CN-121994895-A - Dynamic corrosion experimental device and method for normal pressure tower top system

CN121994895ACN 121994895 ACN121994895 ACN 121994895ACN-121994895-A

Abstract

The invention provides a dynamic corrosion experimental device and a testing method for an atmospheric tower top system. A dynamic corrosion experimental device of a normal pressure tower top system comprises a water storage tank, an emulsion pump, a centrifugal pump, a flowmeter, an electrochemical test area and a corrosion test area, wherein the water storage tank is respectively connected with the emulsion pump and the centrifugal pump through pipelines, the centrifugal pump is connected with the flowmeter through a pipeline, the flowmeter is connected with the electrochemical test area through a pipeline, the electrochemical test area is connected with the corrosion test area through a pipeline, and a plurality of adjusting parts for adjusting the position of a sample are arranged in the corrosion test area.

Inventors

XU XIUQING
WANG SUI
LI FAGEN
HUANG JUFENG
SU HANG

Assignees

中国石油天然气集团有限公司
中国石油集团工程材料研究院有限公司

Dates

Publication Date: 20260508
Application Date: 20241101

Claims (10)

1. The dynamic corrosion experimental device for the normal pressure tower top system is characterized by comprising a water storage tank, an emulsion pump, a centrifugal pump, a flowmeter, an electrochemical test area and a corrosion test area, wherein the water storage tank is respectively connected with the emulsion pump and the centrifugal pump through pipelines, the centrifugal pump is connected with the flowmeter through pipelines, the flowmeter is connected with the electrochemical test area through pipelines, the electrochemical test area is connected with the corrosion test area through pipelines, and a plurality of adjusting parts for adjusting the position of a sample are arranged in the corrosion test area.
2. The dynamic corrosion experimental device for the atmospheric tower top system, according to claim 1, is characterized in that a plurality of ball valves are arranged on a pipeline between the centrifugal pump and the flowmeter, and a manual regulating valve is arranged on a pipeline between the flowmeter and the electrochemical testing area.
3. The dynamic corrosion test device for the atmospheric tower top system according to claim 1, wherein the corrosion test area is connected with an air cooler through a pipeline, and the air cooler is connected with the water storage tank through a pipeline.
4. The dynamic corrosion experimental device for the atmospheric tower top system according to claim 3, wherein the corrosion testing area is connected with the water storage tank through a pipeline, the air cooler is connected with the pipeline between the corrosion testing area and the water storage tank in parallel through a pipeline, a check valve is arranged on the pipeline between the corrosion testing area and the air cooler, and a ball valve is arranged on an inlet pipeline of the air cooler.
5. The dynamic corrosion experimental device for the atmospheric tower top system, which is disclosed in claim 1, is characterized in that a liquid inlet is arranged at the top of the water storage tank, a liquid outlet is arranged at the bottom of the water storage tank, a heating device is arranged on the water storage tank, and the heating device and the flowmeter are both connected with a control cabinet.
6. The dynamic corrosion experimental device for the atmospheric tower top system according to claim 1, wherein the electrochemical testing area comprises a testing cavity and an electrochemical testing system, flanges are arranged on two sides of the testing cavity, the electrochemical testing system comprises a working electrode, an auxiliary electrode and a reference electrode, the working electrode, the auxiliary electrode and the reference electrode are arranged on the testing cavity through nuts, and electrochemical workstations are connected to the working electrode, the auxiliary electrode and the reference electrode.
7. The dynamic corrosion test device for an atmospheric tower top system according to claim 1, wherein the adjusting component is a fastening bolt, the adjusting component 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 method for testing dynamic corrosion of an atmospheric tower system, characterized in that the method for testing dynamic corrosion of an atmospheric tower system comprises the following steps based on the experimental device for dynamic corrosion of an atmospheric tower system according to any one of claims 1 to 7: s1, acquiring the mass of a sample before a test, the total area of the sample and the density of a sample material; s2, testing a sample through a dynamic corrosion experimental device of the normal pressure tower top system, and recording test time; S3, taking out the sample after the test, and weighing the sample after the test to obtain the mass of the sample after the test; S4, measuring the deepest pitting depth of the surface of the sample after the test; s5, calculating the corrosion rate according to the deepest pitting depth of the surface of the sample after the test, the test time, the mass of the sample before the test, the mass of the sample after the test, the total area of the sample and the density of the sample material.
9. The method for dynamic corrosion testing of an atmospheric tower top system according to claim 8, wherein step S3 comprises: S31, taking out a sample after the test, flushing with clear water and wiping with filter paper; s32, placing the sample into acetone, and removing greasy dirt on the surface of the sample by using absorbent cotton; s33, removing corrosion products by adopting a membrane removing liquid, and flushing with deionized water; s34, soaking in absolute ethyl alcohol for a first preset time; S35, taking out a sample, drying by cold air, and then placing the sample in a dryer for a second preset time; s36, weighing the tested sample to obtain the mass of the tested sample; in step S4, the deepest pitting depth of the surface of the sample after the test is measured by a pitting sounding instrument.
10. The method for dynamic corrosion testing of an atmospheric tower overhead system according to claim 8, Wherein the corrosion rate comprises a pitting corrosion rate and a uniform corrosion rate; The pitting rate is calculated by the following formula, Wherein r t is the pitting rate in mm/year, h t is the deepest pitting depth of the surface of the tested sample in mm, and t is the test time in h; The uniform corrosion rate was calculated by the following formula, Wherein r corr is uniform corrosion rate in mm/year, m is sample mass before test in g, m t is sample mass after test in g, S 1 is total area of sample in cm 2 , ρ is density of sample material in g/cm 3 , and t is test time in h.

Description

Dynamic corrosion experimental device and method for normal pressure tower top system Technical Field The invention relates to the technical field of corrosion environment simulation, in particular to a dynamic corrosion experimental device and a testing method for an atmospheric tower top system. Background The oil refining industry is a pillar industry with economic development and stable society, the problem of equipment corrosion failure caused by crude oil heavy weight in recent years is aggravated, especially the corrosion condition of a volatile pipeline system at the top of a normal pressure tower is prominent, and the corrosion of a device becomes a potential safety hazard for long-period operation. The root cause of the corrosion of the volatile pipeline system at the top of the normal pressure tower is that the inferior crude oil has high content of sulfur, chlorine, nitrogen and other impurities, the electric desalting equipment can not remove all inorganic salt and organic chlorine, the oil gas is condensed along the pipeline, and the HCl-H 2S-H2 O multiphase corrosion environment is formed at the dew point. Although corrosion inhibitors, neutralizers and water can be injected to achieve the anti-corrosion effect, the dynamic relationship between pH and corrosion inhibitors cannot be timely and accurately adjusted according to the process parameters because of variable raw material property components, fluctuation of process parameters and material physical property parameter changes in crude oil mixing production, and the multi-phase environment ion balance of a gas-hydrocarbon-water multiphase oil-gas system at the top of the tower cannot be predicted easily, or the anti-corrosion measures of a three-injection process cannot be timely adjusted along with the actual production raw materials, so that the process anti-corrosion effect is not ideal, and the corrosion problem cannot be thoroughly avoided. In order to simulate the corrosion problem of an atmospheric tower top swing line system, a conventional high-temperature high-pressure kettle is generally adopted to carry out a hanging piece corrosion experiment in a laboratory. The corrosion experiment has certain limitations that 1) the flow rate of liquid is calculated by adjusting the rotating speed, the flow rate is different from the real flowing state of a medium in a pipeline, and the rule of the influence of the flow rate and the state of the medium on corrosion cannot be deeply studied, 2) a sample is limited to hanging pieces and cannot be applied to pipe fittings and the like, the position of the sample is fixed and cannot be adjusted, and 3) when the corrosion inhibitor is used for evaluating the effect of the corrosion inhibitor, the adding amount of the corrosion inhibitor needs to be determined in each experiment, and the corrosion inhibitor cannot be adjusted or changed in the experiment. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a dynamic corrosion experimental device and a testing method for an atmospheric tower top system. The technical scheme includes that the dynamic corrosion experimental device for the normal pressure tower top system comprises a water storage tank, an emulsion pump, a centrifugal pump, a flowmeter, an electrochemical test area and a corrosion test area, wherein the water storage tank is respectively connected with the emulsion pump and the centrifugal pump through pipelines, the centrifugal pump is connected with the flowmeter through pipelines, the flowmeter is connected with the electrochemical test area through pipelines, the electrochemical test area is connected with the corrosion test area through pipelines, and a plurality of adjusting components for adjusting the position of a sample are arranged in the corrosion test area. The technical scheme of the invention has the advantages that the method is closer to the on-site corrosion working condition, is beneficial to testing different samples under different conditions, and has good test stability. The real flowing state of the medium in the pipeline is simulated, and the rule of the influence of the flow speed and the state of the medium on corrosion is studied deeply. The sample is not limited to the hanging piece, and can be used for pipe fittings and the like, and the position of the sample can be adjusted up and down, so that the influence of the shape, the position and the like of the sample on the fluid state and corrosion can be studied. When the method is used for evaluating the effect of the corrosion inhibitor, the addition amount and the addition mode of the corrosion inhibitor can be changed according to the requirement in the test process, so that the test result is closer to the actual service environment. The water storage tank is used for storing experimental media. The emulsifying pump is connected with the water storage tank, and the emulsifying pump has the function of fully emulsify