Research Of Jacketed Pipe Leakage Detection Method Based On Virtual Instrument

Jacketed pipe is comparatively broadly applied to devices in petrochemical and chemical fiber industry. It is composed of inner pipe and outer pipe. The medium which the inner pipe transports is process material, and the medium outside is mainly steam, hot water, coolants or biphenyl-heat-carrier. Since the inner is in charge of transporting process medium, malfunction frequency is higher than the outer. This paper mainly study the inner pipe of jacketed pipe being leaking, and under this background exploitation of jacketed pipe leakage analogue inspection system and jacketed pipe leakage acoustic emission detection method were studied. The content of studying mainly includes as follows:1. In jacketed pipe leakage process gush stream noise production mechanism and its acoustic characteristics were studied.By applying aerodynamics acoustics and pneumatic jet stream theory in leakage process dynamic fluid source sound production mechanism and its acoustic characteristics has been carried out theoretical analysis. In the meanwhile gush stream noise production mechanism, the sound pressure level of gushing stream noise and their frequency spectrum regularity were also given.2. The total design of jacketed pipe leakage analogue inspection systemThis text introduces hardware composition and software development platform of the virtual instrument. According to reality, the project requires that the analogue inspection system should be designed to imitate most situations of jacketed pipe leakage and be easy to come true.3. Design and exploitation of data collection module in AE analogue inspection systemTo introduce selective method of data collection module, through calling Dynamic Link Library (DLL) under LabVIEW exploitation environment, Non-NI data acquisition card PCI-9812 was successfully driven. Data collection procedure was well done by utilizing the graphical programming language of LabVIEW software.4. Design and exploitation of sound launches the suppositional detecting system data analysis moduleFunctions such as data analysis module data pretreatment, parameter analysis and frequency analysis were realized through LabVIEW programming. The signal wavelet analysis was realized through LabVIEW and MATLAB, which make the research of Wavelet analysis method can be used in the project of actual sound launches.5. The detecting experiment in inner pipe of Sound launches leakageMake sound launches suppositional detecting system in this paper apply to Leakage detecting of jacketed pipe. Do the experiment of pipeline leak and inner pipe of jacketed pipe. Priority has paid to analyze the law that the leakage signal changes with pressure and leakage aperture. Make use of acoustics theoretical to analyze the result of experiment. through building the duct pole assists detecting to grip casing pipe leakage sound launching experiment system. Research Sound launches detecting method of the duct pole assists detecting to grip casing pipe leakage.