新型外浮顶石油储罐导电片的设计研究

发布时间：2018-05-13 14:55

本文选题：感应雷 + 直击雷　；参考：《大连理工大学》2015年硕士论文

【摘要】：目前石化行业当中,一种用于储存油品的主要油罐结构是外浮顶油罐,外浮顶油罐在雷雨天气有着遭受雷击而发生着火爆炸事故的危险。对于预防雷电对外浮顶油罐的破坏目前已经有很多方法,同样,也有很多设施、设备用于疏散落在外浮顶油罐上的杂散雷电流,但都存在着不同程度的问题。本论文中使用CDL-100kA/200kJ-10/350us-Crowba冲击电流发生器和CDL-100kA/76.8kJ-8/20μs冲击电流装置分别模拟直击雷雷电流波形和感应雷雷电流波形,并建立了1：1大型外浮顶油罐浮盘模型和2m直径外浮顶油罐模型两种模型,使用不同雷电流波形和不同模型间的相互组合,比较全面的分析了现有形式的上装式导电片的几方面主要性能,如张力、最大电流通流量、最小闪络电流值等,并在此基础上,提出了对现有形式的上装式导电片进行改造,设计出一种新型导电片,通过相同实验,测试了新型导电片的主要性能,实验发现,新型导电片的几项主要性能都优于现有形式的上装式导电片。通过实验分析,在10/350 u S直击雷波形和8/20 μ S感应雷波形下,在1：1模型和2m直径金属储罐模型的实验中,现有形式的上装式导电片的最小闪络电流值和最大电流通流量分别低于相同实验条件下的新型导电片。当雷电流波形相同时,同种导电片在两种不同模型中最小闪络电流值基本一致。当在同一模型中实验时,在10/350 μ S波形下导电片发生闪络的最小电流值和导电片出现烧蚀的最小电流值明显小于在8/20 μ S波形下试验的最小电流值,由此可见直击雷的10/350 u S波形能量比感应雷的8/20 u S波形能量大。现有形式的上装式导电片的张力一般在5N左右,并且在油罐运行过程当中,张力会随着外界因素逐渐减弱,而新型导电片的张力可以调节,当张力调节至9N时,新型导电片与罐壁接触电阻值小于0.03 Ω,符合标准要求。考虑到安装和运行时可能存在的误差,新型导电片在10N的张力下,发生大火闪络的最小电流值设定为10kA。10万m3外浮顶油罐,周长为251m,按2.5m间距布设1个新型导电片,将布设100个。如果雷电流为100kA,则每个新型导电片通过的雷电流1kA,不会打火。针对新型导电片与软铜复绞线结合疏散雷电流的综合实验,即结合现场实际情况,可以发现,在相同的实验条件下导线对于直击雷的分流能力比对于感应雷的分流能力弱,但分流作用不可忽视,实验也说明了现场浮盘只有两根软铜复绞线分流能力不够,需要通过导电片来增强对雷电流的疏散能力。
[Abstract]:At present, one of the main oil tanks used to store oil in petrochemical industry is the outer floating roof oil tank. The outer floating roof oil tank is in danger of fire and explosion caused by lightning strike in the thunderstorm weather. There are many methods to prevent the damage of external floating roof tank by lightning. Similarly, there are many facilities, which are used to evacuate stray lightning current from floating roof tank, but there are some problems to some extent. In this paper, CDL-100kA/200kJ-10/350us-Crowba impulse current generator and CDL-100kA/76.8kJ-8/20 渭 s impulse current device are used to simulate the lightning current waveform and inductive lightning current waveform respectively, and two models are established: the floating disk model of 1:1 external floating roof oil tank and the 2m diameter outer floating roof oil tank model. By using the combination of different lightning current waveforms and different models, the main properties of the existing top conductive sheet, such as tension, maximum current flux, minimum flashover current, etc., are analyzed comprehensively. A new type of conductive sheet is designed and the main properties of the new type conductive sheet are tested through the same experiment. Several main properties of the new conductive sheet are superior to the existing form of the upper conductive sheet. Through experimental analysis, in the experiments of 1:1 model and 2m diameter metal storage tank model, under 10 / 350u S direct strike wave and 8 / 20 渭 S induced lightning waveform, The minimum flashover current and the maximum current flux of the current type conductive sheet are lower than those of the new conductive sheet under the same experimental conditions. When the lightning current waveform is the same, the minimum flashover current value of the same conductive sheet is basically the same in two different models. When tested in the same model, the minimum current value of the flashover and the minimum current value of the ablation of the conductive sheet under the 10 / 350 渭 S waveform are obviously lower than the minimum current value tested under the 8 / 20 渭 S waveform. It can be seen that the energy of 10 / 350u S waveform of direct strike lightning is higher than that of 8 / 20 u S wave energy of inductive lightning. The tension of the current type of top conductive sheet is generally about 5 N, and during the operation of the oil tank, the tension will gradually decrease with external factors, while the tension of the new type of conductive sheet can be adjusted, when the tension is adjusted to 9 N, The contact resistance between the new conductive sheet and the tank wall is less than 0.03 惟, which meets the standard requirements. Considering the possible errors in installation and operation, the minimum current value of fire flashover is set as 10kA.10 10000 m ~ 3 outer floating roof oil tank with a circumference of 251 m, and a new type of conductive sheet is arranged at 2.5 m distance, 100 will be installed under the tension of 10 N. If the lightning current is 100 Ka, the lightning current passing through each new conductive sheet is 1 Ka and will not ignite. In view of the comprehensive experiment of the new type conductive sheet and soft copper wire combined with the evacuation lightning current, that is, combining with the actual situation in the field, it can be found that under the same experimental conditions, the diversion ability of the conductor to the direct strike lightning is weaker than that to the inductive lightning. But the shunt effect can not be ignored. The experiment also shows that there are only two soft copper stranded wire in the field floating disk is not enough for shunt ability, so it is necessary to strengthen the evacuation ability of lightning current by conducting sheet.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE972

【参考文献】