Fluid turbine with moveable fluid control member

Abstract

A shrouded fluid turbine includes an impeller for generating power from a fluid stream and a shroud surrounding the impeller. The impeller and/or the shroud have a moveable member for controlling power generation in the fluid turbine. The shroud has a plurality of mixing lobes on a trailing edge thereof, the trailing edge having a circular crenellated shape. The power generation is controlled by reducing loads and/or controlling impeller speed. Various moveable components are described for the stator vanes and the rotor blades.

1 . A fluid turbine, comprising:
 an impeller for generating power from a fluid stream; and   a turbine shroud surrounding the impeller;   the impeller comprising a stator and a rotor, and the stator or the rotor comprising a moveable component for controlling the fluid stream in the fluid turbine.   
     
     
         2 . The fluid turbine of  claim 1 , wherein the stator comprises a stator hub and one or more stator vanes extending radially from the stator hub, and wherein at least one of the stator vanes comprises the moveable component, the moveable component comprising a stationary member and a first moveable member which are located longitudinally to each other along the stator hub, the first moveable member being able to pivot relative to the stationary member about a radial axis. 
     
     
         3 . The fluid turbine of  claim 2 , wherein the stationary member and the first moveable member are pivotally engaged along a back end of the stationary member and a front end of the first moveable member, the stationary member defining a leading edge of the stator vane and the first moveable member defining a trailing edge of the stator vane. 
     
     
         4 . The fluid turbine of  claim 2 , comprising a plurality of moveable members, a front end of each moveable member being pivotally engaged to a back end of another member, the front end of one moveable member being pivotally engaged to a back end of the stationary member. 
     
     
         5 . The fluid turbine of  claim 2 , wherein the stationary member defines a leading edge and a trailing edge of the stator vane; and wherein the first moveable member forms a portion of an upwind or downwind surface of the stator vane, the radial axis of the first moveable member being located in a central portion of the stationary member. 
     
     
         6 . The fluid turbine of  claim 5 , further comprising a second moveable member that forms a portion of the downwind surface of the stator vane, a radial axis of the second moveable member being located in a central portion of the stationary member, wherein the first moveable member forms a portion of the upwind surface of the stator vane. 
     
     
         7 . The fluid turbine of  claim 1 , wherein the stator comprises one or more stator vanes, wherein at least one of the stator vanes comprises the moveable component, the moveable component comprising a stationary member and a first moveable member, wherein the stationary member defines a leading edge and a trailing edge of the stator vane; wherein the first moveable member forms a portion of an upwind or downwind surface of the stator vane, and wherein the first moveable member is located along a trailing edge of the stationary member and the first moveable member may be deployed downstream of the trailing edge of the stator vane. 
     
     
         8 . The fluid turbine of  claim 7 , wherein the first moveable member is deployed by (i) rotating about a radial axis which is located along a trailing edge of the stationary member; or by (ii) extending longitudinally outwards from the trailing edge of the stationary member. 
     
     
         9 . The fluid turbine of  claim 7 , wherein the first moveable member comprises a nonlinear edge, or wherein the first moveable member comprises a plurality of fluid passages between an upper surface and a lower surface, or wherein the first moveable member has an asymmetrical shape along a radial length of the stator vane. 
     
     
         10 . The fluid turbine of  claim 1 , wherein the stator comprises one or more stator vanes, and wherein at least one of the stator vanes comprises the moveable component;
 wherein the moveable component comprises a leading edge member, an upper surface segment, a lower surface segment, and a trailing edge member;   wherein a back end of the leading edge member is longitudinally engaged with a forward edge of the upper surface segment and a forward edge of the lower surface segment;   wherein a front end of the trailing edge member is longitudinally engaged with a rear edge of the upper surface segment and a rear edge of the lower surface segment; and   wherein the upper surface segment and the lower surface segment can move longitudinally relative to the leading edge member and the trailing edge member to change the camber of the stator vane.   
     
     
         11 . The fluid turbine of  claim 10 , further comprising a plurality of linear motion actuators located within one of the edge members, and cables extending from the linear motion actuators to an upper surface and a lower surface of the other edge member. 
     
     
         12 . The fluid turbine of  claim 10 , further comprising a drive pulley located within one of the edge members and a cable engaging the drive pulley, both free ends of the cable being attached to one or more fixed points within the other edge member, a constant distance existing between the drive pulley and the one or more fixed points, wherein the upper surface segment and the lower surface segment engage the cable on opposite sides of the drive pulley. 
     
     
         13 . The fluid turbine of  claim 10 , wherein linear motion actuators are used to engage the back end of the leading edge member to the forward edge of the upper surface segment and the forward edge of the lower surface segment, and to engage the front end of the trailing edge member with the rear edge of the upper surface segment and the rear edge of the lower surface segment. 
     
     
         14 . The fluid turbine of  claim 1 , wherein the rotor comprises the moveable component, the moveable component comprising a hollow rotor blade, wherein an upstream surface and a downstream surface of the hollow rotor blade each comprise a fluid passage; and located within the hollow rotor blade is a gate that comprises an insert for each fluid passage operatively connected to a pivoting arm, the pivoting arms engaging a weighted member which engages a tension member, the pivoting arms and the tension member cooperating so that below a given fluid velocity threshold, the inserts align with the fluid passages to prevent fluid flow through the fluid passages, and above the given fluid velocity threshold, the inserts are removed from the fluid passages to create an aperture through the hollow rotor blade. 
     
     
         15 . The fluid turbine of  claim 14 , wherein a plurality of inserts are mounted on a plate that is connected to a pivoting arm. 
     
     
         16 . A method for controlling the load experienced by an impeller of a fluid turbine, comprising:
 receiving a fluid turbine that comprises:
 an impeller for generating power from a fluid stream, the impeller comprising a stator and a rotor, the stator or the rotor comprising a moveable component, and 
 a turbine shroud surrounding the impeller; and 
   moving the moveable component between a first position and a second position to control the load.   
     
     
         17 . The method of  claim 16 , wherein the stator comprises a stator hub and one or more stator vanes extending radially from the stator hub, and wherein at least one of the stator vanes comprises the moveable component, wherein the moveable component comprises a stationary member and a first moveable member which are located longitudinally to each other along a stator hub, the first moveable member being able to pivot relative to the stationary member about a radial axis. 
     
     
         18 . The method of  claim 16 , wherein the stator comprises one or more stator vanes, wherein at least one of the stator vanes comprises the moveable component, wherein the moveable component comprises a stationary member and a first moveable member, wherein the stationary member defines a leading edge and a trailing edge of the stator vane; wherein the first moveable member forms a portion of an upwind or downwind surface of the stator vane, and wherein the first moveable member is located along a trailing edge of the stationary member such that the first moveable member may be deployed downstream of the trailing edge of the stator vane. 
     
     
         19 . The method of  claim 16 , wherein the stator comprises one or more stator vanes, and wherein at least one of the stator vanes comprises the moveable component;
 wherein the moveable component comprises a leading edge member, an upper surface segment, a lower surface segment, and a trailing edge member;   wherein a back end of the leading edge member is longitudinally engaged with a forward edge of the upper surface segment and a forward edge of the lower surface segment;   wherein a front end of the trailing edge member is longitudinally engaged with a rear edge of the upper surface segment and a rear edge of the lower surface segment; and   wherein the upper surface segment and the lower surface segment can move longitudinally relative to the leading edge member and the trailing edge member to change the camber of the stator vane.   
     
     
         20 . The method of  claim 16 , wherein the rotor comprises the moveable component;
 wherein at least one rotor blade is hollow, wherein an upstream surface and a downstream surface of the hollow rotor blade each comprise a fluid passage; and located within the hollow rotor blade is a gate that comprises an insert for each fluid passage operatively connected to a pivoting arm, the pivoting arms engaging a weighted member which engages a tension member, the pivoting arms and the tension member cooperating so that below a given fluid velocity threshold, the inserts align with the fluid passages to prevent fluid flow through the fluid passages, and above the given fluid velocity threshold, the inserts are removed from the fluid passages to create an aperture through the hollow rotor blade.