RU2817592C2 - Water flow damper - Google Patents

Abstract

FIELD: hydraulic engineering.

SUBSTANCE: invention relates to hydraulic engineering and can be used to damp water flow energy after pressure water lines in a stilling well. Water flow energy absorber includes a well with vertical walls, supply and discharge water conduits, at that, the well is equipped with several levels of water flow reflectors fixed in its cavity below the supply water line, located symmetrically to the axis of the vertical well, wherein at the point of flow exit from the well, the hole of the latter is closed by a vertical cantilever wall, behind which there is an additional closed damping chamber with a threshold. Upper part of well in centre symmetrically to axis has cup narrowing downwards, below which the well is divided in height by multi-tier inclined partitions fixed inclined towards the vertical axis of the well, the middle part of the well has inclined cone-shaped partitions and additionally installed partitions in the form of arcs with a convexity towards the axis of the vertical well, lower part of the well has several levels inclined towards the axis of the well partitions, below which in the centre at the beginning of the outlet branch pipe there is a V-shaped flow deflector, which base is directed towards inclined partitions, and its top is directed towards outlet branch pipe and well of damping chamber.

EFFECT: higher operation efficiency.

1 cl, 1 dwg

Description

The invention relates to hydraulic engineering and can be used to dampen the energy of water flow after pressure water conduits in a water well.

A water flow energy absorber is known, including a water chamber and a flow divider, the bottom of the water chamber is made in the form of cylindrical surfaces located along the axis of the structure, and the flow divider is installed between them (Author's certificate SU E02B 8/06 dated June 28, 21982).

The disadvantage of the known damper is the incomplete elimination of the waves that arise along the way of damping the flow energy in the well over the entire range of flow rates passed through it, because The main damping occurs for the bottom current, which is a source of increased pulsation of velocities dangerous for the stability of the channel bed. The wave rolls through the jet-directing walls into the outlet bed of the channel.

A device for damping the energy of a water flow is also known, including a water well with vertical walls and a threshold located between the inlet and outlet channels with vertical walls and the outlet channel; it is equipped with two ledges, each of which is adjacent to one of the walls of the well in its initial parts and is made with an upper flat edge, a side vertical edge located in the same plane with the wall of the inlet conduit, and a front edge made with a slope towards the outlet channel (Author's certificate SU No. 1341326, E02B 8/06 dated 09.30.1987).

The disadvantage of this device is the presence of a flow concentrated in the central part of the device, entering the outlet channel and being a source of increased pulsation of speeds that are dangerous for the stability of the channel bed.

A known spillway includes a chamber, pressure galleries with gates connected to the upstream and connected to the mixing chamber towards each other, an air duct connecting the mixing chamber with the atmosphere, a water chamber located under the mixing chamber, and an outlet conduit connecting the water chamber to the downstream , while it is equipped with a transverse water trough wall installed in the water trough chamber under the mixing chamber and made with a concave edge facing upward and towards the upstream of a quarter of a cylindrical surface, the radius of which is equal to the length of the mixing chamber (Author's certificate SU No. 1504307, E02B 8/06 dated 08/30/1989).

The disadvantage is that after the collision of the flows in the mixing chamber and in the water chamber, there is no noticeable rotation, which mainly moves away from the center of the chamber; a flattened rotating flow is formed due to the rectangular shape of the chamber in cross section. Any swirling flow has two characteristic features: a vortex-containing central region (vortex core) with significant vorticity and a peripheral region with low vorticity. The vortex core is a non-stationary region of the flow in which disturbances arise that violate its axial symmetry. As a result, losing circulation, and with it losing the stabilizing force centrifugal field, the flow turns out to be unable to suppress these asymmetrical disturbances. And they move from a symmetrical shape to a spiral one. Further degeneration of the circulation leads to the disintegration of the circulation flow due to the weakness of the residual swirl. The description of the phenomenon occurs in outlet conduits over a long length (more than 60 of their diameters), as well as when a swirling flow enters under the tailwater level. Loss of movement should be considered unacceptable for high-pressure spillway structures.

This form of exit of a high-speed jet from a structure with the described disadvantages with a discharge conduit, with dynamics during the decay of the flow within the flow stroke, will be proposed below with a new technical solution.

In addition, another disadvantage is that in the body of the dam's retaining structure, the chamber is connected to an outlet conduit in the form of a pipe with flooding from the downstream to reduce the kinetic energy of the flow leaving the conduit. However, in such conduits there is a low throughput of flooded with escaping air, in which the flow movement occurs in the form of a plug flow in it. Thus, from the outlet (slit) in the water chamber, the outlet is located closer to the ceiling of the outlet pipe (water conduit), air accumulation occurs due to the backwater of water, since the tailwater is flooded, and such plugs cannot be completely eliminated. In addition, the possibility of water hammer cannot be ruled out, which negatively affects the reliability of the structure as a whole, and it is not effective enough when operating in open channel mode due to design flaws.

Water flow energy absorbers RU are also known: No. 2574472; No. 2524987; No. 2705849; No. 2708523. However, the known devices are complex, due to numerous elements in the manufacture, which means that their operation is insufficiently efficient; in addition, the very form of movement of the water flow depends on the location of the device elements in the chamber cavity, i.e. there is no stepped cascade of extinguishing partitions with turns when water moves along the height of the extinguishing chamber, and this does not make the chamber more economical.

The closest to the proposed purpose, technical essence and achieved result is a device for extinguishing the energy of a water flow, including an expanding well with vertical walls, curves in the form of arcs located in it symmetrically to the axis of the well, a threshold, inlet and outlet water conduits, and an expanding part of the well has the form of a truncated cone and is equipped with water flow reflectors fixed in its cavity below the supply conduit at several levels, located symmetrically to the axis of the vertical well and installed with large bases towards the bottom of the well, while each of the reflectors has the shape of a pyramidal divider, below which there are cyclic suppression bowls placed at the end of the expansion of the truncated cone, while at the point where the flow exits the well, the hole of the latter is blocked by a vertical cantilever wall and connected to the body in the form of an additional suppression chamber with a threshold, the upper part of which is connected to the outlet pipe and the outlet channel (Patent RU No. 2610126, E02B 8/06 dated 02/08/2017).

The disadvantage of the known device in the form of a water flow energy absorber is the insufficiently high damping of kinetic energy in the expanding cone, since it is limited by the expansion of the flow reflectors within the limits directly on the axis of the well in height, and therefore the insufficient efficiency of its operation. In addition, the missing mixing of the flow itself in a top-down motion upon impact towards the outlet connected to the well when using cascaded multi-tiered reflectors in the shape of a pyramidal divider.

It should be borne in mind that the damping effect in the known device decreases somewhat in the direction of water movement in the chamber, i.e. there is no multi-stage cascade of channels with turns when water moves along the height of the extinguishing chamber, and this does not make the chamber more economical.

The technical result consists in increasing the efficiency of the working chamber, which is divided in height by multi-tiered reflective screens (partitions) of different shapes installed in the form of inclined and curved towards the axis of the well, and a water well entering the bottom.

The technical result is achieved in that the energy absorber of the water flow includes a well with vertical walls, inlet and outlet water conduits, and the well is equipped with several levels of water flow reflectors fixed in its cavity below the inlet water conduit, located symmetrically to the axis of the vertical well, and at the point where the flow exits from the well, the hole of the latter is blocked by a vertical cantilever wall, behind which there is an additional closed extinguishing chamber with a threshold, according to the invention, the upper part of the well in the center symmetrically to the axis has a glass tapering downwards, below which the well is divided in height by multi-tiered partitions installed obliquely, fixed obliquely towards the vertical axis of the well, the middle part of the well has inclined cone-shaped partitions and additionally installed partitions in the form of arcs convex towards the axis of the vertical well, the lower part of the well has partitions fixed at several levels inclined towards the axis of the well, below which a flow deflector is placed in the center at the beginning of the outlet pipe V-shaped, the base of which is directed towards the inclined partitions, and its top is directed towards the outlet pipe and the well of the extinguishing chamber.

In addition, the outlet pipe is located at the point where the flow exits into the well, the hole of the latter is blocked by a vertical wall and connected to the housing in the form of an additional extinguishing chamber with a threshold, and the vertical wall is fixed below the outlet hole of the outlet pipeline.

This design of the damper from interconnected elements helps to dampen the energy of the water flow due to repeated changes in the direction along the height of the working mixing chamber from fixed multi-tiered screens (partitions) of various shapes in the transverse section with obliquely installed reflectors. Next, the flow flows towards the additional quenching chamber due to a vertical cantilever retaining partition located below the bottom of the outlet of the outlet pipeline. Thus, mass transfer of the flow is realized along the height of the chamber body with the water well.

The essence of the invention is illustrated by the drawing, where the energy absorber of the water flow is shown, a general view.

The energy absorber of the water flow includes a water conduit 1 with an inlet pipe 2 on top of the cover 3, an outlet pipe 4. The well 5 is made in multi-tiered cascades and consists of an upper height in the center symmetrically to the axis of a glass 6 tapering downwards. The middle part of the chamber 5 has partitions 7 of an inclined cone-shaped type and additionally installed spherical partitions 8 in the form of arcs convex towards the axis of the vertical well 5. The lower part of the chamber 5 has several levels of inclined partitions 9 fixed towards the axis of the well 5 and a V-shaped flow deflector in the form of a truncated cone 10 located in the center of the beginning of the outlet pipe 4 , the base of which is directed towards the annular gap of the partitions 9 inclined at an angle, and its top is directed towards the outlet pipe 4, which supplies the extinguishing chamber to the well 11. This arrangement of devices forms a multi-tiered channel with turns along the height of the chamber 5 to move the water flow down towards the truncated cone 10, then towards the outlet pipe 4 (the number of channels can be different in height with the devices located in the well 5).

The bottom 12 of the well 11 has an extension towards the outlet pipeline 13. An additional closed quenching chamber 14 is located behind the vertical cantilever wall 15, the bottom of the closed quenching chamber 14 of which is located in the same plane with the bottom 12 of the well 11, has a threshold 16. In this case, the closed chamber 14 extinguishing, which at the end has a partition 17, in plan is connected through the outlet hole 18 with the outlet pipeline 13, and the vertical cantilever wall 15 is fixed below the outlet hole of the outlet pipeline 13. The partition 17 is intended for applying the pressure effluent flow from the hole deck 11, where the total flow emerges with reduced bottom and surface velocities.

An example of a specific implementation.

The proposed design of the water flow energy absorber worked as follows. The incoming flow from the water conduit 1 passes through the inlet pipe 2, and was divided into several parts, one of which passed down through the constriction glass 6. For intensive extinguishing of water in the process of movement along inclined and spherical multi-tiered cascade channels formed by partitions 7, 8 and 9 with a truncated cone 10, they significantly with turns provide resistance, flow mixing and water pressure with increasing efficiency of extinguishing flow energy, while each part water in motion enters below the next stage of the inclined 7 and spherical 8 partitions, and several lower inclined partitions 9, filling, accordingly, the lower part of the chamber 5 in the area where the flow deflector is installed in the form of a truncated cone 10, the base of which is directed upward, where the flow moves with turns it is forced to mix along the height of chamber 5.

The angle of inclination of the partitions is determined by calculation based on hydraulic calculations of the structure as a whole, and is associated with the movement of the flow from top to bottom, which is a function of the speed of movement, in such a way as to ensure the movement of the flow towards the outlet pipe 4 into the well 11. Thus, the inclined partitions 7 , 9 and a spherical partition 8 in the form of arcs with a convexity towards the axis of the vertical well 5, create a drag on the flow moving down with support from the truncated cone 10, and affect the speed of the water. Taking into account its multiple rotations, leading to partial extinction of kinetic energy.

As the water flow moves along the height of the chamber 5, it mixes in layers and fills the cavity of the chamber 5. During this stratification of the flow, it is directed and continues to move down towards the truncated cone 10 and the outlet pipe 4. The vertical flow of water in the exit area of the well quenching chamber 11 is practically extinguished connects in it in the water column.

Filling with water in the lower part of the well 11 is at the same time a layer of thickness of water filling its level, which extinguishes the falling flow from above after its multi-tiered cascade and rotary movement due to channels formed between inclined partitions 7, 8, 9 of different shapes with a truncated cone 10, and The final damping of kinetic energy occurs in an additional closed chamber 14, the filling of which depends on the partition 17 above the outlet 18 of the threshold 16, as well as through the connection with the location of the cantilever wall 15, fixed below the outlet of the outlet pipeline 13.

The higher the efficiency, the greater the mass energy density of the velocity damping of the flow of multi-tier cascade channels between various inclined partitions in the form of their execution with an inclination towards the axis of the vertical well with rotations in a circle of the cavity of the chamber body 5, as well as with the additional operation of the closed damping chamber 14 from the side partitions 17 above the threshold 16 and the location of the cantilever wall 15. Where the flow is directed towards the outlet pipeline 13. Having finally extinguished the kinetic energy of the water flow, it makes it possible to significantly protect the outlet channel from erosion in the immediate vicinity of the outlet pipe connected to the extinguishing chamber.

To evaluate the effectiveness of the proposed construction of a water flow energy absorber, the presence of multi-tiered cascade inclined at an angle and spherical partitions, and a V-shaped flow reflector along the height of the chamber body, as well as with the flow of water onto the inclined partitions from above, the flow is initially divided in the center symmetrically to the axis of the well tapering glass downwards, turns out to be very effective and can be used for damping water flow after pressure water conduits in a water well, in which the proposed elements of the device are additionally located.

Claims (2)

1. A water flow energy absorber, including a well with vertical walls, inlet and outlet water conduits, wherein the well is equipped with several levels of water flow reflectors fixed in its cavity below the inlet water conduit, located symmetrically to the axis of the vertical well, with a hole at the point where the flow exits the well the latter is covered with a vertical cantilever wall, behind which there is an additional closed extinguishing chamber with a threshold, characterized in that the upper part of the well in the center symmetrically to the axis has a glass tapering downwards, below which the well is divided in height by multi-tiered partitions installed obliquely, fixed obliquely towards the vertical axis of the well , the middle part of the well has inclined cone-shaped partitions and additionally installed partitions in the form of arcs convex towards the axis of the vertical well, the lower part of the well has partitions fixed at several levels inclined towards the well axis, below which a flow deflector V- is placed in the center at the beginning of the outlet pipe shaped, the base of which is directed towards the inclined partitions, and its top is directed towards the outlet pipe and the well of the extinguishing chamber. 2. The damper according to claim 1, characterized in that the outlet pipe is located at the point where the flow exits into the well of the damping chamber, the outlet of which is blocked by a vertical wall and connected to the body of the additional damping chamber with a threshold, and the vertical wall is located below the outlet of the outlet pipeline.

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