Showing papers on "Heat pipe published in 1974"

Two phase nozzle cooling system

Abstract: A two phase fuel injection nozzle cooling system having a hydraulically cooled heat pipe. The heat pipe contains a hermetically sealed cooling medium which has a boiling point corresponding to the upper range of acceptable nozzle operating temperatures to transfer heat from the nozzle tip to the circulating hydraulic fluid which operates as a heat sink.

Rotating heat pipe for air-conditioning

Abstract: 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 1G 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.

Electrohydrodynamic heat pipe experiments

Abstract: Experiments with two electrohydrodynamic heat pipes are reported. Both devices employ an electromechanical flow structure for axial liquid flow and a capillary wicking structure for (1) collection of condensed liquid at the cooled end and (2) distribution of this liquid at the heated end. One device has circumferential grooving for the capillary structure and the other has feltmetal wicking. The experiments successfully demonstrate the electrohydrodynamic heat pipe concept. Compatibility of the two circumferential wick structures with an axial electromechanical flow structure is also demonstrated. A significant mismatch of the capillary groove and electrohydrodynamic pumping capabilities results in severe hydrodynamic burn-out limiting in the first heat pipe. Both devices have very poor over-all thermal conductances of the order of 1-2 W/deg C, reflecting the generally poor heat-transfer properties of the dielectric working fluids required in electrohydrodynamic heat pipes.

Thermoelectric power system

Abstract: A thermoelectric power system particularly adaptable for use in outer space in which a nuclear reactor heats a working fluid, which in turn supplies heat to a plurality of thermoelectric generators spaced about a ring-shaped support. A first heat pipe is employed to couple heat between the hot fluid and hot junction of the thermoelectric element of each generator, and a second heat pipe couples heat away from the cold junction of each thermoelectric element. Each of the second heat pipes are elongated flexible units adapted to be folded upon launch of the system of a space vehicle and thereafter extended in space to provide a substantial area of radiation of heat to be discharged.

Efficient and nonpolluting method for recovering geothermal heat energy

Abstract: Geothermal heat is transferred from either dry or wet subterranean strata to a location at or neat the earth''s surface by a passive heat pipe extending into a well. The upper end of the heat pipe, to which the latent geothermal heat is transferred, extends into a steam chamber in which water is converted to steam used to drive a turbine generator or the like. After driving the turbine, the steam is condensed to liquid form and redirected into the steam chamber where it is once again converted to steam by the heat pipe. The utilization of a passive heat pipe means that nothing but heat is taken from the earth; hence, there is no land subsidence and no pollution. Further, the passive heat pipe eliminates the need for actively pumping a heat transfer fluid down through a well and back up to the surface.

Parametric performance of extruded axial grooved heat pipes from 100 to 300 K

Abstract: Extensive performance data derived from tests with an aluminum axial grooved extruded heat pipe is presented for oxygen, methane, ethane, and ammonia as working fluids. The effects of operating temperature, fluid inventory, heat flux, and elevation on the transport capability and the evaporator and condenser film coefficients are measured and compared to theory. The data correlation indicates that, in addition to the viscous pressure drop of the fluid, a vapor induced liquid pressure drop must be taken into account at temperatures near or below the normal boiling point of the fluid. Methane, ethane, and ammonia are all suitable working fluids for this groove geometry; however, oxygen, because of its low static height, is at best marginal in the 100-120 K range.

Method for closure of heat pipes and device fabricated thereby

Abstract: A plunger placed through an opening in a heat pipe enclosure is heated to a temperature above the saturation temperature of the working fluid in the heat pipe to prevent the fluid from condensing across the gap between the plunger and the opening and to allow non-condensible gases to escape. Thereafter, the plunger is melted to seal the heat pipe. The plunger and at least that part of the heat pipe with the opening therethrough are made from the same materials.

Heat pipe fabrication

Abstract: 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° angle with respect to the axis of the heat pipe.

Controllable heat pipe

Abstract: A heat pipe comprising a hermetically sealed hollow body which is filled with a saturated vapor of and a small amount of the condensate of a heat carrying fluid. The heat pipe communicates with the inside of an auxiliary body which also may contain a small amount of the condensate and vapor and which has associated therewith heat sink and heat source means by which the amount of vapor in the auxiliary body and in the hollow body may be regulated to control heat flow in the heat pipe.

Heat source containing radioactive nuclear waste

Abstract: A heat source includes packages or cans of radioactive heatproducing nuclear waste material contained in vertically disposed heating tubes immediately surrounded and cooled by a ''''spare'''' coolant at its boiling temperature which in turn is surrounded by a ''''primary'''' coolant from which useful heat is extracted Immediately above the primary coolant chamber is an emergency coolant chamber which cools vapors of the boiling liquid when an increase in heat caused by interruption of primary cooling causes an increase in the temperature of the boiling liquid so that vapors therefrom rise into a zone cooled by the emergency coolant Heat pipes having a portion in thermal contact with the top of heating tubes and a portion exposed to the atmosphere are provided as also are fused which permit the radioactive material to drop into a canal beneath the normal heat source zone should all other means for removing heat fail

Gravity assisted wick system for condensers, evaporators and heat pipes

Abstract: A wick system is disclosed comprising a casing, a wall capillary and a mesh screen wick having at least one artery structure used in conjunction with a closed or open system while in contact with the wall capillary. The wick system may be used in a vertical or inclined position with a condenser at the top.

Permafrost stabilizing heat pipe assembly

Abstract: A separable heat pipe assembly for stabilizing the generally frozen soil adjacent and supporting a structural member or foundation in permafrost or similar regions, including a cooperative combination of a sheath installed in the frozen soil and a closely mating heat pipe element normally inserted into the sheath with a substance of good thermal conductivity filling the small void remaining therebetween. The underground sheath preferably has a plurality of heat gathering fins and the mated heat pipe element preferably has an integral radiator section protruding aboveground. The thermal substance is preferably a liquid mixture of water and ethylene glycol, for example, mixed in a selected ratio. Another heat pipe installation includes a tubular structure installed in a permafrost environment, a heat pipe element having its lower portion installed in the structure and positioned at least in proximity longitudinally to the wall of the structure, and soil or other substances filling the space remaining between the lower element portion and the structure wall. The upper portion of the heat pipe element has a thicker wall than its lower portion and can be provided with threads thereon. A sleeve-type radiator can be provided with complementary threads therein so that the radiator can be threadedly engaged to the upper element portion. The depth and pitch of the threads can be changed to vary the heat transfer surface area obtainable between the engaged radiator and upper element portion. Alternatively, the radiator and upper element portion are not threaded but can be sized to provide for an interference press fit to secure them together. A lubricant-preservative-thermal substance can be used to fill any interface space between the mating surfaces of the threadedly engaged or press-fitted radiator and upper element portion.

Cooling arrangement for flat semiconductor components

Abstract: An improved cooling arrangement for flat semiconductor components such as disc-type thyristors in which the semiconductor component is clamped between two solid cooling elements with each cooling element carrying at least one heat pipe with attached cooling fins and in which a plurality of such cooling arrangements rotationally displaced are combined in a column-like cooling stack to achieve equally good cooling for all heat pipes.

Earth boring bit with means for conducting heat from the bit's bearings

Abstract: The present invention provides a rotary rock bit with a heat pipe for conducting heat from the bit's bearings. The rotary rock bit includes a bit body with a connection for connecting the bit body to a rotary drill string. At least one arm extends from the bit body and a rotatable cutter is mounted on said arm. Bearing means are located between the rotatable cutter and the arm for promoting rotation of the cutter. A heat pipe is positioned in the bit body and the heat pipe extends into the arm. The heat pipe includes an evaporator section located near the bearings and a condenser section located near the external surface of the bit.

Transverse variable conductance heat pipe

Abstract: A novel transverse variable conductance heat pipe is disclosed which is based on the combination of a wicked closed casing having an internal baffle for changing the direction of vapor flow, a vaporizable liquid, a non-condensible gas and a reservoir for the non-condensible gas.

Liquid fuel vaporizing device for internal combustion engines

Abstract: A liquid fuel vaporizing device for an internal combustion engine wherein a heat pipe containing a heat transfer fluid having a boiling point up to 400°C is disposed so that the heat transfer fluid transfers heat from a heat-receiving zone to a heat discharging zone which heat discharging zone is disposed to vaporize a mixture of said liquid fuel in the main portion or all of the combustion air.

Method of forming a wick for a heat pipe

Abstract: A method of forming a tubular wick for a heat pipe. The method is characterized by the steps of forming a wick blank of a predetermined thickness comprising a plurality of superimposed layers of stainless steel mesh screen, wet rolling the blank for reducing the thickness thereof, wrapping the blank about an inner mandrel, compressing the blank into a rigid tubular structure, removing the tubular structure from the mandrel and sintering the tubular structure.

Heat Pipe Cooled Induction Motor

Abstract: The feasibility of employing heat pipe cooling in an A-C Induction Motor has been demonstrated with the successful analysis, design and construction of an experimental motor. The heat pipes were integrally designed into both the rotor and stator of the motor allowing the heat absorbing section (evaporator) of the heat pipes to be placed as close as possible to the points of heat generation. The experimental portion of this effort demonstrated the thermal effectiveness of this configuration as well as supplying verification of a prior thermal analysis of this type of motor. The overall performance indicated the motor is applicable for adjustable speed operation at constant torque through an seven-to-one speed range as well as producing information on the operating characteristics under varying load and frequency conditions.

The Pebble Bed High Temperature Reactor as a Source of Nuclear Process Heat

Abstract: A theoretical analysis is given for a series of 8 different variants of the pebble-bed reactor in the "once through" fuel management scheme. The comparison brings the insight into the parametric sensitivities and into the development potential of this type. The thorium/U-233 recycling fuel cycle allows to increase the conversion ratio up to the range between 0.90 and 0.95. The feasibility is outlined for changing over between different fuel cycles under full power operation. The study is complemented by a review of the relevant previous researches.

Development of a blocking orifice thermal diode heat pipe

Abstract: A new geometry is described for low temperature diode heat pipes employing excess liquid to block the vapor space of the evaporator and part of the transport section during reverse mode conditions. An orifice plate is placed in the pipe at the blocking meniscus location, with the opening arranged to permit proper liquid distribution in both ground tests and zero 'g' operation. Parametric analytical results are presented for several fluids (carbon tetrafluoride, methane, and ethane). Experimental data is presented for a room temperature diode verifying feasibility, and a 1/4 in. O.D. cryogenic diode with methane working fluid.

Permafrost structural support with compatible 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.

Liquified gas evaporator

Abstract: An evaporator for converting a liquified gas such as chlorine into a superheated gas. The evaporator is constituted by a pressure vessel having a heat pipe vertically mounted therein, the lower end of the pipe projecting below the vessel and being coupled to a heat source whereby thermal energy from the source is transferred to the interior of the vessel. Liquified gas is fed into the vessel through an inlet pipe to form a pool in the lower zone thereof, in contact with the heat pipe. The gas evaporated from the heated pool is discharged through an outlet pipe.

Device for vaporizing liquid fuel

Abstract: A liquid containing heat pipe for vaporizing uncombusted fuel is disclosed having a liquid transfer storage zone and optionally separate heating means disposed to heat only part of the liquid in said pipe.

Closed evaporative cooling of rotating electrical machines

Abstract: Elements of a theory for centrifugo-axial heat pipes are described along with a calorimetric device for their experimental investigation. Experimental data presented confirms the fundamental correctness of the initial theoretical hypotheses.