Performance evaluation of an oil leakage monitoring system using ultrasonic sensors

Abstract

An oil leakage monitoring system (OLMS), which is used for monitoring oil leakage in a conduit, is tested in this study. The OLMS consists of a pair of ultrasonic flow sensors and a test conduit which is vertically branched from the main conduit located underground. The OLMS can detect fault signals from the ultrasonic sensors to decide if the signals come from oil leakage in the conduit. Leakage detection is enabled by detecting signal quality of transmitted and received ultrasonic signals between the two ultrasonic sensors. The ultrasonic signals can be influenced by working fluid such as air and oil. The OLMS with various conduit diameters (40 mm, 50 mm, 80 mm and 100 mm), materials (SUS 304 and carbon steel) and working fluids (oil and water) was evaluated systematically. 100 random tests were performed to see whether the ultrasonic signals can indicate the instance of air bubble entrainment. The performance evaluation showed that all the OLMS showed the accuracy less than 5 mm with confidence level of 95 %.