船舶废热驱动的船用喷射制冷-转轮除湿空调的研究

Strengthening the recovery of ship waste heat is an important way to promote the energy saving and emission control for ships. In this project, the ejector refrigeration is proposed to be properly combined with the rotary desiccant cooling technology from the point of adapting to the features of application on ships including ship rolling intensely, large percentage of humidification load, large amount of waste heat and availability of ample cooling water source aboard, and therefore to develop a novel marine ejector refrigeration-rotary desiccant air conditioning (A/C) system. The newly-developed A/C system is driven totally by the ship waste heat and can handle the heat and humidification loads independently, and therefore has great advantages and potentials for its application on ships. Using the three-dimension CFD simulation methodology for ejector, a system thermodynamic model for the marine ejector refrigeration-rotary desiccant air conditioning system is developed in this project. The model is validated experimentally using a test rig specifically built for the system. The simulation and experimental study of the impacts from system’s operating parameters, structural parameters and construction scheme on the system’s performance is carried out and their influence rules are investigated. The coupling characteristics among system parameters are analyzed, and the matching property between the ejector refrigeration and the rotary desiccant cooling is studied. The system’s operation mechanism is therefore discovered. Using the method of advanced exergy analysis, the irreversibility of the marine ejector refrigeration-rotary desiccant A/C system is comprehensively studied in order to improve the effective cascaded utilization of ship waste heat and then to increase the system’s energy utilization efficiency. The research of this project will provide theoretical foundation for the application and development of the marine ejector refrigeration-rotary desiccant A/C system, and promote the recovery of ship waste heat, and therefore has important scientific significance.

加强废热回收利用是船舶节能减排的重要措施。本项目根据船舶应用的特点如船舶摇晃剧烈、湿负荷大、废热丰富和冷却水源充足，提出将喷射制冷与转轮除湿空调有机结合，构建一种新型的船用喷射制冷-转轮除湿空调；该空调可完全由船舶废热驱动，能实现热湿独立处理，在船舶上具有良好的应用优势和潜力。本项目结合利用喷射器的三维CFD部件仿真，建立船用喷射制冷-转轮除湿空调的热力学系统模型，并搭建实验台进行验证；通过仿真和实验研究，考察系统的运行参数、结构参数以及构建形式对系统运行性能的影响规律，分析系统参数间的耦合特性以及喷射制冷与转轮除湿空调之间的匹配特性，揭示系统的运行机理；运用高等 火用分析方法，探究船用喷射制冷-转轮除湿空调的不可逆损失特性，加强船舶废热的有效梯级利用，提升系统能量利用效率。本项目的研究将为船用喷射制冷-转轮除湿空调的应用和发展提供理论依据，推动船舶废热的回收利用，具有一定的科学意义。

加强船舶废热的回收利用是实现船舶节能减排的重要措施之一，在船舶上引入由废热驱动的新型空调技术可有效实现船舶空调节能。本项目构建起一种新型的、可完全由船舶废热驱动的船用喷射制冷-转轮除湿空调系统，系统由喷射制冷子系统和转轮除湿空调子系统构成。对船用喷射制冷-转轮除湿空调系统不同的流程型式及其特点进行考察和节能分析，指出采用两级转轮除湿的系统可适应船舶空调高温高湿的工作环境，在全运行工况下均可实现显著的节能和良好的温湿度控制。通过结合某实船空调设计参数对船用喷射制冷-转轮除湿空调系统的性能参数进行对比分析，提出当系统采用由船舶废热所产生的水蒸汽作为热源时，喷射制冷子系统则无需选用过高的引射系数，引射系数应设定为0.2～0.3。分析筛选喷射制冷子系统的适用工质，并对除湿转轮的除湿剂的性能进行测试和计算，指出系统可优先选用水作为工质和硅胶作为除湿剂。搭建起性能先进的船用喷射制冷-转轮除湿空调系统实验台/样机。.提出一种对喷射制冷子系统中喷射器进行评价的新方法，通过构建虚拟喷嘴以获取理想基准，以及设立两个指标即相对压力比RPR和相对面积比RAR来衡量喷射器偏离理想状态的程度，可为喷射制冷子系统的设计和优化提供明确的方向指导。通过引入D-A方程预测除湿剂的吸附行为，利用经典密度泛函理论求解水分子在硅胶圆柱孔的吸附行为，建立起描述除湿转轮工作过程的数学模型；基于除湿转轮、喷射器、换热器等各主要部件的部件模型，建立起船用喷射制冷-转轮除湿空调系统的热力学仿真模型。分析考察船用喷射制冷-转轮除湿空调系统的性能参数随工况条件的变动关系以及各运行参数间的影响规律，掌握了系统的动态特性；利用高等㶲分析法对船用喷射制冷-转轮除湿空调系统进行分析，指出系统主要部件的各类㶲损失和优化顺序。本项目的研究可为后续船用喷射制冷-转轮除湿空调系统的控制和优化的研究以及实船应用提供技术依据和理论基础。