US20120213592A1

US20120213592A1 - Submerging offshore support structure

Info

Publication number: US20120213592A1
Application number: US13/031,179
Authority: US
Inventors: David Bruce Nowlin
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-02-18
Filing date: 2011-02-18
Publication date: 2012-08-23

Abstract

This is a support structure for situating and protecting operative devices in deep offshore locations to include certain types of wind turbines. The support structure can be made to submerge and reemerge automatically, with the operative device, to avoid damage that would be caused by hazards in a marine environment at or near the water's surface. Approaching hazards are detected remotely and by sensors located on and around the supporting structure. Critical environmental and support structure conditions are constantly monitored and managed by computer through a network of sensors, equipment controls, and pre programmed response sequencing.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

SEQUENCE LISTING OR PROGRAM APPENDIX

Not Applicable

BACKGROUND OF THE INVENTION

The present invention relates to the field of mid- and deep-offshore fixed supporting structures, particularly those supporting wind turbines as operative devices. More specifically, the present invention provides a fully submersible structure to avoid destructive hazards commonly found in offshore marine environments.

DESCRIPTION OF RELATED ART

Wind power is an alternative source of energy which is perpetual, though periodic, sustainable and clean. Once past the initial capital investment, the cost of running a wind driven power generating station is relatively minimal. Innovative communities have erected wind turbines in clusters to leverage the advantages of wind power. These clusters sometimes referred to as “wind farms,” have been relatively successful at supplementing fossil-fuel burning power generating stations.
At the same time, concerns over the environmental impact of wind farms have prevented some communities from adopting wind power conversion systems. Since maximum efficiency is obtained by locating turbines in positions having strong and steady wind, turbine towers are routinely proposed to be situated on hillsides or in large open areas. Such proposals commonly evoke concerns relating to the aesthetics of locating a tall and noisy tower in places routinely visible to the public.
Improvements to traditional wind turbine applications include locating wind power structures offshore. Placing wind turbines in open water provides optimal conditions for maximum power production because flow is less obstructed and wind speed is generally higher. Moreover, when off shore wind farms are situated beyond the visible range of the coast, they are less likely to provoke complaints which have proven to hamper projects based on land or in shallower water.
However, benefits gained by locating wind turbines offshore are largely offset by increased costs. Locating turbines deep offshore, beyond the visible range of land, requires supporting structures which must rise several thousand feet from the sea floor while enduring all conditions of weather and seas. Such designs are expensive to engineer and construct. Even support structures which are located in relatively shallow water consume significantly more building materials than would be required to build a suitable support structure on land in order to withstand the projected loading of severe storm conditions. Costs for offshore structures are also higher because materials must perform in the caustic environment of the open sea. Similarly, assembling, erecting or repairing components in challenging marine environments is more complicated and therefore more costly.
Wherever wind driven power stations are located, they are subject to damage from excessive wind speed. Typically, turbine supporting structures are designed to tilt turbine blade edges toward the direction of the wind, or “furl,” whenever the preferred wind speed limit is exceeded. Other designs have incorporated electrical or mechanical brakes which slow the turbine rotation to prevent damage. Wind turbines located offshore are subject to additional hazards peculiar to a marine environment. Corrosion from battering saltwater, and forces from waves and tides, can be destructive to turbines and supporting structures. Collisions with routine waterway traffic during conditions of low visibility or mechanical failure are also a potential hazard. Irrespective of the source of damage, repairing large offshore structures is costly, particularly when productive operations must be suspended for the purpose of carrying out these repairs.
Supporting structures that accommodate at least some of these hazards have been developed for the petroleum industry. Many exist worldwide to support operative devices used to access offshore oil and natural gas. Conventional structures have traditionally required substantial amounts of steel to withstand adverse marine environmental conditions. With the need to function in deeper and deeper water, such material intensive designs become cost prohibitive to serve as support structures for wind generated power. U.S. Pat. No. 4,781,497 to Karsan et. al addresses the burdensome material requirements of offshore platform towers by employing a compliant design. Rather than countering the effects of weather and waves with substantial amounts of concrete and steel in a massive and rigid platform tower, the structure disclosed by Karsan is designed to move and flex. However, the Karsan design incorporates several substantially rigid and massive sections between the sea floor and surface, thereby minimizing a reduction in the material it requires.
Petroleum mining has also motivated the development of other material minimizing approaches to structural support for operative devices positioned in deep water. In general, these improvements rely upon buoyancy for stability and include various forms of Spar, tension leg, and semi-submersible design, all of which are well known in the field. Representative examples of offshore petroleum mining support structures include those disclosed in U.S. Pat. Nos. 6,884,003 and 6,935,810 issued to Horton, and 6,854,411 issued to Ankarsward. The structures in these patents are highly buoyant and are situated at their operative sites by minimal structural connections to the sea floor. Though semi-submersible designs reduce the likelihood of damage from adverse weather and surf, their major operative components relating to petroleum extraction situated permanently above the surface are left largely unprotected from unanticipated weather or collision with iceberg or vessel.
Advancements in buoyant structures have been used to support other operative devices including those central to the wind-power conversion field. U.S. Pat. Nos. 7,075,189 to Heronemus et. al and 7,156,586 to Nim disclose buoyant structures fixed in position by traditional subsurface moorings for the purpose of situating wind turbines offshore. In comparison to support structures having more rigid foundations, the structures disclosed in these patents appear to provide the ability to reposition expensive turbines out of harm's way whenever a hazardous condition exists. However, the buoyant nature of the structures provide little stability for connecting to underwater power grids and the act of protecting operative devices from approaching hazards require quickly moving the structures substantial distances soon after a harmful hazard is perceived.
Rising energy prices and environmental concerns suggest that maximizing the use of alternative sources of power is essential. Tax credits and other financial incentives have been established to encourage the development of technology which harnesses power from the wind. Despite these motivating factors, wind power still amounts to only a small portion of the world's total energy production. The significant capital outlay needed to build and install equipment and infrastructure remains a substantial barrier to the wide spread application of wind power. Waves, weather, and sea-going traffic are among the many hazards with which an offshore turbine must routinely contend. Under severe conditions, substantial investments necessary to position wind based power generating stations offshore are placed at risk. For electrical grids to rely on substantial production deep offshore, the potential for loss of sizeable quantities of production must be virtually eliminated. Improvements in the protection of offshore wind turbines are needed to make large scale investment in deep offshore wind power more financially sound. More specifically, there is a need for an offshore power generating structure which safeguards itself and its operative equipment by avoiding destructive hazards through efficient and reliable design.

BRIEF SUMMARY OF THE INVENTION

Accordingly, it is an object of this invention to provide a cost-effective support structure for locating operative equipment in moderately deep and deep sea water.
It is another object of the invention to provide a support structure particularly adapted for wind turbines which cost effectively minimizes potential damage from destructive hazards typically expected in a marine environment.
It is still a further object of this invention to provide a low-cost and reliable wind-driven power generating station optimally situated for maximum power production.
These and related objects are achieved through the use of the novel supporting structure which is herein disclosed. This structure has the designed capability to totally submerge to avoid perceived threats, as hereinafter described, and to re-emerge when the threats are passed.
The structure transitions itself and its operative device or devices (hereafter referred to in the singular, though multiple operative devices can be equally accommodated) between its physically extended operating and submerged positions to achieve protection from destructive forces. Before a potentially damaging threat causes damage, the structure and operative device are submerged under the sea water's surface to reside at a safe depth until the hazardous condition passes. The transition of the supporting structure from extended to submerged positions and back again may be activated manually, on command from a person functioning as steward, or automatically by a computerized system incorporating sensors able to detect hazardous conditions as well as those that report the support structure's status of all equipment components throughout each initiated command.
A supporting structure in accordance with this invention is characterized by being located in mid to deep offshore waters. A principle aspect of the present invention is to improve the likelihood that, whatever the operational device installed to operate in open water, it will continue to function despite hazards brought upon it by extreme weather, seas and potentially damaging marine traffic. These environmental certainties have been addressed in the prior art by constructing support structures to design parameters estimated to endure the projected hazards that might occur while the operative device remains continually in its operative position above the water's surface. Compared to the present invention, such designs still leave major support structure components and the operative device substantially vulnerable. Support structures embodying this invention are an improvement over the prior art in that their ability to fully submerge allows them to achieve a cost effective approach to providing a reliable and enduring platform or support structure for the expensive operative device, allowing for numerous wind turbine designs.
While this invention has been motivated by the need for increased wind-driven energy production, the invention of this submergible support structure has application to many non-energy generating operative devices which would derive benefit when positioned to operate offshore. Various operative devices may be fortified to withstand the marine environment by using seals and durable materials or they may be completely encapsulated by the supporting structure in a manner that avoids direct destructive contact with corrosive salt water and other harms typical of periodic submersion in the underwater environment. Such fortification or waterproofing of the operative device, which is required by certain embodiments of this invention, provides the added advantage of making the turbines, or other operative devices, more impervious to the operating conditions encountered at sea above the water's surface. The fortification of components of the support structure to withstand being repeatedly submerged may include provisions to combat bio-fouling.
A fully submergible structure, according to the invention disclosed herein, is comprised of three functional zones in basically vertical alignment. From bottom to top, the zones will be referred to as the foundation, active, and primary zones. The foundation zone provides an economical and stable footing for anchoring and connecting the system or ancillary components of the invention. The active zone provides the repositioning movement which allows the overall structure to evade damage. Motive forces generated in the active zone cause the structure to extend and retract, thereby rising above the surface of the water and escaping below the water's surface as needed. The motive force may be accomplished by numerous means including mechanical levers, counter balance, pulleys and cables in conjunction with flood tanks or expandable vessels, hydraulic rams, electric solenoids, or other conventional methods of supplying movement. Mechanical, electrical, and hydraulic components involved with generating the force for transition movement between fully submerged and extended positions of the structure may be fortified with seals, treatments, and other provisions to withstand underwater harms. Finally, the primary zone is the vertical area where the operative device is mounted. When the invention is in the extended position, an operative device, such as a wind turbine, is positioned for full and productive operation.
As noted above, this invention may be employed in the service of various operative devices. A particular operative device will generate a unique design response, in part, in the invention's application. In the presentation of the invention, the operative device chosen for elaboration will be the wind-energy conversion device.
Within that functional category, two types of wind turbines will be used to present the invention. These are, first, a single horizontal commercial wind turbine; and second, a WARP (Wind Amplifier Rotor Platform), as patented by ENECO, of West Simsbury Conn., USA.
This preliminary application will present three embodiments of the invention, utilizing wind-energy conversion mechanisms. Two embodiments will use a single, horizontal commercial wind turbine, and one will use the WARP mechanism.
Further specifics of the present invention are described in detail below.
The operative device's transitions between the fully extended support structure position in the primary zone where it functions or operates, and the submerged protective position in the active zone where it is harbored to avoid hazard, are accomplished by the motive force produced by components of the active zone. An operative device may produce energy or perform another function. In all cases, the operative device (or devices) is that productive element which the structure has been designed to support. Given that the support structure disclosed herein can be submerged to avoid even moderate hazards, it may be designed more elegantly than other structures which must be built to remain above the surface and withstand the harshest situations of weather and seas projected by the designers. Construction of the structure employs standard techniques used to build spar and tension leg platforms as have been used by the petroleum industry. Likewise, standard methods for erecting wind turbines and similar massive structures offshore that are known by those skilled in the art are those referenced to be employed.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

As noted above, three embodiments of the invention, utilizing wind-driven conversion mechanisms, will be presented. In the examination of these embodiments, it is useful to keep six aspects of design in mind.

Method of control. The method of control determines when to submerge and ascend, and activates the necessary action for each to occur. Possible methods of control may be a steward positioned on board the support structure to monitor conditions and activate protective actions manually; a remote steward with wireless or hard-wired capability to monitor conditions and direct action; automatic control by preprogrammed computer system; or any combination of these. Controls may be clustered, allowing one data intake and action activation source to direct a group of support structures.

Submersion strategy. Embodiments may differ in the types of operative device submersion strategies employed. For instance, these could include direct contact with water and pressure during submersion, partial enclosure of the operative device for protection from direct exposure to water and pressure prior to submersion, or encapsulation which totally shelters the operative device in an enclosure for complete protection from direct exposure to water and pressure during submersion. Direct contact and encapsulation are the two submersion strategies shown in the embodiments that follow.

Method of motive force. Different primary methods of creating and applying motive force are possible in causing the support structure to submerge and ascend. Possible sources include weight transfer, buoyancy transfer, or buoyancy altering by means of flood tanks or expandable air tanks Any of these could be used in conjunction with stored or operative-device generated electrical power and hydraulics. Buoyancy altering is the motive force that is shown in the embodiments that follow.

Method of guiding movement. Another variable is the method of physically guiding the movements of components during submersion or ascension. Possible guiding methods may be a rail and guide system, or a continuous line tension system. Both guiding systems are shown in the embodiments that follow.

Type of operative device. This was previously described in general terms. Particularly, the support structure may be shown with a conventional, large, horizontal wind turbine, as manufactured by General Dynamics, among other companies, or a Wind Amplifier Rotor Platform (WARP), as licensed by ENECO of West Simsbury, Conn., USA. Both possibilities are shown in the embodiments that follow.

Auxiliary Elements. Other substantial elements are present, though unnecessary to the invention because they either support a unique functional requirement or enhance the installation's operation. An example of such an element would be a staging base. Auxiliary elements are shown on all but the first embodiment.

The embodiments illustrated in the six figures which accompany the direct description are as follows:

FIG. 1 is a simplified elevation view of Embodiment #1. This is automatic, remote or manual control, direct-contact, buoyancy altering, constant-tension support structure for a single conventional wind turbine, in the extended position.

FIG. 2 is an elevation view of a deployed blade protection system for Embodiment #1 above and Embodiment #2, below.

FIG. 3 is a simplified elevation view of Embodiment #2. This is an automatic, remote or manual control, direct-contact, buoyancy altering, constant-tension support structure for a single conventional wind turbine, with staging base and out-rigger, in the extended position.

FIG. 4 is a simplified partial cross-sectional view of Embodiment #3. This is an automatic, remote or manual control, encapsulating, buoyancy-altering and hydraulic, rail-and-guide support structure for a WARP, with outrigger, in the extended position.

FIG. 5 is a simplified partial eroded sectional view of the travel tube and guide-well of Embodiment #3.

FIG. 6 is a simplified partial cross-sectional view of Embodiment #3. This is an automatic, remote or manual control, encapsulating, buoyancy-altering and hydraulic, rail-and-guide support structure for a WARP with outrigger, in the fully submerged position.

DETAILED DESCRIPTION OF THE INVENTION

The support structure gains advantage from being located off shore, by being situated beyond the visible range of persons located on shore, yet is positioned closer to large urban demand than most metropolitan areas allow for land-based sitting. This reduces the power transmission distance while gaining access to increased wind speeds. The term “wind turbine” is meant to describe all components of a wind turbine's system including mechanical and electrical systems' parts typically used to convert, regulate, or store power output, so that a wind turbine may be made to economically serve an electrical power transmission grid.
Corrosion-resistant materials, such as Ferro-Cement, corrosion-resistant alloys, non-metallic materials such as plastics, ceramics, glass, graphite, and composite materials such as fiberglass or carbon-fiber reinforced plastic, are used throughout the structure wherever possible to increase strength and resistance to the caustic environment while simultaneously contributing to the reduction of each component's weight. Elements should be fortified where appropriate with special seals, paint coatings, plantings, and other treatments as appropriate to their function.
To understand the invention, it is best to think about any embodiment as consisting of the three functioning zones (described in Section 3, above) that work in concert and are vertically aligned. Depending on the particular embodiment, these zones may vary in size vertical position, and in the degree of over-lap with the adjacent zone. To recap, from bottom to top, the zones are: the foundation zone, the active zone, and the primary zone. The foundation zone provides the grounding or resistance to all loading of the invention above. The active zone is the portion of the invention which generates the motive force required to protect the operative device for continued operation. The primary zone is the support structure's mounting of the operative device, which, when fully extended, places the operative device in its intended functioning position for operation.
The following embodiments illustrate the invention's benefit to wind-generating devices. As noted above, any endeavor requiring fixed position operation at or near the surface of a body of water could benefit from this invention for protection of the operative device against surface hazards.
FIGS. 1, 3, 4, and 6 show embodiments of the invention. Vertically, from bottom to top, each indicates a foundation zone 1, an active zone 2, and a primary zone 3. The designation of zones is intended only to be functionally descriptive and approximate rather than physically exclusive. Foundation zone 1 is characterized by having components which are relatively immobile, whereas active zone 2 and primary zone 3 components are relatively mobile and proceed through controlled movements as a result of forces generated by the structure. In practice, components of each zone may fall within the physical boundaries of the other zones either permanently or temporarily during the transition between the support structure's vertically polar positions of submersion and extension.
In the following descriptions, the term “ocean” will be used even though this invention is usable in any body of water that provides adequate depth in which the invention can function as intended to the user's benefit. For additional contextual reference, mean sea level 5 and a depth of 80 feet below mean sea level 6 are identified on FIGS. 1, 3, 4, and 6. Mean sea floor 4 is also shown on FIGS. 1 and 3.
It should be noted that the proportions of many components have been selected to provide maximum figure clarity. Actual engineered selections for the relative size and proportions of these components may vary from those that the drawings depict.
FIG. 1 shows an embodiment of the invention in the extended position. This figure shows an offshore support structure which has been adapted to support a conventional wind turbine. The operative device direct-water-contact-protection strategy of this embodiment is to manufacture the operative device with all necessary precautions to allow it to accommodate submersion to prescribed depths and to allow direct exterior surface exposure to wea water without additional protection. Further, the entire embodiment of the invention is shown. All elements of all three descriptive zones are illustrated to provide the conventional context within which the invention is described.
Foundation zone 1 in this and other embodiments of the invention consists of some method of anchoring and some method of mooring the fixed installation above. The method of anchoring the support structure to the ocean floor could be any method of anchoring currently known to the art. FIG. 1 illustrates a dead weight anchoring base 100. Other possible anchoring methods are driven piles, driven anchor plates, or torpedo embedded anchoring. All provide points of attachment for mooring tendons 101, which offer adequate resistance to all anticipated loading.
FIG. 1 shows a mooring system of a tension-leg design. The tension-leg system will consume minimal materials yet adequately stabilize the connection points for the remainder of the structure above. Taut-leg or catenaries' mooring systems could be used, if design requirements dictate. Whatever the anchoring device strategy, it is critical that the connections securing mooring tendons 101 be designed to accommodate all live and dead loadings of the total structure.
This segment of the invention, foundation zone 1, can be independently installed and left in readiness to receive the remaining portion of the invention at a later time, allowing a reduced period of time for completion of the installation.
Active zone 2 of FIG. 1 is where the motive forces are generated which allow the structure to submerge and ascend. Components of active zone 2 must accommodate live and dead loading that results from all moving components of the structure as they extend and retract, external forces placed upon the structure both above and below the water, as well as substantial forces of inertia.
Components may be moved or slowed by altering component buoyancy, cable friction, and acquiring or relinquishing buoyant vessels or dead weight. Other means may include mechanical levers, motorized pulleys and cables, hydraulic rams, electric solenoids, and other well known conventional methods. Counter-balancing, block-and-tackle and incremental gears are among the mechanisms that may be incorporated to enhance the application of the motive force.
Active zone 2 of the embodiment of the invention illustrated in FIG. 1 is comprised of the following components: submerging spar 102, spar flood tank 103, ballast tank 104, constant tension devices 105, line locks 106, depth sensor 107, flood tank purge system 108, computer 109, gyroscope 110 and communication transmitter/receiver 111.
Within active zone 2 of FIG. 1 is submerging spar 102. A spar is used because of its stability or resistance to loading by wave action at or near the surface. Additionally, the cylinder shape is non-directional, allowing a change in wave orientation to be readily accommodated. Reducing the surface area of the spar, within the wave action zone and near the water's surface, could be incorporated to further reduce wave action loading. The continuous vertical cylindrical shape also allows organization of all support structure elements within a inter-connected interior space for protected ready access to components as required. It also minimizes the exterior surface area resistance to water current loading.
Submerging spar 102 descends to a depth that is adequate to protect the operative device. A minimum depth of 80 feet is generally considered adequate to escape the effects of damaging storms and accompanying turbulent seas. An adequate protective depth may vary, depending on the environmental and marine traffic conditions of the specific installation site.
In FIG. 1, the structure's motive force is generated by changing the buoyancy of spar flood tank 103. At least six constant tension devices 105 are attached to submerging spar 102. Each device is positioned equidistant about the circumference of submerging spar 102 and receives the end of one of mooring tendons 101 and automatically maintains a preset tension level when the tension in the line changes. Maintaining each mooring tendon 101's tension level, during movement of submerging spar 102, provides control and direction to the structure. Each Line lock 106 is released and set by computer 109 in coordination with the required adjustment of each constant tension device 105. Each constant tension device 105 is programmed to re-establish a pre-programmed line tension and to respond to adjustments directed by computer 109.
FIG. 1 also shows gyroscope 110 which is internally mounted. Gyroscope 110 provides sensor data to computer 109 regarding the support structure's vertical orientation. Computer 109 activates appropriate constant tension devices 105 to maintain a desired gyroscope 110 reading.
Ballast tank 104 is positioned at the bottom of submerging spar 102 to create the lowest center of gravity possible. Flood tank purge system 108 and spar flood tank 103 work in concert to increase and decrease the support structure's buoyancy as directed by computer 109.
Depth sensor 107 provides data to computer 109 to indicate the support structure's current vertical position. These readings are used to time the initiation of changes in buoyancy of the support structure. The remote monitoring and the remote initiation of commands to direct the operation of the support structure is made possible by communication transmitter/receiver 111.
Within primary zone 3 are sensor buoy 112, operative device 113, and the upper portion of submerging spar 102, which is exposed to air when it is in the extended position. Additionally, positioned on operative device 113 are blade web storage cabinets 114 and extendable bows 115. On the upper portion of submerging spar 102 is located wave sensor grid 116. Fixed in position on sensor buoy 112 are multiple environmental sensors 117, equipment sensors 118, and warning system 119.
This portion of submerging spar 102 acts as a tower to elevate the operative device above the water's surface, and structurally resists all loading created by the wind, waves, and blade rotation forces. It provides a stable functional mounting for the turbine at its top.
Sensor buoy 112, which is harbored in the top of the wind turbine nacelle 120, provides sensor data continuously. When submerging spar 102 is in the submerged position, sensor buoy 112 is periodically deployed to the water's surface to ascertain prevailing conditions, and transmit that sensor data to computer 109. Sensor buoy 112 has, as primary component parts, environmental sensors 116 and equipment sensors 118. Sensor buoy 112 is located to avoid all other support structure and operative device components.
As applied in all embodiments depicted, the air pressure in potentially buoyant components and the setting or releasing of the line locks is controlled automatically by a computer after receiving inputs from one or more environmental sensors. Equipment sensors are also located on various parts of the structure, to communicate component status to the computer. Environmental sensors are located below, above, or at the water's surface to provide data about hazards and environmental conditions existing in the vicinity of the structure. Multiple environmental sensors obtain and send wave, air pressure, humidity, and air temperature data and closed circuit video images to the embodiment's computer or steward. Inputs from environmental sensors are used to determine when the supports structure should be submerged to avoid damage as well as when it is safe for the support structure to emerge and be extended and resume operations. The computer may be programmed to relinquish control to a remote operator, i.e., a steward. The steward may be located on, near, or far from the structure.
For economic reasons, these environmental sensors can be mounted directly on the support structure or can be positioned on dedicated buoys strategically positioned within and about an operative device field, relaying data to a single or reduced number of computers that are equipped to control more than one support structure simultaneously.
Warning system 119 is both auditory and visual. It warns of imminent submersion or descent of the support structure.
In preparation for submerging during rough seas, extendable bows 115, located on opposite sides of wind turbine nacelle 120, open and lock into a position perpendicular to the long side of nacelle 120. This is to diminish the wind and wave loading on nacelle 120 as the turbine blade plane, in preparation for submerging, is rotated to align with the direction of the oncoming waves. Blade web storage cabinets 114 stores a hydraulically deployable blade bracing system that protects the blades against damage during the blades' movement through the wave action zone. This component is further described in FIG. 2.
Wave sensor grid 116 is comprised of environmental sensors uniformly placed in a grid pattern about the full circumference of submerging spar 102's shaft. These detect the direction, height, and frequency of wave action when the support structure is in the fully extended position. Each sensor, comprising the wave sensor grid 116, switches on or off upon physical contact with the water. The sensor grid pattern of water contact is continually sent to computer 109 for wave action analysis. The wave data is employed to determine and then orient the operative device 113 blades to best advantage prior to movement through the wave action during descent or surfacing.
Transmission cable 121 provides a pathway for the generated power to be transmitted to either storage devices or directly to a power grid. A small portion of generated power will be retained for use by the support structure when the stored power of a back-up system is required. The point of connection of transmission cable 121 could be located anywhere throughout submerging spar 102's surface, depending on the functional requirements of the installation. Transmission cable 121 is shown with cable float 122 and cable weight 123. Each is employed to manage transmission cable 121's position underwater.
The control of all actions of this invention may be accomplished automatically by utilizing a computerized control system, or manually. Each mode may be designed to function from a remote location or on-board. Further, control may be a combination of some automatically activated devices while other actions are initiated manually. An installation also may be designed to be fully automatic with manual over-ride capability in part or whole. For efficiency, it may also be preferred to install a single system of sensors and automatic control that operates a cluster or group of support structures, if the systems can be designed to insure the sensors' data is both accurate and pertinent to each of the support structures that are within the cluster.
FIG. 2 is an elevation view of a deployed blade web 200, utilized in the embodiment shown in FIG. 1. (This blade web 200 is stored on FIG. 1 within blade web storage cabinets 114, in its folded and stored position.) The blade web 200 is stored during normal turbine operation within blade web storage cabinets 114 positioned behind the blade rotor. Deployment occurs in two phases. First, fluid is injected into 12 primary tubes 201 configured as spokes equally positioned. The primary tubes 201 serve to pull the web structure out of the storage containers and to fully extend the blade web 200 and the web's outer ring 202 in preparation for phase 2. Phase 2 is the second injection of liquid into the secondary feed tubing 203 which fills and stiffens the remaining web configuration. The blade web 200 is fully deployed when the bracing structure 204 in the shape of concentric circles of cross-braced segments between each of the primary tubes 201 is injected with liquid. The web extends from blade rotor 205 to the tips of turbine blades 206. The impact of wave action is absorbed by the blade web rather than the blades during descent. The blade web 200 is collapsed and returned to the blade web storage cabinets 114 following the reverse sequence as the injected liquid is withdrawn. The following elements are indicated to provide context: top portion of submerging spar 102, nacelle 120, and extendable bows 115 and sensor buoy 112.
FIG. 3 shows Embodiment #2 of the invention. This embodiment is identical to that shown in FIG. 1, with five modifications. Those five additional elements are staging base 301, staging tendons 303, outriggers 305, travel void 304, and mooring tendons 306. These additions are not critical to the invention's functioning; rather, they are enhancements to the invention's performance.
Staging base 301 is connected to the anchoring system, in this embodiment, a dead weight anchoring base 100, by staging tendons 303. Staging base 301 is a highly buoyant structure, which consists primarily of buoyancy tanks 302. Staging base 301 is incorporated into foundation zone 1 to reduce the dead weight of staging tendons 303. It also serves as a docking station for the support structure, to facilitate complete replacement, if necessary, of the support structure and operative device. Staging base 301 may be of any size and shape that accommodates the described purposes. Staging base 301 may incorporate additional support functions such as power storage tanks, as the particular installation requires. Staging base 301 contains travel void 304, which is centrally located and of adequate size to accommodate the passage of the lower portion of submerging spar 102, down through the body of staging base 301. Travel void 304 allows staging base 301 to be positioned as close to mean sea level 5 as possible, which in turn facilitates easier access to staging base 301.
Outriggers 305, shown connected to submerging spar 102, increase the length of the lever arm to which each of the mooring tendons 306 is attached. This added element improves the control of the position and attitude of submerging spar 102 and operative device 113, as the tension in any particular mooring tendon 306 is adjusted.
FIG. 4 shows the third embodiment of the invention, in the extended position. Embodiment #3, as depicted in FIG. 4, is an offshore support structure which has been adapted to support a Wind Amplifier Rotor Base or WARP (by ENECO of West Simsbury, Conn., USA). The operative device direct-water-contact-protection strategy of this embodiment is to fully encapsulate the operative device. FIG. 4's depiction of this embodiment of the invention is complete with the exception of the anchoring system, mooring tendons, and the lower portion of the staging base. For illustration, these will be assumed to be the same as shown in FIG. 3.
The portion of foundation zone 1 that is shown in this figure includes the upper portion of staging base 401, mooring tendons 402, and fixed base 403. The characteristics and functions of staging base 401 in this embodiment have been previously described in connection with the detailed descriptions of staging base 301, which is a part of FIG. 3. Mooring tendons 402 are each attached to and are put in tension by a highly buoyant fixed base 403. Each mooring tendon 402 is connected from a point on staging base 401 to a point on fixed base 403 above. Fixed base 403 is positioned a safe distance below mean sea level 5 and remains relatively static during all operations of the support structure.
The following components comprise fixed base 403: buoyancy tanks 404, hydraulic pumps 405, expandable air vessels 406, variable volume membrane 407, sea water inlets 408, ballast tanks 409, guide well 410, stop rim 411, outriggers 412, and gyroscope 413. Other elements are position sensors 414.
Fixed base 403 includes a relatively central guide well 410, which is an open cylindrical tube running vertically completely through fixed base 403. Fixed base 403 is highly buoyant, to place great tension on multiple mooring tendons 402 in order to maximize the structure's stability.
Buoyancy tanks 404 are sealed tanks of compressed air that provide the constant source of lift to achieve substantial buoyancy of fixed base 403. Hydraulic pumps 405 provide the motive force to alter expandable air vessels 406. Expandable air vessels 406 serve to adjust and position fixed base 403 during installation and replacement. They also trim fixed base 403 as needed.
Variable volume membrane 407 maintains a watertight seal between sea water inlets 408 and expandable air vessels 406. Ballast tanks 409 serve to lower the center of gravity of fixed base 403. Guide well 410 serves to direct and control the movement vertically of travel tube 416 (described as part of active zone 2, below). Stop rim 411 is located at the top of guide well 410. It contains position sensors 414 to confirm the proper seating of travel tube 416 at the end of its periodic descent.
Outriggers 412 increase the horizontal span between staging tendons 402. Gyroscope 413, an equipment sensor, provides readings of fixed base 403's vertical position.
Active zone 2 consists of travel tube 416, which is made up of ballast tank 417, depth sensor 415, variable volume membrane 418, sea water inlets 419, expandable air vessel 420, hydraulic pump 421, hydraulic piston 422, buoyancy tanks 423, hydraulic telescoping tower 424, sealing rim 425, wave sensor grid 426, full extension seal 427, storage chamber 428 and position sensor 430.
Travel tube 416 harbors operative device 429 when submerging down through the open guide well 410 of fixed base 403. Travel tube 416 is sized to receive and enclose operative device 429 and provide the motive force for its own vertical movement.
Wave sensor grid 426 is an environmental sensor which constantly monitors wave height and direction and provides data identifying the height of sealing rim 425 above mean sea level 5.
Travel tube 416 moves vertically within guide well 410 and therefore passes through fixed base 403, so that sealing rim 425, which is the top edge of travel tube 416, upon reaching full extension, is significantly above mean sea level 5. The interior of the sealing rim 425 is equipped with position sensor 430 to confirm the seating of full extension seal 427. Upon descent, travel tube 416 moves in the opposite direction until it comes to rest in its fully submerged position, which occurs when sealing rim 425 is seated against stop rim 411.
Within the bottom-most portion of travel tube 416, ballast tank 417 serves to lower the center of gravity of travel tube 416. Depth sensor 415 is located on the exterior of ballast tank 417, and constantly monitors the vertical position of travel tube 416. Variable volume membrane 418 maintains a watertight seal between sea water inlet 419 and expandable air vessel 420. Hydraulic pump 421 provides the motive force to alter expandable air vessel 420 and to operate hydraulically telescoping tower 424. Buoyancy tanks 423 are sealed tanks that provide the majority of the buoyancy needed for travel tube 416 to reach its extended position. The remaining buoyancy required to raise travel tube 416 to its extended position is provided by expandable air vessel 420. Expandable air vessel 420 is sized so that the manipulation of its volume will be able to achieve all required movement, acceleration, and deceleration of travel tube 416. Travel tube 416 is made to rise by increasing its buoyancy, which is in turn accomplished by directing hydraulic pump 421 to extend hydraulic piston 422, and thus increase the volume of expandable air vessel 420, increasing travel tube 416's buoyancy.
Hydraulic telescoping tower 424 raises and lowers operative device 429 in and out of storage chamber 428 of travel tube 416. Storage chamber 428 serves to provide for the storage of operative device 429 during submersion. Full extension seal 427 is configured to compress against sealing rim 425 as operative device 429 reaches the fully extended position. The proper position of full extension seal 427 against the underside of sealing rim 425 is indicated by position sensor 430, located beneath the inner collar of the sealing rim 425. This is to create a water-tight seal of evacuated storage chamber 428.
Primary zone 3 is comprised of operative device 429, hatch cover 433, sensor buoy 434, computer 435, position sensors 436 and communication transmitter/receiver 437.
Operative device 429 is a Wind Amplifier Rotor Base or WARP. This consists of a vertically stacked grouping of two opposing turbines 431, rotating to the wind within a modular wind foil 432. Hatch cover 433 is positioned at the top of operative device 429 and is shaped to provide water-tight storage of sensor buoy 434, computer 435 and communication transmitter/receiver 437. The bottom edge of hatch cover 433 is fitted to create a water-tight seal against sealing rim 425, to complete the encapsulation of operative device 429 as it completes its descent into storage chamber 428. Position sensors 436, about the bottom of hatch cover 433, are to confirm contact and sealing. Upon encapsulation of operative device 429, computer 435 initiates the submerging sequence of travel tube 416. Sensor buoy 434, housed in hatch cover 433, functions as described in previous embodiments.
Transmission line 438 extends from fixed base 403 to staging base 401 and avoids entanglement by use of transmission weight 439.
FIG. 5 shows an enlarged, simplified partial cut-away view of the top potion of travel tube 416 and guide well 410 of Embodiment #3. Operative device 429, hydraulic telescoping tower 424, and hatch cover 433 are not shown in order to allow depiction of the inner relationship and configuration of guide well 410 and travel tube 416. Other parts that are shown, to provide context, are stop rim 411, position sensors 414, sealing rim 425, wave sensor grid 426 and storage chamber 428.
Travel tube 416, as shown, is positioned just short of its fully submerged position.
Additional details of guide well 410, shown in this Figure, are guide rails 501. Additional details, shown on travel tube 416, are travel tube guides 502, guide rail locks 503, and wind foil guides 504.
Guide rails 501 are vertical, continuous elements, running the full height of guide well 410. They are located on the interior surface of guide well 410, and positioned in multiple locations equally spaced about the circumference of the guide well's 410 interior surface. Travel tube guides 502 are affixed to the exterior of travel tube 416 and engage guide rails 501 to direct and limit the vertical movement of travel tube 416. Incorporated into travel tube guides 502 are guide rail locks 503 which create friction against guide rails 501 when activated. Guide rail locks 503 slow the motion of travel tube 416, and upon full activation lock travel tube 416 into a fixed position.
Wind foil guides 504 are continuous, linear, protruding, non-abrasive elements about the circumference of travel tube's 416 interior surface. They are positioned to limit the horizontal movement of operative device 429, (not shown) when entering and exiting storage chamber 428.
To summarize the operation of the embodiment of the invention as reflected in FIGS. 4 and 5, hydraulic telescoping tower 424, with mounted operative device 429, extends and retracts through guide well 410, with the directional assistance of the surrounding wind foil guides 504. The uppermost surface of operative device 429 is fitted with hatch cover 433 which is fixedly attached. A corresponding double-sided sealing rim 425 is fixedly attached to the upper-most portion of travel tube 416. The support structure is caused to submerge by first retracting hydraulic telescoping tower 424. Hydraulic telescoping tower 424 is contracted until hatch cover 433 engages sealing rim 425, creating a water-tight seal. The motive force for travel tube 416 is created by directing hydraulic pump 421 to reduce the volume of expandable air vessel 420. Hydraulic telescoping tower 424 and rail guide locks 503 are controlled automatically by computer 435, in coordination with position sensors 436, and wave sensor grid 426, but may be, if desired, manually or remotely controlled. The upper surface of sealing rim 425 forms a water and air-tight seal against the bottom surface of the rim of hatch cover 433 to secure the operative device 429 prior to the travel tube 416 beginning its descent.
Conversely, the support structure is caused to extend by raising travel tube 416 within guide well 410, when depth sensor 415 indicates the desired elevation is obtained. The hydraulic telescoping tower 424 and then, in sequence, extending hydraulic telescoping tower 424 and, consequently, operative device 429. Travel tube 416 reaches its uppermost position within guide well 410, completing the support structure's transition to full extension, when full extension seal 427 makes sufficient contact with the underside of sealing rim 425.
FIG. 6 shows Embodiment #3 of the invention, in the fully submerged position. The components of this depiction of Embodiment #3 are identical to those shown in FIG. 4. The purpose of this figure is to show the changes that occur in the fully submerged position, as compared with the fully extended position (depicted in FIG. 4).
In this figure, operative device 429 has been retracted inside travel tube 416 and sealed water-tight by hatch cover 433. Travel tube 416 has dropped in its elevation, to a position beneath eighty feet below mean sea level 6. Expandable air vessel 420, located at the bottom of travel tube 416, has decreased in volume to provide the motive force to lower travel tube 416. That alteration was effected by the retraction of hydraulic piston 422, which simultaneously reduced the volume of air within the expandable air vessel 420, increased its volume of water through the sea water inlets 419 and expanded the variable volume membrane 418 which serves to limit the sea water's intrusion into expandable air vessel 420. Throughout this operation, it should be noted that fixed base 403 remains unmoved and highly buoyant.
One element that is newly shown in FIG. 6 is buoy lifeline 601. This provides control of sensor buoy 602 during deployment and recovery, as well as providing a data link between sensor buoy 602's data output and computer 435.
Referring back to FIGS. 1 through 6, it should now be apparent, to those skilled in the art, that a novel support structure, to be situated offshore or deep offshore with minimal cost, and having the ability to protect itself and its operative device by fully submerging, has been provided.
The preceding description is not to be construed as limiting in scope but rather as a representation of preferred embodiments of the present invention. In light of the above description and examples, various substitutions and modifications will now become apparent to those skilled in the art. For example, where expandable tanks have been illustrated, more conventional flood tanks could be used. Of course, submerging spar 102, or travel tube 416, may be made to rise and lower by other means. For instance, by means of transferring air or altering the level of buoyancy in reverse proportion between an independent but connected substantial element and the support structure simultaneously, causing one to be the motive force for the other's vertical movement. Similarly, a supporting structure in accordance with the invention may drive its telescoping tower 424 by a means other than the hydraulic system shown in FIG. 4, such as a counter weight system. Accordingly, the scope of the invention should be determined by the spirit and scope of appended claims and applicable legal equivalents.

Claims

1. A submerging support structure for protecting an operative device situated in the sea offshore, comprising: a relatively stationary foundation zone in the lowest-most portion of the support structure and connected to the sea floor; a mid level, active zone secured to said foundation zone, said active zone substantially functioning to provide motive forces for repositioning at least the operative device above or below the sea surface; and a primary zone in the uppermost portion of the support structure from which the operative device is deployed, said primary zone and operative device being repositioned by the active zone according to the presence of hazardous conditions.

2. The submerging support structure of claim 1 further comprising a network of both sensors and equipment controls, connected to a computer system programmed to reposition at least the operative device upon specific signals from the sensors according to preprogrammed response sequences.

3. The submerging support structure of claim 1 further comprising a communication network, said network connected between the computer of claim 2 and remote environmental input devices, and support structure monitoring and alternate control capabilities, such that the support structure may be moved above and below the sea surface automatically or by degrees of remote command.