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 is generally tube-shaped and extends along a longitudinal axis (A100). This body is made of a thermally insulating material and includes two end portions (104A, 104B). The main body (102) includes a central portion (108), which is interposed between the two end portions (104A, 104B) along the longitudinal axis (A100) and is fixed 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 the abridged version: 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] This discussion focuses on pipe networks configured to transport hot or cold fluids, generically referred to as heat transfer networks. Once in operation, the pipes have a temperature substantially equal to the temperature of the fluid being transported, for example, down to -180°C in the case of a refrigeration network, or +120°C or even higher in the case of a heating network. In some cases, the heat transfer network is reversible, and the temperature of the transported fluid changes depending on the application, for example, between -50°C and +120°C. The pipes are generally insulated using elements made of insulating material, often in the form of shells. These insulating elements are assembled around the pipes to reduce heat loss from the fluids circulating within them.

[0003] In many cases, particularly in the case of a refrigeration network, the insulating elements are coated on one side with a vapor barrier, which prevents water vapor from penetrating 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] Insulating elements are generally installed during the installation of the heat transfer network, while the pipes are still at ambient temperature, for example, around 20°C. Due to the difference 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 insulating elements expand, i.e., undergo dimensional changes that depend on the sign of the temperature difference. This leads to the appearance of tensile or compressive stresses in the insulating elements, depending on the sign of the temperature difference. These stresses tend to damage the vapor barrier and create gaps between the insulating elements, potentially allowing moisture to penetrate, which is undesirable.

[0005] It is known to insert an insulating sleeve between two insulating elements, the insulating sleeve being, for example, cut on site to the required dimensions from a block of elastomeric foam or mineral wool. Manufacturing and installing the sleeve is time-consuming. Furthermore, it is difficult to obtain a good fit between the sleeve and the adjacent insulating elements, which creates thermal bridges. which is not desirable.

[0006] It is these problems that the invention intends to remedy in particular, by proposing an expansion joint which allows to accommodate the 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 in a heat transfer network, in which: - the expansion joint comprises a main body generally shaped like a tube, extending along a longitudinal axis, which provides a cavity configured to receive the pipe and which has two end portions, the cavity opening from each of the two end portions by a respective mouth, - the main body is made of a thermally insulating material, - the main body includes at least one longitudinal slot, which connects one to The other has two openings, each longitudinal slot arranged to accommodate the passage of the pipe between an outer 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 attached 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 manufactured 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 installed on a pipe between two insulating elements, the end portions of the expansion joint come into contact with the insulating elements, which have similar or even identical hardness to the end portions, thus facilitating their assembly and bonding. As a result, the expansion joint remains bonded to the insulating elements even when the heat transfer network is a refrigeration network and the insulating elements contract, thereby preventing the formation of thermal bridges.

[0010] According to advantageous but not mandatory aspects of the invention, such an expansion joint may incorporate one or more of the following features taken individually or in any technically permissible 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 together to form the cavity, the expansion joint then being in a configuration of use. - Each longitudinal slot creates 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 rebate, configured to cooperate, in particular by complementary 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 sections, - 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 bonded to the opposing 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 dimensional variations in the insulating elements.

[0013] The invention will be better understood, and other advantages thereof will become clearer in light of the following description of several configurations of an expansion joint, a heat transfer network, and an installation method, conforming to its principle, given solely by way of non-limiting example and with reference to the accompanying drawings, in which:

[0014] - [Fig. 1] [Fig. 1] 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 di joint latation of [Fig.1] shown in perspective in a mounting configuration, and a cross-section of the expansion joint along plane IIb in [Fig.1], 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.1], 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. 1]. The heat transfer network 10 comprises a pipe 12, which here has the form of a straight tube and extends along a principal axis A12. In typical examples, the pipe 12 is made of metal, or of polyvinyl chloride (PVC), or even of a multilayer material, that is to say, a complex of several superimposed layers. The pipe 12 is configured to allow the passage of a fluid, for example, a gas or a liquid. The fluid is not shown.

[0018] Depending on the application, the fluid passing through the heat transfer network 10 is at a temperature higher than the ambient temperature, for example, +80°C or +120°C. The heat transfer network 10 is then called a "heating network." Ambient temperature refers to the temperature of the surrounding air, for example, around 20°C. In some applications, the fluid passing through the heat transfer network 10 is at a temperature lower than the ambient temperature, for example, -180°C. The heat transfer network 10 is then called a "cooling network." In some applications, the temperature of the fluid changes according to the 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 according to the operating temperature(s) of the heat transfer network 10, this aspect not being detailed further in the context of this description. The fluid is also referred to as the "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. 1], the pipe 12 comprises two insulated sections 13A and 13B, the heat transfer network 10 comprising two insulating elements 14, each insulated section 13A / 13B being respectively covered by one of the two insulating elements 14. The insulating elements 14 each have a tube shape, into which the pipe 12 is received.

[0021] A material is considered here 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, and preferably even less than 0.040 W / m2-K. The thermal conductivity is evaluated at 10°C.

[0022] In the context of heat transfer systems 10 designed to transport a fluid at negative temperatures, particularly refrigeration systems and reversible systems, insulating materials in the form of a cellular material, i.e., a foam, preferably with closed cells to prevent moisture penetration, which would degrade insulation performance over time, are preferred. Preferably, the insulating materials used are rigid, i.e., they have a compressive strength, expressed in kPa (kilopascals) 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 - denoted XPS -, which has a thermal conductivity X typically between 0.030 and 0.035 W / m2-K, or polyisocyanurate - denoted 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 that prevents the passage of moisture. For example, the vapor barrier 20 is in the form of a roll of aluminum foil laminated onto a flexible substrate, for example polyester, and having an adhesive side. The vapor barrier 20 is thus applied in a spiral around the insulating elements 14 positioned on the pipe 12, so as to create 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 sealed by the vapor barrier 20, so as to prevent the penetration of moisture.

[0026] The installation of the heat transfer network 10, in particular the placement 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 dimensions according to 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 on the order of -200°C, which causes the insulating elements to contract. As an illustrative example, for each meter along the pipe 12, a PIR insulating element 14 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 opposite ends tend to move away from each other, and the vapor barrier 20 seals the gap. 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 includes 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 tube-shaped, extending along a longitudinal axis A100. The main body 102 has a cavity V102 configured to receive the conduit 12. When the conduit 12 is received in the cavity V102, the expansion joint 100 is in a working 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 from each of the two end portions 104A and 104B by two respective mouths 106A and 106B.

[0031] The body 102 includes a central portion 108, which is intercalated 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 moisture penetration.

[0033] The central portion 108 is made of a flexible insulating material. "Flexible" here means "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, abbreviated EPDM, and styrene-butadiene rubber, abbreviated 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, preferably at least 50 times greater than, a modulus of elasticity.

[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 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 0.050 W / m²-K, preferably less than or equal to 0.040 W / m²-K, and preferably less than or equal to 0.030 W / 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, and 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 joined to each of the end portions 104A and 104B, in particular by bonding. This operation is carried out in the factory; specifically, the bonding surfaces of the central portion 108 and the bonding surfaces of the end portions 104A and 104B, which are bonded to each other, are cut using machine tools. This ensures the geometry of the bonding surfaces, particularly compared to the traditional situation where an installer cuts a sleeve of flexible material on-site to insert it between two insulating elements. Furthermore, the conditions of the bonding operation, carried out in the factory, are controlled, which guarantees the quality of the bond despite the difference in materials between 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 risk of detachment is avoided when the body 102 is subjected to slight tension along the longitudinal axis A100, a situation which can occur when the expansion joint 100 is part of a refrigeration network, as explained later.

[0039] When the end portions 104A and 104B move closer to or further away from each other, the central portion 108 deforms elastically 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 of the expansion joints 100 every ten meters along the straight sections of the pipe 12; therefore, 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, including 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 complementary shapes, which are configured to be assembled together to form the main body 102, delimiting the cavity V102, the expansion joint 100 then being in the operating configuration.

[0043] The expansion joint 100 advantageously comprises a vapor barrier membrane 130, which surrounds the main body 102, so as to prevent moisture penetration 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 closer to or further away from each other.

[0044] The vapor barrier membrane 130 is here a complex comprising an aluminum layer, 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 when installing 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 illustrated example, the hinge 131 is located at the first slot 111.

[0045] Preferably, the vapor barrier membrane 130 includes 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 slit 111 or 112 forms two edges which are situated opposite each other and which each belong to a respective shell 121 or 122. Thus, the first slit 111 forms 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 slit 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 slits 111 and 112, the two associated edges have complementary shapes, preferably identical, except for the assembly rules.

[0047] Each longitudinal slot 111 and 112 advantageously provides a longitudinal rebate 113. By longitudinal rebate 113, it is understood that each edge 1111 / 1112 / 1121 / 1122 is not geometrically supported by a single 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 Figure 2a, each longitudinal rebate 113 comprises, from the cavity V102 outwards from the main body 102, a first portion 113A supported by a first plane radial to the longitudinal axis A100, a second portion 113B supported by a cylindrical surface with a circular cross-section centered on the longitudinal axis A100, and a third portion 113C carried by a second radial plane to the longitudinal axis A100.The longitudinal rebates 113 reduce thermal bridging 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 an alternative not shown, the main body 102 comprises a single longitudinal slot, the body 102 being configured to accommodate, notably by elastic deformation, the passage of the conduit 12 between the outer side of the expansion joint 100 and the cavity V102. According to another alternative not shown, it is possible to provide three or more longitudinal slots, 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 illustrated example.

[0049] More generally, the main body 102 includes at least one longitudinal slot, which connects the two mouths 106A & 106B to each other, each longitudinal slot being arranged to accommodate the passage of the conduit 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 complementary shapes, with an insulating element 14 placed opposite it, so as to facilitate assembly and limit thermal bridges through the junctions between the expansion joint 100 and the insulating elements 14. In the In the first embodiment, each circumferential rebate 105 comprises, from the cavity V102 outwards from 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 cylindrical shape with a circular cross-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 cross-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] 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, is now described. The installation is assumed to be at ambient temperature, i.e. approximately 20°C.

[0052] The expansion joint 100 is initially in the configuration shown in Figure 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 coming 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 opposing insulating elements 14.

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

[0054] Similarly, preferably an adhesive product such as a sealant, in particular a butyl sealant, is applied to the edges 1111 / 1112 / 1121 / 1122 of the longitudinal slots 111 and 112 when installing the expansion joint 100 on the pipe 12, so as to close 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 in place, so as to immobilize the two shells 121 and 122 in relation to the insulating elements 14 while the adhesive product polymerizes.

[0056] Since the surfaces of the circumferential rebates 105 and the male ends 15 are manufactured in the factory, the dimensional tolerances are reduced, particularly in com Comparison with a manual cut made on site, which facilitates assembly and ensures the durability of the bond. Once the adhesive has sufficiently cured, the bonding is complete, and each of the end portions 104A and 104B is considered to be integral with the opposing insulating element 14. Similarly, thanks to the reduced dimensional tolerances, the adhesive also serves as a seal. In addition, a vapor barrier strip 134 is applied across the insulating elements 14 and the opposing end portions 104A and 104B, in order to further reduce the risk of moisture penetration between the insulating elements 14 and the opposing 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 together 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 temperature changes, the expansion joint 100 makes it possible to compensate for these dimensional variations while ensuring continuity of the insulation, without creating thermal bridges due to possible separation of the expansion joint 100 and the insulating elements, for example following 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 durable 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 insets b) and c) of [Fig. 3]. In the alternative embodiments of the invention, the elements analogous to those of the other embodiments bear the same reference numerals and function in the same way. The following primarily describes the differences between each embodiment and the preceding one(s).

[0062] An expansion joint 200 according to a second embodiment of the invention is shown in inset 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 its 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 with a male shape.

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

[0065] In an alternative not shown, one of the end portions 104A or 104B does not include a circumferential rebate, but has a ring-shaped surface, which is geometrically supported 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 an embodiment or variant in the foregoing may be implemented for the other embodiments and variants described above, provided that it is technically feasible.

Claims

Demands

1. Expansion joint (100; 200; 300), configured to isolate a portion of a pipe (12) from a heat transfer network (10), wherein: • the expansion joint comprises a main body (102) having an overall tube shape, extending along a longitudinal axis (A100), which provides 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 opening (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 one on the other side the two openings (106A, 106B), each longitudinal slot (111, 112) being arranged to accommodate the passage of the conduit (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 fixed to each of the end portions (104A, 104B), • the central portion (108) 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.

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

3. Expansion joint (100; 200; 300) according to any one of claims 1 or 2, wherein: • 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, wherein: • 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: • 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 complementary shapes to each other and which are configured to be assembled together to form the cavity (V102), the expansion joint (100; 200; 300) then being in a configuration for use.

6. Expansion joint (100; 200; 300) according to claim 5, wherein: • 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, wherein: • each of the end portions (104A, 104B) has a circumferential rebate (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 by 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, wherein: • the two end portions (104A, 104B) are glued to the insulating elements (14) opposite, • 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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