Chemical, Physical and Electrical Properties of Aged Dodecylbenzene: Thermal Ageing of Mixed Isomers in Air

Hosier,; Vaughan,; Sutton,; Davis, Fred J.

doi:10.1109/tdei.2007.4339470

Cited by 29 publications

(73 citation statements)

References 24 publications

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“…After aging without copper, no significant oxidation was observed. This should be contrasted to the previous small volume (5 ml) samples [8], which showed appreciable oxidation; here a reduced oxidation rate is a consequence of the larger volume and smaller surface area to volume ratio which clearly reduces oxygen diffusion. Aging with copper results in significant carbonyl (C=O) and hydroxyl (O-H) bands, whilst previous small volume samples indicated only carbonyl bands.…”

Section: A Uv/vis Spectroscopycontrasting

confidence: 78%

“…Separate samples (150 ml) were aged in fan ovens in tall glass jars at 135 o C for periods of 72, 168 and 336 h, which were covered with a Petrie dish to minimize evaporation. To selected samples copper was added (in the form of 0.1 mm thickness sheet), total surface area 96 cm 2 to be consistent with earlier work [8][9][10][11]. Some oils were tested after centrifuging to remove visible particulate matter, whilst others were homogenized before testing.…”

Section: Methodsmentioning

confidence: 99%

“…1 shows spectra from oils which have been homogenized. On aging, the absorption edge shifts to longer wavelengths (arrowed) and the oil is visibly yellowed [3,8,9]. Aging with copper for 72 h is broadly equivalent to aging without copper for 168 h, thus copper is clearly accelerating the aging process.…”

Section: Methodsmentioning

confidence: 99%

“…Aging with copper for 72 h is broadly equivalent to aging without copper for 168 h, thus copper is clearly accelerating the aging process. After 72 h aging in the presence of copper, a weak absorption at 680 nm (labelled "A") was detected which is indicative of the presence of copper carboxylates [8].…”

Section: Methodsmentioning

confidence: 99%

“…Similarly, the aging behaviour of dodecylbenzene [8,9] vegetable oils [10] and silicone oils [11] has also been studied and all of this work has led to a number of "universal" indicators of aging, which can be used for routine condition monitoring. However, most of these studies did not consider the effects of aging on high field properties, such as electrical conductivity and electrical breakdown strength, which would be more applicable for plant.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Effect of aging on the physical, chemical and dielectric properties of dodecylbenzene cable oil

Hosier

Koilraj

Vaughan

2016

2016 IEEE International Conference on Dielectrics (ICD)

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Abstract-In high voltage transformers a liquid dielectric, such as mineral oil, serves both as an electrical insulator (in conjunction with paper) and as a coolant. Similarly, in paper/oil cables mineral oil or dodecylbenzene in conjunction with paper serves as the electrical insulator. In such systems, the oil serves as a convenient medium for sampling to indicate plant health. In the current study dodecylbenzene was aged at elevated temperatures in the presence of air and copper. A battery of tests was then performed to assess the changes in physical, chemical and electrical properties. After aging the oils were yellowed and oils aged with copper showed oxidation, increased water content and the formation of a precipitate, whilst those aged in the absence of copper showed much less aging. Changes in electrical properties were noted such as increased dielectric loss, increased electrical conductivity and decreased dielectric breakdown strength. It was found that the presence of the precipitate did not affect the electrical properties of the oil.

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Section: A Uv/vis Spectroscopycontrasting

confidence: 78%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Effect of aging on the physical, chemical and dielectric properties of dodecylbenzene cable oil

Hosier

Koilraj

Vaughan

2016

2016 IEEE International Conference on Dielectrics (ICD)

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Influence of oil aging on the space charge dynamics of oil‐immersed paper insulation under a DC electric field

Hao¹,

Tang

Fu³

et al. 2014

IEEJ Transactions Elec Engng

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The formation of space charge in oil/paper insulation system can lead to material degradation in the region of high electric field. Therefore, it is important to understand the factors that affect space charge formation in oil/paper insulation system. In this paper, the effect of oil aging on space charge dynamics in oil/paper insulation system is investigated using the pulsed electroacoustic (PEA) technique under a DC electric field at room temperature. The ultraviolet/visible (UV/vis) spectrum of the oil shifts to longer wavelengths, and the oil acidity increases as the aging time increases. It has been found that the oil property has a significant effect on the space charge distribution in the oil/paper insulation sample. The more the deterioration of the oil, the larger amount of negative and positive charges accumulated in the bulk of the oil/paper insulation sample. The total amount of slow moving charges, the surface trap energy density, and the electric field distortion of the oil/paper insulation sample increased with the degree of deterioration due to oil aging. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

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Copper catalytic effect on the thermal deterioration and surface morphology performance of transformer oil–paper insulation

Hao

Liao

Yang

et al. 2017

IEEJ Transactions Elec Engng

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Transformer failure caused by copper corrosion in oil-paper insulation has been attracting much attention in recent years. It is necessary to get a better understanding the effect of copper on the degradation rate and the microcosmic performance of the oil-paper insulation. In this way, targeted measures could be taken to prevent harm to the transformer. The catalytic effect of copper on the thermal aging rate and the micro-/nano-level morphology of oil-paper insulation aged with and without copper are compared in this paper. The dynamic behavior of copper compounds dissolved in oil and deposited on the insulation paper surface is discussed. Results show that copper plays a catalytic role in the deterioration of oil-paper insulation, and this role becomes obvious in the later stages of aging. Compared to the oil-paper insulation sample aged without copper, in the oil-paper insulation sample aged with copper the oil has higher acidity and higher ultraviolet absorption wavelength. Besides, the degree of polymerization of the paper is lower. Scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) results show that copper is present on the innermost paper surface. SEM and atomic force microscopy clearly show the deposition of copper compounds. Higher deterioration of the paper results in more roughness of the paper surface. The content of copper compounds dissolved in oil was found to be increasing first and then decreasing in the later process of aging. The content of copper compounds deposited on the paper increases significantly when the oil is aged for a long time. The catalytic effect of copper on the thermal aging rate and the surface morphology of oil-paper insulation should be paid more attention even for a noncorrosive oil.

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Chemical, Physical and Electrical Properties of Aged Dodecylbenzene: Thermal Ageing of Mixed Isomers in Air

Cited by 29 publications

References 24 publications

Effect of aging on the physical, chemical and dielectric properties of dodecylbenzene cable oil

Effect of aging on the physical, chemical and dielectric properties of dodecylbenzene cable oil

Influence of oil aging on the space charge dynamics of oil‐immersed paper insulation under a DC electric field

Copper catalytic effect on the thermal deterioration and surface morphology performance of transformer oil–paper insulation

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