Hole plug type flood discharge tunnel

Abstract

The utility model discloses a hole plug type flood discharge tunnel which comprises an inlet control section, an upper flat section, a vertical shaft section and a lower flat section which are sequentially arranged in the direction from upstream to downstream, an outlet pressing slope is arranged at an outlet of the lower flat section, hole plugs are arranged in the vertical shaft section and the lower flat section, a gate is arranged in front of the inlet control section, and the gate is connected with the vertical shaft section and the lower flat section. The gate comprises a bulkhead gate and a service gate which are sequentially arranged in the direction from upstream to downstream. An outlet gate is arranged at an outlet of the lower flat section, and the tail end of the lower flat section comprises an out-of-tunnel energy dissipation facility used for being connected with the outlet gate. According to the utility model, air in the flow channel can be exhausted completely, and the phenomenon of gas explosion at the initial stage of operation is avoided; the outlet gate can ensure that water flow in the tunnel is in a pressure flow state, is more suitable for the situation that the downstream water level is low, is convenient to operate and dispatch, and effectively reduces the risk when the tunnel plug flood discharge tunnel is opened for flood discharge.

Description

Technical Field

[0001] The utility model relates to a plug-type flood discharge tunnel in water conservancy and hydropower engineering. Background Art

[0002] The plug-type flood spillway is often equipped with multi-stage plug energy dissipation devices inside. By reducing the diameter of the plug section, the water will generate violent turbulence when flowing through these sudden expansion and contraction sections, thereby dissipating the water flow energy, achieving the purpose of reducing the outlet flow velocity of the lower flat section and protecting the downstream riverbed from scouring. Most of the plug-type flood spillways are rebuilt from the diversion tunnels built in the early stage of the project. Because the diversion tunnel has a low elevation, simple structure, and convenient reconstruction and construction, it can greatly save project investment.

[0003] The structure of the plug-type flood discharge tunnel includes an inlet control section, an upper flat section, a shaft section and a lower flat section. Plugs are set in both the shaft section and the lower flat section, and a flow hole is installed in the middle of the plug. In order to reduce the size of the working gate, the working gate is usually set at the entrance of the tunnel. In order to ensure that there is enough positive pressure inside the plug to prevent water cavitation and cavitation damage to the tunnel structure, a pressure slope structure is generally set at the end of the plug energy dissipation section. The function of the pressure slope structure is to maintain the positive pressure inside the plug by gradually reducing the speed and energy of the water flow, and to reduce the impact of the water flow on the plug and tunnel structure.

[0004] However, the existing plug-type spillway still has the following disadvantages in terms of its size and layout: 1. The plug-type spillway generally sets the working gate at the inlet, and the shaft section is in a waterless state before operation. If the air in the tunnel is not discharged smoothly at the initial stage of the gate opening, a transitional flow state of alternating open and full flow will appear, accompanied by the risk of cavitation erosion. 2. In order to ensure a pressurized flow state in the tunnel, the outlet at the end of the energy dissipation section in the tunnel usually adopts a pressure slope structure. This layout type will limit the discharge of air in the tunnel. Especially under the action of high-flow and high-velocity water flow, the gas will be quickly compressed at the entrance of the tunnel, which can easily cause gas explosions. In extreme cases, this may cause serious damage to the lining structure. 3. The plug-type spillway is generally suitable for high water level conditions downstream, but for the situation where the downstream tailwater is lower than the pressure slope outlet elevation at the end of the lower flat section, it is difficult to form a pressurized flow state in the tunnel, and the plug-type spillway will not be applicable. The plug-type spillway tunnels in the prior art are often provided with exhaust passages, but the exhaust passages are generally narrow, and exhaust is often not smooth. At the same time, the exhaust passages are connected to the flow passages, which will also affect the structural strength of the entire spillway tunnel. Utility Model Content

[0005] The utility model aims to provide a plug-type flood discharge tunnel to solve the technical problem that the air in the tunnel is difficult to discharge smoothly at the initial stage of opening the flood discharge tunnel gate.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] A plug-type flood discharge tunnel comprises an inlet control section, an upper flat section, a shaft section and a lower flat section which are sequentially arranged from upstream to downstream, an outlet of the lower flat section is provided with an outlet pressure slope, and plugs are provided in the shaft section and the lower flat section, and is characterized in that: an inspection gate and a working gate are sequentially arranged on the upstream side of the inlet control section from upstream to downstream; an energy dissipation facility outside the tunnel connected with the lower flat section is arranged downstream of the lower flat section, and an outlet gate for blocking the outlet of the lower flat section is arranged inside the energy dissipation facility outside the tunnel.

[0008] Therefore, in the initial stage of operation, when there is no water in the flood discharge tunnel, the inspection gate and the working gate can be opened first, the outlet gate can be closed, and then water can be slowly poured into the flood discharge tunnel. After the water fills the entire flow channel, the outlet gate can be opened and the flood discharge can be started. Due to the slow water filling speed, the water will squeeze the air in the flow channel, and the original air in the flow channel will slowly be discharged from the opened inspection gate and the working gate until the water fills the entire flow channel. Since the outlet gate is set, it can ensure the stability of the structure while avoiding gas explosion in the initial stage of operation, which helps to completely discharge the air in the flow channel.

[0009] According to the embodiments of the present invention, the present invention can be further optimized. The following is the technical solution formed after optimization:

[0010] In order to facilitate the connection between the lower flat section and the outlet gate and ensure structural stability, in a specific embodiment, the lower flat section includes a top arch, and the outlet pressure slope is arranged at the top arch downstream of the lower flat section. The cross-sectional shape of the lower flat section is a city gate hole shape, and the cross-sectional shape of the energy dissipation facility outside the hole gradually changes from a city gate hole shape to a rectangle along the upstream to downstream direction.

[0011] In a specific embodiment, the outlet pressure slope extends downward from the top of the lower flat section to the outlet at the tail end of the lower flat section in the upstream to downstream direction.

[0012] In a specific embodiment, the hole plug is provided with one or more stages.

[0013] In a specific embodiment, two levels of first hole plugs are arranged in the vertical shaft section along the height direction of the vertical shaft section; and second hole plugs and two levels of third hole plugs are arranged in sequence from upstream to downstream in the lower flat section along the length direction of the lower flat section.

[0014] Compared with the prior art, the beneficial effects of the utility model are as follows: the plug-type flood spillway of the utility model helps to completely discharge the air in the flow channel, avoiding gas explosions in the initial stage of operation; the outlet gate can ensure that the water flow in the tunnel is in a pressurized flow state, which is more suitable for situations where the downstream water level is low, facilitates operation and scheduling, and effectively reduces the risks faced when the plug-type flood spillway is opened to discharge flood water. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the utility model;

[0016] Figure 2 It is a structural schematic diagram of the energy dissipation facility outside the tunnel at the tail end of the lower flat section of the utility model.

[0017] In the figure

[0018] 1-inlet control section, 2-upper horizontal section, 3-shaft section, 4-lower horizontal section, 5-hole plug, 51-first hole plug, 52-second hole plug, 53-third hole plug, 6-outlet pressure slope, 7-maintenance gate, 8-working gate, 9-outlet gate, 10-energy dissipation facilities outside the tunnel. DETAILED DESCRIPTION

[0019] The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict. For the convenience of description, if the words "upper", "lower", "left" and "right" appear in the following text, they only indicate that the upper, lower, left and right directions are consistent with the drawings themselves, and do not limit the structure.

[0020] like Figure 1 As shown, the plug-type flood discharge tunnel of this embodiment includes an inlet control section 1, an upper flat section 2, a shaft section 3 and a lower flat section 4 which are arranged in sequence from upstream to downstream. The outlet of the lower flat section 4 is provided with an outlet pressure slope 6, which is arranged on the upper side of the downstream of the lower flat section 4, and the outlet pressure slope 6 extends downward from the top of the lower flat section 4 to the outlet at the tail end of the lower flat section 4 along the upstream to downstream direction; plugs 5 are arranged in both the shaft section 3 and the lower flat section 4, and the plugs 5 are arranged in one or more stages, and two stages of first plugs 51 are arranged in the shaft section 3 along the height direction of the shaft section 3; and second plugs 52 and two stages of third plugs 53 are arranged in sequence from upstream to downstream in the lower flat section 4 along the length direction of the lower flat section 4.

[0021] A gate is provided in front of the inlet control section 1, and the gate includes a maintenance gate 7 and a working gate 8 arranged in sequence from upstream to downstream; an energy dissipation facility 10 outside the tunnel connected to the lower flat section 4 is provided downstream of the lower flat section 4, and an outlet gate 9 for blocking the outlet of the lower flat section 4 is provided inside the energy dissipation facility 10 outside the tunnel. The cross-sectional shape of the lower flat section 4 is a city gate tunnel shape, and the cross-sectional shape of the energy dissipation facility 10 outside the tunnel is a rectangle, so as to facilitate the installation of the outlet gate 9.

[0022] At the initial stage of operation, when there is no water in the flood discharge tunnel, the inspection gate and the first working gate can be opened first, the outlet gate 9 can be closed, and then water can be slowly poured into the flood discharge tunnel. After the water flow fills the entire flow channel, the outlet gate can be opened again, and then the flood discharge can be started. Since the outlet gate is set, the structural stability can be ensured while avoiding the occurrence of gas explosion in the initial stage of operation, which helps to discharge all the air in the flow channel, solving the technical problem that if the air in the tunnel is not discharged smoothly at the initial stage of gate opening in the prior art, a transitional flow state of alternating between bright and full flow will occur, and there is also a risk of cavitation and erosion. By closing the outlet gate 9 and slowly filling the entire flow channel, due to the slow water filling speed, the water will squeeze the air in the flow channel, and the original air in the flow channel will slowly be discharged from the opened inspection gate and working gate until the water fills the entire flow channel, which can effectively solve the problem of inconvenient discharge of air in the flood discharge tunnel. At the same time, the outlet gate can ensure that the water flow in the tunnel is in a pressurized flow state, which is more suitable for situations where the downstream water level is low, and is convenient for operation scheduling.

[0023] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art fall within the scope defined by the claims attached to this application.

Claims

1. A plug-type flood discharge tunnel, comprising an inlet control section (1), an upper flat section (2), a shaft section (3) and a lower flat section (4) arranged in sequence from upstream to downstream, the outlet of the lower flat section (4) being provided with an outlet pressure slope (6), and plugs (5) being provided in both the shaft section (3) and the lower flat section (4), characterized in that: An inspection gate (7) and a working gate (8) are sequentially arranged on the upstream side of the inlet control section (1) in the upstream to downstream direction; an energy dissipation facility (10) outside the tunnel connected to the lower flat section (4) is arranged downstream of the lower flat section (4); and an outlet gate (9) for blocking the outlet of the lower flat section (4) is arranged inside the energy dissipation facility (10) outside the tunnel.

2. The plug-type flood discharge tunnel according to claim 1 is characterized in that: The lower flat section (4) comprises a top arch, and the outlet pressure slope (6) is arranged at the top arch downstream of the lower flat section (4).

3. The plug-type flood discharge tunnel according to claim 2 is characterized in that: The outlet pressure slope (6) extends downward from the top of the lower flat section (4) to the outlet at the tail end of the lower flat section (4) in the upstream to downstream direction.

4. The plug-type flood discharge tunnel according to claim 1 is characterized in that: The cross-sectional shape of the energy dissipation facility outside the cave (10) is rectangular.

5. The plug-type flood discharge tunnel according to any one of claims 1 to 4, characterized in that: The hole plug (5) is provided with one or more stages.

6. The plug-type flood discharge tunnel according to claim 5 is characterized in that: Two levels of first hole plugs (51) are arranged in the vertical shaft section (3) along the height direction of the vertical shaft section (3); and second hole plugs (52) and two levels of third hole plugs (53) are arranged in sequence from upstream to downstream in the lower flat section (4) along the length direction of the lower flat section (4).

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