On the mechanism of drying the insulation of power transformers in coolant vapors.

Abstract

The physical model of convective drying of insulation of power transformers by coolant vapor in the warm-up phase is considered as a deepening of the moisture evaporation front (the problem of Stefan). An approximate solution is obtained by the LS Leibenzon method for a hollow capillary-porous cylinder that simulates the insulation of high-voltage taps. This made it possible to determine the effect of the coolant, temperature and pressure in the drying chamber on the intensity of the process, as well as the transition time to the evacuation phase. Analytical dependences of the kinetics of drying with coolant vapor were obtained. The proposed physical model qualitatively correctly describes the process.