Air flow control in data storage systems

A cooling assembly includes an air mover and a vent panel coupled to the air mover. The vent panel includes an inlet. The cooling assembly includes a vane that is rotatable around a central vertical axis of the vane between an open position and a closed position to open and close the inlet.

SUMMARY

In certain embodiments, a cooling assembly includes an air mover, a vent panel coupled to the air mover and including an inlet opening, and a vane rotatable around a central vertical axis of the vane between an open position and a closed position to open and close the inlet opening.

In certain embodiments, a system includes an enclosure and a first cooling assembly coupled to the enclosure. The first cooling assembly includes a first air mover, a first vent panel coupled to the first air mover and including a first inlet opening, and a first vane rotatable around a first shaft between a first open position and a first closed position to open and close the first inlet opening.

In certain embodiments, a method is disclosed for using a cooling assembly, which includes an air mover, a vent panel with an inlet opening, and a vane rotatable between an open position and a closed position to open and close the inlet opening. The method includes powering the air mover to pull air through the inlet opening on both sides of the vane in the open position. The method further includes rotating the vane around a central vertical axis of the vane to the closed position such that the vane closes the inlet opening.

DETAILED DESCRIPTION

Data storage systems utilize cooling devices such as air movers (e.g., fans, blowers) to keep components of the data storage systems within a desired operating range. When one of the air movers fails, the total volume of air flow is reduced, and the failed air mover exposes an open circuit through which unwanted backflow of air can enter the data storage systems. This open circuit can further reduce the total volume of air flow within the data storage system.

Currently, to compensate for the reduced air flow, data storage systems typically increase the speed at which the still-functioning air movers rotate and/or use motorized mechanisms to close the open circuit. However, these approaches require that the failure be detected (which may require additional components like sensors), require motorized mechanisms, and/or assume that increasing the speed of the other air movers can adequately compensate for the reduced air flow until the failed air mover can be replaced by a functioning air mover. Other approaches involve using flap- or wing-like structures that—with gravity—close when there is no positive air flow. However, approaches that rely on gravity require the air mover to use more power keep the flaps or wings open to overcome the force of gravity which reduces the efficiency of the air mover. Certain embodiments of the present disclosure are accordingly directed to approaches for helping to prevent backflow of air when air movers fail or otherwise malfunction.

FIG.1shows a data storage system100including a rack102(e.g., a cabinet) with a plurality of enclosures104. Each enclosure104can include multiple drawers or storage levels (each of which may be considered separate enclosures or sub-enclosures) that house electronic devices such as data storage devices installed within the drawers or storage levels. Each enclosure104itself can be arranged in a drawer-like fashion to slide into and out of the rack102, although the enclosures104are not necessarily arranged as such.

FIG.2shows an enclosure200, which can be utilized in a data storage system such as the data storage system100ofFIG.1. For example, a rack—such as the rack102inFIG.1—can include multiple individual enclosures, such as the enclosure200. The enclosure200is arranged to secure data storage devices202(e.g., hard disk drives and/or solid state drives), various electronics (e.g., power supplies), and cooling devices (e.g., air movers) among other things.

The enclosure200includes a chassis204with a first side wall206A, a second side wall206B, and a bottom wall206C. The chassis204may also include front and rear walls along with a top cover to enclose the data storage devices202within the enclosure200. As shown inFIG.2, the enclosure200can include multiple data storage levels208A-C each with multiple rows of data storage devices202. Each data storage level208A-C may be arranged to slide into and out of the enclosure200in a drawer-like fashion. Further, each data storage level208A-C can form its own enclosure such that the enclosure200can be considered to include multiple, smaller enclosures arranged to slide into and out of the enclosure200. The enclosure200includes a front end210A and a back end210B with a cooling area212at the back end210B of the enclosure200.

FIG.3shows a cutaway, schematic side view of the back end2106of the enclosure200. The enclosure200includes a back wall214on which several cooling assemblies216are positioned. Exemplary cooling assemblies and their various features are shown inFIGS.4-10and described in additional detail below. In short, the cooling assemblies216are arranged to pull air from the front end210A of the enclosure200towards the back end2106of the enclosure200. As the air moves within the enclosure200, the air cools the various electronic devices positioned within the enclosure200. The cooling assemblies216shown inFIG.3are coupled to the back wall214of the enclosure200such that all or a majority of each of the cooling assemblies216is positioned outside the enclosure200. The dotted arrows inFIG.3represent air flowing into the cooling assemblies216from the interior of the enclosure200and exiting the cooling assemblies216along generally radial directions.

FIG.4shows an exploded view of a cooling assembly300, which can be installed in an enclosure such as the enclosure104ofFIG.1and the enclosure200ofFIGS.2and3.

The cooling assembly300includes an air mover302(e.g., a fan unit such as a radial blower unit or an axial fan unit; a blower). The air mover302can include blades304shaped and arranged such that—when the blades304rotate around a rotation (or inlet) axis306(shown in dotted lines inFIG.4)—the blades304pull air through an inlet side308of the air mover302and exhaust the air radially from the rotation axis306. As such, when the cooling assembly300is installed to an enclosure like the cooling assemblies216ofFIG.3, the air is pulled from inside the enclosure200and exhausted in a radial direction outside the enclosure200. In certain embodiments, the air mover302is a radial fan, which may be able to exhaust a larger volume of air for a given amount of power compared to air movers that are axial fans. The air mover302can include a motor that is electrically coupled to a power supply in an enclosure and that is coupled to the blades304to rotate the blades304.

The cooling assembly300includes a member such as a vent panel310with an inlet opening312. When the cooling assembly300is assembled, the vent panel310can be coupled to (e.g., clipped to, fastened to) another member such as a back cover316. The back cover316includes a back wall318and four side walls320with exhaust openings322throughout the side walls320. Although the back cover316is shown as including the side walls320and the exhaust openings322, the vent panel310could include side walls and exhaust openings instead of or in addition to those of the back cover316. Alternatively, a separate component could be coupled between the vent panel310and the back cover316and include exhaust openings, etc. The air mover302can be coupled to the back cover316via fasteners that extend through one or more of the rear mounting holes in the back cover316and couple to holes in the air mover302. The cooling assembly300also includes an inlet ring324positioned between the air mover302and the vent panel310. The inlet ring324can direct air entering the cooling assembly300through the inlet opening312to the air mover302. In certain embodiments, the inlet ring324helps reduce or prevent the air mover302from pulling air through parts of the cooling assembly300other than through the inlet opening312.

The cooling assembly300further includes a vent326(or vent assembly). The vent326includes a shaft328and a vane330. When the vent326is coupled to the vent panel310, the vent326is rotatable around a central vertical axis332of the vent326between an open position and a closed position to open and close (or otherwise seal) the inlet opening312. In certain embodiments, the shaft328is coupled to the vent panel310such that the shaft328itself does not rotate within the vent panel310. Instead, in such embodiments, the shaft328is stationary and the vane330is rotatably coupled to the shaft328. For example, the shaft328may extend through an opening in the vane330such that the vane330is free to rotate around the shaft328. In certain embodiments, the shaft328comprises a metallic material and the vane330comprises a plastic material so that, when the vane330rotates around the shaft328, there is no metal-to-metal contact.

As shown inFIG.4, in certain embodiments, the vent panel310includes only one inlet opening312. In such embodiments, the cooling assembly300can include only one vent326. When the vent326is installed in the cooling assembly300, the shaft328extends through one or more gaps, holes, or openings334in the vent panel310.

FIGS.5and6show various views of the cooling assembly300when the vent326is in the closed position. In the closed position, the air mover302has malfunctioned or is otherwise not operating to its full capability such that air336(represented with arrows) is entering—instead of exiting—the cooling assembly300through the exhaust openings322. For example, if an enclosure includes multiple cooling assemblies300, the cooling assemblies300operating will create a negative pressure that pulls air in a reverse direction through the non-operating cooling assemblies300.

As shown inFIG.5, the vane330is shaped to match the shape of the inlet opening312. In certain embodiments, the vane330and in the inlet opening312is circular-shaped. As such, when circular-shaped, approximately one half of the circular-shaped vane330can be positioned on one side of the shaft328approximately the other half of the circular-shaped vane330is positioned on the other side of the shaft328, which can extend through a center of the vane330.

In the closed position, the vent326is positioned such that the vent326(e.g., via the vane330) closes or otherwise provides a seal with the inlet opening312in the vent panel310such that little to none of the air336passes through the inlet opening312and into an enclosure. For example, the vent326can be coupled to the vent panel310such that the air336cannot pass through the inlet opening312. In certain embodiments, a gasket338(e.g., a tape-like gasket, which represented inFIG.7) is applied to a surface of the vane330or near the outer perimeter of the vane330and/or applied to a surface of the vent panel310such that the gasket338helps provide a seal between the vane330and the vent panel310.

The vent326rotates from the open position (shown inFIGS.7-10described below) to the closed position when the air mover302is not operating properly. When the air mover302is not operating, the air336flows in a reverse direction into the cooling assembly300(e.g., into the cooling assembly300through the exhaust openings322).

In certain embodiments, the vane330includes an interior-facing surface340on one side of the shaft328that has a larger surface area than the interior-facing surface340on the other side of the shaft328. The air336flowing in the reverse direction will create more pressure on the larger surface area side of the interior-facing surface340and will cause the vane330to rotate shut. Put another way, as the air336impinges on the interior-facing surface340of the vane330, the vane330rotates (e.g., clockwise or counterclockwise) around the central vertical axis332and closes the inlet opening312.

Additionally or alternatively, in certain embodiments, the vane330is coupled to or includes one or more pockets or cup-shaped structures342(e.g., structures with an opening on one side and closed on another side) that are arranged to “catch” the air336when the vane330is in the open position and help cause the vane330to rotate to the closed position. Put another way, the air336can flow into the one or more pockets342and provide a force that causes the vane330to rotate to the closed position. The pockets342can be arranged to “catch” the air336flowing in the reverse direction (e.g., via an open-side of the pocket342) when the vent326is open but allow the air336to flow in a positive direction over the exterior surface of the pockets342(e.g., over a closed-side of the pocket342) when the vent326is open.

Using the pockets342and/or the larger surface area, the vent326(e.g., via the vane330) can rotate between the open position and the closed position without use of gravity. As such, in the open position, the air mover302can use less power to keep the vent326open compared to approaches that rely on gravity for closing flaps or wings when an air mover is not operating.

FIGS.7-10show various views of the cooling assembly300when the vent326is in the open position. In the open position, the air mover302is operating and drawing the air336into the cooling assembly300through the inlet opening312in the vent panel310, through the inlet ring324, through the air mover302, and out of the cooling assembly300through the exhaust openings322. When the vent326is in the open position, the air336can flow parallel to the rotation axis306(shown inFIGS.8and10). This parallel airflow can reduce overall turbulent air flow, which allows the air mover302to operate more efficiently. As shown inFIG.10, in the open position, the vane330can be rotated 90 degrees from the closed position. For example, the interior-facing surface340of the vane330can extend perpendicular to a plane of a front surface348of the vent panel310. As such, the air336can flow through the inlet opening312on both sides of the vane330.

As shown inFIG.7, the vane330includes an outer lip portion344. When the vane330is in the closed position, the outer lip portion344can overlap with a recessed surface346of the vent panel310. The recessed surface346can be recessed from the front surface348of the vent panel310. In certain embodiments, the outer lip portion344extends around only a portion (e.g., approximately half) of the vane330.

The cooling assembly300shown in the figures and described above provides approaches for limiting the back flow of air through the cooling assembly300in the event the air mover302fails or misfunctions. The cooling assemblies300can include the vent326that opens and closes (e.g., via the vane330) based on the flow of air impinging on the vent326(e.g., positive or negative flow). Further, the vent326can open and close via positive or negative air flow without necessarily using the force of gravity. While the disclosure illustrates the cooling of a data storage enclosure, in other embodiments the cooling assembly300may be used to other types of enclosures such as enclosures that feature electronics other than data storage devices (e.g., processors, power supply units).

FIG.11shows a block diagram of a method400for using the cooling assembly300described above. The method400includes powering the air mover302to pull air through the inlet opening312on both sides of the vane330in the open position (block402inFIG.11). The method400also includes rotating the vane330around the central vertical axis332of the vane330to the closed position such that the vane330closes the inlet opening312(block404inFIG.11).

Various modifications and additions can be made to the embodiments disclosed without departing from the scope of this disclosure. For example, while the embodiments described above refer to particular features, the scope of this disclosure also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present disclosure is intended to include all such alternatives, modifications, and variations as falling within the scope of the claims, together with all equivalents thereof.