JP2008175374A - Air-entrainment inhibiting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air-entrainment inhibiting device simple in constitution by which air entrainment is inhibited in liquid that flows through a conduit having a free-fall in the course of the flow regardless of a variation in the flow rate. <P>SOLUTION: The air-entrainment inhibiting device 10 comprises a gutter which is provided from a horizontally extending torrent headrace 30 to the water surface 42 within a vertically downwardly extending shaft 40 in order to conduct the torrential water that flows out of an end 32 of a torrent headrace 30 and then vertically flows down to the water surface 42. In the gutter, a protrusive part 12 is provided in the flowing direction of the current from the end 32 of the torrent headrace 30. In response to the weight of the current flowing down through the gutter, the protrusive part 12 of the gutter bends in the direction to resolve the protrusion. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an air mixing suppression device that suppresses air from mixing into a liquid flowing in a flow path that changes from a horizontal direction to a vertical direction.

  Hydroelectric power plants collect water, which is a power source for rotating a power generation turbine, from many water systems such as mountain streams through water conduits.

  FIG. 4 is a cross-sectional view showing an example of the water channel 20 for collecting power generation water from the mountain stream water source into the main water channel 50.

  As shown in FIG. 4, water taken from a mountain stream is collected in a main channel 50 from a mountain stream intake channel 30 extending in a horizontal direction through a vertical shaft 40 extending vertically downward. In such a water collection process, water freely dropped from the end portion 32 of the mountain stream intake channel 30 to the water surface 42 accumulated in the shaft 40, and a large amount of air was mixed into the water on the water surface 42. Air may be entrained in the main channel 50 together with water and transferred to the power generation turbine. As a result, the air hammer phenomenon may not only damage the runner of the power generation turbine, but also reduce the power generation efficiency, so that the water introduced into the power generation turbine is not mixed with air as much as possible. desirable.

  On the other hand, conventionally, there has been disclosed a device that suppresses air mixing in a liquid flowing in a pipe that is piped through such a flow path that causes such a vertical drop (for example, Patent Document 1).

The air mixing suppression device described in Patent Document 1 includes a tank body having an overflow weir on the upper upstream side of a vertical pipe that is piped in a shape that generates a vertical drop, and a main divided flow path in the vertical pipe And a partition member that is divided into sub-divided flow paths. In addition, this partition plate has a dam member that dams the liquid flowing into the sub-divided flow channel to a certain depth in the tank at the upper end, and the main divided flow channel has a flow rate of the liquid flowing in the main divided flow channel. Is set so as to have a flow path cross-sectional area so that it is less than the flow rate overflowing from the overflow weir of the tank body. This is because the liquid overflowing from the overflow weir is accumulated in the main divided flow path of the vertical pipe to eliminate the vertical drop and prevent air from entering, and also overflows the weir member of the partition plate to prevent the secondary divided flow path. This is because the flow rate of the liquid flowing inside is reduced to reduce the amount of aeration.
JP-A-11-118089

  However, in the air mixing suppression device disclosed in Patent Document 1, it is necessary to install a tank body having an overflow dam with respect to a vertical pipeline that may be mixed with air, so that the installation becomes large. Therefore, introduction cost is required.

  Further, for example, when the flow rate of the liquid flowing over the overflow weir in the tank fluctuates in a decreasing direction and becomes smaller than the flow rate flowing through the main divided flow channel, the liquid is accumulated in the main divided flow channel. As a result, the vertical drop occurs, and the effect of suppressing air mixing decreases. On the other hand, when the flow rate of the overflowing liquid fluctuates in the direction of increasing, the flow rate of the liquid flowing over the partition plate weir member and flowing into the sub-divided flow channel increases, so that it overflows from the weir member. Since the flow rate of the liquid that freely falls into the sub-divided flow path also increases, the air mixing suppression effect is similarly reduced.

  The present invention has been made in view of the above points, and it is possible to suppress the mixing of air into the liquid flowing through the flow path that causes free fall in the flow process regardless of the fluctuation of the flow rate. An object is to provide a suppression device with a simple configuration.

In order to achieve the above object, the present invention is an apparatus that suppresses air mixing into a liquid flow in a flow path composed of a substantially horizontal horizontal path and a vertical path vertically connected to the end of the horizontal path. There,
Between the end portion of the horizontal path and the liquid level in the vertical path, has a ridge that guides the liquid flow that starts out in the vertical direction and flows out from the end of the horizontal path to the liquid level,
The scissors have a convex portion in the outflow direction of the liquid flow from the horizontal path end,
The convex portion is bent in a direction to eliminate the convex shape according to the weight of the liquid flow flowing down in the cage.
(First invention).

  According to the air mixing suppression device according to the present invention, it is not necessary to provide a large facility such as a tank body or overflow dam as described in Patent Document 1 in a flow path that needs to prevent air mixing. Cost can be reduced.

  In addition, when the flow rate of the liquid passing through the air mixing suppression device is a certain amount or less, the shape of the ridge provided between the end of the horizontal path and the liquid level in the vertical path is from the end of the horizontal path. By having a convex shaped part in the outflow direction of the liquid flow, it is possible to guide the liquid from the horizontal path to the liquid level in the vertical path while smoothly changing the flow, so air mixing into the liquid is prevented. Can be suppressed.

  Further, even when the flow rate is large, the convex portion of the ridge is bent in a direction to eliminate the convex shape according to the weight of the liquid flow flowing down the tub, so that the liquid flowing in the tub accumulates in the vertical path. Since the angle of flowing into the liquid surface becomes gentle, the effect of suppressing air mixing can be improved.

  A second invention is characterized in that, in the first invention, the scissors perform liquid flow induction in a non-free fall.

  According to the aeration apparatus according to the present invention, the liquid in the tub can be guided without being separated from the tub until it reaches the liquid surface of the vertical path from the end of the horizontal path. Can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the air mixing suppression apparatus which can suppress that air mixes into the liquid which flows through the flow path which produces free fall in the flow process irrespective of the fluctuation | variation of the flow volume can be provided with a simple structure.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
In order to use, for example, mountain stream water as a part of power for rotating a hydroelectric turbine, the air mixing suppression device of the present embodiment is installed in a water channel that guides water to the main water channel.

  FIG. 1 is an elevational view showing an installation state of the air mixing suppression device 10 according to the present embodiment in the water channel 20 shown in FIG. 4, and FIG. 2 is a cross section that crosses the longitudinal direction of the air mixing suppression device 10. It is a perspective view which shows a shape. In the following description, parts corresponding to those using the same configuration as in FIG.

  As shown in FIG. 1, the air mixing suppression device 10 is installed between the end 32 of the mountain stream intake channel 30 and the water surface 42 in the shaft 40.

  The air mixing suppression device 10 is a gutter having, for example, a substantially U-shaped shape in a cross section that crosses the longitudinal direction (see FIG. 2). Further, in the longitudinal direction, the convex portion 12 is provided at the outflow position of the water flow from the end portion 32 of the mountain stream intake channel 30, and the mountain stream water is gradually released from the end portion 32 of the mountain stream intake channel 30 to the water surface 42 in the shaft 40. It is guided by sliding down gradually from the inclined surface to the steeply inclined surface.

  Moreover, the air mixing suppression device 10 is made of, for example, an elastic material such as rubber, and is bent according to the weight of the mountain stream water flowing in the ridge.

Next, the shape of the air mixing suppression device 10 that deforms according to the flow rate of mountain stream water will be described.
FIG. 3 shows the shape of the air mixing suppression device 10 according to the flow rate of mountain stream water flowing in the ridge. FIG. 3 (a) is an elevation view when the flow rate is below a certain amount, and FIG. It is an elevational view when the flow rate is a certain amount or more.

  As shown in FIG. 3 (a), when the flow rate of mountain stream water flowing in the ridge is equal to or less than a certain amount, the shape of the air mixing suppression device 10 in the longitudinal direction is the convex shape portion 12 described in FIG. The shape is maintained, and the mountain stream water is guided from the end 32 of the mountain stream intake channel 30 to the water surface 42 in the shaft 40.

  On the other hand, as shown in FIG. 3 (b), when the flow rate of the stream water flowing in the ridge is a certain amount or more, the shape of the air mixing suppression device 10 in the longitudinal direction is the weight of the stream water flowing in the ridge. To bend downward so as to eliminate the convex shape of the convex portion 12. Thereby, the inflow angle to the water surface 42 in the shaft 40 of the mountain stream water flowing in the air mixing suppression device 10 becomes gentle.

  In both cases of FIG. 3 (a) and FIG. 3 (b), the stream water flowing in the ridge is a non-free fall water flow guide, that is, without separating the stream water from the ridge, It is designed to be guided from the end portion 32 of the mountain stream intake channel 30 to the water surface 42 in the shaft 40 while hanging a reed.

  In this design, for example, the unit weight of the water flow (weight per unit bottom area of the reed) is first obtained for each of the average water flow of the water flow in the reed and during the high water flow such as during the rainy season. And the rigidity which can maintain the self-shape of the said convex-shaped part 12 against the unit weight in that case at the time of average water amount, and the said convex-shaped part 12 bend without resisting the unit weight in that case at the time of high water amount When it is deformed and transitions from the high water amount to the average water amount, the elasticity that returns from the bending deformation and maintains the self-shape is calculated again, and the material, shape, and dimensions that have the rigidity and elasticity calculated here are selected. .

  Further, the self shape at the time of the average water amount (the shape of the convex portion 12 described above) is designed so that the bottom surface has a curve that substantially matches the angle at which the water flow at the time of the average water amount flows out of the end portion 32. Further, the shape at the time of the bending deformation is changed such that the outflow direction is changed downward so that the water flow at the time of the high water volume that is about to flow out from the end portion 32 does not collide with the inner surface of the opposing shaft 40 as it is. The bottom surface is designed to have a curvature that substantially matches the angle of the outflow direction. By performing such a shape design, the water flow in the ridge flows down to the water surface 42 along the shape of the ridge bottom surface without being separated from the bottom surface.

  As described above, the air mixing suppression device 10 according to the present embodiment has a mountain stream intake channel 30 between the mountain stream intake channel 30 extending in the horizontal direction and the water surface 42 in the vertical shaft 40 extending vertically downward. When the mountain stream water flowing out from the end 32 and starting to flow in the vertical direction is guided to the water surface 42, and the flow rate of the mountain stream water passing through the interior of the mountain stream is equal to or less than a certain amount, the convex portion 12 It is possible to perform guidance while smoothly changing the stream water flowing angle from the mountain stream intake channel 30 to the water surface 42 in the vertical shaft 40, and to prevent air mixing into the water.

  In addition, even when the flow of mountain stream water flowing through the ridge is large, the ridge convex portion 12 bends in a direction to eliminate the convex shape according to the weight of the water flow flowing down the ridge, thereby Since the angle at which the flowing mountain stream water flows into the water surface 42 that accumulates in the shaft 40 becomes gentle, the effect of suppressing air mixing can be improved.

  Moreover, according to the air mixing suppression device 10 according to the present embodiment, the stream water is designed to be able to guide the water flow in a non-free fall, so that the mountain stream water is transferred from the mountain stream intake channel 30 to the water surface 42 in the shaft 40. Since it can guide | invade without separating | separating from a collar until it reaches | attains, it can suppress air mixing in water.

  Moreover, according to the air mixing suppression device 10 according to the present embodiment, since it is not necessary to provide large facilities such as a tank body and an overflow dam as described in Patent Document 1 described above, the introduction cost can be reduced. .

  In addition, according to the air mixing suppression apparatus 10 by this embodiment, in order to use mountain stream water as a part of motive power for rotating a hydroelectric turbine, it installs in the water channel 20 which leads to the main water channel 50. However, the present invention is not limited to this, and can also be applied to a place having a structure in which water overflows the weir and falls freely, such as a weir installed in a river or the like.

  Moreover, according to the air mixing suppression device 10 according to the present embodiment, the target for suppressing air mixing is water, but the present invention is not limited to this, and any object can be applied as long as it is liquid.

It is an elevation view which shows the installation condition to the water channel 20 of the air mixing suppression apparatus 10 which concerns on this embodiment. 2 is a perspective view showing a cross-sectional shape that crosses the longitudinal direction of the air mixing suppression device 10. FIG. The shape of the air mixing suppression device 10 according to the flow rate of mountain stream water flowing in the ridge is shown. FIG. 5 (a) is an elevation view when the flow rate is below a certain amount, and FIG. FIG. It is sectional drawing which shows an example of the water channel 20 for collecting water for electric power generation from a mountain stream water source to the main water channel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Air mixing suppression device 12 Convex-shaped part 20 Waterway 30 Mountain stream intake 32 End 40 Vertical shaft 50 Main waterway

Claims (2)

A device that suppresses air mixing into a liquid flow in a flow path that includes a substantially horizontal horizontal path and a vertical path that is vertically connected to an end of the horizontal path,
Between the end portion of the horizontal path and the liquid level in the vertical path, has a ridge that guides the liquid flow that starts out in the vertical direction and flows out from the end of the horizontal path to the liquid level,
The scissors have a convex portion in the outflow direction of the liquid flow from the horizontal path end,
The convex portion is bent in a direction to eliminate the convex shape according to the weight of the liquid flow flowing down in the cage.
An air mixing suppression device characterized by that.   2. The air mixing suppression device according to claim 1, wherein the scissors perform liquid flow induction in a non-free fall.