油罐着火扬沸前水层温度响应的分析

AN ANALYSIS ON WATER－LAYER TEMPERATURE RESPONSE OF ON－FIRE OIL TANKS DURING BOILOVER PREMONITION PERIOD

扬沸是油罐火灾中特有的灾害性燃烧现象。根据对油罐着火扬沸发生前传热机理的分析，给出了简化数学模型。利用该模型分析了水层温度响应过程，提出了着火初始阶段时间长度的概念，并给出其解析表达式，为通过实验整理经验关系式提供了明确形式。通过数值计算，还对燃烧速度、油罐表面冷却等因素进行了分析。结果表明，燃烧速度对扬沸发生时间影响最大，而油罐表面冷却并不能有效地延迟扬沸的发生。

An analysis is made on the water－layer temperature response of on－fire oil tanks during their initial period, based on a simplified mathematical model established in this paper. Both the analytical and the numerical results are presented for various conditions under which the fires take place. The results show that there exists a boilover premonition period during which the water－layer temperature becomes relatively slow. Based on this findins the boilver premonition period is defined and its analytical expression is provided which may be used as a starting point for handling the experimental data. It is also shown that the combustion rate is the most important parameter in determining the boilver premonition period, while the surface cooling of the on－fire oil tanks has little effects for retarding their boilovers.