基于神经网络混合整数线性规划的精馏分离序列优化综合

针对精馏分离序列综合问题,运用图论方法研究网状超级结构。结合相对费用函数建立了混合整数线性规划模型。开发了面向大规模精馏分离序列综合问题的自动求解程序,实现了10组分精馏分离序列综合问题的成功解算,探索了神经网络混合整数线性规划的思想框架。     

应用遗传算法实现精馏分离序列优化综合

阐述了采用遗传算法求解具有组合爆炸特征的精馏分离序列综合问题。首先在数据结构上将精馏分离序列抽象为二叉树结构编码,然后应用图论方法建立起有效的交叉和变异算子,最后对10组分精馏分离序列综合问题实例进行求解。结果表明,遗传算法对最优解命中率达80％,平均空间搜索率仅为0．0318。因此遗传算法能够成功解算大规模精馏分离序列优化综合问题。     

基于自适应并行禁忌搜索的精馏分离序列优化综合

由于精馏分离序列与二叉树之间具有同构性,在数据结构上精馏分离序列可以抽象为二叉树.采用图论方法建立了二叉树相邻切分点变换机制,进而形成有效的邻域结构.将自适应机制和并行技术引入禁忌搜索算法中,根据记忆频率信息自适应调整禁忌长度与候选集规模,通过搜索任务分配安排形成多任务并行处理.数值实验表明自适应并行禁忌搜索算法能够成功解算大规模精馏分离序列优化综合问题.     

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。     

基于模糊逻辑推理的精馏分离序列优化综合

模糊逻辑推理能够反映自然语言要素信息传递特性. 通过抽象有效重组参数提炼if-then模糊逻辑推理规则、根据精馏分离序列综合问题数字特征创建Sugeno模糊逻辑推理模型,系统化地提出了基于模糊逻辑推理的精馏分离序列优化综合方法.     

油页岩热解煤气粗苯精制的分离序列研究

为提高从油页岩热解煤气中回收的粗苯产品的经济效益,研究了对回收的粗苯进行精制的分离序列,模拟常规精馏序列和热耦合精馏序列分离粗苯的过程并计算其能耗和热力学效率.结果表明,在轻组分含量较高的粗苯精制分离序列中,完全热耦合精馏序列仍然具有较好的节能效果.其能耗比常规精馏序列中能耗最小的直接分离序列节能约35％,热力学效应也由7.4％提高到11.6％.     

基于非关键组分的精馏序列和反应参数优化

多个精馏序列可用于分离多组分混合物,其能耗和投资费用均与其非关键组分总流量正相关,可据此辨识最优精馏序列。考虑反应器对精馏序列的影响,系统推导了反应器原料、操作参数和反应器流出物的关系,探究各组分在精馏序列作为非关键组分存在的规律,提出以非关键组分矩阵表征不同精馏序列和据此辨识最优精馏序列的方法。案例分析表明所提出的方法可简单、准确地确定分离不同组分数的混合物的非关键组分矩阵、边际气相流率和最优精馏序列。     

隔壁塔分离乙醇-正丙醇-正丁醇体系

以乙醇-正丙醇-正丁醇为分离体系,研究回流比、气液分配比等操作参数对隔壁塔分离效果的影响。将常规双塔精馏序列转化为隔壁精馏序列并保证各操作参数的最优值,利用Aspen Plus模拟软件对乙醇-正丙醇-正丁醇三组元的常规精馏序列和隔壁塔精馏序列进行模拟分析,探究隔壁精馏工艺最佳操作区域及节能效果,模拟结果表明,在满足分离要求下,气液分配比存在一个相互关联关系,使隔壁塔精馏序列存在一个再沸器热负荷最小的最佳操作区域。与常规精馏序列相比,完成相同的分离任务,隔壁塔精馏序列再沸器节能6 954.368 k W,冷凝器热负荷减少2 934.291 k W。结果表明,隔壁塔精馏序列不但提高了热力学效率、降低了能耗,并且大幅降低设备投资。     

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。     

设计演化算法实现精馏分离序列优化综合

采用演化算法求解具有组合爆炸特征的精馏分离序列优化综合问题。由于精馏分离序列与二叉树之问具有同构性．在数据结构上精馏分离序列可以抽象为二又树,直接采用二叉树结构编码方案可以同时表达个体的基因型和表现形。借鉴生物界父本可以经过有性繁殖或无性繁殖得到子代的现象。对遗传算子进行设计。应冒图论方法建立有效的二叉树结构演化重组机制,从而形成基于双亲或单亲父本的交叉算子。实例表明：双亲遗传操作其空间搜索率较低,而单亲遗传操作其最优解命中率较高。因此。演化算法能够成功解算大规模精馏分离序列优化综合问题。     

Bicontinuous porous membranes with micro-nano composite structure using a facile atomization-assisted nonsolvent induced phase separation method

The micro-nano composite structure can endow separation membranes with special surface properties, but it often has the problems of inefficient preparation process and poor structural stability. In this work, a novel atomization-assisted nonsolvent induced phase separation method, which is also highly efficient and very simple, has been developed. By using this method, a bicontinuous porous microfiltration membrane with robust micro-nano composite structure was obtained via commercially available polymers of polyacrylonitrile and polyvinylpyrrolidone. The formation mechanism of the micro-nano composite structure was proposed. The microphase separation of polyacrylonitrile and polyvinylpyrrolidone components during the atomization pretreatment process and the hydrogen bonding between polyacrylonitrile and polyvinylpyrrolidone molecules should have resulted in the nano-protrusions on the membrane skeleton. The membrane exhibits superhydrophilicity in air and superoleophobicity underwater. The membrane can separate both surfactant-free and surfactant-stabilized oil-in-water emulsions with high separation efficiency and permeation flux. With excellent antifouling property and robust microstructure, the membrane can easily be recycled for long-term separation. Furthermore, the scale-up verification from laboratory preparation to continuous production has been achieved. The simple, efficient, cost-effective preparation method and excellent membrane properties indicate the great potential of the developed membranes in practical applications.     

In search of the ideal protein sequence

The inverse of a folding problem is to find the ideal sequencethat folds into a particular protein structure. This problemhas been addressed using the topology fingerprintbased threadingalgorithm, capable of calculating a score (energy) of an arbitrarysequence-structure pair. At first, the search is conducted byunconstrained minimization of the energy in sequence space.It is shown that using energy as the only design criterion leadsto spurious solutions with incorrect amino acid composition.The problem lies in the general features of the protein energysurface as a function of both structure and sequence. The proposedsolution is to design the sequence by maximizing the differencebetween its energy in the desired structure and in other knownprotein structures. Depending on the size of the database ofstructures ‘to avoid’, sequences bearing significantsimilarity to the native sequence of the target protein areobtained using this procedure.     

用于废水处理的新型光催化膜反应器研究进展

是目前世界相关领域研究的热点.从不同类型光催化膜反应器的组器结构和运行方式着手,并结合课题组具体试验进展,分析了影响光催化膜反应器性能的结构和影响因素,如光源、膜材料,光催化剂和目标降解物含量,溶液pH,以及曝气,膜面流速等.由光催化和膜分离技术组合而成的新型光催化膜反应器,不仅具有其各自优点,可以有效解决废水处理中纳米催化剂粒子难分离回收的难题,同时还可产生耦合增强效应,大大提高有机废水处理的效率.认为应有效地将改性催化荆与膜分离技术耦合,针对实际废水体系的光催化降解开展研究.     

Studies in process synthesis—I: Branch and bound strategy with list techniques for the synthesis of separation schemes

The synthesis of a good flowsheet for a multicomponent separation problem constitutes a formidable task even for a small scale problem. The number of alternate, feasible separator sequences increases rapidly as the number of components in the mixture and the number of allowed separation methods increase. Some methods to select a sequence are almost purely heuristic to permit rapid screening among the alternatives without a guarantee of optimality. Another is based on dynamic programming and for special problems can in principle locate the best sequence, but it is notably time consuming.This paper uses primal and dual bounds in a branch and bound strategy to develop a procedure for locating a small number of nearly optimal separation sequences; furthermore, the optimal sequence must be among those found. Restrictions necessary for the dynamic programming approach can be relaxed (serial structure, high product purity), and in principle the method should generally be significantly faster.Two examples illustrate the approach.     

基于随机优化的热耦合复杂精馏系统的综合(Ⅰ)模型化方法

基于随机型最优化策略,针对包含简单塔、带有侧线蒸出及侧线汽提塔的复杂塔、全热耦合（或Petlyuk）塔的热耦合复杂精馏塔系统的综合问题,提出一种模型化方法.针对热耦合复杂精馏流程系统所需塔段数目以及冷凝器和再沸器数目的不确定性,提出了一种分解求解策略,将原问题分解成一系列具有不同塔段数的子问题分别求解;针对流程结构的优化提出一种流程结构的编码表达法,该方法将问题的分离序列结构和热耦合方式分别用两组编码表示,对分离序列的编码采用了数据结构理论中的二叉树排序方法,使流程结构的描述变得更加简便;最后以预分馏塔组分回收率及回流比为连续变量,建立了热耦合复杂精馏系统优化的[JP+1]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.     

Finding the thermodynamically optimal separation sequence for multicomponent mixtures and the optimum distribution of the heat- and mass-transfer surface areas

The problem of the separation sequence minimizing the energy consumption at a given process capacity for multicomponent mixtures and the problem of the optimal contact area distribution among the separation stages are considered. For thermal separation systems, whose capacity is limited, the dependence of the maximum possible capacity on the separation sequence is analyzed.