2.1 Sicherheit von Energieträgern
Filtern
Dokumenttyp
- Vortrag (7)
- Posterpräsentation (6)
- Zeitschriftenartikel (3)
- Beitrag zu einem Tagungsband (3)
- Sonstiges (1)
Sprache
- Englisch (20) (entfernen)
Schlagworte
- Safety (5)
- Acoustic emission (4)
- Aerial robot (3)
- Gas tomography (3)
- Hydrogen (3)
- Plume (3)
- TDLAS (3)
- Accelerometers (2)
- Bending tests on pipe segments (2)
- Continous monitoring (2)
Organisationseinheit der BAM
- 8.1 Sensorik, mess- und prüftechnische Verfahren (20) (entfernen)
Eingeladener Vortrag
- nein (7)
The monitoring of oil and gas pipelines by means of distributed fibre optic sensors is becoming common. The most recent development in the field of fibre optic sensing is the distributed acoustic sensing (DAS), which allows to detect and to localize third party threats to pipelines. For this purpose, fibre optic telecommunication cables located close to the pipelines are usually used. However, DAS carries a far greater potential for continuous condition monitoring of pipelines.
The interdisciplinary research project AGIFAMOR (Ageing Infrastructures – Fibre Optic Monitoring of Pipes) at BAM investigates a new technical approach to extend the application field of DAS towards the detection and localization of acoustic signals that indicate critical alterations and certain damage scenarios originated from within the pipeline or the pipe wall. Therefore, the optical fibre sensors are applied onto the pipe itself and the application procedure towards an optimal acoustic signal transduction is optimized.
A number of laboratory scale experiments were performed focusing on the signal transmission of acoustic signals as well as the detection of damage in the pipe wall by means of DAS. Furthermore, real-scale tests on a pipeline DN100 of 38 m length have been carried out at the BAM test site for technical safety (BAM-TTS) to study the detection and localization of leaks and of changing flow profiles due to corrosion or sedimentation processes.
The monitoring of oil and gas pipelines by means of distributed fibre optic sensors is becoming common. The most recent development in the field of fibre optic sensing is the distributed acoustic sensing (DAS), which allows to detect and to localize third party threats to pipelines. For this purpose, fibre optic telecommunication cables located close to the pipelines are usually used. However, DAS carries a far greater potential for continuous condition monitoring of pipelines.
The interdisciplinary research project AGIFAMOR (Ageing Infrastructures – Fibre Optic Monitoring of Pipes) at BAM investigates a new technical approach to extend the application field of DAS towards the detection and localization of acoustic signals that indicate critical alterations and certain damage scenarios originated from within the pipeline or the pipe wall. Therefore, the optical fibre sensors are applied onto the pipe itself and the application procedure towards an optimal acoustic signal transduction is optimized.
A number of laboratory scale experiments were performed focusing on the signal transmission of acoustic signals as well as the detection of damages in the pipe wall by means of DAS. Furthermore, real-scale tests on a pipeline DN100 of 38m length have been carried out at the BAM test site for technical safety (BAM-TTS) to study the detection and localization of leaks and of changing flow profiles due to corrosion or sedimentation processes.
Leaking methane (CH4) from infrastructures, such as pipelines and landfills, is critical for the environment but can also pose a safety risk. To enable a fast detection and localization of these kind of leaks, we developed a novel robotic platform for aerial remote gas sensing. Spectroscopic measurement methods for remote sensing of selected gases lend themselves for use on mini-copters, which offer a number of advantages for inspection and surveillance over traditional methods. No direct contact with the target gas is needed and thus the influence of the aerial platform on the measured gas plume can be kept to a minimum. This allows to overcome one of the major issues with gas-sensitive mini-copters. On the other hand, remote gas sensors, most prominently Tunable Diode Laser Absorption Spectroscopy (TDLAS) sensors have been too bulky given the payload and energy restrictions of mini-copters. Here, we present the Unmanned Aerial Vehicle for Remote Gas Sensing (UAV-REGAS), which combines a novel lightweight TDLAS sensor with a 3-axis aerial stabilization gimbal for aiming on a versatile hexacopter. The proposed system can be deployed in scenarios that cannot be addressed by currently available robots and thus constitutes a significant step forward for the field of Mobile Robot Olfaction (MRO). It enables tomographic reconstruction of gas plumes and a localization of gas sources. We also present first results showing its performance under realistic conditions.
Acoustic emission testing
(2018)
Four-point bending tests were carried out to analyze the acoustic characteristics of damage development in pipe segments made of steel, grade S355J2H, being 2.5 m long with an outer diameter of 168 mm and 16 mm wall thickness. To induce stable crack growth, the pipe segments were pre-damaged by a 90°circumferential notch in the middle of the pipe length. While the pipe was quasi-statically loaded, microscopic damage and plastic deformation accumulated to form a macroscopic crack that grew through the pipe wall until leakage. For acoustic emission (AE) monitoring, four broadband sensors of type VS 900 M were mounted close to the notch. Continuous AE signal detection was performed by the non-threshold method. Advantages and disadvantages of the non-threshold AE monitoring compared to a commonly employed method analyzing only signals exceeding a predefined threshold are discussed. The results of AE analysis are compared to additional information on the crack growth detected by the direct current potential drop (DCPD) technique. These studies were carried out in the course of the interdisciplinary research project AGIFAMOR, Ageing infrastructures - distributed acoustic monitoring of pipes at BAM.
In this paper, we present an autonomous aerial robot to reconstruct tomographic 2D slices of gas plumes in outdoor environments. Our platform, the so-called Unmanned Aerial Vehicle for Remote Gas Sensing (UAV-REGAS) combines a lightweight Tunable Diode Laser Absorption Spectroscopy (TDLAS) sensor with a 3-axis aerial stabilization gimbal for aiming on a versatile octocopter. The TDLAS sensor provides integral gas concentration measurements but no information regarding the distance traveled by the laser diode's beam or the distribution of the gas along the optical path. We complemented the set-up with a laser rangefinder and apply principles of Computed Tomography (CT) to create a model of the spatial gas distribution from these integral concentration measurements. To allow for a rudimentary ground truth evaluation of the applied gas tomography algorithm, we set up a unique outdoor test environment based on two 3D ultrasonic anemometers and a distributed array of 10 infrared gas transmitters. We present first results showing the 2D plume reconstruction capabilities of the system under realistic conditions.
In this paper, we present an autonomous aerial robot to reconstruct tomographic 2D slices of gas plumes in outdoor environments. Our platform, the so-called Unmanned Aerial Vehicle for Remote Gas Sensing (UAV-REGAS) combines a lightweight Tunable Diode Laser Absorption Spectroscopy (TDLAS) sensor with a 3-axis aerial stabilization gimbal for aiming on a versatile octocopter. The TDLAS sensor provides integral gas concentration measurements but no information regarding the distance traveled by the laser diode's beam or the distribution of the gas along the optical path. We complemented the set-up with a laser rangefinder and apply principles of Computed Tomography (CT) to create a model of the spatial gas distribution from these integral concentration measurements. To allow for a rudimentary ground truth evaluation of the applied gas tomography algorithm, we set up a unique outdoor test environment based on two 3D ultrasonic anemometers and a distributed array of 10 infrared gas transmitters. We present first results showing the 2D plume reconstruction capabilities of the system under realistic conditions.
The feasibility study „AGIFAMOR. Ageing infrastructures – distributed acoustic monitoring of pipes” is an interdisciplinary research project at BAM internally financed from 2015 to 2018. Therefore, the quite young fibre optic sensing technology of distributed acoustic sensing (DAS) was investigated to possibly be extended towards a global condition monitoring system for pipelines operating in real time.
DAS is a highly dynamic fibre optic sensing technology based on the method of coherent optical time domain reflectometry (C-OTDR). DAS allows capturing strain changes in the range of kHz. For the experimental work, the most suitable application yielding an optimum sensitivity was proven by wrapping a standard single-mode silica fibre around the pipe.
The DAS sensitivity was investigated regarding the detection of 1) incidents that initiate propagation of acoustic waves in the pipe wall, 2) changes inside the pipeline causing altered flow and 3) damage development in the pipe wall. Therefore, several testing setups in laboratory as well as in real scale were realized. For comparison purposes, experiments were accompanied by acoustic emission analyses and by measurements with accelerometers.
DAS was found to be very sensitive to gas ignition and its propagation across the pipe. Furthermore, the ability of DAS to detect and localize acoustic signals associated with pipeline leakage was demonstrated. The detection of crack formation and propagation within the pipe wall by means of DAS was studied during bending tests on several pipe segments, but was not proven so far with certainty. As expected, these studies turned out as the most difficult challenge due to the random occurrence and transient nature of microscopic damage phenomena.
Feasibility study: Continuous monitoring of pipes using distributed acoustic and fibre optic sensors
(2018)
The feasibility study „AGIFAMOR. Ageing infrastructures – distributed acoustic monitoring of pipes” is an interdisciplinary research project at BAM internally financed from 2015 to 2018. Therefore, the quite young fibre optic sensing technology of distributed acoustic sensing (DAS) was investigated to possibly be extended towards a global condition monitoring system for pipelines operating in real time.
DAS is a highly dynamic fibre optic sensing technology based on the method of coherent optical time domain reflectometry (C-OTDR). DAS allows capturing strain changes in the range of kHz. For the experimental work, the most suitable application yielding an optimum sensitivity was proven by wrapping a standard single-mode silica fibre around the pipe.
The DAS sensitivity was investigated regarding the detection of 1) incidents that initiate propagation of acoustic waves in the pipe wall, 2) changes inside the pipeline causing altered flow and 3) damage development in the pipe wall. Therefore, several testing setups in laboratory as well as in real scale were realized. For comparison purposes, experiments were accompanied by acoustic emission analyses and by measurements with accelerometers.
DAS was found to be very sensitive to gas ignition and its propagation across the pipe. Furthermore, the ability of DAS to detect and localize acoustic signals associated with pipeline leakage was demonstrated. The detection of crack formation and propagation within the pipe wall by means of DAS was studied during bending tests on several pipe segments, but was not proven so far with certainty. As expected, these studies turned out as the most difficult challenge due to the random occurrence and transient nature of microscopic damage phenomena.
Leaking methane (CH4) from infrastructures, such as pipelines and landfills, is critical for the environment but can also pose a safety risk. To enable a fast detection and localization of These kind of leaks, we developed a novel robotic platform for aerial remote gas sensing - the so-called Unmanned Aerial Vehicle for Remote Gas Sensing (UAV-REGAS).