Patent Application
20200400113
Embodiments of the technology relate, in general, to hydroelectric technology, and in particular to hydroelectric systems that can be used to generate power from low dams and other fluid sources.
The present disclosure will be more readily understood from a detailed description of some example embodiments taken in conjunction with the following figures:
Renewable energy resources are gaining global attention due to depleting fossil fuels and harmful environmental effects associated with their usage. Hydro, wind, solar, biomass and geothermal energies form the bulk of renewable energy sources; among which hydro power may offer one of the more sustainable propositions. Traditionally, hydro power has accounted for the bulk of the renewable energy production in the United States. Low dams, also sometimes called low-head dams or weirs, are vertically oriented short dams that can be placed in water channels. Low dams can be used to maintain a minimum water depth for water supply to a municipality or for flood control purposes. The reservoir-pool of water created by low dam is often used to supply cooling water for industrial applications. Low dams have also been constructed to raise the water level to a sufficient height to support recreational boating and are in some cases referred to a Lake Dams.
Embodiments of a hydroelectric system for a dam, including a low head dam can include a module including a protective housing that can include a Coanda-effect screen, a turbine housing retained within the protective housing, the turbine housing including an upper inlet portion at a first end, a substantially tubular portion, and a lower outlet portion at a second end, the upper inlet portion being positioned above the lower outlet portion, a turbine retained at least partially within the turbine housing, the turbine including a plurality of blades coupled with a central shaft, and a fluid pump, the fluid pump being coupled with the central shaft, where the fluid pump is configured to pump a high pressure fluid, a fluid circuit, the fluid circuit including piping, where the high pressure fluid is retained within the piping, and a shoreline generator, the shoreline generator being coupled with the fluid circuit, where the offsite generator is driven by the high pressure fluid that is pumped by the fluid pump in response to the rotation of the turbine.
Embodiments of a method for operating a hydroelectric system can include providing a hydroelectric system, where the hydroelectric system can include a module having a protective housing anchored to a downstream face of a dam, a turbine housing retained within the protective housing, the turbine housing including an upper inlet portion at a first end, a substantially tubular portion, and a lower outlet portion at a second end, the upper inlet portion being positioned above the lower outlet portion, a turbine retained at least partially within the turbine housing, the turbine including a plurality of blades coupled with a central shaft, and a fluid pump, the fluid pump being coupled with the central shaft, where the fluid pump is configured to pump a high pressure fluid, a fluid circuit, the fluid circuit including piping, where the high pressure fluid is retained within the piping, and a shoreline generator, the shoreline generator being coupled with the fluid circuit, where the shoreline generator is driven by the high pressure fluid that is pumped by the fluid pump in response to the rotation of the turbine. The method can include positioning the module adjacent a low head dam, where a fluid is flowing over the low head dam, rotating the turbine with the fluid flowing over the low dam, pumping the high pressure fluid with the fluid pump in response to the rotation of the turbine, and driving the shoreline generator with the high pressure fluid to produce electricity.
Embodiments of a hydroelectric system for a dam, including a low head dam, can include a module that can be anchored to a downstream face of a dam, the module including a housing means retained within the protective means, a turbine means retained at least partially within the housing means, and a pump means operatively coupled with the turbine means, where the pump means is configured to pump a high pressure fluid, a fluid circuit associated with the pump means, and a generator means coupled with the fluid circuit.
Various non-limiting embodiments of the present disclosure will now be described to provide an overall understanding of the principles of the structure, function, and use of the apparatuses, systems, methods, and processes disclosed herein. One or more examples of these non-limiting embodiments are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that systems and methods specifically described herein and illustrated in the accompanying drawings are non-limiting embodiments. The features illustrated or described in connection with one non-limiting embodiment may be combined with the features of other non-limiting embodiments. Such modifications and variations are intended to be included within the scope of the present disclosure.
Reference throughout the specification to “various embodiments,” “some embodiments,” “one embodiment,” “some example embodiments,” “one example embodiment,” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with any embodiment is included in at least one embodiment. Thus, appearances of the phrases “in various embodiments,” “in some embodiments,” “in one embodiment,” “some example embodiments,” “one example embodiment,” or “in an embodiment” in places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.
Described herein are example embodiments of apparatuses, systems, and methods for hydroelectric power generation. In some embodiments, a hydroelectric power generator that can be deployed at dams having a generally flat downstream face is disclosed. In example embodiments, a hydroelectric power generator that can be deployed at low dams is disclosed. In some embodiments, the hydroelectric generator can produce power from both the pressure differential created by a low dam as well as the flow velocity of the water channel. In some embodiments, the hydroelectric generator can be self-contained in a submersible module which can further be a hydraulic-hydrokinetic power production module (“HPPM”). In some embodiments, a system of hydroelectric generator systems or HPPMs can be deployed in a water channel to capture a larger amount of energy from the channel than one generator module can capture. In some embodiments, the hydroelectric generator module can generate electricity during the lowest flow-rate condition of a water source. In certain embodiments, the system can include a hydroelectric generator that can efficiently generate power at low dams without ecologically destabilizing a water channel or requiring expensive installation.
The examples discussed herein are examples only and are provided to assist in the explanation of the apparatuses, devices, systems and methods described herein. None of the features or components shown in the drawings or discussed below should be taken as mandatory for any specific implementation of any of these the apparatuses, devices, systems or methods unless specifically designated as mandatory. For ease of reading and clarity, certain components, modules, or methods may be described solely in connection with a specific figure. Any failure to specifically describe a combination or sub-combination of components should not be understood as an indication that any combination or sub-combination is not possible. Also, for any methods described, regardless of whether the method is described in conjunction with a flow diagram, it should be understood that unless otherwise specified or required by context, any explicit or implicit ordering of steps performed in the execution of a method does not imply that those steps must be performed in the order presented but instead may be performed in a different order or in parallel.
Example embodiments described herein can beneficially capture energy from water channels during all flow conditions of the channel and can operate without detrimental effect to the water channel's ecology or environment. For example, the flow rate, appearance, and usability of the water channel by boats and wildlife can remain unaffected or substantially unaffected by operation of the generator modules or pump modules described herein. Traditional hydroelectric generators, in contrast, can cause fish kill due to the high speed at which their turbines operate. Additionally, the present hydroelectric generators modules and pump modules can be easily installed with common equipment. The generators and modules can also be installed in such a way that they do not interfere or compromise the purpose of a dam, including a low dam. Such a configuration can generate pollution-free electricity. The installation of HPPMs on the downstream side of an existing low dam may have no more of an environmental effect than that of the low dam itself. The hydraulic boils created at the foot of low dams are notorious for entrapping canoers, kayakers, and small boats. Embodiments described herein can mitigate and minimize the hydraulic boils such that low head dam safety improvements can be provided.
Referring now to
The generator module 10 can have a protective enclosure 16 that can protect internal components as well as wildlife and recreational users of waterways. The protective cover 16 can be configured to make the generator module 10 look like a part of the low dam 50 to provide an aesthetically pleasing appearance. In one example, the protective enclosure 16 can be concrete. In another example, the protective enclosure 16 can be metal. In another example, the protective enclosure 16 can be a non-metallic composite material. The protective enclosure 16 can include a first opening 17 protected by an upstream grate 18 and a second opening 19 protected by a downstream grate 20 that can prevent debris from damaging the turbine and generator located inside. The first opening 17 can allow head water from the water channel to flow through the generator module 10 to produce electricity. Head water can exit the generator module 10 through the second opening 19 after flowing through the internal turbine 22 (
Any suitable protective housing 16 is contemplated. The protective housing 16 can substantially surround the turbine housing 27 (
The protective housing 16 can have a protective housing height PH and a protective housing width PW as depicted in
The generator module 10 can have any suitable structure for a central shaft 26. The central shaft 26 can be designed in sections from about 4 feet to about 10 feet in length, for example, along the shaft axis allowing each section to be constructed with the turbine blades 29 as a module and aligned and fitted in a turbine housing 27 with a turbine housing height TH that is a dimension sufficient to provide clearance for turbine blades 29 and fit without protective housing 16 taking into account the thickness of the material of the turbine housing. The turbine housing 16 can also have a turbine housing width TW that can range from about 6 feet to about 60 feet, for example. In an embodiment the turbine housing 27 is at least partially tubular about an outer surface, as depicted in
The turbine 22 can be housed within the turbine housing 27, which can include a substantially tubular portion 32, an upper inlet portion 34, and a lower outlet portion 36. The substantially tubular portion 32 can be sized to accommodate any suitable turbine 22. It will be appreciated that the tubular portion 32 is described by way of example only, where any suitable shape is contemplated. The upper inlet portion 34 can include the upstream grate 18 and the lower inlet portion 36 can include the downstream grate 20. The upper inlet portion 34 can have any suitable size, shape, or configuration to direct the flow of fluid through the turbine housing 27 past the turbine 22. The upper inlet portion 34 can be substantially the length of the generator module 10, can be shorter than the length of the generator module 10, or can be wider or longer than the generator module 10 with a funnel (not shown) or other mechanism for drawing fluid into the turbine housing 27. The turbine housing 27 can include a plurality of upper inlet portions and a plurality of lower outlet portions having any suitable shape or configuration. In one embodiment, generator module 10 can have a flexible or pivotable protective enclosure 16 and/or turbine housing 27 such that the turbine housing 27 and/or protective enclosure 16 can be adjusted relative to the flow of water over the dam 50. For example, the turbine housing 27 can be a pivoting housing relative to the platform 12 to enable the upper inlet portion 34 to the turbine 22 to be at an optimal angle relative to the adjacent dam 50 and the flow of water. The adjustable or pivotable structure can be mechanically adjusted or, in one embodiment, can be associated with a controller that can automatically adjust the position of the structure based upon water flow, environmental conditions, or the like.
Turbine blades 29 can be fabricated from any number of different materials using any number of machining or forming processes. In each case, a mathematical formula based on anticipated flow rate at the specific installation site can be used to determine the optimal blade shape and size as well as the number of blades comprising the turbine 22 for maximum efficiency versus production costs, installation costs, and full life-cycle costs. Blade curvature and number of blades can be mathematically optimized using the blade element momentum (BEM) theory, for example, over the anticipated flow range for maximum power transfer efficiency and acceptable life cycle economic costs. The BEM theory is described in more detail in Hydrodynamic Design and Optimization of Hydro-Kinetic Turbines using a Robust Design Method, by Nitin Kolekar, et al., Proceedings of the 1st Marine Energy Technology Symposium, Apr. 10-11, 2013, Washington, D.C., which is herein incorporated by reference in its entirety. Factors such as number of blades, tip speed ratio, type of airfoil, blade pitch, and chord length and twist can be considered. Flow range can be considered for maximum power transfer efficiency and acceptable life cycle economic costs. Blades 29 can include metallic blades, such as aluminum blades, which can be plates, formed blades, cast blades, machined blades, bent blades, extruded blades, or the like, where such aluminum blades may be readily machineable and cost effective. Steel blades can be used that have high strength, low cost, and manufacturing familiarity. Brass or bronze blades can be used that can exhibit corrosion resistance. Non-metallic blades, such as carbon fiber composite and ceramic blades, can exhibit wear resistance and low life cycle costs. Plastics may have a low cost, high availability, and may be biologically inert, and can include HDPE, XLPE, recycled plastic, and laminates, singularly or in combination. It will be appreciated that any suitable combination of materials including wood, resins, plastics, metallic, and/or ceramic is contemplated.
Referring to
Referring to
Systems described herein can generate a certain minimum amount of power even in low flow rate conditions. In addition to installation on a low dam 50, a generator module 10 or pump module 110 can alternatively be installed in a water channel. In one embodiment, a generator module 10 or module 110, in this example, can still generate electricity from the flow rate of the water channel as a result of the low-speed efficiency of the turbine. The generator module 10 or module 110 can operate, for example, in any water channel that has a continuous or substantially continuous flow rate such as, for example, a river, stream, creek, or waste water treatment facility exit trough. Such a system can be useful to establish a minimum level of power production. This can be advantageous for the present system because renewable power sources are traditionally subject to a wide variability in minimum generation which can necessitate that utility companies maintain a large reserve of generating capacity. For example, a utility company that operates a wind farm may have to maintain a coal plant in ready status in case the wind farm becomes inoperable due to falling wind speeds. Power generated through the systems depicted herein may negate this issue by providing a base amount of power.
In one embodiment, a generator module or pump module, such as generator module 10 or module 110, can continue to generate electricity up to and during the infrequent period when tail water converges to the same level as head water, or zero head. Flow volume can continue to descend the crest of the dam during this period and this kinetic energy can be sufficient to generate appreciable amounts of electricity. Conventional pressure-driven hydroelectric designs may not generate any electricity during this period, which may minimize their overall efficiency and effectiveness.
In an embodiment, a generator module 10 or module 110 as described above can be mounted operationally on the downstream face of a dam, rather than at the base of a dam, as depicted in
Water flow F flows by gravity over the top of dam 50 and is directed down the face 52 of dam 50. The water flowing down the face 52 of dam 50 can impinge the upstream first opening 17 of generator module 10, with a first portion of water flow F1 entering the protective screen 26 (if utilized) and drive the turbine (not shown) of generator module 10, as described above. Some of the flow, including debris-laden water, fish, and other solids, can flow over and around generator module 10 in a second portion of water flow F2. Water flow portions F1 and F2 continue downstream once past generator module 10. In an embodiment, generator module 10 is located a distance D from the top of dam 50. Distance D can be any distance over which the water flowing over dam 50 has sufficient velocity to drive the turbine for the desired power output, referred to as a head distance. In general, distance D can be at least two feet from the top of dam 50, and can be any distance less than the length of downstream face 52 parallel to the water flow.
In an embodiment, a generator module 10 or module 110 as described above can have increased power production at the turbine when provided at the first opening 17 with an inlet screen 26 that takes advantage of the Coanda effect. Coanda effect is the phenomena in which a fluid flow attaches itself to a nearby surface and remains attached even when the surface curves away from the initial flow direction. In an embodiment, a generator module 10 or module 110 can also, or optionally, take advantage of a Tyrolean screen. A Tyrolean screen can consist of either parallel rods or a perforated plate, installed parallel to the flow direction over at least a portion of the protective housing width PW of the flow F into a generator module 10 (or module 110). In an embodiment, a generator module 10 can incorporate Coanda effect screens and Tyrolean screens. In an embodiment, water flow F flows through a Tyrolean screen having rod materials, dimensions and spacing appropriate for the location, and then the water that clears the Tyrolean screen can flow to a Coanda effect screen for further flow separation prior to a portion of the flow F1 driving the turbine 22.
As depicted in
In addition to potentially significantly increasing the fluid flow into the turbine 22, a wedge-wire Coanda-effect screen or Tyrolean screen can be generally self-cleaning and can provide a filter for preventing fish and debris from entering turbine 22. Wedge-wire Coanda-effect screens take advantage of the Coanda effect by utilizing individually wedge-shape (in cross-section) wires oriented relative to the fluid flow F so as to enhance redirection of flow F to first flow F1 into and through turbine 22. Such wedge-shape wires are depicted schematically in
Wedge wires 58 can be arranged in regular, parallel, spaced relationship, with each wedge wire 58 having a wire width WW measured at the “top” of the wedge and a wire height WH measured from the top to the trailing edge “point” as depicted in
In general, the Coanda effect causes flow to remain attached to the top surface of each wire, thus enhancing the shearing action that directs water to flow F1 into turbine 22. The enhanced shearing can be controlled according to predetermined design criteria by modifying any or all of the wedge angle (i.e., the angle to the trailing edge “point” of the wedge wire in cross section), the tilt angle WA, wedge wire width WW, and wedge wire spacing WS.
A Coanda-effect screen 56 can be affixed to first opening 17 so that relatively closely spaced and angled wedge-wires direct water from flow F into first opening 17 as flow F1, while filtering, so to speak, debris, fish, and other solids out of first opening 17, being redirected over generator module as flow F2. A Coanda-effect screen 56 can be affixed to first opening 17 on a generator module 10 or module 110 anchored either the base of a dam as shown in
Further, in accordance with principles of the Coanda-effect, the Coanda-effect screen 56 can have an overall curvature perpendicular to the flow F from dam 50 that can enhance flow F1 into and through turbines 22. As shown in
In an embodiment, as depicted in
As depicted in
The foregoing description of embodiments and examples has been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the forms described. Numerous modifications are possible in light of the above teachings. Some of those modifications have been discussed, and others will be understood by those skilled in the art. The embodiments were chosen and described in order to best illustrate principles of various embodiments as are suited to particular uses contemplated. The scope is, of course, not limited to the examples set forth herein, but can be employed in any number of applications and equivalent devices by those of ordinary skill in the art. Rather it is hereby intended the scope of the invention to be defined by the claims appended hereto.
| Number | Date | Country | |
|---|---|---|---|
| 62726638 | Sep 2018 | US |
