Improving Gas Distribution Tomography: Evaluation of Algorithms and Fan-Beam Measurement Geometries Indoors

Sun, Yuxiao; Chen, Wushuang; Li, Fei; Gu, Zhonglin; Feng, Lijie; Guo, Dongjun; Cai, Hao

doi:10.1109/tim.2023.3240214

Cited by 2 publications

(2 citation statements)

References 42 publications

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“…Here, the local averaged methane concentrations x j at each grid can be calculated by solving the linear equations based on tomographic algorithms. However, ill-conditioned equation problems will be introduced in the process of tomographic reconstruction [ 40 ]. The iterative algorithm is a serviceable means to tackle the ill-conditioned inversion problem.…”

Section: Methodsmentioning

confidence: 99%

Vertical Distribution Mapping for Methane Fugitive Emissions Using Laser Path-Integral Sensing in Non-Cooperative Open Paths

Wang,

Li,

et al. 2024

Sensors

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Observing the vertical diffusion distribution of methane fugitive emissions from oil/gas facilities is significant for predicting the pollutant’s spatiotemporal transport and quantifying the random emission sources. A method is proposed for methane’s vertical distribution mapping by combining the laser path-integral sensing in non-non-cooperative open paths and the computer-assisted tomography (CAT) techniques. It uses a vertical-plume-mapping optical path configuration and adapts the developed dynamic relaxation and simultaneous algebraic reconstruction technique (DR-SART) into methane-emission-distribution reconstruction. A self-made miniaturized TDLAS telemetry sensor provides a reliable path to integral concentration information in non-non-cooperative open paths, with Allan variance analysis yielding a 3.59 ppm·m sensitivity. We employed a six-indexes system for the reconstruction performance analysis of four potential optical path-projection configurations and conducted the corresponding validation experiment. The results have shown that that of multiple fan-beams combined with parallel-beam modes (MFPM) is better than the other optical path-projection configurations, and its reconstruction similarity coefficient (ε) is at least 22.4% higher. For the different methane gas bag-layout schemes, the reconstruction errors of maximum concentration (γm) are consistently around 0.05, with the positional errors of maximum concentration (δ) falling within the range of 0.01 to 0.025. Moreover, considering the trade-off between scanning duration and reconstruction accuracy, it is recommended to appropriately extend the sensor measurement time on a single optical path to mitigate the impact of mechanical vibrations induced by scanning motion.

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Section: Methodsmentioning

confidence: 99%

Vertical Distribution Mapping for Methane Fugitive Emissions Using Laser Path-Integral Sensing in Non-Cooperative Open Paths

Wang,

Li,

et al. 2024

Sensors

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“…However, following that there is a risk of pipeline leakage during use due to corrosion of steel pipes, mechanical damage caused by construction, unsealing of connectors, and welding joint cracks caused by stress. [3][4][5] Therefore, it is crucial to regularly check its technical condition for leakage detection. For the detection scenario of natural gas pipeline leakage inspection, tunable diode laser absorption spectroscopy (TDLAS) is one of the most attractive technologies, [6][7][8] not only because it can provide high sensitivity, good selectivity, and fast response, but also because it can be used for standoff gas detection, where both the personnel and the detection system are at some distance from the object (e.g., natural gas pipelines) being measured.…”

Section: Introductionmentioning

confidence: 99%

Miniaturized and Portable Laser Gas Sensor for Standoff Methane Detection With Non-Cooperative Targets

Li,

Ma,

Wang

et al. 2023

Appl Spectrosc

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A standoff methane (CH4) sensor with actual hard topographic targets (usually called non-cooperative targets) is essential for natural gas pipeline leakage inspection and many other practical applications. To address this requirement, a miniaturized and low-power-consumption gas sensor was developed based on tunable diode laser absorption spectroscopy for standoff CH4 detection with a non-cooperative target. Wavelength modulation spectroscopy with a 1 f normalized 2 f detection method was employed for calibration-free CH4 measurement. A Kalman filter algorithm was used to improve the precision of the detection. The performance of the standoff CH4 sensor was evaluated comprehensively under various conditions, including different incident angles, different hard topographic targets, and different standoff distances. The results show that the measurement precision is 0.107% and the sensitivity is 4.08 parts per million per meter (ppm·m) with a time resolution of 1 s and a standoff distance of 40 m. The detection limit can achieve 1.24 ppm·m at an optimal integration time of 70 s. This sensor can be easily integrated into mobile platforms, which lays the foundation for intelligent leak inspection.

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Improving Gas Distribution Tomography: Evaluation of Algorithms and Fan-Beam Measurement Geometries Indoors

Cited by 2 publications

References 42 publications

Vertical Distribution Mapping for Methane Fugitive Emissions Using Laser Path-Integral Sensing in Non-Cooperative Open Paths

Vertical Distribution Mapping for Methane Fugitive Emissions Using Laser Path-Integral Sensing in Non-Cooperative Open Paths

Miniaturized and Portable Laser Gas Sensor for Standoff Methane Detection With Non-Cooperative Targets

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