Chassis cooling system

According to some embodiments, an apparatus includes a chassis to house a plurality of electronic cards, a backplane housed in the chassis, and a fan housed in the chassis. A first portion of the fan may be lower than a top edge of the backplane, and a second portion of the fan may be higher than the top edge of the backplane.

BACKGROUND

Computing architectures may utilize a chassis to house electronic components. A chassis may provide protection against environmental hazards as well as a means for sharing systems among the components. For example, a desktop computer chassis may allow several components to share a power supply, a cooling fan, external communications interfaces, and/or other elements.

In another example, a modular server may include several distinct systems, or servers. The servers may be mounted in a chassis, which in turn may provide shared power, cooling, management and/or communications interfaces to the servers. Designers often seek to improve the efficiency of chassis-based architectures in terms of one or more of size, speed, cost, reliability, and other metrics.

DETAILED DESCRIPTION

FIG. 1Ais a view of chassis10according to some embodiments. Chassis10may comprise a telecommunications platform or any other type of device. Chassis10may be composed of any materials suitable for its intended use, including but not limited to plastic, steel, and aluminum. Physical dimensions of chassis10may also vary according to intended uses and/or specifications with which chassis10is intended to comply.

Sixteen electronic cards20are mounted within chassis10. Electronic cards20are secured to chassis10in part by mounting screws21. Cards20may be covered by a faceplate according to some embodiments. Electronic cards20may provide any functionality. In some embodiments, one or more of electronic cards20may comprise a server or a communications device. All of electronic cards20may be identical, or two or more of electronic cards20may be different from one another.

Electronic cards20may be coupled to one another via a backplane (not shown) that is also housed in chassis10. In a case that electronic cards20each comprise a server, the backplane may distribute power and provide management and data transport functions to electronic cards20. The arrangement of chassis10, electronic cards20, and the backplane may comply with the PCI Industrial Computer Manufacturers Group 3.0 Advanced Telecommunications Computing Architecture specification Rev. 1.0. Other architectures may also be employed in conjunction with some embodiments. Such architectures may be standardized to facilitate the interoperation of devices, chassis and systems of disparate manufacturers.

Chassis10includes inlet grate30of input plenum35. According to some embodiments, air is received into inlet grate30and input plenum35for cooling cards20. Such air may be sucked into inlet grate30and input plenum35due to the evacuation of air from inside chassis10by one or more fans housed in chassis10. This process will be described in detail below.

Access door40provides access to an output plenum of chassis10. According to some embodiments, fans may be removed from and replaced in chassis10through access door40. Chassis10may also comprise peripheral devices to provide shared functionality among cards20during operation. In some embodiments, the peripheral devices comprise one or more of a CD-ROM drive, a floppy disk drive, a keyboard, and a mouse.

FIG. 1Bis a view of rear panel50of chassis10. Rear panel50includes exhaust grate55. Exhaust grate55covers fans60through62, the positions of which are indicated in FIG.1B. Fans60through62may be used to draw air out of chassis10and to exhaust the air to the external environment.

Rear panel50also includes electronic modules70. Electronic modules70may attach to the backplane described above or may comprise portions of one or more of electronic cards20. Interface elements75may also attach to the backplane and may provide and/or directly to one or more of cards20. Electronic modules70and/or interface elements75may provide power, management, and I/O connections such as Ethernet and/or Fibre Channel to electronic cards20.

FIG. 2is a front cutaway view of chassis10according to some embodiments. Five electronic cards20are shown supported within respective ones of guide rails22through26, which are in turn supported by their attachment to the side walls of chassis10. Guide rails22through26may be components of a subrack that also includes structures for receiving input grate30and for supporting backplane80. Each of cards20is also connected to a front side of backplane80and physically supported thereby. Other arrangements may be used to support cards20according to some embodiments. Any number of cards may be used in some embodiments.

A dotted line indicates that input plenum35extends to a bottom surface of guide rails25through29. However, input plenum35may be considered to extend anywhere within chassis10, including but not limited to top edge85of backplane80. Similarly, a dotted line indicates that output plenum90extends downward to top edge85, but may also be considered to extend to any vertical location within chassis10.

Fans65through67are disposed within output plenum90. In the illustrated embodiment, fans65through67are disposed between fans60through62and backplane80, and thereby obscuring fans60through62in the present view. The positions of fans65through67will be understood in more detail after the following description of FIG.4. However,FIG. 2shows that first portions (not shown) of fans65through67may be lower than top edge85of backplane80and second portions of fan65through67may be higher than top edge85.

FIG. 3is a block diagram of electronic card20according to some embodiments. Electronic card20ofFIG. 3comprises a hardware server packaged within a thin enclosure. Embodiments are not limited to such an electronic card.

Electronic card20includes processors201and202, such as Intel Xeon™ processors. Processors201and202are coupled to Double Data Rate Random Access Memory203. Hard disk drives204and205may store software applications, data files, device drivers, and an operating system for controlling basic functions of electronic card20. Ethernet controller206allows electronic card20to communicate with other devices via Ethernet protocol. Backplane interface207may couple card20to backplane80, and may include interfaces for power distribution, card management, and data transfer. As mentioned above, electronic card20need not include each element shown, and may include elements other than those shown.

FIG. 4is a cutaway side view of chassis10according to some embodiments. Electronic cards20have been removed from chassis10in theFIG. 4view. Also in contrast to theFIG. 2view,FIG. 4shows connector87attached to a front side of backplane80. Connector87allows an electronic card20to be received by the front side of backplane80and allows the exchange of signals between backplane80and the electronic card20. According to some embodiments, backplane80comprises two or more connectors to receive the electronic card20.

FIG. 4also shows fan60fromFIG. 1B. Afirst portion of fan67and a first portion of fan60are lower than top edge85of backplane80. Moreover, a second portion of fan67and a first portion of fan60are higher than top edge85. Also, a portion of a rear side of backplane80is disposed between the first portion of fan67and a portion of the front side of backplane80. A portion of the rear side of backplane80is also disposed between the first portion of fan60and a portion of the front side of backplane80.

Some embodiments may provide efficient cooling and allow the use of larger fans for a given height of chassis10. For example, a height of input plenum35may be 2 U (U=1.75″), a height of output plenum may be 2 U, and a remainder of chassis10may be 8 U in height. A conventional arrangement may utilize fans having a height of 2 U, whileFIG. 4shows an embodiment in which fans65and60are greater than 2 U in height. Alternatively, fans65and60may be as large or larger than conventional fans, but a height one or both of input plenum35and output plenum90may be less than a conventional height due at least in part to improved cooling provided by some embodiments. In one specific example, a height of each of fans65and60is 3.5 U, a height of each of input plenum35and output plenum90is 1 U, and a remaining height of chassis10is 8 U.

Output plenum90includes output plenum expansion area95, in which are disposed air diverter100, fan67, and fan60. Air diverter100may comprise any currently or hereafter-known element for diverting airflow. More specifically, air110is depicted inFIG. 4as entering input plenum35and rising as shown to output plenum90. Input plenum35may comprise an air filter (not shown) to filter air110as it enters input plenum35. Such air may serve to cool electronic cards20when they are installed in chassis10. According to some embodiments, air diverter100directs air110to enter fan67in a more even distribution than would otherwise result from the arrangement of chassis10. For example, a large majority of air110may enter an upper portion of fan67in some embodiments if not for the presence of air diverter100. Air diverter100may therefore divert air110toward a lower portion of fan67that is lower than top edge85of backplane80.

Some embodiments do not include air diverter100. According to some embodiments, a single air diverter is disposed between backplane80and fans65through67. One or more air diverters may also or alternatively be disposed between backplane80and each of fans65through67.

FIG. 5Ais a close-up view of air diverter100of FIG.4. Air diverter100may be composed of any suitable material or materials.FIG. 5Bshows a design of air diverter100that may be easier to fabricate and install than air diverter100of FIG.5A. In contrast, air diverter100ofFIG. 5Cmay comprise elements of an airfoil. Air diverter100ofFIG. 5Cmay therefore be more difficult to design and fabricate than the other illustrated air diverters. However, air diverter100ofFIG. 5Cmay provide for stronger and/or more controllable airflow through fans67and60and therefore better cooling of chassis10.

FIG. 6is a side cutaway view of chassis10illustrating the removal of fan67according to some embodiments. As shown, fan67may be removable from a front side of chassis10. For example, a technician may open access door40, reach into output plenum90, and rotate fan67toward the front side of chassis10. The dotted instances of fan67illustrate the removal thereof from the front of chassis10. Fans60through62,65, and66may be similarly removed from chassis10according to some embodiments.

FIG. 7is a view of component rack150supporting four instances of chassis10. Component rack150may comply with the Electronic Industries Association (EIA) standard specification 310-D-1992. Component rack150may be capable of supporting components having a total height of 42 U. The instances of chassis10shown inFIG. 7include input and output plenums of 1 U in height, for a total height of 10 U per chassis10. Component rack150may therefore support four instances of chassis10. In contrast, component rack150can support only three (or fewer) instances of a chassis having an overall height of 11 U or more.

FIG. 8is a side cutaway view of chassis11according to some embodiments. The elements of chassis111are similar to those described above with respect to chassis10with the exception of input plenum36and output plenum91. As shown, a height of input plenum36at the front of chassis11is greater that a height of input plenum36at any location between the front and the rear of chassis11. In contrast, a height of output plenum91at the front of chassis111is less than its height at any location between the front and the rear of chassis11.

Output plenum91includes plenum divider160. Plenum divider160comprises an upper surface of output plenum91and a lower surface of input plenum170, which is indicated by a dotted line. Input plenum170is an element of a chassis stacked above chassis11, and is illustrated to show how vertical space may be shared by plenums of two different chassis according to some embodiments. Similarly, plenum divider180comprises a lower surface of input plenum36and an upper surface of output plenum190, which is an element of a chassis upon which chassis11is stacked. The chassis depicted on top of and below chassis11may be identical to or may differ from chassis11. Moreover, the elements of chassis11that are numbered identically to elements of chassis10may comprise any of the variations described with respect to the identically-numbered elements.

In some embodiments, air200may provide adequate cooling because the shapes of plenums36and91roughly correspond to the distribution of airflow therein. Plenums36and91may, according to some embodiments, provide larger effective input and output plenums than conventional horizontally-split plenums having a same total height. Chassis11may therefore provide efficient cooling in a smaller vertical form factor than other systems.

According to some embodiments, input plenum36has a height of 2 U at the front of chassis11and a height of 0 U at the rear of chassis11, while output plenum36has a height of 0 U at the front of chassis11and a height of 2 U at the rear of chassis11. Such embodiments may effectively provide the cooling of a conventional system having a 2 U input plenum and a 2 U output plenum while adding only 2 U, rather than 4 U, to a chassis height.

FIG. 9is a side cutaway view of chassis11illustrating the removal of fan67according to some embodiments. Removal of fan67may require removal of plenum divider160, which may comprise a baffle that separates output plenum91from input plenum170. Similar to the procedure described above, a technician may open access door40, remove plenum divider160, rotate fan67toward the front side of chassis11, and remove fan67therefrom. Fan60may then be removed from chassis11according to some embodiments.

FIG. 10is a view of component rack250and four instances of chassis11. Base255supports the lowest one of chassis11so that the components of each chassis are correctly oriented. Base255also comprises an input plenum for the lowest instance of chassis11and may provide support for an air filter. Upper enclosure257may be coupled to an uppermost instance of chassis11because the area occupied by enclosure257is not being used as an input plenum by another chassis.

Component rack250may be a standard component rack for supporting components having a total height of 42 U. The input and output plenums of each chassis11may be 1 U in maximum height and the remaining height of each chassis may be 8 U, for a total height of 10 U per chassis11. Component rack250may therefore support four instances of chassis11.

The several embodiments described herein are solely for the purpose of illustration. Embodiments may include any currently or hereafter-known versions of the elements described herein. Therefore, persons skilled in the art will recognize from this description that other embodiments may be practiced with various modifications and alterations.