FIRE SAFETY ENGINEERING
The development of questions related to Fire Safety Engineering, was launched in Europe by means of the directive 89/106/CEE about building materials and its interpretative document n. 2 “safety in case of fire”. Therefore a new approach to fire safety (the so-called performance-engineering approach) has caught on. It was introduced by means of the ministerial decree 09.05.2007. Until then the deterministic-prescriptive approach was the only officially recognized way to act in fire safety activities. It was based on the implementation of technical rules, which, in order to ensure fire safety, beforehand fixed the measures to be followed, according to the kind of activity. Over the last few years it has been found that this approach, though very simple, has got a number of limits and restrictions. Today the modern technique, several studies –which have been carried out in the field of fire safety- , as well as the development of national and international rules, enable the planner to approach fire safety in a new way, which is freer, more flexible, more adaptable, as the occasion requires. The engineering-performance approach is based on predicting the evolutionary dynamics of a fire, by applying appropriate, physically sound calculus patterns.
The strength of this approach lies in its extreme flexibility, which allows us to simulate even very complex fires, after a number of input data have been taken into account, which are to be set with variable detail, depending on the pattern’s precision.
Currently, in Italy, the use of fire engineering includes:
employments without specific prescriptive rules (industries and risk assessment in activities with a high accident risk)
assessment of equivalent safety in case of claim for derogation from prescriptive rules
Among several CDF (Computational Fluid Dynamics) performance patterns, that the modern technique places at our disposal, the best patterns are numerical patterns or field patterns with arranged parameters. These fit even in highly complex situations. Today, Euler’s numerical patterns, implemented in computational-fluid-dynamics software, are the finest way to simulate fires at our disposal.
The engineering-performance approach is based on predicting the evolutionary dynamics of a fire, by applying appropriate, physically sound calculus patterns.
By means of numerical integration in differential equations, showing combined balances of momentum, energy and matter (Navier-Stokes equation), CDF allows us to find out the calculus of speed vector fields, as well as that of temperature and concentration scalar fields. We have chosen the field pattern FDS (Fire Dynamics Simulation), a software developed by BFRL (Building and Fire Research Laboratory) at NIST (National Institute of Standard Technology). We have chosen this calculus code because of its high levels of reliability in results, these being assured both by its twenty-five years long development, and by its free distribution, which has allowed its spreading and its repeated critical review. FDS has got a post-processor, called Smokeview, that makes data visible. NIST, as well as external institutions, have tested FDS, acknowledging its suitability as a tool of numeric check. NIST used it to study the disaster at the World Trade Center, that was one of FDS’ most important employments.
FIRE SAFETY ENGINEERING ACTIVITY:
RISK ASSESSMENT IN ACTIVITIES WITH A HIGH ACCIDENT RISK
INDUSTRIES-RISK ASSESSMENT IN UNREGULATED ACTIVITIES
ASSESSMENT OF EQUIVALENT SAFETY IN CASE OF CLAIM FOR DEROGATION
USE OF THE PERFORMANCE APPROACH ACCORDING TO THE PROCEDURES PROVIDED FOR BY THE MINISTERIAL DECREE 07/05/2007