Gate dam transforming and upgrading method adapting to downstream multi-target ecological flow demand

Abstract

The invention relates to the technical field of water conservancy and hydropower engineering, in particular to a gate dam transforming and upgrading method capable of meeting the downstream multi-target ecological flow demand, which comprises the following steps: S1, newly building an upstream side gate dam at the upstream of an original gate dam, and newly building a downstream side gate dam at the downstream of the original gate dam; s2, an original gate dam is transformed, a high gate dam is changed into a low gate dam, the water retaining function is reserved, and a disassembled gate dam is formed; s3, ecological water release gates are built on dam abutments on one side or two sides of the detached gate dam in a supplementary mode; and S4, a new fishway is built at the position between the ecological drainage gate and the shoreside, and the ecological drainage gate is used for keeping normal drainage throughout the year to supplement water for the newly-built fishway. By adopting the method provided by the invention, the upgrading and reconstruction of the original gate dam not only contributes to the improvement of the ecological environment, but also can improve the efficiency and benefit of water resource management, and has remarkable environmental and economic benefits.

Description

Technical Field

[0001] The present invention relates to the field of water conservancy and hydropower engineering technology, and in particular to a method for upgrading a dam to meet downstream multi-objective ecological flow requirements. Background Art

[0002] The service life of dam projects is usually several decades to hundreds of years. After long-term operation, their structures will age and become damaged, and there will be weak links and safety hazards.

[0003] Many dams and locks are large or very large projects, such as the Three Gorges Dam and the Xiaolangdi Reservoir. Dams and locks are widely distributed throughout the country, especially in major river basins such as the Yangtze River and the Yellow River. They serve a variety of purposes, including flood control, irrigation, hydropower generation, water supply and navigation. At present, the main function of these dams and locks is to regulate water flow. On the one hand, they regulate the flow of upstream cascade power stations and provide peak load regulation services. On the other hand, dams and locks also guarantee the minimum flow requirements downstream to maintain the ecological flow of the river channel and support aquatic life, farmland irrigation and domestic water.

[0004] However, existing research mainly focuses on the risk management, safety and stability, and intelligent construction of dams and gates, and rarely considers how to transform existing dams and gates to adapt to the actual flow demand downstream, so as to maximize the satisfaction of multi-objective ecological flow. With the maturity of the integrated energy architecture system of water, wind and solar power bases in various river basins, the development of wind and solar energy has had an impact on hydropower, resulting in changes in the downstream flow of hydropower. This especially affects the discharge requirements of existing or newly built dams and gates downstream of high dams and reservoirs, which need to be adjusted to increase the discharge volume to meet the multi-objective ecological flow requirements downstream.

[0005] To sum up, under the development trend of upgrading existing dams and multi-energy complementary pattern of hydropower stations, how to transform and upgrade existing dams while ensuring the safe operation of dams to meet the downstream ecological flow, water demand requirements of aquatic organisms and scheduling flexibility, and improve the efficiency and benefits of water resources management, is an urgent problem that needs to be solved. Summary of the invention

[0006] The main purpose of the present invention is to propose a method for upgrading a dam and gate that can adapt to the downstream multi-objective ecological flow requirements. Starting from the perspective of upgrading the counter-regulation dam and gate, it is guided by the flexibility of downstream ecological flow, ecological discharge, fish-passing facility inlet water replenishment and operation scheduling to meet the requirements of fish-passing, so as to adapt to the goal of downstream multi-objective ecological flow requirements, thereby changing the existing counter-regulation dam operation mode or the downstream multi-objective ecological problems faced when designing a new dam and gate.

[0007] To achieve the above object, the present invention proposes a dam renovation and upgrading method that adapts to the downstream multi-objective ecological flow requirements, comprising the following steps:

[0008] S1. Build a new upstream dam upstream of the original dam, and a new downstream dam downstream of the original dam;

[0009] S2. Reconstruct the original dam from a high dam to a low dam, retaining the water retaining function to form a post-demolition dam;

[0010] S3. Build an ecological spillway on one or both sides of the dam shoulder after demolition;

[0011] S4. Build a new fishway between the ecological spillway and the shore, and use the ecological spillway to maintain normal discharge all year round to replenish water for the newly built fishway.

[0012] Preferably, in step S1, during the process of constructing the new upstream dam and the downstream dam, the original dam always maintains normal water discharge or water storage function.

[0013] Preferably, the original dam is provided with gate piers, and a water discharge gate is provided on the gate piers; before the original dam is upgraded and renovated, the water discharge gate is required to be able to operate normally on the gate piers and have a long water discharge function.

[0014] Preferably, when the high dam is changed into a low dam in step S2, the original gate piers on the original dam are retained for flood discharge.

[0015] Preferably, when the upstream dam is built and operates normally, the highest water level formed in front of the original dam is H1. If the water intake layer of the original dam is higher than H1, it is necessary to perform step S2 to dismantle and renovate the original dam.

[0016] Preferably, the distance between the upstream dam and the original dam is L1, and the distance between the original dam and the downstream dam is L2. In step S2, when the original dam is renovated, it is required that both L1 and L2 are not less than the minimum safe flood control distance.

[0017] Preferably, in step S2, the portion to be demolished from a high dam to a low dam is the original dam demolition area, and the demolition height of the dam demolition area is h, which satisfies the following relationship:

[0018] H a -H b >h;

[0019] Where: H a The highest water level in front of the original dam (1) before the construction of the upstream dam (2);

[0020] H b It is the highest water level formed in front of the original dam (1) when the upstream dam (2) is built and operates normally.

[0021] Preferably, after the high dam is converted into a low dam in step S2, the demolition height h satisfies that the water intake elevation of the dam after demolition is between the lowest water level and the highest water level in front of the dam after the transformation.

[0022] Preferably, after the high dam is changed to a low dam in step S2, after the removal height h meets the requirements of adding a new ecological spillway, water bodies with different water temperatures in different layers in front of the dam can be taken to the downstream.

[0023] Preferably, fish attracting facilities are provided in the newly constructed fishway.

[0024] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows:

[0025] (1) Compared with the prior art, the dam renovation and upgrading method provided by the present invention is adapted to the downstream multi-objective ecological flow demand. When a single-stage or multi-stage dam is constructed upstream and downstream of the original dam, and affected by the ecological scheduling of the cascade, the discharge flow or downstream hydrology of the original dam no longer meets the functional requirements of the initial planning and design stage of the dam, but considering the counter-regulatory effect of the original dam on the newly built dams in the upstream and downstream cascades, the dam needs to be rebuilt and its function improved on the basis of considering the economy and not demolishing the dam as a whole, so as to achieve the effect of changing the high weir of the dam to a low weir, building an ecological spillway and improving scheduling flexibility.

[0026] (2) The present invention also takes into account that the transformation of the original dam will affect the normal operation of the existing dam. Without changing the flood control and water supply tasks of the original dam, the present invention provides the structure and upgrading method of the dam in terms of high weir to low weir, ecological sluice gate and sluice water temperature control. In practical applications, it is mainly to adjust and optimize the flow and hydrological needs of multiple ecological targets downstream, so as to fully meet the joint ecological dispatching requirements of the existing counter-regulation dam and the new cascade power station.

[0027] (3) The method provided by the present invention can be used to upgrade the existing dams and gates, which not only helps to improve the ecological environment, but also improves the efficiency and benefits of water resource management, with significant environmental and economic benefits. The design of the high weir of the original dam and gates is changed to a low weir dam and gates, which will enhance the flexibility of scheduling, enable the reservoir management department to respond to different water conditions more efficiently, optimize the use of water resources, and improve flood control and drought resistance capabilities.

[0028] (4) The renovated post-sluice dam can provide more suitable water flow conditions and support water replenishment for the fishway, including replenishing water at the fishway entrance and upstream outlet, promoting the natural migration and reproduction of fish, and restoring and protecting fish resources. By building ecological spillways on one or both sides of the dam shoulders, the downstream water flow can be more accurately controlled to ensure that the ecological flow of the downstream river is maintained. This is crucial to maintaining the health and stability of the river ecosystem. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0030] Figure 1 This is a schematic diagram of the layout of the original dam;

[0031] Figure 2 It is a longitudinal section of the water level elevation of the original dam;

[0032] Figure 3 It is a relative longitudinal section diagram showing the location and water level elevation of the original dam and the newly built upstream dam and downstream dam;

[0033] Figure 4 This is a schematic diagram of the elevation of the original dam removal;

[0034] Figure 5 This is a schematic diagram of the reconstruction of the original dam and the layout of the upstream dam;

[0035] Figure 6 Schematic diagram of the layout of the ecological spillway and fishway to be built on the original dam.

[0036] Explanation of the figure numbers: 1. Original dam; 1a. Dam after demolition; 101. Gate pier; 2. Upstream dam; 201. Downstream dam; 3. Ecological spillway; 301. Fishway; 302. Ecological gate pier; 4. Demolition area of ​​the original dam; h. Demolition elevation. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0039] The original dam 1 was a single-stage power station, but with the planning and construction of the basin base, multi-stage water conservancy and hydropower projects were built upstream and downstream of the original dam 1. Under the obstruction of multiple cascade power stations, the hydrological flow of the existing dam has changed, causing the water level in front of the reservoir of the original dam 1 to change differently. During the construction of the new power station, the original dam 1 needs to cooperate with it to complete the flood control and water supply guarantee work during the construction of the new power station. The new power station has the same flood control and water storage functions as the original dam, but considering safety, the original dam will continue to be retained.

[0040] As shown in the accompanying drawings, in view of the above requirements, this embodiment proposes a dam renovation and upgrading method that adapts to the downstream multi-objective ecological flow requirements, including the following steps:

[0041] S1, build a new upstream dam 2 upstream of the original dam 1, and build a new downstream dam 201 downstream of the original dam 1;

[0042] S2. Reconstruct the original dam 1 from a high dam to a low dam, retaining the water retaining function, to form the post-demolition dam 1a;

[0043] S3, build ecological spillway 3 on one or both sides of the dam abutment after demolition of dam 1a;

[0044] S4. A new fishway 301 is built between the ecological sluice gate 3 and the shore, and the ecological sluice gate 3 is used to maintain normal discharge all year round to replenish water for the newly built fishway 301.

[0045] Combination Figure 1 As shown, under the initial conditions, the original dam 1 was the only dam in the entire river, and before the dam was planned and designed, it was only used as a comprehensive functional body for water storage, water storage or power generation, and the pier 101 of the dam and the matching spillway gate were retained.

[0046] Combination Figure 2 As shown, the highest water level before the original dam 1 is 2100.0m, the dam top elevation of the original dam 1 is 2110.0m, and the downstream water level is 2050.0m.

[0047] Combination Figure 3 As shown in FIG. 1 , an upstream dam 2 and a downstream dam 201 are constructed upstream and downstream of the original dam 1, respectively. Figure 2The water level changes, at this time, the highest water level elevation in front of the original dam 1 is 2100.0m (the flooding elevation of the original dam 1 discharge gate is 1990.0m), and the dam crest elevation of the original dam 1 is guaranteed to be 2110.0m. Therefore, when the upstream dam 2 is built and in normal operation, the discharge gate of the original dam 1 only retains part of the water layer to take water under the movement of the original gate pier 101, so that the water intake of the discharge gate of the original dam 1 only takes a small part of the surface water or The flooding elevation of the spillway gate is still at the existing highest water level elevation of 1990.0m, which leads to the flooding elevation of the original spillway gate being higher than the original dam 1 water level of 1900.0m after the construction of the upstream dam 2, resulting in the flooding water depth of the spillway gate being less than before the construction of the upstream dam 2, which leads to the original dam 1 spillway gate flooding elevation of 1990.0 to be dismantled and arranged below the original dam 1 water level of 1900.0m after the construction of the upstream dam 2. In addition, the flooding water depth of the spillway gate is lower than the water depth before the renovation of the original dam 1, resulting in the water temperature of the water intake of the spillway gate becoming single, which is not conducive to the water temperature of the water body at different water depths when the spillway gate opens different gate openings, thereby affecting the water temperature and life activity requirements of the downstream aquatic organisms. Therefore, it is necessary to change the original dam from a high dam to a low dam.

[0048] The barrier of the original dam 1 to the migratory channel of aquatic organisms (fish) can be divided into a single-layer barrier, and no spillway gates were opened on both sides of the dam shoulders. However, after the construction of the upstream and downstream cascade power stations, that is, the upstream dam 2 and the downstream dam 201 were successively built, from the longitudinal direction of the river, the entire river constituted multiple cascade barriers. Under the obstruction of multiple cascade power stations on the entire river, the upstream and downstream water levels of the original dam 1 changed, and considering the ecological flow requirements between the dams and their upstream and downstream, it is obvious that the discharge of the original dam 1 cannot meet the ecological flow requirements, so it is necessary to rebuild the ecological spillway gate 3 for the demolished dam 1a formed by the high dam being changed into a low dam.

[0049] In this embodiment, in the step S1, during the process of newly building the upstream dam 2 and the downstream dam 201, the original dam 1 always maintains normal water discharge or water storage functions. Furthermore, the original dam 1 is provided with a gate pier 101, and a water discharge gate is provided on the gate pier 101; before the original dam 1 is upgraded, the water discharge gate is required to operate normally on the gate pier 101 and have a long water discharge function. When the high dam is changed to a low dam in the step S2, the original gate pier 101 on the original dam 1 is retained for flood discharge.

[0050] The original dam 1 is being converted from a high dam to a low dam and must meet the following requirements:

[0051] ① When the upstream dam 2 is built and operates normally, the highest water level in front of the original dam 1 is H1, which satisfies that the water intake layer of the original dam 1 is higher than H1. Specifically, in this embodiment, the water intake layer of the original dam 1 is required to be higher than 1900.0m.

[0052] ② The distance between the upstream dam 2 and the original dam 1 is L1, and the distance between the original dam 1 and the downstream dam 201 is L2. In step S2, when the original dam 1 is renovated, it is necessary to meet the requirements that L1 and L2 are not less than the minimum flood control distance, that is, both are not less than 30km.

[0053] When the original dam 1 is converted from a high dam to a low dam, its water retaining function is retained, and only the original height of the dam is reduced to the existing water intake height. Specifically, the part to be demolished when the high dam is converted to a low dam is the original dam demolition area 4. The demolition height of the dam demolition area 4 is h, which satisfies the following relationship:

[0054] H a -H b >h;

[0055] Where: H a H is the highest water level in front of the original dam (1) before the construction of the upstream dam (2); b It is the highest water level formed in front of the original dam (1) when the upstream dam (2) is built and operates normally.

[0056] Furthermore, after the original dam 1 is converted from a high dam to a low dam, the demolition height h satisfies that the water intake elevation of the dam 1a after demolition is between the lowest water level and the highest water level in front of the dam after the transformation.

[0057] In this embodiment, fish attracting facilities are provided in the newly constructed fishway 301, and the fish attracting facilities include but are not limited to sound and light fish attracting devices.

[0058] Combination Figure 5 As shown, after the operation of the upstream dam 2, considering the multi-stage impact of the basin, it is necessary to improve the restoration of the aquatic biological channel and build an aquatic biological channel.

[0059] Since the original dam 1 and the demolished dam 1a formed after the high weir was changed to a low weir do not have this function, it is necessary to build an ecological spillway 3 for the demolished dam 1a in combination with the downstream ecological flow and downstream water temperature requirements. Considering the operation and management of the ecological spillway 3 under the ecological pier 302 of the ecological spillway, it is set up on both sides thereof, and the original dam pier 101 is retained to facilitate flood discharge needs.

[0060] like Figure 3 and Figure 5As shown, considering the influence of water temperature stratification in front of the dam, after the removal height h meets the requirements of adding ecological spillway 3, water bodies with different water temperatures in different stratifications in front of the dam can be taken to the downstream.

[0061] Combination Figure 6 As shown, after the ecological spillway 3 is rebuilt on the shoulders of both sides of the dismantled dam 1a and water from different water temperature stratifications is taken, it can provide the fish entrance of the newly built fishway 301 with water at a water temperature that fish prefer. Moreover, because the ecological spillway 3 is open to discharge water all year round, the water volume and flow rate can also meet the fish attracting conditions of the fish entrance of the newly built fishway 301. Moreover, some fish attracting facilities 3011 are added externally, which can greatly improve the fish passing effect of the newly built fishway 301.

[0062] like Figure 6 As shown, combined with the law of fish clustering under the original dam 1, if the fish clusters are distributed on both sides of the original dam 1, a new aquatic biological migration channel is built on the original dam 1, that is, the fishway 301 is newly built, and the ecological spillway 3 and the ecological pier 302 of the ecological spillway can be arranged on both sides of the demolished dam 1a formed by changing the high dam into a low dam, so that the fish migration on both sides of the demolished dam 1a can be met, and the ecological spillway 3, the pier 302 of the ecological spillway and the newly built fishway 301 on the left and right sides are symmetrically distributed. However, if the ecological spillway 3, the pier 302 of the ecological spillway and the newly built fishway 301 can be arranged on only one side of the demolished dam 1a, it is sufficient to choose to build on one side.

[0063] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A dam renovation and upgrading method to meet the downstream multi-objective ecological flow requirements, It is characterized in that The following steps are involved: S1, constructing a new upstream dam (2) upstream of the original dam (1), and constructing a new downstream dam (201) downstream of the original dam (1); S2. Reconstruct the original dam (1) from a high dam to a low dam, retaining the water retaining function, to form a post-demolition dam (1a); S3, constructing an ecological spillway (3) on one or both sides of the dam abutment after demolition of the dam (1a); S4. A new fishway (301) is built between the ecological sluice gate (3) and the shore, and the ecological sluice gate (3) is used to maintain normal discharge all year round to replenish water for the newly built fishway (301).

2. A method for upgrading a dam and sluice gate adapted to downstream multi-objective ecological flow requirements as claimed in claim 1, It is characterized in that In the step S1, during the process of constructing the upstream dam (2) and the downstream dam (201), the original dam (1) always maintains a normal water discharge or water storage function.

3. A method for upgrading a dam and sluice gate adapted to downstream multi-objective ecological flow requirements as claimed in claim 1, It is characterized in that The original dam (1) is provided with a gate pier (101), and a water discharge gate is provided on the gate pier (101); before the original dam (1) is upgraded and renovated, it is required that the water discharge gate can operate normally on the gate pier (101) and has a long water discharge function.

4. A method for upgrading a dam and sluice gate adapted to downstream multi-objective ecological flow requirements as claimed in claim 3, It is characterized in that When the high dam is changed to a low dam in step S2, the original gate pier (101) on the original dam (1) is retained for flood discharge.

5. A method for upgrading a dam and sluice gate adapted to downstream multi-objective ecological flow requirements as claimed in claim 1, It is characterized in that When the upstream dam (2) is built and operates normally, the highest water level in front of the original dam (1) is H 1 , if the water intake layer of the original dam (1) is higher than H 1 When the original dam (1) is removed and renovated, step S2 needs to be performed.

6. A method for upgrading a dam and sluice gate adapted to downstream multi-objective ecological flow requirements as claimed in claim 1, It is characterized in that The distance between the upstream dam (2) and the original dam (1) is L1, and the distance between the original dam (1) and the downstream dam (201) is L2. In step S2, when the original dam (1) is renovated, it is required that both L1 and L2 are not less than the minimum flood control distance.

7. A method for upgrading a dam and sluice gate adapted to downstream multi-objective ecological flow requirements as claimed in claim 1, It is characterized in that In step S2, the part to be demolished by changing the high dam into the low dam is the original dam demolition area (4), and the demolition height of the dam demolition area (4) is h, which satisfies the following relationship: H a -H b >h; Where: H a The highest water level in front of the original dam (1) before the construction of the upstream dam (2); H b It is the highest water level formed in front of the original dam (1) when the upstream dam (2) is built and operates normally.

8. A method for upgrading a dam and sluice gate adapted to downstream multi-objective ecological flow requirements as claimed in claim 7, It is characterized in that After the high dam is converted into a low dam in step S2, the demolition height h satisfies that the water intake elevation of the demolished dam (1a) is between the lowest water level and the highest water level in front of the modified dam.

9. A method for upgrading a dam and sluice gate adapted to downstream multi-objective ecological flow requirements as claimed in claim 7, It is characterized in that After the high dam is changed to a low dam in step S2, the removal height h meets the requirement of the newly added ecological spillway (3), and water bodies with different water temperatures in different layers in front of the dam can be taken to the downstream.

10. A method for upgrading a dam and sluice gate adapted to downstream multi-objective ecological flow requirements as claimed in claim 1, It is characterized in that The newly constructed fishway (301) is provided with fish attracting facilities.

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