• 한국소음진동공학회논문집
• /
• 제14권2호
• /
• pp.95-104
• /
• 2004

Leaks in underground pipelines can cause social, environmental and economical problems. One of relevant countermeasures against leaks is to find and repair of leak points of the pipes. Leak noise is a good source to identify the location of leak points of the pipelines. Although there have been several methods to detect the leak location with leak noise, such as listening rods, hydrophones or ground microphones, they have not been so efficient tools. In this paper, accelermeters aroused to detect leak locations which could provide an easier and more efficient method. Filtering, signal processing and algorithm of raw input data from sensors for the detection of leak location are described. A 120m-long and a 70m-long experimental pipeline systems are installed and the results with the systems show that the algorithm with the accelerometers offers accurate pinpointing for leaks location detection. Theoretical analysis of sound wave propagation speed of water in underground pipes, which is critically important in leak locating, is also described.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2003년도 춘계학술대회논문집
• /
• pp.821-826
• /
• 2003

Leaks in underground pipelines can cause social, environmental and economical problems. One of a good contermeasures of leaks Is to find and repair of leak points of pipes. Leak noise is a good source to identify the location of leak points of pipelines. Although there have been several methods to detect the leak location with leak noise, such as listening rods, hydrophones or ground microphones, they were not so efficient tools beca. In this paper, two accelermeters are used to detect leak locations which could provide an easier and efficient method. The filtering, signal processing and algorithm is described for the detection of leak location. A 120m-long pipeline system for experiment is installed and the results with the system show that the algorithm with the two accelerometers gives very accurate pinpointing of leaks. Theoretical analysis of sound wave propagation speed in underground pipes is also described.

• Transactions on Control, Automation and Systems Engineering
• /
• 제3권2호
• /
• pp.89-94
• /
• 2001

This paper presents an approach to leak detection and location of gas pipelines based on a strong tracking filter(STF). The STF has strong robustness against model uncertainties, which will deteriorate the performance of the extended Kalman filter. Hence, much faster and more accurate leak detection and location has been obtained. Computer simulation results demonstrate the effective-ness of the proposed approach.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2004년도 추계학술대회논문집
• /
• pp.327-332
• /
• 2004

Leak noise is a good source to identify the exact location of a leak point of underground water pipelines. Water leak generates broadband noise from a leak location and can be propagated to both directions of water pipes. This sound propagation due to leak in water pipelines is not a non-dispersive wave any more because of the surrounding pipes and soil. However, the necessity of long-range detection of this leak location makes to identify low-frequency acoustic waves rather than high frequency ones. Acoustic wave propagation coupled with surrounding boundaries including cast iron pipes is theoretically analyzed and the wave velocity was confirmed with experiment. The leak locations were identified both by the acoustic emission (AE) method and the cross-correlation method. In a short-range distance, both the AE method and cross-correlation method are effective to detect leak position. However, the detection for a long-range distance required a lower frequency range accelerometers only because higher frequency waves were attenuated very quickly with the increase of propagation paths. Two algorithms for the cross-correlation function were suggested, and a long-range detection has been achieved at real underground water pipelines longer than loom.

• Nuclear Engineering and Technology
• /
• 제51권1호
• /
• pp.155-162
• /
• 2019

To reduce the secondary damage caused by leakage accidents in plant piping systems, a constant surveillance system is necessary. To ensure leaks are promptly addressed, the surveillance system should be able to detect not only the leak itself, but also the location of the leak. Recently, research to develop new methods has been conducted using cameras to detect leakage and to estimate the location of leakage. However, existing methods solely estimate whether a leak exists or not, or only provide two-dimensional coordinates of the leakage location. In this paper, a method using multiple cameras to detect leakage and estimate the three-dimensional coordinates of the leakage location is presented. Leakage is detected by each camera using MADI(Moving Average Differential Image) and histogram analysis. The two-dimensional leakage location is estimated using the detected leakage area. The three-dimensional leakage location is subsequently estimated based on the two-dimensional leakage location. To achieve this, the coordinates (x, z) for the leakage are calculated for a horizontal section (XZ plane) in the monitoring area. Then, the y-coordinate of leakage is calculated using a vertical section from each camera. The method proposed in this paper could accurately estimate the three-dimensional location of a leak using multiple cameras.

• 한국음향학회:학술대회논문집
• /
• 한국음향학회 2004년도 춘계학술발표대회 논문집 제23권 1호
• /
• pp.225-230
• /
• 2004

Leak noise is a good source to identify the exact location of a leak point of underground water pipelines. Water leak generates broadband noise from a leak location and can be propagated to both directions of water pipes. However, the necessity of long-range detect ion of this leak location makes to identify low-frequency acoustic waves rather than high frequency ones. Acoustic wave propagation coupled with surrounding boundaries including cast iron pipes is theoretical analyzed and the wave velocity was confirmed with experiment The leak locations were identified both by the acoustic emission (AE) method and the cross-correlation method. In a short-range distance, both the AE method and cross-correlation method are effective to detect leak position. However, the detect ion for a long-range distance required a lower frequency range accelerometers only because higher frequency waves were attenuated very quickly with the increase of propagation paths. Two algorithms for the cross-correlation function were suggested and a long-range detection has been achieved at real underground water pipelines longer than 300m.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2004년도 춘계학술대회논문집
• /
• pp.985-990
• /
• 2004

Leak noise is a good source to identify the exact location of a leak point of underground water pipelines. Water leak generates broadband noise from a leak location and can be propagated to both directions of water pipes. This sound propagation due to leak in water pipelines is not a non-dispersive wave any more because of the surrounding pipes and soil. However, the necessity of long-range detection of this leak location makes to identify low-frequency acoustic waves rather than high frequency ones. Acoustic wave propagation coupled with surrounding boundaries including cast iron pipes is theoretically analyzed and the wave velocity was confirmed with experiment. The leak locations were identified both by the acoustic emission (AE) method and the cross-correlation method. In a short-range distance, both the AE method and cross-correlation method are effective to detect leak position. However, the detection for a long-range distance required a lower frequency range accelerometers only because higher frequency waves were attenuated very quickly with the increase of propagation paths. Two algorithms for the cross-correlation function were suggested, and a long-range detection has been achieved at real underground water pipelines longer than 300m.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 춘계학술대회
• /
• pp.798-803
• /
• 2004

Leak noise is a good source to identify the exact location of a leak point of underground water pipelines. Water leak generates broadband sound from a leak location and this sound propagation due to leak in water pipelines is not a non-dispersive wave any more because of the surrounding pipes and soil. However, the necessity of long-range detection of this leak location makes to identify low-frequency acoustic waves rather than high frequency ones. Acoustic wave propagation coupled with surrounding boundaries including cast iron pipes is theoretically analyzed and the wave velocity was confirmed with experiment. The leak locations were identified both by the acoustic emission (AE) method and the cross-correlation method. In a short-range distance, both the AE method and cross-correlation method are effective to detect leak position. However, the detection for a long-range distance required a lower frequency range accelerometers only because higher frequency waves were attenuated very quickly with the increase of propagation paths. Two algorithms for the cross-correlation function were suggested, and a long-range detection has been achieved at real underground water pipelines longer than 300m.

• 한국가스학회지
• /
• 제10권3호
• /
• pp.27-33
• /
• 2006

본 논문에서는 가스 파이프라인 내의 누출 현상이 파이프라인 출구 압력 변화에 미치는 영향을 분석하였다. 경사진 지형적 영향을 고려하기 위하여, 보정된 Weymouth 식이 본 연구에서 사용되었다. 누출 영향을 분석하기 위하여, 수평관, 상향 및 하향 경사관 각각에서 누출 현상이 없을 경우와 누출 현상이 발생할 경우에 대하여 출구 압력과 입구 압력에 대한 출구 압력 비율을 비교하였다. 그 후, 누출 위치가 출구 압력에 미치는 영향에 대하여도 모든 파이프라인 경사각에 대하여 분석하였다.

• 비파괴검사학회지
• /
• 제36권5호
• /
• pp.384-390
• /
• 2016

플랜트 배관의 누설감시 시스템은 누설 유무 판단뿐만 아니라 누설의 위치를 신속히 파악하는 것 또한 매우 중요하다. 플랜트 배관의 누설 검출 방법에는 주로 AE(acoustic emission)센서, 마이크로폰어레이 그리고 카메라 영상을 이용한 방법들이 있다. 최근 광역감시 및 원거리감시의 이점이 있는 카메라 영상을 이용한 방법에 대한 연구가 진행되어 왔다. 하지만 기존 카메라 영상을 이용한 방법들은 누설 유무와 대략적인 누설의 위치를 판단하고 있으나 누설이 시작되는 정확한 위치 추정에 대한 연구는 아직 미흡한 상태이다. 따라서 본 논문에서는 카메라를 이용한 누설 검출 방법을 이용해 누설영역을 산출하고 누설 검출 결과를 분석하여 누설 위치를 추정하는 방법을 제안하였으며 실험을 통하여 성능을 평가하였다.