A lead bismuth level gauge experimental system and method

Abstract

This invention belongs to the field of liquid metal level measurement technology, specifically relating to an experimental system and method for lead-bismuth level gauges. The invention includes a lead-bismuth calibration tank, a lead-bismuth storage tank, and an auxiliary support system. A lead-bismuth calibration source, a lead-bismuth level switch, and two sets of lead-bismuth level gauges are installed along the tank's axis inside the calibration tank. A weighing sensor is located at the bottom of the calibration tank. The lead-bismuth level switch is mounted inside the calibration tank via a sliding rail mounting base. The lead-bismuth storage tank is connected to the calibration tank via a pipeline. This invention verifies the accuracy of the lead-bismuth level gauges through benchmark calibration and cross-validation. Based on weighing-based hydrostatic pressure conversion, combined with hardware position fine-tuning and software parameter correction, the calibration of the lead-bismuth level switch is completed. Furthermore, the stability of the level switch can be verified through cyclic testing at a specified temperature.

Description

Technical Field

[0001] This invention belongs to the field of liquid metal level measurement technology, specifically relating to an experimental system and method for a lead-bismuth level gauge. Background Technology

[0002] Lead-bismuth alloys are highly corrosive at high temperatures and have a high melting point, remaining solid at room temperature. These characteristics pose significant challenges to liquid level measurement. Currently, there is no specific calibration procedure in the industry for lead-bismuth level gauges, lead-bismuth level switches, and their specific operating conditions. Existing calibration technologies mostly focus on the calibration of conventional liquid levels for general media.

[0003] Patent 202010202249.6 ("A Capacitive Liquid Level Sensor and Its Calibration and Measurement Method") proposes a method for calibrating the liquid level of ordinary media using a multi-capacitor structure. Patent 201410480817.3 ("A Device and Method for Measuring the Liquid Level of High-Temperature Melt in a Metallurgical Furnace") proposes a method for measuring high-temperature melt using a rod-type probe. Patent 202411452987.0 ("A Method, Device and Measurement System for Measuring and Correcting the Liquid Level of a Reactor Pressure Vessel") proposes a method for measuring and correcting the liquid level using a differential pressure method. None of these methods have been adapted to the characteristics of lead-bismuth alloys, such as high-temperature strong corrosion, easy solidification at room temperature, and significant density changes with temperature. They also lack a specific calibration logic for liquid level measuring equipment in lead-bismuth environments, and therefore cannot meet the requirements for accurate calibration and long-term stable verification of liquid level measuring equipment under special working conditions of lead-bismuth.

[0004] Existing liquid level gauge testing systems are mostly focused on the aforementioned single conventional scenarios. They cannot meet the special requirements of lead-bismuth alloys, such as high temperature, oxidation prevention, and solidification prevention. They also lack structural designs adapted to their strong corrosiveness and have not formed a specific calibration process for lead-bismuth liquid level gauges, lead-bismuth liquid level switches, and their specific operating conditions. As a result, the accuracy and reliability of liquid level measurement equipment specifically designed for lead-bismuth environments cannot be fully verified. Therefore, there is an urgent need for a targeted lead-bismuth liquid level gauge testing system. Summary of the Invention

[0005] The purpose of this invention is to provide an experimental system and method for lead-bismuth level gauges.

[0006] An experimental system for lead-bismuth level gauges includes a lead-bismuth calibration tank, a lead-bismuth storage tank, and an auxiliary support system. The lead-bismuth calibration tank contains a lead-bismuth calibration source, a lead-bismuth level switch, and two sets of lead-bismuth level gauges installed along the tank's axis. A weighing sensor is located at the bottom of the lead-bismuth calibration tank. The lead-bismuth level switch is installed inside the lead-bismuth calibration tank via a sliding rail mounting base. The lead-bismuth storage tank is connected to the lead-bismuth calibration tank via a pipeline. The auxiliary support system includes a heating system and a protective gas supply system.

[0007] Furthermore, the lead-bismuth level switch is connected to a weighing sensor; the net weight of lead-bismuth in the lead-bismuth calibration tank is calculated based on the measurement value of the weighing sensor; the static pressure of the lead-bismuth liquid phase in the lead-bismuth calibration tank is calculated based on the effective cross-sectional area of ​​the lead-bismuth calibration tank; the calculated value of the static pressure of the lead-bismuth liquid phase is corrected based on the real-time gas pressure in the lead-bismuth calibration tank; the actual lead-bismuth level is calculated based on the lead-bismuth density at the current temperature and the corrected static pressure of the lead-bismuth liquid phase; the actual lead-bismuth level is compared with a preset threshold to trigger the lead-bismuth level switch.

[0008] Furthermore, the lead-bismuth level switch incorporates an internal signal processing module and a static pressure conversion and threshold determination unit. The signal input terminal of the lead-bismuth level switch is connected to a weighing sensor via a high-temperature shielded cable. The weight signal collected by the weighing sensor is transmitted to the internal signal processing module for initial filtering and amplification, and then transmitted to the static pressure conversion and threshold determination unit to perform calculations of the static pressure of the lead-bismuth liquid phase and the actual lead-bismuth level, and triggers the lead-bismuth level switch according to a preset threshold.

[0009] Furthermore, the heat tracing system covers the lead-bismuth calibration tank, the lead-bismuth storage tank, and all connecting pipes, and is used to maintain the lead-bismuth liquid state.

[0010] Furthermore, the protective gas supply system is connected to the lead-bismuth calibration tank and the lead-bismuth storage tank via pipelines. The protective gas supply system is equipped with a gas supply pressure regulating controller to adjust the liquid level in the lead-bismuth calibration tank and prevent lead-bismuth oxidation.

[0011] Furthermore, the bottom of the lead-bismuth calibration vessel is a hemispherical chamber. The lead-bismuth storage tank is connected to the lead-bismuth calibration vessel through a filling pipe and a return pipe. The return pipe is connected to the lowest point of the bottom of the lead-bismuth calibration vessel. The filling pipe is connected to the bottom of the lead-bismuth calibration vessel and is positioned higher than the connection point of the return pipe. The filling pipe is equipped with a filter device.

[0012] Furthermore, the lead-bismuth storage tank is provided with a lead-bismuth drain hole at the bottom; a high-precision scale is provided on the outside of the sliding rail mounting base, and the high-precision scale is aligned with the metrological reference of the lead-bismuth calibration source; the outer layer of the lead-bismuth calibration tank is an insulation layer, and the inner layer is a pressure-bearing cavity; the protective gas supply system uses argon as the protective gas.

[0013] An experimental method for a lead-bismuth level gauge system includes calibration experiments for two sets of lead-bismuth level gauges:

[0014] Step 1.1: Set multiple temperature points and liquid level measuring points, sorted from low to high; use a heating system to heat the lead and bismuth in the lead and bismuth storage tank to the first temperature point and maintain a stable temperature;

[0015] Step 1.2: Using the lead-bismuth calibration source as a reference, adjust the lead-bismuth liquid level in the lead-bismuth calibration tank to the first liquid level measuring point through the protective gas supply system;

[0016] Step 1.3: Using two sets of lead-bismuth level gauges as a benchmark, conduct mutual verification, calculate the absolute error of the lead-bismuth level gauge at the current level measuring point relative to the lead-bismuth calibration source, and the relative error relative to the measurement value of the other set of lead-bismuth level gauges;

[0017] Step 1.4: If the absolute or relative error exceeds the allowable range, adjust the installation position of the two sets of lead-bismuth level gauges and return to step 1.3;

[0018] If both the absolute error and the relative error are within the allowable range, adjust the lead-bismuth liquid level in the lead-bismuth calibration tank to the next liquid level measuring point through the protective gas supply system, and return to step 1.3;

[0019] If the calibration of all liquid level measuring points has been completed, the lead and bismuth in the lead and bismuth storage tank will be heated to the next set of temperature points through the heating system, and then return to step 1.2;

[0020] The experiment ended after the two sets of lead-bismuth level gauges were calibrated at all temperature points.

[0021] Furthermore, after calibrating the two sets of level gauges, a calibration experiment was conducted on the lead-bismuth level switch:

[0022] Step 2.1: Heat the lead and bismuth in the lead and bismuth storage tank to the first temperature point using a heating system, and maintain the temperature stable;

[0023] Step 2.2: Position the lead-bismuth level switch to the first level measuring point using the slide rail mounting base;

[0024] Step 2.3: Adjust the lead-bismuth level in the lead-bismuth calibration tank through the protective gas supply system until the lead-bismuth level switch is triggered;

[0025] Step 2.4: Obtain the measurement value from the weighing sensor at the bottom of the lead-bismuth calibration container, subtract the weight of the lead-bismuth calibration container and piping accessories, and obtain the net weight of lead-bismuth in the lead-bismuth calibration container. Based on the effective cross-sectional area inside the lead-bismuth calibration container Calculate the hydrostatic pressure of lead-bismuth liquid phase in the lead-bismuth calibration vessel. ; Obtain the real-time gas pressure inside the lead-bismuth calibration vessel Correction of lead-bismuth liquid phase hydrostatic pressure ; Obtain the lead-bismuth density at the current temperature Calculate the actual lead-bismuth liquid level ;

[0026] Step 2.5: Calculate the error between the actual lead-bismuth liquid level and the current liquid level measuring point. If the error exceeds the allowable range, adjust the position of the lead-bismuth liquid level switch through the sliding rail mounting base and return to step 2.3.

[0027] If the error is within the allowable range, the lead-bismuth level switch is positioned to the next level measuring point via the sliding rail mounting base, and the process returns to step 2.3.

[0028] If the calibration of all liquid level measuring points has been completed, the lead and bismuth in the lead and bismuth storage tank will be heated to the next set of temperature points through the heating system, and then return to step 2.2;

[0029] The experiment ended after the lead-bismuth level switch was calibrated at all temperature points.

[0030] Furthermore, after completing the calibration experiments of the two sets of level gauges and the lead-bismuth level switch, a verification experiment was conducted on the stability of the lead-bismuth level switch under extreme working conditions. Cyclic calibration was carried out at a specified temperature. Through repeated triggering and deactivation tests, the response characteristics of the lead-bismuth level switch under long-term high-temperature environment were recorded to verify its measurement repeatability and operational reliability.

[0031] The beneficial effects of this invention are as follows:

[0032] This invention provides an experimental system and method for lead-bismuth level gauges. It verifies the accuracy of the lead-bismuth level gauge through benchmark calibration and cross-validation. Based on weighing-based hydrostatic pressure conversion, it combines hardware position fine-tuning and software parameter correction to complete the calibration of the lead-bismuth level switch. Furthermore, the stability of the level switch can be verified through cyclic testing at a specified temperature. This invention is adapted to the high-temperature, high-density, and easily oxidized characteristics of lead-bismuth. It clearly defines the steps for temperature setting, level calibration, error judgment, adjustment, and re-verification, and is highly reproducible, providing a solution for the large-scale calibration of lead-bismuth level measurement equipment. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of an experimental system for a lead-bismuth level gauge according to the present invention.

[0034] Figure 2 This is a schematic diagram of the lead-bismuth calibration vessel in this invention.

[0035] Figure 3 This is a schematic diagram of the measuring points of the heat tracing system for the lead-bismuth storage tank in an embodiment of the present invention.

[0036] Figure 4 This is a schematic diagram of the measuring points of the lead-bismuth calibration tank heat tracing system in an embodiment of the present invention.

[0037] Figure 5 This is a schematic diagram of the thermal parameter measuring points of the lead-bismuth calibration vessel in an embodiment of the present invention.

[0038] Figure 6 This is a schematic diagram of the measuring points during the calibration test of the lead-bismuth level gauge in an embodiment of the present invention.

[0039] Figure 7This is a schematic diagram of the measuring points during the calibration test of the lead-bismuth level switch in an embodiment of the present invention.

[0040] Figure 8 This is a schematic diagram of the measuring points during a specific operating condition test of the lead-bismuth level switch in an embodiment of the present invention.

[0041] Figure 9 This is a schematic diagram of the experimental system for a lead-bismuth level gauge in an embodiment of the present invention. Detailed Implementation

[0042] The present invention will now be further described with reference to the accompanying drawings.

[0043] like Figure 1 As shown, the present invention provides a lead-bismuth level gauge experimental system, including a lead-bismuth calibration tank 1, a lead-bismuth storage tank 2, a lead-bismuth level gauge 3, a lead-bismuth calibration source 4, an argon gas supply device 5, a test system monitoring camera 6, calibration tank electrical contacts 7, calibration tank lead-bismuth temperature measuring points 8, calibration tank argon gas interface 9, calibration tank lead-bismuth top-filling pipe interface 10, calibration tank lead-bismuth reflux pipe interface 11, calibration tank lead-bismuth reflux argon gas supply pipe 12, calibration tank lead-bismuth top-filling argon gas supply pipe 13, automatic gas supply pressure regulating controller 14, storage tank gas phase pressure measuring point 15, calibration tank wall temperature measuring point 16, calibration tank gas phase temperature measuring point 17, calibration tank gas phase pressure measuring point 18, storage tank lead-bismuth drain hole 19, heating system 20, and filter device 21.

[0044] like Figure 2 As shown, the lead-bismuth calibration tank 1 includes an outer protective shell 101, an insulation layer 102, a return pipe flange 103, a top filling pipe flange 104, an argon inlet / outlet flange 105, a lead-bismuth level switch 106, a lead-bismuth level gauge outer sleeve 107, a pressure sensor mounting hole 108, a level measuring instrument mounting hole 109, a slide rail mounting base 110, and a high-precision scale 111.

[0045] Inside the lead-bismuth calibration tank 1, along the tank's axis, are installed a lead-bismuth calibration source 4, a lead-bismuth level switch 106, and two sets of lead-bismuth level gauges 3. A weighing sensor is located at the bottom of the lead-bismuth calibration tank 1. The lead-bismuth level switch 106 is installed inside the lead-bismuth calibration tank 1 via a sliding rail mounting base 110 and is connected to the weighing sensor. A high-precision scale 111 is located on the outside of the sliding rail mounting base 110, and the high-precision scale 111 is aligned with the measurement reference of the lead-bismuth calibration source 4. The lead-bismuth storage tank 2 is connected to the lead-bismuth calibration tank 1 via a filling pipe and a return pipe. A heating system 20 covers the lead-bismuth calibration tank 1, the lead-bismuth storage tank 2, and all connecting pipes to maintain the lead-bismuth liquid state. A protective gas supply system is connected to the lead-bismuth calibration tank 1 and the lead-bismuth storage tank 2 via pipelines. The protective gas supply system is equipped with a gas supply pressure regulating controller 14 to regulate the liquid level in the lead-bismuth calibration tank 1 and prevent lead-bismuth oxidation. The bottom of the lead-bismuth calibration vessel 1 is a hemispherical chamber. The return pipe is connected to the lowest point of the bottom of the lead-bismuth calibration vessel 1, and the filling pipe is connected to the bottom of the lead-bismuth calibration vessel 1, but its position is higher than the connection point of the return pipe. The filling pipe is equipped with a filter device 21; the bottom of the lead-bismuth storage tank 2 is equipped with a lead-bismuth drain hole 19. The outer layer of the lead-bismuth calibration vessel 1 is an insulation layer, and the inner layer is a pressure-bearing cavity.

[0046] A test method for lead-bismuth level gauges includes calibration experiments for two sets of lead-bismuth level gauges 3:

[0047] Step 1.1: Set multiple temperature points and liquid level measuring points, sorted from low to high; use the heating system 20 to heat the lead and bismuth in the lead and bismuth storage tank 2 to the first temperature point and maintain a stable temperature;

[0048] Step 1.2: Using lead-bismuth calibration source 4 as a reference, adjust the lead-bismuth liquid level in lead-bismuth calibration tank 1 to the first liquid level measuring point through the protective gas supply system;

[0049] Step 1.3: Using the two sets of lead-bismuth level gauges 3 as a benchmark, conduct mutual verification, calculate the absolute error of the measured value of the lead-bismuth level gauge 3 at the current level measuring point relative to the lead-bismuth calibration source 4, and the relative error relative to the measured value of the other set of lead-bismuth level gauges 3;

[0050] Step 1.4: If the absolute or relative error exceeds the allowable range, adjust the installation position of the two sets of lead-bismuth level gauges 3 and return to step 1.3;

[0051] If both the absolute error and the relative error are within the allowable range, adjust the lead-bismuth liquid level in the lead-bismuth calibration tank 1 to the next liquid level measuring point through the protective gas supply system, and return to step 1.3;

[0052] If the calibration of all liquid level measuring points has been completed, the lead and bismuth in the lead and bismuth storage tank 2 will be heated to the next set of temperature points through the heating system 20, and the process will return to step 1.2.

[0053] After calibrating the two sets of lead-bismuth level gauges 3 at all temperature points, the calibration experiment of the lead-bismuth level switch 106 was carried out:

[0054] Step 2.1: Heat the lead and bismuth in the lead and bismuth storage tank 2 to the first temperature point using the heating system 20, and maintain the temperature stability;

[0055] Step 2.2: Position the lead-bismuth level switch 106 to the first level measuring point using the slide rail mounting base 110;

[0056] Step 2.3: Adjust the lead-bismuth level in the lead-bismuth calibration tank 1 through the protective gas supply system until the lead-bismuth level switch 106 is triggered;

[0057] Step 2.4: Obtain the measurement value of the weighing sensor at the bottom of the lead-bismuth calibration container 1, subtract the weight of the lead-bismuth calibration container 1 and the pipeline accessories, and obtain the net weight of lead-bismuth in the lead-bismuth calibration container 1. According to the effective cross-sectional area inside lead-bismuth calibration container 1 Calculate the hydrostatic pressure of lead-bismuth liquid phase in lead-bismuth calibration vessel 1. ; Obtain the real-time gas pressure inside lead-bismuth calibration vessel 1 Correction of lead-bismuth liquid phase hydrostatic pressure ; Obtain the lead-bismuth density at the current temperature Calculate the actual lead-bismuth liquid level ;

[0058] Step 2.5: Calculate the error between the actual lead-bismuth liquid level and the current liquid level measuring point. If the error exceeds the allowable range, adjust the position of the lead-bismuth liquid level switch 106 through the sliding rail mounting base 110 and return to step 2.3.

[0059] If the error is within the allowable range, the lead-bismuth level switch 106 is positioned to the next level measuring point via the slide rail mounting base 110, and the process returns to step 2.3.

[0060] If the calibration of all liquid level measuring points has been completed, the lead and bismuth in the lead and bismuth storage tank 2 will be heated to the next set of temperature points through the heating system 20, and the process will return to step 2.2.

[0061] After completing the calibration of the lead-bismuth level switch 106 at all temperature points, a verification experiment was conducted on the stability of the lead-bismuth level switch 106 under extreme operating conditions. Cyclic calibration was carried out at a specified temperature. Through repeated triggering and deactivation tests, the response characteristics of the lead-bismuth level switch 106 under long-term high-temperature environment were recorded to verify its measurement repeatability and operational reliability.

[0062] Example 1:

[0063] This embodiment provides a lead-bismuth level gauge testing system, which can be used to complete calibration tests of lead-bismuth level gauges, calibration tests of lead-bismuth level switches, and specific operating condition tests of lead-bismuth level switches. An auxiliary system, including a heating system, valve system, filtration system, argon gas supply system, vacuum system, measurement system, data acquisition system, and PLC system, is used to complete the measurement and analysis of specified test parameters.

[0064] The lead-bismuth calibration tank 1 provided in this embodiment is a comprehensive test device specifically designed for the calibration of lead-bismuth level gauges and level switches, as well as for testing under specific operating conditions. It is manufactured using S31608 material. The tank body adopts a multi-layer structure design, including an outer protective shell 101, an insulation layer 102, and an internal pressure-bearing chamber. The pressure-bearing chamber is made of corrosion-resistant 316L stainless steel and is covered with aluminum silicate insulation material to maintain stable medium temperature. The bottom is welded to the hemispherical chamber. The return pipe flange 103 is installed at the lowest point, and the top filling pipe flange 104 is positioned slightly higher than the lowest point. Argon gas inlet and outlet flanges 105 are installed at the upper end of the cylindrical section of the calibration tank, and lead-bismuth top filling and return pipe flanges are installed at the lower hemispherical section. The lead-bismuth calibration tank is equipped with two lead-bismuth level gauges 3, one lead-bismuth level gauge calibration source 4, and a lead-bismuth level switch 106 along the tank axis. The lead-bismuth level switch 106 has a built-in internal signal processing module and a static pressure conversion and threshold determination unit. The lead-bismuth level switch 106 is fixed by a slide rail mounting base 110 at the level measuring instrument mounting hole 109 and can move freely along the tank axis. A high-precision scale 111 is set on the outside of the movement path. The scale is precisely aligned with the measurement reference of the lead-bismuth calibration source 4 to achieve rapid positioning and precise fixing of the level mark point under different calibration requirements. The switch body is isolated from the lead-bismuth medium in the tank by a 316L material isolation sleeve to avoid the influence of strong corrosion. Its signal input terminal is connected to an external high-temperature resistant weighing sensor arranged at the support at the bottom of the calibration tank through a high-temperature resistant shielded cable.

[0065] The bottom external high-temperature resistant weighing sensor collects the simulated total weight signal of the calibration tank in real time and transmits the signal to the internal signal processing module of the lead-bismuth level switch 106. This module performs initial filtering and amplification of the weight signal. The pre-processed signal is transmitted to the static pressure conversion and threshold determination unit. This unit calls the pre-stored tank self-weight and pipeline accessory weight parameters to calculate the net weight G of lead-bismuth in the tank. Combined with the effective cross-sectional area of ​​the calibration tank, the liquid phase static pressure is calculated. Simultaneously, the real-time gas phase pressure of the calibration tank gas phase pressure measuring point 18 is received and corrected to obtain the true static pressure value. Then, the lead-bismuth density is corrected according to the real-time temperature data of the calibration tank lead-bismuth temperature measuring point 8. The current liquid level height is calculated by formula. Finally, the calculated liquid level is compared with the preset threshold, and the liquid level trigger or release switch signal is output.

[0066] The lead-bismuth storage tank 2 is used to store and circulate the lead-bismuth medium, and works with a heating system to maintain the lead-bismuth liquid state; the argon gas supply system precisely adjusts the liquid level in the calibration tank through a gas lift method, while isolating oxygen to prevent lead-bismuth oxidation; the measurement system consists of lead-bismuth temperature measuring points in the calibration tank, gas phase pressure measuring points in the storage tank, and gas phase pressure measuring points in the calibration tank. The collected data is used for temperature compensation and pressure correction during the calibration process; the 24-bit information acquisition system stores the calibration data in real time, the PLC system automatically controls the calibration temperature and liquid level adjustment, and the vacuum system ensures the purity of the argon environment through a dual-channel vacuum design.

[0067] This embodiment provides three independent but related calibration test procedures:

[0068] Lead-bismuth level gauge calibration test: To verify the accuracy of level gauges, a single calibration source was used as the metrological reference to independently calibrate two level gauges to be calibrated. Cross-validation was performed using measurement data from the two calibrated level gauges to eliminate systematic errors that might be introduced by a single reference. Multiple sets of temperature and level measurement points were set up to cover the entire operating range of the level gauges, enabling accuracy verification under different operating conditions and ensuring the reliability of the measurement results.

[0069] Calibration test of lead-bismuth level switch: Addressing the calibration requirements of the level switch trigger threshold, this test utilizes a weighing-based hydrostatic pressure conversion principle to convert the collected weight signal into the actual liquid level height, avoiding corrosion issues caused by direct contact between the sensor and the lead-bismuth medium. The switch installation position is fine-tuned using a sliding rail base to eliminate installation misalignment. Furthermore, by correcting the density compensation coefficient and threshold offset, errors caused by temperature and pressure changes in the conversion results are compensated for, thus achieving precise calibration of the switch trigger and release thresholds.

[0070] Lead-bismuth level switch specific operating condition test: To verify the stability of level switches under extreme operating conditions, cyclic calibration is carried out at a specified temperature. Through repeated triggering and deactivation tests, the response characteristics of the switch under long-term high-temperature environment are recorded to verify its measurement repeatability and operational reliability, ensuring that it meets the usage requirements of actual application scenarios.

[0071] The specific implementation steps are as follows:

[0072] 1. Preparation before the experiment

[0073] Check the equipment installation status: ensure that the calibration source, level gauge, and level switch are securely installed, the sensor wiring is normal, and the sliding base moves smoothly; turn on the ventilation equipment of the test site to ensure operational safety; start the power supply and heating system, heat the lead bismuth in the storage tank to a liquid state, then turn off the heating system and maintain the heating mode; perform two vacuuming operations on the system, maintaining the preset time after each vacuuming to remove residual gas; open the argon gas supply valve to fill the chamber with lead bismuth until the lead bismuth in the calibration tank reaches the initial liquid level, and record the initial pressure of the storage tank.

[0074] like Figure 3 The image shows the measuring points of the heat tracing system for the lead-bismuth storage tank in this embodiment. Figure 4 The image shows the measuring points of the heat tracing system for the lead-bismuth calibration tank in this embodiment. Figure 3 and Figure 4 The naming rules for measurement points are as follows:

[0075] The first digit indicates the temperature measuring point of the heat tracing system, uniformly represented as H; the second digit indicates the different systems, with lead-bismuth storage tanks represented as S and lead-bismuth calibration tubes represented as C. The numerical digits indicate the measuring point order of the unified equipment location, sorted according to Arabic numerals.

[0076] like Figure 5 The figures shown are the thermal parameter measuring points of the lead-bismuth calibration vessel in this embodiment. The naming rules are as follows:

[0077] The first digit indicates the measurement location, i.e., the lead-bismuth calibration vessel, C; the second digit indicates the medium of the physical quantity to be measured, L for liquid lead-bismuth, G for gaseous argon, and W for the wall surface; the third digit indicates the physical quantity to be measured, P for pressure and T for temperature; the Arabic numerals are the sequential numbering of the same physical quantity at different measurement points in the same medium.

[0078] 2. Calibration test of lead-bismuth level gauge

[0079] a. Temperature setting: Set eight preset temperature points. Through the coordinated action of the heating system and the heat tracing system, the lead and bismuth are heated to the first preset temperature point. After the temperature is stabilized, the liquid level calibration is carried out.

[0080] b. Liquid level calibration: such as Figure 6 The image shows the measuring points in the calibration test of the lead-bismuth level gauge. The calibration was carried out for eleven sets of liquid level conditions, including three single-temperature liquid level measuring points (T#-ACL-01 to T#-ACL-03), eight constant-level variable-temperature measuring points (T#-ACL-04 to T#-ACL-11), and two verification measuring points (L1-ACT-0# and L2-ACT-0#). The liquid level in the calibration tank was adjusted by the argon gas supply system and slowly rose to each preset measuring point. Data was recorded after the liquid level stabilized.

[0081] c. Calibration process: Using lead-bismuth calibration source 4 as the metrological reference, record the measured values ​​of the two level gauges at each measuring point to complete the reference calibration; then, using the measured values ​​of the two calibrated level gauges as a reference, conduct mutual verification and record the deviation of the two sets of measurement data.

[0082] d. Error judgment and adjustment: Calculate the absolute error and relative error of each measuring point. If the error exceeds the allowable range, fine-tune the installation position of the level gauge, re-collect data and calculate the error until the error meets the standard.

[0083] e. Temperature switching: After the calibration of a single temperature point is completed, the lead bismuth in the calibration vessel is refluxed to the storage tank by argon gas, and the temperature is switched to the next temperature point in order from high to low. The above liquid level calibration process is repeated.

[0084] 3. Calibration test of lead-bismuth level switch

[0085] a. Temperature setting: Use eight sets of temperature points calibrated by the lead-bismuth level gauge. After each set of temperatures stabilizes, perform level calibration.

[0086] b. Liquid level calibration: such as Figure 7 The diagram shows the measuring points in the calibration test of the lead-bismuth level switch. Calibration was carried out for six sets of liquid level conditions, including six single-temperature level measuring points (T#-BCL-01 to T#-BCL-06) and three constant-level variable-temperature measuring points (L1-BCT-0# to L3-BCT-0#). The level switch was positioned to each preset measuring point using a sliding rail mounting base to ensure that the switch measurement reference and the measuring point position were consistent.

[0087] c. Calibration Process: The high-temperature resistant weighing sensor at the bottom of the tank is activated to collect a simulated signal of the total weight of the calibration tank. The signal is transmitted through a shielded cable to the signal processing module inside the level switch, where initial filtering and amplification are performed sequentially. The pre-processed signal is then transmitted to the static pressure conversion threshold determination unit, which calculates the liquid level height according to the following logic:

[0088] (1) Call the pre-stored tank weight and pipeline accessory weight parameters, deduct them from the total weight, and obtain the net weight of lead and bismuth inside the tank. ;

[0089] (2) Calculate the liquid phase static pressure by combining the pre-stored effective cross-sectional area S of the calibration tank. ;

[0090] (3) Simultaneously receive the real-time gas phase pressure of the calibration tank gas phase pressure measuring point. Correction yields the true static pressure value. ;

[0091] (4) Based on the real-time temperature data of the lead-bismuth temperature measuring point in the calibration tank, call the pre-stored density correction parameters to obtain the lead-bismuth density at the current temperature. ;

[0092] (5) Through the formula The current liquid level is calculated, compared with a preset threshold, and a liquid level trigger or deactivation switch signal is output.

[0093] d. Signal Processing and Error Judgment: The switch signal is transmitted to an external signal processing module. After secondary filtering and amplification, it is output in two paths. One path is connected to the PLC switch input module to record the calibration source standard liquid level value and the actual measured liquid level value of the switch when the switch is triggered or released. A red indicator light illuminates when the switch is triggered, and a green indicator light illuminates when the switch is released. The other path is connected to a 24-bit information acquisition board to upload data to a computer via software such as LabVIEW. The absolute and relative errors of each measuring point are calculated. If the error exceeds the allowable range, the axial position of the liquid level switch can be finely adjusted using the sliding rail mounting base to eliminate installation misalignment. Alternatively, the liquid level switch's built-in storage unit can be connected to a host computer to correct the lead-bismuth density temperature compensation coefficient or the liquid level threshold offset to offset the working condition adaptation deviation. After adjustment, the measuring point is recalibrated until the error meets the standard.

[0094] e. Temperature switching: After all liquid level measuring points are calibrated at a single temperature point, switch to the next temperature point and repeat the above liquid level calibration process.

[0095] 4. Specific operating condition test of lead-bismuth level switch

[0096] a. Temperature setting: Set a single specified temperature point, and after the heating system and heat tracing system work together to maintain a stable temperature, conduct cyclic testing;

[0097] b. Liquid level calibration: such as Figure 8 As shown, calibration was carried out for six sets of liquid level height conditions (measuring point numbers T#-CCL-01 to T#-CCL-06);

[0098] c. Calibration process: Repeat the signal acquisition, static pressure conversion, signal processing and error judgment process of the lead-bismuth level switch calibration test. Trigger and deactivate each set of measuring points in a cycle, record the level value at each trigger and deactivation, and calculate the repeatability error. If the repeatability error exceeds the allowable range, recalibrate the hardware position and correct the software parameters until the repeatability error meets the standard in the cycle test. The focus is on verifying the stability and reliability of the switch under the specified high temperature conditions.

[0099] 5. End of the experiment

[0100] After all calibration processes are completed, close the argon gas supply system's charging pipe and open the return gas supply pipe to return all the lead and bismuth in the calibration tank to the storage tank using argon gas pressure; close the heating system, power supply system, and all valves; organize the calibration data and generate a calibration report containing each temperature point and each measuring point, clarifying key indicators such as the measurement accuracy and repeatability error of the liquid level measuring equipment used in lead and bismuth environments.

[0101] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A lead bismuth level meter experimental system, characterized in that: The system includes a lead-bismuth calibration tank (1), a lead-bismuth storage tank (2), and an auxiliary support system. The lead-bismuth calibration tank (1) is equipped with a lead-bismuth calibration source (4), a lead-bismuth level switch (106), and two sets of lead-bismuth level gauges (3) along the tank axis. A weighing sensor is provided at the bottom of the lead-bismuth calibration tank (1). The lead-bismuth level switch (106) is installed in the lead-bismuth calibration tank (1) via a sliding rail mounting base (110). The lead-bismuth storage tank (2) is connected to the lead-bismuth calibration tank (1) via a pipeline. The auxiliary support system includes a heating system (20) and a protective gas supply system.

2. The experimental system of the lead bismuth level meter according to claim 1, characterized in that: The lead-bismuth level switch (106) is connected to the weighing sensor; the net weight of lead-bismuth in the lead-bismuth calibration tank (1) is calculated based on the measured value of the weighing sensor, the static pressure of lead-bismuth liquid phase in the lead-bismuth calibration tank (1) is calculated based on the effective cross-sectional area in the lead-bismuth calibration tank (1), and the calculated value of lead-bismuth liquid phase static pressure is corrected based on the real-time gas pressure in the lead-bismuth calibration tank (1); the actual lead-bismuth level is calculated based on the lead-bismuth density at the current temperature and the corrected lead-bismuth liquid phase static pressure; the actual lead-bismuth level is compared with the preset threshold, and the lead-bismuth level switch (106) is triggered.

3. The experimental system of the lead bismuth level meter according to claim 2, characterized in that: The lead-bismuth liquid level switch (106) has a built-in internal signal processing module and a static pressure conversion and threshold determination unit. The signal input terminal of the lead-bismuth liquid level switch (106) is connected to the weighing sensor through a high-temperature shielded cable. The weight signal collected by the weighing sensor is transmitted to the internal signal processing module for initial filtering and amplification, and then transmitted to the static pressure conversion and threshold determination unit to perform the calculation of the static pressure of the lead-bismuth liquid phase and the actual liquid level of lead-bismuth, and trigger the lead-bismuth liquid level switch (106) according to the preset threshold.

4. The lead-bismuth level gauge experimental system according to claim 1, characterized in that: The heat tracing system (20) covers the lead-bismuth calibration tank (1), the lead-bismuth storage tank (2), and all connecting pipes, and is used to maintain the lead-bismuth liquid state.

5. The lead-bismuth level gauge experimental system according to claim 1, characterized in that: The protective gas supply system is connected to the lead-bismuth calibration tank (1) and the lead-bismuth storage tank (2) respectively through pipelines. The protective gas supply system is equipped with a gas supply pressure regulating controller (14) to adjust the liquid level in the lead-bismuth calibration tank (1) and prevent lead-bismuth oxidation.

6. The lead-bismuth level gauge experimental system according to claim 1, characterized in that: The bottom of the lead-bismuth calibration tank (1) is a hemispherical chamber. The lead-bismuth storage tank (2) is connected to the lead-bismuth calibration tank (1) through a filling pipe and a return pipe. The return pipe is connected to the lowest point of the bottom of the lead-bismuth calibration tank (1). The filling pipe is connected to the bottom of the lead-bismuth calibration tank (1) and is positioned higher than the connection point of the return pipe. The filling pipe is equipped with a filter device (21).

7. The lead-bismuth level gauge experimental system according to claim 1, characterized in that: The lead-bismuth storage tank (2) is provided with a lead-bismuth drain hole (19) at the bottom; a high-precision scale (111) is provided on the outside of the sliding rail mounting base (110), and the high-precision scale (111) is aligned with the measurement reference of the lead-bismuth calibration source (4); the outer layer of the lead-bismuth calibration tank (1) is a heat insulation layer, and the inner layer is a pressure-bearing cavity; the protective gas supply system uses argon as the protective gas.

8. An experimental method using the lead-bismuth level gauge experimental system of claim 1, characterized in that: The calibration experiments included two sets of lead-bismuth level gauges (3): Step 1.1: Set multiple temperature points and liquid level measuring points, sorted from low to high; use the heating system (20) to heat the lead and bismuth in the lead and bismuth storage tank (2) to the first temperature point and maintain the temperature stability; Step 1.2: Using the lead-bismuth calibration source (4) as a reference, adjust the lead-bismuth liquid level in the lead-bismuth calibration tank (1) to the first liquid level measuring point through the protective gas supply system; Step 1.3: Using two sets of lead-bismuth level gauges (3) as a benchmark, perform mutual verification, calculate the absolute error of the measured value of the lead-bismuth level gauge (3) at the current level measuring point relative to the lead-bismuth calibration source (4), and the relative error relative to the measured value of the other set of lead-bismuth level gauges (3); Step 1.4: If the absolute error or relative error exceeds the allowable range, adjust the installation position of the two sets of lead-bismuth level gauges (3) and return to step 1.3; If both the absolute error and the relative error are within the allowable range, the lead-bismuth liquid level in the lead-bismuth calibration tank (1) is adjusted to the next liquid level measuring point through the protective gas supply system, and the process returns to step 1.3; If all liquid level measuring points have been calibrated, the lead and bismuth in the lead and bismuth storage tank (2) will be heated to the next set of temperature points through the heating system (20), and the process will return to step 1.

2. After completing the calibration of the two sets of lead-bismuth level gauges (3) at all temperature points, the experiment was terminated.

9. The experimental method for a lead-bismuth level gauge according to claim 8, characterized in that: After completing the calibration of the two sets of level gauges (3), the calibration experiment of the lead-bismuth level switch (106) was carried out: Step 2.1: Heat the lead bismuth in the lead bismuth storage tank (2) to the first temperature point using the heating system (20) and maintain the temperature stable; Step 2.2: Position the lead-bismuth level switch (106) to the first level measuring point using the slide rail mounting base (110); Step 2.3: Adjust the lead-bismuth level in the lead-bismuth calibration tank (1) through the protective gas supply system until the lead-bismuth level switch (106) is triggered. Step 2.4: Obtain the measured value of the weighing sensor at the bottom of the lead-bismuth calibration container (1), subtract the weight of the lead-bismuth calibration container (1) and pipeline accessories, and obtain the net weight of lead-bismuth in the lead-bismuth calibration container (1). According to the effective cross-sectional area inside the lead-bismuth calibration container (1) Calculate the hydrostatic pressure of the lead-bismuth liquid phase in the lead-bismuth calibration vessel (1). ; Obtain the real-time gas pressure inside the lead-bismuth calibration vessel (1) Correction of lead-bismuth liquid phase hydrostatic pressure ; Obtain the lead-bismuth density at the current temperature Calculate the actual lead-bismuth liquid level ; Step 2.5: Calculate the error between the actual lead-bismuth liquid level and the current liquid level measuring point. If the error exceeds the allowable range, adjust the position of the lead-bismuth liquid level switch (106) through the sliding rail mounting base (110) and return to step 2.

3. If the error is within the allowable range, the lead-bismuth level switch (106) is positioned to the next level measuring point via the slide rail mounting base (110), and the process returns to step 2.3; If all liquid level measuring points have been calibrated, the lead and bismuth in the lead and bismuth storage tank (2) will be heated to the next set of temperature points through the heating system (20), and the process will return to step 2.

2. After completing the calibration of the lead-bismuth level switch (106) at all temperature points, the experiment was terminated.

10. The experimental method for a lead-bismuth level gauge according to claim 9, characterized in that: After completing the calibration of the two sets of level gauges (3) and the calibration experiment of the lead-bismuth level switch (106), a verification experiment was carried out on the stability of the lead-bismuth level switch (106) under extreme working conditions. Cyclic calibration was carried out at a specified temperature. Through repeated triggering and deactivation tests, the response characteristics of the lead-bismuth level switch (106) under long-term high temperature environment were recorded to verify its measurement repeatability and working reliability.

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