Abstract:
The present invention relates to a thermoelectric cooler, and more particularly, to a thermoelectric cooler, in which a thermoelectric module is applied to a blow system of a fan blade set and a motor, for converting a current blow system into a blow system having a cooling function with a low noise.  
     To do this, the present invention provides a thermoelectric cooler including a thermoelectric module having thermoelectric elements each for absorbing or dissipating a heat at a junction of two different metal depending on a direction of a current flowing through the junction, a fan blade set for blowing air cooled at a heat absorption side of the thermoelectric module to a desired place, and a motor for giving a rotating force to the fan blade set.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a thermoelectric cooler, and more particularly, to a thermoelectric cooler, in which a thermoelectric module is applied to a current blow system of a fan, for converting a simple blow system into a blow system having a low noise cooling function.  
           [0003]    2. Background of the Related Art  
           [0004]    In general, the blow system is provided with a motor for generating a driving force, and a fan for being rotated by the motor to blow air forcibly, of which typical example is an electrical fan.  
           [0005]    A related art electrical fan will be explained with reference to FIG. 1. FIG. 1 illustrates a related art electrical stand type fan, provided with a motor  21  in an upper part of a body, and fan blade set  22  shaft coupled to the motor  21  in front thereof. When the fan blade set  22  are rotated, the related art electrical fan cools down a temperature of an object as the air accelerates heat exchange between a surface of the object and the air by convection when the air forcibly flows from rear of the fan blade set  22  to front of the electrical fan  2 .  
           [0006]    However, the electrical fan  2  can not cool down a temperature of room air. That is, in general, because the electrical fan merely circulates the room air forcibly, a user feels no coolness if the room temperature is similar to a body temperature. Contrary to this, as the fan blade set  22  are fixed to a motor  21  shaft, the electrical fan  2  becomes to blow warm air when the electrical fan  2  is used for a long time, since a heat of the motor  21  heated from prolonged use is rejected to a front part of the electrical fan  2  through the fan blade set  22 .  
           [0007]    In the meantime, general air conditioners used in home for dropping a room temperature are mostly of a separated, vapor compression type in which the air conditioner is separated into an indoor unit and an outdoor unit. In a case of such a air conditioner in which room air is cooled down by using a phase change of refrigerant, though a cooling capability is excellent, there are following problems.  
           [0008]    Re-positioning of once installed indoor unit and outdoor unit of the air conditioner is difficult, and there are spatial limitations in selection of an installation position of the air conditioner.  
           [0009]    The air conditioner produces a loud noise, and has a poor durability to cause refrigerant leakage, or disorder in a driving part, a great power consumption to give a heavy burden to consumers, and expensive.  
         SUMMARY OF THE INVENTION  
         [0010]    Accordingly, the present invention is directed to a thermoelectric cooler that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.  
           [0011]    An object of the present invention is to provide a thermoelectric cooler, in which a thermoelectric module of the Peltier effect is applied to current electric fan to provide a cooling function to a simple electric fan, for providing a cooler which has a low cost compared to an air conditioner, low noise and low power consumption caused by a driving part, and a long lifetime, and permits easy re-positioning.  
           [0012]    Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.  
           [0013]    To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the thermoelectric cooler includes a thermoelectric module having thermoelectric elements each for absorbing or dissipating a heat at a junction of two different metal depending on a direction of a current flowing through the junction, a fan blade set for blowing air cooled at a heat absorption side of the thermoelectric module to a desired place, and a motor for giving a rotating force to the fan blade set.  
           [0014]    An area of the planar thermoelectric module may vary with a required cooling capacity, and preferably at least larger than an area of the fan blade set.  
           [0015]    The thermoelectric module is planar, preferably, in a circular or rectangular form.  
           [0016]    The circular, or rectangular thermoelectric module may have a variety of sections, such as a straight line, bent form, or arc form.  
           [0017]    The thermoelectric cooler may further has fins fitted to surfaces of the heat absorption side or a heat dissipation side of the thermoelectric module for increasing a heat transfer area.  
           [0018]    The heat dissipation side of the thermoelectric module has a heat pipe or thermosiphon fitted thereto for rejection of heat to an outside of the room.  
           [0019]    According to the present invention, when the thermoelectric module is employed in a current electric fan, the current electric fan can also serve as a cooler.  
           [0020]    According to the present invention, when the heat dissipated at the heat dissipation side of the thermoelectric module is rejected to an outside of the room by using the heat pipe or the thermosiphon, a cooling efficiency is enhanced.  
           [0021]    Because the heat pipe or the thermosiphon is employed for enhancing a cooling efficiency of the thermoelectric cooler of the present invention, a noise caused by a driving part and an increased power consumption are prevented.  
           [0022]    As the thermoelectric cooler of the present invention is fabricated by applying a thermoelectric module to an electric fan that is not expensive, a fabrication cost is saved, fabrication and installation are easy, and purchasing cost is low.  
           [0023]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention:  
         [0025]    In the drawings:  
         [0026]    [0026]FIG. 1 illustrates a perspective view of an electrical fan, one of related art blow apparatuses;  
         [0027]    [0027]FIG. 2 illustrates a section a thermoelectric device in a thermoelectric module of a thermoelectric cooler of the present invention;  
         [0028]    [0028]FIG. 3 illustrates a side view of a thermoelectric cooler in accordance with a first preferred embodiment of the present invention;  
         [0029]    [0029]FIG. 4 illustrates a side view of a thermoelectric cooler in accordance with a second preferred embodiment of the present invention;  
         [0030]    [0030]FIG. 5 illustrates a longitudinal section of the heat pipe in FIG. 4;  
         [0031]    FIGS.  6 A- 6 C illustrates perspective views of exemplary thermoelectric modules employed in the thermoelectric cooler of the present invention;  
         [0032]    [0032]FIG. 7 illustrates a side view of a thermoelectric cooler in accordance with a third preferred embodiment of the present invention;  
         [0033]    [0033]FIG. 8 illustrates a section of a thermosiphon evaporator in FIG. 7; and,  
         [0034]    [0034]FIG. 9 illustrates a perspective view of the thermosiphon evaporator in FIG. 8. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0035]    Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings FIGS.  2 - 9 . The thermoelectric cooler of the present invention includes thermoelectric elements connected in parallel, each of which causes a temperature difference between two ends thereof from an electromotive force to cause the Peltier effect.  
         [0036]    A system and work of a thermoelectric element employed in the thermoelectric cooler  100  of the present invention will be explained with reference to FIG. 2. FIG. 2 illustrates a section a thermoelectric device in a thermoelectric module of a thermoelectric cooler of the present invention, wherein the thermoelectric device includes thermoelectric elements  13  of semiconductor doped with N type impurity ions or P type impurity ions connected in parallel, electrodes  11  and  14  of copper or the like respectively connected to an upper side and a lower side of the thermoelectric elements  13 , and a ceramic substrate  12  or the like enclosing the electrodes  11  and  14 .  
         [0037]    Upon application of a current (DC) to a junction part, the thermoelectric device is involved in the Peltier effect in which the upper part is cooled and the lower part is heated as electrons in the case of the N type semiconductor, or holes in the case of the P type semiconductor, take heat from the upper part and discharges the heat to the lower part. That is, in the Peltier effect, one of electric phenomenon, when a current flows through a junction part of two different metals, a heat is either dissipated or absorbed at the junction part. Therefore, upon application of the current to the thermoelectric device, one side of the thermoelectric device becomes a heat absorption side with a low temperature, and the other side of the thermoelectric device becomes a heat dissipation side with a high temperature, and, if a direction of the current is reversed, the heat absorption side and the heat dissipation side are reversed.  
         [0038]    A basic system of the thermoelectric cooler of the present invention having the thermoelectric module  1  of the thermoelectric elements, which cause the Peltier effect, employed therein will be explained.  
         [0039]    The thermoelectric cooler  100  of the present invention includes a thermoelectric module  1  having thermoelectric elements each for absorbing or dissipating a heat at a junction part depending on a direction of a current flowing through the junction part of two different metals, fan blade set  22  for directing air cooled at a heat absorption side of the thermoelectric module  1  to a desired place, and a motor  21  for providing a rotation force to the fan blade set  22 . Of the junction part of the thermoelectric module  1 , a side close to the fan blade set  22  forms the heat absorption side, and a side far from the fan blade set  22  forms the heat dissipation side.  
         [0040]    The thermoelectric module  1  is formed flat, and more specifically, in a disk or rectangular form. Moreover, in order to form a smooth air flow toward the motor shaft coupled to the fan blade set  22 , the thermoelectric module  1  may have a variety of forms, such as an arc form which is designed to have the smaller radius of curvature as it goes nearer to a front side of the electrical fan, or a bent form which has a bent at a middle part. The thermoelectric module  1  may have an area varied with a required cooling capacity, but preferably at least larger than an area of the fan blade set  22 .  
         [0041]    A thermoelectric cooler in accordance with a first preferred embodiment of the present invention will be explained in more detail. FIG. 3 illustrates a side view of a thermoelectric cooler in accordance with a first preferred embodiment of the present invention, and FIGS.  6 A- 6 C illustrates perspective views of exemplary thermoelectric modules employed in the thermoelectric cooler of the present invention.  
         [0042]    Referring to FIG. 3, the thermoelectric module  1  in accordance with a first preferred embodiment of the present invention is fitted to an outer circumference of the motor  21  in rear of the fan blade set  22  of the electric fan  2 , and has a surface facing the fan blade set  22  serving as a heat absorption side, and a surface opposite to the fan blade set  22  serving as a heat dissipation side, when a power is applied to the thermoelectric module  1 .  
         [0043]    The air drawn from rear of the fan blade set  22  as the fan blade set  22  rotates heat exchanges with the heat absorption side of the thermoelectric module  1 , is cooled down, and flows in a front direction of the electric fan  2 . That is, the air drawn from rear of the fan blade set  22  of the electric fan is blown forcibly in a front direction of the electric fan in a cooled down state, to give a cool feeling to a user in front of the electric fan.  
         [0044]    In the meantime, a variety of forms of heat dissipation means may be provided to the heat absorption side and the heat dissipation side of the first embodiment thermoelectric module  1  for improving a heat exchange efficiency. As one of specific examples, surfaces of the heat absorption side and the heat dissipation side may be designed to have a form that enhances heat exchange, or heat dissipation fins  30  may be fitted to the surfaces of the heat absorption side and the heat dissipation side. In addition to this, a small fan  40  coupled to the motor  21  of the electric fan  2  may be fitted to the heat dissipation side of the thermoelectric module  1 , when the heat on the heat dissipation side can be rejected to a rear direction of the electric fan, quickly.  
         [0045]    In the meantime, since the heat dissipated at the heat dissipation side is not rejected to outside of an enclosed space even if the heat dissipation fins  30  or the small fan  40  is fitted to the heat dissipation side, to elevate a room temperature in overall, another heat rejection means is provided for rejecting the heat on the heat dissipation side to outside of the enclosed space.  
         [0046]    In the meantime, referring to FIGS.  7 A- 7 C, the thermoelectric module  1  employed in the thermoelectric cooler  100  may have a through hole of a circular or other forms at a center thereof in conformity with a part, such as the motor  21 , the thermoelectric module  1  is to be fitted, may be planar or cylindrical in an overall outer appearance, and, in addition to this, may be an arc form which has the smaller radius of curvature as it goes the nearer to a front side of the electrical fan, or a bent form which has a bent at a middle part, for smooth wind blow toward the motor shaft coupled to the fan blade set  22 . A size of the thermoelectric module  1  may vary with a cooling requirement.  
         [0047]    A second embodiment of the present invention will be explained with reference to FIG. 4. FIG. 4 illustrates a side view of a thermoelectric cooler in accordance with a second preferred embodiment of the present invention.  
         [0048]    Referring to FIG. 4, there is a heat pipe  50  fitted to a heat dissipation side of a thermoelectric module  1  fitted to an outer circumference of the motor  1 . As shown in FIG. 5, the heat pipe  50  includes a duplex tube of an inner tube  51  and an outer tube  52  formed of an insulating material, and both ends formed of an excellent heat conductive material. That is, as an example, the ends of the duplex tube may be formed of a good heat conductive material, such as copper, and most preferably, of a super-conductive material. An inside of the duplex tube is in a vacuum after a working fluid with an excellent heat absorptivity is injected therein. The working fluid is selected from helium, hydrogen, neon, and a mixture of them.  
         [0049]    The working fluid flows toward the heat dissipation side of the thermoelectric module  1  in the outer tube  52  in a liquid state by capillary tube phenomenon, and takes a heat from the heat absorption side, converted into a gas state, expanded to flow to the an outside of room along the inner tube  51 . Thus, a part close to the heat dissipation side of the thermoelectric module  1  within a part disposed in the room of the heat pipe  50  forms an evaporation part  53 , and a part exposed to outside of the room forms a condensing part  54 . The duplex tube is in communication at ends of the condensing part  54  and the evaporation part  53 .  
         [0050]    Upon application of a power to the thermoelectric module  1  having such a heat pipe  50  fitted thereto, the heat is dissipated at the heat dissipation side, and absorbed by the working fluid flowing along the outer tube  52  of the heat pipe  50  of a high heat conductivity. Accordingly, the working fluid absorbed a large amount of heat is vaporized by latent heat vaporization, flows toward the condensing part  54  at a very fast speed along the inner tube  51 , transfers the heat to external air at the condensing part  62  exposed to outside of room, and is condensed. The condensed working fluid flows along the outer tube  52  to the evaporation part  53  side again by capillary forces, thereby making a continuous circulation within the heat pipe  50 . On the other hand, the air cooled at the heat absorption side of the thermoelectric module  1  is blown to in a front direction of the electric fan, to drop a room temperature.  
         [0051]    Eventually, since the heat pipe  50  with a very high heat conductivity is fitted to the heat dissipation side of the thermoelectric module  1 , the second embodiment thermoelectric cooler  100  of the present invention can enhance a heat transfer efficiency even if a temperature difference between the heat absorption side and the heat dissipation side is very small because a large amount of heat can be transferred to the condensing part side through the heat pipe  50 , and dissipated therefrom to the air.  
         [0052]    Different from the general air conditioner, the second embodiment thermoelectric cooler  100  of the present invention has no noise caused by driving parts, such as compressors and the like, a long lifetime, and a significantly small power consumption, because the heat pipe  50  is fitted to the heat dissipation side of the thermoelectric module  1  to facilitate circulation of the working fluid and cooling only by heat transfer without the driving parts for forced circulation of the working fluid. In addition to this, it is apparent that the condensing part  54  of the heat pipe  50  may be designed to have a form of an increased surface area for effective heat dissipation, for an example, fins  30 .  
         [0053]    In the meantime, referring to FIGS.  6 A- 6 C, the thermoelectric module  1  of the second embodiment thermoelectric cooler  100  of the present invention may have a through hole of circular or other forms at a center thereof in conformity with a part, such as the motor  21 , the thermoelectric module  1  is to be fitted, may be planar or cylindrical in an overall outer appearance, and, in addition to this, may be an arc form which has the smaller radius of curvature as it goes the nearer to a front side of the electrical fan, or a bent form which has a bent at a middle part, for smooth wind blow toward the motor shaft coupled to the fan blade set  22 .  
         [0054]    A thermoelectric cooler in accordance with a third preferred embodiment of the present invention will be explained, with reference to FIG. 7.  
         [0055]    Referring to FIG. 7, the thermoelectric cooler  100  in accordance with a third preferred embodiment of the present invention includes a thermosiphon connected to a thermoelectric module  1  of the thermoelectric cooler  100  for rejection of heat dissipated at a heat dissipation side of the thermoelectric module  1  to outside of the thermoelectric cooler  100 . The thermosiphon  60  includes an evaporator  61  disposed in a room, and a condenser  62  disposed outside of the room. The evaporator  61  has a working fluid filled inside of a body, and a refrigerant inlet tube  163  connected to one side of a lower part thereof, and a refrigerant outlet  164  connected to the other side of an upper part thereof. The condenser  62 , one of general heat exchangers, fitted to outside of the room has fins  30  on outside of tube the working fluid flows therein for increasing a heat dissipation area, and tube connected to the evaporator  61 . The condenser  62  is placed at a position higher than the evaporator  61 .  
         [0056]    Referring to FIG. 8, the evaporator  61  is designed to have a structure in which a heat dissipation side surface of the thermoelectric device is submerged in the working fluid for an efficient transfer of the heat from the heat dissipation side of the thermoelectric device to the cooling medium filled in the coolant flow passage.  
         [0057]    Upon application of a current to the thermoelectric module  1  of the thermoelectric cooler  100  having the thermosiphon  60  fitted thereto, the heat is dissipated at the heat dissipation side, and absorbed by the working fluid in the evaporator  61  coupled to the thermosiphon  60 . The working fluid absorbed the heat is vaporized, and flows toward the condenser  62  side through the refrigerant outlet  164 . The working fluid introduced into the condenser  62  is condensed by heat exchange with external air as the working fluid flows inside of the condenser  62 , and flows into the evaporator  61  again by gravity owing to a difference of heights between the condenser  62  and the evaporator  61 . That is, the heat rejected from the heat dissipation side of the thermoelectric device is transferred to the refrigerant in the evaporator  61  the heat dissipation side is submerged therein, and rejected to the air at the condenser.  
         [0058]    Thus, the thermoelectric cooler  100  in accordance with a third preferred embodiment of the present invention can cool down room air more effectively as the heat dissipated at the heat dissipation side of the thermoelectric module  1  can be rejected to the air effectively by the thermosiphon having a simple structure and operative on a temperature difference and gravity without driving part.  
         [0059]    In the meantime, as has been explained, referring to FIGS.  7 A- 7 C, the thermoelectric module  1  employed in the third embodiment thermoelectric cooler  100  of the present invention may also have a through hole of a circular or other forms at a center thereof in conformity with a part, such as the motor  21 , the thermoelectric module  1  is to be fitted thereto, may be planar or cylindrical in an overall outer appearance, and, in addition to this, may be an arc form which has the smaller radius of curvature as it goes the nearer to a front side of the electrical fan, or a bent form which has a bent at a middle part, for smooth wind blow toward the motor shaft coupled to the fan blade set  22 .  
         [0060]    In the meantime, through each of the thermoelectric coolers of the present invention is designed such that the air cooled at the heat absorption side of the thermoelectric module  1  flows away from the heat absorption side of the thermoelectric module  1 , if the heat pipe  50  or the thermosiphon is provided like the case of the second embodiment, or the third embodiment of the present invention, the thermoelectric cooler may be designed such that the air blown by the fan blades  22  is directed to the heat absorption side of the thermoelectric module  1 , reflected at the heat absorption side of the thermoelectric module  1 , and scattered into the room.  
         [0061]    As has been explained, the thermoelectric cooler of the present invention has the following advantages.  
         [0062]    The employment of a thermoelectric module in an electric fan in the present invention permits to add a cooling function to the electric fan as air cooled down by the thermoelectric module is blown to the user, and the thermoelectric cooler of the present invention is easy to fabricate, and install, and has a low cost, significantly low noise compared to any existing air conditioner which uses a compressor and the like, and a reduced power consumption.  
         [0063]    When a small fan, a heat pipe, or a thermosiphon is employed in the thermoelectric cooler of the present invention, the cooling efficiency is enhanced because the heat dissipated at the heat dissipation side of the thermoelectric module can be rejected to the atmosphere, more effectively.  
         [0064]    It will be apparent to those skilled in the art that various modifications and variations can be made in the thermoelectric cooler of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.