浅谈天然气场站防雷电

Lighting Protection of Gas Terminal Station

防雷电是确保天然气场站安全的一项重要措施。介绍了雷电对天然气场站和输气管道的危害及主要表现,指出应构建一个完善的防雷工程:利用外部防雷装置(接闪器、引下线和接地装置)承接50%以上的雷电流并将其泄入大地;采用等电位连结、屏蔽、防闪络技术和装置,阻塞雷电波沿金属导线和空间电磁场入侵的途径;利用某些元件的非线性特性,组成电涌保护器(SPD)并将其连结在配电和信号线路中,将累计产生的过电压和过电流通过SPD泄入大地。以仪表控制系统为例,指出治理侵入仪表控制系统雷电危害的主要措施包括接闪、分流、均压、接地和屏蔽等。

Lighting-proof is important to ensure a safety of gas terminal station. This paper illustrates lighting harm to both station and gas-transmission pipelines. In addition, it is considered that a perfect lighting-proof project should involve (flash-grounding device, down lead and grounding device)can many measures as follows,(1)external lighting-proof devices bear over 50 percent of lighting current and drain it out;(2)some technologies and devices of isopotential connection, screening and flashover are used to obstruct an invasion of lighting wave along metal conductor line and spatial electromagnetic field;(3)to use nonlinear characteristics of some components to constitute a surge protective device(SPD), and then to connect SPD to distribution and signal lines, at last to drain all accumulatively created overvoltage and overcurrent out through SPD. In this paper, taking an instrumental controlling system as an example, it is pointed out that the main measure to control lighting harm invading this system includes flash grounding, diffluence, voltage sharing, grounding and screening.