The system of complex corrosion monitoring (CMC) is designed to increase the effectiveness of protection of apparatus and pipelines of the installation from corrosion by automating the supply of reagents that prevent its formation.
Protection of equipment in turn leads to an increase in its service life and turnaround operation, and also reduces the likelihood of an emergency due to corrosion damage to equipment. In addition, a separate subsystem of acoustic emission monitoring allows you to identify defects in the walls of the apparatus of the installation, including those caused by corrosion processes, at an early stage of their development, which in turn leads to a significant increase in the level of safety during operation of these devices. The result of the implementation of the integrated corrosion monitoring system is the direct economic effect of reducing the cost of repairing and replacing equipment and reducing the costs associated with installation downtime or eliminating the consequences of an accident.
Tasks solved by the corrosion monitoring system:
Data collection from various types of sensors, allowing to evaluate the activity of corrosion processes.
Calculation on the basis of the obtained data of the amount of one or another reagent that must be supplied to each zone of the installation in order to effectively protect the equipment of the zone from corrosion.
Controlling metering pumps to deliver the calculated amount of reagent to the oil or oil product.
Providing the operator with a corrosion pattern in each zone of the installation in real time.
The accumulation of data for the purpose of their further analysis and making decisions to increase the effectiveness of methods for protecting equipment against corrosion.
Detection of developing defects (including those caused by corrosion processes) in the apparatus of the installation in real time, informing the operator about the location and danger level of the defects so that they can take timely measures until the apparatus stops working.
The accumulation of information about defects in the apparatus of the installation to specify the locations of work on non-destructive testing.
1. System structure
The system of integrated corrosion monitoring is a hardware-software complex, which consists of two subsystems:
corrosion control subsystems
subsystem acoustic emission control and the central computing station.
2. Corrosion Control Subsystem
Corrosion control subsystem - allows real-time evaluation of metal loss rate (corrosivity) and degree of hydrogen ion activity (pH level) in places where pipelines and equipment are most vulnerable to problems caused by corrosion processes and, according to this estimate, supply reagent ( inhibitor, neutralizer or alkali solution) in the product in an amount necessary to protect the equipment and neutralize corrosive substances.
The subsystem includes measuring, executive and computing elements.
The measuring elements of this system are:
Element
Purpose
Resistometric corrosion rate sensor
Measures the rate of metal loss (allows you to judge the activity of corrosion processes).
Acoustic emission sensor
Measures the level of acoustic waves emitted in the process of corrosion (allows you to judge the activity of corrosion processes).
Samples witnesses (coupons) of carbon and stainless steel
Show the mass fraction of the loss of the metal coupon caused by corrosion processes (since the metal for the manufacture of coupons is selected similar to metal pipelines and devices, then by its state can be judged on the effect of corrosion on the wall thickness of this equipment).
pH meter
It measures the level of activity of hydrogen ions (the pH level makes it possible to judge the tendency of the medium to acidic (too low) or alkaline (too high) corrosion), also finding the pH within certain limits is important for the effective operation of certain reagents (for example, an inhibitor).
Idle sensor
It allows one to estimate the amount of atomic hydrogen that penetrates through the walls of pipelines and apparatus (especially made of carbon steels) and concentrates in the cavities and nonspacities of the metal, leading to delamination and cracking.
