Permeation Characteristic Comparison of the Components in the Rejuvenation Liquid of Polyethylene

Cable injection rejuvenation technology is a means to improve the insulation performance of aging cables and extend their service life. The permeability characteristics and rejuvenation effect evaluation of rejuvenation fluids are key research areas in the application of cable rejuvenation technology. The present work compares and analyzes existing cable rejuvenation fluids, and proposes a method for analyzing the infiltration characteristics that can be used in the selection of rejuvenation fluids. Molecular dynamics simulations were conducted on the main components of three rejuvenation fluids, Phenyl-methyl-dimethoxy-silane, Trimethyl-methoxy-silane, and Diphenyl-dimethoxy-silane, to obtain their diffusion coefficients in polyethylene. Furthermore, finite element simulations of chemical substance transfer were conducted to compare the infiltration characteristics of the rejuvenation fluid components in polyethylene. The results indicate that the diffusion coefficient ratios of the three organosilicon compounds in polyethylene are 1.49:5.62:1, and the concentration ratios at the same observation point on the seventh day after infiltration are 6.7:160:1. The diffusion coefficient can be used to evaluate infiltration characteristics.