化工工业园区全局水网络系统优化与集成

Setting chemical industrial parks is the necessary approach for the world chemical industries to meet their environment-friendly and sustainable development expectations. Therefore, the water systems, which exit as important part of chemical industrial parks, should be well designed for the water-saving and cost-reducing consideration. However, as water is usually independently used by every single plant, the water consumption and the produced cost are usually very high for the present parks. For this issue, the global water network optimization and integration study is supposed to be one of the effective scientific methods that can break the water-using bottleneck. By taking the overall water networks of industrial parks for study and the system science and theory for basis, this research will exploit the water reuse paths between the plants in a park. A "common area" involved network mode will be introduced to present the interaction between the water networks of plants, then a new synthesis method which can break through the plant boundaries to achieve the rational allocation and sustainable utilization of water resource, will be proposed. Based on the above work, the multiple operation cases problem will be considered afterwards. The adjustment strategy for streams in "common area" will be set up, and the flexible design of the network system could be achieved accordingly. The study also will examine the coupling relationship of water utilization and energy utilization in the chemical industrial parks. A simultaneous synthesis method for the water allocation networks and heat exchange networks will be proposed finally. The research in this project is aimed to find scientific ways to reduce the resource consumption and pollution emission for industrial parks. It is supposed that all of these studies could lay a foundation to the later work of the large-scale network integration for industrial parks.

化工工业园区是世界化工行业实现环境友好和可持续发展的必经途径。用水系统是化工园区的重要组成部分，目前化工园区中各单厂用水独立，存在消耗大和成本高等问题。因此，针对化工园区的全局水网络优化与集成研究成为降低水消耗，解决用水瓶颈的有效科学方法之一。本项目以园区全局水网络为研究对象，以系统科学理论为基础，考察单厂间水资源的回用路径，通过提出设有“公共区域”的网络交互方式，建立能够突破厂际限制、实现厂际间水资源合理分配与可持续利用的水网络综合新方法；同时，以多工况下的系统柔性设计为研究目标，探索针对厂际间水再分配网络的调节策略，解决不同工况下最优调节方案的识别问题；并考察工业园区中用水与用能的耦和关系，在水网络系统优化的基础上开展园区用水与用能的同步集成研究。本项目研究旨在探索从全局角度实现园区节水降耗与污染减排的科学方法，研究成果能够为以工业园区为背景的大规模网络集成研究和实际应用奠定理论基础。

化工工业园区作为化工企业集群与共生的主流模式为资源的共享与节约提供了广泛机会，因此在现有工艺条件下挖掘水资源循环利用的可能性，尤其是突破过程和厂际限制，开展化工工业园区中单厂及厂际间水资源的合理分配、使用和再生研究，对于进一步推进化工工业的节水和降污具有非常重要的现实意义。本项目以园区全局水网络为研究对象，以系统科学理论为基础，围绕工业园区水网络综合重点开展了三部分内容的研究：（1）在考察化工工业园区中单厂与单厂、单厂与园区用水关系的基础上，首先开展了新的园区水网络综合方法研究。提出基于单厂的水网络交互新方式；分别构建考虑厂际间直接回用与间接回用的园区水集成超结构；并考察厂际间集中再生与厂内离散再生操作的配置与选择问题；建立MINLP数学模型分别以水资源的节约与经济学最优为目标进行网络综合，其中通过引入一系列的结构约束提高网络的可操作性。（2）园区多阶段规划方法研究。将园区建设与园区规模变化等发展情况所导致的多工况问题分解为两个子问题：可预测问题与不可预测问题，分别对应网络的设计型与改造型规划。其中前者为获得园区用水的长远多阶段最优规划设计，建立了一个包含单阶段内水资源分配及多阶段间分配关系的MINLP数学模型进行网络优化设计。后者则在模型中引入了对于已有网络信息的描述，以及调控措施约束，方法可根据不同的调控要求优化出满足设计及操作要求的调控措施。（3）考察工业园区用水与用能的耦和关系，建立水、能两系统耦合超结构，分别采用序贯连续与同步求解策略实现用水与用能的分步与同步优化综合，并对两种方法进行分析与比较。基于上述一系列工作，本研究按计划开展了项目预设内容的研究，达成研究目标，所提方法在化工工业园区实现资源的有效分配、促进清洁生产、提高循环经济效益等方面有均广泛的应用与推广价值，对系统集成方法论的完善有重要意义，并为今后考虑更多资源同时利用的大规模系统集成研究奠定了坚实的理论基础。