A component-adjustable dew point corrosion experiment system and method

Abstract

The application discloses a dew point corrosion experiment system and method with adjustable components, and the experiment system comprises a flue gas generating module, a flue gas outlet of the flue gas generating module is connected with a flue gas inlet of a corrosion platform or a flue gas inlet of a sulfuric acid content measuring device; the flue gas generating module comprises a standard gas cylinder and a syringe pump, an outlet end of the standard gas cylinder is connected with an inlet end of a gas washing bottle; saturated concentrated sulfuric acid is contained in the gas washing bottle; an outlet end of the syringe pump is connected with an inlet end of an evaporator, distilled water is contained in the syringe pump; the outlet end of the evaporator is connected with the inlet end of the corrosion platform or the inlet end of the sulfuric acid content measuring device; a connecting pipeline is arranged between the outlet end of the evaporator and the outlet end of the gas washing bottle and the corrosion platform, the connecting pipeline is a three-way pipeline, a heat tracing belt is wound outside the connecting pipeline; and the gas washing bottle is arranged in a thermostat.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of material corrosion performance experiment, and particularly relates to a dew point corrosion experiment system and method with adjustable components. BACKGROUND

[0002] In the field of coal-fired power generation, improving the efficiency of power station boilers is a key measure to reduce carbon emissions. Reducing the flue gas temperature is the most effective means to improve the efficiency of power station boilers. Among the heat losses of the boiler, the largest loss is the flue gas heat loss, and the energy of this part of loss is mainly carried out of the furnace by the flue gas, accounting for about 70% to 80% of the heat loss of the boiler. For every 10-20℃ increase in flue gas temperature, the thermal efficiency of the boiler decreases by 0.6% to 1.0%. The actual flue gas temperature of boilers in China is about 150℃, and there is still great potential for utilization. Reducing the flue gas temperature not only improves the efficiency of the boiler, but also improves the dust removal efficiency. However, too low a flue gas temperature will cause acid condensation in the flue gas, resulting in corrosion of the low-temperature heating surface. Therefore, it is necessary to study the corrosion resistance of the low-temperature heating surface material of the boiler. China's power coal contains a large amount of sulfur elements, which generates sulfur dioxide after combustion, and generates sulfur trioxide after high-temperature catalytic oxidation, and forms sulfuric acid with water vapor. The sulfuric acid dew point of the flue gas of the coal-fired boiler is high in content, and compared with other acid substances, the condensation of sulfuric acid has the greatest impact on the low-temperature heating surface of the boiler.

[0003] The research methods of low-temperature corrosion can be roughly divided into four types: immersion experiment, polarization curve method, laboratory simulation experiment and field corrosion experiment. Dew point corrosion is a process of electrochemical and chemical corrosion of materials under acid liquid film, and it not only needs an electrolyte solution but also needs the participation of an oxidizing atmosphere. Therefore, the corrosion mechanism of acid immersion experiment and polarization curve method is obviously different, resulting in lower reliability of the results. The opportunity for field corrosion experiment is relatively small, and if there is no large number of parallel experiments as a basis, it will be easy to have errors, resulting in that the experimental conclusion is not universal. Therefore, people turn their efforts to laboratory simulation experiments, and the difficulty of the experiment lies in the fact that the boiling point of sulfuric acid is relatively high, which makes it difficult to accurately control the content of sulfuric acid in the flue gas.

[0004] Chinese invention patent application with publication number CN109916807A disclosed a method for generating simulated gas for studying sulfuric acid dew point corrosion on June 21, 2019. The method uses a specially designed evaporation bottle to prepare flue gas, and it is proposed that the evaporation amount of 18.4 mol / L sulfuric acid is the most stable. However, since there is no separate water vapor generating device, if more water vapor content is needed in the flue gas, the sulfuric acid concentration needs to be reduced, which will cause the sulfuric acid evaporation amount to be unstable, and it is impossible to balance the stability of the sulfuric acid evaporation amount and the water vapor content in the flue gas at the same time. At the same time, the method for measuring the sulfuric acid vapor content using the conductivity of the absorption liquid can only reflect the high and low of the sulfate ion content, and cannot accurately calculate the specific content of sulfuric acid in the flue gas. The specific content of sulfuric acid in the simulated flue gas is not measured, and the influence of water vapor is not considered.

[0005] Chinese invention patent application with publication number CN115078241A disclosed a dew point corrosion experimental device and method for simulating low concentration sulfuric acid environment on September 20, 2022. The corrosion rate of the sample is accelerated by using an electrode. The method uses sulfuric acid evaporation, but does not specify the concentration of sulfuric acid used, and does not consider the influence of water content.

[0006] Chinese utility model patent application with publication number CN204556467U disclosed a test device for simulating sulfuric acid dew point on August 12, 2015. The test chamber is designed as multiple units with adjustable temperature to realize tests at different temperatures and shorten the test period. However, the units of the test chamber are in series, and the sulfuric acid content in the flue gas is continuously reduced, so that the true results cannot be obtained.

[0007] Chinese invention patent application with publication number CN101876622A disclosed an experimental device and test method for simulating sulfuric acid dew point corrosion on November 3, 2010. The atmosphere condition of the experimental system is sulfuric acid and water vapor, and there is no other atmosphere. The corrosion platform uses an air cooling method to control the temperature. This method does not create a flowing flue gas environment, but more like a fixed bed experiment.

[0008] The main problems of the existing methods are as follows: 1. The sulfuric acid content carried in the flue gas cannot be determined and has poor stability, and it is difficult to change different sulfuric acid concentration conditions; 2. The influence of different water vapor contents on sulfuric acid condensation and metal corrosion is not considered. SUMMARY

[0009] The purpose of the present application is to overcome the problem that the existing dew point corrosion experimental device cannot change the sulfuric acid concentration and water vapor content, and a component adjustable dew point corrosion experimental system and method are proposed.

[0010] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0011] The adjustable component dew point corrosion experiment system comprises a flue gas generating module, the flue gas generating module is provided with a flue gas outlet, the flue gas outlet is connected with a corrosion platform or a sulfuric acid content measuring device, the corrosion platform and the sulfuric acid content measuring device are both provided with a flue gas inlet, and the flue gas outlet is connected with the flue gas inlet.

[0012] The flue gas generating module comprises a standard gas cylinder and a syringe pump, the outlet end of the standard gas cylinder is connected with the inlet end of a gas washing bottle, when the flue gas outlet of the flue gas generating module is connected with the flue gas inlet of the corrosion platform, the standard gas cylinder is filled with non-condensable gas of flue gas, when the flue gas outlet of the flue gas generating module is connected with the flue gas inlet of the sulfuric acid content measuring device, the standard gas cylinder is filled with nitrogen; the gas washing bottle contains saturated concentrated sulfuric acid; the outlet end of the syringe pump is connected with the inlet end of an evaporator, the syringe pump is filled with distilled water; the outlet end of the evaporator is connected with the outlet end of the gas washing bottle, and the outlet end of the evaporator is connected with the inlet end of the corrosion platform or the inlet end of the sulfuric acid content measuring device; the outlet end of the corrosion platform is connected with a tail gas treatment device.

[0013] A connecting pipeline is arranged between the outlet end of the evaporator and the outlet end of the gas washing bottle and the corrosion platform, the connecting pipeline is a three-way pipeline, and a heating belt is wound outside the connecting pipeline; the gas washing bottle is arranged in a thermostat.

[0014] Further, a pressure reducing valve and a flow meter are sequentially connected between the outlet end of the standard gas cylinder and the inlet end of the gas washing bottle.

[0015] Further, the sulfuric acid content measuring device comprises a PH measuring instrument and a beaker, the beaker contains distilled water, and the measuring end of the PH measuring instrument is arranged in the distilled water.

[0016] Further, the corrosion platform comprises a glass tube, a support is arranged in the glass tube, the flue gas inlet of the corrosion platform is arranged at the upper end of the glass tube, the flue gas outlet of the corrosion platform is arranged at the lower end of the glass tube, the metal sample is placed on the support, a thermostat heater is arranged outside the glass tube, the top end of the support is hollow, and the metal sample is 3-5 cm away from the flue gas inlet of the corrosion platform.

[0017] Further, a plurality of metal samples are arranged, and the plurality of metal samples are uniformly arranged.

[0018] Further, the non-condensable gas of flue gas comprises oxygen, nitrogen, carbon dioxide and sulfur dioxide.

[0019] Further, the connecting pipeline is made of a high-temperature-resistant sulfuric acid corrosion-resistant material, and the high-temperature-resistant sulfuric acid corrosion-resistant material comprises polytetrafluoroethylene.

[0020] An adjustable component dew point corrosion experiment method is provided, which utilizes the adjustable component dew point corrosion experiment system, and comprises the following steps.

[0021] The flue gas is generated by using a flue gas generation module, the sulfuric acid content in the flue gas is measured by using a sulfuric acid content measuring device, the sulfuric acid content measuring device is replaced by a corrosion platform, and the corrosion experiment is performed by using the corrosion platform and the tail gas in the experiment is treated by using a tail gas treatment device.

[0022] Further, the corrosion experiment performed by using the corrosion platform specifically comprises:

[0023] The connecting pipeline is heated by opening the heat tracing band, and the temperature of the heat tracing band is higher than the temperature of the constant temperature box;

[0024] The parameters of the flow meter are set, the calibration gas cylinder is opened, and the non-condensable gas in the flue gas is introduced into the gas washing cylinder by adjusting the pressure reducing valve;

[0025] The saturated concentrated sulfuric acid in the gas washing cylinder is heated and stirred by opening the constant temperature box to generate a sulfuric acid solution and flue gas, and the flue gas is introduced into the inlet of the corrosion platform; the gas outlet in the gas washing cylinder is below the liquid level of the saturated concentrated sulfuric acid or the sulfuric acid solution;

[0026] The flow of the injection pump is set, and the injection pump is started to inject distilled water into the evaporator to generate water vapor, and the water vapor is introduced into the inlet of the corrosion platform;

[0027] The metal sample is placed on the support and the constant temperature heater is opened to corrode the metal sample;

[0028] The constant temperature box is closed at the end of the experiment, and the heat tracing band and the calibration gas cylinder are closed after the sulfuric acid solution in the gas washing cylinder is cooled.

[0029] Further, the measurement of the sulfuric acid content in the flue gas by using the sulfuric acid content measuring device specifically comprises:

[0030] The connecting pipeline is heated by the heat tracing band, and the temperature of the heat tracing band is higher than the temperature of the constant temperature box;

[0031] The parameters of the flow meter are set, the calibration gas cylinder is opened, and nitrogen is introduced into the gas washing cylinder by adjusting the pressure reducing valve;

[0032] The saturated concentrated sulfuric acid in the gas washing cylinder is heated and stirred by opening the constant temperature box to generate a sulfuric acid solution and sulfuric acid vapor, and the outlet of the nitrogen in the gas washing cylinder is below the liquid level of the saturated concentrated sulfuric acid or the sulfuric acid solution, and the outlet of the sulfuric acid vapor of the sulfuric acid content measuring device is below the liquid level of the distilled water;

[0033] The PH value of the solution after the distilled water absorbs the sulfuric acid vapor is measured, and the average value is obtained by repeating several times, and the solution volume is recorded;

[0034] The constant temperature box is closed at the end of the experiment, and the heat tracing band and the calibration gas cylinder are closed after the sulfuric acid solution in the gas washing cylinder is cooled.

[0035] The sulfuric acid content in the flue gas is calculated by measuring the sulfuric acid content collected in the distilled water, and the calculation formula is as follows:

[0036]

[0037] wherein ppm (H2SO4) - average content of H2SO4 in flue gas during the period from t1 to t2;

[0038] PH1 - PH value of the solution in the beaker at t1;

[0039] PH2 - PH value of the solution in the beaker at t2;

[0040] V1 - volume of the solution in the beaker at t1;

[0041] V2 - volume of the solution in the beaker at t2;

[0042] t - time;

[0043] qv - gas volume flow.

[0044] Compared with the prior art, the present application has the following beneficial technical effects:

[0045] The component-adjustable dew point corrosion experiment system provided by the present application has the following beneficial technical effects:

[0046] The component-adjustable dew point corrosion experiment method provided by the present application has the following beneficial technical effects:

[0047] The component-adjustable dew point corrosion experiment method provided by the present application has the following beneficial technical effects: BRIEF DESCRIPTION OF DRAWINGS

[0048] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and serve to explain the principles of the application. The drawings are illustrative of various embodiments of the application and are not therefore to be considered to be limiting of the scope of the application.

[0049] Figure 1 It is a schematic diagram of the overall device of the component-adjustable dew point corrosion experiment system of the application.

[0050] Figure 2 It is a front view of the corrosion platform of the component-adjustable dew point corrosion experiment system of the application.

[0051] Figure 3 It is a top view of the corrosion platform of the component-adjustable dew point corrosion experiment system of the application.

[0052] Figure 4 It is a schematic diagram of the sulfuric acid content measuring device of the component-adjustable dew point corrosion experiment system of the application.

[0053] In the figure, 1 is a standard gas cylinder, 2 is a pressure reducing valve, 3 is a flow meter, 4 is a syringe pump, 5 is an evaporator, 6 is a gas washing bottle, 7 is a thermostat, 8 is a corrosion platform, 801 is a metal sample, 802 is a support, 803 is a constant temperature heater, 804 is a glass tube, 805 is a corrosion platform inlet, 806 is a corrosion platform outlet, 9 is a tail gas treatment device, 10 is distilled water, 11 is a pH measuring instrument, 12 is a beaker, and 13 is a heating band. DETAILED DESCRIPTION

[0054] In order to enable persons skilled in the art to better understand the application scheme, the technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by persons skilled in the art without creative labor should fall within the protection scope of the application.

[0055] It should be noted that the terms "first", "second", and the like in the specification and claims of the application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to the process, method, product or device.

[0056] Embodiment one

[0057] Referring to Figure 1 , Figure 2 , Figure 3 and Figure 4 , a component-adjustable dew point corrosion experiment system comprises a flue gas generating module, the flue gas generating module is provided with a flue gas outlet, the flue gas outlet is connected to a corrosion platform 8 or a sulfuric acid content measuring device, the corrosion platform 8 and the sulfuric acid content measuring device are both provided with a flue gas inlet, and the flue gas outlet is connected to the flue gas inlet;

[0058] The flue gas generating module comprises a standard gas cylinder 1 and a syringe pump 4, the outlet end of the standard gas cylinder 1 is connected to the inlet end of a gas washing bottle 6, when the flue gas outlet of the flue gas generating module is connected to the flue gas inlet of the corrosion platform 8, the standard gas cylinder 1 contains non-condensable gas of flue gas, when the flue gas outlet of the flue gas generating module is connected to the flue gas inlet of the sulfuric acid content measuring device, the standard gas cylinder 1 contains nitrogen; the gas washing bottle 6 contains saturated concentrated sulfuric acid; the outlet end of the syringe pump 4 is connected to the inlet end of an evaporator 5, the syringe pump 4 contains distilled water; the outlet end of the evaporator 5 is connected to the outlet end of the gas washing bottle 6, and the outlet end of the gas washing bottle 6 is connected to the inlet end of the corrosion platform 8 or the inlet end of the sulfuric acid content measuring device; the outlet end of the corrosion platform 8 is connected to a tail gas treatment device 9;

[0059] A connecting pipeline is installed between the outlet end of the evaporator 5 and the outlet end of the gas washing bottle 6 and the corrosion platform 8, the connecting pipeline is a three-way pipeline, and a heat tracing belt 13 is wound outside the connecting pipeline; the gas washing bottle 6 is arranged in a thermostat 7.

[0060] Preferably, a pressure reducing valve 2 and a flow meter 3 are connected in sequence between the outlet end of the standard gas cylinder 1 and the inlet end of the gas washing bottle 6.

[0061] Preferably, the sulfuric acid content measuring device comprises a PH measuring instrument 11 and a beaker 12, the beaker 12 contains distilled water 10, and the measuring end of the PH measuring instrument 11 is arranged in the distilled water 10.

[0062] Preferably, the corrosion platform 8 comprises a glass tube 804, a support 802 is arranged inside the glass tube 804, the flue gas inlet of the corrosion platform 8 is arranged at the upper end of the glass tube 804, the flue gas outlet of the corrosion platform 8 is arranged at the lower end of the glass tube 804, the metal sample 801 is placed on the support 802, a thermostat heater 803 is installed outside the glass tube 804, the top end of the support 802 is hollow, and the metal sample 801 is 3-5 cm away from the flue gas inlet of the corrosion platform 8.

[0063] Preferably, a plurality of metal samples 801 are arranged, and the plurality of metal samples 801 are evenly arranged.

[0064] Preferably, the non-condensable gases of the flue gas include oxygen, nitrogen, carbon dioxide and sulfur dioxide.

[0065] Preferably, the connecting pipe is made of high-temperature and sulfuric acid corrosion resistant material, and the high-temperature and sulfuric acid corrosion resistant material includes polytetrafluoroethylene.

[0066] A component-adjustable dew point corrosion experiment method uses the above-mentioned component-adjustable dew point corrosion experiment system and includes the following steps:

[0067] The flue gas is generated by using the flue gas generation module, the sulfuric acid content in the flue gas is measured by using the sulfuric acid content measuring device, the sulfuric acid content measuring device is replaced by the corrosion platform 8, the corrosion experiment is performed by using the corrosion platform 8, and the tail gas in the experiment is treated by using the tail gas treatment device 9.

[0068] Preferably, the corrosion experiment performed by using the corrosion platform 8 specifically includes:

[0069] The heat tracing belt 13 is turned on to heat the connecting pipe, and the temperature of the heat tracing belt 13 is higher than the temperature of the thermostat 7;

[0070] The parameters of the flow meter 3 are set, the calibration gas cylinder 1 is opened, and the non-condensable gases of the flue gas are introduced into the gas washing bottle by adjusting the pressure reducing valve 2;

[0071] The saturated concentrated sulfuric acid in the gas washing bottle 6 is heated and stirred by using the thermostat 7 to generate a sulfuric acid solution and flue gas, and the flue gas is introduced into the corrosion platform inlet 805; the gas path outlet in the gas washing bottle 6 is lower than the liquid level of the saturated concentrated sulfuric acid or the sulfuric acid solution;

[0072] The flow of the injection pump 4 is set, and the injection pump 4 is turned on to inject distilled water into the evaporator to generate water vapor, and the water vapor is introduced into the corrosion platform inlet 805;

[0073] The metal sample 801 is placed on the bracket 802, and the thermostat heater 803 is turned on to corrode the metal sample 801;

[0074] After the experiment is completed, the thermostat 7 is turned off, and after the sulfuric acid solution in the gas washing bottle 6 is cooled, the heat tracing belt and the calibration gas cylinder 1 are turned off.

[0075] Preferably, the sulfuric acid content in the flue gas is measured by using the sulfuric acid content measuring device, and the sulfuric acid content measuring device is replaced by the corrosion platform 8.

[0076] The connecting pipe is heated by using the heat tracing belt 13, and the temperature of the heat tracing belt 13 is higher than the temperature of the thermostat 7;

[0077] The parameters of the flow meter 3 are set, the calibration gas cylinder 1 is opened, and nitrogen is introduced into the gas washing bottle 6 by adjusting the pressure reducing valve 2.

[0078] The saturated concentrated sulfuric acid in the washing bottle 6 is heated and stirred in the thermostat 7 to generate sulfuric acid solution and sulfuric acid vapor, the outlet of the nitrogen gas in the washing bottle 6 is lower than the liquid level of the saturated concentrated sulfuric acid or the sulfuric acid solution, and the sulfuric acid vapor outlet of the sulfuric acid content measuring device is lower than the liquid level of the distilled water 10;

[0079] The PH value of the solution after the distilled water 10 absorbs the sulfuric acid vapor is measured, and the average value is recorded after repeating several times;

[0080] The thermostat 7 is turned off at the end of the experiment, and the heat tracing band and the standard gas cylinder 1 are turned off after the sulfuric acid solution in the washing bottle 6 is cooled;

[0081] The sulfuric acid content in the flue gas is calculated by measuring the sulfuric acid content collected in the distilled water, and the calculation formula is as follows:

[0082]

[0083] Among them, ppm (H2SO4) is the average content of H2SO4 in the flue gas during the period from t1 to t2;

[0084] PH1 is the PH value of the solution in the beaker at t1;

[0085] PH2 is the PH value of the solution in the beaker at t2;

[0086] V1 is the solution volume in the beaker at t1;

[0087] V2 is the solution volume in the beaker at t2;

[0088] t is time;

[0089] qv is the gas volume flow.

[0090] Example two

[0091] A component-adjustable dew point corrosion experiment system as shown in Figure 1 、 Figure 2 、 Figure 3 and Figure 4 , including a flue gas generating module, a corrosion platform and a sulfuric acid content measuring device, wherein the flue gas generating module includes a standard gas cylinder 1, a pressure reducing valve 2, a flow meter 3, a syringe pump 4, an evaporator 5, a washing bottle 6, and a thermostat 7.

[0092] The standard gas cylinder 1 is filled with non-condensable gases of boiler flue gas, such as oxygen, nitrogen, carbon dioxide and sulfur dioxide; the washing bottle 6 is filled with saturated concentrated sulfuric acid; and the syringe pump 4 is filled with distilled water.

[0093] The outlet of the evaporator 5 and the outlet of the gas washing bottle 6 are connected with the corrosion platform 8, and the connecting pipeline needs to use high-temperature-resistant and sulfuric acid-resistant materials, such as polytetrafluoroethylene, and the connecting pipeline is wrapped with a heating belt 13 for heating to maintain the pipeline temperature higher than the evaporation temperature to prevent sulfuric acid from condensing.

[0094] The corrosion platform 8 comprises metal samples 801, supports 802, constant temperature heaters 803, glass tubes 804, a corrosion platform inlet 805, and a corrosion platform outlet 806. The flue gas enters from the upper end of the corrosion platform and flows out from the lower end. The metal samples 801 are placed 3-5 cm away from the corrosion platform inlet 805, and each metal sample 801 is uniformly placed. The top end of the support 802 is hollowed out.

[0095] The corrosion platform outlet 806 is connected with the tail gas treatment device 9. The tail gas treatment device uses sodium hydroxide to absorb sulfuric acid, sulfur dioxide, and carbon dioxide in the flue gas, and retains nitrogen and oxygen.

[0096] The sulfuric acid content measuring device comprises distilled water 10, a PH measuring instrument 11, and a beaker 12.

[0097] Before the experiment, the sulfuric acid content in the flue gas needs to be measured, and the corrosion platform 8 is replaced with the sulfuric acid content measuring device.

[0098] The standard gas cylinder 1 is connected with the pressure reducing valve 2, the flow meter 3, and the gas washing bottle 6 in sequence and introduced into the corrosion platform 8. The injection pump 4 is connected with the evaporator 5 and introduced into the corrosion platform 8. The gas washing bottle is placed in the constant temperature box 7.

[0099] The specific operation process of the one-component adjustable dew point corrosion experiment method using the one-component adjustable dew point corrosion experiment system for simulating flue gas corrosion experiments is as follows:

[0100] 1) Turn on the heating belt 13 to heat the connecting pipeline. In order to prevent sulfuric acid from condensing on the pipeline, the temperature of the heating belt 13 needs to be slightly higher than the temperature of the electric heating constant temperature box 7;

[0101] 2) Place the metal samples 801 uniformly on the supports 802 in the corrosion platform 8, set the temperature of the constant temperature heater 803, and start heating;

[0102] 3) Set the parameters of the flow meter 3 to introduce the gas;

[0103] 4) Turn on the electric heating constant temperature box 7 to heat the saturated concentrated sulfuric acid in the gas washing bottle 6;

[0104] 5) Set the flow of the injection pump 4 and turn on the injection pump 4;

[0105] Before the corrosion experiment, the sulfuric acid content carried in the flue gas needs to be measured.

[0106] The sulfuric acid content measurement method is as follows:

[0107] Experimental procedure:

[0108] 1) Turn on the heat tracing band 13 to heat the connecting pipeline, control the temperature of the heat tracing band 13 to be slightly higher than the temperature of the electric heating constant temperature box 7;

[0109] 2) Set the parameters of the flow meter 3, open the calibration gas cylinder 1 and adjust the pressure reducing valve 2;

[0110] 3) Turn on the electric heating constant temperature box 803 to heat the saturated concentrated sulfuric acid in the gas washing bottle 6;

[0111] 4) After stirring for 10 s, measure the pH value of the sulfuric acid solution, the above operation is carried out for 3 times to take the average value, and the solution volume is recorded;

[0112] 5) After the experiment, turn off the electric heating constant temperature box, close the heat tracing band after the sulfuric acid solution in the gas washing bottle is cooled, close the gas cylinder, and the gas outlet needs to be always immersed below the liquid level during the period.

[0113] The sulfuric acid content in the flue gas is calculated by measuring the sulfuric acid content collected in the distilled water, and the specific formula is:

[0114]

[0115] Where ppm (H2SO4) is the average content of H2SO4 in the flue gas during the period from t1 to t2;

[0116] PH1 is the pH value of the solution in the beaker at t1;

[0117] PH2 is the pH value of the solution in the beaker at t2;

[0118] V1 is the solution volume in the beaker at t1, L;

[0119] V2 is the solution volume in the beaker at t2, L;

[0120] t is the time, min;

[0121] qv is the gas volume flow, L / min.

[0122] During the measurement of the sulfuric acid content, the solution obtained by the distilled water absorbing sulfuric acid vapor has room temperature and low sulfuric acid mass fraction, so the sulfuric acid vapor can be completely absorbed by the distilled water, and no tail gas treatment is needed.

[0123] The process of the corrosion experiment is as follows:

[0124] 1) Turn on the heat tracing band to heat the pipeline, control the heat tracing band temperature to be slightly higher than the electric heating constant temperature box temperature;

[0125] 2) Set up the flow meter parameters, open the gas cylinder and adjust the pressure reducing valve;

[0126] 3) Open the electric heating constant temperature box to heat the sulfuric acid in the washing gas cylinder;

[0127] 4) Place the metal sample evenly on the support in the corrosion platform, and open the constant temperature heater;

[0128] 5) After the experiment, close the electric heating constant temperature box, close the gas cylinder after the sulfuric acid solution in the washing gas cylinder cools down, and the gas outlet needs to be always immersed below the liquid level.

[0129] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit the scope of protection, although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that: after reading the present application, those skilled in the art can still make various changes, modifications or equivalent replacements to the specific embodiments of the present application, but these changes, modifications or equivalent replacements are all within the scope of protection of the claims of the present application.

Claims

1. A component adjustable dew point corrosion test system, comprising: The smoke generation module is provided with a smoke outlet connected to a corrosion platform (8) or a sulfuric acid content measuring device, and the corrosion platform (8) and the sulfuric acid content measuring device are both provided with a smoke inlet, and the smoke outlet is connected to the smoke inlet. The smoke generation module comprises a standard gas cylinder (1) and a syringe pump (4), the outlet end of the standard gas cylinder (1) is connected to the inlet end of a gas washing bottle (6), when the smoke outlet of the smoke generation module is connected to the smoke inlet of the corrosion platform (8), the standard gas cylinder (1) contains non-condensable gas of the smoke, and when the smoke outlet of the smoke generation module is connected to the smoke inlet of the sulfuric acid content measuring device, the standard gas cylinder (1) contains nitrogen; the gas washing bottle (6) contains saturated concentrated sulfuric acid; the outlet end of the syringe pump (4) is connected to the inlet end of an evaporator (5), and the syringe pump (4) contains distilled water; the outlet end of the evaporator (5) is connected to the outlet end of the gas washing bottle (6) and the inlet end of the corrosion platform (8) or the sulfuric acid content measuring device; the outlet end of the corrosion platform (8) is connected to a tail gas treatment device (9); The sulfuric acid content measuring device comprises a PH measuring instrument (11) and a beaker (12), the beaker (12) contains distilled water (10), and the measuring end of the PH measuring instrument (11) is arranged in the distilled water (10); The outlet end of the evaporator (5) and the outlet end of the gas washing bottle (6) are connected to the corrosion platform (8) through a connecting pipeline, the connecting pipeline is a three-way pipeline, and a heating belt (13) is wound outside the connecting pipeline; the gas washing bottle (6) is arranged in a constant temperature box (7).

2. The dew point corrosion test system of claim 1, wherein, The outlet end of the standard gas cylinder (1) and the inlet end of the gas washing bottle (6) are sequentially connected to a pressure reducing valve (2) and a flow meter (3).

3. The dew point corrosion test system of claim 1, wherein, The corrosion platform (8) comprises a glass tube (804), an inner portion of the glass tube (804) is provided with a support (802), the smoke inlet of the corrosion platform (8) is arranged at the upper end of the glass tube (804), the smoke outlet of the corrosion platform (8) is arranged at the lower end of the glass tube (804), a metal sample (801) is placed on the support (802), a constant temperature heater (803) is arranged outside the glass tube (804), the top end of the support (802) is hollow, and the metal sample (801) is 3-5 cm away from the smoke inlet of the corrosion platform (8).

4. The dew point corrosion test system of claim 3, wherein, A plurality of metal samples (801) are arranged, and the plurality of metal samples (801) are evenly arranged.

5. The dew point corrosion test system of claim 1, wherein, The non-condensable gas of the smoke comprises oxygen, nitrogen, carbon dioxide and sulfur dioxide.

6. The dew point corrosion test system of claim 1, wherein, The connecting pipeline is made of a high-temperature and sulfuric acid corrosion resistant material, and the high-temperature and sulfuric acid corrosion resistant material comprises polytetrafluoroethylene.

7. A method for dew point corrosion test with adjustable components, using the dew point corrosion test system with adjustable components according to any one of claims 1-6, characterized in that, The method comprises the following steps: The smoke generation module is used to generate smoke, the sulfuric acid content in the smoke is measured by using the sulfuric acid content measuring device, the sulfuric acid content measuring device is replaced by the corrosion platform (8), the corrosion experiment is carried out by using the corrosion platform (8), and the tail gas in the experiment is treated by using the tail gas treatment device (9).

8. The method of claim 7, wherein the dew point is adjusted by adjusting the composition of the gas. The corrosion experiment using the corrosion platform (8) is specifically as follows: The heating belt (13) is turned on to heat the connecting pipeline, and the temperature of the heating belt (13) is controlled to be higher than the temperature of the constant temperature box (7). Setting the parameters of the flow meter (3), opening the standard gas cylinder (1) and adjusting the pressure reducing valve (2) to pass the non-condensable gas of the flue gas into the washing gas cylinder; Opening the thermostat (7) to heat and stir the saturated concentrated sulfuric acid in the washing gas cylinder (6) to generate sulfuric acid solution and flue gas, and passing the flue gas into the corrosion platform inlet (805); The gas outlet of the washing gas cylinder (6) is below the liquid level of the saturated concentrated sulfuric acid or the sulfuric acid solution; Setting the flow of the injection pump (4) and opening the injection pump (4) to inject distilled water into the evaporator to generate water vapor, and passing the water vapor into the corrosion platform inlet (805); Placing the metal sample (801) on the support (802) and opening the thermostat heater (803) to corrode the metal sample (801); Closing the thermostat (7) at the end of the experiment, and closing the heat tracing band and the standard gas cylinder (1) after the sulfuric acid solution in the washing gas cylinder (6) cools down.

9. The method of claim 7, wherein the dew point is adjusted by adjusting the composition of the gas mixture. Measuring the sulfuric acid content in the flue gas using a sulfuric acid content measuring device, specifically: Heating the connecting pipeline through the heat tracing band (13), and the temperature of the heat tracing band (13) is higher than the temperature of the thermostat (7); Setting the parameters of the flow meter (3), opening the standard gas cylinder (1) and adjusting the pressure reducing valve (2) to pass nitrogen into the washing gas cylinder (6); Opening the thermostat (7) to heat and stir the saturated concentrated sulfuric acid in the washing gas cylinder (6) to generate sulfuric acid solution and sulfuric acid vapor, and the outlet of the nitrogen in the washing gas cylinder (6) is below the liquid level of the saturated concentrated sulfuric acid or the sulfuric acid solution, and the outlet of the sulfuric acid vapor of the sulfuric acid content measuring device is below the liquid level of the distilled water (10); Measuring the PH value of the solution after the distilled water (10) absorbs the sulfuric acid vapor, repeating several times to take the average value, and recording the solution volume; Closing the thermostat (7) at the end of the experiment, and closing the heat tracing band and the standard gas cylinder (1) after the sulfuric acid solution in the washing gas cylinder (6) cools down. The sulfuric acid content in the flue gas is calculated by measuring the sulfuric acid content collected in the distilled water, and the calculation formula is as follows: Where, ppm(H2SO4) is the average content of H2SO4 in the flue gas during the period from t1 to t2; PH1 is the PH value of the solution in the beaker at t1; PH2 is the PH value of the solution in the beaker at t2; V1 is the solution volume in the beaker at t1; V2 is the solution volume in the beaker at t2; t is the time; qv is the gas volume flow.

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