CONTAINMENT OF BLAST PHENOMENA IN UNDERGROUND ELECTRICAL-POWER PLANTS

Gas explosion accidents in electrical power plants can be originated b y electrical faults in components containing oil for insulation, such as transformers, junction boxes, etc. A ground discharge can cause the pyrolysis of part of the oil and the production of a gaseous mixture, which can generate fires or deflagrations in contact with air. A defl agration gives rise to a pressure shock wave, which can propagate thro ughout the underground plant if not suitably confined. Fluid-dynamic, structural and, in some cases, fluid-structure interaction analyses ar e needed to evaluate the overpressures occurring during the blast phen omena and the consequent damages on structural elements. In the presen t paper, a numerical approach to this kind of problem is proposed and applied to a case study dealing with a typical transformer cell in an underground power plant. The fluid-structure interaction code PLEXIS-3 C is used to perform both fluid and structural fast dynamic computatio n. (C) 1998 Elsevier Science Ltd.