共查询到16条相似文献,搜索用时 187 毫秒
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针对原油短期调度多目标优化问题,在分析已有多目标模型对原油调度过程中的供油罐个数、供油罐切换次数、原油在管道中的混合成本和供油罐罐底混合成本这4个目标优化的基础上,本文建立的模型增加了原油在管道转运过程中的能耗成本这一优化目标,使模型更吻合生产实际。在SPEA2算法中引入极值归档集,结合MOGWO算法指导极值归档集更新来提高算法的全局搜索能力;利用余弦相似度对归档集进行裁剪操作,以保证归档集中个体的多样性。将改进算法与多个具有代表性的进化多目标优化算法进行对比实验,结果表明,本文所提出算法在求解原油短期调度问题时性能较优。 相似文献
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在原油处理过程短期生产计划的递阶求解方法中,原油处理短期生产计划问题分为上下两层,上层根据市场需求产生一个目标炼油计划;在此基础上,下层得到一个详细生产计划以实现目标炼油计划。研究了在上层目标炼油计划已知的情况下,下层详细生产计划的求解问题。为该问题建立了基于离散时间表示的混合整数线性规划模型,分析了问题的特点并将其进行转化,给出了基于启发式的求解方法,在保证目标炼油计划实现的前提下,对原油转运过程中油品切换及不同油品的罐底混合进行了优化,取得了一定的成果。用一个工业实例验证了启发式规则的可行性和有效性。 相似文献
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提出了原油处理过程短期生产计划是否存在可解性的问题。从控制理论的角度出发,建立了原油运作过程的短期生产计划模型,研究了输油管道调度问题的复杂性,最后得出炼油短期生产计划调度原问题为NP hard问题,即该问题很难运用数学规划方法求解的结论。因此需要寻找更为有效的方法求解该类问题。 相似文献
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针对生产调度优化问题,提出了一种集成启发式规则的混合整数规划调度模型。在分析启发式规则逻辑关系的基础上,用布尔逻辑变量表达启发式规则建立了启发式规则的基本逻辑表达式及其等价代数表达式,基于基本表达式给出了启发式规则的数学表达。将启发式规则的代数表达式与混合整数规划相结合,实现了启发式规则的集成。集成启发式规则的混合整数规划调度模型在结合启发式规则的基础上进行数学优化,克服了混合整数规划难以直接利用经验规则和基于规则的调度优化性难以保证的不足。最后以某炼油过程生产调度为例说明了模型的有效性。 相似文献
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石化炼油企业原油处理过程的短期生产计划是一个挑战性的问题,至今为止没有可应用于实际的方法和工具.因此,开发一种仿真方法消除计划人员的复杂计算以便致力于决策过程非常必要.本文在分析问题的动态特性的基础上,建立了原油处理过程的混合Petri网模型.基于模型所给出的运行逻辑,提出了一个有效的仿真模型.应用该模型进行仿真可以验证计划的可行性,也可估计计划的性能,这使得计划人员的工作大大简化. 相似文献
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《工业工程与管理》2017,(5)
个性化产品的生产过程具有非重复性,致使工序的加工时间不确定且难以估计其概率信息。因此,传统的确定调度和随机调度方法不再适用。采用最小化最大后悔值的鲁棒优化方法,研究变速平行机加工环境下个性化产品的生产调度问题。首先,采用区间情景描述不确定的加工时间,构建基于后悔值准则的个性化产品鲁棒调度模型;其次,证明任意调度方案带来的最大后悔值可通过求解一个指派问题得到;然后,提出基于混合整数规划和迭代松弛过程的两种精确算法获取最优解;最后,通过仿真实验评估两种精确算法的有效性,结果表明基于混合整数规划的精确算法明显优于迭代松弛算法,并且可以快速求解中小规模的调度问题。 相似文献
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随着石油储备建设的高速发展,油罐规模正向大型化以及能适应极限工况的方向发展.为了避免油温过低而造成凝罐等安全事故,需要准确掌握罐内油品温度场的变化规律.本文根据能量守恒定律,采用分步式算法求解储罐传热系数,将其代入到由Taylor级数展开法所建立的节点非稳态传热离散方程中,并进行数值求解.对大庆某10×104m3浮顶储罐的应用分析表明:随着环境温度的降低,罐内油品温度降速率逐渐增大,储罐液位越高,容积越大,罐内原油温度就越高,温降速率就越小.研究结果对于优化大型浮顶罐的储存工艺设计,保障油库安全经济运行提供了重要的技术支持. 相似文献
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As a result of an increasingly competitive market, companies must find ways to organize their activities regarding their economic outcome. An important feature in this context involves transportation operations, usually considered one of the major bottlenecks in the production chain. While delays imply loss of time and lack of resources, deliveries ahead of the deadlines may cause excess of inventories. Therefore, every company must pursue efficient transportation schedules within their operational planning. This work addresses short-term crude oil scheduling problems in a distribution complex that contains ports, refineries and a pipeline infrastructure capable of transferring oil from the former to the latter. The ports comprise piers, which receive vessels for discharging, storage tanks and a network that connects each other. The refineries have their own storage infrastructure, modeled as a large storage unit, along with crude distillation units, considered as constant level consumers. The problem involves a number of other issues, including intermediate storage, settling tasks and allocation of crude oil by its qualitative characteristics. A decomposition strategy based on large-scale mixed-integer linear programming (MILP) continuous-time models is developed. First, an MILP model that considers an aggregate representation for the pipeline and intermediate storage infrastructure is proposed. Decision variables involve the assignment of oil tankers to piers as well as tanker unloading and pipeline loading operations. The solution of this model provides the initial conditions for MILP models that represent the pipeline and intermediate storage infrastructure at a detailed level. Algorithms based on the LP-based branch-and-bound method are employed. Results from a port scenario of 13 tankers, 4 piers, 14 crude types, 18 storage tanks and 2 pipelines were obtained in approximately 90 minutes from an MILP problem containing 1996 continuous variables, 1039 binary variables and 7203 constraints. 相似文献
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Three basic modes of failure are known for oil tanks: manufacturing defects, mechanical damage, and corrosion. Most of the
tanks currently in use and manufactured in or prior to the 90s, are subject to leaking caused by internal corrosion. Corrosion-induced
leakage always results in environmental damage by underground and/or aboveground oil contamination. Considering the costs
related to decontamination and to replacement of residential tanks, the possibility of corrosion should be carefully addressed.
To accomplish this task, the most common issues related to tank corrosion must be recognized and understood. This article
is an overview of the corrosion mechanisms in aboveground residential tanks made of non-coated mild steel. 相似文献
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针对卧式储油罐罐体发生纵向倾斜和横向偏转引起油面位置的3种不同高度,分别建立了储油体积与油位高度以及倾斜角度和偏转角度之间的积分方程,并给出罐体变位后的储油体积标定值。结果表明:该模型比较全面地反应了实际状况,为储油罐发生变位后的罐容表重新制定提供了一种可行的方法。 相似文献