遗传算法在过程综合混合整数非线性规划中的应用

针对过程综合混合整数非线性规划问题提出了一种混合遗传算法，该算法对整数变量进行编码，而对连续变量则采用连续化遗传算子进行处理，使得算法与原问题的对应更加自然，也更有效。另外，还针对常见的提前收敛或局部最小现象提出几种算子，实例表明本算法具有较强的全局优化能力。相对于传统遗传算法具有速度快、精度高、可操作性强等特点。     

基于超结构法的热集成间接式功交换网络综合

换热网络综合的研究和应用对于提高能源利用率已被证明是有效的,而用于回收更高品质能量的功交换网络综合的研究仍处于起步阶段。针对间接式功交换网络综合中复杂推动力约束对流股匹配的制约问题,构建了一种考虑级间热集成的拓展超结构,基于线性拟合压缩机和涡轮机的操作曲线,提出了功源与功阱间流股匹配的识别方法;针对压力、流量与温度的高度非凸非线性关系,提出了采用热集成优化每一级入口温度的松弛策略,建立了以年度总费用最小为目标的混合整数非线性规划模型,通过GAMS求解得到最优的间接式功交换网络结构。最后通过一个算例分析,验证所提方法的有效性和可行性。     

抗生素发酵过程优化调度模型的研究

对抗生素多罐并行发酵过程进行了分析,将任务、设备和事件之间的分配关系表达为两类0-1变量,建立了一个基于连续时间的抗生素多罐并行发酵过程优化调度的M ILP(混合整数线性规划)模型。该模型整数变量少,求解速度快,并给出了最短生产时间和罐批最优生产序列。最后以头孢菌素发酵过程为例证明了此调度模型的可行性和有效性。     

工业系统超结构模型应用研究进展

超结构模型的研究和应用可以有效解决化工、水处理、钢铁、冶金等领域中逐渐凸显的能源效率问题,常见于工业系统中的热交换网络和质量交换网络、水网以及其他网络。详细论述了换热网络中的基于状态空间超结构、基于分级超结构模型,以及两种经典超结构模型思想在质量交换网络、水网中的应用。完成超结构构建后,根据工业的实际生产状况,一般以年度总费用为目标函数,选取合理算法优化超结构网络,最终得到所需的新建或者改建方案。总结归纳了常见的优化算法,主要分为两大类:确定性算法和随机算法。最后阐述了超结构模型在科学研究和实际工程应用中还存在的问题以及下一步的研究方向。     

炼油厂氢气分配系统超结构优化方法研究进展

炼油厂氢气分配系统超结构优化方法自2001年提出以来,作为节能降耗、降本挖潜的理论方法获得长足进步。文章对相关研究成果进行比较系统的评述,并介绍了现有的工具软件。     

过程全局夹点分析与超结构MINLP相结合的能量集成最优综合法

提出了过程全局夹点分析与超结构混合整数非线性规划 (MINLP)相结合的能量集成最优综合法 .各单过程内部换热优化匹配后 ,进行各过程剩余冷、热负荷与公用工程系统的全局夹点分析 ,确定全局热集成目标 ,在此基础上建立包含过程剩余热负荷产生各等级蒸汽、剩余冷负荷使用各等级蒸汽加热的各种可能匹配方案的公用工程换热网络超结构及其MINLP模型 ,采用混合连续进化算法求解得到过程与公用工程换热网络最优改造方案 .大型乙烯装置能量集成应用算例表明 ,可充分发挥全局夹点分析法确定改造目标的简洁实用性和超结构MINLP寻求最佳方案的优点     

混合整数非线性规划法求解多组分复杂体系相平衡问题

基于Gibbs自由能最小化原理,提出一种求解多组分复杂体系相平衡问题的混合整数非线性规划(MlNLP)方法.通过建立MlNLP模型,将相平衡计算问题转化为有约束的双层最优化问题,内层用来计算给定相组合结构下的平衡组成,外层则是搜索最优的相组合结构,整个求解过程通过遗传算法来实现.所建立的方法只需要求解最小化问题,就可以同时给出多相平衡时存在的相数、相态及各相组成.以苯-乙氰-水和甲醇合成两个体系的相平衡计算为例,结果表明该方法是可行和有效的.     

基于逻辑与启发性知识的MINLP过程综合方法

提出了一种系统化的基于逻辑与启发性知识的MINLP过程优化综合方法 .该方法将超结构图的拓扑结构分解成特定的几种设备连接类型 ,通过组合形成基于逻辑的混合整数规划模型 ,克服了数学规划法在建模方面所存在的不直观、难于系统化地实现、复杂的超结构模型难于建立等缺点 .模型中还以硬逻辑或启发的形式引入工程经验 ,减小了搜索空间 ,加快了求解速度 .通过化工厂公用工程系统综合的实例 ,将本方法与传统的层次分解法、数学规划法进行了比较 ,证明了其实用性和优越性     

过程系统能量流结构模型及其应用

综述了过程系统能量综合优化的能量流结构研究与进展；重点介绍了过程系统三环节能量流结构模型，该模型基于对过程系统中能量演变共性规律的认识，定量地描述了过程系统能量流在转换、利用、回收过程中的平衡关系；概述了按照能量流结构进行过程能量综合优化策略和方法；指出了过程系统能量综合优化中能量流结构的进一步发展可以包容其他相关方面，如环境、安全等。     

清洁过程综合的简化模型和求解

建立了过程经济和环境的简捷多目标混合整数非线性规划(MOMINLP)模型,以组合多目标加权法和外逼近等式松弛法为求解策略,应用GAMS编程实现MOMINLP问题的求解,以甲苯加氢脱烷基化(HDA)过程为案例进行分析.     

Global superstructure optimization for the design of integrated process water networks

We propose a general superstructure and a model for the global optimization for integrated process water networks. The superstructure consists of multiple sources of water, water‐using processes, wastewater treatment, and pre‐treatment operations. Unique features are that all feasible interconnections are considered between them and multiple sources of water can be used. The proposed model is formulated as a nonlinear programing (NLP) and as a mixed integer nonlinear programing (MINLP) problem for the case when 0–1 variables are included for the cost of piping and to establish optimal trade‐offs between cost and network complexity. To effectively solve the NLP and MINLP models to global optimality we propose tight bounds on the variables, which are expressed as general equations. We also incorporate the cut proposed by Karuppiah and Grossmann to significantly improve the strength of the lower bound for the global optimum. The proposed model is tested on several examples. © 2010 American Institute of Chemical Engineers AIChE J, 2011     

Sustainable biopolymer synthesis via superstructure and multiobjective optimization

Sustainable polymers derived from biomass have great potential to replace petrochemical based polymers and fulfill the ever‐increasing market demand. To facilitate their industrialization, in this research, a comprehensive superstructure reaction network comprising a large number of reaction pathways from biomass to both commercialized and newly proposed polymers is constructed. To consider economic performance and environmental impact simultaneously, both process profit and green chemistry metrics are embedded into the multiobjective optimization framework, and MINLP is used to enable the effective selection of promising biopolymer candidates. Through this proposed approach, this study identifies the best biopolymer candidates and their most profitable and environmentally friendly synthesis routes under different scenarios. Moreover, the stability of optimization results regarding the price of raw materials and polymers and the effect of process scale on the investment cost are discussed in detail. These results, therefore, pave the way for future research on the production of sustainable biopolymers. © 2017 American Institute of Chemical Engineers AIChE J, 63: 91–103, 2018     

Optimal design of reverse osmosis‐based water treatment systems

We address the problem of optimal design of reverse osmosis (RO)‐based water treatment systems. A superstructure optimization method is proposed to solve the problem, where the superstructure for a RO system is structurally enhanced with additional features. We formulate the problem as mixed‐integer nonlinear program which is solved to yield optimal results. A case study on desalination is considered in this work, and the numerical results obtained using our approach are validated using a commercial simulation tool. We further extend the problem by considering the effects of degradation of membrane performance over time and solve it by representing the problem as a two‐stage stochastic program. This new approach is highly useful for identifying minimum cost robust designs for membrane‐based water purification systems, which are especially important in desalination applications. © 2012 American Institute of Chemical Engineers AIChE J, 2012     

用于超结构换热器网络热计算和网络综合的显式解

For the optimal design of a heat exchanger network, the inlet and outlet stream temperatures of each heat exchanger in the network should be known. An explicit analytical solution of stream temperatures of an arbitrary connected heat exchanger network was introduced, which is suitable for the thermal calculation of heat exchanger networks. For the heat exchanger network synthesis, this solution was further developed and coupled with the stage-wise superstructure heat exchanger networks. The new calculation procedure reduced the computer memory requirement dramatically. On the basis of this solution, a mathematical model for synthesis of heat exchanger networks with genetic algorithm was formulated, which is always feasible and no iteration is needed. Two examples were calculated with the proposed approach and better results were obtained.     

基于状态空间超级结构的多流股换热网络最优设计

多流股换热器以其结构紧凑、高效低耗等特点,成为过程强化研究的热门领域,但对于多流股换热的过程与设备优势所在仍然值得商榷。基于多流股换热匹配改进状态空间超级结构,将多流股换热网络综合转化为超级换热器设计。首先,构造级联多流股换热器匹配过程操作算子,通过相邻换热流股匹配,传递温位效应,实现多流股间传热严格计算;借助热容流率混合分配机制,实现各流股间任意分混操作。然后,考虑散热因素,改进目标函数,引入冷热损失和保温材料费用项,清晰体现多流股换热器因换热面互相覆盖而带来的外表面封包优势。进而,建立相应非线性数学规划模型,实现公用工程、设备投资、冷热损耗同步优化。最终,通过文献示例对所提方法可行性与优越性进行验证。     

一种对预测控制系统经济性能评估的实用方法及其工业应用

In this article, an approach for economic performance assessment of model predictive control (MPC) system is presented. The method builds on steady-state economic optimization techniques and uses the linear quadratic Gaussian (LQG) benchmark other than conventional minimum variance control (MVC) to estimate the potential of reduction in variance. The LQG control is a more practical performance benchmark compared to MVC for performance assessment since it considers input variance and output variance, and it thus provides a desired basis for determining the theoretical maximum economic benefit potential arising from variability reduction. Combining the LQG benchmark directly with benefit potential of MPC control system, both the economic benefit and the op-timal operation condition can be obtained by solving the economic optimization problem. The proposed algorithm is illustrated by simulated example as well as application to economic performance assessment of an industrial model predictive control system.     

电解质NRTL模型的研究进展及应用

电解质NRTL模型是重要的热力学局部组成模型。本文阐述了电解质NRTL模型的研究进展过程,包括模型的提出、修正、改进和扩展,同时指出了不同模型的适用范围。介绍了模型在各种复杂电解质溶液体系关联计算中的应用,可以为一些工业生产过程的模拟、设计和优化提供理论指导。电解质NRTL模型的主要优势是适用的温度和浓度范围宽,不需二元以上高阶参数;但模型自身也存在缺陷,如参数的回归工作量大、在溶液体系临界点处的预测精度较差等,故模型仍需进一步完善。     

换热器网络同步最优综合方法──改进的MINLP转运模型法

针对现有的换热器网络最优综合方法的局限性，采用分级超结构转运模型和物流吸、放热潜力的概念，提出了非等温混合线性约束的换热器网络同步最优综合混合整数非线性规划（MINLP）的改进模型．该模型不仅可以对公用工程费用、换热面积、换热设备台数及物流的匹配选择进行多目标同步优化，而且在线性约束的条件下消除了等温混合的不合理假设，只需求解一次MINLP问题就可得到包括分流情况在内的最优网络结构．算例表明，该模型优于以往的几种同步优化模型．     

加氢裂化反应动力学模型研究及应用进展

加氢裂化技术在石化行业中的地位已举足轻重。为深入了解加氢裂化反应规律、优化工业装置运行工艺条件和产品分布,实现炼化企业智能化和效益最大化的目标,科研人员对加氢裂化反应动力学模型做了广泛的研究。对加氢裂化反应动力学模型相关研究及应用进展做了综述,介绍了加氢裂化反应动力学模型研究历程,研究目标从初期简易宏观的关联模型发展为按馏程或其他生产方案需求划分的传统、连续集总模型,再进一步发展为复杂微观的分子集总模型;概述了不同加氢裂化反应动力学模型的应用情况,突出说明了传统集总模型的工业实用性和分子集总模型原料、产品适用性;指出有效地将关联、集总模型（尤其是分子集总）结合利用,开发一种全面的混合动力学模型,将是未来加氢裂化以及其他石油加工过程反应动力学模型研究中极具意义和挑战的工作。