105 results about "Natural convection flow" patented technology

Provided is a natural convection-driven polymerase chain reaction (PCR) apparatus and method, which can periodically change temperature of a sample to make a natural convection-driven flow in a loop-shaped channel on a disposable polymer chip and contacting heating metal members maintained at different temperatures with channels. The natural convection-driven PCR apparatus includes: a polymer chip having a plurality of channels connected together to form a loop-shaped microchannel, a sample being filled inside the channels; a plurality of heating metal members contacting the loop-shaped microchannel of the polymer chip and transferring heat; a temperature controller connected to the heating metal members to maintain the heating metal members at different temperatures; a plurality of heaters connected to the heating metal members and the temperature controller to supply heat to the heating metal members; and temperature sensors connected to the heating metal members and the temperature controller.

A heater assembly with enhanced cooling pursuant to various embodiments described herein makes use of fluidic flow in the insulation or in the space used for insulation. By creating a natural convection or forced convection flow, the heater cools down faster, it can operate at lower temperatures and / or higher temperature precision, and it can improve temperature controllability by generating higher heat loss rates.

Provided is a natural convection-driven polymerase chain reaction (PCR) apparatus and method, which can periodically change temperature of a sample to make a natural convection-driven flow in a loop-shaped channel on a disposable polymer chip and contacting heating metal members maintained at different temperatures with channels. The natural convection-driven PCR apparatus includes: a polymer chip having a plurality of channels connected together to form a loop-shaped microchannel, a sample being filled inside the channels; a plurality of heating metal members contacting the loop-shaped microchannel of the polymer chip and transferring heat; a temperature controller connected to the heating metal members to maintain the heating metal members at different temperatures; a plurality of heaters connected to the heating metal members and the temperature controller to supply heat to the heating metal members; and temperature sensors connected to the heating metal members and the temperature controller.

An electronics module designed to efficiently remove heat from enclosed circuit boards via one or more configurable heat conduits. Each heat conduit is custom-configured to provide good thermal contact between the corresponding heat-generating electronic device of an enclosed circuit board and the clamshell housing that encloses the circuit board. Good thermal contact between the clamshell housing and the outer case of the electronic module facilitates efficient heat transfer to the finned exterior surface of the outer case, where the heat is dissipated into the ambient environment via thermal conduction, natural convection, forced convection, and / or thermal radiation. Depending on the topology of the circuit board and the individual characteristics of the electronic device to be cooled, the corresponding configurable heat conduit might be based on a nested heat-sink coupler, a fitted movable plug, or a flexible ribbon-shaped heat pipe.

Water flow field inlet manifolds (33, 37) are disposed at the fuel cell stack (11) base. Water flow field outlet manifolds (34, 38) are located at the fuel cell stack top. Outlet and inlet manifolds are interconnected (41-43, 47, 49, 50) so gas bubbles leaking through the porous water transport plate cause flow by natural convection, with no mechanical water pump. Variation in water level within a standpipe (58) controls (56, 60, 62, 63) the temperature or flow of coolant. In another embodiment, the water is not circulated, but gas and excess water are vented from the water outlet manifolds. Water channels (70) may be vertical. A hydrophobic region (80) provides gas leakage to ensure bubble pumping of water. An external heat exchanger (77) maximizes water density differential for convective flow.

An LED lamp with a flow guide structure guides external air to dissipate heat from the LED lamp includes a lamp base, a heat dissipating body, a heat dissipating plate and an LED module installed in the lamp base, and heat dissipating holes formed on the lamp base. The heat dissipating body includes heat dissipating fins, and a heat dissipating passage defined between any two fins and disposed corresponding to the heat dissipating hole. The LED module is in a thermal contact with the heat dissipating plate. The heat dissipating plate is attached onto the heat dissipating fins and includes openings. A flow guide plate is formed at a lateral edge of each opening and extended from the heat dissipating plate for guiding external air into the heat dissipating passage and out from the heat dissipating hole to expedite a natural convection in the lamp and prevent a thermal aggregation.

The invention discloses a micro heat flow accelerometer, namely a micro sensor, and making method, composed of sealed monocrystal silicon wafer, heater wire, temperature sensor, inner and outer cavities, detecting circuit and so on. It uses gas as sensitive medium and using the theory that gas's natural convection changes under the action of acceleration to measure the acceleration in the direction of one or two coordinate axes. The heater wire and temperature sensor are suspended and fixed on the silicon cavity. The heat field produced by the heater wire changes when accelerated, the detecting circuit detects the temperature change of the temperature sensor so as to measure the acceleration value. It has no detecting mass block, elastic or strain beam, etc, so having reliable performance, simple and ripe technique, low making cost and so on, and it is specially applied to intelligent cannonball, car, toy, etc.

The present invention provides a solid-state lighting fixture and lamp for down light for use in applications especially in recessed lighting. In particular, the lamp of the subject invention may be configured as a direct screw-in replacement for common R-30 style incandescent flood lamp and it may be used existing luminaires. In one preferred embodiment of the present invention, a lamp mounted in a recessed light luminaire for down lighting has one or more light emitting diodes (LEDs) that are thermally coupled to a heat sink having fins for cooling by ambient air. The fins are configured so that air warmed by the fins can rise inside the luminaire and transfer its heat to it. Air cooled by the luminaire is allowed to sink and may flow out of the luminaire via a gap between the heat sink and the luminaire. Fresh cooler air may be drawn in between the fins to replace out-flowing air. This process of heating and cooling of air established a natural convection flow. Natural convective air flow allows for efficient thermal communication between the heat sink and the luminaire, thereby allowing for lower LED junction temperature and longer LED lifetime.

Disclosed herein is a Czochralski method single-crystal silicon growth flow field control technology. In the technology, a natural convection Gr from outer side to center of a melt is formed in a main heater, so that through rotation of a crucible, the melt flows from the outer side of the crucible to the center with axial temperature gradient Tc. Rotation of the crystal forms a forced convection Re. A bottom heater is arranged on the bottom of the crucible, which enables the temperature at the bottom of the cruible to be higher than that of the periphery of the cruible to form convection Gz from the center in an upward manner. The bottom heater is in a double-spiral involute structure and is moved vertically with the crucible synchronously. The melt is divided into an inner flow field zone and an outer flow field zone by means of control of the condition Gz*Re > Gr*Tc, wherein the two flow field zones are mixed at the central zone of the crystal and a crucible wall with an optimum point position being (d<si>+d<c>) / 2. The technology can control the temperature distribution at the growth interface of the crystal and the oxygen distribution in the melt, and further control element uniformity in the crystal through pulling rate.

The invention discloses a novel gas-liquid heat-exchange device, comprising a main heat exchange plate and a plurality of auxiliary heat exchange fins. The device is characterized in that a liquid inlet and a liquid outlet are formed on the main heat exchange plate; a main liquid inlet channel and a main liquid outlet channel connected with the liquid inlet and the liquid outlet respectively are arranged inside the main heat exchange plate; the auxiliary heat exchange fins are vertically and alternately distributed on the main heat exchange plate in parallel, a liquid inlet subchannel and a liquid outlet subchannel which are respectively connected with the main liquid inlet channel and the main liquid outlet channel are arranged in each auxiliary heat exchange fin, and a plurality of secondary subchannels which are in vertical through connection with the liquid inlet subchannel and the liquid outlet subchannel are arranged in each auxiliary heat exchange fin. The novel gas-liquid heat-exchange device achieves the aim of heat exchange just by own structure and natural convection of air, reduces the volume, saves the cost, and prolongs the service life.

The invention discloses a filled aerogel ICF cryogenic target system which comprises a gold cavity, wherein a pellet is fixed in the center inside the gold cavity through a support membrane; a fusion material is arranged inside the pellet; a laser incident hole is formed in the top of the gold cavity; a thermal mechanical structure is arranged outside the gold cavity; the upper part and the lower part of the thermal mechanical structure are integrally connected through a connecting structure; a cryogenic ring is arranged on the thermal mechanical structure; a thin aerogel layer is arranged on the inner wall of the gold cavity; the cavity of the thin aerogel layer is filled with a filling gas; filling aerogel is arranged at the upper end and the lower end of the thin aerogel layer; the filling aerogel is fixed through fixing membranes; a cavity of the thin aerogel layer between the upper filling aerogel and the lower filling aerogel is filled with the filling gas. Due to existence of the thin aerogel layer and the filling aerogel, gold plasma expansion can be inhibited, the content of the filling gas inside can be reduced, and the influence of natural convection flow can be reduced, so that the temperature uniformity of the temperature of the pellet can be optimized, and the ignition success rate can be increased.

The invention relates to a special-shaped multi-dimensional phase change radiator, and belongs to the technical field of radiators. The special-shaped multi-dimensional phase change radiator comprisesa base plate and fins, wherein at least two groups of fins are vertically fixed on the base plate, straight grooves are formed between the adjacent groups of fins, and the fins are not arranged at the grooves; an included angle is formed between each fin and each groove, and the included angle is an acute angle; and a first cavity is formed in the base plate, a second cavity is formed in each fin, the first cavity communicates with the second cavities, and a phase change working medium is stored in the first cavity and the second cavities. According to the special-shaped multi-dimensional phase change radiator, the problems that an existing natural convection radiator is very non-uniform in heat distribution in a natural convection application, the high-temperature area is mainly concentrated in the upper and middle part of the base plate, the heat exchange efficiency of the fins is not high, and the temperature difference is large are solved.

The invention belongs to the field of heat flow sensor calibration, and relates to a heat flow calibration method for a ground heat intensity cabin test of an aerospace plane, which comprises the following steps of: measuring the temperature of a dummy test piece by placing a standard heat flow density sensor and a to-be-calibrated heat flow density sensor in the same symmetrical working environment; the heating devices are symmetrically arranged on the two sides of the false test piece, the temperature measuring sensor is arranged on the false test piece, and the temperature difference measured by the standard heat flux sensor and the heat flux sensor to be calibrated is compared at the same temperature point, so that the numerical value of the heat flux sensor to be calibrated can be corrected efficiently and accurately; the unpredictable convective heat transfer influence in the experiment can be accurately quantified through the benchmarking standard heat flow density sensor, the heating precision of the heat flow test is improved, and the examination of the ground heat intensity test on the structural member is more accurate and effective. A guiding effect is achieved on the measurement of convective heat transfer by using the total heat flux density sensor; and meanwhile, natural convection and forced convection tests can be respectively carried out.

The invention aims to reduce the cost of a structural member and improve the heat dissipation performance, and provides a semiconductor light source radiator and a light source engine. The semiconductor light source engine is characterized in that a, the structure (the casing) serves as a cooling fin, namely a radiating metal casing (1) machined and formed through punching a sheet metal (aluminum plate), so that the machining cost and material cost are reduced; b, the wall thickness of the radiating metal casing is optimized to further reduce the material cost; c, the metal side wall (2) is formed through stretching a rear metal casing (9) or / and a front metal casing (4), a ventilating window (3) adopting a louver type or staggered arrangement type structure is formed, the ventilating ratio is not less than 0.20, so that air in natural convection flows smoothly, and the radiating performance is remarkably improved; and d, a reflector (31) is equipped, and most light emitted from a semiconductor light source (6) is light reflected by the reflector, so that the light source engine can solve the problem of dazzling light.

The invention relates to a cabinet air conditioner. The cabinet air conditioner comprises a partition plate, a front cover and a rear cover, the front cover and the rear cover are oppositely buckled on the front side and the rear side of the partition plate respectively, an inner circulation heat exchange cavity is formed between the front cover and the partition plate, an outer circulation heat exchange cavity is formed between the rear cover and the partition plate, and the inner circulation heat exchange cavity and the outer circulation heat exchange cavity are isolated through the partition plate. A base plate in an outer circulation system is provided with a flow channel for a refrigerant to flow, the outermost side of the base plate is provided with heat dissipation fins directly exposed to the outside space, and heat dissipation is conducted through natural convection of air. The cabinet air conditioner is reasonable and compact in structural layout, corrosion-resistant in material, simple and convenient in modular design and processing, relatively low in cost, easy to mount and maintain, relatively low in noise during working, attractive in appearance and excellent in heatexchange effect.

The invention discloses a temperature signal detecting device, which comprises a temperature sensor, a control circuit and a mechanical filter. The filter is mainly composed of an energy storage portion having a rectangular parallelepiped shape and a fin portion having a sheet shape, and at least one surface of the fin portion and the energy storage portion is thermally contacted and fixed, and the energy storage portion is provided with a temperature measuring portion suitable for temperature measurement. The temperature sensor is assembled with the temperature measuring portion to detect thetemperature of the end of the temperature measuring portion. The fluid is subjected to heat treatment, the temperature distribution is not uniform, a natural convection flow field is formed under theaction of gravity, the flow of the fluid generates ultra-low frequency disturbance signals with a period as high as a magnitude of several minutes for temperature detection, an electronic filter is difficult to filter out, the detecting device of the invention can filter out the above-mentioned ultra-low frequency disturbance signals and accurately detect the temperature of the fluid, and in theprocess of applying heat treatment, influences of disturbance signals does not exist, the fluctuation of the fluid temperature is extremely small, the fluid temperature is more easier to be stabilizedin a setting value, the consumed time is short, and energy consumption is saved.

The invention relates to a sugar liquid evaporator with sharp expansion and accelerated flow converging-diverging tubes inserted with twisted leaves. The sugar liquid evaporator is characterized in that: the sugar liquid evaporator comprises a cylindrical shell, and an upper steam chamber, an upper tube plate, sharp expansion and accelerated flow converging-diverging tubes inserted with twisted leaves, a central downcomer, a lower tube plate and a lower head which are sequentially arranged in the cylindrical shell, wherein the axis of the central downcomer is coincident with the axis of the cylindrical shell; and the bottom of the lower head is provided with a tube side sugar liquid outlet and a tube side sugar liquid inlet, the top of the upper steam chamber is provided with a tube side secondary steam outlet, and a shell side primary steam inlet and a shell side condensed water outlet are arranged on the cylindrical shell between the upper tube plate and the lower tube plate. By utilizing the local intelligent repeated displacement and the disturbance of periodic converging-diverging rib surfaces and the inserted twisted leaves of the converging-diverging tubes to main flows in the tubes and fluids close to walls of the tubes in the sugar liquid evaporator, the sugar liquid evaporator allows the concentration and the viscosity of the sugar liquid which is on a channel section and is obtained by the flow boiling evaporation under natural convection conditions to be uniformly distributed, the convective heat transfer coefficient and the convective diffusion capability of the fluids in the tubes to be substantially improved, a phenomenon that concentration distributions and concentration distributions of the sugar liquid at central fluid parts and at places close to the walls are not uniform to be improved, and the wall area scale of the sugar liquid to be reduced.

An apparatus to preferentially temper a liquid (only heat it, or, only cool it) by heat exchange with a fluid of indeterminate temperature. A tank of the liquid is plumbed to a liquid dispenser such as a water faucet, heater or chiller and has a internal heat exchanger sealed through each end. A drainpipe with a slit sleeve for double-wall safety, passes through the housing with an annular space between and is connected to a supply of fluids. A gasket seals the space forming a conduit for the liquid. One end of the housing extends from the tank for the liquid inlet. The conduit has natural convection holes into the tank controlled by convection valves which are moved by convection allowing convection only in the direction which preferentially tempers the liquid in the tank, regardless of the temperature, volume, rate, and time of flow of fluids.

The invention provides an electrical oil heater with high thermal efficiency. The electrical oil heater comprises a plurality of heat sinks which are tightly arrayed in sequence, wherein each heat sink is provided with an oil storage bag and a radiating fin; the oil storage bags in the heat sinks are merged and arrayed in sequence and are sealed to form an inner cavity used for containing conduction oil; the inner cavity is provided with an electric heating bar used for heating the conduction oil; a preset angle is formed between the radiating fins and the oil storage bags; under the angle, turbulent flow used for limiting hot air from flowing to the side edge is formed between a previous heat sink and a next heat sink, hot airflow flows from bottom to top in a one-way mode, and the effect of air natural thermal convection is effectively promoted; under the same width condition, the effective area of heat radiation is enlarged, the whole radiating effect of the electric oil heater is effectively promoted, and the energy-saving effect and high efficiency are realized.

The invention relates to a cold and heat convection radiation device and equipment. The cold and heat convection radiation device comprises a heat exchange body, a heat exchange medium channel is formed in the heat exchange body, an inlet of the heat exchange medium channel is used for being communicated with a flow inlet pipe communicated to a heat exchange source, an outlet of the heat exchange medium channel is used for being communicated with a flow outlet pipe communicated to the heat exchange source, multiple radiation grooves are formed in the outer wall of the heat exchange body, and an air convection hole is formed in the heat exchange body. The cold and heat convection radiation equipment comprises the flow inlet pipe, the flow outlet pipe, the heat exchange source and the above cold and heat convection radiation device; the flow inlet pipe and the flow outlet pipe are communicated with the heat exchange source, the inlet of the heat exchange medium channel is communicated with the flow inlet pipe, and the outlet of the heat exchange medium channel is communicated with the flow outlet pipe. The cold and heat convection radiation device and equipment have the functions of natural convection and cold and heat radiation at the same time, during use, no obvious wind feeling exits, and the comfort is high.

The invention relates to a large-power LED radiating structure. The large-power LED radiating structure comprises a shell, a radiating bottom plate attached to an LED heat source, heat-conducting pipes and radiating fins. The shell comprises radiating plates with radiating grooves; the radiating fins are arranged in a cavity defined by the shell; the heat-conducting pipes are divided into the first heat-conducting pipes and the second heat-conducting pipes; the first heat-conducting pipes are connected with the radiating bottom plate and extend in the axial direction in the radiating plates; and one ends of the second heat-conducting pipes are connected with the radiating bottom plate, and the other ends of the second heat-conducting pipes penetrate through the radiating fins. Compared with the prior art, according to the large-power LED radiating structure, heat on a radiating base is conducted to the radiating fins and the radiating plates on the shell of the radiating structure, andthe exchange speeds of hot air in the different directions are different, so that the radiating efficiency can be improved, and the natural convection radiating capability is promoted.

The invention provides a low-thermal-resistance natural convection radiator for a semiconductor refrigerator. The low-thermal-resistance natural convection radiator comprises an evaporator, a steam pipeline, a condenser, a liquid pipeline, a liquid storage device and a heat transfer working medium, wherein the evaporator comprises a steam outlet hole and a liquid inlet hole, and the condenser comprises a steam inlet hole and a liquid outlet hole; the steam outlet hole of the evaporator is connected with the steam inlet hole of the condenser through the steam pipeline; the liquid inlet hole ofthe evaporator is connected with the liquid outlet hole of the condenser through the liquid pipeline; the surface of the evaporator is a hot end mounting surface of the semiconductor refrigerator; a plurality of micro-channels arranged in a vertical array are arranged inside the condenser; the condenser is arranged above the evaporator; and the liquid storage device is arranged in the evaporator and communicates with the evaporator. According to the low-thermal-resistance natural convection radiator for the semiconductor refrigerator, the effective heat radiating area of the low-thermal-resistance natural convection radiator is large, the heat transfer capacity of a bottom layer heat transfer technology is high, and therefore the heat radiating capacity is high, and the refrigeration efficiency of the system can be effectively guaranteed.

The invention provides a PCR (Polymerase Chain Reaction) device based on a low-melting-point metal liquid drop and an implantation method of the PCR device. The PCR device is characterized in that serving as a micro-resistor, the metal liquid drop generates joule heat by electrifying so as to provide heat for PCR, and the metal liquid drop can be cooled through an active cooling manner or the natural convection of air around the metal liquid drop, the temperature of the metal liquid drop can be directly measured by adopting a micro-thermocouple or indirectly measured by measuring the resistance of the metal liquid drop, a PCR reagent liquid drop sample is adhered to the interior of a miniature container under the action of surface tension, the miniature container is buckled down in the center of the metal liquid drop so as to ensure that the reaction reagent liquid drop is in the metal liquid drop all the time, the joule electric current of the metal liquid drop is adjusted by a temperature control module, and the cyclic change of RCR temperature is completed by a cooling device. The low-melting-point metal liquid drop can serve as a PCR reaction carrier, so that the RCR time can be greatly shortened, and the reagent sample is effectively prevented from being lost due to evaporation in the PCR process.

A natural passively cooled ventilated cask includes a cavity which holds a canister containing heat and radiation emitting spent nuclear fuel assemblies. Cooling air inlet ducts draw ambient cooling air inwards into a lower portion of the cavity. The air heated by the canister flows upwards along the canister and is discharged from at least one air outlet duct formed by the cask lid to atmosphere via natural convective thermo-siphon flow. The air inlet ducts or at least one outlet duct in one embodiment may be fitted with an adjustable shutter plate which allows the flowrate of air entering the cask to be increased or decreased to maintain a predetermined canister maximum temperature limit selected in part to prevent the onset of stress corrosion cracking of the canister welds. Other embodiments may use a fixed orifice plate replaceable over time to maintain the minimum temperature.

The invention relates to the field of clothing, and provides an inflation device with adjustable thermal resistance. An air bag is filled with wadding to increase the content of internal still air, so that the stability of the still air is improved, excessive natural convection in the air bag caused by external environment change or human body activity is avoided, the adjustable range of the thermal resistance of the inflation structure is greatly improved, so that the improvement effect of the change of the inflation volume on the heat retention property of the clothes is more obvious, and the requirement for effectively adjusting the thermal resistance of the clothes in production and life scenes can be practically met.

The invention relates to the technical field of air conditioners, in particular to a fluorine pump air conditioner unit cabinet which comprises a cabinet body with a mounting cavity and an isolation cavity. An electric control box is arranged in the mounting cavity and is adjacent to the isolation cavity; one side of a radiator is connected with an electric control board in the electric control box, and the other side of the radiator penetrates out of the electric control box and is arranged in the isolation cavity. The isolation cavity is provided with a first air inlet and a first air outletwhich are communicated with the outside, the first air inlet is located under the radiator, and the first air outlet is located over the radiator; the isolation cavity forms a natural convection flowchannel through the first air inlet and the first air outlet. According to the fluorine pump air conditioner unit cabinet, through arrangement of the isolation cavity, heat of the radiator can be directly dissipated into the external environment, the temperature of the electric control box can be lowered, meanwhile, the overall temperature in the cabinet body is lowered, and the fluorine pump airconditioner unit cabinet can be used under the condition that the environment temperature is high; in addition, the mounting cavity of the cabinet body can sealed while heat dissipation is achieved,and influence of external moisture and the like on the reliability of internal electric control devices is avoided.