最优化生产技术在模具企业车间作业计划中的应用研究

通过对作业计划编制方法和模具企业生产系统特点的简略分析与总结 ,提出在模具企业车间作业计划中运用最优化生产技术。研究了最优化生产技术应用于模具企业车间作业计划需要进一步改进的几个关键问题。针对模具企业生产过程的动态多变性 。

生产最优化管理需研究的所有参数

生产最优化管理，也就是结点分析，和网络算法一样，已成为油井气井分析的主要工具。生产最优化管理被广泛用于单井分析，有时也用于多井分析。在油井中流体流经各个部位产生的压降，如油藏、完井器、井底安全阀、油管、阻滞阀、地面管线等都可以通过选择一个适当的求解节点的方法来分析。对于多井或复杂管线系统，网络法是最强有力的方法，并且多次用于模拟复杂的流结构，这两种方法的目的就是对单相或两相流动提供压力或流动速率的解法。这有助于技术人员改进下面参数，如油管尺寸、管尺寸、完井射孔密度、地面操作压力等，并为改善总的流动速率提供更有效的设计。

基于灰色关联度/遗传算法的农产品产量品质最优化生产模型研究

采用灰度关联度分析法与遗传算法相结合的方法,建立一个通过调整农产品施肥搭配方案和种植行间距,实现农产品在保证品质的前提下产量最大化的生产模型,并用洋葱的实验种植数据对模型进行验证,取得良好效果,对指导种植生产具有重要意义。

考虑市场因素的化工间歇生产的最优排产方式研究

引入了“库存量”的概念 ,得出只有符合市场要求的生产计划才是最优的。并形成结论 :当市场旺盛时以优化生产操作方式为原则进行排产 ;

面向瓶颈的离散生产系统在制品库存控制与仿真

针对当前在制品库存控制研究较少考虑系统瓶颈的现状,从最优化生产技术(Optimized Production Technology,OPT)的思想出发,在辨别出系统瓶颈的基础上,设计以瓶颈为中心驱动的推、拉结合(Push&Pull)的生产控制方式,以有效减少整个系统的在制品库存;建立面向瓶颈的在制品库存前-反馈集成控制(B-WFFIC)模型,稳定并减少瓶颈工序前的在制品库存;最后通过实例应用和仿真验证取得了较优的结果。

基于OPT的炼钢-连铸生产调度问题研究

将最优化生产管理技术 (OPT)思想应用于钢材的冶铸轧生产调度 ,给出优化的瓶颈工序生产调度模型。计算结果分析表明 ,适用于离散型生产系统的OPT在冶金生产系统同样取得提高生产利用率、缩短生产周期。

基于并行工程和网络计划技术的模具生产进度编制方法

在充分考虑模具生产的特点和生产活动之间并行性的基础上,建立了单副模具典型生产过程的细化网络图,提出了一种基于并行工程、网络计划技术和最优化生产技术(OPT,Optimal ProductionTechnology)的模具生产进度计划编制方法。通过算例及其结果分析,表明了方法的可行性和有效性。

利用广义拉格朗日方法进行有效的历史拟合和最优化生产

介绍了油藏历史拟合及油藏动态注水最优化问题的一种新方法。对于动态注水最优化的问题,解出了使净现值达到最大值时有限制条件的油藏渗流方程的最优解。同样,在历史拟合时,我们通过测量压力和饱和度得到油田的渗透率。两种情况的问题是把找到的与之相关的广义拉格朗日函数的鞍点用公式表示。基于伴随矩阵方程的解,我们把一系列传统的最优控制方法与该方法进行了对比。在例子中使用同样或者少于伴随矩阵的计算量来测验该方法得到近似的结果。新方法的一个优点是不用在每次迭代时都求解渗流方程的精确解。作为最优化收益,渗流方程应该在收敛点处有效。因此,新方法最小值算法的每一次迭代成本均低于伴随矩阵方法。

Medium optimization for enhanced production of cytosine-substituted mildiomycin analogue (MIL-C) by Streptoverticillium rimofaciens ZJU 5119

Cytosine-substituted mildiomycin analogue （MIL-C） was produced effectively by supplementing cytosine into the culture of Streptoverticillium rimofaciens. In order to improve the yield of MIL-C, statistically-based experimental designs were applied to optimize the fermentation medium for S. rimofaciens ZJU 5119. Fifteen culture conditions were examined for their significances on MIL-C production using Plackett-Burman design. The Plackett-Burrnan design and one-variable-at-a-time design indicated that glucose and rice meal as the complex carbon sources, and peanut cake meal and NH4NO3 as the complex nitrogen sources were beneficial for MIL-C production in S. rimofaciens ZJU 5119. The results of further central composition design （CCD） showed that the optimal concentration of glucose, rice meal and peanut cake meal were 18.7 g/L, 64.8 g/L and 65.1 g/L, respectively. By using this optimal fermentation medium, the MIL-C concentration was increased up to 1336.5 mg/L, an approximate 3.8-fold improvement over the previous concentration （350.0 mg/L） with un-optimized medium. This work will be very helpful to the large-scale production of MIL-C in the future.

Study on Optimal Strategy of Grade Transition in Industrial Fluidized Bed Gas-Phase Polyethylene Production Process

A model of grade transition is presented for a commercialized fluidized bed gas-phase polyethylene production process. The quantity of off-specification product and the time of grade transition can be minimized by the optimization of operating variables, such as polymerization temperature, the ratio of hydrogen to ethylene, the ratio of co-monomer to ethylene, feed rate of catalyst, and bed level. A new performance index, the ratio of melt flow (MFR), is included in the objective function, for restraining the sharp adjustment of operation variables and narrowing the distribution of molecular weight of the resin. It is recommended that catalyst feed rate and bed level are decreased in order to reduce the grade transition time and the quantity of off-specification product. This optimization problem is solved by an algorithm of sequential quadratic programming (SQP) in MATLAB. There is considerable difference between the forward transition and reverse transition of grade with regard to the operating variables due to the non-linearity of the system. The grade transition model is extended to a high space time yield (STY) process with the so-called condensed model operation. In the end, an optimization strategy for multi-product transition is proposed with two-level optimization of the objective function J(x,u) on the basis of the optimal grade transition model. A sequential transition of six commercial polyethylene grades is illustrated for an optimal multi-product operation.

OPT理论在盐化工设备改造中的应用

着重介绍了最优化生产技术的基本思想、作业计划方法及其在盐化工设备改造中的应用。

最优化生产技术

最优化生产技术(Optimized Production Technology,OPT)是一种全新的生产管理方法,其根据是一个简单的概念:生产最大化未必是利润最大化的最佳途径。OPT于七十年代出现在以色列,随后很快被移植到美国。目前,美国有20多家大公司采用了以OPT为基础的生产管理制度。OPT的内容主要有以下三点: 1.最大限度地挖掘“瓶颈”的潜力。所谓“

横波各向异性在含油多孔砂岩射孔方案和最优化生产中的应用

在本例研究中，横波各向异性数据是由偶极横波声测井在几个多孔的砂岩地层采集的，这些地层是在苏伊士湾钻井时遇到的。交叉偶极横波数据来自偶极子横波成象仪。处理这些数据获得定向快、慢横波。然后。用各向异性数据求出主水平应力的方位和量值。几个高孔隙度的砂岩地带表现为重要的横波各向异性。观察表明。出现在孔隙度30％的砂岩的横波各向异性，很可能归因于一种重要的应力不平衡。迄今为止，通常认为横波各向异性更多出现在致密岩石，如碳酸盐岩或者低孔隙度砂岩。观测得到的横波各向异性方位在西北一东南方向，它与已知的苏伊士湾构造状态的应力走向一致，即Clysmic断层走向。这一各向异性信息被证明是很有价值的，由于推测有出砂现象，它被用在优化射孔和开采方案上。由于考虑了横波各向异性，就可以在测试之前进行了出砂分析，并计算最大的临界出砂压降。本文的主要技术价值在于它清楚地证明了，在深度浅、含油的和高孔隙的砂岩存在着大的横波各向异性；根据作者的知识，这一点在过去文献报告中，即使有也是很少的。因此，本观察可有助于促进并提高在高孔隙度砂岩使用横波各向异性技术。

Williams-Otto Plant Control Based on Production Planning Associated to Coordinated Decentralized Optimization and Plantwide Control Techniques

Manufacturing plants are increasingly complex and integrated, requiring control systems able to identify the interactions between the various operating units. Production planning and control design of a process are tools that, if combined, bring many economic benefits to the processes since they aim to identify and maintain optimal decision operations to a system. This work uses such integration between production planning and plantwide control to propose a control system for the Williams-Otto plant from the definition of the operating optimal point for coordinated decentralized optimization, in which the original optimization problem decomposition into smaller coordinated problems ensure that the found local optimum also meets the requirements of the global system. The results for decentralized optimization are satisfactory and very similar to the global optimum problem and to the control system response proposed based on the optimal obtained. It is effective taking smooth actions, working with （economic） optimal set points （economically） of operation. The unification of production planning techniques and plantwide control techniques is an effective tool for the control system design for entire plants.

多个MRP系统在供应链环境下的协调策略研究

物料需求计划系统的目的是准时生产,减少库存,以实现单个企业内部的最优化生产。供应链管理则是从系统观点出发,纵观全局,力求使供应链整体的效益达到最大化。供应链管理是当前市场环境里最有效的管理方式,但是当采用了物料需求计划系统的多个企业组成供应链时,物料需求计划系统追求企业內部最优的特性和供应链致力于全体最优的特性就会产生冲突,因此必须进行协调合作。在分析了各种可能产生冲突的原因的基础上,提出了一些协调策略。

A GA Based Algorithm to Solve the Multi-stage Supply Chain Optimization Problem

The multi-stage supply chain optimization problem is an important subject for research. Syaxif et al. have studied the problem formulated by a 0-1 mixed integer linear programming model, and presented a st-GA （spanning tree-based genetic algorithm） by using Priifer number representation as the solution method of the model. On the basis of the work done by Syarif et al., a rst-GA （revised st-GA ） to solve the multi-stage supply chain optimization problem, is presented in this paper by means of introducing new sym- metric encoding ＆ decoding procedures of Priifer number, and adopting new chromosome＇s decoding strategy, etc. To facilitate building related decision-making support system, a C language implementation method of the rst-GA is also presented in this paper. Numerical experiments have validated that the rst-GA has better performance than the st-GA.