小径薄壁换热管污垢多通道超声检测及微弱信息获取技术研究

Heat exchange tubes are widely used in industrial production, and its fouling problem is ubiquitous. At present, the precise determination of its fouling is still difficult to achieve. The ultrasonic detection method is a good method, because it is safe and nondestructive. However, the ultrasonic reflection of small-diameter thin-wall heat exchange tubes are complex, with the influence of object texture, distribution and physical properties. So it is difficult to obtain stable and accurate data about weak and fuzzy fouling information. This paper intends to study the fouling detection and weak information acquisition of small-diameter thin-wall heat exchange tubes. Based on the improvement of fouling detection mechanism analysis, finite element modeling and acoustic characteristics research, a low cost and high applicability multi-channel detection scheme was designed. Combined with the detection method, the integrated processing of the multi-channel ultrasonic detection signal of the fouling was realized by means of improved wave atom transformation and other tools. With analyses of the detection scheme and object characteristics, Whale Optimization Algorithm (WOA) and Entropy Analysis theory were used to improve Imperialist Competitive Algorithm (ICA), then improved ICA was combined with sparse decomposition method and data fusion to achieve accurate quantitative acquisition of fouling and its non-uniform features. By using simulation and platform evaluation experiments, the proposed method system was verified and further improved. This research will provide fully-fledged application solution for ultrasonic detection of fouling, and contribute to the improvement of industrial production efficiency and safety.

换热管作为工业生产中广泛使用的重要材料，普遍存在着结垢问题，但目前实现其污垢的准确测量仍困难重重。超声波检测以其安全无损等特点成为一种很好的方法，但小径薄壁换热管声反射情况复杂，加之受被测管材质、分布与物理特性等影响，对微弱模糊的污垢信息进行稳定准确的获取存在困难。故此本课题拟针对小径薄壁换热管污垢检测及微弱信息获取展开研究：在完善污垢检测机理分析、有限元建模和声学特性研究基础上，实现低成本、适应性强的多通道超声检测方案设计；结合检测方式，以改进波原子变换等工具实现污垢多通道超声检测信号的综合处理；分析检测方案与对象特征，以鲸鱼捕猎和熵分析思想改进帝国竞争优化算法，并以之结合稀疏分解与数据融合，实现污垢及其非均匀特征的准确定量获取；通过仿真和平台评价实验，检验和完善课题方法体系，为污垢超声检测提供成熟应用方案，并为工业生产效率与安全性的提高做出贡献。

工业生产领域中的管式换热设备普遍存在结垢问题，但目前对其结垢情况的准确测量仍存在困难。本项目组在国家自然科学基金项目资助下，对小径薄壁换热管污垢超声检测问题进行了研究，主要工作包括：对换热污垢生成机理及超声传播特点进行分析，实现并完善有限元建模，从超声导波检测和时域反射角度进行检测主要因素与超声传播特性关联分析，开展相关实验研究，增强数据积累；在检测信号特性分析基础上，以改进完备总体经验模态分解降噪方法和改进帝国竞争优化稀疏分解方法实现小径薄壁换热管污垢超声检测信息的准确获取；针对适用于小径薄壁换热管污垢的多通道时域反射检测和超声周向导波检测方式进行研究与分析，完成多通道检测装置与方案设计，进一步丰富与完善换热污垢检测方法体系。.本项目已完成预期研究目标，获得预期研究成果。在后续时间项目组将进一步完善和扩展相关成果，为下一步研究奠定坚实基础。