RU1819935C - Water intake works - Google Patents

Abstract

Usage: in hydraulic engineering construction, in particular in water intake structures in mountain foothill zones. SUMMARY OF THE INVENTION: to increase the efficiency of operation, the threshold 2 of the water intake structure is made with a kink at an angle of 150-156 °, and along the length of its lower part there is a gallery 3, the bottom of which is deepened relative to the bottom of the structure, and the top is covered with a slab 4. The structure has a dump shaft 11c with a float actuator 10, a level gauge made in the form of a two-dimensional vessel, and the pump and compressor device is made in the form of a shield 6 fixed to the axis of rotation. 5 ill.

Description

Figz

FIELD OF THE INVENTION The invention relates to hydraulic structures, in particular to water intake structures of a mountain foothill zone.

An object of the invention is to increase the efficiency of a water intake facility.

In FIG. 1 shows a top view of a water intake structure; in FIG. 2 is a section AA in FIG. 1 (the position of the nanoscale device is open); FIG. 3 is a section BB in FIG. 1; in FIG. 4 is a section bb in FIG. 1; in FIG. 5 is a longitudinal sectional view of a level sensor in communication with the gallery, position 15 in FIG. 1.

The water intake structure includes a supply channel 1, an obliquely directed step threshold 2, consisting of an increased upper and lower lower steps and made in plan in the form of two straight lines intersecting at an obtuse angle of 150 ... 156 ° and facing the apex side of the supply channel. On the length of the lowered threshold step, which is 0.25.,. 0.35 of the total length of the threshold, a gallery 3 is arranged, the bottom of which is deepened relative to the bottom of the upper pool of the structure, is blocked from above by a plate 4 and attached to the lowered part of the step threshold by hinges 5 At the end of the gallery there is a nanoscale device made in the form of a flat shield 6 with an axis of rotation 7 attached to the supports of the structure and the wall 8, balanced by a counterweight 9 and equipped with a float actuator 10 located in the shaft 11, which is connected with an apparent hole 12 tailrace, level setter 13 with the water inlet chamber 14, and the level setter 15c gallery 3.

The level switch 15 is made in the form of two chambers 16 and 17 communicating with each other by a hole 18. In the front wall of the chamber 16 there is a control panel 19 with an inlet 20 in communication with the gallery 3. On the rear wall of the chamber 17 there is an inlet 21 of the pipe 22 connected with the shaft 11 of the float actuator 10. The bottom of the level adjuster 15 is sloped towards the wash hole 23, the opening of which is controlled by the valve 24.

The flow rates of the outlet channel 25 are controlled by shields 26, and the excess water entering the chamber of the water intake 14 is discharged through the overflow wall 27.

A shutter 29 is arranged on the river passage 28, which ensures the maintenance of the necessary pressure in the upper pool and guaranteed drainage to the outlet channel.

The operation of the water intake facility is described at low-water, mid-summer, and high-water flow rates characteristic of river sections of the foothill zone.

When low-flow water flows along the river, the operation of the water intake facility is reduced to the intake in the discharge channel 25 of the required water discharge, cleaned of sediment in accordance with the water supply schedule. The low-water period is characterized by relatively small discharges of water passing along the river, and a low concentration of sediment load. Working in a retaining mode, the upper pool of the structure acts as a single-chamber sedimentation tank where sediments accumulate, being pulled by its prism in

0 to the water intake side 14 and deposited at the oblique stepped threshold 2 and in the deepening of the open part of the gallery 3. The outlet of the gallery 3 is blocked by a shield 6 due to lack of water in the source.

5 During this period, 100% water intake into the discharge channel 25 is possible. If necessary, operating personnel carry out a short-term washing of the upper pool from sediment by forced

0 by the inclusion of the shutter 29 installed on the river span 28.

When passing through the river, the average summer water consumption exceeds the water consumption. The water entering the outlet channel has excess water, which should be used for washing

.. of the upper discharge from sediment and its discharge through the gallery 3 with the open position of the shield 6. The inclusion of the nanoswashing device in the operation is carried out as follows. The inlet of the downstream level adjuster 13 is set at the mark of the crest of the spillway 27, and the control panel 19 with the inlet 20

5 are located below the plate 4, communicating the gallery 3 with the shaft 11. Water through the inlet 20 enters the chamber 16 and through the hole 18-into the chamber 17. Upon receipt,. sediment is deposited with water in

0 of the lower part of the chambers 16 and 17, and the removal is carried out through the washing hole 23 by adjusting the valve 24. Purified water enters through the opening 21 into the pipe 22 and then into the shaft 11. When

5 the costs of the Veda entering the shaft 11, the large flow of water flowing from it through the drain hole 12, the shaft 11 is filled, which causes the hydrostatic pressure of the water to act on the pressure face of the float actuator 10,

providing rotation of the shield 6 around axis 7 and opening of the culvert hole of the gallery 3. A stable position of the shield b with the open culvert hole of the gallery 3 is ensured when the flow rates of the inflow and outflow to the shaft 11 are equal.

A decrease in the influx of water into the shaft 11 will cause the shield b to close the gallery culvert, as the water level in the shaft 11 and the hydrostatic pressure of the water on the pressure face of the float actuator 10 will decrease.

At water levels in the intake chamber reaching the crest of the spillway wall 27, water will begin to flow into the shaft 11 of the opening of the setter 13, regardless of the position of the setter level 15, filling it and ensuring that the shield 6 and the culvert opening of the gallery 3 are open.

Thus, with excess water in the river, they are primarily used to wash sediment into the downstream, preventing their entry into the intake chamber and then into the outlet channel. .

The operation of the oblique step threshold 2, the gallery 3 and the washing device in this period is as follows.

When the flow runs onto an increased part of threshold 2, a helical roller saturated with sediments is formed, the movement of which is carried out around the dynamic axis in the direction of gallery 3. Thanks to the device of gallery 3, which is blocked from above by a plate 4 with a bottom deepened relative to the bottom of the structure, along the length of the lowered part threshold, a zone of reduced pressure is formed in it, since atmospheric pressure is provided under the plate due to the location of the inlet 20 of the level gauge 15 below it. The helical roller, having originated in the area of the increased part of the threshold, moves in the direction of the washing gallery, transporting the deposits to the washing hole. When the wash hole is open, a helical roller saturated with sediment, without undergoing any change in the trajectory of movement and without losing its transporting ability, discharges the sediment through the wash hole, and the water in the intake chamber 14 and the discharge channel 25 comes clean of sediment.

The operation of the water intake facility during the flood period is characterized by the presence in the river of water discharges significantly exceeding the water discharged into the outlet channel. During this period, water supply. a certain opening of the river passage 28 remains open, since the shutter 29 is in

extreme upper position, ensuring the passage of the bulk of water and sediment through the river passage. The culvert hole, galleries 3, point 5 as a shield b also remains open, ensuring the operation of the screw drum for capturing and transporting sediment to the culvert hole of gallery 3 remains open. During the flood period, excess water is also discharged from the water intake chamber, 14 through the spillway wall 7, and the incoming water flow into the shaft 11. Through the level gauge 13, a stable open position of the shield 6 and 5 of the passage through the gallery 3 is provided.

, In the event of an emergency at the building, if the gallery 3 is clogged with floating bodies or large sediment fractions, the plate 4 is raised by turning relative to the hinges 5 and, leaving the shield 6 open, clear the littered gallery 3,

To substantiate the selected parameters for the claimed design of the intake structure, a model was made in

5 scale 1:20 and conducted research in the hydraulic laboratory of the Kyrgyz Agricultural Institute. K.I.Skrbin, which showed that the optimal parameters of the lowered part of the threshold are 0.25 ... 0.35 s

length, and the value of the angle between the oblique higher and lower parts

the threshold is within 150, .. 156 °.

Research results have shown that

5, the use of the proposed water intake structure in comparison with the prototype will allow:

to reduce by 15 ... 20% the entry into the outlet channel of fine sediment fractions in

0 form of sand of small and medium size;

to increase the efficiency of the construction by eliminating the obstruction of the oblique stepped threshold and gallery during its operation in the non-carrier mode,

 use excess water primarily to wash the upper pool and gallery from sediment,

to improve the operating conditions of the building, since automatic regulation of the flow rate of water for washing sediment is provided.

Claims (1)

SUMMARY OF THE INVENTION A water intake structure, including a supply channel, a water intake chamber, a nanowashing device and a step threshold of variable height, made in the form of straight lines intersecting at an obtuse angle, facing the apex towards the upstream and limiting the water intake chamber, wherein the threshold consists of an increased part of a variable height and a lowered part of a constant height located beyond their intersection in the direction of flow, characterized in that, in order to increase efficiency in operation, the threshold is made with a kink at an angle of 150 ° 156, and along the length of its lower part. which is 0.25-0.35 of the total length of the threshold, a gallery is arranged, the bottom of which is deepened relative to the bottom of the structure, and the top is covered by a plate pivotally attached to the lower part of the threshold, while the structure is equipped with a float 0 5 the drive with a dump shaft connected to the gallery and the water intake chamber by means of level meters located in the last, and the level meter, communicated with the gallery, is made in the form of a two-chamber vessel having a drain hole, in the walls of which are a control panel and an inlet of the pipeline in communication with the shaft, in addition, the nanoswashing device is located at the end of the gallery and is made in the form of a flat shield fixed to the axis of rotation, balanced by a counterweight and controlled by a dump ahte float drive. /, 6-in - I am 22 - D - W  -A - V & & tpЈ / &. 5