High-temperature pipeline wall thickness online monitoring device and method based on ultrasonic waveguide

Abstract

The invention discloses a high-temperature pipeline wall thickness online monitoring device and method based on an ultrasonic waveguide. A lath-shaped waveguide structure is adopted as a heat buffer structure for cooling and heat insulation, meanwhile, based on non-frequency-dispersion horizontal shear guided wave signal transmission in the waveguide structure, piezoelectric ultrasound of a to-be-monitored high-temperature pipeline is subjected to long-distance, on-line and real-time monitoring, and the pipeline with the temperature reaching 1000 DEG C can be monitored; the waveguide structureand the to-be-monitored high-temperature pipeline make contact through pressure dry coupling, a good sound transmission effect is achieved, and the problem of a failure of a liquid coupling agent atthe high temperature is solved; meanwhile, a piezoelectric ceramic wafer in a d24 mode is adopted, thus the lighter and cheaper effects are achieved, power consumption is low, the efficiency is high,and surface bonding and fixing are also more convenient and firmer compared with a thickness coupling mode; and the high-temperature pipeline wall thickness online monitoring device can be permanentlymounted on the high-temperature pipeline during test run of the high-temperature pipeline, the safety state of the high-temperature pipeline is continuously obtained for a long time, the detection frequency can be increased, and the error caused by recoupling of a probe each time is also decreased.

Description

technical field [0001] The invention relates to the technical field of ultrasonic nondestructive testing, in particular to an ultrasonic waveguide-based on-line monitoring device and method for the wall thickness of a high-temperature pipeline. Background technique [0002] Pipeline wall thickness measurement is an important means of pipeline corrosion monitoring. It can detect hidden safety hazards in pipelines in time, and guide maintenance and replacement reasonably, especially for high-temperature pipelines under extreme conditions, such as petrochemical, coal chemical, nuclear power and other energy industries. Its corrosion rate and potential safety hazard are greater, and online monitoring of its wall thickness has great scientific significance and market value. Traditional industrial thickness measurement methods include magnetic flux leakage method, eddy current method, ray method, and ultrasonic method. Among them, the ultrasonic method is the most widely used. Its...

AI Technical Summary

Problems solved by technology

[0003] However, general piezoelectric ultrasonic probes can only work normally for a long time at less than half of its Curie temperature (<150°C). For pipelines in high-temperature environments, conventional piezoelectric transducers face the problem of depolarization failure. Although there are many researches on high-temperature-resistant ultrasonic transducers, the technology is still not mature enough, and it is still in the stage of laboratory exploration. Long-term continuous measurement

And at high temperature, the conventional liquid ultrasonic coupling agent will also volatilize, causing many difficulties in traditional ultrasonic measurement

As for electromagnetic ultrasound, although it can realize non-contact measurement at high temperature, it has high power consumption, low energy conversion efficiency, large volume and weight, and is not suitable for long-term online monitoring.

In many cases, the monitoring of high-temperature pipelines can only wait until the planned shutdown, and the shutdown cost of many enterprises is high, seriously affecting economic benefits, and the time period is also long, which is very inconvenient

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