Abstract:
A cooling solution includes a system providing thermal energy dissipation for electronic equipment located in support racks or cabinets of a facility. According to one embodiment, the system is integrated with a facility where the support cabinets are locate. The system providing thermal energy dissipation includes a cooling loop, a fan unit for moving air across the cooling loop and one or more ducts forming a confined flow pathway for the moving air between the fan unit and cabinets for delivery to the electronic equipment. More specifically, the cooling loop contains a supply of circulating heat absorbing fluid such that the heat absorbing fluid removes thermal energy from the air moved by the fan unit. Each cabinet is formed with an exhaust pathway such that the moving air enters the cabinet from the duct, flows across the electronic equipment to remove thermal energy therefrom, and exits the cabinet.

Description:
SUMMARY 
   This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
   A cooling solution for electronic equipment located in support racks or cabinets is provided. In particular, the cooling solution includes a system and method that is well suited for providing thermal energy dissipation for computing equipment handing telecommunications and general networking activity, such as servers, routers, printed circuit boards, and the like. 
   In one aspect, a cooling system is integrated with a facility in which support cabinets are located on a surface of a facility (e.g., an elevated or raised floor, or a typical structural floor). The system includes a cooling loop as well as a fan unit located within or beneath the facility surface. The cooling loop contains a supply of circulating heat absorbing fluid and the fan unit is configured to move air across the cooling loop such that the heat adsorbing fluid removes thermal energy from the moving air. Additionally, the system includes one or more ducts forming a confined flow pathway for the moving air between the fan unit and cabinets. Each cabinet is formed with an exhaust pathway such that the moving air enters the cabinet from the duct, flows across the electronic equipment to remove thermal energy therefrom, and exits the cabinet. Cooling plates equipped with a circulating supply of heat absorbing fluid may be strategically positioned within each cabinet to dissipate thermal energy from specific electronic equipment components, or may be located outside the cabinets and exposed to the exhaust pathway of the moving air leaving the cabinets in order to maintain a desired temperature environments within the room of the facility where the cabinets are located. Alternatively, a heat exchanger may be located outside of the cabinets and exposed to the exhaust pathway of the moving air, in order to utilize the thermal energy from the exhaust air to perform other functions. Still further, the cooling loop may include a chiller system for removing thermal energy from the circulating heat absorbing fluid that is exposed the air flow from the fan unit. 
   In another aspect, a method provides thermal energy dissipation for network-based electronic equipment housed within one or more cabinets located on a surface of a facility. Each cabinet has an interior formed with a through passageway extending from an entrance at a first side of the cabinet to an exit at a second side of the cabinet. According to the method, both a cooling loop containing a supply of circulating heat absorbing fluid and a fan unit are utilized. The fan unit is configured to move air across the cooling loop such that the heat absorbing fluid removes thermal energy from the moving air. The moving air is then directed from the fan unit to the through passageway of the at least one cabinet such that the moving air flows across the electronic equipment to remove thermal energy therefrom, and exits the cabinet. 
   Additional advantages and features of the invention will be set forth in part in a description which follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     The present invention is described in detail below with reference to the attached drawing figures, wherein: 
       FIG. 1  is a perspective view of an examplary electronic device support cabinet in which various types of electronic equipment are housed; 
       FIG. 2  is a schematic view of a cooling system for electronic equipment in accordance with one embodiment of the present invention; and 
       FIG. 3  is an perspective view of a chilling plate utilized with the cooling system of  FIG. 2 . 
   

   DETAILED DESCRIPTION 
   Embodiments of the present invention relate to a cooling solution for electronic equipment housed in support racks or cabinets within a facility. The cooling solution, although not limited to such an application, is well suited to provide thermal energy dissipation and management for equipment that produces a large amount of such energy, such as computers and other special purpose telecommunication or networking equipment. The solution provides a more targeted thermal energy dissipation scheme and preferably minimizes the floor space taken up in a facility for such cooling equipment. Additionally, the cooling solution may be positioned to maximize the thermal energy dissipation for the amount of cooling air flowing through the equipment housing cabinets. 
   Turning now to  FIG. 1 , an examplary electronic device housing rack, or cabinet  10 , is shown. The cabinet  10  has sidewalls  12 , a top cover  14  and a base  16 , as well as a plurality of shelves  18 . Each shelf  18  is mounted onto either the cabinet sidewalls  12  or to support columns  20  extending upwardly from the base  16 . Each shelf  18  is configured to support one or more electronic devices  22 , such as servers, routers, printed circuit boards, or other types of computing equipment. The electronic devices  22  are inserted into the cabinet  10  interior either through a front region  26  or a back region  24  of the cabinet  10 . It should be understood that the cabinet  10  is merely a practical example of one configuration for an electronic equipment housing apparatus, and that other configurations may be utilized in conjunction with the cooling solution of the present invention. 
   With additional reference to  FIG. 2 , one embodiment of a cooling system  100  of the present invention is depicted. The cooling system  100  generally includes a primary cooling loop  102 , a fan unit and intake housing  104 , and a ducting structure  128 , as well as the cabinets  10  housing the electronic equipment  22  producing the thermal energy. Additionally, a secondary cooling subsystem  106  may be provided proximal to (e.g., above) or within the cabinets  10  to act as a heat sink. 
   The primary cooling loop includes pipes  108 ,  110 ,  118 ,  120  for carrying a supply of heat absorbing fluid through a circulating pathway from a first location where heat absorbing fluid is brought to a cooled state to the fan unit  104  as a second location where the fluid absorbs thermal energy from air moving through the fan unit  104 . The pipes  110  then carry the fluid from the second location back to the first location to give off the thermal energy absorbed from the air moving through the fan unit  104 , thus brining the fluid back to the original cooled state. As a matter of reference the portion of the pipes carrying the cooled state fluid to the fan unit  104  from the first location, pipes  110  and  118 , is referred to as a “supply line”, and the portion of the pipes carrying the fluid that has absorbed thermal energy from the air moved through the fan unit  104  back to the first location, pipes  108  and  120  is referred to as a “return line”. In an alternative arrangement, the return line may deliver the heat adsorbing fluid to a location other than the first location, such the the cooling loop does not function as a recirculating loop (i.e., the fluid leaves the loop after traveling the path through pipes  110 ,  118 ,  120  and  108 ) but is still, in a generic sense, “circulated” through the loop. This is particularly the case when the heat absorbing fluid is water. However, it should be understood throughout the embodiments of the cooling system  100  that the heat absorbing fluid could be any type of fluid having a desired specific heat value, such as water or various refrigerants. 
   According to one embodiment, the supply line (pipes  110  and  118 ) carries the chilled water supply for the facility in which in the system  100  is located, with the return line (pipes  120  and  108 ) carrying the chilled water return for the facility. Water catch trays  112  and  116  are provided to capture the condensation falling from the pipes  108  and  110 . The use of facility chilled water for the primary cooling loop  102  may be alone, or in combination with a chiller system  114 , such as a water-based chiller. In situations where facility chilled water is not supplied, the chiller system  114  may also be a refrigerant-based chiller, where refrigerants such as R-134a and similar compounds are utilized as the heat absorbing fluid of the cooling loop  102 . 
   The fan unit  104  includes a general enclosure  122  serving as a housing for the unit  104 , a fan assembly  124  and one or more intake ports  126  through which ambient air Aa is drawn into the enclosure  122 . The fan assembly  124  pulls the ambient air Aa over the pipe  118  containing the heat absorbing fluid, such that the fluid draws thermal energy from the ambient air Aa to form cooled air Ac. The ducting structure  128  includes one or more continuous ducts which extend from the output of the fan assembly  124  to the back region  24  of each cabinet  10 , to create a flow pathway for the cooled air Ac to one or more entrance openings in the cabinets  10  (i.e., at the back region  24 ). The cabinets  10  preferably reside on a raised support floor  50  of a room of the facility, with the fan unit  104  preferably located between the actual structural floor  51  of the facility and the raised floor  50 . The ducting structure  128  extends through the raised floor  50  to reach the opening in the cabinets  10 . The entrance openings are preferably chosen so as to maximize the flow of cooled air Ac across the electronic equipment  22  to an opposite side of the cabinet  10  to one or more exit openings (i.e., at the front region  26 ), forming an exhaust pathway for the moving air. For instance, as heated air naturally rises through convection, larger entrance opening may be needed at higher levels of the cabinet  10  as opposed to lower levels, to maintain a consistent cooling effect at various heights within the cabinet  10 . Of course, the particular sizes, locations and configurations for the cabinet entrance and exit openings depends on a variety of factors, such as the location and types of electronic equipment  22  housed within the cabinet  10 , the location of other cooling devices within the cabinet  10  or room in which one or more cabinets  10  are located, among other factors. At the same time, it is preferred that the entrance and exit openings are configured to encourage a cooled air Ac flow laterally or horizontally through the cabinets  10  that is, to at least some degree, perpendicular to the natural direction of rising heated air through natural convection. 
   The secondary cooling subsystem  106  is generally positioned to receive the exhaust air flow leaving the exit openings (or open front) of the cabinet  10  at a downstream position, and to remove thermal energy from the air flow. Accordingly, portions of the secondary cooling system  106  may be located immediately outside of the front region  26  of each cabinet  10 , or may be located further away from the cabinets  10  where the exhaust air tends to travel, for instance, generally above the cabinets  10  due to the rising of the heated air through natural convection. The secondary cooling system  106  may take the form of a general heat exchanger with a recirculating refrigerant capturing the thermal energy from the cabinet exhaust air, such that the thermal energy may be utilized for other proposes in the facility (e.g., to create steam, drive an engine, etc.). In one arrangement, the secondary cooling system  106  takes the form of a cold plate, or chilling plate, and cooling loop arrangement. Specifically, a heat exchanger  130  remove thermal energy from a heat absorbing fluid to place the fluid in a cooled state, and them pumps the fluid through cooling loop formed by a set of pipes  132   a ,  132   b ,  132   c , or  132  generically, that circulate the fluid through a set of chilling plates  134   a ,  134   b ,  134   c , or  134  generically. The plate  134 , which are commonly formed of aluminum or other thermally conductive metals, act as heat sinks to absorb thermal energy from the cabinet exhaust air, with the circulating heat absorbing fluid removing the thermal energy from the plates  134 . One suitable material for the pipes  132  is copper, due to the thermal conductivity of the metal and corrosion resistance. One example of a chilling plate  134  and pipe  132  arrangement is illustrated in  FIG. 3 . 
   In one alternative embodiment, the chilling plate  134  of the secondary cooling system  106  are located within one or more of the cabinets  10  (e.g., chilling plate  134   c ), to provide thermal energy dissipation closer to the source of heat generation (i.e., proximal to the electronic equipment  22 ). For instance, a number of chilling plates  134  may be positioned within a particular cabinet  10  at locations where higher relative densities of thermal energy are given off by the equipment  22 , or where it is difficult to maintain an acceptable rate of flow of the cooling air Ac. 
   It should be understood that particular components of the cooling system  100 , such as the fan unit  104 , the secondary cooling system  106  and the chiller system  114 , may be powered by conventional means, such as utility supplied AC electrical power, or by any other power supply devices, such as backup, failsafe power generation systems or other distributed power systems (e.g., fuel cell based systems, and the like). This is especially advantageous at telecommunications facilities, where if a main power supply is lost, but backup power is available to run the telecommunications equipment  22 , then backup power supplies can also maintain power to the cooling system  100  to prevent overheating of the equipment. Furthermore, by utilizing distributed power systems, such as at remote telecommunications sites, the cooling system  100  may be powered without having to connect with a central electrical grid. 
   The various embodiments of the cooling solution of the present invention provide high density cooling that is targeted specifically to the telecommunications or other electronic equipment  22 , reducing or eliminating the need to provide general air conditioning distributed throughout the room or enclosure where the equipment racks or cabinets  10  are located. For instance, if the facility or specific room where the cabinets  10  are located does not house a number of staff, or such persons otherwise spend a limited amount of time within the cabinet housing room, the system  100  eliminates the need to expend energy to cool the entire space of the room. 
   Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the spirit and scope of the present invention. Embodiments of the present invention have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art that do not depart from its scope. A skilled artisan may develoop alternative means of implementing the aforementioned improvements without departing from the scope of the present invention. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated to be within the scope of the claims.