塔中换热器的模拟研究

Simulation of the Tower Heaters

以苯-甲苯-二甲苯的分离为例,通过流程模拟软件ASPEN对存在塔中换热器的精馏塔进行了模拟。考察了塔中冷凝器、再沸器的位置,抽出与回流位置,抽出量以及气化率对精馏塔整体能耗的影响。模拟结果表明,塔中冷凝器应设置在塔的精馏段,塔中再沸器应设置在提馏段;塔中冷凝器回流位置应在抽出位置上方,塔中再沸器回流位置应在抽出位置下方;随着塔中再沸器和冷凝器抽出量的增加,全塔能耗随之增加;冷凝率和气化率对全塔能耗影响不大。塔中冷凝器或再沸器的加入,都将导致塔的能耗总量增加。在设计过程当中,要全面考虑能耗总量与公用工程的相关性,做到最优的经济性。

Based on the example of the separation of benzene-toluene-xylene,process simulation software ASPEN was used to simulate the distillation towers with tower heat exchanger. The impact of the location of condenser and reboiler,the position of the withdraw and backflow,effluent ratio,as well as the vaporization ratio on total energy consumption of distillation was investigated in the simulation. Through the compare of energy consumption result,conclusion can be reached as follows. The tower condenser and tower reboiler should be set in the rectifying section and stripping section respectively. The back flow position should be set above the out flow of tower condenser. The back flow position should be set below the out flow of tower reboiler. With the increase of out flow rate of condenser and reboiler,total energy consumption went up. The condensation and vaporization ratio had little effect on the energy consumption. Extra condenser or reboiler would lead to the increase of energy consumption. In the design process,correlation of total energy consumption and utility should be overall considered to achieve the best economical efficiency.