一类非线性系统的变负荷预测控制

生产过程的变负荷运行使得其非线性动态特性的影响凸显。针对变负荷生产过程中机理模型为常微分方程或半显式Heisenberg微分-代数方程的一类非线性动态系统,采用非线性预测控制算法,构造出稳态优化与动态优化的两层控制结构,并采用联立法进行优化数值求解。最后对化工过程的夹套CSTR进行仿真验证,表明该算法的有效性。     

氧化铝蒸发的动态过程建模与仿真

基于物料平衡原理和热量平衡原理,分析蒸发器出口料液浓度与进口料液和蒸汽之间的动态变化,建立了四效逆流降膜蒸发加三级闪蒸的氧化铝蒸发过程时滞动态数学模型和蒸发单元状态空间模型.通过模型计算和仿真验证了模型的有效性,与氧化铝蒸发过程实际测量值相比较,证明了模型能够很好地反映氧化铝蒸发的动态生产过程,为优化控制系统设计奠定了...     

运用概念和层次分析法对煤化工系统蒸汽平衡方案的优化设计

在煤化工系统的蒸汽平衡方案设计中引人(?)概念,对工艺气、蒸汽和水的有效热能进行能级品位的梯级分类,根据热能的不同(?)值,按"层次分析法"分层次对供与需两两对比、逐级利用。提出的"动态分析法"用于分析处理和优化解决复杂的工艺动态过程,进行最大限度的优化。举例说明了综合运用(?)概念、"层次分析法"及"动态分析法"与常规设计对比,在蒸汽平衡中对煤化工系统所产生的显著的节能效果。     

预焙阳极生产过程动态优化

预焙阳极是影响铝电解生产成本中最主要的因素之一,降低生产成本是每一个铝电解厂持续追求的目标。在生阳极生产车间进行动态过程优化(Dynamic Process Optimization,DPO)是生产系统的一个重要组成部分,过程优化的主要目标是预焙阳极在电解槽中具有相同的使用性能前提下生产成     

联碱生产水平衡探讨

介绍了联碱系统工艺指标与物料之间的关系。通过对联碱生产过程的攻关查定,明确了联碱装置的关键设备经过技术改造、工艺指标不断优化,使联碱现装置能够稳定生产,而且在生产轻质纯碱和生产低盐纯碱时,系统的料液能做到平衡。     

关于DB油田长6油藏开发调整技术政策研究

油田开发的过程实际是一个动态优化过程,通常会采用一些技术措施或政策调整对该系统进行控制和优化,达到“实时平衡”。调整过程中除了对油藏实施一些控制外,需要考虑油田开发层系的划分与组合是否合理,井网形式及井网密度及井距是否合理,压力和温度系统是否和现有压裂工艺契合,注采比、单井注水量、单井产能、合理采油速度等是否符合当下的采油参数。     

带式输送机多机拖动功率平衡问题的探讨

针对煤矿开采中较多使用到的带式输送机进行研究,对多机拖动带式输送机实际工作时的功率平衡静态和动态影响因素进行分析,在此基础上提出了实际工程中可以使用的优化方案。同时对CST功率平衡过程进行分析,对实际测得的数据进行研究,最终得到功率平衡动态和静态因素对输送机的影响以及优化方案。     

离子膜法烧碱装置氯、氢平衡的解析

液氯销售困难时,液氯库存告急。生产系统氯、氢不能够平衡,过量的氯气须要液化或充钢瓶来平衡生产,以免影响生产稳定运行。经跟踪分析,发现变压吸附提纯装置200#提氢排二次尾气含氢量较高,氢气回收率低,须要进一步优化和改造。针对生产过程中存在的氯氢配比不平衡问题,提出合理化建议。     

化工燃料气生产平衡与优化

分析广州石化化工燃料气管网状况及存在的问题,阐述化工燃料气平衡思路和多项优化措施,通过生产调度平衡,对化工燃料气管网进行实时监控和动态调整优化,加强燃料气回收管理,优化资源配置降低运行成本,提高了燃料气管网的运行稳定性,避免出现不平衡发生排放火炬情况,达到节能减排、提高经济效益目的。     

CO2汽提法尿素生产过程水平衡

系统介绍C02尿素生产过程中水平衡数据,也给出了氨汽提法尿素生产过程中的水平衡数据,并根据水平衡图及物料含水量,指出生产过程中水平衡的关键及其控制.     

Modeling,Control, and Optimization of Ideal Internal Thermally Coupled Distillation Columns

Internal Thermally Coupled Distillation Columns (ITCDIC) are the frontier of energy saving distillation research. In this paper, the ideal ITCDIC is considered. A novel mathematical model and a related simulation algorithm are proposed. The dynamic responses of open‐loop, PID controllers and the responses of closed‐loops are carried out. The results show that the ITCDIC is a self‐balance process and could be operated smoothly with two PID controllers; the steady‐state optimization met the need of ITCDIC optimization. Furthermore, a steady‐state optimization model of the operation parameters is presented, which can be used to directly obtain the optimal operation parameters simultaneously guaranteeing not only the product quality and the maximum energy savings but also the dynamic operability and controllability. The benzene‐toluene system is studied as an illustrative example.     

PTFE间歇聚合反应过程变周期动态经济优化控制

聚四氟乙烯(PTFE)间歇聚合生产模式可满足小批量、多用途以及高质量产品的市场需求。针对PTFE聚合过程存在强非线性和大时滞特性,提出了一种基于自由终端的动态经济优化控制方法。首先,将生产周期作为一个自由度纳入优化变量建立动态经济优化问题,采用改进控制变量参数化方法,控制输入被离散为可变长度的片状序列,便可将动态经济优化问题转换为非线性规划(NLP)问题;然后,采用基于梯度下降的内点罚函数法求解NLP问题,通过变周期预测时域的滚动优化控制方法优化控制输入和终端时间;最后将提出的变周期动态经济优化控制与传统PI控制、非线性模型预测控制进行对比测试分析,仿真结果表明本方法单位经济效益更高,生产周期更短,突显了间歇生产的灵活性。     

PTFE间歇聚合反应过程变周期动态经济优化控制

聚四氟乙烯(PTFE)间歇聚合生产模式可满足小批量、多用途以及高质量产品的市场需求。针对PTFE聚合过程存在强非线性和大时滞特性,提出了一种基于自由终端的动态经济优化控制方法。首先,将生产周期作为一个自由度纳入优化变量建立动态经济优化问题,采用改进控制变量参数化方法,控制输入被离散为可变长度的片状序列,便可将动态经济优化问题转换为非线性规划(NLP)问题;然后,采用基于梯度下降的内点罚函数法求解NLP问题,通过变周期预测时域的滚动优化控制方法优化控制输入和终端时间;最后将提出的变周期动态经济优化控制与传统PI控制、非线性模型预测控制进行对比测试分析,仿真结果表明本方法单位经济效益更高,生产周期更短,突显了间歇生产的灵活性。     

木浆制备钻井液用低黏羧甲基纤维素钠盐

低黏羧甲基纤维素钠盐是一种优异的降滤失剂,国内大多以精制棉为原料、选用溶媒法工艺生产该产品。本文选用造纸木浆为原料,采用工艺简单的水媒法制备钻井液用低黏羧甲基纤维素钠盐。通过纤维浆的优选、醚化剂制备工艺的确定、设计取代度的确定、水量的确定以及降解剂用量的确定,进行工艺条件调整,最终确定了产品的配方。     

Process Parameters Optimization for Energy Saving in Paper Machine Dryer Section

Due to high energy consumption in the Chinese paper industry, this study considers higher-energy efficiency for the multicylinder dryer section of paper machines. A common situation in the Chinese paper industry is that energy is consumed in extensive mode. In order to improve the energy efficiency of the paper machine dryer section, deeper analysis and optimization of process parameters are necessary.

A NLP optimization method is developed for integration of steam system and air system to reduce the steam consumption and decrease the loads of centrifugal blowers in the multicylinder dryer section of a paper machine. Equality constraints of the optimization model are extracted from different process modules based on material and energy balance. Inequality constraints are from the production capacity, operating condition, etc. Two illustrative examples are presented in this paper. The results show that the optimization model is adaptive and convenient for application. For a newsprint machine, less dry air and steam are used and the energy consumption can be reduced by about 8% in the dryer section. Applied on a linerboard machine which has surface sizing, the method can reduce the energy consumption by 5.6%.     

石化企业能源管理系统的研发与应用

石化工业在为经济发展提供物质支撑的同时, 也消耗着大量的能源。石化企业节能降耗的潜力很大, 信息技术在节能降耗方面前景广阔。在对石化企业能源管理业务范围、介质、管理维度进行分析的基础上, 进行了系统的功能设计, 描述了工厂模型, 按照用能优化、管网优化与动力优化3方面刻画了能源优化模型。最后, 从试点企业的应用成效出发, 为石化企业推进能源管理信息化建设提供了借鉴和参考。     

Fast Monte Carlo methodology for multivariate particulate systems—I: Point ensemble Monte Carlo

A fast Monte Carlo methodology for particulate processes is introduced. The proposed methodology combines concepts from discrete population balance equations and dynamic Monte Carlo simulations of chemical kinetics to construct a new jump Markov model that approximates the population balance dynamics. The Markov model consists of a definition of a new type of reaction channel, in which the reaction product is a stochastic process by itself. One feature of this model is that, although a coarse view of the process is taken, it still conserves the history of individual particles. This is a very important aspect for effective modeling of multivariate models, especially when part of the goal is to study the evolution of the internal states of the particles (i.e., composition, phase behavior, etc.).Numerical experiments show that this algorithm can improve the computational load of the exact method by orders of magnitude without sacrificing computational accuracy. The methodology is useful especially in stochastic optimization applications where many function calls (simulations) are required. Possible applications are optimization and dynamic optimization using an artificial chemical process algorithm, genetic algorithm, or simulated annealing among others.     

基于自适应采样算法的芳烃异构化代理模型

异构化是芳烃生产中的重要环节,提高异构化环节的建模和优化效率对工业生产有着重要意义。但是,直接使用机理模型的优化过程耗时较长,优化效率低。代理模型可以有效地对机理模型进行近似,而代理模型采样方法对模型精度有很大影响。提出了一种新的基于稀疏度和最邻近期望的自适应采样算法,该方法可以平衡全局搜索和局部搜索,通过求解优化问题找到反映函数关键信息的新采样点,再加入原始样本集中,使得代理模型精度不断提高。多个测试函数结果表明,相比于其他自适应采样算法,该算法能有效提升代理模型精度和建模效率。该算法在芳烃异构化环节代理模型中也得到了有效验证,与本文中其他算法对比,该算法模型误差减少5%以上,建模时间缩短30%以上。     

Dynamic modeling of an industrial diesel hydroprocessing plant by the method of continuous lumping

Diesel hydroprocessing is an important refinery process which consists of hydrodesulfurization to remove the undesired sulfur from the oil feedstock followed by hydrocracking and fractionation to obtain diesel with desired properties. Due to the new emission standards to improve the air quality, there is an increasing demand for the production of ultra low sulfur diesel fuel. This paper is addressing the development of a reliable dynamic process model which can be used for real-time optimization and control purposes to improve the process conditions of existing plants to meet the low-sulfur demand. The overall plant model consists of a hydrodesulfurization (HDS) model for the first two reactor beds followed by a hydrocracking (HC) model for the last cracking bed. The models are dynamic, non-isothermal, pseudo-homogeneous plug flow reactor models. Reaction kinetics are modeled using the method of continuous lumping which treats the reaction medium as a continuum of species whose reactivities depend on the true boiling point of the mixture. The key modeling parameters are estimated using industrial data. Steady-state and dynamic model predictions of the reactor bed temperatures, sulfur removal, and diesel production match closely the plant data.