Abstract:
A novel conduit design is disclosed. The conduit includes a cylindrical body having defined therein a first aperture and a second aperture, wherein the first aperture is designed to receive a shaft of a turbine and the second aperture is sufficiently large to facilitate ingress or egress of a probe through the second aperture, and wherein the second aperture is located a distance away from the first aperture such that when a turbine is disposed through the first aperture, an entry by a probe into the cylindrical body through the second aperture is not prevented by presence of the turbine.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to pipes useful for harnessing hydrokinetic energy. More particularly, the present invention relates to novel designs and assembly methods for pipes, which allow for easy inspection and installation of turbines useful for harnessing hydrokinetic energy. 
       BACKGROUND OF THE INVENTION 
       [0002]    Hydrokinetic energy refers to the generation of energy from the flow, current or velocity of water. This type of energy is different from hydroenergy, which traditionally refers to power generated using dams (impoundment or run-of-river). Since hydrokinetic energy relies on the velocity of water, these energy systems can be placed into sources of flowing water with minimal infrastructure or environmental impacts. As a result, hydrokinetic power is considered cutting-edge waterpower. 
         [0003]    To harness hydrokinetic energy, typically turbines operate in rivers, oceans and tidal settings. By way of example, in rivers, turbines can be installed for applications that harness energy from such settings as in-stream, free-flow, open-river or hydrokinetic run-of-river. As other examples, in ocean and tidal settings, turbines harness ocean power and tidal power, respectively. 
         [0004]    These turbines may be loaded onto a barge, which is well equipped with cranes to facilitate the raising and lowering of individual turbines and power generating units that accompany them. In other examples, these turbines may be integrated into an in-pipe hydro-electric power generator. 
         [0005]    Unfortunately, whether a barge or an in-pipe hydro-electric power generator is used, the current designs and methods of harnessing hydrokinetic energy suffer from drawbacks. By way of example, during operation, the turbine typically undergoes fouling and clogging by bio-growth, debris, sediment, and ice that is dragged by the flowing water. As expected, this results in reduced flow through the turbine, increased head losses and hydrostatic forces. To prevent or minimize such undesired consequences maintenance of the turbine is periodically conducted. The frequency of maintenance depends on, among other things, the amount of fouling and clogging agents present in the water flowing through the turbine. Regardless of the number of times maintenance is carried out, each time maintenance is deemed necessary, a significantly heavy turbine, i.e., typically weighing between about 0.5 tons and about 10 tons, is lifted up and removed from the water flow path. In most instances, the turbine is transported to a maintenance facility. Maintenance, therefore, not only represents a time-consuming and arduous task, but also requires extensive equipment (e.g., cranes and trailers). Furthermore, it is important to be very careful when moving such heavy equipment that the pipe or some portion of the turbine is not damaged because repair or permanent damage translates into additional costs. 
         [0006]    What are therefore needed are designs and assembly methods for pipes, which allow for easy inspection and maintenance of turbines useful for harnessing hydrokinetic energy. 
       SUMMARY OF THE INVENTION 
       [0007]    In view of the foregoing, this invention provides designs and assembly methods for pipes, which allow for easy inspection and maintenance of turbines useful for harnessing hydrokinetic energy. 
         [0008]    In one aspect, the present invention provides a conduit. The conduit includes a cylindrical body having defined therein a first aperture and a second aperture, wherein the first aperture is designed to receive a shaft of a turbine and the second aperture is sufficiently large to facilitate ingress or egress of a probe through the second aperture, and wherein the second aperture is located a distance away from the first aperture such that when the shaft of the turbine is disposed through the first aperture, an entry by a probe into the cylindrical body through the second aperture is not prevented by presence of the turbine. The second aperture is defined by an opening in a cylindrical body perpendicularly disposed on the conduit and protruding outward and the opening is a flanged opening. Inventive conduits of the present invention may further include a generator and a coupling, wherein the coupling serves as an interface between the shaft of the turbine and a shaft of the generator. 
         [0009]    In accordance with one embodiment of the present invention, the first aperture has a diameter that is between about 2 inches feet and about 6 inches. In preferred embodiments of the present invention, however, the diameter is between about 2 inches and about 4 inches. Similarly, in one embodiment of the present invention, the second aperture has a diameter that is between about 2 feet and about 3.5 feet, but preferably has a diameter that is between about 2.5 feet and about 3.5 feet. The distance between the first aperture and the second aperture may be between about 2 feet and about 60 feet, but is preferably between about 4 feet and about 10 feet. The cylindrical body may have a diameter that is between about 2.5 feet and about 10 feet. 
         [0010]    The turbine may be any one of spherical turbine, helical turbine, troposkein turbine, and circular-, square- or rectangular-shaped turbine. The probe may be a human, a motor-driven object or a remotely controlled object. In preferred embodiments, inventive conduits further include a frame assembly that is mounted on the conduit and disposed above the first aperture, and the frame assembly is designed to secure a generator above the turbine when the turbine is disposed through the first aperture. In certain preferred embodiments, the inventive conduits include a cover which covers the second aperture. The first aperture may be located upstream from the second aperture, but is preferably located located downstream from the second aperture. 
         [0011]    In one embodiment of the present invention, inventive conduits include a first block, a first seal, and a first bearing that are disposed near first aperture to secure the turbine at a first location that is adjacent the first aperture. In certain embodiments of the present invention, inventive conduits also include a third aperture disposed opposite to the first aperture such that the shaft of the turbine passes through both the first aperture and the third aperture. Inventive conduits may further include a second seal, a second bearing and a second block to secure the turbine at a second location that is adjacent the third aperture. 
         [0012]    In another aspect, the present invention provides a method of assembling a conduit capable of generating power. The method includes: (1) obtaining a cylindrical body having defined therein a first aperture and a second aperture; (2) introducing a turbine through the second aperture; and (3) displacing the turbine inside the conduit towards the first aperture such that a central axis of the turbine, which is capable of receiving a shaft, aligns with the first aperture. 
         [0013]    In accordance with one embodiment of the present invention, in the above-mentioned step of obtaining, the second aperture is located on the cylindrical body a distance away from the first aperture such that an entry by a probe into the cylindrical body through the second aperture is not prevented by presence of the turbine. 
         [0014]    Inventive methods may further include a step of covering the second aperture with a cover (e.g., blind flange). Furthermore, the step of introducing may include disposing a turbine that is any one of spherical turbine, helical turbine, troposkein turbine, and circular-, square- or rectangular-shaped turbine. 
         [0015]    In preferred embodiments, inventive methods further include installing a frame assembly that is mounted on the conduit and disposed above the first aperture. This embodiment may further still include securing a generator using the frame assembly above the turbine. 
         [0016]    The cylindrical body, implemented in the inventive methods, may have defined therein a third aperture and preferred embodiments of the inventive methods may include: (1) passing the shaft of the turbine through the first aperture and the third aperture; and (2) securing the shaft of the turbine near the first and the third apertures to prevent substantial lateral displacement of the turbine. 
         [0017]    The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following descriptions of specific embodiments when read in connection with the accompanying figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1A  shows a conduit, according to one embodiment of the present invention, having defined therein a first aperture and a second aperture. 
           [0019]      FIG. 1B  shows a conduit, according to an alternative embodiment of the present invention, having defined therein three apertures and including a flanged inlet and a flanged outlet. 
           [0020]      FIG. 2A  shows a side view of an in-conduit hydroelectric power generator, according to one embodiment of the present invention, which has incorporated into it the conduit of  FIG. 1B . 
           [0021]      FIG. 2B  shows a perspective view of the in-conduit hydroelectric power generator shown in  FIG. 2A . 
           [0022]      FIG. 2C  shows an inline view of a flow path of water inside the in-conduit hydroelectric power generator shown in  FIG. 2A . 
           [0023]      FIG. 2D  shows a top view of the in-conduit hydroelectric power generator shown in  FIG. 2A . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0024]    In the following description numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without limitation to some or all of these specific details. In other instances, well known process steps have not been described in detail in order to not unnecessarily obscure the invention. 
         [0025]      FIG. 1A  shows a conduit  50 , according to one embodiment of the present invention, which includes a cylindrical body  102  have defined therein two apertures, i.e., a first aperture  104  and a second aperture  106 . The conduit is designed to provide a flow path for water through an inlet  52  and an outlet  54 . Conduit  50  is made from any rigid material which is capable of withstanding water of turbulent flow profile. Preferably, however, conduit  50  is made from steel, concrete, plastic, high density polyethylene, or any composite material capable of sustaining internal pressure and flow in the cylindrical body  102 . Cylindrical body  102  may have a diameter that is between about 2.5 feet and about 10 feet. In preferred embodiments, however, inventive conduits have a diameter that is between about 3 feet and about 8 feet. 
         [0026]    First aperture  104  may have a diameter large enough to receive a shaft of a turbine, which is ultimately inside conduit  50 , as explained with respect to  FIGS. 2A-2D . By way of example, first aperture  104  has a diameter that is between about 2 inches and about 6 inches and preferably between about 2 inches and about 4 inches. Second aperture  106  may have a diameter that is between about 2 feet and about 3.5 feet, and is preferably between about 2.5 feet and about 3.5 feet. A probe is preferably any one of a human, a motor-driven object or a remotely controlled object. A distance between first aperture  104  and second aperture  106  may be any distance that is large enough such that the presence of a turbine inside the conduit should not prevent a probe from entering through the second aperture. If the distance is too large, then inspection and installation of the turbine, as explained below, can be a time-consuming and an arduous task. In preferred embodiments of the present invention, however, the distance between first aperture  104  and second aperture  106  is between about 2 feet and about 60 feet, and in even more preferred embodiments, the distance between first aperture  104  and second aperture  106  is between about 4 feet and about 10 feet. 
         [0027]    In accordance with one preferred embodiment of the present invention,  FIG. 1B  shows a conduit  60 , which is substantially similar to conduit  50  shown in  FIG. 1A , except conduit  60  in  FIG. 1B  includes a third aperture  124  and flanged ends  122  and  120 . Third aperture  124  is configured to align with first aperture  104  such that a shaft of a turbine disposed inside conduit  60  passes through both first and third apertures  104  and  124 , respectively. Although conduit  60  is designed to provide a flow path for water through an inlet  62  and an outlet  64  ends of conduit  60  are flanged as shown in  FIG. 1B . Flanged inlet  120  and flanged outlet  122  allow for connecting conduit  60  to other conduits, which may or may not be configured to receive a turbine. In this manner, a conduit network is created to convey water or a liquid from one point to another. 
         [0028]      FIG. 2A  shows an in-conduit hydroelectric power generator  100 , according to one embodiment of the present invention. According to this figure, a turbine  108  is installed inside a conduit  102 . Turbine  108  includes a shaft  118  having a top end and a bottom end. Top end of turbine  108  passes through a first aperture (which is shown in  FIGS. 1A and 1B ) and bottom end of turbine  108  passes through a third aperture (which is shown in  FIG. 1B ). After passing through first aperture, top end is secured thereabove using a block  140 , a seal  134  and a bearing  126 . Similarly, after passing through a third aperture, the bottom end of turbine  108  is secured therebelow using a lower block  130 , a lower seal  136  and a lower bearing  132 . 
         [0029]    A coupling  114  disposed above bearing  126  serves as an interface between shaft  118  of turbine  108  and generator shaft (not shown to simplify illustration) of a generator  110 . A generator frame  112  is attached to conduit  102  using a mounting bracket  124  and serves to secure generator  110  to conduit  102 . On conduit  102 , adjacent to generator  110  and generator frame  112 , disposed is a substantially cylindrically-shaped body  138  that protrudes outwardly from second aperture (which is shown in  FIGS. 1A and 1B ) of conduit  102 . A flanged outlet  116  is disposed above the cylindrically-shaped body, as shown in  FIG. 2A . Like  FIG. 1B ,  FIG. 2  also shows flanged inlet  120  and flanged outlet  122  which allows conduit  102  to connect to other conduits and form a conduit network, which conveys water or liquid from one point to another. More importantly, in-conduit hydroelectric power generator  100  harnesses hydro-electric power from the flowing action of water through conduit  102 . 
         [0030]      FIG. 2B  shows a perspective view of an in-conduit hydroelectric power generator  100  that is shown in  FIG. 2A .  FIG. 2C  shows clearly an inline view of flow path of water flowing through in-conduit hydroelectric power generator  100  shown in  FIG. 2A .  FIG. 2D  shows a top view of the in-conduit hydroelectric power generator  100  shown in  FIG. 2A . In other words,  FIGS. 2B ,  2 C and  2 D show from different perspectives, various components assembled and shown in  FIG. 2A . By way of example, when water flows through a flow path inside conduit  102 , as shown in  FIG. 2C , and impinges upon the blades of helical turbine  108 , shaft  118  of turbine  108  spins around a central axis, which passes along the length of shaft  118 . The spinning action of shaft  118 , in turn, causes shaft of generator  110  to spin and generate electricity. 
         [0031]    Although first, second and third apertures are not shown in  FIGS. 2A-2D  to facilitate illustration; they are configured and dimensioned as described with respect to  FIG. 1B . Turbine  108  is shown in  FIGS. 2A-2D  as having a helical design, which is explained in greater detail in U.S. patent application Ser. No. 12/384,765, filed on Apr. 7, 2009 and entitled “In-Pipe Hydro-Electric Power System and Turbine.” It is not necessary that turbine  108  have a spherical design, rather turbines of other designs, such as helical turbine, troposkein turbine, and circular-, square- or rectangular-shaped turbines, work well. 
         [0032]    Generator  110  can be any generator that is designed to work in connection with a turbine to produce power. However, in preferred embodiments of the present invention, generator is a permanent magnet three-phase generator. Coupling  114  and blocks  140  and  130  are made from a rigid material, which is preferably made from a material that facilitates a formation of a welded connection to conduit  102 . By way of example, in such preferred embodiments of the present invention, coupling consists primarily of intermeshing parts, such as two steel hubs with a more flexible component disposed between them which is capable of flexing slightly in order to compensate for shaft misalignment and transfer torque. Blocks  140  and  130  are preferably made from metal (e.g., steel). 
         [0033]    Seals  134  and  136  are made from any material that effectively seals off high pressures encountered at the bottom of third aperture and top of first aperture, respectively. In preferred embodiments of the present invention, these seals are made from either cartridge-type face seal assemblies or radial lip seal assemblies. Bearings  126  and  132  are made from any material that reduces frictional forces acting on shaft  118  when it is rotating. Preferably, however, bearings  126  and  132  are made from a flanged spherical roller bearing assembly. 
         [0034]    The present invention also provides a method of assembling an in-conduit hydroelectric power generator  100  shown in  FIGS. 2A-2D . In a preferred embodiment, such inventive processes begin by obtaining a cylindrical body, e.g., such as the conduit shown either in  FIGS. 1A and 1B , that has defined therein a first aperture and a second aperture. Although such a body can be obtained at a manufacturing site, the present invention allows that such a body and assembly as described herein can be carried out in situ, i.e., at the site of in-conduit network which is designed to harness hydroelectric power. By carrying out the steps of assembling the in-conduit hydroelectric power generator in situ, the present invention circumvents the arduous and time consuming task of assembling such a generator offsite and also obviates the high costs that might be associated with such an assembly process. 
         [0035]    Although the present invention contemplates introducing a turbine (e.g., turbine  108  as shown in  FIGS. 2A-2D ) inside a conduit (e.g., conduit  102  of  FIGS. 2A-2D ) through an inlet or outlet (e.g., flanged inlet  120  or flanged outlet  122 ), it is preferable to introduce the turbine, without the shaft, through a second aperture (e.g., aperture  106  of  FIGS. 1A and 1B ). Next, the turbine, without the shaft, is aligned such that a central axis of the turbine (where a turbine shaft, such as shaft  118  shown in  FIGS. 2A ,  2 C and  2 D, is ultimately disposed) passes through the first aperture (e.g., aperture  104  of  FIGS. 1A and 1B ) and if present, third aperture (e.g., third aperture  124  shown in  FIG. 1B ). A shaft is then disposed to pass through the first aperture and, if present, the third aperture such that the shaft passes through the central axis of the turbine. In the mating position of the turbine and the turbine shaft, the turbine is secured using bearings, seals and blocks which are positioned behind the first and the third apertures as shown in  FIGS. 2A-2D . In such a secured configuration, the turbine assembly is capable of rotational displacement about the central axis of the turbine or turbine shaft, but not capable of lateral displacement. 
         [0036]    In one preferred embodiment, the inventive processes include covering the second aperture with a cover. By way of example, the cover is a blind flange that is bolted on to  116  to seal it. During installation, the cover is removed to provide a point of entry inside the conduit as described above Similarly, during an onsite inspection, the same cover is removed to provide access to a probe to inspect the turbine (e.g., spherical turbine, helical turbine, troposkein turbine, and circular-, square- or rectangular-shaped turbines) that is installed inside the conduit. 
         [0037]    Inventive assembly processes preferably include steps for providing a generator (e.g., generator  110  above the turbine. By way of example, providing a generator begins with installing a frame assembly (e.g., frame assembly  112  shown in  FIGS. 2A-2D ). In this step, the frame assembly is mounted on a conduit and disposed above the first aperture as shown in  FIGS. 2A-2D . Specifically, the frame assembly is bolted on frame brackets (e.g., frame brackets  124  as shown in  FIG. 2B ) that are, in turn, preferably attached to the conduit by a welded connection. 
         [0038]    Under operation, the liquid or water impinging upon the blades of the turbine causes a turbine shaft to rotate about its axis. A coupling (e.g., coupling  114  shown in  FIG. 2A ) connection between the turbine shaft (e.g., shaft  118  of  FIG. 2A ) and shaft of generator (e.g., generator  110  of  FIG. 2A ) induces the generator shaft to also rotate, producing electricity. The present invention, therefore, provides systems and processes for harnessing energy from the flowing action of water through a conduit. 
         [0039]    More importantly, inventive systems and processes which include the provision of a second aperture (e.g., denoted by reference numeral  106  in  FIGS. 1A and 1B  and that may be covered by flanged outlet) preferably allows for both installation and inspection of the turbine inside the conduit. More importantly, provision of the second aperture allows for both installation and inspection of a turbine assembly. 
         [0040]    Although illustrative embodiments of this invention have been shown and described, other modifications, changes, and substitutions are intended. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the disclosure, as set forth in the following claims