【作者】 杨烨；

【导师】 陈伟达；

【作者基本信息】 东南大学 ， 管理科学与工程， 2019， 博士

【摘要】 我国是钢铁生产和消耗大国,钢铁工业粗放型生产方式以及国民经济的高速发展,导致钢铁产能过剩、钢铁产品大量囤积,为此,钢铁业提出了减少粗钢生产、增加废钢铁生产比的结构调整方案。近年来,气候变暖问题引起世界关注,各个国家纷纷制定减排目标,以承担相应的减排义务,国家层面的减排目标必然要分解到企业生产运营层面上,才能得以落实,钢铁生产具有高能耗、高排放的特点,探寻节能减排的绿色生产发展道路是钢铁企业不可推卸的责任和义务。相对于以铁矿石为主要原料、以高炉和转炉为主要冶炼设备的“长流程”炼钢,以废钢铁为主要原料、以电弧炉为主要冶炼设备的“短流程”炼钢,是更为节能、减排、环保且大量消纳废钢铁的绿色生产方式。但是,我国用电负荷过高,电力成本一直居高不下,电力政策和电力成本一直以来制约着以电力为主要能源的“短流程”炼钢的发展。冶炼生产调度是废钢铁重新实现其价值的核心步骤,配料是冶炼生产前的关键环节,两者相互影响、紧密相关。因此,本文对分时电价下废钢铁配料和生产调度集成优化问题的研究具有重要的学术价值和实践意义。本文综合利用生产调度、运筹学、鲁棒线性规划相关理论,围绕分时电价下废钢铁配料和生产调度集成优化相关问题进行研究。首先分别研究了废钢铁配料优化问题和分时电价下废钢铁生产调度优化问题,实现废钢铁配料系统和废钢铁生产调度系统的局部优化,为后续研究奠定基础,然后从整体角度对分时电价下废钢铁配料和生产调度集成优化问题进行进一步探索。具体的研究内容如下:(1)本文从废钢铁配料优化问题、考虑能源因素的车间生产调度问题、钢铁/废钢铁生产调度问题、鲁棒线性规划问题四个方面进行文献综述。其中,考虑能源因素的车间生产调度问题,主要从分时电价下单一外部电网供电的车间生产调度问题、考虑可再生能源供电的车间生产调度问题两方面详细展开阐述;对于钢铁/废钢铁生产调度问题,主要从静态钢铁/废钢铁生产调度问题、动态钢铁/废钢铁生产调度问题、分时电价下单一外部电网供电的钢铁/废钢铁生产调度问题、考虑可再生能源供电的钢铁/废钢铁生产调度问题四个方面展开阐述,以期为后续研究提供理论依据。(2)对废钢铁配料过程中的不确定性因素进行分析,在此基础上,研究了考虑金属元素浓度不确定的废钢铁配料优化问题。以废钢铁和铁合金使用成本最小化为目标,构建了求解问题的鲁棒线性优化模型,在假设随机参数在“有界不确定”和“有界对称不确定”两种集合中取值的情况下,基于鲁棒线性规划相关理论,将鲁棒优化模型转化成两种集合下的确定等价模型。通过数值分析,验证了模型的可行性和有效性,分析了模型中重要参数对目标函数的影响。(3)分析了废钢铁生产调度流程的特点,将其归结为带有特殊生产工艺约束的混合流水车间调度问题。在此基础上,考虑到炼钢厂生产用电来自于单一外部电网供电的情况,研究了分时电价下废钢铁生产调度优化问题。以最小化分时电价成本为目标,构建了求解问题的混合整数线性规划模型。通过数值分析,验证了模型的可行性和有效性,分析了分时电价对生产调度、生产用电情况的影响。(4)在(3)的研究基础上,进一步考虑到炼钢厂生产用电同时来自于外部电网供电和内部可再生能源供电的情况,研究了分时电价下废钢铁生产调度优化问题。以最小化可再生能源发电成本、分时电价成本、电池储能系统运营成本为目标,构建了求解问题的鲁棒混合整数线性优化模型,基于鲁棒线性规划相关理论,将其转化为确定等价形式。通过数值分析,验证了模型的可行性和有效性,分析了可再生能源发电及其不确定性对废钢铁生产调度电力相关成本、生产调度活动、生产用电情况的影响,探讨了分时电价下电网供电、可再生能源供电、电池储能系统充/放/储电之间的关系。(5)在(2)和(3)的研究基础上,考虑到炼钢厂生产用电来自于单一外部电网供电的情况,以及废钢铁配料过程中金属元素浓度的不确定性,研究了分时电价下废钢铁配料和生产调度集成优化问题。以分时电价成本、生产调度准备成本、废钢铁使用成本、铁合金使用成本最小化为目标,采用模块建模方法,构建了求解问题的鲁棒混合整数线性优化模型,并将其转化为两种确定等价形式。通过数值分析,验证了模型的可行性和有效性,分析了金属元素浓度不确定性对生产成本的影响、分时电价对生产调度的影响、电价波动对废钢铁和铁合金使用量及准备次数的影响。(6)在(4)和(5)的研究基础上,考虑到炼钢厂生产用电同时来自于外部电网供电和内部可再生能源供电的情况,以及废钢铁配料过程中金属元素浓度的不确定性、可再生能源发电的不确定性,研究了分时电价下废钢铁配料和生产调度集成优化问题。以可再生能源发电成本、分时电价成本、电池储能系统运营成本、生产调度准备成本、废钢铁使用成本、铁合金使用成本最小化为目标,采用模块建模方法,构建了求解问题的鲁棒混合整数线性优化模型,并将其转化为两种确定等价模型。通过数值分析,验证了模型的可行性和有效性,分析了可再生能源供电对分时电价下废钢铁配料与生产调度的影响,探讨了分时电价下电网供电、可再生能源供电、电池储能系统充/放/储电之间的关系。本文的创新之处主要体现在以下几个方面:(1)研究了考虑金属元素浓度不确定的废钢铁配料优化问题,假设不确定参数在有界、有界对称集合中取值,并采用鲁棒优化方法对不确定参数进行处理,相对于当前文献中假设废钢铁所含金属元素浓度服从某一概率分布或模糊数类型的情况,所构建的模型更符合生产实际。(2)针对分时电价下废钢铁生产调度问题,本文在传统的混合流水车间生产调度问题建模方法的基础上,在满足废钢铁生产调度过程中各种工艺约束的条件下,构建了一种新的分时电价下废钢铁生产调度混合整数线性优化模型,相对于现有文献中的相关模型,本文中的模型更为简洁、约束性更强,具有较好的扩展性。(3)当前,对考虑可再生能源供电的生产调度问题的相关研究,或者没有考虑分时电价的影响,或者没有考虑可再生能源发电的不确定性,或者假设可再生能源发电量服从某一概率分布类型,但实际中,概率分布类型的相关信息很难准确获得。本文则假设可再生能源发电量在某一集合内取值,并采用鲁棒优化相关理论对其进行处理,基于此,研究了分时电价下联合内部可再生能源供电的废钢铁生产调度鲁棒优化问题,所构建的模型更接近于生产实际。(4)当前,废钢铁配料优化问题和废钢铁生产调度优化问题是分开研究的,造成了两种活动的不协调,考虑到炼钢厂生产用电来自于单一外部电网供电的情况,本文对两者进行集成优化研究,探索分时电价对两种生产活动的影响,以达到废钢铁配料系统和废钢铁生产调度系统整体优化和协调。(5)在(4)的基础上,进一步考虑生产用电同时来自于外部电网供电和内部可再生能源供电的情况,研究分时电价下废钢铁配料和生产调度集成优化,探索分时电价影响下,炼钢厂电力供应系统(可再生能源供电、电网供电、电池储能系统充/放/储电)、配料系统、生产调度系统之间的有效协调。更多还原

【Abstract】 China is a country of producing and consuming a large amount of steel.However,the extensive production mode and rapid development of national economy have resulted in excess production capacity of steel industry and overstock of steel products.Therefore,steel industry has put forward the structural adjustment plan to reduce crude steel production but increase the scrap steel production.Meanwhile,in recent years,the issue of global warming has aroused worldwide attention.Various countries have set emission reduction targets to undertake corresponding emission reduction obligations.The objective of emission reduction on the national level should be decomposed into enterprises’ production operation layer so that it can be effectively implemented.As a high-energy-consuming and high-emission industry,the steel industry has unshakable duties to explore a green production development path to save energy and reduce emission.Compared with the “long-process” steel-making with iron ores as the main raw materials and the blast furnace and converter as major smelting equipment,the “short-process” steel-making with the scrap steels as the main raw materials and the electric arc furnace as major smelting equipment is a more energy-saving,emission-reducing and environmentally-friendly green production mode that can make good use of scrap steel.Nevertheless,China has been facing with a high electrical load,and the electricity cost has been hovering at a high level.For a long time,the electricity kkkpolicies and cost have been major factors restricting the development of the “short-process” steel-making with electricity as the main energy.Steel-making schedule is a core step for scrap steel to re-materialize its value,and scrap steel charge is a critical link before steel-making.These two processes are mutually influencing and closely connected with each other.In this paper,integrated optimization of scrap steel charge and production scheduling under the time of use electricity tariff is studied,which is of vital academic value and practical significance.Combining theories of production scheduling,operational research and robust linear programming,this paper studies integrated optimization of scrap steel charge and scrap steel production scheduling under the time of use electricity tariff.To start with,the optimization of scrap steel charge and scrap steel scheduling under the time of use electricity tariff are explored,respectively,to realize their partial optimization and lay a solid foundation for the follow-up research.Next,integrated optimization of scrap steel charge and production scheduling under the time of use electricity tariff is further explored from a comprehensive perspective.Below is the specific research contents:(1)This paper provides a comprehensive literature review of optimization of scrap steel charge,workshop production scheduling considering energy factors,steel/scrap steel production scheduling,and robust linear programming.Among them,the issue of workshop production scheduling considering energy factors is expounded mainly from two aspects,including workshop production scheduling with single external grid power supplying under the time of use electricity tariff,and workshop production scheduling considering renewable energy power supplying.As to the issue of steel/scrap steel production scheduling,it is analyzed from four aspects,including static steel/scrap steel production scheduling,dynamic steel/scrap steel production scheduling,steel/scrap steel production scheduling with single external grid power supplying under the time of use electricity tariff,and the steel/scrap steel production scheduling considering renewable energy power supplying.All these can provide theoretical basis for the follow-up research.(2)Uncertain factor in the process of scrap steel charge is analyzed.On that basis,scrap steel charge optimization considering metal element concentration uncertainty is studied.Aiming at minimization of scrap steel and iron alloy cost,a robust linear programming model to solve the problem is built.Assume that the random parameters are valued in “bounded uncertainty” and “bounded and symmetric uncertainty” two sets.Based on theories related to robust linear programming,the robust optimization model is converted into the certain equivalent models under two sets.Through numerical analysis,the feasibility and validity of the models are verified,and the influence of major parameters in the model on the objective function value is analyzed.(3)Characteristics of scrap steel production scheduling process are analyzed,which are summarized as the issue of hybrid flow shop scheduling under the restrictions of special production process.On that basis,the condition that the electricity of steel-making plants relies on the single external grid is taken into consideration to examine optimization of scrap steel production scheduling under the time of use electricity tariff.With minimization of time of use electricity tariff cost as the objective,a mixed integer linear programming aiming at solving the problem is built.Through numerical analysis,the feasibility and validity of the model are verified,and the influence of the time of use electricity tariff on production scheduling and the use of production electricity is analyzed.(4)Based on the research work of(3),the production electricity of the steel-making plant both from external grid and internal renewable energy is considered,and how to optimize the scrap steel production scheduling under time of use electricity tariff is then studied.Aiming at minimizing the renewable energy power generation cost,time of use electricity tariff cost,and battery energy storage system operation cost,a robust mixed integer linear optimization model to solve the problem is built.And then based on theories of robust linear programming,the model is converted into a certain equivalent one.Through numerical analysis,feasibility and validity of the model are verified,and the influence of renewable energy power generation and its uncertainty on scrap steel production scheduling electricity costs,production scheduling activities and the use of production electricity is discussed.Meanwhile,the relationship among the grid power supply,renewable energy power supply and battery energy storage system charging/discharging/storage is examined.(5)Based on the research work of(2)and(3),the situation that the production electricity of the steel-making plant from single external grid and the uncertainty of metal element concentration in scrap steel charge process is considered to study how to optimize scrap steel charge and production scheduling jointly under the time of use electricity tariff.With minimization of time of use electricity tariff cost,production scheduling setup cost,scrap steel cost,and iron alloy cost as the objective,the block modeling method is adopted to build a robust mixed integer linear optimization model,and convert it into two certain equivalent models.Through numerical analysis,the feasibility and validity of the model are verified,and the influence of the uncertainty of metal element concentration on the production cost,the influence of time of use electricity tariff on production scheduling,and the influence of electricity tariff fluctuations on the times of setup,and the amount of scrap steel and iron alloy used are studied.(6)On the basis of(4)and(5),the situation that the production electricity of steel-making plant are both from external grid and internal renewable energy as well as the uncertainty of the metal element concentration in scrap steel charge process and renewable energy power generation is taken into account to study the integrated optimization of scrap steel charge and production scheduling under the time of use electricity tariff.With minimization of the renewable energy power generation cost,time of use electricity tariff cost,battery energy storage system operation cost,production scheduling setup cost,scrap steel cost,and iron alloy cost as the objective,the block modeling method is adopt to build a robust integer linear optimization model,and convert it into two certain equivalent models.Through numerical analysis,the feasibility and validity of the models are verified,and the influence of the renewable energy power supply on scrap steel charge and production scheduling under the time of use electricity tariff is studied.Meanwhile,the relationship among the grid power supply,renewable energy power supply,and battery energy storage system charging/discharging/storage under the time of use electricity tariff is discussed.Innovations of this paper are mainly reflected in the following aspects:(1)How to optimize scrap steel charge considering the uncertainty of metal element concentration is studied.Assume that the uncertain parameters are valued in the bounded uncertainty and bounded and symmetric uncertainty sets,robust optimization method is used to process them.Compared with the research that assumes the metal element concentration of scrap steel obeys certain probability distribution or belongs to certain type of fuzzy number,the charge model obtained in this paper is more consistent with real-life production activities.(2)Concerning the issue of scrap steel production scheduling under time of use electricity tariff,this paper builds a scrap steel production scheduling mixed integer linear optimization model under the time of use electricity tariff considering different process restrictions based on the traditional mixed flow shop production schedule model building method.Compared with relevant models put forward by the current literatures,this model is more concise and restrictive,demonstrating better expandability.(3)At present,research about production scheduling considering renewable energy power supply either disregards the influence of time of use electricity tariff or ignores the uncertainty of renewable energy power generation or assumes that the renewable energy power generation quantity obeys certain probability distribution type.However,in the real life,information related to the probability distribution type is hard to obtain accurately.This paper assumes that the renewable energy generation quantity is valued in certain set,and robust optimization theories are adopted to further process it.On that basis,scrap steel production scheduling robust optimization considering combined internal renewable energy power supply under time of use electricity tariff is studied.The production scheduling model obtained is closer to real production activities.(4)Currently,the issues of scrap steel charge optimization and scrap steel production scheduling optimization are mostly studied separately,thus resulting in inconsistency between these two kinds of activities.Considering that production electricity of steel-making plant is from single external grid,this paper integrates these two aspects so as to explore the influence of time of use electricity tariff on these them.And achieve integrated optimization and coordination of scrap steel charge system and scrap steel production scheduling system.(5)On the basis of research work of(4),the situation that production electricity of steel-making plant are both from external grid and internal renewable energy is considered so as to study integrated optimization of scrap steel charge and production scheduling under the time of use electricity tariff.Meanwhile,how to achieve effective coordination among the power supply system(renewable energy power supply,grid power supply,and battery storage energy storage system charging/discharging/storage),charge system,and production scheduling system under the influence of the time of use electricity tariff is explored.更多还原