球形瓦斯儲槽之熱效應模式與相關法規研究

Thermal Response Model and Related Regulation of Spherical LPG Storage Tanks

液化石油氣（LPG）是一種非常重要的燃料外也是很多石化產品的進料；然而，液化石油氣亦伴隨許多重大火災與爆炸，其中一種災害為「液體沸騰氣體膨脹爆炸」（BLEVE），係指液體貯存溫度大於大氣壓沸點溫度時，突然從封閉容器中釋放出來的一種物理現象。由於壓力突然釋放而使部份的液體氣化產生具爆炸性的蒸氣雲。大部分的BLEVE 與可燃性液體有關，且大部分的BLEVE 一旦被周圍的火源點燃常形成火球。此研究之目的主要在建立液化石油氣球形儲槽為火焰吞沒之熱效應模式，而其控制對策，包括撒水冷卻與兩儲槽間之安全距離也藉此模式提出分析，有關BLEVE 現象引發之熱輻射風險分析一併提出。此研究發展之模式尚可應用到其它高壓氣體如乙烯、液氨等儲槽受火災危害時之安全評估。此外，我們亦探討以API 法規為基礎，提供國內液化石油氣相關法規之修正參考。

LPG is a very important fuel and chemical feed stock as well; however, it has been involved in many major fires and explosions. One of these incidents is boiling-liquid, expanding-vapor explosion (BLEVE). It is a phenomenon that results from the sudden release from confinement of a liquid at a temperature above its atmospheric-pressure boiling point. The sudden decrease in pressure results in the explosive vaporization of a fraction of the liquid and a cloud of vapor and mist with the accompanying blast effects. Most BLEVEs involve flammable liquids, and most BLEVE releases are ignited by surrounding fire and result in a fireball. The objective of this study is to develop computer model in order to determine the thermal response of LPG tanks involved in fire engulfment accidents. The assessment of protection measures, including safety spacing between tanks, water spray cooling, and prediction of tank failure, were analyzed. The risk associated with the thermal radiation due to BLEVE of the LPG tank was analyzed. The model used in this work can be applied to safety/reliability assessment of other pressure-liquefied-gas (PLG) tanks, such as ethylene, ammonia, and so forth. In addition, we studied API’s regulation for purpose of suggestion in modifying the current domestic LPG-related regulations.