【摘要】 为了确保大型液化天然气(LNG)板翅式换热器冷箱并联管路流量均布性,基于计算流体力学(CFD)方法,根据实际板翅式换热器冷箱并联管路的形式,简化并建立了并联管路物理模型,模拟研究了气液两相流的流量均布特性。研究结果表明:当气液两相流速固定时,增加两相的体积含气率会先降低后提高流量分配的均匀性;当两相的体积含气率固定时,流量分配均匀性随流速的增加而变好。不同管路布置方式对并联管路流量分配影响不同。为提高并联管路流量的均布性,当管道水平布置时,优先考虑水平上进下出式;当管道垂直布置时,优先考虑垂直向下流入式。上述研究成果将为大型LNG板翅式换热器冷箱并联管路运行参数和布置方法的设计提供重要的理论依据。更多还原

【Abstract】 In order to ensure the flow distribution characteristics of parallel pipelines in plate-fin heat exchanger cold-box in large scale liquefied natural gas( LNG) unit,the parallel pipelines model is simplified and established based on computational fluid dynamics( CFD) numerical simulation and the actual forms of parallel pipelines in plate-fin heat exchanger cold box. The numerical simulation of the gas-liquid two-phase flow distribution characteristics in the parallel pipes is studied. The results show that when the velocity of two-phase is fixed,the flow distribution uniformity displays first deteriorate then improve with increase of the gas volume rate of twophase flow,and the flow distribution uniformity is improved with increase of the flow velocity when the gas volume rate of two-phase flow is fixed. In order to improve the flow distribution uniformity of parallel pipelines,the style of up-in and below-out in should be prior considered when the pipeline is arranged horizontally,however,when the pipeline is arranged vertically,the style of flowing up to down should be prior considered. The study results will provide theoretical foundation for design of operating parameters and arrangement methods in parallel pipelines of LNG plate-fin heat exchanger cold-box.更多还原