[go: up one dir, main page]

WO2017107191A1 - Heat exchange material, apparatus and system - Google Patents

Heat exchange material, apparatus and system Download PDF

Info

Publication number
WO2017107191A1
WO2017107191A1 PCT/CN2015/098937 CN2015098937W WO2017107191A1 WO 2017107191 A1 WO2017107191 A1 WO 2017107191A1 CN 2015098937 W CN2015098937 W CN 2015098937W WO 2017107191 A1 WO2017107191 A1 WO 2017107191A1
Authority
WO
WIPO (PCT)
Prior art keywords
heat
heat exchange
exchange apparatus
array
fine
Prior art date
Application number
PCT/CN2015/098937
Other languages
French (fr)
Inventor
Kechuang Lin
Yi-Jui Huang
Original Assignee
Kechuang Lin
Yi-Jui Huang
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kechuang Lin, Yi-Jui Huang filed Critical Kechuang Lin
Priority to PCT/CN2015/098937 priority Critical patent/WO2017107191A1/en
Priority to CN201580081623.9A priority patent/CN107835928A/en
Publication of WO2017107191A1 publication Critical patent/WO2017107191A1/en

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
    • F28F13/003—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by using permeable mass, perforated or porous materials
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
    • F28F13/18—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by applying coatings, e.g. radiation-absorbing, radiation-reflecting; by surface treatment, e.g. polishing
    • F28F13/185—Heat-exchange surfaces provided with microstructures or with porous coatings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F3/00—Plate-like or laminated elements; Assemblies of plate-like or laminated elements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21K—NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
    • F21K9/00—Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
    • F21K9/20—Light sources comprising attachment means
    • F21K9/23—Retrofit light sources for lighting devices with a single fitting for each light source, e.g. for substitution of incandescent lamps with bayonet or threaded fittings
    • F21K9/232—Retrofit light sources for lighting devices with a single fitting for each light source, e.g. for substitution of incandescent lamps with bayonet or threaded fittings specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V29/00—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems
    • F21V29/85—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems characterised by the material
    • F21V29/89—Metals
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00—Light-generating elements of semiconductor light sources
    • F21Y2115/10—Light-emitting diodes [LED]

Definitions

  • a heat exchange apparatus typically transfers heat from a heat source to a medium, such as air, water, oil or a refrigerant.
  • Heat exchange apparatuses have been widely used in various mechanic and electronic devices in industries such as air conditioning, refrigeration, and power plants, refineries, and sewage treatment.
  • a heat exchange apparatus is typically designed to increase surface areas in order to facilitate convection for better dissipation of heat from a heat source.
  • Metal foams are a porous heat exchange material that is often employed to construct heat exchange apparatuses because their high porosity leads to both increased heat-dissipating surface areas and better convection.
  • the present disclosure relates to a heat exchange material, and specifically to a fine-array porous heat exchange material, and also to its application in heat exchange apparatuses or systems.
  • the heat exchange material typically comprises a fine-array porous material, composed of a metal, such as Ni, Al, Cu, Au, Ag, Ti or Fe, or of an alloy, such as an aluminum alloy, a copper alloy or a nickel alloy, or of a metal/metal oxide composite, such as Ti/TiO 2 and Al/Al 2 O 3 .
  • the fine-array porous material comprises a plurality of pores, wherein the plurality of pores have a size of less than about 5000 ⁇ m; the size of the plurality of pores is substantially uniform with a variation of less than about 20%; and the fine-array porous material has a porosity of about 40-85%.
  • a heat exchange material may comprise a fine-array porous material having a porosity of about 74%.
  • such a fine-array porous heat exchange material can achieve a much better conduction/radiation-mediated heat dissipation because of a much higher heat dissipating surface area due to the significantly higher surface-area-to-volume ratio of the fine-array porous heat exchange material.
  • the fine-array porous material is composed of a metal/metal oxide composite, such as Ti/TiO 2 and Al/Al 2 O 3
  • the fine-array porous heat exchange material as such can also achieve greatly improved thermal radiation, attributable primarily to the presence of metal oxide on the outer surface of the metallic fine-array porous heat exchange material. This advantage is especially important in situations where efficient convection cannot to be achieved and thermal radiation is a primary way of heat dissipation.
  • the heat exchange apparatus typically includes a heat conduction layer and at least one heat dissipation layer.
  • the heat conduction layer typically comprises a heat conductive material, composed of a metal, an alloy, a heat-conductive ceramics, or a heat-conductive polymer; each of the at least one heat dissipation layers comprises a fine-array porous heat exchange material as disclosed above.
  • the heat conduction layer is disposed on and thermally contacts the at least one heat dissipation layer to thereby thermally transfer heat from a higher temperature medium in contact with the heat conduction layer to a lower temperature medium in contact with the at least one heat dissipation layer.
  • a heat exchange apparatus may include only one heat dissipation layer, comprising one type of fine-array porous heat exchange material.
  • a heat exchange apparatus may comprise two heat dissipation layers: a first heat dissipation layer and a second heat dissipation layer, comprising two types of fine-array porous heat exchange materials with different pore sizes.
  • the first heat dissipation layer typically has a smaller pore size and is disposed on and thermally contacts the heat conduction layer, whereas the second heat dissipation layer has a larger pore size than the first heat dissipation layer and is disposed over the first heat dissipation layer.
  • the second heat dissipation layer and the first heat dissipation layer has a pore size ratio of about 2: 1 -1000: 1; and the second heat dissipation layer and the first heat dissipation layer has a thickness ratio of about 0.01: 1 -1000: 1, the thickness ratio depending on the pore sizes of the first heat dissipation layer and of the second heat dissipation layer.
  • a heat exchange apparatus may be a heat sink, including a heat sink main body and at least one heat dissipation layer, each of the at least one heat dissipation layer comprising one type of fine-array porous heat exchange materials as disclosed above.
  • the heat sink main body comprises a base and an array of extrusions, wherein the array of extrusions are configured to extend from the base and are spaced apart with open gaps; and the at least one heat dissipation layer is coated on the heat sink main body.
  • the array of extrusions of the heat sink main body may be an array of fins or an array of pins, and may have a flared configuration to improve convection-mediated heat dissipation.
  • the array of fins may comprise an array of alternately placed long and short fins, forming a more dense array at the base end and a more loose array at the open end, allowing a favorable formation of heat gradients from the base end to the open end to thereby achieve a more efficient convection cooling.
  • the heat conduction layer and the at least one fine-array porous heat dissipation layer may take a form of enclosed tube and the heat exchange apparatus essentially forms a heat exchanger tube such as a condenser.
  • the heat conduction layer is disposed on an inside face of the heat exchange apparatus; and the at least one fine-array porous heat dissipation layer is disposed on an outside face of the heat exchange apparatus to thereby thermally transfer heat from a higher temperature medium inside the heat exchange apparatus to a lower temperature medium outside the heat exchange apparatus.
  • the heat conduction layer is disposed on an outside face of the heat exchange apparatus; and the at least one fine-array porous heat dissipation layer is disposed on an inside face of the heat exchange apparatus to thereby thermally transfer heat from a higher temperature medium outside the heat exchange apparatus to a lower temperature medium inside the heat exchange apparatus.
  • the heat sink system substantially comprises a heat exchange apparatus, which provides a housing for and thermally contacts the LED light source.
  • the heat exchange apparatus may comprise an inner heat conduction layer and an outer heat dissipation layer, wherein the outer heat dissipation layer comprises substantially a fine-array porous heat exchange material as disclosed above and is disposed on and thermally contacts the outside face of the inner heat conduction layer.
  • the outer heat dissipation layer may comprise more than one layer of fine-array porous heat exchange materials, and may be configured such that the inner-most layer has the smallest pore size and each of the other layers has an increasing pore size compared with the layer disposed thereinside, in order to achieve an improved convection-mediated heat dissipation.
  • the heat sink system substantially comprises a heat exchange apparatus, which thermally contacts the electronic circuit to dissipate heat from the electronic circuit.
  • the heat sink apparatus comprises a heat conduction layer and a heat dissipation layer, wherein the heat dissipation layer comprises substantially a layer of fine-array porous heat exchange material.
  • the heat sink system also includes a fan, wherein the fan is disposed on the heat exchange apparatus to further facilitate heat dissipation.
  • the heat sink system may comprise more than one layer of fine-array porous heat exchange materials, configured such that the inner-most layer that contacts the electronic circuit has the smallest pore size and each of the other layers has an increasing pore size compared with the layer disposed therebeneath, in order to achieve an improved convection-mediated heat dissipation.
  • a heat radiation system for warming ambient from a heat source is also disclosed herein, which substantially comprises a heat exchange apparatus, configured to thermally contact the heat source and to dissipate heat from the heat source to the ambient.
  • the ambient can be air, a liquid like water, or an oil.
  • the heat radiation apparatus comprises a heat conduction layer and a heat dissipation layer, wherein the heat dissipation layer comprises substantially a layer of fine-array porous heat exchange material as disclosed above.
  • the heat radiation system may comprise more than one layer of fine-array porous heat exchange materials, configured such that the inner-most layer that contacts the heat source has the smallest pore size and each of the other layers has an increasing pore size compared with the layer disposed therebeneath, in order to achieve an improved convection-mediated heat dissipation.
  • FIG. 1 illustrates conventional heat sink apparatuses having cooling fins (A) or cooling pins (B) .
  • FIG. 2 illustrates conventional heat sink apparatuses having designs for improved convection.
  • FIG. 3 illustrates a metal foam heat sink apparatus and the microstructure of the metal foam used as a heat sink material in the apparatus.
  • FIG. 4 illustrates a heat sink apparatus comprising a fine-array porous heat exchange material according to some embodiments of this disclosure.
  • FIG. 5 illustrates a heat sink apparatus comprising a double-layer fine-array porous heat dissipator.
  • FIG. 6 illustrates one type of heat exchanger tube comprising fine-array porous heat exchange materials according to some embodiments of this disclosure.
  • FIG. 7 illustrates another type of heat exchanger tube 600 comprising fine-array porous heat exchange materials according to some embodiments of this disclosure.
  • FIG. 8 illustrates a LED light bulb comprising a fine-array porous heat sink apparatus.
  • FIG. 9 illustrates a CPU heat sink system 900 comprising a fine-array porous heat exchange materials according to some embodiments of this disclosure.
  • FIG 10 illustrates a heat sink apparatus having fine-array porous heat exchange material according to some embodiment.
  • a heat exchange apparatus typically transfers heat from a heat source to a medium in the ambient, such as air, water, oil or a refrigerant.
  • Some common heat exchange apparatuses may include a heat sink, typically used to cool a device such as an LED light source and a CPU processor, a condenser, typically used in an air conditioner and refrigerator to transfer heat, and a heat radiator, typically used to radiate heat from a heat source.
  • FIG. 1 illustrates conventional heat sink apparatuses having cooling fins (A) , or cooling pins (B) .
  • a conventional heat sink apparatus 100 may comprise a base 102 and an array of fins 103, wherein the base 102 is in touch with a heat source 101, the array of fins 103 is configured such that the array of fins vertically extend from the base 102 and are spaced apart with open gaps 104.
  • this type of conventional heat sink apparatus 100 can effectively dissipate heat produced by the heat source 101 by conduction of and radiation from the array of fins 103, and by convection mediated by flow of air in the open gaps 104 between fins.
  • fins are sometimes treated to have an undulating or serrated surface 105.
  • an array of pins 111 are used to replace the array of fins 103 in the heat sink apparatus 100 in FIG. 1A, which vertically extend from a base 112 and are spaced apart.
  • FIG. 2 illustrates conventional heat sink apparatuses having designs for improved convection.
  • a heat sink apparatus 200 may comprise a base 202 and an array of alternately placed long and short fins 203, wherein the base 202 is in touch with a heat source 201, the array of alternately placed long and short fins 203 is configured such that the fins vertically extend from the base 202 and are spaced apart with open gaps 204.
  • the array of alternately placed long and short fins 203 substantially form a more dense array at the base end 205 and a more loose array at the open end 206, essentially allowing a favorable formation of heat gradients from the base end 205 to the open end 206.
  • a conventional heat sink apparatus with such improved design 200 can achieve more efficient convection cooling compared with a conventional heat sink apparatus with a regular design 100 (FIG. 1A) .
  • a heat sink apparatus with such a design 200 has a reduced surface area for heat dissipation mediated by conduction and radiation.
  • a heat sink apparatus 210 may comprise an array of fins 211, wherein the array of fins 211 have a flared configuration to thereby achieve an efficient convection cooling.
  • a heat sink apparatus 220 may comprise an array of flared pins 221 to also achieve an efficient convection cooling.
  • FIG. 3 illustrates a metal foam heat sink apparatus and the microstructure of the metal foam used as a heat sink material used in the apparatus.
  • the metal foam heat sink apparatus 300 may include a heat conductive substrate 301 and a metal foam heat dissipator 302, wherein the heat conductive substrate 301 is in touch with a heat source 305, the metal foam heat dissipator 302 is disposed over and is in thermal contact with the heat conductive substrate 301, and the metal foam heat dissipator 302 substantially comprises a metal foam material.
  • the metal foam material used in the metal foam heat dissipator 302 typically comprises an interconnected matrix of metallic ligaments 303 with varying lengths and orientations, and individual void spaces (pores) 304 of different shapes and sizes are formed between adjacent ligaments.
  • Typical metal foams may have pore sizes of 0.5-8 mm, with a variation often higher that 100%.
  • a metal foam heat sink apparatus 300 typically achieves better conduction/radiation-mediated heat dissipation due to the much larger relative surface area of the metal foam heat dissipator 302.
  • a metal foam heat sink apparatus 300 is usually less capable of achieving efficient convection-mediated heat dissipation due to the typically irregular shapes and sizes of the void spaces (pores) 304 formed in the metal foam heat dissipator 302.
  • FIG. 4A illustrates a heat sink apparatus comprising a fine-array porous heat exchange material according to some embodiments of this disclosure.
  • the heat sink apparatus 400 comprise a heat conductor 401 and a heat dissipator 402, wherein the heat conductor 401 comprises a heat conductive material, the heat dissipator 402 comprises a fine-array porous heat exchange material, and the heat dissipator 402 is configured to dispose over and thermally contact with the heat conductor 401 such that the heat conductor 401 thermally transfers heat from a heat source 405 to the heat dissipator 402 for dissipation into the air.
  • the heat conductive material 402 used in the heat conductor 401 may be a metal, such as Cu, Ni, Fe, Al, Au, Ag, Ti or Fe, an alloy, such as an aluminum alloy, or a copper alloy, or a heat conductive composite metal/metal oxide, such as Ti/TiO 2 and Al/Al 2 O 3 .
  • the fine-array porous heat exchange material used in the heat dissipator 402 may be made of the heat conductive material as used in the heat conductor 401 (please confirm) , and may contain highly packed and substantially uniform pores 404, as shown in a 2D view 403.
  • the pores can have sizes of, for example, about 10 ⁇ m –1 cm, and preferably about 100 ⁇ m –1 mm, and can have a porosity of 40 -85%, preferably about 68-74%.
  • the size of the pores in the fine-array porous heat exchange material is substantially uniform with a variation of less than about 20%and preferably of less than about 10%.
  • the fine-array porous heat exchange material can be a fine-array porous heat exchange membrane, having a thickness of 200 ⁇ m -10 cm, and preferably of 500 ⁇ m -1000 ⁇ m.
  • the fine-array porous heat exchange material can have a surface area larger than 100 cm 2 , such as 20 cm ⁇ 20 cm.
  • a heat sink apparatus 400 as disclosed herein typically can achieve a much better conduction/radiation-mediated heat dissipation because of a much higher heat dissipating surface area due to the significantly higher surface-area-to-volume ratio of the fine-array porous heat exchange material used in the heat dissipator.
  • a fine-array porous heat sink as disclosed herein can have a surface-area-to-volume ratio of 40-85%, whereas a conventional heat sink and a metal foam heat sink may have such a ratio ranging 5-15%and 15 ⁇ 30%, respectively.
  • flow of air within the pores can achieve a laminar flow, a feature substantially preventing local heat accumulation and allowing more efficient convection cooling of a fine-array porous heat sink apparatus compared with a metal foam heat sink apparatus.
  • a fine-array porous heat sink 410 may comprise two fine-array porous heat dissipators 412 disposed over and thermally contacting both surfaces of the heat conductor 411 to further increase the heat-dissipating surface area.
  • the heat dissipator may comprise multiple layers of fine-array porous heat exchange material with different pore sizes.
  • FIG. 5A illustrates a heat sink apparatus having a double-layer fine-array porous heat dissipator.
  • This heat sink apparatus 500 comprises a heat conductor 501 and a heat dissipator 502, wherein the heat dissipator 502 is configured to dispose over and thermally contact the heat conductor 501 such that the heat conductor 501 thermally transfers heat from a heat source 505 to the heat dissipator 502 for dissipation into air.
  • the heat dissipator 502 substantially comprises a first layer of fine-array porous heat exchange material 503 and a second layer of fine-array porous heat exchange material 504, configured such that the first layer of fine-array porous heat exchange material 503 has a smaller pore size and is in thermal contact with the heat conductive layer 501, and that the second layer of fine-array porous heat exchange material 504 is disposed over the first layer of fine-array porous heat exchange material 503 and has a larger pore size.
  • the ratio of pore sizes of the second layer 504 and the first layer 503 can be 2: 1 -1000: 1, and the ratio of thickness of the second layer 504 and the first layer 503 can be 0.01: 1 -1000: 1 depending on the pore sizes of the two layers.
  • the double-layer fine-array porous heat sink apparatus 500 in addition to an efficient conduction/radiation-mediated heat dissipation due to the large relative surface area of the fine-array porous heat exchange material used in the heat dissipator, can achieve an improved convection-mediated heat dissipation due to the favorable establishment of a heat gradient along the direction of air flow within the pores from the first layer 503 to the second layer 504 of the heat dissipator 502.
  • the fine-array porous heat sink apparatus may contain more than two layers of fine-array porous heat dissipator such that the first layer has the smallest pore size and is in thermal contact with the heat source, and that each of the other layers has an increasing pore size compared with the layer disposed therebeneath.
  • a fine-array porous heat sink 510 may comprise two double-layer heat dissipators 512, disposed over and thermally contacting both surfaces of the heat conductor 511 to further increase the heat-dissipating surface area.
  • Each of the double-layer heat dissipator 512 comprises a first layer of fine-array porous heat exchange material 513 and a second layer of fine-array porous heat exchange material 514, configured such that the first layer of fine-array porous heat exchange material 513 has a smaller pore size and is in thermal contact with the heat conductive layer 511, and that the second layer of fine-array porous heat exchange material 514 is disposed over the first layer of fine-array porous heat exchange material 513 and has a larger pore size.
  • This configuration allows efficient heat dissipation by both increasing the heat-dissipating surface area of the heat sink apparatus 510.
  • FIG. 6 illustrates one type of heat exchanger tube 600 comprising fine-array porous heat exchange materials according to some embodiments of this disclosure, with their cross-sectional views shown.
  • the heat exchanger tube 600 comprises an inner heat conduction tube 602 and an outer heat dissipation tube 603, wherein the inner heat conduction tube 602 comprises a heat conductive material, the outer heat dissipation tube 603 comprises a fine-array porous heat exchange material, and the outer heat dissipation tube 603 is disposed on and thermally contacts the outside face of the inner heat conduction tube 602 such that the inner heat conduction tube 602 transfers heat from a first medium 604 flowing through the inner heat conduction tube 602 to the outer heat dissipation tube 603 for dissipation into a second medium 605 outside the outer heat dissipation tube 603.
  • the inner heat conduction tube 602 may have a thickness of 5 ⁇ m –10 cm, and may comprise a metal, such as Cu, Ni, Fe, Al, etc, in some embodiments, or a heat conductive ceramics, such as AlN, Al 2 O 3 in some other embodiments.
  • the outer heat dissipation tube 603 may have a thickness of 0.5 ⁇ m –1 cm, and the fine-array porous heat exchange material used for the outer heat dissipation tube 603 may be made of a metal, such as Cu, Ni, Fe or Al in some embodiments, or a heat conductive ceramics/polymers in some other embodiments.
  • the fine-array porous heat exchange material used in the outer heat dissipation tube 603 has technical parameters similar to that in the fine-array porous heat sink apparatus 400 shown in FIG. 4.
  • the outer heat dissipation tube 603 may comprise more than one layer of fine-array porous heat exchange materials. In one such embodiment illustrated in FIG.
  • the outer heat dissipator tube comprises a first layer of fine-array porous heat exchange material 613 and a second layer of fine-array porous heat exchange material 614, wherein the first layer of fine-array porous heat exchange material 613 has a smaller pore size and is disposed on the outside face of the inner heat conductor tube 612, and the second layer of fine-array porous heat exchange material 614 has a larger pore size and is disposed on the outside face of the first layer of fine-array porous heat exchange material 613.
  • This configuration can achieve an improved convection-mediated heat dissipation in a mechanism similar to the heat sink apparatus 500 as disclosed in FIG. 5A.
  • FIG. 7 illustrates another type of heat exchanger tube 700 comprising fine-array porous heat exchange materials according to some embodiments of this disclosure, with cross-sectional views shown.
  • the heat exchanger tube 700 comprises an inner heat dissipation tube 702 and an outer heat conduction tube 703, wherein the inner heat dissipation tube 702 comprises a fine-array porous heat exchange material, the outer heat conduction tube 703 comprises a heat conductive material, and the outer heat conduction tube 703 is disposed on and thermally contacts the outside face of the inner heat dissipation tube 702 such that the outer heat conduction tube 703 transfers heat from a first medium 705 outside the outer heat conduction tube 703 to the inner heat dissipation tube 702 for dissipation into a second medium 704 flowing through the inner heat dissipation tube 702.
  • the outer heat conduction tube 703 may have a thickness of 5 ⁇ m –10 cm, and may comprise a metal, such as Cu, Ni, Fe, Al, etc, in some embodiments, or a heat conductive ceramics/polymers, such as AlN and Al 2 O 3 in some other embodiments.
  • the inner heat dissipation tube 702 may have a thickness of 0.5 ⁇ m –1 cm, and the fine-array porous heat exchange material used for the inner heat dissipation tube 702 may be made of a metal, such as Cu, Ni, Fe or Al in some embodiments, or a heat conductive ceramics/polymers in some other embodiments.
  • the fine-array porous heat exchange materials used in the inner heat dissipation tube 702 have technical parameters similar to that in the fine-array porous heat sink apparatus 400 shown in FIG 4.
  • the inner heat dissipation tube 702 may comprise more than one layer of fine-array porous heat exchange materials.
  • FIG. 1 illustrates one embodiment of the inner heat dissipation tube 702
  • the heat exchange tube 710 comprises an outer heat conduction tube 713, a first layer of fine-array porous heat exchange material 712, and a second layer of fine-array porous heat exchange material 714, wherein the first layer of fine-array porous heat exchange material 712 has a smaller pore size and is disposed on and thermally contacts the inside face of the heat conductor tube 713, the second layer of fine-array porous heat exchange material 714 has a larger pore size and is disposed on the inside face of the first layer of fine-array porous heat exchange material 712.
  • This configuration can achieve an improved convection-mediated transfer of heat from outside medium to the inside medium, in a mechanism similar to the heat sink apparatus 500 as disclosed in FIG. 5A.
  • FIG. 8 illustrates a LED light bulb 800 comprising a fine-array porous heat sink apparatus, with its cross-section view of the heat sink 810 shown.
  • the LED light bulb 800 comprises a bulb body 801 and a bulb housing 802, wherein the bulb housing 802 encloses and thermally contacts the bulb body 801.
  • the bulb housing 802 comprising an inner heat conduction layer 812 and an outer heat dissipation layer 811, wherein the inner heat conduction layer 812 comprises a heat conductive material and the outer heat dissipation layer 811 comprises substantially a fine-array porous heat exchange material and the outer heat dissipation layer 811 is disposed on and thermally contacts the outside face of the inner heat conduction layer 812 such that the inner heat conduction layer 812 transfers heat from the LED light bulb to the outer heat dissipation layer 811 for dissipation into the air.
  • the outer heat dissipation layer 802 may comprise more than one layer of fine-array porous heat exchange materials, configured in a manner similar to the heat exchanger tube 610 disclosed in FIG. 6, in order to achieve an improved convection- mediated heat dissipation, facilitated by the favorable establishment of a heat gradient across the different layers of the fine-array porous heat exchange materials.
  • FIG. 9 illustrates a CPU heat sink system 900 comprising fine-array porous heat exchange materials according to some embodiments of this disclosure.
  • the CPU heat sink system 900 comprises a heat sink apparatus 903 and a fan 904, wherein the heat sink apparatus 903 is sandwiched between and thermally contacts a CPU chip 902, mounted on a substrate 901, and the fan 904 such that heat released from the CPU chip 902 is transferred to the heat sink apparatus 903, and is dissipated in the air facilitated by the fan 904.
  • the heat sink apparatus 903 comprises a heat conduction layer 905, having a thickness of 1 ⁇ m -1000 ⁇ m, and a heat dissipation layer 906, having a thickness of 500 ⁇ m –10 cm, wherein the heat conduction layer 905 comprises a heat conductive material, the heat dissipation layer 906 comprises a layer of fine-array porous heat exchange material.
  • the fine-array porous heat exchange material may have a pore size of about 10 ⁇ m –1 cm, preferably about 100 ⁇ m –1 mm, and may have a porosity of 40 -85%, preferably about 68-74%.
  • the size of the pores in the fine-array porous heat exchange material is substantially uniform with a variation of less than about 20%and preferably of less than about 10%.
  • the CPU heat sink system 910 has a similar configuration with the CPU heat sink system 900, having a heat sink apparatus 913 disposed between a CPU chip 912 and a fan 914.
  • the heat sink apparatus 913 also comprises a double-layer heat dissipation layer 916, wherein the double-layer heat dissipation layer 916 comprises two layers of fine-array porous heat exchange materials, with a top layer 917 contacting the fan 914 and having a larger pore size, and a bottom layer 918 contacting the heat conduction layer 915 and having a smaller pore size.
  • the heat dissipation layer of the heat sink apparatus may comprises more than two layers of fine-array porous heat exchange materials, having an increasing pore size across the different layers of fine-array porous heat exchange materials along the direction from the heat conduction layer-contacting surface to the fan-contacting surface.
  • a heat sink comprising fine-array porous heat exchange materials may be employed to effectively cool a cloud computing device, such as cloud servers and cloud data centers.
  • FIG. 10 illustrates a heat sink apparatus having fine-array porous heat exchange material according to some embodiment.
  • the heat sink apparatus 1000 has substantially a similar basic structure as in the conventional heatsink 200 as illustrated in FIG. 2A, comprising a base 1002 and an array of alternately placed long and short fins 1003, wherein the base 1002 is in thermal touch with a heat source 1001, the array of alternately placed long and short fins 1003 is configured such that the fins vertically extend from the base 1002 and are spaced apart with open gaps 1004.
  • each of the array of alternately placed long and short fins 1003 in the heat sink 1000 also form a more dense array at the base end 1005 and a more loose array at the open end 1006, allowing a favorable formation of heat gradients from the base end 1005 to the open end 1006 to thereby achieve an efficient convection cooling.
  • a unique feature of the heat sink apparatus 1000 is that each of the array of alternately placed long and short fins 1003 comprises a heat conductive fin body 1007 and a layer of fine-array porous heat exchange material 1008 disposed over and thermally contacting the heat conductive fin body 1007, allowing each of the fins 1003 to essentially form a heat sink as shown in FIG. 3.
  • the heat sink 1000 can also achieve an efficient convection cooling both locally on each of the fins 1003, and on the whole structure of the heat sink 1000.
  • the heat sink 1000 may have another layer of fine-array porous heat exchange material, disposed on the outside of the layer of fine-array porous heat exchange material 1008 and having a larger pore size.
  • the heat sink apparatus 1000 may comprises more than two layers of fine-array porous heat exchange materials disposed over and thermally contacting the heat conductive fin body 1007, having an increasing pore size across the different layers of fine-array porous heat exchange materials along the inner-most to the outer-most direction.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Cooling Or The Like Of Electrical Apparatus (AREA)
  • Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)

Abstract

A fine-array porous heat exchange material (503, 504, 513, 514, 613, 614, 712, 714, 1008), which comprises a plurality of pores having a substantially uniform size of <1000μm, with a variation of <20%, having a porosity of about 40-85%, and may comprise a metal or an alloy. A heat exchange apparatus (400, 500, 510, 903, 913) comprising a fine-array porous heat exchange material (503, 504, 513, 514, 613, 614, 712, 714, 1008) have significantly improved heat dissipation due to its dramatically increased surface areas and/or improved convection, and can be applied in a heat sink system (810, 900, 910, 1000) for cooling a LED light source (801) or a CPU processor (902) or in a heat radiation system for warming ambient from a heat source (1001).

Description

HEAT EXCHANGE MATERIAL, APPARATUS AND SYSTEM BACKGROUND
A heat exchange apparatus typically transfers heat from a heat source to a medium, such as air, water, oil or a refrigerant. Heat exchange apparatuses have been widely used in various mechanic and electronic devices in industries such as air conditioning, refrigeration, and power plants, refineries, and sewage treatment.
A heat exchange apparatus is typically designed to increase surface areas in order to facilitate convection for better dissipation of heat from a heat source. Metal foams are a porous heat exchange material that is often employed to construct heat exchange apparatuses because their high porosity leads to both increased heat-dissipating surface areas and better convection.
SUMMARY
The present disclosure relates to a heat exchange material, and specifically to a fine-array porous heat exchange material, and also to its application in heat exchange apparatuses or systems.
Disclosed herein provides a heat exchange material for use in a heat exchange apparatus, such as a heat exchanger or a heat sink. The heat exchange material typically comprises a fine-array porous material, composed of a metal, such as Ni, Al, Cu, Au, Ag, Ti or Fe, or of an alloy, such as an aluminum alloy, a copper alloy or a nickel alloy, or of a metal/metal oxide composite, such as Ti/TiO2 and Al/Al2O3. The fine-array porous material comprises a plurality of pores, wherein the plurality of pores have a size of less than about 5000 μm； the size of the plurality of pores is substantially uniform with a variation of less than about 20％； and the fine-array porous material has a porosity of about 40-85％. In some preferred embodiments, a heat exchange material may comprise a fine-array porous material having a porosity of about 74％. Compared with conventional and metal foam heat exchange materials, such a fine-array porous heat exchange material can achieve a much better conduction/radiation-mediated heat dissipation because of a much higher heat dissipating surface area due to the significantly higher surface-area-to-volume ratio of the fine-array porous heat exchange material. In embodiments where the fine-array porous material is composed of a metal/metal oxide composite, such as Ti/TiO2 and Al/Al2O3, besides the above mentioned advantages, the fine-array porous heat exchange material as such can also achieve greatly improved thermal radiation, attributable primarily to the  presence of metal oxide on the outer surface of the metallic fine-array porous heat exchange material. This advantage is especially important in situations where efficient convection cannot to be achieved and thermal radiation is a primary way of heat dissipation.
Disclosed herein also includes a heat exchange apparatus that comprises a fine-array porous heat exchange material as disclosed above. The heat exchange apparatus typically includes a heat conduction layer and at least one heat dissipation layer. The heat conduction layer typically comprises a heat conductive material, composed of a metal, an alloy, a heat-conductive ceramics, or a heat-conductive polymer； each of the at least one heat dissipation layers comprises a fine-array porous heat exchange material as disclosed above. The heat conduction layer is disposed on and thermally contacts the at least one heat dissipation layer to thereby thermally transfer heat from a higher temperature medium in contact with the heat conduction layer to a lower temperature medium in contact with the at least one heat dissipation layer.
In some embodiments, a heat exchange apparatus may include only one heat dissipation layer, comprising one type of fine-array porous heat exchange material. In some other embodiments, a heat exchange apparatus may comprise two heat dissipation layers: a first heat dissipation layer and a second heat dissipation layer, comprising two types of fine-array porous heat exchange materials with different pore sizes. The first heat dissipation layer typically has a smaller pore size and is disposed on and thermally contacts the heat conduction layer, whereas the second heat dissipation layer has a larger pore size than the first heat dissipation layer and is disposed over the first heat dissipation layer. This configuration allows the favorable establishment of a heat gradient along the direction of air flow within the pores from the first heat dissipation layer to the second heat dissipation layer, thereby achieving an efficient convection-mediated heat dissipation. In some embodiments, the second heat dissipation layer and the first heat dissipation layer has a pore size ratio of about 2: 1 -1000: 1； and the second heat dissipation layer and the first heat dissipation layer has a thickness ratio of about 0.01: 1 -1000: 1, the thickness ratio depending on the pore sizes of the first heat dissipation layer and of the second heat dissipation layer.
In some embodiments, a heat exchange apparatus may be a heat sink, including a heat sink main body and at least one heat dissipation layer, each of the at least one heat dissipation layer comprising one type of fine-array porous heat exchange materials as disclosed above. The heat sink main body comprises a base and an array of extrusions, wherein the array of extrusions are configured to extend from the base and are spaced apart with open gaps； and the at least one heat dissipation layer is coated on the heat sink main body. The array of extrusions of the heat sink main body may be an array of fins or an array  of pins, and may have a flared configuration to improve convection-mediated heat dissipation. According to some embodiments of a heat exchange apparatus as such, the array of fins may comprise an array of alternately placed long and short fins, forming a more dense array at the base end and a more loose array at the open end, allowing a favorable formation of heat gradients from the base end to the open end to thereby achieve a more efficient convection cooling.
According to some embodiments of a heat exchange apparatus, the heat conduction layer and the at least one fine-array porous heat dissipation layer may take a form of enclosed tube and the heat exchange apparatus essentially forms a heat exchanger tube such as a condenser. In some embodiments, the heat conduction layer is disposed on an inside face of the heat exchange apparatus； and the at least one fine-array porous heat dissipation layer is disposed on an outside face of the heat exchange apparatus to thereby thermally transfer heat from a higher temperature medium inside the heat exchange apparatus to a lower temperature medium outside the heat exchange apparatus. Yet in some other embodiments, the heat conduction layer is disposed on an outside face of the heat exchange apparatus； and the at least one fine-array porous heat dissipation layer is disposed on an inside face of the heat exchange apparatus to thereby thermally transfer heat from a higher temperature medium outside the heat exchange apparatus to a lower temperature medium inside the heat exchange apparatus.
This disclosure also provides a heat sink system for cooling a LED light source in a LED light assembly. The heat sink system substantially comprises a heat exchange apparatus, which provides a housing for and thermally contacts the LED light source. The heat exchange apparatus may comprise an inner heat conduction layer and an outer heat dissipation layer, wherein the outer heat dissipation layer comprises substantially a fine-array porous heat exchange material as disclosed above and is disposed on and thermally contacts the outside face of the inner heat conduction layer. By this configuration, the inner heat conduction layer can efficiently transfer heat from the LED light source to the outer heat dissipation layer for dissipation into the air. In some embodiments, the outer heat dissipation layer may comprise more than one layer of fine-array porous heat exchange materials, and may be configured such that the inner-most layer has the smallest pore size and each of the other layers has an increasing pore size compared with the layer disposed thereinside, in order to achieve an improved convection-mediated heat dissipation.
This disclosure also provides a heat sink system for cooling an electronic circuit, such as a CPU chip or a chip used in a variety of personal and cloud computing devices. The heat sink system substantially comprises a heat exchange apparatus, which thermally  contacts the electronic circuit to dissipate heat from the electronic circuit. The heat sink apparatus comprises a heat conduction layer and a heat dissipation layer, wherein the heat dissipation layer comprises substantially a layer of fine-array porous heat exchange material. In some embodiment, the heat sink system also includes a fan, wherein the fan is disposed on the heat exchange apparatus to further facilitate heat dissipation. In some embodiment, the heat sink system may comprise more than one layer of fine-array porous heat exchange materials, configured such that the inner-most layer that contacts the electronic circuit has the smallest pore size and each of the other layers has an increasing pore size compared with the layer disposed therebeneath, in order to achieve an improved convection-mediated heat dissipation.
A heat radiation system for warming ambient from a heat source is also disclosed herein, which substantially comprises a heat exchange apparatus, configured to thermally contact the heat source and to dissipate heat from the heat source to the ambient. The ambient can be air, a liquid like water, or an oil. The heat radiation apparatus comprises a heat conduction layer and a heat dissipation layer, wherein the heat dissipation layer comprises substantially a layer of fine-array porous heat exchange material as disclosed above. In some embodiment, the heat radiation system may comprise more than one layer of fine-array porous heat exchange materials, configured such that the inner-most layer that contacts the heat source has the smallest pore size and each of the other layers has an increasing pore size compared with the layer disposed therebeneath, in order to achieve an improved convection-mediated heat dissipation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates conventional heat sink apparatuses having cooling fins (A) or cooling pins (B) .
FIG. 2 illustrates conventional heat sink apparatuses having designs for improved convection.
FIG. 3 illustrates a metal foam heat sink apparatus and the microstructure of the metal foam used as a heat sink material in the apparatus.
FIG. 4 illustrates a heat sink apparatus comprising a fine-array porous heat exchange material according to some embodiments of this disclosure.
FIG. 5 illustrates a heat sink apparatus comprising a double-layer fine-array porous heat dissipator.
FIG. 6 illustrates one type of heat exchanger tube comprising fine-array porous heat exchange materials according to some embodiments of this disclosure.
FIG. 7 illustrates another type of heat exchanger tube 600 comprising fine-array porous heat exchange materials according to some embodiments of this disclosure.
FIG. 8 illustrates a LED light bulb comprising a fine-array porous heat sink apparatus.
FIG. 9 illustrates a CPU heat sink system 900 comprising a fine-array porous heat exchange materials according to some embodiments of this disclosure.
FIG 10 illustrates a heat sink apparatus having fine-array porous heat exchange material according to some embodiment.
DETAILED DESCRIPTION THE DRAWINGS
A heat exchange apparatus typically transfers heat from a heat source to a medium in the ambient, such as air, water, oil or a refrigerant. Some common heat exchange apparatuses may include a heat sink, typically used to cool a device such as an LED light source and a CPU processor, a condenser, typically used in an air conditioner and refrigerator to transfer heat, and a heat radiator, typically used to radiate heat from a heat source.
FIG. 1 illustrates conventional heat sink apparatuses having cooling fins (A) , or cooling pins (B) . In a regular design, as illustrated in FIG. 1A, a conventional heat sink apparatus 100 may comprise a base 102 and an array of fins 103, wherein the base 102 is in touch with a heat source 101, the array of fins 103 is configured such that the array of fins vertically extend from the base 102 and are spaced apart with open gaps 104. By this configuration, this type of conventional heat sink apparatus 100 can effectively dissipate heat produced by the heat source 101 by conduction of and radiation from the array of fins 103, and by convection mediated by flow of air in the open gaps 104 between fins. In order to further increase the heat dissipating area of a conventional heat sink apparatus, fins are sometimes treated to have an undulating or serrated surface 105. In some variants, such as in the heat sink apparatus 110 illustrated in FIG. 1B, an array of pins 111 are used to replace the array of fins 103 in the heat sink apparatus 100 in FIG. 1A, which vertically extend from a base 112 and are spaced apart.
FIG. 2 illustrates conventional heat sink apparatuses having designs for improved convection. In one design, as illustrated in FIG. 2A, a heat sink apparatus 200 may comprise a base 202 and an array of alternately placed long and short fins 203, wherein the base 202 is in touch with a heat source 201, the array of alternately placed long and short fins 203 is configured such that the fins vertically extend from the base 202 and are spaced apart with open gaps 204. In such a configuration, the array of alternately placed long and short fins  203 substantially form a more dense array at the base end 205 and a more loose array at the open end 206, essentially allowing a favorable formation of heat gradients from the base end 205 to the open end 206. Thereby a conventional heat sink apparatus with such improved design 200 can achieve more efficient convection cooling compared with a conventional heat sink apparatus with a regular design 100 (FIG. 1A) . However, as a tradeoff, a heat sink apparatus with such a design 200 has a reduced surface area for heat dissipation mediated by conduction and radiation. In a similar design, as illustrated in FIG. 2B, a heat sink apparatus 210 may comprise an array of fins 211, wherein the array of fins 211 have a flared configuration to thereby achieve an efficient convection cooling. In yet another design, as illustrated in FIG. 2C, a heat sink apparatus 220 may comprise an array of flared pins 221 to also achieve an efficient convection cooling.
FIG. 3 illustrates a metal foam heat sink apparatus and the microstructure of the metal foam used as a heat sink material used in the apparatus. The metal foam heat sink apparatus 300 may include a heat conductive substrate 301 and a metal foam heat dissipator 302, wherein the heat conductive substrate 301 is in touch with a heat source 305, the metal foam heat dissipator 302 is disposed over and is in thermal contact with the heat conductive substrate 301, and the metal foam heat dissipator 302 substantially comprises a metal foam material. The metal foam material used in the metal foam heat dissipator 302 typically comprises an interconnected matrix of metallic ligaments 303 with varying lengths and orientations, and individual void spaces (pores) 304 of different shapes and sizes are formed between adjacent ligaments. Typical metal foams may have pore sizes of 0.5-8 mm, with a variation often higher that 100％. Compared with a conventional heat sink apparatus such as 100, 110, 200, 210 and 220 (FIGs. 1 and 2) , a metal foam heat sink apparatus 300 typically achieves better conduction/radiation-mediated heat dissipation due to the much larger relative surface area of the metal foam heat dissipator 302. However, a metal foam heat sink apparatus 300 is usually less capable of achieving efficient convection-mediated heat dissipation due to the typically irregular shapes and sizes of the void spaces (pores) 304 formed in the metal foam heat dissipator 302.
FIG. 4A illustrates a heat sink apparatus comprising a fine-array porous heat exchange material according to some embodiments of this disclosure. The heat sink apparatus 400 comprise a heat conductor 401 and a heat dissipator 402, wherein the heat conductor 401 comprises a heat conductive material, the heat dissipator 402 comprises a fine-array porous heat exchange material, and the heat dissipator 402 is configured to dispose over and thermally contact with the heat conductor 401 such that the heat conductor 401 thermally transfers heat from a heat source 405 to the heat dissipator 402 for dissipation  into the air. The heat conductive material 402 used in the heat conductor 401 may be a metal, such as Cu, Ni, Fe, Al, Au, Ag, Ti or Fe, an alloy, such as an aluminum alloy, or a copper alloy, or a heat conductive composite metal/metal oxide, such as Ti/TiO2 and Al/Al2O3. The fine-array porous heat exchange material used in the heat dissipator 402 may be made of the heat conductive material as used in the heat conductor 401 (please confirm) , and may contain highly packed and substantially uniform pores 404, as shown in a 2D view 403. The pores can have sizes of, for example, about 10 μm –1 cm, and preferably about 100 μm –1 mm, and can have a porosity of 40 -85％, preferably about 68-74％. The size of the pores in the fine-array porous heat exchange material is substantially uniform with a variation of less than about 20％and preferably of less than about 10％. In some embodiments, the fine-array porous heat exchange material can be a fine-array porous heat exchange membrane, having a thickness of 200 μm -10 cm, and preferably of 500 μm -1000 μm. The fine-array porous heat exchange material can have a surface area larger than 100 cm2, such as 20 cm × 20 cm. Compared with a conventional heat sink apparatus such as 100, 110, 200, 210 and 220 (FIGs. 1 and 2) and a metal foam heat sink apparatus 300 (FIG. 3) , a heat sink apparatus 400 as disclosed herein typically can achieve a much better conduction/radiation-mediated heat dissipation because of a much higher heat dissipating surface area due to the significantly higher surface-area-to-volume ratio of the fine-array porous heat exchange material used in the heat dissipator. It is estimated that a fine-array porous heat sink as disclosed herein can have a surface-area-to-volume ratio of 40-85％, whereas a conventional heat sink and a metal foam heat sink may have such a ratio ranging 5-15％and 15～30％, respectively. In addition, because of substantially uniform pores in the fine-array porous heat dissipator, flow of air within the pores can achieve a laminar flow, a feature substantially preventing local heat accumulation and allowing more efficient convection cooling of a fine-array porous heat sink apparatus compared with a metal foam heat sink apparatus. In some embodiment, as illustrated in FIG. 4B, a fine-array porous heat sink 410 may comprise two fine-array porous heat dissipators 412 disposed over and thermally contacting both surfaces of the heat conductor 411 to further increase the heat-dissipating surface area.
In some embodiments of the heat sink apparatus, the heat dissipator may comprise multiple layers of fine-array porous heat exchange material with different pore sizes. FIG. 5A illustrates a heat sink apparatus having a double-layer fine-array porous heat dissipator. This heat sink apparatus 500 comprises a heat conductor 501 and a heat dissipator 502, wherein the heat dissipator 502 is configured to dispose over and thermally contact the heat conductor 501 such that the heat conductor 501 thermally transfers heat from a heat source  505 to the heat dissipator 502 for dissipation into air. The heat dissipator 502 substantially comprises a first layer of fine-array porous heat exchange material 503 and a second layer of fine-array porous heat exchange material 504, configured such that the first layer of fine-array porous heat exchange material 503 has a smaller pore size and is in thermal contact with the heat conductive layer 501, and that the second layer of fine-array porous heat exchange material 504 is disposed over the first layer of fine-array porous heat exchange material 503 and has a larger pore size. In some embodiments, the ratio of pore sizes of the second layer 504 and the first layer 503 can be 2: 1 -1000: 1, and the ratio of thickness of the second layer 504 and the first layer 503 can be 0.01: 1 -1000: 1 depending on the pore sizes of the two layers. With this configuration, the double-layer fine-array porous heat sink apparatus 500, in addition to an efficient conduction/radiation-mediated heat dissipation due to the large relative surface area of the fine-array porous heat exchange material used in the heat dissipator, can achieve an improved convection-mediated heat dissipation due to the favorable establishment of a heat gradient along the direction of air flow within the pores from the first layer 503 to the second layer 504 of the heat dissipator 502. In some other embodiments, the fine-array porous heat sink apparatus may contain more than two layers of fine-array porous heat dissipator such that the first layer has the smallest pore size and is in thermal contact with the heat source, and that each of the other layers has an increasing pore size compared with the layer disposed therebeneath. In some embodiment, as illustrated in FIG 5B, a fine-array porous heat sink 510 may comprise two double-layer heat dissipators 512, disposed over and thermally contacting both surfaces of the heat conductor 511 to further increase the heat-dissipating surface area. Each of the double-layer heat dissipator 512 comprises a first layer of fine-array porous heat exchange material 513 and a second layer of fine-array porous heat exchange material 514, configured such that the first layer of fine-array porous heat exchange material 513 has a smaller pore size and is in thermal contact with the heat conductive layer 511, and that the second layer of fine-array porous heat exchange material 514 is disposed over the first layer of fine-array porous heat exchange material 513 and has a larger pore size. This configuration allows efficient heat dissipation by both increasing the heat-dissipating surface area of the heat sink apparatus 510.
The fine-array porous heat exchange materials and apparatuses disclosed above can have many practical applications.
FIG. 6 illustrates one type of heat exchanger tube 600 comprising fine-array porous heat exchange materials according to some embodiments of this disclosure, with their cross-sectional views shown. In one embodiment, as illustrated in FIG. 6A, the heat exchanger  tube 600 comprises an inner heat conduction tube 602 and an outer heat dissipation tube 603, wherein the inner heat conduction tube 602 comprises a heat conductive material, the outer heat dissipation tube 603 comprises a fine-array porous heat exchange material, and the outer heat dissipation tube 603 is disposed on and thermally contacts the outside face of the inner heat conduction tube 602 such that the inner heat conduction tube 602 transfers heat from a first medium 604 flowing through the inner heat conduction tube 602 to the outer heat dissipation tube 603 for dissipation into a second medium 605 outside the outer heat dissipation tube 603. The inner heat conduction tube 602 may have a thickness of 5 μm –10 cm, and may comprise a metal, such as Cu, Ni, Fe, Al, etc, in some embodiments, or a heat conductive ceramics, such as AlN, Al2O3 in some other embodiments. The outer heat dissipation tube 603 may have a thickness of 0.5 μm –1 cm, and the fine-array porous heat exchange material used for the outer heat dissipation tube 603 may be made of a metal, such as Cu, Ni, Fe or Al in some embodiments, or a heat conductive ceramics/polymers in some other embodiments. The fine-array porous heat exchange material used in the outer heat dissipation tube 603 has technical parameters similar to that in the fine-array porous heat sink apparatus 400 shown in FIG. 4. In some embodiments, the outer heat dissipation tube 603 may comprise more than one layer of fine-array porous heat exchange materials. In one such embodiment illustrated in FIG. 6B, the outer heat dissipator tube comprises a first layer of fine-array porous heat exchange material 613 and a second layer of fine-array porous heat exchange material 614, wherein the first layer of fine-array porous heat exchange material 613 has a smaller pore size and is disposed on the outside face of the inner heat conductor tube 612, and the second layer of fine-array porous heat exchange material 614 has a larger pore size and is disposed on the outside face of the first layer of fine-array porous heat exchange material 613. This configuration can achieve an improved convection-mediated heat dissipation in a mechanism similar to the heat sink apparatus 500 as disclosed in FIG. 5A.
FIG. 7 illustrates another type of heat exchanger tube 700 comprising fine-array porous heat exchange materials according to some embodiments of this disclosure, with cross-sectional views shown. In one embodiment, as illustrated in FIG. 7A, the heat exchanger tube 700 comprises an inner heat dissipation tube 702 and an outer heat conduction tube 703, wherein the inner heat dissipation tube 702 comprises a fine-array porous heat exchange material, the outer heat conduction tube 703 comprises a heat conductive material, and the outer heat conduction tube 703 is disposed on and thermally contacts the outside face of the inner heat dissipation tube 702 such that the outer heat conduction tube 703 transfers heat from a first medium 705 outside the outer heat  conduction tube 703 to the inner heat dissipation tube 702 for dissipation into a second medium 704 flowing through the inner heat dissipation tube 702. The outer heat conduction tube 703 may have a thickness of 5 μm –10 cm, and may comprise a metal, such as Cu, Ni, Fe, Al, etc, in some embodiments, or a heat conductive ceramics/polymers, such as AlN and Al2O3 in some other embodiments. The inner heat dissipation tube 702 may have a thickness of 0.5 μm –1 cm, and the fine-array porous heat exchange material used for the inner heat dissipation tube 702 may be made of a metal, such as Cu, Ni, Fe or Al in some embodiments, or a heat conductive ceramics/polymers in some other embodiments. The fine-array porous heat exchange materials used in the inner heat dissipation tube 702 have technical parameters similar to that in the fine-array porous heat sink apparatus 400 shown in FIG 4. In some embodiments, the inner heat dissipation tube 702 may comprise more than one layer of fine-array porous heat exchange materials. In another embodiment illustrated in FIG. 7B, the heat exchange tube 710 comprises an outer heat conduction tube 713, a first layer of fine-array porous heat exchange material 712, and a second layer of fine-array porous heat exchange material 714, wherein the first layer of fine-array porous heat exchange material 712 has a smaller pore size and is disposed on and thermally contacts the inside face of the heat conductor tube 713, the second layer of fine-array porous heat exchange material 714 has a larger pore size and is disposed on the inside face of the first layer of fine-array porous heat exchange material 712. This configuration can achieve an improved convection-mediated transfer of heat from outside medium to the inside medium, in a mechanism similar to the heat sink apparatus 500 as disclosed in FIG. 5A.
FIG. 8 illustrates a LED light bulb 800 comprising a fine-array porous heat sink apparatus, with its cross-section view of the heat sink 810 shown. The LED light bulb 800 comprises a bulb body 801 and a bulb housing 802, wherein the bulb housing 802 encloses and thermally contacts the bulb body 801. The bulb housing 802 comprising an inner heat conduction layer 812 and an outer heat dissipation layer 811, wherein the inner heat conduction layer 812 comprises a heat conductive material and the outer heat dissipation layer 811 comprises substantially a fine-array porous heat exchange material and the outer heat dissipation layer 811 is disposed on and thermally contacts the outside face of the inner heat conduction layer 812 such that the inner heat conduction layer 812 transfers heat from the LED light bulb to the outer heat dissipation layer 811 for dissipation into the air. In some embodiments, the outer heat dissipation layer 802 may comprise more than one layer of fine-array porous heat exchange materials, configured in a manner similar to the heat exchanger tube 610 disclosed in FIG. 6, in order to achieve an improved convection- mediated heat dissipation, facilitated by the favorable establishment of a heat gradient across the different layers of the fine-array porous heat exchange materials.
A heat sink comprising fine-array porous heat exchange materials may be applied in a variety of personal and cloud computing devices to provide effective and efficient cooling to electronic circuits contained therein. FIG. 9 illustrates a CPU heat sink system 900 comprising fine-array porous heat exchange materials according to some embodiments of this disclosure. In one embodiment, as illustrated in FIG. 9A, the CPU heat sink system 900 comprises a heat sink apparatus 903 and a fan 904, wherein the heat sink apparatus 903 is sandwiched between and thermally contacts a CPU chip 902, mounted on a substrate 901, and the fan 904 such that heat released from the CPU chip 902 is transferred to the heat sink apparatus 903, and is dissipated in the air facilitated by the fan 904. The heat sink apparatus 903 comprises a heat conduction layer 905, having a thickness of 1 μm -1000 μm, and a heat dissipation layer 906, having a thickness of 500 μm –10 cm, wherein the heat conduction layer 905 comprises a heat conductive material, the heat dissipation layer 906 comprises a layer of fine-array porous heat exchange material. The fine-array porous heat exchange material may have a pore size of about 10 μm –1 cm, preferably about 100 μm –1 mm, and may have a porosity of 40 -85％, preferably about 68-74％. The size of the pores in the fine-array porous heat exchange material is substantially uniform with a variation of less than about 20％and preferably of less than about 10％. In another embodiment, as illustrated in FIG. 9B, the CPU heat sink system 910 has a similar configuration with the CPU heat sink system 900, having a heat sink apparatus 913 disposed between a CPU chip 912 and a fan 914. Besides a heat conduction layer 915, the heat sink apparatus 913 also comprises a double-layer heat dissipation layer 916, wherein the double-layer heat dissipation layer 916 comprises two layers of fine-array porous heat exchange materials, with a top layer 917 contacting the fan 914 and having a larger pore size, and a bottom layer 918 contacting the heat conduction layer 915 and having a smaller pore size. In some embodiments of a CPU heat sink system, the heat dissipation layer of the heat sink apparatus may comprises more than two layers of fine-array porous heat exchange materials, having an increasing pore size across the different layers of fine-array porous heat exchange materials along the direction from the heat conduction layer-contacting surface to the fan-contacting surface. In addition to CPU heat sink systems, a heat sink comprising fine-array porous heat exchange materials may be employed to effectively cool a cloud computing device, such as cloud servers and cloud data centers.
In some embodiments, a fine-array porous heat exchange material may be used on the outer surface of fins or pins in conventional designs of heat sinks, to further increase the  heat dissipating surface area for improved heat exchange. FIG. 10 illustrates a heat sink apparatus having fine-array porous heat exchange material according to some embodiment. The heat sink apparatus 1000 has substantially a similar basic structure as in the conventional heatsink 200 as illustrated in FIG. 2A, comprising a base 1002 and an array of alternately placed long and short fins 1003, wherein the base 1002 is in thermal touch with a heat source 1001, the array of alternately placed long and short fins 1003 is configured such that the fins vertically extend from the base 1002 and are spaced apart with open gaps 1004. Similar to the heat sink 200, the array of alternately placed long and short fins 1003 in the heat sink 1000 also form a more dense array at the base end 1005 and a more loose array at the open end 1006, allowing a favorable formation of heat gradients from the base end 1005 to the open end 1006 to thereby achieve an efficient convection cooling. A unique feature of the heat sink apparatus 1000 is that each of the array of alternately placed long and short fins 1003 comprises a heat conductive fin body 1007 and a layer of fine-array porous heat exchange material 1008 disposed over and thermally contacting the heat conductive fin body 1007, allowing each of the fins 1003 to essentially form a heat sink as shown in FIG. 3. With this configuration, in addition to having a large heat-dissipating surface area, the heat sink 1000 can also achieve an efficient convection cooling both locally on each of the fins 1003, and on the whole structure of the heat sink 1000. In some embodiments, the heat sink 1000 may have another layer of fine-array porous heat exchange material, disposed on the outside of the layer of fine-array porous heat exchange material 1008 and having a larger pore size. In some other embodiments, the heat sink apparatus 1000 may comprises more than two layers of fine-array porous heat exchange materials disposed over and thermally contacting the heat conductive fin body 1007, having an increasing pore size across the different layers of fine-array porous heat exchange materials along the inner-most to the outer-most direction.
Although specific embodiments have been described above in detail, the description is merely for purposes of illustration. It should be appreciated, therefore, that many aspects described above are not intended as required or essential elements unless explicitly stated otherwise. Various modifications of, and equivalent acts corresponding to, the disclosed aspects of the exemplary embodiments, in addition to those described above, can be made by a person of ordinary skill in the art, having the benefit of the present disclosure, without departing from the spirit and scope of the disclosure defined in the following claims, the scope of which is to be accorded the broadest interpretation so as to encompass such modifications and equivalent structures.

Claims (27)

  1. A heat exchange material for use in a heat exchange apparatus, comprising a fine-array porous material, wherein:
    the fine-array porous material comprises a metal, an alloy, or a metal/metal oxide composite；
    the fine-array porous material comprises a plurality of pores, wherein the plurality of pores have a size of less than about 5000 μm；
    the size of the plurality of pores is substantially uniform with a variation of less than about 20％； and
    the fine-array porous material has a porosity of about 40-85％.
  2. The heat exchange material according to Claim 1, wherein the fine-array porous material has a porosity of about 74％.
  3. The heat exchange material according to Claim 1, wherein the fine-array porous material comprises a metal, selected from a group consisting of Ni, Al, Cu, Au, Ag, Ti, and Fe.
  4. The heat exchange material according to Claim 3, wherein the fine-array porous material comprises Cu.
  5. The heat exchange material according to Claim 1, wherein the fine-array porous material comprises an alloy, selected from a group consisting of an aluminum alloy, a copper alloy, and a nickel alloy.
  6. The heat exchange material according to Claim 5, wherein the fine-array porous material comprises an aluminum alloy.
  7. A heat exchange apparatus, comprising at least one heat dissipation layer, wherein each of the at least one heat dissipation layer comprises the heat exchange material according to Claim 1.
  8. The heat exchange apparatus of Claim 7, further comprising a heat conduction layer, wherein:
    the heat conduction layer comprises a heat conductive material；
    the heat conduction layer is disposed on and thermally contacts the at least one heat dissipation layer to thereby thermally transfer heat from a higher temperature medium in contact with the heat conduction layer to a lower temperature medium in contact with the at least one heat dissipation layer.
  9. The heat exchange apparatus of Claim 8, comprising one heat dissipation layer.
  10. The heat exchange apparatus of Claim 8, comprising two heat dissipation layers, wherein the two heat dissipation layers consists of a first heat dissipation layer and a second heat dissipation layer, wherein:
    the first heat dissipation layer is disposed on and thermally contacts with the heat conduction layer； and
    the second heat dissipation layer has a larger pore size than the first heat dissipation layer and is disposed over the first heat dissipation layer.
  11. The heat exchange apparatus of Claim 10, wherein:
    the second heat dissipation layer and the first heat dissipation layer has a pore size ratio of about 2: 1 -1000: 1；
    the second heat dissipation layer and the first heat dissipation layer has a thickness ratio of about 0.01: 1 -1000: 1, the ratio depending on pore size of the first heat dissipation layer and pore size of the second heat dissipation layer.
  12. The heat exchange apparatus of Claim 7, further comprising a heat sink main body, wherein:
    the heat sink main body comprises a base and an array of extrusions, wherein the array of extrusions are configured to extend from the base and are spaced apart with open gaps； and
    the at least one heat dissipation layer is coated on the heat sink main body.
  13. The heat exchange apparatus of Claim 12, wherein the array of extrusions are an array of fins.
  14. The heat exchange apparatus of Claim 13, wherein the array of fins comprises an array of alternately placed long and short fins.
  15. The heat exchange apparatus of Claim 13, wherein the array of fins have a flared configuration.
  16. The heat exchange apparatus of Claim 12, wherein the array of extrusions are an array of pins.
  17. The heat exchange apparatus of Claim 16, wherein the array of pins have a flared configuration.
  18. The heat exchange apparatus of Claim 8, wherein the heat conduction layer and the at least one heat dissipation layer take a form of an enclosed tube.
  19. The heat exchange apparatus of Claim 18, wherein:
    the heat conduction layer is disposed on an inside face of the heat exchange apparatus； and
    the at least one heat dissipation layer is disposed on an outside face of the heat exchange apparatus to thereby thermally transfer heat from the higher temperature medium inside the heat exchange apparatus to the lower temperature medium outside the heat exchange apparatus.
  20. The heat exchange apparatus of Claim 18, wherein:
    the heat conduction layer is disposed on an outside face of the heat exchange apparatus； and
    the at least one heat dissipation layer is disposed on an inside face of the heat exchange apparatus to thereby thermally transfer heat from the higher temperature medium outside the heat exchange apparatus to the lower temperature medium inside the heat exchange apparatus.
  21. A heat sink system for cooling a LED light source in a LED light assembly, comprising a heat exchange apparatus according to Claim 7, wherein the heat exchange apparatus provides a housing for and thermally contacts the LED light source to dissipate heat from the LED light source.
  22. A heat sink system for cooling an electronic circuit, comprising a heat exchange apparatus according to Claim 7, wherein a first side of the heat exchange apparatus thermally contacts the electronic circuit to dissipate heat from the electronic circuit.
  23. The heat sink system according to Claim 22, further comprising a fan, wherein the fan is disposed on a second side of the heat exchange apparatus to further facilitate heat dissipation.
  24. The heat sink system according to Claim 22, wherein the electronic circuit is a CPU chip.
  25. The heat sink system according to Claim 22, wherein the electronic circuit is a chip in a cloud computing device.
  26. A heat radiation system for warming ambient from a heat source, comprising a heat exchange apparatus according to Claim 7, wherein the heat exchange apparatus is configured to thermally contact the heat source and to dissipate heat from the heat source to the ambient.
  27. The heat exchange material according to Claim 1, wherein the fine-array porous material comprises a metal/metal oxide composite, selected from a group consisting of Ti/TiO2 and Al/Al2O3.
PCT/CN2015/098937 2015-12-25 2015-12-25 Heat exchange material, apparatus and system WO2017107191A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/CN2015/098937 WO2017107191A1 (en) 2015-12-25 2015-12-25 Heat exchange material, apparatus and system
CN201580081623.9A CN107835928A (en) 2015-12-25 2015-12-25 Heat exchange material, apparatus and system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2015/098937 WO2017107191A1 (en) 2015-12-25 2015-12-25 Heat exchange material, apparatus and system

Publications (1)

Publication Number Publication Date
WO2017107191A1 true WO2017107191A1 (en) 2017-06-29

Family

ID=59088754

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2015/098937 WO2017107191A1 (en) 2015-12-25 2015-12-25 Heat exchange material, apparatus and system

Country Status (2)

Country Link
CN (1) CN107835928A (en)
WO (1) WO2017107191A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108105732A (en) * 2018-01-23 2018-06-01 福建工程学院 Heat dissipation structure of LED array module
EP4075933A1 (en) * 2021-04-14 2022-10-19 Siemens Aktiengesellschaft Heat exchanger assembly

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4556784A1 (en) * 2023-11-17 2025-05-21 iiode Sàrl Light bulb

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1392762A (en) * 1971-09-07 1975-04-30 Universal Oil Prod Co Tubing or plate for heat transfer processes involving nucleate boiling
CN1053119A (en) * 1991-02-13 1991-07-17 天津大学 Metal composite mesh on two surfaces intensify heat transfer pipe and heat transfer plate
KR20070105223A (en) * 2006-04-25 2007-10-30 김병창 Heat pipe manufacturing method with foamed metal
KR20080032324A (en) * 2006-10-09 2008-04-15 정의수 Heat sink using foamed metal and its manufacturing method
KR20110132198A (en) * 2010-06-01 2011-12-07 이억기 Light emitting module and lighting device having same
CN203672209U (en) * 2014-01-21 2014-06-25 厦门大学 Miniature capillary pump ring with capillary wick structure of gradient pore structure
US20140182808A1 (en) * 2012-12-31 2014-07-03 Kookmin University lndustry Academy Cooperation Foundation Method of manufacturing porous metal foam
TWM496090U (en) * 2014-09-26 2015-02-21 Univ Chienkuo Technology LED lamp heat sink with both graphite powder and metal porous substrate structure

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1609244A (en) * 2004-09-27 2005-04-27 北京理工大学 Design and manufacturing method of metal foam structure with regular cell pattern
CN201327001Y (en) * 2008-12-27 2009-10-14 浙江工贸职业技术学院 Led light source radiator
CN103103571A (en) * 2012-11-13 2013-05-15 苏州谷力生物科技有限公司 Gold-silver alloy nano porous metal material and preparation technology thereof

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1392762A (en) * 1971-09-07 1975-04-30 Universal Oil Prod Co Tubing or plate for heat transfer processes involving nucleate boiling
CN1053119A (en) * 1991-02-13 1991-07-17 天津大学 Metal composite mesh on two surfaces intensify heat transfer pipe and heat transfer plate
KR20070105223A (en) * 2006-04-25 2007-10-30 김병창 Heat pipe manufacturing method with foamed metal
KR20080032324A (en) * 2006-10-09 2008-04-15 정의수 Heat sink using foamed metal and its manufacturing method
KR20110132198A (en) * 2010-06-01 2011-12-07 이억기 Light emitting module and lighting device having same
US20140182808A1 (en) * 2012-12-31 2014-07-03 Kookmin University lndustry Academy Cooperation Foundation Method of manufacturing porous metal foam
CN203672209U (en) * 2014-01-21 2014-06-25 厦门大学 Miniature capillary pump ring with capillary wick structure of gradient pore structure
TWM496090U (en) * 2014-09-26 2015-02-21 Univ Chienkuo Technology LED lamp heat sink with both graphite powder and metal porous substrate structure

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Derwent World Patents Index; *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108105732A (en) * 2018-01-23 2018-06-01 福建工程学院 Heat dissipation structure of LED array module
EP4075933A1 (en) * 2021-04-14 2022-10-19 Siemens Aktiengesellschaft Heat exchanger assembly

Also Published As

Publication number Publication date
CN107835928A (en) 2018-03-23

Similar Documents

Publication Publication Date Title
US6371200B1 (en) Perforated heat sink
US20120120604A1 (en) Heat dissipation device
EP3405733B1 (en) Multi-level oscillating heat pipe implementation in an electronic circuit card module
US20070090737A1 (en) Light-emitting diode assembly and method of fabrication
TW202026583A (en) Heatsink
EP3542605B1 (en) A thermal sink with an embedded heat pipe
TWI619430B (en) Heat sink
CN1902752A (en) Variable density graphite foam heat sink
WO2017107191A1 (en) Heat exchange material, apparatus and system
JP2004518269A (en) Cooling device and its manufacturing process
CN111246706A (en) Double-sided heat dissipation device
US9470459B2 (en) Support structure for heat dissipation unit
US20150168078A1 (en) Vapor Chamber Structure
US7861768B1 (en) Heat sink
US20140318744A1 (en) Thermal module
CN104677159A (en) Heat radiation substrate
US7447025B2 (en) Heat dissipation device
US20100218512A1 (en) Heat exchanger for thermoelectric applications
CN102769001A (en) Heat sink
CN100561399C (en) heat sink
TW201433252A (en) Cooling apparatus and heat sink thereof
CN111366018B (en) Heat dissipation components for semiconductor refrigeration and semiconductor refrigeration equipment
CN102480899A (en) Cooling device
TWM498303U (en) Vapor chamber
CN221962167U (en) Heat dissipation structure

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15911189

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15911189

Country of ref document: EP

Kind code of ref document: A1