Pump storage power plant with floating pump system

Abstract

The application discloses a floating cylinder type pumping system of pumped storage power station, which comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other and connected by a water delivery pipe; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a pumping and power generation integrated machine, which pumps water from the second reservoir to the first reservoir in the electricity valley period to clean the reservoir capacity of the second reservoir; the water flow of the first reservoir is used to generate power in the electricity peak period; the pumping and power generation integrated machine is connected with a telescopic water guide pipe which is connected with the water delivery pipe; the pumping and power generation integrated machine is located in a floating cylinder platform supported by floating cylinders, the floating cylinder platform can change height with the water level change of the water surface of the second reservoir; and the water guide pipe has telescopic property and can change length with the lifting of the floating cylinder platform.

Description

Technical Field

[0001] This invention belongs to the field of physical energy storage in power systems, and relates to a float-type pumping system for a pumped storage power station. Background Technology

[0002] With the continuous advancement of new power system construction, the power system is characterized by a high proportion of renewable energy and a high proportion of power electronic equipment. However, renewable energy power generation technologies such as wind and solar power have drawbacks such as instability, randomness, and intermittency, making them prone to supply-demand mismatch problems. Specifically, wind power and solar power plants generate the most electricity in the early morning and at noon, respectively, while peak electricity consumption occurs at 10 am and 8 pm. There is a significant mismatch between the peak power generation periods and peak electricity consumption periods. This mismatch between peak power generation and peak electricity consumption results in the waste of excess electricity that cannot be used during peak power generation, while peak electricity consumption periods are precisely when power generation is not peak, leading to a situation where the grid load is high and the supply is insufficient. In addition, seasonal and weather factors will also increase the instability of renewable energy power generation. As the proportion of volatile and intermittent renewable energy in the power structure continues to increase, the supply side will also exhibit random fluctuations. Grid frequency control is becoming increasingly important, and the demand for peak shaving and frequency regulation is becoming more urgent. An effective way to solve this problem is to use power storage systems to store the large amount of surplus low-priced electricity during peak power generation periods. Power storage systems can be used to smooth the output of power generation and to smooth peak and valley loads, thereby balancing the grid load.

[0003] Electricity storage encompasses various methods, including mechanical storage, electrochemical storage, electromagnetic storage, thermal storage, and chemical storage. Electrochemical storage most commonly utilizes a large number of batteries for charging and discharging, while mechanical storage includes common methods such as pumped hydro storage, gravity storage, and compressed air storage. Pumped hydro storage, a type of gravity storage, utilizes the surplus low-cost electricity on the grid during peak power generation periods to pump water to a higher reservoir (such as a hilltop reservoir). During peak electricity demand, the water is then diverted to a generator to generate electricity, leveraging the water's potential energy. A common hilltop reservoir storage method involves pumping water from a low-lying area to a reservoir at a higher elevation, such as a hilltop. During peak electricity demand, the water is released to power a hydroelectric generator. Another method utilizes natural resources like lakes, caves, or mines, diverting water from higher-lying rivers or lakes to the lower mines for power generation. This approach, utilizing naturally formed advantageous terrain or adhering to the principle of secondary utilization, can significantly reduce the construction cost of energy storage power stations and further improve profit margins. This method has been widely developed and used in recent years because surveys have revealed the existence of such favorable terrain in many parts of my country. However, unlike the traditional method of artificially constructing reservoirs at high altitudes, where the generator impeller is located below and the water driving the impeller into low-lying rivers or natural lakes has almost no impact on the water level below the impeller, the situation is different in low-lying areas such as mine pits. Taking the construction of energy storage power stations in mine pits as an example, since mine pits generally have limited storage capacity, the water level in the pit will gradually rise as hydroelectric power generation continues. At this point, the generator impeller, located at the lowest point to maximize the utilization of hydraulic potential energy, will gradually sink into the water, creating operational resistance and reducing operating efficiency. Furthermore, during pumping, excessively long water pipes also reduce the pump's head capacity and increase energy consumption. Energy storage power stations generate profits by taking advantage of the price difference between peak and off-peak electricity demand, and therefore are very sensitive to their own operational efficiency. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a float-type pumping system for a pumped storage power station, which can change the position of the generator at any time according to the change of water level, thereby improving operating efficiency.

[0005] To solve the above problems, the present invention provides a float-type pumping system for a pumped storage power station. The pumped storage power station includes a first reservoir and a second reservoir that are independent of each other but adjacent to each other. The water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than that of the first reservoir to ensure sufficient head for power generation. A water pipe connects the first reservoir and the second reservoir for water flow.

[0006] The pump-generator is a combined pumping and power generation unit. The impeller of the pump-generator is located below the end of the water guide pipe of the second reservoir for pumping or power generation. The other end of the water guide pipe is connected to the water supply pipe. The water guide pipe is flexible and its length can be changed.

[0007] During off-peak electricity demand periods, the pump-generator operates in pumping mode, with the impeller and the end of the water guide pipe submerged below the water surface of the second reservoir, pumping water from the second reservoir to the first reservoir to clear the capacity of the second reservoir. During peak electricity demand periods, the impeller is positioned above the water surface of the second reservoir, utilizing the water level difference between the first and second reservoirs, with water flowing along the water guide pipe to impact the impeller, thus achieving hydroelectric power generation during peak electricity demand periods.

[0008] The pumping and power generation unit is located in a floating platform with a pontoon structure. The pontoon platform is buoyed by no fewer than two pontoons, so that the entire pontoon platform floats on the water surface of the second reservoir.

[0009] The peak and off-peak electricity consumption periods refer to the load status of the external public power grid; the peak electricity consumption period is the power generation phase of the pumped storage power station, and the off-peak electricity consumption period is the energy storage phase of the pumped storage power station.

[0010] Furthermore, the first reservoir is a natural river channel, lake, or other natural water resource whose capacity can be considered unlimited, and the impact of its water level fluctuations on the pumped storage power station is negligible.

[0011] Furthermore, the second reservoir is lower than the first reservoir and has a sufficient drop to the first reservoir for hydroelectric power generation; the second reservoir is a mine pit, pond, cave, or other water-storing landform with a certain storage capacity located in a low-lying area; the second reservoir serves as the water storage facility for a pumped storage power station.

[0012] Furthermore, the pumped storage power station also includes a control system, which is connected to the pumped generator and the floating platform to monitor their working status and control their operation.

[0013] Furthermore, the water supply pipe between the first reservoir and the second reservoir is also equipped with a first electric gate valve, which is controlled by the control system to regulate the water flow between the first reservoir and the second reservoir.

[0014] Furthermore, an actuation device is also installed on the floating platform. When the actuation device is in power generation mode, it raises the impeller of the pump-generator to above the water surface of the second reservoir to reduce the rotational resistance of the impeller. When the pumped-storage power station is in energy storage mode, the actuation device lowers the impeller of the pump-generator to below and close to the water surface of the second reservoir to ensure pumping efficiency.

[0015] The aforementioned actuation device is controlled by the control system and adjusted according to the working status of the pumped storage power station.

[0016] Furthermore, the aforementioned pump-generator can also be adjusted to allow the pump and generator to operate independently, each connected to a retractable water pipe to complete the pumping or power generation work.

[0017] Furthermore, the water guide pipe has a telescopic structure, and its length can be adjusted as the float platform fluctuates with the water level of the second reservoir.

[0018] Furthermore, the water pipe is a multi-stage diameter gradually changing sleeve-type telescopic structure, or a corrugated pipe, or a pipe with similar functions.

[0019] The floating pumping system of the pumped storage power station described in this invention sets the pumping and generating unit of the pumped storage power station on a floating platform that floats on the surface of the second reservoir. The floating platform can move up and down with the water level, keeping the pump or generator in an optimal operating position at all times, thereby improving operating efficiency and maximizing the energy storage efficiency of the entire pumped storage power station, resulting in higher economic benefits. Attached Figure Description

[0020] Figure 1 This is a simplified schematic diagram of the overall structural layout of the pumped storage power station described in this invention.

[0021] Figure 2 This is a simplified structural diagram of the floating pumping platform described in this invention.

[0022] 1 is the second reservoir (abandoned mine pit, karst cave, etc.), 2 is the pit body, 3 is the telescopic water guide pipe (sleeve), 4 is the first reservoir (river, lake, etc.), 5 is the water conveyance pipe or diversion channel, 6 is the floating platform, 7 is the floating pontoon, 8 is the (electric) valve, 9 is the pumping and power generation unit, 10 is the impeller, 11 is the transmission bevel gear, 12 is the coupling, 13 is the drive gear, and 14 is the rack. Implementation

[0023] The following detailed description, in conjunction with the accompanying drawings, provides specific embodiments of the present invention and clearly and completely describes the technical solutions of the present invention. However, the present invention is not limited to the following embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The advantages and features of the present invention will become clearer from the following description and claims. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise ratios, and are only used for the purpose of conveniently and clearly illustrating the embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] This invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated, and the same reference numerals denote the same elements throughout. In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the drawings, are only for the convenience of describing this application 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 application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] The pumped-storage power station described in this invention is an energy storage system built primarily using the natural environment or abandoned man-made environments. For example... Figure 1 As shown, it includes a first reservoir 4 and a second reservoir 1 that are independent of each other but adjacent to each other; the water level of the first reservoir 4 is higher than that of the second reservoir 1, and the bottom of the second reservoir 1 is much lower than that of the first reservoir to ensure sufficient power generation head; the first reservoir 4 can be a natural river, lake, or other natural water resource, and its water resource capacity can be regarded as an infinite water resource for this energy storage power station system, and the impact of its water level fluctuation on the pumped storage power station of the present invention is negligible.

[0026] The second reservoir 1 is located lower than the first reservoir 4 and has a sufficient water level difference with the first reservoir for hydroelectric power generation. The second reservoir 1 is an abandoned mine pit, pond, natural deep pit, cave, or other water-storing landform with a certain storage capacity located in a low-lying area; the second reservoir 1 serves as the water storage facility for a pumped storage power station.

[0027] The first reservoir and the second reservoir are connected by a water conveyance pipe or a diversion channel, the connection method being unrestricted. The water conveyance pipe is equipped with valves or electric valves, controlled by a control system to open and close or control the flow rate. If necessary, the water flow between the first and second reservoirs can be adjusted or cut off. Furthermore, since the water level at the inlet of the water conveyance pipe 5 in the first reservoir needs to be different in both the pumping and pumping modes, this can be achieved by using branch pipes with valves. It should be noted that the control system described in the accompanying drawings is not shown but can be installed in the control room of the pumped storage power station.

[0028] The pump-generator 9 combines pumping and power generation functions. Its impeller is located below the end of the water guide pipe 3 of the second reservoir, performing either pumping or power generation. The other end of the water guide pipe 3 is connected to the water supply pipe. The water guide pipe is flexible and its length can be adjusted. A sufficiently small gap exists between the impeller 10 and the water guide pipe 3 to reduce leakage and ensure efficiency during pumping or power generation. This gap can be adjusted using multiple shims of different sizes.

[0029] The pumped-storage generator operates in pumping and energy storage mode during off-peak electricity periods, when electricity prices are lowest. At this time, the impeller and the end of the water guide pipe are submerged below the water surface of the second reservoir, pumping water from the second reservoir to the first reservoir to free up storage space. During peak electricity periods, the energy storage station operates in power generation mode. The impeller is positioned above the water surface of the second reservoir, utilizing the water level difference between the first and second reservoirs. Water flows along the water guide pipe, impacting the impeller and generating hydroelectric power during peak periods. The peak and off-peak electricity periods refer to the load status of the external public power grid; peak periods are the power generation phase of the pumped-storage station, and off-peak periods are the energy storage phase. Power transmission between the impeller and the pumped-storage generator can take various forms; this embodiment uses a bevel gear and coupling connection, and a gearbox can be added if necessary.

[0030] The impeller of the pump-generator is located at the end of the water guide pipe. The water guide pipe has a telescopic structure, and its length can be changed as the float platform fluctuates with the water level of the second reservoir.

[0031] The water pipe is a multi-stage diameter gradually changing sleeve-type telescopic structure, similar to a telescopic antenna, or it can be a corrugated pipe, or a pipe with similar functions.

[0032] The pump-generator unit is located within a floating platform 6 with a pontoon structure. The floating platform 6 is supported by at least two pontoons, providing sufficient buoyancy to allow the entire platform to float stably on the surface of the second reservoir. Therefore, when the second reservoir is in energy storage or power generation mode, its water level constantly changes. The floating platform can automatically rise and fall with the water level of the second reservoir, thereby altering the water level difference between the pump-generator impeller and the first reservoir, achieving high operating efficiency under different working conditions and water levels.

[0033] The control system monitors the working status of the entire pumped storage power station and controls the operation of each subsystem, including the float platform.

[0034] The floating platform is also equipped with an actuation device, including a drive gear 13 and a rack 14. Since the pump-generator has two operating states, and the impeller needs to be in different working positions in these two states, an actuation device is needed to change the relative position of the impeller with respect to the water surface of the second reservoir—whether it is above or below the water surface. By rotating the drive gear 13 and meshing with it on the rack 14, the height difference between the platform supporting the pump-generator and the water surface is changed. The actuation device can raise and lower the entire platform within a certain range, such as... Figure 2 As shown, when the actuating device is in power generation mode, it can raise the impeller of the pump-generator, including the end of the water guide pipe, above the water surface of the second reservoir. When generating electricity, the water flow impacts the impeller to rotate, and the impeller will not be submerged in the water, reducing the rotational resistance of the impeller. When the pumped-storage power station is in energy storage mode, that is, pumping water into the first reservoir, the actuating device lowers the platform, and the impeller of the pump-generator is lowered below the water surface of the second reservoir and close to the water surface. This avoids immersing the impeller in the water too deeply, which would result in an unnecessaryly long water guide pipe, thus improving the pumping efficiency.

[0035] The actuation device is controlled by the control system and adjusted according to the operating status of the pumped storage power station. The drive gear 13 of the actuation device can be directly driven by a hydraulically driven impeller, or it can be driven by an additional drive motor.

[0036] The pump-generator integrated unit used in this embodiment is a commonly used design that integrates the water pump and the generator together. In some application scenarios, it can be adjusted to allow the water pump and the generator to work independently, each connected to a retractable water pipe to complete the work of pumping water or generating electricity.

[0037] Since the floating platform drifts on the water surface of the second reservoir, to prevent it from moving around freely, it can be secured with steel cables or a vertical limiting guide rod structure. This structure restricts the platform's movement, limiting its vertical movement to only adjust with water level changes and preventing horizontal displacement. Designers need to design these options according to their specific circumstances; further details are omitted here.

[0038] The floating pumping system of the pumped storage power station described in this invention sets the pumping and generating unit of the pumped storage power station on a floating platform that floats on the surface of the second reservoir. The floating platform can move up and down with the water level, keeping the pump or generator in an optimal operating position at all times, thereby improving operating efficiency and maximizing the energy storage efficiency of the entire pumped storage power station, resulting in higher economic benefits.

[0039] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A floating-pontoon pumped hydro storage system of a pumped hydro storage power plant, characterized in that: The pumped storage power station comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a water delivery pipe is arranged between the first reservoir and the second reservoir to allow water flow between the two reservoirs. The pumped storage power station comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a water delivery pipe is arranged between the first reservoir and the second reservoir to allow water flow between the two reservoirs. The pumped storage power station comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a water delivery pipe is arranged between the first reservoir and the second reservoir to allow water flow between the two reservoirs. The pumped storage power station comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a water delivery pipe is arranged between the first reservoir and the second reservoir to allow water flow between the two reservoirs. The pumped storage power station comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a water delivery pipe is arranged between the first reservoir and the second reservoir to allow water flow between the two reservoirs.

2. The floating-pump system of pumped hydro energy storage plant of claim 1, wherein: The pumped storage power station comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a water delivery pipe is arranged between the first reservoir and the second reservoir to allow water flow between the two reservoirs.

3. The floating-pump system of pumped hydro energy storage plant of claim 2, wherein: The pumped storage power station comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a water delivery pipe is arranged between the first reservoir and the second reservoir to allow water flow between the two reservoirs.

4. The floating-pump system of pumped hydro energy storage plant of claim 1, wherein: The pumped storage power station comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a water delivery pipe is arranged between the first reservoir and the second reservoir to allow water flow between the two reservoirs.

5. The floating-pump system of pumped hydro energy storage plant of claim 4, wherein: The pumped storage power station comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a water delivery pipe is arranged between the first reservoir and the second reservoir to allow water flow between the two reservoirs.

6. The floating-pump system of pumped hydro energy storage plant of claim 4, wherein: The pumped storage power station comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a water delivery pipe is arranged between the first reservoir and the second reservoir to allow water flow between the two reservoirs. The pumped storage power station comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a water delivery pipe is arranged between the first reservoir and the second reservoir to allow water flow between the two reservoirs. The pumped storage power station comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a water delivery pipe is arranged between the first reservoir and the second reservoir to allow water flow between the two reservoirs. The pumped storage power station comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a water delivery pipe is arranged between the first reservoir and the second reservoir to allow water flow between the two reservoirs. The pumped storage power station comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a water delivery pipe is arranged between the first reservoir and the second reservoir to allow water flow between the two reservoirs. The pumped storage power station comprises a first reservoir and a second reservoir which are independent of each other and adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than the water level of the first reservoir to ensure sufficient power generation fall; a water delivery pipe is arranged between the first reservoir and the second reservoir to allow water flow between the two reservoirs.

7. The floating-pump system of pumped hydro energy storage plant of claim 1, wherein: The water pumping and power generating integrated machine can also replace the water pump for pumping water and the power generator for generating power in the independent working mode.

8. The floating-pump system of pumped hydro energy storage plant of claim 1, wherein: The water guide pipe is of a telescopic structure, and when the floating platform fluctuates with the water level of the second reservoir, the water guide pipe can change its length by following the floating platform.

9. The floating-pump system of pumped hydro energy storage plant of claim 8, wherein: The water guide pipe is of a telescopic structure with multiple levels of gradually changed diameters, or is a bellows.

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