SE1950371A1 - Heat transfer device - Google Patents

Abstract

A heat transfer device (100) comprising at least one body (300, 301, 302, 303, 304, 305) and thermally conducting fibers (2) extending through the at least one body (300, 301 , 302, 303, 304, 305) and extending out from the at least one body (300, 301 , 302, 303, 304, 305) from at least one surface (300a, 300b, 301a, 301b, 302a, 302b, 303a, 303b, 304a, 304b, 305a, 305b) of the at least one body (300, 301, 302, 303, 304, 305), wherein the thermally conducting fibers (2) have a length of at least 1 mm, wherein the thermally conducting fibers have a conductivity of at least 50 W/mK, wherein the thermally conducting fibers have a diameter of at least 4 micrometers.

Description

HEAT TRANSFER DEVICE Technical field 1. 1. id="p-1" id="p-1"

[0001] The present invention relates generally to a heat transfer device, a heattransfer system and a methods of preparing the same.

Background art 2. 2. id="p-2" id="p-2"

[0002] lt is known to use heat conducting carbon fibers in heat sinks. Such heatsinks typically employs a single body formed of heat conductive metal providing ahigh thermal conductivity. 3. 3. id="p-3" id="p-3"

[0003] A drawback of known solutions is that the metal content of the wallincreases cost of production, and the current manufacturing methods involvescasting or molding around the fibers which is an inefficient method that increasesthe thickness of the wall during production and further limits the available length ofthe fibers and/or requires further manufacturing steps to expose carbon fiber ends.Another drawback of is that the short length of the fibers reduces the efficiencyand thus the transferred heat power.

Summary of invention 4. 4. id="p-4" id="p-4"

[0004] An object of the present invention is to alleviate some of thedisadvantages of the prior art and to provide a heat transfer device, and a heattransfer system which increases heat transfer efficiency. A further object of thepresent invention is to provide a heat transfer device and system which enables ahigh degree of freedom in forming the heat transfer device and system dependingon the indented use. A further object of the present invention is to providemethods of preparing the heat transfer device or system. A further object of thepresent invention is to provide methods of preparing the heat transfer device orsystem that is more efficient than current methods. . . id="p-5" id="p-5"

[0005] According to one embodiment of the invention, a heat transfer device is provided comprising at least one body and thermally conducting fibers extending through the at least one body and extending out from the at least one body from atleast one surface of the at least one body, wherein the thermally conducting fibershave a length of at least 1 mm, wherein the thermally conducting fibers have aconductivity of at least 50 W/mK, wherein the thermally conducting fibers have adiameter of at least 4 micrometers. 6. 6. id="p-6" id="p-6"

[0006] According to one embodiment, the at least one body comprises at least30 vvt% non-metallic material(s), preferably at least 70 wt % non-metallicmaterial(s), more preferably at least 90 wt% non-metallic material(s), mostpreferably 100 wt% non-metallic material(s). 7. 7. id="p-7" id="p-7"

[0007] According to one embodiment, the thermally conducting fibers have aconductivity of 50-300 W/mK, preferably 301-799, more preferably 800-1000W/mK. 8. 8. id="p-8" id="p-8"

[0008] According to one embodiment, the thermally conducting fibers extendfrom at least two surfaces of the at least one body. 9. 9. id="p-9" id="p-9"

[0009] According to one embodiment, the thermally conducting fibers comprisesfree ends. . . id="p-10" id="p-10"

[0010] According to one embodiment, the thermally conducting fibers preferablyhave a diameter of 4-15 micrometers, more preferably 7-10 micrometers. 11. 11. id="p-11" id="p-11"

[0011] According to one embodiment, the at least one body comprises resinand/or thermoplastic materials. 12. 12. id="p-12" id="p-12"

[0012] According to one embodiment, the thermally conducting fibers are carbonfibers. 13. 13. id="p-13" id="p-13"

[0013] According to one embodiment, the at least two surfaces of the at leastone body are opposing surfaces. 14. 14. id="p-14" id="p-14"

[0014] According to one embodiment, the heat transfer device comprises aplurality of bodies, wherein the thermally conducting fibers extend through theplurality of bodies. . . id="p-15" id="p-15"

[0015] According to one embodiment, the thermally conducting fibers extendingout from each of the plurality of bodies from a top and bottom surface respectively. 16. 16. id="p-16" id="p-16"

[0016] According to one embodiment, the plurality of bodies are positioned substantially equidistant from each other. 17. 17. id="p-17" id="p-17"

[0017] According to one embodiment, the heat transfer device is in the form of a sheet. 18. 18. id="p-18" id="p-18"

[0018] According to one embodiment a heat transfer system is provided,comprising a plurality of heat transfer devices according to any embodiment[0005]-[00017] stacked to each other wherein the at least one body or plurality ofbodies of adjacent heat transfer devices are bonded to each other. 19. 19. id="p-19" id="p-19"

[0019] According to one embodiment, at least a subset of consecutive bodies ofthe plurality of bodies of the two outer heat transfer devices are interconnected by a sealing element extending along a lengthwise direction of the bodies. . . id="p-20" id="p-20"

[0020] According to one embodiment, the heat transfer system is a heat exchanger. 21. 21. id="p-21" id="p-21"

[0021] Use of the heat transfer device or heat transfer system according to anyembodiment [0005]-[0020], in electronic systems, mechanical systems, computerimplemented systems, chemical systems and/or vehicle systems (including space vehicles). 22. 22. id="p-22" id="p-22"

[0022] According to one embodiment a method of preparing a heat transfer device is provided, comprising the steps of: a. Positioning of thermally conducting fibers directed in mainly onedirection in form of a sheet, wherein the thermally conducting fibers are preferably positioned substantially in parallel to each other, b. Positioning of at least one strip of body material in substantiallyperpendicular direction to said thermally conducting fibers on at least one sidesaid sheet, wherein said body material comprises material or materials which result in said body of the heat transfer device, c. Positioning of said sheet and said at least one strip of body material in a press device, d. Pressing said sheet and said at least one strip against each other by the aid of the press device, e. Administering heat to said sheet and said at least one strip before orinside the press device, wherein the heat turns said strip into a substantiallyviscous material which is forced into said sheet and thereby creating a body forming a seal between two sides of said sheet, andf. Pulling out the resulting heat transfer device out from the press device,[0023] According to one embodiment, the method further comprises:g. And wherein steps a-f are optionally iterated at least once. 24. 24. id="p-24" id="p-24"

[0024] According to one embodiment, a plurality of strips of body material ispositioned on said sheet, and wherein the strips are positioned preferably substantially equidistant from each other. . . id="p-25" id="p-25"

[0025] According to one embodiment, the thermally conducting fibers are being pulled from a number of large rolls with bundled fibers. 26. 26. id="p-26" id="p-26"

[0026] According to one embodiment, a new part of the sheet having bodymaterial positioned on the sheet is positioned into the press device at the sametime as the resulting heat transfer device is pulled out from the press device. 27. 27. id="p-27" id="p-27"

[0027] According to one embodiment a heat transfer device is provided, prepared by a method according to any embodiment [0022]-[0032]. 28. 28. id="p-28" id="p-28"

[0028] According to one embodiment, a method of preparing a heat transfersystem comprising a plurality of heat transfer devices according to anyembodiment [0005]-[0017], [0022]-[0032] is provided, comprising the steps: -Stacking a plurality of heat transfer devices to each other,-Bonding bodies of adjacent heat transfer devices to each other.[0029] According to one embodiment, the, method further comprising: -interconnecting at least a subset of consecutive bodies of the two outer heat transfer devices in the stack of heat transfer devices by a sealing element.

Brief description of drawinqs . . id="p-30" id="p-30"

[0030] The invention is now described, by way of example, with reference to the accompanying drawings, in which: 31. 31. id="p-31" id="p-31"

[0031] Fig. 1 shows a side view of a heat transfer device according to one embodiment of the invention. 32. 32. id="p-32" id="p-32"

[0032] Fig. 2 shows a side view of a heat transfer device according to one embodiment of the invention. 33. 33. id="p-33" id="p-33"

[0033] Fig. 3 shows a side view of a heat transfer device according to one embodiment of the invention. 34. 34. id="p-34" id="p-34"

[0034] Fig. 4 shows a side view of a heat transfer device according to one embodiment of the invention. . . id="p-35" id="p-35"

[0035] Fig. 5 shows a device for carrying out a method of preparing a heattransfer device according to the invention. 36. 36. id="p-36" id="p-36"

[0036] Fig. 6a-6b shows a device for carrying out a method of preparing a heattransfer device along section A-A of Fig. 5. 37. 37. id="p-37" id="p-37"

[0037] Fig. 7 shows a method of preparing a heat transfer device according to one embodiment of the invention. 38. 38. id="p-38" id="p-38"

[0038] Fig. 8a-8c shows a method of preparing a heat transfer system, and a heat transfer system according to one embodiment of the invention. 39. 39. id="p-39" id="p-39"

[0039] Fig. 9a-9b shows a method of preparing a heat transfer system and aheat transfer system according to one embodiment of the invention. 40. 40. id="p-40" id="p-40"

[0040] Fig. 10a-10b shows a perspective view of a heat transfer system according to one embodiment of the invention. 41. 41. id="p-41" id="p-41"

[0041] Fig. 11a-11d shows a f|uid duct comprising a heat transfer system according to one embodiment of the invention.

Description of embodiments 42. 42. id="p-42" id="p-42"

[0042] ln the following, a detailed description of the invention will be given. lnthe drawing figures, like reference numerals designate identical or correspondingelements throughout the several figures. lt will be appreciated that these figuresare for illustration only and are not in any way restricting the scope of the invenfion. 43. 43. id="p-43" id="p-43"

[0043] ln general, a heat transfer device such as a heat exchanger or heat sinkcomprises a cold side and warm side and a wall to separate the cold side from thewarm side. The heat transfer device is configured to transfer heat from the warmside to the cold side. On either or both sides of the wall, there may be a f|uidmedium. ln some cases, heat is transferred from a non fluid medium such as e.g.mechanical devices. A heat transfer coefficient (HTC) between the f|uid and thewall depends on f|uid velocity, density etc. Walls should be made thin yet providesufficient structural integrity. The walls should have a high thermal conductivity. 44. 44. id="p-44" id="p-44"

[0044] Fig. 1 shows a side view of a heat transfer device 100, comprising onebody 300 and thermally conducting fibers 2 extending through the at least onebody 300 and extending out from the at least one body 300 from one surface 300aof the at least one body by the portion 2a. According to one embodiment the thermally conducting fibers 2 and the at least one body forms a wall. According toone embodiment, the body 300 comprises a at least one strip 30a, 30b of bodymaterial as can be further seen in Fig. 5. According to one embodiment, the strips30a, 30b are pre-preg strips. According to one embodiment, the body 300comprises a first 30a and second 30b strip of body material. According to oneembodiment, the strips 30a, 30b of body material comprises material configuredto, and with a viscosity that it is sufficient to, impregnate the dry thermallyconducting fibers and then become sufficiently stiff to make handling of the heattransfer device 100, or a basic building block thereof, possible. According to oneembodiment, suitable material for the body 300 comprises thermosetting resinssuch as e.g. epoxy, polyester, vinylester, thermoplastic materials. According toone embodiment, the strips 30a, 30b are resin rich strips. According to oneembodiment, the body 300 provides a fluid tight seal in a heat transfer devicebetween surfaces 300a, 300b of the body 300. According to one embodiment thestrips 30a, 30b may further comprise fibers, particles, metal or other filler materialfor improving the manufacturing material. According to one embodiment the strips30a, 30b may consist of such material. According to one embodiment, the at leastone body 300 comprises at least 30 vvt% non-metallic material(s), preferably atleast 70 wt % non-metallic material(s), more preferably at least 90 wt% non-metallic material(s), most preferably 100 wt% non-metallic material(s). The benefitof using non-metallic material or materials in the body 300 above a certain degreeis e.g. a lower cost of production. Reducing the cost of production is beneficial inthat it enables large volume production. Using the below described thermallyconducting fibers 2 with the parameters described below comprising, their thermalconductivity, the relatively large length of the fibers, their small diameter enablesthe use of a thin, yet to a high degree, metal free, i.e. non-metal body 300.According to one embodiment, side 4 forms a cold side 4, and side 5 forms a warm side 5. 45. 45. id="p-45" id="p-45"

[0045] According to one embodiment, the thermally conducting fibers 2 have alength of at least 1 mm. According to one embodiment, the length is between 1mmand 50 mm. According to one embodiment, the length is between 1mm and 500 mm. According to one embodiment, the length of the fibers can be any length based on the intended use. According to one embodiment the ratio of the length ofthe fibers extending out from at least one body from at least one surface and thelength of the fibers extending through the at least one body is at least 1:1.According to one embodiment, the thermally conducting fibers 2 have aconductivity of at least 50 W/mK. According to one embodiment, the thermallyconducting fibers have a conductivity of at least 301-799, more preferably 800-1000 W/mK. 46. 46. id="p-46" id="p-46"

[0046] According to one embodiment, the thermally conducting fibers have asmall diameter for creating a large surface area. According to one embodiment,the thermally conducting fibers 2 have a diameter of at least 4 micrometers.According to one embodiment, the thermally conducting fibers 2 preferably have a diameter of 4-15 micrometers, more preferably 7-10 micrometers. 47. 47. id="p-47" id="p-47"

[0047] According to one embodiment, the heat transfer device 100 is in the formof a sheet 20. According to one embodiment, the sheet form comprises asubstantially flat form. According to one embodiment, the sheet form comprises asubstantially flat form as seen in one plane. According to one embodiment, thesheet form comprises a substantially flat form with a relatively larger extension intwo surface directions than in the height direction, herein referred to as the sheetsurface 20a. According to one embodiment, the sheet 20 may take any suitableform in the plane, such as e.g. rectangular, circular etc. depending on the intended USS. 48. 48. id="p-48" id="p-48"

[0048] By using longer, as well as a smaller diameter of the thermallyconducting fibers 2, the total surface area of the wall may substantially beincreased. A large surface area increases the efficiency of transferring heat of theheat transfer system device. Since the thermally conducting fibers 2 extendthrough the body and forms the wall, and not by being attached to the body a goodthermal conductivity provided since there are no contact problems between thefibers and the body in the wall. 49. 49. id="p-49" id="p-49"

[0049] According to one embodiment, the thermally conducting fibers are carbonfibers. According to other embodiments the thermally conducting fibers are at least one of the following: graphite, copper, aluminium, silver, gold, silicon, boron, orany other thermally conducting material in the form of fibers. 50. 50. id="p-50" id="p-50"

[0050] According to one embodiment, the number of the thermally conductingfibers per square centimeter, such as e.g. seen in the plane as shown in section B-B in Fig. 6b, is in the range of 1-104-1-106fibers per square centimeter. Accordingto one embodiment, the thermally conducting fibers 2 are a plurality of thermallyconducting fibers 2. 51. 51. id="p-51" id="p-51"

[0051] Fig. 2 shows a side view of a heat transfer device 100, wherein thethermally conducting fibers 2 extending out from the at least one body 300 fromtwo surfaces 300a, 300b of the at least one body 300 e.g. by the portions 2a, 2brespectively. According to this embodiment, the different surfaces 300a, 300b,such as the at least two surfaces 300a, 300b, of the at least one body 300 isopposing surfaces 300a, 300b. According to the embodiment, the thermallyconducting fibers 2 have free ends 2c. As such the fibers are configured for beingfree, i.e. have free ends, in the sense that these ends are not connected to anystructure to or from which heat is transferred. According to one embodiment, side4 forms a cold side 4, and side 5 forms a warm side 5. 52. 52. id="p-52" id="p-52"

[0052] Fig. 3 shows a side view of a heat transfer device 100 comprising twobodies 300, 301, wherein the thermally conducting fibers 2 extend through the atleast two bodies 300, 301. According to one embodiment, side 4 forms a cold side4, and side 5 forms a warm side 5. 53. 53. id="p-53" id="p-53"

[0053] Fig. 4 shows a side view of a heat transfer device 100 comprising sixbodies 300, 301, 302, 303, 304, 305, similar to the body 300 as described above,wherein the thermally conducting fibers 2 extend through the six bodies 300, 301,302, 303, 304, 305. According to one embodiment, the heat transfer device 100comprising a plurality of bodies 300, 301 N, which may be any suitable numberN based on the intended use or application. According to one embodiment, theheat transfer device 100 comprises an even number of plurality of bodies 300,301, 302, 303, 304, 305,..., 2N, wherein the thermally conducting fibers 2 extendthrough the even number of plurality of bodies 300, 301, 302, 303, 304, 305, iO 2N. According to one embodiment, the thermally conducting fibers 2 extending outfrom each of the plurality of bodies 300, 301, 302, 303, 304, 305 from a top andbottom surface 300a, 300b, 301a, 301b, 302a, 302b, 303a, 303b, 304a, 304b,305a, 305b respectively. 54. 54. id="p-54" id="p-54"

[0054] According to one embodiment, the bodies 300, 301, 302, 303, 304, 305are positioned substantially equidistant from each other. According to oneembodiment, any two consecutive bodies 300, 301 are arranged at a similardistance from each other as any other two consecutive bodies 301, 302.According to one embodiment the any two consecutive bodies 300, 301 arearranged at a different distance from each other as any other two consecutivebodies 301, 302. 55. 55. id="p-55" id="p-55"

[0055] Fig. 5 shows a device 1000 for carrying out a method of preparing a heattransfer device 100 according to one embodiment of the invention, comprising apress device 500. According to one embodiment, the press device 500 comprisesa heating device 550 further comprising at least one heating device element 551,552 for heating at least one of the surfaces of the press device 500. The pressdevice 500 is configured to generate a pressure F to the fibers 2 and strips 30a,30b of body material and to force the viscous body material into the dry fibers 2.The pressure F can be varied and selected depending on materials used for fibers2 and/or body 300/strips 30a, 30b, thicknesses, temperatures, and other processparameters. The press device 500 may be any pressure generating device, forinstance an hydraulic press, comprising a sufficiently sized flat contact surfaces510, 520 to fit the desired width of the sheet of fibers 2, and its dimensions andparameters may be selected to optimize the production process and volume.According to one embodiment, the contact surface 510 is movable in relation tothe contact surface 520. After passing the press device 500, the heat transferdevice 100 formed may be cut in any desired length. 56. 56. id="p-56" id="p-56"

[0056] Fig. 6a shows a device 1000 for carrying out a method of preparing aheat transfer device 100, as well as a sheet 20 and said at least one strip 30a, 30bbeing pressed against each other by the aid of the press device 500, along section ll A-A of Fig. 5. Fig. 6b shows a heat transfer device 100, prepared by the device1000 along section B-B of Fig. 5. 57. 57. id="p-57" id="p-57"

[0057] Fig. 7 shows a method of preparing a heat transfer device 100comprising the steps of: a. Positioning of thermally conducting fibers 2 directed in mainly onedirection in form of a sheet 20, wherein the thermally conducting fibers 2 are preferably positioned substantially in parallel to each other, b. Positioning of at least one strip 30a, 30b, 31a, 31 b of body materialin substantially perpendicular direction to said thermally conducting fibers 2 on atleast one side said sheet 20, wherein said body material comprises material ormaterials which result in said body 300 of the heat transfer device 100, c. Positioning of said sheet and said at least one strip 30a, 30b ofbody material in a press device 500, d. Pressing said sheet 20 and said at least one strip 30a, 30b againsteach other by the aid of the press device 500, e. Administering heat to said sheet 20 and said at least one strip 30a,30b before or inside the press device 500, wherein the heat turns said strip 30a,30b into a substantially viscous material which is forced into said sheet 20 andthereby creating a body 300 forming a seal between two sides 4, 5 of said sheet20,and f. Pulling out the resulting heat transfer device 100 out from the pressdevice 500, 58. 58. id="p-58" id="p-58"

[0058] According to one embodiment, the method further comprises the step:g. And wherein steps a-f are optionally iterated at least once. 59. 59. id="p-59" id="p-59"

[0059] According to one embodiment, the heat transfer device is cut in a desired length, with a desired number of bodies. According to one embodiment the cut is 12 carried out across the fibers 2. According to one embodiment, the cut is carried outalong the bodies. 60. 60. id="p-60" id="p-60"

[0060] According to one embodiment of the method of preparing the heattransfer device, at least a plurality of strips of body material is positioned on saidsheet 20, and wherein the strips 30a, 30b and 31a, 31 b of body material arepositioned at a distance from each other on the sheet 20. According to oneembodiment, the strips of body material comprises upper strips 30a, 31 apositioned on one (upper) side of the fibers 2 and lower strips 31a, 31 b positionedat a corresponding position, respectively, on the other (lower) side of the fibers 2. 61. 61. id="p-61" id="p-61"

[0061] According to one embodiment, the strips 30a, 30b and 31a, 31 b of bodymaterial are positioned substantially equidistant from each other. By positioningthe strips either substantially equidistant from each other, or, each strip beingplaced at a predefined distance from another strip enables the manufacturing ofsimilar heat transfer devices 100. Such heat transfer devices may be stackedtogether and used for forming a heat transfer system as shall be further describedin Fig. 8a-8c, 9a-9b. 62. 62. id="p-62" id="p-62"

[0062] According to one embodiment of the method of preparing the heattransfer device 100, the thermally conducting fibers 2 are being pulled from anumber of large rolls 200 with bundled fibers 2. 63. 63. id="p-63" id="p-63"

[0063] According to one embodiment of the method of preparing the heattransfer device 100, a new part of the sheet 20 having body material positioned onthe sheet 200 is positioned into the press device 500 at the same time as theresulting heat transfer device 100 is pulled out from the press device 500. 64. 64. id="p-64" id="p-64"

[0064] According to one embodiment, the amount of fibers 2 are adjusted foroptimizing the flow of fluid during use vs the pressure loss, depending on theintended use. 65. 65. id="p-65" id="p-65"

[0065] According to one embodiment, the above described method of preparingthe heat transfer device 100 enables the possibility to manufacture continuously inan automated and highly efficient process. 13 66. 66. id="p-66" id="p-66"

[0066] Fig. 8a shows a method of stacking a plurality of heat transfer devices100, according to Fig. 3 into a heat transfer system 1 as seen in Fig. 8b byapplying a pressure F on the sheet surface 20a. According to one embodimentheat is provided in the process of stacking the heat transfer devices 100. Thus, theheat transfer devices 100, in Fig. 8a are shown to extend in a depth direction bythe dotted lines. By the dotted lines, the length or depth of the sheets 20 or theheat transfer devices 100, may be selected to any length depending the intendeduse. Thus, the heat transfer system 1 of Fig. 8b comprises a plurality of heattransfer devices 100 stacked to each other wherein the bodies 300, 301, 302, 303,304, 305 of adjacent heat transfer devices 100, respectively, are bonded to eachother by applying a pressure F and, optionally, heat, and optionally an adhesive.According to one embodiment, this process is carried out in a press device 500 asdescribed above. According to one embodiment, the heat transfer system 1comprises two outer heat transfer devices 100, in the stack of heat transferdevices 100, wherein succeeding, or consecutive bodies of each of the outer heattransfer devices 100, 150 are interconnected by a sealing element 400 extendingalong a lengthwise direction of the bodies 300; 301. This forms a channel 5 sealedfrom the outside by the body material and the sealing element 400. The heattransfer system 1 formed in Fig. 8b comprises a side 4, such as e.g. a cold side 4, and a side 5, such as a warm side 5 being formed by the channel 5. 67. 67. id="p-67" id="p-67"

[0067] Fig 8c shows an alternative embodiment, as compared to that of Fig. 8b,wherein at least some fibers, or part of fibers, have been removed on the warmside 5 to reduce pressure loss, and/or increase fluid velocity and/or increase fluidflow, which e.g. improves heat transfer coefficient between the fluid and bodymaterial. According to one embodiment at least some fibers, or part of fibers, mayalternatively be removed on the cold side 4. According to one embodiment,channels 50 are formed in the warm side 5 extending length wise along the lengthof the heat transfer system 1. According to one embodiment, such heat transfersystem 1 as described in Fig. 8b, 8c may be used for a gas-liquid heat transfersystem, wherein cold gas flows on the cold side 4, and hot liquid flows on thewarm side 5. The embodiment of Fig. 8b may be used for an intercooler, e.g. in a 14 gas-gas heat transfer system 1. The embodiment of Fig. 8c may be used forradiators. Such heat transfer system 1 may e.g. be used for radiators. 68. 68. id="p-68" id="p-68"

[0068] Fig. 9a, shows a method of stacking a plurality of heat transfer devices100 according to Fig. 4 into a heat transfer system 1 as seen in Fig. 9b by applyinga pressure F on the sheet surface 20a. Thus, compared to the method describedherein is similar to the method described in Fig. 8a, however the heat transferdevices 100 comprise a plurality of bodies such as e.g. six bodies 300, 301, 302,303, 304, 305. According to one embodiment, at least a subset of consecutive orsucceeding bodies of the plurality of bodies 300, 301, 302, 303, 304, 305 of thetwo outer heat transfer devices 100 are interconnected by a sealing element 400extending along a lengthwise direction of the bodies 300; 301302, 303, 304, 305.According to one embodiment, at least a subset of the bodies of the two outer heattransfer devices 100, form pair of bodies 300, 301; 302, 303; 304, 305; whereineach of the pair of bodies 300, 301; 302, 303; 304, 305 of two outer heat transfersystem devices 100, in the stack of heat transfer devices 100, are interconnectedby a sealing element 400 extending along a lengthwise direction of the bodies 300;301302, 303, 304, 305. According to one embodiment, the pair of bodies areformed of succeeding or consecutive bodies. According to one embodiment, anentire sheet 4000 (not shown) of the sealing element 400 covers the entire surfaceportion 20a of the heat transfer device 100. According to one embodiment, theheat transfer devices 100 comprise an even number of plurality of bodies, whereinthe even number of plurality of bodies 300, 301 form pair of bodies 300; 301,wherein each of the pair of bodies 300; 301, of two outer heat transfer systemdevices 100, in the stack of heat transfer devices 100, are interconnected by asealing element 400 extending along a lengthwise direction of the bodies 300;301). The heat transfer system 1 formed in Fig. 9b and resulting from the methodof Fig. 9a, comprises a side 4, such as e.g. a cold side 4, and a side 5, such as awarm side 5 being formed by the channel 5. As seen in Fig. 9b according to oneembodiment, the heat transfer system 1 forms a plurality of cold sides 4 and warmsides 5. Any number of bodies 300 may be used in a heat transfer system 1according to the described embodiment. 69. 69. id="p-69" id="p-69"

[0069] Following a similar procedure as in Fig. 8a, 9a, by using a heat transferdevice 100 according to Fig. 1 results in a heat transfer system 1, as can be seenin Fig. 10a, further disclosing a cold side 4, and a warm side 5. According to oneembodiment, the heat transfer system 1 may e.g. be used for CPU heat sinks, e.g.in a fluid-contact heat transfer system 1. Fig. 1 discloses fibers 2 extending fromone surface 300a of the at least one body, i.e. the cold side 4. The opposite warmside 5 may be directly adjoined by the CPU, wherein the CPU contacts a cross-section of the fibers 2. Such structure is preferable in applications where heat istransferred from a warm object instead of between two fluids, e.g. from a CPU toambient air. According to one embodiment the application may also be used where space is very limited. 70. 70. id="p-70" id="p-70"

[0070] The heat transfer system 1 according to Fig. 10a may alternatively beformed by using the heat transfer device of Fig. 2 and applying a cut at the middleof the body 300 and along the length of the body 300. 71. 71. id="p-71" id="p-71"

[0071] Yet another embodiment, can be seen in Fig. 10b, wherein a similarprocedure is as in Fig. 8a, 9a, 10a is applied, by using a heat transfer device ofFig. 3 and applying a cut at the middle of the bodies 300, 301 and along the lengthof the body 300, 301. Herein, fibers are held in place by an upper and lower body,ensuring that they do not fold when a cooling fluid is forced through the fibers.Thus, according to one embodiment, the body provide structural integrity to the heat transfer system 1. 72. 72. id="p-72" id="p-72"

[0072] Fig. 11a shows a fluid duct 600 for directing a cooling fluid through fibers2 of a cold side 4 of a heat transfer device 1. According to one embodiment, theheat transfer device 1 is a heat transfer device 1 according to Fig. 10a. Coolingfluid flows through or enters the elongated duct at a portion 610, flows via aconnecting portion 620 configured to comprise the heat transfer device 1 andfurther comprises a duct opening 630 for enabling the cooling fluid to exit the fluidduct 600 after heat has been transferred to the cold side 4 from the warm side 5via the fibers 2, e.g via a CPU bearing against the end of the fibers 2 on the warmside 5. According to one embodiment, the connecting portion 620 has a wedge ló shape, such as e.g. a pyramidal shape of an increased cross -section area in thecooling fluid flow direction towards the duct opening 630, with the base comprisingthe heat transfer device 1. According to one embodiment, the pyramidal shapeenables a high fluid velocity through the fluid duct 600, through the narrowerportion 610 and further through the heat transfer device, which increases the heattransfer coefficient, but still enables the fitting of the heat transfer device 1, whichrequires a certain, larger space to comprise a sufficient number of fibers 2 andsurface area to provide a sufficient heat transfer efficiency. Fig. 11b shows anexploded side view of the fluid duct 600 according to Fig. 11a. Fig. 11c shows aside view, such as a front view, of the fluid duct 600 according to Fig.11a and 11band the duct opening 630. Fig 11d shows a side view, such as a rear view, of thefluid duct 600 according to Fig.11a-11c, Iacking the duct opening 630. 73. 73. id="p-73" id="p-73"

[0073] According to one embodiment, the sea|ing element 400 is formed by thesame material as the body material or materials. According to one embodiment,the sea|ing element 400 material is selected among the materials described herein for the body material. 74. 74. id="p-74" id="p-74"

[0074] A preferred embodiment of a heat transfer device 100 or heat transfersystem 1, use of a heat transfer device 100 or heat transfer system 1, a method ofpreparing a heat transfer device 1 or heat transfer system 100 according to theinvention has been described. However, the person skilled in the art realizes thatthis can be varied within the scope of the appended claims without departing from the inventive idea. 75. 75. id="p-75" id="p-75"

[0075] According to one embodiment, the heat transfer system is a heatexchanger. According to one embodiment, heat transfer devices and systemsdescribed are used in electronic systems, mechanical systems, computerimplemented systems, chemical systems and/or vehicle systems (including spacevehicles). According to one embodiment, heat transfer devices and systemsdescribed are configured to be used in electronic systems, mechanical systems,computer implemented systems, chemical systems and/or vehicle systems(including space vehicles). 17 76. 76. id="p-76" id="p-76"

[0076] A|| the described alternative embodiments above or parts of anembodiment can be freely combined without departing from the inventive idea as long as the combination is not contradictory.

Claims (24)

1. A heat transfer device (100) comprising at least one body (300, 301,302, 303, 304, 305) and thermally conducting fibers (2) extending through the atleast one body (300, 301, 302, 303, 304, 305) and extending out from the at leastone body (300, 301, 302, 303, 304, 305) from at least one surface (300a, 300b,301a, 301b, 302a, 302b, 303a, 303b, 304a, 304b, 305a, 305b) of the at least onebody (300, 301, 302, 303, 304, 305), wherein the thermally conducting fibers (2)have a length of at least 1 mm, wherein the thermally conducting fibers have aconductivity of at least 50 W/mK, wherein the thermally conducting fibers have adiameter of at least 4 micrometers.

2. The heat transfer device (100) according to claim 1, wherein the at leastone body (300, 301, 302, 303, 304, 305) comprises at least 30 vvt% non-metallicmaterial(s), preferably at least 70 wt % non-metallic material(s), more preferably atleast 90 wt% non-metallic material(s), most preferably 100 wt% non-metallicmaterial(s).

3. The heat transfer device (100) according any of the preceding claims,wherein the thermally conducting fibers (2) have a conductivity of 50-300 W/mK,preferably 301-799, more preferably 800-1000 W/mK.

4. The heat transfer device (100) according to any of the preceding claims,wherein the thermally conducting fibers (2) extend from at least two surfaces(300a, 300b) of the at least one body (300).

5. The heat transfer device (100) according to any of the preceding claims,wherein the thermally conducting fibers (2) comprises free ends (2c).

6. The heat transfer device (100) according to any of the preceding claims,wherein the thermally conducting fibers (2) preferably have a diameter of 4-15 micrometers, more preferably 7-10 micrometers. 19

7. The heat transfer device (100) according to any one of the precedingclaims, wherein the at least one body (300, 301, 302, 303, 304, 305) comprisesresin and/or thermoplastic materials.

8. The heat transfer device (100) according to any of the preceding claims, wherein the thermally conducting fibers (2) are carbon fibers.

9. The heat transfer device (100) according to any of the preceding claims,wherein the at least two surfaces (300a, 300b) of the at least one body (300, 301,302, 303, 304, 305) are opposing surfaces (300a, 300b).

10. The heat transfer device (100) according to any of the preceding claims,wherein the heat transfer device (100) comprises a plurality of bodies (300, 301,302, 303, 304, 305), wherein the thermally conducting fibers (2) extend throughthe plurality of bodies (300, 310, 320, 330, 340, 350).

11. The heat transfer device (100), according to claim 10, wherein thethermally conducting fibers (2) are extending out from each of the plurality ofbodies (300, 301, 302, 303, 304, 305) from a top and bottom surface (300a, 300b,301a, 301 b, 302a, 302b, 303a, 303b, 304a, 304b, 305a, 305b) respectively.

12. The heat transfer device (100), according to any of the preceding claims10-11, wherein the plurality of bodies (300, 301, 302, 303, 304, 305) arepositioned substantially equidistant from each other.

13. The heat transfer device (100) according to any of the preceding claims,wherein the heat transfer device (100) is in the form of a sheet (20).

14. Heat transfer system (1) comprising a plurality of heat transfer devices(100) according to any of the preceding claims 1-13 stacked to each other whereinthe at least one body or plurality of bodies (300, 301, 302, 303, 304, 305) of adjacent heat transfer devices (100) are bonded to each other.

15. The heat transfer system (1) according to claim 14 wherein at least asubset of consecutive bodies of the plurality bodies (300, 301, 302, 303, 304, 305)of the two outer heat transfer devices (100), in the stack of heat transfer devices (100) are interconnected by a sealing element (400) extending along a Iengthwisedirection of the bodies (300; 301, 302, 303, 304, 305).

16. Heat transfer system (1) according to any one of the previous preceding c|aims, wherein the heat transfer system (1) is a heat exchanger.

17. Use of the heat transfer device (100) or heat transfer system (1)according to any one of the preceding c|aims in electronic systems, mechanicalsystems, computer implemented systems, chemical systems and/or vehicle systems (including space vehicles).

18. Method of preparing a heat transfer device (100) according to any oneof the preceding c|aims 1-16 comprising the steps of: a. Positioning of thermally conducting fibers (2) directed in mainly onedirection in form of a sheet (20), wherein the thermally conducting fibers (2) arepreferably positioned substantially in parallel to each other, b. Positioning of at least one strip (30a, 30b, 31a, 31 b) of bodymaterial in substantially perpendicular direction to said thermally conducting fibers(2) on at least one side said sheet (20), wherein said body material comprisesmaterial or materials which result in said body (300) of the heat transfer device(100), c. Positioning of said sheet and said at least one strip (30a, 30b) of body material in a press device (500), d. Pressing said sheet 20 and said at least one strip (30a, 30b)against each other by the aid of the press device (500), e. Administering heat to said sheet (20) and said at least one strip(30a, 30b) before or inside the press device (500), wherein the heat turns saidstrip (30a, 30b) into a substantially viscous material which is forced into said sheet(20) and thereby creating a body (300) forming a seal between two sides (4, 5) ofsaid sheet (20), and 21 f. Pulling out the resulting heat transfer device (100) out from the press device (500),

19. Method according to claim 18, wherein a plurality of strips (30a, 31a;30b, 31 b) of body material is positioned on said sheet (20), and wherein the strips(30b, 31 b), are positioned preferably substantially equidistant from each other.

20. Method according to any of the preceding claims 18-19, wherein thethermally conducting fibers are being pulled from a number of large rolls (200) withbundled fibers (2).

21. Method according to any of the preceding claims18-20, wherein a newpart of the sheet (20) having body material positioned on the sheet (20) ispositioned into the press device (500) at the same time as the resulting heat transfer device (100) is pulled out from the press device (500).

22. Heat transfer device (500) prepared by a method according to any one of the preceding claims 18-21.

23. Method of preparing a heat transfer system (1) comprising a plurality ofheat transfer devices (100) according to any of the preceding claims 1-13, 18-22, comprising the steps:- Stacking a plurality of heat transfer devices (100) to each other, - Bonding bodies (300, 301, 302, 303, 304, 305) of adjacent heat transfer devices (100) to each other.

24. Method according to claim 23, further comprising: -interconnecting at least a subset of consecutive bodies (300, 301, 302, 303, 304,305) of the two outer heat transfer devices 100 in the stack of heat transfer devices 100 by a sealing element (400).