A liquid level, pressure measurement and control system for a liquid lead-bismuth reactor and a method for installing the same
Patent Information
- Application Number
- CN202610791679.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-03
- Publication Date
- 2026-09-15
Smart Images
Figure CN122753501A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of liquid metal nuclear reactors, and more specifically, it relates to a liquid level and pressure measurement and control system for a prototype of a liquid lead-bismuth reactor and its installation method. Background Technology
[0002] Liquid lead-bismuth reactors are one of the important types of nuclear reactors. The reactor body is the core component that houses the reactor core and forms the flow path for the lead-bismuth coolant in the primary coolant loop system. During operation, liquid lead-bismuth reactors may experience unique thermal-hydraulic phenomena characteristic of liquid metal reactors, such as thermal stratification and thermal oscillation, solidification of the liquid lead-bismuth coolant, natural circulation, and surface sloshing. These phenomena directly affect the safe and stable operation of the reactor.
[0003] To verify the design safety of the liquid lead-bismuth reactor core, targeted thermo-hydraulic experiments are required. Accurate measurement of thermal parameters such as liquid level and pressure within the reactor core is crucial for experimental success. Currently, liquid level and pressure measurement technologies for conventional pressurized water reactors are relatively mature. However, the operating environment of a liquid lead-bismuth reactor is characterized by high temperature, strong radiation, and liquid metal corrosion. Furthermore, the reactor prototype has a unique dual-cavity structure consisting of a descending annular cavity and a core cavity, making existing measurement technologies inapplicable. The main technical limitations of existing technologies when applied to experiments on the liquid lead-bismuth reactor prototype are as follows: ① There is a lack of a dedicated liquid level and pressure measurement scheme adapted to the dual-cavity structure of the reactor prototype, making it impossible to accurately measure the parameters of the core chamber and the descending ring chamber simultaneously; ②The space of the descending ring cavity is small, making it difficult for the liquid level measuring instrument to achieve accurate positioning and fixed anchorage. Furthermore, the thermal displacement generated by the instrument and support structure under high temperature conditions cannot be effectively absorbed, which can easily lead to structural deformation or measurement errors. ③ The problem of sealing the penetration of a large number of instrument cables and gas pipelines within the reactor body is difficult to solve, and it cannot meet the pressure-bearing sealing requirements in the liquid lead-bismuth environment; ④ The lack of a systematic installation plan makes it easy for the measurement and control system to interfere with the prototype structure of the reactor body during installation, leading to installation failure or damage to components. Summary of the Invention
[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention provides a liquid level and pressure measurement and control system for a prototype liquid lead-bismuth reactor and its installation method, aiming to solve technical problems in the prior art such as incompatibility with the dual-chamber structure of the liquid lead-bismuth reactor prototype, difficulty in positioning and fixing measuring instruments, inability to absorb thermal displacement, low reliability of penetration seals, and easy interference during installation.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a liquid level and pressure measurement and control system for an experimental prototype of a liquid lead-bismuth reactor. The prototype includes a main container, a top cover, a core basket, a core grid plate, an electric heating assembly, and a dummy assembly. The main container is sealed to the top cover, the core basket is fixed inside the main container, and the core grid plate is connected to the bottom of the core basket. A descending annular cavity is formed between the core basket and the main container, and a core chamber is formed between the core basket, the core grid plate, and the top cover. The core chamber is divided into an annular region for loading the dummy assembly and a central region for loading the electric heating assembly. Both the descending annular cavity and the core chamber have a certain volume of gas space during operation. The liquid level and pressure measurement system includes: The liquid level measurement unit includes a core liquid level measuring liquid level gauge and at least one electrical contact liquid level gauge. The core liquid level measuring liquid level gauge is inserted into the annular region of the core chamber through the top cover and is used to measure the liquid level in the core chamber. The electrical contact liquid level gauge is disposed in the descending ring cavity and is used to measure the liquid level in the descending ring cavity. A gas space pressure measurement and control unit includes a core chamber filling and venting pipe, a descending annular cavity filling and venting pipe, and a pressure transmitter. The lower end of the core chamber filling and venting pipe is inserted into the gas space of the core chamber, and the lower end of the descending annular cavity filling and venting pipe is inserted into the gas space of the descending annular cavity. The upper ends of the core chamber filling and venting pipe and the descending annular cavity filling and venting pipe are respectively connected to the pressure transmitter. The liquid level gauge support and fixing structure includes a descending annular liquid level gauge integrated cylinder, which is fixedly connected to the outer wall of the reactor core basket, and the electrical contact liquid level gauge is installed in the descending annular liquid level gauge integrated cylinder.
[0006] Preferably, the core liquid level measuring level gauge is a guided wave radar liquid level gauge, which includes a liquid level gauge measuring end and a liquid level gauge fixing sealing flange. The core liquid level measuring level gauge is inserted into the core cavity through the top cover through hole of the top cover and is fixedly sealed to the top cover by the liquid level gauge fixing sealing flange.
[0007] Preferably, the descending annular level gauge integrated cylinder includes a level gauge integrated cylinder shell, a level gauge guide tube, and a level gauge fixing and sealing structure. Multiple level gauge guide tubes are fixedly connected to the level gauge integrated cylinder shell along the height direction, and the level gauge guide tubes are arranged inclined downwards to prevent wall adhesion during the discharge of liquid lead-bismuth. The electrical contact level gauge is inserted into the level gauge guide tube and fixed and sealed by the level gauge fixing and sealing structure. The integrated cylinder of the descending annular level gauge adopts a flat cylindrical structure that is thin at both ends and thick in the middle to fit the annular installation space of the descending annular cavity; the electrical contact level gauge consists of multiple gauges, which are arranged in a crisscross pattern on the left and right sides of the integrated cylinder of the descending annular level gauge.
[0008] Preferably, the level gauge support and fixing structure further includes: The upper fixed end of the level gauge integrated cylinder includes an upper fixed bracket and an upper fixed support. The upper fixed bracket is fixedly connected to the upper part of the level gauge integrated cylinder in the descending annular cavity, and the upper fixed support is fixedly connected to the outer wall of the core lifting basket. The upper fixed bracket and the upper fixed support are detachably connected by bolts.
[0009] The lower fixed end of the level gauge integrated cylinder includes a lower fixed bracket and a lower fixed support. The lower fixed bracket is fixedly connected to the lower part of the level gauge integrated cylinder in the descending annular cavity, and the lower fixed support is fixedly connected to the outer wall of the core lifting basket. The lower fixed bracket and the lower fixed support are detachably connected by bolts. The cable lead-out pipe of the descending annular level gauge is connected to the upper part of the integrated cylinder of the descending annular level gauge, and the cable of the electrical contact level gauge is led out to the outside of the stack body through the cable lead-out pipe of the descending annular level gauge.
[0010] Preferably, the lower fixed support of the level gauge integrated cylinder is provided with a capsule-shaped bolt hole to allow the lower fixed support of the level gauge integrated cylinder to slide relative to each other under axial temperature stress, thereby absorbing thermal displacement under high temperature environment.
[0011] Preferably, the gas space pressure measurement and control unit further includes a charging and discharging pipe tee sealing joint, wherein the upper end of the core chamber charging and discharging pipe and the upper end of the descending ring chamber charging and discharging pipe are respectively connected to the first interface of the charging and discharging pipe tee sealing joint, the second interface of the charging and discharging pipe tee sealing joint is connected to the pressure transmitter, and the third interface of the charging and discharging pipe tee sealing joint is used to connect to an external charging and discharging system.
[0012] Preferably, the system also includes a through-sealing structure, the through-sealing structure comprising: The first through-sealing structure and the second through-sealing structure are used to achieve through-sealing at the core basket through-hole at the upper part of the core basket through the first through-sealing structure, and through-sealing at the top cover through-hole of the top cover through the second through-sealing structure. The third through-sealing structure is used to achieve a through-sealing at the core basket through hole at the upper part of the core basket through the lower end of the descending annular cavity filling and exhaust pipe. The fourth through-sealing structure is used to achieve through-sealing at the top cover through hole of the top cover through the upper ends of the core chamber filling and exhaust pipe and the descending ring cavity filling and exhaust pipe.
[0013] Preferably, the system also includes an automatic liquid level control unit, which is electrically connected to the core liquid level measuring level gauge, the electrical contact level gauge, and the external charging / discharging system. The automatic liquid level control unit controls the charging / discharging pressure of the external charging / discharging system on the core chamber and the descending annular chamber based on the deviation between the measured liquid level value and the target set value, thereby achieving automatic liquid level control. Specifically: The automatic liquid level control unit incorporates a PID control algorithm. It collects the liquid level measurements from the core liquid level gauge and the electrical contact liquid level gauge in real time as feedback signals. The PID control adjusts the opening of the solenoid valve of the external charging and venting system, independently adjusting the charging and venting pressure of the core chamber charging and venting pipe to the core chamber and the charging and venting pressure of the descending ring chamber charging and venting pipe to the descending ring chamber. By changing the pressure difference in the gas space between the core chamber and the descending ring chamber, the liquid level of liquid lead-bismuth is adjusted.
[0014] Secondly, the present invention provides an installation method for a liquid level and pressure measurement and control system for a prototype of a liquid lead-bismuth reactor as described in the first aspect of the present invention, comprising the following steps: Open the top cover and remove the core basket and core grid plate; Assemble the core basket and core grid plate, and open through holes in the core basket at the preset positions; Install an electrical contact level gauge and its auxiliary structures; The assembled core basket and core grid are installed in the main container; Dumb components are installed in the annular region of the core chamber; An electric heating assembly is installed in the central area of the reactor core chamber; Install the venting and exhaust pipe for the descending annular cavity and its associated structures: Pass the lower end of the venting and exhaust pipe for the descending annular cavity through the through hole of the core lifting basket and seal and fix it through the third through sealing structure; Install the top cover and the through-sealing structure related to the top cover through hole: Pass the upper end of the cable lead-out pipe of the descending ring cavity level gauge and the upper end of the charging and venting pipe of the descending ring cavity through the corresponding top cover through hole, and seal and fix them respectively through the second through-sealing structure and the fourth through-sealing structure; Install the core chamber filling and venting pipes, filling and venting pipe tee sealing joints, and pressure transmitters; Install the core liquid level measuring level gauge: Insert the measuring end of the level gauge into the through hole of the top cover, and fix and seal it to the top cover through the level gauge fixing sealing flange to complete the installation of the entire system.
[0015] As a preferred embodiment, the aforementioned electrical contact level gauge and its auxiliary structure specifically comprises: Insert the electric contact level gauge into the level gauge guide tube of the level gauge integrated cylinder of the descending annular cavity, and seal it through the level gauge fixing and sealing structure. Welding and fixing the upper fixed bracket of the integrated cylinder of the level gauge, the lower fixed bracket of the integrated cylinder of the level gauge, and the descending annular cavity integrated cylinder of the level gauge; Welding and fixing the upper fixed support of the integrated cylinder of the level gauge, the lower fixed support of the integrated cylinder of the level gauge, and the core lifting basket; The upper fixing bracket of the integrated cylinder of the level gauge is connected to the upper fixing support of the integrated cylinder of the level gauge by bolts, and the lower fixing bracket of the integrated cylinder of the level gauge is connected to the lower fixing support of the integrated cylinder of the level gauge by bolts. Pass the lower end of the cable lead-out pipe of the descending annular level gauge through the through hole of the core basket, and weld the integrated cylinder of the descending annular level gauge to the cable lead-out pipe of the descending annular level gauge. The cable lead-out pipe of the descending annular cavity level gauge passing through the through hole of the core basket is sealed and fixed by the first through-sealing structure. The installation of the core chamber filling and venting pipe, the filling and venting pipe tee sealing joint, and the pressure transmitter specifically refers to: The lower end of the core chamber filling and venting pipe passes through the through hole in the top cover and is sealed and fixed by the fourth through sealing structure. Connect the upper ends of the core chamber filling and exhaust pipe and the descending ring cavity filling and exhaust pipe to the first interface of the filling and exhaust pipe tee sealing joint, respectively. Connect the pressure transmitter to the second port of the tee seal joint for the charging and discharging pipe, and connect the external charging and discharging system pipeline to the third port of the tee seal joint for the charging and discharging pipe.
[0016] The present invention has the following advantages due to the adoption of the above technical solutions: 1. This invention provides a solution for measuring and controlling the liquid level and pressure of a liquid lead-bismuth reactor prototype with a dual-chamber structure. It can simultaneously and accurately measure the liquid level and pressure parameters of the core chamber and the descending ring chamber, meet the parameter acquisition requirements of thermal-hydraulic experiments, and provide reliable data support for reactor design verification.
[0017] 2. This invention achieves precise positioning and reliable fixation of the electrical contact level gauge within the narrow descending annular cavity by designing a dedicated integrated cylinder and upper and lower fixed end structures for the descending annular level gauge. At the same time, by opening capsule-shaped bolt holes in the lower fixed support, it effectively absorbs the structural thermal displacement under high-temperature conditions, avoids structural deformation or measurement errors caused by thermal stress, and improves the operational reliability of the system.
[0018] 3. By setting up a multi-stage through-sealing structure, this invention solves the problem of through-sealing of a large number of instrument cables and gas pipelines in the reactor body, and can adapt to the working environment of liquid lead bismuth with high temperature, pressure and strong corrosion.
[0019] 4. The automatic liquid level control scheme designed in this invention is based on the principle of independent adjustment of dual-chamber pressure. It realizes stable automatic control of the liquid level of the reactor body through PID control algorithm, which can maintain the required flow head during the experiment and ensure the stable operation of the experiment.
[0020] 5. The systematic installation scheme provided by this invention, following the installation sequence from inside to outside and from bottom to top, effectively avoids interference problems between the measurement and control system and the reactor prototype structure during installation, ensuring that the measurement system is successfully installed inside the reactor prototype, and reducing installation difficulty and risk. Attached Figure Description
[0021] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the prototype of a liquid lead-bismuth reactor. Figure 2 This is a cross-sectional view of the internal structure of a prototype liquid lead-bismuth reactor. Figure 3 This is a schematic diagram of the liquid level measurement unit; Figure 4 This is a schematic diagram of the liquid level gauge used for measuring the liquid level in the reactor core. Figure 5 This is a schematic diagram of the integrated cylinder of the descending annular level gauge; Figure 6 A schematic diagram of the upper fixed end of the integrated cylinder of the level gauge; Figure 7 A schematic diagram of the structure of the lower fixed end of the integrated cylinder of the level gauge; Figure 8 This is a schematic diagram of the structure of the air space pressure measurement and control unit.
[0022] The attached figures are labeled as follows: 1. Main vessel; 2. Top cover; 2-1. Annular area of top cover; 2-2. Central area of top cover; 2-3. Through hole of top cover; 3. Core basket; 3-1. Through hole of core basket; 4. Core grid plate; 5. Electric heating assembly; 6. Dumb assembly; 7. Drop ring cavity; 8. Core chamber; 8-1. Annular area of core chamber; 8-2. Central area of core chamber; 9. Core liquid level measuring level gauge; 9-1. Measuring end of level gauge; 9-2. Fixed sealing flange of level gauge; 10. Electrical contact level gauge; 11. Integrated cylinder of drop ring cavity level gauge; 11-1. Level gauge guide tube; 11-2. Fixed sealing structure of level gauge; 11-3. Integrated level gauge 12. Upper fixed end of the integrated cylinder of the level gauge; 12-1. Upper fixed bracket of the integrated cylinder of the level gauge; 12-2. Upper fixed support of the integrated cylinder of the level gauge; 13. Lower fixed end of the integrated cylinder of the level gauge; 13-1. Lower fixed bracket of the integrated cylinder of the level gauge; 13-2. Lower fixed support of the integrated cylinder of the level gauge; 14. Cable lead-out pipe of the level gauge in the descending annular cavity; 15. First through-sealing structure; 16. Second through-sealing structure; 17. Core chamber filling and venting pipe; 18. Downward annular cavity filling and venting pipe; 19. Third through-sealing structure; 20. Fourth through-sealing structure; 21. Three-way sealing joint of the filling and venting pipe; 22. Pressure transmitter. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.
[0024] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.
[0026] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0028] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0029] This invention provides a liquid level and pressure measurement and control system and its installation method for a liquid lead-bismuth reactor prototype. The system includes a liquid level measurement unit and a gas space pressure measurement and control unit. A dedicated descending annular cavity level gauge integrated cylinder enables precise positioning and fixation of the electrical contact level gauge within the confined descending annular cavity. Automatic liquid level adjustment is achieved through independent dual-cavity filling and venting control. The installation method follows a step-by-step installation sequence from the inside out, avoiding installation interference. This invention solves the technical challenges of liquid level and pressure measurement and control in liquid lead-bismuth reactor prototype experiments. It offers advantages such as high measurement accuracy, good sealing performance, strong operational reliability, and convenient installation. It provides a reliable parameter measurement and control method for liquid lead-bismuth reactor thermal-hydraulic experiments and is suitable for use in liquid lead-bismuth reactor prototype experiments with a dual-cavity structure of descending annular cavity and core chamber, demonstrating significant engineering application value.
[0030] The following is a detailed description, with reference to the accompanying drawings, of the liquid level and pressure measurement and control system for the prototype of the liquid lead-bismuth reactor provided in this invention, as well as its installation method.
[0031] Example 1 The liquid level and pressure measurement and control system for the liquid lead-bismuth reactor prototype provided in this embodiment is adapted to the following reactor prototype structure: Figure 1 and Figure 2 As shown, the reactor includes a main container 1, a top cover 2, a core basket 3, a core grid plate 4, an electric heating assembly 5, and a dumb assembly 6. The main container 1 is a vertical cylindrical structure, sealed to the top cover 2 via a top flange. The core basket 3 is fixed inside the main container 1 by supporting shoulders, and the core grid plate 4 is bolted to the bottom of the core basket 3. The annular gap between the outer wall of the core basket 3 and the inner wall of the main container 1 forms a descending annular cavity 7. The internal space of the core basket 3, together with the core grid plate 4 and the top cover 2, constitutes the core chamber 8. Both the descending annular cavity 7 and the core chamber 8 have a certain volume of gas space during operation. The top cover 2 is divided into an outer annular region 2-1 and a central removable region 2-2. Both regions have several through holes 2-3 that communicate with the core chamber 8. The core chamber 8 is divided into an outer annular region 8-1 and an inner central region 8-2. The annular region 8-1 houses several duct components 6, which axially correspond to the top cover annular region 2-1, simulating the flow channel structure of an actual reactor core. The central region 8-2 houses several electric heating components 5, which axially correspond to the top cover central region 2-2, simulating core heat release and flow channel structure.
[0032] Please see Figure 3The liquid level and pressure measurement and control system of this embodiment includes a liquid level measurement unit and a gas space pressure measurement and control unit. The liquid level measurement unit includes a core liquid level gauge 9 and an electrical contact liquid level gauge 10. The core liquid level gauge 9 is inserted through the top cover 2 into the annular region 8-1 of the core chamber 8 to measure the overall liquid level within the core chamber 8. Several electrical contact liquid level gauges 10 are disposed within the descending annular cavity 7 to measure the overall liquid level within the descending annular cavity 7.
[0033] Please see Figure 8 The gas space pressure measurement and control unit includes a core chamber filling and exhaust pipe 17, a descending annular cavity filling and exhaust pipe 18, a filling and exhaust pipe tee sealing joint 21, and a pressure transmitter 22. The lower end of the core chamber filling and exhaust pipe 17 is inserted into the gas space region of the core chamber 8, and the lower end of the descending annular cavity filling and exhaust pipe 18 is inserted into the gas space region of the descending annular cavity 7. The upper ends of the core chamber filling and exhaust pipe 17 and the descending annular cavity filling and exhaust pipe 18 are respectively connected to the first interface of the filling and exhaust pipe tee sealing joint 21. The other two interfaces of the filling and exhaust pipe tee sealing joint 21 are respectively connected to the pressure transmitter 22 and the external filling and exhaust system pipeline, so as to realize the pressure measurement and control of the gas space in the core chamber 8 and the descending annular cavity 7.
[0034] In the above embodiments, preferably, please refer to Figure 4 The core liquid level measuring level gauge 9 can be a guided wave radar level gauge, including a level gauge measuring end 9-1 and a level gauge fixing sealing flange 9-2. The core liquid level measuring level gauge 9 is inserted into the annular region 8-1 of the core chamber 8 through the top cover through hole 2-3 in the top cover central region 2-2 and fixed and sealed with it through the level gauge fixing sealing flange 9-2.
[0035] In the above embodiments, preferably, the liquid level and pressure measurement and control system further includes a liquid level gauge support and fixing structure, which includes: ①The integrated cylinder 11 of the descending annular level gauge (please refer to...) Figure 5The system includes a level gauge guide tube 11-1, a level gauge fixing and sealing structure 11-2, and a level gauge integrated cylinder shell 11-3. The level gauge integrated cylinder shell 11-3 is fixedly connected to the outside of the core lifting basket 3. Multiple level gauge guide tubes 11-1 are fixedly connected to the level gauge integrated cylinder shell 11-3 along the height direction. Multiple electrical contact level gauges 10 are inserted into their respective level gauge guide tubes 11-1 and fixed and sealed by the level gauge fixing and sealing structure 11-2. Furthermore, the level gauge guide tubes 11-1 are arranged at an angle downward to ensure that no wall adhesion occurs when liquid lead-bismuth is emptied. The level gauge integrated cylinder 11 of the descending annular cavity adopts a flat cylindrical structure that is thin at both ends and thick in the middle to fit the annular installation space of the descending annular cavity 7. The electrical contact level gauges 10 are arranged crosswise on the left and right sides of the level gauge integrated cylinder 11 of the descending annular cavity to ensure that the electrical contact level gauges 10 achieve sufficient measurement accuracy in a limited space.
[0036] ② Fixed end 12 of the upper part of the level gauge integrated cylinder (see also) Figure 6 The system includes an upper fixing bracket 12-1 and an upper fixing support 12-2 for the integrated cylinder of the level gauge. The upper fixing bracket 12-1 is connected to the upper part of the integrated cylinder of the level gauge in the descending annular cavity by welding. The upper fixing support 12-2 is connected to the corresponding position of the outer wall of the core basket 3 by welding. The upper fixing bracket 12-1 and the upper fixing support 12-2 are detachably connected by bolts.
[0037] ③ Lower fixed end 13 of the level gauge integrated cylinder (see also) Figure 7 The system includes a lower fixing bracket 13-1 and a lower fixing support 13-2 for the integrated level gauge cylinder. The lower fixing bracket 13-1 is welded to the lower part of the integrated level gauge cylinder 11 in the descending annular cavity. The lower fixing support 13-2 is welded to the corresponding position on the outer wall of the core basket 3. The lower fixing bracket 13-1 and the lower fixing support 13-2 are detachably connected by bolts. Furthermore, the lower fixing support 13-2 has capsule-shaped bolt holes, allowing the lower fixing bracket 13-1 to slide under axial temperature stress after bolt connection, effectively absorbing the thermal displacement generated by the structure under high temperature environment.
[0038] ④ Lowering ring level gauge cable lead-out pipe 14 (see also) Figure 3The cable lead-out pipe 14 of the descending annular level gauge is connected to the upper part of the integrated cylinder 11 of the descending annular level gauge by welding. The cable lead-out pipe 14 of the descending annular level gauge first passes through and seals the core basket through hole 3-1 at the upper part of the core basket 3 through the first through sealing structure 15, and then extends upward through the second through sealing structure 16 to pass through and seal the top cover through hole 2-3 in the top cover annular area 2-1. All cables of the electrical contact level gauge 10 are led out from the descending annular level gauge cable lead-out pipe 14 to the signal acquisition system outside the reactor body.
[0039] In the above embodiments, preferably, the lower end of the descending annular cavity filling and exhaust pipe 18 is sealed through the core basket through hole 3-1 at the upper part of the core basket 3 via the third through sealing structure 19. The upper ends of the core chamber filling and exhaust pipe 17 and the descending annular cavity filling and exhaust pipe 18 are sealed through the top cover through hole 2-3 in the top cover central region 2-2 via the fourth through sealing structure 20.
[0040] In the above embodiments, preferably, an automatic liquid level control unit (not shown in the figure) is also included. Its control logic is as follows: First, the target liquid level values of the core liquid level measuring liquid level gauge 9 and the electric contact liquid level gauge 10 are set according to the experimental operation requirements; second, the measured values of the core liquid level measuring liquid level gauge 9 and the electric contact liquid level gauge 10 are collected in real time as feedback signals; then, the opening degree of the solenoid valve of the external charging and venting system is controlled by the PID adjustment algorithm, and the charging and venting pressure of the core chamber charging and venting pipe 17 to the core chamber 8 and the charging and venting pressure of the descending ring chamber charging and venting pipe 18 to the descending ring chamber 7 are adjusted respectively. By changing the pressure difference of the gas space in the two chambers, the liquid level height of liquid lead-bismuth is adjusted so that the liquid level measurement value approaches the target set value, thereby realizing automatic control of the liquid level.
[0041] Example 2 Based on the liquid level and pressure measurement system for the prototype of the liquid lead-bismuth reactor provided in Embodiment 1 above, this embodiment also provides an installation method for the above-mentioned liquid level and pressure measurement system, the specific steps of which are as follows: S1. Open the top cover 2 and remove the core basket 3 and core grid plate 4; S2. Assemble the core basket 3 and the core grid plate 4, and open the core basket through hole 3-1 at the preset position of the core basket 3; S3. Install the electrical contact level gauge 10 and its auxiliary structures: S3-1. Insert the electric contact level gauge 10 into the level gauge guide tube 11-1 of the level gauge integrated cylinder 11 of the descending annular cavity level gauge, and seal and fix it through the level gauge fixing and sealing structure 11-2. S3-2. Weld and fix the upper fixing bracket 12-1 of the integrated cylinder of the liquid level gauge, the lower fixing bracket 13-1 of the integrated cylinder of the liquid level gauge, and the liquid level gauge integrated cylinder 11 of the descending annular cavity; S3-3. Weld and fix the upper fixed support 12-2 of the integrated cylinder of the level gauge, the lower fixed support 13-2 of the integrated cylinder of the level gauge, and the core lifting basket 3; S3-4. Connect the upper fixing bracket 12-1 of the level gauge integrated cylinder to the upper fixing support 12-2 of the level gauge integrated cylinder, and the lower fixing bracket 13-1 of the level gauge integrated cylinder to the lower fixing support 13-2 of the level gauge integrated cylinder by bolts. S3-5. Pass the lower end of the descending annular level gauge cable lead-out pipe 14 through the core basket through hole 3-1, and weld the descending annular level gauge integrated cylinder 11 and the descending annular level gauge cable lead-out pipe 14 together. S3-6. The cable lead-out pipe 14 of the descending annular cavity liquid level gauge passing through the core basket through hole 3-1 is sealed and fixed by the first through sealing structure 15; S4. Install the assembled core basket 3 and core grid plate 4 in the main container 1; S5. Install dumb assembly 6 in the annular region 8-1 of the core chamber; S6. Install electric heating assembly 5 in the central region 8-2 of the core chamber; S7. Install the descending annular cavity filling and venting pipe 18 and its auxiliary structures: Pass the lower end of the descending annular cavity filling and venting pipe 18 through the core lifting basket through hole 3-1, and seal and fix it through the third through sealing structure 19; S8. Install the top cover 2 and the related through sealing structure of the top cover through hole 2-3: Pass the upper end of the descending ring cavity level gauge cable lead-out pipe 14 and the upper end of the descending ring cavity inflation and deflation pipe 18 through the corresponding top cover through hole 2-3 respectively, and seal and fix them through the second through sealing structure 16 and the fourth through sealing structure 20 respectively. S9. Install the core chamber filling and venting pipe 17, the filling and venting pipe tee sealing joint 21, and the pressure transmitter 22: S9-1. Pass the lower end of the core chamber filling and venting pipe 17 through the top cover through hole 2-3 and seal it with the fourth through sealing structure 20; S9-2. Connect the upper ends of the core chamber filling and venting pipe 17 and the descending annular cavity filling and venting pipe 18 to the first interface of the filling and venting pipe tee sealing joint 21, respectively. S9-3. Connect the pressure transmitter 22 to the second port of the charging / discharging pipe tee sealing joint 21, and connect the external charging / discharging system pipeline to the third port of the charging / discharging pipe tee sealing joint 21; S10. Install the core liquid level measuring level gauge 9: Insert the measuring end 9-1 of the level gauge into the through hole 2-3 of the top cover, and fix and seal it with the top cover 2 through the level gauge fixing and sealing flange 9-2 to complete the installation of the entire system.
[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A liquid level, pressure measurement and control system for a liquid lead bismuth reactor core mockup experiment, characterized in that, The prototype reactor includes a main container, a top cover, a core basket, a core grid plate, an electric heating assembly, and a dumb assembly. The main container is sealed to the top cover, the core basket is fixed inside the main container, and the core grid plate is connected to the bottom of the core basket. A descending annular cavity is formed between the core basket and the main container, and a core chamber is formed between the core basket, the core grid plate, and the top cover. The core chamber is divided into an annular region for loading dumb assemblies and a central region for loading electric heating assemblies. Both the descending annular cavity and the core chamber have a certain volume of gas space during operation. The liquid level and pressure measurement system includes: The liquid level measurement unit includes a core liquid level measuring liquid level gauge and at least one electrical contact liquid level gauge. The core liquid level measuring liquid level gauge is inserted into the annular region of the core chamber through the top cover and is used to measure the liquid level in the core chamber. The electrical contact liquid level gauge is disposed in the descending ring cavity and is used to measure the liquid level in the descending ring cavity. A gas space pressure measurement and control unit includes a core chamber filling and venting pipe, a descending annular cavity filling and venting pipe, and a pressure transmitter. The lower end of the core chamber filling and venting pipe is inserted into the gas space of the core chamber, and the lower end of the descending annular cavity filling and venting pipe is inserted into the gas space of the descending annular cavity. The upper ends of the core chamber filling and venting pipe and the descending annular cavity filling and venting pipe are respectively connected to the pressure transmitter. The liquid level gauge support and fixing structure includes a descending annular liquid level gauge integrated cylinder, which is fixedly connected to the outer wall of the reactor core basket, and the electrical contact liquid level gauge is installed in the descending annular liquid level gauge integrated cylinder.
2. The liquid level and pressure measurement and control system for the prototype of the liquid lead-bismuth reactor according to claim 1, characterized in that, The core liquid level measuring level gauge is a guided wave radar liquid level gauge, which includes a liquid level gauge measuring end and a liquid level gauge fixing sealing flange. The core liquid level measuring level gauge is inserted into the core cavity through the top cover through hole of the top cover and is fixedly sealed to the top cover by the liquid level gauge fixing sealing flange.
3. The liquid level and pressure measurement and control system for the prototype of the liquid lead-bismuth reactor according to claim 1, characterized in that, The descending annular level gauge integrated cylinder includes a level gauge integrated cylinder shell, a level gauge guide tube, and a level gauge fixing and sealing structure. Multiple level gauge guide tubes are fixedly connected to the level gauge integrated cylinder shell along the height direction, and the level gauge guide tubes are arranged inclined downwards to prevent wall adhesion when liquid lead bismuth is discharged. The electric contact level gauge is inserted into the level gauge guide tube and fixed and sealed by the level gauge fixing and sealing structure. The integrated cylinder of the descending annular level gauge adopts a flat cylindrical structure that is thin at both ends and thick in the middle to fit the annular installation space of the descending annular cavity; the electrical contact level gauge consists of multiple gauges, which are arranged in a crisscross pattern on the left and right sides of the integrated cylinder of the descending annular level gauge.
4. The liquid level and pressure measurement and control system for the prototype of the liquid lead-bismuth reactor according to claim 3, characterized in that, The level gauge support and fixing structure also includes: The upper fixed end of the level gauge integrated cylinder includes an upper fixed bracket and an upper fixed support. The upper fixed bracket is fixedly connected to the upper part of the descending annular cavity level gauge integrated cylinder, and the upper fixed support is fixedly connected to the outer wall of the core lifting basket. The upper fixed bracket and the upper fixed support are detachably connected by bolts. The lower fixed end of the level gauge integrated cylinder includes a lower fixed bracket and a lower fixed support. The lower fixed bracket is fixedly connected to the lower part of the level gauge integrated cylinder in the descending annular cavity, and the lower fixed support is fixedly connected to the outer wall of the core lifting basket. The lower fixed bracket and the lower fixed support are detachably connected by bolts. The cable lead-out pipe of the descending annular level gauge is connected to the upper part of the integrated cylinder of the descending annular level gauge, and the cable of the electrical contact level gauge is led out to the outside of the stack body through the cable lead-out pipe of the descending annular level gauge.
5. The liquid level and pressure measurement and control system for the prototype of the liquid lead-bismuth reactor according to claim 4, characterized in that, The lower fixed support of the liquid level gauge integrated cylinder is provided with a capsule-shaped bolt hole to allow the lower fixed support of the liquid level gauge integrated cylinder to slide relative to each other under axial temperature stress, thereby absorbing thermal displacement under high temperature environment.
6. The liquid level and pressure measurement and control system for the prototype test of the liquid lead-bismuth reactor according to claim 1, characterized in that, The gas space pressure measurement and control unit also includes a charging and venting pipe tee sealing joint. The upper end of the core chamber charging and venting pipe and the upper end of the descending ring chamber charging and venting pipe are respectively connected to the first interface of the charging and venting pipe tee sealing joint. The second interface of the charging and venting pipe tee sealing joint is connected to the pressure transmitter. The third interface of the charging and venting pipe tee sealing joint is used to connect to an external charging and venting system.
7. The liquid level and pressure measurement and control system for the prototype of the liquid lead-bismuth reactor according to claim 4, characterized in that, It also includes a through-sealing structure, the through-sealing structure comprising: The first through-sealing structure and the second through-sealing structure are used to achieve through-sealing at the core basket through-hole at the upper part of the core basket through the first through-sealing structure, and through-sealing at the top cover through-hole of the top cover through the second through-sealing structure. The third through-sealing structure is used to achieve a through-sealing at the core basket through hole at the upper part of the core basket through the lower end of the descending annular cavity filling and exhaust pipe. The fourth through-sealing structure is used to achieve through-sealing at the top cover through hole of the top cover through the upper ends of the core chamber filling and exhaust pipe and the descending ring cavity filling and exhaust pipe.
8. The liquid level and pressure measurement and control system for the prototype of the liquid lead-bismuth reactor according to claim 7, characterized in that, It also includes an automatic liquid level control unit, which is electrically connected to the core liquid level measuring level gauge, the electrical contact level gauge, and the external charging and venting system. The automatic liquid level control unit controls the charging and venting pressure of the external charging and venting system on the core chamber and the descending annulus chamber based on the deviation between the measured liquid level value and the target set value, thereby achieving automatic liquid level control. Specifically: The automatic liquid level control unit incorporates a PID control algorithm. It collects the liquid level measurements from the core liquid level gauge and the electrical contact liquid level gauge in real time as feedback signals. The PID control adjusts the opening of the solenoid valve of the external charging and venting system, independently adjusting the charging and venting pressure of the core chamber charging and venting pipe to the core chamber and the charging and venting pressure of the descending ring chamber charging and venting pipe to the descending ring chamber. By changing the pressure difference in the gas space between the core chamber and the descending ring chamber, the liquid level of liquid lead-bismuth is adjusted.
9. A method for installing a liquid level and pressure measurement and control system for a prototype of a liquid lead-bismuth reactor as described in claim 7 or 8, characterized in that, Includes the following steps: Open the top cover and remove the core basket and core grid plate; Assemble the core basket and core grid plate, and open through holes in the core basket at the preset positions; Install an electric contact level gauge and its auxiliary structures; The assembled core basket and core grid are installed in the main container; Dumb components are installed in the annular region of the core chamber; An electric heating assembly is installed in the central area of the core chamber; Install the venting and exhaust pipe for the descending annular cavity and its associated structures: Pass the lower end of the venting and exhaust pipe for the descending annular cavity through the through hole of the core lifting basket and seal and fix it through the third through sealing structure; Install the top cover and the through-sealing structure related to the top cover through hole: Pass the upper end of the cable lead-out pipe of the descending ring cavity level gauge and the upper end of the charging and venting pipe of the descending ring cavity through the corresponding top cover through hole, and seal and fix them respectively through the second through-sealing structure and the fourth through-sealing structure; Install the core chamber filling and venting pipes, filling and venting pipe tee sealing joints, and pressure transmitters; Install the core liquid level measuring level gauge: Insert the measuring end of the level gauge into the through hole of the top cover, and fix and seal it to the top cover through the level gauge fixing sealing flange to complete the installation of the entire system.
10. The installation method according to claim 9, characterized in that, The aforementioned installation of the electrical contact level gauge and its auxiliary structures specifically includes: Insert the electric contact level gauge into the level gauge guide tube of the level gauge integrated cylinder of the descending annular cavity, and seal it through the level gauge fixing and sealing structure. Welding and fixing the upper fixed bracket of the integrated cylinder of the level gauge, the lower fixed bracket of the integrated cylinder of the level gauge, and the descending annular cavity integrated cylinder of the level gauge; Welding and fixing the upper fixed support of the integrated cylinder of the level gauge, the lower fixed support of the integrated cylinder of the level gauge, and the core lifting basket; The upper fixing bracket of the integrated cylinder of the level gauge is connected to the upper fixing support of the integrated cylinder of the level gauge by bolts, and the lower fixing bracket of the integrated cylinder of the level gauge is connected to the lower fixing support of the integrated cylinder of the level gauge by bolts. Pass the lower end of the cable lead-out pipe of the descending annular level gauge through the through hole of the core basket, and weld the integrated cylinder of the descending annular level gauge to the cable lead-out pipe of the descending annular level gauge. The cable lead-out pipe of the descending annular cavity level gauge passing through the through hole of the core basket is sealed and fixed by the first through-sealing structure. The installation of the core chamber filling and venting pipe, the filling and venting pipe tee sealing joint, and the pressure transmitter specifically refers to: The lower end of the core chamber filling and venting pipe passes through the through hole in the top cover and is sealed and fixed by the fourth through sealing structure. Connect the upper ends of the core chamber filling and exhaust pipe and the descending ring cavity filling and exhaust pipe to the first interface of the filling and exhaust pipe tee sealing joint, respectively. Connect the pressure transmitter to the second port of the tee seal joint for the charging and discharging pipe, and connect the external charging and discharging system pipeline to the third port of the tee seal joint for the charging and discharging pipe.