Long distance tunnel water delivery device

Abstract

The utility model relates to water conveyance engineering technical field, concretely relates to a long distance tunnel water conveyance device. The device includes import box culvert section, water conveyance tunnel section and pressureless tunnel section, import box culvert section, water conveyance tunnel section and pressureless tunnel section are all horizontal section, the import shaft is arranged between import box culvert section and water conveyance tunnel section, the top of import box culvert section is communicated with import shaft, and one end of water conveyance tunnel section is communicated with the bottom of import shaft, the export shaft is arranged between water conveyance tunnel section and pressureless tunnel section, the other end of water conveyance tunnel section is communicated with the bottom of export shaft, and pressureless tunnel section is communicated with the top of export shaft. The utility model can realize tunnel section smooth full pipe, greatly restrain the difficult to predict clear full flow separation point movement, intense pressure pulsation and water flow turbulence in water filling mode.

Description

Technical Field

[0001] This utility model relates to the field of water conveyance engineering technology, and in particular to a long-distance tunnel water conveyance device. Background Technology

[0002] Currently, large-scale water conservancy projects mostly adopt long-distance unpressurized water conveyance. Long-distance water transfer can achieve the rational allocation of water resources and resolve supply and demand contradictions by transporting water from water-rich areas to water-scarce areas, thereby regulating the uneven spatial and temporal distribution of water resources. The initial operation of a long-distance water conveyance system involves complex water filling operations, which are crucial to the safety and stability of the system. During this process, the water flow undergoes changes from unpressurized flow to open full flow and then to pressurized flow. This process often involves complex transient two-phase water-air flow. Due to the variable flow regime, pressure and velocity vary greatly, and the flow characteristics change with tunnel shape, different gate opening combinations, and other factors.

[0003] However, due to the numerous and complex hydraulic structures within long-distance tunnel water conveyance systems, the location of the open-flow / full-flow separation point is difficult to predict under extreme operating conditions and shifts with changes in operating hydraulic conditions. Consequently, the location of the maximum positive and negative pressure values ​​also changes. On the other hand, during the alternation of open and full flow, the water flow turbulence is intense. The contact point between the top water flow and the tunnel roof, as well as the air bladder in the roof cavity, shift and deform with the turbulent flow. This leads to changes in the location, frequency, and amplitude characteristics of pressure pulsations within the tunnel, affecting the transport characteristics and wall stress conditions within the tunnel. Utility Model Content

[0004] The technical problem to be solved by this utility model embodiment is to provide a long-distance tunnel water conveyance device to solve the above-mentioned shortcomings of the existing long-distance tunnel water conveyance system.

[0005] This utility model discloses a long-distance tunnel water conveyance device, including an inlet box culvert section, a water conveyance tunnel section, and a pressureless tunnel section. All three sections are horizontal. An inlet shaft is provided between the inlet box culvert section and the water conveyance tunnel section. The top of the inlet box culvert section is connected to the top of the inlet shaft, and one end of the water conveyance tunnel section is connected to the bottom of the inlet shaft. An outlet shaft is provided between the water conveyance tunnel section and the pressureless tunnel section. The other end of the water conveyance tunnel section is connected to the bottom of the outlet shaft, and the top of the pressureless tunnel section is connected to the top of the outlet shaft.

[0006] Optionally, the end of the water conveyance tunnel section that connects to the inlet box culvert section is higher than the end of the water conveyance tunnel section that connects to the unpressurized tunnel section.

[0007] Optionally, the inlet box culvert section is connected to the side wall of the inlet shaft near the top opening, and the bottom of the inlet shaft is excavated to form a recessed U-shaped buffer section.

[0008] Optionally, a removable protective plate is provided on the inner wall of the U-shaped buffer section.

[0009] Optionally, the junction between the tunnel wall at the top of the water conveyance tunnel section and the inlet shaft has a rounded corner structure.

[0010] Optionally, an inclined vent pipe is provided above the water conveyance tunnel section near the inlet shaft. One end of the vent pipe is connected to the side wall of the inlet shaft near the top opening, and the connection position between the vent pipe and the inlet shaft is higher than the inlet box culvert section. The other end of the vent pipe is connected to the water conveyance tunnel section.

[0011] Optionally, the portion where the exhaust pipe connects to the water conveyance tunnel section has a funnel-shaped structure.

[0012] Optionally, the bottom of the outlet shaft is deepened by excavating vertically downwards into the water conveyance tunnel section.

[0013] Optionally, the cross-section of the inlet box culvert section is rectangular, and the cross-sections of the water conveyance tunnel section, the unpressurized tunnel section, the inlet shaft, and the outlet shaft are all circular.

[0014] Optionally, the inner diameter of the inlet shaft is larger than the inner diameter of the outlet shaft, and the end opening of the inlet shaft is lower than the top opening of the outlet shaft.

[0015] Compared with the prior art, the long-distance tunnel water conveyance device provided by this utility model has the following advantages:

[0016] By setting up inlet and outlet shafts, the connection between the water conveyance tunnel section and the inlet box culvert section and the unpressurized tunnel section is optimized. This utilizes the shaft structure to achieve a smooth transition in water flow direction and flow pattern, as well as the orderly discharge of gas. During the initial water filling phase, water flows downwards through the inlet shaft and partially enters the water conveyance tunnel section, forming a buffer storage area at the bottom of the shaft, creating conditions for subsequent full filling. When the water level in the shafts on both sides is higher than that in the water conveyance tunnel section, the water flows back slowly along a flat water surface line, avoiding violent alternation between open and closed flow. Furthermore, gas can be gradually and evenly discharged through the top of the shaft in the form of bubbles, significantly reducing the risk of air pockets accumulating at the top of the water conveyance tunnel section. Even if a small amount of gas exists locally, the subsequent water flow can effectively drive its flow and discharge it through the outlet shaft, ultimately achieving a smooth full filling of the tunnel section. This process greatly suppresses the movement of the open-flow separation point, strong pressure pulsation, and water flow turbulence that are difficult to predict in traditional water filling methods, reduces the risk of positive and negative pressure extremes caused by transient water-air two-phase flow, and effectively solves the key problems in the initial water filling process of long-distance water conveyance systems. Attached Figure Description

[0017] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0018] Figure 1 A schematic diagram of the overall structure of the long-distance tunnel water conveyance device provided in this embodiment of the utility model.

[0019] The markings in the attached diagram are as follows:

[0020] 1. Inlet box culvert section; 2. Water conveyance tunnel section; 3. Unpressurized tunnel section; 4. Inlet shaft; 41. U-shaped buffer section; 42. Protective plate; 5. Outlet shaft; 51. Deepening section; 6. Exhaust pipe. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The preferred embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0022] This utility model discloses a long-distance tunnel water conveyance device, such as Figure 1 As shown, the tunnel includes an inlet box culvert section 1, a water conveyance tunnel section 2, and an unpressurized tunnel section 3, all of which are horizontal sections. An inlet shaft 4 is located between the inlet box culvert section 1 and the water conveyance tunnel section 2, with the top of the inlet box culvert section 1 connected to the top of the inlet shaft 4, and one end of the water conveyance tunnel section 2 connected to the bottom of the inlet shaft 4. An outlet shaft 5 is located between the water conveyance tunnel section 2 and the unpressurized tunnel section 3, with the other end of the water conveyance tunnel section 2 connected to the bottom of the outlet shaft 5, and the top of the unpressurized tunnel section 3 connected to the top of the outlet shaft 5.

[0023] Through the implementation of the above-described long-distance tunnel water conveyance device embodiment, specific horizontal and vertical connection methods are set for the inlet box culvert section 1, inlet shaft 4, water conveyance tunnel section 2, outlet shaft 5, and unpressurized tunnel section 3, optimizing the initial water filling operation process of the long-distance water conveyance system. Specifically, when water filling begins, the water flows steadily into the inlet box culvert section 1 as an unpressurized flow. After impacting the wall of the inlet shaft 4, it naturally splits into two parts: one part flows directly into the water conveyance tunnel section 2 along the wall, and the other part falls to the bottom of the inlet shaft 4 to form effective water storage. This not only lays the foundation for subsequent flow pattern transformation but also mitigates the impact energy of the water flow. Subsequently, when the water levels in the inlet shaft 4 and outlet shaft 5 successively accumulate and exceed the top height of the water conveyance tunnel section 2, the water flow does not violently fill the tunnel. Instead, it slowly flows back from right to left (i.e., from outlet shaft 5 to inlet shaft 4) in a calm, nearly horizontal water surface state. This backflow process greatly suppresses the violent alternation of open-fill flow patterns, avoiding the strong impact of the water flow cross-section on the tunnel roof and the resulting violent pressure pulsation that occurs during traditional water filling processes. In addition, the openings of both inlet shaft 4 and outlet shaft 5 extend upwards to the ground surface, allowing them to act as natural outlets for gas overflow. The gas accumulated at the top of the water conveyance tunnel section 2 can be smoothly, orderly, and continuously discharged upwards in the form of bubbles through the shaft cross-section, avoiding the risk of irregular movement or large-scale stagnation of gas bubbles at the top of the water conveyance tunnel section 2. Even if a small amount of gas remains in a localized area (such as the inlet section of water conveyance tunnel section 2) during the initial recirculation, the subsequent continuous water flow can effectively carry this residual gas towards the outlet direction and eventually discharge it through the outlet shaft 5, ensuring that the tunnel section achieves a smooth and uniform full filling without gas blockage. At the same time, the three-dimensional structure of the shafts at both ends of water conveyance tunnel section 2 is fully utilized for water volume regulation and pressure buffering. In particular, the water storage area at the bottom of the inlet shaft 4 and the shaft body guide the direction of water flow, providing spatial buffer and time margin for the smooth change of water flow. The multiple recirculation of water flow and the step-like rise of water level in the shaft (from near the tunnel height to finally being level with the unpressurized tunnel section 3) effectively absorb energy, making the hydraulic transition of the entire water filling process extremely smooth. This fundamentally solves the system instability risks caused by unpredictable separation points, airbag movement and deformation, and severe pressure pulsations resulting from strong turbulence during traditional long-distance water conveyance filling processes. It significantly reduces structural stress and operational noise, ensures the integrity of the water conveyance tunnel and its ancillary facilities during the filling stage, and creates optimal starting conditions for the long-term safe and stable operation of subsequent unpressurized water conveyance. It is especially suitable for water conservancy projects with complex working conditions and extremely high requirements for operational safety.

[0024] Furthermore, the end of the water conveyance tunnel section 2 that connects to the inlet box culvert section 1 is higher than the end of the water conveyance tunnel section 2 that connects to the unpressurized tunnel section 3.

[0025] Through the implementation of the above-described long-distance tunnel water conveyance device embodiment, the height difference between the two ends of the water conveyance tunnel section 2 is used to optimize the flow stability and gas discharge efficiency during the water filling process. Specifically, the inclined arrangement of the inlet end of the water conveyance tunnel section 2, which is higher than the outlet end, creates a continuous gravity driving force within the water conveyance tunnel section 2, promoting a smooth, natural flow of water towards the outlet shaft 5, thereby achieving pressureless gravity-flow transport and avoiding water stagnation or repeated oscillations. Secondly, this slope ensures that the gas within the water conveyance tunnel section 2 is constantly driven by the water flow towards the outlet shaft 5, and ultimately discharged in a concentrated manner through the top of the outlet shaft 5, greatly reducing the risk of dispersed gas pockets accumulating at the tunnel roof. Meanwhile, when the water flows into the water conveyance tunnel section 2 from the bottom of the inlet shaft 4, the bottom of the inclined water conveyance tunnel section 2 can quickly guide the water flow along the slope to the outlet end, avoiding local water accumulation or eddy formation. This allows the water conveyance tunnel section 2 to have a stable unidirectional flow state during the open-full flow transition stage, effectively suppressing the transient pressure oscillation caused by the violent alternation of flow states, protecting the safety of the tunnel structure, and greatly improving the reliability of the water filling process of the long-distance water conveyance system.

[0026] Furthermore, the inlet box culvert section 1 is connected to the side wall of the inlet shaft 4 near the top opening, and the bottom of the inlet shaft 4 is excavated to form a recessed U-shaped buffer section 41.

[0027] Furthermore, a removable protective plate 42 is provided on the inner wall of the U-shaped buffer section 41.

[0028] Through the implementation of the above-described long-distance tunnel water conveyance device embodiment, the safety and operational reliability of the shaft structure are significantly improved through multi-dimensional synergistic effects by utilizing the U-shaped buffer section 41 in conjunction with the detachable protective plate 42. Specifically, the U-shaped buffer section 41, with its smooth and continuous curved surface, effectively disperses and transforms the impact force of the high-speed water flow from above into a rotating flow, significantly reducing the direct impact of the water flow on the bottom of the inlet shaft 4. This avoids fatigue cracking or deformation of the bottom of the inlet shaft 4 due to long-term water hammer effects. Simultaneously, the resulting vortex increases the contact area between the water and air, promoting gas escape. Furthermore, the water accumulated at the bottom of the inlet shaft 4 acts as a natural buffer layer, absorbing the kinetic energy of subsequent water flow, allowing the water flow to transition more smoothly into the water conveyance tunnel section 2, reducing water splashing and pressure pulsation. The protective plate 42 installed on the inner wall of the U-shaped buffer section 41 serves as the first barrier in contact with the water flow. It can be made of high impact-resistant and wear-resistant materials to directly withstand the friction and impact of the water flow and possible solid particles. Its detachable characteristics mean that after local wear or damage, there is no need to repair the entire shaft structure, which greatly reduces the difficulty and cost of maintenance and provides double protection for the structural integrity of the long-distance water transmission system under frequent filling and draining conditions.

[0029] Furthermore, the junction between the tunnel wall at the top of water conveyance tunnel section 2 and the inlet shaft 4 has a rounded corner structure.

[0030] Through the implementation of the above-described long-distance tunnel water conveyance device embodiment, the smooth transition of the rounded corner structure eliminates the flow separation zone at the right-angle connection at the top of the traditional water conveyance tunnel section 2, preventing the water flow from forming a low-pressure vortex due to violent turbulence. This allows the water flow to smoothly flow into the water conveyance tunnel section 2 close to the tunnel roof, thereby promoting the natural transport of gas downstream by the continuously moving water body, rather than accumulating into isolated gas masses at the right-angle corner, significantly reducing the probability of gas pocket formation at the tunnel roof. At the same time, the smooth transition provided by the rounded corners reduces the impact energy loss between the water flow and the solid boundary, weakens the intensity of local pressure pulsations, and avoids transient pressure oscillations caused by repeated compression and expansion of the gas pockets. During the critical stage of water filling and venting, this structure, in conjunction with the venting action of the inlet shaft 4, forms a continuous gas discharge channel, ensuring that the gas migrates stably to the top of the inlet shaft 4. Even trace amounts of residual gas will be peeled off the tunnel wall along the curved surface under the continuous compression of the water flow and discharged with the mainstream, completely eliminating the inherent gas "dead zone" hazard of the right-angle structure, and significantly improving the uniformity and safety of the tunnel filling process.

[0031] Furthermore, an inclined exhaust pipe 6 is installed above the water conveyance tunnel section 2 near the inlet shaft 4. One end of the exhaust pipe 6 is connected to the side wall of the inlet shaft 4 near the top opening, and the connection position between the exhaust pipe 6 and the inlet shaft 4 is higher than that of the inlet box culvert section 1. The other end of the exhaust pipe 6 is connected to the water conveyance tunnel section 2.

[0032] Through the implementation of the above-described long-distance tunnel water conveyance device embodiment, one end of the exhaust pipe 6 is connected at a high position to the side wall near the top of the inlet shaft 4 (the connection point is higher than the inlet box culvert section 1), and the other end is inclined downwards and directly connected to the top of the water conveyance tunnel section 2. When gas accumulates at the top of the water conveyance tunnel section 2 (especially air masses formed by sudden changes in flow at the right-angle connection of the inlet or air bubbles brought in by the water flow), the lighter gas naturally gathers towards the highest point of the tunnel top under the action of buoyancy, and the gathered gas can actively overflow upwards through the exhaust pipe 6 into the top of the inlet shaft 4 and be discharged. This further avoids the gas from being trapped and stagnant at the top of the tunnel. Combined with the inlet shaft 4 and the outlet shaft 5, the risk of flow instability caused by gas retention in the water conveyance tunnel section 2 is completely eliminated, providing a refined gas control guarantee for the safe operation of long-distance tunnels.

[0033] Furthermore, the section where the exhaust pipe 6 connects to the water conveyance tunnel section 2 has a funnel-shaped structure.

[0034] Through the implementation of the above-described long-distance tunnel water conveyance device embodiment, the funnel-shaped structure at the connection between the exhaust pipe 6 and the water conveyance tunnel section 2, with its gradually widening opening design, forms a locally enlarged gas accumulation chamber. This effectively increases the coverage area of ​​the laterally distributed gas at the top of the water conveyance tunnel section 2, allowing dispersed bubbles or thin-layer air pockets to naturally converge into the funnel area under buoyancy and temporarily reside there, providing a buffer space for continuous venting. Simultaneously, the constricted neck of the funnel structure guides the gas to accelerate into the exhaust pipe 6, while preventing water backflow and blockage of the channel. The Venturi effect enhances the low-pressure suction force, further eliminating dead zones of gas stagnation within the water conveyance tunnel section 2, making the venting process smoother and more reliable, significantly shortening the full-pipe venting time, and ensuring the full controllability of the gas-liquid two-phase flow.

[0035] Furthermore, the bottom of the outlet shaft 5 is deepened by excavating vertically downwards into the water conveyance tunnel section 2 to form a deeper section 51.

[0036] Through the implementation of the above-described long-distance tunnel water conveyance device embodiment, a natural sedimentation basin is formed at the bottom of the outlet shaft 5 by utilizing the deep trench created by downward excavation. When the silt or debris carried by the water flow enters the outlet shaft 5, it naturally settles and concentrates in the deepening section 51 under the action of gravity, preventing debris from accumulating at the water conveyance tunnel outlet or blocking the outlet shaft 5. The sufficient depth reserved in the deepening section 51 can accommodate a certain amount of sediment without affecting the normal water flow cross section, ensuring that the path of water flowing upward into the unpressurized tunnel section 3 is unobstructed. At the same time, under this structure, the sediment at the bottom of the trench can be directly cleaned by dredging equipment without emptying the entire system, greatly reducing the difficulty of maintenance and downtime losses, and enabling the long-distance water conveyance system to maintain continuous and reliable operation under complex working conditions.

[0037] Furthermore, the cross-section of the inlet box culvert section 1 is rectangular, while the cross-sections of the water conveyance tunnel section 2, the unpressurized tunnel section 3, the inlet shaft 4, and the outlet shaft 5 are all circular.

[0038] Through the implementation of the above-described long-distance tunnel water conveyance device embodiment, the rectangular cross-section inlet box culvert section 1 provides a wide top space and straight sidewalls, facilitating the smooth diffusion and flow control of the initial unpressurized water flow, while adapting to site construction conditions and facilitating connection to surface water channels. The circular cross-section water conveyance tunnel section 2 fully leverages its hydraulic efficiency and structural strength advantages; its uniform circumferential stress provides superior stability under deep burial conditions when bearing external water and soil pressure. The smooth arc surface significantly reduces frictional losses along long-distance water conveyance, and the circular cross-section forms a symmetrical annular water vapor interface when near full pipe flow, providing an ideal flow path for uniform gas migration along the tunnel roof. The circular cross-sections of the inlet shaft 4 and outlet shaft 5 not only optimize the axisymmetric downward or upward flow of vertical water, but their continuous curved structure also facilitates the natural guidance of water flow along the shaft wall to the bottom or top outlet. The circular structure of the unpressurized tunnel section 3 also balances low flow resistance and structural reliability. This enables efficient and low-loss full-flow transportation, enhancing the flow stability, structural durability, and gas-liquid regulation capabilities of the water conveyance system.

[0039] Furthermore, the inner diameter of the inlet shaft 4 is larger than the inner diameter of the outlet shaft 5, and the end opening of the inlet shaft 4 is lower than the top opening of the outlet shaft 5.

[0040] Through the implementation of the above-described long-distance tunnel water conveyance device embodiment, the larger inner diameter of the inlet shaft 4 provides sufficient buffer volume and low-speed flow space. When water is injected at high speed from the inlet box culvert section 1, the cross-sectional expansion effectively reduces the kinetic energy of the water flow, mitigates the impact of falling water, and promotes the smooth flow of water to the water conveyance tunnel section 2. At the same time, the large space slows down the rate of water level rise in the inlet shaft 4, allowing time margin for gas dissipation. The top opening of the inlet shaft 4 is lower than the top opening of the outlet shaft 5, so that the top of the inlet shaft 4 always maintains a relatively low-pressure zone, while the top of the outlet shaft 5 forms a relatively high-pressure zone. Utilizing this pressure gradient difference, combined with the slope of the water conveyance tunnel section 2 itself, a stable gas migration driving force is constructed from the inlet to the outlet: the gas at the top of the water conveyance tunnel section 2 first accumulates at the higher top of the outlet shaft 5 under the action of buoyancy, and finally reaches the top opening of the outlet shaft 5 under the action of buoyancy and pressure difference, and then naturally escapes into the atmosphere or the downstream unpressurized section, thereby realizing directional and continuous gas discharge from the water inlet to the water outlet. It not only ensures a smooth flow transition during the initial water filling stage, but also ensures unobstructed air venting paths throughout the tunnel section, avoiding the risk of pressure oscillations caused by gas accumulation, and significantly improving the safety and reliability of long-distance water transport.

[0041] It should be understood that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some of the technical features; and all such modifications and substitutions should fall within the protection scope of this utility model.

Claims

1. A long-distance tunnel water conveyance device, characterized in that: The long-distance tunnel water conveyance device includes an inlet box culvert section, a water conveyance tunnel section, and an unpressurized tunnel section, all of which are horizontal sections. An inlet shaft is provided between the inlet box culvert section and the water conveyance tunnel section. The top of the inlet box culvert section is connected to the inlet shaft, and one end of the water conveyance tunnel section is connected to the bottom of the inlet shaft. An outlet shaft is provided between the water conveyance tunnel section and the unpressurized tunnel section. The other end of the water conveyance tunnel section is connected to the bottom of the outlet shaft, and the unpressurized tunnel section is connected to the top of the outlet shaft.

2. The long-distance tunnel water conveyance device according to claim 1, characterized in that: The end of the water conveyance tunnel section that connects to the inlet box culvert section is higher than the end of the water conveyance tunnel section that connects to the unpressurized tunnel section.

3. The long-distance tunnel water conveyance device according to claim 1, characterized in that: The inlet box culvert section is connected to the side wall of the inlet shaft near the top opening, and the bottom of the inlet shaft is formed by excavation to create a concave U-shaped buffer section.

4. The long-distance tunnel water conveyance device according to claim 3, characterized in that: The inner wall of the U-shaped buffer section is equipped with a removable protective plate.

5. The long-distance tunnel water conveyance device according to claim 1, characterized in that: The junction between the tunnel wall at the top of the water conveyance tunnel section and the inlet shaft has a rounded corner structure.

6. The long-distance tunnel water conveyance device according to claim 1, characterized in that: An inclined vent pipe is installed above the water conveyance tunnel section near the inlet shaft. One end of the vent pipe is connected to the side wall of the inlet shaft near the top opening, and the connection point between the vent pipe and the inlet shaft is higher than the inlet box culvert section. The other end of the vent pipe is connected to the water conveyance tunnel section.

7. The long-distance tunnel water conveyance device according to claim 6, characterized in that: The section where the exhaust pipe connects to the water conveyance tunnel section has a funnel-shaped structure.

8. The long-distance tunnel water conveyance device according to claim 1, characterized in that: The bottom of the outlet shaft is deepened by excavating vertically downwards into the water conveyance tunnel section.

9. The long-distance tunnel water conveyance device according to claim 1, characterized in that: The cross-section of the inlet box culvert section is rectangular, while the cross-sections of the water conveyance tunnel section, the unpressurized tunnel section, the inlet shaft, and the outlet shaft are all circular.

10. The long-distance tunnel water conveyance device according to claim 9, characterized in that: The inner diameter of the inlet shaft is larger than the inner diameter of the outlet shaft, and the end opening of the inlet shaft is lower than the top opening of the outlet shaft.

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