基于高速膨胀的气体液化成核模型修正  

Modification of condensation nucleation model for high-speed expansion gas

作　　者：曹学文[1] 靳学堂 夏鹏 杨文[1] 孙文娟[1] 

机构地区：[1]中国石油大学(华东)储运与建筑工程学院 [2]成都城市燃气有限责任公司

出　　处：《石油与天然气化工》2017年第3期36-41,60,共7页Chemical engineering of oil & gas

基　　金：国家自然科学基金项目"基于流体高速膨胀特性的天然气液化机理研究"(51274232)

摘　　要：当前基于高速膨胀的气体液化研究仍处于理论探索阶段,所用成核模型多为内部一致经典成核理论(ICCT),不过该理论应用于低温真实气体时偏差较大。针对理论推导过程的忽略因素,作如下修正:采用逸度求解化学势差,液滴曲率对表面张力影响的修正优选Tolman模型,状态方程优选SRK、低温表面张力推荐LD公式。将模型修正前后的理论结果与水、烷烃的实验数据对比发现,低温时ICCT预测值偏高,最大偏差3~4个数量级;而修正后偏差可降低1~2个数量级,预测偏差降至2个数量级以内,特别对烷烃类偏差均在1个数量级以下。修正后的模型能获得较好的预测结果,可作为天然气高速膨胀液化研究的成核基准公式。The study of condensation for high-speed expansion gas is still on the stage ofexploration, and the popular nucleation model may be Internally Consistent Classical Theory （ICCT）. However, satisfied results can be gained for real-gas in low temperature. As far as theory^s defects, the model is modified as follows： computing chemical potential difference with fugacity and usingTolman model to solve the relation between droplet curves and surface tension; SRK and LD formulawere recommended respectively for state equation and surface tension in low temperature. Compared the modified model and ICCT model with the experiment data, it is found ths higher than experiment value about 3 - 4 order of magnitude while deviation of modified model can be reduced to 1 - 2 order of magnitude, especially for alkane the deviation under 1 order of magnitude. For modified model, more satisfied results can be gained, it can be recommended as standard formula for the study of nucleation.

关 键 词：成核率 ICCT 化学势差 表面张力 高速膨胀 

分 类 号：TE646[石油与天然气工程—油气加工工程]