小管道超声在役检测的聚焦超声场研究

Research on Immersion Focusing Ultrasonic Field for In-line Inspection of Small-diameter Pipelines

引入扫描带重叠系数的概念,建立了多探头阵列式、多探头旋转式和单探头旋转反射镜式检测头的不漏检条件;深入 分析了小管道液浸超声检测时的聚焦超声场,建立了相应的数学模型;在此基础上,提出了检测头型式及聚焦探头参数的选 择原则;建立了小管道液浸超声检测的室内测试系统。试验表明,在适当的采样率和系统增益的情况下,单探头反射镜式检测 头可用于小管道的超声在役检测。

The condition of complete coverage of circumference for the pipeline has been extensive studied for a few types of sensor carriers, such as multi-sensor array, rotating multi-sensor array and single sensor rotating reflector through the introduction of concept for coefficient of sweep zone. Turning to immersion testing for small-diameter pipelines, the model of immersion focusing ultrasonic field for small-diameter pipelines has been given. Based on all of them, the fundamental rules for structures and parameters of focusing transducer are put forward. The laboratory measurement system has been set up for immersion testing of small-diameter pipelines. It has been shown that the sensor carrier for single sensor rotating reflector is available for in-line inspection of small-diameter pipelines at the proper sampling frequency and system amplification.