复杂地形条件下气体泄漏扩散规律仿真与试验

针对复杂地形气体泄漏扩散问题,基于计算流体动力学方法,建立复杂地形气体泄漏扩散数值仿真方案,确定地面气体分布特点、监测点气体质量浓度随时间变化规律、地形及环境风向、风速等对气体扩散的影响作用。以SF6为示踪气体,设计并在川东北某山区集气站实施气体释放试验,以有色烟雾发生器为工具确定采样点布置,采用电子时控大气采样器和气相色谱-电子捕获检测法进行样品采集和分析,得到不同采样点、不同时间段内示踪气体浓度值。SF6释放试验结果表明,试验方案设计合理、可靠、具有广泛的适用性,能够有效降低采样点数量,提高采样数据的有效性,实现对试验数据的采集和分析。试验与仿真计算数据的一致性验证了建立的数值模型处理复杂地形气体泄漏扩散过程的有效性。

Simulation and experiment of gas leakage and dispersion in complex topography

Aiming at the problem of gas leakage and dispersion in complex terrain,a CFD-based gas leakage and dispersion numerical simulation model in complex terrain was proposed.The gas distribution on the ground and variation of tracer gas concentration of monitoring points with time were estimated.The effects of terrain,wind direction and wind speed on gas dispersion were obtained.Taking SF6 as tracer gas,a gas release experiment was carried out in mountain gas gathering station.The colored smoke generator was taken as a tool to determine the arrangement of the sampling points.The electronic time-controlled air sampler and gas chromatography-electron capture detection method were used for sample collection and sample analysis,respectively,which could measure the concentration of tracer gas in sampling points at different time.The results of SF6 release experiment show that the experimental program is reasonable and has wide applicability.The model can effectively reduce the number of sampling points,improve the effectiveness of sampling data,and implement the test data acquisition and analysis.The contrast between simulation results and experiment results illustrates the validity of numerical model in handling gas leakage and dispersion in complex mountainous terrain.