Polymer heat exchanger
The monolithic polymer heat exchanger addresses the challenge of low mass and high efficiency by integrating fluid conduits within its polymeric body, achieving efficient heat transfer and compact integration in vehicles.
Patent Information
- Application Number
- FR2022013830
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-12-19
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2042-12-19
AI Technical Summary
Existing polymer heat exchangers face challenges in achieving low mass and high heat exchange efficiency, particularly for applications in the automotive field, where they are increasingly integrated into vehicles to reduce mass while maintaining thermal and mechanical conductivity.
A monolithic polymer heat exchanger with a polymeric material body featuring a wall that incorporates fluid circulation conduits within its volume, forming a cavity with a volume significantly larger than the wall, and includes curved or bent portions to enhance heat exchange efficiency.
The design achieves efficient heat exchange with a low mass, allowing for compact integration in vehicles and effective heat transfer between fluids, with the cavity volume being up to hundreds of times greater than the wall volume, ensuring optimal thermal performance.
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Abstract
Description
Title of the invention: Polymer heat exchanger Technical field
[0001] The present invention relates to the field of heat exchangers. Prior art
[0002] Polymer heat exchangers have been known for a long time. Given the low thermal conductivity and excellent corrosion resistance of the polymers they are made of, polymer heat exchangers are generally used for heating or cooling highly corrosive fluids, or for circulating ultrapure fluids for which no metallic contamination is permitted, such as in the semiconductor industry. They can also operate up to an operating temperature of up to 350°C for the most thermally resistant polymers.
[0003] However, although requiring larger heat exchange surfaces than metal heat exchangers, polymer heat exchangers are increasingly being integrated into vehicles in order to reduce their mass, particularly following the availability of new polymer materials with high thermal and mechanical conductivity. Furthermore, these heat exchangers are generally obtained by injection and bonding.
[0004] Polymer heat exchangers can be of the single-flow type, for heating or cooling parts or fluids (immersion exchanger). They are often used in the surface treatment and chemical industries, for example to control the temperature of acid or alkaline baths or high-purity solutions.
[0005] Double-flow polymer heat exchangers are also known for exchanging heat between two streams of material, solid or fluid, circulating in the exchanger. Shell and tube exchangers and plate exchangers are examples of double-flow heat exchangers.
[0006] There is therefore a need for a new heat exchanger having a low mass and good heat exchange efficiency, and in particular suitable for application in the automotive field. Summary of the invention
[0007] The invention at least partially meets this need and proposes a heat exchanger comprising a monolithic body comprising, or even consisting of, a polymeric material, the body comprising a wall having an inner face which delimits a cavity whose volume is greater than the volume of the wall, at least one fluid circulation conduit being arranged in the mass of the wall, opening out of the wall via a fluid inlet and a fluid outlet, and comprising at least one curved and / or bent portion.
[0008] The heat exchanger thus makes it possible to exchange heat efficiently, for example with a liquid or a part contained in the cavity. It also has the advantage of low mass due to the integration of the fluid circulation conduit into the volume of the wall.
[0009] The volume of the cavity may be more than twice, or even more than ten times, or even more than twenty times, or even more than fifty times, or even more than one hundred times greater than the volume of the wall.
[0010] The volume of the wall is delimited by the inner and outer faces of the wall. It therefore includes the volume occupied by the fluid circulation conduit.
[0011] The volume of the cavity can be between 10 cm3 and 10000 cm3.
[0012] The cavity length may be more than twice, or even more than ten times, or even more than twenty times greater than the minimum wall thickness. The "length" of the cavity is the greatest distance separating two opposite parts of the inner face, the distance being measured normally to the inner face of the wall. The "minimum thickness" or "maximum thickness" of the wall is the smallest or greatest distance between the inner face and the outer face of the wall, measured normally to the inner face of the wall.
[0013] The minimum wall thickness may be between 500 μm and 5 mm.
[0014] The maximum wall thickness may be less than 25 mm.
[0015] Preferably the wall has a thickness, at least in a transverse section, of between 500 μm and 20 mm.
[0016] The wall may be solid. Alternatively, it may include one or more openings which pass right through its thickness. Where appropriate, the cavity is delimited by the envelope surface of the inner face of the wall.
[0017] The wall may comprise several partitions, for example one or more side partitions which extend from a bottom partition. For example, the wall has a generally parallelepiped shape.
[0018] Alternatively, it may have a general semi-cylindrical shape.
[0019] Preferably, the wall defines an access opening to the cavity, for example through which a liquid can be introduced into the cavity.
[0020] The body may be shaped to be mounted on a support, for example of a motor vehicle. For example, it comprises at least one through hole in which a screw can be engaged to fix it on the support.
[0021] Alternatively, the wall may include a fixing means, for example a screw thread, a groove or a snap-in relief, for mounting the body on a support or for fixing a cover to close the access opening to the cavity. The fixing means can be carried by the external face of the wall.
[0022] The polymeric material may be chosen from polylactic acid, acrylonitrile butadiene styrene, polyethylene terephthalate, polyamide, thermoplastic polyurethane, polycarbonate, polypropylene, polyvinylidene fluoride, polyethylene chlorotrifluoroethylene, polytetrafluoroethylene, perfluoroalkoxy, fluorinated ethylene propylene, a thermoplastic elastomer, a polyethylene glycol-based copolymer, a polypropylene glycol-based copolymer and mixtures thereof. Preferably, the polymeric material is chosen from polylactic acid, acrylonitrile butadiene styrene, polyethylene terephthalate, polyamide, for example designated PA6, PAU or PA12, thermoplastic polyurethane, polycarbonate and mixtures thereof. For example, the polymeric material may be a mixture of polycarbonate and acrylonitrile butadiene styrene.
[0023] The wall may be made of the polymeric material.
[0024] Alternatively, the wall may be made of a composite material formed from a matrix consisting of the polymeric material and filler particles dispersed in the matrix. The filler particles are made of a filler material, preferably having a thermal conductivity measured at 25°C of between 6 Wm *.K1 and 6000 Wm *.K *. The filler material may be chosen from carbon, copper, silver, gold, aluminum, nickel, boron nitride, aluminum nitride, beryllium oxide, aluminum oxide and mixtures thereof. The carbon filler particles may be in the form of graphite particles, carbon black, carbon nanotubes, diamond and carbon fibers.
[0025] Preferably, the wall has at least in a transverse section, a thickness which is less than or equal to 3 times, preferably less than or equal to 2 times, the diameter of the fluid circulation conduit. In this way, efficient heat transfer is ensured through the wall between the heat transfer fluid circulating in the fluid circulation conduit and a material contained in the cavity.
[0026] The fluid circulation conduit may have a diameter of between 1 mm and 10 mm.
[0027] The fluid circulation channel preferably has a tubular shape, for example with a rectangular or circular contour section.
[0028] The diameter of the fluid circulation conduit may vary along the fluid circulation conduit.
[0029] It can be constant over more than 50%, or even over more than 80%, or even over more than 90% of the length of the axis of the fluid circulation conduit.
[0030] Preferably, the fluid circulation conduit extends at least in part, preferably over more than 50%, or even over more than 90% of its length, in a plane median extension of the wall.
[0031] In particular, the fluid circulation conduit may have a smaller diameter in at least one transverse section where the thickness of the wall is small.
[0032] The fluid circulation conduit may comprise one or more meandering portions, in particular at least one portion in the form of a serpentine, or at least one portion in the form of a spiral.
[0033] The fluid circulation conduit may comprise at least one layer of portions parallel to each other which extend in the same layer plane, preferably parallel to the extension plane of the wall. Preferably, it comprises a single layer, in order to limit the thickness of the wall while ensuring optimal heat exchange.
[0034] The fluid circulation circuit may have at least one portion that extends right through its length between two opposite edges of the wall. In particular, the edges may connect the inner face to the outer face of the wall.
[0035] Preferably, the fluid inlet and the fluid outlet open onto the outer face of the wall. In this way, the supply and extraction of the heat transfer fluid can be carried out without passing through the cavity.
[0036] Preferably, the heat exchanger comprises two fluid circulation conduits.
[0037] The two fluid circulation conduits are first and second fluid circulation conduits for transferring heat between first and second fluids respectively through the mass of the wall. The heat exchanger is then of the “double-flow” type. Advantageously, the heat exchanger allows heat transfer between the fluids while defining a housing in the cavity. It thus makes it possible to make a device, for example an element of an engine, in which it is integrated, more compact.
[0038] Preferably, the first and second fluid circulation conduits are separated over more than 50%, preferably more than 80%, preferably more than 95% of their respective lengths, by a distance of between 50 μm and 10 mm, in particular between 0.5 mm and 10 mm, in particular between 1 mm and 10 mm, in particular less than 5 mm. The distance separating two fluid circulation conduits is, in a transverse section of the wall, the smallest distance between the inner faces of said conduits.
[0039] In particular, the first and second fluid circulation circuits may have meandering portions which extend along parallel axes. The axes may be curvilinear or rectilinear or have rectilinear and curvilinear portions.
[0040] The circulation conduit for the first fluid and the circulation conduit for the second fluid may have identical shapes.
[0041] The heat exchanger may be a heat exchanger of a motor vehicle. Preferably, the body is a component of an engine of an automobile. The engine component is preferably an oil pan.
[0042] Alternatively, the body may be a container for holding a liquid and / or a powder in the cavity.
[0043] The heat exchanger is preferably a water / oil heat exchanger. The first fluid is preferably an engine lubricating oil. An "A / B" exchanger is an exchanger configured to exchange heat between fluid A and fluid B.
[0044] Preferably, the water / oil exchanger is housed in the lower part of the engine, in order to be as close as possible to the source of lubricating oil contained in the oil sump.
[0045] The heat exchanger may include a pump in fluid communication with the body for introducing and extracting fluid through the fluid inlet and the fluid outlet respectively.
[0046] The invention also relates to a method of manufacturing a heat exchanger according to the invention, the method comprising the production of the body by an additive manufacturing technique.
[0047] An “additive manufacturing” technique, as is well known to those skilled in the art, involves the deposition of a material in successive passes to form a stack of layers until a monolithic part is obtained.
[0048] Preferably, the additive manufacturing technique is a powder bed additive manufacturing technique, for example chosen from additive manufacturing by selective laser sintering, also called “SLS” additive manufacturing, and additive manufacturing by multi-jet fusion, also called “MJF” additive manufacturing, notably implemented by the company HP.
[0049] Preferably, the monolithic body is obtained by the method according to the invention. Brief description of the drawings
[0050] The invention may be better understood by reading the detailed description which follows and the attached drawing, in which
[0051] [Fig. 1] is a perspective representation of an example of an exchanger body of heat according to the invention,
[0052] [Fig.2] is a view of the body illustrated in [Fig.l], only the inner face and the faces fluid distribution conduits being represented,
[0053] [Fig.3] is a variant of the body illustrated in [Fig.2],
[0054] [Fig.4] is a partial view of a transverse section along the plane (P) of the body of the [Fig.3],
[0055] [Fig.5] is a representation of another example of a body of an exchanger according to the invention, and
[0056] [Fig.6] is a view of the body of [Fig.5], only the inner face and the faces of the fluid distribution conduits being shown. Detailed description
[0057] Figures 1 and 2 illustrate an example of a heat exchanger 1 according to the invention.
[0058] The heat exchanger 1 comprises a body 2 including a wall 3 which extends along an axis X. The wall has a “U” shape, when seen in a cross-section to the axis X.
[0059] The wall 3 has an outer face 5 and an inner face 6. The inner face 6 delimits a cavity 7, which opens out of the body through an opening 8. A first fluid circulation conduit 9 and a second fluid circulation circuit 10 are provided in the mass of the wall 3.
[0060] The wall 3 comprises a bottom partition 11 and two side partitions 12, 13 which each extend perpendicularly from the bottom partition 11. The side partitions 12, 13 are opposite each other and separated by the length L of the cavity. The length L is for example between 1 cm and 50 cm.
[0061] The wall has a thickness e of between 500 μm and 5 mm, which varies along the wall. In particular, the side partitions 12, 13 each have a bead 14 at their end opposite the bottom wall, of maximum thickness, and a portion of lesser and constant thickness which connects the bead to the bottom wall.
[0062] First and second fluids may circulate in the first 9 and second 10 fluid circulation circuits respectively.
[0063] The first fluid circulation circuit 9 extends between a first fluid inlet 15 and a first fluid outlet 16. The second fluid circulation circuit 10 extends between a second fluid inlet 17 and a second fluid outlet 18.
[0064] The first and second fluid inlets and the first and second fluid outlets open onto the outer face 5 of the wall. More particularly, the first and second fluid inlets and outlets open onto the outer face of one of the side partitions 12, 13. In a variant shown in [Fig. 3], the first and second fluid inlets open onto the outer face of one of the side partitions, and the first and second fluid outlets open onto the outer face of the opposite side partition.
[0065] The first 9 and second 10 fluid circulation conduits each extend in the mass of the wall along axes Y, Y' respectively substantially parallel over more than 50% of their length.
[0066] Each of the first 9 and second 10 fluid circulation conduits has rectilinear portions 19, 20. These rectilinear portions are each included in planes perpendicular to the axis X of the wall and parallel to each other.
[0067] In a plane perpendicular to the X axis, the first 9, respectively the second 10, fluid circulation conduit has a rectilinear portion 21, 22 in the bottom partition connected at each of its ends by a curved and bent portion 23, 24 to a rectilinear portion 19, 20 formed in each of the opposite lateral partitions. Furthermore, the rectilinear portions 19, 20, 21, 22 extend right through each of the bottom partition 11 and the respective lateral partitions 12, 13.
[0068] Furthermore, the first 9, respectively the second 10 fluid circulation conduit comprises another curved and bent portion 25, 26 included in a plane parallel to the axis X, in order to ensure a fluid connection between the adjacent parts of the first 9, respectively of the second 10 fluid circulation conduit which are arranged in planes parallel to the axis X.
[0069] Thus, the first 9 and second 10 fluid circulation conduits follow a meandering path in the form of a serpentine in the mass of the wall.
[0070] [Fig. 3] shows an alternative embodiment of the body illustrated in Figures 1 and 2, in which the axes Y, Y' of the fluid circulation conduits are shown in dotted lines.
[0071] The body illustrated in [Fig. 3] differs from the body illustrated in Figures 1 and 2 in that the first 9 and second 10 fluid circulation conduits have, in each of the bottom and side partitions, rectilinear portions parallel to the axis X connected by a right-angled portion 21, 22 to rectilinear portions contained in a plane transverse to the axis X. It further differs by first fluid outlets 16 and second fluid outlets 18 opening onto a face of the side partition 13 opposite the side partition 12 on which the first fluid inlets 15 and second fluid inlets 17 are arranged.
[0072] [Fig.4] illustrates a transverse section of the side partition 12.
[0073] Preferably, the distance d between the inner face 6 of the wall 3 and the inner face 27 of the or one of the fluid circulation conduits 9, 10, is preferably between 500 μm and 2 cm, in order to obtain a good compromise between a low mass of the body and an optimal heat exchange, while ensuring a minimum mechanical resistance of the wall.
[0074] Furthermore, in the variant where the body comprises first and second fluid circulation conduits, the distance between the first and second conduits is preferably between 50 μm and 10 mm, in particular less than or equal to 5 mm, to ensure good heat exchange between the first and second fluids.
[0075] Finally, Figures 5 and 6 illustrate a third variant of body 2 which differs from that illustrated in [Fig.2] in that the wall has a substantially hemispherical shape, when viewed along the X axis.
[0076] The invention is not limited to the embodiments and examples presented for illustrative and non-limiting purposes.
Claims
Claims
1. Heat exchanger (1) comprising a monolithic body (2) comprising, or even consisting of, a polymeric material, the body (2) comprising a wall (3) having an inner face (6) which delimits a cavity (7) whose volume is greater than the volume of the wall, at least a first (9) and a second (10) fluid circulation conduits being arranged in the mass of the wall for the transfer of heat between first and second fluids respectively through the mass of the wall (3), the first and second fluid circulation conduits each opening out of the wall via a fluid inlet (15, 17) and a fluid outlet (16, 18), and comprising at least one curved and / or bent portion (23, 24, 25, 26).
2. Heat exchanger according to claim 1, the minimum wall thickness being between 500 pm and 5 mm and / or the maximum wall thickness being less than 25 mm.
3. Heat exchanger according to any one of claims 1 and 2, the wall having at least in one transverse section, a thickness which is less than or equal to 3 times, preferably less than or equal to 2 times, the diameter of each of the first and second fluid circulation conduits.
4. Heat exchanger according to any one of the preceding claims, each of the first and second fluid circulation conduits having a diameter (¢) of between 1 mm and 10 mm.
5. Heat exchanger according to any one of the preceding claims, each of the first and second fluid circulation conduits comprising one or more meandering portions, in particular at least one portion in the form of a serpentine, or at least one portion in the form of a spiral.
6. Heat exchanger according to any one of the preceding claims, each of the first and second fluid circulation conduits comprising at least one layer of portions parallel to each other which extend in the same layer plane, preferably parallel to the extension plane of the wall.
7. Heat exchanger according to any one of the preceding claims, the fluid inlet (15,17) and the fluid outlet (16,18) open onto the outer face (5) of the wall (3).
8. Exchanger according to any one of the preceding claims, the first and second fluid circulation conduits being separated over more than 50%, preferably more than 80%, preferably more than 95% of their respective lengths, by a distance (d') of between 50 pm and 10 mm, preferably between 0.5 mm and 10 mm, in particular between 1 mm and 10 mm.
9. Heat exchanger according to any one of the preceding claims, the body being obtained by an additive manufacturing technique.
10. A heat exchanger according to any preceding claim, the body (2) being an element of an automobile engine or being a container for containing a liquid and / or a powder in the cavity (7).