Cooling systems for liquid immersion cooling of electronic components

Abstract

The present invention relates to a cooling system (1) for liquid immersion cooling of electronic components (2), the cooling system comprising: a container (3) which contains a liquid heat transfer fluid (4) in the interior, into which the electronic components (2) can be immersed, the container (3) having a gas space (5) above a surface (41) of the liquid heat transfer fluid (4), a heat exchanger device (6) for forming the liquid heat transfer fluid (4) in the gas space (5) of the container (3), wherein the cooling system (1) has a locking device (8) located on the container (3) for exchanging the electronic components (2), and the locking device (8) has a locking space (81) which is hermetically sealed relative to the gas space (5) of the container (5) to prevent gas exchange.

Description

Technical Field

[0001] The present invention relates to a cooling system for liquid immersion cooling of electronic components. Background Art

[0002] Cooling systems for liquid immersion cooling, such as two-phase immersion cooling systems, are active cooling solutions for electronic components that generate a lot of heat during operation. When the components are immersed in a heat transfer fluid, which typically has a relatively low boiling point, the heat generated by the electronic components can cause the surrounding liquid heat transfer fluid to evaporate, thereby dissipating heat from the electronic components. A condenser device liquefies the vaporized heat transfer fluid, which is then returned to a reservoir for cooling.

[0003] In the publication US 10 512 192 B2, a two-phase immersion cooling system including a cooling tank is disclosed. A condensation chamber is connected to the liquid fluid in the cooling tank, in which the gaseous fluid generated during the cooling process is condensed. In this case, a vapor redirection structure is arranged above the heat-generating electronic component inside the cooling medium in the cooling tank. The evaporated fluid is introduced into the condensation chamber through the vapor redirection structure for liquefaction.

[0004] However, if the immersion cooling system is opened to allow access to electronic components or for other system maintenance, some loss of heat transfer fluid occurs due to the escape of the vapor fluid into the environment. Reducing the amount of lost heat transfer fluid is environmentally friendly and can result in significant cost savings during operation of a two-phase immersion cooling system.

[0005] In this context, a cooling system for computer components is disclosed in the publication US 10 477 726 B1. Inside a pressure-controlled container, the internal pressure is reduced to 650 hPa. In the container, a heat-conducting, dielectric heat transfer fluid is in a liquid phase and a gas phase, the heat transfer fluid having a boiling point below 80°C at atmospheric pressure. Computer components at least partially immersed in the liquid phase of the fluid are arranged in the container. The dielectric electric phase fluid that has evaporated due to the heat generation of the computer components is condensed by a condenser to form a dielectric liquid phase fluid. An air lock on the pressure-controlled container is used to exchange computer components in an operating state, and the components to be exchanged can be replaced by a robotic device via the air lock.

[0006] Robotic arms in and outside the pressure controlled container are used to exchange components. If an electronic component does not function correctly, a removal sequence is initiated for this purpose. In this case, the internal arm removes the corresponding computer component and deposits it through the inner airlock door inside the airlock. Once this sequence is completed, the inner airlock door is closed, the airlock pressure is equalized to the outside atmosphere, and the outer airlock door is opened. Once the outer door has been opened, the external robotic arm system removes the component from the airlock.

[0007] Before the gas lock is opened to the outside environment, the interior of the gas lock can be purged with nitrogen and / or a different inert gas. This has the effect that the loss of dielectric fluid vapor remains low and, in particular, no air enters the interior of the container from the environment. Nevertheless, a gas exchange of the inert gas used is carried out from the gas lock into the interior of the cooling system. Summary of the invention

[0008] The object of the present invention is to develop a cooling system for liquid immersion cooling of electronic components in order to reduce the losses of heat transfer fluid.

[0009] The invention comprises a cooling system for liquid immersion cooling of electronic components. The cooling system comprises a container containing a liquid heat transfer fluid inside, into which the electronic components can be immersed, wherein the container has a gas space above the surface of the liquid heat transfer fluid. In addition, the cooling system has a heat exchanger device for forming the liquid heat transfer fluid in the gas space of the container. The cooling system has a locking device on the container for exchanging the electronic components. The locking device has a locking space, which is hermetically sealed relative to the gas space of the container to prevent gas exchange.

[0010] Furthermore, the cooling system can advantageously have a control device which is designed to regulate the operation of the fluid circulation, for example as a function of the temperature and pressure conditions of the heat transfer fluid in the container and / or in the locking device.

[0011] The invention is based on the observation that, due to the airtight seal, no air, water vapor or even inert gas can enter the container with the cooled electronic components. Therefore, during the cooling process, the gaseous heat transfer fluid is not contaminated by foreign gases. This is achieved by separating the locking space from the container and a barrier that prevents the exchange of substances with the gaseous heat transfer fluid. The locking device is sealed in a completely leak-proof manner with respect to the material exchange with the container. This is achieved in particular by liquid heat transfer fluid being used to seal the locking device with respect to the gas channel. In this case, the transfer area from the container to the locking space is filled with liquid heat transfer fluid.

[0012] The electronic components are arranged in a bath of a heat transfer fluid in a container in a manner suitable for cooling, the electronic components being cooled by evaporation of this liquid fluid. In this case, a proportion of non-condensable gases can be removed from the system before and / or during commissioning. In order to form the liquid heat transfer fluid, the heat exchanger device of the cooling system can be designed as a bundle of heat exchanger tubes in the gas space of the container. In this case, a plurality of tube bundles can also be arranged so as to be distributed in the gas space of the container.

[0013] The locking device is suitable for providing a component between an environment and the container in which there is virtually no pressure difference via a locking device that is hermetically sealed with respect to gas exchange, and thereby preventing or at least considerably reducing the penetration of air and other media into the system, as well as the loss of heat transfer fluid from the system. In this case, the locking device can also be designed to be detachable from the container. For example, the locking device can be designed as a module, which can be introduced into the container and can be removed again, and which module is immersed in the liquid heat transfer fluid with a certain immersion depth. For example, a square or rectangular four-sided module is suitable, which module is immersed in the container in a ready-to-use state through a lower opening into the liquid heat transfer fluid, and whose upper opening can be closed by a cover relative to the external environment.

[0014] The locking space of the locking device can also be filled with a heat transfer fluid from the container or a separate storage container. This is achieved, for example, by the gas pressure in the container being increased accordingly to such a level that, according to the principle of the connecting pipe, the liquid heat transfer fluid enters the locking space according to the pressure conditions and replaces the gas present therein. Due to the suitable pressure conditions of the external pressure and the internal pressure, the locking space can also be completely filled with liquid heat transfer fluid for exchanging electronic components. After the locking device is closed relative to the external environment, there is no outside air or any other foreign gas in the locking space.

[0015] The electronic components are arranged in a bath of heat transfer fluid in a container in a manner suitable for the pre-cooling requirements and are cooled by evaporation of this fluid. The monitoring and control of pressure, temperature, conductivity and all parameters relevant to the process are carried out by the control device through sensors.

[0016] A particular advantage is that by means of the locking device the cooling system can be designed in an optimized manner with regard to efficiency, losses of heat transfer fluid and moisture input into the system.

[0017] In a preferred embodiment of the invention, a partition can be arranged for gas-tight sealing of the lock space, said partition being immersed in the liquid heat transfer fluid to an immersion depth. This results in the creation of a siphon, which is formed by the liquid heat transfer fluid and seals the gas space in the container and the gas space of the lock space with respect to gas exchange.

[0018] Advantageously, the immersion depth of the partition can be designed to be variable. As a result, when the locking device is closed, the partition can be at least partially removed for simple further positioning of the electronic components in their operating position. The partition can be displaced, for example, or even removed by a folding mechanism.

[0019] In an advantageous embodiment of the invention, a loading system can be arranged in the container, whereby the electronic components can be conveyed from the locking device to the operating position for the exchange of said components. The loading system can comprise a robotic arm or a linear drive. With a suitable configuration of the device, the exchange of components can be carried out via a fully automatic loading system. Alternatively, gloves can also be arranged at a suitable container opening for exchanging the electronic components from the locking device to the operating position. Thus, according to the principle of a gas-tight glove box, loading can be carried out by means of manual access to the interior of the container.

[0020] In an advantageous embodiment of the invention, a storage device for the intermediate storage of electronic components can be provided in the locked space. When an additional or adjacent storage device is provided, the components to be exchanged can be accessed in a simple manner without opening the cooling system.

[0021] Advantageously, the additional heat exchanger device can be designed as a lock cooling system, which can specifically control the temperature of the heat transfer fluid located in the lock space. Therefore, the heat transfer fluid located in the lock space can be temperature-controlled separately from the entire circuit. As a result, possible residues of the gaseous heat transfer fluid can also be transferred to the liquid phase. The liquefaction of the vapor can be performed by an integrated or adjacent condenser. In addition, it is advantageous to keep the gas pressure low when opening the lock device to the outside by the cold heat transfer fluid in the lock space.

[0022] In an advantageous embodiment, the locking device and / or the container can have a degassing device, whereby non-condensable gases can be separated from the gaseous heat transfer fluid. In this way, a small proportion of gases penetrating the cooling system can also be removed from the cooling circuit.

[0023] Advantageously, the locking device can be filled with protective gas via the gas connection. In particular, interfering residual gases (such as, for example, ambient air) can be removed from the locking space by the inert gas.

[0024] Advantageously, a pressure balance tank can also be arranged on the container and / or on the locking device. The pressure balance tank can be used to precisely adjust the level of the liquid fluid phase in the gas space of the container and in the locking space. A degassing process in the locking space, for example after a locking process, can also be performed by such a device.

[0025] Advantageously, the container may be provided with an auxiliary heating system which serves as an aid to the evaporation of the heat transfer fluid.The device may perform pressure regulation of the cooling system independently of the operation of the electronic components or the cooling power of the heat exchanger device.

[0026] In an advantageous embodiment of the invention, the container can be designed as a pressure container operating under negative pressure and / or positive pressure. In order to lock the electronic components, in order to adjust the level of the liquid fluid level in the locking space, it may be necessary to adjust the pressure level relative to the ambient pressure of the air. Thus, both under negative and positive pressure, the cooling system can be adjusted in a variable manner relative to the surrounding atmosphere without negatively impairing or interrupting the operation.

[0027] By means of schematic diagrams, exemplary embodiments of the present invention are described in more detail:

[0028] in:

[0029] FIG1 shows a schematic oblique view of a cooling system,

[0030] FIG. 2 shows a schematic front view of a cooling system with an advantageous embodiment of a locking device, and

[0031] FIG. 3 shows a schematic front view of a cooling system with another embodiment of a locking device.

[0032] In all the figures, components that correspond to each other are provided with the same reference numerals.

[0033] 1 shows a schematic oblique view of a cooling system 1 for liquid immersion cooling of electronic components 2. The cooling system 1 comprises a container 3 and a locking device 8 for exchanging electronic components 2. The liquid dielectric heat transfer fluid 4 located in the interior of the container 3 extends into a locking space 81 of the locking device 8. The liquid heat transfer fluid 42 located in the locking space 81 forms a gas-tight seal with the partition 82 relative to the gas space 5 of the container 3 to prevent gas exchange. For gas-tight sealing, the partition 82 is immersed in the liquid heat transfer fluid 4 and thus separates the locking space 81 from the gas space 5 of the container 3 on the gas side.

[0034] In the cooling system 1, an automatic loading system (not shown in FIG. 1) can be arranged in the container 3, by which the electronic components 2 can be transported from the locking device 8 to the operating position 31 for exchanging the components. The electronic components 2 can be transported by a gripper arm of a robot or a linear transport system, which collects the electronic components 2 to be exchanged from the operating position 31 in an automated manner and, for example, deposits them in a storage device 9 of the locking device 8. In reverse order, the electronic components 2 to be mounted, which are ready for operation, are collected from the storage device 9 by the loading system and transferred to the operating position 31. The locking device 8 itself can also be operated from the outside by an automated device.

[0035] In order to exchange the electronic component 2, the cover 83 of the locking device 8 is opened, and the component 2 is stored in the storage device 9 in the locking device. From there, the defective component is moved to the outside via the locking device. Before opening the cover 83, an inert gas can be introduced into, for example, the locking space 81 via the gas connection 11, and then, via the degassing device 10, the inert gas is at least partially discharged together with a certain proportion of the gaseous heat transfer fluid located in the locking space 81. This leads to a purification process of the locking space 81, so that when the cover 83 is opened, no gaseous heat transfer fluid or only a small proportion of the gaseous heat transfer fluid escapes from the locking device. After closing the cover 83, the locking space 81 can be free of ambient air by a re-purification process with an inert gas. If a pressure balance in the locking device is required relative to the atmospheric pressure of the environment, the pressure balance tank 13 can generate the required pressure in the gas space 5. Similarly, during the locking process, pressure balance can be implemented via an auxiliary heating system 12, which is arranged in the liquid heat transfer fluid 4 in the container 3. In this case, during the lockout period, the auxiliary heating system 12 boosts the cooling system 1, which otherwise operates at negative pressure, and increases the internal pressure in the gas space 5 and thus produces the required pressure balance. As a result, the cooling power of the heat exchanger device 6 is not further affected. Nevertheless, this can also be used for pressure regulation.

[0036] FIG2 shows a schematic front view of a cooling system 1 with an advantageous embodiment of a locking device 8. A locking cooling system 7 is arranged in the locking device 8, which liquefies residual components of the gaseous heat transfer fluid and further reduces the temperature of the liquid heat transfer fluid 4 in the locking space 42. As a result, in particular, in the locking device 8, the partial pressure of the heat transfer fluid is reduced during the locking process of the electronic component 2. If a positive pressure is generated in the gas space 5, the fluid surface 43 in the locking device 8 rises. As a result, the gas volume in the locking space 81 is reduced. Therefore, when the cover 83 is opened, a reduced gas exchange with the ambient air occurs, or when the locking space 81 is completely filled, no gas exchange occurs.

[0037] FIG3 shows a schematic front view of a cooling system 1 with another embodiment of a locking device 8. In this locking device, the fluid surface 41 in the gas space 5 can be at a higher level relative to the fluid surface 43 in the locking space 8, and vice versa, depending on whether negative pressure or positive pressure prevails in the gas space 5 during the cooling process. The cover 83 closed relative to the outside is now placed directly on the liquid heat transfer fluid 42 in the locking device 8. After the locking process, the cover 83 completely seals the locking space 81 relative to the outside air. After opening the cover 83, the electronic components 2 can now be exchanged directly. In this case, a simple loading or emptying of the easily accessible storage device 9 can also be performed. After the locking process, the outside air is immediately discharged through the cover 83. For this purpose, a small closable vent can be arranged in the cover 83.

[0038] Reference numerals

[0039] 1 Cooling system

[0040] 2 Electronic components

[0041] 3 Container

[0042] 31 Operating position

[0043] 4 Liquid heat transfer fluid

[0044] 41 Fluid Surfaces in Gas Space

[0045] 42 Liquid heat transfer fluid in locked space

[0046] 43 Locking the fluid surface in space

[0047] 5 Gas space

[0048] 6 Heat exchanger device

[0049] 7 Additional heat exchanger installation, lock cooling system

[0050] 8 Locking device

[0051] 81 Lock Space

[0052] 82 Bulkhead

[0053] 83 Cover

[0054] 9 Storage Devices

[0055] 10 Degassing device

[0056] 11 Gas connections

[0057] 12 Auxiliary heating system

[0058] 13. Pressure balance tank

Claims

1. A cooling system (1) for liquid immersion cooling of electronic components (2), comprising: A container (3) containing a liquid heat transfer fluid (4) in the interior, into which the electronic component (2) can be immersed, wherein the container (3) has a gas space (5) above the surface (41) of the liquid heat transfer fluid (4), a heat exchanger device (6) for forming a liquid heat transfer fluid (4) in the gas space (5) of the container (3), The cooling system (1) has a locking device (8) on the container (3) for exchanging the electronic component (2). It is characterized in that The locking device (8) has a locking space (81) which is hermetically sealed relative to the gas space (5) of the container (3) to prevent gas exchange; a partition (82) is arranged for hermetically sealing the locking space (81), the partition being immersed in the liquid heat transfer fluid (4) to an immersion depth.

2. The cooling system (1) according to claim 1, characterized in that The immersion depth of the partition (82) is designed to be variable.

3. The cooling system (1) according to claim 1, characterized in that A loading system is arranged in the container (3), by means of which the electronic components (2) can be transported from the locking device (8) to the operating position (31) for the exchange of the components.

4. The cooling system (1) according to claim 1, characterized in that A storage device (9) for the intermediate storage of electronic components (2) is arranged in the locking space (81).

5. The cooling system (1) according to claim 1, characterized in that The further heat exchanger device (7) is designed as a lock cooling system which can specifically control the temperature of the heat transfer fluid (42) located in the lock space (81).

6. The cooling system (1) according to claim 1, characterized in that The locking device (8) and / or the container (3) has a degassing device (10), by means of which non-condensable gases can be separated from the gaseous heat transfer fluid.

7. The cooling system (1) according to claim 1, characterized in that The locking device (8) can be filled with protective gas via the gas connection (11).

8. The cooling system (1) according to claim 1, characterized in that A pressure equalization tank (13) is also arranged on the container (3) and / or on the locking device (8).

9. The cooling system (1) according to claim 1, characterized in that The container (3) is provided with an auxiliary heating system (12) which serves to assist in the evaporation of the heat transfer fluid (4).

10. The cooling system (1) according to any one of claims 1 to 9, characterized in that The container (3) is designed as a pressure vessel operating under negative pressure and / or positive pressure.

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