Abstract:
A tower and wind turbine supporting structure which at least partially envelops the tower. The tower is of uniform cross sectional configuration throughout and has a plurality of outriggers. The outriggers are connected with the tower after the wind turbines and their supporting structure have been positioned at the base of the tower, raised to their point of attachment and secured in place. Individual foundation members for each vertical tower member and for each outrigger are in the form of micro piles and may include a plurality of micro piles and a manifold for maintaining upper end portions thereof in desired positions. Another aspect of the method of the invention involves providing a tower of uniform cross section, positioning wind turbines and their supporting structures sequentially at the base of the tower, raising them and mounting them on the tower sequentially, and thereafter providing a plurality of outriggers and their foundations and attaching them to the tower.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a Continuation-in-Part of U.S. patent application Ser. No. 12/217,916 entitled TOWER AND WIND TURBINE SUPPORTING STRUCTURES AND METHOD FOR MOUNTING THE LATTER, FILED Jul. 9, 2008, invented by Russel H. Marvin et al, 
         [0000]    U.S. patent application Ser. No. 12006024 entitled IMPROVED INLET PASSAGEWAY AND SEALING IN A TURBINE WIND POWER GENERATING SYSTEM filed Dec. 28, 2007, invented by Russel H. Marvin, hereby incorporated herein by reference, and
 
U.S. patent application Ser. No. 12077556 entitled ACCELERATOR FOR USE IN A WIND POWER ELECTRICAL GENERATING SYSTEM, filed Mar. 28, 2008 invented by Russel H. Marvin, also incorporated herein by reference.
 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The construction of wind turbines and associated apparatus on supporting towers at elevations reaching hundreds of feet is a difficult, dangerous and very expensive proposition. Further, the massive foundations required for the exceptionally high towers are also a major component of the overall cost of wind turbine generation of electrical power. 
         [0003]    Accordingly, it is a general object of the present invention to provide a tower and wind turbine supporting structure configuration and a method of mounting wind turbines and their supporting structures on the tower which dramatically reduces the overall cost of construction of a wind turbine electrical generating system. 
         [0004]    A further object of the invention resides in the provision of an improved foundation system which can be installed employing a relatively simple process involving a minimum number of steps at substantial economic advantage and which is yet highly efficient and efficient in operation. 
       SUMMARY OF THE INVENTION 
       [0005]    In accordance with the present invention and in fulfillment of the foregoing object a tower is provided for mounting wind turbines and their supporting structures which at least partially envelop the tower at elevated positions for enhanced wind velocities. The tower comprises a plurality of horizontally spaced apart vertically extending narrow elongated and lightweight main members and a plurality of shorter narrow lightweight interconnecting cross members extending between the vertical members and cooperating therewith to form a massive monolithic structure having a vertical dimension of at least thirty (30) feet. In the illustrative embodiment of the invention shown and described herein below a tower of two hundred (200) feet in height is provided and the exterior cross sectional configuration and dimensions of the tower from its base to the area of attachment of the wind turbine supporting structures is substantially uniform. A power operated lifting device is provided at the base or the top of the tower as shown and has at least one (1) connected lift line, two (2) shown. Adjacent the base of the tower a plurality of diagonally extending outriggers are also provided for attachment to the tower after the turbines and their supporting structures have been positioned adjacent the tower at its base, raised by the power lifting device, and secured in place at their respective operating positions. 
         [0006]    The outriggers are spaced apart horizontally about the tower and each is of narrow elongated and lightweight but rigid construction longitudinally providing support against both tension and compression loading. Each outrigger has its upper end portion connected to the tower in supporting relationship therewith and its lower end portion is disposed in horizontally spaced relationship with the tower at least approximately at ground level. 
         [0007]    Finally, a foundation system is provided and supports each vertical member of the tower and each outrigger individually at its lower end portion. More particularly, the foundation system preferably comprises an individual foundation for each tower and outrigger member supported thereby, each foundation system including a member of narrow elongated configuration and of composite metallic and concrete construction. The elongated foundation members extend downwardly from their supported members into the earth a substantial distance and provide effective resistance against both compression and tension forces Micro piles are presently preferred. 
         [0008]    In another embodiment of the invention, the vertical members of the tower and the outriggers may be supported by micro piles extending from their supported members to anchors in bedrock which is reasonably close to the surface. 
         [0009]    In an alternative embodiment of the invention three (3) micro piles are provided for each main structural member of the tower and each outrigger and have associated manifolds which receive the inner members of the micro piles through openings and maintain the same in a desired “splayed” configuration. The manifolds also serve as guides during drilling and other activity occurring in formation of the foundations with the inner members of the micro piles passing through their openings and properly aligned and guided thereby. 
         [0010]    Preferably, the wind turbine and support structures carry a pair of turbines on opposite sides of the support structure with a pair of wind accelerating surfaces or passageways respectively capturing and accelerating a flow of wind to the turbines. A wide variety of wind turbine and supporting structures may be employed but the turbine and support structure or “accelerator” design of the aforementioned patents is presently preferred. In this embodiment a cylindrical supporting structure completely surrounds the tower and the tower is of substantially uniform cross section throughout its height. In other embodiments of the invention when the tower may for example have a rectangular cross section with wind turbine supporting structures of generally U-shaped or parti-circular cross section, the relationship between the tower and the supporting structures is established such that the tower exterior dimensions are less than those of the supporting structures at least in the areas where they reside in adjacent relationship during raising and assembly. Thus, for example the fourth exposed side of a rectangular tower may take a completely irregular configuration. 
         [0011]    In accordance with a method of the invention a tower of the desired height and substantially uniform cross section from its base to the desired area of attachment of the wind turbines and their supporting structures is first constructed. At least one wind turbine and its assembled supporting structure is then positioned on the ground adjacent the base of the tower. The wind turbine and support structure is thereafter raised to its desired point of attachment and secured in place. At least three diagonal outriggers and their respective foundations are then provided and the upper end portions of the outriggers are connected to the tower in spaced relationship thereabout, the lower end portions of the outriggers being attached to their respective foundations. 
         [0012]    When each wind turbine and supporting structure comprises a pair of turbines arranged on opposite sides thereof the turbines are spaced apart between 150 and 210 degrees and are approximately one hundred and seventy (170) degrees apart in the presently preferred embodiment of the invention. Each supporting structure at least partially envelops the tower and provides at least one surface to capture the wind and accelerate flow to the turbines. Further, when a plurality of wind turbines and supporting structures are provided, the wind turbines and supporting structures are disposed sequentially adjacent the base of the tower, raised sequentially to their desired positions and attached proceeding from the uppermost wind turbine and supporting structure downwardly to the lowermost. 
         [0013]    As will be apparent, the method of the invention accommodates the construction of the wind turbines and their supporting structures on the ground and thus avoids the excessive labor and/or crane costs encountered with construction at high elevations. 
         [0014]    Optionally, the wind turbines and supporting structures may be manufactured completely on site or manufactured in sections off-site, transported to the site and thereafter assembled sequentially adjacent the tower base. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a somewhat schematic elevation showing a tower without outriggers during practice of the method of the invention, a wind turbine and its supporting structure being shown at the base of the tower and a power lifting device at the top of the tower. 
           [0016]      FIG. 2  is a view in elevation similar to  FIG. 1  but showing the tower, wind turbines and supporting structures mounted thereon, outriggers in place about the base of the tower with foundation members supporting the tower and outriggers, and 
           [0017]      FIG. 3  is a fragmentary view in elevation showing a lower portion of the tower and outriggers in greater detail. 
           [0018]      FIG. 4  is an enlarged fragmentary perspective view showing a manifold and lower end portions of an outrigger comprising three (3) tubular members with a three member foundation, and 
           [0019]      FIG. 5  is an enlarged fragmentary perspective showing a manifold and a connecting bracket associated with a three member foundation and main structural member of a tower, and 
           [0020]      FIG. 6  is a fragmentary sectional view showing a guide and manifold with associated foundation members during drilling and formation of the micro pile. 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0021]    Referring in particular to  FIGS. 1 and 2 , a tower for mounting wind turbines and their supporting structures is indicated generally at  10  with the tower proper at  12 , supporting structures at  14 , 14  and turbines at  16 , 16 . The illustrative tower  12  shown has a height A of approximately two hundred (200) feet. As best illustrated in  FIG. 3 , the tower  12  includes a plurality of narrow elongated vertically extending main longitudinal members  18 , 18 , preferably tubular, and a plurality of shorter narrow interconnecting cross members  20 , 20 . The cross members  20 , 20  may be tubular or triangular in cross section in a truss structure. The members  20 , 20  extend between the members  18 , 18  and cooperate therewith to form a massive monolithic structure having a vertical dimension of at least fifty (50) feet, 200 feet as shown and mentioned above. The cross sectional configuration and other structural characteristics of the tower may vary but in all cases the cross sectional dimensions and configuration of the tower from its base to the area of connection with the wind turbine supporting structures must be at least partially uniform to permit raising of the wind turbines and their supporting structures thereabout. The tower  12  is of a presently preferred triangular vertically uniform cross sectional configuration with the short cross members  20 , 20  extending diagonally between the vertical members  18 , 18 . 
         [0022]    Mounted at or near the top of the tower is a power operated lifting device  21  which is shown with a pair of depending lift lines  23 , 23  respectively on opposite sides of the tower  12  and connected with a wind turbine supporting structure  14  at the base of the tower. 
         [0023]    The wind turbines  16 , 16  and their supporting structures  14 , 14  may vary widely in construction but as mentioned above are preferably of the cylindrical type disclosed in the aforementioned patents and completely surround the tower  12 . It should also be noted that the supporting structures are mounted for incremental rotation about the tower in adjusting the position of the turbines for optimum performance in response to changes in the direction of wind flow. 
         [0024]    As best illustrated in  FIG. 3 , a plurality of longitudinally rigid outriggers are provided for support in both tension and compression. As shown, three (3) outriggers  22 , 22  are provided and each outrigger  22  is of tubular metallic construction with three (3) longitudinally extending elongated tubular members  24 , 24  in a triangular configuration and with a plurality of shorter tubular members  26 , 26  interconnecting the longitudinal members. The outriggers  22 , 22  have their upper end portions connected in supporting relationship with the vertical longitudinally members of the tower; three (3) outriggers being provided for the triangular tower  12 . Preferably, the connection of the outriggers with the tower is effected at the point where at least one cross member  20  also connects with a vertical member  18 . The outriggers have a length B in the range twenty (20} to one hundred (100) feet and, in the illustrative embodiment shown, the outriggers have a length B of approximately fifty (50) feet. The outriggers are at an angle with the vertical in the range of thirty (30) to eighty (80) degrees, the preferred angle being approximately sixty (60) degrees. 
         [0025]    At lower end portions the outriggers  22 , 22  are preferably provided with separate foundation members in the form of elongated members  28 , 28  of composite metallic and concrete construction. As shown, the foundation members  28 , 28  take the form of micro piles of the type sold and installed by CON-TECH K SYSTEMS LTD. of 8150 River Road, Delta, B.C. Canada V4G 1B5 under the trademarks SCHEBECK and TITAN and extend downwardly into the earth at angles substantially the same as that of the members which they support. The length of the micro pile members should be in the range of twenty (20) to fifty (50) feet and in the illustrative embodiment shown, the outrigger foundation members  28 . 28  are approximately thirty (30) feet long. 
         [0026]    When bedrock is reasonably close to the surface, the foundation members  28 , 28  may be supported by anchors  19  embedded in the bedrock, one shown on the right hand member  28  in  FIG. 2 . 
         [0027]    Foundation members  30 , 30  for the vertical members  18 , 18  of the tower  12  are preferably the same as those for the outriggers with the length of the members falling in the range of twenty (20) to fifty (50) feet. In the illustrative embodiment shown the length of the members  30 , 30  is approximately thirty (30) feet and the members extend vertically, downwardly from the vertical members which they support. 
         [0028]    In accordance with the method of the invention, and as mentioned above, a tower at least partially uniform in cross section is provided and the wind turbines and their supporting structures are positioned at the base of the tower, raised to the area of attachment, and secured in place. When twin turbines are provided, the supporting structures at least partially envelope the base of the tower and may be manufactured off-site in sections and assembled around the tower base, or they may be manufactured on site about the tower base. Thereafter, when all of the wind turbine and supporting structures have been raised and secured in place, the outriggers may be assembled with the tower and their foundations to complete the installation. 
         [0029]      FIG. 4  et sequa illustrate an alternative embodiment of the invention with improved foundation systems providing a higher degree of structural integrity and superior stability for the tower and its wind turbines even in hurricane conditions. Referring particularly to  FIG. 4 , lower end portions  40 ,  40  of three (3) elongated tubular members forming an outrigger are shown connected by flanges  42 ,  42  with short tubular connecting tubes  44 ,  44 . The connecting tubes are open at their lower ends and receive upper end portions of tubular metallic inner members  46 ,  46  of micro piles  48 ,  48 . External nuts  50 ,  50 , one shown, cooperate with nuts internally of the connecting tubes together with bearing plates in affecting connections between the outriggers  40 ,  40  and the tubular inner members  46 ,  46  of the micro piles. 
         [0030]    A manifold  52 , which is preferably of precast concrete, has three (3) openings  54 ,  54  for receiving the inner members  46 ,  46  of the micro piles. A hardenable medium  56  fills the gaps between the walls of the openings  54 ,  54  and the tubular micro pile members  46 ,  46 , the former being somewhat larger in diameter than the latter. 
         [0031]    As will be apparent from the forgoing, the upper end portions of the tubular members  46 ,  46  of the micro piles are maintained in desired pre-determined positions by means of the manifold  52 , and as will be described herein below, the manifold  52  also serves as a guide during the formation of the micro piles whereby to establish desired predetermined angular relationships of the micro piles. 
         [0032]    In  FIG. 5 , a manifold  58  is shown for establishing connection of tubular upper end portions  60 ,  60  of micro piles  62 ,  62 . The manifold  58  is also constructed of precast concrete in presently preferred form and has three through openings  64 ,  64 , two shown, for receiving the tubular inner members  60 ,  60  of the micro piles. A hardenable medium  66 ,  66  fills gaps between the tubular members  60 ,  60  and the walls of the openings  64 ,  64 . At upper end portions, the members  60 ,  60  are connected with a manifold type bracket  68  which has three (3) flanges  70 ,  70 , two shown. The flanges  70 ,  70  have openings for receiving the members  60 ,  60  and associated upper and lower nuts  72 ,  74  secure the members  60 ,  60  in the openings in the flanges  70 ,  70 . At its upper end, the manifold type bracket  68  carries a large flange  76  for connection with a main vertical structural member of a wind turbine tower. An associated truss member may be connected with the bracket  78 . 
         [0033]    The micro piles  48 ,  48  and  62 ,  62  extend a substantial distance downwardly into the earth and are between 20 and 50 feet in length, preferably approximately 30 feet long for both the outriggers and the main structural members of the tower. Further, the micro plies extend in a “splayed” relationship with each other,  FIG. 6 , for maximum effectiveness in both compression and tension. The angular relationship of the micro piles with respect to the centerlines of their supported members may vary but it is preferred to maintain a displacement of approximately 3 degrees from the centerlines of the outriggers and a displacement of approximately 10 degrees from the centerlines of the structural members of the towers. 
         [0034]    Referring now to  FIG. 6 , the template function of the manifolds  52 ,  58  is illustrated subsequent to the drilling operation and the injection of concrete through a tube such as  60   a . The tube  60   a  may be entered in an opening  54   a  and maintained in position on completion of drilling and concrete injection by means one or more small inserts  80 ,  80  positioned in the opening  54   a . A first insert  80  is shown in the opening  54   a  in  FIG. 6  and a second insert  80  is shown above the upper end of the tube  60   a . As will be apparent, the inserts  80 ,  80  will serve to maintain the tubular member  60   a  in a desired angular position when drilling and formation of the micro pile is complete with the concrete remaining in an unhardened condition. The inserts  80 ,  80  are retained in the opening  54   a  during grouting of the opening  54   a  with hardenable medium and insure precise final positioning of the upper ends of the members  60   a ,  60   a  for connection with their respective supported members. 
         [0035]    As will be apparent from the forgoing, both an improved tower and an improved foundation system have been provided with substantial savings achieved particularly in the foundation system. 
         [0036]    The erection method of the invention also provides for substantial savings in avoidance of the excessive cost of labor and large cranes for assembly or repair of the wind turbines and supporting structures at high elevations.