RESEARCH OF LEAK DETECTION AND LOCATION METHOD FOR HEAT OIL PIPELINES

摘要

It is an effective method to detect leak using negative pressure wave (NPW). When heat oil pipelines in low transfer throughput and complex operational changes, usually noise will be very strong and feature signal of leak is difficult to extract. In order to improve quality of parameter information collected, a novel method based on Independent Component Analysis (ICA) is proposed to separate and filter weak aim signal from noise. In this paper signal processing principle based ICA is introduced and experiments are illustrated. The experimental results show that signal-to-noise ratio (SNR) of processed pressure signals is raised effectively and feature signal become easy to extract. At the same time, in heat oil pipelines pressure wave velocity is affected by oil and axial temperature drop. Location usually has obvious error. To solve this problem axial temperature drop is analyzed and velocity of NPW was revised. By means of Newton-Cotes integration method location formula is modified. The real experimental results show that the improved located formula made location accuracy from 2.5% to 1.0%.