A simulation experiment system for cavitation process in liquid low-pressure pipeline in high-altitude environment

Abstract

The application discloses a simulation experiment system of a cavitation process in a liquid low-pressure pipeline in a high-altitude environment, and belongs to the technical field of simulation experiment systems of cavitation processes in liquid low-pressure pipelines in high-altitude environments.The simulation experiment system comprises a pressure water storage tank, a vacuum pump, a cavitation process pipeline section system and a supporting platform; the vacuum pump is connected with the pressure water storage tank through a stainless steel air pipe; an anti-shock pressure gauge II is arranged between the stainless steel air pipe and the pressure water storage tank and used for monitoring the pressure in the pressure water storage tank; the supporting platform is located at the lower part of the cavitation process pipeline section system and provides support and fixation for the cavitation process pipeline section system.The simulation experiment system can provide a simulation experiment system of a cavitation process in equipment and pipelines in a high-altitude low-pressure environment of 2438m-5000m under normal pressure conditions in a low-altitude area, and can provide reasonable and accurate theoretical basis for the formation, development and collapse of the cavitation phenomenon in liquid pipelines and equipment under high-altitude low-pressure conditions.

Description

Technical Field

[0001] This invention relates to the field of cavitation simulation test technology, specifically to a simulation test system for the cavitation process in a low-pressure liquid pipeline in a high-altitude environment. Background Technology

[0002] High-altitude airports are characterized by low air pressure, large diurnal temperature variations, and strong radiation, which significantly impacts the performance of fire protection systems. Currently, relevant standards for high-altitude airports are still based on those for general airports, and no more suitable revision guidelines for high-altitude environments have been established domestically or internationally. my country has the world's largest number and highest altitude high-altitude airports, making it necessary to conduct in-depth and comprehensive verification and research on the operational performance of fire protection piping systems in low-pressure environments. Specifically, it needs to be clarified whether normal hydraulic transmission can be guaranteed in high-altitude, low-pressure environments and whether cavitation occurs. For example, Kangding Airport has a pressure of approximately -0.286 atmospheres (saturated vapor pressure), while Lhasa can reach -0.365 atmospheres. Under these environmental pressure conditions, the cavitation number of fire protection piping can reach approximately 0.6 to 6.0, meaning that cavitation is highly likely to occur. Once cavitation occurs, it can form a large number of bubbles, reducing pump efficiency, increasing noise and severe vibration, increasing gas content, and even potentially causing flow interruption and blade damage—one of the reasons for flow interruptions in fire protection piping at high-altitude airports.

[0003] Currently, there are no cavitation experiments and data acquisition devices designed for high-altitude pressure environments. Low-pressure pipeline systems suitable for high-altitude environments generally need to be built locally in high-altitude areas. Therefore, experiments can only be conducted in high-altitude laboratories, which is inefficient, wastes funds, and requires researchers to adapt to the low-pressure and hypoxic environment of high-altitude areas, which is not conducive to long-term scientific research activities.

[0004] In order to verify and study in detail the cavitation phenomenon generated during the transportation of liquids in high-altitude environments, including its formation, development and collapse, a simulation experimental system is urgently needed to conduct research experiments on the cavitation mechanism in an atmospheric pressure environment where the pipeline pressure can reach -0.4 atmospheres. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a simulation experimental system for the cavitation process in low-pressure liquid pipelines in high-altitude environments. Under normal pressure conditions in low-altitude areas, this system simulates the cavitation process in equipment and pipelines in high-altitude, low-pressure environments ranging from 2438m to 5000m. It provides a reasonable and accurate theoretical basis for the formation, development, and collapse of cavitation phenomena in liquid delivery pipelines and equipment under high-altitude, low-pressure conditions. It can simulate pressure conditions in different altitude plateaus or high-altitude environments according to requirements. Furthermore, the entire experimental device is a closed system that realizes water circulation, thus solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a simulation experimental system for the cavitation process in a low-pressure liquid pipeline in a high-altitude environment, the simulation experimental system comprising a pressure storage tank, a vacuum pump, a cavitation process pipeline system, and a support platform; the vacuum pump is connected to the pressure storage tank via a stainless steel gas pipe, and a shock-resistant pressure gauge II is also installed between the stainless steel gas pipe and the pressure storage tank for monitoring the pressure inside the pressure storage tank; the support platform is located at the lower part of the cavitation process pipeline system and provides support and fixation for the cavitation process pipeline system.

[0007] Preferably, the top of the pressure water storage tank is provided with a water inlet for filling the pressure water storage tank with water, and a return water inlet and an overflow return water inlet for receiving the return water and overflow water of the cavitation process pipeline system. The bottom side of the pressure water storage tank is provided with a pipeline inlet.

[0008] Preferably, the side of the pressure water storage tank is also provided with a level gauge for monitoring the liquid level of the pressure water storage tank. When the liquid level is too high and reaches the overflow level, the ball valve II provided on the pressure water storage tank is opened, and the excess water in the tank is discharged through the overflow pipe II connected to the ball valve II.

[0009] Preferably, the cavitation process piping system includes a water pump, a pipe compensator, an inlet pipe, a ball valve I, a manual regulating valve, a mass flow meter, a shock-resistant pressure gauge I, a thermometer, a cavitation pipe, a lift check valve, and a return pipe; the water pump is connected to the pipe inlet, enabling the cavitation process piping system to connect with the pressure storage tank.

[0010] Preferably, the water pump draws water from the pressure storage tank, which flows through the pipeline compensator and the inlet pipe, then through a ball valve I, a manual regulating valve, and a mass flow meter connected to one outlet of the tee, and finally reaches the cavitation pipe. After flowing out of the cavitation pipe, the water flows through the pipeline compensator, ball valve I, and a lift check valve to the return pipe, and then flows back to the pressure storage tank through the return port.

[0011] Preferably, both the front and rear sections of the cavitation pipe are equipped with shock-resistant pressure gauges I and thermometers to measure the pressure and temperature of the fluid at the inlet and outlet of the cavitation pipe.

[0012] Preferably, the mass flow meter is used to measure the mass flow rate of a liquid.

[0013] Preferably, the cavitation process pipeline system further includes a safety valve and an overflow pipe I; the water pump draws water from the pressure storage tank, flows through the pipeline compensator and the inlet pipe, then through the safety valve connected to the other outlet of the tee to the overflow pipe I, and finally flows back to the pressure storage tank through the overflow return port.

[0014] Preferably, the support platform includes a two-story steel frame platform, a sinkhole, a ground surface, drainage holes, a ladder, and a pipe support frame.

[0015] The second-floor steel frame platform is erected on the ground, the pipe support frame is set on the second-floor steel frame platform, and the cavitation process pipe section system is placed on the pipe support frame and is supported and fixed by the pipe support frame.

[0016] An escalator is also provided between the ground and the second-floor steel frame platform, which can be used to reach the second-floor steel frame platform;

[0017] The sinkhole is formed by a downward indentation from the ground, and the pressure water storage tank is placed inside the sinkhole to reduce the height of the entire simulation experiment system.

[0018] The bottom of the side wall of the sinkhole is provided with drainage holes, through which water in the sinkhole can be drained.

[0019] Preferably, the water pump is positioned horizontally at the bottom of the pressure storage tank; the cavitation pipe is positioned horizontally at the top of the pressure storage tank.

[0020] The beneficial effects of this invention are:

[0021] 1) On one hand, the present invention adds an air pipeline and a vacuum pump to the pressure water storage tank, and uses the vacuum pump to extract air from the tank to form a certain degree of vacuum, simulating atmospheric pressure at different altitudes; on the other hand, the power-providing water pump is arranged at the bottom of the pressure water storage tank, while the experimental research pipe section is raised to achieve a certain elevation difference between the upstream and downstream, ensuring the pressure environment required for the normal operation of the water pump.

[0022] 2) This invention can realize the simulation experiment research of cavitation process of low-pressure liquid pipeline in high-altitude airport environment under normal pressure conditions in low-altitude areas. This invention can provide a reasonable and accurate theoretical basis for the formation, development and collapse of cavitation phenomenon in liquid pipelines and equipment (various valves, reducers, bends, metering equipment, filter devices, nozzles, etc.) under high-altitude low-pressure conditions. It can simulate the pressure conditions of different altitude plateaus or high-altitude environments according to needs.

[0023] 3) This invention can realize the simulation experiment study of cavitation phenomenon caused by different liquid flow velocities (4-24m / s) in high-altitude airport environment. The lowest pressure of this invention can realize the pressure environment of high-altitude airport at an altitude of 5000 meters, which is higher than the current highest altitude airport (4411 meters). It can provide a basis for the application of low-pressure liquid pipeline transportation in airports at higher altitudes. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the simulation experimental system structure of the present invention;

[0025] Figure 2 A schematic diagram of the specific structure of the pressure water storage tank and vacuum pump;

[0026] Figure 3 This is a schematic diagram of the cavitation process pipe section system structure;

[0027] Figure 4 This is a schematic diagram of the supporting platform structure;

[0028] In the diagram, 11-Water pump, 12-Pipe compensator, 13-Inlet pipe, 14-Safety valve, 15-Overflow pipe I, 16-Ball valve I, 17-Manual regulating valve, 18-Mass flow meter, 19-Shock-resistant pressure gauge I, 110-Thermometer, 111-Cavitation pipe, 112-Lift check valve, 113-Return pipe, 21-Pipe inlet, 22-Vacuum pump, 23-Stainless steel gas pipe, 24-Pressure storage tank, 25-Level gauge, 26-Return port, 27-Overflow return port, 28-Shock-resistant pressure gauge II, 29-Inlet, 210-Ball valve II, 211-Overflow pipe II, 31-Second-floor steel frame platform, 32-Sunken pit, 33-Ground, 34-Drain hole, 35-Ladder, 36-Pipe support frame. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Please see Figures 1-4 This invention provides a technical solution: a simulation experimental system for the cavitation process in a low-pressure liquid pipeline in a high-altitude environment, the simulation experimental system as follows: Figure 1 As shown, it specifically includes a pressure water storage tank 24, a vacuum pump 22, a cavitation process piping system, and a support platform.

[0031] like Figure 2 As shown, the vacuum pump 22 is connected to the pressure storage tank 24 through the stainless steel air pipe 23. In order to achieve a low-pressure environment in the pressure storage tank 24, the vacuum pump 22 extracts the air from the pressure storage tank 24 through the stainless steel air pipe 23. A shock-resistant pressure gauge II 28 is also installed between the stainless steel air pipe and the pressure storage tank to monitor the pressure in the pressure storage tank.

[0032] The support platform is located at the bottom of the cavitation process pipe section system and provides support and fixation for the cavitation process pipe section system.

[0033] Furthermore, such as Figure 2As shown, the top of the pressure water storage tank 24 is provided with a water inlet 29 for filling the pressure water storage tank with water, and a return water inlet 26 and an overflow return water inlet 27 for receiving return water and overflow water from the cavitation process pipeline system. The bottom side of the pressure water storage tank is provided with a pipeline inlet 21.

[0034] The side of the pressure water tank is also equipped with a level gauge 25 for monitoring the liquid level of the pressure water tank. When the liquid level is too high and reaches the overflow level, the ball valve II 210 installed on the pressure water tank is opened, and the excess water in the tank is discharged through the overflow pipe II 211 connected to the ball valve II.

[0035] Furthermore, such as Figure 3 As shown, the cavitation process pipeline system includes a water pump 11, a pipeline compensator 12, an inlet pipe 13, a ball valve 116, a manual regulating valve 17, a mass flow meter 18, a shock-resistant pressure gauge 119, a thermometer 110, a cavitation pipe 111, a lift check valve 112, and a return pipe 113; the water pump 11 is connected to the pipeline inlet 21, realizing the connection between the cavitation process pipeline system and the pressure storage tank 24.

[0036] Water pump 11 draws water from pressure storage tank 24, which flows through pipeline compensator 12 and inlet pipe 13, and then through ball valve I16, manual regulating valve 17, and mass flow meter 18 connected to one outlet of the tee (entering the main pipeline of the cavitation process) to reach cavitation pipe 111. After flowing out of cavitation pipe 111, it flows through pipeline compensator 12, ball valve I16, and lift check valve 112 to reach return pipe 113, and then flows back to pressure storage tank 24 through return port 26.

[0037] The lift check valve 112 is used to prevent downstream backflow of liquid to the test section.

[0038] The ball valve is used to open and close the flow of liquids upstream and downstream of the pipeline, and the manual regulating valve is used to manually regulate the pipeline pressure, thereby achieving the regulation of the environmental pressure in the experimental section.

[0039] Furthermore, shock-resistant pressure gauges I19 and thermometers 110 are arranged in both the front and rear sections of the cavitation pipe 111 to measure the pressure and temperature of the fluid at the inlet and outlet of the cavitation pipe 111.

[0040] The mass flow meter 18 is used to measure the mass flow rate of liquids; the pipe compensator can meet the experimental research needs of test specimens of different lengths.

[0041] Furthermore, such as Figure 3As shown, the cavitation process pipeline system also includes a safety valve 14 and an overflow pipe I15; the water pump 11 draws water from the pressure storage tank 24, which flows through the pipeline compensator 12 and the inlet pipe 13, and then through the safety valve 14 connected to the other outlet of the tee to the overflow pipe I15, and finally flows back to the pressure storage tank 24 through the overflow return port 27.

[0042] Safety valve 14 is used to protect the pipeline from transient high pressure limits caused by unstable flow such as water hammer; overflow pipe is used to prevent pressure rise after the water tank is full.

[0043] Furthermore, such as Figure 4 As shown, the support platform includes a two-story steel frame platform 31, a sinkhole 32, a ground surface 33, a drainage hole 34, a ladder 35, and a pipe support frame 36.

[0044] The second-level steel frame platform 31 is erected on the ground 33. The pipe support frame 36 is set on the second-level steel frame platform 31. The cavitation process pipe section system is placed on the pipe support frame 36 and is supported and fixed by the pipe support frame.

[0045] An escalator 35 is also provided between the ground and the second-floor steel frame platform, allowing experimental personnel to access the second-floor steel frame platform via the escalator.

[0046] In addition, in order to reduce the overall height of the experimental system, a sinkhole 32 is designed in this system. The sinkhole 32 is set to be recessed downward from the ground, specifically 0.3-0.5 meters. The pressure water storage tank 24 is set in the sinkhole 32, which helps to reduce the height of the entire simulation experimental system.

[0047] The water stored in the pressure storage tank 24 can be discharged into the sinkhole 32 through the bottom valve, and the water discharged from the overflow pipe II 211 can also be directly discharged into the sinkhole 32.

[0048] Furthermore, a drainage hole 34 is provided at the bottom of the side wall of the sinkhole 32, through which water in the sinkhole can be discharged.

[0049] The water pump 11 is positioned horizontally flush with the bottom of the pressure storage tank 24; the cavitation pipe 111 is positioned horizontally flush with the top of the pressure storage tank 24. This elevates the experimental section of the cavitation process, creating a certain elevation difference between the upstream and downstream sides, ensuring the pressure environment required for the normal operation of the water pump.

[0050] The specific operating steps for conducting experiments using the simulation experimental system of this invention are as follows:

[0051] (1) Close all valves in the experimental system, open valve 210, inject tap water through water inlet 29, and fill pressure storage tank 24 with water to a liquid level of 2.5 to 3.0 meters. During the cavitation experiment, ensure that the liquid level is greater than 2.5 meters to provide stable static pressure for the submersible pump.

[0052] (2) Close valve 210 to ensure the airtightness of the water tank, open the ball valve on the gas pipeline, and start vacuum pump 22;

[0053] (3) When the specified pressure is reached, close the gas pipeline ball valve and stop the vacuum pump;

[0054] (4) Open ball valve 16, start water pump 11, and set water pump flow rate;

[0055] (5) Adjust the pressure regulating valve until the pressure in the cavitation test section reaches the specified value;

[0056] (6) Stop the pump, close all valves, and slowly open valve 210, keeping it at a small opening.

[0057] In the high-altitude cavitation simulation experiment, the pressure storage tank 24 acts as a pressure vessel (negative pressure). Its main functions are water storage, low pressure for the vacuum pump, and providing a static pressure of 0.25–3.0 bar for the submersible pump to ensure its normal operation. The water pump 11 delivers water from the pressure storage tank 24 to the cavitation process research experimental section. The high-speed flowing water generates cavitation in the cavitation pipe 111, forming water vapor. After cavitation, the water carrying air bubbles flows back to the water tank through the return water pipe. After automatic gas-liquid separation in the water tank, the vacuum pump removes the air from the tank, creating a vacuum environment.

[0058] This invention enables the simulation experiment of cavitation process in low-pressure liquid pipelines in high-altitude airport environments under normal pressure conditions in low-altitude areas. This invention can provide a reasonable and accurate theoretical basis for the formation, development and collapse of cavitation phenomena in liquid delivery pipelines and equipment (various valves, reducers, bends, metering equipment, filters, nozzles, etc.) under high-altitude and low-pressure conditions. It can simulate pressure conditions in different altitude plateau or high-altitude environments as needed.

[0059] This invention enables the simulation experiment study of cavitation phenomena caused by different liquid flow velocities (4-24 m / s) in high-altitude airport environments. The lowest pressure of this invention can achieve the pressure environment of a high-altitude airport at an altitude of 5000 meters, which is higher than the current highest altitude airport (4411 meters). This invention can provide a basis for the application of low-pressure liquid pipeline transportation in airports at higher altitudes.

[0060] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A simulation experimental system for the cavitation process in a low-pressure liquid pipeline in a high-altitude environment, characterized in that, The simulation experiment system includes a pressure water tank (24), a vacuum pump (22), a cavitation process pipe system, and a support platform; the vacuum pump (22) is connected to the pressure water tank (24) through a stainless steel gas pipe (23), and a shock-resistant pressure gauge II (28) is also installed between the stainless steel gas pipe and the pressure water tank to monitor the pressure in the pressure water tank; the support platform is located at the bottom of the cavitation process pipe system and provides support and fixation for the cavitation process pipe system. The pressure water storage tank (24) is provided with a water inlet (29) for filling the pressure water storage tank with water, and a return water inlet (26) and an overflow return water inlet (27) for receiving the return water and overflow water of the cavitation process pipeline system. The bottom side of the pressure water storage tank is provided with a pipeline inlet (21).

2. The simulation experimental system for cavitation process in a low-pressure liquid pipeline in a high-altitude environment according to claim 1, characterized in that: The side of the pressure water tank is also equipped with a level gauge (25) for monitoring the liquid level of the pressure water tank. When the liquid level is too high and reaches the overflow level, the ball valve II (210) installed on the pressure water tank is opened, and the excess water in the tank is discharged through the overflow pipe II (211) connected to the ball valve II.

3. The simulation experimental system for cavitation process in a low-pressure liquid pipeline in a high-altitude environment according to claim 1, characterized in that: The cavitation process pipeline system includes a water pump (11), a pipeline compensator (12), an inlet pipe (13), a ball valve I (16), a manual regulating valve (17), a mass flow meter (18), a shock-resistant pressure gauge I (19), a thermometer (110), a cavitation pipe (111), a lift check valve (112), and a return pipe (113); the water pump (11) is connected to the pipeline inlet (21) to realize the connection between the cavitation process pipeline system and the pressure storage tank (24).

4. The simulation experimental system for cavitation process in a low-pressure liquid pipeline in a high-altitude environment according to claim 3, characterized in that: The water pump (11) draws water from the pressure storage tank (24) and flows through the pipeline compensator (12) and the inlet pipe (13). After passing through the ball valve I (16), manual regulating valve (17), and mass flow meter (18) connected to one outlet of the tee, the water reaches the cavitation pipe (111). After flowing out of the cavitation pipe (111), the water flows through the pipeline compensator (12), ball valve I (16), and lift check valve (112) to the return pipe (113), and then flows back to the pressure storage tank (24) through the return port (26).

5. The simulation experimental system for cavitation process in a low-pressure liquid pipeline in a high-altitude environment according to claim 4, characterized in that: The cavitation pipe (111) is equipped with shock-resistant pressure gauges I (19) and thermometers (110) in both the front and rear pipe sections to measure the pressure and temperature of the fluid at the inlet and outlet of the cavitation pipe (111).

6. The simulation experimental system for cavitation process in a low-pressure liquid pipeline in a high-altitude environment according to claim 4, characterized in that: The mass flow meter (18) is used to measure the mass flow rate of liquid.

7. The simulation experimental system for cavitation process in a low-pressure liquid pipeline in a high-altitude environment according to claim 1 or 3, characterized in that: The cavitation process pipeline system also includes a safety valve (14) and an overflow pipe I (15); the water pump (11) draws water from the pressure storage tank (24) through the pipeline compensator (12) and the inlet pipe (13), and then through the safety valve (14) connected to the other outlet of the tee to reach the overflow pipe I (15), and finally flows back to the pressure storage tank (24) through the overflow return port (27).

8. The simulation experimental system for cavitation process in a low-pressure liquid pipeline in a high-altitude environment according to claim 1, characterized in that: The support platform includes a two-story steel frame platform (31), a sinkhole (32), a ground (33), a drainage hole (34), a ladder (35), and a pipe support frame (36). The second-floor steel frame platform (31) is erected on the ground (33), the pipe support frame (36) is set on the second-floor steel frame platform (31), the cavitation process pipe section system is placed on the pipe support frame (36), and is supported and fixed by the pipe support frame; An escalator (35) is also provided between the ground and the second-floor steel frame platform, which can be used to reach the second-floor steel frame platform. The sinkhole (32) is set by a downward indentation from the ground, and the pressure water storage tank (24) is set in the sinkhole (32) to reduce the height of the entire simulation experiment system; The bottom of the side wall of the sinkhole (32) is provided with a drainage hole (34), through which water in the sinkhole can be discharged.

9. The simulation experimental system for cavitation process in a low-pressure liquid pipeline in a high-altitude environment according to claim 3, characterized in that: The water pump (11) is installed at the bottom of the pressure water tank (24) at a horizontal level; the cavitation pipe (111) is installed at the top of the pressure water tank (24) at a horizontal level.

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