Thermal insulation device

Abstract

The invention relates to a thermal insulation device comprising: - a metal enclosure, and, - several metal sheets stacked successively in a thickness direction of the metal enclosure, the metal sheets comprising: - metal sheets with reliefs (1a); - metal support sheets (2a) arranged between the metal sheets with reliefs; each metal sheet with reliefs having a plurality of first reliefs (11) having a first height along the thickness direction, the first reliefs being in contact with a metal support sheet adjacent to the metal sheet with reliefs, each metal sheet with reliefs having a plurality of second reliefs (12) having a second height along the thickness direction; the first height being greater than the second height.

Description

Technical field

[0001] The invention relates to the field of thermal insulation and in particular to the thermal insulation of enclosures or even heat transport or production systems.

[0002] Without being limited thereto, the invention finds a particular application in industrial processes implemented in the nuclear industry. Technological background

[0003] Thermal insulation of a physical system consists of reducing thermal exchanges or transfers between the interior and exterior of this physical system.

[0004] For example, the physical system can be a closed enclosure, piping, equipment or devices.

[0005] There are three types of heat transfer or exchange: conduction, due to the progressive diffusion of thermal agitation in matter; convection, thermal transfer which accompanies the macroscopic movements of matter; radiation, which corresponds to the propagation of photons.

[0006] Generally, the three types of transfers coexist, however, depending on the thermodynamic conditions of the system, the respective proportions of the three types of transfers can vary.

[0007] In order to reduce heat exchanges between the inside and outside of the physical system, it is common to equip the physical system to be insulated with one or more thermal insulation devices designed according to the desired reduction in heat exchange, the type(s) of heat transfer to be limited as a priority, the geometry of the system to be insulated and other constraints specific to the system to be insulated or its environment.

[0008] According to one example, US-B-6391469 describes a multi-layer thermal or sound insulation or shielding panel made of layers of corrugated metal sheets, with a flat sheet interposed between each pair of corrugated sheets, for reflective thermal insulation in high temperature applications. Summary

[0009] One idea behind the invention is to provide an effective insulation device against the three types of heat transfer.

[0010] In addition, another idea behind the invention is to limit the risks of damage to the physical system to be isolated.

[0011] According to one embodiment, the invention provides a thermal insulation device comprising: a metal enclosure, and, a plurality of metal sheets stacked successively in a thickness direction of the metal enclosure, the metal sheets comprising: embossed metal sheets; supporting metal sheets disposed between the embossed metal sheets; each embossed metal sheet having a plurality of first reliefs having a first height in the thickness direction, the first reliefs bearing against a supporting metal sheet adjacent to the embossed metal sheet, each embossed metal sheet having a plurality of second reliefs having a second height in the thickness direction; the first height being greater than the second height.

[0012] Thanks to these characteristics, the thermal insulation device makes it possible to limit the three different types of heat transfer (conduction, convection and radiation).

[0013] The first plurality of reliefs of a relief metal sheet are provided to limit contact with adjacent supporting metal sheets within the enclosure.

[0014] In doing so, the first plurality of reliefs makes it possible to limit the transfer of thermal energy by conduction. The heat transfer by conduction is all the more limited as the cross-section of the first reliefs is small.

[0015] The second plurality of reliefs of a relief metal sheet are used to limit the movement of air within a space between an adjacent relief metal sheet and a supporting metal sheet.

[0016] In doing so, the second plurality of reliefs makes it possible to limit the transfer of thermal energy by convection within the spaces comprising air between the relief metal sheets and the support metal sheets.

[0017] Finally, the metallic material(s) of the metal sheets give high reflectivity, particularly in the infrared range, to the metal sheets.

[0018] In doing so, the metal sheets help limit the transfer of thermal energy by radiation.

[0019] An enclosure thickness direction is a direction normal to a wall of the enclosure.

[0020] The height of the reliefs is measured in a direction normal to an average surface of each relief metal sheet.

[0021] The height of the reliefs considered is the distance from peak to peak, or from summit to summit, between two reliefs of the same type (first or second) located on either side of a relief metal sheet.

[0022] Furthermore, apart from the metallic elements composing it, the device only contains air or another ambient gas. The device does not contain glass wool or other solid material that could damage the system to be insulated in the event of an incident.

[0023] According to embodiments, such a thermal insulation device may comprise one or more of the following features.

[0024] According to one embodiment, the plurality of first reliefs protrudes relative to the two faces of said relief metal sheet. Thus, a gap corresponding to the height of the first reliefs is maintained between the relief metal sheet and two support metal sheets arranged on either side of the relief metal sheet.

[0025] According to one embodiment, the plurality of second reliefs protrudes relative to both sides of said relief metal sheet. Convection can be slowed by the second reliefs on either side of the relief metal sheet, which limits heat transfer by convection.

[0026] According to one embodiment, the plurality of first reliefs is located on the surface of the relief metal sheet according to a first periodic spatial arrangement.

[0027] Thus, the contact points between two consecutive metal sheets are distributed regularly, which promotes uniform thermal insulation performance.

[0028] According to one embodiment, the plurality of second reliefs is located on the surface of the relief metal sheet according to a second periodic spatial arrangement.

[0029] Thus, the reliefs slowing down the air flows are distributed regularly within the layer of air contained between two metal sheets, which promotes uniform thermal insulation performance.

[0030] According to one embodiment, the plurality of first reliefs form protuberances distributed on the surface of the relief metal sheet according to a periodic spatial arrangement defined according to a first and a second spatial periods; the first spatial period being defined in a first direction of a mean plane of the surface of the relief metal sheet; and the second spatial period being defined in a second direction of the mean plane.

[0031] Thus, the contact between two consecutive metal sheets takes place at the level of localized protuberances, which can be quite punctual, i.e. have a small cross-section. Unlike a corrugation, such a protuberance does not extend continuously along a line. This makes it possible to limit as much as possible the heat transfer by conduction between two consecutive metal sheets.

[0032] The first and second directions are preferably perpendicular. However, it is possible for the first and second directions to be intersecting and not perpendicular.

[0033] According to one embodiment, the plurality of second reliefs form protuberances distributed on the surface of the relief metal sheet according to a periodic spatial arrangement defined according to a third and a fourth spatial periods; the third spatial period being defined in the first direction of the mean plane of the surface of the relief metal sheet; and the fourth spatial period being defined in the second direction of the mean plane.

[0034] Preferably, a difference between the first height and the second height is greater than or equal to 4 mm.

[0035] According to one embodiment, the first height is greater than 6 mm and less than 30 mm. For example, the first height may be between 7 and 20 mm, or even between 12 and 16.5 mm. In other words, the peak-to-peak, or vertex-to-vertex, distance between two first reliefs located on either side of a relief metal sheet is greater than 6 mm and less than 30 mm. It may be between 7 and 20 mm, or even between 12 and 16.5 mm.

[0036] The first height controls the spacing between successive metal sheets and qualitatively contributes to reducing conduction and radiation transfer as the first height increases. However, the amount of air contained between two metal sheets also increases as the first height increases, which could promote convective transfer. The thickness range between 6 mm and 30 mm provides a good compromise to reduce the overall heat transfer between two consecutive metal sheets.

[0037] According to one embodiment, the second height is between 3 and 15 mm. Similarly, the second height corresponds to the peak-to-peak, or apex-to-apex, distance between two second reliefs located on either side of a relief metal sheet.

[0038] Thus, the air flows generated by the temperature gradient between two consecutive metal sheets are slowed down, which limits the heat transfer by convection between two consecutive metal sheets.

[0039] According to one embodiment, the supporting metal sheet is a flat metal sheet or an embossed metal sheet. In the latter case, the embossed metal sheet may have an embossing obtained by stamping.

[0040] For example, this embossing can be achieved by pressing two forming dies of a press machine against a flat metal sheet.

[0041] Thanks to embossing, the support sheet also helps to limit heat transfer by convection between two consecutive metal sheets.

[0042] The embossed metal sheet then comprises a single plurality of reliefs on its surface. In addition, the height of the embossments obtained by stamping is less than 5 mm

[0043] According to one embodiment, the embossed metal sheet is made of stainless steel.

[0044] Thus, embossed metal sheets have excellent long-term stability, can be cold worked and have a high coefficient of reflectivity for thermal radiation.

[0045] According to one embodiment, the metal support sheet is made of stainless steel.

[0046] Thus, the metal support sheets have excellent long-term stability, can be cold worked and have a high coefficient of reflectivity for thermal radiation.

[0047] According to one embodiment, the metal enclosure is also made of stainless steel. Similarly, the metal enclosure has excellent long-term stability and can be cold worked while having a high coefficient of reflectivity for thermal radiation.

[0048] According to one embodiment, a thickness of the embossed metal sheet is between 0.01 and 0.10 millimeters, for example equal to 0.05 mm. According to one embodiment, a thickness of the support metal sheet is between 0.01 and 0.10 millimeters, for example equal to 0.05 mm.

[0049] Thus, a high number of consecutive metal sheets can be used without excessively increasing the weight of the insulation device, to finely segment the interior space of the enclosure and thus minimize thermal convection.

[0050] According to a particular embodiment, the thickness of the walls of the enclosure is between 0.4 and 0.8 mm.

[0051] According to one embodiment, the metal enclosure comprises one or more flanges with perforated thickness.

[0052] These flanges correspond to the portions or walls of the enclosure that must be in contact with other juxtaposed insulation devices, as opposed to the portions or walls of the enclosure facing outwards or towards the physical system to be insulated. The thickness of the flanges is thus less than the other portions of the enclosure, which makes it possible to limit the thermal bridges caused by these walls that connect the portions of the enclosure facing outwards to the portions of the enclosure facing the physical system to be insulated. For example, the thickness of each flange is 0.1 mm.

[0053] According to one embodiment, the embossed metal sheets are welded to at least one wall of the metal enclosure. Preferably, one or each embossed metal sheet is tack welded to the metal enclosure. The tack welding may be carried out over the entire circumference of the metal sheet or, conversely, over only certain portions of the circumference, for example the portions corresponding to two opposite faces of the metal enclosure.

[0054] According to one embodiment, the supporting metal sheets are welded to at least one wall of the metal enclosure. Preferably, one or each supporting metal sheet is tack welded to the metal enclosure. The tack welding may be carried out over the entire circumference of the metal sheet or, conversely, over only certain portions of the circumference, for example the portions corresponding to two opposite faces of the metal enclosure.

[0055] According to one embodiment, the device comprises from 5 to 30 metal sheets, preferably between 10 and 20 metal sheets.

[0056] The number of metal sheets may depend on the desired thermal insulation performance.

[0057] It may also depend on the space available around the physical system to be insulated or the maximum weight to be respected for the insulation device. According to one implementation, this maximum point is 25 kg per insulation device.

[0058] Thus, these ranges allow a good compromise to be obtained between thermal insulation performance, the dimensions and weight of the enclosure and the cost of the thermal device.

[0059] According to one embodiment, the thermal insulation device has a thickness in the thickness direction of the enclosure of between 30 and 250 mm.

[0060] According to one embodiment, the invention also provides an installation intended for the production of energy comprising at least one nuclear reactor and a thermal insulation device of the aforementioned type arranged to insulate a component of the nuclear reactor, for example a steam pipe or a tank.

[0061] According to one embodiment, the invention provides a method of manufacturing a thermal insulation device, the method comprising: forming a plurality of embossed metal sheets, each of said embossed metal sheets comprising a plurality of first embossments and a plurality of second embossments on its surface and being obtained by pressing two forming dies against a flat metal sheet, the forming dies comprising a plurality of first pins and a plurality of second pins, a height of the first pins being greater than a height of the second pins; the height of the first pins determining the height of the first embossments; and the height of the second pins determining the height of the second embossments such that a height of the first embossments is greater than a height of the second embossments;within a metal enclosure, successively stacking in a thickness direction of the metal enclosure, the embossed metal sheets and a plurality of support metal sheets so that the support metal sheets are arranged between the embossed metal sheets.;

[0062] The height of the pins is measured relative to the plane of the matrix considered.

[0063] According to one embodiment, the first pins are distributed within the forming dies according to a first periodic spatial arrangement so that the first reliefs are located on the surface of the relief metal sheet according to this first periodic spatial arrangement.

[0064] Thus, the first reliefs of the formed relief metal sheet are distributed within it according to periodic spatial arrangements determined by the periodic arrangements of the first pins.

[0065] According to one embodiment, the second pins are distributed within the forming dies according to a second periodic spatial arrangement so that the second reliefs are located on the surface of the relief metal sheet according to this second periodic spatial arrangement.

[0066] Thus, the second reliefs of the formed relief metal sheet are distributed within it according to periodic spatial arrangements determined by the periodic arrangements of the second pins. Brief description of the figures

[0067] The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes, with reference to the accompanying drawings. [ Fig. 1 ] There [ Fig. 1] represents a sectional view of the metal sheets of a straight thermal insulation device. [ Fig.2 ] There [ Fig.2 ] is a sectional view of the metal sheets of a curved thermal insulation device. [ Fig.3 ] There [ Fig.3 ] illustrates a curved thermal insulation device, capable of insulating a pipe from a pipeline. [ Fig.4 ] There [ Fig.4 ] also illustrates a curved thermal insulation device, capable of insulating a pipe from a pipeline. [ Fig.5 ] There [ Fig.5 ] illustrates a press machine comprising a lower forming die and an upper forming die each comprising pins. [ Fig.6 ] There [ Fig.6 ] illustrates a first forming die comprising pins distributed according to a first example of periodic arrangement. [ Fig.7 ] There [ Fig.7 ] illustrates a second forming die comprising pins distributed in a second example of a periodic arrangement. [ Fig.8 ] There [ Fig.8 ] illustrates a relief metal sheet comprising a plurality of first reliefs and a plurality of second reliefs. [ Fig.9 ] There [ Fig.9 ] illustrates a step of manufacturing a thermal insulation device according to a first exemplary embodiment: the stacking of a metal sheet with reliefs within the enclosure of a thermal insulation device. The pluralities of first and second reliefs are distributed according to a first example of periodic arrangement. [ Fig. 10 ] There [ Fig. 10 ] illustrates another step in the manufacture of the thermal device according to the first embodiment: the stacking of a metal support sheet within the enclosure of the thermal insulation device. [ Fig. 11 ] There [ Fig. 11] also illustrates the stacking of a metal sheet within the enclosure of a thermal insulation device according to a second exemplary embodiment. The pluralities of first and second reliefs are distributed according to a second exemplary periodic arrangement. [ Fig. 12 ] There [ Fig. 12 ] also illustrates the stacking of a metal support sheet within the enclosure of a thermal insulation device according to the second embodiment. [ Fig. 13 ] There [ Fig. 13 ] illustrates an enclosure to be insulated comprising several thermal insulation devices. [ Fig. 13 ] There [ Fig. 14 ] illustrates a portion of piping comprising several pipes to be insulated comprising several thermal insulation devices. Description of the embodiments

[0068] THE Figures 3 and 4 illustrate a curved thermal insulation device 100 according to an exemplary embodiment.

[0069] The device comprises a metal enclosure 20 inside which are stacked embossed metal sheets 1 and support metal sheets 2 (not visible in the Figures 3 and 4 ). The metal sheets 1 and 2 are fixed, for example by welding, to the internal walls of the metal enclosure 20.

[0070] The welding may be continuous or, on the contrary, only on some parts of the circumference of each metal sheet 1 or 2. According to one embodiment, the welding is a tack weld.

[0071] Any geometry - shape and dimensions - is possible for the enclosure 20 depending on the geometry of the system it must isolate. figures 9 to 12 illustrate enclosures 20 with shapes and dimensions that differ from each other and from the example embodiment of the Figures 3 and 4 . In addition, the figures 13 and 14illustrate physical systems to be insulated which have varied shapes, both rectilinear and curved, and also have varied dimensions. The enclosure 20 of the thermal insulation device(s) capable of equipping such devices can therefore also be of varied shapes and dimensions.

[0072] As illustrated in [ Fig.3 ], the enclosure 20 may comprise an enclosure body 20b and perforated flanges 20a. The enclosure body 20b is a half-cylinder-shaped shell having a central space 200. The central space 200 is adapted to receive a pipe to be thermally insulated.

[0073] The openwork flanges 20a correspond to portions of walls having a reduced thickness compared to the rest of the metal enclosure 20.

[0074] The enclosure 20 is made of metals or metal alloys. Thus, the enclosure 20 benefits from the reflective properties of metals, which makes it possible to reduce heat transfer by radiation.

[0075] According to one embodiment, the enclosure 20 is made of stainless steel, also called stainless steel or stainless steel. Stainless steel or stainless steel is a steel within the meaning of standard EN 10020 containing at least 10.5% chromium and at most 1.2% carbon according to this standard EN 10020.

[0076] Any type of stainless steel as defined in standard EN 10020 can be used to make the enclosure 20. Stainless steels have poor thermal conductivity. Thus, the enclosure 20 reduces heat transfer by conduction. In addition, most different types of stainless steel are easy to cut, bend, deform, and weld, which makes it easy to manufacture the enclosure 20.

[0077] According to an exemplary embodiment, the enclosure 20 is made of 304 stainless steel.

[0078] In addition to the general advantages of stainless steels presented above, 304 stainless steel can be cold worked, has very good malleability and its electrical and thermal conductivity is low for a metal: 16.2 W / m·K at 100 °C and 21.5 W / m·K at 500 °C. The enclosure 20 benefits from its physical properties and thus makes it possible to reduce heat transfer by conduction.

[0079] Furthermore, the thickness of the walls of the metal enclosure 20 is between 0.5 and 0.8 mm. When the enclosure has an enclosure body 20b and perforated flanges 20a, the latter have a thickness of 0.1 mm. Such a thickness makes it possible to limit a thermal bridge between the walls of the metal enclosure 20 in contact with the physical system to be insulated and the walls of the metal enclosure 20 in contact with the outside.

[0080] THE Figures 1 and 2schematically illustrate the stacking within the enclosure 20 of the metal sheets 1 and 2. The metal sheets 1 and 2 are stacked on top of each other in the thickness direction E of the enclosure 20 (not shown in Figures 1 and 2 ). The metal sheets 1 and 2 are fixed to the walls of the enclosure 20, for example by welding.

[0081] The stack of metal sheets 1 and 2 may comprise as many metal sheets 1 and 2 as necessary depending on the desired insulation performance. In practice, the number of stacked metal sheets 1 and 2 may depend on the temperature of the physical system to be thermally insulated, the desired thermal insulation performance and / or the geometry of the enclosure 20. The geometry of the enclosure 20 may depend on the space available in the environment of this system.

[0082] Thus, for illustration purposes, six embossed metal sheets 1 (1a to 1f) and six support metal sheets 2 (2a to 2f), i.e. twelve metal sheets 1 and 2, are stacked on top of each other at [ Fig. 1 ]. To the [ Fig.2 ], four embossed metal sheets 1 and four supporting metal sheets 2, i.e. eight metal sheets 1 and 2, are stacked.

[0083] The metal sheets 1 and 2 are made of metals or metal alloys like the enclosure 20. In a similar manner to the enclosure 20, the metal sheets 1 and 2 benefit from the reflective properties of the metals which makes it possible to reduce heat transfer by radiation.

[0084] According to one embodiment, the metal sheets 1 and 2 are made of stainless steel, also called stainless steel or stainless steel.

[0085] Similarly, any type of stainless steel as defined in EN 10020 can be used to produce metal sheets 1 and 2. Stainless steels have relatively poor thermal conductivity. Thus, metal sheets 1 and 2 allow for reduced heat transfer by conduction compared to other metals. In addition, most of the different types of stainless steel are easy to cut, bend, deform and weld, which makes it easy to produce metal sheets 1 and 2, as will be described in more detail below.

[0086] According to an example of embodiment, the metal sheets 1 and 2 are made of 304 stainless steel.

[0087] Similarly, in addition to the general advantages of stainless steels presented above, metal sheets 1 and 2 benefit from its physical properties and thus reduce heat transfer by conduction.

[0088] Furthermore, the metal sheets 1 and 2 have a thickness of between 0.01 and 0.10 millimeters, for example 0.05 mm. Such a thickness makes it possible to handle the metal sheets 1 and 2 without breaking them, particularly during the step of forming the pluralities of reliefs.

[0089] The embossed metal sheets 1 comprise on their surface a plurality of first reliefs 11 and a plurality of second reliefs 12 as illustrated in Figures 1 and 2 .

[0090] For example, at the [ Fig. 1], the embossed metal sheet 1a comprises a plurality of first reliefs 11 and a plurality of second reliefs 12. As illustrated, the plurality of first reliefs 11 has a height, in the thickness direction E, greater than the height of the plurality of second reliefs 12. In other words, the distance between two vertices of first reliefs 11 located on either side of a metal sheet is greater than the distance between two vertices of second reliefs 12 located on either side of this metal sheet.

[0091] According to one embodiment, the plurality of first reliefs 11 each have the same height. For example, the height of the first reliefs 11 is greater than 6 mm. This height corresponds to the peak-to-peak, or apex-to-apex, distance between two reliefs located on either side.

[0092] In addition, according to one embodiment, the metal sheet 1a has on its two faces a plurality of first reliefs 11, of the same height or not, as illustrated in Figures 1 and 2 In other words, the plurality of first reliefs 11 protrudes relative to the two faces of the relief metal sheet.

[0093] According to a preferred embodiment, the metal sheet 1a has on its two faces a plurality of first reliefs 11 of the same height greater than 6 mm, for example 12.5 mm or 16.5 mm. Thus, two peaks of first reliefs 11 located on either side of the metal sheet 1a are separated by a distance greater than 6 mm, for example a distance of 12.5 mm or 16.5 mm.

[0094] In addition, according to one embodiment, the plurality of first reliefs 11 is located on the surface of the relief metal sheet 1 according to a first periodic spatial arrangement.

[0095] For example, the plurality of first reliefs 11 form protuberances distributed on the surface of the relief metal sheet 1a according to a periodic spatial arrangement defined according to a first and a second spatial periods. Thus, this spatial arrangement is not reducible to a sectional view as shown in Figures 1 and 2 .

[0096] The first spatial period is defined in a first direction of a mean plane of the surface of the embossed metal sheet and the second spatial period is defined in a second direction of the mean plane. These two spatial periods may be different from each other.

[0097] According to one embodiment, the two directions are orthogonal to each other.

[0098] For example, the two directions are orthogonal to each other and the first and / or second spatial period is between 150 and 300 mm, for example they are 240 mm.

[0099] Likewise, according to one embodiment, the plurality of second reliefs 12 have the same height. For example, the height of the second reliefs 12 is between 3 and 15 mm. Similarly, this height corresponds to the peak-to-peak, or apex-to-apex, distance between two reliefs 12 located on either side of a relief metal sheet.

[0100] In addition, according to one embodiment, the metal sheet 1a has on its two faces a plurality of second reliefs 12, of the same height or not, as illustrated in Figures 1 and 2 In other words, the plurality of second reliefs 12 protrudes relative to the two faces of said relief metal sheet 1.

[0101] According to a preferred embodiment, the metal sheet 1a has on its two faces a plurality of second reliefs 12 of the same height of between 3 and 15 mm, for example 8 mm. Thus, two peaks of second reliefs 12 located on either side of the metal sheet 1a are separated by a distance of between 3 and 15 mm, for example 8 mm.

[0102] These embodiments can be combined with each other as illustrated in [ Fig.1] or 2 : the embossed metal sheet 1a has on its two faces a plurality of first reliefs 11 of the same height greater than 6 mm and a plurality of second reliefs 12 of the same height between 3 and 15 mm.

[0103] According to one embodiment, the difference between the first and second heights is between 4 and 10 mm.

[0104] Likewise, the plurality of second reliefs 12 form protuberances distributed on the surface of the metal sheet with reliefs according to a periodic spatial arrangement 1 defined according to a third and a fourth spatial periods. Likewise, this spatial arrangement is not reducible to a sectional view as shown in Figures 1 and 2 .

[0105] The third spatial period is defined in a third direction of the mean plane of the surface of the embossed metal sheet and the fourth spatial period is defined in a fourth direction of this mean plane.

[0106] The third and fourth spatial periods may be different from each other.

[0107] According to one embodiment, these third and fourth directions are orthogonal to each other.

[0108] For example, these two directions are orthogonal to each other and the first and / or second spatial period is between 50 and 200 mm, for example 80 mm.

[0109] The supporting metal sheets 2 are flat metal sheets or embossed metal sheets obtained by stamping (not shown).

[0110] To the [ Fig.1] or 2 , metal sheets 2 (2a to 2f) are flat metal sheets.

[0111] Embossed metal carrier sheets have a single plurality of reliefs on their surface. In addition, a height of these reliefs is less than 5 mm. This height corresponds to the edge-to-edge distance between two embossments located on either side of a metal carrier sheet.

[0112] Within the enclosure 20, the plurality of first reliefs 11 of each relief metal sheet 1 bears against a support metal sheet 2 adjacent to the relief metal sheet 1 as illustrated in Figures 1 and 2 . Thus, the plurality of first reliefs 11 makes it possible to limit the contact between the metal sheets 1 and 2. In doing so, the first reliefs 11 make it possible to limit the heat transfers by conduction between two consecutive metal sheets 1 and 2 within the stack.

[0113] For example, the first reliefs 11 of the metal sheet 1a rest on the supporting metal sheet 2a.

[0114] Likewise, the first reliefs 11 of the layer 1c bear against the supporting metal sheet 2b and against the supporting metal sheet 2c.

[0115] In addition, the embossed metal sheets 1 and the supporting metal sheets 2 are attached to the inner walls of the metal enclosure 20. For example, the entire periphery of each metal sheet is welded to the inner walls of the metal enclosure 20.

[0116] Thus, each pair of embossed metal sheets 1 and supporting metal sheets 2 - for example the pair (1c; 2c) form a layer of air within the enclosure 20.

[0117] The stacking of metal sheets 1 and 2 therefore forms layers of air which limit thermal exchanges by conduction since air is a thermal insulator.

[0118] In addition, the second reliefs 12 of lower height than the first reliefs 11 make it possible to limit the movements of the air contained in each layer formed by a metal sheet with reliefs 1, a support sheet 2 and the walls of the enclosure 20. Thus, the second reliefs 12 make it possible to limit the heat transfer by convection. Manufacturing process

[0119] We will now describe the steps of a manufacturing process for a thermal insulation device.

[0120] The first step is to form a relief metal sheet 1 comprising a plurality of first reliefs 11 and a plurality of second reliefs 12 on its surface such as those described previously, by pressing two forming dies 30a and 30b of a press machine against a flat metal sheet.

[0121] There [ Fig.5] illustrates a press machine 30 comprising an upper forming die 30a and a lower forming die 30b.

[0122] Each die 30a and 30b comprises a plurality of first pins 31 and a plurality of second pins 32.

[0123] These two pressing dies make it possible to form a relief metal sheet 1 by pressing the two dies against a flat metal sheet to be formed.

[0124] The height of the first pins 31 then determines the height of the first reliefs 11 of the formed relief metal sheet 1. Similarly, the height of the second pins 32 determines the height of the second reliefs 12 of the formed relief metal sheet 1.

[0125] The first pins 31 have a height between 60 and 68 mm and the second pins 32 have a height between 50 and 60 mm.

[0126] The height of the pins 31 and 32 is measured relative to the plane of the pressing dies 30a and 30b.

[0127] Thus, by simultaneously pressing the flat metal sheet to be formed, the dies 30a and 30b form on the surface of the metal sheet a plurality of first reliefs 11 and a plurality of second reliefs 12. In other words, the flat metal sheet to be formed is sandwiched by the two forming dies 30a and 30b.

[0128] The movement distance of the dies (their stroke) and the heights of the pins 31 and 32 determining the heights respectively of the first and second reliefs 11 and 12, the metal sheet with reliefs 1 then comprises a plurality of first reliefs 11 and a plurality of second reliefs 12 of a height less than the height of the first reliefs 11. In particular, the height of the first and second reliefs is determined by the end-of-stroke position of the two dies. This end-of-stroke position can be controlled by a programmable controller. More precisely, the height of the first reliefs is equal to the length of the mutual overlap between the first pins 31 of the die 30a and the first pins 31 of the die 30b in the end-of-stroke position of the two dies.Likewise, the height of the second reliefs is equal to the length of the mutual overlap between the second pins 32 of the die 30a and the second pins 32 of the die 30b in the end-of-stroke position of the two dies, this overlap length necessarily being less since the second pins 32 are shorter than the first pins 31. More precisely, the difference between the two overlap lengths, therefore the difference between the heights of the two reliefs, is twice the difference in length between the second pin 32 and the first pin 31.

[0129] Furthermore, according to one embodiment, the first pins 31 are distributed within the forming dies 30a and 30b according to a first periodic spatial arrangement so that the first reliefs 11 are located on the surface of the relief metal sheet 1 according to this first periodic spatial arrangement.

[0130] This first periodic spatial arrangement is defined according to two spatial periods each extending in a non-collinear direction with respect to each other. These two directions can be orthogonal to each other.

[0131] Likewise, according to one embodiment, the second pins 32 are distributed within the forming dies 30a and 30b according to a second periodic spatial arrangement so that the second reliefs 12 are located on the surface of the relief metal sheet 1 according to this second periodic spatial arrangement.

[0132] Similarly, this second periodic spatial arrangement is defined according to two spatial periods each extending in a non-collinear direction with respect to each other. These two directions can be orthogonal to each other.

[0133] THE figures 6 And 7illustrate a particular combination of these two embodiments: the periodic arrangements are each defined according to two spatial periods and these two spatial periods have directions orthogonal to each other.

[0134] According to one embodiment, the flat metal sheet to be formed is made of stainless steel, which allows it to be worked cold as explained previously.

[0135] There [ Fig.8 ] schematically illustrates a relief metal sheet 1 formed by pressing the dies 30a and 30b against a flat metal sheet.

[0136] The embossed metal sheet 1 has on its surface first reliefs 11 and second reliefs 12 according to the periodic spatial arrangements of the pins 31 and 32 of the forming dies 30a and 30b.

[0137] The visible face of the metal sheet 1 makes it possible to distinguish the reliefs 11 and 12 forming bumps originating from the pins 31 and 32 of the lower die 30a and the reliefs 11 and 12 forming hollows originating from the pins 31 and 32 of the upper die 30b.

[0138] The second step is to form a plurality of embossed metal sheets 1 by repeating the previous step. A plurality of embossed sheets 1 can thus be formed from a plurality of flat metal sheets to be formed and the forming dies 30a and 30b.

[0139] Finally, the last step consists of, within a metal enclosure 20, successively stacking in a thickness direction of the metal enclosure 20, the formed embossed metal sheets 1 and a plurality of supporting metal sheets 2 so that the supporting metal sheets 2 are arranged between the embossed metal sheets 1.

[0140] Any fastening means can then be used to fasten the metal sheets to the walls of the enclosure 20. For example, it is possible to weld the metal sheets to the walls of the enclosure 20.

[0141] Depending on the thermal insulation performance, a determined number of metal sheets 1 and 2 are stacked within the enclosure 20.

[0142] The supporting metal sheets 2 can be flat or embossed following stamping.

[0143] According to one embodiment, the embossing of the support metal sheets 2 is carried out by the dies of the press machine equipped with a plurality of pins of a single height. Generally, the movement stroke of the dies to carry out the embossing is shorter than that provided for producing the first reliefs 11 and the second reliefs 12.

[0144] THE figures 9 And 11illustrate the stacking of a relief metal sheet 1a within an enclosure 20 according to two different embodiments: the dimensions and geometry of the enclosure 20 are not the same, the dimensions and shape of the relief metal sheets 1 are also different.

[0145] The embossed metal sheet 1a is fixed to the internal walls of the metal enclosure 20 by spot welding portions of its periphery to the internal walls of the metal enclosure 20. The weld line 61a indicates the location of this weld.

[0146] To the [ Fig.9 ], the traces 63 of the future welding lines are identified on the walls of the metal enclosure 20.

[0147] THE figures 10 And 12 they illustrate the stacking of a metal support sheet 2e within the enclosures 20 respectively illustrated in figures 9 And 11: here too, the support sheets 2 are not of the same dimensions or the same shape.

[0148] Similarly, a 62nd weld line is visible at the figures 10 And 12 . Examples

[0149] We will now describe two different examples of the thermal insulation device 100.

[0150] In the first example, the thermal device 100 is provided with an enclosure 20 of cylindrical shape, for example similar to the figures 9 and 10 , made from F17 / 304 stainless steel alloy.

[0151] Its dimensions are as follows: Inner diameter = 3604mm Outer diameter = 4083mm Thickness of enclosure 20 of device 100 = 240mm Height of enclosure 20 of device 100 = 693mm

[0152] The embossed metal sheets 1 comprise first embossments 11 with a height of 16.5 mm and second embossments 12 with a height of 10 mm obtained with the following press machine parameters:

[0153] The first forming die 30a and the second forming die are square in shape with a length of 1000 mm.

[0154] The first forming die 30a comprises nine first pins 31 having a height of 61.5 mm, 64.5 mm and 66.5 mm. They are distributed within the die in a square periodic pattern of 240 mm on each side and forming four squares of 240 mm on each side. Per line, they measure 66.5 mm, 64.5 mm and 61.5 mm. In other words, the first pins 31 are distributed within the first forming die in a spatial arrangement having two spatial periods of 240 mm extending along two orthogonal directions.

[0155] The second pins 32 have a height of 60 mm and are distributed within the forming die in a square periodic pattern of 80 mm sides. In other words, the second pins 32 are distributed within the first forming die in a spatial arrangement having two spatial periods of 80 mm extending along two orthogonal directions. There are 112 second pins 32.

[0156] The second forming die comprises 16 first pins distributed 31 according to the same square periodic pattern of 240 mm sides, and 105 second pins 32 distributed according to the same square periodic pattern of 80 mm sides.

[0157] The first 16 pins 31 form four lines of respective heights 66.5 mm, 64.5 mm, 63 mm and 61.5 mm and the second pins 32 have a height of 60 mm.

[0158] The insulation device according to the first example was subjected to a thermal insulation performance test under the following conditions: Ambient temperature = 40°C Heating temperature = 325°C Device 100 in horizontal position

[0159] All heights shown are defined relative to the surface area of ​​each die.

[0160] The supporting metal sheets 2 used are embossed metal sheets.

[0161] The results are as follows: Heat flux measured at the center of the external wall of device 100: 4.77. 10 -2< W / (mK) Average heat flux: 6.4. 10 -2< W / (mK)

[0162] In the second example, the thermal device 100 is provided with an enclosure 20 of generally cylindrical shape, for example similar to the [ Fig.3 ], made from F17 / 304 stainless steel alloy.

[0163] The dimensions are as follows: Inner diameter = 3604mm Outer diameter = 4083mm Thickness of enclosure 20 of device 100 = 240mm Height of enclosure 20 of device 100 = 693mm

[0164] The embossed metal sheets 1 comprise first embossments 11 with a height of 12.5 mm and second embossments 12 with a height of 7.5 mm obtained with the following press machine parameters:

[0165] The same press machine used is the same.

[0166] The first forming die comprises 16 first pins distributed 31 according to a square periodic pattern of 240 mm on each side, and 105 second pins 32 distributed according to the square periodic pattern of 80 mm on each side.

[0167] The first pins 31 have a height of 65 mm and 63 mm. Only the first row of first pins has a height of 65 mm. The second pins 32 have a height of 60 mm.

[0168] The second forming die has nine first pins 31 having a height of 65 mm and 63 mm. They are distributed within the die in a periodic square pattern of 240 mm on each side and forming four squares of 240 mm on each side. In rows of three, they measure 65 mm, 63 mm and 63 mm. In other words, the first pins 31 are distributed within the first forming die in a spatial arrangement having two spatial periods of 240 mm extending along two orthogonal directions.

[0169] The initial conditions of the thermal insulation performance test were as follows: Ambient temperature = 40°C Heating temperature = 323°C Device 100 in horizontal position

[0170] All heights shown are defined relative to the surface area of ​​each die.

[0171] The supporting metal sheets 2 used are embossed metal sheets.

[0172] The results are as follows: Heat flux measured at the center of the external wall of device 100: 6.36.10 -2< W / (m / K) Average heat flux: 8.54.10 -2< W / (m / K) Use

[0173] THE figures 13 and 14 illustrate physical systems to be isolated of different shapes and dimensions.

[0174] Devices 100 may be used to isolate such physical systems.

[0175] For example, the [ Fig. 13 ] illustrates an enclosure to be insulated equipped with thermal insulation devices 100. The enclosure is a cylinder closed by a hemispherical shell. Each insulation device 100 covers a surface portion corresponding to an angular sector around the axis of symmetry of the cylinder. The insulation devices 100 have the same radius of curvature as the covered cylinder portion.

[0176] For example, the [ Fig. 14] illustrates a plurality of pipes forming part of a portion of piping. Such piping may be installed in an installation intended for energy production, comprising at least one nuclear reactor. In such installations, the temperatures generated may be very high. Thus, the pipes of such installations are then equipped with several thermal insulation devices 100 having a right half-cylinder shape as illustrated in figures 3 or 4 , or right quarter-cylinders. Others

[0177] Although the invention has been described in connection with several particular embodiments, it is obvious that it is in no way limited thereto and that it includes all technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0178] The use of the verb "comprise", "comprise" or "include" and its conjugated forms does not exclude the presence of other elements or other steps than those set out in a claim.

[0179] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

1. Thermal insulation device (100) comprising: - a metal enclosure (20), and, - several metal sheets (1; 2) stacked successively in a thickness direction (E) of the metal enclosure (20), the metal sheets comprising: - embossed metal sheets (1); - support metal sheets (2) arranged between the embossed metal sheets; each embossed metal sheet (1) having a plurality of first reliefs (11) having a first height in the thickness direction (E), the first reliefs (11) bearing against a support metal sheet (2) adjacent to the embossed metal sheet (1), each embossed metal sheet (1) having a plurality of second reliefs (12) having a second height in the thickness direction (E); the first height being greater than the second height.

2. Thermal insulation device (100) according to the preceding claim, wherein the plurality of first reliefs (11) protrudes relative to both faces of said relief metal sheet (1) and the plurality of second reliefs (12) protrudes relative to both faces of said relief metal sheet (1).

3. Thermal insulation device (100) according to any one of the preceding claims, wherein the plurality of first reliefs (11) is located on the surface of the relief metal sheet (1) in a first periodic spatial arrangement; and / or the plurality of second reliefs (12) is located on the surface of the relief metal sheet (1) in a second periodic spatial arrangement.

4. Thermal insulation device (100) according to the preceding claim wherein the plurality of first reliefs (11) form protuberances distributed on the surface of the relief metal sheet according to a periodic spatial arrangement defined according to a first and a second spatial periods; the first spatial period being defined in a first direction of a mean plane of the surface of the relief metal sheet; and the second spatial period being defined in a second direction of the mean plane; and / or the plurality of second reliefs (12) form protuberances distributed on the surface of the relief metal sheet according to a periodic spatial arrangement (1) defined according to a third and a fourth spatial periods; the third spatial period being defined in the first direction of the mean plane of the surface of the relief metal sheet; and the fourth spatial period being defined in the second direction of the mean plane.

5. Thermal insulation device (100) according to any one of the preceding claims wherein the first height is greater than 6 mm and less than 30 mm.

6. Thermal insulation device (100) according to any one of the preceding claims wherein the second height is between 3 and 15 mm.

7. Thermal insulation device (100) according to any one of the preceding claims wherein the supporting metal sheet (2) is a flat metal sheet or an embossed metal sheet.

8. Thermal insulation device (100) according to any one of the preceding claims wherein the metal enclosure (20), the embossed metal sheet (1) and / or the supporting metal sheet (2) is made of stainless steel.

9. Thermal insulation device (100) according to any one of the preceding claims wherein a thickness of the embossed metal sheet (1) and / or the supporting metal sheet (2) is between 0.01 and 0.10 millimeters.

10. Thermal insulation device (100) according to any one of the preceding claims wherein the embossed metal sheets (1) are welded to at least one wall of the metal enclosure (20); and / or the supporting metal sheets (2) are welded to at least one wall of the metal enclosure (20).

11. Thermal insulation device (100) according to any one of the preceding claims comprising from 5 to 30 metal sheets (1;2), preferably between 10 and 20 metal sheets.

12. Thermal insulation device (100) according to any one of the preceding claims having a thickness in the thickness direction of the enclosure (20) of between 30 and 250 mm.

13. Installation intended for the production of energy, comprising at least one nuclear reactor and a thermal insulation device according to any one of the preceding claims arranged to insulate a component of the nuclear reactor.

14. A method of manufacturing a thermal insulation device (100), the method comprising: forming a plurality of embossed metal sheets (1), each of said embossed metal sheets comprising a plurality of first embossments (11) and a plurality of second embossments (12) on its surface and being obtained by pressing two forming dies (30a; 30b) against a flat metal sheet, the forming dies (30a; 30b) comprising a plurality of first pins (31) and a plurality of second pins (32), a height of the first pins (31) being greater than a height of the second pins (32); the height of the first pins (31) determining the height of the first embossments (11); and the height of the second pins (32) determining the height of the second embossments (12) such that a height of the first embossments (11) is greater than a height of the second embossments;within a metal enclosure (20), successively stacking in a thickness direction of the metal enclosure (20), the embossed metal sheets (1) and a plurality of supporting metal sheets (2) so that the supporting metal sheets (2) are arranged between the embossed metal sheets (1).; 15. Manufacturing method according to the preceding claim in which the first pins (31) are distributed within the forming dies (30a; 30b) according to a first periodic spatial arrangement so that the first reliefs (11) are located on the surface of the metal sheet with reliefs (1) according to this first periodic spatial arrangement; and / or the second pins (32) are distributed within the forming dies (30a; 30b) according to a second periodic spatial arrangement so that the second reliefs (12) are located on the surface of the metal sheet with reliefs (1) according to this second periodic spatial arrangement.