Patent Publication Number: US-2015060014-A1

Title: Server rack cooling system

Description:
FIELD 
     Embodiments of the present disclosure relate to cooling technologies, and particularly to, a cooling system used in a server rack having a plurality of servers. 
     BACKGROUND 
     Server racks are widely used to receive a plurality of servers. When the servers of the server racks are working, a great amount of heat may be produced in the server racks. In a typically cooling method for a server rack, a single fan group including one or more cooling fans is shared by one or more servers to cool the servers. 
     However, when the single fan group does not work due to malfunctions, the servers cooled by this group of fans may work unstably due to a high temperature. Therefore, there is room for improvement in the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic rear view of one embodiment of a server rack. 
         FIG. 2  is a schematic top view of one embodiment of the server rack of  FIG. 1 . 
         FIG. 3  is a schematic block diagram of a cooling system used for cooling servers of the server rack of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     The disclosure, including the accompanying drawings, is illustrated by way of example and not by way of limitation. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean “at least one.” 
       FIG. 1  and  FIG. 2  show a server rack  100  configured to receive a plurality of servers  10 . The server rack  100  includes a plurality of main fan groups  20  for cooling the servers  10  of the server rack  100 . Each of the main fan groups  20  includes one or more cooling fans. In this embodiment, each main fan group  20  is arranged corresponding to one or more servers  10  to cool the one or more servers  10 . 
     The server rack  100  further includes a backup fan group  30 . When a main fan group  20  does not work, the backup fan group  30  moves to a location corresponding to the main fan group  20  to replace the main fan group  20  to cool one or more corresponding servers  20 . The backup fan group  30  includes one or more cooling fans. 
     In this embodiment, the server rack  100  further includes a delivery mechanism  200  to carry the backup fan group  30 . The delivery mechanism  200  can drive the backup fan group to move within the server rack  100 .  FIG. 2  shows that the servers  10 , the main fan groups  20 , and the backup fan group  30  are respectively located at different planes. A plane in which the main fan groups  20  resides spaces a predetermined distance from a plane in which the backup fan group  30  resides, so that the backup fan group  30  cannot be blocked by the main fan groups  20  during moving within the server rack  100 . 
     In this embodiment, the delivery mechanism  200  includes a sliding structure  22  and a connecting member  21 . The sliding structure  22  defines a sliding track. The connecting member  21  connects the backup fan group to the sliding structure  22 . A motor  40  is located in the server rack  100  to drive the backup fan group  30  to slide along the sliding track. The motor  40  can be a servo motor. 
     In one embodiment, the sliding structure  22  includes two sliding grooves respectively located at two opposite inner sidewalls of the server rack  100 . Thus, the backup fan group  30  can slide along the sliding grooves under the drive of the motor  40 . In another embodiment, the sliding structure  22  includes two sliding rails respectively located at the two opposite sides of the server rack  100 . Thus, the backup fan group  30  can slide on the sliding rails under the drive of the motor  40 . In this embodiment, the sliding structure  22  and the backup fan group  30  are located in a same plane making the backup fan group stably move in the plane. 
     The server rack  100  further includes a motor controller  50  and fan controller  60 . The motor controller  50  is configured to control the motor  40 . The fan controller  60  is configured to control the main fan groups  20  and the backup fan group  30 . For example, a rotation speed of the cooling fans of the main fan groups  20  and the backup fan group  30  is controlled by the fan controller  60  according to a real-time temperature of corresponding servers  10 . In this embodiment, the main fan groups  20 , the backup fan group  30 , the motor  40 , the motor controller  50 , and the fan controller  60  corporately form a cooling system of the server rack  100 . 
       FIG. 3  shows a schematic block diagram of the cooling system. The fan controller  60  is electrically connected to the motor controller  50 , the backup fan group  30 , and each of the main fan groups  20 . The fan controller  60  monitors a real-time working state of each of the main fan groups  20  to detect whether or not the main fan groups  20  are malfunctioned. When a malfunctioned main fan group  20  is monitored by the fan controller  60 , the fan controller  60  sends a trigger signal to the motor controller  50 . In this embodiment, the trigger signal includes location data indicating a location where the malfunctioned main fan group  2  is located. The fan controller  60  can be a baseboard management controller (BMC) located in the server rack. The BMC (not shown) is used to monitor working states of the plurality of servers  10 . In other embodiments, the fan controller  60  can be a control device (e.g., a processor) of one of the servers  10 . 
     When the motor controller  50  receives the trigger signal from the fan controller  60 , the motor controller  50  controls the motor  40  to drive the backup fan group  30  to move to a location corresponding to the location of the malfunctioned main fan group  20  via the delivery mechanism  200 . Thus, the backup fan group  30  replaces the malfunctioned main fan group to cool one or more servers  10 , which are previously cooled by the malfunctioned main fan group  20 . 
     In this embodiment, the motor controller  50  first calculates a distance that the backup fan group  30  needs to be moved according to the trigger signal, and then sends a control command according to the calculated distance to the motor  40  to drive the backup fan group  30  to move the calculated distance via the delivery mechanism  200 . In one embodiment, a distance between the location of the backup fan group  30  and the location of each of the main fan groups  20  is prestored in the motor controller  50 . Thus, the motor controller  50  can directly obtain the distance that the backup fan group  30  needs to be moved according to the location of the malfunctioned main fan group  20 . 
     When the backup fan group  30  is moved to the location corresponding to the malfunctioned main fan group  20 , the fan controller  60  controls the backup fan group  30  to start working and outputs a warning message to warn a user that one of the main fan groups  20  is malfunctioned. In one embodiment, the warning message may be an audible output from a buzzer of the fan controller. In other embodiments, the warning message can be a text message sent to a device (e.g., a smart phone or a personal computer) of the user via one of the servers  10 . 
     When the fan controller  60  detects that the malfunction of the malfunctioned main fan group  20  is eliminated (e.g., the malfunctioned main fan group  20  starts to work again), the fan controller  60  controls the backup fan group  30  to stop working Then, the fan controller  60  outputs a comeback signal to the motor controller  50 . The motor controller  50  controls the motor  40  to drive the backup fan group  30  to return to an original location via the delivery mechanism  200 . The original location can be pre-stored in the motor controller  50 . 
     It will be understood that the backup fan group  30  can be manually moved via the delivery mechanism  200 . That is, some elements of the cooling system such as the motor  40 , the motor controller  50 , and the fan controller  60  can be omitted in some embodiments. 
     As described above, when one or the main fan groups  20  is malfunctioned, the backup fan group  30  can be used to replace the malfunctioned main fan group  20  to cool corresponding servers  20 . Thus, the stability of the servers is improved. 
     Although certain embodiments of the present disclosure have been specifically described, the present disclosure is not to be construed as being limited thereto. Various changes or modifications may be made to the present disclosure without departing from the scope and spirit of the present disclosure.