Abstract:
A heat exchange system for exchanging heat with an object may include a centrifugal blower for directing air flow in a downward and an outward direction, a heat sink base positioned to receive the air flow from the centrifugal blower, a diffuser on the heat sink base and in the path of the air flow from the centrifugal blower, the diffuser having vanes that are in thermal communication with the heat sink base that direct the air flow from the blower outward over the heat sink base, and a thermoelectric device having a low temperature side and a high temperature side, where the thermoelectric device is in thermal communication with the heat sink base on the low temperature side and the high temperature side.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present disclosure relates to a thermoelectric-based heat pump, and more particularly, to configurations for thermoelectric-based heat pumps. 
         [0002]    Because of the increased power consumption of electronic technologies, heat rejection systems have grown in size, weight, complexity and cost. In some instances, conventional air-cooled heat sinks have become inadequate. This has resulted in systems with exotic liquid-cooled manifolds, spray-cooled enclosures, and vapor-compression refrigeration being proposed. These approaches may add complexity associated with operation and maintenance of active pumps and compressors, and introduce opportunities for fluid or vapor leakage. Conventional designs may include high heat transfer impingement rows generated by axial fans placed above the heat sink. Small-scale (under 100 W) cooling systems often rely on vapor compression cycles or forced convection of unconditioned air. These types of systems may be limited in application due to their effective range of ambient conditions and/or bulky weight and size. 
       SUMMARY OF THE INVENTION 
       [0003]    According to one embodiment, a heat exchange system for exchanging heat with an object may include a centrifugal blower for directing air flow in a downward and an outward direction, a heat sink base positioned to receive the air flow from the centrifugal blower, a diffuser on the heat sink base and in the path of the air flow from the centrifugal blower, the diffuser having vanes that are in thermal communication with the heat sink base that direct the air flow from the blower outward over the heat sink base, and a thermoelectric device having a low temperature side and a high temperature side, where the thermoelectric device is in thermal communication with the heat sink base on the low temperature side and the high temperature side. 
         [0004]    According to another embodiment, a method for exchanging heat with an object may include directing an air flow through a first centrifugal blower in a downward and an outward direction, directing the air flow from the first centrifugal blower outward over a first heat sink base via a first diffuser on the heat sink base and in a path of the air flow from the blower, the diffuser having vanes that are in thermal communication with the heat sink base, receiving heat from the air flow via the first heat sink base, and exchanging heat with the object via a thermoelectric device having a low temperature side and a high temperature side, where the thermoelectric device is in thermal communication with the heat sink base. 
         [0005]    Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein. For a better understanding of the disclosure with the advantages and the features, refer to the description and to the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
           [0007]      FIG. 1  depicts a perspective view of a compact heat sink with integrated blower; 
           [0008]      FIG. 2  depicts a partial cutaway of the device depicted in  FIG. 1 ; 
           [0009]      FIG. 3  depicts a thermoelectric-based heat exchanger; 
           [0010]      FIG. 4  depicts a chilled air thermoelectric cooling unit; 
           [0011]      FIG. 5  depicts a chilled air thermoelectric cooling unit with thermal storage; and 
           [0012]      FIG. 6  depicts a chilled liquid thermoelectric cooling unit. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0013]    Air cooling system  10  for cooling component C is shown in  FIG. 1 . System  10  may include motor  11 , blower  13 , cover  14 , diffuser  15  and heat sink base  17 . The heat sink base  17  may be an integral part of system  10 , or it may be part of component C being cooled. In  FIG. 1 , the diffuser  15  can also function with heat sink base  17  as part of a heat sink. The motor  11  and blower  13  can be integral and may be mounted on cover  14 , which may serve as the top of the diffuser  15  and supports all of the elements between cover  14  and heat sink base  17 . System  10  can heat and/or cool objects it is in thermal communication with another device, such as a device shown generically as component C. Any object generating heat can be cooled by system  10  if it can be placed in thermal communication therewith. Similarly, in some embodiments, system  10  may transfer heat from system  10  to heat component C. 
         [0014]    Motor  11  is depicted as a toroidal electric motor having a central airway  12  around its rotational axis. Air can be drawn by rotation of blower  13  axially down through central airway  12  into blower  13  and then into diffuser  15 . Air may flow outward or inward with respect to blower  13 . Other motors may also be used, with different configurations and sources of power, and/or similar configurations and sources of power. Controller  21  can provide a source of energy via line  22  to drive motor  11  and other active components described below. In operation, motor  11  may cause air to be drawn into central airway  12  by blower  13 , passing through a central aperture in cover  14  into diffuser  15 . The air can flow through diffuser  15  and contact heat sink base  17  to cool component C. Airflow through diffuser  15  can be radial, spiral or diffuser  15  can be configured for other paths. 
         [0015]    As seen in  FIG. 2 , the internal components of system  10  are shown. Motor  11  can include a housing  11   a , bearings  18 , permanent magnet rotor  19 , stator  20 , and stator windings  20   a  to support rotation of the rotor  19  and blower  13 . Stator windings  20   a  may be positioned to receive electrical power from controller  21  and drive the blower  13  in a normal electric motor fashion. 
         [0016]    Blower  13  may have an upper hub  13   a , a lower hub  13   b  and blades  16 . Upper hub  13   a  can be connected to the permanent magnet rotor  19 . Blades  16  may have an upper end  16   a  connected to lower hub  13   b . A center port  130  in lower hub  13   b  may provide a passage for air flow through lower hub  13   b  and into space between lower hub  13   b  and heat sink base  17 . 
         [0017]    Diffuser  15  may include a plurality of fins or vanes  23  and other elements shown and described below that take air from central passage  12  so that air contacts the vanes  23  and the heat sink base  17  to absorb heat into the air and out of system  10 . Diffuser  15  may serve two purposes in this device. First, diffuser  15  may detect the flow of air from a vertically downward direction radially outward as will be described below. Second, the diffuser vanes  23  may provide additional heat conductive material as part of the heat sink  17 , so that more hot metal is exposed to the cooling air flow. Motor  11 , blower  13 , diffuser  15  and heat sink  17  can attached together to form a single device that can be attached to an electronic package such as a circuit board in the same manner that conventional air-cooled heat-exchangers may be attached. 
         [0018]    It may be advantageous to provide devices for enabling lightweight and compact heat exchange having an optimized rate of heat exchange while providing fewer mechanical parts and operative fluids that may break, leak, etc. As depicted in  FIG. 3 , according to some embodiments, a thermoelectric heat exchange unit  30  may be configured to cool a device or surface in contact with a thermoelectric module  32 . Thermoelectric module  32  may be sandwiched between the device or surface being cooled and a compact air cooling system  31 . Heat exchanger  31  may be substantially similar to air cooling system  10 , but with fins (diffuser vanes)  34  and motor configuration tailored for the specific application. Heat removed from the device being cooled and waste heat produced by the device is rejected to input air  35  within air cooling system  31  and exhausted to the surroundings via hot exhaust port  37 . In some aspects, thermoelectric heat exchange unit  30  may be optimized to maximize heat transfer between component input air  35  and thermoelectric module  32 . 
         [0019]    Referring now to  FIG. 4 , in some embodiments, a chilled air thermoelectric heat exchange unit ( 40 ) may include two air cooling units  31  to generate a chilled air stream. In this configuration, a thermoelectric module  32  may be configured between the two air cooling units  31  Air may be drawn into each air cooling unit and heat can be pumped from one air stream to the other using the thermoelectric module, producing a chilled air stream and a heated air stream. The side of the device with the cooled air stream and the side of the device having the heated air stream can be configured based on the polarity of the voltage applied to the thermoelectric module. The chilled and/or heated exhaust air may be collected in a volute as shown. The volute may comprise a plurality of configurations, including a single exhaust port, or multiple exhaust ports. 
         [0020]    According to some embodiments, hot-side blower  42  and cold-side blower  43  may rotate at the same speed. In other embodiments, the hot-side blower  42  may blow may rotate at a different speed than cold-side blower  43 . In some aspects, each of the blowers  42  and  43  may be either constant or variable speed. 
         [0021]    In other embodiments, a volute (not shown) may be configured with thermoelectric heat pump unit  40  to capture chilled air  44 . The volute may comprise a plurality of configurations, including a single exhaust port, or multiple exhaust ports as needed for air distribution 
         [0022]    In some embodiments, a heat spreader (not shown) may be incorporated between thermoelectric module  32  and the air cooling units  31  to improve thermal performance or allow the thermoelectric module  32  to have a surface area than the air cooling units  31 . 
         [0023]    In some embodiments, the inlet air into each side of the device may come from the same source. In other embodiments, the inlet air may come from different sources. 
         [0024]    In some embodiments, chilled air devices may operate in a low power consumption mode, where heat load may be managed by forced convection of unconditioned air. Accordingly, thermoelectric module  32  and the hot-side heat exchanger may be unpowered while air is circulated to the system being cold using the source side device. 
         [0025]    Referring now to  FIG. 5 , a chilled air thermoelectric heat exchange unit with thermal storage  50  is depicted, in accordance with some embodiments. In this configuration, heat can be pumped from the air stream entering air cooling system  31  to a heat sink  52  using a thermoelectric module  32 , producing a chilled air stream  51  that can be collected in a volute (not shown) with one or more outlet ports. The heat removed from the air stream and waste heat produced by the thermoelectric module is rejected via the heat sink  52  to a phase change material. This heat may be ultimately rejected to ambient via heat sink  52 . In some aspects, this configuration may supply cooling for short periods without requiring significant heat rejection to the surroundings and can accommodate temporary increases in heat load without requiring the system to be oversized for peak cooling loads. Chilled air thermoelectric heat exchange unit  50  may also operate in an open system or a closed system. 
         [0026]    Referring now to  FIG. 6 , a chilled liquid thermoelectric heat exchange unit  60  is depicted according to some embodiments. Heat exchange unit  60  may include a cold plate  61  attached to the thermoelectric heat exchanger  30 . Heat is pumped from the liquid in cold plate  61  to the air cooling system  31  using a thermoelectric module  32 , producing a cooled liquid stream. In other embodiments, the polarity of the voltage applied to the thermoelectric device may be reversed in order to produce a warm liquid stream. 
         [0027]    The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one more other features, integers, steps, operations, element components, and/or groups thereof. 
         [0028]    While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. 
         [0029]    Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.