Water cushion pond maintenance drainage and refilling system, drainage method and refilling method

Abstract

The present invention relates to a water cushion pond maintenance drainage and water refilling system, drainage method and water refilling method. The purpose of the present invention is to provide a safe, reliable and practical water cushion pond maintenance drainage and water refilling system, drainage method and water refilling method. The technical scheme of the present invention is: the system is arranged in Erdao Dam, and has: a gravity filling and drainage pipe connecting the water cushion pond upstream of Erdao Dam and the downstream river; a flow meter installed on the gravity filling and drainage pipe; a water collection tank arranged in the area connected to the Erdao Dam at the bottom of the water cushion pond; a maintenance drainage pipeline including a maintenance water intake pipe, a maintenance drainage main pipe I, a maintenance drainage branch pipe and a maintenance drainage main pipe II; a backwash pipeline including a maintenance water intake pipe, a maintenance drainage main pipe I and a maintenance drainage main pipe II; a pressure transmitter installed on the maintenance drainage main pipe I for monitoring the water level of the water collection tank in the water cushion pond; a control monitoring system connected to the flow meter and the pressure transmitter circuit. The present invention is applicable to the field of water conservancy and hydropower engineering.

Description

Technical Field

[0001] The invention relates to a water cushion pond maintenance drainage and water refilling system, a drainage method and a water refilling method, which are applicable to the field of water conservancy and hydropower engineering. Background Art

[0002] The cushion pond is an energy dissipation and anti-scouring protection project behind the arch dam. It prevents erosion damage to the dam foundation after the arch dam is discharged, and protects the safety and stability of the dam. Usually, when the arch dam is discharging flood water or the bank slope collapses during heavy rain, the cushion pond may be eroded. In order to ensure the safety of the dam, it is generally necessary to regularly pump out the water from the cushion pond for inspection and maintenance.

[0003] (1) At present, the cushion ponds of large hydropower stations such as Ertan, Laxiwa and Xiaowan that have been built in my country mostly use temporary pumping and drainage systems to pump out and empty the cushion ponds for maintenance.

[0004] The temporary pumping and drainage method has the following main shortcomings: 1. The system construction workload is large, and the drainage system and assembly procedures are cumbersome; 2. The system basically requires manual intervention throughout the entire process, and automatic control and monitoring cannot be achieved, making operation and maintenance inconvenient; 3. The pumping system equipment is all arranged outdoors, the drainage system has a high failure rate, low work efficiency, and a long drainage time; 4. Temporary power supplies and electromechanical equipment are exposed to the outside, which may pose a safety hazard to the staff.

[0005] (2) The Chinese patent "Water supply and drainage system for water cushion pond" with patent number 201020554462.5 provides a solution to set up a fixed pumping and drainage pump house in Erdao Dam for water cushion pond maintenance. Its advantages are: compared with previous solutions, it can realize automatic control operation of filling and draining water during water cushion pond maintenance.

[0006] However, this solution also has many disadvantages, mainly as follows: 1. The suction pipes installed before and after the water pump are lower than the bottom of the cushion pond, and the drainage pipes are lower than or close to the bottom of the riverbed. Since the system is only needed during the maintenance of the cushion pond and is not normally operated, the suction and drainage pipelines will naturally be silted up due to long periods of static state, resulting in blockage of the system and difficulty in silting the pipelines. Therefore, the drainage outlets and pipelines should be located in reasonable positions, and a certain backwashing function should also be considered; 2. The water pump system is only equipped with a control valve, and its function is not clear. In fact, after the water pressure before and after the cushion pond is balanced, the water pump needs to be pressurized to meet the normal operation of the water pump. Pump control valves and pressure-generating valves need to be added to meet the system operation needs; 3. The cushion pond maintenance drainage system is composed of multiple pump groups, which operate according to the comprehensive consideration of the water level in the cushion pond, and the small amount of water at the bottom of the cushion pond is not taken into account Collection and drainage during water accumulation; 4. The slopes on both sides of the large water cushion pond are relatively high. The second dam behind the water cushion pond must consider the influence of the valley deformation. The valley deformation will have a great impact on the pump room structure and the pumping and drainage pipelines. This patent does not consider this influence; 5. At the drainage pipe outlet, there are both rolling stones generated by the upstream flood discharge and debris such as woven bags that have not been cleaned up upstream, which poses a great safety hazard to the safe operation of water pumps, valves and drainage pipelines. The response plans for these factors are not reflected in this patent, and filtering equipment needs to be installed. 6. The water level range of the actual application of the filling and drainage pipeline system is not considered, and the noise generated under high-speed water flow is also not considered; 7. The sealing and maintenance of the drainage outlet of the downstream river channel must also consider corresponding measures in the water body; Therefore, according to the scheme of the present invention as an engineering application, a series of problems still need to be solved, so its practical value is not very high.

[0007] (3) The Chinese patent "Water cushion pond filling and drainage system capable of generating electricity" with patent publication number CN103556611B provides a pumped storage power plant building set up in the drainage corridor of Erdao Dam. By setting up a reversible turbine generator set, the water energy drop of the water cushion pond is automatically filled and drained, and the seepage water of the mountains on both sides is collected for power generation. While meeting the needs of water cushion pond maintenance and drainage, the energy consumption of the auxiliary system of the power station is reduced; the maintenance equipment can be used for power generation for a long time, which also improves the utilization rate of the equipment and reduces the failure rate of the equipment; this system greatly reduces the power consumed during filling and drainage and the operation and maintenance costs of the auxiliary system of the power station during operation, and the technical solution is more reliable, energy-saving and environmentally friendly.

[0008] However, the shortcomings of the Chinese patent "Water cushion pond water supply and drainage system" with patent number 201020554462.5 are not taken into consideration, thus limiting the actual application of the water cushion pond water supply and drainage system capable of generating electricity in water cushion pond maintenance and drainage facilities. Summary of the invention

[0009] The technical problem to be solved by the present invention is: in view of the above-mentioned problems, a safe, reliable and practical water cushion pond maintenance drainage and refilling system, drainage method and refilling method are provided.

[0010] The technical solution adopted by the present invention is: a water cushion pond maintenance drainage and recharging water system, which is arranged in the second dam and is characterized by having:

[0011] The gravity-flowing filling and drainage pipe connects the upstream cushion pond of Erdao Dam and the downstream river channel, and is equipped with a filling and drainage valve group;

[0012] A flow meter, installed on the gravity filling and drainage pipe, for obtaining flow changes in the gravity filling and drainage pipe;

[0013] The water collection tank is set at the bottom of the water cushion pond and the area connected to the second dam. A double-layer trash rack is installed at the water inlet of the water collection tank;

[0014] The maintenance drainage pipeline includes a maintenance water intake pipe, a maintenance drainage main pipe I, a maintenance drainage branch pipe and a maintenance drainage main pipe II, one end of the maintenance water intake pipe is connected to the water collection tank, and the other end of the maintenance water intake pipe is connected to the maintenance drainage main pipe I. The maintenance drainage main pipe I and the maintenance drainage main pipe II are connected through a number of maintenance drainage branch pipes, and the outlet of the maintenance drainage main pipe II is connected to the downstream river; wherein the maintenance water intake pipe is equipped with a maintenance water intake isolation valve, and the maintenance drainage branch pipe is equipped with a maintenance drainage pump;

[0015] The backwash pipeline includes the maintenance water intake pipe, the maintenance drainage main pipe I and the maintenance drainage main pipe II, the maintenance drainage main pipe I is connected with the maintenance drainage main pipe II through a backwash pipe, and the backwash pipe is equipped with a backwash valve group;

[0016] A pressure transmitter, installed in the said main inspection drainage pipe I, is used to monitor the water level of the water collection tank in the water cushion pond;

[0017] A control monitoring system connected to the flow meter and the pressure transmitter circuit;

[0018] The maintenance water intake pipe is divided into maintenance water intake pipe I and maintenance water intake pipe II, wherein the water intakes of maintenance water intake pipes I and II are respectively located at different high and low elevations in the water collection tank.

[0019] The outlet of the maintenance drainage main pipe II is connected to the gravity filling and drainage pipe via a tee, and the filling and drainage valve group includes an upstream filling and drainage valve group located upstream of the tee and a downstream filling and drainage valve group located downstream of the tee.

[0020] The elevation of the portion of the gravity-filled drainage pipe that is connected to the main maintenance drainage pipe II is higher than the elevation of the ports at both ends thereof.

[0021] A trash rack is provided at the water intake of the maintenance water intake pipe.

[0022] The maintenance drainage pumps on some of the maintenance drainage branch pipes adopt small maintenance drainage pumps, and the maintenance drainage pumps on the other maintenance drainage branch pipes adopt large maintenance drainage pumps.

[0023] The maintenance drainage main pipe II is divided into maintenance drainage main pipe II-I and maintenance drainage main pipe II-II. The small maintenance drainage pump and some large maintenance drainage pumps are connected to the maintenance drainage main pipe II-I, and the remaining large maintenance drainage pumps are connected to the maintenance drainage main pipe II-II.

[0024] The gravity filling and drainage pipe is divided into a gravity filling and drainage pipe I connected to the maintenance drainage main pipe II-I and a gravity filling and drainage pipe II connected to the maintenance drainage main pipe II-II.

[0025] The end of the gravity-filled drainage pipe connected to the downstream river channel is provided with a flange capable of installing a blind plate.

[0026] A drainage method for the water cushion pond maintenance drainage and water refilling system, characterized in that:

[0027] Open the filling and drainage valve group on the gravity filling and drainage pipe to discharge all the water in the cushion pond that is higher than the water level of the downstream river into the downstream river;

[0028] According to the flow signal change of the flow meter on the gravity discharge pipe, the water level in the cushion pond and the water level in the downstream river channel can be judged;

[0029] When the water level of the cushion pond is basically equal to the water level of the downstream river, shut off the filling and drainage valve group, open the maintenance water intake isolation valve on the maintenance water intake pipe Ⅰ, and introduce the water in the cushion pond to the maintenance drainage pump through the maintenance water intake pipe Ⅰ, the maintenance drainage main pipe Ⅰ, and the maintenance drainage branch pipe;

[0030] Start several maintenance drainage pumps to pump water from the cushion pond until the water level reaches the vicinity of the water intake of maintenance water intake pipe Ⅰ, stop the maintenance drainage pumps from pumping water, and close the maintenance water intake isolation valve on maintenance water intake pipe Ⅰ;

[0031] Open the backwash valve group on the backwash pipe, open the maintenance water intake isolation valve on the maintenance water intake pipe II, and use the water pressure of the downstream tail water that is higher than the water level in the upstream water cushion pond to flush the trash rack and maintenance water intake pipe II;

[0032] After flushing is completed, close the backwash valve group and use several maintenance drainage pumps to drain the remaining water in the water cushion pond;

[0033] The pressure transmitter signal installed on the maintenance drainage main pipe Ⅰ is used to monitor the water level in the water collection tank in the water cushion pond, and control several maintenance drainage pumps to discharge the accumulated water in the water collection tank in the water cushion pond.

[0034] A water refilling method for the water cushion pond maintenance drainage and refilling water system, characterized in that:

[0035] Open the filling and drainage valve group on the gravity filling and drainage pipe, and use the water level of the downstream river channel to be higher than the bottom plate elevation of the cushion pond to gravity-flow backfill the water downstream of Erdao Dam through the gravity filling and drainage pipe to the cushion pond;

[0036] The water flow rate in the gravity filling and drainage pipeline is monitored by the data transmitted by the flow meter installed on the gravity filling and drainage pipeline, thereby judging whether the water filling is completed;

[0037] When the water filling is completed, close the filling and drainage valve group on the gravity filling and drainage pipeline.

[0038] The beneficial effects of the present invention are as follows: the present invention solves the impact of rolling stones in the water cushion pond maintenance drainage system on the water intake by setting water intakes at different elevations, and can also solve the impact of floating objects and silt deposition on silt accumulation and safe operation of equipment in the water cushion pond maintenance drainage system.

[0039] The present invention solves the problem of large-scale water pumping in the early stage and the automatic drainage system for leakage and accumulated water in the pond for later maintenance by arranging pump groups of different sizes and types; and arranges a reasonable backwash pipeline to prepare a backup measure for solving the clogging problem of water intake and drainage.

[0040] In the present invention, the filling and drainage pipeline for the water cushion pond maintenance is set up in combination with the water intake pipe, the drainage main pipe I, the drainage branch pipe, the drainage main pipe II and the gravity filling and drainage pipe, and is set at a reasonable water level, which can not only meet the gravity filling and drainage needs, but also avoid clogging. In addition, the powerful drainage capacity of the water pump group can be used to provide safety protection for the gravity filling and drainage pipeline to prevent clogging and debris from entering the pipeline. At the same time, the gravity filling and drainage pipeline and equipment are set in the second dam body and the special valve chamber at a reasonable elevation, which not only solves the problem of blocking the downstream river drainage outlet, but also reduces the previous problem of difficult blocking of the water intake and the risks caused by blocking. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a structural schematic diagram of an embodiment.

[0042] Figure 2 for Figure 1 AA section view.

[0043] Figure 3 for Figure 1 BB cross-sectional view.

[0044] Figure 4 for Figure 1 CC cross-sectional view.

[0045] Figure 5 It is an axonometric view of the pipelines and equipment in the embodiment.

[0046] In the figure: 1. Water collection tank; 2. Trash rack; 3. Repair water intake pipe Ⅰ; 4. Repair drainage main pipe Ⅰ; 5. Repair drainage branch pipe; 6. Repair water intake pipe Ⅱ; 7. Gravity filling drainage pipe; 701. Gravity filling drainage pipe Ⅰ; 702. Gravity filling drainage pipe Ⅱ; 8. Repair drainage main pipe Ⅱ; 801. Repair drainage main pipe Ⅱ-Ⅰ; 802. Repair drainage main pipe Ⅱ-Ⅱ; 9. Repair water intake isolation valve; 10. Repair drainage pump; 11. Water intake; 12. Backwash pipe; 13. Pressure transmitter; 14. Corrugated expansion Section; 15. Maintenance and drainage small pump; 16. Maintenance and isolation ball valve after large pump; 17. Pressure-building gate valve after large pump; 18. Hydraulic control valve after large pump; 20. Maintenance and isolation ball valve in front of large pump; 21. Maintenance and isolation ball valve in front of small pump; 22. Hydraulic control valve after small pump; 23. Pressure-building gate valve after small pump; 24. Maintenance and isolation ball valve after small pump; 25. Backwashing isolation ball valve; 26. Backwashing operation ball valve; 27. Flow meter; 28. Gravity filling and drainage maintenance valve; 29. ​​Flow filling and drainage operation valve; 30. Blind plate; 31. Flange. DETAILED DESCRIPTION

[0047] The present embodiment is a water cushion pond maintenance drainage and refilling water system, which is arranged in the second dam and has: a gravity-filling drainage pipe, a water collection tank, a maintenance drainage pipeline, a backwash pipeline and a control and monitoring system.

[0048] In this embodiment, the gravity filling and drainage pipe includes gravity filling and drainage pipe I and gravity filling and drainage pipe II. Both gravity filling and drainage pipe I and gravity filling and drainage pipe II connect the water cushion pond upstream of Erdao Dam and the river channel downstream. The ends of gravity filling and drainage pipe I and gravity filling and drainage pipe II connected to the downstream river channel are provided with flanges for installing blind plates.

[0049] A water collection pool is set up in the area where the center line of the bottom of the anti-arch water cushion pond connects with the second dam. A trash rack is installed in front of the water collection pool to prevent large and numerous boulders from falling into the water collection pool when the water cushion pond discharges flood water, so as to keep the water collection pool from being filled with boulders.

[0050] In this embodiment, the maintenance drainage pipeline includes a maintenance water intake pipe, a maintenance drainage main pipe I, a maintenance drainage branch pipe and a maintenance drainage main pipe II, wherein the maintenance water intake pipe has two maintenance water intake pipes I and one maintenance water intake pipe II, and maintenance water intake isolation valves are provided on maintenance water intake pipes I and II. The water intakes of maintenance water intake pipes I and II are connected to the water collection tank and are provided with trash racks. The water intake of maintenance water intake pipe I is arranged at an elevation higher than the bottom elevation of the water cushion pond, and the water intake of maintenance water intake pipe II is arranged at an elevation lower than the bottom elevation of the water cushion pond, which can avoid being blocked by debris in the water body in the pond as much as possible, and ensure that a large amount of accumulated water in the water cushion pond is pumped out to the downstream river through this channel, located at the bottom of the water collection pit, so as to automatically collect a small amount of leaked accumulated water in the water cushion pond after the water collection tank is desilted.

[0051] In this example, the outlets of two maintenance water intake pipes Ⅰ and one maintenance water intake pipe Ⅱ are commonly connected to the maintenance drainage main pipe Ⅰ, and the maintenance drainage main pipe Ⅰ is provided with a corrugated expansion joint.

[0052] In this embodiment, the maintenance drainage main pipe II is divided into the maintenance drainage main pipe II-I and the maintenance drainage main pipe II-II. The maintenance drainage main pipe II-I is connected to the gravity filling and drainage pipe I through a tee, and the maintenance drainage main pipe II-II is connected to the gravity filling and drainage pipe II through a tee. A horizontal connection is adopted to prevent mud and sand from entering the maintenance drainage main pipe II and causing siltation in the maintenance drainage main pipe II. On the gravity filling and drainage pipe I and the gravity filling and drainage pipe II, an upstream filling and drainage valve group is installed upstream of the tee and a downstream filling and drainage valve group is installed downstream of the tee. The upstream filling and drainage valve group includes a gravity filling and drainage inspection valve and a gravity filling and drainage operating valve, and the downstream filling and drainage valve group includes a gravity filling and drainage operating valve and a gravity filling and drainage inspection valve.

[0053] In this example, the elevation of the part where the gravity-filled drainage pipes Ⅰ and Ⅱ are connected to the maintenance drainage main pipes Ⅱ-Ⅰ and Ⅱ-Ⅱ is higher than the elevation of the ports at both ends, avoiding the impact of upstream and downstream sedimentation on the water cushion pond maintenance drainage system and ensuring the smooth flow of system pipelines and equipment. The maintenance drainage main pipes Ⅱ-Ⅰ and Ⅱ-Ⅱ are horizontally connected to the corresponding gravity-filled drainage pipes Ⅰ and Ⅱ to prevent sediment from entering the maintenance drainage main pipes Ⅱ-Ⅰ and Ⅱ-Ⅱ.

[0054] In this embodiment, the maintenance drainage main pipe Ⅰ and the maintenance drainage main pipe Ⅱ-Ⅰ are connected through a number of maintenance drainage branch pipes, some of the maintenance drainage branch pipes are equipped with small maintenance drainage pumps, and the remaining maintenance drainage branch pipes are equipped with large maintenance drainage pumps; the maintenance drainage main pipe Ⅰ and the maintenance drainage main pipe Ⅱ-Ⅰ are connected through a number of maintenance drainage branch pipes, and the maintenance drainage branch pipes are equipped with large maintenance drainage pumps.

[0055] In this case, the inspection and drainage branch pipe in front of the large inspection and drainage pump is equipped with an inspection and isolation ball valve in front of the large pump, and the inspection and drainage branch pipe behind the pump is equipped with a hydraulic control valve behind the large pump, a pressure-building gate valve behind the large pump, and an inspection and isolation ball valve behind the large pump. The inspection and drainage branch pipe in front of the small inspection and drainage pump is equipped with an inspection and isolation ball valve in front of the small pump, and the inspection and drainage branch pipe behind the pump is equipped with a hydraulic control valve behind the small pump, a pressure-building gate valve behind the small pump, and an inspection and isolation ball valve behind the small pump.

[0056] In this embodiment, the backwash pipeline includes a backwash pipe, as well as a maintenance water intake pipe II, a maintenance drainage main pipe I, a maintenance drainage main pipe II-I and a gravity filling drainage pipe I in the maintenance drainage pipeline. The maintenance drainage main pipe I and the maintenance drainage main pipe II-I are connected through the backwash pipe. A backwash valve group is installed on the backwash pipe, and the backwash valve group includes a backwash operation ball valve and a backwash isolation ball valve.

[0057] In this embodiment, a flow meter and a pressure transmitter are connected in the control monitoring system circuit, wherein the flow meter is installed on the gravity filling and drainage pipe to obtain the flow change in the gravity filling and drainage pipe; the pressure transmitter is on the maintenance drainage main pipe I, and two pressure transmitters are provided to monitor the water level of the water collection tank in the water cushion pond.

[0058] The method for repairing and draining a water cushion pond in this embodiment comprises the following steps:

[0059] The maintenance and drainage of the cushion pond is generally arranged to discharge the accumulated water in the cushion pond to the downstream when the downstream water level is low. The maintenance and drainage of the cushion pond and the gravity filling drainage pipe in the refill water system are used as much as possible to discharge the accumulated water in the cushion pond to the downstream, so as to reduce the energy consumption of the system operation.

[0060] Open the gravity filling and drainage inspection valve and gravity filling and drainage operation valve on the gravity filling and drainage pipe, connect the upstream water cushion pond and the downstream river channel of Erdao Dam through the gravity filling and drainage pipe, and discharge all the water in the water cushion pond that is higher than the water level of the downstream river channel into the downstream river channel.

[0061] The water level in the cushion pond and the downstream river channel can be determined based on the flow signal changes of the flow meter on the gravity-filled drainage pipe.

[0062] When the water level in the cushion pond is basically the same as the water level in the downstream river, close the gravity filling and drainage operating valves upstream of the three-way valve on the gravity filling and drainage pipe, open the maintenance water intake isolation valve on the maintenance water intake pipe Ⅰ with a higher elevation of the water intake, and introduce the water with better water quality in the cushion pond into the front of the pump equipment of the pumping and drainage system composed of large and small pumps.

[0063] Using local control equipment, power distribution equipment, power cables, data optical fibers, control monitoring systems and other related equipment, start several large drainage pumps for maintenance, pump the water in the cushion pond to the vicinity of the two water intakes of maintenance water pipe I set at higher elevations, and stop pumping water from the large drainage pumps for maintenance.

[0064] Close the maintenance water intake isolation valve on the maintenance water intake pipe I, close the maintenance isolation ball valve in front of the large pump and the maintenance isolation ball valve in front of the small pump, open the backwash pipe operating ball valve and the backwash pipe isolation ball valve, open the maintenance water intake isolation valve on the maintenance water intake pipe II, and use the water pressure of the downstream tail water that is higher than the water level in the upstream water cushion pond to flush the trash rack and maintenance water intake pipe II in and in front of the collection pool.

[0065] After flushing is completed, close the backwash pipe operating ball valve and the backwash pipe isolation ball valve on the backwash pipe, open the maintenance isolation ball valve in front of the large pump and the maintenance isolation ball valve in front of the small pump, and use several large maintenance drainage pumps and small maintenance drainage pumps to drain the remaining water in the water cushion pond.

[0066] The large drainage pump for maintenance is shut down, and the small drainage pump for maintenance is switched to automatic operation mode. The water level in the water collection tank in the water cushion pond is monitored using the signals of the two pressure transmitters set on the maintenance drainage pipe Ⅰ, and the small drainage pump for maintenance is controlled to discharge the accumulated water in the water collection tank in the water cushion pond.

[0067] In this embodiment, the method for refilling water after the water cushion pond is repaired includes the following steps:

[0068] Open the gravity filling and drainage inspection valve, gravity filling and drainage operation valve, etc. on the gravity filling and drainage pipe, and connect the upstream water cushion pond and downstream river channel of Erdao Dam through the gravity filling and drainage pipe.

[0069] Taking advantage of the fact that the water level in the downstream river is higher than the bottom plate elevation of the cushion pond, the water downstream of Erdao Dam can be gravity-flown back into the cushion pond through the gravity-filled drainage pipe.

[0070] The data monitoring transmitted by the flow meter installed on the gravity filling and drainage pipe can monitor the water flow passing through the gravity filling and drainage pipeline, and then determine whether the water filling is completed.

[0071] When the water filling is completed, close the gravity filling and drainage operating valve on the gravity filling and drainage pipeline.

[0072] When the cushion pond discharges floodwater, the deep hole emergency gate of the dam can be partially opened to first fill the cushion pond with water to the elevation of the Erdao Dam crest, and then the deep hole emergency gate of the dam can be fully opened to meet the flood discharge requirements.

[0073] In this embodiment, the equipment maintenance of the water cushion pond drainage system is divided into two levels. The first level of operation steps is: first close the filling and drainage valve group on the gravity filling and drainage pipe to achieve the purpose of cutting off the water in the upstream water cushion pond and the downstream river water, and realize the maintenance of all remaining equipment in the drainage pump room and gravity filling and drainage valve room of the Erdao dam body. The second level of operation steps is to first drain the water in the water cushion pond, and then tighten the blind plate with the flange on the gravity filling and drainage pipe to cut off the downstream water, so as to realize the maintenance of all equipment in the drainage pump room and gravity filling and drainage valve room of the Erdao dam body.

[0074] For water conservancy and hydropower projects with large water cushion ponds, after adopting the safe and reliable water cushion pond filling and drainage system of the present invention, the main pumping and drainage equipment, power distribution equipment and lifting equipment can be arranged at appropriate positions in the second dam to meet the needs of maintenance and pumping and drainage in the water cushion pond; maintenance water intake pipes with water intakes at different elevations are set, and the gravity filling and drainage valve chamber is set at a higher position. The gravity filling and drainage pipe is combined with the main pumping and drainage pipe and arranged at an elevation above the downstream riverbed and arranged along the slope, which can avoid the influence of siltation upstream and downstream of the second dam on the water cushion pond maintenance and drainage system to the greatest extent, and ensure the smooth flow of system pipelines and equipment; the gravity filling and drainage valve chamber is arranged in the corridor on one side of the water cushion pond, and the slope of the water cushion pond and the bottom plate can be used to avoid the impact of high-speed water flow on the bottom plate when the water cushion pond is filled with water, which plays a good energy dissipation role, thereby greatly improving the anti-blockage, anti-humidity and anti-valley extrusion deformation capabilities of the water cushion pond maintenance and drainage system. At the same time, the system can also be set up with on-site operation and remote control monitoring systems, which can realize automatic filling and drainage control, and is easy for operators to operate, avoiding the cumbersome construction of temporary filling and drainage systems and the safety hazards of system operation, and can ensure the stable operation of the water cushion pond. At the same time, the system does not require additional investment, saves filling and drainage time during maintenance, and greatly improves the filling and drainage efficiency of the water cushion pond; in addition, the system greatly reduces the power consumed during filling and drainage, and the technical solution is more energy-saving and environmentally friendly.

Claims

1. A water cushion pond maintenance drainage and refilling system, arranged in the second dam, characterized in that: have: A gravity filling and drainage pipe (7) connecting the upstream cushion pond of Erdaoba and the downstream river channel, and equipped with a filling and drainage valve group; A flow meter, installed on the gravity filling and drainage pipe (7), for obtaining flow changes in the gravity filling and drainage pipe (7); A water collection pool (1) is arranged at the bottom of the water cushion pond and in the area connected to the second dam, and a trash rack (2) is arranged at the water inlet of the water collection pool; The maintenance drainage pipeline comprises a maintenance water intake pipe, a maintenance drainage main pipe I (4), a maintenance drainage branch pipe (5) and a maintenance drainage main pipe II (8), wherein one end of the maintenance water intake pipe is connected to the water collection tank (1), and the other end of the maintenance water intake pipe is connected to the maintenance drainage main pipe I (4), the maintenance drainage main pipe I (4) and the maintenance drainage main pipe II (8) are connected via a plurality of maintenance drainage branch pipes (5), and the outlet of the maintenance drainage main pipe II (8) is connected to a downstream river; wherein the maintenance water intake pipe is provided with a maintenance water intake isolation valve (9), and the maintenance drainage branch pipe (5) is provided with a maintenance drainage pump; A backwash pipe (12) includes the maintenance water intake pipe, the maintenance drainage main pipe I (4) and the maintenance drainage main pipe II (8), wherein the maintenance drainage main pipe I (4) is connected to the maintenance drainage main pipe II (8) via a backwash pipe (12), and a backwash valve group is provided on the backwash pipe (12); A pressure transmitter (13) installed on the main maintenance drainage pipe I (4) for monitoring the water level of the water collection tank (1) in the cushion pond; A control monitoring system, connected to the flow meter and the pressure transmitter (13) in an electrical circuit; The maintenance water intake pipe is divided into maintenance water intake pipe I (3) and maintenance water intake pipe II (6), wherein the water intake ports (11) of the maintenance water intake pipes I and II are respectively located at different heights in the water collection tank (1); The outlet of the maintenance drainage main pipe II (8) is connected to the gravity filling and drainage pipe (7) via a tee, and the filling and drainage valve group includes an upstream filling and drainage valve group located upstream of the tee and a downstream filling and drainage valve group located downstream of the tee; The elevation of the portion of the gravity-filled drainage pipe (7) connected to the main maintenance drainage pipe II (8) is higher than the elevation of the ports at both ends thereof; The gravity filling and drainage pipe (7) is divided into a gravity filling and drainage pipe I (701) connected to the maintenance drainage main pipe II-I (801) and a gravity filling and drainage pipe II (702) connected to the maintenance drainage main pipe II-II (802); A trash rack (2) is provided at the water intake (11) of the maintenance water intake pipe.

2. The water cushion pond maintenance drainage and refilling system according to claim 1 is characterized by: The maintenance drainage pumps on some of the maintenance drainage branch pipes (5) are small maintenance drainage pumps (15), and the maintenance drainage pumps on the remaining maintenance drainage branch pipes (5) are large maintenance drainage pumps (10).

3. The water cushion pond maintenance drainage and refilling system according to claim 2 is characterized by: The maintenance drainage main pipe II (8) is divided into the maintenance drainage main pipe II-I (801) and the maintenance drainage main pipe II-II (802). The maintenance drainage small pump (15) and part of the maintenance drainage large pumps (10) are connected to the maintenance drainage main pipe II-I (801), and the remaining maintenance drainage large pumps (10) are connected to the maintenance drainage main pipe II-II (802).

4. The water cushion pond maintenance drainage and refilling system according to claim 1, characterized in that: The end of the gravity filling and drainage pipe (7) connected to the downstream river channel is provided with a flange (31) capable of installing a blind plate (30).

5. A drainage method for the water cushion pond maintenance drainage and refilling water system according to any one of claims 1 to 4, characterized in that: Open the filling and drainage valve group on the gravity filling and drainage pipe (7) to discharge all the water in the cushion pond that is higher than the water level of the downstream river into the downstream river; According to the flow signal change of the flow meter on the gravity filling and drainage pipe (7), the water level in the cushion pond and the water level in the downstream river channel are judged; When the water level of the cushion pond is substantially equal to the water level of the downstream river channel, the filling and drainage valve group is closed, and the maintenance water intake isolation valve (9) on the maintenance water intake pipe Ⅰ (3) is opened to introduce the water in the cushion pond into the maintenance drainage pump through the maintenance water intake pipe Ⅰ (3), the maintenance drainage main pipe Ⅰ (4), and the maintenance drainage branch pipe (5); Start several maintenance drainage pumps to pump water from the cushion pond until the water level reaches the vicinity of the water intake port (11) of the maintenance water intake pipe Ⅰ (3), stop the maintenance drainage pumps from pumping water, and close the maintenance water intake isolation valve (9) on the maintenance water intake pipe Ⅰ (3); Open the backwash valve group on the backwash pipe (12), open the maintenance water intake isolation valve (9) on the maintenance water intake pipe II (6), and use the water pressure of the downstream tail water that is higher than the water level in the upstream water cushion pond to flush the trash rack (2) and the maintenance water intake pipe II (6); After flushing is completed, close the backwash valve group and use several maintenance drainage pumps to drain the remaining water in the water cushion pond; The water level in the water collecting tank (1) in the water cushion pond is monitored by using the signal of the pressure transmitter (13) arranged on the main maintenance drainage pipe I (4), and a plurality of maintenance drainage pumps are controlled to discharge the accumulated water in the water collecting tank (1) in the water cushion pond.

6. A method for recharging water for the water cushion pond maintenance drainage and recharging water system according to any one of claims 1 to 4, characterized in that: Open the filling and drainage valve group on the gravity filling and drainage pipe (7), and use the water level of the downstream river channel to be higher than the bottom plate elevation of the water cushion pond, so that the water downstream of the Erdao Dam is gravity-flowed back to the water cushion pond through the gravity filling and drainage pipe (7); The water flow rate passing through the gravity filling and drainage pipe (7) is monitored by data transmitted by a flow meter arranged on the gravity filling and drainage pipe (7), thereby judging whether the water filling is completed; When the water filling is completed, the filling and drainage valve group on the gravity filling and drainage pipe (7) is closed.

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