The physical and chemical causes of oxygen cylinders explosion were analyzed and summarized. Explosion of oxygen cylinder containing oil occurred in 2009 in Nanjing and several domestic similar accidents were comprehensively analyzed. Filling oil into oxygen cylinder was due to misoperation, and oxygen carbon tetrachloride was not used to remove oil in accordance with the relevant national standards before filling. Violent oxidation exothermic reaction occurred when oil was exposed to pure high pressure oxygen. The instantaneous releasing of heat produced high temperature and high pressure in gas cylinder, which exceeded its limits and caused burst. Generally, cylinder explosions caused by oil, not as violent as mixed combustible gas cylinder explosion, were not crushing explosion. Temperature would increase in normal filling oxygen, and detailed change of oxygen temperature in the filling process was calculated by thermodynamics of variable quality. The internal oxygen temperature was 53℃ when it was charged to maximum pressure 14. 7MPa and the outer wall temperature was below 53℃ because of the heat capacity of cylinder. The unusual circumstances were controlled and prevented timely if oxygenation temperature was provided as a reference. Pressure gauge shows that cylinder explosion occurred while oxygen cylinder is charged to 12. 0MPa; the minimum explosion pressure of oxygen cylinder is 37. 6MPa; oxygen pressure increases from 12. 0MPa to 37.6MPa by oil oxidation combustion. Moreover, inverse calculation shows that minimum oil amount leading to burst of cylinder is between 66.4g and 79. 6g; minimum oil amount leading to burst of cylinder decreases as the increasing of filling pressure%分析总结了氧气钢瓶物理爆炸和化学爆炸的原因.针对2009年某市发生的一起氧气瓶内含油脂爆炸事故,系统分析了国内曾经发生的几次因油脂导致气瓶爆炸事故.油脂进入到氧气瓶内大都是由于误操作.油脂与高压纯氧接触会发生剧烈的自燃氧化放热,使瓶内的氧气迅速升温升压,超出气瓶承压极限导致爆炸破裂.分析比较发现由油脂导致的气瓶爆炸,其破坏程度不如混入可燃气体导致的气瓶爆炸剧烈,一般不是粉碎性爆炸.在正常的充氧过程中,氧气瓶温度会升高,采用变质量热力学中的方法,计算说明气瓶在充装过程中氧气温度的具体变化.充氧温度计算为充氧工作人员提供参考,如发现异常情况,可以及时地控制和预防.由现场压力表可知氧气瓶在充装至12MPa时发生爆炸,而氧气瓶最小爆炸压力为37.6MPa,油脂燃烧放热,计算可知致使钢瓶爆炸破裂所需要的最小油脂量,为66.4-79.6g.不同的充装压力下发生爆炸,所需要的最小油脂量不同,充装压力越高,爆炸所需要的最小油脂最越少.
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