Russian researchers, who deal with diagnostics of heat and power objects, developed a technique for remote noncontact monitoring of municipal underground heat pipelines. The innovative technique detects corrosion in metal pipes, which is the main reason for their high breakdown rate, and helps finding defect locations without starting excavation works.

Research team from St. Petersburg performs diagnostics of underground heat pipelines by means of remote techniques of measuring heat and acoustic parameters and electrometry. Electrometric monitoring, for instance, gives information about insulating coating of pipelines and helps estimating damage, which corrosion did to pipes. Scientists know how to make results of their observations more statistically reliable – they simply combine electrometry and measuring heat parameters.

One of electrometric techniques is called “excitation-at-the-mass method” and in a few words it looks like this: electric current from a generator gets to an underground pipeline, while second electrode of feeding line is grounded far away from that place. Researchers measure electromagnetic field at the surface along pipe’s axis, and this field tends to change in places, where pipeline insulation is broken – in these places current “flows” from the pipe to the ground. Scientists claim that excitation-at-the-mass method can accurately show places, where pipe insulation cover is disturbed, and corrosion is likely to begin.

Another electrometric technique – natural electrical field method – allows defining location of corrosion zones on pipe exterior more exactly and estimating intensity of corrosion process. Scientists admit that these techniques are common for field exploration geophysics; however, these methods were adapted for using in urban environments, where dense residential development, asphalt coating and high level of industrial noise interfere measurements.

 

 

During one of the recent experiments, conducted in St. Petersburg, researchers estimated, how transmitter electrodes affected monitored electromagnetic field of a pipeline, and recommended most effective schemes of measuring equipment. Research, performed by Russian scientists, allows enhancing existing technologies, improving their accuracy and expanding range of use for remote sensing methods. These interesting and promising results will be reported at the meeting of American Geophysical Union in Toronto.

Researchers also emphasize the fact that developed diagnostics technique for underground pipelines is actively in use in St. Petersburg. Moreover, similar works with slight modifications were performed at heat networks of Vologda, Cherepovets, Vorkuta, Ukhta, Syktyvkar and some other cities of Russian Federation, and results of these experiments were used in developing programmes for major repairs and reconstruction of public utilities in these cities.

Source: RIA Novosti

Kizilova Anna