覆土油罐油气泄漏扩散数值模拟

Numerical Simulation of Hydrocarbon Gas LeakageDiffusion in Covered Oil Tank

为了研究覆土油罐油气泄漏过程中油气时空分布规律,基于湍流k-ε标准模型,对某油库覆土油罐油气在罐室内泄漏扩散进行数值模拟研究,探究油气在油罐泄漏后扩散轨迹,分析油气在覆土油罐罐室内水平方向和竖直方向上油气体积浓度随时间变化规律。研究结果表明:油气扩散过程划分为准静态期、梯度上升期和稳定期;准静态期在相同高度处相等,高度越高准静态期越长;梯度上升期随高度升高而油气体积浓度增长速率越小,紊乱区内相同高度处距离泄漏口越近油气体积浓度增长速率越大,稳定区内相同高度处油气体积浓度增长速率相同;在稳定期内随高度增加油气体积浓度减小,罐室内油气体积浓度达到稳定期所需时间相同,紊乱区内相同高度距离泄漏口越近油气体积浓度越大且相对泄漏口呈对称分区存在,但稳定区内相同高度处油气体积浓度相同。罐室内超过一定高度时油气体积浓度低于安全油气体积浓度,即处于安全区。研究结果对安全处置覆土油罐油气泄漏具有重大意义。

In order to study the temporal and spatial distribution of gas in theevent of gas leakage in overlying oil tanks,based on the turbulence k-εstandard model,the numerical simulation of oil and gas leakage diffusion of a tank chamber in an overburden oil tank is carried out.The dispersion trajectory of hydrocarbon gas after oil tank leakage is explored and the variation law of hydrocarbon gas concentration with time in horizontal and vertical direction in the covered oil tank chamber is analyzed.The results show that the hydrocarbon gas dispersion process is divided into quasi-static period,gradient rising period and stable period.The quasi-static period is the same at the same height,and the higher the height,the longer the quasi-static period will be.In the gradient rising period,as the height increases,the smaller the hydrocarbon gas concentration growth rate is.In the disturbance area,the closer to the leakage at the same height,the higher the hydrocarbon gas concentration growth rate will be.In the stable area,the faster the volume concentration growth rate,the same the hydrocarbon gas volume concentration growth rate is with the same height.The lower the hydrocarbon gas volume concentration is with the increase of the height,the time required for the hydrocarbon gas volume concentration in the tank chamber to reach the stable period is the same.The closer to the leakage at the same height within the disturbance area,the greater the hydrocarbon gas volume concentration will be and the relative leakage point is symmetrical,but the hydrocarbon gas volume concentration in the stable area is the same with the same height.It is also found that when hydrocarbon gas volume concentration is lower than the safe hydrocarbon gas volume concentration over a certain height,namely the safe zone.The research results are of great significance for the safe handling of hydrocarbon gas leakage in covered oil tanks.