精馏过程计算中相对挥发度的平均值近似  

Approximation of Average Relative Volatility in Distillation Process Calculation

作　　者：白润生[1] 

机构地区：[1]清华大学核能技术设计研究院

出　　处：《石油化工》1999年第4期247-249,共3页Petrochemical Technology

摘　　要：以Ｆｅｎｓｋｅ公式计算全回流条件下的最少理论级数时，需要分离组份间的相对挥发度。当相对挥发度非恒定时，需计算平均相对挥发度。常用的两端点值几何平均法在相对挥发度变化较小的情况下误差较小。而当相对挥发度变化大时，需加入第三点的相对挥发度值。合理选取第三点的位置可有效提高计算精度。本文提出了第三点位置的确定方法。该方法理论明确，计算简单，用于相对挥发度变化较大及级数较多的情况时，优于其它方法。This paper presents a method to compute the average relative volatility when Fenske Equation is used to obtain the minimum number of stages at total reflux.Besides the relative volatilities at the first and the last stage,another stage between them is required to provide more information about vapor liquid equilibrium relation.The location of the middle point presented in this paper is easy to determine and usually is not the median or the feed position.When n=3,this approach is identical with analytical solution.The results from several cases show that this method is more accurate than the others when the relative volatilities vary greatly.

关 键 词：精馏 过程计算 相对挥发度 平均值近似 

分 类 号：TQ028.13[化学工程]