FDS與ALOHA軟體評估石化工廠火災之分析

The Comparison of Fire Analysis between FDS and ALOHA Programs for Petrochemical Plants

目前國內工業界及消防界大多採用ALOHA模擬軟體進行初步緊急應變範圍之評估。本研究利用實場模式FDS（Fire Dynamics Simulator）模擬軟體與簡易擴散模式ALOHA（Areal Locations ofHazardous Atmospheres）模擬軟體這兩套模擬軟體進行比較及分析。並針對石化工廠發生火災時，其設定相同條件下，對於火災模擬結果之差異性。本研究結果發現，ALOHA軟體評估之輻射熱影響範圍顯得過於粗糙，其結果也明顯高估實際狀況之後果，將可能導致搶救人員於執行任務時而判斷錯誤。而FDS軟體較能準確地預估其輻射熱影響。且當有外在環境之影響時，如風速、障礙物等條件下，FDS之模擬評估顯得重要許多，其效果也優於ALOHA模擬軟體。此外，FDS這套模擬軟體以法定撒水密度模擬時，確實能有效地降低輻射熱；且相同的儲槽下，不同的內容物之燃燒，確實會產生非常明顯不同輻射熱之影響。綜觀以上，障礙物及水幕等減少輻射熱等效應評估，均是ALHOA軟體所無法模擬的。建議對於評估工業火災時，應明確考慮使用FDS模擬軟體來執行，以擬定有效之緊急應變計畫，能快速有效地控制火勢，亦能降低人員傷亡及莫大的財產損失。

The ALOHA(Areal Locations of Hazardous Atmospheres) model is always used for emergencyresponse evaluation in industries and firefighting area recently. In this study, FDS(Fire DynamicsSimulator) and ALOHA programs are used to simulate fire scenarios in petrochemical plants to analyzeand compare the differences between them. FDS can simulate the fire scenarios with water spraysystem since the radiation effects can be significantly affected by water spray and burning materials inthe same tank. The ALOHA model, however, cannot simulate the effects of obstacle and water spraysystem. Therefore, FDS is recommended to use in the radiation simulation in the industrial fires. Thesimulation results can also be used to modify the emergency plan to control fires earlier and preventloss of properties and human.