System and method for testing high-temperature corrosion rate of water-cooled wall pipe in operation

Abstract

The invention discloses a system and a method for testing the high-temperature corrosion rate of a water-cooled wall pipe in operation. The testing system comprises a control unit and a plurality of testing units, any testing unit comprises a first temperature measuring assembly arranged on a water cooling wall tube and a testing sample piece which penetrates through a water cooling wall fin and is movably arranged in the vertical direction of the water cooling wall fin, and a second temperature measuring assembly is arranged on the testing sample piece; the first temperature measuring assembly and the second temperature measuring assembly are connected with the control unit. The system is simple in structure and reasonable in design, the synchronous test of the high-temperature corrosion rate of the water-cooled wall pipe in operation is effectively realized, and the test reliability is effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of safe operation of power station boilers, and relates to a high-temperature corrosion rate testing system and a testing method for water-cooled wall pipes in operation. Background Art

[0002] In laboratory environments, one-dimensional furnaces are often used to measure the corrosion composition and thinning rate of metal specimens in high-temperature environments. This method is widely recognized for its high accuracy. However, despite its high accuracy, this method still faces many challenges in practical applications. Among them, the most critical problem is that the flue gas composition and temperature conditions provided by the one-dimensional furnace cannot fully simulate and represent the complex working conditions of the boiler water-cooled wall in the actual service environment. The surface temperature of the specimens in the laboratory also cannot accurately reflect the actual temperature distribution of the water-cooled wall tubes inside the boiler, which leads to the limitations of the one-dimensional furnace test results. Specifically, these test results are difficult to fully and accurately represent the high-temperature corrosion risks faced by different positions in the actual operation of the boiler, and cannot effectively predict and guide the changing trend of the high-temperature corrosion rate of the water-cooled wall under variable working conditions. In addition, the measurement of high-temperature corrosion thinning is usually carried out during the maintenance period of the boiler, and such measurements cannot be carried out during the normal operation of the boiler. Since the maintenance period is often short and there is a large uncertainty, the measurement of high-temperature corrosion thinning may not be carried out in time. Once the measurement is not timely, excessive thinning caused by corrosion and insufficient pressure bearing capacity may cause safety hazards such as leakage. What is more serious is that during the operation of the boiler, if there is a change in the type of coal (such as switching to high-sulfur coal) or equipment degradation (such as air preheater blockage leading to insufficient output of the induced draft fan and reduced oxygen in the main combustion zone), the impact of these changes on the high-temperature corrosion thinning rate cannot be reflected in time in the offline measurement during the maintenance period. This means that the traditional offline high-temperature corrosion measurement method during the maintenance period has obvious lag in responding to changes in boiler operating conditions, making it difficult to achieve abnormal warning and feedback adjustment of operating modes.

[0003] In order to make up for this deficiency, the near-wall atmosphere measurement technology came into being. This technology can measure the content of key atmosphere components such as CO and H2S near the water-cooled wall area online, providing a new perspective for evaluating high-temperature corrosion conditions. However, near-wall atmosphere measurement is still an indirect measurement method. Although there is a certain correlation between it and the high-temperature corrosion thinning rate, it cannot directly and quantitatively obtain the corrosion thinning rate of the pipe, and the reliability of the test results is poor. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a high-temperature corrosion rate testing system and method for water-cooled wall tubes in operation, thereby solving the technical problems that the testing method in the prior art cannot directly obtain the corrosion and thinning rate of the tubes in operation and the test results have poor accuracy.

[0005] The present invention is achieved through the following technical solutions: A high-temperature corrosion rate testing system for water-cooled wall pipes in operation, comprising a control unit and a plurality of testing units; Any of the test units comprises a first temperature measuring component arranged on the water-cooled wall tube, and a test sample penetrating the water-cooled wall fin and movably arranged along the vertical direction of the water-cooled wall fin, and a second temperature measuring component is arranged on the test sample; The first temperature measuring component and the second temperature measuring component are both connected to the control unit.

[0006] Preferably, the water-cooled wall fins are provided with through holes; the test specimen passes through the through holes and is movably arranged in a vertical direction along the water-cooled wall fins.

[0007] Preferably, the test sample is gap-matched with the water-cooling wall fins.

[0008] Preferably, several of the test units are arranged between the bottom burner and the burnout air nozzle; when the boiler is an opposed-firing boiler, the test units are all located on the side walls; when the boiler is a tangential-circle-firing boiler, the test units are located downstream of the center line of each wall and the jet direction.

[0009] Preferably, 1 to 3 of the test units are evenly spaced apart on the single-sided water-cooled wall between the burners of adjacent layers.

[0010] Preferably, any one of the test samples is connected to a position control component, and the position control component is connected to the control unit.

[0011] Preferably, the material of the test sample is the same as the material of the water-cooled wall tube.

[0012] A method for testing the high temperature corrosion rate of water-cooled wall pipes in operation, which is tested by the testing system described in any one of claims 1 to 7; specifically comprising the following steps: Setting a temperature difference threshold, and obtaining a real-time absolute value of the temperature difference between the outer wall temperature of the water-cooled wall tube and the temperature at the location of the test sample through the first temperature measuring component and the second temperature measuring component; The position of the test sample inside the water-cooled wall is adjusted to control the absolute value of the real-time temperature difference to be no greater than the temperature difference threshold, and the test sample is kept running under the same operating conditions as the water-cooled wall tube, and is taken out regularly to perform a high-temperature corrosion rate test on the water-cooled wall tube during operation.

[0013] Preferably, the temperature difference threshold is -50°C~50°C.

[0014] Preferably, the position of the test sample inside the water-cooled wall is adjusted to control the real-time temperature difference to be within the temperature difference threshold range, specifically: when the real-time temperature difference between the position of the test sample and the temperature of the outer wall of the water-cooled wall tube is greater than 50°C, the test sample is moved toward the outside of the water-cooled wall; when the real-time temperature difference between the position of the test sample and the temperature of the outer wall of the water-cooled wall tube is less than -50°C, the test sample is moved toward the inside of the water-cooled wall.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention provides a high-temperature corrosion rate testing system for water-cooled wall tubes in operation. Firstly, the system can accurately obtain the water-cooled wall tube wall temperature and the temperature of the test sample position by arranging a first temperature measuring component on the water-cooled wall tube and arranging a second temperature measuring component on the test sample passing through the water-cooled wall fins. The temperature difference is adjusted by a control unit to ensure that the working condition of the test sample is consistent with the working condition of the outer wall of the water-cooled wall tube, so that the test is performed under the same conditions, thereby improving the accuracy and reliability of the test results. Secondly, the first temperature measuring component and the second temperature measuring component are connected to the control unit, which can monitor the temperature data in real time and adjust the temperature as needed to ensure the temperature stability during the test. This real-time monitoring and precise control capability helps to reduce the test error caused by temperature fluctuations and improve the accuracy of the test. In addition, the test sample passes through the water-cooled wall fins and is set in a vertical direction. This design facilitates the installation, adjustment and replacement of the test sample. After the test cycle is over, the test sample can be easily taken out for measurement and characterization without large-scale disassembly or adjustment of the entire water-cooled wall system, which improves the test efficiency and convenience. The system allows the measurement and characterization of the test sample after a certain period of synchronous operation. The test cycle can be flexibly set according to actual needs. This flexibility helps to adapt to the test requirements under different working conditions, and make necessary adjustments and optimizations according to the test results. The system has a simple structure and a reasonable design, which effectively realizes the synchronous test of the high-temperature corrosion rate of the water-cooled wall pipes in operation, and effectively improves the reliability of the test.

[0016] In addition, the present invention also discloses a method for testing the high-temperature corrosion rate of water-cooled wall pipes in operation. First, by setting a temperature difference threshold range and obtaining the temperature difference between the water-cooled wall pipe and the test sample in real time, the method can accurately control the working condition of the test sample to be consistent with the working condition of the outer wall of the water-cooled wall pipe. The method can effectively meet the test of the high-temperature corrosion rate of water-cooled wall pipes in operation and improve the accuracy of the test; secondly, the method simplifies the test process and reduces the difficulty of operation through intelligent temperature control and position adjustment. The operator only needs to set the temperature difference threshold range and regularly check the working condition and corrosion of the test sample; in addition, since the test sample can be tested under the same conditions as the actual operating conditions, reliable test results can be obtained without waiting for a long test cycle. This helps to speed up the development of new products and reduce testing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a structural schematic diagram of a high-temperature corrosion rate testing system for water-cooled wall tubes in operation in the present invention.

[0019] Wherein: 1. control unit, 2. test unit, 21. first temperature measuring component, 22. test sample, 23. second temperature measuring component, 24. position control component, 3. water-cooled wall, 31. water-cooled wall tube, 32. water-cooled wall fin, 33. through hole. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0023] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0024] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings: Example 1 The water-cooled wall is the main evaporation heating surface in the boiler, responsible for absorbing the radiation heat from the high-temperature flame or flue gas in the furnace. In large-capacity boilers, the flame temperature in the furnace is very high, and the intensity of heat radiation is very high. 40%~50% or even more heat in the boiler is absorbed by the water-cooled wall. By absorbing the high-temperature heat in the furnace, the water-cooled wall effectively reduces the temperature of the furnace wall, thereby preventing the furnace wall from being burned by the high-temperature flame. Figure 1 As shown, the water-cooled wall 3 includes a water-cooled wall tube 31 and a water-cooled wall fin 32 that are connected and arranged. The outer wall of the water-cooled wall tube 31 is severely corroded, and its high-temperature corrosion rate needs to be tested. The existing test cannot realize the test of the high-temperature corrosion rate of the water-cooled wall tube in operation, resulting in poor accuracy, reliability and real-time performance of the test results.

[0027] Based on the above problems, the present invention discloses a high-temperature corrosion rate testing system for water-cooled wall tubes in operation, specifically, comprising a control unit 1 and a plurality of test units 2; any of the test units 2 comprises a first temperature measuring component 21 arranged on the water-cooled wall tube 31, and a test sample 22 passing through the water-cooled wall fin 32 and movably arranged in a vertical direction along the water-cooled wall fin 32, and a second temperature measuring component 23 is provided on the test sample 22; the first temperature measuring component 21 and the second temperature measuring component 23 are both connected to the control unit 1.

[0028] The test system of the present invention is mainly composed of a control unit 1 and several test units 2. The control unit 1, as the center of the system, is responsible for receiving and processing data from each test unit, and making decisions and controls according to a preset algorithm. The test unit 2 is responsible for temperature monitoring on a specific water-cooled wall tube 31 and position control of the test sample 22 to simulate and evaluate the high-temperature corrosion of the water-cooled wall tube.

[0029] The first temperature measuring component 21 is arranged on the water-cooled wall tube 31, and is used for real-time monitoring of the temperature of the water-cooled wall tube. Its accuracy and response speed are crucial for accurately evaluating the corrosion rate. In the present invention, the first temperature measuring component adopts advanced temperature sensor technology, which can ensure stable operation in high temperature, high pressure and corrosive environment.

[0030] The test specimen 22 is a key component for evaluating the corrosion rate of the water wall tube. Its material is the same as the water wall tube to ensure the accuracy and comparability of the test results. The test specimen passes through the water wall fin 32 and is movably arranged along the vertical direction of the fin to perform temperature monitoring and corrosion testing at different positions.

[0031] The second temperature measuring component 23 is arranged on the test sample and is used to monitor the temperature of the test sample in real time. Similar to the first temperature measuring component, the second temperature measuring component also adopts advanced temperature sensor technology to ensure the accuracy and reliability of the test.

[0032] Each of the test samples 22 is connected to a position control component 24, which is connected to the control unit 1. The position control component 24 is connected to the test sample and is used to adjust the position of the test sample according to the command of the control unit. This function is crucial to ensure that the test sample is always in the same temperature environment as the water-cooled wall tube. The position control component uses a precise drive mechanism and sensor technology to achieve fast and accurate position adjustment. Specifically, the position control component 24 can be a stepper motor.

[0033] In addition, in order to set the test sample 22 on the water-cooled wall fin 32, the present invention opens a through hole 33 on the water-cooled wall fin. The test sample passes through the through hole and is movably arranged along the vertical direction of the fin. This design not only facilitates the installation and removal of the test sample, but also ensures that the test sample can be closely matched with the water-cooled wall fin to avoid loosening or falling off under high temperature and high pressure environment.

[0034] In addition, the test sample and the water-cooled wall fin preferably adopt a clearance fit. This fit ensures that the test sample can move freely and avoids friction and wear caused by too tight fit. The size of the gap is accurately calculated and optimized to ensure that the test sample will not be subject to excessive resistance or interference during movement.

[0035] In order to comprehensively evaluate the high-temperature corrosion of the water-cooled wall tubes, the present invention sets a number of test units 2 on the side wall of the boiler. These test units are evenly distributed on the side wall, and the vertical distance between them and the burner is 0.5m. This distance is determined according to the actual operation of the boiler and the test requirements, in order to ensure that the test unit can accurately reflect the corrosion of the water-cooled wall tubes near the burner.

[0036] In a specific preferred embodiment, a plurality of the test units 2 are arranged between the bottom burner and the burnout air nozzle; when the boiler is an opposed combustion boiler, the test units 2 are all located on the side walls; when the boiler is a tangential combustion boiler, the test units 2 are located downstream of the center line of each wall and the jet direction.

[0037] When the boiler is an opposed-firing boiler, 1 to 3 test units 2 are evenly spaced apart on the single-sided water-cooled wall between the burners of adjacent layers.

[0038] Preferably, for the opposed-firing boiler, the present invention evenly arranges three test units between the burners of adjacent layers. This layout not only improves the accuracy and comprehensiveness of the test, but also facilitates comparison and analysis of the corrosion conditions in different areas of the boiler.

[0039] The present invention can significantly improve the accuracy and reliability of the test through precise temperature monitoring and position control. The first temperature measuring component and the second temperature measuring component can monitor the temperature of the water-cooled wall tube and the test sample in real time, and provide accurate data support for the evaluation of the corrosion rate. The position control component can quickly and accurately adjust the position of the test sample according to the instruction of the control unit to ensure that the test sample is always in the same temperature environment as the water-cooled wall tube. This precise temperature control and position control capability enables the present invention to more realistically simulate the corrosion conditions of the water-cooled wall tube in actual operation, so as to more accurately evaluate its high-temperature corrosion rate. Through the test system provided by the present invention, the high-temperature corrosion rate of the water-cooled wall tube can be tested and evaluated regularly. These test data can provide strong support for the operation and maintenance strategy of the boiler. For example, the operating parameters of the boiler can be adjusted in time according to the changing trend of the corrosion rate to slow down the corrosion rate; at the same time, a reasonable maintenance plan can also be formulated according to the corrosion situation to ensure the safe operation of the boiler. In addition, by comparing and analyzing the corrosion conditions in different areas, potential problems and hidden dangers in the operation of the boiler can also be found, providing a useful reference for the maintenance and optimization of the boiler. The present invention not only provides a strong guarantee for the safe operation of the boiler, but also provides important support for the development and innovation of anti-corrosion technology. By deeply analyzing the corrosion mechanism and influencing factors of the test sample, the research and development of new anti-corrosion materials and technologies can be promoted. The application of these new technologies and new materials will further extend the service life of the boiler, improve energy efficiency, and reduce operating costs. In addition, the test system of the present invention can also serve as an important platform for the development and verification of anti-corrosion technology, providing reliable data support for the evaluation and optimization of new anti-corrosion technology.

[0040] Example 2 In addition, based on the above-mentioned test system, the present invention also discloses a method for testing the high-temperature corrosion rate of water-cooled wall pipes in operation, which specifically includes the following steps: Set the temperature difference threshold range, and obtain the real-time temperature difference between the position of the test sample 22 and the outer wall temperature of the water-cooled wall tube 31 through the first temperature measuring component 21 and the second temperature measuring component 23; adjust the position of the test sample 22 inside the water-cooled wall, control the real-time temperature difference within the temperature difference threshold range, and keep the test sample 22 and the water-cooled wall tube 31 in the same operating condition, and take it out regularly to perform the high-temperature corrosion rate test of the water-cooled wall tube in operation. Perform the high-temperature corrosion rate test of the water-cooled wall tube in operation, specifically, after taking out the test sample 22, use multiple methods such as multi-point thickness measurement, weighing, electron microscope, etc. to measure the corrosion thinning amount, and calculate the corrosion thinning rate according to the test duration.

[0041] In the specific test method, the first step is to set a reasonable temperature difference threshold range. This step is crucial because it directly determines whether the test sample can accurately reflect the temperature conditions of the water-cooled wall tubes in actual operation, thereby affecting the test accuracy of the corrosion rate. According to the need for the accuracy of the test results, when the accuracy requirement is low, the temperature difference threshold range can be set within -50°C~50°C. When the real-time temperature difference between the position of the test sample 22 and the outer wall temperature of the water-cooled wall tube 31 is greater than 50°C, the test sample 22 is moved toward the outside of the water-cooled wall. When the real-time temperature difference between the position of the test sample 22 and the outer wall temperature of the water-cooled wall tube 31 is less than -50°C, the test sample 22 is moved toward the inside of the water-cooled wall. However, in order to further improve the accuracy of the test, the further preferred temperature difference threshold range is -20°C to 20°C, that is, when the real-time temperature difference between the position of the test sample 22 and the outer wall temperature of the water-cooled wall tube 31 is greater than 20°C, the test sample 22 is moved toward the outside of the water-cooled wall, and when the real-time temperature difference between the position of the test sample 22 and the outer wall temperature of the water-cooled wall tube 31 is less than -20°C, the test sample 22 is moved toward the inside of the water-cooled wall. This range ensures that the temperature difference between the test sample and the water-cooled wall tube is within a controllable and reasonable range, thereby improving the reliability of the test results.

[0042] In order to achieve real-time monitoring, the present invention adopts a first temperature measuring component 21 and a second temperature measuring component 23. The first temperature measuring component is responsible for measuring the real-time temperature of the water-cooled wall tube, while the second temperature measuring component is used to measure the real-time temperature of the position where the test sample is located. Through the coordinated work of these two temperature measuring components, the temperature difference between the water-cooled wall tube and the test sample can be obtained in real time, providing data support for subsequent position adjustment. After obtaining the real-time temperature difference, the next step is to adjust the position of the test sample according to the temperature difference. The purpose of the adjustment is to ensure that the test sample can be in the same temperature environment as the water-cooled wall tube, so as to more accurately simulate the corrosion conditions in actual operation. By accurately controlling the position of the test sample, the temperature difference between it and the water-cooled wall tube can be kept within the set temperature difference threshold range.

[0043] After the test specimen is in a stable operating state, the next step is to regularly remove it to test the high-temperature corrosion rate. The frequency and time interval of removal can be flexibly adjusted according to the actual operation of the boiler and the test requirements. After the test specimen is removed, chemical analysis, metallographic examination, electron microscope observation and other methods can be used to evaluate its corrosion. Through these test methods, the corrosion rate data of the test specimen in different time periods can be obtained, which provides a basis for subsequent data analysis and corrosion mechanism research.

[0044] The method of the present invention can significantly improve the accuracy of the test by setting a reasonable temperature difference threshold range and real-time monitoring of the temperature difference between the water-cooled wall tube and the test sample. Compared with the traditional offline test method, the present method can obtain the corrosion data of the boiler water-cooled wall tube in different time periods by regularly taking out the test sample and conducting corrosion rate tests. These data can provide strong support for the operation and maintenance strategy of the boiler. For example, the operating parameters of the boiler can be adjusted in time according to the changing trend of the corrosion rate to slow down the corrosion rate; at the same time, a reasonable maintenance plan can also be formulated according to the corrosion situation to ensure the safe operation of the boiler.

[0045] That is, the test method measures the wall temperature difference, that is, the real-time temperature difference between the water-cooled wall tube 31 and the position where the test sample 22 is located, and controls the insertion depth of the test sample 22 so that the real-time temperature difference between the water-cooled wall tube 31 and the position where the test sample 22 is located is within the set temperature difference threshold range, and keeps the test sample 22 and the water-cooled wall tube 31 in the same operating condition. As for the material of the test sample 22, a new tube of the same material as the water-cooled wall tube 31 or a discarded tube after leakage that has passed the inspection can be selected. It is necessary to ensure that the width of the test end of the tube is greater than 3mm and less than the width of the water-cooled wall fin 32, and more preferably greater than 3mm and 2mm less than the width of the water-cooled wall fin 32, to ensure that the test sample 22 is smoothly inserted and removed. As for the insertion depth of the test sample 22, it is preferred that the insertion depth of the test sample 22 is greater than half of the outer diameter of the water-cooled wall tube 31.

[0046] The present invention discloses a system and method for testing the high-temperature corrosion rate of water-cooled wall pipes in operation. The test system includes a test sample 22, on which a second temperature measuring component 23 is provided, a first temperature measuring component 21 on a water-cooled wall tube 31, and a position control component 24, wherein the position control component 24 is used to automatically adjust the insertion depth of the test sample 22. The test sample 22 is replaced regularly, and the corrosion thinning amount of the sample after corrosion can be measured by multiple methods such as multi-point thickness measurement, weighing, and electron microscopy, and the corrosion thinning rate is calculated according to the test duration. After establishing a test account, the corrosion thinning rate of the pipe associated with the operating conditions such as coal quality and oxygen content in the main combustion zone can be obtained. The test system can obtain the high-temperature corrosion thinning rate of the water-cooled wall pipes during operation, reduce the risk of thinning and leakage of the pipes caused by high-temperature corrosion, reduce the workload of setting up scaffolding to measure the high-temperature corrosion thinning rate during maintenance, reduce the cost of water-cooled wall maintenance and repair, and improve the operating efficiency and safety of pulverized coal boilers.

[0047] Example 3 A 1000MW supercritical opposed combustion boiler has three layers of burners. The side walls of the burner area are areas with higher high-temperature corrosion rates. The water-cooled wall fin spacing is 10mm. The water-cooled wall fin spacing here refers to the distance between the water-cooled wall fins and the water-cooled wall tubes on both sides. The outer diameter of the water-cooled wall tube in this embodiment is 63mm. The water-cooled wall tube high-temperature corrosion rate test system of the present invention is arranged on the side wall at a position 0.5m above each layer of burners on the left and right walls. The test system includes 3 test units 2, and the three test units 2 are evenly spaced above the burners. There are 9 test units 2 on the left wall and 9 test units 2 on the right wall, with a total of 18 test units 2. The insertion depth of the test sample 22 is 50mm, and the width of the test end of the test sample 22 is 8mm. The temperature difference between the test sample 22 and the water-cooled wall is set in the range of -20℃~20℃. When the deviation exceeds the set value, the insertion depth of the sample is automatically adjusted. If the real-time temperature difference between the water-cooled wall tube 31 and the position of the test sample 22 is greater than 20℃, the sample is automatically adjusted to move toward the outside of the furnace; if the real-time temperature difference between the water-cooled wall tube 31 and the position of the test sample 22 is less than -20℃, the sample is automatically adjusted to move toward the inside of the furnace.

[0048] Based on the same idea, changes in the layout height and number of the test unit 2 should be considered within the protection scope of this patent.

[0049] Example 4 A 3000MW subcritical four-corner tangential combustion boiler has a total of 6 layers of burners. The four walls of the burner area may be areas with high high-temperature corrosion rates. The spacing between the water-cooled wall fins is 10mm, and the outer diameter of the water-cooled wall tube is 63mm. At 0.5m above the 5th and 6th burners, at the center height of the SOFA burner and the 6th burner, there are three layers, and the downstream of the jet is located at 3 / 4 of the wall. A total of 12 sets of high-temperature corrosion rate measurement test systems are arranged. The depth of the test sample is 50mm, and the width of the test end of the test sample is 6mm. The threshold value of the temperature difference between the test sample and the water-cooled wall is set to ±30℃. The insertion depth of the sample is automatically adjusted when the deviation exceeds the set value. If the sample wall temperature minus the water-cooled wall temperature is greater than 30℃, the sample is automatically adjusted to move toward the outside of the furnace; when the sample wall temperature minus the water-cooled wall temperature is less than -30℃, the sample is automatically adjusted to move toward the inside of the furnace. In order to carry out the high-sulfur coal blending test, the sulfur content of the coal entering the furnace was kept unchanged for 24 hours during the test. The 2.5% sulfur coal was blended for 72 hours, and one sample was replaced every 24 hours; the 1% sulfur coal was blended for 72 hours, and one sample was replaced every 24 hours. The high-temperature corrosion thinning rate of each coal was calculated.

[0050] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high temperature corrosion rate test system for water wall pipes in operation, characterized in that: It comprises a control unit (1) and a plurality of test units (2); Any of the test units (2) comprises a first temperature measuring component (21) arranged on a water-cooled wall tube (31), and a test sample (22) passing through a water-cooled wall fin (32) and movably arranged in a vertical direction along the water-cooled wall fin (32), wherein a second temperature measuring component (23) is arranged on the test sample (22); The first temperature measuring component (21) and the second temperature measuring component (23) are both connected to the control unit (1).

2. A system for testing the high temperature corrosion rate of water-cooled wall pipes in operation according to claim 1, characterized in that: The water-cooling wall fin (32) is provided with a through hole (33); the test sample (22) passes through the through hole (33) and is movably arranged in a vertical direction along the water-cooling wall fin (32).

3. The high temperature corrosion rate testing system for water wall tubes in operation according to claim 1 is characterized in that: The test sample (22) and the water-cooling wall fin (32) are clearance-matched.

4. The high temperature corrosion rate testing system for water-cooled wall pipes in operation according to claim 1, characterized in that: A plurality of the test units (2) are arranged between the bottom burner and the burnout air nozzle; when the boiler is an opposed combustion boiler, the test units (2) are all located on the side walls; when the boiler is a tangential combustion boiler, the test units (2) are located downstream of the center line of each wall and the jet direction.

5. A system for testing the high temperature corrosion rate of water-cooled wall pipes in operation according to claim 4, characterized in that: When the boiler is an opposed-firing boiler, 1 to 3 test units (2) are evenly spaced apart on the single-sided water-cooled wall between the burners of adjacent layers.

6. The high temperature corrosion rate testing system for water wall tubes in operation according to claim 1 is characterized in that: Any one of the test samples (22) is connected to a position control component (24), and the position control component (24) is connected to the control unit (1).

7. The high temperature corrosion rate testing system for water wall tubes in operation according to claim 1 is characterized in that: The material of the test sample (22) is the same as the material of the water-cooled wall tube.

8. A method for testing the high temperature corrosion rate of water-cooled wall pipes in operation, characterized in that: Testing is performed by a testing system as described in any one of claims 1 to 7; The specific steps include: Setting a temperature difference threshold range, and obtaining a real-time temperature difference between the location of the test sample (22) and the outer wall temperature of the water-cooled wall tube (31) through a first temperature measuring component (21) and a second temperature measuring component (23); The position of the test sample (22) inside the water-cooled wall is adjusted to control the real-time temperature difference within the temperature difference threshold range, and the test sample (22) is kept running under the same operating conditions as the water-cooled wall tube (31), and is taken out regularly to perform a high-temperature corrosion rate test on the water-cooled wall tube during operation.

9. A method for testing the high temperature corrosion rate of water-cooled wall pipes in operation according to claim 8, characterized in that: The temperature difference threshold range is -50°C to 50°C.

10. A method for testing the high temperature corrosion rate of water-cooled wall pipes in operation according to claim 9, characterized in that: The position of the test sample (22) inside the water-cooled wall is adjusted to control the real-time temperature difference to be within the temperature difference threshold range, specifically: when the real-time temperature difference between the position of the test sample (22) and the outer wall temperature of the water-cooled wall tube (31) is greater than 50°C, the test sample (22) is moved toward the outside of the water-cooled wall; when the real-time temperature difference between the position of the test sample (22) and the outer wall temperature of the water-cooled wall tube (31) is less than -50°C, the test sample (22) is moved toward the inside of the water-cooled wall.

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