Review Article
A Review on Properties, Opportunities, and Challenges of Transformer Oil-Based Nanofluids
Table 1
Basic properties of conducting, insulating, and semiconducting nanoparticles [
26].
| | | Magnetite
(Fe3O4) | Zinc oxide
(ZnO) | Alumina
(Al2O3) | Quartz
(SiO2) | Silica
(SiO2) | Titania
(TiO2) |
| | Density (g/cm3) | 5.17 | 5.61 | 3.96 | 2.65 | 2.20 | 4.2–4.3 | | Electric conductivity (S/m) | | 10– | | | | | | Relative dielectric constant | 80 | 7.4–8.9 | 9.9 | 3.8–5.4 | 3.8 | 100 | | Relaxation time constant (s) | | | 12.2 | 36.3 | | 77 | | Thermal conductivity (W m−1K−1) | 4–8 | 23.4 | 30 | 11.1 | 1.4 | — | Thermal expansion coefficient
at 20°C (µm m−1K−1) | 9.2 | 2.9 | — | 8.1 | 30 | — | | Specific heat (J kg−1K−1) | — | 494 | 850 | — | 670 | — |
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