Abstract:
A thermoelectric module mounted on an uneven surface (a curved surface or an irregular surface) to reduce thermal boundary resistance and significantly improve thermoelectric power generation efficiency is provided. The thermoelectric module includes one or more first thermoelectric elements, one or more second thermoelectric elements having opposite polarity to that of the first thermoelectric elements and alternating with the first thermoelectric element. An electrode unit in provided and includes upper and lower electrodes configured to electrically connect the first and second thermoelectric elements. A connection member is configured to connect the first and second thermoelectric elements to vary the relative positions of the first and second thermoelectric elements.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based on and claims the benefit of priority to Korean Patent Application No. 10-2016-0046397, filed on Apr. 15, 2016, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
       BACKGROUND 
     Technical Field 
       [0002]    The present disclosure relates to a thermoelectric module and more particularly, to a thermoelectric module coupled to and mounted on an uneven surface (e.g., a curved surface or an irregular surface) to reduce thermal boundary resistance and improve the efficiency of the thermoelectric power generation. 
       Description of Related Art 
       [0003]    Typically, a thermoelectric module used in a thermoelectric power generation system utilizes the Seebeck effect that uses a difference in temperatures of both surfaces of the thermoelectric module to generate an electromotive force. During the thermoelectric power generation by the thermoelectric module, the output of the thermoelectric power generation may be increased by maintaining a substantial temperature difference between the high temperature side and the low temperature side. Accordingly, a heat transfer rate from a heat source to the thermoelectric module may significantly affect the output. 
         [0004]    Furthermore, when a conventional thermoelectric module has a flat structure and a surface of a portion of a system on which the thermoelectric module is to be mounted is curved or otherwise uneven due to uneven patterns or the like, a heat spreader, a thermal paste, or the like, may be applied to the uneven surface to planarize the corresponding surface. Following planarization of the surface, the thermoelectric module may be coupled thereto. The heat spreader, the thermal paste, or the like, increases thermal resistance and the temperature decreases in the high temperature side of the thermoelectric module. Accordingly, a temperature difference in the thermoelectric module may be reduced and the output of the thermoelectric power generation may be significantly reduced. To overcome such disadvantages, an n-type element, a p-type element, an insulating board, electrodes, and the like may be configured to have a structure that corresponds to the uneven surface. However, such a configuration may add complexity to the manufacturing process and increase manufacturing costs. 
         [0005]    The above information disclosed in this section is intended merely to aid in the understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
       SUMMARY 
       [0006]    An aspect of the present disclosure provides a thermoelectric module that is coupled to and mounted on an uneven surface while corresponding to the uneven surface. Namely, the thermal boundary resistance may be reduced and a temperature difference between the high temperature side and the low temperature side may be increased. Accordingly, the output of thermoelectric power generation may be increased. 
         [0007]    According to an aspect of the present disclosure a thermoelectric module may include one or more first thermoelectric elements, one or more second thermoelectric elements having an opposite polarity to that of the first thermoelectric elements and alternating with the first thermoelectric elements, upper electrodes that electrically connect an upper portion of the first thermoelectric element to an upper portion of the second thermoelectric element, lower electrodes that electrically connect a lower portion of the first thermoelectric element to a lower portion of the second thermoelectric element and a pivot unit disposed between the upper electrodes and/or between the lower electrodes. The pivot units may be configured to vary the relative positions of adjacent first and second thermoelectric elements. The upper electrodes may include a first upper electrode plate coupled to an upper surface of the first thermoelectric element and a second upper electrode plate coupled to an upper surface of the second thermoelectric element. The lower electrodes may include a first lower electrode plate coupled to a lower surface of the first thermoelectric element and a second lower electrode plate coupled to a lower surface of the second thermoelectric element. 
         [0008]    The pivot unit may include an upper pivot unit disposed between the upper electrodes and may be configured to vary the relative positions of the upper portions of the first and second thermoelectric elements. A lower pivot unit may be disposed between the lower electrodes and may be configured to vary the relative positions of the lower portions of the first and second thermoelectric elements. The upper pivot unit may be configured to pivotally connect adjacent first and second upper electrode plates. The lower pivot unit may be configured to pivotally connect adjacent first and second lower electrode plates. The upper pivot unit may include a pair of pivot lugs that protrude from the first and second upper electrode plates positioned adjacent to each other and a pivot bearing provided to pass through the pair of pivot lugs. 
         [0009]    The lower pivot unit may include a pair of pivot lugs that protrude from the first and second lower electrode plates disposed adjacent to each other and a pivot bearing provided to pass through the pair of pivot lugs. The upper and lower pivot units may be disposed in a zigzag pattern in a lateral (e.g., lengthwise) direction of the first and second thermoelectric elements to electrically connect in series the first thermoelectric elements to the second thermoelectric elements. The pivot bearing may be configured to pivot on an axis thereof that is parallel to at least one axis direction of a Cartesian coordinate system. The upper pivot unit and the lower pivot unit may be provided as a ball-socket joint component. 
         [0010]    The upper electrodes may include a first upper electrode plate individually coupled to an upper surface of the first thermoelectric element, a second upper electrode plate individually coupled to an upper surface of the second thermoelectric element and a third upper electrode plate coupled to an upper surfaces of at least one pair of adjacent first and second thermoelectric elements. The lower electrodes may include a first lower electrode plate individually coupled to a lower surface of the first thermoelectric element, a second lower electrode plate individually coupled to a lower surface of the second thermoelectric element and a third lower electrode plate coupled to lower surfaces of at least one pair of adjacent first and second thermoelectric elements. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The above and other objects, features and advantages of the present disclosure will be more apparent from the following detailed description when taken in conjunction with the accompanying drawings; 
           [0012]      FIG. 1  illustrates an exemplary front cross-sectional view of a thermoelectric module, according to an exemplary embodiment of the present disclosure; 
           [0013]      FIG. 2  illustrates an exemplary front cross-sectional view of a thermoelectric module, according to an exemplary embodiment of the present disclosure; 
           [0014]      FIG. 3  illustrates an exemplary front cross-sectional view of a thermoelectric module, according to an exemplary embodiment of the present disclosure; 
           [0015]      FIG. 4  illustrates an exemplary plan view in a direction of arrow A of  FIG. 3  according to an exemplary embodiment of the present disclosure; 
           [0016]      FIG. 5  illustrates an exemplary front cross-sectional view of a thermoelectric module, according to an exemplary embodiment of the present disclosure; 
           [0017]      FIG. 6  illustrates an exemplary front cross-sectional view of a thermoelectric module, according to an exemplary embodiment of the present disclosure; and 
           [0018]      FIG. 7  illustrates an exemplary side view of a thermoelectric module, according to an exemplary embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings For reference, the dimensions of elements, thicknesses of lines, and the like, illustrated in the drawings referred to in the description of exemplary embodiments of the present disclosure, may be exaggerated for convenience of understanding. In addition, terms used for describing the present inventive concept have been defined in consideration of the functions of elements, and may be altered in accordance with the intention of a user or an operator, in view of practice, or the like. Therefore, the terms should be defined on the basis of the entirety of this specification. 
         [0020]    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 or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/of” includes any and all combinations of one or more of the associated listed items. For example, in order to make the description of the present invention clear, unrelated parts are not shown and, the thicknesses of layers and regions are exaggerated for clarity. Further, when it is stated that a layer is “on” another layer or substrate, the layer may be directly on another layer or substrate or a third layer may be disposed therebetween. 
         [0021]    It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum). As referral to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles. 
         [0022]      FIG. 1  illustrates a thermoelectric module, according to an exemplary embodiment of the present disclosure. As illustrated in  FIG. 1 , the thermoelectric module, according to the exemplary embodiment of the present disclosure may include a one or more first thermoelectric elements  11 , one or more second thermoelectric elements  12  disposed to be spaced apart from the first thermoelectric elements  11 , and an electrode unit having upper and lower electrodes  21  and  22  that electrically connect the first thermoelectric elements  11  to the second thermoelectric elements  12 . The first thermoelectric element  11  and the second thermoelectric element  12  may have different polarities. In particular, the plurality of first thermoelectric elements  11  and the plurality of second thermoelectric elements  12  may be disposed alternately. The first thermoelectric element  11  may be an n-type semiconductor element and the second thermoelectric element  12  may be p-type semiconductor element, or vice versa according to circumstances. 
         [0023]    The electrode unit may be configured to electrically connect in series the first thermoelectric elements  11  to the second thermoelectric elements  12 . The electrode unit may include the upper electrodes  21  configured to electrically connect an upper portion of the first thermoelectric element  11  to an upper portion of the second thermoelectric element  12  and the lower electrodes  22  configured to electrically connect a lower portion of the first thermoelectric element  11  to a lower portion of the second thermoelectric element  12 . The upper electrodes  21  may include a first upper electrode plate  23  coupled to an upper surface of the first thermoelectric element  11 , and a second upper electrode plate  25  coupled to an upper surface of the second thermoelectric element  12 . 
         [0024]    A first upper insulating board  33  may have an area greater than or equal to that of an upper surface of the first upper electrode plate  23  and may be coupled to the upper surface of the first upper electrode plate  23 . A second upper insulating board  35  may have an area greater than or equal to that of an upper surface of the second upper electrode plate  25  and may be coupled to the upper surface of the second upper electrode plate  25 . The first upper insulating board  33  and the second upper insulating board  35  may prevent a short circuit of the first upper electrode plate  23  and the second upper electrode plate  25 . The lower electrodes  22  may include a first lower electrode plate  24  coupled to a lower surface of the first thermoelectric element  11 , and a second lower electrode plate  26  coupled to a lower surface of the second thermoelectric element  12 . 
         [0025]    A first lower insulating board  34  may have an area greater than or equal to that of a lower surface of the first lower electrode plate  24  and may be coupled to the lower surface of the first lower electrode plate  24 . A second lower insulating board  36  may have an area greater than or equal to that of a lower surface of the second lower electrode plate  26  and may be coupled to the lower surface of the second lower electrode plate  26 . The first lower insulating board  34  and the second lower insulating board  36  may prevent a short circuit of the first lower electrode plate  24  and the second lower electrode plate  26 . 
         [0026]    Accordingly, the first upper electrode plate  23  and the first lower electrode plate  24  may be disposed on the upper surface and the lower surface of the first thermoelectric element  11 , respectively. Further, the second upper electrode plate  25  and the second lower electrode plate  26  may be disposed on the upper surface and the lower surface of the second thermoelectric element  12 , respectively. For example, the first and second thermoelectric elements  11  and  12  may be individually disposed with the upper electrode plates  23  and  25  and the lower electrode plates  24  and  26 . 
         [0027]    The upper electrodes  21  and the lower electrodes  22  may be connected with a connection member. For example, in some exemplary embodiments the connection member may be an upper pivot unit  41  and a lower pivot unit  42 . Accordingly, the relative positions of the first and second thermoelectric elements  11  and  12  may be varied. In particular, the upper pivot unit  41  and the lower pivot unit  42  may be formed of a conductive material and may provide electrical paths with respect to the electrode plates  23 ,  25 ,  24 , and  26  of the first and second thermoelectric elements  11  and  12 . The upper pivot unit  41  may be disposed between the upper electrode plates  23  and  25  of the upper electrodes  21  and may vary the relative positions of the upper portion of the first thermoelectric element  11  and the upper portion of the second thermoelectric element  12 . According to exemplary embodiments of the present disclosure, the upper pivot unit  41  may be configured to pivotally connect adjacent first and second upper electrode plates  23  and  25 . 
         [0028]    As illustrated in exemplary enlarged views of  FIG. 1 , the upper pivot unit  41  may include a pair of pivot lugs  43  and  45  that protrude from the first upper electrode plate  23  and the second upper electrode plate  25 , respectively, may be disposed adjacent to each other, and a pivot bearing  47  may be configured to pass through the pair of pivot lugs  43  and  45 . Each of the pivot lugs  43  and  45  may have an aperture through which the pivot bearing  47  may pass. For example, the two pivot lugs  43  and  45  may overlap each other while allowing respective apertures thereof to correspond to each other. The pivot bearing  47  may extend on an axis P 1  and may be inserted into the apertures of the two pivot lugs  43  and  45 . The pivot bearing  47  may be formed of a conductive material and may be configured to electrically connect the first upper electrode plate  23  to the second upper electrode plate  25 . 
         [0029]    The lower pivot unit  42  may be disposed between the lower electrode plates  24  and  26  of the lower electrodes  22 , and may vary relative positions of the lower portion of the first thermoelectric element  11  and the lower portion of the second thermoelectric element  12 . According to exemplary embodiments of the present disclosure, the lower pivot unit  42  may pivotally connect adjacent first and second lower electrode plates  24  and  26 . As illustrated in the enlarged exemplary views of  FIG. 1 , the lower pivot unit  42  may include a pair of pivot lugs  44  and  46  that protrude from the first lower electrode plate  24  and the second lower electrode plate  26 , respectively, dispose adjacent to each other, and a pivot bearing  48  that may pass through the pair of pivot lugs  44  and  46 . Each of the pivot lugs  44  and  46  may have a through aperture configured to allow the pivot bearing  48  to pass therethrough. In particular, two pivot lugs  44  and  46  may overlap each other and may be configured to position respective apertures thereof to correspond to each other. The pivot bearing  48  may extend on the axis P 1  and may be inserted into the apertures of the two pivot lugs  44  and  46 . The pivot bearing  48  may be formed of a conductive material to electrically connect the first lower electrode plate  24  to the second lower electrode plate  26 . 
         [0030]    In particular, to electrically connect in series the plurality of first thermoelectric elements  11  to the plurality of second thermoelectric elements  12 , the upper and lower pivot units  41  and  42  may be disposed in a zigzag pattern in a lateral direction of the thermoelectric elements  11  and  12 . The axis P 1  of the pivot bearings  47  and  48 , according to the first exemplary embodiment, may be disposed parallel to a Z-axis direction of the Cartesian coordinate system of  FIG. 1 . Accordingly, the first upper electrode plate  23  and the second upper electrode plate  25  may be configured to pivot on the axis P 1  of the pivot bearing  47 . The first lower electrode plate  24  and the second lower electrode plate  26  may be configured to pivot on the axis P 1  of the pivot bearing  48 . 
         [0031]    The first lower insulating board  34  and the second lower insulating board  36  may be coupled to a heat source, for example, an exhaust manifold or an exhaust pipe of a vehicle, to generate a high temperature side. The first upper insulating board  33  and the second upper insulating board  35  may include a cooling unit (not shown) through which a cooling fluid passes, to generate a low temperature side. 
         [0032]      FIG. 2  illustrates a thermoelectric module, according to an exemplary embodiment of the present disclosure. An axis P 2  of the pivot bearings  47  and  48 , according to the exemplary embodiment, may be parallel to a Y-axis direction of the Cartesian coordinate system of  FIG. 2 . Accordingly, the first upper electrode plate  23  and the second upper electrode plate  25  may be configured to pivot on the axis P 2  of the pivot bearing  47 . Further, the first lower electrode plate  24  and the second lower electrode plate  26  may be configured to pivot on the axis P 2  of the pivot bearing  48 . 
         [0033]      FIGS. 3 and 4  illustrate a thermoelectric module, according to an exemplary embodiment of the present disclosure. An axis P 3  of the pivot bearings  47  and  48 , according to the exemplary embodiment, may be disposed parallel to an X-axis direction of the Cartesian coordinate system of  FIGS. 3 and 4 . Accordingly, the first upper electrode plate  23  and the second upper electrode plate  25  may be configured to pivot on the axis P 3  of the pivot bearing  47 . The first lower electrode plate  24  and the second lower electrode plate  26  may be configured to pivot on the axis P 3  of the pivot bearing  48 . In particular, the axes P 1 , P 2 , and P 3  of the pivot bearings  47  and  48  may extend to be parallel to the X-axis, Y-axis, and Z-axis directions of the Cartesian coordinate system, but are not limited thereto. The axes P 1 , P 2 , and P 3  of the pivot bearings  47  and  48  may be variously modified. 
         [0034]      FIG. 5  illustrates a thermoelectric module, according to an exemplary embodiment of the present disclosure. The pivot bearings  47  and  48 , according to the exemplary embodiment, may have different axes P 1 , P 2 , and P 3 . Any one axis P 1  of the pivot bearings  47  and  48  may be parallel to the Z-axis direction of the Cartesian coordinate system of  FIG. 5 , a second axis P 2  of the pivot bearings  47  and  48  may be parallel to the Y-axis direction of the Cartesian coordinate system of  FIG. 5 , and a third axis P 3  of the pivot bearings  47  and  48  may be parallel to the X-axis direction of the Cartesian coordinate system of  FIG. 5 . In this manner, the pivot bearings  47  and  48  may have different axes P 1 , P 2 , and P 3  that vary the relative positions of the first and second thermoelectric elements  11  and  12 . 
         [0035]      FIG. 6  illustrates a thermoelectric module, according to an exemplary embodiment of the present disclosure. According to the exemplary embodiment, the upper pivot unit  41  may include an extension component  53  that extends from the first upper electrode plate  23 , an extension component  55  that extends from the second upper electrode plate  25 , and a ball-socket joint component  59  disposed between adjacent ends of the two extension components  53  and  55 . The ball-socket joint component  59  may include a socket component  57  integrated with a first extension component  53 , and a joint ball  58  integrated with a second extension component  55 . 
         [0036]    The lower pivot unit  42  may include an extension component  54  that extends from the first lower electrode plate  24 , an extension component  56  that extends from the second lower electrode plate  26 , and a ball-socket joint component  59  disposed between adjacent ends of the two extension components  54  and  56 . The ball-socket joint component  59  may include a socket component  57  integrated with a first extension component  54 , and a joint ball  58  integrated with a second extension component  56 . In this manner, the first thermoelectric element  11  and the second thermoelectric element  12  may be configured to freely pivot by the ball-socket joint component  59  included in the upper pivot unit  41  and the lower pivot unit  42 . Accordingly, the thermoelectric module may be mounted on uneven surfaces of various shapes. 
         [0037]      FIG. 7  illustrates a thermoelectric module, according to an exemplary embodiment of the present disclosure. According to the exemplary embodiment of the present disclosure, a plurality of upper electrodes may include the first upper electrode plates  23  coupled to individual upper surfaces of a portion of the plurality of first thermoelectric elements  11 , the second upper electrode plates  25  coupled to individual upper surfaces of a portion of the plurality of second thermoelectric elements  12 , and a third upper electrode plate  27  coupled to all upper surfaces of at least one pair of adjacent first and second thermoelectric elements  11  and  12 . The third upper electrode plate  27  may be of a greater geometric size than the first upper electrode plate  23  and the second upper electrode plate  25  and may be coupled to the upper surfaces of at least one pair of adjacent first and second thermoelectric elements  11  and  12 . 
         [0038]    A plurality of lower electrodes may include the first lower electrode plates  24  coupled to individual lower surfaces of a portion of the plurality of first thermoelectric elements  11 , the second lower electrode plates  26  coupled to individual lower surfaces of a portion of the plurality of second thermoelectric elements  12 , and a third lower electrode plate  28  coupled to the lower surfaces of at least one pair of adjacent first and second thermoelectric elements  11  and  12 . The third lower electrode plate  28  may be a greater geometric size than the first lower electrode plate  24  and the second lower electrode plate  26  and may be coupled to all lower surfaces of at least one pair of adjacent first and second thermoelectric elements  11  and  12 . In addition, an integrated upper insulating board  37  having an area greater than or equal to of the area of an upper surface of the third upper electrode plate  27  may be coupled to the upper surface of the third upper electrode plate  27 . Further, an integrated lower insulating board  38  having an area greater than or equal to the area of a lower surface of the third lower electrode plate  28  may be coupled to the lower surface of the third upper electrode plate  28 . 
         [0039]    As illustrated in  FIG. 7 , the upper pivot unit  41  may be disposed between adjacent first and second upper electrode plates  23  and  25 . According to other exemplary embodiments, the upper pivot unit  41  may be selectively disposed between adjacent first and third upper electrode plates  23  and  27  or between adjacent second and third upper electrode plates  25  and  27 , which is not illustrated in  FIG. 7 . As illustrated in  FIG. 7 , the lower pivot unit  42  may be disposed between adjacent first and second lower electrode plates  24  and  26 . According to other exemplary embodiments, the lower pivot unit  42  may be selectively disposed between adjacent first and third lower electrode plates  24  and  28  or between adjacent second and third lower electrode plates  26  and  28 , which is not illustrated in  FIG. 7 . 
         [0040]    As stated above, the first and second thermoelectric elements  11  and  12  may be configured to be electrically connected in series by the pivot units  41  and  42  and may be connected individually or per pair to form various configurations. Thus, the degree of freedom in shapes of the thermoelectric module may be increased to thereby effectively compensate for the structures, shapes, and the like of the heat source and the cooling unit. As set forth above, adjacent thermoelectric elements may be connected to allow for variations in relative positions thereof to correspond to an uneven surface for example, a thermoelectric module can be closely adhered to and mounted on an uneven surface. Thus, thermal boundary resistance may be reduced and a temperature difference between the high temperature side and the low temperature side may be increased. Accordingly, the output of thermoelectric power generation may be increased. 
         [0041]    Hereinabove, although the present disclosure has been described with reference to exemplary embodiments and the accompanying drawings, the present disclosure is not limited to the disclosed embodiments. On the contrary, it is intended to cover, various modifications and equivalents arrangements altered by those skilled in the art to which the present disclosure pertains without departing from the spirit and scope of the present disclosure claimed in the following claims.