大空間排煙口設置參數對排煙性能影響之研究

大空間建築是近年最受歡迎的建築之一，舉凡台北101、京華城、中正機場等等，讓使用者有明亮、舒適的感覺，常於其中設計具備中庭或挑高大空間。而於這類地方，又常是人群眾多聚集之地，故其火災緊急時之煙控性能要求非常重要。因為挑空中庭空間的型態，在火災發生時，會形成所謂的「煙囪效應」，此種效應會造成挑空中庭空間的煙流迅速的由下往上竄升，形成整棟建築物陷於火煙急速擴大及擴散的危險當中。而目前我國現行之典型條例式法規，並不能適用於大空間建築，一般可行之做法皆需以電腦模擬及現場全尺寸實測結果作防煙性能式分析。近年來由於電腦科技進步，個人電腦已經可以負荷大多數之工程分析，本研究以近年被使用作為火災模擬分析之美國NIST所發展之FDS(Fire Dynamics Simulator)火災模擬軟體作為分析工具。本研究考慮大空間中庭中發生之火災針對大空間排煙口參數進行模擬分析，如設置位置、風速與風量等對於大空間排煙之影響，並使用排煙指數分析中庭拉穿效應(plug-holing)對排煙效率的影響大小，並設溫度偵測樹測量來觀察火災煙流的分佈狀況，以期能找到最佳之設置參數與建議，作為日後性能式設計與大空間火災實驗規劃之用。

關鍵字

中庭；拉穿效應；排煙指數

並列摘要

Buildings with atria or large spaces are becoming popular lately, such as Taipei 101 trade center, shopping malls, airport lobbies. Large spaces provide comfort and bright feeling. However the smoke control requirements and performance are important as they are often heavily occupied. Stack effects are prominent in an atrium fire; smoke plume will rise and may spread quickly to other parts of the building and cause danger to people inside the building. The present fire safety code does not provide for an atrium fire. Therefore, computer analysis and field experiments are often need to evaluate the fire safety design on performance basis. This study uses computer modeling method to analyze parameters that will affect the smoke control performance for an atrium. This study uses the computer program FDS(Fire Dynamics Simulator) as developed by NIST(National Institute of Standards and Technology). Parameters such as locations of the smoke exhaust, exhaust velocity and exhaust volume, etc are evaluated in this study. Plugholing effects are studied. A new performance index the smoke exhaust index is used for evaluation of the plugholing effects on the effective smoke exhaust volume. Measurement trees were setup in the computer model for observation of smoke distribution in a fire. It is found that improper smoke exhaust outlet location has great effects on smoke exhaust. Also, effective smoke exhaust volume is not necessarily proportional to the mechanical exhaust volume. Performance curves for various cases are provided for reference in actual design.

並列關鍵字

Atrium ； plug-holing ； smoke exhaust index

參考文獻

[2] McGrattan, K.B., Baum, H.R., Rehm,R.G., “Large Eddy simulations of smoke Movement,” Fire Safety Journal, 30 pp.161-178. , 1998.

[6] Zhang, W., Andrew Hamer, Michael Klassen, Douglas Carpenter, Richard Roby, “Turbulence statistics in a Fire Room Model by Large Eddy Simulation,” Fire Safety Journal 37 pp.721-752. , 2002.

[7] Wang, H.Y., Coutin, M., Most, J.M., “Large-eddy simulation of Buoyancy-driven Fire Propagation behind a Pyrolysis Zone along a Vertical Wall”, Fire Safety Journal 37 pp.259-285. , 2000.

[10] NFPA 92B, Guide for Smoke Management Systems in Malls, Atria, and Large Areas, 2000 Edition.

[11] The BOCA National Building Code, 1987.

國際替代計量

大空間排煙口設置參數對排煙性能影響之研究

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