Cooling system for the liquid immersion cooling of electronic components

Abstract

The invention relates to a cooling system (1) for the liquid immersion cooling of electronic components (2), comprising - a container (3) having a container wall (31), the interior of said container being fillable with two-phase heat transfer fluid (4) into the liquid phase of which electronic components (2) can be immersed, wherein the container (3) has a gas chamber (5) above the surface (41) of the liquid heat transfer fluid (4), and wherein the container wall (31) has at least one cutout (32) as a passage point for an electric connection line (7), - a heat exchanger device (6) in the gas chamber (5) of the container (3) for forming liquid heat transfer fluid (4), characterised in that the cutout (32) is covered in a fluid-tight manner by an elastic connection flange (8) by means of which the electric connection line (7) is guided into the container (3).

Description

[0001] Description

[0002] Cooling system for liquid immersion cooling of electronic components

[0003] The invention relates to a cooling system for liquid immersion cooling of electronic components according to the preamble of claim 1.

[0004] Liquid immersion cooling systems, such as two-phase immersion cooling systems, are an active cooling solution for electronic components that generate a lot of heat during operation. When the components are immersed in a two-phase heat transfer fluid, which usually has a low boiling point, the heat generated by the electronic component can evaporate the surrounding liquid heat transfer fluid, thereby removing heat from the electronic component. A condenser device liquefies the gaseous heat transfer fluid, which is then returned to the reservoir for cooling.

[0005] A two-phase immersion cooling system with a cooling basin is known from US Pat. No. 10,512,192 B2. A condensation chamber, in which the gaseous fluid produced during the cooling process is condensed, communicates with the liquid fluid in the cooling basin. A vapor diversion structure is arranged above the heat-generating electronic components located within the cooling medium in the cooling basin. The vaporized fluid is directed into the condensation chamber for condensation by means of the vapor diversion structure. The condensation chamber is located entirely within the cooling basin. Only the supply and discharge lines for the fluid contained in the cooling tubes pass through the cooling basin wall.

[0006] Heat-generating components are any electrical components that generate a significant amount of heat and therefore require active cooling, such as computer processors, hard drives, or similar components. These components are supplied with electrical power via power feedthroughs. In certain parts of the cooling system that are not pressurized, inexpensive cable feedthroughs can also be used, which do not need to be hermetic. However, other areas place greater demands on the electrical supply.

[0007] In this context, a cooling system for computer components is known from US Pat. No. 1,0477,726 B1. A pressure-controlled container contains a heat-conducting, dielectric heat transfer fluid in liquid and gaseous phases, which has a boiling point below 80°C at atmospheric pressure. Computer components are arranged in the container and are at least partially immersed in the liquid phase of the heat transfer fluid. A condenser condenses the dielectric gas-phase fluid evaporated by the heat generated by the computer components into a dielectric liquid-phase fluid. The internal pressure in the pressure-controlled container is reduced to as low as 650 hPa. By controlling the pressure in the container at which the system operates, the user can influence the temperature at which the dielectric fluid evaporates. This allows for increased cooling performance.Operating a computer system within a pressure-controlled vessel at an operating pressure that differs from ambient pressure usually requires a design modification of the system as a whole. The power supply is designed to include various electrical inputs that interact to form a power distribution system. An example described is a 415V input to a main breaker, which is then distributed to a series of power modules that convert the 415V AC input into a 12V DC output.

[0008] A support system on which computer components are arranged is designed to serve as an intermediary between the electrical and communication systems and the computing equipment.

[0009] Computer components are attached directly or indirectly to the mount and held in a stationary position. The design of the mounting system and the electrical power supply must be adapted based on the specific requirements of the respective application.

[0010] The invention is based on the object of developing a cooling system for liquid immersion cooling of electronic components with regard to the electrical energy supply.

[0011] The invention is defined by the features of claim 1. The further dependent claims relate to advantageous embodiments and developments of the invention.

[0012] The invention includes a cooling system for liquid immersion cooling of electronic components. The cooling system comprises a container with a container wall, which can be filled internally with a two-phase heat transfer fluid, into whose liquid phase electronic components can be immersed. The container has a gas space above the surface of the liquid heat transfer fluid. The container wall has at least one recess as a passage point for an electrical connection line. The cooling system also comprises a heat exchanger device in the gas space of the container for forming liquid heat transfer fluid. According to the invention, the recess is covered in a fluid-tight manner by an elastic connection flange, by means of which an electrical connection line is passed into the container.

[0013] Such connection flanges provide passages for electrical cables that supply the cooling system with electrical power. The recesses can be polygonal, square, or round holes in the tank wall. The tank wall can be thickened by a hole or reinforced with an additional flange. The material and thickness of a flange significantly determine the support function and stability of the structure in conjunction with the tank wall. For example, steel, with a plate thickness sufficiently thick to increase stability, is a suitable material.

[0014] Within the scope of the invention, elastic connecting flanges can be fully elastic bushings or consist of combinations of rigid and elastic sections.

[0015] The flexible connection flange can cover the recess in the tank wall in a fluid-tight manner from the outside or inside. This allows tensile and compressive loads on the flexible connection flange to be taken into account and adjusted. Multiple connection flanges for multiple feedthroughs, arranged on one or both sides of the tank wall, are also being considered.

[0016] The electrical connection cable can be constructed in multiple pieces through the connection flange into the interior of the container, allowing electrical connection to further conductors leading to the electronic components. The electrical connection cable can also consist of several parallel conductors and also have branches. Electrical connections and connectors can be designed as terminals or screw connections. The additional conductors can be installed in the container, for example, as floating busbars and thus movable along their length. Within the meaning of the invention, the term "electrical connection cable" also encompasses systems for signal and data transmission, such as bus systems.

[0017] The heat exchanger device in the gas space consists of at least one tube bundle comprising several mutually arranged heat exchanger tubes, which can be fixed in at least one tube plate. The at least one tube plate of a tube bundle can be formed as part of the vessel wall. The two-phase heat transfer fluid, also referred to as refrigerant, represents the outer fluid in the vessel, in whose liquid portion the electronic components are immersed. The inner fluid located in the heat exchanger tubes is a single-phase heat transfer medium, for example, process water.

[0018] In the container, the electronic components are arranged in a suitable manner in a bath of liquid heat transfer fluid, which is cooled by evaporation of the liquid fluid. In the embodiment according to the invention, several connection flanges can also supply the computing components and immersion cooling devices, as well as the associated power supplies, network connections, wiring connections, and the like, within the container via recesses in the container wall.

[0019] In this context, it may also be advantageous to combine power, water, vacuum and network connections in a bundle of lines in elastic connection flanges in order to minimize the penetrations into the vessel and to reduce the risk of leaks, especially when the system is under vacuum or overpressure during operation.

[0020] In advantageous embodiments of the cooling system according to the invention, the elastic connecting flange can have an entry point for the electrical connection cable and an exit point into the container. Appropriate sealing measures must be provided along the passage of the electrical connection cable between the entry point and the exit point to ensure a hermetic seal of the container wall.

[0021] In an advantageous embodiment, the connecting flange can rigidly fix the electrical connection cable at the entry point, and an elastic part of the connecting flange can be formed at the exit point, covering the recess in the container wall. The connecting flange exerts its elastic effect against the container wall, allowing the electrical connection cable to be guided through the container wall and further along the container with corresponding flexibility, particularly with respect to thermally induced length changes or mechanical influences.

[0022] In an advantageous embodiment of the invention, the elastic part of the connecting flange can comprise a flexible tube, by means of which the recess is covered in a fluid-tight manner. The flexibility of a tube can be determined by the elastic material used or by its geometry and wall thickness.

[0023] Advantageously, the elastic part of the connection flange can be a corrugated pipe. Corrugated pipes can accommodate axial length changes as well as react to non-axial forces. Corrugated pipes made of metal are particularly suitable, as they can be connected to the tank wall at the end face by means of appropriately designed connection surfaces. Metal corrugated pipes are preferably fixed to the tank wall with welded joints or screw connections. Corrugated pipes made of plastic or rubber, for example, are suitable for adhesive connections.

[0024] In a preferred embodiment of the invention, the connecting flange can rigidly fix the electrical connection cable at the entry point using an electrical insulating material. This rigid fixation, in particular, assumes the sealing function against the escape of heat transfer fluids and against the ingress of air.

[0025] Advantageously, the electrical insulating material can be made of multi-component resin or ceramic. Resins are easy to process, form a fluid-tight seal around the electrical connection cable, and, once cured, exhibit satisfactory stability against mechanical stress.

[0026] In an advantageous embodiment of the invention, the electrical connection cable can enter the container at the exit point without contact. This allows the elastic part of the connection flange to exert its full effect against the container wall. The electrical connection cable has no contact with the elastic section.

[0027] In an advantageous embodiment of the invention, the elastic connecting flange can be connected to the container wall by welding, screwing, or gluing. Compared to other joining methods, a welded connection provides a particularly stable material bond.

[0028] Screw connections, on the other hand, can be easily replaced.

[0029] Advantageously, a stop device can limit the movement of the electrical connection cable. A stop is used in particular to ensure that the elastic range of the connection flange is not exceeded, thus preventing leakage.

[0030] In addition, the anchor device can be equipped with an additional contact sensor that monitors excessive expansion of the electrical connecting cable. To prevent excessive expansion, the cause of excessive heating can be counteracted by shutting off the power or reducing the voltage. In any case, such safety devices are intended to prevent further expansion beyond the elastic range of the connecting flange.

[0031] Advantageously, the recess with the connection flange can be arranged below the surface of the liquid heat transfer fluid on the vessel wall. Since the electronic components are immersed in the liquid phase for cooling during operation of the cooling system, it is advantageous to arrange the elastic connection flanges as feedthroughs for electrical cables at approximately the same level in the liquid fluid. This enables direct and material-saving electrical supply. However, for structural reasons, it is also possible to arrange connection flanges at any suitable location on the vessel.

[0032] Embodiments of the invention are explained in more detail with reference to the schematic drawings.

[0033] Showing:

[0034] Fig. 1 is a schematic side view of a cooling system, and

[0035] Fig. 2 a schematic detailed view of an elastic connecting flange.

[0036] Corresponding parts are provided with the same reference numerals in all figures. Fig. 1 shows a schematic side view of a cooling system 1 for liquid immersion cooling of electronic components 2. The cooling system 1 comprises a container 3 with a container wall 31, the interior of which can be filled with a two-phase heat transfer fluid. The two-phase heat transfer fluid represents the outer fluid located in the container 3, with a liquid heat transfer fluid portion 4, in which the electronic components 2 are immersed, and a gaseous heat transfer fluid portion 5. In the container 3, a heat exchanger device 6 consisting of tube bundles is arranged in the gas space 5 of the container 3 for forming liquid heat transfer fluid 4. In the left-hand part of the image in Figure 1, a connecting flange 8 for passing through an electrical connecting cable 7 is mounted on the container wall 31.The connecting flange 8 hermetically covers a recess 32, in this case a round hole. The connecting line 7 consists of several sections that are joined together immediately after passing into the container 3. Suitable sections of the connecting line 7 facilitate the installation of the connecting flange 8 on the container wall 31.

[0037] Fig. 2 shows a schematic detailed view of an elastic connection flange 8 of the cooling system. The container wall 31 has a recess 32 in the form of a round hole as a passage point for the electrical connection cable 7. In this embodiment, the recess 32 is completely covered in a fluid-tight manner by an elastic connection flange 8. The electrical connection cable 7 is guided into the container 3 through the connection flange 8. The electrical connection cable 7 enters the connection flange 8 through an inlet point 81 and continues into the container 3 at an outlet point 82. At the inlet point 81, the connection cable 7 is rigidly fixed by means of an electrical insulating material 83 in the form of a resin block. A flexible pipe 84 in the form of a corrugated metallic pipe is connected to the resin block up to the outlet point 82.The corrugated pipe 84 is firmly connected to the container wall 31 at the end face, for example by welding.

[0038] At the exit point 82, the electrical connecting cable 7 enters the container 3 without contact. Further along, a stop device 9 limits the mobility of the electrical connecting cable 7, particularly in the longitudinal expansion direction L. In the longitudinal expansion direction L, an electrical connecting cable 7 experiences the greatest change in length as a function of temperature.

[0039] List of reference symbols

[0040] 1 cooling system

[0041] 2 electronic component

[0042] 3 containers

[0043] 31 Container wall

[0044] 32 recess

[0045] 4 liquid heat transfer fluid

[0046] 41 Surface of the liquid fluid in the container

[0047] 5 gaseous heat transfer fluid, gas space

[0048] 6 Heat exchanger device

[0049] 7 electrical connection cable

[0050] 8 Connection flange

[0051] 81 Entry point of the electrical connection cable

[0052] 82 Exit point of the electrical connection cable

[0053] 83 electrical insulating material

[0054] 84 elastic part of the connecting flange, flexible pipe, corrugated pipe

[0055] 9 Anchor device

[0056] L Length expansion direction

Claims

Patent claims 1 . Cooling system (1) for liquid immersion cooling of electronic components (2), comprising - a container (3) with a container wall (31) which can be filled inside with a two-phase heat transfer fluid (4), in the liquid phase of which electronic components (2) can be immersed, wherein the container (3) has a gas space (5) above the surface (41) of the liquid heat transfer fluid (4), and wherein the container wall (31) has at least one recess (32) as a passage point for an electrical connection line (7), - a heat exchanger device (6) in the gas space (5) of the container (3) for forming liquid heat transfer fluid (4), characterized in that the recess (32) is covered in a fluid-tight manner by an elastic connecting flange (8) by means of which the electrical connecting line (7) is guided into the container (3).

2. Cooling system (1) according to claim 1, characterized in that the elastic connecting flange (8) has an entry point (81) of the electrical connecting line (7) and an exit point (82) into the container (3).

3. Cooling system (1) according to claim 2, characterized in that the connecting flange (8) rigidly fixes the electrical connection line (7) at the inlet point (81) and an elastic part (84) of the connecting flange (8) is formed at the outlet point (82), which part covers the recess (32) of the container wall (31).

4. Cooling system (1) according to claim 3, characterized in that the elastic part (84) of the connecting flange (8) has a flexible tube by means of which the recess (32) is covered in a fluid-tight manner.

5. Cooling system (1) according to claim 4, characterized in that the elastic part (84) of the connecting flange (8) is a corrugated pipe.

6. Cooling system (1) according to one of claims 3 to 5, characterized in that the connecting flange (8) rigidly fixes the electrical connection line (7) at the inlet point (81) by means of an electrical insulating material (83).

7. Cooling system (1) according to claim 6, characterized in that the electrical insulating material (83) consists of multi-component resin or ceramic.

8. Cooling system (1) according to one of claims 2 to 7, characterized in that the electrical connection line (7) enters the container (3) at the outlet point (82) without contact.

9. Cooling system (1) according to one of claims 1 to 8, characterized in that the elastic connecting flange (8) is connected to the container wall (31) by welding, screwing or gluing.

10. Cooling system (1) according to one of claims 1 to 9, characterized in that a stop device (9) limits the mobility of the electrical connection cable (7).

1. Cooling system (1) according to one of claims 1 to 10, characterized in that the recess (32) with the connecting flange (8) is arranged below the surface (41) of the liquid heat transfer fluid (4) on the container wall (31).

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