中文摘要：

节流分离法是天然气脱水脱烃处理中常用的技术,了解天然气节流过程中的凝结规律有非常重要的意义。研究天然气凝析液中含量较多的正戊烷组分的凝结规律,基于正戊烷的凝结特点建立自发凝结和异质凝结流动统一的数值模型,对正戊烷气体在节流阀内的节流凝结过程进行数值模拟。数值计算结果表明节流时不足以达到正戊烷自发凝结的临界过饱和度,节流阀内只发生异质凝结。正戊烷在节流孔入口即凝结,凝结时间很短,在节流孔内凝结基本完成。研究发现异质凝结时外界核心的初始颗粒半径,初始颗粒浓度和背压比等因素对凝结性质有很大影响。初始颗粒半径和浓度增加时,液滴生长速度减缓,但节流孔出口的凝结液滴质量增大。背压比增加使凝结液滴的生长速率,液滴尺寸和和凝结质量同时减小。

英文摘要：

Throttling separation method is a commonly used gas processing technology,research of condensation characteristics of natural gas is very meaningful.n-pentane is one of the major components in the natural gas liquid.The condensation process of n-pentane in the throttling process is researched using the Eulerian-Eulerian method.According to the condensation characteristics of n-pentane,uniform homogeneous and heterogeneous condensation model in throttling flow is set up.The heterogeneous condensation of n-pentane vapor takes place on foreign nuclei.From the result it is found that the homogeneous condensation of n-pentane can＇t occur until critical supersaturation ratio is attained in the throttle,thus heterogeneous condensation plays a dominant role in the condensation process which is completed in a very short time.The initial radius,concentration of the condensation nuclei and the back pressure ratio have a strong effect on the condensation properties of n-pentane.With increase of the initial radius and concentration of the nuclei,the condensation time gets shorter,and the droplet growth rate becomes slow but the total condensation mass increases.As the back pressure ratio increases,droplet growth rate,the total condensation mass and droplet radius reduce simultaneously.