FeS引发储油罐着火温度动态变化曲线的研究

Study on Dynamic Ignition Temperature Curve of Oil Storage Tank Induced by Ferrous Sulfide

储油罐着火事故被推测是由硫腐蚀产生的FeS氧化引起的。笔者阐述了储罐中FeS形成的原因 ,并采用自然发火绝热测试系统对FeS自然氧化进行 1 9h的跟踪实验 ,观察FeS绝热氧化过程中温度动态变化特性。实验发现 ,FeS氧化由诱导氧化期、中速氧化期和加速氧化期 3个阶段组成。诱导氧化期是积蓄能量 ,激发FeS活性的过程 ,试样温度基本未发生变化 ;中速氧化期是FeS试样表面的分子活性被激发 ,与FeS试样表面吸附的氧气发生氧化反应的过程 ,温度增加较慢 ;加速氧化期是FeS分子内部的活性被激活并进行氧化反应的过程 ,温度迅速升高。结果证明 :随着反应的进行 ,温度随反应时间变化的幅度越来越大 ,氧化反应的反应热不能及时散开而急剧地积累 ,温度急剧地升高 ,将引起油品自燃。此外 ,通过X衍射图和氧化升温曲线证明 ,水是影响FeS氧化的重要因素。

By inference, the ignition of the oil storage tank is caused by the oxidation of ferrous sulfide produced from the sulfur corrosion. The formation process of ferrous sulfide in oil storage tank is described. The spontaneous oxidation process of ferrous sulfide is tracked for 19 hours by spontaneous ignition heat isolation test system to observe the variation characteristics of dynamic temperature changes during the oxidation process of ferrous sulfur under isolated heat. The experiment show that the oxidation process of ferrous sulfide may proceed in three stages, i.e. motivation oxidation, medium speed oxidation and accelerative oxidation stages. In the motivation oxidation stage, the energy is accumulated, and the ferrous sulfide is activated. The temperature of the sample basically is not changed. In the medium speed oxidation stage, the molecules on the surface of ferrous sulfide sample are activated, and the oxygen adsorbed on the surface of ferrous sulfide sample motivates the oxidation process. The sample temperature elevates rather slowly. In the accelerative oxidation stage, the interior ferrous sulfide molecules are activated and proceed the oxidation process. The temperature rises rapidly. The results show that as the reaction proceeds, the variation extent of temperature varies much bigger. The reaction heat of oxidation could not disperse in time, instead, it is accumulated and the temperature rises rapidly causing the spontaneous combustion of the oil. In addition, the X ray diffraction graph and temperature curve prove that water plays an important role in the oxidation of ferrous sulfide.