Conducting a analysis of the technical condition of steam pipelines, determining the geometric parameters of defects and calculating the remaining life using the IR Thermography

Glukhovskyi, Victor; E.O.Paton Electric Welding Institute; Ukraine

Glukhovskyi, V.Y.; E.O.Paton WEI; Ukraine

ID: ECNDT-0069-2018
Session: Thermography and Thermosonics 2
Room: H1
Date: 2018-06-14
Time: 11:50 - 12:10

Pipeline transport is used for transportation of various media, both gas and liquid, including high-temperature water vapor. Steam lines operate under extreme conditions with a vapor temperature of up to 450 ° C, a pressure of up to 7 MPa and a steam speed of up to 30 m / s, while condensate is formed due to heat loss through the pipe walls. The presence of these factors leads to the formation of walls corrosion and erosion, their thinning and subsequent destruction. Thus, it becomes necessary to perform an express analysis of the technical condition of the steam pipelines without removing them from service using non-destructive testing methods.
Non-destructive testing of steam pipelines has a number of features that do not allow the use of contact methods (ultrasonic, x-ray, magnetic) during their operation. These features include the high temperature of the steam and, as a consequence, the high temperature of the pipe wall. Thus it is expedient to apply remote control methods. The presence of a temperature gradient on the surface of the pipe allows us to apply the IR Thermography, which is remote, fast-acting and highly informative method.
The application of the subsequent mathematical processing of the received information in the form of radiometric tables allows to determine the geometric parameters of the defects (area, depth, thermophysical characteristics), and also to calculate the remaining life of the investigated steam pipelines.
A new approach is proposed for determining the geometric parameters of the defects and calculating the residual life of steam pipelines with a diameter greater than 400 mm with calculation of the defect area and the subsequent solution of the one-dimensional heat conduction problem by the sweep method. This approach allows us to accelerate the procedure for calculating the geometric parameters of defects by solving only a one-dimensional problem.