Anti-corrosion energy dissipation ring structure of vertical shaft rotational flow flood discharge tunnel

Abstract

The invention discloses an anti-corrosion energy dissipation ring structure of a vertical shaft rotational flow flood discharge tunnel, and relates to the technical field of water conservancy and hydropower engineering. Comprising an inlet section, a volute chamber, a vertical shaft and a recession tunnel. The volute chamber and the vertical shaft are vertically arranged, the volute chamber communicates with the upper portion of the vertical shaft, the inlet section and the recession tunnel are horizontally arranged, the inlet section communicates with the volute chamber, and the recession tunnel communicates with the vertical shaft; at least one anti-corrosion energy dissipation ring is arranged in the vertical shaft, the anti-corrosion energy dissipation ring is of an annular pipeline structure coaxial with the vertical shaft, the anti-corrosion energy dissipation ring abuts against the inner wall of the vertical shaft, at least two slotted holes are formed in the anti-corrosion energy dissipation ring, and the slotted holes are formed in the circumferential direction of the anti-corrosion energy dissipation ring at equal intervals. The slotted holes are formed in the thickness direction of the anti-corrosion energy dissipation ring in a penetrating mode. The anti-corrosion energy dissipation ring is used for blocking water flow in the vertical shaft so as to change the flow direction of the water flow near the side wall of the vertical shaft, the water flow is forced to flow towards the middle of the anti-corrosion energy dissipation ring, and therefore the dynamic water pressure of the side wall of the vertical shaft can be increased, and the risk of cavitation and cavitation erosion of the side wall of the vertical shaft is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of water conservancy and hydropower engineering, and in particular to an erosion-resistant energy-dissipating ring structure for a shaft swirl flood discharge tunnel. Background Art

[0002] In water conservancy and hydropower engineering, the flood discharge and energy dissipation system is related to the safety of the project operation. The flood discharge and energy dissipation system discharges the excess water in the hydropower station reservoir in a short time through flood discharge, and reduces the potential energy brought by the water level difference between the upstream and downstream through the energy dissipator when discharging the excess water. In actual projects, the reasonable layout of the shore buildings is usually achieved by setting up an internal energy dissipation flood discharge tunnel, and the adverse effects such as cavitation damage, energy dissipation and erosion prevention, and atomization are reduced. The internal energy dissipation flood discharge tunnel is mainly divided into a shaft swirl flood discharge tunnel, a shaft drop flood discharge tunnel, a horizontal tunnel swirl flood discharge tunnel, an orifice flood discharge tunnel, and a tunnel plug flood discharge tunnel according to the layout characteristics and flow pattern characteristics.

[0003] The shaft swirl flood discharge tunnel generally includes buildings such as an inlet section, a vortex chamber, a shaft, a water withdrawal tunnel, and an outlet section; the shaft of the shaft swirl flood discharge tunnel is relatively high, and the shaft height of a large shaft swirl flood discharge tunnel generally reaches the order of 100 meters. The water flow velocity in the shaft can be as high as 30 - 50 m / s. The ultra-high water flow velocity may cause a sudden drop in the pressure on the side wall of the shaft, and even a negative pressure situation, which is likely to cause serious cavitation damage to the side wall of the shaft and pose a safety hazard. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an erosion-resistant energy-dissipating ring structure for a shaft swirl flood discharge tunnel, which can avoid cavitation damage to the side wall of the shaft while ensuring the flow rate in the shaft.

[0005] The technical solution adopted by the present invention to solve the above technical problem is: an erosion-resistant energy-dissipating ring structure for a shaft swirl flood discharge tunnel, including an inlet section, a vortex chamber, a shaft, and a water withdrawal tunnel; the vortex chamber and the shaft are vertically arranged and the vortex chamber is connected to the upper part of the shaft. The inlet section and the water withdrawal tunnel are horizontally arranged. The inlet section is connected to the vortex chamber, and the water withdrawal tunnel is connected to the shaft; at least one erosion-resistant energy-dissipating ring is arranged in the shaft. The erosion-resistant energy-dissipating ring is a ring-shaped pipeline structure coaxial with the shaft, and the erosion-resistant energy-dissipating ring is in contact with the inner wall of the shaft. At least two slotted holes are provided on the erosion-resistant energy-dissipating ring, and the slotted holes are equidistantly arranged at intervals in the circumferential direction of the erosion-resistant energy-dissipating ring, and the slotted holes penetrate through in the thickness direction of the erosion-resistant energy-dissipating ring.

[0006] As an improvement of the above solution: the radial cross-sections of the vortex chamber and the shaft are both circular, and the vortex chamber and the shaft are coaxially arranged; the diameter of the vortex chamber is 1.2 - 1.6 times the diameter of the shaft.

[0007] As an improvement to the above solution: A conical transition section is provided between the vortex chamber and the shaft. The contraction angle of the conical transition section is not greater than 11.5°, and the length of the conical transition section is at least greater than 1 times the diameter of the shaft.

[0008] As an improvement to the above solution: The width of the erosion-resistant energy-dissipating ring is less than 1 / 8 of the diameter of the shaft, and the thickness of the erosion-resistant energy-dissipating ring is less than 1 / 10 of the diameter of the shaft.

[0009] As an improvement to the above solution: The number of the erosion-resistant energy-dissipating rings provided is multiple, and the multiple erosion-resistant energy-dissipating rings are arranged at equal intervals along the axial direction of the shaft in the middle and lower parts of the shaft.

[0010] As an improvement to the above solution: The slotted holes are arc-shaped holes, and the total arc length of the slotted holes is greater than 1 / 10 of the circumference of the shaft and less than 1 / 2 of the circumference of the shaft.

[0011] As an improvement to the above solution: The inlet section and the vortex chamber are tangentially connected in a way of linear tangency or arc tangency.

[0012] As an improvement to the above solution: The shaft and the drainage tunnel are connected by a top pressing plate, and one end of the top pressing plate close to the shaft has a slope of 1:6 to 1:10.

[0013] The beneficial effects of the present invention are as follows: By improving the shaft structure of the shaft swirl flood discharge tunnel of the present invention, an erosion-resistant energy-dissipating ring with slotted holes is arranged inside the shaft. The erosion-resistant energy-dissipating ring is used to block the water flow in the shaft to change the water flow direction near the side wall of the shaft, forcing the water flow near the side wall of the shaft to flow towards the middle of the erosion-resistant energy-dissipating ring and converge into the central area of the shaft, so as to increase the dynamic water pressure on the side wall of the shaft and reduce the risk of cavitation erosion on the side wall of the shaft; at the same time, the slotted holes provided on the erosion-resistant energy-dissipating ring can shunt and guide the water flow, enabling part of the water flow to disperse and flow downward, sharing the water flow rate at the central part of the erosion-resistant energy-dissipating ring, ensuring smooth water flow through the shaft, and thus being able to ensure that the water flow rate through the shaft remains unchanged as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is the structural axonometric drawing of the present invention; Figure 2 is the longitudinal sectional schematic diagram of the present invention; Figure 3 is the structural axonometric drawing of the erosion-resistant energy-dissipating ring in the present invention; Figure 4 is the water flow pattern diagram without the erosion-resistant energy-dissipating ring; Figure 5 is the water flow velocity contour diagram in the shaft without the erosion-resistant energy-dissipating ring; Figure 6 is the water flow pattern diagram when the present invention is adopted; Figure 7 The flow velocity contour map of the water flow in the vertical shaft when the present invention is adopted; The markings in the figure are: 100 - inlet section, 200 - vortex chamber, 300 - vertical shaft, 400 - outlet tunnel, 500 - erosion - resistant energy - dissipating ring, 510 - slotted hole, 600 - conical transition section, 700 - top pressing plate. Specific embodiments

[0015] For the convenience of understanding the present invention, the present invention will be further described below with reference to the accompanying drawings.

[0016] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "front", "rear", "left", "right", "upper", "lower", "inner", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the present invention.

[0017] As Figure 1 and Figure 2 shown, a structure of an erosion - resistant energy - dissipating ring for a vertical - shaft swirl flood - discharge tunnel disclosed by the present invention is composed of an inlet section 100, a vortex chamber 200, a vertical shaft 300 and an outlet tunnel 400. The vortex chamber 200 is communicated with the vertical shaft 300. Both the vortex chamber 200 and the vertical shaft 300 are vertically arranged, and the vortex chamber 200 is communicated with the upper part of the vertical shaft 300; the inlet section 100 is horizontally arranged and communicated with the upstream of the vortex chamber 200, and the outlet tunnel 400 is horizontally arranged and communicated with the downstream of the vertical shaft 300. In order to avoid the occurrence of cavitation damage on the side wall of the vertical shaft 300, an erosion - resistant energy - dissipating ring 500 is arranged inside the vertical shaft 300. The erosion - resistant energy - dissipating ring 500 blocks and diverts the water flow in the vertical shaft 300, so that the water flow at the side wall of the vertical shaft 300 leaves the side wall of the vertical shaft 300 and flows towards the center of the erosion - resistant energy - dissipating ring 500 and the central area of the vertical shaft 300. Part of the water flow is diverted through the slotted holes 510 on the erosion - resistant energy - dissipating ring 500, so that the water flow in the vertical shaft 300 is diverted and flows through the central area of the erosion - resistant energy - dissipating ring 500 and the slotted holes 510 on the erosion - resistant energy - dissipating ring 500. Thus, while ensuring the flow rate, the dynamic water pressure at the side wall of the vertical shaft 300 is increased. Subsequently, the diverted water flow drops and collides to dissipate energy at the bottom of the vertical shaft 300, and finally surges into the outlet tunnel 400 and flows out to the outlet section.

[0018] Specifically, as Figure 3As shown, the erosion-resistant energy dissipation ring 500 adopted in the present invention has an annular structure. The erosion-resistant energy dissipation ring 500 is coaxially arranged with the shaft 300 so that the erosion-resistant energy dissipation ring 500 can be parallel to the cross-section of the shaft 300, and the erosion-resistant energy dissipation ring 500 is in contact with the inner wall surface of the shaft 300. The number of erosion-resistant energy dissipation rings 500 can be set to multiple according to the requirements for the energy dissipation effect. When multiple erosion-resistant energy dissipation rings 500 are used, the multiple erosion-resistant energy dissipation rings 500 are arranged at equal intervals in the axial direction of the shaft 300, and the erosion-resistant energy dissipation ring 500 is arranged in the middle and lower part of the shaft 300. Slot holes 510 are provided on the erosion-resistant energy dissipation ring 500, and the number of slot holes 510 is set to at least two. The slot holes 510 are arranged at equal intervals along the circumferential direction of the erosion-resistant energy dissipation ring 500, and the slot holes 510 penetrate the erosion-resistant energy dissipation ring 500 in the thickness direction of the erosion-resistant energy dissipation ring 500.

[0019] Furthermore, the erosion-resistant energy dissipation ring 500 adopted in the present invention has a multi-material composite structure. A layer of polyurethane gel material is provided on the surface of the erosion-resistant energy dissipation ring 500, and the inside of the erosion-resistant energy dissipation ring 500 is made of a high-strength material, which can effectively reduce the damage of cavitation to the erosion-resistant energy dissipation ring 500 itself.

[0020] Furthermore, as Figure 1 and Figure 2 shown, both the volute chamber 200 and the shaft 300 in the present invention are cylindrical channels, that is, the radial cross-sectional shapes of the volute chamber 200 and the shaft 300 are both circular, and the volute chamber 200 is coaxially arranged with the shaft 300; in order to enable the diverted water flow to obtain a better drop energy dissipation effect in the shaft 300, it is defined that the diameter of the shaft 300 is smaller than the diameter of the volute chamber 200, and the specific defined range is that the diameter of the volute chamber 200 is 1.2 - 1.6 times the diameter of the shaft 300. And due to the diameter difference between the volute chamber 200 and the shaft 300, it is preferably to set a transition section at the junction of the volute chamber 200 and the shaft 300 to ensure that the water flow can smoothly flow from the volute chamber 200 into the shaft 300. As Figure 1 and Figure 2 shown, the present invention provides a conical transition section 600 at the junction between the volute chamber 200 and the shaft 300. The large end of the conical transition section 600 is connected to the volute chamber 200, and the small end of the conical transition section 600 is connected to the shaft 300; and it is defined that the contraction angle of the conical transition section 600 is not greater than 11.5°, and the length of the conical transition section 600 is at least greater than 1 time the diameter of the shaft 300.

[0021] Furthermore, the width of the erosion-resistant energy dissipation ring 500 in the present invention is less than 1 / 8 of the diameter of the shaft 300, and the thickness of the erosion-resistant energy dissipation ring 500 is less than 1 / 10 of the diameter of the shaft 300. The slot hole 510 is an arc-shaped hole, and the total arc length of the slot holes 510 is greater than 1 / 10 of the circumference of the shaft 300 and less than 1 / 2 of the circumference of the shaft 300.

[0022] Further, in order to make the transition between the inlet section 100 and the volute chamber 200 smoother, the inlet section 100 and the volute chamber 200 are tangentially connected by a straight line or an arc, that is, the side walls of the inlet section 100 and the volute chamber 200 are connected by a tangent line.

[0023] Further, as Figure 1 and Figure 2 shown, a top pressing plate 700 is provided between the vertical shaft 300 and the water discharging tunnel 400 of the present invention, so that the vertical shaft 300 and the water discharging tunnel 400 are connected through the top pressing plate 700, and one end of the top pressing plate 700 close to the vertical shaft 300 has a slope of 1:6 to 1:10.

[0024] Embodiment: In this embodiment, the diameter of the volute chamber 200 is set to 1.4 times the diameter of the vertical shaft 300, the contraction angle of the conical transition section 600 provided between the volute chamber 200 and the vertical shaft 300 is set to 11.5°, and the length of the conical transition section 600 is 1 time the diameter of the vertical shaft 300; an erosion-resistant energy dissipation ring 500 is provided in the vertical shaft 300, 4 slotted holes 510 are provided on the erosion-resistant energy dissipation ring 500, the arc length of the slotted holes 510 is 1 / 20 of the circumference of the vertical shaft 300, the thickness of the erosion-resistant energy dissipation ring 500 is 1 / 12 of the diameter of the vertical shaft 300, and the width of the erosion-resistant energy dissipation ring 500 is 1 / 10 of the diameter of the volute chamber 200.

[0025] The RNG k-ε turbulence model and the finite volume discretization method are used for hydraulic numerical simulation, and the flow pattern diagram of the water flow without the erosion-resistant energy dissipation ring as shown in Figure 4 and the water flow velocity contour diagram of the water flow without the erosion-resistant energy dissipation ring as shown in Figure 5 are obtained. The flow pattern diagram of the water flow corresponding to the above embodiment of the erosion-resistant energy dissipation ring structure of the vertical shaft swirl flood discharge tunnel of the present invention as shown in Figure 6 and the water flow velocity contour diagram corresponding to the above embodiment of the erosion-resistant energy dissipation ring structure of the vertical shaft swirl flood discharge tunnel of the present invention as shown in Figure 7 are obtained. Comparing the comparative examples of Figure 4 and Figure 5 , and referring to the embodiment of Figure 6 Figure 7 , it can be seen that after adopting the structure of the present invention, the swirl flow pattern in the vertical shaft will not be affected, and the water flow velocity in the vertical shaft is reduced from 35.1 m / s to 31 m / s. Since the risk of cavitation is proportional to the square of the water flow velocity, after adding the erosion-resistant energy dissipation ring, the cavitation risk is significantly reduced.

Claims

1. An anti-corrosion and energy-dissipating ring structure for a vertical shaft swirl flood discharge tunnel, characterized in that: It includes an inlet section (100), a volute chamber (200), a shaft (300) and a water discharge tunnel (400); the volute chamber (200) and the shaft (300) are vertically arranged, and the volute chamber (200) communicates with the upper part of the shaft (300). The inlet section (100) and the water discharge tunnel (400) are horizontally arranged. The inlet section (100) communicates with the volute chamber (200), and the water discharge tunnel (400) communicates with the shaft (300); at least one erosion-resistant energy dissipation ring (500) is arranged in the shaft (300). The erosion-resistant energy dissipation ring (500) is an annular pipe structure coaxial with the shaft (300). The erosion-resistant energy dissipation ring (500) is in contact with the inner wall of the shaft (300). At least two slotted holes (510) are provided on the erosion-resistant energy dissipation ring (500). The slotted holes (510) are equidistantly arranged at intervals in the circumferential direction of the erosion-resistant energy dissipation ring (500), and the slotted holes (510) penetrate through in the thickness direction of the erosion-resistant energy dissipation ring (500).

2. The erosion-resistant energy-dissipating ring structure of a vertical shaft swirl flood discharge tunnel according to claim 1, characterized in that: The radial cross-sections of the volute chamber (200) and the shaft (300) are both circular, and the volute chamber (200) and the shaft (300) are coaxially arranged; the diameter of the volute chamber (200) is 1.2 to 1.6 times the diameter of the shaft (300).

3. The erosion-resistant energy-dissipating ring structure of a vertical shaft swirl flood discharge tunnel according to claim 1, characterized in that: A conical transition section (600) is provided between the volute chamber (200) and the shaft (300). The contraction angle of the conical transition section (600) is not greater than 11.5°, and the length of the conical transition section (600) is at least greater than 1 times the diameter of the shaft (300).

4. The erosion-resistant energy dissipation ring structure of a vertical shaft swirl flood discharge tunnel according to claim 1, characterized in that: The width of the erosion-resistant energy dissipation ring (500) is less than 1 / 8 of the diameter of the shaft (300), and the thickness of the erosion-resistant energy dissipation ring (500) is less than 1 / 10 of the diameter of the shaft (300).

5. The erosion-resistant energy dissipation ring structure of a vertical shaft swirl flood discharge tunnel according to claim 1, characterized in that: The number of the erosion-resistant energy dissipation rings (500) provided is multiple. The multiple erosion-resistant energy dissipation rings (500) are equidistantly arranged along the axial direction of the shaft (300) in the middle and lower parts of the shaft (300).

6. The erosion-resistant energy-dissipating ring structure of a vertical shaft swirl flood discharge tunnel according to claim 1, characterized in that: The slotted holes (510) are arc-shaped holes, and the total arc length of the slotted holes (510) is greater than 1 / 10 of the circumference of the shaft (300) and less than 1 / 2 of the circumference of the shaft (300).

7. The erosion-resistant energy-dissipating ring structure of a vertical shaft swirl flood discharge tunnel according to claim 1, characterized in that: The inlet section (100) and the volute chamber (200) are tangentially connected in a way of straight line tangency or arc tangency.

8. The erosion-resistant energy dissipation ring structure of a vertical shaft swirl flood discharge tunnel according to claim 1, characterized in that: The shaft (300) and the water discharge tunnel (400) are connected by a top pressing plate (700). One end of the top pressing plate (700) close to the shaft (300) has a slope of 1:6 to 1:10.

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