基于超声导波的高温管道壁厚监测技术优化

Optimization of Wall Thickness Monitoring Technology for High Temperature Pipelines Based on Ultrasonic Guided Waves

超声导波技术因可将超声换能器与高温环境隔离而常被用于高温管道的壁厚监测系统,但高温下常规耦合技术失效问题和信号信噪比低的问题影响了测量系统的可靠性和测量精度。设计用于传导超声信号的导波杆,基于声学匹配原理优化干耦合技术,解决高温环境下常规耦合技术的失效问题。提出自适应激励方式和测量数据的乘幂算法以提高高温下测量系统的自适应性和信号信噪比。采用智能分段声速方法对声速进行修正,使高温超声导波测厚系统的测量精度达到±0.03 mm。实验结果表明:在500℃的长期热源环境下,超声波换能器端的温度最高不超过56℃,验证了测量系统在高温环境下的可靠性。

Ultrasonic guided wave technology was often used for wall thickness monitoring system of high tempera-ture pipelines because it could isolate the ultrasonic transducer from the high temperature environment.However,the failure of conventional coupling technology and the low signal-to-noise ratio of the signal at high temperature af-fected the reliability and measurement accuracy of the measurement system.A waveguide rod was designed to con-duct ultrasonic signals.Based on the acoustic matching principle,the dry coupling technology was optimized to solve the failure problem of conventional coupling technology in high temperature environment.The adaptive excita-tion method and the power multiplication algorithm of measurement data were proposed to improve the adaptability and signal-to-noise ratio of the measurement system at high temperature.Intelligent segmentation of the speed of sound was used to correct the speed of sound,and the method made the measurement accuracy of the high-tempera-ture ultrasonic guided wave thickness measurement system reach±0.03 mm.The experimental results showed that the temperature of the ultrasonic transducer end was not more than 56℃at the maximum under the environment of a long term heat source of 500℃,which verified the reliability of the measurement system in high temperature en-vironments.