海上FLNG气液逆流塔内两相流动与传质特性数值模拟

FLNG是集海上天然气开采、处理、液化、储存和装卸为一体的浮式生产装置,酸气脱除是天然气液化工艺环节中的关键步骤。以应用于FLNG的气液逆流填料塔为研究对象,采用多孔介质模型对规整填料进行建模,模型中考虑多孔介质阻力、气液相间拖曳力、气液相弥散力等的影响,通过引入动网格模型建立海况条件下填料塔的数值模型,定量研究倾斜角度、晃荡角度、晃荡周期对填料塔的气液流场及传质性能的影响。结果表明:倾斜角度3°以上对塔内液体分布影响较大,相比不倾斜工况液体均匀系数降低约30％;晃荡周期为6 s,角度在1°～6°内变化时,液相分布不均性均能得到一定的改善;增加晃荡周期至10 s,净化气中CO2物质的量分数的波动幅度增加了87％。
FLNG is a floating production equipment which integrates the functions of offshore natural gas production, processing, liquefaction, storage and handling.Sour gas removal is a key step in the process of natural gas liquefaction. The gas-liquid countercurrent packed tower installed on FLNG is the general research object, and the porous medium model is used to modeling the structured packing. Considering the effects of porous medium resistance, interphase drag force, dispersion force and gas-liquid phase, and introducing dynamic meshes, a numerical model of packing tower under sea conditions is established, where the impacts of the inclining angle, sloshing angle and vibrational period on the gas and liquid flow field and the mass transfer performance in the packing tower are quantitatively studied.The results indicate that the inclining condition with aninclining angle greater than or equal to 3 degrees can significantly affect the liquid distribution in the column, and the uniformity index of liquid distribution decreases by 30％ around,compared with that in the non-inclining condition. When the sloshing period is 6 s and the value of the inclining angle ranges from 1 to 6 degrees, the non-uniformity can be improved to some extent. The fluctuation range of the mole fraction of CO2 in the purified gas increases by 87％ when the sloshing period is 10 s