Test research system for influence of non-condensable gas in nuclear power station pipeline

Abstract

The invention discloses a test and research system for influence of non-condensable gas in a nuclear power station pipeline, and relates to the technical field of fatigue analysis and research of nuclear power station pipelines. The test research system for the influence of the non-condensable gas in the nuclear power station pipeline comprises a test pipe section, a drainage device and a chemical analyzer, the test pipe section is provided with a horizontal pipeline; one end of the drainage device is communicated with the horizontal pipeline, and the drainage device is used for separating gaseous substances in a gas-liquid mixture in the horizontal pipeline without losing liquid cooling water; and the chemical analyzer is communicated with the horizontal pipeline and is used for measuring and analyzing chemical components of substances in the horizontal pipeline in real time. The invention provides a test research system for influence of non-condensable gas in a nuclear power station pipeline. The test research system can be used for evaluating the output of the non-condensable gas under different working conditions and the influence of the non-condensable gas on a test. The drainage device is used for measuring the generation amount of non-condensable gas under different working conditions; and meanwhile, non-condensable gas can be reversely added by utilizing the drainage device, and the influence of the non-condensable gas on the experimental research of the descending horizontal pipe of the nuclear power plant is quantitatively explored.

Description

Technical Field

[0001] This invention relates to the field of fatigue analysis research technology for nuclear power plant pipelines, and in particular to a test research system for the influence of non-condensable gases in nuclear power plant pipelines. Background Technology

[0002] In recent years, fatigue analysis of T-type pipes in nuclear power plants has attracted widespread attention from researchers, especially structures where one end is blocked due to valves or special pipe designs; these structures are also known in the industry as "dead pipe sections." When a nuclear power plant is operating normally, the fluid in the main pipes flows at high temperatures and velocities; under the influence of factors such as turbulent infiltration, thermal stratification, and thermal circulation, fatigue often occurs due to temperature fluctuations in the fluid within the dead pipe section.

[0003] During the experimental research, it was found that non-condensable gases (mainly air) easily formed in the dead pipe section. The main reasons are twofold: 1) The special structure of the downstream horizontal pipe caused a certain amount of non-condensable gas to accumulate in the horizontal pipe section at the initial stage of the experiment; 2) Changes in the solubility of air in water led to the precipitation of a certain amount of non-condensable gas. According to Henry's Law, the solubility of air decreases as the fluid temperature in the dead pipe section increases during the experiment, and increases as the loop pressure increases. When the increase in air solubility is less than the decrease, air precipitates due to the decrease in solubility. Figure 1 The figure shows the air solubility at different temperatures. With an initial back pressure of 0.1 MPa and a temperature of 20°C, the reference value for air solubility decreases from 18.4 ml / 100g to 14.0 ml / 100g when the back pressure and temperature rise to 0.4 MPa and 140°C, respectively. Excessive non-condensable gases can accumulate in dead-end sections, forming large gas clouds. The instability of these gas clouds can cause fluctuations in the liquid within the downflow horizontal tube, severely impacting experimental results and potentially leading to erroneous conclusions. Therefore, when conducting experimental studies on nuclear power plant downflow horizontal tubes, it is necessary to assess the amount of non-condensable gases generated under the corresponding operating conditions and their impact on the experiment.

[0004] Therefore, it is necessary to propose a system suitable for experimental research on the influence of non-condensable gases in the downflow horizontal pipe of a pressurized water reactor nuclear power plant. Summary of the Invention

[0005] The main objective of this invention is to provide a test system for studying the effects of non-condensable gases in nuclear power plant pipelines, aiming to assess the amount of non-condensable gases generated under different operating conditions and their impact on the test.

[0006] To achieve the above objectives, this invention proposes a system for experimental research on the influence of non-condensable gases in nuclear power plant pipelines, the system comprising: The test section has horizontal pipes; A hydrophobic device, one end of which is connected to the horizontal pipe, is used to separate gaseous substances from the gas-liquid mixture within the horizontal pipe without losing liquid cooling water; and A chemical analyzer, connected to the horizontal pipe, is used to measure and analyze the chemical composition of substances within the horizontal pipe in real time.

[0007] Optionally, the hydrophobic device has multiple components arranged linearly. Each hydrophobic device includes a hydrophobic tube, a hydrophobic membrane, a piston body, and a piston cylinder. One end of the hydrophobic tube is connected to the highest point of the horizontal pipe, and the other end of the hydrophobic tube is connected to the piston cylinder. The piston body is movably disposed within the piston cylinder. The hydrophobic membrane is disposed within the hydrophobic tube and is used to separate the gas from the gas-liquid mixture without reducing the liquid component.

[0008] Optionally, the maximum back pressure that the hydrophobic membrane can withstand is P1, satisfying the following relationship: P1≥0.4MPa; and / or The highest temperature that the hydrophobic membrane can withstand is T1, which satisfies the following relationship: T1≥140℃.

[0009] Optionally, the shape of the hydrophobic membrane is adapted to the shape of the connection between the hydrophobic pipe and the horizontal pipe. The hydrophobic membrane is an alumina-based hydrophobic ceramic membrane, a zirconia-based hydrophobic ceramic membrane, a silicon carbide-based hydrophobic ceramic membrane, a polytetrafluoroethylene membrane, a polyvinylidene fluoride membrane, a polyether ether ketone membrane, or a metal sintered hydrophobic membrane.

[0010] Optionally, the back pressure of the piston cylinder is ambient atmospheric pressure, suitable for horizontal placement with respect to the ground; the piston cylinder is graduated, with a measurement range of not less than 2000ml and a minimum graduation of not more than 10ml; and / or The drain pipe is equipped with a needle valve, which is used to control the separation rate of non-condensable gases by adjusting the opening degree.

[0011] Optionally, the hydrophobic device further includes a drive mechanism, which is drivenly connected to the piston body and is used to drive the piston body to move in the opposite direction to quantitatively inject working fluid into the horizontal pipe.

[0012] Optionally, the driving pressure of the driving mechanism is P2, which satisfies the following relationship: |P2-P1|≤0.4MPa.

[0013] Optionally, the system further includes an air-rich water system, with the two ends of the test pipe section being the two ends of a stainless steel pipe loop, and the air-rich water system being connected to the stainless steel pipe loop; the air-rich water system includes an air-rich water tank for containing cooling water and an agitator and a heater located in the air-rich water tank, the air-rich water tank being adapted to be connected to the ambient atmosphere, the heater being used for constant temperature control of the cooling water, and the agitator being used for fully mixing air with the cooling water to form cooling water with fully dissolved air.

[0014] Optionally, the system may also include a voltage regulator, cooler, electric heater, flow meter, variable frequency pump, rectifier, filter, and temperature and pressure measuring instruments disposed on the stainless steel pipeline circuit.

[0015] Optionally, the chemical analyzer has two or more measurement channels, which measure and provide real-time feedback at designated positions at both ends of the horizontal pipe. The measurement parameters of the chemical analyzer include at least one of dissolved oxygen concentration, dissolved hydrogen concentration, and metal ion concentration.

[0016] In the technical solution of this invention, the experimental research system for the influence of non-condensable gases in nuclear power plant pipelines includes a test pipe section, a condensate drain device, and a chemical analyzer. The test pipe section has a horizontal pipe. One end of the condensate drain device is connected to the horizontal pipe and is used to separate gaseous substances from the gas-liquid mixture within the horizontal pipe without losing liquid cooling water. The chemical analyzer is connected to the horizontal pipe and is used to measure and analyze the chemical composition of the substances within the horizontal pipe in real time. It can be understood that this invention uses a condensate drain device to separate non-condensable gases from the gas-liquid mixture within the horizontal pipe of the test pipe section, thereby enabling the measurement of the amount of non-condensable gases generated under different operating conditions. This invention uses a chemical analyzer to achieve real-time measurement and analysis of the chemical composition of the substances within the horizontal pipe.

[0017] Furthermore, this invention enables the measurability of non-condensable gases. The horizontal pipeline is equipped with multiple hydrophobic devices, which can measure the amount of non-condensable gas collected at different locations in the horizontal pipeline in real time. This method can not only determine whether there is initial accumulation of non-condensable gases, but also whether dissolved air in the cooling water is released due to temperature rise, thereby providing a reference for the reasonable setting of test boundary conditions such as main pipeline temperature and pressure.

[0018] The experimental research system for the impact of non-condensable gases in nuclear power plant pipelines of the present invention supports the quantitative investigation of the impact of non-condensable gases. The piston gas cylinder of the condensate drain device is equipped with a driving mechanism. When the cylinder is filled with gas, the driving mechanism can be used to quantitatively inject gas into the condensate drain pipes at different positions of the horizontal pipeline of the branch pipeline, thereby conducting a quantitative research experiment on the impact of non-condensable gases on the downstream horizontal pipe of the nuclear power plant.

[0019] The experimental research system for the impact of non-condensable gases in nuclear power plant pipelines of this invention supports water quality detection at key locations throughout the entire operation process. It is equipped with a chemical composition analysis system that can measure and provide real-time feedback on parameters such as dissolved oxygen concentration, dissolved hydrogen concentration, and metal ion concentration at designated locations within the branch pipeline. The dissolved oxygen concentration can be used to corroborate the amount of dissolved air released into the cooling water, and the dissolved hydrogen concentration and metal ion concentration can be used to determine the corrosion status at key locations. Furthermore, the intensity of eddies can be determined by the changes in dissolved hydrogen concentration and metal ion concentration per unit time. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a graph showing the change in air solubility of cooling water at different temperatures; Figure 2 This is a schematic diagram of an embodiment of the experimental research system for the influence of non-condensable gases in nuclear power plant pipelines according to the present invention; Figure 3 This is a schematic diagram of the horizontal pipe and drainage device in one embodiment of the experimental research system for the influence of non-condensable gases in nuclear power plant pipelines of the present invention. Figure 4 This is a schematic diagram of the hydrophobic device in one embodiment of the experimental research system for the influence of non-condensable gases in nuclear power plant pipelines according to the present invention; Figure 5 This is a schematic diagram of the distribution of different amounts of non-condensable gases in a horizontal pipeline in one embodiment of the experimental research system for the influence of non-condensable gases in nuclear power plant pipelines according to the present invention.

[0022] Explanation of icon numbers: 10. Test pipe section; 20. Drainage device; 30. Chemical analyzer; 111. Horizontal pipe; 21. Drainage pipe; 22. Hydrophobic membrane; 23. Piston body; 24. Piston gas cylinder; 25. Drive mechanism; 41. Rich gas tank; 42. Stirrer; 43. Volumetric pump; 51. Voltage regulator; 52. Cooler; 53. Electric heater; 54. Flow meter; 55. Variable frequency pump; 56. Rectifier; 57. Filter; 200a. Cooling water; 200b. Non-condensable gas.

[0023] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0026] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. The word "and / or" throughout the text means including three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. The technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0028] This invention proposes a test system for studying the effects of non-condensable gases in nuclear power plant pipelines, which is applicable to the test study of the effects of non-condensable gases in the downflow horizontal pipes of pressurized water reactor nuclear power plants.

[0029] Reference Figures 2 to 5In one embodiment of the present invention, the experimental research system for the influence of non-condensable gases in nuclear power plant pipelines includes a test pipe section 10, a hydrophobic device 20, and a chemical analyzer 30; the test pipe section 10 has a horizontal pipe 111; one end of the hydrophobic device 20 is connected to the horizontal pipe 111 and is used to separate gaseous substances in the gas-liquid mixture in the horizontal pipe 111 without losing liquid cooling water 200a; the chemical analyzer 30 is connected to the horizontal pipe 111 and is used to measure and analyze the chemical composition of the substances in the horizontal pipe 111 in real time.

[0030] In this embodiment, the test pipe section 10 may include a main pipeline and branch pipelines, with the horizontal pipeline 111 being a section of the branch pipeline. Both ends of the test pipe section 10 may be connected to stainless steel pipelines to form a loop.

[0031] In this embodiment, the chemical analyzer 30 has two or more measurement channels. The measurement channels measure and provide real-time feedback at designated locations at both ends of the horizontal pipe 111. The measurement parameters of the chemical analyzer 30 include at least one of dissolved oxygen concentration, dissolved hydrogen concentration, and metal ion concentration. Specifically, measurements can be taken and real-time feedback can be provided at designated measurement locations one and two (located at both ends of the horizontal pipe 111, respectively) within the branch pipe. These two locations are determined based on the results of multiple operating condition tests. Tests on the downstream horizontal pipe revealed that "cracks are highly likely to occur at bends and the ends of the horizontal pipe 111." Furthermore, chemical composition measurements showed that the changes at these two measurement points were more significant and representative than at other locations, thus reflecting the changes in the chemical composition of this structure within the downstream horizontal pipe of the nuclear power plant.

[0032] To make the results of the experimental study more accurate, refer to Figure 2 In this embodiment, the experimental research system for the influence of non-condensable gases in the nuclear power plant pipeline may further include a gas-rich water system. The two ends of the test pipe section 10 are respectively the two ends of the stainless steel pipeline loop, and the gas-rich water system is connected to the stainless steel pipeline loop. The gas-rich water system may include a gas-rich water tank 41 for containing cooling water 200a, and an agitator 42 and a heater located within the gas-rich water tank 41. The top opening of the gas-rich water tank 41 is adapted to connect with the ambient atmosphere. The heater is used for constant temperature control of the cooling water 200a, and the agitator 42 is used to fully mix air with the cooling water 200a to form fully dissolved air cooling water 200a for later use. The gas-rich water system can provide a certain flow rate of fully dissolved air cooling water 200a to the stainless steel pipeline loop via a volumetric pump 43.

[0033] To ensure that the cooling water 200a in the main pipeline of test pipe section 10 reaches the target temperature and flow rate, and to collect measurement information of the measuring points, refer to Figure 2In this embodiment, the system may further include a pressure regulator 51, a cooler 52, an electric heater 53, a flow meter 54, a variable frequency pump 55, a rectifier 56, a filter 57, and temperature and pressure measuring instruments, all installed on the stainless steel pipeline circuit. This allows the cooling water 200a in the main pipeline of the test pipe section 10 to reach the target temperature and flow rate, and enables the collection of measurement information from the measuring points. In this embodiment, the variable frequency pump 55, pressure regulator 51, electric heater 53, and other equipment provide certain pressure, temperature, and flow conditions for the main pipeline of the test pipe section 10. The air-rich water system ensures that the cooling water 200a is fully dissolved in air and that the temperature boundary conditions are consistent under multiple operating conditions.

[0034] It is understood that this invention uses a hydrophobic device 20 to separate the non-condensable gas 200b from the gas-liquid mixture within the horizontal pipe 111 of the test section 10, thereby enabling the measurement of the amount of non-condensable gas 200b generated under different operating conditions. This invention employs a chemical analyzer 30 to achieve real-time measurement and analysis of the chemical composition of the substances within the horizontal pipe 111. Furthermore, the hydrophobic device 20 can be used to reverse the introduction of non-condensable gas 200b to quantitatively investigate its impact on the experimental research of the downflow horizontal pipe in nuclear power plants. This system provides a strong reference for exploring the mechanism of non-condensable gas 200b's influence on the downflow horizontal pipe of pressurized water reactor nuclear power plants, and is at a leading level both domestically and internationally.

[0035] It should be noted that measuring the amount of non-condensable gas 200b generated under a certain test condition can preliminarily determine the rationality of the boundary conditions (such as main pipeline pressure and temperature) set for that condition, and reduce the adverse effects of non-condensable gas 200b; the quantitative effect test of non-condensable gas 200b can further determine the effect of different volumes of non-condensable gas 200b on the test.

[0036] Reference Figures 2 to 4 In one embodiment, multiple drainage devices 20 may be provided, and these devices are arranged linearly along the length of the horizontal pipe 111. This system can perform tests to measure the generation of non-condensable gas 200b under different operating conditions and to study the quantitative impact of non-condensable gas 200b on the downstream horizontal pipe of a nuclear power plant.

[0037] In this embodiment, the hydrophobic device 20 may include a hydrophobic pipe 21, a hydrophobic membrane 22, a piston body 23, and a piston gas cylinder 24. One end of the hydrophobic pipe 21 is connected to the highest point of the horizontal pipe 111 to facilitate the efficient discharge of non-condensable gas 200b. The other end of the hydrophobic pipe 21 is connected to the piston gas cylinder 24. The piston body 23 is movably disposed within the piston gas cylinder 24. The hydrophobic membrane 22 is disposed within the hydrophobic pipe 21 and is used to separate the gas from the gas-liquid mixture without reducing the liquid component. In this way, not only is the gas separated from the gas-liquid mixture, but also the working fluid (including but not limited to non-condensable gas 200b, cooling water 200a, water vapor, etc.) is quantitatively injected into the horizontal pipe 111 of the branch pipe in the reverse direction.

[0038] This invention employs a horizontal pipeline 111 with multiple drainage devices 20, which can be used to conduct tests on the generation of non-condensable gas 200b under different operating conditions and to study the impact of quantitative non-condensable gas 200b on the downstream horizontal pipeline of nuclear power plants. It can provide a strong reference for setting the boundary conditions of operating conditions (such as main pipeline pressure and temperature), and also provide a strong reference for pipeline fatigue analysis research technology in the nuclear energy field.

[0039] To further improve the gas-liquid separation effect and adapt to different temperature and pressure conditions, in one embodiment, the hydrophobic membrane 22 can withstand a maximum back pressure of P1, which satisfies the following relationship: P1≥0.4MPa; The highest temperature that the hydrophobic membrane 22 can withstand is T1, which satisfies the following relationship: T1≥140℃.

[0040] In this embodiment, the shape of the hydrophobic membrane 22 can be adapted to the shape of the connection between the hydrophobic pipe 21 and the horizontal pipe 111, so as to fit against the inner wall of the downstream horizontal pipe 111 of the nuclear power plant, thereby reducing the impact on the fluid distribution inside the horizontal pipe 111. The hydrophobic membrane 22 includes, but is not limited to, alumina-based hydrophobic ceramic membranes, zirconia-based hydrophobic ceramic membranes, silicon carbide-based hydrophobic ceramic membranes, polytetrafluoroethylene membranes, polyvinylidene fluoride membranes, polyetheretherketone membranes, or metal sintered hydrophobic membranes 22, etc., and is not limited here.

[0041] Reference Figure 3 and Figure 4 In one embodiment, the back pressure of the piston cylinder 24 is ambient atmospheric pressure, making it suitable for horizontal placement with respect to the ground to reduce the influence of gravity on the piston body 23. The piston cylinder 24 is equipped with a graduation scale, with a measurement range of not less than 2000 ml and a minimum graduation of not more than 10 ml. Thus, the operator can directly read the amount of non-condensable gas 200b generated via the graduation scale. A needle valve can be installed on the condensate drain pipe 21, which is used to control the separation rate of non-condensable gas 200b by adjusting its opening, thereby further improving the efficiency and accuracy of experimental research.

[0042] Reference Figure 3 and Figure 4 In one embodiment, the hydrophobic device 20 may further include a drive mechanism 25, which is drivenly connected to the piston body 23 and is used to drive the piston body 23 to move in the opposite direction to quantitatively inject the working fluid into the horizontal pipe 111. The drive mechanism 25 may be a manually driven structure or an automatically driven structure driven by a motor or cylinder, etc., and is not limited here.

[0043] In this embodiment, when the piston cylinder 24 is filled with a working medium (including but not limited to non-condensable gas 200b, cooling water 200a, water vapor, etc.), the piston body 23 can be driven by the drive mechanism 25 to move and quantitatively inject the working medium into the horizontal pipe 111 of the branch pipe in the reverse direction. The driving pressure of the drive mechanism 25 is P2. To prevent damage to the hydrophobic membrane 22, the following relationship should be satisfied: |P2-P1|≤0.4MPa.

[0044] In a specific working condition, refer to Figure 2 and Figure 5 The measurement test of the generation of non-condensable gas 200b was conducted as follows: 1. Preparation stage: The rich air water system starts to run. The agitator 42 makes the cooling water 200a fully dissolve the air. The heater in the rich air water tank 41 heats the cooling water 200a to the target temperature of 25°C. The volumetric pump 43 fills the stainless steel circuit with the fully dissolved air cooling water 200a. 2. Turn on the variable frequency pump 55 and the electric heater 53. With the cooperation of the pressure regulator 51, adjust the cooling water 200a in the main pipeline to the target temperature, pressure and flow rate (reference pressure is 0.3MPa, 130℃, 400m). 3 / h); 3. Turn on the chemical analyzer 30 to measure the chemical parameters at the ends of the bend and horizontal pipe 111 in real time, such as dissolved oxygen concentration, dissolved hydrogen concentration, and metal ion concentration. 4. Open the needle valve between the condensate drain device 20 and the horizontal pipe 111, adjust it to an appropriate opening, observe the position of each piston body 23 until there is no obvious change, close the needle valve, and record the amount of non-condensable gas 200b collected by the condensate drain device 20 at different positions. 5. Maintain target temperature, pressure, and flow rate (reference pressure: 0.3 MPa, 130℃, 400 m³ / h). 3 / h) After a certain period of time (reference time is 2h), once the hot and cold fluids in the branch pipe section of the test section have fully developed, repeat step 4. 6. If it is necessary to determine the changes in chemical measurement parameters at the measuring points in the horizontal pipe 111 over a long period of time (such as 10h or 24h), the timing can be restarted, and then the parameter changes fed back by the chemical analyzer 30 can be observed. 7. After the test, the circuit is cooled and depressurized by cooler 52, and then the power is turned off and the cooling water 200a is drained.

[0045] Experimental Analysis and Summary: In the above process, if non-condensable gas 200b is collected at the beginning of the experiment (i.e., step 4), it indicates that the non-condensable gas 200b is due to the accumulation of the horizontal pipe section caused by the special structure of the downstream horizontal pipe 111 in the initial stage of the experiment. Subsequent experiments require venting treatment or structural modification of the horizontal pipe 111. After maintaining this for a certain period (reference time is 2 hours), once the main pipeline and branch pipelines have fully developed, it was found that non-condensable gas 200b was collected at different locations of the drainage devices 20. (Corresponding to the attached...) Figure 5 As shown in the schematic diagram of the distribution of different amounts of non-condensable gas 200b in the horizontal pipe 111, the non-condensable gas 200b covers one or more hydrophobic devices 20. The gas-liquid interface layer formed by excessive non-condensable gas 200b is very unstable, which not only affects the observation of phenomena such as turbulent infiltration and thermal stratification, but may even directly affect the experimental results. After the non-condensable gas 200b is released from the cooling water 200a, the dissolved oxygen in the cooling water 200a will be significantly reduced, which can be fed back in real time by the chemical analyzer 30. If it is necessary to observe the changes in chemical parameters in the cooling water 200a for a long time, the experiment needs to be continued for 10 hours and 24 hours. As time goes by, due to the mutual permeation of fluids between the main pipe and the branch pipes in the horizontal pipe 111, the corresponding dissolved oxygen concentration, metal ion or dissolved hydrogen concentration will increase, which can also be fed back in real time by the chemical analyzer 30.

[0046] In another example operating condition, the main reference is... Figure 2 The experiment was affected by different volumes of non-condensable gas 200b. The operation process is as follows: 1. Preparation stage: The rich air water system starts to run. The agitator 42 makes the cooling water 200a fully dissolve the air. The heater in the rich air water tank 41 heats the cooling water 200a to the target temperature of 25°C. The volumetric pump 43 fills the stainless steel circuit with the fully dissolved air cooling water 200a. 2. Turn on the variable frequency pump 55 and the electric heater 53. With the cooperation of the voltage regulator 51, adjust the cooling water 200a in the main pipeline to the target temperature, pressure and flow rate (reference pressure 0.4MPa, 120℃, 500m). 3 / h); 3. Turn on the chemical analyzer 30 to measure the dissolved oxygen concentration, dissolved hydrogen concentration, and metal ion concentration at the end of the bend and horizontal pipe 111 in real time; 4. Open the needle valve between the condensate drain device 20 and the horizontal pipe 111, adjust it to an appropriate opening degree, observe the position of each piston body 23 until there is no obvious change, then close the needle valve and release the collected non-condensable gas 200b. 5. Fill the piston cylinder 24 of the hydrophobic device 20 with the target volume of air, for example, fill the first to third hydrophobic devices 20 with 500ml, 400ml and 300ml respectively, turn on the drive mechanism 25, and inject the air into the horizontal pipe 111. 6. Observe the temperature change at the thermal stratification interface. Repeat steps 4 and 5 above to conduct multi-condition test operations (such as changing the volume and position of the air injected in step 5). After the test, cool the circuit and reduce the pressure through cooler 52.

[0047] Experimental Analysis and Summary: In the above process, the non-condensable gas 200b in the horizontal pipe 111 was discharged through step 4, and then the target volume of non-condensable gas 200b was injected using the piston gas cylinder 24 to explore the influence of different volumes of non-condensable gas 200b on the experiment, such as the influence of temperature fluctuation at the thermal boundary layer interface and the influence of dissolved oxygen content in the test section.

[0048] In summary, this invention enables the measurability of non-condensable gas 200b. The horizontal pipe 111 is equipped with multiple hydrophobic devices 20, which can measure the amount of non-condensable gas 200b collected at different positions of the horizontal pipe 111 in real time. This method can not only determine whether there is initial accumulation of non-condensable gas 200b, but also determine whether dissolved air in the cooling water 200a is released due to temperature rise, thereby providing a reference for the reasonable setting of test boundary conditions such as main pipeline temperature and pressure.

[0049] The experimental research system for the impact of non-condensable gases in nuclear power plant pipelines of the present invention supports the quantitative study of the impact of non-condensable gas 200b. The piston gas cylinder 24 of the condensate drain device 20 is equipped with a drive mechanism 25. When the cylinder is filled with gas, the drive mechanism 25 can be used to quantitatively inject gas into the condensate drain pipes 21 at different positions of the horizontal pipeline 111 of the branch pipeline, thereby conducting a quantitative study on the impact of non-condensable gas 200b on the downstream horizontal pipeline of the nuclear power plant.

[0050] The experimental research system for the impact of non-condensable gases in nuclear power plant pipelines of this invention supports water quality detection at key locations throughout the entire operation process. It is equipped with a chemical composition analysis system that can measure and provide real-time feedback on parameters such as dissolved oxygen concentration, dissolved hydrogen concentration, and metal ion concentration at designated locations within the branch pipeline. The dissolved oxygen concentration can be used to corroborate the amount of dissolved air released in the cooling water 200a. The dissolved hydrogen concentration and metal ion concentration can also be used to determine the corrosion status at key locations. Furthermore, the intensity of eddies can be determined by the changes in dissolved hydrogen concentration and metal ion concentration per unit time.

[0051] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A system for experimental research on the influence of non-condensable gases in nuclear power plant pipelines, characterized in that, The system includes: The test section has horizontal pipes; A hydrophobic device, one end of which is connected to the horizontal pipe, is used to separate gaseous substances from the gas-liquid mixture within the horizontal pipe without losing liquid cooling water; and A chemical analyzer, connected to the horizontal pipe, is used to measure and analyze the chemical composition of substances within the horizontal pipe in real time.

2. The experimental research system for the influence of non-condensable gases in nuclear power plant pipelines as described in claim 1, characterized in that, The hydrophobic device comprises multiple units arranged linearly. Each hydrophobic device includes a hydrophobic tube, a hydrophobic membrane, a piston body, and a piston cylinder. One end of the hydrophobic tube is connected to the highest point of the horizontal pipe, and the other end of the hydrophobic tube is connected to the piston cylinder. The piston body is movably disposed within the piston cylinder. The hydrophobic membrane is disposed within the hydrophobic tube and is used to separate the gas from the gas-liquid mixture without reducing the liquid component.

3. The experimental research system for the influence of non-condensable gases in nuclear power plant pipelines as described in claim 2, characterized in that, The maximum back pressure that the hydrophobic membrane can withstand is P1, which satisfies the following relationship: P1≥0.4MPa; and / or The highest temperature that the hydrophobic membrane can withstand is T1, which satisfies the following relationship: T1≥140℃。 4. The experimental research system for the influence of non-condensable gases in nuclear power plant pipelines as described in claim 2, characterized in that, The shape of the hydrophobic membrane is adapted to the shape of the connection between the hydrophobic tube and the horizontal pipe. The hydrophobic membrane is an alumina-based hydrophobic ceramic membrane, a zirconia-based hydrophobic ceramic membrane, a silicon carbide-based hydrophobic ceramic membrane, a polytetrafluoroethylene membrane, a polyvinylidene fluoride membrane, a polyether ether ketone membrane, or a metal sintered hydrophobic membrane.

5. The experimental research system for the influence of non-condensable gases in nuclear power plant pipelines as described in claim 2, characterized in that, The piston cylinder is positioned at ambient atmospheric pressure, making it suitable for horizontal placement relative to the ground; the piston cylinder is graduated, with a measurement range of not less than 2000 ml and a minimum graduation of not more than 10 ml; and / or The drain pipe is equipped with a needle valve, which is used to control the separation rate of non-condensable gases by adjusting the opening degree.

6. The experimental research system for the influence of non-condensable gases in nuclear power plant pipelines as described in claim 3, characterized in that, The hydrophobic device also includes a drive mechanism, which is drivenly connected to the piston body and is used to drive the piston body to move in the opposite direction to quantitatively inject working fluid into the horizontal pipe.

7. The experimental research system for the influence of non-condensable gases in nuclear power plant pipelines as described in claim 6, characterized in that, The driving pressure of the driving mechanism is P2, which satisfies the following relationship: |P2-P1|≤0.4MPa.

8. The experimental research system for the influence of non-condensable gases in nuclear power plant pipelines as described in any one of claims 1-7, characterized in that, The system also includes an air-rich water system, with the two ends of the test pipe section being the two ends of a stainless steel pipe loop, and the air-rich water system being connected to the stainless steel pipe loop; the air-rich water system includes an air-rich water tank for containing cooling water and an agitator and a heater located in the air-rich water tank, the air-rich water tank being adapted to be connected to the ambient atmosphere, the heater being used to maintain a constant temperature for the cooling water, and the agitator being used to fully mix the air with the cooling water to form cooling water with fully dissolved air.

9. The experimental research system for the influence of non-condensable gases in nuclear power plant pipelines as described in claim 8, characterized in that, The system also includes a voltage regulator, cooler, electric heater, flow meter, variable frequency pump, rectifier, filter, and temperature and pressure measuring instruments installed on the stainless steel pipeline circuit.

10. The experimental research system for the influence of non-condensable gases in nuclear power plant pipelines as described in any one of claims 1-7, characterized in that, The chemical analyzer has two or more measurement channels. The measurement channels measure and provide real-time feedback at designated positions at both ends of the horizontal pipe. The measurement parameters of the chemical analyzer include at least one of dissolved oxygen concentration, dissolved hydrogen concentration, and metal ion concentration.

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