Testing device for gas-liquid two-phase jet flow condensation in pipe and multi-physical field measuring method

Abstract

The invention provides an in-pipe gas-liquid two-phase jet flow condensation testing device and a multi-physical field measuring method. In the testing device, a water storage tank, a variable frequency pump, an electromagnetic valve, a mass flow meter, a heater and a visual testing section are sequentially connected in the flow direction of a medium; an outlet of the visual test section is sequentially connected with a condenser, an electromagnetic valve and a water storage tank; an outlet of the heater, an outlet of the visual test section and an outlet of the electromagnetic valve are all provided with pressure sensors and thermocouples; the deionized water tank, the electric heating boiler, the regulating valve, the vortex shedding flowmeter and the visual test section are sequentially connected in the flow direction of a medium, a pressure sensor and a thermocouple are arranged at an outlet of the vortex shedding flowmeter, and a steam nozzle, a pressure sensor, a thermocouple, a plurality of hydrophones, an accelerometer and a sound wave generator are arranged on the visual test section; wide-range regulation and control of flow velocity and pressure of a supercooled working medium can be realized, and the problems of difficulty in flow velocity and pressure regulation and control of a static working medium experimental device and laboratory reproduction of a condensation instability mechanism under a dynamic working condition are solved.

Description

Technical Field

[0001] The present invention belongs to the field of jet heat exchange and heat storage, and in particular relates to a testing device for gas-liquid two-phase jet condensation in a tube and a multi-physical field measurement method. Background Art

[0002] Direct contact condensation of a steam jet in a supercooled fluid within a tube is a highly efficient heat and mass transfer process with nearly 100% energy efficiency. It is considered a core heat and mass transfer solution in the energy and nuclear engineering fields, including nuclear reactor thermal hydraulics, high-thrust liquid rocket engines, and underwater propulsion systems. This process achieves near-instantaneous energy exchange through dynamic interactions at the gas-liquid interface. The rapid release of latent heat from the steam and the turbulent mixing of the supercooled liquid drive a vigorous reorganization of the thermal boundary layer, while the formation and propagation of a condensation shock wave further enhances momentum transfer efficiency. In liquid oxygen-kerosene rocket engine systems, the direct contact condensation of gaseous oxygen and liquid oxygen within the liquid oxygen pump inter-tube is particularly crucial to the efficiency of the high-pressure regenerative combustion cycle. The condensation rate of gaseous oxygen directly affects the fluid density and pressure pulsation characteristics at the liquid oxygen pump inlet. The sensible and latent heat released during the phase change not only maintains the supercritical thermodynamic state of the turbine fluid but also ensures precise timing of the propellant supply to the combustion chamber by suppressing two-phase flow instabilities. This complex coupling mechanism involving multi-scale vortex structures, non-equilibrium thermodynamic responses and transient interface dynamics makes this process a key link in ensuring the thrust and reliability of liquid oxygen-kerosene engines. The suppression of condensation oscillation modes and the increase of flow instability thresholds have become core challenges in the design of advanced propulsion systems.

[0003] However, the intense interphase interaction between the steam jet and the cross-flowing supercooled water will induce a strong coupling effect of multiple physical fields: 1) The collapse of steam bubbles caused by the instability of the condensation interface will produce a transient pressure peak with an amplitude of kilopascals, causing high-frequency mechanical fatigue in the pipeline system; 2) The radiated noise caused by the instability of the gas-liquid interface has a frequency band covering 1-5000 Hz, which is prone to resonance threat with the natural frequency of the pipeline system; 3) The thermal shock load generated by the transient condensation process can cause hydrogen embrittlement failure of structural materials.

[0004] Current research focuses on the condensation characteristics of steam jets in large, static water environments. However, in actual industrial system operation, subcooled fluids are generally subjected to forced convection. Consequently, conventional large-scale water tank research systems are unable to replicate the shearing effect of cross-flowing subcooled water on steam jets, as well as the synergistic effects of factors such as the subcooled water Reynolds number and the injection point pressure on gas-liquid condensation behavior. This leads to increased errors in the prediction of jet length, condensation noise oscillation frequency, and heat transfer coefficient. Furthermore, existing experimental systems mostly focus on the pressure fluctuation characteristics of the condensation flow field, lacking quantitative characterization methods for condensation-induced noise radiation and structural vibration characteristics.

[0005] The existing Chinese patent with publication number CN114754965A provides a steam immersion jet experimental device containing non-condensable gas and its use method, which solves the problems that the existing technology cannot provide non-condensable gas, cannot be used for experiments on direct contact condensation phenomena, cannot provide stable steam jets with a certain flow rate and air content under large and small flow conditions, and cannot ensure sufficient mixing of the two gases and accurate collection of flow data. A steam immersion jet experimental device containing non-condensable gas is designed, including an electric heating boiler, an air compressor, a steam storage tank, an air supply branch, a main transport pipeline and a visual water tank. Stable mixing and flow control of steam and air are achieved through equipment such as vortex flowmeters, regulating valves and thermocouples, ensuring that stable jets are provided under different working conditions; the focus is on studying the condensation morphology and heat exchange characteristics of steam jets containing non-condensable gas in an open water tank, and solving the problem of gas-steam mixing uniformity solved by static mixers.

[0006] Therefore, it is urgent to develop high-parameter experimental equipment and multi-physics field measurement methods that can accurately simulate the dynamic interaction of cross-flow supercooled water-steam jets. Summary of the Invention

[0007] In response to the shortcomings of the existing technology, the present invention provides an experimental device and a multi-physical field measurement method for the direct contact condensation of a steam jet in a cross-flowing supercooled water flow in a tube, which can realize wide-range control of the flow rate and pressure of the supercooled working fluid, and simultaneously obtain multi-physical field data such as cross-scale gas-liquid interface dynamic behavior, broadband pressure spectrum, acoustic radiation energy field and structural vibration mode, so as to solve the difficulties in flow rate and pressure control of static working fluid experimental devices, as well as the problems of accurate laboratory reproduction and cross-scale synchronous measurement of condensation instability mechanism under dynamic conditions.

[0008] In order to achieve the above-mentioned objectives, in a first aspect, the present invention provides a testing device for condensation of gas-liquid two-phase jet in a pipe, wherein a water tank, a variable frequency pump, a solenoid valve, a mass flowmeter, a heater, and a visual test section are connected in sequence along the flow direction of the medium, and a pressure sensor and a thermocouple are provided on the pipeline from the solenoid valve to the mass flowmeter and the pipeline from the heater to the visual test section; the outlet of the visual test section is connected in sequence to the condenser, the solenoid valve, and the water tank, and a pressure sensor and a thermocouple are provided on the pipeline from the outlet of the visual test section to the condenser and the pipeline from the solenoid valve to the water tank; a deionized water tank, an electric heating boiler, a regulating valve, a vortex flowmeter, and a visual test section are connected in sequence along the flow direction of the medium, and a pressure sensor and a thermocouple are provided on the pipeline from the vortex flowmeter to the visual test section, and the visual test section is provided with a steam nozzle, a pressure sensor, a thermocouple, multiple hydrophones, an accelerometer, and an acoustic wave generator.

[0009] Furthermore, the outlet of the vortex flowmeter is connected to the nozzle inlet of the visualization test section; and the heater is connected to the supercooling medium flow channel inlet of the visualization test section.

[0010] Furthermore, the pressure sensor, thermocouple, mass flow meter, hydrophone, accelerometer, and vortex flowmeter are all connected to the data acquisition system.

[0011] Furthermore, the nozzle is connected to the visual test section through threads, and the remaining components are connected to the pipeline through flanges.

[0012] Furthermore, the main body of the visualization test section is a rectangular cross-section pressure-resistant cavity made of PC, with a transmittance of ≥92% and a pressure resistance grade of PN40.

[0013] Furthermore, a pulse laser, two holographic cameras, a blue laser light source, a blue laser beam splitter, and a reflector are arranged on the outside of the main body of the visualization test section; a blue laser beam splitter is arranged on the optical path of the blue laser light source, and a reflector is arranged on one optical path of the blue laser beam splitter. The reflector and the beam splitter are placed parallel to each other, and the angle between the beam splitter and the rear wall of the visualization test section is 45°.

[0014] Furthermore, high-pass filters are set at the pulse laser outlet and the microscope lens light inlet; a low-pass filter is set at the holographic camera light inlet, and the angles between the low-pass filter and the front wall and right wall of the visualization test section are 45° and 0° respectively. The angle between the high-pass filter in front of the pulse laser and the left wall of the visualization test section is 45°, and the high-pass filter in front of the microscope lens is parallel to the right wall of the visualization test section.

[0015] Furthermore, the acoustic wave generator on the visual test section is used to generate fixed or variable frequency acoustic waves, the hydrophone and pressure sensor are used to capture the acoustic waves and pressure fluctuations during the condensation and collapse of the gas-liquid jet, and the accelerometer collects the structural vibration information induced by gas-liquid condensation.

[0016] In a second aspect, the present invention provides an application of the above-mentioned test device for condensing the gas-liquid two-phase jet in the tube to simulate the flow state of industrial two-phase flow, which is used to simulate the condensation process of the two-phase fluid with high pressure, high Reynolds number and unsteady flow characteristics.

[0017] In a third aspect, the present invention provides a multi-physics field measurement method for gas-liquid two-phase jet condensation in a tube, based on the above-mentioned test device for gas-liquid two-phase jet condensation in a tube, comprising: Adjust the frequency of the variable frequency pump to make the flow rate of the supercooled medium in the pipe exceed the target flow rate. At this time, the solenoid valve is in the fully open state. Gradually reduce the opening of the solenoid valve at the end of the circulation pipeline to gradually reduce the flow rate of the supercooling medium and gradually increase the pressure; When the flow rate drops to the target value, observe whether the pressure reaches the target value. If so, the adjustment is complete. If not, continue to increase the frequency of the variable frequency pump and reduce the opening of the solenoid valve until both the flow rate and pressure reach the target value. Generate saturated steam through an electric heating boiler. After the flow rate and pressure of the subcooled medium are adjusted, the electric heating boiler is turned on. The boiler works periodically and is turned off when the saturated steam reaches the rated pressure. The mass flow rate of saturated steam is controlled by the nozzle diameter and the regulating valve, and the initial steam mass flow rate is set by the regulating valve opening. After the regulating valve opening is adjusted to the corresponding initial steam mass flow rate, its opening is fixed unchanged. Steam is freely released into the visual test section under the action of the pressure difference between the electric heating boiler and the visual test section. After the steam release is completed, the regulating valve, variable frequency pump and solenoid valve are closed in sequence.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: a test device for gas-liquid two-phase jet condensation in a tube provided by the present invention can simulate the actual working process of gas-liquid jet condensation in a confined space in a tube in the energy and power industry, filling the gap in the gas-liquid two-phase jet condensation experiment in the tube; by adopting a visual flow channel design of supercooled working fluid and combining it with a high-precision optical system, dynamic capture of the three-dimensional morphology of the gas-liquid two-phase jet is achieved; by adopting the coordinated control of a variable frequency pump and an electromagnetic valve, the flow rate and pressure of the supercooled working fluid are precisely adjusted to meet the experimental requirements of different working conditions; by constructing an optical path system and integrating a holographic camera, microscale particle image velocimetry technology, a pressure sensor, a hydrophone and an accelerometer, a multi-parameter coupled synchronous measurement system is constructed to achieve cross-scale synchronous measurement of the gas-liquid jet condensation phase interface, jet condensation velocity field, pressure field, acoustic field and structural vibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of a test device system for gas-liquid two-phase jet condensation in a tube according to the present invention; Figure 2 A schematic diagram of a visual test section of a test device for gas-liquid two-phase jet condensation in a tube according to the present invention; Figure 3 This is a top view of a visualized test section of a test device for gas-liquid two-phase jet condensation in a tube according to the present invention. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "one side", "one end", "one side", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0022] Reference Figure 1 As shown, a test device for gas-liquid two-phase jet condensation in a pipe includes a water storage tank 1, a variable frequency pump 2, a solenoid valve 3, a pressure sensor 4, a thermocouple 5, a mass flowmeter 6, a heater 7, a visual test section 8, a nozzle 9, a hydrophone 10, an accelerometer 11, an acoustic wave generator 12, a condenser 13, a deionized water tank 14, an electric heating boiler 15, a regulating valve 16, a vortex flowmeter 17, a data acquisition system 18 and a computer 19.

[0023] The water tank 1, variable frequency pump 2, solenoid valve 3, mass flowmeter 6, heater 7, and visual test section 8 are connected in sequence along the flow direction of the medium. A pressure sensor 4 and a thermocouple 5 are provided on the pipeline from the solenoid valve 3 to the mass flowmeter 6 and on the pipeline from the heater 7 to the visual test section 8; the outlet of the visual test section 8 is connected to the condenser 13, the solenoid valve 3, and the water tank 1 in sequence. A pressure sensor 4 and a thermocouple 5 are provided on the pipeline from the outlet of the visual test section 8 to the condenser 13 and on the pipeline from the solenoid valve 3 to the water tank 1.

[0024] The deionized water tank 14, the electric heating boiler 15, the regulating valve 16, the vortex flowmeter 17 and the visual test section 8 are connected in sequence along the flow direction of the medium. A pressure sensor 4 and a thermocouple 5 are provided on the pipeline from the vortex flowmeter 17 to the visual test section 8; the outlet of the vortex flowmeter 17 is connected to the inlet of the nozzle 9 of the visual test section 8; the heater 7 is connected to the inlet of the supercooled medium flow channel of the visual test section 8.

[0025] The pressure sensor 4 , the thermocouple 5 , the mass flowmeter 6 , the hydrophone 10 , the accelerometer 11 , and the vortex flowmeter 17 are all connected to a data acquisition system 18 , and the data acquisition system is connected to a computer 19 .

[0026] A water tank 1 and a variable frequency pump 2 are used to store and supply the supercooled working fluid at a variable speed. A solenoid valve 3 installed on the circulation pipeline is used to adjust the flow rate and pressure of the supercooled working fluid. A heater 7 is used to ensure the temperature of the supercooled working fluid. A pressure sensor 4, a thermocouple 5 and a mass flow meter 6 are used to monitor the pressure, temperature and flow of the supercooled working fluid, respectively. The supercooled working fluid returns to the water tank 1 after recovering excess heat through the condenser 13. Except for the pressure sensor 4 and the thermocouple 5, all the above components are connected to the supercooled working fluid circulation pipeline through flanges to ensure sealing and maintainability.

[0027] Purified deionized water is stored in a deionized water tank 14 and then passes through an electric boiler 15 to become saturated steam. A regulating valve 16 and a vortex flowmeter 17 are used to control and monitor steam flow, respectively. Furthermore, the steam pipeline is covered with an insulation layer to ensure that the steam remains saturated as it passes through the nozzle 9 and enters the visual test section 8. The nozzle 9 is connected to the visual test section 8 via threads, and the remaining components are connected to the pipeline via flanges.

[0028] Reference Figure 2 and Figure 3 As shown, the main body of the visualization test section 801 is a rectangular pressure-resistant cavity made of PC, 30mm thick, with a light transmittance of ≥92% and a pressure rating of PN40. Two holographic cameras 808 are placed on the front and side of the visualization test section 801 to capture the condensation behavior of the gas-liquid two-phase jet and reconstruct the spatiotemporal evolution characteristics of the three-dimensional gas-liquid interface. A blue laser light source 803 emits a 473nm wavelength of blue laser light, which is split into two beams by a beam splitter 806. The beam splitter 806 forms a 45° angle with the rear wall of the visualization test section 8. One beam is directed toward the holographic camera 808 on the front of the visualization test section 8, while the other beam is reflected by a reflector 805 to the holographic camera 808 on the side of the visualization test section 8. The reflector 805 is placed parallel to the beam splitter 806. The light inlet of the holographic camera 808 is fitted with a low-pass filter 807, ensuring that only blue light with a wavelength of 473 nm enters the lens. The low-pass filter 807 is positioned at 45° and 0° relative to the front and right walls of the visualization test section 8, respectively. The micro-PIV system 809 is used to analyze the turbulent vortex structure of the gas-liquid jet condensation flow field. Its background light source is a pulsed laser 802 with a wavelength of 532 nm. The tracer particles are fluorescent particles with a particle size of 0.5 μm, which, upon excitation, produce red light with a wavelength of 610 nm. A high-pass filter 804 is positioned at the light inlet of the microscope lens to ensure that red light enters the camera image. The high-pass filter 804 in front of the laser is positioned at a 45° angle relative to the left wall of the visualization test section 8, while the high-pass filter 804 in front of the microscope lens is parallel to the right wall of the visualization test section 8. Furthermore, the relative positions of all lenses, lasers, and optical components must be adjusted according to the size and quality of the desired flow field image.

[0029] A steam nozzle 9, a pressure sensor 4, a thermocouple 5, a plurality of hydrophones 10, an accelerometer 11 and an acoustic wave generator 12 are installed on one side wall of the visualization test section 8 from bottom to top. The acoustic wave generator 12 is used to generate fixed or variable frequency acoustic waves. The hydrophone 10 and the pressure sensor 4 are used to capture acoustic waves and pressure fluctuations in the condensation and collapse process of the gas-liquid jet. The structural vibration information induced by the gas-liquid condensation is collected through the accelerometer 11. The synchronization trigger ensures the cross-scale synchronous measurement of the dynamic behavior, pressure spectrum, sound field and vibration mode of the gas-liquid interface. The experimental data are transmitted to the computer 19 via the data acquisition system 18. The hydrophone 10 is a high-frequency hydrophone.

[0030] Before each experiment begins, the variable frequency pump 2 and the solenoid valve 3 are turned on to allow the supercooled liquid to circulate in the pipeline to avoid component damage due to the lack of cooling medium when steam is sprayed into the visual test section 8.

[0031] The flow rate and pressure of the supercooling medium need to be adjusted synchronously: first adjust the frequency of the variable frequency pump 2 so that the flow rate of the supercooling medium in the pipe is slightly greater than the target flow rate. At this time, the solenoid valve 3 is in the fully open state.

[0032] Next, gradually reduce the opening of solenoid valve 3 at the end of the circulation line to gradually reduce the flow rate of the subcooled medium and gradually increase the pressure. Finally, wait until the flow rate drops to the target value and observe whether the pressure reaches the target value. If it does, the adjustment is complete. If not, continue to increase the frequency of variable frequency pump 2 and reduce the opening of solenoid valve 3 until both the flow rate and pressure reach the target values.

[0033] Saturated steam is generated by the electric heating boiler 15. After the flow rate and pressure of the subcooled medium are adjusted, the electric heating boiler 15 is turned on. The boiler 15 works periodically and is shut down when the saturated steam reaches the rated pressure to prevent it from continuously producing steam.

[0034] The primary saturated steam parameter of interest in the experiment was mass flow rate, which was controlled by the nozzle 9 diameter and the regulating valve 16. When the nozzle 9 diameter and the regulating valve 16 opening are fixed, saturated steam at a specific temperature and pressure corresponds to a specific mass flow rate. Because the nozzle 9 diameter was fixed for each experiment, the initial steam mass flow rate was primarily set by the regulating valve 16 opening.

[0035] After the opening of regulating valve 16 is adjusted to the corresponding initial steam mass flow rate, its opening is fixed. Steam is freely released into the visual test section 8 due to the pressure difference between the electric heating boiler 15 and the visual test section 8. After the steam release is completed, regulating valve 16, variable frequency pump 2, and solenoid valve 3 are closed in sequence, and the experiment ends.

[0036] In summary, the present invention provides a test device for the condensation of a two-phase gas-liquid jet in a tube, which can simulate the actual working process of the condensation of a gas-liquid jet in a confined space in a tube in the energy and power industry. The device can be used to reproduce the high pressure, high Reynolds number and non-steady-state flow characteristics in typical industrial scenarios such as secondary steam injection of nuclear reactors and mixing of liquid rocket propellant pipelines through a modular flow channel structure and a multi-media compatible sealing system, filling the gap in the condensation experiment of a two-phase gas-liquid jet in a tube. It innovatively adopts a segmented temperature-pressure decoupling control strategy, so that the experimental section can maintain a precise gradient distribution of supercooling and independently adjust the local saturated vapor pressure, providing controllable boundary conditions for studying the evolution of condensation patterns during the transition from subcritical to supercritical states; by adopting a visual flow channel design for supercooled working fluids, combined with a high-precision optical system, dynamic capture of the three-dimensional morphology of the gas-liquid two-phase jet is achieved. The flow channel body utilizes refractive index matching technology integrated with a pressure-resistant optical window solution. This eliminates the refractive index difference between the multiphase flow medium and the transparent material, significantly reducing laser scattering distortion caused by the high-speed gas-liquid interface. Equipped with a dual-wavelength pulsed laser source coupled to a high-speed framing camera, combined with laser-induced fluorescence (LIF) and background schlieren (BOS) measurement techniques, it simultaneously tracks the topological evolution of the steam jet cavitation structure, microscale fluctuations in the subcooled liquid film, and the three-dimensional spatiotemporal characteristics of condensation shock wave propagation. The coordinated control of a variable-frequency pump and solenoid valve precisely regulates the flow rate and pressure of the subcooled fluid. A dynamic fluid parameter control system, based on a PID-PWM composite control algorithm, generates unsteady flow conditions such as step, ramp, and sinusoidal perturbations, effectively simulating transient condensation behavior during variable thrust regulation of rocket engines or load transients in nuclear power plants. A closed-loop feedback system automatically compensates for local temperature fluctuations caused by latent heat release during phase change by analyzing flow field characteristic parameters acquired by a multispectral sensor in real time, ensuring that the fluid's thermodynamic state evolves along a predetermined trajectory. By constructing an optical system and integrating a holographic camera, micro-PIV (microscale particle image velocimetry), a pressure sensor, a hydrophone, and a triaxial accelerometer, a multi-parameter coupled synchronous measurement system was constructed. The device innovatively uses a spectroscopic prism array and timestamp synchronous triggering technology to achieve nanosecond-level precision cross-physical field data fusion: the holographic camera captures the micron-level phase interface fluctuation characteristics, the micro-PIV analyzes the vortex transport law in the core area of ​​the jet, the high-frequency pressure sensor and the hydrophone quantify the condensation shock wave pressure pulsation spectrum characteristics and the cavitation noise characteristic spectrum respectively, and the triaxial accelerometer extracts the time-frequency coupling mode of the pipeline structure vibration and the condensation oscillation through the dynamic mode decomposition (DMD) algorithm. This multi-dimensional, cross-scale synchronous measurement capability provides a systematic experimental research device and method for revealing key scientific issues such as the phase interface instability mechanism and the interaction law between the condensation shock wave and the vortex structure during the condensation process of gas-liquid jets.

[0037] The above content is only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A test device for gas-liquid two-phase jet condensation in a tube, characterized in that: The water tank (1), the variable frequency pump (2), the solenoid valve (3), the mass flow meter (6), the heater (7), and the visual test section (8) are connected in sequence along the flow direction of the medium. A pressure sensor (4) and a thermocouple (5) are provided on the pipeline from the solenoid valve (3) to the mass flow meter (6) and the pipeline from the heater (7) to the visual test section (8); the outlet of the visual test section (8) is connected in sequence to the condenser (13), the solenoid valve (3), and the water tank (1). The pipeline from the outlet of the visual test section (8) to the condenser (13) and the pipeline from the solenoid valve (3) to the water tank (1) are connected in sequence. ) are provided on the pipelines; a deionized water tank (14), an electric heating boiler (15), a regulating valve (16), a vortex flowmeter (17) and a visual test section (8) are connected in sequence along the flow direction of the medium; a pressure sensor (4) and a thermocouple (5) are provided on the pipeline from the vortex flowmeter (17) to the visual test section (8); a steam nozzle (9), a pressure sensor (4), a thermocouple (5), a plurality of hydrophones (10), an accelerometer (11) and a sound wave generator (12) are provided on the visual test section (8).

2. The device for testing gas-liquid two-phase jet condensation in a tube according to claim 1, characterized in that: The outlet of the vortex flowmeter (17) is connected to the inlet of the nozzle (9) of the visual test section (8); and the heater (7) is connected to the inlet of the supercooling medium flow channel of the visual test section (8).

3. The device for testing gas-liquid two-phase jet condensation in a tube according to claim 1, characterized in that: The pressure sensor (4), the thermocouple (5), the mass flow meter (6), the hydrophone (10), the accelerometer (11), and the vortex flow meter (17) are all connected to the data acquisition system (18).

4. The device for testing gas-liquid two-phase jet condensation in a tube according to claim 1, characterized in that: The nozzle (9) is connected to the visual test section (8) through a threaded connection, and the remaining components are connected to the pipeline through a flange connection.

5. The device for testing gas-liquid two-phase jet condensation in a tube according to claim 1, characterized in that: The main body (801) of the visualization test section is a rectangular cross-section pressure-resistant cavity made of PC, with a light transmittance of ≥92% and a pressure resistance grade of PN40.

6. The device for testing gas-liquid two-phase jet condensation in a tube according to claim 1, characterized in that: A pulse laser (802), two holographic cameras (808), a blue laser light source (803), a blue laser beam splitter (806), and a reflector (805) are arranged outside the main body (801) of the visualization test section; a blue laser beam splitter (806) is arranged on the optical path of the blue laser light source (803); a reflector (805) is arranged on one optical path of the blue laser beam splitter (806); the reflector (805) and the beam splitter (806) are placed parallel to each other, and the angle between the beam splitter (806) and the rear wall of the visualization test section (8) is 45 degrees.

7. The device for testing gas-liquid two-phase jet condensation in a tube according to claim 6, characterized in that: A high-pass filter (804) is provided at the exit of the pulse laser (802) and the light inlet of the microscope lens; a low-pass filter (807) is provided at the light inlet of the holographic camera (808); the angles between the low-pass filter (807) and the front wall and the right wall of the visualization test section (8) are 45° and 0° respectively; the angle between the high-pass filter (804) in front of the pulse laser (802) and the left wall of the visualization test section (8) is 45°; and the high-pass filter (804) in front of the microscope lens is parallel to the right wall of the visualization test section (8).

8. The device for testing gas-liquid two-phase jet condensation in a tube according to claim 1, characterized in that: The acoustic wave generator (12) on the visual test section (8) is used to generate fixed or variable frequency acoustic waves, the hydrophone (10) and the pressure sensor (4) are used to capture the acoustic waves and pressure fluctuations during the condensation and collapse of the gas-liquid jet, and the accelerometer (11) collects structural vibration information induced by the gas-liquid condensation.

9. Application of the test device for gas-liquid two-phase jet condensation in a tube according to any one of claims 1 to 8 in simulating industrial two-phase flow regimes, characterized in that: Simulate the condensation process of two-phase fluids with high pressure, high Reynolds number and unsteady flow characteristics.

10. A multi-physics field measurement method for condensation of a gas-liquid two-phase jet in a tube, characterized in that: The testing device for gas-liquid two-phase jet condensation in a tube according to any one of claims 1 to 8 comprises: Adjust the frequency of the variable frequency pump (2) so that the flow rate of the supercooled medium in the pipe exceeds the target flow rate. At this time, the solenoid valve (3) is in the fully open state. Gradually reduce the opening of the solenoid valve (3) at the end of the circulation pipeline to gradually reduce the flow rate of the supercooling medium and gradually increase the pressure; After the flow rate drops to the target value, observe whether the pressure reaches the target value. If it does, the adjustment is completed. If not, continue to increase the frequency of the variable frequency pump (2) and reduce the opening of the solenoid valve (3) until both the flow rate and pressure reach the target value. Saturated steam is generated by an electric heating boiler (15), and after the flow rate and pressure of the subcooled medium are adjusted, the electric heating boiler (15) is turned on; the boiler (15) operates periodically and is turned off when the saturated steam reaches a rated pressure; The mass flow rate of saturated steam is controlled by the diameter of the nozzle (9) and the regulating valve (16), and the initial steam mass flow rate is set by the opening of the regulating valve (16). After the opening of the regulating valve (16) is adjusted to the corresponding initial steam mass flow rate, the opening is fixed and the steam is freely released into the visual test section (8) under the action of the pressure difference between the electric heating boiler (15) and the visual test section (8). After the steam release is completed, the regulating valve (16), the variable frequency pump (2) and the solenoid valve (3) are closed in sequence.

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