Cavitation multiphase flow detection experiment system

Abstract

The utility model discloses a cavitation multiphase flow detection experiment system in the field of fluid testing, which comprises a liquid circulation pipeline module which comprises an inflow section, a gas-liquid mixing section, a testing section and a backflow section and is used for forming a liquid flowing loop and realizing the functions of controllable inflow conditions and outflow state recovery of main flow; the gas inlet and gas-liquid mixing pipeline module is communicated with the gas-liquid mixing section and is used for forming a gas-liquid two-phase fluid medium and realizing the controllability of the gas-phase medium; the cavitation flow experiment module is arranged corresponding to the test section and is used for forming a cavitation flow phenomenon and realizing a cavitation flow visualization function; and the multiphase flow test module is arranged corresponding to the cavitation flow experiment module and is used for detecting the characteristics of the cavitation multiphase flow field and realizing a non-intrusive test function. The gas-liquid two-phase flow state can be controlled, two-phase flow media under different gas-containing conditions can be obtained, cavitation flow states of different degrees can be formed, and cavitation flow characteristics under the influence of gas can be analyzed conveniently.

Description

Technical Field

[0001] This utility model belongs to the field of fluid testing technology, and specifically relates to an experimental system for detecting cavitation multiphase flow. Background Technology

[0002] Cavitation is the process of the appearance, development, and disappearance of cavitation bubbles in a liquid. Cavitation bubbles cause flow channel blockage, accompanied by vibration and noise, which is detrimental to the efficient operation of fluid machinery and leads to energy waste. Experimentally observing cavitation phenomena inside fluid machinery is extremely difficult. Current technologies mostly rely on partially opening windows in the machinery's casing or using endoscopes, thus obtaining very limited information about cavitation flow. Other methods utilize vibration and noise sensors, analyzing the characteristics of vibration and noise signals to indirectly understand the cavitation situation inside the equipment. However, eliminating interference from mechanical vibration and noise remains a challenge.

[0003] With the expansion of energy development and power engineering, cavitation in gas-liquid two-phase flow has attracted attention. Due to the difficulty in measuring and controlling gas-liquid two-phase flow, cavitation is a hot and challenging topic in fluid research. The cavitation flow mechanism under gas-containing conditions is particularly complex, and experimental research techniques are severely lacking.

[0004] Therefore, those skilled in the art are dedicated to developing a cavitation multiphase flow detection experimental system to solve the problem of difficulty in controlling the state of gas-liquid two-phase flow in the existing technology. Utility Model Content

[0005] The purpose of this invention is to provide a cavitation multiphase flow detection experimental system that can control the gas-liquid two-phase flow state to obtain two-phase flow media under different gas-containing conditions, which can form different degrees of cavitation flow state, making it convenient to analyze the cavitation flow characteristics under the influence of gas.

[0006] To achieve the above objectives, this utility model adopts the following technical solution: a cavitation multiphase flow detection experimental system, comprising: a liquid circulation pipeline module, including an inlet section, a gas-liquid mixing section, a test section, and a return section, used to form a liquid flow loop, realizing the function of controllable inlet conditions and restored outlet state; an inlet and gas-liquid mixing pipeline module, connected to the gas-liquid mixing section, used to form a gas-liquid two-phase fluid medium, realizing the controllability of the gas phase medium; a cavitation flow experimental module, set corresponding to the test section, used to form cavitation flow phenomena, realizing the function of visualizing cavitation flow; and a multiphase flow test module, set corresponding to the cavitation flow experimental module, used to detect the characteristics of the cavitation multiphase flow field, realizing a non-invasive testing function.

[0007] The inflow conditions include the inflow liquid flow rate and the inflow liquid temperature. The outflow state is restored so that after one liquid cycle, the conditions for re-inflow are consistent with the previous inflow conditions. Compared with the prior art, the beneficial effects of this utility model are as follows: The liquid circulation pipeline module and the air inlet and gas-liquid mixing pipeline module supply liquid and gas to the cavitation flow experimental module respectively. This separate supply method can avoid leakage or explosion caused by the interaction of gas and liquid inside the storage tank due to pressure and temperature changes, and can also avoid the presence of unknown bubbles or gas masses in the liquid or unknown droplets in the gas, thus improving the accuracy and stability of the experiment. The liquid circulation pipeline module can provide a stable liquid flow rate, ensuring that the liquid is always at the temperature required for the experiment, improving the reliability of the experimental data. The air inlet and gas-liquid mixing pipeline module can regulate the inlet air bubbles. The system allows for the quantitative setting of various intake conditions, including size and flow rate, facilitating cavitation flow research under diverse gas-bearing conditions. The cavitation flow experiment module visualizes different types of cavitation phenomena, enabling researchers to directly observe the cavitation process and multiphase flow characteristics, thus improving teaching effectiveness. The multiphase flow test module provides non-invasive testing of the cavitation multiphase flow field, avoiding the influence of external interference factors on the experimental results. The acquired test data can be used in conjunction with the phenomena recorded by the cavitation flow experiment module for mutual verification and collaborative analysis. Together, these two modules form a comprehensive cavitation multiphase flow field testing system under gas-bearing conditions.

[0008] As a further improvement of this utility model, the cavitation flow experimental module includes a hydraulic cavitation generator installed on the test section, and a flow recording device is installed on the outside of the hydraulic cavitation generator. The flow recording device includes a high-speed camera and an auxiliary light source, which are symmetrically distributed on both sides of the hydraulic cavitation generator. The high-speed camera can capture complex flow phenomena within the hydraulic cavitation generator, and the auxiliary light source provides supplementary illumination, ensuring the clarity of the cavitation flow images and the integrity of the data.

[0009] As a further improvement of this utility model, the multiphase flow testing module includes a temperature sensor 1, a pressure sensor 1, a pressure sensor 2, and a temperature sensor 2 arranged sequentially along the inflow direction on the test section. The hydraulic cavitation generator is located between pressure sensor 1 and pressure sensor 2. A vibration testing device and a conductivity sensor are provided corresponding to the hydraulic cavitation generator. The temperature sensor 1, pressure sensor 1, pressure sensor 2, temperature sensor 2, vibration testing device, and conductivity sensor are all connected to an A / D conversion card. The A / D conversion card is used to convert the electrical signals measured by the sensors into digital signals and transmit them to the computer system. The computer system processes the digital signals and analyzes the multiphase flow characteristics. By using the temperature and pressure sensors located upstream and downstream of the hydraulic cavitation generator, the temperature and pressure of the multiphase flow can be obtained. The vibration testing device can record the vibration under the multiphase flow state within the cavitation generator. The conductivity sensor can acquire the conductivity distribution data of the multiphase flow. The computer system processes and saves this data, enabling rapid, accurate, and safe analysis of the cavitation flow characteristics.

[0010] As a further improvement of this invention, the vibration testing device includes a uniaxial accelerometer, which is mounted on the hydraulic cavitation generator via a fixed bracket. The conductivity sensor is a ring-type non-invasive conductivity sensor, positioned on the outer periphery of the hydraulic cavitation generator. With its high sensitivity and high precision, the uniaxial accelerometer can accurately and comprehensively measure minute vibration signals in the inflow direction, providing further data support for the analysis of cavitation flow characteristics.

[0011] As a further improvement of this utility model, the hydraulic cavitation generating device is one of a Venturi tube, a hydrofoil cavitation generating tube, and a wedge-shaped cavitation generating tube. By changing the type of hydraulic cavitation generating device, data on various cavitation phenomena can be obtained. Compared with a single cavitation phenomenon, it covers the basic types of cavitation and can better reflect the complexity and variability in actual operation, thus making the experimental results more externally valid.

[0012] As a further improvement of this utility model, the liquid circulation pipeline module also includes a temperature-controlled water tank, valve one, a centrifugal pump, and an electromagnetic flowmeter one, arranged sequentially along the inflow direction in the inflow section, and valve two arranged in the return section. This enables flow studies at different temperatures and flow rates with lower experimental costs.

[0013] As a further improvement of this utility model, the temperature-controlled water tank includes a water storage tank, a temperature controller, an electric heating rod, several temperature sensors (3), a cold water switching channel, an electromagnetic flow meter (2), an electromagnetic flow meter (3), a valve (3), and a valve (4). The several temperature sensors (3) are arranged in layers along the height direction of the water storage tank and connected to the temperature controller. The electric heating rod is located at the center near the bottom of the water storage tank. The cold water switching channel is connected to the bottom side of the water storage tank. The electromagnetic flow meter (2) and valve (3) are located at the outlet end of the cold water switching channel, and the electromagnetic flow meter (3) and valve (4) are located at the inlet end of the cold water switching channel. Both the electromagnetic flow meter (2) and electromagnetic flow meter (3) have built-in microprocessors. The microprocessors are used to calculate and display the total flow rate and control the cold water flow rate by adjusting the opening degree of valves (3) and valve (4). When any temperature sensor (3) reaches the set temperature, the temperature controller turns off the power to the electric heating rod and / or closes valves (3) and valve (4). The three temperature sensors arranged in layers form a continuous sensing network inside the water tank, which can comprehensively and completely detect the temperature environment inside the water tank. By adjusting the valve opening and closing degree, the liquid level in the temperature-controlled water tank is always kept within a suitable range, providing a stable experimental basis for the analysis of cavitation flow characteristics.

[0014] As a further improvement of this utility model, the air intake and gas-liquid mixing pipeline module includes an air intake device and a gas-liquid mixing device. The gas-liquid mixing device includes a check valve, a multi-port interface, a gas delivery pipe, and a bubble generator, which are sequentially connected to the air outlet of the air intake device. The multi-port interface connects to multiple gas delivery pipes to ensure that the gas can be uniformly delivered into the liquid. Combined with the bubble generator, the size of the air intake bubbles can be adjusted, allowing for the study of the influence of different bubble size settings on cavitation flow characteristics.

[0015] As a further improvement of this utility model, the multi-port interface includes a gas exhaust distributor. One side of the gas exhaust distributor has an inlet connector, and the other side has 2N equally spaced outlet connectors. The outlet connectors are connected to a bubble generator via gas delivery pipes. The bubble generator includes 2N metal connectors, each with a detachably mounted circular perforated plate. The gas-liquid mixing section has inlet holes adapted to the size and number of the metal connectors. N inlet holes are distributed along the flow direction, with an angle of 360° / N between adjacent inlet holes on the same side. This ensures the stability and consistency of the gas delivery pipes, thereby ensuring that each bubble generator receives sufficient gas pressure and volume, avoiding experimental stagnation due to insufficient airflow. The 360° / N angle between adjacent inlet holes allows for thorough mixing of the bubbles with the liquid components. The perforated plate is a circular cross-section plate with interchangeable opening sizes and numbers to form bubble clusters of different sizes and scales.

[0016] As a further improvement of this utility model, the air intake device includes an air compressor, a filter, an air tank, a pressure reducing valve, a gas solenoid valve, and a gas flow meter connected in sequence. The air compressor input is equipped with a filter screen, and the air tank is equipped with a pressure gauge and a safety valve. The gas flow meter is used to monitor the gas flow rate at the output of the air intake device in real time. The pressure gauge is used to display the gas pressure value in the air tank in real time. The gas solenoid valve is used to quickly cut off or connect the gas passage. By adjusting the pressure reducing valve, the gas pressure is changed, thereby adjusting the gas flow rate. The compressor with the filter screen and filter can control the air quality, ensuring the purity of the gas. The gas is pressurized before entering the air tank and the system pressure is stabilized, ensuring the stability of the output gas flow rate and pressure, and ensuring the characteristics of the gas entering the experimental system. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the system structure of a preferred embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the structure of the temperature-controlled water tank according to a preferred embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the structure of the multiphase flow test module of the preferred embodiment of this utility model.

[0020] Figure 4 This is a schematic diagram of the structure of a hydraulic cavitation generator according to a preferred embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the structure of a circular perforated plate according to a preferred embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram of the structure of the multi-port interface in a preferred embodiment of the present invention.

[0023] Figure 7 This is a schematic diagram showing the distribution of the air inlet holes in a preferred embodiment of the present invention.

[0024] Figure 8 This is a schematic diagram showing the distribution of cavitation phenomena under a hydraulic cavitation generator.

[0025] The components include: 1. Temperature-controlled water tank; 2. Valve 1; 3. Centrifugal pump; 4. Electromagnetic flow meter 1; 5. Gas-liquid mixing device; 6. Gas-liquid mixing section; 7. Metal connector; 8. Perforated plate; 9. Gas delivery pipe; 10. Multi-port interface; 11. Check valve; 12. Temperature sensor 1; 13. Pressure sensor 1; 14. Hydraulic cavitation generator; 15. Pressure sensor 2; 16. Temperature sensor 2; 17. Valve 2; 18. Air intake device; 19. Gas flow meter; 20. Gas storage tank; 21. Pressure gauge; 22. Safety valve; 23. Pressure reducing valve; 24. Gas solenoid valve; 25. Filter; 26. Air compressor; 27. Vibration testing device; 28. Single-axis accelerometer; 29. ​​Flow recording device; 30. High-speed camera; 31. 32 A / D conversion card, 33 Computer system, 34 Temperature controller, 35 Electric heating rod, 36 Valve III, 37 Electromagnetic flow meter II, 38 Electromagnetic flow meter III, 39 Temperature sensor III, 40 Conductivity sensor, 41 Liquid flow circuit, 42 Air exhaust distributor, 43 Air outlet connector. Detailed Implementation

[0026] like Figure 1-3 The diagram shows a cavitation multiphase flow detection experimental system, comprising: a liquid circulation pipeline module, including an inflow section, a gas-liquid mixing section 6, a test section, and a return section; and a temperature-controlled water tank 1, valve 1 2, a centrifugal pump 3, and an electromagnetic flowmeter 4 sequentially arranged along the inflow direction on the inflow section, and a valve 2 17 arranged on the return section, used to form a liquid flow loop 41, realizing the function of controllable inflow conditions and restored outflow state; an air inlet and gas-liquid mixing pipeline module, connected to the gas-liquid mixing section 6, used to form a two-phase fluid medium of gas and liquid, realizing the controllability of the gas phase medium; a cavitation flow experimental module, set corresponding to the test section, used to form cavitation flow phenomena, realizing the function of cavitation flow visualization; and a multiphase flow test module, set corresponding to the cavitation flow experimental module, used to detect the characteristics of the cavitation multiphase flow field, realizing the function of non-invasive testing; specifically, the inflow conditions include the inflow liquid flow rate and the inflow liquid temperature, and the outflow state is restored to the condition that the conditions for re-entry after one liquid cycle are consistent with the previous inflow conditions.

[0027] In this embodiment, the temperature-controlled water tank 1 includes a water storage tank, a temperature controller 33, an electric heating rod 34, six temperature sensors 39, a cold water switching channel, an electromagnetic flow meter 36, an electromagnetic flow meter 38, a valve 35, and a valve 37. The six temperature sensors 39 are symmetrically distributed in pairs and arranged in layers along the height of the water storage tank, and are all connected to the temperature controller 33. The electric heating rod 34 is located at the center near the bottom of the water storage tank. The cold water switching channel is connected to the bottom side of the water storage tank. The electromagnetic flow meter 36 and the valve 37... Valve 35 is located at the outlet of the cold water switching channel, while electromagnetic flow meter 38 and valve 4 are located at the inlet of the cold water switching channel. Electromagnetic flow meter 2 36 and electromagnetic flow meter 38 are both equipped with microprocessors. The microprocessors are used to calculate and display the total flow rate and control the cold water flow rate by adjusting the opening and closing of valves 35 and 4. When any temperature sensor 39 reaches the set temperature, the temperature controller 33 turns off the power to the electric heating rod 34 and / or closes valves 35 and 4.

[0028] The cavitation flow experiment module includes a hydraulic cavitation generator 14 installed on the test section. A flow recording device 29 connected to a computer system 32 is installed on the outside of the hydraulic cavitation generator 14. The flow recording device 29 includes a high-speed camera 30 symmetrically distributed on both sides of the hydraulic cavitation generator 14 and an auxiliary light source. When the flow in the section of the hydraulic cavitation generator 14 is visible, the flow of the medium and the cavitation occurrence in the cavitation generator are displayed synchronously through the connection of the computer system 32 and the high-speed camera 30.

[0029] Since cavitation is accompanied by heat absorption or release, the degree of cavitation can be reflected by measuring the temperature of the fluid surrounding the hydraulic cavitation generator 14. Since cavitation is accompanied by pressure fluctuations, the degree of cavitation and its impact can be reflected by measuring the pressure pulsation of the fluid at the inlet and outlet of the hydraulic cavitation generator 14. The multiphase flow test module includes a temperature sensor 12, a pressure sensor 13, a pressure sensor 15, and a temperature sensor 16 arranged sequentially along the inflow direction on the test section. A hydraulic cavitation generator 14 is located between the pressure sensor 13 and the pressure sensor 15. The degree of cavitation is determined by the upstream and downstream temperature changes and pressure pulsations. A vibration test device 27 and a conductivity sensor 40 are provided corresponding to the hydraulic cavitation generator 14. The temperature sensor 12, pressure sensor 13, pressure sensor 15, temperature sensor 16, vibration test device 27, and conductivity sensor 40 are all connected to an A / D conversion card 31. The A / D conversion card 31 is used to convert the electrical signals measured by the sensors into digital signals and transmit them to the computer system 32. The computer system 32 processes the digital signals and analyzes the multiphase flow characteristics.

[0030] The following is through Figure 4 The hydraulic cavitation generator 14 is described in detail. It is one of three types: a venturi tube, a hydrofoil cavitation generator, and a wedge-shaped cavitation generator. The hydrofoil cavitation generator includes a mounting flange, a test pipe, and a hydrofoil fixed at the center of the test pipe section. The wedge-shaped cavitation generator includes a mounting flange, a test pipe, and a wedge-shaped block fixed at the bottom of the test pipe. The corresponding model is selected according to the experimental requirements and connected to the liquid circulation pipeline system through the mounting flange. Both the venturi tube and the test pipe are made of transparent plexiglass, which enables the visualization of the flow field. Pressure sensors and temperature sensors are installed upstream and downstream of the hydraulic cavitation generator 14 to monitor the pressure and temperature of the medium passing through the hydraulic cavitation generator 14.

[0031] The vibration testing device 27 includes a uniaxial acceleration sensor 28, which is mounted on the hydraulic cavitation generator 14 via a fixed bracket. The conductivity sensor 40 is a ring-type non-invasive conductivity sensor 40. Taking a venturi tube as an example, the conductivity sensor 40 is sleeved on the outer periphery of the throat of the venturi tube, which can measure the conductivity of different liquid media without affecting the flow of the liquid itself.

[0032] The air intake and gas-liquid mixing pipeline module includes an air intake device 18 and a gas-liquid mixing device 5. The air intake device 18 includes an air compressor 26, a filter 25, an air tank 20, a pressure reducing valve 23, a gas solenoid valve 24, and a gas flow meter 19 connected in sequence. The air compressor 26 is equipped with a filter screen at its input end. The air tank 20 is equipped with a pressure gauge 21 and a safety valve 22. The gas flow meter 19 is used to monitor the gas flow at the output end of the air intake device 18 in real time. The pressure gauge 21 is used to display the gas pressure value in the air tank 20 in real time. The gas solenoid valve 24 is controlled by a computer system 32 and is used to quickly cut off or connect the gas passage.

[0033] The gas-liquid mixing device 5 includes a check valve 11, a multi-port connector 10, a gas delivery pipe 9, and a bubble generator, all sequentially connected to the gas solenoid valve 24. The multi-port connector 10 includes a gas exhaust distributor 42, with an inlet connector on one side and six equidistant outlet connectors 43 on the other side. Figure 5 As shown, the gas outlet connector 43 is connected to the bubble generator via the gas delivery pipe 9. The bubble generator includes six metal connectors 7, and each metal connector 7 has a detachably mounted circular perforated plate 8, such as... Figure 6 As shown, taking N=3 as an example, the gas-liquid mixing section 6 has air inlets that are compatible with the size and number of the metal connector 7. Three air inlets are distributed along the front and rear of the flow direction, and the angle between two adjacent air inlets on the same side is 120°. Figure 7 As shown, in practical applications, the number of air inlets can be increased or decreased depending on the size of the circulation pipeline.

[0034] After coarse filtration by the filter screen, the air enters the air compressor 26. After being compressed, it enters the filter 25 for secondary fine filtration, removing tiny particles, moisture, and other impurities from the air. The air is then stored in the air tank 20. After the air tank 20 stabilizes the pressure, the gas passes through the gas solenoid valve 24, then through the gas flow meter 19, and then through the check valve 11 into the gas exhaust distributor 42. Finally, the size and scale of the bubbles are controlled by the bubble generator, thereby controlling the composition of the gas-liquid two-phase flow. The principle of adjusting the bubble size is as follows: In the gas-liquid mixing device 5, the gas reaches the porous plate 8 through the gas delivery pipe 9. Porous plates 8 with different opening sizes and numbers have the effect of dispersing and refining the gas. Porous plates 8 with small opening sizes and a large number of openings will cause the gas to be divided into smaller bubbles when passing through; conversely, porous plates 8 with large opening sizes and a small number of openings will generate larger bubbles. The principle of adjusting the intake bubble flow rate is as follows: the bubble flow rate is mainly adjusted by controlling the gas flow rate. In the intake device 18, the gas flow meter 19 monitors the gas flow rate in real time, and the pressure sensor monitors the gas pressure. The gas pressure is changed by adjusting the pressure reducing valve 23, thereby adjusting the gas flow rate. When the opening of the pressure reducing valve 23 increases, the gas pressure decreases, the flow rate increases, and the flow rate increases. Conversely, when the opening of the pressure reducing valve 23 decreases, the gas pressure increases, the flow rate decreases, and the flow rate decreases accordingly. The gas solenoid valve 24 works in conjunction with the pressure reducing valve 23. When precise control of the gas flow rate is required, the gas solenoid valve 24 can quickly cut off or connect the gas passage.

[0035] The experimental steps using this utility model system are as follows:

[0036] S1: First, set the temperature of the water tank 1 using the temperature controller 33, open valve 35, add an appropriate amount of water to the water tank, turn on the electric heating rod 34, and after the set temperature is reached, the temperature controller 33 cuts off the power and stops heating.

[0037] S2: Turn on the air compressor 26 until the pressure inside the air tank 20 reaches the set value required for the experiment, and connect the metal connector 7 to the air inlet of the gas-liquid mixing section 6 respectively.

[0038] S3: Start centrifugal pump 3, slowly open valve 12 and valve 217, so that the water in the water tank flows through electromagnetic flow meter 14, temperature sensor 12, pressure sensor 13, hydraulic cavitation generator 14, pressure sensor 215, temperature sensor 216 in sequence, and finally returns to the temperature-controlled water tank 1 through valve 217.

[0039] S4: The control computer system 32 opens the gas solenoid valve 24 and adjusts the pressure reducing valve 23, so that the gas in the gas storage tank 20 flows through the pressure reducing valve 23, solenoid valve, check valve 11, multi-port 10 and gas delivery pipe 9 in sequence, and forms dispersed small bubbles under the action of the perforated plate 8. In the gas-liquid mixing section 6, it is fully mixed with the liquid to form a two-phase flow.

[0040] S5: The high-speed camera 30 is connected to the computer system 32, and the images it captures are displayed on the computer system 32. At the same time, the vibration of the cavitation generator, the conductivity distribution, the temperature changes of the upstream and downstream, and the pressure pulsation are all transmitted by the sensors to the A / D conversion card 31. The A / D conversion card 31 then converts the relevant signals into digital signals and displays them synchronously in the computer system 32, and saves them together with the captured images.

[0041] S6: After the experiment, first turn off the compressor, then close the gas solenoid valve 24, slowly close valve 1 2 and valve 2 17, and finally cut off the power to the centrifugal pump 3.

[0042] S7: According to the experimental requirements, change the temperature of the water in the tank. And repeat the above steps.

[0043] like Figure 8 The figures show schematic diagrams illustrating the distribution of cavitation phenomena of different degrees and types. Figure (a) shows examples of floating bubble-like cavitation and fixed sheet-like cavitation in a venturi tube; Figure (b) shows examples of floating bubble-like cavitation, attached sheet-like cavitation, and terminal-detached cloud-like cavitation in a hydrofoil cavitation generator; and Figure (c) shows examples of attached sheet-like cavitation and terminal-detached cloud-like cavitation in a wedge-shaped cavitation generator. Experiments on various cavitation phenomena can reveal the influence of different gas-bearing conditions on different cavitation types, providing new information for studying cavitation flow characteristics.

[0044] This utility model is not limited to the above embodiments. Based on the technical solutions disclosed in this utility model, those skilled in the art can make some substitutions and modifications to some of the technical features without creative labor, and these substitutions and modifications are all within the protection scope of this utility model.

Claims

1. A cavitation multiphase flow detection experimental system, characterized in that, The utility model relates to a liquid circulating pipeline module, an air inlet and gas-liquid mixing pipeline module, a cavitation flow experiment module and a multiphase flow test module. The liquid circulating pipeline module comprises an inflow section, a gas-liquid mixing section, a test section and a backflow section, and is used to form a liquid flow loop to realize controllable inflow conditions and recovery of outflow state of the main flow. The air inlet and gas-liquid mixing pipeline module is connected with the gas-liquid mixing section and is used to form a gas-liquid two-phase fluid medium to realize controllability of the gas phase medium. The cavitation flow experiment module is arranged corresponding to the test section and is used to form a cavitation flow phenomenon to realize visualization of the cavitation flow. The multiphase flow test module is arranged corresponding to the cavitation flow experiment module and is used to detect characteristics of the cavitation multiphase flow field to realize non-invasive testing.

2. The experimental system for cavitation multiphase flow detection according to claim 1, wherein, The cavitation flow experiment module comprises a hydraulic cavitation generating device arranged on the test section, and a flow recording device is arranged corresponding to the outer side of the hydraulic cavitation generating device.

3. The experimental system for cavitation multiphase flow detection according to claim 2, characterized in that, The multiphase flow test module comprises a temperature sensor one, a pressure sensor one, a pressure sensor two and a temperature sensor two arranged in sequence along the inflow direction on the test section, and the hydraulic cavitation generating device is located between the pressure sensor one and the pressure sensor two.

4. The experimental system for cavitation multiphase flow detection according to claim 3, characterized in that, A vibration test device and an electrical conductivity sensor are arranged corresponding to the hydraulic cavitation generating device, and the temperature sensor one, the pressure sensor one, the pressure sensor two, the temperature sensor two, the vibration test device and the electrical conductivity sensor are connected with an A / D conversion card.

5. The experimental system for cavitation multiphase flow detection according to claim 2, wherein, The A / D conversion card is used to convert the electrical signals measured by the sensors into digital signals and transmit the digital signals to a computer system.

6. The experimental system for cavitation multiphase flow detection according to claim 1, wherein, The computer system processes the digital signals and analyzes the characteristics of the multiphase flow. The vibration test device comprises a single-axis acceleration sensor arranged on the hydraulic cavitation generating device through a fixing support. The electrical conductivity sensor is a circular ring type non-invasive electrical conductivity sensor and is arranged on the outer periphery of the hydraulic cavitation generating device. The hydraulic cavitation generating device is one of a Venturi tube, a water wing cavitation generating tube and a wedge cavitation generating tube. The liquid circulating pipeline module further comprises a temperature control water tank, a valve one, a centrifugal pump and an electromagnetic flowmeter one arranged in sequence along the inflow direction on the inflow section, and a valve two arranged on the backflow section.

7. The experimental system for cavitation multiphase flow detection according to claim 6, wherein, The temperature-controlled water tank comprises a water storage tank, a temperature controller, an electric heating rod, a plurality of temperature sensors three, a cold water switching channel, an electromagnetic flowmeter two, an electromagnetic flowmeter three, a valve three and a valve four, the plurality of temperature sensors three are arranged in layers along the height direction of the water storage tank and are connected with the temperature controller, the electric heating rod is arranged at the center position close to the bottom of the water storage tank, the cold water switching channel is communicated with the side of the bottom of the water storage tank, the electromagnetic flowmeter two and the valve three are arranged at the water outlet end of the cold water switching channel, the electromagnetic flowmeter three and the valve four are arranged at the water inlet end of the cold water switching channel, the electromagnetic flowmeter two and the electromagnetic flowmeter three are both internally provided with a microprocessor, the microprocessor is used for calculating and displaying the total flow, and the cold water flow size is controlled by adjusting the opening degree of the valve three and the valve four, and the temperature controller is used for closing the power supply of the electric heating rod and / or closing the valve three and the valve four when any temperature sensor three reaches the set temperature.

8. The experimental system for cavitation multiphase flow detection according to claim 1, wherein, The air inlet and gas-liquid mixing pipeline module comprises an air inlet device and a gas-liquid mixing device, and the gas-liquid mixing device comprises, in sequence and in communication with the air outlet end of the air inlet device, a check valve, a multi-way interface, a gas conveying pipe and a bubble generator.

9. The experimental system for cavitation multiphase flow detection according to claim 8, characterized in that, The multi-way interface comprises an air exhaust shunt, one side of the air exhaust shunt is provided with an air inlet joint, the other side is provided with 2N air outlet joints distributed at equal intervals, the air outlet joints are communicated with the bubble generator through the gas conveying pipe, the bubble generator comprises 2N metal joints, a circular perforated plate is detachably arranged in the metal joint, the gas-liquid mixing section is provided with air inlet holes which are adapted to the size and number of the metal joints, the air inlet holes are distributed in N groups in front and behind along the inflow direction, and the included angle between adjacent two air inlet holes on the same side is 360° / N.

10. The experimental system for cavitation multiphase flow detection according to claim 9, wherein, The air inlet device comprises, in sequence, an air compressor, a filter, an air tank, a pressure reducing valve, a gas solenoid valve and a gas flowmeter, the air compressor is provided with a filter screen at the input end, the air tank is provided with a pressure gauge and a safety valve, the gas flowmeter is used for monitoring the gas flow at the output end of the air inlet device in real time, the pressure gauge is used for displaying the gas pressure value in the air tank in real time, and the gas solenoid valve is used for quickly cutting off or connecting the gas passage.

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