气体压力容器泄漏实时检测与定位技术研究

发布时间：2018-02-11 23:53

本文关键词： 泄漏检测超声波定位传感器阵列加强筋持续性气体泄漏　出处：《天津大学》2016年博士论文　论文类型：学位论文

【摘要】：随着气体压力容器及高压气体传输管道的广泛应用,同时诸如航天器在轨运行等特殊应用环境的兴起,使得在压力系统的稳定运行成为人们日益关注的焦点,而气体泄漏则是威胁此类系统安全运行的最主要且最致命因素之一。当压力容器器壁由于缺陷或外力(如撞击、腐蚀)等原因发生泄漏时,会导致容器结构受损,带来巨大的经济损失,严重时甚至威胁人身安全,带来不可挽回的后果。故如何实时准确的对压力容器泄漏源进行检测定位,具有十分重要的实际意义。压力容器的泄漏一般可分为突发性泄漏及持续性泄漏,目前针对突发性信号(如声发射信号)的实时定位技术已较为成熟,但此类方法很难获得系统的泄漏状况(如是否泄漏,漏孔大小等),且无法对已有泄漏位置进行定位。而对于已有泄漏激发的持续信号,现有的定位检测技术通常需要人工干预,且检测时间长,检测范围小,无法对大型容器进行实时检测。故以上方法均不满足压力容器的在线检测及定位需求,本文针对此问题,通过对泄漏源所激发声波在器壁中传播规律的研究,提出了一种基于声信号的泄漏源实时检测定位技术,并进行了大量的实验论证工作,取得了很多有益的研究成果。本文主要内容可归纳如下:1.研究了泄漏源激发的声波信号的产生机理及传播特性。搭建了模拟泄漏实验平台,讨论并分析了泄漏信号的时频域特性。同时利用有限元仿真手段及激光多普勒测振仪实验平台,获取了实际条件下泄漏声波在器壁结构中传播的时域分布图,研究了泄漏声信号在不同结构不同介质器壁中的传播特性。2.针对一般器壁结构,提出了一种基于超声信号时空相关性的气体泄漏源实时定位方法。通过引入超声导波在压力容器器壁中传播时频散及多模态特性,导出了器壁中一定范围内采集信号的时空相关性与泄漏源位置的关系,实现了对泄漏源的实时精确定位。3.分析了加强筋结构对泄漏声波传播的影响,得到了该结构下泄漏声波特性,并建立了特定加强筋结构对泄漏信号时频域影响的数学模型,导出了泄漏声信号时空域相关度与泄漏源位置的关系表达式,实现了该结构下气体泄漏源的实时精确定位。4.进行了大量实验工作,并通过独立开发软件对实验数据进行计算分析,验证了方法的有效性。
[Abstract]:With the wide application of gas pressure vessel and high pressure gas transmission pipeline, and the rise of special application environment such as spacecraft in orbit, people pay more and more attention to the steady operation of pressure system. Gas leakage is one of the most important and fatal factors threatening the safe operation of such systems. When the wall of the pressure vessel leaks due to defects or external forces (such as impact, corrosion), it will cause damage to the structure of the vessel. Bring huge economic loss, even threaten personal safety seriously, bring irreparable consequence. Therefore, how to detect and locate the leak source of pressure vessel in real time and accurately, The leakage of pressure vessel can be divided into sudden leakage and persistent leakage. At present, the real-time location technology for burst signal (such as acoustic emission signal) has been more mature. However, it is difficult for such methods to obtain the leakage status of the system (such as leakage, hole size, etc.) and it is impossible to locate the location of the existing leakage. However, for the continuous signals excited by the existing leakage, the existing location detection technology usually requires manual intervention. The detection time is long, the detection range is small, and the real-time detection of large vessels can not be carried out. Therefore, the above methods do not meet the pressure vessel online detection and positioning requirements, this paper aims at this problem, Based on the study of the propagation law of acoustic waves excited by the leakage source in the wall of the device, a real-time detection and localization technology of the leakage source based on acoustic signal is proposed, and a lot of experimental work is done. Many useful research results have been obtained. The main contents of this paper can be summarized as follows: 1. The generation mechanism and propagation characteristics of acoustic signals generated by the leakage source are studied. The time-frequency characteristic of the leakage signal is discussed and analyzed. At the same time, using the finite element simulation method and the experimental platform of the laser Doppler vibration measuring instrument, the time-domain distribution map of the leakage sound wave propagating through the wall structure is obtained. In this paper, the propagation characteristics of leakage sound signal in the wall of different dielectric devices with different structures are studied. A method of real-time locating gas leakage source based on time-space correlation of ultrasonic signals is proposed. The time-dispersion and multi-mode characteristics of ultrasonic guided wave propagation in the wall of pressure vessel are introduced. The relationship between the temporal and spatial correlation of the collected signals and the location of the leakage source in a certain range is derived, and the real time accurate location of the leakage source is realized. 3. The influence of the reinforcement structure on the propagation of the leaking sound wave is analyzed. The characteristics of leaky acoustic wave under the structure are obtained, and the mathematical model of the influence of the special reinforcement structure on the time and frequency domain of the leakage signal is established. The expression of the relationship between the spatial correlation of the leakage sound signal and the location of the leak source is derived. The real time accurate location of gas leakage source under this structure is realized. A lot of experimental work is carried out, and the validity of the method is verified by the calculation and analysis of the experimental data through independent development software.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TH49

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