变压器油中溶解微量糠醛的激光拉曼光谱检测方法

研究变压器油中溶解微量糠醛含量的检测方法及其应用,对运行变压器油纸绝缘老化评估具有重要意义。激光拉曼光谱(LRS)技术作为微量液体检测的有效手段,已经在很多领域得到了广泛应用。本文应用Gaussian 09W程序构建了糠醛分子仿真模型,分析其拉曼振动特性,进而证明了拉曼光谱检测糠醛分子的可行性;应用共聚焦拉曼技术搭建了激光拉曼光谱液体检测试验平台;结合萃取技术研究了糠醛分子的拉曼光谱检测特性,建立了基于特征频谱和最小二乘法对糠醛含量进行定量检测的方法。最后,应用激光拉曼光谱方法对不同糠醛含量的变压器油样进行检测,并与实验室高效液相色谱法(HPLC)的检测结果进行对比,对比结果表明:结合萃取技术的激光拉曼光谱能有效地对变压器油中溶解微量糠醛进行定量检测,为实现变压器油中糠醛含量的快速检测提供了一种方法。

Detection of Trace Furfural Dissolved in Transformer Oil Using Laser Raman Spectroscopy

It is of great importance in studying new methods to accurately detect the concentration of furfural dissolved in transformer oil for assessing the aging degradation of insulating paper. As an effective means for detecting trace liquid, laser Raman spectroscopy (LRS) has already been applied in many fields. The simulation model of furfural molecule, which was used to analyze the Raman vibration characteristics of furfural molecule, was built by Gaussian 09W software. And the feasibility of detecting furfural molecules by LRS was verified in theory. Based on Raman spectroscopy technology, LRS liquid detection test platform was built in the laboratory. Utilizing extraction technique, the Raman spectroscopy detection characteristics of the furfural dissolved in oil were studied on this platform. The quantitative analysis method was then built based on the characteristic spectra and the least squares method. At last, transformer oil samples with different furfural concentrations were detected by LRS test platform. The test results were compared with those measured by high performance liquid chromatography (HPLC). It is shown that LRS with extraction can quantitatively analyze the trace furfural dissolved in transformer oil effectively, which proposes a new way to fast detect furfural concentration in transformer oil.