Performance Study of FBG Hoop Strain Sensor for Pipeline Leak Detection and Localization

Pipelines provide a convenient mode of transportation of fluids, and their safe usage is one of the foremost concerns. In our previous work, a hoop strain-based negative pressure wave (NPW) approach was proposed to detect and localize pipeline leakages by employing a series of bare fiber Bragg grating (FBG) sensors. To enhance the leakage detection capability especially for small leakage rate cases, a FBG hoop strain sensor with adjustable sensitivity has been developed to measure the pressure drop induced by pipeline leakage. This paper analyzes the performance of the developed FBG hoop strain sensors with consideration of NPW energy attenuation. The detectable range [xR] of each hoop strain sensor is investigated, and thus the sensor quantity can be determined. A case study is conducted on a 32-km pressurized pipeline to demonstrate the analysis procedure, with further discussion of different pipeline parameters' influences on [xR]. The results show that the smallest detectable leakage rate can be enhanced at least 30% by setting mounts of sensors. The most effective way to enhance the overall performance of the leakage detection system is to develop higher-sensitivity FBG hoop strain sensors.