Abstract:
An apparatus and method is provided for conveying heat away from an electronic component. In one embodiment, an adjustable vane is positioned so that air in a channel is diverted from a first cooling zone to a second cooling zone by the adjustable vane to another part of the chassis using a control mechanism. The apparatus can be controlled in a way that regulates temperature of an electronic component by adjusting airflow within the chassis.

Description:
TECHNICAL FIELD 
       [0001]    Embodiments described herein generally relate to cooling, and more specifically, to cooling of electronic components in a chassis. 
       BACKGROUND 
       [0002]    Heat generated by electronic devices degrades many electronic devices within a chassis. These electronic devices need to be cooled in order to work effectively. In order to cool electronic devices, fresh, unheated air needs to be circulated over the components. The current dense placement of electronic devices and cooling devices in crowded electronic arrangements is a factor in providing for appropriate cooling within the chassis. 
       SUMMARY 
       [0003]    In an embodiment, a chassis is designed in an open configuration to include a first cooling zone, a second cooling zone, and a bypass zone. The chassis includes adjustable vanes and adjustable fans that are attached to the chassis and respond to parameters to provide for modified cooling flow in the second zone through use of the bypass zone. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    Embodiments are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements or steps: 
           [0005]      FIG. 1  shows a schematic representation of a retracted cooling system from the top view according to various embodiments. 
           [0006]      FIG. 2  shows a schematic representation of an extended cooling system from the top view according to various embodiments. 
       
    
    
     DETAILED DESCRIPTION 
       [0007]    Heat may be removed from an electronic device and its immediate area in order for the device to maintain an operational temperature within desired limits. Failure to remove heat effectively results in increased device temperatures, which in turn, may lead to thermal runaway conditions causing decreased performance and potentially catastrophic failure. Thermal management is the process of maintaining a desirable temperature in electronic devices and their surroundings. As more devices are packed into a chassis, heat flux (Watts/cm2) increases, resulting in the need to more aggressively remove heat from a given electronic device. A common trend in the industry is to cool electronic devices using circulated air. However, cooling electronic devices in a crowded multi-electronic device environment may result in downstream warm air that may cool another electronic device. Noise limitations may prevent adding more fans downstream. Furthermore, fan reliability may be compromised by higher fan intake air temperature. Compounding the problem is that electronic devices require different cooling requirements with low power areas producing a lower heat flux and high power areas intermittently producing a higher heat flux. Due to space limitations from smaller form factors, separate ducts of air may also not be feasible. The need to cool current and future high heat load, variable heat flux electronic devices and systems therefore mandates the development of alternate cooling methods. An aspect of the current disclosure may be lower noise levels and a smaller form factor for modern electronic devices. 
         [0008]    Features illustrated in the drawings are not necessarily drawn to scale. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments of the current disclosure. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments may be practiced and to further enable those of skill in the art to practice the current disclosure. It is also to be understood that the descriptions of the embodiments are provided by way of example only, and are not intended to limit the scope of this current disclosure as claimed. 
         [0009]    Shown in  FIG. 1  is a chassis  110  in a ductless configuration according to an aspect of the current disclosure. 
         [0010]    The chassis  110  has a front face  114 , two sides  116 , a rear face  118 , a top  120 , and a bottom  122 . The chassis  110  may be of sufficient size to fit into a 19-inch server rack. The chassis  110  may be made of materials to facilitate cooling such as copper, sheet metal, plastic, or wood. In the embodiment shown, the rear face  118  and front face  114  may be made of perforated sheet metal and the sides  116 , top  120 , and bottom  122  may be made of solid sheet metal. 
         [0011]    There is at least one fan  124  which may be located generally near and parallel to the rear face  118 . The fan  124  may be attached external to the rear face  118 , but the fan  124  may be attached internal to the rear face  118  or mounted in another appropriate fashion. The fan  124  may be oriented so that air flows into the chassis  110 . The fans  124  may be counter rotating in pairs. In  FIG. 1 , two fans  124  may be counter-rotating. 
         [0012]    The chassis  110  contains at least one circuit board  126  attached to the bottom  122 , but other configurations are contemplated. In  FIG. 1 , for example, fiber optic ports  128  are attached to the bottom  122  and two power supplies  130  may be located along the side  116  within the chassis  110 , but other configurations are contemplated. 
         [0013]    The chassis  110  contains a first cooling zone  132  and a second cooling zone  134 . In the first cooling zone  132 , there is at least one first electronic component  136 . The first electronic component  136  may be comprised of memory units or other generally consistent heat flux devices. In the shown embodiment, for purposes of illustration and not limitation, there are seven memory units  136  attached to the circuit board  126  arranged generally perpendicularly to the rear face  118  and perpendicularly to the bottom  122 . The memory units  136  may be parallel to other memory units  136  with adequate spacing between each memory unit  136 , but other configurations are contemplated. In the shown embodiment, the memory units  136  may be dual in-line memory modules (DIMMs), single in-line memory modules (SIMMs), hard drives, Solid State Drives (SSDs), or other consistent heat flux devices and may be used with heat sinks. 
         [0014]    In the second cooling zone, there may be at least one second electronic component  138 . The second electronic component  138  may be comprised of processors or other generally variable heat flux electronic devices. The second electronic component  138  is, for purposes of illustration and not limitation, comprised of four processors arranged in a linear fashion, mounted on the circuit board  126 , and generally parallel with the front face  114 , with adequate spacing between each processor  138 . In the shown embodiment, the processors  138  may be CPUs but the processors can also be GPUs or wireless transmitters or similar electronic components. 
         [0015]    Vanes  140  may be provided to redirect the airflow within the chassis. The chassis may contain at least one vane motor  142  and at least one vane  140 . A vane is any device that redirects airflow, such as baffles, louvers, dampers, or any other similar device. In the embodiment of  FIG. 1 , two vane motors  142  are, for purposes of illustration, shown as not activated, and the two vanes  140  are retracted into slots  144  so that airflow is not impeded or redirected, but other embodiments that do not impede airflow are permitted For example, other embodiments may include vanes in flush alignment with the chassis parallel to the airflow or retracted into the power supply. The vane motor  142  may be an actuator, a stepper motor, a spring mechanism, or other similar mechanisms suitable for actuating the vane mechanism. 
         [0016]    The vanes  140  may be made of any material that allows for deflection of the airflow such as plastic, fiberglass, glass, sheet metal, carbon fiber, or perforated metal. In the shown embodiment, the vanes  140  are made of sheet metal. The vanes  140  are of a sufficient height and length to deflect airflow. In the present embodiment, the vanes are 5U in height, a unit known in the art, and shorter than the distance from the base of the vane  140  to the processor. 
         [0017]    The vane motor  142  and vanes  140  may be positioned in order to route air. In the shown embodiment, the vanes  140  are attached to the power supply  130  perpendicularly to the airflow and perpendicular to the bottom  122 , but other angles and locations that maximize airflow may be permitted. The vane motor  142  and vanes  140  may be attached with a number of attachment techniques, including, for example, but not limited to adhesive or welding. 
         [0018]    To cool the electronic components in the chassis, air may move into the chassis  110  to create an airflow. In the shown embodiment, the airflow is created by the fan  124 , but the airflow may be created by an external cooling device such as a building HVAC system or a room fan. Within the chassis  110 , the airflow may be separated into separate airflows, such as for example, a low velocity airflow  148  and a high velocity airflow  150 . Low velocity  148  and high velocity airflow  150  are relative to each other. The low velocity airflow  148  may be impeded by the first electronic device  136 , thus slowing the airflow relative to the high velocity airflow  150 , which may have a travel path with little impedance. 
         [0019]    The low velocity airflow  148  may pass through the circuit board  126 . While the low velocity airflow  148  passes through the circuit board  126 , heat from the first cooling zone may be removed. In the shown embodiment, the low velocity airflow  148  flows parallel to the memory units  136 . The low velocity airflow  148  may be warmed by heat from the first cooling zone  132  before passing through the second cooling zone  134 . After passing through the second cooling zone  134 , the airflow may be heated further  152  and may exit the chassis  110  through the front face. 
         [0020]    The high velocity airflow  150  moves at a higher speed along the side of the chassis  110  with minimal heat flux transfer. The high velocity airflow  150  may form the bypass zone  152 , which is the area between the side  116  and the circuit board  126 . The high velocity airflow  150  may pass over the vane  140  and power supply  130  with minimal air impedance and may exit out of the front face of the chassis  114 . 
         [0021]    The chassis may contain at least one sensor  154 . The sensor  154  may monitor a parameter. The parameter may be a temperature indication or other indication sufficient to determine the need for further cooling in the second cooling zone  134 . The parameter may also be ambient temperature, airflow, airflow temperature, processor  138  temperature, processor  138  clock speed, processor  138  current draw, or processor  138  voltage. The shown embodiment has two sensors, one sensor  154  on the processor  138  to monitor processor clock speed and another sensor  154  on the memory unit  136  to monitor airflow temperature. The sensors  154  may be mounted on multiple locations in the area of the chassis  110  sufficient to generate cooling data. The sensor  154  may transmit data on the parameter to the control mechanism  156 . 
         [0022]    The chassis may contain at least one control mechanism  156 . The control mechanism may make adjustments to the airflow based on parameter data from the sensors. The control mechanism may further adjust the vanes  140  or the fan  134 . The control mechanism  126  may be mounted in any location on the chassis. In the shown embodiment, one control mechanism  156  is mounted on the circuit board  126  but other configurations are contemplated. 
         [0023]    In the shown embodiment, the processor  138  may be in a low power state. The sensor may transmit the lower temperature data to the control mechanism  156 , and the control mechanism  156  may compare the processor clock speed to a predetermined higher threshold to determine if more airflow is needed. In the shown embodiment, the processor  138  clock speed is lower than the predetermined higher threshold and there is no action by the control mechanism  156  and the vane  140  may remain in a retracted configuration. In the retracted vane  140  configuration, the airflow  150  may bypass the second cooling zone  134 . This may be necessary when the processor  138  is under low computational strain because lower computations from the processor  138  result in lower heat output. Therefore, the fan noise will not increase beyond, for example, 7.1 bels, which is a Declared A-Weighted Sound Power Level known by those with skill in the art. In other embodiments, other appropriate noise limits may be set with respect to controlling fan noise during cooling operation. 
         [0024]    The extended vane  210  is shown in  FIG. 2 , which depicts a top view of the same chassis  110  in  FIG. 1 . The control mechanism  156  may extend the vane  210  and increase fan  124  output in response to a higher parameter reading from the sensor  154 . When the temperature indication, or other parameter, from the sensor  154  is above a particular parameter threshold, the control mechanism may, in any combination, activate the vane motor  142  to extend the vane  210  in order to redirect airflow to the second cooling zone  134  and increase fan  124  output to increase airflow. In the shown embodiment, the extended vane  210  may be triggered when the sensor  154  transmits processor  138  clock data to the control mechanism  156  and the control mechanism  156  compares a processor clock speed that is higher than the predetermined high threshold. As a response, the control mechanism  156  may control the position of the vane  140  through a vane motor  142  and the fan  124  output by RPM or blade pitch. 
         [0025]    The control mechanism  156  may also, in any combination, reverse the vane motor  142  to retract the vane  210  and decrease fan  124  output. The control mechanism  156  may go back to the retracted position  140  in  FIG. 1  in response to a lower parameter reading. For example, the sensor  154  may transmit clock data to the control mechanism  156  and the control mechanism  156  may compare a processor clock speed that is lower than the predetermined low threshold and decide that enough cooling to the second cooling zone  134  has occurred. The control mechanism  156  may retract vanes  215  and decrease fan  124  output. 
         [0026]    In the extended vane configuration  210 , the vane motor  142  activates and extends the vane  210 . The extended vane  210  may have sufficient height and length to route air from the bypass zone  152  to the second cooling zone  134 . The extended vane  210  may also have sufficient stiffness and locking capability such that the extended vane does not move in response to airflow  212 . 
         [0027]    The extended vane may reroute the bypassed airflow  212  towards the second cooling zone  134  and may form a routed airflow  214 . This routed airflow  214  is pushed forward by the high resistance airflow  148  and absorbs heat from the second cooling zone  134  and vents airflow  216  outside of the chassis. In the shown embodiment, the airflow  216  is vented through the front but other configurations are contemplated such as through the side or top. 
         [0028]    While the disclosed subject matter has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments of the subject matter, which are apparent to persons skilled in the art to which the disclosed subject matter pertains are deemed to lie within the scope and spirit of the disclosed subject matter.