考虑水力学的内部热集成反应精馏塔设计

发布时间：2018-05-14 06:47

本文选题：内部热集成 + 反应精馏　；参考：《中国海洋大学》2015年硕士论文

【摘要】：反应精馏塔是将化学反应和产物分离耦合到一个塔中的典型的化工过程强化技术。内部热集成反应精馏将内部热集成概念应用于反应精馏塔中,将传统的反应精馏塔分割为两个独立的塔,并在不同的压力下操作,两塔之间通过塔壁、换热翅片等换热介质进行热量交换,通过热量的内部集成来提高能量的利用效率,降低系统能耗和费用。本文建立了一种内部热集成反应精馏塔设计的方法,并将方法应用于环氧乙烷水合反应体系,对其进行了内部热集成反应精馏塔的设计。(一)建立一种内部热集成反应精馏塔设计的方法。(1)对传统的反应精馏塔进行设计,然后将反应精馏塔分割至两个独立的塔中,并且在不同的压力下操作,然后对两塔分割后塔内的温度分布进行内部热集成热力学可行性分析；(2)选择合适的塔结构,根据塔的流程参数及结构特点选择合适的换热位置和换热量设计方法,设计内部热换热量；(3)研究塔内的物理空间条件,通过计算塔内能提供的换热面积,并与换热所需的换热面积进行比较,对塔进行水力学可行性分析。(4)调整塔结构或改变内部换热量,使水力学达到可行,完成内部热集成反应精馏塔的设计。(二)将建立方法应用到环氧乙烷水合体系中,分别设计了同心轴式内部热集成反应精馏塔(同心轴式塔)和多管式内部热集成反应精馏塔(多管式塔)。(1)首先以理想内部热集成(再沸器负荷为零)为目标,以等换热量设计的方法,设计了EO水合反应的同心轴式塔,然后对塔进行了水力学分析,发现由于达到再沸器负荷为零需要的换热量非常大,塔内空间不足以提供内部换热所需的换热面积,水力学不可行。然后研究了塔内换热量对塔内温度、汽液相流量、塔径、塔负荷等的影响,结果表明,降低塔内换热量可以解决理想内部热集成水力学不可行的问题。因此降低了塔内换热量,以水力学可行前提下的最大内部热集成为目标,设计了EO水合体系同心轴式部分内部热集成反应精馏塔。通过能耗分析发现同心轴式塔比传统反应精馏塔节省能耗达29%。(2)设计了多管式部分内部热集成反应精馏塔。内塔分为41个塔径为0.4m的小塔时负荷设计规定,比传统反应精馏塔节能约13.5%。(3)分别对传统反应精馏塔、同心轴式塔和多管式塔进行了经济性评价,结果表明,同心轴式塔与多管式塔年度费用相差不大,同心轴式塔年度费用略低于多管式塔0.9%。与传统反应精馏塔相比,同心轴式塔和多管式塔能大约节省达63%的年度总费用。本文建立的方法,将为内部热集成反应精馏塔的设计优化提供理论指导和模型支持,特别是考察水力学的内部热集成反应精馏塔的设计提供方法借鉴。
[Abstract]:The reaction distillation column is a typical chemical process strengthening technology which combines chemical reaction and product separation into a single column. Internal thermal integration reactive distillation applies the concept of internal thermal integration to the reaction distillation column. The traditional reactive distillation column is divided into two separate columns and operated under different pressures, and the two columns pass through the tower wall. In order to improve the energy efficiency and reduce the energy consumption and cost of the system, heat transfer media such as fin is used to exchange heat, and the internal integration of heat is used to improve the efficiency of energy utilization. In this paper, a design method of internal thermal integrated reaction distillation column is established. The method is applied to ethylene oxide hydration reaction system, and the internal thermal integrated reaction distillation column is designed. (1) to establish a method for the design of an internal thermal integrated reaction distillation column. (1) to design the traditional reactive distillation column, and then divide the reaction distillation column into two separate columns and operate under different pressures. Then, the thermodynamics feasibility analysis of internal thermal integration is carried out on the temperature distribution in the tower after the two towers are separated. (2) the appropriate tower structure is selected, and the appropriate heat transfer position and heat transfer design method are selected according to the flow parameters and structural characteristics of the tower. The physical space conditions in the tower are studied, and the heat transfer area provided by the tower is calculated and compared with the heat transfer area required by the heat transfer. The hydraulic feasibility analysis of the tower. 4) adjust the tower structure or change the internal heat transfer to make the hydraulics feasible and complete the design of the inner thermal integrated reaction distillation column. (II) the application of the established method to the ethylene oxide hydration system, First, the ideal internal thermal integration (zero reboiler load) is the goal of the design of the concentric inner thermal integrated reaction distillation column (concentric column) and the multi-tube internal thermal integrated reaction distillation column (multi-tube tower. The concentric column of EO hydration reaction was designed by the method of equal heat transfer design, and the hydraulic analysis of the tower was carried out. It was found that the heat transfer needed to reach zero load of the reboiler was very large. The space in the tower is not enough to provide the heat transfer area needed for internal heat transfer, and hydraulics is not feasible. Then, the effects of heat transfer in the tower on the temperature in the tower, the flow rate of steam and liquid phase, the diameter of the tower and the load of the tower are studied. The results show that reducing the heat transfer in the tower can solve the problem that the ideal internal heat integration hydraulics is not feasible. Therefore, the heat transfer in the column is reduced, and aiming at the maximum internal thermal integration under the condition of hydraulics feasibility, the concentric partial internal thermal integration reaction distillation column of EO hydration system is designed. Through energy consumption analysis, it is found that the energy saving of the concentric column is up to 29. 2) the multi-tube partial internal thermal integrated reaction distillation column is designed. The inner tower is divided into 41 small towers with a diameter of 0.4m, which is designed for hourly load, which saves energy about 13.53.The conventional reactive distillation tower, concentric column and multi-tube tower are evaluated respectively. The results show that, The annual cost of concentric tower is slightly lower than that of multi-tube tower, and the annual cost of concentric tower is slightly lower than that of multi-tube tower. Compared with traditional reaction distillation column, the annual total cost of concentric column and multi-tube column can be reduced by 63%. The method established in this paper will provide theoretical guidance and model support for the design and optimization of the inner thermal integrated reaction distillation column, especially for the study of the design of the internal thermal integrated reaction distillation column in hydraulics.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ053.5

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