CN107905941B - A kind of horizontal-shaft wind turbine and its application method - Google Patents

Abstract

A horizontal axis wind turbine and its use method, including a tower, a nacelle, a main hub, wind rotor blades and a retracting mechanism; the nacelle is installed on the top of the tower, the main hub is installed on the front end of the nacelle, and the plurality of wind rotor blades are evenly spaced Arranged around the main hub, the wind rotor blades are connected to the main hub through a retracting mechanism. The retracting mechanism enables the rotor blades to rotate at the blade root and move closer to the nacelle, so that the span direction of the rotor blades is perpendicular to the rotation plane of the rotor. When the wind turbine suffers from strong wind or typhoon, by improving the wind rotor blades and the retracting mechanism, the wind rotor blades can be folded and rotated near the blade root, and move closer to the nacelle. The wind shears the unstable load, and at the same time greatly reduces the wind load area of the wind turbine, thereby reducing the load on the horizontal axis wind turbine after shutdown, which is of great significance to improving the typhoon resistance of the wind turbine and ensuring the life of the wind turbine.

Description

Horizontal axis wind turbine and method of use thereof

technical field

The invention belongs to the field of wind power generation, and in particular relates to a horizontal axis wind turbine and a method for using the same.

Background technique

When an offshore wind turbine encounters a typhoon, the structure of the wind turbine is likely to be severely damaged, especially some damage is fatal. For the anti-typhoon design of offshore horizontal axis wind turbines, domestic and foreign scholars have carried out a lot of research work, such as increasing the structural strength of the tower, improving the vibration damping of wind turbines, and improving the pitch and yaw systems. For the typhoon-resistant design of offshore wind turbines, there are many methods, but basically passively increase the structural strength of wind turbines, or increase structural damping, etc., which have strong limitations on measures such as pitch and yaw. However, the wind speed of a typhoon has the characteristics of high wind speed and changing wind speed direction. The common method will not only increase the cost, but also will soon have a limit, that is, the structure of the wind turbine is easily damaged by a strong typhoon.

Contents of the invention

Aiming at the deficiencies in the prior art, the present invention provides a horizontal-axis wind turbine and its use method, and especially provides an effective measure for typhoon resistance of the three-blade offshore horizontal-axis wind turbine.

To achieve the above object, the present invention adopts the following technical solutions:

A horizontal axis wind turbine, characterized in that it includes: a tower, a nacelle, a main hub, wind rotor blades and a retracting mechanism; the nacelle is installed on the top of the tower, the main hub is installed on the front end of the nacelle, The wind rotor blades are evenly arranged around the main hub, and the wind rotor blades are connected with the main hub through a retracting mechanism. perpendicular to the plane of rotation of the rotor.

In order to optimize the above technical solutions, the specific measures taken also include:

The folding mechanism includes a spherical hub and a rotating connector. One end of the spherical hub is connected to the main hub, and the other end of the spherical hub is connected to a rotating connector. The rotating connector is fixedly connected to the wind turbine blade, and the rotating connector drives The rotor blades rotate around the axis of the spherical hub.

An arc-shaped slideway groove is provided in the spherical hub, and the arc range of the slideway groove is 180°; the spherical hub is also provided with a flange supporting and fixing boss, a two-half flange, a motor fixing table, a drive The motor and the connecting slider, the slideway groove, the flange support fixed boss and the two half flanges are coaxially arranged; the flange support fixed boss is arranged around the inner wall of the spherical hub, and the flange support fixed boss is fixed with Two-half flanges, the two-half flanges are arranged close to the inner wall of the spherical hub; the motor fixing table is fixed on the inner wall of the spherical hub, and a driving motor is installed on the motor fixing table, and the output shaft of the driving motor The driving gear is fixed on the top, and the driving gear is meshed with the two half flanges; the connecting slider is matched with the slideway groove, and one end of the connecting slider is fixedly connected with the two half flanges, and the other end of the connecting slider One end protrudes out of the slideway groove and is fixedly connected with the rotary connector, the drive motor drives the two half flanges to rotate, and the two half flanges drive the connecting slider to slide in the slideway groove, thereby driving the rotary connector to rotate around the spherical hub.

The number of the slideway groove, the flange support fixing boss, the two half flanges and the connecting sliders are all two and have a one-to-one correspondence with each other, and the motor fixing table is installed between the two half flanges. In the middle, the driving motor adopts a double output shaft motor, and the upper and lower output shafts of the driving motor are respectively matched with two half flanges.

The spherical hub is also provided with a slideway groove cover plate and a cover plate support, the slideway groove cover plate is arc-shaped, and the two ends of the slideway groove cover plate are fixed on the connecting sliders for covering the slideway The gap of the groove, the cover plate support is fixed on the inner wall of the spherical hub to support and guide the slideway groove cover plate.

Two side shrouds are detachably installed on both sides of the spherical hub.

In addition, a method for using the above horizontal axis wind turbine is also proposed, wherein the number of wind rotor blades is three, and it is characterized in that it includes the following steps:

Step 1. When the wind speed is greater than the rated wind speed for a long time or a typhoon warning is received, the horizontal axis wind turbine is shut down, one of the three wind rotor blades is vertical to the upper surface of the nacelle, and the other two are distributed on both sides of the nacelle;

Step 2: Rotate the pitch angle of the upper blade to 0°, and rotate the pitch angles of the other two blades to 60° and 120° respectively, even if the pitch angle of the first blade along the direction of rotation is 60°, the pitch angle of the second blade is 120°;

Step 3: Start the driving motor, drive the two two-half flanges to rotate through the four driving gears, and the three rotating connectors start to rotate along the slideway groove, so that the wind rotor blades move closer to the nacelle. When the three wind rotor blades When they rotate 90° around the spherical hub at the blade root, the control strategy of the wind turbine against strong wind is completed;

Step 4. When the wind turbine needs to operate normally to generate electricity after the typhoon or strong wind passes, reverse the above steps to realize the return of the wind rotor blades to the normal operating condition.

The beneficial effects of the present invention are: by increasing the retracting mechanism of the blades, specifically including the spherical hub and the rotating connector, the action of the blades of the wind turbine moving closer to the nacelle is realized, so that the rotation plane of the wind rotor of the wind turbine presents a retracted state, and the two sides of the nacelle The trailing edge of the side blades faces outward, that is, the chord direction is perpendicular to the two sides of the nacelle, and the chord length direction of the blades directly above the nacelle is parallel to the upper surface of the nacelle, thereby greatly reducing the area of the wind rotor blades subjected to positive and lateral wind loads. At the same time, it weakens the unstable wind load intensity caused by the wind shearing of the blades, so that the load of the wind turbine blades and the whole machine is greatly reduced, and finally achieves the effect of resisting typhoons and strong winds.

Description of drawings

Figure 1a is an overall front view of the present invention.

Figure 1b is an overall side view of the present invention.

Fig. 2a is an overall side view of the blades of the present invention in a folded state.

Fig. 2b is a partial side view of the blades of the present invention in a folded state.

Fig. 3a is a top view of the folding mechanism of the present invention.

Fig. 3b is a side view of the folding mechanism of the present invention.

Fig. 3c is a front view of the folding mechanism of the present invention.

Fig. 3d is a perspective view of the folding mechanism of the present invention.

Fig. 4 is a schematic connection diagram of the folding mechanism of the present invention.

Fig. 5 is a schematic structural view of the spherical hub of the present invention.

Fig. 6 is a schematic structural view of the slideway groove cover plate of the present invention.

Fig. 7 is a comparison diagram of the wind load on the blade under the forward flow working condition of the normal blade state and the blade retracted state of the present invention.

Fig. 8 is a comparison diagram of the blade bending moment under the forward flow working condition of the normal blade state and the blade retracted state of the present invention.

The reference signs are as follows: tower 1, nacelle 2, main hub 3, wind rotor blade 4, retracting mechanism 5, spherical hub 6, rotating connector 7, main hub connecting end 8, slideway groove 9, flange support fixing protrusion Table 10, two half flanges 11, motor fixing table 12, driving motor 13, connecting slider 14, driving gear 15, slideway groove cover plate 16, cover plate support 17, shroud 18.

Detailed ways

The present invention is described in further detail now in conjunction with accompanying drawing.

A horizontal-axis wind turbine as shown in FIGS. 1a and 1b includes a tower 1 , a nacelle 2 , a main hub 3 , rotor blades 4 and a retracting mechanism 5 . The nacelle 2 is installed on the top of the tower 1, and the main hub 3 is installed at the front end of the nacelle 2. There are three wind rotor blades 4, which are evenly arranged around the main hub 3. The main hub 3 is first connected to the retracting mechanism 5, and then connected to the wind rotor Blade 4. The wind rotor blades 4 are folded toward the nacelle 2 through an independent retracting mechanism 5 of each wind rotor blade 4 . Under the action of the improved wind rotor blades 4 and the retracting mechanism 5, the wind rotor blades 4 rotate near the blade roots, and all the wind rotor blades 4 move closer to the nacelle 2, so that the span direction of the wind rotor blades 4 is perpendicular to the rotation plane of the wind rotor. The chord length direction of the rotor blade 4 can be parallel to the side flow direction, and the retracted state of the wind rotor blade 4 is shown in Figures 2a and 2b.

Referring further to Figures 3a-3d, the retracting mechanism 5 includes a spherical hub 6 and a rotary connector 7. One end of the spherical hub 6 is connected to the main hub 8, and the spherical hub 6 and the main hub 3 can be connected by bolts, and the other end is connected to the rotary connection. Item 7. The specific connection is shown in FIG. 4 . The rotating connector 7 is fixedly connected to the wind rotor blade 4 through bolts, and the rotating connector 7 drives the wind rotor blade 4 to rotate around the axis of the spherical hub 6 . Both sides of the spherical hub 6 are also provided with two side shrouds 18. When the wind rotor blade 4 is in normal operation, it has the effect of ensuring the diversion of the blade root flow field, and has a detachable function at the same time. Provide space.

As shown in FIG. 5 , an arc-shaped slideway groove 9 is opened in the spherical hub 6 , and the arc range of the slideway groove 9 is 180°. Spherical hub 6 is also provided with flange support fixed boss 10, two half flanges 11, motor fixing table 12, drive motor 13 and connecting slide block 14, slideway groove 9, flange support fixed boss 10 and two The half flanges 11 are arranged coaxially. The flange support fixed boss 10 is arranged around the inner wall of the spherical hub 6, and the flange support fixed boss 10 is fixed with two half-type flanges 11, and the two half-type flanges 11 can be decomposed into two half-circle flanges. Blue is close to the setting of spherical hub 6 inwalls. Motor fixing table 12 is fixed on the inwall of spherical hub 6, and driving motor 13 is installed on the motor fixing table 12, and driving gear 15 is fixed on the output shaft of driving motor 13, and driving gear 15 is meshed with two half flanges 11. The connecting slider 14 is matched with the slideway groove 9, and one end of the connecting slider 14 is fixedly connected with the two half-type flanges 11 through bolts, and the other end protrudes from the slideway groove 9 and is fixedly connected with the rotating connector 7, driven by a driving motor 13 The two-half flanges 11 rotate, and the two-half flanges 11 drive the connecting slider 14 to slide in the slideway groove 9 , thereby driving the rotating connector 7 to rotate around the spherical hub 6 along the slideway groove 9 .

Wherein, the number of the slideway groove 9, the flange support fixed boss 10, the two-half flange 11 and the connecting slider 14 are two and have a one-to-one correspondence with each other, and the motor fixing table 12 is installed on two Between the half flanges 11, the driving motor 13 adopts a double output shaft motor, and the upper and lower output shafts of the driving motor 13 are matched with the two half flanges 11 respectively.

Referring further to FIG. 6 , the spherical hub 6 is also provided with a slideway groove cover 16 and a cover support 17 , the slideway groove cover 16 is arc-shaped, and the two ends of the slideway groove cover 16 are fixed on the connecting slider 14 Above, it is used to cover the gap of the slideway groove 9, and the cover plate support 17 is fixed on the inner wall of the spherical hub 6 to support and guide the slideway groove cover plate 16.

In engineering applications, wind turbines at sea and along the coast often encounter typhoon weather, resulting in varying degrees of damage to the wind turbines. Therefore, for the special situation of this strong wind, a wind turbine with rotatable and retractable wind rotor blades is provided, and the corresponding anti-typhoon strategy is given at the same time, that is, the use method of the horizontal axis wind turbine with anti-strong wind function, including the following steps:

Step 1. When the wind farm receives a typhoon warning, the wind turbine starts to execute the anti-strong wind control strategy instruction. The wind rotor blades 4 run to the positions shown in Figures 1a and 1b to stop, that is, one of the three blades is perpendicular to the upper surface of the nacelle, and the other two blades are distributed on both sides of the nacelle.

Step 2. Different from the requirement of pitching to 90° when the general wind turbine is shut down, this method requires that the pitch angle of the upper blade is rotated to 0°, and the other two blades are rotated by 60° and 120° respectively (even along the The pitch angle of the first blade in the direction of rotation is 60°, the second blade is 120°).

Step 3: Start the motor system, drive the two half flanges 11 to rotate through the four driving gears 15, and realize that the three rotating connectors 7 start to rotate along the slideway groove 9, so that the wind rotor blades 4 move closer to the nacelle 2 When the rotation angle reaches 90°, the control strategy of the wind turbine against strong wind is completed (as shown in Figures 2a, 2b, and 4).

Step 4: When the wind turbine needs to operate normally to generate electricity after the typhoon or strong wind passes, reverse the above steps to realize the return of the wind rotor blade 4 to the normal operating condition.

When the wind rotor blades 4 are all in the state of moving closer to the nacelle, when the wind turbine encounters a typhoon, it has a great protective effect, which mainly reflects three aspects: the first, the wind receiving area of the wind turbine is reduced, and the wind turbine is reduced. The wind load received, no matter the incoming flow is blown from the front or from the back, can achieve a good load reduction effect, even from the side, due to the control of the blade pitch and the regulation of the chord length of the blade, the side The wind-receiving area of the incoming flow is also greatly reduced; second, the three blades of the wind turbine are close together, so that the horizontal height difference of the blade positions is very small, which greatly weakens the wind shear effect of the wind turbine blades, so that the fatigue load and ultimate load will be weakened; Third, the blades of the wind turbine are close to the surroundings of the nacelle (as shown in Figure 2a and 2b), which destroys the incoming flow field of the nacelle, making the nacelle less affected by strong winds and protecting the nacelle from being damaged by strong winds. These play an important role in the structural protection and service life of the wind turbine.

Taking a 5MW wind turbine as an example, the tower height is 126m, the radius of the wind rotor is 60m, and the incoming wind speed is 40m/s. The CFD numerical flow field simulation calculation of the front flow condition and the side flow condition of the wind rotor rotation plane is carried out. The flow field calculation using the method of solving the Reynolds average equation, the grid is 11 million, and the wind speed of the two working conditions is a strong wind condition of 35m/s. The loads on the blade root of the front and side flow of the wind rotor rotation plane, including the blade root bending moment and the blade root shear force, are calculated respectively under the folded and unfolded states of the three blades. (Blade 1: the blade vertical to the upper surface of the nacelle, on the upper surface of the nacelle; blade 2 and blade 3 are on both sides of the nacelle, wherein blade 2 is on the same side as the boundary of the side wind velocity incoming flow). Fig. 7 is the root shear diagram of the three blades under the frontal flow condition of the wind rotor rotation plane with the blades folded and not folded. It can be seen from the figure that after the blades are folded, the load on the blade root is greatly reduced, especially for blade 1 Said that due to the greatly reduced frontal area, the load is reduced by 94%; the other two blades can also reduce the load by about 70% to 80%. Fig. 8 is the root shear diagram of the three blades under the side flow condition of the wind rotor rotation plane with the blades folded and not folded. It can be seen from the figure that the blade root load on blade 2 is the largest, but after the blades are folded, three The root loads of the two blades are all reduced, and blade 3 is protected by blade 2 and the nacelle, the load reduction is the most obvious, and the loads of blades 1, 2, and 3 are reduced by 32%, 53%, and 80% respectively.

To sum up, the present invention has a wide range of applications and can be used for land and sea wind turbines. It has the function of significantly reducing the load of large wind turbines against strong winds, and is of great significance for the development of large-scale wind turbines and offshore wind farms.

It should be noted that terms such as "upper", "lower", "left", "right", "front", and "rear" quoted in the invention are only for clarity of description, not for Limiting the practicable scope of the present invention, and the change or adjustment of the relative relationship shall also be regarded as the practicable scope of the present invention without substantive changes in the technical content.

The above are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions under the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims (5)

1. A horizontal axis wind turbine, characterized in that it comprises: a tower (1), a nacelle (2), a main hub (3), a wind rotor blade (4) and a retracting mechanism (5); the nacelle (2 ) is installed on the top of the tower (1), the main hub (3) is installed at the front end of the nacelle (2), and a plurality of wind rotor blades (4) are evenly arranged around the main hub (3), the wind rotor The blades (4) are connected to the main hub (3) through the retracting mechanism (5), and the retracting mechanism (5) enables the wind rotor blades (4) to rotate at the blade roots and move closer to the nacelle (2), so that the wind rotor The span direction of the blade (4) is perpendicular to the rotation plane of the wind rotor; The folding mechanism (5) includes a spherical hub (6) and a rotating connector (7), one end of the spherical hub (6) is connected to the main hub connecting end (8), and the other end of the spherical hub (6) is connected to the rotating connection The rotating connector (7) is fixedly connected to the wind rotor blade (4), and the rotating connector (7) drives the wind rotor blade (4) to rotate around the axis of the spherical hub (6); The spherical hub (6) is provided with an arc-shaped slideway groove (9), and the arc range of the slideway groove (9) is 180°; the spherical hub (6) is also provided with a flange support fixing boss (10), two-half flange (11), motor fixing table (12), drive motor (13) and connecting slider (14), slideway groove (9), flange support fixing boss (10) and The two-half flanges (11) are arranged coaxially; the flange supporting and fixing boss (10) is arranged around the inner wall of the spherical hub (6), and the flange supporting and fixing boss (10) is fixed with two and a half flanges (11), the two-half flanges (11) are arranged close to the inner wall of the spherical hub (6); the motor fixing table (12) is fixed on the inner wall of the spherical hub (6), and the motor fixing table (12) A drive motor (13) is installed on the drive motor (13), and a drive gear (15) is fixed on the output shaft of the drive motor (13), and the drive gear (15) is meshed with the two half flanges (11); the connection The slide block (14) is matched with the slideway groove (9), and one end of the connecting slide block (14) is fixedly connected with the two half flanges (11), and the other end of the connecting slide block (14) extends out of the slideway groove ( 9) It is fixedly connected with the rotating connector (7), the driving motor (13) drives the two-half flange (11) to rotate, and the two-half flange (11) drives the connecting slider (14) in the slide groove (9) Sliding in the middle, thereby driving the rotating connector (7) to rotate around the spherical hub (6). 2. A horizontal axis wind turbine according to claim 1, characterized in that: the slide groove (9), the flange support fixing boss (10), the two-half flange (11) and the connecting slide The number of blocks (14) is two and they are in one-to-one correspondence. The motor fixing table (12) is installed between the two half flanges (11), and the driving motor (13) adopts a double output shaft motor. , the upper and lower output shafts of the drive motor (13) are matched with the two halves of the flanges (11) respectively. 3. A horizontal axis wind turbine according to claim 1, characterized in that: the spherical hub (6) is also provided with a slideway groove cover (16) and a cover support (17), the The slideway groove cover (16) is arc-shaped, and the two ends of the slideway groove cover (16) are fixed on the connecting slider (14) to cover the gap of the slideway groove (9), and the cover supports The part (17) is fixed on the inner wall of the spherical hub (6) to support and guide the slideway groove cover plate (16). 4. A horizontal axis wind turbine according to claim 1, characterized in that two side shrouds (18) are detachably mounted on both sides of the spherical hub (6). 5. A method for using a horizontal axis wind turbine according to claim 2, wherein the number of wind rotor blades (4) is three, and it is characterized by comprising the following steps: Step 1. When the wind speed is greater than the rated wind speed for a long time or a typhoon warning is received, the horizontal axis wind turbine is shut down, one of the three wind rotor blades (4) is vertical to the upper surface of the nacelle (2), and the other two are distributed in the nacelle (2) Both sides; Step 2: Rotate the pitch angle of the upper blade to 0°, and rotate the pitch angles of the other two blades to 60° and 120° respectively, even if the pitch angle of the first blade along the direction of rotation is 60°, the pitch angle of the second blade is 120°; Step 3: Start the drive motor (13), drive the two halves of the flange (11) to rotate through the four drive gears (15), and the three rotating connectors (7) start to rotate along the slide groove (9) , so that the wind rotor blades (4) move closer to the nacelle (2), and when the three wind rotor blades (4) rotate 90° around the spherical hub (6) at the blade root, the control strategy of the wind turbine against strong wind is completed; Step 4. When the wind turbine needs to operate normally to generate electricity after the typhoon or strong wind passes, reverse the above steps to realize the return of the wind rotor blade (4) to the normal operating condition.