Two-phase jet flow form capturing device with back pressure under break accident

Abstract

The invention discloses a two-phase jet flow form capturing device with back pressure under a break accident, which comprises a high-pressure water tank, a heating rod, a plunger pump, a quick-opening valve, a test nozzle, a visual back pressure container, an exhaust valve, a back pressure valve, a high-speed camera and the like. A medium in the high-pressure water tank is heated through a built-in heating rod, and a quick-opening valve is selected for spraying; a visual backpressure container is adopted, a high-speed camera is used for carrying out form capture on crevasse jet flow in the container and transmitting data to a computer host, a test nozzle is located in the visual backpressure container, two backpressure valves are arranged at the lower end of the container, and the internal backpressure of the container is adjusted through the opening degrees of the valves, so that the test requirement of high backpressure is met; the exhaust valve is arranged at the top end of the container, the back pressure is accurately adjusted, phase-change steam can be exhausted, the gas content is reduced, and the back pressure is further reduced.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear reactor large breach accident jet impact test, in particular to a two-phase jet morphology capture device under a breach accident with back pressure. Background Art

[0002] During the operation of the reactor, high-temperature and high-pressure water is ejected through holes or cracks of different sizes. Due to the high speed of water under high pressure and the occurrence of phase change, it will have a great impact on objects and even cut them, which seriously threatens the safety of nuclear power plant operation. Therefore, studying the morphological changes of the jet under high temperature and high pressure is of great significance to the safety of the reactor.

[0003] At present, scholars at home and abroad have conducted extensive and in-depth research on high-pressure single-phase water or gas jets in theoretical models, etc., but most of the research remains in the environment of normal pressure, lacking the study of jet morphology under different back pressure environments. In addition, due to the complexity and difficulty of high-pressure and high-temperature medium experiments, few people have studied and explored the research on liquid jet technology under high parameters. Therefore, it is necessary to further explore the morphology of high-temperature and high-pressure jets on the basis of predecessors. On this basis, a two-phase leakage jet morphology change capture device under back pressure conditions is designed to make up for the lack of high-temperature and high-pressure jet morphology and flow data under different back pressure conditions of nuclear reactors. Summary of the invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a two-phase jet morphology capture device under a breach accident with back pressure, which can capture the jet morphology under high back pressure environment in a breach accident, filling the research gap in two-phase jet experiments.

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

[0006] A two-phase jet morphology capturing device under a breach accident with back pressure, 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 visualized 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 in the water storage tank 10 is injected into the high-pressure water tank 4 via the plunger pump 9 to increase the pressure of the high-pressure water tank 4. The water in the high-pressure water tank 4 is heated via the built-in heating rod 5 of 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 visualized back-pressure container 14. The quick-opening valve 11 is selected to pass through the high-pressure water tank 4. High-pressure water is sprayed through the test nozzle 13 to simulate the rupture jet; a visual back pressure container 14 is used, and the rupture jet in the visual back pressure container is captured by a high-speed camera 19, and the data is transmitted to a computer host 18 connected to the high-speed camera 19, and two back pressure valves 16 are set at the lower end of the visual back pressure container, and the back pressure inside the visual back pressure container is adjusted by the opening of the back pressure valve 16. At the same time, the double-pipeline drainage design makes the back pressure adjustment range large, meeting the test requirements of high back pressure, and an exhaust valve 15 is set at the top of the visual back pressure container to achieve the effect of accurately adjusting the back pressure, and discharge the excess phase change steam, reduce the gas content, and further reduce the back pressure;

[0007] A plunger pump 9 is used to improve the stable pressure supply. For high-pressure working conditions and steady-state spraying tests, stable and continuous pressurization is performed, and 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 liquid 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 in the high-pressure water tank 4. A transient two-phase flow spraying test is performed, and the high-pressure water tank 4 is pressurized to the predetermined working condition pressure, the pressurization is stopped, and the quick-opening valve 11 is opened for testing.

[0008] In the preferred solution, in order to reduce the pressure drop and reduce the length of the pipeline, the visual back pressure container 14 is divided into two parts connected in the form of a connecting flange 21, which ensures safety and reliability during the experiment, and the test nozzle is installed with a threaded knob 20. The connecting flange 21 can be opened according to the test requirements to replace different types of test nozzles.

[0009] In the preferred solution, a test method controlled by a quick-opening valve (11) is adopted to achieve the purpose of shortening the time error and ensure the accuracy of the transient spraying data.

[0010] In a more preferred solution, a steady-state back pressure control is adopted with three valves, namely, 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 achieve the effect of accurately adjusting the outlet pressure, and discharge excess phase-changed steam, thereby reducing the gas content and further reducing the back pressure; the two back pressure valves 16 responsible for drainage can adjust the pressure in the container over a wide range, thereby increasing the margin for back pressure regulation.

[0011] The advantages of the present invention are: first, the jet morphology in the back pressure environment under the breach accident can be captured, filling the research gap of the two-phase jet test; second, the present invention adopts a visualized back pressure container, which contains the test nozzle and other parts, plays a role in protecting and providing the back pressure environment, and the test nozzle connection section is installed with a threaded knob, and different types of test nozzles can be replaced according to the test requirements. Finally, a steady-state back pressure control method using three valves is adopted, namely, two back pressure valves at the lower end of the back pressure container and an exhaust valve at the upper end. The exhaust valve can achieve the effect of accurately adjusting the outlet, and can discharge excess phase-changed steam, reduce the gas content and further reduce the back pressure. The two back pressure valves can adjust the pressure in the container over a wide range, increasing the margin of back pressure regulation and the stability of pressure. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0013] Figure 2 Schematic diagram of a visual back pressure vessel;

[0014] The components in the accompanying drawings are marked as follows: 1-liquid level meter, 2-temperature sensor, 3-pressure sensor, 4-high-pressure water tank, 5-heating rod, 6-water tank liquid 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-visualized back pressure container, 15-exhaust valve, 16-back pressure valve, 17-collecting device, 18-computer host, 19-high-speed camera, 20-threaded knob, 21-connecting flange. DETAILED DESCRIPTION

[0015] like Figure 1 As shown, a two-phase jet morphology capturing device under a breach accident with back pressure includes a liquid level meter 1, a temperature sensor 2, a pressure sensor 3, a high-pressure water tank 4, a heating rod 5, a water tank liquid level 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 visualized back pressure container 14, an exhaust valve 15, a back pressure valve 16, a collecting 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 the breach accident with back pressure 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 pumped into the high-pressure water tank 4 through the plunger pump 9, and the pressure is increased to 1MPa at the same time, so that the water tank liquid level 6 reaches the set position. The gas in the visual back pressure container 13 is discharged with 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 increase the pressure steadily and slowly, so that the pressure sensor 3 reaches the set inlet operating pressure. At the same time, the valve opening of the back pressure valve 16 is adjusted to stabilize the back pressure 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, and the high-temperature and high-pressure water is sprayed out from the high-pressure water tank 4 in the form of a jet. After entering the visual back pressure container 14, the high-speed camera placed on one side can clearly record the jet shape 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 visual back pressure container 14 will oscillate during this process, and it is necessary to coordinate the opening of the exhaust valve 15 and the back pressure valve 16 to make the back pressure remain at a stable value.

Claims

1. A two-phase jet morphology capturing device under a breach accident with back pressure, 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 visualized back-pressure container (14), an exhaust valve (15), a back-pressure valve (16) and a high-speed camera (19), wherein the high-pressure water tank (4) is connected to a water storage tank (10) via a plunger pump (9), water in the water storage tank (10) is injected into the high-pressure water tank (4) via the plunger pump (9) to increase the pressure of the high-pressure water tank (4), the water in the high-pressure water tank (4) is heated via a built-in heating rod (5) in the high-pressure water tank, the test nozzle (13) is connected to the high-pressure water tank (4) via the quick-opening valve (11), and the test nozzle (13) is located in the visualized back-pressure container (14). Inside, a quick-opening valve (11) is selected to spray high-pressure water through a test nozzle (13) to simulate a rupture jet; a visual back pressure container (14) is used, and the rupture jet in the visual back pressure container is captured by a high-speed camera (19), and the data is transmitted to a computer host (18) connected to the high-speed camera (19); two back pressure valves (16) are arranged at the lower end of the visual back pressure container, and the back pressure inside the visual back pressure container is adjusted by the opening of the back pressure valve (16); at the same time, the double-pipeline drainage design makes the back pressure adjustment range large, meeting the test requirements of high back pressure; an exhaust valve (15) is arranged at the top of the visual back pressure container to achieve the effect of accurately adjusting the back pressure, and discharge excess phase-changed steam, reduce the gas content, and further reduce the back pressure; A plunger pump (9) is used to increase the stable pressure supply. For high-pressure working conditions and steady-state spraying tests, a stable and continuous pressurization is performed. An air compressor (8) is installed on the high-pressure water tank (4). After the high-pressure water tank (4) reaches a predetermined water tank liquid 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 a pressure-stabilizing performance for the pressure in the high-pressure water tank (4). A transient two-phase flow spraying test is performed. The high-pressure water tank (4) is pressurized to the predetermined working condition pressure, the pressurization is stopped, and the quick-opening valve (11) is opened to perform the test.

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

3. The device for capturing two-phase jet flow in a breach accident with back pressure according to claim 1 is characterized in that: The test method controlled by the quick-opening valve (11) is adopted to achieve the purpose of shortening the time error and ensure the accuracy of the transient spraying data.

4. The device for capturing two-phase jet flow in a breach accident with back pressure according to claim 1 is characterized in that: Steady-state back pressure control is achieved by using three valves, namely 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 adjust the outlet pressure and discharge excess steam with phase change, thereby reducing the gas content and further reducing the back pressure. The two back pressure valves (16) responsible for drainage can adjust the pressure in the container over a wide range, thereby increasing the margin for back pressure regulation.

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