超长GIL综合管廊SF6气体泄露模拟研究

GIL导线中充满SF6气体,由于制造、运输、安装与老化等原因,综合管廊GIL舱存在SF6气体事故泄露的可能性,故应设置专门的监测控制系统与排风系统。文章以武汉谭鑫培路地下综合管廊6.3 km超长GIL舱为案例,结合GIL舱排热通风数据与SF6气体扩散特性,确定管廊发生气体泄漏后最不利的泄露位置与工况。通过开源计算流体动力学软件OpenFOAM,建立了SF6气体扩散的三维长节段模型与详细短节段模型,并且给出了数值分析流程。在SF6气体典型事故工况中,以排热通风分析的数据作为边界条件进行了分析,从而得到在既有排热通风系统下GIL舱内SF6气体浓度场的变化趋势。分析结果表明,SF6气体主要由常规排热通风系统排出,但是辅助系统能够很大程度上节省排风时间,相关数据可为通风系统与监测系统的优化设计提供建议。数值模拟方法可为其它类型重气在管廊内泄露扩散模拟提供参考。

Numerical Simulation Analysis of SF6 Gas Leakage in Extra-Long GIL Utility Tunnel

Since the GIL lines are filled with SF6 gas,there is a possibility of leakage accident of SF6 gas in GIL utility tunnel due to manufacturing,transportation,installation and aging,so the corresponding monitoring,control system and effective exhaust system should be established.Based on the 6.3 km super-long GIL cabin of the under⁃ground utility tunnel at Wuhan Tanxinpei road,the most unfavorable leakage position and working condition after gas leakage are determined considering the data of heat-exhaust ventilation and SF6 gas diffusion characteristics.With the open source computational fluid dynamics software OpenFOAM,a 3D long-segment model and a detailed short-segment model for SF6 gas diffusion are set up,and the numerical analysis process is presented.The boundary condition is based on the data extracted from heat-exhaust ventilation analysis,the typical accident conditions of SF6 gas are analyzed and the variation trend of SF6 gas concentration field in GIL cabin is obtained.The analysis re⁃sults show that SF6 gas is mainly discharged by the conventional exhaust ventilation system and the auxiliary system can largely save the exhaust time.The numerical simulation method can provide reference for the simulation of other types of heavy gas leakage and diffusion in the pipe gallery.