Showing papers on "Heat pipe published in 1968"
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TL;DR: The VAPOR HEAT PIPE as mentioned in this paper is a closed, EVACUATED CHAMBER, whose interior wall is filled with a volatile fluid, which is used for transferring heat energy from one end of the pipe to the other.
Abstract: THE HEAT PIPE IS ESSENTIALLY A CLOSED, EVACUATED CHAMBER WHOSE INSIDE WALLS ARE LINED WITH A CAPILLARY STRUCTURE, OR WICK, THAT IS SATURATED WITH A VOLATILE FLUID. THE OPERATION OF THE HEAT PIPE COMBINES VAPOR HEAT TRANSFER AND CAPILLARY ACTION. VAPOR HEAT TRANSFER IS RESPONSIBLE FOR TRANSPORTING THE HEAT ENERGY FROM THE EVAPORATOR SECTION AT ONE END OF THE PIPE TO THE CONDENSER SECTION AT THE OTHER END. CAPILLARY ACTION IS RESPONSIBLE FOR RETURNING THE CONDENSED WORKING FLUID BACK TO THE EVAPORATOR SECTION. THE VAPORIZED FLUID STORES HEAT ENERGY AT THE TEMPERATURE AT WHICH THE VAPOR WAS CREATED AND WILL RETAIN THE ENERGY AT THAT TEMPERATURE UNTIL IT MEETS A COLDER SURFACE. THIS TENDENCY TO RESIST ANY DIFFERENCE IN TEMPERATURE WITHIN THE HEAT PIPE IS RESPONSIBLE FOR THE DEVICE'S HIGH THERMAL CONDUCTANCE. THE HEAT PIPE CAN OPERATE AGAINST GRAVITY AND WITHOUT A SECOND EXTERNAL ENERGY SOURCE. DEVICES THAT OPERATE ON THE PRINCIPLE OF VAPOR HEAT TRANSFER CAN HAVE SEVERAL THOUSAND TIMES THE HEAT-TRANSFER CAPACITY OF THE BEST METALLIC CONDUCTORS. HEAT PIPES HAVE BEEN MADE TO OPERATE AT VARIOUS TEMPERATURES SPANNING THE RANGE FROM BELOW FREEZING TO OVER 3,600 F. THE POWER TRANSFERRED RANGES FROM A FEW WATTS TO MORE THAN 17,000 WATTS. THE HEAT PIPE IS A UNIQUE AND VERSATILE HEAT-TRANSFER DEVICE. ITS SPECIAL PROPERTIES ARE HIGH THERMAL CONDUCTANCE, TEMPERATURE FLATTENING, HEAT-FLUX TRANSFORMATION AND SEPARATION OF HEAT SOURCE FROM HEAT SINK.
142 citations
54 citations
TL;DR: In this article, a cryostat is described which is capable of measuring specific heat and thermal conductivity of dielectric crystals over the temperature range 0.05 and 2.0°K.
Abstract: A cryostat is described which is capable of measuring specific heat and thermal conductivity of dielectric crystals over the temperature range 0.05 and 2.0°K. Thermal conductivity is measured with a steady flow of heat through the sample, and specific heat by a pulse technique. Differential carbon resistance thermometry is used for both measurements. The performance is demonstrated on the thermal conductivity of LiF, and on the specific heat of two samples of nominally pure KCl.
31 citations
Patent•
16 Oct 1968
TL;DR: The Disclosed Heat PIPE as mentioned in this paper is a HERMETICALLY SEALED CHAMBER with first and second-and third-regions of the world's largest working fluid.
Abstract: THE DISCLOSED HEAT PIPE INCLUDES A HERMETICALLY SEALED CHAMBER HAVING FIRST AND SECOND HEAT TRANSFER REGIONS. A FLUID CAPTURING WICK LOCATED IN THE VICINITY OF THE FIRST REGION AND A CAPILLARY WICK CONTAINING A VOLATILE WORKING FLUID ARE DISPOSED WITHIN THE CHAMBER. THE CAPILLARY WICK EXTENDS FROM THE FIRST TO THE SECOND REGION OF THE CHAMBER. WHEN HEAT IS APPLIED TO THE FIRST REGION, THE HEAT PIPE ACTS AS A THERMAL CONDUCTOR, TRANSFERRING HEAT FROM THE FIRST REGION TO THE SECOND REGION BY MEANS OF THE EVAPORATION AND SUBSEQUENT CONDENSATION OF THE WORKING FLUID. THE CONDENSED WORKING FLUID RETURNS TO THE FIRST REGION OF THE CHAMBER BY CAPILLARY ACTION VIA THE CAPILLARY WICK. WHEN HEAT IS APPLIED TO THE SECOND REGION OF THE CHAMBER, THE HEAT IS APPLIED TO THE PREVENT HEAT FLOW TO THE FIRST REGION.
25 citations
Patent•
04 Oct 1968
TL;DR: In this article, a heat transfer pipe containing a vaporizable fluid and having a porous wick on its inner surface is mounted in the tank of a railway tank car and extends into a furnace outside the tank.
Abstract: A heat transfer pipe containing a vaporizable fluid and having a porous wick on its inner surface is mounted in the tank of a railway tank car and extends into a furnace outside the tank. The outer end of the pipe communicated with a reservoir for the fluid. The wick has a plurality of porous metallic layers designed to provide good heat transfer, as well as a high degree of capillary action. Evaporation of the liquid produced by the furnace and condensation along the whole length of the pipe in the tank transfer a great amount of heat into the tank at a generally uniform temperature.
23 citations
Patent•
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04 Nov 1968
TL;DR: In this paper, a selectively operated mechanical valve within the vapor phase passage of a heat pipe was used to control the isothermal transfer of thermal energy, and the valve was shown to be effective in the case of a single heat pipe.
Abstract: A selectively operated mechanical valve within the vapor phase passage of a heat pipe to control the isothermal transfer of thermal energy.
21 citations
TL;DR: In this article, heat transfer and critical heat flux in saturated pool boiling were experimentally studied under transient power condition, where the heating elements were flat plates of nickel submerged facing vertical.
Abstract: Heat transfer and critical heat flux in saturated pool boiling were experimentally studied under transient power condition The heating elements were flat plates of nickel submerged facing vertical
21 citations
Patent•
16 Sep 1968
TL;DR: In this paper, a hermetically sealed housing with two portions electrically insulated from one another and maintained at differing electrical potentials is described, containing a volatile working fluid, a capillary wick and an inert gas having relatively high dielectric strength.
Abstract: The disclosed heat pipe includes a hermetically sealed housing having two portions electrically insulated from one another and maintained at differing electrical potentials. Contained within the housing is a volatile working fluid, a capillary wick and an inert gas having relatively high dielectric strength. Sufficient inert gas is contained within the housing to maintain a predetermined breakdown voltage at the lowest temperature of operation of the heat pipe.
19 citations
Patent•
06 Nov 1968TL;DR: In this paper, a moderated thermionic core assembly has been provided which employs vapor chamber condenser-cooled stacked thermionic fuel elements, which extracts excess heat from the collectors and transmits it to an external reflector.
Abstract: A moderated thermionic core assembly has been provided which employs vapor chamber condenser-cooled stacked thermionic fuel elements. A cylindrical moderator block is provided with a plurality of radial wells drilled in an ordered array about the periphery of the moderator block. Each well is adapted to receive a tubular fuel element which includes two series-connected nuclear fueled thermionic converter elements having a neutral plasma maintained between the emitter and collector electrodes of each converter. Each fuel element includes a vapor chamber condenser which extracts excess heat from the collectors and transmits it to an external reflector from which the excess heat is radiated to space.
Patent•
23 Dec 1968
TL;DR: The critical point heat pipe can serve as an auxiliary heat transport device for supplying heat from the exhaust gases of a vehicle engine to the vehicle compartment heat exchanger during engine warmup as discussed by the authors.
Abstract: The employment of a heat pipe as a passive, self-operating thermal energy transport valve which automatically thermally couples a heat source to a heat sink or decouples the same depending upon the operating temperature of the heat pipe and its relation to the critical point of the working fluid. The critical point heat pipe can serve as an auxiliary heat transport device for supplying heat from the exhaust gases of a vehicle engine to the vehicle compartment heat exchanger during engine warmup.
Patent•
05 Jun 1968
TL;DR: A heat transfer system for supplying a constant temperature to a heat utilization device including a heat transfer pipe having the utilization device mounted intermediate an alpha emitting radioisotope fuel for vaporizing the working fluid of the heat pipe and a heat exchanger for dissipating excess heat from the condenser portion of a heat pipe was proposed in this paper.
Abstract: A heat transfer system for supplying a constant temperature to a heat utilization device including a heat transfer pipe having the utilization device mounted intermediate an alpha emitting radioisotope fuel for vaporizing the working fluid of the heat pipe and a heat exchanger for dissipating excess heat from the condenser portion of the heat pipe, means for retaining helium generated by the radioisotope fuel and a passageway for transporting the helium to the interior of the heat pipe to maintain constant the internal pressure and vaporization temperature of the working fluid within the heat pipe as the rate of heat dissipation from the radioisotope decreases
TL;DR: Nuclear reactor space power system concept using thermionic diodes, heat pipes and rod control, emphasizing neutronic aspects and feasibility as mentioned in this paper, using a nuclear nuclear power system.
Abstract: Nuclear reactor space power system concept using thermionic diodes, heat pipes and rod control, emphasizing neutronic aspects and feasibility
01 Jul 1968
Abstract: The applicability of heat pipes to the solution of thermal control problems associated with future spacecraft, including the Saturn V workshop i s investigated. The investigation includes a survey of reported experience in heat pipe technology, an analysis of the effect of variation in various design parameters on heat pipe performance, and establishment of concepts utilizing the heat pipe which offer unique solutions to specific thermal control problems. Concepts a r e described and analyzed which appear applicable to the solution of problems of cryogenic boiloff control, temperature nonuniformity of skin s t ructure, removal of heat from concentrated sources and radiator design.
01 Mar 1968
TL;DR: In this article, the development of nuclear thermionic space power system using thermionic diodes and heat pipe flow for temperature control is described. But the authors focus on the use of nuclear energy for energy harvesting.
Abstract: Development of nuclear thermionic space power system using thermionic diodes, and heat pipe flow for temperature control
Patent•
11 Jan 1968TL;DR: A radial heat pipe as discussed by the authors has a plurality of radial struts covered with capillary lining which extend from an outer cylindrical heat output wall to an inner cylinrical heat input wall to assist in returning a working fluid from the heat output layer to the heat input layer.
Abstract: A radial heat pipe has a plurality of radial struts covered with capillary lining which extend from an outer cylindrical heat output wall to an inner cylindrical heat input wall to assist in returning a working fluid from the heat output wall to the heat input wall. A deformable metallic lining is attached to the outside of the cylindrical heat input wall to provide a close fit with and a good thermal path from a heat source member to the heat input wall. The heat pipe also has a tube extending down its central axis which permits force to be applied to the heat source member to separate the heat source member from the heat pipe.
Patent•
13 Nov 1968TL;DR: In this article, the authors describe an active core region of nuclear reactors where a high temperature line is provided to contain the Gaseous FUEL while permitting it to atTAIN TEMPERATURE where HEAT TRANSFER by THERMAL RADIATION is performed.
Abstract: NUCLEAR REACTORS ARE DESCRIBED IN WHICH FISSILE FUEL MATERIAL IN GASEOUS FORM IS UTILIZED AS AN ENERGY SOURCE FOR THE PRODUCTION OF ELECTRICAL POWER. THE ACTIVE CORE REGION OF SUCH REACTORS COMPRISES GASEOUS FUEL DISPOSED WITHIN A CAVITY OR CAVITIES AND SURROUNDED BY A MATRERIAL HAVING BOTH REFLECTOR AND MODERATOR PROPERTIES. A HIGH TEMPERATURE LINER IS PROVIDED TO CONTAIN THE GASEOUS FUEL WHILE PERMITTING IT TO ATTAIN TEMPERATURE WHERE HEAT TRANSFER BY THERMAL RADIATION PREDOMINATES WITHIN A CAVITY OR CAVITIES. THE HEAT REACHING THE CAVITY WALL OR WALLS IS CONVERTED TO ELECTRICAL ENERGY BY SEVERAL METHODS INCLUDING THE USE OF THERMIONIC CONVERTERS IMMEDIATELY ADJACENT THE WALL OR WALLS OR LOCATED REMOTELY THEREFROM, OR BY USING A CIRCULATING THERMODYNAMIC WORKING FLUID IN COMBINATION WITH THE THERMIONIC CONVERTERS AND PASSING IT THROUGH A CONVENTIONAL TURBOELECTRIC GENERATOR LOOP. D R A W I N G
01 Jun 1968
TL;DR: In this article, a thermal control subsystem for stationary Martian surface laboratory, selecting heat pipe radiator for daytime and electric heaters plus insulation for nighttime, is described, along with an experimental setup.
Abstract: Thermal control subsystem for stationary Martian surface laboratory, selecting heat pipe radiator for daytime and electric heaters plus insulation for nighttime
01 Jan 1968
TL;DR: In this article, heat pipes with Freon working fluid applied to thermal control of transponders in low altitude gravity gradient satellite GEOS-B were used for low altitude low gradient satellite.
Abstract: Heat pipes with Freon working fluid applied to thermal control of transponders in low altitude gravity gradient satellite GEOS-B
01 Jan 1968
TL;DR: In this article, the authors integrate heat pipe thermal radiator devices into the external suit surface to control the suit's internal temperature control by integration of heat pipe and thermal radiators, respectively.
Abstract: Space suit internal temperature control by integration of heat pipe thermal radiator devices into external suit surface
Patent•
03 Jul 1968
TL;DR: A heat pipe as mentioned in this paper is defined as a closed tubular container of heat resistant material and condensible vapour and capillary means disposed within the container, characterized in that the capillary passages are formed directly on the container wall and comprise grooves extending axially or helically of the tube.
Abstract: 1,118,468. Heat transfer devices. EUROPEAN ATOMIC ENERGY COMMUNITY (EURATOM). 16 Nov., 1965 [23 Nov., 1964], No. 48728/65. Headings F4S and F4U. A heat pipe, defined as a heat transfer device comprising a closed tubular container of heatresistant material and condensible vapour and capillary means disposed within the container, is characterized in that the capillary passages are formed directly on the container wall and comprise grooves extending axially or helically of the tube. The depth of each groove is preferably twice its width and the grooves are preferably of rectangular cross-section.