Multi-purpose protection channel suitable for water pumping and storage reservoir and operation method of multi-purpose protection channel

Abstract

The invention provides a multi-purpose protection channel suitable for a water pumping and storage reservoir and an operation method of the multi-purpose protection channel. The multi-purpose protection channel is arranged on the outer side of a reservoir surrounding road of an upper reservoir or a lower reservoir of a water pumping and storage power station with one or more gullies. The multi-purpose protection channel comprises a water conveying channel section arranged in the direction of the reservoir surrounding road, the outer side of the water conveying channel section is connected with one or more gully bodies, and water outlets are formed in the two ends of the water conveying channel section. A water replenishing port gate is arranged at the first end water outlet, and the other side of the water replenishing port gate is communicated with a reservoir bank retaining wall of an upper reservoir or a lower reservoir of the pumped storage power station; an overflow weir is arranged at the second end water outlet, the downstream of the overflow weir is used for being connected with a spillway, and the spillway is located beside the upper or lower reservoir dam and is directly communicated with a downstream river channel; and the weir crest elevation of the water replenishing port gate is lower than that of the overflow weir and is higher than the normal water storage level of the reservoir. On the basis of effectively intercepting mountain torrent silt and defending geological disasters, clean incoming water can be introduced into the reservoir to increase power generation benefits.

Description

Technical Field

[0001] This invention relates to the field of hydraulic structure design, construction, operation and management technology, and specifically to a multi-purpose protective canal suitable for pumped storage reservoirs and its operation method. Background Technology

[0002] Pumped storage power stations typically utilize natural valleys or depressions in mountainous areas for their upper and lower reservoirs. Due to their mountainous location, the surrounding terrain is often complex, with large catchment areas and multiple natural gullies. During the power station's operation, surface runoff from the surrounding mountains and gully water are significant factors influencing the reservoir's water environment. Currently, drainage designs for the area surrounding pumped storage power station reservoirs usually involve direct discharge into the reservoir or the installation of conventional intercepting or drainage ditches along the inner or outer sides of reservoir banks. This traditional, single-drainage approach has the following significant drawbacks in actual operation:

[0003] (1) Sedimentation and equipment wear. During heavy rain or floods in mountainous areas, the water flowing from the gullies often carries a large amount of sediment, rocks, and even dead branches and other debris. If this muddy water with a very high sediment content flows directly into the reservoir, it will cause sedimentation in the reservoir and reduce the effective regulating capacity of the reservoir. On the other hand, the high sediment content water flow entering the water conveyance and power generation system will cause serious wear and cavitation on the units, shorten the service life of the units, and increase the operation and maintenance costs.

[0004] (2) Waste of water resources and loss of power generation benefits. In order to avoid the above-mentioned sediment problems, existing designs often tend to intercept all the surrounding runoff through intercepting ditches and discharge it into the downstream river channel outside the reservoir. However, during the non-flood season or under normal rainfall conditions, the water flowing into the ditch is mostly clean water with good water quality. Discharging this part of the water not only wastes water resources, but also loses the precious water that could be used for power generation.

[0005] (3) Diversion problem during reservoir maintenance. When it is necessary to drain the reservoir for maintenance, it is necessary to ensure that the bottom of the reservoir is in a dry state. Existing drainage facilities are often unable to completely intercept the continuous water flow from the gully during the maintenance period, resulting in the continuous inflow of external water into the reservoir, which increases the difficulty and cost of drainage during maintenance, and may even affect the maintenance period.

[0006] (4) Insufficient geological disaster prevention capabilities. Mountainous areas are prone to natural disasters such as debris flows. Traditional intercepting and drainage ditches have simple cross-sectional forms and limited functions, lacking sedimentation, interception, and early warning mechanisms. Once a debris flow occurs, it can easily lead to siltation and overflow of drainage ditches, which in turn can destroy the ring road around the reservoir, and even a large amount of debris flow material can be directly rushed into the reservoir, posing a serious threat to the safety of the power station.

[0007] Therefore, developing a multi-purpose protective canal and its operation method suitable for pumped storage reservoirs that can effectively intercept sediment and prevent geological disasters, flexibly switch between "water replenishment" and "flood discharge and sediment removal" modes according to water quality conditions, and also meet the needs of reservoir maintenance and diversion, is an urgent technical problem to be solved in the current engineering design and operation management of pumped storage power stations. Summary of the Invention

[0008] This invention addresses the shortcomings of existing pumped storage power station reservoir bank drainage facilities, which have limited functionality and cannot simultaneously address water resource utilization and sediment protection. It provides a multi-purpose protection channel suitable for pumped storage reservoirs. This protection channel can effectively intercept mountain torrents and sediment and prevent geological disasters, while introducing clean water into the reservoir to increase power generation efficiency. At the same time, it provides reliable interception and diversion conditions for reservoir emptying and maintenance, ensuring the reservoir is in a dry maintenance state.

[0009] In a first aspect, the present invention provides a multi-purpose protective channel suitable for pumped storage reservoirs. The multi-purpose protective channel is arranged outside the ring road of the upper or lower reservoir of a pumped storage power station with one or more gullies, located between the ring road and the excavated slope. The multi-purpose protective channel includes a water conveyance section laid along the ring road, the outer side of which connects to the one or more gullies. Both ends of the water conveyance section are provided with outlets. A water replenishment gate is provided at the first outlet, the other side of which connects to the retaining wall of the upper or lower reservoir of the pumped storage power station. An overflow weir is provided at the second outlet, the downstream of which connects to a spillway located beside the dam of the upper or lower reservoir and directly leading to the downstream river channel. The crest elevation of the water replenishment gate is lower than the crest elevation of the overflow weir but higher than the normal water level of the reservoir.

[0010] As a preferred technical solution of the present invention: a slot is provided on the upper part of the side wall of the water conveyance channel section near the gully, and the slot is provided corresponding to the gully, so that the water flow in the gully can directly enter the water conveyance channel section through the slot.

[0011] As a preferred technical solution of the present invention: a sedimentation tank is provided on the outer side of the sidewall of the water conveyance channel section near the gully. The sedimentation tank is provided in accordance with the trench, and the bottom elevation of the sedimentation tank is lower than the weir crest elevation of the trench. When the gully has normal flow or muddy flash flood, the sedimentation tank can settle and intercept some of the mud and sand in the water flow.

[0012] As a preferred technical solution of the present invention: a sand-blocking sluice is set in the water conveyance channel section, the sand-blocking sluice is set on the upstream side of the first end outlet, and a water replenishment culvert is connected between the water replenishment gate and the reservoir bank retaining wall of the upper or lower reservoir.

[0013] As a preferred embodiment of the present invention, the crest elevation of the slotted weir is higher than the crest elevation of the overflow weir.

[0014] As a preferred embodiment of the present invention, the top elevation of the side walls of the multipurpose protective canal is higher than the top elevation of the ring road.

[0015] As a preferred technical solution of the present invention: an ecological bypass pipe with a control valve is provided at the bottom of the overflow weir, the inlet end of the ecological bypass pipe is connected to the upstream waterway of the overflow weir, and the outlet end is connected to the spillway.

[0016] Secondly, the second objective of this invention is to provide an operation method for a multi-purpose protective canal suitable for pumped storage reservoirs. This operation method can switch the water flow path by flexibly adjusting the gate of the water inlet under different working conditions such as normal inflow, sand-laden flash flood, reservoir maintenance, and debris flow. This maximizes the utilization of water resources while ensuring the flood control safety of the power station, and enables early warning and emergency response to sudden geological disasters.

[0017] When a gully experiences normal flow or a silty flash flood, any of the aforementioned multi-purpose protective channels are used. Water flows through a sedimentation basin to intercept some of the silt, and then enters the water conveyance channel section through the open channel. Operational control for different working conditions is achieved by controlling the opening and closing of the water inlet gate, including the following conditions:

[0018] A. Under normal operating conditions, the gully flows normally with low sand content in the water. The water inlet gate is kept open, which can introduce the water from the gully into the water conveyance canal into the upper or lower reservoir to replenish the water lost in the upper or lower reservoir or increase the water volume for power generation.

[0019] B. During flood discharge, if a muddy flash flood occurs in the gully, the water flow contains a large amount of sediment. The water in the water inlet gate is closed, and the water in the section of the gully that flows into the water conveyance canal is discharged into the downstream river channel through the spillway.

[0020] C. During maintenance, the reservoir needs to be emptied for maintenance, the water inlet gate is closed, and the multi-purpose protection canal acts as a diversion and drainage canal during the maintenance period. The water that flows into the water conveyance canal from the gully is discharged into the downstream river through the spillway to ensure that the reservoir is in a dry maintenance state.

[0021] D. In ecological maintenance mode, when there is a need for ecological water use in the downstream river during the dry season, the control valve of the ecological bypass pipe is opened to directly introduce the water flow in the water conveyance section into the spillway and discharge it into the downstream river to maintain the ecological flow of the downstream river.

[0022] As a preferred technical solution of the present invention: when a debris flow occurs in the gully, the gate of the water inlet is closed, the sedimentation tank intercepts a portion of the solid material, and the remaining solid-liquid mixture of debris flow enters the water conveyance channel through the trench. The solid material is deposited in the water conveyance channel, and the dilute material is discharged into the downstream river through the spillway. After the debris flow occurs and during daily operation, a small excavator can be used to remove the solid material deposited in the water conveyance channel.

[0023] The beneficial effects of the multi-purpose protective canal and its operation method for pumped storage reservoirs provided by this invention are as follows:

[0024] (1) It realizes the classified utilization of water resources and the protection of the unit. By regulating the gate of the water inlet, the "clean water and sewage separation" can be realized. It can not only introduce clean water into the reservoir to increase the amount of water for power generation, but also effectively intercept the mud and floating objects in the flood, avoid reservoir siltation and turbine wear, and solve the contradiction between water resource waste and equipment protection.

[0025] (2) This invention solves the problem of interception during reservoir maintenance and saves engineering investment. It can be used directly as a permanent diversion facility during reservoir emptying and maintenance, completely intercepting the water from the gully and discharging it downstream. There is no need to build a temporary maintenance cofferdam to ensure the dry maintenance state of the reservoir, which significantly shortens the construction period and reduces costs.

[0026] (3) A comprehensive physical protection barrier integrating water interception, rock blocking and isolation was constructed. By utilizing the hardened structure of the protective canal and the high design of the side wall near the ditch, this invention can effectively intercept and drain rainwater on the slope and prevent slope erosion, while also effectively intercepting rockfalls and debris flow solids on the slope and playing a physical isolation role to prevent wild animals from accidentally entering the reservoir area and improve the overall safety of the reservoir bank.

[0027] (4) Taking into account the ecological and environmental benefits, in response to the problem of easy flow interruption of mountain rivers, this invention realizes the ecological water replenishment function of downstream river channels during the dry season or at other times by adding an ecological flow bypass valve at the overflow weir, avoiding the downstream river channels from drying up due to interception, meeting the environmental protection requirements of the project construction, and achieving the harmonious unity of project safety, resource utilization and ecological protection. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a plan view of the multi-purpose protective canal, reservoir, dam, and gully of the present invention.

[0030] Figure 2 This is a plan view of the multi-purpose protective canal of the present invention.

[0031] Figure 3 yes Figure 2 Longitudinal section view along the DD direction.

[0032] Figure 4 yes Figure 3 A cross-sectional view along the AA direction.

[0033] Figure 5 yes Figure 3 A cross-sectional view along the BB direction.

[0034] Figure 6 yes Figure 3 A cross-sectional view along the CC direction.

[0035] Attached reference numerals: 1. Multipurpose protective canal; 2. Upper or lower reservoir; 3. Reservoir ring road; 4. Excavated slope; 5. Sedimentation basin; 6. Upper or lower reservoir dam; 7. Spillway; 8. Overflow weir; 9. Side wall of water conveyance canal section near the gully; 10. Trench; 11. Side wall of protective canal near the reservoir; 12. Water replenishment culvert; 13. Water replenishment gate; 14. Sand retaining wall; 15. First outlet; 16. Ecological bypass pipe with control valve; 17. Second outlet; 18. Reservoir bank retaining wall; 19. Gully. Detailed Implementation

[0036] To enable those skilled in the art to better understand the technical solutions of the present invention, preferred embodiments of the present invention are described below in conjunction with specific examples. However, it should be understood that the accompanying drawings are for illustrative purposes only and should not be construed as limiting the present invention. For better illustration of this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable that some well-known structures and their descriptions may be omitted in the drawings for those skilled in the art. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting the present invention.

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0038] like Figures 1-6As shown, a multi-purpose protective canal suitable for pumped storage reservoirs is provided. The multi-purpose protective canal 1 is arranged outside the ring road 3 of the upper or lower reservoir 2 of a pumped storage power station with one or more gullies 18, located between the ring road 3 and the excavated slope 4. The multi-purpose protective canal 1 includes a water conveyance section laid along the direction of the ring road 3. The outer side of the water conveyance section is connected to one or more gullies 18. Water outlets are provided at both ends of the water conveyance section. A water replenishment device is provided at the first end outlet 15. The water inlet gate 13 is located on the side wall 11 of the water conveyance channel section near the reservoir. The other side of the water inlet gate 13 is connected to the bank retaining wall 18 of the upper or lower reservoir 2 of the pumped storage power station. An overflow weir 8 is set at the second outlet 17. The downstream of the overflow weir 8 is used for the connection of the spillway 7. The spillway 7 is located next to the dam 6 of the upper or lower reservoir and leads directly to the downstream river channel. The crest elevation of the water inlet gate 13 is lower than the crest elevation of the overflow weir 8 and higher than the normal water level of the reservoir.

[0039] A slot 10 is provided on the upper part of the side wall 9 on the side of the water conveyance channel 19, and the slot 10 is provided in correspondence with the gully 19, so that the water flow in the gully 19 can directly enter the water conveyance channel 19 through the slot 10.

[0040] A sedimentation tank 5 is provided on the outer side of the sidewall 9 on the side of the water conveyance channel near the gully. The sedimentation tank 5 is provided in correspondence with the trench 10, and the bottom elevation of the sedimentation tank 5 is lower than the top elevation of the weir of the trench 10. When the gully 19 has normal flow or muddy flash flood, the sedimentation tank 5 can settle and intercept some of the mud and sand in the water flow.

[0041] A sand-blocking sluice 14 is installed in the water conveyance channel section. The sand-blocking sluice 14 is located on the upstream side of the first outlet 15. A water replenishment culvert 12 is connected between the water replenishment gate 13 and the bank retaining wall 18 of the upper or lower reservoir 2.

[0042] A debris flow alarm and video monitoring system are installed in the gully 19. Flow meters are installed in both the water supply culvert 12 and the gully 19. The flow meters, debris flow alarm, video monitoring system, and water supply gate 13 are connected to the central control room. Specifically, the water supply gate 13 is controlled by the central control room and has automatic or remote manual control opening and closing functions.

[0043] The crest elevation of the slot 10 is higher than the crest elevation of the overflow weir 8.

[0044] The top elevation of the side walls of the multi-purpose protective canal 1 is higher than the top elevation of the ring road 3.

[0045] An ecological bypass pipe 16 with a control valve is installed at the bottom of the overflow weir 8. The inlet end of the ecological bypass pipe is connected to the upstream waterway of the overflow weir 8, and the outlet end is connected to the spillway 7.

[0046] This invention also provides an operation method for a multi-purpose protective channel suitable for pumped storage reservoirs. When a gully experiences normal inflow or a silt-laden flash flood, the multi-purpose protective channel 1 described above is used. The water flows through a sedimentation tank 5 to intercept some of the silt and enters the water conveyance channel section through the opening 10. Operation control under different working conditions is achieved by controlling the opening and closing of the water inlet gate 13, including the following working conditions:

[0047] A. Under normal operating conditions, the gully 19 flows normally with low sand content. The water inlet gate 13 remains open. Since the crest elevation of the water inlet gate 13 is lower than the crest elevation of the overflow weir 8, the water flowing into the water conveyance channel from the gully can be introduced into the upper or lower reservoir 2 to replenish the water lost in the upper or lower reservoir 2 or increase the water volume for power generation.

[0048] B. During flood discharge, a muddy flash flood occurs in gully 19, with a high sand content in the water flow. The water inlet gate 13 is closed, and the water in the section of gully 19 that flows into the water conveyance canal is discharged into the downstream river channel through the spillway 7.

[0049] C. During maintenance, the reservoir needs to be emptied for maintenance. The water inlet gate 13 is closed, and the multi-purpose protection channel 1 acts as a drainage channel during the maintenance period. The water that flows into the water conveyance channel from the gully 19 is discharged into the downstream river channel through the spillway 7 to ensure the dry maintenance state of the reservoir.

[0050] D. In ecological maintenance mode, when there is a need for ecological water use in the downstream river during the dry season, the control valve of the ecological bypass pipe is opened to directly introduce the water flow in the water conveyance section into the spillway 7 and discharge it into the downstream river to maintain the ecological flow of the downstream river.

[0051] Specifically, each gully 19 is equipped with a flow meter to monitor the flow rate of the gully; each water supply culvert 12 is equipped with a flow meter to monitor the flow rate of the water supply culvert. When the flow rate of the water supply culvert is too small, the opening of the water supply gate 13 can be increased; when the flow rate of the water supply culvert is too large, the opening of the water supply gate 13 can be decreased.

[0052] The debris flow alarm and video monitoring system should be kept in operation for a long time. When a debris flow occurs in the gully, the debris flow alarm and video monitoring system, together with the flow meter in the gully, will detect and warn in advance. The water inlet gate 13 will be closed in time through automatic or manual remote control. The sedimentation tank 5 will intercept a portion of the solid material. The remaining debris flow solid-liquid mixture will enter the water conveyance channel through the trench 10. The solid material will be deposited in the water conveyance channel, and the dilute material will be discharged into the downstream river through the spillway 7. After a debris flow occurs and during daily operation, a small excavator can be used to remove the solid material deposited in the water conveyance channel.

[0053] Based on the description and accompanying drawings of this invention, those skilled in the art can easily manufacture or use the multipurpose protective canal and its operation method applicable to pumped storage reservoirs, and can achieve the positive effects described in this invention.

[0054] Unless otherwise specified, in this invention, terms such as "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe orientation or positional relationships in this invention are for illustrative purposes only and should not be construed as limiting this invention. For those skilled in the art, the specific meaning of the above terms can be understood in conjunction with the accompanying drawings and according to the specific circumstances.

[0055] Unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" in this invention should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A multi-purpose protective canal suitable for pumped storage reservoirs, characterized in that: The multi-purpose protective canal is located outside the ring road of the upper or lower reservoir of a pumped storage power station with one or more gullies, between the ring road and the excavated slope. The multi-purpose protective canal includes a water conveyance section laid along the ring road, the outer side of which connects to the one or more gullies, and both ends of the water conveyance section are provided with outlets. A water inlet gate is provided at the first outlet, and the other side of the water inlet gate is connected to the retaining wall of the upper or lower reservoir of the pumped storage power station. An overflow weir is provided at the second outlet, and the downstream of the overflow weir is used to connect to the spillway, which is located next to the dam of the upper or lower reservoir and leads directly to the downstream river channel. The crest elevation of the water inlet gate is lower than that of the overflow weir but higher than the normal water level of the reservoir.

2. The multi-purpose protective canal for pumped storage reservoirs according to claim 1, characterized in that: A slot is provided on the upper part of the side wall of the water conveyance channel section on the side of the gully. The slot is provided in a way that corresponds to the gully, so that the water in the gully can flow directly into the water conveyance channel section through the slot.

3. The multi-purpose protective canal suitable for pumped storage reservoirs according to claim 2, characterized in that: A sedimentation basin is installed on the outer side of the sidewall of the water conveyance channel section near the gully. The sedimentation basin is set up corresponding to the trench, and the bottom elevation of the sedimentation basin is lower than the weir crest elevation of the trench. This allows the sedimentation basin to settle and intercept some of the sediment in the flowing water when the gully has normal flow or when there is a muddy flash flood.

4. The multi-purpose protective canal for pumped storage reservoirs according to claim 1, characterized in that: A sand-blocking sluice is installed within the water conveyance channel section. The sand-blocking sluice is located upstream of the first outlet. A water replenishment culvert connects the water replenishment gate to the retaining wall of the upper or lower reservoir.

5. The multi-purpose protective canal suitable for pumped storage reservoirs according to claim 2, characterized in that: The crest elevation of the slotted weir is higher than the crest elevation of the overflow weir.

6. The multi-purpose protective canal for pumped storage reservoirs according to claim 1, characterized in that: The top elevation of the side walls of the multi-purpose protective canal is higher than the top elevation of the ring road.

7. The multi-purpose protective canal suitable for pumped storage reservoirs according to claim 1, characterized in that: An ecological bypass pipe with a control valve is installed at the bottom of the overflow weir. The inlet end of the ecological bypass pipe is connected to the upstream waterway of the overflow weir, and the outlet end is connected to the spillway.

8. An operation method for a multi-purpose protective canal suitable for pumped storage reservoirs, characterized in that, When a gully experiences normal flow or a silty flash flood, the multi-purpose protective channel described in any one of claims 1-7 is used. The water flows through a sedimentation basin to intercept some of the silt and enters the water conveyance channel section through the open channel. Operation control under different working conditions is achieved by controlling the opening and closing of the water inlet gate, including the following working conditions: A. Under normal operating conditions, the gully flows normally with low sand content in the water. The water inlet gate is kept open, which can introduce the water from the gully into the water conveyance canal into the upper or lower reservoir to replenish the water lost in the upper or lower reservoir or increase the water volume for power generation. B. During flood discharge, if a muddy flash flood occurs in the gully, the water flow contains a large amount of sediment. The water in the water inlet gate is closed, and the water in the section of the gully that flows into the water conveyance canal is discharged into the downstream river channel through the spillway. C. During maintenance, the reservoir needs to be emptied for maintenance, the water inlet gate is closed, and the multi-purpose protection canal acts as a diversion and drainage canal during the maintenance period. The water that flows into the water conveyance canal from the gully is discharged into the downstream river through the spillway to ensure that the reservoir is in a dry maintenance state. D. In ecological maintenance mode, when there is a need for ecological water use in the downstream river during the dry season, the control valve of the ecological bypass pipe is opened to directly introduce the water flow in the water conveyance section into the spillway and discharge it into the downstream river to maintain the ecological flow of the downstream river.

9. The operating method according to claim 8, characterized in that: When a debris flow occurs in the gully, the inlet gate is closed, the sedimentation tank intercepts some of the solid material, and the remaining solid-liquid mixture of debris flow enters the water conveyance channel through the trench. The solid material is deposited in the water conveyance channel, and the dilute material is discharged into the downstream river through the spillway. After a debris flow occurs and during daily operation, a small excavator can be used to remove the deposited solid material in the water conveyance channel.

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