A back pressure type device for capturing two-phase jet shape under break-loose accident

Abstract

This invention discloses a two-phase jet morphology capture device under a backpressure rupture accident, comprising a high-pressure water tank, a heating rod, a plunger pump, a quick-opening valve, a test nozzle, a visualization backpressure container, an exhaust valve, a backpressure valve, and a high-speed camera. First, the plunger pump pressurizes the high-pressure water tank, and the built-in heating rod heats the medium inside the tank. The jet is then discharged via a quick-opening valve. A visualization backpressure container is used, and the high-speed camera captures the morphology of the rupture jet within the container, transmitting the data to a computer. The test nozzle is located inside the visualization backpressure container. Two backpressure valves are installed at the lower end of the container, and the backpressure inside the container is adjusted by the valve opening to meet the high backpressure test requirements. An exhaust valve is installed at the top of the container to precisely adjust the backpressure and discharge phase-change vapor, reducing the gas content and further lowering the backpressure.

Description

Technical Field

[0001] This invention relates to the field of nuclear reactor large-break accident jet impact test technology, and particularly to a two-phase jet morphology capture device under a break accident with back pressure. Background Technology

[0002] During reactor operation, high-temperature, high-pressure water is ejected through breaches or cracks of varying sizes. Due to the high velocity of the water under high pressure and the accompanying phase change, it exerts a significant impact force on objects, even causing cutting, seriously threatening the safety of nuclear power plant operation. Therefore, studying the morphological changes of jets under high temperature and pressure is of great significance for reactor safety.

[0003] Currently, scholars both domestically and internationally have conducted extensive and in-depth research on high-pressure single-phase water or gas jets in terms of theoretical models, but most of the research remains at atmospheric pressure and lacks research on jet morphology under different back pressure conditions. Furthermore, due to the complexity and difficulty of high-pressure and high-temperature medium experiments, there has been little research and exploration of liquid jet technology under high parameters. Therefore, it is essential to further explore the morphology of high-temperature and high-pressure jets, building upon the work of our predecessors. Based on this, a device for capturing changes in the morphology of two-phase leakage jets under back pressure conditions was designed to fill the gaps in high-temperature and high-pressure jet morphology and flow data under different back pressure conditions in nuclear reactors. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention aims to provide a two-phase jet morphology capture device under back pressure failure conditions, which can capture the jet morphology under high back pressure conditions in failure failures, filling the research gap in two-phase jet experiments.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A two-phase jet morphology capture device under a back-pressure rupture accident includes a high-pressure water tank 4, a heating rod 5, a plunger pump 9, a quick-opening valve 11, a test nozzle 13, a visualization back-pressure container 14, an exhaust valve 15, a back-pressure valve 16, and a high-speed camera 19. The high-pressure water tank 4 is connected to a water storage tank 10 via the plunger pump 9. The plunger pump 9 injects water from the water storage tank 10 into the high-pressure water tank 4 to pressurize it. The heating rod 5 inside the high-pressure water tank 4 heats the water inside the high-pressure water tank. The test nozzle 13 is connected to the high-pressure water tank (4) via the quick-opening valve 11. The test nozzle 13 is located inside the visualization back-pressure container 14. The quick-opening valve 11 is used to connect the high-pressure water tank (4). High-pressure water is sprayed through test nozzle 13 to simulate a burst jet. A visual back pressure container 14 is used, and the morphology of the burst jet inside the visual back pressure container is captured by a high-speed camera 19. The data is transmitted to a computer host 18 connected to the high-speed camera 19. Two back pressure valves 16 are set at the lower end of the visual back pressure container. The back pressure inside the visual back pressure container is adjusted by adjusting the opening of the back pressure valves 16. At the same time, the dual-pipe drainage design makes the back pressure adjustment range large, which meets the test requirements of high back pressure. An exhaust valve 15 is set at the top of the visual back pressure container to achieve precise adjustment of back pressure and discharge excess phase change steam, reduce gas content, and further reduce back pressure.

[0007] A plunger pump 9 is used to improve the stable pressure supply. For high-pressure working conditions and steady-state discharge tests, stable and continuous pressurization is carried out. An air compressor 8 is installed on the high-pressure water tank 4. After the high-pressure water tank 4 reaches the predetermined water level 6, compressed gas is injected to reach the target pressure of the test working condition. During the test, the expansion of the gas space provides pressure stabilization performance for the pressure inside the high-pressure water tank 4. For transient two-phase flow discharge test, the high-pressure water tank 4 is pressurized to the predetermined working condition pressure, pressurization is stopped, and the quick-opening valve 11 is opened to carry out the test.

[0008] In the preferred embodiment, to reduce pressure drop and shorten pipeline length, the visualized back pressure container 14 is divided into two parts connected by a connecting flange 21, ensuring safety and reliability during the experiment. Furthermore, the test nozzle is installed using a threaded knob 20, allowing the connecting flange 21 to be opened and different types of test nozzles to be replaced according to the test requirements.

[0009] In the preferred scheme, the test method controlled by the quick-opening valve (11) is adopted to shorten the time error and ensure the accuracy of the transient discharge data.

[0010] In a more preferred embodiment, steady-state back pressure control is achieved using three valves: two back pressure valves 16 at the lower end of the visualized back pressure container 14 and an exhaust valve 15 at the upper end of the container. The exhaust valve 15 can precisely regulate the outlet pressure and discharge excess phase change steam, reducing the gas content and further reducing the back pressure. The two back pressure valves 16 responsible for drainage can adjust the pressure inside the container over a wide range, increasing the margin for back pressure regulation.

[0011] The advantages of this invention are: First, it can capture the jet morphology under backpressure conditions during rupture accidents, filling a research gap in two-phase jet testing. Second, this invention employs a visualized backpressure container that encloses the test nozzle and other components, providing both protection and a backpressure environment. The test nozzle connection uses a threaded knob for installation, allowing for the replacement of different types of test nozzles according to experimental requirements. Finally, it utilizes a three-valve steady-state backpressure control method: two backpressure valves at the lower end of the backpressure container and an exhaust valve at the upper end. The exhaust valve allows for precise outlet adjustment and discharges excess phase-change vapor, reducing the gas content and further lowering the backpressure. The two backpressure valves allow for a wide range of pressure adjustments within the container, increasing the margin for backpressure regulation and pressure stability. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall circuit of the present invention;

[0013] Figure 2 A schematic diagram of the back pressure vessel for visualization;

[0014] The components in the attached diagram are labeled as follows: 1-Level gauge, 2-Temperature sensor, 3-Pressure sensor, 4-High-pressure water tank, 5-Heating rod, 6-Water tank level, 7-Safety valve, 8-Air compressor, 9-Plunger pump, 10-Water storage tank, 11-Quick-opening valve, 12-Flow meter, 13-Test nozzle, 14-Visual back pressure container, 15-Exhaust valve, 16-Back pressure valve, 17-Collection device, 18-Computer host, 19-High-speed camera, 20-Threaded knob, 21-Connecting flange. Detailed Implementation

[0015] like Figure 1 As shown, a two-phase jet morphology capture device under a back pressure rupture accident includes a level gauge 1, a temperature sensor 2, a pressure sensor 3, a high-pressure water tank 4, a heating rod 5, a water tank level indicator 6, a safety valve 7, an air compressor 8, a plunger pump 9, a water storage tank 10, a quick-opening valve 11, a flow meter 12, a test nozzle 13, a visual back pressure container 14, an exhaust valve 15, a back pressure valve 16, a collection device 17, a computer host 18, a high-speed camera 19, a threaded knob 20, and a connecting flange 21.

[0016] The specific implementation process of the two-phase jet morphology capture device under back pressure failure of the present invention is as follows:

[0017] After the entire device is installed, first, the back pressure valve 16 is closed and the exhaust valve 15 is open. The water from the water storage tank 10 is drawn into the high-pressure water tank 4 by the plunger pump 9, and the pressure is increased to 1MPa so that the water level 6 in the tank reaches the set position. The gas in the visual back pressure container 13 is discharged using room temperature water. After the gas is discharged, the exhaust valve 15 is closed and the back pressure valve 16 is opened. At this time, the plunger pump 9 is adjusted to slowly and steadily increase the pressure so that the pressure sensor 3 reaches the set inlet working pressure. At the same time, the opening of the back pressure valve 16 is adjusted so that the back pressure is stabilized to the set value. At this time, the test can be officially started. During the test, the safety valve 7 in front of the test nozzle 6 is opened, and the quick-opening valve 11 is opened at the same time. The high-temperature and high-pressure water is then sprayed out from the high-pressure water tank 4 in the form of a jet. After entering the visualization back pressure container 14, the high-speed camera placed on the side can clearly record the jet pattern during the spraying process and transmit it to the computer host 18. Since the high-temperature and high-pressure water enters the low back pressure area from the high inlet pressure, if the temperature at this time is higher than the saturation temperature under its back pressure, a phase change will occur in the test nozzle 13. At the same time, the pressure in the visualization back pressure container 14 will oscillate during this process. It is necessary to coordinate the adjustment of the opening of the exhaust valve 15 and the back pressure valve 16 so that the back pressure stays at a stable value.

Claims

1. A two-phase jet morphology capture device under a back pressure rupture accident, comprising a high-pressure water tank (4), a heating rod (5), a plunger pump (9), a quick-opening valve (11), a test nozzle (13), a visualization back pressure container (14), an exhaust valve (15), a back pressure valve (16), and a high-speed camera (19). The high-pressure water tank (4) is connected to a water storage tank (10) via the plunger pump (9). Water from the water storage tank (10) is injected into the high-pressure water tank (4) via the plunger pump (9) to pressurize the high-pressure water tank (4). The water in the high-pressure water tank (4) is heated by the heating rod (5) built into the high-pressure water tank. The test nozzle (13) is connected to the high-pressure water tank (4) via the quick-opening valve (11). The test nozzle (13) is located in the visualization back pressure container (14). Inside, a high-pressure water jet is sprayed through the test nozzle (13) in the form of a quick-opening valve (11) to simulate a burst jet. A visual back pressure container (14) is used, and the burst jet inside the visual back pressure container is captured by a high-speed camera (19). The data is transmitted to a computer host (18) connected to the high-speed camera (19). Two back pressure valves (16) are set at the lower end of the visual back pressure container. The back pressure inside the visual back pressure container is adjusted by adjusting the opening of the back pressure valves (16). At the same time, the dual-pipeline drainage design makes the back pressure adjustment range large, which meets the test requirements of high back pressure. An exhaust valve (15) is set at the top of the visual back pressure container to achieve precise adjustment of back pressure and discharge excess phase change steam, reduce gas content, and further reduce back pressure. A plunger pump (9) is used to improve the stable pressure supply. For high-pressure working conditions and steady-state discharge tests, stable and continuous pressurization is carried out. An air compressor (8) is installed on the high-pressure water tank (4). After the high-pressure water tank (4) reaches the predetermined water tank level (6), compressed gas is injected to reach the target pressure of the test working conditions. During the test, the expansion of the gas space provides pressure stabilization performance for the pressure inside the high-pressure water tank (4). A transient two-phase flow discharge test is carried out. The high-pressure water tank (4) is pressurized to the predetermined working condition pressure, pressurization is stopped, and the quick-opening valve (11) is opened to carry out the test.

2. The two-phase jet morphology capture device under a back-pressure rupture accident according to claim 1, characterized in that, In order to reduce pressure drop and shorten pipeline length, the visual back pressure container (14) is divided into two parts connected by a connecting flange (21), which ensures the convenience of the experimental process. The test nozzle connection section is installed with a threaded knob (20), which can open the connecting flange (21) to replace different types of test nozzles according to the test requirements.

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