WO2016062928A1 - Thermoelectric and thermal insulation device for an aircraft engine nacelle, nacelle and method of manufacture of the device - Google Patents

Abstract

The invention relates to a thermoelectric and thermal insulation device, to an aircraft engine nacelle incorporating same and to a method of manufacture thereof. This device (1) can be used in a wall of such a nacelle defined by internal and external faces and is able to have an annular section delimited by a hot face (6a) facing toward the internal face and by a cold face (6b) facing toward the external face, the device comprising: a thermally insulating and flexible structure (2a, 2b, 2c) between the hot and cold faces and able to extend circumferentially, and a thermoelectric module incorporated into the structure and including: • alternating p and n semiconductor units (3), and • electrical connection means (4a, 4b) which electrically connect said p and n units together in pairs. According to the invention, the device comprises a plurality of thermally conducting heat dissipating means (7a, 7b) coupled to said blocks and connecting said electrical connection means, which are able to be deformed so as to extend circumferentially, at the hot face and at the cold face.

Description

 THERMAL THERMAL THERMAL THERMAL DEVICE FOR AN AIRCRAFT ENGINE AC HEAD, NACELLE AND METHOD OF

 MANUFACTURE OF THE DEVICE

The present invention relates to a thermoelective and thermal insulation device that can be used in a wall of an aircraft engine nacelle, such a nacelle incorporating this device and a method for manufacturing the same. The invention is generally applicable to a thermally insulating structure capable of generating congratulation, especially not exclusively for a driving environment, for example for the thermal protection of a fixed lower structure wall of an aircraft (" inner fixed structure "in English or" IFS "for short).

 In a known manner, the generation of electricity by thermoelectric effect (which transforms a temperature difference into an electrical current) requires the presence of a thermoelectric module comprising semiconductor couples which are usually electrically connected by metal foils (or alternatively by plates, blocks or other forms of connections} and which each consist of two semiconductor blocks respectively of type p and N. The two blocks p and n of each pair and the other couples making up the module are electrically connected. In series, these pairs of semiconductor blocks connected by these metal sheets are mounted between and in contact with two rigid substrates (typically made of ceramic material), the assembly forming the thermoelectric module.

US-B2-7,785,811 discloses a thermally insulating structure surrounding a fluid conduit and integrating such thermoelectric modules distributed around the circumference of the conduit. Each module comprises a succession of semiconductor blocks p and n distributed and electrically connected to each other in the axial direction of the conduit by metal foils. Each module thus extends in the axial direction and is connected to the outer face of the duct by rigid ceramic plates in contact with a heat sink radially. internal which consists of a metal braid of polygonal cross-section covered on its inner face with a thermally conductive soft material in contact with the conduit,

 A major disadvantage of the annular device with axial thermoelectric modules disclosed by this document lies in the use of these non-deformable ceramic plates, which each receive the axial succession of the semiconductor blocks and which are mounted on the sides of this polygonal dissipator combined with this soft conductive material to fit the cylindrical surface of the conduit.

 Another disadvantage of this annular device lies in the high number of thermoelectric modules axiau required, and therefore in the relatively high manufacturing cost of the device for obtaining a given thermoelectric effect.

 An object of the present invention is to provide a thermoelectric and thermal insulation device usable in a generally tubular wall of an aircraft engine nacelle which overcomes these disadvantages, the device being able to have a cross section at least in part. annular portion delimited by a hot face turned towards the inside of the nacelle and by a cold face opposite the hot face and turned towards the outside of the nacelle, the device comprising:

a thermally insulating and flexible structure located between said hot face and said cold face and adapted to ^extend into a circumferential direction of said cross section, and

 at least one thermoelectric module which is integrated in said structure and which comprises:

 * alternating semiconductor blocks p and n, and

electrical connection means which electrically connect said p and n blocks two by two with each other,

For this purpose, a device of the invention comprises a plurality of thermally conductive heat dissipation means coupled to the blocks and connecting the electrical connection means, which are capable of being deformed to extend in the circumferential direction, the hot face and the cold face.

 It will be noted that the thermally insulating structure generates a temperature gradient between the hot inner face and the cold outer face of the device, and that the thermoelectric modulus (s) directly integrated into the structure use the gradient due to this thermal insulation to generate electricity.

 It will also be noted that the insulating structure is flexible enough to be deforming in multiple directions, advantageously including the circumferential direction (as well as other directions) around its nacelle wall, and that the integration of the semiconductor blocks p and n distributed in this direction does not penalize the flexibility of the device while being relatively simple to obtain compared to the device presented in the aforementioned document.

According to another feature of the invention, said plurality of heat dissipation means can be superimposed spaced on and under said semiconductor blocks, which are then able to be distributed in the circumferential direction to form said at least one module. which is annular at least in part ^of said cross-section years.

 It will be noted that this generally annular geometry of each thermoelectric module according to the invention with p- and circumferentially spaced blocks in the nacelle wall differs from the axial geometry of each of the thermoelectric modules used in the abovementioned document.

 According to another preferred feature of the invention, said heat dissipation means may comprise:

 a first series of regularly spaced heat sinks which receive a first series of said electrical connection means and which are mounted between and in contact with respective first faces of said semiconductor biocides and said hot face, and

~ a second series of heat sinks which are regularly spaced opposite the dissipators of said first series, which receive a second series of said electrical connection means and which are mounted between and in contact with respective second faces of said biocs and against said cold face.

 Advantageously, said first series of dissipators may be formed of first pads each having a first contact surface with a said semiconductor block of area substantially equal to that of a said first face of said block, and said second series of heat sinks may be formed of second pads each having a second contact surface with a said area block substantially equal to that of a said second face of said block.

 Even more advantageously, said first pads and / or second pads may be polyhedral (for example substantially in the form of a rectangular, square or trapezoidal straight prism flared while moving away from said semiconductor biocides, it being specified that other shapes for example cylindrical are usable), and said blocks can be polyhedral sensibtement shaped right prism with rectangular or square base,

 According to another preferred feature of the invention, said first series of electrical connection means and said second series of electrical connection means may be formed of wires, cables, films, sheets or ribbons (for example applied alternately above said first faces and below said second faces of said semiconductor blocks) which may each comprise:

 a metal core and an electrically and thermally insulating coating casing, and

 two ends respectively housed in two so-called heat sinks.

It should be noted that these single wires, cables, films, sheets or ribbons which can thus form by themselves the electrical connection means according to the invention advantageously have a solid structure {Le. compact, not perforated) and not extensible or retractable. Alternatively, can also use extensible and retractable electrical connection means, such as springs or flexible wires, for example.

 Preferably, said coating envelope is of monolayer or multi-layer type, which may comprise in the latter case at least one organic layer based on a reinforced thermoplastic polymer and at least one inorganic layer opiminally reinforced with glass fibers.

 Advantageously, the heat dissipating diodes, for example aluminum, may each be integral with a said semiconductor block in an adherent interface preferably obtained by heating, bonding, welding, brazing or metalizing (eg by a process of electroplating, physical or chemical vapor deposition). In other words, gold can achieve this membership by any known means used in the industry.

 According to another characteristic of the invention, said thermally insulating and flexible structure may comprise at least two superposed mattresses which consist of thermally insulating materials for example based on a microporous silica and which comprise first perforations receiving said semiconductor blocks and second perforations receiving said heat dissipating means, said electrical connection means being able to be arranged out of said mattresses, such that spaced apart stacks of said blocks and said heat dissipating means are formed within said structure.

 According to another characteristic of the invention, the device may furthermore comprise a first flexible metal envelope defining said hot face and a second flexible metal envelope defining said cold face, the device advantageously being devoid of any rigid substrate, for example ceramic, on it and below said electrical connection means,

It will be noted that the integration according to the invention of at least one thermoelectric module in the thermally insulating structure is direct and simple to implement via the use of these metal envelopes which does not penalize the flexibility of the entire device, including the fact that we do without the rigid substrates required in the aforementioned document.

 An aircraft engine nacelle according to the invention, its nacelle comprising a generally tubular wall defined by a radially inner face and a radially outer face, is such that the wall incorporates at a distance from the inner and outer faces a thermoelectric device and a thermal insulation as defined above and said cross section is at least partly annular, the hot face of the device is preferably located in close proximity to the inner face of its wall.

 It will be appreciated that this device is advantageously incorporated in said wall axially towards the rear of the engine turbine, for example, although other areas are usable.

 A manufacturing method according to the invention of a device as defined above essentially comprises the following steps;

 a) guiding, in perforations and / or free spaces in a first portion of the thermally insulating and flexible structure deposited in a guide comprising a plurality of partitions, each of said semiconductor blocks, a first series of means for electrical connection and a first series of heat dissipation means, to obtain a first part of the device wherein each of said blocks is superimposed on each of the heat dissipation means of said first series between a pair of said adjacent partitions,

 (b) removal of said guide,

 c) depositing on said first part of the device a second part of the thermally insulating and flexible structure, a second series of electrical connection means and a second series of heat dissipation means, to obtain said structure in each of the heat dissipation means of the second series is superimposed on each of said blocks so as to obtain stacks spaced apart from said blocks and said heat dissipation means within the structure, then

d) assembling a first flexible metal envelope defining said hot face on the first series of connection means and on the first series of heat dissipation means, and a second flexible metal envelope defining said cold face on the second series of electrical connection means and on the second series of heat dissipation means, to obtain the device .

 According to a preferred embodiment of the invention, the electrical connection means of said first series and said second series have ends respectively inserted into the heat dissipation means of said first series and said second series, each of these ends being secured to a said means of heat dissipation corresponding preferably by heating, gluing or brazing.

 Advantageously, it is possible to use:

 for said first part of said structure in step a), at least a first thermally insulating mat, and

 for said second part of said structure in step c), at least one second thermal insulating mattress,

 said at least one first mat and said at least one second mat being for example each having a microporous silica base and possibly comprising first perforations receiving said semiconductor blocks and second perforations receiving said heat dissipating means, said connecting means electric can be arranged outside said at least a first mattress and out of said second mattress.

 Even more advantageously, it is possible to use for said first part of said structure in step a) two first thermally insulating superimposed mattresses, such that said structure comprises three thermally insulating mattresses superimposed and separated by said spaced stacks.

According to another characteristic of the invention, the method further comprises a step of deforming said device to give it a cross section that can be annular (totally or partially) or another geometry. This deformation or shaping step can be carried out before assembly or before the step of joining said hot and cold faces. The aforementioned features of the present invention, as well as others, will be better understood on reading the following description of several exemplary embodiments of the invention, given for illustrative and nonlimiting purposes in relation to the accompanying drawings, among which :

Figure 1 is an axial sectional view of a motor-free ^aircraft showing replacement of the nacelle of the engine incorporating a device according to the invention,

 FIG. 1a is a medallion in axial section showing a detail of the nacelle of FIG. 1 incorporating this device,

 FIG. 2 is a partial diagrammatic cross-sectional view of an exemplary device according to the invention prior to its deformation, showing the semiconductor blocks of a module and the heat sinks with which they are provided,

 FIG. 3 is a partial diagrammatic cross-sectional view of a device according to the invention such as that of FIG. 2, twisted to give it an annular or other transverse cross-section,

 FIG. 4 is a diagrammatic cross-sectional view of a guide that can be used to form a stack according to an example of the invention of a semiconductor block and two heat sinks in a thermally insulating structure,

 FIG. 4A is a schematic cross-sectional view of another guide that can be used to form several stacks such as that of FIG. 4 in the thermally insulating structure,

 FIG. 5 is a diagrammatic cross-sectional view of a guide similar to that of FIG. 4 showing the result, according to an example of the invention, of a first step of assembling a semiconductor block and a first dissipator; thermal within a first part of the structure,

FIG. 6 is a view from above of the guide of FIG. 5, FIG. 7 is a partial schematic cross-sectional view showing the assembly of FIG. 5 after removal of the guide,

Figure 8 is a partial schematic cross-sectional view showing the result ^of a second step of assembling a second heat sink on the first part of the structure,

 FIG. 9 is a partial cross-sectional schematic view of a preferred embodiment of the invention corresponding to a variant of that of FIGS. 2 to 8 and showing the electrical connection means coupled to three semiconductor blocks within a thermally insulating structure, and

 FIG. 10 is a partial schematic cross-sectional view of an enlargement of a central zone of FIG. 9 detailing an example of attachment according to the invention of connection means to the first and second heat sinks, in connection with one of these thermoelectric blocks.

 As illustrated in FIG. 1, a thermoelectric and thermal insulation device 1 according to the invention is advantageously intended to equip an aircraft engine 10, while being housed in a part of the generally tubular wall 11 of a nacelle 12 of the motor 10, which can comprise, in a known manner:

 a cold part successively defined by an air intake section 13 and a compression stage 14, and

 a hot part successively defined by a combustion chamber combustion chamber 15, a turbine 16 and a final exhaust section 17.

The wall 11 of the nacelle 12 incorporating the device 1 is located behind the turbine 18, in a zone in this frustoconical example which is located axially between it and the exhaust section 17, and this wall 11 which forms the fairing of the nacelle 12 is partitioned in the example of Figure 1. The device 1 thus extends according to a generally tubular geometry (ie annular in cross section) between the radially inner faces 1a and external 11b of the wall 11 (as shown in FIG. This device 1 extends in close proximity to this internal face 11a). These inner faces 11a and 11b outer faces may have a temperature gradient Tcr ^' ! more than 500 ° C (with for example maximum temperatures Te of 500 ° C and minimum TF of -75 ° C respectively inside and outside the device 1, the maximum temperatures T _F and minimum T _C usually encountered in operation being respectively of the order of 385 ° C and 100 ° C).

 As illustrated in FIGS. 2 and 3, the device 1 essentially comprises a thermally insulating thermal insulation structure 2 of thermal protection, for example based on three superimposed inorganic mattresses 2a, 2b, 2c (eg made of a microporous material, for example based on silica cast in a mold), in which structure 2 are integrated semiconductor blocks 3 of type n and p electrically connected in series by metal connectors 4a and 4b (for example having a copper core, as will be detailed hereinafter with reference to FIGS. 6 and 10) to form a thermoelectric module 5. Connectors 4a and 4b are connected as well as blocks 3 to hot faces 6a and cold 6b of device 1 via two respective series of heat sinks 7a and 7b (which are for example aluminum).

 Flexible plates 6a and 6b, for example, made of steel, which respectively form in operation these hot (internal) and cold (external) faces of the device 1 between the inner and outer faces 11a and 11b of the wall 11, are applied on both sides. Another of the structure 2, Note that the sheets 6a and 6b are flexible and easily deformable, unlike the rigid ceramic substrates used in the prior art, so that the entire device 1 remains flexible as visible in the FIG. 3 to follow the annular contour of the wall 11 of the nacelle 12.

It is possible to assemble a device 1 according to the invention, for example as illustrated in FIGS. 4 to 8, by using a guide 30, 30 ^* comprising edge walls 31 and 32 and partitions 33 and 34 which are regularly spaced between the walls 31 and 32 and which have successively different heights alternate to allow a good positioning of the semiconductor blocks 3 and their electrical connection by the metal tracks forming the connectors 4a and 4b (with, in the example of FIGS. 4a and 4A, high partitions 33 of maximum height which are equal to that common to the edge walls 31 , 32 and the first two mattresses 2a and 2b superimposed, and low partitions 34 of height reduced by half which corresponds to that of the first mat 2a),

 The guide 30 of FIG. 4 presents a single unit representative pattern 3 to be assembled in connection with the connectors 4a and 4b and the dissipaters 7a and 7b, whereas the complete guide 30 'of FIG. more complex tooling to use to assemble a multitude of blocks 3 each provided connectors 4a and 4b and dissipators 7a and 7b within the insulating structure 2.

 As can be seen in FIG. 5, in a first assembly step, each semiconductor block 3 is positioned in a free space arranged at the sound of the first and second stacked mattresses 2a and 2b, between an upper partition 33 and a low partition 34 and on a first lower heat sink 7a with which the block 3 is secured (by brazing in this example, see the solder 3a) on either side of a first lower connector 4a inserted between the mattresses 2a and 2b. For this purpose, the mattresses 2a and 25 are pierced before perforations 2d receiving blocks 3 and perforations 2e receiving your dissipators 7a which they are provided.

 Each connector 4a is thus fixed on the upper face of the dissipator 7a and under the lower face of the block 3. The dissipator 7a has a polyhedral shape which is advantageously prismatic rectangular or square base (i.e. parallelepiped or cubic).

 The guide 30 is then removed to obtain the assembly visible in FIG. 7, in which Intermediate stacks 7a, 4a, 3 are formed within the two mattresses 2a and 2b.

Note that what comes from ^! FIG. 4, 4A, 5, 6 and 7 is only one example of implementation of the method of manufacturing a device according to the invention, and that it is alternatively possible to proceed with assembling without a guide or with a guide remaining in place following the assembly, provided that the latter guide has a thermal conductivity identical or similar to that of the corresponding insulation blanket.

 As can be seen in FIG. 8, which shows the result of a subsequent assembly step, in a free space provided in the third mattress 2c deposited on the mattresses 2a and 2b, a second upper connector 4b is placed on its face. upper of each block 3 and under the lower face of a second upper heat sink 7b (which is in this example joined by brazing with the block 3 on either side of the connector 4b, see again the solder 3a), so as to thermally connect by conduction each block 3 to the sheets 6a and 8b via the dissipaters 7a and 7b. For this purpose, the mattress 2c is previously pierced with perforations 2e receiving the dissipators 7b.

 In the example of FIG. 8, the second upper dissipator 7b has a flared trapezoidal base (isosceles trapezium) prismatic shape towards the sheet 6b, it being specified that this dissipator 7b could alternatively be identical to the dissipator 7a.

 After deformation, for example an annular device 1 thus obtained and integration of the latter to the annular wall 11 of the nacelle 12, is obtained as partially illustrated in Figure 3 radial stacks S respectively formed semiconductor biocs 3 which are provided with heatsinks 7a and 7b and which are connected two by two to each other by the first and second connectors 4a and 4b being separated from each other by the three mattresses 2a, 2b, 2c.

The device 1 according to the preferred embodiment of Figures S and 10 differs essentially from that which has just been described with reference to Figures 4 to 8, in that the first lower connectors 4a and the upper second connectors 4b have their ends 8a, 7b respectively, spaced apart from the lower and upper faces of the blocks 3. These are for example secured by heating and not by brazing with the lower dissipaters 7a and 7b upper, at a lower temperature or equal to 250 ° C (whereas for soldering the required temperature must be at least 500 X). In general, it can secure the blocks 3 by a bonding technique that requires cooking of temperature below 300 ° C and which allows to obtain an assembly resistant to 500 ^e C and up to 550 ^e 'C,

 As can be seen in FIG. 10, the connectors 4a and 4b according to this preferred embodiment each comprise a metal core 9b, for example made of copper (each end 9a of connectors 4a, 4b which is housed in a dissipator 7a, 7b being constituted by this core 9b) and a monolayer or multilayer coating envelope 9c which is electrically and thermally insulating. The envelope 9b may comprise, if it is multilayer, an organic layer based on a reinforced thermoplastic polymer, an inorganic layer and optionally a layer of glass fibers, without limitation.

Claims

R .EVENDICATiONS 1) Thermoelectric and thermal insulation device (1) usable in a nacelle (12) of aircraft engine {10}, the device being able to have a cross section at least partly annular delimited by a hot face (8a) turned towards the inside of the nacelle and by a cold face (8b) opposite to said hot face and turned towards the outside of the nacelle, the device comprising:  a thermally insulating and flexible structure (2) located between said hot face and said cold face and able to extend in a circumferential direction of said cross section, and  at least one thermoelectric module (5) which is integrated with said structure and which comprises;  alternating semiconductor blocks (3) p and n, and electrical connection means (4a, 4b) which electrically connect said p and n blocks in pairs to one another, characterized in that the device comprises a plurality of thermally conductive heat dissipating means (7a, 7b) coupled to said blocks and connecting said electrical connection means, which are adapted to be deformed to extend in said circumferential direction, to said hot face and said cold face. 2) Device (1) according to claim 1, characterized in that said plurality of heat dissipation means (7a, 7b) are superimposed spaced on and under said semiconductor blocks (3), which are capable of being distributed in said circumferential direction to form said at least one module (5) which is at least partly annular in said cross section. 3) Device (1) according to claim 1 or 2, characterized in that said heat dissipation means (7a, 7b) comprise: a first series of regularly spaced heat sinks (7a) which receive a first series of said electrical connection means (4a) and which are mounted between and in contact with respective first faces of said semiconductor blocks (3) and said hot face; (6a), and  a second series of heat sinks (7b) which are regularly spaced opposite the dissipators (7a) of said first series, which receive a second series of said electrical connection means (4b) and which are mounted between and in contact with second faces respective of said blocks and against said cold face (6b). 4) Device (1) according to claim 3, characterized in that said first series of dissipators (7a) is formed of first pads each having a first contact surface with a said semiconductor block (3) of area substantially equal to that a said first face of said block, and in that said second series of dissipators (7b) is formed of second pads each having a second surface of contact with a said block (3) of area substantially equal to that of a said second face of said block. 5) Device (1) according to claim 4, characterized in that Sa said first pads (7a) and / or Sa said second pads (7b) are polyhedral, and in that said biocs are polyhedral substantially in the form of a right prism with a rectangular base or square. 6) Device (1) according to one of claims 3 to 5, characterized in that said first series of electrical connection means (4a) and said second series of electrical connection means (4b) are formed of wires, cables, films, sheets or ribbons that each include: a metal core (9b) and an electrically and thermally insulating coating casing (9c), and two ends (9a) respectively housed in two so-called heat sinks (7a, 7b), 7) Device (1) according to claim 6, characterized in that said coating casing (9c) is of monolayer or multilayer type, comprising in the case where it is multilayer at least one organic layer based on a thermoplastic polymer reinforced and at least one inorganic layer optionally reinforced with glass fibers. 8) Device (1) according to one of claims 3 to 7, characterized in that said heat sinks (7a and 7b) ₅ for example aluminum, are each integral with a said semiconductor block (3) in an adherent interface for example obtained by heating, gluing, welding, brazing or metallization. 9) Device (1) according to one of the preceding claims, characterized in that said thermally insulating and flexible structure (2) comprises at least two mattresses (2a, 2b, 2c) superimposed which consist of thermally insulating materials for example based on microporous silica and which comprise first perforations (2d) receiving said semiconductor blocks (3) and second perforations (2e) receiving said heat dissipating means (7a, 7b), said electrical connection means (4a, 4b) being arranged outside said mattresses, so that spaced apart stacks (8) of said blocks and said heat dissipating means are formed within said structure, 10) Device (1) according to one of the preceding claims, characterized in that the device further comprises a first flexible metal casing (8a) defining said hot face and a second ) flexible metal envelope (8b) defining said cold face, the device being devoid of any rigid substrate for example ceramic above and below said electrical connection means (4a, 4b), 11} An aircraft engine nacelle (12) having a generally tabular wall (11) defined by a radially inner face (11a) and a radially outer face (11b), characterized in that said wall incorporates at a distance said internal and external faces a thermoelectric device and thermal insulation (1) according to one of claims 1 to 10 and having said at least partly annular cross section, said hot face (8a) of the device being preferably located in the immediate vicinity of said face i dull of said wall, 12) A method of manufacturing a thermoelectric device and thermal insulation (1) according to one of claims 1 to 10, characterized in that it comprises the following steps:  a) guiding, in perforations (2d, 2e) and / or free spaces in a first portion (2a, 2b) of said thermally insulating and flexible structure (2) deposited in a guide (30, 30 ') having a plurality of partitions (33, 34), each of said semiconductor blocks (3), a first series of said electrical connection means (4a) and a first series of said heat dissipating means (7a), for obtaining a first part of said device in which each of said blocks is superimposed on each of the heat dissipation means of said first series between a pair of said adjacent partitions (33 and 34), b) removal of said guide, c) depositing on said first part of the device a second part (2c) of said thermally insulating and flexible structure, a second series of said electrical connection means (4b) and a second series of said heat dissipating means; (7b), to obtain said structure in which each of the heat dissipation means of the second series is superimposed on each of said blocks so as to obtain stacks (8) spaced from said blocks (3) and said heat dissipating means ( 7a, 7b) within said structure (2), then d) assembling a first flexible metal envelope (8a) defining said hot face on the first series of said electrical connection means (4a) and on the first series of said heat dissipating means (7a), and a second envelope metal hose (6b) defining said cold side to the second series of said electrical connection means (4b) and the second series of said heat dissipating means (? b) to obtain said device _* 13) The method of claim 12, characterized in that said electrical connection means of said first series (4a) and said second series (4b) have ends (9a) respectively connected to said heat dissipation means of said first series (7a) and said second series (7b), each of said ends being secured to a said heat dissipation means (7a, 7b) corresponding preferably by heating, gluing, welding, brazing or metalization. 14) Method according to claim 12 or 13, characterized in that the following is used:  for said first part of said structure (2) in step a), at least a first thermally insulating first mat (2a, 2b), and  for said second part of said structure in step c), at least a second heat-insulating second mat (2c), said at least one first mat and said at least one second mat being for example each based on a microporous silica and comprising first perforations (2d) receiving said semiconductor blocks (3) and second perforations (2e) receiving said means heat dissipation (7a, 7b), said electrical connection means (4a, 4b) being arranged out of dud t at least a first mattress and out of said second mattress. 15) Method according to claim 14, characterized in that one uses for said first part of said structure (2) in step a) two first mattresses (2a and 2b) t ermiquement insulating superimposed, so that said structure comprises three thermally insulating mattresses (2a, 2b, 2c) superimposed and separated by said spaced apart stacks (8). 16) Method according to one of claims 12 to 15, characterized in that it further comprises a deformation step dud it device (1) to confer said cross section for example at least partly annular.