论文部分内容阅读
为了完善大型浮顶油罐的防雷技术,对浮顶油罐遭雷击过程进行了分析,并对目前标准规定的浮顶油罐防雷措施进行了实验。实验表明导电片的主要作用是快速释放雷电流,但导电片的存在也有其反效应,即当浮顶油罐遭受雷击时,导电片与罐壁之间会产生电火花。因此,提出了取消浮顶边缘二次密封上方的导电片,采用了增加可伸缩的接地装置(SGD)弥补导电片取消后雷电流释放通道的不足,并以105m3实际油罐为例,均匀布置安装不同个数的SGD,利用经验公式对其遭受直击雷时的暂态电压降进行计算。计算结果表明,对200 kA雷电流,采用不同截面宽度的SGD时,均匀分布的连接浮顶与罐壁的14~20个SGD能够保证浮顶油罐安全泄放雷电流。
In order to improve the lightning protection technology of large floating roof tanks, the process of lightning strikes of floating roof tanks was analyzed and the lightning protection measures of the floating roof tanks prescribed by the current standards were also tested. Experiments show that the main role of the conductive sheet is to quickly release the lightning current, but the presence of conductive sheet also has its opposite effect, that is, when the floating roof tank struck by lightning, the conductive sheet and the tank wall will produce sparks. Therefore, it is proposed to eliminate the conductive sheet above the secondary seal of the floating roof edge and to make up for the deficiencies of the lightning current release passage after the retractable grounding device (SGD) is added. Taking 105m3 actual oil tank as an example, Install a different number of SGDs and use empirical formulas to calculate the transient voltage drop at the time of their direct lightning strike. The calculation results show that for the 200 kA lightning current, the SGD of 14 ~ 20 SGD which connects the floating roof and the tank wall evenly can guarantee the safe discharge of lightning current of the floating roof tank.