| |
 |
UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 18:20 |
 |
|
|
|
Conference: Bucharest University Faculty of Physics 2016 Meeting
Section: Solid State Physics and Materials Science
Title:
Case study on cable insulation degradation processes
used for I & C instrumentation and control with a view to
improving job security
Authors:
Catalin RUSU-ZAGĂR(1), Gilda RUSU-ZAGĂR(2)
Affiliation:
1) University " Politehnica" , Bucharest
2) INCDPM "AlexandruDarabont" , Bucharest, Romania
E-mail
catalinrusuzagar@gmail.com; gildarusuzagar@yahoo.com
Keywords:
insulation, wiring, safety, EVA compund
Abstract:
The safety and health at workplace is a very important objective. In this respect, the study carried out on an EVA compound, conducted in order to estimate the lifetime of instrumentation and control cables used in nuclear power plants, is a must considering the special conditions of the existing environment. Thus, it is necessary to know the reaction of polymeric materials used in the electrical insulation of the conductors under the influence of anthropogenic and environmental factors at the workplaces. The accelerated ageing of the EVA compound, under the simultaneous action of heat and oxygen under pressure, was carried out at the temperatures of 100 oC, 120÷135oC, corresponding inside the chamber to some oxygen pressures of (4 ÷ 2) bar and for the temperature of 135oC the ageing was also performed in the air at the atmospheric pressure. The experiment carried out under the simultaneous action of temperature and oxygen was performed in a special enclosure with automatic control of the values of oxygen temperature and pressure, and the thermal aging at 135oC was achieved in ovens (etuve) with air forced circulation oven. Also, for the determination of the activation energy, chemiluminescence analyses on the fresh material were performed. The experiment was carried out in order to determine the lifetime of instrumentation and control cables. It can be said that this EVA compound can be aged in an accelerated manner under the simultaneous action of heat and oxygen pressure, reducing the aging time, but it is still necessary to obtain a curve of degradation in air at a temperature which highlights the intrinsic phenomena (exp. ageing of the insulating material). At the same time, for the calculations to obtain an equation of degradation, the activation energy for the processes of thermal oxidation obtained from studies of chemiluminescence can be used.
|
|
|
|