A measurement method for liquid carrying by spiral air flow in a U-shaped tube

Abstract

The present invention provides a method for measuring liquid entrainment by spiral gas flow in a U-shaped tube, which comprises the following steps: capturing gas-liquid phase motion images under different working conditions in the U-shaped tube; obtaining the binarized gas-liquid phase distribution pictures in the U-shaped tube; calculating the average height of all column shadows in the cell; calculating the average projected liquid film height in the cell and defining the average projected gas holdup; describing the variation of the liquid film height and gas holdup with time in gas-liquid flow, and analyzing the fluctuation characteristics of the liquid film height and gas holdup with time; measuring the residual liquid film height and calculating the dimensionless height; when the gas flow rate can carry away all the accumulated liquid, recording the gas flow rate and defining the corresponding gas flow rate as the critical liquid-carrying gas volume, and calculating the critical liquid-carrying gas velocity according to the critical liquid-carrying gas volume. The present invention can comprehensively analyze the liquid-carrying effect, flow pattern, liquid film and gas holdup law, and reveals the liquid-carrying effect and working mechanism of spiral gas flow in undulating pipelines.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid mechanics, and more specifically, to a method for measuring the liquid carrying capacity of spiral air flow in a U-shaped tube. Background Art

[0002] In recent years, with the continuous expansion of the demand for clean energy, more and more natural gas has been used. The most common method for natural gas transportation is pipeline transportation. Pipeline transportation has the characteristics of continuous high efficiency, safety and stability, and plays an important role in the development and transportation of natural gas resources. During the transportation process, liquid accumulation will occur in the pipeline due to environmental and other factors, especially at the position of undulating pipelines. The generation of liquid accumulation will affect the transportation of natural gas and even form natural gas hydrates, thus blocking the pipeline and endangering the pipeline safety. Therefore, it is necessary to carry away the liquid accumulation to improve the transportation efficiency. Since the spiral flow has both axial and tangential velocity components, and the effect of the tangential velocity cannot be ignored, it can be applied to the field of liquid carrying in undulating pipelines to reduce pipeline blockage and ensure the safe transportation of oil and gas.

[0003] After retrieval, the Chinese invention patent application with the patent application number CN2019111738337 discloses an experimental device for studying liquid carrying in undulating pipelines, which can realize the study of the flow law and pressure drop characteristics of liquid carrying in undulating pipelines under laboratory conditions, conduct experimental verification on the numerical simulation results, improve the flow mechanism of gas carrying liquid, and at the same time study the gas liquid carrying capacity in combination with flow patterns and pressure drops.

[0004] However, the above-mentioned existing experimental device for studying liquid carrying in undulating pipelines does not reveal the effect of spiral air flow carrying liquid in undulating pipelines by comprehensively analyzing the liquid carrying effect, flow pattern, liquid film and gas holdup law, and thus needs to be improved. Summary of the Invention

[0005] Based on this, in order to solve the problem that the existing experimental device for studying liquid carrying in undulating pipelines does not reveal the effect of spiral air flow carrying liquid in undulating pipelines by comprehensively analyzing the liquid carrying effect, flow pattern, liquid film and gas holdup law, the present invention provides a method for measuring the liquid carrying capacity of spiral air flow in a U-shaped tube, and its specific technical solution is as follows:

[0006] A method for measuring the liquid carrying capacity of spiral air flow in a U-shaped tube, which includes the following steps:

[0007] Capture the gas-liquid phase motion images under different working conditions in the U-shaped tube;

[0008] Process the gas-liquid phase motion images to obtain the binary gas-liquid phase distribution pictures in the U-shaped tube;

[0009] Based on the binary image of the gas-liquid phase distribution in the U-shaped tube, a finite volume is selected in the cross-section of the U-shaped tube. By traversing the pixels, i columns of pixels perpendicular to the flow direction are selected from left to right, and the average height of the shadows in each column of pixels is calculated. The average height is used as the liquid film height of this column, and the average height h(i) of the shadows in all columns within the cell is calculated;

[0010] Based on the average height h(i) of all columns of shadows, according to the formula the average projected liquid film height h within the cell is calculated cl , and the average projected gas holdup is defined where r is the radius of the U-shaped tube;

[0011] Statistical analysis methods are used to describe the liquid film height h cl and gas holdup α cv in the gas-liquid flow as they change with time. Based on the time trajectory and probability density function, the fluctuation characteristics of the liquid film height h cl and gas holdup α cv as they change with time are analyzed. According to the formula the probability density function of the liquid film fluctuation signal is calculated;

[0012] The size of the gas flow rate introduced is fixed. When the liquid accumulation in the U-shaped tube remains unchanged, the gas supply is stopped. After the liquid accumulation in the U-shaped tube drops, the residual liquid film height h1 is measured. Through the formula the dimensionless height H' is calculated, where D is the inner diameter of the U-shaped tube and h2 is the vertical height of the U-shaped tube;

[0013] The gas flow rate is increased from small to large. When the gas flow rate can carry away all the liquid accumulation, the gas flow rate is recorded and the corresponding gas flow rate is defined as the critical liquid-carrying gas volume. The critical liquid-carrying gas velocity u' is calculated according to the critical liquid-carrying gas volume sg .

[0014] The measurement method of liquid carrying by spiral gas flow in the U-shaped tube first captures the gas-liquid phase motion images under different working conditions in the U-shaped tube to obtain the binary image of the gas-liquid phase distribution in the U-shaped tube. Then, based on the binary image of the gas-liquid phase distribution in the U-shaped tube, the average projected gas holdup is obtained. Finally, the changes of the liquid film height h cl and gas holdup α cv with time, the liquid film height h cl and gas holdup α cvThe fluctuation characteristics over time are utilized to achieve non-invasive measurement of the variation laws of the liquid film height and gas holdup in the U-shaped tube over time. It is possible to comprehensively analyze the liquid carrying effect, flow pattern, liquid film, and gas holdup laws, revealing the liquid carrying effect and working mechanism of the helical gas flow in the undulating pipeline, and solving the problem that the existing experimental devices for studying liquid carrying in undulating pipelines do not reveal the liquid carrying effect of the helical gas flow in the undulating pipeline by comprehensively analyzing the liquid carrying effect, flow pattern, liquid film, and gas holdup laws.

[0015] Furthermore, the method for measuring liquid carrying by the helical gas flow in the U-shaped tube further includes the following steps:

[0016] Build a visualization experimental section of the helical gas flow in the U-shaped tube, where the visualization experimental section includes a horizontal inlet fluid pipeline, a U-shaped tube, and a horizontal outlet fluid pipeline;

[0017] Fix and install the swirl generator structure in the horizontal inlet fluid pipeline, and connect the horizontal inlet fluid pipeline to the gas supply system to initiate the helical gas flow;

[0018] Inject water into the U-shaped tube through the water injection hole as accumulated liquid, and adjust the gas phase flow rate from low to high to change the gas phase flow rate and the height of the accumulated liquid to obtain different working conditions.

[0019] Furthermore, the method for measuring liquid carrying by the helical gas flow in the U-shaped tube further includes the following steps:

[0020] According to whether the helical gas flow can completely carry the accumulated liquid, different liquid carrying parameters are used to measure the liquid carrying capacity of the helical gas flow;

[0021] When the accumulated liquid cannot be completely carried by the helical gas flow, the dimensionless height H' is used to measure the liquid carrying capacity;

[0022] When the accumulated liquid can be completely carried by the helical gas flow, the critical liquid carrying gas velocity u’ sg is used to measure the liquid carrying capacity.

[0023] Furthermore, the method for measuring liquid carrying by the helical gas flow in the U-shaped tube further includes the following steps:

[0024] Provide a transparent water tank;

[0025] Place the U-shaped tube into the transparent water tank, inject water into the transparent water tank and make the liquid level submerge the lower end of the U-shaped tube.

[0026] Furthermore, the specific method for capturing the gas-liquid phase motion images under different working conditions in the U-shaped tube includes the following steps:

[0027] Set a high-speed camera on one side of the U-shaped tube;

[0028] Set a light source on the other side of the U-shaped tube and place white rice paper between the light source and the U-shaped tube;

[0029] Capture the gas-liquid phase motion images in the U-shaped tube under different working conditions through a high-speed camera.

[0030] A computer-readable storage medium stores a computer program, which implements the method for measuring the liquid carrying capacity of the spiral gas flow in the U-shaped tube when the computer program is executed by a processor. Description of the Drawings

[0031] The present invention can be further understood from the following description in conjunction with the drawings. The components in the drawings are not necessarily drawn to scale, but the emphasis is on showing the principles of the embodiments. In different views, the same reference numerals designate corresponding parts.

[0032] Figure 1 is the overall flow schematic diagram of a method for measuring the liquid carrying capacity of the spiral gas flow in a U-shaped tube in an embodiment of the present invention;

[0033] Figure 2 is the schematic diagram of a cell with a finite volume on the cross-section of the U-shaped tube in an embodiment of the present invention;

[0034] Figure 3 is the schematic diagram of the change effect of the liquid film height over time at a cell on a cross-section of the U-shaped tube in an embodiment of the present invention;

[0035] Figure 4 is the schematic diagram of the change effect of the gas holdup over time at a cell on a cross-section of the U-shaped tube in an embodiment of the present invention;

[0036] Figure 5 is the PDF curve diagram of the liquid film height at a cell on a cross-section of the U-shaped tube in an embodiment of the present invention;

[0037] Figure 6 is the PDF curve diagram of the gas holdup at a cell on a cross-section of the U-shaped tube in an embodiment of the present invention;

[0038] Figure 7 is the schematic diagram of the meanings of D, h1, and h2 in the dimensionless number calculation formula in an embodiment of the present invention;

[0039] Figure 8 is the schematic diagram of the comparison effect of the liquid carrying capacities of the non-spiral gas flow without a swirl generator and the spiral gas flow with a swirl generator in the U-shaped tube under different flow patterns in an embodiment of the present invention. Detailed Embodiments

[0040] In order to make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with its embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not limit the protection scope of the present invention.

[0041] It should be noted that when an element is referred to as "fixed to" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this invention belongs. The terms used in the description of this invention herein are only for the purpose of describing specific embodiments and are not intended to limit this invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0043] In this invention, the so-called "first" and "second" do not represent specific quantities and orders, but are only used for name distinction.

[0044] A measurement method for spiral gas flow carrying liquid in a U-shaped tube in an embodiment of this invention, as Figure 1 shown, includes the following steps:

[0045] S1. Capture the gas-liquid phase movement images under different working conditions in the U-shaped tube.

[0046] Specifically, the specific method for capturing the gas-liquid phase movement images under different working conditions in the U-shaped tube includes the following steps:

[0047] S10. Set a high-speed camera on one side of the U-shaped tube.

[0048] S11. Set a light source on the other side of the U-shaped tube and place white rice paper between the light source and the U-shaped tube.

[0049] S12. Capture the gas-liquid phase movement images under different working conditions in the U-shaped tube through the high-speed camera.

[0050] This embodiment uses backlight illumination and collects the gas-liquid phase movement images under different working conditions in the U-shaped tube through a high-speed camera.

[0051] Optionally, the light source is an LED light source and is located directly behind the U-shaped tube, the high-speed camera is located directly in front of the U-shaped tube, and the white rice paper has high light transmittance.

[0052] By placing white rice paper between the light source and the U-shaped tube, the light shining on the U-shaped tube can be made more uniform, improving the shooting effect of the gas-liquid phase movement images under different working conditions in the U-shaped tube.

[0053] S2. Process the gas-liquid phase motion image to obtain the binary image of the gas-liquid phase distribution inside the U-shaped tube.

[0054] Specifically, the processing of the gas-liquid phase motion image includes, but is not limited to, cropping, edge extraction, contrast enhancement, noise reduction, and binarization processing, etc.

[0055] Preferably, an image processing program can be developed using MATLAB software to extract the image processing program for the liquid thickness inside the U-shaped tube.

[0056] Specifically, first, use the Imcrop function to crop the rectangular part of the image with a width of 100 pixels. Second, in order to obtain a clear image, comprehensively use morphological processing methods (imtophat and imbothat functions) to reduce the influence of uneven illumination. Finally, in order to reduce noise, adopt a median filtering method with a sliding window of 3×3 (medfi lter2 function), and use histogram adjustment (imadjust function) to improve the image contrast.

[0057] Since how to develop an image processing program using MATLAB software belongs to the conventional technical means in this field, it will not be elaborated here.

[0058] S3, as Figure 3 shown, based on the binary image of the gas-liquid phase distribution inside the U-shaped tube, select a finite volume in the cross-section of the U-shaped tube. By traversing the pixels, select i columns of pixels perpendicular to the flow direction from left to right, calculate the average height of the shadows in each column of pixels and use the average height as the liquid film height of this column, and calculate the average height h(i) of the shadows in all columns within the cell.

[0059] Specifically, the length of the finite volume = 165 pixels, and the width = a cell of 100 pixels, as Figure 2 shown as A-A in

[0060] S4, based on the average height h(i) of all columns of shadows, calculate the average projected liquid film height h within the cell according to the formula , and define the average projected gas holdup cl , where r is the radius of the U-shaped tube.

[0061] S5, use statistical analysis methods to describe the variation of the liquid film height h cl and the gas holdup α cv with time, analyze the fluctuation characteristics of the liquid film height h cl and the gas holdup α cv with time based on the time trajectory and the probability density function (PDF), and according to the formula Calculate the probability density function of the liquid film fluctuation signal.

[0062] Specifically, the liquid film height h in the cell of the U-tube cl changes with time as Figure 3 shown, and the gas holdup α in the cell cv changes with time as Figure 4 shown.

[0063] The liquid film height h in the cell cl and the gas holdup α cv fluctuation characteristics with time are respectively as Figure 5 and Figure 6 shown.

[0064] S6. Fix the size of the gas phase flow rate introduced. When the liquid accumulation in the U-tube remains unchanged, that is, when the water volume in the water bucket collecting the liquid carried at the end of the pipeline no longer increases, it is considered that the flow is stable. At this time, stop the ventilation. Wait for the liquid accumulation in the U-tube to fall back, measure the residual liquid film height h1, and calculate the dimensionless height H' through the formula where, as Figure 7 shown, D is the inner diameter of the U-tube, and h2 is the vertical height of the U-tube.

[0065] S7. Increase the gas phase flow rate from small to large. When the gas phase flow rate can carry away all the liquid accumulation, record the gas phase flow rate and define the corresponding gas phase flow rate as the critical liquid-carrying gas volume. Calculate the critical liquid-carrying gas velocity u' according to the critical liquid-carrying gas volume sg .

[0066] The measurement method of liquid carrying by spiral gas flow in the U-tube first captures the gas-liquid phase motion images under different working conditions in the U-tube, obtains the binary gas-liquid phase distribution picture in the U-tube, then based on the binary gas-liquid phase distribution picture in the U-tube, obtains the average projected gas holdup, and finally describes the changes of the liquid film height h cl and the gas holdup α cv with time, the fluctuation characteristics of the liquid film height h cl and the gas holdup α cv with time, realizes the non-invasive measurement of the change law of the liquid film height and gas holdup in the U-tube with time, comprehensively analyzes the liquid-carrying effect, flow pattern, liquid film and gas holdup law, reveals the liquid-carrying effect and working mechanism of the spiral gas flow in the undulating pipeline, and solves the problem that the existing experimental device for studying liquid carrying in the undulating pipeline does not reveal the liquid-carrying effect of the spiral gas flow in the undulating pipeline by comprehensively analyzing the liquid-carrying effect, flow pattern, liquid film and gas holdup law.

[0067] In one embodiment, the measurement method of liquid carrying by spiral gas flow in the U-tube further includes the following steps:

[0068] First step: Build a visualization experimental section of the spiral airflow in the U-shaped tube. The visualization experimental section includes a horizontal fluid inlet pipe, a U-shaped tube, and a horizontal fluid outlet pipe.

[0069] Second step: Fix and install the swirl generator structure in the horizontal fluid inlet pipe, and connect the horizontal fluid inlet pipe to the gas supply system to initiate the spiral airflow.

[0070] Third step: Inject water into the U-shaped tube from the water injection hole as the accumulated liquid, and adjust the gas phase flow rate from low to high, changing the gas phase flow rate and the height of the accumulated liquid to obtain different working conditions.

[0071] That is to say, before capturing the gas-liquid phase movement images under different working conditions in the U-shaped tube, the above three steps are first executed.

[0072] The visualization experimental section is made of transparent organic glass. Among them, the U-shaped tube is used to simulate the undulating pipeline, including a descending section and an upwardly inclined section. A water injection hole is opened in front of the downwardly inclined section of the U-shaped tube, and a water bucket for collecting the liquid carried by the gas is provided at the end of the horizontal fluid outlet pipe.

[0073] The gas supply system includes an air compressor, a gas flow meter, a valve, and a connecting pipeline. The valve and the gas flow meter are installed on the connecting pipeline, and the air compressor is connected to the horizontal fluid inlet pipe through the connecting pipeline.

[0074] Use the U-shaped tube to simulate the undulating pipeline, and capture the gas-liquid phase movement images under different working conditions in the U-shaped tube. Furthermore, obtain the flow patterns, gas-liquid phase distributions, and pressures in the downwardly inclined section and the upwardly inclined section of the undulating pipeline. Couple the flow patterns representing the gas-liquid phase movement in the U-shaped tube with the liquid carrying effect for analysis and research, which is convenient for obtaining the mechanism and applicable conditions of the spiral airflow carrying liquid in the undulating pipeline, and can be applied in the monitoring of oil and gas pipeline transportation to reduce pipeline blockage and ensure the safe transportation of oil and gas.

[0075] In one embodiment, the method for measuring the liquid carrying of the spiral airflow in the U-shaped tube further includes the following steps:

[0076] According to whether the spiral airflow can completely carry the accumulated liquid, different liquid carrying parameters are used to measure the liquid carrying ability of the spiral airflow.

[0077] When the accumulated liquid cannot be completely carried by the spiral airflow, the dimensionless height H' is used to measure the liquid carrying ability.

[0078] When the accumulated liquid can be completely carried by the spiral airflow, the critical liquid carrying gas velocity u’ sg is used to measure the liquid carrying ability.

[0079] Among them, the smaller the value of the dimensionless height H', the stronger the liquid carrying ability of the spiral airflow; the smaller the value of the critical liquid carrying gas velocity u’ sg the stronger the liquid carrying ability of the spiral airflow.

[0080] In one embodiment, the method for measuring the liquid carrying capacity of the spiral air flow in the U-shaped tube further comprises the following steps:

[0081] Provide a transparent water tank;

[0082] Place the U-shaped tube into the transparent water tank, inject water into the transparent water tank and make the liquid level submerge the lower end of the U-shaped tube.

[0083] By placing the U-shaped tube into the transparent water tank and making the liquid level in the water tank submerge the lower end of the U-shaped tube, the measurement error caused by the circular tube can be eliminated.

[0084] In one embodiment, the method for measuring the liquid carrying capacity of the spiral air flow in the U-shaped tube further comprises the following steps:

[0085] Obtain the liquid carrying capacity of the spiral air flow and the non-spiral air flow in the U-shaped tube, and obtain the gas-liquid two-phase flow pattern in the U-shaped tube under the action of the spiral air flow and the non-spiral air flow;

[0086] Couple the liquid carrying capacity of the spiral air flow and the non-spiral air flow in the U-shaped tube and the corresponding gas-liquid two-phase flow patterns respectively;

[0087] Obtain the liquid film height h cl and the gas holdup α cv The fluctuation characteristics over time, and compare and analyze the liquid carrying mechanism of the spiral air flow in the U-shaped tube.

[0088] As Figure 8 shown, it is a schematic diagram of the liquid carrying capacity effect of the non-spiral air flow without a swirl generator and the spiral air flow after installing a swirl generator in the U-shaped tube under different flow patterns.

[0089] Combined with Figure 8 it can be known that by comparing and analyzing the liquid carrying capacity of the spiral air flow and the non-spiral air flow in the U-shaped tube, the liquid carrying mechanism and the liquid carrying effect of the spiral air flow in the U-shaped tube can be observed and analyzed more intuitively.

[0090] In one embodiment, a computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the method for measuring the liquid carrying capacity of the spiral air flow in the U-shaped tube.

[0091] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0092] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A method for measuring liquid entrainment by spiral gas flow in a U-shaped tube, characterized in that, the method for measuring liquid entrainment by spiral gas flow in the U-shaped tube comprises the following steps: Capture the gas-liquid phase motion images under different working conditions in the U-shaped tube; Process the gas-liquid phase motion images to obtain the binary image of the gas-liquid phase distribution in the U-shaped tube; Based on the binary image of the gas-liquid phase distribution in the U-shaped tube, select a finite volume in the cross-section of the U-shaped tube. By traversing the pixels, select i columns of pixels perpendicular to the flow direction from left to right, calculate the average height of the shadows in each column of pixels and use the average height as the liquid film height of this column, and calculate the average height h(i) of all column shadows in the cell; Based on the average height h(i) of all column shadows, according to the formula the average projected liquid film height h within the cell is calculated cl , and the average projected gas holdup is defined where r is the radius of the U-tube; Use statistical analysis methods to describe the liquid film height h cl and gas holdup α cv in gas-liquid flow and their variations over time. Analyze the fluctuation characteristics of the liquid film height h cl and gas holdup α cv over time based on time trajectories and probability density functions. Calculate the probability density function of the liquid film fluctuation signal according to the formula ; Fix the magnitude of the gas flow rate introduced. When the liquid accumulation in the U-shaped tube remains unchanged, stop the gas supply. After the liquid accumulation in the U-shaped tube drops back, measure the height h1 of the residual liquid film. Calculate the dimensionless height H' through the formula where D is the inner diameter of the U-shaped tube and h2 is the vertical height of the U-shaped tube; Increase the gas phase flow rate from small to large. When the gas phase flow rate can carry away all the liquid accumulation, record the gas phase flow rate and define the corresponding gas phase flow rate as the critical liquid-carrying gas volume. Calculate the critical liquid-carrying gas velocity u' based on the critical liquid-carrying gas volume sg .

2. The method for measuring liquid entrainment by spiral gas flow in a U-shaped tube according to claim 1, characterized in that, the method for measuring liquid entrainment by spiral gas flow in the U-shaped tube further comprises the following steps: Build a visualization experimental section of the spiral gas flow in the U-shaped tube. The visualization experimental section includes a horizontal inlet fluid pipeline, a U-shaped tube and a horizontal outlet fluid pipeline; Fix the swirl generator structure in the horizontal inlet fluid pipeline and connect the horizontal inlet fluid pipeline to the gas supply system to initiate the spiral gas flow; Inject water into the U-shaped tube from the water injection hole as the accumulated liquid, and adjust the gas phase flow rate from low to high to change the gas phase flow rate and the height of the accumulated liquid to obtain different working conditions.

3. The method for measuring liquid entrainment by spiral gas flow in a U-shaped tube according to claim 2, characterized in that, the method for measuring liquid entrainment by spiral gas flow in the U-shaped tube further comprises the following steps: According to whether the spiral gas flow can completely carry the accumulated liquid, use different liquid entrainment parameters to measure the liquid entrainment capacity of the spiral gas flow; When the accumulated liquid cannot be completely carried by the spiral gas flow, use the dimensionless height H' to measure the liquid entrainment capacity; When the liquid accumulation can be completely carried by the spiral gas flow, the critical liquid-carrying gas velocity u’ sg is used to measure the liquid-carrying capacity.

4. The method for measuring liquid entrainment by spiral gas flow in a U-shaped tube according to claim 3, characterized in that, the method for measuring liquid entrainment by spiral gas flow in the U-shaped tube further comprises the following steps: Provide a transparent water tank; Place the U-shaped tube in the transparent water tank, inject water into the transparent water tank and make the liquid level submerge the lower end of the U-shaped tube.

5. The method for measuring liquid entrainment by spiral gas flow in a U-shaped tube according to claim 4, characterized in that, the specific method for capturing the gas-liquid phase motion images under different working conditions in the U-shaped tube comprises the following steps: Set a high-speed camera on one side of the U-shaped tube; Set a light source on the other side of the U-shaped tube and place white rice paper between the light source and the U-shaped tube; Capture the gas-liquid phase motion images under different working conditions in the U-shaped tube through the high-speed camera.

6. A computer-readable storage medium, characterized in that, the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the method for measuring liquid entrainment by spiral gas flow in a U-shaped tube according to any one of claims 1-5.

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