JPH06102885B2 - Water level prediction controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention maintains a constant water level downstream or upstream of a gate, in order to control water withdrawal from a river or to enable water diversion, respectively. The present invention relates to a water level prediction control device.

(Prior Art) As one of the prior arts used for the above-mentioned applications, there is one disclosed in Japanese Patent Laid-Open No. 2-171409. This is shown in FIGS. 4 and 5.

As shown in the drawing, the upstream water channel 2 of the gate 1 is communicated with the still water tank 4 by the water passage port 3, and the downstream water channel 5 of the gate 1 is communicated with the water channel tank 7 by the water channel port 6, and between the still water tank 4 and the water channel tank 7. A float chamber 8 is provided in which a float 9 is stored.

The other end of the water conduit 10 opened in the float chamber 8 serves as a water conduit adjusting port 10a, which is opened upward in the still water tank 4,
The packing is supposed to be filled even though it is opened downward. Further, the other end of the natural water guide pipe 11 which is opened on the downstream side of the float chamber 8 serves as a natural water guide port 11 a, which is opened in the water guide tank 7.

The float 9 is composed of a closed chamber 9a, which is partly defined in the lower part, and a water guiding chamber 9b, which is formed above the closed chamber 9a. A ventilation device 12 consisting of a simple hole in this case is provided near its top. One end of a communication pipe 13 is connected to the bottom of the water guiding chamber 9b, the communication pipe penetrates the sealed chamber 9a, and the middle of the communication pipe 13 is bendable so as to follow the movement of the float 9. The end is connected to a water pipe 14 that penetrates through the float chamber 8. One end of the water pipe 14 is opened downward in the still water tank 4 as a water flow control port 14a, and the other end is opened in the water guide tank 7 as a natural water flow port 14b. The sizes of the natural water inlet 11a and the natural water inlet 14b are appropriately determined according to the sizes of the float chamber 8 and the float 9 and the required opening / closing speed of the gate 1. The size of the mouth 10 and the water flow regulating port 14a is made sufficiently large, and the gap between the two is always one of the ports regardless of where the valve body 15a of the flow rate regulating valve 15 placed between them is. It is becoming narrowed.

The valve body 15a is fixed to the connecting rod 15b, and the openings on the opposite sides of the water guide adjusting port 10a and the water passage adjusting port 14a are closed by the packing 15c fixed to the connecting rod 15b, so that the connecting rod 15b has The floating body 25 is attached near the upper end with an appropriate height and is adjustable, and the communication port 16a has a small gap.
It is stored in a storage tank 16 that communicates with the still water tank 4.

Next, an example of a configuration in which the gate 1 and the float 9 are interlocked will be described. A shaft 17 is horizontally rotatably supported over both of them, and one driving sprocket 18 and a pair of driven sprockets 19 are fixed to the shaft 17 just above the float 9 and near the side end of the gate 1, respectively. Further, a main chain 20 and a follower chain 21 are suspended, a float 9 and a gate 1 are suspended at one end of each, and a float counterweight 22 and a gate counterweight 23 are suspended at the other end.

In addition, in order to prevent backflow from the water control port 10a when there is a possibility of backflow and to prevent flooding from the water transfer tank 7 when the downstream water level becomes extremely high, in such a case 6 is tubular, to prevent backflow,
Needless to say, an appropriate water control valve (not shown) is attached to this.

Next, the operation will be described.

First, if the flow rate decreases and the upstream water level drops, the containment tank 16
However, since the water flow from the communication port 16a is slow, the descending speed of the upstream water level is slower.
Goes down. Then, the valve body 15a connected to the floating body 25 is lowered to narrow the water guide control port 10a and the water flow control port 14a is expanded, so that the water level in the float chamber 8 is lowered to approach the downstream water level. The water level in the float 9 approaches the upstream water level, and a downward actuating force acts on the float 9 and the gate 1
Is closed and the water level in the upstream water channel 2 becomes high.

On the contrary, when the flow rate increases and the upstream water level of the gate 1 rises, the gate 1 opens and the upstream water level becomes low due to the action opposite to the above action. At that time, if the floating body 25 slightly moves, the water surface in the storage tank 16 moves in a direction opposite to the movement, the operating force is lost, and the same phenomenon occurs in the float chamber 8, so that the gate 1 is enlarged at a stretch. It does not move. Further, since the distance between the water flow control port 10a and the water flow control port 14a is set appropriately, the valve body 15a in the case of the opening motion and the closing motion of the gate 1
As a result, the difference in the position of the floating body 25 is extremely small, and
Since the water pressure applied to 15a is offset by the water pressure applied to packing 15c, the resistance of the valve is extremely small,
Therefore, the difference in the upstream water level between when the gate 1 is opened and when the gate 1 is closed is extremely small, so that the upstream water level can be kept substantially constant regardless of the flow rate. Further, since the floating body 25 is mounted so as to be adjustable, the above-mentioned control water level can be arbitrarily selected.

(Problems to be Solved by the Invention) It is actually difficult for the water level of the upstream waterway 2 to exactly match a predetermined planned water level, and the water level fluctuates around the planned water level. Since the gate 1 is opened and closed only based on whether the water level is higher or lower than the planned water level, there was a problem that the error in the water level was large.

This will be supplementarily described. The fact that the water level starts to rise after passing the lowest point means that the amount of storage has started to increase, which in turn means that the amount of runoff has begun to run short, so it is necessary to start opening Gate 1. In the prior art, the gate 1 continues to close in reverse until the water level rises to the planned water level, and starts to open only after reaching the planned water level, so the water level of the upstream water channel 2 rises.

On the contrary, if the water level begins to drop, it means that the amount of runoff is too large.Therefore, it is necessary to start closing before the water level reaches the planned water level, but actually it opens in reverse until the water level reaches the planned water level. As it continued, the water level in the upstream waterway 2 was sometimes too low.

(Means for Solving the Problems) In the present invention, in order to solve the above-mentioned problems of the prior art, a static water tank provided along a water channel, a float chamber, and a water transfer tank are provided. Is connected to an upstream water channel of a gate that is vertically movable in the water channel, the water transfer tank is connected to a downstream water channel of the gate, and the float chamber is accommodated with a float connected to the gate. The pipe communicating with the float chamber and the pipe communicating with the water guiding tank face each other, and the valve element is positioned between the adjusting ports of the respective tubes, and the valve body floats on the still water tank. In the water level control device of the water channel connected to, the floating body floated in the still water tank, at least the lower sealing portion, is composed of a water guiding portion located above it, and communicating with the atmosphere, the water guiding portion has its bottom portion. A water conduit that opens into the still water tank is installed at the bottom It is characterized in that a needle valve is provided so as to be adjustable so as to face the water conduit opening in the section.

(Operation) In the description of the present invention, if the inside of the water guiding section is the inner water level and the water level of the still water tank is the outer water level, the floating body in the still water tank is in balance and floats under the condition where the inner water level and the outer water level are set. become. When the outside water level rises, water also enters the water conduit from the water conduit, but a needle valve causes a delay. For this reason, a difference between the outer water level and the inner water level is created, the floating body rises rapidly, the valve body is switched, and the gate is opened before the upstream water level reaches the planned water level. Due to the rise of the outside water level and the discharge to the downstream, the outside water level has dropped below the planned water level, and the inside water level is rising toward the outside water level during this period, and the outside water level drops to the same water level, which satisfies the set conditions. . However, since the gate is open, the outside water level will drop.
Then, when the difference between the inner water level and the outer water level is reversed and the water level difference occurs, the floating body quickly descends to operate the valve body, and closes the gate before the upstream water level reaches the planned water level. The outside water level still drops while the gate is closing. After the inflow and outflow of the running water becomes the same, the inflow of the running water increases and the outer water level recovers while the inner water level catches up with the outer water level and satisfies the setting condition.
Therefore, the cycle in which the inner water level catches up with the outer water level requires the time for the water to come in and out of the introduced water, so the needle valve is adjusted. In this way, the closing operation of the gate is stopped and the opening operation is started early before the outside water level reaches the planned water level, so that the maximum water level does not increase.

Further, even when the outside water level has passed the maximum water level and started to drop, the opening operation is stopped early and the closing operation is started, so that the minimum water level does not become low, and therefore, the The issue has been resolved.

Also, too early, for example, past the minimum and maximum water levels,
If the inner and outer water levels of the floating body are immediately made equal, the outer water level will remain stationary and will not approach the planned water level.At that time, it can be adjusted arbitrarily by adjusting the degree of constriction of the inlet of the water guide section by the needle valve. There is no problem because you can.

(Example) An example of the present invention will be described with reference to Figs. However, the same members as in the related art will be described with the same reference numerals.

First, as shown in FIG. 1, the inside of the columnar floating body 25 is arranged from the bottom to the lower sealing portion 25a, the water guiding portion 25b, and the upper sealing portion 25c.
Is defined in. One end of the water guiding pipe 26 is opened at the bottom of the water guiding portion 25b, penetrates the lower sealing portion 25a, and the other end is opened in the water in the still water tank 4. Further, the lower end of the needle valve 27 is close to the upper opening of the water guiding pipe 26, and the needle valve 27 is engaged with a guide pipe 28 fixed to a hole penetrating the upper sealing portion 25c with a screw. In addition, the water transfer section 25
A ventilation pipe 29 opened on the upper wall of b penetrates the upper sealing portion 25c, and the other end is opened to the atmosphere.

Further, the volume of the lower sealing portion 25a is such that the floating body 25 is almost in equilibrium when the water level of the water guiding portion 25b (hereinafter, referred to as inner water level) and the water level in the water tank 4 (hereinafter, referred to as outer water level) are equal. The adjusting weight 30 is attached and adjusted so as to be perfectly balanced in the above state.

Regarding the height of the water guiding portion 25b, its upper end should be slightly lower than the highest expected water level when the floating body 25 is most raised, and its lower end should be slightly higher than the lowest water level expected when it is most lowered. Has been done.

A pair of adjusting ports 14a, 10 leading to the float chamber 8 and the float 9
The interval of a is made as small as possible, and its perimeter is made as large as possible.

A through hole 31 is provided at the center of the floating body 25.
The upper end of the connecting rod 15b inserted therein is screwed and fixed in a screw hole of a fixing plate 32 fixedly provided on the upper surface of the floating body 25.

A valve element 15a is attached to the lower part of the connecting rod 15b as in the conventional device, and the valve element 15a has a pair of adjusting ports 14a and 10a with an appropriate gap.
Facing.

Next, the operation will be described with reference to FIGS. 1 and 2. The purpose of the present invention is to make the water level in the still water tank 4 as close as possible to the planned water level in Fig. 2. However, it is necessary to fully understand the effects of increase and decrease in flow rate, vibration of the water surface, waves, etc. It is difficult to perfectly match the water level with the planned water level, and in detail, the outer water level in the still water tank 4 rises and falls with a cycle of several minutes as shown by the curve in FIG. The present invention is intended to prevent the swing of the gate 1 from increasing due to the delay of the opening and closing of the gate 1 when the outside water level changes cyclically as described above. The operation when the change in the external water level remains will be described.

Inside the water guiding portion 25b of the floating body 25, a still water tank 4 is provided via a needle valve 27.
Since the needle valve 27 appropriately narrows the upper opening of the water conduit 14, the inner water level rises and falls like the curve in FIG. 2 with an appropriate delay from the outer water level. And the outside water level have the same height at point B in FIG.
On the other hand, at point B, the closing operation of the gate is stopped.
When the water level continuously rises from the point B, a difference between the outer water level and the inner water level occurs, and the floating body 25 rapidly rises and is locked by the stroke of the valve body 15a as shown in the lower part of FIG. Disc 1
The gate 1 starts the opening operation by the operation of 5a.
Further, when the point E is passed, the floating body 25 descends rapidly and the valve body 15
Operate a to close gate 1.

Next, the position of point B will be described. If the position of point B is too close to point A where the outside water level is the lowest, the outside water level will not rise to the planned water level. On the other hand, when the outside water level is close to the point C where it becomes equal to the planned water level, the position of the point D where the outside water level is the highest becomes too high.

Therefore, the position of the point B must be approximately in the middle of the points A and C, but if the throttle of the needle valve 27 is changed, the curve showing the inner water level also changes. As the open / closed state changes, the curve of the outside water level also changes. Therefore, it is not necessary to fix the curve of the external water level to find the optimum point B and determine the throttling of the needle valve 27 so that the point B is the optimum, but to make the amplitude of the curve of the external water level the smallest. The trial determines the throttle of the needle valve 27.

Further, in order to reduce the amplitude of the curve of the outside water level, it is necessary to reduce the lifting amount of the floating body 25.
Since the distance between the adjusting ports 14a and 10a leading to the float 9 is made as small as possible, the amplitude of the curve of the outside water level can be made sufficiently small.

Further, according to the configuration of the present invention, the amplitude of the curve of the outer water level is always larger than the curve of the inner water level. Therefore, in order to reduce the amplitude of the outer water level, first, the amplitude of the inner water level should be small. However, the opening / closing speed of the gate 1 must be sufficiently high in order to reduce the swing of the inner water level. Therefore, since the peripheries of the adjusting ports 14a, 10a are sufficiently large, the distance between the adjusting ports 14a, 10a and the valve body 15a is small as described above, but the opening / closing speed of the gate 1 is sufficiently high.

Therefore, the height difference between the point D where the curve of the outside water level is the highest and the planned water level is sufficiently small. Further, even when the outside water level drops, the opening operation of the gate 1 is stopped early at the point E in FIG. 2 and the closing operation is subsequently started. Therefore, the amplitude of the external water level can be minimized.

Next, the operation when there is no periodic change in the external water level will be described.

If the outer water level fluctuates in a short cycle, the inner water level fluctuates later than the outer water level as shown by the curve in Fig. 2, but if the flow rate changes gradually, When the change is extremely slow, there is no difference in the water level between the outer water level and the inner water level, but in such a case, as described in the above configuration, the upper end of the water guiding portion 25b is in the state where the floating body 25 is most raised. Slightly lower than the expected maximum water level,
Since the lower end is slightly higher than the lowest water level expected in the most lowered state, if the outer water level becomes equal to the highest water level when there is a periodic fluctuation, the upper sealing part 25 will be submerged and the lowest water level will be reached. If they are equal, the lower sealing portion 25a is exposed in the air, the floating body 25 moves up and down, and the gate 1 opens and closes. Therefore, even in this case, the external water level cannot be higher than the expected maximum water level or lower than the minimum water level.

It should be noted that reducing the amplitude of the external water level in this way is
As can be judged from the drawing of the diversion channel on the left side of the figure, the water depth of the diversion channel fluctuates greatly due to changes in the external water level.
This is also to prevent the flow rate from changing, but reducing the change in water level is common knowledge regarding water control, and therefore detailed description is omitted.

Further, in the above, the technique applied by Japanese Patent Application Laid-Open No. 2-171409 is taken up as a conventional technique, but various techniques are conceivable as a technique for controlling a gate, a valve and the like using a floating body. Therefore, the technique to which the present invention is contrasted is not limited to the above-mentioned conventional technique, but can be widely used for a floodgate having a structure having another floating body if necessary.

(Effect) Since the present invention has the above-mentioned configuration, the rising / lowering timing of the floating body can be easily adjusted by operating the needle valve in the floating body, so that it can be operated in a range close to the planned water level. A stable water level can be controlled.

[Brief description of drawings]

FIG. 1 is a sectional view showing a floating body and its peripheral structure according to the present invention, FIG. 2 is a water level fluctuation diagram for explaining the operation of the device according to the present invention, and FIG. FIG. 4 is a side view showing an overall structure of a conventional technique in which a floating body according to the present invention is used, FIG. 5 is a plan view, and FIG. 1-gate, 2-upstream water channel, 3-water inlet, 4-hydrostatic tank,
5-downstream water channel, 6-water conduit, 7-water tank, 8-float chamber, 9-float, 25-floating body, 25a-lower sealed part, 25-
Water guiding part, 25c-upper sealing part, 15a-valve body, 10a, 14a-adjusting port, 26-water guiding pipe, 27-needle valve, 29-venting pipe, 30-adjusting weight.

Claims (1)

[Claims] 1. A static water tank provided along a water channel, a float chamber, and a water guiding tank, wherein the still water tank communicates with an upstream water channel of a gate that is vertically movable in the water channel, and the water guiding tank is A float connected to the gate is connected to the downstream water passage of the gate, and a float connected to the gate is stored in the float chamber, and a pipe connected to the float chamber and a pipe connected to the water transfer tank are opposed to each other in the still water tank. Then, the valve element is positioned between the adjustment ports of the respective pipes, and the valve element is a water level control device for a water channel in which the floating element floated on the still water tank is connected, and the floating element floated on the still water tank is At least the lower sealing part, and a water guiding part that is located above it and communicates with the atmosphere.The water guiding part is provided with a water guiding pipe opening to a still water tank at the bottom thereof, facing the water guiding pipe opened at the bottom. Characterized by the adjustable needle valve Water level prediction control device.