JP2007016661A - Once-through type windmill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve efficiency of a windmill by the shape and arrangement of guide vanes of a once-through type windmill. <P>SOLUTION: A cage 30 fixing the guide vanes in an outside of power blades 2 arranged in a cylindrical shape is provided. A guide blade 31 for increasing flow rate for preventing wind from entering in a resistant side of the power blade 2 is attached at 62 degree in relation to a main flow direction of wind, an extension part 32 extending to an outside of the cage is provided, and the extension part 32 is bent to introduce wind to a thrust side. Wind is prevented from entering in a resistant side of the power blade 2 and wind flowing through the thrust side is increased and accelerated. Consequently, efficiency in high speed rotation zone is greatly increased. A guide blade 33 for flow speed blow-in toward the power blade 2 from a center of the cage is provided in the thrust side. Wind is prevented from passing through the thrust side, flow-in speed to the power blade 2 is increased and output in a low rotation speed zone is increased by providing accelerated guide blade for flow speed blow-in. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a once-through wind turbine having guide vanes that can be used for wind power generation and the like.

  There are two types of wind turbines: a propeller type wind turbine having a rotation axis parallel to the air flow and a once-through type (winding type) wind turbine having a rotation axis perpendicular to the air flow. The once-through wind turbine has a relatively simple structure, has a large starting torque, and has no directivity with respect to the wind direction, and has excellent characteristics as a wind turbine, and the efficiency is improved by providing guide vanes. It has been known.

  The once-through wind turbine has many advantages over the propeller type wind turbine. As described above, by always rotating in a certain direction without being influenced by the direction of the wind, there is no need for wind direction control as in the case of a propeller type wind turbine, and the wind energy can be stably absorbed, the structure is simple, lightweight and Since it has high rigidity, it can be manufactured at low cost, and since the bearing end portion is a relatively wide and large foundation, it has advantages such as easy connection with power utilization equipment such as a generator.

  Although this is a once-through wind turbine with many advantages, it can be effectively powered on the wind receiving side (propulsion side), but the opposite side (resisting side) receiving wind on the back side of the blade is received on the propulsion side. It was inefficient to counteract some of the power. In order to counteract this drawback and effectively use the intake air, it has been proposed to provide guide blades symmetrically on the outer periphery of the power blades as shown in FIG. 7 (2) and FIG. The guide vanes are accommodated in a cylindrical guide rod, and an output improvement of about 50% is obtained. (See Patent Document 1)

Japanese Patent Laid-Open No. 05-240141 JP-A-50-144842 JP 55-142978 A

  By providing symmetrical guide vanes, the wind flows as shown in FIG. 2, improving the efficiency of the once-through wind turbine. However, when the roles of the guide vanes are examined individually, as shown in FIG. However, there are guide vanes that do not contribute to efficiency improvement because streamlines concentrate on the resistance side of the impeller. The present invention examines the shape, position, and arrangement of the guide blades that contribute to improving the efficiency of the wind turbine based on the results of this study, and further improves the efficiency of the once-through wind turbine.

A flow-through windmill having guide vanes on the outside of the power vanes, in which the guide vanes for increasing the air volume provided on the resistance side form an extension extending outward from the outer periphery of the guide vanes, and the air volume toward the power vanes The power conversion rate is increased.
Further, it is a once-through type windmill having guide vanes outside the power blades, and provided with an acceleration guide blade bent from the middle to the power blade side on the thrust side, and accelerates the wind toward the power blade The conversion rate is increased.

By making the arrangement and shape of the guide vanes as described above, it is possible to prevent the wind from flowing into the resistance side of the power vanes, increase the amount of air flowing through and accelerate, thereby greatly improving the efficiency in the high-speed rotation range. Further, by providing a guide vane for speed flow blowing that is accelerated on the thrust side, it is possible to prevent the wind from coming off on the thrust side and the wind from reaching the power blade, and to increase the inflow wind speed to reduce the rotational speed range. The output at has been greatly improved.
Compared to the case without guide vanes, the output was 3.4 times and the torque was doubled. In addition, the output was 1.6 times and the torque 1.3 times that of the conventional eight-way symmetric guide vane once-through wind turbine.

First Embodiment As shown in FIG. 1, in a once-through wind turbine 1 of the present invention, a power blade 2 of a wind turbine 1 is a cylindrical plate of 30 aluminum plates having a thickness of 0.5 mm, a length of 40 mm, and a curvature radius of 38 mm. Are arranged at equal intervals at an attachment angle of 30 degrees.

A rod 30 for fixing the guide blades is provided outside the power blades 2 arranged in a cylindrical shape, and the air volume increasing guide blades 31 for preventing the wind from entering the resistance side of the power blades 2 It is attached at an angle α to the normal to the mainstream direction. According to experiments, α is optimally 28 degrees (62 degrees with respect to the wind direction). The air volume increasing guide vane 31 is further provided with an extension 32 extending outward from the rod 30, and the extension 32 is bent toward the center to guide the wind toward the thrust side.
Therefore, the wind is prevented from flowing to the resistance side of the power blade, and the air volume flowing through the thrust side is increased and accelerated, thereby improving the efficiency in the high speed rotation region.

  Further, as a thrust side guide vane, an accelerated flow velocity blowing guide vane 33 directed from the center of the thrust side guide vane toward the power vane is attached at an angle β with respect to a perpendicular to the main flow direction of the wind. According to experiments, β is optimally 25 degrees (65 degrees with respect to the wind direction). The accelerated flow velocity blowing guide vane 33 is provided with a bent portion 34 bent from the middle. By providing the accelerated flow velocity blowing guide vane 33, the wind is prevented from being blown out on the thrust side, the flow velocity of the air flowing into the power vane 2 is increased, and the output in the low speed rotation region is improved.

Second Embodiment From the first embodiment, the power blade 2 is formed by equally arranging 16 aluminum plates having a thickness of 0.5 mm, a length of 50 mm, and a radius of curvature of 100 mm at equal intervals. The same as in the first embodiment.

The improvement in efficiency of the once-through wind turbine of the present invention was confirmed as follows.
A two-blade propeller and a 4 mmφ core honeycomb-type rectifying plate were installed in an open-type wind tunnel to control the wind speed. In the wind tunnel, the once-through wind turbines of Examples 1 and 2 were installed at a position 800 mm from the current plate. The wind speed at the wind receiving surface is almost uniform throughout the entire area.
In this state, a torque detector, a rotation speed detector, and a torque motor generating reverse torque were attached to the windmill shaft, and the load torque and the rotation speed were input to a measuring instrument (computer) through a torque converter and recorded.

3 and 4 show the output (Cp) and torque characteristics (Cq) of the first embodiment with 30 power blades at a wind speed of 4.5 m / s. Note that λ on the horizontal axis is the tip peripheral speed ratio of the power blade 2, and λ = πD _B N / 60V _∞ .
(D _B : Diameter of impeller (m), N: Number of rotations (rpm), V _∞ : Wind speed (m / s)

An increase in the amount of air flowing through the power vane was recognized by providing a wind vane increasing guide vane on the resistance side, and the efficiency in the high-speed rotation region was greatly improved. Further, in the low-speed rotation region, an efficiency comparable to or higher than that of a wind turbine having eight guide blades was obtained.
In the low-speed rotation region, the efficiency was similar to that of the eight guide vanes. If the extended portion 32 of the guide blade for increasing wind force is not provided, the wind is lost on the thrust side in the low-speed rotation region, and the improvement in torque characteristics was not recognized to be remarkable.

  Table 1 and Table 2 show the output and torque characteristics of a conventional wind turbine having eight guide vanes and the wind turbine of the present invention when there is no guide vane at a wind speed of 4.0 m. The ratio was shown based on the value at.

  As can be seen from Tables 1 and 2, the output characteristics of the windmill according to the present invention are 3.4 times that of the case without the guide vanes and the torque characteristics are twice that of the windmills having 8 guide vanes. Significant improvements were observed, 1.6 times and 1.3 times, respectively.

5 and 6 show the output and torque characteristics of the second embodiment having 16 power blades 2.
Compared with the first embodiment with 30 power blades, the output characteristics are reduced by about 25%. However, the provision of the guide blade for increasing wind force and the guide blade for accelerating the flow velocity of the present invention provides significant performance. An improvement was observed.
The remarkable effect of the present invention was recognized when the angle of the guide vane was within the range of about 10 degrees from the optimum angle.

Sectional drawing of the once-through type windmill of this invention. Explanatory drawing of the flow of the wind of the conventional symmetrical guide blade. The graph which shows the output characteristic of 1st Example. The graph which shows the torque characteristic of 1st Example. The graph which shows the output characteristic of 2nd Example. The graph which shows the torque characteristic of 2nd Example. The perspective view of the conventional once-through type windmill. Explanatory drawing of the flow of the wind by the conventional guide blade.

Explanation of symbols

1 windmill 20 power blade 3 guide blade (Fig. 8)
30 籠 31 Airflow increase guide vane 32 Extension 33 Flow velocity blowing guide vane

Claims (6)

A once-through wind turbine having guide vanes on the outer side of the power vanes, wherein the guide blade for increasing the air volume provided on the resistance side has an extension extending outward. 2. The once-through wind turbine according to claim 1, wherein the air volume increasing guide vane has an angle of 62 degrees with respect to the wind direction, and the extension portion is bent so as to guide the wind toward the thrust side. A once-through windmill having guide vanes on the outside of the power blades, wherein an accelerated flow velocity blowing guide blade bent from the middle to the power blade side is provided on the thrust side. 4. The once-through wind turbine according to claim 3, wherein the accelerated flow velocity blowing guide vane has an angle of 65 degrees with respect to the wind direction and is bent from the middle toward the power vane. 3. The once-through wind turbine according to claim 1, wherein an accelerated flow velocity blowing guide vane that is bent from the middle to the power vane side is provided on the thrust side. 6. The once-through wind turbine according to claim 5, wherein the accelerated flow velocity blowing guide vane has an angle of 65 degrees with respect to the wind direction and is bent from the middle toward the power vane.

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