【作者】 刘阳；

【导师】 唐加福；

【作者基本信息】 东北大学 ， 系统工程， 2009， 博士

【摘要】 钢铁工业是典型的高能耗、高排放的过程工业。在钢铁工业规模不断扩大,钢产量持续高速增长的今天,钢铁工业的发展受到铁矿资源、能源和水资源等生产要素的严重制约,资源的回收利用正日益受到人们的关注和重视。如何有效地利用钢铁冶金生产流程中产生的不同类型、不同形式的废钢铁、废渣和可重用的残次品等,对于降低生产成本、提高资源利用率、节约能源、保护环境具有十分重要的意义。逆向物流是对原材料、加工库存品、产成品,从消费地到起始地的相关信息的高效率、低成本的流动而进行有效地规划、实施和控制的过程。本文结合逆向物流的概念,在总结与分析我国钢铁行业近几十年来发展的现状,以及对几个国内大型钢铁集团的实地调查与实证研究的基础上,开展了面向钢铁工业的逆向物流系统的重用策略及其优化方法的研究工作。该研究是985工程流程工业综合自动化科技创新平台研究项目、辽宁省科技厅计划项目和国家杰出青年科学基金项目(70625001)的重要组成部分。本文首先概述了逆向物流的基础理论,包括逆向物流的概念和驱动因素、物品被退回的原因、回收物品的处理方式、回收物品的类型和特征、逆向物流的闭环结构和开环结构和逆向物流的执行者;然后从逆向物流的三个主要研究方向(网络规划、库存控制、生产计划)分别对逆向物流的研究现状进行了总结和分析;又进一步以电子行业作为典型的离散制造业,对其逆向物流产生的驱动因素和特点、废旧电子产品的三种回收模式、废旧电子产品逆向物流的研究现状进行了简要总结和介绍,目的是为研究钢铁行业的逆向物流特点,建立面向钢铁行业的逆向物流模型起到借鉴和指导的作用。最后,介绍了逆向物流在钢铁行业中的应用研究状况,包括钢铁企业的循环型物流系统框架和钢铁行业逆向物流的研究现状,为后面具体的关键技术研究奠定理论基础。总体上讲,本文的研究工作主要围绕五个关键问题展开。第三章作为关键问题1,是整个课题的重要研究基础,为后面4个关键问题的研究起到指引方向、奠定基础和提供实际依据的作用。本章分别站在两个角度建立具有钢铁工业特点的逆向物流系统结构框架。首先从钢铁工业生产流程角度出发,在概述其三个生产阶段中各主要工序及其特点的基础上,进一步对每个生产阶段的回收物质流进行了分析,并建立了面向整个钢铁工业生产流程的逆向物流网络图;另外从钢铁工业产生的主要固、液体废弃物角度出发,在概述其种类、特点和危害性的基础上,进一步对两种形态的废弃物的回收物质流进行了分析,并分别建立了面向几种主要固体废弃物和主要液体废弃物的逆向物流网络图;最后概述了作者在国内三个大型钢铁集团中进行实证考察研究的主要工作,充分说明了本课题背景的实际应用意义。第四章作为关键问题2,以钢铁工业冷轧流程中产生的废酸液作为一类典型的液体废弃物,结合废酸液循环利用流程的特点,提出了一类多个环节中不同重用策略之间的组合优化及资源配置问题(即在满足特定化学成分和组织性能的条件下如何配置各种重用策略及该策略下的各种废物原料的数量);构建了一个多循环策略、多加工方式、多化工产品的特殊的逆向物流网络流程图,然后以最大化网络整体利润为目的,提出了一个多策略的组合优化模型,并设计了一个基于模拟退火的启发式算法用于求解模型;最后通过实例计算验证了模型和算法的可行性和有效性,以及考察主要控制参数对网络整体利润的影响。第五章作为关键问题3,以钢铁工业轧辊生产流程作为一类典型的闭环工业生产流程,在考虑轧辊残次品等废弃物的多种重用策略、加工与再加工两类工序交替运行的情况下,构建了一个含有三个可用库存(原料、半成品、成品)和两个回收库存的加工/再加工的闭环三阶段生产系统。对整个系统的三种生产状态、每种状态下的循环周期、三个可用库存的需求率以及在计划时间范围内各主要变量和参数之间的关系进行了详细的分析,并给出了五个库存随时间变化的曲线图。在此基础上,提出了一类基于EOQ的库存补充策略问题,最后通过实例计算检验了模型的可行性,以及考察了回收率参数对网络总费用的影响。第六章作为关键问题4,以废钢铁作为一类典型的钢铁工业固体废弃物,重点研究了社会废钢铁的回收网络优化设计问题。结合钢铁工业流程特点,以提高钢铁工业物流运作效益为目的,建立了以钢材生产厂为中心,包括多个钢铁产品用户区域、多个废钢铁回收中心、多个分类与预处理厂的回收网络的定位与能力分配模型。在分析模型约束条件特点的基础上,应用拉格朗日松弛方法将原问题分解为两个子问题,提出了一个基于拉格朗日松弛算法和DFS搜索方法的求解方法,最后通过实例计算验证了模型和算法的有效性和可行性。第七章作为关键问题5,仍然以废钢铁作为研究对象,在同时考虑三种类型废钢铁的不同循环利用模式的情况下,构建了一个特殊的闭环逆向物流系统。在分析系统特点的基础上,提出了一个带能力约束的动态批量问题,用于决策社会废钢铁的购买时间以及购买数量。模型中即融合了废钢铁循环利用流程的独有特性,又考虑了废钢铁预处理厂中的库存管理问题,为钢铁企业全方面、综合性做出社会废钢铁购买决策提供了理论依据;并设计了一个基于动态规划的启发式算法用于求解模型,最后通过实例计算验证了模型和算法的有效性和可行性,以及研究了回收站内废钢铁的单位存储费用参数、自产废钢铁和加工废钢铁两种类型废钢铁的回收率参数对社会废钢铁的回购总次数及逆向物流系统总费用的影响。更多还原

【Abstract】 The iron and steel industry is a typical high comsumption, high discharge process industry. Recently, along with the rapid growth of steel output, development of the iron and steel industry is badly restricted because of the limitation of ore resource, energe resource and water resource, hence the recovery of waste gained more and more attention from people. How to effectively utilize different types of waste became very important to reducing production cost, improving resource utilization studio, energe saving and environment protection. Reverse logistics is the process of planning, implementing, and controlling the efficient, effective inbound flow and storage of secondary goods and related information opposite to the traditional supply chain direction for the purpose of recovering value or proper disposal. Based on the definition of reverse logistics, this thesis summarizes and analyzes the characteristics of return flows in the iron and steel industry, and investigates the actual situation of steel production process in several large iron and steel companies, and then focuses on the research on recovery strategies and optimization methods for reverse logistics system in the iron and steel industry. It is a constituent part of ’985 project- Scientific and technological innovation of Integrated Automation of Process Industry platform research project’, ’Liaoning provincial division of sicence and technology planning project’ and ’National Natural Science Funds for Distinguished Young Scholar project’.In Chapter 2, basic theories about reverse logistics are firstly introduced, including definition and motives of reverse logistics, reasons of returing, manners of disposing returns, characteristics of returns, closed-loop and open-loop structures of reverse logistics system, and implementers of reverse logistics; and then the literatures about reverse logistics is overviewed from three main research orientations, namely network design, inventory management and production planning; furthermore, aiming to give some directions and references to the study of application of reverse logistics in the iron and steel industry, the application of reverse logistics in electronic industry, which is seemed as a typical discrete manufacturing industry, is special analyzed, including characteristics, motives, three collection modes of scrap electronic products, related literatures, etc.; finally, literatures about applications of reverse logistics in iron and steel industry are reviewed, and this work laies an important theoretical foundation for the study in this thesis. As a whole, this thesis focuses on following five key problems.As the Key Problem 1, Chapter 3 is the important foundation of the whole research, and supply directions and practical realities to the other four key problems. Some special reverse logistics systems are established considering characteristics of the iron and steel industy from two points of view. Firtly, focusing on the production procedure of the iron and steel industy, the three major production stages are illustrated, including constituent production procedures and characteristics; to be important and specialized, the return flows of each production stage are analyzed, and accordingly some reverse logistics systems for the whole production process of the iron and steel industry are established. Secondly, focusing on the major classes of solid and liquid wastes generated by the iron and steel industry, based on the illustration of their classification, characteristics and harmfulness, the return flows are further analyzed, and accordingly some special reverse logistics systems are established. Finally, in this chapter, some important investigation results in three large iron and steel companies are shown, which sufficiently approve the practical applications significance of this study.As the Key Problem 2, Chapter 4 focuses on recovery strategies optimization problem for acid waste recycling which is seemed as a typical class of liquid industrial waste recycling process. There are multiple strategies for waste recycling to generate multiple byproducts and then these byproducts are further transformed into multiple types of chemical products via different production patterns. A mixed integer programming model is developed to help determine which recycling strategy and which production pattern should be selected in a given quantity in order to maximize the marginal profits. A simulated annealing (SA) based heuristic algorithm is developed to solve the problem. Finally, an experiment is designed to test the effectiveness and feasibility of the proposed method, furthermore, the effects of model parameters on profit are discussed to help manufacturers organize their waste recycling network.As the Key Problem 3, Chapter 5 focuses on an EOQ inventory management problem with deterministic demands and returns for a three-stage steel roller producing process which is seemed as a typical class of closed-loop production process in the iron and steel industry. A three-stage manufacturing/remanufacturing system with three serviceable inventories and two recoverable inventories is introduced. By considering manufacturing and remanufacturing in the different stages, three modes of production are identified. The cycle times of each mode, demand rates for serviceable inventories, and their relationships in a planning horizon are further discussed through analyzing the characteristics of the production system. Then, the inventory profiles in the system are studied, and an EOQ model is proposed to decide on the timing for ordering serviceable inventories with the view to minimizing the average cost. Finally a numerical example is used to demonstrate the feasibility of the model, and to examine its effects on the orders response time and the average costs. As the Key Problem 4, Chapter 6 focuses on a network design problem for obsolete scrap steel recycling process which is seemed as a typical solid waste recycling process in the iron and steel industry, and proposes a location and allocation model basing on analysis of business flow from manufacturing of steel-made product, and collecting to recycling of scrap steel with multiple customer zones and multiple scrap steel collection centers. A Lagrange relaxation decomposition based heuristics combined with Depth First Search (DFS) approach is developed. Finally, an experiment is designed to test the effectiveness and feasibility of the proposed model and algorithm.As the Key Problem 5, Chapter 7 focuses on a dynamic economic lot sizing problem for the three types of scrap steel recycling. A specific closed-loop network for scrap steel recycling is established, and then the relationships between the forward chain and the reverse chain are investigated. A Dynamic Economic Lot Sizing model with time-varying demands is proposed to decide the optimal purchasing time and the optimal procurement quantity of obsolete scrap steel towards minimal total cost of the whole network. A dynamic programming based algorithm is discussed to solve the problem. Finally several numerical experiments are designed to validate the effectiveness of the model and the algorithm, as well as to examine the effects of parameters on the optimal results. From the results of experiments, one can observed that low unit holding cost in collection center and high return rates of home scrap steel and prompt scrap steel more contribute to reducing the total cost of the whole network and the optimal ordering times of obsolete scrap steel from society.更多还原