隔离壁精馏塔的简化温差控制

Simplified temperature control strategies for dividing-wall distillation column

虽然隔离壁精馏塔能够大幅度节省设备投资成本与能量消耗,但其操作却需要复杂的控制系统。为了克服这个困难,提出了一种简化温差控制策略,即在精馏段与提馏段实施单温度控制的基础上,采用两个温差控制回路分别控制预分离蒸馏塔的分离操作和侧线采出的产品质量。这里温差控制可以是单温差控制、双温差控制,甚至是多温差控制。以苯、甲苯和二甲苯三元混合物的分离为例,使用Aspen Dynamics商用模拟软件对隔离壁精馏塔的简化单温差控制和双温差控制结构进行了研究,显示了简化双温差控制策略不仅在性能上优于简化单温差控制和传统的温度和温差控制策略,而且具有更强的抗干扰能力。这一结果证明了对隔离壁精馏塔实施简化温差控制策略的可行性与有效性。

Although dividing-wall distillation column（DWDC）can reduce considerably capital investment and utility consumption,its operation needs complicated control strategies.To overcome this drawback,we propose a simplified temperature difference control strategy.By employing two temperature control loops in the rectifying and stripping sections,two temperature difference control loops are utilized to guarantee the separation operation in the prefractionator and maintain the quality of the intermediate product.In this case,the temperature difference can be single,double,or even multiple temperature difference.The separation of a ternary mixture of benzene,toluene,and o-xylene is used to evaluate the proposed simple temperature difference control strategies.The simplified double temperature difference scheme appears to be superior to the simplified single temperature difference and conventional temperature and temperature difference control schemes,in not only dynamic performance but also the capability of suppressing external disturbances.These results demonstrate that applications of the simplified temperature difference control strategies to the DWDC are feasible and yet effective.