Maria Fernandez

Research Abstract:

Assessing Hazardous Materials Spills: An Integrated Model for Pool Spreading and Vaporisation

Large amounts of flammable and toxic materials are stored and transported in storage vessels and pipelines worldwide. They represent a serious hazard as a loss of containment may result in significant fatalities, economical losses and damage to the environment. A report published by the HSE in 2007 analysed loss of containment accidents in the UK industry during the decade of 1991 to 2002. The report concluded that 97% of accidents where attributed to deficient safety management systems. Quantitative risk assessment –QRA– is a safety management tool which allows quantifying the number of fatalities per year, consequence of an accident. Accident modelling therefore plays an important part in QRA, as it provides direct input in the estimation of the risk involved in a determined industrial process.  

A possible outcome from a loss of containment in a vessel or pipeline is the formation of a liquid pool. A liquid pool is formed when volatile material released from a vessel or pipe rainouts onto the ground. As time passes, the pool grows or shrinks in size and exchanges heat and mass with the environment. The variables of interest in the model are the rate at which the pool vaporises, the total mass vaporised over a period of time and the size of the pool. The objective of the work is the further development of a numerical simulation for coupled pool spreading and vaporisation of hazardous liquids. The model will extend its applicability from single components to hydrocarbon mixtures. This will involve simultaneous treatment of flashing components and convective mass transfer, and precise property estimation for hydrocarbon mixtures.

This project is carried out in cooperation with Der Norske Veritas (DNV) an international leading provider of risk management and assessment services.