夹套结构内管泄漏声强度及定位研究

发布时间：2018-01-27 13:39

本文关键词： 夹套结构气体泄漏仿真模拟定位实验　出处：《东北石油大学》2017年硕士论文　论文类型：学位论文

【摘要】：在化工行业中,夹套结构设备比较常见,其主体内部通常盛装高温、腐蚀性高的介质。长周期服役会导致夹套设备主体开裂或内壁减薄进而发生泄漏。因其结构特殊性致使夹套结构内管发生泄漏具有隐蔽性,通常会产生严重后果。因此急需一种能够在夹套设备运行时对其进行实时泄漏监测手段来保证夹套设备安全运行。声发射技术因具有实时性和灵敏度高的特点,适合用于此类结构的在线监测。因此,在理论研究和数值分析基础上,确定内管泄漏在外管上产生的振动响应并对振动源进行定位是本技术的研究关键。在此技术路线下,本文主要完成以下工作:1.通过GAMBIT建立二维夹套结构的数值计算模型,采用FLUENT软件对夹套内管小孔泄漏过程进行流场模拟分析,并在流场模拟的基础上进行声场仿真,得到泄漏参数与管道泄漏声强度关系;2.揭示夹套结构内管泄漏在外壁产生振动效应的主要原因,并获得辐射声压与流体湍动曳力产生传感器响应的规律;3.在理论研究和数值分析基础上,建立夹套结构内管泄漏实验系统。首先通过LMS振动与模态测试分析,获得实验系统频率特点,确定实验系统传感器响应的主要声源来源,并通过布置在夹套结构外壁的传感器序列对内管泄漏过程进行监测,获得外壁声发射响应基本规律;4.通过声发射波形分析,选取合适的小波函数,获得表征泄漏特性的主要声特征参量,并获得其随传播距离的演变关系;5.通过声发射线定位分析,确定夹套结构内管泄漏的属于多声源过程,并通过互相关定位分析,较有效地确定泄漏位置。
[Abstract]:In the chemical industry, jacket structure equipment is more common, its main body is usually filled with high temperature. Long period service will lead to cracking of the main body of the jacket equipment or thinning of the inner wall and then leakage. Because of its structural particularity, the leakage of the inner pipe of the jacket structure will be concealed. It is urgent to use a real-time leakage monitoring method to ensure the safe operation of jacket equipment. Acoustic emission technology has the characteristics of real-time and high sensitivity. It is suitable for on-line monitoring of such structures. Therefore, based on theoretical research and numerical analysis. Determining the vibration response of the inner tube leakage on the outer tube and locating the vibration source is the key of this technology. The main work of this paper is as follows: 1. The numerical calculation model of two dimensional jacket structure is established by GAMBIT, and the flow field simulation analysis is carried out by using FLUENT software to simulate the leakage process of small holes in the inner pipe of the jacket. On the basis of flow field simulation, the relationship between leakage parameters and leakage sound intensity is obtained. 2. The main cause of vibration effect on the outer wall of inner tube leakage of jacket structure is revealed, and the law of sensor response caused by radiation sound pressure and fluid turbulent drag force is obtained. 3. On the basis of theoretical research and numerical analysis, the experimental system of inner pipe leakage of jacket structure is established. Firstly, the frequency characteristics of the experimental system are obtained by LMS vibration and modal analysis. The main sound sources of the sensor response of the experimental system are determined, and the basic rules of the acoustic emission response of the outer wall are obtained by monitoring the leakage process of the inner tube by the sensor sequence arranged in the outer wall of the jacket structure. 4. By analyzing the acoustic emission waveform and selecting the appropriate wavelet function, the main acoustic characteristic parameters which characterize the leakage characteristics are obtained, and the relationship between the acoustic characteristic parameters and the propagation distance is obtained. 5. Through the analysis of acoustic emission line location, it is determined that the leakage of the inner tube of the jacket structure belongs to the process of multiple sound sources, and the location of leakage is determined more effectively by the cross-correlation location analysis.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ055.81

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