带中间换热器的热泵精馏隔壁塔的综合设计与优化研究

常规隔壁塔所需加热量全部由温度最高的塔底再沸器提供，所需冷却量全部由温度最低的塔顶冷凝器提供，从而造成隔壁塔较大的有效能损失。同时，塔段间较强的热耦合会使塔内产生剩余汽（液）相流量，从而使能耗和投资费用增加。针对以上问题，本项目提出了一种带中间换热器的热泵精馏隔壁塔的设计，将热耦合精馏、热泵精馏和带中间换热器精馏的节能优势综合到一起，从热力学第一定律和第二定律两方面提高隔壁塔的节能效率。本项目考察了物系特性对常规隔壁塔节能效率和塔内剩余汽液相流量的影响；分析了带中间换热器隔壁塔的多种实现方案；设计优化了热泵精馏与隔壁塔的综合流程；将中间换热器和热泵精馏进行合理组合，建立了带中间换热器的热泵精馏隔壁塔的综合优化流程，分析和比较了不同分离物系和进料组成下，该综合流程的节能效率和投资费用情况。最后对主要节能方案进行了比较和评价。

Dividing wall column (DWC) does not always have high thermodynamic efficiency for the reasons that all the heat input is done at the highest temperature level and all of the heat removal is done at the lowest temperature level. At the same time, vapor and liquid transfers between different sections produce an unavoidable excess of vapor or liquid in some of them, increasing both the operating and investment costs. In this project, a vapor recompression dividing wall column with intermediate exchanger is suggested, for the aims of improving the thermodynamic efficiency and spreading the application scope of dividing wall column. The effects of mixtures property on energy saving efficiency and the excess of vapor(liquid)of dividing wall column are investigated, then different types of dividing wall column with intermediate exchanger and different types of vapor recompression dividing wall column are designed and optimized. On these bases, the vapor recompression dividing wall column with intermediate exchange is explored. Furthermore, its structure and operating parameters are optimized to get the minimum total annual cost(TAC).Finally the energy saving efficiencies and TACs of above types of dividing wall columns are compared and evaluated.