Open AccessInfluence of thermal ageing and electrical discharges on uninhibited olive oil properties
Author(s) -
Reffas Abderrahim,
Idir Omar,
Ziani Abderrahmane,
Moulai Hocine,
Nacer Azzeddine,
Khelfane Ilhem,
Ouagueni Mourad,
Beroual Abderrahmane
Publication year - 2016
Publication title -
iet science, measurement and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.418
H-Index - 49
eISSN - 1751-8830
pISSN - 1751-8822
DOI - 10.1049/iet-smt.2016.0045
Subject(s) - mineral oil , dielectric , permittivity , materials science , composite material , flash point , asphalt , dielectric loss , viscosity , thermal , mineralogy , chemistry , optoelectronics , metallurgy , thermodynamics , organic chemistry , physics
In recent years, significant attention has been paid to biodegradable vegetable oils as an alternative to mineral insulating oils. This study presents the influence of electrical discharges and thermal stress on the variation of the properties of uninhibited olive oil. This latter constitutes a serious environmentally friendly and renewable substitute for currently used mineral oils. The investigated properties are: dielectric loss factor and permittivity, resistivity, acid number, cinematic viscosity, water content, breakdown voltage, flash point and colour index. To analyse the effect of thermal stress, the uninhibited olive oil was aged in sealed bottles at 110°C for durations up to 716 h. As concerns the electrical stress, series of 200 up to 1600 low energy discharges are applied under 50 Hz alternating divergent electric field. Frequency domain spectroscopy has also been performed in order to assess the oil behaviour in a large frequency range (20 Hz–1 MHz). The real part of the complex dielectric permittivity of oil tends to increase with ageing. The obtained results show an acceptable stability with regard to thermal ageing and even an improvement of the oil key properties when submitted to discharges of controlled low energy level.