Structure and method for solving backwater problem of shaft cyclone chamber inlet

Abstract

The application discloses a structure for solving the backwater problem of the inlet of a vertical shaft vortex chamber, comprising a vortex chamber, a vortex chamber connecting section connected upstream of the vortex chamber, an upper tunnel section connected upstream of the vortex chamber connecting section, a vertical shaft connected to the bottom outlet of the vortex chamber, a stilling well connected to the bottom outlet of the vertical shaft, a flood discharge through hole formed in the side of the stilling well, a vertical shaft connecting section connected to the side of the stilling well at the flood discharge through hole, and a backwater tunnel connected to the outlet end of the vertical shaft connecting section. The application also discloses a method for solving the backwater problem of the inlet of a vertical shaft vortex chamber. The structure and method for solving the backwater problem of the inlet of a vertical shaft vortex chamber disclosed by the application solve the problem of water blockage caused by backwater at the inlet of a traditional vertical shaft vortex chamber.

Description

Technical Field

[0001] This invention belongs to the technical field of vertical shaft vortex discharge tunnels, specifically relating to a structure for solving the problem of backflow at the inlet of a vertical shaft vortex chamber, and also relating to a method for solving the problem of backflow at the inlet of a vertical shaft vortex chamber. Background Technology

[0002] Vertical shaft vortex spillway tunnels typically consist of an upper horizontal tunnel section, a vortex chamber, a vertical shaft, a connecting section, and a drainage tunnel section. The vortex chamber is a crucial component for controlling flow and ensuring shaft safety. The structure at the vortex chamber inlet is usually modified, such as by adding a baffle on the inner sidewall to guarantee safe operation. However, with increasing discharge and head, the flow pattern in the vortex chamber becomes more complex, potentially leading to backflow, backwater, and wall overflow, directly impacting structural safety and efficiency. Traditional designs typically feature a gradually narrowing section between the vortex chamber and the vertical shaft, generally a frustum-shaped structure wider at the top and narrower at the bottom. Because traditional vertical shaft vortex spillway tunnels are complex, they do not meet the requirements of simple and flexible layout of lower reservoir spillway structures in pumped storage power stations. Furthermore, under medium to large discharge volumes, backwater and blockage are prone to occur at the gradually narrowing section, preventing the formation of a continuous cavity and causing cavitation erosion, thus affecting structural and operational safety. Summary of the Invention

[0003] The purpose of this invention is to provide a structure that solves the problem of backflow at the inlet of a vertical shaft vortex chamber, thereby solving the problem of backflow causing blockage at the inlet of a traditional vertical shaft vortex chamber.

[0004] Another objective of this invention is to provide a method for solving the problem of backflow at the inlet of a vertical shaft vortex chamber.

[0005] The technical solution adopted in this invention is a structure for solving the problem of backflow at the inlet of a vertical shaft vortex chamber, including a vortex chamber, a vortex chamber connecting section upstream of the vortex chamber, an upper horizontal tunnel section upstream of the vortex chamber connecting section, a vertical shaft connected to the bottom outlet of the vortex chamber, a stilling well connected to the bottom outlet of the vertical shaft, a flood discharge passage opening on the side of the stilling well, a vertical shaft connecting section connected to the side of the stilling well at the flood discharge passage, and a drainage tunnel connected to the outlet end of the vertical shaft connecting section.

[0006] The invention is further characterized by: The vortex chamber connecting section has a hollow box structure. The vortex chamber connecting section includes a bottom plate, an inner side wall of the vortex chamber connecting section fixed to one side of the bottom plate, and an outer side wall of the vortex chamber connecting section fixed to the other side of the bottom plate. The top of the inner side wall and the outer side wall of the vortex chamber connecting section are connected to a top plate of the vortex chamber connecting section. A guide sill is fixed between the bottom plate and the top plate of the vortex chamber connecting section on the inner side wall. The guide sill is perpendicular to the bottom plate and the top plate of the vortex chamber connecting section. The inner side wall and the outer side wall of the vortex chamber connecting section are both connected to the vortex chamber. The outer sidewall of the vortex chamber connecting section includes a straight section sidewall, which corresponds to the inner sidewall of the vortex chamber connecting section. One side of the straight section sidewall is connected to the upper flat tunnel section, and the other side of the straight section sidewall is connected to a quarter-circle arc section sidewall. One end of the quarter-circle arc section sidewall is tangent to the straight section sidewall, and the other end of the quarter-circle arc section sidewall is connected to the vortex chamber sidewall.

[0007] The bottom plate of the vortex chamber connection section includes the Wochi section. The inlet end of the Wochi section is connected to the upper flat tunnel section, and the outlet end of the Wochi section is connected to the steep slope section. The steep slope section has an arc-shaped structure that extends into the vertical shaft. The Wochi section is tangent to the steep slope section, and the steep slope section is connected to the sidewall of the vortex chamber.

[0008] The guide sill has a right-angled triangular cross-section and a trapezoidal longitudinal section. The guide sill starts at the inlet of the Wochi section and extends along the water flow direction. Its end is located 1-2 times the width of the vortex chamber inlet. The width of the guide sill's end is 30-70% of the width of the bottom plate of the vortex chamber connection section. The angle between the end face of the guide sill and the inner sidewall of the vortex chamber connection section is 90°. The shape of the Wochi section satisfies the parabolic equation Y=kX+cX. 2 , where k and c are constants.

[0009] The inner wall of the vortex chamber is provided with a flow guide sill, which is located on the inner wall at the inlet of the vortex chamber. The flow guide sill is located near the inner side wall of the vortex chamber connection section and is flush with the vortex chamber.

[0010] The inner diameter of the vertical shaft is equal to the inner diameter of the vortex chamber. The energy dissipation well has a structure that combines a semi-cylinder and a box. The side wall of the semi-cylinder is tangent to the side wall of the box. The width of the energy dissipation well is equal to the inner diameter of the vertical shaft, and the length of the energy dissipation well is twice the length of the inner diameter of the vertical shaft.

[0011] The length of the shaft connection section is equal to four times the inner diameter of the shaft, and the bottom plate of the shaft connection section and the outer wall of the stilling well are chamfered.

[0012] Another technical solution adopted in this invention is a method for solving the problem of backflow at the inlet of a vertical shaft vortex chamber, comprising the following steps: S1. Water from the reservoir enters the vortex chamber connection section via the upper flat tunnel section; S2. The water flow entering the vortex chamber connection section is accelerated into the vortex chamber due to the slope of the vortex chamber connection section and the converging effect of the guide sill. S3. The water flowing into the vortex chamber rotates through the vortex chamber wall to the guide sill. The guide sill changes the direction of the water flow. Due to the angle between the end of the guide sill and the inner side wall of the vortex chamber connection section and the distance between the end of the guide sill and the vortex chamber inlet, backflow at the vortex chamber inlet is avoided, and the water flow is guided into the vertical shaft. S4. The water flowing into the vertical shaft is slowed down by the stilling well and flows into the vertical shaft connection section, and finally flows out through the drainage tunnel.

[0013] The beneficial effects of this invention are: The structure and method provided by this invention for solving the problem of backflow at the inlet of a vertical shaft vortex chamber effectively prevent backflow caused by water entering the vortex chamber and impacting the inner wall during flood discharge or venting. This prevents backflow from colliding with the incoming flow and reduces the flow velocity entering the vortex chamber. The combination of the Wochi section and the steep slope section guides the water flow smoothly into the vortex chamber, ensuring that the standing wave height of the vortex chamber remains within a safe range. The "one-vortex-to-the-end" structure simplifies construction and saves costs, effectively preventing water choking and blockage in the vertical shaft section under medium and large discharge volumes. It also forms a large through cavity, effectively preventing cavitation and erosion inside the vertical shaft, thereby ensuring the stability and safety of the vertical shaft structure. Attached Figure Description

[0014] Figure 1 This is a structural diagram of the structure of the present invention for solving the problem of backflow water at the inlet of the vertical shaft vortex chamber.

[0015] Figure 2 This is a top view of the structure of the present invention that solves the problem of water return at the inlet of the vertical shaft vortex chamber.

[0016] In the diagram, 1. Upper flat tunnel section, 2. Vortex chamber connecting section, 21. Wochi section, 22. Steep slope section, 3. Vortex chamber, 31. Diversion sill, 4. Vertical shaft, 5. Guide sill, 6. Inner side wall of vortex chamber connecting section, 7. Outer side wall of vortex chamber connecting section, 71. Side wall of straight section, 72. Side wall of quarter-circle arc section, 8. Stilling well, 9. Vertical shaft connecting section, 10. Drainage tunnel, 11. Bottom plate of vortex chamber connecting section, 12. Top plate of vortex chamber connecting section. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0018] The structure provided by this invention for solving the problem of backflow at the inlet of a vertical shaft vortex chamber, such as... Figure 1 As shown, it includes a vortex chamber 3, with a vortex chamber connecting section 2 upstream of the vortex chamber 3, an upper horizontal tunnel section 1 upstream of the vortex chamber connecting section 2, a vertical shaft 4 connected to the bottom outlet of the vortex chamber 3, a stilling well 8 connected to the bottom outlet of the vertical shaft 4, a flood discharge passage opening on the side of the stilling well 8, a vertical shaft connecting section 9 connected to the flood discharge passage on the side of the stilling well 8, and a drainage tunnel 10 connected to the outlet end of the vertical shaft connecting section 9. Figure 2As shown, the vortex connecting section 2 has a hollow box structure. The vortex connecting section 2 includes a bottom plate 11. An inner sidewall 6 is fixed to one side of the bottom plate 11, and an outer sidewall 7 is fixed to the other side. A top plate 12 is connected to both the inner sidewall 6 and the outer sidewall 7. The bottom plate 11 and the top plate 12 are located at the inner sidewall of the vortex connecting section. Guide curbs 5 are fixed to the inner side of wall 6. The guide curbs 5 are perpendicular to the bottom plate 11 and the top plate 12 of the vortex chamber connecting section. The inner side wall 6 and the outer side wall 7 of the vortex chamber connecting section are connected to the vortex chamber 3. The outer side wall 7 of the vortex chamber connecting section includes a straight section side wall 71, which corresponds to the inner side wall 6 of the vortex chamber connecting section. One side of the straight section side wall 71 is connected to the upper flat tunnel section 1, and the other side of the straight section side wall 71 is connected to a quarter-circle arc section side wall. 72, one end of the quarter-circular arc section sidewall 72 is tangent to the straight section sidewall 71, and the other end of the quarter-circular arc section sidewall 72 is connected to the sidewall of the vortex chamber 3; the bottom plate 11 of the vortex chamber connecting section includes the Wochi section 21, the inlet end of the Wochi section 21 is connected to the upper flat tunnel section 1, and the outlet end of the Wochi section 21 is connected to the steep slope section 22, the steep slope section 22 has an arc-shaped structure, the arc-shaped structure extends towards the vertical shaft 4, the Wochi section 21 is tangent to the steep slope section 22, and the steep slope section 22 is connected to the sidewall of the vortex chamber 3; guide sill The cross-section of guide sill 5 is a right-angled triangle, and the longitudinal section of guide sill 5 is trapezoidal. The starting point of guide sill 5 is located at the inlet end of Wochi section 21. Guide sill 5 extends along the water flow direction and its end is located at a distance of 1-2 times the width of the inlet of vortex chamber 3. The width of the end of guide sill 5 is 30-70% of the width of the bottom plate 11 of the vortex chamber connecting section. The angle between the end face of guide sill 5 and the inner sidewall 6 of the vortex chamber connecting section is 90°. The shape of Wochi section 21 satisfies the parabolic equation Y=kX+cX. 2Where k and c are constants, the guide sill 5 prevents the backflow formed by the flow direction change and impact on the inner wall of the vortex chamber 3 when the supercritical flow enters the vortex chamber 3 through the upper flat tunnel section 1, thus preventing the backflow phenomenon before the inlet of the vortex chamber 3 from being significantly weakened; the inner wall of the vortex chamber 3 is provided with a guide sill 31, which is located on the inner wall at the inlet of the vortex chamber 3 and is located close to the inner side wall 6 of the vortex chamber connecting section, and is flush with the vortex chamber 3; the inner diameter of the vertical shaft 4 is equal to the inner diameter of the vortex chamber 3, and the stilling well 8 has a structure that combines a semi-cylinder and a box body, with the side wall of the semi-cylinder tangent to the side wall of the box body, the width of the stilling well 8 is equal to the inner diameter of the vertical shaft 4, and the length of the stilling well 8 is equal to twice the inner diameter of the vertical shaft 4; the length of the vertical shaft connecting section 9 is equal to four times the inner diameter of the vertical shaft 4, and the bottom plate of the vertical shaft connecting section 9 and the outer wall of the stilling well 8 are chamfered. While ensuring the formation of a complete, continuous spiral flow through the cavity, it effectively solves the problem of water backlog and blockage at the gradual contraction section of the vertical shaft 4 under medium and large discharge conditions. Furthermore, the structure is simple, easy to construct, and cost-effective. After the water flows through the guide sill 5 into the vortex chamber 3, it impacts the inner wall of the vortex chamber 3, forming an outer rotating flow. When the backflow impacts the end of the guide sill 5, the impact energy is significantly weakened by the blocking effect of the guide sill 5's structure, effectively mitigating the impact and backlog phenomena caused by the outer rotating mainstream on the mainstream entering the vortex chamber 3. Through the combined effect of the guide sill 5 and the bottom plate 11 of the vortex chamber connection section, the thickness of the rotating water flow inside the vortex chamber 3 increases, the water surface rise is significantly reduced, and the water surface height difference within the rotating water flow inside the vortex chamber 3 is also reduced. The lower gradual transition section of the vertical shaft 4 forms different rotating flow layers inside and outside, further enhancing the transition energy dissipation effect of the vortex chamber connection section 2.

[0019] Example 1 The structure proposed in this embodiment for solving the problem of backflow at the inlet of the vertical shaft vortex chamber is as follows: Figure 1 As shown, it includes a vortex chamber 3, a vortex chamber connecting section 2 connected upstream of the vortex chamber 3, an upper horizontal tunnel section 1 connected upstream of the vortex chamber connecting section 2, a vertical shaft 4 connected to the bottom outlet of the vortex chamber 3, a stilling well 8 connected to the bottom outlet of the vertical shaft 4, a flood discharge passage opening on the side of the stilling well 8, a vertical shaft connecting section 9 connected to the side of the stilling well 8 at the flood discharge passage, and a drainage tunnel 10 connected to the outlet end of the vertical shaft connecting section 9.

[0020] Example 2 The structure proposed in this embodiment for solving the problem of backflow at the inlet of the vertical shaft vortex chamber is as follows: Figure 1 As shown, it includes a vortex chamber 3, with a vortex chamber connecting section 2 upstream of the vortex chamber 3, an upper horizontal tunnel section 1 upstream of the vortex chamber connecting section 2, a vertical shaft 4 connected to the bottom outlet of the vortex chamber 3, a stilling well 8 connected to the bottom outlet of the vertical shaft 4, a flood discharge passage opening on the side of the stilling well 8, a vertical shaft connecting section 9 connected to the flood discharge passage on the side of the stilling well 8, and a drainage tunnel 10 connected to the outlet end of the vertical shaft connecting section 9. Figure 2As shown, the vortex connecting section 2 has a hollow box structure. The vortex connecting section 2 includes a bottom plate 11. An inner side wall 6 is fixed to one side of the bottom plate 11, and an outer side wall 7 is fixed to the other side. The top of the inner side wall 6 and the outer side wall 7 are connected to a top plate 12. A guide sill 5 is fixed between the bottom plate 11 and the top plate 12 on the inner side wall 6. The guide sill 5 is perpendicular to both the bottom plate 11 and the top plate 12. The inner side wall 6 and the outer side wall 7 are both connected to the vortex 3. Example 3 The structure proposed in this embodiment for solving the problem of backflow at the inlet of the vertical shaft vortex chamber is as follows: Figure 1 As shown, it includes a vortex chamber 3, with a vortex chamber connecting section 2 upstream of the vortex chamber 3, an upper horizontal tunnel section 1 upstream of the vortex chamber connecting section 2, a vertical shaft 4 connected to the bottom outlet of the vortex chamber 3, a stilling well 8 connected to the bottom outlet of the vertical shaft 4, a flood discharge passage opening on the side of the stilling well 8, a vertical shaft connecting section 9 connected to the flood discharge passage on the side of the stilling well 8, and a drainage tunnel 10 connected to the outlet end of the vertical shaft connecting section 9. Figure 2 As shown, the vortex connecting section 2 has a hollow box structure. The vortex connecting section 2 includes a bottom plate 11. An inner sidewall 6 is fixed to one side of the bottom plate 11, and an outer sidewall 7 is fixed to the other side. A top plate 12 is connected to both the inner sidewall 6 and the outer sidewall 7. A guide sill 5 is fixed between the bottom plate 11 and the top plate 12 on the inner sidewall 6. The guide sill 5 is also fixed to the bottom of the vortex connecting section. Plate 11 and the top plate 12 of the vortex chamber connecting section are perpendicular to each other. The inner side wall 6 and the outer side wall 7 of the vortex chamber connecting section are both connected to the vortex chamber 3. The outer side wall 7 of the vortex chamber connecting section includes a straight section side wall 71, which corresponds to the inner side wall 6 of the vortex chamber connecting section. One side of the straight section side wall 71 is connected to the upper flat tunnel section 1, and the other side of the straight section side wall 71 is connected to a quarter-circle arc section side wall 72. One end of the quarter-circle arc section side wall 72 is tangent to the straight section side wall 71, and the other end of the quarter-circle arc section side wall 72 is connected to the side wall of the vortex chamber 3.

[0021] Example 4 The structure proposed in this embodiment for solving the problem of backflow at the inlet of the vertical shaft vortex chamber is as follows: Figure 1 As shown, it includes a vortex chamber 3, with a vortex chamber connecting section 2 upstream of the vortex chamber 3, an upper horizontal tunnel section 1 upstream of the vortex chamber connecting section 2, a vertical shaft 4 connected to the bottom outlet of the vortex chamber 3, a stilling well 8 connected to the bottom outlet of the vertical shaft 4, a flood discharge passage opening on the side of the stilling well 8, a vertical shaft connecting section 9 connected to the flood discharge passage on the side of the stilling well 8, and a drainage tunnel 10 connected to the outlet end of the vertical shaft connecting section 9. Figure 2 As shown, the vortex chamber connecting section 2 has a hollow box structure. The vortex chamber connecting section 2 includes a bottom plate 11. An inner sidewall 6 is fixed to one side of the bottom plate 11, and an outer sidewall 7 is fixed to the other side. The top of the inner sidewall 6 and the outer sidewall 7 are connected to a top plate 12. A guide sill 5 is fixed between the bottom plate 11 and the top plate 12 on the inner sidewall 6. The guide sill 5 is perpendicular to both the bottom plate 11 and the top plate 12. Both the inner sidewall 6 and the outer sidewall 7 are connected to the vortex chamber 3. The outer sidewall 7 of the connecting section includes a straight section sidewall 71, which corresponds to the inner sidewall 6 of the vortex chamber connecting section. One side of the straight section sidewall 71 is connected to the upper flat tunnel section 1, and the other side of the straight section sidewall 71 is connected to a quarter-circle arc section sidewall 72. One end of the quarter-circle arc section sidewall 72 is tangent to the straight section sidewall 71, and the other end of the quarter-circle arc section sidewall 72 is connected to the sidewall of the vortex chamber 3. The bottom plate 11 of the vortex chamber connecting section includes a Wochi section 21. The inlet end of the Wochi section 21 is connected to the upper flat tunnel section 1, and the outlet end of the Wochi section 21 is connected to a steep slope section 22. The steep slope section 22 has an arc-shaped structure that extends towards the vertical shaft 4. The Wochi section 21 is tangent to the steep slope section 22, and the steep slope section 22 is connected to the sidewall of the vortex chamber 3.

[0022] Example 5 The structure proposed in this embodiment for solving the problem of backflow at the inlet of the vertical shaft vortex chamber is as follows: Figure 1 As shown, it includes a vortex chamber 3, with a vortex chamber connecting section 2 upstream of the vortex chamber 3, an upper horizontal tunnel section 1 upstream of the vortex chamber connecting section 2, a vertical shaft 4 connected to the bottom outlet of the vortex chamber 3, a stilling well 8 connected to the bottom outlet of the vertical shaft 4, a flood discharge passage opening on the side of the stilling well 8, a vertical shaft connecting section 9 connected to the flood discharge passage on the side of the stilling well 8, and a drainage tunnel 10 connected to the outlet end of the vertical shaft connecting section 9. Figure 2As shown, the vortex connecting section 2 has a hollow box structure. The vortex connecting section 2 includes a bottom plate 11. An inner sidewall 6 is fixed to one side of the bottom plate 11, and an outer sidewall 7 is fixed to the other side. A top plate 12 is connected to both the inner sidewall 6 and the outer sidewall 7. The bottom plate 11 and the top plate 12 are located at the inner sidewall of the vortex connecting section. Guide curbs 5 are fixed to the inner side of wall 6. The guide curbs 5 are perpendicular to the bottom plate 11 and the top plate 12 of the vortex chamber connecting section. The inner side wall 6 and the outer side wall 7 of the vortex chamber connecting section are connected to the vortex chamber 3. The outer side wall 7 of the vortex chamber connecting section includes a straight section side wall 71, which corresponds to the inner side wall 6 of the vortex chamber connecting section. One side of the straight section side wall 71 is connected to the upper flat tunnel section 1, and the other side of the straight section side wall 71 is connected to a quarter-circle arc section side wall. 72, one end of the quarter-circular arc section sidewall 72 is tangent to the straight section sidewall 71, and the other end of the quarter-circular arc section sidewall 72 is connected to the sidewall of the vortex chamber 3; the bottom plate 11 of the vortex chamber connecting section includes the Wochi section 21, the inlet end of the Wochi section 21 is connected to the upper flat tunnel section 1, and the outlet end of the Wochi section 21 is connected to the steep slope section 22, the steep slope section 22 has an arc-shaped structure, the arc-shaped structure extends towards the vertical shaft 4, the Wochi section 21 is tangent to the steep slope section 22, and the steep slope section 22 is connected to the sidewall of the vortex chamber 3; guide sill The cross-section of guide sill 5 is a right-angled triangle, and the longitudinal section of guide sill 5 is trapezoidal. The starting point of guide sill 5 is located at the inlet end of Wochi section 21. Guide sill 5 extends along the water flow direction and its end is located at a distance of 1-2 times the width of the inlet of vortex chamber 3. The width of the end of guide sill 5 is 30-70% of the width of the bottom plate 11 of the vortex chamber connecting section. The angle between the end face of guide sill 5 and the inner sidewall 6 of the vortex chamber connecting section is 90°. The shape of Wochi section 21 satisfies the parabolic equation Y=kX+cX. 2 Where k and c are constants; the inner wall of the vortex chamber 3 is provided with a flow guide sill 31, which is located on the inner wall at the inlet of the vortex chamber 3. The flow guide sill 31 is located near the inner side wall 6 of the vortex chamber connecting section and is flush with the vortex chamber 3; the inner diameter of the vertical shaft 4 is equal to the inner diameter of the vortex chamber 3; the energy dissipation shaft 8 has a structure that combines a semi-cylinder and a box body, with the side wall of the semi-cylinder tangent to the side wall of the box body; the width of the energy dissipation shaft 8 is equal to the inner diameter of the vertical shaft 4; the length of the energy dissipation shaft 8 is equal to twice the inner diameter of the vertical shaft 4; the length of the vertical shaft connecting section 9 is equal to four times the inner diameter of the vertical shaft 4; the bottom plate of the vertical shaft connecting section 9 and the outer wall of the energy dissipation shaft 8 are chamfered.

[0023] Example 6 The method for solving the problem of backflow at the inlet of a vertical shaft vortex chamber, as proposed in this embodiment, specifically includes the following steps, based on the aforementioned structure for solving the problem of backflow at the inlet of a vertical shaft vortex chamber: S1. Water from the reservoir enters the vortex chamber connection section via the upper flat tunnel section; S2. The water flow entering the vortex chamber connection section is accelerated into the vortex chamber due to the slope of the vortex chamber connection section and the converging effect of the guide sill. S3. The water flowing into the vortex chamber rotates through the vortex chamber wall to the guide sill. The guide sill changes the direction of the water flow. Due to the angle between the end of the guide sill and the inner side wall of the vortex chamber connection section and the distance between the end of the guide sill and the vortex chamber inlet, backflow at the vortex chamber inlet is avoided, and the water flow is guided into the vertical shaft. S4. The water flowing into the vertical shaft is slowed down by the stilling well and flows into the vertical shaft connection section, and finally flows out through the drainage tunnel.

Claims

1. A structure for solving the problem of backflow at the inlet of a vertical shaft vortex chamber, characterized in that, Includes a vortex chamber (3), with a vortex chamber connecting section (2) upstream of the vortex chamber (3), an upper horizontal tunnel section (1) upstream of the vortex chamber connecting section (2), a vertical shaft (4) connected to the bottom outlet of the vortex chamber (3), a stilling well (8) connected to the bottom outlet of the vertical shaft (4), a flood discharge passage opening on the side of the stilling well (8), a vertical shaft connecting section (9) connected to the side of the stilling well (8) at the flood discharge passage, and a drainage tunnel (10) connected to the outlet end of the vertical shaft connecting section (9). The vortex connecting section (2) has a hollow box structure. The vortex connecting section (2) includes a bottom plate (11). The bottom plate (11) is fixed to an inner side wall (6) of the vortex connecting section. The bottom plate (11) is fixed to an outer side wall (7) of the vortex connecting section. The top of the inner side wall (6) and the outer side wall (7) of the vortex connecting section are connected to a top plate (12). A guide sill (5) is fixed between the bottom plate (11) and the top plate (12) of the vortex connecting section on the inner side wall (6). The guide sill (5) is perpendicular to the bottom plate (11) and the top plate (12) of the vortex connecting section. The inner side wall (6) and the outer side wall (7) of the vortex connecting section are connected to the vortex (3). The outer sidewall (7) of the vortex chamber connecting section includes a straight sidewall (71), which corresponds to the inner sidewall (6) of the vortex chamber connecting section. One side of the straight sidewall (71) is connected to the upper flat tunnel section (1), and the other side of the straight sidewall (71) is connected to a quarter-circle arc sidewall (72). One end of the quarter-circle arc sidewall (72) is tangent to the straight sidewall (71), and the other end of the quarter-circle arc sidewall (72) is connected to the sidewall of the vortex chamber (3). The bottom plate (11) of the vortex chamber connecting section includes a Wochi section (21), the inlet end of which is connected to the upper flat tunnel section (1), and the outlet end of which is connected to a steep slope section (22). The steep slope section (22) has an arc-shaped structure, which extends toward the vertical shaft (4). The Wochi section (21) is tangent to the steep slope section (22), and the steep slope section (22) is connected to the side wall of the vortex chamber (3). The guide sill (5) has a right-angled triangular cross-section and a trapezoidal longitudinal cross-section. The guide sill (5) starts at the inlet of the Wochi section (21) and extends along the water flow direction. The end of the guide sill (5) is located at a distance of 1-2 times the width of the vortex chamber (3) inlet. The width of the end of the guide sill (5) is 30-70% of the width of the bottom plate (11) of the vortex chamber connecting section. The angle between the end face of the guide sill (5) and the inner side wall (6) of the vortex chamber connecting section is 90°. The shape of the Wochi section (21) satisfies the parabolic equation Y=kX+cX. 2 , where k and c are constants.

2. The structure for solving the problem of backflow at the inlet of a vertical shaft vortex chamber according to claim 1, characterized in that, The inner wall of the vortex chamber (3) is provided with a flow guide (31). The flow guide (31) is located on the inner wall at the inlet of the vortex chamber (3). The flow guide (31) is located close to the inner side wall (6) of the vortex chamber connecting section. The flow guide (31) is flush with the vortex chamber (3).

3. The structure for solving the problem of backflow at the inlet of a vertical shaft vortex chamber according to claim 2, characterized in that, The inner diameter of the vertical shaft (4) is equal to the inner diameter of the vortex chamber (3). The energy dissipation well (8) has a structure that combines a semi-cylinder with a box body. The side wall of the semi-cylinder is tangent to the side wall of the box body. The width of the energy dissipation well (8) is equal to the inner diameter of the vertical shaft (4). The length of the energy dissipation well (8) is twice the length of the inner diameter of the vertical shaft (4).

4. The structure for solving the problem of backflow at the inlet of the vortex chamber in a vertical shaft according to claim 3, characterized in that, The length of the vertical shaft connecting section (9) is equal to 4 times the inner diameter of the vertical shaft (4), and the bottom plate of the vertical shaft connecting section (9) and the outer wall of the stilling well (8) are chamfered.

5. A method for solving the problem of backflow at the inlet of a vertical shaft vortex chamber, characterized in that, The structure for solving the problem of backflow at the inlet of the vortex chamber in a vertical shaft, as described in claim 4, specifically includes the following steps: S1. Water from the reservoir enters the vortex chamber connection section via the upper flat tunnel section; S2. The water flow entering the vortex chamber connection section is accelerated into the vortex chamber due to the slope of the vortex chamber connection section and the converging effect of the guide sill. S3. The water flowing into the vortex chamber rotates through the vortex chamber wall to the guide sill. The guide sill changes the direction of the water flow. Due to the angle between the end of the guide sill and the inner side wall of the vortex chamber connection section and the distance between the end of the guide sill and the vortex chamber inlet, backflow at the vortex chamber inlet is avoided, and the water flow is guided into the vertical shaft. S4. The water flowing into the vertical shaft is slowed down by the stilling well and flows into the vertical shaft connection section, and finally flows out through the drainage tunnel.

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