816 results about "Natural convection" patented technology

This invention discloses heat dissipation devices for an LED lamp set with a plate-type heat spreader as the core unit. The plate-type heat spreader is either a flat-plate heat pipe or a metal plate embedded with heat pipes. The high-power LED lamps are thermally connected to the bottom surface of the heat spreader so that the heat generated by the LED lamps is absorbed by the evaporation region of the flat-plate heat pipe or the embedding heat pipes. The heat is spread by internal vapor motion of the working fluid toward different regions of the heat spreader. The top surface of the heat spreader is connected with a finned heat sink, where the heat is delivered to the ambient air. The hot air leaves by buoyancy through the openings on a lamp housing located above the finned heat sink. An alternative design is that the inner surface of the lamp housing is connected with the top surface of the plate-type heat spreader, with the heat dissipated out at the surface of the housing by natural convection.

If a forced convection is generated by a cooling fan, there is generated a problem that a natural convection is prevented and a cooling effect in a region of the natural convection is lowered. The invention provides a structure in which an air flow generated by a forced convection does not come into contact with an air flow generated by a natural convection, by setting a partition all between a forced convection path in which the air flows on the basis of a forced convection generated by a cooling fan, and a natural convection path in which the air flows on the basis of a natural convection. Further, the partition wall is not provided near an upper end so as to draw in the air flowing through the natural convection path to a side of the forced convection path, thereby promoting the natural convection of the natural convection path.

A heat-transfer device has a sealed vapor chamber with a phase-change fluid therein, and a thermoelectric cooling (TEC) element with a cooled side in thermal contact with the vapor chamber and a heated side in contact with heat-dissipation fins. The TEC element decreases the temperature of the vapor chamber and increases the temperature of the fins for improved efficiency. The vapor chamber is defined between concentrically positioned tubes, and a tunnel region is located within the inner tube. Additional TEC elements within the tunnel region further dissipate heat. In two-phase natural convection embodiments, TEC elements may further cool liquid returning to the heat source. Parallel heat dissipation paths may also be provided. In a two-phase forced convection embodiment, a TEC element may further cool liquid returning to the heat source, and additional TEC elements may be provided on the condenser. In some embodiments, active feedback controls the amount of energy transferred by a TEC element.

The invention discloses a combined LED lamp cup, which comprises a radiating component. A cavity is formed inside the radiating component; a plurality of longitudinally arranged radiating fins are uniformly distributed on the outer surface of the radiating component; a plastic shell is sleeved outside the radiating component; and a plurality of radiating holes are formed on the plastic shell. Due to the arrangement of the plastic shell outside the radiating component, a user is effectively prevented from being scratched by edges of the radiating fins, and the user is prevented from being scalded by the surfaces of the radiating fins when a lamp works; moreover, a plurality of air ducts are formed through the radiating holes to force air to enter the radiating channel upwards from the lower end of the lamp cup and flow out of the radiating holes. Therefore, high-efficiency convection heat dissipation is formed, and compared with that of the conventional natural convection heat dissipation mode of exposing the lamp cup, the radiating effect is improved.

A new and novel ozone generator with a dual dielectric barrier discharge design is disclosed where high-purity ozone is generated and whose concentration can be varied over a wide range. The simplified design of the ozone generator cell possesses a gas inlet and outlet connected to an annular, sealed dielectric gas envelope that supports both inner and outer electrodes that do not come into contact with the gas. The design eliminates the need for gaskets, o-rings or other methods applied to seal the ozone cell and reduces problems associated with potential interaction resulting from material compatability issues. The applied high voltage is provided by a simple self-resonating, push-pull oscillating circuit whose efficiency is optimized through application of an appropriate impedance matching device. The ozone is concentration is adjusted by varying the pulse width duty cycle of the applied voltage and gas flow rate. The design configuration of the ozone generating cell also eliminates the need for forced air or liquid cooling by natural convective air currents and conductive means.

A dual air cavity roof has a continuous upper cavity which is cooled by fans, while the lower cavity is generally sealed. Preferably the cavities are separated by a radiant barrier. The fans are preferably powered by one or more photovoltaic cells that are also disposed on the roof. The roof can be pre-cooled with cooler night air and fans only activated when necessary to remove heat from the solar load on the upper cavity. When it is desirable to remove heat, the fan speed is optimized in each zone of the roof to enhance the natural convective flow to the optimum level. A radiant barrier can also cover the roof substrate, which is optionally an existing roof that is in need of repair. The roof structure is preferably assembled in parallel modules using insulating support brackets that support the outer surface and the barrier that separates the upper and lower cavity.

The inventive device is embodied in the form of a chamber-oven for diffusing vapour and saturated hot air which circulate in a closed circuit by natural convection. Said device is embodied in the form of a domestic-use solar energy collecting device provided with a greenhouse whose surface is equal to 1 m² and produces from 50 to 100 litres/day of distilled water. The device comprises a distillation unit arranged between two furnaces (59′, 79′) in a temperature-controlled container (48′). Said distillation unit comprises 100 flat thin hollow plates having a surface of 20 dm² by face and an active volume of 200 dm³. The fine and tensioned walls (54) of said plates are provided with a hydrophilic coating (60′) and internal (56′) and inter-plate (58′) spaces. The lower chimney (59′) comprises a greenhouse (118′, 119′) whose bottom is embodied in the form of an impermeable black layer provided with a thin hydrophilic carpet on the rear part thereof. Saturated hot air at a temperature of 80° C. enters inside (56′) hollow plates from bellow and exits from the top at a temperature of 50° C. A high chimney (79′) is provided with a monoblock heat exchanger (84′) which is transversed by a non-potable water to be distilled which, afterwards is spread warm (40° C.) over the hydrophilic coating (60′). During passage through the heat exchanger (84) the air is cooled to 30° C. and moved down by gravity to the inter-plate spaces (58′) and exits therefrom at a temperature of 78° C. The distilled water condensed in the plates and by the heat exchanger is collected and removed. Brine is received in the bottom of the inter-plate space and distributed along the thin hydrophilic carpet of the bottom (122′) of the greenhouse. An air current passes along said hot carpet is heated and saturated and enters the plates. The brine liquor finally flows in an air-preheating tank (63′) which is emptied each morning. The greenhouse can be substituted by a heating tube transversed by a heating fluid or associated with another steam-jet tube. The more powerful chamber-ovens can produce at least 200 m³/day of distilled water for collective consumption. Said invention can be used for salt removal from seawater, co-generating electricity and potable water and for producing food concentrates.

A heat dissipating system includes: a heat-absorbing unit having at least one cavity body adapted to contact a heat source, and a working fluid received in the cavity body; a condenser to condense the working fluid; and a tubing unit connected fluidly to the condenser and the heat-absorbing unit. The working fluid flows through the tubing unit to circulate from the condenser to the heat-absorbing unit by gravity and from the heat-absorbing unit to the condenser by natural convection. The tubing unit forms a closed circulating loop with the heat-absorbing unit and the condenser.

The invention provides a method for testing content of unfrozen water in frozen earth. The method is mainly applied to the testing on the content of unfrozen water in natural frozen earth and artificial frozen earth. The method comprises the steps of firstly processing the tested soil sample obtained in place according to the specified specification; subsequently freezing the tested soil sample to the low-temperature range of -30 to -15 DEG C; subsequently heating and melting the tested soil sample by natural convection under the room temperature air condition of 20 to 35 DEG C; recording thechange of the central temperature of the sample with the time; establishing a calculation model reflecting the temperature change process of the frozen earth according to a Newton cooling law; analyzing the convection heat transmission coefficient between air and soil; determining phase change time and phase change temperature so as to further calculate the content of unfrozen water under the frozen state; and finally calculating the characteristic curve of unfrozen water content during the melting process according to the test results. The method is simple and feasible and the testing resultis exact and reliable.

A system and apparatus for regasifying liquefied natural gas (LNG) and other cryogenic liquids on a continuous basis utilizing improved atmospheric air vaporizer heat exchangers of the vertical single pass and parallel connected type. A multiplicity of such heat exchangers is positioned on a defined grid, such as to improve the natural convection of the ambient air heat source. An improved heat exchange system includes heat exchange elements within the heat exchangers comprised of hybrid externally finned elements, smooth interior stainless steel tubes thermally bonded within the externally finned elements, the tubes containing vortex generators. Flow distributors in the form of venturi shaped injectors are positioned at the inlet of each tube of the multiplicity of heat exchangers of the system.

The present invention features a non-peripherals-based processing control unit having an encasement module that is very small and durable compared to conventional computer encasement structures. The process control unit is capable of being incorporated into various devices and/or environments, of accepting applied and impact loads, of functioning as a load bearing structure, as well as being able to be processed coupled together with one or more processing control units to provide scaled processing power. The processing control unit of the present invention further features a unique method of cooling using natural convection, as well as utilizing known cooling means, such as liquid or thermoelectric cooling.

A traditional passive thermal management system can only be used effectively in a single orientation because it relies on the buoyancy of the heated air to create natural convection. A passive thermal management system is provided which includes means for transferring heat away from a heat source (10) in any orientation. The system comprises a heat pipe (14) which is thermally coupled to the heat source (10). The heat pipe (14) is capable of transferring heat away from the heat source (10), wherein this heat is transferred along the length of the heat pipe (14). Thermally coupled to the heat pipe (14) is a fin system (12), which provides a means for extraction of the heat from the heat pipe (14) and transfer of this heat to the environment thereby dissipating the heat generated at the heat source (10). The fin system (12) is configured to provide a desired level of heat transfer to the environment independent of the orientation of the thermal management system.

The extruded section forms a tunnel that is substantially rectangular and is provided with fins on at least one side of the rectangle. The fins allow air to flow outside the housing by natural convection in the extrusion directions. A side without fins serves as a base for fastening the housing and as a support for power electronic components of the power electronic device. The fins are machined transversely to the extrusion direction to form notches in the fins. The notches being aligned in succession to allow air to flow outside the housing by natural convection in the optimum direction.

The invention discloses a loop heat pipe condenser, consisting of an evaporation chamber, a heat pipe and a sealed hollow condensation cavity, wherein the condensation cavity and the evaporation chamber are both provided with a working fluid inlet and a working fluid outlet; the working fluid outlet of the evaporation chamber is communicated with the working fluid inlet of the condensation cavity; the working fluid outlet of the condensation cavity is communicated with the working fluid inlet of the evaporation chamber through another pipe; the surface of the condensation cavity is provided with a plurality of fins. The heat pipes of the prior loop heat pipe devices directly extend through the fins; therefore, the condensation effect is not good; especially in case of heat dissipation through natural convection, the cooling effect is very poor. On the basis of the prior loop heat pipe devices, the invention is provided with a condensation cavity, and the evaporation chamber is connected with the condensation cavity through a pipeline; and then fins are arranged on the surface of the condensation cavity, thereby increasing the condensation area of the working fluid; at the same time, the loop structure of the condensation cavity effectively increases the effects of natural convection.

A solid adsorbent regenerating device and an adsorption device applying the regenerating device are disclosed. The regenerating device includes a regenerating heater and an absorbent bed. The regenerating device is configured in a manner that heating by the regenerating heater allows gas in the regenerating device to circularly flow between the regenerating heater and the adsorbent bed, and heat provided by the regenerating heater is transferred through the circular airflow to the adsorbent bed so that an adsorbent is heated and regenerated. According to one embodiment, the inside of a furnace body of the regenerating device is divided into two parts, top ends of the two parts are communicated with each other, bottoms of the two parts are communicated with each other, and the regenerating heater is in one of the two parts. The adsorption device applying the regenerating device is also disclosed. Circular heating in a natural convection manner is utilized to regenerate the solid adsorbent. The regenerating device and the adsorption device have advantages of low consumption of inert gas, no or extremely low waste emission, a high heat efficiency, simple equipment, a low cost, and the like.

The invention relates to a high/low temperature space environment simulating container with a high temperature change rate, comprising a main cabin body, a cabin door, a head sink arranged in the main cabin body, a door sealing structure for connecting the main cabin body and the cabin door, an insulating channel passing through the main cabin body, a sample carrier table, a high/low temperature camera assembly, a high/low temperature fluid stirrer, a temperature measuring system, a pressure measuring system and a vacuumizing structure. A non-high-vacuum environment is formed in the container and is filled with helium; besides radiative heat transfer same as the heat transfer manner of a heat vacuum tank, natural convection heat transfer, even forced convection heat transfer, is added in the cabin, so heat transfer speed is increased greatly, a high/low temperature environment (68K-373K) with a high temperature change rate and even temperature is provided to a sample to be measured. The high/low temperature space environment simulating container is stable, safe and reliable to work.

An electrolytic cell combined into a unitary structure with a liquid circulation fitting, which purifies water by electrode plates inside the cell when an aqueous solution is present. The unitary structure replaces the existing water return fitting. This integrated structure is well suited for use in pools, tubs, spas, fountains or similar large liquid containers. The production of halogen inside the structure is not required to coincide with the cycle of the existing pool filtration system. Rather, the electrodes receive a continuous supply of low level power and the halogen produced inside the structure is disbursed back into the body of water through the fitting using an integrated, dedicated circulation pump, special channels in the surface and a check valve to insure one directional flow from the pool pump and natural convection. Using fresh water drawn from the vessel, halogen is then disbursed back into the vessel with the water at a location different from where the fresh water was drawn. The level of halogen production may be regulated using a timing mechanism and/or sensors in the circuitry.

A display device, and a blower thereof are disclosed. The display device includes an axial flow fan within a case, which has a display panel encased therein. The axial flow fan is provided in a width direction within the case, so that, while being rotated within the case, the axial flow fan generates forced air flow suitable to the case. The forced air flow is generated in a forward direction along with air flow by natural convection within the case.

An improved apparatus and method of producing metal foam is provided which involves optimizing the natural convection of electrolyte through a foam being electroplated by inclining the foam during plating. A diagonal flow of electrolyte though the foam enhances electrolyte turnover within the foam while increasing electroplating efficiency. Further increases in plating efficiency are provided by shifting current density from higher plating zones to lower plating zones.