Server module extension block

Abstract

The invention relates to a server module extension block (20) for use in a hardware immersion cooling system (1). The server module extension block (20) comprises an inner space (25) configured to contain and transmit cooling fluid, an inlet side (21) comprising one or more inlet openings (22) configured to receive cooling fluid into the inner space (25), and a discharge side (23) comprising one or more discharge openings (24) configured to discharge cooling fluid from the inner space (25). The discharge side (23) is connected to or is configured to be connected to a server module (10).

Description

[0001] Server module extension block

[0002] TECHNICAL FIELD

[0003] The invention relates to server module extension block for use in a hardware immersion cooling system, an assembly of such a server module extension block and a server module, and a method of loading a hardware immersion cooling system.

[0004] BACKGROUND

[0005] Data centres comprise hardware racks in which a plurality of server modules can be placed. Server modules are also known as server cassettes or chassis. A server module may comprise all sorts of heat generating electrical components, such as server memory boards, hard disks, processors, switches, power units etc. Server modules typically are plate shaped, i.e. have a substantially rectangular, flat shape. The hardware racks are configured to receive a plurality of server modules in parallel next to each other.

[0006] When in operation, the electrical components consume electrical energy and produce heat. To prevent overheating and ensure optimal operation, the server modules need to be cooled during operation. Cooling may be achieved by air-cooling.

[0007] Alternatively, cooling may be achieved by immersion cooling. Immersion cooling is a method to cool the server modules by submerging the server modules in a cooling fluid, e.g. a liquid, which absorbs and transfers heat away from the electrical components. The server modules have an open structure, configured to accommodate the cooling fluid to flow along the electrical components. The cooling fluid is a di-electric (electrically non- conductive) liquid, making it safe for submerging electrical components.

[0008] Examples of such systems are provided in US2019 / 281727A1 , W02023 / 084052A1 , US2020 / 333858A1 and US2020 / 281093A1.

[0009] Fig. 1 shows an example of an immersion hardware rack, also referred to as a hardware immersion cooling system 1 . A hardware immersion cooling system 1 typically comprises a liquid tight tank 2 which can be filled with a dielectric cooling fluid. The tank 2 may comprise a plurality of receiving slots 3, each configured to receive a server module 10. An example of a server module 10 is shown in Fig.’s 2a and 2b. Each receiving slot 3 is configured to receive a server module 10 in a vertical orientation. The tank 2 comprises an open top side, allowing the server modules 10 to be inserted and removed from the receiving slots 3 in a vertical orientation. The hardware immersion cooling system 1 may comprise one or more tank lids 9 to open and close the open top side of the tank 2. In operation, the hardware immersion cooling system 1 is filled with dielectric cooling fluid such that the server modules 10 are at least partially immersed when positioned in the respective receiving slot 3.

[0010] Fig. 2a shows a server module 10 comprising one or more lifting connectors 11. The lifting connectors 11 are positioned on a top side 14 of the server module 10 and can be attached to a lifting mechanism of a service trolling for lifting and lowering the server modules out of and in to the hardware immersion cooling system 1 . The lifting connectors 11 are shown as a D-shape ring, but it will be understood that many alternative embodiments of lifting connectors 11 may be used. The top side 14 is defined as the side of the server module 10 facing upwards when positioned in a receiving slot 3.

[0011] Fig. 2b shows an open view of the interior of a server module 10 showing a plurality of electrical components 12, including heat generating electrical components, such as server memory boards, hard disks, processors, switches, power units etc. The electrical components 12 are positioned on the inside of the server module 10, protected by two panels 16 (front panel and back panel, only one of which is shown in Fig. 2a) and two side panels 18 (only one of which is shown in Fig. 2a). The server module 10 further has a profiled bottom side or base 15, i.e. it may comprise protrusions forming legs 17 which, once inserted, interact with supports provided in the tank 2 to hold the server module 10 in place.

[0012] The bottom side or base 15 of the server module 10 is opposite the top side 14, i.e. the bottom side or base 15 is the side of the server module 10 facing downwards when positioned in a receiving slot 3.

[0013] The hardware immersion cooling system 1 is further arranged to circulate the dielectric cooling fluid through the tank 2, along and through the server modules 10 and the electrical components 12 comprised by the server modules 10. A heat exchanger (not shown) is provided to reduce the temperature of the cooling fluid received from the tank 2 and circulate the hence obtained cooled cooling fluid back into the tank 2.

[0014] The warmed cooling fluid is typically removed from the tank 2 at or near the top of the tank 2, for instance by means of a weir. The cooled cooling fluid is typically (re-) introduced into the tank 2 at or near the bottom of the tank 2. To ensure optimal distribution of the cooling fluid throughout the tank 2 and over the plurality of server modules 10, the hardware immersion cooling system 1 may comprise a flow distribution system 4, an example of which is schematically shown in Fig. 3a. The flow distribution system 4 shown comprises a plurality of flow bars 5 running along the bottom of the tank 2. Each receiving slot 3 may have an associated flow bar 5. Each flow bar 5 may have a plurality of flow distribution outlets 6 to discharge cooling fluid into the tank 2 and into the server. According to an alternative, the flow distribution system is formed by a flow issuing surface stretching along the bottom of the tank 2, the flow issuing surface comprising a plurality of flow distribution outlets 6, like in a shower head.

[0015] The hardware immersion cooling system 1 is designed to allow server modules 10 to be inserted and removed when needed, for instance for maintenance purposes or when server modules 10 are due to be replaced. This is a delicate and time-consuming process. To remove a server module 10, cables need to be disconnected from the server module 10 and the server module 10 needs to be lifted vertically from the tank 2, for instance with the aid of a service trolley comprising lifting means. Care needs to be taken to prevent spilling cooling fluid.

[0016] Hardware immersion cooling systems according to the prior art haves several drawbacks.

[0017] Firstly, in practice, the process of inserting and removing server modules 10 is further complicated by the fact that server modules 10 do not have standardized dimensions. The tank 2 is dimensioned to receive server modules 10 with a predefined maximum height (height measured when the server modules are in the receiving slots in vertical orientation, i.e. from bottom side 15 to top side 14), but in practice server modules 10 have different heights. Server modules 10 of variable height have misaligned interfaces on the top of the tank 2. This is shown by way of example in Fig. 3a. The top sides 14 of the server modules 10 may be either on or under the liquid fill level of the tank 2. This presents operators with uneven interface locations and so forms a barrier to efficient working. It also means that for those server modules 10 under the liquid fill level the interfaces are wet and may affect the materials compatibility of connectors (particularly the case for connector bodies, polymers), signal integrity due to liquid infiltration to the cables and so performance degradation, and finally loss of liquid from the tank 2 due to capillary rise syphoning of the liquid from the wetted cable. Secondly, as described, a server module comprises several heat generating electrical components. However, not all components generate the same amount of heat. Thus, those parts of the server module comprising components generating relatively much heat require more cooling duty, i.e. more cooling fluid, than other parts of the server module. Typically, flow distribution systems are not able to accommodate for that.

[0018] Thirdly, flow by-pass is another drawback associated with hardware immersion cooling systems according to the prior art. Part of the cooling fluid flowing through the flow distribution outlets may flow around the server modules, instead of through the interior of the server module 10, defined by the front panel and back panel 16 and the two side panels 18. The contribution of by-pass flow to the cooling is very limited. This contributes to energy losses of the hardware immersion cooling system.

[0019] SUMMARY

[0020] The object is to provide a hardware immersion cooling system and / or server modules that overcome at least one of the disadvantages associated with the prior art. In particular, the object is to provide for an improved management of the flow interface between the flow distribution system and the server modules.

[0021] The object is solved by a server module extension block for use in a hardware immersion cooling system, wherein the server module extension block comprises

[0022] - an inner space configured to contain and transmit cooling fluid,

[0023] - an inlet side comprising one or more inlet openings configured to receive cooling fluid into the inner space,

[0024] - a discharge side comprising one or more discharge openings configured to discharge cooling fluid from the inner space, wherein the discharge side is connected to or is configured to be connected to a server module.

[0025] By providing such a server module extension block several advantages are obtained.

[0026] In the first place, the height of the server module extension block may be selected such that the top of the server module is located at a preferred height or level, facilitating cable management and servicing.

[0027] Secondly, the server module extension block may advantageously be used for improved management of the flow interface between the flow distribution system (i.e. the flow bar) and the server modules. The server module extension block allows for precision cooling between different server modules and between different parts (columns) within the server module.

[0028] The server module extension block allows for flow redistribution of cooling fluid over different parts of the server module. The flow redistribution means allow to redistribute the cooling fluid such that areas of the server module requiring relatively high cooling duty receive more cooling fluid than areas of the server module requiring low cooling duty.

[0029] Furthermore, by-pass of cooling liquid may be reduced, as the inlet openings positioned on the inlet side of the server module extension block may be positioned closer to corresponding outlets of the flow distribution system of the hardware immersion cooling system, or even in direct contact therewith.

[0030] The discharge side is connected to or is configured to be connected to a base of a server module 10. The connection between the server module and the server module extension block is to form a fluid connection, preferably a direct fluid connection, between the inner space and the interior of the server module. The interior of the server module is the space between the front panel, back panel and side panels in which the heat generating electrical components are located.

[0031] It is noted that the dimensions and shape of the server module, including the base of the server module are standardized to allow server module from different manufacturers to be suitable to be inserted into hardware immersion cooling systems. Therefore, a skilled person would have little difficulty in recognizing a server module extension block suitable for being connected to a server module. The dimensions and shape of the discharge side of the server module extension block are such to allow the discharge side to be connected to the server module, in particular the base of the server module.

[0032] The discharge side of the server module extension block may be formed with protrusions, depressions and other irregularities that are mechanically compliant to the shape of the base of the server module to form a tight and closed connection.

[0033] The cooling fluid may be a dielectric cooling fluid. The cooling fluid may be cooling liquid, particularly a dielectric cooling liquid. The flow distribution system is a system that extends along the bottom of the tank and comprises flow distribution outlets distributed over the bottom to ensure optimal distribution of the cooling fluid throughout the tank and over the plurality of server modules. The flow distribution system may comprise a plurality of flow bars running along the bottom of the tank. Each receiving slot may have an associated flow bar. Each flow bar may have a plurality of flow distribution outlets to discharge cooling fluid into the tank and into the server. The flow distribution system may also be formed by a flow issuing surface stretching along the bottom of the tank, the flow issuing surface comprising a plurality of flow distribution outlets, like in a shower head. The flow distribution outlets are facing upwards.

[0034] According to an embodiment the server module extension block is configured to be mechanically connected to a server module.

[0035] The server module extension block may comprise one or more connection parts, configured to connect to corresponding connection parts of a server module.

[0036] The server module extension block can be mechanically connected to the server module with suitable connectors, e.g. with push-fit fixings, a male / female circular interface with check-valve or butterfly valve, opened if / when the male part enters the female part by direct mechanical action.

[0037] The connection may comprise two mating connection parts, where one connection part is comprised by the server module extension block and a second connection part is comprised by the server module, wherein the first and second part are configured to be mechanically connected. The first part and second part may together form a push-fit connection, a male / female connection or any other suitable connection.

[0038] The advantage of such an embodiment is that the server module extension block moves with the server module when it is placed, removed and relocated in the tank, thereby making use of the server module extension block easy once it is connected to the server module.

[0039] According to an embodiment the server module extension block is configured to form a direct fluid connection between the flow distribution system and the server module extension block. According to an embodiment the server module extension block comprises inlet openings configured to be aligned with respective flow distribution outlets in the flow distribution system and to form a direct fluid connection between a flow distribution system and the server module extension block.

[0040] The term direct fluid connection is used to indicate that no cooling fluid may leak causing fluid by-pass. The direct fluid connection preferably is a leakproof fluid connection.

[0041] This may provide for a tight and good integrity seal between the flow distribution system and the server module extension block, thereby preventing by-pass.

[0042] The inlet side of the server module extension module preferably makes a direct fluid connection to the flow distribution system, e.g. a flow bar manifold, to prevent bypass.

[0043] Preferably, the fluid connection between the inlet side and the one or more flow distribution outlets is formed by one or more parallel, direct fluid connections, preventing leakage of cooling fluid which could by-pass the server module.

[0044] The server module extension block may have inlet openings aligned with respective flow distribution outlets in the flow distribution system, forming a tight and good integrity seal between the flow distribution system and the performance block.

[0045] According to an embodiment the server module extension block has a cuboid shape.

[0046] The server module extension block may have protrusions, depressions, side openings and the like, but the general shape of the server module extension block is a cuboid shape.

[0047] The inlet side and discharge side are opposite each other. The inlet side and discharge side are on opposite sides of the cuboid shape and are thus positioned opposite each other. The inlet side and the discharge side are facing each other in a first direction, which may be referred to as the flow direction. The height of the server module extension block is measured in the first or flow direction.

[0048] The server module extension block further comprises (front and back) walls 28 which are positioned opposite each other at a distance substantially matching the distance between the front and back panels of the server module. The (front and back) walls 28 are facing each other in a second direction. The width of the server module extension block is measured in the second direction. The server module extension block further comprises side walls 29 which are positioned opposite each other at a distance substantially matching the distance between the side panels of the server module. The side walls 29 are facing each other in a third direction. The length of the server module extension block is measured in the third direction. The third direction may also be referred to as the lateral direction. The first, second and third / lateral direction are perpendicular to each other.

[0049] The width of the server module extension block is smaller than the length of the server module extension block, typically at least 10 times smaller.

[0050] When placed in the hardware immersion cooling system, the inlet side faces the flow distribution system, particularly the flow distribution outlets, while the discharge side is facing the bottom side of a server module, i.e. the inlet side is facing downwards, and the discharge side is facing upwards.

[0051] According to an embodiment, the inlet side of the server module extension block is formed similar or identical to the base of the server module to which it is (to be) connected. This ensures that an assembly of the server module and the server module extension block interacts with the hardware immersion cooling system as a server module without server module extension block would. The inlet side of the server module extension block may for instance comprise legs similar or identical to legs of the server module to interact with supports in the hardware immersion cooling system.

[0052] According to an embodiment the server module extension block comprises flow redistribution means.

[0053] As described above, the server module extension block has a height measured in a first direction associated with the general flow direction, extending between the inlet side and the discharge side. Perpendicular to the first direction, the server module extension block has a width and a length, where the width is typically at least 10 times smaller than the length. The flow redistribution means are configured to redistribute cooling fluid along the length or lateral direction of the server module extension block. The flow redistribution means may also be referred to as flow redistribution elements.

[0054] As a result, the flow of cooling fluid is redistributed over the different discharge openings to better distribute the cooling fluid, and hence the cooling duty, according to the required cooling duty in different parts of the server module. In particular, the flow redistribution means are configured to distribute the cooling fluid not equally over the different discharge openings. Some discharge openings may receive more cooling fluid than other discharge openings. This has the advantage that more cooling fluid can be directed to those parts of the server module that need most cooling duty.

[0055] The flow redistribution means may be positioned in the inner space 25 of the server module extension block.

[0056] The flow redistribution means may also be used to influence the total flow resistance experienced by the cooling fluid flowing from the flow distribution system through the server module extension block and the server module. This total flow resistance influences the flow rate of cooling fluid through a specific assembly of a server module and a server module extension block and thereby indirectly influences the flow rates through other (neighbouring) server modules (with or without server module extension blocks). It is noted that the centralised pump duty, causing the cooling fluid to flow through the tank, is kept constant. The relative flow resistance of the different assemblies causes a flow distribution over the different assemblies, where assemblies with a higher flow resistance than other assemblies receive relatively less cooling fluid (e.g. cooling duty) than assemblies with a lower flow resistance.

[0057] Therefore, the flow redistribution means may also be referred to as flow resistance elements, which may be passive, active, including adjustable active and adjustable passive flow resistance elements.

[0058] According to an embodiment the flow redistribution means comprise at least one flow deflector, including a passive flow deflector and / or an active flow deflector.

[0059] Flow deflectors or flow deflecting elements may be positioned in the inner space to force cooling fluid flowing from the inlet openings to the discharge openings to change direction, for instance such that some discharge openings receive more cooling fluid than others.

[0060] Flow deflectors may be embodied in any suitable manner. The flow deflectors may be passive flow deflectors, such as bended or curved elements, wall segments, tubes that are bended, hooked and / or positioned diagonally or at an angle. According to an embodiment, the passive flow deflectors are adjustable passive flow deflectors, meaning that the orientation or shape of passive flow deflectors may be changed to adaptively change the redistribution of the cooling fluid based on measurements done in the server module extension block, the server module, a neighbouring server module extension block or a neighbouring server module.

[0061] Flow deflectors may also be active flow deflectors, such as pumps or moving elements that actively move cooling fluid in a direction. The active flow deflectors are configured to control the distribution of the cooling fluid over the discharge openings. The active flow deflectors may be adjustable active flow deflectors which can be used adaptively to change the redistribution of the cooling fluid based on measurements done in the server module extension block, the server module, a neighbouring server module extension block or a neighbouring server module, as explained in more detail below. An example of an active flow deflector is a pump.

[0062] According to an embodiment the flow redistribution means comprise one or more internal walls forming two or more separate liquid chambers in the inner space.

[0063] The internal walls may be formed and positioned such that some discharge openings receive more cooling fluid than other discharge openings. At least one liquid chamber may comprise more or less discharge openings than inlet openings, i.e. not the same amount of discharge openings and inlet openings.

[0064] The internal walls max extend between the front and back wall of the server module extension blocks and may extend from the inlet side to the outlet side, thereby creating the liquid chambers.

[0065] According to an embodiment the flow redistribution means comprise a pump.

[0066] The pump, which may be a micro-pump, can be used to increase the flow of cooling fluid towards those parts of the server module comprising high cooling demand components compared to other parts. The activation of the pump could be fixed (always on) or variable according to a local (embedded) temperature sensor and controller as described in more detail below. In the latter case, the pump is considered an adjustable active flow deflector. According to an embodiment the inlet side comprises a first number of inlet openings, and the discharge side comprises a second number of discharge openings, wherein the first number is different from the second number.

[0067] The discharge openings of the server module extension block can align with internal features within the server module to direct the flow of cooling fluid more towards major power (heat) sources, and conversely away from or less to bypass routes and / or low power sources. This alignment may be achieved by carefully choosing the number and positions of the discharge openings.

[0068] In particular, the positioning of the discharge openings may be irregular, i.e. with different distances between neighboring discharge openings along the length.

[0069] This embodiment facilitates an advantageous way to provide flow redistribution means to distributing the cooling fluid optimally for the specific server module.

[0070] According to an embodiment at least a first discharge opening has a first discharge area and at least a second discharge opening has a second discharge area, the first discharge area being greater than the second discharge area and / or at least a first inlet opening has a first inlet area and at least a second inlet opening has a second inlet area, the first inlet area being greater than the second inlet area.

[0071] Differently sized discharge openings provides for an easy way to provide flow redistribution means configured to redistribute the cooling fluid in the lateral direction. The first discharge area may be at least 50% greater than the second discharge area.

[0072] In a further embodiment, one or more discharge openings may be configured to have a variable discharge area which can be controlled, e.g. by a (micro-)controller which may be positioned in the server module extension block. The control may be done based on measurements obtained by sensors, positioned in the server module extension block, the server module or a neighbouring server module extension block or neighbouring server module. The discharge opening may for instance comprise a diaphragm similar to a photocamera, which can be controlled to change the discharge area. Differently sized inlet openings provides for an easy way to redistribute the cooling fluid in the lateral direction. The first inlet area may be at least 50% greater than the second inlet area.

[0073] In a further embodiment, one or more inlet openings may be configured to have a variable inlet area which can be controlled, e.g. by a (micro-)controller which may be positioned in the server module extension block. The control may be done based on measurements obtained by sensors, positioned in the server module extension block, the server module or a neighbouring server module extension block or neighbouring server module. The inlet opening may for instance comprise a diaphragm which can be controlled to change the inlet area.

[0074] Inlet openings with a variable inlet area and discharge openings with a variable discharge area are also considered flow redistribution means.

[0075] According to an embodiment the server module extension block comprises a sensor, the sensor being selected from

[0076] • flow sensor,

[0077] • cooling fluid quality sensors,

[0078] • thermometer.

[0079] Further provided may be a controller, such as a micro controller, which is configured to receive measurement data from the sensor. The controller may be positioned in the inner space of the server module extension block, but the controller may also be positioned at another suitable location, i.e. at the outside of the server module extension block or remote from the server module extension block. The controller may be configured to be linked to a plurality of sensors, comprised by the same and / or different server module extension blocks, thereby creating an embedded system.

[0080] More than one sensor may be provided. The sensor(s) may either be placed in the server module extension block and / or in the server module and / or in a neighbouring server module extension block and / or in a neighbouring server module, to create an embedded system in the performance block.

[0081] The sensors can provide measurements, e.g. local temperature measurements or local flow speeds, wherein the controller is configured to control the flow redistribution means where possible, to trigger a change to the flow resistance of the performance block internal flow channels, change the inlet areas of one or more inlet openings, change the discharge area of one or more discharge openings, divert the flow in the lateral direction by changing the orientation of one or more flow deflectors, control the operating parameters of one or more active flow deflectors, e.g. control the pump, to guide more or less cooling fluid towards parts of the server module that require a high / lower cooling demand.

[0082] In general, a server module extension block is an easy way to add sensors to the hardware immersion cooling system. There is always a need for more measurement data to gain deeper understanding of the functioning of the immersion cooling system 1.

[0083] All the above-mentioned optional modulations work by the principle of varying flow resistance, where the centralized pump circulating the cooling fluid, can be operated at a constant duty.

[0084] According to a further aspect there is provided an assembly of a server module and a server module extension block according to the above.

[0085] The assembly is formed by mechanically connecting a server module and a server module extension block by means of corresponding connection parts positioned on the server module and the server module extension block. Alternatively, the server module and the server module extension block may be integrally formed. The term integrally formed is used to indicate that the server module and the server module extension block are formed as one piece or two pieces connected in a non-releasable manner, i.e. not releasable without causing damage.

[0086] It is noted that all embodiments of the server module extension block described in this text can be part of such an assembly.

[0087] According to a further aspect there is provided a server module comprising one or more connection parts, the connection parts being configured to (mechanically) connect to corresponding connection parts of a server module extension block.

[0088] According to a further aspect, there is provided a hardware immersion cooling system comprising an assembly according to the above. The hardware immersion cooling system may comprise a plurality of assemblies, wherein the top sides of the respective assemblies are at the same level. The hardware immersion cooling system may be as described above and may comprise one or more vertical receiving slots which comprise such an assembly. The top sides of the server module(s) is / are preferably positioned at the same height, in particular close to the cooling fluid surface. Preferably, the lifting connectors of the server module are (at least partially) above the cooling fluid surface or the level of the weir.

[0089] Hardware immersion cooling system may comprise an assembly having a combined height of the server module and the server module extension block that matches the height of the receiving slot.

[0090] According to an embodiment the hardware immersion cooling system comprises a plurality of assemblies, wherein respective assemblies comprise respective server module extension blocks with different heights and wherein the top sides of the respective server modules are at the same level.

[0091] The term level is used to refer to a certain height in the gravitational direction. The level is preferably close to the cooling fluid surface of the level of the weir.

[0092] The hardware immersion cooling system may comprise a plurality of assemblies wherein the height of the server module extensions blocks is different for different assemblies, but the height of the assembly is the same for different assemblies.

[0093] The hardware immersion cooling system may comprise at least one assembly and a server module without server module extension block, wherein the level of the top side of the server module of the assembly is the same as the level of the tops side of the server module without server module extension block.

[0094] The hardware immersion cooling system may comprise a plurality of assemblies, wherein the server module heights vary over the plurality of assemblies and the respective assembly heights are equal.

[0095] A skilled person will understand that terms like ‘the same’ or ‘close to’ allow for small deviations in the order of a couple of centimetres. According to an embodiment the hardware immersion cooling system comprises a flow distribution system, and a direct fluid connection is established between the server module extension block and the flow distribution system.

[0096] Such a direct fluid connection prevents by-pass of cooling fluid, i.e. cooling fluid which flows outside of the server modules. The direct fluid connection preferably is a leakproof fluid connection. The direct fluid connection may be established in any suitable manner, examples of which are provided in this text. The direct fluid connection may be a mechanical connection.

[0097] According to a further aspect there is provided a method of loading a hardware immersion cooling system with server modules, the method comprising: selecting a server module to be loaded, selecting a server module extension block, connecting the server module and the server module extension block to form an assembly and loading the assembly in the hardware immersion cooling system.

[0098] In particular, the discharge side of the server module extension block is connected to the base of the server module.

[0099] The assembly is loaded in the hardware immersion cooling system with an orientation wherein the server module extension block is below the server module.

[0100] According to an embodiment there is provided a method wherein selecting a server module extension block comprises selecting a height of the server module extension block and / or selecting flow redistribution means and / or selecting a configuration of the inlet side of the server module extension block to form a direct fluid connection between the flow distribution system and the server module extension block.

[0101] The method may comprise selecting and providing a server module extension block that is optimally managing the flow interface between the flow distribution system and the server module.

[0102] According to an embodiment there is provided a method wherein selecting a height of the server module extension block comprises determining a preferred level for the top side of server module when loaded, determining for the server module an actual or expected level of the top side of the server module when loaded, determining a height of the server module extension block based on the determined preferred level and actual or expected level, providing a server module extension block with the determined height, connecting the server module and the server module extension block to form an assembly and loading the assembly in the hardware immersion cooling system.

[0103] The preferred level may be a level specified by the hardware immersion cooling system manufacturer. The preferred level may be such that the server modules when placed in the receiving slots have their top side close to or just above (e.g. 1 or 2 cm’s) the liquid fill level of the tank. The preferred level may be such that the server modules when placed in the receiving slots have their top side at the same level as the weir of the hardware immersion cooling system. The preferred level may be such that the lifting connectors are just above (e.g. 1 or 2 cm’s) the liquid fill level of the tank 2 or just above the level of the weir (e.g. 1 or 2 cm’s).

[0104] Determining a height of the server module extension block based on the determined preferred level and actual level may also result in deciding that no server module extension block is required. For instance, if the preferred level and actual level are equal or have a difference lower than a predetermined threshold. These server modules may be loaded in the hardware immersion cooling system without a server module extension block.

[0105] According to an embodiment there is provided a method wherein selecting flow redistribution means comprises determining required cooling duties of different parts of the server module, selecting flow redistribution means based on the determined required cooling duties, providing a server module extension block with the selected flow redistribution means, connecting the server module and the server module extension block to form an assembly and loading the assembly in the hardware immersion cooling system. According to an embodiment there is provided a method wherein selecting flow redistribution means comprises selecting a preferred configuration of the inlet side of the server module extension block to form a direct fluid connection between the flow distribution system and the server module extension block, providing a server module extension block with the selected configuration, connecting the server module and the server module extension block to form an assembly and loading the assembly in the hardware immersion cooling system, thereby forming a direct fluid connection between the flow distribution system and the server module extension block.

[0106] BRIEF DESCRIPTION OF THE DRAWINGS

[0107] In the figures, the subject-matter of the invention is schematically shown, wherein identical or similarly acting elements are usually provided with the same reference signs.

[0108] Figure 1 schematically shows an example of a hardware immersion cooling system,

[0109] Figure 2a schematically shows a server module according to the prior art,

[0110] Figure 2b schematically shows an open view of the internals of a server module according to the prior art,

[0111] Figure 3a schematically shows a hardware immersion cooling system with a plurality of server modules according to the prior art,

[0112] Figure 3b schematically shows a hardware immersion cooling system with a plurality of server modules according to an embodiment,

[0113] Fig.’s 4a-h schematically show different embodiments of server module extension blocks,

[0114] Figure 5 schematically shows an assembly according to an embodiment,

[0115] Figure 6a schematically shows a server module in a hardware immersion cooling system according to the prior art,

[0116] Fig.’s 6b-c schematically show a server module in a hardware immersion cooling system according to different embodiments.

[0117] DESCRIPTION OF EMBODIMENTS

[0118] With reference to the figures embodiments will be described relating to a server module extension block 20 that can be positioned between a server module 1 and a flow distribution system of a hardware immersion cooling system 1. The server module extension block 20 brings several advantages, including that it may be provided with an internal structure to redistribute the flow to provide more cooling capacity to the hottest parts of the server modules, the top of the different server modules in the tank can be equalized in height, facilitating cable management / servicing etc. and by-passes of cooling fluid can be reduced.

[0119] Fig. 1 shows an example of a hardware immersion cooling system explained in more detail above. The hardware immersion cooling system 1 is configured to be loaded with server modules 10. An example of a server module 10 is explained in more detail above, with reference to Fig.’s 2a and 2b.

[0120] Fig. 3a schematically shows a tank 2 of a hardware immersion cooling system 1 in which a plurality of server modules 10 are placed. The server modules 10 have different server module heights, so the top sides 14 of the server modules 10 are not aligned. In practice, some of the top sides 14 will be below the liquid fill level of the tank 2, which is not shown in Fig. 3a.

[0121] There is provided a server module extension block 20 for use in a hardware immersion cooling system 1 , of which an embodiment is shown Fig.’s 4a - b. The server module extension block 20 comprises an inner space 25 configured to contain and transmit cooling fluid. The server module extension block 20 further comprises an inlet side 21 , best shown in Fig. 4b, comprising one or more inlet openings 22 configured to receive cooling fluid into the inner space 25, and a discharge side 23, best shown in Fig. 4c, comprising one or more discharge openings 24 configured to discharge cooling fluid from the inner space 25. The discharge side 23 is configured to be connected to a server module 10.

[0122] The server module extension block 20 has a cuboid shape that matches the shape of a server module 10. The server module extension block 20 has a height heb, a width web and a length leb.

[0123] Fig.’s 4a and 4b show an embodiment in which the inlet side 21 comprises five inlet openings 22 and the discharge side comprises three discharge openings 24. By having a different number of inlet openings and discharge openings positioned along the length of the server module extension block, the cooling fluid that is passed through the server module extension block towards the server module 10 can be redistributed over the length of the server module extension block 20. The positioning of the discharge openings 24 along the length of the server module extension block 20 may be chosen to match the internal structure of the server module and the positioning of the heat generating electrical components in the server module 10 to ensure optimal flow of the cooling fluid through the server module 10 and provide optimal cooling where required.

[0124] Also, the size of the inlet openings 22 and / or discharge openings 24 may vary, thereby forming flow redistribution means. Fig. 4c shows an embodiment of a server module extension block 20 comprising two first discharge openings 24 having a small discharge area and one second discharge opening 24 having a large discharge area. The terms small and large are used with respect to each other. This embodiment will guide more cooling fluid towards the centre of the server module than towards the sides, as the larger discharge area is positioned in the middle.

[0125] Fig. 4d shows an embodiment of a server module extension block 20 comprising four inlet openings 22 having a small inlet area and one second inlet opening 22 having a larger inlet area. Again, the terms small and large are used with respect to each other. This embodiment will guide more cooling fluid towards the centre of the server module than towards the sides, as the larger inlet area is positioned in the middle.

[0126] It will be understood that Fig.’s 4c and 4d may be different embodiments but may also be combined.

[0127] The inner space 25 may comprise flow redistribution means 27, 30. An example of flow redistribution means are flow deflectors 30, of which an example is shown in Fig. 4e. The flow deflectors 30 as shown in Fig. 4e are embodied as passive flow deflectors formed by wall segments which are orientated at an angle to redistribute the flow towards the centre of the server module extension block (seen in the length direction). These flow deflectors will cause more cooling fluid to flow towards the middle discharge opening 24 than to the discharge openings 24 at the sides.

[0128] These particular flow deflectors may also be embodied as moveable flow deflectors by suspending the flow deflectors 30 in a rotatable manner such that the angle of orientation can be actively controlled depending on the cooling duty required in different parts of the server module. According to an alternative embodiment, schematically depicted in Fig. 4f, the flow redistribution means comprise one or more internal walls 27 forming two or more separate liquid chambers 26 in the inner space 25. This embodiment ensures that all cooling fluid received by certain inlet openings 22 flows towards certain discharge openings 24 positioned in the same liquid chamber 26 and thus ensures for a reliable manner of redistributing cooling fluid.

[0129] According to an embodiment as schematically depicted in Fig. 4g, the server module extension block 20 comprises a sensor 31. The sensor 31 may be a flow sensor to measure the flow speed of the cooling fluid, a cooling fluid quality sensor to measure certain properties of the cooling fluid to determine the quality of the cooling fluid (e.g. to detect pollution), a thermometer to measure the temperature of the cooling fluid or any other suitable sensor.

[0130] The sensor readings may be used to optimize the operation of the hardware immersion cooling system 1. In particular, the sensor readings may be used to control the flow redistribution means where possible, such as to control the shape or orientation of passive flow deflectors, control a pump, control the variable inlet and / or discharge areas of the inlet and discharge openings respectively. In order to do so, a controller 32 may be provided, configured to receive sensor readings and transmit control signals to control the flow redistribution means based on the received sensor readings.

[0131] According to an embodiment as schematically depicted in Fig. 4h, the server module extension block 20 comprises a pump, configured to pump cooling duty in a certain direction along the length of the server module extension module 20. In the example shown in Fig. 4h, more cooling fluid is forced towards the discharge opening 24 positioned in the middle. This may be advantageous in a situation wherein more cooling duty is required in the middle of the server module 10.

[0132] It is noted that in the examples shown in the Figures the flow redistribution means are all shown as redistributing more cooling duty towards the middle of the server module extension block 10. This is however only shown by way of example and alternative embodiments are easily conceivable, for instance in which more cooling fluid is forced towards one or both sides.

[0133] Fig. 5 schematically shows an assembly of a server module 10 and a server module extension block 20. Not shown are the connection parts used to mechanically connect the server module 10 and the server module extension block 20. Fig. 3b schematically shows a hardware immersion cooling system 1 with server modules 10 having different heights, but the top sides 14 of the server modules 10 being aligned, i.e. at the same level. Fig. 3b shows a server module 10 without server module extension block 20 on the left. Fig. 3b further shows two assemblies of a server module 10 and a server module extension block 20, where the server modules 10 of the assemblies have a lower height than the server module 10 without server module extension block 20. The top sides 14 of all server modules 10 being at the same level, thanks to the server module extension blocks 20 attached to the server modules 10 of the assemblies.

[0134] Fig. 6a schematically depicts a cross sectional view of a server module 10 positioned in a hardware immersion cooling system 1 according to the prior art. Between the base 15 of the server module 10 and the flow distribution outlets is a gap through which cooling fluid discharged by the flow distribution system through the flow distribution outlet 6 can by-pass the server module 10. A by-pass flows are shown with arrows in Fig. 6a, but it will be understood that by-pass flows may also occur in a direction perpendicular to the plane of the drawing.

[0135] Fig. 6b schematically depicts a cross sectional view of an assembly of a server module 10 and a server module extension block 20, e.g. according to any one of the embodiments described, positioned in a hardware immersion cooling system 1 according to an embodiment. The server module extension block 20 is configured to form a fluid connection between the flow distribution system 4 and the inner space of the server module extension block 20.

[0136] The inlet side 21 of the server module extension block 20 as shown in Fig. 6b has extending or protruding inlet conduits 41. When an assembly is positioned in a receiving slot 3 of the hardware immersion cooling system 1 the inlet conduits 41 engage with a flow distribution outlet 6 to form a fluid connection between the flow distribution system 4 and the inner space of the server module extension block 20.

[0137] Alternative configurations are possible as well. For instance, the flow distribution system 4 may comprise flow distribution outlets conduits, extending upwardly from the flow bar 5, which are configured to engage with respective inlet openings 21 of the server module extension block 20 when positioned in a receiving slot 3 to form a fluid connection. Fig. 6c shows a further embodiment in which the flow distribution system 4 comprises flow distribution outlets 6 with associated lids 7 which are configured to close the respective flow distribution outlets 6. The lids can move between a closed position, in which the flow distribution outlet 6 is closed and an opened position, in which the flow distribution outlet 6 is opened. The lids 7 can be pushed open from the outside (seen from the flow distribution system 4) by the inlet side 21 of the server module extension block 20. The inlet side 21 of the server module extension block 20 may be configured to open one or more lids 7 when being positioned in the receiving slot 3 of the hardware immersion cooling system 1. In the embodiment depicted in Fig. 6c this is done by the inlet conduits 41 which extend from the inlet side 21 of the server module extension block 20.

[0138] According to the embodiment depicted in Fig. 6c, the lids 7 are held in the closed position by coil springs 8. The inlet conduits 41 are configured to enter the flow distribution outlet 6 and push lid 7 to the opened position when an assembly is positioned. When the assembly is removed, the coil springs 8 will move the lid 7 back to the closed position. The inlet conduits 41 comprise conduit side openings 43 provided in the wall forming the inlet conduits 41.

[0139] This embodiment has the advantage that the design of the server module extension blocks can be used to determine which flow distribution outlets 6 are used and which are not used to be able to better manage the flow and distribution of cooling fluid towards the server module 10.

[0140] Fig. 6c shows a server module extension block 20 comprising internal conduits 42 forming a direct, one on one, fluid connection between a single flow distribution outlet 6 / inlet opening 22 and a discharge opening 23 of the server module extension block. This embodiment allows for an improved management of the flow and flow distribution of cooling fluid towards the server module 10.

[0141] Additional embodiments

[0142] Further provided is an embodiment of a server module extension block 20 for use in a hardware immersion cooling system 1 , wherein the server module extension block 20 comprises

[0143] - an inner space 25 configured to contain and transmit cooling fluid,

[0144] - an inlet side 21 comprising one or more inlet openings 22 configured to receive cooling fluid into the inner space 25, - a discharge side 23 comprising one or more discharge openings 24 configured to discharge cooling fluid from the inner space 25, wherein the inlet side 21 is connected to or is configured to be connected to a server module 10.

[0145] Such a server module extension block can be positioned on top of a server module, i.e. on the top side 14 of the server module 10. The server module extension block may be configured to be mechanically connected to the server module 10 to form an assembly. The server module extension block 20 may be configured to form a direct fluid connection between the server module 10 and the server module extension block 20. The discharge side 23 of the server module extension block 20 may be provided with lifting connectors 11 to facilitate inserting and removing the assembly in and from the hardware immersion cooling system 1 .

[0146] The server module extension block 20 may comprise a sensor 31 , the sensor being selected from

[0147] • flow sensor,

[0148] • cooling fluid quality sensors,

[0149] • thermometer.

[0150] Further provided is an assembly of such a server module extension block 20 and a server module as well as a hardware immersion cooling system comprising such an assembly.

[0151] Further provided is a method of loading a hardware immersion cooling system 1 with server modules 10, the method comprising: selecting a server module 10 to be loaded, selecting a server module extension block 20, and connecting the server module 10 and the server module extension block 20 to form an assembly and loading the assembly in the hardware immersion cooling system 1.

[0152] The assembly is loaded in the hardware immersion cooling system 1 with an orientation wherein the server module extension block 20 is above the server module 10.

[0153] According to an embodiment selecting a server module extension block comprises selecting a height of the server module extension block. Selecting a height of the server module extension block may comprise determining a preferred level for the top side of server module when loaded, determining for the server module an actual level of the top side of the server module when loaded, determining a height of the server module extension block based on the determined preferred level and actual level, providing a server module extension block with the determined height, connecting the top side of the server module to the inlet side of the server module extension block to form an assembly and loading the assembly in the hardware immersion cooling system.

[0154] In particular, the discharge side of the server module extension block is connected to the base of the server module.

[0155] This embodiment provides the advantage that the height of the server module extension block may be selected such that the top of the assembly is located at a preferred height or level.

[0156] The invention is not limited to the embodiments shown in the drawings and described hereinbefore, which may be varied in different manners within the scope of the claims and their technical equivalents.

[0157] REFERENCE LIST

[0158] 1. Hardware immersion cooling system

[0159] 2. Tank

[0160] 3. Receiving slots

[0161] 4. Flow distribution system

[0162] 5. Flow bar

[0163] 6. Flow distribution outlet

[0164] 7. Lid

[0165] 8. Coil spring

[0166] 9. Tank lid

[0167] 10. Server module

[0168] 11. Lifting connector

[0169] 12. Components

[0170] 14. Top side of the server module

[0171] 15. Bottom side or base of the server module

[0172] 16. (Front / back) Panel

[0173] 17. Leg

[0174] 18. Side panels

[0175] 20. Server module extension block

[0176] 21. Inlet side

[0177] 22. Inlet openings

[0178] 23. Discharge side

[0179] 24. Discharge openings

[0180] 25. Inner space

[0181] 26. Liquid chambers

[0182] 27. Internal walls

[0183] 28. (Front / back) wall

[0184] 29. Side walls

[0185] 30. Flow deflectors

[0186] 31. Sensors

[0187] 32. Controller

[0188] 33. (micro-) pump

[0189] 41. Inlet conduits heb height of server module extension block web width of server module extension block leb length of server module extension block

Claims

CLAIMS1. Server module extension block (20) for use in a hardware immersion cooling system (1), wherein the server module extension block (20) comprises- an inner space (25) configured to contain and transmit cooling fluid,- an inlet side (21) comprising one or more inlet openings (22) configured to receive cooling fluid into the inner space (25),- a discharge side (23) comprising one or more discharge openings (24) configured to discharge cooling fluid from the inner space (25), wherein the discharge side (23) is connected to or is configured to be connected to a server module (10).

2. Server module extension block (20) according to claim 1 , wherein the server module extension block is configured to be mechanically connected to a server module (10).

3. Server module extension block (20) according to any one of the preceding claims, wherein the server module extension block (20) is configured to form a direct fluid connection between a flow distribution system (4) and the server module extension block (20).

4. Server module extension block (20) according to any one of the preceding claims, wherein the server module extension block comprises flow redistribution means (27, 30, 33).

5. Server module extension block (20) according to claim 4, wherein the flow redistribution means comprise at least one flow deflector (30), including a passive flow deflector and / or an active flow deflector.

6. Server module extension block (20) according to any one of the claims 4 - 5, wherein the flow redistribution means comprise one or more internal walls (27) forming two or more separate liquid chambers in the inner space (25).

7. Server module extension block (20) according to any one of the claims 4 - 6, wherein the flow redistribution means comprise a pump (33).

8. Server module extension block (20) according to any one of the preceding claims, wherein the inlet side (21) comprises a first number of inlet openings (22), and the discharge side (23) comprises a second number of discharge openings (24), wherein the first number is different from the second number.

9. Server module extension block (20) according to any one of the preceding claims, wherein- at least a first discharge opening (24) has a first discharge area and at least a second discharge opening (24) has a second discharge area, the first discharge area being greater than the second discharge area and / or- at least a first inlet opening (22) has a first inlet area and at least a second inlet opening (22) has a second inlet area, the first inlet area being greater than the second inlet area.

10. Server module extension block (20) according to any one of the preceding claims, the server module extension block (20) comprises a sensor (31), the sensor (31) being selected from• flow sensor,• cooling fluid quality sensors,• thermometer.

11. Assembly of a server module (10) according to claim 12 and a server module (20) extension block according to any one of the claims 1 - 10.

12. Server module (10) comprising one or more connection parts, the connection parts being configured to connect to corresponding connection parts of a server module extension block (20).

13. Hardware immersion cooling system (1) comprising an assembly according to claim 11.

14. Hardware immersion cooling system (1) according to claim 13, wherein the hardware immersion cooling system (1) comprises a plurality of assemblies, wherein the top sides of the respective assemblies are at the same level.

15. Hardware immersion cooling system (1) according to any one of the claims 13 - 14, wherein the hardware immersion cooling system (1) comprises a flow distributionsystem (4), and wherein a direct fluid connection is established between the server module extension block (20) and the flow distribution system (4).

16. Method of loading a hardware immersion cooling system (1) with server modules (10), the method comprising: selecting a server module (10) to be loaded, selecting a server module extension block (20), and connecting the server module (10) and the server module extension block (20) to form an assembly and loading the assembly in the hardware immersion cooling system (1).

17. Method of loading a hardware immersion cooling system (1) with server modules (10) according to claim 16, wherein selecting a server module extension block (20) comprises selecting a height of the server module extension block (20) and / or selecting flow redistribution means and / or selecting a configuration of the inlet side (21) of the server module extension block (20) to form a direct fluid connection between the flow distribution system (4) and the server module extension block (20).

18. Method of loading a hardware immersion cooling system (1) with server modules (10) according to any one of the claims 16 - 17, wherein selecting a height of the server module extension block (20) comprises determining a preferred level for the top side (14) of the server module (10) when loaded, determining for the server module (10) an actual or expected level of the top side (14) of the server module when loaded, determining a height of the server module extension block (20) based on the determined preferred level and actual or expected level, providing a server module extension block (20) with the determined height, connecting the server module (10) and the server module extension block (20) to form an assembly and loading the assembly in the hardware immersion cooling system (1).

19. Method of loading a hardware immersion cooling system (1) with server modules (10) according to any one of the claims 16 - 18, wherein selecting flow redistribution means comprises determining required cooling duties of different parts of the server module (20),selecting flow redistribution means based on the determined required cooling duties, providing a server module extension block (20) with the selected flow redistribution means, connecting the server module (10) and the server module extension block (20) to form an assembly and loading the assembly in the hardware immersion cooling system (1).

20. Method of loading a hardware immersion cooling system (1) with server modules (10) according to any one of the claims 16 - 19, wherein selecting flow redistribution means comprises selecting a preferred configuration of the inlet side (21) of the server module extension block (20) to form a direct fluid connection between the flow distribution system (4) and the server module extension block (20), providing a server module extension block (20) with the selected configuration, connecting the server module (10) and the server module extension block (20) to form an assembly and loading the assembly in the hardware immersion cooling system (1), thereby forming a direct fluid connection between the flow distribution system (4) and the server module extension block (20).

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