拱顶罐收油过程中油气扩散排放的数值模拟

Numerical Simulation of Vapor Diffusion and Emission in Loading Gasoline Into Dome Roof Tank

拱顶罐收油过程中油品蒸发及油气扩散排放规律对环境污染控制及损耗评估具有重要意义。基于VOF模型、扩散传质模型和RNGk-ε湍流模型,对5000m^3拱顶油罐底部装汽油进行数值模拟研究,分析比较了不同装油速度、不同油罐初始油气质量分数下,罐内油气扩散及蒸发损耗规律。结果表明,增加装油速度,汽油蒸发率减小,损耗率变化不大,约为0.022%;增加油罐初始油气质量分数,汽油蒸发率减小,损耗率增大。建议API(美国石油学会)拱顶油罐收油蒸发损耗评估公式中考虑装油速度和初始油气质量分数的影响。

Study on the evaporation loss in loading gasoline into dome roof oil tank is of great significance for the environmental pollution control and the loss evaluation.Based on the models of volume of fluid（VOF）,mass transfer,and RNGk-εturbulence,the gasoline evaporation loss was numerically simulated during the loading operation for the loading pipe exit near the 5000m^3 dome roof tank bottom,and the oil vapor-air diffusion law was analyzed and compared at the different loading velocities and the different initial vapor mass fractions.The simulation results showed that the total evaporated mass decreased and the qualitative ratio had little change at around 0.022%with the increase of loading velocity,while the total evaporated mass decreased and the qualitative ratio increased with the increase of initial vapor mass fraction.It is recommended that the effects of loading velocity and the initial vapor mass fraction should be considered in API（American Petroleum Institute）loss formula.