A separated break-out test device and a test method thereof

Abstract

The application relates to a separated break open jet release experimental device and an experimental method thereof, and relates to the fields of fluid mechanics and critical flow experimental research. In order to solve the problem that an existing break open simulation system cannot accurately study the pressure relief stage of a jet release process, the application comprises a jet release pipeline, a break open simulation module, a movable measurement module, a data acquisition system and a visual measurement system, adopts modular design and multiple break open simulation schemes, and enhances the applicability of the experimental device. A high-frequency high-temperature dynamic pressure sensor is used to measure the pressure change in the early pressure relief stage of the jet release process, a movable measurement system is designed outside the experimental section pipeline to measure the dynamic response of the back pressure of a jet release space environment, a high-speed camera is used to visually study jet release behaviors such as flashing and two-phase flow in the jet release process. The application is used for break open simulation experiments for pressure field measurement in the pressure relief stage of a jet release process and for jet release behavior observation.

Description

Technical Field

[0001] This invention relates to a burst simulation experimental device for measuring the pressure field and observing the discharge behavior during the depressurization stage of a discharge process, belonging to the field of fluid mechanics and critical flow experimental research. Background Technology

[0002] Piping system ruptures are a common type of failure in oil and gas, chemical, energy, and nuclear engineering fields. When a rupture occurs in a high-temperature, high-pressure piping system, the rapid release and depressurization of fluids often leads to severe accident consequences. In nuclear engineering, rupture accidents, also known as coolant loss accidents, are a type of design-basis accident. When a large rupture accident occurs, on the one hand, the large pressure gradient generates a pressure wave, and the propagation of this wave will impose a significant hydraulic load on the piping system. The resulting damage may further threaten the integrity of the reactor's primary loop pressure boundary. On the other hand, the rapid pressure drop and coolant loss, as well as the potential for backflow within the reactor depending on the location of the rupture, all lead to deterioration of heat transfer. Insufficient reactor cooling can result in even more severe accident consequences.

[0003] After the breach occurs, the fluid release process is a highly transient flow with inherent complexity. When the initial fluid parameters are high, the pressure relief process can result in two-phase flow and may also exhibit critical flow and other physical phenomena. Due to the drastic changes in physical parameters during the release flow, kinetic and thermodynamic imbalances exist, posing significant challenges to experimental measurements. Engineering applications focus on the fluid loss rate and the pressure relief rate of the loop system, corresponding to the measurement of flow rate and transient pressure.

[0004] Patents CN104505131A and CN104538067A disclose a break simulation system and measurement method for measuring two-phase discharge flow rate, as well as a detachable break simulation component used in this system. By combining a weighing method with a steam flow meter and utilizing a steam-water separator, the critical flow rate of the break discharge can be measured. The detachable break simulation component can simulate different break structures and sizes. However, this experimental system does not involve the measurement of pressure changes, and the weighing method requires a certain amount of time to measure the flow rate, thus not requiring precise and rapid break opening.

[0005] Experimental studies on the early depressurization stage of the discharge process only measured the pressure changes within the pipe, neglecting the impact of changes in ambient back pressure. Consequently, the boundary models established based on this approach often have undetermined empirical coefficients when used in relevant safety analysis programs. In actual numerical calculations, different values ​​for these empirical coefficients can cause the results to vary significantly, greatly affecting the accuracy of the safety analysis and the selection of safety margins.

[0006] In summary, existing breach simulation systems fail to measure changes in environmental back pressure, resulting in undetermined empirical coefficients in the closed model. Consequently, they cannot accurately study the depressurization phase of the discharge process. Summary of the Invention

[0007] The purpose of this invention is to address the problem that existing breach simulation systems, due to the lack of measurement of changes in environmental back pressure and the presence of undetermined empirical coefficients in the closed model, cannot accurately study the pressure relief phase of the discharge process. Therefore, this invention provides a separate breach discharge experimental apparatus and its experimental method.

[0008] The technical solution of the present invention is as follows: A separation-type burst ejection experimental device includes an ejection pipe, and further includes a burst simulation module, a movable measurement module, a data acquisition system, and a visualization measurement system. The end of the ejection pipe is connected to the burst simulation module. The movable measurement module is located in the atmospheric environment and is downstream of the burst simulation module. The environmental back pressure response at different locations during the ejection process is measured by adjusting the position of the pressure sensor on the movable measurement module. The data acquisition system is connected to the sensors on the ejection pipe and the movable measurement module respectively through data connection lines. The visualization measurement system observes and records the fluid ejection phenomenon through a high-speed projector located below the burst simulation module and the movable measurement module.

[0009] Furthermore, the discharge pipe includes a gate valve, a first thermocouple, a first pressure sensor, a second pressure sensor, a third pressure sensor, an exhaust valve, a fourth pressure sensor, a pipe body, and a second thermocouple. The gate valve is installed on the left end face of the pipe body. The first, second, third, and fourth pressure sensors are installed on the pipe body from left to right. The first and second thermocouples are installed on the left and right sides of the pipe body, respectively. The exhaust valve is installed on the pipe body to the left of the fourth pressure sensor. The outer wall of the pipe body is provided with a heat insulation layer.

[0010] Furthermore, the gate valve's flange is connected to an external heating and pressurizing water supply system.

[0011] Furthermore, the discharge pipe also includes multiple threaded pipe seats. The first thermocouple, the first pressure sensor, the second pressure sensor, the third pressure sensor, the fourth pressure sensor, and the second thermocouple are all installed on the pipe body through the threaded pipe seats, and the detection surfaces of the first pressure sensor, the second pressure sensor, the third pressure sensor, and the fourth pressure sensor are all tangent to the inner wall surface of the pipe body.

[0012] Furthermore, the rupture simulation module includes a flange, a sealing ring, a temperature- and pressure-resistant tempered glass sheet, and a safety hammer. The sealing ring is installed on both sides of the temperature- and pressure-resistant tempered glass sheet and embedded in the flange. The flange is installed on the right end face of the pipe body. The safety hammer is installed above the flange through a bracket, and the hammerhead of the safety hammer faces the temperature- and pressure-resistant tempered glass sheet.

[0013] Furthermore, the movable measurement module includes a bracket, multiple sliders, a guide rail with a scale, and several fifth pressure sensors. The bracket is installed downstream of the rupture simulation module, the guide rail is installed on the bracket, and the centerline of the guide rail is collinear with the axis of the pipe body. Multiple sliders are installed on the guide rail from left to right, and each slider is equipped with a fifth pressure sensor, which is installed in the internal thread of the slider.

[0014] Furthermore, the data acquisition system includes multiple data connection cables, a data acquisition module, and acquisition control software. The acquisition control software is installed in a computer, the data acquisition module is connected to the acquisition control software, one end of the multiple data connection cables is connected to the data acquisition module, and the other end of the multiple data connection cables is connected to a first thermocouple, a second thermocouple, a first pressure sensor, a second pressure sensor, a third pressure sensor, a fourth pressure sensor, and several fifth pressure sensors, respectively.

[0015] Furthermore, the visualization measurement system includes a high-speed camera, a data transmission cable, and shooting control software. The shooting control software is installed in a computer, and the high-speed camera is connected to the computer via the data transmission cable and transmits data to the shooting control software.

[0016] This invention also provides a method for a separation-type burst discharge experiment, which includes the following steps:

[0017] Step 1: Connect the experimental section pipeline to the existing pipeline system through the gate valve on the discharge pipeline. Control the electric heating boiler in the pipeline system according to the experimental conditions to obtain high temperature and high pressure water that meets the requirements. Check whether each instrument of the experimental device is normal, whether the valve is in the normal position, and whether the control software can work normally.

[0018] Step 2: Open the gate valve and control the valve opening to fill the spray pipe with water. At the same time, open the exhaust valve to discharge the original gas in the pipe. Observe the real-time measurement of the fluid pressure and temperature in the pipe by the acquisition system. When there is no obvious gas discharge from the exhaust valve, reduce the opening of the gate valve to further discharge the non-condensable gas in the pipe and preheat the experimental pipe section. When the temperature measured by the first thermocouple and the second thermocouple is the same and close to the set parameter value, close the exhaust valve and the gate valve in sequence.

[0019] Step 3: When the measured fluid pressure value inside the pipe body does not fluctuate significantly, turn on the high-speed camera of the data acquisition system and visualization measurement system to take pictures. Simulate the occurrence of a rupture on the pipe by using the rupture simulation module. Combined with the data acquisition system, obtain the transient pressure response of the first, second, third and fourth pressure sensors at different locations inside the pipe body. Use the fifth pressure sensor arranged on the guide rail in the movable measurement module to obtain the change curve of the environmental back pressure over time at different distances from the rupture. At the same time, use the high-speed camera to capture the flashing and flow process of the fluid outside the pipe.

[0020] Step 31: When the measured pressure of the fluid inside the discharge pipe approaches the ambient pressure, stop the data acquisition system and the high-speed camera from taking pictures;

[0021] Step 32: When the equipment temperature drops to near the ambient temperature, reset the break simulation module. If a repeatable experiment is to be performed, repeat the above steps. If an experiment is to be performed under other operating conditions, adjust the heating boiler to obtain water that meets the requirements and then repeat the above steps until the break discharge experiment is completed.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The separable burst discharge experimental device provided by this invention separates a section of the entire loop system, 109, for experimentation, thus achieving loop system separation. By selecting and using experimental devices with different geometric parameters, it facilitates research on burst discharge experiments under different characteristic dimensions and operating conditions. This invention, by timely bursting the burst simulation module 2, can simulate the early rapid pressure relief process in a burst accident. Using a high-frequency dynamic pressure transmitter, the pressure change characteristics of this strong transient process are obtained. Accurate measurement of the pressure response helps to reproduce and understand the physical process of the discharge, develop closed models, provide a foundation for research on subsequent stages of burst accidents, and provide data support for the development and verification of corresponding system analysis programs.

[0024] 2. This invention adopts a modular design concept to enhance its applicability to different working conditions. Connection methods such as flanges and threads can be easily replaced. It is suitable for sensors with different pressure and temperature conditions. Different implementation schemes of the break simulation module can explore the influence of break area and break opening time on the discharge process.

[0025] 3. This invention designs a movable measurement module 3. The guide rail 302 of the movable measurement module 3 is parallel to the axis of the pipe body 109 and can move in the radial direction. The slider 301 on the guide rail 302 can move along the track. Before each experiment, the radial position of the guide rail and the axial position of the slider are fixed. By changing the position coordinates of the guide rail and the slider under the same working conditions, multiple measurements are performed. Combining the axisymmetric characteristics of the ejection flow field, a three-dimensional pressure field of environmental back pressure changing with time is obtained. The movable measurement design greatly reduces the number of sensors used and also reduces the influence of the sensors on the flow field during measurement. Under the same experimental conditions, by moving the measuring rod in a plane perpendicular to the flow direction, a three-dimensional pressure field changing with time can be obtained. This needs to be described in conjunction with the structural features in this application.

[0026] 4. This invention provides a visualization measurement system that can acquire the discharge area and observe and study the flash vaporization changes, two-phase flow, and discharge behavior during the discharge process. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the system structure of the present invention.

[0028] Figure 2 This is a structural diagram of the movable data acquisition module. Detailed Implementation

[0029] Specific implementation method one: Combining Figures 1 to 2 This embodiment describes a separation-type burst ejection experimental device, which includes a ejection pipe 1, a burst simulation module 2, a movable measurement module 3, a data acquisition system, and a visualization measurement system. The end of the ejection pipe 1 is connected to the burst simulation module 2. The movable measurement module 3 is located in the atmospheric environment and is downstream of the burst simulation module 2. The pressure response of the environmental back pressure at different locations during the ejection process is measured by adjusting the position of the pressure sensor 303 on the movable measurement module 3. The data acquisition system is connected to the sensors on the ejection pipe 1 and the movable measurement module 3 via data connection lines. The visualization measurement system observes and records the fluid ejection phenomenon through a high-speed projector 501 located below the burst simulation module 2 and the movable measurement module 3.

[0030] This invention enables the measurement and study of the transient response characteristics of fluid depressurization and discharge at different locations inside the pipe body 109 after a pipeline system rupture, through multiple pressure sensors on the discharge pipe 1; the spatial distribution and transient response characteristics of environmental back pressure through multiple pressure sensors on the movable measurement module 3; and the discharge behavior such as flash evaporation process and two-phase flow of high-temperature and high-pressure water.

[0031] Furthermore, experimental research is needed on the early depressurization stage of the discharge process. In actual numerical calculations, different empirical coefficient values ​​can cause the calculation results to vary significantly, greatly affecting the accuracy of safety analysis and the selection of safety margins. The data acquisition system and high-frequency pressure sensor of this invention enable more precise measurements during rapidly changing processes, allowing for a more accurate study of the depressurization stage of the discharge process.

[0032] Specific Implementation Method Two: Combining Figure 1 This embodiment describes a discharge pipe 1 comprising a gate valve 101, a first thermocouple 106, a first pressure sensor 102, a second pressure sensor 103, a third pressure sensor 104, an exhaust valve 108, a fourth pressure sensor 105, a pipe body 109, and a second thermocouple 107. The gate valve 101 is installed on the left end face of the pipe body 109. The first pressure sensor 102, the second pressure sensor 103, the third pressure sensor 104, and the fourth pressure sensor 105 are installed on the pipe body 109 from left to right. The first thermocouple 106 and the second thermocouple 107 are respectively installed on the left and right sides of the pipe body 109. The exhaust valve 108 is installed on the pipe body 109 to the left of the fourth pressure sensor 105. The outer wall of the pipe body 109 is provided with a heat insulation layer.

[0033] With this configuration, the outer wall insulation layer of the pipe body 109 is made of polyurethane insulation material, and this insulation layer wraps around the outer wall of the pipe. Other components and connections are the same as in Specific Embodiment 1.

[0034] In this embodiment, the insulation layer is made of polyurethane material with a thermal conductivity of less than 0.024 W / (m·K), and completely covers the area of ​​the discharge pipe except for the sensor connection pipe seat.

[0035] Specific implementation method three: Combining Figure 1 In this embodiment, the flange of the gate valve 101 is connected to an external heating and pressurizing water supply system. With this configuration, the gate valve is connected to one side of the discharge pipe 1 via its own flange, and the other side of the gate valve is connected to the heating and pressurizing water supply system via a flange, used to obtain the working fluid for the parameters required in the experiment. Other components and connections are the same as in specific embodiments one or two.

[0036] Optionally, by adjusting the fixed support of the discharge pipe 1, a certain height difference is formed between the upstream inlet of the pipe and the downstream discharge outlet, which facilitates the discharge of non-condensable gases when water is added to the pipe, and the discharge of the remaining liquid after the discharge experiment is completed.

[0037] Specific implementation method four: Combination Figure 1In this embodiment, the discharge pipe 1 further includes multiple threaded pipe seats. The first thermocouple 106, the first pressure sensor 102, the second pressure sensor 103, the third pressure sensor 104, the fourth pressure sensor 105, and the second thermocouple 107 are all installed on the pipe body 109 through the threaded pipe seats, and the detection surfaces of the first pressure sensor 102, the second pressure sensor 103, the third pressure sensor 104, and the fourth pressure sensor 105 are all tangent to the inner wall surface of the pipe body 109.

[0038] In this configuration, the discharge pipes 1 are all connected to pressure sensors and thermocouples via threaded pipe seats welded to the pipe wall. The first pressure sensor 102, second pressure sensor 103, third pressure sensor 104, and fourth pressure sensor 105 each have external threaded connectors. After wrapping Teflon tape around the threaded connectors, they are screwed into the internally threaded welded pipe seats. The first thermocouple 106 and second thermocouple 107 are connected to the externally threaded pipe seats using nuts and seals. The detection surfaces of all sensors are flush with the inner wall of the pipe. Other components and connections are the same as in specific embodiments one, two, or three.

[0039] The first, second, third, and fourth pressure sensors are high-frequency, high-temperature dynamic pressure transmitters with a maximum sampling frequency of 10kHz, enabling high-frequency measurement of fluid pressure. Each pressure sensor has a built-in threaded connector, which is wound with Teflon tape and then screwed into a welded socket with internal threads on the pipe wall. The first and second thermocouples are type K thermocouples, designed to measure the temperature of the fluid in the discharge pipe before discharge, and are connected to the welded socket on the pipe wall using nuts and seals. The measuring faces of the pressure sensors and thermocouples are tangent to the inner wall of the discharge pipe.

[0040] Optionally, the first, second, third, and fourth pressure sensors are sequentially arranged on the discharge pipe, wherein the first and fourth pressure sensors are located near the pipe inlet and outlet, respectively; the second pressure sensor is located between the first and fourth pressure sensors; and the third pressure sensor is located between the second and fourth pressure sensors. The first and second thermocouples are located at the same cross-sectional position on the pipe as the first and fourth pressure sensors, respectively, and are situated on the horizontal section containing the pipe axis.

[0041] Specific Implementation Method Five: Combining Figure 1This embodiment describes a breach simulation module 2 comprising a flange 201, a sealing ring, a temperature- and pressure-resistant tempered glass sheet 202, and a safety hammer 203. The sealing ring is installed on both sides of the temperature- and pressure-resistant tempered glass sheet 202 and embedded in the flange 201. The flange 201 is installed on the right end face of the pipe body 109. The safety hammer 203 is installed above the flange 201 via a bracket, with the hammerhead of the safety hammer 203 facing the temperature- and pressure-resistant tempered glass sheet 202.

[0042] In this configuration, the safety hammer is fixed with a bracket. By adjusting the release height of the safety hammer, gravity is converted into kinetic energy to shatter the thin glass sheet, thus simulating the formation of a break. Other components and connections are the same as in specific implementation methods one, two, three, or four.

[0043] Alternatively, the tempered glass plate and safety hammer in the fracture simulation module can be replaced by a pneumatic quick-opening ball valve or a pneumatic quick-opening butterfly valve. The full opening time of the pneumatic quick-opening valve can be controlled within 1 second. The tempered glass plate and safety hammer can also be replaced by a rupture disc or a rupture valve, in which case the simulated fracture opening time can reach the order of milliseconds.

[0044] Specific Implementation Method Six: Combination Figure 1 and Figure 2 This embodiment describes a movable measuring module 3 comprising a bracket, multiple sliders 301, a guide rail 302 with a scale, and several fifth pressure sensors 303. The bracket is installed downstream of the rupture simulation module 2, the guide rail 302 is mounted on the bracket, and the centerline of the guide rail 302 is collinear with the axis of the pipe body 109. The multiple sliders 301 are sequentially mounted on the guide rail 302 from left to right, and each slider 301 is equipped with a fifth pressure sensor 303, which is installed in the internal thread of the slider 301.

[0045] In this configuration, the pressure sensor uses the same high-frequency, high-temperature dynamic pressure transmitter as the one used on the breached pipe. It is threaded onto the slider and flush with its upper surface. The sliders are placed sequentially on guide rails, which are fixed by brackets to ensure parallelism between the guide rails and the axis of the discharge pipe. Furthermore, the surface of the slider with the sensor is tangent to the flow direction of the discharged fluid. The pressure sensor transmitter and data cables are covered with high-temperature resistant, waterproof material, and the area of ​​the baffle on the flow-facing surface of the guide rails is minimized. Other components and connections are the same as in specific implementation methods one, two, three, four, or five.

[0046] Specific implementation method seven: Combination Figure 1This embodiment describes a data acquisition system that includes multiple data connection cables 402, a data acquisition module 401, and acquisition control software 403. The acquisition control software 403 is installed in a computer. The data acquisition module 401 is connected to the acquisition control software 403. One end of each of the multiple data connection cables 402 is connected to the data acquisition module 401, and the other end of each of the multiple data connection cables 402 is connected to a first pressure sensor 102, a second pressure sensor 103, a third pressure sensor 104, a fourth pressure sensor 105, and several fifth pressure sensors 303, respectively.

[0047] In this configuration, the data connection cable is used to connect the pressure sensor, thermocouple, and data acquisition module, transmitting the measurement signal to the acquisition module. The data acquisition module includes an isolated thermocouple acquisition card and a voltage signal acquisition card. Parameter setting and control during the acquisition process are implemented through accompanying software on the computer. Other components and connections are the same as in specific implementation methods one, two, three, four, five, or six.

[0048] Specific implementation method eight: Combination Figure 1 This embodiment describes a visualization measurement system that includes a high-speed camera 501, a data transmission line 502, and shooting control software 503. The shooting control software 503 is installed in a computer, and the high-speed camera 501 is connected to the computer via the data transmission line 502 and transmits data to the shooting control software 503.

[0049] With this setup, the data cable connects the high-speed camera to the computer, and the shooting process is controlled via the accompanying software on the computer. Other components and connections are the same as in specific implementation methods one, two, three, four, five, six, or seven.

[0050] Specific Implementation Method Nine: Combining Figure 1 and Figure 2 This embodiment describes an experimental method for a separation-type burst discharge experimental device, which includes the following steps:

[0051] Step 1: Connect the experimental section pipeline to the existing pipeline system through the gate valve 101 on the discharge pipeline 1. Control the electric heating boiler in the pipeline system according to the experimental conditions to obtain high temperature and high pressure water that meets the requirements. Check whether each instrument of the experimental device is normal, whether the valve is in the normal position, and whether the control software can work normally.

[0052] Step 2: Open gate valve 101 and control the valve opening to fill the spray pipe with water. At the same time, open exhaust valve 108 to discharge the original gas in the pipe. Observe the fluid pressure and temperature values ​​in the pipe measured in real time by the acquisition system. When there is no obvious gas discharge from exhaust valve 108, reduce the opening of gate valve 101 to further discharge non-condensable gas in the pipe and preheat the experimental pipe section. When the temperatures measured by the first thermocouple 106 and the second thermocouple 107 are the same and close to the set parameter values, close exhaust valve 108 and gate valve 101 in sequence.

[0053] Step 3: When the measured fluid pressure value inside the pipe body 109 does not fluctuate significantly, the high-speed camera 501 of the data acquisition system and visualization measurement system is turned on to take pictures. The occurrence of a rupture on the pipe is simulated by the action of the rupture simulation module 2. Combined with the data acquisition system, the transient pressure response of the first pressure sensor 102, the second pressure sensor 103, the third pressure sensor 104 and the fourth pressure sensor 105 at different positions inside the pipe body 109 is obtained. The fifth pressure sensor 303 arranged on the guide rail 302 in the movable measurement module 3 is used to obtain the change curve of the environmental back pressure over time at different distances from the rupture. At the same time, the high-speed camera 501 is used to take pictures of the flashing and flow process of the fluid outside the pipe.

[0054] Step 31: When the measured pressure of the fluid inside the discharge pipe approaches the ambient pressure, stop the data acquisition system and the high-speed camera from taking pictures;

[0055] Step 32: When the equipment temperature drops to near the ambient temperature, reset the break simulation module 2. If a repeatable experiment is to be performed, repeat the above steps. If an experiment is to be performed under other operating conditions, adjust the heating boiler to obtain water that meets the requirements and then repeat the above steps until the break discharge experiment is completed.

[0056] Other components and connections are the same as any one of the specific embodiments one to eight.

[0057] Combination Figures 1 to 2 Description of embodiments of the present invention:

[0058] like Figure 1As shown, a separation-type burst ejection experimental device includes an ejection pipe 1, a burst simulation module 2, a movable measurement module 3, a data acquisition system, and a visualization measurement system. The ejection pipe 1 is connected to the burst simulation module 2 via a flange. The movable measurement module 3 is located downstream of the burst simulation module. The sensors in the experimental device are connected to the data acquisition system via data connection lines. The visualization measurement system is independent of the other devices and observes and records the fluid ejection phenomenon through high-speed photography. The main body of the discharge pipe 1 is a 304 stainless steel pipe conforming to industrial standards. It includes a gate valve 101, a first thermocouple 106, a first pressure sensor 102, a second pressure sensor 103, a third pressure sensor 104, an exhaust valve 108, a fourth pressure sensor 105, and a second thermocouple 107. These components are sequentially arranged on the discharge pipe. The outer wall of the pipe is covered with polyurethane insulation material as a heat insulation layer. The gate valve 101 is connected to one side of the discharge pipe via its own flange, and the other side is connected to the heating and pressurizing water supply system via a flange, used to obtain the working fluid for the required experimental parameters. By adjusting the fixed support below the discharge pipe 1, a certain height difference is created between the upstream inlet and the downstream discharge outlet of the pipe. This facilitates the discharge of non-condensable gases during water replenishment and the discharge of remaining liquid after the experiment. The fixed support is not shown in the figure. The first pressure sensor 102, the second pressure sensor 103, the third pressure sensor 104, and the fourth pressure sensor 105 are high-frequency, high-temperature dynamic pressure transmitters with a maximum sampling frequency of 10kHz, capable of high-frequency measurement of fluid pressure. The pressure sensors have built-in threaded connectors, which are screwed into the welded pipe seat with internal threads after being wrapped with Teflon tape. The first thermocouple 106 and the second thermocouple 107 are type K thermocouples, which are used to measure the temperature of the fluid in the discharge pipe under stable conditions before discharge. They are connected to the welded pipe seat on the pipe wall using nuts and seals. The measuring ends of the pressure sensors and thermocouples are tangent to the inner wall of the discharge pipe, so they will not affect the flow of fluid inside the pipe. The pressure sensor requires an additional DC power supply for input. When the temperature of the measured medium is high, additional cooling water is required for cooling. The power supply and matching cooling water system of the pressure sensor are not shown in the figure.

[0059] Figure 1The break simulation module 2 includes a flange 201, sealing rings, a temperature- and pressure-resistant tempered glass sheet 202, and a safety hammer 203. Sealing rings are placed on both sides of the glass sheet 202, and it is connected and fixed to the flange on the discharge pipe by the flange 201. The safety hammer 203 is fixed with a bracket. By adjusting its release height, it relies on gravity to convert work into kinetic energy to break the glass sheet 202, thus simulating the formation of a break. The fixing bracket for the safety hammer is not shown in the figure. By selecting flanges of different diameters and glass sheets of different diameters, breaks of different sizes can be simulated. The data acquisition system includes a data connection cable 402, a data acquisition module 401, and acquisition control software 403. The data connection cable 402 is used to connect the pressure sensor, thermocouple, and data acquisition module 401, transmitting the measurement signal to the acquisition module. The data acquisition module 401 includes an isolated thermocouple acquisition card and a voltage signal acquisition card. Parameter setting and control during the acquisition process are achieved through the accompanying software on the computer. The visualization measurement system includes a high-speed camera 501, a data cable 502, and shooting control software 503. The data cable is used to connect the high-speed camera 501 to the computer, and the shooting process is controlled by the accompanying software within the computer.

[0060] like Figure 1 and Figure 2 As shown, the movable measurement module 3 includes a baffle, a bracket, a guide rail 302 with a scale, a slider 301 with an internally threaded through hole, and several pressure sensors 303. The pressure sensors use the same high-frequency, high-temperature dynamic pressure transmitters as those on the breached pipe, which are threaded onto the slider and flush with its upper surface. The sliders 301 are placed sequentially on the guide rail 302, which is fixed by the bracket to ensure that the guide rail and the axis of the discharge pipe are parallel, and that the surface of the slider with the sensor is tangent to the flow direction of the discharged fluid. The pressure sensors and data cables are covered with high-temperature resistant and waterproof material to isolate the discharged fluid and reduce the area of ​​the baffle on the guide rail's flow-facing surface to minimize its impact on the flow field. The fixed bracket, baffle, and pressure sensors are not shown in the figure.

[0061] An experimental method based on the above-described separation-break ejection experimental device:

[0062] Step 1: Connect the experimental section pipeline to the existing pipeline system through the gate valve 101 on the discharge pipeline 1. Control the electric heating boiler in the pipeline system according to the experimental conditions to obtain high temperature and high pressure water that meets the requirements. Check whether each instrument of the experimental device is normal, whether the valve is in the normal position, and whether the control software can work normally.

[0063] Step 2: Open gate valve 101 and control the valve opening to fill the spray pipe with water. At the same time, open exhaust valve 108 to discharge the original gas in the pipe. Observe the fluid pressure and temperature values ​​in the pipe measured in real time by the acquisition system. When there is no obvious gas discharge from exhaust valve 108, reduce the opening of gate valve 101 to further discharge non-condensable gas in the pipe and preheat the experimental pipe section. When the temperatures measured by the first thermocouple 106 and the second thermocouple 107 are basically the same and close to the set parameter value, close exhaust valve 108 and gate valve 101 in sequence.

[0064] Step 3: When the measured fluid pressure value inside the pipe does not fluctuate significantly, start data acquisition and high-speed camera shooting. Simulate the occurrence of a pipe rupture by using the rupture simulation module 2. Combined with the data acquisition system, obtain the transient pressure response of the first pressure sensor 102, the second pressure sensor 103, the third pressure sensor 104 and the fourth pressure sensor 105 at different locations inside the pipe. Use the pressure sensor 303 arranged on the guide rail 302 in the movable measurement module 3 to obtain the change curve of the environmental back pressure over time at different distances from the rupture. At the same time, use the high-speed camera 501 to shoot the flashing and flow process of the fluid outside the pipe.

[0065] When the measured pressure of the fluid inside the discharge pipe approaches the ambient pressure, the data acquisition system and the high-speed camera stop recording.

[0066] When the equipment temperature drops to near the ambient temperature, reset the break simulation module 2. If a repeatable experiment is to be performed, repeat the above steps. If an experiment is to be performed under other operating conditions, adjust the heating boiler to obtain water that meets the requirements and then repeat the above steps.

[0067] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make other changes within the spirit of the invention and apply it to fields not mentioned in the invention. Of course, all such changes made in accordance with the spirit of the invention should be included within the scope of protection claimed by the invention.

Claims

1. A separation-type burst discharge experimental device, comprising a discharge pipe (1), characterized in that: It also includes a breach simulation module (2), a movable measurement module (3), a data acquisition system, and a visualization measurement system. The end of the discharge pipe (1) is connected to the break simulation module (2). The movable measurement module (3) is located in the atmospheric environment and is downstream of the break simulation module (2). The environmental back pressure response at different locations during the discharge process is measured by adjusting the position of the pressure sensor (303) on the movable measurement module (3). The data acquisition system is connected to the sensors on the discharge pipe (1) and the movable measurement module (3) respectively via data connection lines. The visualization measurement system realizes the observation and recording of the fluid discharge phenomenon through the high-speed camera (501) located on the underside of the break simulation module (2) and the movable measurement module (3). The discharge pipe (1) includes a gate valve (101), a first thermocouple (106), a first pressure sensor (102), a second pressure sensor (103), a third pressure sensor (104), an exhaust valve (108), a fourth pressure sensor (105), a pipe body (109), a second thermocouple (107), and multiple threaded pipe seats. A gate valve (101) is installed on the left end face of the pipe body (109). The first pressure sensor (102), the second pressure sensor (103), the third pressure sensor (104) and the fourth pressure sensor (105) are installed on the pipe body (109) from left to right. The first thermocouple (106) and the second thermocouple (107) are installed on the left and right sides of the pipe body (109) respectively. The exhaust valve (108) is installed on the pipe body (109) to the left of the fourth pressure sensor (105). The outer wall of the pipe body (109) is provided with a heat insulation layer. The first thermocouple (106), the first pressure sensor (102), the second pressure sensor (103), the third pressure sensor (104), the fourth pressure sensor (105), and the second thermocouple (107) are all mounted on the pipe body (109) through threaded pipe seats, and the detection surfaces of the first pressure sensor (102), the second pressure sensor (103), the third pressure sensor (104), and the fourth pressure sensor (105) are all tangent to the inner wall surface of the pipe body (109); The break simulation module (2) includes a flange (201), a sealing ring, a temperature and pressure resistant tempered glass sheet (202), and a safety hammer (203). The sealing ring is installed on both sides of the temperature and pressure resistant tempered glass sheet (202) and embedded in the flange (201). The flange (201) is installed on the right end face of the pipe body (109). The safety hammer (203) is installed above the flange (201) through a bracket, and the hammer head of the safety hammer (203) faces the temperature and pressure resistant tempered glass sheet (202).

2. The experimental apparatus for separating bursts and ejections according to claim 1, characterized in that: The flange of the gate valve (101) is connected to the external heating and pressurization water supply system.

3. The experimental apparatus for separating bursts and ejections according to claim 2, characterized in that: The movable measurement module (3) includes a bracket, multiple sliders (301), a guide rail (302) with a scale, and several fifth pressure sensors (303). The bracket is installed downstream of the rupture simulation module (2), the guide rail (302) is installed on the bracket, and the center line of the guide rail (302) is collinear with the axis of the pipe body (109). Multiple sliders (301) are installed on the guide rail (302) from left to right. Each slider (301) is equipped with a fifth pressure sensor (303), and the fifth pressure sensor (303) is installed in the internal thread on the slider (301).

4. The experimental apparatus for separating burst discharge according to claim 3, characterized in that: The data acquisition system includes multiple data connection cables (402), a data acquisition module (401), and acquisition control software (403). The acquisition control software (403) is installed in a computer. The data acquisition module (401) is connected to the acquisition control software (403). One end of the multiple data connection cables (402) is connected to the data acquisition module (401), and the other end of the multiple data connection cables (402) is connected to the first thermocouple (106), the second thermocouple (107), the first pressure sensor (102), the second pressure sensor (103), the third pressure sensor (104), the fourth pressure sensor (105), and several fifth pressure sensors (303), respectively.

5. The experimental apparatus for separating burst discharge according to claim 4, characterized in that: The visualization measurement system includes a high-speed camera (501), a data transmission line (502), and shooting control software (503). The shooting control software (503) is installed in a computer. The high-speed camera (501) is connected to the computer via the data transmission line (502) and transmits data to the shooting control software (503).

6. An experimental method using the separation burst ejection experimental apparatus according to any one of claims 1 to 5, characterized in that: It includes the following steps: Step 1: Connect the experimental section pipeline to the existing pipeline system through the gate valve (101) on the discharge pipeline (1), control the electric heating boiler in the pipeline system according to the experimental conditions, obtain high temperature and high pressure water that meets the requirements, check whether each instrument of the experimental device is normal, whether the valve is in the normal position, and whether the control software can work normally. Step 2: Open the gate valve (101) and control the valve opening to fill the spray pipe with water. Open the exhaust valve (108) to discharge the original gas in the pipe. At the same time, observe the fluid pressure and temperature values ​​in the pipe measured in real time by the acquisition system. When there is no obvious gas discharge from the exhaust valve (108), reduce the opening of the gate valve (101) to further discharge the non-condensable gas in the pipe and preheat the experimental pipe section. When the temperatures measured by the first thermocouple (106) and the second thermocouple (107) are the same and close to the set parameter values, close the exhaust valve (108) and the gate valve (101) in sequence. Step 3: When the measured fluid pressure value inside the pipe body (109) does not fluctuate significantly, turn on the high-speed camera (501) of the data acquisition system and visualization measurement system to take pictures. The rupture simulation module (2) simulates the occurrence of a rupture on the pipe. Combined with the data acquisition system, the transient pressure response of the first pressure sensor (102), the second pressure sensor (103), the third pressure sensor (104) and the fourth pressure sensor (105) at different locations inside the pipe body (109) is obtained. Several fifth pressure sensors (303) arranged on the guide rail (302) in the movable measurement module (3) are used to obtain the change curve of the environmental back pressure with time at different distances from the rupture. At the same time, the high-speed camera (501) is used to take pictures of the flashing and flow process of the fluid outside the pipe. Step 31: When the measured pressure of the fluid inside the discharge pipe approaches the ambient pressure, stop the data acquisition system and the high-speed camera from taking pictures; Step 32: When the equipment temperature drops to near the ambient temperature, reset the break simulation module (2). If a repeatable experiment is to be conducted, repeat the above steps. If an experiment is to be conducted under other operating conditions, adjust the heating boiler to obtain water that meets the requirements and then repeat the above steps until the break discharge experiment is completed.

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