Showing papers on "Heat pipe published in 1973"

Heat pipe water heater

Abstract: A heat pipe using water as the heat transfer fluid transports heat to the water within a water heater storage tank from a gas fired burner external to and separate from the tank. The heat pipe is attached to the water heater by means of an adapter which permits the removal of the heat pipe from the water heater for repair and cleaning. The tank may be constructed of a plastic material which resists corrosion. The burner is a forced combustion type which permits efficient combustion of the natural gas and which reduces the loss of heat from the burner area.

External tube artery flexible heat pipe

Abstract: A flexible heat pipe employing external tube arteries in the adiabatic region to transfer the heat pipe working fluid from the wick contained in the condenser portion to the wick contained in the evaporator section.

Self-filling hollow core arterial heat pipe

Abstract: An arterial heat pipe is disclosed which is self-filling and has a high capacity. It comprises a porous structure that is disposed around a hollow core.

Cooling apparatus for flat semiconductors using one or more heat pipes

Abstract: An improved cooling apparatus for flat semiconductors in which the semiconductor is held between two base members each having one or more heat pipes inserted in holes formed therein. Heat is conducted by the vaporized working fluid in the heat pipe from the end inserted into the base member to other end which contains cooling fins which condense the vapor, which in liquid form then returns by capillary action through a wick.

Nonwicked heat-pipe cooled power semiconductor device assembly having enhanced evaporated surface heat pipes

Abstract: At least one of the two pressure plates used for mounting a replaceable power semiconductor device with pressure interfaces is utilized with an evaporating surface enhancement means as an evaporating surface in a nonwicked gravity-return heat pipe. This location of the evaporating surface in close proximity to the heat-emitting power semiconductor device decreases the steady-state thermal resistance as well as decreasing the transient temperature rise for long term heat overloads to produce improved vaporization cooling of the device.

Laminated heat pipe and method of manufacture

Abstract: A laminated heat pipe comprised of outer layers defining therebetween a heat pipe chamber, porous wick layers bonded to the inner surfaces of the outer layers, and an inner porous plenum layer located between and bonded to the wick layers. The porous wick layers are configured so that capillary flow of a contained working fluid will occur in the conventional manner, while the porous plenum layer is configured so that capillarity attraction thereto of the working fluid is lower than its attraction to the wick layers. Hence, the liquid phase working fluid is present substantially entirely in the wick layers, and the plenum layer provides both for a vapor flow path and structural support of the outer layers. The method of manufacture includes the step of first forming a laminate comprised of outer solid sheets, a pair of wick layers and an innermost sandwiched plenum layer all bonded together. The desired heat pipe configuration is then cut from the laminate, with the cut edge then sealed about its periphery save for a small opening through which the working fluid is introduced and which is subsequently sealed.

Equipment for exhaust gas detoxification in internal combustion engines

Abstract: An insulated heat pipe is provided which transfers heat from the engine's exhaust manifold to an exhaust gas reactor. The heat pipe contains a first zone serving as an evaporation zone, a second zone serving as a transport zone for transporting a working medium between the first zone and a third zone. The third zone serves as a condensation zone. The heat pipe has an interior capillary tube along which the condensed heat transfer medium flows toward the heat source and within which the vaporized medium flows toward the heat sink.

The heat pipe

Abstract: The heat pipe is a device having a high thermal conductance which utilizes the transport of a vapour and rejection of latent heat to achieve efficient thermal energy transport. The theory of heat pipes is well developed. Their use in applications involving temperatures in the cryogenic regime, and with development units running as high as 2000 degrees C, shows that they can function over a large part of the temperature spectrum. Applications in spacecraft, electronics and die casting are but few of the uses for these devices

Heat-pipe cooled power semiconductor device assembly having integral semiconductor device evaporating surface unit

Abstract: A power semiconductor device and thin cup members including the evaporating surface(s) of one (or two) nonwicked gravity-return heat pipe(s) are formed into a thin integral pressure interfacefree unit which requires only a low clamping force for connection of the unit to sidewalls of the heat pipe when the unit is replaceable in the assembly of the heat pipe(s) and power semiconductor device. No clamping is required if the unit is more permanently joined to the side walls of the heat pipe(s).

Heat pipe lobar wicking arrangement

Abstract: A heat pipe has the usual central wick for transporting a liquid, such as a cryogenic liquid, from end to end. A secondary wick transports liquid radially between the central wick and the wall of the heat pipe. This secondary wick is formed with lobes for contacting the heat pipe walls. In this manner, much of the wall surface is free of any contact with the wick, thereby providing improved heat transfer characteristics.

Spectroscopic observations of subsonic and sonic vapor flow inside an open-ended heat pipe

Abstract: Spectroscopic measurements of the vapor flow velocities inside a heat‐pipe oven have been performed as a function of pressure, heater power, and radial position inside the pipe. For this purpose the relative intensity of the collision‐induced satellite lines in laser‐induced resonance fluorescence spectra of the 7Li2 molecule has been employed. A one‐dimensional flow model is presented which determines the vapor parameters as a function of position along the pipe. It predicts the onset of the sonic flow which has been verified experimentally. A criterion is derived from which the parameters of the vapor can be obtained from the ideal gas relation, neglecting velocity‐dependent terms.

Air-o-space heater-means for recovering heat from a fluid stream

Abstract: The present invention constitutes a means for effectuating the partial recovery of heat normally lost through a flue pipe or exhaust stack of a domestic or industrial heating system. Use is made of a plurality of heat pipes secured in a fixed mutual relationship. Said plurality is partially extended into the flue pipe. Heat is axially transferred from the flue pipe and into an air duct that is equipped with a fan. The fan creates convection currents which serve to advance the recovered heat within the heat duct and ultimately back to either the industrial plant or residence wherein the recovered heat may be utilized for whatever heating purpose is desired.

Permafrost structural support with integral heat pipe means

Abstract: Structural support assembly for use in arctic and subarctic (permafrost) areas or in any areas where the upper ground layer is subject to a severe annual freeze-thaw cycle, including the cooperative combination of a support structure and a heat pipe element installed in generally frozen soil. The heat pipe is of a suitably complementary configuration and/or disposition with respect to the support structure to provide appropriate stabilization of the surrounding frozen soil. In one embodiment, the heat pipe element is disposed externally of the support structure and, in another embodiment, it is disposed internally of such structure. The external embodiment further includes one version employing a linear (straight) heat pipe element and another version employing an angular (helical) element. The internal embodiment further includes one version wherein a heat pipe is integrally combined with a support structure and another version wherein a heat pipe is cooperatively installed inside a support structure.

Cooling apparatus for the rotor of an electric machine which uses a heat pipe

Abstract: An improved cooling apparatus for the rotor of an electric motor in which a hollow center portion of the rotor has placed within it working fluid to cause the rotor to act as a heat pipe. The improvement comprises a fan placed over the end of the rotor shaft. The fan has a hollow portion in its hub which acts as an extension of the heat pipe thereby allowing the cooling vanes of the fan and the hub, which forms a part of inner heat pipe surface, to be made of one piece thereby allowing a more efficient heat transfer from the heat pipe to the cooling vanes.

Heat pipe interfaces

Abstract: An interface for interconnecting heat pipes is disclosed. The interface is itself a special purpose heat pipe adapted to efficiently transfer heat from the condenser of a first heat pipe to the evaporator of a second heat pipe. Using the present invention, simple heat pipes can be interconnected to form a complex heat pipe structure for particular applications.

Arrangement in heat exchangers

Abstract: This disclosure related to apparatus for transferring heat between two media located on opposite sides of a partition wall constructed of heat insulating material. A plurality of heat delivering heat pipes extend in spaced relation into one side of the wall and terminate in end portions having at least three equally extensive peripheral planar surfaces defining an equilateral transverse cross-section. A plurality of heat absorbing heat pipes extend in space relation into the other side of the wall and terminate in end portions of the same configuration as the end portions of the heat delivering heat pipes. The heat pipes are grouped and arranged with their respective end portions disposed in spaced overlapping relation and at least one of the end portions has at least three of its planar surfaces in spaced overlapping relation with the respective planar surfaces of at least three oppositely extending heat pipes. Thermoelectric means, having a cold end and a hot end when energized, are disposed between the spaced overlapping planar surfaces and in heat conducting connection therewith whereby heat may be transferred from the heat delivering heat pipes to the heat absorbing heat pipes. The end portions of the heat pipes have transverse cross-sections defining an equilateral triangle, a square, or a regular polygon.

Forced Convection Heat Transfer to Subcritical Helium I

Abstract: The intensive development of superconducting technology for electrical power equipment calls for a good knowledge of heat transfer to helium. Traditionally, simple bath cooling is used to provide the necessary rates of heat transfer to stabilize the conductor, and this appears still to be quite adequate in dc applications. However, in ac applications and various applications where large field sweep rates are experienced, either in normal operation or under fault conditions, losses occur and there may be design benefits from circulating the helium.

Cooling arrangement for a direct current power supply

Abstract: Apparatus and method for dissipating the heat generated by the components of a power supply. The components can be isolated from one another in a plurality of sealed compartments. Each isolated component can be thermally connected to a heat pipe which is operative to transfer heat generated by the respective component out of its sealed compartment to a heat sink which is in communication with ambient air currents.

Boiling Heat Transfer in an Open Thermosyphon : Report 1, An Experiment with Water

Abstract: An experiment on boiling heat transfer in a vertical open thermosyphon is performed. Tubes and annuli are used as the open thermosyphon. The latter consists of an unheated core and an externally heated tube. Data are taken using pure water by changing the diameter and the length of the heated tube, the diameter of the unheated core and the entrance temprature of the liquid. The heat transfer coefficient α is correlated with q0.4(Δts/Δt)0.9, where q is heat flux, Δts is excess wall temperature above saturation of the liquid, Δt is wall temperature minus entrance temperature of the liquid. It is also shown that the heat transfer coefficient is hardly affected by the length and the diameter of the heated tube. For the extremely small gap of the annulus, however, the heat transfer coefficient increases with a decreasing gap. The heat transfer coefficient in the thermosyphon is larger than that of pool boiling, but the critical heat flux is considerably smaller. Flow patterns in the open thermosyphon are observed and their relation with the heat transfer coefficient is discussed.

Structural heat pipe

Abstract: A combined structural reinforcing element and heat transfer member is disclosed for placement between a structural wall of a container or housing which is to be thermally protected and an outer insulation blanket disposed thereover and spaced apart therefrom. The element comprises a heat pipe, one side of which supports the outer insulation blanket, the opposite side of which is connected to the structural wall. Heat penetrating through the outer insulation blanket directly reaches the heat pipe and is drawn off, thereby reducing thermal gradients in the structural wall. The element, due to its attachment to the structural wall, further functions as a reinforcing member therefor.

Heat pipe turbo generator

Abstract: The adaptation of a heat pipe as a turbo-generator or other power output device for a reliable, quiet, light-weight high-endurance power source is shown. The device requires input thermal energy from a burner radioisotope (or solar heat) and also forced or natural heat rejection from condenser surfaces. Thermal energy conversion to a suitable power output is accomplished by encapsulating a turbine wheel within a heat pipe shell, located in an appropriately geometrical contoured section. Flow work extracted from the kinetic energy of the vapor flow provides rotary shaft power output. The shaft power can drive an electrical generator, pump, compressor, or similar device, also mounted within the heat pipe shell structure. A completely self-contained enclosed unit is provided which requires only external power connection at attachment terminals.

Heat pipe and manufacturing method thereof

Abstract: A heat pipe comprises a hollow wick impregnated with a liquid heat medium and an outer tubular cylinder within which the wick is installed and hermetically sealed. The wick is made up of a ribbon-shaped material of relatively narrow width wound in the form of a helix and is fabricated by winding the wick material preferably in alternately opposite helical directions on a mandrel, which is thereafter extracted to leave a hollow tubular wick.

Double-sided heat-pipe cooled power semiconductor device assembly using compression rods

Abstract: Two groups of rods disposed perpendicular to opposite ends of a replaceable power semiconductor device assembly have a compressive force applied thereto for causing uniform high pressure contact of two pressure plates against opposite ends of the semiconductor device assembly. The pressure plates are the evaporating surface ends of two heat pipes used for cooling the semiconductor device. The uniformly high pressure interfaces developed by the pressure plates within and against the semiconductor assembly results in a relatively low thermal resistance of the semiconductor device-to-heat pipe interfaces to produce improved vaporization cooling of the semiconductor device.

Traveling wave tube with heat pipe cooling

Abstract: A method and apparatus for efficiently removing heat from a traveling wave tube. A copper barrel heat sink casing is concentrically disposed about an inner glass or quartz tube with an annular space therebetween. Hollow ceramic spheres fill the space between the tube and the heat sink, and a small amount of fluid, such as a fluorocarbon serves as a vaporization agent to aid in the dissipation of the heat generated within the inner glass or quartz tube.

Hydrogen evolution in nickel-water heat pipes

Abstract: A study was made of the evolution of hydrogen gas in nickel-water heat pipes for the purpose of investigating methods of accelerated life testing. The data were analyzed in terms of a phenomenological corrosion model of heat pipe degradation which incorporates corrosion and oxidation theory and contains parameters which can be determined by experiment. The gas was evolved with a linear time dependence and an exponential temperature dependence with an activation energy of 1.03 x 10 to the minus 19th joules. A flow-rate dependence of the gas evolution was found in the form of a threshold. The results were used to predict usable lifetimes of heat pipes operated at normal operating conditions from results taken under accelerated operating conditions.