针对天然酯绝缘油杂散气体运行产气规律不清、产气机理不明的情况,该文搭建了电热联合应力及循环流动实验平台,探究电场强度、温度以及流动性对天然酯绝缘油杂散产气的影响;开展了基于ReaxFF的分子动力学模拟,从宏观和微观两个层面详细...针对天然酯绝缘油杂散气体运行产气规律不清、产气机理不明的情况,该文搭建了电热联合应力及循环流动实验平台,探究电场强度、温度以及流动性对天然酯绝缘油杂散产气的影响;开展了基于ReaxFF的分子动力学模拟,从宏观和微观两个层面详细阐述了天然酯绝缘油的电热联合应力分解产气过程及机理。实验和仿真结果表明:随着电场强度的增大,杂散气体含量按指数趋势增长,高场强油样的H_(2)、CO、CO_(2)高出0 k V/mm油样3~5个数量级;杂散气体含量随着温度的升高而增大;增加油样循环流动,杂散气体含量显著降低;在电热分解过程中,电场强度升高和时间增长会加剧酯分子的分解,H_(2)和CO_(2)是整个电热分解过程中的主要气体产物;不同甘油三酸酯分子之间产气路径存在较小差异。该成果为实现植物绝缘油中溶解气体全面诊断,有效评估变压器运维状态提供了理论指导与技术参考。展开更多
Traditional mineral oil has long served as a liquid insulating medium in power transformers.However,its low fire resistance,poor biodegradability and dependence on finite fossil fuel resources,along with its low flash...Traditional mineral oil has long served as a liquid insulating medium in power transformers.However,its low fire resistance,poor biodegradability and dependence on finite fossil fuel resources,along with its low flash point,contribute to transformer explosions and fires.To overcome these limitations,developing insulating liquids with high flash points and self-extinguishing properties is essential.Although natural ester-based insulating oils and silicone oils have been proposed as alternatives,their performance requires further optimisation,and their application in transformers remains challenging.This study examines the combustion characteristics of three novel self-extinguishing fluorinated silicone oils using combustion experiments and reactive molecular dynamics simulations.The results demonstrate that methylfluorinated and hydrofluorinated silicone oils exhibit superior self-extinguishing performance compared to mineral oil and natural ester-based insulating oils.Simulation analyses indicate that fluorinated silicone oils generate silicon-oxygen polymers upon ignition,which influence subsequent chain reactions.However,hydroxyfluorinated silicone oil releases a higher concentration of key free radicals,intensifying chain reactions and diminishing its self-extinguishing capability.As a result,its self-extinguishing performance is significantly weaker than that of methylfluorinated and hydrofluorinated silicone oils.These findings provide valuable insights for the development of advanced liquid insulating media as potential replacements for mineral oil.展开更多
文摘针对天然酯绝缘油杂散气体运行产气规律不清、产气机理不明的情况,该文搭建了电热联合应力及循环流动实验平台,探究电场强度、温度以及流动性对天然酯绝缘油杂散产气的影响;开展了基于ReaxFF的分子动力学模拟,从宏观和微观两个层面详细阐述了天然酯绝缘油的电热联合应力分解产气过程及机理。实验和仿真结果表明:随着电场强度的增大,杂散气体含量按指数趋势增长,高场强油样的H_(2)、CO、CO_(2)高出0 k V/mm油样3~5个数量级;杂散气体含量随着温度的升高而增大;增加油样循环流动,杂散气体含量显著降低;在电热分解过程中,电场强度升高和时间增长会加剧酯分子的分解,H_(2)和CO_(2)是整个电热分解过程中的主要气体产物;不同甘油三酸酯分子之间产气路径存在较小差异。该成果为实现植物绝缘油中溶解气体全面诊断,有效评估变压器运维状态提供了理论指导与技术参考。
基金supported by the National Natural Science Foundation of China(52407170)the Natural Science Foundation of Hubei Province(2024AFB306).
文摘Traditional mineral oil has long served as a liquid insulating medium in power transformers.However,its low fire resistance,poor biodegradability and dependence on finite fossil fuel resources,along with its low flash point,contribute to transformer explosions and fires.To overcome these limitations,developing insulating liquids with high flash points and self-extinguishing properties is essential.Although natural ester-based insulating oils and silicone oils have been proposed as alternatives,their performance requires further optimisation,and their application in transformers remains challenging.This study examines the combustion characteristics of three novel self-extinguishing fluorinated silicone oils using combustion experiments and reactive molecular dynamics simulations.The results demonstrate that methylfluorinated and hydrofluorinated silicone oils exhibit superior self-extinguishing performance compared to mineral oil and natural ester-based insulating oils.Simulation analyses indicate that fluorinated silicone oils generate silicon-oxygen polymers upon ignition,which influence subsequent chain reactions.However,hydroxyfluorinated silicone oil releases a higher concentration of key free radicals,intensifying chain reactions and diminishing its self-extinguishing capability.As a result,its self-extinguishing performance is significantly weaker than that of methylfluorinated and hydrofluorinated silicone oils.These findings provide valuable insights for the development of advanced liquid insulating media as potential replacements for mineral oil.
