共查询到19条相似文献,搜索用时 74 毫秒
1.
ZW多产品间歇过程调度及在线调整 总被引:1,自引:1,他引:1
针对多产品间歇过程调度提出了分层递阶的Petri网建模方法,利用赋时Petri和Petri网的简化技术描述不同层次的生产问题,具有很强的模型描述能力。另外,在调度决策层可以方便地集成优化策略和在线调整算法,使问题求解更加灵活。 相似文献
2.
多效蒸发过程模拟与优化回顾 总被引:3,自引:0,他引:3
<正> 多效蒸发是节约蒸发过程所需生蒸汽的一个十分有效的手段。随着企业对蒸发节能的要求提高,多效蒸发系统大多采用了抽汽预热、冷凝水闪蒸、利用余热等节能措施。要对多效蒸发系统进行优化设计,就必须深入研究这一过程的模拟,了解其过去,发现不足从而予以完善。 一、多效蒸发过程模拟回顾 原则上讲,对多效蒸发过程的模拟问题,对各效分别应用质量衡算、热量衡算、传热速率和相平衡方程,联立即可得系统模拟的数学模型,求解这一模型即完成了模拟 相似文献
3.
4.
为了建立间歇工业过程的优化调度策略,研究了采用TPN(赋时Petri网)建立其生产调度模型的方法,并提出了基于GA(遗传算法)对此TPN调度模型进行优化的技术。论文引入了一个青霉素发酵间歇过程的仿真平台,以此为实例对象,讨论了TPN调度建模及GA优化的具体步骤,给出了满意的优化调度计算结果。 相似文献
5.
分析了广州石化多年采用的Aspen公司ORION系统进行生产调度排产中存在的不足,如未实现周计划从编制、执行到结果反馈的全过程痕迹管理,成品油调和排产仍为手工编制等。集成MES、LIMS、计划报表等系统信息建立生产调度与优化管理系统,完成从原油卸船、输送、中间贮存、加工的计划排产和计划跟踪情况管理,实现周计划制定、发布、执行、反馈闭环管理,优化原油调和、成品油调和,深化生产调度管理层的应用,进一步提升广州石化炼油生产管理水平,创造更高的经济效益。 相似文献
6.
不确定条件下的间歇生产调度优化是生产调度问题研究中具有挑战性的课题。提出了一种基于混合整数线性规划(MILP)的鲁棒优化模型,来优化不确定条件下的生产调度决策。考虑到生产过程中的操作成本和原料成本,建立了以净利润最大为调度目标的确定性数学模型。然后考虑需求、处理时间、市场价格三种不确定因素,建立可调整保守程度的鲁棒优化模型并转换成鲁棒对应模型。实例结果表明,鲁棒优化的间歇生产调度模型较确定性模型利润减少,但生产任务数量增加,设备空闲时间缩短,从而增强了调度方案的可靠性,实现了不确定条件下生产操作性和经济性的综合优化。 相似文献
7.
提出一种基于Guass—Seidel迭代法的多效并流蒸发过程的模拟以及优化方法,并以一简单三效并流蒸发过程为例,详细阐述了Guass—Seidel迭代法模拟的具体步骤。最后经一实例计算说明该算法的可行性,该算法具有对初始值要求不高、收敛速度快,稳定性好的特点. 相似文献
8.
9.
10.
针对间歇生产过程柔性操作和动态变化的特征 ,提出综合应用基于知识的调度算法和多代理技术实现间歇生产过程智能调度的方法 ,建立间歇过程智能调度的结构模型 ,并以一间歇过程示例的仿真研究说明所提出方法的思路和可行性 相似文献
11.
Yisu Nie Lorenz T. Biegler John M. Wassick 《American Institute of Chemical Engineers》2012,58(11):3416-3432
A systematic framework for the integration of short‐term scheduling and dynamic optimization (DO) of batch processes is described. The state equipment network (SEN) is used to represent a process system, where it decomposes the process into two basic kinds of entities: process materials and process units. Mathematical modeling based on the SEN framework invokes both logical disjunctions and operational dynamics; thus the integrated formulation leads to a mixed‐logic dynamic optimization (MLDO) problem. The integrated approach seeks to benefit the overall process performance by incorporating process dynamics into scheduling considerations. The solution procedure of an MLDO problem is also addressed in this article, where MLDO problems are translated into mixed‐integer nonlinear programs using the Big M reformulation and the simultaneous collocation method. Finally, through two case studies, we show advantages of the integrated approach over the conventional recipe‐based scheduling method. © 2012 American Institute of Chemical Engineers AIChE J, 2012 相似文献
12.
13.
14.
15.
16.
In reality, crudes from unloading storage tanks at a docking berth may experience long-distance pipeline transportation to refinery charging tanks before their processing by crude distillation units. Such pipeline transportations cause significant transport delay and crude holdup that will substantially affect plant production performance. Unfortunately, current short-term crude scheduling studies have never systematically considered these issues. In this work, a new continuous-time crude scheduling model has been developed, which addresses the long-distance pipeline transportation and other realistic considerations such as brine settling and multiple jetties for crude unloading. The feeding of crudes into pipeline, and crude movements inside pipeline, as well as crude discharging to the receiving charging tanks are combined with the continuous time formulation of crude scheduling. The efficacy of the developed scheduling model has been demonstrated by three case studies including one industrial size example. An outer-approximation (OA) based iterative algorithm (Karuppiah et al., 2008) is implemented to successfully solve the case studies. 相似文献
17.
最佳间歇水循环网络的合成和时序安排 总被引:2,自引:1,他引:1
This work develops an optimization-based methodology for the design and scheduling of batch water recycle networks. This task requires the identification of network configuration, fresh-water usage, recycle assignments from sources to sinks, wastewater discharge, and a scheduling scheme. A new source-tank-sink representation is developed to allow for storage and dispatch tanks. The problem is solved in stages by first eliminating scheduling constraints and determining minimum usage of fresh water and wastewater discharge. An iterative procedure is formulated to minimize the total annual cost of the system by trading off capital versus operating costs. The work overcomes limitations in previous literature work including restricted recycle within the same cycle, lumped balances that may not lead to feasible solutions, and unrealistic objective functions. A case study is solved to illustrate the usefulness of the devised procedure. 相似文献
18.
Elisabet Capón‐García Aarón D. Bojarski Antonio Espuña Luis Puigjaner 《American Institute of Chemical Engineers》2011,57(10):2766-2782
In batch process scheduling, production trade‐offs arise from the simultaneous consideration of different objectives. Economic goals are expressed in terms of plant profitability and productivity, whereas the environmental objectives are evaluated by means of metrics originated from the use of life cycle assessment methodology. This work illustrates a novel approach for decision making by using multiobjective optimization. In addition, different metrics are proposed to select a possible compromise based on the distance to a nonexistent utopian solution, whose objective function values are all optimal. Thus, this work provides a deeper insight into the influence of the metrics selection for both environmental and economic issues while considering the trade‐offs of adopting a particular schedule. The use of this approach is illustrated through its application to a case study related to a multiproduct acrylic fiber production plant, special attention is put to the influence of product changeovers. © 2010 American Institute of Chemical Engineers AIChE J, 57: 2766–2782, 2010 相似文献
19.
针对产品处理时间不确定条件下中间存储时间有限多产品间歇生产过程调度问题, 采用三角模糊数描述处理时间的不确定性, 通过一种模糊排序的方法建立了以最小化模糊最大完工时间的值以及不确定度作为调度目标的数学模型, 提出一种基于改进粒子群和分布估计的混合算法(IPSO-EDA)。IPSO-EDA算法在粒子群更新公式中引入基于所有粒子自身最优位置的优质个体分布信息, 提高了算法的全局搜索能力, 同时采用NEH初始化获得理想的初始解, 采用NEH局部搜索提高算法的局部搜索能力。通过正交实验设计对算法的参数进行调节, 仿真结果表明了所提出算法的有效性和优越性。 相似文献