低温环境绝缘子热风清洗热应力安全阈值研究

Study on Thermal Stress Safety Threshold of Low Temperature Environment Insulator Hot Air Cleaning

摘要: 围绕低温条件下采用热风方式清洗接触网绝缘子时的热应力安全限值问题，选取陶瓷、玻璃以及复合材料绝缘子作为研究对象，借助有限元数值仿真技术，深入探讨了热风清洗过程中的热–流–固多物理场耦合作用机制。采用高压水射流冲洗配合热风干燥的联合作业模式，设置了多组不同的环境温度与热风温度组合工况，系统性地研究了绝缘子表面应力与位移的分布规律。数值模拟结果表明，在低温环境中，陶瓷材质和玻璃材质的绝缘子对温度差异表现出较高的敏感性，当热风温度与环境温度之差超过某一临界数值时，绝缘子表面的应力水平将逼近材料的抗弯强度极限，从而产生损伤破坏的风险。具体而言，陶瓷绝缘子的安全温差上限应控制在60℃以内，玻璃绝缘子的安全温差上限应控制在55℃以内。相比之下，复合绝缘子展现出优异的耐温变性能，即便热风温度达到90℃以上，其表面产生的应力仍然明显低于材料的强度阈值，能够维持安全稳定运行状态。本研究成果为低温环境下绝缘子清洗工艺参数的优化设计提供了重要的理论依据，对于确保接触网电力系统的安全可靠运行具有重要的指导意义。

Abstract: Focusing on the safety limit of thermal stress when cleaning contact network insulators with hot air under low-temperature conditions, ceramic, glass, and composite insulators were selected as research subjects. Using finite element numerical simulation technology, the thermal-fluid-solid multiphysics coupling mechanism during the hot air cleaning process was thoroughly investigated. A combined operation mode involving high-pressure water jet flushing and hot air drying was adopted, with multiple sets of different ambient and hot air temperature combinations systematically studied to analyze the distribution patterns of stress and displacement fields on insulator surfaces. Numerical simulation results indicate that in low-temperature environments, ceramic and glass insulators exhibit high sensitivity to temperature differences. When the temperature difference between hot air and ambient conditions exceeds a critical threshold, the stress level on insulator surfaces approaches the bending strength limit of the materials, posing a risk of damage. Specifically, the safe temperature difference limit for ceramic insulators should be kept below 60˚C, while that for glass insulators should be below 55˚C. In contrast, composite insulators demonstrate excellent thermal resistance, with surface stress levels significantly below the material strength threshold even at hot air temperatures exceeding 90˚C, enabling safe and stable operation. These findings provide crucial theoretical support for optimizing cleaning process parameters in low-temperature environments and hold significant guiding implications for ensuring the safe and reliable operation of contact network power systems.