微水对绝缘油凝点倾点影响的红外光谱检测

探讨微量水分影响机理以便采取有效措施监控绝缘油的运行状态.首先配制不同微水体积分数的绝缘油样，通过实验测试油样的凝点、倾点值；再对每组油样进行红外光谱扫描，得到油样中石蜡质成分（特征波数为722 cm-1）、水分（特征波数为1 640，3 400，3 450，3 615 cm-1）的吸光度值；最后对每组油样中水分子在不同红外波数处的吸光度值、油样中石蜡质吸光度值、油样凝点倾点实验值之间进行皮尔逊相关系数分析，并建立了722，1 640，3 400，3 450，3 615 cm-1波数吸光度值与凝点倾点值的多元线性回归模型，模型的拟合优度分别为0.987 3和0.993 6，模型对油液凝点倾点的预测值与实测值之间的误差范围为0.033%~0.350%.结果表明微水对绝缘油凝点倾点的影响规律是随着油水分散系中水分体积分数增加，油液的凝点倾点值均呈现小幅增加趋势，水分对油样石蜡质成分吸光度值影响作用明显. 

Detecting the Impact of Trace Water on Solidifying Point and Pour Point of Insulating Oil Based on the Infrared Spectrum

It is necessary to investigate the affecting mechanism between the trace water content and solidifying point of insulating oil and to take effective measures to monitor the insulating oil operating status, because the trace water impacts significantly on the solidifying point, pour point of insulating oil in some extent. Firstly,a series of oil samples were made up with different water content, and the experimental values of solidifying point and pour point of oil samples were tested. Then the mid-infrared spectral pictures of the oil samples were obtained, which can acquire the absorbance values of paraffin wax (at the wave number of 722 cm^-1), water (at the wave number of 1640,3 400,3 450,3 615 cm^-1). Finally, absorbance values of water and paraffin wax in characteristic wave number, the experimental data of solidifying point and pour point were combined to calculate the Pearson correlation coefficient and create linear correlation formula between these data and the water content. And according to the measured values of pouring point and solidifying point and infrared spectral absorbing values of oil samples at the wave number of 722,1 640,3 400,3 450,3 615 cm^-1, the multiple linear regression model was constructed. Analysis results show the goodness of fitting model is 0.987 3, 0.993 6 respectively, the error between calculated values and measured values of pouring point and solidifying point is from 0.033% to 0.350%. According to the model, the laws of trace water impact on the solidifying point, pour point of insulating oil were discovered. It is shown that solidifying point pour point values of the oil tend to increase slightly with the increase of moisture content in the oil/water dispersion system, the effect of moisture on absorbance value of paraffin wax is obvious; and the foundation about on-line monitoring of trace water in oil is established.