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
  • H10N10/10—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects operating with only the Peltier or Seebeck effects
  • H10N10/13—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects operating with only the Peltier or Seebeck effects characterised by the heat-exchanging means at the junction
• • 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
  • H10N10/10—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects operating with only the Peltier or Seebeck effects
  • H10N10/17—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects operating with only the Peltier or Seebeck effects characterised by the structure or configuration of the cell or thermocouple forming the device

Definitions

• Thermoelectric module and device in particular for generating an electric current in a motor vehicle
• the present invention relates to a module and a thermoelectric device, in particular for generating an electric current in a motor vehicle.
• thermoelectric devices using so-called electric thermo elements, for generating an electric current in the presence of a temperature gradient between two of their opposite faces according to the phenomenon known as Seebeck effect.
• These devices comprise a stack of first tubes, intended for the circulation of the exhaust gases of an engine, and second tubes, intended for the circulation of a heat transfer fluid of a cooling circuit.
• the electrical thermo elements are sandwiched between the tubes so as to be subjected to a temperature gradient from the temperature difference between the hot exhaust gases and the cold cooling fluid.
• Such devices are particularly interesting because they make it possible to produce electricity from a conversion of the heat coming from the exhaust gases of the engine. They thus offer the possibility of reducing the fuel consumption of the vehicle by replacing, at least partially, the alternator usually provided therein to generate electricity from a belt driven by the engine crankshaft. .
• thermoelectric elements of annular shape
• the hot fluid and the cold fluid then circulate coaxially, one circulating inside the ring and the other outside.
• This solution has integration difficulties that cause the commitment of a large amount of material.
• such a commitment of material increases the thermal inertia of the device and therefore its effectiveness, particularly its response time. It may not be able to take advantage of strong but too short increase of heat.
• thermoelectric module comprising at least one annular-shaped thermoelectric element capable of generating an electric current under the action of a temperature gradient exerted between two of its faces, one, said first face, being defined by a surface, in particular a cylindrical surface, of outer periphery and the other, said second face, being defined by a surface, in particular a cylindrical surface, of inner periphery, said module being configured to establishing a heat exchange between said first face and a first fluid and for establishing a heat exchange between said second face and a second fluid, so that said first fluid and said second fluid circulate transversely, in particular perpendicularly, one compared to each other.
• the thermoelectric module is arranged to guide the first fluid transversely to the second fluid.
• said thermoelectric module is configured to allow a circulation of said first and second fluids, said second fluid having a heat exchange coefficient greater than said first fluid.
• the first fluid is, in particular exhaust gas.
• the second fluid is, for example, a coolant.
• the invention thus proposes a module whose efficiency is optimized by the fact that the exchange surface is larger at the level of the fluid having the lowest exchange coefficient.
• the cylinder formed by said electric thermo elements is thinned in the flow direction of the first fluid so that it offers less resistance to the first fluid.
• the cylinder has in particular a base of substantially oval shape.
• the external thinned form of the electric thermo elements makes it possible in particular to reduce the aerodynamic master torque of the thermoelectric element and thus to reduce the resistance to the flow of gases, for the same overall size.
• thermoelectric element has two opposite parallel flat faces.
• the module comprises a plurality of said electric thermo elements.
• Said thermoelectric elements may be arranged relative to each other so that their first and / or second surfaces are in the extension of one another.
• said electric thermo elements are of two different types.
• said electric thermoelectric elements are here of a first type, called P, making it possible to establish an electric potential difference between said first and second faces, when they are subjected to a given temperature gradient, and of a second type, said N, allowing the creation of an electrical potential difference in an opposite direction between said first and second faces, when they are subjected to the same temperature gradient.
• thermoelectric elements of the same type can alternate in a direction of longitudinal extension of the module with a thermoelectric element of the other type.
• said electric thermo elements are arranged in the longitudinal extension of one another and the P type thermoelectric elements alternate with the N type thermoelectric elements.
• the electric thermoelectric elements are grouped in pairs, formed of a said P type thermoelectric element and a said N type thermoelectric element, said module being configured to allow current flow. between the first surfaces of the thermoelectric elements of the same pair and a flow of current between the second surfaces of each of the electric thermoelectric elements of the same pair and the thermoelectric element adjacent to the neighboring pair, according to one aspect of the invention, said electric thermoelectric elements are of identical shape and size. In other words, they have an inner periphery, an outer periphery and a thickness, that is to say, a dimension along their longitudinal axis, identical. As a variant, their thickness may be different, in particular as a function of their electrical conductivity.
• the elements N-type electric thermocouples may be more electrically conductive than the P-type thermoelectric elements, and the thickness of said N-type thermoelectric elements will be less than the thickness of the P-type thermoelectric elements, or vice versa.
• the electrical resistances of the electric thermoelectric elements of each of the electric thermoelectric element types may be more balanced, with a thinner thickness of N-type thermoelectric elements, or conversely of the P-type, and thus a saving in material.
• the module comprises first electrical connection means connecting the outer periphery surfaces of two of said adjacent, different-type, electrical thermoelectric elements, said secondary exchange surfaces being fixed on said first means of connection. electrical connection.
• the secondary exchange surfaces are, for example crimped to the first electrical connection means.
• they are soldered to said first electrical connection means, in particular using an electrically conductive solder.
• the secondary exchange surfaces are traversed by said electric thermo elements.
• the secondary exchange surfaces extend in planes parallel to the flow direction of the first fluid.
• the secondary exchange surfaces are fins. They are, in particular, metal.
• the secondary exchange surfaces comprise a catalytic coating to provide catalytic conversion of toxic components of the first fluid.
• the module comprises second electrical connection means establishing an electrical connection between the inner periphery surfaces of two of said thermoelectric elements, provided adjacent, of different type and not connected by said first electrical connection means.
• said module further comprises electrical insulation means arranged between two adjacent thermoelectric elements, of different types, said electrical insulation means being configured to electrically isolate between them side faces of the thermoelectric elements connected by said first and / or second electrical connection means and / or to electrically isolate between them the secondary exchange surfaces bonded to two of said thermoelectric elements, connected by the second electrical connection means.
• the invention makes it possible to limit the risk of a short circuit being created between the secondary exchange surfaces.
• the module comprises a circulation channel of the second fluid in contact with said second surface of said thermoelectric elements.
• the channel extends along an eccentric axis with respect to a central axis of the cylinder formed by said thermoelectric elements.
• the eccentric axis of the channel lies in a plane defined by the central axis of the cylinder and the flow direction of the first fluid.
• the thermoelectric elements By orienting the thermoelectric elements with respect to the direction of flow of the first fluid, it has the kind of concentric electrical equipotentials inside the thermo elements.
• the module may also comprise a plurality of cold liquid circulation channels, in particular parallel to each other, each channel cooperating with a plurality of electric thermoelectric elements each forming an angular cylinder section and positioned one after the other. in the direction of longitudinal extension of the corresponding channel.
• thermoelectric device comprising a plurality of modules as described above.
• said secondary exchange surfaces connect the modules together so that they are traversed by said modules.
• said device is configured to allow a flow of the first fluid in a direction transverse to a direction of flow of the second fluid through said modules.
• the device comprises a conduit for guiding the first fluid in a direction of flow of the first fluid, said modules being arranged transversely to said flow direction of the first fluid.
• said device is configured to be positioned in a motor vehicle exhaust gas duct so that said secondary exchange surfaces are swept by said gases, the latter defining said first fluid.
• the exhaust gas duct is, in particular, said guide duct of the first fluid.
• FIGS. 1 and 2 schematically illustrate, in perspective, steps for mounting an exemplary module according to the invention
• FIG. 3 schematically illustrates, in perspective, an exemplary module according to the invention
• FIG. 4 schematically illustrates, in a longitudinal section plane, the module of FIG. 3,
• FIG. 5 schematically illustrates, in perspective, an exemplary device according to the invention comprising several modules
• FIG. 6 schematically illustrates, in perspective, another embodiment of the device illustrated in FIG. 5.
• FIG. 7 schematically illustrates, in perspective, a feature of an exemplary embodiment of the module according to the invention.
• the invention relates to a thermoelectric module.
• Said module here comprises a first circuit 1, said to be hot, capable of allowing the circulation of a first fluid, in particular of the exhaust gases of an engine, and a second circuit 2, said to be cold, capable of allowing the circulation of a second fluid, especially a heat transfer fluid of a cooling circuit, of lower temperature than that of the first fluid.
• the module comprises at least one thermoelectric element, here a plurality of thermoelectric elements 3p, 3n, of annular shape, capable of to generate an electric current under the action of a temperature gradient capable of generating an electric current under the action of a temperature gradient exerted between two of its faces, the one 4a, said first face, being defined by an outer periphery surface, cylindrical, and the other 4b, said second face, being defined by an inner periphery surface, cylindrical.
• said first and second faces 4a, 4b are, for example, oval section for the first and / or circular for the second. More generally, any section of rounded and / or polygonal shape is possible.
• Such elements operate, according to the Seebeck effect, by making it possible to create an electric current in a load connected between said faces 4a, 4b subjected to the temperature gradient.
• such elements consist, for example, of Bismuth and Tellurium (Bi 2 Te 3).
• thermoelectric elements may be, for a first part, elements 3p of a first type, said P, for establishing a difference in electric potential in a direction, said positive, when they are subjected to a temperature gradient given, and, for the other part, elements 3n of a second type, said N, allowing the creation of a difference of electric potential in an opposite direction, said negative, when they are subjected to the same temperature gradient .
• the thermoelectric elements 3 shown are formed of a ring in one piece. They may however be formed of several pieces each forming an angular portion of the ring.
• the first surface 4a has, for example, a radius between 1, 5 and 4 times the radius of the second surface 4b. It may be a radius equal to about 2 times that of second surface 4b.
• Said thermoelectric element has, for example, two opposite planar faces 6a, 6b opposite. In other words, the ring constituting the thermoelectric element is of rectangular annular section.
• thermoelectric elements An example of an association of the thermoelectric elements with one another in the module according to the invention is described below.
• thermoelectric elements 3p, 3n are arranged, for example, in the longitudinal extension of one another, in particular in a coaxial manner, and the P-type thermoelectric elements alternate with the N-type thermoelectric elements, according to a direction D. They are, in particular, of identical shape and size. They may, however, have a thickness, that is to say a dimension between their two planar faces, different from one type to another, particularly depending on their electrical conductivity.
• thermoelectric elements 3p, 3n are, for example, grouped in pairs, each pair being formed of a said P-type thermoelectric element and a said N-type thermoelectric element, and the said module is configured to allow a flow of current between the first surfaces of the thermoelectric elements of the same pair and a flow of current between the second surfaces of each of the electric thermo elements of said pair and the thermoelectric element adjacent to the neighboring pair. In this way, a series flow of electric current is ensured between the electric thermoelectric elements 3p, 3n arranged next to one another in the direction D.
• the module according to the invention may comprise a channel 7 for cold liquid circulation in contact with said second surface 4b of said electric thermo elements 3p, 3n.
• the at least one liquid circulation channel 7 is, for example, of circular section.
• said module comprises cold liquid circulation tube 12 on which at least two electric thermoelectric elements of the same type, alternating in the direction of longitudinal extension D of the tube, with a thermoelectric element of the tube, are mounted.
• the tubes 12 are, in particular, metallic. They define at least in part said channel 7.
• Said module may furthermore comprise electrical insulation means 20 arranged between two faces 6a, 6b facing neighboring thermoelectric elements 3p, 3n in the direction of longitudinal extension D of the tube 12.
• the electric thermo elements 3p, 3n, and the electrical insulation means 20 are assembled, alternately, on the tubes 12 for cold fluid circulation.
• Said module may further comprise first electrical connection means 22 connecting the outer periphery surfaces 4a of two of said thermoelectric elements, provided adjacent and of different types.
• Said first electrical connection means 22 comprise, for example, a layer of electrically conductive material, in particular copper and / or nickel, coating said electric thermo elements 3p, 3n.
• the channel 7 cold liquid circulation is unique and placed in the center of the module.
• a plurality of cold liquid circulation channels may be provided.
• said module is configured to establish a heat exchange between said first face 4a and the first fluid, circulating here in the channel 7 along the arrow illustrated 100, and to establish a heat exchange between said second 4b face and the second fluid, circulating here outside of said thermoelectric elements 3 according to the illustrated arrow 102.
• This promotes the exchange between the electric thermo elements 3, and the fluid having the lowest heat exchange coefficient , here, the exhaust.
• said module is further configured so that said first fluid and said second fluid circulate transversely, in particular orthogonal, with respect to each other, as illustrated by the orientation of the arrows 100 102.
• the thermoelectric module of the invention is thus arranged to guide the first fluid transversely to the second fluid.
• Said module advantageously comprises secondary exchange surfaces 9, in particular fins 104, with the first fluid. In this way, the exchange surface between the electric thermoelectric elements 3 and said first fluid is increased.
• Said fins 104 are arranged, for example, transversely, in particular radially to said electric thermoelectric elements 3.
• the secondary exchange surfaces 9 may include a catalytic coating to provide catalytic conversion of toxic components of the first fluid.
• said module can in this way equip a catalytic converter in addition or substitution of the components conventionally used for catalysis in such equipment.
• said fins 104 are fixed, for example, on said first means 22 of electrical connection, in particular by crimping and / or brazing.
• the module may further comprise second electrical connection means 106 establishing an electrical connection between the inner periphery surfaces 4b of two of said adjacent thermoelectric elements 3, of different types and not connected by said first electrical connection means 22.
• said first and second electrical connection means 22, 106 connect in pairs said electric thermoelectric elements 3 so as to establish an electrical flow in series between said thermoelectric elements of the module.
• the module according to the invention advantageously comprises means 20 of electrical insulation arranged between two adjacent thermoelectric elements 3.
• Said electrical insulation means are of two types.
• a first type 108 is configured to electrically isolate the side faces of the electric thermoelectric elements from one another connected by said first means 22 of electrical connection.
• a second type 110 is configured to electrically isolate between them the lateral faces of the electric thermoelectric elements connected by said second electrical connection means 106 and / or to electrically isolate between them the fins 104 connected to two of said thermoelectric elements, connected by the second means 106 for electrical connection.
• thermoelectric elements 3 which could intervene via said fins 106.
• said channel 7 may extend along an eccentric axis with respect to a central axis of a cylinder formed by said thermoelectric elements 3, represented here in a single block, for the sake of simplification.
• Said eccentric axis of the channel is, for example, in a plane defined by the central axis of the cylinder and the flow direction of the first fluid.
• said cylinder is thinned in the flow direction of the first fluid so that it offers less resistance to the first fluid.
• said first and / or second surfaces 4a, 4b may be coaxial.
• the thermoelectric element is provided with a constant radial thickness.
• the invention also relates to a device comprising a plurality of modules as described above, here in the form of rods 112 stacked next to each other and / or above the others.
• the modules may be connected together in series and / or in parallel, by connections, not shown, located at their longitudinal ends.
• Said fins 104 connect the modules together so that they are traversed by said modules.
• such a device may be configured to be positioned in a motor vehicle exhaust gas conduit so that said secondary exchange surfaces are swept by said gases.
• the gases are intended to be channeled through the fins by the exhaust pipe itself while the circulation of the second fluid can be done by inlet / outlet pipes positioned laterally, where a great simplicity of integration.
• the device thus comprises a guide duct of the first fluid, here the exhaust gas duct, for guiding the first fluid transversely to the modules, that is to say transversely to the longitudinal direction defined by the shapes of the rods. modules.
• the modules are arranged transversely to said flow direction of the first fluid.
• said device is configured to allow a flow of the first fluid in a direction transverse to a direction of flow of the second fluid through said modules.
• the guide duct is therefore transverse to the circulation channels 7 of the second fluid.
• the device may also comprise modules arranged one after the other in the direction of flow of the first fluid, that is to say here one after the other in the guide duct.
• the invention by circulating the hot fluid outside the thermoelectric elements and transversely to the circulation of the cold fluid, makes it possible to optimize the heat exchange surfaces in contact with said elements. thermoelectric, promoting the achievement of high temperatures at the outer surface of said thermoelectric elements. It also promotes the implementation of equipped devices.
• said device generates no current or short circuit at the engine stop or start.

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• Exhaust Gas After Treatment (AREA)

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• 2012
  • 2012-12-28 FR FR1262921A patent/FR3000614B1/fr active Active
• 2013
  • 2013-12-20 WO PCT/EP2013/077833 patent/WO2014102218A1/fr not_active Ceased
  • 2013-12-20 KR KR1020157017229A patent/KR20150091128A/ko not_active Ceased
  • 2013-12-20 EP EP13815757.3A patent/EP2939280A1/de not_active Withdrawn
  • 2013-12-20 US US14/655,483 patent/US20150357546A1/en not_active Abandoned

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