Containment of Blast Phenomena in Underground Electrical Power Plants.

Abstract

Gas explosion accidents in electrical power plants, can be originated by electrical faults in components containing oil for insulation, such as transformers, junction boxes, etc.; a ground discharge can cause the pyrolisis of part of the oil and the production of a gaseous mixture which generates fires or deflagrations in contact with air. A deflagration gives rise to a pressure shock wave which can propagate throughout the underground plant, if not suitably confined. Flui-dynamic, structural and in some cases fluid-structure interaction analysis are needed to evaluate the overpressures occuring during the blast phenomena and the consequent damages on structural elements. In the present paper a numerical approach to this kind of problems 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-3C is used to perform both fluid and structural fast dynamic computation.