Testing device for researching transportation characteristics of retained air mass of pressure water delivery pipeline

Abstract

The utility model discloses a test device for researching the transportation characteristics of a detained air mass of a pressure water delivery pipeline, which comprises a plurality of test pipelines which are connected into an annular loop through flanges, at least one test pipeline is a transparent pipeline, and a camera device for collecting images of fluid and the detained air mass in the pipeline is arranged outside the transparent pipeline; a power mechanism which partially extends into the pipeline to drive water flow in the test pipeline to flow is hermetically mounted on the test pipeline, and a valve for injecting and discharging water, a gas injection valve for injecting gas and an electromagnetic flowmeter for monitoring flow are arranged on the test pipeline. The test device of the scheme can accurately simulate the real working condition of the long-distance pressure water delivery pipeline, and provides a reliable platform for deeply exploring the transportation characteristics of the retained air mass.

Description

Technical Field

[0001] This utility model relates to the field of fluid mechanics testing equipment technology, specifically to a testing device for studying the transport characteristics of stagnant gas masses in pressurized water pipelines. Background Technology

[0002] Against the backdrop of uneven global water resource distribution, long-distance pressurized water pipelines have become a key means of resolving the contradiction between water supply and demand, and an important component of the national water network project, with a grand scale and far-reaching significance. However, due to the influence of topographical and geological conditions, the water transmission routes of long-distance pressurized water pipelines are undulating and varied. If the air vent valves are not installed properly or air is not vented in a timely manner during the filling process of tunnels or pipelines, stagnant air masses can easily occur at local high points in the pipeline, which not only affects the water transmission efficiency but also poses safety hazards to the operation of the project.

[0003] From the perspective of water conveyance efficiency, stagnant air masses occupy the internal space of pipelines, reducing the cross-sectional area for water flow and increasing flow resistance. Regarding pipeline safety, when air masses accumulate to a certain extent, under conditions such as changes in water pressure or water hammer, the air masses may suddenly compress or rupture, causing severe pressure fluctuations. These pressure fluctuations can damage pipeline connections, valves, and other components; long-term accumulation can also lead to fatigue cracks in the pipeline, or even pipe bursts, seriously threatening the normal operation of water conveyance projects and the water resource security of the receiving areas. Based on these issues, research into the transport characteristics of stagnant air masses is crucial.

[0004] Existing research methods include field monitoring and numerical simulation. While field monitoring can obtain the most realistic data, long-distance water pipelines are often buried deep underground, making air mass monitoring extremely difficult. Moreover, the pipelines are very long, the projects are large-scale, and monitoring points cannot be fully covered, making it difficult to capture the location of air masses, and the monitoring cost is high. Numerical simulation studies require extensive simplification and assumptions about complex actual conditions, which leads to a certain deviation between the simulation results and the actual situation, making it difficult to accurately reflect the movement patterns of air masses in the pipeline. Utility Model Content

[0005] To address the aforementioned shortcomings in the existing technology, the experimental device provided by this utility model for studying the transport characteristics of stagnant air masses in pressurized water pipelines aims to accurately simulate the real working conditions of long-distance pressurized water pipelines, providing a reliable platform for in-depth research on the transport characteristics of stagnant air masses.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0007] An experimental apparatus is provided for studying the transport characteristics of stagnant gas masses in pressurized water pipelines. It includes multiple test pipes connected in a ring loop by flanges, at least one of which is a transparent pipe. A camera is installed outside the transparent pipe to collect images of the fluid and stagnant gas masses inside the pipe. A power mechanism that extends partially into the pipe and drives the water flow inside the pipe is sealed on the test pipe. The test pipe is equipped with valves for injecting and discharging water, a gas injection valve, and an electromagnetic flowmeter for flow monitoring.

[0008] Furthermore, the transparent pipe can be multiple transparent pipe sections connected by flanges to form an inverted siphon pipe or a "U"-shaped pipe; or the transparent pipe can be a horizontal pipe or a gravity flow pressure pipe.

[0009] Furthermore, the power mechanism includes a motor and a frequency converter connected to the motor via a cable. The output shaft of the motor is connected to a power shaft that is sealed and rotatably connected to the test pipe or flange. A propeller is installed at the end of the power shaft located inside the test pipe.

[0010] Furthermore, the power shaft includes a connecting rod fixedly connected to the output shaft and a bushing sleeve fitted outside the connecting rod; one end of the bushing sleeve is fixed to the motor housing at the output shaft, and the other end passes into the test pipe and is sealed and fixedly connected to the test pipe; the propeller is installed at the end of the connecting rod located inside the test pipe.

[0011] Furthermore, a lubrication cavity is formed between the bushing and the connecting rod, and the lubrication cavity is filled with lubricating oil.

[0012] Furthermore, the test pipeline is equipped with a rectifier grid at the inlet end of the adjacent power mechanism output side and / or the transparent pipeline.

[0013] Furthermore, when the test pipeline is equipped with rectifier grids on both the output side of the power mechanism and the inlet end of the transparent pipeline, the length of the rectifier grid on the output side of the power mechanism is less than the length of the rectifier grid at the inlet end of the transparent pipeline.

[0014] Furthermore, the test pipeline has an exhaust port on the side adjacent to the power mechanism output, and an air injection valve is located at the inlet end of the transparent pipeline.

[0015] Furthermore, the test pipe at the power mechanism installation location is a conical pipe, with both ends of the conical pipe connected to the test pipe via flanges. The power mechanism enters the conical pipe through the flange at the large end of the conical pipe.

[0016] The beneficial effects of the present utility model are as follows: In this solution, the power mechanism drives the fluid in the annular circuit to move, so as to simulate the pressurized water conveyance in a long-distance water conveyance pipeline; the injection valve is used to inject gas to simulate the trapped air mass, and the camera device at the transparent pipeline can collect the movement of the trapped air mass. By changing the power of the power mechanism, parameters such as the movement trajectory and speed change of the trapped air mass under different water flow velocities can be obtained, which is convenient for researchers to accurately analyze the air mass transport characteristics through these data, provide technical support for the setting position of the air release valve on the long-distance water conveyance pipeline in specific projects, and improve the water conveyance efficiency and the operation safety of the project.

[0017] Precise control and monitoring: Through the precise control of the motor speed by the frequency converter and the high-precision monitoring of the water flow rate by the electromagnetic flowmeter, the precise regulation and data acquisition of the test conditions can be realized, providing reliable data guarantee for the in-depth study of the air mass transport characteristics.

[0018] Highly simulate the real working conditions: The transparent pipeline in the device can be adjusted according to various simulated complex terrains to flexibly simulate the long-distance pressurized water conveyance pipeline under various complex terrain conditions, covering different slopes and pipeline structures. Compared with the traditional test device, it can more truly reflect the transport situation of the air mass in the actual project.

[0019] Strong scalability: The test pipeline is connected by flanges, which is convenient for disassembly and replacement. Researchers can quickly adjust the device structure according to different research needs, expand the scope of test research, and improve the research efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of a test device for studying the transport characteristics of trapped air masses in a pressurized water conveyance pipeline.

[0021] Figure 2 It is a schematic diagram of various structures of the transparent pipeline. Among them, (a) is an inverted siphon pipeline, (b) is a "J" - shaped pipeline, (c) is a horizontal pipe, and (d) is a gravity flow pressure - bearing pipe.

[0022] Figure 3 It is a schematic cross - section diagram of the power shaft.

[0023] Among them, 1. Test pipeline; 2. Flange; 3. Camera device; 4. Power mechanism; 41. Motor; 42. Frequency converter; 43. Power shaft; 431. Connecting rod; 432. Bush; 433. Lubrication cavity; 44. Propeller; 5. Valve; 6. Injection valve; 7. Electromagnetic flowmeter; 8. Rectifying grid; 9. Exhaust hole. SPECIFIC EMBODIMENTS

[0024] The specific embodiments of this utility model are described below to enable those skilled in the art to understand this utility model. However, it should be understood that this utility model is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of this utility model as defined and determined by the appended claims, these changes are obvious. All utility model creations utilizing the concept of this utility model are within the scope of protection.

[0025] like Figure 1 As shown, this scheme provides an experimental device for studying the transport characteristics of stagnant gas masses in pressurized water pipelines. It includes multiple test pipes 1 connected by flanges 2 to form a loop. In this scheme, the test pipes 1 include straight pipes and arc-shaped pipes. The combination of these two types of pipes and flanges 2 forms a loop to simulate long-distance pressurized water pipelines.

[0026] At the same time, different types of test pipe sections, such as horizontal, downslope, and upslope, can be designed according to actual engineering needs to simulate water pipelines under various complex terrain conditions, providing convenience for studying the transport characteristics of air masses in different pipeline environments.

[0027] In this scheme, at least one test pipe 1 is preferably a transparent pipe. A camera device 3 is installed on the outside of the transparent pipe to collect images of the fluid and stagnant air masses inside the pipe. The camera device 3 is preferably a high-definition camera, and its collection range covers the entire transparent pipe as much as possible.

[0028] A power mechanism 4 is sealed and installed on the test pipe 1, which extends into the pipe to drive the water flow in the test pipe 1. In practice, the power mechanism 4 preferably includes a motor 41 and a frequency converter 42 connected to the motor 41 by a cable. The output shaft of the motor 41 is connected to a power shaft 43 that is sealed and rotatably connected to the test pipe 1 or the flange 2. A propeller 44 is installed at the end of the power shaft 43 located inside the test pipe 1.

[0029] The motor 41 is precisely controlled by the frequency converter 42, and the propeller 44 rotates at high speed driven by the motor 41, providing stable power to the water in the test pipeline 1. By changing the power of the motor 41 through the frequency converter 42, the rotational speed of the propeller 44 can be adjusted to obtain different water flow velocities, thus meeting the various flow rate requirements in the experiment.

[0030] The test pipeline 1 is equipped with valves 5 for injecting and discharging water, an injection valve 6 for injecting gas, and an electromagnetic flowmeter 7 for flow monitoring. This design preferably uses the injection valve 6 as a one-way valve to allow it to inject and retain gas masses and prevent backflow of water, ensuring a stable and reliable test process. The electromagnetic flowmeter 7 can monitor the water flow rate in real time, and the average flow velocity of the pipeline cross-section can be calculated based on the cross-sectional dimensions of the test pipeline 1.

[0031] This solution preferably selects the electromagnetic flowmeter 7 with high-precision flow measurement ability, which can monitor the change of water flow in real time, and the measurement accuracy can reach ±0.5%. It can provide accurate data support for studying the relationship between air mass transport and water flow, and help researchers accurately grasp the movement characteristics of air masses under different flow conditions.

[0032] As Figure 2 shown, during implementation, this solution preferably selects the transparent pipeline as multiple transparent pipe segments connected by flanges 2 to form an inverted siphon pipeline or a "zigzag" pipeline; or the transparent pipeline is a horizontal pipe or a gravity-flow pressure-bearing pipe. During the simulation test, different styles of transparent pipelines can be selected according to the simulated terrain conditions to ensure accurate simulation under different terrain conditions.

[0033] The inverted siphon is usually a downward concave inverted V-shaped structure, which is suitable for working conditions where the water conveyance line needs to cross obstacles such as deep valleys, rivers, and roads. The water flow passes through the downward concave pipeline, especially suitable for scenarios where the channel intersects with the obstacle and the water level difference is suitable.

[0034] The "zigzag" pipeline is usually a structure with multiple undulations, which is suitable for working conditions with complex terrain, multiple height changes, or the need to continuously cross multiple obstacles (such as multiple hills and multiple river valleys). Through the combination of rising and falling of the pipeline, it can flexibly adapt to the undulating terrain.

[0035] The horizontal pipe is suitable for working conditions with flat terrain and extremely small natural elevation differences. Due to the lack of natural head difference, it relies on a pumping station to pressurize and drive the water flow, which is common in scenarios such as long-distance water conveyance in cities, horizontal crossing of buildings, or dense pipelines.

[0036] The gravity-flow pressure-bearing pipe is usually a single-slope inclined structure, which is suitable for working conditions with significant natural elevation differences, that is, the water source is at a high place (such as a reservoir or a water source on a mountain top), and the water conveyance destination is at a low place. It uses the static water pressure formed by the terrain elevation difference to drive the water flow, without additional power, energy-saving and efficient, and suitable for long-distance gravity self-flow water conveyance.

[0037] As Figure 3 shown, the power shaft 43 includes a connecting rod 431 fixedly connected to the output shaft and a shaft sleeve 432 sleeved outside the connecting rod 431; one end of the shaft sleeve 432 is fixed on the housing of the motor 41 at the output shaft, and the other end penetrates into the test pipeline 1 and is fixedly connected to the test pipeline 1 in a sealed manner; the propeller 44 is installed at the end of the connecting rod 431 located inside the test pipeline 1. A lubrication cavity 433 is formed between the shaft sleeve 432 and the connecting rod 431, and the lubrication cavity 433 is filled with lubricating oil. The setting of the lubricating oil can effectively reduce the rotational friction and ensure the stable and efficient operation of the propeller 44.

[0038] Participate again Figure 1The test pipeline 1 is equipped with a flow rectifier 8 on the output side adjacent to the power mechanism 4 and / or at the inlet end of the transparent pipeline. The flow rectifier 8 can effectively eliminate water flow turbulence and make the water flow form a stable and uniform flow state.

[0039] In practice, this scheme preferably includes rectifier grids 8 on both the output side of the power mechanism 4 and the inlet end of the transparent pipe in the test pipe 1, with the grid length of the rectifier grid 8 on the output side of the power mechanism 4 being smaller than the grid length of the rectifier grid 8 at the inlet end of the transparent pipe. This arrangement ensures a more stable and uniform flow pattern at the point of entry into the transparent pipe, facilitating the acquisition of images of stagnant air masses.

[0040] In implementation, this scheme preferably provides an exhaust port 9 on the test pipe 1 near the output side of the power mechanism 4, and an air injection valve 6 is located at the inlet end of the transparent pipe. The test pipe 1 at the installation location of the power mechanism 4 is a conical pipe, and both ends of the conical pipe are connected to the test pipe 1 through flanges 2. The power mechanism 4 enters the interior of the conical pipe through the flange 2 at the large end of the conical pipe.

[0041] The operating procedure for the experimental apparatus provided in this solution is as follows:

[0042] Before the test begins, test pipes 1 of different shapes are selected according to the test objective, and the connection method and vent hole 9 of each test pipe 1 are adjusted. At the start of the test, water is injected through valve 5 to ensure that there is no stagnant air in the pipe. Then, motor 41 and frequency converter 42 are started to adjust the water flow to the predetermined speed and flow rate to propel the water flow in the test pipe 1. Frequency converter 42 adjusts the speed of motor 41 according to the preset test conditions to precisely control the water flow speed. The water flows into the transparent pipe after passing through the rectifier grid 8.

[0043] Gas is injected into the transparent pipe through the one-way gas injection valve 6, and the resulting stagnant gas cloud begins to move under the action of the water flow. The electromagnetic flowmeter 7 monitors the water flow rate in real time, and the average flow velocity of the pipe cross-section can be calculated based on the cross-sectional dimensions of the test pipe 1.

[0044] The movement of the stagnant air mass toward the exhaust port is observed using a high-definition camera 3, and the dynamic characteristics such as the movement trajectory and speed changes of the air mass under different water flow velocities are recorded. When the air mass moves to the position of the exhaust port 9, the air mass can be discharged through the exhaust port 9.

[0045] After the experiment, the motor 41 and related equipment were turned off. The researchers then analyzed the transport characteristics of the air mass by observing and recording parameters such as the trajectory and velocity changes of the air mass under different water flow velocities.

[0046] In summary, the experimental device provided in this scheme can systematically study the influence of different water flow conditions, pipeline structure and exhaust method on the trajectory of air mass movement, starting velocity, aggregation and breakup law, and thus provide key technical support for the optimized design and safe operation of long-distance pressurized water conveyance projects.

Claims

1. An experimental apparatus for studying the transport characteristics of stagnant gas masses in pressurized water pipelines, characterized in that, It includes multiple test pipes connected in a loop by flanges, at least one of which is a transparent pipe. A camera is installed on the outside of the transparent pipe to collect images of the fluid and stagnant air masses inside the pipe. A power mechanism that extends partially into the pipe and drives the water flow inside the pipe is sealed on the test pipe. The test pipe is equipped with valves for injecting and discharging water, a gas injection valve, and an electromagnetic flow meter for flow monitoring.

2. The test device of claim 1, wherein, The transparent pipe is formed by connecting multiple transparent pipe sections through flanges to form an inverted siphon pipe or a "U"-shaped pipe; or the transparent pipe is a horizontal pipe or a gravity flow pressure pipe.

3. The test device of claim 1, wherein, The power mechanism includes a motor and a frequency converter connected to the motor via a cable. The output shaft of the motor is connected to a power shaft that is sealed and rotatably connected to the test pipe or flange. A propeller is installed at the end of the power shaft located inside the test pipe.

4. The test device of claim 3, wherein The power shaft includes a connecting rod fixedly connected to the output shaft and a bushing sleeved outside the connecting rod; one end of the bushing sleeve is fixed to the motor housing at the output shaft, and the other end passes through the test pipe and is sealed and fixedly connected to the test pipe; the propeller is installed at the end of the connecting rod located inside the test pipe.

5. The test device of claim 4, wherein, A lubrication cavity is formed between the bushing and the connecting rod, and the lubrication cavity is filled with lubricating oil.

6. The test device of claim 1, wherein The test pipeline is equipped with a rectifier grid at the inlet end of the adjacent power mechanism output side and / or the transparent pipeline.

7. The test device of claim 6, wherein When the test pipeline is equipped with rectifier grids on both the output side of the power mechanism and the inlet end of the transparent pipeline, the length of the rectifier grid on the output side of the power mechanism is less than the length of the rectifier grid at the inlet end of the transparent pipeline.

8. The test device of claim 1, wherein, The test pipeline has an exhaust port on the side adjacent to the power mechanism output, and the air injection valve is located at the inlet end of the transparent pipeline.

9. The test device of any one of claims 1-8, wherein, The test pipe at the installation location of the power mechanism is a conical pipe. Both ends of the conical pipe are connected to the test pipe through flanges. The power mechanism passes through the flange at the large end of the conical pipe and enters the interior of the conical pipe.

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