CN202247817U - High-efficiency underflow type energy dissipation facility - Google Patents

Abstract

The utility model relates to a high-effect underflow formula energy dissipation facility for guaranteeing hydraulic and hydroelectric engineering pivot buildings safety such as dam, sluice, constitute the absorption basin by the long frontier wall in both sides and bottom plate that link up between outlet structure export and downstream river course, violently be equipped with the tail bank that one top surface height is protruding in the absorption basin bottom plate at absorption basin afterbody export section department, the length L of absorption basin long frontier wall is tail bank apart from the distance of absorption basin entrance point and is L_k+(0.5～1.2)h_TWherein h is_TAnd a counter slope section channel bottom plate with the slope ratio of 1: 8-10 is arranged between the tail ridge of the stilling pool and the outlet end of the stilling pool, wherein the water depth of the stilling pool after jumping or the water depth of the stilling pool before the tail ridge is the same. The utility model discloses a reasonable in design structure, easy implementation, can effectively improve the pool of absorption and jump the back depth of water and make rivers transition mild, reduce engineering cost and low reaches river course flood control engineering's fund input, improve hydraulic and hydroelectric engineering's social and economic benefits.

Description

High-efficiency underflow energy dissipation facilities

technical field

The content of the utility model belongs to the technical field of water conservancy and hydropower process facilities, and relates to a high-efficiency underflow energy dissipation facility for ensuring the safety of key structures of water conservancy and hydropower projects such as dams and sluices. the

Background technique

In the construction of water conservancy and hydropower projects, flood discharge and energy dissipation is always one of the key technologies or major technical problems. Dealing with the problem of flood discharge and energy dissipation is an important way to prevent the discharge water carrying huge energy from brushing deep river channels, destroying embankments and even causing discharge structures to be scoured and damaged, thereby endangering the safety of dams, sluices and other pivotal buildings. One of the main tasks of the hydraulic design of the downstream of the discharge structure is to select and calculate the appropriate energy dissipation measures, so that it can eliminate the residual energy in a short distance downstream, and make the high-speed concentrated water flow of the discharge safely transform into the normal flow downstream. Slow flow to ensure the safety of the building. the

In the prior art, traditional energy dissipation measures mainly include three basic energy dissipation methods: underflow energy dissipation, deflected flow energy dissipation and surface flow energy dissipation. Among them, the underflow energy dissipation is to control the position of the hydraulic jump by means of certain engineering measures, and eliminate the residual energy through the surface tumbling and strong turbulence generated by the hydraulic jump. Practice has shown that the underflow energy dissipation not only has the characteristics of relatively clear flow pattern, relatively stable tail water, less atomization degree, and lighter downstream scour, but also has a very significant energy dissipation effect of the hydraulic jump. Therefore, at present, a large number of sluices, small and medium-sized overflow dams, high-head drainage structures and various drainage structures with poor geological conditions in this field mostly use underflow energy dissipation facilities, which have also achieved significant social and economic benefits. benefit. the

When using bottom flow energy dissipation, in order to achieve better economic benefits and better energy dissipation effects, there are two main engineering measures to control the hydraulic jump position: 1) Lower the height of the apron to form a stilling pool downstream ; 2) Build an energy dissipation ridge at the end of the apron to block up the high water level, so that a stilling pool is formed in front of the ridge; in addition, combining the above two measures or setting auxiliary energy dissipators in the stilling pool can also control the water level. The function of jumping the position and improving the energy dissipation rate has also been widely used in practice. the

In previous textbooks and related design manuals on the hydraulic design of underflow energy dissipation facilities, the calculation method of the depth and length of the stilling basin was mainly introduced. Since the influence of the length of the side wall of the stilling basin on the position of the hydraulic jump was not considered in the hydraulic calculation, Therefore, how to determine the length of the side wall of the stilling basin and the connection mode between the outlet of the stilling basin and the downstream channel (bottom plate) have never been mentioned. In actual engineering, designers generally determine the length of the side wall simply according to the length of the stilling basin (that is, the distance from the inlet end of the stilling basin to the tail sill). The channel floor is designed as a horizontal or nearly horizontal slope. The above design forms seem to be in line with common sense, but often have the following deficiencies or defects: 1) The shape of the stilling tank is difficult to meet the requirements of all operating conditions; 2) When the flow rate is large, it often causes the illusion of insufficient depth or length of the stilling tank; 3. ) does not reflect the effect of the downstream water depth to the maximum extent from the principle of hydraulic jump formation; 4) often causes an increase in project cost due to its poor shape; 5) the secondary drop of the water surface behind the stilling pool is relatively large, resulting in Or the water level of the channel fluctuates greatly, thus increasing the investment in downstream river protection or embankment heightening. the

Utility model content

The purpose of this utility model is to solve the problems existing in the prior art, to provide a high-efficiency underflow type extinguisher with reasonable design structure, low engineering cost, easy implementation, effective improvement of the water depth after jumping of the stilling pool and gentle transition of water flow. able facilities. the

The technical solution for realizing the purpose of the above invention is as follows: the provided high-efficiency underflow energy-dissipating facility includes a force-dissipating structure connected between the outlet of the drainage structure and the downstream channel and composed of long side walls and bottom plates on both sides. A tail sill whose top surface is higher than the bottom plate of the stilling tank is horizontally set at the outlet section of the stilling tank. The distance between the tail sill and the entrance of the stilling tank is L _k , and the length of the long side wall of the stilling tank is

L=L _k +(0.5～1.2)h _T ,

In the formula, h _T is the water depth after the jump of the stilling pool or the water depth before the tail sill of the stilling pool, h _T = σ _j h″ _c , where σ _j is the submergence coefficient, and its value ranges from 1.05 to 1.10, and h″ _c is the stilling force Conjugate water depth of pool shrinkage section water depth h _c , h″ _c ≤ h _T .

The technical solution of the utility model also includes: between the tail sill of the stilling pool and the outlet of the stilling pool, a bottom plate of the uphill section channel with a slope ratio of 1:m is provided, where m=8-10. the

The high-efficiency underflow energy dissipation facility proposed by the utility model is based on the shape of the outlet of the traditional stilling pool, with the concept of maximizing the expression of hydraulic principles, and aiming at the different connection methods between the outlet of the stilling pool and the downstream river. Its innovation There are two aspects: one is the position of the end of the side wall of the stilling pool relative to the tail sill. Because the side wall is longer than the traditional stilling pool, it is called the long side wall of the stilling pool. The wall method can eliminate or reduce the influence of the drop of the water surface after the jump of the stilling pool on the water depth h _T of the stilling pool; secondly, in terms of the shape of the floor of the discharge channel downstream of the outlet of the stilling pool, since there is an inverse slope section of the bottom plate downstream of the tail sill, Therefore, it is called the reverse slope shape of the outlet of the stilling pool. It realizes the change of the water flow velocity and flow state in this section through the change of the cross-sectional area of the water within a certain length downstream of the tail sill of the stilling pool, so as to achieve the flow of the stilling pool and the downstream channel Or the smooth transition of the water flow in the retreat channel to eliminate or reduce the water surface fluctuation caused by the second drop of the water surface after the stilling pool. For the two connection methods between the stilling pool and the downstream river, the two innovative points of this patent can be used alone or in combination; The "river-style connection" in which the transitional section of the diffuser is connected to the river is also suitable for the "channel-type connection" in which the stilling tank is connected to the downstream channel through the receding open channel; while the reverse slope shape of the outlet of the stilling tank is mainly suitable for " channel connection". In actual application, the shape of the long side wall of the stilling pool and the shape of the reverse slope at the outlet of the stilling pool can be used separately or in combination, depending on the specific project.

Compared with the prior art, the main advantages of the utility model are: (1) The long side wall of the stilling pool adopted by the energy dissipation facility can effectively increase the water depth of the stilling pool after jumping, which is beneficial to the formation of an ideal hydraulic jump, Improve the energy dissipation effect of underflow energy dissipation; (2) The long side wall shape of the stilling basin adopted can reduce the length or depth of the traditional stilling basin, saving engineering costs; (3) The outlet of the stilling basin adopts reverse slope The body shape can reduce the flow velocity at the outlet of the stilling pool, slow down the secondary drop of the water surface of the pool, and make the transition of the water flow smooth; (4) The reverse slope shape of the outlet of the stilling pool can reduce the water surface fluctuation of the downstream water flow, thereby reducing the downstream Flood protection investments in channels or river courses. (5) The design structure of the utility model is simple, easy to implement, and can significantly improve the social and economic benefits of water conservancy and hydropower projects. the

Description of drawings

Fig. 1 is a schematic diagram of the lateral structure of a specific embodiment of the present invention. the

FIG. 2 is a schematic diagram of the planar structure of FIG. 1 . the

Fig. 3 is a working principle diagram of the utility model. the

Detailed ways

The content of the utility model will be further described below in conjunction with the accompanying drawings, but the specific implementation form of the utility model is not limited to the following embodiments. the

Referring to the accompanying drawings, the high-efficiency underflow energy dissipation facility described in the utility model includes a stilling pool composed of long side walls 1 on both sides and a bottom plate. The tail sill 2 of the bottom plate of the stilling tank, the length of the long side wall of the stilling tank L = the distance between the tail sill and the inlet end of the stilling tank is L _k + (0.5～1.2)h _T , where h _T = σ _j h″ _c , is the water depth after the jump of the stilling pool or the water depth before the tail sill of the stilling pool, the value range of the submersion coefficient σ _j is 1.05～1.10, h″ _c is the conjugate water depth of the shrinking section water depth (h _c ) of the stilling pool, h″ _c ≤h _T ; between the end sill 2 of the stilling basin and the outlet of the stilling basin, a channel bottom plate with a slope ratio of 1:m (m=8～10) is provided to form a channel that can make the water flow after the jump and the downstream channel especially It is the reverse slope shape of the outlet of the stilling tank that transitions smoothly with the water flow of the retreat channel.

Claims (2)

1. high-effect underflow type energy-dissipating installation; Comprise that one is connected and between outlet structure escape works outlets and downstream river course, forms absorption basin by long abutment walls in both sides (1) and base plate; It is high protruding in the tail bank (2) of absorption basin base plate to it is characterized in that being horizontally set with at absorption basin afterbody outlet section place one end face, and tail bank (2) is L apart from the distance of absorption basin entrance point _k, the length of the long abutment wall of absorption basin does

L＝L _k+(0.5～1.2)h _T，

H in the formula _TBe the absorption basin depth of water before the back depth of water or the absorption basin tail bank that jumps, h _T=σ _jH " _c, σ wherein _jFor flooding coefficient, its span is 1.05～1.10, h " _cBe absorption basin necked-down section depth of water h _cConjugate depth, h " _c≤h _T

2. high-effect underflow type energy-dissipating installation according to claim 1 is characterized in that between absorption basin tail bank (2) to the absorption basin port of export, being provided with the slope than being 1: the adverse grade section channel base plate of m, m=8～10.

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