Abstract: Combustible gas within the limits of the explosive in sealed space of floating roof tank，could lead to explosion by lighting. In order to study the feasible technology about lighting of floating roof tank seal, concentration of oxygen remain below 8% was put forward through adding nitrogen into the sealed space, thus reduced the risk of explosion. By analyzing the change of oxygen concentration after injecting nitrogen into the sealed space, the relationship between the change of oxygen concentration and nitrogen injection was set up. At the same time, through the experiment when the sealed maintains the micro positive pressure, a formula was established about the nitrogen flow and micro positive pressure, which could obtain the amount of nitrogen directly under different wind speed and lightning time to complete inertly. The method provided a reference to blanketing technology applications in seals of floating roof tanks.

Key words: Floating roof tank , Lightning protection , Nitrogen sealed ,  Modeling , Micro positive pressure

摘要： 浮顶油罐一二次密封圈内处于爆炸极限范围内的油气在雷击作用下可导致爆炸事故,为研究切实可
行的浮顶油罐密封圈防爆技术,提出了在雷击过程中往密封圈内注入氮气从而降低氧气的体积分数,使其一直保持
在8%以下,从而降低爆炸危险性的方法。通过对氮气注入密封圈后氧气体积分数变化的影响进行分析,建立了氧
气体积分数的变化与注入氮气体积的关系。同时,通过密封圈维持微正压状态的实验,建立了氮气流量与微正压的
关系式,从而可直接得出在不同风速和雷击时间下完成惰化所需要的氮气总体积。该方法可为氮封技术在浮顶油
罐密封圈的应用提供借鉴。

关键词: 浮顶油罐 , 防雷 , 氮封 , 建模 , 微正压