CN106121915A - Blower fan hydraulic variable propeller system and method - Google Patents

Abstract

The invention discloses a fan hydraulic pitch change system and method. The system includes transmission devices correspondingly connected to the blades of the fan; a hydraulic system connected with each of the transmission devices; and a hydraulic system connected to the blades. The same number of limit parts; the pressure of the hydraulic system is a constant value, so that the blades can achieve real-time pitch change through the balance trend of the current wind load and the pressure of the hydraulic system; the constant value is when the unit is at full power Under the wind speed, the wind load received by the blade when it is kept at the position of the maximum wind receiving area; the limit position where the limit member can limit the rotation of the blade is the position of the maximum wind receiving area. The fan hydraulic pitch system can make the blades automatically adapt to the wind conditions and change the pitch in real time, so as to avoid power loss and waste of wind energy when the wind speed becomes small, and at the same time prevent component damage and unit failure when the wind speed is too high.

Description

Fan hydraulic pitch system and method

technical field

The invention relates to the technical field of wind power generation, in particular to a fan hydraulic pitch changing system and method.

Background technique

At present, the pitch system of wind turbines is passive, and the wind measuring system needs to monitor the average wind speed or monitor the impeller speed within a period of time. When the average wind speed is less than or equal to the full wind speed of the unit or the impeller speed is less than or equal to the full When the speed is high, the blades of the unit are at the position of the maximum wind receiving area. When the monitored average wind speed is greater than the full wind speed of the unit or the speed of the impeller is greater than the speed of the impeller at the full speed of the unit, the main control of the fan is fed back to the pitch system to make the blades passively change pitch. At this time, the pitch of the blades has hysteresis, and the following problems will exist:

The initial wind speed is small (less than the full wind speed), and the blade is at the position of the maximum wind receiving area. During a period of time monitored by the wind measuring system, if the wind speed becomes larger (greater than or equal to the full wind speed), because the wind measuring system has no feedback at this time The blades are pitched, so the wind load on the blades will increase during this period, and the generator will overspeed, so that the blades and related components will be subjected to abnormal loads due to sudden changes in wind speed, resulting in component damage and unit failure.

The initial wind speed is relatively high (greater than or equal to the full wind speed), and the blade is in a position where the wind receiving area is small. Feedback makes the blades pitch, so the wind load on the blades will be smaller during this period of time, and the power generation will be smaller than the wind speed at that time, resulting in power loss and wind energy waste.

In view of this, how to improve the pitch system of the existing fan, so that the blades of the fan can automatically adapt to the wind condition and change the pitch in real time, so as to avoid power loss and waste of wind energy when the wind speed becomes small, and at the same time prevent component damage and unit failure when the wind speed is too high , is a technical problem currently to be solved by those skilled in the art.

Contents of the invention

The purpose of the present invention is to provide a fan hydraulic pitch system and method, the fan hydraulic pitch system and method can make the blades automatically adapt to the wind conditions and real-time pitch, to avoid power loss and waste of wind energy when the wind speed becomes small, and at the same time prevent wind speed When it is too large, the parts will be damaged and the unit will fail.

In order to solve the above-mentioned technical problems, the present invention provides a fan hydraulic pitch system, which includes transmission devices correspondingly connected to the blades of the fan; also includes a hydraulic system power-connected to each of the transmission devices, and a hydraulic system connected to the blades The same number of limiting parts; the pressure of the hydraulic system is a constant value, so that the blades can achieve real-time pitching through the balance trend of the current wind load and the pressure of the hydraulic system;

The constant value is the wind load received by the unit when the blade is kept at the position of the maximum wind receiving area at full wind speed; the limit position where the limiting component can limit the rotation of the blade is the position of the maximum wind receiving area .

As above, the blade is connected to the hydraulic system through the transmission device, and the pressure of the hydraulic system is a constant value. This constant value makes the blade maintain the maximum wind receiving area position at the full wind speed of the unit, and the corresponding position is provided with a limiting member. To limit the extreme position of the blade rotation; that is to say, the force transmitted to the blade by the hydraulic system is in balance with the force received by the blade at the position of the maximum wind receiving area when the unit is at full wind speed, so that when the wind speed changes, the blade is affected The wind load changes accordingly, while the force transmitted to the blade by the hydraulic system remains constant. Under the action of the difference between the two, the blade can automatically rotate and pitch in the direction of a small or large wind receiving area, thereby realizing blade Automatically adapt to the wind conditions and change the pitch in real time, as follows:

The initial wind speed is small (less than the full wind speed), and the blade is at the position of the maximum wind receiving area. When the wind speed increases (greater than the full wind speed), the wind load on the blade becomes larger, which is greater than the force transmitted to the blade by the hydraulic system, and the blade overcomes the hydraulic pressure. The hydraulic energy of the system changes pitch in the direction of the small wind receiving area. Because the blades rotate and change pitch according to the difference between wind load and hydraulic pressure, it can automatically adapt to the wind condition and change pitch with fast response speed, which can avoid the traditional Increased wind load, damage to components and unit failures caused by abnormal loads on blades and related components;

The initial wind speed is high (greater than the full wind speed), and the blade is in a position with a small wind receiving area. When the wind speed becomes smaller (less than the full wind speed), the wind load on the blade becomes smaller, which is smaller than the force transmitted to the blade by the hydraulic system. The hydraulic system The hydraulic energy of the hydraulic energy is converted into mechanical energy output, and the blade is changed to the maximum wind receiving area through the transmission device. After the blade rotates to the maximum wind receiving area, it stops under the limit action of the limit component to avoid the waste of wind energy;

It can be seen from the above that the fan hydraulic pitch system provided by the present invention can make the blades automatically adapt to the wind conditions and change the pitch in real time, so as to avoid power loss and waste of wind energy when the wind speed becomes small, and at the same time prevent component damage and unit failure when the wind speed is too high.

Optionally, the hydraulic system includes two-way hydraulic motors with the same number as the transmission device, and the power output end of each two-way hydraulic motor is connected to the corresponding transmission device; the two oil ports of the two-way hydraulic motor They are respectively connected with the system pressure oil circuit and the oil return circuit.

Optionally, the hydraulic system further includes a hydraulic pump that drives each of the two-way hydraulic motors, and the oil outlet of the hydraulic pump is also communicated with the oil tank through the first overflow valve.

Optionally, the hydraulic system further includes a reversing valve, and the reversing valve is used to control the two oil ports of the bidirectional hydraulic motor to communicate with the system pressure oil circuit or the oil return oil circuit respectively.

Optionally, a second overflow valve is also provided between the oil return circuit and the oil tank.

Optionally, the hydraulic pump is a variable displacement pump.

Optionally, the transmission device includes a pitch bearing connected to the blade and a transmission member connected to the pitch bearing, and the transmission member is connected to the power output end of the bidirectional hydraulic motor.

Optionally, the transmission member is connected to the power output end of the bidirectional hydraulic motor through a bidirectional reducer.

Optionally, the transmission member is a toothed belt or a gear.

The present invention also provides a method for hydraulically changing the pitch of a fan. The method includes: providing a constant hydraulic pressure to the blades of the fan. The magnitude of the wind load received at the position; the blades are pitched in real time according to the balance trend of the current wind load and the constant hydraulic pressure, wherein the extreme position of the blade rotation is the position of the maximum wind receiving area.

Consistent with the above-mentioned principle of the fan hydraulic pitch change system, this fan hydraulic pitch change method has the same technical effect, and will not be repeated here.

Description of drawings

Fig. 1 is a structural block diagram of a specific embodiment of the fan hydraulic pitch system provided by the present invention;

Fig. 2 is the schematic diagram of the principle of the hydraulic system in Fig. 1;

Fig. 3 shows the schematic diagram of the connection structure between the bidirectional hydraulic motor and the transmission device of the hydraulic system in the specific embodiment;

Fig. 4 is a flow chart of a specific embodiment of the method for hydraulically changing the pitch of a fan provided by the present invention.

In the picture:

Hydraulic system 10, two-way hydraulic motor 11, hydraulic pump 12, first relief valve 13, second relief valve 14, reversing valve 15, oil tank 16;

Transmission device 20, bidirectional reducer 21, transmission member 22, pitch bearing 23;

Blade 30.

detailed description

In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Please refer to FIG. 1 , which is a structural block diagram of a specific embodiment of a fan hydraulic pitch system provided by the present invention.

For pitch fans, each blade has a relatively independent pitch drive system.

The fan hydraulic pitch system provided in this embodiment includes the transmission devices 20 correspondingly connected with the blades 30 of the fan; it also includes the hydraulic system 10 power-connected with the transmission devices 20, and the limit position consistent with the number of the blades 30 components; the pressure of the hydraulic system 10 is a constant value, so that the blade 30 realizes real-time pitching through the balance trend of the current wind load and the pressure of the hydraulic system 10; The wind load received at the position of the wind area; the limit position where the limiting component can limit the rotation of the blade 30 is the position of the maximum wind area.

As above, in this solution, the blade 30 is power-connected with the hydraulic system 10 through the transmission device 20, and the pressure of the hydraulic system 10 is a constant value, which makes the blade 30 maintain the maximum wind receiving area position at the full wind speed of the unit. And the corresponding position is provided with a limiting part to limit the extreme position of the blade 30 rotation; that is to say, the force transmitted to the blade 30 by the hydraulic system 10 is the same as that received by the blade 30 at the position of the maximum wind receiving area when the unit is at full wind speed. In this way, when the wind speed changes, the wind load on the blade 30 changes accordingly, while the force transmitted from the hydraulic system 10 to the blade 30 remains constant. Under the action of the difference between the two, the blade 30 can automatically move toward the Rotate and change the pitch in the direction of small wind area or large wind receiving area, so as to realize the real-time pitch change of the blade 30 automatically adapting to the wind condition, as follows:

The initial wind speed is small (less than the full wind speed), and the blade 30 is at the position of the maximum wind receiving area. When the wind speed increases (greater than the full wind speed), the wind load on the blade 30 becomes larger, which is greater than the force transmitted to the blade 30 by the hydraulic system 10 The blade 30 overcomes the hydraulic energy of the hydraulic system 10 to change the pitch to the direction of the small wind receiving area. Since the blade 30 rotates and changes the pitch according to the difference between the wind load and the hydraulic pressure, it can automatically adapt to the wind condition and change the pitch, and the response speed is fast. It can avoid component damage and unit failure caused by abnormal load on the blade 30 and related components due to the increased wind load in the prior art;

The initial wind speed is relatively high (greater than the full wind speed), and the blade 30 is in a position where the wind receiving area is small. The hydraulic energy of the hydraulic system 10 is converted into mechanical energy output, and the blade 30 is pitched to the maximum wind receiving area through the transmission device 20. After the blade 30 rotates to the maximum wind receiving area, it stops under the limit action of the limit member. , to avoid waste of wind energy.

Please refer to FIG. 2 and FIG. 3 together. FIG. 2 is a schematic diagram of the principle of the hydraulic system in FIG. 1; FIG. 3 shows a schematic diagram of the connection structure of the bidirectional hydraulic motor and the transmission device in the hydraulic system in a specific embodiment.

For ease of description, the fan has three blades 30 as an example below. It can be understood that the number of blades 30 of the fan can be other, and the number of blades 30 does not limit the protection scope of the present application.

The hydraulic system 10 includes three bidirectional hydraulic motors 11 , the power output ends of each hydraulic motor 11 are connected to the corresponding transmission device 20 , and the two oil ports of the bidirectional hydraulic motors 11 communicate with the system pressure oil circuit and the oil return circuit respectively.

The hydraulic energy of the hydraulic system 10 is converted into mechanical energy by the bidirectional hydraulic motor 11 , and transmitted to the blade 30 by the transmission device 20 .

In a specific solution, the hydraulic motor 11 is driven by a hydraulic pump 12 . In the solution shown in FIG. 2 , three hydraulic motors 11 are driven by the same hydraulic pump 12 to simplify the structure of the hydraulic system 10 .

The oil inlet of the hydraulic pump 12 communicates with the oil tank 16, and the oil outlet communicates with the system pressure oil circuit.

Specifically, the hydraulic pump 12 may preferably be a variable displacement pump, so that when the hydraulic system 10 keeps the position of the vane 30 constant, the flow rate of the hydraulic system 10 is minimum and the pressure is constant, so as to reduce power consumption.

Specifically, in order to keep the pressure of the system pressure oil circuit constant, a first overflow valve 13 communicated with the oil tank 16 can be installed at the oil outlet of the hydraulic pump 12, and the pressure of the hydraulic system can be adjusted through the set pressure of the first overflow valve 13. 10 pressure and keep it constant.

A second relief valve 14 can also be provided between the oil return circuit and the oil tank 16 at the same time, and the hydraulic system 10 can be maintained at a constant pressure through matching settings of the first relief valve 13 and the second relief valve 14 .

In a specific solution, the transmission device 20 includes a pitch bearing 23 connected to the blade 30 and a transmission member 22 connected to the pitch bearing 23 , wherein the transmission member 22 is connected to the power output end of the bidirectional hydraulic motor 11 .

Wherein, the transmission member 22 is connected to the power output end of the hydraulic motor 11 through a two-way speed reducer, and the two-way speed reducer 21 can be set to match the speed and transmit torque.

Specifically, the transmission member 22 may be in the form of a toothed belt or in the form of a gear. Correspondingly, the connection structure between the transmission member 22 and the bidirectional reducer 21 can be adjusted according to the specific form of the transmission member 22 .

The working process of the fan hydraulic pitch system is described below with a specific application.

Assuming that the wind speed is 10m/s, which is the full wind speed of the unit, when the wind speed is 10m/s, the blade 30 is at the maximum wind receiving area, and the unit is at full power. Correspondingly, the constant pressure of the hydraulic system 10 makes the hydraulic system 10 transmit to the blade 30 The force is balanced with the wind load that the blade 30 is subjected to at this time.

When the wind speed changes to 15m/s, which is greater than the full wind speed, and the wind load on the blade 30 is greater than the full wind load, the hydraulic system 10 transmits the force to the blade 30 through the bidirectional reducer 21, the transmission member 22 and the pitch bearing 23. When the force on the blade 30 is transmitted to the transmission member 22 through the pitch bearing 23, it will drive the output end of the transmission member 22 to rotate, and at the same time, the hydraulic system 10 overflows from the system pressure oil circuit through the first overflow valve 13, and the blade 30 is directed toward the wind When the pitch is changed in a small area, when the blade 30 adapts to a certain angle, and the wind load on the blade 30 is equal to the force transmitted to the blade 30 by the hydraulic system 10, the hydraulic system 10 stops overflowing, and the unit is still at full power , the pressure of the hydraulic system 10 remains constant during this process.

When the wind speed changes to 5m/s and the wind load on the blade 30 is less than full, the hydraulic system 10 transmits the force to the blade 30 through the two-way reducer 21, the transmission member 22 and the pitch bearing 23, so the hydraulic system 10 is The pressure is constant, and the two-way reducer 21 is driven by the two-way hydraulic motor 11, and the output torque is greater than the force of the transmission member 22 pulling the blade 30, so that the blade 30 will change pitch accordingly, until the blade 30 is at the position of the maximum wind receiving area, and is limited Stop after part limit.

As above, the fan hydraulic pitch system realizes the real-time pitch adjustment of the blades 30 automatically adapting to the wind conditions through the balance trend of the pressure of the hydraulic system 10 and the wind load on the blades 30 .

In addition, a reversing valve 15 can also be set between the system pressure oil circuit and the oil return circuit of the hydraulic system 10, and the reversing valve 15 is used to control the connection between the two oil ports of the hydraulic motor 11 and the system pressure oil circuit or the oil return circuit. The oil circuit is connected, and the setting of the reversing valve 15 can facilitate maintenance personnel to carry out maintenance to the unit.

As shown in Figure 2, when the fan is working normally, the reversing valve 15 remains in the left position, its first working oil port A communicates with the left oil port of the two-way hydraulic motor 11, and its second working oil port B communicates with the left oil port of the two-way hydraulic motor 11. The right oil port is connected.

In a specific solution, the limiting component can be arranged on the pitch bearing 23, or it can also be arranged at other positions, as long as the limit position of the blade 30 rotation can be limited to the position of the maximum wind receiving area, the limiting component can specifically be Limit stop.

In addition to the above fan hydraulic pitch change system, the present invention also provides a fan hydraulic pitch change method.

Please refer to Fig. 4, Fig. 4 is the flow chart of a specific embodiment of the fan hydraulic pitch method provided by the present invention; Under the wind speed, the wind load on the blade when it is at the position of the maximum wind receiving area, that is to say, when the unit is at full wind speed, the blade can be kept at the position of the maximum wind receiving area under the balance of wind load and constant hydraulic pressure ; The blades are pitched in real time according to the balance trend of the current wind load and the constant hydraulic pressure, and the extreme position of the blade rotation is the position of the maximum wind receiving area.

Specifically, the provision of constant hydraulic pressure can be provided by the aforementioned hydraulic system; the limit position of blade rotation can be realized by setting the aforementioned limiting components.

Consistent with the principle of the above-mentioned fan hydraulic pitch system, this method can also achieve the same technical effect, and will not be repeated here.

The fan hydraulic pitch control system and method provided by the present invention have been introduced in detail above. In this paper, specific examples are used to illustrate the principle and implementation of the present invention, and the descriptions of the above embodiments are only used to help understand the method and core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (10)

1. The fan hydraulic pitch system, including each transmission device (20) correspondingly connected to each blade (30) of the fan; it is characterized in that it also includes a hydraulic system (10) that is power-connected to each of the transmission devices (20) , and a limit part consistent with the number of the blades (30); the pressure of the hydraulic system (10) is a constant value, so that the blades (30) pass through the current wind load and the hydraulic system (10) The balance trend of the pressure realizes real-time pitch change; The constant value is the wind load received by the unit when the blade (30) is kept at the position of the maximum wind receiving area under the full wind speed; Describe the position of the maximum wind area. 2. The fan hydraulic pitch system according to claim 1, characterized in that, the hydraulic system (10) includes two-way hydraulic motors (11) in the same number as the transmission device (20), and each of the two-way hydraulic motors (11) The power output end of the motor (11) is connected with the corresponding transmission device (20); the two oil ports of the two-way hydraulic motor (11) communicate with the system pressure oil circuit and the oil return circuit respectively. 3. The fan hydraulic pitch system according to claim 2, characterized in that, the hydraulic system (10) also includes a hydraulic pump (12) that drives each of the two-way hydraulic motors (11) to work, and the hydraulic pump The oil outlet of (12) is also communicated with the fuel tank (16) through the first relief valve (13). 4. The fan hydraulic pitch system according to claim 3, characterized in that, the hydraulic system (10) further comprises a reversing valve (15), and the reversing valve (15) is used to control the two-way hydraulic The two oil ports of the motor (11) communicate with the system pressure oil circuit or the oil return circuit respectively. 5. The fan hydraulic pitch system according to claim 3, characterized in that, a second overflow valve (14) is further provided between the oil return circuit and the oil tank (16). 6. The fan hydraulic pitch system according to claim 3, characterized in that the hydraulic pump (12) is a variable displacement pump. 7. The fan hydraulic pitch system according to any one of claims 2-6, characterized in that, the transmission device (20) includes a pitch bearing (23) connected to the blade (30) and connected to the The transmission member (22) connected to the pitch bearing (23), the transmission member (22) is connected to the power output end of the bidirectional hydraulic motor (11). 8. The fan hydraulic pitch system according to claim 7, characterized in that the transmission member (22) is connected to the power output end of the bidirectional hydraulic motor (11) through a bidirectional reducer (21). 9. The fan hydraulic pitch system according to claim 7, characterized in that, the transmission member (22) is a toothed belt or a gear. 10. The hydraulic pitch change method of a fan, characterized in that the method includes: providing a constant hydraulic pressure to the blades of the fan, the size of the constant hydraulic pressure being that the unit is at full wind speed, and the blades are at the maximum wind receiving area The magnitude of the wind load received at the position; the blades are pitched in real time according to the balance trend of the current wind load and the constant hydraulic pressure, wherein the extreme position of the blade rotation is the position of the maximum wind receiving area.