Atmospheric tower top system dynamic corrosion experiment device and test method

Abstract

The invention provides an atmospheric tower top system dynamic corrosion experiment device and a test method. A dynamic corrosion experiment device for a normal-pressure tower top system comprises a water storage tank, an emulsification pump, a centrifugal pump, a flow meter, an electrochemical testing area and a corrosion testing area, the water storage tank is connected with the emulsification pump and the centrifugal pump through pipelines, the centrifugal pump is connected with the flow meter through a pipeline, and the flow meter is connected with the electrochemical testing area through a pipeline. The flow meter is connected with the electrochemical testing area through a pipeline, the electrochemical testing area is connected with the corrosion testing area through a pipeline, and a plurality of adjusting parts for adjusting the position of a sample are mounted in the corrosion testing area.

Description

Technical Field

[0001] This invention relates to the field of corrosion environment simulation technology, and in particular to a dynamic corrosion experimental apparatus and testing method for an atmospheric pressure tower top system. Background Technology

[0002] The oil refining industry is a pillar industry for economic development and social stability. In recent years, the increasing weight of crude oil has exacerbated equipment corrosion and failure problems, especially in the atmospheric distillation tower top volatiles pipeline system, where corrosion has become a significant safety hazard for long-term operation. The fundamental reason why corrosion in the atmospheric distillation tower top volatiles pipeline system is difficult to solve is that the high content of impurities such as sulfur, chlorine, and nitrogen in inferior crude oil means that the electrostatic desalting equipment cannot remove all inorganic salts and organic chlorines. Oil and gas condense along the pipeline, forming a multiphase corrosive environment of HCl-H2S-H2O at the dew point. Although injecting corrosion inhibitors, neutralizing agents, and water can have a corrosion-preventing effect, the variable composition of raw materials, fluctuations in process parameters, and changes in material properties during crude oil refining make it difficult to predict the ion balance of the "gas-hydrocarbon-water" multiphase environment in the tower top oil and gas system. This results in the dynamic relationship between pH and corrosion inhibitors not being adjusted accurately and in a timely manner according to process parameters, or the "three-injection process" corrosion prevention measures not being adjusted in time with the actual production raw material conditions. Consequently, the process corrosion prevention effect is unsatisfactory, and corrosion problems cannot be completely avoided.

[0003] To simulate corrosion problems in atmospheric pressure tower top evaporation line systems, conventional high-temperature and high-pressure autoclaves are typically used in laboratory coring corrosion experiments. This type of corrosion experiment has certain limitations: 1) The liquid flow rate is calculated by adjusting the rotation speed, which differs from the actual flow state of the medium inside the pipeline, and it cannot provide in-depth research on the influence of medium flow rate and state on corrosion; 2) The samples are limited to coring plates and cannot be applied to pipe fittings, etc., and the sample position is fixed and cannot be adjusted; 3) When used to evaluate the effectiveness of corrosion inhibitors, the amount of corrosion inhibitor added must be determined for each test and cannot be adjusted or changed during the experiment. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a dynamic corrosion test device and test method for an atmospheric pressure tower top system, which addresses the shortcomings of the prior art.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A dynamic corrosion test device for an atmospheric pressure tower top system includes: a water storage tank, an emulsifying pump, a centrifugal pump, a flow meter, an electrochemical test area, and a corrosion test area. The water storage tank is connected to the emulsifying pump and the centrifugal pump through pipelines. The centrifugal pump is connected to the flow meter through a pipeline. The flow meter is connected to the electrochemical test area through a pipeline. The electrochemical test area is connected to the corrosion test area through a pipeline. The corrosion test area is equipped with multiple adjustment components for adjusting the position of the sample.

[0006] The beneficial effects of adopting the technical solution of this invention are: it more closely resembles the actual corrosion conditions in the field, which is beneficial for testing different samples under different conditions, and the test stability is good. It simulates the real flow state of the medium in the pipeline, allowing for in-depth research on the influence of medium flow rate and state on corrosion. The sample is not limited to hanging plates but can also be used for pipe fittings, etc., and the sample position is adjustable vertically, allowing for research on the influence of sample shape and position on fluid state and corrosion. When used for evaluating the effectiveness of corrosion inhibitors, the amount and method of adding the corrosion inhibitor can be changed as needed during the test, making the test results closer to the actual service environment. A water storage tank is used to store the experimental medium. An emulsifying pump is connected to the water storage tank; its function is to fully emulsify the experimental medium, avoiding stratification and unevenness. A centrifugal pump is connected to the water storage tank; its function is to draw the experimental medium into the pipeline and control the flow rate. A flow meter is used to measure the magnitude of the experimental medium flow rate.

[0007] Furthermore, multiple ball valves are installed on the pipeline between the centrifugal pump and the flow meter; a manual regulating valve is installed on the pipeline between the flow meter and the electrochemical testing area.

[0008] The beneficial effects of adopting the above-mentioned further technical solution are: multiple ball valves are installed after the centrifugal pump for the adjustment and control of the experimental medium. A manual regulating valve is installed before the electrochemical testing area for the adjustment and control of the experimental medium during electrochemical testing.

[0009] Furthermore, the corrosion test area is connected to an air cooler via a pipeline, and the air cooler is connected to the water storage tank via a pipeline.

[0010] The beneficial effect of adopting the above-mentioned further technical solution is that the air cooler is used to cool the experimental medium after the test, and then the medium flows back into the water storage tank.

[0011] Furthermore, the corrosion test area is connected to the water storage tank via a pipeline, and the air cooler is connected in parallel with the pipeline between the corrosion test area and the water storage tank via a pipeline; a check valve is installed on the pipeline between the corrosion test area and the air cooler, and a ball valve is installed on the inlet pipeline of the air cooler.

[0012] The beneficial effects of adopting the above-mentioned further technical solution are: a check valve is installed in front of the air cooler to prevent the medium from flowing back; a ball valve is installed on the inlet pipe of the air cooler. During normal experiment, the ball valve is in the closed state. After the experiment, the ball valve is opened to cool the experimental medium and then flows back to the water storage tank.

[0013] Furthermore, the water storage tank is equipped with an inlet at the top and an outlet at the bottom, and a heating device is installed on the water storage tank; the heating device and the flow meter are both connected to a control cabinet.

[0014] The beneficial effects of adopting the above-mentioned further technical solution are as follows: the water storage tank is used to store experimental media, with an inlet at the top for adding experimental media and a drain at the bottom. The control cabinet is used for real-time automatic acquisition of experimental parameters such as temperature and flow rate.

[0015] Furthermore, the electrochemical testing area includes a testing chamber and an electrochemical testing system. Flanges are installed on both sides of the testing chamber. The electrochemical testing system includes a working electrode, an auxiliary electrode, and a reference electrode. The working electrode, the auxiliary electrode, and the reference electrode are all installed on the testing chamber by nuts. The working electrode, the auxiliary electrode, and the reference electrode are all connected to an electrochemical workstation.

[0016] The beneficial effects of adopting the above-mentioned further technical solution are as follows: the test chamber is connected to the pipeline on both sides by flanges, which are tightened with bolts, and the flanges are sealed with sealing gaskets. The three electrode rods are all fixed to the test chamber with nuts, the electrodes are placed in the experimental medium inside the test chamber, and the three electrode wires are connected to the electrochemical workstation.

[0017] Furthermore, the adjusting component is a fastening bolt, the adjusting component is installed at the bottom of the corrosion test area, and a fixing cover plate is installed on the top of the corrosion test area.

[0018] The advantages of adopting the above-mentioned further technical solution are: the corrosion test area is connected to the pipeline at both ends, and the upper part is sealed with a fixed cover plate, which facilitates sample removal. The sample is fixed to the bottom of the corrosion test area with fastening bolts, and the sample height is adjustable.

[0019] Furthermore, this invention also provides a dynamic corrosion testing method for an atmospheric pressure tower top system. Based on the dynamic corrosion testing apparatus for an atmospheric pressure tower top system described in any one of the above-mentioned methods, the dynamic corrosion testing method for an atmospheric pressure tower top system includes: S1, obtaining the sample mass, total sample area, and sample material density before the test; S2, conducting the test on the sample using the dynamic corrosion testing apparatus for an atmospheric pressure tower top system and recording the test time; S3, removing the sample after the test and weighing the sample to obtain the sample mass after the test; S4, measuring the deepest pitting depth on the sample surface after the test; S5, calculating the corrosion rate based on the deepest pitting depth on the sample surface after the test, the test time, the sample mass before the test, the sample mass after the test, the total sample area, and the sample material density.

[0020] The beneficial effects of adopting the technical solution of this invention are: simplified testing methods and improved testing accuracy; closer to actual corrosion conditions, facilitating testing of different samples under different conditions, and exhibiting good testing stability; simulating the real flow state of the medium within the pipeline, allowing for in-depth research into the influence of medium flow rate and state on corrosion; samples are not limited to hanging plates but can also be used for pipe fittings, etc., and the sample position is adjustable vertically, allowing for research into the influence of sample shape and position on fluid state and corrosion; when used for evaluating the effectiveness of corrosion inhibitors, the amount and method of adding the corrosion inhibitor can be changed as needed during the test, making the test results closer to the actual service environment; a water storage tank is used to store the experimental medium; an emulsifying pump is connected to the water storage tank, its function being to fully emulsify the experimental medium, avoiding stratification and unevenness; a centrifugal pump is connected to the water storage tank, its function being to draw the experimental medium into the pipeline and control the flow rate; a flow meter is used to measure the magnitude of the experimental medium flow rate.

[0021] Further, step S3 includes: S31, after the test, take out the sample, rinse it with clean water and wipe it dry with filter paper; S32, put the sample into acetone and remove the oil stains on the sample surface with degreased cotton; S33, remove the corrosion products with a film removal solution and rinse with deionized water; S34, soak it in anhydrous ethanol for a first preset time; S35, take out the sample, dry it with cold air and place it in a desiccator for a second preset time; S36, weigh the sample after the test to obtain the mass of the sample after the test; in step S4, the deepest pitting depth on the surface of the sample after the test is measured by a pitting depth sounder.

[0022] The beneficial effects of adopting the above-mentioned further technical solutions are: pre-treating the sample to prevent impurities from affecting the test results and improving the test accuracy.

[0023] Furthermore, the corrosion rate includes pitting corrosion rate and uniform corrosion rate; the pitting corrosion rate is calculated using the following formula:

[0024]

[0025] Where, r t The pitting rate is expressed in mm / year; h t The deepest pitting depth on the sample surface after the test is in mm; t is the test time in hours.

[0026] The uniform corrosion rate is calculated using the following formula.

[0027]

[0028] Where, r corr The uniform corrosion rate is expressed in mm / year; m is the sample mass before the test, expressed in g; m t S1 represents the mass of the sample after the test, in grams; S2 represents the total area of ​​the sample, in centimeters.2 ρ is the density of the sample material, in g / cm³. 3 t represents the test time, in hours (h).

[0029] The beneficial effects of adopting the above-mentioned further technical solutions are: by calculating the pitting rate and uniform corrosion rate through formulas, the calculation method is simplified and the accuracy of the test results is improved.

[0030] The advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the dynamic corrosion test apparatus for the atmospheric pressure tower top system provided in an embodiment of the present invention.

[0032] Figure 2 This is one of the structural schematic diagrams of the corrosion test area provided in an embodiment of the present invention.

[0033] Figure 3 This is the second schematic diagram of the corrosion test area provided in an embodiment of the present invention.

[0034] Figure 4 This is a schematic flowchart illustrating the dynamic corrosion testing method for an atmospheric pressure tower top system provided in an embodiment of the present invention.

[0035] The following are the reference numerals: 1. Water storage tank; 2. Emulsifying pump; 3. Centrifugal pump; 4. Ball valve; 5. Flow meter; 6. Manual regulating valve; 7. Electrochemical testing area; 8. Corrosion testing area; 9. Check valve; 10. Air cooler; 11. Sample; 12. Fastening bolt. Detailed Implementation

[0036] The principles and features of the present invention are described below with reference to the accompanying drawings. The embodiments described are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0037] like Figures 1 to 3 As shown, this embodiment of the invention provides a dynamic corrosion test device for an atmospheric pressure tower top system, including: a water storage tank 1, an emulsifying pump 2, a centrifugal pump 3, a flow meter 5, an electrochemical test area 7, and a corrosion test area 8. The water storage tank 1 is connected to the emulsifying pump 2 and the centrifugal pump 3 through pipelines. The centrifugal pump 3 is connected to the flow meter 5 through a pipeline. The flow meter 5 is connected to the electrochemical test area 7 through a pipeline. The electrochemical test area 7 is connected to the corrosion test area 8 through a pipeline. The corrosion test area 8 is equipped with multiple adjustment components for adjusting the position of the sample 11.

[0038] The beneficial effects of adopting the technical solution of this invention are: it more closely resembles the actual corrosion conditions in the field, which is beneficial for testing different samples under different conditions, and the test stability is good. It simulates the real flow state of the medium in the pipeline, allowing for in-depth research on the influence of medium flow rate and state on corrosion. The sample is not limited to hanging plates but can also be used for pipe fittings, etc., and the sample position is adjustable vertically, allowing for research on the influence of sample shape and position on fluid state and corrosion. When used for evaluating the effectiveness of corrosion inhibitors, the amount and method of adding the corrosion inhibitor can be changed as needed during the test, making the test results closer to the actual service environment. A water storage tank is used to store the experimental medium. An emulsifying pump is connected to the water storage tank; its function is to fully emulsify the experimental medium, avoiding stratification and unevenness. A centrifugal pump is connected to the water storage tank; its function is to draw the experimental medium into the pipeline and control the flow rate. A flow meter is used to measure the magnitude of the experimental medium flow rate.

[0039] The arrows in the diagram represent the flow direction and trajectory of the medium.

[0040] like Figures 1 to 3 As shown, further, multiple ball valves 4 are installed on the pipeline between the centrifugal pump 3 and the flow meter 5; and a manual regulating valve 6 is installed on the pipeline between the flow meter 5 and the electrochemical test area 7.

[0041] The beneficial effects of adopting the above-mentioned further technical solution are: multiple ball valves are installed after the centrifugal pump for the adjustment and control of the experimental medium. A manual regulating valve is installed before the electrochemical testing area for the adjustment and control of the experimental medium during electrochemical testing.

[0042] like Figures 1 to 3 As shown, the corrosion test area 8 is further connected to an air cooler 10 via a pipeline, and the air cooler 10 is connected to the water storage tank 1 via a pipeline.

[0043] The beneficial effect of adopting the above-mentioned further technical solution is that the air cooler is used to cool the experimental medium after the test, and then the medium flows back into the water storage tank.

[0044] like Figures 1 to 3 As shown, further, the corrosion test area 8 is connected to the water storage tank 1 through a pipeline, and the air cooler 10 is connected in parallel with the pipeline between the corrosion test area 8 and the water storage tank 1 through a pipeline; a check valve 9 is installed on the pipeline between the corrosion test area 8 and the air cooler 10, and a ball valve is installed on the inlet pipeline of the air cooler 10.

[0045] The beneficial effects of adopting the above-mentioned further technical solution are: a check valve is installed in front of the air cooler to prevent the medium from flowing back; a ball valve is installed on the inlet pipe of the air cooler. During normal experiment, the ball valve is in the closed state. After the experiment, the ball valve is opened to cool the experimental medium and then flows back to the water storage tank.

[0046] like Figures 1 to 3 As shown, the top of the water storage tank 1 is equipped with a liquid inlet, the bottom of the water storage tank is equipped with a liquid outlet, and a heating device is installed on the water storage tank 1; the heating device and the flow meter 5 are both connected to a control cabinet.

[0047] The beneficial effects of adopting the above-mentioned further technical solution are as follows: the water storage tank is used to store experimental media, with an inlet at the top for adding experimental media and a drain at the bottom. The control cabinet is used for real-time automatic acquisition of experimental parameters such as temperature and flow rate.

[0048] like Figures 1 to 3 As shown, the electrochemical testing area 7 further includes a testing chamber and an electrochemical testing system. Flanges are installed on both sides of the testing chamber. The electrochemical testing system includes a working electrode, an auxiliary electrode, and a reference electrode. The working electrode, the auxiliary electrode, and the reference electrode are all installed on the testing chamber by nuts. The working electrode, the auxiliary electrode, and the reference electrode are all connected to an electrochemical workstation.

[0049] The beneficial effects of adopting the above-mentioned further technical solution are as follows: the test chamber is connected to the pipeline on both sides by flanges, which are tightened with bolts, and the flanges are sealed with sealing gaskets. The three electrode rods are all fixed to the test chamber with nuts, the electrodes are placed in the experimental medium inside the test chamber, and the three electrode wires are connected to the electrochemical workstation.

[0050] like Figures 1 to 3 As shown, the adjusting component is a fastening bolt 12, which is installed at the bottom of the corrosion test area 8, and a fixing cover is installed on the top of the corrosion test area 8.

[0051] The advantages of adopting the above-mentioned further technical solution are: the corrosion test area is connected to the pipeline at both ends, and the upper part is sealed with a fixed cover plate, which facilitates sample removal. The sample is fixed to the bottom of the corrosion test area with fastening bolts, and the sample height is adjustable.

[0052] The experimental setup (dynamic corrosion test setup for atmospheric pressure tower top system) includes a control cabinet, a water storage tank 1, an emulsifying pump 2, a centrifugal pump 3, a flow meter 5, an electrochemical test area 7, a corrosion test area 8, and an air cooler 10; the test methods include electrochemical testing and corrosion rate testing.

[0053] The control cabinet is used for the real-time automatic acquisition of experimental parameters such as temperature and flow rate.

[0054] The water storage tank 1 is used to store experimental media. It has an inlet at the top for adding experimental media and a drain at the bottom. The water storage tank 1 is connected to the emulsification pump 2 and the centrifugal pump 3, and is equipped with a heating device (the heating device can be any heating method such as a heating rod or heating coil). It is connected to the control cabinet, and the experimental temperature adjustment range is 20℃-120℃.

[0055] Emulsifying pump 2 is connected to water storage tank 1. Its function is to fully emulsify the experimental medium (especially by adding oil-soluble corrosion inhibitors to water-soluble media or water-soluble corrosion inhibitors to oil-soluble media) to avoid stratification.

[0056] Centrifugal pump 3 is connected to water storage tank 1. Its function is to draw the experimental medium into the pipeline and control the flow rate. Two ball valves 4 are installed after centrifugal pump 3 for the adjustment and control of the experimental medium.

[0057] The flow meter 5 is located after the ball valve 4 and is used to measure the flow velocity of the experimental medium. The flow velocity adjustment range is 0 m / s-10 m / s.

[0058] Electrochemical testing area 7 includes a testing chamber and an electrochemical testing system. The testing chamber is connected to the pipeline on both sides by flanges, secured with bolts, and sealed with gaskets. The electrochemical testing system includes a working electrode, an auxiliary electrode, and a reference electrode. All three electrode rods are fixed to the testing chamber with nuts. The electrodes are placed in the experimental medium within the chamber (test chamber), and the electrode leads are connected to the electrochemical workstation. A manual regulating valve 6 is installed before electrochemical testing area 7 for adjusting and controlling the experimental medium during electrochemical testing.

[0059] The corrosion test area 8 is connected to the pipeline at both ends. The size of the corrosion test area 8 is designed as needed, and the upper part is sealed with a fixed cover plate for easy access to the sample 11. The corrosion test area 8 has three sample placement positions. The sample (sample 11) is fixed to the bottom of the corrosion test area 8 with fastening bolts 12, and the sample height is adjustable. Corrosion tests are conducted according to the experimental conditions. After the test, the uniform corrosion rate and pitting rate of the material (sample material) are calculated using the weight loss method.

[0060] The air cooler 10 is used to cool the experimental medium after the test, and then the medium flows back to the water storage tank 1. A check valve 9 is installed before the air cooler 10 to prevent the medium from flowing back. A ball valve is installed on the inlet pipe of the air cooler 10. During normal testing, the ball valve is in the closed state. After the test, the ball valve is opened to cool the experimental medium, and then the medium flows back to the water storage tank 1.

[0061] like Figure 4As shown, this invention also provides a dynamic corrosion testing method for an atmospheric pressure tower top system. Based on the dynamic corrosion testing apparatus for an atmospheric pressure tower top system described in any one of the above-mentioned methods, the dynamic corrosion testing method for an atmospheric pressure tower top system includes: S1, obtaining the sample mass, total area of ​​the sample, and density of the sample material before the test; S2, conducting the test on the sample using the dynamic corrosion testing apparatus for an atmospheric pressure tower top system and recording the test time; S3, removing the sample after the test and weighing the sample after the test to obtain the sample mass after the test; S4, measuring the deepest pitting depth on the sample surface after the test; S5, calculating the corrosion rate based on the deepest pitting depth on the sample surface after the test, the test time, the sample mass before the test, the sample mass after the test, the total area of ​​the sample, and the density of the sample material.

[0062] The beneficial effects of adopting the technical solution of this invention are: simplified testing methods and improved testing accuracy; closer to actual corrosion conditions, facilitating testing of different samples under different conditions, and exhibiting good testing stability; simulating the real flow state of the medium within the pipeline, allowing for in-depth research into the influence of medium flow rate and state on corrosion; samples are not limited to hanging plates but can also be used for pipe fittings, etc., and the sample position is adjustable vertically, allowing for research into the influence of sample shape and position on fluid state and corrosion; when used for evaluating the effectiveness of corrosion inhibitors, the amount and method of adding the corrosion inhibitor can be changed as needed during the test, making the test results closer to the actual service environment; a water storage tank is used to store the experimental medium; an emulsifying pump is connected to the water storage tank, its function being to fully emulsify the experimental medium, avoiding stratification and unevenness; a centrifugal pump is connected to the water storage tank, its function being to draw the experimental medium into the pipeline and control the flow rate; a flow meter is used to measure the magnitude of the experimental medium flow rate.

[0063] Further, step S3 includes: S31, after the test, take out the sample, rinse it with clean water and wipe it dry with filter paper; S32, put the sample into acetone and remove the oil stains on the sample surface with degreased cotton; S33, remove the corrosion products with a film removal solution and rinse with deionized water; S34, soak it in anhydrous ethanol for a first preset time; S35, take out the sample, dry it with cold air and place it in a desiccator for a second preset time; S36, weigh the sample after the test to obtain the mass of the sample after the test; in step S4, the deepest pitting depth on the surface of the sample after the test is measured by a pitting depth sounder.

[0064] The beneficial effects of adopting the above-mentioned further technical solutions are: pre-treating the sample to prevent impurities from affecting the test results and improving the test accuracy.

[0065] Furthermore, the corrosion rate includes pitting corrosion rate and uniform corrosion rate; the pitting corrosion rate is calculated using the following formula:

[0066]

[0067] Where, r t The pitting rate is expressed in mm / year; h t The deepest pitting depth on the sample surface after the test is in mm; t is the test time in hours.

[0068] The uniform corrosion rate is calculated using the following formula.

[0069]

[0070] Where, r corr The uniform corrosion rate is expressed in mm / year; m is the sample mass before the test, expressed in g; m t S1 represents the mass of the sample after the test, in grams; S2 represents the total area of ​​the sample, in centimeters. 2 ρ is the density of the sample material, in g / cm³. 3 t represents the test time, in hours (h).

[0071] The beneficial effects of adopting the above-mentioned further technical solutions are: by calculating the pitting rate and uniform corrosion rate through formulas, the calculation method is simplified and the accuracy of the test results is improved.

[0072] The electrochemical and corrosion rate testing conditions were set according to actual experimental conditions. The electrochemical testing method was the same as the conventional method; the corrosion rate test included the determination of pitting corrosion rate and uniform corrosion rate.

[0073] Specifically, after the test, the sample is taken out, rinsed with clean water and dried with filter paper. Then, the sample is placed in acetone and the oil stains on the sample surface are removed with degreased cotton. Then, the corrosion products are removed with a film removal solution (different film removal solutions are prepared for different materials), rinsed with deionized water, soaked in anhydrous ethanol for 5 minutes (first preset time), the sample is taken out, dried with cold air and placed in a desiccator for 1 hour (second preset time) before being weighed.

[0074] Specifically, the observation of pitting corrosion on the sample surface involves using a 10x microscope to observe whether pitting corrosion exists on the sample surface. If pitting corrosion exists, the microscope magnification is increased to 100x, the number of pits per unit area on the sample surface is recorded, and the deepest pitting depth is measured using a pitting depth sounder.

[0075] Pitting rate r t The determination is calculated according to formula (1):

[0076]

[0077] In the formula, r t Pitting rate, mm / year; h t The deepest pitting depth on the sample surface after the test is denoted as mm; t is the test time, in hours.

[0078] Specifically, the uniform corrosion rate is determined according to formula (2):

[0079]

[0080] In the formula, r corr The corrosion rate is uniform, in mm / year; m is the sample mass before the test, in g; m t S1 is the mass of the sample after the test, in grams; S2 is the total area of ​​the sample, in centimeters. 2 ρ is the density of the sample material, in g / cm³. 3 t represents the test time, in hours.

[0081] Compared with the prior art, the present invention has the following beneficial technical effects:

[0082] 1) It can simulate the real flow state of the medium in the pipeline and conduct in-depth research on the influence of medium flow rate and state on corrosion.

[0083] 2) The sample is not limited to the hanging plate, but can also be used for pipe fittings, etc., and the position of the sample can be adjusted up and down, so as to study the influence of the sample shape and position on the fluid state and corrosion.

[0084] 3) When used for evaluating the effectiveness of corrosion inhibitors, the amount and method of adding the corrosion inhibitor can be changed as needed during the test to make the test results closer to the actual service environment.

[0085] 4) The emulsifying pump in this invention can fully emulsify the experimental medium, avoiding stratification and unevenness of the medium.

[0086] 5) Electrochemical tests and corrosion tests can be conducted simultaneously or separately.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dynamic corrosion test apparatus for an atmospheric pressure tower top system, characterized in that, include: The system includes a water storage tank, an emulsifying pump, a centrifugal pump, a flow meter, an electrochemical testing area, and a corrosion testing area. The water storage tank is connected to the emulsifying pump and the centrifugal pump via pipelines. The centrifugal pump is connected to the flow meter via a pipeline. The flow meter is connected to the electrochemical testing area via a pipeline. The electrochemical testing area is connected to the corrosion testing area via a pipeline. The corrosion testing area is equipped with multiple adjustment components for adjusting the position of the sample.

2. The dynamic corrosion test apparatus for an atmospheric pressure tower top system according to claim 1, characterized in that, Multiple ball valves are installed on the pipeline between the centrifugal pump and the flow meter; a manual regulating valve is installed on the pipeline between the flow meter and the electrochemical testing area.

3. The dynamic corrosion test apparatus for an atmospheric pressure tower top system according to claim 1, characterized in that, The corrosion testing area is connected to an air cooler via pipelines, and the air cooler is connected to the water storage tank via pipelines.

4. The dynamic corrosion test apparatus for an atmospheric pressure tower top system according to claim 3, characterized in that, The corrosion testing area is connected to the water storage tank via a pipeline, and the air cooler is connected in parallel with the pipeline between the corrosion testing area and the water storage tank via a pipeline; a check valve is installed on the pipeline between the corrosion testing area and the air cooler, and a ball valve is installed on the inlet pipeline of the air cooler.

5. The dynamic corrosion test apparatus for an atmospheric pressure tower top system according to claim 1, characterized in that, The water storage tank is equipped with an inlet at the top and a drain at the bottom, and a heating device is installed on the tank; the heating device and the flow meter are both connected to a control cabinet.

6. The dynamic corrosion test apparatus for an atmospheric pressure tower top system according to claim 1, characterized in that, The electrochemical testing area includes a testing chamber and an electrochemical testing system. Flanges are installed on both sides of the testing chamber. The electrochemical testing system includes a working electrode, an auxiliary electrode, and a reference electrode. The working electrode, the auxiliary electrode, and the reference electrode are all installed on the testing chamber by nuts. The working electrode, the auxiliary electrode, and the reference electrode are all connected to an electrochemical workstation.

7. The dynamic corrosion test apparatus for an atmospheric pressure tower top system according to claim 1, characterized in that, The adjusting component is a fastening bolt, which is installed at the bottom of the corrosion test area, and a fixed cover plate is installed at the top of the corrosion test area.

8. A dynamic corrosion testing method for an atmospheric pressure tower top system, characterized in that, Based on the dynamic corrosion test apparatus for an atmospheric pressure tower top system according to any one of claims 1 to 7, the dynamic corrosion test method for the atmospheric pressure tower top system includes: S1. Obtain the sample mass, total area of ​​the sample, and density of the sample material before the test; S2. Test the samples using the dynamic corrosion test device at the top of the atmospheric pressure tower and record the test time; S3. After the test, take out the sample and weigh it to obtain the mass of the sample after the test. S4. Measure the deepest pitting depth on the sample surface after the test; S5. Calculate the corrosion rate based on the deepest pitting depth on the sample surface after the test, the test time, the sample mass before the test, the sample mass after the test, the total area of ​​the sample, and the density of the sample material.

9. The dynamic corrosion testing method for an atmospheric pressure tower top system according to claim 8, characterized in that, Step S3 includes: S31. After the test, remove the sample, rinse it with clean water and wipe it dry with filter paper; S32. Place the sample in acetone and remove oil stains from the sample surface with degreased cotton. S33. Use a film removal solution to remove corrosion products, and rinse with deionized water; S34. Soak in anhydrous ethanol for the first preset time; S35. After removing the sample and drying it with cold air, place it in a desiccator and leave it for the second preset time. S36. Weigh the test specimen after the test to obtain the mass of the test specimen; In step S4, the deepest pitting depth on the sample surface after the test is measured using a pitting depth sounder.

10. A dynamic corrosion testing method for an atmospheric pressure tower top system according to claim 8. Its features are, The corrosion rate includes pitting corrosion rate and uniform corrosion rate. The pitting rate is calculated using the following formula. Where, r t The pitting rate is expressed in mm / year; h t The deepest pitting depth on the sample surface after the test is in mm; t is the test time in hours. The uniform corrosion rate is calculated using the following formula. Where, r corr The uniform corrosion rate is expressed in mm / year; m is the sample mass before the test, expressed in g; m t S1 represents the mass of the sample after the test, in grams; S2 represents the total area of ​​the sample, in centimeters. 2 ρ is the density of the sample material, in g / cm³. 3 t represents the test time, in hours (h).

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