用有限元法计算罐车内轻油温度场

油库的卸油系统是油库工艺设计中非常重要的部分,为了解决铁路罐车轻油上卸管路系统存在的气阻现象,减小卸油温度下油品的饱和蒸气压,降低油罐车内油品的温度,对油罐车内轻油的温度场进行了计算。通过分析罐车的几何特性建立了油罐车内轻油温度场数学模型和求解边界条件,并使用ANSYS有限元软件求解该数学模型。其中,在建立数学模型时,把油罐车内轻油温度场简化为二维非稳定传热问题,在求解边界条件中充分考虑了大气温度的变化以及油罐车外壁温度随气温而变化等诸多因素的影响。通过对轻油温度场一个运行周期的计算可求解出在运行周期内某时刻轻油温度场的温度分布,也可以求解出罐车内任意点在整个运行周期中的温度变化情况。方法简便易行、运行稳定可靠。这些问题的求解为研究消除卸油系统中气阻的问题奠定了基础。

CALCULATION OF LIGHT OIL TEMPERATURE FIELD IN A TANK BY FINITE-ELEMENT METHOD

Oil discharge system is the very important part in technological design of an oil house.In order to solve air-blocked phenomena occuring in the light oil discharging pipe system of a rail tanker,reduce the saturated vapour pressure and temperature of the oil product,the temperature field of light oil in the tanker is calculated.Through analysis of the geometrical features of a tank truck,a mathematical model of the temperature field of light oil and solution boundary conditions are established.ANSYS finite element is used to solve the mathematical model.When establishing the mathematical model,simplify the temperature field as 2d unsteady heat transfer problem.In solving the boundary conditions,many factors should be considered fully,such as change of air temperature and outwall temperature of the oil tanker varied with air temperature,etc..Calculation of the temperature field of light oil in a performance period can solve out temperature distribution of the temperature field at some time and temperature change at any point in the whole performance period as well.The method is simple and straightforward,steady and reliable.The solution to these problems lays a foundation for the research of air blocking in the oil discharging system.