原油蒸馏塔的模拟计算

在深入研究石油馏分虚拟组分切割方法的基础上，按照原油常压蒸馏塔的工艺原理，提出了联合使用BP法和SR法，以功能模块组合的流程模拟法求解原油常压蒸馏塔的新途径。它具有收敛性好、计算精度高等特点，为进一步实现原油常压蒸馏塔的优化和炼油厂全流程的模拟与优化奠定了基础。     

合成氨变换工段饱和热水循环系统的优化方法研究

本文将不可行路径法推广到复杂模块中,提出了一种新的不可行路径法,该法与现有不可行路径法的区别在于:在每轮优化迭代计算中,不要求复杂模块的模拟收敛.本文还对初值及标度因子的选取进行了讨论,提出了相应的选取原则.通过对合成氨变换工段循环热水系统以饱和塔出口半水煤气温度最大为目标函数进行优化计算,证明本文方法是成功的.     

基于SQP的中药生产双效浓缩过程优化

针对中药生产双效浓缩过程动态平衡及蒸发速度优化问题,采用了基于SQP的优化与序贯模块模拟相结合的不可行路径求解方法.实践结果表明,将以SQP为优化核心的不可行路径法求解的优化结果应用在中药生产浓缩过程的自动控制中,能使中药生产过程始终维持双效动态平衡,且蒸发快速和稳定.     

φ600提温型轴——径向氨合成塔操作工艺参数的优化计算

本文应用不可行路径法,对φ600提温型轴—径向混合成塔的工作工艺参数,以年氨产量为目标函数,进行了优化计算,得到了最佳操作工艺参数。优化计算结果对φ600提温型轴—径向氨合成塔的实际操作具有指导意义。     

原油蒸馏塔汽液负荷软仪表的开发及应用

开发了原油蒸馏塔内部汽液负荷软测量的通用软件，在软件的开发过程中，重点考虑了原油蒸馏塔的一般性特点和工程实用性，并采用了模块化结构，因而所开发的软仪表对这一类塔的计算具有很大的通用性和可移植性，该软件已在一个复杂的常压塔上进行了实施，在线结果满足工业控制的要求。     

优化技术在原油管输调度中的应用

以甬沪宁原油管网为例,说明调度优化系统将数学规划模型和仿真模型2种调度方法完美结合,首先采用数学规划模型计算出最优解或可行的满意解,然后将结果导入仿真模型进行模拟,修正数学模型近似或忽略的因素.主要描述混合整数线性规划技术以及仿真技术在原油管输调度中的应用及应用的初步效果.     

反应路径综合的双层优化法

在简单计量系数反应方程的基础上,对复杂反应路径综合问题提出了双层优化法. 第一步找出经济上最优的若干总反应方程式,第二步对总反应进行分解,得出热力学可行的最优分反应. 实例分析结果表明该法能够有效地解决实际过程的反应路径综合问题.     

建立原油塔内回流动态模型

讨论了原油蒸馏塔内液相回流的动态计算方法。在一些合理假设的基础上,将原油塔集结成若干塔段,获取了低阶动态内回流模型。该模型在塔处于非平稳过渡状态时仍能较好地反映塔内的实际变化情况,克服了完全静态衡算方法的缺陷,在实际生产过程控制中的应用也取得了良好的效果。     

低压脱甲烷系统优化分析

在对低压脱甲烷系统进行计算机模拟的基础上，建立了以系统乙烯损失与能耗之和为目标函数的最优化数学模型；采用可行路径序贯模块法为最优化计算策略，结合广义既约梯度法对该系统实施优化计算，找出了对系统目标函数影响较大的可调决策变量及其最优化条件．对优化决策变量的选择及中等规模化工系统的优化策略进行了有益的探索．     

能量集成蒸馏塔系列的合成

本文分两阶段合成最优热集成蒸馏塔网络:首先优化设计变量使一切可能的热集成产生最大的增益,然后通过合成热集成树在分离顺序空间中找出最小分离成本顺序.由于可行的换热塔对数目不多,而且采用了简捷方法确定最优蒸馏压力,大大减轻了计算量.以一个很通行的例子演示了合成过程.对不同方法合成结果的比较表明新方法对于能量和分离成本均实现了更大幅度的节省.     

基于特征选择的常减压装置模型及在计划优化中的应用

常减压装置将原油切割为不同中间产品,其作为炼油工艺的龙头装置,对炼油过程生产计划排产与效益提升至关重要。通过建立一种高精度且具有良好求解效率的常减压模型,用以求解模型关键指标实沸点（TBP）曲线,即综合考虑切割产品的实沸点（TBP）与原油TBP、流量、温度等变量影响,构建非线性方程组模型来表征输入输出间的关系;利用特征选择方法遴选相关变量（包括进料性质、相邻TBP及其二次项等）,并采用鲸鱼优化算法优化方程组系数。仿真结果表明,该多输出相互关系模型与已有文献工作相比,在兼顾求解效率基础上,常减压装置各蒸馏切割产品TBP曲线预测上有更高的精度,将此模型应用到炼厂计划优化中,与传统的悬摆切割模型对比,优化结果优于传统悬摆切割模型。     

Improved infeasible path optimization for sequential modular simulators—I: The interface

Recently, it was shown that chemical processes modeled by steady-state simulators could be optimized without repeatedly converging the process simulation. Instead, optimization and simulation of the process can be performed simultaneously (along an infeasible path), thus leading to much more efficient performance. In this two-part study, several improvements to this infeasible path approach are described. This first paper deals with improvements to the interface between the optimization algorithm and the process simulator. Here one is primarily concerned with obtaining the necessary function and gradient information for the optimization with minimum computational effort from the process simulator. The architecture of sequential modular simulators, the structure of process optimization problems and any sources of error in obtaining the necessary gradient information for the optimization algorithm are considered. To this end, a chainruling algorithm is derived that allows the incorporation of analytic derivative information for parts of the flowsheet and generally leads to less frequent evaluation of the flowsheet modules. This algorithm is demonstrated on three process optimization problems. The results indicate significant improvement in performance.     

能量集成常减压系统的简捷模型及优化

针对常减压装置,提出基于Fenske-Underwood-Gilliland方程和焓衡算的简捷模型对现有的常减压系统复杂塔进行操作型计算和优化,并利用夹点分析确定系统的热回收目标。以常减压系统的年净利润最大为目标,同时考虑系统的产品收益和能量集成,建立了基于PSO随机粒子群算法的优化方法。以现有的常减压装置为算例,得到了年净利润最大条件下的各工艺参数。通过与严格模拟对比,表明常减压系统简捷模型能够得到较准确的计算结果。     

卡宾达原油常减压蒸馏装置负荷转移技术的模拟与分析

用ASPENPLUS软件对卡宾达原油常减压蒸馏装置进行了流程模拟计算，通过标定值和计算值的比较，验证了所建模型的可靠性，并通过分析找出负荷转移技术操作的关键因素。在此基础上对加工同种原油不同加工量操作条件进行优化与分析。     

Improved infeasible path optimization for sequential modular simulators—II: the optimization algorithm

Recently it was shown that chemical processes modeled by steady-state simulators could be optimzied without repeatedly converging the process simulation. Instead, optimization and simulation of the flowsheet can be performed simultaneously, along an infeasible path, thus leading to much more efficient performance.In this two-part study, we describe several improvements to this infeasible-path approach. This second article deals with theoretical and computational improvements to the optimization algorithm. Because recycle convergence and optimization occur simultaneously, the consequences of algorithmic failure can be severe, since little useful information is recoverable. Here we consider and improve several factors that affect the efficiency and robustness of the successive quadratic programming (SQP) optimization algorithm.The improvements are demonstrated on several small problems as well as on three chemical process problems. The results show significant improvement in performance as predicted from the theory.     

基于信赖域算法的精馏塔优化

从结构优化角度建立精馏塔优化的混合整数非线性规划(MINLP)模型,为了消除整数变量,引入绕流效率将MINLP问题转化为非线性规划(NLP)问题。针对得到的NLP问题提出一种优化方法,在该方法中采用结构优化中常用的信赖域优化算法进行求解,并应用虚拟瞬态连续性方程辅助优化中的稳态模拟。采用提出的优化方法对3个精馏系统进行设计优化,以不同初始值开始,均可得到令人满意的优化结果,表明所提优化方法具有良好的稳健性,对于较复杂的部分热耦合精馏过程仍然可以有效优化求解;信赖域算法在精馏塔优化中也表现出良好的收敛性。     

基于EGO算法的常压塔能量优化

常减压装置能量消耗约占炼厂总用能的25%～30%,在保证产品产量与质量的条件下,优化常减压蒸馏塔操作条件,可有效降低能耗.为了避免随机优化算法对常压塔机理模型进行操作优化时,存在计算资源消耗大、效率低的问题,文中采用基于代理模型的全局优化方法优化常压塔的余热回收过程,在优化迭代过程中用Kriging代理模型来代替耗时的精确模型评估.实验表明模型调用次数相较于粒子群优化算法减少了90%,优化时间减少了85%,实现了能量优化并且保证了侧线产品之间的分离精度.     

MODELING, SIMULATION AND CONTROL OF CRUDE TOWERS

Crude towers are one of the most energy consuming, complex distillation columns in a refinery. A mathematical model for the rigorous dynamic simulation of a crude tower is presented. Because of the large dimension, large stiffness and non-linearity of the model, dynamic simulation of a crude tower has proven to be very difficult. In this paper, the Sum of Rates algorithm is shown to be suitable for obtaining the steady states of a crude tower. Once a steady state is approached, the dynamic responses of a crude tower can be simulated by the Bubble Point algorithm. The dynamic simulation predicts strong, one-way interaction among the product streams. Through dynamic simulation, it is shown that the interaction can be eliminated by a decoupler.     

原油常减压蒸馏塔的流程模拟

常减压蒸馏装置是炼油加工的第一道工序,它的运行状况对后续装置乃至全厂都有着重要影响。针对初馏塔、常压蒸馏塔和减压蒸馏塔的稳态流程模拟,选取适合的蒸馏塔中段循环设定变量和减压塔模拟方法,最终流程模拟结果与实际工艺参数相似度极高,说明常减压蒸馏塔的流程模拟能够如实体现实际工艺状态,可以作为指导工艺生产、操作优化的有效方法。     

Optimization of crude distillation system using aspen plus: Effect of binary feed selection on grass-root design

With an objective to supplement guidelines available as general rules of thumb for the grass-root design of crude distillation unit (CDU) using binary crude mixtures, this work presents the optimization of crude distillation unit using commercial Aspen Plus software. The crude distillation unit constituted a pre-flash tower (PF), an atmospheric distillation unit (ADU) and a vacuum distillation unit (VDU). Optimization model constituted a rigorous simulation model supplemented with suitable objective functions with and without product flow rate constraints. Three different feed stocks namely Bombay crude, Araby crude and Nigeria crude were considered in this work along with various binary combinations of these crudes. The objective function considered was profit function (subjected to maximization) for cases without product flow rate constraints and raw-materials and energy cost (subjected to minimization) for cases with product flow rate constraints. Parametric study pertaining to feed selection and composition has been conducted in this work to further benefit refinery planning and scheduling. Simulation study inferred that the product flow rate constraints sensitively affect atmospheric distillation column diameter and crude feed flow rate calculations. Based on all simulation studies, a generalized inference confirms that it is difficult to judge upon the quality of the solutions obtained as far as their global optimality is concerned.