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重油梯级分离技术作为重油轻质化的新工艺,它通过耦合渣油萃取和沥青喷雾造粒过程,有效的简化重油处理的工艺流程,减少设备成本。在此工艺流程中,处于超临界状态的戊烷的闪蒸速率对沥青造粒质量起到了关键作用。根据其减压过程中的质量和热量传递机理,改进了戊烷闪蒸的经验模型,并将其植入到CFD软件FLUENT中,使其能较为准确的预测闪蒸雾化的非平衡热力学过程。同时对气液戊烷和沥青的三相闪蒸流动过程进行了数值模拟,结果显示喷嘴结构是控制闪蒸速率的关键,直接影响了沥青造粒的质量;此外沥青相的加入为戊烷的相变过程提供了更多能量,提高了戊烷在喷嘴内的汽化率。
As a new process of heavy oil light-weight separation, the heavy-oil cascade separation technology can effectively simplify the process of heavy oil treatment and reduce the equipment cost by coupling residual oil extraction and asphalt spray granulation process. In this process, the flash rate of pentane in the supercritical state plays a key role in the quality of bitumen pellets. According to the mass and heat transfer mechanism in the decompression process, the empirical model of pentane flash is improved and implanted into the CFD software FLUENT to make it more accurate to predict the non-equilibrium thermodynamic process of flash atomization . At the same time, the three-phase flash flow of gas-liquid pentane and bitumen was numerically simulated. The results show that the nozzle structure is the key to control the flash rate and directly affects the quality of asphalt granulation. In addition, the addition of bituminous phase to pentane The phase change process provides more energy and raises the pentane vaporization rate in the nozzle.