Impact of a distant wildland fire on an LPG tank

During wildland fires, homes located close to the fire can be threatened by the thermal heat flux from the firewall. Several studies have attempted to establish safety distances to protect people and prevent houses from burning, but no research has focused on the possible presence of an LPG tank, which would be supplying fuel for heating or cooking. This topic is, however, very important since hazards from a BLEVE (blast, fireball, fragments) can hurt firefighters during their intervention. This article aims to analyze the impact of a large crown fire on an LPG tank, if a mandatory safety zone of fifty meters is respected. Part One focuses on theoretical considerations aiming to (i) calculate the radiative heat fluxes impacting the tank, and (ii) perform a real scale test. Experiments were performed with a 2 m3 LPG tank 15% full, with a heat flux from a natural gas burner system. The relevance of these test versus a real case is discussed. Results are in very good agreement with the expected heat fluxes, and suggest that there should be no BLEVE risk in the hypothetical conditions.