Abstract:
A wind turbine with improved cooling, which provides liquid cooling for a wind turbine with a completely closed or at least partially closed cooling circuit, with which the heat to be dissipated from the cooling circuit is dissipated by a nacelle of the wind turbine. The wind turbine with improved cooling dissipates energy losses from heat and applied for the conversion of kinetic energy of wind into mechanical and electrical energy of the wind turbine.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to wind turbines and more specifically to a wind turbine with improved cooling, which provides improved cooling for components of the wind turbine. 
     2. Discussion of the Prior Art 
     Most wind turbines use heat transfer devices, such as fans to dissipate heat into the environment. In this way, cold air is suctioned in from the outside by the fans to cool wind turbine components such as the generator. The heated air is then blown back outside. Some wind turbines transfer component heat within a nacelle to a heat exchanger mounted external on the nacelle for atmosphere environment air to pass through and transfer the heat. 
     All of these known solutions have in common a large amount of air that is always needed from the outside. This is particularly disadvantageous if the outside air is humid or, particularly in coastal regions, if it has a high salt content, and the cooling elements are then exposed to this humid and high salt content air. This problem is especially extreme with wind energy facilities that stand directly on a coast or, in offshore technology, directly in salt water. Another problem is the environmental contamination of air heat exchanges being clogged and blocked. 
     Accordingly, there is a clearly felt need in the art for a wind turbine with improved cooling, which provides improved cooling for components of the wind turbine without the cooling elements being damaged by the effects of humid and/or salty air. 
     SUMMARY OF THE INVENTION 
     The present invention provides a wind turbine with improved cooling, which provides improved cooling for components of the wind turbine. One object of the invention is to provide a cooling device for a wind turbine. The basic concept of the invention is to provide a completely closed or in an alternative embodiment, a partially closed cooling circuit for a wind turbine, so that no or practically no outside air has to be used for cooling through the inside of the wind turbine. In this way, the liquid cooling media circulates within the wind turbine to a nacelle liquid reservoir that dissipates by conduction to an external surface and then cooled by convection of atmosphere wind. One option is to have a plurality of external cooling fins that are hollow with an inlet and exhaust ports to transfer liquid through each cooling fin. Another option is to have hollow cooling fins that allow the cooling liquid more surface area to transfer heat to the outside environment. 
     The cooling fluid is preferably any suitable coolant. A liquid, such as antifreeze can be used, if desired over or through wind turbine devices. A lubricating type of heat transfer oil fluid may be used to pass through the electric generator for cooling and lubrication of the generator rotor bearings. The lubricating type of oil fluid may also be used to cool and lubricate other rotating bearing systems within the wind turbine. 
     A cooling circuit that is contained within the nacelle and the plurality of cooling fins is thus closed and does require the introduction of cooled air from outside. For cooling all wind turbine components, particularly sensitive components, the wind turbine always uses the same air within the closed circuit. The cooling circuit is a closed system, and once sealed with the proper air, is not later opened or exposed to outside air. If necessary, air filters and additional cooling devices (e.g., heat exchangers) may also be mounted in the cooling path, if needed. 
     The advantages of the invention include the fact that no high salt content or humid air comes into contact with the wind turbine components, such as generators, brakes, bearings and electronics. The risk of corrosion is thus drastically reduced within the nacelle and the tower. The nacelle is a housing that contains components, such as the generator, brakes, bearing assembly, gear boxes, electronics and controls. The nacelle also includes a reservoir for retaining cooling fluid. Preferably, a plurality of internal cooling fins extend from an inner surface of the nacelle into reservoir chambers formed in the nacelle for extracting heat from the cooling liquid. Heat is transferred from the plurality of internal cooling fins to an outer surface area of the nacelle to be cooled by atmosphere wind. 
     In total, for the cooling of the entire wind turbine, considerably less energy is required than the prior art, because (secondary) cooling power is produced from the atmosphere outside of the nacelle by the wind. 
     If cooling from the plurality of external cooling fins, the plurality of internal cooling fins and passing external air is not sufficient, such as on very warm days, it is also possible to use additional cooling elements, such as conventional heat exchangers and the like in the cooling circuit. 
     For improving the cooling effect of the nacelle, the nacelle can be completely or partially made out of metal. It is preferable to use aluminum as the metal in order to also take advantage of the cooling effect of an outer surface area of the nacelle, which is constantly enveloped by wind, and thus to increase the wind turbine cooling. The outer surface area of the nacelle is cooled by atmospheric wind. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a wind turbine and an upper portion of a supporting tower. 
         FIG. 2  is perspective view of a nacelle and a pivot system of a wind turbine. 
         FIG. 3  is a front view of a nacelle and a pivot system of a wind turbine. 
         FIG. 4  is a top perspective view of an inner portion of a reservoir housing of a nacelle of a wind turbine. 
         FIG. 5  is a top view of a reservoir housing of a nacelle of a wind turbine. 
         FIG. 6  is a perspective view of a hollow external cooling fin with inlet and exhaust ports for exchanging cooling fluid from a nacelle reservoir of a wind turbine. 
         FIG. 7  is a hollow, open ended external cooling fin for receiving cooling fluid from a nacelle reservoir of a wind turbine. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference now to the drawings, and particularly to  FIG. 1 , there is shown a side view of a wind turbine  1 . The wind turbine  1  preferably includes a nacelle  4 , a rotor  6 , a pivot system  8  and a tower  10 . The nacelle  4  is pivotally retained on a top of the tower  10  with the pivot system  8 . A bottom portion of the tower  10  is anchored in the ground (not shown). The nacelle  4  houses a rotor drive shaft, generator and other components of the wind turbine  1 . The components found in the nacelle  4  are well known in the art and need not be shown or explained in detail. The rotor  6  extends from an end of a rotor drive shaft  9 . The rotor  6  includes a plurality of blades  7  and the rotor drive shaft  9 . 
     With reference to  FIGS. 2-3 , the nacelle  4  includes a shaft housing  12 , a reservoir housing  14  and a plurality of external cooling fins  16 . The shaft housing  12  may be secured to the reservoir housing  14  with any suitable method. The rotor drive shaft  9  is inserted through a drive shaft opening  20  in the shaft housing  12 . The open area between the drive shaft opening  20  and the rotor drive shaft  9  is preferably sealed from the atmosphere. The sealed nacelle  4  also protects internal components from polluted air. 
     The plurality of external cooling fins  16  preferably extend from opposing sides of the reservoir housing  14 . At least one external cooling fin  17  preferably extends from a bottom of the reservoir housing  14 . The plurality of external cooling fins  16  are preferably sloped downward and are spaced apart to keep them from being contaminated by the weather and nesting birds. The external cooling fins  17  extend from a bottom of the reservoir housing  14  to gain cooling surface area and to be parallel to the desired wind air flow  2 . Shapes of the plurality of external cooling fins  16 ,  17  shapes may be modified for thickness, taper, extension to the atmosphere, length. The number of external cooling fins  16 ,  17  may also be increased in number. The plurality of external cooling fins  16 ,  17  may be cast as an integral portion of the reservoir housing  14  or fastened to the reservoir housing  14 . The shaft and reservoir housings may completely or partially fabricated from steel, aluminum or any other suitable material. It is preferably to fabricate those portions of the shaft and reservoir housings that transfer heat to the atmosphere of aluminum. 
     The pivot system  8  preferably includes a nacelle mounting base  11  and a tower mounting flange  13 . The nacelle mounting base  11  extends upward from the tower mounting flange  13 . Preferably, pivot cooling fins  18 ,  19  extend from an outside perimeter of the nacelle mounting base  11 . With reference to  FIGS. 4-5  the nacelle mounting base  11  is inserted into a pivot tube  21  formed in the reservoir housing  14 . The pivot tube  21  is isolated from the reservoir chambers  24 ,  26 ,  28 ,  30  to allow pitch rotation of the wind turbine  1  into the wind air flow  2  and passage of electric feeds and other systems down the tower  10  to the foundation and ground (not shown). The reservoir chambers  24 ,  26 ,  28 ,  30  may be divided into at least two sub-chambers for holding more than one cooling liquid, ie: cooling oil on the port side and WEG on the starboard side. 
     The tower mounting flange  13  is mounted to a top of the tower  10  with a plurality of fasteners (not shown). The pivot cooling fins  18 ,  19  provide additional cooling for the wind turbine  1 . The stern side center fin  19  preferably has a larger surface area than the bow side center fin  18 . The larger surface area of the fin  19  acts as a tail fin to provide steering from side winds into the wind air flow  2 . 
     With reference to  FIGS. 4-5 , an inside of the reservoir housing  14  preferably includes a first reservoir chamber  24 , a second reservoir chamber  26 , a third reservoir chamber  28  and a fourth reservoir chamber  30 . The reservoir chambers  24 ,  26 ,  28 ,  30  are formed by internal bracing supports  32 ,  34 . At least one liquid passage  37  is formed through the internal bracing supports  32 ,  34  to allow the flow of cooling liquid. A plurality of internal cooling fins  36  extend inward from an inner surface area of the reservoir housing  14 . The plurality of internal cooling fins  36  transfer heat from a cooling liquid to an exterior surface area of the reservoir housing  14 . The number of reservoir chambers may be varied as desired. The cooling liquid may be a single liquid, a mixture of two or more cooling liquids or at least two cooling liquids. The cooling liquid may be circulated through the wind turbine  1  with a pump or any other suitable device. Components contained in the nacelle  4 , such as an electric generator, the rotor drive shaft  9 , speed changing gearbox transmission and electronics will benefit from the cooling liquid contained in the nacelle  4 . 
     With reference to  FIG. 6 , an external cooling fin  16 ′ is shown. The external cooling fin  16 ′ includes a hollow body, an inlet port  40  and an exhaust port  42 . The inlet and outlet ports allow the transfer of a cooling liquid through the external cooling fin  16 ′ for increased heat transfer to the atmosphere. A plurality of inlet and outlet ports would be formed through an outer surface of the reservoir housing  14 , substantially concentric with the inlet and outlet ports  40 ,  42  to allow the flow of cooling liquid into the external cooling fin  16 ′. 
     With reference to  FIG. 7 , a hollow open-ended external cooling fin  16 ′ is shown. A plurality of flow openings would be formed through an outer surface of the reservoir housing  14  to allow cooling liquid to flow into an open end  46  of the hollow open-ended external cooling fin  16 ′ for increased heat transfer to the atmosphere. 
     While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.