BUOYANT SUBSURFACE FLOAT

Abstract

A buoyant subsurface float is configured to provide a stable platform below a surface of a deep water upon a sea floor. The buoyant subsurface float has a platform configured to be buoyant and submerged in the deep water. A tethering system is attached to the platform and further attached to the sea floor. The tethering system holds the platform at an intermediate depth of water between the surface and the sea floor. A surface equipment is attached to the platform and configured to perform a function normally performed on a surface of shallow water.

Description

BACKGROUND

The embodiments herein relate generally to ocean engineering.

Prior to embodiments of the disclosed invention, shallow water systems could not be installed in deep water. Embodiments of the present invention solve this problem.

SUMMARY

A buoyant subsurface float is configured to provide a stable platform below a surface of a deep water upon a sea floor. The buoyant subsurface float has a platform configured to be buoyant and submerged in the deep water. A tethering system is attached to the platform and further attached to the sea floor. The tethering system holds the platform at an intermediate depth of water between the surface and the sea floor. The buoyant subsurface float supports the weight of the tethering system. A surface equipment is attached to the platform and configured to perform a function normally performed on a surface of shallow water.

In some embodiments, sensors that monitor a state of the water are attached to the platform. The sensors may be communicatively coupled to the tethering system or to a surface element for communication to other systems. Other sensors may be incorporated to sense acoustic signatures in the water.

In some embodiments, the tethering system includes a first anchor cable, attached to the platform and further directly attached to a first anchor. A second anchor cable is attached to the platform and further directly attached to a second anchor. A third anchor cable is attached to the platform and further directly attached to a third anchor. The first anchor, the second anchor and the third anchor may be partially buried into the sea floor. In other embodiments, a single anchor cable and anchor are used.

In some embodiments, the surface equipment includes a surface platform, configured to rest on the surface of the deep water whether in a crest or a trough. A first generator and a second generator are mechanically coupled to surface platform. Lines are attached to the first generator and the second generator, which are further attached to the platform.

BRIEF DESCRIPTION OF THE FIGURES

The detailed description of some embodiments of the invention is made below with reference to the accompanying figures, wherein like numerals represent corresponding parts of the figures.

FIG. 1 shows a side view of one embodiment of the present invention.

FIG. 2 shows a side view of one embodiment of the present invention.

FIG. 3 shows a side view of one embodiment of the present invention.

FIG. 4 shows a side view of one embodiment of the present invention.

FIG. 5A shows a side view of one embodiment of the present invention.

FIG. 5 b shows a side view of one embodiment of the present invention.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

By way of example, and referring to FIG. 1, one embodiment of buoyant subsurface float 10 comprises platform 12. Platform 12 is configured to be buoyant. One function of buoyant subsurface float 10 is that it enables shallow water surface equipment to be used in deep water by being submerged at an intermediate depth. Shallow water is defined as being 20 meters or less. Deep water is defined as being 150 meters or more. This application uses the term “intermediate depth of water” to mean at least 20 meters but no more than 30 meters.

One example of surface equipment 30 that can be used effectively in shallow water but not so in deep water is oscillatory motion power equipment. Oscillatory motion is highest at the surface and diminishes exponentially with depth. However, for standing waves (clapotis) near a reflecting coast, wave energy is also present as pressure oscillations at great depth, producing microseisms. These pressure fluctuations at greater depth are too small to be interesting from the point of view of wave power.

One of the challenges that can affect the efficiency of deep water wave power generation is high speed underwater currents. Currents are typically fastest within 200 meters from the surface and can be measurable (though less) at much greater depths. Current, along with other sea conditions are measured with sensors 14 mechanically coupled to platform 12.

Tethering system 20 is configured to tether platform 12 to sea floor F. Tethering system 20 is shown with platform 12 directly attached to first anchor cable 22A. First anchor cable 22A is directly attached to first anchor 24A. Platform 12 directly attached to second anchor cable 22B. Second anchor cable 22B is directly attached to second anchor 24B. Platform 12 directly attached to third anchor cable 22C. Third anchor cable 22C is directly attached to third anchor 24C. First anchor 24A, second anchor 24B and third anchor 24C are partially buried into sea floor F. In some embodiments, as shown in FIG. 2, a single anchor cable is mechanically coupled to a single anchor 24 which connects platform 12 to sea floor F.

In some embodiments as shown in FIG. 3, instead of a single platform 12, there can be a first platform 12A, a second platform 12B, and a third platform 12C. First platform 12A is mechanically coupled to first anchor 24A with first anchor cable 22A. Second platform 12B is mechanically coupled to second anchor 24B with second anchor cable 22B. Third platform 12C is mechanically coupled to third anchor 24C with third anchor cable 22C. Alternately, as shown in FIG. 4, second platform 12B is mechanically coupled to first platform 12A and third platform 12C. Each platform is mechanically coupled to a single anchor cable 22 which is mechanically coupled to a single anchor 24. Here, the platforms are connected to anchor cable 22 with anchor wire 26.

Tethering system 20 can be communicatively coupled to sensors 14. For instance, depending on currents and sea state first anchor cable 22A, second anchor cable 22B and third anchor cable 22C can be slackened or tightened. This can be used to ensure that buoyant platform 12 is parallel to sea floor F, perpendicular to sea floor F or somewhere in between parallel and perpendicular. In any event, platform 12 should be a stable platform characterized in that it moves very little if at all. As used in this application very little movement is a few inches per day.

Surface equipment 30 is configured to be shallow water surface equipment that is configured to work in shallow water, but is enabled to work in deep water due to buoyant subsurface float 10. In the exemplary embodiment, water W has surface S that moves from crest S1 to trough S2 due to waves. Surface equipment 30 can generate electrical power from this movement. Surface platform 32 is configured to rest on surface S of water W whether in crest S1 or trough S2. First generator 34, second generator 35 and third generator 36 are mechanically coupled to surface platform 32. First generator 34, second generator 35 and third generator are further attached to line 38, which is further attached to platform 12.

As waves cause surface platform 36 to rise and fall, line 38 rotates first generator 34, second generator 35 and third generator. This causes electrical power that is stored in a battery (not shown). Of course, the wave power generator is only an example of equipment that can be utilized with buoyant subsurface float 10.

Finally turning to FIG. 5A and 5B, buoyant subsurface float 110 further comprises circumferential frame members 112 arranged into frame 114. Frame 114 is attached to tension member assembly 116 and frame bottom 126. Frame bottom 126 further comprises a plurality of valves 124 attached to frame bottom 126 with spring hinges such that the valves open inward as anchor cable 122 pulls buoyant subsurface float 110. The frame is mechanically coupled to fabric membrane 130 which is configured to generally contain water within buoyant subsurface float 110.

In this embodiments, frame 114 can be fabricated of metal or composite materials, with or without tension member elements of metal or synthetic construction. The structure provides buoyancy to maintain tension in the structure and the mooring system. Anchor cable 122 can be attached to any point on the structure. Once attached, buoyant subsurface float 110 can be suspended in the water column by a tension member assembly 116 that may be made of metal or synthetic tension elements. The mass of water inside of buoyant subsurface float 110 increasing the resistance to motion of buoyant subsurface float 110 to imposed forces.

In some embodiments, vertical drag and inertia loads are carried by frame 114. Fabric membrane 130 structure does not carry any of these loads. Alternative constructions can use the fabric structure as a load-carrying member. Hoop tension from internal pressure is carried by fabric membrane 130 and circumferential frame members 112. Internal pressure is caused by dynamic pressure at the mouth of the cone due to velocity and the inertia of the water column due to acceleration. This provides the resistance to motion of buoyant subsurface float 110.

All references throughout this application, for example patent documents including issued or granted patents or equivalents, patent application publications, and non-patent literature documents or other source material, are hereby incorporated by reference herein in their entireties, as though individually incorporated by reference, to the extent each reference is at least partially not inconsistent with the disclosure in the present application (for example, a reference that is partially inconsistent is incorporated by reference except for the partially inconsistent portion of the reference).

A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.

Any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specified function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. §112, ¶6. In particular, any use of “step of” in the claims is not intended to invoke the provision of 35 U.S.C. § 112, ¶6.

Persons of ordinary skill in the art may appreciate that numerous design configurations may be possible to enjoy the functional benefits of the inventive systems. Thus, given the wide variety of configurations and arrangements of embodiments of the present invention the scope of the invention is reflected by the breadth of the claims below rather than narrowed by the embodiments described above.

Claims

1. A buoyant subsurface float, configured to provide a stable platform below a surface of a deep water upon a sea floor; the buoyant subsurface float comprising a platform configured to be buoyant and submerged in the deep water;a tethering system attached to the platform and further attached to the sea floor;

2. The buoyant subsurface float of claim 1, further comprising sensors that monitor a state of the water; wherein the sensors are communicatively coupled to the tethering system.

3. The buoyant subsurface float of claim 2, wherein the tethering system comprises: a first anchor cable, attached to the platform and further directly attached to a first anchor;a second anchor cable, attached to the platform and further directly attached to a second anchor;a third anchor cable, attached to the platform and further directly attached to a third anchor;wherein the first anchor, the second anchor and the third anchor are partially buried into the sea floor.

4. The buoyant subsurface float of claim 3, wherein the surface equipment comprises: a surface platform, configured to rest on the surface of the deep water whether in a crest or a trough;a first generator and a second generator, mechanically coupled to surface platform a line, attached to the first generator and the second generator, which is further attached to the platform.

5. A buoyant subsurface float, configured to provide a stable platform below a surface of a deep water upon a sea floor; the buoyant subsurface float comprising frame members arranged into frame;a fabric membrane attached to the frame;a tension member assembly attached to frame and forming a platform configured to be buoyant and submerged in the deep water;a frame bottom, attached to the frame and further comprising a plurality of valves;