间壁塔内壁间有无换热对分离效果影响初探

Study on the separation efficiency of dividing wall column with/without heat transfer across dividing wall

间壁塔的应用显著提升了精馏操作的节能效果,减少了设备投资费用,受到了研究者的广泛关注。现有的研究和设计中尚未考虑间壁两侧传热对精馏过程的影响,但实际过程应当存在一定程度的热传递,对精馏操作的分离效果及其能量投入产生影响。为了研究间壁塔隔板的热传递对分离效果影响的趋势与程度,选择在能量投入一定的情况下分析分离效果的变化。本文以丙烷、正丁烷、正戊烷三组分精馏为例,研究当能量输入一定时,间壁塔各塔板浓度与温度参数变化情况,对间壁传热对分离效果影响的趋势与程度做一初探。计算结果表明,对该体系塔釜加热量不变时,首先,间壁塔的间壁传热使得各个组分的产品纯度下降,对分离效果不利;其次,不同间壁传热系数与不同塔板间匹配方式的间壁换热对分离效果不利影响的程度不同。本文对该体系与假设下的传热影响趋势与程度的分析,可以为间壁塔相关工程设计提供一定的参考。

The dividing wall column （DWC） has attracted a wide attention, as its application can significantly enhance energy efficiency and reduce equipment cost. The effect of heat transfer between two sides of the dividing wall on distillation process hasn＆#39;t been considered in both research and industry application yet, while there has to be a heat transfer at certain degree in the process, cause influence to the operation of distillation performance and energy cost. In this paper, a mixture system with propane,n-butane,n-pentane is picked as an example to study the influence tendency and the extent of heat transfer on the separation performance of DWC, according to the change of composition and temperature on each plate, when the energy input is constant. The result shows that, for the studied system, the separating purity of the components is decreased due to heat transfer, as well as separation efficiency; the degree of influence on separation performance is related to heat transfer coefficient and the way of plate matches. The result if this research can provide a reference for relevant engineering design of DWC.