Electro-thermal and mechanical aspects of thermally aged cellulose insulation impregnated with nanofluids. (15th March 2023) - Jacob, Joyce
Highlights: Thermal degradation of cellulose in ester and ester nanofluid. Performance analysis based on breakdown voltage, thermal conductivity and tensile strength measurements. Influence of the nanoparticle concentration on the degradation of cellulose insulation. Abstract: Natural ester nanofluids offer improved dielectric and thermal properties than non-biodegradable mineral oil. In the present work, cellulose samples impregnated with unfilled and nanofilled mineral oil and ester are subjected to thermal aging at 130 °C for 168, 336, 504, and 1200 h under open beaker conditions. After 1200 h of thermal stress, the AC breakdown voltage, thermal conductivity, and tensile strength of natural ester impregnated cellulose is 36.13%, 0.46%, and 1.09 times higher than that of mineral oil impregnated cellulose samples, respectively. Also, the AC Breakdown voltage, thermal conductivity, and tensile strength of 0.02 wt% natural ester nanofluid impregnated cellulose is 37.81%, 1.7%, and 1.1 times higher than that of cellulose impregnated with 0.02 wt% mineral oil nanofluid, respectively. The present measurements demonstrate an improvement in the solid insulation performance with natural ester nanofluids, suggesting a possibility of extended service life of solid insulation in liquid filled high voltage transformers.