Submerged water current turbines installed on a deck

Abstract

A support structure for a flowing-water drivable turbine system having at least one generally horizontal deck of streamlined cross-section and at least one turbine assembly mounted thereon for operational co-operation with a flow of water in which the deck and turbine assembly is submerged above a sub-aquatic bed, an obstruction being situated between the sub-aquatic bed and deck causing most of the water flow relative to the deck to rise and accelerate over the deck upper surface through the drivable turbine assembly.

1 - 14 . (canceled) 
     
     
         15 . A submerged water current turbine installation comprising: a flowing-water drivable turbine system and a support structure for supporting the flowing-water drivable turbine system at a selected position below a water surface and above a sub-aquatic bed, the support structure including a plurality of legs fixed to the sub-aquatic bed, a generally horizontal deck coupled to the plurality of legs, the deck having upper and lower surfaces, the deck having an asymmetrical streamlined cross-section, the flowing-water drivable turbine system being fixed to the upper surface of the deck, and an obstruction arranged between the lower surface of the deck and the sub-aquatic bed causing most of the water flow relative to the deck to rise and accelerate over the deck upper surface. 
     
     
         16 . The submerged water current turbine installation of  claim 15 , further comprising displacing means for displacing the deck between an operational position wherein the water current turbine installation is below the water surface and a maintenance position wherein the water current turbine installation is above the water surface. 
     
     
         17 . The submerged water current turbine installation of  claim 16 , wherein the deck is buoyant and the displacing means comprises extendable tension members connecting the deck to the plurality of legs. 
     
     
         18 . The submerged water current turbine installation of  claim 17 , wherein the asymmetric streamlined cross-section of the deck is sufficient to provide by virtue of passing water flow an upward lifting force on the tension members. 
     
     
         19 . The submerged water current turbine installation of  claim 16 , wherein the displacing means comprises vertically movable lifting sleeves connecting the deck to the plurality of legs. 
     
     
         20 . The submerged water current turbine installation of  claim 19 , wherein the asymmetric streamlined cross-section of the deck is sufficient to provide by virtue of passing water flow a downward force on the plurality of legs. 
     
     
         21 . The submerged water current turbine installation of  claim 15 , wherein each of the upper and lower surfaces of the deck are generally rectangular. 
     
     
         22 . The submerged water current turbine installation of  claim 15 , further comprising a second deck vertically spaced from, and arranged generally parallel to, the first deck. 
     
     
         23 . The submerged water current turbine installation of  claim 22 , wherein the flowing-water drivable turbine system is fixed between the first and second decks. 
     
     
         24 . The submerged water current turbine installation of  claim 22 , wherein the flowing-water drivable turbine system is fixed in horizontal alignment with the second deck. 
     
     
         25 . The submerged water current turbine installation of  claim 22 , wherein the second deck is smaller than the first deck. 
     
     
         26 . The submerged water current turbine installation of  claim 15 , wherein the obstruction substantially blocks space below the deck when the deck is located on the operational position, the space below the deck remaining sufficient to permit any turbulent boundary layer forming adjacent to the sub-aquatic bed to pass below the deck. 
     
     
         27 . A water current turbine installation for generating power from a column of flowing water, the installation comprising:
 an elongate deck of streamlined cross section having an upper surface and a lower surface;   at east one turbine assembly upstanding from the upper surface of the deck;   a support arrangement for the deck permanently positioned on a bed defining a bottom of said column of flowing water, the support arrangement supporting the deck at a lowermost position providing a space between the bed and the deck lower surface;   means for vertically displacing the deck with respect to the support arrangement between the lowermost position and a raised position in which each turbine assembly is accessible from an upper surface of the water column; and   means for partially blocking said space so that the flowing water in the column is caused to accelerate over the upper surface of the deck.   
     
     
         28 . The installation of  claim 27  wherein the means for partially blocking said space establishes a water flow path beneath the deck lower surface that reduces turbulence in the water flowing over the upper surface of the deck. 
     
     
         29 . The installation of  claim 27  wherein the elongate deck includes leading and trailing edges having narrow rounded surfaces. 
     
     
         30 . The installation of  claim 27  wherein the upper and lower surfaces of the deck have curvatures that differ from each other. 
     
     
         31 . The installation of  claim 30  wherein the upper surface of the deck has a greater convexity than the lower surface. 
     
     
         32 . The installation of  claim 31  wherein the lower surface of the deck is substantially planar or concave. 
     
     
         33 . The installation of  claim 27  further comprising at least one additional deck of streamline cross section spaced above said elongate deck. 
     
     
         34 . The installation of  claim 33  wherein each additional deck is of an elongated planform having rounded elongate edge regions.