Showing papers on "Heat pipe published in 1977"

Heat pump system with improved heat transfer

Abstract: A heat pump for cooling or heating a conditioned space includes an underground heat pipe laid into a hole in the ground back-filled with soil. The heat transfer of the soil is improved by dispersing highly water-absorbent hydrophilic polymeric gel particles soaked with water around the heat pipe. The water-soaked particles preferably are coated with a water-impermeable film. The water may also be entrapped in liquid form in small bags. Also, a water impermeable sheath may be formed around the back-fill soil to minimize evaporation from the particles.

Storage arrangement for thermal energy

Abstract: Heat of liquefaction and solidification is transmitted between a heat storing material undergoing the phase transition and a heating medium in a heat exchanger by means of a partly gaseous, partly liquid fluid sealed in a heat pipe a portion of which is received in the container for the aforementioned material, and which is equipped with fins in direct contact with the heat storing material while a second portion of the heat pipe is in thermal contact with the heating medium in the heat exchanger.

Heat pipe thermal mounting plate for cooling electronic circuit cards

Abstract: Heat pipe technology may be utilized to cool circuit card-mounted electronic components A heat pipe thermal mounting pipe has a very high thermal conductivity and provides a relatively uniform temperature surface for attaching of circuit card-mounted electronic components It comprises thin evaporator and condenser wicks (for low temperature gradients) as well as a relatively porous sintered metal artery wick (for high heat transfer capability) The heat sink or other heat exchanger may be mounted at the edge of the thermal mounting plate in the vicinity of the condenser wick The electronic components are mounted in the vicinity of the evaporator wicks

Apparatus for cooling electrical components

Abstract: In a cooling assembly including a heat conductive block mounting an electronic part, and a heat pipe attached to the heat conductive block, a connector connected to the leads of the electronic part is arranged in the heat conductive block.

Focusing solar energy apparatus

Abstract: An apparatus employing cylindrical focusing parabolic mirrors (parabolic troughs) of an optimized configuration capable of being manufactured by techniques of mass production to focus sunlight onto a specifically designed heat pipe which is to carry water or other heat transfer fluid. Focused sunlight energy is absorbed by the pipe, converted to thermal energy and transferred to heat the fluid in the pipe. Groups of mirrors are sequentially arranged so that the fluid in the pipes progressively absorbs more heat as it travels through the heat pipe. At some point in the fluid movement, depending upon the intensity of the specular sunlight the fluid, if liquid, may be converted to vapor. Transfer liquids other than water with higher boiling points may be used within the heat pipe and exit from the heat pipe in the liquid state. In either case, the steam, hot gas or superheated liquid is transmitted to a collector system which is then transported by standard steam pipes enclosed within a silvered glass envelope to a central thermal/electrical generating station. Collector mirror arrays are mounted to permit a single tracking motor to steer a large number of mirrors. All components are optimized for low maintenance and low cost to manufacture.

Multi-source heat pump HVAC system

Abstract: An HVAC system for a building of the type that has an interior zone and a perimeter zone includes an economizer type air conditioning unit for the interior zone and a multi-source heat pump for the perimeter zone. The interior zone economizer type air-conditioning unit has a waste heat recovery coil disposed at the exhaust air dampers and connected in a closed liquid circulating loop for recovering heat from the exhausted air. The multi-source heat pump functions as an air-to-air heat pump during a cooling mode of operation during which heat is withdrawn from the air to be conditioned by standard indoor evaporator coils, said heat being rejected to the outside air by a standard outdoor condenser coil. The heat pump operates as liquid-to-air heat pump during the heating mode of operation during which heat is extracted by a chiller from the closed liquid circulating loop and is discharged to the conditioned air through the indoor coils which act as condensers during the heating mode of operation. The closed liquid circulating loop interconnects the heat pump chiller, the waste heat recovery coil and a heat storage means and may also be connected to a supplemental heat source and a solar heat collector. It is also contemplated that one or more remote water source heat pumps may be connected into the closed liquid circulating loop for heating and cooling remotely located spaces.

Power module with isolated substrates cooled by integral heat-energy-removal means

Abstract: The evaporating area of a heat pipe or thermosiphon evaporator is used as the thermal sink for one face of an electrically isolated substrate upon the opposite face of which are mounted and interconnected one or more power semiconductors and other components requiring cooling. Both sides of semiconductor devices mounted on the isolating substrate may be cooled while allowing each of a plurality of different combinations of electrical devices and/or interconnections to be achieved.

Heat pipe panel and method of fabrication

Abstract: A method for making a heat pipe panel comprising the steps of forming parallel furrows in a sheet metal plate, covering the sheet metal plate with another plate, bonding the plate together around the edges and between the furrows, to form parallel cavities between the plates, charging the cavities with working fluid and sealing the cavities to form individual heat pipes in the panel. The furrows may be filled with wicking material, and capillary grooves may be cut in the furrows before bonding the plates together. The cover plate also may have furrows formed therein. A header furrow may be provided for the fluid charging operations.

Thermal control canister

Abstract: A heat dissipating instrument package of a spacecraft, located in a canister having walls in heat transfer relationship with the package, is maintained at a substantially constant temperature. Fixed conductance heat pipes on the canister walls are connected to variable conductance heat pipes, mounted on a radiator structure separated from the canister walls by a thermal blanket. The effective radiating area of the radiator structure is controlled by the variable conductance heat pipes in response to a comparison of a sensed temperature of the instrument package or the canister wall with a seat point value. The comparison controls a heater in a gas reservoir containing a non-condensable gas of the variable conductance heat pipe. To enable the set point to be varied over a relatively wide range, such a 0°-30° C., a thermal radiation shield for the gas reservoir prevents radiant energy from the exterior environment and thermal energy reflected from the spacecraft from overheating the non-condensable gas. In one embodiment, variable conductance heat pipe headers are provided between the canister and radiators, with isothermalizer feeder pipes on the radiators and canister walls; in further embodiments, variable conductance heat pipe feeder pipes are coupled directly between the canister walls and one or more radiators.

Isothermal process solar collector panel

Abstract: An isothermal process solar collector panel is disclosed. The panel includes a collector plate for absorbing radiant heat; and a plurality of isothermal process heat pipes in an array over a surface of the collector plate. Each heat pipe is closed at both ends and contains thermodynamic working fluid for transferring heat energy from the collector plate to a second fluid flowing through a manifold pipe for conducting the heat energy from the collector panel. The manifold pipe is coupled to the heat pipes. One end of each heat pipe is coupled to the collector plate and has an evaporator section wherein heat energy is transferred from the collector plate to the thermodynamic working fluid; and the other end of each heat pipe is positioned within the manifold pipe and has a condenser section wherein heat energy is transferred from the thermodynamic working fluid to the second fluid flowing through the manifold pipe.

Method for reducing thermal degradation of a heat exchange fluid

Abstract: Heat is transferred from a hot reservoir to an intermittent user such as a domestic appliance through an intermediate heat exchanger. Heat storing material maintains a substantially constant temperature at its phase transition point. When the intermittent user is operating, a heat exchange fluid such as NaK transfers heat from the heat storing material to a thermally degradable organic thermal exchange fluid through the intermediate heat exchanger to the intermittent user at substantially the temperature of the heat storing material. When the intermittent user is not operating, circulation of the fluids stops which allows the thermal exchange fluid to cool thereby reducing its thermal degradation. The heat storing material is selected for a high latent heat of phase transition, the heat exchange fluid is selected for thermal stability, and the thermal exchange fluid is selected for intermittent user needs such as mobility in a liquid phase at hot and cold temperatures.

Heat pipe cooling for semiconductor device packaging system

Abstract: A system for cooling high density integrated circuits for computer systems comprising a cooling frame having a plurality of the heat pipes spanning the space within the frame to which sub-islands are attached to form an island. Each sub-island comprises a printed circuit board on which are mounted connectors for mounting the integrated circuit package and printed circuit board heat sinks having posts which cooperate with hold down pressure clamps for clamping the integrated circuit packages into the connectors and to clamp the heat sink plates of the integrated circuit packages to the printed circuit board heat sinks. These posts also aid in clamping the sub-islands together by cooperating a heat pipe hold down clamp by which each sub-island is clamped to the frame and to the heat pipes both mechanically and thermally to maximize the heat transfer between the integrated circuit packages and the heat pipes. The condenser end of the heat pipes extends into a plenum chamber through which air is circulated so that the heat generated by the integrated circuit packages ultimately dissipated in the ambient air. Utilization of heat pipes maintains the integrated circuit packages at a uniformly low temperature and in the preferred embodiment, each sub-island is modular and can be connected or disconnected from the frame as a unit for testing, repairing and/or replacement without disconnecting or dismantling any other sub-island or the island can be operated with less than full complement of sub-islands.

Experimental Evaluation of a Cylindrical Parabolic Solar Collector

Abstract: Results are presented for a series of solar collector experiments in which the incident solar flux was concentrated by a single-axis tracking parabolic trough mirror. The concentrated solar flux was directed onto an absorber tube whose axis coincided with the focal axis of the concentrator. The performance of the collector was evaluated using three different absorbers; a black painted tube designed to operate near ambient temperature, a heat pipe which had a selective solar absorber coating applied to its surface, and a heat pipe which had its surface coated with a nonselective black paint. The peak efficiency for the collector in the absence of heat losses is approximately 62 percent when the incoming solar energy is normal to the collector aperature. The heat losses which occurred at elevated temperatures (300degreeC) decreased the peak efficiencies to 50 and 30 percent, respectively, for the selectively coated and black painted tubes. The experimental results establish the technical feasibility of using parabolic trough collectors for applications requiring thermal energy at temperatures up to 300degreeC.

Transducer for mechanical measured variables, especially a pressure transducer

Abstract: A transducer for mechanical measured variables, especially a pressure transducer, having a heat pipe system within the housing, the heat pipe system is connected on one side to the thermally high stressed parts of the transducer, and on the other side to parts not exposed to heat or cold. The sensor element of the transducer is cooled through heat transport by means of an alternatively vaporizing and condensating working fluid within the heat pipe system.

Advanced cryogenic multi-staged radiator system

Abstract: A passive cooling device especially suitable for application where unattended high performance is required for long periods, such as with space satellite sensors, optics and electronic systems, contains multiple stages of heat radiators insulated from each other and from the supporting structure, with heat pipes thermally attached to some or all of the stages of the radiators to transport heat from the heat producing sources. The multi-stage radiator system utilizes intermediate radiator stages to intercept heat loads conducted through the insulation and supports in order to reduce such conductive loads on the outermost stage and to permit that stage to reject substantial heat loads at extremely low temperatures. These intermediate stages can also provide efficient thermal rejection at the different temperature levels of various elements to be cooled. Heat pipes of various characteristics such as the variable conductance and diode types can be used individually or in thermal combination to suit the needs and constraints of the space systems applications.

Pneumatically controlled wide heat load space radiator

Abstract: A three way valve selectively charges or discharges gas under pressure within the annular gaps between a series of transversely extending longitudinally spaced radiator tubes fixed to a radiator panel to control waste heat rejection and coaxial inner tubes which may comprise heat pipes or turns of a sinuous coolant flow tube for spacecraft, earth satellites and the like to thermal couple and decouple the heat pipe or coolant flow tube to the space radiator.

Turbine stator aerofoil blades for gas turbine engines

Abstract: A stator aerofoil blade for a gas turbine engine is manufactured in the form of a heat pipe so that during engine operation, the blade remains substantially isothermal. Localized thermal gradients within the blade are minimized thereby reducing the possibility of blade distortion or cracking. A shroud ring for a gas turbine engine is manufactured in the form of a heat pipe so that during engine operation, the ring remains substantially isothermal. Localized thermal gradients within the ring are minimized, thereby reducing the possibility of ring distortion occurring.

Transistor cooling by heat pipes

Abstract: A micro-electronic package which is capable of operating with power densities extending at least to 10 kilowatts per square centimeter comprises a sealed enclosure coupled to an external heat sink and electronic devices and circuitry within the enclosure. Electrical leads extend from the electronic devices and circuitry to the outside of the enclosure to couple the devices and circuitry into a larger electrical function. A dielectric powder is adhered as a complete and conformal coating substantially to all interior surfaces of the enclosure and to all exposed surfaces of the electronic devices and circuitry, and functions as a heat pipe wick. A dielectric working fluid within the enclosure, therefore, can intimately contact all the interior and exposed surfaces to minimize the occurrence of local hot spots on the electronic devices and circuitry and to maximize heat transfer therefrom to the external heat sink.

Heat pipe reactors for space power applications

Abstract: 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 kWe and operate in the temperature range 1200-1700 K. The reactors are fast, compact, heat-pipe cooled, high-temperature nuclear reactors fueled with fully enriched refractory fuels, UC-ZrC or UO2. Each fuel element is cooled by an axially located molybdenum heat pipe containing either sodium or lithium vapor. Virtues of the reactor designs are the avoidance of single-point failure mechanisms, the relatively high operating temperature, and the expected long lifetimes of the fuel element components.

Multiple heat pipe heat exchanger and method for making

Abstract: A heat pipe heat exchanger has a plurality of heat pipes which are interconnected so as to permit fluid communication between the pipes at least during charging so that the heat pipes may be simultaneously filled with heat transfer fluid.

Molten core catcher and containment heat removal system

Abstract: An apparatus for cooling molten material resulting from a nuclear reactor core meltdown is disclosed. The apparatus includes a basin positioned under the reactor which is protected against excessive heat by a star-like array of heat pipes whose evaporator sections are disposed above the pan and whose condenser sections are disposed in a heat sink exterior to the containment building of the reactor. Additionally, the vertical walls of the reactor vessel chamber are similarly protected by an array of heat pipes similarly arranged and provided to intercept the radient energy of the molten core material.

Thermal energy transformer

Abstract: For use in combination with a heat engine, a thermal energy transformer comprising a flux receiver having a first wall defining therein a radiation absorption cavity for converting solar flux to thermal energy characterized by a first wall defining a radiation absorption cavity having a solar flux entry aperture, and a second wall defining an energy transfer wall for the heat engine, and a heat pipe chamber interposed between the first and second walls having a working fluid disposed within the chamber and a wick lining the chamber for conducting the working fluid from the second wall to the first wall, whereby thermal energy is transferred from the radiation absorption cavity to the heat engine.

All climate heat exchanger unit with adjustable temperature and defrost control

Abstract: A plurality of parallel heat pipes extends between supply and exhaust ducts leading to and from an industrial or habitable enclosure. The heat pipes are mounted on, but at a fixed angular offset from, an axis about which they can be angularly rotated within the exhaust and supply ducts. Their mounting is also at an angular inclination to gravitational force to assure unidirectional operation. In this arrangement, the heat input is into the lower side of the heat pipes for proper operation. For two-season operation, rotation of the heat pipes by 180° ensures that the lower side of the heat pipes will always be in the warmer duct, whether exhaust or supply. Temperature control of incoming air is obtained by slight angular rotation of the heat pipes so that a part of each air stream in the exhaust and supply ducts bypasses the heat pipes. Defrost control is also obtained by a similar slight angular rotation of the heat exchanger, although a complete 180° turn is possible; however, with the unidirectional nature of the unit, after defrosting, the unit must be turned back 180° to its original position. Complete bypass is obtained by a 90° turn.

Heat pipe roller

Abstract: A heat pipe roller comprising an inner pipe, an outer pipe, and a chamber formed by the inner pipe and the outer pipe, containing a heating medium, wherein the inner pipe and the outer pipe are sealed above one portion of each end of the heat pipe roller.

Fusible heat sink for a cryogenic refrigerator

Abstract: A fusible heat sink for a cryogenic refrigerator used to provide cooling for a detector in the guidance system of a missile. The cryogenic refrigerator has a cold cylinder in contact with the detector and a hot cylinder. The hot cylinder and cold cylinder are connected to a crankcase housing. A heat pipe is connected between the crankcase and the missile skin for providing primary cooling for the crankcase housing. The fusible heat sink is connected to the crankcase with the crankcase forming part of the wall of the heat sink housing. A fusible material is located within the housing. The inside surface of the heat sink housing is coated with nickel and silver to increase the heat transfer between the crankcase and the heat sink.