth, E.W. [Naval Surface Warfare Center, Annapolis, MD (United States)

1995-09-01T23:59:59.000Z

155

Qualification of aluminum for OTEC heat exchangers  

DOE Green Energy (OSTI)

The basis for qualification of aluminum as a material for use as tubing in Ocean Thermal Energy Conversion heat exchangers is reviewed. Reference is made to compendia of data from tests of aluminum alloys in natural sea water and to applicable service records. Data from these sources were found to be inadequate to either qualify or disqualify aluminum. They serve only to identify the 5052 alloy and Alclad 3003 or 3004 as being worthy of additional testing under conditions more directly related to what will be encountered in OTEC heat exchangers. The principal deficiency of data from long-time tests in natural sea water is that in almost all of these tests the specimens were exposed under static conditions that caused the surfaces to be covered by marine fouling organisms that would not be present in heat exchanger tubes. The tests did not take into account possible effects of periodic mechanical or chemical treatments to remove fouling or chemical treatments (chlorination) to prevent fouling. A current testing program sponsored by the Department of Energy through Argonne National Laboratory is designed to provide the needed data. Limited tests in high velocity sea water have indicated that aluminum tubes would tolerate the velocities under 10 ft (3 m) per second likely to be used in OTEC heat exchangers.

LaQue, F.L.

1979-05-01T23:59:59.000Z

156

Liquid metal heat pipe behavior under transient cooling and heating  

SciTech Connect

This paper describes the results of an experimental investigation of the transient behavior of a liquid metal heat pipe. A 0.457 m long, screen-wick, sodium heat pipe with 0.0127 m outer diameter was tested in sodium loop facility. The heat pipe reversed under a pulse heat load applied at the condenser. The time at which the heat pipe reversed was dependent of the heat pipe properties, the sodium loop flow rate and heating conditions at the condenser. The start-up and the operational shut-down by forced cooling of the condenser were also studied. During the start-up process, at least part of the heat pipe was active. The active region extended gradually down to the end of the condenser until all working fluid in the heat pipe was molten. With forced cooling at the condenser, the heat pipe approached its heat transport limit before section of the condenser became frozen. The measured heat transport limit was in agreement with the theoretical value. 5 refs.

Nguyen, H.X.; Hahn, T.O.; Hahn, O.J.; Chow, L.C.; Tagavi, K.A.; Morgan, M.J. (Kentucky, University, Lexington (United States) USAF, Wright Laboratory, Wright-Patterson AFB, OH (United States))

1992-01-01T23:59:59.000Z

157

Energy Basics: Heat Pump Systems  

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

Systems Air-Source Heat Pumps Ductless Mini-Split Heat Pumps Absorption Heat Pumps Geothermal Heat Pumps Supporting Equipment for Heating & Cooling Systems Water Heating Heat...

158

Heat reclaimer  

SciTech Connect

An apparatus for reclaiming heat from the discharge gas from a combustion fuel heating unit, which has: inlet and outlet sections; an expansion section whose circumference gradually increases in the direction of flow, thereby providing an increased area for heat transfer; flow splitter plates which lie within and act in conjunction with the expansion section wall to form flow compartments, which flow splitter plates and expansion section wall have a slope, with respect to the centroidal axis of the flow compartment not exceeding 0.1228, which geometry prevents a separation of the flow from the enclosing walls, thereby increasing heat transfer and maintaining the drafting function; and a reduction section which converges the flow to the outlet section.

Horkey, E.J.

1982-06-29T23:59:59.000Z

159

Process Heating  

Science Conference Proceedings (OSTI)

This technical update uses real world examples to discuss applications of electrotechnology in industrial process heating and to highlight some of the emerging technologies in this field. These emerging technologies, when implemented in a plant, will provide significant energy savings as well as increase productivity. The report presents three case studies of successful implementation of two different electric process-heating technologies in three different industries. The case studies show that in some ...

2011-12-07T23:59:59.000Z

160

HEAT EXCHANGER  

DOE Patents (OSTI)

A heat exchanger is designed for use in the transfer of heat between a radioactive fiuid and a non-radioactive fiuid. The exchanger employs a removable section containing the non-hazardous fluid extending into the section designed to contain the radioactive fluid. The removable section is provided with a construction to cancel out thermal stresses. The stationary section is pressurized to prevent leakage of the radioactive fiuid and to maintain a safe, desirable level for this fiuid. (AEC)

Fox, T.H. III; Richey, T. Jr.; Winders, G.R.

1962-10-23T23:59:59.000Z

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


161

Corrosive resistant heat exchanger  

DOE Patents (OSTI)

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

Richlen, Scott L. (Annandale, VA)

1989-01-01T23:59:59.000Z

162

Field test and assessment of thermal energy storage for residential heating  

SciTech Connect

Thermal energy storage (TES) heating units can be connected to the utility grid to accept electricity only during utility off-peak periods and yet provide round-the-clock comfort heating. Their use by an increasingly larger part of the electric-heat market could provide economic and oil-saving benefits. A field test was carried out over two full heating seasons in Vermont and Maine at 45 TES sites and 30 control sites heated by electric baseboard heaters. The TES users were billed under applicable time-of-day (TOD) rates. All sites were instrumented, and measurements of inside and outside temperatures and electrical energy consumption for heating were made and recorded every 15 min. Analysis of the data has led to the following findings and conclusions: Overall technical performance of the TES units was good under extreme weather conditions. Annualized energy use was the same for the TES and the control households. Proper sizing of the storage systems is much more important for storage heaters than for nonstorage heaters. TES users were satisfied with performance. Electric-heat bills were much lower for TES users. Occupancy effects were large and caused wide variations in energy consumption on days that had the same number of heating degree-days. The individual building heat loss determined experimentally from an analysis of the actual energy consumption per heating degreeday was 30% to 50% smaller than that determined by a walkthrough energy audit.

Hersh, H.

1983-12-01T23:59:59.000Z

163

Periodic load balancing  

Science Conference Proceedings (OSTI)

Multiprocessor load balancing aims to improve performance by moving jobs from highly loaded processors to more lightly loaded processors. Some schemes allow only migration of new jobs upon arrival, while other schemes allow migration of ... Keywords: heavy traffic diffusion approximations, load balancing, periodic load balancing, reflected Brownian motion, resource sharing, transient behavior

Gísli Hjálmtýsson; Ward Whitt

1998-06-01T23:59:59.000Z

164

The Neural Heat Exchanger  

E-Print Network (OSTI)

The "Neural Heat Exchanger" is an alternative, supervised learning method for multi-layer neural nets. It is inspired by the physical heat exchanger. Unlike backprop, it is entirely local. This makes its parallel implementation trivial. It was first presented during occasional talks since 1990, and is closely related to Hinton et. al.'s recent Helmholtz Machine (1995). For the first time, this paper presents the basic ideas in written form. To fully understand the Neural Heat Exchanger's advantages and limitations, however, much theoretical and empirical work remains to be done. 1 Introduction Most conventional supervised algorithms for multi-layer neural nets are not local in space and time. Backprop, for instance, requires a global control mechanism that first propagates activation signals through all successive layers, then waits until the error signals come back, then changes the weights. Many suspect, however, that the brain does use an entirely local algorithm. One advantage of...

Jürgen Schmidhuber

1996-01-01T23:59:59.000Z

165

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

E-Print Network (OSTI)

An irreversible cycle model of a heat pump operating between two variable-temperature heat reservoirs is established and used to analyze the performance of the heat pump affected by heat resistances, heat leakage and internal dissipation of the working substance. The coefficient of performance of the heat pump is optimized for a given heating load. The characteristic curves of the coefficient of performance versus power input are generated. The influence of intake temperatures of heat reservoirs, thermal capacity of heat reservoirs, efficiency of heat exchangers, heat leak and internal irreversibilities on the performance of the system is discussed. The optimal ratio of the times spent on two processes of heat transfer to and from the working substance is determined. Some new results which are conducive to the optimal design and operation of real heat pump systems are obtained.

Huang, Y.; Sun, D.

2006-01-01T23:59:59.000Z

166

Intrinsically irreversible heat engine  

DOE Patents (OSTI)

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

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

1984-12-25T23:59:59.000Z

167

Intrinsically irreversible heat engine  

DOE Patents (OSTI)

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

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

1984-01-01T23:59:59.000Z

168

Intrinsically irreversible heat engine  

DOE Patents (OSTI)

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

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

1984-01-01T23:59:59.000Z

169

Consumer Winter Heating Oil Costs  

Gasoline and Diesel Fuel Update (EIA)

5 5 Notes: Using the Northeast as a regional focus for heating oil, the typical oil-heated household consumes about 680 gallons of oil during the winter, assuming that weather is "normal." The previous three winters were warmer than average and generated below normal consumption rates. Last winter, consumers saw large increases over the very low heating oil prices seen during the winter of 1998-1999 but, outside of the cold period in late January/early February they saw relatively low consumption rates due to generally warm weather. Even without particularly sharp cold weather events this winter, we think consumers are likely to see higher average heating oil prices than were seen last winter. If weather is normal, our projections imply New England heating oil

170

Plasma heating from alpha particle micro-instabilities  

Science Conference Proceedings (OSTI)

Potential use of thermonuclear (i.e., fusion product) driven kinetic instabilities to heat the background plasma has long been recognized. Considerable research on velocity space micro-instabilities exists. Most work to date has focused upon the basic physics criteria for and characteristics of particular micro-instabilities. Kinetic instabilities resulting in spatial transport of fusion products have also received some attention, but the effects on reactor concepts and performance remain uncertain. We have developed an engineering model which scopes the effect of a velocity space relaxation of fast alphas on a quasi-linear time scale. This model includes the additional heating to background plasma ions under the assumptions of: ion damping of the plasma wave; heating to background plasma results predominantly from fusion products; and periodic hiccups of the instability.

Miley, G.H.; Sutton, W.R.; Choi, C.K.

1981-01-01T23:59:59.000Z

171

Self-heating in kinematically complex magnetohydrodynamic flows  

SciTech Connect

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.

Osmanov, Zaza; Rogava, Andria [Centre for Theoretical Astrophysics, ITP, Ilia State University, 0162-Tbilisi (Georgia); Poedts, Stefaan [Centre for Plasma Astrophysics, Katholieke Universiteit Leuven, Celestijnenlaan 200B, Bus 2400 B-3001 (Belgium)

2012-01-15T23:59:59.000Z

172

Effective Rate Period  

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

Fiscal Year 2014 Fiscal Year 2014 Effective Rate Period As of Beginning of the FY 10/01/2013 - 09/30/2014 Mid-Year Changes (if applicable) 10/01/2013 - 09/30/2014 Power Rates Annual Revenue Requirement Rate Schedule Power Revenue Requirement $73,441,557 CV-F13 Base Resource Revenue Requirement $69,585,875 First Preference Revenue Requirement $3,855,682

173

HEAT GENERATION  

DOE Patents (OSTI)

Heat is generated by the utilization of high energy neutrons produced as by nuclear reactions between hydrogen isotopes in a blanket zone containing lithium, a neutron moderator, and uranium and/or thorium effective to achieve multtplicatton of the high energy neutron. The rnultiplied and moderated neutrons produced react further with lithium-6 to produce tritium in the blanket. Thermal neutron fissionable materials are also produced and consumed in situ in the blanket zone. The heat produced by the aggregate of the various nuclear reactions is then withdrawn from the blanket zone to be used or otherwise disposed externally. (AEC)

Imhoff, D.H.; Harker, W.H.

1963-12-01T23:59:59.000Z

174

Dynamics of global ocean heat transport variability  

E-Print Network (OSTI)

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 ...

Jayne, Steven Robert

1999-01-01T23:59:59.000Z

175

Impacts of Water Quality on Residential Water Heating Equipment  

SciTech Connect

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

Widder, Sarah H.; Baechler, Michael C.

2013-11-01T23:59:59.000Z

176

PIA - Northeast Home Heating Oil Reserve System (Heating Oil...  

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

Northeast Home Heating Oil Reserve System (Heating Oil) PIA - Northeast Home Heating Oil Reserve System (Heating Oil) PIA - Northeast Home Heating Oil Reserve System (Heating Oil)...

177

PIA - Northeast Home Heating Oil Reserve System (Heating Oil...  

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

PIA - Northeast Home Heating Oil Reserve System (Heating Oil) PIA - Northeast Home Heating Oil Reserve System (Heating Oil) PIA - Northeast Home Heating Oil Reserve System (Heating...

178

Heat exchanger  

DOE Patents (OSTI)

A heat exchanger of the straight tube type in which different rates of thermal expansion between the straight tubes and the supply pipes furnishing fluid to those tubes do not result in tube failures. The supply pipes each contain a section which is of helical configuration.

Wolowodiuk, Walter (New Providence, NJ)

1976-01-06T23:59:59.000Z

179

Heat reclaimer  

Science Conference Proceedings (OSTI)

A heat reclaimer for the exhaust flue of a heating unit comprises a housing having an air input space, an air output space, and an exhaust space, with a plurality of tubes connected between and communicating the air input space with the air output space and extending through the exhaust space. The exhaust flue of the heating unit is connected into the exhaust space of the housing and an exhaust output is connected to the housing extending from the exhaust space for venting exhaust coming from the heater into the exhaust space to a chimney, for example. A float or level switch is connected to the housing near the bottom of the exhaust space for switching, for example, an alarm if water accumulates in the exhaust space from condensed water vapor in the exhaust. At least one hole is also provided in the housing above the level of the float switch to permit condensed water to leave the exhaust space. The hole is provided in case the float switch clogs with soot. A wiping device may also be provided in the exhaust space for wiping the exterior surfaces of the tubes and removing films of water and soot which might accumulate thereon and reduce their heat transfer capacity.

Bellaff, L.

1981-10-20T23:59:59.000Z

180

Time-Mean Flow as the Prevailing Contribution to the Poleward Heat Flux across the Southern Flank of the Antarctic Circumpolar Current: A Case Study in the Fawn Trough, Kerguelen Plateau  

Science Conference Proceedings (OSTI)

The major mechanisms of the oceanic poleward heat flux in the Southern Ocean are still in debate. The long-standing belief stipulates that the poleward heat flux across the Antarctic Circumpolar Current (ACC) is mainly due to mesoscale transient ...

H. Sekma; Y.-H. Park; F. Vivier

2013-03-01T23:59:59.000Z

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


181

Field Measurements of Heating System Efficiency in Nine Electrically-Heated Manufactured Homes.  

Science Conference Proceedings (OSTI)

This report presents the results of field measurements of heating efficiency performed on nine manufactured homes sited in the Pacific Northwest. The testing procedure collects real-time data on heating system energy use and heating zone temperatures, allowing direct calculation of heating system efficiency.

Davis, Bob; Siegel, J.; Palmiter, L.; Baylon, D.

1996-07-01T23:59:59.000Z

182

On occult period maps  

E-Print Network (OSTI)

We consider the "occult" period maps into ball quotients which exist for the moduli spaces of cubic surfaces, cubic threefolds, non-hyperelliptic curves of genus three and four. These were constructed in the work of Allcock/Carlson/Toledo, Looijenga/Swierstra, and Kondo. We interpret these maps as morphisms into moduli spaces of polarized abelian varieties of Picard type, and show that these morphisms, whose initial construction is transcendental, are defined over the natural field of definition of the spaces involved. This paper is extracted from section 15 of our paper arXiv:0912.3758, and differs from it only in some points of exposition.

Kudla, Stephen

2012-01-01T23:59:59.000Z

183

EFFECT OF HEATING RATE ON THE THERMODYNAMIC PROPERTIES OF PULVERIZED COAL  

SciTech Connect

This semi-annual technical progress report describes work performed under DOE Grant No. DE-FG22-96PC96224 during the period September 24, 1998 to March 23, 1999 which covers the fifth six months of the project. Devolatilization is an important initial step in virtually all commercial fossil fuel applications such as combustion, gasification, and liquefaction. Characterization of the temperature history of pulverized coal particles under high heating rates, representative of coal combustors, is critical to the understanding of devolatilization. During this reporting period, characterization experiments were continued from the previous reporting period and completed to a total of 28 single coal particles. These particles were caught in the electrodynamic balance and their volume, external surface area, mass, and density were measured. The same single particles were then heated bidirectionally with a pulsed (10 ms pulse width) Nd:YAG laser beams of equal intensity with heating rates (10{sup 4} - 10{sup 7} K/s) representative of coal combustors. The temporal power variation in the laser pulse was monitored for use in the heat transfer analysis by an ultra-fast fiber optic uv light transmitter included in the beam path and coupled to a silicon photodiode. Transient surface temperatures of the particles were measured using a single-color pyrometer. Dynamics of volatile evolution and particle swelling were recorded using well established time-resolved high-speed cinematography. Presently, extraction of devolatilization time-scales and temperature data at these time-scales running the high-speed films taken during the experiments employing a 16mm movie projector are in progress. Heat transfer analyses for the devolatilization time-scales, and temperature measurements (and hence an understanding of the effect of heating rates on coal thermal properties) are also in progress. Shipment of the donated heated grid system components from our industrial partner, United Technologies Research Center (UTRC), CT to CAU was complete during the previous reporting period. Testing of the heated grid system components at CAU and sensitivity analyses of the heated grid heat transfer calculations are also in progress.

Ramanathan Sampath

1999-04-29T23:59:59.000Z

184

Energy Basics: Absorption Heat Pumps  

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

Systems Air-Source Heat Pumps Ductless Mini-Split Heat Pumps Absorption Heat Pumps Geothermal Heat Pumps Supporting Equipment for Heating & Cooling Systems Water Heating...

185

Energy Basics: Geothermal Heat Pumps  

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

Systems Air-Source Heat Pumps Ductless Mini-Split Heat Pumps Absorption Heat Pumps Geothermal Heat Pumps Supporting Equipment for Heating & Cooling Systems Water Heating...

186

Periodic Solutions in Low-Dimensional Climatic Models  

Science Conference Proceedings (OSTI)

Classic climatic models use constitutive laws without any response time. A more realistic approach to the natural processes governing climate dynamics must introduce response time for heat and radiation fluxes. Extended irreversible ...

Toni Pujol; Josep Enric Llebot

1999-02-01T23:59:59.000Z

187

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  

Science Conference Proceedings (OSTI)

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

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

2010-03-01T23:59:59.000Z

188

Heat Distribution Systems | Department of Energy  

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

Distribution Systems Distribution Systems Heat Distribution Systems May 16, 2013 - 5:26pm Addthis Radiators are used in steam and hot water heating. | Photo courtesy of ©iStockphoto/Jot Radiators are used in steam and hot water heating. | Photo courtesy of ©iStockphoto/Jot Heat is distributed through your home in a variety of ways. Forced-air systems use ducts that can also be used for central air conditioning and heat pump systems. Radiant heating systems also have unique heat distribution systems. That leaves two heat distribution systems -- steam radiators and hot water radiators. Steam Radiators Steam heating is one of the oldest heating technologies, but the process of boiling and condensing water is inherently less efficient than more modern systems, plus it typically suffers from significant lag times between the

189

Latent Heat Induced Energy Transformations during Cyclogenesis  

Science Conference Proceedings (OSTI)

Using real-data numerical simulation experiments, latent heat induced energy transformations during the development of the wave cyclone of 20 May 1977 are investigated. During a 24 h period over 5 cm of precipitation fell despite baroclinically ...

C. B. Chang; D. J. Pepkey; C. W. Kreitzberg

1984-02-01T23:59:59.000Z

190

New York Heat Content of Natural Gas Consumed  

U.S. Energy Information Administration (EIA)

Heat Content of Natural Gas Consumed (Btu per Cubic Foot) Area: Period: Annual : Download Series History: Definitions, Sources & Notes: Show Data ...

191

U.S. Heat Content of Natural Gas Consumed  

U.S. Energy Information Administration (EIA)

Heat Content of Natural Gas Consumed (Btu per Cubic Foot) Area: Period: Annual : Download Series History: Definitions, Sources & Notes: Show Data By: Data Series ...

192

NONPARAMETRIC BAYESIAN ESTIMATION OF PERIODIC LIGHT CURVES  

SciTech Connect

Many astronomical phenomena exhibit patterns that have periodic behavior. An important step when analyzing data from such processes is the problem of identifying the period: estimating the period of a periodic function based on noisy observations made at irregularly spaced time points. This problem is still a difficult challenge despite extensive study in different disciplines. This paper makes several contributions toward solving this problem. First, we present a nonparametric Bayesian model for period finding, based on Gaussian Processes (GPs), that does not make assumptions on the shape of the periodic function. As our experiments demonstrate, the new model leads to significantly better results in period estimation especially when the light curve does not exhibit sinusoidal shape. Second, we develop a new algorithm for parameter optimization for GP which is useful when the likelihood function is very sensitive to the parameters with numerous local minima, as in the case of period estimation. The algorithm combines gradient optimization with grid search and incorporates several mechanisms to overcome the high computational complexity of GP. Third, we develop a novel approach for using domain knowledge, in the form of a probabilistic generative model, and incorporate it into the period estimation algorithm. Experimental results validate our approach showing significant improvement over existing methods.

Wang Yuyang; Khardon, Roni [Department of Computer Science, Tufts University, Medford, MA (United States); Protopapas, Pavlos [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)

2012-09-01T23:59:59.000Z

193

Heat Exchangers  

Science Conference Proceedings (OSTI)

Table 16   Ceramic heat exchanger systems...Soaking pit 870â??1230 1600â??2250 Fe, Si, alkalis Solar Turbines â?¦ 4â??8 OD Ă? 180 long (440 tubes) Aluminum melt furnaces 1010 1850 Alkali salts Plate fin GTE 0.6, 1.6 25â??46 Multiple 870â??1370 1600â??2250 Clean (good), alkalis (poor) Coors 0.25, 1.0 30 Ă? 30 Ă? 46 Multiple Clean (good), alkalis (poor) Radiant...

194

ABSORPTION HEAT PUMP IN THE DISTRICT HEATING  

E-Print Network (OSTI)

#12;ABSORPTION HEAT PUMP IN THE DISTRICT HEATING PLANT Dr.sc.ing. Agnese Lickrastina M.Sc. Normunds European Heat Pump Summit 2013, Nuremberg, 15-16.10.2013 · Riga District Heating company · Operation #12;JSC RGAS SILTUMS · the biggest District Heating company in Latvia and in the Baltic states

Oak Ridge National Laboratory

195

Electrically heated liquid tank employing heat pipe heat transfer means  

SciTech Connect

The heating apparatus for applying heat to the interior of a chamber includes a modular, removable, electrical, heat-producing unit and a heat pipe mountable in a wall of the chamber with one end of the pipe arranged to receive heat from the electrical heat producing unit exterior of the housing and with another end of the pipe constructed and arranged to apply heat to the medium within the chamber. The heat pipe has high conductivity with a low temperature differential between the ends thereof and the heat producing unit includes an electric coil positioned about and removably secured to the one end of the heat pipe. The electric coil is embedded in a high thermal conducitivity, low electrical conductivity filler material which is surrounded by a low thermal conductivity insulating jacket and which is received around a metal core member which is removably secured to the one end of the heat pipe.

Shutt, J.R.

1978-12-26T23:59:59.000Z

196

Solar heat collector  

SciTech Connect

A solar heat collector comprises an evacuated transparent pipe; a solar heat collection plate disposed in the transparent pipe; a heat pipe, disposed in the transparent pipe so as to contact with the solar heat collection plate, and containing an evaporable working liquid therein; a heat medium pipe containing a heat medium to be heated; a heat releasing member extending along the axis of the heat medium pipe and having thin fin portions extending from the axis to the inner surface of the heat medium pipe; and a cylindrical casing surrounding coaxially the heat medium pipe to provide an annular space which communicates with the heat pipe. The evaporable working liquid evaporates, receiving solar heat collected by the heat collection plate. The resultant vapor heats the heat medium through the heat medium pipe and the heat releasing member.

Yamamoto, T.; Imani, K.; Sumida, I.; Tsukamoto, M.; Watahiki, N.

1984-04-03T23:59:59.000Z

197

Geothermal district heating systems  

DOE Green Energy (OSTI)

Ten district heating demonstration projects and their present status are described. The projects are Klamath County YMCA, Susanville District Heating, Klamath Falls District Heating, Reno Salem Plaza Condominium, El Centro Community Center Heating/Cooling, Haakon School and Business District Heating, St. Mary's Hospital, Diamond Ring Ranch, Pagosa Springs District Heating, and Boise District Heating.

Budney, G.S.; Childs, F.

1982-01-01T23:59:59.000Z

198

Field Measurements of Heating Efficiency of Electric Forced-Air Furnaces in Six Manufactured Homes.  

Science Conference Proceedings (OSTI)

This report presents the results of field measurements of heating efficiency for six manufactured homes in the Pacific Northwest heated with electric forced-air systems. This is the first in a series of regional and national efforts to measure in detail the heating efficiency of manufactured homes. Only six homes were included in this study because of budgetary constraints; therefore this is not a representative sample. These investigations do provide some useful information on the heating efficiency of these homes. Useful comparisons can be drawn between these study homes and site-built heating efficiencies measured with a similar protocol. The protocol used to test these homes is very similar to another Ecotope protocol used in the study conducted in 1992 and 1993 for the Bonneville Power Administration to test the heating efficiency of 24 homes. This protocol combined real-time power measurements of furnace energy usage with energy usage during co-heat periods. Accessory data such as house and duct tightness measurements and tracer gas measurements were used to describe these homes and their heating system efficiency. Ensuring that manufactured housing is constructed in an energy and resource efficient manner is of increasing concern to manufactured home builders and consumers. No comparable work has been done to measure the heating system efficiency of MCS manufactured homes, although some co-heat tests have been performed on manufactured homes heated with natural gas to validate HUD thermal standards. It is expected that later in 1994 more research of this kind will be conducted, and perhaps a less costly and less time-consuming method for testing efficiencies will be develops.

Davis, Bob; Palmiter, Larry S.; Siegel, Jeff

1994-07-26T23:59:59.000Z

199

Heat pump system  

DOE Patents (OSTI)

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

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

1982-01-01T23:59:59.000Z

200

Heat pump system  

DOE Patents (OSTI)

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

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

1979-01-01T23:59:59.000Z

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


201

Gauge Interaction as Periodicity Modulation  

E-Print Network (OSTI)

The paper is devoted to a geometrical interpretation of gauge invariance in terms of the formalism of field theory in compact space-time dimensions [arXiv:0903.3680]. In this formalism, the kinematic information of an interacting elementary particle is encoded on the relativistic geometrodynamics of the boundary of the theory through local transformations of the underlying space-time coordinates. Therefore, gauge interaction is described as invariance of the theory under local deformations of the boundary, the resulting local variations of field solution are interpreted as internal transformations, and the internal symmetries of the gauge theory turn out to be related to corresponding local space-time symmetries. In the case of local infinitesimal isometric transformations, Maxwell's kinematics and gauge invariance are inferred directly from the variational principle. Furthermore we explicitly impose periodic conditions at the boundary of the theory as semi-classical quantization condition in order to investigate the quantum behavior of gauge interaction. In the abelian case the result is a remarkable formal correspondence with scalar QED.

Donatello Dolce

2011-10-03T23:59:59.000Z

202

ARM - Measurement - Radiative heating rate  

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

govMeasurementsRadiative heating rate govMeasurementsRadiative heating rate ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Radiative heating rate The heating rate due to the divergence of long and shortwave radiative flux. Categories Radiometric, Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. External Instruments MOLTS : Model Output Location Time Series Datastreams MOLTS : Model Output Location Time Series Datastreams MOLTSEDASSNDCLASS1 : Model Output Loc. Time Ser. (MOLTS): EDAS

203

Heat transfer and heat exchangers reference handbook  

Science Conference Proceedings (OSTI)

The purpose of this handbook is to provide Rocky Flats personnel with an understanding of the basic concepts of heat transfer and the operation of heat exchangers.

Not Available

1991-01-15T23:59:59.000Z

204

Heating systems for heating subsurface formations  

Science Conference Proceedings (OSTI)

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

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

2011-04-26T23:59:59.000Z

205

Heat Transfer In Turbine Mid Structures.  

E-Print Network (OSTI)

??In order to estimate the life time of a cooled gas turbine component, knowledge of the heat transfer is essential in order to predict the… (more)

Abou-Taouk, Abdallah

2006-01-01T23:59:59.000Z

206

Heat exchanger  

DOE Patents (OSTI)

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

Brackenbury, Phillip J. (Richland, WA)

1986-01-01T23:59:59.000Z

207

PERIODIC GLOW DISCHARGE REPORT  

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

GLOW DISCHARGE REPORT GLOW DISCHARGE REPORT TIME: Jan 11 2014 11:29:09:000PM Power Supply ON/OFF Status OFF Power Supply Fault Status FAULT Power Supply Standby Status ON Power Supply Interlock Status NOT OK HV Power Resistors Status NORMAL Power Supply Voltage 52.00 Power Supply Current -71.00 Electrode 1 Voltage -15.00 Electrode 1 Current -79.00 Electrode 2 Voltage -14.00 Electrode 2 Current -70.00 ROSS 1 Status OPEN ROSS 2 Status OPEN ROSS 1 Common Line OPEN ROSS 2 Common Line OPEN IGBT1 Enable DISABLE IGBT2 Enable DISABLE

208

Radiofrequency plasma heating: proceedings  

SciTech Connect

The conference proceedings include sessions on Alfven Wave Heating, ICRF Heating and Current Drive, Lower Hybrid Heating and Current Drive, and ECRF Heating. Questions of confinement, diagnostics, instabilities and technology are considered. Individual papers are cataloged separately. (WRF)

Swenson, D.G. (ed.)

1985-01-01T23:59:59.000Z

209

Ceramic technology for advanced heat engines  

DOE Green Energy (OSTI)

The Ceramic Technology Project was initiated in 1983 for the purpose of developing highly reliable structural ceramics for applications in advanced heat engines, such as automotive gas turbines and advanced heavy duty diesel engines. The reliability problem was determined to be a result of uncontrolled populations of processing flaws in the brittle, flaw-sensitive materials, along with microstructural features, such as grain boundary phases, that contribute to time dependent strength reduction in service at high temperatures. The approaches taken to develop high reliability ceramics included the development of tougher materials with greater tolerance to microstructural flaws, the development of advanced processing technology to minimize the size and number of flaws, and the development of mechanical testing methodology and the characterization of time dependent mechanical behavior, leading to a life prediction methodology for structural ceramics. The reliability goals of the program were largely met by 1993, but commercial implementation of ceramic engine components has been delayed by the high cost of the components. A new effort in Cost Effective Ceramics for Heat Engines was initiated in 1993 and is expected to develop the manufacturing technology leading to an order of magnitude cost reduction. The program has been planned for a five year period.

Johnson, D.R. [Oak Ridge National Lab., TN (United States); Schulz, R.B. [Dept. of Energy, Washington, DC (United States)

1994-10-01T23:59:59.000Z

210

Photovoltaic roof heat flux  

E-Print Network (OSTI)

and could the heat transfer processes be modeled to estimateindicating that the heat transfer processes were modeled w i

Samady, Mezhgan Frishta

2011-01-01T23:59:59.000Z

211

PERIODIC CRYO REPORT  

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

CRYO REPORT CRYO REPORT TIME: Jan 11 2014 11:29:09:000PM LN2 tank pressure, psi 63.00 LN2 main tank level,inch 48.05 LN2 resv tank level,inch 179.00 Cryostat pressure, psi 0.01 LN2 sump level, inch 0.00 LN2 pump speed, rpm 0.27 LN2 pump pressure, psi 0.00 Scanner OK DIBORANE SYSTEM CRYBOR CONC1 OK CRYBOR CONC2 OK CRYBOR INST1 OK CRYBOR INST2 OK RESISTANCE COIL TEMPERATURES, deg C EF1U, deg C 34.66 EF1L 21.94 EF2U 26.93 EF2L 21.70 EF3U 41.54 EF3L 36.42 EFCU 18.28 EFCL 8.16

212

Heat pipe methanator  

DOE Patents (OSTI)

A heat pipe methanator for converting coal gas to methane. Gravity return heat pipes are employed to remove the heat of reaction from the methanation promoting catalyst, transmitting a portion of this heat to an incoming gas pre-heat section and delivering the remainder to a steam generating heat exchanger.

Ranken, William A. (Los Alamos, NM); Kemme, Joseph E. (Los Alamos, NM)

1976-07-27T23:59:59.000Z

213

Heat reclaimer for a heat pump  

Science Conference Proceedings (OSTI)

This invention relates to a heat reclaiming device for a heat pump. The heat reclaimer is able to absorb heat from the compressor by circulating cooling fluid through a circuit which is mounted in good heat transfer relationship with the condenser, then around the shell of the motor-compressor and lastly around the hollow tube which connects the condenser to the compressor. The reclaiming circuit is connected into a fluid circulating loop which is used to supply heat to the evaporator coil of the heat pump.

Beacham, W.H.

1981-02-03T23:59:59.000Z

214

Segmented heat exchanger  

DOE Patents (OSTI)

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

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

2010-12-14T23:59:59.000Z

215

Dual source heat pump  

DOE Patents (OSTI)

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

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

1982-01-01T23:59:59.000Z

216

THE ORBITAL PERIOD OF SCORPIUS X-1  

Science Conference Proceedings (OSTI)

The orbital period of Sco X-1 was first identified by Gottlieb et al. While this has been confirmed on multiple occasions, this work, based on nearly a century of photographic data, has remained the reference in defining the system ephemeris ever since. It was, however, called into question when Vanderlinde et al. claimed to find the one-year alias of the historical period in RXTE/All-Sky Monitor data and suggested that this was the true period rather than that of Gottlieb et al. We examine data from the All Sky Automated Survey (ASAS) spanning 2001-2009. We confirm that the period of Gottlieb et al. is in fact the correct one, at least in the optical, with the one-year alias strongly rejected by these data. We also provide a modern time of minimum light based on the ASAS data.

Hynes, Robert I.; Britt, Christopher T., E-mail: rih@phys.lsu.edu [Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Tower Drive, Baton Rouge, LA 70803 (United States)

2012-08-10T23:59:59.000Z

217

The Structure of the Arabian Heat Low. Part II: Bulk Tropospheric Heat Budget and Implications  

Science Conference Proceedings (OSTI)

An investigation of the Arabian heat low is carried out based on observations from various satellites, an experimental aircraft and a surface energy budget monitoring station. The observations suggest that during the spring period the Arabian ...

Eric A. Smith

1986-06-01T23:59:59.000Z

218

Periodicity estimation of Dynamic Textures  

Science Conference Proceedings (OSTI)

Dynamic Textures (DTs) are image sequences of natural events like fire, smoke, water etc., that possesses regular motion patterns. Periodicity is a widely used tool to analyse regular structures of periodic one dimensional signals as well as two dimensional ... Keywords: co-occurrence matrix, dynamic textures, image sequences, image texture analysis, motion patterns, natural events, periodicity estimation, temporal textures

Khalid Zaman Bijon; Ahmed Hasan; Ashfaqur Rahman; Manzur Murshed

2008-03-01T23:59:59.000Z

219

Industrial and Commercial Heat Pump Applications in the United States  

E-Print Network (OSTI)

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 the trends in heat pump cycle developments and discusses both the closed vapor compression cycle and refrigerants most commonly used and the open-cycle mechanical vapor compression heat pumps. Waste heat sources, heat loads served by heat pumps--and typical applications using heat pumps for large-scale space heating, domestic water heating, and industrial process water heating-- are discussed. Typical installations include commercial applications in hotels, high-rise apartments and condominiums, and office buildings. Institutional installations discussed include hospitals, universities, wastewater treatment plants, and airport terminals. Industrial applications largely center on food processing industries, feedwater heating, metal fabricating, and other industries. Reference is also made to other applications and alternative energy sources now gaining acceptance, including groundwater/geothermal water.

Niess, R. C.

1986-06-01T23:59:59.000Z

220

Solar heating and cooling systems design and development: quarterly report  

DOE Green Energy (OSTI)

The progress of the program for the development and delivery of eight prototype solar heating and cooling systems for installation and operational test is described for the period, 1 January 1978 through 31 March 1978. Two heating and six heating and cooling units will be delivered for single-family residences, multiple-family residences, and commercial applications.

Not Available

1978-07-01T23:59:59.000Z

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


221

Super Gabor frames on discrete periodic sets  

Science Conference Proceedings (OSTI)

Due to its potential applications in multiplexing techniques such as time division multiple access and frequency division multiple access, superframe has interested some mathematicians and engineering specialists. In this paper, we investigate super ... Keywords: 42C40, Discrete Zak transform, Discrete periodic sets, Gabor dual, Super Gabor frame, Superframe

Yun-Zhang Li; Qiao-Fang Lian

2013-05-01T23:59:59.000Z

222

Handbook of heat and mass transfer. Volume 1  

Science Conference Proceedings (OSTI)

This two-volume series, the work of more than 100 contributors, presents advanced topics in industrial heat and mass transfer operations and reactor design technology. Volume 1 emphasizes heat transfer operations. The contents are: Fundamentsls of momentum and heat transfer. Scaling in laminar and turbulent heat and mass transfer. Heat flux in the Benar-Rayleigh problem. Hydrodynamics of free liquid jets and their influence on heat transfer. Natural convection heat transfer to power law fluids. Natural convection in evaporating droplets. Principles of heat and mass transfer with liquid evaporation. Bubble nucleation, growth, and departure in boiling heat transfer. Forced convection boiling in uniformly heated channels. Transient boiling heat transfer under forced convection. Prediction of heat transfer during forced convection subcooled boiling. Liquid metal heat transfer in turbulent pipe flows. Mixed convection in buoyant plumes. Nucleation and growth in the diffusion cloud chamber. Convective and radiative heat transfer of flowing gaseous-solid suspensions. Heat transfer in gas-solid fluidized beds. Gas convection and unsteady conduction in fluid bed heat transfer. Heat transfer between tubes and gas-solid fluid beds. Periodic heat transfer through inhomogeneous layers.

Cheremisinoff, N.P.

1986-01-01T23:59:59.000Z

223

Novel heat pipe combination  

SciTech Connect

The basic heat pipe principle is employed in a heat pipe combination wherein two heat pipes are combined in opposing relationship to form an integral unit; such that the temperature, heat flow, thermal characteristics, and temperature-related parameters of a monitored environment or object exposed to one end of the heat pipe combination can be measured and controlled by controlling the heat flow of the opposite end of the heat pipe combination.

Arcella, F.G.

1978-01-10T23:59:59.000Z

224

High Operating Temperature Liquid Metal Heat Transfer Fluids  

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

Liquid Metal Liquid Metal Heat Transfer Fluids UCLA, UCB, Yale DE-EE0005941 | April 15, 2013 | Ju 1.1 Thermochemistry modeling * Continue CALPHAD based calculations to search for optimal ternary alloy compositions. * Initiate development of liquid density models. 1.2 Combinatorial synthesis and characterization * Pipe-Liquid interaction of compositional library * More alloys, alloy additions and effect on liquidus temperatures * Iteratively optimize the compositions. 1.3 Corrosion characterization and mitigation * Tune static corrosion testing systems for testing over an extended period of time. * Perform analysis of the micro mechanical testing on the oxide layers. 1.4 Heat transfer characterization and modeling * Complete the construction of the flow loop and perform experiments to measure

225

Multiple source heat pump  

DOE Patents (OSTI)

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

Ecker, Amir L. (Duncanville, TX)

1983-01-01T23:59:59.000Z

226

The periodicity of the eta Carinae events  

E-Print Network (OSTI)

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.

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

227

Heat Pump Water Heating Modeling in EnergyPlus  

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

Heat Pump Water Heater Modeling Heat Pump Water Heater Modeling in EnergyPlus Building America Residential Energy Efficiency Stakeholder Meeting Eric Wilson Craig Christensen March 1, 2012 2 Modeling Issues Results Motivation Heat Pump Water Heater Modeling... 3 Gap: Existing analysis tools cannot accurately model HPWHs with reasonable runtime. 4 What have we achieved so far? Laboratory Evaluations 14 x Field Monitoring 5 Closing the Gap Laboratory Evaluations 6 sec timestep hourly timestep 14 x Field Monitoring CARB 6 Why is modeling important? * Performance varies: Can't just use EF * System interaction o HPWH affects building heating and cooling o Space conditions affect HPWH performance 7 Modeling Goals * Manage Risks o Accuracy o Run time o Occupant satisfaction * Flexibility to explore the effects of:

228

Shock Dynamics in Layered Periodic Media  

E-Print Network (OSTI)

Solutions of constant-coefficient nonlinear hyperbolic PDEs generically develop shocks, even if the initial data is smooth. Solutions of hyperbolic PDEs with variable coefficients can behave very differently. We investigate formation and stability of shock waves in a one-dimensional periodic layered medium by computational study of time-reversibility and entropy evolution. We find that periodic layered media tend to inhibit shock formation. For small initial conditions and large impedance variation, no shock formation is detected even after times much greater than the time of shock formation in a homogeneous medium. Furthermore, weak shocks are observed to be dynamically unstable in the sense that they do not lead to significant long-term entropy decay. We propose a characteristic condition for admissibility of shocks in heterogeneous media that generalizes the classical Lax entropy condition and accurately predicts the formation or absence of shocks in these media.

David I Ketcheson; Randall J. LeVeque

2011-05-14T23:59:59.000Z

229

Coupling light to periodic nanostructures.  

E-Print Network (OSTI)

??This thesis describes coupling of light to periodic structures. A material is patterned with a regular pattern on a length scale comparable to the wavelength… (more)

Driessen, Eduard Frans Clemens

2009-01-01T23:59:59.000Z

230

Industrial Waste Heat Recovery Using Heat Pipes  

E-Print Network (OSTI)

For almost a decade now, heat pipes with secondary finned surfaces have been utilized in counter flow heat exchangers to recover sensible energy from industrial exhaust gases. Over 3,000 such heat exchangers are now in service, recovering an estimated energy equivalent of nearly 1.1 million barrels of oil annually. Energy recovered by these units has been used to either preheat process supply air or to heat plant comfort make-up air. Heat pipe heat exchangers have been applied to an ever-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 pipes. This device has a number of advantageous features. Field operational experience of several units in service has been excellent.

Ruch, M. A.

1981-01-01T23:59:59.000Z

231

EFFECT OF HEATING RATE ON THE THERMODYNAMIC PROPERTIES OF PULVERIZED COAL  

SciTech Connect

This semi-annual technical progress report describes work performed under DOE Grant No. DE-FG22-96PC96224 during the period March 24, 1998 to September 23, 1998 which covers the fourth six months of the project. Existing laser heating set-up at the Single Particle Laboratory, Federal Energy Technology Center, Morgantown, WV would work only in the range of 10 to 10 4 5 K/s. During this reporting period, appropriate changes were made to the laser heating system to heat particles in the range of 10 to 10 K/s. Also, calibration for all the components of the 4 7 electrodynamic balance measurement system including single-color pyrometer and heating laser was successfully completed. Following the calibration, a large number of single coal particles were caught in the electrodynamic balance and their volume, external surface area, mass, and density were measured. The same single particles were then heated bidirectionally with a pulsed (10 ms pulse width) Nd:YAG laser beams of equal intensity. The temporal power variation in the laser pulse was monitored for use in the heat transfer analysis by an ultra-fast fiber optic uv light transmitter included in the beam path and coupled to a silicon photodiode. Measurements of changes in particle size that accompanied rapid heating was made by means of the high-speed diode array imaging system discussed in our previous reports. Dynamics of volatile evolution and particle swelling were recorded using well established time-resolved high-speed cinematography. Measurements of the radiant emissive power from the heated and cooled (when the laser is turned off) particles was made using the single-color pyrometer. The above experiments are being repeated for a significant number of coal particles for a number of heating rates in between 10 - 10 K/s at FETC, Morgantown. 4 7 Shipment of the donated heated grid system components from our industrial partner, United Technologies Research Center (UTRC), CT to CAU was complete during this reporting period. Testing of the heated grid system components at CAU is also in progress.

RAMANATHAN SAMPATH

1998-10-27T23:59:59.000Z

232

Heat Pipe Technology for Energy Conservation in the Process Industry  

E-Print Network (OSTI)

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 range from residential and commercial air-to-air heat exchangers to giant air preheaters for the process 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 expertise in engineering heat recovery products for the process industry. This paper discusses two such products, the heat pipe air preheater and waste heat recovery boiler. These heat pipe products have been used in many successful installations all over the world and some important, distinctive features of these systems will be presented.

Price, B. L. Jr.

1985-05-01T23:59:59.000Z

233

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

E-Print Network (OSTI)

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

Antonio Mecozzi; Cristian Antonelli

2008-11-03T23:59:59.000Z

234

Hydrodynamical simulations of cluster formation with central AGN heating  

E-Print Network (OSTI)

We analyse a hydrodynamical simulation model for the recurrent heating of the central intracluster medium (ICM) by active galactic nuclei (AGN). Besides the self-gravity of the dark matter and gas components, our approach includes the radiative cooling and photoheating of the gas, as well as a subresolution multiphase model for star formation and supernova feedback. Additionally, we incorporate a periodic heating mechanism in the form of hot, buoyant bubbles, injected into the intragalactic medium (IGM) during the active phases of the accreting central AGN. We use simulations of isolated cluster halos of different masses to study the bubble dynamics and the heat transport into the IGM. We also apply our model to self-consistent cosmological simulations of the formation of galaxy clusters with a range of masses. Our numerical schemes explore a variety of different assumptions for the spatial configuration of AGN-driven bubbles, for their duty cycles and for the energy injection mechanism, in order to obtain better constraints on the underlying physical picture. We argue that AGN heating can substantially affect the properties of both the stellar and gaseous components of clusters of galaxies. Most importantly, it alters the properties of the central dominant (cD) galaxy by reducing the mass deposition rate of freshly cooled gas out of the ICM, thereby offering an energetically plausible solution to the cooling flow problem. At the same time, this leads to reduced or eliminated star formation in the central cD galaxy, giving it red stellar colours as observed.

Debora Sijacki; Volker Springel

2005-09-16T23:59:59.000Z

235

Periodic  

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

04 04 by C.G. Wohl (LBNL). Adapted from the Commission of Atomic Weights and Isotopic Abundances, "Atomic Weights of the Elements 1995," Pure and Applied Chemistry 68, 2339 (1996), and G. Audi and A.H. Wapstra, "The 1993 Mass Evaluation," Nucl. Phys. A565, 1 (1993). The atomic number (top left) is the number of protons in the nucleus. The atomic mass (bottom) is weighted by isotopic abundances in the Earth's surface. For a new determination of atomic masses, not weighted by abundances, see G. Audi, A.H. Wapstra, and C. Thibault, Nucl. Phys. A729, 337 (2003). Atomic masses are relative to the mass of the carbon-12 isotope, defined to be exactly 12 unified atomic mass units (u). Errors range from 1 to 9 in the last digit quoted. Relative isotopic abundances often vary considerably, both in natural and commercial samples. A number in parentheses is the mass of the longest-lived

236

Geothermal Heat Pumps  

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

Geothermal heat pumps use the constant temperature of the earth as an exchange medium for heat. Although many parts of the country experience seasonal temperature extremes—from scorching heat in...

237

Absorption heat pump system  

DOE Patents (OSTI)

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

Grossman, Gershon (Oak Ridge, TN)

1984-01-01T23:59:59.000Z

238

Absorption heat pump system  

DOE Patents (OSTI)

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

Grossman, G.

1982-06-16T23:59:59.000Z

239

SMALL PARTICLE HEAT EXCHANGERS  

E-Print Network (OSTI)

ON ~m Small Particle Heat Exchangers Arion J. Hunt June 1978d. LBL 7841 Small Particle Heat Exchangers by Arlon J. Huntgenerally to non-solar heat exchangers. These may be of the

Hunt, A.J.

2011-01-01T23:59:59.000Z

240

Heat Pump Systems  

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

Like a refrigerator, heat pumps use electricity to move heat from a cool space into a warm space, making the cool space cooler and the warm space warmer. Because they move heat rather than generate...

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


241

Photovoltaic roof heat flux  

E-Print Network (OSTI)

of ~24°C, indicating that heat conduction was small. T h i sday, indicating large heat conduction a n d storage. Control2.1.3 showed that conduction heat flux through the roof was

Samady, Mezhgan Frishta

2011-01-01T23:59:59.000Z

242

TRANSPARENT HEAT MIRRORS FOR PASSIVE SOLAR HEATING APPLICATIONS  

E-Print Network (OSTI)

for Passive Passive Solar Heating Applications StephenHEAT MIRRORS FOR PASSIVE SOLAR HEATING APPLICATIONS StephenMIRRORS FOR PASSIVE SOLAR HEATING APPLICATIONS Stephen

Selkowitz, S.

2011-01-01T23:59:59.000Z

243

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...

244

Midland District Heating District Heating Low Temperature Geothermal...  

Open Energy Info (EERE)

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

245

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...

246

San Bernardino District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

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

247

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...

248

Pagosa Springs District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

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

249

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

Open Energy Info (EERE)

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

250

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

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

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...

251

Synergistic Interactions between Urban Heat Islands and Heat Waves: the Impact in Cities is Larger than the Sum of its Parts  

Science Conference Proceedings (OSTI)

Cities are well known to be hotter than the rural areas that surround them; this phenomenon is called the “urban heat island”. Heat waves are excessively hot periods during which the air temperatures of both urban and rural areas increase ...

Dan Li; Elie Bou-Zeid

252

Synergistic Interactions between Urban Heat Islands and Heat Waves: The Impact in Cities Is Larger than the Sum of Its Parts  

Science Conference Proceedings (OSTI)

Cities are well known to be hotter than the rural areas that surround them; this phenomenon is called the urban heat island. Heat waves are excessively hot periods during which the air temperatures of both urban and rural areas increase ...

Dan Li; Elie Bou-Zeid

2013-09-01T23:59:59.000Z

253

Woven heat exchanger  

DOE Patents (OSTI)

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

Piscitella, R.R.

1984-07-16T23:59:59.000Z

254

Solar heat collector  

Science Conference Proceedings (OSTI)

A solar heat collector is described that pre-heats water for a household hot water heating system, and also heats the air inside a house. The device includes solar heating panels set into an A-shape, and enclosing an area therein containing a water tank and a wristatic fan that utilize the heat of the enclosed air, and transmit the thermal energy therefrom through a water line and an air line into the house.

Sykes, A.B.

1981-07-28T23:59:59.000Z

255

Discontinuous bifurcations of periodic solutions  

Science Conference Proceedings (OSTI)

This paper discusses different aspects of bifurcations of periodic solutions in discontinuous systems. It is explained how jumps in the fundamental solution matrix lead to jumps of the Floquet multipliers of periodic solutions. A Floquet multiplier of ... Keywords: Bifurcation, Discontinuous, Dry friction, Stick-slip

R. I. Leine; D. H. Van Campen

2002-08-01T23:59:59.000Z

256

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

E-Print Network (OSTI)

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

Paris-Sud XI, Université de

257

Energy Basics: Heating Systems  

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

of energy sources, including electricity, boilers, solar energy, and wood and pellet-fuel heating. Small Space Heaters Used when the main heating system is inadequate or when...

258

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 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...

259

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*...

260

Mass and Heat Recovery  

E-Print Network (OSTI)

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

Hindawai, S. M.

2010-01-01T23:59:59.000Z

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


261

Energy Basics: Water Heating  

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

Storage Water Heaters Tankless Demand Water Heaters Heat Pump Water Heaters Solar Water Heaters Tankless Coil & Indirect Water Heaters Water Heating A variety of...

262

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 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*...

263

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...

264

Urban Heat Catastrophes  

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

The curve shows the heat index, which reflects the combined effect of temperature and humidity. Last year's Chicago heat wave created a great deal of human discomfort and,...

265

Heat Pump for High School Heat Recovery  

E-Print Network (OSTI)

The heat pump system used for recycling and reusing waste heat in s high school bathroom was minutely analyzed in its coefficient of performance, onetime utilization ratio of energy, economic property and so on. The results showed that this system has good economic property, can conserve energy and protects the environment. Therefore, there is a large potential for its development. In addition, three projects using this system are presented and contrasted, which indicate that a joint system that uses both the heat pump and heat exchanger to recycle waste heat is a preferable option.

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

2006-01-01T23:59:59.000Z

266

Geothermal heat pump analysis article  

U.S. Energy Information Administration (EIA)

heat pump transfers heat from the ground or ground water to provide space heating. In the summer, the heat transfer process is reversed; the ground or groundwater

267

Climate, extreme heat, and electricity demand in California  

SciTech Connect

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

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

2008-04-01T23:59:59.000Z

268

Comparison of an impedance heating system to mineral insulated heat trace for power tower applications  

DOE Green Energy (OSTI)

A non-conventional type of heating system is being tested at Sandia National Laboratories for solar thermal power tower applications. In this system, called impedance heating, electric current flows directly through the pipe to maintain the desired temperature. The pipe becomes the resistor where the heat is generated. Impedance heating has many advantages over previously used mineral insulated (MI) heat trace. An impedance heating system should be much more reliable than heat trace cable since delicate junctions and cabling are not used and the main component, a transformer, is inherently reliable. A big advantage of impedance heating is the system can be sized to rapidly heat up the piping to provide rapid response times necessary in cyclic power plants such as solar power towers. In this paper, experimental results from testing an impedance heating system are compared to MI heat trace. The authors found impedance heating was able to heat piping rapidly and effectively. There were not significant stray currents and impedance heating did not affect instrumentation.

Pacheco, J.E.; Kolb, W.J.

1997-03-01T23:59:59.000Z

269

STEO October 2012 - home heating supplies  

U.S. Energy Information Administration (EIA) Indexed Site

Natural gas, propane, and electricity supplies seen plentiful Natural gas, propane, and electricity supplies seen plentiful this winter for U.S. home heating Supplies of the major heating fuels used by most U.S. households are expected to be plentiful this winter, with the possible exception of heating oil, which is consumed mostly by households in the Northeast. Heating oil stocks are expected to be low in the East Coast and Gulf Coast states. And with New York state requiring heating oil with lower sulfur levels for the first time, the heating oil market is expected to be tighter this winter, according to the U.S. Energy Information Administration's new winter fuels forecast. However, U.S. inventories of natural gas, the most common primary heating fuel used by households and a key fuel for electricity generation, is expected to reach 3.9 trillion cubic feet by

270

Visual Simulation of Heat Shimmering and Mirage  

E-Print Network (OSTI)

Abstract — We provide a physically-based framework for simulating the natural phenomena related to heat interaction between objects and the surrounding air. We introduce a heat transfer model between the heat source objects and the ambient flow environment, which includes conduction, convection and radiation. The heat distribution of the objects is represented by a novel temperature texture. We simulate the thermal flow dynamics that models the air flow interacting with the heat by a hybrid thermal lattice Boltzmann model (HTLBM). The computational approach couples a multiple-relaxation-time LBM (MRTLBM) with a finite difference discretization of a standard advectiondiffusion equation for temperature. In heat shimmering and mirage, the changes in the index of refraction of the surrounding air are attributed to temperature variation. A nonlinear ray tracing method is used for rendering. Interactive performance is achieved by accelerating the computation of both the MRTLBM and the heat transfer, as well as the rendering on contemporary graphics hardware (GPU).

Ye Zhao; Yiping Han; Zhe Fan; Feng Qiu; Yu-chuan Kuo; Arie Kaufman; Klaus Mueller

2007-01-01T23:59:59.000Z

271

Heating and cooling of municipal buildings with waste heat from ground water  

DOE Green Energy (OSTI)

The feasibility of using waste heat from municipal water wells to replace natural gas for heating of the City Hall, Fire Station, and Community Hall in Wilmer, Texas was studied. At present, the 120/sup 0/F well water is cooled by dissipating the excess heat through evaporative cooling towers before entering the distribution system. The objective of the study was to determine the pumping cycle of the well and determine the amount of available heat from the water for a specified period. This data were correlated with the heating and cooling demand of the City's buildings, and a conceptual heat recovery system will be prepared. The system will use part or all of the excess heat from the water to heat the buildings, thereby eliminating the use of natural gas. The proposed geothermal retrofit of the existing natural gas heating system is not economical because the savings in natural gas does not offset the capital cost of the new equipment and the annual operating and maintenance costs. The fuel savings and power costs are a virtual trade-off over the 25-year period. The installation and operation of the system was estimated to cost $105,000 for 25 years which is an unamortized expense. In conclusion, retrofitting the City of Wilmer's municipal buildings is not feasible based on the economic analysis and fiscal projections as presented.

Morgan, D.S.; Hochgraf, J.

1980-10-01T23:59:59.000Z

272

Rotary magnetic heat pump  

DOE Patents (OSTI)

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

Kirol, Lance D. (Shelly, ID)

1988-01-01T23:59:59.000Z

273

Direct fired heat exchanger  

DOE Patents (OSTI)

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

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

1986-01-01T23:59:59.000Z

274

Woven heat exchanger  

DOE Patents (OSTI)

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

Piscitella, Roger R. (Idaho Falls, ID)

1987-01-01T23:59:59.000Z

275

Rotary magnetic heat pump  

DOE Patents (OSTI)

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

Kirol, L.D.

1987-02-11T23:59:59.000Z

276

Heating Oil and Propane Update  

Gasoline and Diesel Fuel Update (EIA)

Holiday Release Schedule Holiday Release Schedule The Heating Oil and Propane Update is produced during the winter heating season, which extends from October through March of each year. The standard release time and day of the week will be at 1:00 p. m. (Eastern time) on Wednesdays with the following exceptions. All times are Eastern. Data for: Alternate Release Date Release Day Release Time Holiday October 14, 2013 October 17, 2013 Thursday Cancelled Columbus/EIA Closed November 11, 2013 November 14, 2013 Thursday 1:00 p.m. Veterans December 23, 2013 December 27, 2013 Friday 1:00 p.m. Christmas December 30, 2013 January 3, 2014 Friday 1:00 p.m. New Year's January 20, 2014 January 23, 2014 Thursday 1:00 p.m. Martin Luther King Jr. February 17, 2014 February 20, 2014 Thursday 1:00 p.m. President's

277

Electrically heated DPF start-up strategy  

SciTech Connect

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

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

2012-04-10T23:59:59.000Z

278

No. 2 heating oil/propane program  

SciTech Connect

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

McBrien, J.

1991-06-01T23:59:59.000Z

279

Effect of Post-Weld Heat Treatment on Creep Properties of Grade 91 ...  

Science Conference Proceedings (OSTI)

Effect of heat treatment temperature and time on the creep life and minimum creep ... to Silicon Carbide Joints for Heat Exchanger and Component Integration .

280

Absorption cooling in district heating network: Temperature difference examination in hot water circuit.  

E-Print Network (OSTI)

?? Absorption cooling system driven by district heating network is relized as a smart strategy in Sweden. During summer time when the heating demand is… (more)

Yuwardi, Yuwardi

2013-01-01T23:59:59.000Z

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


281

The effect of drying on the heating value of biomass fuels  

E-Print Network (OSTI)

There has been some speculation as to whether or not biomass fuels (such as feedlot manure) may lose volatile matter during the drying process. Since current standards state that heating value analysis may be performed before or after drying, and volatile matter analysis can only be performed after drying, and since many fuel suppliers are paid on a heating value basis of the fuel, there has been some controversy in this matter. Furthermore, it is known that if manure is left out at ambient temperatures over long periods of time, the heating value decreases as well. It is therefore the objective of this work to ascertain if in fact volatile matter is lost during the drying or aging process and, if so, to find an optimum aging and /or drying time and to model the loss of volatile matter. It has been found that, if indeed there is volatile matter loss over the drying process, then it is so small as to be negligible. Furthermore, no appreciable amount of volatile loss occurs even if the fuel is dried for extensive amounts of time as are generally needed to obtain constant weight in the fuel sample. It has also been found that heating value decreases with aging time (falling even after only one to two days at atmospheric conditions), yet the heating value of an initial (undried) fuel sample increases with aging time. This is because moisture is lost as well as combustibles so the heat produced by the fuel will increase with a decrease in moisture even though volatiles are lost.

Rodriguez, Pablo Gregorio

1994-01-01T23:59:59.000Z

282

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

E-Print Network (OSTI)

Vacuum Induction Melting Unit Induction heating is a process wherein induced eddy currents heat can be melted at a time. There are three main parts to the system: chiller, power unit and vacuum unit. The vacuum unit with rotary and diffusion pumps can attain a vacuum of 106 m bar. The power can deliver

Subramaniam, Anandh

283

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

SciTech Connect

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

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

1998-03-01T23:59:59.000Z

284

Thulium-170 heat source  

DOE Patents (OSTI)

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

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

1992-01-01T23:59:59.000Z

285

Thulium-170 heat source  

SciTech Connect

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

Walter, C.E.; Van Konynenburg, R.; VanSant, J.H.

1990-09-06T23:59:59.000Z

286

Modeling twin-screw multiphase pump performance during periods of high gas volume fraction  

E-Print Network (OSTI)

Multiphase pumping is a new technology used for reducing capital investments, increasing production rates, and improving recoveries in many on-shore projects. Interest is also growing in the subsea/offshore application of this technology. Multiphase pumping adds energy to an unprocessed effluent stream acting as a combined pump and compressor, permitting the recovery of oil and gas on an economical basis. In practice, multiphase production is characterized by wide fluctuations in the gas and liquid mass flow rates. During periods of substantial gas flow, temperature becomes the critical variable determining the performance of the pump. Without the liquid phase to remove the gas compression heat, temperatures in the discharge gas stream begin to rise causing a decrease in efficiency, a high temperature shut-in of the pump, and damage to the pump. While this behavior has been observed in lab experiments and in the field, a review of literature reveals that no mechanistic model exists for predicting the performance of a twin-screw pump under high gas volume flow conditions. Also, very few data are available under high GVF conditions. Both large-scale experiments and mechanistic modeling were performed as part of this research. This thesis models the behavior of a twin-screw multiphase pump under high gas volume fraction conditions. The model of the pump is based on fundamental principles of thermodynamic and fluid mechanics. The specific experimental tasks undertaken in this work include studying the volumetric pump performance during periods of high gas volume fractions, the observation of temperature increase with time under periods of 100% gas volume fraction and studying the effect of viscosity on high GVF performance. The results indicate that the pump can be operated during periods of 100% gas volume fractions. The volumetric efficiency of the twin-screw multiphase pump during periods of high to 100% gas volume fractions can be improved by increasing the viscosity of the process stream or by injecting high viscosity fluids into the pump casing. At 94-95% gas volume fraction the system transitions from isothermal conditions. And the system moves from isothermal to adiabatic (uncooled) conditions with time. A model has been generated that predicts temperature increase with time as a function of the key parameters of pump speed, differential pressure, mass flow rate, specific heat and slip flow. This model can be used to develop novel control philosophies for operating multiphase pumps during high gas volume fractions.

Singh, Aditya

2003-01-01T23:59:59.000Z

287

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

SciTech Connect

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.

McBrien, J.

1995-05-01T23:59:59.000Z

288

Estimation of heat load in waste tanks using average vapor space temperatures  

SciTech Connect

This report describes a method for estimating the total heat load in a high-level waste tank with passive ventilation. This method relates the total heat load in the tank to the vapor space temperature and the depth of waste in the tank. Q{sub total} = C{sub f} (T{sub vapor space {minus}} T{sub air}) where: C{sub f} = Conversion factor = (R{sub o}k{sub soil}{sup *}area)/(z{sub tank} {minus} z{sub surface}); R{sub o} = Ratio of total heat load to heat out the top of the tank (function of waste height); Area = cross sectional area of the tank; k{sub soil} = thermal conductivity of soil; (z{sub tank} {minus} z{sub surface}) = effective depth of soil covering the top of tank; and (T{sub vapor space} {minus} T{sub air}) = mean temperature difference between vapor space and the ambient air at the surface. Three terms -- depth, area and ratio -- can be developed from geometrical considerations. The temperature difference is measured for each individual tank. The remaining term, the thermal conductivity, is estimated from the time-dependent component of the temperature signals coming from the periodic oscillations in the vapor space temperatures. Finally, using this equation, the total heat load for each of the ferrocyanide Watch List tanks is estimated. This provides a consistent way to rank ferrocyanide tanks according to heat load.

Crowe, R.D.; Kummerer, M.; Postma, A.K.

1993-12-01T23:59:59.000Z

289

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

SciTech Connect

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

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

1991-10-01T23:59:59.000Z

290

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

DOE Green Energy (OSTI)

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

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

1991-10-01T23:59:59.000Z

291

New directions for district heating in the United States  

DOE Green Energy (OSTI)

Within the past five years there has been a growing awareness of the energy conservation and economic advantages of modern hot-water district heating systems. A description is given of the status of major US district heating projects and the potential impact of the newly implemented US National District Heating Plan is examined. At the present time there are five major district heating projects moving into the construction and demonstration phase. Although all have hot water distribution systems a variety of heat sources are being utilized. These heat sources include geothermal water, industrial reject heat, and utility cogeneration using coal-fired power plants.

Olszewski, M.; Karnitz, M.A.

1981-01-01T23:59:59.000Z

292

Heat pipes for use in a magnetic field  

DOE Patents (OSTI)

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

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

1983-07-19T23:59:59.000Z

293

Heat pipes for use in a magnetic field  

DOE Patents (OSTI)

A heat pipe configuration is described for use in a magnetic field environment of a fusion reactor. 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 to 3 times the heat as a cylindrical heat pipe of the same cross sectional area.

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

1981-04-29T23:59:59.000Z

294

VLF versus MF heating of the lower ionosphere  

SciTech Connect

The perturbation in the signal strength of a VLF transmitter by another transmitter heating the ionosphere on the great circle path to the receiver is calculated for two cases: The NAA-Palmer path heated by the VLF transmitter, NAU, and the Omega Norway-Skibotn path heated by the MF transmitter, heating, near Tromsoe. Comparison implies either that VLF heating is over 100 times more effective than MF heating in terms of the perturbation produced, per RF heating watt, in VLF propagation in the Earth-ionosphere wave-guide or that the observed effect at Palmer is fortuitous or spurious.

Dowden, R.L.; Adams, C.D.D. (Univ. of Otago, Dunedin (New Zealand))

1991-08-01T23:59:59.000Z

295

Heat pipes for use in a magnetic field  

DOE Patents (OSTI)

A heat pipe configuration for use in a magnetic field environment of a fusion reactor. 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.

Werner, Richard W. (San Ramon, CA); Hoffman, Myron A. (Davis, CA)

1983-01-01T23:59:59.000Z

296

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

Science Conference Proceedings (OSTI)

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

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

2012-09-01T23:59:59.000Z

297

Heat pipe system  

SciTech Connect

A heat pipe diode device for transferring heat from a heat source component to a heat sink wall is described. It contains a heat pipe body member attached to the best source; the heat source having a wall forming at least a portion of the normal evaporator section of the heat pipe diode; a working fluid within the body member; a cover for the heat pipe diode forming at least a portion of the heat sink wall; the cover forming the normal condenser for the heat pipe diode; a wick connected between the condenser and the evaporator of the heat pipe diode; means for retaining the wick adjacent the heat pipe wall; a wick support plate adjacent to the cover; the wick being attached to the support plate; means for holding the wick in contact with the cover; and means, responsive to excessive temperatures at the heat sink wall, for moving the support plate and a portion of the wick away from the cover to thereby substantially reduce heat flow in the reverse direction through said heat pipe diode device.

Kroebig, H.L.; Riha, F.J. III

1974-12-03T23:59:59.000Z

298

January and July Global Distributions of Atmospheric Heating for 1986, 1987, and 1988  

Science Conference Proceedings (OSTI)

Three-dimensional global distributions of atmospheric heating are estimated for January and July of the 3-year period 1986–88 from the ECMWF/TOGA assimilated datasets. Emphasis is placed on the interseasonal and interannual variability of heating ...

Todd K. Schaack; Donald R. Johnson

1994-08-01T23:59:59.000Z

299

Finite Volume Based Computer Program for Ground Source Heat Pump System  

SciTech Connect

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

Menart, James A. [Wright State University] [Wright State University

2013-02-22T23:59:59.000Z

300

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

SciTech Connect

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

James A Menart, Professor

2013-02-22T23:59:59.000Z

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


301

Electronic thermostat with selectable mode to control heating only, cooling only or both heating and cooling  

Science Conference Proceedings (OSTI)

This patent describes a thermostat for use in a building having means for cooling the building and means for heating the building, the thermostat being connected to the cooling means and the heating means and operative to generate an energizing signal for only one of the heating means or cooling means at a given time, the thermostat comprising: means for measuring the ambient temperature within the building; manual data entry means; means for storing a program of desired heating temperatures over a repetitive time cycle, programmed by the manual data entry means; a clock operative to generate time signals within the repetitive time cycle; means for generating a signal representative of a desired heating temperature and a desired cooling temperature at the present time based upon the signals from the clock in the stored temperature program; means for placing the thermostat in either a first mode where control signals are generated only for the heating means as a function of the difference between the measured temperature within the building and the desired heating temperature signal. Control signals are generated for either the heating means or the cooling means based upon the measured temperature and the respective desired heating and cooling temperature signals.

Levine, M.R.

1987-08-04T23:59:59.000Z

302

Dogs and Time  

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

Question: I travel often and worry how leaving for long periods of time (and boarding my dog) will affect her. I wouldn't think that dogs could understand the concept of...

303

Energy Basics: Absorption Heat Pumps  

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

but by a heat source such as natural gas, propane, solar-heated water, or geothermal-heated water. Because natural gas is the most common heat source for absorption heat...

304

Heat transfer education : Keeping it relevant and vibrant.  

SciTech Connect

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

Khounsary, A. M.

1998-08-14T23:59:59.000Z

305

Latent heat accumulating greenhouse  

Science Conference Proceedings (OSTI)

This invention relates to a latent heat accumulating greenhouse utilizing solar heat. The object of the invention is to provide a greenhouse which is simple in construction, of high efficiency for heat absorbing and capable of much absorbing and accumulating of heat. A heat accumulating chamber partitioned by transparent sheets is provided between the attic and a floor surface facing north in the greenhouse. A blower fan is disposed to confront an opening provided at the lower portion in said heat accumulating chamber. Also, in the heat accumulating chamber, a heat accumulating unit having a large number of light transmitting windows and enclosing a phase transformation heat accumulating material such as CaC1/sub 2/.6H/sub 2/O, Na/sub 2/SO/sub 4/.10H/sub 2/O therein is detachably suspended in a position close to windowpanes at the north side.

Yano, N.; Ito, H.; Makido, I.

1985-04-16T23:59:59.000Z

306

Performance Period Total Fee Paid  

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

Period Period Total Fee Paid 4/29/2012 - 9/30/2012 $418,348 10/1/2012 - 9/30/2013 $0 10/1/2013 - 9/30/2014 $0 10/1/2014 - 9/30/2015 $0 10/1/2015 - 9/30/2016 $0 Cumulative Fee Paid $418,348 Contract Type: Cost Plus Award Fee Contract Period: $116,769,139 November 2011 - September 2016 $475,395 $0 Fee Information Total Estimated Contract Cost $1,141,623 $1,140,948 $1,140,948 $5,039,862 $1,140,948 Maximum Fee $5,039,862 Minimum Fee Fee Available Portage, Inc. DE-DT0002936 EM Contractor Fee Site: MOAB Uranium Mill Tailings - MOAB, UT Contract Name: MOAB Uranium Mill Tailings Remedial Action Contract September 2013 Contractor: Contract Number:

307

Energy Basics: Air-Source Heat Pumps  

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

Systems Air-Source Heat Pumps Ductless Mini-Split Heat Pumps Absorption Heat Pumps Geothermal Heat Pumps Supporting Equipment for Heating & Cooling Systems Water Heating...

308

Heat transfer system  

DOE Patents (OSTI)

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

Not Available

1980-03-07T23:59:59.000Z

309

Heat transfer system  

DOE Patents (OSTI)

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

McGuire, Joseph C. (Richland, WA)

1982-01-01T23:59:59.000Z

310

Laundry heat recovery system  

SciTech Connect

A laundry heat recovery system includes a heat exchanger associated with each dryer in the system, the heat exchanger being positioned within the exhaust system of the dryer. A controller responsive to the water temperature of the heat exchangers and the water storage for the washer selectively circulates the water through a closed loop system whereby the water within the exchangers is preheated by the associated dryers. By venting the exhaust air through the heat exchanger, the air is dehumidified to permit recirculation of the heated air into the dryer.

Alio, P.

1985-04-09T23:59:59.000Z

311

Wound tube heat exchanger  

DOE Patents (OSTI)

What is disclosed is a wound tube heat exchanger in which a plurality of tubes having flattened areas are held contiguous adjacent flattened areas of tubes by a plurality of windings to give a double walled heat exchanger. The plurality of windings serve as a plurality of effective force vectors holding the conduits contiguous heat conducting walls of another conduit and result in highly efficient heat transfer. The resulting heat exchange bundle is economical and can be coiled into the desired shape. Also disclosed are specific embodiments such as the one in which the tubes are expanded against their windings after being coiled to insure highly efficient heat transfer.

Ecker, Amir L. (Duncanville, TX)

1983-01-01T23:59:59.000Z

312

ARM - Measurement - Sensible heat flux  

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

govMeasurementsSensible heat flux govMeasurementsSensible heat flux ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Sensible heat flux The time rate of flow for the energy transferred from a warm or hot surface to whatever is touching it, typically air. Categories Surface Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CO2FLX : Carbon Dioxide Flux Measurement Systems ECOR : Eddy Correlation Flux Measurement System EBBR : Energy Balance Bowen Ratio Station

313

ARM - Measurement - Latent heat flux  

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

govMeasurementsLatent heat flux govMeasurementsLatent heat flux ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Latent heat flux The time rate of flow for the specific enthalpy difference between two phases of a substance at the same temperature, typically water. Categories Surface Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CO2FLX : Carbon Dioxide Flux Measurement Systems ECOR : Eddy Correlation Flux Measurement System EBBR : Energy Balance Bowen Ratio Station

314

Heat Storage Within the Earth System  

Science Conference Proceedings (OSTI)

Observations of the earth's heat budget provide a real-world constraint on the radiative forcing which is simulated in global climate change models. Assessments, such as the IPCC, would more effectively depict changes over time in the climate ...

Roger A. Pielke Sr.

2003-03-01T23:59:59.000Z

315

Optimal joule heating of the subsurface  

DOE Patents (OSTI)

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

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

1994-01-01T23:59:59.000Z

316

Optimal joule heating of the subsurface  

DOE Patents (OSTI)

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

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

1994-07-05T23:59:59.000Z

317

Heat flux solarimeter  

SciTech Connect

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

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

2010-12-15T23:59:59.000Z

318

Heat Exchangers for Solar Water Heating Systems | Department of Energy  

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

Heat Exchangers for Solar Water Heating Systems Heat Exchangers for Solar Water Heating Systems Heat Exchangers for Solar Water Heating Systems May 30, 2012 - 3:40pm Addthis Image of a heat exchanger. | Photo from iStockphoto.com Image of a heat exchanger. | Photo from iStockphoto.com Solar water heating systems use heat exchangers to transfer solar energy absorbed in solar collectors to the liquid or air used to heat water or a space. Heat exchangers can be made of steel, copper, bronze, stainless steel, aluminum, or cast iron. Solar heating systems usually use copper, because it is a good thermal conductor and has greater resistance to corrosion. Types of Heat Exchangers Solar water heating systems use three types of heat exchangers: Liquid-to-liquid A liquid-to-liquid heat exchanger uses a heat-transfer fluid that

319

THE INDUCTION PERIOD IN PHOTOSYNTHESIS  

E-Print Network (OSTI)

When a plant is illuminated, its rate of photosynthesis is at first low and gradually increases until it becomes constant. This induction period was first observed by Osterhout and Haas (1918) for UIva and independently confirmed by Warburg (1920) with Chlorella. It has

L. Smith

1937-01-01T23:59:59.000Z

320

Stability of Underwater Periodic Locomotion  

E-Print Network (OSTI)

Most aquatic vertebrates swim by lateral flapping of their bodies and caudal fins. While much effort has been devoted to understanding the flapping kinematics and its influence on the swimming efficiency, little is known about the stability (or lack of) of periodic swimming. It is believed that stability limits maneuverability and body designs/flapping motions that are adapted for stable swimming are not suitable for high maneuverability and vice versa. In this paper, we consider a simplified model of a planar elliptic body undergoing prescribed periodic heaving and pitching in potential flow. We show that periodic locomotion can be achieved due to the resulting hydrodynamic forces, and its value depends on several parameters including the aspect ratio of the body, the amplitudes and phases of the prescribed flapping. We obtain closed-form solutions for the locomotion and efficiency for small flapping amplitudes, and numerical results for finite flapping amplitudes. We then study the stability of the (finite amplitude flapping) periodic locomotion using Floquet theory. We find that stability depends nonlinearly on all parameters. Interesting trends of switching between stable and unstable motions emerge and evolve as we continuously vary the parameter values. This suggests that, for live organisms that control their flapping motion, maneuverability and stability need not be thought of as disjoint properties, rather the organism may manipulate its motion in favor of one or the other depending on the task at hand.

Fangxu Jing; Eva Kanso

2013-04-18T23:59:59.000Z

Note: This page contains sample records for the topic "time period heating" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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321

Interannual Variability of Indian Ocean Heat Transport  

Science Conference Proceedings (OSTI)

The work in this paper builds upon the relatively well-studied seasonal cycle of the Indian Ocean heat transport by investigating its interannual variability over a 41-yr period (1958–98). An intermediate, two-and-a-half-layer thermodynamically ...

Galina Chirokova; Peter J. Webster

2006-03-01T23:59:59.000Z

322

Prototype solar heating and cooling systems  

DOE Green Energy (OSTI)

A collection of quarterly reports from the AiResearch Manufacturing Company covering the period July 12, 1976, through December 31, 1977, is presented. AiResearch Manufacturing Company is developing eight prototype solar heating and cooling systems. This effort calls for the development, manufacture, test, system installation, maintenance, problem resolution, and performance evaluation. The systems are 3, 25 and 75-ton size units.

Not Available

1978-03-01T23:59:59.000Z

323

Prototype solar heating and hot water systems  

DOE Green Energy (OSTI)

This document is a collection of two quarterly status reports from Colt, Inc., covering the period from October 1, 1977 through June 30, 1978. Colt is developing two prototype solar heating and hot water systems consisting of the following subsystems: collector, storage, control, transport, hot water, and auxiliary energy. The two systems are being installed at Yosemite, California and Pueblo, Colorado.

Not Available

1978-04-01T23:59:59.000Z

324

Passive ice freezing-releasing heat pipe  

DOE Patents (OSTI)

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

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

1982-01-01T23:59:59.000Z

325

Maximum Urban Heat Island Intensity in Seoul  

Science Conference Proceedings (OSTI)

The maximum urban heat island (UHI) intensity in Seoul, Korea, is investigated using data measured at two meteorological observatories (an urban site and a rural site) during the period of 1973–96. The average maximum UHI is weakest in summer and ...

Yeon-Hee Kim; Jong-Jin Baik

2002-06-01T23:59:59.000Z

326

An Assessment of the Southern Ocean Mixed Layer Heat Budget  

Science Conference Proceedings (OSTI)

The mixed layer heat balance in the Southern Ocean is examined by combining remotely sensed measurements and in situ observations from 1 June 2002 to 31 May 2006, coinciding with the period during which Advanced Microwave Scanning Radiometer-...

Shenfu Dong; Sarah T. Gille; Janet Sprintall

2007-09-01T23:59:59.000Z

327

Heat and Freshwater Transport through the Central Labrador Sea  

Science Conference Proceedings (OSTI)

The seasonal and interannual variations in the export of Labrador Sea Water (LSW), and in the heat and freshwater transport through the central Labrador Sea, are examined for two different periods: from 1964 to 1974, using Ocean Weather Station ...

F. Straneo

2006-04-01T23:59:59.000Z

328

Intraseasonal Latent Heat Flux Based on Satellite Observations  

Science Conference Proceedings (OSTI)

Weekly average satellite-based estimates of latent heat flux (LHTFL) are used to characterize spatial patterns and temporal variability in the intraseasonal band (periods shorter than 3 months). As expected, the major portion of intraseasonal ...

Semyon A. Grodsky; Abderrahim Bentamy; James A. Carton; Rachel T. Pinker

2009-09-01T23:59:59.000Z

329

Milliwatt generator heat source. Quarterly technical progress report, April 16, 1976--July 15, 1976  

Science Conference Proceedings (OSTI)

Activities at MRC associated with the Milliwatt Generator Heat Source efforts over the period April 16, 1976, to July 15, 1976, are presented below.

Amos, W.R.

1996-07-01T23:59:59.000Z

330

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

Science Conference Proceedings (OSTI)

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

Not Available

2010-12-01T23:59:59.000Z

331

ICRF heating on helical devices  

SciTech Connect

Ion cyclotron range of frequency (ICRF) heating is currently in use on CHS and W7AS and is a major element of the heating planned for steady state helical devices. In helical devices, the lack of a toroidal current eliminates both disruptions and the need for ICRF current drive, simplifying the design of antenna structures as compared to tokamak applications. However the survivability of plasma facing components and steady state cooling issues are directly applicable to tokamak devices. Results from LHD steady state experiments should be available on a time scale to strongly influence the next generation of steady state tokamak experiments. The helical plasma geometry provides challenges not faced with tokamak ICRF heating, including the potential for enhanced fast ion losses, impurity accumulation, limited access for antenna structures, and open magnetic field lines in the plasma edge. The present results and near term plans provide the basis for steady state ICRF heating of larger helical devices. An approach which includes direct electron, mode conversion, ion minority and ion Bernstein wave heating addresses these issues.

Rasmussen, D.A.; Lyon, J.F.; Hoffman, D.J. [and others

1995-09-01T23:59:59.000Z

332

ICRF heating on helical devices  

SciTech Connect

Ion cyclotron range of frequency (ICRF) heating is currently in use on CHS and W7-AS and is a major element of the heating planned for steady state helical devices. In helical devices, the lack of a toroidal current eliminates both disruptions and the need for ICRF current drive, simplifying the design of antenna structures as compared to tokamak applications. However the survivability of plasma facing components and steady state cooling issues are directly applicable to tokamak devices. Results from LHD steady state experiments should be available on a time scale to strongly influence the next generation of steady state tokamak experiments. The helical plasma geometry provides challenges not faced with tokamak ICRF heating, including the potential for enhanced fast ion losses, impurity accumulation, limited access for antenna structures, and open magnetic field lines in the plasma edge. The present results and near term plans provide the basis for steady state ICRF heating of larger helical devices. An approach which includes direct electron, mode conversion, ion minority and ion Bernstein wave heating addresses these issues.

Rasmussen, D.A.; Lyon, J.F.; Hoffman, D.J.; Murakami, M.; England, A.C.; Wilgen, J.B.; Jaeger, E.F.; Wang, C.; Batchelor, D.B.

1995-09-01T23:59:59.000Z

333

Quantum Operation Time Reversal  

E-Print Network (OSTI)

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 towards 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.

Crooks, Gavin E

2007-01-01T23:59:59.000Z

334

Quantum Operation Time Reversal  

E-Print Network (OSTI)

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 towards 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.

Gavin E. Crooks

2007-06-26T23:59:59.000Z

335

Section D: SPACE HEATING  

U.S. Energy Information Administration (EIA)

Central warm-air furnace with ducts to individual rooms other than a heat pump ..... 03 Steam/Hot water ... REVERSE Heat pump ... Don't have a separate water heater ...

336

Electric Resistance Heating  

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

Electric resistance heat can be supplied by centralized forced-air electric furnaces or by heaters in each room. Electric resistance heating converts nearly all of the energy in the electricity to...

337

Space Heating and Cooling  

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

A wide variety of technologies are available for heating and cooling homes and other buildings. In addition, many heating and cooling systems have certain supporting equipment in common, such as...

338

Heat pipe fabrication  

SciTech Connect

A heat pipe is disclosed which is fabricated with an artery arranged so that the warp and weave of the wire mesh are at about a 45/sup 0/ angle with respect to the axis of the heat pipe.

Leinoff, S.; Edelstein, F.; Combs, W.

1977-01-18T23:59:59.000Z

339

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

Survey: Energy End-Use Consumption Tables Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other...

340

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

E-Print Network (OSTI)

Analysis of. Nonlinear Heat Transfer Problems." Report no.Berkeley, Ca. , APPENDIX A. HEAT TRANSFER BY CONDUCTION ANDMeeting, Technical Session on Heat Transfer in Nuclear Waste

Chan, T.

2010-01-01T23:59:59.000Z

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


341

Consolidated Electric Cooperative- Heat Pump and Water Heating Rebates  

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

342

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

E-Print Network (OSTI)

CLOSED-FORM INTEGRAL SOLUTIONS FOR LINEAR HEAT CONDUCTION.For linear heat conduction in a homogeneous, isotropiclaw of similitude for linear heat conduction was utilized to

Chan, T.

2010-01-01T23:59:59.000Z

343

Solar heat receiver  

DOE Patents (OSTI)

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.

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

1985-01-01T23:59:59.000Z

344

Solar heat receiver  

DOE Patents (OSTI)

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

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

1982-09-29T23:59:59.000Z

345

Abrasion resistant heat pipe  

DOE Patents (OSTI)

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

Ernst, D.M.

1984-10-23T23:59:59.000Z

346

Flue heat reclaimer  

Science Conference Proceedings (OSTI)

A flue heat reclaimer is constructed to be mounted on the exterior of a flue duct of a heater and provide a spiral-shaped heat transfer passage extending around the flue duct. A fan causes air to flow through the heat transfer passage so that the temperature of this air is elevated by reason at its extended heat transfer relationship with the flue duct.

Paolino, R.J.

1983-05-03T23:59:59.000Z

347

Abrasion resistant heat pipe  

DOE Patents (OSTI)

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

Ernst, Donald M. (Leola, PA)

1984-10-23T23:59:59.000Z

348

Stochastic Resonance in a Periodically Modulated Dissipative Nuclear Dynamics  

E-Print Network (OSTI)

A fission decay of highly excited periodically driven compound nuclei is considered in the framework of Langevin approach. We have used residual-time distribution (RTD) as the tool for studying of dynamic features in a presence of periodic perturbation. The structure of RTD essentially depends on the relation between Kramers decay rate and the frequency of the periodic perturbation. In particular, intensity of the first peak in RTD has a sharp maximum at certain nuclear temperature depending on the frequency of the periodic perturbation. This maximum should be considered as first-hand manifestation of stochastic resonance in nuclear dynamics.

V. P. Berezovoj; Yu. L. Bolotin; O. P. Dzyubak; V. V. Yanovsky; A. V. Zhiglo

2001-01-22T23:59:59.000Z

349

HEAT TRANSFER MEANS  

DOE Patents (OSTI)

A heat exchanger is adapted to unifomly cool a spherical surface. Equations for the design of a spherical heat exchanger hav~g tubes with a uniform center-to-center spining are given. The heat exchanger is illustrated in connection with a liquid-fueled reactor.

Fraas, A.P.; Wislicenus, G.F.

1961-07-11T23:59:59.000Z

350

Liquid heat capacity lasers  

DOE Patents (OSTI)

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

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

2007-05-01T23:59:59.000Z

351

Large-Scale Heat and Moisture Budgets over the ASTEX Region  

Science Conference Proceedings (OSTI)

Rawinsonde data collected from the Atlantic Stratocumulus Transition Experiment (ASTEX) were used to investigate the mean and temporal characteristics of large-scale heat and moisture budgets for a 2-week period in June 1992. During this period a ...

Paul E. Ciesielski; Wayne H. Schubert; Richard H. Johnson

1999-09-01T23:59:59.000Z

352

Heat Exchanger Visual Inspection - Partial Tube Blockage Considerations  

Science Conference Proceedings (OSTI)

 Challenges to the thermal performance capability of safety-related open cooling water system heat exchangers were a major reason the Nuclear Regulatory Commission (NRC) issued Generic Letter 89-13, “Service Water System Problems Affecting Safety Related Equipment.” GL 89-13 required licensees to commit to various actions to ensure that thermal performance requirements were met for heat exchangers supporting the ultimate heat sink (UHS) function. These actions may include periodic ...

2012-09-05T23:59:59.000Z

353

Heat Recovery Steam Generator (HRSG) Chemical Cleaning Guidelines Case Studies  

Science Conference Proceedings (OSTI)

A considerable number of combined cycle units with heat recovery steam generators (HRSGs) were installed over the past two decades worldwide, and the design complexity and operating pressures of these units increased significantly during this period. One of the goals of EPRI's Heat Recovery Steam Generator (HRSG) Dependability Program 88 is to minimize availability losses associated with HRSG tube failures. To support its members operating combined cycle units, EPRI published Heat Recovery Steam Generato...

2006-11-13T23:59:59.000Z

354

Maslov indices for periodic orbits  

E-Print Network (OSTI)

It is shown that there is a generalization of the Conley-Zehnder index for periodic trajectories of a classical Hamiltonian system $(Q, \\omega, H)$ from the case $Q = T^*R^n$ to arbitrary symplectic manifolds. As it turns out, it is precisely this index which appears as a Maslov phase in the trace formulas by Gutzwiller and Duistermaat-Guillemin. Contribution presented at the XIX ICGTMP Salamanca June 92.

Meinrenken, E

1992-01-01T23:59:59.000Z

355

New Heat Flow Models in Fractured Geothermal Reservoirs - Final Report  

DOE Green Energy (OSTI)

This study developed new analytical models for predicting the temperature distribution within a geothermal reservoir following reinjection of water having a temperature different from that of the reservoir. The study consisted of two parts: developing new analytical models for the heat conduction rate into multi-dimensional, parallelepiped matrix blocks and developing new analytical models for the advance of the thermal front through the geothermal reservoir. In the first part of the study, a number of semi-empirical models for the multi-dimensional heat conduction were developed to overcome the limitations to the exact solutions. The exact solution based on a similarity solution to the heat diffusion equation is the best model for the early-time period, but fails when thermal conduction fronts from opposing sides of the matrix block merge. The exact solution based on an infinite series solution was found not to be useful because it required tens of thousands of terms to be include d for accuracy. The best overall model for the entire conduction time was a semi-empirical model based on an exponential conduction rate. In the second part of the study, the early-time period exact solution based on similarity methods and the semi-empirical exponential model were used to develop new analytical models for the location of the thermal front within the reservoir during injection. These equations were based on an energy balance on the water in the fractured network. These convective models allowed for both dual and triple porosity reservoirs, i.e., one or two independent matrix domains. A method for incorporating measured fracture spacing distributions into these convective models was developed. It was found that there were only minor differences in the predicted areal extent of the heated zone between the dual and triple porosity models. Because of its simplicity, the dual porosity model is recommended. These new models can be used for preliminary reservoir studies. Although they are not as accurate as numerical simulators, they are simple, easy and inexpensive to use. These new models can be used to get general information about reservoir behavior before committing to the considerable greater expense of numerical simulation.

Reis, John

2001-03-31T23:59:59.000Z

356

Propane: A Mid-heating Season Assessment  

Gasoline and Diesel Fuel Update (EIA)

9, 2001 9, 2001 Propane - A Mid-Heating Season Assessment by David Hinton and Alice Lippert, Petroleum Division, Office of Oil and Gas, Energy Information Administration In early October 2000, the Energy Information Administration (EIA) forecast that heating fuel markets would be expected to start the season with much higher prices and lower inventories than in recent years. While this assessment was true for both the heating oil and natural gas markets, propane markets actually began the season with adequate supplies but with high prices. Since EIA's forecast, propane inventories have plunged nearly 20 million barrels from their peak during the first half of the 2000-01 heating season while propane prices have continued to soar even higher than expected during this same period. This report will analyze some

357

A corrosive resistant heat exchanger  

DOE Patents (OSTI)

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

Richlen, S.L.

1987-08-10T23:59:59.000Z

358

Energy Basics: Geothermal Heat Pumps  

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

EERE: Energy Basics Geothermal Heat Pumps Geothermal heat pumps use the constant temperature of the earth as an exchange medium for heat. Although many parts of the country...

359

Absorption heat pump system  

DOE Patents (OSTI)

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

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

1984-01-01T23:59:59.000Z

360

Applied heat transfer  

Science Conference Proceedings (OSTI)

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)

Ganapathy, V.

1982-01-01T23:59:59.000Z

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


361

Plasma heat pump and heat engine  

Science Conference Proceedings (OSTI)

A model system where cold charged particles are locally confined in a volume V{sub P} within a warm plasma of volume V (V{sub P}kilowatts is possible with the present day technology. Second, we discuss the feasibility of constructing an electrostatic heat engine which converts plasma heat into mechanical work via plasma electric fields. Effects of P{sub E} are shown to be observable in colloidal solutions.

Avinash, K. [Centre for Space Plasma and Aeronomic Research, University of Alabama, Huntsville, Alabama 35899 (United States) and Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

2010-08-15T23:59:59.000Z

362

PARAMETER ESTIMATION BASED MODELS OF WATER SOURCE HEAT PUMPS  

E-Print Network (OSTI)

a two-year research program in heat transfer and viscoelastic fluid flows, after working for some time Sciences), Fluid Mechanics, Heat Transfer and related (815) 753-9975 Page 1 of 2WSEAS Conferences: www on HEAT and MASS TRANSFER (HMT'09) [Download a Map of the area (16 Kbytes)] [Download a Map of the city

363

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

E-Print Network (OSTI)

law of similitude for linear heat conduction was utilized tothe analogy between heat conduction and fluid flow in por­the effects of heat conduction through the vermiculite heat

Chan, T.

2010-01-01T23:59:59.000Z

364

Heat pump apparatus  

DOE Patents (OSTI)

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

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

1983-01-01T23:59:59.000Z

365

Heating Degree Days, by State (Weighted by Population, per 2000 Census) |  

Open Energy Info (EERE)

66 66 Varnish cache server Browse Upload data GDR 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2142278566 Varnish cache server Heating Degree Days, by State (Weighted by Population, per 2000 Census) Dataset Summary Description The National Oceanic and Atmospheric Administration's (NOAA) National Environmental Satellite, Data, and Information Services (NESDIS), in conjunction with the National Climatic Data Center (NCDC) publish monthly and annual climate data by state for the U.S., including, heating degree days (total number of days per month and per year). The average values for each state are weighted by population, using 2000 Census data. The base temperature for this dataset is 65 degrees F. Included here are monthly and annual values averaged over several periods of time: 1931-2000, 1931-60, 1941-70, 1951-80, 1961-90, 1971-2000 (standard deviation is also provided). Detailed monthly climatic information (including heating degree days) is available for the time period between 1895 and 2011, from NOAA (http://www7.ncdc.noaa.gov/CDO/CDODivisionalSelect.jsp#).

366

Active microchannel heat exchanger  

DOE Patents (OSTI)

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

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

2001-01-01T23:59:59.000Z

367

Switchable heat pipe assembly  

SciTech Connect

The heat pipe assembly is formed into an H-shape or a Y-shape. The H-shaped configuration comprises two heat pipes, each having condenser and evaporator sections with wicking therein coupled by a tube with wick at their evaporator sections. The Y-shaped configuration utilizes a common evaporator section in place of the two evaporator sections of the H-shaped configuration. In both configurations, the connection between the vapor spaces of the two heat pipes equalizes vapor pressure within the heat pipes. Although both heat pipes have wicks, they have sufficient fluid only to saturate a single pipe. If heat is applied to the condenser section of one of the pipes, this heat pipe becomes inoperative since all the fluid is transferred to the second pipe which can operate with a lower thermal load.

Sun, T.H.; Basiulis, A.

1977-02-15T23:59:59.000Z

368

The Effects of Heat Treatment and Microstructure Variations on Disk ...  

Science Conference Proceedings (OSTI)

flow and time dependent response near the crack tip, rather than ... Simple bar charts comparing mechanical properties of selected end point heat treatments are ...

369

Near Infrared Heating and Sintering; A Versatile Tool to Enable ...  

Science Conference Proceedings (OSTI)

A single heating technique (near infrared (NIR)) can bring down oven residence times to seconds. Five examples in relation to HOPV production are: (1) TiO2 ...

370

Influence of Heat Treatment on Corrosion and Wear Resistances of ...  

Science Conference Proceedings (OSTI)

Both the increasing of the heating up time and the prolonging of the temperature ... with FRP Facesheets and Nanoclay-wood Flour Modified Polyurethane Foam.

371

Estimating the Payback Period of Additional Insulation | Department of  

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

the Payback Period of Additional Insulation the Payback Period of Additional Insulation Estimating the Payback Period of Additional Insulation June 24, 2012 - 1:17pm Addthis Adding insulation in the attic of an existing home often results in a favorable payback. | Photo courtesy of Lieko Earle, NREL PIX 19612. Adding insulation in the attic of an existing home often results in a favorable payback. | Photo courtesy of Lieko Earle, NREL PIX 19612. What does this mean for me? Even if you hire a contractor to do the work, adding insulation to your home will likely have an attractive payback. If you can gather the information and plug it into an equation, you can determine the payback of adding insulation to your home. Use the equation below to estimate the cost effectiveness of adding insulation in terms of the "years to payback" for savings in heating costs.

372

Estimating the Payback Period of Additional Insulation | Department of  

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

Estimating the Payback Period of Additional Insulation Estimating the Payback Period of Additional Insulation Estimating the Payback Period of Additional Insulation June 24, 2012 - 1:17pm Addthis Adding insulation in the attic of an existing home often results in a favorable payback. | Photo courtesy of Lieko Earle, NREL PIX 19612. Adding insulation in the attic of an existing home often results in a favorable payback. | Photo courtesy of Lieko Earle, NREL PIX 19612. What does this mean for me? Even if you hire a contractor to do the work, adding insulation to your home will likely have an attractive payback. If you can gather the information and plug it into an equation, you can determine the payback of adding insulation to your home. Use the equation below to estimate the cost effectiveness of adding insulation in terms of the "years to payback" for savings in heating costs.

373

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

E-Print Network (OSTI)

standing of the heat transfer processes associated withto investigate the heat transfer and related processes in an

Chan, T.

2010-01-01T23:59:59.000Z

374

Carbon Material Based Heat Exchanger for Waste Heat Recovery ...  

Industrial processing plants Nuclear power Solar power ... Carbon Material Based Heat Exchanger for Waste Heat Recovery from Engine Exhaust Contact:

375

A model for improvement of water heating heat exchanger designs for residential heat pump water heaters.  

E-Print Network (OSTI)

??Heat pump water heaters are a promising technology to reduce energy use and greenhouse gas emissions. A key component is the water heating heat exchanger.… (more)

Weerawoot, Arunwattana

2010-01-01T23:59:59.000Z

376

Method and apparatus for determining vertical heat flux of geothermal field  

DOE Patents (OSTI)

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

Poppendiek, Heinz F. (LaJolla, CA)

1982-01-01T23:59:59.000Z

377

Unsteady flow and heat transfer in a channel with a built-in tandem of rectangular cylinders  

Science Conference Proceedings (OSTI)

The incompressible unsteady flow past a channel with a pair of cylinders of rectangular cross section, placed in tandem normal to the flow, is investigated by numerical simulation. The objective is to evaluate the effect of cylinder separation distance, S/H, on the flow behavior and heat transfer on the channel walls, over a range of Reynolds numbers. Above a critical Reynolds number, these flows bifurcate to a time-periodic self-sustained oscillatory state. The results reveal for S/H = 2.0 three distinct flow patterns: steady flow (Re = 200), time-periodic oscillatory state (400 {le} Re {le} 800), and quasi-periodic oscillatory flow (Re = 1,000). For S/H 600.

Valencia, A. [Universidad de Chile, Santiago (Chile). Dept. de Ingenieria Mecanica

1996-05-10T23:59:59.000Z

378

Encouraging Combined Heat and Power in California Buildings  

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

Encouraging Combined Heat and Power in California Buildings Encouraging Combined Heat and Power in California Buildings Title Encouraging Combined Heat and Power in California Buildings Publication Type Report LBNL Report Number LBNL-6267E Year of Publication 2013 Authors Stadler, Michael, Markus Groissböck, Gonçalo Cardoso, Andreas Müller, and Judy Lai Abstract Governor Brown's research priorities include an additional 6.5 GW of combined heat and power (CHP) by 2030. As of 2009, roughly 0.25 GW of small natural gas and biogas fired CHP is documented by the Self-Generation Incentive Program (SGIP) database. The SGIP is set to expire, and the anticipated grid de-carbonization based on the development of 20 GW of renewable energy will influence the CHP adoption. Thus, an integrated optimization approach for this analysis was chosen that allows optimizing the adoption of distributed energy resources (DER) such as photovoltaics (PV), CHP, storage technologies, etc. in the California commercial sector from the building owners' perspective. To solve this DER adoption problem the Distributed Energy Resources Customer Adoption Model (DER-CAM), developed by the Lawrence Berkeley National Laboratory and used extensively to address the problem of optimally investing and scheduling DER under multiple settings, has been used. The application of CHP at large industrial sites is well known, and much of its potential is already being realized. Conversely, commercial sector CHP, especially those above 50 to 100 kW peak electricity load, is widely overlooked. In order to analyze the role of DER in CO2 reduction, 147 representative sites in different climate zones were selected from the California Commercial End Use Survey (CEUS). About 8000 individual optimization runs, with different assumptions for the electric tariffs, natural gas costs, marginal grid CO2 emissions, and nitrogen oxide treatment costs, SGIP, fuel cell lifetime, fuel cell efficiency, PV installation costs, and payback periods for investments have been performed. The most optimistic CHP potential contribution in this sector in 2020 will be 2.7 GW. However, this result requires a SGIP in 2020, 46% average electric efficiency for fuel cells, a payback period for investments of 10 years, and a CO2 focused approach of the building owners. In 2030 it will be only 2.5 GW due to the anticipated grid de-carbonization. The 2030 result requires a 60% electric efficiency and 20 year life time for fuel cells, a payback period of 10 years, and a CO2 minimization strategy of building owners. Finally, the possible CHP potential in 2030 shows a significant variance between 0.2 GW and 2.5 GW, demonstrating the complex interactions between technologies, policies, and customer objectives.

379

PreHeat: controlling home heating using occupancy prediction  

Science Conference Proceedings (OSTI)

Home heating is a major factor in worldwide energy use. Our system, PreHeat, aims to more efficiently heat homes by using occupancy sensing and occupancy prediction to automatically control home heating. We deployed PreHeat in five homes, three in the ... Keywords: energy, environment, home heating, prediction, sensing

James Scott; A.J. Bernheim Brush; John Krumm; Brian Meyers; Michael Hazas; Stephen Hodges; Nicolas Villar

2011-09-01T23:59:59.000Z

380

Energy 101: Geothermal Heat Pumps | Department of Energy  

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

Energy 101: Geothermal Heat Pumps Energy 101: Geothermal Heat Pumps Energy 101: Geothermal Heat Pumps January 4, 2011 - 12:15pm Addthis 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. John Schueler John Schueler Former New Media Specialist, Office of Public Affairs Quick Facts Heat pump systems can lower energy bills by up to 70% over traditional types of heating systems. During this time of year, many homeowners are searching for ways to reduce steep heating costs. One of the options they should consider during the

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


381

Energy 101: Geothermal Heat Pumps | Department of Energy  

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

Energy 101: Geothermal Heat Pumps Energy 101: Geothermal Heat Pumps Energy 101: Geothermal Heat Pumps January 4, 2011 - 12:15pm Addthis 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. John Schueler John Schueler Former New Media Specialist, Office of Public Affairs Quick Facts Heat pump systems can lower energy bills by up to 70% over traditional types of heating systems. During this time of year, many homeowners are searching for ways to reduce steep heating costs. One of the options they should consider during the

382

Optimal Design for a Hybrid Ground-Source Heat Pump  

E-Print Network (OSTI)

Although the advantages of ground-source heat pumps over their conventional alternatives make these systems a very attractive choice for air conditioning, not only for residential buildings but increasingly also for institutional and commercial buildings, a significant barrier to wider application of this technology is a high first cost. When used in cooling-dominated buildings, ground-source heat pumps that utilize vertical, closed-loop ground heat exchangers can experience performance degradation as the entering fluid temperature to the heat pump increases over time due to heat buildup in the borefield. In these cases, it is possible to displace a large portion of the system cost by installing a supplemental heat rejecter to balance the annual heat extraction from the ground. The paper presented has shown that the heat rejection of the GLHEs and the system energy consumption are approached to discuss the ground heat balance with different design procedures and control strategies though the system simulation.

Yu, Z.; Yuan, X.; Wang, B.

2006-01-01T23:59:59.000Z

383

Energy Basics: Heat Pump Systems  

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

of air-source heat pumps. Absorption Heat Pump Uses heat as its energy source. Geothermal Heat Pumps Use the constant temperature of the earth as the exchange medium instead...

384

Time Trends in Dutch Children's Mental Health.  

E-Print Network (OSTI)

??This study investigated time trends in Dutch children's and adolescent's mental health problems by comparing population samples from different time periods. From 1983 to 2003,… (more)

Tick, N.T.

2007-01-01T23:59:59.000Z

385

Heat pump system  

DOE Patents (OSTI)

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

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

1983-01-01T23:59:59.000Z

386

Heat pump system  

DOE Patents (OSTI)

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

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

1977-01-01T23:59:59.000Z

387

Heat Management Strategy Trade Study  

SciTech Connect

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

Nick Soelberg; Steve Priebe; Dirk Gombert; Ted Bauer

2009-09-01T23:59:59.000Z

388

Water-heating dehumidifier  

DOE Patents (OSTI)

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

Tomlinson, John J. (Knoxville, TN)

2006-04-18T23:59:59.000Z

389

Case for utility involvement in solar-domestic water heating  

SciTech Connect

Credibility of system performance over an extended period of time is still a major concern for prospective buyers of solar-collector systems. Although Congress has enacted solar legislation with the intention of assisting homeowners in the adoption of solar energy, it apparently did not consider which organizational entities could best address the concerns of the consumer and accelerate the adoption of solar energy for domestic hot water heating. This article points out that legislation which does not encourage full participation by utilities in the marketing of solar energy has produced very low adoption rates compared to the size of the solar market potential. It also describes some of the empirical results of one utility company's efforts with a large-scale solar demonstration program, and presents some findings for the investor-owned utility industry to consider before Congress takes additional legislative action in this area. 11 references, 2 figures, 2 tables.

Smackey, B.M.

1982-04-01T23:59:59.000Z

390

Heating remote rooms in passive solar buildings  

DOE Green Energy (OSTI)

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

Balcomb, J.D.

1981-01-01T23:59:59.000Z

391

Hydride heat pump  

DOE Patents (OSTI)

Method and apparatus for the use of hydrides to exhaust heat from one temperature source and deliver the thermal energy extracted for use at a higher temperature, thereby acting as a heat pump. For this purpose there are employed a pair of hydridable metal compounds having different characteristics working together in a closed pressure system employing a high temperature source to upgrade the heat supplied from a low temperature source.

Cottingham, James G. (Center Moriches, NY)

1977-01-01T23:59:59.000Z

392

Heat storage duration  

DOE Green Energy (OSTI)

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

Balcomb, J.D.

1981-01-01T23:59:59.000Z

393

Computing with almost periodic functions  

E-Print Network (OSTI)

The paper develops a method for discrete computational Fourier analysis of functions defined on quasicrystals and other almost periodic sets. A key point is to build the analysis around the emerging theory of quasicrystals and diffraction in the setting on local hulls and dynamical systems. Numerically computed approximations arising in this way are built out of the Fourier module of the quasicrystal in question, and approximate their target functions uniformly on the entire infinite space. The methods are entirely group theoretical, being based on finite groups and their duals, and they are practical and computable. Examples of functions based on the standard Fibonacci quasicrystal serve to illustrate the method (which is applicable to all quasicrystals modeled on the cut and project formalism).

R. V. Moody; M. Nesterenko; J. Patera

2008-08-13T23:59:59.000Z

394

Experimental testing and analytical analysis of a plastic panel heat exchanger for greenhouse heating  

SciTech Connect

The performance of a plastic panel-type heat exchanger, suitable for greenhouse heating using low-grade (25 to 60/sup 0/C water) power plant reject heat, was investigated theoretically and experimentally. The theoretical analysis showed that a plastic panel heat exchanger would have an overall heat transfer coefficient, U/sub 0/, of about 18 w/m/sup 2/-/sup 0/C compared to about 12 w/m/sup 2/-/sup 0/C for a fin-tube heat exchanger, under typical greenhouse conditions. Furthermore the plastic heat exchanger would require less fan power due to reduced air pressure losses. The experimental data revealed a similar functional relationship for U/sub 0/ and air flow when compared with the theoretical calculations, however the experimental values of U/sub 0/ were consistently larger by 20 to 30%. It was concluded that a properly designed plastic heat exchanger can compete with metal fin tube type exchangers on a performance basis, but the plastic heat exchangers are 3 to 4 times larger by volume. However, because of the lower cost of plastic, a substantial cost reduction is expected. It appears that further study, examining heat exchanger lifetime, performance and costs, is warranted.

Olszewski, M.; Thomas, J.F.

1980-02-01T23:59:59.000Z

395

Waste Heat Management Options: Industrial Process Heating Systems  

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

Heat Management Options Heat Management Options Industrial Process Heating Systems By Dr. Arvind C. Thekdi E-mail: athekdi@e3minc.com E3M, Inc. August 20, 2009 2 Source of Waste Heat in Industries * Steam Generation * Fluid Heating * Calcining * Drying * Heat Treating * Metal Heating * Metal and Non-metal Melting * Smelting, agglomeration etc. * Curing and Forming * Other Heating Waste heat is everywhere! Arvind Thekdi, E3M Inc Arvind Thekdi, E3M Inc 3 Waste Heat Sources from Process Heating Equipment * Hot gases - combustion products - Temperature from 300 deg. F. to 3000 deg.F. * Radiation-Convection heat loss - From temperature source of 500 deg. F. to 2500 deg. F. * Sensible-latent heat in heated product - From temperature 400 deg. F. to 2200 deg. F. * Cooling water or other liquids - Temperature from 100 deg. F. to 180 deg. F.

396

Heat rejection system  

DOE Patents (OSTI)

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

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

1980-01-01T23:59:59.000Z

397

Section D: SPACE HEATING  

U.S. Energy Information Administration (EIA)

2005 Residential Energy Consumption Survey Form EIA-457A (2005)--Household Questionnaire OMB No.: 1905-0092, Expiring May 31, 2008 33 Section D: SPACE HEATING

398

Heat and mass exchanger  

Science Conference Proceedings (OSTI)

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

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

2011-06-28T23:59:59.000Z

399

Heat pump arrangement  

SciTech Connect

The invention concerns a heat pump arrangement for heating of houses. The arrangement comprises a compressor, a condensor and a vaporizer, which is a part of an icing machine. The vaporizer is designed as a heat exchanger and is connected to a circulation system comprising an accumulator, to which the ice slush from the icing machine is delivered. Water from the accumulator is delivered to the icing machine. The water in the accumulator can be heated E.G. By means of a solar energy collector, the outdoor air etc. Surface water or waste water from the household can be delivered to the accumulator and replace the ice slush therein.

Abrahamsson, T.; Hansson, K.

1981-03-03T23:59:59.000Z

400

Convection Heat Transfer  

Science Conference Proceedings (OSTI)

...Heat-Transfer Equations, Fundamentals of Modeling for Metals Processing, Vol 22A, ASM Handbook, ASM International, 2009, p 625â??658...

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


401

HEATS: Thermal Energy Storage  

SciTech Connect

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

None

2012-01-01T23:59:59.000Z

402

Heat transfer dynamics  

Science Conference Proceedings (OSTI)

As heat transfer technology increases in complexity, it becomes more difficult for those without thermal dynamics engineering training to choose between competitive heat transfer systems offered to meet their drying requirements. A step back to the basics of heat transfer can help professional managers and papermakers make informed decisions on alternative equipment and methods. The primary forms of heat and mass transfer are reviewed with emphasis on the basics, so a practical understanding of each is gained. Finally, the principles and benefits of generating infrared energy by combusting a gaseous hydrocarbon fuel are explained.

Smith, T.M. (Marsden, Inc., Pennsauken, NJ (United States))

1994-08-01T23:59:59.000Z

403

Oceanic Heat Flux Calculation  

Science Conference Proceedings (OSTI)

The authors review the procedure for the direct calculation of oceanic heat flux from hydrographic measurements and set out the full “recipe” that is required.

Sheldon Bacon; Nick Fofonoff

1996-12-01T23:59:59.000Z

404

Passive solar space heating  

DOE Green Energy (OSTI)

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

Balcomb, J.D.

1980-01-01T23:59:59.000Z

405

Energy Basics: Water Heating  

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

about: Conventional Storage Water Heaters Demand (Tankless or Instantaneous) Water Heaters Heat Pump Water Heaters Solar Water Heaters Tankless Coil and Indirect Water Heaters...

406

Controlling the Heat Transfer  

Science Conference Proceedings (OSTI)

Through experimental validation that air conduction is shown to be typically the dominant thermal transport mechanism in the contact region, the heat conduction

407

Heating Fuel Comparision Calculator  

U.S. Energy Information Administration (EIA)

Wood, Pellet, Corn (kernel), and Coal Heaters Heating Fuel Comparison Calculator Instructions and Guidance Residential Fuel/Energy Price Links Spot Prices, Daily

408

Negative heat capacities and first order phase transitions in nuclei  

E-Print Network (OSTI)

Anomalous negative heat capacities have been claimed as indicators of first order phase transitions in finite systems in general, and fornuclear systems in particular. A thermodynamic approach allowing for all Q value terms is used to evaluate heat capacities in finitevan der Waals fluids and finite lattice systems in the coexistence region. Fictitious large effects and negative heat capacities are observed in lattice systems when periodic boundary conditions are introduced. Small anomalous effects are predicted for small drops and for finite lattice systems. A straightforward application of the analysis to nuclei shows that negative heat capacities cannot be observed for A>60.

L. G. Moretto; J. B. Elliott; L. Phair; G. J. Wozniak

2002-08-13T23:59:59.000Z

409

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

Science Conference Proceedings (OSTI)

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

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

2011-01-01T23:59:59.000Z

410

Promotion of efficient heat pumps for heating (ProHeatPump)  

E-Print Network (OSTI)

and towns have (some) district heating, and DH currently supplies 1% of heating for buildings in Norway.2 to district heating if there is a supply. According to HP industry representatives, howeverProject Promotion of efficient heat pumps for heating (ProHeatPump) EIE/06/072 / S12

411

Tidal Heating of Extra-Solar Planets  

E-Print Network (OSTI)

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

Brian Jackson; Richard Greenberg; Rory Barnes

2008-02-29T23:59:59.000Z

412

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

DOE Patents (OSTI)

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.

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

1998-11-24T23:59:59.000Z

413

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

DOE Patents (OSTI)

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.

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

414

Atmospheric Forcing of the Winter Air–Sea Heat Fluxes over the Northern Red Sea  

Science Conference Proceedings (OSTI)

The influence of the atmospheric circulation on the winter air–sea heat fluxes over the northern Red Sea is investigated during the period 1985–2011. The analysis based on daily heat flux values reveals that most of the net surface heat exchange ...

Vassilis P. Papadopoulos; Yasser Abualnaja; Simon A. Josey; Amy Bower; Dionysios E. Raitsos; Harilaos Kontoyiannis; Ibrahim Hoteit

2013-03-01T23:59:59.000Z

415

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

SciTech Connect

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

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

1992-07-01T23:59:59.000Z

416

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

SciTech Connect

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

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

1992-07-01T23:59:59.000Z

417

Heat Pipe Integrated Microsystems  

SciTech Connect

The trend in commercial electronics packaging to deliver ever smaller component packaging has enabled the development of new highly integrated modules meeting the demands of the next generation nano satellites. At under ten kilograms, these nano satellites will require both a greater density electronics and a melding of satellite structure and function. Better techniques must be developed to remove the subsequent heat generated by the active components required to-meet future computing requirements. Integration of commercially available electronics must be achieved without the increased costs normally associated with current generation multi chip modules. In this paper we present a method of component integration that uses silicon heat pipe technology and advanced flexible laminate circuit board technology to achieve thermal control and satellite structure. The' electronics/heat pipe stack then becomes an integral component of the spacecraft structure. Thermal management on satellites has always been a problem. The shrinking size of electronics and voltage requirements and the accompanying reduction in power dissipation has helped the situation somewhat. Nevertheless, the demands for increased onboard processing power have resulted in an ever increasing power density within the satellite body. With the introduction of nano satellites, small satellites under ten kilograms and under 1000 cubic inches, the area available on which to place hot components for proper heat dissipation has dwindled dramatically. The resulting satellite has become nearly a solid mass of electronics with nowhere to dissipate heat to space. The silicon heat pipe is attached to an aluminum frame using a thermally conductive epoxy or solder preform. The frame serves three purposes. First, the aluminum frame provides a heat conduction path from the edge of the heat pipe to radiators on the surface of the satellite. Secondly, it serves as an attachment point for extended structures attached to the satellite such as solar panels, radiators, antenna and.telescopes (for communications or sensors). Finally, the packages make thermal contact to the surface of the silicon heat pipe through soft thermal pads. Electronic components can be placed on both sides of the flexible circuit interconnect. Silicon heat pipes have a number of advantages over heat pipe constructed from other materials. Silicon heat pipes offer the ability to put the heat pipe structure beneath the active components of a processed silicon wafer. This would be one way of efficiently cooling the heat generated by wafer scale integrated systems. Using this technique, all the functions of a satellite could be reduced to a few silicon wafers. The integration of the heat pipe and the electronics would further reduce the size and weight of the satellite.

Gass, K.; Robertson, P.J.; Shul, R.; Tigges, C.

1999-03-30T23:59:59.000Z

418

Time lines  

Science Conference Proceedings (OSTI)

... The reactor was shut down on April 3, 2011 and restarted to low power on February 8, 2012. During the post-outage period, which runs until ...

419

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ........................... 1,870 1,276 322 138 133 43.0 29.4 7.4 3.2 3.1 Building Floorspace (Square Feet) 1,001 to 5,000 ........................... 243 151 34 40 18 78.7 48.9 11.1 13.0 5.7 5,001 to 10,000 .......................... 202 139 31 29 Q 54.8 37.6 8.5 7.9 Q 10,001 to 25,000 ........................ 300 240 31 21 7 42.5 34.1 4.4 3.0 1.1 25,001 to 50,000 ........................ 250 182 40 11 Q 41.5 30.2 6.6 1.9 Q 50,001 to 100,000 ...................... 236 169 41 8 19 35.4 25.2 6.2 1.2 2.8 100,001 to 200,000 .................... 241 165 54 7 16 36.3 24.8 8.1 1.0 2.4 200,001 to 500,000 .................... 199 130 42 11 16 35.0 22.8 7.5 1.9 2.8 Over 500,000 ............................. 198

420

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings ............................. 2,037 1,378 338 159 163 42.0 28.4 7.0 3.3 3.4 Building Floorspace (Square Feet) 1,001 to 5,000 ........................... 249 156 35 41 18 78.6 49.1 11.0 12.9 5.6 5,001 to 10,000 .......................... 218 147 32 31 7 54.8 37.1 8.1 7.9 1.7 10,001 to 25,000 ........................ 343 265 34 25 18 43.8 33.9 4.4 3.2 2.3 25,001 to 50,000 ........................ 270 196 41 13 Q 40.9 29.7 6.3 2.0 2.9 50,001 to 100,000 ...................... 269 186 45 13 24 35.8 24.8 6.0 1.8 3.2 100,001 to 200,000 .................... 267 182 56 10 19 35.4 24.1 7.4 1.3 2.6 200,001 to 500,000 .................... 204 134 43 11 17 34.7 22.7 7.3 1.8 2.9 Over 500,000 .............................

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


421

Integrated heat pipe-thermal storage system performance evaluation  

SciTech Connect

Performance verification tests of an integrated heat pipe-thermal energy storage system have been conducted. This system is being developed as a part of an Organic Rankine Cycle-Solar Dynamic Power System (ORC-SDPS) receiver for future space stations. The integrated system consists of potassium heat pipe elements that incorporate thermal energy storage (TES) canisters within the vapor space along with an organic fluid (toluene) heater tube used as the condenser region of the heat pipe. During the insolation period of the earth orbit, solar energy is delivered to the surface of the heat pipe elements of the ORC-SDPS receiver and is internally transferred by the potassium vapor for use and storage. Part of the thermal energy is delivered to the heater tube and the balance is stored in the TES units. During the eclipse period of the orbit, the stored energy in the TES units is transferred by the potassium vapor to the toluene heater tube. A developmental heat pipe element was fabricated that employs axial arteries and a distribution wick connecting the wicked TES units and the heater to the solar insolation surface of the heat pipe. Tests were conducted to verify the heat pipe operation and to evaluate the heat pipe/TES units/heater tube operation by interfacing the heater unit to a heat exchanger.

Keddy, E.; Sena, J.T.; Merrigan, M.

1987-01-01T23:59:59.000Z

422

Stochastic resonance in a periodically modulated dissipative nuclear dynamics  

SciTech Connect

A fission decay of highly excited periodically driven compound nuclei is considered in the framework of Langevin approach. The authors have used residual-time distribution (RTD) as the tool for studying of dynamic features in a presence of periodic perturbation. The structure of RTD essentially depends on the relation between Kramers decay rate and the frequency {omega} of the periodic perturbation. In particular, intensity of the first peak in RTD has a sharp maximum at certain nuclear temperature depending on {omega}. This maximum should be considered as first-hand manifestation of stochastic resonance in nuclear dynamics.

Berezovoy, V.P. [and others

2001-02-01T23:59:59.000Z

423

Stochastic Resonance in a Periodically Modulated Dissipative Nuclear Dynamics  

E-Print Network (OSTI)

A fission decay of highly excited periodically driven compound nuclei is considered in the framework of Langevin approach. We have used residual-time distribution (RTD) as the tool for studying of dynamic features in a presence of periodic perturbation. The structure of RTD essentially depends on the relation between Kramers decay rate and the frequency ? of the periodic perturbation. In particular, intensity of the first peak in RTD has a sharp maximum at certain nuclear temperature depending on ?. This maximum should be considered as first-hand manifestation of stochastic resonance in nuclear dynamics. 1

unknown authors

2008-01-01T23:59:59.000Z

424

Class B monitoring program handbook for southeastern sites with data based on INIT2 software (applicable to heating season)  

DOE Green Energy (OSTI)

This document provides reference information on eight residences located in the southern part of the US which are being monitored under the Class B Passive Solar Monitoring Program. This handbook provides reference information on the sites and basic test conditions for the 1982-1983 winter heating season using software which is identified as INIT2. The manual is intended for use in data analysis work but is limited to this period of time because of basic differences in the control software and the related instrumentation system. This document is separated into individual sections for each site. The following information is provided for each site: (a) Site summary providing information on the structure, the passive solar features, the auxiliary heating system, and other related data; (b) Floor layouts with the sensor locations, etc.; (c) The One Time Value Log which records the results of field tests and calculations to determine the thermal characteristics, air infiltration rate, and other reference data; (d) The Analog/Digital Channel Log which provides calibration data; (e) The Status Channel Log which defines various event sensors; and (f) Program listings as used during the specified time periods during the heating season. Appendix A provides a summary of photographs which have been provided separately as part of the site documentation.

Gustashaw, D. H.

1983-07-01T23:59:59.000Z

425

Waste Heat Recovery from Industrial Process Heating Equipment -  

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

Waste Heat Recovery from Industrial Process Heating Equipment - Waste Heat Recovery from Industrial Process Heating Equipment - Cross-cutting Research and Development Priorities Speaker(s): Sachin Nimbalkar Date: January 17, 2013 - 11:00am Location: 90-2063 Seminar Host/Point of Contact: Aimee McKane Waste heat is generated from several industrial systems used in manufacturing. The waste heat sources are distributed throughout a plant. The largest source for most industries is exhaust / flue gases or heated air from heating systems. This includes the high temperature gases from burners in process heating, lower temperature gases from heat treat, dryers, and heaters, heat from heat exchangers, cooling liquids and gases etc. The previous studies and direct contact with the industry as well as equipment suppliers have shown that a large amount of waste heat is not

426

Home heating system  

SciTech Connect

A home heating system is disclosed that has a furnace with a combustion chamber for burning fuel and creating heat, and a chimney with a draft therein. An improvement is described that has an exhaust flue connected between the combustion chamber and the chimney for venting heated exhaust products from the furnace, a heat reclaimer connected into the exhaust flue between the combustion chamber and the chimney for reclaiming heat from the heated exhaust product, and an outside air line for supplying air from the outside of the house to the combustion chamber. A first flue portion of the exhaust flue is connected between the combustion chamber and the heat reclaimer, and a second insulated flue portion of the exhaust flue is connected between the heat reclaimer and the chimney. An outside air by-pass or balancing line is connected between the outside air line and the chimney for satisfying the chimney suction at flame-out. A flow sensing and regulating device may be connected into the outside air line for regulating the flow or air so that outside air is supplied to the furnace only when fuel is burned therein.

Bellaff, L.

1980-03-25T23:59:59.000Z

427

Solar heat regulator  

Science Conference Proceedings (OSTI)

A solar heat regulating device is described for selectively heating with sunlight the air inside a building having a window and shielding and insulating the air inside the building from the heat of sunlight outside the building including: a frame for mounting the solar heat regulating device inside the building and adjacent to the window; a plurality of hollow vanes, each of the vanes having at least one passageway for passing air therethrough; the vanes having a heat absorptive surface on a first side thereof which allows solar radiation impinging on the heat absorptive surface to heat the air contained in the one passageway of the vanes; the vanes having a heat reflective surface on a second side of the vanes which reflects the solar radiation impinging on the second side of the vanes and shields the inside of the building from solar radiation impinging on the vanes; and the vanes having side portions extending between the first and second sides of the vanes, the side portions, and the first and second sides forming the one passageway through each of the vanes, the side portions and the first and second sides of the vanes terminating in top end and bottom end portions.

Boynton, S.L.

1987-04-07T23:59:59.000Z

428

Unstable heat pipes  

DOE Green Energy (OSTI)

Heat pipes are an important feature of models of vapor-dominated geothermal reservoirs. Numerical experiments reveal that a vapor-dominated heat pipe is unstable if pressure is controlled at shallow levels. This instability is discussed in physical terms, and some implications for geothermal reservoirs are considered. 9 refs., 10 figs.

McGuinness, M.J.; Pruess, K.

1987-10-01T23:59:59.000Z

429

Microchannel heat sink assembly  

DOE Patents (OSTI)

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

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

1992-03-24T23:59:59.000Z

430

DECAY HEAT CONDITIONS OF CURRENT AND NEXT GENERATION REACTORS  

E-Print Network (OSTI)

Decay heat is an important parameter in reactor design. Fission products generate heat in the reactor core even when the reactor has shut down. This heat has potential to melt the core if heat removal is not sufficient, and it is what caused the accident in Japan last year. Thus, decay heat must be considered in reactor design for safety. The research focused on decay heat conditions of current and next generation reactors. US-APWR, ABWR, VHTR, and ABR were modeled and simulated using the program SCALE. When the reactors were simulated to operate for two years and cool down for one year, the ABR produced the most decay heat power during operation and cooling time, and the US-APWR, VHTR, and ABWR followed respectfully. Therefore, the ABR requires more coolant and cooling time than other reactors, and the ABWR requires the least.

Choe, JongSoo 1985-

2012-05-01T23:59:59.000Z

431

Air-Source Heat Pumps | Department of Energy  

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

Air-Source Heat Pumps Air-Source Heat Pumps Air-Source Heat Pumps June 24, 2012 - 3:35pm Addthis When properly installed, an air-source heat pump can deliver one-and-a-half to three times more heat energy to a home than the electrical energy it consumes. | Photo courtesy of iStockPhoto/YinYang. When properly installed, an air-source heat pump can deliver one-and-a-half to three times more heat energy to a home than the electrical energy it consumes. | Photo courtesy of iStockPhoto/YinYang. What does this mean for me? If you live in a cooling climate, an air-source heat pump is a good choice. If you live in a heating climate, watch for advanced air-source heat pumps coming on the market that operate well in sub-freezing temperatures. An air-source heat pump can provide efficient heating and cooling for your

432

First university owned district heating system using biomass heat  

E-Print Network (OSTI)

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

Northern British Columbia, University of

433

Heat pipes and use of heat pipes in furnace exhaust  

DOE Patents (OSTI)

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

Polcyn, Adam D. (Pittsburgh, PA)

2010-12-28T23:59:59.000Z

434

Use advisability of heat pumps for building heating and cooling  

Science Conference Proceedings (OSTI)

In the actual economic and energetic juncture, the reduction of thermal energy consumption in buildings became a major, necessary and opportune problem, general significance. The heat pumps are alternative heating installations more energy efficiency ... Keywords: "Geoterm" system, building heating/cooling, energy and economic analysis, heat pump performances, heat pumps, renewable energy sources

Ioan Sârbu; C?lin Sebarchievici

2010-02-01T23:59:59.000Z

435

Solar heating system  

DOE Patents (OSTI)

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

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

1982-01-01T23:59:59.000Z

436

Improved solar heating systems  

DOE Patents (OSTI)

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

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

1980-05-16T23:59:59.000Z

437

Solar heated building structure  

Science Conference Proceedings (OSTI)

A solar heated building structure comprises an exterior shell including side walls and a roof section with the major portion of the roof section comprised of light transmitting panels or panes of material to permit passage of sunlight into the attic section of the building structure. The structure is provided with a central vertical hollow support column containing liquid storage tanks for the circulation and collection of heated water from a flexible conduit system located on the floor of the attic compartment. The central column serves as a heating core for the structure and communicates by way of air conduits or ducts with the living areas of the structure. Fan means are provided for continuously or intermittently circulating air over the hot water storage tanks in the core to transfer heat therefrom and distribute the heated air into the living areas.

Rugenstein, R.W.

1980-03-11T23:59:59.000Z

438

City of Tallahassee Utilities - Solar Water Heating Rebate | Department of  

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

Tallahassee Utilities - Solar Water Heating Rebate Tallahassee Utilities - Solar Water Heating Rebate City of Tallahassee Utilities - Solar Water Heating Rebate < Back Eligibility Installer/Contractor Residential Savings Category Heating & Cooling Solar Water Heating Program Info State Florida Program Type Utility Rebate Program Rebate Amount 450 Provider City of Tallahassee Utilities The City of Tallahassee Utilities offers a $450 rebate to homeowners* and homebuilders who install a solar water-heating system. This rebate may be applied to a first-time installation or to the replacement of an older solar water-heating system. Homebuilders may also apply for the rebate when installing a solar water heater on a new home. Pool heating systems are not eligible for the rebate. The homeowner must allow the City of Tallahassee to conduct an energy audit

439

Advanced Heat Transfer and Thermal Storage Fluids  

DOE Green Energy (OSTI)

The design of the next generation solar parabolic trough systems for power production will require the development of new thermal energy storage options with improved economics or operational characteristics. Current heat-transfer fluids such as VP-1?, which consists of a eutectic mixture of biphenyl and diphenyl oxide, allow a maximum operating temperature of ca. 300 C, a limit above which the vapor pressure would become too high and would require pressure-rated tanks. The use of VP-1? also suffers from a freezing point around 13 C that requires heating during cold periods. One of the goals for future trough systems is the use of heat-transfer fluids that can act as thermal storage media and that allow operating temperatures around 425 C combined with lower limits around 0 C. This paper presents an outline of our latest approach toward the development of such thermal storage fluids.

Moens, L.; Blake, D.

2005-01-01T23:59:59.000Z

440

TVA pilot greenhouse for waste heat research  

SciTech Connect

A pilot facility for evaluating the use of waste heat from power plants, both fossil-fueled and nuclear, to heat a greenhouse was designed and built at the TVA reservation at Muscle Shoals, Ala. The simulation of waste heat was from an electric hot water heater. The subjects to be evaluated included: greenhouse environmental control system operation during one year period under wide range of climatic conditions and the crop performance, i.e., yield and disease control under various controlled-environment conditions and with various rooting media conditions. The facility design, control instrumentation, tests performed, and operating conditions obtained for airflow, air temperature, and humidity are described. No information is included on the crops produced. It is concluded that the pilot facility is providing valuable guidelines for the design of a larger demonstration plant to be located at an operating power plant. (LCL)

King, L.D.; Furlong, W.K.

1973-01-01T23:59:59.000Z

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


441

GEOMETRY, HEAT REMOVAL AND KINETICS SCOPING MODELS FOR HYDROGEN STORAGE SYSTEMS  

DOE Green Energy (OSTI)

It is recognized that detailed models of proposed hydrogen storage systems are essential to gain insight into the complex processes occurring during the charging and discharging processes. Such insight is an invaluable asset for both assessing the viability of a particular system and/or for improving its design. The detailed models, however, require time to develop and run. Clearly, it is much more efficient to begin a modeling effort with a good system design and to progress from that point. To facilitate this approach, it is useful to have simplified models that can quickly estimate optimal loading and discharge kinetics, effective hydrogen capacities, system dimensions and heat removal requirements. Parameters obtained from these models can then be input to the detailed models to obtain an accurate assessment of system performance that includes more complete integration of the physical processes. This report describes three scoping models that assess preliminary system design prior to invoking a more detailed finite element analysis. The three models address the kinetics, the scaling and heat removal parameters of the system, respectively. The kinetics model is used to evaluate the effect of temperature and hydrogen pressure on the loading and discharge kinetics. As part of the kinetics calculations, the model also determines the mass of stored hydrogen per mass of hydride (in a particular reference form). As such, the model can determine the optimal loading and discharge rates for a particular hydride and the maximum achievable loading (over an infinite period of time). The kinetics model developed with the Mathcad{reg_sign} solver, runs in a mater of seconds and can quickly be used to identify the optimal temperature and pressure for either the loading or discharge processes. The geometry scoping model is used to calculate the size of the system, the optimal placement of heat transfer elements, and the gravimetric and volumetric capacities for a particular geometric configuration and hydride. This scoping model is developed in Microsoft Excel{reg_sign} and inputs the mass of hydrogen to be stored, mass of stored hydrogen to mass of hydride (from the kinetics model), component densities, etc. The heat removal scoping model is used to calculate coolant flowrates, pressure drops and temperature increases over the length of the cooling channels. The model also calculates the convection heat transfer coefficient required to remove the heat of reaction associated with hydrogen uptake. The heat removal model inputs dimensions and the mass of hydrogen to be stored directly from the geometry scoping model. Additionally, the model inputs the heats of reaction, the thermal properties of the coolant and the time required to charge the bed.

Hardy, B

2007-11-16T23:59:59.000Z

442

Static Heat Loads in the LHC Arc Cryostats: Final Assessment  

E-Print Network (OSTI)

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

Parma, V

2010-01-01T23:59:59.000Z

443

Radiant Heating | Department of Energy  

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

Radiant Heating Radiant Heating Radiant Heating June 24, 2012 - 5:52pm Addthis In-wall radiant heating in a house under construction near Denver. | Photo courtesy of Warren Gretz, NREL. In-wall radiant heating in a house under construction near Denver. | Photo courtesy of Warren Gretz, NREL. Radiant heating systems supply heat directly to the floor or to panels in the wall or ceiling of a house. The systems depend largely on radiant heat transfer -- the delivery of heat directly from the hot surface to the people and objects in the room via infrared radiation. Radiant heating is the effect you feel when you can feel the warmth of a hot stovetop element from across the room. When radiant heating is located in the floor, it is often called radiant floor heating or simply floor heating.

444

Commercial laundry heat recovery system  

SciTech Connect

In a commercial laundry that is connected to a source of fresh water and generates heated waste water, a method is described for recovering heat from the heated waste comprising the steps of: (a) pumping the heated waste water through a heat exchanger; (b) introducing fresh water into the heat exchanger to receive heat from the waste water through a heat transfer effected by the heat exchanger; (c) withdrawing a first proportion of the heated fresh water at a first temperature; (d) conveying the first proportion of the heated fresh water to cold water storage tank; (e) withdrawing a second proportion of the heated fresh water at a second temperature higher than the first temperature; (f) conveying the second proportion of the heated fresh water to a hot water storage tank.

Kaufmann, R.O.

1986-07-29T23:59:59.000Z

445

Radiant Heating | Department of Energy  

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

Radiant Heating Radiant Heating Radiant Heating June 24, 2012 - 5:52pm Addthis In-wall radiant heating in a house under construction near Denver. | Photo courtesy of Warren Gretz, NREL. In-wall radiant heating in a house under construction near Denver. | Photo courtesy of Warren Gretz, NREL. Radiant heating systems supply heat directly to the floor or to panels in the wall or ceiling of a house. The systems depend largely on radiant heat transfer -- the delivery of heat directly from the hot surface to the people and objects in the room via infrared radiation. Radiant heating is the effect you feel when you can feel the warmth of a hot stovetop element from across the room. When radiant heating is located in the floor, it is often called radiant floor heating or simply floor heating.

446

Heat Recovery Steam Generator Procurement Specification  

Science Conference Proceedings (OSTI)

Many heat recovery steam generators (HRSGs), particularly those equipped with advanced gas turbines that are subjected to periods of frequent cyclic operation, have experienced premature pressure part failures resulting from excessive thermal mechanical fatigue damage. The very competitive power generation marketplace has resulted in the lowest installed cost often taking precedence over medium- and long-term durability and operating costs. The procurement of engineer, procure, and construct ...

2013-12-20T23:59:59.000Z

447

A study of start-up characteristics of a potassium heat pipe from the frozen state  

SciTech Connect

The start-up characteristics of a potassium heat pipe were studied both analytically and experimentally. Using the radiation heat transfer mode the heat pipe was tested in a vacuum chamber. The transition temperature calculated for potassium was then compared with the experimental results of the heat pipe with various heat inputs. These results show that the heat pipe was inactive until it reached the transition temperature. In addition, during the start-up period, the evaporator experienced dry-out with a heat input smaller than the capillary limit calculated at the steady state. However, when the working fluid at the condenser was completely melted, the evaporator was rewetted without external aid. The start-up period was significantly reduced with a large heat input.

Jang, J.H.

1992-04-01T23:59:59.000Z

448

Preliminary Analysis of a Solar Heat Pump System with Seasonal Storage for Heating and Cooling  

E-Print Network (OSTI)

For higher solar fraction and suitability for both heating and cooling, a solar heat pump system with seasonal storage was studied in this paper. The system scheme and control strategy of a solar heat pump system with seasonal storage for heating and cooling were set up, which is responsible for the space heating and cooling and domestic hot water for a residential block. Through hourly simulation, the performance and the economics of such systems were analyzed, for the different tank volumes, operating modes and weather conditions. The results show that 1) for most areas of China, the solar systems with seasonal storage can save energy; 2) for areas with cold winter and hot summer, it is suitable to store heat from summer to winter and store cold energy from winter to summer, but for chilly areas, it is suitable to only store heat from summer to winter; 3) when the ratio of volume of seasonal storage tank to collector areas is 2~3, the system performance is optimal and the payback period is shortest for most areas of north China; and 4) if cooling storage is needed, the seasonal storage coupled with short-term storage may raise the solar fraction largely.

Yu, G.; Chen, P.; Dalenback, J.

2006-01-01T23:59:59.000Z

449

Heat Exchangers for Solar Water Heating Systems | Department...  

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

heat to water in a storage tank. Heat-transfer fluids, such as antifreeze, protect the solar collector from freezing in cold weather. Liquid-to-liquid heat exchangers have...

450

Thermally activated heat pumps  

SciTech Connect

This article describes research to develop efficient gas-fired heat pumps heat and cool buildings without CFCs. Space heating and cooling use 46% of all energy consumed in US buildings. Air-conditioning is the single leading cause of peak demand for electricity and is a major user of chlorofluorocarbons (CFCs). Advanced energy conversion technology can save 50% of this energy and eliminate CFCs completely. Besides saving energy, advanced systems substantially reduce emissions of carbon dioxide (a greenhouse gas), sulfur dioxide, and nitrogen oxides, which contribute to smog and acid rain. These emissions result from the burning of fossil fuels used to generate electricity. The Office of Building Technologies (OBT) of the US Department of Energy supports private industry`s efforts to improve energy efficiency and increase the use of renewable energy in buildings. To help industry, OBT, through the Oak Ridge National Laboratory, is currently working on thermally activated heat pumps. OBT has selected the following absorption heat pump systems to develop: generator-absorber heat-exchange (GAX) cycle for heating-dominated applications in residential and light commercial buildings; double-condenser-coupled (DCC) cycle for commercial buildings. In addition, OBT is developing computer-aided design software for investigating the absorption cycle.

NONE

1995-05-01T23:59:59.000Z

451

Design, development and testing of a solar-powered multi-family residential-size prototype turbocompressor heat pump  

DOE Green Energy (OSTI)

An experimental program was conducted to further define, improve and demonstrate the performance characteristics and operational features of an existing 18-ton solar-powered prototype heat pump. The prototype heat pump is nominally sized for multi-family residential applications and provides both space heating and cooling. It incorporates a turbocompressor specially designed to operate at peak temperatures consistent with medium concentration collectors. The major efforts in this program phase included modification and improvement of the instrumentation sensors, the laboratory simulation equipment and selected heat pump components. After implementing these modifications, performance testing was conducted for a total operating time of approximately 250 hours. Experimental test results compared favorably with performance data calculated using the UTRC computer prediction program for the same boundary conditions. A series of tests was conducted continuously over a 12-h period to simulate operation (in the cooling mode) of the prototype heat pump under conditions typical of an actual installation. The test demonstrated that the heat pump could match the cooling load profile of a multi-family residential building. During the system performance testing, sufficient data were taken to identify the performance of each of the major components (e.g. turbine, compressor, heat exchangers, R11 pump). Component performance is compared with that calculated using the UTRC computer predict program and with data supplied by their manufacturers. The performance capabilities of the prototype heat pump system have been documented and recommendations are made for further design improvements which could be included in a MOD-2 configuration. The MOD-2 configuration would incorporate features that would improve system performance, reduce capital cost and most importantly improve system reliability.

Not Available

1982-10-01T23:59:59.000Z

452

Stirling engine heating system  

SciTech Connect

A hot gas engine is described wherein a working gas flows back and forth in a closed path between a relatively cooler compression cylinder side of the engine and a relatively hotter expansion cylinder side of the engine and the path contains means including a heat source and a heat sink acting upon the gas in cooperation with the compression and expansion cylinders to cause the gas to execute a thermodynamic cycle wherein useful mechanical output power is developed by the engine, the improvement in the heat source which comprises a plurality of individual tubes each forming a portion of the closed path for the working gas.

Johansson, L.N.; Houtman, W.H.; Percival, W.H.

1988-06-28T23:59:59.000Z

453

Forecast of heat demand according the Box-Jenkins methodology for specific locality  

Science Conference Proceedings (OSTI)

In order to improve the control level of district-heating systems, it is necessary for the energy companies to have reliable optimization routines, implemented in their organizations. However, before a plan of heat production, a prediction of the heat ... Keywords: box-Jenkins, control algorithms, district heating control, prediction, time series analysis

Bronislav Chramcov

2010-07-01T23:59:59.000Z

454

Research of Refrigerant Phase-Change Stirling-Cycle Heat Engines  

Science Conference Proceedings (OSTI)

This paper firstly introduces the principles of Refrigerant Phase-Change Stirling-Cycle solar power towers This heat engines use solar reservoire. When the refrigerant in an engine cylinder absorbs heat from high-temperature heat sources, refrigerant ... Keywords: refrigerant phase-change cycle, heat engines, finite-time thermodynamics

Dezhong Huang; Fuer Wu

2011-01-01T23:59:59.000Z

455

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

DOE Green Energy (OSTI)

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

Not Available

1994-10-01T23:59:59.000Z

456

RadHeat V1 User's Manual  

SciTech Connect

RadHeat is a one dimensional finite difference heat transfer code that can determine the transient temperature evolution of layered targets in pulsed penetrating radiation environments. It makes use of energy dependent opacity and stopping data to model the volumetric deposition of any number of photon or ion spectra each incident at arbitrary angles. Convective and radiative boundary conditions are handled as well as the ability to impose any initial temperature profile. The heat diffusion equation is formulated implicitly to eliminate timestep dependent stability issues. Simulations are, therefore, able to achieve high fidelity during times of thermal activity and greater speed elsewhere. The prototypical physical situation simulated by RadHeat is illustrated. RadHeat was originally written to study the temperature response of tungsten-armored target-facing walls to the pulsed photon and ion radiation emanating from fusion microexplosions in future IFE power plants. RadHeat's implementation is quite general, though, and the code can be applied to a very broad range of problems. Anything from the heating of the Earth's crust on a warm summer day to the temperature rise in a mirror after a laser pulse could potentially be modeled. This manual was written to help new users learn how to run the code and introduce them to the simulation tools it provides.

Abbott, R P

2005-01-03T23:59:59.000Z

457

Heat Transfer Fluids for Solar Water Heating Systems | Department...  

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

exchanger. | Photo from iStockphoto.com Heat Exchangers for Solar Water Heating Systems Rooftop solar water heaters need regular maintenance to operate at peak efficiency. |...

458

Potassium, Uranium, Thorium Radiogenic Heat Contribution To Heat...  

Open Energy Info (EERE)

Potassium, Uranium, Thorium Radiogenic Heat Contribution To Heat Flow In The Precambrian And Younger Silicic Rocks Of The Zuni And Florida Mountains, New Mexico (Usa) Jump to:...

459

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

Open Energy Info (EERE)

Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Features And Examples Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow,...

460

Waste Heat Recovery from Industrial Process Heating Equipment...  

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

Waste Heat Recovery from Industrial Process Heating Equipment - Cross-cutting Research and Development Priorities Speaker(s): Sachin Nimbalkar Date: January 17, 2013 - 11:00am...

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


461

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

SciTech Connect

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

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

2012-08-21T23:59:59.000Z

462

Mixed-convective, conjugate heat transfer during molten salt quenching of small parts  

Science Conference Proceedings (OSTI)

It is common in free quenching immersion heat treatment calculations to locally apply constant or surface-averaged heat-transfer coefficients obtained from either free or forced steady convection over simple shapes with small temperature differences from the ambient fluid. This procedure avoids the solution of highly transient, non-Boussinesq conjugate heat transfer problems which often involve mixed convection, but it leaves great uncertainty about the general adequacy of the results. In this paper we demonstrate for small parts (dimensions of the order of inches rather than feet) quenched in molten salt, that it is feasible to calculate such nonuniform surface heat transfer from first principles without adjustable empirical parameters. We use literature physical property salt data from the separate publications of Kirst et al., Nissen, Carling, and Teja, et al. for T800 F is not considered to be important due to the short time the surface temperature exceeds that value for small parts. Similarly, for small parts, the local Reynolds and Rayleigh numbers are below the corresponding critical values for most if not all of the quench, so that we see no evidence of the existence of significant turbulence effects, only some large scale unsteadiness for brief periods. The experimental data comparisons from the open literature include some probe cooling-rate results of Foreman, as well as some cylinder thermal histories of Howes.

Chenoweth, D.R.

1997-02-01T23:59:59.000Z

463