Scalable Thermal Ride-Through for Immersion-Cooled Server Systems

Abstract

A thermal management system for a computing device includes an immersion tank having a cooling fluid therein, a computing device positioned within the cooling fluid in the immersion tank, and a thermal block positioned within the cooling fluid in the immersion tank, the computing device configured to heat the cooling fluid and the thermal block configured to contain heat from the cooling fluid, and the thermal block including fluid management features that direct the flow of the cooling fluid relative to the thermal block and the computing device.

Description

Technical Field

[0001] One embodiment of the present invention relates to, for example, scalable thermal ride-through for a liquid immersion cooling server system.

Background Art

[0002]

[0001] Computing devices can generate a large amount of heat during use. Computing components are susceptible to damage from heat and generally may require a cooling system to maintain component temperature within a safe range during heavy processing or usage loads. Liquid cooling can efficiently cool components because the liquid cooling fluid has a large heat mass compared to air or gas cooling. The liquid cooling fluid can be maintained at a low temperature by enabling a vaporizing fluid to be generated from the liquid. The vapor of the coolant can potentially have an adverse effect on the cooling performance of the cooling fluid. The vapor can be condensed and returned to the liquid immersion tank.

[0003]

[0002] In conventional liquid immersion cooling systems, most liquid immersion tanks contain a cooling fluid that functions as a heat sink and do not efficiently remove heat from the system through boiling. Despite the relatively low efficiency of including additional cooling fluid in the liquid immersion tank, high costs are associated with obtaining, including, and maintaining additional cooling fluid.

Summary of the Invention

Problems to be Solved by the Invention

[0004] One embodiment of the present invention relates to, for example, scalable thermal ride-through for a liquid immersion cooling server system.

Means for Solving the Problems

[0005]

[0003] In some embodiments, a thermal management system for a computing device includes a liquid immersion tank having a cooling fluid therein, a computing device positioned within the cooling fluid in the liquid immersion tank, and a heat block positioned within the cooling fluid in the liquid immersion tank. The computing device heats the cooling fluid, and the heat block is configured to receive heat from the cooling fluid. The heat block includes fluid management features that direct the flow of the cooling fluid with respect to the heat block and the computing device.

[0006]

[0004] In some embodiments, a thermal management system for a computing device includes a liquid immersion tank having a cooling fluid therein, a computing device positioned within the cooling fluid in the liquid immersion tank, and a heat block positioned within the cooling fluid in the liquid immersion tank. The computing device heats the cooling fluid, and the heat block is configured to receive heat from the cooling fluid. The heat block is a container having a second material therein.

[0007]

[0005] In some embodiments, a thermal management system for a computing device includes a liquid immersion tank having a cooling fluid therein, a computing device positioned within the cooling fluid in the liquid immersion tank, and a heat block positioned within the cooling fluid in the liquid immersion tank. The computing device heats the cooling fluid, and the heat block is configured to receive heat from the cooling fluid. The heat block is a container having a second material and a third material therein that are endothermically reactive with each other.

[0008]

[0006] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter.

[0009]

[0007] Further features and advantages will be described in the following description, and in part will be apparent from the description, or can be learned by practice of the teachings herein. The features and advantages of the present disclosure can be realized and obtained by the devices and combinations particularly pointed out in the appended claims. The features of the present disclosure will become more fully apparent from the following description and appended claims, or can be learned by practice of the embodiments of the disclosure described hereinafter.

[0010]

[0008] To explain how the above-described features and other features of the present disclosure can be obtained, a more specific description will be made by referring to specific embodiments of the description shown in the accompanying drawings. For a better understanding, like elements are designated by like reference numerals throughout the various accompanying drawings. Some of the drawings may be schematic or exaggerated representations of concepts, but at least some of the drawings can be drawn to scale. Understanding that the drawings illustrate several example embodiments, those embodiments will be described and explained with further particularity and detail by use of the accompanying drawings.

Brief Description of the Drawings

[0011]

Figure 1

[0009] A schematic representation of a liquid immersion cooling system.

Figure 2

[0010] A perspective view of a heat block for use in a liquid immersion cooling system according to at least some embodiments of the present disclosure.

Figure 3

[0011] A perspective view of a computing device having a plurality of heat blocks of FIG. 2 for use in a liquid immersion cooling system according to at least some embodiments of the present disclosure.

Figure 4

[0012] A front detailed view of the computing device and heat block of FIG. 3 according to at least some embodiments of the present disclosure.

Figure 5

[0013] A schematic side view of a liquid immersion cooling system having a plurality of heat blocks according to at least some embodiments of the present disclosure.

Figure 6

[0014] A schematic side view of a heat block in fluid communication with an external tank according to at least some embodiments of the present disclosure.

Figure 7-1

[0015] A schematic side view of a heat block having a fail - safe mechanism before use according to at least some embodiments of the present disclosure.

Figure 7-2

[0016] A schematic side view of the heat block of FIG. 7 - 1 having a fail - safe mechanism during use according to at least some embodiments of the present disclosure.

Figure 8

[0017] A schematic side view of a heat block having a colloidal fail - safe mechanism according to at least some embodiments of the present disclosure.

Figure 9

[0018] A schematic side view of a heat block having another fail - safe mechanism according to at least some embodiments of the present disclosure.

Figure 10

[0019] A schematic side view of a heat block having yet another fail - safe mechanism according to at least some embodiments of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0012]

[0020] The present disclosure generally relates to systems and methods for improving the cooling capacity and efficiency of a liquid immersion cooling system. More particularly, the present disclosure relates to increasing the heat capacity of a liquid immersion cooling system and improving the efficiency of fluid movement within the system. In some embodiments, the liquid immersion cooling system cools a computing device or system that includes heat generating components. The heat generating components are immersed in a cooling fluid, which absorbs heat from the heat generating components to cool the heat generating components. In a two-phase liquid immersion cooling system, the cooling fluid can vaporize. The latent heat of evaporation, combined with the efficient removal of the hot vapor by buoyancy within the liquid cooling fluid, enables very efficient removal of heat from the computing device. The vapor then passes through a condenser, which cools the vapor cooling fluid, condenses the cooling fluid, and returns the cooling fluid to the liquid immersion chamber in the liquid phase.

[0013]

[0021] A temporary increase in the operating load of a heat generating component can cause a temperature spike in the surrounding cooling fluid. Additionally, a power outage can cause the cooling fluid to begin to rapidly vaporize, increasing the pressure and temperature within the system and posing a risk of damage to the computing devices within the liquid immersion cooling system. Liquid immersion cooling systems include a backup power source, such as a generator, to support the condenser and other cooling systems, but the additional heat ride-through capacity of those systems can bridge the time gap before those systems can respond to a power outage. Further, an increase in heat ride-through capacity can enable temporary overclocking or overvoltage of heat generating components without burdening the ability of the liquid immersion cooling system to condense the vaporized cooling fluid.

[0014]

[0022] In some immersion cooling systems according to the present disclosure, a hot block is positioned within the immersion cooling system to replace a portion of the cooling fluid with a thermal mass having a higher specific heat than the cooling fluid, to smooth out temperature variations within the cooling fluid. In some embodiments, the hot block has one or more fluid management features that direct and / or control the flow of the cooling fluid across or through the hot block. The fluid management features can direct the liquid cooling fluid to one or more heat generating components of the computing device. The fluid management features can direct the vapor cooling fluid away from one or more heat generating components of the computing device.

[0015]

[0023] In some embodiments, the fluid management features include channels formed on the surface of the hot block. For example, the fluid management channels can direct vapor bubbles away from the heat generating components while also promoting the displacement of the vapor bubbles to draw the liquid cooling fluid from the hot block or the cooler region of the computing device towards the heat generating components. In some embodiments, the fluid management channels can capture the vapor bubbles and direct them towards the condenser or from the vapor conduit towards the condenser to more efficiently collect and condense the vaporized cooling fluid.

[0016]

[0024] The immersion cooling system, in some embodiments, has a fluid management feature including a fluid port passing through at least a portion of the hot block to direct the flow of the cooling fluid to the heat generating components. For example, a fluid conduit (e.g., a hose) can connect the inlet port of the hot block to the liquid return port from the condenser of the immersion cooling system. In some embodiments, the fluid management feature of the hot block connects the inlet port to an outlet port adjacent to and / or proximate to the heat generating components to direct the most recently condensed and cooled liquid cooling fluid to the heat generating components.

[0017]

[0025] In some embodiments, the heat block according to the present disclosure includes an emergency cooling fail-safe. In some embodiments, the fail-safe is a single-use consumable device, while in other embodiments, the fail-safe is resettable and / or reusable. The emergency cooling fail-safe is, according to the present disclosure, a mechanism for generating an endothermic reaction, thereby absorbing heat from the cooling fluid to cool the heat-generating component and limit or prevent dry-out before the heat-generating component is damaged. For example, the heat block can include two chemical reaction materials that generate an endothermic reaction when exposed to each other. The two chemical reaction materials can be separated from each other by a temperature-sensitive membrane. In some embodiments, when the membrane exceeds its rupture temperature, the membrane deteriorates, allowing the two chemical reaction materials to mix and / or react with each other.

[0018]

[0026] Referring now to FIG. 1, a liquid immersion cooling system 100 according to the present disclosure includes a chamber 102 having a cooling fluid 104 positioned therein. A condenser 106 is positioned above the cooling fluid 104 and within the vapor 110 of the cooling fluid 104 above the liquid cooling fluid 108. The condenser 106 cools a portion of the vapor 110 of the cooling fluid 104 to return it to the liquid phase, removes thermal energy from the system, and reintroduces the cooling fluid 104 into the liquid bath 112 of the liquid cooling fluid 108.

[0019]

[0027] In some embodiments, the liquid bath 112 of the liquid cooling fluid 108 has a plurality of heat-generating components 114 positioned within the liquid cooling fluid 108. The liquid cooling fluid 108 surrounds the heat-generating components 114 and can surround other objects or components attached to the heat-generating components 114.

[0020]

[0028] As described, the conversion of the liquid cooling fluid 108 to its vapor phase 116 requires an input of thermal energy to overcome the latent heat of vaporization and can be an effective mechanism for increasing the heat capacity of the cooling fluid and removing heat from the heat-generating components 114.

[0021]

[0029] The cooling fluid transitions between a liquid phase and a gas phase to remove heat from hot or heat - generating components within the chamber. The liquid phase more efficiently stores heat from the components, and when transitioning to the gas phase, the cooling fluid can be cooled and condensed to remove heat from the cooling fluid before returning to the low - temperature immersion bath.

[0022]

[0030] In some embodiments, the immersion bath of the liquid cooling fluid 108 has a plurality of heat - generating components 114 positioned within the liquid cooling fluid 108. The liquid cooling fluid 108 surrounds the heat - generating components 114 and other objects or parts attached to the heat - generating components 114. In some embodiments, one or more of the heat - generating components 114 include a heat sink or other devices attached to the heat - generating components 114 that dissipate heat energy and effectively increase the surface area of the heat - generating components 114.

[0023]

[0031] Since the gas phase 116 occurs within the liquid cooling fluid 108, it can be removed from the immersion chamber 102 in the upper vapor region 110 of the chamber 102. The condenser 106 cools a portion of the vapor of the cooling fluid 104 to return it to the liquid phase, removes heat energy from the system, and re - introduces the cooling fluid into the immersion bath 112 of the liquid cooling fluid 108. The condenser 106 dumps the heat energy from the cooling fluid 104 to the surrounding environment or into a conduit by radiation or other means to carry away the heat energy from the cooling system 100.

[0024]

[0032] In some embodiments, the cooling fluid stores heat within a cooling volume of the cooling fluid that directly surrounds the heat - generating component. The cooling volume is the region of the cooling fluid (including both the liquid and gas phases) that directly surrounds the heat - generating component and is responsible for convective cooling of the heat - generating component. In some embodiments, the cooling volume is the volume of the cooling fluid within 5 millimeters (mm) of the heat - generating component.

[0025]

[0033] The cooling fluid has a boiling temperature lower than the critical temperature at which the heat - generating component experiences thermal damage. For example, the heat - generating component can be a computing component that experiences damage when exceeding 100 degrees Celsius (°C). In some embodiments, the boiling temperature of the cooling fluid is lower than the critical temperature of the heat - generating component. In some embodiments, the boiling temperature of the cooling fluid is lower than about 90°C, lower than about 80°C, lower than about 70°C, or lower than about 60°C. In some embodiments, the boiling temperature of the cooling fluid is at least about 35°C. In some embodiments, the cooling fluid includes water, glycol, or a combination of water and glycol. In some embodiments, the cooling fluid is an aqueous solution. In some embodiments, the cooling fluid is an electrical fluid such as FC - 72 available from 3M or a similar non - conductive fluid. The heat - generating component, the immersion tank surface, and other elements of the immersion cooling system positioned within the cooling fluid can have nucleation sites on their surfaces, and the nucleation sites promote the nucleation of vapor bubbles in the cooling fluid at or below the boiling temperature of the cooling fluid.

[0026]

[0034] Large immersion cooling systems require that a portion of the immersion tank volume be cooling fluid outside the cooling volume, and thus, the heat - generating components are inefficiently cooled. In some embodiments, not all components of a computing device generate enough heat to require immersion cooling in order to stay within a safe operating temperature range. In some embodiments, a graphical processing unit (GPU) generates more heat than a platter - based storage device, and ambient air cooling is sufficient to cool the storage device rather than the GPU.

[0027]

[0035] The heat block according to the present disclosure has, in some embodiments, an inner surface that faces a computing device or other heat-generating component shaped to approximate the shape of a computing device. In some embodiments, the inner surface is shaped to complementarily fit the topology of the computing device. For example, the inner surface of the heat block can be formed to follow the surface of the heat-generating component of the computing device, such that the inner surface is between at least two of the heat-generating components at 5 millimeters (mm) to 10 mm. In some embodiments, the inner surface of the heat block can be formed to be positioned within 5 to 10 mm of the entire surface of the computing device. The close placement of the heat block relative to the heat-generating component allows for efficient transfer of heat to the heat block, however, a certain amount of space is maintained between the two to allow for fluid flow and the expulsion of vapor bubbles.

[0028]

[0036] In some embodiments, the heat block has at least one channel positioned on an inner surface that is recessed outwardly from the computing device. The heat block can have a single channel that facilitates a high rate of fluid movement through the portion of the heat block that includes the channel. The heat block can include a plurality of channels to diffuse the vapor cooling fluid over a larger area of the computing device and / or to remove the vapor cooling fluid from the computing device to limit and / or prevent dryout. In some embodiments, the channel has a depth relative to the surface of the computing device that varies along the length of the channel. For example, the channel can have a depth that increases along the length of the channel to allow for the removal of vapor, which occupies a larger volume than the liquid cooling fluid and forms a majority of the cooling fluid as the vapor bubbles rise along the length of the channel.

[0029]

[0037] The hot block has, in some embodiments, a vapor outlet formed at an end of the block that collects and directs vapor bubbles toward a vapor collection device. Since the vapor bubbles flow upward through the channel and out of the vapor outlet, the vapor bubbles can create a risk of dryout for components positioned on top of the hot block (e.g., in the direction of the buoyancy of the cooling fluid). In some embodiments, the hot block has a vapor outlet formed at an end of the block that directs vapor bubbles outward from a second hot block or a second computing device in the direction of the bubble flow.

[0030]

[0038] FIG. 2 is a perspective view of one embodiment of a hot block 218. The hot block 218 has an inner surface 220 for housing heat generating components, and the inner surface 220 has a recess 222 therein. The recess 222 has a channel 224 that is further recessed from the inner surface 220. The channel 224 provides a flow path from a lower intake portion 226 of the hot block 218 to a vapor outlet 228 at the top of the hot block 218. The inner surface 220 of the recess 222 is positioned closer to the surface of the heat generating components to accommodate heat from the heat generating components, while the channel 224 facilitates fluid flow through the hot block 218 and draws fluid across the heat generating components.

[0031]

[0039] FIG. 3 is a perspective view of an embodiment of the hot block 218 of FIG. 2 connected to a computing device 230. The computing device 230 has a plurality of heat generating components thereon, and individual hot blocks 218-1, 218-2 are positioned on a board 232 of the computing device 230 to accommodate heat from heat generating components 214-1, 214-2 and direct cooling fluid across the heat generating components 214-1, 214-2.

[0032]

[0040] In some embodiments, the steam outlets 228 of the heat blocks 218-1, 218-2 are spaced apart from the board 232, such that steam bubbles discharged from the heat blocks 218-1, 218-2 are directed outwardly from other components of the computing device, such as the heat sink 234 shown in FIG. 3, on the first heat block 218-1.

[0033]

[0041] In some embodiments, at least one of the heat blocks 218-1, 218-2 includes a fiducial mark 235 on an outer surface of the heat blocks 218-1, 218-2, and the fiducial mark 235 is identifiable by a machine vision system for positioning and / or orienting the heat blocks 218-1, 218-2 and / or the computing device 230 within a server rack or a liquid immersion cooling system.

[0034]

[0042] FIG. 4 is a front detailed view of the computing device 230 of FIG. 3. The first heat block 218-1 is connected to the board 232 and positioned on the first heat generating component 214-1. The recess 222 is complementary in shape to the first heat generating component 214-1, the channel 224 directs a liquid cooling fluid flow across the first heat generating component 214-1, while the steam outlet 228 is positioned over the first heat generating component 214-1 to discharge steam bubbles.

[0035]

[0043] The heat block is connected to a support within the immersion tank and can hold the heat block against the computing device. In some embodiments, the heat block is affixed to the computing device to hold the heat block against the computing device. In some embodiments, each type of heat block has a unique configuration of mounting points for each type of computing device, and a heat block having an inner surface configured to fit the first computing device is prevented from being inaccurately affixed to the second computing device (which could damage components of the second computing device), limiting the risk.

[0036]

[0044] In some embodiments, the computing device is oriented with the board vertical within the immersion tank and / or mounted in a server rack. The heat block can be affixed to the board with the channels vertically oriented. In some embodiments, the channels or other fluid management features are oriented horizontally or diagonally to direct the cooling fluid across the surface of the computing device. In some embodiments, at least a portion of the channels or other fluid management features are curved to direct the cooling fluid across the surface of the computing device.

[0037]

[0045] In some embodiments, the heat block is positioned over a single heat-generating component of the computing device. For example, the heat block can be sized to fit over and / or affixed to a processor such as a GPU or CPU; a memory device such as solid-state memory or platen-based memory; a power supply; a network switch or other communication module; or other heat-generating components. In other embodiments, the heat block can be sized to fit over and / or affixed to the entire computing device such that it has an area approximately the same as or larger than the board of the computing device.

[0038]

[0046] FIG. 5 is a schematic side view of an embodiment of a liquid immersion cooling system 300 according to the present disclosure. In some embodiments, the liquid immersion cooling system has a plurality of identical computing devices 330-1, 330-2, 330-3 and associated heat blocks 318-1, 318-2, 318-3. In some embodiments, the computing devices and / or heat blocks vary within the liquid immersion cooling system 300.

[0039]

[0047] The first heat block 318-1 is positioned proximate to the first computing device 330-1. The first heat block 318-1 has a first inner surface 320-1 that is complementary in shape to the topology of the heat generating component 314-1 of the first computing device 330-1. For example, the surface of the first computing device 330-1 that faces towards the first heat block 318-1 is the block surface of the first computing device 330-1. The block surface is defined by the board and the heat generating component 314-1 of the first computing device 330-1. The contour shape of the board and the heat generating component 314-1 of the first computing device 330-1 defines the topography of the first computing device 330-1. The first inner surface 320-1 is shaped to maintain a gap between the heat generating component 314-1 and the first inner surface 320-1 between 5 mm and 10 mm. In some embodiments, the vapor bubbles 316 flow upward through the gap 334 and carry heat towards the condenser 306.

[0040]

[0048] In some embodiments, a heat block configured to fit a plurality of heat generating components of a computing device is also configured to complementarily fit the topology of the components (e.g., heat generating components) of the computing device. The inner surface of the heat block can be at least 2 mm from the surface of the component. Proximate and / or adjacent to the heat generating component, the inner surface of the heat block can be between 5 mm and 10 mm from the surface of the heat generating component to provide clearance for vapor bubbles to pass between the heat generating components.

[0041]

[0049] The heat block, in some instances, includes at least one fluid port internally to direct liquid cooling fluid to or near one or more heat generating components. In some embodiments, the fluid port is an outlet portion of a conduit passing through the interior of the heat block. The conduit provides fluid communication from an inlet port to the outlet port(s). In some embodiments, the inlet port is connected to a liquid cooling fluid return line from a condenser. The condenser of the immersion cooling system removes heat from the vapor cooling fluid within the immersion tank.

[0042]

[0050] After condensing the vapor cooling fluid to return it to a liquid cooling fluid, the returned liquid cooling fluid can be at a lower temperature than the immersion tank and / or the heat block. Thus, connecting the liquid cooling fluid return line can direct the coldest cooling fluid to the heat generating components that require maximum heat management. In some embodiments, the outlet port can accelerate the flow of the cooling fluid provided by the liquid cooling fluid return line from the condenser, further increasing the convective cooling of the liquid cooling fluid by increasing the flow of the cooling fluid onto the heat generating components.

[0043]

[0051] FIG. 5 further shows a second heat block 318-2 proximate to the second computing device 330-2. The second heat block 318-2 includes a conduit 336 having an outlet port 338 and an inlet port 340. The inlet port 340 is connected to a liquid cooling fluid return line 343 from the condenser 306. The cold liquid cooling fluid flows into the conduit 336 from the liquid cooling fluid return line 343. The conduit 336 directs a jet of cooling fluid directly onto the heat generating component 314-2 of the second computing device 330-2, providing enhanced cooling to the heat generating component 314-2.

[0044]

[0052] In some embodiments, the heat block is a container that holds a second material therein. The heat block can be made of or include any thermally conductive material, such as a polymer like high density polyethylene or a metal such as aluminum or copper.

[0045]

[0053] In some embodiments, the second material is a phase change material having a melting point higher than the boiling point of the liquid cooling fluid of the liquid immersion cooling system. In some examples, the second material is coconut oil, paraffin wax, olefin, or some other oil or wax having a melting temperature close to the boiling temperature of the cooling fluid. A second material having a melting temperature higher than the cooling fluid boiling temperature allows the second material to remain in a solid phase as long as the cooling fluid efficiently removes heat from the heat generating component. In the case of dry out conditions, condenser failure, or a surge in heat generation (such as overclocking or overvoltage of components of the computing device), the second material can melt, providing a secondary two-phase cooling system.

[0046]

[0054] In some embodiments, the second material has a melting temperature lower than the boiling temperature of the liquid cooling fluid of the immersion cooling system. The second material having a lower melting temperature can help maintain the hot block surface at a lower temperature and reduce vapor bubble formation adjacent to the hot block near the sensitive components of the computing device.

[0047]

[0055] The second material can be a phase change fluid. In some embodiments, the second fluid has a boiling temperature higher than the boiling temperature of the liquid cooling fluid of the immersion cooling system. The second fluid having a higher boiling temperature allows the second fluid to remain in the liquid phase as long as the cooling fluid efficiently removes heat from the heat generating component. In the case of dry-out conditions, condenser failure, or a surge in heat generation (such as overclocking or overvoltage of components of the computing device), the second fluid can vaporize, providing a secondary two-phase cooling system. In some embodiments, the second fluid has a boiling temperature lower than the liquid cooling fluid of the immersion cooling system. The second fluid having a lower boiling temperature can help maintain the hot block surface at a lower temperature and reduce vapor bubble formation adjacent to the hot block near the sensitive components of the computing device.

[0048]

[0056] Referring again to FIG. 5, the third hot block 318-3 is positioned proximate to the third computing device 330-3. The third hot block 318-3 includes a second material 342 within its internal volume 344. The internal volume 344 is in fluid communication with an expansion tank 346 that allows the second material 342 to expand by heating and / or phase change.

[0049]

[0057] In some embodiments, the density of the hot block renders the hot block neutrally buoyant within the cooling fluid. In some embodiments, the hot block is in a positive or negative buoyancy state within the cooling fluid. In some embodiments, the mass of the hot block varies by a second fluid contained within the internal volume. The hot block can vary between a positive buoyancy state and a negative buoyancy state.

[0050]

[0058] The hot block having a second fluid therein can be a closed system having a plurality of tanks in fluid communication with an internal chamber of the hot block. The internal chamber holds a portion of the second fluid. The pressure and / or mass of the second fluid can be adjusted through a controlled pressure within an accumulator tank. The accumulator tank can feed into the internal volume of the hot block to control the pressure of the second fluid within the hot block. In some embodiments, the internal volume is in further fluid communication with an expansion tank, and the expansion tank allows for expansion of the second fluid exiting the internal volume when the second fluid expands or vaporizes.

[0051]

[0059] FIG. 6 is a side schematic view of one embodiment of a hot block 418 in fluid communication with an accumulator tank 448 and an expansion tank 446. A second material 442 within an internal volume 444 of the hot block 418 is held under pressure by the accumulator tank 448. In some embodiments, the accumulator tank 448 allows for an adjustable head pressure to be delivered to the internal volume of the hot block 418. The expansion tank 446 can prevent damage to the hot block 418 and / or the accumulator tank 448 when the second material 442 expands.

[0052]

[0060] In some embodiments, the hot block includes an emergency fail-safe mechanism. In some embodiments, the fail-safe mechanism is a single-use mechanism that is consumed during use. The hot block must be replaced in order to make the fail-safe mechanism reusable. In some embodiments, the fail-safe mechanism can be reset or reused multiple times within the same hot block.

[0053]

[0061] In some embodiments, the hot block has an internal volume having two materials separated by a membrane. The two materials are chemical reaction materials. In some embodiments, the chemical reaction materials undergo an endothermic reaction that absorbs heat when mixed with each other. For example, the hot block can include a second fluid and a third fluid, where the second fluid is contained in a first chamber and the third fluid is contained in a second chamber. In other examples, the hot block can include fluids and solids that chemically react with each other. In yet other examples, a third material, such as a catalyst, can be present in the internal volume of the hot block.

[0054]

[0062] The membrane is, in some embodiments, temperature-sensitive and will degrade when exposed to a threshold temperature. The threshold temperature is higher than the boiling temperature of the cooling fluid. Thus, the membrane remains intact during normal operation. If the hot block begins to heat above the boiling temperature of the cooling fluid, the membrane can degrade, enabling the chemical reaction materials to react.

[0055]

[0063] Figures 7-1 and 7-2 show an embodiment of a hot block 518 having a first chamber 550 and a second chamber 552 that contain a second material 542 and a third material 554 that chemically reacts with the second material 542. In some embodiments, the first chamber 550 and the second chamber 552 have the same volume. In some embodiments, the first chamber 550 and the second chamber 552 have different volumes, with one volume being larger than the other. The first chamber 550 and the second chamber 552 are separated by a membrane 556 that can rupture or otherwise degrade to a point where the second material 542 and the third material 554 can contact and react with each other, as shown in Figure 7-2.

[0056]

[0064] The chemically reactive materials can be separated in two chambers or in multiple chambers, such as in a colloidal distribution state. In some embodiments, the third material is contained within a plurality of individual membranes suspended within the second fluid. The membranes encapsulating the third material are temperature-sensitive membranes that can degrade and / or rupture when the second fluid exceeds a threshold temperature. The plurality of individual membranes allow for faster mixing and reaction between the chemically reactive materials and can cool the hot block faster than a single membrane that divides the internal volume into two chambers.

[0057]

[0065] Figure 8 is a schematic diagram of a hot block 618 having a first chamber 650 therein. In some embodiments, the first chamber 650 contains the second material 642 described herein. A plurality of spherical (or otherwise shaped) membranes 656 are positioned within the second fluid 642 and contain a third material 654. In some embodiments, the membranes 656 are made of and / or include a temperature-sensitive material that can rupture or otherwise degrade to a point where the second fluid 642 and the third material 654 can contact and react with each other.

[0058]

[0066] In some embodiments, the hot block has one or more features that slow the mixing and / or reaction of the chemical reaction materials. For example, the different membranes can include different materials having different threshold temperatures. If the first chamber breaks and the third material therein undergoes an endothermic reaction with the second fluid and the temperature continues to rise, another chamber can break and allow another mass of the third material to undergo an endothermic reaction with the second fluid. In some embodiments, the first chamber and the second chamber have different thicknesses to delay the mixing of the third material in the second chamber with the second fluid.

[0059]

[0067] FIG. 9 is a schematic diagram of a hot block 718 having a first chamber 750 therein. In some embodiments, the first chamber 750 contains the second fluid 742 described herein. A plurality of spherical (or otherwise shaped) membranes 756-1, 756-2 are positioned within the second fluid 742 and contain a third material 754. In some embodiments, the membranes 756 are made of and / or include a temperature-sensitive material that can break or otherwise degrade to a point where the second fluid 742 and the third material 754 can contact and react with each other. In contrast to the embodiment described with respect to FIG. 8, the first membrane 756-1 and the second membrane 756-2 have different thicknesses. The second membrane 756-2 requires more time and / or more heat to degrade and break, resulting in a longer release period of the third material 754 into the second fluid 742.

[0060]

[0068] In some embodiments, the third material is a solid material at the threshold temperature of the membrane. When the membrane breaks, the endothermic reaction between the second fluid and the third material is slow due to the limited surface area of the solid third material.

[0061]

[0069] FIG. 10 is a schematic diagram of a hot block 818 having a first chamber 850 therein. In some embodiments, the first chamber 850 contains a second fluid 842 as described herein. A plurality of spherical (or otherwise shaped) membranes 856 are positioned within the second fluid 842 and contain a third material 854. In some embodiments, the membrane 856 is a coating on a solid third material 854. When the coating deteriorates sufficiently, the solid third material 854 can react with the second fluid 842. Since the endothermic reaction is limited by the surface area of the solid third material 854, the reaction can be slow and / or not aggressive compared to other examples described herein.

Industrial Applicability

[0062]

[0070] The present disclosure generally relates to systems and methods for improving the cooling capacity and efficiency of liquid immersion cooling systems. More particularly, the present disclosure relates to increasing the heat capacity of a liquid immersion cooling system and improving the efficiency of fluid movement within the system. In some embodiments, a liquid immersion cooling system cools a computing device or system that includes heat generating components. The heat generating components are immersed in a cooling fluid, which absorbs heat from the heat generating components to cool the heat generating components. In a two-phase liquid immersion cooling system, the cooling fluid can vaporize. The latent heat of evaporation, combined with the efficient removal of the hot vapor by buoyancy within the liquid cooling fluid, enables very efficient removal of heat from the computing device. The vapor then passes through a condenser, which cools the vapor cooling fluid, condenses the cooling fluid, and returns the cooling fluid to the liquid phase in the immersion chamber.

[0063]

[0071] A temporary increase in the operating load of the heat - generating component can cause a temperature spike in the surrounding cooling fluid. Further, a power outage can cause the cooling fluid to start rapidly vaporizing, increasing the pressure and temperature within the system and posing a risk of damage to the computing devices within the liquid - immersion cooling system. Liquid - immersion cooling systems include a backup power source, such as a generator, to support the condenser and other cooling systems, but the additional thermal ride - through capacity of the liquid - immersion cooling system can bridge the time gap before those systems can respond to a power outage. Further, an increase in the thermal ride - through capacity can enable temporary overclocking or overvoltage of the heat - generating component without overburdening the ability of the liquid - immersion cooling system to condense the vaporized cooling fluid.

[0064]

[0072] In some liquid - immersion cooling systems according to the present disclosure, the heat block is positioned within the liquid - immersion cooling system to replace a portion of the cooling fluid with a thermal mass having a specific heat higher than that of the cooling fluid, to smooth out temperature variations within the cooling fluid. In some embodiments, the heat block has one or more fluid management features that direct and / or control the flow of the cooling fluid across or through the heat block. The fluid management features can direct the liquid cooling fluid to one or more heat - generating components of the computing device. The fluid management features can direct the vapor cooling fluid away from one or more heat - generating components of the computing device.

[0065]

[0073] In some embodiments, the fluid management feature includes channels formed on the surface of the heat block. For example, the fluid management channels can direct vapor bubbles away from the heat generating component while also promoting the displacement of the vapor bubbles to draw the liquid cooling fluid from the heat block or the cooler region of the computing device towards the heat generating component. In some embodiments, the fluid management channels capture the vapor bubbles and direct them towards the condenser or from the vapor conduit towards the condenser to more efficiently collect and condense the vaporized cooling fluid.

[0066]

[0074] The liquid immersion cooling system, in some embodiments, has a fluid management feature including a fluid port passing through at least a portion of the heat block to direct the flow of the cooling fluid towards the heat generating component. For example, a fluid conduit (e.g., a hose) can connect the inlet port of the heat block to the liquid return port from the condenser of the liquid immersion cooling system. In some embodiments, the fluid management feature of the heat block connects the inlet port to an outlet port adjacent to and / or proximate to the heat generating component to direct the most recently condensed and cooled liquid cooling fluid towards the heat generating component.

[0067]

[0075] In some embodiments, the heat block according to the present disclosure includes an emergency cooling fail-safe. In some embodiments, the fail-safe is a single-use consumable device, while in other embodiments, the fail-safe is resettable and / or reusable. The emergency cooling fail-safe, according to the present disclosure, is a mechanism for generating an endothermic reaction, thereby absorbing heat from the cooling fluid to cool the heat-generating component before the heat-generating component is damaged and limiting or preventing dry-out. For example, the heat block can include two chemical reaction materials that generate an endothermic reaction when exposed to each other. The two chemical reaction materials can be separated from each other by a temperature-sensitive membrane. In some embodiments, when the membrane exceeds its rupture temperature, the membrane deteriorates, allowing the two chemical reaction materials to mix and / or react with each other.

[0068]

[0076] The liquid immersion cooling system according to the present disclosure includes a chamber having a cooling fluid positioned therein. A condenser is positioned above the cooling fluid and within the vapor of the cooling fluid above the liquid cooling fluid. The condenser cools a portion of the vapor of the cooling fluid to return it to the liquid phase, removes thermal energy from the system, and reintroduces the cooling fluid into the liquid immersion bath of the liquid cooling fluid.

[0069]

[0077] In some embodiments, the liquid immersion bath of the liquid cooling fluid has a plurality of heat-generating components positioned within the liquid cooling fluid 108. The liquid cooling fluid can surround the heat-generating components and other objects or components attached to the heat-generating components.

[0070]

[0078] As described, the conversion of the liquid cooling fluid to the gas phase requires an input of thermal energy to overcome the latent heat of vaporization and can be an effective mechanism for increasing the heat capacity of the cooling fluid and removing heat from the heat-generating components.

[0071]

[0079] The cooling fluid transitions between a liquid phase and a gas phase to remove heat from hot or heat - generating components within the chamber. The liquid phase more efficiently stores the heat from the components, and when transitioning to the gas phase, the cooling fluid can be cooled and condensed to remove heat from the cooling fluid before returning to the low - temperature immersion bath.

[0072]

[0080] In some embodiments, the immersion bath of the liquid cooling fluid has a plurality of heat - generating components positioned within the liquid cooling fluid. The liquid cooling fluid surrounds the heat - generating components and other objects or parts attached to the heat - generating components. In some embodiments, one or more of the heat - generating components include a heat sink or other devices attached to the heat - generating components that extract thermal energy and effectively increase the surface area of the heat - generating components.

[0073]

[0081] Since the gas phase is generated within the liquid cooling fluid, it can be removed from the immersion chamber in the upper vapor region of the chamber. The condenser cools a portion of the vapor of the cooling fluid back to the liquid phase, removes thermal energy from the system, and re - introduces the cooling fluid into the immersion bath of the liquid cooling fluid. The condenser dumps the thermal energy from the cooling fluid to the surrounding environment or into a conduit by radiation or other means to carry away the thermal energy from the cooling system.

[0074]

[0082] In some embodiments, the cooling fluid stores heat within a cooling volume of the cooling fluid that directly surrounds the heat - generating component. The cooling volume is the region of the cooling fluid (including both the liquid and gas phases) that directly surrounds the heat - generating component and is responsible for the convective cooling of the heat - generating component. In some embodiments, the cooling volume is the volume of the cooling fluid within 5 millimeters (mm) of the heat - generating component.

[0075]

[0083] The cooling fluid has a boiling temperature lower than the critical temperature at which the heat-generating component experiences thermal damage. For example, the heat-generating component can be a computing device that experiences damage when exceeding 100 degrees Celsius (°C). In some embodiments, the boiling temperature of the cooling fluid is lower than the critical temperature of the heat-generating component. In some embodiments, the boiling temperature of the cooling fluid is lower than about 90 °C, lower than about 80 °C, lower than about 70 °C, or lower than about 60 °C. In some embodiments, the boiling temperature of the cooling fluid is at least about 35 °C. In some embodiments, the cooling fluid includes water, glycol, or a combination of water and glycol. In some embodiments, the cooling fluid is an aqueous solution. In some embodiments, the cooling fluid is an electrical fluid such as FC-72 available from 3M or a similar non-conductive fluid. The heat-generating component, the surface of the immersion tank, and other elements of the immersion cooling system positioned within the cooling fluid can have nucleation sites on their surfaces, and the nucleation sites promote the nucleation of vapor bubbles of the cooling fluid at or below the boiling temperature of the cooling fluid.

[0076]

[0084] Large immersion cooling systems require that a portion of the immersion tank volume be cooling fluid outside the cooling volume, and thus the heat-generating component is inefficiently cooled. In some embodiments, not all components of the computing device generate enough heat to require immersion cooling in order to remain within a safe operating temperature range. In some embodiments, a graphical processing unit (GPU) generates more heat than a platter-based storage device, and ambient air cooling is sufficient to cool the storage device rather than the GPU.

[0077]

[0085] The heat block according to the present disclosure has, in some embodiments, an inner surface that faces towards a computing device or another heat generating component that is shaped to approximate the shape of a computing device. In some embodiments, the inner surface is shaped to complementarily fit the topology of the computing device. For example, the inner surface of the heat block can be formed to follow the surface of the heat generating component of the computing device, whereby the inner surface is between at least two of the heat generating components at 5 millimeters (mm) to 10 mm. In some embodiments, the inner surface of the heat block can be formed to be positioned within 5 to 10 mm of the entire surface of the computing device. The close placement of the heat block relative to the heat generating component allows for efficient transfer of heat to the heat block, however, a certain amount of space is maintained between them to allow for fluid flow and the expulsion of vapor bubbles.

[0078]

[0086] In some embodiments, the heat block has at least one channel positioned on an inner surface that is recessed outwardly from the computing device. The heat block can have a single channel that facilitates a high rate of fluid movement through the portion of the heat block that includes the channel. The heat block can include a plurality of channels to diffuse the vapor cooling fluid over a larger area of the computing device and / or to remove the vapor cooling fluid from the computing device to limit and / or prevent dryout. In some embodiments, the channel has a depth relative to the surface of the computing device that varies along the length of the channel. For example, the channel can have a depth that increases along the length of the channel to allow for the removal of vapor, which occupies a larger volume than the liquid cooling fluid and forms the majority of the cooling fluid as the vapor bubbles rise along the length of the channel.

[0079]

[0087] The hot block has, in some embodiments, a vapor outlet formed at an end of the block that collects and directs vapor bubbles toward a vapor collection device. Since the vapor bubbles flow upward through the channel and out of the vapor outlet, the vapor bubbles can create a risk of dryout for components positioned on top of the hot block (e.g., in the direction of the buoyancy of the cooling fluid). In some embodiments, the hot block has a vapor outlet formed at an end of the block that directs vapor bubbles outward from a second hot block or a second computing device in the direction of the bubble flow.

[0080]

[0088] The hot block can be connected to a support within the immersion tank to hold the hot block relative to the computing device. In some embodiments, the hot block is affixed to the computing device to hold the hot block relative to the computing device. In some embodiments, each type of hot block has a unique configuration of mounting points for each type of computing device, and a hot block having an inner surface configured to fit a first computing device is not improperly affixed to a second computing device (which could damage components of the second computing device), limiting the risk.

[0081]

[0089] In some embodiments, the computing device is oriented with the board vertical within the immersion tank and / or mounted in a server rack. The hot block can be affixed to the board with the channel vertically oriented. In some embodiments, the channel or other fluid management feature is oriented horizontally or obliquely to direct the cooling fluid across the surface of the computing device. In some embodiments, at least a portion of the channel or other fluid management feature is curved to direct the cooling fluid across the surface of the computing device.

[0082]

[0090] In some embodiments, the heat block includes a fiducial mark on an outer surface of the heat block, and the fiducial mark is identifiable by a machine vision system for positioning and / or orienting the heat block and / or computing device within a server rack or liquid immersion cooling system.

[0083]

[0091] In some embodiments, the heat block is positioned on a single heat generating component of a computing device. For example, the heat block can be sized to fit over and / or be affixed to a processor such as a GPU or CPU; a memory device such as solid state memory or platen-based memory; a power supply; a network switch or other communication module; or other heat generating components. In other embodiments, the heat block can be sized to fit over and / or be affixed to the entire computing device such that the heat block has an area that is approximately the same as or larger than the board of the computing device.

[0084]

[0092] In some embodiments, a heat block configured to fit over a plurality of heat generating components of a computing device is also configured to complementarily mate to the topology of the components (e.g., heat generating components) of the computing device. The inner surface of the heat block can be at least 2 mm from the surface of the component. Proximate and / or adjacent to the heat generating components, the inner surface of the heat block can be between 5 mm and 10 mm from the surface of the heat generating components to provide clearance for vapor bubbles to pass between the heat generating components.

[0085]

[0093] The hot block can, in some instances, include at least one fluid port internally to direct liquid cooling fluid to or near one or more heat generating components. In some embodiments, the fluid port is an outlet portion of a conduit passing through the interior of the hot block. The conduit provides fluid communication from an inlet port to the outlet port(s). In some embodiments, the inlet port is connected to a liquid cooling fluid return line from a condenser. The condenser of the immersion cooling system removes heat from the vapor cooling fluid within the immersion tank.

[0086]

[0094] After condensing the vapor cooling fluid back to a liquid cooling fluid, the returned liquid cooling fluid can be at a lower temperature than the immersion tank and / or the hot block. Thus, connecting the liquid cooling fluid return line can direct the coldest cooling fluid to the heat generating components that require maximum thermal management. In some embodiments, the outlet port can accelerate the flow of the cooling fluid provided by the liquid cooling fluid return line from the condenser, further increasing the convective cooling of the liquid cooling fluid by increasing the flow of the cooling fluid onto the heat generating component.

[0087]

[0095] In some embodiments, the hot block is a container that holds a second material therein. The outer layer of the hot block can be made of or include any thermally conductive material, such as a polymer like high density polyethylene or a metal like aluminum or copper.

[0088]

[0096] In some embodiments, the second material is a phase change material having a melting point higher than the boiling point of the liquid cooling fluid of the liquid immersion cooling system. In some examples, the second material is coconut oil, paraffin wax, olefin, or other oil or wax having a melting temperature close to the boiling temperature of the cooling fluid. The second material having a melting temperature higher than the cooling fluid boiling temperature allows the second material to remain in a solid phase as long as the cooling fluid efficiently removes heat from the heat generating component. In the case of dry-out conditions, condenser failure, or a surge in heat generation (such as overclocking or overvoltage of components of a computing device), the second material can melt and provide a secondary two-phase cooling system.

[0089]

[0097] In some embodiments, the second material has a melting temperature lower than the boiling temperature of the liquid cooling fluid of the liquid immersion cooling system. The second material having a lower melting temperature can help maintain the heat block surface at a lower temperature and reduce vapor bubble formation adjacent to the heat block near the sensitive components of the computing device.

[0090]

[0098] In some embodiments, the density of the heat block makes the heat block neutrally buoyant in the cooling fluid. In some embodiments, the heat block is in a positive or negative buoyancy state in the cooling fluid. In some embodiments, the mass of the heat block varies by a second fluid contained in the internal volume. The heat block can vary between a positive buoyancy state and a negative buoyancy state.

[0091]

[0099] The second material can be a phase change fluid. In some embodiments, the second fluid has a boiling temperature higher than the boiling temperature of the liquid cooling fluid of the liquid immersion cooling system. The second fluid having a higher boiling temperature allows the second fluid to remain in the liquid phase as long as the cooling fluid efficiently removes heat from the heat generating component. In the case of dry-out conditions, condenser failure, or a surge in heat generation (such as overclocking or overvoltage of components of a computing device), the second fluid can vaporize, providing a secondary two-phase cooling system. In some embodiments, the second fluid has a boiling temperature lower than the liquid cooling fluid of the liquid immersion cooling system. The second material having a lower boiling temperature can help maintain the heat block surface at a lower temperature and reduce vapor bubble formation adjacent to the heat block near the sensitive components of the computing device.

[0092]

[0100] The heat block having the second fluid therein can be a closed system having a plurality of tanks in fluid communication with an internal chamber of the heat block. The internal chamber holds a portion of the second fluid. The pressure and / or mass of the second fluid can be adjusted through a controlled pressure within an accumulator tank. The accumulator tank can feed into the internal volume of the heat block to control the pressure of the second fluid within the heat block. In some embodiments, the internal volume is in further fluid communication with an expansion tank, and the expansion tank allows for the expansion of the second fluid exiting the internal volume when the second fluid expands or vaporizes.

[0093]

[0101] In some embodiments, the heat block includes an emergency fail-safe mechanism. In some embodiments, the fail-safe mechanism is a single-use mechanism that is consumed during use. The heat block must be replaced in order to make the fail-safe mechanism reusable. In some embodiments, the fail-safe mechanism can be reset or reused multiple times within the same heat block.

[0094]

[0102] In some embodiments, the heat block has an internal volume having two materials separated by a membrane. The two materials are chemical reaction materials. In some embodiments, the chemical reaction materials undergo an endothermic reaction that absorbs heat when mixed with each other. For example, the heat block can include a second fluid and a third fluid, where the second fluid is contained in a first chamber and the third fluid is contained in a second chamber. In other examples, the heat block can include fluids and solids that chemically react with each other. In yet other examples, a third material, such as a catalyst, can be present in the internal volume of the heat block.

[0095]

[0103] The membrane is, in some embodiments, temperature-sensitive and will degrade when exposed to a threshold temperature. The threshold temperature is higher than the boiling temperature of the cooling fluid. Thus, the membrane remains intact during normal operation. If the heat block begins to heat above the boiling temperature of the cooling fluid, the membrane can degrade, enabling the chemical reaction materials to react.

[0096]

[0104] The chemical reaction materials can be separated in two chambers or in a plurality of chambers, such as in a colloidal distribution state. In some embodiments, the third material is contained within a plurality of individual membranes suspended within the second fluid. The membranes encapsulating the third material are temperature-sensitive membranes that can degrade and / or rupture when the second fluid exceeds the threshold temperature. The plurality of individual membranes can enable faster mixing and reaction between the chemical reaction materials and can cool the heat block faster than a single membrane that divides the internal volume into two chambers.

[0097]

[0105] In some embodiments, the hot block has one or more features that slow down the mixing and / or reaction of the chemical reaction materials. For example, the different membranes can include different materials having different threshold temperatures. If the first chamber breaks and the third material therein undergoes an endothermic reaction with the second fluid and the temperature continues to rise, another chamber can break and allow another mass of the third material to undergo an endothermic reaction with the second fluid. In some embodiments, the first chamber and the second chamber have different thicknesses to delay the mixing of the third material in the second chamber with the second fluid. In some embodiments, the third material is a solid material at the threshold temperature of the membrane. When the membrane breaks, the endothermic reaction between the second fluid and the third material is slow due to the limited surface area of the solid third material.

[0098]

[0106] The present disclosure relates to systems and methods for improving the cooling capacity and efficiency of a liquid immersion cooling system, at least by way of example provided in the following sections: 1. A thermal management system for a computing device, comprising: A liquid immersion tank having a cooling fluid filling at least a portion of the liquid immersion tank; A computing device positioned within the cooling fluid, the computing device heating the cooling fluid; A hot block positioned within the cooling fluid and configured to receive heat from the cooling fluid, the hot block including: A fluid management feature that directs the flow of the cooling fluid with respect to the hot block and the computing device.

[0099] 2. The thermal management system of section 1, wherein the hot block has at least one fluid outlet.

[0100] 3. The thermal management system of section 1, wherein the hot block is a container having a second material contained within an internal volume of the hot block.

[0101] 4. The thermal block further includes a third material, and the second material is chemically reactive with the third material, the thermal management system described in Section 3.

[0102] 5. The thermal block has an inner surface that complementarily fits at least a portion of the topology of the computing device, the thermal management system described in any one of Sections 1 - 4.

[0103] 6. The thermal block includes a plurality of fluid channels within the inner surface of the thermal block, the thermal management system described in any one of Sections 1 - 5.

[0104] 7. The fluid channels direct vapor bubbles of the cooling fluid towards the vapor collection point of the immersion tank, the thermal management system described in Section 6.

[0105] 8. The fluid channels direct the liquid cooling fluid towards the heat - generating components of the computing device, the thermal management system described in Section 6.

[0106] 9. The fluid channels direct the liquid cooling fluid from the liquid cooling fluid return line towards the heat - generating components of the computing device, the thermal management system described in Section 8.

[0107] 10. The inner surface of the thermal block is shaped complementarily to the topology of the computing device, the thermal management system described in any one of Sections 1 - 9.

[0108] 11. The inner surface of the thermal block is positioned with a gap between 2 millimeters (mm) and 10 mm between the inner surface and the block surface of the computing device, the thermal management system described in any one of Sections 1 - 10.

[0109] 12. The thermal block has a fiducial mark on the upper surface of the thermal block, and the fiducial mark is visible to a machine vision system, the thermal management system described in any one of Sections 1 - 11.

[0110] 13. A thermal management system for a computing device, comprising: A liquid immersion tank having a cooling fluid that fills at least a portion of the liquid immersion tank; and A computing device positioned within the cooling fluid and heating the cooling fluid; and A heat block positioned within the cooling fluid and configured to store heat from the cooling fluid, the heat block being a container having a second material within the container, the thermal management system.

[0111] 14. The thermal management system according to section 13, wherein the second material is a phase change material.

[0112] 15. The thermal management system according to section 13 or 14, wherein the heat block includes high density polyethylene.

[0113] 16. The thermal management system according to any one of sections 13 to 15, wherein the heat block is in a neutral buoyancy state within the cooling fluid.

[0114] 17. The thermal management system according to any one of sections 13 to 16, wherein the second material is a fluid at room temperature.

[0115] 18. A thermal management system for a computing device, comprising: A liquid immersion tank having a cooling fluid that fills at least a portion of the liquid immersion tank; and A computing device positioned within the cooling fluid and heating the cooling fluid; and A heat block positioned within the cooling fluid and configured to store heat from the cooling fluid, the heat block including a second material and a third material that are endothermically reactive with each other, the thermal management system.

[0116] 19. The second material and the third material are the thermal management system according to section 18, separated by a temperature-sensitive film in a thermal block.

[0117] 20. The third material is the thermal management system according to section 19, contained within a plurality of membranes and separated from the second material.

[0118]

[0107] It is intended that the articles "a", "an", and "the" mean that one or more of the elements exist in the preceding description. The terms "comprising", "including", and "having" are intended to be inclusive and mean that additional elements may exist other than the recited elements. Further, it should be understood that references to "one embodiment" or "an embodiment" of the present disclosure are not intended to be construed as excluding the existence of additional embodiments that also incorporate the recited features. For example, any element described in connection with an embodiment herein can be combined with any element of any other embodiment described herein. The numbers, percentages, ratios, or other values recited herein are intended to include that value, as well as other values described as "about" or "approximately" that value, as would be recognized by one of ordinary skill in the art encompassed by the embodiments of the present disclosure. Accordingly, the recited values should be construed broadly enough to include values that are at least close enough to the recited values to perform the desired function or achieve the desired result. The recited values should include at least the variations expected in a proper manufacturing or production process and can include values within 5%, 1%, 0.1%, or 0.01% of the recited values.

[0119] Those skilled in the art should recognize, in view of the present disclosure, that equivalent configurations do not depart from the scope of the present disclosure, and that various changes, substitutions, and alternatives can be made to the embodiments disclosed herein without departing from the scope of the present disclosure. Equivalent configurations including functional "means-plus-function" clauses are intended to cover the structures described herein for performing the recited functions, including both structural equivalents that operate in the same manner and equivalent structures that provide the same function. It is the intention of this application not to rely on means-plus-function or other functional claims for any claim, except where the term "means for" appears with the associated function in the claim. Each addition, deletion, and modification to an embodiment that falls within the meaning and scope of the claims is encompassed by the claims.

[0120]

[0109] It should be understood that any direction or reference frame in the foregoing description is merely a relative direction or movement. For example, any reference to "front" and "back" or "top" and "bottom" or "left" and "right" is merely a description of the relative position or movement of the associated elements.

[0121]

[0110] The present disclosure can be embodied in other specific forms without departing from its features. The embodiments described are considered to be illustrative rather than restrictive. Accordingly, the scope of the present disclosure is indicated by the appended claims rather than by the foregoing description. Changes that fall within the meaning and scope of the equivalents of the claims are included within their scope.

Claims

1. A thermal management system for a computing device, comprising: A liquid immersion tank having a cooling fluid filling at least a portion of the liquid immersion tank; A computing device positioned within the cooling fluid and heating the cooling fluid; A heat block positioned within the cooling fluid and configured to receive heat from the cooling fluid; wherein the heat block comprises: Fluid management features for directing the flow of the cooling fluid to the heat block and the computing device; wherein the heat block is a container having a second material and a third material contained within an internal volume of the heat block; wherein the second material is endothermically reactive with the third material; A thermal management system.

2. The thermal management system of claim 1, wherein the heat block has at least one fluid outlet.

3. The thermal management system of claim 1 or 2, wherein the heat block has an inner surface that complementary fits at least a portion of the topology of the computing device.

4. The thermal management system of any one of claims 1 to 3, wherein the heat block includes a plurality of fluid channels within an inner surface of the heat block.

5. The thermal management system of claim 4, wherein the fluid channels direct vapor bubbles of the cooling fluid towards a vapor collection point of the liquid immersion tank.

6. The thermal management system of claim 4, wherein the fluid channels direct liquid cooling fluid towards heat generating components of the computing device.

7. The thermal management system of claim 6, wherein the fluid channels direct liquid cooling fluid from a liquid cooling fluid return line towards the heat generating components of the computing device.

8. The thermal management system of any one of claims 1 to 7, wherein the inner surface of the heat block is shaped complementary to the topology of the computing device.

9. The thermal management system of any one of claims 1 to 8, wherein the inner surface of the heat block is positioned with a gap between 2 millimeters (mm) and 10 mm from a block surface of the computing device.

10. ​ ​ ​ ​ ​ ​ ​ ​ ​ The thermal management system according to any one of claims 1 to 9, wherein the thermal block has a fiduciary mark on an upper surface of the thermal block, and the fiduciary mark is visible to a machine vision system. **Claim 11**: A thermal management system for a computing device, a liquid immersion tank having a cooling fluid filling at least a portion of the liquid immersion tank, a computing device positioned within the cooling fluid and heating the cooling fluid, a thermal block positioned within the cooling fluid and configured to receive heat from the cooling fluid and comprising: the thermal block is a container having a second material and a third material contained within an internal volume of the thermal block and being endothermically reactive with respect to each other, a thermal management system. **Claim 12** The thermal management system according to claim 11, wherein the second material is a phase change material.

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