1. Field of the Invention
This invention relates to harvesting kinetic energy of rivers and ocean tidal currents in shallow waters and it is based on the utilization of Darrieus type turbines.
2. Discussion of Prior Art
The most of the known installations for harvesting kinetic energy of the water streams, which are originated by tides or rivers in shallow waters, are of two types. One type is using Propeller-turbines with horizontal axis of rotation the other type is using Darrieus hydro-turbines with vertical orientation of their axis of rotation. The specific of Darrieus hydro-turbines is that they rotate always in one direction, regardless of water flow direction. The propeller-turbines, in case of their application for harvesting tidal energy, have to have special provisions to accommodate 180° change in the direction of water flow.
The propeller-turbines type installation have horizontal axis of rotation and usually located bellow water level on the sea or river bottom. Thus allows timber rafting and ice drifting to flow above them and also to minimize effect of waves actions on the their structures. However, since the multiplicator and generator are on the same axis with propeller and are located underwater, this requires placing them in hermetic capsule. The need for hermetic capsule, besides significant complication of performing regular maintenance, creates the possibility of it some day flooding. Thus makes the systems requiring use hermetic capsule not reliable for a prolong use.
Most of installations with Darrieus type turbines have their axis of rotation oriented vertically, thus allows locating their multiplicator and generator above water and by this simplifying the process of their maintenance. Also advantage of Darrieus turbine versus propeller-turbines is that in cases when depth of water limits the size of turbine the square shape of Darrieus turbine has about 20% larger area. These advantages in many cases outweigh he drawback of being obstacle to timber rafting and ice drifting.
The Darrieus type turbine that was patented in 1927 (U.S. Pat. No. 1,835,018) was widely used for harvesting kinetic energy of the wind. Only in the beginning of 1980ries the Canadian Company Nova Energy, Ltd. pioneer used of Darrieus turbines for harvesting energy of water streams. Their basic design (see website www.bluenergy.com) utilizes vertically oriented turbine into a frame that is connected to the sea bottom. This limits their use to shallow water straits and rivers.
The other company that presently uses Darrieus turbine in their projects is GCK Technologies Inc. Its systems are described in the U.S. Pat. No. 6,036,443, issued to Alexander Gorlov. Specific of this patented turbine is in the use of helical blade instead of conventional straight blade of Darrieus turbine. The goal of using helical blade is to provide to turbine self-staring capability. Presently all 2 and 3 blades Darrieus turbines used for harvesting wind energy and converting it to electricity are started by a motor. Since this motor, after turbine reaches synchronous speed of AC power in the grid, starts to operate, as generator the absence of self-starting capability is not a problem at all for systems supplying electricity in power grid.
Installations for harvesting kinetic energy of water streams shown in Gorlov U.S. Pat. No. 6,036,443 are located underwater, thus making them vulnerable for flooding and are not accessible for frequent maintenance. Gorlov also came up with submerged floating system that can be anchored in deep waters to sea bottom by mooring lines. This floating system is described in article “Helical Turbines for the Gulf Stream: Conceptual Approach to Design of a Large-Scale Floating Power Farm”, see Marine Technology, Vol. 35, July 1998, pp. 175-182.
The U.S. Pat. Installation for Harvesting Ocean Currents (IHOC) No. 6,856,036 B2, issued on Feb. 15, 2005 to Sidney Belinsky, who is also author of instant invention, illustrates application of vertically oriented Darrieus turbine for harvesting energy of ocean currents in deepwaters. It also illustrates use of funnel in combination with turbine, which increases the speed of water passing through the turbine. The turbine wheel design consists of 3 two-straight blade turbines staggered on 120 degrees and assembled on one shaft. Thus forms a six-blades turbine that has the self-starting capability and delivers smoother torque distribution during one rotation. At the same time two-blade Darrieus turbine have higher efficiency that 3-4 blades turbines used by Blue Energy Canada and GCK Technology, Inc.
The main objective of IHET invention is to create a more efficient and more practical system for harvesting kinetic energy of ocean tides and rivers in shallow waters, by overcoming the major drawbacks of the all presently known systems for harvesting tidal and rivers current kinetic energy.
The instant invention IHET approaches the first drawback by locating several Darrieus turbines on one line (shaft) parallel to sea bottom and perpendicular to the water flow direction. By using 90 degrees gearbox on the sea bottom it becomes possible to orient rotation of output shaft vertically and by this allowing location of generator and all auxiliary systems above water level. Thus will allow transmitting rotation of many turbines through one gearbox and one generator, thus significantly reducing capital cost per KW/Hour of electricity generated.
The second drawback (increase in maintenance cost) the instant invention IHET approaches by reducing the number of gearboxes and generators to be served, as the result of increasing number of turbines rotating one gearbox and one generator. It also provides a means for cleaning turbines blades surface from growth on their surface in a semi-automated mode by a special machine, which besides reducing maintenance cost also would allow to keep efficiency of turbine closed to initial condition. To simplify maintenance of 90-degree gearbox, which is positioned underwater, a special provision is made to complete all required routine maintenance of the gearbox (regularly changing oil and oil filters) from the powerhouse located above water.
The instant invention is demonstrated by two Embodiments.
Embodiment I demonstrates application for installation in places far away from coastal lines. Embodiment II demonstrates application for it installations in straits and rivers, where string of underwater turbines are located perpendicular to water flow and one end of their common shaft is coming to the strait or river shoreline.
Both Embodiments have similar design of their submerged frames, inside of each are located several Darrieus turbines interconnected to each other through their shafts and arranged in line. The underwater frames are installed parallel to sea bottom and perpendicular to direction of water movement. They have at least two points by which they are connected to sea bottom and means for undertaking current force. Depending on the soil conditions the instant invention illustrates two options for case with soft soil and case with hard soil. Embodiment I illustrate case with soft soil at which the current force is undertaken by at least 4 piles driven in sea bottom. Embodiment II illustrate case with hard soil at which the current force is undertaken by at least 4 anchoring lines and 4 gravity anchors.
Sections F-F; G-G; and H-H show how the two-blade turbine wheels are staggered in a plane on 120°.
Generator 140 is connected to the top of support tower 105 by a frame 144 and through a rigid coupling 148 and vertical shaft 149 with two groups of Darrieus turbines 114 through a 90-degrees gearbox 142.
The gearbox 142 includes housing 158 that contain two sets of planetary gears 160, located symmetrically to gearbox 142 centerline. Each of the both gear sets 160 has input shaft 161, which through universal joint 164 is connected with one of the Darrieus turbines 114 shafts 140 or 141. Each input shaft 161 has a housing 163 in which a seal 164 and compression bushing 165 are located. Also housing 163 has a cavern 166 to which pipe 168 with compressed air is connected. Each set of planetary gears 160 has output shaft 162 with bevel gear 187, which are engaged with central bevel gear 189, which is located in the middle of 90-degrees gearbox 142 and is connected to vertical shaft 149.
The system 150, for keeping air pressure inside 90-degrees gearbox above the hydrostatic pressure of water on the sea bottom, includes internal space of a vertical column 354 and internal space of 90-degrees gearbox 142. The vertical column 154 has on its upper part a seal 164 with compression bushing 165 and it is connected by its lower part to housing 158. The system 150 consists of: compressor 169, accumulator 170, accumulator 171, pipeline 172 and pipeline 167. Pipeline 172, which is connected to accumulator 170, supplies compressed air to internal compartments of vertical column 154 and 90-degrees gearbox 142. Pipeline 167, which is connected with accumulator 71, supplies compressed air to caverns 166.
The remote operating lubricating system 152 for cooling, changing and cleaning oil in the 90-egrees gearbox 142 consists of a pump 174, a filter 176, heatexchanger 178 and pipeline loop consisting of suction line 182 and pressure line 183. The suction line 182 and pressure line 183 valves 185, which allow emptying entire system from old oil and refilling it with fresh oil.
The turbine cage 220 (
The turbine wheel 234 consists of pair of blades 244, spokes 246 and central shaft 248 with a pair of centering rings 250. The bearing-support arrangement 238 consists of support beam 252 and pair of rollers 254 engaged with centering ring 250 of turbine wheel 234. Connecting coupling 240 consist of three wedge-centering units 256 equally distributed along the perimeters of turbine wheel central shaft 248 and intermediate shaft 242. Each wedge-centering unit 256 consists of two blocks 258 with square opening and one square wedge 260, that fits into openings in blocks 258.
Each of the ends supports 212 and 214 (see
The 90-degrees gearbox 342 includes housing 358 that contain a set of planetary gears 360. The planetary gear set 360 has input shaft 361, which through universal joint 276 and short shaft 274 is connected with group of the Darrieus turbines located in frame 203. Each input shaft 361 has a housing 363 in which a seal 364 and compression bushing 365 are located. Also housing 363 has a cavern 366 to which pipe 368 with compressed air is connected. The set of planetary gears 360 has output shaft 362 with bevel gear 387, which is engaged with horizontal bevel gear 389 and through it is connected to vertical shaft 349.
The system 350, for keeping air pressure inside 90-degrees gearbox above the hydrostatic pressure of water on the sea bottom, includes internal space of a vertical column 354 and internal space of 90-degrees gearbox 342. The vertical column 354 has on its upper part a seal 364 with compression bushing 365 and it is connected by its lower part to housing 358. The system 350 consists of: compressor 369, accumulator 370, accumulator 371, pipeline 372 and pipeline 367. Pipeline 372, which is connected to accumulator 370, supplies compressed air to internal compartments of vertical column 354 and 90-degrees gearbox 342. Pipeline 367, which is connected with accumulator 371, supplies compressed air to cavern 366.
The remote operating lubricating system 352 for cooling, changing and cleaning oil in the 90-degrees gearbox 342 consists of a pump 374, a filter 376, heatexchanger 378 and pipeline loop 380, having suction line 182 and pressure line 183. The pipeline loop consisting of suction line 382, pressure line 383 and valves 385, which allow emptying entire system from old oil and refilling it with fresh oil.
The blade-cleaning machine 407 (
This application is related to provisional application Ser. No. 69/585,695 entitled “System for harvesting kinetic energy of water streams in shallow waters” filed Jul. 6, 2004, which is incorporated herein in reference.
Number | Date | Country | |
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60585695 | Jul 2004 | US |