Cooling Pattern Optimization for shell-type power transformers

The optimization of the pattern of spacers in the cooling of shell-type power transformers can be a significant way to improve the performance of the cooling and insulation systems of shelltype power transformers, and therefore their lifetime. This paper explores the geometry of pressboards to maximize mixing and guiding phenomena and the heat transfer within the oil that surrounds them in the radial section of the windings. A parametric analysis of the spacer geometry has been carried out, specifically focusing on the inclusion in spacers of lateral notch pressboard shapes. It is considered the main distances between vertex generated auxiliary as design parameters. Through Computational Fluid Dynamics (CFD) simulations, it has been assessed the impact of these shapes on the characteristics of the oil flow. The objective pursues to identify the optimal spacer geometry that promotes the highest levels of heat dissipation. On the other hand, the location of these notches along the spacer has been analysed considering manufacturing and interaction with mechanical/electrical limitations.