An Offshore Energy Storage Device for Wind Power Generation and Its Dynamic Regulation Method

Abstract

The present invention discloses a deep-sea energy storage device for wind power generation and a dynamic regulation method, which mainly includes a wind power generation system, a gear transmission conversion box, a compression-expansion cascade device, a regenerative system, and a variable-volume pressure-resistant energy storage tank. Based on compressed air energy storage technology, the present invention recovers and utilizes wind energy to weaken the peak of the power grid load and fill the valley of the power load, reduce the peak-valley difference of the power grid load, and achieve the balance between power generation and power consumption. The present invention adopts a positive displacement compression-expansion machine and a step-by-step parallel alternating heat exchange to reduce the system scale and investment cost; the compression-expansion cascade device is placed in the foundation and has the same height as the variable-volume pressure-resistant energy storage tank to reduce the flow resistance and energy consumption of air transportation; the variable-volume pressure-resistant energy storage tank flexibly adjusts its volume according to the amount of injected air to maintain the working pressure of the compression-expansion cascade device constant; mechanical transmission components such as transmission gears, transmission shafts, and racks are used to keep the system always realizing energy transfer and conversion in the form of mechanical energy.

Description

Technical Field

[0001] The present invention belongs to the technical field of compressed air energy storage, and particularly relates to a deep-sea energy storage device for wind power generation and a dynamic regulation method. Background Art

[0002] The randomness, intermittency, and volatility of renewable energy seriously affect its recovery and utilization, as well as the large-scale grid connection of electricity. The application of energy storage technology in renewable energy power generation systems can ensure the voltage, frequency, and phase of renewable energy power to match those of the power grid, reduce the damage of renewable energy power fluctuations to the power grid, and improve grid connection safety.

[0003] Among them, compressed air energy storage technology is considered to be one of the most promising large-scale energy storage technologies due to its advantages of clean pollution-free, low cost, and long life cycle. However, compressed air energy storage technology still has limitations:

[0004] 1. It is difficult to create a suitable high-pressure environment in nature to store high-pressure air; existing large-scale compressed air energy storage systems usually use underground caves, open valleys, or abandoned mine shafts as natural compressed air energy storage tanks, which are easily restricted by geographical conditions;

[0005] 2. In conventional compressed air energy storage technology, mechanical energy and electrical energy are frequently converted into each other, resulting in increased energy loss; the air delivery pipeline of a conventional compressed air energy storage system extends from the compressed air equipment to the bottom of an underground cave, valley, or mine shaft, with a long delivery distance, large air resistance, and serious energy consumption for transportation;

[0006] 3. The compression process and expansion process of conventional compressed air energy storage are independent of each other and require two sets of independent equipment, significantly increasing the system scale and investment cost; the dynamic change of air pressure has an adverse effect on the operation of the compressor and expander; the heat released during the air compression process is not effectively utilized, resulting in serious energy loss. Summary of the Invention

[0007] The technical problem solved by the present invention: The purpose of the present invention is to propose a deep-sea energy storage device for wind power generation and a dynamic regulation method for the problems in the above background art, effectively solving the large-scale grid connection of renewable energy power generation systems and realizing peak shaving and valley filling of power loads.

[0008] The technical solution of the present invention: The present invention discloses a deep-sea energy storage device for wind power generation, including a wind power generation system, a compression-expansion cascade device, and a variable-volume pressure-resistant energy storage tank;

[0009] The wind power generation system includes blades and a generator, and the blades output torque to the generator through a generator transmission shaft;

[0010] The generator drive shaft in the wind power generation system can output torque to the compression-expansion cascade device through a gear transmission conversion box;

[0011] The compression-expansion cascade device compresses air into high-pressure air and stores it in the variable-volume pressure-resistant energy storage tank;

[0012] The variable-volume pressure-resistant energy storage tank provides storage space for high-pressure air and maintains a constant-pressure working condition for the compression-expansion cascade device;

[0013] The variable-volume pressure-resistant energy storage tank reversely drives the compression-expansion cascade device by releasing high-pressure air, converts static pressure energy into mechanical energy, and transports it to the generator drive shaft through the gear transmission conversion box to output torque to the generator.

[0014] Furthermore, the gear transmission conversion box consists of transmission gears, sliding gears, and fixing devices;

[0015] The transmission gears include a first transmission gear connecting the generator drive gear in the generator drive shaft, a second transmission gear connecting the compression-expansion machine drive gear in the compression-expansion cascade device, and a third transmission gear;

[0016] The third transmission gear meshes with the second transmission gear;

[0017] The positions of the sliding gears include an empty gear position a where they do not contact the transmission gears, a working gear position b where they mesh with the first transmission gear and the second transmission gear, and a reverse working gear position c where they mesh with the first transmission gear and the third transmission gear.

[0018] Furthermore, the first transmission gear is connected to the wind power generation system through a first rack; the first rack meshes with the generator drive gear on the generator drive shaft;

[0019] The second transmission gear is connected to the compression-expansion cascade device through a second rack; the second rack meshes with the compression-expansion machine drive gear on the compression-expansion machine drive shaft.

[0020] Furthermore, the compression-expansion cascade device includes several groups of compression-expansion machines, and adjacent compression-expansion machines are connected through a regenerator; the outlet end of the regenerator at the end of the several groups of compression-expansion machines is connected to the variable-volume pressure-resistant energy storage tank;

[0021] One side of several regenerators is provided with a water circulation pipeline, and the heat energy in the several regenerators is transferred to the heat storage tank through heat exchange in the water circulation pipeline.

[0022] Furthermore, the contraction-expansion cascade device includes a first-stage compression-expanding machine, a second-stage compression-expanding machine, and a third-stage compression-expanding machine;

[0023] The heat recovery system includes a first-stage heat regenerator, a second-stage heat regenerator and a third-stage heat regenerator;

[0024] A first-stage regenerator is connected between the first-stage compression expander and the second-stage compression expander;

[0025] A second-stage regenerator is connected between the second-stage compression expander and the third-stage compression expander;

[0026] A third-stage regenerator is connected between the third-stage compression expander and the variable volume pressure-resistant energy storage tank;

[0027] The water circulation pipeline forms an independent circulation with the first stage heat regenerator, the second stage heat regenerator and the third stage heat regenerator respectively.

[0028] Furthermore, it also includes an internal hollow tower supporting the wind power generation system and a foundation arranged at the bottom of the tower;

[0029] The compression-expansion cascade device and the heat recovery system are both arranged in the foundation;

[0030] The variable volume pressure-resistant energy storage box is arranged adjacent to the outside of the foundation;

[0031] The tower has an opening for air circulation on the side, and a rain shield is installed on the upper end of the tower opening;

[0032] The foundation is set in the deep sea and is connected to the outside world through a tower above the sea surface, so that the tower and the interior of the foundation are kept at normal temperature and pressure.

[0033] Furthermore, the tower has an opening for air circulation on the side; a rain shield is installed at the upper end of the tower opening; and the gear transmission conversion box is placed inside the tower.

[0034] Furthermore, the variable volume pressure-resistant energy storage box includes two parallel pressure-resistant steel plates and a pressure-resistant flexible rubber surrounding the two pressure-resistant steel plates; the pressure-resistant steel plates and the pressure-resistant flexible rubber form a flexible variable volume cavity for storing high-pressure air;

[0035] The high-pressure air is injected into the variable-volume pressure-resistant energy storage tank from the compression-expansion cascade device along the air circulation pipeline;

[0036] The air circulation duct is a high-pressure resistant hose and can be freely folded and bent based on the variable-volume pressure-resistant energy storage box.

[0037] The present invention also discloses a dynamic regulation method for a deep - sea energy storage device for wind power generation, including the above - mentioned deep - sea energy storage device for wind power generation and the following methods.

[0038] During the low - valley period of grid power supply, the wind power generation system converts the excess mechanical energy into static pressure energy through the compression - expansion cascade device and stores it in the variable - volume pressure - resistant energy storage tank in the form of high - pressure air.

[0039] During the peak period of grid power supply, the variable - volume pressure - resistant energy storage tank converts the stored static pressure energy of high - pressure air into additional mechanical energy through the compression - expansion cascade device to drive the wind power generation system to work.

[0040] During the period of balanced grid power supply demand, the connection between the wind power generation system, the compression - expansion cascade device, and the variable - volume pressure - resistant energy storage tank is cut off, and the compressed - air energy storage and the expansion - air energy release are stopped.

[0041] Furthermore, it also includes a data acquisition controller.

[0042] During the low - valley period of grid power supply, the data acquisition controller controls the sliding gear to move to the working gear position b of the chute, connecting the first transmission gear and the second transmission gear, including the following steps:

[0043] S11. The blades and hub of the wind power generation system recover wind energy and convert it into mechanical energy, driving the generator drive shaft to rotate forward. A part of the mechanical energy drives the generator to perform the power - generation task.

[0044] S12. The generator drive shaft (104) rotates forward, driving the generator (106) to perform the power - generation task. At the same time, the mechanical energy generated by the forward rotation of the generator drive shaft (104) is transmitted to the compression - expansion machine drive gear through the generator drive gear, the first rack, the gear - transmission conversion box, and the second rack, providing the forward - rotation power for the compression - expansion machine drive shaft.

[0045] S13. The forward rotation of the compression - expansion machine drive shaft drives the compression - expansion cascade device to work, performing the task of compressed - air energy storage, and delivering the generated high - pressure air to the variable - volume pressure - resistant energy storage tank.

[0046] During the peak period of grid power supply, the data acquisition controller controls the sliding gear to move to the reverse working gear position c of the chute, connecting the first transmission gear and the third transmission gear, including the following steps:

[0047] S21. The high - pressure air flows from the variable - volume pressure - resistant energy storage tank into the compression - expansion cascade device, driving the compression - expansion cascade device to perform the task of expansion - air energy release, and at the same time driving the compression - expansion machine drive shaft to rotate reversely.

[0048] S22. The power of the reverse rotation of the transmission shaft of the compression-expansion machine is transmitted along the transmission gear of the compression-expansion machine, the second rack, the gear transmission conversion box and the first rack to the generator transmission gear, providing an additional power for the generator transmission shaft to accelerate the rotation of the generator transmission shaft;

[0049] S23. The generator transmission shaft simultaneously obtains the mechanical energy converted from wind energy and the static pressure energy of compressed air, and drives the generator to perform the power generation task;

[0050] During the period of power grid power supply demand balance, the data acquisition controller controls the sliding gear to move to the empty gear position a of the chute, cuts off the mechanical transmission between the first transmission gear and the second transmission gear and the third transmission gear, and stops the operation of the compression-expansion cascade device and the variable-volume pressure-resistant energy storage tank.

[0051] Beneficial effects

[0052] 1. The present invention discloses a deep-sea energy storage device for wind power generation, including a wind power generation system, a gear transmission conversion box, a compression-expansion cascade device, a regenerative heat system and a variable-volume pressure-resistant energy storage tank. The wind power generation system provides mechanical energy for the compression-expansion cascade device to compress air and store it in the variable-volume pressure-resistant energy storage tank, ensuring that the renewable energy power matches the voltage, frequency and phase of the power grid, reducing the damage of the renewable energy power fluctuation to the power grid, and improving the grid connection safety.

[0053] 2. By regulating the wind power generation system, the compression-expansion cascade device and the variable-volume pressure-resistant energy storage tank, the present invention always maintains the form of energy transfer and conversion as mechanical energy during the processes of compressed air energy storage and expanded air energy release, thereby effectively reducing the energy loss caused by the frequent conversion between mechanical energy and electrical energy due to the intermittency of renewable energy, reducing the response time required for energy conversion, and keeping the operating characteristics of the air compression energy storage device always within the best range.

[0054] 3. The present invention discloses a control method for the deep-sea energy storage device for wind power generation. By controlling the position of the sliding gear in the chute of the gear transmission conversion box through the data acquisition controller, controlling the compression-expansion cascade device to perform the tasks of compressed air energy storage and expanded air energy release, and dynamically switching the conversion and transmission directions between mechanical energy and static pressure energy, the peak of the power load is weakened and the valley of the power load is filled, the peak-valley difference of the power grid load is reduced, and the balance between power generation and power consumption is achieved.

[0055] 4. Since the positive-displacement turbine in the pumped storage power station can play the roles of both a water turbine and a water pump under high-pressure working conditions, the present invention considers using a set of positive-displacement compression-expansion cascade device, which is used for both air compression energy storage and air expansion energy release under high-pressure working conditions, greatly simplifying the system process, reducing the system scale, and improving the economic benefits.

[0056] 5. The regenerative system of the present invention is connected to the compression-expansion cascade device, effectively recovering the heat released during the compressed air energy storage process and using it for preheating during the expansion air energy release process, significantly reducing the cyclic energy loss. Among them, the regenerative system adopts a step-by-step parallel alternating heat exchange method, enabling the positive-displacement compression-expansion dual-purpose machine to cool the inlet air temperature to the lowest and preheat it to the highest as much as possible during the compressed air energy storage and expansion air energy release processes respectively, thereby significantly enhancing the working efficiency of the compression-expansion cascade device, improving the conversion ability between mechanical energy and static pressure energy, and further reducing the energy loss during the compressed air energy storage and expansion air energy release processes.

[0057] 6. The tower and foundation of the present invention are filled with air at normal temperature and pressure. The compression-expansion cascade device can be in direct contact with the air at normal temperature and pressure hundreds of meters deep in the sea, thus ignoring the transportation energy consumption of air from land to hundreds of meters deep in the sea and solving the problems of long air transportation pipelines and large air resistance in the prior art. At the same time, the variable-volume pressure-resistant energy storage tank is placed on one side of the compression-expansion cascade device, significantly reducing the flow resistance of compressed air transportation in the high-pressure environment hundreds of meters deep in the sea and improving the safety and service life of the deep-sea compressed energy storage system.

[0058] 7. For the variable-volume pressure-resistant energy storage tank of the present invention, taking the deep sea as a natural high-pressure environment significantly reduces the investment cost for creating a high-pressure environment and maintaining the energy storage tank. By adjusting the depth of the variable-volume pressure-resistant energy storage tank in the deep sea, the ability of the variable-volume pressure-resistant energy storage tank to store compressed air by itself can be adjusted. The variable-volume pressure-resistant energy storage tank flexibly adjusts the volume of the energy storage tank according to the amount of injected air, so that the air flow pipeline pressure between the variable-volume pressure-resistant energy storage tank and the third-stage compression-expansion machine remains constant, thereby keeping the air pressures at the inlet and outlet of the compression-expansion cascade device constant. Subsequently, the optimal compression ratio and expansion ratio of each stage of the compression-expansion machine correspond to fixed inlet and outlet pressures, and then keep the air pressures at the inlet and outlet of each stage of the compression-expansion machine constant, so that the compression-expansion cascade device is always in the best operating condition, effectively solving the negative impact of the dynamic change of air pressure in the prior art on the compression-expansion cascade device during the compressed air energy storage and expansion air energy release processes, and significantly improving the overall working efficiency of the compression-expansion cascade device. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is the schematic diagram of the deep-sea energy storage device for wind power generation in the present invention;

[0060] Figure 2 It is the structural schematic diagram of the wind power generation system in the present invention;

[0061] Figure 3 It is the structural schematic diagram of the gear transmission conversion box in the present invention;

[0062] Figure 4Schematic diagram of the working process of compressed air energy storage in the present invention;

[0063] Figure 5 Schematic diagram of the working process of expanding air energy release in the present invention;

[0064] Figure 6 Schematic diagram of the structure of the variable-volume pressure-resistant energy storage tank in the present invention.

[0065] Wherein: 1 - wind power generation system, 2 - first rack, 3 - second rack, 4 - gear transmission conversion box, 5 - air filter, 6 - compression-expansion cascade device, 7 - regenerative system, 8 - variable-volume pressure-resistant energy storage tank, 9 - data acquisition controller, 10 - tower, 11 - foundation, 12 - rain shield, 13 - ladder, 14 - sea level, 101 - blade, 102 - hub, 103 - generator gearbox, 104 - generator drive shaft, 105 - generator drive gear, 106 - generator, 401 - first drive gear, 402 - second drive gear, 403 - third drive gear, 404 - sliding gear, 405 - fixed block, 406 - slider, 407 - fixed plate, 408 - chute, 601 - compression-expansion machine drive gear, 602 - compression-expansion machine drive shaft, 603 - air flow pipeline, 604 - first-stage compression-expansion machine, 605 - second-stage compression-expansion machine, 606 - third-stage compression-expansion machine, 607 - check valve, 701 - first-stage regenerator, 702 - second-stage regenerator, 703 - third-stage regenerator, 704 - water circulation pipeline, 705 - three-way valve, 706 - water pump, 707 - heat storage tank, 801 - pressure-resistant steel plate, 802 - pressure-resistant flexible rubber, 803 - high-pressure air, 804 - fixed support. Detailed implementation manners

[0066] As Figure 1 shown, a deep-sea energy storage device for wind power generation mainly includes a wind power generation system 1, a first rack 2, a second rack 3, a gear transmission conversion box 4, an air filter 5, a compression-expansion cascade device 6, a regenerative system 7, a variable-volume pressure-resistant energy storage tank 8, a data acquisition controller 9, a tower 10, a foundation 11, a rain shield 12, a ladder 13, and a number of drive gears, drive shafts, regenerators, pipelines, elbows, valves and pumps.

[0067] Among them, the wind power generation system 1 provides mechanical energy for the compression-expansion cascade device 6 to compress air and store it in the variable-volume pressure-resistant energy storage tank 8;

[0068] The gear transmission conversion box 4, the first rack 2 and the second rack 3 are used to transmit mechanical energy between the wind power generation system 1 and the compression-expansion cascade device 6.

[0069] The electric energy generated by the wind power generation system 1 flows into the grid-connected inverter before being connected to the grid, ensuring that the generated electricity matches the voltage, frequency, and phase of the grid, improving the utilization efficiency of renewable energy and the safe grid connection of the power generation system, and reducing the damage to the grid caused by the fluctuations of renewable energy power.

[0070] The wind power generation system 1 is supported by a tower 10 above sea level 14 and a foundation 11 below sea level 14, standing steadily on the sea.

[0071] The tower 10 is at the lower end of the wind power generation system 1; the inside of the tower 10 is hollow, and the first rack 2, the second rack 3, and the gear transmission conversion box 4 are placed inside; there are openings for air circulation on the side; a rain shield 12 is installed at the upper end of the side opening.

[0072] The foundation 11 is at the lower end of the tower 10, and its inside is hollow, where the second rack 3, the air filter 5, the compression-expansion cascade device 6, and the regenerative system 7 are placed; on the left side, an air circulation pipe 603 runs through and a fixed bracket 804 for inlaying the variable-volume pressure-resistant energy storage tank 8 is provided.

[0073] As Figure 2 shown, the wind power generation system 1 includes a blade 101, a hub 102, a generator gearbox 103, a generator drive shaft 104, a generator drive gear 105, and a generator 106.

[0074] The blade 101 and the hub 102 form a wind energy recovery device and are installed outside the wind power generation system 1; the generator gearbox 103, the generator drive shaft 104, and the generator drive gear 105 form a mechanical energy transmission device and are installed inside the wind power generation system 1; the generator 106 is connected to the generator drive shaft 104 and serves as a conversion device between mechanical energy and electrical energy.

[0075] As Figure 3 shown, the gear transmission conversion box 4 is composed of a transmission gear, a sliding gear, and a fixing device.

[0076] The first rack 2 meshes with the generator drive gear 105 of the wind power generation system 1 and the first transmission gear 401 of the gear transmission conversion box 4 respectively, and the second rack 3 meshes with the compression-expansion machine drive gear 601 of the compression-expansion machine drive gear 6 and the second transmission gear 402 of the gear transmission conversion box 4 respectively.

[0077] The first transmission gear 401, the second transmission gear 402, and the third transmission gear 403 are transmission components and are fixed inside the gear transmission conversion box 4 through fixing blocks 405; the sliding gear 404 is a rotating switching component and is fixed inside the gear transmission conversion box 4 through a slider 406; the chute 408 is fixed inside the gear transmission conversion box 4 through a fixing piece 407.

[0078] The positions of the sliding gear 404 include the neutral positions a and d where it does not contact the transmission gear, the working position b where it meshes with the first transmission gear 401 and the second transmission gear 402, and the reverse working position c where it meshes with the first transmission gear 401 and the third transmission gear 403.

[0079] The sliding gear 404 is installed on the sliding groove 408 and can be arbitrarily moved from position a to position d.

[0080] As Figure 4 and 5 shown, the compression-expansion cascade device 6 mainly includes a compression-expansion machine transmission gear 601, a compression-expansion machine transmission shaft 602, and a multi-stage compression-expansion machine; the regenerative system 7 mainly consists of a multi-stage regenerator, a water circulation pipeline 704, a water pump 706, and a heat storage tank 707.

[0081] The second rack 3 meshes with the compression-expansion machine transmission gear 601; the compression-expansion machine transmission gear 601 is installed on the compression-expansion machine transmission shaft 602; the compression-expansion machine transmission shaft 602 is sequentially connected to the first-stage compression-expansion machine 604, the second-stage compression-expansion machine 605, and the third-stage compression-expansion machine 606.

[0082] An air circulation pipeline 603 installs an air filter 5 at the inlet of the compression-expansion cascade device 6 and installs a check valve 607 at the outlet of the compression-expansion cascade device 6; the air circulation pipeline 603 sequentially injects air into the first-stage compression-expansion machine 604, the second-stage compression-expansion machine 605, and the third-stage compression-expansion machine 606; the air circulation pipeline 603 is welded at the penetration point of the foundation 11.

[0083] A three-way valve 705, a water pump 706, and a heat storage tank 707 are installed on the water circulation pipeline 704; both sides of the first-stage regenerator 701, the second-stage regenerator 702, and the third-stage regenerator 703 are respectively connected to the air circulation pipeline 603 and the water circulation pipeline 704.

[0084] As Figure 6 shown, the variable-volume pressure-resistant energy storage tank 8 is composed of a pressure-resistant steel plate 801, a pressure-resistant flexible rubber 802, and a fixing bracket 804.

[0085] The upper and lower sides of the variable-volume pressure-resistant energy storage tank 8 are pressure-resistant steel plates 801; the periphery of the variable-volume pressure-resistant energy storage tank 8 is covered with a pressure-resistant flexible rubber 802; the variable-volume pressure-resistant energy storage tank 8 is fixed to the foundation 11 through the fixing bracket 804; the air circulation pipeline 603 is welded at the penetration point of the variable-volume pressure-resistant energy storage tank 8.

[0086] The pressure-resistant steel plate 801 is tightly wrapped by the pressure-resistant flexible rubber 802 to form a flexible variable-volume cavity; the flexible variable-volume cavity is used to store high-pressure air 803.

[0087] The working processes of a deep - sea energy storage device for wind power generation of the present invention in three states (low - valley period of grid power supply, peak period of grid power supply, and balanced period of grid power demand) are as follows.

[0088] During the low - valley period of grid power supply, which mostly occurs at night when electricity is cheap, as Figure 4 shown. First, the blades 101 and the hub 102 collect the external wind energy and convert it into mechanical energy. A part of the mechanical energy drives the generator 106 to rotate forward, converting the mechanical energy into electrical energy and transmitting it to the external high - voltage power line; another part of the mechanical energy is transmitted through the generator drive gear 105 on the generator drive shaft 104 and the first rack 2 on the generator drive gear 105 to the gear transmission conversion box 4, driving the first transmission gear 401 to rotate forward.

[0089] At this time, the sliding gear 404 of the gear transmission conversion box 4 moves to the working gear position b of the chute 408, and the first transmission gear 401 and the second transmission gear 402 are connected, transmitting the mechanical energy along the second rack 3 to the compression - expansion machine drive gear 601.

[0090] Subsequently, the compression - expansion machine drive gear 601 drives the compression - expansion machine drive shaft 602 to rotate forward, driving the first - stage compression - expansion machine 604, the second - stage compression - expansion machine 605, and the third - stage compression - expansion machine 606 to perform the compressed - air energy - storage task:

[0091] The normal - temperature and normal - pressure air inside the tower 10 and the foundation 11, under the adsorption force of the compression - expansion cascade device 6, first passes through the air filter 5 along the air circulation pipeline 603 and then enters the first - stage compression - expansion machine 604 of the compression - expansion cascade device 6; after performing the first - stage compressed air, the low - temperature and low - pressure air is transformed into high - temperature and high - pressure air, and then enters the first - stage regenerator 701 of the regenerative system 7 and is cooled by the cold water in the water circulation pipeline 704.

[0092] The low - temperature and high - pressure air flowing out of the first - stage regenerator 701 then successively enters the second - stage compression - expansion machine 605, the second - stage regenerator 702, the third - stage compression - expansion machine 606, and the third - stage regenerator 703, performing the tasks of air - stage compression and cooling, realizing the energy conversion between mechanical energy and static pressure energy, and thus storing a part of the mechanical energy used for power generation in the form of static pressure energy in the high - pressure air 803.

[0093] Finally, the one - way valve 607 is opened, and the high - pressure air 803 flows along the air circulation pipeline 603 into and is stored in the variable - volume pressure - resistant energy - storage tank 8, and the volume of the variable - volume pressure - resistant energy - storage tank 8 increases.

[0094] During the peak period of grid power supply, which mostly occurs during the day when electricity is expensive, as Figure 5As shown. First, open the one-way valve 607, and the high-pressure air 803 stored in the variable-volume pressure-resistant energy storage tank 8 enters the third-stage regenerator 703 of the regenerative system 7 along the air flow pipeline 603, and the volume of the variable-volume pressure-resistant energy storage tank 8 decreases.

[0095] Subsequently, the high-pressure air 803 is preheated by the hot water in the air flow pipeline 603 in the third-stage regenerator 703, and then flows into the third-stage compression-expansion machine 606 of the compression-expansion cascade device 6; the static pressure energy contained in the high-pressure air 803 drives the third-stage compression-expansion machine 606 to rotate reversely, realizing the energy conversion between static pressure energy and mechanical energy. After performing the air expansion energy release task, the high-temperature and high-pressure air turns into low-temperature and low-pressure air, and then successively enters the second-stage regenerator 702, the second-stage compression-expansion machine 605, the first-stage regenerator 701, and the first-stage compression-expansion machine 604 to perform the tasks of air preheating and expansion stage by stage. Finally, the low-pressure air flows into the tower 10 and the foundation 11 along the air flow pipeline 603.

[0096] Meanwhile, the compression-expansion cascade device 6 drives the compression-expansion machine drive shaft 602 to rotate reversely, and transmits the mechanical energy through the compression-expansion machine drive gear 601 along the second rack 3 to the second drive gear 402 of the gear drive conversion box 4.

[0097] At this time, the sliding gear 404 moves to the working gear position c of the sliding groove 408, and the reverse rotation of the second drive gear 402 drives the third drive gear 403 to rotate forward, and the third drive gear 403 drives the first drive gear 401 to rotate forward through the sliding gear 404.

[0098] Finally, the first drive gear 401 transmits the mechanical energy along the first rack 2 to the generator drive gear 105, provides an additional thrust for the generator drive shaft 104 to promote its forward acceleration rotation, drives the generator 106 to generate more electricity, and thus converts a part of the static pressure energy stored in the high-pressure air into mechanical energy for power generation.

[0099] During the period of balancing the power grid power supply demand, the sliding gear 404 in the gear drive conversion box 4 moves to the working gear position a or d of the sliding groove 408, cuts off the transmission between the first drive gear 401 and the second drive gear 402, prevents the mechanical energy of the generator drive shaft 104 from being transmitted to the compression-expansion machine drive shaft 602, and stops the operation of the compression-expansion cascade device 6, the regenerative system 7, and the variable-volume pressure-resistant energy storage tank 8.

[0100] Meanwhile, the blade 101 collects the external wind energy and converts it into mechanical energy, which is transmitted along the hub 102 to the generator gearbox 103. With the help of the speed-changing mechanism of the generator gearbox 103, the blade 101 rotating forward at a low speed drives the generator transmission shaft 104 to rotate forward at a high speed, driving the generator 106 to rotate forward and converting all the mechanical energy into electrical energy. The generated electricity is transmitted to the external high-voltage power line.

[0101] The above are only the preferred examples of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and changes can be made to the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An offshore energy storage device for wind power generation, characterized in that: It includes a wind power generation system (1), a compression-expansion cascade device (6) and a variable-volume pressure-resistant energy storage tank (8); The wind power generation system (1) includes blades (101) and a generator (106), and the blades (101) output torque to the generator (106) through a generator transmission shaft (104); In the wind power generation system (1), the generator transmission shaft (104) outputs torque to the compression-expansion cascade device (6) through a gear transmission conversion box (4); The compression-expansion cascade device (6) compresses air into high-pressure air and stores it in the variable-volume pressure-resistant energy storage tank (8); The variable-volume pressure-resistant energy storage tank (8) provides a storage space for the high-pressure air and maintains a constant-pressure working condition for the compression-expansion cascade device (6); The variable-volume pressure-resistant energy storage tank (8) reversely drives the compression-expansion cascade device (6) by releasing high-pressure air, converts static pressure energy into mechanical energy, and transports it to the generator transmission shaft (104) through the gear transmission conversion box (4) to output torque to the generator (106); The gear transmission conversion box (4) consists of transmission gears, a sliding gear (404) and a fixing device; The transmission gears include a first transmission gear (401) connecting the generator transmission gear (105) in the generator transmission shaft (104), a second transmission gear (402) connecting the compression-expansion machine transmission gear (601) in the compression-expansion cascade device (6), and a third transmission gear (403); The third transmission gear (403) meshes with the second transmission gear (402); The position of the sliding gear (404) includes an empty gear position a where it does not contact the transmission gears, a working gear position b where it meshes with the first transmission gear (401) and the second transmission gear (402), and a reverse working gear position c where it meshes with the first transmission gear (401) and the third transmission gear (403).

2. The deep - sea energy storage device for wind power generation according to claim 1, characterized in that: The compression-expansion cascade device (6) includes several groups of compression-expansion machines, and adjacent compression-expansion machines are connected through a regenerator; the outlet end of the regenerator at the end of the several groups of compression-expansion machines is connected to the variable-volume pressure-resistant energy storage tank (8); One side of several of the regenerators is provided with a water circulation pipeline (704), and the heat energy in several of the regenerators is transferred to a heat storage tank (707) through heat exchange in the water circulation pipeline (704).

3. The deep-sea energy storage device for wind power generation according to claim 1, wherein: It also includes an internally hollow tower (10) supporting the wind power generation system (1) and a foundation (11) arranged at the bottom of the tower (10); The compression-expansion cascade device (6) and the regenerative system (7) are both arranged in the foundation (11); The variable-volume pressure-resistant energy storage tank (8) is arranged adjacent to the outside of the foundation (11); The foundation (11) is arranged in a deep-sea environment, communicates with the outside through the tower (10) above the sea surface, and keeps the inside of the tower (10) and the foundation (11) at normal temperature and pressure.

4. The deep-sea energy storage device for wind power generation according to claim 3, wherein: The side of the tower (10) has an opening for air circulation; a rain shield (12) is installed at the upper end of the opening of the tower (10); the gear transmission conversion box (4) is placed inside the tower (10).

5. The deep-sea energy storage device for wind power generation according to claim 1, characterized in that: The variable-volume pressure-resistant energy storage tank (8) includes two parallel pressure-resistant steel plates (801) and pressure-resistant flexible rubber (802) surrounding the two pressure-resistant steel plates (801); the pressure-resistant steel plates (801) and the pressure-resistant flexible rubber (802) form a flexible variable-volume cavity for storing high-pressure air (803); The high-pressure air (803) is injected into the variable-volume pressure-resistant energy storage tank (8) from the compression-expansion cascade device (6) along the air circulation pipeline (603); The air circulation pipeline (603) is a high-pressure-resistant hose that can be freely folded and bent based on the variable-volume pressure-resistant energy storage tank (8).

6. The deep - sea energy storage device for wind power generation according to claim 1, characterized in that: The first transmission gear (401) is connected to the wind power generation system (1) through the first rack (2); the first rack (2) meshes with the generator transmission gear (105) on the generator transmission shaft (104); The second transmission gear (402) is connected to the compression-expansion cascade device (6) through the second rack (3); the second rack (3) meshes with the compression-expansion machine transmission gear (601) on the compression-expansion machine transmission shaft (602).

7. The deep - sea energy storage device for wind power generation according to claim 2, wherein: The compression-expansion cascade device (6) includes a first-stage compression-expansion machine (604), a second-stage compression-expansion machine (605), and a third-stage compression-expansion machine (606); The regenerative system (7) includes a first-stage regenerator (701), a second-stage regenerator (702), and a third-stage regenerator (703); A first-stage regenerator (701) is connected between the first-stage compression-expansion machine (604) and the second-stage compression-expansion machine (605); A second-stage regenerator (702) is connected between the second-stage compression-expansion machine (605) and the third-stage compression-expansion machine (606); A third-stage regenerator (703) is connected between the third-stage compression-expansion machine (606) and the variable-volume pressure-resistant energy storage tank (8); The water circulation pipeline (704) forms an independent cycle with the first-stage regenerator (701), the second-stage regenerator (702), and the third-stage regenerator (703) respectively.

8. A dynamic regulation method for a deep - sea energy storage device of wind power generation, characterized in that: It includes a wind power generation deep-sea energy storage device according to any one of claims 1-7 and the following method: During the low grid power supply period, the wind power generation system (1) converts the excess mechanical energy into static pressure energy through the compression-expansion cascade device (6) and stores it in the variable-volume pressure-resistant energy storage tank (8) in the form of high-pressure air; During the high grid power supply period, the variable-volume pressure-resistant energy storage tank (8) converts the stored static pressure energy of high-pressure air into additional mechanical energy through the compression-expansion cascade device (6) to drive the wind power generation system (1) to work; During the period of balanced grid power supply demand, the connection between the wind power generation system (1), the compression-expansion cascade device (6), and the variable-volume pressure-resistant energy storage tank (8) is cut off, and the compressed air energy storage and the expansion air energy release are stopped.

9. The dynamic regulation method of the deep - sea energy storage device for wind power generation according to claim 8, wherein: It also includes a data acquisition controller (9); During the low period of power grid power supply, the data acquisition controller (9) controls the sliding gear (404) to move to the working gear position b of the chute (408), connecting the first transmission gear (401) and the second transmission gear (402), including the following steps: S11. The blades (101) and the hub (102) of the wind power generation system (1) recover wind energy and convert it into mechanical energy, driving the generator drive shaft (104) to rotate forward; A part of the mechanical energy drives the generator (106) to perform the power generation task; S12. The generator drive shaft (104) rotates forward, driving the generator (106) to perform the power generation task; at the same time, the mechanical energy generated by the forward rotation of the generator drive shaft (104) is transmitted to the compression-expansion machine drive gear (601) through the generator drive gear (105), the first rack (2), the gear transmission conversion box (4) and the second rack (3), providing the power for the compression-expansion machine drive shaft (602) to rotate forward; S13. The compression-expansion machine drive shaft (602) rotates forward to drive the compression-expansion cascade device (6) to work, perform the task of compressed air energy storage, and transport the generated high-pressure air to the variable-volume pressure-resistant energy storage tank (8); During the peak period of power grid power supply, the data acquisition controller (9) controls the sliding gear (404) to move to the reverse working gear position c of the chute (408), connecting the first transmission gear (401) and the third transmission gear (403), including the following steps: S21. The high-pressure air (803) flows from the variable-volume pressure-resistant energy storage tank (8) into the compression-expansion cascade device (6), driving the compression-expansion cascade device (6) to perform the task of expanding air energy release, and at the same time driving the compression-expansion machine drive shaft (602) to rotate reversely; S22. The power of the reverse rotation of the compression-expansion machine drive shaft (602) is transmitted along the compression-expansion machine drive gear (601), the second rack (3), the gear transmission conversion box (4) and the first rack (2) to the generator drive gear (105), providing power for the generator drive shaft (104) to promote the acceleration of the rotation of the generator drive shaft (104); S23. The generator drive shaft (104) simultaneously obtains the mechanical energy converted from wind energy and the static pressure energy of compressed air, driving the generator (106) to perform the power generation task; During the period of balanced power grid power supply demand, the data acquisition controller (9) controls the sliding gear (404) to move to the neutral gear position a of the chute (408), cutting off the mechanical transmission between the first transmission gear (401) and the second transmission gear (402) and the third transmission gear (403), and stopping the compression-expansion cascade device (6) and the variable-volume pressure-resistant energy storage tank (8) from working.

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