A method for approximation of maximum heat release rate capacity of an emergency ventilation system using transient CFD simulations - a performance-based design analysis tool

摘要

Performance-based design is gaining acceptance in demonstrating compliance with fire life safety requirements of enclosed structures. Usually, steady state Computational Fluid Dynamics (CFD) simulations are used as a tool in the performance-based design analysis process to examine the suitability of a given Emergency Ventilation System (EVS) to comply with the applicable safety standards. The results of the steady state CFD simulation can only provide a pass/fail prediction of a particular EVS. Often the parties responsible for the design, construction, and operation of an enclosed structure (such as a transit subway station) are interested in knowing the capacity or the limiting fire size for an existing (or planned) EVS. Transient CFD analysis in conjunction with a growing fire was used in a systematic method for predicting the limiting fire size of a given EVS configuration. The method was applied to a sample case involving a subway station. The results of the sample case are used to demonstrate the procedures of the prediction method. This paper discusses the potential application and limitations of the prediction method toward limiting fire size.