Vapor clouds

Abstract

Vapor cloud explosions can be devastating events that result in significant damage to property and loss of life. Although vapor cloud explosion hazards are more common for oil and gas facilities, vapor cloudexplosion incidents have occurred at other industrial facilities, such as chemical waste and water treatmentplants [1, 2]. Analysis of vapor cloud explosions presents many challenges to engineers and investigators and requires an understanding of several issues. Some of these issues include the potential phase change of the source via condensation or flashing, dispersion characteristics of the vapor due to atmospheric conditions, and effects of buildings and structures on cloud dispersion and flame front propagation. The scope of thischapter is to discuss several of these key issues and present practical tools that can be used in vapor cloud explosion investigations or hazard analyses. Owing to the potentially large scale of vapor clouds, representative experimental testing is limited and often impractical. Therefore, this chapter focuses on analyticaland computation methodologies that have been validated using experimental tests, and notes several standardized tests that can be used to quantify specific vapor cloud hazards. It is important to note that these methodologies only provide order of magnitude estimates and analysis, and therefore careful interpretation is required. Engineering experience often serves as the most important element to a successful vapor cloud explosion analysis.