周期性边界条件对浮顶储罐原油传热过程的影响规律

随着石油储备需求的增加，油罐规模正向大型化以及能适应极限工况的方向发展。准确掌握罐内油品温度场的变化规律，对于保障油库安全经济运行具有重要意义。针对太阳辐射、大气温度等储罐环境的周期性变化条件，运用传热学相关理论，建立了大型双盘浮顶储罐非稳态传热过程的理论模型，通过对模型区域进行离散化得到边界节点的向前差分方程，在确定罐内原油物性参数、储罐传热系数以及边界热通量的基础上，研究得出储罐原油温度场的数值模拟方法。对大庆某10×10⁴ m³浮顶储罐的应用分析表明，罐顶温降速率随着太阳辐射强度以及大气温度的降低而增大；罐壁温降速率受太阳辐射影响较小，随大气温度的降低而增大；罐底近似于绝热，温降速率受外界环境影响较小，研究结果可为优化大型浮顶罐的储存工艺设计及生产管理提供一定的理论支持。

Effect of periodic boundary conditions on heat transfer process of crude oil in floating roof storage tank

With the increase in demand for oil storage,the scale of tanks are developing towards the direction of large scale and better adaptability to extreme working conditions. The change of oil temperature field inside the tank should be accurately grasped, which is of great significance to guarantee safe and economical operation of oil depot. Aiming at the periodic change conditions of tank ambient conditions such as solar radiation, atmospheric temperature and etc., a theoretical model of the unsteady-state heat transfer process of large double-deck floating roof tank is established by using the theory of heat transfer, and the forward difference equations of boundary point are obtained by model region discretion. On basis of determining the physical properties of crude oil in the storage tank, heat transfer coefficient of the tank as well as the heat flux density of boundary, the numerical stimulation method of temperature field in the tank can be studied. The analysis and application of a 10×104 m³ floating roof storage tank in Daqing has shown that the temperature drop rate increases with the decrease of the solar radiation intensity and the atmospheric temperature. The effect of solar radiation on temperature drop rate of tank shell is small, which increases with the decrease of atmospheric temperature. The tank bottom is approximate to adiabatic state and the effect of the external environment on temperature drop rate is small. The results can provide theoretical support to optimize the storage process design and manufacturing management of large floating roof tanks.