WO2009025420A1

WO2009025420A1 - Wind turbine system using fluid torque converter

Info

Publication number: WO2009025420A1
Application number: PCT/KR2007/005593
Authority: WO
Inventors: Dong Yong Kim
Original assignee: Dong Yong Kim
Priority date: 2007-08-21
Filing date: 2007-11-07
Publication date: 2009-02-26
Also published as: KR100832053B1

Abstract

The present invention relates to a wind turbine system in which a generator is installed on the ground instead of a nacelle, so that rotation power of a rotor shaft of a blade is transmitted to a vertical shaft connected to a generator by using a torque converter for converting torque into rotation power, hydraulic pressure, and rotation power in the stated order. The first torque converter is mounted to the blade rotor shaft in the nacelle, that is, the upper structure of the wind turbine system, and the hydraulic hose is connected to the first torque converter to thereby transmit torque to the second torque converter mounted in a lower end portion of a tower. At this time, the second torque converter converts the torque into rotation power to thereby drive the generator.

Description

WIND TURBINE SYSTEM USING FLUID TORQUE

CONVERTER

Technical Field

[1] The present invention relates to a vertical wind turbine system, and more particularly to a vertical wind turbine system, which enables power to be transmitted at a relatively long distance through a fluid torque converter by installing a generator to be installed either in a middle portion of a tower or on the ground, so that superlightness of an upper structure of the wind turbine system where a blade is mounted can be realized, thereby facilitating accurate wind direction tracking, reducing the installation cost due to a reduced weight of the structure, and improving stability. Background Art

[2] In general, a wind turbine system enables a blade to be rotated using aerodynamic characteristics of the kinetic energy of the air flow to thereby acquire mechanical energy, and then further enables a generator to be rotated by the acquired mechanical energy to thereby acquire electricity. The wind turbine system is classified into a horizontal type, a vertical type and a united type of the horizontal type and the vertical type according to a direction of a shaft where the blade is installed. The wind turbine system provides economical advantages in terms of the installation cost and installation area in comparison with an atomic energy generator, a hydroelectric power generator, and a thermal power generator, and also does not cause environmental pollution.

[3] FIG. 1 is a schematic view illustrating a conventional wind turbine system. As illustrated in FIG. 1, the conventional horizontal wind turbine system includes a structure 1 installed to have a height suitable for exposure of the wind, a blade 2 rotatably mounted above the structure 1, a gear box 3 for transmitting rotation power acquired by increasing a rotation speed of a rotation shaft of the blade 2, and a generator 4 for converting the increased rotation power through the gear box 3 into electric power.

[4] In the above-mentioned wind turbine system, when the blade 2 is rotated by the wind, the rotation power of the blade 2 is increased by the gear box 3. The generator 4 generates electric power by the rotation power, and the generated electric power is applied to an electrical storage device, etc., or directly to a consumer.

[5] However, even though the conventional horizontal wind turbine system advantageously has a superior transmission efficiency due to a relatively shorter transmission path of rotation torque reaching from the blade 2 to the generator 4, a structural problem arises in that since the gear box 3 and the generator 4 are mounted above the structure 1, the center of gravity of the structure 1 is deviated to an upper portion of the structure 1, thereby causing inconvenience in the cooling, and the maintenance and repair. Also, the horizontal wind turbine system has a problem in that the horizontal wind turbine system is difficult to be protected against overload of the generator 4 at the time of emergency caused due to strong wind and the like.

[6] Meanwhile, a conventional vertical wind turbine system is constructed such that torque generated in a rotor shaft of a blade is transmitted to a vertical generator via a bevel gear. The vertical wind turbine system considerably facilitates withdrawal and cooling of a power line, and the maintenance and repair. Also, the vertical wind turbine system achieves lightness of a nacelle because the generator is not mounted in a nacelle installed above the structure, facilitates the control of yaw, and prevents twist of the power line.

[7] However, the vertical wind turbine system has problems in that the torque transmission path reaching from the blade rotor to the generator is relatively longer than that of the horizontal wind turbine system, thereby deteriorating the transmission efficiency owing to increased power transmission loss, and there is a restriction in a length of the shaft because of the loss increase due to increase in the shaft length, even though free yaw characteristics are improved as a distance from a center shaft of a tower to the rotator blade is greater. Specifically, when the length of the shaft is as short as possible, the transmission efficiency becomes superior. Also, in the vertical wind turbine system, a high precision is required for fabricating of the bevel gear, etc., and a failure occurrence rate is relatively great. Disclosure of Invention

Technical Problem

[8] Accordingly, the present invention has been made in an effort to solve the above- mentioned problems occurring in the conventional art, and it is an object of the present invention to provide a wind turbine system, in which rotation power of a rotation shaft of a blade is transmitted to a vertical shaft by using a fluid torque converter to thereby drive a generator and peripheral equipments of the vertical shaft, thereby improving the efficiency and overcoming problems of a vertical wind turbine system.

[9] Also, another object of the present invention provides a wind turbine system in which the rotation power is transmitted by using the fluid torque converter, thereby realizing lightness of an upper structure of the wind turbine system. Technical Solution

[10] To achieve the above object, according to the invention, there is provided a wind turbine system in which a generator is installed on the ground instead of a nacelle, so that rotation power of a rotor shaft of a blade is transmitted to a vertical shaft connected to a generator by using a torque converter for converting torque into rotation power, hydraulic pressure, and rotation power in the stated order.

[11] The torque converter rotates a pump impeller of a first torque converter by the blade rotor shaft to thereby pressurize internal fluid of the nacelle. Next, a turbine impeller is rotated by the pressurized internal fluid while the pressurized internal fluid is passing a second torque converter, and a driven shaft of the turbine impeller is connected to a drive shaft of the generator to thereby transmit power by using a hydraulic hose disposed between the first torque converter and the second torque converter.

[12] Accordingly, the first torque converter is mounted to the blade rotor shaft in the nacelle, that is, the upper structure of the wind turbine system, and the hydraulic hose is connected to the first torque converter to thereby transmit torque to the second torque converter mounted in a lower end portion of a tower. At this time, the second torque converter converts the torque into rotation power to thereby drive the generator, and thus realizing superlightness of the nacelle.

[13] Also, the first torque converter is connectively mounted to the blade rotor shaft, and the torque is transmitted to the second torque converter via the hydraulic hose. As a result, a sufficient distance from a vertical center line of the tower to the blade may be maintained without a need for a relatively longer rotor shaft, and thus free yaw characteristics are improved.

[14] Also, according to the present invention, a flow rate adjusting means for adjusting the flow rate of the hydraulic hose is mounted adjacent to the first torque converter and the second torque converter, respectively, so that the flow rate between the first torque converter and the second torque converter can be controlled, thereby enabling acceleration/deceleration of the first torque converter and the second torque convert, and thus eliminating a need for a separate gear box.

[15] According to the present invention, the wind turbine system comprises a blade adapted to allow rotation torque to be generated from a rotor shaft by being rotated by wind power; a first torque converter connected to the rotor shaft of the blade and adapted to convert the rotation torque into a hydraulic pressure; a nacelle having the rotor shaft of the blade and the first torque converter mounted inside thereof so as to permit the blade to be rotatably mounted to the nacelle, and having an upper fin and a lower fin mounted thereon so as to permit a yaw operation of the nacelle to be performed according to the direction of wind movement; a tower constructed such that the lower fin of the nacelle is freely rotatably mounted at an upper portion of the tower, the tower being adapted to support the wind turbine system; a generator mounted at the bottom of the inside of the tower; a second torque converter mounted above the generator, the second torque converter being adapted to receive the hydraulic pressure generated from the first torque converter, convert the received hydraulic pressure into rotation torque, and transmit the converted rotation torque to a drive shaft of the generator; a hydraulic hose adapted to transmit the hydraulic pressure and achieve fluid reduction between the first torque converter and the second torque converter; and a slip-type fluid withdrawal tap mounted at a connection portion between the nacelle and the tower, and adapted to interconnect the hydraulic hoses disposed between the first torque converter and the second torque converter in such a manner as to rotatably confine the hydraulic hoses therein, thereby preventing the hydraulic hose from being rotated or twisted.

[16] Also, according to the present invention, the wind turbine system further comprises a flow rate-adjusting valve mounted adjacent to the first torque converter and the second torque converter and adapted, respectively, for adjusting a flow rate of the hydraulic hose, thereby controlling acceleration and deceleration of the first torque converter and the second torque converter.

Advantageous Effects

[17] As described above, according to the present invention, a generator is fixedly installed either to a vertical shaft or on the ground, thereby facilitating power generating equipment installation, withdrawal of a power line and cooling equipment installation, maintenance/repair, and the like. Also, since only first torque converter is mounted inside the nacelle, the size of the nacelle is reduced and lightness of the nacelle is realized, and thus, a yaw operation is performed by a fin mounted on the nacelle even in a relatively lower wind speed. Also, superlightness of the nacelle is realized, thereby reducing the cost spent for the design and manufacture of the tower, and improving the stability against a wind pressure and a load of the nacelle.

[18] Further, in the case of a conventional horizontal wind turbine system, power lines withdrawn from a generator are twisted. However, in the present invention, the twist phenomenon of the power lines is structurally prevented from occurring by a slip-type fluid withdrawal tap. Also, the acceleration/deceleration of the first torque converter and the second torque converter are controllable only by using the fluid torque converter, thereby eliminating a need for a separate gear box. Also, the rotor shaft and the generator shaft need not to coincide with each other, thereby improving convenience of the construction, and a sufficient distance between a vertical center line of the tower and the blade is secured, thereby improving free yaw characteristics.

[19] In addition, automobile waste oil may be used as lubricant required for a fluid torque converter, thereby contributing to recycling of resources. Brief Description of the Drawings

[20] Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[21] FIG. 1 is a schematic view illustrating a conventional wind turbine system;

[22] FIG. 2 is a side view illustrating a configuration of a wind turbine system according to the present invention;

[23] FIG. 3 is a photo showing an appearance of a wind turbine system according to the present invention;

[24] FIG. 4 is a schematic view illustrating acceleration/deceleration control of a wind turbine system according to the present invention; and

[25] FIG. 5 is a side view illustrating improvement of free yaw characteristics of a wind turbine system according to the present invention. Best Mode for Carrying Out the Invention

[26] Hereinafter, a preferred embodiment of the invention will be described in detail with reference to the appended drawings.

[27] FIG. 2 is a side view illustrating a configuration of a wind turbine system according to the present invention.

[28] As showin in FIG. 2, a wind turbine system comprises a blade 10 mounted for generating rotation torque in a rotor shaft 11 by being rotated by wind power; a first torque converter 30 connected to the rotor shaft 11 of the blade 10 and adapted to convert the rotation torque into a hydraulic pressure; a nacelle 20 having the rotor shaft 11 of the blade 10 and the first torque converter 39 mounted inside thereof so as to permit the blade to be rotatably mounted to the nacelle, and having an upper fin 21 and a lower fin 22 mounted thereon so as to permit a yaw operation of the nacelle 20 to be performed according to the direction of wind movement; a tower 40 constructed such that the lower fin 22 of the nacelle 20 is freely rotatably mounted at an upper portion of the tower so that the yaw operation of the nacelle 20 is performed according to the wind direction, the tower being adapted to support the wind turbine system; a generator 70 mounted at the bottom of the inside of the tower 40; a second torque converter 60 mounted above the generator 70, the second torque converter being adapted to receive the hydraulic pressure generated from the first torque converter 30, convert the received hydraulic pressure into rotation torque, and transmit the converted rotation torque to a drive shaft of the generator 70; a hydraulic hose 50 adapted to transmit the hydraulic pressure and achieve fluid reduction between the first torque converter 30 and the second torque converter 60; and a slip-type fluid withdrawal tap 80 mounted at a connection portion between the nacelle 20 and the tower 40, and adapted to interconnect the hydraulic hoses 50 disposed between the first torque converter and the second torque converter such a manner as to rotatably confine the hydraulic hoses therein, thereby preventing the hydraulic hose 50 from being rotated or twisted.

[29] FIG. 4 is a schematic view illustrating acceleration/deceleration control of a wind turbine system according to the present invention. As shown in FIG. 4, the wind turbine system further comprises flow rate-adjusting valves 31 and 61 for adjusting a flow rate of the hydraulic hose 50, thereby controlling acceleration and deceleration of the first and second torque converters 30 and 60.

[30] As described above, an operation of the wind turbine system will be hereinafter described in detail.

[31] The nacelle 20 is installed above the tower 40, and the upper and lower fins 21 and

22 are installed inside the nacelle 20. Here, the upper fin 21 is a wing for allowing a yaw operation of the nacelle 20 to be performed according to a wind direction, and the lower fin 22 is a structure for the yaw operation to be freely rotated with respect to the tower 40. A well known technique may be used for the structure for the yaw operation, and thus detailed description thereof will be omitted herein.

[32] The blade 10 is rotatably installed to a side end of the nacelle 20 in such a manner that the rotator shaft 11 of the blade 10 is installed in an inner space of the nacelle 20, thereby transmitting rotation torque to the first torque converter 30. The second torque converter 60 is installed at the bottom of the inside of the tower 40, and the generator 70 is connected to the second torque converter 60. The hydraulic hose 50 is disposed between the first torque converter 30 and the second torque converter 60.

[33] When the blade 10 is rotated by wind power, the rotation power of the rotor shaft 11 enables a pump impeller (not shown) of the first torque converter 30 to be rotated, and internal fluid is pressurized by the pump impeller. That is, torque is converted by a hydraulic pressure with which the rotation torque pressurizes the fluid.

[34] The rotation power is converted into the hydraulic pressure by the first torque converter 30, and the converted hydraulic pressure is transmitted to the second torque converter 60 via a hydraulic transmission hose 51 of the hydraulic hose 50. In the second torque converter 60, a turbine impeller (not shown) is rotated by the fluid transmitted via the hydraulic hose 50, and the fluid passing the turbine impeller is circulated to the first torque converter 30 via a hydraulic recovery hose 52.

[35] The rotation force generated due to the rotation of the turbine impeller of the second torque converter 60 is transmitted to a drive shaft of the generator 70 to thereby drive the generator 70, and thus producing electricity.

[36] Thus, according to the present invention, since the first and second torque converter

30 and 60 are used as a means for transmitting the rotation power of the blade 10 to the generator 70, and only the hydraulic hose 50 is installed between the first and second torque converter 30 and 60, a complicate bevel gear is not required to be used.

[37] Meanwhile, the slip-type fluid withdrawal tap 80 is mounted between the nacelle 20 and the tower 40, thereby preventing the hydraulic hose 50 from being rotated or twisted by a free yaw movement. More specifically, the slip-type fluid withdrawal tap 80 is mounted between the hydraulic hose connected to the first torque converter 30 and the hydraulic hose connected to the second torque converter 60 so as to interconnect the hydraulic hoses in such a manner as to rotatably confine the hydraulic hoses therein, so that the hydraulic hose 50 is prevented from being rotated or twisted even when the free yaw movement is generated. Here, the free yaw movement is generated such that the nacelle 20 follows a direction of the wind by the upper fin 21 operation in accordance with the direction of the wind, and the blade 10 always faces the direction of the wind while the lower fin 22 is being freely rotated with respect to the tower 40.

[38] Also, as shown in FIG. 4, the flow rate-adjusting valves 31 and 61 for adjusting a flow rate of the hydraulic hose 50 are mounted adjacent to the first torque converter 30 and the second torque converter 60, respectively. The flow rate of the hydraulic hose 50 is adjusted by the flow rate-adjusting valves 31 and 61, so that acceleration and deceleration of the first torque converter and the second torque converter can be freely controlled, thereby eliminating a need for a separate acceleration/deceleration gear box.

[39] FIG. 5 is a side view illustrating improvement of free yaw characteristics of a wind turbine system according to the present invention. As shown in FIG. 5, when it is assumed that a distance from a position Al of a vertical center line of the tower 40 to a position Bl of the blade 10 is 'L', a free yaw angle θl of the blade 10 when the 'L' is 'Ll 'of a relatively shorter distance is greater than a free yaw angle Θ2 of the blade 10 when the 'L'is 'L2'of a relatively longer distance. That is, when Ll is greater than L2, θ 1 is greater than Θ2, so that a free yaw characteristic of L2 is improved relatively more than that of Ll.

[40] When the distance L between the vertical center line of the tower 40 and the blade 10 is sufficiently maintained, the free yaw characteristic is more improved. However, in a conventional vertical wind turbine system performed by a mechanical power transmission method, since the rotor shaft of the blade has a relatively greater length, an overall weight of the nacelle 20 disadvantageously becomes greater, and a shaft loss of the blade is undesirably increased. Conversely, in the present invention, since a fluid torque converter scheme is used, only the hydraulic hose which is not rotated is connected instead of the shaft. As a result, the distance L between the center line of the tower and the blade is sufficiently maintained without a power loss of the shaft, and lightness of the nacelle is realized.

[41] While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.

Claims

[1] A wind turbine system, comprising: a blade adapted to allow rotation torque to be generated from a rotor shaft by being rotated by wind power; a first torque converter connected to the rotor shaft of the blade and adapted to convert the rotation torque into a hydraulic pressure; a nacelle having the rotor shaft of the blade and the first torque converter mounted inside thereof so as to permit the blade to be rotatably mounted to the nacelle, and having an upper fin and a lower fin mounted thereon so as to permit a yaw operation of the nacelle to be performed according to the direction of wind movement; a tower constructed such that the lower fin of the nacelle is freely rotatably mounted at an upper portion of the tower so that the yaw operation of the nacelle is performed according to the wind direction, the tower being adapted to support the wind turbine system; a generator mounted at the bottom of the inside of the tower; a second torque converter mounted above the generator, the second torque converter being adapted to receive the hydraulic pressure generated from the first torque converter, convert the received hydraulic pressure into rotation torque, and transmit the converted rotation torque to a drive shaft of the generator; a hydraulic hose adapted to transmit the hydraulic pressure and achieve fluid reduction between the first torque converter and the second torque converter; and a slip-type fluid withdrawal tap mounted at a connection portion between the nacelle and the tower, and adapted to interconnect the hydraulic hoses disposed between the first torque converter and the second torque converter in such a manner as to rotatably confine the hydraulic hoses therein, thereby preventing the hydraulic hose from being rotated or twisted.

[2] The wind turbine system according to claim 1, further comprising a flow rate- adjusting valve mounted adjacent to the first torque converter and the second torque converter, respectively, and adapted to adjust a flow rate of the hydraulic hose, thereby controlling acceleration and deceleration of the first torque converter and the second torque converter.