歌劇院等大型空間避難性能化設計探討

Performance-Based Design Analysis of Evacuaion in Opera and Other Large Spaces.

吳冠廷(Guan-Ting Wu)

指導教授 ： 何三平

長榮大學/健康科學學院/職業安全與衛生學系(所)/碩士(2011年)

摘要

本研究以歌劇院等具備大型挑高空間為例，採用CFD-model電腦軟體進行火場模擬實驗，利用美國NIST(National Institute of Standards and Technology)之防火實驗室(BFRL)所發展之FDS(Fire Dynamics Simulator)火災模擬軟體，由實際歌劇院之內部設計藍圖來建構模型並進行模擬，針對其十二個不同高度且不同形狀與用途之挑高空間，配合其各空間之條件，包括火源大小、位置、機械排煙口大小、機械排煙量、自然排煙窗、補氣口位置等，探討其煙層之高度與下降到1.8m之時間，以及計算各空間之逃生避難時間，並且改變其排煙口尺寸、面積、數量，最後進行各時間之比較，找到最佳設置參數與建議，以作為日後性能化設計之參考。模擬結果顯示，在劇院等特殊挑高空間中，利用其蓄煙之能力，煙層下降至最高的4F最快須315秒，而4F人員於119秒皆已逃生完畢。而在一般空間中，利用蓄煙以及機械排煙或複合式排煙，其煙層下降時間皆能在人員逃生避難完畢後到達1.8m之危害指標，表示人員皆能安全避難。而在變更機械排煙口方面，當排煙量不變時，排煙口面積尺寸縮小，導致其排煙之風速變大，而產生亂流之現象，並導致部分排煙效果較差，且當排煙口之距離減少，排煙口間之抽風效率亦相對降低。其排煙效果與排煙口之面積、數量、距離有關。而格點切割方面，當空間以2l×3m×5n之方式進行模擬時，其電腦計算時間明顯較未以2l×3m×5n之方式模擬之時間來的長，並未遵循使用手冊之結果，其可能之影響因素為MESH切割數量與串聯之電腦數量，以及空間內部設置之複雜度，皆可能影響模擬之時間長短。而在FDS避難逃生模擬方面，當建築物之安全門寬度小於1.5m時，以FDS模擬之逃生避難時間較長，因其模擬逃生時，可能於安全門口產生阻塞擁擠之情況，故建議以FDS模擬是較為保守之評估方式；而當安全門之寬度大於1.5m時，建議以內政部建築研究所之驗證公式是較為保守之評估方式。

關鍵字

CFD-model ； FDS(Fire Dynamics Simulator) ； 煙控系統設計 ； 機械排煙 ； 自然排煙

並列摘要

This research takes places with high raised surfaces such as opera houses for example, using the FDS (Fire Dynamics Simulator) fire scenario simulating program developed by the USA's NIST's (National Institute of Standards and Technology) fire prevention laboratory (BFRL). Taking into account the actual blueprint of the interior of the opera house to build a replica and begin simulating, focusing on twelve different heights, outlines, and usages of the high raised surfaces, while putting each of their features into account, including the fire level, location, the size of the mechanical exhaust port, the amount of smoke released, natural ventilation windows, the place of air supply etc, discussing the height of the smoke layer and the time that it takes for it to descend to 1.8 meters, whilst calculating the time needed for escape for each space, also altering the size, area and number of the exhaust port, finally comparing the numbers attained for different times, and picking out the best parameter setting and recommendations, so that they can be taken into suggestion for performance designs in the future. Simulation results show that, in unique high raised surfaces such as opera houses, using its ability to gather smoke, it takes at least 315 seconds for it to descend to the highest story on the 4F, and that the people on the 4F had already evacuated in 119 seconds. In normal spaces, using smoke gathering and mechanical or compound smoke releasing, the time needed for the smoke to descend to the danger line of 1.8 meters is consistently after the time required for people to evacuate. In the section of changing the aspects of the smoke exhaust, when the amount of smoke is fixed, and the size of the exhaust port is diminished, resulting in the increase of wind speed that the smoke is released, inducing turbulence, reducing the effectiveness partially of which the smoke is released, and when the exhaust ports are closer in distance, there is also a reduction in the efficiency of which the smoke is ventilated. The performance is associated with the size, number, and distance of the exhaust ports. For the grid cutting portion, when the space is simulated not under 2l×3m×5n, the computer's calculations for the time needed was visably shorter than the time used when simulating under 2l×3m×5n, and didn't the results in the user manual. Possible factors are MESH cutting quantity, the number of computers in a series and the complexity of the interior of the space can all affect the time needed for simulation. For the part of the FDS escape simulation, when the width of the emergency exits of the building is less than 1.5 meters, the time required for evacuation is longer, because during the simulation, it is possible that there could be obstacles blocking the path, so the use of FDS is more recommended. When the width of the emergency exits is wider than 1.5 meters, it is better to use authentication formula provided by the Ministry of the Interior.

並列關鍵字

CFD-model ； FDS(Fire Dynamics Simulator) ； high raised surfaces ； smoke control

參考文獻

【6】周士凱，排煙口開口特性對排煙效應影響之分析與探討，長榮大學職業安全與衛生研究所碩士論文，2009

【5】Klote JH, Mike JA. “Design of smoke management systems”, Atlanta Ashrae, Inc（1992）.

【42】陳清峰，特殊空間煙控系統之性能化評估，長榮大學職業安全與衛生研究所碩士論文，2006

【11】Fire Engineering Design Guide

【17】Wenting Dinga,“Smoke control based on a solar-assisted natural ventilation system” , Fire Safety Journal, Vol.39, p.775- 782 （2004）.