Application of acoustic intelligent leak detection in an urban water supply pipe network

Different leakage detection technologies present different efficiency and precision of leakage detection in water distribution systems due to their own properties. This study aimed to investigate the use of acoustic sensors to locate the exact position of leaks, which work 24 hours per day in different modes, i.e. fixed installation and mobile exploration. The results showed that the maximum distance between the acoustic sensors installed on the pipeline was 380 m. Field application results indicated that detecting threshold of the distance was 300 m and the intensity ratio of leaking state noise (LSN) to background noise was 1.9 respectively. The pipeline length by manual hunting area (MHA) is 1.3 times longer than the acoustic logger tested area (ALTA), but the detected leakage points in MHA is 20% less than in ALTA. Furthermore, the cost of leakage detection in MHA was about 6,000 yuan/detected leakage point. That in ALTA was about 2,500 yuan/detected leakage point. The case study also indicates that the acoustic logger is a promising tool with the advantage of lower cost and faster detection, compared to manual ground listening with a sound stick. The acoustic leakage detection method can detect the leakage in different sized pipelines, whereas the manual detection was concentrated in small-sized pipelines.