Shaft spillway energy dissipation structure

Abstract

The utility model provides a shaft spillway energy dissipation structure which comprises a stilling pool and a stilling beam, the head portion of the stilling pool is arranged below a shaft, the tail portion of the stilling pool is connected with a recession tunnel, the bottom of the stilling pool is flush with the bottom of the recession tunnel, the height of the stilling pool is larger than that of the recession tunnel, and the stilling beam is connected with the stilling pool. Water flows into the recession tunnel through the vertical shaft and the stilling pool in sequence, the stilling beam is arranged in the middle of the stilling pool, and the extending direction of the stilling beam is perpendicular to the main flow direction in the stilling pool. The flat-bottom stilling pool and the stilling beams are arranged at the bottom of an existing vertical shaft, a common cylindrical stilling well is replaced, the energy dissipation effect can be enhanced, the pulsating load of a bottom plate of the stilling pool and the fluctuation of the water surface in the pool are reduced, and the stilling structure has the advantages of being safe in structure, smooth in outflow and the like.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of water conservancy and hydropower engineering, especially relates to a vertical shaft spillway energy dissipation structure. BACKGROUND

[0002] Pumped storage power stations have gradually become an important support for China's energy structure transformation, the construction of a new power system, and the realization of the "double carbon" goal due to their unique role in peak shaving, emergency backup, frequency and phase modulation, and significant economic and ecological environmental benefits. A pumped storage power station is mainly composed of two reservoirs at different altitudes and the pumping and power generation system between them. The flood flow of the upper and lower reservoirs is generally not large, and artificial lake landscapes are usually formed by reservoir storage, so large-scale excavation of spillways on the shore is not generally used, and a vertical shaft is excavated and connected to the diversion tunnel during construction to form a vertical shaft spillway as a discharge structure during operation.

[0003] Vertical shaft spillways have the advantages of simple structure, small environmental disturbance, and small engineering investment, and are mainly composed of a ring-shaped overflow weir, a vertical shaft, an energy dissipation well, a non-pressure drainage tunnel, and outlet energy dissipation facilities, etc. In a vertical shaft spillway, water flows downward along the vertical direction after passing through the ring-shaped weir, and the gravitational potential energy is quickly converted into kinetic energy. Under the action of a 50-100m drop, the flow velocity of the water reaching the bottom of the well can reach 20-30m / s. The high-speed water flow collides with the structure at the bottom of the vertical shaft, and the water and air are strongly mixed and turbulent. To ensure the safety of the vertical shaft, the structure at the bottom of the vertical shaft needs to be properly designed to dissipate the kinetic energy of the water flow through its own aeration and turbulence, ensure that the water flow pulsation load on the surface of the flow structure is within a safe range, and quickly adjust the flow direction so that the water flows smoothly through the short horizontal drainage tunnel (i.e. the diversion tunnel during construction).

[0004] In engineering practice, the energy dissipation well is further excavated along the vertical shaft axis based on the elevation of the drainage tunnel bottom plate to form an energy dissipation well with the same diameter as the vertical shaft to increase the water volume in the bottom energy dissipation area and improve the energy dissipation effect. The above-mentioned energy dissipation method can solve the energy dissipation problem of most vertical shaft spillways. However, in recent years, with the continuous breakthrough of the vertical shaft discharge flow, and considering the limitation of the excavation depth of the energy dissipation well due to geological conditions, the energy dissipation well cannot meet the energy dissipation needs of some vertical shafts, resulting in violent vibration of the energy dissipation well and strong water flow fluctuation in the drainage tunnel, which even left and right, up and down, and floating, threatening the safe operation of the vertical shaft spillway. INVENTION CONTENTS

[0005] The utility model discloses a vertical shaft spillway energy dissipation structure which is characterized by the following technical scheme: a flat-bottomed energy dissipation pool is arranged at the bottom of the existing vertical shaft to enhance the energy dissipation effect and reduce the fluctuating load on the bottom plate of the stilling pool and the water surface fluctuation in the pool.

[0006] To solve the above technical problems, the utility model adopts the technical scheme of:

[0007] A vertical shaft spillway energy dissipation structure comprises:

[0008] The first end of the stilling pool is arranged below the vertical shaft and connected with the tail end of the water release tunnel, the bottom of the stilling pool is flush with the bottom of the water release tunnel, the height of the stilling pool is greater than the height of the water release tunnel, and water flows into the water release tunnel through the vertical shaft and the stilling pool in sequence.

[0009] The energy dissipation beam is arranged in the middle of the stilling pool, and the extension direction of the energy dissipation beam is perpendicular to the main flow direction in the stilling pool.

[0010] Further, the cross section of the stilling pool is rectangular.

[0011] Further, the width of the stilling pool is not less than the diameter of the vertical shaft.

[0012] Further, the length of the stilling pool is 3-5 times the diameter of the vertical shaft.

[0013] Further, the length of the stilling pool upstream of the energy dissipation beam is 1.5-3 times the diameter of the vertical shaft, and the length of the stilling pool downstream of the energy dissipation beam is 1-2 times the diameter of the vertical shaft.

[0014] Further, the ratio of the height of the energy dissipation beam to the diameter of the vertical shaft is 0.3-0.6.

[0015] Further, the thickness of the energy dissipation beam is 0.5-1 m.

[0016] Further, the height of the stilling pool is 1.5-2 times the height of the water release tunnel.

[0017] Further, the ratio of the height difference between the bottom of the energy dissipation beam and the bottom of the stilling pool to the diameter of the vertical shaft is 0.15-0.25.

[0018] Further, the connection parts of the stilling pool with the vertical shaft and the water release tunnel are chamfered.

[0019] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0020] (1) Good energy dissipation effect: the energy dissipation structure properly enlarges the connection section of the vertical shaft and the outfall tunnel by setting the stilling basin, and the stilling beam can raise the water level in the basin, thereby significantly increasing the water volume in the energy dissipation area and enhancing the energy dissipation effect.

[0021] (2) Good flow pattern of the outfall tunnel: the stilling beam in the energy dissipation structure is located near the water surface, which can effectively eliminate or reduce water surface fluctuation, so that the water flow entering the outfall tunnel is more stable.

[0022] (3) Low safety risk of the stilling basin structure: the stilling beam can raise the water level in the basin, increase the water depth, and reduce the pulsating pressure of the bottom plate of the stilling basin, thereby reducing the safety risk of the stilling basin structure.

[0023] (4) Good adaptability to geological conditions: the energy dissipation structure does not need to continue to dig under the bottom plate elevation of the outfall tunnel, and can adapt to complex geological conditions. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings, which are included to provide a further understanding of the present application and constitute a part of this application, illustrate certain non-limiting embodiments of the present application. The illustrative embodiments of the present application and their description serve to explain the present application. In the drawings:

[0025] Figure 1 is a front view of the energy dissipation structure.

[0026] Figure 2 is Figure 1 is a top view of the a-a section.

[0027] In the drawings, 1 is a stilling basin, 2 is a stilling beam, 3 is an inlet ring weir, 4 is a vertical shaft, 5 is an outfall tunnel, 6 is water flow, 61 is a water surface, 7 is a gas bubble, 11 is the corner of the top plate at the connection of the stilling basin and the vertical shaft, and 12 is the corner of the top plate at the connection of the stilling basin and the outfall tunnel. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application.

[0029] In the description of the utility model, it is understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model. In addition, the terms "first", "second" and the like are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the utility model, the meaning of "a plurality of" is two or more, unless otherwise specified.

[0030] The embodiment provides a vertical shaft spillway energy dissipation structure, which comprises: Figure 1 and Figure 2 as shown, comprising:

[0031] The stilling basin 1 is arranged below the vertical shaft 4 and connected with the tail part and the water retreat tunnel 5, the bottom of the stilling basin 1 is flush with the bottom of the water retreat tunnel 5, the height of the stilling basin 1 is greater than the height of the water retreat tunnel 5, water flows into the water retreat tunnel 5 through the vertical shaft 4 and the stilling basin 1 in turn, and a large number of bubbles 7 are generated in the energy dissipation process.

[0032] The stilling beam 2 is arranged in the middle part of the stilling basin 1, and the extension direction of the stilling beam 2 is perpendicular to the main flow direction in the stilling basin 1.

[0033] The vertical shaft spillway energy dissipation structure provided by the embodiment increases the stilling basin 1 and the stilling beam 2 relative to the existing vertical shaft spillway energy dissipation structure, and has the following advantages through the combination of "stilling basin 1 + stilling beam 2":

[0034] (1) Good energy dissipation effect: the energy dissipation structure appropriately enlarges the connecting section of the vertical shaft 4 and the water retreat tunnel 5 through the stilling basin 1, and the stilling beam 2 can raise the water level in the pool, thereby significantly increasing the water volume of the energy dissipation zone and enhancing the energy dissipation effect.

[0035] (2) Good flow state of the water retreat tunnel 5: the stilling beam 2 arranged in the energy dissipation structure is located near the water surface 61, can effectively eliminate or reduce the fluctuation of the water surface 61, and makes the water flow 6 entering the water retreat tunnel 5 more stable.

[0036] (3) Low structural safety risk of the stilling basin 1: the stilling beam 2 can raise the water level in the pool, increase the water depth, reduce the pulsating pressure of the bottom plate of the stilling basin 1, and thereby reduce the structural safety risk of the stilling basin 1.

[0037] (4) Good adaptability to geological conditions: the energy dissipation structure does not need to be further excavated on the basis of the bottom elevation of the tailrace tunnel 5, and can adapt to complex geological conditions.

[0038] In this embodiment, as shown in Figure 2 , the cross section of the stilling basin 1 is rectangular, the extension direction of the stilling beam 2 is perpendicular to the main flow direction in the stilling basin 1, and the stilling beam 2 is perpendicular to the side wall of the stilling basin 1.

[0039] In this embodiment, as shown in Figure 1 , the width b of the stilling basin 1 is not less than the diameter D of the shaft 4, so as to avoid the impact of the falling water flow 6 on the side wall and the bottom of the stilling basin 1 and ensure sufficient transverse energy dissipation space; the length of the stilling basin 1 is generally 3-5 times the diameter of the shaft 4, so as to ensure sufficient water volume in the stilling basin 1, and then the average energy dissipation intensity of unit volume of water body meets the structural vibration safety requirement, and the length direction of the stilling basin 1 is the main flow direction in the stilling basin 1.

[0040] In this embodiment, as shown in Figure 1 and Figure 2 , the horizontal length l1 of the stilling basin 1 upstream of the stilling beam 2 is 1.5-3 times the diameter D of the shaft 4, so that most of the kinetic energy of the water flow 6 upstream of the stilling beam 2 can be consumed, and at the same time the structural safety of the stilling beam 2 under the action of the strong pulsating water flow 6 is ensured; the length l2 of the stilling basin 1 downstream of the stilling beam 2 is 1-2 times the diameter D of the shaft 4, so that the water flow 6 after surface wave dissipation can be adjusted smoothly before entering the tailrace tunnel 5.

[0041] In this embodiment, as shown in Figure 1 , the height h b of the stilling beam 2 is 0.3-0.6 times the diameter D of the shaft 4, which can achieve better wave dissipation and energy dissipation effect while avoiding affecting the overflow capacity of the shaft spillway.

[0042] In this embodiment, as shown in Figure 2 , the thickness l b of the stilling beam 2 is 0.5-1m, so as to ensure the stability of its own structure and meet the construction requirements.

[0043] In this embodiment, as shown in Figure 1 , the height H of the stilling basin 1 is 1.5-2 times the height h t of the tailrace tunnel 5, so as to ensure that the water surface 61 fluctuation and splashing do not seal the top.

[0044] In this embodiment, the height difference h fThe ratio of the diameter D of the vertical shaft 4 to the diameter of the vertical shaft 4 is 0.15 to 0.25, usually 0.2, and ensures that there is pressurized outflow below it, so as to reduce the pulsating pressure of the bottom plate of the stilling basin 1, and at the same time make the mainstream direction of the water flow 6 flowing downstream along the bottom of the stilling beam 2 more concentrated, faster and smoother.

[0045] In this embodiment, preferably, as follows: Figure 1 As shown, the connection between stilling basin 1 and shaft 4, as well as the connection between stilling basin 1 and drainage tunnel 5, has rounded corners. The corners of the top plate at the connection between stilling basin 1 and shaft 4, as well as the connection between stilling basin 1 and drainage tunnel 5, can be rounded to make the flow of water 6 under the condition of exceeding the design flow rate smoother.

[0046] In this embodiment, as Figure 1 As shown, the top of the shaft 4 is also equipped with an inlet annular weir 3, which is used to introduce water flow 6 into the shaft 4.

[0047] In one specific implementation of this embodiment, such as Figure 1 and Figure 2 As shown, a certain vertical shaft spillway consists of an inlet annular weir 3, a vertical shaft 4, a stilling basin 1, and a drainage tunnel 5. A stilling beam 2 is arranged inside the stilling basin 1. The diameter of the vertical shaft 4 is 6m, and the drainage tunnel 5 is 6m wide and 7m high.

[0048] The stilling basin 1 and the stilling beam 2 form a cost-effective energy dissipation structure, located at the junction of the shaft 4 and the drainage tunnel 5. The stilling basin 1 is located at the bottom of the shaft 4, and its tail is connected to the drainage tunnel 5. The stilling beam 2 is located in the middle of the stilling basin 1 in both the horizontal and vertical directions and is fixed to the side wall of the stilling basin 1.

[0049] The width b of stilling basin 1 is 6m, which is not less than the diameter D (6m) of shaft 4, and the length L = 24m, which is 4 times the diameter D of shaft 4.

[0050] The horizontal length l1 from the head of stilling basin 1 to the upstream face of stilling beam 2 is 12m, which is twice the diameter D of shaft 4 (6m). The length l2 from the downstream face of stilling beam 2 to the inlet of drainage tunnel 5 is 10m, which is 1.67 times the diameter of shaft 4.

[0051] The height h of the stilling beam 2 b =3m, the ratio of which to the diameter D=6m of shaft 4 is 0.5, and the length l along the flow direction of the stilling beam 2 is... b =0.6m, which meets the requirements for structural stability.

[0052] The total height of stilling basin 1, H = 12m, is the height h of drainage tunnel 5. t = 1.71 times 7m, the height difference h between the bottom surface of the stilling beam 2 and the bottom plate f =1.2m, and the ratio of the diameter D=6m of shaft 4 is 0.2, with pressurized outflow below it.

[0053] The corner 11 of the top plate of the junction of the stilling basin and the shaft and the corner 12 of the top plate of the junction of the stilling basin and the drainage tunnel are rounded to make the flow of the water flow 6 more smooth under the condition of the super design flow.

[0054] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application also intends to include these modifications and variations.

Claims

1. A shaft spillway energy dissipation structure, characterized by, The application relates to a vertical shaft spillway energy dissipation structure. The application relates to a vertical shaft spillway energy dissipation structure.

2. The vertical shaft spillway energy dissipation structure according to claim 1, wherein the cross section of the stilling basin is rectangular.

3. The vertical shaft spillway energy dissipation structure according to claim 1, wherein the width of the stilling basin is not less than the diameter of the vertical shaft.

4. The vertical shaft spillway energy dissipation structure according to claim 3, wherein the length of the stilling basin is 3-5 times the diameter of the vertical shaft.

5. The vertical shaft spillway energy dissipation structure according to claim 1, wherein the length of the stilling basin upstream of the stilling beam is 1.5-3 times the diameter of the vertical shaft, and the length of the stilling basin downstream of the stilling beam is 1-2 times the diameter of the vertical shaft.

6. The vertical shaft spillway energy dissipation structure according to claim 1, wherein the ratio of the height of the stilling beam to the diameter of the vertical shaft is 0.3-0.

6.

7. The vertical shaft spillway energy dissipation structure according to claim 1, wherein the thickness of the stilling beam is 0.5-1 m.

8. The vertical shaft spillway energy dissipation structure according to claim 1, wherein the height of the stilling basin is 1.5-2 times the height of the outflow tunnel.

9. The vertical shaft spillway energy dissipation structure according to claim 1, wherein the ratio of the height difference between the bottom of the stilling beam and the bottom of the stilling basin to the diameter of the vertical shaft is 0.15-0.

25.

10. The vertical shaft spillway energy dissipation structure according to claim 1, wherein the junctions of the stilling basin with the vertical shaft and the outflow tunnel are chamfered. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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