Research On Pipeline Ultrasonic Internal Inspection Technology Based On Phased Array Technology

The oil transportation pipes are important transportation equipment in energy transport.With the increase of pipelines in service,the safe transportation of pipelines has attracted more and more attention.With the increase of in-service pipelines,the problem of pipeline safety transportation has attracted more and more attention.With the increase of pipeline service time,the probability of corrosion,cracks,pits and other defects increases.Defective pipelines are easy to cause pipeline leakage accidents,resulting in a large waste of resources,social and economic losses,environmental pollution and serious harm to people’s lives.In order to solve the problem of pipeline defects,ultrasonic phased array method is proposed to detect pipeline defects.The ultrasonic phased array detection technology can control the ultrasonic sound beam,and detect the pipeline through the deflection and focusing of the sound beam,and flexibly change the number of array elements and detection angle,with fast detection speed and high sensitivity.Aiming at the ultrasonic phased array pipeline detection technology,based on the ultrasonic propagation characteristics and combined with the sound field propagation law of ultrasonic phased array transducer,the sound field of one-dimensional linear phased array is theoretically deduced,and the sound field distribution is theoretically simulated and analyzed.Combined with the propagation law of sound field in the pipeline and the deflection and focusing characteristics of ultrasonic phased array sound beam,the propagation path of annular phased array sound field in the pipeline is analyzed.Using the reverse phase matching method,the deflection and focusing delay rule of annular phased array is deduced.The experimental object selection Φ168 pipeline,using the small annular ultrasonic phase control array module to perform vertical focus,deflecting focus detection experiment.The experiments verify the effectiveness of the deflection focusing delay rule,and analyze the relationship between the number of working array elements,deflection angle,echo amplitude and detection error.In the experiment,the Φ168 pipe with corrosion defects was detected.The relationship between focal length,number of array elements,deflection angle and defect detection effect is analyzed,and the detection ability of annular phased array is verified.The experimental results show that using the deflection focusing delay rule to control the annular ultrasonic phased array element can achieve the effect of sound beam deflection focusing,and the focusing detection effect is better than that of the non-focusing mode.With the increase of the deflection angle of the annular ultrasonic phased array,the amplitude of the echo signal shows a trend of stability at first and then a gradual decrease.With the increase of focusing distance,the detection error decreases first and then increases.When the focus is near the outer wall of the pipeline,a better focusing effect can be achieved.The defect detection error increases gradually with the increase of deflection angle.The deflection angle can maintain a small error within ± 10 °.