JP2024500429A - Heat exchanger and heat exchanger manufacturing method - Google Patents

Abstract

Embodiments of the present application relate to heat exchangers. The heat exchanger may be an evaporator or a condenser. The heat exchanger may include a plurality of structures extending from the substrate with adjacent structures spaced apart by at least a first distance. The heat exchanger is disposed on the ends of the plurality of structures such that the at least one lid plate is spaced a second distance from the ends of the plurality of structures, the second distance being less than the first distance. The device may further include at least one lid plate having a cylindrical shape. At least one lid plate is brazed to the plurality of structures by a brazing material provided between an end of the plurality of structures and the at least one lid plate. gaps are provided between the portions of braze material such that the braze joint is formed from braze material flowing into the spacing between the at least one lid plate and the ends of the plurality of structures; The brazing material is provided in a discontinuous configuration.

Description

Embodiments of the present application relate to a heat exchanger and a method of manufacturing the heat exchanger. Some embodiments relate to heat exchangers used for two-phase cooling systems and methods of manufacturing heat exchangers.

Heat exchangers, such as evaporators and condensers, are configured to enable heat transfer within the cooling system. The overall efficiency of a cooling system depends on the efficiency of the heat transfer that occurs in the heat exchanger.

In accordance with various (but not necessarily all) embodiments of the present application, a heat exchanger is provided, the heat exchanger comprising a plurality of structures extending from a substrate and having adjacent structures spaced apart by at least a first distance. at least one lid plate disposed at an end of the plurality of structures so as to be separated from the end of the plurality of structures by a second distance smaller than the first distance; and the at least one lid plate is brazed to the plurality of structures by a brazable material provided between an end of the plurality of structures and the at least one lid plate. and brazing material is provided in a discontinuous configuration such that gaps are provided between portions of the brazing material between the at least one lid plate and the ends of the plurality of structures. A brazed joint is formed from brazing material flowing into the spacing.

The brazing material may be provided with a thickness less than the first distance.

The first distance and the second distance are selected such that Laplace pressure causes the brazing material to flow into the gap between the ends of the plurality of structures and the at least one lid plate. Good too.

The plurality of structures may extend substantially perpendicularly from the substrate.

The plurality of structures may be arranged at equal intervals on the substrate.

The plurality of structures may be arranged closer to each other at an edge of the substrate than at a center of the substrate.

The substrate may have a larger surface area than the heat source to which the heat exchanger is thermally coupled.

The heat exchanger may include a reinforcement including a plurality of protrusions configured to extend between the plurality of structures to limit flexing of the plurality of structures.

At least some of the plurality of structures extend through the at least one lid plate, and further coupling means are provided at the ends of the plurality of structures extending through the at least one lid plate. may be placed.

The plurality of structures may include fins.

The heat exchanger may include an evaporator or a condenser.

In accordance with various (but not necessarily all) embodiments of the present application, a method of manufacturing a heat exchanger is provided, the method comprising a plurality of structures extending from the substrate, the plurality of structures being at least providing a brazing material spaced apart by a first distance and overlapping at least some of the plurality of structures, the brazing material being discontinuous such that gaps are provided between portions of the brazing material. and at least one lid plate disposed at an end of the plurality of structures such that the lid plate is spaced apart from the end of the plurality of structures by a second distance that is less than the first distance. and heating the brazing material such that the brazing material flows into a space between the at least one lid plate and an end of the plurality of structures.

The brazing material may be provided with a thickness less than the first distance.

The first distance and the second distance may be selected such that Laplace pressure causes the brazing material to flow into a gap between an end of the plurality of structures and the at least one lid plate.

According to various (but not necessarily all) embodiments of the present application, a substrate, a plurality of structures extending from the substrate, and a structure between the plurality of structures to reduce bending of the plurality of structures. and at least one stiffener including a plurality of protrusions configured to extend into the heat exchanger.

The heat exchanger may include a lid plate, with the at least one reinforcement provided as part of the lid plate.

The substrate may be connected to a first end of the plurality of structures, and the at least one stiffener may be connected to a second end of the plurality of structures.

Side surfaces of the plurality of protrusions of the reinforcing material may be brazed to side surfaces of the plurality of structures.

The protrusion of the reinforcement may be coupled to all of the plurality of structures.

The protrusion of the reinforcement may be coupled to a portion of the plurality of structures.

Various (but not necessarily all) embodiments of the present application include a substrate and a plurality of structures extending from the substrate, the flow of a working fluid being directed toward a center of the substrate rather than an edge of the substrate. A heat exchanger can be provided that is configured to provide a larger flow path for flow.

The plurality of structures may be arranged closer to each other at an edge of the substrate than at a center of the substrate.

The heat exchanger may include an inlet portion having a larger passage width at the center of the substrate than at the edges of the substrate.

The substrate may have a larger surface area than the heat source to which the heat exchanger is thermally coupled.

According to various (but not necessarily all) embodiments of the present application, the structure includes a substrate, a plurality of structures extending from the substrate, and a lid plate, and at least some of the plurality of structures extend from the lid. Extending through the plate, the coupling means may provide a heat exchanger provided at the end of the structure extending through the lid plate.

According to various (but not necessarily all) embodiments of the present application, a two-phase cooling system can be provided that includes one or more heat exchangers as described herein.

Some embodiments will be described below with reference to the accompanying drawings.
1 is a schematic diagram illustrating a passive two-phase cooling system according to an embodiment. FIG. It is a schematic diagram showing a part of evaporator concerning an example. It is a schematic diagram showing a part of evaporator concerning an example. FIG. 2 is a schematic diagram showing a manufactured evaporator according to an example. FIG. 2 is a schematic diagram showing a manufactured evaporator according to an example. FIG. 2 is a schematic diagram showing a method according to an example. FIG. 3 is a schematic diagram showing an alternative structure of a brazing material according to an example. FIG. 3 is a schematic diagram showing an alternative structure of a brazing material according to an example. FIG. 3 is a schematic diagram showing an alternative structure of a brazing material according to an example. FIG. 3 is a schematic diagram showing an alternative structure of a brazing material according to an example. FIG. 2 is a schematic diagram showing a manufactured evaporator according to an example. FIG. 2 is a schematic diagram showing an evaporator according to an example. FIG. 2 is a schematic diagram showing an evaporator according to an example. FIG. 2 is a schematic diagram showing an evaporator according to an example. 1 is a schematic diagram and a schematic diagram showing main components of a passive two-phase cooling system according to an embodiment; FIG.

FIG. 1 is a schematic diagram illustrating a two-phase cooling system 101 including heat exchangers such as an evaporator 103 and a condenser 105 according to an embodiment of the present application.

In the embodiment of FIG. 1, the two-phase cooling system 101 includes a passive two-phase cooling system driven by gravity rather than pumps and requires external work input to drive flow. In the embodiment of FIG. 1, the passive two-phase cooling system 101 includes a thermosyphon loop. The heat exchanger may be provided in other types of two-phase cooling systems such as heat tubes or steam chambers.

The thermosyphon loop shown in FIG. 1 includes an evaporator 103, a condenser 105, a downcomer 107, and a riser 109. A working fluid 113 is provided within the thermosyphon loop. During use of the thermosyphon loop, the working fluid 113 circulates within the components of the thermosyphon loop.

The evaporator 103 is provided at the bottom of the thermosyphon loop so that the working fluid flows through the downcomer pipe 107 and into the evaporator 103 under the force of gravity as shown by arrow 115. The height and inner diameter of the downcomer pipe 107 are selectable such that the static end of the fluid in the downcomer pipe 107 directs fluid through the evaporator 103, the riser pipe 109, and the condenser 105. . The working fluid 113 is normally in a liquid phase 117 when within the downcomer 107 . In particular, the volume of the downcomer pipe 107 filled by the working fluid 113 in liquid phase 117 is based on the operating conditions and geometry of the thermosyphon.

The evaporator 103 includes any means for transferring heat from the heat source 111 to the working fluid 113. The evaporator 103 is thermally coupled to the heat source 111. A thermal interface material may be used to allow the evaporator 103 to be thermally coupled to the heat source 111. The heat source 111 may include an electronic device that generates unnecessary heat during operation. The electronic device may be a server, router, network switch, storage device, or any other suitable type of device. In some embodiments, these heat sources may include a data center, a communications equipment room, or multiple electronic equipment that may provide a network, communications room, computer room, network room, or any other suitable arrangement. good.

In other embodiments, the heat source 111 may be an intermediate fluid, so that heat is exchanged between two working fluids (intermediate fluid and working fluid 113). In these embodiments, the evaporator 103 is a heat exchanger with metal walls separating the two streams. The wall may be made of ceramic or other materials.

As shown by arrow 119, heat is transferred from the heat source 111 to the working fluid 113 in the evaporator 103. This heat transfer causes evaporation of a portion of the working fluid 113 within the evaporator 103, converting the working fluid 113 from a liquid phase 117 to a mixture of liquid and vapor phases. In particular, the evaporator 103 converts a portion of the working fluid 113 into a vapor phase 121 while leaving a portion of the working fluid 113 in a liquid phase 117, so that the fluid discharged from the outlet of the evaporator 103 has a vapor dryness level. is a two-phase mixture for which . The two-phase mixture may include droplets of vapor entrained within a liquid or other fluid state, depending on the thermosyphon loop design, heat load, heat removal conditions, fill factor, and other suitable parameters. But that's fine.

The evaporator 103 is coupled to the riser pipe 109 such that the working fluid discharged from the evaporator 103 flows into the riser pipe 109 . As shown by arrow 123, the working fluid includes a two-phase mixture in which the vapor phase 121 is less dense than the liquid phase 117. Passive flow in the thermosyphon loop is driven by the density difference between the working fluid 113 in liquid phase in the downcomer pipe 107 and the working fluid 113 in a two-phase mixture in the riser pipe 109 .

The evaporator 103 may include a structure that enables efficient heat transfer from the evaporator 103 to the working fluid 113. For example, the evaporator 103 may include a wick structure, microchannels, an array of fins, a serpentine arrangement of macro/microchannels, or any suitable combination of these features. 2, 3, and 6 to 8 show embodiments of the evaporator 103 including such a structure.

The condenser 105 is provided at the top of the thermosyphon loop. The condenser 105 is connected to the evaporator 103 such that the working fluid 113 flows downwardly (by gravity 115) from the condenser 105 to the evaporator 103 and upwardly from the evaporator 103 to the condenser 105. placed on top of.

The condenser 105 is coupled to the riser 109 such that the working fluid 113 in the two-phase mixture (vapor phase 121 and liquid phase 117) flows from the riser 109 into the condenser 105. The condenser 105 may include any means for cooling the working fluid 113. For example, the condenser 105 may be air-cooled or liquid-cooled. Liquid cooled condenser 105 may include a tube-in-tube configuration, a shell-and-tube configuration, a plate heat exchanger, or any other suitable configuration or arrangement. The air-cooled condenser 105 may include a louver-fin flat tube heat exchanger, a tube-and-fin heat exchanger, or any other suitable type of heat exchanger configuration or arrangement.

The condenser 105 is thermally coupled to a coolant 125. A thermal interface material may be used to allow the condenser 105 to be thermally coupled to the coolant 125. In other embodiments, the coolant 125 may be integrated directly into the condenser 105 with a wall interface that separates the flow of working fluid 113 from the flow of coolant 125. The wall interface may include a highly conductive metal or metal alloy such as copper, aluminum, brass, or any other suitable metal. In some embodiments, the wall interface may include a highly conductive ceramic, such as aluminum nitride (AlN), or a polymer, such as a filled polymer composite.

As shown by arrow 127, the condenser 105 allows heat transfer from the working fluid 113 to the coolant 125. This heat transfer causes the working fluid 113 to at least partially condense and return to the liquid phase 117. The working fluid 113 at the outlet of the condenser 105 may be a liquid phase 117 or a two-phase mixture (vapor phase 121 and liquid phase 117).

The condenser 105 is coupled to the downcomer 107 such that the working fluid 113 flows down the downcomer 107 by gravity and is returned to the inlet of the evaporator 103.

2A and 2B illustrate a portion of a heat exchanger 200 that may be used in the two-phase cooling system 101 of FIG. 1 or any other suitable cooling system. The heat exchanger 200 may be the evaporator 103 or the condenser 105, or any other suitable type of heat exchanger. The heat exchanger 200 may be a macroscale or microscale two-phase heat exchanger. The heat exchanger 200 may be a single-phase heat exchanger or a two-phase heat exchanger 200, or any other suitable type of heat exchanger 200.

The exemplary heat exchanger 200 includes a substrate 201, a plurality of structures 203, and at least one cover plate 205. To achieve a more robust design, the heat exchanger 200 includes a mechanical bond between the top of the structure 203 and the lid plate 205. Components of the heat exchanger 200 are not shown to scale in FIGS. 2A and 2B. FIG. 2A shows the heat exchanger 200 before the brazing material 207 is melted, and FIG. 2B shows the heat exchanger 200 after the brazing material 207 has melted. 2A and 2B only show a portion of the heat exchanger 200, so only two structures 203 are shown. It should be appreciated that the plurality of structures 203 are configured to provide a plurality of flow paths for working fluid through the heat exchanger 200.

The substrate 201 includes a flat or substantially flat surface. The substrate 201 may include a thermally conductive material. When the heat exchanger 200 is used as the evaporator 103, the substrate 201 is thermally coupled to a heat source to enable heat transfer from the heat source to the working fluid in the evaporator 103. Good too.

The plurality of structures 203 extend from the surface of the substrate 201. The structure 203 can be obtained by machining, brazing, extrusion, additive manufacturing, or other suitable manufacturing techniques or combinations of manufacturing techniques. At least some of the structures 203 define a flow path for working fluid through the heat exchanger 200. In other embodiments, the heat exchanger 200 may include a plurality of different types of structures 203, such as fins, plates, or any other suitable structure.

In the embodiment of FIGS. 2A and 2B, the structure 203 includes an elongated structure extending perpendicularly or substantially perpendicularly from the substrate 201. In the embodiment of FIGS. In the embodiment of FIGS. 2A and 2B, the structure 203 has a rectangular cross section. Other shapes of the structure 203 are provided by other embodiments of the present application.

In the embodiment of FIGS. 2A and 2B, two adjacent structures 203 are separated by a first distance w. The first distance determines the channel width between the structures 203. In some embodiments, the heat exchanger 200 may be configured such that the plurality of structures 203 are equally spaced across the substrate 201. In such an example, different channels between different adjacent structures 203 have the same width. In other embodiments, the heat exchanger 200 may be configured such that the plurality of structures 203 are equally spaced across the substrate 201. For example, the structures 203 may be spaced more apart in areas of the substrate 201 that are closer to the heat source. Thereby, a larger flow path and more fluid flow can be provided in a region of the heat exchanger 200 where the heat load is high. For example, the plurality of structures 203 may be arranged at closer intervals at the ends of the substrate 201 than at the center of the substrate 201.

In some embodiments, the footprint of the substrate 201 may be larger than the area of the heat source to improve heat dissipation. In such embodiments, the evaporator 103 having non-uniform channel widths may advantageously provide a uniform or substantially uniform flow distribution in all channels of the evaporator 103; This improves thermal performance.

The structure 203 may include any suitable thermally conductive material. The structure 203 may include the same material as the substrate 201 and the cover plate 205. In other embodiments, the substrate 201 and the structure 203 may include different materials than those used for the lid plate 205.

The cover plate 205 is disposed to cover the ends of the plurality of structures 203. The lid plate 205 is provided at the opposite end of the structure 203 with respect to the substrate 201 to form a closed volume for circulation of the working fluid 113.

The lid plate 205 includes a flat or substantially flat surface. In the embodiment of FIGS. 2A and 2B, only a portion of the lid plate 205 is shown. It should be understood that the lid plate 205 may cover all of the plurality of structures 203 or other structures.

The cover plate 205 is brazed to the plurality of structures 203 using the brazing material 207. The brazing material 207 is provided between the ends of the plurality of structures 203 and the lid plate 205. The braze material 207 may include any suitable material that can be melted and hardened to form a rigid connection between the end of the structure 203 and the lid plate 205. In some embodiments, the heat exchanger 200 can be further strengthened by brazing the four outer surfaces of the lid plate 205 to the top of the substrate 201.

FIG. 2A shows the heat exchanger 200 before the brazing material 207 is melted and before the rigid connections are formed. The cover plate 205 is spaced apart from the ends of the plurality of structures 203 by a second distance d. The second distance d is smaller than the first distance w that determines the gap between adjacent structures 203.

In this case, the brazing material also has a thickness d equal to the distance between the end of the structure 203 and the lid plate 205. Therefore, the thickness of the brazing material is also smaller than the spacing between adjacent structures 203.

The brazing material 207 may be provided in a discontinuous configuration. The braze material 207, instead of being provided in a continuous sheet, is discontinuous so that there are gaps provided between portions of the braze material 207. For example, the braze material 207 may be provided as a network of lines or intersecting lines, or in any other suitable configuration. In the embodiment shown in FIG. 2A, the discontinuity extends into the page.

FIG. 2B shows the heat exchanger 200 after the brazing material 207 has been melted and formed into a rigid joint between the end of the structure 203 and the lid plate 205. When the brazing material 207 melts, it flows between the end of the structure 203 and the lid plate 205, thereby cooling the heat exchanger 200 again and forming a rigid joint from the solidified brazing material 207. It is formed.

In some embodiments of the present application, the discontinuous configuration of the brazing material 207 allows the molten brazing material 207 to fill the spaces between the lid plate 205 and the ends of the plurality of structures 203. Flow into. Brazing material 207 flows horizontally across the ends of the plurality of structures 203 rather than flowing downward into channels between adjacent structures 203. In the example shown in FIGS. 2A and 2B, molten braze material 207 flows into the page to form a braze joint, as shown in FIG. 2B.

In some embodiments of the present application, the brazing material 207 flows horizontally across the ends of the plurality of structures 203 rather than flowing downwardly into channels between the adjacent structures 203. This means that the volume of the channel for the flow of the working fluid 113 is maintained and not reduced by the unnecessary brazing material 207 flowing into the channel. This is advantageous for the heat exchanger 200 to function efficiently.

The spacing d between the end of the structure 203 and the lid plate 205 and the channel width w between the adjacent channels may be selected to control the Laplace pressure. The Laplace pressure prevents the brazing material 207 from flowing downward into the flow path between the adjacent structures 203 and between the ends of the plurality of structures 203 and at least one of the lid plates 205. flows horizontally into the gap between. The brazing material 207 may wick and flow through the gap between the end of the structure 203 and the lid plate 205. The width w of the flow path is larger than the distance d between the end of the structure 203 and the lid plate and the corresponding thickness of the unmelted brazing material 207. Since the Laplace pressure is inversely proportional to the thickness of the braze material 207, when the braze material 207 melts, it creates a greater pressure difference in the horizontal direction than in the downward direction, so that it flows horizontally.

3A-3B illustrate an example of a manufactured heat exchanger 200. In this embodiment, the heat exchanger 200 is the evaporator 103, and the plurality of structures 203 include the plurality of evaporator fins 305. Other types of heat exchangers 200, including other types of structures 203, may be manufactured using similar processes in variations of the present application.

FIG. 3A shows the braze material 207 provided at the ends of the plurality of evaporator fins 305. FIG. 3B shows a cross section of a portion of the evaporator 103 before the brazing material 207 is melted.

FIG. 3A shows the substrate 201 and a plurality of evaporator fins 305 extending from the substrate 201. The lid plate 205 is not shown in FIG. 3A.

In the embodiment of FIG. 3A, the substrate 201 is a square or substantially square plate. Other shapes of substrate 201 may be used in some embodiments of the present application.

The plurality of evaporator fins 305 extend perpendicularly or substantially perpendicularly from the substrate 201. In the embodiment of FIG. 3A, both of the evaporator fins 305 include thin plates. The thickness of this plate is several orders of magnitude smaller than the longest length of the plate (along the flow direction). The plates of the evaporator fins 305 are provided in a parallel or substantially parallel arrangement across the surface of the substrate 201. Other dimensions and shapes of the plates of the evaporator fins 305 that define the flow paths may be used depending on the application and operating conditions.

Adjacent evaporator fins 305 are separated from each other by a first distance w. In the embodiment of FIG. 3A, the evaporator fins 305 are equally spaced across the surface of the substrate 201 such that each of the evaporator fins 305 is spaced the same first distance w from an adjacent evaporator fin 305. Placed. This forms a plurality of parallel or substantially parallel channels across the surface of the substrate 201, the channels having a width w.

The brazing material 207 is provided on the ends of the evaporator fins 305. In the embodiment of FIG. 3A, the braze material 207 is provided in a plurality of wires 301. The wiring 301 extends across the ends of the evaporator fins 305. In the embodiment of FIG. 3A, the wiring 301 extends in a direction perpendicular or substantially perpendicular to the direction of the flow path formed by the evaporator fins 305.

The wirings 301 of the brazing material 207 are provided in a discontinuous configuration so that gaps are provided between the wirings 301. The gap at the top of the evaporator fins 305 provides a space for the brazing material 207 to flow when it melts, thereby ensuring effective adhesion between the evaporator fins 305 and the lid plate 205. guaranteed. In the embodiment shown in FIG. 3A, the traces 301 of the brazing material 207 are arranged at the same spacing at the ends of the evaporator fins 305. In the embodiment shown in FIG. In other embodiments of the present application, other arrangements of the wiring 301 may be used.

The wiring 301 of the brazing material 207 has a thickness d that is smaller than the width between adjacent evaporator fins 305 .

FIG. 3B shows a cross section of a portion of the evaporator 103 before the brazing material 207 is melted. FIG. 3B shows one end of the evaporator fin 305 and the wiring 301 of the brazing material 207 provided between the end of the evaporator fin 305 and the lid plate 205.

The cover plate 205 is provided on the wiring 301 of the brazing material 207. Due to the thickness of the wiring 301 of the brazing material 207, the lid plate 205 is spaced from the end of the evaporator fin 305 by a distance d. In the embodiment shown in FIG. 3B, the interconnect 301 has a circular or substantially circular cross section. In other embodiments of the present application, other shapes of wiring may be used.

When the brazing material 207 melts, Laplace pressure causes the brazing material to flow horizontally between the lid plate 205 and the ends of the evaporator fins 305, as shown by arrow 303 in FIG. 3B. . This direction of flow allows a strong braze joint to be formed and prevents excess braze material from flowing into the channel formed by the evaporator fins 305.

FIG. 4 shows an example of a method used to manufacture a heat exchanger 200 according to some embodiments of the present application. The heat exchanger 200 may be a macroscale or microscale two-phase heat exchanger. The heat exchanger 200 may be used for a two-phase cooling system 101. The heat exchanger 200 may be the evaporator 103 or the condenser 105, or any other suitable type of heat exchanger 200.

At block 401, the method includes providing a plurality of structures 203 extending from a substrate 201 where the structures 203 are separated by at least a first distance w. The structure 203 may include any means for defining a flow path for working fluid 113 through the heat exchanger 200. In some examples, the plurality of structures 203 may include a plurality of evaporator fins 305 as shown in FIG. 3A, or may be of any other suitable type or configuration.

At block 403, the method includes providing brazing material 207 overlying at least a portion of the structure 203. The brazing material 207 may be provided in a discontinuous configuration such that gaps are provided between portions of the brazing material 207. The brazing material 207 may be provided in a plurality of wires 301 as shown in FIG. 3A, or in other suitable configurations. The brazing material 207 is provided with a thickness d smaller than the first distance w between the adjacent structures 203.

At block 405, the method includes providing at least one lid plate 205 on an end of the plurality of structures 203. The at least one lid plate 205 is also provided on the brazing material 207 such that the brazing material 207 is located between the end of the structure 203 and the lid plate 205. The cover plate is spaced apart from the ends of the plurality of structures 203 by a second distance d, and the second distance is smaller than the first distance w.

At block 407, the method further includes heating the braze material 207. The brazing material 207 is heated above its melting point so that the molten brazing material 207 flows into the spacing between the lid plate 205 and the ends of the plurality of structures 203.

The distance w between the adjacent structures 203 and the thickness d of the brazing material 207 are such that when the brazing material 207 is melted, the brazing material 207 is attached to the plurality of structures 203 by Laplace pressure. It is selected to flow into the gap between the end and said at least one lid plate 205. This can prevent the brazing material 207 from flowing into the flow path formed by the structure 203. This is advantageous in maximizing or substantially maximizing the effective heat transfer area and reducing the total pressure drop within the heat exchanger 200.

In the above embodiment, the brazing material 207 is provided with a thickness d that is less than the first distance w between the adjacent structures 203. In other embodiments, the brazing material 207 may be provided with an initial thickness d greater than the first distance w between the adjacent structures 203. In such embodiments, when the brazing material 207 is heated, the initial Laplace pressure causes the molten brazing material 207 to initially flow into the gaps between the adjacent structures 203. Become. However, once the brazing material 207 flows to a position where the thickness becomes smaller than the first distance w between adjacent structures 203, the flow of the brazing material 207 is caused by the Laplace pressure. toward the gap between the end of the structure 203 and the cover plate 205. Flow into the gap between adjacent structures 203 is stopped and reversed to maximize or substantially maximize the effective heat transfer area and reduce the total pressure drop within the heat exchanger 200. Ru. In such a case, the Laplace pressure difference between the meniscus in the gap between adjacent structures 203 and the ends of the structures 203 and lid plate 205 drives the flow of the brazing material 207.

5A-5D illustrate variations of braze material 207 that may be used in embodiments of the present application. In these embodiments, the braze material 207 is provided in a discontinuous configuration rather than a continuous sheet. The discontinuous configuration ensures that there are gaps between portions of the brazing material 207. These gaps provide a spacing between the lid plate 205 and the end of the structure 203 through which molten brazing material 207 can flow.

The thickness of the brazing material 207 may be selected such that the Laplace pressure of the brazing material 207 causes a flow of the brazing material 207 in a horizontal direction across the ends of the structure 203. The area covered by the brazing material 207 and the discontinuous configuration used for the brazing material 207 are such that a sufficient volume of the brazing material 207 is provided so that a secure and rigid joint is formed. may be selected.

In the embodiment of FIG. 5A, the brazing material 207 is provided in the plurality of wires 301. The plurality of wires 301 may have a circular or substantially circular cross section. The plurality of wirings 301 may extend perpendicularly to the channel formed by the plurality of structures 203. In the embodiment of FIG. 5A, the interconnects 301 are spaced uniformly across the top of the structure 203. The number and spacing of the wires 301 may be selected to control the amount of brazing material 207 used.

In the embodiment of FIG. 5B, the braze material 207 is provided in a plurality of dots 501. The dots 501 are provided in an interconnection network 503. The interconnection network 503 has gaps 505 between the dots 501 into which the molten brazing material 207 can flow. The number and size of the dots 501 may be selected to control the amount of brazing material 207 used.

The brazing material 207 shown in FIG. 5C is also provided in the interconnect network 503. In this embodiment, the interconnection network 503 includes a plurality of circular gaps 505. The circular gap 505 provides a space through which the molten brazing material 207 can flow. In other embodiments of the present application, other shapes for the gap 505 may be used. The number of gaps 505 and the size of gaps 505 may be selected to control the amount of brazing material 207 used.

FIG. 5D shows another embodiment of an interconnect network 503 of brazing material 207. In this embodiment, the interconnection network 503 may be formed from a plurality of intersecting wires 301. In this embodiment, the interconnection network 503 provides a plurality of rectangular gaps 505 into which the molten brazing material 207 flows. The number of wires 301 in the interconnect network 503 may be selected to control the amount of brazing material 207 used.

In the embodiment shown in FIGS. 4-5D, the substrate 201 has a substantially square shape. Other shapes may be used in other embodiments. In some embodiments, the substrate 201 may have a larger surface area than the heat source to which the substrate 201 and the evaporator 103 are thermally coupled. This is advantageous in distributing heat across the substrate 201 and can provide better thermal performance.

In some embodiments, the heat exchanger 200 may include additional components not shown in FIGS. 2-5D. In some embodiments, the heat exchanger 200 may include stiffeners configured to limit flexing of the structure 203. The stiffener may include a plurality of protrusions extending between the plurality of structures 203 to hold the structures 203 in place.

In some embodiments, the heat exchanger 200 may be configured such that at least a portion of the structure 203 extends through the lid plate 205. Thereby, a larger surface may be provided for the brazing between the structure 203 and the lid plate 205. Further coupling means may be provided at the end of the structure 203 extending through the lid plate 205. Further connection means may provide other connections of the structure 203 to the lid plate 205 in addition to the brazed connection. This may provide a more rigid heat exchanger 200 and may enable said heat exchanger 200 to withstand high internal operating pressures.

FIG. 6 shows an example of a heat exchanger 200 including a reinforcement 601 being manufactured. In this embodiment, the heat exchanger 200 is an evaporator 103 having a plurality of structures 203. The reinforcement 601 is configured to strengthen the heat exchanger 200 and reduce deformation of the heat exchanger 200 during use. The reinforcement 601 may be provided in a heat exchanger 200 as shown in FIGS. 2-5D and 7A-8, or any other suitable type of heat exchanger 200.

The heat exchanger 200 shown in FIG. 6 includes a substrate 201 and the plurality of structures 203 described above.

The reinforcing structure 601 may be provided as part of the lid plate 205 or as an additional component between the end of the structure 203 and the lid plate 205. In the embodiment shown in FIG. 6, the substrate 201 is connected to a first end of the plurality of structures 203, and the reinforcing structure 601 is connected to a second end of the plurality of structures 203.

The reinforcing structure 601 includes a plurality of protrusions 603 extending between the plurality of structures 203 to hold the structures 203 in place. The protrusion 603 may be configured to punch an end of the structure 203 in a predetermined position. The protrusions 603 have a much shorter length than the structures 203 so that the protrusions 603 do not protrude too much into the channels formed by adjacent structures 203. This is advantageous in maintaining the size of the passages so that sufficient working fluid 113 flows through said passages when heat exchanger 200 is in use.

In the embodiment of FIG. 6, the protrusion 603 of the reinforcing structure 601 is formed in an intertwined structure with the end of the structure 203. The protrusion 603 is sized and shaped to fit tightly into the gap between the ends of the structure 203. The protrusion 603 grips the side surface of the structure 203 and holds the structure 203 in a predetermined position. In some embodiments, the plurality of protrusions 603 of the reinforcing structure 601 may be brazed to the sides of the plurality of structures 203. This is advantageous in preventing movement of the structure 203 with respect to the reinforcing structure 601, thereby avoiding deformation of the heat exchanger 200.

In the embodiment of FIG. 6, both of the structures 203 are coupled to the protrusions 603 of the reinforcement 601. In other embodiments, the protrusion 603 of the reinforcing structure 601 may be coupled to a portion of the plurality of structures 203. If the protrusion 603 is coupled to only a portion of the plurality of structures 203, the portion may be selected to reduce deformation of the heat exchanger 200. For example, since the structure 203 at the center of the heat exchanger 200 is the one most likely to deform during use, the protrusion 603 203.

In the embodiment of FIG. 6, the stiffener 601 is provided as a single component that is coupled to all the structures 203. Different arrangements for the reinforcement 601 are provided in other embodiments. For example, different reinforcements 601 may be coupled to different parts of the structure 203.

7A and 7B show examples of various shapes that may be used for the heat exchanger 200. 7A and 7B show a manufactured heat exchanger 200. In these embodiments, the heat exchanger 200 is an evaporator 103 having a plurality of structures 203. The heat exchanger 200 may be manufactured using any of the methods described above. These heat exchangers 200 are configured to provide uniform or substantially uniform flow of working fluid 113 across the heat exchangers 200 to improve thermal performance. The features shown in FIGS. 7A and 7B may be provided in combination with other features of the heat exchanger 200 of any of FIGS. 2-6 or 8.

In the embodiment of FIGS. 7A and 7B, the heat exchanger 200 includes the substrate 201 and a plurality of structures 203 extending from the substrate 201. In the embodiment of FIGS. A cover plate 205 is provided on the structure 203 . In the embodiment of FIGS. 7A and 7B, the heat exchanger 200 is configured to provide a larger flow path for the working fluid 113 to flow toward the center of the substrate 201 than the edges of the substrate 201. Ru. This is advantageous in providing a uniform flow distribution of the working fluid.

The substrate 201 is thermally coupled to a heat source 701. A thermal interface material may be provided between the heat source 701 and the substrate 201 for thermal coupling. In the embodiment of FIGS. 7A and 7B, the substrate 201 is larger than the heat source 701. Enlarging the substrate 201 is advantageous in improving heat diffusion, increasing the effective heat transfer area, and reducing the thermal resistance of the heat exchanger 200.

In the embodiment of FIGS. 7A and 7B, the heat source 701 is located at the center of the substrate 201. The flow paths defined by the structure 203 have different widths to provide a uniform or substantially uniform flow distribution throughout the heat exchanger 200. Channels closer to the heat source 701 have a larger size than channels farther away. The width of the flow paths used may be designed to achieve a uniform or substantially uniform flow distribution while maintaining the mechanical integrity of the heat exchanger 200.

In the embodiment of FIG. 7A, different channel sizes are obtained by varying the spacing between the structures 203. The spacing between adjacent structures 203 is larger at the center of the substrate 201 than at the edges of the substrate 201. The structures 203 are arranged closer to each other at the edges of the substrate 201 than at the center of the substrate 201. Accordingly, a channel having a larger width is formed at the center of the substrate 201, and a channel having a narrower width is formed at the edge of the substrate 201.

In the embodiment of FIG. 7B, different channel sizes are obtained by installing an inlet section 703 that provides a larger channel width in the center of the substrate 201 compared to the edges of the substrate 201. The inlet portion 703 may be directly machined on the cover plate 205.

In this embodiment, the inlet section 703 defines an inlet of the heat exchanger 200. The inlet section 703 shown in FIG. 7B has two different lengths. A first length is provided toward the center of the substrate 201, and a second length is provided toward the edge of the substrate 201. Since the first length is shorter than the second length, the inlet is larger at the center of the substrate 201 than at the edges. It should be understood that other configurations of the inlet portion 703 may be used in other embodiments of the present application.

In both of the embodiments shown in FIGS. 7A and 7B, the heat exchanger 200 is provided in two parts. In these embodiments, the lid plate 205 includes a central portion 705 that divides the heat exchanger 200 into different parts.

The lid plate 205 may be bonded to the substrate 201 and the structure 203 by brazing joints 707. In the embodiment shown in FIGS. 7A and 7B, the braze joint 707 may be formed along the edge of the structure 203 at the edge of the substrate 201. The brazing joint 707 is also formed between the central part 705 of the lid plate 205 and the structure 203 adjacent to the central part 705. Such an arrangement of the brazed joints 707 is advantageous in providing better adhesion between the substrate 201 and the lid plate 205 and reduces deformation of the heat exchanger 200 during use. advantageous to

FIG. 8 shows another embodiment of a heat exchanger 200. In this embodiment, the heat exchanger 200 is an evaporator 103 having a plurality of structures 203. The features shown in FIG. 8 may be provided in combination with other features of heat exchanger 200 in any of FIGS. 2-7B.

The heat exchanger 200 includes the substrate 201 , a plurality of structures 203 extending from the substrate 201 , and a cover plate 205 . At least a portion of the plurality of structures 203 extend through the lid plate 205. The substrate 201 is thermally coupled to a heat source 701. The cover plate 205 is joined to the substrate 201 and the structure 203 by a brazing joint 707.

A coupling means 801 is provided at an end of the structure 203 extending through the cover plate 205 . The coupling means 801 may include the brazing material or any other suitable means.

The coupling means 801 may provide additional strength in addition to the brazed joints 707 between the lid plate 205 and the structure 203 and/or the substrate 201. The additional coupling means 801 can avoid deformation of the heat exchanger 200 during use.

FIG. 9 shows the fabrication of an exemplary two-phase cooling system 101 that includes the evaporator 103 and the condenser 105. The evaporator 103 and the condenser 105 are heat exchangers 200 that are shown in any of FIGS. 2-8 or may include any combination of the features shown in FIGS. 2-8.

The evaporator 103 may be installed in an additional frame before being installed and used in a system such as a server. The additional frame may be a rigid frame made of plastic or any other suitable material. The rigid frame can prevent people from directly touching the evaporator 103 so as to prevent the evaporator 103 from being damaged. The additional frame may also act as insulation to avoid unnecessary airflow affecting the evaporator 103.

To form the two-phase cooling system 101, the evaporator 103 and the condenser 105 may be vacuum brazed. Vacuum brazing of the evaporator 103 mechanically couples the lid plate 205 to the substrate 201 and the evaporator fins 305. Vacuum brazing of the condenser 105 mechanically couples the two lid plates 205 to the substrate 201 or other suitable components. The substrate 201 of the condenser 105 may consist of a double-sided fin plate or other suitable type of plate.

The evaporator 103 and the condenser 105 are connected to an ascending pipe 109 and a descending pipe 107 via a joint 901, as shown by arrows. The junction 901 is formed into a closed loop of the two-phase cooling system 101. The joint 901 may have the same inlet diameter as the downcomer pipe 107 and the riser pipe 109. This is advantageous in preventing pressure drops within the two-phase cooling system 101 and maximizing or substantially maximizing passive flow circulation.

The various components of the two-phase cooling system 101 may be connected to each other by any suitable means. In the embodiment of FIG. 9, the evaporator 103 and the condenser 105 are connected to the ascending pipe 109 and the descending pipe 107 by laser spot welding the inner periphery of the joint 901.

In the embodiment shown in FIG. 9, the two-phase cooling system 101 further includes a fill port 903. The fill port 903 can provide working fluid 113 to the two-phase cooling system 101. The filling port 903 is provided in the downcomer pipe 107. In this embodiment, the fill port 903 is provided at the top of the downcomer pipe 107 near the condenser 105.

The term "comprising" as used herein has an inclusive rather than an exclusive meaning. That is, all references that include Y in X indicate that X may include only one Y, or may include two or more Y's.

According to this specification, reference may be made to various embodiments. A description of a feature or functionality in connection with an embodiment indicates that the feature or functionality is present in that embodiment. References in this application to "an embodiment," "for example," "may," or "could" refer to such feature or functionality, whether or not explicitly stated otherwise. Whether or not it is mentioned as an example, indicates that it is present in at least the described example, and may be present in some or all of the other examples, but does not necessarily have to be present. Thus, references in this application to "an example," "for example," "may," or "could" refer to a particular example within a class of examples. A property of an example may be a property belonging only to the example, a property of the class, or a property of a subclass of the class (including some of the class, but not all examples). Accordingly, features described with reference to one embodiment and not described with reference to another embodiment may, to the extent possible, be used in other embodiments as part of a working combination, but not necessarily. It is implied that it need not be used in other embodiments.

Although the embodiments of the present application have been described in detail as in the above paragraph, the present application is not limited to the above embodiments. It should be understood that any modifications, equivalent substitutions, improvements, etc. made based on the ideas and principles of this application are included in the protection scope of this application.

The features described in the above description may be used in combinations other than those explicitly described above.

Although features are described with reference to particular features, those features may be performable by other features, whether or not described.

Although features are described with reference to particular embodiments, those features may also be present in other embodiments, whether or not described.

References to "a" or "the" in this application are intended to have an inclusive rather than an exclusive meaning. In other words, "X includes Y/said Y" mentioned in this application may mean that X includes only one Y or two or more Y, unless the context clearly indicates otherwise. Indicates that you may prepare. When using "a" or "the" with an exclusive meaning, the context needs to be clear. In some cases, "at least one" or "one or more" may be used to emphasize an inclusive meaning, but the omission of these terms should not be considered as inferring an exclusive meaning. .

A feature (or combination of features) in a claim is the feature or (combination of features) itself and a feature (equivalent feature) that can achieve substantially the same technical effect. Equivalent features include, for example, variant features that achieve substantially the same result in substantially the same way. Equivalent features include, for example, features that perform substantially the same function in substantially the same way to achieve substantially the same result.

In this specification, various embodiments may be referred to using adjectives or adjective phrases to describe features of the embodiments. A description of a property in connection with an embodiment indicates that the property is present in some embodiments as expressly described and in other embodiments substantially as described.

Although the above specification has endeavored to draw attention to what are considered to be important features, Applicants hereby acknowledge that the above drawings and/or any patents illustrated in the drawings, whether highlighted or not, It is to be understood that protection may be sought through the claims to protect any possible feature or combination of features.

101 Two-phase cooling system 103 Evaporator 105 Condenser 105 Liquid-cooled condenser 107 Downcomer pipe 109 Riser pipe 111 Heat source 113 Working fluid 117 Liquid phase 121 Vapor phase 125 Coolant 200 Heat exchanger 200 Two-phase heat exchanger 201 Substrate 203 Structure 205 Cover plate 301 Wiring 301 Wire 305 Evaporator fins 401, 403, 405, 407 Blocks 501 Dots 503 Interconnection network 505 Gap, circular gap 601 Reinforcement 601 Reinforcement structure 603 Protrusion 701 Heat source 703 Inlet portion 705 Central portion 707 Joint portion 801 Coupling means 901 Joint portion 903 Filling port

Claims (15)

a plurality of structures extending from the substrate and having adjacent structures separated by at least a first distance;
at least one lid plate disposed at an end of the plurality of structures so as to be separated from the end of the plurality of structures by a second distance smaller than the first distance,
The at least one lid plate is brazed to the plurality of structures by a brazing material provided between an end of the plurality of structures and the at least one lid plate, and the brazing material is brazing from a brazing material flowing into the spacing between the at least one lid plate and the ends of the plurality of structures by being provided in a discontinuous configuration such that gaps are provided between sections of material; a joint is formed;
Heat exchanger. the brazing material is provided with a thickness less than the first distance;
The heat exchanger according to claim 1. the first distance and the second distance are selected such that Laplace pressure causes the brazing material to flow into the gap between the ends of the plurality of structures and the at least one lid plate;
The heat exchanger according to claim 1 or 2. the plurality of structures extending substantially perpendicularly from the substrate;
The heat exchanger according to any one of claims 1 to 3. The plurality of structures are arranged closer to each other at an edge of the substrate than at a center of the substrate,
The heat exchanger according to any one of claims 1 to 4. a reinforcement including a plurality of protrusions configured to extend between the plurality of structures to limit bending of the plurality of structures;
The heat exchanger according to any one of claims 1 to 5. At least some of the plurality of structures extend through the at least one lid plate, and an end of the plurality of structures extending through the at least one lid plate includes a further a coupling means is arranged;
The heat exchanger according to any one of claims 1 to 6. the plurality of structures include fins,
The heat exchanger according to any one of claims 1 to 7. The heat exchanger includes an evaporator or a condenser.
The heat exchanger according to any one of claims 1 to 8. providing a plurality of structures extending from the substrate, the plurality of structures being separated by at least a first distance;
providing a brazing material that overlaps at least some of the plurality of structures, the brazing material being provided in a discontinuous configuration such that gaps are provided between portions of the brazing material;
providing at least one lid plate disposed at an end of the plurality of structures so as to be spaced apart from an end of the plurality of structures by a second distance smaller than the first distance; heating the brazing material such that the brazing material flows into a space between the at least one lid plate and an end of the plurality of structures;
Method. the brazing material is provided with a thickness less than the first distance;
The method according to claim 10. the first distance and the second distance are selected such that Laplace pressure causes the brazing material to flow into the gap between the ends of the plurality of structures and the at least one lid plate;
The method according to claim 10 or 11. A substrate and
a plurality of structures extending from the substrate; and at least one protrusion configured to extend between the plurality of structures to reduce bending of the plurality of structures. one reinforcement;
Heat exchanger. The heat exchanger includes a lid plate with the at least one reinforcement provided as part of the lid plate.
The heat exchanger according to claim 13. A substrate and
a plurality of structures extending from the substrate;
configured to provide a larger flow path for the flow of working fluid toward the center of the substrate than the edges of the substrate;
Heat exchanger.

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