Hydropower Engineering Bottom Hole Maintenance and Sealing Structure and Its Application Method

Abstract

This invention relates to a sealing structure and its application method for bottom hole maintenance in hydropower projects, falling within the technical field of hydraulic structure inspection and maintenance in water conservancy and hydropower engineering. The invention includes sealing gates, a crossbeam structure, and a pressure-limiting pipe. Two sealing gates are present: one upstream (upstream sealing gate) and the other downstream (downstream sealing gate), connected as a single unit by the connecting crossbeam structure. The pressure-limiting pipe is a steel pipe structure, with its two ends connected to the reservoir water in front of the upstream water-retaining gate and the water body between the downstream water-retaining gate and the working arc gate, respectively. This invention involves installing two sealing gates within the tunnel, connected as a single unit by three crossbeams. A traveling device moves the sealing structure, and a water seal component presses it tightly against the tunnel wall to achieve the sealing effect. The pressure-limiting pipe balances the upstream and downstream water pressure, ultimately achieving dry construction conditions between the two sealing gates. During construction, the sealing structure is stable, provides good water-stopping effect, and facilitates construction and maintenance within the tunnel.

Description

Technical Field

[0001] This invention relates to the field of hydraulic structure inspection and maintenance technology in water conservancy and hydropower projects, specifically providing a highly applicable and convenient sealing structure for the maintenance and sealing of bottom holes in hydropower projects, as well as its usage method. Background Technology

[0002] Along with the construction of the project, tunnels such as spillway tunnels, sand flushing tunnels, and venting tunnels have experienced varying degrees of erosion damage after undergoing high-flow-rate water discharge and sand flushing operations. To ensure the safety of these hydraulic structures, it is necessary to repair the damaged structures. If not handled properly, internal defects may continue to develop under continued water discharge and sand flushing operations, affecting the safety of the project. Therefore, it is essential to repair these defective hydraulic structures. To provide dry construction conditions for the repair work, it is crucial to study scientific and reasonable plugging schemes.

[0003] Document CN 117367696 A discloses a test device and method for testing the sealing capacity of airbags in large-section tunnels. The device includes an airbag. According to the document, airbag sealing methods are widely used in sealing small pipelines or tunnels, but there is limited experience to draw upon both domestically and internationally for sealing large-scale tunnels. In sealing very large underwater tunnels, the airbag needs to overcome enormous reservoir water pressure. Increased external pressure necessitates high internal pressure in the airbag, and the material of the airbag and its sealing capacity cannot be tested to ensure effective sealing. The problems with this method are: 1. This method relies on the expansion of the airbag after being filled with high-pressure gas, resulting in close contact between the outer wall of the airbag and the inner wall of the tunnel. Under the pressure of the reservoir water, static friction is generated between the outer wall of the airbag and the inner wall of the tunnel to resist the reservoir water pressure. 1. After long-term operation, the inner surface of the tunnel becomes smooth, and its condition is difficult to assess, making it difficult to determine the static friction between the outer wall of the airbag and the inner wall of the tunnel; 2. Different projects have different tunnel shapes, and the airbag device can only be installed in the circular section of the tunnel to be sealed. It overcomes water pressure through the static friction between the outer wall of the airbag and the inner wall of the tunnel, so the airbag structure needs to be of sufficient length. This solution is difficult to adapt to different tunnel shapes; 3. The airbag device is huge, and its manufacturing quality and precision are difficult to guarantee. If air leakage occurs during sealing, the tunnel will not be able to be sealed, resulting in a major safety accident.

[0004] In water conservancy and hydropower projects, the metal structure layout of tunnels such as flood discharge tunnels, sand flushing tunnels, and venting tunnels is mostly as follows: an emergency plane gate is arranged at the beginning of the pressurized section of the tunnel, and an arc-shaped working gate is arranged at the end of the pressurized section of the tunnel. Therefore, it is possible to consider using the arc-shaped gate to block water as an auxiliary measure of the sealing equipment, and to seal the damaged location of the tunnel for maintenance through the sealing equipment. Summary of the Invention

[0005] The present invention aims to solve the problems existing in the use of airbags for sealing large-section tunnels, and provides a highly applicable and convenient sealing structure for the maintenance of bottom holes in hydropower projects, as well as its usage method.

[0006] The hydropower project bottom hole maintenance sealing structure of the present invention is installed inside the tunnel, located on both sides of the maintenance section. Its characteristic is that the sealing structure includes sealing gates, a crossbeam structure, and a pressure-reducing pipe. There are two sealing gates: one located upstream (upstream sealing gate) and the other downstream (downstream sealing gate), connected as a whole by the connecting crossbeam structure. The pressure-reducing pipe is a steel pipe structure, with its two ends connected to the reservoir water in front of the upstream sealing gate and the water body between the downstream sealing gate and the working arc gate, respectively.

[0007] Two sets of water seal assemblies are respectively installed at the top and bottom of the sealing gate; the sealing gate is a box structure containing several cavities, including a sealing equipment cavity, a weighting cavity and a buoyancy cavity. The sealing equipment cavity is located at the top and bottom of the sealing gate, the buoyancy cavity is located at the upper part of the sealing gate, and the weighting cavity is located at the lower part of the sealing gate.

[0008] The crossbeam structure includes an upper crossbeam, a middle crossbeam, and a lower crossbeam. All three crossbeams are box-type structures. The upper and middle crossbeams contain several buoyancy chambers, while the lower crossbeam contains several buoyancy chambers and three travel equipment chambers. These three travel equipment chambers are equidistant, with buoyancy chambers between them. Each travel equipment chamber houses a travel device, including wheels, an underwater motor, a reducer, a brake, and a battery. The battery is placed inside the travel equipment chamber. The underwater motor is fixed to the bottom of the lower crossbeam and connected to the battery via wires. The underwater motor, reducer, and wheels are connected sequentially, with the underwater motor driving the wheels through the reducer. The brake is mounted on the wheels.

[0009] The pressure equalization pipe is also equipped with a valve assembly, which includes a maintenance valve and a working valve. The working valve is installed on the pressure equalization pipe, and the maintenance valve is located on the pressure equalization pipe upstream of the working valve. The working valve is used to open or close the passage inside the pressure equalization pipe, and the working valve can be maintained after the maintenance valve is closed.

[0010] The water seal assembly includes a high-pressure gas tank, push rods, guide grooves, a water seal base, and a water seal strip. The high-pressure gas tank is placed in the middle of the sealing equipment cavity. Two sets of guide grooves are respectively set on both sides of the sealing equipment cavity. A water seal base is installed in each set of guide grooves and slides along the guide groove. Two push rods are respectively fixed on both sides of the high-pressure gas tank. The top of the push rods is connected to the water seal base, and the push rods are connected to the high-pressure gas tank by air pipes. The water seal strip wraps around the outer end of the water seal base from the inside to the outside.

[0011] The water seal base is also provided with a pressure block and a fastener. The pressure block and the fastener are both located on the inner wall of the outer end of the water seal base. The water seal strip is fastened to the water seal base by the pressure block and the fastener.

[0012] Instructions for using the maintenance and sealing structure for bottom holes in hydropower projects:

[0013] (1) When the sealing structure moves inside the tunnel, the push rod retracts, the water seal assembly retracts into the sealing gate, the walking device is activated, the underwater motor drives the walking wheels to rotate through the reducer, and drives the entire sealing structure to move inside the tunnel through the lower crossbeam.

[0014] (2) During tunnel maintenance:

[0015] (a) First, close the working arc gate;

[0016] (b) The sealing structure is moved to the location inside the tunnel where maintenance is required;

[0017] (c) Activate the water seal assembly. The push rod extends to push the water seal base. Under the guidance of the guide groove, the water seal base extends and fits against the inner wall of the tunnel.

[0018] (d) The high-pressure gas tank is opened and air is injected into the back pressure chamber of the water seal base to press the water seal strip tightly against the inner wall of the tunnel, thus sealing off the water. This improves safety through at least two water seal components.

[0019] (e) Open the working valve on the pressure equalization pipe to balance the reservoir water pressure borne by the upstream blocking gate and the pressure in front of the working arc gate borne by the downstream blocking gate;

[0020] (f) Draining the water between the upstream and downstream blocking gates will create dry conditions for construction.

[0021] The hydropower engineering bottom hole maintenance and sealing structure of the present invention is scientifically designed and easy to use. Two sealing gates are set in the tunnel and connected as a whole by three crossbeams. The sealing structure is moved by a walking device, and the sealing effect is achieved by pressing the water seal component tightly against the inner wall of the tunnel. The pressure equalization pipe is used to balance the water pressure between the upstream and downstream, and finally achieves dry construction conditions between the two sealing gates. During the construction process, the sealing structure is stable, has a good water-stopping effect, and is convenient for construction and maintenance in the tunnel. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention.

[0023] Figure 2 This is a schematic diagram of the water seal assembly.

[0024] Figure 3 This is a schematic diagram of the walking device.

[0025] Figure 4This is a schematic diagram of the blocked state.

[0026] Among them, the tunnel is 1, the sealing gate is 2, the pressure equalization pipe is 3, the sealing equipment cavity is 4, the weighting cavity is 5, the buoyancy cavity is 6, the maintenance valve is 7, the working valve is 8, the high-pressure gas tank is 9, the push rod is 10, the guide groove is 11, the water seal base is 12, the water seal strip is 13, the pressure block is 14, the fastener is 15, the upper crossbeam is 16, the middle crossbeam is 17, the lower crossbeam is 18, the traveling equipment cavity is 19, the traveling wheel is 20, the underwater motor is 21, the reducer is 22, and the battery is 23. Detailed Implementation

[0027] Example 1: A bottom hole maintenance sealing structure for hydropower projects, installed inside the tunnel on both sides of the maintenance section. The sealing structure includes sealing gates, a crossbeam structure, and a pressure-lifting pipe. There are two sealing gates: one located upstream (upstream sealing gate) and the other downstream (downstream sealing gate). The two gates are connected as a single unit by the connecting crossbeam structure. The pressure-lifting pipe is a steel pipe structure, with its two ends connected to the reservoir water in front of the upstream sealing gate and the water body between the downstream sealing gate and the working arc gate, respectively. Wherein:

[0028] Two sets of water seal components are installed at the top and bottom of the sealing gate respectively; the sealing gate is a box structure containing several cavities, including a sealing equipment cavity, a weighting cavity and a buoyancy cavity. The sealing equipment cavity is located at the top and bottom of the sealing gate respectively, the buoyancy cavity is located at the upper part of the sealing gate, and the weighting cavity is located at the lower part of the sealing gate.

[0029] The crossbeam structure includes an upper crossbeam, a middle crossbeam, and a lower crossbeam. All three crossbeams are box-type structures. The upper and middle crossbeams contain several buoyancy chambers, while the lower crossbeam contains several buoyancy chambers and three travel equipment chambers. These three travel equipment chambers are equidistant, with buoyancy chambers between them. Each travel equipment chamber houses a travel device, including wheels, an underwater motor, a reducer, a brake, and a battery. The battery is placed inside the travel equipment chamber. The underwater motor is fixed to the bottom of the lower crossbeam and connected to the battery via wires. The underwater motor, reducer, and wheels are connected sequentially, with the underwater motor driving the wheels through the reducer. The brake is mounted on the wheels.

[0030] The pressure equalization pipe is also equipped with a valve assembly, which includes a maintenance valve and a working valve. The working valve is installed on the pressure equalization pipe, and the maintenance valve is located on the pressure equalization pipe upstream of the working valve. The working valve is used to open or close the passage inside the pressure equalization pipe, and the working valve can be maintained after the maintenance valve is closed.

[0031] The water seal assembly includes a high-pressure gas tank with a pressure of not less than 2 MPa, push rods, guide grooves, a water seal base, and a water seal strip. The high-pressure gas tank is placed in the middle of the sealing equipment cavity. Two sets of guide grooves are respectively set on both sides of the sealing equipment cavity. A water seal base is installed in each set of guide grooves and slides along the guide groove. Two push rods are respectively fixed on both sides of the high-pressure gas tank. The top of the push rod is connected to the water seal base, and the push rod is connected to the high-pressure gas tank by an air pipe. The water seal strip wraps around the outer end of the water seal base from the inside to the outside.

[0032] The water seal base is also equipped with pressure blocks and fasteners. The pressure blocks and fasteners are both located on the inner wall of the outer end of the water seal base. The water seal strip is fastened to the water seal base by the pressure blocks and fasteners.

[0033] Instructions for using the maintenance and sealing structure for bottom holes in hydropower projects:

[0034] (1) When the sealing structure moves inside the tunnel, the push rod retracts, the water seal assembly retracts into the sealing gate, the walking device is activated, the underwater motor drives the walking wheels to rotate through the reducer, and drives the entire sealing structure to move inside the tunnel through the lower crossbeam.

[0035] (2) During tunnel maintenance:

[0036] (a) First, close the working arc gate;

[0037] (b) The sealing structure is moved to the location inside the tunnel where maintenance is required;

[0038] (c) Activate the water seal assembly. The push rod extends to push the water seal base. Under the guidance of the guide groove, the water seal base extends and fits against the inner wall of the tunnel.

[0039] (d) The high-pressure gas tank is opened and air is injected into the back pressure chamber of the water seal base to press the water seal strip tightly against the inner wall of the tunnel, thus sealing off the water. This improves safety through at least two water seal components.

[0040] (e) Open the working valve on the pressure equalization pipe to balance the reservoir water pressure borne by the upstream blocking gate and the pressure in front of the working arc gate borne by the downstream blocking gate;

[0041] (f) Draining the water between the upstream and downstream blocking gates will create dry conditions for construction.

Claims

1. A maintenance plugging structure of a water and electricity engineering bottom hole, which is arranged in a tunnel and located at both sides of a maintenance section, characterized in that: The blocking structure comprises blocking gates, a beam structure and a flat compression pipe. The blocking gates are two, one of which is arranged at an upstream position as an upstream blocking gate, and the other is arranged at a downstream position as a downstream blocking gate. The two blocking gates are connected by the connecting beam structure to form a whole. The flat compression pipe is a steel pipe structure. The two ends of the flat compression pipe are respectively connected with reservoir water in front of the upstream blocking gate and water between the downstream blocking gate and the working arc gate. Wherein, The top and bottom of the blocking gate are respectively provided with two sets of water seal assemblies. The blocking gate is a box structure, and contains several cavities in the inside. The cavities include a blocking device cavity, a weighting cavity and a buoyancy cavity. The blocking device cavities are respectively arranged at the top and bottom of the blocking gate. The buoyancy cavity is arranged at the upper part of the blocking gate. The weighting cavity is arranged at the lower part of the blocking gate. The water seal assembly comprises a high-pressure gas tank, a push rod, a guide groove, a water seal base and a water seal strip. The high-pressure gas tank is placed in the middle of the blocking device cavity. Two groups of guide grooves are respectively arranged on the two sides of the blocking device cavity. One water seal base is installed in each guide groove. The water seal base slides along the guide groove. Two push rods are respectively fixed on the two sides of the high-pressure gas tank. The top of the push rod is connected with the water seal base. The push rod and the high-pressure gas tank are connected by an air pipe. The water seal strip is wrapped outside the water seal base from inside to outside. The beam structure comprises an upper beam, a middle beam and a lower beam. The upper beam, the middle beam and the lower beam are all box structures. The upper beam and the middle beam are internally provided with several buoyancy cavities. The lower beam is internally provided with several buoyancy cavities and three walking device cavities. The three walking device cavities are equidistantly arranged. The walking device cavities are provided with buoyancy cavities therebetween. A walking device is arranged in the walking device cavity. The walking device comprises a walking wheel, an underwater motor, a speed reducer, a brake and a storage battery. The storage battery is placed in the walking device cavity. The underwater motor is fixed at the bottom of the lower beam. The underwater motor is connected with the storage battery by a wire. The underwater motor, the speed reducer and the walking wheel are sequentially connected. The underwater motor drives the walking wheel to rotate through the speed reducer. The brake is installed on the walking wheel.

2. The hydroelectric engineering bottom hole maintenance plugging structure according to claim 1, characterized in that: The flat compression pipe is further provided with a valve assembly. The valve assembly comprises a maintenance valve and a working valve. The working valve is installed on the flat compression pipe. The maintenance valve is arranged on the flat compression pipe in front of the working valve.

3. The hydroelectric engineering bottom hole maintenance plugging structure according to claim 1, characterized in that: The water seal base is further provided with a pressing block and a fastener. The pressing block and the fastener are both arranged on the inner wall of the outer end of the water seal base. The water seal strip is fastened on the water seal base by the pressing block and the fastener.

4. The use method of the water and electricity engineering bottom hole maintenance blocking structure according to any one of claims 1 to 3, characterized in that: The use method comprises the following steps: (1) When the blocking structure walks in the tunnel, the push rod is retracted, the water seal assembly is retracted in the blocking gate, the walking device is turned on, the underwater motor drives the walking wheel to rotate through the speed reducer, and the whole blocking structure walks in the tunnel through the lower beam; (2) When the tunnel is maintained: (a) first close the working arc gate; (b) the blocking structure walks to the position in the tunnel that needs to be maintained; (c) start the water seal assembly, the push rod extends to push the water seal base, and the water seal base extends and is attached to the inner wall of the tunnel under the guidance of the guide groove; (d) The high-pressure tank is opened to inflate the back pressure chamber of the water seal base, and the water seal strip is pressed tightly against the inner wall of the tunnel to tightly stop water, and the safety is improved through at least two water seal assemblies; (e) The working valve on the flat pressure pipe is opened to balance the pressure of the reservoir water borne by the upstream blocking gate and the pressure before the working arc gate borne by the downstream blocking gate; (f) The water between the upstream blocking gate and the downstream blocking gate is drained, and dry construction conditions are formed.

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