基于间壁塔严格模型的板间热耦合研究

发布时间：2018-04-18 10:55

本文选题：间壁精馏塔 + 间壁换热　；参考：《北京化工大学》2015年硕士论文

【摘要】：精馏操作是化学工业中应用的最为广泛的分离操作,但是它在一个工业流程中也是最为消耗能量的操作过程。间壁精馏塔作为一种提升过程能效的精馏塔在提出之初就被广为关注。但是,现有的间壁精馏塔研究中,并没有考虑到间壁两侧的传热过程；所以考虑到间壁传热的间壁精馏塔在能耗及经济效益上任然存在改进及提升的空间,这就是本论文的主要研究问题。本文建立了考虑间壁热量耦合的严格平衡级模型,并在模型的基础上,考虑了间壁传热过程。研究发现,在BTX体系中,考虑间壁两侧的热量耦合之后,以进料板为界,不同位置的热量耦合过程,对精馏塔的再沸器负荷的影响,其中包括积极的和消极的影响,并且根据不同塔板上的甲苯T浓度的变化情况,对再沸器负荷变化及其能耗变化做出了以下合理解释：1、进料板之上的热量耦合不利于节能过程,增加了再沸器的总负荷,应当尽量避免：进料板之下的热量耦合有利于节能过程,减少了再沸器的总负荷,在工程允许的范围内,应当尽量实现。2、间壁两侧的热量耦合对于中间组成甲苯(T)组成的浓度变化影响较大,通过减少中间组成向塔顶及塔底分配量,即降低中间组成的返混程度即可达到节能的目的,这同间壁精馏塔的节能原理是一致的。3、以10万吨／年的苯分离过程为例,通过进料之上避免换热,进料板之下进行换热,模拟结果显示,一年可以节省1.OMpa的蒸汽3330吨。本文建立了考虑间壁热量耦合的严格平衡级模型,但在热量耦合形式及热量耦合空间上仍然需要进一步研究,以和工业实际更加吻合。并且本文未考虑动态模拟过程的非线性情况对整个模型的影响,今后的研究可能会在热量耦合形式及空间以及动态模型等方面进一步研究。
[Abstract]:Distillation is the most widely used separation operation in chemical industry, but it is also the most energy-consuming process in an industrial process.As a kind of distillation column for improving process energy efficiency, the interwall distillation column has been widely concerned since its inception.However, the existing research on the interwall distillation column does not take into account the heat transfer process on both sides of the interwall, so there is room for improvement and improvement in energy consumption and economic benefit of the interwall distillation tower considering the heat transfer of the interwall.This is the main research problem of this paper.In this paper, a strict equilibrium stage model considering the heat coupling between the walls is established, and the heat transfer process of the interwall is considered on the basis of the model.It is found that in the BTX system, considering the heat coupling between the two sides of the interwall, the heat coupling process in different positions, taking the feed plate as the boundary, affects the reboiler load of the distillation column, including positive and negative effects.And according to the change of toluene T concentration on different trays, the following reasonable explanation is given for the change of reboiler load and its energy consumption. The heat coupling on the feed plate is not conducive to the energy saving process and increases the total load of the reboiler.It should be avoided as far as possible: the heat coupling under the feed plate is beneficial to the energy saving process and reduces the total load of the reboiler to the extent permitted by the project,It should be realized as far as possible. The heat coupling on both sides of the interwall has a great influence on the concentration change of the intermediate component of toluene. By reducing the distribution of the intermediate component to the top and bottom of the tower, that is, reducing the degree of backmixing of the intermediate composition, the purpose of energy saving can be achieved.The energy saving principle of the interwall distillation column is consistent with that of .3. taking the benzene separation process of 100000 tons per year as an example, heat transfer is avoided over the feed and heat transfer is carried out under the feed plate. The simulation results show that the steam of 1.OMpa can be saved by 3330 tons per year.In this paper, a strict equilibrium order model considering the heat coupling between walls is established, but the heat coupling form and the heat coupling space still need to be further studied in order to be more consistent with the industrial practice.Moreover, the influence of nonlinear process on the whole model is not taken into account in this paper. The future research may be further studied in the form of heat coupling, space and dynamic model.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ053.5

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