Method for monitoring defects of high-temperature steam injection pipeline

Abstract

The invention discloses a method for monitoring defects of a high-temperature steam injection pipeline. An embedded probe is connected with a probe interface of a coupler; an exciting circuit is connected with an excitation source interface of the coupler; an input end of a signal conditioning circuit is connected with a signal conditioning interface of the coupler, and an output end of the signal conditioning circuit is connected with a data acquisition card interface of a computer acquisition and processing system; the excitation source inputs a pulsed excitation signal to the embedded probe through the coupler, excites ultrasonic guided-waves in the pipeline, and generates ultrasonic echoes when encountering the defects, the ultrasonic echoes are transmitted to the embedded probe and are converted into voltage signals through the embedded probe; the voltage signals are transmitted to the signal conditioning circuit to be processed through the coupler and are output to the computer acquisition and processing system which acquires, processes and displays the ultrasonic echo signals containing defect information. The embedded probe can be embedded in an insulating layer of the pipeline, and the insulating layer of the high-temperature steam injection pipeline does not need to be damaged basically, but online detection and long-term monitoring for the defects of the pipeline can be realized, and the defects of the pipeline can be simply and accurately positioned.

Description

technical field [0001] The invention belongs to the technical field of ultrasonic guided wave non-destructive testing, and in particular provides a defect monitoring method for high-temperature steam injection pipelines. Background technique [0002] With the development of the national economy, the use of pipeline transportation is becoming more and more extensive. Pipeline transportation, together with railways, highways, aviation and water transportation, has become the five modern transportation industries. High-temperature steam injection pipelines are widely used in industries such as petroleum, chemical industry, metallurgy, natural gas, thermal power, nuclear power, and heat supply to transmit media such as oil, gas, and steam. Pipeline transportation is developing in the direction of high pressure, large diameter, and long distance. The working environment of the pipeline is becoming more and more complicated and harsh. Due to the use under high temperature and hig...

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Problems solved by technology

There are also equipments that use electromagnetic ultrasonic testing technology for defect detection at home and abroad. The patent application "Ultrasonic Guided Wave Inspection Method for Thick-walled Pipelines in Power Stations" with the application number 200910227225. Instead of using embedded probes, it cannot be applied to high-temperature in-service pipelines; the British PI company has developed the Teletest instrument, which is based on the principle of piezoelectric effect. When testing high-temperature pipelines with coatings, part of the coating must be removed to accommodate pressure. Electric sensors, and ensure that the surface of the pipeline is smooth and smooth, and the piezoelectric chip is not easy to adjust the guided wave mode; the MsS instrument developed by the Southwest Research Institute (SWRI) needs to attach a layer of magnetostrictive functional material-iron-cobalt strip to the surface of the pipeline The detection probe uses two probes to realize the transmission and reception of ultrasonic guided waves. This method has certain detection blind spots, poor defect positioning accuracy, and more cladding damage; the patent application No. 200710053566.0 "A Pipe The defect rapid scanning method and non-destructive testing device" also use dual probes to realize the transmission and reception of ultrasonic guided waves respectively. The detection blind area is relatively large, and the cladding layer is more damaged. In terms of direction control of ultrasonic guided waves, encoders are used. The structure is complex, the detection effect is poor, and the excitation source is realized by single-chip control mode. Compared with the FPGA control mode adopted in this method, the processing speed is slow and the reliability is low; in terms of data acquisition and processing, A / D conversion modules and embedded The computer system carries out signal acquisition, and this method adopts the high-speed data acquisition card to match the data acquisition software based on Labview, has the advantages of good versatility and simple structure, and at the same time, the productized data acquisition card ensures the high stability of the data acquisition process

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