Expansion joint and associated heat transfer network

Abstract

Expansion joint and associated heat transfer network This expansion joint (100) is configured to isolate a portion of a pipe from a heat transfer network. The expansion joint (100) comprises a main body (102), which generally has a tube shape which extends along a longitudinal axis (A100), which is made of a thermally insulating material and which comprises two end portions (104A, 104B). The main body (102) comprises a central portion (108), which is interposed between the two end portions (104A, 104B) along the longitudinal axis (A100) and which is secured to each of the end portions (104A, 104B). The central portion is made of a material more flexible than a material of each of the end portions, the material of the central portion (108) having a modulus of elasticity at least 10 times greater than a modulus of elasticity of the material of each of the end portions (104A, 104B), preferably at least 50 times greater.Figure for abstract: 2.

Description

Title of the invention: Expansion joint and associated heat transfer network

[0001] The present invention relates to an expansion joint, as well as a heat transfer network comprising such an expansion joint.

[0002] We are interested here in the networks of pipes configured to transport cold or hot fluids, generically called heat transfer networks. Once in service, the pipes have a temperature substantially equal to a temperature of the transported fluid, for example up to -180°C in the case of a refrigeration network, or +120°C or even more in the case of a heating network. In certain cases, the heat transfer network is reversible, and the temperature of the transported fluid changes depending on the use, for example between -50°C and +120 C. The pipes are generally insulated by means of elements made of insulating material, often in the form of shells, the insulating elements being assembled around the pipes to reduce the heat losses of the fluids circulating in the pipes.

[0003] In many cases, particularly in the case of a refrigeration network, the insulating elements are coated, on an external face, with a vapor barrier, which prevents the penetration of water vapor into the insulation. Vapor barriers are, for example, in the form of adhesive tape comprising an aluminum membrane, the tape being applied continuously around pipes.

[0004] The insulating elements are generally installed during the installation of the heat transfer network, the pipes still being at ambient temperature, for example around 20°C. Due to the differential between the installation temperature and the operating temperature, for example -200°C in the case of a refrigeration network or +140°C in the case of a heating network, the pipes and the insulating elements expand, i.e. undergo dimensional variations which depend on the sign of the temperature differential, which leads to the appearance of tensile or compressive stresses in the insulating elements, depending on the sign of the temperature differential. These stresses tend to damage the vapor barrier and to generate gaps between the insulating elements, risking the passage of moisture, which is not desirable.

[0005] It is known to insert an insulating sleeve between two insulating elements, the insulating sleeve being for example cut on site to the desired dimensions from a block of elastomeric foam or mineral wool. The manufacture of the sleeve and its installation take time. In addition, it is difficult to obtain a good fit between the sleeve and the neighboring insulating elements, which causes thermal bridges, which which is not desirable.

[0006] It is these problems that the invention more particularly intends to remedy, by proposing an expansion joint which makes it possible to accommodate dimensional variations due to expansion, while being easy to install on an insulated pipe.

[0007] To this end, the invention relates to an expansion joint, which is configured to isolate a portion of a pipe from a heat transfer network, in which: - the expansion joint comprises a main body generally having the shape of a tube, which extends along a longitudinal axis, which forms a cavity configured to receive the pipe and which has two end portions, the cavity opening from each of the two end portions through a respective mouth, - the main body is made of a thermally insulating material, - the main body comprises at least one longitudinal slot, which connects one to the other the two mouths, each longitudinal slot being arranged so as to accommodate the passage of the pipe between an external side of the expansion joint and the cavity,

[0008] in which: - the main body comprises a central portion, which is interposed between the two end portions along the longitudinal axis and which is secured to each of the end portions, - the central portion is made of a material more flexible than a material of each of the end portions, the material of the central portion having a modulus of elasticity at least 10 times greater than a modulus of elasticity of the material of each of the end portions, preferably at least 50 times greater.

[0009] Thanks to the invention, the expansion joint is produced in the factory, in other words prefabricated, which guarantees good cohesion between the central portion, made of elastomeric material, and the end portions, which are more rigid. When the expansion joint is placed on a pipe between two insulating elements, the end portions of the expansion joint are in contact with the insulating elements, which have hardnesses similar, or even identical, to the end portions, which facilitates their assembly and bonding, so that the expansion joint remains bonded to the insulating elements even when the heat transfer network is a refrigeration network and the insulating elements contract, which avoids the creation of thermal bridges.

[0010] According to advantageous but not obligatory aspects of the invention, such an expansion joint may incorporate one or more of the following characteristics taken in isolation or in any technically admissible combination: - The central portion is made of a synthetic elastomeric rubber foam, for example EPDM or SBR. - The central portion has a longitudinal dimension sufficient to accommodate, by elastic deformation, a dimensional variation in compression greater than or equal to 45 mm, and a dimensional variation in extension greater than or equal to 5 mm. - Each of the end portions is made of a synthetic polymer cellular material, for example extruded polystyrene or polyisocyanurate. - The at least one longitudinal slot includes a first slot and a second slot, which are different from each other, the first slot and the second slot dividing the main body into two shells, which have complementary shapes to each other and which are configured to be assembled to each other to form the cavity, the expansion joint then being in a use configuration. - Each longitudinal slot provides a longitudinal rebate. - The expansion joint also includes a vapor barrier membrane, which surrounds the main body, the vapor barrier membrane being configured to absorb shear forces when a length of the central portion changes. - Each of the end portions has a circumferential groove, configured to cooperate, in particular by complementarity of shapes, with an insulating element of the heat transfer network located opposite.

[0011] The invention also relates to a heat transfer network, which comprises: - a pipe comprising two isolated portions, - two insulating elements, each insulated portion being respectively covered by one of the two insulating elements, - the expansion joint as defined previously, the expansion joint being inserted between the two insulating elements.

[0012] Advantageously: - the two end portions are glued to the facing insulating elements, while the central portion is elastically deformable, so as to compensate for the movements of the two end portions, along the longitudinal axis, under the effect of the dimensional variations of the insulating elements.

[0013] The invention will be better understood, and other advantages thereof will appear more clearly in the light of the following description of several modes of an expansion joint, of a heat transfer network and of an installation method, in accordance with its principle, given solely by way of non-limiting example and made with reference to the appended drawings, in which:

[0014] - [Fig.l] [Fig.l] is a longitudinal section of a heat transfer network conforming to a first embodiment of the invention, the heat transfer network comprising an expansion joint, also in accordance with the invention;

[0015] - [Fig.2] [Fig.2] represents respectively, on two inserts a) and b), the joint of di the expansion joint of [Fig.l] shown in perspective in a mounting configuration, and a cross-section of the expansion joint along a plane IIb in [Fig.l], and

[0016] - [Fig.3] [Fig.3] represents respectively, on three inserts a), b) and c), a section cross-section of the expansion joint of [Fig.l], a cross-section of an expansion joint according to a second embodiment of the invention, and a cross-section of an expansion joint according to a third embodiment of the invention.

[0017] A heat transfer network 10 is shown in [Fig.l]. The heat transfer network 10 comprises a pipe 12, which here has the shape of a rectilinear tube and extends along a main axis A12. According to typical examples, the pipe 12 is made of metal, or of polyvinyl chloride - noted PVC -, or even of a multi-layer material, that is to say a complex of several superimposed layers. The pipe 12 is configured to allow a fluid, for example a gas or a liquid, to pass through. The fluid is not shown.

[0018] Depending on the applications, the fluid passing through the heat transfer network 10 is at a temperature higher than the ambient temperature, for example at +80°C or +120°C. The heat transfer network 10 is then called a “heat network”. Ambient temperature means a temperature of the surrounding air, for example around 20°C. In certain applications, the fluid passing through the heat transfer network 10 is at a temperature lower than the ambient temperature, for example at -180°C. The heat transfer network 10 is then called a “refrigeration network”. In certain applications, the temperature of the fluid changes according to operating phases of the heat transfer network 10, for example between -50°C and +120°C. The heat transfer network 10 is then called a “reversible network”.

[0019] The fluid circulating in the pipe 12 is of course chosen as a function of the operating temperature(s) of the heat transfer network 10, this aspect not being detailed further in the context of the present description. The fluid is also called “heat transfer fluid”.

[0020] Insulating elements are provided to reduce thermal energy losses between the pipe 12 and the external environment. In the example of [Fig.l], the pipe 12 comprises two insulated portions 13A and 13B, the heat transfer network 10 comprising two insulating elements 14, each insulated portion 13A / 13B being respectively covered with one of the two insulating elements 14. The insulating elements 14 here each have the shape of a tube, in which the pipe 12 is received.

[0021] Here, a material is considered to be insulating when it has a thermal conductivity X - lambda -, expressed in Watts per square meter Kelvin, or W / m2-K, of less than 0.1 W / m2-K, preferably less than 0.050 W / m2-K, more preferably less than 0.040 W / m2-K. The thermal conductivity is evaluated at 10°C.

[0022] In the context of heat transfer networks 10 intended to transport a fluid at negative temperature, in particular refrigeration networks and reversible networks, insulating materials are preferred in the form of a cellular material, in other words a foam, preferably with closed cells to prevent the penetration of moisture, which would degrade the insulation performance over time. Preferably, the insulating materials used are rigid, that is to say have a compressive strength, expressed in kPa - kilo Pascal - and tested according to standard NF EN 826:2013, greater than or equal to 50 kPa, preferably greater than or equal to 80 kPa.

[0023] Preferred examples of rigid cellular insulators include extruded polystyrene - noted XPS -, which has a thermal conductivity X typically between 0.030 and 0.035 W / m2-K, or polyisocyanurate - noted PIR -, which has a thermal conductivity X typically between 0.020 and 0.030 W / m2-K.

[0024] The insulating elements are generally covered with a vapor barrier 20. The vapor barrier 20 is generally in the form of a membrane which prevents the passage of moisture. For example, the vapor barrier 20 is in the form of a roll of aluminum foil laminated on a flexible substrate, for example polyester, and having an adhesive face. The vapor barrier 20 is thus applied in a spiral around the insulating elements 14 positioned on the pipe 12, so as to produce a continuous vapor barrier surface 20.

[0025] According to an example not shown, in the long sections of pipe 12, several insulating elements 14 are placed end to end, the junctions between two consecutive insulating elements 14 being closed by the vapor barrier 20, so as to prevent the penetration of humidity.

[0026] The installation of the heat transfer network 10, in particular the installation of the insulating elements 14 on the pipe 12, is generally carried out at ambient temperature, denoted Ti. The insulating elements 14 tend to change dimension as a function of a temperature difference AT between the installation temperature Ti and the operating temperature Tu of the heat transfer network, in other words they tend to expand. Thus, for a refrigeration network, the temperature difference AT= Ti -Tu is of the order of -200°C, which causes a contraction of the insulating elements. As an illustrative example, for each meter along the pipe 12, an insulating element 14 made of PIR tends to contract by approximately 2.5 mm for a temperature difference AT of the order of -200°C.

[0027] When two consecutive insulating elements 14 contract, their facing ends tend to move away from each other, and the vapor barrier 20 closing Injunction corresponding to these two ends is mechanically stretched, which risks generating cracks in the vapor barrier 20, which is not desirable.

[0028] To solve this problem, the heat transfer network 10 comprises an expansion joint 100, which is interposed between two insulating elements 14, as shown in [Fig. 1]. The expansion joint 100 is shown in isolation in [Fig. 2].

[0029] The expansion joint 100 comprises a main body 102 generally having a tube shape, which extends along a longitudinal axis A100. The main body 102 has a cavity VI02 configured to receive the pipe 12. When the pipe 12 is received in the cavity V102, the expansion joint 100 is in a use configuration, in which the longitudinal axis A100 coincides with the main axis A12. The longitudinal axis A100 defines an axial direction of the expansion joint 100. A radial direction to the expansion joint 100 is a direction orthogonal to the longitudinal axis A100.

[0030] The body 102 has two end portions 104A and 104B, the cavity V102 opening out of each of the two end portions 104A and 104B via two respective openings 106A and 106B.

[0031] The body 102 comprises a central portion 108, which is interposed between the two end portions 104A and 104B along the longitudinal axis A100 and which is secured to each of the end portions 104A and 104B.

[0032] The main body 102 is made of a thermally insulating material. In other words, each of the portions of the main body 102, here the two end portions 104A and 104B and the central portion 108, is made of a thermally insulating material. Preferably, the main body 102 is made of a cellular material, preferably with closed cells, to prevent the penetration of moisture.

[0033] The central portion 108 is made of a flexible insulating material. By “flexible” is meant here “elastically deformable”. Advantageously, the central portion 108 is made of a flexible elastomeric foam, preferably based on synthetic rubber. Such a material is also known by the acronym FEF, for Flexible elastomeric foam. Examples of flexible elastomeric foam include ethylene propylene diene monomer rubber, noted EPDM, as well as styrene-butadiene rubber, noted SBR.

[0034] Compared to the central portion 108, the two end portions 104A and 104B are made of a relatively rigid material. Thus, the material of the central portion 108 is more flexible than the material of each of the end portions 104A and 104B and has a modulus of elasticity at least 10 times greater than a modulus of elasticity, preferably at least 50 times greater.

[0035] Thus, when a longitudinal compressive force, parallel to the longitudinal axis A100, is applied to each of the end portions 104A and 104B, then the portion central portion 108 tends to deform elastically, while the deformation of the end portions 104A and 104B is neglected.

[0036] Advantageously, the end portions 104A and 104B each have a thermal conductivity X less than or equal to 0.050W / m2-K, preferably less than or equal to 0.040W / m2-K, more preferably less than or equal to 0.030W / m2-K. Advantageously, the end portions 104A and 104B each have a compressive strength greater than or equal to 50 kPa, preferably greater than or equal to 70 kPa, more preferably greater than or equal to 80 kPa.

[0037] Preferably, the end portions 104A and 104B are made of the same material, in particular PIR. Alternatively, the end portions 104A and 104B are made of extruded polystyrene.

[0038] During the manufacture of the main body 102, the central portion 108 is secured to each of the end portions 104A and 104B, in particular by gluing. This operation is carried out in the factory, in particular the gluing faces of the central portion 108 and the gluing faces of the end portions 104A and 104B which are glued to each other are cut using machine tools, which guarantees the geometry of the gluing faces, in particular compared to the traditional situation where an installer cuts on site a sleeve made of flexible material to insert it between two insulating elements. In addition, the conditions of the gluing operation, carried out in the factory, are controlled, which guarantees the quality of the gluing despite the difference in the materials of the central portion 108 and the end portions 104A and 104B.In particular, thanks to the factory bonding of the central portion 108 to the two end portions 104A and 104B, the risks of detachment are avoided when the body 102 is subjected to slight traction along the longitudinal axis A100, this situation being able to occur when the expansion joint 100 is part of a refrigeration network, as explained later.

[0039] When the end portions 104A and 104B move toward or away from each other, the central portion 108 elastically deforms and a length of the central portion 108, measured parallel to the longitudinal axis A100, changes.

[0040] In the illustrated example, it is planned to install one example of the expansion joint 100 every ten meters along the straight sections of the pipe 12, also the central portion 108 is configured to accommodate, by elastic deformation, a dimensional variation in compression greater than or equal to 45 mm, and a dimensional variation in extension greater than or equal to 5 mm. Thus the central portion 108 has a longitudinal dimension sufficient to accommodate, by elastic deformation, a dimensional variation in compression greater than or equal to 45 mm, and a dimensional variation in extension greater than or equal to 5 mm.

[0041] The main body 102 is split along the longitudinal direction, so as to allow the passage of the pipe 12 between an outer side of the expansion joint 100 and cavity V102.

[0042] Preferably, the main body 102 comprises two longitudinal slots, which include a first slot 111 and a second slot 112, the first slot 111 and the second slot 112 being different from each other. Each of the first slot 111 and second slot 112 connects the two mouths 106A & 106B to each other, dividing the main body 102 into two shells 121 and 122. The shells 121 and 122 have shapes complementary to each other, which are configured to be assembled to each other to form the main body 102, delimiting the cavity V102, the expansion joint 100 then being in the use configuration.

[0043] The expansion joint 100 advantageously comprises a vapor barrier membrane 130, which surrounds the main body 102, so as to prevent the penetration of moisture through the longitudinal slots 111 and 112. Preferably, the vapor barrier membrane 130 is self-adhesive, so as to facilitate the assembly of the two shells 121 and 122. Preferably, the vapor barrier membrane 130 is capable of absorbing shear forces when a length of the central portion 108, measured parallel to the longitudinal axis A100, changes, in particular when the end portions 104A and 10B move towards or away from each other.

[0044] The vapor barrier membrane 130 is here a complex comprising a layer of aluminum, which is reinforced on at least one face, preferably on both faces, by a polyester fabric, the aluminum and polyester fabric assembly being coated, on one face, with a butyl rubber adhesive. With reference to Figure 2a), during the manufacture of the expansion joint 100, the two shells 121 and 122 are advantageously connected to each other by the vapor barrier membrane 130 at one of the longitudinal slots 111 or 112, so as to form a hinge 131 between the two shells 121 and 122, which facilitates the handling of the two shells 121 and 122 during the installation of the expansion joint 100 on the pipe 12. The hinge 131 is thus formed by a portion of the vapor barrier membrane 130. In the example illustrated, the hinge 131 is located at the first slot 111.

[0045] Preferably, the vapor barrier membrane 130 comprises an adhesive flap 132, which extends from that of the two slots 111 or 112 which is not located in the vicinity of the hinge 131, the flap 132 being configured to immobilize the two shells 121 and 122 relative to each other once the installer has positioned the expansion joint 100 on the pipe 12. The flap 132 extends here from an external edge of the face 1121 of the second slot 112 belonging to the first shell 121.

[0046] With reference to [Fig. 2], each longitudinal slot 111 or 112 provides two edges which are located opposite each other and which each belong to a respective shell 121 or 122. Thus the first slot 111 provides a first edge 1111 which belongs to the first shell 121, and a second edge 1112 which belongs to the second shell 122. Similarly, the second slot 112 provides a first edge 1121 which belongs to the first shell 121, and a second edge 1122 which belongs to the second shell 122. For each of the longitudinal slots 111 and 112, the two associated edges have complementary shapes, preferably identical, apart from assembly clearances.

[0047] Each longitudinal slot 111 and 112 advantageously provides a longitudinal rebate 113. By longitudinal rebate 113, it is meant that each edge 1111 / 1112 / 1121 / 1122 is not geometrically carried by a single respective plane radial to the longitudinal axis A100, but comprises portions forming angles with respect to each other, so as to reduce thermal bridges by lengthening a conduction path through the longitudinal slots 111 and 112. In the non-limiting example of FIG. 2a, each longitudinal rebate 113 comprises, from the cavity V102 towards the outside of the main body 102, a first portion 113A carried by a first plane radial to the longitudinal axis A100, a second portion 113B carried by a cylindrical surface with a circular section centered on the longitudinal axis A100, and a third portion 113C carried by a second plane radial to the longitudinal axis A100.The longitudinal grooves 113 make it possible to reduce thermal bridges and facilitate the centering of the shells 121 and 122 during the assembly of the shells 121 and 122. Preferably, the first slot 111 and the second slot 112 are arranged symmetrically to the longitudinal axis A100, so that the first shell 121 has the same shape as the second shell 122, which facilitates the manufacture of the shells 121 and 122.

[0048] In a variant not illustrated, the main body 102 comprises a single longitudinal slot, the body 102 being configured to accommodate, in particular by elastic deformation, the passage of the pipe 12 between the outer side of the expansion joint 100 and the cavity V102. According to another variant not illustrated, it is possible to provide three longitudinal slots, or even more, but this tends to complicate the manufacture and installation of the expansion joint 100, the main body 102 comprising two longitudinal slots 111 and 112 being preferred, as in the example illustrated.

[0049] More generally, the main body 102 comprises at least one longitudinal slot, which connects the two mouths 106A & 106B to each other, each longitudinal slot being arranged so as to accommodate the passage of the pipe 12 between the outer side of the expansion joint 100 and the cavity V102.

[0050] Advantageously, each of the end portions 104A and 104B has a circumferential rebate 105, each circumferential rebate 105 being configured to cooperate, in particular by complementarity of shapes, with an insulating element 14 placed opposite, so as to facilitate assembly and to limit thermal bridges through the junctions between the expansion joint 100 and the insulating elements 14. In the first embodiment, each circumferential rebate 105 comprises, from the cavity V102 towards the outside of the expansion joint 100, a first radial portion 105A, which has a ring shape extending in a plane transverse to the main axis A100, a second portion 105B having a cylinder shape with a circular section centered on the main axis A100, and a third radial portion 105C, which has a ring shape extending in a plane transverse to the main axis A100. The second portion 105B connects the first portion 105A to the third portion 105C, as shown in section in Figures 1 and 3a). The circumferential rebate 105 here has a female shape, configured to receive a male end 15 of the insulating elements 14.

[0051] We now describe the installation of the expansion joint 100 on the pipe 12 of the heat transfer network 10, in particular between the two insulating elements 14. We consider that the installation is carried out at ambient temperature, i.e. approximately 20°C.

[0052] The expansion joint 100 is initially in the configuration of FIG. 2a). The two insulating elements 14 are located at a distance from each other, so that when the expansion joint 100 is positioned between the two insulating elements 14, the main body 102 is slightly compressed. In particular, the central portion 108 deforms elastically to accommodate the bringing together of the two end portions 104A and 104B. Thus, by elastic return of the central portion 108, the two end portions 104A and 104B bear against the insulating elements 14 located opposite each other.

[0053] The end portions 104A and 104B are advantageously bonded to the facing insulating elements 14, for example using an adhesive product such as a mastic, in particular a butyl mastic, which is applied to the surfaces of each of the circumferential rebates 105. The adhesive product is not shown. The insulating elements 14 and the end portions 104A and 104B being each made of rigid materials, the bonding is easy and effective, even when it is carried out “on site” and not in the factory.

[0054] Similarly, preferably an adhesive product such as a mastic, in particular a butyl mastic, is applied to the edges 1111 / 1112 / 1121 / 1122 of the longitudinal slots 111 and 112 when the expansion joint 100 is placed on the pipe 12, so as to seal the longitudinal slots 111 and 112 and reduce thermal bridges.

[0055] The flap 132 is advantageously closed as soon as the expansion joint 100 is put in place, so as to immobilize the two shells 121 and 122 relative to the insulating elements 14 while the adhesive product polymerizes.

[0056] The surfaces of the circumferential grooves 105 and the male ends 15 being manufactured in the factory, the dimensional tolerances are reduced, in particular in com comparison of a manual cut carried out on site, which facilitates assembly and durability of the bonding. Once the adhesive product is sufficiently polymerized, the bonding is completed and it is considered that each of the end portions 104A and 104B is integral with the facing insulating element 14. Similarly, thanks to the reduced dimensional tolerances, the adhesive product also serves as a seal. In addition, a strip 134 of vapor barrier is applied straddling the insulating elements 14 and the facing end portions 104A and 104B, so as to further reduce the risks of moisture penetration between the insulating elements 14 and the facing end portions 104A and 104B.

[0057] Thus, once the heat transfer network 10 is in operation and the temperature of the pipe 12 changes, the dimensional variations of the insulating elements 14 are mainly, or even entirely, transmitted to the end portions 104A and 104B, which move closer or further apart, depending on the sign of the temperature difference AT.

[0058] The movements of the end portions 104A and 104B along the longitudinal axis A100 are compensated by elastic deformation of the central part 108, which is comparatively more flexible than the end portions 104A and 104B. Thus, despite the expansion or contraction movements of the insulating elements 14, linked to changes in temperature, the expansion joint 100 makes it possible to compensate for these dimensional variations while guaranteeing continuity of the insulation, without creating thermal bridges due to a possible separation of the expansion joint 100 and the insulating elements, following for example defective bonding.

[0059] On the other hand, the vapor barrier membrane 130, chosen to accommodate the dimensional variations of the main body 102, and in particular of the main portion 108, makes it possible to prevent, in a lasting manner, the risks of moisture penetration.

[0060] With reference to insert a) of [Fig. 3], the expansion joint 100 of the first embodiment comprises, for each of the end portions 104A and 104B, a circumferential rebate 105 having a female shape.

[0061] Alternative embodiments of the invention are illustrated in inserts b) and c) of [Fig. 3]. In the alternative embodiments of the invention, elements similar to those of the other embodiments bear the same references and operate in the same way. In the following, the differences between each embodiment and the previous one(s) are mainly described.

[0062] An expansion joint 200 according to a second embodiment of the invention is shown in insert b) of [Fig.3].

[0063] Compared to the expansion joint 100 of the first embodiment, the expansion joint 200 of the second embodiment has, for one of the end portions, a circumferential rebate 205 of a shape complementary to the rebate circumferential 105 of the expansion joint 100 according to the first embodiment. In other words, the expansion joint 200 according to the second embodiment comprises, at one end, a circumferential rebate 105 with a female shape, and at the other end a circumferential rebate 205 of male shape.

[0064] An expansion joint 300 according to a third embodiment of the invention is shown in insert c) of [Fig. 3]. The expansion joint 300 comprises, at each of the two ends, a circumferential rebate 205 of male shape.

[0065] In a variant not shown, one of the end portions 104A or 104B does not comprise a circumferential rebate, but has a ring-shaped surface, which is geometrically carried by a plane orthogonal to the longitudinal axis A100.

[0066] More generally, it is understood that multiple combinations are possible, to adapt to the shapes of the ends of the available insulating elements 14.

[0067] Any feature described for one embodiment or variation in the foregoing may be implemented for the other embodiments and variations described above, as long as technically feasible.

Claims

Claims

1. Expansion joint (100; 200; 300), configured to isolate a portion of a pipe (12) from a heat transfer network (10), in which: • the expansion joint comprises a main body (102) generally having a tube shape, which extends along a longitudinal axis (A 100), which forms a cavity (V102) configured to receive the pipe (12) and which has two end portions (104A, 104B), the cavity (V102) opening from each of the two end portions (104A, 104B) by a respective mouth (106A, 106B), • the main body (102) is made of a thermally insulating material, • the main body (102) comprises at least one longitudinal slot (111, 112), which connects the two mouths (106A, 106B) to each other, each longitudinal slot (111, 112) being arranged so as to accommodate the passage of the pipe (12) between an outer side of the expansion joint and the cavity (V102),in which: • the main body (102) comprises a central portion (108), which is interposed between the two end portions (104A, 104B) along the longitudinal axis (A100) and which is secured to each of the end portions (104A, 104B), • the central portion (108) is made of a material that is more flexible than a material of each of the end portions, the material of the central portion (108) having a modulus of elasticity at least 10 times greater than a modulus of elasticity of the material of each of the end portions (104A, 104B), preferably at least 50 times greater.,

2. Expansion joint (100; 200; 300) according to claim 1, in which: • the central portion (108) is made of an elastomeric synthetic rubber foam, for example EPDM or SBR.

3. Expansion joint (100; 200; 300) according to any one of claims 1 or 2, in which: • the central portion (108) has a longitudinal dimension sufficient to accommodate, by elastic deformation, a dimensional variation in compression greater than or equal to 45 mm, and a dimensional variation in extension greater than or equal to 5 mm.

4. Expansion joint (100; 200; 300) according to any one of claims 1 to 3, in which: • each of the end portions (104A, 104B) is made of a synthetic polymer cellular material, for example extruded polystyrene or polyisocyanurate.

5. Expansion joint (100; 200; 300) according to any one of claims 1 to 4, wherein: • the at least one longitudinal slot (111, 112) includes a first slot (111) and a second slot (112), which are different from each other, the first slot and the second slot dividing the main body (102) into two shells (121, 122), which have shapes complementary to each other and which are configured to be assembled to each other to form the cavity (V102), the expansion joint (100; 200; 300) then being in a use configuration.

6. Expansion joint (100; 200; 300) according to claim 5, in which: • each longitudinal slot (111, 112) provides a longitudinal rebate (113).

7. Expansion joint (100; 200; 300) according to any one of claims 1 to 6, wherein: • the expansion joint (100; 200; 300) also comprises a vapor barrier membrane (130), which surrounds the main body (102), • the vapor barrier membrane (130) is configured to absorb shear forces when a length of the central portion (108) changes.

8. Expansion joint (100; 200; 300) according to any one of claims 1 to 7, in which: • each of the end portions (104A, 104B) has a circumferential groove (105; 205), configured to cooperate, in particular by complementarity of shapes, with an insulating element (14) of the heat transfer network (10) located opposite.

9. Heat transfer network (10), comprising: • a pipe (12) comprising two insulated portions (13A, 13B), • two insulating elements (14), each insulated portion being respectively covered with one of the two insulating elements, • the expansion joint (100; 200; 300) according to any one of the preceding claims, the expansion joint being interposed between the two insulating elements (13A, 13B).

10. Heat transfer network (10) according to claim 9, in which: • the two end portions (104A, 104B) are bonded to the facing insulating elements (14), • the central portion (108) is elastically deformable, so as to compensate for the movements of the two end portions (104A, 104B), along the longitudinal axis (A100), under the effect of the dimensional variations of the insulating elements (14).

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