Test system and method for testing high-temperature corrosion performance of heat transfer tube

Abstract

The present invention relates to the technical field of high-temperature corrosion tests, and in particular to a test system and method for testing the high-temperature corrosion performance of a heat transfer tube. The test system comprises a heating module, a heat exchange module and a high-pressure helium circulation module, wherein the three major modules are connected by means of metal gas path pipes, a test tube sample, a heat exchange tube coil, and auxiliary equipment and accessories for links. A platform has a compact and rational layout, and is environmentally safe and friendly. Using the test method in the present invention, the purpose of performing, on a scaled heat transfer tube component, an inner-tube-wall high-temperature and high-pressure helium test and an outer-tube-wall high-temperature corrosion performance test under a dynamic medium condition can be achieved, thereby obtaining performance test data closer to real service performance data of the heat transfer tube component under an actual working condition. The operation method is simple and feasible, and the data is accurate and reliable, thereby solving the difficult problem of experimental data obtained by existing high-temperature corrosion test apparatuses greatly differing from real running data under actual service environments.

Description

A test system and method for testing the high-temperature corrosion performance of heat transfer tubes Technical Field

[0001] This invention relates to the field of high-temperature corrosion testing technology, and in particular to a test system and method for testing the high-temperature corrosion performance of heat transfer tubes. Background Technology

[0002] The demonstration application of my country's supercritical carbon dioxide (S-CO2) cycle power generation pilot unit and the successful grid connection of the fourth-generation high-temperature gas-cooled reactor (HTGR) nuclear power unit mark a new stage in my country's energy industry's low-carbon, clean, and efficient development, and have become a research hotspot in the energy sector. In these systems, hot-end component materials are typically exposed to high-temperature, high-pressure carburization corrosion environments, facing significant cumulative corrosion from carburization and other processes. For metal components with an expected lifespan of 20 years or even longer, carburization corrosion directly impacts the safe and stable operation of new power generation technologies. To clarify the mechanism of alloy carburization corrosion, researchers have conducted various corrosion tests in the laboratory under simulated actual service conditions, aiming to obtain experimental data on alloy carburization corrosion under different experimental conditions, reveal its common patterns, and thus prevent and control it. However, due to the limitations and constraints of existing laboratory-level carbon corrosion testing equipment, especially the difficulty in meeting the conditions for combined high-temperature, high-pressure, and high-carbon potential corrosion testing, most studies only focus on high-temperature corrosion performance from the perspective of a single corrosive medium or a small range of variable factors. As a result, the results obtained often have large errors compared with the data in actual service environments. They cannot meet the real performance data of metal components under large-scale, wide-range, and multi-factor coupled effects in actual service environments, which significantly misleads the direction of improvement and prevention of corrosion problems in the future.

[0003] To obtain more accurate test data that closely approximates the actual service environment, and taking into full account the original dimensions of the heat transfer tube components and the real-world requirements of multi-factor synergistic corrosion states under conditions such as high temperature, high pressure, helium circulation, and dynamic circulation of corrosive media, a proportional heat transfer tube high-temperature corrosion performance test platform that simultaneously meets the requirements of high temperature, high pressure, helium circulation, and dynamic circulation of corrosive media under real service conditions was designed and developed.

[0004] Summary of the Invention

[0005] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] In view of the above or existing technologies, in order to obtain more accurate test data that is closer to the actual service environment, and to fully consider the original size of the heat transfer tube components and the actual corrosion state under conditions such as high temperature, high pressure, helium circulation, and dynamic circulation of corrosive media, this invention is proposed.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a test system for testing the high-temperature corrosion performance of heat transfer tubes, comprising,

[0008] The heating module includes a vertical metal furnace for holding corrosive media and test tube samples, and an impeller inside for controlling the dynamic balance of the corrosive media.

[0009] A high-pressure helium circulation module includes a circulation pipeline connected to the test tube sample, and a helium source is provided on the circulation pipeline.

[0010] A heat exchange module includes a pressure vessel, the circulation pipeline portion being located within the pressure vessel, and the pressure vessel containing a liquid for cooling the high-temperature helium gas in the circulation pipeline.

[0011] As a preferred embodiment of the test system for testing the high-temperature corrosion performance of heat transfer tubes according to the present invention, the vertical metal heating furnace includes a furnace body and a flange cover installed above the furnace body. A heat insulation layer is provided on the outer wall of the furnace body. A heating element is provided on the furnace body inside the heat insulation layer. A thermocouple for temperature monitoring is installed on the flange cover and extends into the furnace body.

[0012] As a preferred embodiment of the test system for testing the high-temperature corrosion performance of heat transfer tubes according to the present invention, a motor is provided below the vertical metal heating furnace, the output shaft of the motor passes through a sealing hole located at the center of the bottom of the vertical metal heating furnace, and the impeller is mounted on the upper end of the output shaft of the motor.

[0013] As a preferred embodiment of the test system for testing the high-temperature corrosion performance of heat transfer tubes according to the present invention, the circulation pipeline includes a helium source, a multi-section metal gas pipeline, a test tube sample, a heat exchange tube coil, a high-pressure gas circulation pump, and multiple valves, wherein the helium pressure provided by the helium source is in the range of 0.1-15MPa.

[0014] As a preferred embodiment of the test system for testing the high-temperature corrosion performance of heat transfer tubes according to the present invention, the circulation pipeline sequentially includes a metal gas pipe 1, a metal gas pipe 2, a test tube sample, a metal gas pipe 3, a heat exchange tube coil, a metal gas pipe 4, a high-pressure gas circulation pump, a metal gas pipe 5, and a metal gas pipe 6. The metal gas pipe 1, metal gas pipe 2, and metal gas pipe 6 are connected by a T-junction. An external drain pipe is also provided on metal gas pipe 5. A valve 1 is provided on metal gas pipe 1, a pressure gauge and a valve 2 are provided on metal gas pipe 2, a valve 3 is provided on metal gas pipe 3, a valve 4 is provided on metal gas pipe 4, a valve 5 is provided on metal gas pipe 4, a valve 6 is provided on metal gas pipe 6, and a valve 7 is provided on the external drain pipe.

[0015] As a preferred embodiment of the test system for testing the high-temperature corrosion performance of heat transfer tubes according to the present invention, the pressure vessel has an upper elliptical structure and a lower cylindrical structure, and the diameter of the cylindrical part is the same as the minor axis of the elliptical part. A steam outlet valve for releasing high-temperature steam is provided at the top, a water inlet for connecting a water pump is provided at the bottom, and an air inlet and an air outlet for connecting the metal gas pipe and the heat exchange tube coil are respectively provided on the upper and lower sides.

[0016] The heat exchange tube coil is installed inside the cylindrical structure of the pressure vessel;

[0017] The explosion-proof layer is provided around and at the bottom of the pressure vessel.

[0018] As a preferred embodiment of the test system for testing the high-temperature corrosion performance of heat transfer tubes according to the present invention, the test tube sample material can be various alloy steel tubes, ferritic steel tubes, austenitic steel tubes, high-temperature alloy tubes, and nickel-based alloy tubes.

[0019] The shape can be spiral, S-shaped, U-shaped, or irregularly shaped pipe;

[0020] The testing range is for high-temperature and high-pressure corrosion performance within the temperature range of 25-800℃ and the pressure range of 0.1-15MPa.

[0021] To solve the above-mentioned technical problems, the present invention also provides the following technical solution: a test method for testing the high-temperature corrosion performance of heat transfer tubes, comprising the following steps:

[0022] Test sample installation and corrosive medium injection: Open the sealed flange cover, put the test sample tube into the vertical metal heating furnace, then add the experimental amount of corrosive medium, and connect the test sample and the metal gas line. After installing the thermocouple, close the flange cover again to seal it.

[0023] Air purging and helium gas sealing check: After turning on the helium gas source, open each valve in sequence and start the high-pressure gas circulation pump. After purging the air, measure the pressure and observe the change in the pressure gauge pointer to check the sealing of the high-pressure helium gas circulation system.

[0024] Turn on the agitator and use the impeller to drive the corrosive medium inside the vertical metal heating furnace to reach dynamic equilibrium. Then turn on the heat exchange system water pump to inject liquid water, the heat exchange medium, into the pressure vessel. The water level should be above the heat exchange tube coil.

[0025] Turn on the heating system power, set the required temperature, time, heating rate and heating power for the test, and start the high temperature and high pressure corrosion test. At the same time, monitor the changes in temperature, helium pressure and steam pressure in the pressure vessel in real time during the test. If necessary, open the steam outlet valve for pressure relief protection.

[0026] After the test, turn off the power to the heating system, turn off the stirrer, open the valve to depressurize the helium circulation loop, then turn off the high-pressure gas circulation pump. After the boiler cools to room temperature, open the sealing flange cover, take out the test tube sample, and complete the high-temperature corrosion performance test of the heat transfer tube.

[0027] As a preferred embodiment of the test method for testing the high-temperature corrosion performance of heat transfer tubes according to the present invention, the following is specified regarding the air venting and helium sealing check: First, open all valves to vent the air inside the pipeline for 5-10 minutes; then close valves two and five, open valve six, and continue venting for 3-5 minutes; finally, close valve seven, open valves two and five, and close valve one after the pressure gauge shows that the target pressure reaches 0.1-15 MPa.

[0028] As a preferred embodiment of the test method for testing the high-temperature corrosion performance of heat transfer tubes according to the present invention, dynamic equilibrium refers to the uniform distribution of the corrosive medium after mixing inside the vertical metal heating furnace.

[0029] The beneficial effects of this invention are: realistic simulation of actual service environment: the design realizes the simulation of a real service environment with multiple factors such as high temperature, high pressure, dynamic helium circulation, and corrosive medium circulation, with particular emphasis on dynamic medium circulation and helium circulation, which solves the problem that traditional static testing cannot accurately simulate actual working conditions.

[0030] High adaptability: It can test pipe components of different shapes such as spiral, S-shaped, U-shaped and irregular shapes, which shows its breakthrough in adaptability to complex geometry and expands its application range.

[0031] Diverse materials and media: The test pipes range from ordinary alloy steel pipes to high-end nickel-based alloys, and the corrosive media include solid, liquid and solid states, which meets diverse research needs.

[0032] Safe and efficient data: Tested in a completely closed environment, there is no risk of leakage, the data is highly accurate and closer to reality, it is environmentally friendly, and it helps to improve the reliability and security of experimental data.

[0033] Integrated system design: The integrated design of heating, heat exchange, and high-pressure helium circulation systems, especially the precise control of the helium circulation loop, enhances the overall efficiency and flexibility of the system. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0035] Figure 1 is a schematic diagram of the overall test system for testing the high-temperature corrosion performance of heat transfer tubes.

[0036] Figure 2 is a schematic diagram of the overall high-pressure helium gas circulation module.

[0037] Figure 3 shows the corrosion depth curve of the test tube sample after 3000 hours of corrosion.

[0038] Figure 4 shows the microstructure of the cross-section of the test tube sample after 100 hours of corrosion.

[0039] Figure 5 shows the microstructure of the cross-section of the test tube sample after 500 hours of corrosion.

[0040] Figure 6 shows the microstructure of the cross-section of the test tube sample after 1000 hours of corrosion.

[0041] Figure 7 shows the microstructure of the cross-section of the test tube sample after 3000 hours of corrosion.

[0042] In the diagram: 100, heating module; 101, vertical metal heating furnace; 101a, furnace body; 101b, flange cover; 102, impeller; 103, insulation layer; 104, heating element; 105, thermocouple; 106, motor; 200. High-pressure helium circulation module; 201. Circulation pipeline; 201a. Metal gas pipeline; 201a-1. Metal gas pipeline one; 201a-2. Metal gas pipeline two; 201a-3. Metal gas pipeline three; 201a-4. Metal gas pipeline four; 201a-5. Metal gas pipeline five; 201a-6. Metal gas pipeline six; 201a-7. External exhaust pipe; 201b. Heat exchanger coil; 201c. High-pressure gas circulation pump; 201d. Valves; 201d-1. Valve one; 201d-2. Valve two; 201d-3. Valve three; 201d-4. Valve four; 201d-5. Valve five; 201d-6. Valve six; 201d-7. Valve seven; 201e. Pressure gauge; 202. Helium source; 300, Heat exchange module; 301, Pressure vessel; 301a, Steam outlet valve; 302, Feed water pump; 303, Explosion-proof layer; 400, Test tube sample. Detailed Implementation

[0043] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0044] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0045] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0046] Example 1

[0047] Referring to Figures 1-2, this is the first embodiment of the present invention. This embodiment provides a test system for testing the high-temperature corrosion performance of heat transfer tubes, including a heating module 100. The module includes a vertical metal furnace 101 for holding corrosive media and test tube samples 400. An impeller 102 for controlling the dynamic balance of the corrosive media is provided inside the furnace 101. The vertical metal furnace 101 includes a furnace body 101a and a flange cover 101b installed above the furnace body 101a. A heat insulation layer 103 is provided on the outer wall of the furnace body 101a. A heating element 104 is provided on the furnace body 101a inside the heat insulation layer 103. A thermocouple 105 for temperature monitoring is installed on the flange cover 101b, extending into the furnace body 101a. A motor 106 is provided below the vertical metal furnace 101. The output shaft of the motor 106 passes through a sealing hole located at the center of the bottom of the vertical metal furnace 101. The impeller 102 is installed on the upper end of the output shaft of the motor 106.

[0048] It should be noted that the vertical metal heating furnace 101 is the core of the experiment. Its dimensions are variable, with a diameter range of 0.1 to 1.5 meters and a height of 0.3 to 3 meters. It is designed to withstand a pressure of at least 15 MPa, sufficient to withstand high-temperature and high-pressure environments. The motor 106 and impeller 102 form a stirrer installed at the bottom of the vertical metal heating furnace 101, driven by the motor 106. The impeller 102 is installed through a sealed hole through which the central rotating shaft passes, ensuring no leakage. This stirs and circulates the corrosive medium, forming a dynamic balance and improving the simulation accuracy of the test. The flange cover 101b covers the furnace body 101a, sealing it and facilitating the installation of the test sample 400. It also has two metal gas passage pipes, 201a-2 and 201a-3, and a central mounting hole for installing a thermocouple 105. The thermocouple 105 monitors the temperature in real time, ensuring the condition inside the furnace. The heating element 104 is arranged around the wall of the furnace body 101a and embedded in the insulation layer 103 to ensure uniform heating distribution. The heating module 100, through its integrated heating system, stirrer, dynamic medium circulation, and precise heating control and monitoring, simulates the high temperature and high pressure and dynamic corrosion process in actual service environments, providing an accurate and reliable platform for testing the durability of heat transfer pipes.

[0049] High-pressure helium circulation module

[0050] 200 includes a circulation pipeline 201 connected to the test sample 400, and a helium source 202 is installed on the circulation pipeline 201. The circulation pipeline 201 includes the helium source 202, multiple metal gas passage pipes 201a, the test sample 400, a heat exchange tube coil 201b, a high-pressure gas circulation pump 201c, and multiple valves 201d. The helium pressure provided by the helium source 202 is in the range of 0.1-15MPa. The circulation pipeline 201 sequentially includes metal gas passage pipe one 201a-1, metal gas passage pipe two 201a-2, test sample 400, metal gas passage pipe three 201a-3, heat exchange tube coil 201b, metal gas passage pipe four 201a-4, high-pressure gas circulation pump 201c, metal gas passage pipe five 201a-5, and metal gas passage pipe six 201a-6. Metal gas pipe 1 201a-1, metal gas pipe 2 201a-2, and metal gas pipe 6 201a-6 are connected by a T-connector. Metal gas pipe 5 201a-5 is also equipped with an external drain pipe 201a-7. Metal gas pipe 1 201a-1 is equipped with valve 1 201d-1. Metal gas pipe 2 201a-2 is equipped with pressure gauge 201e and valve 2 201d-2. Metal gas pipe 3 201a-3 is equipped with valve 3 201d-3. Metal gas pipe 4 201a-4 is equipped with valve 4 201d-4. Metal gas pipe 4 201a-4 is equipped with valve 5 201d-5. Metal gas pipe 6 201a-6 is equipped with valve 6 201d-6. External drain pipe 201a-7 is equipped with valve 7 201d-7.

[0051] It should be noted that the circulation pipeline 201 includes a helium source 202, multiple metal gas path pipes 201a, a test sample 400, a heat exchange coil 201b, a high-pressure gas circulation pump 201c, and multiple valves 201d, forming a closed loop. This allows helium to circulate within the test sample 400 and the test environment, simulating high-temperature and high-pressure conditions. The helium source 202 can provide helium pressures from 0.1 to 15 MPa, covering a wide range of experimental needs and ensuring corrosion performance studies under different test pressures. This high-pressure helium circulation system is precisely and efficiently designed. Through complex but orderly gas path control, it not only simulates high temperature and high pressure but also ensures the accuracy and safety of the test environment. The configuration of valves 201d and pressure monitoring points in each link provides flexible, safe, and data-driven control for the experiment, ensuring the accuracy of corrosion performance studies.

[0052] The heat exchange module 300 includes a pressure vessel 301, with a circulation pipeline 201 located inside the pressure vessel 301. The pressure vessel 301 contains a liquid for cooling the high-temperature helium gas in the circulation pipeline 201. The pressure vessel 301 has an elliptical upper part and a cylindrical lower part, with the diameter of the cylindrical part being the same as the minor axis of the elliptical part. A steam outlet valve for releasing high-temperature steam is provided at the top, and a water inlet is provided at the bottom for connecting to a water pump 302. An air inlet and an air outlet are provided on the upper and lower sides for connecting a metal gas pipe 201a and a heat exchange tube coil 201b, respectively. The heat exchange tube coil 201b is installed inside the cylindrical structure of the pressure vessel 301. An explosion-proof layer 303 is provided around and at the bottom of the pressure vessel 301.

[0053] It should be noted that the design, with an upper elliptical shape and a lower cylindrical shape, optimizes space utilization and fluid heat exchange efficiency. The lower cylindrical structure of pressure vessel 301 has a diameter of 0.2-2m and a height of 0.2-2.8m, while the upper elliptical structure has a minor axis of 0.2-2m and a major axis that is 1.3-1.7 times the minor axis. This optimizes steam release and also considers the thermodynamic stability of the top space, ensuring the overall structural safety and the adaptability and simulation range of test tube samples of different sizes.

[0054] The test tube sample 400 can be made of various alloy steel pipes, ferritic steel pipes, austenitic steel pipes, high-temperature alloy pipes, and nickel-based alloy pipes; the shape can be spiral, S-shaped, U-shaped, or irregular shaped pipes; the test range is: high temperature and high pressure corrosion performance within the range of 25-800℃ and 0.1-15MPa.

[0055] 1) This invention can simultaneously conduct high-temperature and high-pressure helium gas tests on the inner wall of heat transfer tube components of different shapes and specifications, such as spiral, S-shaped, U-shaped, and irregular irregular shapes, and high-temperature corrosion performance tests on the outer wall of the tube under dynamic medium conditions. It overcomes the shortcomings of existing high-temperature corrosion test devices that lack sufficient corrosion conditions and achieves the goal of conducting corrosion performance tests on components of various specifications under the synergistic coupling of multiple factors such as high temperature, high pressure, long time, and dynamic medium corrosion.

[0056] 2) The performance test data obtained by using this invention is closer to the actual service data of heat transfer tube components under actual operating conditions, which can provide more accurate core data and theoretical criteria for key aspects such as safety maintenance, material selection, performance design and life evaluation of heat transfer tube components of subsequent units.

[0057] 3) The heat transfer tube components tested in this invention are carried out in a completely closed environment, with no risk of leakage from the dynamic corrosive medium, making it environmentally safe and friendly. At the same time, it is less affected by external factors and the data is highly accurate.

[0058] A test method for testing the high-temperature corrosion performance of heat transfer tubes includes the following steps:

[0059] Installation of test tube 400 and injection of corrosive medium: Open the sealed flange cover 101b, put the test tube into the vertical metal heating furnace 101, then add the amount of corrosive medium required for the experiment, and connect the test tube 400 and the metal gas pipeline. After installing the thermocouple 105, close the flange cover 101b again to seal it.

[0060] Air purging and helium gas sealing check: After turning on the helium source 202, open each valve 201d in sequence and start the high-pressure gas circulation pump 201c. After purging the air, measure the pressure and observe the change of the pointer on the pressure gauge 201e to check the sealing of the high-pressure helium circulation system. Specifically: First, open each valve 201d to purge the air inside the pipeline for 5-10 minutes; then close valve 201d-2 and valve 501d-5, open valve 601d-6, and continue purging for 3-5 minutes; finally, close valve 701d-7, open valve 201d-2 and valve 501d-5, and close valve 101d-1 after the pressure gauge 201e shows that the target pressure has reached 0.1-15MPa.

[0061] Turn on the agitator, and drive the corrosive medium in the vertical metal heating furnace 101 to reach dynamic equilibrium through the impeller 102. Then turn on the heat exchange system water pump 302 to inject liquid water, the heat exchange medium, into the pressure vessel 301. The water level should be above the heat exchange tube coil 201b.

[0062] Turn on the power to the heating system, set the required temperature, time, heating rate and heating power for the test, and start the high temperature and high pressure corrosion test. At the same time, monitor the changes in temperature, helium pressure and steam pressure in pressure vessel 301 in real time during the test. If necessary, open the steam outlet valve for pressure relief protection.

[0063] After the test, turn off the power to the heating system and the stirrer. Open valve 201d to depressurize the helium circulation loop, then turn off the high-pressure gas circulation pump 201c. After the furnace cools to room temperature, open the sealing flange cover 101b, take out the test tube sample 400, and complete the high-temperature corrosion performance test of the heat transfer tube.

[0064] Example 2

[0065] Referring to Figures 1-7, this is the second embodiment of the present invention. Unlike the previous embodiment, this embodiment uses a spiral-shaped austenitic stainless steel as the test tube sample 400 for testing, as detailed below:

[0066] I. Equipment parameters and experimental conditions:

[0067] Test tube sample 400 is made of austenitic stainless steel spiral tube with dimensions of 10mm diameter, 1500mm length, 20mm pitch, 19mm tube diameter, and 3mm wall thickness, simulating actual working conditions.

[0068] Test temperature: 650℃, simulating a high-temperature environment.

[0069] Duration: 300 hours, to ensure long-term durability assessment.

[0070] Corrosive medium: pure graphite powder, simulating a complex corrosive environment.

[0071] The internal helium pressure of the test tube sample 400 is 7 MPa, ensuring dynamic circulation.

[0072] Heating rate: 7℃ / min to raise the temperature from room temperature to 650℃ within 90 minutes.

[0073] Corrosion resistance assessment: Corrosion depth was recorded every 10 hours, for a total of 300 sets of data, as shown in Figure 2, which visually presents the corrosion trend.

[0074] Microscopic morphology observation: Figures 3-7 show cross-sections observed at 100h, 500h, 1000h, and 3000h respectively. The consistency of corrosion depth was analyzed, and the cross-sectional morphology was basically consistent with the measured values.

[0075] II. Test Procedure

[0076] Installation of Test Sample 400 and Injection of Corrosive Medium: First, ensure all equipment is in a safe condition. Open the sealed flange cover 101b and precisely place the test sample tube into the vertical metal heating furnace 101. Then, add a measured amount of corrosive medium: pure graphite powder, according to the experimental design. Next, properly connect the test sample 400 to the outlet of metal gas line 201a-2 and the inlet of metal gas line 301a-3. Install thermocouple 105 on flange cover 101b to monitor the temperature. Finally, reseal flange cover 101b to ensure the entire system is leak-free.

[0077] Purge and Helium Leakage Check: Then, start the helium source 202 and sequentially open valves 1 (201d-1) to 7 (201d-7), while simultaneously starting the high-pressure gas circulation pump 201c to purge air from the pipeline for 5 to 10 minutes. Next, close valves 2 (201d-2) and 5 (201d-5), and open valve 6 (201d-6) to continue purging for 3 to 5 minutes. Finally, close valve 7 (201d-7), and open valves 2 (201d-2) and 5 (201d-5). Once pressure gauge 201e shows the target pressure reaches 0.1-15 MPa, close valve 1 (201d-1). Observe the change in the pressure gauge 201e pointer to check the sealing of the high-pressure helium circulation module 200. If there are no sealing issues, inject helium into the circulation pipeline 201 until the helium pressure reaches 7 MPa.

[0078] Preparation of the dynamic medium circulation and heat exchange system: Start motor 106 to drive impeller 102 to rotate, which in turn stirs and mixes the corrosive medium in furnace body 101a until the corrosive medium is dynamically balanced and evenly distributed (this dynamic balance is related to the selection of the corrosive medium; if graphite powder is selected as the corrosive medium, the graphite powder will settle due to gravity. The rotation of the impeller 102 at the bottom stirrer ensures that the graphite powder is evenly distributed in the furnace tube, and the settling rate and rising rate reach dynamic balance). At the same time, start the water pump 302 of heat exchange module 300 to inject liquid water into pressure vessel 301. The water volume should cover heat exchange tube coil 201b to ensure effective heat exchange.

[0079] Heating and Monitoring: Turn on the heating system and set the required temperature, time, heating rate, and heating power for the experiment: target temperature 650℃, heating time 90 minutes, test duration 3000 hours, sampling and analysis at specific time points such as 100h and 500h. During the experiment, closely monitor the temperature, helium pressure, and steam pressure in pressure vessel 301. If the pressure exceeds the safe range, open the steam outlet valve to release pressure as appropriate.

[0080] Test Completion: After the test, first shut down the heating system and stirrer, release the pressure of the helium circulation loop by opening valve 7 201d-7, and then stop the high-pressure gas circulation pump 201c. After the furnace body 101a has cooled naturally to room temperature, open the sealed flange cover 101b and carefully remove the test tube sample 400. At this point, the high-temperature corrosion performance test of the heat transfer tube is completed.

[0081] Data processing and archiving: (1) Corrosion depth measurement: The corrosion depth of the test tube sample 400 surface and cross-section was measured using professional measuring tools (such as optical or electron microscopes, ultrasonic probe tip thickness gauges). Records were taken every 10 hours to ensure the continuity and integrity of the data. Corrosion rate calculation: Based on the difference in corrosion depth after each measurement, the corrosion rate (such as mm / h or mm / a) was calculated in combination with the time interval. This helps to intuitively show the dynamic change of corrosion rate over time.

[0082] (2) Database Establishment: Utilize software (such as Excel, SQL Server, Python pandas, MATLAB, etc.) to establish a database, setting fields for each pipe material, temperature, pressure, time point, corrosive medium, etc., and inputting each measurement data for easy querying, sorting, and filtering. Data Verification: Cross-check the input data to confirm no errors and ensure data accuracy. Remove outliers (such as outliers), analyze the reasons, or remove them.

[0083] (3) Detailed Evidence for Analysis and Subsequent Research: 1) Trend Analysis: Plotting graphs (line graphs, scatter plots, bar charts) to show the relationship between corrosion depth and rate with time, temperature, medium, and pressure, providing intuitive trends and identifying patterns. 2) Statistical Analysis: Using statistical methods (such as ANOVA, regression analysis, correlation analysis) to quantify the strength of correlations between variables and predictive power, providing a basis for theoretical model construction. 3) Model Construction and Prediction: Combining data, corrosion prediction models (such as neural networks, regression models) can be constructed, inputting material and environmental parameters to predict corrosion performance, providing data support for future designs. 4) Report Writing: Summarizing the experimental process, results, analysis, discussion, and conclusions in the report, emphasizing novel findings, improvements, and limitations, providing detailed evidence for future technological advancements and subsequent research.

[0084] This embodiment demonstrates the comprehensive performance and data processing capabilities of the system by applying austenitic stainless steel spiral tubes in high-temperature corrosion testing. Dynamic monitoring and precise recording of corrosion depth data, combined with microscopic morphology analysis, not only intuitively reflect the corrosion process but also verify the consistency of the system's data across complex morphologies. This example showcases the equipment's ability to accurately simulate actual service environments under different parameters, providing precise data support for subsequent material design and lifespan assessment, highlighting its advanced nature and practicality in the field of high-temperature corrosion testing.

[0085] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape, and proportions of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be changed or altered. Therefore, all such modifications are intended to be included within the scope of the invention. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and not only structurally equivalent but also equivalent in structure. Other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments without departing from the scope of the invention. Therefore, the present invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0086] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the best mode of carrying out the invention as currently considered, or those features that are not relevant to implementing the invention) may be omitted.

[0087] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0088] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A test system for testing the high-temperature corrosion performance of heat transfer tubes, characterized in that: include, Heating module (100) includes a vertical metal furnace (101) for holding corrosive media and test tube sample (400), and an impeller (102) is provided inside for controlling the dynamic balance of the corrosive media. A high-pressure helium circulation module (200) includes a circulation pipeline (201) connected to the test tube sample (400), and a helium source (202) is provided on the circulation pipeline (201). A heat exchange module (300) includes a pressure vessel (301), a circulation pipeline (201) is partially located inside the pressure vessel (301), and the pressure vessel (301) contains a liquid for cooling the high-temperature helium gas in the circulation pipeline (201).

2. The test system for testing the high-temperature corrosion performance of heat transfer tubes as described in claim 1, characterized in that: The vertical metal heating furnace (101) includes a furnace body (101a) and a flange cover (101b) installed above the furnace body (101a). A heat insulation layer (103) is provided on the outer wall of the furnace body (101a). A heating element (104) is provided on the furnace body (101a) inside the heat insulation layer (103). A thermocouple (105) for temperature monitoring is installed on the flange cover (101b) and extends into the furnace body (101a).

3. The test system for testing the high-temperature corrosion performance of heat transfer tubes as described in claim 1 or 2, characterized in that: A motor (106) is provided below the vertical metal heating furnace (101). The output shaft of the motor (106) passes through a sealing hole located at the center of the bottom of the vertical metal heating furnace (101). The impeller (102) is mounted on the upper end of the output shaft of the motor (106).

4. The test system for testing the high-temperature corrosion performance of heat transfer tubes as described in claim 1, characterized in that: The helium source (202), multi-section metal gas pipe (201a), test tube (400), heat exchange coil (201b), high-pressure gas circulation pump (201c) and multiple valves (201d) constitute a helium circulation route, wherein the helium source (202) provides helium pressure in the range of 0.1-15MPa.

5. The test system for testing the high-temperature corrosion performance of heat transfer tubes as described in claim 4, characterized in that: The circulation pipeline (201) sequentially includes metal gas pipe one (201a-1), metal gas pipe two (201a-2), test tube sample (400), metal gas pipe three (201a-3), heat exchange tube coil (201b), metal gas pipe four (201a-4), high-pressure gas circulation pump (201c), metal gas pipe five (201a-5), and metal gas pipe six (201a-6). Metal gas pipe one (201a-1), metal gas pipe two (201a-2), and metal gas pipe six (201a-6) are connected by a T-junction. Metal gas pipe five (201a-5) is also equipped with an external... The pipeline (201a-7) is equipped with valve 1 (201d-1) on metal gas pipeline 1 (201a-1), pressure gauge (201e) and valve 2 (201d-2) on metal gas pipeline 2 (201a-2), valve 3 (201d-3) on metal gas pipeline 3 (201a-3), valve 4 (201d-4) on metal gas pipeline 4 (201a-4), valve 5 (201d-5) on metal gas pipeline 5 (201a-5), valve 6 (201d-6) on metal gas pipeline 6 (201a-6), and valve 7 (201d-7) on the external exhaust pipe (201a-7).

6. The test system for testing the high-temperature corrosion performance of heat transfer tubes as described in claim 4, characterized in that: The pressure vessel (301) has an elliptical upper part and a cylindrical lower part, with the diameter of the cylindrical part being the same as the minor axis of the elliptical part. A steam outlet valve (301a) for releasing high-temperature steam is provided at the top, and a water inlet is provided at the bottom for connecting to a water pump (302). An air inlet and an air outlet are provided on the upper and lower sides for connecting the metal gas pipe (201a) and the heat exchange tube coil (201b), respectively. The heat exchange tube coil (201b) is installed inside the cylindrical structure of the pressure vessel (301); An explosion-proof layer (303) is provided around and at the bottom of the pressure vessel (301).

7. The test system for testing the high-temperature corrosion performance of heat transfer tubes as described in claim 1, characterized in that: The test tube sample (400) can be made of various alloy steel pipes, ferritic steel pipes, austenitic steel pipes, high-temperature alloy pipes and nickel-based alloy pipes; The shape can be spiral, S-shaped, U-shaped, or irregularly shaped pipe; The testing range is for high-temperature and high-pressure corrosion performance within the temperature range of 25-800℃ and the pressure range of 0.1-15MPa.

8. A test method for testing the high-temperature corrosion performance of heat transfer tubes, characterized in that: The test system for testing the high-temperature corrosion performance of heat transfer tubes as described in any one of claims 1 to 7, and includes the following steps: Test sample installation and corrosive medium injection: Open the sealed flange cover, put the test sample tube into the vertical metal heating furnace, then add the experimental amount of corrosive medium, and connect the test sample and the metal gas line. After installing the thermocouple, close the flange cover again to seal it. Air purging and helium gas sealing check: After turning on the helium gas source, open each valve in sequence and start the high-pressure gas circulation pump. After purging the air, measure the pressure and observe the change in the pressure gauge pointer to check the sealing of the high-pressure helium gas circulation system. Turn on the agitator and use the impeller to drive the corrosive medium inside the vertical metal heating furnace to reach dynamic equilibrium. Then turn on the heat exchange system water pump to inject liquid water, the heat exchange medium, into the pressure vessel. The water level should be above the heat exchange tube coil. Turn on the heating system power, set the required temperature, time, heating rate and heating power for the test, and start the high temperature and high pressure corrosion test. At the same time, monitor the changes in temperature, helium pressure and steam pressure in the pressure vessel in real time during the test. If necessary, open the steam outlet valve for pressure relief protection. After the experiment, turn off the power to the heating system, turn off the stirrer, and open the valve to circulate the helium gas. Depressurize the boiler, then shut down the high-pressure gas circulation pump. After the boiler cools to room temperature, open the sealing flange cover, remove the test tube sample, and complete the high-temperature corrosion performance test of the heat transfer tube.

9. The test method for testing the high-temperature corrosion performance of heat transfer tubes as described in claim 8, characterized in that: Regarding the air purging and helium sealing check: First, open all valves to purge the air inside the pipeline for 5-10 minutes; then close valves 2 and 5, open valve 6, and continue purging for 3-5 minutes; finally, close valve 7, open valves 2 and 5, and close valve 1 after the pressure gauge shows the target pressure reaches 0.1-15 MPa.

10. The test method for testing the high-temperature corrosion performance of heat transfer tubes as described in claim 8 or 9, characterized in that: Dynamic equilibrium refers to the uniform distribution of corrosive media within a vertical metal heating furnace after mixing.

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