【作者】 蒲生彦；

【导师】 王有乐；

【作者基本信息】 兰州大学 ， 环境工程， 2009， 硕士

【摘要】 近年来,水资源的浪费和污染日趋严重,已经成为我国经济建设中一个亟待解决的问题。过程工业不但消耗大量的新鲜水,而且排放大量的废水,是天然水体中污染物的重要来源。工业用水约占我国用水总量的四分之一,工业用水节约与废水减量技术具有特别重要的意义,是世界各国共同关注的重要课题。在这种背景下,本论文对过程工业的废水处理网络的优化设计进行了尝试。水系统集成技术把企业的整个用水系统作为一个有机的整体来考虑水在系统中的优化分配,能够取得显著的节水效果。为节水减排的研究提供了技术支撑和系统化的方法,在理论研究上取得了一定的进展,但在实际工业生产中,对于复杂的系统应用还有一定困难,有许多问题有待研究解决。本文在总结过程集成方法的相关研究成果的基础上,将过程集成技术中的夹点技术相关理论应用于过程工业用水系统。水夹点技术的应用可以有效地节约过程工业的新鲜水用量,大幅减少废水排放量。本论文的主要内容有:1、从系统工程的角度,将整个用水系统作为一个有机的整体进行集成,通过对用水过程进行定量的分析与评价,提出用水系统综合优化改进的方向,通过合理利用相关的节水技术、方法对用水系统进行优化设计或改进,实现用水系统整体优化。总结了水分配网络综合的研究内容、方法和研究进展。2、探讨了该模型对废水减量的制约与联结关系。基于用水系统流结构模型,揭示了过程用水的共性规律,以及各个环节(子系统)和整个系统的用水质量平衡方程,阐明了各个环节中水流的构成、特点、作用、损耗以及相互之间的联结制约关系。并在此基础上对过程集成的基本概念和相关原理进行了阐述。3、利用水夹点技术寻找用水系统最少新鲜水用量,即夹点,并以夹点为节水目标引入数学方法分配水源,设计最优用水网络。探讨了应用夹点技术进行水系统设计的C-M图、浓度组合曲线的构造原理、水夹点设计原则及进行水系统设计的具体步骤,并通过工程实际应用,进一步验证了所提出的水系统夹点设计方法的先进性和实用性。最后,应用该方法进行数例分析,节水成效显著。在此基础上对基于过程改变后的夹点分析进行了探讨。4、在水夹点分析基础上建立过程使用新鲜水、排放废水和回用的各种可能匹配方案的用水网络超结构模型。在满足工业过程的前提下,确定最小新鲜水用量和废水排放量,并以此为目标设计出最优的工业用水网络,并对模型的求解问题进行了探讨。该超结构的数学模型为一组非线性方程,可以利用GAMS等数学软件进行求解,得到各个周期的最小新鲜水量和最优的用水网络结构。更多还原

【Abstract】 Industrial water accounts for about a quarter of the total water in China. Industrial water reuse and wastewater minimization technology makes great sense and it is the focus of the world’s attention. Process industry not only consume large amounts of fresh water, but emit a considerable amount of wastewater, which is an important source of natural discharges of pollutants. In recent years, increasing pollution and waste of water resources has become a problem of our economic development problems. It also made for industrial process water-saving abatement requirements.Against this background, this paper tries to optimization design to water-using network on the production system. Water system integration, which treats the water utilization processes in an enterprise as an organic whole to consider how to allocate water in a water system, shows remarkable effectiveness in saving water. On the basis of summing up the results of relevant research about process integration technology, water-pinch technology in process integration technology is applied to water-using network of Process industry production. Process integration technology for the study of water conservation abatement provided technical support and systematic approach. It has made some progress in the research process. But in actual industrial production, many problems remain to be to find and solutions to complex system applications that have certain difficulties. Application of water-point technology can effectively conserve fresh water consumption of industrial processes and significantly reduce wastewater emissions. Water pinch technology is one of water system integration technologies which is used in water-using network optimal design to improve the level of wastewater reuse.The main contents of this paper are as follows:1. From the viewpoint of systems engineering, in this model, water conversion, utilization and wastewater reclamation and regeneration have been considered systematically. Based on the quantitative analysis and evaluation for the water utilization process, the direction of integrated optimization and improvement for water use is pointed out. The optimization objectives and corresponding optimization strategies are proposed, which can provide guidance for water-saving and drainage-reduction. Some feasible technologies on water-saving are discussed, which is helpful to optimize water utilization systems as a whole.2. This paper discusses the model reduction of waste water and connection relations between the constraints. Water systems based on the flow structure model, revealing the common law of the process water, as well as the various links (subsystem) and the entire system of water mass balance equation, to clarify the water in every aspect of the composition, characteristics, roles, and between loss of relations linking constraints. On the basis of the process of integration of the basic concepts and related principles are described.3.The principles of water pinch technology is introduced, minimum fresh water consumption pinch can be found with the water pinch technology, and mathematical mothed is brought in to distribute water resource, and design the optimal water-using network. Formulated the C-M figure with water pinch point technique for designing water system, the structuring principle of composite concentration curve , principle of designing water pinch point and the procedure to design water system. The advanced and practical features of the design method of water system pinch point have been perfected and verified through engineering application. Last, the method was applied to analyze an example, the effect was obvious in water saving, and discusses on the main way of water-pinch technology approach.4. Based on the water pinch analysis, a super structure of water utilization networks can be built which involves only feasible and better retrofit options. Then an improved mixed integer nonlinear programming (MINLP) model for the network super structure is proposed which considers the fresh water usage, wastewater discharge and reuse of process. The corresponding mathematic model involved a set of nonlinear equations is solved by the GAMS (general algebra model system) software tool. This method could achieve minimal fresh water use and optimal network assignments simultaneously.更多还原