JP2005090318A - Protection device for hydraulic turbine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a protection device for a hydraulic turbine capable of preventing a vane from being deformed and destroyed and preventing operation from becoming impossible even when a hard lump such as a broken part of a tree branch flows together with water in a water stream. <P>SOLUTION: This hydraulic turbine provided with an impeller between a water channel on the upstream side and a water channel on the downstream side is arranged, a chest wall is provided in close proximity to the impeller, and a water introducing channel for introducing water in the water channel on the upstream side into a part of the impeller is provided to obtain power. It is provided with an elastic part capable of bending a tip part of each vane of the impeller onto an inner side backward in the direction of rotation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a protection device for a water wheel having an impeller and a chest wall.

There are various types of waterwheels that have been used in the past. For example, a water wheel having a horizontal rotation shaft as described in Non-Patent Document 1 and an impeller rotating around the horizontal rotation shaft, a vertical rotation shaft and a bucket as described in Non-Patent Document 2 (for example, , Pelton turbine) or a turbine having a rotating body made of a runner (for example, Francis turbine). The former is mainly a small water wheel, and is used for a small head (about several meters to 20 meters), and the latter is used for a large head (200 to 1800 meters) or a medium head (40 to 550 meters). The present invention is mainly intended for the former small water wheel. Therefore, the former background art will be described.
Guidebook for small water wheel production, written by Fujiwara and Hosokawa, Power, May 1993 Fluid machinery, Murakami, Metoya, Morikita Publishing, published in March 1987

  The former small water wheel is based on the position of the water flow into the impeller, the shape of the blade, and the presence or absence of the chest wall. It is classified. These water wheels have a feature that the impeller has a large diameter, rotates at a low speed around a horizontal axis, and water flows in and out at a part of the outer periphery of the impeller. FIG. 6 shows an example of a chest water wheel. In FIG. 6, the chest water wheel is a water wheel in which an impeller 61 is surrounded by a chest wall 62, and a water guide path 63 is led to the upper part of the chest wall, and a gate (not shown) is provided there to enable adjustment of the amount of inflow water. is there. In the chest water turbine, the blade (water receiver) 61a of the turbine wheel is made of a hard material (for example, steel), and the gap 66 between the chest wall 62 and the blade 61a is selected to be small in order to reduce the entrance loss head. Further, the surface of the chest wall 62 is formed of a smooth surface made of metal or resin in order to reduce the flow resistance and the gap with the impeller 61.

  FIG. 7 shows an example of an underwater turbine. In FIG. 7, the underwater turbine is provided with a bottom flow gate 73 upstream, and water is introduced in the direction of the outer peripheral tangent below the impeller 71 to obtain power by the kinetic energy of the water. In the portion where the chest wall 74 is provided, the bottom surface and both side surfaces of the water channel surround the water wheel. The channel bottom has a slight (short) chest wall 74 as shown in FIG. In the underwater turbine, the gap 75 between the chest wall 74 and the impeller 71 is set narrow so that the kinetic energy can be sufficiently utilized.

Further, as a protection device for a water wheel, there is a conventional technique described in Patent Document 1. This conventional device is a protective device that reduces the influence of earth and sand collision and reduces the catch of dust. As shown in FIG. 8A, this conventional apparatus surrounds a main shaft 81 that rotates, a plurality of runners 82 that are mechanically connected to the main shaft 81 and give a rotational force to the main shaft 81, and the runner 82. A casing 83 that forms an annular water channel, a plate-like stay vane 85 that guides water flowing in the annular water channel of the casing 83 toward the runner 82, and covers at least a portion of the water flow side of the plate-like stay vane 85, The protective device 86 is fixed so as to be removable. As shown in FIG. 8B, the protection device 86 is provided at the tip portion of the stay vane 85 on the side into which water flows, and protects the tip portion.
Published patent publication, JP-A-7-42660

As shown in FIG. 6 or 7, the gaps 66 and 75 are both set narrow so that the water energy can be fully utilized. Further, the blades 61a and 71a of the impellers 61 and 71 are made of steel. Furthermore, in order to keep the gaps 66 and 75 narrow and keep the gap constant, the surfaces of the chest walls 62 and 74 must be made of a hard material such as iron. Therefore, when a hard lump such as a broken part of a tree branch flows together in the water flow, the blades 61a and 71a are deformed or broken, or the above-mentioned hard lump is not in the gaps 66 and 75. There was a problem that the water turbine would become inoperable due to being caught inside. Further, the protection device described in Patent Document 1 cannot solve the above problem.
The present invention provides a protection device for a water turbine that solves the above problems.

    According to the first aspect of the present invention, a water turbine provided with an impeller is disposed between the upstream water channel and the downstream water channel, a chest wall is provided in the vicinity of the impeller, and water in the upstream water channel is supplied to the impeller. In the water wheel provided with a water guide channel to be introduced into a part of the wheel, an elastic part capable of bending the tip part of each blade of the impeller backward inward in the rotation direction is provided.

According to a second aspect of the present invention, in the first aspect of the present invention, the water wheel is a chest water wheel or a lower water wheel.

The invention according to claim 3 is the invention according to claims 1 to 2, wherein the elastic part is provided with the tip part rotatably on the main body part of each blade of the impeller, A reinforcing rib is provided on the front side in the rotational direction of the main body portion to prevent the tip portion from bending forward in the rotating direction, and a coil spring is provided on the rotating portion to urge the tip portion toward the reinforcing rib side. It is characterized by that.

  In the present invention, since the tip portion of the blade is provided with an elastic portion that can be bent backward in the rotational direction, even if a hard mass flows into the gap between the impeller and the chest wall, the tip portion of the blade is inward in the rotational direction. Since the hard lump is discharged from the gap portion, the blade can be deformed or destroyed, or the hard lump can be caught in the gap and the accident that the water turbine becomes inoperable can be prevented. Have

  FIG. 1 is a side view of an embodiment of the present invention, and FIG. 2 is a front sectional view of this embodiment. This embodiment shows an example of a chest water wheel. 1 and 2, the impeller 2 of the water wheel 1 is installed close to the wall surface 22 of the chest wall 21 so as to have a substantially constant gap. It is desirable that a water conduit 23 is provided on the chest wall 21 and that the surface wall 22 is made of a material such as metal or resin smoothly. The impeller 2 of the water wheel 1 includes a cylindrical portion 3 at the center, and circular end plates 4 are fixed to both ends of the cylindrical portion 3. A rotating shaft 5 is fixed at the center of the cylindrical portion 3 by a V-shaped support plate 6. The head end portion of the support plate 6 is fixed to the end plate 4 by welding or the like, and the center portion of the support plate 6 is fixed by welding or the like so as to sandwich the rotating shaft 5 from both sides. The rotating shaft 5 is rotatably supported by bearings 7 and 7 on the left and right. The bearings 7 are respectively installed on the base 11.

  A circular side plate 8 having a diameter substantially equal to the diameter of the impeller 2 is fixed to the outer side surfaces of the end plates 4 and 4 by means such as welding or rivets. The impeller 2 includes a plurality of blades 9, and each blade 9 is composed of a blade body portion 9a and a tip portion 9b. The lower end of the blade body 9 a is fixed to the outer surface of the cylindrical portion 3 by welding or the like, and both side edges of the blade body 9 a are fixed to the inner surface of the side plate 8 by welding or the like. The lower end of the blade tip 9 b is rotatably connected to the tip of the blade body 9. Further, a reinforcing rib 10 is fixed to the rear surface of the blade 9 in the rotational direction on the rear surface of the blade body 9 a and the surface of the cylindrical portion 3 by welding or the like. The reinforcing rib 10 and the distal end portion 9b are not connected, and the distal end portion 9b is urged and pressed against the reinforcing rib by the spring means, as will be described later.

  FIG. 3 shows a connected state of the blade body 9a and the tip 9b. 4A and 4B show details of each member. As shown in FIG. 3, the connection part of the blade | wing main-body part 9a and the front-end | tip part 9b is provided with an incision alternately, and the other convex part is inserted in both sides with margin in one recessed part. Further, as shown in FIG. 4, ring portions 15a and 15b are provided on the convex portions 13a and 13b of the both 9a and 9b. The main body 9a is pivotally connected. The pin 16 is fixed to the side plate 8 by means such as a nut. Further, a coil spring 17 as shown in FIG. 4B is provided in the pin 16 so as to bias the tip end portion 9b against the reinforcing rib 10 in the gap between the convex portions 13a and 13b. FIG. 4B shows a side view and a front view of the coil spring 17, and a two-dot line indicates a state where the coil spring 17 is bent by a force.

  This embodiment is configured as described above, and functions as follows. That is, in the normal state, the tip 9b is urged by the coil spring 17, so that the back surface of the tip 9b is in close contact with the reinforcing rib 10 as shown in FIG. Accordingly, the water flowing in from the water conduit 23 is accumulated in the water tank formed by the blades 9 and the side plates 8 and 8, the blades 9 are pushed downward by the potential energy of the water, and the impeller 2 is as shown in FIG. Rotates counterclockwise.

  In addition, when obstacles such as stones and tree roots are mixed into the inflow water from the water conduit 23, the obstacles are in contact with the wall surface 22 away from the root of the blade 9 as the impeller 2 rotates. (See FIG. 5A). When the next blade comes in this state, the obstacle is sandwiched between the tip of the blade 9 and the wall surface 22. However, in the present embodiment, the tip 9b of the blade 9 is provided so as to be able to bend inside the rotation rear side, so that the impeller 2 rotates while the tip 9b is bent, as shown in FIG. The obstacle 24 is discharged downstream from the rotating region of the impeller. After the obstacle 24 is released, the distal end portion 9b is restored to the original state by the coil spring 17. FIG. 5 is a diagram illustrating this change. FIG. 5 (A) shows a state where the obstacle 24 is in contact with the wall surface 22, and FIG. 5 (B) shows the obstacle 24 on the tip 9 b and the wall surface 22 of the blade 9. Shows the state of being pinched.

Therefore, according to the present embodiment, even when obstacles such as stones and tree roots are mixed in the inflow water from the water conduit 23 and the inflow is mixed, the blade 9 breaks down and the impeller 2 cannot rotate. There is an effect that can be avoided.
Although the said embodiment demonstrated the example of the chest water wheel, this invention is not restricted to this case, It can apply also to the water wheel which has a bottom water wheel and another chest wall.

The side view seen from AA of FIG. 2 of embodiment which implemented this invention is shown. The front view of this embodiment is shown. The connection state of the front-end | tip part 9b of the blade | wing main body part 9a is shown. Fig. (A) shows the configuration of the connecting portion, and Fig. (B) shows the coil spring. FIG. 5A shows a state where the obstacle 24 is in contact with the wall surface 22, and FIG. An example of a conventional chest water wheel is shown. An example of a conventional water turbine is shown. The example of the water turbine provided with the conventional blade | wing protection apparatus is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Waterwheel 2 Impeller 3 Cylindrical part 4 Circular end plate 5 Rotating shaft 6 Support plate 7 Bearing 8 Side plate 9 Blade 9a Blade body part 9b Tip part 10 Reinforcement ribs 13a, 13b Projection part of blade body part and tip part
16 Connecting pin 17 Coil spring
21 chest wall 22 wall surface 23 waterway

Claims (3)

A waterway having an impeller is disposed between the upstream waterway and the downstream waterway, a chest wall is provided close to the impeller, and water from the upstream waterway is introduced into a part of the impeller. In the water turbine provided to obtain power, a protection device for a water wheel is provided with an elastic portion capable of bending a tip portion of each blade of the impeller backward inward in the rotation direction. The water turbine protection device according to claim 1, wherein the water wheel is a chest water wheel or a bottom water wheel. The elastic part is provided with the tip part rotatably on the main body part of each blade of the impeller, and provided with a reinforcing rib on the front side in the rotation direction of the main body part so that the tip part is bent forward in the rotation direction. 3. The water turbine protection device according to claim 1, wherein a coil spring is provided at the rotating portion to urge the tip portion toward the reinforcing rib. 4.

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