Abstract: In the process of heating and transporting fuel oil by the motor pipeline laid with bare pipe, due to the effect of low temperature and strong heat exchange in winter, the fuel oil has large heat loss, fast temperature drop, rising viscosity, large pressure drop, loss of liquidity, and is prone to condensation accidents. The flow and heat transfer process of fuel oil in the test section of the loop test device was simulated numerically by using the fuel oil produced by a refinery of CNPC in Qingdao as the experimental medium, and a three-dimensional coupled model of flow and heat transfer was established. The computing region was divided by a staggered grid system. The convection-diffusion equation was discretized by using second order upwind and the sub-relaxation alternating direction block iterative method was used to solve the discretization equation. Numerical simulation results show that: the oil temperature near the tabe wall decreases due to the effect of cooling water on the outer wall of the test section, and the closer to the tube wall, the more the temperature decreases. From the inlet to the outlet of the oil flow, the temperature of the inner wall of the pipe appears a floating drop, and the thickness of the thermal boundary layer of the fuel oil decreases.

Key words: pipeline engineering, marine fuel oil, flow and heat transfer coupling characteristics, numerical simulation, mobile pipeline

摘要： 裸管铺设的机动管线加热输送燃料油过程中，由于冬季低温和强换热的作用，使得燃料油热损失大，温降快，黏度上升，压降大，失去流动性，易发生凝管事故。以中石油驻青岛某炼油厂所产舰用燃料油为实验介质，对燃料油在环道实验装置测试段中流动和传热过程进行数值模拟，建立了三维流动和传热耦合模型，采用交错网格体系划分计算区域，选用二阶迎风格式对流-扩散方程进行离散，运用亚松驰的交错方向块迭代法求解离散方程。数值模拟结果表明：由于测试段管外壁冷却水的作用，近壁处油温会下降，越靠近管壁，温度下降越多；从油流进口处到出口处，管内壁温度出现浮动式下降，燃料油的热边界层厚度降低。

关键词: 管道工程, 舰用燃料油, 流动传热耦合特性, 数值模拟, 机动管线