埋地与架空输气管道泄漏数值模拟对比分析

针对目前输气管道泄漏研究考虑因素单一、可靠性较差的不足，在参考前人研究成果的基础上，利用计算流体力学仿真软件对5种情况下的天然气泄漏进行了数值模拟。分别得到了天然气泄漏后的速度、浓度、爆炸范围分布情况：①X方向（水平方向）埋地比架空速度稍大，都存在左偏的逆流区；持续泄漏速度比架空瞬间等值线向右偏移，左上和右下方存在两个速度较大区；Y方向（竖直方向）瞬时泄漏在左侧存在逆流区，持续泄漏等值线呈近椭圆分布，不存在逆流区；埋地管道泄漏0速度线向左偏移；增大孔隙度时，速度等值线左偏移。②气体浓度瞬时架空分布不规则，瞬时埋地呈圆形区域且在泄漏口有小范围高浓度区；持续泄漏高浓度区向右下偏移；持续埋地分布呈对称结构分布，存在左右两个高浓度区；修改孔隙度近地面无爆炸危险。③埋地管道泄漏爆炸范围大且影响时间长，爆炸范围高度呈指数增加，而后浓度随扩散而减低至爆炸下限外；架空管道在85 s前增加且高度比埋地高，85 s后降低；孔隙度越大其影响范围越小。

A comparative study of numerical simulation on underground and aerial pipeline leakage at instantaneous and continuous states

Scholars are still perplexed by the present studies on gas pipeline leakage for lack of reliable data and due to one-side consideration.Based on the previous work,computational fluid dynamics(CFD) is adopted to simulate the gas pipeline leakage under five different conditions,A.aerial instantaneous leakage;B.buried instantaneous leakage;C.aerial continuous leakage;D.buried continuous leakage;E.instantaneous leakage after the soil porosity being changed.From the simulation,the leakage velocity,methane concen...