Study to Predict Blast Load on Structure due to the Explosion of an EHV Power Transformer Using Computational Fluid Dynamics (CFD) based Approach

Abstract

Extra High-voltage power transformers are critical to the electrical infrastructure because they allow for the efficient transfer of power over huge networks. Arcing is the main cause of transformer explosions and fires. The previous work provides a method for evaluating and calculating arc energy and peak overpressure inside the HV Transformer tank owing to electrical failures, which is then used as input for CFD simulation. Computational Fluid Dynamics (CFD) provides a robust numerical approach to modelling blast wave propagation and its interaction with structures. This minimizes the need for full-scale testing by lowering the overall effort and cost of experimentation and data collection. This paper lays the groundwork for a comprehensive analysis & structural design of a 500MVA transformer compound RC firewalls open to the sky subjected to an internal explosion. Using ANSYS Fluent, a CFD simulation is conducted to model blast wave propagation, capturing pressure and temperature variations over time. This Fluid-Structure Interaction (FSI) approach offers critical insights into the structural integrity of blast barriers, aiding in the design of more resilient protection systems. By leveraging CFD-based numerical simulations, key blast parameters such as Incident pressure (Pso), Reflected pressure (Pr), Wave arrival time (ta), and positive and negative phase durations (to, to’), Blast Impulse (I), and Temperature are extracted, analyzed, and compared with the results produced with the TNT-based empirical method. The time-dependent blast load data pave the way for mapping in ANSYS Transient Structural, where the deformation and failure analysis of the transformer blast protection walls will be studied.