Transformer Explosion Analysis
Oil filled transformers are present in many different applications both onshore and offshore. They represent explosion risks as follows: An electrical failure (e.g. short circuit) in the transformer may produce a strong arc which causes pyrolysis of the insulating oil and causes a breach of the transformer. The gaseous pyrolysis products and oil mist leaks out, and upon exposure of ignition sources may give a secondary explosion affecting the surroundings.
In transformer explosion analysis, we evaluate the potential of gas leaking from the transformer (depending on short circuit current, disconnection time, arc energy). The gas dispersion resulting from the primary transformer explosion is modelled with the CFD tool FLACS, taking into account the ventilation conditions of the area where the transformer is located. The secondary explosion, i.e. ignition of the gas from the decomposed oil, is also simulated with FLACS, and the resulting explosion pressures may be estimated.
Based on the results, mitigating measures can be proposed for lowering transformer explosion risk.
When combined with an assessment of transformer explosion historical frequencies, the personnel, asset or environment risk from transformer explosions may be estimated.