Clamp-on Ultrasonic Guided Wave Flow Measurement in Thin-walled Pipes

随着气候变化的加剧，水安全变得越来越重要。在英国，每天都有数十亿升水从供水管网中泄漏。[1,2]因此，政府为供水公司设定了减少泄漏的目标。由于对英国水管网络的状况不太了解，因此需要额外的检测泄漏的能力。[2,3]智能水表提供了检测泄漏的能力，并告知人们和企业他们的用水模式，使他们能够减少浪费。然而，目前的技术需要切断现有的管道，这既昂贵又缓慢，阻碍了大规模的推广。夹紧式超声波流量测量在这种情况下很有价值，因为它是非侵入性的，因此管道可以保持完整，从而减少了安装时间和成本。然而，由于在管壁中形成导波，现有的技术并不能有效地应用于小型薄壁管道，比如那些用于家庭供水的管道。使用华威大学[4]开发的新型传感器，在供水管道中普遍存在的15毫米铜管上实现了钳式流量测量。在发射换能器上的单个5个周期爆发会产生6个更长的到达接收器的信号。通过建模和实验，对系统中的波传播的理解已经发展起来，允许使用所有六个到达点进行过境时间差流量测量。目前，正在进行研究以改进传感器的设计，考虑水的温度变化，并确定哪种耦合机制最适合传感器的长期安装。用于测量和执行流量计算的电子设备正在小型化，成为一种低成本、低功耗的基于微处理器的单元。未来的工作将包括利用机器学习来分析用水模式，实现泄漏的自动识别，并产生更直观的信息，将其发送给消费者。b[1]大不列颠。DEFRA。,(2008)。英国水资源战略——未来水资源。伦敦-环境、食品和农村事务部。bbbb10英国。国家基础设施委员会。,(2018)。为更干燥的未来做准备——英国的水利基础设施需求。伦敦-国家基础设施委员会。b[3]贝克，K.（2001）。为水费买单：英格兰和威尔士的水价与公平。[j] .地理学报。26(2),143-164.李志超，Smith, Luke D.和Dixon， Steve M.（2021）微型钳式超声波流量测量传感器的设计。传感器学报，5(6):839 - 839史蒂夫·迪克森，2021年。利用超声导波钳式测量小直径金属管道中的流体流动。可在：https://dx.doi.org/10.21227/5fr9-6x03。

With climate change on the rise, water security is becoming ever more important. Billions of litres of water are leaked from the network every single day in England. [1,2] Consequently, water supply companies have been set leak reduction targets by the government. Since the condition of England's water pipe network is not well understood, additional capacity for detecting leaks is required. [2,3] Smart water metering provides ability to detect leaks and inform people and businesses about their water usage patterns, allowing them to reduce wastage. However, current technology requires cutting into existing pipelines which is expensive and slow, inhibiting the rollout on a large scale.Clamp-on ultrasonic flow measurement is valuable in this circumstance as it is non-invasive, so the pipeline can remain in-tact which reduces installation time and costs. However, existing technology does not work effectively on small, thin-walled pipes such as those used in domestic water suppliesdue to the formation of guided waves in the pipe wall. Using novel sensors developed at the University of Warwick [4], clamp-on flow measurement has been achieved on the 15 mm copper pipes that are ubiquitous in water supply plumbing. [5] A single five cycle burst at the transmitting transducer produces six much longer arrivals at the receiver. Via modelling and experiment, an understanding of wave propagation in the system has been developed which allows transit time difference flow measurement to be made using all six of these arrivals. Currently, research is being conducted to refine the design of the transducers, account for temperature changes in the water, and determine which coupling mechanisms work best for long term installation of the sensors. The electronics for making measurements and performing the flow rate calculation are being miniaturised into a low-cost, low-power microprocessor based unit. Future work will include utilising machine learning to analyse water usage patterns, enabling the automaticidentification of leaks and producing more intuitive information to be sent to the consumer about their usage. [1] Great Britain. DEFRA., (2008). Water Strategy for England - Future Water. London - Department for Environment, Food and Rural Affairs.[2] Great Britain. National Infrastructure Commission., (2018). Preparing for a Drier Future - England's Water Infrastructure Needs. London - National Infrastructure Commission.[3] Bakker, K. (2001). Paying for water: water pricing and equity in England and Wales. Transactions of the Institute of British Geographers. 26(2), 143-164.[4] Li, Zhichao, Smith, Luke D. and Dixon, Steve M. (2021) Design of miniature clamp-on ultrasonic flow measurement transducers. IEEE Sensors Letters, 5(6).[5] Steve Dixon, 2021. Clamp-on measurements of fluid flow in small diameter metal pipes using ultrasonic guided waves. Available at: https://dx.doi.org/10.21227/5fr9-6x03.