Qualitative and quantitative analysis method for sulfur hexafluoride (SF6) gas discharge decomposition product

Abstract

The invention discloses a qualitative and quantitative analysis method for a sulfur hexafluoride (SF6) gas discharge decomposition product. The method comprises the following steps of: sampling; performing qualitative and quantitative analysis on a sample by a gas chromatograph-mass spectrograph, wherein a quadrupole rod quality detector is adopted, and a chromatographic column is a CP-Sil 5 CB capillary column. Compared with the prior art, the method can be used for detecting decomposition components comprehensively, detecting eight components including CF4, C2F6, CO2, SO2F2, SOF4, SOF2, SO2 and H2S synchronously, and performing fast recognition and accurate quantitative analysis on the compound. The detection on the SF6 decomposition product assists in an operator to know the insulating state inside electrical equipment so as to judge failure causes accurately.

Description

technical field [0001] The invention belongs to the field of analysis and detection, and specifically relates to a qualitative and quantitative analysis SF 6 A method of gas discharge decomposition products. Background technique [0002] SF 6 The gas has the characteristics of stable chemical properties, safety and non-toxicity, good insulation and arc extinguishing performance at room temperature, making it widely used in various electrical equipment as an excellent insulating medium. However, as the operating time of electrical equipment increases, various insulation failure problems will appear, which is characterized by partial discharge of the insulation medium inside the equipment before breakdown. [0003] SF 6 Under the action of partial discharge, the gas will decompose to produce low fluoride, these metastable substances and O in the equipment 2 or H 2 O further reacts to form SO 2 f 2 、SOF 4 、SOF 2 , SO 2 、H 2 S, S 2 f 10 O, HF, CF 4 and other produc...

AI Technical Summary

Problems solved by technology

The IEC60480-2004 standard recommends using Porapak Q packed column for separation, but from the characteristic chromatogram ( figure 1 ) can be seen that SO 2 f 2 The retention time and SF 6 are similar, the two come out at the same time, and cannot be completely separated

At the same time, the column cannot detect other decomposition products such as SOF 4 and H 2 S

And if the application number is 201010134902.6 "a kind of analysis of SF in electrical equipment 6 The Gas Pro chromatographic column recommended in the "method of decomposition products" patent, although it can achieve SO 2 f 2 with SF 6 separated, but SOF 2 Easily converted to SO in the column 2 and cannot be detected, and its effect on the SOF 4 detection of

[0007] 2) Accurate characterization is not easy

If there is no standard gas or some components come out together, it will cause difficulties in accurate determination

[0008] 3) Quantitative mutual interference

Gas chromatography can only perform integral calculation on the complete separation peak shape. If the target compounds cannot be completely separated during the detection process, the peak shapes will be partially superimposed or even completely overlapped, and accurate quantification will not be possible, and there will be interference between them.

[0009] 4) Insufficient detection limit

Detection of SF by infrared spectroscopy 6 Discharge decomposition products, although there is no need to separate various components, but its detection limit is higher than that of gas chromatography, and products with lower concentrations cannot be detected

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