A tower type gravity energy storage system based on supermassive weight blocks

Abstract

The application discloses a tower type gravity energy storage system based on a supermassive weight block, which comprises the supermassive weight block, a weight lifting system matched with the supermassive weight block, a braking system and a control system. By using the supermassive weight block and combining the transformation of the weight lifting system, the braking system and the control system, the tower type gravity energy storage system does not need to be arranged with a weight horizontal transfer system, can effectively utilize the height of the gravity energy storage tower, reduces the energy loss during the weight horizontal transfer, does not need a weight lifting cabin and a cabin idle stroke driving motor, saves the energy loss during the cabin idle stroke operation, reduces the number of motor equipment of the tower type gravity energy storage system, reduces the system complexity and investment cost, improves the system reliability, and increases the comprehensive efficiency of the gravity energy storage system.

Description

Technical Field

[0001] This invention belongs to the field of gravity energy storage technology, specifically relating to a tower-type gravity energy storage system based on an ultra-large mass block. Background Technology

[0002] Existing gravity energy storage technologies include tower gravity energy storage systems, inclined plane gravity energy storage systems, ocean-based gravity energy storage systems, mine-based gravity energy storage systems, and linear motor gravity energy storage systems. Among these, tower gravity energy storage systems are the most mature gravity energy storage technology, and several tower gravity energy storage systems have been built worldwide, with installed capacities ranging from 5MWh to 100MWh.

[0003] However, existing tower-type gravity energy storage technology has three main drawbacks: First, the horizontal movement and acceleration / deceleration of the load consume its kinetic energy, reducing the efficiency of the energy storage system. Second, the load is loaded and lowered by a car, and the empty return stroke after the car has transported the load requires an auxiliary motor for traction, consuming energy. Third, after the car is raised to a designated height, the load needs to be transferred from the car to a horizontally transporting hydraulic trolley, requiring a complex transfer mechanism and control system, increasing system complexity and reducing system reliability. With the increasing demand for tower-type gravity energy storage, there is an urgent need to propose a new gravity energy storage solution to address these problems, thereby accelerating the promotion and application of gravity energy storage. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a tower-type gravity energy storage system based on an ultra-large mass block, realizing a gravity energy storage system that does not require horizontal transport of heavy objects, reducing system complexity, improving system reliability, and increasing the overall efficiency of the gravity energy storage system.

[0005] This invention is achieved through the following technical solution:

[0006] A tower-type gravity energy storage system based on an ultra-large mass block includes an ultra-large mass block, a lifting system for the heavy object, a braking system, and a control system.

[0007] The ultra-massive heavy block is used to convert electrical energy downloaded from the grid into gravitational potential energy for storage, or to convert stored gravitational potential energy into electrical energy and upload it to the grid. It is the final carrier of energy in the energy storage system. The ultra-massive heavy block has a mass of over 200 tons.

[0008] The heavy object lifting system is used to lift a super-massive heavy object from the bottom to the top of the gravity energy storage tower during energy storage, and to lower the super-massive heavy object from the top to the bottom of the gravity energy storage tower during power generation.

[0009] The braking system is used to brake the energy storage system when it stops operating, thereby limiting the vertical displacement of the massive heavy object and ensuring that the massive heavy object does not fall out of control.

[0010] The control system is used to control the power generation and energy storage operation status of the gravity energy storage system, monitor the running speed of the ultra-large mass block, and control the braking system to operate in the event of an accident.

[0011] A further improvement of the present invention is that the vertical height of the super-massive heavy object is more than three times its horizontal cross-sectional length and width or more than 15 meters. The top of the super-massive heavy object is equipped with 3 to 6 movable pulley groups, each of which contains multiple movable pulleys. The top of the side of the super-massive heavy object is equipped with an upper guide shoe, and a lower guide shoe is installed near the bottom. A brake safety caliper is installed in the middle part of the side.

[0012] A further improvement of the present invention is that both the upper and lower guide shoes use rolling guide shoes to control the directional deviation during the lifting and lowering of the ultra-large mass block.

[0013] A further improvement of the present invention is that the heavy lifting system is arranged at the top of the gravity energy storage tower, including an electric generator, a main shaft and a secondary shaft, and the gravity energy storage tower is supported by multiple load-bearing columns.

[0014] Each electric generator is equipped with one main shaft and multiple secondary shafts. Each secondary shaft is used to drive a series of energy storage towers. The main shaft and secondary shafts transmit power through transmission gears, which are constantly meshed. The clutch and high-elasticity coupling on the secondary shaft are used to control whether each series of energy storage towers participates in energy storage and release. The control system is used to monitor the rotational speed of the secondary shaft.

[0015] A further improvement of the present invention is that the heavy object lifting system uses 3 to 6 steel cables to lift or lower an ultra-large mass block, and the lifting speed of the heavy object is no more than 0.08 m / s.

[0016] A further improvement of the present invention is that each energy storage tower group contains no more than 5 gravity energy storage towers.

[0017] A further improvement of the present invention is that, during energy storage and power generation, multiple heavy objects in each energy storage tower group are simultaneously lifted and lowered, and multiple energy storage tower groups driven by the secondary shaft are directly connected to the main shaft. The acceleration impact force is buffered by the clutch and the elastic device on the high-elasticity clutch or the ultra-large mass block.

[0018] A further improvement of the present invention is that the braking system includes a braking device mounted on the countershaft and a braking safety caliper on the oversized heavy object block.

[0019] A further improvement of the present invention is that, during normal operation, the braking device is activated to provide braking torque to stop the secondary shaft from rotating; in the event of an accident, the safety brake is activated to decelerate the oversized heavy object and reduce the impact of the oversized heavy object on the gravity energy storage tower.

[0020] A further improvement of the present invention is that when the brake safety clamp is activated, the energy storage unit is shut down for maintenance.

[0021] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0022] This invention proposes a tower-type gravity energy storage system based on ultra-large mass heavy blocks. By using ultra-large mass heavy blocks and modifying the lifting, braking, and control systems, the tower-type gravity energy storage system eliminates the need for a horizontal transfer system, reducing energy loss during horizontal transfer. It also eliminates the need for a lifting car and a drive motor for the car's idle stroke, saving energy loss during idle stroke operation. This reduces the number of motors in the tower-type gravity energy storage system, lowers system complexity and investment costs, improves system reliability, and increases the overall efficiency of the gravity energy storage system.

[0023] Furthermore, in this invention, the mass of the ultra-large mass block far exceeds the typical mass of the mass blocks in existing gravity energy storage units. The mass of the mass blocks in existing gravity energy storage units generally does not exceed 25 tons, while the ultra-large mass block in this invention is at least 200 tons, with a typical mass of 1000 tons. The vertical height of the ultra-large mass block is more than three times its horizontal cross-sectional length and width, or exceeds 15 meters, with 20 to 24 meters being optimal. The height of the ultra-large mass block in this invention is more than five times the height of the standard mass block in existing tower-type gravity energy storage systems, equivalent to having more than five layers of standard mass blocks in a single gravity energy storage tower, thus eliminating the need for stacking the ultra-large mass block. Through this improvement, the gravity energy storage system, while ensuring effective utilization of the gravity energy storage tower height, eliminates the need for a horizontal mass transfer system, solving the problems of energy consumption and system complexity associated with horizontal transfer in current tower-type gravity energy storage systems.

[0024] Furthermore, to address the issue of excessive tension in the steel cables caused by the massive weight blocks, 3 to 6 movable pulley sets are installed on the top of the massive weight blocks. Each movable pulley set is paired with a stationary pulley set at the top of the tower to lift the massive weight blocks. Each movable pulley set contains multiple movable pulleys, which greatly reduces the tension on the steel cables lifting the massive weight blocks. Moreover, by reserving a certain margin, the weight blocks will not fall out of control if one or two steel cables breaking while lifting a single massive weight block break.

[0025] Furthermore, an upper guide shoe is installed on the top side of the super-massive block, and a lower guide shoe is installed near the bottom. Both the upper and lower guide shoes are rolling guide shoes. A brake safety clamp is installed in the middle of the side. The upper and lower guide shoes prevent the super-massive block from colliding with the energy storage tower well wall when it is raised and lowered. The brake safety clamp is used to decelerate the super-massive block in case of an accident, reducing the impact of the super-massive block on the gravity energy storage tower.

[0026] Furthermore, in the heavy-duty lifting system, the electric generator and its associated main and auxiliary shafts are arranged at the top of the gravity energy storage tower. Based on the force analysis of the moving pulleys, this top arrangement can further reduce the tension on the steel cables lifting the ultra-large mass block. Simultaneously, the top arrangement simplifies the traditional main and auxiliary shaft system, improving the reliability of the gravity energy storage system. Through the top arrangement, the use of multiple steel cables, and the combination of moving and stationary pulleys, the tension of a single steel cable can generally be reduced to less than 1 / 30 of the weight of the ultra-large mass block, lowering the extremely high requirements for cable strength in tower-type gravity energy storage systems based on ultra-large mass blocks.

[0027] Furthermore, the heavy-duty lifting system uses 3-6 steel cables to raise or lower the ultra-large mass block, with a lifting speed not exceeding 0.08 m / s. This extremely low lifting speed improves the system's stability and reduces the impact on the gravity energy storage tower during the acceleration and deceleration of the ultra-large mass block. If the typical lifting speed of existing tower-type gravity energy storage is 2 m / s, the distance required for the braking system to stop the heavy object is too long, posing a significant safety risk. In addition, because of the large mass of the ultra-large mass block, the speed transmitted to the electric generator side can be maintained at a relatively high value through the gearbox, and the main shaft and auxiliary shaft will not bear excessive torque.

[0028] Furthermore, each electric generator is equipped with one main shaft and multiple secondary shafts. Each secondary shaft drives a row of energy storage towers. A single energy storage tower group is driven by one secondary shaft. Each energy storage tower group contains no more than 5 gravity energy storage towers. If the number of energy storage towers in each row is too large, the torque on the secondary bearing will be large, and the braking device on the secondary shaft will be unable to provide sufficient braking torque.

[0029] Furthermore, the main shaft and the secondary shaft transmit power through transmission gears, which are engaged for a long time. The clutch and high-elasticity coupling on the secondary shaft control whether each energy storage tower group participates in energy storage and release. During energy storage and power generation, multiple loads in each energy storage tower group are raised and lowered simultaneously. By arranging the clutch and high-elasticity coupling after the transmission gear, the number of clutches and high-elasticity couplings can be reduced, thereby reducing the system investment cost. The trade-off is that there is a certain power step during the energy storage and power generation process, but this power step can be easily eliminated by using small-capacity supercapacitors or electrochemical energy storage.

[0030] Furthermore, during the switching between energy storage and power generation, multiple energy storage tower groups driven by the secondary shaft are directly connected to the main shaft. The acceleration impact force is buffered by the clutch and the high-elasticity clutch or the elastic device on the ultra-large mass block. Since the operating speed of the ultra-large mass block in this invention is extremely low, not exceeding 0.08 m / s, there is no need to consider a special acceleration / deceleration system and control logic. By buffering the acceleration impact force through the clutch and the high-elasticity clutch or the elastic device on the ultra-large mass block, the requirements can be met, and the acceleration / deceleration time and distance are greatly reduced. This further utilizes the effective lifting height of the gravity energy storage tower and increases the overall energy conversion efficiency of the energy storage system. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a tower-type gravity energy storage system based on an ultra-large mass block, as described in this invention.

[0032] Figure 2 This is an isometric drawing of a tower-type gravity energy storage system based on an ultra-large mass block, as described in this invention.

[0033] Figure 3 This is a schematic diagram of a heavy block in a tower gravity energy storage system based on an ultra-large mass heavy block, as described in this invention.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. Load-bearing column; 2. Countershaft; 3. Braking device; 4. Clutch and high-elasticity coupling; 5. Transmission gear; 6. Fixed pulley block; 7. Energy storage tower assembly; 8. Electric generator; 9. Main shaft; 10. Gravity energy storage tower; 11. Moving pulley block; 12. Load-bearing ground; 13. Oversized heavy object block; 14. Upper guide shoe; 15. Brake safety caliper; 16. Lower guide shoe. Detailed Implementation

[0036] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0037] This invention provides a tower-type gravity energy storage system based on an ultra-large mass block, such as... Figure 1 The image shown is a top view of the smallest unit module of the gravity energy storage system. The smallest unit module includes a massive heavy block 13 and its associated lifting, braking, and control systems. In this scheme, a total of 10 such units are constructed. Figure 1The gravity energy storage minimum unit module is shown. Each minimum unit module is equipped with one electric generator 8, which can operate as both a motor and a generator when storing energy and generating electricity. The power of the electric generator 8 is 5.0MW when generating electricity and 5.8MW when storing energy. The energy storage capacity of a single minimum unit module is 20MWh, and the total installed capacity of the energy storage power station is 50MW / 200MWh.

[0038] from Figure 2 As can be seen, the super-mass heavy block of this invention is positioned within the well wall of the gravity energy storage tower. When the energy of the gravity energy storage system is fully released, the super-mass heavy block is located on the load-bearing ground 12 of the gravity energy storage tower. During energy storage and power generation, the super-mass heavy block can be vertically raised and lowered along the well wall of the gravity energy storage tower. The mass of the super-mass heavy block reaches over 200 tons, generally reaching 1000 tons. The vertical height of the super-mass heavy block 13 is more than three times its horizontal cross-sectional length and width, or exceeds 15 meters, exceeding the height of more than five stories of existing gravity energy storage towers. In this design, the super-mass heavy block 13 weighs 768 tons, with a length, width, and height of 4 meters, 4 meters, and 20 meters, respectively. A single heavy object is lifted by four steel cables, each cable passing through four pairs of moving and stationary pulleys. The fixed pulley group 6 is located at the top of the gravity storage tower, and the moving pulley group 11 is installed on top of the massive heavy object 13. The electric generator 8, main shaft 9, and auxiliary shaft 2 are all installed at the top of the gravity storage tower 10. This arrangement ensures that the tension borne by a single steel cable is 1 / 36 of the total weight of the single heavy object, approximately 210,000 Newtons. With a margin of 2 times, a steel cable with a diameter of 24 mm is selected. The gravity storage tower 10 is supported by multiple load-bearing columns 1.

[0039] Figure 3 A structural schematic diagram of the massive heavy object 13 is provided. Two rolling upper guide shoes 13 are installed on each of the upper two sides of the massive heavy object 13, and two rolling lower guide shoes 16 are installed on each of the lower two sides. During normal operation, the guide shoes are in contact with the guide rails installed on the well wall of the gravity energy storage tower 10, ensuring that the movement direction of the massive heavy object 13 does not deviate. Two braking safety clamps 15 are installed at the middle positions on both sides of the massive heavy object 13.

[0040] In this design, four massive weight blocks 13 are connected to a single secondary shaft 2. The secondary shaft 2 drives 16 cable reels. As the reels rotate, they pull steel cables, thus raising or lowering the massive weight blocks 13. Each cable reel has a diameter of 0.5 meters, a width of 2 meters, and a rotation speed of 6 revolutions per minute. Each reel can withstand a torque of 100,000 Newton-meters, and the lifting speed of the weight is 0.04 meters per second. Four braking devices 3 are installed on the secondary shaft 2. These are Wichita hydraulic brakes, each providing a braking torque exceeding 100,000 Newton-meters. The secondary shaft 2 rotates at 25 revolutions per minute and has a diameter of 40 centimeters.

[0041] In this invention, the main shaft 9 and the secondary shaft 2 transmit power through a transmission gear 5, which remains engaged continuously. In this design, the main shaft 9 and the secondary shaft 2 are driven by a curved bevel gear. One main shaft 9 can simultaneously drive four secondary shafts 2, or drive 16 secondary shafts 2 in a time-sharing manner. The transmission power of a single curved bevel gear does not exceed 1.5MW. A clutch and a highly flexible coupling 4 are installed at the end of the secondary shaft 2 closest to the main shaft 9. During energy storage system operation, the curved bevel gear remains engaged continuously, and the clutch controls whether the weight on the secondary shaft 2 participates in energy storage and power generation.

[0042] Each secondary shaft 2 drives one energy storage tower group 7. The main shaft 9 and secondary shaft 2 transmit power through a transmission gear 5, which is constantly engaged. The clutch and high-elasticity coupling 4 on the secondary shaft 2 are used to control whether each energy storage tower group 7 participates in energy storage and release. The control system is used to monitor the rotational speed of the secondary shaft 2. Each energy storage tower group 7 contains no more than 5 gravity energy storage towers 10.

[0043] In the braking system, when the gravity energy storage system is operating normally, if it is necessary to stop the movement of the heavy object, the control system issues an action command, and the hydraulic brake installed on the secondary shaft 2 actuates, causing the secondary shaft 2 to stop rotating, and the system stops normally. When one or two steel cables on a single heavy object break, because the tension of the steel cables retains more than twice the margin, the remaining two steel cables can still withstand the weight of the oversized heavy object 13, ensuring that the oversized heavy object 13 does not fall out of control. If more than two steel cables break, or the gravity energy storage system is in a similar accident state, when the heavy object falls out of control, the falling speed of the heavy object exceeds the limit, thereby triggering the safety clamps installed on both sides of the heavy object to act. The friction between the heavy object and the guide rail slows down the heavy object and eventually stops it. This type of accident state is an extreme working condition, and after it occurs, the machine must be shut down for maintenance before it can be put back into operation.

[0044] The above description is merely a specific embodiment of the present invention and does not limit the patent scope of the present invention. All gravity energy storage systems composed of equivalent structures based on the contents of the present invention specification and drawings are similarly included within the patent protection scope of the present invention.

Claims

1. A tower-type gravity energy storage system based on an ultra-large mass block, characterized in that, Includes an extra-large mass block (13), a heavy lifting system, a braking system, and a control system; The super-mass heavy block (13) is used to convert the electrical energy downloaded from the grid into gravitational potential energy for storage, or to convert the stored gravitational potential energy into electrical energy and upload it to the grid. It is the final carrier of energy in the energy storage system. The super-mass heavy block has a mass of 200-1000 tons. The heavy lifting system is used to lift the super-massive heavy block (13) from the bottom of the gravity energy storage tower (10) to the top of the gravity energy storage tower (10) during energy storage, and to lower the super-massive heavy block (13) from the top of the gravity energy storage tower (10) to the bottom of the gravity energy storage tower (10) during power generation. The braking system is used to brake the energy storage system when it stops running to limit the vertical displacement of the super-massive block (13) and ensure that the super-massive block (13) does not fall out of control. The control system is used to control the power generation and energy storage operation status of the gravity energy storage system, monitor the running speed of the super-massive heavy block (13), and control the braking system to operate in case of an accident. The vertical height of the super-mass heavy block (13) is more than 3 times its horizontal cross-sectional length and width or more than 15 meters. The top of the super-mass heavy block (13) is equipped with 3 to 6 movable pulley groups (11), each movable pulley group (11) contains multiple movable pulleys. The top of the side of the super-mass heavy block (13) is equipped with an upper guide shoe (14), and a lower guide shoe (16) is installed near the bottom. A brake safety caliper (15) is installed in the middle of the side. The heavy lifting system is arranged on the top of the gravity energy storage tower (10), including an electric generator (8), a main shaft (9) and a secondary shaft (2). The gravity energy storage tower (10) is supported by multiple load-bearing columns (1). Each electric generator (8) is equipped with one main shaft (9) and multiple secondary shafts (2). Each secondary shaft (2) is used to drive a row of energy storage towers (7). The main shaft (9) and the secondary shaft (2) transmit power through a transmission gear (5), and the transmission gear (5) is meshed for a long time. The clutch and high-elasticity coupling (4) on the secondary shaft (2) are used to control whether each row of energy storage towers (7) participates in energy storage and release. The control system is used to monitor the rotational speed of the secondary shaft (2). During energy storage and power generation, multiple heavy objects in each energy storage tower group (7) are lifted and lowered simultaneously. The multiple energy storage tower groups (7) driven by the secondary shaft (2) are directly connected to the main shaft (9). The acceleration impact force is buffered by the clutch and the elastic device on the high elastic coupling (4) or the super-mass heavy object block (13). The braking system includes a brake device (3) mounted on the subshaft (2) and a brake safety caliper (15) on the oversized mass block (13).

2. The tower-type gravity energy storage system based on an ultra-large mass block according to claim 1, characterized in that, Both the upper guide shoe (14) and the lower guide shoe (16) use rolling guide shoes to control the directional deviation of the super-massive heavy block (13) during the lifting and lowering process.

3. A tower-type gravity energy storage system based on an ultra-large mass block according to claim 1, characterized in that, The heavy object lifting system uses 3 to 6 steel cables to lift or lower an oversized heavy object (13), and the lifting speed of the heavy object is no more than 0.08 m / s.

4. A tower-type gravity energy storage system based on an ultra-large mass block according to claim 1, characterized in that, Each energy storage tower group (7) contains no more than 5 gravity energy storage towers (10).

5. A tower-type gravity energy storage system based on an ultra-large mass block according to claim 1, characterized in that, During normal operation, the braking device (3) is activated to provide braking torque to stop the rotation of the sub-shaft (2). In case of an accident, the brake safety clamp (15) is activated to decelerate the oversized heavy block (13) and reduce the impact of the oversized heavy block (13) on the gravity energy storage tower (10).

6. A tower-type gravity energy storage system based on an ultra-large mass block according to claim 5, characterized in that, When the brake safety caliper (15) is activated, the energy storage unit is shut down for maintenance.

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