Thermoacoustic machine comprising a baffle heat exchanger

Abstract

Thermoacoustic machine comprising a heat exchanger (12) which comprises a body (22) and a cover (23) configured to be arranged on a lateral surface of the body (22). The cover (23) comprises deflectors (46) configured to alternate the direction of flow of a heat transfer fluid in a network of channels formed by the body (22) of the heat exchanger (12). Figure for abstract: Fig. 3

Description

Title of the invention: Thermoacoustic machine comprising a baffle heat exchanger Technical field

[0001] The invention relates to the field of thermoacoustic machines. State of the prior art

[0002] A thermoacoustic machine is a thermal machine producing, according to the physical principle of thermoacoustics, thermodynamic cycles within a working fluid such as helium. In an engine-type operating mode, the cycles generate mechanical energy in the form of an acoustic wave from a heat input. Conversely, in a heat pump-type operating mode, the cycles generate heat pumping using the mechanical energy of an acoustic wave.

[0003] Generally, a thermodynamic machine comprises a waveguide containing the working fluid for propagating the acoustic wave and one or more thermoacoustic cells each provided with a porous structure arranged between two heat exchangers so as to carry out a thermoacoustic energy conversion. Statement of the invention

[0004] The invention aims to improve the efficiency of a thermoacoustic machine.

[0005] For this purpose, the invention relates to a thermoacoustic machine comprising at least one heat exchanger, the heat exchanger comprising a body having a lateral surface which extends around a central axis, the body comprising: - first channels configured to conduct a first fluid through the body, along the central axis, - second channels configured to conduct a second fluid into the body in order to carry out a heat exchange between the first fluid and the second fluid, each of the second channels extending along a transverse direction and comprising a first end and a second end each opening onto the lateral surface of the body.

[0006] The heat exchanger comprises a cover configured to be disposed on the lateral surface of the body and comprising one or more deflectors configured to alternate a direction of flow of the second fluid from one of said second channels to another of said second channels.

[0007] The cover thus forms a baffle structure making it possible to optimize the circulation of the second fluid in the body and its distribution.

[0008] The invention thus makes it possible to improve the heat exchange between the first fluid and the second fluid and to reduce the pressure losses of the second fluid in the body of the exchanger.

[0009] For information purposes, the first fluid may comprise a gas such as helium.

[0010] The first fluid can form a working fluid, in particular when the heat exchanger equips a thermoacoustic machine.

[0011] The second fluid may be a heat transfer fluid such as water.

[0012] According to a first variant embodiment, one or more of said deflectors circumferentially delimit between them cavities establishing fluid communication between two respective second channels.

[0013] For this purpose, the deflector(s) concerned may each extend substantially along said central axis.

[0014] According to a second variant embodiment, one or more deflectors axially delimit between them cavities establishing fluid communication between two respective second channels.

[0015] For this purpose, within the framework of this second variant, the deflector(s) concerned may each extend around said central axis.

[0016] These variants can be combined. Thus, in a non-limiting manner, the cover can comprise one or more deflectors according to the first variant and one or more deflectors according to the second variant.

[0017] Each of the deflectors may be configured to prevent fluid communication either between the first ends of two respective second channels or between the second ends of two respective second channels.

[0018] In one embodiment, the cover comprises a main wall extending opposite the first end and / or the second end of one or more of said second channels.

[0019] In this embodiment, it is preferred that the deflectors extend radially between said main wall of the cover and the lateral surface of the body.

[0020] According to a first variant embodiment, the cover comprises a first side and a second side.

[0021] In a non-limiting manner, the first flank may be arranged opposite the first end of the second channels and the first flank may be arranged opposite the second end of the second channels.

[0022] According to a second variant embodiment, the cover is a single-piece part.

[0023] In one embodiment, the cover comprises an inlet port configured to allow introduction of the second fluid into at least one of the second channels and an outlet port configured to extract the second fluid from the body.

[0024] In one embodiment, the side surface may extend circumferentially around the central axis.

[0025] In particular, the lateral surface of the body may be a surface of revolution of said central axis.

[0026] Alternatively, the lateral surface may have another geometry, for example a polygonal or other section.

[0027] The body preferably comprises two transverse surfaces, spaced from each other along the central axis.

[0028] In one embodiment, the first channels each have an inlet opening onto one of said transverse surfaces and an outlet opening onto the other of said transverse surfaces.

[0029] The body may comprise a passage section of the first fluid formed by the first channels.

[0030] The passage section can define a porosity, in other words a percentage of opening achieved by said first channels, which is preferably between 30% and 45%, more preferably between 35% and 40%, for example equal to 38%.

[0031] In a non-limiting manner, the passage section is preferably circular.

[0032] In one embodiment, the body comprises fins forming the first channels and conduit elements forming the second channels.

[0033] The driving elements may be of the tube type.

[0034] In one embodiment, the body comprises a plurality of rows of first channels each formed by a plurality of respective first channels and a plurality of rows of second channels each formed by a plurality of respective second channels.

[0035] Preferably, the rows of first channels are arranged alternately with the rows of second channels in a transverse direction.

[0036] In terms of material, the body may comprise a first material, preferably a conductive metal such as aluminum.

[0037] The cover may comprise a second material, for example an elastomer, a resin or a plastic.

[0038] In a non-limiting manner, the second material may comprise an ethylene-propylene-diene monomer, for example of hardness 70 Shore A.

[0039] Such a material makes it possible in particular to reduce the risks of thermal and fluid leaks.

[0040] According to another aspect, the invention relates to a method of manufacturing a thermoacoustic machine as defined above.

[0041] The method preferably comprises a step of fixing the cover to the body of the heat exchanger.

[0042] Other advantages and characteristics of the invention will appear on reading the detailed, non-limiting description which follows. Brief description of the drawings

[0043] The following detailed description refers to the attached drawings in which: - [Fig.l] is a schematic view of an installation comprising a thermoacoustic machine and external sources connected to heat exchangers of a thermoacoustic cell of the machine; - [Fig.2] is a schematic axial sectional view of a thermoacoustic cell comprising two heat exchangers in accordance with the invention; - [Fig.3] is a schematic perspective view of a heat exchanger according to a first embodiment of the invention, comprising a body and two sides forming a cover, [Fig.3] showing the sides of the cover separated from the body, before assembly; - [Fig.4] is a schematic cross-sectional view of the heat exchanger of [Fig.3], in assembled configuration; - [Fig.5] is a schematic view of a pipe element of the heat exchanger of [Fig.4]; - [Fig.6] is a schematic perspective and axial sectional view of a heat exchanger according to a second embodiment of the invention, comprising a body and a cover which includes deflectors extending around a central axis of the body. Detailed description of embodiments

[0044] The installation of [Fig.l] illustrates a non-limiting example of application of the invention.

[0045] This installation comprises a thermoacoustic machine 1, two external sources 2 and 3 as well as a distribution network 4 connecting the machine 1 to the external sources 2 and 3.

[0046] In this example, the thermoacoustic machine 1 is intended for operation in heat pump mode, as distinguished from operation in motor mode. In the physical sense, the heat pump mode corresponds to the use of the mechanical energy of an acoustic wave to pump energy to a thermal source, also called a pumping source, raise its temperature and then deposit it at a second thermal source, also called a discharge source, the temperature of the discharge source therefore being higher than the temperature of the pumping source.

[0047] Thus, a heat pump such as constituted by the thermoacoustic machine 1 of [Fig.l] can be used as a heating system, by increasing the temperature of one of the sources 2 and 3 forming a discharge source used as a means heating, or as a refrigeration system, by lowering the temperature of one of the sources 2 and 3 forming a pumping source used as a means of refrigeration.

[0048] In a manner known per se, the machine 1 of [Fig.l] comprises a waveguide 6, two acoustic sources 7 and 8 and a thermoacoustic cell 10 comprising a regenerator 11 and two heat exchangers 12.

[0049] In this example, the waveguide 6 is a tube of circular section defining an internal space, in a closed loop, which forms an acoustic waveguide.

[0050] The internal space of the waveguide 6 contains a pressurized working fluid for propagating an acoustic wave. The working fluid may be a monatomic gas, a polyatomic gas such as a mixture comprising helium and argon or other gas mixtures, or a mixture of liquid and gas.

[0051] In this example, the working fluid comprises helium.

[0052] Such a geometry of the waveguide 6, which is in no way limiting, makes it possible to promote the development of a progressive wave and, more specifically, to obtain locally at the level of the regenerator 11 a wave with a progressive character.

[0053] The acoustic sources 7 and 8 and the thermoacoustic cell 10 are mounted in series along the waveguide 6 in the manner schematically illustrated in [Fig.l].

[0054] In this example, each of the acoustic sources 7 and 8 comprises a linear motor provided with a movable element of the piston type, configured to be able to move its piston so as to generate a pressure wave in the working fluid and thus propagate acoustic energy in the waveguide 6.

[0055] In alternative embodiments, the acoustic sources 7 and 8 may comprise another type of actuator, for example an electroacoustic actuator, and / or an actuator equipped with another type of mobile element, for example a double-piston mobile element.

[0056] Concerning the thermoacoustic cell 10, the regenerator 11 and a part of the exchangers 12 are arranged in the waveguide 6 so as to be crossed by the working fluid in order to be able to carry out a thermoacoustic energy conversion, implementing a thermodynamic cycle.

[0057] In a manner known per se, the regenerator 11 is a porous structure, that is to say a structure provided with pores or cavities or openings making it possible to increase or maximize the contact surface and therefore the exchange surface with the working fluid while minimizing the pressure losses.

[0058] For example, the regenerator 11 may for this purpose comprise a stack of lamellae or grids, made from a material having a high heat capacity and low thermal conductivity, for example stainless steel or a ceramic material.

[0059] In operation, the regenerator 11 behaves like a thermal sponge with respect to the working fluid, alternately storing and releasing heat.

[0060] The heat exchangers 12 are arranged on either side of the regenerator 11 in order to carry out, at the ends of the regenerator 11, a heat exchange between the working fluid and a heat transfer fluid circulating in conduits 15 and 16 of the distribution network 4 and in channels 20 of the exchangers 12, the channels 20 being visible in [Fig.2] which shows an example of a similar thermoacoustic cell 10.

[0061] In the installation of [Fig. 1], the external source 2 can be a room to be heated, respectively to be cooled, and the external source 3 can be an external space constituting a thermal reservoir of air or water that is relatively cold, respectively hot, compared to the air circulating in the room.

[0062] External sources 2 and 3 thus constitute thermal reservoirs.

[0063] An embodiment of a heat exchanger 12 according to the invention and which can be implemented in such an installation will now be described with reference to FIGS. 2 to 5.

[0064] Figures 2 to 5 indicate a relative orientation of the heat exchanger(s) 12 represented therein, using a reference system defining orthogonal directions D1, D2 and D3.

[0065] With reference to [Fig.3], the heat exchanger 12 comprises a body 22 and a cover 23.

[0066] In this example, the body 22 has a generally cylindrical shape with a central axis A1 parallel to the direction D1, called the axial direction. The body 22 extends mainly along a transverse plane P1 parallel to the directions D2 and D3, called the transverse directions.

[0067] More precisely, the body 22 comprises two transverse surfaces 24 - only one being visible in [Fig.3] - which are spaced from each other along the direction D1 and which define a thickness of the body 22 (see also [Fig.2]).

[0068] The body 22 has a lateral surface 25, visible in [Fig. 4], which extends around the central axis AL. In this example, the lateral surface 25 is a surface of revolution of the axis Al and therefore extends circumferentially around the axis AL.

[0069] With reference to Figures 4 and 5, the body 22 comprises pipe elements 26, in this example sixteen pipe elements 26, which are spaced from each other along the direction D3. In [Fig.4], the pipe elements 26 are numbered 26-i (i = 1 to 16), only the pipe elements 26-1, 26-2, 26-3, 26-4 and 26-16 being indicated so as not to overload the figure.

[0070] In this non-limiting example, each of the conduit elements 26 forms a row of six of said channels 20 which are spaced from each other along the DI direction (see [Fig.5]).

[0071] Each of the channels 20 extends along the direction D2 so as to have two ends 27 and 28 which each open onto the lateral surface 25 of the body 22 (see [Fig.4], conduit element 26-1).

[0072] With reference to [Fig.4], the body 22 further comprises stacks of fins 30 which extend on either side of each of the conduit elements 26, in particular within spaces E1 delimited by the conduit elements 26 (see space E1 indicated between the conduit elements 26-1 and 26-2).

[0073] These stacks of fins 30 form channels 31 passing through the body 22 in the direction D1.

[0074] In other words, each of the channels 31 has an inlet opening onto one of the transverse surfaces 24 and an outlet opening onto the other transverse surface of the body 22.

[0075] In [Fig.4], some of said spaces E1 are shown without fins 30 and others with fins 30, for purely illustrative reasons, so as not to overload the figure.

[0076] In this embodiment, all the spaces E1 comprise stacks of fins 30 so that the channels 31 which they define form a passage section which is circular in this example.

[0077] For information purposes, the passage section formed by the channels 31 can typically define a porosity, i.e. a percentage of opening constituted by the channels 31, of the order of 35% to 40%.

[0078] The body 22 thus comprises, in this example, several rows of channels 31 which are arranged alternately in the direction D3 with the rows 26 of channels 20.

[0079] The conduit elements 26 and the fins 30 thus form a bundle of channels 20 and 31 allowing an exchange of heat between a fluid passing through the body 22 via the channels 31, in this case said working fluid, and a fluid circulating in the channels 20, in this case said heat transfer fluid which in this example is water.

[0080] With reference to Figures 3 and 4, the body 22 is in this example provided with wall elements 35 forming radial extensions of said transverse surfaces 24.

[0081] The wall elements 35 delimit between them, in the direction D1, a space E2 of annular shape extending radially around the lateral surface 25.

[0082] The invention relates more specifically to the cover 23 of the heat exchanger 12.

[0083] In the non-limiting embodiment of [Fig. 3], the cover 23 is made in two parts 41 and 42 forming in this example sides having a “C” geometry.

[0084] Each of the flanks 41 and 42 comprises a main wall 43 having a radially internal surface 44 and a radially external surface 45, which define a thickness of sides 41 and 42.

[0085] The flanks 41 and 42 are configured to be arranged on the lateral surface 25 of the body 22, being housed in the space E2 delimited by the wall elements 35, in a configuration as illustrated in [Fig.4]. In this configuration, called the assembled configuration, the external surface 45 of the flanks 41 and 42 constitutes a respective part of an external surface of the cover 23.

[0086] In this example, when the flanks 41 and 42 are thus arranged, the external surface of the cover 23 extends circumferentially around the axis A1, in a manner substantially parallel to the lateral surface 25 of the body 22.

[0087] Each of the sides 41 and 42 comprises a variable thickness by defining an alternation of hollow parts and solid parts.

[0088] With reference to [Fig. 3], the hollow parts are in this example produced by removing material and each pass through the corresponding side in the direction D1. The solid parts are here in the form of tongues 46, also called deflectors, which are consequently integral with the main wall 43.

[0089] In this example, each of the deflectors 46 extends radially inward from the main wall 43 to which they are connected and are circumferentially spaced from each other, around the central axis AL

[0090] To allow the assembly of the cover 23 with the body 22 and to ensure a sealing function, the sides 41 and 42 each have a width, that is to say a dimension along D1, which is substantially identical to the distance along D1 between the wall elements 35 of the body 22. The sealing can of course be improved by interposing sealing gaskets (not shown), for example toric gaskets, between the sides 41 and 42 and each of the wall elements 35.

[0091] In this non-limiting example, the sidewall 41 comprises eight deflectors 46, numbered 46-1 to 46-8 in [Fig.4], while the sidewall 42 comprises seven which are numbered 46-9 to 46-15 in [Fig.4].

[0092] With reference to [Fig. 4], when the cover is arranged on the lateral surface 25 of the body 22, that is to say in the assembled configuration, the flank 41 (to the right of [Fig. 4]) and more particularly the main wall 43 of this flank 41 are arranged opposite the end 27 of the channels 20. The flank 42 (to the left of [Fig. 4]) and more particularly the main wall 43 of this flank 42 are for their part arranged opposite the end 28 of the channels 20.

[0093] In the assembled configuration, each of the deflectors 46 of the sidewall 41 extends circumferentially between two respective adjacent conduit elements 26 and therefore between two respective adjacent rows 26 of channels 20. Circumferentially, the deflectors 46 of the sidewall 41 are spaced from each other so that two respective adjacent rows of channels 20 open through their end 27 into a respective one of said hollow spaces formed by this flank 41, which constitutes a portion of said space E2, also called redirection cavity. In [Fig.4], the cavities thus formed are numbered E3-2 to E3-8.

[0094] Thus, taking the cavity E3-2 as an example, it extends circumferentially between the deflectors 46-1 and 46-2, radially between the lateral surface 25 of the body 22 and the main wall 43 of the flank 41 and, in the direction D1, between the wall elements 35 of the body 22. In this example, the channels 20 of the rows 26-2 and 26-3 open via their end 27 into the cavity E3-2.

[0095] Similarly, in the assembled configuration, each of the deflectors 46 of the flank 42 extends circumferentially between two respective adjacent conduit elements 26 and therefore between two respective adjacent rows 26 of channels 20. Circumferentially, the deflectors 46 of the flank 42 are spaced from each other so that two respective adjacent rows 26 of channels 20 open by their end 28 into a respective one of said hollow spaces formed by this flank 42, which constitutes a portion of said space E2, or redirection cavity. In [Fig. 4], the cavities thus formed are numbered E3-10 to E3-17.

[0096] Thus, taking the cavity E3-16 as an example, it extends circumferentially between the deflectors 46-14 and 46-15, radially between the lateral surface 25 of the body 22 and the main wall 43 of the flank 42 and, in the direction D1, between the wall elements 35 of the body 22. In this example, the channels 20 of the rows 26-3 and 26-4 open through their end 28 into the cavity E3-16.

[0097] The same applies to the other deflectors and rows of corresponding channels, as shown in [Fig.4].

[0098] Thus, on the one hand, each of the deflectors 46 of the flank 41, respectively 42, forms an obstacle preventing fluid communication between the end 27, respectively 28, of the channels 20 of two adjacent rows 26. For example, the deflector 46-1 of the flank 41 forms an obstacle preventing fluid communication between the end 27 of the channels 20 of the rows 26-1 and 26-2.

[0099] On the other hand, the relative position of the deflectors 46 is offset in the direction D3 between the flank 41 and the flank 42. For example, the channels 20 of the rows 26-2 and 26-3 open via their end 27 into the same cavity, in this case the cavity E3-2, while they open via their end 28 into two different cavities, in this case the cavities E3-17 and E3-16, respectively.

[0100] It results from such an arrangement that, when a fluid is introduced into the network of channels 20, this fluid follows a zigzag trajectory as illustrated with arrows in [Fig.4], the deflectors 46 guiding the fluid by causing an alternation of the direction of flow from one row of channels 20 to the other.

[0101] With reference to [Fig.4], the side 41 comprises in this example an orifice inlet 51 configured to introduce the heat transfer fluid through the end 27 of the channels 20 of the row 26-1, via an inlet cavity E3-1, as well as an outlet orifice 52 configured to extract the heat transfer fluid from the body 22 through the end 27 of the channels 20 of the row 26-16, via an outlet cavity E3-9.

[0102] Thus introduced into the network of channels 20, the fluid moves in the channels 20 of the row 26-1 in a first direction of flow, in this case from the right to the left of [Fig. 4], arrives in the cavity E3-17 which directs it into the channels 20 of the row 26-2 in a second direction of flow, in this case from the left to the right of [Fig. 4], arrives in the cavity E3-2 which directs it into the channels 20 of the row 26-3 in the first direction of flow and so on until the outlet 52 of the network.

[0103] The cover 23 thus forms a baffle collector making it possible to ensure a flow of the heat transfer fluid over the entire exchange section of the body 22, improving the heat exchange with the working fluid while having low pressure losses.

[0104] For information purposes, the different parts of the body 22, i.e. the fins 30, the conduit elements 26 and the wall elements 35, may be made of a conductive metal such as copper or aluminum and assembled to each other by brazing.

[0105] The cover 23 may be made of an elastomeric material, for example an ethylene-propylene-diene monomer with a hardness of 70 Shore A.

[0106] The assembly of the body 22 and the cover 23 is in this example achieved by arranging the flanks 41 and 42 on the lateral surface 25 of the body 22, by moving the flanks 41 and 42 from a configuration such as that illustrated in [Fig.3] to the assembled configuration illustrated in [Fig.4].

[0107] Of course, numerous variations can be made to the characteristics described above and to their combination, in particular in terms of geometry and / or material of the body 22 and the cover 23 of the heat exchanger 12.

[0108] Thus, in an alternative embodiment, not shown, the cover may comprise a single part forming all of the deflectors, for example a sectioned annular-shaped part configured to be arranged on the body by deformation. According to another alternative, the cover may be made of a resin or a plastic material, for example by additive manufacturing, in particular when the cover does not need to be deformed during assembly.

[0109] In one embodiment, not shown, the deflectors of the cover can be spaced two by two so that more than two channels open into the same redirection cavity.

[0110] Furthermore, the body of the exchanger may comprise conduit elements forming a different number of rows of channels and / or number of channels per row. For example, the conduit elements may comprise two channels or a single channel (not shown).

[0111] The various channels of the body can further be formed not by assembly of parts but by machining a single piece.

[0112] In the embodiment of [Fig. 6], the cover 23 has a U-shaped section defining deflectors 46 which extend around the axis A1 of the body of the exchanger 12, circumferentially. In comparison with the deflectors in the form of tabs of the embodiment of FIGS. 2 to 5, the deflectors 46 of [Fig. 6] are configured to guide the fluid circulating in the channels 20 by causing an alternation of the direction of flow between rows of channels 20 not in the direction D3 but in the direction D1. The preceding description applies by analogy to the embodiment of [Fig. 6], which makes it possible to avoid having a transverse temperature gradient with respect to the flow of the fluid passing through the body 22 in the direction DL

[0113] For another example, the body may have another geometry, in particular a lateral surface of square, polygonal or ellipsoidal shape (not shown). Independently of the shape of its lateral surface, the body may have a non-circular passage section (not shown), adapted for example to the geometry of a non-circular waveguide, and / or have a porosity different from that indicated above, for example a porosity of between 30% and 45%.

[0114] More generally, a heat exchanger according to the invention can be implemented, in a non-limiting manner, in a thermoacoustic cell such as that illustrated in [Fig.2], in a thermoacoustic machine such as that illustrated in [Fig.1] or, alternatively, in a thermoacoustic machine comprising a different number of thermoacoustic cells and / or acoustic sources, for example in a thermoacoustic machine comprising four thermoacoustic cells and four acoustic sources (not shown).

[0115] Furthermore, the heat pump application described above is not limiting, the invention being able to be implemented in an installation intended to operate in engine mode, for example within a thermoacoustic cell comprising a stack instead of a regenerator (not shown).

Claims

Claims

1. Thermoacoustic machine (1) comprising at least one heat exchanger (12), the heat exchanger (12) comprising a body (22) having a lateral surface (25) which extends around a central axis (Al), the body (22) comprising: - first channels (31) configured to conduct through the body (22), along the central axis (Al), a first fluid, - second channels (20) configured to conduct into the body (22) a second fluid in order to carry out a heat exchange between the first fluid and the second fluid, each of the second channels (20) extending along a transverse direction (D2) and comprising a first end (27) and a second end (28) each opening onto the lateral surface (25) of the body (22),the heat exchanger (12) comprising a cover (23) configured to be arranged on the lateral surface (25) of the body (22) and comprising one or more deflectors (46) configured to alternate a direction of flow of the second fluid from one of said second channels (20) to another of said second channels (20).,

2. Thermoacoustic machine (1) according to claim 1, wherein one or more of said deflectors (46) circumferentially delimit between them cavities (E3-2 to E3-9; E3-10 to E3-17) establishing a fluid communication between two respective second channels (20).

3. A thermoacoustic machine (1) according to claim 1 or 2, wherein each of the baffles (46) is configured to prevent fluid communication either between the first ends (27) of two respective second channels (20) or between the second ends (28) of two respective second channels (20).

4. Thermoacoustic machine (1) according to any one of claims 1 to 3, wherein the cover (23) comprises a main wall (43) extending opposite the first end (27) and / or the second end (28) of one or more of said second channels (20), the deflectors (46) extending radially between said main wall (43) of the cover (23) and the lateral surface (25) of the body (22).

5. Thermoacoustic machine (1) according to any one of claims 1 to 4, in which the cover (23) comprises a first flank (41) arranged opposite the first end (27) of the second channels (20) and a second flank (42) arranged opposite the second end (28) of the second channels (20).

6. Thermoacoustic machine (1) according to any one of claims 1 to 5, wherein the lateral surface (25) of the body (22) of the heat exchanger (12) is a surface of revolution of said central axis (Al).

7. Thermoacoustic machine (1) according to any one of claims 1 to 6, wherein the body (22) of the heat exchanger (12) comprises two transverse surfaces (24), spaced from each other along the central axis (Al), the first channels (31) each having an inlet opening onto one of said transverse surfaces (24) and an outlet opening onto the other of said transverse surfaces (24).

8. Thermoacoustic machine (1) according to any one of claims 1 to 7, wherein the body (22) of the heat exchanger (12) comprises several rows of first channels (31) which are each formed by several respective first channels (31) and several rows of second channels (20) which are each formed by several respective second channels (20), the rows of first channels (31) being arranged alternately with the rows of second channels (20) in a transverse direction (D3).

9. Thermoacoustic machine (1) according to any one of claims 1 to 8, wherein the body (22) of the heat exchanger (12) comprises a first material, preferably a conductive metal and the cover (23) comprises a second material, for example an elastomer, a resin or a plastic.

10. A method of manufacturing a thermoacoustic machine (1) according to any one of claims 1 to 9, comprising a step of fixing the cover (23) to the body (22) of the heat exchanger (12).

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