EP-4736590-A1 - ACTIVE-PASSIVE IMMERSION COOLING SYSTEM

Abstract

Liquid cooling apparatus and system for the immersion cooling of electronic devices including in particular servers and IT hardware nodes having an array of heat generating electronic components including for example microprocessors, GPUs, CPUs, RAM, motherboards etc. The present apparatus comprises at least one rotor adapted for creating a liquid flow stream localised to the electronic component(s) for the efficient and effective forced convection cooling according to an active cooling arrangement. The present arrangement is configured for both active and passive operation and is adapted specifically not to obstruct passive liquid flow adjacent an electronic component when the at least one rotor is not operational.

Inventors

• MIYOSHI, Mark

Assignees

• Submer Technologies SL

Dates

Publication Date

20260506

Application Date

20240626

Claims (20)

1. 1. Cooling apparatus to remove heat from a heat-generating electronic component immersed within a dielectric coolant liquid comprising: at least one heat-generating electronic component; at least one heat sink configured to receive thermal energy from a main face of the heat-generating electronic component and having a base and a plurality of heat transfer members each projecting from the base and terminating at respective terminal ends or edges, the members defining a least one side face of the heat sink extending between the base and the ends or edges, a terminal end face of the heat sink positioned opposed to the base and defined by terminal ends or edges; regions between the members defining flow ducts extending laterally across the heat sink between the base and the terminal end face; a support body having at least one mount region to receive and mount at least one rotor and an attachment region to attach the support body to the heat sink; at least one rotor rotatably mounted at the mount region; and at least one motor to drive rotation of the rotor at the support body and create at least one flow stream of the dielectric coolant liquid; wherein the support body is configured such that at least one rotor is positioned opposed to the at least one side face of the heat sink so as to direct the at least one flow stream through the flow ducts and laterally across the heat sink between the base and the terminal end face.
2. 2. The apparatus as claimed in claim 1 wherein the heat sink is provided at the main face of the heat-generating electronic component.
3. 3. The apparatus as claimed in claim 2 wherein the radiation members comprise a plurality of fins arranged in rows to define the liquid flow ducts extending between the fins, the fins and the base defining the heat sink as a generally block-shaped body.
4. 4. The apparatus as claimed in claim 2 wherein the radiation members comprise a plurality of elongate pins or fingers projecting from the base to define the liquid flow ducts extending between the pins or fingers, the base and pins or fingers defining the heat sink as a generally block-shaped body.
5. 5. The apparatus as claimed in claim 3 or 4 wherein the at least one rotor is positioned at the side face of the block-shaped body adjacent an entrance or exit end of the ducts.
6. 6. The apparatus as claimed in claim 2 wherein the heat sink comprises a heat pipe, heat-transfer device comprising at least one first module to mount to the at least one heatgenerating electronic component; a heat spreader module connected to the first module in internal fluidic communication; and a liquid contained within the heat pipe heat-transfer device and configured to circulate between the first module and the heat spreader module and to undergo phase change within the device including an evaporation and condensation cycle.
7. 7. The apparatus as claimed in claim 6 wherein the support body and the rotor are mounted at the heat spreader module.
8. 8. The apparatus as claimed in any preceding claim wherein the heat-generating electronic component comprises any one or a combination of • an integrated circuit; • an integrated circuit chip; • a motherboard; • random access memory (RAM); • a graphics processing unit (GPU); • a central processing unit (CPU).
9. 9. The apparatus as claimed in claim 8 wherein the at least one heat-generating electronic component is mounted at an electronic device comprising any one or a combination of • a computer entity; • a server; • a motherboard; • a printed circuit board comprising a plurality of electronic components; • an integrated circuit.
10. 10. The apparatus as claimed in any preceding claim wherein the rotor mount region comprises at least one aperture to at least partially accommodate and allow rotation of the at least one rotor.
11. 11. The apparatus as claimed in claims 1 or 2 wherein the rotor comprises not more than six blades or wherein the rotor comprises two to six, two to five, two to four or two or three blades projecting radially outward from a central boss.
12. 12. The apparatus as claimed in any preceding claim wherein the rotor is a propeller or an impeller.
13. 13. The apparatus as claimed in any preceding claim wherein the support body comprises a cover portion configured to sit over and about at least a part of the heat sink.
14. 14. The apparatus as claimed in claim 13 wherein the cover portion is configured to sit over the main face of the heat-generating electronic component so as to prevent or inhibit flow of the dielectric coolant liquid through the main face.
15. 15. The apparatus a claimed in any preceding claim wherein the rotor is positioned proximate and/or immediately adjacent the at least one side face of heat sink.
16. 16. An immersion liquid cooling assembly comprising: the apparatus as claimed in any preceding claim; and a container defining a chamber to contain a dielectric coolant liquid and at least one electronic device immersed within the liquid, the electronic device mounting the at least one heat-generating electronic component.
17. 17. The assembly as claimed in claim 16 wherein the electronic devices are arranged in a generally vertical orientation within the chamber such that a lengthwise first end of each electronic device is positioned closest to a trough of the chamber relative to a second lengthwise end of each electronic device positioned closest to upper region of the chamber; and wherein the cooling apparatus and in particular the rotor is positioned at or towards the first lengthwise end closest to the trough relative to the second lengthwise end of the electronic devices.
18. 18. The assembly as claimed in claim 17 wherein the at least one rotor is positioned between the heat sink and a base face of the container that, in part, defines the trough of the chamber.
19. 19. The assembly as claimed in any one of claims 16 to 17 comprising at least one liquid flow inlet and at least one liquid flow outlet provided at the container to allow a flow of the liquid to enter and exit respectively the chamber in direct contact with the electronic devices; and a cooling unit provided in fluidic communication with the chamber to cool the liquid and being provided in fluidic communication with at least one of said inlet and said outlet to form a fluid flow network to transfer heat energy from the heat-generating electronic components to the liquid.
20. 20. The assembly as claimed in claim 19 further comprising a liquid flow pump connected in fluidic communication with the inlet and/or the outlet of the container to drive a flow of the liquid to and from the chamber.

Description

Active-Passive Immersion Cooling System Field of invention The present invention relates to liquid cooling systems for the effective and efficient cooling of heat-generating electronic components and in particular, although not exclusively, to apparatus and method to cool IT components, servers, computational electronic devices and the like via direct submersion of such components and devices in a dielectric liquid coolant. Background The cooling of electronics, specifically IT components, servers, data storage devices and computational electronic devices having graphics and central processing units (GPUs and CPUs) has become a major technical challenge due to the ongoing development of smaller, faster, higher density and higher power capacity electronics. Computing devices produce heat as a by-product of operational processing. In datacentres, where thousands of such devices are located, the amount of heat generated can be extremely large. As the need for access to greater processing and data storage continues to expand, the density of server systems continues to increase, and the resulting thermal challenges present a significant practical obstacle. Conventional fan-based cooling systems require large amounts of power. Accordingly, the power demand to drive such systems increases significantly with the increased server densities. Immersion cooling of IT components is a relatively recent development. The operational hot electronics are submerged in direct contact with a dielectric (electrically insulating) coolant liquid that is circulated and cooled through the use of heat exchangers and the likes. Cooling of electronics enhances their performance, enabling higher processing speeds (for example the overclocking of CPUs) whilst reducing power consumption by minimising current leakage. The heat generated by the circuit is removed quickly and efficiently by the dielectric liquid directly at the heat source. However, there is a general need for continued improvement of the operational efficiency of existing liquid submersion cooling systems with regard the effectiveness of the cooling of the electronic components. Additionally, within single-phase immersion cooling, heat sinks are commonly used to dissipate heat generated by electronic components such as CPUs, GPUs, and power supplies. These heat sinks act passively within an immersion cooling system as typically there is no source of localized forced convection to accelerate the liquid through the heat sink. Due to the favourable thermal characteristics of existing immersion cooling dielectric liquids, passive heat sinks have proved to be more than adequate. However, as electronic devices and in particular heat generating electronic components continue to be developed and configured to operate at higher heat fluxes, there is a need for improved arrangements for efficient and effective cooling of such components. Summary of the Invention One objective of the present concept is to provide an active-passive immersion cooling system for electronic devices (having at least one heat generating electronic component) with improved heat transfer by use of forced convection of a dielectric cooling liquid relative to the heat generating electronic component. It is a specific objective to provide a cooling apparatus and a method for electronic components operable with both active and passive immersion cooling modes for enhanced energy usage, cooling efficiency and fault tolerance. Accordingly, an active-passive immersion cooling system is provided to be compatible with an otherwise passive immersion cooling system. The present concept is particularly advantageous to be removable/replaceable at new and existing passive cooling configurations. The present active-passive arrangement is provided by at least one rotor configured to be rotatably driven relative to a rotor housing and/or the electronic device/component to create and maintain a flow stream of the dielectric liquid past the electronic component/device so as to create an active forced convection cooling arrangement. The at least one rotor, optionally implemented as a propeller or impeller, is adapted to propel the liquid at relatively high velocity. Additionally, the rotor is configured such that an aperture at the rotor housing, within which the rotor is mounted, comprises a generally "open ’ cross sectional area such that a cross sectional region or size of the rotor (occupying the rotor housing aperture) is minimised and in particular is less than the surrounding "open ’ cross sectional area (not occupied by the rotor). Such an "open ’ cross sectional area is defined as the region not obstructed/obscured by the rotor (where the rotor is defined as a body comprising a central hub and rotor blades extending radially outward from the hub). In particular, it may be a feature of the rotor blades to comprise a relatively high aspect ratio i.e., to be longer and thinner relative to existing prior art fan blades c