KR101704322B1 - Thermoelectric module and heat exchanger including such a module - Google Patents

Abstract

The present invention relates to a thermoelectric module (10), particularly for automobiles, comprising a thermoelectric element (15) which permits current to be generated in the presence of a temperature gradient and a heat exchanger (20) . The heat exchanger comprises a first surface (21) in heat exchange relationship with a first series of thermoelectric elements (15), a second surface (22) in heat exchange relationship with a second series of thermoelectric elements (15) And a heat exchange means (25) for exchanging heat with the first and second surfaces (21, 22). The present invention also relates to a heat exchanger having such a thermoelectric module (10).

Description

THERMOELECTRIC MODULE AND HEAT EXCHANGER INCLUDING SUCH A MODULE [0001]

The invention relates particularly to thermoelectric modules intended to form part of a heat exchanger.

Using a phenomenon known as the Seebeck effect, a thermoelectric module using thermoelectric elements that allows current generation in the presence of a temperature gradient between two opposing surfaces It has already been proposed. Such a module includes a bundle formed from a stack of a second tube intended for circulation of the heat-conducting fluid in the cooling circuit and the first tube intended for circulation of engine exhaust. The thermoelectric elements are sandwiched between the tubes to be exposed to a temperature gradient resulting from the temperature difference between the hot exhaust gas and the cold cooling fluid.

Such modules are particularly useful because they permit the production of electricity from the conversion of heat resulting from engine exhaust. They therefore have the possibility of reducing the fuel consumption of the vehicle by at least partially replacing the alternator, usually provided therein, for generating electricity from the belt driven by the engine's crankshaft to provide.

Another source of lost heat is on a vehicle with an internal combustion engine as well as other cooling sources such as, for example, air that meets the front of the vehicle. However, conventional thermoelectric modules are not suitable for such fluids and are not particularly suited for recovering cooling energy from air.

The present invention therefore proposes to improve this situation.

The present invention relates to thermoelectric modules, in particular automotive thermoelectric modules, including a thermoelectric element that allows the generation of current in the presence of a temperature gradient and a heat exchange device intended for fluid to pass through. The apparatus includes a first surface in a heat exchange relationship with a first set of thermoelectric elements, a second surface in a heat exchange relationship with a second set of thermoelectric elements, and a second surface in a heat exchange relationship with the first and second surfaces And means for exchanging heat with the fluid in the exchanged relationship.

The present invention thus optimizes the contact between the thermoelectric element and one of the heating or cooling circles defined by the fluid within a limited space. In this way, it is easier to obtain a steep temperature gradient, preferably as constant as possible.

According to an exemplary embodiment of the present invention, the heat exchange means comprises a zone intended to contact the fluid and having a surface area much larger than the surface area of the first and / or second surface. As used herein, " far wider " means an area at least five times wider, especially ten times wider. This area improves the heat exchange between the module of the present invention and the fluid passing therethrough, particularly the recovery of cooling energy.

According to an aspect of the present invention, the heat exchange apparatus includes a first fin including the first face, and / or a second fin including the second face. The first fin and / or the second fin comprise a heat exchange means on one side and a portion in heat exchange relationship with the thermoelectric element on the second side opposite the first side.

Advantageously, the first and second pins are parallel to each other.

According to an exemplary embodiment of the present invention, the heat exchange means is disposed between the first fin and the second fin. The exchange means is particularly brazed to the first pin and the second pin.

According to an aspect of the invention, the heat exchange means is intended to impede fluid flow. Disruption of the fluid improves heat exchange, especially cooling energy recovery.

Advantageously, the heat exchange means comprises an interposed element. In the extension of the above description, the interposer element has a surface which is intended to contact the fluid in particular and has a much larger area than the surface of the fin in contact with the thermoelectric element

According to an aspect of the invention, the intervening element comprises undulations.

According to an exemplary embodiment, the intervening element comprises means for disrupting the fluid flow. Advantageously, said means for disrupting the fluid include louvres.

According to an aspect of the invention, the heat exchange means takes the form of an " offset " baffle. In other words, it comprises strips of wave-like material arranged parallel to each other in the direction of extension of the baffle. The strips are offset relative to each other in the direction to provide a passage for the fluid from the corrugation of one of the strips to the corrugation of the adjacent strip. Thus, the corrugations are offset relative to each other and disrupt fluid flow to improve heat exchange.

According to an exemplary embodiment of the invention, the module comprises a hot tube and a hot pin in a heat exchange relationship with the hot face of the hot tube and the thermoelectric element.

Advantageously, the heat exchange apparatus is configured to form a thermal screen that protects the hot pins. In particular, it is the first pin and / or the second pin configured to form the thermal shielding film protecting the hot pins.

According to an exemplary embodiment, the hot tube passes through a first side and / or a second side having a longitudinal extension direction, the module comprising two said hot tubes < RTI ID = 0.0 > And another heat exchanging means separate between the two further hot tubes spaced apart in the longitudinal axis direction.

The invention thus relates to a heat exchanger, in particular for automobiles, comprising the thermoelectric module defined above.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be better understood in light of the following description, taken in conjunction with the accompanying drawings, which are given by way of illustration only and not by way of limitation.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a perspective view illustrating a first exemplary embodiment of an exchange including a thermoelectric module according to the present invention;
1B is a perspective view illustrating a second exemplary embodiment of the exchange according to the present invention,
2 is a perspective view of a part of a thermoelectric module according to the present invention,
Figure 3 is a perspective view of a portion of the thermoelectric module of Figure 2, with certain portions omitted.

As shown in Fig. 1A, the present invention relates to a heat exchanger, particularly for automobiles, which comprises, as a first function, a bundle 1 that permits heat exchange between a first hot fluid and a second cold fluid . Thus, the exchanger according to the invention is intended to receive two fluids at its inlet, and the first (or hot) fluid has a higher temperature than the second (or cold) fluid.

The hot fluid may be a cooling fluid from the cooling loop of the vehicle engine and the cold fluid may be a flow of ambient air from the front of the vehicle through its radiator. However, other types of fluids, especially different types of high temperature fluids, are also possible. In particular, these fluids may be high temperature fluids whose circuits pass through the front of the vehicle in order to allow their cooling and / or phase change.

In particular, the exchanger is designed such that the hot fluid passes through the exchanger in a first direction (indicated by the arrow marked 3) and the cold fluid is in a second direction (2 indicated by 2 in the figure), which is substantially perpendicular to the first direction (Not shown). The exchanger is fitted with collector boxes (4) to dispense the hot liquid into the bundle (1) and / or to collect the hot fluid from the bundle (1).

Here, the collector box 4 allows the hot fluid to circulate in a U-shape. The upper collector box 4 has an internal partition (not shown) that divides the box into two parts, each having an inlet / outlet tube for the hot fluid. The hot fluid then penetrates through the inlet tube into the first part of the upper collector box and moves down the bundle in the direction 3 past the first part of the bundle and is collected by the lower collector box 4, / RTI > The fluid is moved upwardly in the direction 3 through its other part and finally collected by the second part of the upper collector box 4 and discharged from the exchanger via its outlet tube.

The bundle has, for example, an approximately parallelepiped shape. The collector box 4 is located on two opposing sides of a parallelogram. The bundle has two first opposing faces 5 and two second opposing faces 6 connecting the boxes 4. The exchanger is configured such that the cold fluid flow is perpendicular to the first side (5). The dimension of the bundle or its depth in the direction 2 of the cold fluid flow is, for example, smaller than the other dimensions of the bundle, i. E. Its width and height, i.

The exchanger thus configured is intended to be mounted, for example, on the front of the vehicle. However, the exchange may be located at another location in the vehicle. Similarly, an exchange according to the present invention may have other configurations as intended to be located at the front of the vehicle.

The exchanger includes a thermoelectric element (indicated at 15 in Figures 2 and 3) that allows the generation of current in the presence of a temperature gradient. This is a substantially parallelepiped-like element that generates current using a Seebeck effect, for example when exposed to the gradient between two opposing surfaces of a thermoelectric element called the active surface. These elements allow the generation of current in a charge connected between the active surfaces. In a manner known to those skilled in the art, these elements comprise, for example, bismuth and tellurium (Bi ₂ Te ₃ ).

Wherein the bundle includes a first zone (7) configured to allow the heat exchange between the hot fluid and the cold fluid and a second zone (8) configured to permit generation of the current.

Thus, within the first zone 7, a conventional heat exchange function (the cryogenic fluid cools the hot fluid and the hot fluid heats the low temperature fluid) An exchange functioning to perform both functions of conversion is formed.

According to the first embodiment shown in FIG. 1A, the second zone 8 is preferably a collector box 4 comprising an inlet / outlet pipe, here a bundle 1 connected to the upper collector box 4 ≪ / RTI >

According to the second embodiment shown in Fig. 1B, the first zone 7 and the second zone 8 are provided in parallel in the flow direction of the hot fluid. In this exemplary embodiment, the fluid enters through one of the collector boxes 4 and is discharged through the other of the collector boxes 4.

In a variant (not shown), the exchanger is entirely devoted to converting heat into current. Which is then configured to hold rather than reduce the temperature gradient between the hot fluid and the cold fluid.

The heat exchanger according to the invention comprises a thermoelectric module (10) located in a second heat exchanger zone.

As shown in FIGS. 2 and 3, the thermoelectric module includes a thermoelectric element 15 and a heat exchanger device 20, and the low temperature fluid is intended to pass through the heat exchanger device. The apparatus 20 includes a first surface 21 in a heat exchange relationship with a first series of thermoelectric elements 15 and a second surface 22 in a heat exchange relationship with a second series of thermoelectric elements 15 ) And heat exchange means (25) with the cold fluid in heat exchange relationship with the first and second surfaces (21, 22). The heat exchange means 25 ensures a large area contact with the fluid to promote the maintenance of the temperature gradient in the thermoelectric element 15 through the first and second surfaces 21,

The first and second surfaces 21 and 22 have a longitudinal extension direction D and the hot tubes 30 pass therethrough without thermal contact therewith. The hot tubes 30 are, for example, rectangular in shape parallel to each other and allow penetration of the hot fluid. The hot tubes 30 open into the collector box at their respective ends via, for example, passage orifices provided in the collector plate of the box. The exchanger includes separate heat exchange means (25) between two adjacent hot tubes (30) in the longitudinal axis direction of the first and second surfaces.

The hot tube 30 is in thermal exchange relationship with a flat hot pin 33 extending perpendicularly to the hot tube 30 and the hot tube 30 passes through the hot pin 33. The hot pin 33 is held on the hot tube 30, for example by crimping.

The heat exchanger 20 according to the present invention extends parallel to the hot pin 33, i.e. perpendicular to the hot tube 30. Thus, the hot pin 32 extends between two adjacent heat exchangers 20. The first face of the hot pin 33 faces the first face 21 of the first device 20 and the second face of the hot pin 33 opposite the first face of the hot pin 33 Is positioned facing the second side (22) of the second device (20) adjacent to the first device. The same hot pin 33 thus comprises a first series of thermoelectric elements 15 located between a first side of the hot pin 33 and the first side 21 of the first device 20 and a hot pin 33 And a second set of thermoelectric elements 15 located between the second side of the first device 20 and the second side 22 of the second device 20 adjacent to the first device.

In other words, the first side 21 of the device 20 is located facing the first hot pin 33 and the first series of thermoelectric elements 15 is located between the first side 21 and the hot pin 33 . The second face 22 of the same device 20 is positioned facing another hot pin 33 adjacent to the first pin and the second series of thermoelectric elements 15 faces the second face 22 ) And the another hot pin (33). The heat exchange means 25 is located between the first side 21 and the second side 22, in particular for transferring the cooling energy of the low temperature fluid to the first side 21 and the second side 22 .

Thus, the device 20 and the hot pins 33 are alternately stacked.

Here, a layer of substrate 50 is provided between the first and second surfaces 21, 22 and the thermoelectric element 15. The substrate 50 accommodates, for example, the thermoelectric elements 15. The substrate 50 is comprised of an electrically insulating and thermally conductive material to distribute heat to the thermoelectric elements 15. [ The heat exchange of the first and second surfaces 21, 22 with the thermoelectric elements 15 is in particular via the substrate 50. The substrate 50 may include electric tracks connecting the thermoelectric elements 15 in series and / or in parallel. This substrate 50 may also be located between the hot pins 33 and the thermoelectric elements 15.

Wherein the heat exchanger 20 includes first and second pins 31, 32 in a heat exchange relationship with the cold fluid and thermoelectric elements 15. The first pin 31 includes a first face 21 of the device and a mating face that contacts the heat exchange means 25 and the second pin 32 includes a second face 22 of the device, Includes a facing surface that contacts the heat exchange means (25). The first and second fins 31, 32 are parallel to each other and parallel to the hot pin 33.

The heat exchanging means 25 is disposed between the first pin 31 and the second pin 32. The heat exchange means 25 includes a zone intended to contact the low temperature fluid and having a surface area which is much wider than the surface area of the first surface 21 and / or the second surface 22, in particular at least 5 times larger do. This zone is intended to disrupt the flow of cold fluid as it passes through the apparatus 20, in order to improve the heat exchange between the cold fluid and the apparatus 20.

The heat exchange means 25 here comprises an intervening element 40, and in particular several intervening elements 40. An intervening element 30, which is wave-like, i.e. including a corrugated portion, is arranged between the first and second faces 21, 22. In other words, the intervening elements here are disposed between the first and second fins 31, 32 and come into contact with the first and second fins 31, 32 through, for example, the peaks of their corrugations. The thermoelectric module 10 of the present invention is configured such that the low temperature fluid flow passes between the folds of the corrugated portion of the interposer element 40. More specifically, the intervening elements 40 are oriented so that the peaks of their corrugated portions extend in a direction orthogonal to the longitudinal axis extending direction of the tube 30 and the fins 31, 32, 33. The interposing element 40 is assembled to the first and second pins 31 and 32, for example by brazing.

According to the embodiment shown in Figures 2 and 3, the interposing element 40 comprises means 45 for disrupting fluid flow. This means 45 for disrupting the fluid flow comprises a louvres 46 provided at the fold and connecting the peaks of the corrugations. The louver 46 may be formed from one corrugated portion to another corrugated portion for the purpose of extending the path of the cold fluid and increasing the heat exchange with the intervening element 40, Slots that allow passage of the fluid flow.

The intervening elements 40 may be divided into two separate layers extending parallel to one another in the direction of the longitudinal axis D of the first and second faces 21,22. The first of the two layers is located at the inlet of the low temperature fluid into the device 20, while the second of the two layers is located at the outlet of the low temperature fluid from the device 20.

According to an exemplary embodiment (not shown) of the present invention, the heat exchange means 25 take the form of a " deflected " baffle and are arranged in the extending direction, for example on the first and second surfaces 21,22 Strips of wave-like material disposed parallel to each other in the longitudinal axis direction D of the wave-shaped material. The strips are offset from one another in an extending direction to provide a passage for the cold fluid from the corrugations of one of the strips to the corrugations of the adjacent strip. In this way, a deviation of the material is created between the two corrugations for the purpose of disrupting the cold fluid flow and thus improving the heat exchange.

According to an aspect of the present invention, the heat exchange apparatus 20 is configured to form a thermal screen 36 that protects the hot pins 33. In particular, the first and second pins 31 and 32 are configured to form the thermal shielding film 36 that protects the hot pins 33.

The first and second fins 31 and 32 include a peripheral edge 37 raised in the direction of the first and second faces 21 and 22, for example. The raised circumferential edge 37 of the first pin 31 of the first device 20 is positioned on the raised peripheral edge 37 of the second pin 32 of the second device 20 adjacent to the first device Facing one another, one of the raised peripheral edges 37 contacts and / or overlaps the other peripheral edge. This overlap prevents the low temperature fluid from coming into contact with the hot pin 33. The raised peripheral edges 37 guide the cool fluid towards the interior of the apparatus 20, i.e. between the first and second sides 21, 22, allowing the cool fluid to pass through the heat exchange means 25 . In other words, the raised peripheral edge 37 covers the edge of the hot pin 33.

Generally, a fin refers to an element having two opposing flat broad surfaces, much thinner in thickness than its width and length. Thus making, in their active aspect, a large area contact between the large surface and the thermoelectric element 15. [ The pins are made of, for example, aluminum and / or aluminum alloys.

Claims (15)

A thermoelectric module (10) comprising a thermoelectric element (15) that allows the generation of current in the presence of a temperature gradient, and a heat exchange device (20)
The heat exchanger comprises a first surface (21) in heat exchange relationship with a first series of thermoelectric elements (15), a second surface (22) in heat exchange relationship with a second series of thermoelectric elements (15) And means for exchanging heat with the fluid in a heat exchange relationship with the first and second surfaces (21, 22)
The thermoelectric module 10 includes a hot tube 30 and a hot pin 33 in a heat exchange relationship with the active surface of the hot tube 30 and the thermoelectric element 15
Thermoelectric module. The method according to claim 1,
The heat exchange means 25 includes a region intended to contact the fluid and having a surface area that is at least 5 times greater than the surface area of the first surface 21 or the second surface 22
Thermoelectric module. The method according to claim 1,
The heat exchange apparatus 20 includes a first fin 31 including the first face 21 and a second fin 32 including the second face 22
Thermoelectric module. The method of claim 3,
The first and second pins (31, 32)
Thermoelectric module. The method according to claim 3 or 4,
The heat exchange means (25) is arranged between the first fin (31) and the second fin (32)
Thermoelectric module. 5. The method according to any one of claims 1 to 4,
The heat exchange means 25 is intended to disrupt the fluid flow
Thermoelectric module. The method according to claim 6,
The heat exchange means (25) comprises an intervening element (40)
Thermoelectric module. 8. The method of claim 7,
The intervening element (40) comprises a corrugated portion
Thermoelectric module. 8. The method of claim 7,
The intervening element (40) comprises means (45) for disrupting fluid flow
Thermoelectric module. 10. The method of claim 9,
The means (45) for disrupting fluid flow comprises a louvres (46)
Thermoelectric module. 9. The method of claim 8,
The heat exchange means (25) comprise strips of wave-like material arranged parallel to one another in one extending direction,
The strips may be arranged so as to provide a passage for the fluid from the corrugation of one of the strips to the corrugation of the adjacent strip,
Thermoelectric module. delete The method according to claim 1,
The heat exchange device (20) is configured to form a thermal shielding film (36) for protecting the hot pins (33)
Thermoelectric module. 14. The method of claim 13,
The hot tube 30 passes through the first and second surfaces 21, 22 having a longitudinal axis D,
The thermoelectric module 10 includes two hot tubes 30 spaced apart from one another in the longitudinal direction of extension D and another two hot tubes 30 spaced apart in the longitudinal direction of extension D, Which includes separate heat exchange means 25,
Thermoelectric module. A thermoelectric module (10) comprising the thermoelectric module (10) according to any one of claims 1 to 4
heat transmitter.

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