EP3446059B1 - Laminated microchannel heat exchangers - Google Patents
Laminated microchannel heat exchangers Download PDFInfo
- Publication number
- EP3446059B1 EP3446059B1 EP17786489.9A EP17786489A EP3446059B1 EP 3446059 B1 EP3446059 B1 EP 3446059B1 EP 17786489 A EP17786489 A EP 17786489A EP 3446059 B1 EP3446059 B1 EP 3446059B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- sheets
- lanes
- microchannels
- thermally conductive
- heat exchanger
- Prior art date
- Legal status (The legal status 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 status listed.)
- Active
Links
- 239000012530 fluid Substances 0.000 claims description 17
- 238000009835 boiling Methods 0.000 claims description 8
- 229910052751 metal Inorganic materials 0.000 claims description 5
- 239000000919 ceramic Substances 0.000 claims description 4
- 238000004891 communication Methods 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 238000001704 evaporation Methods 0.000 claims description 2
- 238000012856 packing Methods 0.000 claims description 2
- 239000007788 liquid Substances 0.000 description 7
- 238000000034 method Methods 0.000 description 6
- 239000002826 coolant Substances 0.000 description 5
- 238000012546 transfer Methods 0.000 description 4
- 238000001816 cooling Methods 0.000 description 3
- 230000004907 flux Effects 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000000429 assembly Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- FRWYFWZENXDZMU-UHFFFAOYSA-N 2-iodoquinoline Chemical compound C1=CC=CC2=NC(I)=CC=C21 FRWYFWZENXDZMU-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000000149 argon plasma sintering Methods 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- LTPBRCUWZOMYOC-UHFFFAOYSA-N beryllium oxide Inorganic materials O=[Be] LTPBRCUWZOMYOC-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005219 brazing Methods 0.000 description 1
- 229910021387 carbon allotrope Inorganic materials 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000009760 electrical discharge machining Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000000608 laser ablation Methods 0.000 description 1
- 238000001459 lithography Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000004377 microelectronic Methods 0.000 description 1
- 238000005459 micromachining Methods 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000001259 photo etching Methods 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 230000002285 radioactive effect Effects 0.000 description 1
- 238000000110 selective laser sintering Methods 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 238000005476 soldering Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 230000005514 two-phase flow Effects 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
- 239000002918 waste heat Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
- F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
- F28D15/0233—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes the conduits having a particular shape, e.g. non-circular cross-section, annular
-
- 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
- F28F13/06—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by affecting the pattern of flow of the heat-exchange media
-
- 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
- F28F3/08—Elements constructed for building-up into stacks, e.g. capable of being taken apart for cleaning
- F28F3/086—Elements constructed for building-up into stacks, e.g. capable of being taken apart for cleaning having one or more openings therein forming tubular heat-exchange passages
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F7/00—Elements not covered by group F28F1/00, F28F3/00 or F28F5/00
- F28F7/02—Blocks traversed by passages for heat-exchange media
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
- F28D2021/0019—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for
- F28D2021/0028—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for cooling heat generating elements, e.g. for cooling electronic components or electric devices
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F2260/00—Heat exchangers or heat exchange elements having special size, e.g. microstructures
- F28F2260/02—Heat exchangers or heat exchange elements having special size, e.g. microstructures having microchannels
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F2265/00—Safety or protection arrangements; Arrangements for preventing malfunction
- F28F2265/24—Safety or protection arrangements; Arrangements for preventing malfunction for electrical insulation
Definitions
- This invention relates to microchannel-based heat exchangers, including microchannel-based evaporators used to cool heat sources with high heat fluxes such as electronic devices.
- the fluid heat exchangers dissipate heat by thermally conducting the heat into internal passages of the exchanger, through which a coolant fluid flows, absorbing the heat conducted across the walls of the exchanger, and then transporting the fluid outside the exchanger, where the heat is rejected to an external heat sink.
- the coolant fluid flowing through the exchanger may be a gas, it is generally preferable to use a liquid, as liquids have higher heat capacities and heat transfer coefficients than gases.
- the liquid may remain in a single phase, or the liquid may partially or completely evaporate within the internal passages of the exchanger.
- US9310135 discloses a heat exchanger provided by assembling a plurality of individual plates having opposed faces, wherein flow channels are machined through those opposed faces, and the plates are interconnected with intervening shim plates. End plates are connected to an assembly of such plates and intermediate plates, to form a preform, which is then machined to a desired cross section.
- the resulting structure has a plurality of passages therethrough in one direction, and a second plurality of passages therethrough in a second direction, the passages fluidly isolated from one another.
- the resulting structure is configurable to a specific geometry of a flow passage, and enables heat exchange between fluids passing through the different flow channels
- the thermally conductive sheets can further define access channel openings at each end of the lanes, which when stacked create access channels for the microchannels.
- the sheets can define a more dense packing of cross ribs in at least one inlet end of the heat exchanger to reduce the open cross-section at the inlet end of the lanes.
- the aspect ratio of the microchannels can be above 4: 1.
- the aspect ratio of the microchannels can be above 8: 1.
- the apparatus can further include thermally conductive separator sheets located between groups of the thermally conductive sheets to form a multilayer heat exchanger.
- the sheets can be made of at least one conductive metal.
- the sheets can be made of sinterable thermally conductive ceramics. The sheets can be bonded or fused.
- the microchannels can have a hydraulic diameter of below 500 microns.
- the microchannels can have a hydraulic diameter of below 200 microns.
- the base can be a base plate that is thicker than each of the sheets and the cover can include access channels in communication with the microchannels.
- the base can be thermally conductive yet electrically insulating.
- the heat exchanger can be constructed for boiling or evaporating fluid service, with the heat exchanger further including flow restrictors at the inlet ends of the microchannels.
- the flow restrictors can be formed by alternately closing an end of the first slot in a lane of slots with cross-ribs that are wider than the bulk of the cross-ribs between slots, with the alternating closed-ended lanes of slots being staggered with respect to the lanes of slots above or below, in alternating layers of slotted sheets, such that, when the sheets are stacked and bonded together, the cross-section of the parallel channels that are formed have a checkerboard pattern across the inlets of the plurality of channels, which serve as integral flow restrictors covering substantially 50% of a cross-sectional area of the main channels.
- Systems according to the invention can help to suppress Ledinegg effects and thereby allow heat exchangers to work with two-phase systems.
- microchannel evaporators according to the invention can avoid flow instabilities, due to the Ledinegg effect, whereby boiling within multiple (parallel) microchannels might otherwise be non-uniform and due to the interaction of varying pressure drop as boiling develops in the various channels, resulting in periodic backflow into the inlet header or manifold. This can help to achieve stabilized and substantially uniform boiling flows and thereby result in improved and more stable thermal performance when cooling high-flux heat sources.
- the sheet of the first type 40 includes a plurality of lines 44 of multiple slots 46, with the slots in a given line being separated by thin wall that functions as a cross-rib 48. These lines span between the common cut-out areas connected to the slots at either end of each line of slots. The common cut-out areas align with each other to form input and output manifolds when sheets are stacked.
- alternating two or more types of sheets allows the microchannels to be defined in three-dimensions.
- the laminated core structure is assembled by alternating slotted-and-ribbed sheets having the cross-ribs staggered with respect to each other when the sheets are stacked so that each line of slots forms a continuous but serpentine flow path (see also Figs. 5-7 ).
- thermally conductive un-slotted separator sheets 60 having cut-out areas 62 that align with the common cut-out areas of the slotted-and-ribbed sheets can also be used on the top and bottom of the core and/or to separate layers of microchannels.
- stacking sets of the alternating slotted-and-ribbed-sheets, flanked by un-slotted separator sheets allows the formation of a core structure that includes one or more layers each having a plurality of microchannels with interspersed cross-ribs that intermittently partially interrupt the flow path with providing lateral strengthening of the channel walls.
- the number of alternating slotted-and-ribbed-sheets in each layer, along with the sheet thickness and slot width, determines the channel depth : width aspect ratio of the channel layers.
- the layered stacked sheets are preferably bonded to ensure that all the sheets are in thermally conductive communication with each other.
- the resulting sub-assembly can then be bonded to a base plate 74 to ensure that the base plate is in thermally conductive communication with the microchannel layers, and a cover 78 can be placed and sealed on top of the resulting assembly of microchannel layers 76 bonded to the base plate, thereby forming a complete microchannel heat exchanger assembly 70.
- the input sides of the microchannels preferably include flow restrictors where the exchanger is used in boiling or evaporative service. These restrictors can be built into the laminate structure by providing extra cross-ribs 82 at the inputs of the microchannels.
- the laminated structures described above enable microchannel heat exchangers having one or more layers of microchannels with hydraulic diameters of less than 500 microns, with the microchannels having arbitrarily high depth : width aspect ratios and with thin walls.
- the channels have internal cross-ribs connecting the channel's walls, and provide mechanical strength to the channel walls and way of breaking up the fluid stream lines to improve heat transfer.
- the thermally conductive sheet and base plate materials are preferably, but not limited to, metals and their alloys; non-metallic elements, thermally conductive carbon allotropes, or thermally conductive ceramics. Bonding of the sheets can be by any convenient means that ensure high thermal conduction between the sheets and the base plate.
- microchannels are formed by inserting, between stacks of slotted-and-ribbed sheets, additional thermally conductive un-slotted separator sheets having cut-out areas that align with the common cut-out areas of the slotted-and-ribbed sheets.
- the microchannels of any layer may have the same or different depth: width aspect ratio and hydraulic diameter compared to the microchannels in the other layers.
- the depth: width aspect ratio of the resulting microchannels can be at least 2:1, and preferably between 4:1 and 15: 1.
- the walls between the resulting microchannels can be less than 200 microns and preferably between 40 and 100 microns thick.
- the base plate and microchannel walls can be fabricated from materials having thermal conductivities in excess of 100 W/m-K.
- the hydraulic diameter of the resulting microchannels can be less than 500 microns, and preferably between 50 and 200 microns.
- the liquid inlet channels can be provided with flow restrictors, to prevent backflow or two-phase flow instabilities. These inlet restrictions are provided by closing-off the inlet-side ends of the slots (e.g. by adding additional cross-ribs) of alternate sheets in the stacks of slotted-and-ribbed sheets, thereby reducing the open cross-sectional area of the inlets to the channels relative to the main channel cross-section beyond the closed portions.
- the length of the closed-off (restriction) portions of the microchannels is at least 1 mm.
- microchannel heat exchanger e.g. microchannel stacks, base plate, and over plate
- the various components of the microchannel heat exchanger can be bonded or fused, so that the exchanger is hermetically sealed (with the exception of the fluid inlet and outlet ports that communicate with the manifolds), so that the exchanger can hold elevated internal pressures. Bonding or fusing may be accomplished by any convenient means.
- microchannel heat exchanger e.g. microchannel stacks, base plate, and over plate
- the various components of the microchannel heat exchanger can also be held together by mechanical means, with suitable seals between components, so that the exchanger can hold elevated internal pressures.
- the bottom base of the layer of the microchannel exchanger is made from or is coated with a thermally conductive yet electrically insulating ceramic or dielectric solid, such as aluminum nitride, silicon carbide, beryllium oxide, diamond film, and the like.
- the microchannel exchanger then serves as the substrate for (heat generating) electronic components, which are mounted on, and in thermal contact with, the electrically insulating but thermally conductive underside surface of the exchanger.
- microchannel heat exchanger e.g. the thermally conductive base, the microchannel layers, manifolds, covers, fluid inlet and outlet ports, the slotted-and-ribbed sheets, etc.
- thermally conductive base e.g. the thermally conductive base
- microchannel layers e.g. the thermally conductive base
- manifolds e.g. the thermally conductive base
- covers e.g. the thermally conductive base
- fluid inlet and outlet ports e.g. the thermally conductive base
- slotted-and-ribbed sheets, etc. may be fabricated by any convenient means consistent with the final assembly of the heat exchangers. Such means may include, but are not limited to, the following methods and combinations thereof:
- Embodiments according to the invention can be developed for a variety of different cooling configurations and applied to a variety of different cooling tasks. For example, they can implemented in connection with the teachings of published PCT application no. WO2009/085307, filed December 26, 2008 and published US application no. US-2009-0229794, filed on November 10, 2008 .
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)
- Cooling Or The Like Of Electrical Apparatus (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
Description
- This invention relates to microchannel-based heat exchangers, including microchannel-based evaporators used to cool heat sources with high heat fluxes such as electronic devices.
- Fluid heat exchangers are used to remove waste heat from high-heat flux heat sources (typically in excess of 5 watts/cm2, and often substantially higher) by accepting and dissipating thermal energy therefrom. Examples of such high-heat flux heat sources include microelectronics, such as microprocessors and memory devices, solid-state light emitting diodes (LEDs) and lasers, insulated-gate bipolar transistor (IGBT) devices, such as power supplies, photovoltaic cells, radioactive thermal generators and fuel rods, and internal combustion engines.
- The fluid heat exchangers dissipate heat by thermally conducting the heat into internal passages of the exchanger, through which a coolant fluid flows, absorbing the heat conducted across the walls of the exchanger, and then transporting the fluid outside the exchanger, where the heat is rejected to an external heat sink. While the coolant fluid flowing through the exchanger may be a gas, it is generally preferable to use a liquid, as liquids have higher heat capacities and heat transfer coefficients than gases. The liquid may remain in a single phase, or the liquid may partially or completely evaporate within the internal passages of the exchanger.
- The flow of coolant liquid fed to the fluid heat exchanger may be driven by a pump, or by natural convection due to density differences and/or elevation between the incoming and exiting fluid (e.g. thermosyphons), or by capillary action in the internal passages of the exchanger, or by a combination of these mechanisms.
- Evaporator-type exchangers rely on the boiling mode, and have the advantages of higher heat transfer coefficients (better heat transfer) per unit of fluid flow rate of the coolant fluid. They also require much less coolant flow, as the majority of the heat is absorbed through via the latent heat of vaporization of the boiling fluid, rather than the sensible heat (heat capacity) of a single-phase liquid or gas.
- It is well known that the thermal performance and efficiency of fluid heat exchangers can be greatly enhanced if the internal passages are comprised of microchannels, i.e. channels having cross-sections with a smallest dimension of less than 1000 microns, and more typically, in the range of 50 - 500 microns.
-
US9310135 - In one general aspect, the invention features a microchannel heat exchanger according to claim 1.
- In preferred embodiments, the thermally conductive sheets can further define access channel openings at each end of the lanes, which when stacked create access channels for the microchannels. The sheets can define a more dense packing of cross ribs in at least one inlet end of the heat exchanger to reduce the open cross-section at the inlet end of the lanes. The aspect ratio of the microchannels can be above 4: 1. The aspect ratio of the microchannels can be above 8: 1. The apparatus can further include thermally conductive separator sheets located between groups of the thermally conductive sheets to form a multilayer heat exchanger. The sheets can be made of at least one conductive metal. The sheets can be made of sinterable thermally conductive ceramics. The sheets can be bonded or fused. The microchannels can have a hydraulic diameter of below 500 microns. The microchannels can have a hydraulic diameter of below 200 microns. The base can be a base plate that is thicker than each of the sheets and the cover can include access channels in communication with the microchannels. The base can be thermally conductive yet electrically insulating. The heat exchanger can be constructed for boiling or evaporating fluid service, with the heat exchanger further including flow restrictors at the inlet ends of the microchannels. The flow restrictors can be formed by alternately closing an end of the first slot in a lane of slots with cross-ribs that are wider than the bulk of the cross-ribs between slots, with the alternating closed-ended lanes of slots being staggered with respect to the lanes of slots above or below, in alternating layers of slotted sheets, such that, when the sheets are stacked and bonded together, the cross-section of the parallel channels that are formed have a checkerboard pattern across the inlets of the plurality of channels, which serve as integral flow restrictors covering substantially 50% of a cross-sectional area of the main channels.
- Systems according to the invention can help to suppress Ledinegg effects and thereby allow heat exchangers to work with two-phase systems. By providing inlet restrictions, microchannel evaporators according to the invention can avoid flow instabilities, due to the Ledinegg effect, whereby boiling within multiple (parallel) microchannels might otherwise be non-uniform and due to the interaction of varying pressure drop as boiling develops in the various channels, resulting in periodic backflow into the inlet header or manifold. This can help to achieve stabilized and substantially uniform boiling flows and thereby result in improved and more stable thermal performance when cooling high-flux heat sources.
-
-
Fig. 1 is a plan view of a first type of grooved sheet for inclusion in a grooved laminate structure that can be used to implement a microchannel heat exchanger; -
Fig. 2 is a plan view of a portion of the first type of grooved sheet ofFig. 1 shown inrectangle 2 onFig. 1 ; -
Fig. 3 is a plan view of a portion of a second type of grooved sheet for inclusion in the grooved laminate structure; -
Fig. 4 is a plan view of a separator sheet for inclusion in the grooved laminate structure; -
Fig. 5 is a perspective cutaway of the laminate structure formed by alternating first and second sheet types as shownFigs. 1-4 in an orientation shown byarrow 5 inFigs. 2 and 3 ; -
Fig. 6 is a more detailed cutaway view of the grooved laminate structure ofFig. 5 ; -
Fig. 7 is a second perspective cutaway of the laminate structure ofFig. 5 showing flow paths through the structure ofFig. 5 in an orientation shown by arrow 7 inFigs. 2 and 3 ; -
Fig. 8 is an exploded view of the laminated sheets for assembly into a grooved laminate core using the grooved laminated structure presented inFigs. 1-7 ; -
Fig. 9 is an exploded perspective view of a portion of a microchannel heat exchanger using the laminated core ofFig. 8 ; and -
Fig 10 is a cross-sectional view of the grooved laminate structure ofFig. 5 , taken through a plane that defines flow restrictors in the grooved laminate structure. - A microchannel heat exchanger can be assembled using a grooved laminated structure made up of a plurality of thermally conductive sheets. One such sheet of a
first type 40 is shown inFig. 1 . It includes common cut-outareas 42 that are separatedlines 44 ofslots 46 that define the microchannels. - More specifically, the sheet of the
first type 40 includes a plurality oflines 44 ofmultiple slots 46, with the slots in a given line being separated by thin wall that functions as across-rib 48. These lines span between the common cut-out areas connected to the slots at either end of each line of slots. The common cut-out areas align with each other to form input and output manifolds when sheets are stacked. - Referring also to
Figs. 2 and 3 , alternating two or more types of sheets allows the microchannels to be defined in three-dimensions. In particular, the laminated core structure is assembled by alternating slotted-and-ribbed sheets having the cross-ribs staggered with respect to each other when the sheets are stacked so that each line of slots forms a continuous but serpentine flow path (see alsoFigs. 5-7 ). - Referring to
Fig. 4 , thermally conductiveun-slotted separator sheets 60 having cut-outareas 62 that align with the common cut-out areas of the slotted-and-ribbed sheets can also be used on the top and bottom of the core and/or to separate layers of microchannels. - Referring to
Fig. 8 , stacking sets of the alternating slotted-and-ribbed-sheets, flanked by un-slotted separator sheets allows the formation of a core structure that includes one or more layers each having a plurality of microchannels with interspersed cross-ribs that intermittently partially interrupt the flow path with providing lateral strengthening of the channel walls. The number of alternating slotted-and-ribbed-sheets in each layer, along with the sheet thickness and slot width, determines the channel depth : width aspect ratio of the channel layers. The layered stacked sheets are preferably bonded to ensure that all the sheets are in thermally conductive communication with each other. - Referring to
Fig. 9 , the resulting sub-assembly can then be bonded to a base plate 74 to ensure that the base plate is in thermally conductive communication with the microchannel layers, and a cover 78 can be placed and sealed on top of the resulting assembly of microchannel layers 76 bonded to the base plate, thereby forming a complete microchannel heat exchanger assembly 70. - Referring to
Fig. 10 , the input sides of the microchannels preferably include flow restrictors where the exchanger is used in boiling or evaporative service. These restrictors can be built into the laminate structure by providingextra cross-ribs 82 at the inputs of the microchannels. - The laminated structures described above enable microchannel heat exchangers having one or more layers of microchannels with hydraulic diameters of less than 500 microns, with the microchannels having arbitrarily high depth : width aspect ratios and with thin walls. The channels have internal cross-ribs connecting the channel's walls, and provide mechanical strength to the channel walls and way of breaking up the fluid stream lines to improve heat transfer. The thermally conductive sheet and base plate materials are preferably, but not limited to, metals and their alloys; non-metallic elements, thermally conductive carbon allotropes, or thermally conductive ceramics. Bonding of the sheets can be by any convenient means that ensure high thermal conduction between the sheets and the base plate.
- Multiple layers of microchannels are formed by inserting, between stacks of slotted-and-ribbed sheets, additional thermally conductive un-slotted separator sheets having cut-out areas that align with the common cut-out areas of the slotted-and-ribbed sheets. The microchannels of any layer the may have the same or different depth: width aspect ratio and hydraulic diameter compared to the microchannels in the other layers.
- The depth: width aspect ratio of the resulting microchannels can be at least 2:1, and preferably between 4:1 and 15: 1. The walls between the resulting microchannels can be less than 200 microns and preferably between 40 and 100 microns thick. The base plate and microchannel walls can be fabricated from materials having thermal conductivities in excess of 100 W/m-K. The hydraulic diameter of the resulting microchannels can be less than 500 microns, and preferably between 50 and 200 microns.
- The liquid inlet channels can be provided with flow restrictors, to prevent backflow or two-phase flow instabilities. These inlet restrictions are provided by closing-off the inlet-side ends of the slots (e.g. by adding additional cross-ribs) of alternate sheets in the stacks of slotted-and-ribbed sheets, thereby reducing the open cross-sectional area of the inlets to the channels relative to the main channel cross-section beyond the closed portions. Preferably, the length of the closed-off (restriction) portions of the microchannels is at least 1 mm.
- The various components of the microchannel heat exchanger (e.g. microchannel stacks, base plate, and over plate) can be bonded or fused, so that the exchanger is hermetically sealed (with the exception of the fluid inlet and outlet ports that communicate with the manifolds), so that the exchanger can hold elevated internal pressures. Bonding or fusing may be accomplished by any convenient means.
- The various components of the microchannel heat exchanger (e.g. microchannel stacks, base plate, and over plate) can also be held together by mechanical means, with suitable seals between components, so that the exchanger can hold elevated internal pressures.
- In another embodiment, the bottom base of the layer of the microchannel exchanger is made from or is coated with a thermally conductive yet electrically insulating ceramic or dielectric solid, such as aluminum nitride, silicon carbide, beryllium oxide, diamond film, and the like. The microchannel exchanger then serves as the substrate for (heat generating) electronic components, which are mounted on, and in thermal contact with, the electrically insulating but thermally conductive underside surface of the exchanger.
- The various components of the microchannel heat exchanger, e.g. the thermally conductive base, the microchannel layers, manifolds, covers, fluid inlet and outlet ports, the slotted-and-ribbed sheets, etc. may be fabricated by any convenient means consistent with the final assembly of the heat exchangers. Such means may include, but are not limited to, the following methods and combinations thereof:
- Subtractive manufacturing techniques such as mechanical machining, milling, etching, punching, photochemical machining, laser ablation or micromachining, electrical discharge machining (EDM), ultrasonic machining, water-jet cutting, etc.
- Mechanical deformation of material, e.g. by skiving, "plowing", stamping, coining, extrusion, etc.
- Laminating and bonding of patterned sheets, to form 3-dimensonal structures with internal features and passages. The sheets may have repeating areas of the patterns, so that after bonding, the bonded assemblies may be cut or diced into individual microchannel exchangers or exchanger sub-assemblies.
- Additive manufacturing techniques (3-D printing) as selective laser sintering, direct metal laser sintering, selective laser melting, stereo-lithography, fused deposition modeling, etc.
- Bonding or fusing techniques such diffusion bonding, brazing, soldering, welding, sintering, etc.
- Mechanical assembly techniques such as bolts, studs, clamps, adhesives, and the like, using seals, as appropriate, such as gaskets, O-rings, caulks, etc.
- Embodiments according to the invention can be developed for a variety of different cooling configurations and applied to a variety of different cooling tasks. For example, they can implemented in connection with the teachings of published
PCT application no. WO2009/085307, filed December 26, 2008 and published US application no.US-2009-0229794, filed on November 10, 2008 . - The present invention has now been described in connection with a number of specific embodiments thereof. However, numerous modifications which are contemplated as falling within the scope of the present invention should now be apparent to those skilled in the art. Therefore, it is intended that the scope of the present invention be limited only by the scope of the claims appended hereto. In addition, the order of presentation of the claims should not be construed to limit the scope of any particular term in the claims.
Claims (15)
- A microchannel heat exchanger (70), comprising:a cover (78) with a first access channel and a second access channel,a thermally conductive base (74),a plurality of thermally conductive sheets (40) between the cover (78) and the base (74) that each define a series of side-by-side lanes (44) aligned with a flow direction, wherein the lanes (44) each include a plurality of aligned slots (46) that define microchannel segments that extend along the flow direction and are separated by cross ribs (48) extending across the lanes (44),wherein the sheets (40) further define common cut-out areas (42) in communication with the lanes (44) at either end of the lanes (44),wherein the sheets (40) are stacked in a direction perpendicular to the flow direction between the base (74) and cover (78) so as to cause at least some of the ribs (48) to be offset from each other along the flow direction in adjacent sheets (40) and thereby allow the microchannel segments in the same lane (44) in adjacent sheets (40) to communicate with each other along the flow direction to define a plurality of adjacent, plural-sheet microchannels in the heat exchanger (70) that each extend between the cut-out areas (42) along the flow direction, andwherein the sheets (40) are stacked between the base (74) and cover (78) so that the common cut-out areas (42) form at least one input manifold and at least one output manifold that are respectfully aligned with the first access channel and the second access channel on the cover (78).
- The apparatus of claim 1 wherein the thermally conductive sheets (40) further define access channel openings at each end of the lanes (44), which when stacked create access channels for the microchannels.
- The apparatus of claim 1 wherein the sheets (40) define a more dense packing of cross ribs (48) in at least one inlet end of the heat exchanger (70) to reduce the open cross-section at the inlet end of the lanes (44) relative to a cross-section of a portion of the lanes (44) between the inlet and outlet ends of the lanes (44).
- The apparatus of claim 1 wherein the aspect ratio of the microchannels is above 4:1.
- The apparatus of claim 1 wherein the aspect ratio of the microchannels is above 8:1.
- The apparatus of claim 1 further including thermally conductive separator sheets (60) located between groups of the thermally conductive sheets (40) to form a multilayer heat exchanger (70).
- The apparatus of claim 1 wherein the sheets (40) are made of at least one thermally conductive metal.
- The apparatus of claim 1 wherein the sheets (40) are made of sinterable thermally conductive ceramics.
- The apparatus of claim 1 wherein the sheets (40) are bonded or fused.
- The apparatus of claim 1 wherein the microchannels have a hydraulic diameter of below 500 microns.
- The apparatus of claim 1 wherein the microchannels have a hydraulic diameter of below 200 microns.
- The apparatus of claim 1 wherein the base is a base plate (74) that is thicker than each of the sheets (40).
- The apparatus of claim 1 wherein the base (74) is thermally conductive yet electrically insulating.
- The apparatus of claim 1, wherein the heat exchanger (70) is constructed for boiling or evaporating fluid service, and wherein the heat exchanger (70) further includes flow restrictors at the inlet ends of the microchannels.
- The apparatus of claim 14 wherein the flow restrictors are formed by closing an input end of every other lane (44) in each of the sheets (40) with a cross-rib (48), with the closed-ended lanes (44) of slots (46) being staggered with respect to each other in adjacent sheets (40) when the sheets (40) are stacked and bonded together to form a checkerboard pattern across the inlets of the plurality of channels.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US201662324327P | 2016-04-18 | 2016-04-18 | |
US201715402511A | 2017-01-10 | 2017-01-10 | |
PCT/US2017/028183 WO2017184635A1 (en) | 2016-04-18 | 2017-04-18 | Laminated microchannel heat exchangers |
Publications (3)
Publication Number | Publication Date |
---|---|
EP3446059A1 EP3446059A1 (en) | 2019-02-27 |
EP3446059A4 EP3446059A4 (en) | 2020-01-01 |
EP3446059B1 true EP3446059B1 (en) | 2024-06-26 |
Family
ID=60116305
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP17786489.9A Active EP3446059B1 (en) | 2016-04-18 | 2017-04-18 | Laminated microchannel heat exchangers |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP3446059B1 (en) |
KR (1) | KR102494649B1 (en) |
CN (1) | CN109416224B (en) |
IL (1) | IL263805A (en) |
WO (1) | WO2017184635A1 (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11732978B2 (en) | 2016-04-18 | 2023-08-22 | Qcip Holdings, Llc | Laminated microchannel heat exchangers |
CN113446883B (en) * | 2021-06-25 | 2022-10-25 | 西安交通大学 | Double-fluid loop staggered wave type micro-channel radiator based on elastic turbulence |
TWI827117B (en) * | 2022-06-29 | 2023-12-21 | 國立勤益科技大學 | Heat dissipator using three dimensional(3d) printed microfluidic heat sinks applied on flexible electronic device |
US20240186218A1 (en) * | 2022-10-21 | 2024-06-06 | Semiconductor Components Industries, Llc | Molded power modules with fluidic-channel cooled substrates |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2701554B1 (en) * | 1993-02-12 | 1995-05-12 | Transcal | Heat exchanger for electronic components and electro-technical equipment. |
CN1057424C (en) * | 1996-02-29 | 2000-10-11 | 中国科学院上海光学精密机械研究所 | micro-channel cooling heat sink |
FR2763204A1 (en) * | 1997-05-12 | 1998-11-13 | Ferraz | HEAT EXCHANGER FOR ELECTRONIC COMPONENTS AND ELECTROTECHNICAL APPARATUS |
US6446442B1 (en) * | 1999-10-07 | 2002-09-10 | Hydrocool Pty Limited | Heat exchanger for an electronic heat pump |
US20050189342A1 (en) * | 2004-02-23 | 2005-09-01 | Samer Kabbani | Miniature fluid-cooled heat sink with integral heater |
KR100594185B1 (en) * | 2004-12-02 | 2006-06-28 | 주식회사 이노윌 | Plate with three-dimensional microchannel and heat exchanger using the same |
JP2007127398A (en) * | 2005-10-05 | 2007-05-24 | Seiko Epson Corp | Heat exchanger, method of manufacturing heat exchanger, liquid cooling system, light source device, projector, electronic device unit, and electronic apparatus |
CN1946278A (en) * | 2005-10-05 | 2007-04-11 | 精工爱普生株式会社 | Heat exchanger, method of manufacturing heat exchanger, liquid cooling system, light source device, projector, electronic device unit, and electronic equipment |
CN100584169C (en) * | 2006-04-21 | 2010-01-20 | 富准精密工业(深圳)有限公司 | Liquid-cooled heat radiator |
US8418751B2 (en) * | 2008-05-13 | 2013-04-16 | International Business Machines Corporation | Stacked and redundant chip coolers |
US9310135B1 (en) * | 2010-05-28 | 2016-04-12 | Cool Energy, Inc. | Configureable heat exchanger |
CN201830605U (en) * | 2010-10-12 | 2011-05-11 | 讯凯国际股份有限公司 | Liquid-cooling radiator and heat exchanger thereof |
CN201897410U (en) * | 2010-12-01 | 2011-07-13 | 杭州沈氏换热器有限公司 | Micro-channel heat exchanger |
CN102003899B (en) * | 2010-12-01 | 2012-05-02 | 杭州沈氏换热器有限公司 | Microchannel heat exchanger |
JP5944104B2 (en) * | 2011-03-15 | 2016-07-05 | 株式会社東芝 | Heat exchanger |
ES2725228T3 (en) * | 2012-11-07 | 2019-09-20 | Alfa Laval Corp Ab | Plate package and method of manufacturing a plate package |
-
2017
- 2017-04-18 WO PCT/US2017/028183 patent/WO2017184635A1/en active Application Filing
- 2017-04-18 CN CN201780037866.1A patent/CN109416224B/en active Active
- 2017-04-18 KR KR1020187033234A patent/KR102494649B1/en active IP Right Grant
- 2017-04-18 EP EP17786489.9A patent/EP3446059B1/en active Active
-
2018
- 2018-12-18 IL IL263805A patent/IL263805A/en unknown
Also Published As
Publication number | Publication date |
---|---|
EP3446059A4 (en) | 2020-01-01 |
KR102494649B1 (en) | 2023-01-31 |
WO2017184635A1 (en) | 2017-10-26 |
KR20190016489A (en) | 2019-02-18 |
IL263805A (en) | 2019-03-31 |
CN109416224B (en) | 2022-05-06 |
EP3446059A1 (en) | 2019-02-27 |
CN109416224A (en) | 2019-03-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP3446058B1 (en) | Microchannel evaporators with reduced pressure drop | |
US11732978B2 (en) | Laminated microchannel heat exchangers | |
EP3446059B1 (en) | Laminated microchannel heat exchangers | |
US6935411B2 (en) | Normal-flow heat exchanger | |
US7302998B2 (en) | Normal-flow heat exchanger | |
US7836597B2 (en) | Method of fabricating high surface to volume ratio structures and their integration in microheat exchangers for liquid cooling system | |
US7278474B2 (en) | Heat exchanger | |
US20220282931A1 (en) | Heat exchanger device | |
US8561673B2 (en) | Sealed self-contained fluidic cooling device | |
US20120006383A1 (en) | Heat exchanger apparatus and methods of manufacturing cross reference | |
TW201315960A (en) | Laminated heat sinks | |
JP4721412B2 (en) | Cooler and manufacturing method thereof | |
US20180045469A1 (en) | Heat exchanger device | |
JP6162836B2 (en) | Heat exchanger | |
WO2002055942A2 (en) | Normal-flow heat exchanger | |
CN116666329A (en) | Cooling integrated gallium nitride module and preparation method thereof | |
JP2019007657A (en) | Microchannel heat exchanger | |
JP2005209874A (en) | Heatsink |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE |
|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE |
|
17P | Request for examination filed |
Effective date: 20181119 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE |
|
DAV | Request for validation of the european patent (deleted) | ||
DAX | Request for extension of the european patent (deleted) | ||
A4 | Supplementary search report drawn up and despatched |
Effective date: 20191128 |
|
RIC1 | Information provided on ipc code assigned before grant |
Ipc: B81B 1/00 20060101ALI20191122BHEP Ipc: F28D 9/00 20060101AFI20191122BHEP |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: EXAMINATION IS IN PROGRESS |
|
17Q | First examination report despatched |
Effective date: 20221221 |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: GRANT OF PATENT IS INTENDED |
|
INTG | Intention to grant announced |
Effective date: 20240119 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE PATENT HAS BEEN GRANTED |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |