Showing papers on "Heat pipe published in 1983"

Waste heat boiler

Abstract: A system for recovering waste heat from a stream of heated gas is disclosed. The system includes a convection heat transfer chamber, a boiler tank, and a plurality of heat pipes thermally interconnecting the convection heat transfer chamber with the boiler tank. Each of the heat pipes includes an evaporator section which is disposed in heat transfer relation with a stream of heated gas flowing through the convection heat transfer chamber, and a condenser section disposed in heat transfer relation with a volume of water disposed within the boiler tank. The evaporator sections and condenser sections are totally enclosed within the convection heat transfer chamber and boiler tank, respectively, and are connected in closed cycle fluid communication with each other. The heat pipes contain a working fluid which is characterized by a thermodynamic cycle in which the working fluid is vaporized in the evaporator section and flows to the condenser section where it is condensed to the liquid phase and returns in a closed cycle to the evaporator section, thereby transferring heat energy from the heated gas stream in the convection heat transfer chamber to the volume of water contained in the boiler tank. In a regenerative arrangement, exhaust gas discharged from the convection heat transfer chamber is recycled to the input of the convection heat transfer chamber to provide high mass flow at low velocity for optimum efficiency. In another arrangement, superheated steam is provided by a pair of heat pipe boilers whose convection heat transfer chambers are connected in series, with the evaporator of the steam generating unit being located downstream of the superheat unit and the input of the superheat unit being the steam output of the steam generating unit.

Passive integral solar heat collector system

Abstract: The present invention relates to an improved apparatus for collecting, absorbing, transferring, and storing solar heat energy, economically and passively, without pumps or electric power. The apparatus comprises a solar collector with a flat finned heat pipe absorber and an attached integral insulated storage tank with a double wall heat exchanger. The absorber, made of one or more slightly tilted gravity assisted heat pipes with flat absorber fins, absorbs and transfers solar heat by evaporation, vapor transport, and condensation to the slightly elevated heat storage tank. The one or more heat pipes turn on when the sun is shining and turn off automatically when the sun is not shining.

Heat pipe cooling module for high power circuit boards.

Abstract: A heat pipe cooling module assembly (20) for cooling electronic components (28) includes a plurality of heat pipe modules (22) comprising condenser and evaporator sections (24, 26) and working fluid therein. In a preferred embodiment, each evaporator section comprises a sandwich construction of a pair of flat outer plates (34), a pair of wick pads (36) and a separator plate (38) comprising channels extending from the evaporator section into the condenser section.

Heat transfer characteristics of in‐ground heat exchangers

Abstract: Most in-ground heat storage installations use a system of horizontal or vertical plastic pipes to carry heat exchanger fluid. In designing these systems it is generally assumed that the thermal effects of the plastic pipe can be neglected. This paper reports a laboratory study of the pattern of heat flow around fluid-carrying plastic pipe buried in clay soil. Heat flow measurements as well as estimated contact resistances are presented for a number of configurations. In addition, numerical model computations are given for steady-state, transient and cyclic behaviour of several configurations, and it is shown that substantially reduced heat flows are obtained when plastic pipe is used.

Pump type dispenser for heat softenable food products

Abstract: A pump-type dispenser for heat softenable food products including a product receptacle and a heater for heating the product in the receptacle to a predetermined product softening temperature range at which the product is heat softened to a pumpable condition. A product pump extends downwardly into the receptacle to receive product therefrom and has a spout disposed externally of the receptacle. A closed heat pipe containing a vaporizable heat transfer fluid has its upper condensation zone in heat exchange relation with the spout and its lower evaporation zone arranged to receive heat from the heater.

Temperature stabilization system

Abstract: A system for stabilizing the temperature of a radiation detector assembly includes a heat pipe device which generally encloses the radiation detector assembly and absorbs the ambient heat of the radiation detector assembly. A temperature sensor senses the ambient temperature in the heat pipe device and provides a constant current signal representative of the sensed temperature. A heating cooling device controls the ambient temperature within the heat pipe device in accordance with a constant current control signal. Apparatus located at a substantial distance from the radiation detector assembly and connected to the temperature sensor and the heating cooling device provides the constant current control signal to the heating cooling device in accordance with the constant current temperature signal from the temperature sensor so as to control the temperature of the radiation detector assembly.

Heat pipe manifold system

Abstract: A hot manifold system for use in the injection molding of plastics is disclosed wherein runner channel heating is accomplished by heat pipes disposed within the manifold adjacent to the runner channels contained therein. The manifold system is an elongated structure having a heat receiving portion and a runner containing portion such that heat input may be applied to the heat receiving portion at an accessible location relative to the mold and conveyed to the remainder of the manifold for uniform heating thereof by the heat pipes.

Geothermal energy conversion system

Abstract: Apparatus and a method for using terrestrial heat to increase the temperature of a liquid, such as water. A circulation pipe buried in the earth in a region of high subterranean heat allows the liquid to move in heat exchange relationship to the subterranean heat. The liquid is pumped from a tank adjacent to the surface of the earth and through the pipe back to the tank. The heated water in the tank can be removed from the tank and caused to flow through a heat exchanger also adjacent to the surface of the earth. Then, the water is returned to the tank for re-use and reheating.

Development of thermal energy storage technology using metal hydrides

Abstract: The rate of heat transfer is important in heat storage technology using metal hydrides because the rate of hydrogen transfer depends on the rate of heat transfer. A new metal hydride container with heat pipes which were able to transfer heat rapidly was constructed and was used to operate the heat storage system with a hydrogen flow of 1.51 min−1 between 3.5 kg beds of CaNi5 and LaNi5. The metal hydride beds were located inside cylindrical heat pipes 66 cm long with an inside diameter of 4 cm.

Apparatus for growing crystals

Abstract: An improved apparatus and method for growing crystals from a melt employing a heat pipe, consisting of one or more sections, each section serving to control temperature and thermal gradients in the crystal as it forms inside the pipe.

Heat pipe assembly

Abstract: Means for accurately controlling the transfer of heat to or from a device includes a heat pipe having a condenser end and an evaporator end. A helical screw thread is provided on the exterior surface of the heat pipe so that a portion of the heat pipe may be removably insertable via the threading into a threaded aperture in a desired section of the device. Alternatively, a connecting member, in which a portion of the heat pipe is fixed, may be selectively secured to the desired section of the device. At least one heat sink fin which is selectively securable on the heat pipe via the threading may also be provided.

Multiple heat range spark plug

Abstract: A spark plug having a heat pipe located between the insulating core and the shell in the skirt portion thereof to vary the heat range automatically in response to the operating conditions of the engine in which it is fitted. The heat pipe is charged with a non-condensible gas and a working medium that undergoes a phase change at a predetermined design temperature to transport heat by means of an evaporation-condensation cycle from the firing end of the spark plug to prevent the overheating thereof. Below the design temperature, the heat pipe is thermally non-conducting such that the firing end of the spark plug is allowed to reach a temperature that will burn off combustion deposits that cause misfiring. In one embodiment, the heat pipe is fabricated as a separate integral annular element which is installed in the skirt of the spark plug during the manufacture thereof. In another embodiment, the separate integral heat pipe element has a thin-wall construction in which a resilient wire-screening wicking system provides the required structural integrity and a thin-walled envelope acts as a containment system for the working medium. In further embodiments, the open end of the skirt of the spark plug itself is sealed off with an end wall such that a heat pipe is formed in the annular volume between the insulating core and the shell bore.

Anti-icing of gas turbine engine air intakes

Abstract: A turboshaft gas turbine engine 10 has an annular air intake 11 having a number of radially 23 extending stator vanes 20 located around a reduction gearbox 17. A number of heat pipes 22 extend through the vanes 20 to interconnect the interior of the reduction gearbox 17 with a heat sink 28 situated adjacent the upstream lip 23 of the intake 11. Heat from the hot oil mist within the gearbox is thus conducted to the heat sink 28 and serves to heat up the intake lip 23 to prevent the formation of ice thereon, while at the same time the oil mist is cooled.

Tube‐wall catalytic reactor cooled by an annular heat pipe

Abstract: Cooling a tube-wall reactor using an annular heat pipe (AHP) is more temperature-stable, more flexible and more productive than cooling by conventional means. Tube-wall reactors cooled by an annular heat pipe arrangement exhibit flatter temperature profiles and uniform redistribution of the imposed heat load. The combination of tube-wall reactor and annular heat pipe is subject to the usual capacity limitations of the heat pipe: sonic flow, boiling heat transfer, liquid entrainment, and capillary flow of the working fluid.

Finned-tube type heat exchanger

Abstract: PURPOSE:To improve the heat transfer rate and draining property of the heat exchanger by a structure wherein rugged strips are formed on a fin between each of heat pipes toward the direction of the steps of the heat pipes and erected pieces open with the same inclination and direction are also formed on both sides of the fin employed in the finned tube type heat exchanger used for an air conditioner and the like. CONSTITUTION:The rugged beads 4 are provided between the heat pipes 2 piercing the flat plate fins 1a toward the direction normal to the direction of air flow as indicated with the white arrow. A plurality of the erected slits 5-8 are provided on both sides of the rugged beads 4. The erected slits 5 and 6 are formed by being erected on both sides of the fin 1a so as to have the fixed inclination and direction and the erected slits 7 and 8 are formed by being erected alternately on either of both sides of the flat plate fin 1 so as to have the same inclination and direction as those of the erected slits 5 and 6 toward the surface of the flat plate fin 1. Owing to the structure as described above, the temperature boundary layers on the rugged beads 4 and the erected slits 5- 8 become thin and stimulate the disturbance in the flow passing over the beads 4 and the slits 5-8, resulting in improving the heat transmitting property. Furthermore, when the titled heat exchanger is used as an evaporator, the draining property of condensate is improved due to the capillarity of the rugged beads 4.

Heat piped piston

Abstract: A piston having an evaporation-condensation heat pipe to transfer heat between piston crown and piston skirts. The evaporation-condensation heat pipe is formed as a structure separate from the piston itself, and the two are joined together by a high conductivity adhesive-elastomer bond.

Solar energy collecting apparatus

Abstract: PURPOSE:To increase the accommodation efficiency of a capsule and at the same time provide the solar energy collecting apparatus usable for multi-purpose by a structure wherein lenses for collecting solar light energy and lenses for collecting solar heat energy are effectively assembled so as to be housed within the capsule. CONSTITUTION:Lenses 20 concentrate the solar rays in pointed focuses, at the locations of which light collecting parts 21 are arranged, while linear lenses 30 concentrate the solar rays in linear focuses, along the locations of which heat collecting parts 31 such as heat pipes or the like are arranged. The light energy collected by means of the light collecting parts 21 is conducted through optical conduction cables 22 in optical fiber pipes 23 and then, via said optical conductive pipes 23, transmitted to arbitrary desired location to be used for illumination and other application. On the other hand, the heat energy collected by means of heat collecting parts 31 is transmitted via heat transfer pipes 32 such as heat pipes or the like to a heat exchanger 33, at which the heat energy is used as various heat sources.

Testing and analysis of a heat-pipe solar collector

Abstract: We developed an integral heat pipe/evacuated-tube solar collector in which the inner receiver tubes form the evaporator sections of glass heat pipes. This paper describes both theoretical analyses and empirical tests, comparing the performance of the glass heat pipe solar collector with one of today's high efficiency evacuated tube solar collectors. The comparison demonstrates that the performance of the two collectors is effectively identical. The testing and analysis indicate that the glass wick-type glass heat pipe is an effective heat transfer system for evacuated-tube solar collectors.

Thermally isolated well instruments

Abstract: A well instrument is isolated from the high temperatures of a surrounding earth formation by enclosing the instrument within a heat insulative jacket structure, preferably a dewar having spaced walls with a vacuum therebetween, with a heat sink contained in the jacket above the instrument assembly, and with a heat pipe extending upwardly from the instrument assembly to the heat sink and containing a fluid which by evaporation at a lower point and condensation at a higher point will conduct heat upwardly from the instrument assembly to the heat sink but not downwardly therebetween. The heat pipe preferably projects upwardly beyond a top portion of the insulating jacket to the location of a convector element which is exposed to the temperature of fluid or air at the outside of the insulating jacket to transmit heat from within the jacket to its exterior but not in a reverse direction.

Solar heat collector

Abstract: PURPOSE:To prevent the interior of a heat radiating cylinder from being overheated by a method wherein the solar heat collector provided with the heat releasing cylinder connected with a heat pipe the, heat pipe is made to be of cntrollable type and is arranged in such a manner that the heating section thereof is connected to the outer periphery of the heat releasing cylinder while the cooling section thereof is kept away from the heat releasing cylinder. CONSTITUTION:The heat pipe 3 is provided within a light transmissive vacuum glass tube 1 with one end of the heat pipe projecting outside the glass tube and the outer end thereof connected to the heat releasing cylinder 10 enclosing a heat medium pipe 11. In the case of the heat collector of the above structure, a variable conductance type heat pipe in which an operation liquid and a non-condensable gas are sealed at the ambient temperature and under the atmospheric pressure is used as the controllable type heat pipe 18. In this case, the heating section 181 of the heat pipe 18 is connected to the outer periphery of the heat releasing cylinder 10 and the intermediate section of the pipe 18 is passed through a casing 9 to become continuous with the cooling section 181 having a heat radiating fin 182 on the outer periphery thereof. With the above structure, when the solar heat collector is burned dry, the operation liquid 13A within the heating section 181 is vaporized and transferred to the cooling section 183 to be cooled and condensed and the condensed operation liquid is dropped on the heating section 181 to thereby prevent the interior of the heat releasing cylinder from being overheated.

Heat transfer in evaporation and condensation zones in heat pipes with intensive heating of their ends

Abstract: An experimental study is made of heat transfer in the condensation zone and during boiling in the heating zone in heat pipes with intensively heated ends. Generalized relations are presented.

Nozzle cooled by heat pipe means

Abstract: A tubular member (40, 40') which has heat pipe cooling means (48, 48') cooperatively associated therewith and which is particularly suited for use in the manner of a nozzle for purposes of effecting the introduction of fuel, air, etc. into a substantially closed area 12 in which combustion takes place. The subject tubular member, i.e., nozzle, (40, 40') is suitably supported relative to the aforesaid combustion area (12) such that one end (30, 30') of the former (40, 40') communicates with the interior of the combustion area (12) and the other end (32, 32') thereof communicates with the exterior of the combustion area (12). Heat pipe means (48, 48') having an evaporator, i.e., hot, end and a condenser, i.e., cold, end is suitably supported in surrounding relation to the tubular member (40, 40') so as to be operative to effect a cooling of the latter (40, 40'). Within the heat pipe means (48, 48'), there is established a flow path along which a continuous flow of fluid occurs. In accord with this flow path, fluid in the form of a liquid flows through capillary action from the condenser end to the evaporator end of the heat pipe means (48, 48'). At the evaporator end of the heat pipe means (48, 48'), the liquid absorbs sufficient heat from the combustion area (12) that it vaporizes. As a vapor, the fluid then flows back from the evaporator end to the condenser end of the heat pipe means (48, 48'), where it is cooled and condenses. Thereafter, as a liquid the fluid once again commences its travel along the flow path provided therefor within the heat pipe means (48, 48').

Heat pipes with shrouded fins and fan

Abstract: A soil freezing apparatus includes a vertically oriented sealed heat pipe containing refrigerant and having a soil-embedded lower end and an upper end with radial heat exchange fins for conducting heat from the pipe to the atmosphere. A cylindrical tubular open-ended shroud means is fitted over the heat exchange fins for enclosing same and an electric motor driven fan is operable for effecting the upward flow of ambient air through the shroud means in contact with the heat exchange fins for increasing the heat flow rate from the fins to the atmosphere.

Thermal Management System Technology Development for Space Station Applications

Abstract: A short discussion of the history to date of the NASA thermal management system technology development program is presented, and the current status of several ongoing studies and hardware demonstration tasks is reported. One element of technology that is required for long-life, high-power orbital platforms/stations that is being developed is heat rejection and a space-constructable radiator system. Aspects of this project include high-efficiency fin concepts, a heat pipe quick-disconnect device, high-capacity heat pipes, and an alternate interface heat exchanger design. In the area of heat acquisition and transport, developments in a pumped two-phase transport loop, a capillary pumped transport loop using the concept of thermal utility are reported. An example of a thermal management system concept is provided.

Specimens rotating device

Abstract: A specimens rotating device including a cooling source located in the central portion of a rotary plate, and a plurality of specimens arranged in the peripheral portion of the rotary plate in a manner to surround the cooling source A plurality of heat pipes are arranged between the cooling source and the specimens so that each heat pipe is secured at one end to the cooling source and at the other end to one of the specimens Each heat pipe has a working fluid sealed therein and its one end is exposed in a cooling fluid in a channel in the cooling source Upon rotation of the rotary plate, the specimens are rotated along with the rotary plate, and the working fluid in the heat pipes is shifted toward the specimens The working fluid absorbs heat from the specimens and evaporates into vapor which quickly returns to the cooling source due to the difference in vapor pressure to condense into condensate by releasing the latent heat of evaporation into the cooling source which constantly receives a fresh supply of cooling fluid, to enable the heat from the specimens to be effectively released to outside