热力管道小漏温度场特征标定研究
2016-05-31黄冬冬
黄冬冬



摘要:泄漏特别是小漏预警对热力管道的安全维护具有重要意义。受空间分辨率的影响,分布式光纤传感器对小漏引起的局部温度变化测试精度较低,测量温度与实际温度差异较大。以布里渊光时域反射仪(BOTDR)作为测量手段,提出了一种建立分布式光纤测量温度与实际温度之间对应关系的方法。设计完成了小漏温度场模拟测量实验,通过高斯拟合对测量数据进行特征提取,再用人工神经网络建立测量温度与实际温度的映射模型。结果表明:设计的实验方案可获得代表管道小漏温度分布的先验数据,基于此训练的人工神经网络可确立实际温度场与BOTDR测量温度场的对应关系,提高了光纤测试精度并为泄漏预警策略的制定提供了依据。
关键词:管道泄漏;布里渊散射;高斯拟合;人工神经网络
中图分类号:TN253
文献标志码:A 文章编号:1674-4764(2016)02-0097-07
Abstract:Early warning of leakage, especially small leakage, is significant for safety maintenance of thermal pipeline. Due to spatial resolution, the measuring accuracy of distributed fiber optic sensor for local temperature variation caused by small leakage is low and the measurements are quite different from the actual temperature field. Based on Brillouin optical time domain reflectometer (BOTDR), a new method to establish a mapping relationship between the BOTDR measurements and the actual temperatures is proposed. Laboratory experiments were carried out to simulate small leakage and achieve the measurements of gradient temperature fields. Feature extraction of the measured data is then conducted through Gaussian fitting. With artificial neural network (ANN), a mapping model of the actual and measured temperature features is established. The results demonstrate that: the designed experiment can accumulate enough prior data to derive an ANN model, based on which a mapping relation of the actual temperature field and the BOTDR measurements can be achieved to improve the measuring accuracy of BOTDR and provide a reference to propose warning strategy.
Keywords:pipeline leak; brillouin scattering; gauss fitting; artificial neural network
管道运输是现代工业和国民经济的命脉,具有运输量大、连续、经济、平稳、可靠、占地少、费用低、可实现自动控制等诸多优点,是继铁路、公路、水运、航空运输之后的第五大运输业[1]。中国北方大部分地区实行冬季集中供暖,大大小小的锅炉房生产的热水经过热力管道送达千家万户。热力管道是生命线工程的重要部分,一旦发生泄漏,不仅会使居民采暖受到影响,有时还会危及人身安全。
热力管道泄漏往往由小漏、微漏开始,如果能及时发现,完全可以避免更严重事故的发生。然而,大多数供热管道都埋在地下,查找泄漏点难度非常大,尤其是有些直埋敷设管道,如果找错泄漏点,会给检修人员带来很大麻烦。……
