直膨式多空间降温除湿的双重耦合作用机理研究

With the increase in living standards, air conditioning has been extensively applied to buildings to provide occupants with a thermally comfortable environment. Consequently, energy use for air conditioning has significantly increased over the last few decades. It is therefore very important to develop energy conscious air conditioning technology to achieve energy saving and contribute to sustainability. Direct Expansion Multi-evaporator air conditioning (MEAC) may be regarded as one of the energy conscious air conditioning technologies. However, most MEAC systems currently focus on temperature control only, leaving indoor humidity level uncontrolled, so that the potential of MEAC technology in achieving energy saving has not yet been fully explored. Therefore in this proposed project, based on previous extensive related research by the investigator on modeling and controlling both single evaporator air conditioning systems and MEAC systems, a dynamic MEAC system model, which combines the simulation of system operating characteristics, heat and mass transfer of air side and sensible and latent cooling load balance of conditioned spaces, will be firstly developed. Using the dynamic model and a MEAC system experimental station expected to be built up, the double-coupling mechanism of cooling and dehumidification of a MEAC system will be investigated by simulation and experiments. Based on the understanding of the coupling characteristics, a novel-partial decoupling algorithm will be developed for simultaneously controlling temperature and humidity of conditioned spaces served by the MEAC system. The successful carrying out of the proposed project will help achieve better thermal comfort for occupants, improved indoor air quality (IAQ) and reduced energy use, through improved indoor air humidity. The long-term significance is the contribution to a) sustainability by reducing air conditioning energy use while improving the thermal comfort of occupants, and b) to the advance of MEAC technology. While the project outcomes are expected to be globally applicable, they will be particularly useful in subtropical area, such as the south-east of China, where dehumidification using AC systems has always been a challenge.

直膨式中央空调系统兼具冷水式中央空调系统与直膨式一拖一空调系统的优点。然而直膨式多空间降温除湿包含双重耦合，其在理论研究与技术实施上的困难导致传统研究忽略除湿过程，仅以温度控制为目标。由此引致的室内舒适度降低以及潜在的能耗提高难以匹配人们对于室内热舒适要求的日益提升以及对建筑能耗越来越严格的限制。本项目突破了传统的"直膨式中央空调温湿度控制所需输入控制变量不足"思路的束缚，从室内湿度舒适范围并不局限于某一点着手，创新性得提出了部分解耦法，既保证室内温度控制，又强化对室内湿度的控制。从空调系统动态特性，多空间冷量分布耦合机理，传热传质理论出发，本项目着重研究直膨式中央空调的双重耦合作用机理，从理论和实验两方面揭示在内部耦合影响下的空气侧热湿耦合特性，寻求双重耦合数据平面，以此建立部分解耦法的具体调控机制以及实用过程中的优化规律。本项目也可为类似的非线性、双重耦合过程的作用机理研究提供参考。

本研究项目着重研究存在于直膨式中央空调（多联机系统）的双重耦合作用机理，即由单一蒸发器内部的热湿耦合以及多个蒸发器之间的相互耦合所构成的复杂耦合现象，并通过对双重耦合作用机理的分析，建立适用于直膨式空调系统（包括多联机系统）的面向控制的建模方法以及开发相应的新型控制算法，不仅保证室内温度的控制效果，更能改善室内湿度的控制效果。.在三年的研究过程中，项目组提出了面向温湿度软解偶控制的直膨式空调系统新型混合建模方法，在精确模拟空调系统内传热现象的基础上，进一步精确模拟传质现象，并借由人工智能神经网络来大大降低系统模型的运算代价。在单机模型的基础上，项目组建立了带三个蒸发器的多联机系统模型。另外，项目组搭建了多功能直膨式空调实验系统。利用模型仿真配合实验数据，项目组先是探讨了热湿耦合数据平面在室内温湿度工况改变时发生的变化，提出了全新的数据处理方法，大大降低了建立耦合数据平面的数据量要求。接着项目组进一步探寻了多联机系统内部耦合对热湿耦合数据平面的影响，直观地揭示了多空间降温除湿所特有的双重耦合作用。在以上研究的基础上，项目组开发了多种先进的直膨式空调控制算法，建立了对单机系统的热湿耦合进行完全解耦的温湿度软解耦控制，以及对多联机系统的热湿耦合达到部分解耦但是对其室内机之间的内部耦合进行完全解耦的方法（简称部分解耦法），并通过实验验证了了控制效果。.本项目共发表SCI论文5篇，EI论文1篇（已收录，处于杂志排版发表阶段），中文核心论文2篇（其中1篇处于录用未发表状态），国际会议论文1篇，国内会议大会特邀报告2篇，参会论文1篇，授权发明专利1项，还有2项发明专利处于实质审查阶段，2项发明专利通过初步审查。超额完成了成果指标。并且相关工作成果仍在持续整理、产出中。.