Break-syphon experiment system and control method of reactor primary loop

Abstract

The application discloses a reactor primary loop anti-siphon experiment system and a control method, and belongs to the field of nuclear power engineering. The system comprises a primary loop main pipeline, an anti-siphon pipeline, a visual pipeline, upper and lower water tanks, a data acquisition system and a control system. The anti-siphon control method is as follows: the siphon state is judged by monitoring the flow meter and liquid level meter signals, and the anti-siphon operation is executed by the control system; a siphon logic identification function is constructed to make a preliminary judgment, and a dynamic residual function is introduced synchronously to make a secondary physical check. When the upper water tank liquid level is lower than the preset threshold value, the outlet flow deviates from the normal flow and remains in the abnormal high flow interval, and the dynamic residual is lower than the allowable error threshold value to effectively filter out the false liquid surface oscillation, the control system determines that the siphon state actually occurs, outputs the opening instruction to the anti-siphon valve, and introduces air into the primary loop main pipeline to block the siphon, so that the real-time monitoring and automatic blocking of the siphon phenomenon are realized. The application improves the precision and anti-interference robustness of the anti-siphon response, effectively prevents the reactor coolant loss accident, and guarantees the safety of the reactor system.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant safety system experimental technology, specifically to a reactor primary loop siphon breaking experimental system and control method. Background Technology

[0002] In nuclear reactor safety design, siphon failure devices, such as active failure valves or passive failure orifices, are crucial for preventing primary coolant loss and protecting core cooling. The timeliness and accuracy of their control system's actions directly impact the absolute safety of the reactor core. Currently, the industry and existing model experimental platforms generally employ single-threshold triggering mechanisms based on a single variable for the automatic control logic of siphon failure devices. However, in real reactor transient conditions and large-diameter fluid systems, boundary conditions are extremely complex. In the early stages of an accident, strong flow disturbances occur, and these hydrodynamic shocks cause severe pseudo-oscillations in the high-level pool liquid level. Traditional single-variable control methods reveal significant technical shortcomings when facing such high-frequency disturbances. Summary of the Invention

[0003] To address the problems of poor anti-interference capability in existing systems, this invention provides a reactor primary loop siphon breaking experimental system and control method. This invention employs a dual-parameter correlation judgment logic of flow rate and liquid level, combined with a dual verification mechanism of logic and physics, which improves the accuracy and anti-interference robustness of the siphon breaking response, effectively preventing accidents involving large-scale loss of reactor coolant and ensuring the safety of the reactor system.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A reactor primary loop siphon breaking experimental system includes a lower water tank 1 and an upper water tank 2, with the upper water tank 2 simulating a reactor pool. One end of the upper water tank 2 is connected to a first throttling orifice plate 13 located in the upper water tank 2, and the other end is connected to the primary loop main pipe 25 of the lower water tank 1. A horizontal visualization pipe 17 is installed on the horizontal section at the highest point of the inverted U-shaped primary loop main pipe 25, and a vertical visualization pipe 18 connected to the horizontal visualization pipe 17 is installed on the vertical section of the primary loop main pipe 25. The horizontal visualization pipe 17 and the vertical visualization pipe 18 are used to observe the two-phase flow regime. One end of the siphon breaking pipe 26 is connected to the horizontal visual pipe 17, and the other end is connected to the third throttling orifice plate 15 in the upper water tank 2; an active siphon breaking valve 19 is arranged on the siphon breaking pipe 26; one end of the main pipe branch 29 is connected to the horizontal visual pipe 17, and the other end is connected to the second throttling orifice plate 14 set in the upper water tank 2; a passive siphon breaking hole 6 located in the upper water tank 2 is arranged on the main pipe branch 29; it also includes a water supply pipe 27 arranged between the lower water tank 1 and the upper water tank 2, a water supply pump 3 and a second flow regulating valve 5 arranged on the water supply pipe 27, and a first flow regulating valve 4 arranged at both ends of the water supply pump 3 to control the flow rate of the water supply pump 3; it also includes two drainage pipes 28 arranged between the lower water tank 1 and the upper water tank 2, and a first ball valve 8 and a second ball valve 9 are respectively installed on them to drain the water in the upper water tank 2; It also includes a pull-down gate 20 arranged in the upper water tank 2, which is used to precisely adjust the overflow boundary and set the initial liquid level of the experiment; It also includes a first electromagnetic flowmeter 10 and an ultrasonic flowmeter 12 arranged on the primary loop main pipe 25 for monitoring the flow in the main pipe; a second electromagnetic flowmeter 11 arranged on the water supply pipe 27 for monitoring the flow in the water supply pipe; a level gauge 21 arranged in the upper water tank 2; a third flow regulating valve 7 arranged at the outlet end of the primary loop main pipe 25; and in order to capture the transient siphon breaking process, it also includes a high-speed camera A22 and a high-speed camera B23 arranged on the side of the top section of the horizontal visualization pipe 17 and the vertical visualization pipe 18, as well as a computer 24 connected to the two cameras for data and image processing. It also includes a control system, which acquires the liquid level signal of the upper water tank 2 in real time through the level gauge 21 at a preset sampling period. The real-time flow signal of the primary main pipeline 25 is obtained through the first electromagnetic flowmeter 10. And the water supply flow rate of the water supply pipe 27 measured by the second electromagnetic flowmeter 11. And adopts siphon logic identification function To determine the siphon state, a dynamic residual function is used. To filter out false liquid level oscillations and determine the true siphon state; after the control system determines that the siphon state has occurred, it outputs an opening command to the active siphon breaking valve 19, introduces air into the primary circuit main pipeline to block the siphon, and realizes real-time monitoring and automatic blocking of the siphon phenomenon.

[0005] The first throttling orifice plate 13, the second throttling orifice plate 14, and the third throttling orifice plate 15 located in the upper water tank 2 are used to simulate the core resistance, the resistance of the main pipeline branch 29, and the resistance of the siphon-breaking pipeline 26, respectively. The experimental system also includes a fourth throttling orifice plate 16 arranged on the primary loop main pipeline 25, between the vertically visualized pipeline 18 and the third flow regulating valve 7. The fourth throttling orifice plate 16 can be replaced with orifice plates of different center diameters to simulate the resistance of the primary loop main pipeline 25 and to study the influence of different resistances of the primary loop main pipeline 25 on the siphon-breaking performance.

[0006] The control system uses dual verification logic to determine the siphon state in real time.

[0007] The control system identifies the function through siphon logic. The specific process for determining the siphon state is as follows: The control system uses a unit step function. Constructing a siphon logic identification function The unit step function performs real-time determination of the pipeline status. The specific logic is that when the independent variable... hour, When the independent variable hour, The siphon logic identification function is: ,in, For the preset liquid level threshold, This is the liquid level signal for the upper water tank 2. This is a function for determining the liquid level height in the upper water tank. This is the flow signal for the primary main pipeline. To preset an abnormally high traffic threshold, Let be the function for determining the flow rate of the primary loop main pipe. The preset flow rate change rate tolerance is set to 1 kg / s. 2 , For time, The function for determining the stability of the flow rate in the primary main pipeline; when If the output is 1 continuously during the sampling window, it is determined that a continuous siphon state has occurred in the pipeline.

[0008] The control system constructs a dynamic residual function based on the law of mass conservation. To filter out false level fluctuations and determine the true siphon state, the specific calculation and judgment logic is as follows: The control system calls the preset fixed cross-sectional area of ​​the upper water tank 2.A Calculate the dynamic residual between the theoretical water loss and the actual measured flow rate. The calculation formula is: When real-time export flow Greater than the preset abnormal high flow threshold And within the preset sampling window period, the dynamic residual function When the liquid level consistently falls below the preset system allowable error threshold of 1 kg / s, the control system confirms a genuine drop in liquid level, determines a continuous siphon state in the pipeline, and outputs a trigger signal. If a sudden change occurs and exceeds the error threshold, the control system determines that the current liquid level change is a false liquid level oscillation caused by hydrodynamic impact and does not output a trigger signal.

[0009] The control method for a reactor primary loop siphon breaking experimental system includes the following steps: Step 1: During normal operation of the experimental system, the liquid level height signal of the upper water tank 2 is acquired in real time through the liquid level gauge 21 at a preset sampling period. The real-time flow signal of the primary main pipeline 25 is obtained through the first electromagnetic flowmeter 10. And the water supply flow rate of the water supply pipe 27 measured by the second electromagnetic flowmeter 11. ; Step 2: The control system uses the real-time liquid level and flow rate signals acquired to identify the siphon logic function. and dynamic residual function The pipeline status is assessed in real time to confirm whether a continuous siphoning condition has occurred; Step 3: After determining that a siphon state has occurred, the control system immediately outputs a trigger signal to drive the active siphon breaking valve 19 to open, injecting air into the primary main pipeline 25 to break the negative pressure inside the pipeline and block the siphon effect. If the active siphon breaking valve 19 cannot block the siphon, as the water level drops until the passive siphon breaking hole 6 is exposed above the water surface, air enters the primary main pipeline 25 along the main pipeline branch 29, blocking the siphon. Step 4: After the active siphon breaker valve 19 is opened, the control system continuously monitors the real-time flow signal. ;like If the flow rate falls below the predetermined threshold within the scheduled time, and When the water level approaches zero, the system is determined to have returned to a safe water level, and then the control system outputs a command to close the siphon failure valve.

[0010] Advantages of this invention: (1) The system is equipped with horizontal and vertical visualization pipes, and with the help of dual high-speed cameras, it can simultaneously capture transient phenomena such as instability, breakage and liquid level fluctuation of the gas-liquid interface during the siphon failure process. This provides high-precision and multi-dimensional image evidence for verifying numerical simulation.

[0011] (2) The system is designed with replaceable throttling orifice plates, which can simulate the effect of different pipe resistances on the siphon breaking performance, thereby studying the effect of pipe resistance on the siphon breaking rate of the siphon breaking device, and thus guiding the optimization of pipeline layout in engineering.

[0012] (3) The control system utilizes a siphon logic identification function constructed from liquid level and flow rate to determine the siphon state, thus overcoming the shortcomings of traditional single liquid level monitoring which is easily disturbed by water flow fluctuations. In actual operation, even if the water surface experiences severe false fluctuations due to disturbances, the system can eliminate interference through a dynamic residual function and accurately identify the true siphon phenomenon. This design significantly reduces the probability of false triggering of the siphon failure device and significantly improves the reliability of the reactor safety system. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the siphon breaking experimental system for the primary loop of the reactor of the present invention. The components in the attached diagram are labeled as follows: 1. Lower water tank; 2. Upper water tank; 3. Feedwater pump; 4. First flow regulating valve; 5. Second flow regulating valve; 6. Passive siphon breaking orifice; 7. Third flow regulating valve; 8. First ball valve; 9. Second ball valve; 10. First electromagnetic flowmeter; 11. Second electromagnetic flowmeter; 12. Ultrasonic flowmeter; 13. First orifice plate; 14. Second orifice plate; 15. Third orifice plate; 16. Fourth orifice plate; 17. Horizontal visual pipe; 18. Vertical visual pipe; 19. Active siphon breaking valve; 20. Pull-down gate; 21. Level gauge; 22. High-speed camera A; 23. High-speed camera B; 24. Computer; 25. Primary loop main pipe; 26. Siphon breaking pipe; 27. Feedwater pipe; 28. Drainage pipe; 29. ​​Main pipe branch. Detailed Implementation

[0014] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0015] like Figure 1As shown, the present invention discloses a reactor primary loop siphon breaking experimental system, comprising a lower water tank 1 and an upper water tank 2, the upper water tank 2 simulating a reactor pool; one end is connected to a first throttling orifice plate 13 located in the upper water tank 2, and the other end is connected to the primary loop main pipe 25 of the lower water tank 1; a horizontal visualization pipe 17 is set on the horizontal section at the highest point of the inverted U-shape of the primary loop main pipe 25, and a vertical visualization pipe 18 connected to the horizontal visualization pipe 17 is set on the vertical section of the primary loop main pipe 25; the horizontal visualization pipe 17 and the vertical visualization pipe 18 are used to observe the two-phase flow state. One end of the siphon breaking pipe 26 is connected to the horizontal visible pipe 17, and the other end is connected to the third throttling orifice plate 15 in the upper water tank 2; an active siphon breaking valve 19 is arranged on the siphon breaking pipe 26; one end of the main pipe branch 29 is connected to the horizontal visible pipe 17, and the other end is connected to the second throttling orifice plate 14 set in the upper water tank 2; a passive siphon breaking orifice 6 located in the upper water tank 2 is arranged on the main pipe branch 29; it also includes a water supply pipe 27 arranged between the lower water tank 1 and the upper water tank 2, a water supply pump 3 and a second flow regulating valve 5 arranged on the water supply pipe 27, and a bypass arrangement. The first flow regulating valve 4 at both ends of the water pump 3 is used to control the flow rate of the water pump 3 and thus precisely control the water flow rate entering the upper water tank 2; it also includes two drainage pipes 28 arranged between the lower water tank 1 and the upper water tank 2, and a first ball valve 8 and a second ball valve 9 are respectively installed on them to realize the rapid emptying of water in the upper water tank 2; the siphon breaking device includes two modes: one is an active siphon breaking valve 19 installed on the siphon breaking pipe 26; the other is a passive siphon breaking hole 6 set on the main pipe branch 29 and located between the second throttling orifice plate 14 and the horizontal visual pipe 17.

[0016] It also includes a pull-down gate 20 arranged in the upper water tank 2, which is used to precisely adjust the overflow boundary and set the initial liquid level for the experiment.

[0017] It also includes a first electromagnetic flowmeter 10 and an ultrasonic flowmeter 12 arranged on the primary loop main pipe 25 for monitoring the flow in the main pipe; a second electromagnetic flowmeter 11 arranged on the water supply pipe 27 for monitoring the flow in the water supply pipe; a level gauge 21 arranged in the upper water tank 2; a third flow regulating valve 7 arranged at the outlet end of the primary loop main pipe 25; and, in order to capture the transient siphon breaking process, high-speed cameras A22 and B23 are arranged on the sides of the top sections of the horizontal visualization pipe 17 and the vertical visualization pipe 18, as well as a computer 24 connected to the two cameras for data and image processing.

[0018] It also includes a control system, which acquires the liquid level signal of the upper water tank 2 in real time through the level gauge 21 at a preset sampling period. The real-time flow signal of the primary main pipeline 25 is obtained through the first electromagnetic flowmeter 10. And the water supply flow rate of the water supply pipe 27 measured by the second electromagnetic flowmeter 11. And adopts siphon logic identification function To determine the siphon state, a dynamic residual function is used. To filter out false liquid level oscillations and determine the true siphon state; after the control system determines that the siphon state has occurred, it outputs an opening command to the active siphon breaking valve 19, introduces air into the primary circuit main pipeline to block the siphon, and realizes real-time monitoring and automatic blocking of the siphon phenomenon.

[0019] The first throttling orifice plate 13, the second throttling orifice plate 14, and the third throttling orifice plate 15 located in the upper water tank 2 are used to simulate the core resistance, the resistance of the main pipeline branch 29, and the resistance of the siphon-breaking pipeline 26, respectively. The experimental system also includes a fourth throttling orifice plate 16 arranged on the primary loop main pipeline 25, between the vertically visualized pipeline 18 and the third flow regulating valve 7. The fourth throttling orifice plate 16 can be replaced with orifice plates of different center diameters to simulate the resistance of the primary loop main pipeline 25 and to study the influence of different resistances of the primary loop main pipeline 25 on the siphon-breaking performance.

[0020] The control system employs dual-verification logic to determine the siphon state in real time. First, the control system identifies the siphon state through the siphon logic identification function. The specific process for determining the siphon state is as follows: The control system uses a unit step function. Constructing a siphon logic identification function The unit step function performs real-time determination of the pipeline status. The specific logic is that when the independent variable... hour, When the independent variable hour, The siphon logic identification function is: ,in, For the preset liquid level threshold, This is the liquid level signal for the upper water tank. This is the function for determining the liquid level height of the upper water tank 2. This is the flow signal for the primary main pipeline. To preset an abnormally high traffic threshold, Let be the function for determining the flow rate of the primary loop main pipe. The preset flow rate change rate tolerance is set to 1 kg / s. 2 , For time, The function for determining the stability of the flow rate in the primary main pipeline; when If the output is 1 continuously during the sampling window, it is determined that a continuous siphon state has occurred in the pipeline.

[0021] To eliminate false fluctuations in the level gauge signal caused by pump and water flow fluctuations, the control system constructs a dynamic residual function based on the law of mass conservation. To filter out false level fluctuations and determine the true siphon state, the specific calculation and judgment logic is as follows: The control system calls the preset fixed cross-sectional area of ​​the upper water tank 2. A Calculate the dynamic residual between the theoretical water loss and the actual measured flow rate. The calculation formula is: When real-time export flow Greater than the preset abnormal high flow threshold And within the preset sampling window period, the dynamic residual function When the liquid level consistently falls below the preset system allowable error threshold of 1 kg / s, the control system confirms a genuine drop in liquid level, determines a continuous siphon state in the pipeline, and outputs a trigger signal. If a sudden change occurs and exceeds the error threshold, the control system determines that the current liquid level change is a false liquid level oscillation caused by hydrodynamic impact and does not output a trigger signal.

[0022] The control method of the reactor primary loop siphon breaking experimental system described in this invention is as follows: Step 1: Before starting the experiment, check the connection status of the system pipelines and instruments. Adjust the first orifice plate 13, the second orifice plate 14, the third orifice plate 15, and the fourth orifice plate 16 to meet the operating requirements; first, supply water to the lower water tank 1 through the external water pipe, open the first flow regulating valve 4 and the second flow regulating valve 5, turn on the water pump 3 to supply water to the upper water tank 2 until the water level reaches a certain level, and open the third flow regulating valve 7 to fill the primary loop main pipeline 25 with water.

[0023] Step 2: During normal operation of the experimental system, the liquid level height signal of the upper water tank 2 is acquired in real time through the liquid level gauge 21 at a preset sampling period. The real-time flow signal of the primary main pipeline 25 is obtained through the first electromagnetic flowmeter 10. And the water supply flow rate of the water supply pipe 27 measured by the second electromagnetic flowmeter 11. .

[0024] Step 3: The control system identifies the function through siphon logic. and dynamic residual function To determine whether a siphon failure has occurred; Step 4: Upon determining that a siphon state has occurred, the control system immediately outputs a trigger signal to drive the active siphon breaking valve 19 to open, injecting air into the primary main pipe 25 to disrupt the negative pressure inside the pipe and block the siphon. If the active siphon breaking valve 19 fails to block the siphon, as the water level drops until the passive siphon breaking hole 6 emerges above the water surface, air enters the primary main pipe 25 along the branch pipe 29, blocking the siphon. Simultaneously, high-speed cameras A22 and B23 record the evolution of the gas-liquid two-phase interface in the horizontal visualization pipe 17 and the vertical visualization pipe 18. The first electromagnetic flowmeter 10, the second electromagnetic flowmeter 11, and the level gauge 21 record the fluid loss characteristics in real time, completing a full siphon breaking performance test.

[0025] Step 5: After the active siphon breaker valve 19 is opened, the control system continuously monitors the real-time flow signal. ;like If the flow rate falls below the predetermined threshold within the scheduled time, and Once the water level approaches zero, the system is considered to have returned to a safe water level. After confirming the siphon breaking process is complete and transient data acquisition is finished, all recording equipment and power sources are stopped. The fluid in the upper water tank 2 is drained into the lower water tank 1, restoring the system to its initial state, ready for the next set of operating condition experiments.

Claims

1. A reactor primary loop siphon breaking experimental system, characterized in that: The system includes a lower water tank (1) and an upper water tank (2), with the upper water tank (2) simulating a reactor pool. One end of the upper water tank (2) is connected to the first orifice plate (13) in the upper water tank (2), and the other end is connected to the primary loop main pipe (25) of the lower water tank (1). A horizontal visualization pipe (17) is installed on the horizontal section of the highest point of the inverted U-shaped primary loop main pipe (25), and a vertical visualization pipe (18) connected to the horizontal visualization pipe (17) is installed on the vertical section of the primary loop main pipe (25). One end of the siphon destruction pipe (26) is connected to the horizontal visualization pipe (17), and the other end is connected to the third orifice plate (15) in the upper water tank (2). An active siphon destruction valve (19) is arranged on the siphon destruction pipe (26). One end of the main pipe branch (29) is connected to the horizontal... The visible pipe (17) is connected to the other end, and the second throttling orifice plate (14) is set in the upper water tank (2); a passive siphon breaking hole (6) is arranged in the upper water tank (2) on the main pipe branch (29); it also includes a water supply pipe (27) arranged between the lower water tank (1) and the upper water tank (2), a water supply pump (3) and a second flow regulating valve (5) arranged on the water supply pipe (27), and a first flow regulating valve (4) arranged at both ends of the water supply pump (3) to control the flow rate of the water supply pump (3); it also includes two drainage pipes (28) arranged between the lower water tank (1) and the upper water tank (2), and a first ball valve (8) and a second ball valve (9) are respectively set on them to drain the water in the upper water tank (2); It also includes a pull-down gate (20) arranged in the upper water tank (2) for precisely adjusting the overflow boundary and setting the initial liquid level of the experiment; It also includes a first electromagnetic flowmeter (10) and an ultrasonic flowmeter (12) arranged on the primary main pipeline (25) for monitoring the flow in the main pipeline; a second electromagnetic flowmeter (11) arranged on the water supply pipeline (27) for monitoring the flow in the water supply pipeline; a level gauge (21) arranged in the upper water tank (2); a third flow regulating valve (7) arranged at the outlet end of the primary main pipeline (25); a high-speed camera A (22) and a high-speed camera B (23) arranged on the sides of the top sections of the horizontal visualization pipeline (17) and the vertical visualization pipeline (18); and a computer (24) connecting the two cameras. It also includes a control system, which acquires the liquid level signal of the upper water tank (2) in real time through a level gauge (21) at a preset sampling period. The real-time flow signal of the primary main pipeline (25) is obtained through the first electromagnetic flowmeter (10). And the water supply flow rate of the water supply pipe (27) measured by the second electromagnetic flow meter (11). And adopts siphon logic identification function To determine the siphon state, a dynamic residual function is used. To filter out false liquid level oscillations and determine the true siphon state; after the control system determines that the siphon state has occurred, it outputs an opening command to the active siphon breaking valve (19) and introduces air into the primary loop main pipeline to block the siphon, thereby realizing real-time monitoring and automatic blocking of the siphon phenomenon.

2. The reactor primary loop siphon breaking experimental system according to claim 1, characterized in that: The first throttling orifice plate (13), the second throttling orifice plate (14), and the third throttling orifice plate (15) located in the upper water tank (2) are used to simulate the core resistance, the main pipeline branch (29) resistance, and the siphon-breaking pipeline (26) resistance, respectively. The experimental system also includes a fourth throttling orifice plate (16) arranged on the primary loop main pipeline (25) between the vertical visualization pipeline (18) and the third flow regulating valve (7). The fourth throttling orifice plate (16) can be replaced with orifice plates with different center diameters to simulate the resistance of the primary loop main pipeline (25) and study the influence of different primary loop main pipeline (25) resistances on the siphon-breaking performance.

3. The reactor primary loop siphon breaking experimental system according to claim 1, characterized in that, The control system identifies the function through siphon logic. The specific process for determining the siphon state is as follows: The control system uses a unit step function. Constructing a siphon logic identification function The unit step function performs real-time determination of the pipeline status. The specific logic is that when the independent variable... hour, When the independent variable hour, The siphon logic identification function is: ,in, For the preset liquid level threshold, This is the liquid level signal for the upper water tank 2. This is a function for determining the liquid level height in the upper water tank. This is the flow signal for the primary main pipeline. To preset an abnormally high traffic threshold, Let be the function for determining the flow rate of the primary loop main pipe. The preset flow rate change rate tolerance is set to 1 kg / s. 2 , For time, The function for determining the stability of the flow rate in the primary main pipeline; when If the output is 1 continuously during the sampling window, it is determined that a continuous siphon state has occurred in the pipeline.

4. The reactor primary loop siphon breaking experimental system according to claim 1, characterized in that, The control system constructs a dynamic residual function based on the law of mass conservation. To filter out false level fluctuations and determine the true siphon state, the specific calculation and judgment logic is as follows: The control system calls the preset fixed cross-sectional area of ​​the upper water tank (2). A Calculate the dynamic residual between the theoretical water loss and the actual measured flow rate. The calculation formula is: When real-time export flow Greater than the preset abnormal high flow threshold And within the preset sampling window period, the dynamic residual function When the liquid level consistently falls below the preset system allowable error threshold of 1 kg / s, the control system confirms a genuine drop in liquid level, determines a continuous siphon state in the pipeline, and outputs a trigger signal. If a sudden change occurs and exceeds the error threshold, the control system determines that the current liquid level change is a false liquid level oscillation caused by hydrodynamic impact and does not output a trigger signal.

5. A control method for a reactor primary loop siphon breaking experimental system according to any one of claims 1 to 4, characterized in that: The method, when applied to the above experimental system, includes the following steps: Step 1: When the experimental system is running normally, the liquid level signal of the upper water tank (2) is acquired in real time through the level gauge (21) at a preset sampling period. The real-time flow signal of the primary main pipeline (25) is obtained through the first electromagnetic flowmeter (10). And the water supply flow rate of the water supply pipe (27) measured by the second electromagnetic flow meter (11). ; Step 2: The control system uses the real-time liquid level and flow rate signals acquired to identify the siphon logic function. and dynamic residual function The pipeline status is assessed in real time to confirm whether a continuous siphoning condition has occurred; Step 3: After determining that the siphon state has occurred, the control system immediately outputs a trigger signal to drive the active siphon breaking valve (19) to open and inject air into the primary main pipeline (25) to break the negative pressure inside the pipeline and block the siphon effect. If the active siphon breaking valve (19) cannot block the siphon, as the water level drops to the point where the passive siphon breaking hole (6) is exposed on the water surface, air enters the primary main pipeline (25) along the branch of the main pipeline (29) and blocks the siphon. Step 4: After the active siphon breaker valve (19) is opened, the control system continuously monitors the real-time flow signal. ;like If the flow rate falls below the predetermined threshold within the scheduled time, and When the water level approaches zero, the system is determined to have returned to a safe water level, and then the control system outputs a command to close the siphon failure valve.

Images