加油站油气扩散与回收效果的数值分析

Numerical analysis of gasoline vapor diffusion and recovery results in gasoline stations

加油站排放出的油气是有毒有害的气体。目前控制油品蒸发损耗的有效方法是采用油气回收系统。基于湍流模式理论,采用FLUENT软件,模拟加油站在使用油气回收系统前后空气中油气浓度分布情况及风对油气扩散的影响,得到油气浓度等值面图、直线及点上浓度变化曲线图。模拟结果表明,实施油气回收,其大气净化率可高达95%以上,因此明显减小加油站火灾隐患及环境污染,并可减少经济损失及节约加油站占地面积。另外,风对油气扩散稀释有明显的影响,如距排放口下风侧5 m处,相对于风速1 m/s,风速为5、8 m/s时的大气净化率分别为54%、71%。虽然无法降低油气排放总量,但是随着风速的增加大气净化率随之变大,可以减少油气浓度值过高造成的危害。

Gasoline vapor from gasoline stations is poisonous and harmful, and the vapor recovery system is an effective method to control and recover the discharged vapor. Based on the turbulence model theory and by FLUENT software, the vapor distribution in the surroundings of gasoline station was numerically simulated and analyzed, various vapor concentration profiles in the station space were provided, and the effect of the recovery system and wind to the vapor diffusion were discussed and evaluated. The results show that the vapor concentration in the air is high, and that after the recovery system is put in practice, the concentration can not only be reduced by more than 95% and then hidden fire accident and environmental pollution will be lowered, but also the user can give high payback benefits from recovering valuable resources and reducing the station occupation area. Although the wind is unable to reduce the gross discharged vapor, it can dilute the concentration in positive proportion to the wind speed and lower the harm from the high concentration. When the wind speed are 5 m/s and 8 m/s, the concentration at the point in 5 m distance to the vapor exit of tank or gasoline box of car along the wind direction can be reduced bv 54% and 71% relative to wind speed 1 m/s respectively.