An experimental device and method for measuring solid-liquid two-phase flow characteristics in a vertical pipeline

Abstract

The present invention discloses an experimental device and method for measuring the characteristics of solid-liquid two-phase flow in a vertical pipeline, which mainly includes a circulating water tank, a fluid transport control module, a particle accumulation module, a temperature and pressure measurement module, and an image acquisition module. The present invention can measure the flow rate changes, temperature and pressure changes, and particle group motion morphology changes of solid-liquid two-phase flow in a vertical pipeline in real time, providing a scientific basis and technical support for the research on the laws of vertical pipe particulate material transportation. The present invention also provides a new experimental system and testing technology for the research of solid-liquid two-phase flow in vertical pipelines, and application scenarios include but are not limited to deep-sea mining, deep-sea natural gas hydrate transportation, food industry, coal industry, etc.

Description

Technical Field

[0001] The present invention belongs to the field of deep-sea mining, and in particular relates to an experimental device and method for measuring solid-liquid two-phase flow characteristics in a vertical pipeline. Background Art

[0002] The problem of solid-liquid two-phase flow in vertical pipelines is widely present in various fields, such as the hydraulic lifting mining method of deep-sea ore combining a ore collector and a pipeline, and the solid-state fluidization mining method of deep-sea natural gas hydrates. The solid-liquid two-phase flow law in the pipeline is closely related to the mining efficiency of actual engineering. Therefore, it is very important to study the interaction law between particles and fluids in vertical pipelines. However, this is a complex dynamic process of mutual coupling and coordination between multi-scale flow structures, and is affected by many factors. In addition, due to the large particle size, the pipeline wall restriction effect is enhanced, resulting in a more complex flow pattern. At present, there is a lack of research on this problem. Therefore, the present invention proposes an experimental measurement device for two-phase flow (particles and fluid) in a vertical pipeline. Summary of the Invention

[0003] To solve the above technical problems, the present invention provides an experimental device and method for measuring the solid-liquid two-phase flow characteristics in a vertical pipeline, so as to finely control the circulating flow rate and clearly display the phase changes of the two-phase flow process in a transparent pipeline.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] An experimental device for measuring solid-liquid two-phase flow characteristics in a vertical pipeline includes a circulating water tank, a fluid delivery control module, a particle accumulation module, a temperature and pressure measurement module, and an image acquisition module. The circulating water tank is connected to the fluid delivery control module, which is connected to the particle accumulation module. The temperature and pressure measurement module is connected to the particle accumulation module to record changes in temperature and pressure during the interaction between particles and fluid. The image acquisition module is used to capture images of particle motion.

[0006] The fluid delivery control module includes a frequency meter, a frequency conversion pump, an electromagnetic flow meter, and an opening valve; the electromagnetic flow meter is connected to the frequency meter, the frequency meter is connected to the frequency conversion pump, and the frequency conversion pump is connected to the opening valve;

[0007] The particle accumulation module includes a first vertical pipe, a second vertical pipe and a third vertical pipe; the first vertical pipe, the second vertical pipe and the third vertical pipe are connected in sequence from top to bottom, and the first vertical pipe is installed with an electromagnetic flowmeter;

[0008] Two water inlet holes are opened on the upper part of the circulating water tank, which are connected to the upper part of the first vertical pipe to form a closed loop; the circulating water tank is connected to the outlet pipe, and the outlet pipe is connected to the third vertical pipe through a variable frequency pump, an opening valve, and a horizontal pipe section.

[0009] Furthermore, the lengths of the first vertical pipe, the second vertical pipe and the third vertical pipe are 1.0 m, 0.5 m and 1.5 m respectively.

[0010] Furthermore, the second vertical pipe is a detachable section, and before the experiment begins, the second vertical pipe is disassembled and a certain amount of particles are loaded.

[0011] Furthermore, a metal filter is installed at the bottom of the third vertical pipe to support particles and allow the fluid to pass through the metal filter to form a stable water flow.

[0012] Furthermore, the circulating water tank is used to supply circulating water to the experimental device. The size of the circulating water tank is 1m×1m×1m. A water storage valve is installed under the circulating water tank, and the outlet pipe is connected to the variable frequency pump to control the amount of water output.

[0013] Furthermore, the third vertical pipe is connected to the lower horizontal pipe section by a quick-install flange, which is convenient for disassembly.

[0014] Furthermore, the frequency converter is connected to the frequency converter pump to control the speed of the frequency converter pump, with a speed range of 1-50 rpm; the electromagnetic flowmeter is connected to the frequency converter to feedback the current flow and dynamically adjust the speed of the frequency converter pump; the user inputs the set flow to control the speed of the frequency converter pump, realizing real-time adjustment.

[0015] Furthermore, the temperature and pressure measurement module is equipped with 4 temperature measurement sensors and 4 pressure measurement sensors in the third vertical pipe.

[0016] Furthermore, the image acquisition module includes a control computer and a camera for capturing images of particle motion, wherein the camera includes a long-time camera.

[0017] The present invention also provides an experimental method for measuring solid-liquid two-phase flow characteristics in a vertical pipeline, comprising the following steps:

[0018] Step (1) Open the opening valve, set the frequency of the variable frequency pump, and pre-circulate the experimental device for 1 minute to remove possible impurities in the pipeline;

[0019] Step (2) closing the variable frequency pump and the opening valve, disassembling the second vertical pipe, loading the granular material into the third vertical pipe, and reinstalling the second vertical pipe;

[0020] Step (3) Open the opening valve and increase the frequency of the variable frequency pump in steps until the electromagnetic flowmeter displays the set flow rate;

[0021] Step (4) turning on the camera of the image acquisition module to record the particle motion image;

[0022] Step (5) stepwise reduce the frequency of the variable frequency pump to 0, close the opening valve, disassemble the upper flange of the horizontal pipe section, remove the granular material, and reinstall the flange;

[0023] Step (6) exporting flow, temperature, and pressure data from the fluid delivery control module for post-analysis;

[0024] Step (7) Turn off the power.

[0025] Beneficial effects:

[0026] This invention addresses a key issue in my country's deep-sea mining sector: long-distance pipeline transportation. It proposes an experimental device for measuring the interaction between large particles and fluids within pipelines and analyzing particle flow patterns. This device enables precise control of circulating flow rates and clearly displays phase changes during two-phase flow within transparent pipelines. Furthermore, the device is easy to install and disassemble, with modular integration of its components, improving experimental efficiency and facilitating subsequent optimization. Furthermore, the device stores key experimental variables in real time, enabling automated and efficient data collection. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The figure is a schematic structural diagram of an experimental device for measuring solid-liquid two-phase flow characteristics in a vertical pipeline according to the present invention. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0029] like Figure 1 As shown, the experimental apparatus for measuring solid-liquid two-phase flow characteristics in a vertical pipeline comprises a circulating water tank 1, a fluid delivery control module 2, a particle accumulation module 3, a temperature and pressure measurement module 4, and an image acquisition module 5. The circulating water tank 1 is connected to the fluid delivery control module 2, which is in turn connected to the particle accumulation module 3. The temperature and pressure measurement module 4 is connected to the particle accumulation module 3. The image acquisition module 5 is independent and is used to capture images of particle motion.

[0030] The circulating water tank 1 is used to supply circulating water to the entire experimental device. The size of the circulating water tank 1 is 1m×1m×1m. A water storage valve is installed at the bottom of the circulating water tank 1, and the outlet pipe 6 is connected to the frequency conversion pump to control the amount of water output. Two water inlet holes are opened on the upper part of the circulating water tank 1, and the water inlet holes are connected to the top of the first vertical pipe 7, the second vertical pipe 8 and the third vertical pipe 9 to form a closed loop. The circulating water tank 1 is connected to the outlet pipe 6, and the outlet pipe 6 is connected to the third vertical pipe 9 through the frequency conversion pump, the opening valve, and the horizontal pipe section 10. The first vertical pipe 7 is then connected to the circulating water tank 1. This design can ensure that the circulating water system will not be disturbed by the outside world.

[0031] The fluid delivery control module 2 mainly includes a frequency converter, a frequency conversion pump, an electromagnetic flow meter, and an opening valve. The frequency converter is connected to the frequency conversion pump to control the speed of the frequency conversion pump, and the speed range is 1-50 rpm. The electromagnetic flow meter is connected to the frequency converter to feedback the current flow and dynamically adjust the speed of the frequency conversion pump. The user only needs to input the set flow to control the speed of the frequency conversion pump and realize real-time adjustment. The opening of the opening valve is generally 30%-100%. Its main function is to prevent the water in the circulating water tank 1 from entering the vertical pipe when the experimental device is idle, causing problems such as rust on metal components. The second is to prevent the static water pressure in the circulating water tank 1 from being too large when the initial experiment is started, making the flow uncontrollable. Therefore, the opening valve needs to be set to the minimum value before the experiment begins, and the opening of the opening valve should be gradually increased after the delivery circulation flow stabilizes. The positions of the frequency converter, frequency conversion pump, electromagnetic flow meter, and opening valve are as follows Figure 1 As shown, the electromagnetic flowmeter is connected to the frequency converter, the frequency converter is connected to the frequency converter pump, and the frequency converter pump is connected to the opening valve.

[0032] The particle accumulation module 3 includes a metal filter and a first vertical pipe 7, a second vertical pipe 8 and a third vertical pipe 9. The inner diameter of the first vertical pipe 7 is 50 mm, so the number of particles required for the experiment can be converted based on the volume, porosity and initial stacking height. The first vertical pipe 7, the second vertical pipe 8 and the third vertical pipe 9 are connected in sequence from top to bottom, with lengths of 1.0 m, 0.5 m and 1.5 m respectively. The third vertical pipe 9 is set to 1.5 m, mainly because the two-phase flow interaction section is located in this interval and it is more convenient to record images in this interval. The second vertical pipe 8 in the middle is a detachable section. Before the experiment begins, this section of the pipe is disassembled and a certain number of particles are loaded. The upper first vertical pipe 7 is equipped with an electromagnetic flowmeter. Since the measurement accuracy of the electromagnetic flowmeter will be affected by particulate matter, and there are fewer particles in this interval, a more accurate fluid flow value in the pipe can be obtained. The measurement range of the electromagnetic flowmeter is 2-40 m 3 / h, with a response time of less than 5ms, fully meeting the requirements of the measurement pipe section. The particle accumulation area is located at the bottom of the third vertical pipe 9, and a metal filter is installed at the bottom. On the one hand, it plays a role in supporting the particles, and on the other hand, the fluid passes through the metal filter to form a stable water flow. The third vertical pipe 9 is connected to the lower horizontal pipe section 10 with a quick-release flange, which is easy to disassemble. After the test is completed, this quick-release flange can be opened to remove the particles in the pipe. Preferably, the horizontal pipe section 10 is metal.

[0033] The temperature and pressure measurement module 4 is equipped with four temperature sensors and four pressure sensors in the third vertical pipe 9. The pressure sensors have a measurement range of 0-1 MPa and a response time of less than 1.5 ms. The temperature sensors have a measurement range of 10-100 degrees Celsius. The temperature and pressure measurement module 4 primarily records changes in temperature and pressure during the interaction between particles and fluid.

[0034] The image acquisition module 5 includes a control computer and a camera for capturing images of particle motion. During the experiment, the motion of the particle swarm is also an important physical quantity. Therefore, the experimental apparatus of the present invention is also equipped with a long-term video camera, a Hikvision DS-2CE16C3T-IT3 color camera with a maximum recording time of 12 hours. The motion images of the two-phase flow in each experiment were fully recorded for later analysis.

[0035] The use process of the experimental device for measuring the solid-liquid two-phase flow characteristics in a vertical pipeline of the present invention is as follows: (1) open the opening valve, set the frequency of the variable frequency pump, pre-circulate the experimental device for 1 minute, and remove possible impurities in the pipeline; (2) close the variable frequency pump and the opening valve, disassemble the second vertical pipeline 8, load granular material into the third vertical pipeline 9, and reinstall the second vertical pipeline 8; (3) open the opening valve, step-by-step increase the frequency of the variable frequency pump until the electromagnetic flowmeter displays the set flow; (4) turn on the camera of the image acquisition module 5 to record the particle movement image; (5) step-by-step reduce the frequency of the variable frequency pump to 0, close the opening valve, disassemble the upper flange of the horizontal pipe section 10, take out the granular material, and reinstall the flange; (6) export the flow, temperature, and pressure data from the fluid delivery control module 2 for post-analysis; (7) turn off the power.

[0036] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An experimental device for measuring solid-liquid two-phase flow characteristics in a vertical pipeline, characterized in that: The system can finely control the circulating flow rate and clearly display the phase changes of the two-phase flow process in the transparent pipe, including a circulating water tank, a fluid delivery control module, a particle accumulation module, a temperature and pressure measurement module, and an image acquisition module; the circulating water tank is connected to the fluid delivery control module, which is connected to the particle accumulation module; the temperature and pressure measurement module is connected to the particle accumulation module to record the changes in temperature and pressure during the interaction between particles and fluid; the image acquisition module is used to capture images of particle movement; The fluid delivery control module includes a frequency meter, a frequency conversion pump, an electromagnetic flow meter, and an opening valve; the electromagnetic flow meter is connected to the frequency meter, the frequency meter is connected to the frequency conversion pump, and the frequency conversion pump is connected to the opening valve; The particle accumulation module includes a first vertical pipe, a second vertical pipe and a third vertical pipe; the first vertical pipe, the second vertical pipe and the third vertical pipe are connected in sequence from top to bottom, and the first vertical pipe is installed with an electromagnetic flowmeter; Two water inlet holes are opened on the upper part of the circulating water tank, and the water inlet holes are connected to the upper part of the first vertical pipe to form a closed loop; the circulating water tank is connected to the water outlet pipe, and the water outlet pipe is connected to the third vertical pipe through a variable frequency pump, an opening valve, and a horizontal pipe section; The second vertical pipe is a detachable section. Before the experiment begins, the second vertical pipe is disassembled and a certain amount of particles are loaded; A metal filter is installed at the bottom of the third vertical pipe to support particles and allow the fluid to pass through the metal filter to form a stable water flow; The temperature and pressure measurement module is equipped with 4 temperature measurement sensors and 4 pressure measurement sensors in the third vertical pipe; The image acquisition module includes a control computer and a camera for capturing particle motion images, wherein the camera includes a long-time camera.

2. The experimental device for measuring solid-liquid two-phase flow characteristics in a vertical pipeline according to claim 1, characterized in that: The lengths of the first vertical pipe, the second vertical pipe and the third vertical pipe are 1.0 m, 0.5 m and 1.5 m respectively.

3. The experimental device for measuring solid-liquid two-phase flow characteristics in a vertical pipeline according to claim 1, characterized in that: The circulating water tank is used to supply circulating water to the experimental device. The size of the circulating water tank is 1 m×1 m×1 m. A water storage valve is installed at the bottom of the circulating water tank, and the outlet pipe is connected to the variable frequency pump to control the amount of water output.

4. The experimental device for measuring solid-liquid two-phase flow characteristics in a vertical pipeline according to claim 1, characterized in that: The third vertical pipe is connected to the lower horizontal pipe section by a quick-install flange, which is easy to disassemble.

5. The experimental device for measuring solid-liquid two-phase flow characteristics in a vertical pipeline according to claim 1, characterized in that: The frequency converter is connected to the frequency converter pump to control the speed of the frequency converter pump, with a speed range of 1-50 rpm; the electromagnetic flowmeter is connected to the frequency converter to feedback the current flow and dynamically adjust the speed of the frequency converter pump; the user inputs the set flow to control the speed of the frequency converter pump, realizing real-time adjustment.

6. The experimental method of the experimental device for measuring solid-liquid two-phase flow characteristics in a vertical pipeline according to any one of claims 1 to 5, characterized in that: The steps include: Step (1) Open the opening valve, set the frequency of the variable frequency pump, and pre-circulate the experimental device for 1 minute to remove possible impurities in the pipeline; Step (2) closing the variable frequency pump and the opening valve, disassembling the second vertical pipe, loading granular material into the third vertical pipe, and reinstalling the second vertical pipe; Step (3) Open the opening valve and increase the frequency of the variable frequency pump in steps until the electromagnetic flowmeter displays the set flow rate; Step (4) turning on the camera of the image acquisition module to record the particle motion image; Step (5) Stepwise reduce the frequency of the variable frequency pump to 0, close the opening valve, disassemble the upper flange of the horizontal pipe section, remove the granular material, and reinstall the flange; Step (6) exporting flow, temperature, and pressure data from the fluid delivery control module for post-analysis; Step (7) Turn off the power.

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