Wind power generation gravity energy storage system based on seawater medium and working method thereof

Abstract

The invention relates to a wind power generation gravity energy storage system based on a seawater medium and a working method thereof.The system comprises a wind power generation subsystem, a gravity energy storage subsystem and a control center, and the control center is in communication connection with the wind power generation subsystem and the gravity energy storage subsystem; the control subsystem is used for correspondingly adjusting and controlling the working state of the gravity energy storage subsystem according to the wind power generation capacity of the wind power generation subsystem, and controlling the gravity energy storage subsystem to store energy when the wind power generation capacity is greater than the load demand so as to store excess electric energy; and when the wind power generation quantity is smaller than or equal to the load demand quantity, the gravity energy storage subsystem is controlled to release energy so as to compensate the wind power generation vacancy. Compared with the prior art, wind power generation and gravity energy storage are combined, the wind power generation loss can be effectively reduced, and the stability of wind power output power is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy storage technology, and in particular to a seawater-based wind power generation gravity energy storage system and a working method thereof. Background Art

[0002] With the green and low-carbon transformation of energy, new energy power generation technology has developed rapidly. Among them, wind power generation, as one of the representatives of new energy power generation, has received widespread attention and support. However, wind power generation has the characteristics of volatility, randomness and intermittency, and is prone to wind abandonment. In order to improve the utilization rate of wind energy, it is necessary to adopt a strategy of combining wind power generation with energy storage systems to effectively reduce power losses.

[0003] Energy storage technology has ushered in a broad development prospect. Among them, pumped storage is the main energy storage method, which has provided strong support for large power grids. However, the construction of pumped storage power stations requires specific geographical conditions, and the flexibility of their site selection is limited. The initial investment is high, the construction period is long, and it may cause irreversible impacts on the ecological environment; compressed air energy storage has problems such as low energy storage efficiency and immature integration technology; flywheel energy storage has disadvantages such as low energy density, high cost and high self-discharge rate; electrochemical energy storage has inherent safety issues, and its construction and operation costs are high. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a wind power generation gravity energy storage system based on seawater medium and its working method, combining wind power generation and gravity energy storage to reduce wind power generation losses and improve the stability of wind power output power.

[0005] The purpose of the present invention can be achieved through the following technical solutions: a wind power generation gravity energy storage system based on seawater medium, comprising a wind power generation subsystem, a gravity energy storage subsystem and a control center, wherein the control center is respectively connected to the wind power generation subsystem and the gravity energy storage subsystem for communication, and is used to adjust and control the working state of the gravity energy storage subsystem according to the wind power generation of the wind power generation subsystem, and when the wind power generation is greater than the load demand, the gravity energy storage subsystem is controlled to store energy to store the excess electric energy;

[0006] When the wind power generation is less than or equal to the load demand, the gravity energy storage subsystem is controlled to release energy to compensate for the shortfall in wind power generation.

[0007] Furthermore, the gravity energy storage subsystem includes a piston, a gravity tower and a water pipeline, the water pipeline is installed with a valve and a water pump turbine, the water pump turbine is connected to an electric generator, one end of the water pipeline extends below the sea level, and the other end of the water pipeline is connected to the lower end of the gravity tower, the valve and the water pump turbine are respectively connected to the control center, and the piston is arranged inside the gravity tower.

[0008] Furthermore, a distance measuring sensor is installed on the top of the gravity tower, and the distance measuring sensor is connected to the control center, and is used to measure the distance between the top of the piston and the top of the gravity tower, and transmit the measured data information to the control center.

[0009] Furthermore, sealing members are respectively installed on the top and bottom of the piston side.

[0010] Furthermore, the wind power generation subsystem includes a wind turbine nacelle and a wind turbine tower, and the gravity tower is arranged inside the wind turbine tower.

[0011] Furthermore, the height of the gravity tower is the same as that of the wind turbine tower, and there is a gap between the outer wall of the gravity tower and the inner wall of the wind turbine tower.

[0012] A working method of a wind power generation gravity energy storage system based on seawater medium comprises the following steps:

[0013] S1. Real-time acquisition of wind power generation data of the wind power generation subsystem and comparison with the preset load demand. If the wind power generation is greater than the load demand, step S2 is executed; otherwise, step S3 is executed.

[0014] S2, controlling the gravity energy storage subsystem to store the excess electric energy output by the wind power generation subsystem, and converting the electric energy into potential energy for storage;

[0015] S3. Control the gravity energy storage subsystem to release energy and convert potential energy into electrical energy to make up for the power generation shortage of the wind power generation subsystem.

[0016] Furthermore, the specific process of step S2 is as follows:

[0017] S21, determining whether the piston has reached the top position of the gravity tower, if yes, controlling the water pump turbine to stop working and closing the valve, otherwise executing step S22;

[0018] S22, control the water pump turbine to work in the water pump mode, open the valve, and the water pump turbine pumps seawater from the ocean to the lower end of the gravity tower, so that the piston moves upward, and then returns to step S21.

[0019] Furthermore, the step S21 specifically measures the distance between the piston and the top of the gravity tower. When the measured distance value is less than or equal to a preset threshold, it is determined that the piston has reached the top position of the gravity tower, otherwise it is determined that the piston has not reached the top position of the gravity tower.

[0020] Furthermore, the specific process of step S3 is as follows:

[0021] The water pump turbine is controlled to work in the water turbine mode, the valve is opened, the piston moves downward to convert the potential energy into mechanical energy, and the coaxial rotation drives the electric generator to operate and output electrical energy.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] The present invention connects the control center to the wind power generation subsystem and the gravity energy storage subsystem in communication. When the wind power generation is greater than the load demand, the gravity energy storage subsystem is controlled to store energy to store the excess electric energy; when the wind power generation is less than or equal to the load demand, the gravity energy storage subsystem is controlled to release energy to compensate for the shortfall in wind power generation. This can achieve the storage of excess electric energy of wind power generation, reduce wind power generation losses, and improve the power supply stability of the wind power generation system.

[0024] The present invention adopts a piston-type gravity energy storage method. When the wind power generation is higher than the load demand, the control valve is opened, and the electric generator drives the water pump turbine to operate, so that it works in the water pump mode, and the seawater is pumped to the lower end of the gravity tower to realize the vertical lifting of the piston, converting the excess electric energy into the potential energy of the piston, and storing the excess electric energy in the form of gravity potential energy; when the wind power generation is lower than the load demand, the control valve is opened to make the water pump turbine work in the turbine mode, and the piston moves downward under the action of gravity, forcing the seawater to be re-injected into the ocean through the water pipeline, and the turbine converts the gravity potential energy released when the piston descends into mechanical energy, and converts the mechanical energy into electrical energy through the turbine and the electric generator to compensate for the shortage of wind power generation and meet the load power demand. In this way, the piston-type gravity energy storage system is constructed by taking advantage of the height of the wind turbine tower, and the storage and release of electrical energy can be reliably realized while ensuring the normal operation of the existing wind turbine.

[0025] The present invention installs a distance measuring sensor on the top of the gravity tower to measure the distance between the top of the piston and the top of the gravity tower to determine whether the piston reaches the top position of the gravity tower, and then decides whether to open the valve and stop the water pump turbine. It can combine the wind power generation and the gravity energy storage capacity to perform corresponding control to ensure the stability of the system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0027] Figure 2 It is a schematic diagram of the working principle of the present invention;

[0028] Figure 3 It is a schematic diagram of the working method of the present invention;

[0029] Figure 4 It is a schematic diagram of the application process of the embodiment;

[0030] Figure 5 A schematic diagram showing the comparison between wind power generation and load demand in the embodiment;

[0031] Explanation of the marks in the figure: 1. Fan nacelle, 2. Distance sensor, 3. Piston, 4. Gravity tower, 5. Seal, 6. Fan tower, 7. Water pipeline, 8. Electric generator, 9. Water pump turbine, 10. Valve, 11. Control center. DETAILED DESCRIPTION

[0032] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Example

[0034] A wind power generation gravity energy storage system based on seawater medium, comprising a wind power generation subsystem, a gravity energy storage subsystem and a control center 11, wherein the control center 11 is respectively connected to the wind power generation subsystem and the gravity energy storage subsystem for communication, and is used to adjust and control the working state of the gravity energy storage subsystem according to the wind power generation of the wind power generation subsystem, and when the wind power generation is greater than the load demand, the gravity energy storage subsystem is controlled to store energy to store the excess electric energy;

[0035] When the wind power generation is less than or equal to the load demand, the gravity energy storage subsystem is controlled to release energy to compensate for the shortfall in wind power generation.

[0036] like Figure 1As shown, the above system specifically includes a wind turbine cabin 1, a distance sensor 2, a piston 3, a gravity tower 4, a seal 5, a wind turbine tower 6, a water pipeline 7, an electric generator 8, a water pump turbine 9, a valve 10 and a control center 11. Among them, the piston 3 is located inside the gravity tower 4, dividing the internal space of the gravity tower 4 into an upper cabin and a lower cabin, and the seal 5 is a circular sealing ring, which is respectively installed on the top and bottom of the side of the piston 3. The end of the water pipeline 7 is located at a certain distance below the sea level to connect the ocean with the lower cabin of the gravity tower 4. The gravity tower 4 is located inside the wind turbine tower 6, and the two have the same height. There is a certain gap between the outer wall of the gravity tower 4 and the inner wall of the wind turbine tower 6. The wind turbine tower 6 and the gravity tower 4 are provided with circular openings on the cylinder walls near the bottom, and the ocean is connected to the lower cabin of the gravity tower 4 through the water pipeline 7. A distance measuring sensor 2 is also installed on the top of the gravity tower 4 , and its distance measuring value is the distance between the top of the piston 3 and the top of the gravity tower 4 .

[0037] The working principle of this scheme is as follows Figure 2 As shown, in the case of excess wind power generation, the pump turbine 9 works in the water pump mode, converting the excess electrical energy into the potential energy of the piston 3 in the water storage medium to achieve energy storage. If the wind power generation power is not enough to meet the demand, the pump turbine 9 can be started to work in the turbine mode. In this mode, the pump turbine 9 converts the potential energy of the piston 3 into mechanical energy, and drives the electric generator 8 to operate with the coaxial rotation, completing the energy conversion process from potential energy to electrical energy.

[0038] Specifically, when the wind power generation is higher than the load power demand, the control center 11 sends a control signal to the pump turbine 9 and the valve 10, and the pump turbine 9 works in the pump mode and opens the valve 10. In this mode, the pump turbine 9 pumps seawater from the ocean to the lower cabin of the gravity tower to achieve the storage of excess energy from wind power generation. If the ranging value is less than or equal to the set value, the pump turbine 9 stops working and the valve 10 is closed.

[0039] When the wind power generation exceeds the load demand, further judgment is designed. When the distance value output by the distance sensor 2 is less than or equal to a certain set threshold, the control valve 10 is closed and the water pump turbine 9 stops working.

[0040] When the wind power generation is lower than the load power demand, the control center 11 sends instructions to the pump turbine 9 and the valve 10, the pump turbine 9 works in the turbine mode, and the valve 10 opens. In this mode, the piston 3 descends under the influence of gravity, thereby driving the seawater in the lower cabin of the gravity tower to flow through the water pipeline 7 and re-inject into the ocean. The pump turbine 9 rotates driven by the seawater, thereby driving the electric generator 8 to generate electrical energy.

[0041] The working process of the above system is as follows Figure 3 As shown, the following steps are included:

[0042] S1. Real-time acquisition of wind power generation data of the wind power generation subsystem and comparison with the preset load demand. If the wind power generation is greater than the load demand, step S2 is executed; otherwise, step S3 is executed.

[0043] S2, controlling the gravity energy storage subsystem to store the excess electric energy output by the wind power generation subsystem, and converting the electric energy into potential energy for storage;

[0044] S3. Control the gravity energy storage subsystem to release energy and convert potential energy into electrical energy to make up for the power generation shortage of the wind power generation subsystem.

[0045] This embodiment applies the above solution, such as Figure 4 As shown, the system monitors the wind speed and piston position in real time, and calculates the wind power generation and gravity energy storage capacity (for the gravity energy storage system, when the piston 3 is located at the bottom of the gravity tower 4, the system energy storage capacity is 0, that is, SOC is equal to 0; when the piston 3 reaches the top of the gravity tower 4, the system is at full capacity, that is, SOC is equal to 1). When the wind power generation exceeds the load demand, the system first determines whether the piston 3 reaches the top position of the gravity tower 4. Specifically, when the ranging value is less than or equal to the set value, the pump turbine 9 stops working and the valve 10 is closed; otherwise, the pump turbine 9 works in the water pump mode and the valve 10 is opened. When the wind power generation is lower than the load demand, the pump turbine 9 works in the turbine mode, and the system opens the valve 10 to release the gravity energy storage to make up for the energy gap.

[0046] The schematic diagram of wind power generation and load demand is as follows: Figure 5 As shown, when the wind power generation is higher than the load demand, the gravity energy storage subsystem is charged to absorb the excess wind power generation; when the wind power generation cannot meet the load demand, the gravity energy storage subsystem is discharged to make up for the shortage of wind power generation.

[0047] In summary, this scheme is designed so that when there is sufficient wind power generation, the pump turbine operates in pump mode, pumping seawater to the lower cabin of the gravity energy storage tower, realizing vertical lifting of the piston, and converting electrical energy into gravitational potential energy for storage; when there is insufficient wind power generation, the seawater drives the pump turbine to operate in turbine mode by using the piston's own gravity to descend in the tower, thereby driving the electric generator to generate electricity and realizing the conversion of gravitational potential energy into electrical energy. The piston is used to move vertically up and down in the upright cylindrical gravity tower to achieve energy storage and release, which can make full use of seawater and wind resources, realize wind power generation electrical energy storage, and improve the power supply stability of the wind power generation system.

Claims

1. A wind power generation gravity energy storage system based on seawater medium, characterized in that: The invention comprises a wind power generation subsystem, a gravity energy storage subsystem and a control center (11). The control center (11) is respectively connected to the wind power generation subsystem and the gravity energy storage subsystem for communication and is used to adjust and control the working state of the gravity energy storage subsystem according to the wind power generation of the wind power generation subsystem. When the wind power generation is greater than the load demand, the gravity energy storage subsystem is controlled to store energy to store the excess electric energy. When the wind power generation is less than or equal to the load demand, the gravity energy storage subsystem is controlled to release energy to compensate for the shortfall in wind power generation.

2. A seawater-based wind power generation gravity energy storage system according to claim 1, characterized in that: The gravity energy storage subsystem comprises a piston (3), a gravity tower (4) and a water pipeline (7); a valve (10) and a water pump turbine (9) are installed on the water pipeline (7); the water pump turbine (9) is connected to an electric generator (8); one end of the water pipeline (7) extends below the sea level; the other end of the water pipeline (7) is connected to the lower end of the gravity tower (4); the valve (10) and the water pump turbine (9) are respectively connected to a control center (11); and the piston (3) is arranged inside the gravity tower (4).

3. A seawater-based wind power generation gravity energy storage system according to claim 2, characterized in that: A distance measuring sensor (2) is installed on the top of the gravity tower (4), and the distance measuring sensor (2) is connected to the control center (11) and is used to measure the distance between the top of the piston (3) and the top of the gravity tower (4), and transmit the measured data information to the control center (11).

4. A seawater-based wind power generation gravity energy storage system according to claim 2, characterized in that: Seals (5) are respectively installed on the top and bottom of the side of the piston (3).

5. A seawater-based wind power generation gravity energy storage system according to claim 2, characterized in that: The wind power generation subsystem comprises a wind turbine cabin (1) and a wind turbine tower (6), wherein the gravity tower (4) is arranged inside the wind turbine tower (6).

6. A seawater-based wind power generation gravity energy storage system according to claim 5, characterized in that: The height of the gravity tower (4) is the same as the height of the wind turbine tower (6), and there is a gap between the outer wall of the gravity tower (4) and the inner wall of the wind turbine tower (6).

7. A working method of a wind power generation gravity energy storage system based on seawater medium, applied to a wind power generation gravity energy storage system based on seawater medium as claimed in claim 2, characterized in that: The following steps are involved: S1. Real-time acquisition of wind power generation data of the wind power generation subsystem and comparison with the preset load demand. If the wind power generation is greater than the load demand, step S2 is executed; otherwise, step S3 is executed. S2, controlling the gravity energy storage subsystem to store the excess electric energy output by the wind power generation subsystem, and converting the electric energy into potential energy for storage; S3. Control the gravity energy storage subsystem to release energy and convert potential energy into electrical energy to make up for the power generation shortage of the wind power generation subsystem.

8. The working method of a seawater-based wind power gravity energy storage system according to claim 7, characterized in that: The specific process of step S2 is: S21, determining whether the piston has reached the top position of the gravity tower, if yes, controlling the water pump turbine to stop working and closing the valve, otherwise executing step S22; S22, control the water pump turbine to work in the water pump mode, open the valve, and the water pump turbine pumps seawater from the ocean to the lower end of the gravity tower, so that the piston moves upward, and then returns to step S21.

9. The working method of a seawater-based wind power generation gravity energy storage system according to claim 8, characterized in that: The step S21 specifically measures the distance between the piston and the top of the gravity tower. When the measured distance value is less than or equal to a preset threshold, it is determined that the piston has reached the top of the gravity tower. Otherwise, it is determined that the piston has not reached the top of the gravity tower.

10. The working method of a seawater-based wind power generation gravity energy storage system according to claim 7, characterized in that: The specific process of step S3 is: The water pump turbine is controlled to work in the water turbine mode, the valve is opened, the piston moves downward to convert the potential energy into mechanical energy, and the coaxial rotation drives the electric generator to operate and output electrical energy.

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