CN103898881B - Graded flow configuration energy dissipation method for deflecting water streams - Google Patents

Abstract

The invention discloses a graded flow configuration energy dissipation method for deflecting water streams. The method comprises the step that the water streams deflected by a plurality of outlet structures are graded in the longitudinal direction of a stilling basin and are arranged with the flow increasing grade by grade, wherein the distance of the water streams between the grades is at least 20 meters under the premise that Li-H cot (ai) +H cot (ai+1) is satisfied, the flows of all deflected water streams in the same grade in the transverse direction are equal, and the distance Li(j) between every two defected water streams is at least 20 meters. According to the method, the water streams with smaller flows can sequentially and firstly enter the stilling basin and move at the bottom and the secondary bottom of the stilling basin; on one hand, the water streams will not cause impact damage and abrasion damage to the bottom of the stilling basin, and on the other hand, a better overall energy dissipation effect can be achieved between the water streams and between the water streams and turbulence areas which are sequentially produced by the water streams and a part of existing water body at the bottom of the stilling basin; meanwhile, impact damage and abrasion damage to the stilling basin by the subsequent water streams with larger flows can be greatly relieved, and therefore the safe operation of hydraulic engineering is guaranteed.

Description

A kind of classification flow configuration energy dissipating method for choosing flowing water stock

Technical field

The invention belongs to Hydraulic and Hydro-Power Engineering flood-discharge energy-dissipating technical field, being specifically related to a kind of classification flow configuration energy dissipating method for choosing flowing water stock.

Background technology

The flip trajectory bucket mode that Hydraulic and Hydro-Power Engineering flood discharge adopts, be characterized in free jet overflow diffused air aeration first in atmosphere, consume part energy simultaneously, then fall into downstream absorption basin and form submerged jets, to be sheared by the strong current formed and turbulent fluctuation spreads energy dissipating.In order to improve effect of energy dissipation, weakening flip shot current washing away downstream, entering downstream river course after usually making flip shot current disperse as far as possible in different ways, prior art mainly adopts two kinds of methods to address this problem.First method is when adopting sluicing stream under single flood spillway in hydraulic engineering, design is optimized by choosing bank form to flood spillway end, aloft spread fully after making the disengaging of the current through choosing bank choose bank, dispersion enters in the absorption basin of downstream as much as possible, but along with under let out water flow increase, increase rapidly by optimizing the difficulty of choosing bank form raising dispersion of flow effect, lower sluicing stream is very easily concentrated and is entered in absorption basin, causes erosion damage to absorption basin.Second method is when flowing when sluicing under adopting multiple flood spillway (as spillway on dam body and spillway on bank) in hydraulic engineering, though the total Water let out under can disperseing to a certain extent, reduce absorption basin to a certain extent and cause erosion damage, but each flood spillway flow is not each other owing to having the clear and definite relations of distribution, cannot make full use of on the one hand each Spillway jetting flow to downstream absorption basin after each other interactional relation improve overall flood-discharge energy-dissipating effect, on the other hand also can because the flip shot water flow of spillway on dam body is excessive and Relatively centralized and destroying impacting property of absorption basin, affect the safe operation of hydraulic engineering.

Summary of the invention

The present invention be directed to prior art Problems existing, a kind of classification flow configuration energy dissipating method for choosing flowing water stock is provided.

A kind of classification flow configuration energy dissipating method for choosing flowing water stock provided by the invention, it is characterized in that the method is that the water stock of multiple outlet structure escape works flip shot is increased configuration along longitudinal classification of absorption basin step by step by flow, the water stock spacing between level and level meeting L _i– H cot (a _i)+H cot (a _i+1) under be at least 20 meters, the flow with one-level each flip shot water stock is equal, the spacing L between each flip shot water stock _i ^(j)be at least 20 meters.Wherein H is the depth of water in absorption basin, a _ifor water stock at different levels enters the incident angle of absorption basin.

Due to method provided by the invention, from vertical look up flip shot water stock can be made to increase step by step according to certain level and spacing enter absorption basin, this on the one hand can make each enter water overflow before entering absorption basin, horizontal and vertical superposition not occur and enter separately downstream absorption basin, less flow can be made to be introduced into absorption basin on the other hand, the surge caused absorption basin is like this little, also absorption basin bottom water flow flow velocity can not be made to improve too much, nature can not produce impact failure and ablation destruction to absorption basin, and after low discharge current enter absorption basin, according to jet kinetic characteristic, this strand of current mainly bottom absorption basin to downstream movement, water body also flow further downstream is together had can drive the part bottom absorption basin in the motion process of downstream simultaneously, and between water stock and absorption basin tail bank, form one backflow, produce turbulent fluctuation region, bring effect of energy dissipation, as shown in Figure 3, along with the flip shot current of the slightly bigger flow of next stage enter after in absorption basin, except the existing water body of absorption basin being driven to produce turbulent fluctuation from swimming in motion process in downwards, also to pass through the turbulent fluctuation region that upper level current are formed, the two turbulence intensity of being formed can be greater than undoubtedly adding of their turbulence intensities and, so just effect of energy dissipation can be strengthened, and when moving bottom this grade of flip shot current direction absorption basin, can directly impact on the adjacent upper level current bottom absorption basin, the water impact of two bursts of different directions motions both can increase energy loss when colliding greatly---energy dissipating, jet can be avoided again directly to impact on force reduction pool bottom, thus the surge that can effectively reduce on force reduction pool bottom.For follow-up along downstream step by step the water stocks at different levels of augmented flow enter the water movement process after absorption basin and produce energy dissipating effect can the like, so just can make full use of each Spillway jetting flow to downstream absorption basin after each other interactional relation improve overall flood-discharge energy-dissipating effect, also can eliminate the excessive and Relatively centralized of flip shot water flow because of spillway on dam body on the other hand and impacting property of absorption basin is destroyed.In a lateral direction, turbulent fluctuation effect is sheared owing to mutually can produce with water body in absorption basin after laterally each water stock enters absorption basin in every grade of current, part energy is consumed by shearing turbulent fluctuation, interaction is there is again between the turbulent fluctuation region that each water stock of transverse direction at regular intervals produces in absorption basin simultaneously, so just can further improve the turbulence intensity in absorption basin, reach the object consuming flow energy.

The water stock of flip shot is specifically divided into 1 grade, 2 grades, 3 grades along longitudinal classification of absorption basin by above method ... i level ... n level, the flow of every grade of current counts Q ₁, Q ₂, Q ₃q _iq _n, as shown in Figure 1, the water stock being positioned at same lateral attitude is one-level, and wherein in i level current, each stock water flow counts Q _i ⁽¹⁾, Q _i ⁽²⁾, Q _i ⁽³⁾q _i ^(j), as shown in Figure 2.Can not impact destruction to force reduction pool bottom in order to not only energy dissipating, preferred adjacent next stage water flow is 1.5 ~ 2 times of upper level flow, i.e. Q _i=(1.5 ~ 2) Q _i-1, and the spacing between level and level is meeting L _i– H cot (a _i)+H cot (a _i+1) under preferably 20 ~ 50 meters.

Transversely specifically Q is counted with the flow of one-level each flip shot water stock described in above method _i ⁽¹⁾, Q _i ⁽²⁾, Q _i ⁽³⁾q _i ^(j), its flow is equal, i.e. Q _i ^(j)=Q _i ^(j+1), and Q _i ⁽¹⁾+ Q _i ⁽²⁾+ Q _i ⁽³⁾+ ... + Q _i ^(j)=Q _i, the spacing L between each flip shot water stock _i ^(j)be preferably 20 ~ 50 meters.

The present invention compared with prior art, has the following advantages:

1) because the inventive method is that multiply flip shot current are carried out the configuration of classification flow, thus can make to be introduced into absorption basin successively compared with the water stock of low discharge and be positioned at bottom and time bottom motion, little to the surge of absorption basin on the one hand, can not to producing impact failure and ablation destruction bottom absorption basin, another aspect and the part bottom absorption basin have the turbulent fluctuation region that water body produces successively, except self is with except the energy dissipating effect produced each other, also greatly can weaken impact failure and ablation destruction that the follow-up water stock compared with large discharge produces absorption basin, kill two birds with one stone.

2) because multiply flip shot current can be entered absorption basin separately according to a determining deviation according to absorption basin size, the depth of water and immersion angle degree by the inventive method step by step, thus the size of existing absorption basin can be made full use of on the one hand, on the other hand because maintaining the energy entering flip shot current before absorption basin, stronger interactional turbulent fluctuation region can be produced with existing water body wherein after making it to enter absorption basin, better overall effect of energy dissipation can be reached, ensure the safe operation of hydraulic engineering.

3) the inventive method is skillfully constructed, and simply and easily implement, under realizing each flood spillway, lets out the optimization configured between water flow, improves absorption basin effect of energy dissipation, and ensures that hydraulic engineering flood discharge safe operation provides a kind of new solution route.

Accompanying drawing explanation

Fig. 1 chooses the view that flowing water stock enters absorption basin in the inventive method;

Fig. 2 chooses flowing water stock incidence point distribution schematic diagram in absorption basin in the inventive method;

Fig. 3 is that in the inventive method, water stock at different levels enters the interaction schematic diagram after absorption basin;

Fig. 4 be a kind of embodiment of the inventive method choose the view that flowing water stock enters absorption basin;

Fig. 5 be Fig. 4 choose flowing water stock incidence point distribution schematic diagram in absorption basin.

Detailed description of the invention

Below in conjunction with accompanying drawing, by the mode specifically implemented, the classification flow configuration energy dissipating method for choosing flowing water stock of the present invention is described further.What deserves to be explained is, protection content of the present invention is not limited to following examples.

Embodiment

The present embodiment is 9900m according to the flood discharge of letting out under needing in hydraulic engineering ³/ s, the flood discharge provided chooses flowing water plume amount configuration mode as shown in Figure 4,5, and namely along downstream longitudinal direction, lower sluicing stream total flow is divided into three grades, flow at different levels counts Q respectively ₁, Q ₂, Q ₃, first order horizontal direction arranges under three strands of current choose stream building (spillway on dam body) along sluicing and lets out, and flow counts Q respectively ₁ ⁽¹⁾, Q ₁ ⁽²⁾, Q ₁ ⁽³⁾, the second level arranges two strands of current and lets out under stream building (spillway on bank) is chosen in bank sluicing, and flow counts Q respectively ₂ ⁽¹⁾, Q ₂ ⁽²⁾, the third level arranges four strands of current and also lets out under stream building (spillway on bank) is chosen in bank sluicing, and flow counts Q respectively ₃ ⁽¹⁾, Q ₃ ⁽²⁾, Q ₃ ⁽³⁾, Q ₃ ⁽⁴⁾.Total bleeder quantity of the first order is decided to be Q by the present embodiment ₁=1800m ³/ s, the bleeder quantity of each water stock at the corresponding levels is just Q ₁ ⁽¹⁾=Q ₁ ⁽²⁾=Q ₁ ⁽³⁾=600m ³/ s, then select Q ₂=1.5Q ₁, Q ₃=2Q ₂and carry out each stock water operation of all the other secondarys by the configuration mode that every grade of each stock water flow is equal and be: Q ₂=2700m ³/ s, and Q ₂ ⁽¹⁾=Q ₂ ⁽²⁾=1350m ³/ s, the third level: Q ₃=5400m ³/ s, and Q ₃ ⁽¹⁾=Q ₃ ⁽²⁾=Q ₃ ⁽³⁾=Q ₃ ⁽⁴⁾=1350m ³/ s, downstream absorption basin depth of water H=30m, the first order and second level water stock incident angle are a ₁=a ₂=45 °, third layer water stock incident angle is a ₃=30 °, fore-and-aft distance L when each layer current enter absorption basin _iaccording to L _i– Hcot (a _i)+Hcot (a _i+ ₁)=50 meter, are designed to L ₁=50 meters, L ₂=28 meters, the first order each water stock lateral separation is spaced apart 30 meters, and the second level each water stock lateral separation is spaced apart 50 meters, and the third level each water stock lateral separation is spaced apart 20 meters.

Claims (5)

1., for choosing a classification flow configuration energy dissipating method for flowing water stock, it is characterized in that the method is that the water stock of multiple outlet structure escape works flip shot is increased layout along longitudinal classification of absorption basin step by step by flow, the water stock spacing between level and level meets L _i– H cot (a _i)+H cot (a _i+1)>=20 meter, the flow transversely with one-level each flip shot water stock is equal, the spacing L between each flip shot water stock _i ^(j)be at least 20 meters, wherein H is the depth of water in absorption basin, a _ifor water stock at different levels enters the incident angle of absorption basin.

2. the classification flow configuration energy dissipating method for choosing flowing water stock according to claim 1, is characterized in that the water stock of flip shot is divided into 1 grade, 2 grades, 3 grades along longitudinal classification of absorption basin by the method ... i level ... n level, the flow of every grade of current counts Q ₁, Q ₂, Q ₃q _iq _n, and adjacent next stage water flow is 1.5 ~ 2 times of upper level flow, i.e. Q _i=(1.5 ~ 2) Q _i-1.

3. the classification flow configuration energy dissipating method for choosing flowing water stock according to claim 1 and 2, is characterized in that the spacing between the level described in the method and level meets L _i– H cot (a _i)+H cot (a _i+1)=20 ~ 50 meter.

4. the classification flow configuration energy dissipating method for choosing flowing water stock according to claim 1 and 2, is characterized in that transversely counting Q with the flow of one-level each flip shot water stock described in the method _i ⁽¹⁾, Q _i ⁽²⁾, Q _i ⁽³⁾q _i ^(j), its flow is equal, i.e. Q _i ^(j)=Q _i ^(j+1), and Q _i ⁽¹⁾+ Q _i ⁽²⁾+ Q _i ⁽³⁾+ ... + Q _i ^(j)=Q _i, the spacing L between each flip shot water stock _i ^(j)it is 20 ~ 50 meters.

5. the classification flow configuration energy dissipating method for choosing flowing water stock according to claim 3, is characterized in that transversely counting Q with the flow of one-level each flip shot water stock described in the method _i ⁽¹⁾, Q _i ⁽²⁾, Q _i ⁽³⁾q _i ^(j), its flow is equal, i.e. Q _i ^(j)=Q _i ^(j+1), and Q _i ⁽¹⁾+ Q _i ⁽²⁾+ Q _i ⁽³⁾+ ... + Q _i ^(j)=Q _i, the spacing L between each flip shot water stock _i ^(j)it is 20 ~ 50 meters.