拱顶油罐顶部传热系数的计算及影响因素分析

Calculation and Influence Factor Analysis About HeatTransfer Coefficient of the Top of Vault Oil Tank

对拱顶油罐顶部传热过程和顶部传热系数的计算原理及方法进行了详尽的分析和阐述。罐内油品通过油气界面与油气空间层进行传热，油气空间层内产生自由运动和对流运动，油品蒸汽和空气都参与传热，与静止的气体热传导相比，传热过程要增强。通过算例，利用单元法，对该传热系数进行了精确的计算，并与文献报道的该系数取值进行了对比。计算表明，该系数取０．３～０．７Ｗ／（ｍ２·℃）较为合适，该系数与温度的关系曲线说明了该系数随油品温度变化而变化，分析比较了油罐装满系数、罐容、环境温度、风速等因素对该系数的影响，这些因素变化时，该系数的值也不一样。

The full analysis and expoundness are about heat transfer process, heat transfer coefficient calculation principle and method of the top of vault oil tank. There is heat transfer between oil in tank and interior space layer mainly consisting of oil steam and air through interface of oil and space layer. Free movement and convection occur in the space layer. All the oil steam and air join to transfer heat. Compared with heat exchange of immobile gas, heat transfer will srengthen. In the example, heat transfer coefficient is calculated precisely by the cell calculation method and the result is contrasted to the reportorial ones in literature. The calculation shows that it is proper to get the coefficient from 0.3 to 0.7 watt per square meter and per degree. A distributing curve of heat transfer coefficient to oil temperature is drawn with the data calculated. The curve shows how the coefficient changes with the change of oil temperature. The coefficient influence factors such as oil tank filling coeffcient, tank volume, environment temperature, wind speed and etc, are analyzed and contrasted each to other. The values of the coefficient are different when these factors change. In calculation, any experience value can not reflect real circumstances, and precision can not be guaranteed. But precision will increase with the method mentioned.