A gas permeation testing device and method for metal pipes and cladding modules

Abstract

The present invention discloses a gas permeation test device and method for metal pipelines and cladding modules, which belongs to the field of fusion component measurement technology, including a heating device, an upstream vacuum control system, a downstream vacuum control system, and an external gas shielding system for non-test parts of the gas pipe. The upstream metal plate is connected with a gas input pipeline and an upstream vacuum control system pipeline. The sample is connected to a steel pipe of the gas shielding system through a double ferrule. The steel pipe extends to the downstream metal plate and enters the downstream end. The downstream metal plate is also connected with a vacuum control system of the gas shielding system. The gas shielding system consists of a steel cylinder, a steel pipe inserted through the steel cylinder, and a vacuum control system. The present invention also proposes a gas permeation test method. The device of the present invention has a simple structure and high detection accuracy, solves the technical problem that gas permeation of pipelines and modules cannot be detected, and has great application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of fusion component measurement, and in particular relates to a gas permeation testing device and method for a metal pipeline and a cladding module. Background Art

[0002] Existing fusion experimental devices and future fusion reactors require that the blanket can produce tritium to help the fusion reactor achieve the function of tritium self-sustaining. The tritium produced in the blanket will penetrate into the structural materials including the cooling water pipes, and then be retained in the structural materials. The penetration and retention of hydrogen isotopes in the blanket structural materials is directly related to the economy and safety of the fusion reactor, and affects the possibility of tritium self-sustaining. To study the hydrogen isotope penetration parameters of fusion structural materials, it is necessary to expose the samples to a hydrogen isotope atmosphere for analysis.

[0003] The hydrogen isotope gas permeation experiment is an important step in studying the permeation behavior of hydrogen isotopes. At present, small flat samples are generally used in China and internationally to analyze the permeation of hydrogen isotopes in cladding structural materials. The problems of this method are: 1. It is impossible to measure the permeation behavior of hydrogen isotopes in the entire pipeline and module components. Summary of the invention

[0004] The object of the present invention is to provide a gas permeation device and method for a metal pipeline and a cladding module, so as to solve the limitations of the prior art hydrogen isotope permeation experiment in measuring the permeation of pipelines and cladding modules.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The invention provides a gas permeation testing device for a metal pipeline and a cladding module. The metal pipeline and the cladding module include a cooling water pipe in a fusion reactor cladding and a module constituting the cladding. The gas permeation testing device includes a heating device, an upstream vacuum control system, a downstream vacuum control system, and a gas shielding system of a non-testing part. The non-testing part is a steel pipe with two ends opened. One end of the steel pipe inserted through a steel cylinder is sealed and connected to a sample through a double ferrule, and the other end of the steel pipe is connected to a downstream vacuum control system pipeline. A first metal plate on one side of the steel cylinder is connected to a gas shielding system vacuum pump group pipeline and a downstream vacuum control system pipeline. The gas shielding system vacuum pump group pipeline is sequentially connected to a second valve, a second vacuum gauge, a second molecular pump and a second mechanical pump. The downstream vacuum control system pipeline is sequentially connected to a third valve, a third vacuum gauge, a mass spectrometer, a third molecular pump and a third mechanical pump. The first metal plate on one side of the steel cylinder forms a seal with a quartz tube through a rubber ring. The left side of the quartz tube is isolated from the outside by the second metal plate. The second metal plate is connected to an inflation pipe and an upstream vacuum control system pipeline. The upstream vacuum control system pipeline is sequentially connected to a first vacuum gauge, a first valve, a first molecular pump and a first mechanical pump.

[0007] A gas permeation test method for a metal pipe and a cladding module, the method comprising the following steps:

[0008] S1: The pipeline and cladding module samples are sealed and connected to the pipeline at the non-test position through a double ferrule, and placed in a quartz tube. The two ends of the quartz tube are sealed and connected to the first metal plate and the second metal plate through sealing rings respectively;

[0009] S2: Close the fourth valve, open the first valve, the second valve and the third valve, start the first mechanical pump, the second mechanical pump and the third mechanical pump, the first molecular pump, the second molecular pump and the third molecular pump, wait until the vacuum degree detected by the first vacuum gauge, the second vacuum gauge and the third vacuum gauge reaches a predetermined value, turn on the heating furnace, and adjust the sample temperature;

[0010] S3: Wait until the pressure P1 and temperature T1 in the sample chamber are stable for a short time without change and the vacuum degree of the third vacuum gauge is better than 10 -4 pa, turn on the heating furnace, heat the sample to the preset temperature and keep it warm for 10 minutes, turn on the mass spectrometer to record the background signal, and after the background signal is stable, close the first valve, open the fourth valve, and inflate the sample chamber through the inflation tube;

[0011] S4: Observe the pressure value in the sample chamber by the first vacuum gauge, and when a certain pressure is reached, close the fourth valve to stop the inflation;

[0012] S5: The downstream mass spectrometer detects the gas flux that permeates the sample. After a certain period of time, the gas flux remains stable. The flux changes are observed, and the mass spectrometer is turned off after recording the data.

[0013] S6: Open the first valve, extract the gas in the sample chamber, close the heating furnace, and stop heating.

[0014] The metal pipe and cladding module gas permeation device provided by the present invention is used to measure the hydrogen isotope permeation behavior of the metal pipe and cladding module samples constituting the cladding of the fusion device. First, a double ferrule joint is used to connect the metal pipe and cladding module to be measured to the pipe. The pipe is inserted through the steel cylinder, and the vacuum degree is controlled by a pump group inside the pipe to reduce the gas permeation effect in non-test parts during measurement and improve the measurement accuracy. Samples of different sizes and shapes can be replaced according to needs, and a heating furnace is used to heat the sample. The actual temperature of the sample is recorded by a thermocouple. The second metal plate is connected to an inflation tube and an upstream vacuum control system pipeline. The inflation tube can be connected to an external gas cylinder, and the upstream vacuum control system pipeline includes a mechanical pump, a molecular pump, and a vacuum gauge. Before measurement, the sample chamber (inside the quartz tube) and the downstream end are evacuated to 10 -4 pa and 10 - 5pa, and then turn on the mass spectrometer. When the data is stable, close the upstream pump group and valve, and fill the sample chamber with gas at a certain pressure through the inflation tube. Due to a certain pressure difference inside and outside the sample, the gas will penetrate the sample and enter the downstream end through the sample. The data analysis and processing based on the mass spectrometer can obtain the penetration parameters of hydrogen isotopes in the metal pipe and cladding module samples.

[0015] The gas shielding system can greatly reduce the penetration of gas in non-tested areas and improve the accuracy of measurement. The heating furnace controls the program temperature through an intelligent instrument, and heats the sample to a specified temperature by changing the current to control the heating wire. The thermocouple records the actual temperature of the sample.

[0016] In the present invention, the metal pipe and cladding module samples to be tested are sealed and connected to the pipe in the gas shielding system by using a double ferrule, and the thermocouple is placed on one side of the metal pipe and cladding module samples, so that the actual temperature of the test sample can be recorded under the heating program of the heating furnace. In the downstream section of the experiment, the permeation gas signal is directly transmitted to the computer through a high-resolution mass spectrometer.

[0017] Compared with the gas permeation test method in the prior art, the present invention has the following advantages:

[0018] 1. Gas permeation test can be directly carried out on the whole metal pipe / cladding module sample;

[0019] 2. The sample can be vacuum-sealed well during the experiment, and the size range of the test sample is wider;

[0020] 3. A gas shielding system for non-test parts is designed to greatly reduce the error caused by gas penetration in non-test parts;

[0021] 4. The structure is simple, the system is more convenient to build, and it has good economic efficiency and great application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the device of the present invention.

[0023] Among them, the first mechanical pump 1, the first molecular pump 2, the first valve 3, the first vacuum gauge 4, the second metal plate 5, the quartz tube 6, the fourth valve 7, the heating furnace 8, the sample 9, the thermocouple 10, the double ferrule 11, the steel pipe 12, the steel cylinder 13, the first metal plate 14, the second valve 15, the second vacuum gauge 16, the second mechanical pump 17, the second molecular pump 18, the third valve 19, the third vacuum gauge 20, the mass spectrometer 21, the third molecular pump 22, the third mechanical pump 23, the inflation tube 24, the upstream vacuum control system pipeline 25, the gas shielding system vacuum pump group pipeline 26, and the downstream vacuum control system pipeline 27. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0025] like Figure 1 As shown, a gas permeability testing device for metal pipes and cladding modules is used to measure the hydrogen isotope permeability of metal pipes and cladding modules constituting the cladding of a fusion device in a hydrogen isotope environment. First, the sample 9 to be measured is sealed and fixed to one end of the pipe fitting of the gas shielding system through a double ferrule 11 to achieve an isolating and sealing effect during measurement. A thermocouple is closely arranged on one side of the sample 9. The metal sample can be heated as required during the experiment. The upstream vacuum control system pipeline 25 is connected to the sample chamber, the gas shielding system vacuum pump group pipeline 26 is connected to the steel cylinder 13 of the gas shielding system, and the downstream vacuum control system pipeline 27 is connected to the steel pipe 12 in the steel cylinder 13 of the gas shielding system to form the downstream end. Before measurement, first close the fourth valve 7, open the first valve 3, the second valve 15, and the third valve 19 to evacuate the sample chamber, the steel cylinder 13, and the downstream end, and the vacuum degree of the sample chamber is evacuated to 10 -3 pa, the downstream end is vacuumed to 10 -4 pa, then turn on the power of the heating furnace 8 to heat the sample to the preset temperature and stabilize it for a period of time until the sample temperature is stable, and finally turn on the mass spectrometer 21 to record the background signal when no gas is injected. After the signal is stable, close the first valve 3, open the fourth valve 7, fill the sample chamber with gas, and detect the pressure of the filled gas through the vacuum gauge. After the gas pressure reaches the preset value, close the fourth valve 7 to stop the gas filling. Due to the pressure difference between the inside and outside of the sample 9, the gas will penetrate the sample to the downstream end. Based on the data analysis and processing of the mass spectrometer 21, the permeation parameters of hydrogen isotopes in the metal pipes and cladding module samples constituting the cladding of the fusion device are obtained. Sample 9 is a metal sample.

[0026] In the present invention, the vacuum degree of the mass spectrometer 21 during operation needs to be better than 10 -2 pa. The vacuum control system includes a mechanical pump and a molecular pump. The heating furnace will heat the sample to the specified temperature according to the preset temperature value and heating rate.

[0027] In the present invention, the interior of the sealed space formed by the quartz tube 6 and the first metal plate 14 and the second metal plate 5 on both sides, the sample 9 and the exterior of the steel cylinder 13 constitute the measurement upstream section.

[0028] The present invention is used for the analysis of hydrogen isotope permeation behavior of metal pipes and blanket module samples in current fusion devices and future fusion reactor blankets. Before work, three groups of pumps are used to evacuate the upstream end, gas shielding system, and downstream end to a certain vacuum degree, and then the heating furnace is turned on. After the sample temperature rises to a specified temperature, the mass spectrometer is turned on to detect the gas signal before and after gas injection. The mass spectrometer data results can be viewed online through a display connected to the mass spectrometer. After the experiment is completed, the mass spectrometer is turned off, and the gas at the upstream end is extracted to maintain vacuum, and the experimental data can be analyzed and processed.

[0029] Specifically, a gas permeability testing device for a metal pipe and a cladding module, the metal pipe and the cladding module include a cooling water pipe in a fusion reactor cladding and a tritium resistance test module for a flow channel in the cladding, the metal pipe and the cladding module gas permeability testing device includes a heating device, an upstream vacuum control system, a downstream vacuum control system, and a gas shielding system for a non-testing part, wherein the non-testing part is a steel pipe 12 with openings at both ends, the steel pipe 12 passes through one end of a steel cylinder 13 and is sealed and connected to a sample 9 through a double ferrule 11, the other end of the steel pipe 12 is connected to the downstream, and a first metal plate 14 on one side of the steel cylinder 13 is connected to a gas shielding system vacuum pump group pipeline 26 and a downstream vacuum control system pipeline 27, the gas shielding system vacuum pump group pipeline 26 is connected with the second valve 15, the second vacuum gauge 16, the second molecular pump 18 and the second mechanical pump 17 in sequence, the downstream vacuum control system pipeline 27 is connected with the third valve 19, the third vacuum gauge 20, the mass spectrometer 21, the third mechanical pump 23 and the third molecular pump 22 in sequence, the first metal plate 14 on one side of the steel cylinder 13 forms a seal with the quartz tube 6 through a rubber ring, the left side of the quartz tube 6 is isolated from the outside by the second metal plate 5, the second metal plate 5 on the left side of the quartz tube 6 is connected with the charging tube 24 and the upstream vacuum control system pipeline 25, the upstream vacuum control system pipeline 25 is connected with the first vacuum gauge 4, the first valve 3, the first molecular pump 2 and the first mechanical pump 1 in sequence. The charging tube 24 can be connected to an external gas bottle, and the charging tube is equipped with a fourth valve 7.

[0030] The second metal plate 5 is connected with an air filling tube 24 and an upstream vacuum control system pipeline 25, and the upstream vacuum control system pipeline 25 is sequentially connected with a first vacuum gauge 4, a first valve 3, a first molecular pump 2 and a first mechanical pump 1. The quartz tube 6 is placed in a heating furnace 8, and the heating furnace 8 is used to control the temperature of the sample 9 inside the quartz tube 6. The thermocouple 10 is close to the sample 9 and is used to record the actual temperature of the sample 9. One end of the steel pipe 12 is connected to the sample 9, and the other end extends into the downstream detection end, which is directly welded to the first metal plate 14. The downstream detection end is sequentially connected with a third valve 19, a third vacuum gauge 20, a mass spectrometer 21, a third mechanical pump 23 and a third molecular pump 22.

[0031] The first metal plate 14 is connected to the steel pipe 12 , the steel cylinder 13 , the gas shielding system vacuum pump group pipeline 26 and the downstream vacuum control system pipeline 27 .

[0032] Specifically, the present invention also provides a gas permeation test method for a metal pipe and a cladding module, comprising the following steps:

[0033] S1: The pipeline and cladding module samples are sealed and connected to the pipeline at the non-test position through a double ferrule, and placed in a quartz tube. The two ends of the quartz tube are sealed and connected to the first metal plate and the second metal plate through sealing rings respectively;

[0034] S2: Close the fourth valve 7, open the first valve 3, the second valve 15 and the third valve 19, start the first mechanical pump 1, the second mechanical pump 17 and the third molecular pump 22, the first molecular pump 2, the second molecular pump 18 and the third mechanical pump 23, wait for the first vacuum gauge 4, the second vacuum gauge 16 and the third vacuum gauge 20 to detect that the vacuum degree reaches a predetermined value, turn on the heating furnace 8, and adjust the sample temperature.

[0035] S3: Wait until the pressure P1 and temperature T1 in the sample chamber are stable and unchanged and the vacuum degree of the third vacuum gauge 20 is better than 10 -4 pa, turn on the heating furnace, heat the sample to the preset temperature and keep it warm for 10 minutes, turn on the mass spectrometer 21 to record the background signal, and after the background signal is stable, close the first valve 3, open the fourth valve 7, and inflate the sample chamber through the inflation tube.

[0036] S4: The pressure value in the sample chamber is recorded by observing the first vacuum gauge 4. When a certain pressure is reached, the fourth valve 7 is closed to stop the inflation.

[0037] S5: The downstream mass spectrometer 21 detects the gas flux permeating through the sample 9. After a certain period of time, the gas flux remains stable, and the flux change is observed. After recording the data, the mass spectrometer 21 is turned off;

[0038] S6: Open the first valve 3 to extract the gas in the sample chamber, close the heating furnace 8, and stop heating.

[0039] Selection of mass spectrometer in the present invention: Mass spectrometer is the main detection means of this scheme, that is, a type of instrument that separates and detects the composition of substances according to the mass difference of atoms, molecules or molecular fragments of substances based on the principle that charged particles can be deflected in an electromagnetic field. The main function of the present invention is to separate and detect substances with different atomic masses and analyze the types of substances. In the process of measuring the gas permeation experiment of metal pipes / cladding modules, the gas permeation characteristics of the material are mainly studied by detecting the relative size of the gas type and the permeation amount after penetrating the sample. The model and brand of the mass spectrometer are selected according to the type of target substance to be detected. There is no requirement for the model and brand of the mass spectrometer in the present invention, and it can be selected according to the needs.

[0040] Selection of vacuum pump group in the present invention: Under actual fusion working conditions, the working pressure is generally low, and the maximum working pressure of the mass spectrometer in working mode is generally 10 -2 Pa, the vacuum degree at the upstream end should reach a higher level as possible to ensure the purity of the gas filled in. The vacuum pump group mainly provides a good working background for the mass spectrometer and greatly guarantees the purity of the gas filled in the upstream end. There is no clear requirement for the model and brand of the vacuum pump group, which can be adjusted according to independent experimental needs.

[0041] Selection of thermocouple in the present invention: Thermocouple is a commonly used temperature measuring element in temperature measuring instruments. It directly measures temperature and converts temperature signals into thermoelectric potential signals, which are then converted into displayed temperature through detection circuits. Thermocouples are used to measure temperature signals on the surface of samples and then analyze the characteristics of materials that change with temperature.

[0042] Selection of the heating furnace in the present invention: The main function of the heating furnace is to heat the sample to a specified temperature. The heating temperature of the heating furnace is related to the temperature range to be studied.

Claims

1. A gas permeation test device for a metal pipe and a cladding module, wherein the metal pipe and the cladding module include a cooling water pipe in a fusion reactor cladding and a module constituting the cladding, characterized in that: The gas permeation testing device includes a heating device, an upstream vacuum control system, a downstream vacuum control system, and a gas shielding system for a non-testing part. The non-testing part is a steel pipe with two ends opened. One end of the steel pipe that passes through the steel cylinder is sealed and connected to the sample through a double ferrule, and the other end of the steel pipe is connected to the downstream vacuum control system pipeline. The first metal plate on one side of the steel cylinder is connected to a gas shielding system vacuum pump group pipeline and a downstream vacuum control system pipeline. The gas shielding system vacuum pump group pipeline is sequentially connected to a second valve, a second vacuum gauge, a second molecular pump and a second mechanical pump. The downstream vacuum control system pipeline is sequentially connected to a third valve, a third vacuum gauge, a mass spectrometer, a third molecular pump and a third mechanical pump. The first metal plate on one side of the steel cylinder forms a seal with the quartz tube through a rubber ring. The left side of the quartz tube is isolated from the outside world by the second metal plate. The second metal plate is connected to an inflation tube and an upstream vacuum control system pipeline. The upstream vacuum control system pipeline is sequentially connected to a first vacuum gauge, a first valve, a first molecular pump and a first mechanical pump.

2. A gas permeation testing device for a metal pipe and a cladding module according to claim 1, characterized in that: The inflation tube is externally connected to a gas bottle and is provided with a fourth valve.

3. A gas permeation testing device for a metal pipe and a cladding module according to claim 1, characterized in that: The quartz tube is placed in a heating furnace, which is used to control the temperature of the sample inside the quartz tube. The thermocouple is close to the sample and is used to record the actual temperature of the sample.

4. A gas permeation testing device for a metal pipe and a cladding module according to claim 1, characterized in that: The downstream vacuum control system piping is welded directly to the first metal plate.

5. A method for testing a gas permeability testing device for a metal pipe and a cladding module according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: S1: The pipeline and cladding module samples are sealed and connected to the pipeline at the non-test position through a double ferrule, and placed in a quartz tube. The two ends of the quartz tube are sealed and connected to the first metal plate and the second metal plate through sealing rings respectively; S2: Close the fourth valve, open the first valve, the second valve and the third valve, start the first mechanical pump, the second mechanical pump and the third mechanical pump, the first molecular pump, the second molecular pump and the third molecular pump, wait until the vacuum degree detected by the first vacuum gauge, the second vacuum gauge and the third vacuum gauge reaches a predetermined value, turn on the heating furnace, and adjust the sample temperature; S3: Wait until the pressure P1 and temperature T1 in the sample chamber are stable and the vacuum degree of the third vacuum gauge is better than 10 -4 At pa, the heating furnace is turned on, the sample is heated to a preset temperature and kept warm for 10 min, the mass spectrometer is turned on to record the background signal, and after the background signal is stable, the first valve is closed, the fourth valve connected to the inflation tube is opened, and gas is inflated into the sample chamber through the inflation tube; S4: Observe the pressure value in the sample chamber recorded by the first vacuum gauge. When a certain pressure is reached, close the fourth valve to stop the inflation. S5: The downstream mass spectrometer detects the gas flux that permeates the sample. After a certain period of time, the gas flux remains stable. The flux changes are observed, and the mass spectrometer is turned off after recording the data. S6: Open the first valve, extract the gas in the sample chamber, close the heating furnace, and stop heating.

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