A remote leakage monitoring and positioning system for the charging valve box of a fusion device

Abstract

The invention belongs to the operation technology of thermonuclear fusion reactor, and specifically relates to a remote leakage monitoring and positioning system for a charging valve box of a fusion device, comprising a gas supply pipeline and an external containment pipe, wherein the containment pipe is provided with a nitrogen outlet pipeline and a plurality of manifolds, each manifold end is provided with a charging valve box, and an inlet is processed on the side wall of the lower end of each charging valve box as a nitrogen injection port; the gas supply pipeline is provided with one more gas supply branch pipe than the number of manifolds, one gas supply branch pipe is located in the nitrogen outlet pipeline, and the other gas supply branch pipes are respectively located in the corresponding manifolds and extend into the corresponding charging valve box; the manifold is provided with a bypass pipeline, which is connected with the nitrogen outlet of the charging valve box and the inside of the manifold, and can remotely monitor and quickly locate the leaking valve box and isolate the valve box.

Description

Technical Field

[0001] The invention belongs to the operation technology of thermonuclear fusion reactor, and in particular relates to a gas supply pipeline leakage monitoring and positioning system. Background Art

[0002] Future thermonuclear fusion reactors will use hydrogen, deuterium, and tritium as fuel, and use edge gas injection, pellet injection and other methods for fuel replenishment. Hydrogen, deuterium, tritium and other fuels are transported from the gas storage and transportation system to the vicinity of the device through the gas supply pipeline, and then injected into the vacuum chamber after type selection, flow control or pellet preparation. Tritium is radioactive, and its leakage may endanger personnel safety, so the gas supply pipeline needs to be monitored for leakage during the operation of the fusion device.

[0003] According to the requirements of tritium safety protection, in addition to the primary containment pipeline that is in direct contact with tritium, the gas supply system also needs to design a secondary containment layer to prevent tritium from leaking directly into the environment. The space between the primary containment pipeline and the secondary containment layer is called the interlayer space, which is generally filled with an inert gas (such as nitrogen) below the ambient pressure. This is a typical feature of tritium-related operating devices. For the gas supply pipeline, the secondary containment layer can be designed as a pipeline with a larger diameter, which surrounds the primary containment tube of tritium, or several primary containment pipelines of fuel gas together to form a composite pipeline; and the gas supply control device located near the device uses a valve box as the secondary containment layer. For future fusion devices, multiple fuel valve boxes are generally configured to achieve multi-point injection, or as a backup valve box. The composite pipeline for gas supply is designed as a manifold structure to supply gas to multiple valve boxes at the same time.

[0004] For the current fusion devices involving tritium, the detection of tritium leakage in the gas supply pipeline is mainly to regularly send the gas in the interlayer space to the analysis room of the tritium plant for tritium concentration analysis, and the timeliness of leak detection is significantly delayed. In addition, if a leak is found, it is impossible to locate the injection point of the leak, and the leak point location can only be checked one by one through on-site leak detection. For future fusion devices, the scale is larger, and the design of the gas supply system and the tritium plant is more complicated. It is no longer feasible to rely on the analysis system of the tritium plant to directly identify the leak of the gas supply system. Since the control devices of the gas supply pipeline are mainly located in the valve box, considering that the probability of leakage of various live connections is much greater than the probability of pipeline welding, it can be inferred that the leakage of the gas supply system is most likely to occur in the valve box, and the charging valve box must be leak-monitored and located during the experimental operation. However, the charging valve box is located near the device, and high-energy neutrons and strong ionizing radiation continue to exist in its surrounding environment. During the experimental operation, personnel are strictly prohibited from entering and leaving. Even after shutdown, personnel can only enter the vicinity of the device for maintenance after the radiation dose in the environment drops to the permitted threshold. This means that for future steady-state fusion devices, it will take a long time before on-site leak detection can be carried out.

[0005] The fueling system is an indispensable system for the operation of the fusion device. How to remotely realize the rapid leakage monitoring, positioning and isolation of the fueling valve box to minimize unnecessary device shutdown events (abandoning the leaking valve box and ensuring the normal operation of the gas supply system) is a problem that must be solved by the future fusion reactor fueling system. Summary of the invention

[0006] The purpose of the present invention is to provide a remote leakage monitoring and positioning system for a fusion device charging valve box, which can remotely monitor and quickly locate the leaking valve box and isolate the valve box.

[0007] The technical solution of the present invention is as follows:

[0008] A remote leakage monitoring and positioning system for a charging valve box of a fusion device comprises an air supply pipeline and an external containment pipe, wherein the containment pipe is provided with a nitrogen outlet pipeline and a plurality of manifolds, each manifold end is provided with a charging valve box, and an inlet is processed on the side wall of the lower end of each charging valve box as a nitrogen injection port; the air supply pipeline is provided with one more air supply branch pipe than the number of manifolds, one air supply branch pipe is located in the nitrogen outlet pipeline, and the other air supply branch pipes are respectively located in the corresponding manifolds and extend into the corresponding charging valve boxes; the manifold is provided with a bypass pipeline, which connects the nitrogen outlet of the charging valve box and the inside of the manifold.

[0009] The gas supply branch pipes in the manifold are a plurality of parallel branches branched from the gas supply pipe, which are N gas delivery pipes and one exhaust pipe.

[0010] The N air supply pipelines are all provided with a pneumatic isolation valve D and a pneumatic isolation valve C, the exhaust pipeline is provided with a pneumatic isolation valve E, and a pressure sensor B is provided on the pipeline at the confluence of all parallel branches.

[0011] The bypass pipeline is provided with a pneumatic isolation valve B for opening or closing the bypass pipeline.

[0012] A pneumatic isolation valve A is provided on the pipeline where the nitrogen injection port is located, which is used to open or close the injection pipeline.

[0013] A pressure sensor A is provided on the gas supply branch pipe located on the nitrogen outlet pipeline.

[0014] When the measured value of pressure sensor A exceeds 0.95bar, all pneumatic isolation valves D are closed, and pneumatic isolation valves C and E are opened until the measured value of pressure sensor B8 drops below 0.01bar, and pneumatic isolation valve E is closed. If the signal of a pressure sensor B8 rises to 0.1bar and continues to rise, it is determined that the corresponding feeding valve box is leaking.

[0015] A gas monitor is provided on the gas supply branch pipe of the nitrogen outlet pipeline.

[0016] When the volume concentration of hydrogen or deuterium detected by the gas monitor exceeds 1% VOL or the radioactivity concentration of tritium detected exceeds 1E8 Bq / m 3 , all pneumatic isolation valves D are closed, pneumatic isolation valves C and E are opened until the measured value of pressure sensor B8 drops below 0.01 bar, and pneumatic isolation valve E is closed. If the signal of a pressure sensor B rises to 0.1 bar and continues to rise, it is determined that the corresponding feeding valve box is leaking.

[0017] The measuring range of the pressure sensor B is 0-1 bar, and the measuring range of the pressure sensor A is 0-2 bar.

[0018] The exhaust pipe is in a vacuum state, and the vacuum degree is 1Pa-100Pa.

[0019] The working pressure range of the gas supply pipeline is 0.85 bar to 0.92 bar.

[0020] The remarkable effects of the present invention are as follows:

[0021] 1. A bypass is used between the feeding valve box and the containment pipe. A nitrogen injection port is set in the valve box, and a nitrogen outlet and a gas monitor are set near the end of the containment pipe. Nitrogen flows continuously to achieve real-time monitoring of gas composition.

[0022] 2. After the gas supply pipeline enters the valve box, a pneumatic isolation valve is installed to connect or disconnect the valve box from the gas supply pipeline. This design allows each valve box to be isolated from the entire gas supply system for leak location, and allows the system to continue to operate after the leaking valve box is isolated;

[0023] 3. The gas supply pipeline is connected or disconnected with the exhaust pipeline in the valve box by a pneumatic isolation valve, which can realize the gas exhaust and replacement of the gas supply pipeline.

[0024] 4. A pressure sensor is installed on the gas supply pipeline, and a pressure sensor is installed on the connecting section between the gas supply pipeline and the exhaust pipeline in the valve box. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the remote leakage monitoring and positioning system for the fusion device fuel valve box;

[0026] Figure 2 This is a schematic diagram of the location structure of the feeding valve box;

[0027] In the figure: 1. Feeding valve box; 2. Nitrogen injection port; 3. Bypass pipe, 4. Containment pipe, 5. Air supply pipe; 6. Gas monitor, 7. Pressure sensor A; 8. Pressure sensor B; 9. Pneumatic isolation valve A; 10. Pneumatic isolation valve B; 11. Pneumatic isolation valve C; 12. Pneumatic isolation valve D; 13. Pneumatic isolation valve E; 14. Air supply pipe; 15. Exhaust pipe. DETAILED DESCRIPTION

[0028] The present invention will be further described below through the accompanying drawings and specific implementation methods.

[0029] like Figure 1 As shown, the fuel gas is transported to a plurality of charging valve boxes 1 through a gas supply pipeline 5 .

[0030] The air supply pipeline 5 is installed in the containment tube 4, which is provided with a nitrogen outlet pipeline and a plurality of manifolds. A feeding valve box 1 is installed at the end of each manifold. An inlet is processed on the lower side wall of each feeding valve box 1 as a nitrogen injection port 2.

[0031] Each gas supply branch of the gas supply pipeline 5 extends into the feeding valve box 1 in the manifold, and a bypass pipeline 3 is installed on each manifold, which connects the nitrogen outlet of the feeding valve box 1 and the inside of the manifold;

[0032] A pressure sensor A7 is installed on the gas supply branch pipe of the gas supply pipe 5 in the nitrogen outlet pipe, and its measuring range is 0 to 2 bar.

[0033] Under normal conditions, the working pressure of the gas supply pipeline 5 is 0.9 bar, and the fluctuation range is 0.85 bar to 0.92 bar. The alarm threshold is set to 0.95 bar. If the measured value of the pressure sensor A7 exceeds the threshold, it means that the gas supply pipeline 5 is leaking.

[0034] The pressure sensor A7 and two gas monitors 6 are located in the nitrogen outlet pipeline. The two gas monitors 6 are hydrogen, deuterium and tritium monitors, which are used to detect the gas volume concentration of hydrogen and deuterium, and the radioactive activity concentration of tritium, respectively. The alarm thresholds of the hydrogen and deuterium monitors are set to 1% VOL, and the alarm threshold of the tritium monitor is set to 1E8 Bq / m 3 .

[0035] If any one of the two gas monitors 6 exceeds the corresponding alarm threshold, it means that the gas supply pipeline 5 is leaking.

[0036] like Figure 2 As shown, a pneumatic isolation valve B10 is installed on each bypass pipeline 3 to open or close the bypass pipeline. A pneumatic isolation valve A9 is installed on the pipeline where the nitrogen injection port 2 is located to open or close the injection pipeline.

[0037] The air supply pipeline 5 is divided into three parallel branches corresponding to each feeding valve box 1, which are two air supply pipelines 14 and one exhaust pipeline 15; the two air supply pipelines 14 are installed with pneumatic isolation valves D12 and pneumatic isolation valves C11, the exhaust pipeline 15 is installed with a pneumatic isolation valve E13, and a pressure sensor B8 is installed on the pipeline at the confluence of the three parallel branches.

[0038] The gas supply pipe 5 enters the valve box from the top of the feeding valve box 1, the bypass pipe 3 is connected to the manifold of the containment pipe 4 from the top of the feeding valve box 1, and the nitrogen injection port 2 is located near the bottom of the feeding valve box 1. Considering that the leaked gas hydrogen is lighter than nitrogen and is easy to gather at the top of the valve box, nitrogen is injected from the nitrogen injection port 2 into the interlayer space of the feeding valve box 1 from bottom to top, and then enters the interlayer space between the containment pipe 4 and the gas supply pipe 5 from the bypass pipe 3, and flows along the containment pipe 4 through the gas monitor 6 and then flows to the outlet.

[0039] In this embodiment, based on deflagration safety and radioactive safety, the alarm threshold of hydrogen and deuterium monitors is set to 1%VOL, and the measurement range is 0-4%VOL; the alarm threshold of tritium monitor is set to 1E8Bq / m 3 , measuring range 1E4Bq / m 3 ~1E10Bq / m 3 Under normal conditions, the display values ​​of the hydrogen, deuterium and tritium monitors are all 0. If the measured value exceeds the set threshold, it means that a leakage event that may endanger safety has occurred in the corresponding gas pipeline.

[0040] The air supply pipe 14 and the exhaust pipe 15 on the air supply pipe 5, the air supply pipe 14 can be one or more, and two air supply pipes are taken as an example in the figure. After the multiple air supply pipes 14 are merged in the valve box, they are connected to the injection line for supplying air to the vacuum chamber. Another branch is connected to the exhaust pipe 15, and the exhaust pipe 15 is in a vacuum state under normal circumstances, and the vacuum degree is 1Pa~100Pa.

[0041] The pneumatic isolation valve C11 is used to select the feeding gas, which is opened and closed according to the experimental requirements and is usually closed. The pneumatic isolation valve D12 is used for leak location and is usually in the normally open state. Another pressure sensor B8 is located at the confluence of the gas supply pipeline. Under normal circumstances, the pressure range is 0.3bar to 0.4bar.

[0042] When the measured value of any one of the two gas monitors 6 or the pressure sensor A7 exceeds the corresponding alarm threshold, the pneumatic isolation valve D12 in all the feeding valve boxes 1 is immediately and remotely closed, and then the pneumatic isolation valve C11 and the pneumatic isolation valve E13 are opened. When the measured value of the pressure sensor B8 drops below 0.01 bar, the pneumatic isolation valve E13 is closed, and the signal of the corresponding pressure sensor B8 in each feeding valve box 1 is continuously monitored in real time. If the signal of a certain pressure sensor B8 rises to 0.1 bar (positioning alarm value) and continues to rise, it indicates that the corresponding feeding valve box 1 is leaking, thereby realizing the positioning of the leaking valve box.

Claims

1. A remote leakage monitoring and positioning system for a fusion device charging valve box, comprising a gas supply pipeline (5) and an external containment tube (4), characterized in that: The containment pipe (4) is provided with a nitrogen outlet pipeline and a plurality of manifolds, each manifold end is provided with a feeding valve box (1), and an inlet is processed on the lower side wall of each feeding valve box (1) as a nitrogen injection port (2); the gas supply pipeline (5) is provided with one more gas supply branch pipe than the number of manifolds, one gas supply branch pipe is located in the nitrogen outlet pipeline, and the other gas supply branch pipes are respectively located in the corresponding manifolds and extend into the corresponding feeding valve box (1); the manifold is provided with a bypass pipeline (3) which connects the nitrogen outlet of the feeding valve box (1) and the interior of the manifold; The gas supply branch pipes in the manifold are a plurality of parallel branches branched from the gas supply pipe (5), which are N gas supply pipes (14) and an exhaust pipe (15); The N air supply pipelines (14) are each provided with a pneumatic isolation valve D (12) and a pneumatic isolation valve C (11), the exhaust pipeline (15) is provided with a pneumatic isolation valve E (13), and a pressure sensor B (8) is provided on the pipeline at the confluence of all parallel branches; A pressure sensor A (7) is provided on the gas supply branch pipe of the nitrogen outlet pipeline; When the measured value of pressure sensor A (7) exceeds 0.95 bar, all pneumatic isolation valves D (12) are closed, and pneumatic isolation valves C (11) and E (13) are opened until the measured value of pressure sensor B (8) drops below 0.01 bar, and then pneumatic isolation valve E (13) is closed. If the signal of a pressure sensor B (8) rises to 0.1 bar and continues to rise, it is determined that the corresponding feed valve box (1) is leaking; The bypass pipeline (3) is provided with a pneumatic isolation valve B (10) for opening or closing the bypass pipeline.

2. A remote leakage monitoring and positioning system for a fusion device charging valve box as claimed in claim 1, characterized in that: The pipeline where the nitrogen injection port (2) is located is provided with a pneumatic isolation valve A (9) for opening or closing the injection pipeline.

3. A remote leakage monitoring and positioning system for a fusion device charging valve box as claimed in claim 1, characterized in that: A gas monitor (6) is provided on the gas supply branch pipe of the nitrogen outlet pipeline.

4. A remote leakage monitoring and positioning system for a fusion device charging valve box as claimed in claim 3, characterized in that: When the volume concentration of hydrogen or deuterium detected by the gas monitor (6) exceeds 1%VOL or the radioactivity concentration of tritium detected exceeds 1E8Bq / m 3 , all pneumatic isolation valves D (12) are closed, and pneumatic isolation valves C (11) and pneumatic isolation valves E (13) are opened until the measured value of pressure sensor B (8) drops below 0.01 bar, and pneumatic isolation valve E (13) is closed. If the signal of a pressure sensor B (8) rises to 0.1 bar and continues to rise, it is determined that the corresponding feed valve box (1) is leaking.

5. A remote leakage monitoring and positioning system for a fusion device charging valve box as claimed in claim 1, characterized in that: The measuring range of the pressure sensor B (8) is 0~1 bar, and the measuring range of the pressure sensor A (7) is 0~2 bar.

6. A remote leakage monitoring and positioning system for a fusion device charging valve box as claimed in claim 1, characterized in that: The exhaust pipe (15) is in a vacuum state, with a vacuum degree of 1Pa-100Pa.

7. A remote leakage monitoring and positioning system for a fusion device charging valve box as claimed in claim 1, characterized in that: The working pressure range of the gas supply pipeline (5) is 0.85 bar to 0.92 bar.

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