WO2017110298A1

WO2017110298A1 - Windmill system and wind farm

Info

Publication number: WO2017110298A1
Application number: PCT/JP2016/083625
Authority: WO
Inventors: 向井　寛
Original assignee: 株式会社日立製作所
Priority date: 2015-12-25
Filing date: 2016-11-14
Publication date: 2017-06-29
Also published as: JP2019060237A

Abstract

The objective is to provide a windmill system and a wind farm that take into account an improvement in the wind speed with respect to the rotor. This horizontal-axis-type windmill system is equipped with a rotor that rotates when wind is received, a nacelle that enables the rotor to rotate, and a tower 3, and is characterized by being equipped with drag bodies 9 which block wind moving from the outside of the windmill system toward the rotor, the drag bodies 9 being arranged at a position lower than the lower end of the rotor, and at least of a portion of the drag bodies being arranged between the tower 3 and a vertical axis line that includes the position farthest from the tower 3 in the rotational plane of the rotor.

Description

Windmill system or wind farm

The present invention relates to a windmill system or a wind farm.

Wind turbine systems have been put into practical use in recent years, and are becoming widespread all over the world as the fourth power generation means following thermal power, hydropower, and nuclear power. A windmill system is a device that receives kinetic energy of airflow with a blade, converts it into rotational energy of a rotor, and further generates electrical energy by a generator. Since the power generation amount of the system increases in proportion to the third power of the wind speed, the power generation amount increases remarkably even if the wind speed reaching the blade is slightly increased. For this reason, some ideas have been proposed to increase the amount of power generation by actively guiding the airflow around the windmill to the blade.

For example, the wind diverter disclosed in Patent Document 1 is a flow around the ground surface that does not contribute to conventional power generation by constructing a fixed height base that surrounds the windmill tower and forming a slope from the ground surface to the top of the base. The purpose of this is to increase the amount of power generation by speeding up the airflow that drives the blades by guiding them to the vicinity of the blades. The wind diverter has a slope and a flat part to guide the airflow upstream of the windmill system to the vicinity of the blades, and further includes a guide vane to prevent a lateral deviation of the airflow.

Moreover, the windmill described in Patent Document 2 includes a wind direction converter below the support column, and converts the wind blown toward the support column into an upward flow along the support column by a plurality of guide vanes extending radially from the tower at regular intervals. . It is described that a vertical axis wind turbine rotates a generator by receiving an upward flow. Accordingly, it is an object of the present invention to effectively suppress the generated power caused by a decrease in the wind force of the wind acting on the windmill as compared with the conventional technology that generates power only with the rotational power of the windmill.

Special table 2011-522160 gazette JP 2014-15899 A

However, with regard to the wind diverter of Patent Document 1, only the induction of airflow to the lower side of the rotor is limited. Therefore, the air volume does not increase with respect to the entire rotor rotation surface, and it is difficult to contribute from the viewpoint of improving the power generation amount.

Further, in the wind direction changer described in Patent Document 2, the airflow is raised vertically from the lower side of the rotor, and no vertical airflow is induced with respect to the rotating surface of the rotor. Furthermore, the second generator is provided between the wind direction changer and the blade, and it is difficult to contribute to an increase in the wind speed to the blade. In addition, since the blade and the wind direction changer are provided, it is difficult to contribute to an increase in the wind speed to the blade, and it is difficult to contribute to an improvement in power generation amount.

Therefore, an object of the present invention is to provide a windmill system or a wind farm that takes into account the improvement in the amount of power generation.

In order to solve the above problems, a windmill system according to the present invention is a horizontal axis type windmill system including a rotor that rotates by receiving wind, a nacelle that allows the rotor to rotate, and a tower, the windmill system comprising: A resistor that blocks wind from the outside of the system toward the rotor, the resistor being disposed at a position lower than the lower end of the rotor, and including a position farthest from the tower in the rotation plane of the rotor At least a portion is disposed between the axis and the tower.

According to the present invention, it is possible to provide a windmill system or a wind farm that takes into account the improvement in power generation.

Typical schematic configuration diagram showing a wind turbine system of a comparative example Typical schematic configuration diagram showing a wind turbine system of a comparative example The block diagram (oblique projection figure) of the windmill system concerning 1st Example of this invention The block diagram which looked at the windmill system concerning 1st Example of this invention from the side. Explanatory drawing expressing the flow of the air current around the wind turbine system according to the first embodiment of the present invention The block diagram which looked at the windmill system concerning 1st Example of this invention from right above Arrangement example of resistor 9 Flow analysis result showing the effect of the wind turbine system according to the first embodiment of the present invention The figure showing the relationship between the wind speed of the windmill system concerning 1st Example of this invention, and output electric power. One configuration example of the resistor 9 according to the second embodiment (variable fluid resistance: maximum) One configuration example of the resistor 9 according to the second embodiment (variable fluid resistance: minimum) One configuration example of the resistor 9 according to the third embodiment (variable fluid resistance: maximum) One configuration example of the resistor 9 according to the third embodiment (variable fluid resistance: minimum) One Example of a Floating Windmill According to the Present Invention According to Example 4 One Example of a Floating Windmill According to the Present Invention According to Example 4 Example of arrangement of resistor 9 according to example 5 FIG. 10 is an embodiment of the upwind wind turbine according to the fifth embodiment of the present invention.

(Comparative example)
FIG. 1 shows a specific structure of a windmill system having a truncated cone 21 below the tower 3 of the windmill. The windmill system in FIG. 1 is a downwind type windmill system in which a rotor faces downwind. The blade 1 is moved by receiving an air current, and a set of three blades constitutes a rotor. The nacelle 2 to which the rotor is attached includes a speed increaser and a generator inside, and the kinetic energy of the blade 1 is finally converted into electric energy by the generator. The tower 3 is installed on the ground, for example, and supports the load of the rotor and the nacelle 2. Here, the tower 3 supports the nacelle 3 in a rotatable manner in accordance with the wind direction, and can increase the efficiency of power generation. There is a flat portion 4 on the top of the truncated cone 21 in this comparative example. The truncated cone 21 is located below the tower 3, and the slope 5 of the truncated cone 21 connects the flat portion 4 and the ground with a slope. With this structure, the airflow in the vicinity of the ground surface of the natural wind 7 is guided to the upper flat portion 4 through the slope 5 of the truncated cone 21, but is only guided to the airflow to the lower side of the rotor.

FIG. 2 is an example of a windmill system provided with guide vanes 6 for guiding the wind to the tower 3 of the windmill system. Unlike FIG. 1, the guide vanes 6 are provided on the slope 5 of the truncated cone 21. The guide blade 6 is for inducing an air flow. The guide vanes 6 can prevent the lateral deviation of the airflow. The natural wind 7 is changed by the guide vanes 6 and the truncated cone 21 into an air flow 8 that is guided upward. The guide vanes 6 can be taken in and out of the truncated cone 21, and the upstream guide vanes 6 can be taken out according to the wind direction so that the air flow can be guided to the lower side of the rotor more efficiently than the truncated cone 21 shown in FIG. However, the configuration of FIG. 2 is also limited to the induction of the airflow to the lower side of the rotor.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the windmill system in a present Example is a downwind type windmill system which a rotor faces leeward.

In this embodiment, the operation of the wind turbine system of the present invention will be described with reference to FIGS. The windmill system shown in FIG. 3 is a horizontal axis windmill in which the rotor rotates approximately in a horizontal plane, and the blade 1 moves by receiving an airflow to form a rotor in a set of three. The nacelle 2 includes a speed increaser and a generator, and has a function of finally converting the kinetic energy of the blade 1 into electric energy by the generator. The tower 3 is installed on the ground, for example, and supports the load of the rotor and the nacelle 2. Here, the tower 3 supports the nacelle 2 in a rotatable manner in accordance with the wind direction, and can increase the efficiency of power generation.

The resistor 9 according to the present embodiment is a flat object made of a rigid body such as concrete or steel, and a plurality of pieces (six in this embodiment) are arranged in the vertical vertical direction so as to surround the tower 3. Has been. By arranging in the vertical vertical direction, the effect of blocking the wind can be expected from any direction in the horizontal plane. FIG. 4 shows the height of the resistor 9. The height of the resistor 9 is determined by the height of the tower 3 and the size of the rotating surface of the rotor. Depending on the rotational position of the rotor and the height of the resistor 9, it is necessary to avoid a collision. In order to avoid a collision regardless of the position of the rotor, the top of the resistor 9 is located below the lowest end of the rotor. It is desirable to be located. In addition, it is desirable that at least a part of the resistor 9 is disposed at a position that is less than half the distance ΔD between the lower end of the rotor and the foundation that supports the wind turbine system.

Fig. 5 shows the movement of airflow around the windmill. In the present embodiment, the natural wind 7 is assumed to be an airflow that goes from the left front toward the right back. Among the natural winds 7, the wind 20 flowing near the ground flows over the resistor 9 while colliding with the resistor 9 and flows to the leeward side facing the rotor. At this time, when the wind 20 collides, the windward side of the resistor 9 becomes positive pressure (high pressure region). On the other hand, the leeward side of the resistor 9 has a negative pressure (low pressure region) compared to the leeward side of the resistor 9 due to the wind being blocked by the resistor 9. At that time, due to the influence of the resistor 9, a vortex 10 is generated on the downstream side of the wind 20, that is, on the back side of the resistor with respect to the wind direction. The wind speed of the wind 20 passing through the vicinity of the vortex 10 is increased by the generated vortex 10. Therefore, the effect of increasing the flow velocity with respect to the rotating surface of the rotor is obtained. Further, the negative pressure (low pressure region) generated by the resistor 9 also induces airflow passing above the rotor rotation surface to the rotor rotation surface, which contributes to an improvement in the amount of power generation. This is different from that shown in the comparative example described above. In other words, the resistor in the present embodiment is completely different from the guide member that changes the wind direction along its own shape. Further, no vertical axis wind turbine is provided between the resistor 9 and the rotor of the horizontal axis wind turbine, so that the increased wind speed directly hits the horizontal axis wind turbine.

Further, by surrounding the tower 3 radially, the resistor 9 forms a low-pressure region on the rear side of the rotor rotation surface with respect to the wind direction in any wind direction, and the nacelle 2 corresponds to the wind direction with respect to the tower 3. Even when rotating, the presence of the resistor 9 makes it possible to guide the accelerated wind to the rotor.

Furthermore, it is desirable that the resistors 9 are arranged symmetrically with respect to the tower 3. Accordingly, even when the nacelle 2 rotates with respect to the tower 3 in accordance with the wind direction, it is possible to guide the wind speed from the wind direction evenly to the left and right with respect to the rotation surface of the rotor.

Furthermore, it is desirable that at least a part of the resistor is arranged between the vertical axis including the position farthest from the tower 3 and the tower 3 in the rotation plane of the rotor as shown in FIG. Along with this, a negative pressure region can be provided behind the rotating surface of the rotor, and the contribution of wind accelerated by the resistor 9 to the rotor can be increased.

In this embodiment, it is not necessary to provide the truncated cone 21 or the like in the tower 3, and by providing the resistor 9, it is possible to easily increase the wind speed with respect to the rotor rotation surface.

Also, in the downwind type windmill system, since the rotor is located leeward than the tower 3, a dead water area (tower shadow) is generated in the downstream of the tower 3 with respect to the wind direction. Accordingly, when the rotor passes through the tower shadow, the wind speed differs between the tower shadow and a portion other than the tower shadow. Therefore, it is known that the fluid force acting on the blade fluctuates at the timing when the blade passes the tower shadow, and the fluctuating load on the rotor increases. As in the present embodiment, the resistor 9 is provided so as to be shifted from the vertical plane including the rotation axis of the rotor, and the partial resistor 9 is positioned to be shifted from the vertical plane including the rotation axis of the rotor. By being arranged, the wind speed can be supplemented to the tower shadow located behind the resistor 9 with respect to the wind direction, and the difference in wind speed between the tower shadow and a portion other than the tower shadow can be reduced. . Therefore, reliability and product life can be improved by reducing the fluctuating load on the rotor.

Another form of the resistor 9 in the downwind type windmill system will be described with reference to FIG. In this embodiment, the resistor 9 is arranged asymmetrically with respect to the tower 3 as viewed from the upstream side. Specifically, when viewed from above the tower 3, the resistor 9 is rotationally symmetric with respect to the tower 3 as a center. Is arranged. In the downwind type wind turbine shown in this embodiment, since the blade 1 exists on the downstream side of the tower 3, if the low speed region on the downstream side of the tower 3 is large, unsteady fluid force acting on the blade 1 increases. However, large fluctuations occur. The present embodiment is an example of the countermeasure, and the resistor 9 forms a vortex 10 on the downstream side, and a flow that circulates to the rear side of the tower due to an asymmetric effect. The generation of the low speed region on the side can be mitigated. In this embodiment, since the resistor 9 is arranged rotationally symmetrically with respect to the tower 3, no matter which direction the wind blows from any direction of 360 degrees in the horizontal plane, Since it functions to block the wind, it can compensate for the decrease in wind in the tower shadow.

Fig. 8 shows the results of evaluating the flow velocity around the wind turbine by numerical analysis. The left figure in FIG. 8 shows the case without the resistor 9, and the right figure shows the case with the resistor 9. In general, the speed of natural wind is zero on the surface of the earth, and increases exponentially toward the sky. A circle 22 represents the trajectory of the blade 1, the average flow velocity at the height of the nacelle 2 when the resistor 9 is not present is defined as V, and the velocity distribution at the rotor position is indicated by contour lines in the circle 22. . As it goes from bottom to top, the speed increases to 0.8V, 1.0V, and 1.2V. Further, on the downstream side of the tower 3, there is a tower shadow whose speed is extremely reduced. Comparing the effect of the presence or absence of the resistor 9, the contour lines of 0.8 V, 1.0 V, and 1.2 V move vertically downward when the resistor 9 is present. This is caused by the overall increase in the wind speed at the rotor rotation surface.

From the above results, the amount of power generation can be increased by installing the resistor 9 even under the same natural wind speed. FIG. 9 shows the rated output of the power generation amount at each wind speed between the present method in which the resistor 9 is installed and the conventional method in which the resistor 9 is not installed. When this method is adopted, an increase in output at a low wind speed can be confirmed as compared with the conventional method.

A second embodiment of the present invention will be described with reference to FIGS. FIG. 10 shows an example of the configuration of the resistor 9, which is an example in which the fluid resistance of the resistor 9 is made variable by a multi-blade structure. In this embodiment, the wing 12 has a horizontal axis (rod axis) for driving, and is a rectangular rigid body that is not deformed by wind force. In this embodiment, one resistor 9 is constituted by ten blades 12. The column 13 is a structure that supports the load of the wing 12 and is fixed to the ground, for example, and supports the wing 12 in a movable state. Therefore, the support column 13 has a drive mechanism 14 for driving (rotating) the horizontal axis of the blade 12. FIG. 10 shows a state in which the blades are vertically aligned. In this case, the airflow is blocked by the blades 9, and the fluid resistance by the resistor 9 is maximized. On the other hand, FIG. 11 shows a case where all the blades 12 are horizontally aligned by the drive mechanism 14. In this case, the airflow can freely pass between the blades, and the fluid resistance by the resistor 9 is minimized. That is, in this configuration, the fluid resistance can be freely adjusted by the drive mechanism 14. For example, there is a case where it is not desired to increase the flow velocity around the rotor during a storm such as a typhoon. In addition, in order to prevent the resistor 9 itself from being destroyed by the influence of the storm, it is assumed that the fluid resistance needs to be lowered, and it can be said that the present configuration capable of adjusting the wind receiving area is effective. In this embodiment, two struts 13 are provided. However, by integrating a strut on one side with the tower 3, a similar resistor can be configured with a single strut. Of course, the number and direction of the blades 12 and how to drive them are not limited to the example shown here.

A third embodiment of the present invention will be described with reference to FIGS. FIG. 12 shows an example of the configuration of the resistor 9, in which the resistor 9 is formed by the canvas 15. The canvas 15 is variable and also generates air resistance. The hanging member 16 of the canvas 15 is, for example, a wire rope. The canvas 15 is fixed in a state of being suspended at a plurality of locations by the suspension member 16. The support column 17 that supports the suspension member 16 is fixed to the ground, for example. The canvas 15 is also fixed to the support column 17 at one place or a plurality of places. FIG. 13 shows a state in which the canvas 15 is spread. At this time, the fluid resistance of the resistor 9 is maximized. FIG. 13 shows an example of a state in which the sail is folded. For example, there is a case where it is not desired to increase the flow velocity around the rotor during a storm such as a typhoon. Moreover, in order to prevent the resistor 9 itself from being destroyed by the influence of the storm, it is assumed that the fluid resistance needs to be lowered, and it can be said that this configuration is effective. In this embodiment, two struts 17 are provided, but by integrating the strut 17 on one side with the tower 3, the same resistor 9 can be configured with a single strut.

A fourth embodiment of the present invention will be described with reference to FIGS. FIG. 14 shows an example of application of the present invention to an offshore wind turbine. A floating body 18 is moored on the sea floor or the coast and supports the wind turbine. The resistor floating body 19 is anchored to the floating body 18 so as to surround the floating body 18 so as to maintain a distance from the floating body 18. Any of the forms shown in the above embodiments can be applied to the resistor 9. FIG. 15 shows another form of the resistor 9, which is an example in which the support 9 of the resistor floating body 19 is omitted for the purpose of reducing the manufacturing cost and the resistor 9 of the third embodiment is configured. Although the sail has a shape close to a triangle, the effect of inducing wind accelerated on the rotating surface of the rotor as in the first embodiment can be obtained.

A fifth embodiment of the present invention will be described with reference to FIG. The present embodiment is characterized in that the resistor 9 is arranged in a state of being separated from the tower 3 by a certain distance (having a gap between the resistor 9 and the tower 3). On the downstream side of the resistor 9 shown in the first embodiment, the flow velocity decreases, and is lowest particularly at the position of the tower 3 at the center of the resistor 9. If this low speed region is large, when constructing a wind farm in which a plurality of wind turbines are arranged, it is conceivable that the wind speed of the downstream wind turbine decreases due to the low speed region created by the upstream wind turbine and the power generation amount decreases. The present embodiment is an example of the countermeasure, and a gap is provided between the resistor 9 and the tower 3. As a result, a high-speed flow field passing through the gap is formed, and the influence of the low-speed region can be mitigated.

The embodiments of the present invention have been described above. However, the above-described embodiments are merely examples, and do not limit the present invention. For example, although not as much as a downwind type windmill system, an unsteady fluid force is generated on the blade 1 due to the tower shadow even in an upwind type windmill system in which the rotor is upstream of the tower 3 as shown in FIG. That is, the tower 3 having a fixed projection area with respect to the wind is located immediately downstream of the rotating blade 1, so that the flow of the wind in that portion is blocked, and the load on the blade 1 and the torque pulsation of the rotor are reduced. Can be a factor. The flow pattern changes in a direction to avoid the low speed region generated downstream of the resistor 9, and the flow velocity in the sky increases. Accordingly, it interferes with the upstream flow pattern, and the wind speed improvement effect on the rotor can be obtained even in an upwind wind turbine.

DESCRIPTION OF SYMBOLS 1 ... Blade 2 ... Rotor and nacelle 3 ... Tower 4 ... Flat part 5 of a truncated cone 5 ... Slope 6 of a truncated cone 6 ... Guide vane 7 of a truncated cone An arrow 8 schematically showing an arrow 9 showing an air flow in a truncated cone 9 an resistor 10 an arrow 11 schematically showing a vortex generated by the influence of the resistor An arrow 12 representing the flow toward the low pressure region generated by the vortex 12 ... the wing 13 ... the support 14 ... the drive mechanism 15 ... the canvas 16 ... the suspension mechanism 17 ... the support 18 ... -Floating body 19 ... Resistor floating body 20 ... Arrow 21 schematically showing airflow flowing near the ground 22 ... Frustum 22 ... Blade trajectory

Claims

A rotor that rotates in response to the wind;
A nacelle that allows the rotor to rotate;
A horizontal axis windmill system including a tower,
A resistor that blocks wind from the outside of the wind turbine system toward the rotor;
The resistor is disposed at a position lower than a lower end of the rotor, and at least a part of the resistor is disposed between a vertical axis including a position farthest from the tower in a rotation plane of the rotor and the tower. Windmill system.
The windmill system according to claim 1,
In the height direction, at least a part of the resistor is disposed at a position less than ½ of the distance between the lower end of the rotor and the foundation supporting the wind turbine system from the lower end of the rotor. A windmill system characterized by that.
It is a windmill system of Claim 2, Comprising:
The wind turbine system according to claim 1, wherein the resistor is formed in a vertical vertical direction.
The windmill system according to claim 2 or 3,
The wind turbine system according to claim 1, wherein the resistor has a changeable wind receiving area.
The windmill system according to claim 2 or 3,
The wind turbine system according to claim 1, wherein the resistor is a plate member.
It is a windmill system of Claim 4, Comprising:
Each of the plate members is supported by a rod shaft, and the wind turbine system includes a drive device that controls the rotation of the plate member around the rod shaft to vary the wind receiving area.
It is a windmill system of Claim 4, Comprising:
The wind turbine system according to claim 1, wherein the resistor is made of canvas.
It is a windmill system of Claim 4, Comprising:
The wind turbine system according to claim 1, wherein the resistor has a triangular shape with respect to a wind direction.
It is a windmill system of Claim 5, Comprising:
The wind turbine system according to claim 1, wherein the resistors are arranged radially with respect to the tower.
It is a windmill system of Claim 5, Comprising:
The said resistor is arrange | positioned rotationally symmetrically centering | focusing on the said tower, The windmill system characterized by the above-mentioned.
It is a windmill system of any one of Claims 5 thru | or 9, Comprising:
The said resistor is arrange | positioned axially symmetrically with respect to the said tower, The windmill system characterized by the above-mentioned.
The windmill system according to any one of claims 9 to 11,
The rotor is a downwind rotor that is disposed leeward during power generation operation,
In any horizontal direction, at least a part of the resistors are arranged so as to be located on the windward side of the rotor, and the part of the resistors includes a rotation axis of the rotor. A windmill system characterized by being arranged so as to be displaced from the surface.
The windmill system according to any one of claims 1 to 12,
A floating body that supports the resistor on water;
The wind turbine system, wherein the resistor is disposed on the floating body.
A wind farm comprising a plurality of wind turbine systems according to claim 1,
The wind farm characterized by the said resistor which each windmill system has arrange | positions away from the tower in the said windmill system.