CN109098152B - A kind of anti-aircraft facility for stepped overflow dam - Google Patents
A kind of anti-aircraft facility for stepped overflow dam Download PDFInfo
- Publication number
- CN109098152B CN109098152B CN201810825615.6A CN201810825615A CN109098152B CN 109098152 B CN109098152 B CN 109098152B CN 201810825615 A CN201810825615 A CN 201810825615A CN 109098152 B CN109098152 B CN 109098152B
- Authority
- CN
- China
- Prior art keywords
- vent
- ladder
- pipes
- transition
- cavitation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02B—HYDRAULIC ENGINEERING
- E02B8/00—Details of barrages or weirs ; Energy dissipating devices carried by lock or dry-dock gates
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02B—HYDRAULIC ENGINEERING
- E02B8/00—Details of barrages or weirs ; Energy dissipating devices carried by lock or dry-dock gates
- E02B8/06—Spillways; Devices for dissipation of energy, e.g. for reducing eddies also for lock or dry-dock gates
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Barrages (AREA)
- Hydraulic Turbines (AREA)
Abstract
The invention discloses an anti-cavitation facility of a step overflow dam, which utilizes a flaring gate pier to increase the compression capacity to water flow, transversely contracts and vertically stretches the downward discharge water flow, and shoots the downward discharge water flow to the downstream, and strands of projecting water tongues are aerated and collided in the air so as to dissipate energy; the step behind the cavity is just the falling point of the front edge of the nappe, and the dissipation of the step on the drainage energy is accelerated by utilizing the friction resistance effect of the step on water flow; and then further energy dissipation is realized by utilizing the reverse arc section and the stilling basin, and the combined flood discharge and energy dissipation structure of the subsection and the subareas is utilized, so that the cavitation erosion and cavitation damage of the overflow dam surface is reduced, and the energy dissipation rate is improved.
Description
Technical Field
The invention relates to an anti-cavitation facility of a step overflow dam, and belongs to the field of anti-cavitation ventilation of steps under high water heads and large single wide flow.
Background
The increasing single-wide flow of flood discharge is a characteristic of high dam construction in China and is a trend of high dam construction development in future. The single wide flow of the Tuo stream hydropower station constructed in the 60 s reaches 143.2 m3(s.m), the maximum single wide flow of an Ankang hydropower station constructed in the 70 s reaches 282.7 m3(s · m), as for some hydro-junction projects of the 90 s to date, the single wide flow rate is increasing or decreasing. The increase of single wide flow of flood discharge can reduce the construction cost, but can also cause cavitation erosion problem of the high dam flood discharge building. From the applied engineering, for example, the sea water power station is damaged by the cavitation and cavitation erosion along the step caused by large single-width and high-speed flow in less than half a year of operation; after the Fujian Shuidong power station is put into operation, the step surface is slightly damaged. Therefore, under the conditions of high water head and large single wide flow, the cavitation and cavitation erosion problem and the solution of the integrated energy dissipater of the flaring pier, the stepped overflow dam and the stilling pool are the key problems of the current research.
According to the existing engineering practice and countless tests, aeration corrosion reduction is the most effective and economical method for preventing cavitation corrosion damage of the step overflow dam. Experimental research shows that when the aeration concentration in the water body reaches about 2%, the aeration effect is obviously improved, the possibility of cavitation erosion damage is greatly reduced, and when the aeration concentration reaches about 7%, the cavitation erosion damage can be completely avoided. Therefore, the efficient aeration facility has certain significance for avoiding cavitation damage of the step overflow dam and ensuring safe operation of hydraulic and hydroelectric engineering. According to the research of the integrated energy dissipater of the X-type flaring pier, the step and the stilling pool of the Guizhou cable-stayed hydropower station, the cavitation phenomenon is found at the junction of the first-stage step vertical surface and the overflow dam surface, and the fact that the air doping amount of the integrated energy dissipater on the overflow dam surface does not meet the requirement is shown. Therefore, the aeration concentration should be properly increased at the junction of the first-stage step vertical surface and the overflow dam surface to reduce the possibility of cavitation damage.
Disclosure of Invention
The invention provides an anti-cavitation facility of a stepped overflow dam, which is used for solving the problem of cavitation at the junction of a first-stage step vertical face and an overflow dam face.
The technical scheme of the invention is as follows: an anti-cavitation facility for a stepped overflow dam comprises a transition step 52, a side wall vent pipe 12;
transition ladder 52 comprises the two-stage ladder, and the first grade ladder of transition ladder 52 connects the 3 pier tails of wide tail mound of ladder overflow dam, and the even ladder 6 of second grade ladder connection of transition ladder 52, three kinds of structures are adopted in transition ladder 52's anti-cavitation design:
the first structure is as follows: a row of vent pipes 57 are arranged behind the vertical surfaces of the two steps of the transition step 52, one ends of the vent pipes 57 penetrate through the vertical surfaces of the steps, the other ends of the vent pipes 57 are communicated with the vent main pipes 56, one ends of the two vent main pipes 56 are communicated through the communication pipes, the other end of one vent main pipe 56 in the two vent main pipes 56 is closed, and the other end of the other vent main pipe 56 is communicated with the atmosphere through the side wall vent pipe 12;
the second structure is as follows: the outer sides of the vertical surfaces of the two steps of the transition step 52 are provided with steel plate protective surfaces, vent holes 54 are arranged at equal intervals, a rectangular transverse vent pipe 53 is arranged behind the vertical surface of the step and communicated with the vent holes 54, the rectangular transverse vent pipe 53 is directly formed by pouring behind the step, and two ends of the rectangular transverse vent pipe 53 are respectively communicated with the atmosphere through side wall vent pipes 12;
a third structure: the outside of the vertical surface of the two steps of the transition step 52 is provided with a steel plate protective surface, the vertical surface of the two steps is provided with vent holes 54 at equal intervals, a semicircular vent transverse pipe 55 is arranged behind the vertical surface of the steps and communicated with the vent holes 54, the semicircular vent transverse pipe 55 is directly formed by pouring behind the steps, and the two ends of the semicircular vent transverse pipe 55 are respectively communicated with the atmosphere through side wall vent pipes 12.
The transition ladder 52 is connected with the pier tail of the flaring gate pier 3 through the flip bucket 51.
The angle theta of the flip bucket 51 is more than or equal to 8 degrees and less than or equal to 11.3 degrees.
The invention has the beneficial effects that:
1. the compression capacity of the flaring gate pier is increased, the downward discharge water flow is transversely contracted and vertically stretched and is shot to the downstream, the strands of shot water tongues are aerated and collided in the air, so that energy is dissipated, the downward discharge water flow can be shot away from the overflow surface by the aid of the flip bucket arranged at the tail of the flaring gate pier, so that an aerated cavity is formed, external air is mixed into the cavity by the aid of the cavitation-proof transition step, negative pressure at the joint of the flip bucket and the transition step is greatly reduced, aeration concentration in the step is improved, and cavitation damage possibility is reduced; the step behind the cavity is just the falling point of the front edge of the nappe, and the dissipation of the step on the drainage energy is accelerated by utilizing the friction resistance effect of the step on water flow; and then further energy dissipation is realized by utilizing the reverse arc section and the stilling basin, and the combined flood discharge and energy dissipation structure of the subsection and the subareas is utilized, so that the cavitation erosion and cavitation damage of the overflow dam surface is reduced, and the energy dissipation rate is improved.
2. The transition ladder is used for mixing outside air to generate a stable aeration cavity, and the aeration concentration in the ladder is increased. Therefore, the possibility of cavitation damage to the joint part of the flip bucket and the transition step is greatly reduced, the service life of the building is prolonged, and the safe operation of hydraulic engineering is facilitated.
3. The transition ladder has simple structure, is directly poured behind the ladder, is simple and convenient to construct and has low cost.
Drawings
FIG. 1 is a side view of the present invention;
FIG. 2 is an enlarged view of a portion of FIG. 1 of the present invention;
FIG. 3 is a water surface line drawing of the overflow dam of the present invention;
FIG. 4 is a side wall vent pipe construction of the present invention;
FIG. 5 is a partial top view of the present invention;
FIG. 6 is a schematic view of a first configuration of the transition step of the present invention;
FIG. 7 is a schematic view of a second configuration of the transition step of the present invention;
FIG. 8 is a schematic view of a third configuration of the transition step of the present invention;
the reference numbers in the figures are: 1-dam body, 2-gate, 3-flaring pier, 4-overflow side wall, 5-cavitation prevention facility of step overflow dam, 51-flip bucket, 52-transition step, 53-rectangular horizontal ventilation pipe, 54-vent hole, 55-semicircular horizontal ventilation pipe, 56-main ventilation pipe, 57-vent pipe, 6-uniform step, 7-reverse arc section, 8-stilling basin, 9-stilling bucket, 10-left and right side wall water surface line, 11-aeration cavity and 12-side wall vent pipe.
Detailed Description
The invention will be further described with reference to the following figures and examples, without however restricting the scope of the invention thereto.
Example 1: an anti-cavitation facility 5 of a step overflow dam is applied to hydraulic and hydroelectric junction engineering, the length of the dam crest of the power station is 482 m, the maximum dam height is 132 m, and the single-width flow is 150-200 m3In the flood discharge and energy dissipation building of/s.m. Flood discharge energy dissipation building comprises left bank overflow table hole and flood discharge sand washing bottom hole, and overflow table hole number is 5 holes, and the drill way size is 13m x 20 m, adopts the integrated flood discharge energy dissipation mode of "flaring mound + ladder + stilling pond", adopts the WES weir type, connects 1 after: the dam face of the slope section of 0.75 has 29 steps, the height of the steps is 1m, the width of the steps is 0.75 m, the slope of the dam face is 53 degrees, and the reverse arc section and the stilling pool are connected downwards.
The structure is shown in fig. 6: the double-step flip bucket comprises a flip bucket 51 (the flip bucket takes the connecting line of the convex tops of the uniform steps as a datum line, takes the vertical top position of the first step as a starting point, vertically and upwards increases 1m to be used as the fixed height of the flip bucket, and forms an angle theta with the datum line) and a transition step 52 which are arranged behind the flaring pier 3. The flip bucket 51 is in a triangular shape, the angle theta of the flip bucket is more than or equal to 8 degrees and less than or equal to 11.3 degrees, 3 specific angles are selected in the embodiment, the specific angles are respectively 8 degrees, 10 degrees and 11.3 degrees, the height h =1m, the transition ladder is composed of 2 large steps with the height of 2m and the width of 1.5m, a row of vent pipes 57 are arranged behind the vertical surfaces of the two steps of the transition ladder 52, one end of each vent pipe 57 penetrates through the vertical surface of the ladder, the other end of each vent pipe 57 is communicated with the vent main pipes 56, one end of each vent main pipe 56 is communicated through a communicating pipe, the other end of one vent main pipe 56 of the two vent main pipes 56 is closed, and the other end of the other vent main pipe 56 is; in the 1:60 model test, the main vent pipe 56 has a diameter of 2cm, the vent pipe 57 has a diameter of about 10mm, the spacing is 18cm, and the side wall vent pipe 12 has a diameter of 33.3 mm.
Test tests show that the flip bucket and anti-cavitation transition step combined energy dissipater in the embodiment can protect the joint of a WES curve section and the vertical face of a first-stage step, the aeration concentration is about 4.8%, cavitation and cavitation damage can be avoided, and the energy dissipation rate is about 65%.
The 3 types of flip bucket 51 are combined with the transition step 52 to form the flip bucket + anti-cavitation transition step combination of the present invention, as shown in fig. 6.
Example 2: an anti-cavitation facility 5 of a step overflow dam is applied to hydraulic and hydroelectric junction engineering, the length of the dam crest of the power station is 482 m, the maximum dam height is 132 m, and the single-width flow is 100-150 m3In the flood discharge and energy dissipation building of/s.m. Flood discharge energy dissipation building comprises left bank overflow table hole and flood discharge sand washing bottom hole, and overflow table hole number is 5 holes, and the drill way size is 13m x 20 m, adopts the integrated flood discharge energy dissipation mode of "flaring mound + ladder + stilling pond", adopts the WES weir type, connects 1 after: the dam face of the slope section of 0.75 has 29 steps, the height of the steps is 1m, the width of the steps is 0.75 m, the slope of the dam face is 53 degrees, and the reverse arc section and the stilling pool are connected downwards.
The structure is shown in fig. 7 and 8: including a flip bucket 51 and a novel transition step 52 disposed behind the flaring gate 3. The flip bucket 51 is in a triangular shape, the angle theta is more than or equal to 8 degrees and less than or equal to 11.3 degrees, 3 specific angles are selected in the embodiment, the specific angles are respectively 8 degrees, 10 degrees and 11.3 degrees, the height h =1m, the transition ladder is composed of 2 large steps with the height of 2m and the width of 1.5m, a steel plate protective surface is arranged on the outer side of the vertical surface of the two steps of the transition ladder 52, vent holes 54 are arranged at equal intervals, a rectangular transverse ventilation pipe 53/a semicircular transverse ventilation pipe 55 (the section is rectangular or semicircular, the rectangular transverse ventilation pipe 53/the semicircular transverse ventilation pipe 55 is arranged behind the vertical surface of the ladder and is communicated with the vent holes 54, the rectangular transverse ventilation pipe 53/the semicircular transverse ventilation pipe 55 are directly poured behind the ladder, and the two ends of the rectangular transverse ventilation pipe 53/the semicircular transverse ventilation pipe 55 are respectively communicated with the atmosphere through the; in the 1:60 model test, the diameter of the semicircular horizontal vent pipe 55 is 33.3mm, the cross-sectional dimension of the rectangular horizontal vent pipe 53 is 25mm multiplied by 33.3mm, and the diameter of the side wall vent pipe 12 is 33.3 mm.
Test tests show that the flip bucket and anti-cavitation transition step combined energy dissipater in the embodiment can protect the joint of a WES curve section and the vertical face of a first-stage step, the aeration concentration reaches about 4%, and cavitation erosion and cavitation damage are avoided; the energy consumption rate is about 60 percent.
The working principle of the invention is as follows:
when the overflow dam discharges flood, firstly opening a gate 2 of a gate pier (the combined inlet of the gate pier and a flaring pier is larger than a gate chamber of an outlet, the flaring pier can be used for increasing the compression capacity of the water flow to transversely contract and vertically stretch the downward water flow), the downward water flow flows out of the gate chamber, transversely contracts through the flaring pier 3 to form a water tongue erected longitudinally, then is separated from an overflow surface through a flip bucket 51 at the tail part of the flaring pier 3 to form a water-free area on the overflow dam surface, and is combined with a transition step 52 with a ventilation structure, the transition step 52 is used for changing the aeration concentration, and in addition, a side wall vent pipe 12 is used for mixing the outside air to improve the aeration concentration, so that a stable aeration cavity 11 is generated, the cavitation damage is reduced, the area of the overflow dam surface which is easy to suffer from cavitation erosion is protected, then the bottom of the lifted water tongue falls into a uniform step 6 behind the cavity, and the step has the rolling and friction effects on the step, thereby forming sliding water flow and playing a role of water cushion on the rear edge of the nappe so as to accelerate the energy dissipation of the downward-discharging water flow, the rear edge of the nappe falls into the reverse arc section 7 and the front section of the stilling pool 8 to form water jump and simultaneously generate backflow, and the energy dissipation is realized under the combined action of the two; further through the energy dissipation of the stilling basin and the water blocking effect of the stilling threshold 9, the energy is dissipated again.
While the present invention has been described in detail with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art.
Claims (1)
1. The utility model provides an anti-cavitation facility of ladder overflow dam which characterized in that: comprises a transition step (52) and a side wall vent pipe (12);
transition ladder (52) comprise the two-stage ladder, and wide tail mound (3) pier tail of the first grade ladder connection ladder overflow dam of transition ladder (52), the even ladder (6) of second grade ladder connection of transition ladder (52), the anti-cavitation design of transition ladder (52) adopts three kinds of structures:
the first structure is as follows: a row of vent pipes (57) are arranged behind the vertical surfaces of the two stages of the transition ladder (52), one ends of the vent pipes (57) penetrate through the vertical surfaces of the stages, the other ends of the vent pipes (57) are communicated with the main vent pipes (56), one ends of the two main vent pipes (56) are communicated through the communicating pipes, the other end of one main vent pipe (56) of the two main vent pipes (56) is closed, and the other end of the other main vent pipe (56) is communicated with the atmosphere through the side wall vent pipe (12);
the second structure is as follows: the outer sides of the vertical surfaces of two stages of the transition steps (52) are provided with steel plate protective surfaces, vent holes (54) are arranged at equal intervals, rectangular transverse vent pipes (53) are arranged behind the vertical surfaces of the steps and communicated with the vent holes (54), the rectangular transverse vent pipes (53) are directly formed by pouring behind the steps, and two ends of each rectangular transverse vent pipe (53) are respectively communicated with the atmosphere through side wall vent pipes (12);
a third structure: the outer sides of the vertical surfaces of two stages of the transition steps (52) are provided with steel plate protective surfaces, vent holes (54) are arranged at equal intervals, semicircular vent transverse pipes (55) are arranged behind the vertical surfaces of the steps and communicated with the vent holes (54), the semicircular vent transverse pipes (55) are directly formed by pouring behind the steps, and two ends of each semicircular vent transverse pipe (55) are respectively communicated with the atmosphere through side wall vent pipes (12);
the transition ladder (52) is connected with the pier tail of the flaring pier (3) through the flip bucket (51);
the angle theta of the flip bucket (51) is more than or equal to 8 degrees and less than or equal to 11.3 degrees.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810825615.6A CN109098152B (en) | 2018-07-25 | 2018-07-25 | A kind of anti-aircraft facility for stepped overflow dam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810825615.6A CN109098152B (en) | 2018-07-25 | 2018-07-25 | A kind of anti-aircraft facility for stepped overflow dam |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109098152A CN109098152A (en) | 2018-12-28 |
| CN109098152B true CN109098152B (en) | 2020-04-03 |
Family
ID=64847461
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810825615.6A Active CN109098152B (en) | 2018-07-25 | 2018-07-25 | A kind of anti-aircraft facility for stepped overflow dam |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109098152B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109555088B (en) * | 2019-01-14 | 2023-11-07 | 中国水利水电科学研究院 | A rectification and anti-vortex device |
| CN112281767B (en) * | 2020-09-27 | 2021-11-19 | 广东粤源工程咨询有限公司 | Dam spillway structure and construction method thereof |
| CN113638376A (en) * | 2021-08-16 | 2021-11-12 | 长江勘测规划设计研究有限责任公司 | Open deflector with access steps |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3760340B2 (en) * | 2001-08-27 | 2006-03-29 | 章雄 飯田 | Inundation prevention gate |
| CN100572680C (en) * | 2008-03-11 | 2009-12-23 | 水利部交通部电力工业部南京水利科学研究院 | A kind of natural ventilation method of reducing or remitting the ship lock valve segment sudden enlarging body type ridge dropping cavitation |
-
2018
- 2018-07-25 CN CN201810825615.6A patent/CN109098152B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109098152A (en) | 2018-12-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100554593C (en) | Doped gas device preposed ladder energy dissipater | |
| CN207003391U (en) | A kind of water gate energy-dissipating installation | |
| CN101349047A (en) | Air-entrained curve ladder energy dissipator in the flood discharge tunnel | |
| CN107022987B (en) | High dam overflow surface jet control structure | |
| CN202073075U (en) | Discontinuous convex type step energy dissipater | |
| CN109098152B (en) | A kind of anti-aircraft facility for stepped overflow dam | |
| CN103498451B (en) | Impact type combination underflow energy dissipator structure | |
| CN102900054A (en) | River bank-like flood spillway | |
| CN112921916A (en) | Abrupt slope energy dissipation facility | |
| CN101538840B (en) | deflected flow energy dissipator in the stilling basin | |
| CN2488960Y (en) | Energy dissipation and flood discharge for large dam in new type of diffusion mode | |
| CN103266584B (en) | A kind of hydraulic engineering energy dissipating construction | |
| CN207331645U (en) | A kind of overfall dam chosen bank and novel transition step and combined | |
| CN110528475A (en) | A kind of hydraulic engineering water intake system | |
| CN103669301B (en) | The height bank absorption basin of double-layer disperse energy dissipating | |
| CN217710604U (en) | Expanding Step Spillway | |
| CN102704447B (en) | V-shaped step energy dissipater with transition section | |
| CN204982814U (en) | Power that disappears structure in low water head dam low reaches riverbed | |
| CN204418136U (en) | There is pressure sudden enlargement and sudden Circular Jet energy dissipater | |
| CN213682028U (en) | Combined energy dissipating work of energy dissipating piers in the bottom flow energy dissipating pool of the diffuser chute | |
| CN103981842B (en) | Trapezoidal contraction outlet X-type flaring gate pier | |
| CN220266475U (en) | Water flow opposite-flushing energy dissipation type flood discharge steep tank | |
| CN107476262A (en) | A kind of plagiohedral ladder energy dissipater on overfall dam | |
| CN206971181U (en) | A kind of multichannel bank stiling basin of dispersible energy dissipating | |
| CN216130077U (en) | Combined type flow-picking energy dissipation device suitable for narrow riverbed |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |