Effect of Oxygen and Temperature on Thermal Decomposition Characteristics of C4F7N/CO2/O2 Gas Mixture for MV Equipment

Ye, Fanchao; Zhang, Xiaoxing; Xie, Cheng; Sun, Xiang; Wu, Peng; Xiao, Song; Tang, Ju; Li, Yang

doi:10.1109/access.2020.3043334

Cited by 17 publications

(14 citation statements)

References 18 publications

(29 reference statements)

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“…C 3 F 6 mainly comes from the decomposition of C 4 F 7 N, and CF 3 CN mainly comes from the combination of CF 3 and CN. 28 The content of these two gases is also higher in the C 4 F 7 N/CO 2 /O 2 experimental group.…”

Section: Resultsmentioning

confidence: 80%

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Compatibility and Interaction Mechanism between the C₄F₇N/CO₂/O₂ Gas Mixture and FKM and NBR

et al. 2023

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The C 4 F 7 N/CO 2 /O 2 gas mixture received a great deal of attention for its potential use in eco-friendly gas-insulated equipment (GIE). The evaluation of the compatibility between C 4 F 7 N/CO 2 /O 2 and sealing rubber is necessary and significant considering the high working pressure (0.14−0.6 MPa) of GIE. Herein, we explored the compatibility between C 4 F 7 N/CO 2 /O 2 and fluororubber (FKM) and nitrile butadiene rubber (NBR) for the first time by analyzing the gas components, rubber morphology, elemental composition, and mechanical properties. The interaction mechanism of the gas−rubber interface was further investigated based on the density functional theory. We found that C 4 F 7 N/CO 2 / O 2 is compatible with FKM and NBR at 85 °C, while the surface morphology changed at 100 °C, with white granular and agglomerated lumps appearing on FKM and multi-layer flakes being generated on NBR. The accumulation of the fluorine element occurred, and the compressive mechanical properties of NBR deteriorated after the gas−solid rubber interaction. Overall, the compatibility between FKM and C 4 F 7 N/CO 2 /O 2 is superior, which could be employed as the sealing material for C 4 F 7 N-based GIE.

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Section: Resultsmentioning

confidence: 80%

“…The content of C 3 F 6 and CF 3 CN in the FKM group was significantly higher than that in the NBR group. C 3 F 6 mainly comes from the decomposition of C 4 F 7 N, and CF 3 CN mainly comes from the combination of CF 3 and CN . The content of these two gases is also higher in the C 4 F 7 N/CO 2 /O 2 experimental group.…”

Section: Resultsmentioning

confidence: 83%

Compatibility and Interaction Mechanism between the C₄F₇N/CO₂/O₂ Gas Mixture and FKM and NBR

et al. 2023

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“…This phenomenon revealed an electron concentration-dominated sensing mechanism likely related to the suppression of charge carrier recombination; hence, the low electron concentration results in high conductivity of the adsorption system . Upon exposure to C 4 F 7 N, the preadsorbed oxygen species reacted with C 4 F 7 N molecules and subsequently formed CF 3 and CF 3 COFCN, as shown in Figure a. , The return of released electrons to Ti 3 C 2 T x –SnO 2 led to the increase of both electron concentration and structure resistance. Moreover, the enhancement of the SnO 2 dopant on adsorption ability was revealed through density functional theory (DFT) calculations.…”

Section: Resultsmentioning

confidence: 99%

“…30 Upon exposure to C 4 F 7 N, the preadsorbed oxygen species reacted with C 4 F 7 N molecules and subsequently formed CF 3 and CF 3 COFCN, as shown in Figure 5a. 57,58 The return of released electrons to S2. Notably, the optimal adsorption configuration was observed when the C 4 F 7 N molecule approaches SnO 2 (110) by its −CN group.…”

Section: ■ Introductionmentioning

confidence: 99%

Room-Temperature Detection of Perfluoroisobutyronitrile with SnO₂/Ti₃C₂T_x Gas Sensors

Xiao

et al. 2022

ACS Appl. Mater. Interfaces

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Ti 3 C 2 T x MXene is an emerging two-dimensional transition-metal carbide/nitride with excellent properties of large specific surface and high carrier mobility for room-temperature gas sensing. However, achieving high sensitivity and long-term stability of pristine Ti 3 C 2 T x -based gas sensors remains challenging. SnO 2 is a typical semiconductor metal oxide with high reaction activity and stable chemical properties ideal for a dopant that can comprehensively improve sensing performance. Ti 3 C 2 T x and SnO 2 are investigated for the first time in this study as functional materials for hybridization and room-temperature detection of the gas insulating medium fluorinated nitrile (C 4 F 7 N) with microtoxicity. A Ti 3 C 2 T x −SnO 2 nanocomposite sensor exhibits superior sensitivity, high selectivity, strong anti-interference ability, and excellent long-term stability. The enhanced sensing mechanism is ascribed to the synergistic effect between SnO 2 and Ti 3 C 2 T x and the strong adsorption ability of SnO 2 to C 4 F 7 N similar to bait for fish. We also established an actual leakage scene and demonstrated the feasibility of the Ti 3 C 2 T x −SnO 2 sensor to provide distribution rules with high sensing efficiency for actual engineering applications. The results of this work can expand the gas sensing application of Ti 3 C 2 T x MXene and provide a reference for maintaining C 4 F 7 N-based eco-friendly gas-insulated equipment.

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“…Besides, the dielectric strength of pure C 4 F 7 N gas is twice that of SF 6 and the insulation performance of C 4 F 7 N/CO 2 with 18%-20% C 4 F 7 N is equivalent to that of SF 6 [9]. Comprehensive performance evaluations of C 4 F 7 N on insulation performance [6][7][8][9], decomposition characteristics [10,11] and material compatibility [12] have been conducted, and have demonstrated that C 4 F 7 N has the application potential for both medium-voltage and high-voltage GIE. For example, General Electric successfully developed a 245 kV current transformer and 145 kV gas-insulated switchgear with C 4 F 7 N gas as the insulation medium and put them into trial operation [13].…”

Section: Introductionmentioning

confidence: 99%

Arc decomposition behavior of C ₄ F ₇ N/Air gas mixture and biosafety evaluation of its by‐products

Zhang

et al. 2022

High Voltage

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At present, reports on the arc interruption and decomposition behavior of a C 4 F 7 N/air gas mixture especially the biosafety of its by-products are limited. Herein, a 57% C 4 F 7 N/ 43% air gas mixture was employed as an arc-quenching medium to conduct 200 breaking tests on a load switch (630 A/24 kV). The arc interruption and decomposition behavior of the gas mixture were evaluated, and the biosafety of the decomposition products was assessed based on an acute inhalation toxicity test. It was found that the average arcing time of the 200 breakings was about 10.1 ms and that breakings were basically completed at the zero-crossing of the second or third current half-cycle. The gas mixture after breaking decomposed dramatically (the C 4 F 7 N content decreased by 75.6%), generating a large number of gaseous by-products (CO, CF 4 , C 2 F 6 , C 3 F 8 , CF 3 CN, C 4 F 8 , CO 2 , C 4 F 10 N 2 , C 3 F 6 , C 2 N 2 , etc.) as well as solid by-products (carbon particles). The lethal concentration of 50% (LC50, 4 h) of C 4 F 7 N/air after 200 breakings was 31 ppm (male mice) and 34 ppm (female mice), respectively, and the toxicity was classified as Grade 1. In general, C 4 F 7 N has an arc interruption capability, albeit weaker than that of SF 6 under the same conditions. After breaking, the C 4 F 7 N gas mixture has a relatively high acute inhalation toxicity, and relevant safety protection measures for research or operation personnel are strictly needed.

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Effect of Oxygen and Temperature on Thermal Decomposition Characteristics of C₄F₇N/CO₂/O₂ Gas Mixture for MV Equipment

Cited by 17 publications

References 18 publications

Compatibility and Interaction Mechanism between the C₄F₇N/CO₂/O₂ Gas Mixture and FKM and NBR

Compatibility and Interaction Mechanism between the C₄F₇N/CO₂/O₂ Gas Mixture and FKM and NBR

Room-Temperature Detection of Perfluoroisobutyronitrile with SnO₂/Ti₃C₂T_x Gas Sensors

Arc decomposition behavior of C ₄ F ₇ N/Air gas mixture and biosafety evaluation of its by‐products

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Effect of Oxygen and Temperature on Thermal Decomposition Characteristics of C4F7N/CO2/O2 Gas Mixture for MV Equipment

Cited by 17 publications

References 18 publications

Compatibility and Interaction Mechanism between the C4F7N/CO2/O2 Gas Mixture and FKM and NBR

Compatibility and Interaction Mechanism between the C4F7N/CO2/O2 Gas Mixture and FKM and NBR

Room-Temperature Detection of Perfluoroisobutyronitrile with SnO2/Ti3C2Tx Gas Sensors

Arc decomposition behavior of C 4 F 7 N/Air gas mixture and biosafety evaluation of its by‐products

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Effect of Oxygen and Temperature on Thermal Decomposition Characteristics of C₄F₇N/CO₂/O₂ Gas Mixture for MV Equipment

Compatibility and Interaction Mechanism between the C₄F₇N/CO₂/O₂ Gas Mixture and FKM and NBR

Compatibility and Interaction Mechanism between the C₄F₇N/CO₂/O₂ Gas Mixture and FKM and NBR

Room-Temperature Detection of Perfluoroisobutyronitrile with SnO₂/Ti₃C₂T_x Gas Sensors

Arc decomposition behavior of C ₄ F ₇ N/Air gas mixture and biosafety evaluation of its by‐products