Abstract:
A cooling device for an internal combustion engine of a motor vehicle has a current-generating component that is embodied as a thermoelectric generator and has a side facing a cooling stream passing through the cooling device. The cooling stream dissipates heat generated by an operating unit of the motor vehicle. The cooling device is embodied as a vehicle radiator. The current-generating component is integrated into the vehicle radiator. The current-generating component and a cooling web of the vehicle radiator form a common assembly.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to Federal Republic of Germany patent application no. 102009058156.1-13, filed Dec. 15, 2009. 
       BACKGROUND OF THE INVENTION 
       [0002]    The invention concerns a cooling device for an internal combustion engine, in particular of a motor vehicle, comprising a current-generating component embodied as a thermoelectric generator having one side facing a cooling stream passing through the cooling device wherein the cooling stream of the cooling device dissipates heat from an operative unit of the vehicle. 
         [0003]    DE 10 2007 011 954 A1 discloses a radiator of a motor vehicle that dissipates the operating heat of the internal combustion engine of the vehicle. A so-called Seebeck element that is a thermoelectric component that produces an electric potential when a temperature differential exists is arranged on the radiator. The radiator disclosed in DE 10 2007 011 954 A1 is operated with a cooling medium whose heat is not directly passed into the surrounding ambient air but is passed to the Seebeck element for generating an electric potential. The Seebeck element is thus a thermoelectric generator. 
       SUMMARY OF THE INVENTION 
       [0004]    It is therefore an object of the present invention to improve the efficiency of motor vehicles. 
         [0005]    In accordance with the present invention, this is achieved in that the cooling device is embodied as a vehicle radiator and the current-generating component is integrated into the vehicle radiator wherein the current-generating component and a cooling web of the vehicle radiator together form a common assembly. 
         [0006]    The cooling device according to the invention is used, for example, as a radiator for internal combustion engines, in particular as a radiator of a motor vehicle, and serves for cooling one or several operating units or auxiliary units of motor vehicles, for example, for cooling an internal combustion engine, for cooling the transmission or for cooling (air conditioning) the passenger compartment. A current-generating component is integrated into the vehicle radiator and is embodied as a thermoelectric generator that generates, based on the Seebeck effect, an electric potential when a temperature differential exists. The current-generating component is a part of the vehicle radiator; this, on the one hand, has the advantage that the vehicle radiator, as a modular assembly together with the current-generating component, can be installed in the vehicle as a pre-manufactured part. On the other hand, in this way by means of the Seebeck effect an electric potential can be generated independent of the heat source in the vehicle because the vehicle radiator can be used for cooling various operating units or auxiliary units of the vehicle. Therefore, an arrangement of the current-generating component directly on the device that produces heat is not required. 
         [0007]    In one example of a current generating component using the Seebeck effect, an electric potential (voltage or thermo-electric EMF) is generated at the junction of two dissimilar metal or semiconductor components, where the electric potential generated in generally related to the temperature differential existing between the two dissimilar metal or semiconductor components. A portion of the current generating components may be electrically interconnected in series such the generated voltages are additive to provide a larger generated voltage. A portion of the current generating components may be electrically connected in parallel such the available generated current is additive. 
         [0008]    The temperature differential between the cooling stream of the vehicle radiator that dissipates the heat of the operating unit or auxiliary unit of the vehicle and of the surrounding medium, particularly the ambient air, to which the heat is dissipated, is utilized for generating the Seebeck effect. The current-generating component that functions as a thermoelectric generator is arranged on a cooling web of the vehicle radiator and forms together with it a common assembly. The cooling web has a large surface area and ensures in this way improved heat dissipation from the cooling stream to the environmental. The current-generating component is preferably positioned between the cooling stream or a cooling stream conduit and the cooling web so that the temperature differential between the cooling stream and the surrounding medium is effective in an optimal way also in the current-generating component so that the latter can thus develop its best-possible efficiency. 
         [0009]    The current that is generated at the current-generating component is preferably supplied to a battery of the motor vehicle; in this context, principally an immediate operation of an electric component within the vehicle is also conceivable, for example, a heat generating component that is based on the Peltier effect and that, for example, is utilized for heating temperature-sensitive components of the vehicle or for heating the passenger compartment of the vehicle. 
         [0010]    The current-generating component and at least one cooling web in the radiator form together a common assembly; this can be realized in various ways. For example, it is possible to manufacture the cooling webs and the current-generating component each as separate individual parts that are to be joined to each other; in this case, the current-generating component expediently is located at the exterior wall of the cooling web. In case of such a separate configuration, the current-generating component, for example, is a laminate or a film that is applied to the exterior side of the cooling web. The laminate or film can be applied over a large surface area of the cooling web so that the temperature differential between the cooling stream and the cooling web can be utilized accordingly across a large surface area. 
         [0011]    Basically, it is also possible to join the current-generating component and the cooling web to form a unitary component. In this case, the current-generating component and the cooling web are embodied as a one-part unit, for example, in such a way that the wall of the cooling web is formed as a current-generating component. This can be realized, for example, in such a way that the cooling web is of a three-layer configuration wherein the two outer layers are comprised of a light metal and the inner layer is comprised of a thermoelectric material. The outer layers in the electric sense constitute ground or the negative terminal while the inner thermoelectric layer constitutes the electric potential or the positive terminal whose voltage is tapped and either supplied to the battery or used for operating a motor vehicle component. 
         [0012]    The three-layer configuration has moreover the advantage that the temperature differential between each one of the two outer layers and the inner layer, respectively, can be utilized for generating a potential so that the temperature differential is effective in opposite directions. This is conceivable particularly in embodiments in which a cooling web is arranged between two cooling streams or cooling stream conduits so that at both external sides of the cooling web higher temperatures and at the inner side a lower temperature exist. This temperature gradient is effective relative to the current-generating component in both directions so that the efficiency is further improved. 
         [0013]    In principle, it is also possible to have a configuration of the wall of the cooling web with two layers wherein preferably one layer is made of light metal and a further layer is made of a thermoelectric material. In this embodiment, the temperature gradient in one direction can be utilized for generating electric potential, namely based on the hot cooling stream dissipating heat through the cooling web to the surrounding medium at lower temperature. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0014]    Further advantages and expedient embodiments are disclosed in the claims, the figure description, and the drawings. 
           [0015]      FIG. 1  shows a section of a vehicle radiator with a plurality of cooling webs wherein the cooling webs are arranged between two cooling stream conduits, respectively, wherein on the cooling webs current-generating components are disposed that are embodied as thermoelectric generators for generating an electric potential as a result of a temperature differential in the current-generating components. 
           [0016]      FIG. 2  is a detail view of the vehicle radiator in the area of several current-generating components connected to one another by a bus rail. 
           [0017]      FIG. 2   a  is an embodiment variant in which a cooling web is embodied simultaneously as a current-generating component. 
           [0018]      FIG. 3  is a schematic illustration of a motor vehicle with a vehicle radiator arranged at the front end and embodied with current-generating components. 
           [0019]      FIG. 4  is a detail view of a current-generating component that is embodied as a laminate applied onto a support body. 
           [0020]      FIG. 5  is a cooling web in an undulated shape with a current-generating component that is located at the base of a U-shaped wave of the cooling web. 
           [0021]      FIG. 6  shows that the current-generating components themselves are embodied as cooling webs and are applied in an undulated shape onto the cooling stream conduits. 
       
    
    
       [0022]    In the Figures same components are identified with same reference numerals. 
       DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0023]    The vehicle radiator  1  illustrated in  FIG. 1  is in particular a radiator of a motor vehicle that is arranged in the front area of the motor vehicle. The vehicle radiator  1  comprises a plurality of parallel-positioned cooling webs  2  between which a cooling medium conduit  3  extends, respectively, that conducts the medium to be cooled. i.e., the cooling stream. The cooling medium is guided, coming from each operating unit or auxiliary unit within the vehicle, to a collector  4  of the vehicle radiator  1  and from here the cooling stream branches off into each cooling stream conduit  3  between the cooling webs  2 . The cooling stream conduits  3  are in particular embodied as flat aluminum channels. 
         [0024]    Each cooling web  2  has correlated therewith a current-generating component  5  that functions as a thermoelectric generator and is comprised of a material that generates, based on the so-called Seebeck effect, an electric potential when a temperature differential is present. The temperature differential exists between the hot cooling stream within the cooling stream conduit  3  and the cooling webs  2 . In this direction, a temperature drop exists which is effective in the current-generating component  5  that is positioned between the cooling stream conduits  3  and the cooling webs  2 . Based on the thermoelectric effect within the current-generating component  5  an electric potential is generated that is tapped and either supplied to a battery for storage as electric energy or is used for driving or for generating temperature in an electric component within the motor vehicle. 
         [0025]    In the embodiment according to  FIG. 1 , there is a plurality of current-generating components  5  that each are formed flat or plate-shaped and are disposed on both faces of each cooling web  2 , respectively. Viewed in the direction of the length of the cooling web  2 , on each face several individual current-generating components  5  are arranged and two immediately adjacently positioned current-generating components  5  are electrically connected to each other, respectively, by an electric contact bridge  6 . As a result of this serial connection, a higher electric potential is achieved that is available for storage or for operating an electric component. 
         [0026]    The cooling webs  2  are of a wave shape or undulated shape wherein the plate-shaped current-generating components  5  each are contacting the oppositely positioned peaks or valleys of the cooling webs  2 , respectively, as shown in  FIG. 1 . In a further embodiment, indicated in  FIG. 1  in dashed lines, the current-generating component  5  is embodied as a laminate and is applied immediately onto the wall of the cooling web  2 . This has the advantage that the current-generating component  5  covers a larger surface area that basically corresponds to the surface area occupied by the wave-shaped cooling web. 
         [0027]      FIG. 2  shows a detail of the vehicle radiator  1  with a bus rail  7  that serves for electrically connecting parallel-arranged individual current-generating components  5 . The electric contact  8  represents the negative terminal (electric ground), the electric contact  9  the positive terminal which, relative to electric ground, represents the electric potential that is tapped at the bus rail  7  and is utilized for storage in the battery or for operating an electric component. 
         [0028]      FIG. 2   a  shows an embodiment variant of a cooling web  2  that forms simultaneously a current-generating component  5 . The cooling web  2  is wave-shaped with a U-shaped profile and is comprised of three layers  10 ,  11 ,  12  wherein the two outer layers  10 ,  11  expediently are made of light metal such as aluminum and the central layer or inner layer  12  is comprised of a thermoelectric material. The outer layers  10 ,  11  ensure stability, on the one hand, while they also provide excellent heat dissipation, on the other hand; moreover, the thermoelectric inner layer  12  is protected by the two outer layers  10 ,  11 . A cooling web  2  that is embodied in this way as a one-part component together with the current-generating component  5  no longer requires a separate current-generating component. 
         [0029]    The three-layer embodiment of the cooling web  2  or of the current-generating component  5  has moreover the additional advantage that a temperature gradient of two outer layers  10  and  11  relative to the inner layer  12  can be utilized for current generation. In this way it is possible to utilize the heat that is contained in the cooling stream on the first face as well as the opposite second face of the cooling web for current generation so that efficiency is increased. 
         [0030]      FIG. 3  shows in a schematic illustration a motor vehicle  13  that in the front area is provided with the vehicle radiator  1  comprised of several individual cooling elements  14  to  17 . The individual cooling elements  14  to  17  serve for cooling a cooling medium that is correlated with one component or operating unit of the vehicle, respectively. For example, the vehicle radiator  1  comprises a servo oil cooling element  14 , an air-conditioning cooling element  15 , a charge air cooling element  16  as well as a cooling water element  17 . These individual cooling elements are combined and integrated into the vehicle radiator  1 . 
         [0031]    Expediently, each one of the individual cooling elements  14  to  17  has at least one current-generating element correlated therewith that utilizes the temperature differential between the cooling medium in each individual cooling element and the ambient air for current generation. The electric potential (positive terminal) generated in total is stored in a battery  18  in the motor vehicle or can be used, for example, in assisting the drive action of an electric motor  19  that is used for driving the rear wheels. 
         [0032]    In  FIG. 4  a further embodiment of a current-generating component  5  is illustrated which is embodied as a laminate and is applied onto the exterior wall of the cooling web  2 . As a result of the flexibility of a laminate (optionally also a film or foil can be used in this application), the current-generating component  5  can be applied onto the exterior wall of the cooling web  2  before shaping the cooling web  2  and can then be shaped together with the cooling web  2 . 
         [0033]    In the embodiment according to  FIG. 5  the cooling web  2  and the current-generating component  5  are embodied as separate components. The current-generating component  5  is located at the base of a U-shaped wave of the undulated cooling web  2 . 
         [0034]    In the embodiment according to  FIG. 6 , the current-generating components  5  themselves are embodied as cooling webs and are applied in a wave shape onto the cooling stream conduits  3 . In this case, the valley and peaks of oppositely positioned cooling webs engage each other as shown. 
         [0035]    While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.