CN-121066124-B - Symmetrical backflushing type underflow energy dissipation structure

CN121066124BCN 121066124 BCN121066124 BCN 121066124BCN-121066124-B

Abstract

The invention discloses a symmetrical backflushing type underflow energy dissipation structure which comprises a stilling pool and a water drain pipe, wherein the water inlet ends of the stilling pool and the water drain pipe are respectively communicated with a water return structure of a water drain building, the water drain pipe is provided with at least two water drain pipe water outlet ends, the water drain pipe water outlet ends are respectively arranged at the water outlet ends of the stilling pool and are positioned at the left side and the right side of the cross section of the water outlet end of the stilling pool, and the water flow directions of the water drain pipe water outlet ends are opposite to the water flow directions of the water outlet ends of the stilling pool and are used for forming a counter-flushing with the lower water drain flow of the stilling pool. The scheme can solve the problems that under the condition that the existing underflow energy dissipation structure is limited in engineering topography conditions, a stilling pool cannot be widened, so that the flow rate is too large, the energy dissipation effect is poor due to large single-width flow, and the later maintenance is complicated and difficult due to the addition of auxiliary energy dissipaters.

Inventors

ZHANG JIANMIN
XU WEILIN
DENG JUN
TIAN ZHONG
ZHANG FAXING
HE XIAOLONG
PENG ZHIWEI

Assignees

四川大学

Dates

Publication Date: 20260512
Application Date: 20251110

Claims (8)

1. A symmetrical backflushing type underflow energy dissipation structure is characterized by comprising a stilling pool and a water drain pipe, wherein water inlet ends of the stilling pool and the water drain pipe are respectively communicated with a water return structure of a water drain building, the water drain pipe is provided with at least two water outlet ends of the water drain pipe, the water outlet ends of the water drain pipe are arranged at the water outlet ends of the stilling pool and are positioned at symmetrical positions on the left side and the right side of the cross section of the water outlet end of the stilling pool, the water flow directions of the water outlet ends of the water drain pipe are opposite to the water flow directions of the water outlet ends of the stilling pool and are used for forming opposite flushing with the lower water drain flow of the stilling pool, the water outlet ends of the stilling pool are provided with stilling ridges, the water outlet ends of the water drain pipe penetrate through the stilling ridges and are positioned on one side of the water facing surface of the stilling ridges, the water facing surface of the stilling ridges is a vertical plane, and the water outlet ends of the water drain pipe is flush with the water facing surface of the stilling ridges.
2. The symmetrical backflushing type underflow energy dissipation structure of claim 1, wherein the number of the water discharge pipes is identical to the number of the water discharge ends of the water discharge pipes, and one water discharge end of the water discharge pipe corresponds to an independent water discharge pipe, or the number of the water discharge pipes is one, and the water discharge ends of the water discharge pipes share one water discharge pipe.
3. The symmetrical, backflushing, underflow energy dissipating structure of claim 1 wherein the outlet end cross-sectional area of the drain pipe is less than the body cross-sectional area of the drain pipe, the outlet end of the drain pipe forming a structure having a reduced water passage area.
4. The symmetrical backflushing type underflow energy dissipation structure of claim 3 wherein the water outlet end of the water discharge pipe is of a duckbill type structure with narrow top and bottom and wide left and right.
5. The symmetrical recoil type underflow energy dissipating structure of any one of claims 1 to 4, wherein the water outlet ends of the water discharge pipe are located symmetrically on the left and right sides of the center of the water-facing surface of the relief ridge, respectively.
6. The symmetrical, backflushing, underflow energy dissipation structure of any of claims 1 to 4 wherein the flow rates of the two water discharge pipes are equal and the sum of the flow rates of the two water discharge pipes is 8.0% -16.09% of the flow rate of the water return structure.
7. The symmetrical backflushing type underflow energy dissipation structure of claim 6, wherein the two water drain pipes respectively comprise a vertical section and a horizontal section, one end of the vertical section is communicated with a water return structure of the water draining building, the other end of the vertical section is communicated with one end of the horizontal section, and the other end of the horizontal section is a water outlet end which is bent 180 degrees and is arranged at the water outlet end of the stilling pool and is used for forming water flow opposite to the downward water draining flow of the stilling pool.
8. The symmetrical backflushing type underflow energy dissipation structure of claim 7, wherein two water discharge pipes are obliquely arranged along the gradient of the stilling pool, one end of each water discharge pipe is communicated with a water return structure of the water discharge building, and the other end of each water discharge pipe is a water outlet end which is bent 180 degrees and is arranged at the water outlet end of the stilling pool and used for forming water flow opposite to the downward water discharge flow of the stilling pool.

Description

Symmetrical backflushing type underflow energy dissipation structure Technical Field The invention relates to the technical field of flood discharge and energy dissipation in water conservancy and hydropower engineering, in particular to a symmetrical backflushing type underflow energy dissipation structure. Background In the water conservancy and hydropower engineering, if the huge kinetic energy carried by high-speed water flow of a water drainage building is not effectively dissipated in the water drainage process, adverse effects are caused on the downstream river channel environment, so that in order to avoid serious scouring of the downstream river channel caused by the huge carried energy of the water drainage flow of the water drainage building, the stability of a side slope and the safe operation of the building are influenced, energy dissipation measures are generally adopted in engineering to dissipate or disperse the redundant energy in the water drainage process as much as possible, and the energy dissipation structure is important and difficult in engineering construction, and the rationality of the arrangement of the energy dissipation structure of the water drainage is directly related to the stability of a downstream river bed and the safety of the whole hydropower engineering. The dam site area in the large-scale water conservancy and hydropower engineering is mostly mountain canyons nowadays, and the topography of sluicing building low reaches is often the river deep and cuts to be "V" type narrow deep canyon, and the gradual beam is narrow to the low reaches, and the topography is asymmetric on both sides, and the condition that such river course is narrow, the flood head is high, the volume of leaking is big has brought very big challenge and difficulty for conventional sluicing energy dissipation structure arrangement mode. At present, common drainage energy dissipation modes can be divided into underflow energy dissipation, overflow energy dissipation and surface flow energy dissipation. The pickflow energy dissipation is most widely applied due to fewer limiting factors, but has higher requirements on the address of a downstream flushing area. The underflow energy dissipation is used as a conventional energy dissipation form, a hydraulic jump is formed in a downstream energy dissipation tank through drainage, spin rolling and strong turbulence generated by the hydraulic jump are utilized to eliminate residual energy, the device has the characteristics of stable flow state of the entering tank, high energy dissipation rate, small atomization of the drained water and the like, is widely applied to high-water-head and large-single-width-flow engineering, and meanwhile, in order to improve the energy dissipation efficiency and reduce the engineering quantity, auxiliary energy dissipaters such as an energy dissipation pier, energy dissipation teeth and the like are arranged in the underflow energy dissipation tank to perform joint energy dissipation, and the auxiliary energy dissipaters can play a role of improving the energy dissipation efficiency, generally can reduce the depth of digging and shorten the length of the tank. However, the existing underflow energy dissipation still has a plurality of defects, especially, under the condition of limited engineering topography conditions, the situation that the width of the energy dissipation pond cannot be further widened, so that the single wide flow in the energy dissipation pond is large, the water level fluctuates greatly and the flow state is disordered is caused, under the condition that a complex auxiliary energy dissipater is not arranged, the water depth is reduced, the fluctuation is reduced and the flow state becomes stable, cavitation is easy to occur at the front part of the energy dissipater under the high-speed water flow condition, in addition, a floating object or a transition riverway is arranged, the auxiliary energy dissipater is usually impacted and damaged, and the difficulty and the pressure are increased in the maintenance of the hydraulic building during operation. Disclosure of Invention The invention discloses a symmetrical backflushing type underflow energy dissipation structure, which aims to solve the problems that the existing underflow energy dissipation structure cannot be widened to cause poor energy dissipation effect caused by large single-width flow and the later maintenance is complicated and difficult due to the addition of auxiliary energy dissipaters under the condition of limited engineering topography conditions. In order to solve the problems, the invention adopts the following technical scheme: The symmetrical backflushing type underflow energy dissipation structure comprises a stilling pool and a water drain pipe, wherein the water inlet ends of the stilling pool and the water drain pipe are respectively communicated with a water return structure of a water drain building, the water drain pipe i