Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects

Definitions

• the invention relates to a power supply device by thermoelectric conversion, comprising a thermoelectric converter formed of a plurality of thermocouples connected in series, this converter having a hot face whose thermocouples are exposed to a heat source and a cold face of which the thermocouples are at a temperature lower than that of the thermocouples of the hot face, the temperature difference between the thermocouples of the two faces determining the electric voltage generated by the converter.
• a heat source such as the flame of an oil lamp to produce, when the lamp is on, sufficient electrical power to power a radio transistor receiver. This would allow populations in regions without electrical power distribution networks to receive information by radio, without having to use electric batteries which discharge very quickly in hot and humid climates and which are cannot sometimes be easily replaced.
• thermocouples sufficient to produce an output voltage of several volts, in particular for supplying a radio receiver at transistors, and the cold side of the converter must also be sufficiently cooled when its hot side is exposed to the flame of an oil lamp. Otherwise, a temperature equilibrium between the hot side and the cold side of the converter, the output voltage of which would then become substantially zero.
• thermoelectric conversion supply device comprising a converter comprising a plurality of thermocouples connected in series and having a hot face intended to be exposed to a heat source and a cold face associated with means of heat dissipation, characterized in that these heat dissipation means comprise means for dissipating or absorbing axial heat spaced apart from the cold face of the converter and connected to the latter by a rod or a tube made of material thermally conductive.
• This device makes it possible to move away from the converter the means of dissipation or absorption of heat which are connected to its cold face and therefore to remove these means from the influence of the heat source. It is thus possible to maintain the cold face of the converter at a temperature markedly lower than that of its hot face and therefore to guarantee a sufficient level of the output voltage of the converter.
• the aforementioned rod or tube is contained in a protective sheath against the heat produced by the aforementioned source.
• the aforementioned sheath covers the cold face of the converter to protect it from radiated heat and hot gases and extends to the means of heat dissipation or absorption.
• the rod or the tube which connects the cold face of the converter to the heat dissipation or absorption means is a heat pipe.
• This heat pipe which extends between the cold face of the converter and the means of dissipation or absorption of heat, makes it possible to maintain the cold face of the converter appreciably at the same temperature as the means of dissipation or absorption of heat. The temperature difference between the hot face and the cold face of the converter is then maximum, which generates maximum production of electrical energy by the converter.
• such a converter is particularly well suited to the power supply of a transistor radio receiver, from the heat of the flame of a hurricane lamp.
• FIG. 1 is a partial schematic view of a converter according to the invention
• - Figure 2 is a schematic top view of this converter
• FIG. 3 schematically shows an oil lamp equipped with a converter according to the invention
• - Figure 4 is a top view of the heat dissipation means of the converter of Figure 3;
• FIG. 7 is a schematic top view of the energy dissipation means of the device in FIG. 6.
• FIGS. 1 and 2 schematically represent a thermoelectric converter according to the invention.
• This converter C essentially consists of two perforated discs 10 of electrically and thermally insulating material, such as for example mica or mica-silicone, which are axially aligned and connected by an axial rod 12 comprising at its ends means 14 for fixing on discs 10.
• each disc 10 comprises a plurality of holes 16 which are for example distributed in concentric circles and through which pass the ends of parallel wires 18, 20 which are arranged alternately and which are formed of two different electroconductive materials conventionally used to form thermocouples (for example a nickel-chromium alloy and a nickel-copper alloy).
• the wires 18, 20 are threaded in axially aligned holes 16 of the disks 10 as shown in FIG. 1, and the ends of the neighboring wires of different nature are joined together two by two by welding on the external faces of the disks 10 to form the thermocouples properly said.
• thermocouples are connected in series, one end of a wire 18 on one face of a disc 10 being joined by welding to one end of a neighboring wire 20, the other end of which is joined by welding on the outer face of the another disc 10 at one end of another neighboring wire 18, and so on.
• the arrangement of the wires 18, 20 in the holes 16 of the discs 10 and the two-to-two welds of the ends of the wires can be carried out automatically at high speed on machines for mounting components on printed circuits, for example in the manner next :
• the two discs 10 are brought together on the spacer 12 and are placed between two wire positioning heads, one being supplied with wire 18 and the other with wire 20.
• Each head advances a predetermined length, for example of approximately 50 mm, of wire 18, 20 in two axially aligned holes 16 of the two discs 10, then two pliers come to grip the wires and cut them, after which two welding heads located on either side of the discs 10 carry out the junction of the ends of the neighboring wires 18, 20. It is then necessary to rotate the discs 10 by one step and repeat the operations which have just been described.
• Existing machines allow two wires to be laid and welded in less than a second. The production rate can be very greatly increased when using multiple heads making it possible to place and weld several wires simultaneously in the holes 16 of the disks 10.
• a converter such as that represented in FIGS. 1 and 2, can comprise approximately 600 thermocouples, in a size which is that of a cylinder with a height and a diameter of about 45 mm.
• the discs 10 made for example of mica-silicone withstand temperatures above 800 ° C.
• the discs and the welds of the wires 18, 20 can be embedded in a refractory cement, as well as possibly all of the wires 18, 20 between the disks 10. Washers of a material which is a good conductor of the heat, such as copper for example, can then be placed on the outer faces of the discs 10 to standardize the temperatures at each end of the converter.
• this converter When this converter is to be exposed to the flame of an oil lamp or a hurricane lamp as shown diagrammatically in FIG. 3, it is suspended above the hearth 22 of the lamp 24, inside the glass 26 of this lamp, so that the underside 28 of the converter or hot face can be brought to a maximum temperature by the combustion flames when the lamp is on.
• the other end face 30 of the converter or cold face is connected by a tube or an axial rod 32 to axially distant means of heat dissipation formed by an annular radiator 34 placed on the upper part of the lamp, for example between the upper ring 36 of the lamp and its side handles 38.
• the device according to the invention advantageously comprises a cylindrical sheath 40 which extends axially between the cold face 30 of the converter and the radiator 34, around the rod 32 and which ends at its upper end by an annular rim 42 which closes the upper part of a duct 44 which covers the glass 26, this annular rim comprising small cylindrical ducts 46 which extend axially between the sheath 40 and the internal cylindrical surface of the radiator 34 and which open to the outside under the cover 48 carrying the ring 36.
• the sheath 44 is preferably made of thermally insulating material. It can also be formed from a double-walled tube, the space between the two tubes being able to be closed and filled with air or with a thermally insulating material (refractory cement for example).
• the annular rim 42 of this sheath advantageously has a structure similar to that of the sheath.
• the outer surface of the sheath 40 can be reflective, and its inner surface can be black.
• the radiator 34 is carried by the upper end of the axial rod 32, by means of a star part whose central part 50 is fixed on the upper end of the rod 32 and whose radial arms 52 are fixed to their free end on the radiator 34.
• the combustion flame comes to bring the lower face 28 of the converter to a temperature of the order of 600 ° C.
• the upper face 30 of the converter is connected by the axial rod 32 (which is made of a material that conducts heat well, for example copper) to the radiator 34 which is located outside the lamp.
• the hot combustion gases are guided in the space between the sheath 40 and the conduit 44 and escape to the outside through the aforementioned small conduits 46. So, the rod 32 which connects the cold face 30 of the converter to the radiator 34 is protected from the radiation of the flame and from contact with the combustion gases. The same goes for the radiator 34.
• FIG. 5 differs from that of FIGS. 3 and 4 in that the sheath 40 extends to the hot face 28 of the converter C, this face 28 then being the only part of the converter which is exposed to the flame of the lamp and the combustion gases, the rest of the converter being inside the sheath 40.
• the cold face 30 of the converter is connected by a copper rod 32 to the radiator 34, and the sheath 40 comprises the flange 42 formed with the cylindrical conduits 46 for the outlet of the combustion gases which circulate between the sheath 40 and conduit 44.
• the temperature of the cold face 30 of the converter can be maintained at around 120 ° C. when the hot face 28 is at a temperature of the order of 600 ° C. which makes it possible to further increase the output voltage of the converter and also to reduce the dimensions of the radiator 34.
• the radiator 34 can itself be mounted inside the sheath at the upper end of the latter.
• the air circulation on the radiator can be accelerated by means of the hot gas outlets, which are led to the air outlets for a ripple effect of this air after it has passed over the radiator.
• the air intakes bringing outside air into the sheath can be pipes with a thermally insulating coating.
• the hot gas outlets 46 can form ejectors opening into the air outlets, or conversely, the air outlets can lead into the hot gas outlets 46, as shown by the small arrows.
• the hot face 28 of the latter can be equipped with a radiator with fins or pins made of heat-conducting material, as shown in phantom lines.
• the converter C is placed inside the sheath 40 as in the previous embodiment, only its hot face 28 being exposed to the flame and to the combustion gases, and its cold face 30 is connected to the radiator 34 by a duct 54 of the "heat pipe” type.
• This type of conduit makes it possible to maintain the cold face 30 of the converter at a substantially constant temperature, corresponding to a liquid-vapor equilibrium condition of a working fluid contained in the heat pipe, any rise in temperature at the end of the heat pipe. joined to the cold face of the converter being immediately compensated by heat transfer to the radiator 34 associated with the other end of the heat pipe.
• Heat pipes of this type are commercially available.
• a heat pipe 54 in place of the copper rod 32 makes it possible to maintain the cold face 30 of the converter at a temperature of the order of at least 100 ° C. when the hot face 28 is at a temperature of l '' order of 600 ° C, which increases the value of the voltage generated by the converter and reduces the size of the radiator 34, which can thus be housed inside the sheath 40 at the upper end of this one.
• outside air inlets can be formed in the duct 40 to establish air circulation on the radiator 34, as indicated above.
• the combustion gases circulate between the sheath 40 and the duct 44 and escape outside through the ducts 46 provided on the annular rim 42 of the sheath 40.
• the converter C makes it possible, when the lamp 24 is on, to supply electrical energy to a radio transistor receiver.
• the converter C associated with a storm lamp 24 can be used to power an ultrasonic transmitter of the type intended to repel insects such as mosquitoes.
• this converter can be used with other heat sources than an oil lamp or a hurricane lamp.

Landscapes

• Arrangement Of Elements, Cooling, Sealing, Or The Like Of Lighting Devices (AREA)
• Resistance Heating (AREA)
• Power Conversion In General (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9529457

Family Applications (1)

Country Status (7)

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Family Cites Families (6)

• 1998
  • 1998-08-05 FR FR9810106A patent/FR2782191A1/fr not_active Withdrawn
• 1999
  • 1999-08-03 CN CN99810769.7A patent/CN1317156A/zh active Pending
  • 1999-08-03 WO PCT/FR1999/001917 patent/WO2000008692A1/fr not_active Ceased
  • 1999-08-03 EP EP99936675A patent/EP1112598A1/de not_active Withdrawn
  • 1999-08-03 BR BR9912737-7A patent/BR9912737A/pt not_active IP Right Cessation
  • 1999-08-03 AU AU51688/99A patent/AU5168899A/en not_active Abandoned
• 2001
  • 2001-01-31 ZA ZA200100855A patent/ZA200100855B/en unknown

Non-Patent Citations (1)

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