摘要
在无实验参数的条件下模拟汽液平衡,计算量大,计算过程复杂,对一些特殊的混合物计算误差较大,限制了模拟计算的应用范围,本文采用改进的UNIFAC计算活度系数模型和修正的拉乌尔定律模拟汽液平衡,再用构造饱和蒸汽压计算误差函数迭代计算汽液平衡温度,用试位法克服迭代计算中的收敛问题。改进了试位法的终止条件,通过调整迭代的初始温度,大大降低了迭代次数,有效提高了计算速度,对一些特殊的混合物也具有较好的模拟结果,在5 931 mmHg压力下,对水-乙酸混合物模拟计算的平均迭代次数仅19次,在Visual C++环境中,用面向对象的方法,实现了无实验参数模型模拟汽液平衡,数据处理用独立的类完成,并采用了动态分配内存的方法处理数据,使计算模块具有较好的独立性和复用性,最后在不同的压力下,模拟计算了乙醇=水、水=醋酸和苯-甲苯等混合物,证明该法可模拟实际过程,计算速度较快,模拟效果较好。
Without parameters of experiment to simulate VLE are computationally expensive and complex. For some complex compounds that will lead to erroneous results and has limited usage. In this paper, the improved model of UNIFAC for calculating the activity coefficient and modified Raoult＇s law were applied on simulating VLE. Then calculate the temperature of VLE by the error function in the iteration. The convergence problem is solved by the method of regular false iteration. Through modifing the terminal condition, adjust the initial temperature to reduce iteration number and to improve computing speed. The method is also effective on simulating some complex compounds. To simulate the compound of water-acetic under pressure of 5 931 mmHg, the average of iteration time are as low as only 19 times. In visual C＋＋, simulate the VLE without parameters of experiment based on the method of OOP. The data are processing by the independent class. The data processing module has the ability of independence and repeated usage. In the processing module, memory is allocated dynamically. Under different pressure, ethanol-water, water-acetic acid and benzene-toluene, etc., have been simulative calculated. The results indicate that the method of simulation can be used in VLE simulation.
出处
《计算机与应用化学》
CAS
CSCD
北大核心
2010年第9期1289-1292,共4页
Computers and Applied Chemistry
关键词
汽液平衡
模拟
迭代
VLE, simulation, iteration
