Patent Publication Number: US-2010130117-A1

Title: Method and apparatus for data center air conditioning

Description:
FIELD OF THE INVENTION 
     The present invention relates in general to a method and apparatus for data center cooling. More particularly, the present invention relates to an improved method and apparatus that allows outside air to enter the cooling cycle of the data center to thus reduce mechanical cooling requirements. 
     BACKGROUND OF THE INVENTION 
     Modular data centers are typically an intermodal shipping container that is delivered to a particular site with all computer components and cooling systems installed and ready for hook up at the site to cooling fluids and electrical power. Delivery and removal of containers as well as structural elements of storage on site make the use of currently used economizers impossible. The currently used cooling systems for modular data centers have no airside economizer element. In this regard reference is made to an example found in U.S. Pat. No. 7,278,273 which describes a data center that uses an internal vent system that only teaches the use of inlet and outlet vents that provide only convection flow through the data center shelves. 
     A problem associated with existing economizer structures is the fact that they use opposed blade dampers. These cannot be used with data center structures for the following reasons
         1) free area (the space that air flows through) would require larger openings in the return and outside air openings of the data center structure. There is no way to increase the size of the openings due to the limited space inside for the return damper and for the outside air damper to introduce air to the cooling air flow cycle. The cfm of air required for an economizer cannot be introduced into the cooling air flow cycle using current economizer designs.   2) Weight requires additional support to carry which would also interfere with the interior air cooling spaces in the container.   3) Depth of economizer does not allow arrangement of containers in side by side storage.   4) Depth and weight does not allow for easy installation and removal of economizers on site to meet the needs of portability.       

     Accordingly, it is an object of the present invention to provide an improved cooling technique that is in particular for use in association with an existing data center. 
     Another object of the present invention is to provide a data center cooling apparatus as expressed above and in which an economizer apparatus can be readily attached with an existing data center structure and without requiring any substantial modification to the data center structure. 
     Still another object of the present invention is to provide an airside economizer useable with a data center to allow outside air to enter the existing cooling cycle of the data center to thus reduce internal mechanical cooling requirements. 
     A further object of the present invention is to provide an airside economizer useable with a data center and in which airside economizer modules can be readily installed on site and also readily removed on site to allow intended portability of data center containers. 
     Still a further object of the present invention is to provide an airside economizer useable with a data center and in which the airside economizer modules are of a size (minimum width in particular) that enable them to be readily attached to the data center, and yet are effective in providing the economizer characteristics to the data center structure. 
     SUMMARY OF THE INVENTION 
     To accomplish the foregoing and other objects, features and advantages of the present invention there is provided a data center apparatus for controlling in an efficient manner the cooling cycle of the data center. The apparatus comprises a data center having at least one stack of computer equipment stored therein, and including an enclosing housing. The data center also includes a re-circulation system therein that includes internal means for re-circulating air in a cooling cycle about the computer equipment. In accordance with the invention there is provided one or more economizer structures each attached to at least one side of the data center housing. The economizer structure comprises at least one module that includes means for introducing an auxiliary air flow to supplement the re-circulation of air in the data center. 
     In accordance with other aspects of the present invention the economizer modules enable outside air to be introduced to the modular data center cooling cycle; the economizer modules are provided segmented in length and installed along the exterior of the modular data center housing; the modules are removably attached to the data center housing; including an exhaust channel located within the modular data center for conveying hot air to be exhausted; preferably the economizer module is at the bottom of the data center housing and the exhaust channel extends therefrom to a top of the data center housing where a vent is provided through which exhaust occurs; including a sash damper and a sash damper housing enclosing the sash damper and a spring return sash damper roller; including a filter in the module; including a first damper in the module and a second damper in the return air damper constructed of a material capable of being formed into and unwound from a roll; including a sash damper motor for modulating the damper position between open and closed positions, and the damper is a sash damper; including a sash damper, a guide wire for controlling the sash damper and a connector for connecting the sash damper and guide wire; including damper wheels and a damper wheel track, said connector constructed of metal or plastic and capable of supporting the sash dampers, sash damper wheels and guide wire; wherein there are preferably two guide wires for connecting the sash damper connector and the damper motor; including an exhaust fan for conveying hot air from the exhaust channel to the exterior of the modular data center, and wherein the fan exhaust is to substantially match the amount of outside air introduced via the economizer module; including one or more sash damper rollers having a spring return and rotatable to allow the sash damper to roll out or retract inward; including one or more sash damper wheels attached to the sash damper connector to allow the damper to travel in the sash damper wheel track; wherein the sash damper wheel tracks allow the sash damper wheels to move freely in both directions between open and closed positions; including one or more sash damper stabilizer rods mounted on the top and bottom of the sash damper wheel track for stabilizing the sash damper from movement of air through the sash damper opening; including sash damper seals connected to the wheel tracks to provide a seal on both sides of the sash damper and to prevent moisture migration; and including a digital control system capable of controlling the economizer module in cooperation with a data center environmental control system. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The present invention will now be readily understood and enabled by a consideration of the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a schematic representation of a typical cooling air cycle in a modular data center; 
         FIG. 2  illustrates the cooling air cycle of an airside economizer introducing outside air into a modular data center, as in accordance with the present invention; 
         FIG. 3  schematically shows a side view of the economizer module and components; 
         FIG. 4  shows an airflow schematic with economizer components as in accordance with the present invention; 
         FIG. 5  shows a plan view of a modular data center with exhaust channel and hot air exhaust fans; 
         FIG. 6  shows the sash damper component detail side view; 
         FIG. 7  shows a plan view of the sash damper; 
         FIG. 8  shows the sash damper wheel guide track and sash damper stabilizer rods; 
         FIG. 9  shows the sash damper seals connected to the wheel track on both sides of the sash damper; 
         FIG. 10  shows a front view of the damper connector with wheels; and 
         FIG. 11  shows a modular data center with the economizer modules of the present invention attached thereto. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention is now described in further detail herein by reference to the accompanying drawings. The method and apparatus of the present invention allows the introduction of outside air to the cooling cycle of modular data centers. The apparatus may be in the form of a series of modules that can be readily attached to an existing data center module. These modules preferably are provided in segments to serve preferably the full length of the modular data center. These segments are of a weight that allows easy installation and removal on site. The modules of the present invention preferably have a depth that allows installation with steel structural elements of the modular data center infrastructure. Sash dampers are used to reduce the depth and weight of the economizer module. 
     Typical modular data centers are 40 feet long, and the modules of the present invention can be constructed in five foot segments. This would thus require eight economizer modules for each side of the data center to cover the entire length of the data center. Total economizer module quantity would thus be sixteen total economizer module lengths and quantities will also be based on the modular data center cooling system manufacturer requirements. The use of one or more airside economizer modules enables outside air to be introduced to the modular data center cooling cycle. Airside economizer modules that are segmented in length can be installed along the exterior of the modular data center. The segments are of a sufficient length and quantity to serve the intended purpose of introducing outside air to the modular data center. The economizer modules are intended to be removable and lightweight. 
     Modular data center containers with modular components suitable for use with rack or shelf mount computing systems currently use cooling methods that do not include economizers due to size constraints of structural steel support infrastructure associated with modular data centers. The structure of the present invention allows introduction of outside air to the cooling cycle of the data center with the unique elements thereof embodied within airside economizer components that are described in further detail hereinafter. The present invention represents a new and useful process to allow the economizer elements to bring outside air into the modular data center cooling cycle, and under a controlled manner with the particular use of damper controls. 
       FIG. 1  shows a typical data center that may employ modular components suitable for use with rack or shelf mount computing systems, and including specifically an internal cooling system contained within the modular data center. In  FIG. 1  the computer equipment is indicated at  25 . This may include shelves that house several computers stacked in a column as represented at  25  in  FIG. 1 .  FIG. 1  shows the modular data center cooling airflow with several arrows shown to indicate the air flow through the data center. The air flow is controlled by fans  24  that provide a re-circulation of air as illustrated by the series of arrows shown. Hot air from the equipment  25  is show at  20 . The return hot air is represented by arrows at  18 . The cooled air is indicated at  23 . 
       FIG. 2  shows the cooling airflow through the data center with the addition of the economizer module  1  of the present invention. The economizer also includes the exhaust channels  2  depicted in  FIG. 2 . Some of the same reference characters are used in  FIG. 2  as illustrated previously in  FIG. 1 . Thus arrows  18  indicate hot air return and arrows  23  indicate the cooling air flow. Superimposed in  FIG. 2  are other arrows indicating air flow as represented by the addition of the economizer module  1  of the present invention. The outside air is shown at  22  entering each of the opposite side modules  1 . Further details of the modules  1  are set forth in  FIGS. 3-11 . The computer equipment  25  is shown with the cooling air  23  and the expelled hot air  20 . The input air  22  from the outside is mixed with the hot air return as illustrated at  21 , and drawn by the cooling fans  24 . At the same time  FIG. 2  illustrates the how air to an exhaust at  19 . Thus, there could be considered a dual flow between module  1  and the exhaust at  2  through the channel that intercouples them. 
       FIG. 3  shows a schematic side elevation view of the airside economizer module  1 , air filter  4 , sash damper  5 , sash damper motor  6  and sash damper roller housing  3 , and the outside air at  22 . The air filter  4  may be of conventional type, and the damper motor  6  may also be conventional in design. Further details of the damper arrangement are disclosed in, for example, in  FIGS. 6-10  that are described later. 
       FIG. 4  shows return air sash damper  14 , outside air sash damper  5 , sash damper roller housing  3 , sash damper motor  6 , air filter  4  and economizer module  1  hot air to return  18 , outside air  22 , mixed hot air return and outside air  21 . Thus, in  FIG. 4  there is, in addition to the damper  5  at the module  1 , a channel damper  14  that controls air flow in the data center. Both of these are respectively controlled from corresponding drive motors  6 .  FIG. 5  schematically shows exhaust channels  2 , hot air exhaust fans  9  and modular data center  26 . The channel  2  in  FIG. 5  is essentially depicting the air flow way between the module  1  and the top output port at  2  in  FIG. 2 . In  FIG. 5  the left hand fans  9  may be considered at forcing air into the channel  2 , while the right hand fans  9  may be considered as withdrawing air from the channel  2 . 
       FIG. 6  schematically illustrates the sash damper components. This includes a sash damper roller  10 , sash damper housing  3 , sash damper  5 , sash damper wheels  11 , sash damper connector  7 , motor guide wire  8  and damper motor  6 . The sash damper roller is depicted as positioned in the housing  3 . The damper connector simply couples together the sash damper  5  with the motor guide wire  8 . In that way the motor  6  can control the position of the damper  5  so as to determine how much the damper closes off or opens either the channel  2  or the inlet of air at the module  1 . The sash damper wheels are for positionally guiding the control wire  8  and damper  6 .  FIG. 7  also shows the same sash damper components as disclosed in  FIG. 6 . This includes the roller housing  3 , sash damper  5 , sash damper connector  7  motor guide wire  8  and damper motor  6 . It is noted from  FIG. 7  that the wire  8  is actually separated into two wires connected, through the connector  7 , to opposite ends of the sash damper  5 . 
       FIG. 8  is a further schematic illustration of certain components of the system. This includes sash damper connector  7 , sash damper wheels  11 , sash damper wheel track  12  and sash damper stabilizer rods  13 . The stabilizer rods  13  maintain the tracks  12  in a proper position relative to each other. This arrangement allows the damper to properly slide between open and closed positions thereof. The arrangement shown in  FIG. 8  can be used for both the damper  5 , as well as the damper  14  depicted in  FIG. 4 .  FIG. 9  is still a further schematic view of the damper components taken from an orthogonal view to that shown in  FIG. 7 . This includes sash damper seals  16  attached to the wheel guide track  12  on both sides of the sash damper  5 . The damper seals also form additional guides for the damper, and apply to either damper  5  or damper  14 .  FIG. 10  schematically shows sash damper connector  7  and sash damper wheels  11 . 
       FIG. 11  schematically illustrates a modular data center perspective side view with the economizer modules attached. Economizer modules  1  preferably have a module depth on the order of 6 inches as at  27  in  FIG. 11 . The series of modules are attached to the side of the modular data center  26 . Each of the modules may be of the type previously detailed in the earlier FIGURES. The modules  1  preferably extend at least along a major length of the side of the data center  26 . For a 40 foot length five modules are depicted in  FIG. 11 . In that case each module may be eight feet long. The modules  1  have a length preferably in a range of 4-12 feet depending upon the size of the particular data center. The data center  26  may be considered as comprising an outer housing of metal to which the individual modules  1  are attached in a relatively simple manner. Also they are attached so that they can also be readily removed. In addition to the modules  1 , but not shown in  FIG. 11 , is a top vent structure incorporated into the data center, as depicted in  FIG. 2  at the area above  2 . See also the vent arrangement of  FIG. 5 . In  FIG. 11  the data center  26  is represented by way of example as having dimensions of 40 feet long, 9 feet high and 8 feet wide. Of course, other dimensions may also apply to the data center  26 . 
     The following are some of the features of the present invention. In the invention one or more airside economizer modules are used and enable outside air to be introduced to the modular data center cooling cycle. Airside economizer modules are preferably provided segmented in length and installed along the exterior of the modular data center, particularly a sidewall of the data center, and more particularly along opposed sidewalls The segments are of a sufficient length and quantity to serve the intended purpose of introducing outside air to the modular data center. The modules are intended to be removable and lightweight. Due to space constraints in a typical data center the modules of the present invention are provided with a restricted width, preferably on the order of six inches. This is not possible with existing economizer structures such as an opposed blade damper. However, the sash damper structure of the present invention in particular has been found as effective in providing the economizer characteristics, but with a size and width that enable the economizer structure to be readily attached to sides of the data center housing. The attachment itself can be by conventional means such as well known fasteners. The sash damper arrangement enables the proper re-circulation control yet with a minimum of width between data center housings. 
     In accordance with further features of the present invention one or more exhaust channels located within the modular data center are used convey hot air that is to be exhausted. One or more sash damper roller housings are provided to enclose the sash damper and a spring return sash damper roller. Filters are used to remove pollutants. The sash dampers are provided to control the amount of air allowed through sash damper openings and into the cooling cycle. The sash damper is preferably made of rubber or any material that has the ability to be rolled and unrolled and has sufficient thickness and strength to operate properly. The sash damper motors modulate the sash damper position between open and closed. The sash damper connectors attach to the sash dampers, the sash damper guide wires and the damper wheels. The sash damper connector is preferably made of metal or plastic and capable of supporting the sash dampers, sash damper wheels and guide wire. 
     In accordance with still other features of the present invention the module is provided with exhaust fans that convey hot air from exhaust channels to the exterior of the modular data center. The fan exhaust is meant to match the amount of outside air introduced via the economizer module. A fan can be provided at both ends of the channel or only at the outlet end (top in  FIG. 2 ). 
     The sash damper roller has a spring return and rotates to allow the sash damper to roll out or retract inward. The sash damper wheels are preferably attached to the sash damper connector to allow the damper to travel in the sash damper wheel track. The sash damper wheel tracks allow the sash damper wheels to move freely in both directions between open and closed positions. The sash damper stabilizer rod are preferably mounted on the top and bottom of the sash damper wheel track and stabilize the sash damper from movement of air through the sash damper opening. The air sash dampers ( 5  and  14 ) control the amount of air returned to the cooling cycle. There is also preferably provided digital control systems capable of controlling all elements of the present invention and communicating with modular data center environmental control systems. The sash damper seals connect to the sash damper wheel tracks and provide an air seal on both sides of the sash damper and prevent moisture migration. 
     The following description is presented to enable any person skilled in the art to make and use the invention. Descriptions of specific embodiments and applications are provided only as examples and various modifications will be readily apparent to those skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed herein. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention. One example of a variation is that the modules  1  could be attached at the top of the data center housing rather than at the bottom as depicted in the drawings herein. In that case the venting is from the top of the data center housing. 
     List of Components 
       1 . Economizer module 
       2 . Exhaust channel 
       3 . Sash damper roller housing 
       4 . Air filter 
       5 . Sash damper 
       6 . Sash damper motor 
       7 . Sash damper connector 
       8 . Sash motor guide wire 
       9 . Exhaust fans 
       10 . Sash damper roller 
       11 . Sash damper wheels 
       12 . Sash damper wheel track 
       13 . Sash damper stabilizer rods 
       14 . Return air sash damper 
       15 . Economizer digital control element 
       16 . Sash damper seals 
       17 . not used 
       18 . Hot air to return 
       19 . Hot air to exhaust 
       20 . Hot air 
       21 . Mixed hot air return and outside air 
       22 . Outside air 
       23 . Cooling air 
       24 . Cooling fans 
       25 . Computer equipment 
       26 . Modular data center 
       27 . Module depth which may be 6 inches