Water flow energy absorber

Abstract

FIELD: hydraulic engineering.SUBSTANCE: used to absorb water flow after pressure water conduits in a water cushion. The water flow energy absorber comprises a water conduit 1, an inlet pipe 2, a well chamber 4, an inlet pipe 3 and a stilling well 16. The chamber 4 has in its internal cavity a vertical socket 5, with ends expanding upwards, the edges of which are provided with a horizontal shelf 6 with an annular gap and fixed by a base to a vertical hollow pipe 7, which is coaxially placed below and oriented toward an outlet pipe 8, having a socket 9 with ends expanding downwards towards the inlet pipe 3 into a stilling well 16. At the end of the socket 9 there is a ring reflector 13, below which a reflector 14 (screen) is fixed towards the conical bottom of the well. The bottom 15 of the stilling well 16 is provided with an inclined partition 17 with ends expanding upwards, towards the inlet pipe 3. The location inside the chamber 2 of the vertical pipe 8 and the outlet branch pipe 8 are connected by rigid connections 10, 11, 12 with the internal walls of the chamber 2, which increases their stability of individual multi-tiered elements in the direction of movement of the water flow, then into the inlet pipe 3 and into the well 16. The bottom 15 of the well 16 has inclined partitions 17 with ends expanding upwards and an extension towards the discharge pipeline 18. An additional damping chamber 19 is located behind the vertical console wall 20. The bottom of the damping chamber 19 is located in the same plane with the bottom 15 of the stilling well 16 and has a threshold 21. The damping chamber 19 has a partition 22 at the end and is connected in plan to the discharge pipeline 18 through the outlet opening 23. The partition 22 is intended to change the direction of the outflowing flow from the opening of the well 16 between the vertical cantilever wall 20, which is fixed below the outlet opening 23 of the discharge pipeline 18, which finally reduces the bottom and surface velocities in front of the discharge pipeline 18.EFFECT: flow is damped as a whole in all sections, a high degree of protection of the outlet pipeline and at its end from the dynamic effects of excess energy of the high-speed flow of the inlet water pipeline is achieved, which increases the reliability of the extinguishing structure, reduces the length of the outlet pipeline, simplifies the design and reduces the bottom velocities in the flow.1 cl, 1 dwg

Description

[0001] The invention relates to hydraulic engineering and can be used to quench the water flow after pressure water conduits in a stilling well.

[0002] A device is known for damping the energy of a water flow, which includes a stilling basin located under the vertical outlet section of a pressure water outlet of a circular cross-section, a flow energy damper installed above its bottom coaxially with the outlet section of the pressure water outlet, wherein the flow energy damper is made in the form of a round grate with radially arranged rods (Author's Certificate SU No. 1392189, E02B 8 / 06 dated 30.04.1988).

[0003] A disadvantage of the known damper is its low damping efficiency during jet splitting and subsequent flow aeration. This does not concentrate the flow in the stilling basin as it exits into the discharge channel. As a result, local velocities remain high at a considerable distance from the damper, leading to erosion of the channel bottom near the damper. Furthermore, the presence of splashes of mixing flows, as well as the uneven distribution of the flow across the stilling basin cross-section, which should be dampened by a circular grate, impair the efficiency of the damper, resulting in significant surface disturbances both in the stilling basin and along the discharge channel.

[0004] Also known is a water flow energy damper, including a horizontal section of a water conduit, an annular damping chamber, a spherical vibration screen with an upward convexity, a vertical inlet pipe installed at the end of the water conduit, the chamber has projections-limiters attached to its inner surface, the vibration screen is made with the possibility of vertical movement and has a stand in the form of a guide adjustment screw equipped with a spring, the chamber is additionally equipped with a screen in the form of a plate installed coaxially with the vibration screen, wherein the bottom of the plate is rigidly fixed to the projections-limiters on the side of the outlet pipe, the diameter of the screen of which is smaller, and the diameter of the vibration screen, and the body of the vibration screen is made with water intake windows, and its edges have a side wall bent upward along the radius (Patent RU No. 2574472, E02B 8 / 06 dated 1002.2016).

[0005] A disadvantage of the well-known water flow energy absorber is its complexity and, consequently, high material consumption, which leads to reduced operational reliability and, consequently, insufficient operational efficiency. Furthermore, the elastic spring is prone to metal fatigue during prolonged use, which can lead to failure and the need for replacement, as the vibration screen can fall downwards onto the additional screen and obstruct it. Another drawback is the lack of reduction in the efficiency of the dispersive outlet toward the well.

[0006] The closest in technical essence to the proposed one is a water flow energy absorber, including a horizontal section of a water conduit, an annular damping chamber, a screen with an upward convexity, a vertical inlet pipe installed at the end of the water conduit, the chamber has limiting protrusions attached to its inner surface, the screen is configured to move vertically, while the screen is installed coaxially with the inlet pipe, a stilling well, the inlet pipe is equipped with a nozzle, which is equipped with a cylinder installed on the outer wall of the nozzle on the side of a larger diameter with the possibility of axial movement, a conical spreader installed on the inner cavity of the nozzle coaxially with it and with an annular gap, while in the cavity between the inner wall of the nozzle and the outer wall of the conical spreader, guide plates are installed at an angle to the axis of the conical spreader, at the same distance from each other,wherein the angle of inclination of the guide plates to the axis of the conical spreader is greater than the angle of inclination of the generatrix of the conical spreader, in addition, the well has an internal annular horizontal shelf fixed below the conical spreader with an annular gap and located above the outlet opening of the discharge pipeline (Patent RU No. 2660931, E02B 8 / 06 dated 11.07.2018).,

[0007] A disadvantage of the known water flow energy absorber is the complexity of the design of the nozzle with axial movement on the outer surface of the cylinder with a conical spreader, which leads to insufficient operational efficiency and insufficient flow dispersal when it impacts the annular horizontal shelf in the well. Furthermore, the design of the conical spreader mounting is complicated by the need to move it using a nozzle limited by guide plates. There is a risk of jamming during movement if the nozzle is misaligned, as the force exerted by the side walls may vary unevenly.

[0008] It should be understood that unsteady flow refers to a fluid flow in which the flow rate (velocity) changes over time. Unsteady flows include transient processes in which the flow rate changes from one steady state to another. In this particular case, the flow rate changes from zero to a steady-state maximum value, which is diverted into a tailrace.

[0009] Thus, if energy accumulates in the well in the form of turbulent mixing of the liquid, a non-stationary period of the transient process occurs. This process of non-stationarity can negatively impact the lack of smoothing of the water flow in the well. Furthermore, the damping effect in a conventional damper is somewhat reduced toward the surface of the water in the well, meaning there is no collision of the flow streams with each other inside the well, which does not make the well chamber more efficient.

[0010] The technical result consists in increasing the efficiency of the energy absorber by maximizing the use of the damping of the kinetic energy of the incident flow.

[0011] The technical result is achieved in that in a water flow energy absorber, including a horizontal section of a water conduit in the form of a supply pipe, at the end of which an inlet pipe is located, a well with vertical walls and a well quenching chamber, the well has an internal annular horizontal shelf secured to the nozzle with an annular gap, a stilling well, according to the invention, the upper part of the vertical well is provided with a socket in the center, the edges of which are provided with a horizontal shelf with an annular gap, and the lower end of the socket is attached to a vertical hollow pipe, the base of which is oriented towards the outlet pipe installed below coaxially, which is additionally connected to the socket, the edges of which are provided with an annular reflector towards the conical bottom of the well and the inlet pipe into the stilling well, wherein the vertical hollow pipe and the coaxial outlet pipe are connected by rigid ties with the inner side walls of the camera body,which increases their stability in the direction of the conical bottom of the well with the inlet pipe, while at the point where the flow leaves the well, the opening is covered by a vertical cantilever wall and connected to the body, in the form of an additional quenching chamber with a threshold, the upper part of which is connected to the outlet pipeline, and the vertical cantilever wall is fixed below the outlet opening of the outlet pipeline.

[0012] The design of the damper, consisting of interconnected elements, helps dissipate the flow energy. The flow, entering the vertical expanding bell with an upper annular shelf, is compressed and directed toward the vertical hollow pipe. It then exits and re-enters coaxially into the lower branch pipe with an expanding bell, the ends of which are equipped with an annular reflector facing the conical bottom of the well. The elements are located inside the chamber body. Furthermore, the device elements are vertically stable, as they are rigidly attached to the inner side walls of the chamber body in the axial direction of the well.

[0013] In a stilling basin, the falling flow is initially directed toward inclined partitions fixed to the bottom of the basin, with their ends facing upward. The flow then expands. However, the presence of a vertical cantilever wall, forming an additional damping chamber connected to the discharge pipeline, where the vertical wall is fixed below the outlet of the discharge pipeline, effectively dampens the excess kinetic energy of the water flow. The flow in the basin, through the vertical wall, becomes a backwater, and the flow acquires a parallel-jet motion, allowing for more complete retention of the filling along the length of the discharge pipeline. The energy damper simplifies and improves the reliability of the structure by expanding the range and efficiency of flow energy damping.

[0014] The drawing schematically shows a water flow energy absorber, section.

[0015] The water flow energy absorber includes a water conduit 1 with an inlet pipe 2 with an expanding outlet transition section, an inlet pipe 3, a chamber 4. A fixed expanding bell 5 with its ends upwards, the edges of which are provided with a horizontal annular shelf 6 with an annular gap, a vertical hollow pipe 7 and a coaxially lower located relative to the outlet pipe 8 connected to the bell 9, the ends of which are directed downwards and devices in chamber 2, are fixed by rigid connections 10, 11, 12 in the form of rods or connecting plates to the side walls of chamber 2. In this case, the connecting connections 10, 11, 12, for example, in the form of plates, are directed along the flow vector so as not to impede their flow along the side surfaces towards the side walls of the vertical pipe 7 and the outlet pipe 8.In addition, in each specific case, the geometric parameters of the sockets 5 and 9 and the vertical pipe 7 and the outlet pipe 8 in the cavity of the chamber 2 are determined, as well as depending on the location of the coaxially located outlet pipe 8 below the vertical hollow pipe 7. In addition, the outlet pipe 8 with an expanding socket 9 downwards is equipped with an annular reflector 13 towards the conical bottom of the well 2, a horizontal circular reflector 14 and an inlet pipe 3.

[0016] The lower part of the chamber body 4 has a fixed reflector 14 (screen) with an annular gap oriented towards the bottom 15 of the well 16, which has an inclined partition 17 fixed to the bottom with its ends upwards towards the inlet pipe 3, and the well 16 has an extension towards the discharge pipeline 18 (or channel). An additional closed extinguishing chamber 19 is located behind the vertical cantilever wall 20, the bottom of the closed extinguishing chamber 19 of which is located in the same plane with the bottom 15 of the well 16, has a threshold 21. In this case, the closed extinguishing chamber 19, which has a partition 22 at the end, is connected in plan through an outlet opening 23 with the discharge pipeline 18. The vertical cantilever wall 20 is fixed below the outlet opening 23 of the discharge pipeline 18.The partition 22 is designed to change the pressure outflow flow from the opening of the well 16, which is blocked by the vertical console wall 20, into the discharge pipeline 18, where the total flow exits with reduced bottom and surface velocities.

[0017] Since multiple changes in the direction of water movement in chamber 2 are ensured, the vertical flow outlet depends on the position in which the location of the bell 5, vertical pipe 7 and outlet pipe 8 with the bell 9 are located, and the vertical pipe 7 and outlet pipe 8 located coaxially between themselves, respectively, the horizontal shelf 6, reflector 13 and screen 14 (reflector), as well as the expanding bells 5 and 9 with elements.

[0018] The materials used for manufacturing the damper inside chamber 4 can be steel, plastic of a given strength, or composite materials.

[0019] The water flow energy absorber works as follows.

[0020] Water comes from the water conduit 1, passes through the inlet pipe 2, meets the expanding bell 5 upwards, the edges of which are provided with a horizontal shelf 6 and is divided into several streams, and under pressure enters both the cavity of the vertical pipe 7 and bypasses the annular horizontal shelf 6 (flows around) with a gap towards the side walls of the chamber 4. From the cavity of the vertical pipe 7, the water flow under pressure coaxially enters the cavity of the outlet pipe 8 and passes into the expanding bell 9 downwards with an annular reflector 13 towards the conical bottom of the well 4. This flow in front of the conical bottom of the well 4 and the fixed horizontal circular reflector 14 (screen) with an annular gap then enters the inlet pipe 3 and goes out into the stilling pit 16.In this case, when the flow falls, it reaches the bottom 15 of the well 16, is additionally damped in the direction of the inclined partitions 17 fixed to the bottom 15 with expanding ends upwards and flows into the free space of the well 16, changing the direction of movement and fills the well 16.

[0021] It should also be noted that the dissipation of the jet energy occurs in the cavity of chamber 4 itself as a result of the intense separation, collision and deceleration of the incoming flow from the water conduit 1 with the inlet pipe 2; in general, this leads to the destruction of the jets and a decrease in the speed of the water flow.

[0022] Filling with water in the lower part of the well 16 with a fixed inclined partition 17 with expanding ends upwards is simultaneously a layer of the thickness of water filling its level, which dampens the falling flow from above, and the final damping of kinetic energy occurs in an additional closed chamber 19, the filling of which depends on the partition 22 above the outlet opening 23 of the threshold 21, as well as through the connection with the location of the cantilever wall 20, fixed below the outlet opening 23 of the discharge pipeline 18.

[0023] The efficiency is higher, the smaller the mass energy density of the flow velocity pulsations from the side of the partition 22 above the threshold 21 and the location of the cantilever wall 20, where the flow is directed towards the discharge pipeline 18. Having finally quenched the kinetic energy of the water flow, it makes it possible to significantly protect the discharge channel from erosion in the immediate vicinity of the discharge pipeline 18 (pipe), connected to the quenching chamber.

[0024] Thus, based on the interconnectedness and interdependence of the main components of the damping structure, this will increase the efficiency of damping excess kinetic energy of water. The efficiency of operation increases initially in the chamber cavity as the flow moves from top to bottom toward the inlet pipe, then as the flow falls toward the water level toward the inclined partition with its ends expanding upward, then as water fills the well in front of the cantilever vertical wall, and the partition in the additional chamber, adjacent to the opening of the discharge pipeline, i.e., the excess kinetic energy of the flow is effectively damped as the flow enters the pipeline.Due to such a step-by-step flow damping when the flow enters from the horizontal water conduit through known nodes, and taking into account the design of the hollow sockets, branch pipe and connection with the vertical pipe and with the annular shelf and reflectors located along the height in the chamber body as a whole, the dynamic loads on the well structure are not so high.

[0025] The advantage of the proposed invention is its increased efficiency in damping the energy of a high-velocity flow compared to the prior art. The proposed damping structure can be used to dampen the energy of a water flow in various hydraulic structures. It maintains the dimensions of the discharge channel attachment area behind the pipeline and reduces the size of the additional damping chamber across the entire range of discharged flow rates. The damping structure's design reduces manufacturing and installation costs.

Claims

A water flow energy absorber comprising a horizontal section of a water conduit in the form of a supply pipe at the end of which an inlet branch pipe is located, a well with vertical walls and a well damping chamber, the well has an internal annular horizontal shelf secured to the nozzle with an annular gap, a stilling well, characterized in that the upper part of the vertical well is provided with a socket in the center, the edges of which are provided with a horizontal shelf with an annular gap, wherein the lower end of the socket is attached to a vertical hollow pipe, the base of which is oriented towards a coaxially installed outlet branch pipe, which is additionally connected to the socket, the edges of which are provided with an annular reflector towards the conical bottom of the well and the inlet branch pipe into the stilling well, wherein the vertical hollow pipe and the coaxial outlet branch pipe are connected by means of connections to the internal side walls of the well damping chamber housing,which increases their stability in the direction of the conical bottom of the well with the inlet pipe, while at the point where the flow leaves the well, the opening is covered by a vertical cantilever wall and connected to the body in the form of an additional quenching chamber with a threshold, the upper part of which is connected to the outlet pipeline, and the vertical cantilever wall is fixed below the outlet opening of the outlet pipeline.

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