JP2006299818A - Windmill blade, horizontal axis windmill, surface pressure measuring device and surface pressure measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent strength degradation of a blade in measuring surface pressure of the windmill blade and to facilitate maintenance of holes for pressure measurement. <P>SOLUTION: The blade for a horizontal axis windmill is divided into a plurality of divided blades along a longitudinal direction and a metal plate 13 of the same cross-sectional shape as a cross-sectional shape of the divided blades is interposed between the divided blades. A hollow portion 13b is formed inside the metal plate 13, the through holes 13c for pressure measurement are perforated through from a surface 13a to the hollow portion 13b of the metal plate 13 and an air pressure measuring device 20 is connected to each through hole 13c via a predetermined pipe 30. The pressure of air flowing into through each through hole 13c and each pipe 30 is measured by the air pressure measuring device 20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wind turbine blade, a horizontal axis wind turbine, a blade surface pressure measuring device, and a blade surface pressure measuring method.

  The performance of the horizontal axis wind turbine and the load acting on the horizontal axis wind turbine are largely determined by the aerodynamic forces (lift and drag) acting on the blades. For this reason, in recent years, in order to improve the performance of a horizontal axis wind turbine, development of technology for analyzing the flow field around the blade (especially the blade surface pressure field) has been advanced, and based on the analysis result, the blade blade The mold is being developed and designed.

Conventionally, in order to analyze the blade surface pressure field around the blade of the horizontal axis wind turbine as described above, a hole for pressure measurement is formed on the blade surface, and a pressure transducer is connected to the hole to connect the blade blade. The surface pressure was measured (for example, refer nonpatent literature 1).
Maeda et al., “Unsteady Pressure Distribution on Rotating Blade of Mie University Open Air Rotor Research Facility”, 1999 European Wind Energy Conference, March 1999, p.121-124

  However, when the conventional pressure measurement technology as described above is adopted, a pressure measurement hole is made in the blade itself, so that the strength of the blade is reduced and the hole becomes clogged with dust etc. Repair was extremely difficult. In addition, since holes for pressure measurement are drilled in the blade itself, it is difficult to drill a large number of holes and to accurately set the hole position, resulting in limited pressure measurement points. It would affect the accuracy of blade surface pressure field analysis.

  In addition, when a conventional pressure measurement technique is employed, various devices such as a pressure transducer need to be disposed in the vicinity of the pressure measurement hole. Therefore, it is necessary to separately provide holes for maintenance of these devices on the blade surface. Therefore, in addition to requiring extra labor, the strength of the blade is reduced due to the drilling of the hole for maintenance.

  An object of the present invention is to prevent a decrease in strength of a blade and measure a pressure measurement hole very easily when measuring the blade surface pressure of a wind turbine blade.

  In order to solve the above-described problems, the invention according to claim 1 is a blade for a wind turbine that is divided into at least two divided blades along the length direction, and the divided blades are connected to each other by a connecting member. A metal plate having a cavity inside is interposed between the divided blades, and a pressure measurement through-hole penetrating from the surface of the metal plate to the cavity is formed. .

  According to the first aspect of the present invention, the wind turbine blade is divided into at least two divided blades along the length direction, and the divided blades are connected to each other with a metal plate interposed between the divided blades. They are connected by members. And the through-hole for a pressure measurement penetrated from the surface to the internal cavity is drilled in the metal plate interposed between the divided blades.

  Accordingly, since the blade surface pressure of the wind turbine blade can be measured through the pressure measurement through hole formed in the metal plate, the blade surface can be formed without forming the pressure measurement through hole in the blade itself. Measurement of pressure can be realized. As a result, it is possible to prevent a reduction in the strength of the blade. Further, since the metal plate can be removed from the blade, the through hole for pressure measurement can be prepared very easily.

  According to a second aspect of the present invention, in the wind turbine blade according to the first aspect, the metal plate has a cross-sectional shape having the same contour as a contour of a cross-sectional shape in a connecting portion of the split blade, and the split blade It bears the load which acts on.

  According to the invention described in claim 2, the metal plate has a cross-sectional shape having the same contour as the contour of the cross-sectional shape in the connecting portion of the divided blades, and bears a load (torsional load or the like) acting on these divided blades. Also functions as a “rib”. Accordingly, the buckling of the blade can be prevented, and it can contribute to the prevention of the strength reduction of the blade.

  The invention described in claim 3 is a horizontal axis wind turbine, and includes the wind turbine blade according to claim 1 or 2.

  According to invention of Claim 3, the horizontal axis windmill which has the blade for windmills of Claim 1 or 2 can be provided.

  Invention of Claim 4 is a wing surface pressure measuring apparatus, Comprising: The said through-hole drilled in the said metal plate of the blade for windmills of Claim 1 or 2, and predetermined piping to the said through-hole And an air pressure measuring device connected via the cable.

  The invention according to claim 5 is a method for measuring the blade surface pressure of a wind turbine blade of a horizontal axis wind turbine, wherein the blade mounting step of attaching the wind turbine blade according to claim 1 or 2 to the horizontal axis wind turbine, A measuring device connecting step of connecting an air pressure measuring device to the through hole formed in the metal plate of the windmill blade via a predetermined pipe; and the pressure of the air flowing in through the through hole and the pipe And an air pressure measuring step for measuring with an air pressure measuring device.

  According to the invention described in claim 4 or 5, the air pressure measuring device is connected to the through hole for pressure measurement drilled in the metal plate of the blade for wind turbine through the pipe, and flows in through the through hole and the pipe. The air pressure can be measured with an air pressure measuring device. Therefore, the blade surface pressure can be measured without drilling a pressure measurement hole in the blade itself, so that a reduction in the strength of the blade can be prevented. Further, even when dust or the like is clogged in the through hole of the metal plate, the metal plate can be removed from the blade and repaired easily.

  Further, according to the invention described in claim 4 or 5, since the hole for pressure measurement is drilled, the drilling work is facilitated. Therefore, a large number of holes are provided to reduce the number of pressure measurement points in the same cross section of the blade. While being able to increase, it becomes possible to set the position of a hole precisely. Therefore, the accuracy of the blade surface pressure field analysis can be improved. Further, since the air pressure measuring device can be arranged near the metal plate, the device can be maintained at the same time when the blade is divided, and there is no need to separately provide a hole for maintaining the air pressure measuring device. Therefore, also from this point, it is possible to prevent the strength of the blade from being lowered.

  According to the present invention, the metal plate having the pressure measurement through-holes is interposed between the divided blades, and the divided blades are connected to form the blade for the wind turbine. The blade surface pressure of the wind turbine blade can be measured through the pressure measurement through hole. As a result, the blade surface pressure can be measured without making a pressure measurement through-hole in the blade itself, so that a reduction in the strength of the blade can be prevented. Further, since the metal plate can be removed from the blade, the through hole for pressure measurement can be prepared very easily.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  First, the configuration of the horizontal axis wind turbine 1 according to the present embodiment will be described with reference to FIG. As shown in FIG. 1, the horizontal axis wind turbine 1 includes a tower 2 installed at a predetermined point, a nacelle 3 attached to the top of the tower 2, and an axially extending and pivotally supported by the nacelle 3. The main shaft is not provided, the rotor 4 is rotatably attached to the main shaft, and the like. As shown in FIG. 1, the rotor 4 includes two blades 10.

  Next, the configuration of the blade 10 (wind turbine blade) according to the present embodiment will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, the blade 10 has a divided structure that is divided into an inner wing 11 on the blade root side and an outer wing 12 on the blade tip side at the center in the length direction. Each of the inner wing 11 and the outer wing 12 is a divided wing in the present invention, and one end is screwed into a barrel nut fixed to the divided wing and a barrel nut of each divided wing, which is a connecting member (not shown). Connected by tension bolts.

  As shown in FIG. 2, a metal plate (stainless steel plate) 13 is interposed between the inner wing 11 and the outer wing 12 of the blade 10. The surface 13 a of the metal plate 13 forms the surface of the blade 10 together with the surface of the inner wing 11 and the surface of the outer wing 12. That is, as shown in FIG. 3A, the metal plate 13 has an airfoil cross section that is continuous with the inner wing 11 and the outer wing 12. The contours of the end surfaces of the metal plate 13 and the inner wing 11 that are joined to each other have the same shape. The contours of the end surfaces of the metal plate 13 and the outer wing 12 that are joined to each other are also the same shape. A hollow portion 13 b is formed inside the metal plate 13. The hollow portion 13b opens at both end faces of the metal plate 13 joined to the inner wing 11 and the outer wing 12, and is formed continuously between the both end faces.

  Further, as shown in FIG. 3, the metal plate 13 is provided with a plurality of pressure measurement through holes 13c penetrating from the surface 13a to the cavity 13b, and is not shown in each through hole 13c. Stainless steel tube is press-fitted. The through hole 13c is used for measuring the blade surface pressure described later. In addition, a tension bolt that connects the inner wing 11 and the outer wing 12 is inserted into the hollow portion 13 b of the metal plate 13.

  Next, a method for measuring the blade surface pressure of the blade 10 of the horizontal axis wind turbine 1 will be described.

  First, the above-described blade 10 is attached to the horizontal axis wind turbine 1 (blade attaching step). Then, as shown in FIG. 3A, the pressure transducer 20 is connected via a flexible tube 30 to the pressure measurement through-hole 13c formed in the metal plate 13 of the blade 10 (connection of the measurement device). Process). The pressure transducer 20 converts the pressure of the air that has flowed in through the through-holes 13c of the metal plate 13 and the flexible tube 30 into an electrical signal, and is a pneumatic measuring device in the present invention. In the present embodiment, the pressure transducer 20 is disposed in the cavity 13 b of the metal plate 13. The flexible tube 30 is a pipe in the present invention, and is connected to a stainless steel tube press-fitted into each through hole 13 c of the metal plate 13.

  Next, after connecting the signal line 40 shown in FIG. 2 to the terminal of the slip ring and connecting the pressure transducer 20 to the analysis device outside the blade 10 via the slip ring, the rotor 4 of the horizontal axis wind turbine 1 is rotated. The pressure of the air flowing into the pressure measurement through hole 13c formed in the metal plate 13 of the blade 10 and reaching the pressure transducer 20 via the flexible tube 30 is converted into an electric signal by the pressure transducer 20. The signal is converted and transmitted to the analyzer via the signal line 40 (pneumatic measurement process). Through the above steps, the blade surface pressure of the blade 10 is measured.

  In the horizontal axis wind turbine 1 according to the embodiment described above, the blade 10 is divided into at least two divided blades (the inner blade 11 and the outer blade 12) along the length direction, and a metal plate is interposed between these divided blades. In a state where 13 is interposed, the divided blades are connected by a connecting member. The metal plate 13 interposed between the divided blades has a through hole 13c for pressure measurement that penetrates from the surface 13a to the cavity 13b.

  Accordingly, since the blade surface pressure of the blade 10 can be measured through the pressure measurement through hole 13 c formed in the metal plate 13, the pressure measurement penetrating the inner wing 11 and the outer wing 12 of the blade 10. The blade surface pressure can be measured without drilling a hole. As a result, a reduction in the strength of the blade 10 can be prevented. Further, since the metal plate 13 can be removed from the blade 10, the through hole for pressure measurement can be maintained very easily.

  In the blade surface pressure measuring method according to the embodiment described above, the pressure transducer 20 is connected to the pressure measuring through hole 13 c formed in the metal plate 13 of the blade 10 via the flexible tube 30. Then, the pressure transducer 20 measures the pressure of the air that has flowed in through the through hole 13 c and the flexible tube 30. Since the blade surface pressure is measured without making a pressure measurement hole in the blade 10 itself, the strength of the blade 10 can be prevented from being lowered. Even when the through hole 13c of the metal plate 13 is clogged with dust or the like, the metal plate 13 can be removed from the blade 10 for easy repair.

  Further, in the blade surface pressure measuring method according to the embodiment described above, since a hole for pressure measurement is drilled, the drilling operation is facilitated. The number of measurement points can be increased, and the position of the hole can be set precisely. Therefore, the accuracy of the blade surface pressure field analysis can be improved. Further, since the pressure transducer 20 can be disposed in the vicinity of the metal plate 13, the pressure transducer 20 can be serviced simultaneously when the blade 10 is divided, and a maintenance hole for the pressure transducer 20 needs to be separately provided in the blade 10. Disappears. Therefore, the strength reduction of the blade 10 can be prevented also from this point.

  In the above embodiment, an example in which the blade 10 of the horizontal axis wind turbine 1 is configured with “two” split blades (the inner blade 11 and the outer blade 12) has been described. It is also possible to easily increase the number of measurement points by composing a blade with blades and interposing a metal plate with a measurement through hole between each divided blade.

  Moreover, in the above embodiment, the example which employ | adopted the "pressure transducer" as an air pressure measuring device was shown, However, The pressure of the air which flowed in from the through-hole for pressure measurement drilled in the metal plate is measured. It is also possible to adopt other air pressure measuring devices that can be used.

  In the above embodiment, a “stainless steel plate” is used as the metal plate provided on the blade, but a metal plate made of another metal such as aluminum may be used.

  Moreover, in the above embodiment, it was set as the metal plate which has the same external cross-sectional shape as the cross-sectional shape of the division part end surface of a braid | blade. The cross-sectional shape drawn by the outermost line of the cross-section, that is, the outline of the cross-section may be the same, and the internal shape of the metal plate does not necessarily have to be the same as the internal shape of the end face of the divided portion of the blade. In addition, for example, the area of the hollow portion can be reduced without changing the outer shape of the metal plate, and the rigidity and strength of the metal plate can be increased.

  Moreover, in the above embodiment, the penetration type penetrating between both end faces of the metal plate is adopted as an example of the hollow portion of the metal plate, but the penetration type is not necessarily adopted. For example, a non-penetrating type in which a “concave portion” formed in a substantially central portion of one end face of the metal plate is a hollow portion may be employed. When such a “concave portion” is employed as the hollow portion, the rigidity and strength of the metal plate can be increased. Further, even when the “recess” is adopted as the cavity, a pressure measurement through hole can be formed as in the above embodiment, and the pressure transducer can be fitted into the cavity (recess). .

It is explanatory drawing for demonstrating the structure of the horizontal axis windmill which concerns on embodiment of this invention. It is a perspective view of the blade of the horizontal axis windmill shown in FIG. (A) is an expanded sectional view in the IIIA-IIIA part of the metal plate provided in the blade shown in FIG. 2, (b) is an enlarged view of the surface of the metal plate provided in the blade shown in FIG.

Explanation of symbols

1 Horizontal axis windmill 10 Blade 11 Inner wing (split wing)
12 Outer wings (split wings)
13 Metal plate 13a Surface (metal plate)
13b Cavity 13c Pressure measurement through hole 20 Pressure transducer (pneumatic measurement device)
30 Flexible tube (piping)

Claims (5)

A blade for a wind turbine, which is divided into at least two divided blades along the length direction, and these divided blades are connected by a connecting member,
A blade for wind turbines, characterized in that a metal plate having a cavity is interposed between the divided blades, and a through hole for pressure measurement penetrating from the surface of the metal plate to the cavity is formed. . The metal plate is
The blade for a wind turbine according to claim 1, wherein the blade has a cross-sectional shape having the same contour as a contour of a cross-sectional shape at a connecting portion of the split blades and bears a load acting on the split blades.   A horizontal axis wind turbine comprising the wind turbine blade according to claim 1. The through hole formed in the metal plate of the wind turbine blade according to claim 1 or 2,
An air pressure measuring device connected to the through-hole via a predetermined pipe;
A blade surface pressure measuring apparatus comprising: A method for measuring blade surface pressure of a wind turbine blade of a horizontal axis wind turbine,
A blade attaching step of attaching the wind turbine blade according to claim 1 or 2 to a horizontal axis wind turbine;
A measuring device connecting step of connecting an air pressure measuring device to the through hole formed in the metal plate of the windmill blade via a predetermined pipe;
An air pressure measuring step of measuring the pressure of air flowing in through the through hole and the pipe with the air pressure measuring device;
A blade surface pressure measuring method comprising:

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