Abstract:
A power generation system is provided that can capture and convert kinetic energy from waves in open water into hydraulic or electrical energy. The system includes one or more platforms that include buoyant arms which extend outwardly from the platform for interaction with waves passing around and beneath the platform. The arms are pivotally secured to the platform and are capable of moving between points above and below the still water level in order to more effectively contact, i.e., float on, the waves as they pass. Opposite the waves, the arms are operably connected to a hydraulic system in order that the fluid in the hydraulic system is effectively pumped by the motion of the arms as a result of the movement of arms resulting from their interaction with the waves. In turn, the hydraulic fluid pumped by the arms serves to operate a hydraulic motor that drives an electric power generator that provides an easily transportable source of power that can be directed to any suitable power transfer station.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from U.S. Provisional Application Ser. No. 61/263,287, filed on Nov. 20, 2009, the entirety of which is expressly incorporated by reference herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to power generation devices, and more specifically to devices which generate power from the motion of waves. 
       BACKGROUND OF THE INVENTION 
       [0003]    Moving water has long been considered to be a potential and limitless source of ecologically safe power derived from the constant, and virtually perpetual motion of the water. In one application of this concept, the kinetic energy of water moving over or through a hydroelectric dam is utilized to generate electrical power. However, building a highly resource and time intensive structure across a river is often not practical, and the number of potential locations for such a structure is also limited. 
         [0004]    As an alternative to a river as a source of power, attempts have been made in the past to harness the motion of waves in open water as they approach the shore. These attempts have focused on the capture of the kinetic energy from the tidal motion of the body of water and include tidal barrages, tidal fences, and tidal turbines. However, these approaches have certain significant drawbacks, such as expensive on-site installation and maintenance. 
         [0005]    Still another alternative is the capture of the kinetic energy from the motion of the waves out in open water. The structures utilized for this purpose are most often constructed as floating platforms that have elements that interact directly with the waves as they pass the structure to convert the kinetic energy of the waves into a more directly useful form of energy. 
         [0006]    These prior art platforms suffer from some significant drawbacks that prevent an effective and efficient capture of the energy from the waves. In particular, the elements on the platforms are only able to interact with the wave over a portion of the wave curve, meaning a significant portion of the energy carried by the wave is lost. This, in turn, makes the output of the platform much less efficient, and therefore, reduces the viability of the platform as an effective source of energy. 
         [0007]    In addition, to effectively and efficiently capture the energy from the waves for conversion into useful forms of energy, the device interacting with the waves must be oriented with respect to the waves in a manner that most effectively interacts with the waves. In prior art devices, this has been difficult to achieve. 
         [0008]    Therefore, it is desirable to develop a device for capturing and converting the kinetic energy of waves into a more directly useful form of energy, such as electrical energy, that can interact with the waves in a highly efficient manner to maximize the energy output of the device. 
       SUMMARY OF THE INVENTION 
       [0009]    According to a one aspect of the present invention, a power generation system is provided that can capture and convert kinetic energy from waves in open water into hydraulic or electrical energy. The system includes one or more platforms that include buoyant arms which extend outwardly from the platform for interaction with waves passing around and beneath the platform. The arms are pivotally secured to the platform and are capable of moving between points above and below the still water level in order to more effectively contact, i.e., float on, the waves as they pass. Opposite the waves, the arms are operably connected to a hydraulic system in order that the fluid in the hydraulic system is effectively activated by the motion of the arms as a result of the movement of arms resulting from their interaction with the waves. In turn, the hydraulic fluid pumped by the arms serves to operate an electric power generator via a hydraulic motor which provides an easily transportable source of power that can be directed to any suitable power transfer station. 
         [0010]    According to another aspect of the present invention, the hydraulic system is configured to be operated by the arms when the arms move both above and below the still water level to maximize the energy output of the system. Further, the hydraulic system is operable as a result of the simultaneous and independent movement of each of the arms in the same or opposite directions, such that the hydraulic system generates fluid flow to operate the electric generator regardless of the individual positions of the arms. 
         [0011]    According to a further aspect of the present invention, the configuration of the arms in the power generation system enable the arms to interact with waves approaching the system from virtually any direction, to maximize the movement of the arms, and the resulting power generation from the system. The configuration of the arms allows the power generation system to be deployed in any position with relation to the direction of the waves. 
         [0012]    According to still another aspect of the present invention, the arms are each separately connected to the hydraulic system, such that each arm can be disconnected from the system for various reasons, while the remainder of the arms continue to provide the driving force to operate the hydraulic system. 
         [0013]    According to still another aspect of the present invention, the apparatus allows for an uninterrupted and continuous energy source even when wave motion is minimal. At low wave heights, running a select number of motors allows for even the slightest wave motion to be captured into electricity. 
         [0014]    Numerous other aspects, features, and advantages of the present invention will be made apparent from the following detailed description together with the drawings figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The drawings illustrate the best mode currently contemplated of practicing the present invention. 
           [0016]    In the drawings: 
           [0017]      FIG. 1  is an isometric view of a first embodiment of a power generation system constructed according to method of the present invention; 
           [0018]      FIG. 2  is an isometric view of a second embodiment of the power generation system of  FIG. 1 ; 
           [0019]      FIG. 3  is a cross-sectional view along line  3 - 3  of  FIG. 1 ; 
           [0020]      FIG. 4  is a cross-sectional view along line  4 - 4  of  FIG. 2 ; 
           [0021]      FIG. 5  is a partially broken away, isometric view of the attachment of an arm to a platform of the system of  FIG. 1 ; 
           [0022]      FIG. 6  is a partially broken away, isometric view of the attachment of an arm to a platform of the system of  FIG. 2 ; 
           [0023]      FIG. 7  is a partially broken away side plan view of the operation of the arm of the system of  FIG. 1 ; 
           [0024]      FIG. 8  is a partially broken away side plan view of the operation of the arm of the system of  FIG. 2 ; 
           [0025]      FIG. 9  is a side plan view of the operation of the system of  FIG. 1 ; 
           [0026]      FIG. 10  is a side plan view of the operation of the system of  FIG. 2 ; 
           [0027]      FIG. 11  is a side plan view of the operating positions of a hydraulic cylinder of the system of  FIG. 2 ; 
           [0028]      FIG. 12  is a top plan view of a first embodiment of the arm of the system of  FIG. 2 ; 
           [0029]      FIG. 13  is a top plan view of a second embodiment of the arm of the system of  FIG. 1 ; 
           [0030]      FIG. 14  is a schematic view of the hydraulic system of the power generation system of  FIG. 1 ; 
           [0031]      FIGS. 15A-15C  are schematic views of the operational conditions of the hydraulic system at the arm positions shown in  FIGS. 7 and 8 ; and 
           [0032]      FIGS. 16A-16D  are top plan views of various arrangements of the power generation system of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0033]    With reference now to the drawing figures in which like reference numerals designate like parts throughout the disclosure, a power generation system constructed according to the present invention is indicated generally at  100  in  FIG. 1 . The system  100  includes a platform  102  formed as a watertight enclosure of a suitable material capable of withstanding the harsh environment in which the platform  102  is located, such as a metal, including steel, aluminum, or their alloys, among others. The platform  102  is hollow, which provides the platform  102  with sufficient buoyancy to enable the platform  102  to float, and enables various additional components of the system  100  to be positioned therein. The shape of the platform  102  can vary as desired, and can be a cylinder or a prism, which is defined as a polyhedron with two congruent and parallel faces, and whose lateral faces are parallelograms. 
         [0034]    As best shown in  FIGS. 1 and 3 , one exemplary embodiment the platform  102  is generally square in shape and includes a top surface  104 , a number of downwardly depending side surfaces  106  joined to the top surface  104 , and a bottom surface  110  connected to the side surfaces  106 . 
         [0035]    To affix the platform  102  in a designated location, a number of mooring elements  112  are secured between the platform  102  and the floor  114  of the body of water on which the platform  102  is positioned. Each mooring element  112  includes a weight or base  116  which rests on the floor  114 , and a cable or other suitable tethering member  118  that extends and is connected between the platform  102 , e.g., the bottom surface  110 , and the base  116 . The mass of the base  116  is sufficient alone or in combination with additional bases  116  from additional mooring elements  112  to maintain the platform  102  in a relatively stationary location above the bases  116 . Further, in one embodiment, the bases  116  are formed to simply rest on the surface of the floor  114 , such that the bases  116  can be lifted off of the floor  114  when it is desired to reposition or remove the platform  102  from the body of water. The tethering members  118  are, in one embodiment, selected to have a length that enables the platform  102  to remain above the level of the highest wave height at a given location. The mooring elements  112  also are constructed and configured to avoid twisting about themselves or each other, and to prevent the tethering members  118  from interfering with other vessels, such as repair or maintenance vessels, that may approach the platform  102 . 
         [0036]    Referring now to  FIGS. 1 ,  3 ,  5 ,  7 , and  9 , extending outwardly from each side surface  106  of the platform  102  are a number of arms  120 . The arms  120  are each watertight, hollow and formed from a material similar to that of the platform  102  to enable the arms  120  to float on the surface of the body of water. Each arm  120  can be formed with any desired cross-section, such as conical, square, triangular or rectangular, but in one embodiment the arms  120  are generally formed to be tubular in shape. Each arm  120  can also include additional sections  122  affixed to the arm  120  at any point along the arm  120 , with each section  122  being formed similarly to the arm  120 . 
         [0037]    Each arm  120  is connected to one side surface  106  of the platform  102  by a pivot  124 , which can take a number of various forms, but in one embodiment is formed of a pillow block  126  secured to the side surface  106  and a clevis bracket  128  attached to the arm  120 . The bracket  128  is rotatably secured to the pillow block  126  by a pin  130  engaged with the pillow block  126  and the clevis bracket  128 . 
         [0038]    The clevis bracket  128  on each arm  120  forms a part of a connecting frame  132  affixed to the arm  120  adjacent the clevis bracket  128 . The connecting frame  132  transmits force from the floating arm  120  to the hydraulic cylinders  138 . The frame  132  includes an arm portion  133  that is attached directly to the arm  120 , and a connecting portion  134  that extends upwardly from the arm portion  133 . The frame  132  is formed similarly to the platform  102  and the arm  120  of a metal to be watertight. The connecting portion  134  of the frame  132  is attached to a cylinder rod  136  of a hydraulic cylinder  138  via a clevis bracket  128 . The rod  136  includes a piston  137  ( FIGS. 15A-15C ) disposed within the cylinder  138  and sealing engaged with, but slidable with respect to the interior surface of the cylinder  138 . In one embodiment, the piston  137  is disposed at the center of the cylinder  138  when the arm  120  is in the neutral position to maximize the amount of space and fluid that can be displaced by the piston  137  as it moves in either direction within the cylinder  138 . The rod  136  and cylinder  138  extends from the frame  132  to a support  140  disposed on the top surface  104  of the platform  102 . Alternatively, the position of the cylinder  138  could be reversed, with the rod  136  connected to the support  140  and the cylinder  138  connected to the frame  132 . Alternatively, each arm  120  can be connected to more than one cylinder  138 , or multiple arms  120  can be connected to a single cylinder  138 . 
         [0039]    The rod  136  and the cylinder  138  are each affixed to the frame  132  and the support  140 , or vice versa, utilizing clevis brackets  142  disposed on the connecting portion  134  of the frame  132  and the support  140 , and tangs  144  located on the rod  136  and the cylinder  138 , which are secured to one another utilizing pins  146 , as best shown in  FIG. 5 . In this configuration, the rod  136  and cylinder  138  are able to pivot with respect to the frame  132  and support  140 , as the arm  120  and frame  132  are pivoted with respect to the platform  102  by the interaction of the arm  120  with the waves on the body of water. This is best illustrated in  FIGS. 7-9  where the pivoting of the rod  136  and cylinder  138  with respect to the frame  132  and support  140  as the arm  120  pivots with respect to the platform  102  between lower, neutral an upper positions of the arm  120 . 
         [0040]    Referring now to  FIGS. 3 ,  14  and  15 A- 15 C, within the platform  102  are disposed a number of hydraulic motors  190  that are operably connected to electric generators  145 , also located within the platform  102 . The electric generators  145  are driven by the output of the hydraulic motors  190  through a suitable power transmission device  146 , and the output from the generators  145  can be transmitted via any suitable means to a location separate from the platform  102  for use in a power grid or power station, or as an electrical supply for an offshore facility such as a data center or oil rig. 
         [0041]    To operate the hydraulic motors  190 , within the platform  102 , each motor  190  has an inlet  148  and an outlet  180  connected to a hydraulic system  152 , to which is also connected each of the cylinders  138 . The hydraulic system  152  includes a high pressure manifold  154 , and a low pressure manifold  156  connected to the high pressure manifold  154  and to a fluid reservoir  158 . 
         [0042]    To connect the cylinders  138  to the hydraulic system  152 , each cylinder  138  includes a rod end port  160  and a cap end port  162  disposed at opposed ends of the cylinder  138 . Each port  160 ,  162  is connected to a three-way valve  164  that can direct fluid into or out of the port  160 ,  162  to or from a conduit  166 ,  167  connecting the manifolds  156  and  154 , or from the port  160 ,  162  to a conduit  168  connected to the reservoir  158 . A hydraulic pump  169  is connected to the conduit  168  between the reservoir  158  and the low pressure manifold  156  to maintain proper levels of fluid in the system  152 . 
         [0043]    The conduits  166 ,  167  associated with each cylinder  138  and extending between the manifolds  156  and  154  each include a low pressure check valve  170  and a high pressure check valve  171  disposed in the conduits  166 , 167  on opposite sides of the connection point of the three way valve  164  to the conduit  166 . The location and configuration of the valve  170  in each conduit  166 ,  167  allows low pressure fluid to flow from the low pressure manifold  156  to the cylinder  138 , but prevents high pressure fluid from entering the low pressure manifold  156 . Conversely, the location and configuration of the valve  171  in each conduit  166 ,  167  enables high pressure fluid from the cylinder  138  to enter the high pressure manifold  154 , but prevents the flow of high pressure fluid from the high pressure manifold  154  into the low pressure manifold  156 . 
         [0044]    The high pressure manifold  154  is connected to the hydraulic motors  190  via a conduit  172  that is operably connected to the fluid input control  174  for each of the motors  190 . The conduit  172  includes a control valve  176  located immediately upstream from each fluid input  174  which are operably connected to a flow meter  178  disposed adjacent the high pressure manifold  154 . The flow meter  178 , communicating with the fluid input control  174 , can regulate the volume of fluid passing into each of the motors  190  independently of one another, in part depending upon the total volume of fluid in the system  152 . 
         [0045]    After the high pressure fluid from the manifold  154  has been utilized by the motors  190 , the now-depressurized fluid passes via a fluid outlet  180  on each motor  190  into a conduit  182  that is connected to the low pressure manifold  156 . The conduit  182  includes a check valve  184  disposed adjacent each outlet  180  to prevent the fluid from entering the motor  190  through the outlet  180 . Additionally, the conduit  182  includes a filter  186  located upstream of the low pressure manifold  156  to filter the fluid prior to entering the low pressure manifold  156 . 
         [0046]    Referring now to FIGS.  7  and  15 A- 15 C, when the arm  120  is disposed in the neutral position ( FIG. 15A ), and when the arms  120  are not interacting with the waves, the piston  137  in the cylinder  138  is stationary and no fluid is directed through the system  152 . When the arm  120  moves downwardly to the lower position ( FIG. 15B ) as a result of the interaction of the arm  120  with a trough of a wave, the rod  136  is extended out of the cylinder  138 , consequently drawing the piston  137  towards the port  160 . The movement of the piston  137  in this direction compresses the fluid present in the cylinder  138  between the piston  137  and the end of the cylinder  138  through which the rod  136  extends to direct the high pressure fluid out of the cylinder  138  through the port  160 . Upon exiting the port  160 , the fluid enters the valve  164  and is directed into the conduit  166 . In the conduit  166 , the high pressure fluid is prevented from entering the low pressure manifold  156  due to the check valve  170 , which is maintained closed as a result of the pressure exerted on the check valve  170  by the high pressure fluid. However, the check valve  171  is opened as a result of the high pressure fluid acting on it, such that the high pressure fluid can flow along the conduit  166  into the high pressure manifold  154 . From the high pressure manifold  154 , the high pressure fluid can be directed along the conduit  172  to the hydraulic motors  190  under the direction of the flow meter  178 , as described previously. 
         [0047]    Simultaneously, due to the low pressure created in the cylinder  138  between the piston  137  and the end of the cylinder  138  opposite the rod  136 , low pressure fluid from the low pressure manifold  156  is drawn through the check valve  170  into the conduit  167 , and through the valve  164  and port  162  into the cylinder  138 . However, the bias of the check valve  171  is sufficient to prevent the valve  171  from being opened by the low pressure fluid, such that the valve  171  prevents the low pressure fluid from entering the high pressure manifold  154 . The fluid exiting the low pressure manifold  156  is subsequently replenished from conduit  182  carrying the de-pressurized fluid from the motors  190 . 
         [0048]    When the arm  120  is acted upon by a wave to pivot the arm  120  upwardly with regard to the platform  102  ( FIG. 15C ), the system  152  operates in reverse, where the rod  136  is urged into the cylinder  138 . This, in turn compresses the fluid in the cylinder  138  between the piston  137  and the closed end of the cylinder  138  opposite the rod  136 . The pressurized fluid simultaneously exits the cylinder  138  through the port  162  and is directed through the valve  164  to the conduit  167 . In the conduit  167 , the fluid is prevented from passing into the low pressure manifold  156  by the low pressure check valve  170 , but can pass into the high pressure manifold  154  though the valve  171 . 
         [0049]    Again, due to the low pressure created in the cylinder  138  between the piston  137  and the end of the cylinder  138  through which the rod  136  extends, low pressure fluid from the low pressure manifold  156  is drawn through the check valve  170  into the conduit  166 , and through the valve  164  and port  160  into the cylinder  138 . However, the bias of the check valve  171  is sufficient to prevent the valve  171  from being opened by the low pressure fluid, such that the valve  171  prevents the low pressure fluid from entering the high pressure manifold  154 . The fluid exiting the low pressure manifold  156  is subsequently replenished from conduit  182  carrying the de-pressurized fluid from the motors  190 . 
         [0050]    In this manner, regardless of the direction of motion of the arm  120  in response to the interaction of the arm  120  with a wave, the system  152  operates to generate high pressure fluid flow that can be directed through the hydraulic motors  190 . Further, as a result of the placement of the three way valves  164  adjacent each of the ports  160 ,  162 , when an arm  120  is to be taken out of service, etc. for repair or maintenance, the valve  164  can be operated to direct the flow of fluid out of the cylinder  138  to the reservoir  158 , bypassing the motors  190 . Thus, any number of the arms  120  can be disconnected from the motors  190 , while allowing the remainder to continue to operate the motors  190  via the hydraulic system  152 . 
         [0051]    Looking now at  FIGS. 2 ,  4 ,  6 ,  8  and  10 , in a second embodiment of the invention, the connecting portion  134 ′ of the frame  132 ′ extends over the top surface  104 ′ of the platform  102 ′ such that the cylinder  138 ′ is oriented generally vertically and is connected directly to the top surface  104 ′ of the platform  102 ′ by a clevis bracket  142 ′ disposed on the cylinder  138 ′ and pivotally engaged with a clevis bracket  142 ′ disposed on the top surface  104 ′ by a pin  146 ′. 
         [0052]    Referring now to  FIGS. 16A-16D , various configurations for a power generation system  100  including a number of platforms  102  positioned in an array  1000  on the body of water. The platforms  102  have various cross-sectional shapes, with varying numbers of arms  120  extending outwardly from the sides  106  of the platforms  102  for interaction with the waves on the surface of the body of water. In each array  1000 , an electric transformer station  2000  is disposed near the platforms  102  and is in operable connection with the electric generators  145  on each of the platforms  102  to capture and direct the electric energy created on each of the platforms  102 . The preferred embodiment in  FIG. 16D  has a circular cross-sectional shape with additional tubular sections  122  affixed to the arms  120 . 
         [0053]    In alternative embodiments of the power generation system  100  of the present invention, the platforms(s)  102  can include a monitoring system  3000  that is operably connected to the hydraulic system  152  of the platform  102 . The monitoring system  3000  is configured to determine the present operating condition of the various components of the platform  102  and selectively control the operation of the platform  102 . For example, should any components of the hydraulic system  152  fail, e.g., a fluid leak, from the hydraulic system  152 , or if a component of the system  100  becomes damaged, e.g., one of the arms  120  or the platform  102 , the monitoring flow meter  178  bypasses the damaged component from remainder of the system  152 . The monitoring system  3000  can also be configured to send out a signal, such as a wireless signal, via a transmitter to a suitable device, such as a computer or phone, among others, to indicate to an individual the presence of a failure on the platform  102  in order to enable the individual to initiate a repair. The monitoring system  3000  may also include a receiver to receive instructions, such as via a wireless signal, concerning the operation of the power generation system  100 . 
         [0054]    In addition, the monitoring system  3000  can selectively control the connection of one or more of the arms  120  to the hydraulic system  152  depending upon the wave conditions about the platform  102 . For example, when performing maintenance tasks, the monitoring system  3000  can disconnect a number of the arms  120  and hydraulic motors  190  from the hydraulic system  152  by operating the three way valves  164 . Alternatively, the monitoring system  3000  can reconnect the arms  120  and/or motors  190  to the hydraulic system. 
         [0055]    Various other embodiments of the present invention are contemplated as being within the scope of the filed claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.