单盘式浮顶油罐内含蜡原油温降规律数值计算研究

Numerical study on the temperature drop characteristics of waxy crude oil in a single-plate floating roof oil tank

建立了考虑含蜡原油非牛顿性和析蜡相变过程的单盘式浮顶油罐内含蜡原油温降物理数学模型,并发展了一体化耦合求解方法。模型中,采用幂律方程描述罐内含蜡原油的非牛顿特性;采用湍流大涡模拟方法计算罐内含蜡原油的湍流流动过程;采用焓多孔介质理论计算罐内含蜡原油的析蜡相变过程,并跟踪罐内含蜡原油的相变界面。利用文献中的结果对本文模型进行验证。基于验证的程序,对实际单盘式浮顶油罐内含蜡原油温降过程进行计算,研究罐内含蜡原油温降过程的演化规律,并对罐顶、罐底凝油层的增长以及罐顶、罐底和罐壁处传热量的变化规律进行研究。研究结果可为单盘式浮顶油罐的设计和生产方案的制定提供一定的指导。

Physical and mathematical models for the temperature drop process of the waxy crude oil in the single-plate floating roof oil tank are established with the consideration of non-Newtonian behavior and wax precipitation, and a coupled integrative numerical procedure is developed. In this research, the non-Newtonian behavior is described by the power-law equation. The turbulent flow is calculated by Large Eddy Simulation(LES) method. Wax precipitation of the waxy crude oil in the tank is simulated by the enthalpy-porous media theory, in which the gel oil interface is tracked. The numerical program is validated by the results obtained from the literatures. Based on the verified program, temperature drop process in a single-plate floating roof oil tank is calculated, and the evolution characteristics of the waxy crude oil in the tank are studied. Furthermore, gel oil growth on the tank top and tank bottom and heat flux on tank top, tank bottom and tank wall are also investigated in this research. The research results provide guidance for the scientific designing of the single-plate floating roof oil tank and making schedule of waxy crude oil turnover reasonably.