脉冲激光清洗绝缘子时污秽分布对温度和应力的影响

Analysis of Typical Pollution Temperature Field and Stress Field Under Different Distribution Characteristics of Pulsed Laser

脉冲激光清洗绝缘子时,绝缘子表面污秽的分布特性不同,其整体温度及应力场的分布也不相同。以瓷质绝缘子及其表面污秽为对象,建立有限元模型,对瓷质绝缘子表面不均匀分布和均匀分布污秽分别进行温度场与应力场分析,并以激光试验验证其清洗效果。结果表明,当能量密度为1.41 J/cm^(2),扫描速度为1000 mm/s时,激光照射路径上不均匀污秽可被完全清除,均匀分布污秽的清除率受厚度、焦距位置影响:厚度大,离焦距越近时,温升越高,所受拉应力越大,污秽清除率越高;厚度小,远离激光焦距时,污秽清除率低。因此,清洗均匀分布污秽时,应适时调节入射距离或激光功率。试验表明,激光清洗积聚性不均匀污秽效率最高,表面光滑洁净,其余两种情况下表面均存在残余污秽。

When pulsed laser is used to clean insulators,the distribution characteristics of surface pollution are different,and the distribution of overall temperature and stress field are also different.This paper takes porcelain insulator and its surface pollution as the object,establishes the finite element model,analyzes the temperature field and stress field respectively for the surface non-uniform distribution and uniform distribution of porcelain insulator pollution,and verifies the cleaning effect by laser experiment.The results show that when the energy density is 1.41 J/cm^(2) and the scanning speed is 1000 mm/s,the non-uniform pollution on the laser irradiation path can be completely removed,and the removal rate of the uniform distribution of pollution is affected by the thickness and focal length position.The larger thickness,means the closer the distance from the focus,causes the higher the temperature rise,the greater the tensile stress,and the higher the clearance rate.The smaller thickness,means the farther away from the laser focal length,causes the lower the pollution clearance rate.Therefore,the incident distance and laser power should be adjusted timely when cleaning uneven distribution of pollution.The results show that the laser cleaning is the most efficient and the surface is smooth and clean.In the other two cases,there is residual pollution on the surface.