Flue corrosion-resistant coating temperature variation resistance inspection device and method

Abstract

The present application belongs to the technical field of power plant flue corrosion protection coating, and relates to a flue corrosion protection coating temperature change resistance inspection device and method. The device comprises a circulating fan, the outlet of the circulating fan is connected with a fifth electromagnetic valve and a sixth electromagnetic valve, the sixth electromagnetic valve is connected with a simulated flue, the simulated flue is connected with an eighth electromagnetic valve, the fifth electromagnetic valve and the seventh electromagnetic valve are connected with the inlet of a third air heating device, the outlet of the third air heating device is connected with a third electromagnetic valve and a fourth electromagnetic valve, the third electromagnetic valve is connected with the inlet of a second air heating device, the outlet of the second air heating device is connected with the inlet of a first air heating device, the outlet of the first air heating device is connected with a second electromagnetic valve, the fourth electromagnetic valve and the second electromagnetic valve are connected with a first electromagnetic valve, and the first electromagnetic valve is connected with the inlet of the circulating fan. The present application can evaluate the performance of the corrosion protection coating before the flue corrosion protection is implemented, so as to avoid the failure of the corrosion protection coating.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of power plant flue corrosion protection coating, and relates to a flue corrosion protection coating temperature change resistance inspection device and method. BACKGROUND

[0002] With the increasingly stringent environmental protection requirements of thermal power plants, harmful substances such as sulfur dioxide, sulfur trioxide and nitrogen oxides contained in the flue gas of coal-fired units have become key factors affecting the long-term stable operation of equipment. Acidic corrosive gases in the flue gas can cause strong corrosion on the surface of metal equipment, resulting in shortened service life of the unit equipment, and even causing safety hazards. In order to reduce the erosion of flue gas on metal flue and other equipment, corrosion protection coating has become one of the important means to ensure the normal operation of the unit.

[0003] However, with the development of new energy power generation technology, especially the 300MW coal-fired unit in thermal power plants gradually undertakes the task of peak regulation, and the start-stop machine is frequent, which brings new challenges to the use of corrosion protection coating. During the start-up and shutdown of the peak regulation unit of the thermal power plant, the temperature in the flue changes extremely violently, and the temperature fluctuation and cold-hot alternating effect of the flue gas put forward higher requirements for the temperature change resistance of the corrosion protection coating. When the temperature of the flue gas changes, the coating will be affected by thermal expansion and contraction, resulting in cracking, bubbling, peeling and other phenomena of the coating, and then causing the direct exposure of the metal surface, forming a corrosion channel, and finally leading to corrosion damage and leakage of the metal equipment, and even endangering the safe and stable operation of the unit.

[0004] In addition, since the coal-fired unit of the thermal power plant usually faces a relatively harsh working environment, the corrosion protection coating not only needs to withstand high temperature, high humidity and other environmental tests, but also needs to cope with the erosion of complex flue gas chemical composition on the coating. This makes the corrosion protection coating in design and use must have stronger high temperature resistance, acid and alkali corrosion resistance and long-term stability, in order to prevent greater maintenance cost, downtime and pollutant emission caused by coating failure.

[0005] Based on the above background, the temperature change resistance of the corrosion protection coating has become one of the key indicators to evaluate its reliability and effectiveness. In order to ensure that the corrosion protection coating can maintain stable performance in the environment with high temperature change, and avoid coating failure and metal corrosion caused by temperature fluctuation, it is urgent to develop a scientific and efficient inspection device and method to strictly test the temperature change resistance of the corrosion protection coating before application. SUMMARY

[0006] The purpose of the present application is to solve the problems in the prior art, and to provide a flue corrosion protection coating temperature change resistance inspection device and method, which can effectively test the temperature change resistance of the corrosion protection coating.

[0007] To achieve the above object, the present application adopts the following technical solutions to achieve the above object:

[0008] In the first aspect, the present application provides a flue corrosion-resistant coating temperature change resistance inspection device, comprising a circulating fan; the outlet of the circulating fan is connected with a fifth electromagnetic valve and a sixth electromagnetic valve respectively; the sixth electromagnetic valve is connected with a simulated flue; the simulated flue is connected with a seventh electromagnetic valve; the fifth electromagnetic valve and the seventh electromagnetic valve are both connected with the inlet of a third air heating device;

[0009] The outlet of the third air heating device is connected with a third electromagnetic valve and a fourth electromagnetic valve respectively; the third electromagnetic valve is connected with the inlet of a second air heating device; the outlet of the second air heating device is connected with the inlet of a first air heating device; the outlet of the first air heating device is connected with a second electromagnetic valve; the fourth electromagnetic valve and the second electromagnetic valve are both connected with a first electromagnetic valve; the first electromagnetic valve is connected with the inlet of the circulating fan.

[0010] Preferably, the inlet of the circulating fan is provided with an air suction electromagnetic valve.

[0011] Preferably, the simulated flue is provided with an exhaust electromagnetic valve.

[0012] Preferably, the first air heating device is provided with a first heating rod inside; the second air heating device is provided with a second heating rod inside; the third air heating device is provided with a third heating rod inside.

[0013] Preferably, the outlet of the circulating fan is provided with a first temperature sensor; the simulated flue is provided with a second temperature sensor.

[0014] Preferably, the simulated flue is provided with a hole; the hole is provided with a coating test piece.

[0015] Preferably, the device further comprises an intelligent control device; the circulating fan, the first temperature sensor, the first heating rod, the second temperature sensor, the first electromagnetic valve, the air suction electromagnetic valve, the second electromagnetic valve, the third electromagnetic valve, the fourth electromagnetic valve, the fifth electromagnetic valve, the sixth electromagnetic valve, the seventh electromagnetic valve, the exhaust electromagnetic valve, the second heating rod and the third heating rod are all electrically connected with the intelligent control device.

[0016] In the second aspect, the present application provides a flue corrosion-resistant coating temperature change resistance inspection method, comprising the following steps:

[0017] Single heating mode: air enters the fifth electromagnetic valve through the outlet of the circulating fan, is heated through the third air heating device, passes through the fourth electromagnetic valve, and then enters the inlet of the circulating fan through the first electromagnetic valve; the first temperature sensor monitors the circulating temperature, controls the power of the third heating rod, and stabilizes the circulating temperature at 95-105 DEG C; after the circulating temperature reaches the set temperature, the sixth electromagnetic valve and the seventh electromagnetic valve are opened, and the fifth electromagnetic valve is closed; the heated air passes through the simulated flue to heat the coating test piece; the second temperature sensor monitors the temperature value of the inner surface of the simulated flue, and when the set temperature value is reached, the air suction electromagnetic valve and the exhaust electromagnetic valve are opened, and the seventh electromagnetic valve is closed at the same time, cold air is sucked from the air suction electromagnetic valve, enters the simulated flue through the sixth electromagnetic valve, cools the coating test piece, and is then discharged from the exhaust electromagnetic valve, so that the coating test piece completes one cycle of cold and hot alternating temperature change.

[0018] Common heating mode: air enters the fifth electromagnetic valve through the outlet of the circulating fan, is heated through the third air heating device, and then passes through the third electromagnetic valve in turn through the second air heating device and the first air heating device; the air heated through the first air heating device enters the inlet of the circulating fan through the second electromagnetic valve and the first electromagnetic valve; the first temperature sensor monitors the circulating temperature, controls the power of the first heating rod, the second heating rod and the third heating rod, and stabilizes the circulating temperature at 195-205 DEG C; after the circulating temperature reaches the set temperature, the sixth electromagnetic valve and the seventh electromagnetic valve are opened, and the fifth electromagnetic valve is closed; the heated air passes through the simulated flue to heat the coating test piece; the second temperature sensor monitors the temperature value of the inner surface of the simulated flue, and when the set temperature value is reached, the air suction electromagnetic valve and the exhaust electromagnetic valve are opened, and the seventh electromagnetic valve is closed at the same time, cold air is sucked from the air suction electromagnetic valve, enters the simulated flue through the sixth electromagnetic valve, cools the coating test piece, and is then discharged from the exhaust electromagnetic valve, so that the coating test piece completes one cycle of cold and hot alternating temperature change.

[0019] Preferably, the single heating mode is used to test the coating test piece suitable for an environment below 80 DEG C.

[0020] Preferably, the common heating mode is used to test the coating test piece suitable for an environment below 160 DEG C.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] The present application realizes the circulation of air flow in the device through the circulating fan, heats the air through the air heating device, and can select different modes to heat the air through the opening and closing of the valve, so as to test the corrosion-resistant coating with different temperature requirements, improve the applicability of the device, and simulate the temperature, airflow and smoke composition of the actual flue of the power plant through the simulated flue, so as to provide a real test environment for the temperature change resistance of the corrosion-resistant coating.

[0023] Further, by controlling the opening and closing of the valve, the anticorrosive coating can be cooled or heated, so as to simulate the thermal stress in the actual working environment, and help to test the performance and stability of the coating under high temperature or low temperature conditions. The application can evaluate the performance of the anticorrosive coating before the flue anticorrosion is implemented, avoid the failure of the anticorrosive coating, and ensure the safe operation of the thermal power generating unit. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0025] Figure 1 FIG. 1 is a structural schematic diagram of a flue anticorrosive coating temperature variation resistance testing device according to the present application;

[0026] Wherein: 1, circulating fan; 2, first temperature sensor; 3, first air heating device; 4, second air heating device; 5, third air heating device; 6, first heating rod; 7, simulated flue; 8, coating test piece; 9, second temperature sensor; 10, first electromagnetic valve; 11, air suction electromagnetic valve; 12, second electromagnetic valve; 13, third electromagnetic valve; 14, fourth electromagnetic valve; 15, fifth electromagnetic valve; 16, sixth electromagnetic valve; 17, seventh electromagnetic valve; 18, exhaust electromagnetic valve; 19, second heating rod; 20, third heating rod. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, not all of the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of the present application.

[0029] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0030] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "horizontal", "inner" and the like indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, or the orientation or position relationship when the product of the present application is used, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only used for differentiation in description and cannot be understood as indicating or implying relative importance.

[0031] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0032] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, if the terms "arrangement", "installation", "connection", "connection" appear, they should be understood in a broad sense, for example, they can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or indirectly connected through an intermediate medium; can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0033] The present application will be described in further detail below with reference to the accompanying drawings:

[0034] A first object of the present application is to provide a flue corrosion-resistant coating temperature change resistance testing device, as shown in Figure 1 The outlet of the circulating fan 1 is connected with the fifth electromagnetic valve 15 and the sixth electromagnetic valve 16 respectively; the sixth electromagnetic valve 16 is connected with the simulated flue 7; the simulated flue 7 is connected with the seventh electromagnetic valve 17; the fifth electromagnetic valve 15 and the seventh electromagnetic valve 17 are both connected with the inlet of the third air heating device 5; the outlet of the third air heating device 5 is connected with the third electromagnetic valve 13 and the fourth electromagnetic valve 14 respectively; the third electromagnetic valve 13 is connected with the inlet of the second air heating device 4; the outlet of the second air heating device 4 is connected with the inlet of the first air heating device 3; the outlet of the first air heating device 3 is connected with the second electromagnetic valve 12; the fourth electromagnetic valve 14 and the second electromagnetic valve 12 are both connected with the first electromagnetic valve 10; the first electromagnetic valve 10 is connected with the inlet of the circulating fan 1.

[0035] The circulating fan 1 is responsible for the circulation of air flow inside the device, and by adjusting the speed of the air flow, it ensures that the air flows uniformly in the device. The first air heating device 3, the second air heating device 4, and the third air heating device 5 all have the function of heating air. By controlling the opening and closing of the valves, different modes can be selected to heat the air, such as heating the air only through the third air heating device 5 or heating the air through the first air heating device 3, the second air heating device 4, and the third air heating device 5 together. The simulated flue 7 is used to simulate the temperature, air flow, and flue gas composition of the actual thermal power plant flue. It simulates the working conditions in the flue, providing a real test environment for the temperature variation resistance of the corrosion-resistant coating. Secondly, by controlling the opening and closing of the valves, the corrosion-resistant coating can be cooled or heated, thereby simulating the thermal stress in the actual working environment, which helps to test the performance and stability of the coating under high or low temperature conditions.

[0036] The air suction electromagnetic valve 11 is provided at the inlet of the circulating fan 1, and the exhaust electromagnetic valve 18 is provided on the simulated flue 7. The air suction electromagnetic valve is used to suck in cold air to cool the corrosion-resistant coating, and the cold air is then discharged through the exhaust electromagnetic valve 18.

[0037] The first air heating device 3 is internally provided with a first heating rod 6; the second air heating device 4 is internally provided with a second heating rod 19; and the third air heating device 5 is internally provided with a third heating rod 20. The air heating device has a closed cylinder made of φ108×800mm stainless steel pipe, the heating rod is located in the middle of the closed cylinder, the top is sealed, the power of the heating rod is 5KW, and the heating rod realizes uniform heating of the air.

[0038] The first temperature sensor 2 is provided at the outlet of the circulating fan 1, and the second temperature sensor 9 is provided on the simulated flue 7. The first temperature sensor 2 can detect the gas temperature (i.e. the circulating temperature) at the outlet of the circulating fan 1 in real time, and the second temperature sensor 9 can monitor the gas temperature in the flue. By monitoring the temperature in real time, the heating power can be controlled to achieve the set test temperature. Preferably, the temperature sensor is a thermocouple temperature sensor.

[0039] Holes are provided on the simulated flue 7, and the coating test pieces 8 are provided in the holes. Specifically, the simulated flue 7 is surrounded by a stainless steel plate in the shape of a rectangular barrel, with dimensions of 150×150×800mm. Three 50×100mm holes are opened on each of the four vertical sides, and the coating test pieces 8 are installed in the holes, i.e. three coating test pieces 8 are installed on each side, and multiple test points can provide a more comprehensive understanding of the performance of the coating test pieces 8 at different positions, avoiding test deviations caused by a single test piece.

[0040] The number and size of the holes can also be adjusted according to experimental requirements to achieve more or fewer hole configurations to simulate different ventilation, flow rate or material transfer conditions. A temperature and humidity adjusting system is arranged inside the simulated flue 7 to accurately simulate the influence of different climate conditions on the coating test piece 8. Through the second temperature sensor 9 and the humidity adjusting system, the simulated environment can be more dynamic and variable, and closer to the actual application scenario. In addition, the application additionally provides an air flow control system (including a fan, a wind direction adjusting plate and an air flow control valve) in the simulated flue 7, which can accurately adjust the air flow speed, direction and turbulence to more accurately simulate the characteristics of the flue gas flow in different industrial applications. The rotation speed of the fan, the wind direction adjusting plate and the air flow control valve can be adjusted to simulate different flow modes of the flue gas in the actual environment.

[0041] The flue corrosion-resistant coating temperature change resistance testing device also comprises an intelligent control device; the circulating fan 1, the first temperature sensor 2, the first heating rod 6, the second temperature sensor 9, the first electromagnetic valve 10, the air suction electromagnetic valve 11, the second electromagnetic valve 12, the third electromagnetic valve 13, the fourth electromagnetic valve 14, the fifth electromagnetic valve 15, the sixth electromagnetic valve 16, the seventh electromagnetic valve 17, the exhaust electromagnetic valve 18, the second heating rod 19 and the third heating rod 20 are electrically connected with the intelligent control device. The intelligent control device can realize automatic control of the whole system, and improves the automation degree, accuracy, operability and safety of the device, and provides more efficient, accurate and reliable protection for the flue corrosion-resistant coating temperature change resistance testing.

[0042] The second object of the application is to provide a flue corrosion-resistant coating temperature change resistance testing method, comprising the following steps:

[0043] The single heating mode is as follows: air enters the fifth electromagnetic valve 15 through the outlet of the circulating fan 1, is heated by the third air heating device 5, passes through the fourth electromagnetic valve 14, enters the inlet of the circulating fan 1 through the first electromagnetic valve 10; the first temperature sensor 2 monitors the circulating temperature, controls the power of the third heating rod 20, and stabilizes the circulating temperature at 95-105 DEG C; after the circulating temperature reaches the set temperature, the sixth electromagnetic valve 16 and the seventh electromagnetic valve 17 are opened, and the fifth electromagnetic valve 15 is closed; the heated air passes through the simulated flue 7 to heat the coating test piece 8; the second temperature sensor 9 monitors the temperature value of the inner surface of the simulated flue 7, and when the set temperature value is reached, the air suction electromagnetic valve 11 and the exhaust electromagnetic valve 18 are opened, and the seventh electromagnetic valve 17 is closed, so that cold air is sucked in from the air suction electromagnetic valve 11, enters the simulated flue 7 through the sixth electromagnetic valve 16, cools the coating test piece 8, and is then discharged from the exhaust electromagnetic valve 18, so that the coating test piece 8 completes one cycle of cold-hot alternating temperature change;

[0044] Co-heating mode: air enters the fifth electromagnetic valve 15 through the outlet of the circulating fan 1, is heated through the third air heating device 5, and then passes through the third electromagnetic valve 13 in turn through the second air heating device 4 and the first air heating device 3; the air heated through the first air heating device 3 enters the inlet of the circulating fan 1 through the second electromagnetic valve 12 and the first electromagnetic valve 10; the first temperature sensor 2 monitors the circulating temperature, controls the power of the first heating rod 6, the second heating rod 19 and the third heating rod 20, and stabilizes the circulating temperature at 195~205℃; after the circulating temperature reaches the set temperature, the sixth electromagnetic valve 16 and the seventh electromagnetic valve 17 are opened, and the fifth electromagnetic valve 15 is closed; the heated air passes through the simulated flue 7 to heat the coating test piece 8; the second temperature sensor 9 monitors the temperature value of the inner surface of the simulated flue 7, and when the set temperature value is reached, the air suction electromagnetic valve 11 and the exhaust electromagnetic valve 18 are opened, and the seventh electromagnetic valve 17 is closed at the same time, cold air is sucked from the air suction electromagnetic valve 11, enters the simulated flue 7 through the sixth electromagnetic valve 16, cools the coating test piece 8, and is then discharged from the exhaust electromagnetic valve 18, so that the coating test piece 8 completes one cycle of alternating cold and hot temperature change.

[0045] Wherein, when the coating test piece 8 is tested in an environment below 80℃, an alternating cold and hot cycle of normal temperature and high temperature 95~105℃ is adopted, 3 cycles of testing are carried out, and a single heating mode is adopted. When the coating test piece 8 is tested in an environment below 160℃, an alternating cold and hot cycle of normal temperature and high temperature 195~205℃ is adopted, 3 cycles of testing are carried out, and a co-heating mode is adopted. The alternating cold and hot cycle can simulate the temperature fluctuation that the coating may experience in the actual use environment, especially the common diurnal temperature difference or temperature change in process operation. Through this test, the resistance of the coating to repeated thermal expansion and cold contraction can be evaluated.

[0046] Secondly, the device of the present application can also separately open the second air heating device 4 or the first air heating device 3 and the third air heating device 5 for co-heating, so as to reach different set temperatures. This on-demand heating design not only reduces the operating cost, but also meets the concept of green environmental protection.

[0047] For example, after three cycles of testing, the temperature change resistance of the coating is evaluated, which can be observed by a microscope. If the coating has no cracks, discoloration or delamination under the microscope, it indicates that the coating has good temperature change resistance. Before the flue is prevented from corrosion, the temperature change resistance of the coating is tested and evaluated, so that the possible deficiencies of the coating can be found early. The failure of the coating may cause the flue corrosion protection function to fail to play, and even may cause direct damage to the equipment. Through strict testing of the temperature change resistance of the coating, it can be ensured that the corrosion coating will not crack, fall off or discolor in a high temperature environment, so as to avoid the occurrence of coating failure accidents and ensure the safe operation of the thermal power generator set.

[0048] The above merely provides the preferred embodiments of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall fall within the scope of protection of the present application.

Claims

1. A device for testing the temperature change resistance of flue anticorrosive coating, characterized in that: The circulating fan (1) comprises a circulating fan (1); the outlet of the circulating fan (1) is respectively connected to a fifth solenoid valve (15) and a sixth solenoid valve (16); the sixth solenoid valve (16) is connected to a simulated flue (7); the simulated flue (7) is connected to a seventh solenoid valve (17); the fifth solenoid valve (15) and the seventh solenoid valve (17) are both connected to an inlet of a third air heating device (5); The outlet of the third air heating device (5) is connected to the third solenoid valve (13) and the fourth solenoid valve (14) respectively; the third solenoid valve (13) is connected to the inlet of the second air heating device (4); the outlet of the second air heating device (4) is connected to the inlet of the first air heating device (3); the outlet of the first air heating device (3) is connected to the second solenoid valve (12); the fourth solenoid valve (14) and the second solenoid valve (12) are both connected to the first solenoid valve (10); the first solenoid valve (10) is connected to the inlet of the circulation fan (1); The inlet of the circulating fan (1) is provided with an air suction solenoid valve (11); The simulated flue (7) is provided with an exhaust solenoid valve (18); The simulated flue (7) is provided with a hole; a coating test piece (8) is provided in the hole.

2. A flue anti-corrosion coating temperature change resistance testing device according to claim 1, characterized in that: A first heating rod (6) is provided inside the first air heating device (3); a second heating rod (19) is provided inside the second air heating device (4); and a third heating rod (20) is provided inside the third air heating device (5).

3. A flue anti-corrosion coating temperature change resistance testing device according to claim 2, characterized in that: The outlet of the circulating fan (1) is provided with a first temperature sensor (2); and the simulated flue (7) is provided with a second temperature sensor (9).

4. A flue anti-corrosion coating temperature change resistance testing device according to claim 3, characterized in that: It also includes an intelligent control device; the circulating fan (1), the first temperature sensor (2), the first heating rod (6), the second temperature sensor (9), the first solenoid valve (10), the air intake solenoid valve (11), the second solenoid valve (12), the third solenoid valve (13), the fourth solenoid valve (14), the fifth solenoid valve (15), the sixth solenoid valve (16), the seventh solenoid valve (17), the exhaust solenoid valve (18), the second heating rod (19) and the third heating rod (20) are all electrically connected to the intelligent control device.

5. A method for testing the temperature change resistance of flue anticorrosion coating, characterized in that: The device for testing the temperature change resistance of the flue anticorrosive coating according to any one of claims 3 or 4 is used, comprising the following steps: Single heating mode: air enters the fifth solenoid valve (15) through the outlet of the circulating fan (1), passes through the fourth solenoid valve (14) after being heated by the third air heating device (5), and then passes through the first solenoid valve (10) to enter the inlet of the circulating fan (1); the first temperature sensor (2) monitors the circulating temperature and controls the power of the third heating rod (20) to stabilize the circulating temperature at 95~105℃; when the circulating temperature reaches the set temperature, the sixth solenoid valve (16) and the seventh solenoid valve (17) are opened, and the fifth solenoid valve (15) is closed; the heated air passes through the The coating test piece (8) is heated by passing through the simulated flue (7); the second temperature sensor (9) monitors the temperature value of the inner surface of the simulated flue (7); when the temperature reaches the set temperature value, the air intake solenoid valve (11) and the exhaust solenoid valve (18) are opened, and the seventh solenoid valve (17) is closed at the same time, and cold air is sucked in from the air intake solenoid valve (11), passes through the sixth solenoid valve (16) and enters the simulated flue (7), cools the coating test piece (8), and is then discharged from the exhaust solenoid valve (18), so that the coating test piece (8) completes a hot and cold alternating temperature change; Common heating mode: air enters the fifth solenoid valve (15) through the outlet of the circulating fan (1), is heated by the third air heating device (5), and then passes through the third solenoid valve (13) and the second air heating device (4) and the first air heating device (3) in sequence; the air heated by the first air heating device (3) passes through the second solenoid valve (12) and the first solenoid valve (10) and enters the inlet of the circulating fan (1); the first temperature sensor (2) monitors the circulating temperature and controls the power of the first heating rod (6), the second heating rod (19) and the third heating rod (20) to stabilize the circulating temperature at 195~205℃; after the circulating temperature reaches the set temperature, the first solenoid valve (12) is turned on. The sixth solenoid valve (16) and the seventh solenoid valve (17) are opened, and the fifth solenoid valve (15) is closed; the heated air passes through the simulated flue (7) to heat the coating test piece (8); the second temperature sensor (9) monitors the temperature value of the inner surface of the simulated flue (7), and when the set temperature value is reached, the air intake solenoid valve (11) and the exhaust solenoid valve (18) are opened, and the seventh solenoid valve (17) is closed at the same time, and cold air is sucked in from the air intake solenoid valve (11), passes through the sixth solenoid valve (16) and enters the simulated flue (7), cools the coating test piece (8), and is then discharged from the exhaust solenoid valve (18), so that the coating test piece (8) completes a hot and cold alternating temperature change.

6. A method for testing the temperature change resistance of flue anticorrosion coating according to claim 5, characterized in that: The single heating mode is used to test a coating test piece (8) in an applicable environment below 80°C.

7. A method for testing the temperature change resistance of flue anticorrosion coating according to claim 5, characterized in that: The common heating mode is used to test a coating test piece (8) in an applicable environment below 160°C.

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