A new distributed optical fiber sensor system for long-distance oil pipeline leakage and external damage detection is presented. A smart and sensitive optical fiber cable is buried beneath the soil running along the o...A new distributed optical fiber sensor system for long-distance oil pipeline leakage and external damage detection is presented. A smart and sensitive optical fiber cable is buried beneath the soil running along the oil pipeline, which is sensitive to soakage of oil products and mechanical deformation and vibration caused by leaking, tampering, and mechanical impacting. The region of additional attenuation can be located based on the optical time domain reflectometry (OTDR), and the types of external disturbances can be identified according to the characteristics of transmitted optical power. The Golay codes are utilized to improve the range-resolution performance of the OTDR sub-system and offer a method to characterize the transmitted optical power in a wide range of frequency spectrum. Theoretic analysis and simulation experiment have shown that the application of Golay codes can overcome the shortcomings of the prototype based on the conventional single-pulse OTDR.展开更多
近年来,布里渊频域分析技术(Brillouin Optical Frequency Domain Analyzer, BOFDA)已被成功地应用到岩土体、地质及建(构)筑物结构的温度和应变监测中。介绍了BOFDA技术的原理,设计了管道模型的环向收敛变形模型试验,并将BOFDA技术成...近年来,布里渊频域分析技术(Brillouin Optical Frequency Domain Analyzer, BOFDA)已被成功地应用到岩土体、地质及建(构)筑物结构的温度和应变监测中。介绍了BOFDA技术的原理,设计了管道模型的环向收敛变形模型试验,并将BOFDA技术成功应用到管道的环向收敛变形监测中。通过设计不同的感测光缆的布设工艺,对比不同的传感元件和布设工艺之间的性能差异。实验获取了不同围压下管道的收敛变形值以及管道的环向应变,建立了同比例Finite Element Modeling(FEM)模型,模拟各实验情况下管道的各项性能指标,并将数值计算结果与实测结果相对比。对比分析表明,基于BOFDA技术的分布式光纤传感器测得管道外表面为压应变,内表面为拉应变,其监测数值及规律与FEM模拟分析结果表现一致。据此得出:BOFDA技术可有效地应用于管道的环向收敛变形监测,可定性的定位管道应力集中位置及定量的获取应力应变数值。实际工程中,该技术可在管道及隧道的受力变形监测领域推广应用。展开更多
基金This work was supported by the R&D Foundation of China National Petroleum Corporation (CNPC) (No.2001411-4)by the Natural Science Foundation of Henan Province (No. 0511052700).
文摘A new distributed optical fiber sensor system for long-distance oil pipeline leakage and external damage detection is presented. A smart and sensitive optical fiber cable is buried beneath the soil running along the oil pipeline, which is sensitive to soakage of oil products and mechanical deformation and vibration caused by leaking, tampering, and mechanical impacting. The region of additional attenuation can be located based on the optical time domain reflectometry (OTDR), and the types of external disturbances can be identified according to the characteristics of transmitted optical power. The Golay codes are utilized to improve the range-resolution performance of the OTDR sub-system and offer a method to characterize the transmitted optical power in a wide range of frequency spectrum. Theoretic analysis and simulation experiment have shown that the application of Golay codes can overcome the shortcomings of the prototype based on the conventional single-pulse OTDR.
文摘近年来,布里渊频域分析技术(Brillouin Optical Frequency Domain Analyzer, BOFDA)已被成功地应用到岩土体、地质及建(构)筑物结构的温度和应变监测中。介绍了BOFDA技术的原理,设计了管道模型的环向收敛变形模型试验,并将BOFDA技术成功应用到管道的环向收敛变形监测中。通过设计不同的感测光缆的布设工艺,对比不同的传感元件和布设工艺之间的性能差异。实验获取了不同围压下管道的收敛变形值以及管道的环向应变,建立了同比例Finite Element Modeling(FEM)模型,模拟各实验情况下管道的各项性能指标,并将数值计算结果与实测结果相对比。对比分析表明,基于BOFDA技术的分布式光纤传感器测得管道外表面为压应变,内表面为拉应变,其监测数值及规律与FEM模拟分析结果表现一致。据此得出:BOFDA技术可有效地应用于管道的环向收敛变形监测,可定性的定位管道应力集中位置及定量的获取应力应变数值。实际工程中,该技术可在管道及隧道的受力变形监测领域推广应用。