A system and method for evaluating the corrosion resistance of a coating

Abstract

The present application relates to the technical field of coating corrosion resistance research, and particularly relates to a coating corrosion resistance evaluation system and method. The evaluation system comprises a gas supply unit, an experiment unit, a refrigeration unit and a test unit. The gas supply unit is used to supply target flue gas to the experiment unit. The experiment unit comprises a shell and an experiment table arranged in the shell. A plurality of test pieces and target fly ash covering the test pieces are arranged on the experiment table. An internal cavity is arranged in the experiment table. The test pieces comprise a metal substrate and a coating layer coated on the metal substrate. The refrigeration unit is used to introduce refrigeration medium into the cavity to condense the target flue gas above the target fly ash, thereby forming a simulated corrosion environment of a waste incineration system coupled with condensed flue gas and deposited fly ash. After the target flue gas is condensed, the test unit is used to perform electrochemical testing and adhesion testing on the test pieces to evaluate the corrosion resistance of the coating layer in the simulated corrosion environment.

Description

Technical Field

[0001] This invention relates to the field of coating corrosion resistance research technology, and in particular to an evaluation system and method for coating corrosion resistance. Background Technology

[0002] Waste incineration flue gas is rich in HCl and SO2. X Acidic gases and water vapor can easily condense at the tail ends of devices such as economizers, deacidification towers, dust collectors, and chimneys, causing corrosion and even rupture of the inner pipe walls. This seriously affects the safe operation of the waste incineration system. On the other hand, the waste incinerator has low waste heat utilization, requiring further reduction of its flue gas temperature, but this exacerbates the risk of dew point corrosion. Therefore, it is urgent to implement corrosion protection measures for the target inner pipe walls of the waste incineration system (i.e., the inner pipe walls at the tail ends of devices such as economizers, deacidification towers, dust collectors, and chimneys).

[0003] In related technologies, corrosion protection measures typically employ coating protection. Coating protection offers advantages such as good protective effect, simplicity, wide selectivity, and ease of integration with other methods, making it one of the most widely used methods for protecting modern industrial materials. Currently commonly used coatings include organic coatings, metallic coatings, and organic-inorganic composite coatings. These coatings primarily work by isolating the material from direct contact with the external environment, forming a protective layer on the metal surface to shield against the penetration of corrosive media, thereby extending the service life of the inner pipe wall.

[0004] Therefore, there is an urgent need for an evaluation system and method for the corrosion resistance of coatings to effectively evaluate the corrosion resistance of various coatings. Summary of the Invention

[0005] This invention provides a system and method for evaluating the corrosion resistance of coatings, which can effectively evaluate the corrosion resistance of various coatings.

[0006] In a first aspect, embodiments of the present invention provide an evaluation system for the corrosion resistance of a coating, comprising a gas supply unit, an experimental unit, a refrigeration unit, and a testing unit, wherein:

[0007] The gas supply unit is used to supply target flue gas to the experimental unit. The target flue gas is waste incineration flue gas or flue gas with the same composition as the waste incineration flue gas.

[0008] The experimental unit includes an outer shell and an experimental platform disposed within the outer shell. The gas supply unit is connected to the outer shell. Multiple test specimens and target fly ash covering the multiple test specimens are disposed on the experimental platform. The experimental platform has an internal cavity. The target fly ash is waste incineration fly ash or fly ash with the same composition as waste incineration fly ash. The test specimens include a metal substrate and a coating on the metal substrate. The temperature of the target flue gas above the target fly ash is 150-200°C.

[0009] The refrigeration unit is connected to the cavity and is used to introduce a refrigeration medium into the cavity to condense the target flue gas located above the target fly ash, thereby forming a simulated corrosion environment for the waste incineration system in which condensed flue gas and deposited fly ash are coupled; wherein, the temperature of the coating and the metal substrate are both 30 to 150°C.

[0010] After the target flue gas condenses, the testing unit is used to perform electrochemical and adhesion tests on the test specimen to evaluate the corrosion resistance of the coating under the simulated corrosion environment.

[0011] Secondly, embodiments of the present invention provide a method for evaluating the corrosion resistance of a coating, based on the coating corrosion resistance evaluation system described in the above embodiments, the method comprising:

[0012] The gas supply unit is used to supply the target flue gas to the experimental unit;

[0013] The refrigeration unit introduces a cooling medium into the cavity to condense the target flue gas located above the target fly ash, thereby forming a simulated corrosive environment for the waste incineration system where condensed flue gas and deposited fly ash are coupled.

[0014] After the target flue gas condenses, the test unit is used to perform electrochemical and adhesion tests on the test specimen to evaluate the corrosion resistance of the coating under the simulated corrosion environment.

[0015] As described above, the coating corrosion resistance evaluation system and method provided by this invention involves setting up multiple test specimens and target fly ash covering them on an experimental platform. When the gas supply unit supplies target flue gas to the experimental unit, the temperature of the target flue gas above the target fly ash is 150-200°C. Therefore, a cooling unit introduces a cooling medium into the cavity, condensing the target flue gas above the target fly ash. This creates a simulated corrosion environment of a waste incineration system on the experimental platform, where condensed flue gas and deposited fly ash are coupled. After the target flue gas condenses, the test unit performs electrochemical and adhesion tests on the test specimens to evaluate the corrosion resistance of the coating under the simulated corrosion environment. Therefore, the above scheme can more realistically reflect the corrosion resistance of the coating in an actual waste incineration system, thus providing a theoretical basis for the practical selection of coatings with excellent corrosion resistance. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the structure of a coating corrosion resistance evaluation system provided in one embodiment of the present invention;

[0018] Figure 2 for Figure 1 The diagram shows the structure of the test bench in the coating corrosion resistance evaluation system.

[0019] Figure 3 This is a flowchart illustrating a method for evaluating the corrosion resistance of a coating according to an embodiment of the present invention.

[0020] Figure label:

[0021] 10-Box;

[0022] 1-Gas supply unit;

[0023] 11-First gas supply subunit;

[0024] 111 - Buffer tank;

[0025] 112 - First mass flow meter;

[0026] 113 - First shut-off valve;

[0027] 12 - Second gas supply subunit;

[0028] 121 - Injection pump;

[0029] 122 - Carrier gas cylinder;

[0030] 123-Second Mass Flow Meter

[0031] 124 - Second shut-off valve;

[0032] 125 - Atomizer;

[0033] 2-Experimental Unit;

[0034] 21-Outer shell;

[0035] 211-First shell;

[0036] 212 - Second shell;

[0037] 22-Experimental table;

[0038] 221-Cavity;

[0039] 222-groove;

[0040] 23 - Test specimen;

[0041] 231 - Metallic matrix;

[0042] 232 - Coating;

[0043] 24-Target fly ash;

[0044] 3-Refrigeration unit;

[0045] 31-Insulated chamber;

[0046] 32-Circulating pump;

[0047] 4-Test Unit;

[0048] 41-Electrochemical Testing Subunit;

[0049] 411-Electrochemical Workstation;

[0050] 412 - Reference electrode;

[0051] 413 - Counter electrode;

[0052] 414 - Conductor;

[0053] 42-Adhesion testing subunit;

[0054] 5-Exhaust gas treatment unit;

[0055] 61-Controller;

[0056] 62 - First temperature sensor;

[0057] 63 - Second temperature sensor;

[0058] 64 - Third temperature sensor. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] Please see Figure 1 One embodiment of the present invention provides an evaluation system for the corrosion resistance of a coating, comprising an air supply unit 1, an experimental unit 2, a refrigeration unit 3, and a testing unit 4, wherein:

[0061] Gas supply unit 1 is used to supply target flue gas to experimental unit 2. The target flue gas is waste incineration flue gas or flue gas with the same composition as waste incineration flue gas.

[0062] Experimental unit 2 includes an outer shell 21 and an experimental platform 22 disposed inside the outer shell 21. Gas supply unit 1 is connected to the outer shell 21. Multiple test specimens 23 and target fly ash 24 covering the multiple test specimens 23 are disposed on the experimental platform 22. The interior of the experimental platform 22 is provided with a cavity 221. The target fly ash 24 is waste incineration fly ash or fly ash with the same composition as waste incineration fly ash. The test specimens 23 include a metal substrate 231 and a coating 232 coated on the metal substrate 231. The temperature of the target flue gas above the target fly ash 24 is 150-200℃.

[0063] The refrigeration unit 3 is connected to the cavity 221. The refrigeration unit 3 is used to introduce a refrigeration medium into the cavity 221 to condense the target flue gas located above the target fly ash 24, thereby forming a simulated corrosion environment for the waste incineration system where the condensed flue gas and the deposited fly ash are coupled. The temperature of the coating 232 and the metal substrate 231 is 30 to 150°C.

[0064] After the target flue gas condenses, test unit 4 is used to perform electrochemical and adhesion tests on the test specimen 23 to evaluate the corrosion resistance of coating 232 in a simulated corrosion environment.

[0065] In this embodiment, multiple test specimens 23 and target fly ash 24 covering the test specimens 23 are set on the experimental bench 22. When the gas supply unit 1 supplies target flue gas to the experimental unit 2, the temperature of the target flue gas above the target fly ash 24 is 150-200°C. Therefore, the cooling unit 3 introduces a cooling medium into the cavity 221, which condenses the target flue gas above the target fly ash 24. This creates a simulated corrosion environment of a waste incineration system on the experimental bench 22, where condensed flue gas and deposited fly ash are coupled. After the target flue gas condenses, the testing unit 4 performs electrochemical and adhesion tests on the test specimens 23 to evaluate the corrosion resistance of the coating 232 under the simulated corrosion environment. Therefore, the above scheme can more realistically reflect the corrosion resistance of the coating in an actual waste incineration system, thus providing a theoretical basis for the actual selection of coatings with excellent corrosion resistance.

[0066] In one embodiment of the present invention, the gas supply unit 1 includes:

[0067] The first gas supply subunit 11 includes a buffer tank 111, a first mass flow meter 112, and a second shut-off valve 124 connected in sequence. The buffer tank 111 is used to connect to the waste incineration system to receive the waste incineration flue gas generated by the waste incineration system. The second shut-off valve 124 is connected to the outer casing 21.

[0068] The second gas supply subunit 12 includes an injection pump 121, a carrier gas cylinder 122, a second mass flow meter 123, a second shut-off valve 124, and an atomizer 125. The injection pump 121 is connected to the first inlet end of the atomizer 125. The carrier gas cylinder 122, the second mass flow meter 123, and the second shut-off valve 124 are connected in sequence. The second shut-off valve 124 is connected to the second inlet end of the atomizer 125. The outlet end of the atomizer 125 is connected to the outer casing 21. The injection pump 121 contains a mixed solution of dilute HCl and dilute H2SO4 at a preset concentration. The carrier gas cylinder 122 contains a mixed gas of N2, O2, and SO2 in a preset ratio. The mixed solution and the mixed gas are mixed in the atomizer 125 and form a flue gas at the outlet end of the atomizer 125.

[0069] In this embodiment, by setting up a first air supply subunit 11 and a second air supply subunit 12, the evaluation system can be applied to both laboratory and waste incineration sites, thus improving its flexibility. By setting up a buffer tank 111, the flow rate of the waste incineration flue gas from the waste incineration system can be effectively reduced, thus avoiding impact on the target fly ash 24 and facilitating subsequent effective evaluation of the coating's corrosion resistance. By setting up the second air supply subunit 12, which includes an injection pump 121, a carrier gas cylinder 122, a second mass flow meter 123, a second shut-off valve 124, and an atomizer 125, the proportions of the components in the configured flue gas can be ensured to be closer to the actual proportions of the components in waste incineration flue gas, allowing for more accurate simulation of the operating conditions of waste incineration flue gas flowing through the inner walls of different targets. For example, the proportion of acidic gases in the waste incineration flue gas before and after passing through the deacidification tower is very different. By precisely controlling the liquid output of the injection pump 121 and the gas output of the carrier gas cylinder 122, the operating conditions of different waste incineration flue gas can be accurately simulated.

[0070] It should be noted that the preset concentration and preset ratio mentioned above are to be adaptively selected by the operator during actual experiments, and the specific values ​​are not limited in this embodiment of the invention.

[0071] Please see Figure 2 In one embodiment of the present invention, the experimental platform 22 is provided with a groove 222 (it should be noted that, in order to simplify the structure of the experimental platform 22, Figure 1 The groove 222 is not shown, but this does not mean that the test bench 22 does not have a groove. Multiple test specimens 23 and the target fly ash 24 covering the multiple test specimens 23 are all located in the groove 222. This ensures that even if the incoming flue gas has a certain momentum, the target fly ash 24 will not be blown outside the test bench 22 by the incoming flue gas, thus ensuring the accuracy of the coating corrosion resistance evaluation experiment. Of course, the surface of the target fly ash 24 should not exceed the top surface of the test bench 22.

[0072] In one embodiment of the present invention, the surface of the target fly ash 24 is a horizontal plane, the bottom surface of the target fly ash 24 is in contact with the experimental table 22, and the height of the surface of the target fly ash 24 above the surface of the coating 232 is 0.1 to 2 cm.

[0073] In this embodiment, by selecting a height from the surface of the target fly ash 24 to the surface of the coating 232 within the range of 0.1 to 2 cm, it is beneficial to accurately simulate the thickness of the fly ash adhering to the inner wall of the actual target pipe, thereby ensuring the accuracy of the evaluation experiment on the corrosion resistance performance of the coating.

[0074] Of course, the surface of the target fly ash 24 may not be a horizontal surface, such as a curved surface, but this embodiment of the invention does not limit it.

[0075] In one embodiment of the present invention, the target fly ash 24 comprises at least one of the following: NaCl, KCl, CaO, CaCO3, MgO, K2O, Na2O, Al2O3, Fe2O3, CaSO4, CaSO3, Na2SO4, K2SO4, Ca(OH)2, and SiO2.

[0076] In this embodiment, the components of the target fly ash 24 are all the main components of waste incineration fly ash. By reasonably preparing and configuring the fly ash or directly selecting waste incineration fly ash generated by the waste incineration system, it is beneficial to accurately simulate the composition of fly ash adhering to the inner wall of the actual target, thereby ensuring the accuracy of the evaluation experiment on the corrosion resistance performance of the coating.

[0077] In one embodiment of the present invention, the particle size of the target fly ash 24 is selected from any of the following numerical ranges: 0-1 μm, 1-10 μm, 10-50 μm, 50-100 μm, 100-250 μm, 250-1000 μm.

[0078] In this embodiment, the particle size of the target fly ash 24 is within the main particle size range of waste incineration fly ash. Therefore, by changing the particle size of the target fly ash 24 to conduct the evaluation experiment, it is beneficial to accurately simulate the particle size of the fly ash attached to the inner wall of the actual target (i.e., the particle size of the fly ash attached to the inner wall of different targets is different, for example, the particle size of the fly ash before and after the dust collector is very different). This can ensure the accuracy of the evaluation experiment on the corrosion resistance performance of the coating.

[0079] In one embodiment of the present invention, coating 232 is an organic coating, a metallic coating, or an organic-inorganic composite coating. The specific type of coating 232 is not limited in this embodiment. Furthermore, the specific compositions of organic coatings, metallic coatings, and organic-inorganic composite coatings are well known to those skilled in the art and will not be described in detail here.

[0080] Please continue reading. Figure 1 In one embodiment of the present invention, the evaluation system further includes an exhaust gas treatment unit 5, which is connected to the outer shell 21 (specifically, to the second shell 212). The exhaust gas treatment unit 5 is provided with a sodium hydroxide solution or a solid absorbent to absorb the acidic gases remaining in the target flue gas.

[0081] In some embodiments, the solid absorbent may be activated carbon; however, the composition of the solid absorbent is not limited in this embodiment of the invention.

[0082] In one embodiment of the present invention, the test specimen 23 is cylindrical, and the test unit 4 includes:

[0083] The electrochemical testing subunit 41 includes an electrochemical workstation 411, a reference electrode 412, and a counter electrode 413. The test specimen 23 is connected to the electrochemical workstation 411 via a wire 414. The reference electrode 412 and the counter electrode 413 are both connected to the electrochemical workstation 411 via wires 414. The reference electrode 412 and the counter electrode 413 are inserted into the target fly ash 24 above one of the test specimens 23 (without contacting the coating 232, but should be as close to the coating 232 as possible).

[0084] The adhesion testing subunit 42 is used to perform adhesion testing on at least one of the other test specimens 23.

[0085] In this embodiment, by setting the test specimen 23 as a cylindrical structure, it is convenient to perform adhesion testing on the test specimen 23 (because the test structure of the adhesion testing subunit 42 is a cylindrical structure). By setting multiple test specimens 23, it can be ensured that when one test specimen 23 is undergoing electrochemical testing, at least one of the other test specimens 23 can be simultaneously subjected to adhesion testing, thereby improving testing efficiency.

[0086] In some embodiments, electrochemical testing includes electrochemical impedance spectroscopy and electrochemical noise testing. However, this embodiment of the invention does not limit the specific items of electrochemical testing.

[0087] Understandably, in order to ensure that the test specimen 23 can be effectively tested for electrochemical purposes, it is necessary to perform treatments such as coating, polishing, cleaning, and drying. Specifically, the metal substrate 231 is first soldered to the wire 414, then coated with epoxy resin, polished with metallographic sandpaper, degreased with acetone, cleaned with anhydrous ethanol, and then dried before use.

[0088] In one embodiment of the present invention, the evaluation system further includes a housing 10. All units or subunits in the evaluation system except for the adhesion testing subunit 42 can be integrated into the housing 10, thereby improving the integration of the evaluation system and enabling the evaluation system to be used both in the laboratory and at the waste incineration site.

[0089] In one embodiment of the present invention, the outer shell 21 includes a first shell 211 and a second shell 212 connected in sequence. The gas supply unit 1 is connected to the first shell 211. The interiors of the first shell 211 and the second shell 212 are connected. The experimental platform 22 is disposed inside the second shell 212. A first electric heating sleeve (not shown in the figure) is disposed on the outside of the first shell 211, and a second electric heating sleeve (not shown in the figure) is disposed on the outside of the second shell 212. The heating temperature of the first electric heating sleeve is 200-300°C, and the heating temperature of the second electric heating sleeve is 150-200°C.

[0090] In this embodiment, by setting the heating temperature of the first electric heating jacket to 200–300°C, this temperature range can basically ensure that dilute HCl and dilute H2SO4 can be completely evaporated, thus ensuring that the flue gas is formed at the outlet of the atomizer 125. Setting the heating temperature of the second electric heating jacket to 150–200°C can further adjust the flue gas temperature to accurately simulate the actual working conditions of waste incineration flue gas.

[0091] It should be noted that if the target flue gas is selected from waste incineration flue gas, the first electric heating sleeve may not be provided on the outside of the first housing 211, while the second electric heating sleeve is preferably provided on the outside of the second housing 212. Of course, the second electric heating sleeve may also not be provided on the outside of the second housing 212, and this embodiment of the invention does not limit this.

[0092] In one embodiment of the present invention, the evaluation system further includes a controller 61 and a first temperature sensor 62, a second temperature sensor 63 and a third temperature sensor 64 electrically connected to the controller 61 respectively. The first temperature sensor 62 is disposed inside the second housing 212 and close to the first housing 211 to detect the flue gas temperature when the target flue gas is discharged through the first housing 211 in real time. The second temperature sensor 63 is used to detect the temperature of the metal substrate 231 in real time, and the third temperature sensor 64 is used to detect the temperature of the coating 232 in real time.

[0093] The controller 61 is electrically connected to the first electric heating jacket and the refrigeration unit 3 respectively. The controller 61 is used to adjust the heating temperature of the first electric heating jacket according to the temperature detected by the first temperature sensor 62 and the first preset temperature. The controller 61 is also used to adjust the temperature and flow rate of the refrigerant according to the temperature detected by the second temperature sensor 63 and the third temperature sensor 64 and the second preset temperature.

[0094] In this embodiment, by setting up a controller 61 and a first temperature sensor 62, a second temperature sensor 63 and a third temperature sensor 64 electrically connected to the controller 61 respectively, the temperature of the target flue gas and the temperature of flue gas condensation can be precisely controlled, thereby accurately simulating different working conditions of the target inner pipe wall in the waste incineration system.

[0095] In some embodiments, the refrigeration unit 3 includes a constant temperature chamber 31, a circulation pipeline connecting the constant temperature chamber 31 and the cavity 221, and a circulation pump 32 disposed on the circulation pipeline. By adjusting the temperature and flow rate of the cooling medium, the temperature of the metal substrate 231 and the coating 232 is adjusted, thereby condensing the panel flue gas. Specifically, by adjusting the temperature and flow rate of the cooling medium, the temperature of the metal substrate 231 and the coating 232 can be precisely adjusted from 30 to 150°C with an accuracy of ±1°C, thus facilitating the study of the corrosion resistance performance of the coating at different temperatures.

[0096] In some embodiments, the cooling medium can be water, oil, liquid nitrogen, etc., but the type of cooling medium is not limited in this embodiment of the invention.

[0097] It should be noted that the adjustment strategies for the first preset temperature, the heating temperature of the first electric heating jacket, the second preset temperature, and the temperature and flow rate of the refrigerant are all adaptively selected by the operator during actual testing. In this embodiment of the invention, the specific values ​​and adjustment strategies are not limited.

[0098] The specific working process of the above evaluation system is described below:

[0099] The metal substrate 231 of the test specimen 23, which is prepared into a standard diameter cylindrical structure, is welded to the wire 414, then sealed with epoxy resin, polished with metallographic sandpaper, degreased with acetone, cleaned with anhydrous ethanol, and dried. The test specimen 23 is then placed in the groove 222 of the experimental table 22, and the target fly ash 24 is spread evenly on the test specimen 23. The reference electrode 412 and the counter electrode 413 are inserted into the target fly ash 24 but do not contact the coating 232. In laboratory mode, the concentrations of dilute hydrochloric acid and dilute sulfuric acid are calculated according to the required HCl, SO3, and water vapor content of the waste incineration flue gas, and the mixed acid solution is prepared. The flow rate of the injection pump 121 is adjusted, and the carrier gas flow rate is adjusted using the second mass flow meter 123. The temperature of the first electric heating jacket is set higher than the boiling point of the mixed acid solution to ensure that the acid solution can evaporate completely. The set temperature of the first electric heating jacket is adjusted by the flue gas temperature measured by the first temperature sensor 62 and the first preset temperature. Set the temperature of the second electric heating jacket; in on-site mode, directly introduce the waste incineration flue gas generated from the waste incineration system into the buffer tank 111, control its flow rate using the first mass flow meter 112, and set the temperature of the second heating jacket; determine the set temperature of the constant temperature chamber 31 and the set flow rate of the circulating pump 32, and further adjust the temperature and flow rate of the cooling medium according to the temperature detected by the second temperature sensor 63 and the third temperature sensor 64, so as to condense the target flue gas; after the acidic gas in the target flue gas condenses, turn on the electrochemical workstation 411 to perform in-situ electrochemical tests on the test specimen 23 after different times, including electrochemical impedance spectroscopy, electrochemical noise testing, etc., and simultaneously take out other test specimens 23 and directly measure their interface adhesion using the adhesion testing subunit 42 (e.g., adhesion tester), and quantitatively evaluate the corrosion resistance of the coating in the simulated waste incineration system corrosion environment by comprehensively considering both electrochemical performance and interface adhesion.

[0100] Furthermore, one embodiment of the present invention also provides a method for evaluating the corrosion resistance of a coating, based on the coating corrosion resistance evaluation system mentioned in any of the above embodiments, the method comprising:

[0101] Step S1: Supply target flue gas to experimental unit 2 using gas supply unit 1;

[0102] Step S2: Use the refrigeration unit 3 to introduce a refrigeration medium into the cavity 221 to condense the target flue gas located above the target fly ash 24, thereby forming a simulated corrosion environment of the waste incineration system where condensed flue gas and deposited fly ash are coupled.

[0103] Step S3: After the target flue gas condenses, the test unit 4 is used to perform electrochemical tests and adhesion tests on the test specimen 23 to evaluate the corrosion resistance performance of the coating 232 in a simulated corrosion environment.

[0104] It should be noted that this method and the coating corrosion resistance evaluation system in the above embodiments are based on the same inventive concept, and therefore have the same beneficial effects. The beneficial effects of the method will not be elaborated here.

[0105] It should be noted that, in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0106] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A system for evaluating the corrosion resistance of a coating, characterized in that, It includes a gas supply unit (1), an experimental unit (2), a refrigeration unit (3), and a testing unit (4), wherein: The gas supply unit (1) is used to supply target flue gas to the experimental unit (2), and the target flue gas is waste incineration flue gas or flue gas with the same composition as the waste incineration flue gas. The experimental unit (2) includes an outer shell (21) and an experimental platform (22) disposed inside the outer shell (21). The gas supply unit (1) is connected to the outer shell (21). The experimental platform (22) is provided with multiple test specimens (23) and target fly ash (24) covering the multiple test specimens (23). The interior of the experimental platform (22) is provided with a cavity (221). The target fly ash (24) is waste incineration fly ash or fly ash with the same composition as the waste incineration fly ash. The test specimen (23) includes a metal substrate (231) and a coating (232) coated on the metal substrate (231). The temperature of the target flue gas above the target fly ash (24) is 150℃~200℃. The refrigeration unit (3) is connected to the cavity (221). The refrigeration unit (3) is used to introduce a refrigeration medium into the cavity (221) to condense the target flue gas located above the target fly ash (24), thereby forming a simulated corrosion environment of the waste incineration system in which condensed flue gas and deposited fly ash are coupled. The temperature of the coating (232) and the metal substrate (231) is 30℃~150℃. After the target flue gas is condensed, the test unit (4) is used to perform electrochemical tests and adhesion tests on the test specimen (23) to evaluate the corrosion resistance of the coating (232) in the simulated corrosion environment. The experimental table (22) is provided with a groove (222), and multiple test specimens (23) and target fly ash (24) covering multiple test specimens (23) are located in the groove (222). The surface of the target fly ash (24) is horizontal, the bottom surface of the target fly ash (24) is in contact with the experimental table (22), the surface of the target fly ash (24) exceeds the surface of the coating (232) by 0.1cm to 2cm, and the surface of the target fly ash (24) does not exceed the top surface of the experimental table (22). The outer shell (21) includes a first shell (211) and a second shell (212) connected in sequence. The gas supply unit (1) is connected to the first shell (211). The interiors of the first shell (211) and the second shell (212) are connected. The experimental platform (22) is located inside the second shell (212). A first electric heating sleeve is provided on the outside of the first shell (211), and a second electric heating sleeve is provided on the outside of the second shell (212). The heating temperature of the first electric heating sleeve is 200℃~300℃, and the heating temperature of the second electric heating sleeve is 150℃~200℃.

2. The evaluation system for the corrosion resistance of coatings according to claim 1, characterized in that, The gas supply unit (1) includes: The first gas supply subunit (11) includes a buffer tank (111), a first mass flow meter (112) and a first shut-off valve (113) connected in sequence. The buffer tank (111) is used to connect to the waste incineration system to receive the waste incineration flue gas generated by the waste incineration system. The first shut-off valve (113) is connected to the outer shell (21). The second gas supply subunit (12) includes an injection pump (121), a carrier gas cylinder (122), a second mass flow meter (123), a second shut-off valve (124), and an atomizer (125). The injection pump (121) is connected to the first inlet end of the atomizer (125). The carrier gas cylinder (122), the second mass flow meter (123), and the second shut-off valve (124) are connected in sequence. The second shut-off valve (124) is connected to the second inlet end of the atomizer (125). The outlet end of the atomizer (125) is connected to the outer casing (21). The injection pump (121) is provided with a mixed solution of dilute HCl and dilute H2SO4 of a preset concentration. The carrier gas cylinder (122) is provided with a mixed gas of N2, O2, and SO2 of a preset ratio. The mixed solution and the mixed gas are mixed in the atomizer (125) and form the configured flue gas at the outlet end of the atomizer (125).

3. The evaluation system for the corrosion resistance of coatings according to claim 1, characterized in that, The target fly ash (24) comprises at least one of the following components: NaCl, KCl, CaO, CaCO3, MgO, K2O, Na2O, Al2O3, Fe2O3, CaSO4, CaSO3, Na2SO4, K2SO4, Ca(OH)2, SiO2.

4. The evaluation system for the corrosion resistance of coatings according to claim 1, characterized in that, The particle size of the target fly ash (24) is selected from any of the following numerical ranges: 0μm~1μm, 1μm~10μm, 10μm~50μm, 50μm~100μm, 100μm~250μm, 250μm~1000μm.

5. The evaluation system for the corrosion resistance of coatings according to claim 1, characterized in that, The coating (232) is an organic coating, a metal coating, or an organic-inorganic composite coating; And / or, It also includes an exhaust gas treatment unit (5), which is connected to the outer casing (21). The exhaust gas treatment unit (5) is provided with sodium hydroxide solution or solid absorbent to absorb the acidic gas remaining in the target flue gas.

6. The evaluation system for the corrosion resistance of coatings according to claim 1, characterized in that, The test specimen (23) is cylindrical, and the test unit (4) includes: The electrochemical testing subunit (41) includes an electrochemical workstation (411), a reference electrode (412), and a counter electrode (413). The test specimen (23) is connected to the electrochemical workstation (411) via a wire (414). The reference electrode (412) and the counter electrode (413) are both connected to the electrochemical workstation (411) via wires (414). The reference electrode (412) and the counter electrode (413) are inserted into the target fly ash (24) above one of the test specimens (23). The adhesion testing subunit (42) is used to perform adhesion testing on at least one of the other test specimens (23).

7. The evaluation system for the corrosion resistance of coatings according to claim 1, characterized in that, It also includes a controller (61) and a first temperature sensor (62), a second temperature sensor (63) and a third temperature sensor (64) electrically connected to the controller (61). The first temperature sensor (62) is disposed inside the second housing (212) and close to the first housing (211) to detect the flue gas temperature when the target flue gas is discharged through the first housing (211) in real time. The second temperature sensor (63) is used to detect the temperature of the metal substrate (231) in real time. The third temperature sensor (64) is used to detect the temperature of the coating (232) in real time. The controller (61) is electrically connected to the first electric heating jacket and the refrigeration unit (3) respectively. The controller (61) is used to adjust the heating temperature of the first electric heating jacket according to the temperature detected by the first temperature sensor (62) and the first preset temperature. The controller (61) is also used to adjust the temperature and flow rate of the refrigeration medium according to the temperature detected by the second temperature sensor (63) and the third temperature sensor (64) and the second preset temperature.

8. A method for evaluating the corrosion resistance of a coating, characterized in that, The evaluation system for the corrosion resistance of coatings based on any one of claims 1-7, the method comprising: The target flue gas is supplied to the experimental unit (2) using the gas supply unit (1); The refrigeration unit (3) is used to introduce a refrigeration medium into the cavity (221) to condense the target flue gas located above the target fly ash (24), thereby forming a simulated corrosive environment of the waste incineration system in which condensed flue gas and deposited fly ash are coupled. After the target flue gas is condensed, the test unit (4) is used to perform electrochemical tests and adhesion tests on the test specimen (23) to evaluate the corrosion resistance of the coating (232) in the simulated corrosion environment.

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