两种吸附剂对SF_6分解特征组分吸附的实验与分析

A Comparative Experimental Study on the Interaction of SF_6 Feature Decomposition Products With Alumina and Molecular Sieve kdhF-03

研究吸附剂对在局部放电下SF6分解组分的影响是探究利用分解组分诊断SF6电气设备内部早期绝缘缺陷的重要内容。为此,在建立的特定吸附实验研究平台上,选用SF6电气设备中最常用的活性氧化铝和kdhF-03型分子筛吸附剂,对局部放电(partial discharge,PD)下产生的4种SF6稳定分解特征组分(CF4、CO2、SO2F2和SOF2)进行吸收特性研究,利用气相色谱仪和质谱联用仪定时检测气室内气体残余量,结合吸附量和等温吸附线对吸附机制和作用过程进行了深入分析。结果表明:两种吸附剂几乎不吸附CF4,对CO2略有吸附,但对SO2F2和SOF2有较强的吸附能力,吸附量由多到少依次为SOF2>SO2F2>CO2>CF4。因此,在利用特征组分含量及变化规律辨识SF6气体绝缘设备的绝缘缺陷时,必须考虑吸附剂的影响。实验也发现选用SOF2+SO2整体作为辨识SF6设备内部绝缘缺陷的一种特征组分更有效。

As the decomposition products of SF6 could be affected by the absorbent, it is important to study this kind of influence before we use the decomposition products of SF6 to diagnose faults in SF6 electrical equipment. Two kinds of absorbents were widely used in power apparatus, namely activated alumina and molecular sieve kdhF-03, were chosen as the samples. The absorption characteristics of this two absorbents on the four stable decomposition products of SF6, namely CF4, CO2, SO2F2 and SOF2, were investigated based on our adsorption experiment platform. The concentration of the decomposition products was detected by a gas chromatograph and a gas chromatograph-mass spectrometer. And then the adsorption mechanism and reaction process of the two absorbent were analyzed based on the adsorption capacity and adsorption isotherms. The results show that the two kinds of adsorbents hardly adsorb CF4, and slightly adsorb CO2, but have strong adsorption ability on SO2F2 and SOF2. The adsorption capacity in decreasing order is SOF2〉SO2F2〉 CO2〉CF4. Therefore, the influence of absorbent cannot be ignored when to diagnose the fault in SF6 electrical equipment by decomposition products of SF6. The study also suggests that it is more effective to choose the total concentration of SOF2＋SO2 as the feature parameter to recognize internal insulation defects in SF6 electrical equipment.