A method for verifying performance and reliability of high-temperature and high-pressure liquid level instrument

Abstract

The present application belongs to the technical field of thermal control instrument, and particularly relates to a method for verifying the performance and reliability of high-temperature and high-pressure liquid level instrument, comprising the following steps: Step 1: normal-temperature and high-pressure static sealing test; and Step 2: high-temperature and high-pressure saturated steam environment liquid level test. The present application has the beneficial effect that the method is divided into two parts, i.e. normal-temperature and high-pressure static sealing test and high-temperature and high-pressure saturated steam environment liquid level test. The normal-temperature and high-pressure static sealing test is mainly used to test the sealing characteristics of the instrument at normal temperature and below 9 MPa, and the method can find the sealing structure failure of the instrument in advance and improve the design.

Description

Technical Field

[0001] This invention belongs to the field of thermal control instrument technology, specifically relating to a method for verifying the performance and reliability of a high-temperature and high-pressure liquid level instrument. Background Technology

[0002] High-temperature, high-pressure sealed-compensation guided wave radar level gauges are emerging high-end industrial automation level instruments based on guided wave radar principles and sealed steam compensation technology. They are widely used in the gas-liquid two-phase environment measurement of the secondary loop in nuclear power plants, such as the level measurement of high-pressure heaters, low-pressure heaters, steam-water separator reheater condensate tanks, and condensers. Especially in gas-liquid two-phase saturated steam environments such as steam-water separator reheater condensate tanks and high-pressure heater levels, the guided wave radar level gauge measurement components possess the following two key technologies: First, the measurement components should have stable measurement compensation and anti-condensation design. Second, the measurement components should be able to operate long-term in high-temperature, high-pressure, high-frequency vibration, and diverse gas-liquid two-phase saturated steam environments, mainly reflected in the structural design and material selection of the measurement components.

[0003] Due to design flaws, existing guided wave radar level gauges used in nuclear power plants suffer from problems such as sealing structure leakage, unstable automatic steam compensation, and broken support components. Sealing structure leakage refers to the failure of the instrument's sealing components due to thermal aging, high-frequency vibration of the gas-liquid two-phase system, thermal corrosion, and seepage. Unstable steam compensation indicates that the instrument's steam compensation software and hardware are poorly designed and easily affected by external environmental interference, leading to distorted measurement values. Broken support components occur in saturated steam environments where the expansion coefficients of the support material differ from those of the surrounding metal, and are subject to significant impacts from stable power operation, power variation operation, and flash evaporation conditions. Furthermore, the added disturbance from turbine extraction steam changes further affects the lifespan of the support components. These problems are key issues with high-temperature, high-pressure guided wave radar level gauges, hindering their widespread application in the secondary loop of nuclear power plants. Summary of the Invention

[0004] The purpose of this invention is to provide a method for verifying the performance and reliability of a high-temperature and high-pressure liquid level instrument. The method involves creating a high-temperature and high-pressure saturated steam condition on a test device, similar to that of the secondary loop in a nuclear power plant, to comprehensively verify the performance of the instrument and identify potential key issues in its application.

[0005] The technical solution of the present invention is as follows: a method for verifying the performance and reliability of a high-temperature and high-pressure liquid level instrument, comprising the following steps:

[0006] Step 1: Static sealing test under normal temperature and high pressure;

[0007] Step 2: High temperature and high pressure saturated steam environment liquid level test.

[0008] Step 1 involves conducting a static sealing test on the instrument measurement component under normal temperature and high pressure to verify the performance of the sealing structure and material design of the instrument measurement component. The test temperature is normal temperature, the test medium is water, and the device is pressurized using a pressure pump. The measurement component is then installed into the test device and sealed with a flange.

[0009] Step 1 includes the following:

[0010] Step 11: Increase the pressure of the device to 2MPa, maintain the pressure for 4 hours, and perform a visual inspection to confirm whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the nuts of the measuring component. The qualified standard for visual inspection is that the measuring component and the sealing flange do not leak or have any water seepage.

[0011] Step 12: Increase the pressure of the device to 5MPa, maintain the pressure for 8 hours, and perform a visual inspection to confirm whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The qualified standard for visual inspection is that the measuring component and the sealing flange do not leak or have any water seepage.

[0012] Step 13: Increase the pressure of the device to 8.5 MPa, maintain the pressure for 36 hours, and perform a visual inspection to confirm whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The visual inspection qualification standard is that there is no leakage of the measuring component and the sealing flange, and no water leakage of the sealing weld and the coaxial nut. After disassembling and inspecting the sealing component, the qualification standard is that there are no water leakage marks on the first thermal insulation seal and the sealing ring of the measuring component, and the graphite gasket does not leak.

[0013] Step 14: Increase the pressure of the device to 9MPa, maintain the pressure for 48 hours, and perform a visual inspection to confirm whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The qualified standard for the visual inspection is that the measuring component and the sealing flange do not leak or have any water seepage. After the visual inspection, disassemble the sealing component for inspection. The qualified standard for the inspection is that the first thermal insulation seal and the sealing ring of the measuring component have no water seepage marks, and the graphite gasket does not leak.

[0014] In step 2, the test medium is water and water vapor. The test device is used to simulate the high temperature and high pressure saturated steam conditions, continuous power change conditions, and liquid level changes in the secondary loop of a nuclear power plant. The test is used to assess the measurement accuracy of the instruments, the sealing performance of the instruments, and the high temperature resistance of the instrument sealing materials.

[0015] Step 2 includes the following:

[0016] Step 21: Testing the sealing and compensation performance of a fixed liquid level under high temperature and high pressure.

[0017] The liquid level in the fixed test apparatus is used to test the sealing and automatic compensation performance of the instruments under different high temperature and high pressure environments.

[0018] Step 22: 150℃ Dynamic Liquid Level Sealing and Automatic Compensation Performance Test

[0019] The device was raised to a saturated steam pressure environment of 150℃, and the liquid level of the device was adjusted by a pressure pump. The sealing and automatic compensation performance of the instrument under this temperature and pressure were tested.

[0020] Step 23: 220℃ dynamic liquid level sealing and automatic compensation performance test;

[0021] Step 24: 260℃ dynamic liquid level sealing and automatic compensation performance test;

[0022] Step 25: Static liquid level compensation performance test under saturated steam environment at 110℃~260℃

[0023] The liquid level in the fixed device is maintained at 50% of the instrument's measuring range. By continuously adjusting the device's operating conditions, the instrument's compensation performance under different operating conditions is tested. The instrument accuracy is tested in saturated steam environments at 110℃, 150℃, 220℃, and 260℃, and the deviation from the device's reference instrument is recorded. The test deviation must not exceed 3%.

[0024] Step 26: Dynamic liquid level compensation performance test under saturated steam environment of 110℃~260℃

[0025] The liquid level of the continuous adjustment device is tested by measuring the operating conditions of the device under different conditions. The instrument accuracy is tested in saturated steam environments at 110℃, 150℃, 220℃, and 260℃, and the deviation from the device's reference instrument is recorded. The test deviation needs to be determined based on the actual liquid level adjustment accuracy.

[0026] Step 22 includes the following:

[0027] Step 221: Sealing Test

[0028] The test lasts for more than 36 hours to confirm whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The visual inspection qualification standard is that the measuring component and the sealing flange do not leak or have water seepage. After the visual inspection, the sealing component is disassembled and inspected. The inspection qualification standard is that the first thermal insulation seal and the sealing ring of the measuring component have no water seepage marks, and the graphite gasket does not leak.

[0029] Step 222: Automatic Compensation Test

[0030] With automatic instrument compensation, the instrument's measured values ​​at 0%, 20%, 40%, 60%, 80%, and 100% of the liquid level are recorded, along with the deviation from the device's reference instrument. Under static conditions, the liquid level deviation should not exceed 3%.

[0031] Step 223: Turn off the automatic compensation test and record the instrument's measured values ​​at 0%, 20%, 40%, 60%, 80%, and 100% of the liquid level, as well as the deviation of the device's reference instrument.

[0032] Step 23 includes the following:

[0033] Step 231: Sealing Test

[0034] The test lasts for more than 36 hours to confirm whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The visual inspection qualification standard is that the measuring component and the sealing flange do not leak or have water seepage. After the visual inspection, the sealing component is disassembled and inspected. The inspection qualification standard is that the first thermal insulation seal and the sealing ring of the measuring component have no water seepage marks, and the graphite gasket does not leak.

[0035] Step 232: Automatic Compensation Test

[0036] With automatic instrument compensation, the instrument's measured values ​​at 0%, 20%, 40%, 60%, 80%, and 100% of the liquid level are recorded, along with the deviation from the device's reference instrument. Under static conditions, the liquid level deviation should not exceed 3%.

[0037] Step 233: Turn off the automatic compensation test and record the instrument's measured values ​​at 0%, 20%, 40%, 60%, 80%, and 100% of the liquid level, as well as the deviation of the device's reference instrument.

[0038] Step 24 includes the following:

[0039] Step 241: Sealing Test

[0040] The test lasts for more than 36 hours to confirm whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The visual inspection qualification standard is that the measuring component and the sealing flange do not leak or have water seepage. After the visual inspection, the sealing component is disassembled and inspected. The inspection qualification standard is that the first thermal insulation seal and the sealing ring of the measuring component have no water seepage marks, and the graphite gasket does not leak.

[0041] Step 242: Instrument Automatic Compensation Test

[0042] With automatic instrument compensation, the instrument's measured values ​​at 0%, 20%, 40%, 60%, 80%, and 100% of the liquid level are recorded, along with the deviation from the device's reference instrument. Under static conditions, the liquid level deviation should not exceed 3%.

[0043] Step 243: Perform an automatic compensation test on the instrument and record the instrument's measured values ​​and the deviation of the device's reference instrument at liquid levels of 0%, 20%, 40%, 60%, 80%, and 100%.

[0044] The beneficial effects of this invention are as follows: This method consists of two parts: a static sealing test at room temperature and high pressure, and a liquid level test in a high-temperature, high-pressure saturated steam environment. The static sealing test at room temperature and high pressure is mainly used to test the sealing characteristics of the instrument at room temperature and below 9MPa. This method can identify instrument sealing structure faults in advance and improve the design. The liquid level test in a high-temperature, high-pressure saturated steam environment consists of three parts: first, under saturated steam conditions, verifying the sealing performance and measurement accuracy of the instrument at a fixed liquid level; second, verifying the sealing performance, measurement accuracy, and equipment reliability of the instrument under fixed saturated conditions of 150℃, 220℃, and 260℃ respectively; and third, testing the sealing performance, measurement accuracy, and equipment reliability of the instrument under both fixed and dynamic liquid levels under dynamic saturated conditions of 110℃~260℃. This method can identify sealing structure and measurement compensation faults of the instrument under high-temperature and high-pressure saturated conditions in advance and carry out effective improvement designs, solving the key problems of inaccurate steam compensation and instrument leakage under saturated conditions. Instruments validated by this method can ensure that the measuring components will not leak, thus preventing instrument unavailability, and will not cause poor insulation or heat dissipation performance, leading to thermal aging of the instrument processor. They are suitable for measuring the liquid level of high-pressure heaters, low-pressure heaters, condensers, and steam-water separator reheaters in the secondary loop of nuclear power plants, and can provide accurate liquid level measurement data for the unit under various loop operating conditions (negative pressure, atmospheric pressure, high pressure, and high and low temperature environments) and changes in operating conditions. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the static sealing test method and standard under normal temperature and high pressure.

[0046] Figure 2 This is a schematic diagram of the liquid level testing method and standard for high-temperature, high-pressure saturated steam environments. Detailed Implementation

[0047] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] The present invention provides a method for verifying the performance and reliability of a high-temperature and high-pressure level gauge. The measurement component used is "A High-Temperature and High-Pressure Sealed Compensation Guided Wave Radar Level Gauge Measurement Component" (Patent No. ZL 2023 10701981.1). A series of high-temperature and high-pressure sealing and insulation tests and long-cycle tests under harsh operating conditions in the secondary loop of a nuclear power plant were completed to verify the reliability of the design and manufacture of the measurement component, and to summarize the relevant verification methods and standards.

[0049] A method for verifying the performance and reliability of a high-temperature and high-pressure liquid level instrument includes the following steps:

[0050] Step 1: Static sealing test under normal temperature and high pressure

[0051] A static sealing test at room temperature and high pressure was conducted on the instrument measuring components to verify the performance of the sealing structure and material design. This test requires designing a static sealing test apparatus based on the shape of the measuring components. The test temperature is room temperature, the rated pressure bearing capacity of the apparatus should be 10 MPa or higher, and the test medium is water. A pressure pump is used to pressurize the apparatus. The measuring components are then installed into the test apparatus and sealed with flanges. Based on testing experience, the measuring components are arranged for the following tests:

[0052] Step 11: Increase the pressure of the device to 2 MPa, maintain the pressure for 4 hours, and perform a visual inspection. Observe whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the nuts of the measuring component. The visual inspection qualification standard is that there is no leakage or water seepage from the measuring component and the sealing flange.

[0053] Step 12: Increase the pressure of the device to 5 MPa, maintain the pressure for 8 hours, and perform a visual inspection. Observe whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The visual inspection qualification standard is that there is no leakage or water seepage from the measuring component and the sealing flange.

[0054] Step 13: Increase the pressure of the device to 8.5 MPa, maintain the pressure for 36 hours, and perform a visual inspection. Observe whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The acceptance criteria for the visual inspection are that there is no leakage from the measuring component and the sealing flange, and no water seepage from the sealing weld and coaxial nut. After disassembling and inspecting the sealing component, the acceptance criteria are that there are no water seepage marks on the first thermal insulation seal and the sealing ring of the measuring component, and the graphite gasket does not leak.

[0055] Step 14: Increase the pressure of the device to 9 MPa, maintain the pressure for 48 hours, and perform a visual inspection. Observe whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The acceptance standard for the visual inspection is that there is no leakage or water seepage in the measuring component and the sealing flange. After the visual inspection, disassemble the sealing component for detailed inspection. The acceptance standard for the detailed inspection is that there are no water seepage marks on the first thermal insulation seal and the sealing ring of the measuring component, and the graphite gasket does not leak.

[0056] Step 2: High-temperature, high-pressure saturated steam environment liquid level test

[0057] A high-temperature, high-pressure saturated steam condition liquid level measurement test device was used. The test medium was water and steam. The device simulated various high-temperature, high-pressure saturated steam conditions and continuous power variation conditions in the secondary loop of a nuclear power plant, along with liquid level changes, to test the measurement accuracy, sealing performance, and high-temperature resistance of the sealing materials of the instruments. This test required prior completion and passing of liquid level tests at room temperature and pressure. Based on testing experience, the measurement components were arranged for the following tests:

[0058] Step 21: Testing the sealing and compensation performance of a fixed liquid level under high temperature and high pressure.

[0059] The liquid level in the fixed test apparatus is used to test the sealing and automatic compensation performance of the instrument under different high temperature and high pressure environments.

[0060] Step 22: 150℃ Dynamic Liquid Level Sealing and Automatic Compensation Performance Test

[0061] The device was raised to a saturated steam pressure environment of 150℃, and the liquid level of the device was adjusted by a pressurization pump. The sealing and automatic compensation performance of the instruments under this temperature and pressure were tested. This operating condition can cover the operating conditions of the liquid level of the low-pressure heater in a nuclear power plant.

[0062] Step 221: Sealing Test

[0063] The entire test takes more than 36 hours, mainly observing whether there is water leakage on the flange face of the measuring component and device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The visual inspection qualification standard is that the measuring component and the sealing flange do not leak or have any water seepage. After the visual inspection, the sealing component is disassembled for detailed inspection. The detailed inspection qualification standard is that the first thermal insulation seal and the sealing ring of the measuring component have no water seepage marks, and the graphite gasket does not leak.

[0064] Step 222: Automatic Compensation Test

[0065] Under automatic instrument compensation, the instrument's measured values ​​at 0%, 20%, 40%, 60%, 80%, and 100% of the liquid level are recorded, along with the deviation of the device's reference instrument. Under static conditions, the liquid level deviation should not exceed 3%.

[0066] Step 223: Turn off the automatic compensation test and record the instrument's measured values ​​at 0%, 20%, 40%, 60%, 80%, and 100% of the liquid level, as well as the deviation of the device's reference instrument.

[0067] Step 23: 220℃ Dynamic Liquid Level Sealing and Automatic Compensation Performance Test

[0068] Step 231: Sealing Test

[0069] The entire test takes more than 36 hours, mainly observing whether there is water leakage on the flange face of the measuring component and device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The visual inspection qualification standard is that the measuring component and the sealing flange do not leak or have any water seepage. After the visual inspection, the sealing component is disassembled for detailed inspection. The detailed inspection qualification standard is that the first thermal insulation seal and the sealing ring of the measuring component have no water seepage marks, and the graphite gasket does not leak.

[0070] Step 232: Automatic Compensation Test

[0071] Under automatic instrument compensation, the instrument's measured values ​​at 0%, 20%, 40%, 60%, 80%, and 100% of the liquid level are recorded, along with the deviation of the device's reference instrument. Under static conditions, the liquid level deviation should not exceed 3%.

[0072] Step 233: Turn off the automatic compensation test and record the instrument's measured values ​​at 0%, 20%, 40%, 60%, 80%, and 100% of the liquid level, as well as the deviation of the device's reference instrument.

[0073] Step 24: 260℃ Dynamic Liquid Level Sealing and Automatic Compensation Performance Test

[0074] Step 241: Sealing Test

[0075] The entire test takes more than 36 hours, mainly observing whether there is water leakage on the flange face of the measuring component and device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The visual inspection qualification standard is that the measuring component and the sealing flange do not leak or have any water seepage. After the visual inspection, the sealing component is disassembled for detailed inspection. The detailed inspection qualification standard is that the first thermal insulation seal and the sealing ring of the measuring component have no water seepage marks, and the graphite gasket does not leak.

[0076] Step 242: Instrument Automatic Compensation Test

[0077] Under automatic instrument compensation, the instrument's measured values ​​at 0%, 20%, 40%, 60%, 80%, and 100% of the liquid level are recorded, along with the deviation of the device's reference instrument. Under static conditions, the liquid level deviation should not exceed 3%.

[0078] Step 243: Perform an automatic compensation test on the instrument and record the instrument's measured values ​​and the deviation of the device's reference instrument at liquid levels of 0%, 20%, 40%, 60%, 80%, and 100%.

[0079] Step 25: Static liquid level compensation performance test under saturated steam environment at 110℃~260℃

[0080] The liquid level of the fixed device is maintained at 50% of the instrument's measuring range. By continuously adjusting the device's operating conditions, the compensation performance of the instrument under different operating conditions is tested. The instrument accuracy of the device is tested in saturated steam environments at 110℃, 150℃, 220℃, and 260℃, and the deviation from the device's reference instrument is recorded. The test deviation should not exceed 3%.

[0081] Step 26: Dynamic liquid level compensation performance test under saturated steam environment of 110℃~260℃

[0082] The liquid level of the continuous adjustment device is tested by measuring the operating conditions of the device under different conditions. The instrument accuracy is tested in saturated steam environments at 110℃, 150℃, 220℃, and 260℃, and the deviation from the device's reference instrument is recorded. The test deviation needs to be determined based on the actual liquid level adjustment accuracy.

Claims

1. A method for verifying the performance and reliability of a high-temperature and high-pressure liquid level instrument, characterized in that, The steps include the following: Step 1: Static sealing test under normal temperature and high pressure; Step 1 involves conducting a static sealing test on the instrument measurement component under normal temperature and high pressure to verify the performance of the sealing structure and material design of the instrument measurement component. The test temperature is normal temperature, the test medium is water, and the device is pressurized using a pressure pump. The measurement component is then installed into the test device and sealed with a flange. Step 1 includes the following: Step 11: Increase the pressure of the device to 2MPa, maintain the pressure for 4 hours, and perform a visual inspection to confirm whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the nuts of the measuring component. The qualified standard for visual inspection is that the measuring component and the sealing flange do not leak or have any water seepage. Step 12: Increase the pressure of the device to 5MPa, maintain the pressure for 8 hours, and perform a visual inspection to confirm whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The qualified standard for visual inspection is that the measuring component and the sealing flange do not leak or have any water seepage. Step 13: Increase the pressure of the device to 8.5 MPa, maintain the pressure for 36 hours, and perform a visual inspection to confirm whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The visual inspection qualification standard is that there is no leakage of the measuring component and the sealing flange, and no water leakage of the sealing weld and the coaxial nut. After disassembling and inspecting the sealing component, the qualification standard is that there are no water leakage marks on the first thermal insulation seal and the sealing ring of the measuring component, and the graphite gasket does not leak. Step 14: Increase the pressure of the device to 9MPa, maintain the pressure for 48 hours, and perform a visual inspection to confirm whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The visual inspection qualification standard is that the measuring component and the sealing flange do not leak or have any water seepage. After the visual inspection, disassemble the sealing component for inspection. The inspection qualification standard is that the first thermal insulation seal and the sealing ring of the measuring component have no water seepage marks, and the graphite gasket does not leak. Step 2: High-temperature, high-pressure saturated steam environment liquid level test; In step 2, the test medium is water and water vapor. The test device is used to simulate the high temperature and high pressure saturated steam conditions, continuous power change conditions, and liquid level changes in the secondary loop of a nuclear power plant. The test instrument's measurement accuracy, instrument sealing performance, and high temperature resistance of the instrument sealing material are also tested. Step 2 includes the following: Step 21: Testing the sealing and compensation performance of a fixed liquid level under high temperature and high pressure. The liquid level in the fixed test apparatus is used to test the sealing and automatic compensation performance of the instruments under different high temperature and high pressure environments. Step 22: 150℃ Dynamic Liquid Level Sealing and Automatic Compensation Performance Test The device was raised to a saturated steam pressure environment of 150℃, and the liquid level of the device was adjusted by a pressure pump. The sealing and automatic compensation performance of the instrument under this temperature and pressure were tested. Step 23: 220℃ dynamic liquid level sealing and automatic compensation performance test; Step 24: 260℃ dynamic liquid level sealing and automatic compensation performance test; Step 25: Static liquid level compensation performance test under saturated steam environment of 110℃~260℃; The liquid level in the fixed device is maintained at 50% of the instrument's measuring range. By continuously adjusting the device's operating conditions, the instrument's compensation performance under different operating conditions is tested. The instrument accuracy is tested in saturated steam environments at 110℃, 150℃, 220℃, and 260℃, and the deviation from the device's reference instrument is recorded. The test deviation must not exceed 3%. Step 26: Dynamic liquid level compensation performance test under saturated steam environment of 110℃~260℃ The liquid level of the continuous adjustment device is tested by measuring the operating conditions of the device under different conditions. The instrument accuracy is tested in saturated steam environments at 110℃, 150℃, 220℃, and 260℃, and the deviation from the device's reference instrument is recorded. The test deviation needs to be determined based on the actual liquid level adjustment accuracy.

2. The method for verifying the performance and reliability of a high-temperature and high-pressure liquid level instrument as described in claim 1, characterized in that, Step 22 includes the following: Step 221: Sealing Test The test lasts for more than 36 hours to confirm whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The visual inspection qualification standard is that the measuring component and the sealing flange do not leak or have water seepage. After the visual inspection, the sealing component is disassembled and inspected. The inspection qualification standard is that the first thermal insulation seal and the sealing ring of the measuring component have no water seepage marks, and the graphite gasket does not leak. Step 222: Automatic Compensation Test With automatic instrument compensation, record the instrument's measured values ​​at 0%, 20%, 40%, 60%, 80%, and 100% of the liquid level, and the deviation of the device's reference instrument. Under static conditions, the liquid level deviation shall not exceed 3%. Step 223: Turn off the automatic compensation test and record the instrument's measured values ​​at 0%, 20%, 40%, 60%, 80%, and 100% of the liquid level, as well as the deviation of the device's reference instrument.

3. The method for verifying the performance and reliability of a high-temperature and high-pressure liquid level instrument as described in claim 1, characterized in that, Step 23 includes the following: Step 231: Sealing Test The test lasts for more than 36 hours to confirm whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The visual inspection qualification standard is that the measuring component and the sealing flange do not leak or have water seepage. After the visual inspection, the sealing component is disassembled and inspected. The inspection qualification standard is that the first thermal insulation seal and the sealing ring of the measuring component have no water seepage marks, and the graphite gasket does not leak. Step 232: Automatic Compensation Test With automatic instrument compensation, record the instrument's measured values ​​at 0%, 20%, 40%, 60%, 80%, and 100% of the liquid level, and the deviation of the device's reference instrument. Under static conditions, the liquid level deviation shall not exceed 3%. Step 233: Turn off the automatic compensation test and record the instrument's measured values ​​at 0%, 20%, 40%, 60%, 80%, and 100% of the liquid level, as well as the deviation of the device's reference instrument.

4. The method for verifying the performance and reliability of a high-temperature and high-pressure liquid level instrument as described in claim 1, characterized in that, Step 24 includes the following: Step 241: Sealing Test The test lasts for more than 36 hours to confirm whether there is water leakage on the flange face of the measuring component and the device, the sealing weld of the measuring component, and the coaxial nut of the measuring component. The visual inspection qualification standard is that the measuring component and the sealing flange do not leak or have water seepage. After the visual inspection, the sealing component is disassembled and inspected. The inspection qualification standard is that the first thermal insulation seal and the sealing ring of the measuring component have no water seepage marks, and the graphite gasket does not leak. Step 242: Instrument Automatic Compensation Test With automatic instrument compensation, record the instrument's measured values ​​at 0%, 20%, 40%, 60%, 80%, and 100% of the liquid level, and the deviation of the device's reference instrument. Under static conditions, the liquid level deviation shall not exceed 3%. Step 243: Perform an automatic compensation test on the instrument and record the instrument's measured values ​​and the deviation of the device's reference instrument at liquid levels of 0%, 20%, 40%, 60%, 80%, and 100%.

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