Crosslinking Modelling of the Power Cable Insulation Processing

摘要

During the manufacture of power cables insulated with crosslinkable polyethylene, the hot polymer is applied to the conductor by extrusion, below temperatures of rapid crosslinking. The coated cable passes into a high-pressure tube (filled with nitrogen under pressure of 10 bar) in order to heat up the insulation to temperatures at which the crosslinking agent is highly active. This is the continuous vulcanization (CV) tube. Changes in process variables associated with the CV tube can cause changes in the physical properties, aging characteristics, and especially heat resistance of the cable insulation. Performance of insulating compounds in this area of the crosslinking process can determine maximum output rates of a power cable manufacturing facility. Most power cable manufacturers have determined the optimum operating conditions for their cure tubes through practical experiments. However, the introduction of new resins or different cable constructions often leads to inefficient operation or erroneous evaluation because of the inability to predict performance in the tube. In addition, when using other insulation materials, it is necessary to conduct a series of independent experiments for their characterization. This can often lead to overdesign or underdesign of new equipment. With this point in mind, a mathematical model of the continuous vulcanization (CV) process, which provides a simulation of the process has been developed.