鐵捲門於防火區劃中受火熱變形之研究

Abstract

本論文運用火災模擬軟體FDS對火場進行熱流分析，並將捲門之溫度分佈與壓力分佈作為ANSYS分析之負載，考慮材料性質隨溫度之變化與拘束條件等特性分析捲門變形狀況以及熱應力分佈，並再回饋於FDS進一步對防火捲門構成之防火區劃進行分析與討論。 案例分析前，本研究先藉由大型加熱爐火場試驗進行驗證。模擬結果顯示，模擬之變形趨勢與實驗相近，且因考量材料性質之參數，模擬與實驗之誤差由30%降低至14%。 案例的討論對象則為區劃電扶梯間之防火捲門，於一地下場站內進行火災模擬。設定捲門完全關閉及下降至距地面2公尺處兩種情境。由模擬結果顯示，捲門完全關閉的情境中，其變形呈波浪狀，最大變形量為202mm，熱應力最大值則為2.3 Gpa並集中於門片底端。經文獻比較，其變形較符合實際民宅火災與實驗之變形趨勢，而與前人模擬結果，捲門均朝火場方向變形相異，本研究推測因考量壓力分佈與捲門本身之推擠導致。此外，當捲門下降之距地面兩公尺處之情境，因壓力之推擠朝非曝火面凹陷，最大變形量為207mm，熱應力最大值則為1.2 Gpa並集中於捲門兩側。 本研究經由文獻比較，整理出各參數對模擬捲門變形之影響：（1）溫度分佈為捲門膨脹變形之主因；（2）壓力分佈與捲門結構影響捲門變形之方向；（3）材料性質影響捲門變形量之大小；（4）拘束條件影響熱應力之分佈。

This study carries out the fire resistance evaluations of the fire shutters used in building by FDS (Fire Dynamics Simulator) and ANSYS software. We use the results of temperature and pressure distribution on the shutters which is simulated by FDS to be the load of ANSYS. Besides, we also consider the material properties that vary from temperature and boundary conditions to analyze the deformation and the thermal stress distribution of the shutters.

Before simulations of case analysis, we verify the cooperation between two commercial codes, FDS and ANSYS, by large boiler fire test. Simulation results show that simulate and experimental deformation are similar. The error between simulate and experimental deformation decrease from 30% to 14% for considering the parameters of material property.

Shutters used in escalator room are the target of this study. The study uses FDS to simulate a fire accident in a substructure that are specified into two scenarios. In the first scenario, the shutters close completely. In the second, the shutters descend down to a position, where 2 meter-height above the floor. The results show that the deformation of the shutters forms into wavy while the shutters close completely, which the maximum deformation is 202mm and the maximum thermal stress is 2.3Gpa. Compare with other experimental researches, it is more practical than the one who neglects the pressure distribution. In addition, the maximum deformation is 207mm and the maximum thermal stress is 1.2Gpa when the shutters close incompletely.

Finally, the study obtains the relationship between parameters and deformation of shutters: (1) the main reason of expansion of shutters is the temperature distribution; (2) pressure distribution and the structure of shutter affect the deformation direction of shutter; (3) material properties affect the size of shutter deformation; (4) boundary conditions affect the thermal stress distribution of the shutters.