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1

Dehumidifying Heat Pipes | Department of Energy  

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

Dehumidifying Heat Pipes Dehumidifying Heat Pipes Dehumidifying Heat Pipes June 24, 2012 - 4:32pm Addthis In order to make a room comfortable in hot, humid climates, an air conditioner must lower the indoor humidity level as well as the air temperature. If an air conditioner fails to lower the humidity adequately, the air will be cool, but will feel uncomfortably damp. Inappropriately sized air conditioners are prone to this problem; large units quickly cool the air, but cycle off before they can properly dehumidify it. In extremely humid climates, even correctly sized air conditioning equipment could fail to maintain a home at a comfortable humidity level. One technology that addresses this problem is the dehumidifying heat pipe, a device that enables an air conditioner to dehumidify better and still

2

Performance Test and Energy Saving Analysis of a Heat Pipe Dehumidifier  

E-Print Network (OSTI)

Heat pipe technology applied to ventilation, dryness, and cooling and heating radiator in a building is introduced in this paper. A new kind of heat pipe dehumidifier is designed and tested. The energy-saving ratio with the heat pipe dehumidifier ranges from 11.81% to 30.34% compared with the normal dehumidifier, according to the performance testing. The dehumidification capacity and the surface cooler power increases, but the energy saving ratio is reduced with the increase of air relative humidity, dry bulb temperature and air quantity

Zhao, X.; Li, Q.; Yun, C.

2006-01-01T23:59:59.000Z

3

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

4

Water-heating dehumidifier - Energy Innovation Portal  

A water-heating dehumidifier includes a refrigerant loop including a compressor, at least one condenser, an expansion device and an evaporator including an evaporator ...

5

A desiccant dehumidifier for electric vehicle heating  

DOE Green Energy (OSTI)

Vehicle heating requires a substantial amount of energy. Engines in conventional cars produce enough waste heat to provide comfort heating and defogging/defrosting, even under very extreme conditions. Electric vehicles (EVs), however, generate little waste heat. Using battery energy for heating may consume a substantial fraction of the energy storage capacity, reducing the vehicle range, which is one of the most important parameters in determining EV acceptability. Water vapor generated by the vehicle passengers is in large part responsible for the high heating loads existing in vehicles. In cold climates, the generation of water vapor inside the car may result in water condensation on the windows, diminishing visibility. Two strategies are commonly used to avoid condensation on windows: windows are kept warm, and a large amount of ambient air is introduced in the vehicle. Either strategy results in a substantial heating load. These strategies are often used in combination, and a trade-off exists between them. If window temperature is decreased, ventilation rate has to be increased. Reducing the ventilation rate requires an increase of the temperature of the windows to prevent condensation. An alternative solution is a desiccant dehumidifier, which adsorbs water vapor generated by the passengers. Window temperatures and ventilation rates can then be reduced, resulting in a substantially lower heating load. This paper explores the dehumidifier heating concept. The first part shows the energy savings that could be obtained by using this technology. The second part specifies the required characteristics and dimensions of the system. The results indicate that the desiccant system can reduce the steady-state heating load by 60% or more under typical conditions. The reduction in heating load is such that waste heat may be enough to provide the required heating under most ambient conditions. Desiccant system dimensions and weight appear reasonable for packaging in an EV.

Aceves, S.M.; Smith, J.R.

1996-09-01T23:59:59.000Z

6

Heat and mass transfer analysis of a desiccant dehumidifier matrix  

DOE Green Energy (OSTI)

This report documents the SERI Single-Blow Test Facility's design, fabrication, and testing for characterizing desiccant dehumidifiers for solar cooling applications. The first test article, a silica-gel parallel-plate dehumidifier with highly uniform passages, was designed and fabricated. Transient heat and mass transfer data and pressure drop data across the dehumidifier were obtained. Available heat and mass transfer models were extended to the parallel-place geometry, and the experimental data were compared with model predictions. Pressure drop measurements were also compared with model predictions of the fully developed laminar flow theory. The comparisons between the lumped-capacitance model and the experimental data were satisfactory. The pressure drop data compared satisfactorily with the theory (within 15%). A solid-side resistance model that is more detailed and does not assume symmetrical diffusion in particles was recommended for performance. This study has increased our understanding of the heat and mass transfer in silica gel parallel-plate dehumidifiers.

Pesaran, A.A.

1986-07-01T23:59:59.000Z

7

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

8

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

9

Convective heat and mass transfer in compact regenerative dehumidifiers  

Science Conference Proceedings (OSTI)

Regular-density silica gel is identified as the candidate desiccant for regenerative dehumidification of humid air operating at low-regeneration temperatures and high-process humidities. The literature on the equilibrium sorption uptake of water vapor by R. D. silica gel is reviewed in this work, and a large number of experimental sorption data is collected from various technical reports. The Dubinin-Polanyi sorption theory for microporous adsorbents is discussed and applied to the sorptive data. A graphical presentation of the experimental data establishes the characteristic curve for the sorption of water vapor on silica gel. The Dubinin-Astakhov correlation is used to represent the equilibrium sorption isotherm and values for the characteristic sorption energies are determined by curve fitting with the experimental data. An accurate, generalized isotherm equation for the sorption of water vapor on regular density silica gel is presented in the first part of this work. The second part of this work presents an analytical and experimental investigation of the transient heat and mass transfer in laminar flow of humid air over a silica gel surface. Experimental results are presented for the transient response of a parallel-plate dehumidifier matrix in single-blow type experiments.

Van den Buick, E.

1987-01-01T23:59:59.000Z

10

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

11

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

12

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

13

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

14

Supporting Equipment for Heating and Cooling Systems  

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

Thermostats and ducts provide opportunities for saving energy. Dehumidifying heat pipes provide a way to help central air conditioners and heat pumps dehumidify air. Electric and gas meters allow users to track energy use.

15

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

16

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

17

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

18

Energy Basics: Supporting Equipment for Heating and Cooling Systems  

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

for Heating and Cooling Systems Thermostats and ducts provide opportunities for saving energy. Dehumidifying heat pipes provide a way to help central air conditioners and heat...

19

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

20

Experimental studies of heat and mass exchange in parallel-passage rotary desiccant dehumidifiers for solar cooling applications  

DOE Green Energy (OSTI)

This report presents results of work done to experimentally characterize the performance of rotary desiccant dehumidifiers and to develop and validate analytical methods for evaluating their performance in air-conditioning systems. A facility, the Cyclic Test Facility, and a test-and-analysis procedure were developed to evaluate the performance of the rotary dehumidifiers. Experiments were performed to develop a basic understanding of the simultaneous heat- and mass-transfer processes in the dehumidifiers. Two test articles were tested under cyclic operation to characterize their performance. Detailed accounts of the Cyclic Test Facility, its hardware and instrumentation, the two test articles, and data reduction and analysis methods are provided. The data provide an engineering data base for evaluating rotary desiccant dehumidifiers for cooling applications. 46 refs., 26 figs., 3 tabs.

Bharathan, D.; Parsons, J.M.; Maclaine-cross, I.L.

1987-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

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

22

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

23

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

24

Freezable heat pipe  

SciTech Connect

A heat pipe whose fluid can be repeatedly frozen and thawed without damage to the casing. An additional part is added to a conventional heat pipe. This addition is a simple porous structure, such as a cylinder, self-supporting and free standing, which is dimensioned with its diameter not spanning the inside transverse dimension of the casing, and with its length surpassing the depth of maximum liquid.

Ernst, Donald M. (Leola, PA); Sanzi, James L. (Lancaster, PA)

1981-02-03T23:59:59.000Z

25

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

26

Variable conductance heat pipe enhancement  

SciTech Connect

This patent describes a heat pipe. It comprises a tubular hollow heat pipe having an evaporator end and an opposite condenser end, the heat pipe having a cross-sectional area and having a condenser length extending from the condenser end the condenser length including an active length where evaporated fluid condenses; an evaporatable and condensable fluid in the heat pipe for evaporating when receiving heat near the evaporation end and for condensing when giving up heat in the active length; a noncondensable gas near the condenser end and in the condenser length of the heat pipe; a restriction member fixed in the heat pipe near the condenser end, the restriction member extending only along a portion of the condenser length and being spaced away from the evaporation end of the heat pipe, the restriction member having a varied cross-sectional area along the length of the restriction member which is less than the cross-sectional area of the heat pipe for confining the gas and a portion of the fluid in the active condenser length, to an area around the restriction member and in the heat pipe; and a fixed ligament connected between the restriction member and the heat pipe for fixing the restriction member in the heat pipe, the ligament being fixed between the condenser end of the heat pipe end and an end of the restriction member which is closest to the condenser end.

Kneidel, K.E.

1991-09-03T23:59:59.000Z

27

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

28

Heat pipe applications workshop report  

SciTech Connect

The proceedings of the Heat Pipe Applications Workshop, held at the Los Alamos Scientific Laboratory October 20-21, 1977, are reported. This workshop, which brought together representatives of the Department of Energy and of a dozen industrial organizations actively engaged in the development and marketing of heat pipe equipment, was convened for the purpose of defining ways of accelerating the development and application of heat pipe technology. Recommendations from the three study groups formed by the participants are presented. These deal with such subjects as: (1) the problem encountered in obtaining support for the development of broadly applicable technologies, (2) the need for applications studies, (3) the establishment of a heat pipe technology center of excellence, (4) the role the Department of Energy might take with regard to heat pipe development and application, and (5) coordination of heat pipe industry efforts to raise the general level of understanding and acceptance of heat pipe solutions to heat control and transfer problems.

Ranken, W.A.

1978-04-01T23:59:59.000Z

29

List of Dehumidifiers Incentives | Open Energy Information  

Open Energy Info (EERE)

Dehumidifiers Incentives Dehumidifiers Incentives Jump to: navigation, search The following contains the list of 159 Dehumidifiers Incentives. CSV (rows 1 - 159) Incentive Incentive Type Place Applicable Sector Eligible Technologies Active AEP Ohio (Gas) - Residential Energy Efficiency Rebate Program (Ohio) Utility Rebate Program Ohio Residential Building Insulation Ceiling Fan Central Air conditioners Custom/Others pending approval Dehumidifiers Duct/Air sealing Heat pumps Lighting Motors Programmable Thermostats Windows Yes Alexandria Light and Power - Residential Energy Efficiency Rebate Program (Minnesota) Utility Rebate Program Minnesota Residential Central Air conditioners Clothes Washers Dehumidifiers Dishwasher Energy Mgmt. Systems/Building Controls Heat pumps Lighting

30

Solar heat pipe feedback turbogenerator  

SciTech Connect

The conversion of radiant heat to electricity by a heat pipe-turbogenerator combination is described. The heat pipe-tubogenerator assembly is suitably externally insulated, as by a vacuum shield, to prevent heat losses and heat is recovered from the condenser portion of the heat pipe and returned to the evaporator portions. An application of the generic invention is discussed which it is employed on wall or roof portions of a building and serves as at least a partial supporting structure for these. In another application the solar heat pipe feedback turbogenerator may be incorporated in or used with reflective means, such as reflective sheet material of large area positioned to direct solar radiation onto the evaporator section of the heat pipe. The reflective means may be changed in position to follow the sun to produce maximum power during operation.

Decker, B.J.

1978-10-24T23:59:59.000Z

31

Performance optimization of rotary dehumidifiers  

SciTech Connect

A rotary dehumidifier consists of a rotating porous matrix made of a desiccant with mechanically supporting materials. The dehumidification performance of a rotary dehumidifier wheel depends on its rotational speed, the sorption properties of the desiccant, the heat and mass transfer characteristics of the matrix, and the size of the dehumidifier. The effect of the rotational speed on the dehumidification performance of a rotary dehumidifier has been investigated by Zheng, Worek, and Novosel (1993). this paper extends that previous work and investigates the effects of desiccant sorption properties, the heat and mass transfer characteristics, and the size of the rotary dehumidifier on the dehumidification performance. The results show that the using desiccant materials in a rotary dehumidifier with different adsorption characteristics results in a wide variation in dehumidification performance. However, the maximum performance of a rotary dehumidifier occurs for a desiccant material having an isotherm shape that can be characterized to have a separation factor of 0.07. Also, as the desiccant moisture uptake increases, the dehumidifier performance also increases. However, the performance improvement for a desiccant matrix having a maximum moisture uptake of larger than 0.25 by weight is not significant. The heat and mass transfer properties and the size of rotary dehumidifier are characterized by the number of transfer units NTU. Generally, the larger the NTU, the better dehumidification performance. However, similar to the maximum moisture uptake, when the NTU is larger than 12, the performance will not improve significantly. Also, the dehumidifier with the most favorable adsorption characteristic has a slower rotational speed, which results in lower power requirements to rotate the desiccant wheel and smaller carry-over losses.

Zheng, W.; Worek, W.M. [Univ. of Chicago, IL (United States). Dept. of Mechanical Engineering; Novosel, D. [Gas Research Inst., Chicago, IL (United States)

1995-02-01T23:59:59.000Z

32

Heat pipe transient response approximation.  

SciTech Connect

A simple and concise routine that approximates the response of an alkali metal heat pipe to changes in evaporator heat transfer rate is described. This analytically based routine is compared with data from a cylindrical heat pipe with a crescent-annular wick that undergoes gradual (quasi-steady) transitions through the viscous and condenser boundary heat transfer limits. The sonic heat transfer limit can also be incorporated into this routine for heat pipes with more closely coupled condensers. The advantages and obvious limitations of this approach are discussed. For reference, a source code listing for the approximation appears at the end of this paper.

Reid, R. S. (Robert Stowers)

2001-01-01T23:59:59.000Z

33

Heat Pipes: An Industrial Application  

E-Print Network (OSTI)

This paper reviews the basics of heat pipe exchangers. Included are how they are constructed, how they operate, where they have application, and various aspects of evaluating a potential application. After discussing the technical aspects of heat pipe exchangers, an industrial case history is presented. The case history involves a retrofit project which added heat pipes to five natural draft process heaters with a combined heat duty of 150 M Btu/hr. A heat recovery of 15 M Btu/hr has resulted from the flue gas/combustion air interchange. The paper will include design considerations, and operating and maintenance history since early 1980. A second application for heat pipes with a 12 M Btu/hr duty installed in 1983 will also be discussed.

Murray, F.

1984-01-01T23:59:59.000Z

34

Heat pipe turbine vane cooling  

SciTech Connect

The applicability of using heat pipe principles to cool gas turbine vanes is addressed in this beginning program. This innovative concept involves fitting out the vane interior as a heat pipe and extending the vane into an adjacent heat sink, thus transferring the vane incident heat transfer through the heat pipe to heat sink. This design provides an extremely high heat transfer rate and a uniform temperature along the vane due to the internal change of phase of the heat pipe working fluid. Furthermore, this technology can also eliminate hot spots at the vane leading and trailing edges and increase the vane life by preventing thermal fatigue cracking. There is also the possibility of requiring no bleed air from the compressor, and therefore eliminating engine performance losses resulting from the diversion of compressor discharge air. Significant improvement in gas turbine performance can be achieved by using heat pipe technology in place of conventional air cooled vanes. A detailed numerical analysis of a heat pipe vane will be made and an experimental model will be designed in the first year of this new program.

Langston, L.; Faghri, A. [Connecticut Univ., Storrs, CT (United States). Dept. of Mechanical Engineering

1995-12-31T23:59:59.000Z

35

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

36

Heat pipe technology quarterly literature review. Volume 1, Number 3  

SciTech Connect

A bibliography containing 110 citations is presented. The citations are arranged in five sections on general information on heat pipes, heat pipe applications, heat pipe theory, heat pipe design, development, and fabrication, and heat pipe testing and operation.

Srinivasan, R.; Gonzales, R.W. (eds.)

1983-01-01T23:59:59.000Z

37

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

38

Experimental Investigation of Bendable Heat Pipes.  

E-Print Network (OSTI)

??Heat pipes are highly conductive heat transfer devices. They use the latent heat of the working fluid for efficient heat transfer over a very small… (more)

ODHEKAR, DHANANJAY

2005-01-01T23:59:59.000Z

39

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

40

Heat pipe device and heat pipe fabricating process  

Science Conference Proceedings (OSTI)

An energy saving liquid to liquid heat exchanger for a dishwasher or like device discharging hot waste water comprising a hot water tank for holding the waste water from the dishwasher and having inlet and outlet pipes, a cold water tank for holding the fresh water going to a water heater and having inlet and outlet pipes, the cold water tank disposed on top of the hot water tank, a bundle of heat pipes containing low boiling refrigerant disposed inside of the two tanks so as to extract heat from the hot water tank and give it up to the cold water tank, whereby the temperature of the fresh water leaving the heat exchanger is higher than its entering temperature.

Busch, C.H.

1982-08-10T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Micro-Columnated Loop Heat Pipe: The Future of Electronic Substrates  

E-Print Network (OSTI)

Loop Heat Pipes . . . . . . . . . . . . . . . . . . . .Heat Pipes . . . . . . . . . . . . . . . . . . . . . . . .of operation of a heat pipe [13]. . . . . . . . . . . . . .

Dhillon, Navdeep Singh

2012-01-01T23:59:59.000Z

42

Magnetic refrigeration apparatus with heat pipes  

DOE Patents (OSTI)

A magnetic refrigerator operating in the 4 to 20 K range utilizes heat pipes to transfer heat to and from the magnetic material at the appropriate points during the material's movement. In one embodiment circular disks of magnetic material can be interleaved with the ends of the heat pipes. In another embodiment a mass of magnetic material reciprocatingly moves between the end of the heat pipe or pipes that transmits heat from the object of cooling to the magnetic material and the end of the heat pipe or pipes that transmits heat from the magnetic material to a heat sink.

Barclay, J.A.; Prenger, F.C. Jr.

1985-10-25T23:59:59.000Z

43

Magnetic refrigeration apparatus with heat pipes  

DOE Patents (OSTI)

A magnetic refrigerator operating in the 4 to 20 K range utilizes heat pipes to transfer heat to and from the magnetic material at the appropriate points during the material's movement. In one embodiment circular disks of magnetic material can be interleaved with the ends of the heat pipes. In another embodiment a mass of magnetic material reciprocatingly moves between the end of the heat pipe of pipes that transmits heat from the object of cooling to the magnetic material and the end of the heat pipe or pipes that transmits heat from the magnetic material to a heat sink.

Barclay, John A. (Los Alamos, NM); Prenger, Jr., F. Coyne (Madison, WI)

1987-01-01T23:59:59.000Z

44

Heat pipe dynamics. Final report, April 30, 1981. [Uses of heat pipe, especially in solar collector  

DOE Green Energy (OSTI)

A heat-pipe flat plate solar collector is constructed like a typical flat plate collector with the exception that individual heat pipes are attached to the collector surface to transfer collected heat via a phase change from collector surface into an attached jacket containing a phase change material. The efficiency of such a collector was measured roughly. Also briefly described are: a heat-pipe heat exchanger, heat-pipe heat exchanger freeze proofing, heat-pipe attic ventilation, transfer of light bulb heat via a heat pipe to heat water, heat recovery via heat pipe, cooling of oil in engines and transmissions via heat pipe, a tracking reflector, automatic sun tracker, single-stroke vacuum pump for heat-pipe manufacture, and heat pipe heat transfer from rock bed. (LEW)

Norman, R.M. Sr.

1981-01-01T23:59:59.000Z

45

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

46

Heat pipe thermal control of irradiation capsules  

SciTech Connect

From 1st international heat pipe conference; Stuttgart, F.R. Germany (15 Oct 1973). The use of heat pipes to control the temperature of irradiation capsules containing fast breeder reactor structural materials is discussed. (TFD)

Deverall, J.E.

1974-04-30T23:59:59.000Z

47

Flat heat pipe design, construction, and analysis  

SciTech Connect

This paper details the design, construction and partial analysis of a low temperature flat heat pipe in order to determine the feasibility of implementing flat heat pipes into thermophotovoltaic (TPV) energy conversion systems.

Voegler, G.; Boughey, B.; Cerza, M.; Lindler, K.W.

1999-08-02T23:59:59.000Z

48

Dual manifold heat pipe evaporator  

DOE Patents (OSTI)

An improved evaporator section is described for a dual manifold heat pipe. Both the upper and lower manifolds can have surfaces exposed to the heat source which evaporate the working fluid. The tubes in the tube bank between the manifolds have openings in their lower extensions into the lower manifold to provide for the transport of evaporated working fluid from the lower manifold into the tubes and from there on into the upper manifold and on to the condenser portion of the heat pipe. A wick structure lining the inner walls of the evaporator tubes extends into both the upper and lower manifolds. At least some of the tubes also have overflow tubes contained within them to carry condensed working fluid from the upper manifold to pass to the lower without spilling down the inside walls of the tubes. 1 figure.

Adkins, D.R.; Rawlinson, K.S.

1994-01-04T23:59:59.000Z

49

Dual manifold heat pipe evaporator  

DOE Patents (OSTI)

An improved evaporator section for a dual manifold heat pipe. Both the upper and lower manifolds can have surfaces exposed to the heat source which evaporate the working fluid. The tubes in the tube bank between the manifolds have openings in their lower extensions into the lower manifold to provide for the transport of evaporated working fluid from the lower manifold into the tubes and from there on into the upper manifold and on to the condenser portion of the heat pipe. A wick structure lining the inner walls of the evaporator tubes extends into both the upper and lower manifolds. At least some of the tubes also have overflow tubes contained within them to carry condensed working fluid from the upper manifold to pass to the lower without spilling down the inside walls of the tubes.

Adkins, Douglas R. (Albuquerque, NM); Rawlinson, K. Scott (Albuquerque, NM)

1994-01-01T23:59:59.000Z

50

Aircraft Thermal Management Using Loop Heat Pipes.  

E-Print Network (OSTI)

??The objective of this thesis was to determine the feasibility of using loop heat pipes to dissipate waste heat from power electronics to the skin… (more)

Fleming, Andrew J.

2009-01-01T23:59:59.000Z

51

Heat pipe with embedded wick structure  

SciTech Connect

A heat pipe has an embedded wick structure that maximizes capillary pumping capability. Heat from attached devices such as integrated circuits evaporates working fluid in the heat pipe. The vapor cools and condenses on a heat dissipation surface. The condensate collects in the wick structure, where capillary pumping returns the fluid to high heat areas.

Adkins, Douglas Ray (Albuquerque, NM); Shen, David S. (Albuquerque, NM); Tuck, Melanie R. (Albuquerque, NM); Palmer, David W. (Albuquerque, NM); Grafe, V. Gerald (Corrales, NM)

1999-01-01T23:59:59.000Z

52

Heat pipe with embedded wick structure  

DOE Patents (OSTI)

A heat pipe has an embedded wick structure that maximizes capillary pumping capability. Heat from attached devices such as integrated circuits evaporates working fluid in the heat pipe. The vapor cools and condenses on a heat dissipation surface. The condensate collects in the wick structure, where capillary pumping returns the fluid to high heat areas. 7 figs.

Adkins, D.R.; Shen, D.S.; Tuck, M.R.; Palmer, D.W.; Grafe, V.G.

1998-06-23T23:59:59.000Z

53

Heat pipe with embedded wick structure  

SciTech Connect

A heat pipe has an embedded wick structure that maximizes capillary pumping capability. Heat from attached devices such as integrated circuits evaporates working fluid in the heat pipe. The vapor cools and condenses on a heat dissipation surface. The condensate collects in the wick structure, where capillary pumping returns the fluid to high heat areas.

Adkins, Douglas Ray (Albuquerque, NM); Shen, David S. (Albuquerque, NM); Tuck, Melanie R. (Albuquerque, NM); Palmer, David W. (Albuquerque, NM); Grafe, V. Gerald (Corrales, NM)

1998-01-01T23:59:59.000Z

54

Heat pipe theory and practice: a sourcebook  

SciTech Connect

An introduction to heat pipe operating principles, types, and applications followed by a comprehensive treatment of heat pipe theory, design, and manufacture are presented. The organization of heat pipe theory provides parallel treatment of the fundamental laws of thermodynamics, heat transfer, fluid mechanics, and materials science during heat pipe analysis. For the problem-solving convenience of practicing engineers, design procedures are developed summarizing theoretical information. Methods of summarizing voluminous research information are presented in detail. Current practices in the manufacture of heat pipes are described. Current and potential applications of the heat pipe to energy systems discussed are: heat exchangers, heat recovery for HVAC systems, residential buildings, industrial processes, gasification plants, and thermal storage subsystems.

Chi, S.W.

1976-01-01T23:59:59.000Z

55

Heat-Pipe Wick Characterization  

SciTech Connect

The development of liquid metal heat-pipes for use in solar powered Stirling engines has led to an in-depth analysis of heat-pipe wick properties. To model the flow of liquid sodium through the wick its two-phase permeability measurement is of interest. The permeability will be measured by constructing a test cell made up of a wick sample sintered to a manifold. Measuring the volumetric flow rate through the wick will allow for a determination of the wick's permeability as a function of pressure. Currently, simple estimates of permeability as a function of vapor fraction of a porous media are being used as a model to calculate the two-phase permeability. The above mentioned experiment will be used to test the existing formulas validity. The plan is to make use of a known procedure for testing permeability and apply those techniques to a felt-metal wick. The results will be used to verify and/or modify the two-phase permeability estimates. With the increasing desire to replace directly illuminated engines with the much more efficient heat-pipe apparatus it is inherently clear that the usefulness of known wick properties will make wick permeability design a simpler process.

JONES II,JERRY LEE

2000-08-15T23:59:59.000Z

56

Heat-Pipe Wick Characterization  

DOE Green Energy (OSTI)

The development of liquid metal heat-pipes for use in solar powered Stirling engines has led to an in-depth analysis of heat-pipe wick properties. To model the flow of liquid sodium through the wick its two-phase permeability measurement is of interest. The permeability will be measured by constructing a test cell made up of a wick sample sintered to a manifold. Measuring the volumetric flow rate through the wick will allow for a determination of the wick's permeability as a function of pressure. Currently, simple estimates of permeability as a function of vapor fraction of a porous media are being used as a model to calculate the two-phase permeability. The above mentioned experiment will be used to test the existing formulas validity. The plan is to make use of a known procedure for testing permeability and apply those techniques to a felt-metal wick. The results will be used to verify and/or modify the two-phase permeability estimates. With the increasing desire to replace directly illuminated engines with the much more efficient heat-pipe apparatus it is inherently clear that the usefulness of known wick properties will make wick permeability design a simpler process.

JONES II,JERRY LEE

2000-08-15T23:59:59.000Z

57

Development of a cryogenic heat pipe  

SciTech Connect

Heat pipe operating characteristics can be used to advantage in cryogenic systems. Diode operation of the heat pipe, the ability to conduct heat in one direction only, is useful in protecting the heat load if the heat sink temperature rises above the load temperature. Because of this, the heat pipe can be made to act as a thermal switch. A screened-wick, inverted-artery, cryogenic heat pipe was designed, fabricated, and tested. The tests were first conducted with hydrogen and then with oxygen as the working fluid. Heat pipe performance limits were measured as a function of operating temperature, and startup from both the supercritical and the frozen state was demonstrated. The heat pipe was designed to operate as a thermal diode, and transient tests were used to determine the turndown ratio. The heat pipe test results were correlated with the Los Alamos heat pipe computer code and good agreement was obtained between the predicted and measured performance. The heat pipe was developed for spacecraft sensor cooling applications. Test results show significant performance advantages over solid conductors.

Prenger, F.C.; Stewart, W.F.; Runyan, J.E.

1993-08-01T23:59:59.000Z

58

Solar powered dehumidifier apparatus  

SciTech Connect

A thermally insulated light transmitting housing forms a chamber containing a desiccant and having a first gas port open to the ambient and a second gas port connected by a two way valve to a volume to be dried. Solar energy transmitted through the housing heats and dries the desiccant. The increased air pressure due to the heating of the volume to be dried causes the air from the volume to be expelled through the valve into the chamber. The desiccant is then cooled by shielding it from solar energy before the volume cools thereby increasing its moisture absorbing capacity. Then the volume is allowed to cool drawing dehumidified air through the desiccant and the valve into the volume to be dried. This cycle is then repeated.

Jebens, Robert W. (Skillman, NJ)

1980-12-30T23:59:59.000Z

59

Rotating heat pipe for air-conditioning  

SciTech Connect

A unique rotary hermetic heat pipe is disclosed for transferring heat from an external source to an external heat sink. The heat pipe has a tapered condensing surface which is curved preferably to provide uniform pumping acceleration, the heat pipe being rotated at a velocity such that the component of centrifugal acceleration in an axial direction parallel to the tapered surface is greater than lG and so that the condensing surface is kept relatively free of liquid at any attitude. The heat pipe may be incorporated in an air conditioning apparatus so that it projects through a small wall opening. In the preferred air conditioning apparatus, a hollow hermetic air impeller is provided which contains a liquefied gaseous refrigerant, such as freon, and means are provided for compressing the refrigerant in the evaporator region of the heat pipe.

Gray, V.H.

1976-12-28T23:59:59.000Z

60

Glass heat pipe evacuated tube solar collector  

DOE Patents (OSTI)

A glass heat pipe is adapted for use as a solar energy absorber in an evacuated tube solar collector and for transferring the absorbed solar energy to a working fluid medium or heat sink for storage or practical use. A capillary wick is formed of granular glass particles fused together by heat on the inside surface of the heat pipe with a water glass binder solution to enhance capillary drive distribution of the thermal transfer fluid in the heat pipe throughout the entire inside surface of the evaporator portion of the heat pipe. Selective coatings are used on the heat pipe surface to maximize solar absorption and minimize energy radiation, and the glass wick can alternatively be fabricated with granular particles of black glass or obsidian.

McConnell, Robert D. (Lakewood, CO); Vansant, James H. (Tracy, CA)

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Heat pipe nuclear reactor for space power  

SciTech Connect

A heat-pipe cooled nuclear reactor has been designed to provide 3.2 MW(t) to an out-of-core thermionic conversion system. The reactor is a fast reactor designed to operate at a nominal heat pipe temperature of 1675/sup 0/K. Each reactor fuel element consists of a hexagonal molybdenum block which is bonded along its axis to one end of a molybdenum, lithium vapor, heat pipe. The block is perforated with an array of longitudinal holes which are loaded with UO/sub 2/ pellets. The heat pipe transfers heat directly to a string of six thermionic converters which are bonded along the other end of the heat pipe. An assembly of 90 such fuel elements forms a hexagonal core. The core is surrounded by a thermal radiation shield, a thin thermal neutron absorber and a BeO reflector containing boron loaded control drums.

Koenig, D.R.

1976-01-01T23:59:59.000Z

62

Solar Heat-Pipe Receiver Wick Modeling  

DOE Green Energy (OSTI)

Stirling-cycle engines have been identified as a promising technology for the conversion of concentrated solar energy into usable electrical power. In previous experimented work, we have demonstrated that a heat pipe receiver can significantly improve system performance-over a directly-illuminated heater head. The design and operating conditions of a heat pipe receiver differ significantly from typical laboratory heat pipes. New wick structures have been developed to exploit the characteristics of the solar generation system. Typically, these wick structures allow vapor generation within the wick. Conventional heat pipe models do not handle this enhancement yet it can more than double the performance of the wick. In this study, I develop a steady-state model of a boiling-enhanced wick for a solar heat pipe receiver. The model is used for design-point calculations and is written in FORTRAN90. Some limited comparisons have been made with actual test data.

Andraka, C.E.

1998-12-21T23:59:59.000Z

63

Heat pipe reactors for space power applications  

SciTech Connect

A family of heat pipe reactors design concepts has been developed to provide heat to a variety of electrical conversion systems. Three power plants are described that span the power range 1-500 kW(e) and operate in the temperature range 1200 to 1700/sup 0/K. The reactors are fast, compact, heat-pipe cooled, high-temperature nuclear reactors fueled with fully enriched refractory fuels, UC-ZrC or UO/sub 2/. Each fuel element is cooled by an axially located molybdenum heat pipe containing either sodium or lithium vapor.

Koenig, D.R.; Ranken, W.A.; Salmi, E.W.

1977-01-01T23:59:59.000Z

64

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

65

Fast reactor power plant design having heat pipe heat exchanger  

DOE Patents (OSTI)

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

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

1984-08-30T23:59:59.000Z

66

Fast reactor power plant design having heat pipe heat exchanger  

DOE Patents (OSTI)

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

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

1985-01-01T23:59:59.000Z

67

Experimental study of the heat and mass transfer in a packed bed liquid desiccant air dehumidifier  

Science Conference Proceedings (OSTI)

Desiccant cooling systems have the ability to provide efficient humidity and temperature control while reducing the electrical energy requirement for air conditioning as compared to a conventional system. Naturally, the desiccant air dehumidification process greatly influences the overall performance of the desiccant system. Therefore, the effects of variables such as air and desiccant flow rates, air temperature and humidity, desiccant temperature and concentration, and the area available for heat and mass transfer are of great interest. Due to the complexity of the dehumidification process, theoretical modeling relies heavily upon experimental studies. However, a limited number of experimental studies are reported in the literature. This paper presents results from a detailed experimental investigation of the heat and mass transfer between a liquid desiccant (triethylene glycol) and air in a packed bed absorption tower using high liquid flow rates. A high performance packing that combines good heat and mass transfer characteristics with low pressure drop is used. The rate of dehumidification, as well as the effectiveness of the dehumidification process are assessed based on the variables listed above. Good agreement is shown to exist between the experimental findings and predictions from finite difference modeling. In addition, a comparison between the findings in the present study and findings previously reported in the literature is made. The results obtained from this study make it possible to characterize the important variables which impact the system design.

Oeberg, V.; Goswami, D.Y. [Univ. of Florida, Gainesville, FL (United States)

1998-11-01T23:59:59.000Z

68

Conceptual design of a heat pipe radiator  

SciTech Connect

A conceptual design of a waste heat radiator has been developed for a thermoelectric space nuclear power system. The basic shape of the heat pipe radiator was a frustum of a right circular cone. The design included stringer heat pipes to carry reject heat from the thermoelectric modules to the radiator skin that was composed of small-diameter, thin-walled cross heat pipes. The stringer heat pipes were armored to resist puncture by a meteoroid. The cross heat pipes were designed to provide the necessary unpunctured radiating area at the mission end with a minimum initial system mass. Several design cases were developed in which the individual stringer survival probabilities were varied and the radiator system mass was calculated. Results are presented for system mass as a function of individual stringer survival probability for six candidate container materials, three candidate heat pipe fluids, two radiator operating temperatures, two meteoroid shield types, and two radiating surface cases. Results are also presented for radiator reject heat as a function of system mass, area, and length for three system sizes.

Bennett, G.A.

1977-09-01T23:59:59.000Z

69

Heat pipe testing program test plan  

SciTech Connect

A test plan is given which describes the tests to be conducted on several typical solar receiver heat pipes. The hardware to be used, test fixtures and rationale of the test program are discussed. The program objective is to perform life testing under simulated receiver conditions, and to conduct performance tests with selected heat pipes to further map their performance, particularly with regard to their transient behavior. Performance requirements are defined. Test fixtures designed for the program are described in detail, and their capabilities for simulating the receiver conditions and their limitations are discussed. The heat pipe design is given. (LEW)

Bienert, W.B.

1980-03-14T23:59:59.000Z

70

Heat pipe effect in porous medium  

SciTech Connect

In this thesis a parametric study of the thermal and hydrologic characteristics of the fractured porous tuffs at Yucca Mountain, Nevada was conducted. The effects of different fracture and matrix properties including permeability, thermal conductivity, specific heat, porosity, and tortuosity on heat pipe performance in the vicinity of the waste package were observed. Computer simulations were carried out using TOUGH code on a Cray YMP-2 supercomputer. None of the fracture parameters affected the heat pipe performance except the mobility of the liquid in the fracture. Matrix permeability and thermal conductivity were found to have significant effect on the heat pipe performance. The effect of mass injection was studied for liquid water and air injected at the fracture boundary. A high rate of mass injection was required to produce any effect on the heat pipe. The fracture-matrix equilibrium is influenced by the matrix permeability and the matrix thermal conductivity.

Joseph, M.

1992-12-01T23:59:59.000Z

71

Modeling of pulsating heat pipes.  

SciTech Connect

This report summarizes the results of a computer model that describes the behavior of pulsating heat pipes (PHP). The purpose of the project was to develop a highly efficient (as compared to the heat transfer capability of solid copper) thermal groundplane (TGP) using silicon carbide (SiC) as the substrate material and water as the working fluid. The objective of this project is to develop a multi-physics model for this complex phenomenon to assist with an understanding of how PHPs operate and to be able to understand how various parameters (geometry, fill ratio, materials, working fluid, etc.) affect its performance. The physical processes describing a PHP are highly coupled. Understanding its operation is further complicated by the non-equilibrium nature of the interplay between evaporation/condensation, bubble growth and collapse or coalescence, and the coupled response of the multiphase fluid dynamics among the different channels. A comprehensive theory of operation and design tools for PHPs is still an unrealized task. In the following we first analyze, in some detail, a simple model that has been proposed to describe PHP behavior. Although it includes fundamental features of a PHP, it also makes some assumptions to keep the model tractable. In an effort to improve on current modeling practice, we constructed a model for a PHP using some unique features available in FLOW-3D, version 9.2-3 (Flow Science, 2007). We believe that this flow modeling software retains more of the salient features of a PHP and thus, provides a closer representation of its behavior.

Givler, Richard C.; Martinez, Mario J.

2009-08-01T23:59:59.000Z

72

Heat pipe dehumidification for supermarket energy savings  

E-Print Network (OSTI)

This thesis examines the possibility of using a heat pipe installed in the air conditioning unit of a supermarket to increase the level of dehumidification of the inside air. This dehumidification is expected to reduce the ...

Oliver, Eric M. (Eric Michael)

1994-01-01T23:59:59.000Z

73

New and Underutilized Technology: Wrap Around Heat Pipes  

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

The following information outlines key deployment considerations for wrap around heat pipes within the Federal sector.

74

Testing of a sodium heat pipe  

SciTech Connect

The operation of a heat pipe with both thermal radiation and convection heat rejection has been experimentally examined. The thermal radiation heat rejection conditions are similar to those which would be experienced in a space environment. The experimental results show good agreement with the analytical model. 3 refs., 2 figs.

Holtz, R.E.

1991-01-01T23:59:59.000Z

75

Silicon heat pipes for cooling electronics  

SciTech Connect

The increasing power density of integrated circuits (ICs) is creating the need for improvements in systems for transferring heat away from the chip. In earlier investigations, diamond films were used to conduct heat from ICs and spread the energy across a heat sink. The authors` investigation has indicated that a 635 {mu}m (25 mil) thick silicon substrate with embedded heat pipes could perform this task better than a diamond film. From their study, it appears that the development of a heat-pipe heat-spreading system is both technically and commercially feasible. The major challenge for this heat-spreading system is to develop an effective wick structure to transport liquid to the heated area beneath the chip. This paper discusses the crucial design parameters for this heat-pipe system, such as the required wick properties, the material compatibility issues, and the thermal characteristics of the system. The paper also provides results from some recent experimental activities at Sandia to develop these heat-pipe heat spreader systems.

Adkins, D.R.; Shen, D.S.; Palmer, D.W.; Tuck, M.R.

1994-12-31T23:59:59.000Z

76

Ceramic heat pipes for high temperature heat removal  

SciTech Connect

Difficulties in finding metal or protected metal components that exhibit both strength and corrosion resistance at high temperature have severely restricted the application of effective heat recovery techniques to process heat furnaces. A potential method of overcoming this restriction is to use heat pipes fabricated from ceramic materials to construct counterflow recuperators. A development program has been initiated to demonstrate the technical and eventually the economical feasibility of ceramic heat pipes and ceramic heat pipe recuperators. The prime candidate for heat pipe construction is SiC. Closed-end tubes of this material have been prepared by chemical vapor deposition (CVD). These tubes were lined internally with tungsten by a subsequent CVD operation, partially filled with sodium, and sealed by brazing a tungsten lined SiC plug into the open-end with a palladium--cobalt alloy. Heat pipes constructed in this manner have been successfully operated in vacuum at temperatures of 1225/sup 0/K and in air at a temperature of 1125/sup 0/K. The heat source used initially for the air testing was an induction heated metallic sleeve in thermal contact with the test unit. Subsequent testing has shown that a silicon carbide heat pipe can be successfully operated with natural gas burners providing the input heat. Methods of fabricating and testing these devices are described.

Keddy, E.S.; Ranken, W.A.

1978-01-01T23:59:59.000Z

77

Design and technology of heat pipes for cooling and heat exchange  

SciTech Connect

This new book presents a comprehensive account of heat pipe design, technology, and operation. It is based on insights and techniques developed by the author during more than twenty years of investigating high-performance heat pipe systems. The book provides information on a unique device with the capability to transport heat isothermally at high rates with no external power input. Emphasis is on high-performance liquid metal heat pipes, although nonliquid metal heat pipes are treated, as well. The first three chapters deal with the nonmathematical background for understanding heat pipe operation and heat transport capability. Remaining chapters detail heat pipe characteristics and design methods. Of special interest are simplified equations for obtaining heat pipe heat transport limits, heat pipe heat exchangers, heat pipe transient behavior, and inverted (nonwetting) heat pipes. Operational boundaries on heat pipe temperature and heat transport rate are described, and step-by-step procedures are given for involved calculations.

Silverstein, C.C.

1992-01-01T23:59:59.000Z

78

Neutron imaging of alkali metal heat pipes  

Science Conference Proceedings (OSTI)

High-temperature heat pipes are two-phase, capillary driven heat transfer devices capable of passively providing high thermal fluxes. Such a device using a liquid-metal coolant can be used as a solution for successful thermal management on hypersonic flight vehicles. Imaging of the liquid-metal coolant inside will provide valuable information in characterizing the detailed heat and mass transport. Neutron imaging possesses an inherent advantage from the fact that neutrons penetrate the heat pipe metal walls with very little attenuation, but are significantly attenuated by the liquid metal contained inside. Using the BT-2 beam line at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, preliminary efforts have been conducted on a nickel-sodium heat pipe. The contrast between the attenuated beam and the background is calculated to be approximately 3%. This low contrast requires sacrifice in spatial or temporal resolution so efforts have since been concentrated on lithium (Li) which has a substantially larger neutron attenuation cross section. Using the CG-1D beam line at the High Flux Isotope Reactor (HFIR) of Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, the first neutron images of high-temperature molybdenum (Mo)-Li heat pipes have been achieved. The relatively high neutron cross section of Li allows for the visualization of the Li working fluid inside the heat pipes. The evaporator region of a gravity assisted cylindrical heat pipe prototype 25 cm long was imaged from start-up to steady state operation up to approximately 900 C. In each corner of the square bore inside, the capillary action raises the Li meniscus above the bulk Li pool in the evaporator region. As the operational temperature changes, the meniscus shapes and the bulk meniscus height also changes. Furthermore, a three-dimensional tomographic image is also reconstructed from the total of 128 projection images taken 1.4o apart in which the Li had already cooled and solidified.

Kihm, Ken [University of Tennessee, Knoxville (UTK); Kirchoff, Eric [University of Tennessee, Knoxville (UTK); Golden, Matt [University of Tennessee, Knoxville (UTK); Rosenfeld, J. [Thermacore Inc.; Rawal, S. [Lockheed Martin Space Systems Company; Pratt, D. [United States Air Force Research Laboratory, Wright-Patterson Air Force Base; Bilheux, Hassina Z [ORNL; Walker, Lakeisha MH [ORNL; Voisin, Sophie [ORNL; Hussey, Dan [NIST Center for Neutron Research (NCRN), Gaithersburg, MD

2013-01-01T23:59:59.000Z

79

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

80

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

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

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

82

Assessment of dehumidifier geometries for desiccant cooling systems  

DOE Green Energy (OSTI)

Five dehumidifier designs are evaluated in this report - three from existing prototype cooling systems (from AiResearch, IGT, and IIT) and two (from UCLA and SERI) that have not yet been tested in a complete cooling system. The basic principles of heat and mass regenerators and the requirements of the solar cooling application have been combined to generate a list of desirable characteristics for dehumidifiers. The five designs are described and compared quantitatively; compared characteristics are related directly to the list of desirable characteristics. System performance is considered as well as isolated dehumidifier parameters. Preliminary simulations indicate that a system using the SERI dehumidifier design could achieve a design-point COP greater than unity without causing significant increases in parasitic power, system size, or system cost, compared with existing prototypes. Because of the high potential of the wound-ribbon design, it is recommended that a research program be carried out to fully characterize this type of dehumidifier.

Barlow, R.S.

1983-06-01T23:59:59.000Z

83

Experimental study of an advanced silica gel dehumidifier  

DOE Green Energy (OSTI)

This report contains results of work done to experimentally characterize the performance of an advanced, rotary, desiccant dehumidifier and to develop and validate analytical methods for evaluating its performance in air-conditioning systems. A facility, the Cyclic Test Facility, and a test and analysis procedure were developed to evaluate the performance of the dehumidifier. A series of tests was undertaken to understand the simultaneous heat- and mass-transfer processes. An advanced dehumidifier test article was tested under cyclic operation to fully characterize its performance. Brief accounts of this facility, with its hardware and instrumentation, and detailed accounts of the test data and data reduction and analysis methods are presented. The data provide an engineering data base for evaluating rotary dehumidifiers for cooling applications. The dehumidifier's performance, as measured by the effectiveness, agreed with theory to within plus or minus 10%. 16 refs., 16 figs., 1 tab.

Bharathan, D.; Parsons, J.M.; Maclaine-cross, I.L.

1987-11-01T23:59:59.000Z

84

A Temperature-Profile Method for Estimating Flow Processes in Geologic Heat Pipes  

E-Print Network (OSTI)

change and capillarity—the heat pipe effect, Int. J. Heatgeothermal reservoirs as heat pipes in fractured porousProcesses in Geologic Heat Pipes Jens T. Birkholzer Ernest

Birkholzer, Jens T.

2004-01-01T23:59:59.000Z

85

High temperature heat pipes for waste heat recovery  

SciTech Connect

Operation of heat pipes in air at temperatures above 1200/sup 0/K has been accomplished using SiC as a shell material and a chemical vapor deposit (CVD) tungsten inner liner for protection of the ceramic from the sodium working fluid. The CVD tungsten has been used as a distribution wick for the gravity assisted heat pipe through the development of a columnar tungsten surface structure, achieved by control of the metal vapor deposition rate. Wick performance has been demonstrated in tests at approximately 2 kW throughput with a 19-mm-i.d. SiC heat pipe. Operation of ceramic heat pipes in repeated start cycle tests has demonstrated their ability to withstand temperature rise rates of greater than 1.2 K/s.

Merrigan, M.A.; Keddy, E.S.

1980-01-01T23:59:59.000Z

86

Laboratory Performance Testing of Residential Dehumidifiers (Presentation)  

SciTech Connect

Six residential vapor compression cycle dehumidifiers spanning the available range of capacities and efficiencies were tested in the National Renewable Energy Laboratory's Heating, Ventilating, and Air-Conditioning Systems Laboratory. Each was tested under a wide range of indoor air conditions to facilitate the development of performance curves for use in whole-building simulation tools.

Winkler, J.

2012-03-01T23:59:59.000Z

87

High temperature heat pipe experiments in low earth orbit  

SciTech Connect

Although high temperature, liquid metal heat pipe radiators have become a standard component on most high power space power system designs, there is no experimental data on the operation of these heat pipes in a zero gravity or micro-gravity environment. Experiments to benchmark the transient and steady state performance of prototypical heat pipe space radiator elements are in preparation for testing in low earth orbit. It is anticipated that these heat pipes will be tested aborad the Space Shuttle in 1995. Three heat pipes will be tested in a cargo bay Get Away Special (GAS) canister. The heat pipes are SST/potassium, each with a different wick structure; homogeneous, arterial, and annular gap, the heat pipes have been designed, fabricated, and ground tested. In this paper, the heat pipe designs are specified, and transient and steady-state ground test data are presented.

Woloshun, K.; Merrigan, M.A.; Sena, J.T. (Los Alamos National Lab., NM (United States)); Critchley, E. (Phillips Lab., Kirtland AFB, NM (United States))

1993-01-01T23:59:59.000Z

88

High temperature heat pipe experiments in low earth orbit  

SciTech Connect

Although high temperature, liquid metal heat pipe radiators have become a standard component on most high power space power system designs, there is no experimental data on the operation of these heat pipes in a zero gravity or micro-gravity environment. Experiments to benchmark the transient and steady state performance of prototypical heat pipe space radiator elements are in preparation for testing in low earth orbit. It is anticipated that these heat pipes will be tested aborad the Space Shuttle in 1995. Three heat pipes will be tested in a cargo bay Get Away Special (GAS) canister. The heat pipes are SST/potassium, each with a different wick structure; homogeneous, arterial, and annular gap, the heat pipes have been designed, fabricated, and ground tested. In this paper, the heat pipe designs are specified, and transient and steady-state ground test data are presented.

Woloshun, K.; Merrigan, M.A.; Sena, J.T. [Los Alamos National Lab., NM (United States); Critchley, E. [Phillips Lab., Kirtland AFB, NM (United States)

1993-02-01T23:59:59.000Z

89

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

90

Heat pipe technology. Quarterly update, March 31, 1976  

SciTech Connect

Heat Pipe Technology is a continuing bibliographic summary of research on heat pipes. The first volume was published in the spring of 1971 and is cumulative through March of that year. The 1971, 1972, 1973 and 1974 Annual Supplements have been published and distributed. This update to Heat Pipe Technology cites the additional references identified during January, February and March of 1976. It is intended to provide ''current awareness'' to heat pipe researchers.

1976-01-01T23:59:59.000Z

91

Application of Heat Pipes to the ATSF Spacecraft  

SciTech Connect

The Applications Technology Satellite (ATS) heat pipe program is an extensive effort requiring the fabrication and testing of more than 300 flight qualified heat pipes. The spacecraft itself contains 55 heat pipes in three configurations and 13 sizes. The design selected for ATS was an axially groved 6061 aluminum-ammonia heat pipe. Several developmental programs and extensive testing, including individual heat pipes, heat pipes bonded into honeycomb panels, and a large number of life tests, were included within the overall effort. Results are presented for the thermal modeling of the heat pipes with the spacecraft. Results of thermal-vacuum testing of a thermal structural model and sounding rocket testing of the ATS axially grooved pipe are also discussed. Several problems including hydrogen gas generation, were encountered during the course of the program. The steps taken to solve these problems may be applicable to future programs.

Berger, M.E.; Kelly, W.H.

1973-01-01T23:59:59.000Z

92

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

93

Heat pipe technology development for high temperature space radiator applications  

SciTech Connect

Technology requirements for heat pipe radiators, potentially among the lightest weight systems for space power applications, include flexible elements, and improved specific radiator performance(kg/kW). For these applications a flexible heat pipe capable of continuous operation through an angle of 180/sup 0/ has been demonstrated. The effect of bend angle on the heat pipe temperature distribution is reviewed. An analysis of lightweight membrane heat pipe radiators that use surface tension forces for fluid containment has been conducted. The design analysis of these lightweight heat pipes is described and a potential application in heat rejection systems for space nuclear power plants outlined.

Merrigan, M.A.; Keddy, E.S.; Sena, J.T.; Elder, M.G.

1984-01-01T23:59:59.000Z

94

Experimental and computational studies of loop heat pipes.  

E-Print Network (OSTI)

??Computational and experimental investigations of fluid flow and heat transfer aspects of loop heat pipes (LHPs) are presented in this thesis. The overall goal is… (more)

Atabaki, Nima.

2006-01-01T23:59:59.000Z

95

Fabrication, Filling, Sealing and Testing of Micro Heat Pipes.  

E-Print Network (OSTI)

??Micro heat pipes are small and passive heat transfer devices. Research is going on in its applications ranging from using them in high powered electronic… (more)

NADGAUDA, OMKAR

2006-01-01T23:59:59.000Z

96

Performance predictions of silica-gel desiccant dehumidifiers  

DOE Green Energy (OSTI)

The analysis of a cross-cooled desiccant dehumidifier using silica gel in the form of sheets is described. This unit is the principal component of solar powered desiccant air conditioning system. The mathematical model has first been formulated describing the dynamics of the dehumidifier. The model leads to a system of nonlinear coupled heat and mass transfer equations for the sorption processes and linear heat transfer equations for the purging processes. The model accounts for the gas film resistance and for the moisture diffusion in the desiccant. The governing equations are solved by a finite difference scheme to obtain periodic steady state solutions. The accuracy of the theoretical predictions is ascertained by comparing them with the experimental results. The performance of the dehumidifier, for a chosen set of initial conditions and dehumidifier parameters, has also been given.

Mathiprakasam, B.; Lavan, Z.

1980-01-01T23:59:59.000Z

97

AWSWAH - the heat pipe solar water heater  

Science Conference Proceedings (OSTI)

An all weather heat pipe solar water heater (AWSWAH) comprising a collector of 4 m/sup 2/ (43 ft/sup 2/) and a low profile water tank of 160 liters (42 gal.) was developed. A single heat pipe consisting of 30 risers and two manifolds in the evaporator and a spiral condenser was incorporated into the AWSWAH. Condensate metering was done by synthetic fiber wicks. The AWSWAH was tested alongside two conventional solar water heaters of identical dimensions, an open loop system and a closed loop system. It was found that the AWSWAH was an average of 50% more effective than the open system in the temperature range 30-90 /sup 0/C (86-194 /sup 0/F). The closed loop system was the least efficient of the three systems.

Akyurt, M.

1986-01-01T23:59:59.000Z

98

Solid0Core Heat-Pipe Nuclear Batterly Type Reactor  

DOE Green Energy (OSTI)

This project was devoted to a preliminary assessment of the feasibility of designing an Encapsulated Nuclear Heat Source (ENHS) reactor to have a solid core from which heat is removed by liquid-metal heat pipes (HP).

Ehud Greenspan

2008-09-30T23:59:59.000Z

99

Review of liquid metal heat pipe work at Los Alamos  

SciTech Connect

A survey of space-power related liquid metal heat pipe work at Los Alamos National Laboratory is presented. Heat pipe development at Los Alamos has been on-going since 1963. Heat pipes were initially developed for thermionic nuclear-electrical power production in space. Since then Los Alamos has developed liquid metal heat pipes for numerous applications related to high temperature systems in both the space and terrestrial environments. Some of these applications include thermionic electrical generators, thermoelectric energy conversion (both in-core and direct radiation), thermal energy storage, hypersonic vehicle leading edge cooling, and heat pipe vapor laser cells. Some of the work performed at Los Alamos has been documented in internal reports that are often little-known. A representative description and summary of progress in space-related liquid metal heat pipe technology is provided followed by a reference section citing sources where these works may be found. 53 refs.

Reid, R.S.; Merrigan, M.A.; Sena, J.T.

1990-01-01T23:59:59.000Z

100

Heat pipe with improved wick structures  

DOE Patents (OSTI)

An improved planar heat pipe wick structure having projections formed by micromachining processes. The projections form arrays of interlocking, semi-closed structures with multiple flow paths on the substrate. The projections also include overhanging caps at their tops to increase the capillary pumping action of the wick structure. The capped projections can be formed in stacked layers. Another layer of smaller, more closely spaced projections without caps can also be formed on the substrate in between the capped projections. Inexpensive materials such as Kovar can be used as substrates, and the projections can be formed by electrodepositing nickel through photoresist masks.

Benson, David A. (Albuquerque, NM); Robino, Charles V. (Albuquerque, NM); Palmer, David W. (Albuquerque, NM); Kravitz, Stanley H. (Placitas, NM)

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Waste heat recovery system having thermal sleeve support for heat pipe  

SciTech Connect

A system for recovering waste heat from a stream of heated gas is disclosed. The system includes a convection heat transfer chamber, a boiler tank, and a plurality of heat pipes thermally interconnecting the convection heat transfer chamber with the boiler tank. Each of the heat pipes includes an evaporator section which is disposed in heat transfer relation with a stream of heated gas flowing through the convection heat transfer chamber, and a condenser section disposed in heat transfer relation with a volume of water contained within the boiler tank. The boiler tank is provided with a header plate having an array of heat pipe openings through which the heat pipes project. A heat pipe support sleeve is received in each heat pipe opening in sealed engagement with the header plate, with the heat pipes projecting through the support sleeves and thermally interconnecting the convection heat transfer chamber with the boiler tank. An intermediate portion of each heat pipe is received in sealed engagement with its associated support sleeve. In a preferred embodiment, heat transfer through the support sleeve is minimized in an arrangement in which each heat pipe opening is reduced by a stepped bore with the support sleeve connected in threaded, sealed engagement with the stepped bore. Futhermore, in this arrangement, the support sleeve has swaged end portions which project beyond the header plate and engage the heat pipe on opposite sides at points which are remote with respect to the support sleeve/header plate interface. One of the swages end portions is sealed against the heat pipe in a fluid-tight union within the boiler tank. The support sleeve is radially spaced with respect to the heat pipe, and is also radially spaced with respect to the heat pipe opening whereby heat transfer through the walls of the heat pipe to the support sleeve and to the header plate is minimized by concentric annular air gaps.

McCurley, J.

1984-01-24T23:59:59.000Z

102

Waste heat recovery system having thermal sleeve support for heat pipe  

SciTech Connect

A system for recovering waste heat from a stream of heated gas is disclosed. The system includes a convection heat transfer chamber, a boiler tank, and a plurality of heat pipes thermally interconnecting the convection heat transfer chamber with the boiler tank. Each of the heat pipes includes an evaporator section which is disposed in heat transfer relation with a stream of heated gas flowing through the convection heat transfer chamber, and a condenser section disposed in heat transfer relation with a volume of water contained within the boiler tank. The boiler tank is provided with a header plate having an array of heat pipe openings through which the heat pipes project. A heat pipe support sleeve is received in each heat pipe opening in sealed engagement with the header plate, with the heat pipes projecting through the support sleeves and thermally interconnecting the convection heat transfer chamber with the boiler tank. An intermediate portion of each heat pipe is received in sealed engagement with its associated support sleeve. In a preferred embodiment, heat transfer through the support sleeve is minimized in an arrangement in which each heat pipe opening is reduced by a stepped bore with the support sleeve connected in threaded, sealed engagement with the stepped bore. Furthermore, in this arrangement, the support sleeve has swaged end portions which project beyond the header plate and engage the heat pipe on opposite sides at points which are remote with respect to the support sleeve/header plate interface. One of the swaged end portions is sealed against the heat pipe in a fluid-tight union within the boiler tank. The support sleeve is radially spaced with respect to the heat pipe, and is also radially spaced with respect to the heat pipe opening whereby heat transfer through the walls of the heat pipe to the support sleeve and to the header plate is minimized by concentric annular air gaps.

McCurley, J.

1984-04-10T23:59:59.000Z

103

Waste heat recovery system having thermal sleeve support for heat pipe  

SciTech Connect

A system for recovering waste heat from a stream of heated gas is disclosed. The system includes a convection heat transfer chamber, a boiler tank, and a plurality of heat pipes thermally interconnecting the convection heat transfer chamber with the boiler tank. Each of the heat pipes includes an evaporator section which is disposed in heat transfer relation with a stream of heated gas flowing through the convection heat transfer chamber, and a condenser section disposed in heat transfer relation with a volume of water contained within the boiler tank. The boiler tank is provided with a header plate having an array of heat pipe openings through which the heat pipes project. A heat pipe support sleeve is received in each heat pipe opening in sealed engagement with the header plate, with the heat pipes projecting through the support sleeves and thermally interconnecting the convection heat transfer chamber with the boiler tank. An intermediate portion of each heat pipe is received in sealed engagement with its associated support sleeve. In a preferred embodiment, heat transfer through the support sleeve is minimized in an arrangement in which each heat pipe opening is reduced by a stepped bore with the support sleeve connected in threaded, sealed engagement with the stepped bore. Furthermore, in this arrangement, the support sleeve has swaged end portions which project beyond the header plate and engage the heat pipe on opposite sides at points which are remote with respect to the support sleeve/header plate interface. One of the swaged end portions is sealed against the heat pipe in a fluid-tight union within the boiler tank. The support sleeve is radially spaced with respect to the heat pipe and is also radially spaced with respect to the heat pipe opening whereby heat transfer through the walls of the heat pipe to the support sleeve and to the header plate is minimized by concentric annular air gaps.

McCurley, J.

1984-12-04T23:59:59.000Z

104

Sodium and lithium corrosion in molybdenum heat pipes  

SciTech Connect

Sodium and lithium corrosin in molybdenum heat pipes has been shown to be impurity dependent rather than solubility dependent. Impurities represent the major contributors to corrosion in the heat pipes tested. Our experiments have shown no evidence of direct solution of molybdenum by either sodium or lithium. Analysis has suggested that a critical concentration of impurities is required to initiate corrosion. Thus it appears that corrosion in Mo/Na and Mo/Li heat pipes can be controlled if impurity concentration can be limited by removal of impurities from the working fluid and heat pipe components prior to operation or by internal gettering during operation.

Lundberg, L.B.; Merrigan, M.A.

1984-01-01T23:59:59.000Z

105

Magnetohydrodynamic power generation, electromagnetic pumps, heat pipes, and thermionic convertors  

DOE Green Energy (OSTI)

The basic principles of operation, components, and design of MHD generators, electromagnetic pumps, heat pipes and thermionic converters are described. 66 references. (WHK)

Pierson, E.S.; Bonyhady, K.A.; Dunn, P.F.; Nathenson, R.D.; Uherka, K.L.

1984-01-01T23:59:59.000Z

106

Heat pipe cooling for scramjet engines. Final report  

Science Conference Proceedings (OSTI)

Liquid metal heat pipe cooling systems have been investigated for the combustor liner and engine inlet leading edges of scramjet engines for a missile application. The combustor liner is cooled by a lithium-TZM molybdenum annular heat pipe, which incorporates a separate lithium reservoir. Heat is initially absorbed by the sensible thermal capacity of the heat pipe and liner, and subsequently by the vaporization and discharge of lithium to the atmosphere. The combustor liner temperature is maintained at 3400 F or less during steady-state cruise. The engine inlet leading edge is fabricated as a sodium-superalloy heat pipe. Cooling is accomplished by radiation of heat from the aft surface of the leading edge to the atmosphere. The leading edge temperature is limited to 1700 F or less. It is concluded that heat pipe cooling is a viable method for limiting scramjet combustor liner and engine inlet temperatures to levels at which structural integrity is greatly enhanced.

Silverstein, C.C.

1986-12-01T23:59:59.000Z

107

Glass-heat-pipe evacuated-tube solar collector  

DOE Patents (OSTI)

A glass heat pipe is adapted for use as a solar energy absorber in an evacuated tube solar collector and for transferring the absorbed solar energy to a working fluid medium or heat sink for storage or practical use. A capillary wick is formed of granular glass particles fused together by heat on the inside surface of the heat pipe with a water glass binder solution to enhance capillary drive distribution of the thermal transfer fluid in the heat pipe throughout the entire inside surface of the evaporator portion of the heat pipe. Selective coatings are used on the heat pipe surface to maximize solar absorption and minimize energy radiation, and the glass wick can alternatively be fabricated with granular particles of black glass or obsidian.

McConnell, R.D.; VanSant, J.H.

1981-08-06T23:59:59.000Z

108

The Economics of Steam Vs. Electric Pipe Heating  

E-Print Network (OSTI)

To properly design a pipe heating system, the basic principles of heat transfer from an insulated pipe must be understood. The three methods of heat flow are conduction, convection (both forced and natural) and radiation. The total heat loss from a pipe must be determined first, since this is the heat which must be replaced to maintain a pipe at a given temperature. A steam heating system requires an analysis of the heat loss from the pipe as well as an analysis of the capacity of the heating system. The economics of steam heat include the accessories as well as the inefficiencies of steam heat. The design of an electric heating system normally involves far fewer components and engineering complexities than does a comparable steam system. The basic system is comprised of the heater, controls and connection accessories. Today there are several economic trade-offs to be made in selecting a pipe heating system. These involve engineering and design costs, maintenance costs, installation costs and energy costs. The economic trade-offs to be made in selecting a pipe heating system do not universally favor one system over another for all cases.

Schilling, R. E.

1985-05-01T23:59:59.000Z

109

Waste heat recovery system having thermal sleeve support for heat pipe  

SciTech Connect

A system for recovering waste heat from a stream of heated gas is disclosed. The system includes a convection heat transfer chamber, a boiler tank, and a plurality of heat pipes thermally interconnecting the convection heat transfer chamber with the boiler tank. Each of the heat pipes includes an evaporator section which is disposed in heat transfer relation with a stream of heated gas flowing through the convection heat transfer chamber, and a condenser section disposed in heat transfer relation with a volume of water contained within the boiler tank. The boiler tank is provided with a header plate having an array of heat pipe openings through which the heat pipes project. A heat support sleeve is received in each heat pipe opening in sealed engagement with the header plate, with the heat pipes projecting through the support sleeves and thermally interconnecting the convection heat transfer chamber with the boiler tank. An intermediate portion of each heat pipe is received in sealed engagement with its associated support sleeve. In a preferred embodiment, heat transfer through the support sleeve is minimized in an arrangement in which each heat pipe opening is reduced by a stepped bore with the support sleeve connected in threaded, sealed engagement with the stepped bore. Furthermore, in this arrangement, the support sleeve has swaged end portions which project beyond the header plate and engage the heat pipe on opposite sides at points which are remote with respect to the support sleeve/header plate interface. One of the swaged end portions is sealed against the heat pipe in a fluid-tight union within the boiler tank. The support sleeve is radially spaced with respect to the heat pipe, and is also radially spaced with respect to the heat pipe opening whereby heat transfer through the walls of the heat pipe to the support sleeve and to the header plate is minimized by concentric annular air gaps.

McCurley, J.

1984-12-18T23:59:59.000Z

110

Performance correlations for high temperature potassium heat pipes  

SciTech Connect

Potassium heat pipes designed for operation at a nominal temperature of 775K have been developed for use in a heat pipe cooled reactor design. The heat pipes operate in a gravity assist mode with a maximum required power throughput of approximately 16 kW per heat pipe. Based on a series of sub-scale experiments with 2.12 and 3.2 cm diameter heat pipes the prototypic heat pipe diameter was set at 5.7 cm with a simple knurled wall wick used in the interests of mechanical simplicity. The performance levels required for this design had been demonstrated in prior work with gutter assisted wicks and emphasis in the present work was on the attainment of similar performance with a simplified wick structure. The wick structure used in the experiment consisted of a pattern of knurled grooves in the internal wall of the heat pipe. The knurl depth required for the planned heat pipe performance was determined by scaling of wick characteristic data from the sub-scale tests. These tests indicated that the maximum performance limits of the test heat pipes did not follow normal entrainment limit predictions for textured wall gravity assist heat pipes. Test data was therefore scaled to the prototype design based on the assumption that the performance was controlled by an entrainment parameter based on the liquid flow depth in the groove structure. This correlation provided a reasonable fit to the sub-scale test data and was used in scale up of the design from the 8.0 cm/sup 2/ cross section of the largest sub-scale heat pipe to the 25.5 cm/sup 2/ cross section prototype. Correlation of the model predictions with test data from the prototype is discussed.

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

1987-01-01T23:59:59.000Z

111

Experimental Investigation of the Padding Tower for Air Dehumidifier  

E-Print Network (OSTI)

Air conditioning with all fresh air is founded on the principle of dehumidifying by liquid desiccant. It has the characteristics of being clean, power-saving, easy to operate, and requiring low-grade heat. It is suitable for applying waste heat, and solar power as the heat source for regeneration. Hence, this system has a great latent potential for energy savings and environmental protection. The system chooses the padding tower as a dehumidifier and regenerator, which are often used in petrochemical industry. The system chooses a padding tower as a dehumidifier, and LiCl-Water as a liquid desiccant. The vapor in the air is absorbed by the spray of the LiCl solution, and then the absorbed vapor will be released by heating the absorbent. These processes form the circle of absorptive refrigeration operating in atmospheric pressure. This paper describes studies on the theory and experiment of the padding tower of the dehumidifying air conditioning, including selecting different padding and measuring the speed of the air flow and the solution flow and the pressure drop between the layers of the padding. The experimental and computational results indicate that the design parameters of the padding tower significantly influence the characteristics of the liquid desiccant air conditioning. Of these design parameters, the framework of the padding tower, ratio of the air and the concentration of the inlet solution is largest through the tower, the temperature and effects of the dehumidifying capability of the tower.

Wang, J.; Liu, J.; Li, C.; Zhang, G.; An, S.

2006-01-01T23:59:59.000Z

112

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

113

Long titanium heat pipes for high-temperature space radiators  

SciTech Connect

Titanium heat pipes are being developed to provide light weight, reliable heat rejection devices as an alternate radiator design for the Space Reactor Power System (SP-100). The radiator design includes 360 heat pipes, each of which is 5.2 m long and dissipates 3 kW of power at 775 K. The radiator heat pipes use potassium as the working fluid, have two screen arteries for fluid return, a roughened surface distributive wicking system, and a D-shaped cross-section container configuration. A prototype titanium heat pipe, 5.5-m long, has been fabricated and tested in space-simulating conditions. Results from startup and isothermal operation tests are presented. These results are also compared to theoretical performance predictions that were used to design the heat pipe initially.

Girrens, S.P.; Ernst, D.M.

1982-01-01T23:59:59.000Z

114

Flow modification in McGill Heat Pipes.  

E-Print Network (OSTI)

??A heat pipe is a heat transfer device of very high thermal conductance that features two-phase flow. Research at McGill University has led to the… (more)

Lee, JuHee, 1973-

2005-01-01T23:59:59.000Z

115

Analysis of the transient compressible vapor flow in heat pipe  

SciTech Connect

The transient compressible one-dimensional vapor flow dynamics in a heat pipe is modeled. The numerical results are obtained by using the implicit non-iterative Beam-Warming finite difference method. The model is tested for simulated heat pipe vapor flow and actual vapor flow in cylindrical heat pipes. A good comparison of the present transient results for the simulated heat pipe vapor flow with the previous results of a two-dimensional numerical model is achieved and the steady state results are in agreement with the existing experimental data. The transient behavior of the vapor flow under subsonic, sonic, and supersonic speeds and high mass flow rates are successfully predicted. The one-dimensional model also describes the vapor flow dynamics in cylindrical heat pipes at high temperatures.

Jang, J.H.; Faghri, A. [Wright State Univ., Dayton, OH (United States); Chang, W.S. [Wright Research and Development Center, Wright-Patterson, OH (United States)

1989-07-01T23:59:59.000Z

116

Comparison of heat transfer in solar collectors with heat pipe versus flow through absorbers  

DOE Green Energy (OSTI)

Analysis of heat transfer in solar collectors with heat pipe absorbers is compared to that for collectors with flow through absorbers. Both pumped and thermosiphon systems that produce hot water or other heated fluids are discussed. In these applications the heat pipe absorber suffers a heat transfer penalty compared with the flow through absorber, but in many cases the penalty can be minimized by proper design at the heat pipe condenser and system manifold. When the solar collector is used to drive an absorption chiller, the heat pipe absorber has better heat transfer characteristics than the flow through absorber.

Hull, J.R.

1985-01-01T23:59:59.000Z

117

Latent Heat Thermal Energy Storage with Embedded Heat Pipes for Concentrating Solar Power Applications.  

E-Print Network (OSTI)

?? An innovative, novel concept of combining heat pipes with latent heat thermal energy storage (LHTES) for concentrating solar power (CSP) applications is explored. The… (more)

Robak, Christopher

2012-01-01T23:59:59.000Z

118

Factors affecting oscillating motion and heat transfer in an oscillating heat pipe .  

E-Print Network (OSTI)

??As demand has grown for thermal management solutions, interest in passive heat transfer devices such as heat pipes has grown as well. In particular, oscillating… (more)

Smoot, Christopher

2013-01-01T23:59:59.000Z

119

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

120

Low Cost High Performance Generator Technology Program. Volume 5. Heat pipe topical, appendices  

SciTech Connect

Work performed by Dynatherm Corporation for Teledyne Isotopes during a program entitled ''Heat Pipe Fabrication, Associated Technical Support and Reporting'' is reported. The program was initiated on November 29, 1972; the main objectives were accomplished with the delivery of the heat pipes for the HPG. Life testing of selected heat pipe specimens is continuing to and beyond the present date. The program consisted of the following tasks: Heat Pipe Development of Process Definition; Prototype Heat Pipes for Fin Segment Test; HPG Heat Pipe Fabrication and Testing; Controlled Heat Pipe Life Test; and Heat Pipe Film Coefficient Determination. (TFD)

1975-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Low Cost High Performance Generator Technology Program. Volume 5. Heat pipe topical, appendices  

DOE Green Energy (OSTI)

Work performed by Dynatherm Corporation for Teledyne Isotopes during a program entitled ''Heat Pipe Fabrication, Associated Technical Support and Reporting'' is reported. The program was initiated on November 29, 1972; the main objectives were accomplished with the delivery of the heat pipes for the HPG. Life testing of selected heat pipe specimens is continuing to and beyond the present date. The program consisted of the following tasks: Heat Pipe Development of Process Definition; Prototype Heat Pipes for Fin Segment Test; HPG Heat Pipe Fabrication and Testing; Controlled Heat Pipe Life Test; and Heat Pipe Film Coefficient Determination. (TFD)

Not Available

1975-07-01T23:59:59.000Z

122

Transient performance investigation of a space power system heat pipe  

SciTech Connect

Start-up, shut-down, and peak power tests have been conducted with a molybdenum-lithium heat pipe at temperatures to 1500 K. The heat pipe was radiation coupled to a water cooled calorimeter for the tests with rf induction heating used for the input to the evaporator region. Maximum power throughput in the tests was 36.8 kw corresponding to a power density of 23 kw/cm/sup 2/ for the 1.4 cm diameter vapor space of the annular wick heat pipe. The corresponding evaporator flux density was approximately 150 w/cm/sup 2/ over an evaporator length of 40 cm at peak power. Condenser length for the tests was approximately 3.0 m. A variable geometry radiation shield was used to vary the load on the heat pipe during the tests. Results of the tests showed that liquid depletion in the evaporator region of the heat pipe could occur in shut-down and prevent restart of the heat pipe. Changes in surface emissivity of the heat pipe condenser surface were shown to affect the shut-down and re-start limits. 12 figs.

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

1986-01-01T23:59:59.000Z

123

Membrane heat pipe development for space radiator applications  

SciTech Connect

A self-deploying membrane heat pipe (SMHP) is being designed and fabricated to operate in an in-cabin experiment aboard a STS flight. The heat pipe comprises a mylar membrane with a woven fabric arterial wick and R-11 as the working fluid. Preliminary results indicate that this SMHP design will successfully expand and retract in response to an applied heat load; the retraction force is provided by a constant force spring.

Woloshun, K.; Merrigan, M.

1986-01-01T23:59:59.000Z

124

Commercial high efficiency dehumidification systems using heat pipes  

SciTech Connect

An improved heat pipe design using separately connected two-section one-way flow heat pipes with internal microgrooves instead of wicks is described. This design is now commercially available for use to increase the dehumidification capacity of air conditioning systems. The design also includes a method of introducing fresh air into buildings while recovering heat and controlling the humidity of the incoming air. Included are applications and case studies, load calculations and technical data, and installation, operation, and maintenance information.

1993-09-01T23:59:59.000Z

125

Performance characteristics of gravity-assisted, potassium heat pipes  

SciTech Connect

Experiments with potassium-stainless steel gravity-assisted heat pipes were performed. Performance limitations due to entrainment or flooding of the liquid return flow are compared with analytical model predictions. The effect of heated pool height was investigated and problems with surface wetting are discussed. A comparison between entrainment limits for smooth-walled and textured-walled heat pipes was made and a minimum internal surface texturing depth is suggested.

Prenger, F.C.; Keddy, E.S.; Sena, J.T.

1985-01-01T23:59:59.000Z

126

Investigation of the heat pipe arrays for convective electronic cooling  

E-Print Network (OSTI)

A combined experimental and analytical investigation was conducted to evaluate a heat pipe convective cooling device consisting of sixteen small copper/water heat pipes mounted vertically in a 4x4 array 25.4 mm square. The analytical portion of the investigation focused on determination of the maximum heat transport capacity and the resistance of the individual heat pipes. The resistance of each beat pipe was found to be 2.51 K/Watt, or more than 3 times smaller than the resistance produced by a solid copper rod with the same dimensions. The maximum predicted heat rejection for the module was over 50 Watts, or a power density in excess of 7.75 Watts/CM2. In the experimental portion of the investigation, two different modules were tested. The first module utilized ten circular aluminum fins mounted on the condenser end of each heat pipe to enhance heat rejection, while the second contained only the sixteen copper/water heat pipes. The effects of flow velocity, input power, and base plate temperature on the overall thermal resistance and the heat rejection capacity were determined, as well as the pressure drop resulting from each module. The finned heat pipe array was found to have a lower overall thermal resistance and thus, a higher heat rejection capacity, but also resulted in a significantly larger pressure drop than the array without fins. The results of the heat pipe array experiments were also compared with experimental and empirical results obtained from flow over a flat plate 25.4 mm square.

Howard, Alicia Ann Harris

1993-01-01T23:59:59.000Z

127

Vibration test plan for a space station heat pipe subassembly  

SciTech Connect

This test plan describes the Sundstrand portion of task two of Los Alamos National Laboratory (LANL) contract 9-x6H-8102L-1. Sundstrand Energy Systems was awarded a contract to investigate the performance capabilities of a potassium liquid metal heat pipe as applied to the Organic Rankine Cycle (ORC) solar dynamic power system for the Space Station. The test objective is to expose the heat pipe subassembly to the random vibration environment which simulates the space shuttle launch condition. The results of the test will then be used to modify as required future designs of the heat pipe.

Parekh, M.B. [Sundstrand Energy Systems, Rockford, IL (United States)

1987-09-29T23:59:59.000Z

128

Numerical analysis of vapor flow in a micro heat pipe  

E-Print Network (OSTI)

The vapor flow in a flat plate micro heat pipe with both uniform and linear heat flux boundary conditions has been numerically analyzed. For both types of boundary conditions, the Navier-Stokes equations with steady incompressible two-dimensional flow were solved using the SIMPLE method. The results indicate that the pressure, shear stress, and friction factor under linear heat flux boundary conditions are considerably smoother, and hence, more closely approximate the real situation. As the heat flux increases, the pressure drop increases, but the friction factor demonstrates only a slight change for different heat flux conditions. The size and shape of the micro heat pipe vapor space was shown to have a significant influence on the vapor flow behavior for micro heat pipes. When the vapor space area decreases, the pressure drop, shear stress, and friction factor all significantly increase.

Liu, Xiaoqin

1996-01-01T23:59:59.000Z

129

NASA Lewis steady-state heat pipe code users manual  

SciTech Connect

The NASA Lewis heat pipe code has been developed to predict the performance of heat pipes in the steady state. The code can be used as a design tool on a personal computer or, with a suitable calling routine, as a subroutine for a mainframe radiator code. A variety of wick structures, including a user input option, can be used. Heat pipes with multiple evaporators, condensers, and adiabatic sections in series and with wick structures that differ among sections can be modeled. Several working fluids can be chosen, including potassium, sodium, and lithium, for which the monomer-dimer equilibrium is considered. The code incorporates a vapor flow algorithm that treats compressibility and axially varying heat input. This code facilitates the determination of heat pipe operating temperatures and heat pipe limits that may be encountered at the specified heat input and environment temperature. Data are input to the computer through a user-interactive input subroutine. Output, such as liquid and vapor pressures and temperatures, is printed at equally spaced axial positions along the pipe as determined by the user.

Tower, L.K. [Sverdrup Technology, Inc., Brook Park, OH (United States). Lewis Research Center Group; Baker, K.W. [National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center; Marks, T.S. [Oregon State Univ., Corvallis, OR (United States)

1992-06-01T23:59:59.000Z

130

An investigation of corrosion in liquid-metal heat pipes  

DOE Green Energy (OSTI)

Research is underway to develop a 75-kW heat pipe to transfer solar energy from the focus of a parabolic dish concentrator to the heater tubes of a Stirling engine. The high flux levels and high total power level encountered in this application have made it necessary to use a high-performance wick structure with fibers on the order of 4 to 8 microns in diameter. This fine wick structure is highly susceptible to corrosion damage and plugging, as dissolved contaminants plate out on the evaporator surface. Normal operation of the heat pipe also tends to concentrate contaminants in localized areas of the evaporator surface where heat fluxes are the highest. Sandia National Laboratories is conducting a systematic study to identify procedures that reduce corrosion and contamination problems in liquid-metal heat pipes. A series of heat pipes are being tested to explore different options for cleaning heat-pipe systems. Models are being developed to help understand the overall importance of operating parameters on the life of heat-pipe systems. In this paper, the authors present their efforts to reduce corrosion damage.

Adkins, D.R.; Rawlinson, K.S.; Andraka, C.E.; Showalter, S.K.; Moreno, J.B.; Moss, T.A.; Cordiero, P.G.

1998-08-01T23:59:59.000Z

131

Heat pipe thermal control of slender optics probes  

SciTech Connect

The thermal design for a stereographic viewing system is presented. The design incorporates an annular heat pipe and thermal isolation techniques. Test results are compared with design predictions for a prototype configuration. Test data obtained during heat pipe startup showing temperature gradients along the evaporator wall are presented. Correlations relating maximum wall temperature differences to a liquid Reynolds number were obtained at low power levels. These results are compared with Nusselt's Falling Film theory.

Prenger, F.C.

1979-01-01T23:59:59.000Z

132

Heat pipe radiation cooling evaluation: Task 2 concept studies report  

SciTech Connect

This report presents the result of Task 2, Concept Studies for Heat Pipe Radiation Cooling (HPRC), which was performed for Los Alamos National Laboratory under Contract 9-XT1-U9567. Studies under a prior contract defined a reference HPRC conceptual design for hypersonic aircraft engines operating at Mach 5 and an altitude of 80,000 ft. Task 2 involves the further investigation of heat pipe radiation cooling (HPRC) systems for additional design and operating conditions.

Silverstein, C.C.

1991-10-01T23:59:59.000Z

133

Heat pipe cooling system for underground, radioactive waste storage tanks  

SciTech Connect

An array of 37 heat pipes inserted through the central hole at the top of a radioactive waste storage tank will remove 100,000 Btu/h with a heat sink of 70/sup 0/F atmospheric air. Heat transfer inside the tank to the heat pipe is by natural convection. Heat rejection to outside air utilizes a blower to force air past the heat pipe condenser. The heat pipe evaporator section is axially finned, and is constructed of stainless steel. The working fluid is ammonia. The finned pipes are individually shrouded and extend 35 ft down into the tank air space. The hot tank air enters the shroud at the top of the tank and flows downward as it is cooled, with the resulting increased density furnishing the pressure difference for circulation. The cooled air discharges at the center of the tank above the sludge surface, flows radially outward, and picks up heat from the radioactive sludge. At the tank wall the heated air rises and then flows inward to comple the cycle.

Cooper, K.C.; Prenger, F.C.

1980-02-01T23:59:59.000Z

134

Evaluation of Using Infrared Thermography for quantifying Heat Losses From Buried Heat Distribution Pipes in chicago Housing Authority's Projects  

Science Conference Proceedings (OSTI)

Evaluation of using infrared thermography for quantifying heat losses from buried heat distribution pipes in Chicago Housing Authority's Projects

Gary Phetteplace

2001-05-29T23:59:59.000Z

135

Coupled Reactor Kinetics and Heat Transfer Model for Heat Pipe Cooled Reactors  

SciTech Connect

Heat pipes are often proposed as cooling system components for small fission reactors. SAFE-300 and STAR-C are two reactor concepts that use heat pipes as an integral part of the cooling system. Heat pipes have been used in reactors to cool components within radiation tests (Deverall, 1973); however, no reactor has been built or tested that uses heat pipes solely as the primary cooling system. Heat pipe cooled reactors will likely require the development of a test reactor to determine the main differences in operational behavior from forced cooled reactors. The purpose of this paper is to describe the results of a systems code capable of modeling the coupling between the reactor kinetics and heat pipe controlled heat transport. Heat transport in heat pipe reactors is complex and highly system dependent. Nevertheless, in general terms it relies on heat flowing from the fuel pins through the heat pipe, to the heat exchanger, and then ultimately into the power conversion system and heat sink. A system model is described that is capable of modeling coupled reactor kinetics phenomena, heat transfer dynamics within the fuel pins, and the transient behavior of heat pipes (including the melting of the working fluid). The paper focuses primarily on the coupling effects caused by reactor feedback and compares the observations with forced cooled reactors. A number of reactor startup transients have been modeled, and issues such as power peaking, and power-to-flow mismatches, and loading transients were examined, including the possibility of heat flow from the heat exchanger back into the reactor. This system model is envisioned as a tool to be used for screening various heat pipe cooled reactor concepts, for designing and developing test facility requirements, for use in safety evaluations, and for developing test criteria for in-pile and out-of-pile test facilities.

WRIGHT,STEVEN A.; HOUTS,MICHAEL

2000-11-22T23:59:59.000Z

136

Random Analysis on Line-Heat Source Temperature Field of Ground Source Heat Pumps Buried Pipes  

Science Conference Proceedings (OSTI)

In this paper the random properties of ground-source heat pump (GSHP) system.GSHP buried pipe to Kelvin one-dimensional line source of heat transfer model are discussed. The model randomness is analyzed, and the GSHP buried pipe to random excess temperature ... Keywords: GSHP, Buriedpipe, Line-heat source, Temperature field, Correlation

Changsheng Guan; Zhuodong Liu; Kai Xia; Xuyi Chen

2009-05-01T23:59:59.000Z

137

Impacts of Soil and Pipe Thermal Conductivity on Performance of Horizontal Pipe in a Ground-source Heat Pump  

E-Print Network (OSTI)

In this paper the composition and thermal property of soil are discussed. The main factors that impact the soil thermal conductivity and several commonly-used pipe materials are studied. A model of heat exchanger with horizontal pipes of ground-source heat pump is developed. The impact of soil thermal conductivity and pipe thermal conductivity on the soil temperature field around the buried pipe, and the thermal performance of the heat exchanger are simulated. The simulation results show that with the increase of soil thermal conductivity, heat transfer quantity obviously increases, and the temperature of soil around pipe decrease under winter conditions. The temperature field varies relatively faster with thermal conductivity in the site nearer to the buried pipe. With the increase of pipe thermal conductivity, heat transfer quantity and the mean temperature of the buried pipe's outside surface all increase.

Song, Y.; Yao, Y.; Na, W.

2006-01-01T23:59:59.000Z

138

Building Technologies Office: Residential Dishwashers, Dehumidifiers, and  

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

Residential Residential Dishwashers, Dehumidifiers, and Cooking Products, and Commercial Clothes Washers ANOPR Public Meeting to someone by E-mail Share Building Technologies Office: Residential Dishwashers, Dehumidifiers, and Cooking Products, and Commercial Clothes Washers ANOPR Public Meeting on Facebook Tweet about Building Technologies Office: Residential Dishwashers, Dehumidifiers, and Cooking Products, and Commercial Clothes Washers ANOPR Public Meeting on Twitter Bookmark Building Technologies Office: Residential Dishwashers, Dehumidifiers, and Cooking Products, and Commercial Clothes Washers ANOPR Public Meeting on Google Bookmark Building Technologies Office: Residential Dishwashers, Dehumidifiers, and Cooking Products, and Commercial Clothes Washers ANOPR

139

Testing of Stirling engine solar reflux heat-pipe receivers  

DOE Green Energy (OSTI)

Alkali metal heat-pipe receivers have been identified as a desirable interface to couple a Stirling-cycle engine with a parabolic dish solar concentrator. The reflux receiver provides power nearly isothermally to the engine heater heads while de-coupling the heater head design from the solar absorber surface design. The independent design of the receiver and engine heater head leads to high system efficiency. Heat pipe reflux receivers have been demonstrated at approximately 30 kW{sub t} power throughput by others. This size is suitable fm engine output powers up to 10 kW{sub e}. Several 25-kW{sub e}, Stirling-cycle engines exist, as well as designs for 75-kW{sub t} parabolic dish solar concentrators. The extension of heat pipe technology from 30 kW{sub t} to 75 kW{sub t} is not trivial. Heat pipe designs are pushed to their limits, and it is critical to understand the flux profiles expected from the dish, and the local performance of the wick structure. Sandia has developed instrumentation to monitor and control the operation of heat pipe reflux receivers to test their throughput limits, and analytical models to evaluate receiver designs. In the past 1.5 years, several heat pipe receivers have been tested on Sandia`s test bed concentrators (TBC`s) and 60-kW{sub t} solar furnace. A screen-wick heat pipe developed by Dynatherm was tested to 27.5 kW{sub t} throughput. A Cummins Power Generation (CPG)/Thermacore 30-kW{sub t} heat pipe was pushed to a throughput of 41 kW{sub t} to verify design models. A Sandia-design screen-wick and artery 75-kW{sub t} heat pipe and a CPG/Thermacore 75-kW{sub t} sintered-wick heat pipe were also limit tested on the TBC. This report reviews the design of these receivers, and compares test results with model predictions.

Rawlinson, S.; Cordeiro, P.; Dudley, V.; Moss, T.

1993-07-01T23:59:59.000Z

140

Neutronic and thermal design considerations for heat-pipe reactors  

SciTech Connect

SABRE (Space-Arena Baseline Reactor) is a 100-kW/sub e/, heat-pipe-cooled, beryllium-reflected, fast reactor that produces heat at a temperature of 1500/sup 0/K and radiatively transmits it to high-temperature thermoelectric (TE) conversion elements. The use of heat pipes for core heat removal eliminates single-point failure mechanisms in the reactor cooling system, and provides minimal temperature drop radiative coupling to the TE array, as well as automatic, self-actuating removal of reactor afterheat. The question of how the failure of a fuel module heat pipe will affect neighboring fuel modules in the core is discussed, as is fission density peaking that occurs at the core/reflector interface. Results of neutronic calculations of the control margin available are described. Another issue that is addressed is that of helium generation in the heat pipes from neutron reactions in the core with the heat pipe fluid. Finally, the growth potential of the SABRE design to much higher powers is examined.

Ranken, W.A.; Koenig, D.R.

1983-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Micro loop heat pipe evaporator coherent pore structures  

E-Print Network (OSTI)

Loop heat pipes seem a promising approach for application in modern technologies where such thermal devices as cooling fans and radiators cannot satisfy overall requirements. Even though a loop heat pipe has a big potential to remove the thermal energy from a high heat flux source, the heat removal performance of heat pipes cannot be predicted well since a first principles of evaporation has not been established. An evaporation model based on statistical rate theory has been recently suggested by Ward and developed for a single pore by Oinuma. A loop heat pipe with coherent pore wick structure has been proposed as a design model. To limit product development risk and to enhance performance assurance, design model features and performance parameters have been carefully reviewed during the concept development phase and have been deliberately selected so as to be well-founded on the limited existing loop heat pipe knowledge base. A first principles evaporation model has been applied for evaporator geometry optimization. A number of iteration calculations have been performed to satisfy design and operating limitations. A set of recommendations for design optimization has been formulated. An optimal model has been found and proposed for manufacture and experimental investigation.

Alexseev, Alexandre Viktorovich

2003-08-01T23:59:59.000Z

142

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

Science Conference Proceedings (OSTI)

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

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

2010-09-15T23:59:59.000Z

143

Heat Pipe Embedded AlSiC Plates for High Conductivity - Low CTE Heat Spreaders  

SciTech Connect

Heat pipe embedded aluminum silicon carbide (AlSiC) plates are innovative heat spreaders that provide high thermal conductivity and low coefficient of thermal expansion (CTE). Since heat pipes are two phase devices, they demonstrate effective thermal conductivities ranging between 50,000 and 200,000 W/m-K, depending on the heat pipe length. Installing heat pipes into an AlSiC plate dramatically increases the plate’s effective thermal conductivity. AlSiC plates alone have a thermal conductivity of roughly 200 W/m-K and a CTE ranging from 7-12 ppm/ deg C, similar to that of silicon. An equivalent sized heat pipe embedded AlSiC plate has effective thermal conductivity ranging from 400 to 500 W/m-K and retains the CTE of AlSiC.

Johnson, Matthew (DOE/NNSA Kansas City Plant (United States)); Weyant, J.; Garner, S. (Advanced Cooling Technologies, Inc. (Lancaster, PA (United States)); Occhionero, M. (CPS Technologies Corporation, Norton, MA (United States))

2010-01-07T23:59:59.000Z

144

LiCl Dehumidifier LiBr absorption chiller hybrid air conditioning system with energy recovery  

SciTech Connect

This invention relates to a hybrid air conditioning system that combines a solar powered LiCl dehumidifier with a LiBr absorption chiller. The desiccant dehumidifier removes the latent load by absorbing moisture from the air, and the sensible load is removed by the absorption chiller. The desiccant dehumidifier is coupled to a regenerator and the desiccant in the regenerator is heated by solar heated hot water to drive the moisture therefrom before being fed back to the dehumidifier. The heat of vaporization expended in the desiccant regenerator is recovered and used to partially preheat the driving fluid of the absorption chiller, thus substantially improving the overall COP of the hybrid system.

Ko, Suk M. (Huntsville, AL)

1980-01-01T23:59:59.000Z

145

Heat pipe effects in nuclear waste isolation: a review  

SciTech Connect

The existence of fractures favors heat pipe development in a geologic repository as does a partially saturated medium. A number of geologic media are being considered as potential repository sites. Tuff is partially saturated and fractured, basalt and granite are saturated and fractured, salt is unfractured and saturated. Thus the most likely conditions for heat pipe formation occur in tuff while the least likely occur in salt. The relative permeability and capillary pressure dependences on saturation are of critical importance for predicting thermohydraulic behavior around a repository. Mineral redistribution in heat pipe systems near high-level waste packages emplaced in partially saturated formations may significantly affect fluid flow and heat transfer processes, and the chemical environment of the packages. We believe that a combined laboratory, field, and theoretical effort will be needed to identify the relevant physical and chemical processes, and the specific parameters applicable to a particular site. 25 refs., 1 fig.

Doughty, C.; Pruess, K.

1985-12-01T23:59:59.000Z

146

Transient heat pipe investigations for space power systems  

SciTech Connect

A 4-meter long, high temperature, high power, molybdenum-lithium heat pipe has been fabricated and tested in transient and steady state operation at temperatures to 1500 K. Maximum power throughput during the tests was approximately 37 kW/cm/sup 2/ for the 1.4 cm diameter vapor space of the annular wick heat pipe. The evaporator flux density for the tests was 150.0 W/cm/sup 2/ over a length of 40 cm. Condenser length was approximately 3.0 m with radiant heat rejection from the condenser to a coaxial, water cooled radiation calorimeter. A variable radiation shield, controllable from the outside of the vacuum enclosure, was used to vary the load on the heat pipe during the tests. 1 ref., 9 figs.

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

1985-01-01T23:59:59.000Z

147

Heat pipes for enhanced cooldown of cyrogenic systems  

SciTech Connect

In many important cryogenic applications the use of liquid cryogens for system cooling are either not feasible or are unsuitable. In such cases a cryogenic refrigeration system or multi stage cryocooler must be employed to provide the necessary cooling. To shorten cooldown time for such a system, especially if the thermal mass is large, a thermal shunt directly connecting the first stage of the cryocooler to the load during cooldown is desirable. This thermal shunt allows effective utilization of the greater cooling power available from the first stage of the cryocooler early in the cooldown. Upon reaching operating temperature, the thermal shunt must exhibit a high resistance to thermally isolate the first stage of the cryocooler from the load. Heat pipes are well suited to achieve these objectives. The Advanced Lightweight Influence Sweep System (ALISS), under development by the U.S. Navy for shallow water magnetic mine countermeasures, employs a large, conductively cooled, superconducting magnet that must be cooled from 300 to 4.2 K. Cryogenic heat pipes acting as cryocooler thermal shunts are used to shorten the cooldown time. Ethane, nitrogen and oxygen were evaluated as possible working fluids. A thermal model of the ALISS was developed to evaluate the cooldown performance of various heat pipe combinations. In conjunction with heat pipe performance tests, this model was used to select a suitable design for the heat pipe thermal shunts.

Prenger, F.C.; Hill, D.D.; Daney, D.E.; Daugherty, M.A.; Green, G.F.; Chafe, J.; Heiberger, M.; Langhorn, A.

1996-08-01T23:59:59.000Z

148

Heat-pipe development for high-temperature recuperator application  

SciTech Connect

Heat pipes have been developed for operation in oxidizing atmospheres at temperatures above 1100/sup 0/K. The heat pipes comprise a metallic liner and wick structure with a protective outer shell of an oxidation resistant material. The working fluids used in the heat pipes are alkali metals. A number of configurations have been evaluated, ranging from pipes using a metallic inner liner of a chemically vapor deposited (CVD) refractory metal applied to ceramic tubing, to one utilizing ferrous materials with an outer layer of a developed oxide. A promising intermediate configuration consisting of free-standing refractory tubing covered with a layered structure of fine grain, equi-axed CVD silicon carbide has also been evaluated. The test heat pipe was fabricated using low-carbon, arc-cast molybdenum tubing and a wick composed of 150 mesh molybdenum screen. Hafnium gettering was used with sodium working fluid. Assembly of the pipe was by electron beam welding. Following closure and capping of the fill tube the assembly was operated in a vacuum for several hours prior to the chemical vapor deposition of the exterior ceramic coating. After coating, the pipe was operated in air and in combustion gases for performance evaluation. The use of iron-chromium-aluminum alloys as container materials for operating in high temperature oxidizing and sulfiding gas streams has been investigated. Alloys of this type develop heavy, protective oxide surface layers when exposed to high temperature oxidizing atmospheres, and are commonly used in electrical heating elements because of their exceptional oxidation resistance.

Merrigan, M.; Dunwoody, W.; Lundberg, L.

1981-01-01T23:59:59.000Z

149

Heating and cooling the Raft River geothermal transite pipe line  

SciTech Connect

A preliminary transient heat transfer analysis to aid in defining operating limits for the 4000-foot-long transite pipe line at the Raft River geothermal test site was completed. The heat transfer problem was to determine the time required to cool down the line from a 285/sup 0/F operating temperature to 50/sup 0/F and the time to heat up the line from 50/sup 0/F to 285/sup 0/F such that the temperature differential across the pipe wall will not exceed 25/sup 0/F. The pipe and the surrounding soil was modeled with a two-dimensional heat transfer computer code assuming constant convective heat transfer at the soil-atmosphere interface. The results are sensitive to the soil thermal conductivity used in the calculation and imply that measurement of soil thermal conductivity used in the calculation and imply that measurement of soil thermal properties should be made in order to refine the calculations. Also, the effect of variable convective heat transfer at the soil surface should be investigated. However, the results reported here indicate the order of magnitude to be expected for cool-down and heat-up times when operating the transite pipe at the stated condition.

Shaffer, C.J.

1977-06-01T23:59:59.000Z

150

Potential of the heat pipe in coal gasification processes  

SciTech Connect

The declining production of natural gas in the United States has provided great impetus to the development of economcal methods of producing methane from coal. Coal gasification systems share in common a need for highly efficient heat transfer and energy recovery methods in order to maximize the coal-methane conversion efficiency. Characteristics of heat pipe heat transfer units that offer potential for increasing conversion efficiency and/or reducing production costs include: (1) complete physical separation of process streams, (2) capability of handling more than two process streams in a single unit, (3) heat removal at near-constant temperature, (4) high heat recovery efficiency, (5) low operating cost-with no requirement for auxiliary power, and (6) relative ease of cleaning. Design concepts incorporating heat pipes into indirect coal gasification units, methanators, and energy recovery units are presented and technological impediments that must be surmounted in the successful development of these units are discussed.

Ranken, W.A.

1976-01-01T23:59:59.000Z

151

Nonlinear thermomechanical finite-element modeling, analysis and characterization of multi-turn oscillating heat pipes .  

E-Print Network (OSTI)

??Oscillating heat pipes (OHPs) are promising heat dissipation devices for modern electronic systems due to their high heat transfer rate, simple construction and low manufacturing… (more)

Peng, Hao

2012-01-01T23:59:59.000Z

152

Performance predictions of silica-gel desiccant dehumidifiers. Technical report No. 3  

SciTech Connect

The analysis of a cross-cooled desiccant dehumidifier using silica gel in the form of sheets is described. This unit is the principal component of solar powered desiccant air conditioning system. The mathematical model has first been formulated describing the dynamics of the dehumidifier. The model leads to a system of nonlinear coupled heat and mass transfer equations for the sorption processes and linear heat transfer equations for the purging processes. The model accounts for the gas film resistance and for the moisture diffusion in the desiccant. The governing equations are solved by a finite difference scheme to obtain periodic steady state solutions. The accuracy of the theoretical predictions is ascertained by comparing them with the experimental results. The performance of the dehumidifier, for a chosen set of initial conditions and dehumidifier parameters, has also been given.

Mathiprakasam, B.; Lavan, Z.

1980-01-01T23:59:59.000Z

153

Thermal analysis of a piston cooling system with reciprocating heat pipes  

SciTech Connect

The reciprocating heat pipe is a very promising technology in engine piston cooling, especially for heavy-duty diesel engines. The concept of the reciprocating heat pipe is verified through the experimental observation of a transparent heat pipe and by thermal testing of a copper/water reciprocating heat pipe. A comparative thermal analysis on the reciprocating heat pipe and gallery cooling systems is performed. The approximate analytical results show that the piston ring groove temperature can be significantly reduced using heat pipe cooling technology, which could contribute to an increase in engine thermal efficiency and a reduction in environmental pollution.

Cao, Y.; Wang, Q. [Florida International Univ., Miami, FL (United States). Dept. of Mechanical Engineering

1995-04-01T23:59:59.000Z

154

Felt-metal-wick heat-pipe solar receiver  

DOE Green Energy (OSTI)

Reflux heat-pipe receivers have been identified as a desirable interface to couple a Stirling-cycle engine with a parabolic dish solar concentrator. The reflux receiver provides power nearly isothermally to the engine heater heads while decoupling the heater head design from the solar absorber surface design. The independent design of the receiver and engine heater head leads to higher system efficiency. Heat pipe reflux receivers have been demonstrated at approximately 65 kW{sub t} power throughput. Several 25 to 30-kW{sub e} Stirling-cycle engines are under development, and will soon be incorporated in commercial dish-Stirling systems. These engines will require reflux receivers with power throughput limits reaching 90-kW{sub t}. The extension of heat pipe technology from 60 kW{sub t} to 100 kW{sub t} is not trivial. Current heat pipe wick technology is pushed to its limits. It is necessary to develop and test advanced wick structure technologies to perform this task. Sandia has developed and begun testing a Bekaert Corporation felt metal wick structure fabricated by Porous Metal Products Inc. This wick is about 95% porous, and has liquid permeability a factor of 2 to 8 times higher than conventional technologies for a given maximum pore radius. The wick has been successfully demonstrated in a bench-scale heat pipe, and a full-scale on-sun receiver has been fabricated. This report details the wick design, characterization and installation into a heat pipe receiver, and the results of the bench-scale tests are presented. The wick performance is modeled, and the model results are compared to test results.

Andraka, C.E.; Adkins, D.R.; Moss, T.A. [Sandia National Labs., Albuquerque, NM (United States); Cole, H.M. [Porous Metal Products, Jacksboro, TX (United States); Andreas, N.H. [Bekaert Corp., Marietta, GA (United States)

1994-12-31T23:59:59.000Z

155

Experimental Results on Advanced Rotary Desiccant Dehumidifiers  

E-Print Network (OSTI)

The Solar Energy Research Institute (SERI) has developed the Cyclic Test Facility (CTF) to develop and validate analytical methods for evaluating and predicting the performance of advanced rotary dehumidifiers. This paper describes the CTF, the dehumidifiers tested at the CTF, and the analytical methods used. The results reported provide an engineering data base and a design tool for evaluating rotary dehumidifiers for desiccant cooling applications.

Barathan, D.; Parsons, J. M.; MaClaine-Cross, I.

1986-01-01T23:59:59.000Z

156

Experimental results on advanced rotary desiccant dehumidifiers  

DOE Green Energy (OSTI)

The Solar Energy Research Institute (SERI) has developed the Cyclic Test Facility (CTF) to develop and validate analytical methods for evaluating and predicting the performance of advanced rotary dehumidifiers. This paper describes the CTF, the dehumidifiers tested at the CTF, and the analytical methods used. The results reported provide an engineering data base and a design tool for evaluating rotary dehumidifiers for desiccant cooling applications.

Bharathan, D.; Parsons, J.; Maclaine-cross, I.

1986-08-01T23:59:59.000Z

157

Heat Pipe Solar Receiver Development Activities at Sandia National Laboratories  

SciTech Connect

Over the past decade, Sandia National Laboratories has been involved in the development of receivers to transfer energy from the focus of a parabolic dish concentrator to the heater tubes of a Stirling engine. Through the isothermal evaporation and condensation of sodium. a heat-pipe receiver can efficiently transfer energy to an engine's working fluid and compensate for irregularities in the flux distribution that is delivered by the concentrator. The operation of the heat pipe is completely passive because the liquid sodium is distributed over the solar-heated surface by capillary pumping provided by a wick structure. Tests have shown that using a heat pipe can boost the system performance by twenty percent when compared to directly illuminating the engine heater tubes. Designing heat pipe solar receivers has presented several challenges. The relatively large area ({approximately}0.2 m{sup 2}) of the receiver surface makes it difficult to design a wick that can continuously provide liquid sodium to all regions of the heated surface. Selecting a wick structure with smaller pores will improve capillary pumping capabilities of the wick, but the small pores will restrict the flow of liquid and generate high pressure drops. Selecting a wick that is comprised of very tine filaments can increase the permeability of the wick and thereby reduce flow losses, however, the fine wick structure is more susceptible to corrosion and mechanical damage. This paper provides a comprehensive review of the issues encountered in the design of heat pipe solar receivers and solutions to problems that have arisen. Topics include: flow characterization in the receiver, the design of wick systems. the minimization of corrosion and dissolution of metals in sodium systems. and the prevention of mechanical failure in high porosity wick structures.

Adkins, D.R.; Andraka, C.E.; Moreno, J.B.; Moss, T.A.; Rawlinson, K.S.; Showalter, S.K.

1999-01-08T23:59:59.000Z

158

Heat Pipe Solar Receiver Development Activities at Sandia National Laboratories  

DOE Green Energy (OSTI)

Over the past decade, Sandia National Laboratories has been involved in the development of receivers to transfer energy from the focus of a parabolic dish concentrator to the heater tubes of a Stirling engine. Through the isothermal evaporation and condensation of sodium. a heat-pipe receiver can efficiently transfer energy to an engine's working fluid and compensate for irregularities in the flux distribution that is delivered by the concentrator. The operation of the heat pipe is completely passive because the liquid sodium is distributed over the solar-heated surface by capillary pumping provided by a wick structure. Tests have shown that using a heat pipe can boost the system performance by twenty percent when compared to directly illuminating the engine heater tubes. Designing heat pipe solar receivers has presented several challenges. The relatively large area ({approximately}0.2 m{sup 2}) of the receiver surface makes it difficult to design a wick that can continuously provide liquid sodium to all regions of the heated surface. Selecting a wick structure with smaller pores will improve capillary pumping capabilities of the wick, but the small pores will restrict the flow of liquid and generate high pressure drops. Selecting a wick that is comprised of very tine filaments can increase the permeability of the wick and thereby reduce flow losses, however, the fine wick structure is more susceptible to corrosion and mechanical damage. This paper provides a comprehensive review of the issues encountered in the design of heat pipe solar receivers and solutions to problems that have arisen. Topics include: flow characterization in the receiver, the design of wick systems. the minimization of corrosion and dissolution of metals in sodium systems. and the prevention of mechanical failure in high porosity wick structures.

Adkins, D.R.; Andraka, C.E.; Moreno, J.B.; Moss, T.A.; Rawlinson, K.S.; Showalter, S.K.

1999-01-08T23:59:59.000Z

159

Test results of a Stirling engine utilizing heat exchanger modules with an integral heat pipe  

SciTech Connect

The Heat Pipe Stirling Engine (HP-1000), a free-piston Stirling engine incorporating three heat exchanger modules, each having a sodium filled heat pipe, has been tested at the NASA-Lewis Research Center as part of the Civil Space Technology Initiative (CSTI). The heat exchanger modules were designed to reduce the number of potential flow leak paths in the heat exchanger assembly and incorporate a heat pipe as the link between the heat source and the engine. An existing RE-1000 free-piston Stirling engine was modified to operate using the heat exchanger modules. This paper describes heat exchanger module and engine performance during baseline testing. Condenser temperature profiles, brake power, and efficiency are presented and discussed.

Skupinski, R.C.; Tower, L.K.; Madi, F.J.; Brusk, K.D.

1993-04-01T23:59:59.000Z

160

Modelling the mass migration phenomena in partially frozen heat pipes  

SciTech Connect

Liquid metal heat pipes operated at power throughputs well below their design point and with sink temperatures below the freezing temperature of the working fluid may fail as a result of the working fluid migrating to a cold region within the pipe, freezing there, and not returning to the evaporator section. Eventually, sufficient working fluid inventory may be lost to the cold region to cause a local dry-out condition in the evaporator. A joint experimental and analytical effort by the Air Force Phillips Laboratory and Los Alamos National Laboratory is underway to investigate this phenomena. This paper presents an analytical model developed to describes this phenomena. The model provides for analytic determination of heat pipe temperature profiles, freeze-front locations and mass migration rates.

Keddy, M.D.; Merrigan, M.A. [Los Alamos National Lab., NM (United States); Critchley, E. [Phillips Lab., Albuquerque, NM (United States)

1993-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Heat Pipe Performance Enhancement with Binary Mixture Fluids that Exhibit Strong Concentration Marangoni Effects  

E-Print Network (OSTI)

inclined, gravity-assisted, brass heat pipe with a 0.05M 2-inclined, gravity-assisted, brass heat pipe, with a 0.05M 2-Evaporator c Condenser Br Brass adia Adiabatic in input cold

Armijo, Kenneth Miguel

2011-01-01T23:59:59.000Z

162

Entirely passive heat pipe apparatus capable of operating against gravity  

DOE Patents (OSTI)

The disclosure is directed to an entirely passive heat pipe apparatus capable of operating against gravity for vertical distances in the order of 3 to 7 meters and more. A return conduit into which an inert gas is introduced is used to lower the specific density of the working fluid so that it may be returned a greater vertical distance from condenser to evaporator.

Koenig, Daniel R. (Santa Fe, NM)

1982-01-01T23:59:59.000Z

163

Passive ice freezing-releasing heat pipe. [Patent application  

DOE Patents (OSTI)

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

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

1980-09-29T23:59:59.000Z

164

Heat pipe technology: a bibliography with abstracts. Quarterly update, January-March 1980  

SciTech Connect

A bibliography of 111 citations on heat pipe technology, including a large number of citations on heat pipe uses in energy conservation and solar energy, is presented as a first quarter 1980 update in the Heat Pipe Technology Bibliographic series. (LCL)

1980-07-01T23:59:59.000Z

165

Assembly and testing of a composite heat pipe thermal intercept for HTS current leads  

SciTech Connect

We are building high temperature superconducting (HTS) current leads for a demonstration HTS-high gradient magnetic separation (HGMS) system cooled by a cryocooler. The current leads are entirely conductively cooled. A composite nitrogen heat pipe provides efficient thermal communication, and simultaneously electrical isolation, between the lead and an intermediate temperature heat sink. Data on the thermal and electrical performance of the heat pipe thermal intercept are presented. The electrical isolation of the heat pipe was measured as a function of applied voltage with and without a thermal load across the heat pipe. The results show the electrical isolation with evaporation, condensation and internal circulation taking place in the heat pipe.

Daugherty, M.A.; Daney, D.E.; Prenger, F.C.; Hill, D.D.; Williams, P.M.; Boenig, H.J.

1995-09-01T23:59:59.000Z

166

Laboratory Performance Testing of Residential Dehumidifiers  

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

Laboratory Performance Laboratory Performance Testing of Residential Dehumidifiers Building America Stakeholders Meeting Jon Winkler March 2, 2012 2 Motivation * Solution: Performance map across a variety of operating conditions Dehumidifier Manufacturer Data ( ) in in RH T f e Performanc , = 80 F 60% RH Normalized Energy Factor Entering Drybulb Temperature (°C) Simulation Tool Input ? 3 ENERGY STAR Efficiency Criteria 1 2 3 4 0 30 60 90 120 150 Energy Factor (L/kWh) Dehumidifier Capacity (pints/day) ENERGY STAR v2.0 Efficiency Criteria Dehumidifiers Tested ENERGY STAR Products Non ENERGY STAR Products v3.0 Criteria 4 NREL Technical Report Laboratory Test Report for Six ENERGY STAR® Dehumidifiers Jon Winkler, Dane Christensen, and Jeff Tomerlin NREL/TP-5500-52791 December 2011

167

Design and demonstration of heat pipe cooling for NASP and evaluation of heating methods at high heating rates  

SciTech Connect

An evaluation of two heating methods for demonstration of NASP leading edge heat pipe technology was conducted. The heating methods were and rf induction heated plasma jet and direct rf induction. Tests were conducted to determine coupling from the argon plasma jet on a surface physically similar to a heat pipe. A molybdenum tipped calorimeter was fabricated and installed in an rf induction heated plasma jet for the test. The calorimetric measurements indicated a maximum power coupling of approximately 500 W/cm{sup 2} with the rf plasma jet. The effect of change in gas composition on the heating rate was investigated using helium. An alternative to the plasma heating of a heat pipe tip, an rf concentrator was evaluated for coupling to the hemispherical tip of a heat pipe. A refractory metal heat pipe was designed, fabricated, and tested for the evaluation. The heat pipe was designed for operation at 1400 to 1900 K with power input to 1000 W/cm{sup 2} over a hemispherical nose tip. Power input of 800 W/cm{sup 2} was demonstrated using the rf concentrator. 2 refs., 13 figs.

Merrigan, M.A.; Sena, J.T.

1989-01-01T23:59:59.000Z

168

Innovative Porous Media Approach in Modeling Biofilm Applications, Human Eye and Nanofluid Based Heat Pipes  

E-Print Network (OSTI)

heat pipe for different condenser temperatures, a) Al 2 O 3;between evaporator and condenser in disk-shaped heat pipebetween evaporator and condenser for the rectangular shaped

Shafahi, Maryam

2010-01-01T23:59:59.000Z

169

Effect of Working Fluid and Fluid Loading on the Performance of Rotating Heat Pipes.  

E-Print Network (OSTI)

?? The steady state heat transfer performance of axially rotating heat pipes with methanol, ethanol and water as working fluid was measured for rotational speeds… (more)

Home, Deepayan

2004-01-01T23:59:59.000Z

170

Numerical Modeling of Heat Pipe Radiator and Fin Size Optimization for Low and No Gravity Environments.  

E-Print Network (OSTI)

??A heat-pipe radiator element has been designed and modeled to study the efficiency of heat transfer for low and no gravity environments, like in lunar… (more)

Bieger, Virginia Ruth

2013-01-01T23:59:59.000Z

171

A study of two phases heat transport capacity in a micro heat pipe  

Science Conference Proceedings (OSTI)

Present study modifies Cotter's model by using the dimensionless liquid flow shape factor, K1, to predict the maximum heat transport capacity and to discus the effects of contact angle. The results indicated that as the dimensionless ... Keywords: Cotter's model, contact angle, dimensionless, heat pipe, heat transport capacity, shape factor

Cheng-Hsing Hsu; Kuang-Yuan Kung; Shu-Yu Hu; Ching-Chuan Chang

2009-07-01T23:59:59.000Z

172

Heat Pipe Technology, a bibliography with abstracts, quarterly update. Quarterly report No. 3  

SciTech Connect

Heat Pipe Technology is a continuing bibliographic summary of research on the subject of the heat pipe. The first volume was published in the spring of 1971 and is cumulative through March of that year. The 1971, 1972, 1973 and 1974 Annual Supplements have been published and distributed. Additional copies are available from the Technology Application Center. This update to Heat Pipe Technology cites the additional references identified during July, August, and September of 1975. It is the third in a 1975 quarterly series intended to provide 'current awareness' to heat pipe researchers. No Heat Pipe related patents were included in this issue.

1975-09-30T23:59:59.000Z

173

Thermochemical correlation of material transport in an alkali metal heat pipe  

SciTech Connect

The use of high-power heat pipes in space power systems requires a means of life prediction. The design lifetimes required make experimental determination of life impractical. Thermochemical modeling of heat pipe corrosive failure modes has been investigated as a means of making such prediction. Results have been applied to tests of molybdenum-lithium heat pipes operating from 1400 to 1500/sup 0/K. A free energy minimization routine coupled to a hydrodynamic model of the operating heat pipe has been used to give local equilibrium values of reaction products as a function of operating time. The predicted reactions for critical regions of the heat pipe were compared with limited results of post-test examinations. Corrosive damage to the heat pipe wick structure was correlated with high oxygen and nitrogen activity in the evaporator region of the heat pipe.

Merrigan, M.A.; Feber, R.C.

1985-01-01T23:59:59.000Z

174

Engineering design aspects of the heat-pipe power system  

SciTech Connect

The Heat-pipe Power System (HPS) is a near-term, low-cost space power system designed at Los Alamos that can provide up to 1,000 kWt for many space nuclear applications. The design of the reactor is simple, modular, and adaptable. The basic design allows for the use of a variety of power conversion systems and reactor materials (including the fuel, clad, and heat pipes). This paper describes a project that was undertaken to develop a database supporting many engineering aspects of the HPS design. The specific tasks discussed in this paper are: the development of an HPS materials database, the creation of finite element models that will allow a wide variety of investigations, and the verification of past calculations.

Capell, B.M.; Houts, M.G.; Poston, D.I.; Berte, M.

1997-10-01T23:59:59.000Z

175

Design and Testing of Metal and Silicon Heat Spreaders with Embedded Micromachined Heat Pipes  

Science Conference Proceedings (OSTI)

The authors have developed a new type of heat spreader based on the integration of heat pipes directly within a thin planar structure suitable for use as a heat spreader or as the base layer in a substrate. The process uses micromachining methods to produce micron scale patterns that act as a wick in these small scale heat pipes. By using silicon or a low expansion metal as the wall material of these spreaders, they achieve a good match to the thermal coefficient of expansion of the die. The match allows the use of a thin high performance die attachment even on large size die. The embedded heat pipes result in high effective thermal conductivity for the new spreader technology.

Benson, D.A.; Robino, C.V.

1999-02-22T23:59:59.000Z

176

Method of manufacturing a heat pipe wick with structural enhancement  

SciTech Connect

Heat pipe wick structure wherein a stout sheet of perforated material overlays a high performance wick material such as stainless steel felt affixed to a substrate. The inventive structure provides a good flow path for working fluid while maintaining durability and structural stability independent of the structure (or lack of structure) associated with the wick material. In one described embodiment, a wick of randomly laid .about.8 micron thickness stainless steel fibers is sintered to a metal substrate and a perforated metal overlay.

Andraka, Charles E. (Albuquerque, NM); Adkins, Douglas R. (Albuquerque, NM); Moreno, James B. (Albuquerque, NM); Rawlinson, K. Scott (Albuquerque, NM); Showalter, Steven K. (Albuquerque, NM); Moss, Timothy A. (Albuquerque, NM)

2006-10-24T23:59:59.000Z

177

Dehumidifying Air for Cooling & Refrigeration: Nanotechnology Membrane-based Dehumidifier  

SciTech Connect

Broad Funding Opportunity Announcement Project: Dais is developing a product called NanoAir which dehumidifies the air entering a building to make air conditioning more energy efficient. The system uses a polymer membrane that allows moisture but not air to pass through it. A vacuum behind the membrane pulls water vapor from the air, and a second set of membranes releases the water vapor outside. The membrane’s high selectivity translates into reduced energy consumption for dehumidification. Dais’ design goals for NanoAir are the use of proprietary materials and processes and industry-standard installation techniques. NanoAir is also complementary to many other energy saving strategies, including energy recovery.

None

2010-10-01T23:59:59.000Z

178

Analysis of heat-pipe absorbers in evacuated-tube solar collectors  

SciTech Connect

Heat transfer in evacuated-tube solar collectors with heat-pipe absorbers is compared with that for similar collectors with flow-through absorbers. In systems that produce hot water or other heated fluids, the heat-pipe absorber suffers a heat transfer penalty compared with the flow-through absorber, but in many cases the penalty can be minimized by proper design at the heat-pipe condenser and system manifold. The heat transfer penalty decreases with decreasing collector heat loss coefficient, suggesting that evacuated tubes with optical concentration are more appropriate for use with heat pipes than evacuated or nonevacuated flat-plate collectors. When the solar collector is used to drive an absorption chiller, the heat-pipe absorber has better heat transfer characteristics than the flow-through absorbers.

Hull, J.R.; Schertz, W.W.; Allen, J.W.

1986-02-01T23:59:59.000Z

179

Analysis of asymmetric disk-shaped and flat-plate heat pipes  

SciTech Connect

An analytical investigation and conceptual design of a disk-shaped asymmetric heat pipe is presented in this work. Using the conservative formulations for the steady incompressible vapor and liquid flow for a disk-shaped heat pipe, an in-depth integral analysis is applied. Analytical results for the asymmetric vapor velocity profile, the vapor and liquid pressure distributions, and the vapor temperature distribution in the heat pipe are obtained and compared to those of a rectangular flat-plate heat pipe. The analysis establishes the physics of the process and the intrawick interactions for the disk-shaped heat pipe. The effects of variations in the thicknesses of the vapor channel and the wick as well as the heat pipe on the performance of both disk-shaped and rectangular flat-plate heat pipes are analyzed in detail and compared with each other. The factors limiting heat pipe performance are discussed and the results show that the disk-shaped heat pipe, while utilizing a smaller surface area and being more adaptable to several application areas, significantly increases the heat transfer capability per unit surface area compared to rectangular flat-plate heat pipe. 19 refs., 7 figs.

Vafai, K.; Zhu, N.; Wang, W. (Ohio State Univ., Columbus, OH (United States))

1995-02-01T23:59:59.000Z

180

High-performance dehumidifier for solar desiccant cooling systems  

DOE Green Energy (OSTI)

An advanced-design, one-tenth-scale dehumidifier for use in residential solar desiccant-cooling systems has been built and tested. The new dehumidifier was designed using a parallel-passage geometry, where air flows through channels formed by walls coated with fine-ground silica gel desiccant. This concept has a high heat and mass transfer effectiveness and promises to double the coefficient of performance of the desiccant cooling system to 1.1 kW cooling output/kW thermal input. The parallel-passage design was found to have very low pressure drop, typically 20 Pa (.08 in. water) at design conditions. The low fan power required to drive such low pressure drop components indicates that electrical COP's in the range of 8.0 to 8.2 kW cooling output/kW electrical input are possible. Results presented include parametric studies of the effect of conditions such as temperature and humidity and design parameters such as desiccant particle size and channel spacing on dehumidifier performance.

Schlepp, D.

1983-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Niobium 1% zirconium/potassium and titanium/potassium life-test heat pipe design and testing  

SciTech Connect

Experimental lifetime performance studies currently in progress use Niobium-1% Zirconium (Nb-1Zr) and Titanium (Ti) heat pipes with potassium (K) as the working fluid. A heat pipe life-test matrix has been developed for testing the heat pipes. Because the corrosion rates in alkali metal heat pipes are affected by temperature and working fluid evaporation flux, the variable parameters of the experimental matrix are established as steady operating temperature and input heat flux density. Total impurity inventory is a factor in corrosion rate so impurity levels are being evaluated in the heat pipe materials before and after testing. Eight Nb-1Zr/K heat pipes were designed, fabricated, and tested. Two of the heat pipes have completed testing whereas the other six are currently in test. These are gravity-assist heat pipes operating in a reflux mode. The heat pipes are tested by sets, one set of two and two sets of three heat pipes. Three Ti/K heat pipes are also in life test. These heat pipes are tested as a set in a horizontal position in a capillary pumped annular flow mode. Each of the heat pipes is encapsulated in a quartz vacuum container with a water calorimeter over the vacuum container for power throughput measurements. Thermocouples are attached to the heat pipes for measuring temperature. Heat input to the heat pipes is via an rf coil. The heat pipes are operating at between 800 and 900 K, with heat input fluxes of 13.8 to 30 W/sq cm. Of the Nb-1Zr/K heat pipes, two of the heat pipes have been in operation for 14,000 hours, three over 10,000 hours, and three over 7,000 hours. The Ti/K heat pipes have been in operation for 1,266 hours. 5 refs., 4 figs., 1 tab.

Sena, J.T.; Merrigan, M.A.

1989-01-01T23:59:59.000Z

182

A Gas-Fired Heat Pipe Zone Heater  

E-Print Network (OSTI)

A gas-fired vented zone heater has recently been developed by the Altar Corporation for Colorado State University (CSU) under a Gas Research Institute (GRI) contract. The unit war developed for auxiliary heating applications in passive solar buildings. An early prototype was tested at Altas and operated as expected. The final model was shipped to CSU in December 1983 for testing in the REPEAT Facility at CSU. A heat pipe extends through the wall to the outside of the building. It has a modest water charge which can freeze repeatedly with no damage, since the heat pips is only partially filled. Firing efficiency at 4,000 Btu/b (1.17 kW thermal) is approximately 80%. The unit features a 3 foot by 3 foot radiator mounted inside the room to be heated, and is thermostatically controlled. Ignition is accomplished with an electronic sparker (pilot). The radiator typically operates at 150-180°F (65-82°C), and has been operated at between 2,000 and 5,000 Btu/h (0.6-1.47 kW). Results of testing the vented heat pipe zone heater at CSU arm presented. Also, a method for determining the optimal combination of zone heater, passive solar heating and energy conservation measures has been developed. Nomographs have been developed that may be used by a building designer to determine the optimal combination of zone heater size, passive solar system size, and energy conservation measures for given types of passive solar heating systems in selected locations. A representative nomograph is presented along with a design example.

Winn, C. B.; Burns, P.; Guire, J.

1984-01-01T23:59:59.000Z

183

Heat-pipe development for the SPAR space-power system. [100 kW(e)  

SciTech Connect

The SPAR space power system design is based on a high temperature fast spectrum nuclear reactor that furnishes heat to a thermoelectric conversion system to generate an electrical power output of 100 kW/sub (e)/. An important feature of this design is the use of alkali metal heat pipes to provide redundant, reliable, and low-loss heat transfer at high temperature. Three sets of heat pipes are used in the system. These include sodium/molybdenum heat pipes to transfer heat from the reactor core to the conversion system, potassium/niobium heat pipes to couple the conversion system to the radiator in a redundant manner, and potassium/titanium heat pipes to distribute rejected heat throughout the radiator surface. The designs of these units are discussed and fabrication methods and testing results are described. 12 figures.

Ranken, W.A.

1981-01-01T23:59:59.000Z

184

Development of a compensation chamber for use in a multiple condenser loop heat pipe  

E-Print Network (OSTI)

The performance of many electronic devices is presently limited by heat dissipation rates. One potential solution lies in high-performance air-cooled heat exchangers like PHUMP, the multiple condenser loop heat pipe presented ...

Roche, Nicholas Albert

2013-01-01T23:59:59.000Z

185

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

186

Design and development of a titanium heat-pipe space radiator  

SciTech Connect

A titanium heat-pipe radiator has been designed for use in a 100-kW/sub e/ nuclear-thermoelectric (TE) space power plant. The radiator is required to have a 99% probability of remaining functional at full power at the end of a seven-year mission. The radiator has a conical-cylindrical shape and is compatible for launch in the space shuttle. The radiator heat pipes are arranged into panel segments and each reactor-core thermoelectric heat-pipe unit has four radiator heat pipes for redundancy. Radiator mass was minimized was based on acceptable losses due to micrometeoroid impact. Results of studies on various design parameters are presented in terms of radiator mass. Developments on the design and testing of the radiator heat pipes are also presented. Prototype titanium (potassium working fluid) heat pipes were fabricated and tested in space-simulating conditions. Testing results are compared to analytical performance predictions.

Girrens, S.P.

1982-03-01T23:59:59.000Z

187

Cool-down and frozen start-up behavior of a grooved water heat pipe  

SciTech Connect

A grooved water heat pipe was tested to study its characteristics during the cool-down and start-up periods. The water heat pipe was cooled down from the ambient temperature to below the freezing temperature of water. During the cool-down, isothermal conditions were maintained at the evaporator and adiabatic sections until the working fluid was frozen. When water was frozen along the entire heat pipe, the heat pipe was rendered inactive. The start-up of the heat pipe from this state was investigated under several different operating conditions. The results show the existence of large temperature gradients between the evaporator and the condenser, and the moving of the melting front of the working fluid along the heat pipe. Successful start-up was achieved for some test cases using partial gravity assist. The start-up behavior depended largely on the operating conditions.

Jang, J.H.

1990-12-01T23:59:59.000Z

188

Facilities for testing desiccant materials and geometries of dehumidifiers for solar-regenerated desiccant cooling systems  

SciTech Connect

Four experimental test facilities for characterizing the performance of solid desiccant materials and dehumidifier matrices which have the potential to be used in solar-regenerated desiccant cooling systems are reviewed. The water equilibrium capacity and sorption rates of desiccant materials, depending on their form, can be either measured with a quartz crystal microbalance or a desiccant sorption test facility. Pressure drop, heat- and mass-transfer rates and transient equilibrium dehumidification capacity of a dehumidifier matrices are measured in a desiccant heat and mass transfer test facility. The performance and steady state dehumidification capabilities of prototype dehumidifier components under realistic conditions are measured in a desiccant cyclic test facility. The description of the test apparatus, experimental procedure, measurement errors, and typical results for the four test facilities are presented here. 15 refs., 9 figs., 1 tab.

Pesaran, A.A.; Bingham, C.E.

1988-12-01T23:59:59.000Z

189

Performance predictions and measurements for space-power-system heat pipes  

SciTech Connect

High temperature liquid metal heat pipes designed for space power systems have been analyzed and tested. Three wick designs are discussed and a design rationale for the heat pipe is provided. Test results on a molybdenum, annular wick heat pipe are presented. Performance limitations due to boiling and capillary limits are presented. There is evidence that the vapor flow in the adiabatic section is turbulent and that the transition Reynolds number is 4000.

Prenger, F.C. Jr.

1981-01-01T23:59:59.000Z

190

Start Up of a Nb-1%Zr Potassium Heat Pipe From the Frozen State  

E-Print Network (OSTI)

The start up of a liquid-metal heat pipe from the frozen state was evaluated experimentally with a Nb-1%Zr heat pipe with potassium as the working fluid. The heat pipe was fabricated and tested at Los Alamos National Laboratory. RF induction heating was used to heat 13 cm of the 1-m-long heat pipe. The heat pipe and test conditions are well characterized so that the test data may be used for comparison with numerical analyses. An attempt was made during steady state tests to calibrate the heat input so that the heat input would be known during the transient cases. The heat pipe was heated to 675C with a throughput of 600 W and an input heat flux of 6 W/cm 2 . Steady state tests, start up from the frozen state, and transient variations from steady state were conducted. Nomenclature English L length m . mass flow rate PS power setting r radius q heat flux q" heat flux per unit area T temperature v voltage V volume x axial location on heat pipe Greek e porosity r resist...

Since Its Founding; David E. Glass; Michael A. Merrigan; J. Tom Sena

1998-01-01T23:59:59.000Z

191

Investigation of several critical issues in screen mesh heat pipe manufacturing and operation.  

E-Print Network (OSTI)

??The PhD thesis with the title “Investigation of several critical issues in screen mesh heat pipe manufacturing and operation” presented hereafter describes work carried out… (more)

Engelhardt, Andreas

2010-01-01T23:59:59.000Z

192

Heat Pipe Performance Enhancement with Binary Mixture Fluids that Exhibit Strong Concentration Marangoni Effects.  

E-Print Network (OSTI)

??This research investigates the impact of Marangoni phenomena, with low mixture concentrations of alcohol and water, to enhance thermal transport capability of gravity-assisted heat pipes.… (more)

Armijo, Kenneth Miguel

2011-01-01T23:59:59.000Z

193

Fabrication and Testing of Mo-Re Heat Pipes Embedded in Carbon/Carbon  

E-Print Network (OSTI)

Refractory-composite/heat-pipe-cooled wing and tail leading edges are being considered for use on hypersonic vehicles to limit maximum temperatures to values below material reuse limits and to eliminate the need to actively cool the leading edges. The development of a refractory-composite/heat-pipe-cooled leading edge has evolved from the design stage to the fabrication and testing of heat pipes embedded in carbon/carbon (C/C). A three-foot-long, molybdenum-rhenium heat pipe with a lithium working fluid was fabricated and tested at an operating temperature of 2460F to verify the individual heat-pipe design. Following the fabrication of this heat pipe, three additional heat pipes were fabricated and embedded in C/C. The C/C heat-pipe test article was successfully tested using quartz lamps in a vacuum chamber in both a horizontal and vertical orientation. Start up and steady state data are presented for the C/C heat-pipe test article. Radiography and eddy current evaluations were perform...

David Glass Analytical; David E. Glass; Michael A. Merrigan; J. Tom Sena

1998-01-01T23:59:59.000Z

194

A steady state analysis code for prediction of behavior in loop heat pipes.  

E-Print Network (OSTI)

??The purpose of this work is to prepare an analysis raphics. code for the prediction of Loop Heat Pipe (LHP) behavior in steady-state operation. The… (more)

Hamm, Trenton Allen

2012-01-01T23:59:59.000Z

195

Development of an air-cooled, loop-type heat pipe with multiple condensers.  

E-Print Network (OSTI)

??Thermal management challenges are prevalent in various applications ranging from consumer electronics to high performance computing systems. Heat pipes are capillary-pumped devices that take advantage… (more)

Kariya, H. Arthur (Harumichi Arthur)

2012-01-01T23:59:59.000Z

196

Heat Pipe Performance Enhancement with Binary Mixture Fluids that Exhibit Strong Concentration Marangoni Effects  

E-Print Network (OSTI)

Heat pipe thermal absorbers in solar PV systems have severaland multijunction solar photovoltaic (PV) power generationproduction of the respective PV solar cells. Performance

Armijo, Kenneth Miguel

2011-01-01T23:59:59.000Z

197

Fabrication and Testing of a Leading-Edge-Shaped Heat Pipe  

E-Print Network (OSTI)

A leading-edge-shaped heat pipe was successfully fabricated and tested. The heat pipe had a "D-shaped" cross section and was fabricated from arc cast molybdenumrhenium. An artery was included in the wick. Several issues were resolved during the fabrication of the heat-pipe container and wick with a sharp-leading-edge radius. The heat pipe was tested in a vacuum chamber using induction heating and was started up from the frozen state several times. The heat pipe did operate as a heat pipe over a portion of its length. However, design temperatures and heat fluxes were not obtained due to premature failure of the heat pipe resulting from electrical discharge between the induction heating apparatus and the heat pipe. Introduction Stagnation regions, such as wing and tail leading edges and nose caps, are critical design areas of hypersonic aerospace vehicles because of the hostile thermal environment those regions experience during flight. As a hypersonic vehicle travels through the earth...

David Glass Analytical; David E. Glass; Michael A. Merrigan; J. Tom Sena; Robert S. Reid

1998-01-01T23:59:59.000Z

198

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

E-Print Network (OSTI)

. Internal sources of heat are due to convection from flow of the heat transfer fluid through the pipes. Heat (material, diameter, spacing, and burial depth), (4) system flow rates, (5) heat transfer fluid properties · heat transfer fluid = 42% propylene glycol @ a flow rate of 350 gpm · heat pump model = Water Furnace

199

Optimization of the Fin Heat Pipe for Ventilating and Air Conditioning with a Genetic Algorithm  

E-Print Network (OSTI)

This paper illustrates that use of a heat pipe as a heat-reclaiming device can significantly influence the air-conditioning system. It analyzes the heat transfer model of the uniform annular fin heat pipe under the condition of air conditioning. It establishes functions of the fin structure parameters such as height,spacing and thickness of the fin when the volume of fin is the smallest under unit temperature difference and unit quantity of heat. It uses a genetic algorithm to optimize the model of the uniform annular fin heat pipe. The calculation result shows that the method of genetic algorithm is effective.

Qian, J.; Sun, D.; Li, G.

2006-01-01T23:59:59.000Z

200

Radial heat flux limits in potassium heat pipes: An experimental and analytical investigation  

SciTech Connect

A radial flux limit of 147 W/cm{sup 2} at the wetted inner tube wall has been demonstrated with a Nb-1%Zr/K heat pipe, a flux 5 times greater than the previously accepted safe design level of 25-30 W/cm{sup 2}. The wick structure was an annular gap type fabricated from 100 {times} 100 mesh Nb-1%Zr screen. Rigorous fabrication and cleaning procedures are believed to be critical to good wetting, resulting in significantly reduced active nucleation site size and a higher boiling limit. The procedure used to clean this heat pipe included acid wash, Freon-TF degrease, ethanol wash, high-vacuum firing, and operation as a lithium heat pipe. A heat pipe boiling limit model, based on the active nucleation site radius, is described. An active nucleation site radius of 6 {times} 10{sup -6} m (2.4 {times} 10{sup -4} in) correlates the radial flux boiling limit measured in these tests. 4 refs., 2 figs.

Woloshun, K.A.; Sena, J.T.; Keddy, E.S.; Merrigan, M.A.

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Development of a 75-kW heat-pipe receiver for solar heat-engines  

DOE Green Energy (OSTI)

A program is now underway to develop commercial power conversion systems that use parabolic dish mirrors in conjunction with Stirling engines to convert solar energy to electric power. In early prototypes, the solar concentrator focused light directly on the heater tubes of the Stirling engine. Liquid-metal heat-pipes are now being developed to transfer energy from the focus of the solar concentrator to the heater tubes of the engine. The dome-shaped heat-pipe receivers are approximately one-half meters in diameter and up to 77-kW of concentrated solar energy is delivered to the absorber surface. Over the past several years, Sandia National Laboratories, through the sponsorship of the Department of Energy, has conducted a major program to explore receiver designs and identify suitable wick materials. A high-flux bench-scale system has been developed to test candidate wick designs, and full-scale systems have been tested on an 11-meter test-bed solar concentrator. Procedures have also been developed in this program to measure the properties of wick materials, and an extensive data-base on wick materials for high temperature heat pipes has been developed. This paper provides an overview of the receiver development program and results from some of the many heat-pipe tests.

Adkins, D.R.; Andraka, C.E.; Moss, T.A.

1995-05-01T23:59:59.000Z

202

NREL Tests Dehumidifiers, Defines Simplified Simulation Model (Fact Sheet)  

Science Conference Proceedings (OSTI)

Study of residential dehumidifiers results in practical performance curves for use in whole-building simulation tools.

Not Available

2012-05-01T23:59:59.000Z

203

High temperature superconducting current lead test facility with heat pipe intercepts  

SciTech Connect

A high temperature superconducting (HTS) current lead test facility using heat pipe thermal intercepts is under development at the Superconducting Technology Center at Los Alamos National Laboratory. The facility can be configured for tests at currents up to 1,000 A. Mechanical cryocoolers provide refrigeration to the leads. Electrical isolation is maintained by intercepting thermal energy from the leads through cryogenic heat pipes. HST lead warm end temperature is variable from 65 K to over 90 K by controlling heat pipe evaporator temperature. Cold end temperature is variable up to 30 K. Performance predictions in terms of heat pipe evaporator temperature as a function of lead current are presented for the initial facility configuration, which supports testing up to 200 A. Measurements are to include temperature and voltage gradient in the conventional and HTS lead sections, temperature and heat transfer rate in the heat pipes. as well as optimum and off-optimum performance of the conventional lead sections.

Blumenfeld, P.E.; Prenger, C.; Roth, E.W.; Stewart, J.A.

1998-12-31T23:59:59.000Z

204

Heating and Cooling System Support Equipment Basics | Department of Energy  

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

Heating and Cooling System Support Equipment Basics Heating and Cooling System Support Equipment Basics Heating and Cooling System Support Equipment Basics July 30, 2013 - 3:28pm Addthis Thermostats and ducts provide opportunities for saving energy. Dehumidifying heat pipes provide a way to help central air conditioners and heat pumps dehumidify air. Electric and gas meters allow users to track energy use. Thermostats Programmable thermostats can store and repeat multiple daily settings. Users can adjust the times heating or air-conditioning is activated according to a pre-set schedule. Visit the Energy Saver website for more information about thermostats and control systems in homes. Ducts Efficient and well-designed duct systems distribute air properly throughout a building, without leaking, to keep all rooms at a comfortable

205

Selenide isotope generator for the Galileo Mission. Axially-grooved heat pipe: accelerated life test results  

SciTech Connect

The results through SIG/Galileo contract close-out of accelerated life testing performed from June 1978 to June 1979 on axially-grooved, copper/water heat pipes are presented. The primary objective of the test was to determine the expected lifetime of axially-grooved copper/water heat pipes. The heat pipe failure rate, due to either a leak or a build-up of non-condensible gas, was determined. The secondary objective of the test was to determine the effects of time and temperature on the thermal performance parameters relevant to long-term (> 50,000 h) operation on a space power generator. The results showed that the gas generation rate appears to be constant with time after an initial sharp rise although there are indications that it drops to approximately zero beyond approx. 2000 h. During the life test, the following pipe-hours were accumulated: 159,000 at 125/sup 0/C, 54,000 at 165/sup 0/C, 48,000 at 185/sup 0/C, and 8500 at 225/sup 0/C. Heated hours per pipe ranged from 1000 to 7500 with an average of 4720. Applying calculated acceleration factors yields the equivalent of 930,000 pipe-h at 125/sup 0/C. Including the accelerated hours on vendor tested pipes raises this number to 1,430,000 pipe-hours at 125/sup 0/C. It was concluded that, for a heat pipe temperature of 125/sup 0/C and a mission time of 50,000 h, the demonstrated heat pipe reliability is between 80% (based on 159,000 actual pipe-h at 125/sup 0/C) and 98% (based on 1,430,000 accelerated pipe-h at 125/sup 0/C). Measurements indicate some degradation of heat transfer with time, but no detectable degradation of heat transport. (LCL)

1979-08-01T23:59:59.000Z

206

Procedures for measuring the properties of heat-pipe wick materials  

DOE Green Energy (OSTI)

Accurate measurements of wick properties must be available to design high-performance beat pipes and to properly interpret results from heat pipe tests. In a program that is aimed at developing heat-pipe receivers for solar-Stirling electric systems, we have recently explored procedures to measure the effective pore radius and permeability of wick materials in their final ``as fabricated`` condition. Measurement techniques are compared in this paper and problems that are frequently encountered in measuring wick properties are discussed.

Adkins, D.R.; Dykhuizen, R.C.

1993-07-01T23:59:59.000Z

207

IMPROVING THERMAL PERFORMANCE OF RADIOACTIVE MATERIAL DRUM TYPEPACKAGES BY USING HEAT PIPES  

Science Conference Proceedings (OSTI)

This paper presents a feasibility study to improve thermal loading of existing radioactive material packages by using heat pipes. The concept could be used to channel heat in certain directions and dissipate to the environment. The concept is applied to a drum type package because the drum type packages are stored and transported in an upright position. This orientation is suitable for heat pipe operation that could facilitate the heat pipe implementation in the existing well proven package designs or in new designs where thermal loading is high. In this position, heat pipes utilize gravity very effectively to enhance heat flow in the upward direction Heat pipes have extremely high effective thermal conductivity that is several magnitudes higher than the most heat conducting metals. In addition, heat pipes are highly unidirectional so that the effective conductivity for heat transfer in the reverse direction is greatly reduced. The concept is applied to the 9977 package that is currently going through the DOE certification review. The paper presents computer simulations using typical off-the-shelf heat pipe available configurations and performance data for the 9977 package. A path forward is outlined for implementing the concepts for further study and prototype testing.

Gupta, N

2007-03-06T23:59:59.000Z

208

Fuzzy incremental control algorithm of loop heat pipe cooling system for spacecraft applications  

Science Conference Proceedings (OSTI)

Reliable and high precision thermal control technologies are essential for the safe flight of advanced spacecraft. A fuzzy incremental control strategy is proposed for control of an LHP space cooling system comprising a loop heat pipe and a variable ... Keywords: Fuzzy incremental control, Loop heat pipe, Modeling and simulation, Space cooling system

Su-Jun Dong; Yun-Ze Li; Jin Wang; Jun Wang

2012-09-01T23:59:59.000Z

209

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

210

Development of an air-cooled, loop-type heat pipe with multiple condensers  

E-Print Network (OSTI)

Thermal management challenges are prevalent in various applications ranging from consumer electronics to high performance computing systems. Heat pipes are capillary-pumped devices that take advantage of the latent heat ...

Kariya, H. Arthur (Harumichi Arthur)

2012-01-01T23:59:59.000Z

211

Development and analysis of sulfur based McGill heat pipe.  

E-Print Network (OSTI)

??The development of a mid-temperature range (250°C – 500°C) heat pipe for high heat flux applications has been the focus of numerous researchers during the last… (more)

Zhao, Hujun, 1972-

2007-01-01T23:59:59.000Z

212

Novel Charging Station and Computational Modeling for High Thermal Conductivity Heat Pipe Thermal Ground Planes.  

E-Print Network (OSTI)

??Thermal ground planes (TGPs) are planar, thin (thickness of 3 mm or less) heat pipes which use two-phase heat transfer. TGPs are innovative high-performance, integrated… (more)

Ababneh, Mohammed

2012-01-01T23:59:59.000Z

213

Modeling, Designing, Fabricating, and Testing of Channel Panel Flat Plate Heat Pipes.  

E-Print Network (OSTI)

??Flat plate heat pipes are very efficient passive two-phase heat transport devices. Their high e'ciency and low mass are desirable in the aerospace and electronics… (more)

Harris, James R

2008-01-01T23:59:59.000Z

214

Design, fabrication, and characterization of a multi-condenser loop heat pipe  

E-Print Network (OSTI)

A condenser design was characterized for a multi-condenser loop heat pipe (LHP) capable of dissipating 1000 W. The LHP was designed for integration into a high performance aircooled heat sink to address thermal management ...

Hanks, Daniel Frank

2012-01-01T23:59:59.000Z

215

Design and demonstration of a high-temperature, deployable, membrane heat-pipe radiator element  

SciTech Connect

Demonstration of a high-temperature, deployable, membrane heat-pipe radiator element has been conducted. Membrane heat pipes offer the potential for compact storage, ease of transportation, self-deployment, and a high specific radiator performance (kg/kW) for use in thermal reflection systems of space nuclear power plants. A demonstration heat pipe 8-cm wide and 100-cm long was fabricated. The heat pipe containment and wick structure were made of stainless steel and sodium used as the working fluid. The tests demonstrated passive deployment of the high-temperature membrane radiator, simulating a single segment in a flat array, at a temperature of 800 K. Details of test procedures and results of the tests are presented in this paper together with a discussion of the design and development of a full-scale, segmented high-temperature, deployable membrane heat pipe. 5 refs., 7 figs.

Trujillo, V.L.; Keddy, E.S.; Merrigan, M.A.

1989-01-01T23:59:59.000Z

216

An evaluation of the thermal characteristics of a flat plate heat pipe spreader  

E-Print Network (OSTI)

An evaluation of the thermal characteristics of a flat plate heat pipe spreader was performed through an analytical, numerical, and experimental analysis. The physical system considered was comprised of a high heat flux heat source attached to the center of a flat plate heat pipe, mounted at the base of a plate-finned heat sink and cooled by forced convection. In the analysis, the theoretical maximum operating conditions for the heat pipe are predicted, and it is found that the specific heat pipe configuration would most likely fail based on capillary limitations of the wick structure for conditions typical of electronic cooling applications. The mass and heat transfer processes which contribute to the capillary limitation were considered in theory, and a novel technique which utilizes well-known conventional heat pipe relations for pressure loss was developed to estimate the point of heat pipe failure. In addition, a thermal resistance network was developed in an effort to predict the temperature drop across the heat pipe spreader. Through a separate approach, a numerical model was developed to solve the conjugate problem of heat transfer in the heat pipe/heat sink with turbulent forced convection. In this approach, the heat pipe was modeled as a solid material having a high effective conductivity. Finally, the system was tested experimentally, and the results were compared to the analytical and numerical results. It was found that the capillary limit model over-predicted the measured point of heat pipe failure by several orders of magnitude, and the resistance model under-represented the actual resistance by a factor of 2 to 3. In addition, a change in thermal resistance with power input was discovered during experimentation that was not predicted by the analysis. The numerical model was compared to the experimental results and a relation for the effective conductivity as a function of power input was determined. Complexities associated with the internal heat and mass transfer processes of the flat plate heat pipe spreader were thoroughly discussed and the discrepancies between the experimental and analytical results were examined.

Chesser, Jason Blake

2000-01-01T23:59:59.000Z

217

Establishing low-power operating limits for liquid metal heat pipes  

SciTech Connect

Liquid metal heat pipes operated at power throughputs well below their design point for long durations may fail as a result of the working fluid migrating to a cold region within the pipe, freezing there, and hot returning to the evaporator section. Eventually sufficient working fluid inventory may be lost to the cold region to cause a local dry-out condition in the evaporator. A joint experimental and analytical effort between the Air Force Phillips Laboratory and Los Alamos National Laboratory is underway to investigate the phenomena. Experiments include both high temperature liquid metal and low temperature organic heat pipes. To date, a low temperature working fluid has been selected and its performance in a heat pipe validated. Additionally, a low-temperature heat pipe has been fabricated and is presently being tested.

Secary, J. (Phillips Lab., Kirtland AFB, NM (United States)); Merrigan, M.A.; Keddy, M.D. (Los Alamos National Lab., NM (United States))

1992-01-01T23:59:59.000Z

218

Establishing low-power operating limits for liquid metal heat pipes  

SciTech Connect

Liquid metal heat pipes operated at power throughputs well below their design point for long durations may fail as a result of the working fluid migrating to a cold region within the pipe, freezing there, and hot returning to the evaporator section. Eventually sufficient working fluid inventory may be lost to the cold region to cause a local dry-out condition in the evaporator. A joint experimental and analytical effort between the Air Force Phillips Laboratory and Los Alamos National Laboratory is underway to investigate the phenomena. Experiments include both high temperature liquid metal and low temperature organic heat pipes. To date, a low temperature working fluid has been selected and its performance in a heat pipe validated. Additionally, a low-temperature heat pipe has been fabricated and is presently being tested.

Secary, J. [Phillips Lab., Kirtland AFB, NM (United States); Merrigan, M.A.; Keddy, M.D. [Los Alamos National Lab., NM (United States)

1992-05-01T23:59:59.000Z

219

Performance of cross-cooled desiccant dehumidifiers  

DOE Green Energy (OSTI)

A cross-cooled silica gel desiccant dehumidifier model was designed, built and tested. The performance of the unit was studied as a function of inlet process stream dew point, process stream and cooling stream flowrates and regeneration stream temperature and dew point. The tests were also simulated by a computer program and were compared to the experimental results.

Mei, V.C.; Lavan, Z.

1980-01-01T23:59:59.000Z

220

Design considerations for a thermophotovoltaic energy converter using heat pipe radiators  

DOE Green Energy (OSTI)

The purpose of this paper is to discuss concepts for using high temperature heat pipes to transport energy from a heat source to a thermophotovoltaic (TPV) converter. Within the converter, the condenser portion of each heat pipe acts as a photon radiator, providing a radiant flux to adjacent TPV cells, which in turn create electricity. Using heat pipes in this way could help to increase the power output and the power density of TPV systems. TPV systems with radiator temperatures in the range of 1,500 K are expected to produce as much as 3.6 W/cm{sup 3} of heat exchanger volume at an efficiency of 20% or greater. Four different arrangements of heat pipe-TPV energy converters are considered. Performance and sizing calculations for each of the concepts are presented. Finally, concerns with this concept and issues which remain to be considered are discussed.

Ashcroft, J.; DePoy, D. [Lockheed Martin Corp., Schenectady, NY (United States)

1997-06-01T23:59:59.000Z

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


221

Operation characteristics of cylindrical miniature grooved heat pipe using aqueous CuO nanofluids  

Science Conference Proceedings (OSTI)

An experimental study was performed to investigate the operation characteristics of a cylindrical miniature grooved heat pipe using aqueous CuO nanofluid as the working fluid at some steady cooling conditions. The experiments were carried out under both the steady operation process and the unsteady startup process. The experiment results show that substituting the nanofluid for water as the working fluid can apparently improve the thermal performance of the heat pipe for steady operation. The total heat resistance and the maximum heat removal capacity of the heat pipe using nanofluids can maximally reduce by 50% and increase by 40% compared with that of the heat pipe using water, respectively. For unsteady startup process, substituting the nanofluid for water as the working fluid, cannot only improve the thermal performance, but also reduce significantly the startup time. (author)

Wang, Guo-Shan; Song, Bin; Liu, Zhen-Hua [School of Mechanical Engineering, Shanghai Jiaotong University, 200240 Shanghai (China)

2010-11-15T23:59:59.000Z

222

High Temperature Variable Conductance Heat Pipes for Radioisotope Stirling Systems  

SciTech Connect

In a Stirling radioisotope system, heat must continually be removed from the GPHS modules, to maintain the GPHS modules and surrounding insulation at acceptable temperatures. Normally, the Stirling converter provides this cooling. If the Stirling engine stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS, but also ending the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) is under development to allow multiple stops and restarts of the Stirling engine. The status of the ongoing effort in developing this technology is presented in this paper. An earlier, preliminary design had a radiator outside the Advanced Stirling Radioisotope Generator (ASRG) casing, used NaK as the working fluid, and had the reservoir located on the cold side adapter flange. The revised design has an internal radiator inside the casing, with the reservoir embedded inside the insulation. A large set of advantages are offered by this new design. In addition to reducing the overall size and mass of the VCHP, simplicity, compactness and easiness in assembling the VCHP with the ASRG are significantly enhanced. Also, the permanently elevated temperatures of the entire VCHP allows the change of the working fluid from a binary compound (NaK) to single compound (Na). The latter, by its properties, allows higher performance and further mass reduction of the system. Preliminary design and analysis shows an acceptable peak temperature of the ASRG case of 140 deg. C while the heat losses caused by the addition of the VCHP are 1.8 W.

Tarau, Calin; Walker, Kara L.; Anderson, William G. [Advanced Cooling Technologies, Inc. 1046 New Holland Ave. Lancaster, PA 17601 (United States)

2009-03-16T23:59:59.000Z

223

Analytical and experimental studies of heat pipe radiation cooling of hypersonic propulsion systems  

SciTech Connect

Preliminary, research-oriented, analytical and experimental studies were completed to assess the feasibility of using high-temperature heat pipes to cool hypersonic engine components. This new approach involves using heat pipes to transport heat away from the combustor, nozzle, or inlet regions, and to reject it to the environment by thermal radiation from an external heat pipe nacelle. For propulsion systems using heat pipe radiation cooling (HPRC), it is possible to continue to use hydrocarbon fuels into the Mach 4 to Mach 6 speed range, thereby enhancing the economic attractiveness of commercial or military hypersonic flight. In the second-phase feasibility program recently completed, we found that heat loads produced by considering both convection and radiation heat transfer from the combustion gas can be handled with HPRC design modifications. The application of thermal insulation to ramburner and nozzle walls was also found to reduce the heat load by about one-half and to reduce peak HPRC system temperatures to below 2700{degrees}F. In addition, the operation of HPRC at cruise conditions of around Mach 4.5 and at an altitude of 90, 000 ft lowers peak hot section temperatures to around 2800{degrees}F. An HPRC heat pipe was successfully fabricated and tested at Mach 5 conditions of heat flux, heat load, and temperature. 24 refs.

Martin, R.A.; Merrigan, M.A.; Elder, M.G.; Sena, J.T.; Keddy, E.S. (Los Alamos National Lab., NM (United States)); Silverstein, C.C. (CCS Associates, Bethel Park, PA (United States))

1992-01-01T23:59:59.000Z

224

Analytical and experimental studies of heat pipe radiation cooling of hypersonic propulsion systems  

SciTech Connect

Preliminary, research-oriented, analytical and experimental studies were completed to assess the feasibility of using high-temperature heat pipes to cool hypersonic engine components. This new approach involves using heat pipes to transport heat away from the combustor, nozzle, or inlet regions, and to reject it to the environment by thermal radiation from an external heat pipe nacelle. For propulsion systems using heat pipe radiation cooling (HPRC), it is possible to continue to use hydrocarbon fuels into the Mach 4 to Mach 6 speed range, thereby enhancing the economic attractiveness of commercial or military hypersonic flight. In the second-phase feasibility program recently completed, we found that heat loads produced by considering both convection and radiation heat transfer from the combustion gas can be handled with HPRC design modifications. The application of thermal insulation to ramburner and nozzle walls was also found to reduce the heat load by about one-half and to reduce peak HPRC system temperatures to below 2700{degrees}F. In addition, the operation of HPRC at cruise conditions of around Mach 4.5 and at an altitude of 90, 000 ft lowers peak hot section temperatures to around 2800{degrees}F. An HPRC heat pipe was successfully fabricated and tested at Mach 5 conditions of heat flux, heat load, and temperature. 24 refs.

Martin, R.A.; Merrigan, M.A.; Elder, M.G.; Sena, J.T.; Keddy, E.S. [Los Alamos National Lab., NM (United States); Silverstein, C.C. [CCS Associates, Bethel Park, PA (United States)

1992-06-01T23:59:59.000Z

225

Preliminary Heat Transfer Studies for the Double Shell Tanks (DST) Transfer Piping  

SciTech Connect

Heat transfer studies were made to determine the thermal characteristics of double-shell tank transfer piping under both transient and steady-state conditions. A number of design and operation options were evaluated for this piping system which is in its early design phase.

HECHT, S.L.

2000-02-15T23:59:59.000Z

226

Solar heat pipe testing of the Stirling thermal motors 4-120 Stirling engine  

DOE Green Energy (OSTI)

Stirling-cycle engines have been identified as a promising technology for the conversion of concentrated solar energy into usable electrical power. A 25kW electric system takes advantage of existing Stirling-cycle engines and existing parabolic concentrator designs. In previous work, the concentrated sunlight impinged directly on the heater head tubes of the Stirling Thermal Motors (STM) 4-120 engine. A Sandia-designed felt-metal-wick heat pipe receiver was fitted to the STM 4-120 engine for on-sun testing on Sandia`s Test Bed Solar Concentrator. The heat pipe uses sodium metal as an intermediate two-phase heat transfer fluid. The receiver replaces the directly-illuminated heater head previously tested. The heat pipe receiver provides heat isothermally to the engine, and the heater head tube length is reduced, both resulting in improved engine performance. The receiver also has less thermal losses than the tube receiver. The heat pipe receiver design is based on Sandia`s second-generation felt-wick heat pipe receiver. This paper presents the interface design, and compares the heat pipe/engine test results to those of the directly-illuminated receiver/engine package.

Andraka, C.E.; Rawlinson, K.S.; Moss, T.A.; Adkins, D.R.; Moreno, J.B.; Gallup, D.R.; Cordeiro, P.G. [Sandia National Labs., Albuquerque, NM (United States); Johansson, S. [Stirling Thermal Motors, Inc., Ann Arbor, MI (United States)

1996-07-01T23:59:59.000Z

227

Building, Testing, and Post Test Analysis of Durability Heat Pipe No.6  

DOE Green Energy (OSTI)

The Solar Thermal Program at Sandia supports work developing dish/Stirling systems to convert solar energy into electricity. Heat pipe technology is ideal for transferring the energy of concentrated sunlight from the parabolic dish concentrators to the Stirling engine heat tubes. Heat pipes can absorb the solar energy at non-uniform flux distributions and release this energy to the Stirling engine heater tubes at a very uniform flux distribution thus decoupling the design of the engine heater head from the solar absorber. The most important part of a heat pipe is the wick, which transports the sodium over the heated surface area. Bench scale heat pipes were designed and built to more economically, both in time and money, test different wicks and cleaning procedures. This report covers the building, testing, and post-test analysis of the sixth in a series of bench scale heat pipes. Durability heat pipe No.6 was built and tested to determine the effects of a high temperature bakeout, 950 C, on wick corrosion during long-term operation. Previous tests showed high levels of corrosion with low temperature bakeouts (650-700 C). Durability heat pipe No.5 had a high temperature bakeout and reflux cleaning and showed low levels of wick corrosion after long-term operation. After testing durability heat pipe No.6 for 5,003 hours at an operating temperature of 750 C, it showed low levels of wick corrosion. This test shows a high temperature bakeout alone will significantly reduce wick corrosion without the need for costly and time consuming reflux cleaning.

MOSS, TIMOTHY A.

2002-03-01T23:59:59.000Z

228

Hydrogen permeation resistant heat pipe for bi-modal reactors. Final report, October 1, 1994--September 30, 1995  

DOE Green Energy (OSTI)

The principal objective of this program was to demonstrate technology that will make a sodium heat pipe tolerant of hydrogen permeation for a bimodal space reactor application. Special focus was placed on techniques which enhance the permeation of hydrogen out of the heat pipe. Specific objectives include: define the detailed requirements for the bimodal reactor application; design and fabricate a prototype heat pipe tolerant of hydrogen permeation; and test the prototype heat pipe and demonstrate that hydrogen which permeates into the heat pipe is removed or reduced to acceptable levels. The results of the program were fully successful. Analyses were performed on two different heat pipe designs and an experimental heat pipe was fabricated and tested. A model of the experimental heat pipe was developed to predict the enhancement in the hydrogen permeation rate out of the heat pipe. A significant improvement in the rate at which hydrogen permeates out of a heat pipe was predicted for the use of the special condenser geometry developed here. Agreement between the model and the experimental results was qualitatively good. Inclusion of the additional effects of fluid flow in the heat pipe are recommended for future work.

North, M.T.; Anderson, W.G.

1995-12-31T23:59:59.000Z

229

Water-Heating Dehumidifier - Energy Innovation Portal  

Hydrogen and Fuel Cell; Hydropower, Wave and Tidal; Industrial Technologies; Solar ... When the tank of water heater is full of hot water or a ...

230

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

231

Testing of advanced ceramic fabric heat pipe for a Stirling engine  

SciTech Connect

The development and application of Stirling engines for space power production requires concomitant development of an advanced heat rejection system. We are currently involved in the design, development, and testing of advanced ceramic fabric (ACF) water heat pipes for optimal heat rejection from the Stirling cycle without the use of hazardous working fluids such as mercury. Our testing to-date has been with a 200-{mu}m thick titanium heat pipe utilizing Nextel {trademark} fabric as both the outer structural component and as a wick. This heat pipe has been successfully started up from a frozen condition against a negative 4 degree tilt (i.e., fluid return to evaporator was against gravity), with 75 W heat input, in ambient air. In a horizontal orientation, up to 100 W heat input was tolerated without experiencing dryout. 7 refs., 5 figs., 2 tabs.

Antoniak, Z.I.; Webb, B.J.; Bates, J.M.

1991-09-01T23:59:59.000Z

232

Low Cost High Performance Generator Technology Program. Volume 5. Heat Pipe Topical  

DOE Green Energy (OSTI)

Research progress towards the development of a heat pipe for use in the Low Cost High Performance Thermoelectric Generator Program is reported for the period May 15, 1975 through June 1975. (TFD)

Not Available

1975-07-01T23:59:59.000Z

233

TURBULENT EXCHANGE OF MOMENTUM, MASS, AND HEAT BETWEEN FLUID STREAMS AND PIPE WALL  

SciTech Connect

S>A new correlation is presented to describe mass and heat transfer to a fluid in a fully developed turbulent flow in a pipe. The correlation differs from earlier empirical relations in that it is based on a theoretical continuous eddy-viscosity distribution from the wall to the center of the pipe. Transfer rates calculated from the new correlation are in excellent agree ment with experimental data on mass and heat transfer to fluid streams. (auth)

Wasan, D.T.; Wilke, C.R.

1963-03-01T23:59:59.000Z

234

Development of an integrated heat pipe-thermal storage system for a solar receiver  

SciTech Connect

The Organic Rankine Cycle (ORC) Solar Dynamic Power System (SDPS) is one of the candidates for Space Station prime power application. In the low earth orbit of the Space Station approximately 34 minutes of the 94-minute orbital period is spent in eclipse with no solar energy input to the power system. For this period the SDPS will use thermal energy storage (TES) material to provide a constant power output. Sundstrand Corporation is developing a ORC-SDPS candidate for the Space Station that uses toluene as the organic fluid and LiOH as the TES material. An integrated heat-pipe thermal storage receiver system is being developed as part of the ORC-SDPS solar receiver. This system incorporates potassium heat pipe elements to absorb and transfer the solar energy within the receiver cavity. The heat pipes contain the TES canisters within the potassium vapor space with the 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 heat pipe in the ORC-SDPS receiver cavity. The heat pipe transforms the non-uniform solar flux incident in the heat pipe surface within the receiver cavity to an essentially uniform flux at the potassium vapor condensation interface in the heat pipe. During solar insolation, 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 balance stored in the TES units is transferred by the potassium vapor to the toluene heater tube. 3 refs., 8 figs.

Keddy, E.S.; Sena, J.T.; Merrigan, M.A.; Heidenreich, G.; Johnson, S.

1987-01-01T23:59:59.000Z

235

Evacuated tubular collector utilizing a heat pipe. Final report, August 1-September 30, 1977  

SciTech Connect

The evaluation of three evacuated tubular solar collector designs is reported: heat pipe cusp; counter flow cusp; and counter flow/flat plate. Comparative field testing of 4' x 4' modules was completed for all three designs. Thermal analysis of data shows that the evacuated heat pipe/cusp collector is a viable concept, more suitable for medium to high temperatures and high solar flux intensities.

Ortabasi, U.

1977-01-01T23:59:59.000Z

236

Evacuated tubular collector utilizing a heat pipe. Final report, August 1-September 30, 1977  

DOE Green Energy (OSTI)

The evaluation of three evacuated tubular solar collector designs is reported: heat pipe cusp; counter flow cusp; and counter flow/flat plate. Comparative field testing of 4' x 4' modules was completed for all three designs. Thermal analysis of data shows that the evacuated heat pipe/cusp collector is a viable concept, more suitable for medium to high temperatures and high solar flux intensities.

Ortabasi, U.

1977-01-01T23:59:59.000Z

237

Development and extended operation of a high power radiation loaded heat pipe  

SciTech Connect

A high temperature, high power molybdenum-lithium heat pipe has been fabricated and tested at 1500 K for 1700 hours with radiant heat rejection. Power throughput during the test was approximately 14 kW, corresponding to an axial flux density of 11 kW/cm/sup 2/ for the 1.59 cm diameter heat pipe. Radial flux density was 70 W/cm/sup 2/ over an evaporator length of 40.0 cm. Condenser length was approximately 150 cm with radiant heat rejection from the condenser to a coaxial water cooled radiation calorimeter. A plasma sprayed, high emissivity coating was used on the condenser surface to increase the radiant heat rejection during the tests. The heat pipe was operated for 514 hours at steady state conditions before being damaged during a planned shutdown for test equipment maintenance. The damage was repaired and the initial 1000 hour test period completed without further incident. After physical examination of the heat pipe at 1000 hours the test was resumed and the heat pipe operated at the same conditions for an additional 700 hours before conclusion of this test phase.

Merrigan, M.A.; Keddy, E.S.; Runyan, J.R.; Martinez, H.E.

1984-06-01T23:59:59.000Z

238

Solar test of an integrated sodium reflux heat pipe receiver/reactor for thermochemical energy transport  

DOE Green Energy (OSTI)

A chemical reactor for carbon dioxide reforming of methane was integrated into a sodium reflux heat pipe receiver and tested in the solar furnace of the Weizmann Institute of Science, Rehovot, Israel. The receiver/reactor was a heat pipe with seven tubes inside an evacuated metal box containing sodium. The catalyst, 0.5 wt% Rh on alumina, filled two of the tubes with the front surface of the box serving as the solar absorber. In operation, concentrated sunlight heated the front plate and vaporized sodium from a wire mesh wick attached to other side. Sodium vapor condensed on the reactor tubes, releasing latent heat and returning to the wick by gravity. The receiver system performed satisfactorily in many tests under varying flow conditions. The maximum power absorbed was 7.5 kW at temperatures above 800C. The feasibility of operating a heat pipe receiver/reactor under solar conditions was proven, and the advantages of reflux devices confirmed.

Diver, R.B.; Fish, J.D. (Sandia National Labs., Albuquerque, NM (United States)); Levitan, R.; Levy, M.; Meirovitch, E.; Rosin, H. (Weizmann Inst. of Science, Rehovot (Israel)); Paripatyadar, S.A.; Richardson, J.T. (Univ. of Houston, TX (United States))

1992-01-01T23:59:59.000Z

239

A transient heat pipe model for a multimegawatt space power application  

SciTech Connect

The Argonne ''Monolithic Solid Oxide Fuel Cell'' power generation system has been described previously. In a ''burst power'' generation mode, hundreds of megawatts of DC power would be generated for a finite time interval. An accompanying nuclear power generation system would be used to regenerate the spent reactants (hydrogen and oxygen) in this closed system for subsequent re-use. Although the Argonne space power supply was designed to be a closed system in terms of material effluents, it had to reject the waste heat from the fuel cells (which operate with approximately 70% conversion efficiency). The heat rejection method included multiple heat pipes operated in parallel to convey thermal energy from the fuel cell coolant for ultimate radiation-rejection to space. These individual heat pipes featured a convectively heated evaporator section, an adiabatic section leading out from the fuel cell chamber to space, and the condenser section radiating to space. The transient behavior of these heat rejection heat pipes was not considered previously. This paper addresses the problem, showing that the heat pipes as conceptually designed also satisfy the stringent transient power generation---heat rejection requirements of the multimegawatt power generation system. 4 refs., 4 figs.

Carlson, L.W.

1989-01-01T23:59:59.000Z

240

Design and testing a solar cooling system employing liquid desiccants: Dehumidifier experiments in Colorado State University Solar House II: Final report, 1986--1987  

DOE Green Energy (OSTI)

A nominal 3-ton (10.5-kW) lithium bromide, open-cycle desiccant cooling system has been designed, installed, and operated. This experimental system dehumidifies ambient air in a packed bed utilizing an aqueous solution of lithium bromide. The absorbent solution is distributed by spray nozzles and flows countercurrent to the air. The dilute solution exiting the dehumidifier is concentrated in a packed bed regenerator by solar heated air. The strong solution is cooled by two heat exchangers before reentering the dehumidifier. Provisions to simulate conditions of high ambient humidity and temperature have been made. Experiments on the dehumidifier operating in a decoupled mode (without countercurrent regenerator operation) have been carried out. Cooling capacities in the range of 1.0--4.0 refrigeration tons have been achieved, depending upon the operating conditions. The effect of different independent variables on the capacity of the dehumidifier has been studied. An empirical equation correlating the variables have been obtained by statistical analysis of the data. The equation obtained indicates that the capacity of the dehumidifier depends strongly on the solution concentration, solution flow rate, air inlet temperature and the air humidity. Two other variables studied, the solution inlet temperature and the air flow rate, did not affect the cooling capacity greatly. The dependence of condensation rate on each of the variables is analyzed. 22 refs., 17 figs., 3 tabs.

Lenz, T.G.; Loef, G.O.G.; Patnaik, S.

1987-12-01T23:59:59.000Z

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


241

Heat-pipe effect on the transport of gaseous radionuclides released from a nuclear waste container  

SciTech Connect

When an unsaturated porous medium is subjected to a temperature gradient and the temperature is sufficiently high, vadose water is heated and vaporizes. Vapor flows under its pressure gradient towards colder regions where it condenses. Vaporization and condensation produce a liquid saturation gradient, creating a capillary pressure gradient inside the porous medium. Condensate flows towards the hot end under the influence of a capillary pressure gradient. This is a heat pipe in an unsaturated porous medium. We study analytically the transport of gaseous species released from a spent-fuel waste package, as affected by a time-dependent heat pipe in an unsaturated rock. For parameter values typical of a potential repository in partially saturated fractured tuff at Yucca Mountain, we found that a heat pipe develops shortly after waste is buried, and the heat-pipe`s spatial extent is time-dependent. Water vapor movements produced by the heat pipe can significantly affect the migration of gaseous radionuclides. 12 refs., 6 figs., 1 tab.

Zhou, W.; Chambre, P.L.; Pigford, T.H.; Lee, W.W.L.

1990-11-01T23:59:59.000Z

242

Pressure recovery in a cylindrical heat pipe at high radial Reynolds numbers and at high Mach numbers  

SciTech Connect

The pressure recovery in a cylindrical heat pipe has been investigated. The experiments cover average radial Reynolds numbers between 5 and 150 and average Mach numbers up to the velocity of sound. During preliminary experiments in a cylindrical, gravity-assisted heat pipe at high Mach numbers large condensate flow instabilities were observed. As a consequence the heat pipe power varied strongly. Based on these observations an improved heat pipe design was made that resulted in steady operating conditions throughout the entire parameter range. This heat pipe is described. The pressure recovery was measured and compared with results from a two-dimensional analytical model for describing compressible vapor flow in heat pipes. Good agreement with the experimental data was found.

Haug, F.; Busse, C.A.

1985-01-01T23:59:59.000Z

243

Heat pipes applied to flat-plate solar collectors. Final report  

SciTech Connect

The objective of this program was to analytically and experimentally investigate the use of heat pipes in flat-plate solar collectors. Heat pipes are passive heat transport devices which utilize a closed evaporation-condensation cycle. Because of their high equivalent conductance, they appear to be well suited to transport heat from the solar absorber to an air or liquid distribution system. The program consisted of the following tasks: (I) Configuration Studies, (II) Parametric Performance Studies, (III) Economic Analysis, (IV) System Integration Studies, (V) Submodule Fabrication and Testing (in the laboratory), and (VI) Full-Scale Module Fabrication and Testing (using solar input). An additional Task VII, Feasibility Study of a Stationary Concentrator, was identified during the program and was also completed. In performing Tasks I through IV, various aspects of integrating heat pipes into flat-palte solar collectors were investigated. The results of these tasks were reported in the Annual Progress Report (Ref. 2) dated January 31, 1975. A summary of that program effort is included in the present report. The results of the experimental work conducted under Tasks V and VI are presented in this report. Under Task V, breadboard heat pipes were fabricated from sections of Roll-Bond panels and their heat transfer performance was evaluated in the laboratory. Three complete solar panels, two of which were heat pipe absorbers and one was a Roll-Bond control panel, were fabricated and solar tested during Task VI. Finally, under the new Task VII, a feasibility study of a stationary concentrator using heat pipes as thermal diodes was conducted. Results are presented and discussed.

Bienert, W.B.; Wolf, D.A.

1976-05-01T23:59:59.000Z

244

Optimizing the heat pipe for operation in a magnetic field when liquid-metal working fluids are used  

SciTech Connect

A novel method for reducing the magnetohydrodynamic (MHD) pressure drops in the liquid metal flow in a heat pipe wick is described. By flattening the heat pipe, the eddy current return path in the metallic heat pipe wall is inreased significantly, thereby increasing the effective wall resistance. This, in turn, reduces the magnitude of the MHD pressure drop. The same principle can also be applied to flows of liquid metal coolants in a magnetic field.

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

1981-05-18T23:59:59.000Z

245

Thermal Analysis and Stress Analysis of the Heat-Exchange Pipe Based on ANSYS  

Science Conference Proceedings (OSTI)

ANSYS to be as a finite element analysis software has powerful features in thermal analysis and structural analysis. Based on ANSYS thermal analysis function, this paper selects SOLID90 unit, for thermal analysis on the heat-exchange pipe of heat exchanger ... Keywords: ANSYS, temperature distribution, stress distribution

Fenhua Li; Jian Xing; Yuan Liu

2011-04-01T23:59:59.000Z

246

Cost-effective solar collectors using heat pipes. Interim progress report No. 3, October 1978-June 1979  

SciTech Connect

The heat pipe collector system design was re-evaluated as a new system, as compared to previous evaluation where the heat pipe was an interchangeable component in the standard TC-101 system. Collector hardware components were finalized, including production costs. Heat pipe fluid-vessel testing continued indoors and outdoors in the solar panel. A prototpe production processing station has been designed which shows that the labor content of processing individual heat pipes can be reduced to 15 seconds with a total cost of $1.50.

Ernst, D.M.

1979-01-01T23:59:59.000Z

247

Insoluble coatings for Stirling engine heat pipe condenser surfaces. Final report  

Science Conference Proceedings (OSTI)

The work done by Thermacore, Inc., Lancaster, Pennsylvania, for the Phase 1, 1992 SBIR National Aeronautics and Space Administration Contract, Insoluble Coatings for Stirling Engine Heat Pipe Condenser Surfaces' is described. The work was performed between January 1992 and July 1992. Stirling heat engines are being developed for electrical power generation use on manned and unmanned earth orbital and planetary missions. Dish Stirling solar systems and nuclear reactor Stirling systems are two of the most promising applications of the Stirling engine electrical power generation technology. The sources of thermal energy used to drive the Stirling engine typically are non-uniform in temperature and heat flux. Liquid metal heat pipe receivers are used as thermal transformers and isothermalizers to deliver the thermal energy at a uniform high temperature to the heat input section of the Stirling engine. The use of a heat pipe receiver greatly enhances system efficiency and potential life span. One issue that is raised during the design phase of heat pipe receivers is the potential solubility corrosion of the Stirling engine heat input section by the liquid metal working fluid. This Phase 1 effort initiated a program to evaluate and demonstrate coatings, applied to nickel based Stirling engine heater head materials, that are practically 'insoluble' in sodium, potassium, and NaK. This program initiated a study of nickel aluminide as a coating and developed and demonstrated a heat pipe test vehicle that can be used to test candidate materials and coatings. Nickel 200 and nickel aluminide coated Nickel 200 were tested for 1000 hours at 800 C at a condensation heat flux of 25 W/sq cm. Subsequent analyses of the samples showed no visible sign of solubility corrosion of either coated or uncoated samples. The analysis technique, photomicrographs at 200X, has a resolution of better than 2.5 microns (.0001 in).

Dussinger, P.M.

1993-09-01T23:59:59.000Z

248

Mass transport, corrosion, plugging, and their reduction in solar dish/Stirling heat pipe receivers  

DOE Green Energy (OSTI)

Solar dish/Stirling systems using sodium heat pipe receivers are being developed by industry and government laboratories here and abroad. The unique demands of this application lead to heat pipe wicks with very large surface areas and complex three-dimensional flow patterns. These characteristics can enhance the mass transport and concentration of constituents of the wick material, resulting in wick corrosion and plugging. As the test times for heat pipe receivers lengthen, we are beginning to see these effects both indirectly, as they affect performance, and directly in post-test examinations. We are also beginning to develop corrective measures. In this paper, we report on our test experiences, our post-test examinations, and on our initial effort to ameliorate various problems.

Adkins, D.R.; Andraka, C.E.; Bradshaw, R.W.; Goods, S.H.; Moreno, J.B.; Moss, T.A.

1996-07-01T23:59:59.000Z

249

Performance Analysis of Potassium Heat Pipes Radiator for HP-STMCs Space Reactor Power System  

SciTech Connect

A detailed design and performance results of C-C finned, and armored potassium heat pipes radiator for a 110 kWe Heat Pipes-Segmented Thermoelectric Module Converters (HP-STMCs) Space Reactor Power system (SRPS) are presented. The radiator consists of two sections; each serves an equal number of STMCs and has 162 longitudinal potassium heat pipes with 0.508 mm thick C-C fins. The width of the C-C fins at the minor diameter of the radiator is almost zero, but increases with distance along the radiator to reach 3.7 cm at the radiator's major diameter. The radiator's heat pipes (OD = 2.42 cm in front and 3.03 cm in rear) have thin titanium (0.0762 mm thick) liners and wicks (0.20 mm thick with an effective pore radius of 12-16 {mu}m) and a 1.016 mm thick C-C wall. The wick is separated from the titanium liner by a 0.4 mm annulus filled with liquid potassium to increase the capillary limit. The outer surfaces of the heat pipes in the front and rear sections of the radiator are protected with a C-C armor that is 2.17 mm and 1.70 mm thick, respectively. The inside surface of the heat pipes in the front radiator is thermally insulated while the C-C finned condensers of the rear heat pipes are exposed, radiating into space through the rear opening of the radiator cavity. The heat pipes in both the front and the rear radiators have a 1.5 m long evaporator section and each dissipates 4.47 kW while operating at 43.6% of the prevailing sonic limit. The front and rear radiator sections are 5.29 m and 2.61 m long with outer surface area and mass of 47.1 m2 and 314.3 kg, and 39.9 m2 and 243.2 kg, respectively. The total radiator is 7.63 m long and has minor and major diameters of 1.48 m and 5.57 m, respectively, and a total surface area of 87 m2; however, the effective radiator area, after accounting for heat rejection through the rear of the radiator cavity, is 98.8 m2. The radiator's total mass including the C-C armor is 557.5 kg and the specific area and specific mass are 6.41 kg/m2 and 5.07 kg/kWe, respectively.

El-Genk, Mohamed S.; Tournier, Jean-Michel [Institute for Space and Nuclear Power Studies, University of New Mexico, Albuquerque, NM, 87131 (United States); Chemical and Nuclear Engineering Dept., University of New Mexico, Albuquerque, NM, 87131 (United States)

2004-02-04T23:59:59.000Z

250

Heat pipe cooled reactors for multi-kilowatt space power supplies  

SciTech Connect

Three nuclear reactor space power system designs are described that demonstrate how the use of high temperature heat pipes for reactor heat transport, combined with direct conversion of heat to electricity, can result in eliminating pumped heat transport loops for both primary reactor cooling and heat rejection. The result is a significant reduction in system complexity that leads to very low mass systems with high reliability, especially in the power range of 1 to 20 kWe. In addition to removing heat exchangers, electromagnetic pumps, and coolant expansion chambers, the heat pipe/direct conversion combination provides such capabilities as startup from the frozen state, automatic rejection of reactor decay heat in the event of emergency or accidental reactor shutdown, and the elimination of single point failures in the reactor cooling system. The power system designs described include a thermoelectric system that can produce 1 to 2 kWe, a bimodal modification of this system to increase its power level to 5 kWe and incorporate high temperature hydrogen propulsion capability, and a moderated thermionic reactor concept with 5 to 20 kWe power output that is based on beryllium modules that thermally couple cylindrical thermionic fuel elements (TFEs) to radiator heat pipes.

Ranken, W.A.; Houts, M.G.

1995-01-01T23:59:59.000Z

251

Optimal insulation of pipes and tanks for solar heating systems. Topical report  

DOE Green Energy (OSTI)

A compact and time effective insulation design procedure for solar heating system piping and water-filled thermal storage tanks was developed. Recognizing the particular sensitivity of solar systems to cost, the economic aspect of the problem is treated by a comprehensive present-value life-cycle cost analysis. In the development of the method, a numerical sensitivity analysis was performed to determine the relative effects of all relevant independent variables (within their pertinent ranges) on piping and tank heat transfer coefficient values.

Jones, G F; Lior, N

1979-02-01T23:59:59.000Z

252

Heat transfer performance of an external receiver pipe under unilateral concentrated solar radiation  

Science Conference Proceedings (OSTI)

The heat transfer and absorption characteristics of an external receiver pipe under unilateral concentrated solar radiation are theoretically investigated. Since the heat loss ratio of the infrared radiation has maximum at moderate energy flux, the heat absorption efficiency will first increase and then decrease with the incident energy flux. The local absorption efficiency will increase with the flow velocity, while the wall temperature drops quickly. Because of the unilateral concentrated solar radiation and different incident angle, the heat transfer is uneven along the circumference. Near the perpendicularly incident region, the wall temperature and absorption efficiency slowly approaches to the maximum, while the absorption efficiency sharply drops near the parallelly incident region. The calculation results show that the heat transfer parameters calculated from the average incident energy flux have a good agreement with the average values of the circumference under different boundary conditions. For the whole pipe with coating of Pyromark, the absorption efficiency of the main region is above 85%, and only the absorption efficiency near the parallelly incident region is below 80%. In general, the absorption efficiency of the whole pipe increases with flow velocity rising and pipe length decreasing, and it approaches to the maximum at optimal concentrated solar flux. (author)

Jianfeng, Lu; Jing, Ding [School of Engineering, Sun Yat-Sen University, Guangzhou 510006 (China); Jianping, Yang [Key Laboratory of Enhanced Heat Transfer and Energy Conservation of the Ministry of Education, South China University of Technology, Guangzhou 510640 (China)

2010-11-15T23:59:59.000Z

253

STUDY OF TRANSIENT BEHAVIOR OF THE EVAPORATOR OF THE MICRO LOOP HEAT PIPE AND MODIFICATIONS TO THE EXISTING GLOBAL MODEL.  

E-Print Network (OSTI)

??The Micro Loop Heat Pipe (ìLHP) is a self-circulating cooling device with extremely high thermal conductivity where heat is removed by phase change and the… (more)

PONUGOTI, PRIYANKA

2006-01-01T23:59:59.000Z

254

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

255

Performance demonstration of a high-power space-reactor heat-pipe design  

SciTech Connect

Performance of a 15.9-mm diam, 2-m long, artery heat pipe has been demonstrated at power levels to 22.6 kW and temperatures to 1500/sup 0/K. The heat pipe employed lithium as a working fluid with distribution wicks and arteries fabricated from 400 mesh Mo-41 wt % Re screen. Molybdenum alloy (TZM) was used for the container. Peak axial power density attained in the testing was 19 kW/cm/sup 2/ at 1465/sup 0/K. The corresponding radial flux density in the evaporator region of the heat pipe was 150 W/cm/sup 2/. The extrapolated limit for the heat pipe at its 1500/sup 0/K design point is 30 kW, corresponding to an axial flux density of 25 kW/cm/sup 2/. Sonic and capillary limits for the design were investigated in the 1100 to 1500/sup 0/K temperature range. Excellent agreement of measured and predicted temperature and power levels was observed.

Merrigan, M.A.; Martinez, E.H.; Keddy, E.S.; Runyan, J.; Kemme, J.E.

1983-01-01T23:59:59.000Z

256

Experimental Research of the Falling-Film Evaporation Characteristic outside Horizontal Heat Pipe in the Vacuum  

Science Conference Proceedings (OSTI)

Face the energy crisis in the world, it is important to improve the utilization efficiency of the energy conversion. The evaporation characteristic of the falling film outside heat pipe in the vacuum as a good evaporation method was studied in the paper. ... Keywords: Falling film, Evaporation, Vacuum

Penghui Gao; Lixi Zhang; Hefei Zhang

2009-10-01T23:59:59.000Z

257

Entirely passive heat-pipe apparatus capable of operating against gravity  

DOE Patents (OSTI)

The disclosure is directed to an entirely passive heat pipe apparatus capable of operating against gravity for vertical distances in the order of 3 to 7 and more. A return conduit into which an inert gas is introduced is used to lower the specific density of the working fluid so that it may be returned a greater vertical distance from condenser to evaporator.

Koenig, D.R.

1981-02-11T23:59:59.000Z

258

Design studies of the Moderated Thermonic Heat Pipe Reactor (MOHTR) concept  

DOE Green Energy (OSTI)

Design studies, based primarily on neutronics analysis, have been conducted on a thermionic reactor concept that uses a combined beryllium and zirconium hydride moderator to facilitate the incorporation of heat pipe cooling into compact thermionic fuel element (TFE) based designs useful in the tens of kilowatts electrical power regime. The goal of the design approach is to achieve a single point failure free system with technologies such as TFEs, high-temperature heat pipes, and ZrH moderation, which have extensive test data bases and have been shown to be capable of long lifetimes. Beryllium is used to thermally couple redundant heat pipes to TFEs and ZrH is added to reduce critical size. Neutronic analysis undertaken to investigate this design approach shows that greater reactivity can be achieved for a given geometry with a combination of the two moderator materials than with ZrH alone and that the combined moderator is much less sensitive to hydrogen loss than more traditional ZrH-moderated thermionic reactor designs. These and other analytical approaches have demonstrated the credibility of a heat pipe cooled thermionic reactor concept that has a reactor height and diameter of 60 cm and a reactor mass of 400 kg for 30-kWe power output. 14 refs., 8 figs.

Ranken, W.A.; Turner, J.A.

1991-01-01T23:59:59.000Z

259

Optimization of the configuration and working fluid for a micro heat pipe thermal control device  

E-Print Network (OSTI)

Continued development of highly compact and powerful electronic components has led to the need for a simple and effective method for controlling the thermal characteristics of these devices. One proposed method for thermal control involves the use of a micro heat pipe system containing a working fluid with physical properties having been speciffcally selected such that the heat pipes, as a whole, vary in effective thermal conductance, thereby providing a level of temperature regulation. To further explore this possibility, a design scenario with appropriate constraints was established and a model developed to solve for the effective thermal conductance of individual heat pipes as a function of evaporator-end temperature. From the results of this analysis, several working fluids were identified and selected from a list over thirteen hundred that were initially analyzed. Next, a thermal circuit model was developed that translated the individual heat pipe operating characteristics into the system as a whole to determine the system level effects. It was found that none of the prospective fluids could completely satisfy the established design requirements to regulate the device temperature over the entire range of operating conditions. This failure to fully satisfy design requirements was due, in large part, to the highly constrained nature of problem definition. Several fluids, however, did provide for an improved level of thermal control when compared to the unmodified design. Suggestions for improvements that may lead to enhanced levels of thermal control are offered as well as areas that are in need of further research.

Coughlin, Scott Joseph

2005-12-01T23:59:59.000Z

260

Development of a solar desiccant dehumidifier. Third technical progress report  

DOE Green Energy (OSTI)

This program is aimed at the development of a solar desiccant dehumidifier featuring a rotary bed of granular silica gel and a rotary regenerator. Design, fabrication, performance, commercialization studies, and test stand development are described in detail. (WHK)

Gunderson, M.E.

1979-06-12T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Closed loop pulsating heat pipes Part A: parametric experimental investigations  

E-Print Network (OSTI)

(constant vol- ume), two-phase, bubble­liquid slug system formed inside the tube-bundle due to the dominance of surface tension forces. This tube-bundle receives heat at one end and is cooled at the other. Temperature-hydrodynamic coupling of pressure/temperature fluctuations with the void fraction (mal-) distribution. This causes heat

Khandekar, Sameer

262

Thermal Analysis of the Divertor Primary Heat Transfer System Piping During the Gas Baking Process  

SciTech Connect

A preliminary analysis has been performed examining the temperature distribution in the Divertor Primary Heat Transfer System (PHTS) piping and the divertor itself during the gas baking process. During gas baking, it is required that the divertor reach a temperature of 350 C. Thermal losses in the piping and from the divertor itself require that the gas supply temperature be maintained above that temperature in order to ensure that all of the divertor components reach the required temperature. The analysis described in this report was conducted in order to estimate the required supply temperature from the gas heater.

Yoder Jr, Graydon L [ORNL; Harvey, Karen [ORNL; Ferrada, Juan J [ORNL

2011-02-01T23:59:59.000Z

263

Selenide isotope generator for the Galileo Mission: copper/water axially-grooved heat pipe topical report  

SciTech Connect

This report presents a summary of the major accomplishments for the development, fabrication, and testing of axially-grooved copper/water heat pipes for Selenide Isotopic Generator (SIG) applications. The early development consisted of chemical, physical, and analytical studies to define an axially-grooved tube geometry that could be successfully fabricated and provide the desired long term (up to seven years) performance is presented. Heat pipe fabrication procedures, measured performance and accelerated life testing of heat pipes S/Ns AL-5 and LT-57 conducted at B and K Engineering are discussed. S/N AL-5 was the first axially-grooved copper/water heat pipe that was fabricated with the new internal coating process for cupric oxide (CuO) and the cleaning and water preparation methods developed by Battelle Columbus Laboratories. Heat pipe S/N LT-57 was fabricated along with sixty other axially-grooved heat pipes allocated for life testing at Teledyne Energy Systems. As of June 25, 1979, heat pipes S/Ns AL-5 and LT-57 have been accelerated life tested for 13,310 and 6,292 respectively, at a nominal operating temperature of 225/sup 0/C without any signs of thermal performance degradation. (TFD)

Strazza, N.P.

1979-06-30T23:59:59.000Z

264

Development and test of a space-reactor-core heat pipe  

SciTech Connect

A heat pipe designed to meet the heat transfer requirements of a 100-kW/sub e/ space nuclear power system has been developed and tested. General design requirements for the device included an operating temperature of 1500/sup 0/K with an evaporator radial flux density of 100 w/cm/sup 2/. The total heat-pipe length of 2 m comprised an evaporator length of 0.3 m, a 1.2-m adiabatic section, and a condenser length of 0.5 m. A four-artery design employing screen arteries and distribution wicks was used with lithium serving as the working fluid. Molybdenum alloys were used for the screen materials and tube shell. Hafnium and zirconium gettering materials were used in connection with a pre-purified distilled lithium charge to ensure internal chemical compatibility. After initial performance verification, the 14.1-mm i.d. heat pipe was operated at 15 kW throughput at 1500/sup 0/K for 100 hours. No performance degradation was observed during the test.

Merrigan, M.A.; Runyan, J.E.; Martinez, H.E.; Keddy, E.S.

1983-01-01T23:59:59.000Z

265

Heat pipe radiation cooling (HPRC) for high-speed aircraft propulsion. Phase 2 (feasibility) final report  

DOE Green Energy (OSTI)

The National Aeronautics and Space Administration (NASA), Los Alamos National Laboratory (Los Alamos), and CCS Associates are conducting the Heat Pipe Radiation Cooling (HPRC) for High-Speed Aircraft Propulsion program to determine the advantages and demonstrate the feasibility of using high-temperature heat pipes to cool hypersonic engine components. This innovative approach involves using heat pipes to transport heat away from the combustor, nozzle, or inlet regions, and to reject it to the environment by thermal radiation from adjacent external surfaces. HPRC is viewed as an alternative (or complementary) cooling technique to the use of pumped cryogenic or endothermic fuels to provide regenerative fuel or air cooling of the hot surfaces. The HPRC program has been conducted through two phases, an applications phase and a feasibility phase. The applications program (Phase 1) included concept and assessment analyses using hypersonic engine data obtained from US engine company contacts. The applications phase culminated with planning for experimental verification of the HPRC concept to be pursued in a feasibility program. The feasibility program (Phase 2), recently completed and summarized in this report, involved both analytical and experimental studies.

Martin, R.A.; Merrigan, M.A.; Elder, M.G.; Sena, J.T.; Keddy, E.S. [Los Alamos National Lab., NM (United States); Silverstein, C.C. [CCS Associates, Bethel Park, PA (United States)

1994-03-25T23:59:59.000Z

266

Construction and testing of ceramic fabric heat pipe with water working fluid  

SciTech Connect

A prototype ceramic fabric/titanium water heat pipe has been constructed and tested; it transported 25 to 80 W of power at 423 K. Component development and testing is continuing with the aim of providing an improved prototype, with a 38-{mu}m stainless steel linear covered by a biaxially-braided Nextel (trademark of the 3M Co., St. Paul Minnesota) sleeve that is approximately 300-{mu}m thick. This fabric has been tested to 800 K, and its emittance is about 0.5 at that temperature. Advanced versions of the water heat pipe will probably require a coating over the ceramic fabric in order to increase this emittance to the 0.8 to 0.9 range. 2 refs., 3 figs., 1 tab.

Antoniak, Z.I.; Webb, B.J.; Bates, J.M.; Cooper, M.F.

1991-01-01T23:59:59.000Z

267

Mathematical modeling and analysis of heat pipe start-up from the frozen state  

SciTech Connect

The start-up process of a frozen heat pipe is described and a complete mathematical model for the start-up of the frozen heat pipe is developed based on the existing experimental data, which is simplified and solved numerically. The two-dimensional transient model for the wall and wick is coupled with the one-dimensional transient model for the vapor flow when vaporization and condensation occur at the interface. A parametric study is performed to examine the effect of the boundary specification at the surface of the outer wall on the successful start-up from the frozen state. For successful start-up, the boundary specification at the outer wall surface must melt the working substance in the condenser before dry-out takes place in the evaporator.

Jang, J.H.; Faghri, A. [Wright State Univ., Dayton, OH (United States); Chang, W.S.; Mahefkey, E.T. [Wright Research and Development Center, Wright-Patterson, OH (United States)

1989-08-01T23:59:59.000Z

268

Performance limits of gravity-assist heat pipes with simple wick structures  

SciTech Connect

Experiments using gravity-assist heat pipes with simple wick structures were used to establish performance limits due to entrainment of the liquid by the counterflowing vapor. A physical model is postulated which leads to a single correlation predicting entrainment limits for all data investigated. The characteristic length in the entrainment parameter is the depth of the wick structure and the model infers an upper bound on this parameter.

Prenger, F.C. Jr.; Kemme, J.E.

1981-01-01T23:59:59.000Z

269

Cost-effective solar collectors using heat pipes. Interim progress report No. 1, September 1977-March 1978  

DOE Green Energy (OSTI)

The objective is the demonstration of high performance, cost effective non-concentrating solar collectors using heat pipes. The end products will be directly applicable for efficient use with absorption and Rankine cycle chillers. Evacuated tubular solar collectors were selected as the only economical non-concentrating approach capable of efficient operation of chillers. The General Electric TC family of collectors was chosen because of their superior performance and compatibility with heat pipe integration. The system was designed and specified. This work included the integration of the heat pipe with the evacuated tubular solar collector and the pumped loop heat removal mechanism. To date, two heat pipe fluid-envelope combinations look attractive: water-aluminum bearing steel and ethanol-low carbon steel. The jury is still out on the ability for the water-aluminum bearing steel to survive freezing cycles and for ethanol-low carbon steel to withstand predicted 400/sup 0/C stagnation temperatures. Full scale cost analysis was not completed for either case. Two 4' x 4' panels, each with ten tubular collectors fitted with heat pipes, were erected at Thermacore to test various aspects of the heat pipe and its integration into the collector-pumped loop system.

Ernst, D.M.

1978-01-01T23:59:59.000Z

270

Sensitivity studies of heat transfer: forced convection across a cylindrical pipe and duct flow  

E-Print Network (OSTI)

We consider two common heat transfer processes and perform a through sensitivity study of the variables involved. We derive and discuss analytical formulas for the heat transfer coefficient in function of film velocity, air temperature and pipe diameter. The according plots relate to a qualitative analysis of the multi-variable function $h$, according to functional optimization. For each process, we provide with graphs and tables of the parameters of interest, such as the Reynolds number. This method of study and the specific values can constitute a useful reference for didactic purposes.

Ferrantelli, Andrea; Viljanen, Martti

2013-01-01T23:59:59.000Z

271

Performance of a cross-cooled desiccant dehumidifier prototype  

DOE Green Energy (OSTI)

The cross-cooled dehumidifier prototype was constructed in the form of a cube with a side dimension of 0.6 m. The cross-cooling was achieved by passing air through rectangular channels perpendicular to process channels which are lined with desiccant sheets consisting of 9..mu..m Syloid 63/sup TM/ silica gel held in a Teflon web. The process for the manufacture of the silica gel sheets was developed at the Illinois Institute of Technology. The dehumidifier prototype was installed in a test system that simulated the performance of a cross-cooled desiccant cooling system and monitored the performance of the prototype. The dehumidifier prototype was operated over a wide range of operating conditions which would be typically encountered in the field installation of such a system. Variables measured were the moisture cycled, cooling capacity, total cooling capacity and coefficient of performance.

Worek, W.M.; Lavan, Z.

1981-08-01T23:59:59.000Z

272

Preferential flow paths and heat pipes: Results from laboratory experiments on heat-driven flow in natural and artificial rock fractures  

SciTech Connect

Water flow in fractures under the conditions of partial saturation and thermal drive may lead to fast flow along preferential localized pathways and heat pipe conditions. Water flowing in fast pathways may ultimately contact waste packages at Yucca Mountain and transport radionuclides to the accessible environment. Sixteen experiments were conducted to visualize liquid flow in glass fracture models, a transparent epoxy fracture replica, and a rock/replica fracture assembly. Spatially resolved thermal monitoring was performed in seven of these experiments to evaluate heat-pipe formation. Depending on the fracture apertures and flow conditions, various flow regimes were observed including continuous rivulet flow for high flow rates, intermittent rivulet flow and drop flow for intermediate flow rates, and film flow for low flow rates and wide apertures. These flow regimes were present in both fracture models and in the replica of a natural fracture. Heat-pipe conditions indicated by low thermal gradients were observed in five experiments. Conditions conducive to heat-pipe formation include an evaporation zone, condensation zone, adequate space for vapor and liquid to travel, and appropriate fluid driving forces. In one of the two experiments where heat pipe conditions were not observed, adequate space for liquid-vapor counterflow was not provided. Heat pipe conditions were not established in the other, because liquid flow was inadequate to compensate for imbibition and the quantity of heat contained within the rock.

Kneafsey, T.J.; Pruess, K. [Lawrence Berkeley National Lab., CA (United States). Earth Sciences Div.

1997-06-01T23:59:59.000Z

273

Laboratory Test Report for Six ENERGY STAR Dehumidifiers  

Science Conference Proceedings (OSTI)

This report documents the measured performance of six residential ENERGY STAR vapor compression dehumidifiers. The performance of each was measured over a wide range of inlet air conditions and fit to a numerical model for capacity and efficiency. Performance curves were developed for use in EnergyPlus. Test data from all six dehumidifiers were also fit to generic performance curves. This work can be used by energy modelers and equipment manufacturers to understand how current products will operate in a wide range of environments, and to develop advanced space conditioning systems for efficient, safe, durable and healthy homes.

Winkler, J.; Christensen, D.; Tomerlin, J.

2011-12-01T23:59:59.000Z

274

Statistical analysis of a silica gel rotary dehumidifier  

SciTech Connect

A regression analysis was conducted on experimental data obtained during the testing of a solid desiccant dehumidifier at the Solar Energy Research Institute (SERI has since been renamed the National Renewable Energy Laboratory). The data obtained was studied using statistical techniques to determine the regression equation for the temperature and humidity at the processed air outlet of the dehumidifier. These variables determine the cooling capacity and efficiency (Coefficient of Performance) of any desiccant cooling cycle. The analysis is used to determine the relative impact the input parameters have on the outlet temperature and humidity.

Kini, A.; Waugaman, D.G.; Kettleborough, C.F. (Texas A and M Univ., College Station (United States))

1993-01-01T23:59:59.000Z

275

Integrated heat pipe-thermal storage design for a solar receiver. [Constant power source with heat from sun or from storage  

SciTech Connect

Light-weight heat pipe wall elements that incorporate a thermal storage subassembly within the vapor space are being developed as part of the Organic Rankine Cycle Solar Dynamic Power Systems (ORC-SDPS) receiver for the space station application. The operating temperature of he heat pipe elements is in the 770 to 810/sup 0/K range with a design power throughput of 4.8 kW per pipe. The total heat pipe length is 1.9 M. The Rankine cycle boiler heat transfer surfaces are positioned within the heat pipe vapor space, providing a relatively constant temperature input to the vaporizer. The heat pipe design employs axial arteries and distribution wicked thermal storage units with potassium as the working fluid. Stainless steel is used as the containment tube and screen material. Performance predictions for this configuration have been conducted and the design characterized as a function of artery geometry, distribution wick thickness, porosity, pore size, and permeability. Details of the analysis and of fabrication and assembly procedures are presented. 2 refs., 8 figs.

Keddy, E.S.; Sena, J.T.; Woloshun, K.; Merrigan, M.A.; Heidenreich, G.

1986-01-01T23:59:59.000Z

276

An underground nuclear power station using self-regulating heat-pipe controlled reactors  

DOE Patents (OSTI)

A nuclear reactor for generating electricity is disposed underground at the bottom of a vertical hole that can be drilled using conventional drilling technology. The primary coolant of the reactor core is the working fluid in a plurality of thermodynamically coupled heat pipes emplaced in the hole between the heat source at the bottom of the hole and heat exchange means near the surface of the earth. Additionally, the primary coolant (consisting of the working fluid in the heat pipes in the reactor core) moderates neutrons and regulates their reactivity, thus keeping the power of the reactor substantially constant. At the end of its useful life, the reactor core may be abandoned in place. Isolation from the atmosphere in case of accident or for abandonment is provided by the operation of explosive closures and mechanical valves emplaced along the hole. This invention combines technology developed and tested for small, highly efficient, space-based nuclear electric power plants with the technology of fast- acting closure mechanisms developed and used for underground testing of nuclear weapons. This invention provides a nuclear power installation which is safe from the worst conceivable reactor accident, namely, the explosion of a nuclear weapon near the ground surface of a nuclear power reactor. 5 figs.

Hampel, V.E.

1988-05-17T23:59:59.000Z

277

Underground nuclear power station using self-regulating heat-pipe controlled reactors  

DOE Patents (OSTI)

A nuclear reactor for generating electricity is disposed underground at the bottom of a vertical hole that can be drilled using conventional drilling technology. The primary coolant of the reactor core is the working fluid in a plurality of thermodynamically coupled heat pipes emplaced in the hole between the heat source at the bottom of the hole and heat exchange means near the surface of the earth. Additionally, the primary coolant (consisting of the working flud in the heat pipes in the reactor core) moderates neutrons and regulates their reactivity, thus keeping the power of the reactor substantially constant. At the end of its useful life, the reactor core may be abandoned in place. Isolation from the atmosphere in case of accident or for abandonment is provided by the operation of explosive closures and mechanical valves emplaced along the hole. This invention combines technology developed and tested for small, highly efficient, space-based nuclear electric power plants with the technology of fast-acting closure mechanisms developed and used for underground testing of nuclear weapons. This invention provides a nuclear power installation which is safe from the worst conceivable reactor accident, namely, the explosion of a nuclear weapon near the ground surface of a nuclear power reactor.

Hampel, Viktor E. (Pleasanton, CA)

1989-01-01T23:59:59.000Z

278

Heat-pipe gas-combustion system endurance test for Stirling engine. Final report, May 1990-September 1990  

SciTech Connect

Stirling Thermal Motors, Inc., (STM) has been developing a general purpose Heat Pipe Gas Combustion System (HPGC) suitable for use with the STM4-120 Stirling engine. The HPGC consists of a parallel plate recuperative preheater, a finned heat pipe evaporator and a film cooled gas combustor. A principal component of the HPGC is the heat pipe evaporator which collects and distributes the liquid sodium over the heat transfer surfaces. The liquid sodium evaporates and flows to the condensers where it delivers its latent heat. The report presents test results of endurance tests run on a Gas-Fired Stirling Engine (GFSE). Tests on a dynamometer test stand yielded 67 hours of engine operation at power levels over 10 kW (13.5 hp) with 26 hours at power levels above 15 kW (20 hp). Total testing of the engine, including both motoring tests and engine operation, yielded 245 hours of engine run time.

Mahrle, P.

1990-12-01T23:59:59.000Z

279

Analysis of a flexible polymeric film with imbedded micro heat pipes for spacecraft radiators  

E-Print Network (OSTI)

In response to the pursuit of interplanetary travel and a continuous human presence in space, there is increasing focus within the space industry on spacecraft designs that change configuration within the space environment. Flexible thermal radiators are being developed to accommodate deployment mechanisms. An analytical model suggests that a lightweight polymeric material with imbedded micro heat pipe arrays can meet heat dissipation requirements while contributing less mass than competing flexible materials. The heat pipe capillary limit is evaluated as a function of temperature using two candidate working fluids. Using water, maximum heat transport is 18 mW per channel at 140° to 160° C. Maximum heat transport using methanol is 2.2 mW at 120° C: an order-of-magnitude difference. A thermal circuit model translates heat transport per channel into total radiator capacity as a function of heat source temperature and environmental sink temperature. Using water as the working fluid, radiator capacity varies from 6.0 kW to 12.2 kW for source temperatures from 20° to 50° C. For source temperatures 40° C and higher, capacity meets or exceeds the dissipation requirements of a reference spacecraft design. Methanol is not recommended as a working fluid because it produces radiator capacities two to three times lower than when water is used. Although thermal control system specifications constrain the micro heat pipe operating range, design changes directed at alleviating capillary limitations should increase radiator capacity. Technical issues for further investigation include effects of film billowing; performance limitations related to vapor viscosity; working fluid diffusion; and chemical reactivity between the case and working fluid. Compared to a competing graphite fiber weave, the polymeric material has an effective conductivity over ten times higher. Its area power density (kW/m²) is 18% to 60% lower than the graphite weave, but its mass power density (kW/kg) is several times higher. Greater flexibility and lower mass make it more amenable to structural integration than the graphite material. Recently developed space-stable polymers offer resistance to harsh temperature and radiation environments, helping to clear the path toward a more extensive use of polymers within the space industry.

McDaniels, Deborah Marie

2001-01-01T23:59:59.000Z

280

Analysis of a Fabric/Desiccant Window Cavity Dehumidifier  

E-Print Network (OSTI)

This paper presents the results of an exploratory study of a fabric/desiccant window cavity dehumidifier system for possible use in commercial buildings. The objective was to evaluate fabrics commonly used in buildings, and system concepts that employ these fabrics, which can be used to dehumidify room air. We developed a first-order energy/mass balance model to determine the performance of a window cavity dehumidifier that uses silica gel encapsulated in a fabric matrix rotating on a belt alternately through dehumidification and regeneration chambers; the modeling effort was supplemented by environmental chamber measurements of the moisture absorption characteristics of 16 fabric/desiccant combinations. We ran the model for a typical office building module, for outside air design conditions characteristic of the most difficult humidity regime in Texas. Two flow configurations, outside air and return air, were evaluated to determine the capability of such a system to dehumidify the air streams under consideration. Issues addressed included the physical limitations on the amount of desiccant that can be included in this configuration and the degree of dehumidification achievable.

Hunn, B. D.; Grasso, M. M.; Vadlamani, V.

1994-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Development of an Energy Efficient Desiccant Dehumidifier : Final Report.  

SciTech Connect

Humidity control in space conditioning has received a good deal of attention in the past twenty or so years. Perhaps the most familiar application is the use of humidifiers in the winter months. Of equal concern is the use of air conditions and dehumidifiers in the summer months. High humidity levels in summer months require lower coil temperatures in order to achieve human comfort levels, and may result in significant product and property damage if humidity levels are not controlled at appropriate level. This study addresses the solid desiccant dehumidifier using IR heaters as an energy efficient desiccant dehumidifier (EEDD). The study is divided into two phases; Phase 1 -- Application assessment; and Phase 2: Prototype design, manufacture, and testing. Phase 1 addresses the total electrical energy usage by all possible applications of the EEDD and evaluates the energy performance of the EEDD in terms of its percentage energy savings compared to the conventional vapor compression cooling and also with the state-of-the-art desiccant dehumidifiers. During Phase 2, a functional EEDD prototype unit was designed and manufactured. The work of Phase 2 was divided into four tasks: Task 1, conceptual design; Task 2, mechanical (blueprint) design; Task 3, manufacture and factory testing; and Task 4, performance testing. 17 refs., 21 figs., 30 tabs.

Relwani, Suresh M.; Moschandreas, Demetrios J.

1990-04-01T23:59:59.000Z

282

Facility design for cyclic testing of advanced solid desiccant dehumidifiers  

DOE Green Energy (OSTI)

The development of high performance components is required to reach the goal of desiccant cooling system cost-competitiveness with conventional vapor compensation air conditioning systems. SERI has designed a laminar flow, parallel passage dehumidifier that has this potential. The goal of SERI's desiccant cooling research program is to fully characterize experimentally the performance of the parallel passage dehumidifier under a wide range of operating conditions, investigate improvements in design, and verify existing models of dehumidifier performance against experimental results. This report documents the design of the SERI Desiccant Cooling Test Facility for performing the above testing. With slight modifications, the testing can be used for testing other desiccant cooling system components. The dehumidifier processes and the parameters and variables needed to control and characterize its performance are presented. The physical layout of the test loop and instrumentation for monitoring the operating conditions and dehumidifer performance and the controls for maintaining the operating conditions are specified. The computerized data acquisition system conversion equations and an error analysis of measurement variables are also presented.

Schlepp, D.; Schultz, K.; Zangrando, F.

1984-08-01T23:59:59.000Z

283

Shutdown Protection of Steam Turbines Using Dehumidified Air  

Science Conference Proceedings (OSTI)

EPRI research has determined that proper protection of the steam turbine during shutdown periods is essential to the prevention of damage by stress corrosion cracking and corrosion fatigue. This report provides information on both the incipient damage of improper shutdown and techniques for assessing and applying dehumidified air for shutdown protection.

2008-03-26T23:59:59.000Z

284

Analysis of Selection of Single or Double U-bend Pipes in a Ground Source Heat Pump System  

E-Print Network (OSTI)

The ground source heat pump (GSHP) system is widely used because of its energy-saving and environmental-friendly characteristics. The buried pipes heat exchangers play an important role in the whole GSHP system design. However, in most cases, single U-bend pipes are adopted only for their simplicity in design and construction instead of high efficiency and less operation cost of the whole system. In this paper, we make a comparison between single and double U-bend pipe heat exchangers in their heat exchange rate per depth, the number of boreholes needed for the same amount of cooling load, total lengths of pipes for the two different types of heat exchangers, and seasonal overall energy efficiency of the two GSHP systems. An economic analysis method is also presented. Finally, conclusions are made for the selection of single or double U-bend pipe heat exchangers in a GSHP system after a case study using TRNSYS simulation software is carried out.

Shu, H.; Duanmu, L.; Hua, R.

2006-01-01T23:59:59.000Z

285

Page 5-22- Water Heating Requirements – Glossary/Reference Figure 5-2 – Point of Use Distribution System Pipe Insulation  

E-Print Network (OSTI)

Credit is available for insulation of hot water pipes in addition to insulation required by the mandatory requirements. For systems serving a single dwelling unit, this credit applies only to non-circulating systems. For systems serving multiple dwelling units, there is a pipe insulation credit for recirculating piping external to dwelling units if pipes are insulated to a higher R-value than the mandatory minimum. Installation Criteria (Single Dwelling Unit): Insulation must meet the level required in the mandatory requirements. Note that pipes buried under ceiling insulation can meet the mandatory requirements. Note: Heat tape – electric resistance heating tape wrapped around hot water pipes – may be used only for freeze protection and cannot be used instead of mandatory pipe insulation (see Section §150(j)) or pipe insulation receiving

unknown authors

2005-01-01T23:59:59.000Z

286

Dehumidification Performance of Air Conditioning Systems in Supermarkets: Field Demonstration with Heat Pipe Heat Exchangers in Delchamps Supermarket, Gulf Breeze, Florida  

Science Conference Proceedings (OSTI)

Lower humidity in supermarkets translates to reduced operational cost from refrigeration equipment. A demonstration project at a Florida supermarket showed that use of a heat pipe heat exchanger (HPHX) improved the HVAC system's dehumidification performance; but lower airflow rates, with or without an HPHX, also provided significant dehumidification enhancements.

1996-07-27T23:59:59.000Z

287

Evacuated tubular collector utilizing a heat pipe. Progress report, May 1 1975--August 31, 1975  

DOE Green Energy (OSTI)

Research and development activities performed by the Corning Glass Works solar group during the period from May 1, 1975 to August 31, 1975 are reported. The analytical studies encompassed optical modeling of a modified cusp reflector, fresnel losses from tubular enclosures as a function of orientation, preliminary work on a digital Monte-Carlo Ray Tracing Computer Code and the determination of U/sub L/ losses as a function of vacuum level and temperature of the absorber. Compatible enclosure materials, wicks and working fluids were selected to assemble heat pipes for use as solar collector absorbers. Cusp reflectors with good accuracy were fabricated from various commercial bright aluminum sheet and their optical properties determined. Evacuation techniques were developed and special bake-out procedures were worked out to assemble the evacuated tubular collectors. The work on selective coatings narrowed down the field of potential absorber films to ''black chrome'' which has good stability in vacuum and the necessary ..cap alpha../epsilon value. Six different heat pipes and one flow-through absorber were fabricated and were partially characterized for thermal performance. Indoor and outdoor test facilities were completed and calibrated within proposed NBS standards. They are now available for parametric as well as true-life experiments with solar radiation.

Ortabasi, U.; Fehlner, F.P.

1975-01-01T23:59:59.000Z

288

An examination of metal felt wicks for heat-pipe applications  

DOE Green Energy (OSTI)

Precision metal felts are made of filaments of microndiameter wires that are chopped and layered onto a flat surface to form a wool-like material. Metal felts are commonly used as filters for micron-sized particles. The small diameters of the wires and the relatively open structure of these non-woven materials provide porosities on the order of 90% and greater. The high porosities of metal felts make them interesting candidate materials for heat pipe applications. Property measurements on selected samples of metal felts have demonstrated that typical effective pore radii range from 40 to 120 {mu}m and the respective Darcy permeabilities range from 30 to 300 {mu}m{sup 2}. Through careful compaction of these materials, it is possible to tailor the flow characteristics of the materials to specific applications. Recently, a series of tests have been conducted at Sandia to measure the flow characteristics and pore structures of these materials as a function of compaction. Results from these tests and a discussion of the current applications of these materials in liquid-metal heat pipes for solar power conversion systems are presented in this paper.

Adkins, D.R.; Moss, T.A.; Andraka, C.E. [Sandia National Labs., Albuquerque, NM (United States); Andreas, N.H. [Bekaert Fibre Technologies, Marietta, GA (United States); Cole, H.M. [Porous Metal Products, Jacksboro, TX (United States)

1994-11-01T23:59:59.000Z

289

Evacuated-Tube Heat-Pipe Solar Collectors Applied to the Recirculation Loop in a Federal Building: Preprint  

DOE Green Energy (OSTI)

This paper describes the design, simulation, construction, and initial performance of a solar water heating system (a 360-tube evacuated-tube heat-pipe solar collector, 54 m2 in gross area, 36 m2 in net absorber area) installed at the top of the hot water recirculation loop in the Social Security Administration's Mid-Atlantic Center in Philadelphia. When solar energy is available, water returning to the hot water storage tank is heated by the solar array. This new approach, in contrast to the more conventional approach of preheating incoming water, is made possible by the thermal diode effect of heat pipes and low heat loss from evacuated-tube solar collectors. The simplicity of this approach and its low installation costs support the deployment of solar energy in existing commercial buildings, especially where the roof is some distance away from the water heating system, which is often in the basement. Initial performance measurements of the system are reported.

Walker, A.; Mahjouri, F.; Stiteler, R.

2004-06-01T23:59:59.000Z

290

Investigation of a novel façade-based solar loop heat pipe water heating system.  

E-Print Network (OSTI)

??Solar thermal is one of the most cost-effective renewable energy technologies, and solar water heating is one of the most popular solar thermal systems. Based… (more)

Wang, Zhangyuan

2012-01-01T23:59:59.000Z

291

Thermal Performance Predictions of a Heat Pipe and Heat Dissipation Systems Using FEM.  

E-Print Network (OSTI)

??The aim of this work is to carry out analyses, thermal and fluid dynamics of element used to heat transimission that can be utilized to… (more)

VIGNA, GIUSEPPE

2008-01-01T23:59:59.000Z

292

Influence of Transfer Efficiency of the Outdoor Pipe Network and Boiler Operating Efficiency on the Building Heat Consumption Index  

E-Print Network (OSTI)

This paper analyzes the influence of transfer efficiency of the outdoor pipe network and operating efficiency of the boiler on the building heat consumption index, on the premise of saving up to 65 percent energy in different climates. The results show that transfer efficiency is not influenced by the climate, and the influence is in accordance with that in other climates. The article also presents data on the energy consumption caused by the improvement of the transfer efficiency of the outdoor pipe network and the operating efficiency of the boiler, and the calculated formula for the building heat consumption index on the condition of saving 65 percent energy.

Fang, X.; Wang, Z.; Liu, H.

2006-01-01T23:59:59.000Z

293

Pipe connector  

DOE Patents (OSTI)

A safety test facility for testing sodium-cooled nuclear reactor components includes a reactor vessel and a heat exchanger submerged in sodium in the tank. The reactor vessel and heat exchanger are connected by an expansion/deflection pipe coupling comprising a pair of coaxially and slidably engaged tubular elements having radially enlarged opposed end portions of which at least a part is of spherical contour adapted to engage conical sockets in the ends of pipes leading out of the reactor vessel and in to the heat exchanger. A spring surrounding the pipe coupling urges the end portions apart and into engagement with the spherical sockets. Since the pipe coupling is submerged in liquid a limited amount of leakage of sodium from the pipe can be tolerated.

Sullivan, Thomas E. (Evergreen Park, IL); Pardini, John A. (Brookfield, IL)

1978-01-01T23:59:59.000Z

294

Laboratory Test Report for Six ENERGY STAR Dehumidifiers  

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

Test Report for Six Test Report for Six ENERGY STAR ® Dehumidifiers Jon Winkler, Ph.D., Dane Christensen, Ph.D., and Jeff Tomerlin Technical Report NREL/TP-5500-52791 December 2011 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. National Renewable Energy Laboratory 1617 Cole Boulevard Golden, Colorado 80401 303-275-3000 * www.nrel.gov Contract No. DE-AC36-08GO28308 Laboratory Test Report for Six ENERGY STAR ® Dehumidifiers Jon Winkler, Ph.D., Dane Christensen, Ph.D., and Jeff Tomerlin Prepared under Task No. BE11.0201 Technical Report NREL/TP-5500-52791 December 2011 NOTICE This report was prepared as an account of work sponsored by an agency of the United States government.

295

ON THE TRANSFER OF HEAT TO FLUIDS FLOWING THROUGH PIPES, ANNULI, AND PARALLEL PLATES  

SciTech Connect

Nusselt numbers were calculated for heat transfer to fluids flowing through annuli under conditions of uniform heat flux and fully established velocity and temperature profiles. The following cases were considered: (a) laminar flow, (b) slug flow, (c) turbulent flow with molecular conduction only, and (d) turbulent flow with both molecular and eddy conduction. These Nusselt numbers were determined for two conditions: heat transfer from the inner wall only and heat transfer from the outer wall only. The results were correlated by semi-empirical equations. The final results obtained on cases (a), (b), amd (c) are applicable to any fluid, whereas those obtained on (d) are for liquid metals only. Wall- and bulk-temperature relationships for the above four cases were also determined. These relationships were treated as dimensionless temperature ratios. Both the Nusselt numbers ad temperature ratios were evaluated over the r/ sub 1//r/sub 2/ range, zero to unity; the former being the case of the circular pipe, and the later, the case of infinite parallel plates. (auth)

Dwyer, O.E.

1963-01-01T23:59:59.000Z

296

Closed loop chemical systems for energy storage and transmission (chemical heat pipe). Final report  

DOE Green Energy (OSTI)

The work documents the anlaysis of closed loop chemical systems for energy storage and transmission, commonly referred to as the Chemical Heat Pipe (CHP). Among the various chemical reaction systems and sources investigated, the two best systems were determined to be the high temperature methane/steam reforming reaction (HTCHP) coupled to a Very High Temperature Gas Cooled Reactor (VHTR) and the lower temperature, cyclohexane dehydrogenation reaction (LTCHP) coupled to existing sources such as coal or light water reactors. Solar and other developing technologies can best be coupled to the LTCHP. The preliminary economic and technical analyses show that both systems could transport heat at an incremental cost of approximately $1.50/GJ/160 km (in excess of the primary heat cost of $2.50/GJ), at system efficiencies above 80%. Solar heat can be transported at an incremental cost of $3/GJ/160 km. The use of the mixed feed evaporator concept developed in this work contributes significantly to reducing the transportation cost and increasing the efficiency of the system. The LTCHP shows the most promise of the two systems if the technical feasibility of the cyclic closed loop chemical reaction system can be established. An experimental program for establishing this feasibility is recommended. Since the VHTR is several years away from commercial demonstration and the HTCHP chemical technology is well developed, future HTCHP programs should be aimed at VHTR and interface problems.

Vakil, H.B.; Flock, J.W.

1978-02-01T23:59:59.000Z

297

Heat Transfer Performance and Piping Strategy Study for Chilled Water Systems at Low Cooling Loads  

E-Print Network (OSTI)

The temperature differential of chilled water is an important factor used for evaluating the performance of a chilled water system. A low delta-T may increase the pumping energy consumption and increase the chiller energy consumption. The system studied in this thesis is the chilled water system at the Dallas/Fort Worth International Airport (DFW Airport). This system has the problem of low delta-T under low cooling loads. When the chilled water flow is much lower than the design conditions at low cooling loads, it may lead to the laminar flow of the chilled water in the cooling coils. The main objective of this thesis is to explain the heat transfer performance of the cooling coils under low cooling loads. The water side and air side heat transfer coefficients at different water and air flow rates are calculated. The coefficients are used to analyze the heat transfer performance of the cooling coils at conditions ranging from very low loads to design conditions. The effectiveness-number of transfer units (NTU) method is utilized to analyze the cooling coil performance under different flow conditions, which also helps to obtain the cooling coil chilled water temperature differential under full load and partial load conditions. When the water flow rate drops to 1ft/s, laminar flow occurs; this further decreases the heat transfer rate on the water side. However, the cooling coil effectiveness increases with the drop of water flow rate, which compensates for the influence of the heat transfer performance under laminar flow conditions. Consequently, the delta-T in the cooling coil decreases in the transitional flow regime but increases in the laminar flow regime. Results of this thesis show that the laminar flow for the chilled water at low flow rate is not the main cause of the low delta-T syndrome in the chilled water system. Possible causes for the piping strategy of the low delta-T syndrome existing in the chilled water system under low flow conditions are studied in this thesis: (1) use of two way control valves; and (2) improper tertiary pump piping strategy.

Li, Nanxi 1986-

2012-12-01T23:59:59.000Z

298

Balance-of-plant options for the Heat-Pipe Power System  

DOE Green Energy (OSTI)

The Heat-Pipe Power System (HPS) is a near-term, low-cost space fission power system with the potential for utilizing various option for balance-of-plant options. The following options have been studied: a low-power thermoelectric design (14-kWe output), a small Brayton cycle system (60--75 kWe), and a large Brayton cycle system (250 kWe). These systems were analyzed on a preliminary basis, including mass, volume, and structure calculations. These analyses have shown that the HPS system can provide power outputs from 10--250 kWe with specific powers of {approximately} 14 W/kg for a 14-kWe model to {approximately} 100 W/kg for a 250-kWe model. The system designs considered in this study utilize a common component base to permit easy expansion and development.

Berte, M. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Nuclear Engineering Dept.; Capell, B. [Michigan Univ., Ann Arbor, MI (United States). Nuclear Engineering Dept.

1997-09-01T23:59:59.000Z

299

Experimental Determination of the Effect of Last Pass Heat Sink Welding on Residual Stress in a Large Stainless Steel Pipe  

Science Conference Proceedings (OSTI)

This report discusses the experimental determination of through-wall residual distribution at welds in a 24-inch diameter heavy wall pipe. The results of a conventional butt weld and a butt weld made using the last pass heat sink welding method are compared.

1983-11-01T23:59:59.000Z

300

A Hot Plate Solar Cooker with Electricity Generation - Combining a Parabolic Trough Mirror with a Sidney Tube and Heat Pipe  

Science Conference Proceedings (OSTI)

Solar cookers supply clean and sustainable energy for cooking and so limit the use of wood or charcoal. A new type of solar cooker is developed with a hot plate. The hot plate offers comfortable access to the food under preparation. The hot plate opens ... Keywords: Sidney Tube, TEG, heat pipe, hot plate, solar cooker

A. D. J. Kaasjager; G. P. G. Moeys

2012-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Cryogenic Loop Heat Pipes for the Cooling of Small Particle Detectors at CERN  

E-Print Network (OSTI)

The loop heat pipe (LHP) is among the most effective heat transfer elements. Its principle is based on a continuous evaporation/condensation process and its passive nature does not require any mechanical devices such as pumps to circulate the cooling agent. Instead a porous wick structure in the evaporator provides the capillary pumping forces to drive the fluid [1]. Cryogenic LHP are investigated as potential candidates for the cooling of future small-scale particle detectors and upgrades of existing ones. A large spectrum of cryogenic temperatures can be covered by choosing appropriate working fluids. For high luminosity upgrades of existing experiments installed at the Large Hadron Collider (LHC) (TOTEM) and planned ones (FP420) [2-3] being in the design phase, radiation-hard solutions are studied with noble gases as working fluids to limit the radiolysis effect on molecules detrimental to the functioning of the LHP. The installation compactness requirement of experiments such as the CAST frame-store CCD d...

Pereira, H; Silva, P; Wu, J; Koettig, T; 10.1063/1.3422264

2010-01-01T23:59:59.000Z

302

Development of a solar desiccant dehumidifier. Second technical progress report  

SciTech Connect

Research and development of a solar desiccant dehumidifier featuring a rotary bed of granular silica gel and a rotary regenerator for air conditioning is described. The results of the system optimization studies are presented. The studies involved an extensive investigation of the energy saving potential and economic viability of the solar desiccant dehumidifier in different locations in the United States. Conventional electric vapor compression, and solar absorption and Rankine systems also were investigated for comparison. In general, it was found that the solar desiccant equipment, either by itself or in a hybrid system with an electric vapor compression air conditioner, is economically viable for all three locations considered. Substantial energy savings can be effected as well. Seal tests done at AiResearch to develop practical dynamic air seals are described. Leakage and friction tests were performed on a variety of material combinations and configurations. Dacron felt and silicone rubber were found to give an acceptable combination of leakage, friction, and cost characteristics. As part of the commercialization studies for the desiccant equipment, a questionnaire was sent to residential air conditioning equipment distributors. The results of the questionnaire are presented. The specifications and drawings for the 1.5-ton prototype are included. (WHK)

Gunderson, M.E.; Hwang, K.C.; Railing, S.M.; Rousseau, J.

1978-11-10T23:59:59.000Z

303

PC-based fluid and heat transfer analyzer for two-phase flow in pipes.  

E-Print Network (OSTI)

??Modeling the simultaneous flow of gas and liquid or two-phase gas-liquid flow in pipes is a key aspect in petroleum production. These models can enhance… (more)

Afonja, Gbolahan.

2006-01-01T23:59:59.000Z

304

Analysis of a Flat-Plate, Liquid-Desiccant, Dehumidifier and Regenerator.  

E-Print Network (OSTI)

??A numerical model for isothermal and non-isothermal flat-plate liquid-desiccant dehumidifiers and regenerators was developed and implemented. The two-dimensional model takes into account the desiccant, water… (more)

Mesquita, Lucio Cesar De Souza

2008-01-01T23:59:59.000Z

305

Solar dynamic heat pipe development and endurance test. Monthly technical progress report number 4, August 28--September 29, 1987  

SciTech Connect

The Space Station requires a high level of reliable electric power. The baseline approach is to utilize a hybrid system in which power is provided by photovoltaic arrays and by solar dynamic power conversion modules. The organic Rankine cycle (ORC) engine is one approach to solar dynamic conversion. The ORC provides the attributes of high efficiency at low temperature and compact simple designs utilizing conventional techniques and materials. The heat receiver is one area which must be addressed in applying the proven ORC to long life applications such as the Space Station. Heat pipes with integral thermal energy storage (TES) canisters and a toluene heater tube are the prime components of the heat receiver from the Phase B preliminary design. This contract is a task order type addressing the design, fabrication and testing of a full scale heat pipe. The contract was initiated on April 16, 1987. Sundstrand has specific responsibilities in each task. Los Alamos National Laboratory (LANL) in turn has the prime contract responsibility to NASA-LeRC.

Parekh, M.B. [Sundstrand Energy Systems, Rockford, IL (United States)

1987-09-29T23:59:59.000Z

306

Heat Pipe Performance Enhancement with Binary Mixture Fluids that Exhibit Strong Concentration Marangoni Effects  

E-Print Network (OSTI)

Q ? Al in the heat transfer process and the relation betweenv and Q ? Br in the heat transfer process, and the relationan internal cavity. This heat transfer process for the heat

Armijo, Kenneth Miguel

2011-01-01T23:59:59.000Z

307

A Temperature-Profile Method for Estimating Flow Processes in Geologic Heat Pipes  

E-Print Network (OSTI)

make sure that the heat transfer processes are approximatelyfocus is on the heat and mass transfer processes within the

Birkholzer, Jens T.

2004-01-01T23:59:59.000Z

308

CFD MODELING OF ITER CABLE-IN-CONDUIT SUPERCONDUCTORS. PART V: COMBINED MOMENTUM AND HEAT TRANSFER IN RIB ROUGHENED PIPES  

Science Conference Proceedings (OSTI)

Computational Fluid Dynamics (CFD) techniques have been proposed and applied in a series of papers to analyze cable-in-conduit conductors (CICC) for the International Thermonuclear Experimental Reactor (ITER). Previous work on the pressure drop in the central channel of ITER CICC is extended here to the problem of combined heat and momentum transfer. The CFD model, solved by the FLUENT commercial code, is first validated against 2D and 3D data from compact heat exchangers, showing good agreement. The Colburn analogy between the friction factor f and the Nusselt number Nu is not verified in the considered 2D geometries, as shown by both experiment and simulation. The validated CFD model is finally applied to the 3D analysis of central channel-like geometries relevant for ITER CICC. It is shown that the heat transfer coefficient on the central channel side stays relatively close to the smooth-pipe (Dittus-Boelter) value.

Zanino, R.; Giors, S. [Dipartimento di Energetica, Politecnico Torino, I-10129 (Italy)

2008-03-16T23:59:59.000Z

309

NREL Tests Dehumidifiers, Defines Simplified Simulation Model (Fact Sheet), NREL Highlights, Research & Development, NREL (National Renewable Energy Laboratory)  

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

residential dehumidifiers residential dehumidifiers results in practical performance curves for use in whole-building simulation tools. Dehumidifiers remove moisture from a home's indoor environment, thereby increasing occupant comfort, improving air quality, and reducing the likelihood of mold, rot, and dust mites. To help energy professionals more easily evaluate this technology for the market, National Renewable Energy Laboratory (NREL) researchers tested the efficiency and capacity of a variety of dehumidifiers and developed a generalized approach to simulate any residential dehumidifier. The test results and modeling method are documented in a new report. Typically, dehumidifiers are only rated at a single temperature and humidity, so rating data alone cannot determine whether a product will meet the moisture removal

310

Assessing Consumer Values and the Supply-Chain Market for the Integrated Water Heater/Dehumidifier  

SciTech Connect

This paper presents a case study of the potential market for the dual-service residential integrated water heater/dehumidifier (WHD). Its principal purpose is to evaluate the extent to which this integrated appliance might penetrate the residential market sector, given current market trends, producer and consumer attributes, and technical parameters. The report's secondary purpose is to gather background information leading to a generic framework for conducting market analyses of technologies. This framework can be used to assess market readiness as well as factor preferred product attributes into the design to drive consumer demand for this product. This study also supports analysis for prototype design. A full market analysis for potential commercialization should be conducted after prototype development. The integrated WHD is essentially a heat-pump water heater (HPWH) with components and controls that allow dedicated dehumidification. Adequate residential humidity control is a growing issue for newly constructed residential homes, which are insulated so well that mechanical ventilation may be necessary to meet fresh air requirements. Leveraging its successful experience with the energy-efficient design improvement for the residential HPWH, the Oak Ridge National Laboratory's (ORNL's) Engineering Science and Technology Division's (ESTD's) Building Equipment Group designed a water-heating appliance that combines HPWH efficiency with dedicated dehumidification. This integrated appliance could be a low-cost solution for dehumidification and efficient electric water heating. ORNL is partnering with Western Carolina University, Asheville-Buncombe Technical Community College, American Carolina Stamping Company, and Clemson University to develop this appliance and assess its market potential. For practical purposes, consumers are indifferent to how water is heated but are very interested in product attributes such as initial first cost, operating cost, performance, serviceability, product size, and installation costs. The principal drivers for penetrating markets are demonstrating reliability, leveraging the dehumidification attributes of the integrated WHD, and creating programs that embrace first-cost and life-cycle cost principles.

Ashdown, BG

2005-01-11T23:59:59.000Z

311

Heat Pipe Performance Enhancement with Binary Mixture Fluids that Exhibit Strong Concentration Marangoni Effects  

E-Print Network (OSTI)

§2.2.3 – Heat Capacity………..…………………………………………………. ii §Eq. (2.1). 2.2.3 Heat Capacity The pure liquid predictionsfrom definition of heat capacity in terms of the Prandtl

Armijo, Kenneth Miguel

2011-01-01T23:59:59.000Z

312

Proof of Operation in a Planar Loop Heat Pipe (LHP) Based on CPS Wick.  

E-Print Network (OSTI)

??As electronic design allows higher throughput in small packages, dissipating the heat load becomes a critical design factor. Available cooling approaches, such as extruded heat… (more)

Suh, Junwoo

2005-01-01T23:59:59.000Z

313

A WSRC-MS-g8-00318 Heat Transfer Model of Above and Underground Insulated Piping  

Office of Scientific and Technical Information (OSTI)

WSRC-MS-g8-00318 Heat Transfer Model of Above and Underground Insulated Piping Systems by K. C. Kwon Westinghouse Savannah River Company Savannah River Site Aiken, South Carolina 29808 A document prepared for ASME CONFERENCE - HEAT EXCHANGER COMMITTEE MEETING 8 , INTERNATIONAL JOINT POWER GENERATION CONFERENCE 1998 at Baltimore, MA, USA from 8/23/98 - 8/26/98. DOE Contract No. DE-AC09-96SR18500 This paper was prepared in connection with work done under the above contract number with the U. S. Department of Energy. By acceptance of this paper, the publisher and/or recipient acknowledges the U. S. Government's right to retain a nonexclusive, royalty-free license in and to any copyright covering this paper, along with the right to reproduce and to authorize others to reproduce all or part of the copyrighted paper.

314

Energy effectiveness of simultaneous heat and mass exchange devices  

E-Print Network (OSTI)

Simultaneous heat and mass exchange devices such as cooling towers, humidifiers and dehumidifiers are widely used in the power generation, desalination, air conditioning, and refrigeration industries. For design and rating ...

Narayan, G. Prakash

2010-01-01T23:59:59.000Z

315

Abstract A COUPLED CFD FINITE ELEMENT ANALYSIS METHODOLOGY IN A BIFURCATION PIPE IN A NUCLEAR PLANT HEAT EXCHANGER  

E-Print Network (OSTI)

The accurate calculation of temperature distribution in key parts of a nuclear plant plays a crucial role in maximising the power output and the plant efficiency, whilst ensuring safe operation. The need for making the most profitable use of the available sources of energy requires the full exploitation of plant operational capacity. Temperature dependent material properties mean that increasing the power output in a nuclear plant may reduce the life of the welds in the pipes of the heat exchanger (boiler), operating in very demanding conditions. Rolls-Royce plc was requested to come up with a suitable solution that shielded critical pipe weld locations, reducing local temperatures, so allowing a useful increase in power output from the plant. Part of the heat shield design process was a comprehensive thermal analysis of the installation. Traditionally fluid and solid simulations are conducted separately or using conjugate analysis. Standard methods rely on the application of boundary conditions to the wall surface, which are commonly based on empirical heat transfer coefficient correlations or approximate read across of the CFD results. An alternative approach using conjugate calculations can be adopted, but the computational cost and meshing difficulties in matching the fluid and solid grids makes this unaffordable in terms of analysis time. This paper presents the application of an improved method using a communication library (SC89) between the in-house finite element (FE) code SC03, and the commercial computational fluid dynamics (CFD) code FLUENT. The method has been validated using test data from a Perspex model, where heat transfer coefficients were measured using a transient liquid crystal technique.

J. A. Dixon; A. Guijarro Valencia; P. Irel; P. Ridl; N. Hills

2010-01-01T23:59:59.000Z

316

A multifunctional heat pipe sandwich panel structure Douglas T. Queheillalt a,*, Gerardo Carbajal b  

E-Print Network (OSTI)

...................................................77 3.4.1.7. Heat Transfer Due to the Heat Exchange Fluid ...............................79 3., Reykjavik, Iceland, was used to simulate the impact of ground-water flow on the average heat exchange fluid response of a fluid flowing through a ground heat exchanger in a single borehole. A schematic

Wadley, Haydn

317

Cross-cooled dehumidifier model test results and computer simulations  

DOE Green Energy (OSTI)

Research on the development of a solar operated cross-cooled desiccant cooling system is described. A 15 cm x 15 cm x 15 cm (6'' x 6'' x 6'') cross-cooled silica gel desiccant dehumidifier model was designed, built and tested. The process of producing the silica gel sheets, the design and construction of the unit, the test setup and the test procedures are described in detail. A total of twenty tests were performed to determine the effect of inlet process stream dew point, process stream and cooling stream flowrates and regeneration stream temperature and dew point, on the performance of the unit. The test results show that the unit performance improves with increasing regeneration temperature, process stream flowrate and process air inlet dew point. The unit performance decreases with increase of the regeneration stream dew point. The results clearly show that the process stream inlet dew point is the dominating factor and that the concept of cross-cooling works very well. With moderate cross-cooling, the unit performance can increase over 50%. All tests were simulated by a computer program. The experimental and theoretical results are in very good agreement.

Mei, V.; Lavan, Z.

1979-11-01T23:59:59.000Z

318

Testing of a solar powered cooling system using cross-cooled desiccant dehumidifiers  

DOE Green Energy (OSTI)

A solar powered desiccant cooling system using two fixed bed silica gel dehumidifiers has been designed, built and is being tested. The dehumidifiers, 0.6 x 0.6 x 0.6 m each, are constructed of 80 channels lined with 64 m/sup 2/ of 1.5 mm thick silica gel sheets. The bed is cooled by air flowing in an equal number of perpendicular channels. Both sets of channels are two mm wide, the dehumidifiers undergo adsorption, preheating, desorption and precooling in a cyclic fashion. The cooling capacity of the experimental system is one ton at ARI design conditions. The system has a high cooling capacity, high COP, low parasitic power consumption and requires low regeneration temperatures.

Monnier, J.B.; Worek, W.M.; Lavan, Z.

1981-01-01T23:59:59.000Z

319

THERMOSIPHON WATER HEATERS WITH HEAT EXCHANGERS  

E-Print Network (OSTI)

11 ector connecting pipes header heat exchanger insulationLt total connecting pipe length, m (ft) total number of heat

Mertol, Atila

2012-01-01T23:59:59.000Z

320

Improving Comfort in Hot-Humid Climates with a Whole-House Dehumidifier, Windermere, Florida (Fact Sheet)  

SciTech Connect

Maintaining comfort in a home can be challenging in hot-humid climates. At the common summer temperature set point of 75 degrees F, the perceived air temperature can vary by 11 degrees F because higher indoor humidity reduces comfort. Often the air conditioner (AC) thermostat set point is lower than the desirable cooling level to try to increase moisture removal so that the interior air is not humid or "muggy." However, this method is not always effective in maintaining indoor relative humidity (RH) or comfort. In order to quantify the performance of a combined whole-house dehumidifier (WHD) AC system, researchers from the U.S. Department of Energy's Building America team Consortium of Advanced Residential Buildings (CARB) monitored the operation of two Lennox AC systems coupled with a Honeywell DH150 TrueDRY whole-house dehumidifier for a six-month period. By using a WHD to control moisture levels (latent cooling) and optimizing a central AC to control temperature (sensible cooling), improvements in comfort can be achieved while reducing utility costs. Indoor comfort for this study was defined as maintaining indoor conditions at below 60% RH and a humidity ratio of 0.012 lbm/lbm while at common dry bulb set point temperatures of 74 degrees -80 degrees F. In addition to enhanced comfort, controlling moisture to these levels can reduce the risk of other potential issues such as mold growth, pests, and building component degradation. Because a standard AC must also reduce dry bulb air temperature in order to remove moisture, a WHD is typically needed to support these latent loads when sensible heat removal is not desired.

Not Available

2013-11-01T23:59:59.000Z

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


321

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

322

HEAT TRANSFER IN POROUS MEDIA WITH FLUID PHASE CHANGES  

E-Print Network (OSTI)

Cotter, T. P. : "Theory of Heat Pipe," Report No. LA-3246-L. : "Two Component Heat Pipes, It Propress in Astronauticsthe successful. The 'heat pipe ph periments were quite

Su, Ho-Jeen.

2010-01-01T23:59:59.000Z

323

Tubular and Sector Heat Pipes with Interconnected Branches for Gas Turbine and/or Compressor Cooling.  

E-Print Network (OSTI)

?? Designing turbines for either aerospace or power production is a daunting task for any heat transfer scientist or engineer. Turbine designers are continuously pursuing… (more)

Reding, Brian D., II

2013-01-01T23:59:59.000Z

324

Solar test of an integrated sodium reflux heat-pipe receiver/reactor for thermochemical energy transport  

DOE Green Energy (OSTI)

In October 1987, a chemical reactor integrated into a sodium reflux heat-pipe receiver was tested in the solar furnace at the Weizmann Institute of Science, Rehovot, Israel. The reaction carried out was the carbon dioxide reforming of methane. This reaction is one of the leading candidates for thermochemical energy transport either within a distributed solar receiver system or over long distances. The Schaeffer Solar Furnace consists of a 96 square meter heliostat and a 7.3 meter diameter dish concentrator with a 65-degree rim angle and a 3.5 meter focal length. Measurements have shown a peak concentration ratio of over 10,000 and a total power of 15 kW at an insolation of 800 w/square meter. The receiver/reactor contains seven catalyst-filled tubes inside an evacuated metal box containing sodium. The front surface of this box serves as the solar absorber of the receiver. In operation, concentrated sunlight heats the 1/8-inch Inconel plate and vaporizes sodium from the wire-mesh wick attached to the back of it. The sodium vapor condenses on the reactor tubes, releases its latent heat, and returns by gravity to the wick. Test results and areas for future development are discussed.

Diver, R.B.; Fish, J.D.; Levitan, R.; Levy, M.; Rosin, H.; Richardson, J.T.

1988-01-01T23:59:59.000Z

325

Heat Pipe Performance Enhancement with Binary Mixture Fluids that Exhibit Strong Concentration Marangoni Effects  

E-Print Network (OSTI)

A.C. , 2005, “The effect of condenser heat transfer on theof 5mm between the condenser and adiabatic sections thatextraction at the condenser. Several k-type thermocouples

Armijo, Kenneth Miguel

2011-01-01T23:59:59.000Z

326

The flow structure under mixed convection in a uniformly heated vertical pipe  

E-Print Network (OSTI)

For decay heat removal systems in the conceptual Gas-cooled Fast Reactor (GFR) currently under development, passive emergency cooling using natural circulation of a gas at an elevated pressure is being considered. Since ...

Lee, Jeongik

2005-01-01T23:59:59.000Z

327

Assessing Consumer Values and the Supply-Chain Market for the Integrated Water Heater/Dehumidifier  

SciTech Connect

This paper presents a case study of the potential market for the dual-service residential integrated water heater/dehumidifier (WHD). Its principal purpose is to evaluate the extent to which this integrated appliance might penetrate the residential market sector, given current market trends, producer and consumer attributes, and technical parameters. The report's secondary purpose is to gather background information leading to a generic framework for conducting market analyses of technologies. This framework can be used to assess market readiness as well as factor preferred product attributes into the design to drive consumer demand for this product. This study also supports analysis for prototype design. A full market analysis for potential commercialization should be conducted after prototype development. The integrated WHD is essentially a heat-pump water heater (HPWH) with components and controls that allow dedicated dehumidification. Adequate residential humidity control is a growing issue for newly constructed residential homes, which are insulated so well that mechanical ventilation may be necessary to meet fresh air requirements. Leveraging its successful experience with the energy-efficient design improvement for the residential HPWH, the Oak Ridge National Laboratory's (ORNL's) Engineering Science and Technology Division's (ESTD's) Building Equipment Group designed a water-heating appliance that combines HPWH efficiency with dedicated dehumidification. This integrated appliance could be a low-cost solution for dehumidification and efficient electric water heating. ORNL is partnering with Western Carolina University, Asheville-Buncombe Technical Community College, American Carolina Stamping Company, and Clemson University to develop this appliance and assess its market potential. For practical purposes, consumers are indifferent to how water is heated but are very interested in product attributes such as initial first cost, operating cost, performance, serviceability, product size, and installation costs. The principal drivers for penetrating markets are demonstrating reliability, leveraging the dehumidification attributes of the integrated WHD, and creating programs that embrace first-cost and life-cycle cost principles.

Ashdown, BG

2005-01-11T23:59:59.000Z

328

ANALYSIS OF THE HEAT GENERATION IN THE PRIMARY SODIUM PIPE TUNNELS, INTERMEDIATE HEAT EXCHANGER CELLS, AND THE PRIMARY SODIUM FILL TANK VAULT FOR THE HALLAM NUCLEAR POWER FACILITY (HNPF)  

SciTech Connect

I. An adequate and conservative calculational method for evaluation of the heat generation distribution in the primary sodium system substructural areas was developed. The method was programed for the IBM 704 and the IBM 709. The results obtained from analysis of the gamma heat generation in the primary sodium pipe tunnels and in the intermediate heat exchanger cells are presented. Calculations are outlined, and gamma attenuation coefficients for concrete, sodium, and steel are given. II. Results obtained from analysis of the gamma heat generation in areas where the primary sodium system piping layout was changed from that of the previous analysis are presented. Major changes in magnitude of the hot spot heat generation due to the changes are pointed out. (auth)

Legendre, P.J.

1959-03-27T23:59:59.000Z

329

EVALUATION OF THE THERMAL AND HYDRAULIC PERFORMANCES OF A VERY THIN SINTERED COPPER FLAT HEAT PIPE FOR 3D MICROSYSTEM PACKAGES  

E-Print Network (OSTI)

The reported research work presents numerical studies validated by experimental results of a flat micro heat pipe with sintered copper wick structure. The objectives of this research were to produce and demonstrate the efficiency of the passive cooling technology (heat pipe) integrated in a very thin electronic substrate that is a part of a multifunctional 3-D electronic package. The enhanced technology is dedicated to the thermal management of high dissipative microsystems having heat densities of more than 10W/cm2. Future applications are envisaged in the avionics sector. A 2D numerical hydraulic model has been developed to investigate the performance of a very thin flat micro heat pipe with sintered copper wick structure, using water as a refrigerant. Finite difference method has been used to develop the model. The model has been used to determine the mass transfer and fluid flow in order to evaluate the limits of heat transport capacity as functions of the dimensions of the wick and the vapour space and for various copper spheres radii. 1.

Slavka Tzanova; Lora Kamenova; Yvan Avenas; Christian Schaeffer

2008-01-01T23:59:59.000Z

330

Internal flow patterns on heat transfer characteristics of a closed-loop oscillating heat-pipe with check valves using ethanol and a silver nano-ethanol mixture  

Science Conference Proceedings (OSTI)

The aim of this research was to investigate the internal flow patterns and heat transfer characteristics of a closed-loop oscillating heat-pipe with check valves (CLOHP/CV). The ratio of number of check valves to meandering turns was 0.2. Ethanol and a silver nano-ethanol mixture were used as working fluids with a filling ratio of 50% by total volume of tube. The CLOHP/CV was made of a glass tube with an inside diameter of 2.4 mm. The evaporator section was 50 mm and 100 mm in length and there were 10 meandering turns. An inclination angle of 90 from horizontal axis was established. The evaporator section was heated by an electric heater and the condenser section was cooled by distilled water. Temperature at the evaporator section was controlled at 85 C, 105 C and 125 C. The inlet and outlet temperatures were measured. A digital camera and video camera were used to observe the flow patterns at the evaporator. The silver nano-ethanol mixture gave higher heat flux than ethanol. When the temperature at the evaporator section was increased from 85 C to 105 C and 125 C. It was found that, the flow patterns occurred as annular flow + slug flow, slug flow + bubble flow and dispersed bubble flow + bubble flow respectively. The main regime of each flow pattern can be determined from the flow pattern map ethanol and a silver nano-ethanol mixture. Each of the two working fluids gave corresponding flow patterns. (author)

Bhuwakietkumjohn, N.; Rittidech, S. [Heat Pipe and Thermal Tools Design Research Laboratory (HTDR), Faculty of Engineering, Mahasarakham University, Mahasarakham 44150 (Thailand)

2010-11-15T23:59:59.000Z

331

International Heat Pipe Conference (13th IHPC), Shanghai, China, September 21-25, 2004.  

E-Print Network (OSTI)

-bubble distribution (uneven void fraction) in the tube sections, due to the dominance of surface tension forces [8]. #12; +($7 75$16)(5 0(&+$1,60 One end of the PHP tube bundle receives heat, transferring by the following basic features (refer Figure 1): (a) The structure is made of a meandering/ serpentine tube

Khandekar, Sameer

332

2102, Page 1 Experimental Investigation of Closed Loop Oscillating Heat Pipe as the  

E-Print Network (OSTI)

improvement in the coefficient of performance (COP) of a commercial heat pump using a mixture of refrigerants can be removed with the intent of performing composition analyses on them. The copper condenser commercial product, process, or serviceby trade name, trademark, manufacturer, or otherwise, does

Ghajar, Afshin J.

333

Numerical Investigation of Heat Transfer to Fully Developed Turbulent Air Flow in a Concentric Pipe  

Science Conference Proceedings (OSTI)

Numerical simulation using standard k-e turbulencemodel was developed to investigate numerically thecharacteristic of backward-facing step flow in a concentricpipe. This research is focused on the surface temperature, localheat transfer coefficient and ... Keywords: Numerical Simulation, Heat Transfer, Turbulent Flow, Computational Fluid Dynamics, Backward Facing Step

Cheen Sean Oon, Ahmad Badarudin, Salim Newaz Kazi, Arif Syazwan

2013-09-01T23:59:59.000Z

334

Overview: Home Cooling Systems | Department of Energy  

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

than earlier models. Dehumidifying heat pipes can help an air conditioner remove humidity and more efficiently cool the air. Radiant Cooling Radiant cooling cools a floor or...

335

Quantitative model of vapor dominated geothermal reservoirs as heat pipes in fractured porous rock  

DOE Green Energy (OSTI)

We present a numerical model of vapor-dominated reservoirs which is based on the well-known conceptual model of White, Muffler, and Truesdell. Computer simulations show that upon heat recharge at the base, a single phase liquid-dominated geothermal reservoir in fractured rock with low matrix permeability will evolve into a two-phase reservoir with B.P.D. (boiling point-for-depth) pressure and temperature profiles. A rather limited discharge event through cracks in the caprock, involving loss of only a few percent of fluids in place, is sufficient to set the system off to evolve a vapor-dominated state. The attributes of this state are discussed, and some features requiring further clarification are identified. 26 refs., 5 figs.

Pruess, K.

1985-03-01T23:59:59.000Z

336

Applicability of Related Data, Algorithms, and Models to the Simulation of Ground-Coupled Residential Hot Water Piping in California  

E-Print Network (OSTI)

Outdoor Temperature for District Heating Systems. ” ASHRAEAssessment of Buried District Heating Piping. ” ASHRAE

Warner, J.L.

2009-01-01T23:59:59.000Z

337

Development of a simplified model for cooling and dehumidifying coils  

E-Print Network (OSTI)

Precise understanding of the cooling coil in air handler units is vital to assure the proper temperature and humidity in conditioned space while minimizing the associated costs of operating the air conditioning system. Several models have been developed in the past to characterize the overall heat transfer coefficient of this component. However, these models require specific details about the coil construction which make them impractical for in-situ applications. A simplified engineering model suitable for application to existing coils in the field is therefore needed in the heating, ventilating, and air conditioning (HVAC) industry. The objective of this study is to develop a simplified model suitable for use with field measured data to characterize the overall heat transfer coefficient of in-situ water-to-air cooling coils. This model uses the electrical resistance analogy to treat the heat transfer process in the coil. Field measured data combined with a theoretical analysis are the basis for the development of the model. Non-linear regressions are applied to the data to trace the heat transfer behavior of the coil. The coefficients obtained from the regressions account for the physical characteristics of the coil under study as well as for the properties of the fluids involved (air and water). The calibration of these parameters to data generated by a coil manufacturer's simulation program allows the application of the resulting model to different types of cooling coils with different characteristics. Correlations are developed to predict the coefficients of the model and make it suitable for application to water cooling coils with a range of physical characteristics. The resulting model is validated by testing it on data from two different buildings at Texas excellent in both cases, predicting the thermal resistance of the coils and the return water temperature with an average deviation of 3.5% and 1.2 'F, respectively. Finally, the model is used to develop algorithms to simulate the two most common chilled water loops in buildings: the two-way valve and the blending station arrangement. These algorithms are incorporated in software developed at the Energy Systems Laboratory at Texas A&M University, College Station, which is used to simulate building heating, cooling and energy consumption based on a simplified air-side model. This addition enhances the capability of the software to simulate the response of the water-side to changes occurring in the space conditioning area, providing, in this way, a clear picture of the heat transfer phenomena that occurs in the cooling coil. The upgraded software was tested on a campus building and there was good agreement between the conditions.

Maldonado, Eliezer

1997-01-01T23:59:59.000Z

338

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

339

Pipe support  

DOE Patents (OSTI)

A pipe support for high temperature, thin-walled piping runs such as those used in nuclear systems. A section of the pipe to be supported is encircled by a tubular inner member comprised of two walls with an annular space therebetween. Compacted load-bearing thermal insulation is encapsulated within the annular space, and the inner member is clamped to the pipe by a constant clamping force split-ring clamp. The clamp may be connected to pipe hangers which provide desired support for the pipe.

Pollono, Louis P. (Hempfield Township, Hempfield County, PA)

1979-01-01T23:59:59.000Z

340

On the use of the parabolic concentration profile assumption for a rotary desiccant dehumidifier  

SciTech Connect

The current work describes a model for a desiccant dehumidifier which uses a parabolic concentration profile assumption to model the diffusion resistance inside the desiccant particle. The relative merits of the parabolic concentration profile model compared with widely utilized rotary desiccant wheel models are discussed. The periodic steady-state parabolic concentration profile model developed is efficient and can accommodate a variety of materials. These features make it an excellent tool for design studies requiring repetitive desiccant wheel simulations. A quartic concentration profile assumption was also investigated which yielded a 2.8 percent average improvement in prediction error over the parabolic model.

Chant, E.E. [Univ. of Turabo, Gurabo (Puerto Rico); Jeter, S.M. [Georgia Inst. of Technology, Atlanta, GA (United States). George W. Woodruff School of Mechanical Engineering

1995-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Electric Resistance Heating | Department of Energy  

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

room. Baseboard heaters contain electric heating elements encased in metal pipes. The pipes, surrounded by aluminum fins to aid heat transfer, run the length of the baseboard...

342

Gary Phetteplace August 1995 Optimal Design of Piping Systems  

E-Print Network (OSTI)

Gary Phetteplace August 1995 Optimal Design of Piping Systems for District Heating CRRELREPORT95 First, a method for determining the optimal size for a single pipe segment in a district heating system be feasible for designing the piping networks for district heating systems of moderate size, and its major

343

Geothermal district piping - A primer  

DOE Green Energy (OSTI)

Transmission and distribution piping constitutes approximately 40 -60% of the capital costs of typical geothermal district heating systems. Selections of economical piping suitable for the fluid chemistry is critical. Presently, most piping (56%) in geothermal systems is of asbestos cement construction. Some fiberglass (19%) and steel (19%) is also in use. Identification of an economical material to replace asbestos cement is important to future project development. By providing information on relative costs, purchase considerations, existing material performance and new products, this report seeks to provide a background of information to the potential pipe purchaser. A brief discussion of the use of uninsulated piping in geothermal district heating systems is also provided. 5 refs., 19 figs., 1 tab.

Rafferty, K.

1989-11-01T23:59:59.000Z

344

DRAFT INTERIM REPORT: NATIONAL PROGRAM PLAN FOR PASSIVE AND HYBRID SOLAR HEATING AND COOLING  

E-Print Network (OSTI)

etc. Heat Exchangers Heat Pipes & Thermal Diodes ConceptJ. Heat Exchangers K. Heat Pipes & Thermal Diodes A. Conceptwith two control, one heat pipe, and one cooling study. In

Authors, Various

2012-01-01T23:59:59.000Z

345

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

346

Comparison of the performance of open cycle air conditioners utilizing rotary desiccant dehumidifiers  

DOE Green Energy (OSTI)

This paper presents the results of an investigation of open cycle cooling systems using rotary desiccant dehumidifiers. Three systems, the ventilation, recirculation, and Dunkle cycles have been modeled. The performance of these systems coupled with an air-based solar system has been determined using TRNSYS simulations of system operation in four representative US climates. The system COP, fraction of the total cooling load met by the desiccant system, and fraction of the thermal energy provided by solar energy are compared. An assessment of the effect of climate and system parameters on the relative performance of the three system configurations is made. It is shown that in order to meet residential loads of 7 to 11 kW with a COP on the order of unity, systems with high effectiveness must be employed. These systems were also found to perform well when operated solely with a solar thermal input.

Jurinak, J.J.; Beckman, W.A.

1985-01-01T23:59:59.000Z

347

SERI Desiccant Cooling Test Facility. Status report. Preliminary data on the performance of a rotary parallel-passage silica-gel dehumidifier  

DOE Green Energy (OSTI)

This report describes the SERI Desiccant Cooling Test Facility. The facility can test bench-scale rotary dehumidifiers over a wide range of controlled conditions. We constructed and installed in the test loop a prototype parallel-passage rotary dehumidifier that has spirally wound polyester tape coated with silica gel. The initial tests gave satisfactory results indicating that approximately 90% of the silica gel was active and the overall Lewis number of the wheel was near unity. The facility has several minor difficulties including an inability to control humidity satisfactorily and nonuniform and highly turbulent inlet velocities. To completely validate the facility requires a range of dehumidifier designs. Several choices are available including constructing a second parallel-passage dehumidifier with the passage spacing more uniform.

Schultz, K.J.

1986-04-01T23:59:59.000Z

348

Optimization of Phase Change Heat Transfer in Biporous Media  

E-Print Network (OSTI)

transfer analysis of a loop heat pipe with biporous wicks”.Planes”. Frontiers in Heat Pipes Journal 1, 013001 (2010).transfer model of a loop heat pipe with a bidisperse wick

Reilly, Sean

2013-01-01T23:59:59.000Z

349

Development of a solar desiccant dehumidifier. Volume 1. Summary. Volume 2. Detailed technical information. Technical progress report  

DOE Green Energy (OSTI)

Research and development work aimed at the development of a solar desiccant dehumidifier is described in detail. The system features a rotary bed of granular silica gel and a rotary regenerator. The dehumidifier can be used for air conditioning through adiabatic saturation of the process airstream. Detailed technical information is presented in the appendices: (A) management, (B) review of the literature: state-of-the-art survey and SERI meeting, (C) review of the literature: adsorbent survey, (D) design requirements and evaluation criteria, (E) design requirements and evaluation criteria, single-family house model, (F) design requirements and evaluation criteria, economic model, (G) design requirements and evaluation criteria: conventional system models for comparison, (H) candidate cooling subsystems, (I) subsystem computer model, (J) subsystem performance map, and (K) subsystem preliminary design. (WHK)

Gunderson, M.E.; Hwang, K.C.; Railing, S.M.

1978-03-31T23:59:59.000Z

350

Exploring the Limits of Boiling and Evaporative Heat Transfer Using Micro/Nano Structures  

E-Print Network (OSTI)

8) (2006) [9] A. Faghri, Heat pipe science and technology,investigations on micro heat pipes, Int J Energ Res, 31(6-investigation of a high flux heat pipe heat sink, J Electron

Lu, Ming-Chang

2010-01-01T23:59:59.000Z

351

Pipe Insulation Economies  

E-Print Network (OSTI)

Pipe Insulation Economies is a computer program written in IBM basic to simplify the economic insulation thickness for an insulated pipe. Many articles have been written on this subject, from simple nomographs to a small book written in 1976 by the Federal Energy Administration, called "Economic Thickness for Industrial Insulation (ETI)." This paper is meant to fall somewhere between these extremes without sacrificing the accuracy necessary for economic considerations. Within this text, insulation is dealt with not as a material but as a method to slow heat transfer. To simplify the various mechanisms by which heat is transferred, the variable "thermal conductivity" is used. This is modeled for average insulation temperature. Another variable which has caused problems in the past is the ambient air film coefficient, or surface resistance. This program deals with this coefficient by making an initial assumption, then using an iterative process to refine the actual values before making the economic calculations. The program will use the input data to determine first of all the heat loss in BTU per hr/ft. of pipe. Using this result the lowest annual cost, therefore the most economical insulation thickness, is determined.

Schilling, R. E.

1986-06-01T23:59:59.000Z

352

Design and Analysis of High-Performance Air-Cooled Heat Exchanger with an Integrated Capillary-Pumped Loop Heat Pipe  

E-Print Network (OSTI)

We report the design and analysis of a high-power air-cooled heat exchanger capable of dissipating over 1000 W with 33 W of input electrical power and an overall thermal resistance of less than 0.05 K/W. The novelty of the ...

McCarthy, Matthew

353

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

heat flow in porous media, heat pipe, reservoir simulation,and vapor often leads to “heat-pipe” conditions, the steadytwo-phase zone, is the heat-pipe (i.e. , a zone of constant

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

354

TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems  

E-Print Network (OSTI)

A schematic of the heat pipe problem (from Updegraff [1989])19. A schematic of the heat pipe problem (from Updegraff[Numerical Modeling of a Porous Heat Pipe: Comparison with a

Moridis, G.J.

2010-01-01T23:59:59.000Z

355

A Hybrid Semi-Analytical and Numerical Method for Modeling Wellbore Heat Transmission  

E-Print Network (OSTI)

conductive heat supply, near the pipe, w h i c h explainsconductive heat exchange around a cylindrical pipe, we haveconductive heat supply to the cooling pipe. x=0 200 H and (

Pruess, Karsten; Zhang, Yingqi

2005-01-01T23:59:59.000Z

356

DETAILED LOOP MODEL (DLM) ANALYSIS OF LIQUID SOLAR THERMOSIPHONS WITH HEAT EXCHANGERS  

E-Print Network (OSTI)

DLM on the other hand con- pipes heat loss from ows. para 11~ headers~ connecting pipes~ and heat exchanger tubes) isconnecting pipes (riser and downcomer) and a heat exchanger

Mertol, A.

2013-01-01T23:59:59.000Z

357

Influence of Feeding Flow and Shrinkage Pipe Formation on ...  

Science Conference Proceedings (OSTI)

Presentation Title, Influence of Feeding Flow and Shrinkage Pipe Formation on ... CFD–Based Modelling on Interfacial Heat Transfer for Water Quenching.

358

Polyethylene Pipe Failure in the Arctic - Programmaster.org  

Science Conference Proceedings (OSTI)

In the current study, a new high density polyethylene (HDPE) pipe in the Arctic region of ... Heat Tint Effects on General Corrosion Resistance of Stainless Steels .

359

FEM Analysis of Pipe Reduction Forming Process for Increasing of ...  

Science Conference Proceedings (OSTI)

As a method of reducing a pipe to obtain a desired diameter, Kiuchi et al. propose a planetary ... Alloy Parts Heat Treatment Temperature Monitoring System.

360

Investigation of Unusual “Sharkskin” Corrosion in Drawn Copper Pipes  

Science Conference Proceedings (OSTI)

Alloy Parts Heat Treatment Temperature Monitoring System · Analysis of ... FEM Analysis of Pipe Reduction Forming Process for Increasing of Wall Thickness.

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

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

362

Fire Testing of High-Density Polyethylene Pipe  

Science Conference Proceedings (OSTI)

The results in this report are intended to demonstrate a method that can be used to protect high-density polyethylene (HDPE) piping located aboveground from postulated fire events. This includes protecting both pipe and pipe fittings (for example, elbows, tees, and valves) from the fire environmentincluding the heat transmitted from pipe supportsand preventing the fire environment from passing through building wall or floor penetrations. The report is intended to be complementary to other ongoing Electr...

2011-08-23T23:59:59.000Z

363

Self-contained passive solar heating system  

SciTech Connect

A self-contained passive solar heating system includes first and second heat pipes, each having a refrigerant medium therein, a condenser portion and an evaporator portion, with the condenser portion of the first heat pipe being coupled to the evaporator portion of the second heat pipe for transferring heat thereto when the pressure within the first heat pipe is greater than the pressure within the second heat pipe. The evaporator portion of the first heat pipe is adapted to be exposed to a source of heat and the condenser portion of the second heat pipe contacts a medium to be heated. A temperature control mechanism may be installed as the coupling between the first and second heat pipes for uncoupling the same when the temperature within the first heat pipe falls below a predetermined temperature. Also, a third heat pipe may be provided having a thermostatic portion operatively connected to the condenser portion of the second heat pipe by a piston means so that changes in pressure within the thermostatic portion occasioned by changes in temperature of the medium to be heated will cause movement of the pistons to vary the size of the condensing portion of the second heat pipe to increase or decrease the rate of heat transfer to the medium.

Maldonado, E.A.; Woods, J.E.

1983-05-10T23:59:59.000Z

364

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

365

THERMOSIPHON WATER HEATERS WITH HEAT EXCHANGERS  

E-Print Network (OSTI)

the collector and heat exchanger (Uc and Uhel · ~Constant tNational Standard, "Solar Heat Exchangers," ANSI/ASME SES 1,connecting pipes header heat exchanger insulation maximum

Mertol, Atila

2012-01-01T23:59:59.000Z

366

Modeling Thermal-Hydrologic Processes for a Heated Fractured Rock System: Impact of a Capillary-Pressure Maximum  

E-Print Network (OSTI)

Fig. 10b, c, d). Heat pipes can result from thethe temperature gradient in the heat- pipe zone is minimal,to the cool end of the heat pipe, and the liquid-phase ?ux

Sun, Y.; Buscheck, T. A.; Lee, K. H.; Hao, Y.; James, S. C.

2010-01-01T23:59:59.000Z

367

The Influence of Proposed Repository Thermal Load on Multiphase Flow and Heat Transfer in the Unsaturated Zone of Yucca Mountain  

E-Print Network (OSTI)

two-phase zone, is the heat-pipe (i.e. , a zone of constant4a), when there is a heat pipe just above the emplacementduring ventilation, the heat-pipe signature is absent in

Wu, Y.-S.; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, G.S.

2006-01-01T23:59:59.000Z

368

Integrated manufacturing system of high-pressure FRP pipes  

Science Conference Proceedings (OSTI)

In order to realise industrialised manufacturing of epoxy FRP pipes, the manufacturing system which can accomplish winding, internal heating curing and extraction processes by only one machine tool was developed. The winding motion control is undertaken ... Keywords: FEM, FRP pipes, blowing control, cooling control, curing control, embedded controllers, fibreglass reinforced plastics, finite element method, high-pressure pipes, integrated manufacturing, internal heating curing, motion control, simulation, thermochemical modelling, winding

Bo You; Jiazhong Xu; Xiongjian Wang

2007-11-01T23:59:59.000Z

369

The Advantages of HDPE Piping & Vaults in the  

E-Print Network (OSTI)

First in the world to produce 1600mm PE pipes Production of district heating pipes starts 1984 & telecom · Waste water treatment · House drainage · Under ground ventilation · Renovation · District heating & cooling · Special constructions · Marine intakes and outfalls · Welding, extrusion and blown

370

Savings Project: Insulate Hot Water Pipes for Energy Savings | Department  

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

Insulate Hot Water Pipes for Energy Savings Insulate Hot Water Pipes for Energy Savings Savings Project: Insulate Hot Water Pipes for Energy Savings Addthis Project Level Medium Energy Savings $8-$12 annually Time to Complete 3 hours for a small house Overall Cost $10-$15 Insulating water pipes can save you water, energy, and money. | Photo courtesy of iStockphoto.com/nsj-images Insulating water pipes can save you water, energy, and money. | Photo courtesy of iStockphoto.com/nsj-images Insulating your hot water pipes reduces heat loss and can raise water temperature 2°F-4°F hotter than uninsulated pipes can deliver, allowing for a lower water temperature setting. You also won't have to wait as long for hot water when you turn on a faucet or showerhead, which helps conserve water. Paying for someone to insulate your pipes-as a project on its own-may

371

Insulated pipe clamp design  

SciTech Connect

Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. The design considerations and methods along with the development tests are presented. Special considerations to guard against adverse cracking of the insulation material, to maintain the clamp-pipe stiffness desired during a seismic event, to minimize clamp restraint on the pipe during normal pipe heatup, and to resist clamp rotation or spinning on the pipe are emphasized.

Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

1980-01-01T23:59:59.000Z

372

Flexible ocean upwelling pipe  

DOE Patents (OSTI)

In an ocean thermal energy conversion facility, a cold water riser pipe is releasably supported at its upper end by the hull of the floating facility. The pipe is substantially vertical and has its lower end far below the hull above the ocean floor. The pipe is defined essentially entirely of a material which has a modulus of elasticity substantially less than that of steel, e.g., high density polyethylene, so that the pipe is flexible and compliant to rather than resistant to applied bending moments. The position of the lower end of the pipe relative to the hull is stabilized by a weight suspended below the lower end of the pipe on a flexible line. The pipe, apart from the weight, is positively buoyant. If support of the upper end of the pipe is released, the pipe sinks to the ocean floor, but is not damaged as the length of the line between the pipe and the weight is sufficient to allow the buoyant pipe to come to a stop within the line length after the weight contacts the ocean floor, and thereafter to float submerged above the ocean floor while moored to the ocean floor by the weight. The upper end of the pipe, while supported by the hull, communicates to a sump in the hull in which the water level is maintained below the ambient water level. The sump volume is sufficient to keep the pipe full during heaving of the hull, thereby preventing collapse of the pipe.

Person, Abraham (Los Alamitos, CA)

1980-01-01T23:59:59.000Z

373

Vapor spill pipe monitor  

DOE Patents (OSTI)

The invention is a method and apparatus for continually monitoring the composition of liquefied natural gas flowing from a spill pipe during a spill test by continually removing a sample of the LNG by means of a probe, gasifying the LNG in the probe, and sending the vaporized LNG to a remote ir gas detector for analysis. The probe comprises three spaced concentric tubes surrounded by a water jacket which communicates with a flow channel defined between the inner and middle, and middle and outer tubes. The inner tube is connected to a pump for providing suction, and the probe is positioned in the LNG flow below the spill pipe with the tip oriented partly downward so that LNG is continuously drawn into the inner tube through a small orifice. The probe is made of a high thermal conductivity metal. Hot water is flowed through the water jacket and through the flow channel between the three tubes to provide the necessary heat transfer to flash vaporize the LNG passing through the inner channel of the probe. The gasified LNG is transported through a connected hose or tubing extending from the probe to a remote ir sensor which measures the gas composition.

Bianchini, G.M.; McRae, T.G.

1983-06-23T23:59:59.000Z

374

Parallel-flow and counterflow conjugate convection in a vertical pipe  

SciTech Connect

The present paper investigate the problem of interaction (coupling) of forced convection inside a vertical pipe and natural convection outside the pipe. Both the cases of counterflow and parallel flow are considered. The problem finds applications in heat exchanger apparatuses of various types where a warm (cold) fluid is flowing inside a conductive pipe bathed in or surrounded by a colder (warmer) fluid. Clearly, the heat transfer through the pipe wall is a direct result of the interaction between the forced convection inside the pipe and the natural convection outside the pipe.

Libera, J.; Poulikakos, D. (Univ. of Illinois, Chicago (USA))

1990-08-01T23:59:59.000Z

375

Common Types of Pipe  

Science Conference Proceedings (OSTI)

...Reseamed and drifted pipe is similar to casing, but is manufactured and inspected in a manner that assures the well driller that the pipe string will have a predetermined minimum diameter sufficient to permit unrestricted passage of pumps or

376

CRAD, Nuclear Facility Construction - Piping and Pipe Supports Inspection -  

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

Construction - Piping and Pipe Supports Construction - Piping and Pipe Supports Inspection - March 29, 2012 CRAD, Nuclear Facility Construction - Piping and Pipe Supports Inspection - March 29, 2012 March 29, 2012 Nuclear Facility Construction - Piping and Pipe Supports Inspection Criteria, Approach and Lines of Inquiry (HSS CRAD 45-52, Rev. 0) For the purpose of this criteria review and approach, this Criteria Review and Approach Document (CRAD) includes piping and pipe supports and attachments of the pipe supports to structures (concrete, structural steel, or embed plates). Pipe supports include rigid restraints, welded attachments to piping, struts, snubbers, spring cans, and constant supports. Inspection of pipe whip restraints are also included in this CRAD. Selection of nuclear facility piping systems for inspection should be

377

Open cycle liquid desiccant dehumidifier and hybrid solar/electric absorption refrigeration system. Annual report, January 1993--December 1993. Calendar year 1993  

DOE Green Energy (OSTI)

This annual report presents work performed during calendar year 1993 by the Florida Solar Energy Center under contract to the US Department of Energy. Two distinctively different solar powered indoor climate control systems were analyzed: the open cycle liquid desiccant dehumidifier, and an improved efficiency absorption system which may be fired by flat plate solar collectors. Both tasks represent new directions relative to prior FSEC research in Solar Cooling and Dehumidification.

Nimmo, B.G.; Thornbloom, M.D.

1995-04-01T23:59:59.000Z

378

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

379

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

380

Passive heat transfer means for nuclear reactors  

DOE Patents (OSTI)

An improved passive cooling arrangement is disclosed for maintaining adjacent or related components of a nuclear reactor within specified temperature differences. Specifically, heat pipes are operatively interposed between the components, with the vaporizing section of the heat pipe proximate the hot component operable to cool it and the primary condensing section of the heat pipe proximate the other and cooler component operable to heat it. Each heat pipe further has a secondary condensing section that is located outwardly beyond the reactor confinement and in a secondary heat sink, such as air ambient the containment, that is cooler than the other reactor component. Means such as shrouding normally isolated the secondary condensing section from effective heat transfer with the heat sink, but a sensor responds to overheat conditions of the reactor to open the shrouding, which thereby increases the cooling capacity of the heat pipe. By having many such heat pipes, an emergency passive cooling system is defined that is operative without electrical power.

Burelbach, James P. (Glen Ellyn, IL)

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Determining the temperature field for cylinder symmetrical heat conduction problems in unsteady heat conduction in finite space  

Science Conference Proceedings (OSTI)

This paper proposes to present a new method to calculate unsteady heat conduction for cylinder symmetrical geometry. We will investigate the situation where the temperature field and heat flux created around a heat source placed in finite space are determined. ... Keywords: Garbai's integral equation, Laplace transformation, determining the temperate field, district heating pipes, geothermal producing pipe, heat flux density, heat loss, heat pump

László Garbai; Szabolcs Méhes

2007-05-01T23:59:59.000Z

382

A Better Steam Engine: Designing a Distributed Concentrating Solar Combined Heat and Power System  

E-Print Network (OSTI)

Vacuum tube liquid-vapor (heat-pipe) collectors. Proceedingsheat rejection in a condenser across a temperature gradient. This cycle ignores pressure losses in the pipes,

Norwood, Zachary Mills

2011-01-01T23:59:59.000Z

383

Nondestructive Evaluation: Ultrasonic Examination Techniques for High Density Polyethylene Pipes  

Science Conference Proceedings (OSTI)

High density polyethylene (HDPE) pipe has been used as a replacement material for buried carbon steel pipe in non-safety-related systems. Using the current butt fusion procedure that uses heat and pressure to melt and join two sections of plastic pipe, concerns have been raised that would indicate that the presence of decreased bond strength when the welding parameters for fusion set forth by the plastic pipe industry were not followed. Currently two utilities, Ameren UE at Callaway and Duke-Energy at Ca...

2011-11-15T23:59:59.000Z

384

Geothermal Heat Pump Basics | Department of Energy  

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

and a heat exchanger-a system of pipes buried in shallow ground. In the winter, the heat pump removes heat from the heat exchanger and pumps it into the indoor air delivery...

385

Heat recovery device for exhaust flues  

SciTech Connect

The heat recovery device has a flue pipe assembly including a section of standard flue pipe carrying a plurality of hollow, cylindrical heating tubes extending diametrically through the flue pipe section in axially spaced, parallel relationship and a separate housing defining an air flow chamber surrounding a portion of the flue pipe section. A fan inside the housing draws ambient air into the housing through an ambient air inlet located on the same side of the flue pipe assembly as the inlet of the heating tubes and propels a flow of air both through the heating tubes and over the outer surface of the flue pipe section towards a heated air outlet located on the same side of the flue pipe section as the discharge ends of the heating tubes. The flue pipe assembly is removably mounted on the housing so it can be removed in the event it fatigues and/or becomes plugged with carbon or creosote deposits during use. A thermostat on the flue pipe section turns the fan on and off when the temperature in the flue pipe section is respectively above and below a predetermined temperature. The total open area of the ambient air inlet and the heated air outlet is large enough so that, in the event the fan is inoperative, the natural flow of ambient air through the heating tubes and over the outer surface of the flue pipe is sufficient to prevent the flue pipe section from overheating.

Knoch, D. G.

1985-11-05T23:59:59.000Z

386

The Effect of Low Plasticity Burnishing on X65 Line Pipe Girth Welds ...  

Science Conference Proceedings (OSTI)

Presentation Title, The Effect of Low Plasticity Burnishing on X65 Line Pipe Girth Welds and Heat Affected Zones. Author(s), Peter Moore, Jeremy Scheel, Doug ...

387

Failure Analysis of an ERW Welded Pipe that Burst during Pressure ...  

Science Conference Proceedings (OSTI)

Presentation Title, Failure Analysis of an ERW Welded Pipe that Burst during ... Knowledge and Use of Heat Treating Procedures to Analyze the Cause of a Pair  ...

388

Sizing Relationships for Pipe Wall Preheater-710 Reactor Experiment  

SciTech Connect

Relationships presented as curves are given that permit selection of preheater pipe diameters and lengths consistent with objective pressure drops, wall temperatures, and heat addition. The data are for 710 reactor experiment coolant and operating conditions.

Moon, C.W.

1965-01-29T23:59:59.000Z

389

Evaluation of Pipe-Type Cable Joint Restraint Systems  

Science Conference Proceedings (OSTI)

Joints in underground transmission pipe-type cables must be designed to accommodate the thermomechanical forces created as a cable heats and cools in operation. This report details an investigation of several joint restraining designs and recommends one design.

1990-04-06T23:59:59.000Z

390

In situ heat treatment process utilizing a closed loop heating system  

Science Conference Proceedings (OSTI)

Systems and methods for an in situ heat treatment process that utilizes a circulation system to heat one or more treatment areas are described herein. The circulation system may use a heated liquid heat transfer fluid that passes through piping in the formation to transfer heat to the formation. In some embodiments, the piping may be positioned in at least two of the wellbores.

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

2010-12-07T23:59:59.000Z

391

Internal pipe attachment mechanism  

DOE Patents (OSTI)

An attachment mechanism is described for repairing or extending fluid carrying pipes, casings, conduits, etc. utilizing one-way motion of spring tempered fingers to provide a mechanical connection between the attachment mechanism and the pipe. The spring tempered fingers flex to permit insertion into a pipe to a desired insertion depth. The mechanical connection is accomplished by reversing the insertion motion and the mechanical leverage in the fingers forces them outwardly against the inner wall of the pipe. A seal is generated by crushing a sealing assembly by the action of setting the mechanical connection. 6 figures.

Bast, R.M.; Chesnut, D.A.; Henning, C.D.; Lennon, J.P.; Pastrnak, J.W.; Smith, J.A.

1994-12-13T23:59:59.000Z

392

Ceramic heat exchangers: manufacturing techniques and performance  

SciTech Connect

The objective of the ceramic heat pipe program being conducted at Los Alamos is demonstration of the practical feasibility of this technology for the solution of severe high temperature recuperation functions. Ceramic heat pipe recuperators have been theoretically shown to offer distinct advantages over conventional ceramic heat exchangers from the standpoint of efficiency of heat recuperation and economics. The main stumbling block to their widespread utilization is related to the problems of materials for construction and the details of fabrication and assembly. The performance objectives of ceramic heat pipes and some aspects of the materials technology program aimed at solving the problem of economic ceramic heat pipe fabrication are described.

Merrigan, M.A.; Sandstrom, D.J.

1981-01-01T23:59:59.000Z

393

Development of a solar-desiccant dehumidifier. Phase II second technical progress report  

DOE Green Energy (OSTI)

The solar desiccant air conditioner (SODAC) system and its operation are described, including the characteristics of the major components, the performance at design conditions, and the control schemes for optimum operation in various climates. The system uses granular silica gel as a desiccant. It may operate in either a recirculated mode (no air exchange between the outside and the conditioned space) or a ventilated mode (air exchanged between outside and conditioned space). The test data in the ventilated mode at design flow rates are presented. Data include outdoor and indoor inlet wet and dry bulb temperatures, indoor outlet dry and wet bulb temperatures, capacity, coefficient of performance, air flow rates, hot water temperature, and solar heat used. The effects of indoor, outdoor, and hot water temperatures on the capacity and coefficient of performance are shown graphically, and the recirculated and ventilated modes, performances are compared. (LEW)

Rousseau, J.

1981-10-16T23:59:59.000Z

394

Extendable pipe crawler  

DOE Patents (OSTI)

A pipe crawler is described having a front leg assembly and a back leg assembly connected together by two air cylinders, each leg assembly having four extendable legs and a pair of actuators for sliding the extendable legs radially outward to increase the range of the legs when the pipe crawler enters a section of a pipe having a larger diameter. The crawler crawls by inchworm'-like motion, the front leg assembly and back leg assembly alternately engaging and disengaging the wall of the pipe to hold the pipe crawler as the air cylinders alternately advance the front leg assembly and bring up the rear leg assembly. The pair of actuators of each leg assembly are parallel, adjacent and opposing acting so that each slides two adjacent extendable legs radially outward. 5 figures.

Hapstack, M.

1991-05-28T23:59:59.000Z

395

Extendable pipe crawler  

DOE Patents (OSTI)

A pipe crawler having a front leg assembly and a back leg assembly connected together by two air cylinders, each leg assembly having four extendable legs and a pair of actuators for sliding the extendable legs radically outward to increase the range of the legs when the pipe crawler enters a section of pipe having a larger diameter. The crawler crawls by inchworm''-like motion, the front leg assembly and back leg assembly alternately engaging and disengaging the wall of the pipe to hold the pipe crawler as the air cylinders alternately advance the front leg assembly and bring up the rear leg assembly. The pair of actuators of each leg assembly are parallel, adjacent and opposing acting so that each slides two adjacent extendable legs radially outward. 5 figs.

Hapstack, M.

1990-05-01T23:59:59.000Z

396

Development and Testing of Insulated Drill Pipe  

DOE Green Energy (OSTI)

This project has comprised design, analysis, laboratory testing, and field testing of insulated drill pipe (IDP). This paper will briefly describe the earlier work, but will focus on results from the recently-completed field test in a geothermal well. Field test results are consistent with earlier analyses and laboratory tests, all of which support the conclusion that insulated drill pipe can have a very significant effect on circulating fluid temperatures. This will enable the use of downhole motors and steering tools in hot wells, and will reduce corrosion, deterioration of drilling fluids, and heat-induced failures in other downhole components.

Champness, T.; Finger, J.; Jacobson, R.

1999-07-07T23:59:59.000Z

397

Optimization of Phase Change Heat Transfer in Biporous Media.  

E-Print Network (OSTI)

??As the heat transfer demands placed on small electronics devices increase, the demand for efficient evaporators for heat pipes and spreaders will increase in kind.… (more)

Reilly, Sean

2013-01-01T23:59:59.000Z

398

Heat Tint Effects on General Corrosion Resistance of Stainless Steels  

Science Conference Proceedings (OSTI)

The heat tint is usually created during a welding operation. The heat tint creates an oxide ... Reformer Inlet Hair-pin-pipe Weld Cracking · Remedy of Deficiencies

399

Piping stress handbook. Second edition  

Science Conference Proceedings (OSTI)

This abridged volume contains the following: Coefficients of thermal expansion. Allowable stress range for ANSI/ASME Power Piping Code B31.1. Stress intensification and flexibility factors. Pressure and stress ratios. Design criteria for allowable loads, moment, and stresses. Properties of pipe. Weight and dimensions of pipe and components. Pipe support selection and design. Fundamentals of expansion joints. Index.

Helguero, V.

1986-01-01T23:59:59.000Z

400

Flexible ultrasonic pipe inspection apparatus  

DOE Patents (OSTI)

Pipe crawlers, pipe inspection {open_quotes}rabbits{close_quotes} and similar vehicles are widely used for inspecting the interior surfaces of piping systems, storage tanks and process vessels for damaged or flawed structural features. This paper describes the design of a flexible, modular ultrasonic pipe inspection apparatus.

Jenkins, C.F.; Howard, B.D.

1994-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Service Water Piping Guideline  

Science Conference Proceedings (OSTI)

In the years 1988 and 1989, EPRI organized the Service Water Working Group (SWWG) to identify and help resolve the many issues surrounding service water (SW) systems in nuclear power plants. One issue identified by the SWWG was corrosion in service water piping systems. Interest in this issue resulted in the development of several technical reports: Guidelines for the Repair/Replacement Welding of Nuclear Service Water Systems, TR-100386; Guide for the Examination of Service Water System Piping, TR-10206...

2005-09-30T23:59:59.000Z

402

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

403

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

404

SATURATED-SUBCOOLED STRATIFIED FLOW IN HORIZONTAL PIPES  

Science Conference Proceedings (OSTI)

Advanced light water reactor systems are designed to use passive emergency core cooling systems with horizontal pipes that provide highly subcooled water from water storage tanks or passive heat exchangers to the reactor vessel core under accident conditions. Because passive systems are driven by density gradients, the horizontal pipes often do not flow full and thus have a free surface that is exposed to saturated steam and stratified flow is present.

Richard Schultz

2010-08-01T23:59:59.000Z

405

Alloy Parts Heat Treatment Temperature Monitoring System  

Science Conference Proceedings (OSTI)

Abstract Scope, The paper provides an automatic solution for monitoring and managing the heat treatment of drill pipes. It improves the efficiency and accuracy  ...

406

Modeling Satellite District Heating and Cooling Networks.  

E-Print Network (OSTI)

??Satellite District Heating and Cooling (DHC) systems offer an alternative structure to conventional, centralized DHC networks. Both use a piping network carrying steam or water… (more)

Rulff, David

2011-01-01T23:59:59.000Z

407

Building Energy Software Tools Directory: HEAT2  

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

internal modifications is 100 (one application is analysis of floor heating with many pipes). Conductances and capacities may be written to file. Temperature field may be...

408

Dehumidifiers | Open Energy Information  

Open Energy Info (EERE)

source History View New Pages Recent Changes All Special Pages Semantic SearchQuerying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook...

409

Exploring the Limits of Boiling and Evaporative Heat Transfer Using Micro/Nano Structures  

E-Print Network (OSTI)

a porous wick between the condenser and the evaporation. Theat the evaporator and condenser sections.. 26 Fig. 3.3a heat pipe Length of the condenser section in a heat pipe

Lu, Ming-Chang

2010-01-01T23:59:59.000Z

410

Apparatus for moving a pipe inspection probe through piping  

DOE Patents (OSTI)

A method and apparatus are disclosed for controllably moving devices for cleaning or inspection through piping systems, including piping systems with numerous piping bends therein, by using hydrostatic pressure of a working fluid introduced into the piping system. The apparatus comprises a reservoir or other source for supplying the working fluid to the piping system, a launch tube for admitting the device into the launcher and a reversible, positive displacement pump for controlling the direction and flow rate of the working fluid. The device introduced into the piping system moves with the flow of the working fluid through the piping system. The launcher attaches to the valved ends of a piping system so that fluids in the piping system can recirculate in a closed loop. The method comprises attaching the launcher to the piping system, supplying the launcher with working fluid, admitting the device into the launcher, pumping the working fluid in the direction and at the rate desired so that the device moves through the piping system for pipe cleaning or inspection, removing the device from the launcher, and collecting the working fluid contained in the launcher. 8 figs.

Zollinger, W.T.; Appel, D.K.; Lewis, G.W.

1995-07-18T23:59:59.000Z

411

Piping inspection instrument carriage  

DOE Patents (OSTI)

This invention, an instrument carriage for inspection of piping, comprises front and rear leg assemblies for engaging the interior of the piping and supporting and centering the carriage therein, an instrumentation arm carried by a shaft system running from front to rear leg assemblies. The shaft system has a screw shaft for moving the arm axially and a spline gear for moving the arm azimuthally. The arm has a pair of air cylinders that raise and lower a plate in the radial direction. On the plate are probes including, an eddy current probe and an ultrasonic testing probe. The ultrasonic testing probe is capable of spinning 360[degrees] about its axis.

Hapstack, M.; Talarek, T.R.; Zollinger, W.T.; Heckendorn, F.M. II; Park, L.R.

1991-01-01T23:59:59.000Z

412

Piping inspection instrument carriage  

DOE Patents (OSTI)

This invention, an instrument carriage for inspection of piping, comprises front and rear leg assemblies for engaging the interior of the piping and supporting and centering the carriage therein, an instrumentation arm carried by a shaft system running from front to rear leg assemblies. The shaft system has a screw shaft for moving the arm axially and a spline gear for moving the arm azimuthally. The arm has a pair of air cylinders that raise and lower a plate in the radial direction. On the plate are probes including, an eddy current probe and an ultrasonic testing probe. The ultrasonic testing probe is capable of spinning 360{degrees} about its axis.

Hapstack, M.; Talarek, T.R.; Zollinger, W.T.; Heckendorn, F.M. II; Park, L.R.

1991-12-31T23:59:59.000Z

413

What Have You Done to Ensure Your Water Pipes are Efficient and Safe? |  

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

Have You Done to Ensure Your Water Pipes are Efficient and Have You Done to Ensure Your Water Pipes are Efficient and Safe? What Have You Done to Ensure Your Water Pipes are Efficient and Safe? March 17, 2011 - 7:30am Addthis This week, Elizabeth told you about her unfortunate experience with burst pipes this winter. These accidents always seem to happen at the most inconvenient times and can be a real mess to fix and clean up. But there are a few things you can do to prevent them-namely, check your pipes and be sure they are insulated, especially if they are located in cold areas of your home. In addition, insulating your hot water pipes can help you save money and energy on water heating. What have you done to ensure your water pipes are efficient and safe? Each Thursday, you have the chance to share your thoughts on a question

414

What Have You Done to Ensure Your Water Pipes are Efficient and Safe? |  

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

What Have You Done to Ensure Your Water Pipes are Efficient and What Have You Done to Ensure Your Water Pipes are Efficient and Safe? What Have You Done to Ensure Your Water Pipes are Efficient and Safe? March 17, 2011 - 7:30am Addthis This week, Elizabeth told you about her unfortunate experience with burst pipes this winter. These accidents always seem to happen at the most inconvenient times and can be a real mess to fix and clean up. But there are a few things you can do to prevent them-namely, check your pipes and be sure they are insulated, especially if they are located in cold areas of your home. In addition, insulating your hot water pipes can help you save money and energy on water heating. What have you done to ensure your water pipes are efficient and safe? Each Thursday, you have the chance to share your thoughts on a question

415

Heat pipe cooling of metallurgical furnace equipment.  

E-Print Network (OSTI)

??Current water-cooling technology used in the metallurgical industry poses a major safety concern. In addition, these systems are expensive to operate and result in significant… (more)

Navarra, Pietro, 1979-

2006-01-01T23:59:59.000Z

416

Fracture toughness evaluations of TP304 stainless steel pipes  

SciTech Connect

In the IPIRG-1 program, the J-R curve calculated for a 16-inch nominal diameter, Schedule 100 TP304 stainless steel (DP2-A8) surface-cracked pipe experiment (Experiment 1.3-3) was considerably lower than the quasi-static, monotonic J-R curve calculated from a C(T) specimen (A8-12a). The results from several related investigations conducted to determine the cause of the observed toughness difference are: (1) chemical analyses on sections of Pipe DP2-A8 from several surface-cracked pipe and material property specimen fracture surfaces indicate that there are two distinct heats of material within Pipe DP2-A8 that differ in chemical composition; (2) SEN(T) specimen experimental results indicate that the toughness of a surface-cracked specimen is highly dependent on the depth of the initial crack, in addition, the J-R curves from the SEN(T) specimens closely match the J-R curve from the surface-cracked pipe experiment; (3) C(T) experimental results suggest that there is a large difference in the quasi-static, monotonic toughness between the two heats of DP2-A8, as well as a toughness degradation in the lower toughness heat of material (DP2-A8II) when loaded with a dynamic, cyclic (R = {minus}0.3) loading history.

Rudland, D.L.; Brust, F.W.; Wilkowski, G.M. [Battelle, Columbus, OH (United States)

1997-02-01T23:59:59.000Z

417

Drill pipe protector development  

DOE Green Energy (OSTI)

The Geothermal Drilling Organization (GDO), formed in the early 1980s by the geothermal industry and the U.S. Department of Energy (DOE) Geothermal Division, sponsors specific development projects to advance the technologies used in geothermal exploration, drilling, and production phases. Individual GDO member companies can choose to participate in specific projects that are most beneficial to their industry segment. Sandia National Laboratories is the technical interface and contracting office for the DOE in these projects. Typical projects sponsored in the past have included a high temperature borehole televiewer, drill bits, muds/polymers, rotary head seals, and this project for drill pipe protectors. This report documents the development work of Regal International for high temperature geothermal pipe protectors.

Thomerson, C.; Kenne, R. [Regal International Corp., Corsicanna, TX (United States); Wemple, R.P. [Sandia National Lab., Albuquerque, NM (United States)] [ed.] [and others

1996-03-01T23:59:59.000Z

418

Pipe-to-pipe impact analysis - Nuclear Engineering Multimedia  

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

Pipe-to-pipe impact analysis Pipe-to-pipe impact analysis Director's Welcome Organization Achievements Highlights Fact Sheets, Brochures & Other Documents Multimedia Library About Nuclear Energy Nuclear Reactors Designed by Argonne Argonne's Nuclear Science and Technology Legacy Opportunities within NE Division Visit Argonne Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Celebrating the 70th Anniversary of Chicago Pile 1 (CP-1) Argonne OutLoud on Nuclear Energy Argonne Energy Showcase 2012 Engineering Analysis Multimedia Bookmark and Share EA Multimedia, a collection of videos and audios featuring activities related to the Engineering Analysis Department Pipe-to-pipe impact analysis Quicktime video Quicktime Format - High Bandwidth | Size: 12 MB | Bit Rate:

419

Thermally Activated Desiccant Technology for Heat Recovery and Comfort  

DOE Green Energy (OSTI)

Desiccant cooling is an important part of the diverse portfolio of Thermally Activated Technologies (TAT) designed for conversion of heat for the purpose of indoor air quality control. Thermally activated desiccant cooling incorporates a desiccant material that undergoes a cyclic process involving direct dehumidification of moist air and thermal regeneration. Desiccants fall into two categories: liquid and solid desiccants. Regardless of the type, solid or liquid, the governing principles of desiccant dehumidification systems are the same. In the dehumidification process, the vapor pressure of the moist air is higher than that of the desiccant, leading to transfer of moisture from the air to the desiccant material. By heating the desiccant, the vapor pressure differential is reversed in the regeneration process that drives the moisture from the desiccant. Figure 1 illustrates a rotary solid-desiccant dehumidifier. A burner or a thermally compatible source of waste heat can provide the required heat for regeneration.

Jalalzadeh, A. A.

2005-11-01T23:59:59.000Z

420

What Have You Done to Ensure Your Water Pipes are Efficient and...  

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

help you save money and energy on water heating. What have you done to ensure your water pipes are efficient and safe? Each Thursday, you have the chance to share your thoughts on...

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Handbook of heat transfer applications (2nd edition)  

Science Conference Proceedings (OSTI)

The applications of heat transfer in engineering problems are considered. Among the applications discussed are: mass transfer cooling; heat exchangers; and heat pipes. Consideration is also given to: heat transfer in nonNewtonian fluids; fluidized and packed beds; thermal energy storage; and heat transfer in solar collectors. Additional topics include: heat transfer in buildings; cooling towers and ponds; and geothermal heat transfer.

Rohsenow, W.M.; Hartnett, J.P.; Ganic, E.N.

1985-01-01T23:59:59.000Z

422

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

423

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

424

Heat Treatment of Oil Country Goods and Tubular Products  

Science Conference Proceedings (OSTI)

Scope, Sponsored by HTS and the Houston Chapter of ASM, this symposium would focus an all aspects of heat treatment related to oil pipe, tube, drill bits, ...

425

SENSIBLE HEAT STORAGE FOR A SOLAR THERMAL POWER PLANT  

E-Print Network (OSTI)

Dry-Cooling Tower • Power-Generation Subsystem Summary AnGas-Circulation Subsystem The Power-Generation Subsystem Theinsulating plant piping. power-generation heat exchangers.

Baldwin, Thomas F.

2011-01-01T23:59:59.000Z

426

Corrosion Behavior of differently Heat Treated Steels in CCS ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Properties of pipe steels for CCS technology require resistance against the geothermal corrosive environment (heat, pressure, salinity of the ...

427

Design Principle and Strengthening of Advanced Austenitic Heat ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Unprecedented austenitic heat resistant steels strengthened by ... for application to tubes and pipes of advanced thermal power plants (A-USC).

428

Modeling Microstructure Evolution in the Heat Affected Zone of ...  

Science Conference Proceedings (OSTI)

An Evolutionary Approach for the Alloy and Heat Treatment Optimization of Low Alloyed ... Steel Plate Processing for Line Pipes in Oil and Gas Transport - A ...

429

An Evolutionary Approach for the Alloy and Heat Treatment ...  

Science Conference Proceedings (OSTI)

Control of the phase constitution can be achieved through a two-stage heat treatment: ... Steel Plate Processing for Line Pipes in Oil and Gas Transport - A ...

430

Designing, testing, and analyzing coupled, flux transformer heat.  

E-Print Network (OSTI)

??The proposed research involves designing, testing, and ics. analyzing a coupled, flux transformer heat pipe system following the patent of Oktay and Peterson (1997). Experiments… (more)

Renzi, Kimberly Irene

2012-01-01T23:59:59.000Z

431

Knowledge and Use of Heat Treating Procedures to Analyze the ...  

Science Conference Proceedings (OSTI)

The alloy would have been heat treated ? solution treated and aged ? to obtain ... Failure Analysis of an ERW Welded Pipe that Burst during Pressure Testing.

432

Geothermal heating system and method of installing the same  

SciTech Connect

A geothermal system and method of installing the same comprises the steps successively driving a drive pipe structure vertically into the ground at a plurality of locations so that a major portion of the length of the drive pipe structure is located below the frost line. An elongate geothermal pipe having closed ends is inserted into the drive pipe structure and its lower end is interlocked with a drive point device located at the lower end of the drive pipe structure. Thereafter, when the drive pipe is removed, the geothermal pipe remains anchored to the drive point. The geothermal pipes are connected together by conduits and connected to a heat pump so that a heat exchange liquid will be circulated through the system.

Kees, E.J.; Steiger, D.W.

1981-09-01T23:59:59.000Z

433

Aerogel Impregnated Polyurethane Piping and Duct Insulation ...  

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

Polyurethane Piping and Duct Insulation Aerogel Impregnated Polyurethane Piping and Duct Insulation Emerging Technologies Project for the 2013 Building Technologies Office's...

434

Pipe crawler with stabilizing midsection  

DOE Patents (OSTI)

A pipe crawler is described having a midsection that provides the stability and flexibility to allow the pipe crawler to negotiate curved and uneven segments of piping while traveling through piping systems. The pipe crawler comprises a front leg assembly, a rear leg assembly, a midsection with a gimbal at each end for connecting the midsection to the front and rear leg assemblies in a flexible manner, and an air cylinder for changing the distance between the front and rear leg assemblies. The pipe crawler moves in ''inch worm'' fashion with the front and rear leg assemblies alternating between an extended and a retracted position as the air cylinder moves the retracted leg assembly forward. The midsection has a plurality of legs extending radially for holding the midsection within a maximum displacement from the piping axis so that the gimbals are not pivoted to extreme angles where they might lock up or seize. When the midsection is displaced sufficiently, its legs with wheels on each end engage the interior surface of the piping and prevent further displacement. Using two gimbals divides the angle between the planes defined by the front and rear leg assemblies which also helps to prevent excessive gimbal pivoting. 5 figures.

Zollinger, W.T.; Treanor, R.C.

1994-12-27T23:59:59.000Z

435

Promethus Hot Leg Piping Concept  

SciTech Connect

The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept.

AM Girbik; PA Dilorenzo

2006-01-24T23:59:59.000Z

436

Functional capability of piping systems  

SciTech Connect

General Design Criterion I of Appendix A to Part 50 of Title 10 of the Code of Federal Regulations requires, in part, that structures, systems, and components important to safety be designed to withstand the effects of earthquakes without a loss of capability to perform their safety function. ne function of a piping system is to convey fluids from one location to another. The functional capability of a piping system might be lost if, for example, the cross-sectional flow area of the pipe were deformed to such an extent that the required flow through the pipe would be restricted. The objective of this report is to examine the present rules in the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Section III, and potential changes to these rules, to determine if they are adequate for ensuring the functional capability of safety-related piping systems in nuclear power plants.

Terao, D.; Rodabaugh, E.C.

1992-11-01T23:59:59.000Z

437

Pressure vessel and piping codes  

SciTech Connect

Section III of the ASME Boiler and Pressure Vessel Code contains simplified design formulas for placing bounds on the plastic deformations in nuclear power plant piping systems. For Class 1 piping a simple equation is given in terms of primary load stress indices (B/sub 1/ and B/sub 2/) and nominal pressure and bending stresses. The B/sub 1/ and B/sub 2/ stress indices reflect the capacities of various piping products to carry load without gross plastic deformation. In this paper, the significance of the indices, nominal stresses, and limits given in the Code for Class 1 piping and corresponding requirements for Class 2 and Class 3 piping are discussed. Motivation behind recent (1978-1981) changes in the indices and in the associated stress limits is presented.

Moore, S.E.; Rodabaugh, E.C.

1982-11-01T23:59:59.000Z

438

Passive heat-transfer means for nuclear reactors. [LMFBR  

DOE Patents (OSTI)

An improved passive cooling arrangement is disclosed for maintaining adjacent or related components of a nuclear reactor within specified temperature differences. Specifically, heat pipes are operatively interposed between the components, with the vaporizing section of the heat pipe proximate the hot component operable to cool it and the primary condensing section of the heat pipe proximate the other and cooler component operable to heat it. Each heat pipe further has a secondary condensing section that is located outwardly beyond the reactor confinement and in a secondary heat sink, such as air ambient the containment, that is cooler than the other reactor component. By having many such heat pipes, an emergency passive cooling system is defined that is operative without electrical power.

Burelbach, J.P.

1982-06-10T23:59:59.000Z

439

ESTIMATION OF THE TEMPERATURE RISE OF A MCU ACID STREAM PIPE IN NEAR PROXIMITY TO A SLUDGE STREAM PIPE  

SciTech Connect

Effluent streams from the Modular Caustic-Side Solvent Extraction Unit (MCU) will transfer to the tank farms and to the Defense Waste Processing Facility (DWPF). These streams will contain entrained solvent. A significant portion of the Strip Effluent (SE) pipeline (i.e., acid stream containing Isopar{reg_sign} L residues) length is within one inch of a sludge stream. Personnel envisioned the sludge stream temperature may reach 100 C during operation. The nearby SE stream may receive heat from the sludge stream and reach temperatures that may lead to flammability issues once the contents of the SE stream discharge into a larger reservoir. To this end, personnel used correlations from the literature to estimate the maximum temperature rise the SE stream may experience if the nearby sludge stream reaches boiling temperature. Several calculation methods were used to determine the temperature rise of the SE stream. One method considered a heat balance equation under steady state that employed correlation functions to estimate heat transfer rate. This method showed the maximum temperature of the acid stream (SE) may exceed 45 C when the nearby sludge stream is 80 C or higher. A second method used an effectiveness calculation used to predict the heat transfer rate in single pass heat exchanger. By envisioning the acid and sludge pipes as a parallel flow pipe-to-pipe heat exchanger, this method provides a conservative estimation of the maximum temperature rise. Assuming the contact area (i.e., the area over which the heat transfer occurs) is the whole pipe area, the results found by this method nearly matched the results found with the previous calculation method. It is recommended that the sludge stream be maintained below 80 C to minimize a flammable vapor hazard from occurring.

Fondeur, F; Michael Poirier, M; Samuel Fink, S

2007-07-12T23:59:59.000Z

440

Light pipe - design for efficiency  

Science Conference Proceedings (OSTI)

The high cost and availability of materials which are clear enough to transmit light without absorption has limited the idea of piping large-scale quantities of light. The light pipe uses the principle of Total Internal Reflection, with the light guided by very accurate prisms. The transmission of light directed into the end of a Light Pipe at an angle of less than 27.6 degrees is theoretically 100% efficient. The author describes its uses and advantages for lighting offices, cold storage areas, difficult access and hazardous areas, and for solar lighting. Future directions will be to improve the economics and accuracy of the technology. 4 references, 2 figures.

Hockey, S.N.

1985-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "dehumidifying heat pipes" 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

Leachate storage transport tanker loadout piping  

Science Conference Proceedings (OSTI)

This report shows the modifications to the W-025 Trench No. 31 leachate loadout discharge piping, and also the steps involved in installing the discharge piping, including dimensions and welding information. The installation of the discharge pipe should be done in accordance to current pipe installation standards. Trench No. 31 is a radioactive mixed waste land disposal facility.

Whitlock, R.W.

1994-11-18T23:59:59.000Z

442

Experiment System Analysis of an Indirect Expansion Solar Assisted Water Source Heat Pump Radiant Floor Heating System  

Science Conference Proceedings (OSTI)

A solar assisted water source heat pump for Radiant Floor Heating (SWHP-RFH) experimental system with heat pipe vacuum tube solar collector as heating source and radiant floor as terminal device is proposed in the paper. The Mathematics Model of dynamic ... Keywords: solar energy, water source heat pump, radiant floor heating systems, system dynamic COP

Qu Shilin; Ma Fei; Liu Li; Yue Jie

2009-10-01T23:59:59.000Z

443

In situ conversion process utilizing a closed loop heating system  

Science Conference Proceedings (OSTI)

An in situ conversion system for producing hydrocarbons from a subsurface formation is described. The system includes a plurality of u-shaped wellbores in the formation. Piping is positioned in at least two of the u-shaped wellbores. A fluid circulation system is coupled to the piping. The fluid circulation system is configured to circulate hot heat transfer fluid through at least a portion of the piping to form at least one heated portion of the formation. An electrical power supply is configured to provide electrical current to at least a portion of the piping located below an overburden in the formation to resistively heat at least a portion of the piping. Heat transfers from the piping to the formation.

Sandberg, Chester Ledlie (Palo Alto, CA); Fowler, Thomas David (Houston, TX); Vinegar, Harold J. (Bellaire, TX); Schoeber, Willen Jan Antoon Henri (Houston, TX)

2009-08-18T23:59:59.000Z

444

Thermal laminarization of a stratified pipe flow  

SciTech Connect

The present work constitutes a new program that grew out of a scoping assessment by ANL to determine the propensity for pipe stratification to occur in the reactor outlet nozzles and hot-leg piping