汽车废热驱动喷射式制冷系统建模与优化控制研究

It is potential that the automobile exhaust heat driven ejector-based refrigeration system is an alternative to air-conditioner in automobile or refrigeration system in cold chain logistics. The exhaust heat driven ejector-based refrigeration technique is helpful for automobile energy conservation and recycle to reduce emission. It is observed that the lack of comprehensive and effective solution to tackling all possible operating conditions has been, so far, the main problem that restricts the system’s application in the real world. The essence of the problem is a typical complicated multivariable optimal control problem which requires new theory and method to deal with. Based on optimal control theory, the proposed project includes:1)building the models database of the system under automobile multiple speed operation conditions through the system performances extensive test on the pilot plant under different conditions; 2) developing cascade structure predictive control system which consists of supervisory optimization layer and process control layer to ensure that the whole system will always run most efficiently, smoothly and safely under automobile different running conditions; and 3) experimental research in an integrated automobile exhaust heat driven ejector-based refrigeration pilot plant which incorporates the functions of performance monitoring, model validation and control performance test. The proposed project aims to solve the control problems in exhaust heat driven ejector-based refrigeration system by developing the advanced control theory and method to the energy recycling field. The proposed project meets the needs by country on energy conservation and environmental protection. The project has importance of theoretical value and application prospect for energy recycling and refrigeration technologies driven by low-grade energy.

新出现的汽车废热驱动喷射式制冷技术，有望用于汽车空调和冷链物流制冷，为汽车废热能源循环利用开辟了一条新途径，正成为国内外研究热点之一。但该系统难以在多工况下稳定高效运行已成为制约其发展的瓶颈问题，亟需新理论和新方法予以突破。申请人发现该问题本质上可以归为一类具有复杂动态特性、多约束的多变量优化控制问题，本项目针对该问题，首先，通过研究汽液相变传质传热机理，利用机理和数据相结合的方法，建立汽车多工况下，面向控制的系统模型库；其次，设计包含性能监测、多工况模型库及优化模块的监督优化层和包含工况辨识、控制结构选择及预测控制器模块的过程控制层组成的双层预测控制全局性解决方案；最后，进行运行监测、模型验证和控制性能实验研究。以期将先进控制理论和方法拓展到能源循环利用领域中，解决废热制冷中的相关控制问题。本项目符合国家节能环保重大需求，对促进废热制冷技术发展具有重要的理论和应用价值。

汽车废热喷射式制冷技术为汽车废热能源循环利用开辟了一条新途径，但该系统难以在多工况下稳定高效运行，成为制约其发展的瓶颈问题。本项目从多变量、多约束的复杂动态系统角度，运用计算流体力学、热力学、预测控制等多学科基础理论和方法，通过对系统深入的理论和实验研究，取得了如下研究成果：（1）提出了高效喷射器喷嘴优化设计方法；（2）设计了变工况自调节废热驱动喷射器；（3）获得了废热制冷系统喷射器结构参数灵敏度；（4）建立了废热制冷系统喷射器全工况热力学模型；（5）提出了基于预测控制的喷射式制冷系统控制策略；（6）研制出了废热制冷系统原型机，实现了3KW的制冷量，满足乘用车制冷需求。该研究为推动车船发动机废热制冷技术的发展奠定了理论基础，以及进行了应用技术储备。在项目开展期间，发表SCI论文共8篇，会议论文共7篇，申请发明专利3项，培养硕士研究生7名，博士研究生3名。