Showing papers on "Heat pipe published in 2000"

Cooled, non-sticking electrosurgical devices

Abstract: An electrosurgical device has an electrode and a heat pipe to conduct heat from the electrodes where substantially all heat conducted from the electrode through the heat pipe is dissipated along the length of the heat pipe. The heat pipe can have a thermal time constant less than 60 seconds and preferably less than 30 seconds.

Apparatus for dense chip packaging using heat pipes and thermoelectric coolers

Abstract: An apparatus for dense chip packaging using heat pipes and thermoelectric coolers is provided The apparatus includes an evaporator region, a condenser region, and a capillary region The evaporator region includes one or more hot point elements used to transfer heat from a heat source to a transport fluid The transport fluid changes state to a vapor when heat is applied to the transport fluid The vapor travels to the condenser region via vapor channels and is condensed to a fluid once again by transferring heat from the vapor to a heat sink The condensed fluid is then returned to the evaporator region by way of capillary forces and capillaries formed in a capillary structure The capillaries formed in the capillary structure have a tree-like or fractal geometry The apparatus may further include a flexible region that allows the apparatus to be bent around corners and edges

Environmental system for rugged disk drive

Abstract: An arrangement for supplementing passive heat transfer from a hard disk drive housing to a surrounding environmental housing includes active heat transfer devices and an arrangement biasing the disk drive housing into heat conducting contact with the environmental housing The environmental housing includes a heat conducting outer shell and an internal heat conducting plate spaced from the shell, with the active heat transfer devices positioned in the space In one embodiment, lifting devices having relatively moveable wedge members are actuatable to lift the disk drive housing into firm contact with the heat conducting plate In another embodiment, the hard disk drive is moved into heat conducting contact by the cooperation of pins on the disk drive housing and inclined surfaces in the environmental housing, along with wedge members on a door of the environmental housing The active heat transfer devices can be Peltier effect devices or heat pipes

Forced Convection Heat Transfer to Phase Change Material Slurries in Circular Ducts

Abstract: Conclusions Expressions for the analytical temperature distribution and efŽ ciency of a heat pipe Ž n were derived and compared with experimental data. Two heat pipe Ž n cases were studied,  ush mounted and inserted into the object. The derived expressions are useful as a design tool. They allow the designer to compare heat pipe Ž ns to standard Ž ns before doing a detailed heat pipe design. Further researchcould focus on variations in heat pipe design and geometry.Thesecouldincludenonconstantpropertiesandboundary conditions.For this work, the wall cross-sectionalarea, the internal convectioncoefŽ cient, and the external convectioncoefŽ cient were assumed constant. The impact of these assumptions on accuracy should be investigated. It would also be interesting to extend the analysis to Ž ns in radiation environments.

Integrated vapor chamber heat sink and spreader and an embedded direct heat pipe attachment

Abstract: Two types of thermal management devices for efficiently dissipating heat generated by high performance electronic devices, such as microprocessors for desktop and server computers producing a power of near 200 Watts and high power electronic devices that are small and thin, such as those used in telephones, radios, laptop computers, and handheld devices. An integrated heat sink and spreader for cooling an item has a vapor chamber heat sink with a thinner first wall and a thicker second wall. The thicker second wall is engageable with the item in efficient heat transferring relationship. A plurality of heat-radiating fins are attached to the thinner first wall. An embedded direct heat pipe attachment includes a heat pipe embedded in a spreader plate that is in direct heat transferring contact with an item through a thin, uniform layer of thermal interface material.

Heat pipe heat sink for cooling a laser diode

Abstract: A heat sink module consistent with the present invention includes a heat pipe for efficient heat transfer heat away from a semiconductor pump laser. The heat pipe heat sink occupies less space than a conventional heat sink, and the condenser portion of the heat pipe heat sink can be easily manufactured using an extrusion process.

Image forming device

Abstract: PROBLEM TO BE SOLVED: To provide a high-quality image by mounting a cooling means capable of cooling a surface roughing means as necessary, so as to prevent a transfer material from being wrapped around a roller or the delivered transfer materials from being made to adhere to each other. SOLUTION: A fan 46d, disposed near a radiation fin 46c, is activated to cool hydraulic fluid in a heat pipe through the fin 46c. A section facing the roller 44 of the heat pipe can be connected to or released from the roller 44 as necessary. A thermistor 48 is disposed on the roller 44 so as to detect the surface of the roller 44 and drive and stop a fan 46d based on its indication. The heat of the roller 44 is transferred to an extending part 46b and the fin 46c effectively by vaporizing the hydraulic fluid of the heat pipe 46 and cooled by the fan 46d. The surface temperature should be kept constant to keep the glossiness of a fixed image properly.

Flexible heat pipe

Abstract: The invention is a very flexible heat pipe which is constructed of multiple layers of material laminated into the final structure. The center of the symmetrical structure is a coarse screen which creates a vapor space. The layers on either side of the screen are copper felt pads, and the outer casing is two layers of metal foil and a layer of polypropylene. The heat pipe constructed in this manner is so a flexible that when one outside surface is covered with adhesive, the heat pipe can essentially be used as tape or a stick-on heat transfer surface which conforms to a body being cooled.

Top mounted cooling device using heat pipes

Abstract: The present invention provides an integrated cooling device employing heat pipes for cooling an electronic component and a method of manufacturing the same. In one embodiment, the integrated cooling device includes a plate couplable to and supportable by the electronic component. The plate has at least one channel therein that presents an enhanced surface area. The cooling device further includes a sealed heat pipe having a heat-receiving portion fitted within the channel such that the enhanced surface area in contact with the heat pipe experiences an increased thermal communication between the plate and the heat pipe. The heat pipe also has a heat-removing portion that is distal from the heat receiving portion. Inside the heat pipe, a fluid, initially located in the heat-receiving portion of the heat pipe as a liquid, receives heat and evaporates to form a vapor that travels to the heat-removing portion. In the heat-removing portion of the heat pipe, the vapor condenses and cycles back o the heat-receiving portion.

Heat dissipating chassis member

Abstract: The invention provides a chassis member, which may be made of a cast material such as magnesium, aluminum, or plastic, for mechanically supporting a heat producing electronic device in which the chassis member has a base and a cavity integral to the chassis member. In a preferred embodiment, the cavity is in the form of a channel that is created by boring. The channel may be evacuated and has an evaporator section, a condenser section, and a working fluid confined therein by a seal. The channel receives heat from an electronic device in an evaporator section of the channel and dissipates heat from the condenser section of the channel. Different types of wicks may be employed. In one embodiment, a completely fabricated heat pipe is inserted into the integrated channel. In other embodiments, a cavity in the form of a heat dissipating channel matrix, serpentine shape, flat shape, or in other forms or shapes are provided.

Multifunctional capillary system for loop heat pipe statement of government interest

Abstract: A Multifunctional Capillary System is located within and between a single compensation chamber (CC) and the evaporator of a loop heat pipe. It provides: vapor-liquid interface control for all gravity states from the micro-gravity condition of space (near 0-g) through the earth's gravitational condition (1-g), with liquid supply to the evaporator via wicking from the CC in micro-gravity, and for all orientations (tilts) of the CC-evaporator assembly in earth gravity. As a single compensation chamber is used, dual compensation chamber penalties of weight and wide-temperature-variation are avoided. The system has combined, parallel wicking structure, paths, and joints for micro-gravity and 1-g liquid acquisition. The wick system is comprised of an axial-groove, evaporator-core secondary wick—concentric, contiguous, and in intimate contact with the primary evaporator wick. This secondary wick mates to a porous vane assembly in the CC. The design provides wicking continuity at this and at other joints within the system. In both the micro-gravity environment and under worst case 1-g orientation (CC below evaporator) the design can supply liquid to the primary wick under a wide range of temperature and power for steady state, startup, and transient conditions.

Advanced cooling system using miniature heat pipes in mobile PC

Abstract: This paper describes various cooling solutions using heat pipes for cooling a notebook PC. These are: 1) heat pipe with heat spreader plate; 2) hybrid system-i.e., heat pipe with heat sink and fan; and 3) hinged heat pipe system. For heat input of less than 12 W, the thermal resistance measured between the surface of the CPU to ambient was obtained as follows: greater than 8/spl deg/C/W for system 1) and 4-6/spl deg/C/W for systems 2) and 3). For the CPU having specification of surface temperature of 95/spl deg/C and 40/spl deg/C ambient, then system 1) can be dissipated by about 6 W, whereas systems 2) and 3) can handle 13 W. Experimental results of these three systems are included and discussed in this paper.

Pavement snow melting

Abstract: The design of pavement snow melting systems is presented based on criteria established by ASHRAE. The heating requirements depends on rate of snow fall, air temperature, relative humidity and wind velocity. Piping materials are either metal or plastic, however, due to corrosion problems, cross-linked polyethylene pipe is now generally used instead of iron. Geothermal energy is supplied to systems through the use of heat pipes, directly from circulating pipes, through a heat exchanger or by allowing water to flow directly over the pavement. Examples of geothermal and other systems in New Jersey, Wyoming, Virginia, Japan, Argentina, Canada, Switzerland and Oregon are presented.

On transient heat losses from buried district heating pipes

Abstract: The theory of steady-state heat loss determination from buried heating pipes has been reviewed as well as previous approaches to treat transient heat losses in the case of constant water temperatures. A new method has been developed to find an undisturbed ground temperature by which the transient heat loss can be calculated by the use of the steady-state heat loss equations. By numerical simulations, as well as by experiment, the position of this undisturbed ground temperature has been found. The position of this ground temperature is closer to the ground surface in the case of uninsulated pipes—or pipes with the insulation in poor condition—than in the case of insulated pipes. For pre-insulated pipes the position corresponds approximately to the top of the pipe casing. Copyright © 2000 John Wiley & Sons, Ltd.

Computer assembly for cooling high powered microprocessors

Abstract: An improved computer assembly is disclosed, which includes a chassis that has at least one drive bay, the drive bay having an opening. A heat sink is positioned within the drive bay and a thermally conductive component is coupled to the heat sink and to a processor assembly. In a preferred embodiment, a heat pipe couples the thermally conductive component to the heat sink.

Electrical circuit board and method for making the same

Abstract: A multi-layer circuit board with heat pipes and a method for forming a multi-layer circuit board with heat pipes. The method includes forming channels in a first and second pre-circuit assembly and attaching the first pre-circuit assembly to the second pre-circuit assembly such that the channels cooperatively form a heat pipe.

Dual-enclosure optoelectronic packages

Abstract: The invention is a package (100) housing optical components and electronic components in separate enclosures. The first enclosure (142/130/170/175) includes optical components (165/157/180), optical alignment means (160), and a heat pipe (155) that dissipates heat generated by the optical components therein. The first and second enclosures are hermetically sealed. The second enclosure (130/112/110/114) includes electronic components (120), a Peltier-type cooling device (125), and/or other heat dissipating devices. The first and second enclosures are each hermetically sealed. The first enclosure can be mounted above the second enclosure or vice versa in alternative embodiments of the invention. In another embodiment, a heat sink (105) is also mounted to the top of the dual-enclosure package.

End-effector with integrated cooling mechanism

Abstract: An end-effector (200, 300, 400) with integrated cooling features comprises heat transferring mechanisms that transfer heat energy away from the end-effector. The end-effector advantageously minimizes the cooling overhead of a processed substrate as it is transported from a process module to a low-cost storage cassette. The reduced cooling overhead of the processed substrate, as a consequence, improves substrate throughput. In the preferred embodiments, the heat transferring mechanisms include a high surface area heat sink (110) connecting the substrate-supporting paddle (115) with a robot arm. Cooling fins (105) can enhance surface area and thus enhance heat dissipation from the heat sink. Cooling channels can extend through end-effector. In one embodiment, channels (305) extend through both the paddle (315) and handle portion (310), and containing circulating fluid for carrying heat beyond the end-effector (300). In another embodiment, channels (405) extend only through the heat sink (410), containing circulating fluid for carrying heat beyond the end-effector (400). In still another embodiment, channels (505) comprise heat pipes enclosing a phase changing material.

High heat flux heat pipe mechanism for cooling of electronics

Abstract: This paper discusses an advanced heat pipe mechanism that has the potential of achieving heat flux capabilities over 250 W/cm/sup 2/. The mechanism utilizes thermally driven pulsating two-phase flow to achieve high heat flux capability and heat transfer coefficient. A simplified hydrodynamic model was developed to guide the proof-of-concept heat pipe design. A more detailed numerical model was also developed and is solved to predict the heat pipe's thermal performance. Test results of proof-of-concept heat pipes verified the heat flux capability of the advanced mechanism and the accuracy of the simplified model. Pulsating heat pipes are feasible approaches to removing increasing heat dissipation densities in electronic equipment.

High thermal conductivity heat transfer pad

Abstract: A thermal pad for use in facilitating heat flow between a heat source surface and a heat sink surface includes a carbon fiber fabric that is impregnated with a thermal substance.

Plate type heat pipe

Abstract: A sealed plate type metallic heat pipe is disclosed having multiple independent through holes which run through the inside of the heat pipe. All of the through holes are connected in fluid communication at each end. A working fluid is disposed in the through holes and a wire or a wire mesh is disposed in at least one of the through holes.

Heat dissipating conduit

Abstract: A heat dissipating conduit of loop cross section and housing a heat dissipating fin plate. The heat dissipating fin plate is formed by continuously folding a thin plate and has folding pitch adapted with size of the heat dissipating conduit, whereby heat from a thermal source can be transmitted through arbitrary point on the heat dissipating conduit. The heat dissipating conduit can be connected pipe, heat pipe, connected heat pipe, flexible planar heat pipe or bubble-type circulation pipe. The contact area is increased and the heat dissipating effect is enhanced. The noise is reduced and the structure is more compact.