Numerical Simulation Study On The Smoke Control System In Atrium Building

Compared with the traditional architecture, the most prominent feature in a atrium is that it has one or more large cap space which continuous in the vertical direction through several floor. Once fire happened in atrium, smoke will spread rapidly in the atrium and extended to the other connected floor. GB50016-2006 by using the unit volume index to calculated the amount of exhaust smoke volume in a atrium,DGJ08-88-2006 deem the exhaust smoke volume equal to the amount of gas produced.However, when the fire broke in an atrium, the distribution and variation of smoke and harmful factors is not clear, the use of these two methods to determine the amount of exhaust smoke volume that can meet the evacuation requirement is questionable.In this paper, the study of smoke control system relies mainly on large-eddy simulation(LES) using FDS numerical prediction. To make simulation results more credible, combined with the experimental data in the literature, this paper respectively, study the fulence grid density, Cs and Prt on the simulation predictions of the temperature field and velocity field, and optimized the using range D*/σx, indicated that the temperature field, velocity field dependence on Cs and Prt, building up the foundation of the studying on the design of smoke control systemThe existing design codes did not have specific design requirements on the smoke control system, not have an evaluation criteria of smoke control system design. To solve this problem, from the perspective of staff evacuation, the paper put forward a safe evaluation criteria, including flue gas temperature, CO volume concentration, CO2 volume concentration, O2 concentration and visibility, which provides a specific target and evaluation criteria for the design of smoke control system. In the absence of smoke control sytstem,investigated through fire area, fire heat release rate and fire location of the three factors, the natural development of fire smoke, evacuation of each criterion were studied. Combination of safe criterion, by judging the minimum time beyond the safety criterion, the optimum start time was given.Learn from the DGJ08-88-2006, proposed the method to estimating the exhaust smoke volume based on the products of combustion.In determining the exhaust smoke volume and the start time of smoke control, the two factor's influence on exhaust system were studied, pointing the inapplicability of calculation by useding GB50016-2006 and DGJ08-88-2006. Research out of the the best exhaust volume and optimum start time of the example, as well as the significance of timely and open exhaust system.Finally, based on Performance-based fire protection design,the paper advanced a new method for somke control system design. The method has good feasibility, HVAC engineers could completed independence, as compare to traditional design methods, there is greater security and flexibility.The research results and ideas can provide a reference to the smoke control design. the paper build a complete Performance-based fire protection design for atrium building,the method incloud:mesh density, the key parameters required for the setting, safe evacuation criteria, Smoke filled law, exhaust smoke volume and optimum start time. The method can make the the design of smoke control system for atrium more scientific and more security.