The Generation of Cavitation for the Removal of Fouling on Submerged Structures Using High Power Ultrasonic Transducers

使用高功率超声波换能器产生空化去除水下结构上的污垢

• 批准号: 2469785
• 金额: --
• 依托单位: Brunel University London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2469785
• 关键词: Generation; Cavitation; Removal; Fouling; Submerged

The accumulation of fouling is a well-known problem in industry which can occur on various different structures depending on the surrounding environmental conditions.The removal of this fouling can be very costly and has resulted in many attempts to mitigate, monitor and remove fouling accumulation in a cost-effective manner. As mitigating techniques cannot guarantee 100% fouling removal of a structure, another approach is to detect and monitor the fouling accumulation to assist in carrying out de-fouling procedures. Current detection methods such as PIGging can also require halts in production to carry out monitoring. In recent years, the application of Ultrasonic Guided Waves (UGW) for fouling detection has been recognised as a promising and non-invasive technique; however, its research is still in its early stages. To complement a non-invasive fouling detection technique, the application of ultrasounds has gained much attention from the industry for in-situ fouling removal. Much research has been conducted to advance the knowledge on the potential uses of ultrasonics across different fouling applications, primarily in reverse osmosis membranes and heat exchangers. However, the optimisation of in-situ ultrasonic fouling removal has not yet been investigated and is also in its infancy. This thesis elaborates on the fundamentals of High Power Ultrasonic Transducers (HPUT) used for generating acoustic cavitation bubbles for achieving ultrasonic cleaning. This knowledge is used in the development of a Finite Element (FE) model which is validated using experimental characterisation of the impedance. The HPUT FE model is used to further understand the design and development of sonotrode attachments for future improvements of the ultrasonic cleaning technique. The FE model is expanded for the prediction of cavitation generation to determine cleaning patterns and is validated in laboratory conditions. By utilising controlled fouling generation capabilities, fouling detection using UGW is investigated and an FE model is used to further characterise variables that can quantify the detection of fouling accumulation with potential applications of monitoring fouling removal. The FE method for fouling removal predictions is used to optimise a HPUT configuration for achieving long-distance fouling removal coverage on a 6.2 meter long, 6 inch schedule 40 carbon steel pipe. The confirmed 4-HPUT configuration is developed for laboratory validation and demonstrates wave propagation up to 3 meters from a single HPUT location

污垢的积累是工业中众所周知的问题，取决于周围的环境条件，污垢的积累可能发生在各种不同的结构上。去除这种污垢可能是非常昂贵的，并且已经导致许多尝试以具有成本效益的方式减轻、监测和去除污垢积累。由于减轻技术不能保证结构的100%污垢去除，另一种方法是检测和监测污垢积累以帮助执行除垢程序。目前的检测方法，如清管，也可能需要停止生产进行监测。近年来，超声导波（UGW）用于污垢检测已被公认为是一种有前途的和非侵入性的技术，但它的研究仍处于早期阶段。为了补充非侵入性污垢检测技术，超声波的应用已经得到了工业界的广泛关注，用于原位污垢去除。已经进行了大量的研究，以提高对超声波在不同污垢应用中的潜在用途的认识，主要是在反渗透膜和热交换器中。然而，优化的原位超声波污垢清除尚未被调查，也处于起步阶段。本文阐述了大功率超声换能器（HPUT）产生声空化气泡实现超声波清洗的基本原理。这方面的知识是用于开发的有限元（FE）模型，这是使用实验特性的阻抗进行验证。HPUT有限元模型用于进一步了解超声焊极附件的设计和开发，以便将来改进超声清洗技术。扩展了FE模型，用于预测空化生成以确定清洁模式，并在实验室条件下进行了验证。通过利用受控的污垢生成能力，污垢检测使用UGW的调查和FE模型被用来进一步验证变量，可以量化的污垢积累与监测污垢去除的潜在应用程序的检测。用于污垢去除预测的FE方法用于优化HPUT配置，以实现在6.2米长、6英寸规格40碳钢管上的长距离污垢去除覆盖。已确认的4-HPUT配置是为实验室验证而开发的，并演示了从单个HPUT位置到3米的波传播