RU2484203C1 - Water discharge - stabiliser of water flow from channels with rapid flow mode - Google Patents

Abstract

FIELD: construction.SUBSTANCE: water discharge - a water flow stabiliser comprises a supply (3) and a transit (4) channels, a control gate and a bottom water-receiving gallery (1), having a water-receiving hole (7) in the upper part, and this hole is covered with a vibration grid (8), and in the bottom part there is a separating wall (9), coupled with the bottom of the transit channel. The bottom water-receiving gallery is connected with a discharge pipe (5) by means of a water discharge hole. The water discharge - the water flow stabiliser is also equipped with a jet-directing system in the form of separating plates (13) curvilinear in cross section, which are installed oppositely to the supply channel into galleries into a row, aligned in series along the length of the gallery hole. The upper edges of the plates are attached at the bottom to the grid, the ends of the rods (10) of which are bent down and rest against the separating wall, coupled with the bottom of the transit channel with the possibility to create self-excited oscillations of the grid. The gallery is arranged with permanent height along its entire length and a bottom (2) arranged as inclined. The gallery is divided along the length into sections with a transverse ledge (14) and a flat plate (15), attached by the base of the ledge and the edge of the plate at the bottom to the separating wall with partial coverage along the height of the throughput section of the gallery with gaps to the bottom of the gallery. The gallery of the bottom is equipped with a concave transverse plate (16) between the ledge and the flat plate in the form of a zigzag-shaped water conduit that narrows along the length of the gallery towards its end part.EFFECT: increased efficiency of operation by stabilisation of water discharge water flow due to change of hydraulic resistances with wave structure of a flow and efficient cleaning of water from drifts and debris.2 cl, 4 dwg

Description

The invention relates to hydraulic engineering and can be used to stabilize water supply from channels with a turbulent and extra-storm (wave) flow regime.

A well-known water outlet from the channel with a turbulent flow, including a well made in the bottom of the channel connected to the outlet conduit, a rotary shield mounted on a horizontal axis in the upper part of the well wall and facing the direction of flow, a horizontal visor, rigidly fixed in the upper part of the wall of the opposite wall well (USSR Author's Certificate No. 1028769, class ЕВВ 13/00, 1981).

Its disadvantage is low reliability, since the grate is a fixed element, contributing to the rapid clogging of the grate, an arbitrary change in the flow rate of the water outlet, and therefore the lack of stabilization of the discharge flow rate. This follows from the fact that as the wave turbulent flow regime increases, the pressure above the well opening increases. Partial capture of sediment into the well occurs. The flow entering a well of this size with a shield is extinguished, there are no hydraulic resistance elements, which causes a change in the discharged water flow in the well when the high-speed flow (pressure) in the supply channel changes, i.e. there is a lack of compression of the flow at the end of the well, which leads to a change in water flow in the outlet. As a result of such changes in the flow rate of the water, manual adjustment of the water supply processes is required. The design of the water outlet does not allow it, it carries out tasks in one technological cycle for a stabilized intake of water flow and effective purification of water from sediment.

Also known is a water outlet of a flow rate of water with a turbulent flow regime, including a supply and transit channels, a regulating gate and a bottom water intake gallery having a water intake opening in the upper part blocked by a grate, and in the lower part there is a dividing wall conjugated to the bottom of the transit channel, and the bottom water receiving the gallery is connected to the outlet pipe through a water outlet (Hydrotechnical structures. Edited by N.P. Rozanov, M: Stroyizdat, 1978, p.338-340, Fig. 25.3 "b").

The disadvantage of this outlet is the difficulty to translate the turbulent wave flow into a more relaxed state without the installation of special absorbers and the possibility of reliable operation. The water outlet has a low throughput due to the pressure difference in the cavity of the gallery of the screw flow and above the inlet, blocked by a grate. So, in the absence of access of air under the stream falling into the gallery, a vacuum is formed in a confined space near the wall of incidence, which has a bad effect on the operation of the water outlet. Therefore, the flow rate stability is insufficient as the flow rate exceeds the calculated one and, conversely, when the flow rate decreases it is less than the calculated one due to the lack of additional hydraulic resistances in the gallery. The sediments moving along the bottom of the inlet channel along the top of the grating web (especially large ones) in the direction of the transit channel to a small extent affect the intensification of the accelerated removal of large sediment from the grating. Clogging of the gaps of the grating occurs.

Fast-flow channels with slopes greater than critical (i≥0.02) can be wave, waveless (with anti-wave transverse profiles) and operating in two modes (in the wave mode - when skipping some costs and waveless - when skipping other costs). Consequently, new structures should be created taking into account the characteristics of the high-speed channel, which in this case acts as a source of water supply to consumers (for example, irrigation canals that feed from the high-speed channel).

The known device in this case, with frontal bottom water intake with lateral (at an angle) outlet with cutting off rolling waves from the water intake and dumping them in transit using transverse circulation to control sediment and, finally, to stabilize the water supply, the consumer does not allow to transfer a turbulent wave flow into calm state without the use of special absorbers. The profile of a rolling wave with entrained sediments has a sectional view of an elongated drop rolling along the surface of the stream. Due to this shape of the profile, the mass of the wave and, therefore, the flow rate along its length is different - maximum in the frontal part and decreasing towards the tail. Thus, there is a lack of flow, resulting from the uneven distribution of speeds and costs over the clearance of the gallery. Therefore, a state in the form of a jump occurs over the gallery in a turbulent state of the flow, and inside the gallery there is a change in the discharged water flow. In addition, the lack of security of protection of the gallery from sediment.

The aim of the invention is to increase the efficiency by stabilizing the flow rate of the water outlet by changing the hydraulic resistance of the flow during the wave structure of the flow.

This goal is achieved due to the fact that the outlet-stabilizer of the flow rate of water contains between the supply and transit channels a water-receiving gallery closed on top of the vibrating grid, which is equipped with a directional system in the form of dividing plates curved in cross section, attached to the bottom of the vibrating grill, and its ends are bent down and they are supported on the bottom of the dividing wall, conjugated to the bottom of the transit channel, with the possibility of self-oscillations of the lattice, i.e., providing the amplitude of oscillations of the lattice. Water flowing through the channel above the gallery is cut off by curvilinear plates, which prevents waves from spreading through the channel from the impact of flows under the lower part of the vibrating grating. As a result of this, transverse circulation arises here, due to it extrusion of bottom sediments, which then pass along the rods of the lattice, occurs. The stabilization of the discharge water flow is ensured by narrowing at the first stage in the gallery, formed by a protrusion across the gallery, located in the upper part of the gallery dividing wall. As a result of this, a helical flow from the upper layers of the gallery enters this narrowing (cut) with an increase in pressure flow in the direction toward the end of the gallery. To protect against the reactive effect of the passing water flow to the end of the gallery, before the water is drained into the outlet pipe, the upper part of the gallery is additionally equipped with an attached flat plate with a slope directed towards the initial part of the gallery, where the shape and dimensions of the lower part of the gallery can create a cut-off flow twisting - screw movement of a liquid (due to the influence of the gallery walls). In this case, a plate curved in cross section is attached between the protrusion and the flat plate to the bottom of the gallery, curved towards the end of the gallery. Since during the movement of the fluid particles of the cut-off stream lose their energy during multiple movements in their orbits, in order to maintain a practically unchanged energy ability of the flow within the orbit along the entire length of the gallery, the shape of the cross-section of the gallery allows stabilization of the water supply to the outlet. The flow rate of the outlet depends only on the opening of the shutter, i.e. Q = f (a). This means that the outlet-stabilizer of the flow is also a water meter, without moving parts.

The protective vibrating grating is pivotally fixed at the end of the ledge-threshold flush in the supply channel and is made with the ends bent downward from flexible elastic material, rests on the bottom of the gallery dividing wall, creating a self-oscillating process of the vibration grating along the length of the gallery clearance. The curvilinear plate guiding system, attached to the bottom of the vibrating grating, is also made of a material with a bulk density greater than the volume of the water weight, is installed in successive sections along the gallery and is reduced mainly to increasing the throughput in the initial part of the gallery and further stabilizing effect. This design approach can increase consumption by up to about 30%. The combination of pressure and non-pressure modes of movement was the reason for creating a new technical solution. Therefore, it can be noted that the stabilization of the outlet flow rate is achieved due to the simultaneous action of a change in the direction of flow due to sharp turns when the jet splits in the initial part of the gallery. The creation of rotation in front of the wall and the plate, compression and further loss of energy to create the rotation of the stream, which is formed at the beginning of the outlet pipe, which ultimately leads to a uniform and stable flow of water at the end of the pipe.

The originality and simplicity of the solution of the indicated design also provides protection against sediment in the fast-flow channels with sufficient accuracy of the flow stabilization quality, both in wave and waveless modes. At the same time, the presence of a step-threshold in front of the vibrating grate also creates a rise in flow and transfer of sediment in suspension and floating debris through the vibrating grate to the transit channel, and thus the hinge and rods of the grate are protected from destruction.

The profile and elastic material of the curvilinear plates attached to the bottom of the vibrating grating from the bottom allows moving (bending) towards the gaps in the grating. In this case, debris is constantly detached from the grate, and since the grate is installed on its curved ends in the direction of the water flow, sediment and debris are continuously moved by the water flow along the length of the grate and go beyond its limits into the transit channel. This ensures that the gallery is also protected from entrained sediment when the outlet is idle in automatic mode. This period at the facilities of reclamation systems is half or more of the whole time of the year.

When a water outlet is operating, the water flow through the gaps of the grating of the plate bends only by the amount necessary to pass the required water flow in the initial part of the gallery, thereby increasing the structural clearance between the rods of the vibrating grating, which increases the throughput of the device.

The total number of directing sections of the plates below the vibrating grid is taken depending on their purpose and size. The gallery path length is divided into labyrinths with protrusions and with stepwise arrangement of plates. So, making two zigzag turns, the jet is directed to the outlet pipe, forming in front of the hole a zone of screw movement of the liquid with a constant mass of water. Resistances along the length of the gallery are large, which positively affects the change in the wave structure of the stream at the entrance to the gallery. Resistance increases by about 3-5 times or more. The helical rotation of the liquid core in the final part of the gallery in front of the inlet of the outlet pipe looks most dense in cross section compared to the known device. It should also be noted that the length of the gallery is divided into working and idle closed parts. The working sections of the gallery are overlapped by the proposed elements so that along its entire length it is ensured that fine fractions of sediments are removed when water is taken into the drain. The estimated flow rate of the initial part of the gallery is assigned depending on the design of about 7-10% of the total gallery consumption. Hence, the working part along the length of the gallery based on the hydraulics of the variable-mass flow, taking into account the helical movement of the flow in the gallery, has not yet been completely solved. The flow itself forms a cross-section of the helical movement when the outlet is opened by a shutter. In turn, the installation along the length of the closed gallery of hydraulic resistances under these conditions leads to the complete elimination of the faulty flow at the end of the outlet pipe in the downstream, while uniform flow spreading behind the mount is ensured.

Based on the foregoing, the authors consider it possible to argue that the proposed technical solution meets the criterion of "Significant differences".

Figure 1 shows the outlet-stabilizer flow, in plan; figure 2 is a section aa in figure 1; figure 3 - node 1 in figure 2; figure 4 is the same, node 1, the rod of the lattice diamond-shaped section.

The water outlet contains a water intake gallery 1, made with an inclined bottom 2 between the inlet 3 and transit fast-flow channels with a wave structure of the stream. The lengthwise exit from the gallery is connected to a discharge pipe 5 (channel), in the input section of which a shutter 6 with a lifting mechanism is installed.

The water inlet 7 of the gallery 1 is protected by a vibrating grating 8 from the entry of debris and large stone. Gallery 1 is bounded above by a dividing wall 9, the upper end is connected to the free, bent down ends 10 of the vibrating grid 8, and the lower end of the separating wall 9 is connected to the pipe wall 5. The vibrating grill 8 is connected by a hinge 11 with a transverse step-threshold 12 flush in the supply channel 3. Gallery 1 is constant in cross-sectional height along its entire length. The vibrating grating 8 is equipped with a flow guide made in the form of dividing plates 13 curved in cross section mounted opposite the supply channel 3 in the cavity of the gallery 1 (in the initial part) in a row oriented sequentially along the length of the inlet 7 of the gallery 1. The upper edges of the plates 13 are attached from below to the rods of the vibrating grating 8. The hydraulic lengths are established along the length of the gallery, made in the form of a transverse protrusion 14 and a flat plate 15 with an attached base of the protrusion and the edge of the plate from the bottom to the ceiling of the dividing wall 9. The bottom 2 of the gallery 1 is provided with a concave transverse plate 16 curved towards the end of the gallery 1 and located between the protrusion 14 and the plate 15 with gaps to the bottom 2 and to the wall 9. The length of the gallery 1 is made in the form of a zigzag conduit in side of its end part. The guiding device in the form of curved plates 13 is attached to the rods of the vibrating grating 8 with the possibility of rotation and is made of a flexible material with a bulk density greater than the volume of the weight of water. The plates 13 due to the fact that they are made of an elastic material with a specific gravity greater than the specific gravity of the water, and can move towards the initial portion of the separation wall 9 due to the flow velocity, open the gaps between the rods of the vibrating grating 8. At the same time open the gaps between adjacent plates 13 oriented sequentially along the length of the hole 7. In the absence of water in the channel 3 and the idle outlet of the plate 13, on the contrary, automatically move to the rods of the vibrating grating 8 and cover the gaps waiting for them. This provides additional protection for the bottom gallery from accidental sediment entering the gallery from the sides of the channel (from slopes, etc.).

At the drainage facilities of reclamation systems, this period is half and more than the entire time of the year.

The trash-containing vibrating grating 8 can have rhomboid-shaped longitudinal rods (Fig. 4), and their ends are also equipped with elastic elements 10. By flowing around the rhomboid shape of the rods of the trash-holding vibrating grating 8, its throughput (with wave motion) can be increased to 10% on channels as with super-stormy, and with a turbulent course.

The operation of the device is as follows.

The high-speed flow from the inlet channel 3 through the slots of the vibrating grating 8 presses on the plates 13 and opens only by the amount (counterclockwise) necessary to pass the required water flow rate, thereby increasing the structural clearance between the plates 13. The entrained sediments moving along the bottom of the channel 13 and entering on the transverse threshold 12 are put into suspension, i.e. stirring them into the upper layers of the stream above the bottom hole 7 and raising solid particles with a bulk density of more than one, while the debris also rises. Suspended sediment movement occurs due to the vertical velocity component. Further, the transfer of part of the sediment load of a larger fraction, the characteristic size of which exceeds the size of the vibrating grating 8, goes downstream of the transit channel 4, due to vibrational movements of the rods of the vibrating grating 8 on the elastic elements 10, the bent ends of the rods of the vibrating grating 8 located on the dividing wall 9, by a hinge 11 connected to the step-threshold 12, i.e. the amplitude of the lattice vibrations and the speed of the turbulent flow towards the transit channel are provided.

The water flow entering the curved plates 13 is diverted to consumers through the outlet pipe 5 and is set by the opening of the shutter 6. At the same time, the water flow has longitudinal and transverse non-stationary speeds, flowing around the plates 13 also creates a self-oscillation mode of the vibrating lattice 8 due to the elastic elements 10 at the ends of the rods of the vibrating lattice 8, and thereby prevents clogging of the vibrating grating 8. In this case, pressure arises on the curved plate 13 from the side of the entrance to the gallery 1. Simultaneously with the receipt of the required water flow to gallery 1, water comes in a rotational motion. When twisting, part of the kinetic energy of the translational motion of the water flow passes into the kinetic energy of the rotational motion. As the flow enters and the pressure increases in the supply channel 3 to the gallery 1, the pressure inside it increases, the flow through the gaps between the protrusion 14, the bent plate 16 and the flat plate 15 enters the lower part of the gallery 1. Therefore, a rotational flow movement also occurs at this stage approaching the water outlet with pipe 5.

,The stream, getting into this stage of the conduit, has a helical movement and interacts with the plates 15 and 16, as a result, the free space of the screw air cord in the end part of the gallery 1 decreases, additionally determining the stabilization properties of the water flow into the outlet pipe 5. The compression of the screw stream flowing from the gaps between the narrowed part of the protrusion 14, the curved plate 16 and the flat plate 15, depending $$\epsilon =\frac{C}{\surd H_o}$$

,

which leads to a decrease in the discharge rate µ inversely proportional to √H _o . The degree of resistance can be increased by narrowing the internal cavity of the gallery 1 in the presence of a zigzag conduit. The constant circulating movement of fluid in the labyrinths of the gallery creates changes in hydraulic resistance provided by a zigzag duct inside the gallery 1.

The device allows you to take a stable purified water flow during the irrigation period of operation and does not require manual control of the water supply processes in order to remove sediment. The hinge 11 of the vibrating grid 8 allows you to lift it for inspection and repair of the outlet.

The increase in the total area of the openings of the vibrating grating 8, the rotation and dispersal of the cutting-off elastic systems of curvilinear plates 13 in the direction of the wave flow rate allows for uniform distribution of the selected flow rate over the gallery width 1 and thereby increases the throughput in the initial part of the water outlet, as well as eliminating ripples and surges on water surface.

From this it is clear that the pressures are distributed in such a flow according to the hydrostatic law, where, with helical motion and H = const, the velocity of all particles here is equal to: u = C (where C is the integration constant). According to the theory of wave energy, the following conclusions can be drawn. The total energy of the wave is the sum of the potential and kinetic energy. The amount of potential wave energy depends on the height of the liquid particles relative to their static position. The middle line, dividing the wave height into two equal parts, is raised above the static liquid level by the value of h _o .

According to the theory of waves, the amount of potential energy of one wave within a band of width b = 1 in the direction of propagation at the entire depth can be determined by the formula

. $$E_n=\frac{\gamma h^2\mathrm{<figure-callout\; id="16"\; label="\lambda "\; filenames="00000005.png"\; state="\{\{state\}\}">\lambda </figure-callout>}}{16}$$

.

The kinetic energy of the wave motion within the limits of the length of one wave and bands of width = 1 at the entire depth is quantitatively equal to the potential energy

. $$E_k=\frac{\gamma h^2\mathrm{<figure-callout\; id="16"\; label="\lambda "\; filenames="00000005.png"\; state="\{\{state\}\}">\lambda </figure-callout>}}{16}$$

.

The wave flow from the inlet channel does not exert its influence on the direction of the given water flow rate to gallery 1, thereby compensating for the excess flow rates resulting from the uneven distribution of velocities and flows in the frontal and tail parts of the wave, which ensures high stabilization of the flow rate supplied through the water outlet to the outlet pipe 5. The design of the outlet-stabilizer allows you to translate the turbulent wave flow into a calm state at the end of the outlet pipe 5, is characterized by high reliability. The gallery is not covered by sediment and debris, since they pass over the water inlet both due to the protrusion-threshold 12, and due to the presence of a vibrating grate 8 and a hinge 11, which also improves the cleaning efficiency of the grate. The guiding system, consisting of curved plates 13, during operation enhances the degree of vibration of the lattice 8 (the amplitude of vibrations of the lattice is ensured) with a hinge 11 above the gallery 1. In addition, the plate 15 during operation of the water outlet enhances the degree of rotation of the helical water flow in the end of the gallery 1 .

The economic efficiency of the proposed outlet-stabilizer flow consists in combining in one technological cycle the tasks of optimal intake of a stabilized flow rate and effective treatment of water from sediment and debris.

Claims (2)

1. A water outlet-stabilizer of water flow from channels with a turbulent flow regime, including a supply and transit channels, a regulating shutter and a bottom water intake gallery, having a water intake opening in the upper part blocked by a grating and a dividing wall in the lower part, interfaced with the bottom of the transit channel, moreover, the bottom water intake gallery is connected to the outlet pipe through a water outlet, characterized in that, in order to increase work efficiency by stabilizing the water flow rate of the water outlet due to To change the hydraulic resistances during the wave structure of the flow, it is equipped with a stream-guiding system in the form of dividing plates curved in cross section, opposite the supply channel to the galleries in a row oriented sequentially along the length of the gallery opening, with the upper edges of the plates attached to the bottom of the grating, the ends of its rods bent down and supported by a dividing wall, conjugated to the bottom of the transit channel with the possibility of creating self-oscillations of the lattice, while the gallery is made with constant over the entire length and height of the bottom, made oblique, and divided along the length into sections by a transverse protrusion and a flat plate attached by the base of the protrusion and the edge of the plate from below to the dividing wall with a partial overlap along the height of the passage section of the gallery with gaps to the bottom of the gallery, and the bottom it is provided with a concave transverse plate between the protrusion and a flat plate in the form of a zigzag conduit tapering along the length of the gallery towards its end part. 2. The outlet-flow stabilizer according to claim 1, characterized in that the curved plates attached to the grate and the bent ends of the rods are made of flexible elastic material.

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