Equivalent experimental device and experimental method for heat conduction process of reactor core outlet

Abstract

The invention relates to the technical field of reactors, and provides a reactor core outlet heat conduction process equivalent experiment device and method, the experiment device comprises a reactor pressure vessel and a cooling system, the reactor pressure vessel comprises a main body and a thermocouple measurement assembly, and the main body comprises a heat flow cavity, a cold flow cavity and a convection heat exchange cavity; a hot flow outlet is communicated between the hot flow cavity and the convection heat exchange cavity, and a cold flow outlet is communicated between the cold flow cavity and the convection heat exchange cavity; the thermocouple measuring assembly comprises a positioning part and a thermocouple, the positioning part is arranged in the convection heat exchange cavity and corresponds to the heat flow outlet, and the thermocouple can telescopically move in the positioning part in the axial direction so as to adjust the depth of the thermocouple inserted into the heat flow cavity through the heat flow outlet; and the cooling system is circularly connected with the hot flow cavity, the cold flow cavity and the convection heat exchange cavity respectively. According to the invention, the relation between the thermocouple insertion depth and the measurement temperature deviation under different boundary conditions can be researched, and more reliable technical support is provided for safe operation of the nuclear power station.

Description

Technical Field

[0001] The present application relates to the field of reactor technology, and in particular provides an equivalent experimental device and an experimental method for a core outlet heat conduction process. Background Art

[0002] Pressurized water reactors use light water (ordinary water) as a moderator and coolant and are the most technologically mature type of reactor. The heat conduction process at the reactor core outlet mainly includes the hot flow flowing out of the core outlet and the cold flow flowing down from the reactor top chamber. The two fluids mix with each other in the reactor upper chamber and then flow out of the reactor. The operating power of the reactor is different, and the heat flow temperature and flow rate at the core outlet are different.

[0003] The reactor core outlet temperature (heat flow temperature) is an important indicator for monitoring the reactor status. It is mainly measured by thermocouples in the core measurement system. Thermocouples need maintenance after long-term use. However, during the maintenance process, if the thermocouple is not installed properly, the core outlet temperature at the location of the thermocouple will be inaccurately measured, seriously affecting the operator's monitoring of the core status and causing major safety hazards in nuclear power plants. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide an equivalent experimental device and experimental method for the core outlet heat conduction process, aiming to solve the problem that the existing thermocouples are not properly installed in pressurized water reactor nuclear power plants, resulting in inaccurate core outlet temperature measured by the thermocouples.

[0005] To achieve the above purpose, the technical solution adopted in this application is:

[0006] The present application provides an equivalent experimental device for a core outlet heat conduction process, comprising:

[0007] A reactor pressure vessel, comprising a main body and a thermocouple measurement assembly, wherein the main body comprises a hot flow cavity, a cold flow cavity and a convection heat exchange cavity, wherein a hot flow outlet is communicated between the hot flow cavity and the convection heat exchange cavity, and a cold flow outlet is communicated between the cold flow cavity and the convection heat exchange cavity; the thermocouple measurement assembly comprises a positioning component and a thermocouple, wherein the positioning component is arranged in the convection heat exchange cavity and corresponds to the hot flow outlet, and the thermocouple can be telescopically moved in the positioning component along the axial direction to adjust the depth of the thermocouple inserted into the hot flow cavity through the hot flow outlet;

[0008] A cooling system is respectively connected to the hot flow chamber, the cold flow chamber and the convection heat exchange chamber in a circulation manner, and is used to provide a hot flow medium to the hot flow chamber and a cold flow medium to the cold flow chamber. The hot flow medium enters the convection heat exchange chamber through the hot flow outlet, and the cold flow medium enters the convection heat exchange chamber through the cold flow outlet.

[0009] The core outlet heat conduction process equivalent experimental device provided in this application can simulate the actual pressurized water reactor core outlet heat conduction heat exchange process, so as to study the relationship between the thermocouple insertion depth and the measured temperature deviation under different boundary conditions (such as different operating parameters of hot flow medium and cold flow medium), and provide a basis for the calibration of thermocouples. This helps to adjust or correct the position of the thermocouple according to the known relationship in practical applications, ensure the accuracy of its measured value, and thus ensure the safety and reliability of nuclear power plants.

[0010] Optionally, the main body includes:

[0011] A pressure shell, wherein a cover plate and a bottom plate are provided at both ends of the pressure shell to define the convection heat exchange cavity, the cover plate is provided with the cold flow outlet, the bottom plate is provided with the hot flow outlet, and both ends of the positioning component are connected to the cover plate and the bottom plate respectively;

[0012] A first flow guide cover connected to the pressure shell and defining the heat flow cavity between the bottom plate;

[0013] A second flow guide cover is connected to the pressure shell and defines the cold flow cavity with the cover plate.

[0014] Optionally, the positioning component includes:

[0015] A support tube, both ends of which are connected to the cover plate and the bottom plate respectively, and the support tube corresponds to the heat flow outlet;

[0016] A guide tube is arranged in the support tube, and an end plug is provided at one end of the guide tube adjacent to the heat flow outlet. The end plug is detachably connected to the end of the support tube adjacent to the heat flow outlet. The thermocouple is used to be clamped in the end plug through the guide tube, and the thermocouple can extend or retract the end plug.

[0017] Optionally, the pressure shell and the cover plate, the first flow guide cover and the second flow guide cover are all detachably connected, and a seal is provided at each connection.

[0018] Optionally, the cooling system comprises:

[0019] A storage tank, used for storing cooling medium, and the storage tank is connected to the pressure shell via a return main path;

[0020] A main supply path includes a circulation pump unit, wherein the circulation pump unit is connected to the storage tank;

[0021] A heat flow branch, comprising a first pressure reducing valve, a first electric heater and a first throttle valve connected in sequence, wherein the first pressure reducing valve is connected to the circulating pump unit, the first throttle valve is connected to the first flow guide cover, and the heat flow branch is used to adjust the cooling medium to the heat flow medium;

[0022] The cold flow branch includes a second pressure reducing valve, a second electric heater and a second throttle valve connected in sequence, and the second pressure reducing valve is connected to the circulating pump unit, and the second throttle valve is connected to the second guide cover. The cold flow branch is used to adjust the cooling medium to the cold flow medium.

[0023] Optionally, the heat flow branch further includes a first thermometer, a first flow meter and a first pressure gauge disposed between the first throttle valve and the first flow guide cover;

[0024] And / or, the cold flow branch further includes a second thermometer, a second flow meter and a second pressure gauge arranged between the second throttle valve and the second flow guide cover.

[0025] Optionally, the main supply path further comprises a filter, and the filter is connected between the storage tank and the input side of the circulating pump unit;

[0026] And / or, the main supply path further includes an overflow valve, and the overflow valve is connected between the output side of the circulating pump unit and the storage tank.

[0027] Optionally, the first electric heater is provided with a first safety valve and a first release valve;

[0028] And / or, the second electric heater is provided with a second safety valve and a second release valve.

[0029] Optionally, the thermocouple measurement assembly further includes a depth detection sensor, and the depth detection sensor is used to detect the insertion depth of the thermocouple.

[0030] Optionally, the core outlet heat conduction process equivalent experimental device further includes: a terminal, wherein the terminal is used to control the experimental process of the core outlet heat conduction process equivalent experimental device.

[0031] The present application also provides an experimental method for an equivalent experimental device for a core outlet heat conduction process, comprising:

[0032] According to the boundary conditions of different operating conditions, the operating parameters of the hot flow medium and the cold flow medium are set, and the operating parameters of the hot flow medium include temperature;

[0033] Adjusting the insertion depth of the thermocouple, and collecting the measured temperatures of the thermocouple at different insertion depths under the current boundary conditions, to obtain a plurality of first temperature field data, wherein the first temperature field data is the temperature field data of the thermocouple at different insertion depths under any of the boundary conditions;

[0034] Determining, based on the plurality of first temperature field data, the correlation between the insertion depth of the thermocouple and the temperature deviation under different boundary conditions;

[0035] The temperature deviation is the difference between the measured temperature of the thermocouple and the set temperature of the heat flow medium.

[0036] The experimental method of the core outlet heat conduction process equivalent experimental device provided in the present application can provide a basis for the calibration of thermocouples by studying the relationship between the thermocouple insertion depth and the measured temperature deviation under different boundary conditions (such as different operating parameters of the hot flow medium and the cold flow medium). This helps to adjust or correct the position of the thermocouple according to the known relationship in practical applications to ensure that the measured temperature is as close as possible to the actual temperature of the core outlet, thereby ensuring the safety and reliability of the nuclear power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 A schematic diagram of the structure of an equivalent experimental device for the core outlet heat conduction process provided in an embodiment of the present application;

[0039] Figure 2 A schematic diagram of the structure of a reactor pressure vessel provided in an embodiment of the present application;

[0040] Figure 3 A schematic diagram of the structure of a thermocouple measurement assembly provided in an embodiment of the present application;

[0041] Figure 4 A flow chart of an experimental method for an equivalent experimental device for the core outlet heat conduction process provided in an embodiment of the present application.

[0042] Among them, the reference numerals in the figure are:

[0043] 1. Reactor pressure vessel; 101. Main body; 102. Thermocouple measurement assembly; 103. Heat flow chamber;

[0044] 104, cold flow chamber; 105, convection heat exchange chamber; 106, hot flow outlet; 107, cold flow outlet;

[0045] 108. Positioning component; 109. Thermocouple; 110. Pressure shell; 111. First guide cover;

[0046] 112, second guide cover; 113, cover plate; 114, bottom plate; 115, fluid outlet; 116, support tube;

[0047] 117, guide tube; 118, end plug; 119, positioning guide cylinder; 120, claw-shaped connecting seat;

[0048] 121. threaded hole; 122. wire;

[0049] 2. Cooling system;

[0050] 201, storage tank; 202, return main road; 203, supply main road; 204, heat flow branch road;

[0051] 205, cold flow branch; 206, circulating pump unit; 207, first pressure reducing valve;

[0052] 208, a first electric heater; 209, a first throttle valve; 210, a second pressure reducing valve;

[0053] 211, second electric heater; 212, second throttle valve; 213, motor; 214, circulation pump;

[0054] 215. a first thermometer; 216. a first flowmeter; 217. a first pressure gauge;

[0055] 218, second thermometer; 219, second flowmeter; 220, second pressure gauge; 221, filter;

[0056] 222, overflow valve; 223, first safety valve; 224, first release valve; 225, second safety valve;

[0057] 226. Second release valve. DETAILED DESCRIPTION

[0058] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0059] In the description of the embodiments of the present application, it needs to be understood that the terms "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0060] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0061] In the embodiments of the present application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be 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 those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0062] The core outlet heat conduction process equivalent experimental device of the present application is intended to simulate the heat conduction process at the core outlet of a pressurized water reactor to study the relationship between the insertion depth of the thermocouple 109 and the measured temperature. The core outlet heat conduction process equivalent experimental device optimizes the installation and calibration process of the thermocouple 109 by providing a controllable simulation environment, thereby ensuring that the thermocouple 109 can accurately reflect the actual temperature of the core outlet in the actual operation of a nuclear power plant.

[0063] In one embodiment, referring to Figures 1 to 3As shown, the core outlet heat conduction process equivalent experimental device provided by the present application includes: a reactor pressure vessel 1 and a cooling system 2. The reactor pressure vessel 1 includes a main body 101 and a thermocouple measurement assembly 102. The main body 101 includes a hot flow cavity 103, a cold flow cavity 104 and a convection heat exchange cavity 105. A hot flow outlet 106 is connected between the hot flow cavity 103 and the convection heat exchange cavity 105, and a cold flow outlet 107 is connected between the cold flow cavity 104 and the convection heat exchange cavity 105. The thermocouple measurement assembly 102 includes a positioning component 108 and a thermocouple 109. The positioning component 108 is arranged in the convection heat exchange cavity 105 and corresponds to the hot flow outlet. 106, the thermocouple 109 can be axially telescopically moved in the positioning component 108 to adjust the depth of the thermocouple 109 inserted into the hot flow cavity 103 through the hot flow outlet 106; the cooling system 2 is respectively connected to the hot flow cavity 103, the cold flow cavity 104 and the convection heat exchange cavity 105 in a loop, and is used to provide a hot flow medium to the hot flow cavity 103 and a cold flow medium to the cold flow cavity 104, the hot flow medium enters the convection heat exchange cavity 105 through the hot flow outlet 106, and the cold flow medium enters the convection heat exchange cavity 105 through the cold flow outlet 107.

[0064] In this embodiment, the equivalent experimental device for the heat conduction process at the core outlet can provide a hot flow medium with set operating parameters (such as temperature, pressure, flow, etc.) to the hot flow cavity 103 of the main body 101 through the cooling system 2 to simulate the heat flow from the reactor core outlet, that is, the temperature of the hot flow medium is the real temperature of the core outlet; at the same time, a cold flow medium with set operating parameters (such as temperature, pressure, flow, etc.) can be provided to the cold flow cavity 104 of the main body 101 to simulate the cold flow flowing down from the top chamber of the reactor. The two fluid media enter the convection heat exchange cavity 105 of the main body 101 through the hot flow outlet 106 and the cold flow outlet 107 respectively, where they are mixed and simulate the real heat conduction process, and then flow back to the cooling system 2 after mixing to realize the cyclic heat exchange process.

[0065] In the thermocouple measurement assembly 102 , the positioning component 108 can realize the positioning and installation of the thermocouple 109 , thereby ensuring the stability of the thermocouple 109 and thus ensuring the accuracy of the experimental data.

[0066] The thermocouple 109 can extend out of the positioning component 108 or retract into the positioning component 108, so that the depth of the thermocouple 109 inserted into the heat flow cavity 103 through the heat flow outlet 106 can be adjusted. Specifically, by changing the insertion depth of the thermocouple 109, temperature data can be collected under different boundary conditions (such as different operating parameters of the hot flow medium and the cold flow medium). When the thermocouple 109 is fully extended into the heat flow cavity 103, it directly measures the temperature of the heat flow medium in the heat flow cavity 103, which represents the real temperature of the core outlet; if the thermocouple 109 is not fully extended, it will be affected by the mixed medium in the convection heat exchange cavity 105 (the mixed medium in the convection heat exchange cavity 105 conducts heat to the thermocouple 109 through the positioning component 108), resulting in a deviation in the measured temperature.

[0067] Under the set boundary conditions, by adjusting different insertion depths of the thermocouple 109 and recording the corresponding measured temperatures, the correlation (functional relationship) between the insertion depth of the thermocouple 109 and the temperature deviation (the difference between the measured temperature of the thermocouple 109 and the set temperature of the heat flow medium) can be obtained. This correlation can help determine the best installation position of the thermocouple 109 so as to obtain the most accurate temperature reading in practical applications.

[0068] According to the experimental results, the position of the thermocouple 109 can be adjusted during reactor calibration, and necessary corrections can be made to the measured temperature based on known correlations to ensure that the monitored temperature is as close as possible to the actual temperature at the core outlet, thereby improving the reliability of the thermocouple 109 measurement.

[0069] Therefore, the equivalent experimental device for the core outlet heat conduction process of the embodiment of the present application, through the study of temperature deviation at different insertion depths of the thermocouple 109, not only helps to understand the influence of the insertion depth of the thermocouple 109 on the temperature measurement accuracy, but also can provide more reliable technical support for the safe operation of the nuclear power plant.

[0070] In one embodiment, referring to Figure 2 As shown, the main body 101 includes: a pressure shell 110, a first flow guide cover 111 and a second flow guide cover 112, a cover plate 113 and a bottom plate 114 are provided at both ends of the pressure shell 110 to define a convection heat exchange cavity 105, the cover plate 113 is provided with a cold flow outlet 107, the bottom plate 114 is provided with a hot flow outlet 106, and both ends of the positioning component 108 are respectively connected to the cover plate 113 and the bottom plate 114; the first flow guide cover 111 is connected to the pressure shell 110 and defines a hot flow cavity 103 between the bottom plate 114; the second flow guide cover 112 is connected to the pressure shell 110 and defines a cold flow cavity 104 between the cover plate 113.

[0071] In this embodiment, the pressure shell 110 is the main frame of the entire reactor pressure vessel 1, and the upper and lower ends of the pressure shell 110 are respectively provided with a cover plate 113 and a bottom plate 114 to form a closed space for defining the convection heat exchange cavity 105. In addition, fluid outlets 115 can be provided on the left and right sides of the pressure shell 110 for connecting to the cooling system 2.

[0072] The first flow guide cover 111 is connected to the pressure shell 110 and defines a heat flow cavity 103 with the bottom plate 114, and a heat flow inlet may be provided at the bottom of the first flow guide cover 111 for connection with the cooling system 2. The heat flow medium provided by the cooling system 2 may enter the heat flow cavity 103 through the heat flow inlet on the first flow guide cover 111, and flush the thermocouple 109 on the positioning component 108 located at the bottom plate 114, so as to facilitate the temperature measurement of the thermocouple 109, and then enter the convection heat exchange cavity 105 through the heat flow outlet 106 on the bottom plate 114.

[0073] The second flow guide cover 112 is connected to the pressure shell 110 and defines a cold flow cavity 104 with the cover plate 113, and a cold flow inlet may be provided on the top of the second flow guide cover 112 for connecting with the cooling system 2. The cold flow medium provided by the cooling system 2 may enter the cold flow cavity 104 through the cold flow inlet on the second flow guide cover 112, and then enter the convection heat exchange cavity 105 through the cold flow outlet 107 on the cover plate 113.

[0074] In the convection heat exchange cavity 105 of the pressure shell 110, the hot flow medium from the hot flow cavity 103 meets and mixes with the cold flow medium from the cold flow cavity 104, and then flows back to the cooling system 2 through the fluid outlet 115 of the pressure shell 110, simulating the heat conduction process at the core outlet of the actual reactor. The thermocouple 109 measures the temperature during this process, and its position can be adjusted as needed to study the influence of different insertion depths on the measurement results.

[0075] The first flow guide cover 111 and the second flow guide cover 112 not only play the role of dividing different functional areas (hot flow chamber 103 and cold flow chamber 104), but also play a guiding role, ensuring that the hot flow medium and the cold flow medium can accurately flow into the corresponding chamber according to the designed path, and finally merge into the convection heat exchange chamber 105 for mixing, which is beneficial to improve the reliability of the experiment.

[0076] In some examples, reference Figure 2 As shown, the number of the hot flow outlets 106 and the cold flow outlets 107 can be multiple to improve the uniformity and efficiency of the flow of the fluid medium.

[0077] In one embodiment, referring to Figure 2 and Figure 3As shown, the positioning component 108 includes: a support tube 116, a guide tube 117 and an end plug 118, the two ends of the support tube 116 are respectively connected to the cover plate 113 and the bottom plate 114, and the support tube 116 corresponds to the hot flow outlet 106; the guide tube 117 is arranged in the support tube 116, and an end plug 118 is provided at one end of the guide tube 117 adjacent to the hot flow outlet 106, and the end plug 118 is detachably connected to one end of the support tube 116 adjacent to the hot flow outlet 106, and the thermocouple 109 is used to be clamped in the end plug 118 through the guide tube 117, and the thermocouple 109 can extend or retract the end plug 118.

[0078] In this embodiment, the positioning component 108 is designed to accurately control the position of the thermocouple 109 in the equivalent experimental device of the core outlet heat conduction process, ensuring that it can accurately simulate the installation and measurement conditions of the thermocouple 109 in the reactor.

[0079] The upper and lower ends of the support tube 116 are connected to the cover plate 113 and the bottom plate 114 respectively. Specifically, a positioning guide tube 119 is provided on the cover plate 113, and the upper end of the support tube 116 is fixed by the positioning guide tube 119; the lower end of the support tube 116 is provided with a claw-shaped connection seat 120, and the claw-shaped connection seat 120 is provided with a threaded hole 121, which can be connected to the threaded hole on the bottom plate 114 by bolts, so as to achieve a stable connection. The main function of the support tube 116 is to provide a stable frame for accommodating the internal guide tube 117 and the end plug 118, and to ensure that the thermocouple 109 can be inserted into the heat flow cavity 103 below through the heat flow outlet 106.

[0080] The guide tube 117 is arranged inside the support tube 116, and is mainly used for guiding the installation of the thermocouple 109, so as to simulate the guide structure of the actual installation of the thermocouple 109 in the reduction reactor. The guide tube 117 ensures that the thermocouple 109 can move telescopically along the correct path without deviating from the predetermined position.

[0081] The end plug 118 can be connected to the inner wall of the claw-shaped connection seat 120 at the lower end of the support tube 116 by threads. This design facilitates the removal of the end plug 118, and then adjusts the position of the thermocouple 109 on the end plug 118. The thermocouple 109 is clamped in the end plug 118, and the stability and position accuracy of the thermocouple 109 are ensured by the end plug 118. The end plug 118 serves as a positioning and guide structure for the thermocouple 109, allowing the thermocouple 109 to extend or retract, so as to adjust the insertion depth of the thermocouple 109 in the heat flow chamber 103.

[0082] It is understandable that the thermocouple 109 is clamped in the end plug 118 through the guide tube 117, and the end plug 118 can be extended or retracted as needed. This allows the operator to flexibly adjust the insertion depth of the thermocouple 109 in the heat flow cavity 103 without affecting the overall structure, so as to study the influence of different insertion depths on temperature measurement.

[0083] Furthermore, the design of the positioning component 108 imitates the installation method of the thermocouple 109 in an actual nuclear power plant, ensuring that the experimental conditions are as close to the actual working conditions as possible, thereby improving the reliability and applicability of the experimental results.

[0084] Therefore, the positioning component 108 of the embodiment of the present application is designed to cleverly combine the support tube 116, the guide tube 117 and the end plug 118, which not only provides a stable support and precise guidance for the thermocouple 109, but also greatly improves the flexibility and convenience of adjusting the position of the thermocouple 109. This design helps to more accurately simulate the heat conduction process at the reactor core outlet, which is of great significance for improving the accuracy of temperature measurement and ensuring the safe operation of nuclear power plants.

[0085] In one embodiment, referring to Figure 2 As shown, the pressure shell 110 and the cover plate 113, the first flow guide cover 111 and the second flow guide cover 112 are all detachably connected, and a sealing member (not shown in the figure) is provided at each connection.

[0086] In this embodiment, the pressure shell 110 and the cover plate 113, the first flow guide cover 111 and the second flow guide cover 112 can be connected by bolts. This connection method not only ensures the stability of the structure, but also facilitates disassembly and assembly, so that the reactor pressure vessel 1 can be easily opened to inspect, adjust or replace internal components when necessary.

[0087] In addition, sealing rings and other seals are installed at each joint to ensure the airtightness of the entire device, which is crucial for simulating the working conditions in a real reactor environment and avoiding leakage that affects the accuracy of the experimental results.

[0088] It is understandable that, due to the complex and closed structure of the conventional reactor, it is difficult to directly observe and adjust the installation position of the thermocouple 109. However, the reactor pressure vessel 1 in the embodiment of the present application can be disassembled, allowing the operator to directly access the internal structure, so that the insertion depth of the thermocouple 109 can be quickly and accurately adjusted. This is very important for studying the influence of different insertion positions of the thermocouple 109 on temperature measurement.

[0089] Through this precisely controllable equivalent experimental device for the core outlet heat conduction process, we can better understand the measurement accuracy of the thermocouple 109 in different installation positions, thereby ensuring the correct installation of the thermocouple 109 in the actual nuclear power plant, providing accurate and reliable temperature data, and ensuring the safe operation of the nuclear power plant.

[0090] Therefore, the reactor pressure vessel of the embodiment of the present application achieves precise control of the installation position of the thermocouple 109 by adopting a detachable connection design, greatly enhancing the flexibility and reliability of the experiment, and providing strong support for the research and improvement of temperature measurement technology.

[0091] In some examples, reference Figure 2 As shown, the number of thermocouple measurement assemblies 102 can be multiple groups, and the multiple groups of thermocouple measurement assemblies 102 are arranged at intervals along the radial direction of the reactor pressure vessel 1. For example, the number of thermocouple measurement assemblies 102 can be three groups or other numbers, which can be specifically designed and adjusted according to actual working conditions.

[0092] In this embodiment, the thermocouple measurement components 102 can be arranged in multiple groups, each group including a positioning component 108 and a thermocouple 109. These components are arranged at intervals along the radial direction of the reactor pressure vessel 1 to ensure that the temperature at different positions from the center to the edge can be accurately measured.

[0093] The multiple sets of thermocouple measurement components 102 can provide more detailed temperature distribution information. By arranging them radially, temperature data can be collected at different radii at the same time, which helps to establish a more complete temperature field model and better reflect the heat conduction characteristics inside the container. In addition, the temperature at different locations may vary due to factors such as fluid flow and mixing. The multiple sets of thermocouple measurement components 102 can capture these subtle changes, thereby improving the overall measurement accuracy and reducing the errors that may be caused by a single measurement point.

[0094] This arrangement allows researchers to select different measurement points for comparative analysis as needed, or to monitor data from multiple locations simultaneously under the same experimental conditions, increasing the flexibility and diversity of experimental design.

[0095] Refer to the following Figure 1 The cooling system 2 provided in the present application is continued to be described.

[0096] In one embodiment, referring to Figure 1As shown, the cooling system 2 includes: a storage tank 201 , a return main path 202 , a supply main path 203 , a hot flow branch 204 and a cold flow branch 205 . Among them, the storage tank 201 is used to store the cooling medium, and the storage tank 201 is connected to the pressure shell 110 via the return main path 202; the supply main path 203 includes a circulating pump unit 206, and the circulating pump unit 206 is connected to the storage tank 201; the hot flow branch 204 includes a first pressure reducing valve 207, a first electric heater 208 and a first throttle valve 209 connected in sequence, and the first pressure reducing valve 207 is connected to the circulating pump unit 206, and the first throttle valve 209 is connected to the first guide cover 111, and the hot flow branch 204 is used to adjust the cooling medium to a hot flow medium; the cold flow branch 205 includes a second pressure reducing valve 210, a second electric heater 211 and a second throttle valve 212 connected in sequence, and the second pressure reducing valve 210 is connected to the circulating pump unit 206, and the second throttle valve 212 is connected to the second guide cover 112, and the cold flow branch 205 is used to adjust the cooling medium to a cold flow medium.

[0097] In this embodiment, the storage tank 201 is used to store a cooling medium, and the cooling medium may be cooling water, for example.

[0098] The main supply path 203 includes a circulating pump unit 206 composed of a motor 213 and a circulating pump 214, which can adjust the maximum working flow of the cooling medium. The motor 213 drives the circulating pump 214 to work, and the circulating pump 214 is connected to the storage tank 201 and is responsible for extracting the cooling medium from the storage tank 201 and sending it to the subsequent processing link.

[0099] The heat flow branch 204 includes a first pressure reducing valve 207, a first electric heater 208 and a first throttle valve 209 connected in sequence. The first pressure reducing valve 207 is connected to the circulation pump 214 and is used to adjust the pressure of the cooling medium entering the heat flow branch 204. The first electric heater 208 is used to heat the cooling medium to a desired temperature and convert it into a heat flow medium. The first throttle valve 209 is connected to the heat flow inlet of the first guide cover 111 and is used to adjust the flow rate of the heat flow medium and introduce it into the heat flow chamber 103.

[0100] The cold flow branch 205 includes a second pressure reducing valve 210, a second electric heater 211 and a second throttle valve 212 connected in sequence. The second pressure reducing valve 210 is also connected to the circulation pump 214, and is used to adjust the pressure of the cooling medium entering the cold flow branch 205. The second electric heater 211 is used to heat the cooling medium to a lower temperature to simulate the cold flow medium. The second throttle valve 212 is connected to the cold flow inlet of the second guide cover 112, and is used to adjust the flow rate of the cold flow medium and introduce it into the cold flow chamber 104.

[0101] The main return path 202 connects the fluid outlet 115 of the reactor pressure vessel 1 and the storage tank 201, so that the medium after completing the cold and hot flow mixed heat exchange process through the convection heat exchange cavity 105 can flow back to the storage tank 201, forming a complete circulation path.

[0102] When the cooling system 2 is working, the cooling medium in the storage tank 201 is drawn out under the drive of the motor 213 and the circulating pump 214, and is divided into two paths to enter the hot flow branch 204 and the cold flow branch 205 for treatment. After the pressure of the cooling medium is adjusted by the first pressure reducing valve 207, it is heated by the first electric heater 208 to become a hot flow medium, and then the flow is adjusted by the first throttle valve 209, and finally enters the hot flow chamber 103 through the hot flow inlet of the first guide cover 111. Similarly, another part of the cooling medium is adjusted in pressure by the second pressure reducing valve 210, heated by the second electric heater 211 to become a cold flow medium (relative to the hot flow medium at a lower temperature), and then the flow is adjusted by the second throttle valve 212, and finally enters the cold flow chamber 104 through the cold flow inlet of the second guide cover 112. The hot flow medium and the cold flow medium meet and mix in the convection heat exchange chamber 105, simulating the cold and hot flow mixing heat exchange process in the actual reactor. The medium after completing the heat exchange flows out from the fluid outlet 115 of the reactor pressure vessel 1 and returns to the storage pool 201 through the reflux main path 202 to prepare for the next cycle.

[0103] Therefore, the design of the cooling system of the embodiment of the present application can accurately simulate the complex heat conduction process in the reactor, realize the independent control of the reactor boundary conditions, including the independent adjustment of operating parameters such as temperature, pressure and flow, so as to simulate the boundary condition changes of the reactor under different operating powers. This highly controllable experimental environment is helpful for in-depth research on the factors affecting the measurement accuracy of the thermocouple 109 and improving the safety and reliability of nuclear power plant operation.

[0104] In one embodiment, referring to Figure 1 As shown, the heat flow branch 204 also includes a first thermometer 215, a first flow meter 216 and a first pressure gauge 217 arranged between the first throttle valve 209 and the first guide cover 111, which are used to monitor the temperature, flow and pressure of the heat flow medium in real time, realize closed-loop control of various parameters of the heat flow medium, and ensure that it meets the preset conditions.

[0105] The embodiments of the present application can significantly improve the monitoring capability of the heat flow medium parameters and achieve precise control of various parameters of the heat flow medium.

[0106] In one embodiment, referring to Figure 1As shown, the cold flow branch 205 also includes a second thermometer 218, a second flow meter 219 and a second pressure gauge 220 arranged between the second throttle valve 212 and the second guide cover 112, which are used to monitor the temperature, flow and pressure of the cold flow medium in real time, realize closed-loop control of various parameters of the cold flow medium, and ensure that it meets the preset conditions.

[0107] The embodiments of the present application can significantly improve the monitoring capability of cold flow medium parameters and achieve precise control of various parameters of the cold flow medium.

[0108] In one embodiment, referring to Figure 1 As shown, the main supply path 203 further includes a filter 221 , and the filter 221 is connected between the storage tank 201 and the input side of the circulation pump unit 206 .

[0109] In this embodiment, the filter 221 is located between the storage tank 201 and the input side of the circulating pump 214 of the circulating pump unit 206, which means that all cooling medium drawn from the storage tank 201 will first pass through the filter 221. The main function of the filter 221 is to remove impurities and particulate matter in the cooling medium, such as rust, silt, microorganisms, etc., to prevent these impurities from entering the circulating pump 214 and other components, causing blockage or wear, thereby extending the service life of the equipment.

[0110] It is understood that the presence of impurities will reduce the heat exchange efficiency because they are deposited on the inner wall of the pipe or the heat exchange surface to form a heat insulation layer. By using the filter 221 to keep the cooling medium clean, the best heat transfer efficiency can be ensured.

[0111] Furthermore, in the experiment of simulating the heat conduction process of the reactor, the purity of the cooling medium directly affects the measurement accuracy of parameters such as temperature and pressure. The application of the filter 221 ensures the consistency and accuracy of the experimental conditions and provides more reliable experimental data.

[0112] Therefore, the embodiment of the present application adds a filter 221 to the main supply path 203, which significantly improves the overall performance and reliability of the cooling system 2. By ensuring the cleanliness of the cooling medium in the system, not only the various components are protected from damage, but also the heat conduction efficiency and the accuracy of the experimental results are improved.

[0113] In one embodiment, referring to Figure 1 As shown, the main supply path 203 also includes an overflow valve 222 , and the overflow valve 222 is connected between the output side of the circulation pump unit 206 and the storage tank 201 .

[0114] In this embodiment, one end of the relief valve 222 is connected to the output side of the circulating pump 214 of the circulating pump unit 206, and the other end is connected to the storage tank 201. When the pressure in the system exceeds the set safety upper limit, the relief valve 222 automatically opens to release the excess high-pressure cooling medium back to the storage tank 201 to prevent equipment damage or safety accidents caused by overpressure. By adjusting the opening pressure of the relief valve 222, the pressure in the system can be maintained within a safe and stable range to avoid the influence of pressure fluctuations on the experimental results.

[0115] Therefore, the embodiment of the present application adds a design of an overflow valve 222 to the main supply path 203, which significantly enhances the safety and reliability of the cooling system 2 and provides a stable and reliable operating environment for the experiment.

[0116] In one embodiment, referring to Figure 1 As shown, the first electric heater 208 is provided with a first safety valve 223 and a first release valve 224, which are used to ensure that the system pressure after heating is within a safe range, thereby improving the safety and reliability of the system.

[0117] In one embodiment, referring to Figure 1 As shown, the second electric heater 211 is provided with a second safety valve 225 and a second release valve 226, which are used to ensure that the system pressure after heating is within a safe range, thereby improving the safety and reliability of the system.

[0118] In one embodiment, the thermocouple measurement assembly 102 further includes a depth detection sensor (not shown in the figure), and the depth detection sensor is used to detect the insertion depth of the thermocouple 109 .

[0119] In this embodiment, the depth detection sensor can be installed near the positioning component (such as the support tube 116, the guide tube 117, etc.), and can be built-in or external, depending on the sensor type and design requirements.

[0120] The depth detection sensor can monitor the insertion depth of the thermocouple 109 relative to the reference point in real time and provide high-precision position information. By feeding back the sensor data to the terminal, the insertion depth of the thermocouple 109 can be accurately adjusted to ensure the consistency of each experimental condition.

[0121] During the experiment, if it is detected that the insertion depth of the thermocouple 109 deviates from the set value, the terminal can prompt the position of the thermocouple 109 based on the information provided by the sensor, and the researchers can calibrate based on the provided position data to ensure that the position of the thermocouple 109 meets the experimental requirements.

[0122] Therefore, the real-time data provided by the depth detection sensor in the embodiment of the present application helps researchers to better understand the impact of the insertion depth of the thermocouple 109 on the measurement results and optimize the experimental design and parameter setting.

[0123] In some other examples, refer to Figure 2 As shown, the thermocouple 109 is connected to a wire 122, which is passed through the guide tube 117 and extends to the outside of the reactor pressure vessel 1 to be connected to the terminal. Therefore, the insertion depth of the thermocouple 109 can also be indirectly obtained by detecting the telescopic movement distance of the wire 122 of the thermocouple 109.

[0124] In one embodiment, the core outlet heat conduction process equivalent experimental device further includes: a terminal (not shown in the figure), which is used to control the experimental process of the core outlet heat conduction process equivalent experimental device.

[0125] In this embodiment, the terminal may include components such as a power supply module, a data acquisition module, a processor and a display module.

[0126] The power supply module can provide a stable and reliable power supply for the core outlet heat conduction process equivalent experimental device, ensuring that all components (such as electric heaters, circulating pumps 214, sensors, etc.) can operate under stable voltage and current.

[0127] The data acquisition module is responsible for collecting data from various sensors (such as thermometers, flow meters, pressure gauges, depth detection sensors, etc.) in real time and transmitting the data to the processor for analysis and processing.

[0128] The processor serves as a control unit. The processor receives information from the data acquisition module, executes the preset control logic, adjusts the various components in the equivalent experimental device of the core outlet heat conduction process (such as adjusting the valve opening, controlling the heating power, etc.), and records and analyzes the experimental data.

[0129] The display module can display the experimental status and various parameters (such as temperature, flow, pressure, insertion depth of thermocouple 109, etc.) in real time in the form of a graphical interface, and provide alarm prompts.

[0130] Therefore, the embodiment of the present application not only realizes comprehensive control of the experimental process through the design of the terminal, but also provides researchers with a convenient operating experience and detailed data support, significantly improving the automation level and reliability of the equivalent experimental device of the core outlet heat conduction process.

[0131] In one embodiment, referring to Figure 4 As shown, the present application also provides an experimental method for an equivalent experimental device for a core outlet heat conduction process, comprising the following steps:

[0132] S401. According to the boundary conditions of different operating conditions, the operating parameters of the hot flow medium and the cold flow medium are set, and the operating parameters of the hot flow medium include temperature.

[0133] Before the test, turn on the power supply to ensure that all components of the equivalent experimental device for the core outlet heat conduction process are connected correctly, especially key parts such as the power supply module, cooling system, and sensors. Check all seals to ensure that the device is airtight to prevent leakage from affecting the experimental results. According to the experimental requirements, set different operating boundary conditions, such as the temperature, pressure, and flow rate of the hot flow medium and the cold flow medium. Specifically, use the feedback parameters of the thermometer, flowmeter, and pressure gauge to adjust each device (such as the pressure reducing valve, electric heater, throttle valve, etc.) so that the temperature, pressure, and flow rate of the hot flow medium and the cold flow medium reach the target set value of the current boundary conditions.

[0134] S402, adjusting the insertion depth of the thermocouple 109, and collecting the measured temperatures of the thermocouple 109 at different insertion depths under the current boundary conditions, to obtain a plurality of first temperature field data, wherein the first temperature field data is the temperature field data of the thermocouple 109 at different insertion depths under any boundary condition.

[0135] During the experimental phase, the current boundary conditions (i.e., the set parameters of the current medium) and the insertion depth of the thermocouple 109 are recorded. The temperature at the insertion depth is measured by the thermocouple 109, and the data is transmitted to the data acquisition module of the terminal for storage. After the data acquisition is completed, the second guide cover 112 and the support cylinder 116 are opened, the end plug 118 is removed, and the insertion depth of the thermocouple 109 is adjusted.

[0136] The above steps are repeated to collect temperature field data of the thermocouple 109 at different insertion depths under different boundary conditions.

[0137] S403 . Determine, based on the plurality of first temperature field data, the correlation between the insertion depth of the thermocouple 109 and the temperature deviation under different boundary conditions.

[0138] The collected temperature field data is compared and analyzed with the set temperature value, and the temperature deviation is calculated, that is, the difference between the measured temperature of the thermocouple 109 and the set temperature of the heat flow medium. Statistical analysis or mathematical modeling methods can be used to analyze the changing trend of the temperature deviation under different insertion depths, and establish a functional relationship between the insertion depth of the thermocouple 109 and the temperature deviation under different boundary conditions. According to the obtained functional relationship, the optimal installation position of the thermocouple 109 is optimized to improve the accuracy of temperature measurement.

[0139] Therefore, the experimental method provided in the embodiment of the present application ensures accurate simulation of the heat conduction process under different operating conditions and in-depth study of the influence of the insertion depth of the thermocouple 109 through systematic steps. By analyzing the correlation between the insertion depth of the thermocouple 109 and the temperature deviation, the best installation position of the thermocouple 109 can be found, thereby improving the accuracy and reliability of temperature measurement. This is of great significance for optimizing the safe operation of nuclear power plants, improving thermocouple technology, and other industrial applications. Through this method, researchers can obtain more detailed and reliable data support to promote the development of nuclear energy technology.

[0140] In addition, this experimental method is not only applicable to laboratory environments, but can also provide a scientific basis for the installation and calibration of thermocouples in actual nuclear power plants, ensuring their accuracy and stability under complex working conditions.

[0141] The above are only preferred embodiments of the present application and are not intended to limit the embodiments of the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the embodiments of the present application should be included in the protection scope of the embodiments of the present application.

Claims

1. An equivalent experimental device for the heat conduction process at the core outlet, characterized in that: include: A reactor pressure vessel, comprising a main body and a thermocouple measurement assembly, wherein the main body comprises a hot flow cavity, a cold flow cavity and a convection heat exchange cavity, wherein a hot flow outlet is communicated between the hot flow cavity and the convection heat exchange cavity, and a cold flow outlet is communicated between the cold flow cavity and the convection heat exchange cavity; the thermocouple measurement assembly comprises a positioning component and a thermocouple, wherein the positioning component is arranged in the convection heat exchange cavity and corresponds to the hot flow outlet, and the thermocouple can be telescopically moved in the positioning component along the axial direction to adjust the depth of the thermocouple inserted into the hot flow cavity through the hot flow outlet; A cooling system is respectively connected to the hot flow chamber, the cold flow chamber and the convection heat exchange chamber in a circulation manner, and is used to provide a hot flow medium to the hot flow chamber and a cold flow medium to the cold flow chamber. The hot flow medium enters the convection heat exchange chamber through the hot flow outlet, and the cold flow medium enters the convection heat exchange chamber through the cold flow outlet.

2. The core outlet heat conduction process equivalent experimental device according to claim 1 is characterized in that: The subject includes: A pressure shell, wherein a cover plate and a bottom plate are provided at both ends of the pressure shell to define the convection heat exchange cavity, the cover plate is provided with the cold flow outlet, the bottom plate is provided with the hot flow outlet, and both ends of the positioning component are connected to the cover plate and the bottom plate respectively; A first flow guide cover connected to the pressure shell and defining the heat flow cavity between the bottom plate; A second flow guide cover is connected to the pressure shell and defines the cold flow cavity with the cover plate.

3. The core outlet heat conduction process equivalent experimental device according to claim 2, characterized in that: The positioning component comprises: A support tube, both ends of which are connected to the cover plate and the bottom plate respectively, and the support tube corresponds to the heat flow outlet; A guide tube is arranged in the support tube, and an end plug is provided at one end of the guide tube adjacent to the heat flow outlet. The end plug is detachably connected to the end of the support tube adjacent to the heat flow outlet. The thermocouple is used to be clamped in the end plug through the guide tube, and the thermocouple can extend or retract the end plug.

4. The core outlet heat conduction process equivalent experimental device according to claim 2, characterized in that: The pressure shell and the cover plate, the first flow guide cover and the second flow guide cover are all detachably connected, and a sealing member is provided at each connection.

5. The core outlet heat conduction process equivalent experimental device according to claim 2, characterized in that: The cooling system comprises: A storage tank, used for storing cooling medium, and the storage tank is connected to the pressure shell via a return main path; A main supply path includes a circulation pump unit, wherein the circulation pump unit is connected to the storage tank; A heat flow branch, comprising a first pressure reducing valve, a first electric heater and a first throttle valve connected in sequence, wherein the first pressure reducing valve is connected to the circulating pump unit, the first throttle valve is connected to the first flow guide cover, and the heat flow branch is used to adjust the cooling medium to the heat flow medium; The cold flow branch includes a second pressure reducing valve, a second electric heater and a second throttle valve connected in sequence, and the second pressure reducing valve is connected to the circulating pump unit, and the second throttle valve is connected to the second guide cover. The cold flow branch is used to adjust the cooling medium to the cold flow medium.

6. The core outlet heat conduction process equivalent experimental device according to claim 5, characterized in that: The heat flow branch further includes a first thermometer, a first flow meter and a first pressure gauge disposed between the first throttle valve and the first flow guide cover; And / or, the cold flow branch further includes a second thermometer, a second flow meter and a second pressure gauge arranged between the second throttle valve and the second flow guide cover.

7. The equivalent experimental device for the core outlet heat conduction process according to claim 5, characterized in that: The main supply path further comprises a filter, and the filter is connected between the storage tank and the input side of the circulating pump unit; And / or, the main supply path further includes an overflow valve, and the overflow valve is connected between the output side of the circulating pump unit and the storage tank.

8. The core outlet heat conduction process equivalent experimental device according to claim 5, characterized in that: The first electric heater is provided with a first safety valve and a first release valve; And / or, the second electric heater is provided with a second safety valve and a second release valve.

9. The core outlet heat conduction process equivalent experimental device according to claim 1, characterized in that: The thermocouple measurement assembly further includes a depth detection sensor, and the depth detection sensor is used to detect the insertion depth of the thermocouple.

10. The equivalent experimental device for core outlet heat conduction process according to any one of claims 1 to 9, characterized in that: Also includes: The terminal is used to control the experimental process of the equivalent experimental device for the core outlet heat conduction process.

11. An experimental method for an equivalent experimental device for core outlet heat conduction process according to any one of claims 1 to 10, characterized in that: include: According to the boundary conditions of different operating conditions, the operating parameters of the hot flow medium and the cold flow medium are set, and the operating parameters of the hot flow medium include temperature; Adjusting the insertion depth of the thermocouple, and collecting the measured temperatures of the thermocouple at different insertion depths under the current boundary conditions, to obtain a plurality of first temperature field data, wherein the first temperature field data is the temperature field data of the thermocouple at different insertion depths under any of the boundary conditions; Determining, based on the plurality of first temperature field data, the correlation between the insertion depth of the thermocouple and the temperature deviation under different boundary conditions; The temperature deviation is the difference between the measured temperature of the thermocouple and the set temperature of the heat flow medium.

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