Читать книгу Alternative Liquid Dielectrics for High Voltage Transformer Insulation Systems - Группа авторов - Страница 54

One of the most significant characteristics to understand the heat transfer property of any insulating oil is thermal conductivity. In order to understand this property of cooling in the transformer, thermal conductivity is measured by using the device KD2 pro at room temperature. Single probe transient hot‐wire method is used to observe the thermal conductivity. The governing equation for thermal conductivity is

(2.9)

Figure 2.8 Comparison of viscosity values of different oil samples.

where “k” is the thermal conductivity, “q” is the heat flow per unit length of the source, and “T₁” and “T₂” are the temperatures of the heat source at times “t₁” and “t₂”, respectively [67]. The thermal conductivity of natural ester is higher than MO because it contains the triglyceride molecular structure.