Heat exchanger with a fluidized particle bed

Abstract

A cold plate for a heat exchanger system may include a base that is in thermal communication with a heat load, one or more walls extending from the base, a first fluid path through the cold plate, and a plurality of particles arranged within the first fluid path, or any combination thereof. The first fluid path may have an inlet and an outlet and / or may be bounded on at least two sides by walls. The plurality of particles may be fluidically confined within the first fluid path between the inlet and the outlet. The plurality of particles may be loosely arranged within the vertical portion of the first fluid path.

Description

Technical Field

[0001] 〔Cross - Reference to Related Applications〕 This application claims the benefit of U.S. Patent Provisional Application 63 / 520,576, filed Aug. 18, 2023, the entire content of which is incorporated herein by reference.

[0002] This disclosure generally relates to heat exchangers, and more specifically, to cold plate heat exchangers.

Background Art

[0003] As manufacturers increasingly develop more advanced chip architectures, more and more transistors are fitted onto smaller wafers of silicon, and the power density increases significantly. In high - density applications, air cooling does not provide sufficient heat flux to maintain chip temperature, which leads to overheating and throttling of performance. Direct - to - chip (directly to microtubes etc.) and two - phase cooling can be required for the highest - density cooling applications.

[0004] Forced two - phase cooling using a cold plate has been shown to be an effective way to achieve a high critical heat flux (i.e., the maximum heat per unit area that a given device can reasonably be cooled, or the heat flux at which boiling ceases to be an effective form of heat transfer from a solid surface to a liquid). Two - phase cooling achieves a high critical heat flux by boiling the coolant / refrigerant and maintaining a nearly uniform temperature across the cold plate. Heat is removed as the vapor exits and is condensed using a heat rejection device.

[0005] While forced two-phase cooling can be effective in maintaining a nearly perfectly uniform temperature gradient, the boiling liquid on the surface of the cold plate walls can generate slightly superheated steam. The expansion of the steam prevents rewetting and causes temporary dry spots to form. The steam in these areas has lower thermal conductivity and can be superheated before bubbling, which leads to reduced heat transfer and an increase in surface temperature. [Overview of the project]

[0006] The applicant has created novel and useful devices, systems, and methods for heat exchangers such as cold plates. In at least one embodiment, the cold plate for a heat exchanger system according to the Disclosure may include a base configured to be in thermal communication with a heat load, a first pair of walls extending from the base, a first fluid path through the cold plate, a plurality of particles arranged within the first fluid path, or any combination thereof. In at least one embodiment, the first fluid path may have an inlet and an outlet and / or be bounded on at least two sides by the first pair of walls. In at least one embodiment, the plurality of particles may be fluidically confined within the first fluid path between the inlet and the outlet. In at least one embodiment, the plurality of particles may be loosely arranged within the first fluid path. In at least one embodiment, the first fluid path may have a vertical portion, and the plurality of particles may be confined within the vertical portion.

[0007] In at least one embodiment, the particles may be thermally conductive particles. In at least one embodiment, the particles may include metallic particles. In at least one embodiment, the particles may be configured to increase the rate of heat transfer from the first pair of walls to the two-phase cooling fluid. In at least one embodiment, the particles may be configured to fluidize the cooling fluid, e.g., a single-phase subcooled cooling fluid or a two-phase saturated cooling fluid, as it moves through the first fluid path. Thermally conductive particles may be configured to transfer heat through particle-wall collisions and / or particle-particle collisions, etc. In at least one embodiment, the particles may be configured to resist vapor insulation of at least a portion of one or more walls or other surfaces during two-phase cooling of the cold plate. In at least one embodiment, the particles may be configured to induce or increase turbulent flow in at least a portion of the first fluid path.

[0008] In at least one embodiment, the cold plate may have fins extending from the base. In at least one embodiment, one wall of the first pair of walls may be a side wall of a fin. In at least one embodiment, the cold plate may have a plurality of fins extending from the base, a plurality of fluid paths through the cold plate, and a plurality of particles disposed within each of the plurality of fluid paths. In at least one embodiment, each of the plurality of fluid paths may have an inlet and an outlet and / or be bound on at least one side by one side wall of the plurality of fins. In at least one embodiment, the particles may be fluidically confined between the inlet and outlet of each of the plurality of fluid paths.

[0009] In at least one embodiment, the cold plate may have an inlet manifold fluid-communicating with the inlet of a first fluid path, an outlet manifold fluid-communicating with the outlet of the first fluid path, an inlet filter located fluid-downstream of the inlet manifold, an outlet filter located fluid-upstream of the outlet manifold, or any combination thereof. In at least one embodiment, a plurality of particles may be fluid-confined between the inlet filter and the outlet filter. In at least one embodiment, each particle of the plurality of particles may have a major dimension, the inlet filter may have an inlet filter size, and the outlet filter may have an outlet filter size. In at least one embodiment, the major dimension may be larger than the inlet filter size and / or the outlet filter size. In at least one embodiment, the inlet filter size and / or the outlet filter size may be different. In at least one embodiment, the inlet filter size and / or the outlet filter size may be configured to allow the cooling fluid to flow through the cold plate while the plurality of particles are fluid-confined within the first fluid path between the inlet and the outlet.

[0010] In at least one embodiment, the cold plate may have a first heat transfer coefficient when a first cooling fluid moves through the first fluid path at a first flow rate, with no particles present in the first fluid path. In at least one embodiment, the cold plate may have a second heat transfer coefficient when a first cooling fluid moves through the first fluid path at a first flow rate, with no particles present in the first fluid path. In at least one embodiment, the second heat transfer coefficient may be greater than the first heat transfer coefficient.

[0011] In at least one embodiment, the cold plate may have a first critical heat flux when a first cooling fluid moves through the first fluid path at a first flow rate, with no particles present in the first fluid path. In at least one embodiment, the cold plate may have a second critical heat flux when a first cooling fluid moves through the first fluid path at a first flow rate, with no particles present in the first fluid path. In at least one embodiment, the second critical heat flux may be greater than the first critical heat flux.

[0012] In at least one embodiment, the particles may be configured to increase the heat transfer rate from the first pair of walls to the two-phase cooling fluid. In at least one embodiment, the particles may be configured to fluidize as the two-phase cooling fluid or other cooling fluid moves through the first fluid path. In at least one embodiment, the particles may include metallic particles.

[0013] In at least one embodiment, the heat exchanger according to the present disclosure may include one or more cold plates. In at least one embodiment, any or all of the cold plates may include a base configured to be positioned in thermal communication with a heat load, a plurality of fins extending from the base, a plurality of fluid paths through the cold plate, each of which has an inlet and an outlet, a plurality of particle sets, each of which is positioned in a corresponding fluid path among the plurality of fluid paths, and a prime mover configured to circulate a two-phase cooling fluid through the plurality of fluid paths at a rate sufficient to fluidize each of the plurality of particle sets, or any combination thereof. In at least one embodiment, each of the plurality of fluid paths through the cold plate may have a vertically oriented portion. In at least one embodiment, the particle sets may be confined within the vertically oriented portion by a filter. In at least one embodiment, the fluidized particle sets may resist vapor insulation of one or more heat transfer surfaces during the cooling of one or more cold plates.

[0014] In at least one embodiment, the cooling method according to the present disclosure may include arranging a cold plate in thermal communication with a thermal load, moving a two-phase cooling fluid through a fluid path in the cold plate, fluidizing a set of particles arranged in the fluid path, or any combination thereof. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a block diagram of one of many embodiments of the heat exchanger system according to this disclosure.

[0016] [Figure 2] Figure 2 is a cross-sectional view of one of many embodiments of the heat exchanger system of Figure 1, along line AA.

[0017] [Figure 3]FIG. 3 is another cross-sectional view of many embodiments of a portion of the heat exchanger system of FIG. 1 taken along line AA.

[0018] [Figure 4] FIG. 4 is yet another cross-sectional view of many embodiments of a portion of the heat exchanger system of FIG. 1 taken along line AA.

[0019] [Figure 5] FIG. 5 is a side view of one of many embodiments of a portion of the heat exchanger system according to the present disclosure.

[0020] [Figure 6] FIG. 6 is a front view of one of many embodiments of a portion of the heat exchanger system according to the present disclosure.

[0021] [Figure 7] FIG. 7 is a schematic block diagram of one of many embodiments of a portion of the heat exchanger system according to the present disclosure.

[0022] [Figure 8] FIG. 8 is a front view of one of many embodiments of a portion of the heat exchanger system according to the present disclosure.

[0023] [Figure 9] FIG. 9 is a schematic diagram of one of many embodiments of the fluid flow path of the heat exchanger system according to the present disclosure.

[0024] [Figure 10] FIG. 10 is another schematic diagram of one of many embodiments of the fluid flow path of the heat exchanger system according to the present disclosure.

[0025] [Figure 11] FIG. 11 is a schematic diagram of a vapor pocket within the fluid flow path of the heat exchanger system according to the present disclosure. <00​​​Figure 12 is a simplified diagram of particles reacting with vapor pockets in the fluid flow path of the heat exchanger system according to this disclosure.

[0027] [Figure 13] Figure 13 is a simplified diagram of particles in the fluid flow path of the heat exchanger system according to this disclosure.

[0028] [Figure 14] Figure 14 is an exemplary chart illustrating the relationship between wall heat flux and wall overheating in a fluid flow path of a particle-free heat exchanger system according to the present disclosure.

[0029] [Figure 15] Figure 15 is an exemplary chart illustrating the relationship between wall heat flux and wall overheating in a fluid flow path of a heat exchanger system having particles inside, according to the present disclosure. [Modes for carrying out the invention]

[0030] The above-mentioned figures and the following descriptions of specific structures and functions are not presented to limit the scope of the applicant's invention or the scope of the appended claims. Rather, the drawings and written descriptions are provided to teach a person skilled in the art how to create and use the invention for which patent protection is sought. A person skilled in the art will understand that not all features of commercial embodiments of the invention are described or illustrated for clarity and understanding. A person skilled in the art will also understand that the development of actual commercial embodiments incorporating aspects of the invention will require a number of implementation-specific decisions to achieve the ultimate goals of the developer of the commercial embodiment. Such implementation-specific decisions may include, but are likely not limited to, compliance with system-related constraints, business-related constraints, government-related constraints, and other constraints, and may vary depending on the particular implementation, location, and from time to time. The developer's efforts may be complex and time-consuming in an absolute sense, but nevertheless, such efforts are routine work for a person skilled in the art who is interested in this disclosure. It should be understood that the invention disclosed and taught herein is susceptible to a number of different modifications and alternative forms.

[0031] The use of singular terms such as "a," but not limited to them, is not intended to limit the number of items. Furthermore, the use of relational terms such as "top," "bottom," "left," "right," "upper," "lower," "down," "upper," and "side" is used in written descriptions to clarify specific references to the drawings and is not intended to limit the scope of the invention or the appended claims. The terms "including" and "such as" are illustrative and not restrictive. The terms “couple,” “coupled,” “coupling,” “coupler,” and similar terms are used herein and may include, but may not be limited to, any method or device for securing, binding, bonding, fastening, attaching, joining, inserting, forming on or inside, communicating, or otherwise associating one or more members together, for example, mechanically, magnetically, electrically, chemically, operably, directly or indirectly by an intermediate element. The coupling may occur in any direction, including rotational. Furthermore, all parts and components of this disclosure that can be physically embodied essentially include hypothetical and actual characteristics, including, but not limited to, features such as shafts, ends, inner and outer surfaces, internal spaces, tops, bottoms, sides, boundaries, dimensions (e.g., height, length, width, thickness), mass, weight, volume, and density, whether such features are expressly described herein or not.

[0032] The applicant has created novel and useful devices, systems, and methods for heat exchangers such as cold plates. The inventions disclosed herein enable higher critical heat flux and, in general, improve the thermal performance of heat exchangers such as cold plates. In at least one embodiment, the heat exchanger such as a cold plate utilizes a bed of conductive particles that are fluidized or suspended in a fluid by the flow of a refrigerant. Such fluidized particles can assist or improve heat transfer in one or more ways. The methods include, for example, causing vapor formation and the breakdown of dry-out spots; disrupting a reasonable mechanism governing the critical heat flux of fluid boiling; disrupting the separation of vapor blankets on hot walls or other surfaces from the bulk flow; disrupting high-density bubble clusters adjacent to hot surfaces; disrupting bubble aggregates near liquid sublayers near hot surfaces; colliding with bubble formations on the wall surface, breaking them and mixing them with the bulk fluid; for example, breaking the surface tension of vapor and re-wetting dry spots on the wall in the event of interfacial separation between the liquid surface and the hot wall; colliding with the wall and conducting heat, thereby providing wall-particle conduction; colliding with other particles and conducting heat, thereby providing particle-particle conduction; boosting the heat transfer region; providing nucleation sites and promoting boiling at lower temperatures; generally, increasing turbulence; or any combination thereof. Such particles can be carried away from the wall by the fluid and cooled from the critical region.

[0033] Figure 1 is a block diagram of one of many embodiments of the heat exchanger system according to the present disclosure. Figure 2 is a cross-sectional view of one of many embodiments of a portion of the heat exchanger system of Figure 1 along line AA. Figure 3 is another cross-sectional view of one of many embodiments of a portion of the heat exchanger system of Figure 1 along line AA. Figure 4 is yet another cross-sectional view of one of many embodiments of a portion of the heat exchanger system of Figure 1 along line AA. Figure 5 is a side view of one of many embodiments of a portion of the heat exchanger system according to the present disclosure. Figure 6 is a front view of one of many embodiments of a portion of the heat exchanger system according to the present disclosure. Figure 7 is a simplified block diagram of one of many embodiments of a portion of the heat exchanger system according to the present disclosure. Figure 8 is a front view of one of many embodiments of a portion of the heat exchanger system according to the present disclosure. Figure 9 is a simplified diagram of one of many embodiments of the fluid flow path of the heat exchanger system according to the present disclosure. Figure 10 is another simplified diagram of one of many embodiments of the fluid flow path of the heat exchanger system according to the present disclosure. Figure 11 is a simplified diagram of a vapor pocket in the fluid flow path of a heat exchanger system according to the present disclosure. Figure 12 is a simplified diagram of particles reacting with a vapor pocket in the fluid flow path of a heat exchanger system according to the present disclosure. Figure 13 is a simplified diagram of particles in the fluid flow path of a heat exchanger system according to the present disclosure. Figure 14 is an exemplary chart illustrating a mode of the relationship between wall heat flux and wall superheating in the fluid flow path of a heat exchanger system without internal particles according to the present disclosure. Figure 15 is an exemplary chart showing a mode of the relationship between wall heat flux and wall superheating in the fluid flow path of a heat exchanger system with internal particles according to the present disclosure. Figures 1 to 15 are described in relation to each other.

[0034] In at least one embodiment, the heat exchanger or heat exchanger system 200 according to the Disclosure may include one or more cold plates 100 for cooling one or more heat loads, such as electronic components used in a data center. In at least one embodiment, the cold plate 100 according to the Disclosure may include one or more bases 102 configured to be in thermal communication with one or more heat loads 202, two or more walls 104 extending from the bases 102, one or more fluid paths 106 through the cold plate 100, a plurality of particles 108 arranged within the one or more fluid paths 106, or any combination thereof. In at least one embodiment, the heat exchanger system 200 may include one or more secondary heat exchangers 204 for releasing the heat extracted from the heat loads 202 by the cold plate 100. In at least one embodiment, the heat exchanger system 200 may include one or more prime movers 206, such as pumps or compressors, for circulating one or more cooling fluids or working fluids, such as two-phase cooling fluids, through the fluid paths 106 of the cold plate 100.

[0035] For illustrative purposes, in at least one embodiment, as shown in Figures 1-8, the cold plate 100 may be a solid-fluid heat exchanger, such as a direct-to-tip heat exchanger for direct thermal communication with heat-generating electronic components. However, this is not necessarily required, and other embodiments are conceivable. For example, in at least one embodiment, the cold plate 100 may be or include a fluid-fluid heat exchanger, an air-fluid heat exchanger, or another type of heat exchanger according to the implementation of the Disclosure. Similarly, in at least one embodiment, the heat exchanger system 200 or cold plate 100 may utilize a two-phase cooling fluid or refrigerant. However, phase-change cooling is not necessarily required, and in at least one embodiment, the heat exchanger system 200 or cold plate 100 may utilize a single-phase cooling fluid or a combination of two or more cooling fluids.

[0036] In at least one embodiment, the fluid path 106 may have one or more inlets 112 from an inlet manifold, etc., and one or more outlets 114 to an outlet manifold, etc., and / or may be bounded on one or more sides by one or more walls 104 such as a side wall of the cold plate 100, one side wall of the fins 122, another heat transfer surface of the cold plate 100, or a combination thereof. In at least one embodiment, particles 108 may be fluidically confined within the fluid path 106 or a portion thereof between the inlets 112 and the outlets 114 by an inlet filter 116 and / or an outlet filter 118, etc. In at least one embodiment, particles 108 may be loosely arranged, entrained, or suspended within the fluid path 106, for example, fluidically. In at least one embodiment, particles 108 may be loosely arranged within the fluid path 106. In at least one embodiment, the fluid path 106 may have a vertical portion, and particles 108 may be confined within the vertical portion.

[0037] In at least one embodiment, one or more tanks, storage compartments, and / or recirculation paths may be in fluid communication with one or more fluid paths 106 to store and / or route (route, control, route) at least a portion of the particles 108 to resist or prevent clogging during the cooling operation. For example, in at least one embodiment, the outlet filter 118 may be inclined or angled with respect to the fluid path 106, or otherwise configured to release or deflect particles 108 impacting it toward or into a tank upstream of the outlet filter 118 or recirculation path 130. In at least one embodiment, the recirculation path or circuit 130 may direct particles toward the inlet end of the fluid path 106, or otherwise into the fluid path 106 upstream of the outlet filter, thereby relocating or reusing the particles 108 for the cooling operation and / or preventing the particles 108 from clogging the outlet filter 118. In at least one embodiment, a pump, compressor, conveyor, or other mechanism 132 can be used to clean the outlet filter 118 and / or recirculate the particles 108.

[0038] In at least one embodiment, the particles 108 may be thermally conductive particles that can be made from any thermally conductive material required or desired for the implementation of the present disclosure. In at least one embodiment, the particles 108 may include metallic particles. In at least one embodiment, the particles 108 may include conductive metallic particles such as copper, aluminum, steel, brass, titanium, lead, any of the above alloys, or any combination thereof. In at least one embodiment, the particles 108 may be made from a metal or alloy that is whole or partially oxidation-resistant or corrosion-resistant (e.g., stainless steel), which can help reduce the possibility that oxidation or corrosion may adversely affect the heat transfer process. However, this is not necessarily required, and materials with relatively low corrosion resistance can also be used.

[0039] In at least one embodiment, the particle 108 can be macroscopic in scale. For example, in at least one embodiment, the particle 108 can have a diameter of 0.1 mm to 6 mm or other cross-sectional dimensions, or other dimensions according to embodiments of the present disclosure. In at least one embodiment, one or more particles 108 can be spherical, cylindrical, polyhedron, oval, irregular, or other shapes according to the implementation of the present disclosure. As another example, one or more particles 108 can be spiked ball shape, or, for example, star-shaped or jack-shaped (i.e., a shape similar to a six-pointed star with round, pointed, or otherwise shaped points).

[0040] In at least one embodiment, the physical properties of particles 108 for a given implementation of the Disclosure may depend at least in part on the type of working fluid or cooling fluid being used (and vice versa), which may be or include any particle properties and / or type of fluid in an implementation of the Disclosure. For example, in at least one embodiment, chip throttling (a working control for managing the heat generation of the chip) may be set to 90°C or about 90°C, and the implementation of the Disclosure may be configured accordingly. As another example, in at least one embodiment, the working fluid temperature for a relatively high-density chip may be 50°C or about 50°C (or less), and the implementation of the Disclosure may be configured accordingly. Similarly, a wide variety of refrigerants or coolants may be used as needed or desired for a given implementation of the Disclosure. For example, common two-phase fluids used in IT cooling applications may include (but are not limited to) fluorochemical or fluorocarbon fluids, but other fluids may also be used in one or more embodiments of this disclosure depending on relevant design factors such as performance impact, maintenance, chemical or material compatibility, electrical properties, flammability, environmental considerations, boiling point or other physical properties, and safety considerations.

[0041] In at least one embodiment, the particles 108 may be uniform in size and shape. In at least one embodiment, the particles 108 may be of different sizes and / or shapes. In at least one embodiment, the particles 108 may be uniform in size and / or shape in one fluid path 106a and of different sizes and / or shapes in another fluid path 106b. In at least one embodiment, the particles 108 may be of yet different sizes and / or shapes in one or more other fluid paths 106c...106n (collectively referred to as fluid paths 106).

[0042] In at least one embodiment, the particles 108 may have a uniform mass and density. In at least one embodiment, the particles 108 may have different masses and / or densities. In at least one embodiment, the particles 108 may have a uniform mass and / or density in one fluid path 106a and different masses and / or densities in another fluid path 106b. In at least one embodiment, the particles 108 may have yet different masses and / or densities in one or more other fluid paths 106.

[0043] In at least one embodiment, the particles 108 can be shaped, sized, and / or otherwise arranged to promote or support turbulent flow through at least a portion of the cold plate 100 in order to increase heat transfer from the cold plate 100 to the cooling fluid. In at least one embodiment, the particles 108 can be shaped, sized, and / or otherwise arranged to avoid the particles 108 packing tightly together, so as to minimize the opportunity to clog or excessively restrict the flow path 106 through the cold plate 100 or the fluid path 106.

[0044] In at least one embodiment, the particles 108 can be configured to increase the rate of heat transfer from the wall 104 to the two-phase cooling fluid, for example, compared to such embodiments in the absence of the particles 108. In at least one embodiment, the particles 108 can be configured to fluidize when the cooling fluid is forced or otherwise moved through the fluid path 106, for example, at (or beyond) a fluidization rate. In at least one embodiment, the particles 108 can be configured to fluidize when a one-phase subcooled cooling fluid or a two-phase saturated cooling fluid is forced or otherwise moved through the fluid path 106 at a fluidization rate. In at least one embodiment, the thermally conductive particles 108 can be configured to transfer heat through particle-wall collisions and / or particle-particle collisions, etc. In at least one embodiment, the particles 108 can be configured to resist vapor insulation 138 of at least a portion of the wall 104 of the cold plate 100 and / or one or more other surfaces during two-phase cooling of the cold plate 100. In at least one embodiment, the particles 108 can be configured to induce or increase turbulence in at least a portion of the fluid path 106.

[0045] In at least one embodiment, the cold plate 100 may have one or more fins 122 extending from a base 102. In at least one embodiment, one or more walls 104 may be side walls of the fins 122. In at least one embodiment, the cold plate 100 may have a plurality of fins 122 extending from a base 102, a plurality of fluid paths 106 passing through the cold plate 100, and a plurality of particles 108 or sets of particles 108 disposed within one or more fluid paths 106. In at least one embodiment, each of the plurality of fluid paths may have an inlet 112 and an outlet 114 and / or may be bounded on at least one side by a side wall 104 of the cold plate 100, such as a side wall 104 of one of the fins 122. In at least one embodiment, particles 108 in one of the corresponding fluid paths 106 can be fluidically trapped between the inlet 112 and outlet 114 of the fluid path 106, or between the corresponding inlet filter 116 and outlet filter 118. In at least one embodiment, the cold plate 100 may have one or more fins 122 extending from the base 102 across the entire fluid path 106, thereby dividing the fluid path 106 into multiple fluid paths (see, for example, fluid paths 106a, 106b, 106c). Such divisions may extend along the entire length of the fluid path 106 or along only a portion thereof. In at least one embodiment, the cold plate 100 may have one or more fins 122 extending from the base 102 across the fluid path 106, thereby segmenting the fluid path 106. Such segmentations may extend along the entire length of the fluid path 106 or along only a portion thereof.

[0046] In at least one embodiment, the cold plate may include an inlet manifold 140 that fluidly communicates with an inlet 112 of a fluid path 106, an outlet manifold 142 that fluidly communicates with an outlet 114 of a fluid path 106, an inlet filter 116 located fluidly downstream of the inlet manifold 140, an outlet filter 118 located fluidly upstream of the outlet manifold 142, or any combination thereof. In at least one embodiment, particles 108 can be fluidly confined between the inlet filter 116 and the outlet filter 118. In at least one embodiment, each particle 108 may have a main dimension, the inlet filter 116 may have an inlet filter size, and the outlet filter 118 may have an outlet filter size. In at least one embodiment, the main dimension may be larger than the inlet filter size and / or the outlet filter size. In at least one embodiment, the inlet filter size and the outlet filter size may be different. In at least one embodiment, the inlet filter size and / or outlet filter size can be configured to allow the cooling fluid to flow through the cold plate 100 while the particles 108 are fluidly confined within the fluid path 106 between the inlet 112 and the outlet 114 and / or between the inlet filter 116 and the outlet filter 118.

[0047] In at least one embodiment, the cold plate 100 may have a first heat transfer coefficient when the cooling fluid moves through the fluid path 106 at a first flow rate, with no particles 108 present in the fluid path 106. In at least one embodiment, the cold plate 100 may have a second heat transfer coefficient when the cooling fluid moves through the fluid path 106 at a first flow rate, with particles 108 present in the fluid path 106. In at least one embodiment, the second heat transfer coefficient may be greater than the first heat transfer coefficient. In at least one embodiment, the presence of particles 108 present in the fluid path 106 contributes to the second heat transfer coefficient being greater than the first heat transfer coefficient. In at least one embodiment, the presence of particles 108 present in the fluid path 106 may cause the second heat transfer coefficient to be greater than the first heat transfer coefficient, for example, by improving heat transfer in one or more ways discussed herein.

[0048] In at least one embodiment, the cold plate 100 may have a first critical heat flux when the cooling fluid moves through the fluid path 106 at a first flow rate, with no particles 108 present in the fluid path 106. In at least one embodiment, the cold plate 100 may have a second critical heat flux when the cooling fluid moves through the fluid path 106 at a first flow rate, with particles 108 present in the fluid path 106. In at least one embodiment, the second critical heat flux may be greater than the first critical heat flux. In at least one embodiment, the presence of particles 108 present in the fluid path 106 contributes to the second critical heat flux being greater than the first critical heat flux. In at least one embodiment, the presence of particles 108 placed within the fluid path 106 can cause a second critical heat flux to be greater than the first critical heat flux, for example, by improving heat transfer in one or more ways discussed herein.

[0049] In at least one embodiment, the particles 108 can be configured to increase the heat transfer rate from the wall 104 to the two-phase cooling fluid. In at least one embodiment, the particles 108 can be configured to fluidize when the two-phase cooling fluid moves through the fluid path 106 at a speed sufficient to fluidize the particles 108, and this speed can be or include any speed according to embodiments of the present disclosure. In at least one embodiment, the fluid path 106 can be bounded by a base 102, one or more opposing walls 124, and one or more side walls 104. In at least one embodiment, heat can be transferred from the heat load 202 to the base 102 and to the opposing walls 124 through or via the side walls 104 or fins 122. In at least one embodiment, the particles 108 can be configured to increase the heat transfer rate from the base 102, the opposing walls 124, the side walls 104, or any combination thereof to the two-phase cooling fluid.

[0050] In at least one embodiment, the heat exchanger system 200 according to the present disclosure may include one or more cold plates 100. In at least one embodiment, any or all of the cold plates 100 may include a base 102 configured to be in thermal communication with a heat load 202, a plurality of fins 122 extending from the base 102, and a plurality of fluid paths 106 through the cold plate 100. In at least one embodiment, each of the fluid paths 106 may have an inlet 112 and an outlet 114, and a plurality of particles 108 disposed inside. In at least one embodiment, the system 200 may include one or more prime movers 206, such as pumps or compressors, or any combination thereof, for circulating a two-phase cooling fluid or other cooling fluid through the fluid paths 106 at a rate sufficient to fluidize each of the plurality of particles 108 sets. In at least one embodiment, each of the fluid paths 106 through the cold plate 100 may have a vertically oriented portion. In at least one embodiment, a set of particles 108 can be confined within a vertically oriented portion by filters 116, 118, etc. In at least one embodiment, the fluidized particles 108 can resist vapor insulation 138 of one or more heat transfer surfaces during two-phase cooling of one or more cold plates 100.

[0051] In at least one embodiment, the method according to the present disclosure may include locating a cold plate 100 in thermal communication with a thermal load 202, moving a two-phase cooling fluid through a fluid path 106 of the cold plate 100, and fluidizing a set of particles 108 arranged in the fluid path 106, or any combination thereof. In at least one embodiment, the method may include resisting clogging of particles 108 by, for example, sending or retaining some or all of the particles 108 into or a recirculation path 130. In at least one embodiment, the method may include resisting vapor insulation 138 of one or more heat transfer surfaces by bringing the heat transfer surfaces into contact with one or more particles 108 during the cooling operation. In at least one embodiment, the method may include utilizing one or more particles 108 to cause vapor formation and the breakdown of dry-out spots, disrupting a reasonable mechanism governing the critical heat flux of fluid boiling, disrupting vapor blanket separation of a hot wall or other surface from the bulk flow, disrupting dense bubble clusters adjacent to the hot surface, disrupting bubble aggregates near the liquid sublayer near the hot surface, colliding with and breaking bubble formations on the wall surface and mixing them with the bulk fluid, for example, breaking the surface tension of the vapor and re-wetting dry spots on the wall in the event of interfacial separation between the liquid surface and the hot wall, colliding with the wall and conducting heat, thereby providing wall-particle conduction, colliding with other particles and conducting heat, thereby providing particle-particle conduction, boosting the heat transfer region, providing nucleation sites and promoting boiling at lower temperatures, generally increasing turbulence, or any combination thereof. In at least one embodiment, the method may include moving the particles 108 away from one or more heat transfer surfaces or heat transfer regions, and cooling the particles 108.

[0052] In at least one embodiment, a cold plate for a heat exchanger system according to the present disclosure may include a base configured to be in thermal communication with a heat load, a first pair of walls extending from the base, a first fluid path through the cold plate, a plurality of particles disposed within the first fluid path, or any combination thereof. In at least one embodiment, the first fluid path may have an inlet and an outlet and / or be bounded on at least two sides by the first pair of walls. In at least one embodiment, the plurality of particles may be fluidically confined within the first fluid path between the inlet and the outlet. In at least one embodiment, the plurality of particles may be loosely arranged within the first fluid path. In at least one embodiment, the first fluid path may have a vertical portion, and the plurality of particles may be confined within the vertical portion.

[0053] In at least one embodiment, the particles may be thermally conductive particles. In at least one embodiment, the particles may include metallic particles. In at least one embodiment, the particles may be configured to increase the rate of heat transfer from the first pair of walls to the two-phase cooling fluid. In at least one embodiment, the particles may be configured to fluidize as the two-phase cooling fluid moves through the first fluid path. In at least one embodiment, thermally conductive particles may be configured to transfer heat through particle-wall collisions and / or particle-particle collisions, etc. In at least one embodiment, the particles may be configured to resist vapor insulation of at least a portion of one or more first pair of walls during two-phase cooling of the cold plate. In at least one embodiment, the particles may be configured to induce or increase turbulence in at least a portion of the first fluid path.

[0054] In at least one embodiment, the cold plate may have fins extending from its base. In at least one embodiment, one wall of the first pair of walls may be a side wall of a fin. In at least one embodiment, the cold plate may have a plurality of fins extending from its base, a plurality of fluid paths through the cold plate, and a plurality of particles disposed within each of the plurality of fluid paths. In at least one embodiment, each of the plurality of fluid paths may have an inlet and an outlet and / or be bounded on at least one side by one side wall of the plurality of fins. In at least one embodiment, the particles may be fluidically confined between the inlet and outlet of each of the plurality of fluid paths.

[0055] In at least one embodiment, the cold plate may have an inlet manifold fluid-communicating with the inlet of a first fluid path, an outlet manifold fluid-communicating with the outlet of the first fluid path, an inlet filter located fluid-downstream of the inlet manifold, an outlet filter located fluid-upstream of the outlet manifold, or any combination thereof. In at least one embodiment, a plurality of particles may be fluid-confined between the inlet filter and the outlet filter. In at least one embodiment, each particle of the plurality of particles may have a major dimension, the inlet filter may have an inlet filter size, and the outlet filter may have an outlet filter size. In at least one embodiment, the major dimension may be larger than the inlet filter size and / or the outlet filter size. In at least one embodiment, the inlet filter size and / or the outlet filter size may be different. In at least one embodiment, the inlet filter size and / or the outlet filter size may be configured to allow the cooling fluid to flow through the cold plate while the plurality of particles are fluid-confined within the first fluid path between the inlet and the outlet.

[0056] In at least one embodiment, the cold plate may have a first heat transfer coefficient when a first cooling fluid moves through the first fluid path at a first flow rate, with no particles present in the first fluid path. In at least one embodiment, the cold plate may have a second heat transfer coefficient when a first cooling fluid moves through the first fluid path at a first flow rate, with no particles present in the first fluid path. In at least one embodiment, the second heat transfer coefficient may be greater than the first heat transfer coefficient.

[0057] In at least one embodiment, the cold plate may have a first critical heat flux when the first cooling fluid moves through the first fluid path at a first flow rate, with no plurality of particles positioned in the first fluid path. In at least one embodiment, the cold plate may have a second critical heat flux when the first cooling fluid moves through the first fluid path at a first flow rate, with a plurality of particles positioned in the first fluid path. In at least one embodiment, the second critical heat flux may be greater than the first critical heat flux. In at least one embodiment, the plurality of particles may be configured to increase the rate of heat transfer from the first pair of walls to the two-phase cooling fluid. In at least one embodiment, the plurality of particles may be configured to fluidize as the two-phase cooling fluid moves through the first fluid path. In at least one embodiment, the plurality of particles may include metallic particles.

[0058] In at least one embodiment, the heat exchanger according to the present disclosure may include one or more cold plates. In at least one embodiment, any or all of the cold plates may include a base configured to be positioned in thermal communication with a heat load, a plurality of fins extending from the base, a plurality of fluid paths through the cold plate, each of which has an inlet and an outlet, a plurality of particle sets, each of which is positioned in a corresponding fluid path among the plurality of fluid paths, and a prime mover configured to circulate a two-phase cooling fluid through the plurality of fluid paths at a rate sufficient to fluidize each of the plurality of particle sets, or any combination thereof. In at least one embodiment, each of the plurality of fluid paths through the cold plate may have a vertically oriented portion. In at least one embodiment, the particle sets may be confined within the vertically oriented portion by a filter. In at least one embodiment, the fluidized particle sets may resist vapor insulation of one or more heat transfer surfaces during two-phase cooling of one or more cold plates. In at least one embodiment, the cooling method according to the present disclosure may include arranging a cold plate in thermal communication with a thermal load, moving a two-phase cooling fluid through a fluid path in the cold plate, fluidizing a set of particles arranged in the fluid path, or any combination thereof.

[0059] Other embodiments and further embodiments utilizing one or more aspects of this disclosure can be devised without departing from the spirit of the applicant's disclosure. For example, devices, systems, and methods can be implemented in many different industries for many different types and sizes. Furthermore, various methods and embodiments of devices, systems, and methods can be included in combination with one another to produce variations of the disclosed methods and embodiments. A discussion of a single element may include multiple elements, and vice versa. The order of steps can occur in various orders unless specifically limited. Various steps described herein can be combined with other steps, aligned with described steps, and / or divided into multiple steps. Similarly, elements are described functionally and can be embodied as separate components or combined into components having multiple functions.

[0060] The present invention is described in the context of preferred and other embodiments, and not all embodiments of the invention are described. Obvious modifications and changes to the described embodiments are available to those skilled in the art who are interested in this disclosure. The disclosed and undisclosed embodiments are not intended to limit or restrict the scope or applicability of the invention devised by the applicant, but rather, in accordance with patent law, the applicant intends to fully protect all such modifications and improvements that fall within the scope or range of the equivalents of the following claims.

Claims

1. A cold plate for a heat exchanger, wherein the cold plate is A base portion configured to be positioned in thermal communication with the heat load, A first pair of walls extending from the base, A first fluid path passing through the cold plate, the first fluid path having an inlet and an outlet, and being bounded on at least two sides by the first pair of walls, A plurality of particles arranged in the first fluid path, A cold plate in which the plurality of particles are fluidically confined within the first fluid path between the inlet and the outlet.

2. The cold plate according to claim 1, further comprising a fin extending from a base, wherein one wall of the first pair of walls is a side wall of the fin.

3. Multiple fins extending from the base, A plurality of fluid paths passing through the cold plate, each of which has an inlet and an outlet, and which is bounded on at least one side by one side wall of the plurality of fins, The cold plate according to claim 1, further comprising a plurality of particles arranged within each of the plurality of fluid paths and fluidly confined between the inlet and outlet thereof.

4. An inlet manifold that is in fluid communication with the inlet of the first fluid path, An outlet manifold that is in fluid communication with the outlet of the first fluid path, The inlet filter is located fluidly downstream of the inlet manifold, The outlet manifold further comprises an outlet filter located fluidly upstream of the outlet manifold, The cold plate according to claim 1, wherein the plurality of particles are fluidly confined between the inlet filter and the outlet filter.

5. The cold plate according to claim 4, wherein each of the plurality of particles has a main dimension, the inlet filter has an inlet filter size, the outlet filter has an outlet filter size, and the main dimension is larger than the inlet filter size and the outlet filter size.

6. The cold plate according to claim 5, wherein the inlet filter size and the outlet filter size are different.

7. The cold plate according to claim 5, wherein the inlet filter size and the outlet filter size are configured to allow the cooling fluid to flow through the cold plate while the plurality of particles are fluidically confined within the first fluid path between the inlet and the outlet.

8. The cold plate according to claim 1, wherein the plurality of particles are loosely arranged in the first fluid path.

9. The cold plate according to claim 1, wherein the first fluid path has a vertical portion, and the plurality of particles are confined within the vertical portion.

10. The cold plate according to claim 1, wherein the plurality of particles comprises thermally conductive particles, and the thermally conductive particles are configured to transfer heat via at least one of particle-wall collisions, particle-particle collisions, and combinations thereof.

11. The cold plate according to claim 1, wherein the plurality of particles are configured to resist vapor insulation of at least a portion of one or more of the first pair of walls during two-phase cooling of the cold plate.

12. The cold plate according to claim 1, wherein the plurality of particles are configured to cause or increase turbulence in at least a portion of the first fluid path.

13. The cold plate has a first heat transfer coefficient when the first cooling fluid moves through the first fluid path at a first flow rate, with the plurality of particles not arranged in the first fluid path. The cold plate has a second heat transfer coefficient when the first cooling fluid moves through the first fluid path at a first flow rate, with the plurality of particles arranged in the first fluid path. The cold plate according to claim 1, wherein the second heat transfer coefficient is greater than the first heat transfer coefficient.

14. The cold plate has a first critical heat flux when the first cooling fluid moves through the first fluid path at a first flow rate, with the plurality of particles not arranged in the first fluid path. The cold plate has a second critical heat flux when the first cooling fluid moves through the first fluid path at a first flow rate, with the plurality of particles arranged in the first fluid path. The cold plate according to claim 1, wherein the second critical heat flux is greater than the first critical heat flux.

15. The cold plate according to claim 1, wherein the plurality of particles are configured to increase the heat transfer rate from the first pair of walls to the two-phase cooling fluid.

16. The cold plate according to claim 1, wherein the plurality of particles are configured to become fluid when the two-phase cooling fluid moves through the first fluid path.

17. The cold plate according to claim 1, wherein the plurality of particles comprises metal particles.

18. It is a heat exchanger, One or more cold plates, each of the one or more cold plates is A base portion configured to be positioned in thermal communication with the heat load, Multiple fins extending from the base, A plurality of fluid paths passing through the cold plate, each of which comprises a plurality of fluid paths having an inlet and an outlet, and one or more cold plates, A plurality of particle sets, each of which is a plurality of particle sets arranged in a corresponding fluid path among the plurality of fluid paths, A heat exchanger comprising: a prime mover configured to circulate a two-phase cooling fluid through a plurality of fluid paths at a rate that fluidizes each of the plurality of particle sets.

19. The heat exchanger according to claim 18, wherein each of the plurality of fluid paths passing through the cold plate has a vertically oriented portion, and the particle set is confined within the vertically oriented portion by a filter.

20. The heat exchanger according to claim 19, wherein the fluidized particle set is configured to resist vapor insulation of one or more heat transfer surfaces during two-phase cooling of one or more cold plates.

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