Patent Application
20190234372
This application claims the benefit of U.S. patent application Ser. No. 14/998,046, filed on Dec. 24, 2015.
Power demands are increasing globally at the same time that concerns over pollution and unrenewable and unsustainable sources of power are rising. One source of energy that has been considered is the ocean. Various concepts have been considered, including ocean thermal energy, wave energy conversion, and tidal flow energy conversion. Harnessing energy from the ocean, however, must overcome significant design and implementation the production of electricity from the tidal flow of ocean tributaries.
Historically tidal power has been viewed as a viable solution for renewable energy because tidal flows are driven by the gravitational interaction between the Earth and Moon; this source of energy is likely inexhaustible and therefore is an extremely attractive potential solution to renewable and sustainable energy concerns. Tidal stream generators make us of the kinetic energy in the tidal movement of bodies of water. There are various designs of tidal stream generators, but they suffer from mechanical losses and fail to efficiently capture the available energy.
The production of energy from tidal flow from ocean tributaries requires the solution of several problems. First, it is necessary to design impeller blades that provide the maximum surface at 90 degrees to the current flow for maximum efficiency and the greatest power output. Utilizing designs that constantly expose a large surface area while maintaining a 90 degree aspect to the current flow—and thus to the maximum force of a moving current—is a difficult problem but one that, if solved, provides the greatest potential capture of kinetic energy contained in tidal flows. Second, the impeller housing must be constructed in such a manner as to reduce the wear from exposure to moving salt water. Salt water alone is corrosive but in an environment where a mechanism relies upon moving salt water, the corrosive effects can be multiplied along with wear and tear from the movement of salt water across exposed surfaces. The salts and particulate matter carried in seawater increases the erosion naturally caused by water flowing across surfaces. This harsh environment can reduce the lifetime of a device. Therefore, any tidal stream generator must take into account the destructive environment, and be designed to provide maximum protection from the corrosive elements of a salt water environment and have the mechanical and electrical systems contained in a closed container, offering complete fire protection for the electric generator and other electronic component.
Third, it must produce a product that will supply a huge demand in the market place. The best use for the electricity could be used to manufacture hydrogen gas from salt water. Currently, the most common commercial hydrogen gas production process uses natural gas as the hydrogen source. This process is expensive and the by products are a pollution problem. Having a power source located at a salt water source will allow the utilization of the power to efficiently produce hydrogen. Even without applying the power to the production of hydrogen, capturing the limitless kinetic energy of tides and converting to energy for commercial and/or household use is advantageous in and of itself.
The present invention is a process for using a high torque, extreme length impeller generator to generate electricity in a seawater environment by capturing tidal energy through the rotation of the impeller. In a preferred embodiment, the impeller blades are constructed of high strength, non-corrodible materials, such as carbon fiber. It is also preferred that the housing for the generators are made from the same or similar material. As designed herein, the carbon fiber generator housing is tubular, and may be constructed to be between fifteen and fifty feet in diameter, depending upon the chosen application and the location chosen for installation. Space and environmental considerations will dictate, in part, the size of the impeller generator. The generator can be stationary or mobile, depending upon the application. For example, the generator can be tethered to and operated from a barge or other platform.
The electrical generators and associated electrical equipment can be housed within a cylinder of differing materials, depending upon cost and other considerations. While carbon fiber may be a preferred material for the construction of the housing and related structures, other materials may be utilized as well. The ends of the carbon fiber cylinder are covered with a watertight cap, penetrated by a shaft through a watertight bearing fixture.
In one embodiment, it is preferable to have the cylinder filled with a pure nitrogen atmosphere, thereby negating any fire risk.
In operation, the invention takes advantage of Pascal's Law and that water density increases with depth. Pascal's Law provides that pressure acting on a confined fluid is transmitted equally and undiminished in all directions. As a result, the force on a particular portion of water in the water column is transmitted equally both vertically and horizontally. It is the horizontal force which is utilized by the present invention as the motive force for the one or more electrical generators contained in the present invention.
In an example, an impeller blade one (1) foot wide and one hundred (100) feet long at the depths of one foot, thirty three feet, and ninety-nine feet feels the following forces:
1 ft depth: H2O density of 64 lbs/ft3×100 ft2=6,400 lbs total force (3.2 tons)
33 ft depth: H2O density of 4,232 lbs/ft3×100 ft2=423,200 lbs total force (21.4 tons)
99 ft depth: H2O density of 8,462 lbs/ft3×100 ft2=846,200 lbs total force (423.2 tons)
With no movement of the water column, the force on either side of the impeller blade cancels each other out, resulting in a net zero movement. Moving water, however, produces a force equal to the water density multiplied by the surface area and the velocity of the water. At depth, therefore, the force exerted against a surface is many times the force exerted by stationary water at depth, and because the tidal flow causes the water body to move in a particular direction, the tidal force can be utilized to move an impeller.
What is needed, therefore, is an impeller-generator combination that is 1) specifically designed to efficiently capture the force exerted by the tidal movement of water and 2) that can be safely operated within a salt-water environment and be monetarily feasible.
Referring now to
The structural end cap 206 is penetrated by the conduit 103. The main impeller blades 201 are mechanically affixed to the end cap 206. The end cap 206 mechanically secures the main impeller generator body 204 to the end cap 206. The impeller blades 201 are secured to the conduit 103, such that when the device is in operation, rotation of the impeller blades 201 imparts rotational force on the conduit 103, thereby imparting rotational force on the generator shafts. The end cap 206 further contains a bearing 211 through which the conduit 103 passes, providing a watertight closure that still allows the conduit 103 to rotate when force is applied to the impeller blades 201. It will be understood that there are two (2) end caps 206, one at each end of the device housing 104. Each cap will contain a bearing 211. Watertight bearings are well known in the art, such as those used for ship and submarine drive shafts. The end cap 206, when viewed from the top down (
The structural conduit 103 has two functions. First, the conduit serves as an axle to which the shaft(s) of the generators 101 are attached, transmitting rotational force to the generators 101 to create electricity. The conduit 103 further provides a hollow interior portion in which electric cables, pipes, and other supporting structures enter the housing 104 in which the generators 101 are housed. The conduit further allows nitrogen gas to be sent into the housing 104 to provide an inert atmosphere, preventing fire within the housing 104.
The circular stop 205 keeps the main impeller blades 201 equal in distance from the centerline of the axle 103. Slot 207 is formed in the end cap 206, the slot 207 securing the impeller blades 201 with a structural flange 212. An impeller generator 204 is mechanically affixed to the end cap 206. A structural stop 205 maintains uniform distance from the stop 205 to the outboard edge 209 of each of the impeller blades 201.
Referring now to
The device, while shown with a structural foundation and rigid support secured to an ocean/water body floor, the invention as contemplated may also be mounted to and suspended from a vessel such that the device may be moved to achieve the best results in generating electricity from tidal flows. A vessel may include a barge, boat, or other watercraft.
This invention has been described in enough detail that one skilled in the art will be able to reproduce it without difficulty. There are modifications and equivalent structures and designs that can be incorporated without deviating from the scope of the invention.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14998046 | Dec 2015 | US |
| Child | 16198150 | US |
