基于塔总组合曲线的内部热耦合精馏塔优化设计方法

Optimized design method for internal heat-integrated distillation columns based on column grand composite curve

基于塔总组合曲线(CGCC),提出了一种简化内部热耦合精馏塔(HIDiC)结构的图形设计方法。在完成精馏段(或提馏段)单塔段中间换热器优化设置的基础上,结合精馏段与提馏段CGCC的集成图,以HIDiC的可减小过程总?损为目标,确定HIDiC热耦合中间换热器的最优设计。以苯乙烯-乙苯HIDiC为例,计算结果表明,设置中间换热器后,HIDiC可减小过程总?损最大值为1.951 MW,HIDiC的冷凝器、再沸器负荷分别下降63.6%和68.4%;热耦合中间换热器分别设置于精馏段第2、12、和38块塔板,提馏段第20、28和36块塔板,热负荷依次为0.841、1.496和2.053 MW。

A new graphical design method is presented to simplify the configuration of heat-integrated distillation columns（HIDiCs） based on column grand composite curves（CGCCs）. On the basis of the optimal arrangement of the side-exchangers on single rectifying（or on single stripping） section, the optimal design of side-exchangers located on HIDiCs thermal coupling section will be determined by combining with the integrated diagram from CGCCs of rectifying and stripping sections and maximizing the available reduced total exergy loss of HIDiC. As a case study, a styrene-ethylbenzene HIDiC is simulated to demonstrate the accuracy and rationality of the graphical method. The results show that the available reduced total exergy loss of HIDiC reaches the maximum（1.951 MW）, and the condenser and reboiler duties are reduced by 63.6% and 68.4% after side heat exchangers arrangement, respectively. For achieving this goal, the side-exchangers should be placed on the 2nd, 12 th and 38 th stages of the rectifying and on the 20 th, 28 th and 36 th stages of the stripping sections, respectively. Their heat duties are 0.841 MW, 1.496 MW and 2.053 MW, respectively.