US20100141105A1 - Thermal Management Cabinet for Electronic Equipment - Google Patents

Abstract

A thermal management cabinet for electronic equipment such as servers, having an opening in the top and bottom of the cabinet. The cabinet extends between a raised access floor of a building carrying cooled air and a drop ceiling for venting heated air. The bottom opening of the cabinet is alignable with an opening in the access floor such that cool air can pass into the cabinet and can flow through the electronic component storage area to the top opening, which is alignable with an opening in the drop ceiling. The cabinet interior is separated into temperature zones comprising at least a cold zone supplied with air from the access floor and a hot zone for venting through the top opening. At least one baffle creates the temperature zones such that air is directed to flow from the cold zone through the electronic component storage area to the hot zone.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This is a non-provisional application of provisional application Ser. No. 61/119,980 filed Dec. 4, 2008.
FIELD OF THE INVENTION
• The present application relates to thermal management cabinets for electronic equipment, and particularly to a cabinet system designed to aid in cooling servers and other computing equipment.
BACKGROUND
• Data centers typically involve a large number of rack-mounted servers that are housed together in cabinets. Cooling of such server racks and cabinets is a major problem, particularly as processors typically produce large amounts of heat. It has been found that for every 1 watt of power used for Information Technology, 0.5 to 2 watts of power are used for cooling the electronic components, and thus the need for cooling uses a very high percentage of the total IT power consumption. The power dissipation of high-performance CPU processors is predicted to exceed 150 W in the near future. The high-density packing of servers and the desire for lower CPU junction temperatures to achieve higher reliability of components means that thermal management of server racks is an increasing concern. Various solutions have been proposed, many of which involve large numbers of fans to keep a constant airflow over the electronic components. However, such solutions suffer from drawbacks associated with the power supply needed to power the fans, as well as reliability of such fans.
• In a number of solutions, server cabinets are placed on a false floor with cool air from an HVAC system being supplied through the false floor to a vent in front of the cabinet. The cooling airflow is then drawn front-to-back through the cabinet using fans, and vented out to the back of the cabinet. With such arrangements, it is desirable to use a “hot-aisle/cold-aisle” arrangement so that server fronts are arranged facing one another so that two aisles can draw cool air from a single vent area, and so that the server backs also face one another. The hot air is then allowed to vent to air return units in the ceiling. This can lead to “hot spots” in the server room, however, much of the hot air can also mix with the cool air circulating in the room. Various solutions to such problems involve the use of baffles extending from the top of the server cabinet to the ceiling to try to prevent some of the mixing between the hot and cold air.
• The maximum allowed temperature range for a server in a data center is 59 to 90 degrees Fahrenheit, while the recommended temperature is between 68 and 77 degrees Fahrenheit. As the known data center storage solutions typically allow some mixing of air prior to the air reaching the electronic components, data centers typically pump cold air at between 55 and 60 degrees Fahrenheit to account for the temperature increase in the air before it can act to cool the components. The American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) has suggested that it would be beneficial if cold air could be conveyed directly to servers without mixing with hot air, which would allow the cooled air to be provided from the air handler to be warmer while still allowing the server temperature to remain within the recommended standard temperature ranges.
SUMMARY
• In accordance with one aspect of the exemplary embodiments, a thermal management cabinet for electronic equipment includes a cabinet frame having side walls and defining a front, a back, a top and a bottom, the cabinet forming a generally sealed enclosure for electronic equipment. An electronic component storage area including at least one shelving rack for supporting electronic equipment is defined in an interior section of the cabinet. At least one opening is included in the top of the cabinet, and at least one opening is included in the bottom of the cabinet. The cabinet is dimensioned to extend between a raised access floor of a building and a drop ceiling of a building, the access floor carrying cooled air and the drop ceiling venting heated air. The bottom opening of the cabinet is alignable with an opening in the access floor such that cool air from the access floor passes into the cabinet and flows through the electronic component storage area to exit the cabinet through the top opening, which is alignable with an opening in the drop ceiling.
• The cabinet interior can be separated into temperature zones comprising at least a cold zone supplied with air from the bottom opening of the cabinet and a hot zone for venting through the top opening, with at least one baffle provided to create the temperature zones such that air is directed to flow from the cold zone through the electronic component storage area to the hot zone.
• In one arrangement, the baffle can comprise a thermal management plate that is positioned horizontally in the cabinet above the electronic component storage area. The thermal management plate can be formed of insulated material such as a plastic material backed with an insulator.
• In another arrangement, the baffle can comprise a heat transfer curtain that is positioned vertically in the cabinet above the electronic component storage area. The heat transfer curtain can be formed of a composite material.
• In another arrangement, the baffle can be flexible and can allow cables to be passed through areas of the cabinet while providing a heat transfer barrier. The flexible baffle can comprise at least one of flexible fingers, foam insulation and brushes. The flexible fingers and brushes can extend from the electronic component storage area to at least one of the side walls, front and back of the cabinet. The at least one foam insulation can comprise two flexible foam pieces positioned to allow cables to be passed therebetween.
• A duct can extend from the top opening of the cabinet for connection to a drop ceiling. The duct can be formed of a flexible material such as a fabric material.
• At least one door can be provided in at least one of the front and back of the cabinet. The at least one door can be a double door. Insulation pieces can be provided adjacent at least one hinged edge of the at least one door. The insulation pieces can form a flexible baffle, and can comprise two flexible foam pieces positioned to allow cables to be passed therebetween.
• At least one side of the cabinet can include a removable panel. At least one punch hole having a removable plug can be provided in at least one side of the cabinet.
• At least one airflow management structure can be provided adjacent to the bottom opening of the cabinet, which may be a perforated curtain.
• The above-described and other features and advantages of the present disclosure will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective isometric view of a thermal management cabinet according to arrangements of the present invention, with side panels removed.
• FIG. 2 is a perspective isometric view of the thermal management cabinet ofFIG. 1 with doors and baffles removed.
• FIG. 3 is a side view of the thermal management cabinet ofFIG. 1.
• FIG. 4 is a perspective isometric view of the thermal management cabinet ofFIG. 1, with servers removed.
• FIG. 5 is a perspective isometric view of the interior components of the thermal management cabinet ofFIG. 1.
• FIG. 6 is a side perspective view of the interior components of the thermal management cabinet ofFIG. 1, showing the foam door seal.
• FIG. 7 is a side sectional view of the thermal management cabinet ofFIG. 1, showing example airflow patterns.
• FIG. 8 is a front perspective view of an alternative arrangement of thermal management cabinet according to the invention.
• FIG. 9 is a side sectional view of the thermal management cabinet ofFIG. 8, showing example airflow patterns.
• FIG. 10 is a view showing the flexible fingers used in the thermal management cabinet ofFIG. 1.
• FIG. 11 is a bottom view of a modular base for the thermal management cabinet ofFIG. 1.
• FIG. 12 shows a perforated curtain for use in the thermal management cabinet according to the present invention.
• FIG. 13 is a side view showing airflow plates for use in the thermal management cabinet according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
• The exemplary embodiments of the present disclosure are described with respect to a thermal management cabinet for electronic equipment. It should be understood by one of ordinary skill in the art that the exemplary embodiments of the present disclosure can be applied to other types of thermal management systems.
• Referring to the drawings, an exemplary thermal management cabinet is illustrated. Thecabinet10 has generallysolid side walls12, a front14 and a back16. The cabinet may be used to house a plurality ofservers15 or other pieces of electronic equipment. Suitable dimensions for the cabinet include a height of 7 feet, a width of 3 feet and a depth of 4 feet, although it will be appreciated that the dimensions can be varied to suit any particular application.
• Thecabinet10 may include generally L-shapedhorizontal rails17 attached to and supported by four vertical rail supports18 which form part of aframe19 that is positioned in the interior of thecabinet10. A plurality ofrails17 may be provided in pairs to form shelving brackets on which electronic components can be supported. The rails may have any suitable formation, one suitable formation being standard square hole rails that may be positioned 19″ apart to form a 19″ rack. The rails may be mounted to the vertical rail supports18 and define the depth of the racks for housing theelectronic components15. The vertical rail supports18 and therails17 define an electroniccomponent storage area20 that is located within theframe19. The positioning of theframe19 defines afront service area21 forward of the frame to thefront14 of the cabinet, arear service area22 rearward of the frame to theback16 of thecabinet10. Twoside service areas23 are defined to the sides of theframe19. The cabinet can be designed to be 42 U in height, with “U,” or rack unit, being a unit of measure used to describe the height of equipment intended for mounting in a 19-inch rack or a 23-inch rack (the dimension referring to the width of rack). One rack unit is 1.75″ (44.45 mm) high. Thus, a suitable number ofrails17 can be provided to equal the desired height of the cabinet, with the rails being spaced a suitable number of rack units apart.
• An insulatedthermal management plate24 can be provided, which can be moved within thecabinet10. Thethermal management plate24 can be formed of any suitable material. In one arrangement, theplate24 can be formed of ABS plastic with a foam insulation backing. Thethermal management plate24 extends from thefront14 of thecabinet10 towards the back16, typically to the rearvertical rail support18 which marks the front end of therear service area22. The electronic components to be housed within thecabinet10 can be stored within the cabinet starting from the lowest rack and working upwards. Thethermal management plate24 is easily movable within the cabinet and is typically placed within thecabinet10 just above the height of the highest electronic component that is stored within thecabinet10. Theplate24 may be attached to therails17 that are positioned directly above the topmost electronic component, or may simply be rested thereon. At the front edge of thethermal management plate24, the corners may be cut off.
• An insulatedthermal curtain25 can be provided at theback16 of thecabinet10. Thethermal curtain25 is preferably made of a composite material, though can be formed of any suitable material. Thecurtain25 can be suspended from a spring loaded or ratchetedroller mechanism26 that is attached at the top of theframe19. Thecurtain25 can either be mounted within or adjacent to the rear rail supports18 such that it is located at the edge of therear service area22. Abottom bracket28 enables thecurtain25 to be easily raised and lowered. Typically, the curtain is lowered until it is level with thethermal management plate24. Thecurtain25 can be formed of a thermal insulating material that prevents heat transfer. U-markings30 may be provided on the curtain at 1.75″ intervals, along with a company logo for the cabinet manufacturer. With a 19″ rack width, thecurtain25 can be 20″ wide. Thecurtain25 can run in verticalU-shaped rails32 attached to the vertical rail supports18 such that the curtain provides a generally sealed barrier to the transport of air. It should be appreciated, that although the arrangement illustrated inFIGS. 1-7 hascurtain25 provided at theback16 of thecabinet10, it may alternatively or in addition be provided at the sides of the cabinet, and/or at only one of the front, back or sides of the cabinet. In the arrangement ofFIGS. 8-11, thethermal curtain25 is positioned at the front of thecabinet10.
• Thethermal management plate24 and thethermal curtain25 can be used to separate the interior space of thecabinet10 into different zones by forming baffles to the air flow and heat transfer. A cold zone is defined within thefront service area21, bounded at the rear by the electronic components that are stored within the racks, and at the top by thethermal management plate24. The front door, thesides12 and the bottom of thecabinet10 form the other boundaries of the cold zone. A hot zone is defined within therear service area22, bounded at the front by the electronic Components that are stored within the racks and by thethermal curtain25 that extends from the top of thecabinet10 to thethermal management plate24. Thesides12, the rear door, the bottom and the top of thecabinet10 form the other boundaries of the hot zone. A neutral heat zone is formed above the cold zone, defined between the top of thecabinet10, thethermal management plate24, thesides12 of the cabinet, the front door of thecabinet10 and thethermal curtain25. Thus, the hot zone typically forms the entire volume of therear service area22, while thefront service area21 and the electroniccomponent storage area20 are split vertically by the horizontally-orientedplate24 into the neutral heat zone at the top and the cold zone at the bottom. Air flow within the cabinet is designed to go first from the cold zone rearwardly through the electroniccomponent storage area20 where it becomes heated due to contact with the electronic components therein and exits into the hot zone. The air then flows vertically upwards within the hot zone to exit the cabinet. The neutral zone is designed to be cut off from this air flow by thethermal management plate24 and thethermal curtain25. The neutral zone formed above thethermal management plate24 can be used for storage for equipment such as laptops or other devices.
• In alternative arrangements, athermal curtain25 may be provided without provision of athermal management plate24, in which case the thermal curtain may be positioned to either the front or back of thestorage area20, or at any location therebetween such as at the center thereof. Thethermal curtain25 can be mounted to the top of the cabinet, and can be simply extended downwardly until it reaches the top-most electronic component stored in thestorage area20. This arrangement thus splits the interior of thecabinet10 into a hot zone and a cold zone by vertically dividing the space using thethermal curtain25.
• In further alternative arrangements, as shown inFIGS. 8 and 9, thethermal management plate24 can extend from thefront14 of the cabinet to the front vertical rail supports18, and thethermal curtain25 can be provided close to the front vertical rail supports. This creates a smaller neutral heat zone but still performs the function of preventing the cold zone from extending the full height of thecabinet10 when the electronic components are not necessarily stacked up to the top of thecabinet10.
• Adjacent to the vertical rail supports18 at the front14 and back16 of thecabinet10, a plurality ofair management fingers34 and/or brushes35 can be provided, which can extend to the sides or front/back of thecabinet10. The fingers can be formed of a non thermally conductive flexible material, such as a foam, rubber or plastic material. Thefingers34 can be generally rectangularly shaped and can be attached at one end only to a support which is attached the rail supports18. Each finger can be separately moveable, and can allow cables to be passed therethrough by pushing the cables inbetweenadjacent fingers34. Thebrushes35 can be similarly arranged, attached at one end only to the rail supports18. Alternatively, thebrushes35 can be provided on supports on either side of the gap between the rail supports18 and the sides/front/back of the cabinet such that the brushes meet in the middle. In one arrangement, a set offingers34 can extend from the rail supports18 to thesides12 of the cabinet at the rear edge of thefront service space21. A set ofbrushes35 can extend from the rail supports18 to the rear16 of thecabinet12. Theside service areas23 can thus be defined by thefingers34 and brushes35, such that they are bounded at the front by thefingers34, at the sides by thesides12 of the cabinet at the sides of the electronic components stored in thestorage area20 and thebrushes35, and at the rear by the rear16 of the cabinet. Theside service areas23 can thus be generally separated from the airflow in the cabinet by thefingers34 and/or brushes35, which form baffles, and theside service areas23 thus form secondary neutral heat zones. It will of course be appreciated that any arrangement of brushes and/or fingers can be employed to both provide a separation of the air flow from theside service areas23 and still to allow cables to be threaded into and through theside service areas23 for appropriate cable management purposes.
• In another arrangement, in place of or in addition tofingers34 or brushes35, flexiblefoam insulation pieces33 can be used. The foam pieces may be provided in two parts; a generally thin rectangular piece33amay be extended vertically from the cut corners of thethermal management plate24, and a generally triangular-section piece33bmay be attached to adoor36 of the cabinet. When thedoor36 is closed, the two foam pieces33aand33bcan abut one another. Cables can then be run from the electronic components stored on the rack through the abutting foam pieces33a,33b, to theside service areas23. Thefoam insulation pieces33 can thus form baffles between the cold zone and the neutral heat zone of theside service areas23.
• Thesides12 may each include one or more removable side panels to allow access between cabinets. Thesides12 and side panels may be constructed of lightweight composite materials with non thermal conductive properties. Insulation may also be provided on the side panels. In some arrangements, thesides12 may include one or more punch out panels so that cables may be run from servers stored in onecabinet10 to servers stored in anothercabinet10. As theside service areas23 are generally neutral air zones, it does not affect the cooling capabilities of the cabinet airflow to provide punch out holes in the sides.
• The back16 and the front14 may both include one ormore doors36. Thedoor36 may have a side hinge, and may be constructed of lightweight composite materials similar to thesides12, and may also be insulated. Alternatively, a double door may be provided, which has the advantage of allowing a decrease in necessary aisle space between cabinets that face one another. The door may include a temperature sensor that may be viewed without opening the door. The temperature sensor may be provided behind a window in the door, or may have a sensor part mounted inside the cabinet and a display part mounted on the outside of the door. The door may include a combination lock, or other locking mechanism. A rubber or other seal (not shown) may be provided around thedoors36, to help to seal any air gaps that might be created.
• Thecabinet10 may be mounted on amodular base37, forming a bottom38 of the cabinet. The base may measure 3′ wide by 4′ long, and may allow access to a raisedfloor system60 such as aTATE 24″×24″ modular access floor system. Afront section40 of thebase37 is open to the subfloor, and registers with corresponding openings that are created to the raised floor system. A plurality offeet42 are provided to bear the weight of the cabinet. A skirt (not shown) may surround the feet to prevent cool air from exiting around thebase37.
• An airflow duct orchimney44 may extend from a top46 of thecabinet10. Theduct44 can extend generally from an area of the top46 that is adjacent to theback16 of the cabinet. Theduct44 is dimensioned to extend into aceiling space62 such as an above-ceiling plenum for venting hot air to a venting means (not shown). Theduct44 may be flexible so that it can be easily connected to the ceiling even in the event of imperfect positioning of thecabinet10 below a vent panel into theceiling space62. In one arrangement, theduct44 can be formed of a flexible fabric or plastic material. Alternatively, theduct44 can be formed of a rigid material. Theceiling space62 may be a standard drop ceiling system. Various components can be provided in the top46 such as apower raceway47 and apublic communications raceway48, both of which may be open to the room. A divider49 may divide thepublic communications raceway48 for fiber and copper cables. Apatch panel50 can extend from the public communications raceway into aprivate communications raceway52 for pass through of cables into the interior of thecabinet10. Dividers53 may be included in theprivate communications raceway52 for dividing the space for fiber and copper cables.Junction boxes54 may be provided in the power raceway48afor supply of power to the power circuit in the cabinet. Power strips56 and cable managers58 may be provided adjacent theback16 of thecabinet10. It will be appreciated that the arrangement of components at the top46 of thecabinet10 can be varied to suit the particular application.
• In use, thecabinet10 is installed over a raisedaccess floor60 that is provided with cooled air from an HVAC or other system. Thebase37 is registered with openings in thefloor60. The chimney is extended into adrop ceiling62. The electronic components are installed onrails17, and are appropriately cabled by passing cables through thefoam pieces33,fingers34 and/or brushes35 into theside service areas23. Standard cable management ladders may be employed in theside service areas23 to hold the cables at the right height and to allow them to be passed to the tops of the cabinet. The cables are run to the top of thecabinet10 for connection to the power supply and to communications cables, which may be connected to other servers using standard overhead ladder racks. Thedoors36 are then closed. As the electronic components are operated, they generate heat which is forced to therear service area22 by the airflow coming into the cold zone of thefront service area21 of the cabinet via theaperture40 at the front of the cabinet. The hot zone created in therear service area22 due to the heating effect of the electronic components causes the air to flow up through theduct44. The air thus circulates from the cold zone, through the electronic components in thestorage area20 to the hot zone and up intoduct44. The various baffles such as thethermal management plate24,thermal curtain25 andfoam pieces33,fingers34 and/or brushes35 constrain the airflow into the smallest possible space within the cabinet, and prevent hot and cold air mixing other than through the electroniccomponent storage area20.
• In order to ensure that sufficient cool air is delivered to the upper most electronic components, one or more flow diverters can optionally be used. For example, aperforated curtain70 as shown inFIG. 11 or a series ofplates72 as shown inFIG. 12, may be used. Such arrangements can help to keep cool air flowing towards the top servers rather than allowing it all to be directed to the lower servers.
• The illustrations of arrangements described herein are intended to provide a general understanding of the structure of various embodiments, and they are not intended to serve as a complete description of all the elements and features of apparatus and systems that might make use of the structures described herein. Many other arrangements will be apparent to those of skill in the art upon reviewing the above description. Other arrangements may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. Figures are also merely representational and may not be drawn to scale. Certain proportions thereof may be exaggerated, while others may be minimized. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.
• Thus, although specific arrangements have been illustrated and described herein, it should be appreciated that any arrangement calculated to achieve the same purpose may be substituted for the specific arrangement shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments and arrangements of the invention. Combinations of the above arrangements, and other arrangements not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description. Therefore, it is intended that the disclosure not be limited to the particular arrangement(s) disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments and arrangements falling within the scope of the appended claims.
• The Abstract of the Disclosure is provided to comply with 37 C.F.R. §1.72(b), requiring an abstract that will allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Claims (20)

1. A thermal management cabinet for electronic equipment, comprising:

a cabinet frame having side walls and defining a front, a back, a top and a bottom, the cabinet forming a generally sealed enclosure for electronic equipment;

an electronic component storage area including at least one shelving rack for supporting electronic equipment in an interior section of the cabinet;

at least one opening in the top of the cabinet; and

at least one opening in the bottom of the cabinet;

wherein the cabinet is dimensioned to extend between a raised access floor of a building and a drop ceiling of a building, the access floor carrying cooled air and the drop ceiling venting heated air,

wherein the bottom opening of the cabinet is alignable with an opening in the access floor such that cool air from the access floor passes into the cabinet and flows through the electronic component storage area to exit the cabinet through the top opening, which is alignable with an opening in the drop ceiling.

2. The thermal management cabinet according toclaim 1, wherein the cabinet interior is separated into temperature zones comprising at least a cold zone supplied with air from the bottom opening of the cabinet and a hot zone for venting through the top opening, wherein at least one baffle is provided to create the temperature zones such that air is directed to flow from the cold zone through the electronic component storage area to the hot zone.

3-5. (canceled)

6. The thermal management cabinet according toclaim 2, wherein the at least one baffle comprises a heat transfer curtain that is positioned vertically in the cabinet above the electronic component storage area.

7. The system according toclaim 6, wherein the heat transfer curtain is formed of a composite material.

8. The thermal management cabinet according toclaim 1, wherein the at least one baffle is flexible and allows cables to be passed through areas of the cabinet while providing a heat transfer barrier.

9. The thermal management cabinet according toclaim 1, wherein the flexible baffle comprises flexible fingers.

10. The thermal management cabinet according toclaim 9, wherein flexible fingers extend from the electronic component storage area to at least one of the side walls, front and back of the cabinet.

11. (canceled)

12. The thermal management cabinet according toclaim 1, wherein a duet extends from the top opening of the cabinet for connection to a drop ceiling.

13. The thermal management cabinet according toclaim 12, wherein the duct is formed of a flexible material.

14. The thermal management cabinet according toclaim 13, wherein the duct is formed of a fabric material.

15. The thermal management cabinet according toclaim 1, wherein at least one door is provided in at least one of the front and back of the cabinet.

16. The thermal management cabinet according toclaim 15, wherein the at least one door is a double door.

17. The thermal management cabinet according toclaim 15, wherein insulation pieces are provided adjacent at least one hinged edge of the at least one door.

18. The thermal management cabinet according toclaim 15, wherein the insulation pieces comprise flexible foam bathes, the foam baffles being positioned to allow cables to be passed therebetween

19. The thermal management cabinet according toclaim 1, wherein at least one side of the cabinet includes a removable panel.

20. The thermal management cabinet according toclaim 1, wherein at least one punch hole having a removable plug is provided in at least one side of the cabinet.

21. The thermal management cabinet according toclaim 1, wherein at least one airflow management structure is provided adjacent to the bottom opening of the cabinet.

22. The thermal management cabinet according toclaim 21, wherein the airflow management structure comprises a perforated curtain.

Images