Method of Predicting Smoke Movement in Atria with Application to Smoke Management

摘要

The paper presents information that can be used for predicting smoke movement fordesign of atrium smoke management systems. NFPA 92B (1991) and the smoke control design book by Klote and Milke (1992) define smoke as the airborne solid and liquid particulates and gases evolved when a material undergoes pyrolysis or combustion, together with the quantity of air that is entrained or otherwise mixed into the mass. In recent years, approaches to smoke management in atria have been introduced into codes and engineering guides (BOCA; UBC 1993; NFPA 92B 1991; Klote and Milke 1992; Hansel and Morgan 1994). While these basic approaches differ in many respects, they all have the zone fire model concept as a common foundation and consist of a collection of algebraic equations intended for design calculation. For simplicity, discussion of the basic approaches is limited to those of NFPA 92B. However, much of this applies to the other approaches as well. The paper explains the physical concepts behind NFPA 92B including system limitations. The conservative nature of this approach is investigated, and the unique design challenge of atrium smoke detection is discussed. The application of zone computer fire models to atrium design is addressed. This paper also presents a computer program entitled Atria Smoke Management Engineering Tools (ASMET) that consists of a set of equations that may be of help for conventional applications. Appendices C and D describe ASMET including brief user instructions.