Device for measuring pressure difference of strongly corrosive medium loop of primary loop of nuclear reactor

Abstract

The utility model discloses a nuclear reactor primary loop strong corrosive medium loop pressure difference measuring device which comprises a compressed gas cylinder, a gas guide pipe, a first branch pipe, a second branch pipe and a pressure guide pipe. Protective gas is arranged in the compressed gas cylinder, the compressed gas cylinder is communicated with the gas guide pipe, the first branch pipe and the second branch pipe are communicated with the gas guide pipe, and the tail ends of the first branch pipe and the second branch pipe are communicated with different positions of the strong corrosive medium loop; the first branch pipe is provided with a first valve, the second branch pipe is provided with a second valve, one end of the pressure guide pipe is communicated with the first branch pipe, the other end of the pressure guide pipe is communicated with the second branch pipe, and a differential pressure gauge is arranged on the pressure guide pipe. According to the utility model, the external gas passages at different sites of the strong corrosive medium loop form a protective passage, and the differential pressure gauges are connected between the external gas passages at different sites, so that when the external gas passages are filled with gas and reach pressure balance with the loop, the differential pressure value is read through the differential pressure gauges; the purpose of measuring the pressure difference between different measuring sites in a highly corrosive medium loop is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of nuclear energy engineering, in particular to a circuit differential pressure measuring device for a highly corrosive medium circuit in a primary circuit of a nuclear reactor. Background Art

[0002] Liquid metal has high thermal conductivity and is an excellent coolant, so it is widely used in the field of high heat flux heat exchange. For example, in the nuclear industry, liquid metal sodium, sodium-potassium alloy, lithium-lead alloy and lead-bismuth alloy are widely studied as alternative materials for the coolant of the first loop (reactor coolant system) of the fourth-generation nuclear reactor.

[0003] During the safe operation of the primary loop of a nuclear reactor, the pressure differential of the liquid metal is an important parameter to ensure the safe and stable operation of the entire loop. Therefore, the measurement of the pressure differential of the liquid metal loop of a nuclear reactor is an indispensable link. While obtaining the operating parameters of the primary loop of the nuclear reactor and optimizing the design of the primary loop of the reactor, it can also effectively monitor the safety and stability of the operation process and prevent possible safety problems. However, in the prior art, since liquid metal is highly corrosive and the operating temperature of the liquid metal loop is relatively high, it is impossible to directly measure it using a pressure sensor. Therefore, two sets of diaphragm sensors are usually used to measure the pressure differential of the liquid metal. However, the existing pressure differential measurement device with two sets of diaphragm sensors has a relatively complex structure, high manufacturing process requirements, and requires frequent replacement of sensor diaphragms, resulting in high cost of use.

[0004] In order to solve the above problems, the Chinese utility model patent with authorization announcement number CN102928151B discloses a liquid metal pressure measurement method and device, the device includes: a pressure gauge connected to a gas pipe; the gas pipe is connected to a pressure buffer pipe through a transfer elbow; the pressure buffer pipe is connected to a liquid metal pipeline through an elbow. The above technical solution can directly use conventional pressure sensors to measure the pressure of a highly corrosive liquid metal circuit, avoiding the measurement method of two sets of diaphragm sensors. However, this technical solution still has many technical defects, such as:

[0005] (1) It is impossible to measure the dynamic pressure value and pressure difference between two points in the liquid metal circuit;

[0006] (2) It is impossible to avoid metal impurities floating up and clogging the pressure-inducing pipeline, and the liquid metal is not easy to recover.

[0007] To this end, the present application aims to propose a novel nuclear reactor primary circuit highly corrosive medium circuit differential pressure measuring device, aiming to solve the above-mentioned problems. Utility Model Content

[0008] The main purpose of the utility model is to provide a nuclear reactor highly corrosive medium loop pressure difference measuring device, aiming to solve the technical problem that the nuclear reactor primary loop highly corrosive medium loop pressure measuring device in the prior art cannot simultaneously measure the pressure difference between multiple measurement points.

[0009] It should be noted that the highly corrosive medium described in this application includes not only liquid metal, but also other liquid media with strong corrosive properties such as liquid strong acid, liquid strong alkali, etc. The technical solution provided by the utility model is not only applicable to liquid metal medium environment, but also to other liquid media environments with strong corrosive properties such as liquid strong acid, liquid strong alkali, etc.

[0010] In order to achieve the above-mentioned purpose of the utility model, the utility model proposes a pressure difference measuring device for a highly corrosive medium circuit of a nuclear reactor primary circuit, comprising a compressed gas cylinder, an air pipe, a first branch pipe, a second branch pipe and a pressure pipe; a protective gas is arranged in the compressed gas cylinder and is connected to the air pipe, the first branch pipe and the second branch pipe are both connected to the air pipe, and the tail ends of the first branch pipe and the second branch pipe are respectively used to be connected to different positions of the highly corrosive medium circuit; the first branch pipe is provided with a first valve, the second branch pipe is provided with a second valve, one end of the pressure pipe is connected to the first branch pipe and is located between the first valve and the tail of the first branch pipe, the other end of the pressure pipe is connected to the second branch pipe and is located between the second valve and the tail of the second branch pipe, and a pressure differential gauge is provided on the pressure pipe.

[0011] Furthermore, a first branch pipe between the first valve and the pressure-conducting pipe and a second branch pipe between the second valve and the pressure-conducting pipe are both provided with a gas flow meter.

[0012] Furthermore, the tail of the first branch pipe and the tail of the second branch pipe are both provided with a connecting section, and the connecting section is arranged obliquely, wherein the connecting section is lower than one end of the tail and is connected to the highly corrosive medium circuit.

[0013] Furthermore, a heating device is sleeved on the pipe wall of the connecting section.

[0014] Furthermore, a heat-insulating material is provided on the outer side of the heating device.

[0015] Furthermore, a third valve is provided between the pressure conducting pipe between the first branch pipe and the pressure differential gauge, and a fourth valve is provided between the pressure conducting pipe between the second branch pipe and the pressure differential gauge.

[0016] Furthermore, a pressure gauge is provided between the first valve and / or the second valve and the highly corrosive medium circuit.

[0017] Furthermore, a fifth valve is provided between the pressure gauge and the first branch pipe and / or the second branch pipe.

[0018] Furthermore, the protective gas is argon or nitrogen.

[0019] Furthermore, a main valve is provided on the air guide pipe.

[0020] Beneficial effects:

[0021] Compared with the prior art, the utility model provides a pressure differential measuring device for a nuclear reactor primary-loop highly corrosive medium circuit, comprising a compressed gas cylinder, an air pipe, a first branch pipe, a second branch pipe and a pressure pipe; a protective gas is arranged in the compressed gas cylinder and is connected to the air pipe, the first branch pipe and the second branch pipe are both connected to the air pipe, and the tail ends of the first branch pipe and the second branch pipe are respectively used to be connected to different positions of the highly corrosive medium circuit; the first branch pipe is provided with a first valve, the second branch pipe is provided with a second valve, one end of the pressure pipe is connected to the first branch pipe and is located between the first valve and the tail of the first branch pipe, the other end of the pressure pipe is connected to the second branch pipe and is located between the second valve and the tail of the second branch pipe, and a pressure differential gauge is provided on the pressure pipe. The utility model connects external gas passages at different points of the nuclear reactor's highly corrosive medium loop, and a differential pressure gauge is connected between the external gas passages at different points. When the control gas is slowly introduced into the highly corrosive medium loop through the external gas loop at a very small flow rate, so that the gas and the highly corrosive medium approximately reach pressure equilibrium at the interface, the differential pressure value is read through the differential pressure gauge to achieve the purpose of simultaneously measuring the differential pressure between different measurement points in the nuclear reactor's highly corrosive medium loop. The flow of gas with a very small flow rate will not affect the pressure measurement accuracy, but the flowing gas can form an effective physical isolation between the pressure sensor and the highly corrosive medium, and the generally poor thermal conductivity of the gas also constitutes the temperature protection isolation of the pressure sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of a nuclear reactor highly corrosive medium circuit pressure difference measuring device according to an embodiment of the utility model;

[0023] Figure 2 This is another structural schematic diagram of a nuclear reactor highly corrosive medium circuit differential pressure measuring device according to an embodiment of the utility model.

[0024] in:

[0025] 1. Compressed gas cylinder; 2. Main valve; 3. Gas pipe; 4. First valve; 5. Second valve; 6. Gas flow meter; 7. First branch pipe; 8. Second branch pipe; 9. Differential pressure gauge; 10. Third valve; 11. Fourth valve; 12. Pressure pipe; 13. Pressure gauge; 14. Fifth valve; 15. Heating device; 16. Insulation material; 17. Liquid highly corrosive medium circuit.

[0026] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0027] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0029] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0030] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0031] In the current existing technology in the field of nuclear energy engineering, since liquid metal is highly corrosive and the operating temperature of the liquid metal circuit is high, it is impossible to use conventional pressure sensors to directly measure it. Therefore, two sets of diaphragm sensors are usually used to measure the pressure difference of the liquid metal. However, the existing pressure difference measurement device with two sets of diaphragm sensors has a relatively complex structure, high manufacturing process requirements, and requires frequent replacement of sensor diaphragms, resulting in high cost of use. With the continuous development of measurement technology for liquid metal circuits in this field, a technical solution has emerged to indirectly measure the pressure size of the measurement point through a gas medium between the liquid metal circuit measurement point and the actuator.

[0032] The embodiment of the utility model application provides a pressure difference measuring device for a highly corrosive medium loop in a primary loop of a nuclear reactor. Compared with the prior art, the measuring device has the advantages of simple structure, easy operation, and relatively low cost of use. In actual use, the measuring device can be used to simultaneously measure the pressure difference between different measuring points in the primary loop of a nuclear reactor. It can be used to solve the technical problem that the existing pressure measuring device for a liquid metal loop in a primary loop of a nuclear reactor cannot simultaneously measure the pressure difference between multiple measuring points.

[0033] The utility model application embodiment provides a nuclear reactor primary loop highly corrosive medium circuit differential pressure measuring device to solve the technical problem in the prior art that the nuclear reactor primary loop liquid metal circuit differential pressure measuring device cannot simultaneously measure the pressure differential between multiple measurement points, which will be explained in conjunction with the accompanying drawings below.

[0034] See also Figure 1 , Figure 2 , in this embodiment, Figure 1 , Figure 2 The cross-sectional diagram of the pressure difference measuring device of the nuclear reactor primary circuit highly corrosive medium circuit of the present application is shown. The pressure difference measuring device of the nuclear reactor primary circuit highly corrosive medium circuit provided by the present application comprises a compressed gas cylinder 1, an air pipe 3, a first branch pipe 7, a second branch pipe 8 and a pressure pipe 12; the compressed gas cylinder 1 is provided with a protective gas and is connected to the air pipe 3, the first branch pipe 7 and the second branch pipe 8 are both connected to the air pipe 3, and the tail ends of the first branch pipe 7 and the second branch pipe 8 are respectively connected to different positions of the highly corrosive medium circuit; the first branch pipe 7 is provided with a first valve 4, the second branch pipe 8 is provided with a second valve 5, one end of the pressure pipe 12 is connected to the first branch pipe 7 and is located between the first valve 4 and the tail of the first branch pipe, the other end of the pressure pipe 12 is connected to the second branch pipe 8 and is located between the second valve 5 and the tail of the second branch pipe, and a pressure differential gauge 9 is provided on the pressure pipe 12.

[0035] In this embodiment, the compressed gas cylinder 1 is connected to the air guide tube 3, and the air guide tube 3 is respectively connected to the first straight tube and the second straight tube to form a gas flow path. The compressed gas cylinder 1 is used to contain protective gas and can supply gas for the entire gas flow path. The tail ends of the first branch pipe 7 and the second branch pipe 8 are respectively connected to different positions of the highly corrosive medium circuit for measuring the pressure difference between the two positions. The first valve 4 is arranged on the first branch pipe 7, the second valve 5 is arranged on the second branch pipe 8, and the first valve 4 and the second valve 5 are respectively connected to the pressure guide pipe 12. The first valve 4 and the second valve 5 can control the gas in the pressure guide pipe 12 to flow to the first branch pipe 7 and / or the second branch pipe 8, and the gas can control the flow rate or flow rate during the flow of the branch pipes. A pressure differential gauge 9 is arranged on the pressure guide pipe between the first support pipe and the second support pipe to measure the pressure difference between the first branch pipe 7 and the second branch pipe 8.

[0036] It should be noted that the highly corrosive media described in this application include liquid metal, liquid strong acid, liquid strong alkali and other liquid media with strong corrosive properties. The nuclear reactor primary circuit highly corrosive medium circuit differential pressure measuring device provided by the utility model is not only applicable to liquid metal medium environment, but also to other liquid strong acid, liquid strong alkali and other highly corrosive liquid medium environments. The highly corrosive medium in the nuclear reactor primary circuit will be described below using liquid metal as an example.

[0037] In the above embodiment, the protective gas in the compressed gas cylinder 1 flows into the first branch pipe 7 and the second branch pipe 8 through the gas guide pipe 3. When the tail ends of the first branch pipe 7 and the second branch pipe 8 are respectively connected to different positions of the liquid metal circuit, the protective gas forms a pressure balance at these positions. When the pressure at a certain position of the liquid metal circuit changes, the other pressures in the first branch pipe 7 and the second branch pipe 8 will also change accordingly. By measuring the pressure difference between the first branch pipe 7 and the second branch pipe 8, the pressure difference between the two positions in the liquid metal circuit can be known. By reading the value in the pressure difference meter 9, the pressure difference between different positions in the liquid metal circuit can be obtained. In this scheme, the pressure changes at different positions in the liquid metal circuit of the first loop of the nuclear reactor are monitored in real time by monitoring the pressure difference meter 9 to ensure the safe operation of the reactor. At the same time, the protective gas is used as the measuring medium, and the protective gas will not react chemically with the liquid metal at high temperature.

[0038] Specifically, when the compressed gas cylinder 1 is connected to the gas duct 3, a threaded joint may be provided at the connection section of the compressed gas cylinder 1 and the gas duct 3, and the connection may be made by threading, or the compressed gas cylinder 1 and the gas duct 3 may be connected by plug joints. The protective gas may be argon, nitrogen or other chemically stable gases, which will not react chemically with liquid metal or other substances that may exist in other circuits, and can ensure that no error or contamination of the measuring device is introduced due to chemical reactions during the measurement process. In addition, the physical properties of argon and nitrogen, such as density and viscosity, change very little during the measurement process, and will not significantly affect the measurement results of the differential pressure gauge 9, thereby ensuring the accuracy and reliability of the measurement results.

[0039] In the above embodiment, the utility model connects external gas passages at different locations of the liquid metal loop of the nuclear reactor primary loop, and a pressure differential meter 9 is connected between the external gas passages at different locations. When the external gas passage passes the gas into the liquid metal loop at a very small flow rate and reaches pressure equilibrium with the liquid metal loop of the nuclear reactor primary loop, the pressure differential value is read by the pressure differential meter 9 to achieve the purpose of simultaneously measuring the pressure differential between different measurement locations in the liquid metal loop of the nuclear reactor primary loop. It can be understood that the measurement branches of the nuclear reactor primary loop highly corrosive medium loop pressure differential measuring device of the utility model can be set multiple to meet the more complex liquid metal loop pressure differential measurement requirements, and the flow of gas with a very small flow rate will not affect the pressure measurement accuracy. The flowing gas can form an effective physical isolation between the pressure sensor and the liquid metal medium. At the same time, the thermal conductivity of the gas is generally poor, which also constitutes the temperature protection isolation of the pressure sensor.

[0040] See also Figure 1 , Figure 2 In one embodiment, the first branch pipe 7 between the first valve 4 and the pressure-conducting pipe 12 and the second branch pipe 8 between the second valve 5 and the pressure-conducting pipe 12 are both provided with a gas flow meter 6 .

[0041] In this embodiment, a gas flow meter 6 is provided on the first branch pipe 7 between the first valve 4 and the pressure pipe 12, and the gas flow meter 6 is used to measure the flow rate of protective gas entering the first branch pipe 7 from the first valve 4. It can be understood that a gas flow meter 6 is also provided on the second branch pipe 8 between the second valve 5 and the pressure pipe 12, and is used to measure the flow rate of protective gas entering the second branch pipe 8 from the second valve 5. The two gas flow meters 6 are respectively installed at the connection between the first branch pipe 7 and the second branch pipe 8 and the pressure pipe 12, ensuring that the gas flow in the two branches can be monitored and controlled in real time and accurately.

[0042] In the above embodiment, since the pressure difference measurement needs to ensure that the gas flow in the two branches maintains an air pressure balance with the liquid metal circuit, so as to accurately reflect the pressure difference between different positions in the liquid metal circuit. Therefore, the gas flow meter 6 is used to cooperate with the first valve 4 and the second valve 5 to control the flow of the protective gas in the first branch 7 and the second branch 8. When the liquid metal level exceeds the measurement point, observe and record the change in the indication of the gas flow meter 6. When the indication remains at a value close to zero, control the opening and closing degree of the first valve 4 and the second valve 5, and then control the protective gas to slowly enter the liquid metal circuit at a very small flow rate, so that the air pressure of the protective gas at the measurement point reaches a balance with the pressure in the liquid metal circuit. At this time, the pressure difference between the measurement points in the liquid metal circuit is obtained through the reading of the differential pressure meter 9.

[0043] Please continue reading Figure 1 , Figure 2 In one embodiment, the tail of the first branch pipe and the tail of the second branch pipe are both provided with a connecting section, and the connecting section is inclined, wherein the connecting section is lower than one end of the tail and is connected to the highly corrosive medium circuit.

[0044] In the above embodiment, the inclined connection section is designed to guide the liquid metal to enter or leave the liquid metal circuit, reduce the flow resistance, and improve the flow efficiency. It should be noted that during the flow of liquid metal, it will be affected by multiple forces such as gravity, pressure, friction, etc., which will affect the effect of pressure measurement. Therefore, by designing an inclined connection section, the flow state of the liquid metal can be optimized. The inclined connection section can reduce the measurement error caused by unstable flow and enhance the stability of the system.

[0045] See also Figure 1 , Figure 2 In one embodiment, a heating device 15 is provided on the pipe wall of the connecting section, and the heating device 15 is used to heat the connecting section.

[0046] In this embodiment, the heating device 15 is used to heat the liquid metal in the connecting section. The heating device 15 is mounted on the connecting section to ensure that the heat energy of the heating device 15 can be effectively transferred to the connecting section, thereby heating the liquid metal in the connecting section. It should be noted that the liquid metal may become viscous or solidify in a low temperature environment, affecting its flow in the circuit. The heating device 15 heats the connecting section to ensure that the liquid metal in the connecting section maintains a sufficient temperature, thereby maintaining its good fluidity, thereby preventing the liquid metal from solidifying or forming a blockage in the connecting section due to the low temperature, which is beneficial to the normal operation of the measuring device and the reflux recovery of the liquid metal.

[0047] Specifically, the heating device 15 adopts electric heating, and the heating device 15 is provided with electric heating elements, including electric heating wires, electric heating films, etc. When the current passes through the electric heating elements, the electric energy is converted into heat energy and transferred to the pipe wall of the connecting section, and the pipe wall then transfers the heat energy to the liquid metal inside, so that the liquid metal can maintain a certain temperature. The heating device 15 is also provided with temperature sensors, PID controllers (Proportion-Integration-Different iat ion Controller: Proportion-Integration-Different iat ion Controller) and relays and other components. The temperature sensor is used to collect data and monitor the temperature state. The PID controller compares the collected temperature with the preset temperature value and generates an error signal. According to the error signal, the PID controller calculates a new temperature control amount through proportional, integral and differential operations to ensure that the temperature is maintained at the set state.

[0048] Please continue reading Figure 1 , Figure 2 In one embodiment, a heat-insulating material 16 is provided on the outside of the heating device 15, and the heat-insulating material 16 is used to maintain the temperature of the connecting section stable.

[0049] In this embodiment, the heat-insulating material 16 is used to reduce the heat dissipated from the heating device 15 to the external environment, thereby maintaining the temperature of the liquid metal in the connection section stable. When the heat is transferred from the heating device 15 to the outside, the heat-insulating material 16 can form a heat barrier to prevent the heat from being quickly dissipated to the external environment. In addition, by reducing the heat loss, the heat-insulating material 16 can reduce the operating energy consumption of the heating device 15, thereby reducing the operating cost of the entire system.

[0050] Please continue reading Figure 1 , Figure 2 In one embodiment, a third valve 10 is provided between the pressure guiding pipe 12 between the first branch pipe 7 and the pressure differential gauge 9 , and a fourth valve 11 is provided between the pressure guiding pipe 12 between the second branch pipe 8 and the pressure differential gauge 9 .

[0051] In this embodiment, the third valve 10 is installed on the pressure pipe 12 between the first branch pipe 7 and the differential pressure gauge 9, and is used to control or cut off the flow of fluid from the first branch pipe 7 to the differential pressure gauge 9. The fourth valve 11 is installed on the pressure pipe 12 between the second branch pipe 8 and the differential pressure gauge 9, and is used to control or cut off the flow of fluid from the second branch pipe 8 to the differential pressure gauge 9.

[0052] In the above embodiment, the third valve 10 and the fourth valve 11 play the role of isolation and protection in the system. When the differential pressure gauge 9 needs to be maintained, replaced or calibrated, the fluid in the pressure pipe 12 can be cut off by closing the corresponding valve, thereby ensuring safe operation and facilitating the maintenance of the differential pressure gauge 9.

[0053] See also Figure 1 , Figure 2 In one embodiment, a pressure gauge 13 is provided between the first valve 4 and / or the second valve 5 and the highly corrosive medium circuit.

[0054] In this embodiment, a pressure gauge 13 is provided between the first valve 4 and the liquid metal circuit, so that the pressure gauge 13 can measure and display the pressure at that point in the liquid metal circuit. It is understandable that the pressure gauge 13 is provided between the second valve 5 and the liquid metal circuit, and the pressure value at that point in the liquid metal circuit can be measured and displayed. It should be noted that, since a pressure differential gauge 9 is provided between the first branch and the second branch, only one setting can be selected between the first branch and the second branch to save costs, or it can be provided on both branches at the same time to ensure that the pressure data of the corresponding branch can be directly obtained.

[0055] See also Figure 1 , Figure 2 In one embodiment, a fifth valve 14 is provided between the pressure gauge 13 and the first branch pipe 7 and / or the second branch pipe 8 .

[0056] In the above embodiment, the fifth valve 14 is used to isolate the pressure gauge 13 from the branch pipe in the liquid metal circuit. When the pressure gauge 13 needs to be maintained, replaced or calibrated, the fluid connection between the pressure gauge 13 and the branch pipe can be cut off by closing the fifth valve 14, thereby ensuring operational safety. At the same time, in an emergency, such as system leakage or abnormal pressure, the fifth valve 14 can be quickly closed to prevent liquid metal from flowing into the pressure gauge 13 and protect the pressure gauge 13 from damage.

[0057] See also Figure 1 , Figure 2 In one embodiment, a main valve 2 is provided on the air duct 3.

[0058] In the present embodiment, the main valve 2 is used to control the flow of fluid in the air duct 3. By opening or closing the main valve 2, complete control of the fluid flow can be achieved, thereby ensuring the normal operation of the system or performing necessary maintenance. It can be understood that when the air duct 3 and its connected components need to be repaired, replaced or inspected, closing the main valve 2 can isolate the system from the air duct 3 to ensure the safety of the maintenance process.

[0059] The operation process of the nuclear reactor primary circuit highly corrosive medium circuit differential pressure measuring device of the utility model patent application takes liquid metal lead-bismuth eutectic alloy (hereinafter referred to as lead-bismuth alloy) as an example, and the measurement process is as follows:

[0060] When the primary loop of a nuclear reactor is in normal operation, the lead-bismuth alloy in the loop is driven by the main pump of the loop so that the lead-bismuth alloy can circulate in the nuclear reactor. When it is necessary to measure the pressure and pressure difference at two points in the liquid metal loop of a nuclear reactor, before the lead-bismuth alloy is filled into the liquid metal loop, the entire nuclear reactor liquid metal loop pressure difference measuring device is evacuated by a vacuum pump, and then the main valve 2, the first valve 4, the second valve 5, the third valve 10, the fourth valve 11, and the fifth valve 14 of the gas passage are opened to keep each branch pipe continuously ventilated into the liquid metal loop, and ensure that the argon or nitrogen in the compressed gas cylinder 1 fills the entire passage; at the same time, the heating device 15 is turned on, and before the lead-bismuth alloy is filled into the connecting section, the temperature of the connecting section is heated to a temperature higher than the melting point of the lead-bismuth alloy, and the heating temperature is continuously maintained. Then, the lead-bismuth alloy in the liquid metal loop is charged into the connecting section under the drive of the main pump. When the liquid level of the lead-bismuth alloy in the loop exceeds the measuring point, the change in the indication of the gas flowmeter 6 is observed and recorded. When the indication approaches zero, the opening and closing degree of the first valve 4 and the second valve 5 are controlled, and then the argon or nitrogen is controlled to slowly enter the liquid metal loop at a very small flow rate, so that the gas pressure of the argon or nitrogen at the connecting section reaches a state of equilibrium with the pressure of the lead-bismuth alloy. At this time, the pressure difference between the measuring points in the liquid metal loop is obtained by reading the differential pressure gauge 9, and the pressure value of the corresponding measuring point in the liquid metal loop can also be obtained by reading the pressure gauge 13.

[0061] In summary, the utility model provides a nuclear reactor primary-loop highly corrosive medium circuit differential pressure measuring device, comprising a compressed gas cylinder 1, an air pipe 3, a first branch pipe 7, a second branch pipe 8 and a pressure pipe 12; the compressed gas cylinder 1 is provided with a protective gas and is connected to the air pipe 3, the first branch pipe 7 and the second branch pipe 8 are both connected to the air pipe 3, and the tail ends of the first branch pipe 7 and the second branch pipe 8 are respectively connected to different positions of the liquid highly corrosive medium; the first branch pipe 7 is provided with a first valve 4, the second branch pipe 8 is provided with a second valve 5, one end of the pressure pipe 12 is connected to the first branch pipe 7 and is located between the first valve 4 and the tail of the first branch pipe, the other end of the pressure pipe 12 is connected to the second branch pipe 8 and is located between the second valve 5 and the tail of the second branch pipe, and a differential pressure gauge 9 is provided on the pressure pipe 12. The utility model connects external gas passages at different positions of a highly corrosive medium loop in a primary loop of a nuclear reactor, and a differential pressure gauge 9 is connected between the external gas passages at different positions. When the external gas passage is filled with gas and reaches pressure equilibrium with the highly corrosive medium loop in the primary loop of the nuclear reactor, the differential pressure value is read by the differential pressure gauge 9, so as to achieve the purpose of simultaneously measuring the differential pressure between different measuring positions in the highly corrosive medium loop in the primary loop of the nuclear reactor.

[0062] Compared with the prior art, the nuclear reactor primary circuit highly corrosive medium circuit differential pressure measuring device provided by the utility model also includes a connecting section, and the connecting section is provided with a heating device 15 and a heat-insulating material 16, which can prevent the highly corrosive medium from floating up and blocking the connecting section, and the highly corrosive medium is always in a heated state, which is conducive to recycling after the measurement is completed.

[0063] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A pressure difference measuring device for a nuclear reactor primary circuit with highly corrosive media, characterized in that: It includes a compressed gas cylinder, an air pipe, a first branch pipe, a second branch pipe and a pressure pipe; The compressed gas cylinder is provided with protective gas and is connected to the air duct, the first branch pipe and the second branch pipe are both connected to the air duct, and the tail ends of the first branch pipe and the second branch pipe are respectively used to be connected to different positions of the highly corrosive medium circuit; The first branch pipe is provided with a first valve, the second branch pipe is provided with a second valve, one end of the pressure conducting pipe is connected with the first branch pipe and is located between the first valve and the tail of the first branch pipe, the other end of the pressure conducting pipe is connected with the second branch pipe and is located between the second valve and the tail of the second branch pipe, and a differential pressure gauge is provided on the pressure conducting pipe.

2. The nuclear reactor primary circuit highly corrosive medium circuit differential pressure measuring device according to claim 1, characterized in that: A first branch pipe between the first valve and the pressure-conducting pipe and a second branch pipe between the second valve and the pressure-conducting pipe are both provided with a gas flow meter.

3. The nuclear reactor primary circuit highly corrosive medium circuit differential pressure measuring device according to claim 1, characterized in that: The tail of the first branch pipe and the tail of the second branch pipe are both provided with a connecting section, and the connecting section is arranged obliquely, wherein the connecting section is lower than one end of the tail and is connected with the highly corrosive medium circuit.

4. The nuclear reactor primary circuit highly corrosive medium circuit differential pressure measuring device according to claim 3, characterized in that: A heating device is sleeved on the pipe wall of the connecting section.

5. The nuclear reactor primary circuit highly corrosive medium circuit differential pressure measuring device according to claim 4, characterized in that: The outer side of the heating device is covered with heat-insulating material.

6. The nuclear reactor primary circuit highly corrosive medium circuit differential pressure measuring device according to claim 1, characterized in that: A third valve is provided between the pressure-conducting pipe between the first branch pipe and the pressure differential gauge, and a fourth valve is provided between the pressure-conducting pipe between the second branch pipe and the pressure differential gauge.

7. The nuclear reactor primary circuit highly corrosive medium circuit differential pressure measuring device according to claim 1, characterized in that: A pressure gauge is provided between the first valve and / or the second valve and the highly corrosive medium circuit.

8. The nuclear reactor primary circuit highly corrosive medium circuit differential pressure measuring device according to claim 7, characterized in that: A fifth valve is provided between the pressure gauge and the first branch pipe and / or the second branch pipe.

9. The nuclear reactor primary circuit highly corrosive medium circuit differential pressure measuring device according to any one of claims 1 to 8, characterized in that: The protective gas is argon or nitrogen.

10. The nuclear reactor primary circuit highly corrosive medium circuit differential pressure measuring device according to any one of claims 1 to 8, characterized in that: The air guide pipe is provided with a main valve.

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