EP3469248A2

EP3469248A2 - Thermal bridge-free assembly

Info

Publication number: EP3469248A2
Application number: EP17735202.8A
Authority: EP
Inventors: Fabrice Chopard; Boris Chauvet; Cédric HUILLET
Original assignee: Hutchinson SA
Current assignee: Hutchinson SA
Priority date: 2016-06-10
Filing date: 2017-06-09
Publication date: 2019-04-17
Also published as: WO2017212200A3; US20190137036A1; FR3052534A1; WO2017212200A2; FR3052534B1; CN109563965B; JP6968831B2; CN109563965A; KR20190017038A; KR102341101B1; WO2017212200A4; JP2019520274A

Abstract

Disclosed is a thermally insulating assembly that is placed between a first volume (7) and a second volume (9) which is to be thermally managed in relation to the first volume, said assembly (10) comprising a series of parts (1) which create thermal bridges between each other and which: - are arranged in a plurality of layers (13a, 13b) along a thickness and a direction running through the first and second volumes; and/or - are offset in pairs transversely from one layer to the adjoining layer transversely to said thickness and direction; and/or - mutually engage each other at least in pairs transversely to said direction and thickness in order to force a thermal flow (F), which substantially follows said direction along the thermal bridges, to change directions so as to flow towards an isotherm (11).

Description

CONTRESSED THERMAL BRIDGE ASSEMBLY

The present invention relates to the field of thermal management.

Particularly concerned are a thermal insulation member and a heat insulating assembly interposed between a first volume and a second volume to be thermally controlled vis-à-vis the first volume, the assembly comprising a series of aforementioned parts assembled or disposed at the way of elementary bricks.

In the art there are thermally insulating parts in a controlled atmosphere (especially vacuum insulated part, VIP or VIP vacuum insulated panel).

By "PIV" or PIV (Vacuum Insulation Panel; VIP in English), is meant in the present text a structure where an enclosure is under "controlled atmosphere", that is to say is filled by a gas having a thermal conductivity lower than that of the ambient air (26mW / mK), ie under a pressure of less than 10 ⁵ Pa. A pressure between 10 ^-2 Pa and 10 ⁴ Pa in the enclosure created may in particular be suitable.

US 2003/002134 proposes a thermal insulation assembly comprising a series of thermal insulation parts establishing between them, at least for some, thermal bridges and which are:

disposed in several layers according to a thickness that each piece has and which varies along a length that said piece has transversely to said thickness, and along which each said piece has externally at least one projection adjacent to a hollow,

- Shifted and nested two by two transversely, a said layer to the adjacent layer, so that a piece of a layer of a projection is engaged in a hollow part of the layer adjacent, thus forcing a heat flow, generally established along the thickness, along the thermal bridges, to change direction to an isotherm and then to be blocked by an orientation locally substantially against the direction.

A problem remains however in connection with the effectiveness of these parts and sets of the aforementioned type that they allow, or could allow, to achieve.

Indeed, when such sets are put in place, thermal bridging problems between parts continue to arise.

However, this can be very penalizing for the thermal conductivity of these sets, for example when a set of such parts is interposed between a first volume (which may be the outside atmosphere) and a second volume to be thermally controlled vis-à-vis of the first volume, with temperature differences between the volumes that may be greater than 50 ° C, or even 100 ° C.

Failure to sufficiently deal with these thermal bridge problems can result in incomplete thermal management between volumes.

In addition, there is a problem with how to make large insulating structures or large insulating volumes.

In circumstances where thermal insulation must be ensured at low temperatures (below -100 or -150 ° C, where the air gases liquefy), it may also be desired to avoid local cold spots that would cause frost certain parts, at least on one side of the insulating walls (especially on the outside).

A solution defined here proposes that the thermal insulation assembly presented above is furthermore such:

said assembly is interposed between a first volume and a second volume to be thermally managed with respect to the first volume, - said layers are arranged in a direction (D) passing through the first and second volumes, the thicknesses and length (s) being respectively defined in said direction and transverse thereto, and

that on at least one of the layers, at the longitudinal ends of two adjacent and successive parts of the layer where these two parts each have a said projection, said thermal bridges between said two parts of the layer are established:

- over the entire thickness of the projections,

- Next, on the adjacent layer, a longitudinally intermediate portion of a hollow of a said transversely offset piece.

Thus, this thermal insulation assembly:

- not only will be formed of a series of elementary bricks each insulating thermal, assembled, ensuring ease of assembly and appreciable modularity to achieve various shapes,

- but it will significantly limit the importance of the flow reaching this opposite edge.

Figure 24 and the accompanying explanation provide details of a "change of direction to an isotherm".

And to further promote both modularity and the fight against thermal losses, it is also proposed: - a projection of said piece of a layer is engaged in a said hollow of a single said part of the adjacent layer,

and / or that at longitudinal ends of two adjacent and successive parts of a layer, said adjacent projections of these two parts are engaged together in a said hollow of a single said part of the adjacent layer. By this (s) engagement (s) in a single hollow of a single said part of the adjacent layer, it will block optimally the passage of flows to control.

Favorably, to limit the volumes or thicknesses of insulation and / or increase the internal space available in the thermally managed part, or even to limit the weight of the installation created, it is proposed that said insulating parts or bricks are individually PIV structure .

And, to promote modularity, with handy parts while being efficient in terms of thermal management, it has been found advisable that, in said direction changed (direction 100 figure 24) or blocking the flow created, a piece transversely covers an adjacent piece over a distance (R) less than or equal to 500 mm, and / or that the elementary surface of each said piece is less than or equal to 2.5 m ² .

To create the changes of direction of a thermal flow towards an isotherm, it is proposed that at least some of said pieces or bricks comprise an envelope and at least one thermal insulating element that the envelope surrounds at least locally, the envelope and the thermal insulating element each having several successive elbows externally defining projections adjacent to recesses.

These bent shapes will necessarily force said thermal flows to oblique several times.

To promote an orientation of said transverse isotherm in the directions D and e, the "change of direction" will a priori be made at right angles or at least result in a reorientation perpendicular to these directions D and e (direction 100 figure 24).

With respect to these changes of direction, at least the envelope of the part will favorably present at least one T-section, or Π or H or I, or, in one direction, a combination of several of these sections or a repetition of at least one of them.

In order to take into account thermal losses in the corners, or at the end of an insulated piece, it is furthermore proposed that said series of pieces define a panel having a slice which will have, on at least two sides, projections (or recessed) of said parts each engaged with a complementary grooved (or protruding) shape of an end block comprising at least one thermal insulating element. The blind grooves of the blocks will form bag bottoms for the paths of the thermal bridges.

If necessary, the invention will be better understood and other characteristics, details and advantages thereof will become apparent upon reading the following description, given by way of non-limiting example and with reference to the accompanying drawings, in which: which :

FIG. 1 is a diagram of the part according to the invention, FIG. 2 is the section along the plane II-II;

FIG. 3 is an exploded view, before assembly, of the embodiment of FIGS. 1, 2, containing exclusively thermal insulation,

FIG. 4 is an exploded view of an alternative, before assembly,

FIG. 5 shows in perspective a partial assembly in a set of parts as in FIGS. 1, 2, 3, in two successive states, as well as FIG. 7,

FIG. 6 schematizes an alternative embodiment of such an assembly,

FIGS. 8, 9 schematize two horizontal sections of insulating housings constructed with sets of parts of the aforementioned types,

FIG. 10 is an exploded view of a housing constructed with parts according to the invention, FIG. 11 shows a panel of this housing constructed with such assembled parts,

FIGS. 12, 13, 14 diagrammatically show three types of end blocks for such a panel,

FIG. 15 is an internal view of the housing of FIG. 12 assembled,

FIG. 16 schematizes in vertical cross-section a hull of a ship with a wall provided with the aforementioned insulating elementary bricks, for example in a transport application for chemical product, LNG or LPG, and

- Figure 17 helps to detail this "change of direction of flow to an isotherm".

It is at this stage specified that, in this application:

- "piece" means a piece, an element or an elementary brick, plane (e) or not (in three dimensions), of any shape;

- "transverse" and "transversely" has direction oriented transversely, not necessarily perpendicular, with respect to an axis or a reference direction, here the thickness e and the direction D; a perpendicularity or an angle less than 30 ° with respect to this perpendicular is, however, advisable;

- "depression" has a pressure of less than 10 ⁵ Pa;

An object of the present invention is thus to create a part 1 comprising a casing 3 having at least 5 bent elbows 5. Once a succession of such parts interposed, as shown diagrammatically in FIGS. 6 to 8 or 16, between a first volume 7 and a second volume 9 to be thermally controlled vis-à-vis the first volume, according to a thickness (e) parts 1 and a direction D through the first and second volumes (see Figure 8 example), a thermal flow F generally established following said direction to follow, along thermal bridges established between the parts, will be forced to redirect to an isotherm 11. Such an isotherm will typically be established between two stages of parts 1 (FIG. 16 for example), or after having passed an elbow (change of direction on the part (s) concerned) as in a single stage example. shown in Figure 11.

Thus, as in the examples of FIGS. 6-8, the pieces 1 may thus have been arranged, between the volumes 7, 9, each with its thickness parallel to the direction D and so that, transversely to this direction and this thickness, the parts 1 are shifted two by two transversely of a said layer to the adjacent layer, being arranged on several layers, such as 13a, 13b, along these thickness e and direction D.

The first volume 7 may be the outside environment and the second 9, an interior volume, in a vehicle.

The arrangement of the parts 1 may be staggered, or half-inconclusive, if there are only two layers, such as 13a, 13b Figure 9.

An alternative or complementary solution shown in the example of FIG. 10 provides that, with respect to the thickness e and the direction D, the parts 1 are nested at least two by two, transversely (perpendicularly in the example) to said direction. and thickness, at the marked areas 15a, 15b.

Hence the preferred examples of the abovementioned sections and illustrated envelopes 3 and insulators 25: T (parts 1 a, Figure 16), or Π (Figure 7) or H (Figure 9, in particular) or I (H tilted), this according to a direction, a combination of several of these sections or a repetition of at least one of them.

Thus, for example the section H (perpendicular to the thickness) of the parts of the embodiment of Figure 6 can be built with two T abutting by the free end of their vertical bar.

If two by two offsets between parts 1, transversely to said thickness e and direction D, of a said layer to the adjacent layer are relevant as in the embodiment and mounting of Figure 6 (see serpentine path), nesting will further increase the efficiency of the expected thermal management, particularly in terms of insulation, and allow that the pieces stand and lock each other.

In this respect, it should be noted that in the invention:

on at least one of the layers, at longitudinal ends of two adjacent and successive parts of the layer where these two parts each have a said projection 21, such that in 15a, 15b, FIG. 8, the thermal bridges, such as 16a , 16b figure 8, between said two parts of the layer (such as 16a, 16b with respect to the thermal bridge 16a), are established:

- over the entire thickness of the projections 21,

facing, on the adjacent layer, a longitudinally intermediate portion, such as 23b, of a recess 23 of a said transversely offset piece (in the direction D and in the thickness e).

It may moreover even more preferably that a said protrusion of a said part of a layer is engaged in a hollow of a single said part of the adjacent layer, as is for example the projection 21 has in the recess 23a defined by the longitudinally intermediate portion 23b thinner (thickness e2 <e1) of the single piece (therefore single) 1 b.

And even more prefer that, always at longitudinal ends of two adjacent and successive parts 1 of a layer, said adjacent projections, such as 15b1, 15b2, figure 8, of these two parts are engaged together in a said hollow 23c of the longitudinally intermediate portion of a single said piece 1 of the adjacent layer.

Thus, for example, the local thermal flux F in the direction D passing through the thermal bridge 16c (FIG. 8) will not only be deflected but blocked over a great length; see F1, F2. In order to clearly mark what is here a bent form 5 of part 1, at 50 such bends have been identified in different figures. On the envelopes 3, each bend 5 is a priori defined by a fold of a plate or a sheet, such as a metal foil. The term "metal" covers alloys.

It is recommended, according to said thickness e and direction D: - that the elbows 5,50 define on each piece at least said first zone 21 externally projecting with respect to a second zone 23 externally recessed,

and that the parts 1 are arranged so that at least some of the first zones 21 are directed towards the second volume 9.

As can also be seen in particular FIGS. 2-4, each piece of thermal insulation comprises an envelope 3 and at least one thermal insulating element 25 that the envelope surrounds at least locally.

In fact, FIGS. 1 -6 in particular help, in groups, to show that each envelope 3 has two opposite faces defined respectively by these first and second walls 31a, 31b, each being in one or more parts, at least first wall 31a having at least one said bend 33 defining the corresponding bend 5.50; see figures 3,4 in particular.

To form the or each elbow, fasten together at 45, typically at the location of welds (including solderings), two folded edges 39 of two elementary plates arranged substantially in the extension of one another (see in particular FIGS. , 2) will ensure a rapid, reliable, industrial manufacture of the walls 31 a, 31 b, compatible with a controlled atmosphere of the final envelope obtained.

The first and second walls 31a, 31b will be fixed together, as indicated 37, for example FIG. Part 1 (envelope + core material 25), will have a favorable thermal conductivity of less than 100mW / mK at 20 ° C and in an atmospheric pressure environment.

The first and second walls 31a, 31b can be made from a plurality of elementary plates, such as those 43a-43d in FIG. 1, two opposite edges of which are folded at 39 in the same direction.

To thermally manage the second volume 9 vis-à-vis the first volume 7, according to the thickness (e) parts 1 and therefore a direction D passing through these first and second volumes, we will interpose, between these volumes 7 and 9, a thermal insulating assembly 10 thus comprising a series of parts 1.

This can be seen better in FIGS. 8, 9, which should therefore be considered as horizontal sections that could be made in the plane A of FIG. 5, with different embodiments of the parts 1.

Thus, for example, to construct a parallelepipedal casing 50 completely surrounding the central volume 7, one or more layers will be disposed on four successive faces (here three 13a, 13b, 13c) of parts 1 which are in the example nested on each of these elements. 10 at an angle 51, two adjacent assemblies 10 are connected by a thermal insulating angle pillar 53 which may also be of PIV type, such as a metal sheet folded around a thermal insulating element 25 itself. standing like a block and that such envelope will surround tightly.

The modularity of the elementary parts 1 will make it easy to manufacture these corner zones, for example as illustrated. The two remaining faces, top and bottom, will be able to receive two lids, also thermal insulators and which could each be formed as one of the precipitated faces. Thus, on all sides, on each face, the effect forcing any heat flow F (Generally established in said local direction D) to at least change direction to isotherm 11, between parts 1, will be reached.

To detail this, we see Figure 17 that a heat flow F has therefore been created:

from an outer face (bordering a volume, eg at 25 ° C.) of a set of heat-insulating pieces 1 assembled edge to edge, as illustrated,

- To the inner face of said assembly which borders an interior volume whose temperature at -195 ° C is to preserve.

Thus it is seen that the flow F established in the direction D, along a thermal bridge between two adjacent parts 1 has changed direction (F1 / F2) to the transverse interface between these parts, 10a, where the interface has changed direction itself. On the parts 1 between which the flow F has just crept in it has been schematized some isotherms 11a, 11b, 11c. These are inflected on the axial interface (direction D) such as 110c for that identified 11 c, because the temperature is hotter than on either side, within the insulating parts 1. At 10a, where the flux F thus splits into F1 / F2, the isotherm 11 is generally against itself transverse to the direction D, since it is located at this transverse interface.

As shown diagrammatically in FIGS. 5 and 9, an assembly 10 of parts 1 will favorably be arranged, for the sake of ease of handling, or even of metal protection (precaution against piercing of the envelopes 3), between two lateral plates 55, 57, which may be flat. , erected in the general plane B perpendicular to A and said thickness (e) and direction D, this if necessary on each side.

In terms of shape, it is possible to perform a priori any shape, for example around a tube 59 as this is Figure 9 or the elementary parts 1 are curved or curved individually, here in C, in addition to their sectional shape, here also in Π (or U), to follow the circumference of the tube 59 here cylindrical axis 61. Flux F, from or to volume 7, will then be substantially radial.

The tube 59 could be closed on one side by a bottom and on the other by a cover, each also provided with a thermal insulator, for example an assembly 1 formed of elementary bricks 10 in the appropriate version, of for example to form a tank that could be cylindrical.

In all the cases considered, the thermal insulation 25 may be a foam or a fibrous material (such as glass wool or rock wool).

In Figures 10 to 15, we now see an example of housing 50 or elements belonging to it and therefore constructed with parts according to the invention.

Thus, it is understood with these views that a series of pieces 1 assembled in puzzle as previously explained, those of Figures 4-6 in the example, defines a generally planar panel 67 having a slice 69 (Figure 11) which presents, on at least two sides (here on its four sides, the panel is rectangular), projecting parts 71 of said parts 1 to engage each with a grooved complementary shape 73 of an end block 75a, 75b or 75c comprising , typically incorporating at least one thermal insulation element (or material) 76.

Conversely, the relevant parts 1 of the panel 67 could form grooves and the complementary shapes of the end blocks 75a, 75b, 75c be protruding.

In this case, there is an end block 75a, 75b or 75c facing each side of the edge of each panel 67. And some at least panels 67, and therefore end blocks, may not be planar.

In the example in FIG. 11, on two opposite sides (here at the top and at the bottom), the parts 1, with I-section (or H tilted), of the central layer 13b project, like a tip of variable section, by compared to those of the other two layers 13a, 13c located on either side. Ditto for the single tongue shape of the two projections 71 on the other two sides (here left and right) formed here by the central core 111 of the I-shaped two parts 1 central end side.

In fact, in the example, the section of these two parts 1 central end ends has been truncated at T.

Given these different shapes, in the example, according to the portion portions 69 considered, two types of end blocks 75a, 75b are required, with grooves 73.

The end blocks 75a, 75b, 75c, forming thermal insulation as the panels, serve to block the path of the thermal bridges. In fact, their unitary block construction, without path separation for the thermal bridges, with bottoms of blocking grooves 73 where the paths of the thermal bridges of the panels end up, in the plane of the panels, reinforce the expected thermal insulation.

Figure 10 shows the relative locations of end blocks 75a, 75b, 75c and panels 67 at the respective numbers of 12 and 6, for the parallelepipedal housing shown.

On each end block 75a (FIG. 12) provided between two sides 71 with projections I (or H tilted) of panels 67 arranged transversely, the grooves 73 of the two adjacent longitudinal faces provided with them are identical and complementary to these I-sections (or H tilted) of the layer 13b, top and bottom, parts 1 of the panel 67 concerned.

On each end block 75c (FIG. 14) provided between two center-core sides 111 of panels 67 arranged transversely, the grooves 73 of the two adjacent longitudinal faces which are provided with them are identical and complementary to these central webs 111 of the central layers 13b. concerned.

On each end block 75b (FIG. 13), hybrid between the end blocks 75a, 75c, provided between a central core side 111 and a projecting side 71 I (or H tilted) side of the transverse panel 67. previous, the grooves 73 of the two adjacent longitudinal faces which are provided are identical and complementary to these central cores 111 and 71 projections I (or H tilted), respectively.

Thus, the end blocks 75a, 75b, 75c form multi-part frames which frame the entire edge of each panel 67, while connecting and maintaining them in the corners of the housing 50, see in particular Figure 15.

Parallelepipedic, the end blocks may each have, on their other two faces, solid walls adapted to receive, internally and externally, the support of the side plates 55,57. Thus, each panel 67 can be clamped between these two side walls fixed with the end blocks.

Fixing with a glue layer 77 or screws for example is possible.

An application for all or part of the insulating assemblies 10 to elementary bricks 1 presented above may concern a wall 80 for limiting a tank 83 containing a chemical 85 to be kept at a certain temperature and / or pressure, for example LNG to maintain at -190 ° C during transoceanic transport, or LPG (Figure 16). The second volume 9 to be thermally managed is that of the tank 83 and a first volume 7 may be water, such as seawater.

The wall 80 is provided with an assembly 10 according to at least one of the types conforming to the solution presented above and here, in other words, from a series of said insulating pieces 1.

The assembly 10 comprises in the example several layers of such parts, here a combination of parts (in T and Π) imbricated which, via elbows, block the flow F by changing direction F1 / F2, as already explained .

The wall 80 may in particular integrate, contain or be doubled by the assembly 10.

As in the example, the tank limiting wall 80 can define a partition between two compartments, or define or belong to all or part of a hull 87 of a boat 89.

The boat 89 may be a ship and therefore be intended for marine navigation.

Using such a solution by elementary bricks 1 will follow the arcuate shape of the hull.

Providing the base wall 91 of the boat 89, the concave side, of one or more assembly (s) 10 may allow to follow inside the curved shape of the shell while ensuring the expected thermal management performance.

Internally, this (these) assembly (s) 10 may be doubled (s) by at least one wall compatible with the product 85 content.

Another application could concern the production of an insulating box around a chamber for producing liquefied gas, with for example an internal volume 9 at -196 ° C. to be thermally controlled and an external environment 7 at the atmospheric temperature of the place. between -30 and 45 ° C. Note also that in connection with the intended modular construction, another problem was taken into account, namely the size and weight.

Thus, it is rather recommended that, in the "redirected" direction of the F1 / F2 flows from the initial flow F (as in the direction of FIG. 17), there is a transverse overlap R of a workpiece 1 by the adjacent workpiece (see FIG. Figures 10,11, 24, in the direction 100 Figure 17) less than or equal to 500mm, with parts (1, 1 a, 1 b) therefore containing thermal insulation.

The overall thickness e will preferably be less than 300mm.

The elementary surface of each piece 1 will preferably be less than or equal to 2.5 m ² .

The wall of the casing 3 of each piece 1 will preferably be of stainless steel (or other metal or lighter alloy) less than 1 .2 mm.

Claims

1. Thermal insulating assembly comprising a series of thermal insulation parts (1, 1 a, 1 b) establishing thermal bridges between them, at least for some, and which are:

- arranged in several layers (13a, 13b, 13c) according to a thickness that each part presents and which varies (e1, e2) according to a length that said part presents transversely to said thickness, and along which each said part presents externally to the minus a projection (21) adjacent to a hollow (23),

- offset and nested two by two transversely, from said layer to the adjacent layer, so that a projection of a part of one layer is engaged in a recess of a part of the adjacent layer, thus forcing a heat flow (F ), generally established according to the thickness, along the thermal bridges, to change direction towards an isotherm (11) then to be blocked by an orientation locally substantially in the opposite direction,

characterized in that:

- said assembly is interposed between a first volume (7) and a second volume (9) to be thermally managed with respect to the first volume,

- said layers (13a, 13b, 13c) are arranged in a direction (D) passing through the first and second volumes, the thicknesses and length(s) being defined respectively in said direction and transversely to it,

- on at least one of the layers, at the longitudinal ends of two adjacent and successive pieces of the layer where these two pieces each have a so-called projection, said thermal bridges between said two pieces of the layer are established:

-- over the entire thickness of the projections (21), -- facing, on the adjacent layer, a longitudinally intermediate part of a hollow of said transversely offset part.

2. Assembly according to claim 1, where a said projection (21) of a said piece of a layer is engaged in a said hollow (23) of a single said piece of the adjacent layer,

3. Assembly according to claim 1 or 2, where the thermal insulation parts (1, 1 a, 1 b) are individually internally under controlled atmosphere (PIV).

4. Assembly according to any one of the preceding claims, where at least some of the thermal insulation parts comprise an envelope (3) and at least one thermal insulating element (25) which the envelope surrounds at least locally, the envelope and said element each having externally at least one bend (5.50), and according to said thickness (e) and direction (D), said bends (5.50) define on each part at least one said projection (21) relative to to a said hollow (23).

5. Assembly according to any one of the preceding claims, where said series of parts (1, 1 a, 1 b) defines a panel (67) having a edge which has, on at least two sides, projecting or recessed parts (71, 111) of certain said parts each engaged with a complementary grooved or projecting shape of an end block (75a, 75b, 75c) comprising at least one thermal insulating element (25).

6. Assembly according to claim 5 which is presented as a housing having side walls and a bottom, each comprising at least one said panel (67) engaged, on its edge, with end blocks (75a, 75b, 75c) which are for some common between the side walls and the bottom.

7. Assembly according to any one of claims 5,6, where the or each panel (67) is clamped between two side plates (55,57) fixed with the end blocks.

8. Assembly according to any one of the preceding claims where, in said changed direction (100) of the flow (F), a part (1,1 a, 1 b) transversely covers (R) an adjacent part (1,1 a , 1 b) over a distance less than or equal to 500mm, and/or the elementary surface area of each said room is less than or equal to 2.5m ² .

9. Thermal insulation part for the assembly according to any one of claims 1 to 3, said part comprising an envelope (3) and at least one thermal insulating element (25) which the envelope surrounds at least locally, characterized in that the envelope and the thermal insulating element (25) each have externally several bends (5.50) defining projections (21) adjacent to recesses (23).

10. Part according to any one of claims 9 to 16, the envelope (3) of which and said at least one thermal insulating element (25) have a section in T, or Π or H or I, or, in one direction , a combination of several of these sections or a repetition of at least one of them.

1 1 . Wall (80) limiting a tank (83) containing a chemical product to be kept at a certain temperature and/or pressure, the wall being provided with an assembly according to any one of claims 1 to 8 or with a series of parts according to any one of claims 9,10.

12. Boat comprising a hull (87) provided with the tank limitation wall (80) (83) according to claim 11.