Improving the cooling of an immersion tank

Abstract

An installation comprises: - an immersion tank (3) containing computer devices (2) immersed in a dielectric fluid (4); - a cooling circuit comprising a pump (10) and an injection beam (40) fluidically connecting the pump (10) to the immersion tank. The injection beam (40) extends along a wall (7) of the immersion tank (3), being mounted within the immersion tank (3) between a bottom (5) of the immersion tank and the computer devices (2). Figure for the abbreviation: Fig. 3

Description

Title of the invention: Improvement of the cooling of an immersion tank technical field

[0001] The present invention relates to the general technical field of immersion cooling of computer devices such as computer servers. STATE OF THE ART

[0002] Immersion cooling is an innovative cooling technology for computer devices that offers significant advantages over traditional air cooling methods. Immersion cooling involves immersing computer devices, typically computer servers, in immersion tanks that form a bath of heat-transferring dielectric fluid.

[0003] This passive cooling process is very efficient. Compared to air or water cooling, immersion cooling can drastically reduce cooling energy consumption.

[0004] The dielectric fluid is chosen to maximize the immersion cooling capacity. The dielectric fluid may, for example, be a synthetic hydrocarbon-based fluid. However, to protect the computer devices, it is important to cool them sufficiently to prevent the internal temperature of their components (particularly the processing chips) from exceeding 50°C, which could damage them. The high density of computer devices in the immersion tank is designed to minimize the footprint and overall size of the installation, making the circulation of the dielectric fluid within the tank critical. Furthermore, the weight of the dielectric oil in an installation is very high (several hundred kilograms for an immersion tank with approximately twenty units).It is therefore difficult to enlarge the installation to increase the circulation space of the dielectric fluid in the immersion tank.

[0005] Finally, the installations include several computer devices, each weighing approximately thirty kilograms and supported at the base of the installations. The structural stability of the installations is therefore a challenge. Description of the invention

[0006] One object of the present application is to remedy the aforementioned drawbacks. More specifically, one object of the present invention is to provide an installation for the immersion cooling of computer devices, such as servers computer systems, having a more efficient computer device cooling system without affecting the installation's footprint or structural integrity.

[0007] To this end, according to a first aspect, an installation comprising: - an immersion tank configured to receive a dielectric fluid and comprising retention means configured to receive computer devices such that the computer devices are immersed in the dielectric fluid; - a cooling circuit comprising: - a pump configured to draw dielectric fluid into the installation; and - an injection beam fluidly connecting the pump to the immersion tank, the injection beam comprising a series of orifices distributed along its length so as to inject dielectric fluid discharged by the pump into the immersion tank. In addition, the injection beam extends over all or part of a length of a wall of the immersion tank by being mounted in the immersion tank between a bottom of the immersion tank and the computer devices.

[0008] Some preferred but not limiting features of the installation according to the first aspect are the following, taken individually or in combination: - an upper face of the injection beam is configured to come into contact with the computer devices so as to form a support for the computer devices; - a cross-section of the injection beam is parallelepiped; - the installation further includes at least one computer device immersed in the dielectric fluid and mounted in the restraint means, the computer device bearing on the upper face of the injection beam; - the injection beam includes at least as many orifices as the immersion tank is configured to receive computing devices, each orifice opening near a corresponding computing device; - the installation includes an additional injection beam placed on an additional wall of the immersion tank extending opposite the wall, the additional injection beam fluidly connecting the pump to the immersion tank and comprising a series of additional orifices distributed along its length so as to inject dielectric fluid into the immersion tank; the additional injection beam extending over all or part of a length of the additional wall of the immersion tank by being mounted in the immersion tank between the bottom of the immersion tank and the computer devices; - The installation also includes: a filter tank comprising a first compartment and a second compartment separated by a central partition, an opening being formed in the central partition so as to connect them fluidic the first compartment and the second compartment (23); means for bringing the dielectric fluid from the immersion tank to the first compartment of the filter tank; a filter mounted in the opening of the central wall to filter the dielectric fluid flowing to the second compartment; and the pump is configured to draw dielectric fluid into the second compartment; - the filter tank is separated from the immersion tank by a partition wall, and the supply means include a window formed in the partition wall so as to establish fluidic communication between the immersion tank and the filter tank, a level of dielectric fluid in the immersion tank being higher than a level of dielectric fluid in the filter tank such that the dielectric fluid flows through the window into the filter tank when its level reaches a lower edge of the window; and / or - the supply means include an additional pump configured to draw dielectric fluid into the immersion tank and discharge it into the first compartment of the filter tank.

[0009] According to a second aspect, a data center is proposed comprising an installation according to the first aspect and computer devices mounted in the restraint means. DESCRIPTION OF THE FIGURES

[0010] Other features, objectives and advantages of the invention will become apparent from the following description, which is purely illustrative and not limiting, and which should be read in conjunction with the accompanying drawings on which:

[0011] Fig. 1 illustrates schematically and in perspective an example of an installation conforming to an embodiment;

[0012] Fig. 2 is a top view of an example of an installation conforming to an embodiment;

[0013] The [Fig.3] is a partial cross-sectional view of the installation example of the [Fig.2], in a plane cutting the injection beams;

[0014] Figure 4 is a partial cross-sectional view of the installation example of Figure 2, in a plane including the front wall of the immersion tank; and

[0015] Fig. 5 is a cross-sectional view of the example installation of Fig. 2, in a plane passing through the computer devices.

[0016] Throughout the figures, similar elements bear identical references. DETAILED DESCRIPTION OF THE INVENTION

[0017] An installation 1 for the immersion cooling of computer devices 2, such as computer servers, comprises an immersion tank 3 filled of a dielectric fluid 4 and non-corrosive in which the computer devices 2 are immersed, and a dielectric fluid cooling system 4.

[0018] The immersion tank 3 comprises a bottom wall 5 configured to be placed on a generally horizontal support (for example, the ground), side walls 6, 7 extending from the bottom wall 5, and an opening extending opposite the bottom wall 5. The side walls 6, 7 give the immersion tank 3 a generally rectangular cross-section. The side walls 6, 7 thus comprise a front wall and a rear wall forming the long sides of the immersion tank 3 and two transverse walls 6 connected at their edges to the front and rear walls 7. The installation 1 further comprises a cover configured to cover the opening and close the immersion tank 3.

[0019] In what follows, the invention will be described with reference to the operating configuration of the installation 1. In particular, "upper" (respectively "top") and "lower" (respectively "bottom") are used with reference to the installation 1, a lower part being disposed on the side of the bottom of the immersion tank 3 while an upper part will be disposed on the side of the opening.

[0020] The immersion tank 3 includes retention means 8 for the computer devices 2, for example, racks, mounted on the front and rear walls 7 and configured to hold each computer device 2 in position within the immersion tank 3. Each computer device 2 has an upper edge 9, configured to face the lid and having connectors configured to be connected to a network via electrical cables. Each electrical cable includes for this purpose a lug 28, configured to be connected to the corresponding connector on the upper edge 9 of the computer device 2, and a portion of cable 29 configured to electrically connect the lug 28 to the computer network. The retention means 8 are further positioned so that, during use, the upper edge 9 of the computer devices 2 is immersed in the dielectric fluid 4.

[0021] The dielectric fluid 4 may comprise a synthetic hydrocarbon-based fluid, for example, isoparaphine. Such a dielectric fluid 4 is non-corrosive and has a thermal conductivity of approximately 0.137 W / km at 25°C, which is almost six times that of air. The dielectric fluid 4 serves to absorb the heat generated by the immersed computer devices 2. It is continuously cooled by a cooling system comprising a pump 10 configured to draw in the dielectric fluid 4 and discharge it into a heat exchanger 11, where it is cooled before being discharged into the immersion tank 3.

[0022] In one embodiment, the cooling system comprises two cooling circuits, each comprising a pump 10 and a heat exchanger 11, so as to guarantee the cooling of the dielectric fluid 4, even in the event of a failure of one of the components. In this embodiment, only one of the cooling circuits is operated at a time, the other cooling circuit being redundant.

[0023] In order to improve the cooling of the computer devices 2, the installation 1 further includes an injection beam 40 fluidically connecting the pump 10 to the immersion tank 3. The injection beam 40 includes a series of orifices 41 distributed along its length so as to inject dielectric fluid 4 discharged by the pump 10 into the immersion tank 3. In addition, the injection beam 40 extends over all or part of a length of the front (and / or rear) wall 7 of the immersion tank 3 by being mounted in the immersion tank 3 between the bottom 5 of the immersion tank 3 and the computer devices 2.

[0024] Preferably, the installation 1 comprises two substantially identical injection beams 40 which are fixed to the front and rear walls 7 of the immersion tank 3, between the bottom 5 and the computer devices 2. The injection beams 40 are substantially horizontal.

[0025] The injection beams 40 therefore play both a role in the hydraulic distribution of the dielectric fluid 4 and in providing mechanical support. Indeed, the injection beams 40 form a reinforcement at the bottom of the immersion tank 3, improving the mechanical strength and structural stability of the immersion tank 3.

[0026] Furthermore, since the injection beams 40 are located under the computer devices 2, the computer devices 2 do not form a barrier to the circulation of the dielectric fluid 4 in the lower part of the immersion tank 3: the dielectric fluid 4 is therefore distributed more homogeneously in the lower part, then rises along the computer devices 2 to cool them. The homogeneous distribution of the fluid under the computer devices 2 thus creates a preferential horizontal circulation channel for the dielectric fluid 4 in the lower part and reduces the circulation of the dielectric fluid 4 in the areas located between the computer devices 2 and the walls 6, 7 of the immersion tank 3, where the dielectric fluid 4 stagnates and loses its cooling capacity.

[0027] The cooling of computer devices 2 is therefore improved.

[0028] In addition, the presence of the injection beams 40 under the computer devices avoids the risk that the computer devices 2 will fall to the bottom of the immersion tank 3.

[0029] In one embodiment, the injection beams 40 extend over the majority of the length of the front and rear walls 7, preferably over their entire length in order to improve the mechanical strength of the immersion tank 3 and to cool all the computer devices 2.

[0030] The orifices 41 are regularly distributed along each injection beam 40 in order to cool the dielectric fluid 4 homogeneously. Preferably, each injection beam 40 includes at least one orifice 41 per computer device 2 to be cooled, extending close to the corresponding computer device 2 (the number of computer devices 2 that can be housed in the immersion tank 3 being determined by the retaining means 8). In the case where the injection beam 40 includes only one orifice 41 per computer device 2, the orifice 41 may be centered with respect to the lateral edge of the computer device 2; alternatively, the orifices 41 may extend along the space separating pairs of computer devices 2 (or, in the case of computer devices 2 adjacent to the transverse walls of the immersion tank 3, between the computer device 2 and the opposite transverse wall 6).In another example, each injection beam 40 includes two orifices 41 per computer device 2: the two orifices 41 can then be arranged in the extension of the computer device 2, under its lower edge; alternatively, one orifice 41 can be centered with respect to the lateral edge of the computer device 2, the other being placed opposite the space separating the computer devices 2 two by two or the transverse wall 6. .

[0031] In the case where each injection beam 40 includes two orifices 41 per computer device 2, each orifice 41 can have a circular section whose diameter is adapted to the desired injection flow rate.

[0032] In one embodiment, the injection beams 40 are positioned relative to the retaining means 8 so that the lower edge of the computer devices 2 rests (directly or indirectly, for example via feet) on the injection beams 40 when the computer devices 2 are mounted in the retaining means 8. The injection beams 40 thus form a support for the computer devices 2: they therefore reinforce the mechanical stability of the installation 1 by taking up part of the weight of the computer devices 2 in the lower area of ​​the immersion tank 3. Indeed, the retaining means 8 can serve primarily as guides for the installation 1 of the computer devices 2 (particularly in the case of the use of racks), the weight then being largely taken up by the injection beams 40.

[0033] Each injection beam 40 may have a parallelepiped-shaped cross-section, for example a rectangle. The computer devices 2 then bear against the upper face of the injection beam 40.

[0034] Each injection beam 40 may, for example, have a height (dimension along a vertical axis) of approximately 20 mm and a width (dimension along an axis normal to the front wall 7) of approximately 100 mm and be made of stainless steel. The length (dimension along an axis normal to the transverse walls 6) of the beams injection 40 is preferably equal to the length of the front / rear wall 7 on which they are mounted.

[0035] Advantageously, a width of 100 mm allows nineteen-inch computer devices 2 to be installed on a tray configured to receive twenty-one-inch computer devices 2.

[0036] In one embodiment, the installation 1 further comprises a filtering tank 12 comprising a first compartment 22 and a second compartment 23 separated by a central wall 24, an opening 25 being formed in the central wall 24 so as to put the first compartment 22 and the second compartment 23 into fluidic communication; - means for supplying the dielectric fluid 4 from the immersion tank 3 to the first compartment 22 of the filter tank 12; and - a filter 26 mounted in the opening 25 of the central wall 24.

[0037] In addition, the pump 10 is connected to a suction port 32 which opens into the lower compartment 23 in order to draw the dielectric fluid after it has passed through the filter 26.

[0038] The lower compartment 23 preferably extends below the upper compartment 22 so that the lower compartment 23 and the upper compartment 22 are stacked one above the other along the vertical axis, allowing the dielectric fluid 4 to pass through the filter 26 and flow into the lower compartment 23 by gravity. The volume of the lower compartment 23 may be greater than the volume of the upper compartment 22 so that it serves as a reservoir for the dielectric fluid 4.

[0039] The filter tank 12 further has a bottom wall 20, side walls 21, 7 extending from the bottom wall 20, and an opening. Moreover, the cover of the installation 1 is configured to also cover the opening of the filter tank 12.

[0040] This configuration thus makes it easier to maintain the filter 26. Indeed, the filter 26 is easily accessible and removable from the opening of the filter tank 12, without requiring the dismantling of any part of the installation 1.

[0041] The filter 26 may, for example, comprise a fine-mesh stainless steel sieve, typically with a mesh size of 0.5 mm or less. For example, the filter may be a stainless steel strainer with a mesh size of 0.5 mm. This type of filter is indeed easy to clean.

[0042] The pump 10 discharges the filtered dielectric fluid 4 and sends it to the heat exchanger 11, for example, a 50 kW to 100 kW oil / water heat exchanger, in order to obtain a temperature difference of at least 13°C between the inlet and outlet of the dielectric fluid 4, given that the maximum target operating temperature of the dielectric fluid 4 is 60°C. The temperature of the dielectric fluid 4 The temperature of the water entering the heat exchanger 11 can be between 30°C and 45°C, and its outlet temperature can be between 45°C and 60°C (depending on external weather conditions). The temperature of the cold water entering the heat exchanger 11 is preferably less than or equal to 40°C (30°C in winter), and the outlet temperature, after heat exchange with the dielectric fluid 4, can be in the range of 45°C to 55°C. Once cooled, the dielectric fluid 4 is returned to the immersion tank 3 via the injection ports 41 of the injection beams 40. In this way, the dielectric fluid 4 is distributed homogeneously in the lower part of the immersion tank 3 and spreads under the computer devices before naturally rising by convection along the computer devices 2 to cool them by heat transfer.The dielectric fluid 4 is therefore gradually heated by the computer devices 2 until it reaches the surface of the immersion tank 3.

[0043] In one embodiment, the means for supplying the dielectric fluid 4 include an additional pump configured to draw hot dielectric fluid 4 from the upper part of the immersion tank 3 and discharge it into the upper compartment 22 of the filter tank 12. The filter tank 12 can therefore be contiguous with the immersion tank 3 or extend at a distance from the immersion tank 3, depending on the configuration of the lines connecting the additional pump to the tanks 3 and 12.

[0044] In another embodiment, illustrated in the figures, the means for supplying the dielectric fluid can be passive and operate by overflow. For this purpose, the filter tank 12 is placed in the immediate vicinity of the immersion tank 3 in the installation 1 so that the filter tank 12 and the immersion tank 3 share a common wall 7. The filter tank 12 can, for example, extend along the entire length of the immersion tank 3. The filter tank 12 and the immersion tank 3 are therefore part of the same vessel and are simply separated by the common wall 7. In addition, a window 13 is formed in the common wall 7 to establish fluidic communication between the immersion tank 3 and the filter tank 12. The window 13 has a lower edge 14 (bottom side) and an upper edge (lid side) which are connected by lateral edges.Finally, the level of dielectric fluid 4 in the immersion tank 3 is greater than the level of fluid 3 in the filter tank 12 so that the dielectric fluid 4 flows out through the window 13 into the filter tank 12 when its level reaches the lower edge 14 of the window 13.

[0045] By fluid level 3, we will understand here the distance, measured along an axis normal to the horizontal support, between the support and the surface of fluid 3.

[0046] The adjustment of the fluid level 3 in the immersion tank 3 is therefore passive and dictated by the position of the lower edge 14 of the window 13. Indeed, as soon as the fluid level 3 reaches the lower edge 14 of the window, the excess of Dielectric fluid 4 overflows and automatically flows into the filter tank 12, thus ensuring a stable and controlled fluid level 3 in the immersion tank 3.

[0047] The window 13 can extend over all or part of the length of the common wall 7. Here, "length" refers to the dimension of the common wall 7 in a plane parallel to the ground between the two lateral walls 6 that are connected to the common wall 7. Alternatively, the window 13 can be segmented and formed of several disjoint window segments 13 distributed along the length of the common wall 7. This configuration makes it possible to stiffen the common wall 7, while ensuring that the windows can maintain the desired level of dielectric fluid in the immersion tank 3.

[0048] The cooling circuit(s) are preferably located outside the immersion tank 3 and the filter tank 12. For example, all or part of the cooling circuits may be located in a technical compartment 27, which may be adjacent to the filter tank 12 or 28 located at a distance from the filter tank 12. In the embodiment illustrated in the figures, the technical compartment 27 is contiguous with the immersion tank 3 and overflow tank 12 and extends across the width and height of the tanks 3 and 12. This technical compartment 27 includes the two pumps 10, the two heat exchangers 11, and the pipes connecting the pumps 10 to the filter tank 12 and to the heat exchangers 11. This embodiment facilitates maintenance of the immersion tank 3 and overflow tank 12 by allowing easy access to the cooling circuit.

Claims

Demands

1. Installation (1) comprising: - an immersion tank (3) configured to receive a dielectric fluid (4) and comprising retaining means (8) configured to receive computer devices (2) such that the computer devices (2) are immersed in the dielectric fluid (4); - a cooling circuit comprising: - a pump (10) configured to draw dielectric fluid into the installation (3); and - an injection beam (40) fluidically connecting the pump (10) to the immersion tank, the injection beam (40) comprising a series of orifices (41) distributed along its length so as to inject dielectric fluid (4) discharged by the pump (10) into the immersion tank (3); the injection beam (40) extending over all or part of a length of a wall (7) of the immersion tank (3) by being mounted in the immersion tank (3) between a bottom (5) of the immersion tank and the computer devices (2).

2. Installation (1) according to claim 1, wherein an upper face of the injection beam (40) is configured to come into contact with the computing devices (2) so as to form a support for the computing devices (2).

3. Installation (1) according to claim 2, wherein a cross-section of the injection beam (40) is parallelepiped.

4. Installation (1) according to any one of claims 2 and 3, further comprising at least one computer device (2) immersed in the dielectric fluid (4) and mounted in the retaining means (8), the computer device (2) bearing on the upper face of the injection beam (40).

5. Installation (1) according to any one of claims 1 to 4, wherein the injection beam (40) comprises at least as many orifices (41) as the immersion tank (3) is configured to receive computing devices (2), each orifice (41) opening near a corresponding computing device (2).

6. Installation (1) according to any one of claims 1 to 5, comprising an additional injection beam (40) placed on a wall additional (7) of the immersion tank (3) extending opposite the wall (7), the additional injection beam (40) fluidly connecting the pump (10) to the immersion tank (3) and comprising a series of additional orifices (41) distributed along its length so as to inject dielectric fluid (4) discharged by the pump (10) into the immersion tank (3); the additional injection beam (40) extending over all or part of a length of the additional wall (7) of the immersion tank by being mounted in the immersion tank (3) between the bottom (5) of the immersion tank and the computer devices (2).

7. Installation (1) according to any one of claims 1 to 6, further comprising: - a filter tank (12) comprising a first compartment (22) and a second compartment (23) separated by a central wall (24), an opening (25) being formed in the central wall (24) so ​​as to put the first compartment (22) and the second compartment (23) into fluidic communication; - means for supplying the dielectric fluid (4) from the immersion tank (3) to the first compartment (22) of the filter tank (12); - a filter (26) mounted in the opening (25) of the central wall (24) for filtering the dielectric fluid (4) which flows towards the second compartment (23); the pump (10) being configured to draw dielectric fluid (4) into the second compartment (23).

8. Installation (1) according to claim 7, wherein the filter tank (12) is separated from the immersion tank (3) by a separating wall (7) and the supply means comprise a window (13) which is formed in the separating wall (7) so as to put the immersion tank (3) and the filter tank (12) into fluidic communication, a level of dielectric fluid (4) in the immersion tank (3) being greater than a level of dielectric fluid (4) in the filter tank (12) so that the dielectric fluid (4) flows through the window (13) into the filter tank (12) when its level reaches a lower edge (14) of the window (13).

9. Installation (1) according to claim 7, wherein the supply means comprise an additional pump configured to

10. to draw dielectric fluid into the immersion tank (3) and discharge it into the first compartment (22) of the filter tank (12). Data center comprising an installation (1) according to any one of claims 1 to 9 and computer devices (2) mounted in the retaining means (8).

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