Energy dissipation and flood discharge emptying cavity for high water head

Abstract

The invention discloses an energy dissipation and flood discharge emptying cavity, particularly discloses an energy dissipation and flood discharge emptying cavity for a high water head, and belongs to the technical field of design and manufacturing of water conservancy and hydropower engineering structures. According to the energy dissipation and flood discharge emptying cavity for the high water head, energy carried by discharged water flow can be effectively reduced, and scouring of the discharged water flow to an outlet section emptying cavity is relieved. The energy dissipation and flood discharge emptying cavity comprises an inlet section, a pressure section, a control structure and an outlet section, the elevation of a water inlet of the inlet section is lower than that of a dead water level of a reservoir, the inlet section, the pressure section, the control structure and a part of the outlet section are all located in a rock mass, and the energy dissipation and flood discharge emptying cavity further comprises a rotational flow energy dissipation connecting system. The inlet end of the rotational flow energy dissipation connecting system is connected with the control structure, and the outlet end of the rotational flow energy dissipation connecting system is connected with the outlet section.

Description

Technical Field

[0001] The invention relates to an energy dissipation flood discharge and emptying hole, in particular to an energy dissipation flood discharge and emptying hole used for high water head, and belongs to the technical field of design and construction of water conservancy and hydropower engineering structures. Background Art

[0002] Explanation of terms

[0003] 1) Normal water level: the highest water level allowed to be stored in a reservoir under normal operation to meet the needs of power generation and other benefits;

[0004] 2) Dead water level: The lowest water level allowed to be drawn down by beneficial dispatching under normal operation of the reservoir.

[0005] 3) Flood discharge and emptying hole: Flood discharge and emptying hole is a commonly used discharge structure in pumped storage power stations. Its main functional requirements include:

[0006] a) Pre-discharge of flood water, that is, discharge the upstream flow and ensure the safety of the dam. For the lower reservoir of a pumped storage power station, it is necessary to discharge the upstream flow of the lower reservoir to the downstream of the dam as much as possible to avoid the upstream flow raising the water level of the lower reservoir and reducing the generating head of the pumped storage power station (the water level difference between the upper and lower reservoirs); on the other hand, since the lower reservoir of a pumped storage power station is mostly located on a river tributary, the upstream flow is relatively small, and it should be avoided to discharge excess water that exceeds the upstream flow to the downstream of the dam to ensure that the lower reservoir has sufficient water for power generation.

[0007] In summary, for the flood discharge and emptying hole of the lower reservoir of the pumped storage power station, the flow discharged to the downstream of the dam should be neither too much nor too little, but should be exactly equal to the flow from the upstream. Since the flow from the upstream of the river tributaries varies greatly and the change duration is short, the discharge flow from the flood discharge and emptying hole varies greatly and the gate (valve) is frequently operated.

[0008] b) Emptying, that is, according to the requirements of the maintenance of the lower reservoir, the inlet and outlet, the reservoir water level is lowered and the storage capacity is reduced. In order to meet the requirements of the emptying function, the elevation of the flood discharge and emptying hole must be set lower than the dead water level of the lower reservoir.

[0009] 4) Branch pipe: When a water pipe (drain pipe) is divided into two or more water pipes (drain pipes), a branch pipe is required.

[0010] 5) Cone valve: Cone valve is a working valve that adjusts the flow rate by changing the distance between the movable valve sleeve and the fixed cone. It is generally installed at the outlet of the high-pressure drainage pipe. Cone valve has good flow control effect, simple structure and easy operation. According to different outlet types, cone valves can be divided into submerged outflow type and air discharge type.

[0011] It should be noted that from the perspective of equipment manufacturing and prevention of cavitation and cavitation erosion, the diameter of the cone valve should not exceed 3.0m and the outflow velocity should not exceed 22m / s.

[0012] For high-head flood discharge and emptying holes, the existing layout plans and main problems are as follows:

[0013] The current layout of the existing high-head flood discharge and emptying holes is as follows:

[0014] 1) From upstream to downstream, the flood discharge and emptying tunnel consists of an inlet section, a pressure section, a gate section, a non-pressure section and an outlet section;

[0015] 2) The elevation of the inlet section is set lower than the dead water level of the reservoir;

[0016] 3) From upstream to downstream, the gate section is equipped with 1 maintenance gate, 1 emergency gate and 1 working arc gate in sequence;

[0017] 4) The pressure-free section consists of the upper flat section, the inclined well section and the lower flat section;

[0018] 5) The outlet section is equipped with a raft to divert water to the downstream riverbed to avoid erosion of the outlet section foundation.

[0019] The main problems of existing high-head flood discharge and emptying holes include:

[0020] 1) The flood discharge and emptying hole adopts working arc gate to control the discharge. The working arc gate has a prominent gate vibration problem when the opening is small, and the operation process is cumbersome, which cannot meet the requirements of small flow flood discharge and frequent gate operation;

[0021] 2) Due to the high working head and high outflow velocity, cavitation and erosion problems are prominent in the non-pressure section (especially the lower flat section and inclined well section) and the outlet section;

[0022] 3) When discharging a small flow, the outlet embankment cannot carry the water to the downstream riverbed far away from the foundation of the outlet section, and the outlet section has obvious scouring problems;

[0023] 4) When discharging a large flow, due to the high working water head and low energy dissipation rate of water flow in the flood discharge and emptying hole, most of the kinetic energy converted from potential energy is still retained after passing through the outlet embankment. When the geological conditions of the downstream river channel are poor and the anti-scouring ability is weak, it may cause serious scouring to the downstream river channel and bank slopes. Summary of the invention

[0024] The technical problem to be solved by the present invention is to provide an energy dissipation flood discharge hollowing hole for high water head which can effectively dissipate the energy carried by the downstream water flow and reduce the scouring of the outlet hollowing hole by the downstream water flow.

[0025] The technical solution adopted to solve the above technical problems is: an energy dissipation, flood discharge and emptying cave for high water head, including an inlet section, a pressure section, a control structure and an outlet section, the elevation of the water inlet of the inlet section is lower than the elevation of the dead water level of the reservoir, the inlet section, the pressure section, the control structure and a part of the outlet section are all located in the rock mass, the energy dissipation, flood discharge and emptying cave also includes a vortex energy dissipation connection system, the inlet end of the vortex energy dissipation connection system is connected to the control structure, and the outlet end of the vortex energy dissipation connection system is connected to the outlet section.

[0026] Furthermore, the control structure includes a maintenance gate and its installation mechanism, an emergency gate and its installation mechanism and a gate hoist. The installation mechanism of the maintenance gate and the installation mechanism of the emergency gate are arranged in sequence along the water delivery direction between the pressurized section and the swirl energy dissipation connection system. The maintenance gate and the emergency gate arranged in the corresponding installation mechanism are opened or closed respectively by the corresponding gate hoist.

[0027] The preferred embodiment of the above scheme is that each installation mechanism includes a gate chamber shaft and a gate control room arranged at the top of the gate chamber shaft, the hoist is arranged in the gate control room, and a steel lining section is also provided at the end of the bottom of the gate chamber shaft of the accident gate along the water conveyance direction, and the end of the steel lining section is connected to the inlet end of the vortex energy dissipation connection system.

[0028] Furthermore, the gate control room of the maintenance gate and the gate control room of the accident gate are an integrated structure, and the control structure also includes a traffic air supply tunnel connected to the ground. One end of the traffic air supply tunnel is located in the rock mass and is connected to the gate control room. An erosion vent hole connected to the bottom end of the accident gate chamber shaft is also provided in the side wall on the downstream side of the accident gate chamber shaft, and the upper end of the erosion vent hole is connected to the gate control room.

[0029] The preferred embodiment of the above scheme is that the swirl energy dissipation connection system includes an outlet energy dissipation structure, a swirl energy dissipation structure and a water-return energy dissipation conveying structure. The outlet energy dissipation structure, the swirl energy dissipation structure and the water-return energy dissipation conveying structure are sequentially connected along the water conveyance direction. The end of the bottom of the vertical shaft of the emergency gate chamber is connected to the outlet energy dissipation structure through a steel lining section, and the end of the water-return energy dissipation conveying structure is connected to the input end of the outlet section.

[0030] Furthermore, the outlet energy dissipation structure includes a valve chamber and an energy dissipation pool connected in sequence, the input end of the valve chamber is connected to the output end of the steel liner section, and the output end of the energy dissipation pool is connected to the swirl energy dissipation structure.

[0031] A preferred embodiment of the above scheme is that the valve chamber includes a valve chamber body, a drainage main pipe, a branch pipe, at least two drainage branch pipes, a plurality of submerged cone valves equal in number to the drainage branch pipes, and a middle partition wall; the output ends of the drainage branch pipes supported on the middle partition wall are respectively and simultaneously connected to the drainage main pipe through the branch pipes; a submerged cone valve is respectively installed at the end of each drainage branch pipe, and each submerged cone valve is respectively submerged in the energy dissipation pool; an overflow weir is also provided at the output end of the energy dissipation pool, and the swirl energy dissipation structure is connected to the energy dissipation pool through the overflow weir; and a traffic air supply hole connected to the ground is also provided on the side wall of the valve chamber body.

[0032] Furthermore, the vortex energy dissipation structure includes an energy dissipation pool connecting section, a nest chamber, a vortex shaft, a connecting shaft and an energy dissipation well. The input end of the energy dissipation pool connecting section is connected to the energy dissipation pool through an overflow weir, the output end of the energy dissipation pool connecting section is connected to the top of the nest chamber, the connecting shaft is connected to the nest chamber from the bottom through the vortex shaft, the energy dissipation well is vertically arranged at the bottom of the connecting shaft, and the water withdrawal energy dissipation conveying structure is connected to the top of the energy dissipation well horizontally or inclined from the side.

[0033] A preferred embodiment of the above scheme is that the water retreat and energy dissipation conveying structure includes an energy dissipation orifice plate and a horizontally or inclined water pipe, at least two groups of energy dissipation orifices are arranged on the water pipe at intervals along the water conveying direction, the input end of the water pipe is connected to the energy dissipation well horizontally or inclined from the side, and the output end of the water pipe is connected to one end of the outlet section located in the rock mass.

[0034] Furthermore, the energy dissipation well includes an energy dissipation well body and a connecting flat tunnel, the connecting flat tunnel is arranged horizontally or obliquely on the top of the energy dissipation well body from the side, a pressure slope toward the downstream is arranged on the top of the connecting flat tunnel, and the downstream end of the connecting flat tunnel is connected to the input end of the water pipe through the expansion body;

[0035] A stepped energy dissipation subsection, a concrete tooth groove subsection and a block stone backfill subsection are sequentially arranged on the exit section outside the rock body.

[0036] The beneficial effects of the present invention are as follows: the technical solution provided by the present application is based on the existing drainage hole including an inlet section, a pressure section, a control structure and an outlet section, and combined with the structural characteristics that the elevation of the water inlet of the inlet section is lower than the elevation of the dead water level of the reservoir, the inlet section, the pressure section, the control structure and a part of the outlet section are all located in the rock mass. By adding a vortex energy dissipation connection system to form the energy dissipation flood discharge drainage hole of the present application, and then the inlet end of the vortex energy dissipation connection system is connected to the control structure, and the outlet end of the vortex energy dissipation connection system is connected to the outlet section, so as to achieve the energy carried by the discharged water flow of the drainage hole before the water flow enters the outlet section through the vortex energy dissipation connection system to be eliminated as much as possible, so as to achieve the purpose of reducing the serious scouring of the outlet section drainage hole by the discharged water flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the longitudinal section structure of an existing drain hole involved in the energy dissipation and flood discharge drain hole with high water head of the present invention;

[0038] Figure 2 It is a schematic diagram of the longitudinal section structure of the energy dissipation, flood discharge and emptying cave for high water head of the present invention;

[0039] Figure 3 It is a detailed layout diagram of the control structure involved in the energy dissipation flood discharge and hollowing hole for high water head of the present invention;

[0040] Figure 4 It is a detailed layout diagram of the energy dissipation pool involved in the high-head energy dissipation flood discharge and emptying hole of the present invention;

[0041] Figure 5 It is a detailed layout diagram of the energy dissipation well involved in the energy dissipation flood discharge and hollowing hole for high water head of the present invention;

[0042] Figure 6 The invention is a detailed layout diagram of the outlet section involved in the energy dissipation, flood discharge and hollowing hole for high water head.

[0043] Marked in the figure are: inlet section 1, pressurized section 2, outlet section 3, maintenance gate 4, emergency gate 5, hoist 6, gate chamber shaft 7, gate control room 8, steel lining section 9, traffic air supply tunnel 10, erosion vent 11, energy dissipation pool 12, valve chamber body 13, discharge main pipe 14, branch pipe 15, discharge branch pipe 16, submerged cone valve 17, middle partition wall 18, overflow weir 19, energy dissipation pool connection section 20, nest chamber 21, swirl shaft 22, connecting shaft 23, energy dissipation orifice 24, water pipe 25, energy dissipation well body 26, connecting flat tunnel 27, stepped energy dissipation sub-section 28, concrete tooth groove sub-section 29, block stone backfill sub-section 30. DETAILED DESCRIPTION

[0044] like Figure 1 to Figure 6The present invention shows an energy dissipation flood discharge hole for high water head, which can effectively reduce the energy carried by the downstream water flow and reduce the scouring of the outlet section discharge hole by the downstream water flow. The energy dissipation flood discharge hole includes an inlet section 1, a pressure section 2, a control structure and an outlet section 3. The elevation of the water inlet of the inlet section is lower than the elevation of the dead water level of the reservoir. The inlet section 1, the pressure section 2, the control structure and a part of the outlet section 3 are all located in the rock mass. The energy dissipation flood discharge hole also includes a vortex energy dissipation connection system. The inlet end of the vortex energy dissipation connection system is connected to the control structure, and the outlet end of the vortex energy dissipation connection system is connected to the outlet section 3. The technical solution provided by the present application is based on the existing drainage hole including an inlet section, a pressure section, a control structure and an outlet section, and is combined with the structural characteristics that the elevation of the water inlet of the inlet section is lower than the elevation of the dead water level of the reservoir, and the inlet section, the pressure section, the control structure and a part of the outlet section are all located in the rock mass. By adding a vortex energy dissipation connection system, the energy dissipation flood discharge drainage hole of the present application is formed, and then the inlet end of the vortex energy dissipation connection system is connected to the control structure, and the outlet end of the vortex energy dissipation connection system is connected to the outlet section, so as to achieve the goal of eliminating the energy carried by the discharged water flow of the drainage hole as much as possible through the vortex energy dissipation connection system before the water flow enters the outlet section, so as to achieve the purpose of reducing the serious scouring of the outlet section drainage hole caused by the discharged water flow.

[0045] Combined with the existing technology, in order to achieve the maximum energy dissipation and facilitate the control of the downstream water flow, the control structure described in this application includes a maintenance gate 4 and its installation mechanism, an emergency gate 5 and its installation mechanism and a hoist 6. The installation mechanism of the maintenance gate 4 and the installation mechanism of the emergency gate 5 are arranged in sequence between the pressure section 2 and the swirl energy dissipation connection system along the water conveyance direction. The maintenance gate 4 and the emergency gate 5 arranged in the corresponding installation mechanism are opened or closed by the corresponding hoist 6. At this time, the preferred way is that each installation mechanism includes a gate chamber shaft 7 and a gate control room 8 arranged at the top of the gate chamber shaft, the hoist 6 is arranged in the gate control room 8, and a steel lining section 9 is also provided at the end of the bottom of the emergency gate gate chamber shaft along the water conveyance direction, and the end of the steel lining section 9 is connected to the inlet end of the swirl energy dissipation connection system. More specifically, the gate control room 8 of the maintenance gate 4 and the gate control room 8 of the accident gate 5 are an integrated structure, and the control structure also includes a traffic air supply tunnel 10 connected to the ground. One end of the traffic air supply tunnel 10 located in the rock mass is connected to the gate control room 8, and an erosion vent 11 connected to the bottom end of the accident gate chamber shaft is also provided in the side wall on the downstream side of the accident gate chamber shaft, and the upper end of the erosion vent 11 is connected to the gate control room 8.

[0046] Accordingly, as the key structure improved in the present application, in order to minimize the energy carried by the downstream water flow and to control the size of the water flow as much as possible to adapt to the current situation that the discharge hole of the pumped storage power station needs to be frequently opened and closed, the vortex energy dissipation connection system described in the present application includes an outlet energy dissipation structure, a vortex energy dissipation structure and a water-returning energy dissipation conveying structure. The outlet energy dissipation structure, the vortex energy dissipation structure and the water-returning energy dissipation conveying structure are sequentially connected along the water conveying direction. The end of the bottom of the vertical shaft of the accident gate chamber is connected to the outlet energy dissipation structure through the steel lining section 9, and the end of the water-returning energy dissipation conveying structure is connected to the input end of the outlet section 3. Specifically, the outlet energy dissipation structure of the present application includes a valve chamber and an energy dissipation pool 12 connected in sequence, the input end of the valve chamber is connected to the output end of the steel lining section 9, and the output end of the energy dissipation pool 12 is connected to the vortex energy dissipation structure. The vortex energy dissipation structure of the present application includes an energy dissipation pool connection section 20, a nest chamber 21, a vortex shaft 22, a connecting shaft 23 and an energy dissipation well. The input end of the energy dissipation pool connection section 20 is connected to the energy dissipation pool 12 through an overflow weir 19, the output end of the energy dissipation pool connection section 20 is connected to the top of the nest chamber 21, the connecting shaft 23 is connected to the nest chamber 21 from the bottom through the vortex shaft 22, the energy dissipation well is arranged vertically at the bottom of the connecting shaft 23, and the water retreat energy dissipation conveying structure is connected to the top of the energy dissipation well horizontally or obliquely from the side. The water retreat energy dissipation conveying structure of the present application includes an energy dissipation orifice plate 24 and a horizontally or obliquely arranged water pipe 25. At least two groups of energy dissipation orifice plates 24 are arranged on the water pipe 25 at intervals along the water conveying direction. The input end of the water pipe 25 is connected to the energy dissipation well horizontally or obliquely from the side, and the output end of the water pipe 25 is connected to an end of the outlet section 3 located in the rock mass.

[0047] Furthermore, the detailed structure of the valve chamber of the present application includes a valve chamber body 13, a drainage main pipe 14, a branch pipe 15, at least two drainage branch pipes 16, a plurality of submerged cone valves 17 and a middle partition wall 18 whose number is equal to the number of drainage branch pipes 16. The output ends of the drainage branch pipes 16 supported on the middle partition wall 18 are respectively connected to the drainage main pipe 14 through the branch pipe 15. A submerged cone valve 17 is respectively installed at the end of each drainage branch pipe 16. Each submerged cone valve 17 is respectively submerged in the energy dissipation pool 12. An overflow weir 19 is also provided at the output end of the energy dissipation pool 12. The vortex energy dissipation structure is connected to the energy dissipation pool 12 through the overflow weir 19. A traffic air supply hole 10 connected to the ground is also provided on the side wall of the valve chamber body 13. The detailed structure of the energy dissipation well of the present application includes an energy dissipation well body 26 and a connecting flat tunnel 27. The connecting flat tunnel 27 is arranged horizontally or obliquely at the top of the energy dissipation well body 26 from the side. A pressure slope toward the downstream is arranged at the top of the connecting flat tunnel 27. The downstream end of the connecting flat tunnel 27 is connected to the input end of the water pipe 25 through a sudden expansion body. In order to improve the anti-scouring ability of the outlet section, the present application sequentially arranges a stepped energy dissipation sub-section 28, a concrete tooth groove sub-section 29 and a block stone backfill sub-section 30 on the outlet section 3 located outside the rock body.

[0048] In summary, the above technical solution provided by this application also has the following advantages:

[0049] 1. Ability to adapt to larger upstream water level fluctuations. The elevation of the inlet section of the present invention is set lower than the dead water level of the reservoir, and the upstream flow can be discharged at any water level between the normal water storage level and the dead water level. While meeting the requirements of the emptying function, it can also use a larger upstream water level fluctuation;

[0050] 2. Able to adapt to large fluctuations in discharge flow. The present invention is provided with a bifurcated pipe, which can divide a main discharge pipe into multiple branch discharge pipes, and each branch discharge pipe is provided with a cone valve to control flood discharge; when the upstream flow is large, multiple branch discharge pipes can be opened to discharge floods together; when the upstream flow is small, one branch discharge pipe can be opened to fully or partially control discharge, thereby being able to adapt to the requirements of large fluctuations in discharge flow;

[0051] 3. Rapid adjustment of the discharge flow rate. The discharge branch pipe of the present invention adopts a cone valve for discharge control, which has a simple structure and is easy to operate. It can avoid the vibration problem of flood discharge when the arc gate has a small opening, and at the same time has the function of rapidly adjusting the discharge flow rate;

[0052] 4. Good internal energy dissipation effect. From upstream to downstream, the present invention sets up multiple internal energy dissipation settings, which have good internal energy dissipation effects:

[0053] 1) The cone valve itself has a certain energy dissipation effect and is the first internal energy dissipation facility;

[0054] 2) The cone valve discharges the upstream flow into the energy dissipation pool, causing shear and turbulence of the water flow inside the energy dissipation pool, which to a certain extent dissipates the kinetic energy of the water flow. This is the second internal energy dissipation facility;

[0055] 3) The water flows from the overflow weir, through the connection section and the swirl shaft, to the energy dissipation well, where it swirls and is fully aerated, and is fully sheared and turbulent in the energy dissipation well, which greatly dissipates the kinetic energy of the water flow. This is the third internal energy dissipation facility;

[0056] 4) Several orifice plates are set in the drainage tunnel section to further aerate, shear and turbulent the water flow, further dissipating the residual kinetic energy of the water flow. This is the fourth internal energy dissipation facility;

[0057] 5. The cavitation problem is not prominent. The present invention has set up a number of anti-cavitation measures and has good anti-cavitation ability:

[0058] 1) A vent is set downstream of the accident gate, with the outlet located at the top of the flow channel at the bottom of the lock chamber shaft, and the inlet located at the top of the lock chamber shaft. It can be connected to the surface through the accident gate control room and the lock chamber traffic tunnel and air supply tunnel, so that air can be replenished to the flow channel in time during the dynamic water closure of the accident gate, reducing the risk of cavitation in this part;

[0059] 2) The height difference between the normal water level and the dead water level of the lower reservoir of a pumped storage power station is generally not large. Although the elevation of the cone valve is set lower than the dead water level, it can ensure that its working water head meets the requirement that the outflow velocity is less than 22m / s, and the cavitation risk of the cone valve itself is not large;

[0060] 3) The cyclone shaft is connected to the top of the energy dissipation pool and can be connected to the ground surface through the energy dissipation pool and the energy dissipation pool traffic tunnel and air supply tunnel. The cyclone head in the cyclone shaft can be fully aerated to prevent the cyclone shaft, the energy dissipation pool connecting flat tunnel and other parts from cavitation damage;

[0061] 4) The present invention adopts a scheme of step-by-step energy dissipation by using multiple internal energy dissipation facilities. The water flow in the energy dissipation pool, vortex shaft, energy dissipation well, and water withdrawal tunnel section has passed through one to three internal energy dissipation facilities. The kinetic energy of the water has been dissipated to a certain extent, the flow velocity of the water is not large, and the cavitation and erosion problems are not prominent.

[0062] 6. The scouring of the downstream river channel is light, mainly reflected in:

[0063] 1) The present invention is equipped with four internal energy dissipation facilities, namely, energy dissipation pool, vortex shaft, energy dissipation well, and orifice plate of water withdrawal tunnel section. The kinetic energy of the water flow discharged through the flood discharge and emptying tunnel has been dissipated to a large extent, and the flow rate of the water flow discharged in the water withdrawal tunnel section is already relatively low;

[0064] 2) Step energy dissipation is set up at the outlet section, which can further dissipate the kinetic energy of the water flow in the drainage tunnel section and further reduce the flow velocity of the water entering the downstream river channel;

[0065] 3) The outlet section is equipped with concrete troughs and stone backfill sections to improve the anti-scouring capacity of the downstream river channel.

[0066] The technical solution of the present application is further described below through specific embodiments:

[0067] The technical problem to be solved by the present invention is to provide a high-head flood discharge and cavitation cavern that can adapt to larger upstream water level fluctuations, larger discharge flow fluctuations, can quickly adjust the discharge flow, has good internal energy dissipation effect, has no prominent cavitation and erosion problems, and has a multi-stage energy dissipation that causes light scouring of the downstream river channel.

[0068] The technical solution adopted by the present invention to solve the technical problem is:

[0069] 1. From upstream to downstream, a multi-stage energy dissipation high-head flood discharge and emptying tunnel consists of an inlet section, a pressure section, an accident lock chamber section, a steel lining section, an energy dissipation pool, a vortex shaft, an energy dissipation well, a water withdrawal tunnel section and an outlet section.

[0070] 2. The elevation of the inlet section is set lower than the dead water level of the reservoir.

[0071] 3. The accident lock chamber section is located between the pressure section and the steel lining section, and consists of the lock chamber shaft and the accident gate control room:

[0072] 1) From upstream to downstream, the lock chamber shaft is equipped with a maintenance gate and an emergency gate, and a vent is arranged on the downstream side of the emergency gate; the vent outlet is located at the top of the flow channel at the lower part of the lock chamber shaft, and the vent inlet is located at the top of the lock chamber shaft. The vent inlet elevation is higher than the normal water level of the reservoir;

[0073] 2) The emergency gate control room is located at the top of the gate chamber shaft, and the bottom elevation is higher than the normal water level of the reservoir;

[0074] 3) The emergency gate control room is connected to the lock chamber traffic tunnel and air supply tunnel, and the ground can be reached through the lock chamber traffic tunnel and air supply tunnel.

[0075] 4. The energy dissipation pool is located between the steel lining section and the swirl shaft, and consists of a valve chamber and an energy dissipation pool:

[0076] 1) A branch pipe is provided at the bottom of the valve chamber to divide a drainage main pipe into multiple drainage branch pipes; a submerged cone valve is provided at the end of each drainage branch pipe;

[0077] 2) The upper part of the valve chamber is connected to the energy dissipation pool traffic tunnel and air supply tunnel, and can reach the ground through the energy dissipation pool traffic tunnel and air supply tunnel;

[0078] 3) An overflow weir is set in the energy dissipation pool, which is connected to the lower energy dissipation well through a swirl shaft. The top elevation of the overflow weir is higher than the outlet elevation of the cone valve;

[0079] 4) A middle partition wall is arranged between the valve chamber and the energy dissipation pool, and the top elevation of the middle partition wall is higher than the top elevation of the overflow weir.

[0080] 5. The energy dissipation well is located between the vortex shaft and the water withdrawal tunnel section, and consists of an energy dissipation well and a connecting horizontal tunnel:

[0081] 1) The bottom elevation of the energy dissipation well is lower than the bottom elevation of the connecting flat tunnel;

[0082] 2) The connecting flat tunnel adopts a flat bottom or a small slope inclined toward the downstream, and a pressure slope toward the downstream is set at the top of the connecting flat tunnel. The downstream end of the connecting flat tunnel adopts a sudden expansion shape to connect with the drainage tunnel.

[0083] 6. The water withdrawal tunnel section is located between the energy dissipation well and the outlet section, and a multi-orifice plate energy dissipation structure is set in the water withdrawal tunnel section.

[0084] 7. The outlet section connects the drainage tunnel section and the downstream river channel, and is composed of stepped energy dissipators, concrete groves and block stone backfill sections.

Claims

1. An energy dissipation flood discharge and emptying cavern for high water head, comprising an inlet section (1), a pressure section (2), a control structure and an outlet section (3), wherein the elevation of the water inlet of the inlet section is lower than the elevation of the dead water level of the reservoir, and the inlet section (1), the pressure section (2), the control structure and a part of the outlet section (3) are all located in the rock mass, and characterized in that: The energy dissipation and flood discharge hole also includes a swirl energy dissipation connection system, the inlet end of the swirl energy dissipation connection system is connected to the control structure, and the outlet end of the swirl energy dissipation connection system is connected to the outlet section (3).

2. The energy dissipation flood discharge and hollowing hole for high water head according to claim 1 is characterized in that: The control structure comprises an inspection gate (4) and its mounting mechanism, an emergency gate (5) and its mounting mechanism, and a hoist (6). The mounting mechanism of the inspection gate (4) and the mounting mechanism of the emergency gate (5) are sequentially arranged between the pressure section (2) and the swirl energy dissipation connection system along the water delivery direction. The inspection gate (4) and the emergency gate (5) arranged in the corresponding mounting mechanism are opened or closed respectively by the corresponding hoist (6).

3. The energy dissipation flood discharge and hollowing hole for high water head according to claim 2 is characterized in that: Each installation mechanism comprises a gate chamber shaft (7) and a gate control room (8) arranged at the top of the gate chamber shaft. The hoist (6) is arranged in the gate control room (8). A steel lining section (9) is also arranged at the end of the bottom of the gate chamber shaft of the accident gate along the water conveyance direction. The end of the steel lining section (9) is connected to the inlet end of the swirl energy dissipation connection system.

4. The energy dissipation flood discharge and hollowing hole for high water head according to claim 3 is characterized in that: The gate control room (8) of the maintenance gate (4) and the gate control room (8) of the accident gate (5) are an integrated structure. The control structure also includes a traffic air supply hole (10) connected to the ground. One end of the traffic air supply hole (10) located in the rock mass is connected to the gate control room (8). An erosion vent (11) connected to the bottom end of the accident gate chamber shaft is also provided in the side wall on the downstream side of the accident gate chamber shaft. The upper end of the erosion vent (11) is connected to the gate control room (8).

5. The energy dissipation flood discharge and hollowing hole for high water head according to claim 1, 2, 3 or 4, characterized in that: The swirl energy dissipation connection system comprises an outlet energy dissipation structure, a swirl energy dissipation structure and a water-returning energy dissipation conveying structure. The outlet energy dissipation structure, the swirl energy dissipation structure and the water-returning energy dissipation conveying structure are sequentially connected along the water conveying direction. The end of the bottom of the vertical shaft of the emergency gate chamber is connected to the outlet energy dissipation structure through a steel lining section (9), and the end of the water-returning energy dissipation conveying structure is connected to the input end of the outlet section (3).

6. The energy dissipation flood discharge and hollowing hole for high water head according to claim 5 is characterized in that: The outlet energy dissipation structure comprises a valve chamber and an energy dissipation pool (12) connected in sequence, the input end of the valve chamber is connected to the output end of the steel lining section (9), and the output end of the energy dissipation pool (12) is connected to the swirl energy dissipation structure.

7. The energy dissipation flood discharge and hollowing hole for high water head according to claim 6 is characterized in that: The valve chamber comprises a valve chamber body (13), a drainage main pipe (14), a branch pipe (15), at least two drainage branch pipes (16), a plurality of submerged cone valves (17) whose number is equal to the number of drainage branch pipes (16), and a middle partition wall (18). The output ends of the drainage branch pipes (16) supported on the middle partition wall (18) are respectively connected to the drainage main pipe (14) through the branch pipe (15). A submerged cone valve (17) is respectively installed at the end of each drainage branch pipe (16). Each submerged cone valve (17) is respectively submerged in the energy dissipation pool (12). An overflow weir (19) is also arranged at the output end of the energy dissipation pool (12). The swirl energy dissipation structure is connected to the energy dissipation pool (12) through the overflow weir (19). A traffic air supply hole (10) connected to the ground is also arranged on the side wall of the valve chamber body (13).

8. The energy dissipation flood discharge and hollowing hole for high water head according to claim 7 is characterized in that: The vortex energy dissipation structure comprises an energy dissipation pool connecting section (20), a nest chamber (21), a vortex shaft (22), a connecting shaft (23) and an energy dissipation well. The input end of the energy dissipation pool connecting section (20) is connected to the energy dissipation pool (12) through an overflow weir (19), the output end of the energy dissipation pool connecting section (20) is connected to the top of the nest chamber (21), the connecting shaft (23) is connected to the nest chamber (21) from the bottom through the vortex shaft (22), the energy dissipation well is arranged vertically at the bottom of the connecting shaft (23), and the water withdrawal energy dissipation conveying structure is horizontally or inclinedly connected to the top of the energy dissipation well from the side.

9. The energy dissipation flood discharge and hollowing hole for high water head according to claim 8 is characterized in that: The water retreat and energy dissipation conveying structure comprises an energy dissipation orifice plate (24) and a water delivery pipe (25) arranged horizontally or obliquely. At least two groups of energy dissipation orifice plates (24) are arranged on the water delivery pipe (25) at intervals along the water delivery direction. The input end of the water delivery pipe (25) is connected to the energy dissipation well horizontally or obliquely from the side, and the output end of the water delivery pipe (25) is connected to one end of the outlet section (3) located in the rock mass.

10. The energy dissipation flood discharge and hollowing hole for high water head according to claim 9, characterized in that: The energy dissipation well comprises an energy dissipation well body (26) and a connecting flat tunnel (27). The connecting flat tunnel (27) is arranged horizontally or obliquely on the top of the energy dissipation well body (26) from the side. A pressure slope toward the downstream is arranged on the top of the connecting flat tunnel (27). The downstream end of the connecting flat tunnel (27) is connected to the input end of the water delivery pipe (25) through a sudden expansion body. A stepped energy dissipation subsection (28), a concrete tooth groove subsection (29) and a block stone backfill subsection (30) are sequentially arranged on the outlet section (3) outside the rock body.

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