Ventilation system for deep drain hole emergency gate

Abstract

The invention discloses a ventilation system, particularly discloses a ventilation system for a deep drain hole emergency gate, and belongs to the technical field of design and manufacturing of water conservancy and hydropower engineering structures. The ventilation system for the deep drain hole emergency gate can effectively improve the flow state of downward water flow and further effectively reduce the cavitation damage degree. The ventilation system comprises a high concrete dam, a deep drainage hole is formed in the high concrete dam, an accident overhaul lock chamber structure is arranged on the high concrete dam on the upstream side of the deep drainage hole, the ventilation system further comprises a ventilation hole and a flow state composite adjusting structure, and the flow state composite adjusting structure is arranged on the high concrete dam at the outlet end of the ventilation hole. The vent hole is vertically formed in the high concrete dam on the downstream side of the accident overhaul lock chamber structure in a manner of adapting to the position of a door groove of the accident overhaul lock chamber structure; the flow state, located on the downstream side of the accident overhaul lock chamber structure, of discharged high-speed water flow is adjusted and kept stable through the flow state composite adjusting structure under the cooperation of the deep water drainage holes.

Description

TECHNICAL FIELD

[0001] The present application relates to a ventilation system, in particular to a ventilation system for a deep-type drain hole emergency gate, belonging to the technical field of water conservancy and hydropower engineering structure design and manufacturing. BACKGROUND

[0002] 1. Professional term explanation 1) Cavitation Cavitation refers to the rapid expansion of micro-bubbles or gas nuclei originally contained in the water body when the water pressure decreases to a certain critical value, forming bubbles containing water vapor and other gases in the water, even causing a large amount of vaporization, forming a phenomenon similar to boiling. Cavitation is a result of hydrodynamic action, that is, cavitation is a local flow phenomenon caused by increased flow rate and reduced pressure, including the process of cavitation bubble generation, development and disappearance, and is a dynamic flow phenomenon.

[0003] 2) Erosion Cavitation is random and can occur in the water body or at the edge wall part connected to the solid. When cavitation occurs near the solid surface, the large instantaneous pressure generated by the collapse of the cavitation bubble repeatedly acts on the solid surface, causing damage to the solid surface, which is called erosion. Cavitation erosion is the result of the combined action of cavitation damage and the anti-erosion strength of the edge wall material, and generally belongs to fatigue failure.

[0004] 3) Deep-type drain hole The drain hole located in the middle and bottom of the concrete dam is called the deep-type drain hole of the concrete dam, also known as the deep hole. The deep-type drain hole is the main drain passage of the concrete dam body, with the characteristics of large opening size, high operating water head and outflow velocity, and prominent cavitation and erosion risk, and its working state is of decisive significance to the safe operation of the project. The deep-type drain hole of the concrete dam is usually of a long pressure hole type, composed of an inlet section, a hole body section and an outlet section, with a flat emergency inspection gate at the inlet and an arc-shaped working gate at the outlet.

[0005] 4) Emergency gate An emergency gate is a gate that can cut off the water flow in moving water to deal with accidents occurring downstream of the flow passage. It is usually arranged in front of the working gate of the discharge structure and is generally closed in moving water and opened in static water.

[0006] 5) Emergency gate air hole The emergency gate air hole is generally arranged on the downstream side of the emergency gate, and its main functions include: When the emergency gate is closed in moving water, air is supplied to the flow passage to avoid negative pressure behind the gate and thus cause erosion damage to the gate and gate slot structure; When the emergency gate is opened in still water, the gas in the flow passage is discharged to ensure the balance of water pressure upstream and downstream of the emergency gate.

[0007] 2. Structure type of deep type spillway of high concrete dam.

[0008] The deep type spillway of high concrete dam usually adopts long pressure spillway type, which is composed of inlet section, body section and outlet section. 1) The inlet section of the deep type spillway of high concrete dam is composed of inlet pier, inlet bracket, emergency gate slot, emergency gate air vent, and emergency gate slot bottom sill. 2) The outlet section of the deep type spillway of high concrete dam is composed of outlet pier, support beam of working radial gate, outlet bracket, working radial gate slot, working radial gate bottom sill, and working radial gate hoist house.

[0009] 3. Conventional shape of emergency gate air vent of deep type spillway of high concrete dam and main problems 1) Conventional shape of emergency gate air vent of deep type spillway of high concrete dam The deep type spillway of high concrete dam has high operating water head and flow velocity, and the emergency gate air vent is usually arranged downstream of the emergency gate slot and at the top curve part of the inlet of the body section, which usually has the following structural characteristics: The emergency gate air vent is a rectangular hole arranged parallel to the emergency gate slot and adopts equal-width structure. The width of the emergency gate air vent is smaller than the width of the body section, and side banks are formed on both sides of the top of the body section in the area of the emergency gate air vent. There is a downstream bank formed by the downstream edge line of the emergency gate air vent and the top curve of the inlet of the body section downstream of the emergency gate air vent, and the downstream bank is non-streamline-shaped.

[0010] 2) Main problems The width of the emergency gate air vent is smaller than the width of the body section, and side banks are formed on both sides of the top of the body section in the area of the emergency gate air vent. When the water flow at the top of the body section passes through the area of the emergency gate air vent, the water flow will be divided into three parts in the vertical direction of the water flow, i.e. the water flow adhering to the side banks and the water flow entering the air vent in the middle, and the continuity of the water flow at the top of the body section is destroyed; the water flow in the middle and on both sides is mixed with each other, and the flow state is more turbulent, which is not conducive to the stable control of the water flow in the body section.

[0011] There is a downstream ridge (non-streamlined) formed by the downstream edge line of the sluice groove and the top curve of the hole body section downstream of the air vent of the emergency gate. When the water flow passes the upstream corner point of the air vent of the emergency gate, the water flow diffuses due to the sudden change of the boundary, and the water flow separates from the edge wall; the diffused water flow entering the air vent of the emergency gate will form a stable vortex, and when the diffused water flow passes the downstream ridge of the air vent of the emergency gate, the diffused water flow will be separated from the wall surface again, and the downstream side of the downstream ridge and the top curve part of the hole body section will have a phenomenon of pressure reduction, and the pressure reduction to a certain extent will cause water flow cavitation (i.e. separation cavitation) and cavitation erosion damage to the top of the hole body section. SUMMARY

[0012] The technical problem to be solved by the present application is to provide a ventilation system for a deep discharge hole emergency gate, which can effectively improve the flow pattern of discharged water flow and effectively reduce the degree of cavitation erosion damage.

[0013] The technical scheme adopted to solve the above technical problem is: a ventilation system for a deep discharge hole emergency gate, comprising a high concrete dam, a deep discharge hole is arranged on the high concrete dam, an emergency maintenance gate chamber structure is arranged on the high concrete dam on the upstream side of the deep discharge hole, the ventilation system further comprises an air vent and a flow pattern composite adjustment structure, the flow pattern composite adjustment structure is arranged on the high concrete dam at the outlet end of the air vent, the air vent is arranged in the high concrete dam on the downstream side of the emergency maintenance gate chamber structure in the vertical direction and adapted to the position of the gate groove of the emergency maintenance gate chamber structure; the high-speed water flow discharged under the cooperation of the deep discharge hole is adjusted and kept stable by the flow pattern composite adjustment structure on the downstream side of the emergency maintenance gate chamber structure.

[0014] Further, an inlet bracket and an inlet gate pier are arranged on the high concrete dam on the upstream side of the deep discharge hole, the emergency maintenance gate chamber structure is arranged on the high concrete dam on the upstream side of the deep discharge hole through the inlet bracket and the inlet gate pier, and the air vent is arranged on the high concrete dam between the inlet gate pier and the upstream basic body curve in the vertical direction.

[0015] The preferred mode of the above scheme is that the width of at least the air vent is smaller than the width of the deep discharge hole.

[0016] Further, the flow pattern composite adjustment structure at least comprises an air vent outlet end adjustment mechanism, and the high-speed water flow discharged under the cooperation of the deep discharge hole is adjusted and kept stable by the air vent outlet end adjustment mechanism at the two side positions in the width direction of the outlet end of the air vent.

[0017] The preferred mode of the above scheme is that the air vent outlet end adjusting mechanism is an enlarged groove arranged at the air vent outlet end along the width direction of the deep type spillway, the width of the enlarged groove is adapted to the width of the deep type spillway, and the side ridge between the two side surfaces of the air vent outlet end along the width direction and the top surface of the deep type spillway is arranged in the enlarged groove.

[0018] Further, the flow state composite adjusting structure further comprises a cross-section flow state adjusting mechanism, and the high-speed spillway flow is located at the flow state of the downstream side end surface of the air vent along the water flow direction and is adjusted and kept stable by the cross-section flow state adjusting mechanism.

[0019] The preferred mode of the above scheme is that the cross-section flow state adjusting mechanism is an arc-shaped streamlined transition ridge arranged at the downstream side end surface of the air vent outlet end along the water flow direction and the downstream side end surface of the enlarged groove.

[0020] Further, the high concrete dam at the outlet end of the deep type spillway is further provided with an erosion reduction drop ridge.

[0021] The preferred mode of the above scheme is that the erosion reduction drop ridge is a vertical bending expansion cavity arranged at the outlet end of the deep type spillway.

[0022] The beneficial effects of the present application are that the technical scheme provided by the present application is based on the existing high concrete dam, combined with the structural characteristics that the deep type spillway is arranged on the high concrete dam and the accident maintenance gate chamber structure is arranged on the high concrete dam on the upstream side of the deep type spillway, and further arranged with the air vent and the flow state composite adjusting structure to constitute the air vent system of the present application, then the flow state composite adjusting structure is arranged on the high concrete dam at the inlet end of the air vent, and the air vent is arranged in the high concrete dam on the downstream side of the accident maintenance gate chamber structure along the vertical direction and adapted to the position of the gate slot of the accident maintenance gate chamber structure, and finally the high-speed water flow under the deep type spillway is located at the flow state on the downstream side of the accident maintenance gate chamber structure and is adjusted and kept stable by the flow state composite adjusting structure. Thus, the flow state of the spillway flow is effectively improved, and the degree of cavitation erosion damage is effectively reduced. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a structural schematic view of the air vent system for the deep type spillway accident gate of the present application. Figure 2 It is a structural schematic view of the air vent system for the deep type spillway accident gate of the present application. Figure 1 It is an A-A sectional view of the air vent system for the deep type spillway accident gate of the present application.

[0024] In the figure, the marks are: high concrete dam 1, deep type spillway 2, air vent 3, inlet bracket 4, inlet gate pier 5, enlarged groove 6, side ridge 7, arc-shaped streamlined transition ridge 8, and erosion reduction drop ridge 9. DETAILED DESCRIPTION

[0025] As Figure 1 , Figure 2The application provides a ventilation system for the emergency gate of the deep discharge hole, which can effectively improve the flow state of the discharged water flow and effectively reduce the degree of cavitation damage. The ventilation system comprises a high concrete dam 1, a deep discharge hole 2 arranged on the high concrete dam 1, an emergency maintenance gate chamber structure arranged on the high concrete dam 1 on the upstream side of the deep discharge hole, a ventilation hole 3 and a flow state composite adjustment structure. The flow state composite adjustment structure is arranged on the high concrete dam 1 at the inlet end of the ventilation hole 3. The ventilation hole 3 is arranged in the high concrete dam 1 on the downstream side of the emergency maintenance gate chamber structure along the vertical direction and is adapted to the position of the gate groove of the emergency maintenance gate chamber structure. The high-speed water flow discharged under the cooperation of the deep discharge hole 2 is adjusted and kept stable by the flow state composite adjustment structure on the downstream side of the emergency maintenance gate chamber structure. The technical scheme provided by the application is based on the existing high concrete dam, combined with the structural characteristics that the deep discharge hole is arranged on the high concrete dam and the emergency maintenance gate chamber structure is arranged on the high concrete dam on the upstream side of the deep discharge hole, and then the ventilation hole and the flow state composite adjustment structure are arranged to constitute the ventilation system of the application. Then the flow state composite adjustment structure is arranged on the high concrete dam at the inlet end of the ventilation hole, and the ventilation hole is arranged in the high concrete dam on the downstream side of the emergency maintenance gate chamber structure along the vertical direction and is adapted to the position of the gate groove of the emergency maintenance gate chamber structure. Finally, the high-speed water flow discharged under the cooperation of the deep discharge hole is adjusted and kept stable by the flow state composite adjustment structure on the downstream side of the emergency maintenance gate chamber structure. Thus, the purpose of effectively improving the flow state of the discharged water flow and effectively reducing the degree of cavitation damage is achieved. According to the arrangement characteristics of the existing deep discharge hole, the high concrete dam 1 on the upstream side of the deep discharge hole 2 is further provided with an inlet bracket 4 and an inlet gate pier 5. The emergency maintenance gate chamber structure is arranged on the high concrete dam 1 on the upstream side of the deep discharge hole 2 through the inlet bracket 4 and the inlet gate pier 5. The ventilation hole 3 is arranged on the high concrete dam 1 between the inlet gate pier 5 and the basic body contour line on the upstream side of the high concrete dam along the vertical direction. Accordingly, the ventilation hole 3 provided by the application has a width which is at least smaller than the width of the deep discharge hole 2.

[0026] Correspondingly, in combination with the prior art and the structural features of the existing high concrete dam, the flow state composite adjustment structure at least comprises an air vent outlet end adjustment mechanism. The high-speed water flow discharged from the deep discharge hole 2 is adjusted and kept stable by the air vent outlet end adjustment mechanism at the two side positions of the air vent outlet end along the width direction. At this time, the air vent outlet end adjustment mechanism is preferably an enlarged groove 6 arranged at the air vent outlet end along the width direction of the deep discharge hole. The width of the enlarged groove 6 is adapted to the width of the deep discharge hole 2, and the two side ridges 7 between the air vent outlet end along the width direction and the top surface of the deep discharge hole are arranged in the enlarged groove 6. Further, in order to maximize the flow state of the high-speed discharged water flow, the flow state composite adjustment structure of the application further comprises a cross-section flow state adjustment mechanism. The flow state of the high-speed discharged water flow at the downstream side end surface of the air vent 3 along the water flow direction is adjusted and kept stable by the cross-section flow state adjustment mechanism. Preferably, the cross-section flow state adjustment mechanism is an arc-shaped streamlined transition ridge 8 arranged at the downstream side end surface of the air vent outlet end along the water flow direction and the downstream side end surface of the enlarged groove along the water flow direction.

[0027] At the same time, in order to minimize the cavitation damage of the discharged water flow to the high concrete dam, the application further provides an erosion reduction drop ridge 9 arranged at the outlet end of the deep discharge hole of the high concrete dam 1. Preferably, the erosion reduction drop ridge 9 is a vertical bending expansion cavity arranged at the outlet end of the deep discharge hole.

[0028] In summary, the above technical solutions provided by the application also have the following advantages, 1) The continuity and stability of the water flow at the top of the hole section are good. Since the accident gate air vent adopts an upper-narrow lower-wide structure type, the width of the lower section of the accident gate air vent is the same as the width of the hole section. When the water flow at the top of the hole section passes through the lower section of the accident gate air vent, the water flow will not appear again in the vertical water flow direction. The continuity of the water flow is guaranteed. In addition, since there is no mixing of the water flow at the middle and both sides, the flow state and stability of the water flow are also improved.

[0029] 2) The separation cavitation at the top of the lower section of the accident gate air vent is reduced. Since the lower edge of the accident gate air vent is connected to the top curve of the hole section inlet by a streamlined curve, that is, the lower edge of the accident gate air vent is a streamlined ridge. When the diffused water flow entering the accident gate air vent passes through the streamlined ridge of the lower edge of the accident gate air vent, the water flow will be tightly attached to the streamlined ridge and the top curve of the hole section inlet to the greatest extent, and the possibility of separation cavitation of the water flow from the edge wall will be significantly reduced.

[0030] The technical solutions of the application are further described below through specific embodiments: The technical problem solved by the present application is to provide an accident gate air vent structure of a deep-type discharge hole of a high concrete dam, which can improve the continuity and stability of water flow at the top of the hole body section and effectively reduce the separation cavitation at the top of the hole body section downstream of the air vent.

[0031] The technical solution adopted by the present application to solve the technical problem is: (1) The deep-type discharge hole of the high concrete dam is composed of an inlet section, a hole body section and an outlet section. (2) The inlet section of the deep-type discharge hole of the high concrete dam is composed of an inlet pier, an inlet bracket, an accident gate slot, an accident gate air vent and an accident gate slot bottom sill. (3) The outlet section of the deep-type discharge hole of the high concrete dam is composed of an outlet pier, a working arc gate support beam, an outlet bracket, a working arc gate slot, a working arc gate bottom sill and a working arc gate hoist house. (4) The accident gate air vent of the deep-type discharge hole of the high concrete dam has the following structural features: 1) The accident gate air vent is a rectangular hole and is arranged parallel to the accident gate slot. 2) The accident gate air vent adopts an upper-narrow-and-lower-wide structure type, the upper section of the accident gate air vent is smaller in width than the hole body section, the lower section of the accident gate air vent is the same in width as the hole body section, a side weir is formed at the position of the cross-section mutation, and the side weir is located above the basic body type at the top of the hole body section and outside the main flow influence range of the water flow of the hole body section. 3) The downstream edge line of the accident gate air vent is connected to the inlet top curve of the hole body section in a streamline curve, that is, the downstream of the accident gate air vent is a streamline weir.

Claims

1. A ventilation system for a deep spillway emergency gate, comprising a high concrete dam (1), a deep spillway (2) provided on the high concrete dam (1), and an emergency maintenance gate chamber structure provided on the high concrete dam (1) upstream of the deep spillway, characterized in that: The ventilation system also includes a ventilation hole (3) and a flow state composite adjustment structure. The flow state composite adjustment structure is arranged on the high concrete dam (1) at the outlet end of the ventilation hole (3). The ventilation hole (3) is set in the high concrete dam (1) on the downstream side of the emergency maintenance gate structure in a vertical direction, which is adapted to the gate slot position of the emergency maintenance gate structure. The flow state of the high-speed water flow discharged under the cooperation of the deep discharge hole (2) on the downstream side of the emergency maintenance gate structure is adjusted and kept stable by the flow state composite adjustment structure.

2. The ventilation system for a deep spillway emergency gate according to claim 1, characterized in that: An inlet bracket (4) and an inlet gate pier (5) are also installed on the high concrete dam (1) upstream of the deep spillway (2). The emergency maintenance gate chamber structure is arranged on the high concrete dam (1) upstream of the deep spillway (2) through the inlet bracket (4) and the inlet gate pier (5). The ventilation hole (3) is arranged vertically on the high concrete dam (1) between the inlet gate pier (5) and the basic shape line upstream of the high concrete dam.

3. The ventilation system for a deep spillway emergency gate according to claim 2, characterized in that: At least the width of the vent (3) is smaller than the width of the deep drain hole (2).

4. The ventilation system for a deep spillway emergency gate according to claim 2 or 3, characterized in that: The flow regime adjustment structure includes at least an adjustment mechanism at the outlet end of the vent. The flow regime of the high-speed water flow discharged under the cooperation of the deep drainage hole (2) at the two sides along the width direction at the outlet end of the vent is adjusted and kept stable by the adjustment mechanism at the outlet end of the vent.

5. The ventilation system for a deep spillway emergency gate according to claim 4, characterized in that: The vent outlet adjustment mechanism is an enlarged groove (6) set at the vent outlet along the width direction of the deep drain hole. The width of the enlarged groove (6) is adapted to the width of the deep drain hole (2). The side sills (7) between the two sides of the vent outlet along the width direction and the top surface of the deep drain hole are arranged in the enlarged groove (6).

6. The ventilation system for a deep spillway emergency gate according to claim 5, characterized in that: The flow regime adjustment structure also includes a cross-sectional flow regime adjustment mechanism. The flow regime of the high-speed downstream water flow located at the downstream end face of the vent (3) along the water flow direction is adjusted and kept stable by the cross-sectional flow regime adjustment mechanism.

7. The ventilation system for a deep spillway emergency gate according to claim 6, characterized in that: The cross-sectional flow adjustment mechanism is an arc-shaped streamlined transition sill (8) set at the downstream end face of the vent outlet along the water flow direction and at the downstream end face of the enlarged groove along the water flow direction.

8. The ventilation system for a deep spillway emergency gate according to claim 7, characterized in that: A corrosion-reducing drop (9) is also installed on the high concrete dam (1) at the end of the deep spillway outlet.

9. The ventilation system for a deep spillway emergency gate according to claim 8, characterized in that: The corrosion-reducing drop (9) is a vertically bent expansion cavity arranged at the end of the outlet of the deep drainage hole.

Images