Patents by Inventor Nagan Srinivasan

Nagan Srinivasan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10612523
    Abstract: An offshore monopile wind turbine having an elongate monopile column formed of a lower section, an intermediate section, and an upper section, secured together by connecting collars. A triangular support structure having a triangular three-sided bottom portion extends horizontally outward from one side of the lower connecting collar includes a first pair of lower horizontal tubular beams diverging outwardly with outer ends welded to a respective vertical skirt pile sleeve, a third tubular beam extending between the skirt pile sleeves. An upper pair of tubular beams diverge outwardly and downwardly from the upper connecting collar and are welded to a respective skirt pile sleeve. A horizontal wind turbine platform and elongate wind turbine tower secured to the top end of the elongate upper section of the monopile column includes a nacelle at the top of the turbine tower includes a rotor with three rotor blades.
    Type: Grant
    Filed: June 1, 2019
    Date of Patent: April 7, 2020
    Inventor: Nagan Srinivasan
  • Patent number: 10337499
    Abstract: A self-installing offshore column stabilized semi-submersible platform has at least one vertical buoyant ballastable column, a telescoping keel tank or stiffened damper plate movably connected with the vertical column that extends and retracts relative to a lower end thereof, and a tilt and telescoping wind turbine tower assembly pivotally coupled to an upper end of the vertical column telescopes and reciprocates relative thereto between a horizontal retracted position and an axially extended vertical position. A wind turbine with blades is coupled to a top portion of the upper section of the tower assembly. The relative position and weight of the keel tank or damper plate is selectively adjustable to raise or lower the center of gravity of the entire mass of the semi-submersible platform including the wind turbine and tower assembly with respect to the center of buoyancy of the platform.
    Type: Grant
    Filed: April 23, 2018
    Date of Patent: July 2, 2019
    Inventor: Nagan Srinivasan
  • Patent number: 10087915
    Abstract: A self-installing offshore column stabilized semi-submersible platform has at least one vertical buoyant ballastable column, a telescoping keel tank or stiffened damper plate movably connected with the vertical column that extends and retracts relative to a lower end thereof, and a non-collapsible turbine tower or a tilt and telescoping tower coupled to an upper end of the vertical column that telescopes and reciprocates relative thereto between a horizontal retracted position and an axially extended vertical position. A wind turbine with blades is coupled to a top portion of the tower assembly. The relative position and weight of the keel tank or damper plate is selectively adjustable to raise or lower the center of gravity of the entire mass of the semi-submersible platform including the wind turbine and tower assembly with respect to the center of buoyancy of the platform.
    Type: Grant
    Filed: May 20, 2014
    Date of Patent: October 2, 2018
    Inventor: Nagan Srinivasan
  • Patent number: 9476410
    Abstract: An offshore floating platform having at least one buoyant column with an upper end extending above a sea surface, a lower end submerged below the sea surface, and at least one keel tank disposed at the lower end. A deck is supported at the upper end the column. An ocean thermal energy conversion (OTEC) system is integrated with the platform in which heat is extracted from warm sea surface waters to vaporize a liquid working fluid and heat is rejected to cold water from lower depths of the sea to condense the vaporized working fluid. At least one turbine and power generator is disposed on the deck, at least one evaporator is disposed on the platform beneath the deck, and at least one condenser is disposed on the seabed or platform or keel tank a distance beneath the evaporator. A desalination system may also be combined and incorporated with the OTEC system.
    Type: Grant
    Filed: May 3, 2010
    Date of Patent: October 25, 2016
    Inventor: Nagan Srinivasan
  • Patent number: 8764346
    Abstract: A tension-based tension leg platform (TBTLP) for use in ultra deepwater applications to support dry-tree oil and gas production utilizes a tension base or artificial seabed that simplifies tendon design at deepwater locations in harsh environment and has a truss pontoon structure that reduces vertical and horizontal wave loadings. The platform may include a riser support tower that makes production risers feasible in 8,000 ft water depths without riser pretension to the hull and reduces or eliminates vortex induced vibration problems.
    Type: Grant
    Filed: June 7, 2011
    Date of Patent: July 1, 2014
    Inventor: Nagan Srinivasan
  • Patent number: 8511246
    Abstract: An offshore floating production, storage, and off-loading vessel has a hull of generally cylindrical or polygonal configuration surrounding a central double tapered conical moon pool and contains water ballast and oil and/or liquefied gas storage compartments. An adjustable water ballast system induces heave, roll, pitch and surge motions of the vessel to dynamically position and maneuver the vessel. The moon pool shape and other devices on the vessel provide added virtual mass for increasing the natural period of the roll and heave modes, reducing dynamic amplification and resonance due to waves and vessel motion, and facilitate maneuvering the vessel. A disconnectable turret buoy at the bottom of the moon pool connects risers and mooring lines.
    Type: Grant
    Filed: June 13, 2011
    Date of Patent: August 20, 2013
    Inventor: Nagan Srinivasan
  • Publication number: 20120298027
    Abstract: An offshore floating production, storage, and off-loading vessel has a hull of generally cylindrical or polygonal configuration surrounding a central double tapered conical moon pool and contains water ballast and oil and/or liquefied gas storage compartments. An adjustable water ballast system induces heave, roll, pitch and surge motions of the vessel to dynamically position and maneuver the vessel. The moon pool shape and other devices on the vessel provide added virtual mass for increasing the natural period of the roll and heave modes, reducing dynamic amplification and resonance due to waves and vessel motion, and facilitate maneuvering the vessel. A disconnectable turret buoy at the bottom of the moon pool connects risers and mooring lines.
    Type: Application
    Filed: June 13, 2011
    Publication date: November 29, 2012
    Inventor: Nagan Srinivasan
  • Patent number: 7963241
    Abstract: Column-stabilized floating offshore platform structures (10) having spaced apart buoyant main vertical columns (11) joined at lower ends by horizontal lower truss members (13) in a pin connection and joined at upper ends by a buoyant deck mount structure (14), and/or by horizontal truss members, to form a moment connection. A buoyant keel tank (15) having a central moon pool (15A) can be retracted and extended relative to the main columns between a retracted transport mode and an extended operating mode. Ballast of the columns and keel tank can be adjusted to raise or lower the center of gravity of the structure with respect to its center of buoyancy to stabilize the structure and compensate for variable or fixed loads, deck payloads, environmental conditions, and operational and installation stages. A three-sided deck mount allows on-site float-over deck installation.
    Type: Grant
    Filed: February 19, 2009
    Date of Patent: June 21, 2011
    Inventor: Nagan Srinivasan
  • Patent number: 7958835
    Abstract: An offshore floating production, storage, and off-loading vessel has a hull of generally cylindrical or polygonal configuration surrounding a central double tapered conical moon pool and contains water ballast and oil and/or liquefied gas storage compartments. The exterior side walls of the polygonal hull have flat surfaces and sharp corners to cut ice sheets, resist and break ice, and move ice pressure ridges away from the structure. An adjustable water ballast system induces heave, roll, pitch and surge motions of the vessel to dynamically position and maneuver the vessel to accomplish ice cutting, breaking and moving operations. The moon pool shape and other devices on the vessel provide added virtual mass for increasing the natural period of the roll and heave modes, reducing dynamic amplification and resonance due to waves and vessel motion, and facilitate maneuvering the vessel. A disconnectable turret buoy at the bottom of the moon pool connects risers and mooring lines.
    Type: Grant
    Filed: January 2, 2008
    Date of Patent: June 14, 2011
    Inventor: Nagan Srinivasan
  • Publication number: 20110120126
    Abstract: An offshore floating platform having at least one buoyant column with an upper end extending above a sea surface, a lower end submerged below the sea surface, and at least one keel tank disposed at the lower end. A deck is supported at the upper end the column. An ocean thermal energy conversion (OTEC) system is integrated with the platform in which heat is extracted from warm sea surface waters to vaporize a liquid working fluid and heat is rejected to cold water from lower depths of the sea to condense the vaporized working fluid. At least one turbine and power generator is disposed on the deck, at least one evaporator is disposed on the platform beneath the deck, and at least one condenser is disposed on the seabed or platform or keel tank a distance beneath the evaporator.
    Type: Application
    Filed: May 3, 2010
    Publication date: May 26, 2011
    Inventor: Nagan Srinivasan
  • Publication number: 20090205554
    Abstract: Column-stabilized floating offshore platform structures (10) having spaced apart buoyant main vertical columns (11) joined at lower ends by horizontal lower truss members (13) in a pin connection and joined at upper ends by a buoyant deck mount structure (14), and/or by horizontal truss members, to form a moment connection. A buoyant keel tank (15) having a central moon pool (15A) can be retracted and extended relative to the main columns between a retracted transport mode and an extended operating mode. Ballast of the columns and keel tank can be adjusted to raise or lower the center of gravity of the structure with respect to its center of buoyancy to stabilize the structure and compensate for variable or fixed loads, deck payloads, environmental conditions, and operational and installation stages. A three-sided deck mount allows on-site float-over deck installation.
    Type: Application
    Filed: February 19, 2009
    Publication date: August 20, 2009
    Inventor: Nagan Srinivasan
  • Publication number: 20090126616
    Abstract: An offshore floating production, storage, and off-loading vessel has a monolithic non ship-shaped hull of polygonal configuration surrounding a central double tapered conical moon pool and contains water ballast and oil storage compartments. The exterior side walls of the hull have flat surfaces and sharp corners to cut ice sheets, resist and break ice, and move ice pressure ridges away from the structure. An adjustable water ballast system induces heave, roll, pitch and surge motions of the vessel to dynamically position and maneuver the vessel to accomplish ice cutting, breaking and moving operations. The moon pool shape and other devices on the vessel provide added virtual mass capable of increasing the natural period of the roll and heave modes, reducing dynamic amplification and resonance due to waves and vessel motion, and facilitate maneuvering the vessel.
    Type: Application
    Filed: January 2, 2008
    Publication date: May 21, 2009
    Inventor: Nagan Srinivasan
  • Patent number: 6942427
    Abstract: A floating offshore fluid storage caisson platform has a large diameter vertically oriented buoyant column or caisson, or multiple caissons, defining a storage chamber, and a telescopic keel tank disposed at the bottom end thereof, and may have deck on top of the caisson to support storage, drilling and production structures, equipment, and quarters. The structure can be transported horizontally either dry on a transporting vessel or towed with its keel tank in a fully retracted position. At the field of operation, the structure initially floats horizontally.
    Type: Grant
    Filed: May 3, 2004
    Date of Patent: September 13, 2005
    Inventor: Nagan Srinivasan
  • Patent number: 6899492
    Abstract: Jacket frame floating structures comprise one or more elongate vertical support columns formed of an open cross-braced jacket formwork of tubular members interconnected together and at least one cylindrical buoyancy capsule disposed in the open framework near an upper end and at least one cylindrical second buoyancy capsule near a lower end in vertically spaced relation. The buoyancy capsule(s) may be a single, or a plurality of upper and lower capsules bundled in circumferentially spaced relation with a central opening therethrough. Alternatively, a keel tank may replace the lower capsule.
    Type: Grant
    Filed: May 5, 2004
    Date of Patent: May 31, 2005
    Inventor: Nagan Srinivasan
  • Patent number: 6761124
    Abstract: Column-stabilized floating structures having a deck and a plurality of vertical buoyant caissons bridged together in distantly spaced relation by a plurality of open frame horizontal truss pontoon members and vertical truss columns at a lower end. The buoyancy of the caissons is selectively adjusted by means of ballast control. Water is selectively pumped into or out of keel tanks at the bottom of the truss structure such that the water mass and weight is adjustably tuned to raise or lower the center of gravity of the entire mass of the floating structure relative to its center of buoyancy. By tuning and positioning the center of gravity relative to the center of buoyancy, the floating structures can be tuned according to ballast and other variable or fixed loads including the deck payloads and to compensate for different operational, environmental, and survival conditions and towing and installation stages.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: July 13, 2004
    Inventor: Nagan Srinivasan
  • Patent number: 5707178
    Abstract: An offshore platform for supporting a platform deck in deep water. A buoyant base is submerged below the water surface and is retained with base tendons to a foundation on the sea floor. The buoyant base is attachable to the mooring tendons of a tension leg vessel positioned above the buoyant base. The buoyant base can be selectively ballasted to control the tension in the base tendons. Additional buoyant bases and connecting tendons can extend the depth of the total structure beyond depths possible with conventional tension leg structure technology. Mooring lines can be connected between the buoyant base and the sea floor to limit lateral movement of the buoyant base. The buoyant base esentially creates a submerged foundation which reduces the required length of a conventional tension leg platform. The tension leg platform can be detached from the buoyant base and moved to another location.
    Type: Grant
    Filed: November 21, 1995
    Date of Patent: January 13, 1998
    Inventor: Nagan Srinivasan