A Study Of The Ship Piping Leakage Detection And Location System Based On Wavelet Transform

The ship piping systems transport many liquid and gaseous materials under theconditions of high temperature and high pressure. The pipes often meet with an accidentof leakage or being broken because of the loosen connecting of the pipes and theirbreakage, the aging and cauterization of pipes themselves, the mechanical vibration ofships, the man-made sabotage and so on. If the piping can not be detected and repairedin time after the leakage, it will cause pollution of the environment, waste of theresource, pecuniary loss even personal injury and other major accidents. Therefore, thestudy of the ship piping leakage detection system is a work which has significanteconomic, social and environmental benefits.In order to solve problems on detecting the leakage of ship piping systems, thispaper sets up the system model through consulting the related data, establishes theexperiment platform for detecting the leakage of ship piping systems based on thenegative pressure wave method and the transient flow real-time control method, imitatesthe condition when ship piping systems works well and it leaks in the practicalapplication and deals with the experimental data. This paper mainly studies severalpoints just as follows:1. Define the method in the ship piping leakage detection system adopted by thispaper, that is, combining the negative pressure wave method and the transient flowreal-time control method; analyze the change of internal pressure and flow of pipesbased on Bernoulli equation to find out the alarm threshold of the pressure and the flowwhen it leaks; by taking pump open as an example to study the change of water hammerpressure wave and its influence on signal acquisition when the pump open or close.2. Apply wavelet transformation technology to the ship piping leakage detectionsystem. Combine wavelet transformation theory and signal processing technology,making full use of advantages of the wavelet transformation when it collects feeblesignals from strong noise signals, selecting appropriate wavelet functions and studyingcollections of characteristic signals in the experiment platform for detecting the leakageof ship piping systems.3. Establish the brainpower real-time supervisory control imitation experimentplatform for detecting the leakage of ship piping systems. In order to accomplish the supervisory control and the design for dealing with signals in the ship piping leakagedetection system, establish the experimental system by combining hardware andsoftware and using pressure transducer, ultrasonic flowmeter and data acquisition cardsto detect the leakage signals, and establish the signal processing system which takesLabVIEW as its platform.4. Analyze the experimental signal of well work, pump open, pump close and theleakage, and obtain the change of the pipe pressure and flow under different conditions.