Conversely, the apertures may be open (not covered by the closed cover flaps) when the blade is moving against the flow, minimising the forces acting against the desired rotation of the turbine i.e. Cover flaps or blades that are hydrofoils generate “lift” forces, forces at an angle to the direction of travel of the blade or cover flap, as water flows past them. It is an object of the present invention to provide a water-powered turbine that avoids or minimises at least one of the aforementioned disadvantages of known devices. The turbines of the invention and associated power conversion devices can be fitted with suitable control systems, which may be computer controlled, to adjust the power uptake. A very large number of water-powered devices have been proposed to provide power, for example in the form of electricity, from flowing water. Where the body of water is large, for example a large river or an estuary, then the method may include locating an array of turbines in the body of water.
- Facu89 (discusión) 14:24 3 nov 2014 (UTC)
- Application of the invention embodiments normally intended for wind to water, and vice versa
- Dejar un espacio libre en la maleta
- ¿Su frecuencia cardíaca se siente lenta o rápida cuando experimenta las palpitaciones
- Tomografía por emisión de positrones (TEP)
- Hinchazón dolorosa de las venas (flebitis)
- R the known rotor radius
- Debilidad en los músculos de la cara, aunque suele ser un síntoma poco frecuente
According to a second aspect, the present invention provides a method of extracting energy from within a water flow comprising: locating at least one turbine in a body of water; and extracting energy from the rotation of the said turbine, wherein the said turbine comprises an array of turbine blades formed and arranged for rotation, in use, about an axis substantially normal to the direction of water flow; wherein at least one turbine blade of the array is formed to be adjustable, in use, from a first driving configuration when moving with the direction of water flow, to a second return configuration when moving against the direction of water flow, and wherein the surface area of the turbine blade presented to the direction of water flow is reduced when in the return configuration; whereby in use the turbine rotates as a consequence of the greater force of water flow acting on the turbine blade when in the said driving condition.
Dolor Neuropático Fisterra
In use the turbine of the invention may rotate about an axis that is substantially normal to the direction of water flow i.e. The pivot shaft allows the blade to pivot about an axis at or near one end of the turbine blade. The turbine blades 102 are positioned between a bottom plate 104 and a top plate (not shown in Figure 7) , and comprises a pair of hydrofoil flaps 110. The turbine blades are rotatable about a central axis 109. It should be noted that the term aerofoil when used herein in the figures refers to components that, when in water, operate as hydrofoils. Lift effects are also provided by the hydrofoil flaps 110 that are in positions tangential to the water flow. Dolor de gota en el dedo del pie . In operation, turbine blades 102 that are rotating in the direction of water flow are in their first, driving configurations and have their hydrofoil flaps 110 in their first closed positions 114 so that the hydrofoil flaps 110 present a continuous surface to the water flow and are driven round, in a similar fashion to the embodiment of Figure 1 and 2. However, driving of the rotation of the turbine by such drag effects on flaps in their closed positions 114 only provides for a contribution from each flap during a limited portion (for example 90°) of each 360° rotation of the turbine.
Dolores Musculares Generalizados
The water flow that can be used to drive the turbine may be of any suitable form, for example river current, tidal movement or ocean current. Figures 5a to 5d show a portable turbine unit 32 of the invention suitable for use in a tidal reversing water flow. For example the turbine blades may be adjustable in angle by being rotatable about their join to the centre of the turbine, where they are directly joined to a central shaft or hub. According to a first aspect the present invention provides a turbine for use in extracting energy from within a water flow comprising: an array of turbine blades formed and arranged for rotation, in use, about an axis substantially normal to the direction of water flow; wherein at least one turbine blade of the array is formed to be adjustable, in use, from a first, driving, configuration when moving with the direction of water flow, to a second, return, configuration when moving against the direction of water flow, and wherein the surface area of the turbine blade presented to the direction of water flow is reduced when in the return configuration.
Figures 9a to 9c illustrate one embodiment in which each guide device 105 comprises a roller guide 140 rotatably mounted on an axis 142. It can be seen in Figure 9b that the roller guide 140 engages the track 130 in a stationary portion of the bottom plate during rotation of the turbine. An array of from three to nine blades distributed circumferentially around the turbine axis is preferred.
Conversely the deflector flaps 46 on the downstream face 42 are forced open by the flow allowing water to flow as indicated by the arrows 52, through the apertures 48 on the downstream face 42 as well as through the opening 54 of the funnel 44. Thus a substantially free flow of water is allowed through most of downstream face 42 of the housing 24. This avoids unwanted deflection of flow by the funnel 44 on the downstream face 42, which would cause a loss of power uptake by the turbine 1. (Perspective view figure 5d and its magnified detail shows the downstream face 42 of the housing 24 with its flaps 46 in their open position, uncovering the apertures 48). Possible materials include so- called sheet moulding compounds (SMC) , which typically are fibreglass-reinforced thermosetting plastics compositions.
These can be used to make structural components (by compression moulding techniques) that are thin, lightweight and require complex shaping, such as the turbine blades or blade components. Advantageously the cover flaps, where fitted, or the turbine blades themselves are formed and arranged to move from their first to their second positions by the force of the same water flow that rotates the turbine.
Figure 13 is a cross sectional view of a hydrofoil that is used in various embodiments of the turbine. A flow deflector acting in this way may increase the efficiency of power extraction by reducing or even eliminating the force of the water flow, downstream of the deflector. When the turbine blade is on the return, rotating against the direction of water flow, the flap is pushed open by the water, allowing water to flow more or less freely through the aperture, greatly reducing the force of the water flow acting against the desired direction of turbine rotation. In use the turbine may rotate as a consequence of a greater force of water flow acting on the turbine blade when in the said driving condition. The flow deflector may be located in use in front of the turbine (i.e. Turbines of the invention can be built to any desired scale to suit the water flow conditions and desired power output.
For example, a single control system may be used to monitor and control the array of turbines.
The aperture 8 has a surround 23 against which the cover flap 10 rests when closed. For example the blades may be mounted on a plate, which is itself mounted on a central shaft. 124. In the variant of Figure 8 , instead of a separate machined track 107 for each hydrofoil flap being provided on the bottom plate 104, a pair of tracks 130, 132 are provided in a stationary base plate portion. For example, a single control system may be used to monitor and control the array of turbines. A neutral buoyancy, at the depth of water where the turbine is located in use, is preferred.
Greater power extraction can be obtained where the turbine blades, or cover flaps fitted to apertures in the turbine blades, are formed and arranged to extract power from the water flow when on the return. Dolor de espalda con ardor . The stop is positioned so as to hold the turbine blade in the first, driving configuration. The water flow will continue to be directed onto the same face of each turbine blade 2, causing the cover flaps 10 to close when the blades 2 are driven and to open when the blades 2 are on the return 28. This arrangement also avoids the complications associated with power take off from a turbine whose direction of rotation reverses in use. A single flow deflector may be formed and arranged to both deflect flow away from turbine blades on the return and concentrate flow onto turbine blades when being driven. Appropriate cabling 38 connects from the power take off housing 36 to the water surface to allow extraction of electricity and passage of control and monitoring signals to and from the unit 32. The housing 24 is formed to act as a flow deflector 26 in both directions of a tidal flow.
Dolor Neuropático Que Es
Said at least one turbine blade may be formed and arranged to generate lift when in the return configuration to rotate the turbine. This arrangement allows maximum interaction between the turbine blade and the water flow when the flow is pushing the turbine blade. The hub is of steel all welded construction.
The flow deflector or housing may be moveable. Said at least one turbine blade may be formed and arranged to experience in operation a drag force from water flow acting on the turbine blade when in the first, driving configuration, the drag force acting to rotate the turbine. Dolor muscular de brazo derecho . Figure 3 shows in detail a part of a turbine blade 2 with a cover flap 10 in an open second position with respect to its corresponding aperture 8. A stop 22 fitted in the pivot 12 prevents over rotation of the flap past its desired second position, ensuring closure of the flap in the correct direction, over the aperture 8, as rotation continues. Preferably the hydrofoil cover flap or turbine blade is held tangential to the direction of rotation of the turbine during part of the return. Constraining the motion of the hydrofoil cover flaps or turbine blades can be achieved in a number of ways.