A method for improving the efficiency of pumped storage by buoyancy energy storage

Abstract

The application discloses a method for improving the efficiency of pumped storage by buoyancy energy storage, comprising a pumped storage system, a buoyancy energy storage unit, a monitoring and control unit, and a power transmission and transformer station unit, wherein the buoyancy energy storage unit comprises a floating body, a motor, an energy transmission and fixing assembly, the floating body has two motion states of diving and floating, and has two storage states of floating and bottom fixing; the floating body is fixed, floats or dives along with the water level of the water storage unit, and the potential energy of the floating body is converted into electric energy by the buoyancy energy storage unit; the power transmission and transformer station unit is connected with the motor, the power transmission and transformer station unit transmits the excess energy of a power grid and a wind-solar photovoltaic power grid to the pumped storage system, or makes the buoyancy energy storage unit convert electric energy into potential energy of buoyancy and store the potential energy of buoyancy, or transmits the electric energy generated by the buoyancy energy storage unit to the power grid. The application can improve the energy storage efficiency of the pumped storage system for various types of pumped storage modes.

Description

Technical Field

[0001] This invention belongs to the field of energy storage technology, specifically relating to a method for improving pumped hydro storage efficiency through buoyancy energy storage. Background Technology

[0002] Pumped storage is currently the most technologically mature, economically optimal, and best suited for large-scale development of a green, low-carbon, clean, and flexible power source for power systems, and it is an urgent requirement for building a new power system based on new energy sources. At present, my country has built a large number of pumped storage systems with world-class advanced capabilities, with a significant increase in installed capacity and a marked improvement in technological level.

[0003] Currently, the efficiency of pumped storage systems is generally between 65% and 75%. As a large-scale energy storage system, as of 2020, the global installed capacity of pumped storage was 159 million kilowatts, accounting for 94% of the total energy storage capacity. Improving the energy storage efficiency of pumped storage has significant implications for energy conservation and emission reduction, as well as tangible benefits.

[0004] In the actual application of pumped storage systems, due to factors such as the setting of water inlet and outlet pipes and terrain, some pumped storage systems have a certain dead storage capacity that cannot be effectively utilized. If the dead storage capacity can also be used in pumped storage systems, it will effectively improve the energy storage capacity of pumped storage systems.

[0005] Existing solutions for improving pumped storage efficiency mainly focus on reducing pumping by modifying the pumped storage units, allowing variable-speed pumped storage units to operate in high-efficiency operating ranges to improve the energy storage efficiency of the power station (CN112904721A). This invention starts from the basic working characteristics of pumped storage systems and utilizes the principle of water level changes and buoyancy energy storage during pumping and releasing to improve the energy storage efficiency of pumped storage systems through additional power generation. Summary of the Invention

[0006] Based on this, in order to address the problem of low pumped storage energy efficiency, the present invention provides a method for improving pumped storage efficiency through buoyancy energy storage.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A method for improving pumped storage efficiency through buoyancy energy storage includes a pumped storage system, a buoyancy energy storage unit, a monitoring and control unit, and a power transmission and transformer station unit.

[0009] The pumped storage system includes a number of water storage units, which are divided into higher-level water storage units and lower-level water storage units according to the terrain elevation; the buoyancy storage unit includes a number of floats;

[0010] A buoyancy storage unit is set in each water storage unit. The volume and number of floats in the water storage unit are set to meet the following two conditions: 1) The water storage unit can significantly squeeze the water below the dead reservoir water level line into the water above the dead reservoir water level line after reaching the dead reservoir water level line; 2) Water from one water storage unit is squeezed into another water storage unit. At this time, the water level of the water storage unit being squeezed into cannot exceed the full water level line of the water storage unit being squeezed into.

[0011] Each water storage unit is configured with a full water level line, a dead water level line, and a minimum working position line for the floats from top to bottom. When the floats in the higher water storage units are below the dead water level line and in a fixed state, the floats in the lower water storage units are not above the full water level line and are in a floating state. When all the floats in the higher water storage units are in a floating state and the water level is not above the full water level line, the water level in the lower water storage units is at the dead water level line, and all the floats in the lower water storage units are at the minimum working position line for the floats and remain fixed.

[0012] The pumped storage system pumps water from a lower-level storage unit to a higher-level storage unit during the energy storage process to convert electrical energy into water gravitational potential energy and store it. This is manifested as an increase in water depth in the higher-level storage unit and a decrease in water depth in the lower-level storage unit.

[0013] During the energy release process, water from the higher-level water storage unit flows down to the lower-level water storage unit to realize the conversion of water gravitational potential energy into electrical energy and the release of energy. This is manifested as a decrease in water depth in the higher-level water storage unit and an increase in water depth in the lower-level water storage unit.

[0014] The buoyancy energy storage unit works in tandem with the pumped storage system during the pumped storage process. The floating body generates additional electrical energy when it rises to the surface; during the submersion process, the floating body converts the electrical energy into the floating body's potential energy, thus achieving additional energy storage; and during the submersion process after the floating body reaches the dead reservoir water level, it pushes the water below the dead reservoir water level to above the dead reservoir water level, enabling the pumped storage system to continue pumped storage.

[0015] Furthermore, the buoyancy energy storage unit can be centrally or distributed in the water storage unit; the buoyancy energy storage unit also includes an energy transfer and fixing component and a motor, the energy transfer and fixing component is responsible for limiting and fixing the float and the motor and transmitting energy; the float has two motion states, submerging and surfacing, and two storage states, floating and bottom fixed.

[0016] Furthermore, when the float is in a floating state, it can be lowered and remain floating as the water level of the water storage unit decreases; the distance of the direction of gravity of the float relative to the bottom of the water storage unit can be controlled by energy transfer and adjustment of the fixing components.

[0017] Once the float is fixed, it is in a fixed state. When the water level of the water storage unit where the float is located rises above the float by a certain distance, and the buoyancy generated at this distance can cause the float of the corresponding buoyancy energy storage unit to float and generate electricity, the float will be released to float. During the floating process, the corresponding buoyancy energy storage unit converts the buoyancy potential energy of the float into electrical energy.

[0018] As the water level in the storage unit where the float is located rises above the float and continues to rise, the buoyancy potential energy of the float increases continuously, allowing the float to remain floating.

[0019] The process of a floating body maintaining its floating state descending and becoming fixed as the water level in the water storage unit decreases does not consume energy or consumes less energy than the energy generated when the floating body is released from its fixed position and floats back to the same water level.

[0020] Furthermore, the power transmission and transformer station unit and the buoyancy energy storage unit are connected by motors. The power transmission and transformer station unit transmits excess energy from the power grid and wind and solar power grids to the pumped storage system. The electrical energy generated by the buoyancy energy storage unit is supplied to the pumped storage system for pumping operations via the power transmission and transformer station unit. Alternatively, the electrical energy generated by the buoyancy energy storage unit is used by the power transmission and transformer station unit to submerge the floating body in the buoyancy energy storage unit, converting the electrical energy into buoyancy potential energy for storage. The electrical energy generated by the buoyancy energy storage unit is also directly transmitted to the power grid via the power transmission and transformer station unit.

[0021] Furthermore, the buoyancy energy storage unit adopts different buoyancy energy storage methods depending on the geographical and climatic location of the water storage unit; the motor of the buoyancy energy storage unit can be set outside the water storage unit, at the bottom of the water storage unit, or as a whole with the float; the float is a low-flow-resistance rigid pressure-resistant float or a low-flow-resistance elastic float with compressed volume.

[0022] In this invention, the terms "higher water storage unit" and "lower water storage unit" refer to the relative height of the water storage units. For a broad interpretation, each of the higher and lower water storage units may contain at least one water storage unit. When the lower water storage unit includes multiple water storage units, the arrangement of its floats shall meet the following requirements: 1) After reaching the dead reservoir water level, all floats of the lower water storage unit shall significantly push the water below the dead reservoir water level above the dead reservoir water level; 2) The water in the lower water storage unit is pushed into the higher water storage unit, and at this time, the water level of the higher water storage unit being pushed into shall not exceed the full water level of the higher water storage unit being pushed into.

[0023] The method described in this invention is applicable to all scenarios that operate based on the pumped storage principle, including water tanks, mine shafts, and pumped storage situations involving multiple mine shafts.

[0024] Furthermore, the monitoring and control unit is used to simultaneously monitor the status of the pumped storage system and the buoyancy storage unit, realizing both pumping and buoyancy monitoring, so that the buoyancy storage unit follows the pumped storage process to improve the pumped storage efficiency.

[0025] The principle of this invention is as follows: During the operation of the pumped storage system, as the water level in some storage units decreases and the water level in others increases, the distance between the floating body inside the corresponding storage unit and the bottom of the unit decreases until it is fixed at a certain distance. When the water level in the storage unit rises again to a height above a certain level, the floating body inside the corresponding storage unit is released. The buoyancy energy storage unit converts the buoyancy potential energy of the floating body into electrical energy. The generated energy can be transmitted to the power grid through the transmission and transformer station unit, or through... The power transmission and transformer station unit causes the buoy to submerge for energy storage. When energy needs to be released, it combines with the buoyancy energy storage unit to convert buoyancy potential energy into electrical energy for release. The buoy, which remains floating, does not consume energy or consumes less energy than the energy generated when it is released and rises to the same water level as the water level. When the water depth of the corresponding water storage unit returns to the original water depth, the total buoyancy potential energy of the buoy returning to the water surface is converted into electrical energy through the buoyancy energy storage unit. By generating additional electrical energy, the overall energy storage efficiency of the pumped storage system is improved.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] In this invention, the floating body in a floating state can consume a small amount of energy, or even no energy, as it descends with the decrease in water level. By incorporating buoyancy energy storage technology, the energy storage efficiency of existing pumped storage methods can be improved, which has significant implications for energy conservation and emission reduction and provides practical benefits.

[0028] This invention can improve the energy storage efficiency of pumped storage systems for various types of pumped storage methods, including traditional surface-built pumped storage systems, as well as pumped storage systems built in underground caverns and abandoned mines. It can cover pumped storage situations in pools, mine tunnels, and multiple mine tunnels. Attached Figure Description

[0029] Figure 1 This is a cross-sectional structural diagram of Embodiment 1 of the present invention.

[0030] Figure 2 This is a top view of the structure of Embodiment 1 of the present invention.

[0031] Figure 3 This is a cross-sectional structural diagram of Embodiment 2 of the present invention.

[0032] Figure 4 This is a basic logic diagram of the energy storage and release process of the present invention.

[0033] Figure 5 A diagram showing the flow of electrical energy supplied to the power grid.

[0034] Figure 6 A diagram showing the flow of electricity generated by pumped-storage systems and buoyancy storage units.

[0035] Explanation of reference numerals in the attached diagram: 1. Pumped storage system; 2. Buoyancy storage unit; 3. Monitoring and control unit; 4. Transmission and transformer station unit; 5. Full water level line; 6. Dead reservoir water level line; 7. Lowest operating position line of the buoy.

[0036] 11. Higher-level water storage unit; 12. Lower-level water storage unit; 13. Energy conversion component;

[0037] 21. Float; 22. Motor; 23. High-strength cable; 24. Deep-water fixed pulley; 25. Upper fixed pulley; 26. Power transmission line. Detailed Implementation

[0038] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0039] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or a connection through an intermediate medium; and they can refer to an internal connection between two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] like Figure 1 , Figure 2As shown, a method for improving pumped storage efficiency through buoyancy energy storage includes a pumped storage system 1, a buoyancy energy storage unit 2, a monitoring and control unit 3, and a power transmission and transformer station unit 4.

[0042] like Figure 1 As shown, the pumped storage system 1 includes several higher-level water storage units 11, several lower-level water storage units 12, and an energy conversion component 13; the buoyancy storage unit 2 includes several floats 21, a motor 22, and an energy transmission and fixing component.

[0043] like Figure 1 , Figure 2 As shown, the pumped storage system 1 pumps water from the lower water storage unit 12 to the higher water storage unit through the energy conversion component 13 during the energy storage process, thereby realizing the conversion of electrical energy into water gravitational potential energy and energy storage. This is manifested as an increase in water depth in the higher water storage unit 11 and a decrease in water depth in the lower water storage unit 12.

[0044] like Figure 1 , Figure 2 As shown, the pumped storage system 1, during the energy release process, causes water from the higher-level storage unit to flow down and generate electricity through the energy conversion component 13, which then transmits the electricity to the lower-level storage unit 12, thus realizing the conversion and release of water's gravitational potential energy into electrical energy. This is manifested as a decrease in water depth in the higher-level storage unit 11 and an increase in water depth in the lower-level storage unit 12; as... Figure 1 , Figure 2 As shown, the buoyancy energy storage unit 2 can be arranged in a centralized manner or in a distributed manner in the water storage unit.

[0045] like Figure 1 , Figure 2 As shown, the energy transfer and fixing component is responsible for limiting and fixing the float 21 and the motor 22, as well as transmitting energy.

[0046] like Figure 1 , Figure 2 As shown, the float 21 has two motion states: submerging and surfacing, and two storage states: floating and fixed. When the float 21 is in the floating state, it can be lowered as the water level of the water storage unit decreases and maintain the floating state. The distance of the direction of gravity of the float 21 in the floating state relative to the bottom of the water storage unit can be controlled by energy transfer and adjustment of the fixing component 23.

[0047] The floating body 21 in the floating state can be driven by an electric motor 22, an energy transmission and fixing component to make the floating body 21 submerge to a certain distance from the bottom of the water storage unit in the direction of gravity of the floating body 21 and then fix it.

[0048] The minimum distance between the gravity direction of the float 21 and the bottom of the water storage unit should not affect the normal operation of the buoyancy energy storage unit 2. The floating float 21 is pulled down below the dead reservoir water level 6 by electrical energy, and the electrical energy is converted into buoyancy potential energy to utilize the water below the dead reservoir water level 6.

[0049] Once the float 21 is fixed, it is in a fixed state. When the water level of the water storage unit where the float 21 is located rises above the float 21 by a certain distance, and the buoyancy generated at this distance can cause the float 21 of the corresponding buoyancy energy storage unit to float and generate electricity, the float 21 will be released to float. During the floating process, the corresponding buoyancy energy storage unit 2 converts the buoyancy potential energy of the float 21 into electrical energy.

[0050] As the water level in the storage unit where the float 21 is located rises above the float 21, the buoyancy potential energy of the float 21 increases continuously, causing the float 21 to remain floating.

[0051] The process of the floating body 21, which remains floating, descending until it is fixed as the water level of the water storage unit decreases, does not consume energy or consumes less energy than the energy generated when the floating body 21 is released from its fixed position and floats back to the same water level.

[0052] The energy transfer and fixing components are responsible for transmitting electrical energy, fixing the float 21, and maintaining the movement trajectory of the float 21.

[0053] The buoyancy energy storage unit 2 can adopt different buoyancy energy storage methods depending on the geographical and climatic location of the water storage unit, such as... Figure 1 , Figure 2 As this is an open-air situation, motor 22 is placed on the shore. Figure 3 Inside the mine, the motor 22 is placed at the bottom. Alternatively, multiple macroscopic water storage units can be formed by the sea and surrounding mountains, utilizing elevation differences for pumped-storage energy storage. In this case, a truss can be erected, and a fixing device can be added to the buoyancy storage unit 2 to prevent the buoy 21 from moving arbitrarily in the vertical direction. The selection of the buoyancy storage unit 2 is based on a comprehensive consideration of the scale of the water storage units in the pumped-storage system, geographical location, meteorological conditions, and cost.

[0054] The motor 22 can be located outside the water storage unit, at the bottom of the water storage unit, or integrated with the float 21. The motor 22 can be a winch motor, an electric motor + winch, a permanent magnet motor, etc. The energy transmission and fixing components include a high-strength cable 23, a deep-water fixed pulley 24, a power transmission line 26, or an upper fixed pulley 25. The high-strength cable 23 connects to the float 21 and is connected to the motor 22 outside the water storage unit via the upper fixed pulley 25. The float 21 can also be fixed physically, such as magnetically or mechanically.

[0055] like Figure 5 , Figure 6 As shown, the power transmission and transformer station unit 4 and the monitoring and control unit 3 are electrically connected through the power transmission line 26. The power transmission and transformer station unit 4 and the buoyancy energy storage unit 2 are electrically connected through the power transmission line 26. The motor 22 inside the buoyancy energy storage unit 2 is connected to the float 21 through the high-strength cable 23, so that the power transmission and transformer station unit 4 can provide power to the buoyancy energy storage unit 2, and at the same time store the power released by the float 21.

[0056] Figure 6 The transmission and transformer station unit and the buoyancy storage unit are connected by motors. The transmission and transformer station unit transmits excess energy from the power grid and wind / solar power grid to the pumped storage system. Power conversion between the pumped storage units is achieved through the transmission and transformer station unit. The electricity generated by the buoyancy storage unit powers the pumped storage system for pumping operations via the transmission and transformer station unit. Alternatively, the electricity generated by the buoyancy storage unit causes the floating bodies in the buoyancy storage unit to submerge via the transmission and transformer station unit, converting electrical energy into buoyancy potential energy for storage. The floating bodies can refer to the same or different pumped storage units. The floating bodies within the same buoyancy storage unit can be controlled synchronously or asynchronously; that is, some floating bodies within the same buoyancy storage unit can be floating while others are submerged. The electricity generated by the buoyancy storage unit can also be directly transmitted to the power grid via the transmission and transformer station unit. The energy conversion within the pumped storage system itself can be implemented using existing technologies.

[0057] Optionally, the float 21 is a low-flow-resistance rigid pressure-resistant float or a low-flow-resistance elastic float with compressed volume (in conjunction with compressed air).

[0058] Example 1:

[0059] The method in this embodiment can be implemented by combining the buoyancy energy storage unit 2 with the pumped hydro storage system 1 as shown in patent (CN115234430A), such as... Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 6 As shown;

[0060] like Figure 1 , Figure 2 As shown, the pumped storage system 1 pumps water from the lower water storage unit 12 to the higher water storage unit through the energy conversion component 13 during the energy storage process, thereby realizing the conversion of electrical energy into water gravitational potential energy and energy storage. This is manifested as an increase in water depth in the higher water storage unit 11 and a decrease in water depth in the lower water storage unit 12.

[0061] like Figure 1 , Figure 2As shown, during the energy release process, the pumped storage system 1 causes water from the higher storage unit to flow down from a higher position and generate electricity through the energy conversion component 13 to the lower storage unit 12, thereby realizing the conversion of water gravitational potential energy into electrical energy and the release of energy. This is manifested as a decrease in water depth in the higher storage unit 11 and an increase in water depth in the lower storage unit 12.

[0062] Assume that initially, the float 21 in the higher water storage unit 11 is located at the lowest working position line 7 of the float in the higher water storage unit 11 and is in a fixed state; the float 21 in the lower water storage unit 12 is located at the full water level line 5 and is in a floating state.

[0063] Assuming that when the water level in the higher water storage unit 11 is at the full water level line 5, the floats 21 in the higher water storage unit 11 are all in a floating state, and the water level in the lower water storage unit 12 is at the dead water level line 6 of the lower water storage unit 12, and the floats 21 in the lower water storage unit 12 are all at the lowest working position line 7 of the floats in the lower water storage unit 12 and remain fixed; this can improve energy storage efficiency and increase the energy stored and released in a single operation.

[0064] Assuming that when the water level in the lower water storage unit 12 is at the full water level line 5, the floats 21 in the lower water storage unit 12 are all in a floating state, and the water level in the higher water storage unit 11 is at the dead water level line 6 of the higher water storage unit 11, and the floats 21 in the higher water storage unit 11 are all at the lowest working position line 7 of the floats in the higher water storage unit 11 and remain fixed.

[0065] like Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 6 As shown, the energy storage phase will follow next;

[0066] During this stage, the pumped storage system 1 exhibits a rise in the water level of the higher-level water storage unit 11 and a decrease in the water level of the lower-level water storage unit 12.

[0067] During the energy storage phase, as the water level in the higher water storage unit 11 rises and the water level in the lower water storage unit 12 falls, the float 21 inside the higher water storage unit 11 remains fixed, while the float 21 inside the lower water storage unit 12 floats and falls with the water level. The process of the float 21 inside the lower water storage unit 12 falling with the water level of the lower water storage unit 12 until the dead water level line 6 of the lower water storage unit 12 does not consume energy or consumes less energy than the energy generated when the float 21 inside the lower water storage unit 12 is released from its fixed position at the dead water level line 6 and floats up to the full water level line 5 of the lower water storage unit 12.

[0068] When the water level in the lower water storage unit 12 drops to the dead water level line 6 of the lower water storage unit 12, the float 21 in the lower water storage unit 12 remains in a floating state throughout this process. Then, the float 21 in the lower-level water storage unit 12 is submerged under the rotation of the motor 22, while the water level in the higher-level water storage unit 11 continues to rise. Simultaneously, the monitoring and control unit 3 releases the float 21 in the higher-level water storage unit 11 from its fixed position and allows it to rise to the surface. During this process, the float 21 in the higher-level water storage unit 11 is pulled by the high-strength cable 23 to rotate the motor 22, generating electricity. The generated energy is transmitted through the transmission line 26 and the power transmission and transformer station unit 4 to the pumped storage system 1 for pumping and energy storage. Alternatively, through the transmission line 26 and the power transmission and transformer station unit 4, the float energy storage unit 2, which has other floats 21 in a floating state, is submerged, converting electrical energy into buoyancy potential energy for storage. This process both pushes some water below the dead reservoir water level 6 of the lower-level water storage unit 12 to above the dead reservoir water level 6, and the pumped storage system... The system continues pumping water for energy storage until the float 21 in the lower water storage unit 12 is completely submerged and the water level drops to the dead reservoir water level line 6 of the lower water storage unit 12. The float 21 in the lower water storage unit 12 continues to submerge to the lowest working position line 7 of the float in the lower water storage unit 12 and remains fixed. The beneficial effects of this process are threefold: 1. The float 21 in the higher water storage unit 11 rises to generate electricity, producing additional electrical energy; 2. The float 21 in the lower water storage unit 12 converts electrical energy into the potential energy of the float 21 during the submersion process, achieving additional energy storage; 3. During the submersion process of the float 21 in the lower water storage unit 12, the water below the dead reservoir water level line 6 of the lower water storage unit 12 is pushed to above the dead reservoir water level line 6 of the lower water storage unit 12, so that the pumped storage system 1 can continue to pump water for energy storage, thereby increasing the total energy storage capacity of the pumped storage system 1.

[0069] The energy storage phase has ended;

[0070] like Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 6 As shown, the next step is the energy release phase;

[0071] During this stage, the pumped storage system 1 exhibits a rise in the water level of the lower-level water storage unit 12 and a decrease in the water level of the higher-level water storage unit 11.

[0072] During the energy release phase, as the water level in the lower reservoir 12 rises and the water level in the higher reservoir 11 falls, the float 21 in the lower reservoir 12 remains fixed, while the float 21 in the higher reservoir 11 floats and falls with the water level. The process of the float 21 falling with the water level in the higher reservoir 11 until the dead reservoir water level 6 of the higher reservoir 11 does not consume energy or consumes less energy than the energy generated by the float 21 in the higher reservoir 11 when it is released from fixation and floats up to the full water level 5 of the higher reservoir 11.

[0073] When the water level in the higher-level water storage unit 11 drops to the dead reservoir water level line 6 of the higher-level water storage unit 11, its internal float 21 is in a floating state. The float 21 in the higher-level water storage unit 11 is pulled by the rotation of the motor 22 within the higher-level water storage unit 11, causing the float 21 in the lower-level water storage unit 12 to be released from its fixed position and rise to the water surface. During this process, the float 21 pulls the motor 22 to rotate and generate electricity via the high-strength cable 23. This process both pushes some water below the dead reservoir water level line 6 of the higher-level water storage unit 11 to above the dead reservoir water level line 6, and the pumped storage system 1 continues to release water to release energy until the float 21 in the higher-level water storage unit 11 is completely submerged and the water level drops to the lower level of the higher-level water storage unit 11. The dead reservoir water level 6 of the pumped storage system 1 is lowered, and the float 21 in the higher water storage unit 11 continues to descend to the lowest working position line 7 of the float in the higher water storage unit 11 and remains fixed. The beneficial effects of this process are threefold: 1. The float 21 in the lower water storage unit 12 rises to generate electricity, producing additional electrical energy; 2. The float 21 in the higher water storage unit 11 converts electrical energy into the potential energy of the float 21 during the descent, achieving additional energy storage; 3. During the descent of the float 21 in the higher water storage unit 11, the water below the dead reservoir water level 6 of the higher water storage unit 11 is pushed to above the dead reservoir water level line 6 of the higher water storage unit 11, so that the pumped storage system 1 can continue to release water and release energy, thereby increasing the total energy released during the energy release process of the pumped storage system 1.

[0074] The energy release phase has ended;

[0075] The method described in this invention improves the energy storage efficiency of the pumped storage system 1 by generating additional electricity, and also increases the energy stored and released in a single storage and release process of the pumped storage system.

[0076] Example 2;

[0077] This method can be used... Figure 3 , Figure 4 The buoyancy energy storage unit 2 shown is combined with the pumped hydro storage system 1 to achieve this, such as... Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown;

[0078] like Figure 3 , Figure 4 As shown, the pumped storage system 1 pumps water from the lower water storage unit 12 to the higher water storage unit 11 through the energy conversion component 13 during the energy storage process to realize the conversion of electrical energy into water gravitational potential energy and energy storage. This is manifested as an increase in water depth in the higher water storage unit 11 and a decrease in water depth in the lower water storage unit 12.

[0079] like Figure 3 , Figure 4 As shown, during the energy release process, the pumped storage system 1 causes the water in the higher-level water storage unit 11 to flow down from a high place and generate electricity through the energy conversion component 13 to the lower-level water storage unit 12, thereby realizing the conversion of water gravitational potential energy into electrical energy and the release of energy. This is manifested as a decrease in water depth in the higher-level water storage unit 11 and an increase in water depth in the lower-level water storage unit 12.

[0080] Compared to Embodiment 1, this embodiment is the same as Embodiment 1 except that the motor 22 of the higher water storage unit 11 is arranged at the bottom of the higher water storage unit 11, the motor 22 of the lower water storage unit 12 is arranged at the bottom of the lower water storage unit 12, and the motor 22 and the float 21 are connected by a high-strength cable 23 through a deep-water fixed pulley 24.

[0081] The application method of the buoyancy energy storage unit 2 described in this embodiment is the same as that described in Embodiment 1, and the beneficial effects are the same as those described in Embodiment 1.

[0082] The invention applies to the prior art where applicable.

Claims

1. A method for improving pumped hydro storage efficiency through buoyancy energy storage, characterized in that: It includes pumped storage systems, buoyancy storage units, monitoring and control units, and power transmission and transformer station units; The pumped storage system includes a number of water storage units, which are divided into higher-level water storage units and lower-level water storage units according to the terrain elevation; the buoyancy storage unit includes a number of floats; A buoyancy storage unit is set in each water storage unit. The volume and number of floats in the water storage unit are set to meet the following two conditions: 1) The water storage unit can significantly squeeze the water below the dead reservoir water level line into the water above the dead reservoir water level line after reaching the dead reservoir water level line; 2) Water from one water storage unit is squeezed into another water storage unit. At this time, the water level of the water storage unit being squeezed into cannot exceed the full water level line of the water storage unit being squeezed into. Each water storage unit is configured with a full water level line, a dead water level line, and a minimum working position line for the floats from top to bottom. When the floats in the higher water storage units are below the dead water level line and in a fixed state, the floats in the lower water storage units are not above the full water level line and are in a floating state. When all the floats in the higher water storage units are in a floating state and the water level is not above the full water level line, the water level in the lower water storage units is at the dead water level line, and all the floats in the lower water storage units are at the minimum working position line for the floats and remain fixed. The pumped storage system pumps water from a lower-level storage unit to a higher-level storage unit during the energy storage process to convert electrical energy into water gravitational potential energy and store energy. This is manifested as an increase in water depth in the higher-level storage unit and a decrease in water depth in the lower-level storage unit. During the energy release process, water from the higher-level water storage unit flows down to the lower-level water storage unit to realize the conversion of water gravitational potential energy into electrical energy and the release of energy. This is manifested as a decrease in water depth in the higher-level water storage unit and an increase in water depth in the lower-level water storage unit. The buoyancy energy storage unit works in conjunction with the pumped storage system during the pumped storage process. The floating body generates additional electrical energy when it rises to the surface; during the descent, the floating body converts the electrical energy into the buoyancy potential energy of the floating body to achieve additional energy storage; during the descent after the floating body reaches the dead reservoir water level, it pushes the water below the dead reservoir water level to above the dead reservoir water level, enabling the pumped storage system to continue pumped storage. When the float is in a floating state, it decreases and remains floating as the water level in the water storage unit decreases; the distance of the direction of gravity of the float relative to the bottom of the water storage unit is controlled by energy transfer and adjustment of the fixing components. Once the float is fixed, it is in a fixed state. When the water level of the water storage unit where the float is located rises above the float by a certain distance, and the buoyancy generated at this distance causes the float of the corresponding buoyancy energy storage unit to float up and generate electricity, the float will be released to float up. During the floating process, the corresponding buoyancy energy storage unit converts the buoyancy potential energy of the float into electrical energy. As the water level in the storage unit where the float is located rises above the float and continues to rise, the buoyancy potential energy of the float continues to increase. The process of a floating body maintaining its floating state descending until it is fixed as the water level in the water storage unit decreases does not consume energy or consumes less energy than the energy generated when the floating body is released from its fixed position and rises to the same water level.

2. The method for improving pumped hydro storage efficiency by means of buoyancy energy storage according to claim 1, characterized in that: The buoyancy energy storage unit is arranged in a centralized or distributed manner in the water storage unit; the buoyancy energy storage unit also includes an energy transfer and fixing component and a motor, the energy transfer and fixing component is responsible for limiting and fixing the float and the motor and transmitting energy; the float has two motion states, submerging and surfacing, and two storage states, floating and bottom fixed.

3. The method for improving pumped hydro storage efficiency by means of buoyancy energy storage according to claim 2, characterized in that: The power transmission and transformer station unit and the buoyancy energy storage unit are connected by motors. The power transmission and transformer station unit transmits excess energy from the power grid and wind and solar power grids to the pumped storage system. The electrical energy generated by the buoyancy energy storage unit is used to power the pumped storage system for pumping operations via the transmission and transformer station unit; or the electrical energy generated by the buoyancy energy storage unit is used to submerge the floating body in the buoyancy energy storage unit via the transmission and transformer station unit, converting the electrical energy into buoyancy potential energy for storage; the electrical energy generated by the buoyancy energy storage unit is also directly transmitted to the power grid via the transmission and transformer station unit.

4. The method for improving pumped hydro storage efficiency by means of buoyancy energy storage according to claim 1, characterized in that: The buoyancy energy storage unit adopts different buoyancy energy storage methods depending on the geographical and climatic location of the water storage unit; the motor of the buoyancy energy storage unit is set outside the water storage unit, at the bottom of the water storage unit, or as a whole with the float; the float is a low flow resistance rigid pressure-resistant float or a low flow resistance elastic float with compressed volume.

5. The method for improving pumped hydro storage efficiency by means of buoyancy energy storage according to claim 1, characterized in that: The terms "higher level water storage unit" and "lower level water storage unit" refer to the relative height of the water storage units. For a broad interpretation, both the higher level water storage unit and the lower level water storage unit contain at least one water storage unit. When the lower level water storage unit contains multiple water storage units, the arrangement of its floats must meet the following requirements: 1) After reaching the dead reservoir water level line, all floats of the lower level water storage unit will significantly push the water below the dead reservoir water level line into the water above the dead reservoir water level line; 2) When water from the lower level water storage unit is pushed into the higher level water storage unit, the water level of the higher level water storage unit being pushed into must not exceed the full water level line of the higher level water storage unit being pushed into.

6. The method for improving pumped hydro storage efficiency by means of buoyancy energy storage according to claim 1, characterized in that: The method is applicable to all scenarios that operate based on the pumped storage principle, including water tanks, mine shafts, and pumped storage situations involving multiple mine shafts.

7. The method for improving pumped hydro storage efficiency by means of buoyancy energy storage according to claim 1, characterized in that: The monitoring and control unit is used to simultaneously monitor the status of the pumped storage system and the buoyancy storage unit, realizing both pumping and buoyancy monitoring, so that the buoyancy storage unit follows the pumped storage process to improve the pumped storage efficiency.

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