气相分配比对隔板精馏塔性能和操作影响的模拟研究(英文)

Operability problem of dividing wall column (DWC) raised by vapor split was investigated by numerically analyzing four cases defined by different compositions of a three-component mixture. DWCs were firstly designed for each case by optimizing the vapor split to the two sides of the dividing wall, and then their feasibilities and total annual costs in operation were evaluated against different vapor split ratios. The analysis on the operability of the DWC for four cases was made based on two scenarios: (1) vapor split is shifted by the vapor resistance difference between the column sections in the two sides of the dividing wall and (2) the feed composition is changed. It was demonstrated that the positioning of the dividing wall and the decision on the vapor split may affect significantly the operability of a DWC.     

减少气相耦合流股隔板塔的严格模拟研究

隔板塔虽然有显著的节能优势,但因在操作中无法控制和调节气相分割比这一重要参数,其工业应用受到了限制。为此Agrawal等提出了隔板塔的改进流程,通过增加塔段和冷凝器或者再沸器,有效避免了因气相分割比导致的局限性。Agrawal等仅用简捷法分析证明了几种新的结构和原隔板塔是等价的。用Aspen Plus软件,选用不同物系,对改进型隔板塔流程和原流程进行了严格模拟和比较,证实了改进流程和原流程的等效性。同时给出多种改进流程的塔径设计计算结果,对改进的隔板塔实际设计可行性进行了讨论。     

热集成复杂精馏系统综合的研究

将夹点分析法应用于热集成复杂精馏系统综合的换热网络设计中,避免了以换热网络结构作为独立变量,建立了一个以预分馏塔组分回收率、回流比及操作压力为连续变量,以分离序列和热耦合方式为离散变量的混合整数非线性规划(MINLP)模型。该模型用改进的模拟退火算法求解,可同时得到优化的流程结构和操作参数。对多个五组分混合物分离问题进行了求解,并对不同优化方案的优化结果及其经济性作了比较和分析,结果表明采用热集成复杂精馏塔流程可以显著地降低系统的总费用,还表明该方法是求解热集成复杂精馏系统综合问题的有效方法。     

Synthesis of Water Utilization System Using Concentration Interval Analysis Method （Ⅱ） Discontinuous Process

The first part of the series of this article proposed a systematic method for the synthesis of continuous water-using system involving both non-mass-transfer-based and mass-transfer-based operations.This article,by extending the method,proposes a time-dependent concentration interval analysis（CIA）method to solve the problems associated with the synthesis of discontinuous or batch water-using systems involving both non-mass-transfer-based and mass-transfer-based operation.This method can effectively identify the possibility of water reuse and the amount of water reused under time constraints for minimizing the consumption of freshwater in single or repeated batch/discontinuous water-using systems.Moreover,on the basis of the heuristic method adapted from concentration interval analysis method for the continuous process network design,the network design for the discontinuous or batch process can be obtained through the designs for every time interval.Case study illustrates that the method presented in this article can simultaneously minimize the freshwater consumption in single or repeated batch/discontinuous water system and can determine a preferable storage tank capacity for some problems.     

受限空间内浮升气泡与液体间传质行为实验研究

采用紫外诱导荧光(UIF)实验方法,研究Hele-Shaw狭缝受限尺度对受限空间内浮升气泡流体力学与气液传质行为的影响。实验中以二苯并[b,e]吡啶作为荧光剂实现了受限空间内CO₂溶液浓度分布及其气泡运动速度的定量测量,获得了CO₂在受限空间内运动过程中的传质量和气泡动力学参数,并分别计算气泡受限空间内液膜区和自由接触区的传质速率。分析得到受限空间中不同狭缝宽度内CO₂的传质行为,分析了受限尺度对CO₂-水体系传质过程的影响。     

考虑中间换热器的能量集成精馏序列合成

针对考虑中间换热器（IHE）的精馏序列合成问题,提出基于随机优化策略的能量集成非清晰精馏序列（IHE-HIDSs）合成方法。通过对精馏序列分离任务合并处引入二元0/1变量表示是否存在IHE,以精馏序列的年总成本（TAC）为优化目标,建立了该合成问题的隐式混合整数非线性规划模型（MINLP）,通过模拟退火和粒子群优化（SA-PSO）混合随机优化算法进行求解。为验证在精馏序列合成中同时考虑IHE的必要性以及所提出合成方法的有效性,对五组分醇类混合物和五组分烷烃类混合物两个算例的精馏序列合成问题进行了研究。结果表明,相比同时考虑热耦合和能量集成的精馏序列,IHE-HIDS具有更低的TAC。此外,所提出的方法可以在合理的计算时间内以高概率获得多个分离序列方案。     

基于带权有向图的非清晰复杂精馏序列的合成方法

在精馏系统中非清晰分离能够克服清晰分离所固有的返混效应,从而提高系统能效。基于数据结构理论,提出了非清晰精馏序列的合成与优化方法。对于N组元混合物的分离,合成的精馏序列由N-1个精馏塔构成,且其中的非清晰分离任务含有所允许的任意多个中间分配组分。为了合成上述分离序列,利用带权有向图建立了一种新的精馏分离序列模型,并基于“vector”动态数组,提出了一个同时拥有数组和链表优点的带权有向图的储存结构。序列合成过程定义了一系列的相关操作,且选择广度优先的策略以提高合成效率。算例证明了该方法在精馏序列合成和优化的高效性。算例结果表明该算例的最优分离序列可以有效减少设备投资和能耗。     

基于粒子群优化算法的水分配网络系统综合的最优化研究

The problem of optimal synthesis of an integrated water system is addressed in this study, where water using processes and water treatment operations are combined into a single network such that the total cost of fresh water and wastewater treatment is globally minimized. A superstructure that incorporates all feasible design alterna- tives for wastewater treatment, reuse and recycle, is synthesized with a non-linear programming model. An evolutionary approach--an improved particle swarm optimization is proposed for optimizing such systems. Two simple examples are .Presented.to illustrate the global op.timization of inte.grated water networks using the proposed algorithm.     

氢同位素的低温精馏分离及模拟技术

低温精馏分离氢同位素的技术,是可使聚变反应器燃料循环使用的有效方法。在研究低温精馏氢同位素的过程中,必须考虑到物系的特殊性,如氚具有衰变热、氢溶液的非理想性,以及严格的分离要求等。文章从理论及实际出发综述了氢同位素低温精馏体系的发展过程,并比较和讨论了各种流程的构造及特点,总结了氢同位素低温精馏模拟研究的发展历程和目前状况。提出进一步研究低温精馏分离氢同位素的必要性。     

考虑环境影响的间歇过程多目标最优化设计

同时考虑费用和环境影响的间歇化工过程多目标最优化设计问题的求解,通常的做法是使用权重系数法,将其转变成单一目标来优化。但大多数情况下,这种权重系数很难确知。因此,有必要提供多个解以便于设计者作出合理的最终选择。采用多目标遗传算法和线性规划相结合的方法求解出间歇化工过程优化设计模型的非劣解集,并与不同权重系数下的单目标算例进行了比较。结果表明,用多目标遗传算法求解间歇化工过程是有效的。这为设计者在间歇化工过程最优化研究考虑环境因素的决策提供了更多的选择。