WO2025042719A1

WO2025042719A1 - Distillation recovery for two-phase pumped spray cooling server systems

Info

Publication number: WO2025042719A1
Application number: PCT/US2024/042642
Authority: WO
Inventors: Luke Gregory; Robert Jason Lankston; Phillip E. Tuma; Jimil Shah; Ioannis Manousakis; Wilson V. Vu; Joshua HEMELGARN
Original assignee: MTS IP Holdings Ltd
Priority date: 2023-08-21
Filing date: 2024-08-16
Publication date: 2025-02-27

Abstract

A distillation recovery system for use in a two-phase immersion cooling system including a pumped spray cooling system and selected device pool boiling is disclosed. Computing components are cooled through two-phase immersion cooling in thermally conductive, dielectric liquid coolant. Heat from the computing components vaporizes the liquid coolant, which rises to and is cooled by a condenser coil, producing liquid coolant condensate that is recovered via a distillation recovery system. The liquid coolant condensate can be used to further cool computing components via spray cooling and selected device pool boiling. The system may reduce the migration of contaminates in an immersion tank.

Description

DISTILLATION RECOVERY FOR TWO-PHASE PUMPED SPRAY

COOLING SERVER SYSTEMS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Provisional Application No. 63/520,839, filed August 21, 2023, and U.S. Provisional Application No. 63/593,485, filed October 26, 2023, which applications are hereby incorporated by reference in their entireties.

BACKGROUND

[0002] Section 1: As feature sizes and transistor sizes have decreased for integrated circuits (ICs) including chips and semiconductor dies, the amount of heat generated by a single chip, such as a microprocessor, has increased. Chips that once were air cooled have evolved to chips needing more heat dissipation than can be provided by air alone. In some cases, immersion cooling of chips in a tank containing a cooling fluid is employed to maintain IC chips at appropriate operating temperatures.

[0003] One type of immersion cooling is two-phase immersion cooling, in which heat from a semiconductor die boils the cooling fluid. The boiling creates a cooling-fluid vapor in the tank, which is condensed by a heat exchanger, such as a condenser coil, back to liquid form. Heat from the semiconductor dies can then be sunk into the liquid-to-gas and gas-to-liquid phase transitions of the cooling fluid. This allows chips to be run at a faster rate and allows for more computationally intensive processes than were previously possible. Over time, impurities and particulates can leech into the cooling fluid, causing its performance to degrade. To counteract or slow this degradation, filters may be employed to remove impurities from the cooling fluid. However, challenges to the effective maintenance of cooling fluid filters exist.

[0004] Section 2: As feature sizes and transistor sizes have decreased for integrated circuits (ICs) including chips and semiconductor dies, the amount of heat generated by a single chip, such as a microprocessor, has increased. Chips that once were air cooled have evolved to chips needing more heat dissipation than can be provided by air alone. In some cases, immersion cooling of chips in a tank containing a cooling fluid is employed to maintain IC chips at appropriate operating temperatures.

[0005] One type of immersion cooling is two-phase immersion cooling, in which heat from a semiconductor die boils the cooling fluid. The boiling creates a cooling-fluid vapor in the tank, which is condensed by cooling coils back to liquid form. Heat from the semiconductor dies can then be sunk into the liquid-to-gas and gas-to-liquid phase transitions of the cooling fluid. This allows chips to be run at a faster rate and allows for more computationally intensive processes than were previously possible. However, these chips may make use of storage devices located externally to the immersion cooling tank, which can add latency, space, and power inefficiencies.

SUMMARY

[0006] Section 1 : All combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are part of the inventive subject matter disclosed herein. The terminology used herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.

[0007] In some aspects, the techniques described herein relate to a system including an immersion tank to hold a first computing component, a reservoir contained in the immersion tank, the reservoir holding a second computing component at least partially immersed in a liquid coolant, a distillation catchment, disposed in the immersion tank and at least partially separated from the first and second computing components, to capture condensed liquid coolant, a condenser coil, disposed in the immersion tank above a distillation catchment, to condense liquid coolant vaporized by heat emitted by the first and second computing components, a spray nozzle, disposed in the immersion tank, to spray the liquid coolant on the first computing component, a pump, in fluid communication with the distillation catchment and spray nozzle, to pump the condensed liquid coolant through the spray nozzle, and a pipe, in fluid communication with the distillation catchment and pump, to direct the condensed liquid coolant into the pump.

[0008] In some aspects, the techniques described herein relate to a system wherein the liquid coolant is a thermally conductive dielectric liquid coolant.

[0009] In some aspects, the techniques described herein relate to a system wherein the spray nozzle is configured to spray the liquid coolant on a surface of the first computing component continuously during operation of the system. [0010] In some aspects, the techniques described herein relate to a system wherein the spray nozzle includes a plurality of spray nozzles configured to spray the liquid coolant on a surface of the first computing component.

[0011] In some aspects, the techniques described herein relate to a system wherein the distillation catchment has at least one sloped wall to direct the condensed liquid coolant into the pipe.

[0012] In some aspects, the techniques described herein relate to a system wherein the second computing component is a high heat flux computing component. In some aspects, the techniques described herein relate to a system wherein the second computing component is a central processing unit (CPU).

[0013] In some aspects, the techniques described herein relate to a system further including at least one of a temperature sensor coupled to the first computing component to sense a temperature of the first computing component or a sensor to sense a level of the liquid coolant in the reservoir.

[0014] In some aspects, the techniques described herein relate to a system further including a controller operably coupled to the pump and the temperature sensor, wherein the controller is configured to actuate the spray nozzle in response to an indication from the temperature sensor that the temperature of the first computing component is above a predetermined temperature.

[0015] In some aspects, the techniques described herein relate to a system further including an auxiliary tank, in fluid communication with the pump, to supply additional liquid coolant.

[0016] In some aspects, the techniques described herein relate to a system further including a coolant filtration system, in fluid communication with the immersion tank via the spray nozzle, to filter the liquid coolant.

[0017] In some aspects, the techniques described herein relate to a system including an immersion tank to hold a first computing component, a reservoir contained in the immersion tank, the reservoir holding a second computing component at least partially immersed in a liquid coolant, a spray nozzle, disposed in the immersion tank, to spray the liquid coolant on the first computing component, and a distillation recovery system, operably connected to the spray nozzle, to recover condensed liquid coolant.

[0018] In some aspects, the techniques described herein relate to a system wherein the distillation recovery system includes a condenser coil, disposed in the immersion tank above the distillation recovery system, to condense liquid coolant vaporized by heat emitted by the first and second computing components, a sloped distillation catchment, disposed in the immersion tank below the condenser coil, to capture condensed liquid coolant, a pipe, in fluid communication with the distillation catchment to direct the condensed liquid coolant out of the immersion tank, and a pump, in fluid communication with the sloped distillation catchment and spray nozzle, to pump the condensed liquid coolant through the spray nozzle.

[0019] In some aspects, the techniques described herein relate to a system wherein the liquid coolant is a thermally conductive dielectric liquid coolant.

[0020] In some aspects, the techniques described herein relate to a system wherein the spray nozzle is configured to spray the liquid coolant on a surface of the first computing component continuously during operation of the system.

[0021] In some aspects, the techniques described herein relate to a system wherein the spray nozzle includes a plurality of spray nozzles configured to spray the liquid coolant on a surface of the first computing component.

[0022] In some aspects, the techniques described herein relate to a system wherein the second computing component is a high heat flux computing component. In some aspects, the techniques described herein relate to a system wherein the second computing component is a central processing unit (CPU).

[0023] In some aspects, the techniques described herein relate to a system further including at least one of a temperature sensor coupled to the first computing component to sense a temperature of the first computing component or a sensor to sense a level of the liquid coolant in the reservoir.

[0024] In some aspects, the techniques described herein relate to a system further including a controller, operably coupled to the pump, and the temperature sensor to actuate the spray nozzle in response to an indication from the temperature sensor that the temperature of the first computing component is above a predetermined temperature.

[0025] In some aspects, the techniques described herein relate to a system further including an auxiliary tank, in fluid communication with the pump, to supply additional liquid coolant.

[0026] In some aspects, the techniques described herein relate to a system further including a coolant filtration system, in fluid communication with the immersion tank via the spray nozzle, to filter the liquid coolant. [0027] In some aspects, the techniques described herein relate to a method of cooling a computing component in an immersion tank, the method including condensing a liquid coolant within the immersion tank, capturing the condensed liquid coolant in a distillation catchment, disposed in the immersion tank and at least partially separated in the immersion tank from a first and a second computing component, wherein the distillation catchment has at least one sloped wall, the first computing component is held in the immersion tank, and the second computing component is a high heat flux computing component contained in a reservoir and at least partially immersed in a liquid coolant, directing the condensed liquid coolant into a pump, the pump in fluid communication with the distillation catchment and a spray system, pumping the condensed liquid coolant into the spray system, and spraying the condensed liquid coolant continuously during operation on a surface of the first computing component to cool the first computing component.

[0028] Section 2: Computing hardware such as ICs, chips, and semiconductor dies generate heat during operation. Computing hardware may be cooled using ambient or chilled air; however, high-powered computing hardware may produce more heat than air alone can dissipate. Immersion cooling systems may utilize a dielectric liquid to provide better heat dissipation than air, and which also insulate computing hardware within the immersion cooling fluid.

[0029] Storage media such as solid state drives (SSDs) typically generate orders of magnitude less heat than computing hardware and therefore benefit less from being fully immersed in immersion cooling fluid. However, co-location of storage media inside an immersion cooling tank may have several benefits including lower latency between computing hardware and attached storage media, improved space efficiency due to the elimination of storage rack space outside immersion cooling tanks, and reduced need for air chilling and circulation in data centers.

[0030] Further, while the heat generated by storage media during operation is typically far less (potentially orders of magnitude fewer watts) than computing hardware, storage media does generate heat that may need to be removed for proper operation of the storage media. The inventors have appreciated that co-location of storage media inside an immersion cooling tank, particularly located above the immersion cooling liquid in a froth or vapor headspace, can provide the benefits listed above including improvements to latency, space efficiency, and data center power and cooling requirements.

[0031] In some aspects, the techniques described herein relate to a system for immersion cooling. The system includes an immersion cooling tank containing a reservoir of immersion cooling liquid. The system further includes a semiconductor die immersed within the reservoir. The system further includes a storage media disposed within the immersion cooling tank and above the reservoir, and communicatively coupled to the semiconductor die. The system further includes a dispersion means configured to disperse immersion cooling liquid from the reservoir onto the storage media.

[0032] In some aspects, the techniques described herein relate to a system for immersion cooling including a semiconductor die immersed within a reservoir of immersion cooling liquid and a storage media disposed above the reservoir. The storage media is communicatively coupled to the semiconductor die. The system further includes a dispersion means configured to disperse immersion cooling liquid from the reservoir onto the storage media.

[0033] In some aspects, the techniques described herein relate to a system for immersion cooling. The system includes a semiconductor die immersed within a reservoir of immersion cooling liquid and a storage media disposed at least partially within an immersion cooling froth and communicatively coupled to the semiconductor die. The immersion cooling froth is located above the reservoir of immersion cooling liquid.

[0034] In some aspects, the techniques described herein related to a method for immersion cooling. The method includes operating a semiconductor die in a reservoir of immersion cooling liquid. The method further includes dispersing immersion cooling fluid onto a storage media, the storage media disposed above the reservoir and communicatively coupled to the semiconductor die. At least a portion of the dispersed immersion cooling fluid falls back into the reservoir after the dispersing. Dispersing the immersion cooling fluid includes spraying a contiguous stream of liquid, an aerated stream of liquid, liquid droplets, a mist, a froth, or a foam.

[0035] All combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are part of the inventive subject matter disclosed herein. The terminology used herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The skilled artisan will understand that the drawings primarily are for illustrative purposes and are not intended to limit the scope of the inventive subject matter described herein. The drawings are not necessarily to scale; in some instances, various aspects of the inventive subject matter disclosed herein may be shown exaggerated or enlarged in the drawings to facilitate an understanding of different features. In the drawings, like reference characters generally refer to like features (e.g., functionally similar and/or structurally similar elements).

[0037] FIG. 1.1 A illustrates a distillation recovery system for a two-phase immersion cooling system with a pumped spray cooling system and selective device pool boiling.

[0038] FIG. 1.1B illustrates a distillation recovery system for a two-phase immersion cooling system with a pumped spray cooling system, selective device pool boiling, and a heater.

[0039] FIG. 1.1C illustrates a distillation recovery system for a two-phase immersion cooling system with a pumped spray cooling system including a plurality of pumps.

[0040] FIG. 1.2A illustrates a distillation recovery system for a two-phase immersion cooling system with a pumped spray cooling system, selective device pool boiling, and a collection tank.

[0041] FIG. 1.2B illustrates a distillation recovery system for a two-phase immersion cooling system with a pumped spray cooling system, selective device pool boiling, and a two compartment collection tank.

[0042] FIG. 1.3 illustrates a distillation recovery system for a two-phase immersion cooling system with a pumped spray cooling system, selective device pool boiling, and a filtration system.

[0043] FIG. 1.4 illustrates a distillation recovery system for a two-phase immersion cooling system with a pumped spray cooling system.

[0044] FIG. 2.1 depicts aspects of an immersion-cooling system for dissipating heat from one or more semiconductor die packages via immersion cooling.

[0045] FIG. 2.2 illustrates a system for dispersing immersion cooling liquid on storage media housed within an immersion cooling tank.

[0046] FIG. 2.3 illustrates a system including storage media disposed within an immersion cooling froth.

[0047] FIG. 2.4 illustrates a more detailed view of dispersion means used in accordance with the invention. [0048] FIG. 2.5 illustrates an embodiment of a dispersion means used in accordance with the invention.

DETAILED DESCRIPTION

[0049] Section 1 : One challenge with immersion cooling is that printed circuit board (PCB) and ball grid array (BGA) components are usually manufactured with solder fluxes that introduce contamination into the immersion cooling system. Composite cables and thermal materials can also deposit contamination in the form of long-chain hydrocarbons. During boiling in a two-phase immersion cooling system any contamination will concentrate at the site of boiling and the deposition of contaminates will accumulate over time. The accumulation of contamination can lead to electrochemical migration and device failure by creating shorts across the surface components and under the BGAs.

[0050] Spray cooling of a distillate immersion fluid can clean preexisting surface contaminates and provide efficient device cooling in an immersion cooling system. Additionally, selective device pool boiling can reduce the risk of introducing contaminates on higher heat flux boiling surfaces caused by the migration of contaminates to the higher heat flux surface following boiling and evaporation of the cooling fluid. In an immersion tank, fluid contamination may occur when fluid or coolant comes off of a cable or surface in one area of the tank (i.e., an area with contamination, such as a cable, power supply, or a solder flux area) and migrates over to second area of the tank (i.e., a high heat flux area, such as a BGA or central processing unit (CPU)). When that fluid then boils off, the contamination residue is left behind on the second area (e.g., the BGA or CPU), which may lead to degraded performance over time. In contrast, in selective device pool boiling only some of the computing components are immersed in the coolant, which can help reduce the migration of contaminates in the immersion tank. Thus, the present disclosure presents a system for two phase immersion cooling that may mitigate and significantly reduce the known risks associated with contamination in two phase immersion cooling.

Two-Phase Immersion Cooling with Spray Cooling, Selected Device Pool Boiling, and Distillation Recovery

[0051] FIGS. 1.1A-1.1C show a two-phase immersion cooling system 1100 with distillation recovery system 1120 to recover the condensed vapor for use in directed spray cooling and selected device pool boiling. The two-phase immersion cooling system 1100 also includes a pumped spray cooling system 1130 for cooling exposed computing components via spraying and for cooling selected computing components via selected device pool boiling.

[0052] The immersion cooling system 1100 includes a sealed immersion tank 1101 that holds one or more computing components 1104, such as servers, a central processing unit (CPU) 1105, a graphics processor unit (GPU), a data processing unit (DPU), a field-programmable gate array (FPGA), an application- specific integrated circuit (ASIC), memory 1106 (e.g., a dual inline memory module (DIMM)), power supplies, or switches, which are operably connected to other computing components or systems outside the immersion tank 1101, e.g., via the internet or another computer network. One or more of the computing components 1104 may be contained in a reservoir 1102 that contains a liquid coolant 1110, preferably a thermally conductive dielectric liquid coolant such as a fluorochemical with high density, low viscosity, low vapor pressure, and low surface tension. The computing component(s) 1104 within the reservoir 1102 are at least partially immersed in the coolant 1110. During operation, the coolant 1110 in the reservoir 1102 will boil off and convert to vapor.

[0053] The reservoir 1102 allows for selective device pool boiling, which may help to mitigate the effects of fluid contamination in the immersion tank 1101 by significantly reducing and potentially eliminating the spread of new contaminants into the reservoir 1102. Preferably a computing component with a high heat flux is immersed in the reservoir 1102. For example, as shown in FIGS. 1.1A-1.1C, the CPU 1105 may be contained in the reservoir 1102. The reservoir 1102 is at least partially filled with the coolant 1110 such that the CPU 1105 is immersed in the coolant 1110. The reservoir 1102 contains and separates the CPU 1105 from other computing components 1104 that are contained in the immersion tank 1101, such as the memory 1106. Thus, the CPU 1105 may be protected from fluid contamination via fluid migration since the CPU 1105 and memory 1106 are not both immersed in the same coolant pool. This may result in a decrease in the amount of contamination residue left behind on the CPU 1105 after boiling.

[0054] Selective pool boiling may also reduce or eliminate the need for a pump to circulate coolant in an immersion tank. For example, in an immersion tank where all of the computing components are immersed in the coolant, a pump may be utilized to circulate the coolant in the immersion tank, which may increase the critical heat flux on the boiler plates. However, with selective pool boiling, the boiling itself may provide sufficient circulation such that a pump is not needed to circulate the coolant in the selected pool boiling tank (e.g., the reservoir 1102). [0055] The immersion cooling system 1100 may also include a distillation recovery system 1120. The distillation recovery system 1120 includes at least one condenser 1107 (e.g., a condenser coil or another suitable condenser) disposed, in part, in an upper portion of immersion tank 1101 and at least partially segregated from the computing components 1104 and pumped spray cooling system 1130 such that the condenser 1107 is not positioned directly above the computing components 1104 and pumped spray cooling system 1130. The condenser 1107 is filled with chilled water or another suitable chilled fluid. Pipes or conduits 1108 and a pump 1109 connect the condenser 1107 to a heat rejection sub-system 1111, such as a heat exchanger, chilled water loop, evaporative cooling tower, dry cooler, or other suitable mechanism for dissipating heat. The condenser 1107 is configured to extract heat from coolant vapor generated from the coolant liquid during operation thus causing the coolant vapor to condense back to a liquid or condensate 1112. The distillation recovery system 1120 further includes a distillation catchment 1113 to capture the condensate 1112. The distillation catchment 1113 may be at least partially separated from the immersion tank 1101 to allow for fluid isolation of the condensate 1112. The condenser 1107 may be positioned above the distillation catchment 1113 and the distillation catchment 1113 may be sloped such that the condensate 1112 flows into distillation catchment 1113 instead of back into the immersion tank 1101. For example, the distillation catchment 1113 (and/or the portion of the immersion tank 1101 directly below the distillation catchment) may have at least one sloped wall to direct the condensate 1112 out of the immersion tank 1101. Alternatively, the distillation catchment 1113 may be a funnel or in the shape of a funnel to direct the condensate 1112 out of the immersion tank 1101. In another embodiment, the distillation catchment 1113 may be in the form of a recessed cavity in the immersion tank 1101 such that the condenser 1107 may be located in a recessed cavity to allow for fluid isolation of the condensate 1112. The condensate 1112 from the distillation recovery system 1120 may then be used in the spray cooling system 1130 and/or to provide coolant 1110 to the reservoir 1102 for use in selected device pool boiling.

[0056] The immersion cooling system 1100 may also include a spray cooling system 1130. The spray cooling system 1130 includes at least one pump 1114. The pump 1114 is connected to the distillation catchment 1113 of the distillation recovery system 1120 through a pipe or conduit 1115. The pump 1114 is also connected to another pipe or conduit 1118 that runs into the immersion tank 1101. Pump 1114 may be a common pump which creates differential pressure to drive the flow of condensate 1112 into the immersion tank 1101 and the spray cooling system 1130. The pump 1114 may pull from the auxiliary tank 1116 to feed coolant 1110 into the spray cooling system 1130. Alternatively, the spray cooling system 1130 may include multiple pumps positioned along pipes 1118 and/or 1119 to drive the flow of condensate 1112 into the spray nozzle(s) 1121 and to provide redundance in the event of a failure of one pump in the cooling system 1130. For example, the immersion system 1100 may include pump(s) 1138 located near the spray nozzle(s) 1121 to provide additional flow into the spray cooling system 1130. Alternatively, pump(s) 1138 may be located closer to the bottom of the immersion tank 1101 (i.e., towards the bottom of pipe 1119), which may reduce cavitation. Pump(s) 1138 may also provide dynamic control of the spray cooling system 1130 in the event of a failure or increased performance and cooling needs of computing components 1104. Alternatively, the additional pump(s) 1138 may be positioned on or near the reservoir 1102. In this embodiment, the pump(s) 1138 may pull coolant 1110 from the reservoir 1102 to feed into the spray cooling system 1130. A pipe or fluid conduit 1119 connects the outlet of the pump 1114 via pipe 1118 to a spray nozzle 1121, which is mounted above computing components 1104 and pointed toward or at the computing components 1104 (i.e., the memory 1106 and/or one or more additional computing components 1104) . The spray nozzle 1121 may also be pointed towards or at the CPU 1105 and/or any other computing components 1104 contained in the reservoir 1102 to spray the CPU 1105 prior to turning the system on. In operation, the spray cooling system 1130 may spray all of the computing components 1104 (including the memory 1106 and/or the CPU 1105) prior to turning on the immersion cooling system 1100 to mitigate thermal spikes and to coat all computing components 1104 in coolant 1110. The type, size, and shape of spray nozzle 1121 can be selected based on the relatively high density and relatively low viscosity of the liquid coolant 1110. The spray cooling system 1130 may include more than one spray nozzle 1121 and pipe 1119. For example, the spray cooling system 1130 may include two spray nozzles 1121 to spray multiple different computing components 1104, as illustrated in FIG. 1.1 A. Alternatively, the spray cooling system 1130 may also include a plurality of spray nozzles positioned along pipe 1119, as illustrated in FIG. 1.1C. Another pipe or fluid conduit 1122 may connect the outlet of the pump 1114 via pipe 1118 to the reservoir 1102 to supply condensate 1112 or coolant 1110 to the reservoir 1102. The flow of condensate 1112 or coolant 1110 to the reservoir 1102 may be controlled with a valve 1139 (i.e., a flow control valve and/or check valve). Alternatively, the flow of condensate 1112 or coolant 1110 to the reservoir 1102 may continuous and any excess condensate 1112 or coolant 1110 may overflow into the immersion tank 1101. For example, the flow of condensate 1112 or coolant 1110 into the reservoir 1102 may be controlled by gravity. Instead of or in addition to valve 1139, the flow of condensate 1112 or coolant 1110 to the reservoir 1102 may be controlled by a pump 1137. Pump 1137 may be used to provide sufficient coolant 1110 to fill the reservoir 1102 for selective pool boiling. In this embodiment, pump 1137 may direct the flow of condensate 1112 and/or coolant 1110 to the reservoir 1102 instead of to the spray nozzle(s) 1121 for spraying, for example to fill up the reservoir 1102 with coolant 1110 before turning on the immersion cooling system 1100.

[0057] The spray cooling system 1130 may also optionally include a heater 1123 as shown in FIG. 1.1B. The heater 1123 may be positioned near the bottom of the immersion tank 1101. The heater 1123 may be used to heat the coolant 1110. For example, if excess coolant 1110 or condensate 1112 is pumped into the reservoir 1102, it may flow out of the reservoir 1102 and into the immersion tank 1101. If the excess coolant 1110 in the immersion tank 1101 is not evaporating, the heater 1123 may be used to heat the coolant 1110 to allow for evaporation. The heater 1123 may facilitate the cycling of condensate 1112 for use in the spray cooling system 1130. The heater 1123 may also assist in isolating impurities and contaminates in the base of the immersion tank 1101 for filtering and collection.

[0058] The spray cooling system 1130 may also include a board management controller (BMC) 1126 to control the spray cooling system 1130. The BMC 1126 may be operably coupled to a temperature sensor 1127, a flow rate sensor 1134, a pressure sensor 1135, a humidity sensor 1136, the liquid level sensor 1124, the pump 1114, the computing components 1104, and/or to computing components or systems outside immersion tank 1101. For example, the BMC 1126 may monitor the temperature and power (i.e., voltage and/or amperage) of the computing components 1104.

[0059] The temperature sensor 1127 is in thermal communication with the computing components 1104 and the coolant 1110 and may be mounted on the immersion tank 1101, the reservoir 1102, one of the computing components 1104, the memory 1106, or another component or structure within the immersion tank 1101. The spray cooling system 1130 can include a single temperature sensor 1127 or a set or network of temperature sensors 1127, for example, one temperature sensor 1127 on/for each computing component 1104, the immersion tank 1101, or the reservoir 1102. The temperature sensor 1127 may sense the temperature of the computing components 1104.

[0060] The immersion cooling system 1100 may include at least one flow rate sensor 1134. The flow rate sensor 1134 may measure the flow of concentrate 1112 and/or coolant 1110 into the immersion cooling system 1100. The flow rate sensor 1134 may be located on pipe 1118 and/or 1119 to measure the rate of flow of concentrate 1112 and/or coolant 1110 into the spray cooing system 1130. The spray cooling system 1130 can include a single flow rate sensor 1134 or a set or network of flow rate sensors 1134.

[0061] The immersion cooling system 1100 may also include at least one pressure sensor 1135. The pressure sensor 1135 may measure the saturation pressure in the immersion tank 1101 and/or pressure in pipe 1118 and/or 1119. The immersion cooling system 1100 can include a single pressure sensor 1135 or a set or network of pressure sensors 1135.

[0062] The immersion cooling system 1100 may also include a humidity sensor 1136. The humidity sensor 1136 may measure the humidity in the immersion cooling tank 1101. The immersion cooling system 1100 can include a single humidity sensor 1136 or a set or network of humidity sensors 1136. The liquid level sensor 1124 can be a capacitive liquid level sensor, optical (e.g., reflective) liquid level sensor, ultrasonic liquid level sensor, radar liquid level sensor, pressure sensor or transducer, or any other sensor suitable for measuring the level of the coolant surface relative to the level of the upper surface(s) of the CPU 1105 (or another computing components 1104 contained in the reservoir 1102) or another suitable reference level. The liquid level sensor 1124 can be mounted on the inner side of the reservoir 1102, e.g., pointing sideways along at the (normal) level of the coolant surface; on the inner surface of the reservoir’s upper lid, e.g., pointing down; or on the bottom inner surface of the reservoir 1102 pointing up, depending on the type of liquid level sensor 1124.

[0063] In operation, the liquid level sensor 1124 monitors the level of the coolant 1110 in the reservoir 1102 and reports the detected coolant level to the BMC 1126. Depending on the type of liquid level sensor 1124, the liquid level sensor 1124 may report either a representation (e.g., a weight, pressure, or capacitance) of the actual amount or level of liquid coolant 1110 in the reservoir 1102 or a binary reading indicating whether or not the coolant level is at or above the normal coolant level. At the same time, the temperature sensor(s) 1127 monitors the temperature of the CPU 1105 and/or any additional computing components 1104 not contained in the reservoir 1102. A temperature sensor 1127 may also be contained in the reservoir 1102 to monitor the temperature of the CPU 1105. The liquid level sensor 1124 and the temperature sensor(s) 1127 may report measurements or readings continuously, periodically, or on-demand, e.g., in response to a request from the BMC 1126 or another trigger or alert. The temperature of the computing components 1104 may also be measured using external thermocouples,

[0064] The BMC 1126 compares the detected temperature and coolant level to acceptable temperature and coolant level readings, respectively. For instance, the BMC 1126 can determine whether the instantaneous temperature and coolant level readings are within acceptable ranges (e.g., at or about 49 °C or within 5 °C, 2 °C, 1 °C, 0.5 °C, or less of 49 °C or another target temperature). The BMC 1126 can also maintain and make determinations based on running averages and/or peak measurements of the temperature and coolant level, e.g., over the previous 30 seconds, 1 minute, 5 minutes, 10 minutes, 15 minutes, 1 hour, 2 hours, 4 hours, or longer, to account for noise or other potentially spurious fluctuations. If the measured temperature is relatively stable, then the BMC 1126 can sample the temperature sensor(s) 1127 and/or liquid level sensor 1124 relatively infrequently (e.g., every 5-10 minutes); if the measured temperature is fluctuating or changing rapidly, then the BMC 1126 can sample temperature sensor(s) 1127 and/or liquid level sensor 1124 more frequently (e.g., up to several times per minute).

[0065] If the BMC 1126 determines a change in power usage of the memory 1106 or other computing components 1104 not contained in the reservoir 1102, the BMC 1126 adjusts the flow of coolant 1110 from the spray nozzle(s) 1121. The BMC 1126 can also maintain and make determinations based on running averages and/or peak measurements of the power usage of the computing components 1104 (i.e., the memory 1106) frequently (e.g., about several times a second to about a second) For example, if the BMC 1126 detects an increase in power being used by the memory 1106, it turns on the pump 1114 and increases the rate of spray of coolant 1110 (or condensate 1112) from the spray nozzle(s) 1121. The BMC 1126 may also measure performance of the one or more computing components 1104, which may be used to approximate power being used by the computing components 1104. The spray nozzle 1121 discharges or sprays liquid coolant 1110 over the exposed surfaces of the computing components 1104 not contained in the reservoir 1102 (i.e., the memory 1106) to mitigate heat generated by the computing components 1104 during operation. This coolant forms droplets and/or a thin layer of liquid coolant 1110 on the exposed surfaces of the computing components 1104. Heat dissipated through the exposed surfaces of the computing components 1104 vaporizes the liquid coolant droplets/layer, and the vaporized coolant rises to the condenser coil 1107 and distillation system 1120, transferring heat away from the computing components 1104. This spray cooling can protect the computing components 1104 from the heat generated by the computing components 1104. The spray cooling system 1130 allows the computing components 1104 to function without being submerged in coolant 1110 and thus reducing the migration of contamination.

[0066] The immersion cooling system 1100 may also include an auxiliary tank 1116. The auxiliary tank 1116 may be filled with the same coolant 1110 as contained in the reservoir 1102. The auxiliary tank 1116 may be connected to the pump 1114 through a pipe or conduit 1117. The auxiliary tank 1116 may be operably connected to a liquid level sensor 1124 attached to the reservoir 1102. The liquid level sensor 1124 may measure the level of coolant 1110 in the reservoir 1102. The liquid level sensor 1124 may be operably coupled to the auxiliary tank 1116, such that the auxiliary tank 1116 may replenish the coolant in the reservoir 1102 if needed. The auxiliary tank 1116 may also be operably connected to the distillation recovery system 1120 via a sensor 1125 (e.g., a liquid level sensor, a float sensor, and/or a pressure sensor), such that the auxiliary tank 1116 may be used to supplement the condensate 1112 (i.e., to provide additional coolant 1110 to the reservoir 1102 or spray cooling system 1130) if needed.

[0067] Initially, the computing components 1104 not contained in the reservoir 1102 (e.g., the memory 1106) are sprayed with coolant 1110 via the spray nozzle(s) 1121, allowing any contamination accumulated on the surface of the computing components 1104 to fall to the bottom of the sealed immersion tank 1101. The auxiliary tank 1116 may provide the coolant 1110 for the initial spraying of the computing components 1104. Additionally, the auxiliary tank 1116 may also be used to fill the reservoir 1102 with coolant 1110 before the immersion cooling system 1100 is turned on via pumps 1114 and 1122. The computing components 1104 contained in the reservoir 1102 (i.e., the CPU 1105) may also be sprayed with coolant 1110 via the spray nozzle(s) 1121 to remove any contamination from the surface of the CPU 1105 before the immersion cooling system 1100 is turned on. Spraying the computing components 1104 washes off surface particulates, which assists in preventing the accumulation of contamination on the surface of the computing components 1104. When the computing components 1104 are turned on, the sprayed coolant 1110 will evaporate off the surface of the computing components 1104 due to the heat generated by the computing components 1104. The vapor generated from the computing components 1104, including the vapor generated from the pool boiling in the reservoir 1102 will migrate towards the condenser 1107 where it will be condensed into the condensate 1112. The condensate 1112 may be entirely free of contaminates or contain very little contamination (i.e., the condensate 1112 will consist entirely or almost entirely of pure coolant 1110). The condensate 1112 will flow out of the immersion tank 1101 and into the distillation catchment 1113. The condensate 1112 will then be pumped back into the immersion cooling system 1100 through the pump 1114. The condensate (or liquid coolant 1110) may be pumped into the reservoir 1102 for use in pool boiling and/or may also be pumped into the spray cooling system 1130. [0068] During operation, the spray cooling system 1130 may spray the computing components 1104 not contained in the reservoir 1102 (e.g., the memory 1106) with the condensate 1112 generated from the distillation system 1120 (or liquid coolant 1110 from the auxiliary tank 1116) to help cool the computing components 1104. The spray cooling system 1130 may also help reduce the build up of contamination on the computing components 1104 since the spray may wash off any contaminates that have accumulated on the surface of the computing components 1104. Thus, the spray cooling system 1130 may make the surface of the computing components 1104 cleaner, which may allow for more efficient heat transfer. The spray cooling system 1130 may run continuously when the immersion cooling system 1100 is running, such that the spray nozzles 1121 are continuously spraying the computing components 1104 not contained in the reservoir 1102 (e.g., the memory 1106) with coolant 1110. In one embodiment, the flow rate of spray from the spray nozzles 1121 may be controlled based on the power generated by the computing components 1104. For example, if a component is running at 100% utilization, the flow rate of the spray may be higher than if a component is running at 50% utilization. For example, the flow rate of the spray may be controlled by the heat generated by the computing components 1104. For example, a change in temperature of one or more of the computing components 1104 may initiate a change in flow rate of the condensate 1112 and/or coolant 1110 in the spray cooling system 1130. In another embodiment, the spray cooling system 1130 may run intermittently, e.g., whenever the measured temperature exceeds a predetermined temperature. In yet another embodiment, the BMC 1126 can pulse the pump 1114 and spray nozzle 1121 on and off periodically, e.g., at a predetermined frequency and/or duty cycle and/or at a frequency and/or duty cycle based on the measured temperature and coolant level, with more frequent and/or longer spray periods for higher temperatures and less frequent and/or shorter spray periods for lower temperatures.

Two-Phase Immersion Cooling with Spray Cooling, Selected Device Pool Boiling, and Distillation Recovery with a Collection Tank

[0069] FIG. 1.2A shows another embodiment of a two-phase immersion cooling system 1200 with a distillation recovery system 1220 and a pumped spray cooling system 1230. The immersion cooling system 1200 includes a sealed immersion tank 1201 that holds computing components 1104. The CPU 1105 is contained in a reservoir 1202 that contains a thermally conductive dielectric liquid coolant 1110, which allows for selective device pool boiling, as described above. The remaining computing components 1104, including the memory 1106, are contained in the immersion tank 1201.

[0070] The distillation recovery system 1220 includes a condenser 1207, that is filled with chilled water or another suitable coolant. The pump 1209 circulates chilled water or another suitable coolant through the condenser the condenser 1207 and a heat rejection sub-system 1211 via pipes 1208, transferring the heat from the computing components 1104 out of the immersion tank 1201 as described above. The distillation recovery system 1220 further includes a distillation catchment 1213 to capture the condensate 1112 generated from the condenser 1207. The condensate 1112 flows into a collection tank 1216 for use in the pumped spray cooling system 1230. The collection tank 1216 is connected to the distillation catchment 1213 via pipe 1215. The collection tank 1216 may also contain at least a portion of coolant 1110, such that the condensate 1112 supplements the volume of coolant 1110 contained in the collection tank 1216. The collection tank 1216 may be operably connected to a liquid level sensor 1224 attached to the reservoir 1202. The liquid level sensor 1224 may measure the level of coolant 1110 in the reservoir 1202 and the collection tank 1216 replenish the coolant in the reservoir 1202 if needed, as discussed above. The condensate 1112 may flow directly into the collection tank 1216.

[0071] The spray cooling system 1230 further includes at least one pump 1214. The pump 1214 is connected to the collection tank 1216 through pipe 1218 that runs into the immersion tank 1201. The spray cooling system 1230 may include additional pump(s) 1238 positioned along pipes 1218 and/or 1219 to drive the flow of condensate 1112 into the spray nozzle(s) 1221 and to provide redundance in the event of a failure of one pump in the cooling system 1230, as described above. For example, pump(s) 1238 may be located near the spray nozzle(s) 1221 to provide additional flow into the spray cooling system 1230. The pump 1214 may pull from the auxiliary tank 1216 to feed coolant 1110 into the spray cooling system 1230. Alternatively, pump(s) 1238 may be located closer to the bottom of the immersion tank 1201 (i.e., towards the bottom of pipe 1219), which may reduce cavitation. Pump(s) 1238 may also provide dynamic control of the spray cooling system 1230 in the event of a failure or increased performance and cooling needs of computing components 1104. Alternatively, the additional pump(s) 1238 may be positioned on or near the reservoir 1202. In this embodiment, the pump(s) 1238 may pull coolant 1110 from the reservoir 1202 to feed into the spray cooling system 1230.Another pipe or fluid conduit 1219 connects the outlet of the pump 1214 to a spray nozzle 1221, which is mounted above computing components 1104 and pointed toward or at the memory 1106 or one or more additional computing components 1104. The spray nozzle 1221 may also be pointed towards or at the CPU 1105 and/or any other computing components 1104 contained in the reservoir 1202 to spray the CPU 1105 prior to turning the system on. In operation, the spray cooling system 1230 may spray all of the computing components 1104 (including the memory 1106 and/or the CPU 1105) prior to turning on the immersion cooling system 1200 to mitigate thermal spikes and to coat all computing components 1104 in coolant 1110. Another pipe or fluid conduit 1222 connects the outlet of the pump 1214 to the reservoir 1202, as described above. The spray cooling system 1230 may also optionally include a heater 1123, as described above. The spray cooling system 1230 sprays coolant 1110 and/or condensate 1112 onto the computing components 1104 via the spray nozzles 1221. Heat from the computing components 1104 vaporizes the liquid coolant 1110 in the reservoir 1202 and on the surface of the computing components 1104 outside the reservoir 1202 from the spray cooling system 1230, which rises to the condenser 1207 and condenses into the distillation recovery system 1220, cooling the computing components 1104, as discussed above. The type, size, and shape of spray nozzle 1221 can be selected based on the relatively high density and relatively low viscosity of the liquid coolant 1110. The spray cooling system 1230 may also include a plurality of spray nozzles, as described above. The flow of condensate 1112 or coolant 1110 to the reservoir 1202 may be controlled with a valve 1239 (i.e., a flow control valve and/or check valve).

Alternatively, the flow of condensate 1112 or coolant 1110 to the reservoir 1202 may continuous and any excess condensate 1112 or coolant 1110 may overflow into the immersion tank 1201. Instead of or in addition to valve 1239, the flow of condensate 1112 or coolant 1110 to the reservoir 1202 may be controlled by a pump 1237. Pump 1237 may be used to provide sufficient coolant 1110 to fill the reservoir 1202 for selective pool boiling. In this embodiment, pump 1237 may direct the flow of condensate 1112 and/or coolant 1110 to the reservoir 1202 instead of to the spray nozzle(s) 1221 for spraying, for example to fill up the reservoir 1202 with coolant 1110 before turning on the immersion cooling system 1200.

[0072] As discussed above, the spray cooling system 1230 may also include a board management controller (BMC) 1226 to control the spray cooling system 1230. The BMC 1226 may be operably coupled to a temperature sensor 1227, the liquid level sensor 1224, the pump 1214, the computing components 1104, or to computing components or systems outside immersion tank 1201. The temperature sensor(s) 1227 and liquid level sensor 1224 may function as described above with respect to FIGS. 1.1A-1.1C.

[0073] FIG 1.2B shows another embodiment wherein the collection tank 1216 contains multiple compartments (i.e., a first compartment 1216a for the condensate 1112 and a second compartment 1216b for the supplemental liquid coolant 1110), such that the condensate 1112 may flow into a portion of the collection tank 1216 that is separate from the supplemental liquid coolant 1110, as shown in FIG. 1.2B. In this embodiment, the first compartment 1216a and the second compartment 1216b may both be operably connected to the liquid level sensor 1224, such that either the condensate 1112 contained in the first compartment 1216a or the supplemental coolant 1110 contained in the second compartment 1216b may be used to replenish the coolant in the reservoir 1202. In this embodiment, the spray cooling system 1230 may further include a first pump 1214a, connected to the first compartment 1216a, and a second pump 1214b, connected to the second compartment 1216b. Pumps 1214a and 1214b may pump either the condensate 1112 or coolant 1110 into the immersion tank 1201 and spray cooling system 1230 through pipe 1218.

[0074] Like the spray cooling system 1130 in FIGS. 1.1A-1.1C, the spray cooling system 1230 and distillation system 1220 may include a temperature sensor 1227 that measures the temperature of the computing components 1104 and/or coolant 1110 and a liquid level sensor 1224 or other sensor that measures the level or amount of liquid coolant 1110 in the reservoir 1202. The temperature sensor 1227 and liquid level sensor 1224 are coupled to the BMC 1226 that monitors the temperature and level of coolant in the reservoir 1202. The BMC 1226 may also be operably coupled to the pumps 1214a and 1214b, the computing components 1104, or to computing components or systems outside immersion tank 1201.

Two-phase immersion cooling system with a pumped spray cooling system, selective device pool boiling, and a filtration system

[0075] FIG. 1.3 shows a two-phase immersion cooling system 1300 with a distillation recovery system 1320, a pumped spray cooling system 1330, and a filtration system 1340. The immersion cooling system 1300 includes a sealed immersion tank 1301 that holds computing components 1104. The CPU 1105 is contained in a reservoir 1302 that contains liquid coolant 1110, which allows for selective device pool boiling, as described above. The remaining computing components 1104, including the memory 1106, are contained in the immersion tank 1301.

[0076] As in FIGS. 1.1A-1.1C, the distillation recovery system 1320 includes a condenser 1307, that is filled with chilled water or another suitable coolant. The pump 1309 circulates chilled water or another suitable coolant through the condenser the condenser 1307 and a heat rejection sub-system 1311 via pipes 1308, transferring the heat from the computing components 1104 out of the immersion tank 1301 as described above. The distillation recovery system 1320 further includes a distillation catchment 1313 to capture the condensate 1112 generated from the condenser 1307. The condensate 1112 flows into a pump 1314 for use in the pumped spray cooling system 1330. The pump 1314 is connected to the distillation catchment 1313 via pipe 1315. The pump 1314 may be operably connected to a liquid level sensor 1324 attached to the reservoir 1302. The liquid level sensor 1324 may measure the level of coolant 1110 in the reservoir 1302.

[0077] The spray cooling system 1330 further includes at least one pump 1314. The pump 1314 is connected to the distillation catchment 1313 of the distillation recovery system 1320 through a pipe or conduit 1315. The pump 1314 is also connected to another pipe or conduit 1318 that runs into the immersion tank 1301. Alternatively, the spray cooling system 1330 may include multiple pumps positioned along pipes 1318 and/or 1319 to drive the flow of condensate 1112 into the spray nozzle(s) 1321 and to provide redundance in the event of a failure of one pump in the cooling system 1330. For example, the immersion system 1300 may include pump(s) 1338 located near the spray nozzle(s) 1321 to provide additional flow into the spray cooling system 1330. The pump 1314 may pull from the auxiliary tank 1316 to feed coolant 1110 into the spray cooling system 1330. Alternatively, pump(s) 1338 may be located closer to the bottom of the immersion tank 1301 (i.e., towards the bottom of pipe 1319), which may reduce cavitation. Pump(s) 1338 may also provide dynamic control of the spray cooling system 1330 in the event of a failure or increased performance and cooling needs of computing components 1104. Alternatively, the additional pump(s) 1338 may be positioned on or near the reservoir 1302. In this embodiment, the pump(s) 1338 may pull coolant 1110 from the reservoir 1302 to feed into the spray cooling system 1330. Another pipe or fluid conduit 1319 connects the outlet of the pump 1314 to a spray nozzle 1321, which is mounted above computing components 1104 and pointed toward or at the memory 1106 or one or more additional computing components 1104. Another pipe or fluid conduit 1322 connects the outlet of the pump 1314 to the reservoir 1302, as described above. The flow of condensate 1112 or coolant 1110 to the reservoir 1302 may be controlled with a valve 1339 (i.e., a flow control valve and/or check valve). Alternatively, the flow of condensate 1112 or coolant 1110 to the reservoir 1302 may continuous and any excess condensate 1112 or coolant 1110 may overflow into the immersion tank 1301. Instead of or in addition to valve 1339, the flow of condensate 1112 or coolant 1110 to the reservoir 1302 may be controlled by a pump 1337. Pump 1337 may be used to provide sufficient coolant 1110 to fill the reservoir 1302 for selective pool boiling. In this embodiment, pump 1337 may direct the flow of condensate 1112 and/or coolant 1110 to the reservoir 1302 instead of to the spray nozzle(s) 1321 for spraying, for example to fill up the reservoir 1302 with coolant 1110 before turning on the immersion cooling system 1300. The spray cooling system 1330 may also optionally include a heater 1123, as described above. The spray cooling system 1330 sprays coolant 1110 and/or condensate 1112 onto the computing components 1104 via the spray nozzle(s) 1321. Heat from the computing components 1104 vaporizes the liquid coolant 1110 in the reservoir 1302 and on the surface of the computing components 1104 outside the reservoir 1302, which rises to the condenser 1307 and condenses into the distillation recovery system 1320, cooling the computing components 1104, as discussed above. The type, size, and shape of spray nozzle 1121 can be selected based on the relatively high density and relatively low viscosity of the liquid coolant 1110. The spray cooling system 1330 may also include a plurality of spray nozzles as described above.

[0078] As discussed above, the spray cooling system 1330 may also include a board management controller (BMC) 1326 to control the spray cooling system 1330. The BMC 1326 may be operably coupled to a temperature sensor 1327, the liquid level sensor 1324, the pump 1314, the computing components 1104, or to computing components or systems outside immersion tank 1301. The temperature sensor(s) 1327 and liquid level sensor 1324 may function as described above with respect to FIGS. 1.1A-1.1C.

[0079] The immersion cooling system 1300 may also include an auxiliary tank 1316. The auxiliary tank 1316 may be filled with the same coolant 1110 as contained in the reservoir 1302. The auxiliary tank 1316 may be connected to the pump 1314 through a pipe or conduit 1317. The auxiliary tank 1316 may be operably connected to a liquid level sensor 1324 attached to the reservoir 1302 and/or operably connected to the distillation recovery system 1320 via a sensor 1325, as described above.

[0080] The immersion cooling system 1300 may also include a filtration system 1340. The filtration system 1300 may be used to filter the coolant 1110 and/or condensate 1112. The filtration system 1340 may filter contaminants from the coolant 1110 and/or condensate 1112 to a high purity before the coolant 1110 and/or condensate 1112 is re-introduced into the immersion cooling system 1300. The coolant 1110 and/or condensate 1112 may also be tested to determine the presence of any contamination prior to re-introduction into the immersion cooling system. The contamination in the coolant 1110 and/or condensate 1112 may be measured using gas chromatography mass spectrometry (GCMS). The filtration system 1340 also includes an inlet 1328, pump 1329, filter 1331, and outlet 1332. The filtration system 1340 may also include an inline contamination sensor 1333. The inlet 1328 may be coupled to the immersion tank 1301. Preferably the inlet 1328 is located at or near the bottom of the immersion tank 1301 (i.e., at or near the deepest portion of the immersion tank 1301). As shown in FIG. 1.3, the inlet 1328 may be located at or near the bottom of the immersion tank 1301 to filter coolant 1110 located at the bottom of the immersion tank 1301 (i.e., coolant 1110 from the spray cooling system 1330 that may contain contamination or particles washing off from the spraying of the computing components 1104). The outlet 1332 may be coupled to the auxiliary tank 1316, such that the filtered coolant 1110 may be re-introduced into the immersion cooling system 1300. In operation, the pump 1329 draws liquid coolant 1110 from the immersion tank 1301 into the inlet 1328 and the filter 1331. Under normal operating conditions, the filtered liquid coolant 1110 flows back into the auxiliary tank 1316 through the outlet 1332.

Two-Phase Immersion Cooling with Spray Cooling and Distillation Recovery

[0081] FIG. 1.4 shows a two-phase immersion cooling system 1400 with distillation recovery system 1420 to recover the condensed vapor for use in directed spray cooling. The two- phase immersion cooling system 1400 also includes a pumped spray cooling system 1430 for cooling computing components via spraying. The immersion cooling system 1400 includes a sealed immersion tank 1401 that holds computing components 1104, which include memory 1106 and the CPU 1105, at least partially immersed in a thermally conductive dielectric liquid coolant 1110.

[0082] As described above, the immersion cooling system 1400 includes a distillation recovery system 1420. The distillation recovery system 1420 includes a condenser 1407, that is filled with chilled water or another suitable coolant. The pump 1409 circulates chilled water or another suitable coolant through the condenser the condenser 1407 and a heat rejection subsystem 1411 via pipes 1408, transferring the heat from the computing components 1104 out of the immersion tank 1401 as described above. The distillation recovery system 1420 further includes a distillation catchment 1413 to capture the condensate 1112 generated from the condenser 1407. The condensate 1112 flows into a pump 1414 for use in the pumped spray cooling system 1430. The pump 1414 is connected to the distillation catchment 1413 via pipe 1415. The pump 1414 may be operably connected to a liquid level sensor 1424 attached to immersion tank 1401. The liquid level sensor 1424 may measure the level of coolant 1110 in the immersion tank 1401. [0083] The spray cooling system 1430 further includes at least one pump 1414. The pump 1414 is connected to the distillation catchment 1413 of the distillation recovery system 1420 through a pipe or conduit 1415. The pump 1414 is also connected to another pipe or conduit 1418 that runs into the immersion tank 1401. Alternatively, the spray cooling system 1430 may include multiple pumps positioned along pipes 1418 and/or 1419 to drive the flow of condensate 1112 into the spray nozzle(s) 1421 and to provide redundance in the event of a failure of one pump in the cooling system 1430. For example, the immersion system 1400 may include pump(s) 1438 located near the spray nozzle(s) 1421 to provide additional flow into the spray cooling system 1430. The pump 1414 may pull from the auxiliary tank 1416 to feed coolant 1110 into the spray cooling system 1430. Alternatively, pump(s) 1438 may be located closer to the bottom of the immersion tank 1401 (i.e., towards the bottom of pipe 1419), which may reduce cavitation. Pump(s) 1438 may also provide dynamic control of the spray cooling system 1430 in the event of a failure or increased performance and cooling needs of computing components 1104. Another pipe or fluid conduit 1419 connects the outlet of the pump 1414 to a spray nozzle 1421, which is mounted above computing components 1104 and pointed toward or at the memory 1106 or one or more additional computing components 1104. Another pipe or fluid conduit 1422 connects the outlet of the pump 1414 to the immersion tank 1401. The flow of condensate 1112 or coolant 1110 to the immersion tank 1401 may be controlled with a valve 1439 (i.e., a flow control valve and/or check valve). Alternatively, the flow of condensate 1112 or coolant 1110 to the immersion tank 1401 may continuous. Instead of or in addition to valve 1439, the flow of condensate 1112 or coolant 1110 to the immersion tank 1401 may be controlled by a pump 1437. Pump 1437 may be used to provide sufficient coolant 1110 to fill the immersion tank 1401 for immersion cooling of the computing components 1104. In this embodiment, pump 1437 may direct the flow of condensate 1112 and/or coolant 1110 to the immersion tank instead of to the spray nozzle(s) 1421 for spraying, for example to fill up the immersion tank 1401 with coolant 1110 before turning on the immersion cooling system 1400. The spray cooling system 1430 may also be used to spray a computing component 1104 exposed by a drop in the level of the liquid coolant 1110 in the immersion tank 1401 in the event of coolant loss due to a leak or other emergencies.

[0084] The spray cooling system 1430 may also optionally include a heater 1123, as described above. The spray cooling system 1430 sprays coolant 1110 and/or condensate 1112 onto the computing components 1104 via the spray nozzle(s) 1421. Heat from the computing components 1104 vaporizes the liquid coolant 1110 in immersion tank 1401, which rises to the condenser 1407 and condenses into the distillation recovery system 1420, cooling the computing components 1104, as discussed above. The type, size, and shape of spray nozzle 1421 can be selected based on the relatively high density and relatively low viscosity of the liquid coolant 1110. The spray cooling system 1430 may also include a plurality of spray nozzles as described above.

[0085] As discussed above, the spray cooling system 1430 may also include a board management controller (BMC) 1426 to control the spray cooling system 1430. The BMC 1426 may be operably coupled to a temperature sensor 1427, the liquid level sensor 1424, the pump 1414, the computing components 1104, or to computing components or systems outside immersion tank 1401. The BMC 1426 may also be operably coupled to a flow rate sensor, a pressure sensor, and/or humidity sensor, as discussed above. The temperature sensor(s) 1427 and liquid level sensor 1424 may function as described above with respect to FIGS. 1.1A-1.1C. Additionally, in this embodiment, the liquid level sensor 1424 may measure the level of coolant 1110 contained in the immersion tank 1401.

[0086] The immersion cooling system 1400 may also include an auxiliary tank 1416. The auxiliary tank 1416 may be filled with the same coolant 1110 as contained in the immersion tank 1401. The auxiliary tank 1416 may be connected to the pump 1414 through a pipe or conduit 1417. The auxiliary tank 1416 may be operably connected to a liquid level sensor 1424 attached to the immersion tank 1401 and/or operably connected to the distillation recovery system 1420 via a sensor 1425, as described above.

[0087] The immersion cooling system 1400 may be modified in any of the ways described above and shown in FIGS. 1.1A-1.1C, 1.2A-B, or 1.3 (i.e., to include a filtration system and/or a collection tank).

[0088] Section 2: FIG. 2.1 depicts aspects of an immersion-cooling system 2100 for dissipating heat from one or more semiconductor die packages 2105 via immersion cooling. Each package 2105 can include one or more semiconductor dies that produce heat when the system is in operation. The immersion-cooling system 2100 in the illustrated example of FIG. 2.1 is a two-phase immersion-cooling system, though the invention may also be implemented in a single-phase immersion-cooling system.

[0089] The immersion-cooling system 2100 includes a container such as tank 2107 filled, at least in part, with immersion cooling liquid 2164. The immersion-cooling system 2100 can further include at least one chiller 2180 that flows a heat-transfer fluid through at least one condenser coil 2170 that is disposed in the tank 2107 and headspace 2108. Condenser coil 2170 and chiller 2180 may be part of a heat exchanger. The packages 2105 can be mounted on one or more printed circuit boards (PCBs) 2157 that are immersed, at least in part, in the immersion cooling liquid 2164. Immersion-cooling system 2100 may further include a filter 2175 disposed adjacent to the tank 2107.

[0090] Filter 2175 may include a filtration media, a housing, and a pump configured to force immersion cooling liquid 2164 through filter 2175 to remove contaminants, particulates, or other impurities that may be added to immersion cooling liquid 2164 during use. Filter 2175 may be housed outside of tank 2107 while being in fluidic communication with immersion cooling liquid 2164 in tank 2107. Alternatively, filter 2175 may be submerged within immersion cooling liquid 2164 inside of tank 2107.

[0091] Immersion cooling liquid 2164 may be a hydrocarbon, a fluoroketone, an oil, or a similar dielectric liquid that will act as an insulator while simultaneously transferring heat from package 2105 more efficiently than air. An example of immersion cooling liquid 2164 is Novec™ 2649 produced by 3M™. An exemplary immersion cooling liquid 2164 used in accordance with embodiments of the present invention may have a dielectric constant baseline value of about 1.8-2 at a frequency of about 1 kHz.

[0092] In an embodiment of the invention, immersion cooling liquid 2164 may be considered unacceptably contaminated if the dielectric constant and/or dielectric loss tangent of immersion cooling fluid being used in an immersion-cooling system 2100 differs by a threshold amount as compared to unused or pure immersion cooling liquid 2164. For example, immersion cooling liquid 2164 may be considered unacceptably contaminated or degraded if the dielectric constant and/or dielectric loss tangent differs by a threshold of 10% or more as compared to unused or pure immersion cooling liquid 2164. In an embodiment, a dielectric constant and/or dielectric loss tangent variation threshold may be 20%, 15%, 5%, 3%, 1%, or any suitable threshold.

[0093] Contamination of the immersion cooling liquid 2164 and resulting changes to dielectric constant and/or dielectric loss tangent may alter or negatively impact operation of components within immersion cooling liquid 2164 including semiconductor die(s) 2150. An altered dielectric constant and/or dielectric loss tangent may result in undesirable cross-talk between components on a PCB, additional noise or reduction in signal strength transmitted along exposed wires of a PCB or semiconductor die(s) 2150 submerged in immersion fluid, and/or signal dissipation through the immersion cooling liquid 2164. Signal loss may be severe enough that two elements may be effectively represented as being separated by an open circuit despite being physically connected. In an embodiment, a dielectric constant and/or dielectric loss tangent variation threshold may be selected based on an observed or inferred effect on one or more submerged semiconductor die(s) 2150. For example, an increase in PCIe bit error rate above an error rate baseline may be correlated with an increase in dielectric constant and/or dielectric loss tangent above a dielectric constant and/or dielectric loss tangent baseline. Accordingly, operation of semiconductor die(s) 2150 may be throttled or suspended when a dielectric constant and/or dielectric loss tangent of immersion cooling liquid 2164 exceeds a predetermined threshold.

[0094] Changes to dielectric constant and/or dielectric loss tangent may be caused by contaminants within immersion cooling liquid 2164. In some cases, changes to dielectric constant and/or dielectric loss tangent may be reversed by filtering the contaminants from immersion cooling liquid 2164. In some embodiments, upon detecting an increase in dielectric constant and/or dielectric loss tangent of immersion cooling liquid 2164, controller 2102 may instruct filter 2175 to increase filtration throughput or notify a user that a immersion cooling liquid 2164 filtration media may need to be replaced. If a dielectric constant and/or dielectric loss tangent exceeds a predetermined threshold, controller 2102 may throttle or shut down one or more semiconductor die(s) 2150, generate a notification that immersion cooling liquid 2164 should be replaced, trigger an alarm, etc.

[0095] The illustrated example of FIG. 2.1 is not intended to be to scale. The immersioncooling system 2100 may house and provide immersion cooling liquid 2164 to tens, hundreds, or even thousands of packages 2105. In some cases, the immersion-cooling system 2100 can be small (e.g., the size of a floor unit air conditioner, approximately 1 meter high, 0.5 meter width, 0.5 meter depth or length). In some implementations, the immersion-cooling system can be large (e.g., the size of a van or larger, approximately 2.5 meters high, 2.5 meters width, 4 meters depth or length).

[0096] The immersion-cooling system 2100 can also include a controller 2102 (e.g., a microcontroller, programmable logic controller, microprocessor, field-programmable gate array, logic circuitry, memory, or some combination thereof) to manage system operation. The controller 2102 can perform various system functions such as monitoring temperatures of system components, cooling fluid level, tank access, chiller operation etc. The controller 2102 can further issue commands to control system operation such as executing a start-up sequence, executing a shut-down sequence, assigning workloads among the packages, changing cooling fluid level, changing the temperature of the heat- transfer fluid circulated by the chiller 2180, etc. In some implementations, the controller 2102 can include (or itself be) a baseboard management controller (BMC) 2104. That is, the BMC 2104 may monitor and control all aspects of system operation for the immersion-cooling system 2100 in addition to monitoring and controlling workloads of the semiconductor dies 2150 in the packages 2105 cooled by the system. The immersion-cooling system 2100 can also include a network interface controller (NIC) 2103 to allow the system to communicate over a network, such as a local area network or wide area network. The immersion-cooling system 2100 can further include a fluid sensor array 2190 having a plurality of fluid sensors 2110. Fluid sensors 2110 may include one or more leak detection sensors at least partially submerged in immersion cooling liquid 2164.

[0097] The semiconductor die(s) 2150 and can be mounted on and attached to a printed circuit board (PCB) 2155 (sometimes referred to as a substrate) in the device package 2105. The package 2105 can be made commercially available as an off-the-shelf (OTS) product. The package 2105 can be used for single-phase or two-phase immersion cooling of at least one semiconductor die 2150, such as a microprocessor (e.g., a central processing unit (CPU) and/or graphic processing unit (GPU)), voltage regulator (VR), high bandwidth memory (HBM), a digital signal processing (DSP) die, an application-specific integrated circuit (ASIC), field- programmable gate array (FPGA), and/or other densely patterned semiconductor die.

[0098] In the two-phase immersion-cooling system 100 of FIG. 2.1, heat flows from the semiconductor die 2150 where it is generated into the heat spreader 2152. The heat spreader 2152 is in thermal contact with an immersion cooling liquid 2164 that can flow over and extract heat from the heat spreader 2152. The amount of heat delivered by the heat spreader 2152 to the immersion cooling liquid 2164 is enough to boil the immersion cooling liquid 2164 that contacts the heat spreader 2152 (creating bubbles 2165 and potentially creating froth 2167 when bubbles 2165 reach the surface of immersion cooling liquid 2164). The vapor 2166 from the boiled immersion cooling liquid 2164 can be cooled and condensed back to liquid droplets 2168, for example, by the condenser coil 2170. The heat-transfer fluid, such as chilled water, from the chiller 2180 can be circulated through the condenser coil 2170 to lower the temperature of the condenser coil 2170 below the condensation point in the headspace 2108 of the tank 2107. As a result, the vapor 2166 condenses on exterior surfaces of the condenser coil 2170 and liquid droplets 2168 from the condensed vapor can drip and/or flow back to the immersion cooling liquid 2164. Although a single condenser coil 2170 is depicted in FIG. 2.1, there can be a plurality of condenser coils 2170 in the tank 2107 to condense the vapor 2166 into droplets. Some or all of the condenser coils 2170 may or may not be located directly over the PCBs 2157. Instead, the condenser coil(s) 2170 can be located near one or more walls of the tank 2107, such 1 that the condenser coil(s) 2170 are not directly over the PCBs 2157 on which the packages 2105 are mounted.

[0099] To improve thermal performance in two-phase immersion-cooling system 2100, the heat spreader 2152 can include a boiling enhancement coating (BEC) on at least one surface. The BEC can be formed from copper or a copper alloy and can be porous, for example, though BECs can take various forms. In some cases, the BEC is a micro porous copper coating having a thickness from approximately or exactly 50 microns to 100 microns thick (which may be produced by electroplating and/or etching). In some implementations, the BEC comprises a mesh copper layer bonded (e.g., via resistance heating) to at least an outer surface of the heat spreader 2152. In some cases, the BEC is applied as particulates to at least one smooth surface of the heat spreader 2152 and then subsequently sintered to adhere to one another and to the heat spreader 2152. The BEC provides an improved surface area to contact the immersion cooling liquid 2164 and can increase the heat transfer coefficient from the heat spreader 2152 to the immersion cooling liquid 2164 by up to a factor of 15 versus a smooth surface on the heat spreader 2152. Accordingly, BECs can increase thermal conductivity to, and accelerate the boiling of, the immersion cooling liquid 2164.

[0100] FIG. 2.2 illustrates a system for dispersing immersion cooling liquid on storage media housed within an immersion cooling tank. System 2200 may include tank 2205. Tank 2205 may contain a reservoir of immersion cooling liquid 2210. Computing hardware 2220 may be partially or fully immersed in immersion cooling liquid 2210. Computing hardware 2220 may include one or more semiconductor dies (such as semiconductor die(s) 2150). In an embodiment, computing hardware 2220 may include one or more CPU servers, one or more GPU servers, one or more Al training clusters, or the like. During operation, heat from computing hardware 2220 may cause immersion cooling liquid 2210 to boil, creating immersion cooling vapor. This immersion cooling vapor may rise through immersion cooling liquid 2210 and into headspace 2218. As the immersion cooling vapor rises through the surface of immersion cooling liquid 2210, it may disturb the surface of immersion cooling liquid 2210 and cause the formation of immersion cooling froth 2212 or similar immersion cooling bubbles.

[0101] System 2200 may further include storage media 2230, which may include one or more individual storage units 2230a-h. Storage media 2230 may include flash memory, solid state drives (SSDs), hard disks (such as spinning platter hard drives), dynamic memory modules such as dual in-line memory modules (DIMMs) or similar random access memory (RAM) modules, or any media suitable for storing data electronically. Storage media 2230 may be communicatively coupled to computing hardware 2220 so that computing hardware 2220 may transfer, retrieve, or store data on storage media 2230 during operation. In an embodiment, storage media 2230 may store data used by computing hardware 2220 to perform calculations, control computing hardware 2220 (such as an operating system), store results of calculations performed by computing hardware 2220, store data sets for training artificial intelligence (Al) models, or storing any data that computing hardware 2220 may utilize in operation.

[0102] System 2200 may further include heat exchanger 2240, which may include condenser coils or tubes such as condenser coil 2170. Heat exchanger 2240 may include copper tubes through which a thermal transfer fluid is flowed, chilling the copper tubes. When heated immersion cooling vapor contacts the copper tubes, the immersion cooling vapor recondenses into liquid form and falls back into immersion cooling liquid 2210. This cycle of boiling and recondensation of immersion cooling fluid may enable an efficient removal of excess heat during operation of computing hardware 2220.

[0103] While storage media 2230 may generate less heat than computing hardware 2220, storage media 2230 may benefit from being located within tank 2205 and being exposed to immersion cooling liquid 2210. As discussed above, disposing storage media 2230 in tank 2205 may provide several benefits discussed above including reduced latency, improved data center floorspace usage due to the elimination of external racks for storage media, and reduced need for ambient air thermal management and circulation hardware. To maximize power and thermal management efficiency, available space within immersion cooling liquid 2210 may be prioritized for computing hardware 2220. This may leave the space directly above immersion cooling liquid 2210 available for storage media 2230, which may not generate enough heat to warrant immersion within immersion cooling liquid 2210.

[0104] However, storage media 2230 generates heat during operation (albeit less than computing hardware 2220) and may benefit from some exposure to immersion cooling fluid (such as immersion cooling liquid 2210). The inventors have recognized that placement of storage media 2230 within an immersion cooling system such as system 2200 and tank 2205 more particularly, may allow for storage media 2230 to be exposed to immersion cooling liquid 2210 and benefit from the accompanying thermal management. In an embodiment, storage media 2230 may be disposed in headspace 2218, which may primarily contain air or a mixture of air and immersion cooling vapor.

[0105] System 2200 may include dispersion means 2250 and fluid pump 2255. Dispersion means 2250 may be a mechanism designed to disperse immersion cooling liquid 2210 into contact with storage media 2230, for example by applying immersion cooling fluid spray 2260 to storage media 2230. Dispersion means 2250 may include one or more tubes, pipes, hoses, ducts, or conduits suitable for containing a pressurized flow of fluid. Dispersion means 2250 may be connected to fluid pump 2255 such that a flow of pressurized immersion cooling liquid 2210 is forced through dispersion means 2250. Dispersion means 2250 may overhang storage media 2230, for example by being secured to a sidewall or lid of tank 2205.

[0106] Dispersion means 2250 may have one or more openings in portions of dispersion means 2250 adjacent to storage media 2230. These openings may permit a flow or spray of immersion cooling liquid 2210 (such as immersion cooling fluid spray 2260) such that pressurized immersion cooling liquid 2210 flows from fluid pump 2255, through dispersion means 2250, and out of one or more openings in portions of dispersion means 2250, causing immersion cooling fluid spray 2260 to disperse immersion cooling fluid (such as immersion cooling liquid 2210 or immersion cooling foam) onto storage media 2230. Immersion cooling fluid spray 2260 may be a contiguous stream of liquid, an aerated stream of liquid (for example aerated by a mesh disposed in the one or more openings in dispersion means 2250), a stream or spray of liquid droplets, a stream or spray of froth or foam, a mist, or any suitable form of moving immersion cooling fluid. This dispersion of immersion cooling fluid allows for excess heat to be removed from storage media 2230 and allows for the benefits of co-location of computing hardware 2220 and storage media 2230 to be realized.

[0107] Dispersion means 2250 may additionally include one or more sprinkler heads or similar elements for breaking up a flow of immersion cooling fluid into smaller droplets and more efficiently dispersing the immersion cooling fluid onto storage media 2230. For example, one or more openings may direct a contiguous stream of immersion cooling fluid at a sprinkler head, which may disrupt the contiguous stream and break it into smaller droplets.

[0108] System 2200 may include controller 2202 and BMC 2204, which may be analogous to controller 2102 and BMC 2104 in FIG. 2.1. Controller 2202 and/or BMC 2204 may be communicatively coupled to computing hardware 2220, storage media 2230, and/or fluid pump 2255 and may operate or affect operation of computing hardware 2220, storage media 2230, and or fluid pump 2255. For example, controller 2202 and/or BMC 2204 may dynamically control operation of fluid pump 2255 and resulting immersion cooling fluid spray 2260 through dispersion means 2250. In an embodiment, controller 2202 and/or BMC 2204 may send one or more signals to fluid pump 2255 to command a pumping speed of fluid pump 2255, which may directly control a flow rate of immersion cooling fluid spray 2260. In an embodiment, controller 2202 and/or BMC 2204 may set a pumping speed or change a pumping speed of fluid pump 2255 in response to a workload of computing hardware 2220, a workload of storage media 2230, a measured temperature of storage media 2230 including any one or more of individual storage units 2230a-h, or a suitable signal.

[0109] FIG. 2.3 illustrates a system 2300 including storage media 2330 located above a reservoir of an immersion cooling liquid 2310 contained by tank 2305, but within an immersion cooling froth 2312. Immersion cooling froth 2312 may be formed by immersion cooling vapor escaping from immersion cooling liquid 2310 during operation of computing hardware 2320. Storage media 2330 may be disposed at a predetermined distance above immersion cooling liquid 2310 such that storage media 2330 may be disposed at least partly within immersion cooling froth 2312 during operation. Storage media may include one or more individual storage units 2330a-h analogous to storage units 2230a-h in FIG. 2.2.

[0110] System 2300 may optionally lack dispersion means 2250, fluid pump 2255, and/or immersion cooling fluid spray 2260. Instead, storage media 2330 may be cooled by contact with immersion cooling froth 2312. Storage media 2330 may be additionally or alternatively be cooled by splashing of immersion cooling liquid 2310, which may be caused by immersion cooling vapor bubbling or rising out of immersion cooling liquid 2310 during operation of computing hardware 2320, This may have the benefit of allowing for the exclusion of dispersion means 2250 and fluid pump 2255 since the splashing, bubbling, and/or frothing of immersion cooling liquid 2310 may occur when computing hardware 2320 is operating and generating excess heat, which is also when storage media 2330 may have excess heat to remove. In this manner, the same operation of computing hardware 2320 and storage media 2330 that causes excess heat to be generated may also cause splashing, bubbling, and/or frothing of immersion cooling liquid 2310 required for cooling storage media 2330.

[0111] Computing hardware 2320 may be partially or fully immersed in immersion cooling liquid 2310. Computing hardware 2320 may include one or more semiconductor dies (such as semiconductor die(s) 2150). In an embodiment, computing hardware 2320 may include one or more CPU servers, one or more GPU servers, one or more Al training clusters, or the like. During operation, heat from computing hardware 2320 may cause immersion cooling liquid 2310 to boil, creating immersion cooling vapor. This immersion cooling vapor may rise through immersion cooling liquid 2310 and into headspace 2318. Similar to FIG. 2.2, as the immersion cooling vapor rises through the surface of immersion cooling liquid 2310, it may disturb the surface of immersion cooling liquid 2310 and cause the formation of immersion cooling froth 2312 or similar immersion cooling bubbles.

[0112] Storage media 2330 may include flash memory, solid state drives (SSDs), hard disks (such as spinning platter hard drives), dynamic memory modules such as dual in-line memory modules (DIMMs) or similar random access memory (RAM) modules, or any media suitable for storing data electronically. Storage media 2330 may be communicatively connected to computing hardware 2320. In an embodiment, storage media 2330 may store data used by computing hardware 2320 to perform calculations, control computing hardware 2320 (such as an operating system), store results of calculations performed by computing hardware 2320, store data sets for training artificial intelligence (Al) models, or storing any data that computing hardware 2320 may utilize in operation.

[0113] System 2300 may further include heat exchanger 2340, which may include condenser coils or tubes such as condenser coil 2170. Heat exchanger 2340 may include copper tubes through which a thermal transfer fluid is flowed, chilling the copper tubes. When heated immersion cooling vapor contacts the copper tubes, the immersion cooling vapor recondenses into liquid form and falls back into immersion cooling liquid 2310. This cycle of boiling and recondensation of immersion cooling fluid may enable an efficient removal of excess heat during operation of computing hardware 2320.

[0114] FIG. 2.4 illustrates a more detailed view of dispersion means used in accordance with the invention. Dispersion system 2400 may include a fluid pump 2455 disposed at least partly within a reservoir of an immersion cooling liquid 2410. Fluid pump 2455 may be configured to draw immersion cooling liquid 2410 into an inlet and increase a pressure of immersion cooling liquid 2410 to create a flow of immersion cooling liquid 2410 from fluid pump 2455, through piping 2452, and exiting through one or more openings such as openings 2454a and 2454b. Pressurized immersion cooling liquid 2410 exiting through openings 2454a and 2454b may form immersion cooling fluid spray 2460, which may then contact and cool storage media 2430a and 2430b.

[0115] Openings 2454a and 2454b may be shaped or placed to control a form and/or flow rate of immersion cooling fluid spray 2460. For example, openings 2454a and 2454b may have a circular profile, an oval or elliptical profile, or an abstract shape profile. Openings 2454a and 2454b may include a screen or mesh to aerate the flow of immersion cooling liquid 2410. Dispersion system 2400 may include one or more sprinklers 2456a and 2456b for dispersing or breaking up a flow of immersion cooling liquid 2410 upon exiting piping 2452 and openings 2454a and 2454b. Sprinklers 2456a and 2456b may be rigid or may include a rotating component configured to disperse immersion cooling fluid spray 2460 more evenly onto storage media 2430a and 2430b.

[0116] FIG. 2.5 illustrates an embodiment of a dispersion means used as part of dispersion system 2500. Dispersion system 2500 may include a fluid pump 2555 analogous to fluid pump 2455, piping 2552 analogous to piping 2452, openings 2554a and 2554b analogous to openings 2454a and 2454b, sprinklers 2556a and 2556b analogous to sprinklers 2456a and 2456b, storage media 2530a and 2530b analogous to storage media 2430a and 2430b. However, dispersion system 2500 may differ from dispersion system 2400 in that fluid pump 2555 may be disposed at least partially within immersion cooling froth 2512. Fluid pump 2555 may pump immersion cooling fluid that may be entirely immersion cooling froth 2512, or partly immersion cooling froth 2512 and partly immersion cooling liquid from the reservoir of immersion cooling liquid 2510.

[0117] In an embodiment, immersion cooling fluid spray 2560 may consist entirely of immersion cooling froth 2512 or may be partly immersion cooling froth 2512 and partly immersion cooling liquid 2510. Openings 2554a and 2554b may be shaped or placed to control a form and/or flow rate of immersion cooling fluid spray 2560. For example, openings 2554a and 2554b may have a circular profile, an oval or elliptical profile, or an abstract shape profile. Openings 2554a and 2554b may include a screen or mesh to aerate the flow of immersion cooling liquid 2510. Dispersion system 2500 may include one or more sprinklers 2556a and 2556b for dispersing or breaking up a flow of immersion cooling liquid 2510 upon exiting piping 2552 and openings 2554a and 2554b. Sprinklers 2556a and 2556b may be rigid or may include a rotating component configured to disperse immersion cooling fluid spray 2560 more evenly onto storage media 2530a and 2530b.

Conclusion

[0118] While various inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

[0119] Also, various inventive concepts may be embodied as one or more methods, of which an example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.

[0120] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.

[0121] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0122] The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and/or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc. [0123] As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0124] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0125] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

Claims

1. A system comprising: an immersion tank to hold a first computing component; a reservoir contained in the immersion tank, the reservoir holding a second computing component at least partially immersed in a liquid coolant; a distillation catchment, disposed in the immersion tank and at least partially separated from the first and second computing components, to capture condensed liquid coolant; a condenser coil, disposed in the immersion tank above a distillation catchment, to condense liquid coolant vaporized by heat emitted by the first and second computing components; a spray nozzle, disposed in the immersion tank, to spray the liquid coolant on the first computing component; a pump, in fluid communication with the distillation catchment and spray nozzle, to pump the condensed liquid coolant through the spray nozzle; and a pipe, in fluid communication with the distillation catchment and pump, to direct the condensed liquid coolant into the pump.

2. The system of claim 1, wherein the liquid coolant is a thermally conductive dielectric liquid coolant.

3. The system of claim 1, wherein the spray nozzle is configured to spray the liquid coolant on a surface of the first computing component continuously during operation of the system.

4. The system of claim 1, wherein the spray nozzle comprises a plurality of spray nozzles configured to spray the liquid coolant on a surface of the first computing component.

5. The system of claim 1, wherein the distillation catchment has at least one sloped wall to direct the condensed liquid coolant into the pipe.

6. The system of claim 1, wherein the second computing component is a high heat flux computing component.

7. The system of claim 6, wherein the second computing component is a central processing unit (CPU).

8. The system of claim 1, further comprising at least one of: a temperature sensor coupled to the first computing component to sense a temperature of the first computing component; or a sensor to sense a level of the liquid coolant in the reservoir.

9. The system of claim 8, further comprising a controller operably coupled to the pump and the temperature sensor; wherein the controller is configured to actuate the spray nozzle in response to an indication from the temperature sensor that the temperature of the first computing component is above a predetermined temperature.

10. The system of claim 1, further comprising: an auxiliary tank, in fluid communication with the pump, to supply additional liquid coolant.

11. The system of claim 1, further comprising: a coolant filtration system, in fluid communication with the immersion tank via the spray nozzle, to filter the liquid coolant.

12. A system comprising: an immersion tank to hold a first computing component; a reservoir contained in the immersion tank, the reservoir holding a second computing component at least partially immersed in a liquid coolant; a spray nozzle, disposed in the immersion tank, to spray the liquid coolant on the first computing component; and a distillation recovery system, operably connected to the spray nozzle, to recover condensed liquid coolant.

13. The system of claim 12, wherein the distillation recovery system comprises: a condenser coil, disposed in the immersion tank above the distillation recovery system, to condense liquid coolant vaporized by heat emitted by the first and second computing components; a sloped distillation catchment, disposed in the immersion tank below the condenser coil, to capture condensed liquid coolant; a pipe, in fluid communication with the distillation catchment to direct the condensed liquid coolant out of the immersion tank; and a pump, in fluid communication with the sloped distillation catchment and spray nozzle, to pump the condensed liquid coolant through the spray nozzle.

14. The system of claim 12, wherein the liquid coolant is a thermally conductive dielectric liquid coolant.

15. The system of claim 12, wherein the spray nozzle is configured to spray the liquid coolant on a surface of the first computing component continuously during operation of the system.

16. The system of claim 12, wherein the spray nozzle comprises a plurality of spray nozzles configured to spray the liquid coolant on a surface of the first computing component.

17. The system of claim 12, wherein the second computing component is a high heat flux computing component.

18. The system of claim 17, wherein the second computing component is a central processing unit (CPU).

19. The system of claim 13, further comprising at least one of: a temperature sensor coupled to the first computing component to sense a temperature of the first computing component; or a sensor to sense a level of the liquid coolant in the reservoir.

20. The system of claim 19, further comprising a controller, operably coupled to the pump, and the temperature sensor to actuate the spray nozzle in response to an indication from the temperature sensor that the temperature of the first computing component is above a predetermined temperature.

21. The system of claim 13, further comprising: an auxiliary tank, in fluid communication with the pump, to supply additional liquid coolant.

22. The system of claim 12, further comprising: a coolant filtration system, in fluid communication with the immersion tank via the spray nozzle, to filter the liquid coolant.

23. A method of cooling a computing component in an immersion tank, the method comprising: condensing a liquid coolant within the immersion tank; capturing the condensed liquid coolant in a distillation catchment, disposed in the immersion tank and at least partially separated in the immersion tank from a first and a second computing component, wherein: the distillation catchment has at least one sloped wall; the first computing component is held in the immersion tank; and the second computing component is a high heat flux computing component contained in a reservoir and at least partially immersed in a liquid coolant; directing the condensed liquid coolant into a pump, the pump in fluid communication with the distillation catchment and a spray system; pumping the condensed liquid coolant into the spray system; and spraying the condensed liquid coolant continuously during operation on a surface of the first computing component to cool the first computing component.

24. A system for immersion cooling, the system comprising: an immersion cooling tank containing a reservoir of immersion cooling liquid; a semiconductor die immersed within the reservoir; a storage media disposed within the immersion cooling tank and above the reservoir, and communicatively coupled to the semiconductor die; and a dispersion means configured to disperse immersion cooling liquid from the reservoir onto the storage media.

25. A system for immersion cooling, the system comprising: a semiconductor die immersed within a reservoir of immersion cooling liquid; a storage media disposed above the reservoir and communicatively coupled to the semiconductor die; and a dispersion means configured to disperse immersion cooling liquid from the reservoir onto the storage media.

26. The system of claim 25, wherein the dispersion means is configured to disperse the immersion cooling liquid onto the storage media by spraying at least a portion of the immersion cooling liquid onto the storage media.

27. The system of claim 26, further comprising a pump operably coupled to the dispersion means, the pump configured to force immersion cooling liquid from the reservoir to the dispersion means.

28. The system of claim 26, wherein the dispersion means is located above the reservoir so that at least a portion of the sprayed immersion cooling liquid falls into the reservoir after spraying.

29. A system for immersion cooling, the system comprising: a semiconductor die immersed within a reservoir of immersion cooling liquid; and a storage media disposed at least partially within an immersion cooling froth and communicatively coupled to the semiconductor die, wherein the immersion cooling froth is located above the reservoir.

30. A method for immersion cooling, the method comprising: operating a semiconductor die in a reservoir of immersion cooling liquid; dispersing immersion cooling fluid onto a storage media, the storage media disposed above the reservoir and communicatively coupled to the semiconductor die; wherein: at least a portion of the dispersed immersion cooling fluid falls back into the reservoir after the step of dispersing; and the step of dispersing comprises spraying at least one of a contiguous stream of liquid, an aerated stream of liquid, liquid droplets, a mist, a froth, or a foam.