基于超声导波的管道内结垢在线监测与去除技术研究

With many advantages in transporting fluid, pipelines play an irreplaceable role in national economy and social development. Being harassed by the fouling within pipelines for a long time, the industries have to remove the fouling regularly or even replace the pipelines, which lead to enormous economic loss and environmental pollution. Once the fouling is not removed properly or in time, there may be blockage, deformation or even other safety issues like burst in the pipelines. Also, fouling can cause contamination in the productions of many industries, which cannot be ignored. According to the defects and blindness of the traditional fouling removal methods, a research project has been proposed for the technique of online monitoring and removal for the fouling within the pipelines based on ultrasonic guided waves. The technique is to monitor and evaluate the fouling within a pipeline, then remove the fouling precisely and in time according to the evaluation results and system models. The project studies the model of propagation law of ultrasonic guided waves in a pipeline with the presence of fouling, the model of fouling removal process using ultrasonic guided waves, the signal processing and recognition methods for the reflection signals, the optimized design of system sensors. The system is expected to be able to monitor the fouling with the distance no less than 30 m, detect and identify the fouling with cross section more than 5% of the pipeline, remove fouling more than 10 m around within 1 hour for more than 80% cases.

管道在运送流体方面具有诸多突出优势，在国民经济和社会发展中发挥着不可替代的作用。管道内结垢问题长期困扰着工业界，这不仅迫使工业界定期除垢甚至更换管道，造成巨大的经济损失和环境污染，而且一旦除垢操作不及时或不当，还可能造成管道堵塞、变形或爆裂等严重的安全生产问题。此外，管道内结垢还会对诸多行业产品造成不可忽视的污染。针对传统除垢方法的缺陷和盲目性，本课题提出了基于超声导波的管道内结垢在线监测与去除技术，在线监测并评估管道内结垢状况，根据评估结果及系统模型，对结垢进行精确和及时的清除。课题研究超声导波在实际管道中存在结垢情况下的传播特性模型，研究超声导波除垢过程模型，研究系统反射信号的处理和识别方法，对系统传感器进行优化设计。力争对管道内结垢状况监测距离不低于30米，能检测并识别管道截面5%以上的结垢，除垢范围不低于10米，对80%以上管道内结垢情况清除时间不多于1小时。

管道在运送流体方面具有诸多突出优势，在国民经济和社会发展中发挥着不可替代的作用。管道内结垢问题长期困扰着工业界，这不仅迫使工业界定期除垢甚至更换管道，造成巨大的经济损失和环境污染，而且一旦除垢操作不及时或不当，还可能造成管道堵塞、变形或爆裂等严重的安全生产问题。此外，管道内结垢还会对诸多行业产品造成不可忽视的污染。针对传统除垢方法的缺陷和盲目性，项目组提出了基于超声导波的管道内结垢在线监测与去除技术。项目组通过建立基于超声导波的管道内结垢检测模型，根据模型利用实验管道搭建系统开展了检测实验；搭建基于超声导波的除垢实验系统；构建含垢管道的横向剪切应力模型；提出基于泄漏超声导波空化效应的超声导波除垢机理，并提出除垢选频依据；设计用于除垢的超声导波换能器并对传感器进行优化；建立换能器准轴对称模式和非轴对称模式两种激励分布在充液管道中的传播特性，为均匀性除垢提供了理论基础；通过分析超声导波在载流管道内的传播特性、泄漏到液体内的声压分布特性以及引发的空化效应，建立了超声导波在载流管道中传播过程模型，搭建了基于超声导波的载流管道除垢实验系统，给载流管道在线除垢过程提供一定的参考与指导；通过提出一种创新型基于FPGA的超声导波管道除垢方法并进行除垢验证实验，为管道除垢技术提出了新的思路和新的方法。