A dual-liquid vibration damping liquid tank for wind turbine towers designed for source-grid-load-storage synergy

Abstract

A dual-liquid vibration damping sloshing chamber for wind turbine towers, oriented towards source-grid-load-storage synergy, belongs to the technical field of wind turbine vibration damping equipment. It is a sloshing damping structure externally mounted on the wind turbine body, including a wind vane, a sloshing chamber structure consisting of an annular sloshing chamber, liquid baffles, upper liquid, and lower liquid, and a turntable fixing structure consisting of a rotor and rotor flange. The annular sloshing chamber has a central through hole, is fitted onto the tower, contains liquid baffles, and is filled with two immiscible liquids with different densities. The wind vane is arranged outside the annular sloshing chamber. The sloshing damping structure is fixed to a fixed section of the wind turbine tower via the rotor flange. This invention improves the vibration damping effect of the sloshing damping structure by replacing a single sloshing liquid with a stable, layered, immiscible dual liquid, accurately adapting to all operating conditions. Through the linkage of the wind vane and liquid baffles, the vibration damping efficiency of the sloshing damping structure is improved, the generation of resonance effects is suppressed, and the stability of the vibration damping effect of the sloshing damping structure is enhanced.

Description

Technical Field

[0001] This invention belongs to the technical field of wind turbine vibration reduction equipment, and relates to a dual-liquid vibration reduction sloshing tank for wind turbine towers oriented towards source-grid-load-storage synergy. Background Technology

[0002] Wind power generation is an important component of current new energy power generation. As the core structure supporting the wind turbine and nacelle, the wind turbine tower is subjected to wind loads and the vibration of the equipment itself for a long time, which easily generates low-frequency large-amplitude vibrations. This exacerbates fatigue damage to the tower structure, shortens its service life, and in severe cases, can even lead to tower collapse and various safety accidents.

[0003] Currently, common vibration reduction methods for wind turbine towers include mechanical dampers, tuned mass dampers, and sloshing dampers. Mechanical dampers rely on the synergistic effect of elastic elements and damping materials; tuned mass dampers counteract tower vibrations through the resonance effect of an added mass; and sloshing dampers dissipate vibration energy through the viscous and inertial forces generated by liquid sloshing. However, all of these methods suffer from poor adaptability to complex operating conditions and a tendency for their effectiveness to diminish over long-term use. For example, a floating offshore wind turbine based on a tuned mass damper, as described in Chinese invention patent (application number: 202411548841.6), achieves rapid vibration reduction through the passive sloshing of the mass. However, after long-term use, this leads to creep in the steel cables suspending the mass, and the damping performance of other damping elements also deteriorates with the length of the application cycle, resulting in a weakened vibration reduction effect and high maintenance costs. Meanwhile, it has poor adaptability to vibration frequencies, especially in complex multi-directional wind fields and turbulent environments. The arrangement of mechanical damping elements limits its ability to achieve optimal vibration reduction in a limited set of directions. Therefore, when wind speed or direction changes, the vibration reduction efficiency will decrease to some extent. Furthermore, a free-surface reinforced sloshing liquid damper for floating wind turbines, as provided in Chinese Utility Model Patent (Application No.: 202421123852.5), uses a single liquid as the damping medium, achieving vibration reduction through liquid sloshing. However, the density, viscosity, and other physical parameters of a single liquid are fixed, resulting in a limited range for adjusting its damping characteristics. The free surface of the single liquid is easily broken during liquid sloshing, increasing energy dissipation and affecting the expected vibration reduction of the damping device. Additionally, using a motor to rotate the sloshing liquid damper to control the vibration direction of the wind turbine results in high power supply costs.

[0004] In summary, there is an urgent need for a new type of wind turbine tower vibration damping device that can adapt to complex wind field environments, has stable and easily adjustable vibration reduction performance, and is low in maintenance and energy consumption, so as to ensure the safe and stable operation of the wind turbine tower structure during its service life, extend its service life, and reduce the operational burden. Summary of the Invention

[0005] To address the issues of insufficient damping characteristics of a single liquid and energy dissipation caused by sloshing and breakage, an immiscible two-liquid stratified structure is a viable solution. Utilizing the density difference between two immiscible liquids to form a stable stratification interface, the damping parameters can be adjusted by regulating the ratio of the two liquids to suit different vibration frequency requirements. Simultaneously, the two-liquid sloshing chamber effectively prevents breakage of the free liquid surface during sloshing, reducing energy dissipation and enhancing vibration reduction. Arranging a wind vane on the outer side allows the sloshing damper to rotate autonomously under complex wind loads, effectively reducing operating costs. Dividing the sloshing chamber into multiple compartments with partitions effectively prevents the liquid from forming a ring flow due to vibration excitation within the chamber, reducing resonance effects and thus preventing a weakening of vibration reduction performance. Therefore, this invention proposes a two-liquid vibration-damping sloshing chamber for wind turbine towers oriented towards source-grid-load-storage synergy. It optimizes the liquid vibration reduction effect through the two-liquid stratification characteristics and simultaneously uses a partition structure to suppress regular liquid flow, thereby improving the stability and safety of wind turbine operation.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A dual-liquid vibration damping sloshing chamber for wind turbine towers, designed for source-grid-load-storage synergy, is disclosed. The dual-liquid vibration damping sloshing chamber is an external sloshing damping structure mounted on the wind turbine body. The wind turbine body comprises wind turbine blades and a wind turbine tower, and is a conventional structure. The sloshing damping structure includes a wind vane, a sloshing chamber structure, and a turntable fixing structure. The sloshing chamber structure consists of an annular sloshing chamber, a liquid baffle, an upper liquid layer, and a lower liquid layer. The turntable fixing structure consists of a rotor and a rotor flange.

[0008] The annular sloshing chamber has a central through-hole and is fitted onto the wind turbine tower. The annular sloshing chamber contains a liquid baffle and is filled with two immiscible liquids with a certain density difference, forming an upper liquid layer and a lower liquid layer. The wind vane is arranged on the outside of the annular sloshing chamber. The sloshing damping structure is fixed to a fixed section of the wind turbine tower via a rotor flange, and a rotor is mounted on the rotor flange.

[0009] Furthermore, the wind vane is a rectangular plate structure, with at least two pieces arranged radially symmetrically on the outside of the annular sloshing chamber. The height of the wind vane is the same as the axial height of the annular sloshing chamber, both being H. The width of the wind vane 4 is... Its value is related to the height H of the annular sloshing tank, and can be specifically taken as... .

[0010] Furthermore, the annular liquid sloshing chamber has an annular cylindrical structure with an inner diameter of b and an outer diameter of a. When filled with a two-phase liquid, it naturally separates into an upper liquid layer and a lower liquid layer. The static filling heights of the upper and lower liquid layers are respectively... , Furthermore, the lower layer of liquid is separated by a liquid baffle under static conditions to reduce the resonant amplification effect caused by the lower layer of liquid, which acts as the main damper for sloshing, forming annular flow within the annular sloshing chamber.

[0011] Furthermore, the liquid baffles are arranged radially at eight equal division points of the annular sloshing chamber, with their width equal to the difference between the outer and inner diameters of the annular sloshing chamber and their height the same as the height of the lower liquid layer.

[0012] Furthermore, the axes of the rotor flange, the annular liquid sloshing chamber, and the wind turbine tower coincide. The rotor flange is an annular slide rail structure with circumferentially arranged tracks to accommodate the rotor's rolling or sliding. The rotor flange has limiting structures on both axial sides to restrict the rotor's axial displacement and prevent it from detaching. The rotor has a cross-sectional radius of... ,high The columnar structure is evenly distributed along the circumferential direction of the rotor flange, and the number of rotors is 6 to 10. The outer diameter of the limiting structure at both ends of the rotor flange is the inner diameter b of the annular sloshing chamber. The width of the limiting structure is the same as the cross-sectional radius of the rotor, therefore its inner diameter is... The height is Under wind load, the rotor passively rolls or slides between the rotor flange and the outer wall of the wind turbine tower, thereby enabling the sloshing liquid damping structure to achieve fixed-axis, adaptive rotation around the wind turbine tower axis.

[0013] Furthermore, the wind vane is coaxial with one of the pairs of liquid baffles on the same radial axis. Under wind load, the sloshing damping structure spins and stabilizes to the point where the wind vane's wind-blocking area is minimized, i.e., parallel to the wind direction. This allows each sloshing zone divided by the liquid baffles to reach the maximum sloshing path in the wind direction, i.e., the main vibration direction of the wind turbine tower, thereby maximizing the sloshing damping vibration reduction effect.

[0014] Furthermore, the upper liquid is No. 2 white oil, and the lower liquid is a water-based antifreeze liquid mixed with water and propylene glycol in a volume ratio of 7:3. The upper and lower liquids are immiscible and form a stable layered interface.

[0015] Furthermore, the injection heights of the upper and lower liquid layers are related to the structural dimensions of the annular sloshing chamber, and are determined as follows:

[0016] Step 1: The sum of the injection heights of the upper and lower liquid layers is the height H of the annular sloshing chamber.

[0017] (1)

[0018] in, This indicates the pouring height of the upper liquid layer under static conditions; This indicates the pouring height of the lower layer of liquid under static conditions;

[0019] Step 2, the ratio K of the inner and outer diameters of the annular sloshing chamber is as shown in equation (2):

[0020] (2)

[0021] Where a is the outer diameter of the annular sloshing chamber; b is the inner diameter of the annular sloshing chamber.

[0022] Step 3: Analyze the radial eigenfunction of the annular sloshing tank using the Bessel function shown in equation (3), and substitute it into the boundary conditions of zero velocity at the inner and outer boundaries of the annular sloshing tank as shown in equations (4) and (5) to obtain the two equations shown in equations (6) and (7).

[0023] (3)

[0024] (4)

[0025] (5)

[0026] (6)

[0027] (7)

[0028] In the formula, Let r be the eigenfunction of the liquid velocity potential function in the radial direction; r is the independent variable; M and N are undetermined coefficients. This represents a first-order Bessel function of the first kind. This represents the derivative of a first-order Bessel function of the first kind; This represents a first-order Bessel function of the second kind. This indicates the derivative of the first-order Bessel function of the second kind.

[0029] In order to Equations (6) and (7) must be linearly related, from which the wavenumber equation shown in equation (8) can be derived:

[0030] (8)

[0031] In the formula, Let K represent the nth positive root of the wave number equation. Substituting K into the equation will yield the solution.

[0032] Step 4: Since equation (8) is a transcendental equation, its solution is a series of positive roots, corresponding to different orders of sloshing modes of the liquid. In engineering design, the lowest order positive root is generally taken to characterize the dominant sloshing mode. Therefore, this invention takes the first positive root of equation (8). Subsequent calculations, as shown in equation (9), yielded the horizontal wavenumber. :

[0033] (9)

[0034] Step 5: Ignoring liquid surface tension, the annular sloshing chamber is filled with two immiscible phases, forming a stable two-liquid interface with no single free liquid surface. The natural frequency of the liquid sloshing... The frequency should be close to the vibration frequency of the wind turbine tower itself, generally between 0.2 and 2 Hz, in order to counteract the vibration of the wind turbine tower itself. The specific calculation is shown in equation (10).

[0035] (10)

[0036] In the formula, The density of the upper liquid layer, Let g be the density of the lower liquid layer and g be the acceleration due to gravity.

[0037] Step 6: Under the given dimensions of the annular sloshing chamber and the vibration frequency of the wind turbine tower, the injection height of the upper liquid and the injection height of the lower liquid under static conditions are calculated by combining equations (1) and (10).

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] (1) This invention replaces a single sloshing liquid with a stable, layered, immiscible dual liquid, which can effectively reduce energy dissipation and damping attenuation caused by the breakage of the sloshing liquid, thereby improving the vibration reduction effect of the sloshing liquid damping structure. At the same time, the dual liquid injection ratio can be flexibly adjusted by utilizing the vibration frequency of the wind turbine tower, which can accurately adapt to all working conditions.

[0040] (2) In this invention, the linkage between the wind vane and the liquid baffle can drive the sloshing tank to spin to the optimal damping state, improve the vibration reduction efficiency of the sloshing damping structure, and can autonomously adjust in complex wind field environments with multiple wind directions and strong turbulence, with low energy consumption.

[0041] (3) In this invention, the liquid partition divides the sloshing chamber into relatively independent sloshing zones, which can effectively prevent the annular flow of the lower liquid, suppress the generation of resonance effect, and enhance the stability of the vibration reduction effect of the sloshing damping structure. Attached Figure Description

[0042] Figure 1 A schematic diagram of a wind turbine containing an annular liquid sloshing chamber;

[0043] Figure 2 This is a front view of the sloshing liquid tank;

[0044] Figure 3 Top view of the liquid sloshing tank;

[0045] Figure 4 This is a schematic diagram of the sloshing liquid tank structure;

[0046] In the diagram: 1 Wind turbine blade; 2 Wind turbine tower; 3 Annular liquid sloshing chamber; 4 Wind vane; 5 Liquid baffle; 6 Upper liquid; 7 Lower liquid; 8 Rotor; 9 Rotor flange. Detailed Implementation

[0047] The present invention will be further described below with reference to specific implementation examples.

[0048] A dual-liquid damping sloshing chamber for wind turbine towers, designed for source-grid-load-storage synergy, is an external sloshing damping structure mounted on the wind turbine body. The wind turbine body comprises wind turbine blades 1 and a wind turbine tower 2, which is a conventional structure. The sloshing damping structure consists of three parts: a wind vane 4; a sloshing chamber structure composed of an annular sloshing chamber 3, a liquid baffle 5, an upper liquid layer 6, and a lower liquid layer 7; and a turntable fixing structure composed of a rotor 8 and a rotor flange 9.

[0049] The annular sloshing chamber 3 has a central through hole and is fitted onto the wind turbine tower 2. The wind vane 4 is arranged on the outside of the annular sloshing chamber 3. The annular sloshing chamber 3 is equipped with a liquid baffle 5 and filled with two immiscible liquids with a certain density difference, forming an upper liquid layer 6 and a lower liquid layer 7. The sloshing damping structure is fixed to a fixed section of the wind turbine tower 2 via a rotor flange 9.

[0050] In this embodiment, the wind vane 4 is a rectangular plate structure, with two pieces arranged radially symmetrically on the outside of the annular sloshing tank 3. The height of the wind vane 4 is the same as the axial height of the annular sloshing tank 3, both being H. In this embodiment, H is used. Meters. The width of wind vane 4 is... Its value is related to the height H of the annular sloshing chamber 3, and can be specifically taken as... This embodiment takes ,Right now Meters. Furthermore, the annular sloshing chamber 3 has an annular cylindrical structure with an inner diameter of b and an outer diameter of a. In this embodiment, it is taken as... rice, Meters. The interior is filled with a two-phase liquid, which naturally separates into an upper liquid layer 6 and a lower liquid layer 7. The static filling heights of the upper liquid 6 and the lower liquid 7 are respectively... , Furthermore, the lower liquid 7 is separated by the liquid baffle 5 under static conditions to reduce the resonant amplification effect caused by the lower liquid 7 forming annular flow in the annular sloshing chamber 3, which is the main body of sloshing damping.

[0051] In this embodiment, the axes of the rotor flange 9, the annular sloshing chamber 3, and the wind turbine tower 2 coincide. The rotor flange 9 is an annular slide rail structure, with a track circumferentially arranged to accommodate the rolling or sliding of the rotor 8. The rotor flange 9 has limiting structures on both axial sides to restrict the axial displacement of the rotor 8 and prevent it from detaching. The rotor 8 has a cross-sectional radius of... ,high The columnar structure, in this embodiment, is taken as... rice, The rotors 8 are evenly distributed along the circumference of the rotor flange 9, and the number of rotors 8 is 6 to 10; in this embodiment, 8 are used. The outer diameter of the limiting structure at both ends of the rotor flange 9 is the inner diameter b of the annular sloshing chamber. The width of the limiting structure is the same as the cross-sectional radius of the rotor 8, therefore its inner diameter is... That is, 6.6 meters, with a height of That is, 0.2 meters. Under wind load, the rotor 8 passively rolls or slides between the rotor flange 9 and the outer wall of the wind turbine tower 2, thereby enabling the sloshing liquid damping structure to achieve fixed-axis, adaptive rotation around the axis of the wind turbine tower 2.

[0052] In this embodiment, the liquid baffles 5 are arranged radially at eight equal points on the annular sloshing chamber 3, and their width is equal to the difference between the outer diameter and the inner diameter of the annular sloshing chamber 3. That is, 3 meters, the same height as the lower liquid 7;

[0053] In this embodiment, the wind vane 4 and one of the pair of liquid baffles 5 on the same radial axis are kept coaxial. Under wind load, the sloshing damping structure rotates and stabilizes to the point where the wind vane 4 has the smallest wind-blocking area, that is, a position parallel to the wind direction. This allows each sloshing zone divided by the liquid baffles 5 to reach the maximum sloshing path in the wind direction, i.e., the main vibration direction of the wind turbine tower 2, so as to maximize the sloshing damping vibration reduction effect.

[0054] In this embodiment, the upper liquid 6 is No. 2 white oil, and its density is taken as follows: The lower liquid 7 is a water-based antifreeze liquid with a water-propylene glycol ratio of 7:3, and its density is taken as... The upper and lower liquids are immiscible and form a stable stratification interface.

[0055] In this embodiment, the injection height of the upper liquid 6 and the lower liquid 7 is related to the structural dimensions of the annular sloshing chamber 3, and is determined as follows:

[0056] Step 1: The sum of the injection heights of the upper liquid 6 and the lower liquid 7 is the height H of the annular sloshing chamber 3.

[0057] Step 2, the inner and outer diameter ratio K of the annular sloshing chamber 3 is as shown in equation (2). .

[0058] Step 3: As shown in equation (3), the radial eigenfunction of the annular sloshing tank 3 is analyzed by the properties of the Bessel function. Substituting the boundary conditions of zero velocity at the inner and outer boundaries of the annular sloshing tank 3 as shown in equations (4) and (5), we can obtain two equations as shown in equations (6) and (7).

[0059] In order to make M Equations (6) and (7) must be linearly related, thus deriving the wave number equation shown in equation (8).

[0060] Step 4: Since equation (8) is a transcendental equation, its solution is a series of positive roots, corresponding to different orders of sloshing modes of the liquid. In engineering design, the lowest order positive root is generally taken to characterize the dominant sloshing mode. Therefore, this invention takes the first positive root of equation (8). Subsequent calculations yielded the solution in this embodiment. As shown in equation (9), the horizontal wavenumber is obtained. .

[0061] Step 5: Ignoring liquid surface tension, the annular sloshing chamber 3 is filled with two immiscible phases, forming a stable two-liquid stratification interface with no single free liquid surface. The natural frequency of liquid sloshing. The frequency should be close to the vibration frequency of the wind turbine tower 2 itself, generally between 0.2 and 2 Hz. In this embodiment, we take... This is to counteract the vibration of the wind turbine tower 2 itself, and the specific calculation is shown in equation (10).

[0062] Step 6, under the given dimensions of the annular sloshing chamber 3 and the vibration frequency of the wind turbine tower 2, take... By combining equations (1) and (10), the injection height of the upper liquid 6 under static conditions is calculated to be 0.381 meters and the injection height of the lower liquid 7 under static conditions is 1.619 meters.

[0063] The above embodiments are merely illustrative of the implementation methods of the present invention, but should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A wind turbine tower double-liquid damping and sloshing tank oriented towards source network load storage cooperation, the wind turbine tower double-liquid damping and sloshing tank is a sloshing damping structure externally provided on a wind turbine body; the wind turbine body comprises a wind turbine blade (1) and a wind turbine tower (2), characterized in that, The liquid-sloshing damping structure comprises a wind direction plate (4), a liquid-sloshing tank structure, and a rotating disc fixing structure; the liquid-sloshing tank structure is composed of an annular liquid-sloshing tank (3), a liquid partition plate (5), an upper liquid (6), and a lower liquid (7); and the rotating disc fixing structure is composed of a rotor (8) and a rotor flange plate (9). The annular liquid-sloshing tank (3) is provided with a central through hole and is sleeved on the wind turbine tower (2); the annular liquid-sloshing tank (3) is provided with a liquid partition plate (5) and is filled with two-phase liquid with density difference and immiscibility; and the two-phase liquid is naturally stratified into an upper liquid (6) and a lower liquid (7); the wind direction plate (4) is arranged outside the annular liquid-sloshing tank (3); and the liquid-sloshing damping structure is fixed to the fixed segment of the wind turbine tower (2) through the rotor flange plate (9), and the rotor flange plate (9) is provided with the rotor (8). The annular liquid sloshing tank (3) is in the form of an annular cylinder with an inner diameter of b and an outer diameter of a; the filling heights of the upper liquid (6) and the lower liquid (7) under static conditions are respectively , , and the lower liquid (7) is separated by the liquid partition (5) under static conditions.

2. The wind turbine tower double-liquid damping and sloshing tank oriented to source network load storage collaboration according to claim 1, characterized in that, The wind direction plate (4) is specifically a rectangular plate structure, and at least two pieces thereof are arranged outside the annular liquid-sloshing tank (3) in a radial direction. The height of the wind direction plate (4) is the same as the height of the annular liquid-sloshing tank (3) in an axial direction, and both are H. The liquid partition plate (5) is arranged at eight equally divided points of the annular liquid-sloshing tank (3) in a radial direction, and the width of the liquid partition plate (5) is equal to the difference between the outer diameter and the inner diameter of the annular liquid-sloshing tank (3), and the height of the liquid partition plate (5) is the same as the height of the lower liquid (7). The width of the wind direction plate (4) is , which is related to the height H of the annular sloshing tank (3), and is specifically taken as .

3. The wind turbine tower double-liquid damping and sloshing tank oriented to source network load storage collaboration according to claim 1, characterized in that, The axis of the rotor flange plate (9), the annular liquid-sloshing tank (3), and the wind turbine tower (2) coincide with each other.

4. The wind turbine tower double-liquid damping and sloshing tank oriented to source network load storage collaboration according to claim 1, characterized in that, The rotor flange plate (9) is an annular slide rail structure, and is provided with a track for accommodating rolling or sliding of the rotor (8) in a circumferential direction; and the rotor flange plate (9) is provided with a limiting structure on both sides in an axial direction, for limiting axial displacement of the rotor (8). Under the action of wind load, the rotor (8) passively rolls or slides between the rotor flange plate (9) and the outer wall of the wind turbine tower (2), so that the liquid-sloshing damping structure rotates around the axis of the wind turbine tower (2) in a fixed-axis and self-adaptive manner. The rotor (8) is a cylindrical structure with a cross-sectional radius , high . The outer diameter of the limiting structure at both ends of the rotor flange (9) is the inner diameter b of the annular liquid sloshing tank (3), and the width of the limiting structure is the same as the cross-sectional radius of the rotor (8), and the inner diameter thereof is , and the height is ; The number of the rotors (8) is 6-10.

5. The wind turbine tower double-liquid damping and sloshing tank oriented to source network load storage collaboration according to claim 1, characterized in that, The upper liquid (6) is No. 2 white oil, and the lower liquid (7) is water-based antifreeze liquid mixed by water and propylene glycol in a volume ratio of 7:

3.

6. The wind turbine tower double-liquid damping and sloshing tank oriented to source network load storage collaboration according to claim 1, characterized in that, The filling height of the upper liquid (6) and the lower liquid (7) is related to the structural size of the annular liquid-sloshing tank (3).

7. The wind turbine tower double-liquid damping and sloshing tank oriented to source network load storage collaboration according to claim 1, characterized in that, The upper liquid (6) and the lower liquid (7) are filled to a height H of the annular liquid-sloshing tank (3).

8. The wind turbine tower double-liquid damping and sloshing tank oriented to source network load storage collaboration according to claim 7, characterized in that, Step 2, the inner-to-outer diameter ratio K of the annular liquid-sloshing tank (3) is as shown in formula (2): wherein a is the outer diameter of the annular liquid-sloshing tank (3); and b is the inner diameter of the annular liquid-sloshing tank (3); （1）； wherein represents the filling height of the upper liquid (6) in static; represents the filling height of the lower liquid (7) in static; Step 3, the radial eigenfunction of the annular liquid-sloshing tank (3) is analyzed by a Bessel function as shown in formula (3); the boundary conditions that the velocity of the annular liquid-sloshing tank (3) at the inner and outer boundaries is zero are substituted into formula (4) and formula (5); and two equations as shown in formula (6) and formula (7) are obtained. （2）； ​ ​ （3）； （4）； （5）； （6）； （7）； wherein is the eigenfunction of the liquid velocity potential function in the radial direction; r is the independent variable; M and N are undetermined coefficients; denotes the first order first kind Bessel function, denotes the derivative of the first order first kind Bessel function; denotes the first order second kind Bessel function, denotes the derivative of the first order second kind Bessel function; In order to make , formula (6), formula (7) linear correlation, thus deduced as shown in equation (8) wave number equation: （8）； wherein denotes the nth positive root of the wave number equation; Step 4, take the first positive root of equation (8) The horizontal wave number is then calculated as shown in equation (9) : （9）； Step 5, ignoring the liquid surface tension, the natural frequency of liquid sloshing Approaching the vibration frequency of the wind turbine tower (2) itself, the calculation is shown as formula (10); （10）； wherein is the density of the upper liquid (6), is the density of the lower liquid (7), g is the acceleration due to gravity; Step 6, the filling height of the upper liquid (6) in static state and the filling height of the lower liquid (7) in static state are calculated by formula (1) and formula (10) under the given size of the annular sloshing tank (3) and the vibration frequency of the wind turbine tower (2).

9. The wind turbine tower double-liquid damping and sloshing tank oriented to source network load storage collaboration according to claim 8, characterized in that, In the step 5, the vibration frequency of the wind turbine tower (2) itself is 0.2-2 Hz.

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