Hydroelectric power plant

Abstract

The invention relates to a hydroelectric power plant system which generates electricity by utilizing gravitational potential energy of water flowing from a high position to a low position and converting the potential energy into electric energy. A power and hydroelectric power plant includes a vertical body of water, a water collector container, and a high capacity air supply.

Description

Technical Field

[0001] The present invention relates to a hydroelectric power plant system, which generates electricity by utilizing the gravitational potential energy of water flowing from a high place to a low place, and converts the potential energy into electrical energy. Background Art

[0002] The power output of traditional hydroelectric power plants relies primarily on the gravitational potential energy of water. As water flows from a higher reservoir through a downcomer called a penstock to a lower reservoir, it passes through a turbine-generator assembly to generate electricity. Water from the turbine outlet, or tailrace, then flows out to a lower reservoir or river. More recently designed hydroelectric power plants pump seawater to an upland reservoir, where it flows back through turbines to generate electricity. This cycle repeats—the seawater is pumped back to the higher reservoir, powered by renewable energy sources such as solar or wind power, ready for the next generation of electricity. This arrangement is known as a pumped-storage hydroelectric power plant or pumped gravity battery.

[0003] In pumped-storage hydroelectric plants, power generation capacity and duration are limited by the amount of water available in the upper reservoir and the height difference between the higher reservoir and the lower reservoir. This means that power output is dependent on both flow and height differences. In these pumped-storage plants, water is typically pumped to the upper reservoir during periods of low grid load, using excess power from the grid or other renewable energy sources such as solar or wind turbine systems.

[0004] Finding suitable locations for these pumped storage plants is also a challenge, as they require large reservoirs as close as possible to population or industrial areas without flooding farmland and forest reserves and causing environmental degradation. Various other reasons also need to be considered, including minimizing transmission line costs. Summary of the Invention

[0005] One of the features of the present invention is a submerged hydroelectric power plant that naturally provides a continuous flow of water from the higher water level to the lower water turbine for up to 24 hours, eliminating the need to pump water back to the higher reservoir in existing pumped-storage plants. The present invention aims to merge the lower and upper reservoirs into a single reservoir, eliminating the need to pump water from the lower reservoir to the higher reservoir. Instead, the present invention utilizes the incompressible nature of water molecules to overcome hydrostatic pressure, eliminating the need to transport these water molecules to the top. The water mass at the top of the penstock, above the penstock's inlet opening, possesses sufficient gravitational potential energy to push water into the penstock and flow downward.

[0006] Another feature of the present invention is a hollow, waterproof housing housing a conventional hydroelectric power plant. Once submerged in sufficient water depth and subjected to the associated water pressure, this conventional hydroelectric unit can operate and generate electricity. The housing is equipped with a water inlet located below the waterline at the top and multiple water outlets at the bottom. The housing also has openings to the atmosphere for ventilation and mechanical maintenance access. The housing can be constructed of steel, concrete, and suitable plastic materials and designed to withstand corrosive seawater and hydraulic pressure requirements. The housing's anchoring can be secured to a solid base on the seabed or the bottom and / or sides of a lake. If it floats on the water, it can be tied to a fixed anchor depending on the geographical conditions of the installation site. If designed with the mobility and buoyancy of a ship or barge, a suitable expandable form, and internal self-propelled water machinery, it can be used as a secondary vessel for cargo and passenger transport.

[0007] A further feature of the present invention is that it can be modularized so that the height difference between the water inlet and the turbine can be increased to improve the power generation capacity. In addition, the lower part where the water storage tank is located can be arranged horizontally to adapt to the available water depth and space at the installation site.

[0008] Another feature of the present invention is a drainage mechanism for draining the turbine's water outlet. Water flows through a system of pipes and automatic flow control valves in the following sequence: Drainage from the turbine passes through the draft tube, then flows to a common manifold, a matrix of paired water storage tanks, and is then pneumatically pushed to the outside water body via a high-pressure air volume through an outlet at the lower end of the waterproof housing. During the drainage process, the opening and closing of the flow valves on these pipes is automatically controlled, and synchronized flow is crucial to maintain the same flow rate of water entering and leaving the turbine.

[0009] The turbine outlet, sometimes called the draft tube, features an increased cross-sectional area to minimize destructive water cavitation. In this new arrangement, a further vessel, the flow conditioner vessel, is included as part of the common header. Within the common header, multiple flow guide vanes minimize turbulence and distribute the water evenly over a wider area, efficiently filling the storage tanks below through a porous outlet. These tanks can be cylindrical or rectangular in cross-section and constructed from steel, reinforced concrete, or other materials such as plastic, fiberglass, or a combination for improved structural performance. The tanks can be arranged in rows and columns, in either a vertical or horizontal configuration, for optimal design and site-specific layout. The total water capacity of these tanks should ideally be greater than the total water required to operate the turbines within a specified timeframe, which impacts the overall filling and emptying cycle of the tanks. Each tank is connected to the common header outlet at a relatively low point via a controlled flow valve. A control valve and a check valve are located at the other end of the tank outlet, which then connects to the outlet opening at the lower end of the casing. A settling chamber is included at this end to allow the discharged water to settle before completely flowing out, thus preventing any corrosion to the underwater environment. Each water storage tank is filled one at a time from a common water collector until it is full. Each water tank is equipped with an open vent valve to eliminate air lock during filling and closes once it is full. When the valve from the water collector is closed, the air supply valve will open and pressurize the water tank to a predetermined pressure level. The outlet valve of the water tank is then opened and the air pressure pushes the water out to the external water body until it is nearly empty or reaches a predetermined water level. The outlet valve is then closed, the air inlet valve is also closed, and the vent is opened. The empty water storage tank is then ready for the next filling cycle. The compressed air volume can be introduced into the water storage tank with or without a rubber bladder, and the air pressure is sufficient to overcome friction and external hydrostatic pressure.

[0010] Another feature of the present invention is a shaped channel with a partially meshed wall. This channel connects to the water outlet of the housing (at the bottom of the housing), extends upward along the outer wall of the housing, and then connects to the water inlet screen opening at the top of the housing. This helps maintain water quality at the water inlet and minimizes disturbance to the surrounding environment. A mesh section is provided along the length to enable bidirectional water flow, and an atmospheric vent is provided at the top to maintain atmospheric pressure.

[0011] Another feature of the present invention is the provision of a closed hollow channel that is connected to the outlet of the turbine drainage system (at the bottom of the housing), extends upward, and is then connected to the water inlet opening at the top of the turbine water inlet via a pressure pipe. An atmospheric vent is provided in the upper portion of the housing channel. This arrangement will allow water from the relatively low-level turbine outlet to circulate to the relatively high-position turbine water inlet. The housing channel is designed to receive, temporarily store, and supply sufficient water to meet the flow rate required by the turbine, regardless of its location and the relative height of the entire hydropower unit relative to the natural ground. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] To help understand the present invention, some features and applications of the present invention will be described with reference to the accompanying drawings. In the drawings:

[0013] Figure 1 is a flow chart of an embodiment of a hydroelectric power plant of the present invention;

[0014] Figure 2 is another flow chart of an embodiment of a hydroelectric power plant of the present invention;

[0015] Figure 3 is a longitudinal side sectional view of an embodiment of the present invention;

[0016] Figure 4 yes Figure 3 AA cross-sectional view of an embodiment of the present invention;

[0017] Figure 5 is a longitudinal side sectional view of an embodiment of the present invention;

[0018] Figure 6 is a longitudinal side sectional view of an embodiment of the present invention;

[0019] Figure 7 is an isometric view of an embodiment of the present invention;

[0020] Figure 8 is a longitudinal side sectional view of an embodiment of the present invention;

[0021] Figure 9 is another longitudinal side sectional view of an embodiment of the present invention;

[0022] Figure 10 is another longitudinal side sectional view of an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The illustrated drawings are a basic outline of the overall descriptive information of the present invention on the sequence of water flows on the mechanical components of a hydroelectric power plant.

[0024] Figure 1The flow chart of an embodiment of a hydroelectric power plant according to the present invention is shown below. Water 1 flows into the penstock 5. This water is a combination of water flow 30 from an external body of water 32 through openings 25 and partial return flow 18 from a bottom outlet 17. Water inlets 25, located at at least two locations, include screens to prevent any unwanted debris. Openings 29 also function to maintain the relative static pressure of water flow 18 under various load conditions. Water 1 enters turbine 9 through inlet 22, driving it to rotate and generate mechanical output power for the generator. Water 1 then exits through turbine outlet 6 and enters flow regulator vessel 10. The primary function of vessel 10 is to redirect and regulate water flow 1 into a uniform output flow, which flows through multiple orifices 39 into water collector 11. Vessel 10 and water collector 11 are designed to operate together, or within a single vessel, to minimize the time required for the water filling process. The cross-sectional area of ​​the internal guide vanes of vessel 10 is used to minimize fluctuations in water flow during the filling process when the water tanks are located far apart. (In some cases, the tanks may be spaced 200 meters apart.) Water 1 then flows from collector 11 to storage tank 12 via connecting pipes and valve 7. Valves 7 and 13 automatically control the opening and closing of the water flow according to a predetermined flow sequence. The number and size of storage tanks 12 are predetermined by factors such as the total water flow capacity of turbine 9, the designed operating hours per day, and other factors such as the time lag between opening and closing of large-sized valves to handle the designed flow.

[0025] A high-pressure air tank 16 is connected to the upper end of the water storage tank 12 via an automatic valve 15. The air pressure is preferably set above the relative hydrostatic pressure at the outlet 17 so that, when water is discharged from the tank 12, the operating pressure still prevents backflow into the external body of water 32. The emptying of these tanks 12 must be synchronized with the draining of the turbines to avoid backpressure that could affect the power output of the turbine 9. The filling and emptying sequence for the tanks 12 is as follows: Valve 13 is closed, valve 7 is opened, and water is allowed to fill the tanks 12. Then, valve 7 is closed, and valve 15 is opened, allowing air from the tank 16 to pressurize the water in the tank 12 until it reaches the set pressure. Then, outlet valve 13 is opened, allowing water to drain through check valve 14 and outlet 17 into the external settling chamber 34 and the external body of water 32. When the water level reaches a predetermined minimum level, valve 13 and valve 15 are closed. The air in the tanks is then discharged through valve 8, ready for the next filling sequence. The emptying and filling cycles of each water tank 12 overlap to prevent any pressure fluctuations that could affect turbine flow performance. Valves 7 and 13 are fully automatic, while valve 14 is a one-way flow pressure valve set to prevent any water ingress. A drainage settling chamber 34 is also provided to minimize water flow disturbance and promote environmental protection. All valve apertures are kept relatively small, yet large enough to meet the maximum design flow rate, minimizing time delays during opening and closing. The watertight housing 4 is a waterproof protective enclosure that prevents infiltration of lake or seawater and withstands dynamic and static water pressures during its design life. It also provides structural support for the hydropower plant machinery and provides a dry internal working space 21. The housing 4 can be cast in situ of reinforced concrete or prefabricated in modular sections from reinforced concrete, steel, or other relatively durable materials. The drainage flow 18 can flow upward toward the water inlet 2 through the enclosed channel 24 primarily by natural and thermal convection, combining with a supplementary flow 30 from an external body of water 32 through a plurality of pre-defined open grid windows 25 in the lower portion of the housing 4. The openings in this enclosed channel 24 are designed to prevent any unnecessary negative pressure while maintaining a relative static pressure during water circulation. The design of the open grid windows 25 allows water to enter the channel 24 while preventing the entry of unwanted debris. An opening 29 to the atmosphere is provided in the channel 24 to release any accumulated pressure. Vent 3 is a general atmospheric vent, and opening 27 is provided for mechanical maintenance. Platform 28 is used for loading and unloading services and can also serve as a helicopter landing space if necessary. Water level or sea level 19 indicates a relative water mark for reference. Length 21 is the relative and estimated height difference between the water inlet and the turbine outlet, and height 31 is the estimated height difference from the turbine outlet to the base for reference. Atmosphere 20 and external water 32 are provided for reference. The internal open space 33 within the housing 4 is open to the external atmosphere 20. The base 26 of the waterproof housing 4 can be anchored to the lake or seabed if buoyant, otherwise a solid foundation is required to support the significant gravity and dynamic loads.

[0026] Figure 2 This invention Figure 1 The water storage tank 12 can be placed horizontally or at a certain angle relative to the vertical inlet flow on the pressure pipe 5. This arrangement may be preferred because the installation depth can be shallower and the available water depth can be fully utilized to increase the hydraulic height difference between the water inlet 2 and the turbine 9, thereby increasing the power output. Figure 1 All items in remain unchanged.

[0027] Figure 3 yes Figure 1 is a partial cross-sectional flow chart showing graphic shape variations of an embodiment of the present invention. The container 10 and common water collector 11 are shown as a whole, with their outlets connected to valve 7 and then to water storage tank 12. Depending on the power level of the power station, it may be more economical for these tanks to be cast in situ of reinforced concrete. The ends of the tanks 12 are to be equipped with a removable prefabricated reinforced concrete end cover assembly, as well as mountings for stainless steel or cast iron pipe fittings and valves. All fittings must be corrosion resistant. The maintenance spaces 35 and surfaces 40, 41, 42 and 43 of the various parts of the power station must be structurally strong and accessible to allow heavy lifting equipment to enter during installation and heavy equipment maintenance. Valve 13 and non-return valve 14 are shown connected to the tank 12 and then to the water flow settling tank 34 before the water flows out through outlet 17. The water flow settling tank 34 is located inside the shell 4, which has maintenance advantages because it has a dry atmospheric area.

[0028] Figure 4 yes Figure 3 The AA cross-sectional view of an embodiment of the present invention illustrates the basic matrix arrangement of water storage tanks 12 within a reinforced concrete casting 33. The internal contour of the water tanks 12 is shown as circular, but any other contour, such as a square or other polygonal shape, is possible. A space 35 between the walls of the waterproof housing 4 and the water tank casting 33 provides clearance for heavy lifting machinery.

[0029] Figure 5 yes Figure 3 This diagram illustrates a partial cross-section of an embodiment of the present invention, in which water storage tanks 12 are interconnected via connectors 37 and 38. A vent valve 8 is required at at least one location on the top of the tank 12. The number of fill valves 7 and drain valves 13 can be reduced. These tank interconnects 37 and 38 will alter the fill and drain cycle times depending on the total amount of water available for circulation. This arrangement may be suitable for other applications and economic reasons.

[0030] Figure 6 This is a partial flow chart of an embodiment of the present invention. The water storage tank is configured as an endless loop. Its longitudinal length is aligned horizontally. Valves 7 and 13 are located at both ends. A vent valve 8 is located at the top horizontal length of the water tank 12. This tank arrangement may have the advantage of requiring fewer valves.

[0031] Figure 7 This is a basic isometric view of an embodiment of the present invention. The waterproof housing 4 is shown as a rectangular outline, with section break lines 33 provided for clarity. This outline shape may serve as the standard overall physical structure for the present invention due to its simplicity and ability to leverage natural gravity. For example, in current pumped-storage hydroelectric power plants, the external energy required to pump water back to the upper reservoir is currently provided by external energy sources such as solar and wind farms. In the present invention, however, the return of water within the circulation is accomplished naturally through water flow, based on fluid dynamics, and aided by pneumatic air pressure energy.

[0032] In this view, the penstock 5 extends downward and connects to the turbine 9 inside the waterproof housing 4. The flow regulator container 10 and the common water collector 11 are combined in a single housing. The cavity of the water storage tank 12 is integrated into the reinforced concrete housing 33. Then, valves 13 and 14 are shown below, connected to the settling tank 34. Labels for other missing items have been intentionally omitted for clarity.

[0033] The simple rectangular structural shape shown was determined using a practical approach, and a medium-sized hydropower plant was chosen as the basis for calculating the physical shape. The shape selection took into account the global availability of mechanical components for hydropower plants, economics, maintainability, and environmental requirements. In this case, a 50 MW underwater hydropower plant was selected according to the present invention. The mechanical power formula (power = mass flow × gravity constant × height difference × efficiency) was theoretically calculated, where mass flow and height difference are the two main variables determining the power rating of the plant, since gravity and mechanical efficiency are fixed values.

[0034] Therefore, for manufacturing and standardization purposes, the maximum power output level according to the scope of the present invention can be calculated by selecting a variable or combination, thereby achieving scalability of the mechanical and structural envelope. For example, if we have three potential abandoned open-pit mine sites with natural surface areas with cave openings of 300 meters by 300 meters and potential cave depths of 450 meters, 550 meters, and 700 meters, respectively, then according to this theoretical practical approach, we can obtain 526MW of clean energy for 24 hours a day, 7 days a week. Therefore, there is an opportunity to standardize our three proposed units. By using readily available standardized components, including turbines, valves, bearings, couplings, and standard air compression systems with appropriate mechanical ratings, capital costs and operating and maintenance costs should be relatively low, and the use of digital technology in the operation of the water flow control valves (particularly the filling and emptying of the water storage tank 12) will potentially reduce premature failures.

[0035] Figure 8 is a longitudinal side sectional view of an embodiment of the present invention, similar to Figure 3A cross-sectional view of the device is shown, excluding the following components: housing 4, work platform 28, vents 27, and 3. The grid of openings 25 no longer exists on the enclosed channel 24, except at the outlet opening 17 at the base of the device, the turbine inlet, and the vent opening 29 at the top. Water can be filled to a predetermined level 47 above the turbine inlet. This arrangement could be suitable for land above sea level, eliminating the need to dig a deeper hole for the reservoir. Figure 3 The other items in remain unchanged.

[0036] Figure 9 is a longitudinal side sectional view of an embodiment of the present invention, similar to Figure 3 A cross-sectional view of the device is shown, excluding the following components: housing 4, work platform 28, vents 27, and 3. The grid of openings 25 no longer exists on the enclosed passage 24, except at the outlet opening 17 at the base of the device, the turbine inlet, and the vent opening 29 at the top. Water can be filled to a predetermined level 47 above the turbine inlet. This arrangement may be suitable for land above sea level, where part of the device can be located below ground level. Figure 3 The other items in remain unchanged. Figure 8 and Figure 9 The arrangements can be located in industrial areas or next to skyscrapers in urban areas as part of the structure and its water and power supply, generating electricity and saving capital and running costs.

[0037] This is a starting point for collecting useful information on the novel hydroelectric power plant described herein, potentially creating further opportunities for standardization of structural features and equipment within the power generation industry, in accordance with the scope of the present invention.

[0038] This will increase the suitability of clean energy hydropower sites, including in marine areas close to urban populations and lakes with permanent water bodies, thereby promoting and accelerating the decarbonization of thermal power plants globally.

[0039] Figure 10 is a longitudinal side cross-sectional view of an embodiment of the present invention; illustrating the Bernoulli equation with arbitrary values. Calculations are made with reference to the nominal 20 MW power output of the present invention (hydropower system). Item 4 is the vertical housing wall that holds the vertical body of water 46. Item 47 is the top water level, and item 48 is the vertical water level from above the penstock inlet to the top water level 47, which is open to the atmosphere 33 through 29. Dimension 21 is the effective height difference between the water inlet and the turbine outlet. Item 49 is the height difference between item 47 and the outlet 17. Item 2 is the water inlet to the penstock 5, which supplies the turbine 9. The water collector and water tank downstream of the turbine outlet are combined into item 51 to simplify calculations. The water body 12 is contained in a container 51, with air pressure 52 and air volume 50 above the water surface. The air supply 51 is controlled by switching the air flow valve 15.

[0040] The following are arbitrary data and hypothetical values ​​of metric measurements and their symbols related to Bernoulli's equation.

[0041] Item 48 = Vertical height of water above the penstock inlet

[0042] Item 49 = H1 = 200 m (height from the bottom of the vertical water body outlet to the water level)

[0043] Item 21 = H2 = Effective height difference from water inlet to turbine inlet

[0044] Item 45 = Datum 1 = Internal tank top water level

[0045] Item 52 = P1 = Air pressure applied at reference level 1

[0046] P2 = static pressure at bottom drain

[0047] V1 = Water velocity at hypothetical datum level 1 = 0.5 m / s

[0048] V2 = Water velocity at assumed reference level 2 = 2 m / s

[0049] = water density

[0050] ∑ = sum

[0051] According to Bernoulli's equation

[0052]

[0053] →P2=1.96 MPa

[0054] The required volume and pressure for the air compressor must be greater than 1.96 MPa, with a power input of 6.8 MW. Therefore, the mechanical efficiency is 65.5%. Water is incompressible due to its fluid properties, and according to the laws of water convection, the water supply to the top inlet and penstock is accomplished by water molecules in the top portion of the vertical water body 46. The restriction provided by the wall 4 forces the water molecules to move upward in a controlled and predictable manner. The water body, with sufficient height 48 and potential energy, is designed to maintain the desired flow rate of water molecules into the penstock inlet 2, unless low temperatures or other water conditions affect the water flow, in which case external energy may be required to regulate the water quality and condition.

Claims

1. A hydroelectric power plant comprising: (a) a vertical body of water having a total height equal to that required to cover the specified electrical output, plus additional power to overcome the head losses of water flow in associated vessels and piping, having at least a structural watertight wall separating said vertical body of water from an adjacent hydroelectric unit, said hydroelectric unit being mounted in close proximity in a descending functional arrangement and preferably located within an atmospherically dry space; (b) a water collector as a temporary gravity energy storage device, similar to a kinetic energy storage flywheel; receiving water discharged from the turbine and distributing the water downstream to at least two water tanks; the at least two water tanks are connected in parallel and equipped with water flow control valves; and (c) A high volume and high pressure air supply is introduced into the two water tanks, one at a time, to discharge the water by sequentially synchronizing and staggering the opening and closing of the water flow valves to ensure a continuous downward flow of water from the turbine to the outlet.

2. The hydroelectric power plant according to claim 1, wherein the vertical body of water may be in a fully enclosed or partially open enclosure, or open to a lake or ocean.

3. The hydroelectric power plant according to claims 1 and 2, wherein the movement of water molecules from the bottom outlet to the top of the water body is mainly achieved by natural convection or forced convection.

4. The hydroelectric power plant according to claim 3, wherein the height of the upper portion of the vertical water body above the water inlet of the penstock has sufficient gravitational potential energy to keep the water flowing continuously to supply the turbine.

5. The hydroelectric power plant according to claims 1, 2, 3 and 4 has an expandable structural shell, is equipped with a hydroelectric generator set, can be designed and installed on ships and similar devices, can provide power for propulsion and movement, and provide power to users as needed.

6. The hydroelectric power plant according to claims 1, 2, 3, 4 and 5, which can be further scaled down to a practical version mounted on public vehicles to provide power for their mobility and carrying capacity, such as for mining applications and / or public transportation.

7. The hydroelectric power plant according to claims 5 and 6 needs to place the vertical water body in a completely closed container to prevent water leakage, and an atmospheric vent valve is provided at the top to prevent water leakage.

8. The hydroelectric power plant according to claims 1, 2, 3, 4, 5, 6 and 7, wherein the physical size and shape of the vessel including the internal guide vanes, water inlet, water outlet and water screen are designed and constructed to minimize water flow turbulence and maintain water quality, thereby maximizing its performance efficiency and adaptability to each application.

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