Insulation Strength and Decomposition Characteristics of a C6F12O and N2 Gas Mixture

Abstract

This paper explores the decomposition characteristics of a new type of environmentally friendly insulating gas C 6 F 12 O and N 2 mixed gas under AC voltage. The breakdown behavior of 3% C 6 F 12 O and N 2 mixed gas in quasi-uniform field was investigated through a breakdown experiment. The self-recovery of the mixed gas was analyzed by 100 breakdown experiments. The decomposition products of C 6 F 12 O and N 2 under breakdown voltage were determined by gas chromatography-mass spectrometer (GC-MS). Finally, the decomposition process of the products was calculated by density functional theory, and the ionization energy, affinity, and molecular orbital gap of the decomposition products were also calculated. The properties of the decomposition products were analyzed from the aspects of insulation and environmental protection. The experimental results show that the 3% C 6 F 12 O and N 2 mixed gas did not show a downward trend over 100 breakdown tests under a 0.10 MPa breakdown voltage. The decomposition products after breakdown were CF

The Influence of O2 on Decomposition Characteristics of c-C4F8/N2 Environmental Friendly Insulating Gas

“…In order to explore the discharge decomposition path of c-C 4 F 8 and the effect of O 2 on its decomposition, a thermodynamic and kinetic combination method was used to analyze the orientation and mechanism of the reaction based on density functional theory (DFT). With regard to theoretical knowledge of calculations, it has been described in detail in our previous work [30,31]. The Dmol3 package was used to process exchange-related interactions using a local density approximation (LDA-PWC) approach to optimize the structure of c-C 4 F 8 and O 2 [25].…”

“…The solvent delay time was 0.1 min; the detector voltage threshold was 100 and the voltage was 0.1 kV. The specific steps can be found in [26][27][28][29][30]. Figure 3 shows the surface of the ball electrode before and after breakdown of pure c-C4F8, c-C4F8/N2 gas without O2 and with 3% O2.…”

“…In particular, there will be a significant increase in the temperature at the moment of breakdown, and the temperature at the center of the breakdown arc may reach 1000 k. All kinds of free radicals generated by ionization or dissociation of c-C4F8 molecules can produce a series of new products by secondary reactions, mainly CF4, C2F6, C3F8, C2F4 and C3F6. Figure 10 shows the molecular model of the above decomposition product after optimization, and the bond length bond angle parameter is basically the same as that given in [30]. All kinds of free radicals generated by ionization or dissociation of c-C 4 F 8 molecules can produce a series of new products by secondary reactions, mainly CF 4 , C 2 F 6 , C 3 F 8 , C 2 F 4 and C 3 F 6 .…”

“…All kinds of free radicals generated by ionization or dissociation of c-C 4 F 8 molecules can produce a series of new products by secondary reactions, mainly CF 4 , C 2 F 6 , C 3 F 8 , C 2 F 4 and C 3 F 6 . Figure 10 shows the molecular model of the above decomposition product after optimization, and the bond length bond angle parameter is basically the same as that given in [30]. Table 4 shows the chemical equations of decomposition products, energy changes and activation energy.…”

Partial discharge characteristics of C6F12O/CO2 mixed gas at power frequency AC voltage

“…The decomposition products of the mixed gas after breakdown are analyzed to obtain fluorocarbons such as CF 4 , C 2 F 6 , C 3 F 6 . 12,13 Referring to Table I, considering the GWP, cost and toxicity, C 6 F 12 O is a good choice. Previous studies have found that C 6 F 12 O with N 2 mixed breakdowns are more likely to produce solid products, CO 2 is more suitable as a buffer gas.…”